Outcomes After Arthroscopic Treatment of Femoroacetabular Impingement for Patients With Borderline Hip Dysplasia

Patient-related risk factors associated with less favourable outcomes following hip arthroscopy

AIMS

This paper aims to review the evidence for patient-related factors associated with less favourable outcomes following hip arthroscopy.

METHODS

Literature reporting on preoperative patient-related risk factors and outcomes following hip arthroscopy were systematically identified from a computer-assisted literature search of Pubmed (Medline), Embase, and Cochrane Library using Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines and a scoping review.

RESULTS

Assessment of these texts yielded 101 final articles involving 90,315 hips for qualitative analysis. The most frequently reported risk factor related to a less favourable outcome after hip arthroscopy was older age and preoperative osteoarthritis of the hip. This was followed by female sex and patients who have low preoperative clinical scores, severe hip dysplasia, altered hip morphology (excess acetabular retroversion or excess femoral anteversion or retroversion), or a large cam deformity. Patients receiving workers' compensation or with rheumatoid arthritis were also more likely to have a less favourable outcome after hip arthroscopy. There is evidence that obesity, smoking, drinking alcohol, and a history of mental illness may be associated with marginally less favourable outcomes after hip arthroscopy. Athletes (except for ice hockey players) enjoy a more rapid recovery after hip arthroscopy than non-athletes. Finally, patients who have a favourable response to local anaesthetic are more likely to have a favourable outcome after hip arthroscopy.

CONCLUSION

Certain patient-related risk factors are associated with less favourable outcomes following hip arthroscopy. Understanding these risk factors will allow the appropriate surgical indications for hip arthroscopy to be further refined and help patients to comprehend their individual risk profile. Cite this article: Bone Joint J 2020;102-B(7):822-831.

Approach to the Patient With Failed Hip Arthroscopy for Labral Tears and Femoroacetabular Impingement

There has been an exponential increase in the diagnosis and treatment of patients with femoroacetabular impingement, leading to a rise in the number of hip arthroscopies done annually. Despite reliable pain relief and functional improvements after hip arthroscopy in properly indicated patients, and due to these increased numbers, there is a growing number of patients who have persistent pain after surgery. The etiology of these continued symptoms is multifactorial, and clinicians must have a fundamental understanding of these causes to properly diagnose and manage these patients. Factors contributing to failure after surgery include those related to the patient, the surgeon, and the postoperative physical therapy. This review highlights common causes of failure, including those related to residual bony deformity as well as capsular deficiency, and provides a framework for diagnosis and treatment of these patients.

A Contemporary Look at the Evaluation and Treatment of Adult Borderline and Frank Hip Dysplasia

BACKGROUND

Adult hip dysplasia is often diagnosed according to the lateral center-edge angle (LCEA). Patients with frank hip dysplasia (LCEA <20°) traditionally require treatment with bony realignment through a periacetabular osteotomy (PAO) and/or derotational femoral osteotomy, while patients with borderline hip dysplasia (BHD) present a challenging treatment dilemma, as it remains unknown when they should be treated with hip arthroscopy and/or a PAO.

PURPOSE

To perform a narrative review to report the differences in hip morphology and clinical outcomes between adult patients with frank hip dysplasia and BHD.

STUDY DESIGN

Narrative review.

METHODS

A systematic search of the literature was conducted through the Medline, EMBASE, and Cochrane databases with the search phrase borderline hip dysplasia.

RESULTS

The search identified 305 articles, of which 48 were considered relevant to this study after screening of titles and abstracts. Four articles discussed new radiographic means of evaluating adult hip dysplasia, 16 articles analyzed morphology of dysplastic hips, and 28 articles described the clinical outcomes of patients with frank hip dysplasia or BHD treated with hip arthroscopy and/or PAO. Because the level of evidence obtained from this search was not adequate for systematic review or meta-analysis, a current concepts review on the diagnosis, hip morphology, and clinical outcomes of patients with frank hip dysplasia or BHD is presented.

CONCLUSION

Adult hip dysplasia is most commonly diagnosed based on the LCEA; however, the LCEA is an unreliable sole marker for dysplasia, and additional radiographic parameters should be utilized. Furthermore, specific pathology identified on imaging and/or during hip arthroscopy can provide clues to a surgeon when the diagnosis is inconclusive according to history and physical examination alone. While the data support that patients with frank dysplasia are best treated with PAO, there is no such preferred treatment for patients with BHD, who have a wide spectrum of instability. Selective use of arthroscopic labral and capsular treatment alone may provide good results in carefully chosen patients with BHD, while some may end up requiring a bony realignment procedure.

Radiographic and clinical characteristics associated with a positive PART (Prone Apprehension Relocation Test): a new provocative exam to elicit hip instability

Hip instability due to mild dysplasia can be a diagnostic challenge. The physical exam is an important adjunct to radiographic evaluation for the clinical diagnosis of hip instability. Herein, we describe a new maneuver to replicate hip instability pain, called the PART (Prone Apprehension Relocation Test). We retrospectively identified patients in our institution’s hip preservation registry who presented for evaluation of hip pain. We divided patients into ‘positive’ or ‘negative’ PART and analyzed associated clinical and radiographic findings. Ninety patients (159 hips) were included, 83 female and 7 male, average age 27.3 ± 9.1 years. Thirty-four hips (21.4%) had a positive PART. There were no significant differences in hip range of motion, lateral center edge angle, or in acetabular depth. There was, however, a significant difference in acetabular version at 3 o’clock between the two test groups (18.5 ± 6.9° in negative, 21.2 ± 4.9° in positive, P = 0.045). There was no association between PART and previously described anterior apprehension testing. Historical methods of diagnosing hip dysplasia may not adequately identify patients with clinical hip instability. We describe a new provocative exam, the PART, which may be helpful in replicating hip instability symptoms in patients with anterior acetabular undercoverage. PART positive patients had significantly more acetabular anteversion at the 3 o’clock position, which is measured on computed tomography and is not visible on standard anteroposterior (AP) pelvis or false profile radiographs. We believe that the PART is a valuable supplement to clinical examination and radiographic measurements to identify patients with symptomatic hip instability.

Patients With Borderline Hip Dysplasia Achieve Clinically Significant Improvement After Arthroscopic Femoroacetabular Impingement Surgery: A Case-Control Study With a Minimum 5-Year Follow-up

BACKGROUND

Hip arthroscopy for the treatment of femoroacetabular impingement syndrome (FAIS) in patients with borderline hip dysplasia (BHD) is becoming a more common practice. However, the literature on achieving meaningful outcomes at midterm follow-up, as well as predictors of these outcomes, is limited.

PURPOSE

To (1) compare the rates of achieving meaningful clinical outcomes between patients with and without BHD and (2) identify the predictors for achieving clinical success among patients with BHD 5 years after undergoing hip arthroscopic surgery for FAIS.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Data from consecutive patients who underwent primary hip arthroscopic surgery with routine capsular closure for the treatment of FAIS between January 2012 and August 2014 were collected and retrospectively analyzed. Patients with BHD (lateral center-edge angle [LCEA] 20°-25°) were matched 1:2 by age (±1 year) and body mass index (BMI; ±5 kg/m²) to control patients with normal acetabular coverage (LCEA 25°-40°). Data collected included baseline and 5-year postoperative patient-reported outcomes. The minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) were calculated for each patient-reported outcome measure and compared between the 2 groups. A binary logistic regression analysis was used to identify significant predictors of achieving the MCID and PASS in the BHD group.

RESULTS

The MCID in the BHD group was defined as 9.6, 14.1, and 9.5 for the Hip Outcome Score-Activities of Daily Living, Hip Outcome Score-Sports Subscale, and modified Harris Hip Score, respectively. Threshold scores for achieving the PASS in both groups were 90.9, 76.6, and 81.9, respectively. A total of 88 patients were identified with having BHD and were matched to 176 controls. No statistical differences were identified for age, BMI, or sex. Both the BHD and the non-BHD groups had statistically significant increases in patient-reported outcome scores over the 5-year period, but the difference in both groups was not statistically significant (P > .05 for all). There was no statistical difference in the frequency of patients in the BHD and non-BHD groups achieving the MCID (86.6% vs 85.2%, respectively; P = .804) or PASS (76.0% vs 73.7%, respectively; P = .675) on at least 1 outcome measure. The logistic regression model demonstrated that being physically active (odds ratio [OR], 27.59; P = .005) and being female (OR, 14.64; P = .025) were independent predictors of achieving the MCID, while running (OR, 11.1; P = .002), being female (OR, 7.6; P = .011), and a larger preoperative LCEA (OR, 2.3; P = .001) were independent preoperative predictors of achieving the PASS.

CONCLUSION

The rates of achieving clinical success 5 years after undergoing arthroscopic treatment with capsular closure for FAIS were not significantly different between patients with BHD and those with normal acetabular coverage. Being physically active, running for exercise, female sex, and a larger LCEA were preoperative predictors of achieving clinical success at 5 years in patients with BHD.

Is Hip Arthroscopy an Adequate Therapy for the Borderline Dysplastic Hip? Correlation Between Radiologic Findings and Clinical Outcomes

Background

Recent studies have shown that assessment of the lateral center-edge angle (LCEA) between 18° and 25° is not sufficient to adequately classify mildly dysplastic hips and that further radiological features should be considered. However, no correlation between different morphologic features and clinical outcomes has been investigated so far.

Purpose

To analyze the clinical outcomes of patients with different subtypes of borderline dysplastic hips who underwent arthroscopic surgery.

Study Design

Cohort study; Level of evidence, 3.

Methods

We examined patients with an LCEA between 18° and 25° who underwent arthroscopic treatment for femoroacetabular impingement syndrome between January 2015 and December 2016. A hierarchical cluster analysis was performed to identify hip morphologic subtypes according to radiographic parameters, including the LCEA, femoro-epiphyseal acetabular roof (FEAR) index, anterior and posterior wall indices (AWI and PWI), Tönnis angle, alpha angle, and femoral neck-shaft angle. In addition, the International Hip Outcome Tool 12 (iHOT-12) and a visual analog scale (VAS) for pain were applied preoperatively and at follow-up, and the results were compared among the different clusters. Previously reported minimal clinically important difference (MCID) and patient acceptable symptomatic state (PASS) values were used to determine clinically significant improvements.

Results

A total of 40 patients were identified. Of these, 36 patients were available for evaluation at a mean follow-up of 43.8 months. In total, 4 sex-independent clusters with different morphologic patterns of the hip were identified: cluster 1, unstable anterolateral deficiency (FEAR index >2°, AWI <0.35); cluster 2, stable anterolateral deficiency (FEAR index <2°, AWI <0.35); cluster 3, stable lateral deficiency (FEAR index >2°, normal AWI and PWI); and cluster 4, stable posterolateral deficiency (FEAR index <2°, PWI <0.85). At follow-up, clusters 1, 2, and 3 showed significantly improved iHOT-12 (P < .0001) and VAS pain (P < .0001) scores, and cluster 4 showed no significant improvements. The MCID of 15.2 points was achieved by all patients in clusters 2 and 3, by 63% of patients in cluster 1, and by 23% of patients in cluster 4. Clusters 2 and 3 differed significantly from clusters 1 and 4 (P = .02). A postoperative PASS score of 60 was achieved by all patients in cluster 3, by 86% of patients in cluster 2, by 63% of patients in cluster 1, and by 20% of patients in cluster 4. The differences between the groups were statistically significant (P = .01).

Conclusion

Arthroscopic surgery yielded good results in the treatment of stable borderline hip dysplasia with anterolateral and lateral deficiency. In contrast, borderline hip dysplasia with acetabular retroversion showed no improvements after arthroscopic therapy. This study underlines the need for an accurate analysis of all possible radiological signs to adequately classify borderline dysplastic hips.

Routine Interportal Capsular Repair Does Not Lead to Superior Clinical Outcome Following Arthroscopic Femoroacetabular Impingement Correction With Labral Repair

PURPOSE

To evaluate the impact of routine capsular repair on clinical outcome in a consecutive series of patients undergoing arthroscopic correction of symptomatic femoroacetabular impingement.

METHODS

Between 2009 and 2015, patients were assigned to 1 of 2 groups based on whether a capsular repair was performed as part of their index hip arthroscopic procedure. Exclusion criteria included previous underlying hip conditions, Tönnis >1, age >45 years, and labrum not repaired. Patients were assessed preoperatively and 2-years postoperatively using patient-reported outcome measures (PROMs), including the modified Harris hip score (mHHS), UCLA activity scale, short form-36, Western Ontario and McMaster Universities Osteoarthritis Index score, and measures of range of hip movements. The incidence of any subsequent revision surgery within 2 years was recorded. Sex and age groups were specifically analyzed.

RESULTS

In total, 966 consecutive cases were included (96.4% follow-up rate): 508 in group A (no repair) and 458 in group B (repair). Average age for all cases was 28.1 ± 7.0 years (14.6-44.9). There were significant improvements in all PROMs following surgery for both groups (P < .001). Statistical significance between groups at 2 years was observed for Short Form-36 (P = .001) and WOMAC (P = .041), greater in group A. Both groups similarly met the minimal clinically important difference (mHHS P = .414 and .605; UCLA, P = .549 and .614; Short Form-36, P = .455 and .079; WOMAC, P = .425 and .750 for distribution and anchor-based methods, respectively). In total, 38 (7.8%) cases group A and 24 (5.4%) cases group B required repeat hip arthroscopy (HA) (P = .148); No (0%) cases in group A and 2 (0.45%) cases in group B required total hip replacement (P = .226). There was significantly lower rate of repeat HA among 25- to 34-year age group (8.6% vs 3.9%, P = .047) where capsular repair was performed. No significant difference in the rate of repeat HA between groups for male (P = .203) or female (P = .603) subjects. Adhesions were more common in the repair group (79.2%, 95% confidence interval [CI] 57.8-92.9 vs 55.3%, CI 38.3-71.4; P = .055), with further capsular repair/plication required more frequently in the unrepaired group (50%, CI 33.4-66.6 vs 25%, CI 10.8-44.3); however, differences between groups were not significant (P = .051). Internal rotation was larger in group A compared with group B at 2 years (36.2 vs 28.1, P = .000). Female patients with capsular repair had reduced PROM scores at 2 years compared with female patients without repair (WOMAC, P = .004, and mHHS, P = .037).

CONCLUSIONS

Arthroscopic correction of femoroacetabular impingement with labral repair results in significant improvements in patient-reported outcomes at 2-years postsurgery, irrespective of whether the capsule is repaired. Routine capsular repair in a consecutive series of patients did not lead to superior outcomes compared with a nonrepaired group; similar proportions of cases in both groups were able to achieve minimal clinically important difference. In female patients, routinely repairing the capsule may lead to statistically inferior clinical outcome at 2-years postsurgery, although this may not be clinically significant. Routine capsular repair, however, may be beneficial in the younger, active patient, where a significant reduction in repeat arthroscopy was observed.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Clinical and radiographic predictors of failed hip arthroscopy in the management of dysplasia: a systematic review and proposal for classification

PURPOSE

As indications for hip arthroscopy continue to expand, its efficacy in patients with more complex deformities of the hip, such as those with acetabular dysplasia, remains controversial. The purpose of this systematic review is to identify the predictors of failed hip arthroscopy in dysplastic hips and to propose a standardize prognostic sub-classification of dysplasia.

METHODS

This systematic review was performed in accordance with the (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) PRISMA guidelines. Three databases [EMBASE, PubMed, and Ovid (MEDLINE)] were searched using terms including "hip arthroscopy" and "dysplasia". Studies were screened and data extracted in duplicate. Study quality was assessed using the Methodological Index for Non-Randomized Studies criteria. Due to the non-uniform nature of study data, findings were presented in descriptive summary form.

RESULTS

Thirteen studies were included in this systematic review, comprising 712 dysplastic patients (773 hips) with mean age 34.2 years and 74.1% females. Most studies defined hip dysplasia by a lateral centre-edge angle (LCEA) of 20°-25° (borderline) or 15°-20° (moderate). Failure was defined as progression to revision arthroscopy, peri-acetabular osteotomy, or total hip arthroplasty. Overall, failure rate was 192/743 (25.8%) at an average of 28.1 months following index arthroscopy. Smaller LCEA, larger Tönnis angle, broken Shenton line, and decreased joint space (≤ 2 mm) were radiographic predictors of failure. Severe cartilage lesions to the femoral head or acetabulum were associated with failure in five studies. Labral debridement led to more failures than labral repair.

CONCLUSION

Overall, hip arthroscopy yielded good outcomes in mildly dysplastic hips without severe chondral damage. Hip arthroscopy is expected to result in a failed outcome in individuals with moderate-to-severe hip dysplasia (LCEA < 15°), severe cartilage lesions, larger Tönnis angle (> 20°), broken Shenton line, and decreased joint space (≤ 2 mm). Arthroscopic surgery may be more effective in individuals with borderline-to-mild (LCEA 15°-25°) acetabular dysplasia in the absence of severe cartilaginous lesions (7-year survival: 89.6%). A standardized prognostic classification of hip dysplasia based on the LCEA and Tönnis angle is proposed.

LEVEL OF EVIDENCE

Systematic review of non-randomized studies, Level IV.

Editorial Commentary: At the Intersection of Borderline Dysplasia and Femoroacetabular Impingement-Which Way Should We Turn?

Borderline acetabular dysplasia remains a controversial topic in hip preservation, with poor current comparative literature to guide accurate diagnosis and treatment decision making. Borderline dysplasia represents a "transitional acetabular coverage" pattern between more classic acetabular dysplasia and normal coverage. Traditionally, borderline dysplasia has been defined by a lateral center-edge angle between 20° and 25°, whereas more recently, some authors have used 18° to 25°. Treatment decisions between isolated hip arthroscopy (addressing labral tears, femoroacetabular impingement morphology, and capsular laxity) and periacetabular osteotomy (improving joint stability, often combined with arthroscopy) remain challenging because the fundamental mechanical diagnosis (instability vs femoroacetabular impingement) can be difficult to determine clinically. Obtaining an accurate diagnosis to direct surgical treatment relies on comprehensive assessment of additional bony anatomy features (including femoral version) and patient characteristics (including sex, soft-tissue laxity, and range of motion). Future research efforts in borderline dysplasia should better characterize the role of disease- and patient-specific factors that will inform accurate diagnoses, leading to the development of optimal treatment strategies in distinct patient subgroups through comparison of treatment outcomes.

Surgical Outcomes in the Treatment of Concomitant Mild Acetabular Dysplasia and Femoroacetabular Impingement: A Systematic Review

PURPOSE

To analyze the current approaches and clinical outcomes in the surgical management of concomitant mild acetabular dysplasia and femoroacetabular impingement (FAI).

METHODS

Following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) method, the PubMed and Medline databases were searched in March 2019 for studies that reported on surgical outcomes in hips with concomitant mid acetabular dysplasia and FAI. Studies published in English that focused on the surgical outcomes after hip arthroscopy, open surgery, or periacetabular osteotomy of concomitant acetabular dysplasia and FAI, in which the lateral center-edge angle of all subjects was between 15° and 25°, were included. Articles that included subjects with lateral center-edge angle <15°, with a minimum follow-up duration <1 year, had <5 subjects, or were not original articles were excluded.

RESULTS

The initial search yielded 748 studies, and 5 studies met the inclusion criteria. All these 5 studies focused on hip arthroscopic treatment for patients with concomitant mild acetabular dysplasia and FAI. Three studies had level III evidence, whereas 2 studies had level IV evidence. The mean patient age range across the studies was 29.8 to 49.6 years, and the female-to-male ratio was 1.14. Improved patient-reported outcomes (Hip Outcome Score-Activities of Daily Living, Hip Outcome Score-Sport, modified Harris Hip Score, Short Form-12 Physical Component Summary, Western Ontario and McMaster Universities Osteoarthritis Index) at a minimum 2-year follow-up were obtained in 4 of the 5 studies. Two of these 4 studies had a comparative cohort of patients with FAI with normal acetabular coverage, and there was no significant difference in the postoperative outcomes and secondary procedure rate between patients with mild acetabular dysplasia and those with normal acetabular coverage.

CONCLUSIONS

This systematic review indicates that improved patient-reported outcomes can be obtained with hip arthroscopy in the treatment of concomitant mild acetabular dysplasia and FAI at a minimum 2-year follow-up.

LEVEL OF EVIDENCE

Level IV, systematic review of Level III and Level IV studies.

Evaluation and Treatment of Borderline Dysplasia: Moving Beyond the Lateral Center Edge Angle

PURPOSE OF REVIEW

The purpose of this manuscript is to 1 define the features associated with borderline acetabular dysplasia and 2 review current status of diagnostic algorithms and treatment options for borderline dysplasia.

RECENT FINDINGS

Acetabular dysplasia is a common cause of hip pain secondary to insufficient coverage of the femoral head by the bony acetabulum. Historical classification of acetabular dysplasia has utilized the lateral center edge angle (LCEA); values above 25° are normal and below 20° are considered pathologic. Borderline dysplasia describes hips with LCEA between 20 and 25^o; treatment of these patients is controversial. While many studies utilize LCEA in classification of borderline dysplasia, isolated reliance on measurement of lateral femoral head coverage to define severity of undercoverage will continue to mislabel morphology. Thorough assessment of the characteristics of mild acetabular undercoverage is necessary for future studies, which will allow effective comparisons of results between hip arthroscopy and periacetabular osteotomy.

Physical Activity Following Hip Arthroscopy in Young and Middle-Aged Adults: A Systematic Review

Background

Hip arthroscopy is a common surgical intervention for young and middle-aged adults with hip-related pain and dysfunction, who have high expectations for returning to physical activity following surgery. The purpose of this review was to evaluate the impact of hip arthroscopy on physical activity post-arthroscopy.

Methods

A systematic search of electronic databases was undertaken in identifying studies from January 1st 1990 to December 5th 2019. The search included English language articles reporting physical activity as an outcome following hip arthroscopy in adults aged 18-50 years. Quality assessment, data extraction and synthesis of included studies were undertaken.

Results

Full text articles (n = 234) were assessed for eligibility following screening of titles and abstracts (n = 2086), yielding 120 studies for inclusion. The majority (86%) of the studies were level 4 evidence. One study reported objective activity data. The most frequently occurring patient-reported outcome measure was the Hip Outcome Score-sport-specific subscale (HOS-SS, 84% of studies). Post--arthroscopy improvement was indicated by large effect sizes for patient-reported outcome measures (standard paired difference [95% confidence interval] −1.35[−1.61 to −1.09] at more than 2 years post-arthroscopy); however, the majority of outcome scores for the HOS-SS did not meet the defined level for a patient-acceptable symptom state.

Conclusion

The current level of available information regarding physical activity for post arthroscopy patients is limited in scope. Outcomes have focused on patients’ perceived difficulties with sport-related activities with a paucity of information on the type, quality and quantity of activity undertaken.

Level of Evidence

Level IV, systematic review of Level 2 through to Level 4 studies

Patients aged in their 70s do not have a high risk of progressive osteoarthritis following arthroscopic femoroacetabular impingement correction and labral preservation surgery

PURPOSE

The purposes of this study were to (1) evaluate the effect of age on clinical outcomes of arthroscopic femoroacetabular impingement (FAI) with labral preservation surgery and (2) identify predictors of poor postoperative clinical outcomes.

METHODS

Eighty-four patients who underwent hip arthroscopic treatment for FAI between 2009 and 2013 were retrospectively reviewed. Patients were divided into three groups based on age. The Advanced age group consisted of patients over 70 years old, the Middle age group consisted of patients in their 50s and 60s, and the Younger age group consisted of patients less than 50 years of age. Total hip arthroplasty (THA) conversion, radiographic progression of osteoarthritis and patient-reported outcomes including modified Harris Hip Score (MHHS) and Non-arthritic Hip Score (NAHS) were investigated.

RESULTS

The mean follow-up period was 32.2 (range 24-60) months. THA was required in 3 patients in their 50s and 60s, which was a significantly higher rate compared to that in patients Younger than 50 years old (17% vs 0%, p = 0.036). Progression to osteoarthritis was also significantly more frequent in patients in their 50s and 60s than in patients in their 70s (50s and 60s: 33%; 70s: 0%, p = 0.030). In all age groups, the preoperative MHHS and NAHS improved at last follow-up (p < 0.001). The 50s and 60s age group [hazard ratio (HR) 6.62], preoperative mild osteoarthritic change (Tönnis grade 1, HR: 3.29) and severe cartilage damage on the acetabulum (HR: 2.63) were risk factors for progressive osteoarthritis and THA conversion.

CONCLUSIONS

Arthroscopic FAI correction and labral preservation surgery provide favourable clinical outcomes for patients over 70 years old in the absence of significant osteoarthritis and severe acetabular chondral damage. Patients in their 50s and 60s have a higher risk of both THA conversion and progressive osteoarthritis, while patients aged over 70 years show no evidence of progressive osteoarthritis. Chronologic age in isolation is not an absolute contra-indication to hip arthroscopy.

LEVEL OF EVIDENCE

III.

Acetabular Morphologic Characteristics Predict Early Conversion to Arthroplasty After Isolated Hip Arthroscopy for Femoroacetabular Impingement

BACKGROUND

Hip arthroscopy in the setting of dysplasia and borderline dysplasia is controversial. Dysplasia severity is most often defined by the lateral center edge angle (LCEA) but can also be evaluated radiographically by the acetabular inclination (AI).

PURPOSE/HYPOTHESIS

The purpose was to determine the effect of AI on outcomes after isolated hip arthroscopy for femoroacetabular impingement (FAI). We hypothesized that patients with dysplasia would have higher rates of arthroplasty as well as inferior clinical and functional outcomes compared with patients who did not have dysplasia.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A hip arthroscopy registry was reviewed for participants undergoing arthroscopic correction of FAI from February 28, 2008, to June 10, 2013. Participants required a clinical diagnosis and isolated arthroscopic correction of FAI with preoperative imaging and intraoperative cartilage status recorded. AI dysplasia was defined as an AI greater than 10°, LCEA dysplasia as LCEA less than 18°, and borderline LCEA dysplasia as LCEA 18° to 25°. Patients without an acetabular deformity (LCEA 25°-40°; AI <10°) served as a control population. Postoperative variables included patient-reported outcome surveys with conversion to arthroplasty as the primary endpoint. Minimum 5-year outcome scores were obtained for 337 of 419 patients (80.4%) with an average follow-up of 75.2 ± 12.7 months.

RESULTS

This study included 419 patients: 9 (2%) with LCEA dysplasia, 42 (10%) with AI dysplasia, and 51 (12%) with borderline dysplasia. The AI but not LCEA was significantly correlated with lower outcome scores on the modified Harris Hip Score (r = 0.13; P = .01), Non-Arthritic Hip Score (r = 0.10; P = .04), and Hip Outcome Score-Sports Subscale (r = 0.11; P = .04). A total of 58 patients (14%) underwent arthroplasty at 31 ± 20 months postoperatively. Patients with LCEA dysplasia had an arthroplasty rate of 56% (odds ratio, 8.4), whereas patients with AI dysplasia had an arthroplasty rate of 31% (odds ratio, 3.3), which was significantly greater than the rate for the nondysplastic cohort (13.5%; P < .0001). Patients with borderline LCEA dysplasia did not have increased rates of arthroplasty. A multivariate analysis found increasing age, increasing AI, Tönnis grade higher than 1, and femoral Outerbridge grade higher than 2 to be most predictive of conversion to arthroplasty.

CONCLUSION

We found that an elevated AI, along with increasing age, Tönnis grade, and femoral Outerbridge grade significantly predict early conversion to arthroplasty after isolated hip arthroscopy. We recommend using the AI, in addition to the LCEA, in evaluating hip dysplasia before hip arthroscopy.

Is the Femoro-Epiphyseal Acetabular Roof (FEAR) index on MRI a relevant predictive factor of instability in a borderline dysplastic hip?

AIMS

A borderline dysplastic hip can behave as either stable or unstable and this makes surgical decision making challenging. While an unstable hip may be best treated by acetabular reorientation, stable hips can be treated arthroscopically. Several imaging parameters can help to identify the appropriate treatment, including the Femoro-Epiphyseal Acetabular Roof (FEAR) index, measured on plain radiographs. The aim of this study was to assess the reliability and the sensitivity of FEAR index on MRI compared with its radiological measurement.

PATIENTS AND METHODS

The technique of measuring the FEAR index on MRI was defined and its reliability validated. A retrospective study assessed three groups of 20 patients: an unstable group of 'borderline dysplastic hips' with lateral centre edge angle (LCEA) less than 25° treated successfully by periacetabular osteotomy; a stable group of 'borderline dysplastic hips' with LCEA less than 25° treated successfully by impingement surgery; and an asymptomatic control group with LCEA between 25° and 35°. The following measurements were performed on both standardized radiographs and on MRI: LCEA, acetabular index, femoral anteversion, and FEAR index.

RESULTS

The FEAR index showed excellent intraobserver and interobserver reliability on both MRI and radiographs. The FEAR index was more reliable on radiographs than on MRI. The FEAR index on MRI was lower in the stable borderline group (mean -4.2° (sd 9.1°)) compared with the unstable borderline group (mean 7.9° (sd 6.8°)). With a FEAR index cut-off value of 2°, 90% of patients were correctly identified as stable or unstable using the radiological FEAR index, compared with 82.5% using the FEAR index on MRI. The FEAR index was a better predictor of instability on plain radiographs than on MRI.

CONCLUSION

The FEAR index measured on MRI is less reliable and less sensitive than the FEAR index measured on radiographs. The cut-off value of 2° for radiological FEAR index predicted hip stability with 90% probability. Cite this article: Bone Joint J 2019;101-B:1578-1584.

Patients With Borderline Hip Dysplasia Achieve Clinically Significant Outcome After Arthroscopic Femoroacetabular Impingement Surgery: A Case-Control Study With Minimum 2-Year Follow-up

BACKGROUND

There is a growing trend for hip arthroscopists to treat patients with borderline hip dysplasia (BHD) for femoroacetabular impingement syndrome (FAIS) without addressing the acetabular coverage. However, the literature of outcomes and failure rates for these patients is conflicting.

PURPOSE

(1) To identify whether patients with BHD achieved 2-year similar patient-reported outcome, minimal clinically important difference (MCID), and patient acceptable symptomatic state (PASS) when compared with patients without BHD and (2) to identify predictors for achieving the MCID and PASS among patients with BHD who are undergoing hip arthroscopy for FAIS.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Data from consecutive patients who underwent primary hip arthroscopy with routine capsular closure for the treatment of FAIS between January 2012 and January 2017 were collected and retrospectively analyzed. Patients with BHD (lateral center-edge angle [LCEA], 20°-25°) were matched 2:1 by age, sex, and body mass index (BMI) to control patients with normal acetabular coverage (LCEA, >25°-40°). Patient-reported outcome, MCID, and PASS were compared between the groups. Multivariate logistic regression analysis identified significant predictors of achieving the MCID and PASS in the BHD group.

RESULTS

The MCID in the BHD group was defined as 9.2, 13.7, 8.5, and 15.2 for the Hip Outcome Score-Activities of Daily Living, Hip Outcome Score-Sport Specific, modified Harris Hip Score, and iHOT-12, respectively. Threshold scores for achieving the PASS in both groups were 87.9, 76.4, 78.1, and 60.0. A total of 112 patients were identified as having BHD (LCEA, 20°-25°) and were matched to 224 controls. Both groups saw statistically significant increases in score averages over the 2-year period; however, the differences between them were not statistically significant (P > .05 for all). There was no statistical difference in the frequency of the BHD and non-BHD cohorts achieving the MCID on at least 1 threshold score (86.6% vs 85.6%, P = .837) and the PASS (78.6% vs 79.8%, P = .79). There was, however, a statistically significant difference between the rates of patients with and without BHD achieving the PASS on the modified Harris Hip Score threshold (62.5% vs 74.5%, P = .028). The final logistic models demonstrated that lower BMI (odds ratio [OR], 0.872; P = .029), lower preoperative alpha angle (OR, 0.965; P = .014), and female sex (OR, 3.647; P = .03) are independent preoperative predictors of achieving the MCID, while lower preoperative alpha angle (OR, 0.943; P = .018) and self-reported limp (OR, 18.53; P = .007) are independent preoperative predictors of achieving the PASS.

CONCLUSION

Outcome improvements in patients with BHD who are undergoing arthroscopic treatment with capsular closure for FAIS are not significantly different from patients with normal acetabular coverage. Lower BMI, lower alpha angle, absence of limp, and female sex are preoperative predictors of achieving meaningful clinically significant outcome improvements in patients with BHD.

Arthroscopic Outcomes as a Function of Acetabular Coverage From a Large Hip Arthroscopy Study Group

PURPOSE

To report comparative hip arthroscopic outcomes of patients with low (borderline dysplasia), normal, and high (global pincer femoroacetabular impingement [FAI]) lateral acetabular coverage.

METHODS

A retrospective analysis of prospectively collected data from a multicenter registry was performed. Primary hip arthroscopy patients were assigned to 1 of 3 groups based on preoperative lateral center-edge angle: borderline dysplasia (≤25°), normal (25.1°-38.9°), and pincer (≥39°). Repeated-measures analysis of variance compared preoperative with 2-year minimum postoperative International Hip Outcome Tool (iHOT-12) scores. Subsequent analysis of variance determined the effect of acetabular coverage on magnitude of change in scores.

RESULTS

Of 437 patients, the only statistical difference between groups was a lower prevalence of acetabuloplasty in the borderline dysplasia group (P = .001). A significant improvement in the preoperative to postoperative iHOT-12 scores for patients with normal acetabular coverage, acetabular undercoverage, and acetabular overcoverage was observed: F(1, 339) = 311.06; P <.001, with no statistical differences in preoperative (P = .505) and postoperative (P <.488) iHOT-12 scores when comparing the groups based on acetabular coverage. Mean iHOT-12 scores increased from 37.3 preoperatively to 68.7 postoperatively (P <.001) in the borderline dysplasia group, from 34.4 to 72 (P <.001) in the normal coverage group, and from 35.3 to 69.4 (P <.001) in the pincer group. These preoperative scores increased by 31.4, 37.8, and 34.1, respectively, with no effect for acetabular coverage on the magnitude of change from preoperative to postoperative iHOT-12 scores: F(2,339) = 1.18; P = .310. Ten patients (2.3%) underwent conversion arthroplasty, and 19 patients (4.4%) underwent revision arthroscopy with no significant effect of acetabular coverage on the incidence of revision or conversion surgery: χ² (6,433) = 11.535; P = .073.

CONCLUSIONS

Lateral acetabular coverage did not influence outcomes from primary hip arthroscopy when performed in patients with low (borderline dysplasia), normal, and high (global pincer FAI) lateral center-edge angle. Borderline dysplasia and moderate global pincer FAI with no or minimal osteoarthritis do not compromise successful 2-year minimum outcomes or survivorship following primary hip arthroscopy when performed by experienced surgeons.

LEVEL OF EVIDENCE

Level III, retrospective therapeutic trial.

Hip Arthroscopic Surgery in Borderline Developmental Dysplastic Hips: A Systematic Review

BACKGROUND

It remains controversial whether hip arthroscopic surgery should be applied to patients with a borderline developmental dysplastic hip (BDDH).

PURPOSE

To review the outcomes of hip arthroscopic surgery for a BDDH and which factors influence these outcomes.

STUDY DESIGN

Systematic review.

METHODS

PubMed, Embase, and the Cochrane Library were searched through March 2018 for studies reporting the outcomes of primary hip arthroscopic surgery in patients with a BDDH. Inclusion in the review was based on the definition of a BDDH, patient-reported outcomes, and duration of follow-up. The primary outcome was the modified Harris Hip Score (mHHS). The failure rate, visual analog scale, satisfaction score, and patient-reported outcomes such as the Hip disability and Osteoarthritis Outcome Score were defined as secondary outcomes.

RESULTS

Nine studies with 425 patients who underwent hip arthroscopic surgery were included in this review. The mean follow-up times ranged from 25.4 to 28.8 months across the studies. A significant improvement was obtained in the mHHS, with a mean score of 61.8 preoperatively to 82.8 postoperatively; all other patient-reported outcomes also improved significantly, except the 12-Item Short Form Health Survey mental component summary. The overall failure rate was 14.1%, and the mean reoperation rate was 8.5%. The rate of conversion to total hip arthroplasty ranged from 4.4% to 26.0%, and the rate of conversion to periacetabular osteotomy was 4.0%. Combined defects such as cartilage damage, hip osteoarthritis, ligamentum teres tears, and femoroacetabular impingement could influence the outcomes after arthroscopic surgery in BDDHs.

CONCLUSION

Hip arthroscopic surgery was demonstrated to be a promising approach for BDDHs, but the outcomes could be influenced by multiple risk factors. A higher level of evidence is still needed to support current findings.

Health-Related Quality of Life After Hip Arthroscopy for Femoroacetabular Impingement: A Systematic Review and Meta-analysis

CONTEXT

Hip pain from femoroacetabular impingement (FAI) can impair health-related quality of life (HRQL) but can be treated via hip arthroscopy techniques.

OBJECTIVE

To systematically assess the HRQL outcomes after arthroscopic management of FAI.

DATE SOURCES

Three online databases (EMBASE, PubMed, and Ovid [MEDLINE]) were searched for relevant literature from database inception until June 2018 and screened by 2 reviewers independently and in duplicate.

STUDY SELECTION

Level I to IV English studies that investigated HRQL outcomes after hip arthroscopy were included. Data for generic and hip-specific HRQL outcomes were collected. Mean differences were plotted in a forest plot when possible.

STUDY DESIGN

Systematic review.

LEVEL OF EVIDENCE

Level 4.

RESULTS

A total of 29 studies were included for assessment. Of the 6476 patients (6959 hips), the mean age was 32 years (range 9-79 years) and 50.7% were female. Significant improvements were reported in all studies assessing generic HRQL outcomes, including the 12-Item Short Form Health Survey (range of mean postoperative scores, 82.2-89.8), and EuroQOL-5D scores (range of mean postoperative scores, 0.74-0.87) between 12 and 24 months postoperatively. Significant improvements were similarly identified in the hip-specific HRQL outcomes scores, with the majority of studies also reporting improvement between 12 and 24 months postoperatively. Mean improvement in International Hip Outcome Tool-33 scores from preoperative values to postoperative values ranged from 22.7 to 43.2 ( I2 = 44%), for studies with follow-up between 12 and 24 months.

CONCLUSION

Hip arthroscopy can lead to significant improvement in generic and hip-specific HRQL outcomes at 12 to 24 months postoperatively in patients with FAI who do not have advanced hip osteoarthritis. Confirmatory, high-quality, prospective studies are warranted to compare this observed improvement with other treatment modalities for FAI and to determine long-term outcomes.

Feasibility of a new arthroscopic shelf acetabuloplasty technique for hip instability related to moderate dysplasia

Dysplasia-related hip instability causes pain and intra-articular derangement. The bone, the joint capsule, and the labrum are involved. We describe a surgical procedure of limited invasiveness that corrects the dysplasia by creating an acetabular shelf, repairs the secondary lesions by suturing the labrum and tightening the capsule, and corrects cam femoro-acetabular impingement if present.

Hip Dysplasia Compromises the Outcome of Femoroacetabular Impingement Surgery

BACKGROUND

The optimal treatment for patients with symptomatic hip dysplasia presenting with labral tear is unknown. Although femoroacetabular osteoplasty (FAO) has excellent outcome for most femoroacetabular impingement patients, the presence of concomitant hip dysplasia has been implicated as an adverse prognostic factor. This study evaluated the outcome of FAO in a group of dysplastic hips and compared the outcome to a cohort of patients without dysplasia.

METHODS

Seventy-three patients (38 males, 35 females) with hip dysplasia who underwent FAO between 2007 and 2015 were identified. The minimum 2-year clinical, functional (modified Harris Hip Score and Short-Form 36 Health Survey), and radiological outcome was compared with 550 patients without dysplasia who underwent FAO by the same surgeon. The preoperative and postoperative alpha angle, Tonnis grade, joint space, and presence of chondral lesion were determined and compared. Conversion to total hip arthroplasty or revision FAO was considered as treatment failure.

RESULTS

The mean age in the dysplasia cohort was 30.7 ± 11.8 years compared to 34.5 ± 11.2 in the nondysplastic group. The mean follow-up was 4.3 years for dysplasia cohort and 4.1 for the nondysplastic group. The mean modified Harris Hip Score and Short-Form 36 Health Survey6 was significantly lower in the dysplastic group at 75.1 and 74.3 compared to 83.4 and 85.6 for the comparison group. There was a higher percentage of failure at 28.8% among dysplasia patients compared to 2.5% in the nondysplastic group.

CONCLUSION

Although labral repair and FAO may be an option for patients with hip dysplasia, the outcome in this population appears to be less optimal compared to femoroacetabular impingement patients with no evidence of dysplasia. Labral repair and osteoplasty should be limited to those with mild and borderline dysplasia.

Periacetabular Osteotomy Improves Pain and Function in Patients With Lateral Center-edge Angle Between 18° and 25°, but Are These Hips Really Borderline Dysplastic?

BACKGROUND

The treatment of mild or borderline acetabular dysplasia is controversial with surgical options including both arthroscopic labral repair with capsular closure or plication and periacetabular osteotomy (PAO). The degree to which improvements in pain and function might be achieved using these approaches may be a function of acetabular morphology and the severity of the dysplasia, but detailed radiographic assessments of acetabular morphology in patients with a lateral center-edge angle (LCEA) of 18° to 25° who have undergone PAO have not, to our knowledge, been performed.

QUESTIONS/PURPOSES

(1) Do patients with an LCEA of 18° to 25° undergoing PAO have other radiographic features of dysplasia suggestive of abnormal femoral head coverage by the acetabulum? (2) What is the survivorship free from revision surgery, THA, or severe pain (modified Harris hip score [mHHS] < 70) and proportion of complications as defined by the modified Dindo-Clavien severity scale at minimum 2-year followup? (3) What are the functional patient-reported outcome measures in this cohort at minimum 2 years after surgery as assessed by the UCLA Activity Score, the mHHS, the Hip disability and Osteoarthritis Outcome Score (HOOS), and the SF-12 mental and physical domain scores?

METHODS

Between January 2010 and December 2014, a total of 91 patients with hip pain and LCEA of 18° to 25° underwent a hip preservation surgical procedure at our institution. Thirty-six (40%) of the 91 patients underwent hip arthroscopy, and 56 hips (60%) were treated by PAO. In general, patients were considered for hip arthroscopy when symptoms were predominantly associated with femoroacetabular impingement (that is, pain aggravated by sitting and hip flexion activities) and physical examination showed a positive anterior impingement test with negative signs of instability (negative anterior apprehension test). In general, patients were considered for PAO when symptoms suggested instability (that is, pain with upright activities, abductor fatigue now aggravated by sitting) and clinical examinations demonstrated a positive anterior apprehension test. Bilateral surgery was performed in six patients and only the first hip was included in the study. One patient was excluded because PAO was performed to address dysplasia caused by surgical excision of a proximal femoral tumor associated with multiple epiphyseal dysplasia during childhood yielding a total of 49 patients (49 hips). There were 46 of 49 females (94%), the mean age was 26.5 years (± 8), and the mean body mass index was 24 kg/m (± 4.5). Radiographic analysis of preoperative films included the LCEA, Tönnis acetabular roof angle, the anterior center-edge angle, the anterior and posterior wall indices, and the Femoral Epiphyseal Acetabular Roof index. Thirty-nine of the 49 patients (80%) were followed for a minimum 2-year followup (mean, 2.2 years; range, 2-4 years) and were included in the analysis of survivorship after PAO, complications, and functional outcomes. Kaplan-Meier modeling was used to calculate survivorship defined as free from revision surgery, THA, or severe pain (mHHS < 70) at minimum 2 years after surgery. Complications were graded according to the modified Dindo-Clavien severity. Patient-reported outcomes were collected preoperatively and at minimum 2 years after surgery and included the UCLA Activity Score, the mHHS, the HOOS, and the SF-12 mental and physical domain scores.

RESULTS

Forty-six of 49 hips (94%) had at least one other radiographic feature of dysplasia suggestive of abnormal femoral head coverage by the acetabulum. Seventy-three percent of the hips (36 of 49) had two or more radiographic features of hip dysplasia aside from a LCEA of 18° to 25°. The survivorship of PAO at minimum 2 years for the 39 of 49 (80%) patients available was 94% (95% confidence interval, 80%-90%). Three of 39 patients (8%) developed a complication. At a mean of 2.2 years of followup, there was improvement in level of activity (preoperative UCLA score 7 ± 2 versus postoperative UCLA score 6 ± 2; p = 0.02). Hip symptoms and function improved postoperatively, as reflected by a higher mean mHHS (86 ± 13 versus 64 ± 19; p < 0.001) and mean HOOS (386 ± 128 versus 261 ± 117; p < 0.001). Quality of life and overall health assessed by the physical domain of the SF-12 improved (47 ± 11 versus 39 ± 12; p < 0.001). However, with the numbers available, no improvement was observed for the mental domain of the SF-12 (52 ± 8 versus 51 ± 11; p = 0.881).

CONCLUSIONS

Hips with LCEA of 18° to 25° frequently have other radiographic features of dysplasia suggestive of abnormal femoral head coverage by the acetabulum. These hips may be inappropriately labeled as "borderline" or "mild" dysplasia on consideration of LCEA alone. A more comprehensive imaging analysis in these hips by the radiographic features of dysplasia included in this study is recommended to identify hips with abnormal coverage of the femoral head by the acetabulum and to plan treatment accordingly. Patients with LCEA of 18° to 25° showed improvement in hip pain and function after PAO with minimal complications and low proportions of persistent pain or reoperations at short-term followup. Future studies are recommended to investigate whether the benefits of symptomatic and functional improvement are sustained long term.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Labral hypertrophy correlates with borderline hip dysplasia and microinstability in femoroacetabular impingement: a matched case-control analysis

PURPOSE:

The goal of this study was to: (1) investigate the association between labral hypertrophy and radiographic and computed tomography (CT) imaging measurements of dysplasia in a femoroacetabular impingement (FAI) cohort; (2) evaluate the association between physical examination parameters suggestive of microinstability and labral hypertrophy.

METHODS:

A retrospective case-control study was performed. Labral hypertrophy was defined as intraoperative labral width measuring greater >4 mm. A control cohort (NL) was matched to the cases. Physical examination parameters and preoperative radiographic and CT imaging studies were reviewed.

RESULTS:

231 hip arthroscopies for FAI were reviewed from which 42 cases of labral hypertrophy were identified (LH). In the LH group there was significantly increased hip internal rotation at 90° hip flexion compared to normal controls (13.6° ± 1 0.7° LH vs. 9.3° ± 6.2° NL; p = 0.04). On plain radiographs, the mean lateral centre-edge angle was smaller in the LH group compared to the NL group (27.6° ± 6.00° LH vs. 31.6° ± 6.59° NL; p < 0.001) and the acetabular index was larger in the LH group compared to the NL group (6.61 ± 4.18 LH vs. 4.14 ± 6.13 NL; p = 0.04). On CT imaging coronal sagittal CEA was significantly lower in LH cases compared to NL control (31.8° ± 5.30° LH vs. 35.1° ± 7.67° NL; p = 0.01).

CONCLUSIONS:

We found that patients with labral hypertrophy have radiographic and CT measurements consistent with subtle but not absolute dysplasia and physical examination findings suggestive of microinstability. We propose that labral hypertrophy can be a useful clinical tool for identifying FAI patients on the dysplasia spectrum.

Arthroscopic capsular repair using proximal advancement for instability following hip arthroscopic surgery: a case report

Arthroscopic capsular reconstruction has been reported for joint capsule tear and joint instability after hip arthroscopic surgery. However, the procedure is complicated and requires proficiency. Herein, we present a case of mild dysplasia and instability following arthroscopic surgery performed against pain due to synovitis and labral injury. The patient refused osteotomy of the hip joint, so we performed hip arthroscopic surgery using a new method of arthroscopic capsular repair using proximal advancement. A 37-year-old woman underwent hip arthroscopic surgery two times at the right side and periacetabular osteotomy at the left side. She noticed instability of the right hip joint after the second hip arthroscopic surgery. For the joint capsular management at the second surgery, which was not suitable for capsular plication, arthroscopic capsular repair using proximal advancement was performed by lifting the distal capsule to the acetabular margin. This method is less technically demanding compared with capsular reconstruction, and it can securely achieve joint stability by retensioning the joint capsule and iliofemoral ligament. Patient-reported outcomes were assessed by modified Harris hip score (mHHS), non-arthritic hip score (NAHS) and visual analog scale (VAS). The patient reported an increase in the mHHS from 35.2 pre-operatively to 90.1, the NAHS increased from 50 pre-operatively to 88.7, and the VAS score improved from 9 points pre-operatively to 1 point at 2 years post-operatively. To our knowledge, this is the first report on arthroscopic capsular repair using proximal advancement in a patient with hip instability following hip arthroscopic surgery.

Does acetabular dysplasia affect outcome in arthroscopic treatment of cam femoroacetabular impingement? Case-control study with and without acetabular dysplasia

BACKGROUND

Arthroscopic management of femoroacetabular impingement (FAI) is classically contraindicated when acetabular dysplasia is associated, although this is controversial in case of moderate dysplasia or isolated cam effect. A case-control study was therefore conducted comparing borderline (center-edgeangle (CEA), 20-24°), moderate (15-19°) and severe dysplasia (<15°) (group D) versus a control group with normal acetabular cover (CEA, 25-30°). The aims were 1) to determine functional results and satisfaction, and 2) to correlate functional results with severity of dysplasia and of cam effect.

HYPOTHESIS

Improvement in functional scores and satisfaction is lower in group D than in controls, due to non-correction of dysplasia.

MATERIAL AND METHOD

A single-center, single-surgeon retrospective comparative case-control study included all patients with isolated cam-effect FAI and dysplasia but without osteoarthritis (group D) or with isolated cam-effect FAI without dysplasia (controls) operated on during the study period. Cases of mixed impingement were excluded. Preoperative and last-follow-up functional variables included McCarthy's modified Harris Hip Score (mHHS) and Christensen's Non-Arthritic Hip Score (NAHS).

RESULTS

Between 2011 and 2014, details of 407 patients operated on by arthroscopy were entered in a data-base. Twenty patients (22 hips) were included in group D, with CEA<25° (mean, 19±3.1; range, 10-23°). The control group comprised 23 patients (25 hips) with CEA>25° (mean, 29±2.1°; range, 25-30°) matched for gender, age and body-mass index. Mean follow-up was 29.6±14.1 months (range, 14-58 months) in group D and 31.4±10.6 months (range, 15-57 months) in the control group (p=0.66). For functional scores, the two groups showed respectively 9.9 (-34 to +47) (p=0.038) and 10.4 (-20 to +48) (p=0.0038) gain in mHHS (non-significant: p=0.943). Mean gain in NAHS was 16.6 (-19 to +33) (p=0.0001) and 13.7 (-11 to +47) (p=0.0002), respectively (non-significant: p=0.56) CONCLUSION: Short-term functional results for cam FAI treatment were equivalent with<25° acetabular cover (mean, 19°; range, 13-24°) or normal cover. Longer-term assessment is indispensable to determine the impact of dysplasia and its severity.

LEVEL OF EVIDENCE

III, case-control study.

Mild or Borderline Hip Dysplasia: Are We Characterizing Hips With a Lateral Center-Edge Angle Between 18° and 25° Appropriately?

BACKGROUND

Controversy surrounds the classification and treatment of hips with a lateral center-edge angle (LCEA) between 18° and 25°. It remains undetermined as to whether periacetabular osteotomy (PAO) or arthroscopic surgery is best used to treat this patient population.

HYPOTHESIS

Patients with hip pain and mild or borderline acetabular dysplasia defined by an LCEA between 18° and 25° have different features of acetabular and femoral morphology, as determined by other relevant radiographic measures assessing the anterior and posterior acetabular walls, anterior coverage of the femoral head by the acetabulum, and femoral head and neck junction sphericity.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A retrospective review of patients who had an LCEA between 18° and 25° undergoing hip preservation between January 2010 and December 2015 with either PAO or hip arthroscopic surgery was performed. Anteroposterior, Dunn lateral, and false profile radiographs were used to measure the LCEA, Tönnis angle, anterior center-edge angle (ACEA), anterior wall index (AWI) and posterior wall index (PWI), femoral epiphyseal acetabular roof (FEAR) index and posterior to anterior wall index, and alpha angle and femoral neck-shaft angle. An agglomerative hierarchical clustering analysis was then performed on the continuous radiographic variables to identify different subtypes of hip pathomorphology among the study cohort. There were sex-specific trends in hip morphology. Therefore, we proceeded to perform separate cluster analyses for each sex. Multivariate logistic regression was used to identify radiographic parameters for distinguishing between female patients who underwent hip arthroscopic surgery versus PAO.

RESULTS

Ninety-eight patients with hip pain and an LCEA between 18° and 25° underwent surgery in the study period, 77 (78%) were female, and 81 (82%) had complete radiographs for cluster analyses. The mean age was 22.6 years. Hip arthroscopic surgery was performed in 40 (41%) patients, and PAO was performed in 58 (59%) patients. The ACEA (45%), FEAR index (34%), and AWI (30%) were the most commonly abnormal radiographic parameters among all patients. In female patients, the ACEA (55%), FEAR index (42%), and AWI (34%) were the most commonly abnormal radiographic parameters. In male patients, the PWI (48%) was the most common radiographic abnormality. For female patients, 3 clusters representing different patterns of hip morphology were identified: acetabular deficiency with cam morphology, lateral acetabular deficiency, and anterolateral acetabular deficiency. For male patients, 3 clusters were also identified: posterolateral acetabular deficiency with global cam morphology, posterolateral acetabular deficiency with focal cam morphology, and lateral acetabular deficiency without cam morphology. The ACEA (odds ratio [OR], 47.7 [95% CI, 9.6-237.6]; P < .001) and AWI (OR, 3.9 [95% CI, 1.0-15.0]; P = .049) were identified as independent factors predicting which procedure was performed in female patients.

CONCLUSION

A comprehensive evaluation of radiographic parameters in patients with an LCEA between 18° and 25° identified sex-specific trends in hip morphology and showed a large proportion of dysplastic features among these patients. An isolated assessment of the LCEA is an oversimplistic approach that may jeopardize appropriate classification and may provide insufficient data to guide the treatment of hips with additional features of dysplasia and instability.

Is Hip Arthroscopy Effective in Patients With Combined Excessive Femoral Anteversion and Borderline Dysplasia? A Match-Controlled Study

BACKGROUND

Appropriate patient selection is critical when hip arthroscopy is considered in the setting of borderline dysplasia (BD). It is presumable that excessive femoral anteversion (EFA) and BD may contraindicate arthroscopy.

HYPOTHESIS

Patients with combined EFA and BD (EFABD) demonstrate significantly inferior short-term outcomes after arthroscopic labral preservation and capsular closure when compared with a similar control group with normal lateral coverage and femoral anteversion.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Data were prospectively collected and retrospectively reviewed on patients undergoing hip arthroscopy between April 2010 and November 2014. The EFABD group's inclusion criteria were BD (lateral center-edge angle, 18°-25°), labral tear, capsular closure, and femoral version ≥20°, as well as preoperative modified Harris Hip Score, Nonarthritic Hip Score, Hip Outcome Score-Sports Specific Subscale, and visual analog scale. Exclusion criteria were workers' compensation, preoperative Tönnis grade >1, microfracture, abductor pathology, or previous ipsilateral hip surgery or conditions. Patients in the EFABD group were matched 1:2 to a similar control group with normal coverage and femoral anteversion by age at surgery ± 6 years, sex, body mass index ± 5, acetabular Outerbridge grade (0, 1 vs 2, 3, 4), and iliopsoas fractional lengthening.

RESULTS

Sixteen EFABD cases were eligible for inclusion, and 100% follow-up was obtained at ≥2 years postoperatively. Twelve EFABD cases were matched to 24 control cases. Mean femoral version was 22.4° in the EFABD group and 10.2° in the control group ( P = .01). Mean lateral center-edge angle was 22.1° in the EFABD group and 31.5° in the control group ( P < .0001). Acetabuloplasty was performed significantly more frequently in the control group ( P = .0006). No other significant differences were found regarding demographics, findings, procedures, or preoperative scores. At latest follow-up, the EFABD group demonstrated significantly lower mean modified Harris Hip Score (76.1 vs 85.9; P = .005), Nonarthritic Hip Score (74.8 vs 88.5; P < .0001), Hip Outcome Score-Sports Specific Subscale (58.3 vs 78.4; P = .02), and patient satisfaction (7.1 vs 8.3; P = .005). There were 4 secondary surgical procedures (33.3%) in the EFABD group and 1 (4.2%) in the control group ( P = .03). One patient in each group required arthroplasty.

CONCLUSION

Patients treated with arthroscopic labral preservation and capsular closure in the setting of EFABD demonstrated significant improvements from presurgery to latest follow-up. However, their results are significantly inferior when compared with a matched-controlled group. Consideration of periacetabular osteotomy or femoral osteotomy may be warranted in the setting of EFABD to achieve optimal benefit.

The Utility of Hip Arthroscopy in the Setting of Acetabular Dysplasia: A Systematic Review

PURPOSE

To compare patient-reported outcomes, progression of osteoarthritis, and conversion to total hip replacement in a dysplastic population when hip arthroscopy was used as an isolated treatment or as an adjunct to pelvic reorientation osteotomy.

METHODS

An exhaustive search of the existing literature was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Three databases (PubMed, CINAHL [Cumulative Index to Nursing and Allied Health Literature], Embase) were searched for studies from January 1930 through January 2018 published in the English language concerning the use of hip arthroscopy with diagnostic and therapeutic intentions in individuals with acetabular dysplasia. We excluded studies that presented ambiguous data sets or in which clear identification of the strategy for arthroscopy was absent.

RESULTS

The selection criteria were defined, and 33 studies (1,368 hip arthroscopies) were included in the final analysis. Studies that met the inclusion criteria were classified within 5 different categories: (1) hip arthroscopy for screening, chondral mapping, and planning (9 studies, 729 hip arthroscopies); (2) isolated arthroscopic treatment (13 studies, 434 hip arthroscopies); (3) outcomes of hip arthroscopy after previous reorientation pelvic osteotomy for acetabular dysplasia (4 studies, 52 hip arthroscopies); (4) arthroscopy followed by unplanned hip-preservation surgery (3 studies, 48 hip arthroscopies); and (5) combined arthroscopy and periacetabular osteotomy (4 studies, 106 hip arthroscopies). A risk-of-bias analysis showed a moderate to high risk of bias (level 3 or 4) within and across the included studies.

CONCLUSIONS

Although hip arthroscopy can be used to accurately grade the severity of chondral injuries in the native hip and provide zone-specific geographic mapping that may aid in subsequent surgical planning, there is insufficient evidence to conclude that arthroscopic characterization alone has any bearing on the ultimate clinical outcomes after osseous structural correction. Isolated arthroscopic treatment is not recommended in the setting of moderate to severe dysplasia, given the inferior clinical outcomes and risk of iatrogenic instability reported for this group. However, there is limited evidence to suggest that the isolated use of hip arthroscopy may be considered in cases of borderline acetabular dysplasia when careful attention is paid to labral and capsular preservation. Limited evidence supports the conclusion that after prior reorientation pelvic osteotomy for acetabular dysplasia, hip arthroscopy leads to improved clinical and functional outcomes and should be considered in this setting. Furthermore, there is insufficient evidence to conclude that failed hip arthroscopy compromises or challenges the ultimate clinical outcomes in patients undergoing subsequent reorientation pelvic osteotomy. Last, there is insufficient evidence to conclude that the adjunctive use of hip arthroscopy with reorientation pelvic osteotomy produces superior clinical outcomes compared with pelvic osteotomy alone. In summary, arthroscopic techniques may provide a useful complement to the correction of acetabular dysplasia and should be thoughtfully considered on a case-by-case basis when designing a comprehensive treatment strategy in dysplastic populations.

LEVEL OF EVIDENCE

Level IV, systematic review of Level III and IV studies.

Identification of a Patient Acceptable Symptomatic State Score for the International Hip Outcome Tool in People Undergoing Hip Arthroscopy

PURPOSE

To determine a Patient Acceptable Symptomatic State (PASS) score for the 33-item International Hip Outcome Tool (iHOT-33) in people undergoing hip arthroscopy for primary diagnoses of femoroacetabular impingement syndrome, acetabular labral tears, and/or ligamentum teres pathology.

METHODS

Consecutive participants underwent hip arthroscopy by a single surgeon between August 2011 and May 2016. Participants were included if they were between ages 18 and 60 years and underwent hip arthroscopy for femoroacetabular impingement syndrome, acetabular labral tears, or ligamentum teres pathology. Participants were excluded if they did not speak sufficient English to complete the iHOT-33, had evidence of hip dysplasia, had less than 2 mm of joint space on anteroposterior radiograph, or underwent subsequent total hip replacement surgery. Participants completed the iHOT-33 preoperatively and at a minimum of 1 to a maximum of 5 years postoperatively. Participants were also asked to answer yes or no to the external anchor question of "Taking into account all the activities you do during your daily life, your level of pain and also your functional impairment, are you satisfied with your current state following your surgery?" A receiver operating characteristic (ROC) curve was used to identify the PASS score. Multiple logistic regression was performed to determine if patient factors, primary preoperative diagnosis, or intraoperative findings predicted achievement of the PASS score.

RESULTS

A total of 117 participants undergoing hip arthroscopy were included: 72 women (61.1%) and 45 men (38.5%) with mean age of 36.81 years (18-59). Forty-two (35.9%) had cam morphology, 18 (15.4%) had pincer morphology, 78 (67.2%) had labral tears, and 97 (82.9%) had ligamentum teres tears. Mean time to final follow-up was 2.25 years (range, 1-5). The PASS score at a mean of 2.25 years postoperatively was 58 as determined by the cutoff threshold on the ROC curve with the lowest difference between sensitivity and specificity (area under the ROC curve 0.88; P < .01; 95% confidence interval [CI], 0.81-0.95). No factors were predictors of achievement of the PASS score in this study (P > .05), including age (odds ratio [OR], 0.71; 95% CI, 0.32-1.56), sex (OR, 1.02; 95%, CI 0.98-1.06), preoperative iHOT-33 score (OR, 1.002; 95% CI, 0.98-1.03), primary preoperative diagnosis (OR, 0.86; 95% CI, 0.53-1.40), cam morphology (OR, 1.19; 95% CI, 0.54-2.64), Pincer morphology (OR, 0.50; 95%, CI 0.18-1.38), acetabular labral tears (OR, 1.93; 95% CI, 0.88-4.26), Outerbridge grade 3-4 chondral damage (OR, 0.97; 95% CI, 0.42-2.25), and ligamentum teres pathology (OR, 0.95; 95% CI, 0.35-2.61).

CONCLUSIONS

This study reports a PASS score of 58 for the iHOT-33 at 2 years following hip arthroscopy. The PASS score will assist in assessing response to hip arthroscopy in research and clinical settings.

LEVEL OF EVIDENCE

Level II, retrospective prognostic study.

Previous failed hip arthroscopy negatively impacts early patient-reported outcomes of the periacetabular osteotomy: an ANCHOR Matched Cohort Study

Surgical treatment of hip dysplasia by arthroscopic procedures remains controversial. The aim of this study was to compare outcomes of periacetabular osteotomy (PAO) after failed hip arthroscopy to a matched-control group without previous arthroscopy. Fifty-two patients who underwent PAO after failed hip arthroscopy were matched to two subjects without arthroscopy based on age, sex, BMI and radiographic severity. Pre- and post-operative patient self-reported outcomes and radiographic parameters were compared at minimum 1-year follow-up. Prior to PAO the failed hip arthroscopy group exhibited lower modified Harris hip scores (mHHS; 57 versus 62; P = 0.04), WOMAC (59.9 versus 66.3; P = 0.08), UCLA activity (5 versus 7; P = 0.001) and SF12 physical scores (34 versus 40; P = 0.001) compared with the non-arthroscopy group. At minimum 1-year follow-up, the failed hip arthroscopy group had lower mHHS (78 versus 87; P = 0.003); worse WOMAC (84.1 versus 90.8; P = 0.02) and SF-12 physical component (46 versus 50; P = 0.02) with similar UCLA (7 versus 8; P = 0.21) compared with the non-arthroscopy group. No differences were detected regarding radiographic parameters or in patient-reported outcomes from preoperative to follow up. PAO achieved the desired radiographic correction and significant improvement in pain and function after a failed previous hip arthroscopy, however, the patient-reported outcomes were inferior to those of PAO without previous failed arthroscopy.

Prevalence of High-Grade Cartilage Defects in Patients With Borderline Dysplasia With Femoroacetabular Impingement: A Comparative Cohort Study

PURPOSE

To compare the prevalence, size, and location of Outerbridge grade III and IV cartilage defects on the femoral head and acetabulum between patients with borderline acetabular dysplasia and patients with non-borderline dysplasia who underwent hip arthroscopy for femoroacetabular impingement (FAI).

METHODS

Patients aged 18 years or older who underwent primary hip arthroscopy for correction of FAI and labral repair from November 2005 to April 2016 were included. We excluded patients with previous hip surgery, a radiographic hip joint space of 2 mm or less, and/or a lateral center-edge angle (LCEA) of less than 20° or greater than 40°. The study patients were divided into 2 groups based on the LCEA on the anteroposterior pelvic radiograph: Patients with an LCEA between 20° and 25° were included in the borderline group, and patients with an LCEA between 25° and 40° were included in the non-borderline group. The prevalence, size, and location of Outerbridge grade III and IV chondral lesions on the femoral head and acetabulum were recorded intraoperatively. Comparisons between groups were performed with the Mann-Whitney U test for nonparametric testing and the t test for data that were normally distributed. Data were analyzed to calculate odds ratios associated with the various factors.

RESULTS

In total, 2,429 patients (1,114 women and 1,315 men) met the inclusion criteria. The borderline group consisted of 305 patients (150 men and 155 women), whereas the non-borderline dysplasia group comprised 2,124 patients (1,165 men and 959 women). Outerbridge grade III and IV chondral lesions were found on the femoral head in 118 patients with borderline dysplasia (39%) and 127 patients with non-borderline dysplasia (6%) and on the acetabulum in 132 patients with borderline dysplasia (43%) and 874 patients with non-borderline dysplasia (41%). Patients with borderline dysplasia were 10 times more likely (95% confidence interval, 7.3-13.4; P < .001) to have a grade III or IV cartilage defect on the weight-bearing surface of the femoral head (P < .001) than patients with non-borderline dysplasia. On the acetabular side, no difference in the prevalence of severe cartilage damage was detected between the 2 groups (P = .588). The size of chondral damage was significantly greater in patients with borderline dysplasia on the acetabulum (P = .039) compared with the non-borderline dysplasia group.

CONCLUSIONS

Patients with FAI and borderline dysplasia are at higher risk of having Outerbridge grade III and IV chondral damage on the femoral head than patients with non-borderline dysplastic hips. Borderline dysplastic hips also presented with significantly larger chondral defects on the acetabular surface.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

The interface between periacetabular osteotomy, hip arthroscopy and total hip arthroplasty in the young adult hip

Hip pain is highly prevalent in both the younger and the elderly population. In older patients, pain arising from osteoarthritis (OA) is most frequent, whereas in younger patients, non-degenerative diseases are more often the cause of pain. The pain may be caused by hip dysplasia and femoroacetabular impingement (FAI).Abnormal mechanics of the hip are hypothesized by some authors to cause up to 80% of OA in the hip. Therefore, correction of these abnormalities is of obvious importance when treating young patients with hip pain.Hip dysplasia can be diagnosed by measuring a CE angle < 25° on a plain standing radiograph of the pelvis.Dysplastic or retroverted acetabulum with significant symptoms should receive a periacetabular osteotomy (PAO).FAI with significant symptoms should be treated by adequate resection and, if necessary, labrum surgery.If risk factors for poor outcome of joint-preserving surgery are present (age > 45 to 50 years, presence of OA, joint space < 3 mm or reduced range of motion), the patient should be offered a total hip arthroplasty (THA) instead of PAO.THA can be performed following PAO with outcomes similar to a primary THA.Hip arthroscopy is indicated in FAI (cam and pincer) and/or for labral tears. Cite this article: EFORT Open Rev 2018;3:408-417. DOI: 10.1302/2058-5241.3.170042.

Does acetabular coverage influence the clinical outcome of arthroscopically treated cam-type femoroacetabular impingement (FAI)?

Aims

What represents clinically significant acetabular undercoverage in patients with symptomatic cam-type femoroacetabular impingement (FAI) remains controversial. The aim of this study was to examine the influence of the degree of acetabular coverage on the functional outcome of patients treated arthroscopically for cam-type FAI.

Patients and Methods

Between October 2005 and June 2016, 88 patients (97 hips) underwent arthroscopic cam resection and concomitant labral debridement and/or refixation. There were 57 male and 31 female patients with a mean age of 31.0 years (17.0 to 48.5) and a mean body mass index (BMI) of 25.4 kg/m² (18.9 to 34.9). We used the Hip2Norm, an object-oriented-platform program, to perform 3D analysis of hip joint morphology using 2D anteroposterior pelvic radiographs. The lateral centre-edge angle, anterior coverage, posterior coverage, total femoral coverage, and alpha angle were measured for each hip. The presence or absence of crossover sign, posterior wall sign, and the value of acetabular retroversion index were identified automatically by Hip2Norm. Patient-reported outcome scores were collected preoperatively and at final follow-up with the Hip Disability and Osteoarthritis Outcome Score (HOOS).

Results

At a mean follow-up of 2.7 years (1 to 8, sd 1.6), all functional outcome scores significantly improved overall. Radiographically, only preoperative anterior coverage had a negative correlation with the improvement of the HOOS symptom subscale (r = -0.28, p = 0.005). No significant difference in relative change in HOOS subscale scores was found according to the presence or absence of radiographic signs of retroversion.

Discussion

Our study demonstrated the anterior coverage as an important modifier influencing the functional outcome of arthroscopically treated cam-type FAI. Cite this article: Bone Joint J 2018;100-B:831-8.

The management of the painful borderline dysplastic hip

Improved imaging and the evolution of surgical techniques have permitted a rapid growth in hip preservation surgery over the last few decades. The management of the painful borderline dysplastic hip however remains controversial. In this review, we will identify the pertinent issues and describe the patient assessment and treatment options. We will provide our own recommendations and also identify future areas for research.

Does Severity of Acetabular Dysplasia Influence Clinical Outcomes After Periacetabular Osteotomy?-A Case-Control Study

BACKGROUND

Detailed characterization of factors influencing post-periacetabular osteotomy (PAO) outcome could guide treatment offered.

METHODS

Using a prospective, multicenter database of PAOs, 61 hips/patients (51 females) with lesser dysplasia (acetabular index < 15° and lateral center-edge angle > 15°) were case-control matched for age, gender, body mass index, Tönnis grade, and joint congruency (P = .6-.9) with a "comparison group" of pronounced dysplasia (n = 183), aiming to assess whether severity of acetabular dysplasia has an effect on outcome following PAO and/or the ability to achieve desired acetabular correction.

RESULTS

At 4 ± 1.5 years, no differences in complication or reoperation rates were detected between the groups (P = .29). Lesser dysplastic hips had inferior Hip Disability and Osteoarthritis Outcome Score, both preoperatively (52 vs 59) and postoperatively (73 vs 78); however, similar improvements were seen. Among the lesser dysplastic hips, those that required a femoral osteochondroplasty at PAO had significantly inferior preoperative Hip Disability and Osteoarthritis Outcome Score (48 ± 18). Increased ability to achieve optimum correction was seen (80% vs 59%, P = .4) in lesser dysplasia.

CONCLUSION

A PAO is safe and efficacious in the treatment of lesser dysplasia. Further study on the identification of the optimum treatment modality for the mildly dysplastic hips with cam deformity is required.

Progressive osteoarthritis during pregnancy several years following hip arthroscopy for femoroacetabular impingement

Case

A 28-year-old with borderline left hip dysplasia who underwent arthroscopic acetabuloplasty, femoral osteochondroplasty, and labral repair for femoroacetabular impingement. She did well for 8 years, though required arthroscopic capsulolabral adhesion release 2 years after the initial procedure. After this period of stability, she developed left hip pain during pregnancy. Radiographs demonstrated progressive osteoarthritis that lead to total hip arthroplasty at age 37.

Conclusion

The physiologic and hormonal changes during pregnancy leading to increased ligamentous laxity may put vulnerable patients with hip dysplasia and iatrogenic instability at increased risk for progression of osteoarthritis.

Hip arthroscopy for femoroacetabular impingement

The purpose of this article is to give a general overview of femoroacetabular impingement (FAI) and how it could be treated arthroscopically, with some details about indications, the procedure itself and some of the complications associated with the surgery.

FAI is a dynamic condition of the hip that can be a source of pain and disability and could potentially lead to arthritis.

When symptomatic, and if conservative treatment fails, FAI can be addressed surgically.

The goal of surgical treatment for FAI is to recreate the spherical contour of the femoral head, improve femoral offset, normalize coverage of the acetabulum, repair/reconstruct chondral damage and repair/reconstruct the labrum to restore normal mechanics and joint sealing.

Advances in equipment and technique have contributed to an increase in the number of hip arthroscopy procedures performed worldwide and have made it one of the more common treatment options for symptomatic FAI.

Hip arthroscopy is a procedure with an extremely steep and long learning curve.

Cite this article: EFORT Open Rev 2018;3:121-129. DOI: 10.1302/2058-5241.3.170041

Clinical outcomes following arthroscopic treatment of femoro-acetabular impingement using a minimal traction approach and an initial capsulotomy. Minimum two year follow-up

PURPOSE

Although the arthroscopic management of femoroacetabular impingement (FAI) is increasing, severe complications have been reported due to traction. We developed an arthroscopic technique based on an initial capsulotomy and a minimal traction approach. The main purpose of this study was to analyze the clinical outcomes of FAI treatment using this technique after at least two years of follow-up.

METHODS

Forty-seven consecutive patients underwent surgery for FAI. There were two initial portals: a proximal anterolateral portal and a distal anterior instrumental portal. An anterior working space was created and a T-shaped incision was made in the anterior capsule to relieve joint distraction. Short traction (less than 20 mn) made it possible to approach the central compartment. Acetabuloplasty was performed in the presence of pincer impingement. Traction was then released. A head-neck femoral osteochondroplasty was performed in case of bump impingement. All patients underwent a mean 3.3 ± one years of follow-up based on two self-administered questionnaires: the Harris hip score and the QOL Oxford score. None of the patients were lost to follow-up.

RESULTS

There were three complications: two ossifications and one case of injury to the femoral cutaneous nerve with good clinical outcomes at the final follow-up. Five patients (10%) underwent surgical revision after a mean 1.4 years of follow-up: three total hip arthroplasties, one peri-acetabular osteotomy, and one repeat arthroscopic hip debridement. The Harris score increased significantly from 60 ± 10 to 86 ± 15 (p < 0.0001) and the Oxford score improved from 34 ± 15 to 50 ± 11. Only 25% of patients had a "forgotten hip" at the final follow-up.

CONCLUSION

Our clinical results were comparable to previously reported outcomes with other surgical techniques for the management of FAI. However, it should also be noted that despite these good clinical outcomes, the percentage of patients with a "forgotten hip" is low, and patients should be informed of this.

Should Acetabular Retroversion Be Treated Arthroscopically? A Systematic Review of Open Versus Arthroscopic Techniques

PURPOSE

To compare patient-reported outcomes, progression of radiographic arthritis, revision rates, and complications for hips with acetabular retroversion treated by open versus arthroscopic methods.

METHODS

The PubMed and EMBASE databases were searched in August 2016 for literature on the open and arthroscopic techniques using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) method. All studies published in the English language that focused on the surgical treatment of femoroacetabular impingement caused by retroversion were included. All arthroscopic procedures, such as acetabuloplasty and labral repair, and open procedures, including anteverting periacetabular osteotomy and surgical dislocation with osteoplasty, were included. Articles that did not describe how retroversion was defined were excluded, as were studies with less than 6 months' follow-up and fewer than 5 patients. Two authors screened the results and selected articles for this review based on the inclusion and exclusion criteria. All results were scored using the Methodological Index for Non-randomized Studies (MINORS) criteria.

RESULTS

There were 386 results returned and 15 articles that met the inclusion criteria of this study. Among the studies, 11 reviewed arthroscopic techniques and 4 reviewed open surgical procedures. Both techniques yield good results based on patient-reported outcomes with minimal progression of osteoarthritis and low complication rates.

CONCLUSIONS

This review showed statistically and clinically significant improvements for the treatment of acetabular retroversion based on patient-reported outcomes, with low progression of radiographic arthritis, revision rates, and complications using both open and arthroscopic methods.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I to IV studies.

Intermediate-Term Hip Survivorship and Patient-Reported Outcomes of Periacetabular Osteotomy: The Washington University Experience

BACKGROUND

The Bernese periacetabular osteotomy (PAO) is an alternative to arthroplasty for treating symptomatic acetabular dysplasia, but there have been few studies on the intermediate-term outcomes of this procedure. In the present study, we assessed intermediate-term hip survival and patient-reported outcomes of PAO used to treat symptomatic acetabular dysplasia.

METHODS

From July 1994 to August 2008, 238 hips (206 patients) were treated with PAO. Sixty-two had a diagnosis other than classic acetabular dysplasia, and 22 were lost to follow-up. The remaining 154 hips (129 patients) were evaluated at an average of 10.3 years postoperatively. Kaplan-Meier analysis was used to assess survivorship with an end point of total hip arthroplasty (THA). Hips were evaluated using the University of California at Los Angeles (UCLA) Activity Score, modified Harris hip score (mHHS), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale score. A WOMAC pain subscale score of ≥10 and/or an mHHS of ≤70 were considered to indicate a clinically symptomatic hip.

RESULTS

Kaplan-Meier analysis revealed a hip survival rate of 92% (95% confidence interval [CI]: 82% to 97%) at 15 years postoperatively. Eight hips (5%) underwent THA at a mean (and standard deviation) of 6.8 ± 5.2 years. Twenty-four additional hips (16%) were considered symptomatic based on a WOMAC pain score of ≥10 and/or an mHHS of ≤70. One hundred and twenty-two hips (79%) did not undergo THA and did not meet the criteria for symptoms, and these hips had a mean mHHS of 92.4 ± 8.4, WOMAC pain subscale score of 1.2 ± 1.9, and UCLA Activity Score of 7.7 ± 2.0 at a mean of 10.1 years. A higher risk of failure was associated with fair or poor preoperative joint congruency (odds ratio [OR]: 8.65; 95% CI: 1.18 to 63.55; p = 0.034) and with a postoperative lateral center-edge angle of >38° (OR: 8.04; 95% CI: 2.01 to 32.22). A concurrent head-neck osteochondroplasty was associated with a decreased risk of failure (OR: 0.27; 95% CI: 0.09 to 0.78; p = 0.016).

CONCLUSIONS

This study demonstrates the durability of the Bernese PAO. Fair or poor preoperative joint congruency and excessive postoperative femoral head coverage were found to be predictors of failure, while concurrent head-neck osteochondroplasty in patients with an inadequate range of motion after PAO was associated with a decreased risk of failure.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Editorial Commentary: Hip Arthroscopy in Hip Dysplasia: Just Because You Are Doing It, Should You?

As surgeons advance the field of hip arthroscopy and perform more hip arthroscopy in patients with hip dysplasia and associated femoroacetabular impingement, we need to publish more outcome studies to determine this procedure's success and safety in this specific group of patients.

Hip Arthroscopic Surgery With Labral Preservation and Capsular Plication in Patients With Borderline Hip Dysplasia: Minimum 5-Year Patient-Reported Outcomes

BACKGROUND

The arthroscopic management of hip dysplasia has been controversial and has historically demonstrated mixed results. Studies on patients with borderline dysplasia, emphasizing the importance of the labrum and capsule as secondary stabilizers, have shown improvement in patient-reported outcomes (PROs). Purpose/Hypothesis: The purpose was to assess whether the results of hip arthroscopic surgery with labral preservation and concurrent capsular plication in patients with borderline hip dysplasia have lasting, positive outcomes at a minimum 5-year follow-up. It was hypothesized that with careful patient selection, outcomes would be favorable.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Data were prospectively collected and retrospectively reviewed for patients aged <40 years who underwent hip arthroscopic surgery for intra-articular abnormalities. Inclusion criteria included lateral center-edge angle (LCEA) between 18° and 25°, concurrent capsular plication and labral preservation, and minimum 5-year follow-up. Exclusion criteria were severe dysplasia (LCEA ≤18°), Tönnis grade ≥2, pre-existing childhood hip conditions, or prior hip surgery. PRO scores including the modified Harris Hip Score (mHHS), Non-Arthritic Hip Score (NAHS), and Hip Outcome Score Sport-Specific Subscale (HOS-SSS) and the visual analog scale (VAS) score for pain were collected preoperatively, at 3 months, and annually thereafter. Complications and revisions were recorded.

RESULTS

Twenty-five hips (24 patients) met the inclusion criteria. Twenty-one hips (19 patients, 84%) were available for follow-up. The mean age at surgery was 22.9 years. The mean preoperative LCEA and Tönnis angle were 21.7° (range, 18° to 24°) and 6.9° (range, -1° to 16°), respectively. The mean follow-up was 68.8 months. The mean mHHS increased from 70.3 to 85.9 ( P < .0001), the mean NAHS from 68.3 to 87.3 ( P < .0001), and the mean HOS-SSS from 52.1 to 70.8 ( P = .0002). The mean VAS score improved from 5.6 to 1.8 ( P < .0001). Four hips (19%) required secondary arthroscopic procedures, all of which resulted in improved PRO scores at latest follow-up. No patient required conversion to total hip arthroplasty.

CONCLUSION

While periacetabular osteotomy remains the standard for treating true acetabular dysplasia, hip arthroscopy may provide a safe and durable means of managing intra-articular abnormalities in the setting of borderline acetabular dysplasia at midterm follow-up. These procedures should be performed by surgeons with expertise in advanced arthroscopic techniques, using strict patient selection criteria, with emphasis on labral preservation and capsular plication.

Hip Dysplasia: Prevalence, Associated Findings, and Procedures From Large Multicenter Arthroscopy Study Group

PURPOSE

To report observational findings of patients with acetabular dysplasia undergoing hip arthroscopy.

METHODS

We performed a comparative case series of multicenter registry patients from January 2014 to April 2016 meeting the inclusion criteria of isolated hip arthroscopy, a documented lateral center-edge angle (LCEA), and completion of preoperative patient-reported outcome measures. A retrospective analysis compared range of motion, intra-articular pathology, and procedures of patients with dysplasia (LCEA ≤25°) and patients without dysplasia (LCEA >25°).

RESULTS

Of 1,053 patients meeting the inclusion criteria, 133 (13%) had dysplasia with a mean LCEA of 22.8° (standard deviation, 2.4°) versus 34.6° (standard deviation, 6.3°) for non-dysplasia patients. There were no statistically significant differences in preoperative modified Harris Hip Score, International Hip Outcome Tool-12 score, or visual analog scale score (pain). Cam deformity occurred in 80% of dysplasia patients. There was a significant difference in internal rotation between the dysplasia (21°) and non-dysplasia groups (16°, P < .001). Mean internal rotation (33.5°; standard deviation, 15.6°) of the dysplastic subjects without cam morphology was greater than that of the dysplastic patients with cam morphology (18.5°; standard deviation, 11.6°; P < .001). Hypertrophic labra were found more commonly in dysplastic (33%) than non-dysplastic hips (11%, P < .001). Labral tears in patients with dysplasia were treated by repair (76%), reconstruction (13%), and selective debridement (11%); labral treatments were not significantly different between cohorts. The most common nonlabral procedures included femoroplasty (76%) and synovectomy (73%). There was no significant difference between the dysplasia and non-dysplasia groups regarding capsulotomy types and capsular closure rates (96% and 92%, respectively).

CONCLUSIONS

Dysplasia, typically of borderline to mild severity, comprises a significant incidence of surgical cases (13%) by surgeons performing high-volume hip arthroscopy. Despite having similar preoperative pain and functional profiles to patients without dysplasia, dysplasia patients may have increased flexed-hip internal rotation. Commonly associated cam morphology significantly decreases internal rotation. Arthroscopic labral repair, femoroplasty, and closure of interportal capsulotomy are the most commonly performed procedures.

LEVEL OF EVIDENCE

Level III, therapeutic comparative case series.

Predictors of Poor Clinical Outcome After Arthroscopic Labral Preservation, Capsular Plication, and Cam Osteoplasty in the Setting of Borderline Hip Dysplasia

BACKGROUND

Borderline developmental dysplasia of the hip (BDDH) is frequently diagnosed concurrently with cam impingement. While hip arthroscopy has advanced the treatment of hip joint pathology, including femoroacetabular impingement (FAI), arthroscopic treatment for FAI in the setting of BDDH remains a challenge amid a subset of patients. The risk factors of poor clinical results after hip arthroscopic labral preservation and FAI corrections in the setting of BDDH patients have not been well established.

HYPOTHESIS

Pre- and intraoperative findings can predict the poor clinical outcomes after hip arthroscopic surgery for FAI in the setting of BDDH.

STUDY DESIGN

Case control study; Level of evidence, 3.

METHODS

Of patients with BDDH (defined as lateral center edge [LCE] angle between 20° and 25°) who underwent arthroscopic procedures for FAI between 2009 and 2014, 45 met inclusion criteria (45 hips: 15 males and 30 females). Their mean age was 31.4 years (range, 12-65 years), and the mean LCE angle was 23.2°. Clinical and radiographic follow-up evaluations up to a minimum of 2 years after surgery were performed for all patients. Failure of the procedure was defined as conversion to subsequent surgery or having a Tönnis osteoarthritis grade of 2, and success was defined as patients who did not need subsequent surgery. Univariate analysis and Cox hazard proportional analysis were performed for both cohorts.

RESULTS

Of 45 patients, 11 (24%) had revision surgery (endoscopic shelf acetabuloplasty for 5 patients, total hip arthroplasty for 2, and revision hip arthroscopy for 2) or advanced to Tönnis grade ≥2 osteoarthritis and thus constituted the failure group. In the success group, modified Harris Hip Score (median, pre- vs postoperative: 72.1 vs 100, P< .001, Wilcoxon signed-rank test) and nonarthritic hip score (58.8 vs 98.8, P< .001) were significantly improved at the minimum 2-year follow-up. The median age of the failure group was significantly higher than that of the success group (47.0 vs 20.0, P< .001, Mann-Whitney Utest). Risk factors of poor clinical outcomes were identified as follows: age ≥42 years (hazard ratio [HR], 11.6; 95% CI, 2.5-53.9; P= .002, Cox hazard model), broken Shenton line (HR, 6.4; 95% CI, 1.9-22.3; P= .003), Tönnis angle ≥15° (HR, 3.9; 95% CI, 1.2-12.9; P= .03), vertical center anterior (VCA) angle ≤17° (HR, 5.0; 95% CI, 1.5-17.1; P= .01), Tönnis grade 1 at preoperative radiograph (HR, 3.6; 95% CI, 1.1-11.7; P= .04), severe cartilage delamination at acetabulum (HR, 11.8; 95% CI, 3.0-46.1; P< .001), and mild cartilage damage at femoral head (HR, 8.1; 95% CI, 2.1-30.8; P= .002).

CONCLUSION

Preoperative predictors of poorer outcomes from hip arthroscopic labral preservation, capsular plication, and cam osteoplasty in the setting of BDDH are age ≥42 years old, broken Shenton line, osteoarthritis, Tönnis angle ≥15°, and VCA angle ≤17° on preoperative radiographs. Intraoperative predictors of poorer outcomes are severe acetabular chondral damage and even mild femoral chondral damage. Although the patients in the setting of BDDH may have good outcomes from isolated hip arthroscopy, caution is suggested for those with the aforementioned risk factors.

Endoscopic shelf acetabuloplasty can improve clinical outcomes and achieve return to sports-related activity in active patients with hip dysplasia

PURPOSE

To investigate clinical outcomes and return to sports-related activity following endoscopic shelf acetabuloplasty combined with labral repair in the treatment of the active patients with developmental dysplasia of the hip (DDH).

METHODS

Between 2011 and 2013, 32 patients (36 hips; 11 males and 21 females; 11 right 17 left 4 bilateral; median age 28.5, range 12-51 years), who underwent endoscopic shelf acetabuloplasty combined with labral repair and met the inclusion criteria were enrolled in this study. There was a minimum follow-up of 2 years (average 32.3 ± 3 months, range 24-48 months). Patient-reported outcome (PRO) scores including the modified Harris Hip Score (MHHS) and Non-Arthritis Hip Score (NAHS) were obtained preoperatively and at final follow-up for the assessment of surgical outcomes.

RESULTS

The mean MHHS significantly improved from 68.4 ± 14.3 (range 23.1-95.7) preoperatively to 94.5 ± 8.5 (range 66-100) at final follow-up (p = 0.001). Similarly, the NAHS also significantly improved from 51.3 ± 11.9 (range 23-76) preoperatively to 73.0 ± 7.4 (range 44-80) at final follow-up (p = 0.001). The mean LCE angle significantly increased postoperatively but partially decreased at final follow-up (mean preoperative versus postoperative versus final follow-up: 16.0 range 5-24, versus 40.1 range 27-58, versus 30.1 range 20-41. p = 0.001, respectively). There were 3 patients who returned to a higher activity level, 20 patients who returned to the same activity level, and 6 patients who returned to a lower activity level. The mean period from surgery to return to play was 9.0 ± 3.5 months (range 5-18).

CONCLUSION

Endoscopic shelf acetabuloplasty provides promising clinical outcomes and return to sports-related activity for active patients with DDH.

LEVEL OF EVIDENCE

Level IV.

Hip dysplasia in wrestlers: three lessons learned

Hip problems due to dysplasia are commonly associated with female athletes in sports demanding supraphysiologic motion, such as ballet, gymnastics and figure skating. However, hip problems are rarely mentioned among wrestlers, a male sport in which flexibility is advantageous. Dysplasia may have a mostly unrecognized prevalence among wrestlers that can lead to problems and benefit from reorientation periacetabular osteotomy (PAO). Study design in this research is Level 4 evidence case reports. Three consecutive intercollegiate wrestlers ages 20, 21 and 22 years underwent PAO for dysplasia and are reported. Two underwent concomitant arthroscopy. Each returned successfully to intercollegiate wrestling at 6, 8 and 11 months. There were no complications. This work concludes that dysplasia has an unknown but mostly unrecognized prevalence among wrestlers. With proper recognition and treatment with PAO, there is a reasonable expectation that they could return to wrestling.

Modifications to the Hip Arthroscopy Technique When Performing Combined Hip Arthroscopy and Periacetabular Osteotomy

In the realm of hip preservation, hip arthroscopy is often used to address intra-articular impingement pathology, whereas periacetabular osteotomy (PAO) is used to address dysplasia and instability. Indications to combine these 2 procedures include hip dysplasia and symptomatic instability with a concomitant symptomatic labral tear or the other symptomatic intra-articular pathology (i.e., loose body, chondral flap). The arthroscopic portion of the procedure allows repair of the injured labrum and close inspection of the hip joint, and the PAO addresses undercoverage and/or inappropriate version of the acetabulum. The open approach used in PAO also allows access to the peripheral compartment to debride a cam lesion, if present, and the subspine region is accessible to perform subspine decompression, if needed. In this technique, we highlight special considerations pertaining to hip arthroscopy that is performed in combination with a PAO. Hip arthroscopy is the first procedure that takes place in this combined case, and modifications to the standard hip arthroscopic technique can prevent unnecessary difficulty during the PAO that follows.

A Traffic Light Grading System of Hip Dysplasia to Predict the Success of Arthroscopic Hip Surgery

BACKGROUND

The role of hip arthroscopic surgery in dysplasia is controversial.

PURPOSE

To determine the 7-year joint preservation rate after hip arthroscopic surgery in hip dysplasia and identify anatomic and intraoperative features that predict the success of hip preservation with arthroscopic surgery, allowing the formulation of an evidence-based classification system.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Between 2008 and 2013, 111 hips with dysplastic features (acetabular index [AI] >10° and/or lateral center-edge angle [LCEA] <25°) that underwent arthroscopic surgery were identified. Clinical, radiological, and operative findings and the type of procedure performed were reviewed. Radiographic evaluations of the operated hip (AI, LCEA, extrusion index) were performed. Outcome measures included whether the hip was preserved (ie, did not require arthroplasty) at follow-up and the preoperative and postoperative Non-Arthritic Hip Score (NAHS) and Hip disability and Osteoarthritis Outcome Score (HOOS). The AI and LCEA were calculated, factored by a measure of articular wear (AI_f and LCEA_f, respectively), according to the University College Hospital, London (UCL) grading system as follows: AI_f = AI × (number of UCL wear zones + 1), and LCEA_f = LCEA / (number of UCL wear zones + 1). A contour plot of the resulting probability value of failure for every combination of AI_f and LCEA_f allowed for the determination of the zones with the lowest and highest incidences of failure to preserve the hip.

RESULTS

The mean AI and LCEA were 9.8° and 18.0°, respectively. At a mean follow-up of 4.5 years (range, 0.4-8.3 years), 33 hips had failed, requiring hip arthroplasty. The 7-year joint survival rate was 68%. The mean improvements in the NAHS and HOOS were 11 ( P = .001) and 22.8 ( P < .001) points, respectively. The zone with the greatest chance of joint preservation (odds ratio, 10; P < .001) was the green zone, with an AI_f of 0° to 15° and an LCEA_f of 15° to 25°; in contrast, the zone with the greatest chance of failure (odds ratio, 10; P < .001) was the red zone, with an AI_f of 20° to 100° and an LCEA_f of 0° to 10°.

CONCLUSION

Overall, the 7-year hip survival rate in hip dysplasia appears inferior compared with that reported in femoroacetabular impingement (78%). Hip arthroscopic surgery is associated with an excellent chance of hip preservation in mild dysplasia (green zone: AI = 0°-15°, LCEA = 15°-25°) and no articular wear. The authors advise that the greatest caution should be used when considering arthroscopic options in cases of severe dysplasia (red zone: AI >20° and/or LCEA <10°).

Do Ligamentum Teres Tears Portend Inferior Outcomes in Patients With Borderline Dysplasia Undergoing Hip Arthroscopic Surgery? A Match-Controlled Study With a Minimum 2-Year Follow-up

BACKGROUND

Arthroscopic surgery in borderline dysplastic hips remains controversial, but the role of the ligamentum teres (LT) has not been studied in this setting.

HYPOTHESIS

Borderline dysplastic patients with LT tears have worse short-term outcomes than those without LT tears.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Data were prospectively collected on patients who underwent arthroscopic surgery between February 2008 and April 2014. The inclusion criteria were borderline dysplasia (lateral center-edge angle [LCEA], 18°-25°) and labral tears; arthroscopic treatments including labral preservation and capsular plication; and preoperative patient-reported outcome scores including the modified Harris Hip Score (mHHS), Non-Arthritic Hip Score (NAHS), Hip Outcome Score-Sport-Specific Subscale, and visual analog scale for pain. Patients were excluded for preoperative Tönnis osteoarthritis grade >0, workers' compensation claims, previous ipsilateral hip surgery and conditions, or frank dysplasia (LCEA <18°). Patients with LT tears were pair-matched to patients without tears for sex, age at surgery ±10 years, body mass index (<30 kg/m² vs ≥30 kg/m²), labral treatment type, and microfracture.

RESULTS

Of 68 eligible patients, 63 (93%) had a minimum 2-year follow-up, and 30 (48%) had LT tears. Twenty patients in each group were pair-matched. The mean follow-up time was 54.3 months (range, 24.2-83.8 months) for the LT tear group and 38.6 months (range, 24.6-70.6 months) for the control group ( P = .002). Ninety percent were female. There were no significant differences regarding demographics or intra-operative procedures. The LT tear group trended toward lower postoperative mHHS ( P = .09) and NAHS ( P = .09) values. Mean satisfaction was 8.1 for the LT tear group and 7.9 for the control group. Preoperative and follow-up scores were not significantly different between the groups. The LT tear group had 5 revisions, with 1 revision in the control group. Three patients (15%) in the LT tear group underwent total hip arthroplasty (THA); no patients in the control group required THA.

CONCLUSION

In borderline dysplastic patients undergoing hip arthroscopic surgery with labral treatment and capsular plication, LT tears may indicate advanced instability and portend slightly inferior outcomes when compared with a match-controlled group. Borderline dysplastic patients with LT tears may have increased propensities toward revision arthroscopic surgery and conversion to THA. LT tears in these patients may warrant consideration for additional procedures including periacetabular osteotomy and LT reconstruction.