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

Primary Hip Arthroscopy in Patients With Acetabular Dysplasia: A Systematic Review of Published Clinical Outcomes at Minimum 5-Year Follow-up

BACKGROUND

Hip arthroscopy in patients with borderline hip dysplasia has satisfactory outcomes at short-term follow-up; however, the data on midterm outcomes are inconsistent, and failure rates are high in some studies, limiting understanding of the role and utility of hip arthroscopy in this patient cohort.

PURPOSE

To provide an up-to-date, evidence-based review of the clinical outcomes of primary hip arthroscopy in patients with frank or borderline hip dysplasia at ≥5-year follow-up and report the failure rate and progression to total hip arthroplasty in this cohort.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A comprehensive literature search was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Studies were included if they evaluated outcomes of primary hip arthroscopy in patients with lateral center-edge angle (LCEA) <25° at ≥5-year follow-up. Risk of bias assessment was performed using the methodological index for non-randomized studies scoring system. Level of evidence was determined using criteria from the Oxford Centre for Evidence-Based Medicine.

RESULTS

Nine studies were included in this review. Patients with LCEA <25° demonstrated satisfactory clinical outcomes, high patient satisfaction, and significant postoperative improvements in patient-reported outcomes (PROs) at follow-up ranging from a ≥5 to 10 years. Studies comparing patients with dysplasia to those without did not demonstrate significant differences in preoperative, postoperative, or delta PROs or in failure, reoperation, or revision rates. There was no overall significant correlation between outcomes and LCEA stratification.

CONCLUSION

Hip arthroscopy in carefully selected patients with LCEA <25° can be successful at mid- to long-term follow-up and may provide clinical outcomes and failure rates comparable with patients with normal LCEA, understanding that this is a singular, 2-dimensional radiographic measure that does not differentiate instability from impingement or combinations thereof, warranting future studies delineating these differences. These findings suggest that hip dysplasia may not be an absolute contraindication for isolated hip arthroscopy and may serve as a viable intervention with consideration of staged future periacetabular osteotomy (PAO). Importantly, this review does not suggest that hip arthroscopy alters the natural history of dysplasia; therefore, patients with dysplasia should be counseled on the potential utility of PAO by appropriate hip preservation specialists.

Outcome Scores and Survivorship of Patients Undergoing Primary Hip Arthroscopy With Borderline Hip Dysplasia: A Propensity-Matched Study With Minimum 10-Year Follow-up

BACKGROUND

Patients with borderline hip dysplasia (BHD) and concomitant femoroacetabular impingement syndrome (FAIS) have demonstrated similar outcomes at short- and midterm follow-up compared with equivalent patients without dysplasia. However, comparisons between these groups at long-term follow-up have yet to be investigated.

PURPOSE

To compare long-term clinical outcomes between patients with BHD undergoing primary hip arthroscopy for FAIS versus matched control patients without BHD.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

A retrospective cohort study was conducted on patients with BHD (lateral center-edge angle, 18°-25°) who underwent hip arthroscopy for FAIS between January 2012 and February 2013. Patients were propensity matched in a 1:3 ratio by age, sex, and body mass index to control patients without BHD who underwent primary hip arthroscopy. Groups were compared in terms of patient-reported outcomes (PROs) preoperatively and at 10 years postoperatively, including the Hip Outcome Score Activities of Daily Living subscale (HOS-ADL) and Sports subscale (HOS-SS), modified Harris Hip Score, 12-item International Hip Outcome Tool, visual analog scale (VAS) for pain and satisfaction. Achievement rates for minimal clinically important difference (MCID) and Patient Acceptable Symptom State (PASS) were compared between groups. Kaplan-Meier survivorship curves were assessed between groups.

RESULTS

At a mean follow-up of 10.3 ± 0.3 years, 28 patients with BHD (20 women; age, 30.8 ± 10.8 years) were matched to 84 controls who underwent primary hip arthroscopy. Both groups significantly improved from preoperative assessment in all PRO measures at 10 years (P < .001 for all). PRO scores were similar between groups, aside from HOS-SS (BHD, 62.9 ± 31.9 vs controls, 80.1 ± 26.0; P = .030). Rates of MCID achievement were similar between groups for all PROs (HOS-ADL: BHD, 76.2% vs controls, 67.9%, P = .580; HOS-SS: BHD, 63.2% vs controls, 69.4%, P = .773; modified Harris Hip Score: BHD, 76.5% vs controls, 67.9%, P = .561; VAS pain: BHD, 75.0% vs controls, 91.7%, P = .110). Rates of PASS achievement were significantly lower in the BHD group for HOS-ADL (BHD, 39.1% vs controls, 77.4%; P = .002), HOS-SS (BHD, 45.5% vs controls, 84.7%; P = .001), and VAS pain (BHD, 50.0% vs controls, 78.5%; P = .015). No significant difference was found in the rate of subsequent reoperation on the index hip between groups. Kaplan-Meier survival analysis demonstrated comparable survivorship at long-term follow-up (P = .645).

CONCLUSION

After primary hip arthroscopy, patients with BHD in the setting of FAIS had significantly improved PRO scores at 10-year follow-up, comparable with propensity-matched controls without BHD. Rates of MCID achievement were similar between groups, although patients with BHD had lower rates of PASS achievement. Patients with BHD had similar long-term hip arthroscopy survivorship compared with controls, with no significant difference in rates of revision hip arthroscopy or conversion to total hip arthroplasty.

Primary and Revision Hip Arthroscopy in Borderline Hip Dysplasia Shows Comparable Outcomes at a Minimum 5-Year Follow-Up

PURPOSE

To compare patient-reported outcomes (PROs), achievement of clinically significant outcomes, and reoperation-free survivorship between primary and revision hip arthroscopy (HA) for femoroacetabular impingement syndrome (FAIS) in propensity-matched borderline hip dysplasia (BHD) patients at a minimum 5-year follow-up.

METHODS

Patients with BHD, characterized by a lateral center-edge angle 18° to 25°, who underwent HA for FAIS with capsular repair by a single surgeon between January 2012 and June 2018 with a minimum 5-year follow-up were identified. Cases of revision HA were propensity-matched 1:2 to cases of primary HA, controlling for age, sex, and body mass index. A 1:2 ratio was chosen to maximize the number of included patients. Collected PROs included Hip Outcome Score-Activities of Daily Living and Sport Subscales, International Hip Outcome Score 12, modified Harris Hip Score, and Visual Analog Scale for Pain. Achievement of minimal clinically important difference, patient acceptable symptom state, and substantial clinical benefit for any measured PRO was compared between groups along with reoperation-free survivorship using Kaplan-Meier analysis.

RESULTS

Thirty-six revision HA hips (34 patients) were propensity-matched to 72 primary HA hips (70 patients). The groups were similar in age (31.5 ± 10.3 years vs 30.5 ± 11.2, P = .669), sex (69.4% female vs 70.8%, P = .656), and body mass index (25.7 ± 4.0 vs 25.5 ± 3.7, P = .849). The revision group showed a greater prevalence of prolonged preoperative pain (50.0% vs 27.8%, P = .032) compared with the primary group. A significant improvement in all PROs was observed for both groups with comparable PROs preoperatively and at the 5-year follow-up between groups (P ≥ .086). The revision and primary groups showed comparable minimal clinically important difference (95.0% vs 95.7%, P ≥ .999), patient acceptable symptom state (80.0% vs 83.6%, P = .757), and substantial clinical benefit (62.5% vs 70.7%, P = .603) achievement for any PRO. Comparable reoperation-free survivorship was observed (P = .151).

CONCLUSIONS

Propensity-matched patients with BHD undergoing primary and revision hip arthroscopy for FAIS achieved similar minimum 5-year PROs, clinically significant outcomes, and reoperation-free survivorship.

LEVEL OF EVIDENCE

Level III, retrospective comparative case series.

Outcomes of Flexibility Sport Athletes With Borderline Hip Dysplasia After Hip Arthroscopy for Femoroacetabular Impingement Syndrome: A Propensity-Matched Analysis at Minimum 2-Year Follow-up

BACKGROUND

Hip arthroscopy has proved successful in treating femoroacetabular impingement syndrome (FAIS) in patients with and without borderline hip dysplasia (BHD). Despite a high prevalence of BHD in patients who participate in sports with high flexibility requirements, a paucity of literature evaluates the efficacy of hip arthroscopy in treating FAIS in flexibility sport athletes with BHD.

PURPOSE

To compare minimum 2-year patient-reported outcomes (PROs) and achievement of clinically significant outcomes in flexibility sport athletes with BHD undergoing primary hip arthroscopy for FAIS with capsular plication with results in flexibility sport athletes without dysplasia.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Data were prospectively collected for patients undergoing primary hip arthroscopy for FAIS with BHD, defined as a lateral center-edge angle of 18° to 25°, who reported participation in a sport with a high flexibility requirement, including dance, gymnastics, figure skating, yoga, cheerleading, and martial arts, according to previous literature. These patients were matched 1:2 to flexibility sport athletes without dysplasia, controlling for age, sex, and body mass index. Preoperative and minimum 2-year postoperative PROs were collected and compared between groups. Cohort-specific minimal clinically important difference and patient acceptable symptom state achievement was compared between groups.

RESULTS

In total, 52 flexibility sport athletes with BHD were matched to 104 flexibility sport athletes without BHD. Both groups showed similar sport participation (P = .874) and a similar level of competition (P = .877). Preoperative lateral center-edge angle (22.2°± 1.6° vs 31.5°± 3.9°; P < .001) and Tönnis angle (10.9°± 3.7° vs 5.8°± 4.4°; P < .001) differed between groups. Capsular plication was performed in all cases. Both groups achieved significant improvement in all PROs (P < .001) with no differences in postoperative PROs between groups (P≥ .147). High minimal clinically important difference (BHD group: 95.7%; control group: 94.8%) and patient acceptable symptom state (BHD group: 71.7%; control group: 72.2%) achievement for any PRO was observed with no differences between groups (P≥ .835).

CONCLUSION

Flexibility sport athletes with BHD achieved similar outcomes as those of flexibility sport athletes without BHD after hip arthroscopy for FAIS with capsular plication.

Borderline Hip Dysplasia Is Not Associated With Significant Differences in Hip Survivorship or Patient-Reported Outcomes Following Primary Hip Arthroscopy for Femoroacetabular Impingement Syndrome: A Propensity-Matched Cohort Study

PURPOSE

To compare hip survivorship and patient-reported outcomes after primary hip arthroscopy for femoroacetabular impingement syndrome (FAIS) in patients with versus without comorbid borderline hip dysplasia (BHD) at 2-year follow-up.

METHODS

A retrospective matched-cohort study was conducted involving patients who underwent primary hip arthroscopy for FAIS with a single surgeon from 2010 to 2019. BHD was defined as lateral center edge angle (LCEA) of 20 to 25°. Subjects with BHD were matched 1:2 to controls without BHD on age, sex, body mass index, and preoperative modified Harris Hip Score (mHHS). Alpha angle, LCEA, Tönnis angle, and acetabular retroversion signs were measured on preoperative and/or postoperative hip radiographs. Patient-reported outcomes were assessed using the mHHS and the Non-Arthritic Hip Score. Hip survivorship, outcome scores, and achievement of the minimum clinically important difference were compared between groups using the Mann-Whitney U test or Fisher exact test, as appropriate. P values <.05 were considered significant.

RESULTS

Thirty-one BHD subjects (mean age 36.8 years, 71.0% female) and 62 controls (mean age 38.0 years, 71.0% female) were included. There were no significant intergroup differences in demographics or preoperative radiographic measurements besides LCEA and Tönnis angle (all P > .05). Intraoperatively, subjects with BHD were found to have significantly shorter labral tears (mean 2.6 vs 2.8 clock-face hours, P = .048), but there were no significant intergroup differences in acetabular or femoral cartilage status (all P > .05). Postoperatively, there were no significant intergroup differences in rates of revision arthroscopy (BHD 6.5% vs control 11.3%) or conversion to total hip arthroplasty (BHD 9.7% vs control 1.6%), in 2-year improvement of the mHHS and Non-Arthritic Hip Score, or in minimum clinically important difference achievement rates (all P > .05).

CONCLUSIONS

BHD is not associated with a significant difference in hip survivorship or patient-reported outcomes following primary hip arthroscopy for FAIS.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Lateral Center-edge Angle of 18° (Bone-Edge): Threshold for Hip Arthroscopy Treatment in Patients with Borderline Developmental Dysplasia of the Hip?

OBJECTIVE

Hip arthroscopy for the treatment of symptomatic borderline developmental dysplasia of the hip (BDDH) has been controversial. The purpose of this study was to retrospectively analyze minimum 2-year outcomes of BDDH after arthroscopic surgery and explore the criteria and thresholds of the lateral center-edge angle (LCEA) in arthroscopic surgery for BDDH.

METHODS

Data were retrospectively collected from patients aged 18-50 who underwent arthroscopic surgery for BDDH and had an LCEA 18-25° between September 2016 and June 2020. The consistency of interobserver and intraobserver measurements of bone-edge LCEA was analyzed. Patients were divided into two groups based on LCEA (18-20°and 20-25°) and the results of arthroscopy compared between groups. Patient-reported outcome (PRO) scores, consisting of the modified Harris hip score (mHHS), the visual analogue scale (VAS) and the international hip outcome tool-12 (IHOT-12), the minimal clinically important difference (MCID) and patient acceptable symptom status (PASS) were calculated.

RESULTS

In 52 patients with ≥2-year follow-up, female patients accounted for 71.2% and the mean age was 30.8 ± 8.4 years (range: 18 to 49 years). There was a high level of agreement when measuring the bone-edge LCEA definition of BDDH (Kappa = 0.921). Interobserver repeatability (ICC = 0.909, 95%CI: 0.847-0.947) and intraobserver repeatability (ICC = 0.944, 95%CI: 0.905-0.968) were excellent for bone-edge LCEA measurements. In addition to LCEA and Tönnis angle, there were no significant differences in α angle, neck stem angle, femoral anteversion angle, medial joint space, Tönnis grade of osteoarthritis, acetabular retroversion (8 sign), Cam deformity and anterior inferior iliac spine (AIIS) morphology between the two groups (p > 0.05). Intraoperative findings and procedures showed no statistical difference between groups (p > 0.05). The mean follow-up time was 44.4 ± 11.0 months (range: 25 to 64 months). Postoperative VAS, mHHS and IHOT-12 scores in the LCEA 18-20° group and the LCEA 20-25° group were significantly improved compared with those before surgery, and there was no statistically significant difference in the percentage of MCID and PASS (mHHS and iHOT-12) between the groups (p > 0.05).

CONCLUSION

Patients in the LCEA 18-20° group and the LCEA 20-25° group achieved favorable outcomes after arthroscopic surgery. LCEA 18° (bone-edge) should be the threshold for hip arthroscopic surgery in BDDH patients without obvious hip instability.

Arthroscopy Confers Favorable Clinical Outcomes in Asian Patients with Borderline Developmental Dysplasia of the Hip

OBJECTIVE

Hip arthroscopy has recently appeared as a successful therapy in treating borderline developmental dysplasia of the hip (BDDH). This study aimed to describe the minimal 2-year follow-up after hip arthroscopy for patients with BDDH in the Asian population and use the combination of lateral center edge angle (LCEA) and alpha angles to detect the appearance of impingement in the BDDH population.

METHODS

This retrospective investigation was conducted utilizing information from arthroscopically treated BDDH patients in 2018 and 2019. The following patient-reported outcomes were reported: modified Harris Hip Score, Hip Outcome Score-Activities of Daily Living, International Hip Outcome Tool 12-component form, and Visual Analog Scale. We also considered the clinical data regarding radiological measurements, intraoperative findings, interventions, complications, and subsequent surgical revisions, in the analysis of combination angles in detecting the occurrence of impingement. Patients with asymptomatic contralateral hips from traumatic hip injury (pelvic fracture) served as the control group. A 2:1 propensity score matching was based on age, sex, and BMI. A receiver operating characteristic curve (ROC) was used to identify the thresholds of combination angles and their accuracies.

RESULTS

A total of 77 hips met the inclusion and exclusion requirements. After the follow-up period, most patients showed a considerable improvement in patient-reported outcomes compared to their preoperative values (P < 0.001 for all). The overall rate of complications was 5.2%, whereas the rate of revisions was 3.9%. Increasing preoperative alpha angle age was significantly positively correlated with improving patient-reported outcomes. The combined angle cut-off was determined to be 80.5° (AUC, 0.858; 95% CI: 0.757-0.938; sensitivity (SE), 98.1%; specificity (SP), 74.1%; P < 0.001) for the occurrence of impingement in BDDH population.

CONCLUSION

Good patient-reported outcomes and low revision rates can be expected in the BDDH population with careful selection of patients in Asian populations. A combination angle >80.5° could be a reliable predictive factor of impingement in BDDH populations.

Borderline Dysplastic Hips Undergoing Hip Arthroscopy Achieve Equivalent Patient Reported Outcomes When Compared With Hips With Normal Acetabular Coverage: A Systematic Review and Meta-Analysis

PURPOSE

To systematically review and meta-analyze studies reporting lateral center edge angle as it relates to patient-reported outcome (PRO) measures and clinically notable outcome assessments for patients undergoing hip arthroscopy for femoroacetabular impingement syndrome or labral pathology with borderline dysplastic hips (BDH).

METHODS

PubMed, EMBASE, and the Web of Science Core Collection databases were queried for articles evaluating lateral center edge angle as a predictor of PRO after hip arthroscopy. Articles were eligible for meta-analysis if they compared PROs measures between patients with normal acetabular coverage and borderline dysplasia and were at least level III evidence. Continuous random-effects models with standardized mean differences were used to compare postoperative Hip Outcome Score-Activities of Daily Living and sports subscales, modified Harris Hip Score, international Hip Outcome Tool scores, Satisfaction, and Visual Analog Scale Pain scores between normal coverage and borderline dysplastic groups.

RESULTS

Overall, 989 hips undergoing arthroscopy from six investigations were included in this meta-analysis, including 315 borderline dysplastic subjects (mean age 27.5 years) and 674 subjects with normal coverage (mean age 26.9 years). Borderline dysplastic and normal coverage cohorts were followed for an average of 37.0 and 36.8 months, respectively. Postoperative PRO measures (Hip Outcome Score-Activities of Daily Living, Hip Outcome Score-Sports Subscale, modified Harris Hip Score, international Hip Outcome Tool-12, Satisfaction, and Visual Analog Scale Pain) collected approximately three years after hip arthroscopy were not markedly different between subjects with BDH when compared with patients with normal coverage.

CONCLUSIONS

In a meta-analysis of the available literature, patients with BDH are able to equally reach statistically similar clinical outcomes after isolated hip arthroscopy as compared with control subjects without dysplasia at short-term follow-up. A BDH should not be considered a contraindication to hip arthroscopy when optimal PRO achievement is the goal.

LEVEL OF EVIDENCE

Level III, Systematic Review and Meta-Analysis.

High Survivorship and Comparable Patient-Reported Outcomes at a Minimum 5 Years After Hip Arthroscopic Surgery in Patients With Femoroacetabular Impingement, With and Without Lateral Rim Dysplasia

BACKGROUND

Femoroacetabular impingement (FAI) in patients with dysplasia presents a unique challenge to surgeons. Short-term outcomes are conflicting, while longer term follow-up data are only emerging.

PURPOSE

To quantify midterm (minimum 5-year follow-up) outcomes after the arthroscopic correction of FAI in the presence of lateral rim dysplasia compared with a matched control group with FAI with normal acetabular coverage.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Prospective outcome data, collected in a consecutive series of patients undergoing arthroscopic FAI correction with lateral rim dysplasia (lateral center-edge angle [LCEA] of 13°-25°), were reviewed (N = 75 cases). An age- and sex-matched control group of 120 cases was also formed (LCEA >25°). Survivorship was defined as the avoidance of total hip replacement and assessed using a Kaplan-Meier curve with the log-rank test. Survival rates and patient-reported outcome measure (PROM) scores (modified Harris Hip Score [mHHS], University of California, Los Angeles [UCLA], 36-Item Short Form Health Survey [SF-36], and Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC] preoperatively and at 5 years postoperatively) were compared between the groups. The proportion of patients across groups achieving the minimal clinically important difference (MCID) was compared for each PROM. The dysplasia group was also analyzed independently to identify any factors that may indicate a less favorable outcome using regression analysis. The group was divided into 2 subgroups: borderline dysplasia (LCEA of 20°-25°) and severe dysplasia (LCEA <20°).

RESULTS

The survival rate in the dysplasia group was 97%. There was no statistical difference with respect to survival rates or any PROM scores (P > .05 for all) between the groups. There were similar rates of achieving the MCID between the groups for the mHHS, UCLA, and WOMAC. The FAI control group had a higher rate of achieving the MCID for the SF-36 (P = .012; effect size = 0.274 [small]). Subgroup analysis indicated a lower survival rate (78% vs 100%, respectively; P < .001) in female cases in the dysplasia group (n = 9) compared with male cases in the dysplasia group (n = 66). The UCLA score in female cases in the dysplasia group at 5 years was statistically lower compared with that in male cases in the dysplasia group (6 vs 10, respectively; P = .003; effect size = 0.378 [medium]), but no other outcome revealed any differences between the sexes. There were also no variables identified on regression analysis that accurately predicted a poorer outcome in the dysplasia group. When stratified by severity, there was no difference in survivorship or outcomes between those with severe dysplasia (LCEA <20°; n = 11) and those with borderline dysplasia (LCEA of 20°-25°; n = 64).

CONCLUSION

An arthroscopic intervention was a successful treatment option for FAI in the presence of lateral rim dysplasia at midterm follow-up. Irrespective of the severity of dysplasia, patients can expect similar improvements to those in patients with normal femoral head coverage.

Patients With Unhealed or Partially Healed Anterior Capsules After Hip Arthroscopy for Borderline Developmental Dysplasia of the Hips Have Inferior Patient-Reported Outcome Measures

PURPOSE

To evaluate the changes in anterior hip capsular thickness on pre- and postoperative magnetic resonance imaging (MRI) and their associated clinical outcomes in patients with borderline developmental dysplasia of the hip (BDDH).

METHODS

A minimum 2-year follow-up retrospective analysis was performed using data from symptomatic patients with BDDH who underwent hip arthroscopy with routine capsular closure between 2018 and 2020. An available postoperative hip MRI was a prerequisite for study inclusion. Capsular thickness at the capsulotomy zone was measured on MRI. An analysis of the correlations between anterior capsular thickness differences and demographic factors (including age, sex, body mass index, laterality, preoperative alpha angle and lateral center-edge angle, cartilage lesion grade, follow-up time, and capsule management) was performed. Patients with unhealed or partially healed capsules (study group) were propensity-score matched 1:1 to patients with completely healed capsules based on age, sex, body mass index, and follow-up time. Comparisons and analyses of the following parameters were completed for both groups: patient-reported outcomes (Hip Outcome Score-Activities of Daily Living [HOS-ADL], Hip Outcome Score-Sports-Specific Subscale [HOS-SSS], International Hip Outcome Tool 12-component form [iHOT-12], and modified Harris Hip Score), visual analog scale scores, radiographic measures, performed procedures, and complications.

RESULTS

Data were compiled for 59 patients' hips after patient selection. The majority of the repaired hip capsules remained closed (93.2%) at a minimum 2-year follow-up. Propensity-score matching was applied to distribute 25 subjects in the study group and 25 in the control group. The anterior capsule was significantly thinner postoperation in the study group (3.0 ± 1.2 mm vs 4.1 ± 0.6 mm; P < .001). Compared with the control group, patients in the study group had significantly inferior postoperative HOS-ADL (75.1 vs 83.5, P = .007), HOS-SSS (64.5 vs 77.1, P = .005), and iHOT-12 scores (56.1 vs 70.2, P = .006). In addition, patients in the study group were significantly less likely to achieve the minimum clinically important difference for the HOS-ADL score (52% vs 80%, P = .037) score and patient acceptable symptomatic state for the HOS-ADL score (32% vs 60%, P = .047).

CONCLUSIONS

The majority of the repaired hip capsules in patients with BDDH remained closed but not all capsules completely healed at a minimum 2-year follow-up. Patients with an unhealed or partially healed capsule had inferior HOS-ADL, HOS-SSS, and iHOT-12 scores and were less likely to achieve the minimum clinically important difference and patient acceptable symptomatic state for the HOS-ADL score.

LEVEL OF EVIDENCE

III, retrospective comparative prognostic study.

Hip Arthroscopy for Femoroacetabular Impingement Syndrome Shows Good Outcomes and Low Revision Rates, With Young Age and Low Postoperative Pain Score Predicting Excellent 5-Year Outcomes

PURPOSE

To evaluate the clinical outcomes of hip arthroscopy for femoroacetabular impingement syndrome (FAIS) and their predictors at a minimum 5 years' follow-up.

METHODS

We retrospectively analyzed patients with FAIS after first-time unilateral hip arthroscopy between January 2010 and July 2016. Patient-reported outcomes (PROs) included the validated modified Harries Hip Score (mHHS) and Visual Analog Scale for Pain (Pain VAS). We included patients with Tönnis grade 0 or 1 and reported PROs, and excluded patients with previous hip diseases or bilateral symptoms. Bivariate and multivariate analyses were used for data analysis.

RESULTS

We included 159 patients with a mean follow-up of 6.4 years, aged 36.18 ± 8.61 years, 41.5% female, and a mean body mass index of 23.61 ± 3.45. The mean postoperative mHHS was 88.82 ± 11.60, and the mean Pain VAS was 1.93 ± 1.89, significantly better than before surgery (P < .001). Postoperative alpha angle (P = .003) and lateral center edge angle (P < .001) were significantly decreased. Most patients (83.7%) achieved clinically important improvement based on patient-acceptable symptom state and minimal clinically important difference (MCID). The overall revision surgery rate was 2.5%. There were no conversions to total hip arthroplasty. Bivariate analysis indicated that age (P < .001), preoperative mHHS (P = .002), and postoperative Pain VAS (P <.001) correlated with postoperative mHHS at a minimum 5 years' follow-up. Multivariate regression analysis of MCID showed that age (P <.001), preoperative PROs (P < .01 for both), and postoperative Pain VAS (P < .001) were significant outcome predictors.

CONCLUSION

Patients with FAIS after first-time unilateral hip arthroscopy showed significant improvement in PROs at mid-term follow-up, with a low revision surgery rate. Young patients and those with low postoperative Pain VAS showed excellent outcomes at a minimum 5 years' follow-up.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

The anterior hip capsule is thinner in dysplastic hips: a study comparing different young adult hip patients

PURPOSE

To investigate the thickness and intra-substance change of anterior capsule of the hip joint, and compare the difference of the capsular features in patients with different statuses of hip stability.

METHODS

A retrospective study was performed to review a hip preservation database. Using the lateral center edge angle(LCEA), patients with borderline dysplasia of the hip (BDH) of 20° ≤ LCEA ≤ 25°, femoracetabular impingement(FAI) with LCEA > 30° and dysplasia of the hip (DH) of LCEA < 20° were enrolled and stratified into different treatment groups. The patients' imaging was reviewed by two experienced musculoskeletal radiologists who were blinded to clinical outcomes. Thickness and intra-substance change of the anterior hip capsule was measured on the sagittal oblique sequences of MRI. A surgeon measured the thickness of the anterior hip capsule during arthroscopy. The capsular thickness and intra-substance change were compared among different groups.

RESULTS

Thirty patients (17 women and 13 men) enrolled in each group (FAI, BDH, and DH) matched by sex and ages were evaluated. There were no significant differences in terms of age, sex, BMI, Alpha angle, and Tönnis grade among all three groups. The mean thickness of the anterior capsule in the DH group was 3.2 ± 0.5 mm, which was significantly thinner than that in the BDH and FAI groups (4.5 ± 0.8 mm and 4.7 ± 0.6 mm), and there was no significant difference in capsular thickness between the BDH and FAI groups. The Median of anterior capsule thickness via arthroscopic measuring was 6 mm and 7 mm in the BDH and FAI groups respectively, which has no statistical difference. The intra-substance change of the anterior capsule shows a significant difference among the three groups, and a higher incidence of delamination of the capsule was found in DH groups (p < 0.001).

CONCLUSIONS

Patients with hip dysplasia have a significantly reduced capsular thickness on MRI and delaminated anterior joint capsule, which could be a sequence of instability. The clinical relevance of this study is that capsular thickness and intra-substance changes of the anterior capsule vary which could alter capsular management strategies.

LEVEL OF EVIDENCE

Level III of evidence, DIAGNOSTIC STUDIES, No consistently applied reference standard.

Criteria for Return to Play After Hip Arthroscopy in the Treatment of Femoroacetabular Impingement: A Systematic Review

BACKGROUND

Femoroacetabular impingement (FAI) is a common pathology in athletes that often requires operative management in the form of hip arthroscopy.

PURPOSE

To systematically review the rates and level of return to play (RTP) and the criteria used for RTP after hip arthroscopy for FAI in athletes.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A systematic review of the literature, based on the PRISMA guidelines, was performed using PubMed, Embase, and Scopus databases. Studies reporting outcomes after the use of hip arthroscopy for FAI were included. Outcomes analyzed were RTP rate, RTP level, and criteria used for RTP. Statistical analysis was performed using SPSS software.

RESULTS

Our review found 130 studies, which included 14,069 patients (14,517 hips) and had a mean methodological quality of evidence (MQOE) of 40.4 (range, 5-67). The majority of patients were female (53.7%), the mean patient age was 30.4 years (range, 15-47 years), and the mean follow-up was 29.7 months (range, 6-75 months). A total of 81 studies reported RTP rates, with an overall RTP rate of 85.4% over a mean period of 6.6 months. Additionally, 49 studies reported the rate of RTP at preinjury level as 72.6%. Specific RTP criteria were reported in 97 studies (77.2%), with time being the most commonly reported item, which was reported in 80 studies (69.2%). A total of 45 studies (57.9%) advised RTP at 3 to 6 months after hip arthroscopy.

CONCLUSION

The overall rate of reported RTP was high after hip arthroscopy for FAI. However, more than one-fourth of athletes who returned to sports did not return at their preinjury level. Development of validated rehabilitation criteria for safe return to sports after hip arthroscopy for FAI could potentially improve clinical outcomes while also increasing rates of RTP at preinjury levels.

Younger Age, Capsular Repair, and Larger Preoperative Alpha Angles Are Associated With Earlier Achievement of Clinically Meaningful Improvement After Hip Arthroscopy for Femoroacetabular Impingement Syndrome

PURPOSE

The purpose of the study was to analyze demographic, radiographic, and intraoperative factors that influence the time to achieve the minimal clinically important difference (MCID) and maximum outcome improvement satisfaction threshold (MOIT) after primary hip arthroscopy for femoroacetabular impingement syndrome (FAIS) and labral tear.

METHODS

Included patients had undergone hip arthroscopy with labral repair or reconstruction for FAIS with labral tear between February 2008 and October 2018. Patients were excluded if they had a prior ipsilateral hip surgery, prior hip conditions, a Tonnis grade > 1, or were unwilling to participate. Multiple demographic, radiographic, and intraoperative variables were collected. The modified Harris Hip Score (mHHS) and Non-Arthritic Hip Score (NAHS) were collected before surgery and at 3 months, 1 year, and 2 years after surgery. The MCID and MOIT for the mHHS and NAHS were either calculated or determined through previously published values. A time-to-event analysis was performed to determine variables predictive of early or delayed achievement of MCID or MOIT. Early achievement was defined as achieving MCID or MOIT at the 3-month timepoint.

RESULTS

Six hundred thirty-two hips (632 patients) were included. Of those that achieved MCID and MOIT, 428 (73.0%) and 414 (73.0%) patients achieved MCID and 253 (47.9%) and 264 (52.5%) patients achieved MOIT by 3 months after surgery for mHHS and NAHS, respectively. Younger age, capsular repair, and increasing alpha angle were associated with earlier achievement for either MCID or MOIT. Increasing age, worker's compensation claims, and higher baseline patient-reported outcome measure scores were associated with delayed achievement for either MCID or MOIT.

CONCLUSIONS

Most of the patients who achieved MCID and MOIT for mHHS and NAHS did so by 3 months after surgery. Younger age, capsular repair, and increasing alpha angle were associated with earlier achievement of MCID and MOIT after hip arthroscopy.

LEVEL OF EVIDENCE

Level IV, case series.

Arthroscopic Treatment of Mild/Borderline Hip Dysplasia with Concomitant Femoroacetabular Impingement-Literature Review

Purpose of Review

This literature review aims to survey the current knowledge about the management FAI in the setting of borderline hip dysplasia.

Recent Findings

With better understanding, hip arthroscopy has recently been advocated for treating mild or borderline hip dysplasia (BDH) with concomitant femoroacetabular impingement (FAI) despite early studies that condemned its use. Recent outcome data have demonstrated that hip arthroscopy is a viable option in BDH, with and without FAI, and has been gaining wider acceptance. Hip arthroscopy can address the concomitant soft tissue and bony intra-articular pathologies and obviate the necessity for other surgeries. Moreover, hip arthroscopy may be used as an adjuvant treatment to other procedures such as a periacetabular osteotomy (PAO).

Summary

Hip arthroscopy for BDH is an evolving procedure with promising short- and mid-term outcomes. The combination of BDH and FAI is becoming recognized as a problem in its own right, requiring dedicated treatment.

Patients With a High Femoroepiphyseal Roof With Concomitant Borderline Hip Dysplasia and Femoroacetabular Impingement Syndrome Do Not Demonstrate Inferior Outcomes Following Arthroscopic Hip Surgery

PURPOSE

The purpose of this study was to compare outcomes after hip arthroscopy for femoroacetabular impingement syndrome (FAIS) in patients with borderline hip dysplasia and hip instability defined radiographically using the femoroepiphyseal acetabular roof (FEAR) index and in patients without radiographic evidence of hip instability.

METHODS

Data from consecutive patients with borderline hip dysplasia (lateral center edge angle between 18˚-25˚) who underwent primary hip arthroscopy between April 2012 and June 2017 for the treatment of FAIS were analyzed. Baseline demographic data, radiographic parameters, preoperative, and 2-year postoperative patient-reported outcome measures were collected. The FEAR index was measured by 3 different observers. Patients with an average FEAR index ≥2˚ were categorized as having radiographic evidence of instability as previously published. The analysis was powered to detect a minimal clinically important difference (MCID) for each outcome score. Statistical analysis was performed as appropriate to compare patients with FEAR index ≥2 and <2°.

RESULTS

A total of 140 patients met the inclusion criteria. The average age and body mass index of included patients was 31.7 ± 13.2 (P < .325) years and 25.1 ± 5.6 kg/m² (P < .862). There were no statistically significant demographic differences between the groups. Nineteen (13.0%) patients were found to have a FEAR index of over 2˚. The FEAR index <2° and FEAR index ≥2° groups had a mean preoperative FEAR index (standard deviation, range) of -7.0 (5.2, -26.8 to 1.9) and 4.8 (2.5, 2.0-11.8), respectively. The interrater intraclass correlation coefficient was 0.96. Postoperative patient-reported outcomes and rates of MCID and patient-acceptable symptomatic state achievement were not statistically different between the radiographically stable and unstable groups. (p>0.05 for all).

CONCLUSION

Patients with borderline hip dysplasia and radiographic evidence of hip instability, as measured by the FEAR index (≥2°), achieve similar improvement in 2-year outcomes compared to those with radiographically stable hips after arthroscopic treatment of FAIS.

CLINICAL RELEVANCE

Retrospective Level III cohort study.

Increased Combined Anteversion Is an Independent Predictor of Ischiofemoral Impingement in the Setting of Borderline Dysplasia With Coxa Profunda

PURPOSE

To investigate the differences in radiologic parameters between borderline dysplasia hips (BDDH) +/- coxa profunda and normal hips and to evaluate the correlations between these parameters and the prevalence of ischiofemoral impingement (IFI) in borderline dysplasia.

METHODS

The imaging of patients with BDDH (18° ≤ lateral center edge angle <25°) treated in our hospital from January 2018 to December 2019 was retrospective reviewed. These patients were divided into BDDH with coxa profunda (acetabular fossa touches the ilioischial line, pBDDH) and without coxa profunda (nBDDH) groups. The groups were compared with a control group with normal acetabular coverage. Neck-shaft angle, femoral offset, acetabular versions, acetabular coverage, ischial angle, femoral neck version, and combined anteversion were reviewed and analyzed using computed tomography imaging using one-way analysis of variance.

RESULTS

There were 43 patients (36 female/7 male, 26.13 ± 4.96 years) in the pBDDH group, 22 patients (17 female/5 male, 28.60 ± 5.89 years) in the nBDDH group, and 23 patients (14 female/9 male, 27.67 ± 5.98 years) in the control group. The pBDDH group had increased femoral version, ischial angle, acetabular versions, and decreased ischiofemoral space (IFS)/quadratus femoris space (QFS) than the other 2 groups. The IFS/QFS correlated with neck-shaft angle, femoral offset, femoral neck version, acetabular versions, ischial angle, femoral neck-lesser trochanter angle, posterior acetabular coverage, and combined anteversion in patients with BDDH. Combined anteversion at the 3-o'clock level was an independent predictor of a decreased IFS (beta = -0.348, P = .007) and QFS (beta = -0.255, P = .01, R² = .550). Binary logistic regression demonstrated that patients with BDDH with large combined anteversion at the 3-o'clock level had a greater prevalence of IFI (odds ratio 1.148; P = .001, R² = .505).

CONCLUSIONS

In patients with borderline dysplasia, the QFS/IFS significantly correlated with combined anteversion at the 3-o'clock level on clock face of acetabulum. BDDH with coxa profunda might have a greater prevalence of IFI because of large combined anteversion.

LEVEL OF EVIDENCE

III, retrospective comparative observation study.

Ten-Year Outcomes After Hip Arthroscopy in Patients With Femoroacetabular Impingement and Borderline Dysplasia

BACKGROUND

The role of hip arthroscopy in the treatment of patients with borderline hip dysplasia is controversial and evolving.

PURPOSE

To evaluate outcomes at a minimum 10-year follow-up in patients who underwent hip arthroscopy for femoroacetabular impingement in a hip with borderline dysplasia.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

All hips that underwent labral repair between June 2006 and March 2009 for femoroacetabular impingement with borderline dysplasia were included if they had a lateral center-edge angle of 20° to 25°, had primary hip arthroscopy for the diagnosis of femoroacetabular impingement, and were aged 18 to 70 years. Patients were excluded if they had previous hip surgery, avascular necrosis, or fracture. Kaplan-Meier survivorship was performed, with survivorship defined as avoidance of conversion to total hip arthroplasty (THA).

RESULTS

A total of 45 patients met the inclusion criteria, and 38 were contacted at a minimum 10 years postoperatively (84%; mean ± SD, 12 ± 1.3 years). There were 23 women and 15 men with an average age of 41 ± 9.6 years (range, 25-69). Twenty patients were ≥40 years of age. In this patient cohort, survivorship was 87% at 5 years and 79% at 10 years for conversion to THA. Of the 38 patients included, 9 were converted to THA (24%), and 3 required revision hip arthroscopy (7%). Patient age, Tönnis grade, microfracture of cartilage lesions, and Tönnis angle >15° were associated with conversion to THA. No statistically significant differences were found between those who underwent conversion to THA and those who did not regarding lateral center-edge angle, Sharp angle, or alpha angle. Significant improvements were seen at follow-up of 12 years (range, 10-13) for the modified Harris Hip Score (58 to 83; P = .002), Hip Outcome Score-Activities of Daily Living (70 to 87; P = .003), Hip Outcome Score-Sport (47 to 76; P = .004), and Western Ontario and McMaster Universities Osteoarthritis Index (31 to 10; P = .001). At follow-up, >80% maintained the minimal clinically important difference for the Hip Outcome Score (Activities of Daily Living and Sport) with no differences between patients aged <40 and ≥40 years.

CONCLUSION

Risk factors for conversion to THA after hip arthroscopy in the borderline dysplastic hip included older age, higher Tönnis grades, grade 4 chondral lesions that were microfractures, and Tönnis angle >15°. In those patients who did not convert to THA, improvement in outcome measures was seen at 10 years. Careful patient selection is critical to the success of this procedure.

Return to Sport in Athletes With Borderline Hip Dysplasia After Hip Arthroscopy for Femoroacetabular Impingement Syndrome

BACKGROUND

Data on outcomes in patients with borderline hip dysplasia (BHD) who undergo hip arthroscopy remain limited, particularly in regard to return to sport (RTS).

PURPOSE

To evaluate outcomes in patients with BHD and their ability to RTS after hip arthroscopy for treatment of femoroacetabular impingement syndrome (FAIS).

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Consecutive patients with self-reported athletic activity and radiographic evidence of BHD, characterized by a lateral femoral center-edge angle (LCEA) between 18° and 25° and a Tönnis angle >10°, who underwent hip arthroscopy for FAIS between November 2014 and March 2017 were identified. Patient characteristics and clinical outcomes including the Hip Outcome Score-Activities of Daily Living (HOS-ADL), Hip Outcome Score-Sports Subscale (HOS-SS), modified Harris Hip Score (mHHS), international Hip Outcome Tool (iHOT-12), and visual analog scale (VAS) for pain and satisfaction were analyzed at minimum 2-year follow-up. In addition, all patients completed an RTS survey.

RESULTS

A total of 41 patients with a mean age and body mass index (BMI) of 29.6 ± 13.4 years and 25.3 ± 5.6, respectively, were included. Mean LCEA and Tönnis angle for the study population were 22.7°± 1.8° and 13.3°± 2.9°, respectively. A total of 31 (75.6%) patients were able to RTS after hip arthroscopy at a mean of 8.3 ± 3.2 months. A total of 14 patients (45.2%) were able to RTS at the same level of activity, 16 patients (51.6%) returned to a lower level of activity, and only 1 (3.2%) patient returned to a higher level of activity. Of the 11 high school and collegiate athletes, 10 (90.9%) were able to RTS. All patients demonstrated significant improvements in all patient-reported outcome measures (PROMs) as well as in pain scores at a mean of 26.1 ± 5.4 months after surgery. Patients who were able to RTS had a lower preoperative BMI than patients who did not RTS. Analysis of minimum 2-year PROMs demonstrated better HOS-ADL, HOS-SS, mHHS, iHOT-12, and VAS outcomes for pain in patients able to RTS versus those who did not RTS (P < .05).

CONCLUSION

Of the patients with BHD studied here, 75.6% of patients successfully returned to sport at a mean of 8.3 ± 3.2 months after hip arthroscopy for FAIS. Of the patients who successfully returned to sport, 45.2% returned at the same level, and 3.2% returned at a higher activity level.

Isolated arthroscopic treatment of intra-articular pathologies in mild hip dysplasia: a short-term case control study

PURPOSE

The aim is to compare the results of isolated hip arthroscopy in patients with borderline dysplasia with Lateral center edge angle (LCEA) between 18° and 25° with a control group of patients with normal LCEA (> 25°).

METHODS

Fifty hip arthroscopies performed in 45 patients were retrospectively evaluated. Exclusion criteria were: age > 40, hip arthritis > grade 2 according to Tonnis classification, femoral head avascular necrosis, pediatric's orthopaedics conditions and true dysplasia with LCEA < 18°.Two groups were identified: group A with 15 hips with LCEA between 25° and 18° and Group control B made of 35 hips with LCEA > 25°.

RESULTS

The groups were homogeneous for demography and pre-operative WOMAC and HOOS. Osteoplasty for CAM were performed in 100% of patients in both groups, only in 12 hips (34.4%) in group B we had both femoral and acetabular osteoplasty. Labral repair was performed in 86% of patients in group A, in 60% of patients in group B, capsular plication in 93% of group A, in 5% of case of group B. WOMAC and HOOS statically significant improved in both groups at final follow-up (24 months). No cases in both groups required conversion to total hip arthroplasty. Clinical outcomes of study group were comparable to the control group.

CONCLUSION

Even if the present small series is not conclusive, we suggest isolated arthroscopic management of patients with FAI and LCEA between 18° and 25°, but capsular plication and careful labral management are strongly recommended.

LEVEL OF EVIDENCE

Level IV.

One Bony Morphology, Two Pathologic Entities: Sex-Based Differences in Patients With Borderline Hip Dysplasia Undergoing Hip Arthroscopy

BACKGROUND

Sex-based differences have been largely uncharacterized for patients with borderline hip dysplasia (BHD) undergoing hip arthroscopy.

PURPOSE

To evaluate for sex-based differences in clinical and pathologic characteristics as well as surgical outcomes in patients with BHD undergoing hip arthroscopy.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Between January 2011 and December 2018, data were prospectively collected on all patients with BHD undergoing primary hip arthroscopy. Patients were included if they had preoperative and minimum 2-year postoperative scores for the modified Harris Hip Score (mHHS), Non-arthritic Hip Score (NAHS), and visual analog scale for pain. Patients with previous ipsilateral hip conditions or surgery, Tönnis grade >1, lateral center-edge angle <18° or >25°, or workers' compensation status were excluded. Patients were then divided by sex and propensity score matched in a 1:1 ratio for body mass index, age, and Tönnis grade. The rates of patients who achieved the minimal clinically important difference were recorded for the mHHS and NAHS. The rates of achieving the patient acceptable symptomatic state for the mHHS were calculated.

RESULTS

A total of 344 hips met the inclusion criteria, and 317 hips (92%) had adequate follow-up. Propensity score matching created cohorts of 109 male and 109 female patients. Male patients had significantly higher preoperative average alpha angles (69.79° vs 58.17°, P < .001), more often requiring a femoroplasty (97.2% vs 83.5%, P < .001), and had higher rates of complex labral tearing (50.5% vs 33.0%, P < .001). Male patients also had higher rates of grade 3 and 4 acetabular labral articular disruption (62.4% vs 19.3%, P < .001) and higher rates of grade 3 and 4 acetabular cartilage injury (59.6% vs 20.2%, P < .001) requiring a microfracture more frequently (32.1% vs 7.3%, P < .001). Female patients more typically had painful internal snapping requiring iliopsoas fractional lengthening (60.6% vs 32.1%, P < .001). Female patients also underwent capsular plication more regularly to address hip instability (79.8% vs 45.9%, P < .001). Male and female patients showed significant improvements in all outcome scores after surgery (P < .001). Female patients achieved the minimal clinically important difference for the NAHS at higher rates (85.3% vs 71.6%, P = .020).

CONCLUSION

Female and male patients with BHD who underwent hip arthroscopy achieved favorable outcomes but had notably dissimilar pathology. Hence, although they share similar acetabular bony morphology, male and female patients with BHD may represent 2 very different pathologic entities.

Patients Require Less Time to Complete Preoperative Patient-Reported Outcomes Measurement Information System (PROMIS) Than Legacy Patient-Reported Outcome Measures

Purpose

To analyze time to completion of preoperative legacy patient-reported outcomes (PROs) and more recent computer adaptive Patient-Reported Outcomes Measurement Information System (PROMIS) questionnaires in patients with symptomatic femoroacetabular impingement syndrome undergoing primary hip arthroscopy.

Methods

A retrospective analysis was conducted on patients undergoing hip arthroscopy by a single fellowship-trained hip arthroscopist. Inclusion criteria were patients undergoing primary arthroscopic hip surgery and completion of at least 1 legacy PRO or PROMIS questionnaire at the preoperative time point. Exclusion criteria were history of contralateral or ipsilateral hip surgery, non-English-speaking patients, patients who completed PROs by phone or by paper form, and patients who did not complete preoperative PROs. Legacy PROs included modified Harris Hip Score (mHHS), Hip Outcome Score (HOS), International Hip Outcome Tool (iHOT-12), and Hip Pain Visual Analog Scale (VAS-Pain). PROMIS PROs included Physical Function (PROMIS-PF), Pain Interference (PROMIS-PI), and Depression (PROMIS-D). Only preoperative PROs were included in the analysis. Completion time was calculated using the questionnaire start and stop time reported by the survey collecting software. The median and interquartile range of each PRO were reported for analysis of central tendency and statistical dispersion, respectively.

Results

A total of 1,901 patients and 269 patients were included in the legacy and PROMIS groups, respectively. The median time required for completion of each PRO in (minutes: seconds) format was as follows: mHHS (1:29), HOS (3:58), iHOT (2:11), VAS-Pain (0:32), PROMIS-PF (0:46), PROMIS-PI (0:37), and PROMIS-D (0:43). The interquartile range of the middle 50% of respondents was as follows; mHHS (0:58), HOS (2:46), iHOT (1:22), VAS-Pain (0:28), PROMIS-PI (0:19), PROMIS-D (0:29), and PROMIS-PF (0:20).

Conclusions

This study supports that preoperative PROMIS forms require less time to complete than preoperative legacy PROs and are not significantly influenced by age, race, or workers compensation status.

Level of Evidence

Level IV, case series.

Arthroscopic Treatment of Femoroacetabular Impingement in Patients With and Without Borderline Developmental Dysplasia of the Hip: A Systematic Review and Meta-analysis

Background:

Based on previous studies, it is difficult to discern whether patients who have femoroacetabular impingement (FAI) with borderline developmental dysplasia of the hip (BDDH) would benefit from arthroscopy when compared with patients without BDDH.

Purpose:

To evaluate the existing comparative literature on arthroscopic findings, procedures, patient-reported outcomes (PROs), and failures in patients who have FAI with BDDH compared with those without BDDH.

Study Design:

Systematic review; Level of evidence, 3.

Methods:

The PubMed, Embase, and Ovid databases were searched for studies published up to August 31, 2019, that reported outcomes after arthroscopy to treat patients who had FAI with BDDH. Included studies were required to have patients diagnosed with FAI and BDDH who were treated arthroscopically and compared with control patients (FAI without BDDH). Arthroscopic findings, PROs, and revision or total hip arthroplasty (THA) conversion rates were compared between groups.

Results:

Included in the review were 4 articles (933 patients). Patients who had FAI with BDDH were defined as having a lateral center-edge angle (LCEA) of either 18° to 25° or 20° to 25°; for control patients, the maximum LCEA was 40°. Across the studies, there were 224 patients who had FAI with BDDH compared with 709 control patients; the mean follow-up time ranged from 21.6 to 31.3 months among the groups. Improvements were shown across all PROs in each study. Random-effects meta-analysis indicated no statistically significant differences in postoperative PROs, the risk for revision surgery, or conversion to THA between the patients who had FAI with versus without BDDH.

Conclusion:

The results of the current review indicated that hip arthroscopy produced similar short-term outcomes between patients who had FAI with versus without BDDH.

Hip Capsular Plication With Crossed Mattress Stitch Configuration for a Revision Hip Arthroscopy in the Setting of Capsular Insufficiency

The hip capsule is an important static stabilizer of the hip joint. Perioperative capsular management during hip-preservation surgery is critical to maintain hip stability. Many biomechanical and clinical studies have demonstrated the importance of performing a comprehensive capsular closure to restore normal hip kinematics. For this reason, capsular closure or plication is now routine practice for many hip arthroscopists. The purpose of the technique is to describe a capsular plication technique using a mattress stitch configuration performed in the revision setting.

Complete Capsular Closure Provides Higher Rates of Clinically Significant Outcome Improvement and Higher Survivorship Versus Partial Closure After Hip Arthroscopy at Minimum 5-Year Follow-Up

PURPOSE

To (1) compare the rates of reaching threshold hip-specific outcome scores for achieving the minimal clinically important difference (MCID) and patient acceptable symptomatic state (PASS) in patients who underwent partial versus complete T-capsulotomy repair and (2) identify the failure rates in each group 5 years after undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAIS).

METHODS

Data from consecutive patients who underwent hip arthroscopy for FAIS performed by a single fellowship-trained surgeon from January 2011 to March 2013 were collected and analyzed. Baseline data, hip-specific outcomes, and clinical failure rates were recorded at a minimum of 5 years postoperatively. Patients with partial T-capsulotomy repair were matched 1:3 by age, body mass index, and sex to patients with complete T-capsulotomy repair. Threshold scores for achieving the MCID and PASS were calculated and compared between the 2 groups. Additionally, rates of revision and conversion to total hip arthroplasty (THA) were compared between the groups.

RESULTS

A total of 379 patients were available for analysis (39 partial and 340 complete repairs), with 100 patients included in the matching process (25 in the partial-repair group and 75 in the complete-repair group). Comparison of radiographic parameters, including the Tönnis grade, alpha angle, and lateral center-edge angle, between the 2 groups showed no statistically significant difference (P > .05 for all). Comparison of postoperative score averages between the partial- and complete-closure groups showed a significant difference in the Hip Outcome Score-Activities of Daily Living Subscale (85.4 ± 17.7 vs 94.6 ± 7.8, P < .001), Hip Outcome Score-Sports Subscale (76.6 ± 26.2 vs 89.3 ± 16.8, P = .034), modified Harris Hip Score (83.2 ± 19.7 vs 90.5 ± 11.2, P = .035), and visual analog scale pain score (24.5 ± 30.8 vs 13.4 ± 15.8, P = .035). A total of 65 complete-repair patients (95.6%) achieved the MCID for at least 1 outcome measure versus 18 patients with partial repair (78.3%) (P = .04). A total of 69 complete-repair patients (92%) achieved the PASS for at least 1 outcome measure versus 18 partial-repair patients (72%) (P = .017). Of the 39 partial-repair patients, 35.9% (n = 14) underwent revision or conversion to THA, as compared with 2.9% (n = 10) in the overall cohort.

CONCLUSIONS

At a minimum 5-year follow-up, patients with complete capsular closure after hip arthroscopy for FAIS show superior long-term outcomes and achieve higher rates of meaningful clinical success when compared with patients with partial capsular closure. Furthermore, patients with partial capsular repair undergo revision or conversion to THA at high rates.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Hip arthroscopy and T-shaped capsular plication for the treatment of borderline dysplasia: a minimum 2-year follow-up

PURPOSE

The aim of the study was to evaluate the clinical outcomes of patients treated arthroscopically for symptomatic borderline dysplasia of the hip (BHD) with a T-shaped capsular plication, with a minimum follow-up of 24 months.

METHODS

Twenty-seven patients who had undergone hip arthroscopy and T-shaped capsular plication for symptomatic BHD were included in the study. All patients were clinically evaluated prior to surgery (T₀) and at two consecutive follow-ups (T₁: 12 ± 1.2 months; T₂: 52.0 ± 23.2 months) using the visual analogue scale (VAS) pain score, the Hip Outcome Score in activities of daily living (HOS-ADL) and sport-specific subscale (HOS-SSS), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Short Form-12 in its physical (PCS) and mental component scores (MCS). We also evaluated the presence of correlations and analysed the possible differences between subgroups.

RESULTS

We found a significant difference for HOS-ADL, HOS-SSS, VAS and WOMAC with the Friedman test for repeated measures through time points (p < 0.0001), but not for MCS. All clinical scores reported a significant improvement compared to the previous time point (p < 0.05), with the exception of HOS-SSS, for which p = 0.2570 between T₁ and T₂. The body mass index was positively correlated with preoperative VAS (R = 0.42857; p = 0.0257) and negatively correlated with PCS at T₀ (R = - 0.40999; p = 0.0337) and with PCS (R = - 0.40491; p = 0.0362), MCS (R = - 0.45939; p = 0.0159) and WOMAC (R = - 0.40573; p = 0.0216) at T₂. No complications were reported in our cohort.

CONCLUSIONS

The results of the current study confirm that patients with intra-articular hip pathology and concomitant BHD (LCEA 20°-25°) can benefit from arthroscopic treatment and that T-shaped capsular plication is one of the available options. Orthopaedic surgeons specialising in hip arthroscopy should consider arthroscopy for the treatment of symptomatic BHD for stabilising and strengthening the joint. Future studies should focus on finding out which type of patients can benefit most from this procedure.

LEVEL OF EVIDENCE IV

Prospective Case Series.

Comparison Between Hip Arthroscopic Surgery and Periacetabular Osteotomy for the Treatment of Patients With Borderline Developmental Dysplasia of the Hip: A Systematic Review

Background:

The treatment for borderline developmental dysplasia of the hip (BDDH) has historically been arthroscopic surgery or periacetabular osteotomy (PAO). As orthopaedic surgery is constantly evolving, a lack of comparison of outcomes for these 2 treatment methods could potentially be stalling the progression of treatment for patients with BDDH.

Purpose:

To evaluate the existing literature on patient characteristics, procedures, clinical outcomes, and failure rates for patients with BDDH and to determine whether PAO or hip arthroscopic surgery is a better treatment method for patients with BDDH.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

Studies included were found using the following search words: “hip” and “borderline dysplasia,” “osteotomy” or “arthroscopy,” and “outcome” or “procedure.” Articles were included if they detailed participants of all sexes and ages, reported on isolated hips, and had patients diagnosed with BDDH.

Results:

A search was conducted across 3 databases, resulting in 469 articles for consideration, from which 12 total studies (10 on arthroscopic surgery and 2 on PAO) were chosen for a review. There were 6 studies that included patients with a lateral center-edge angle of 18° to 25°, while the remainder included patients with a lateral center-edge angle of 20° to 25°. All the studies reviewing arthroscopic surgery reported concomitant/accessory procedures, while the articles on the topic of PAO did not. It was determined that, whether treated using arthroscopic surgery or PAO, outcomes improved across all patient-reported outcome measures. Revision surgery was also common in both procedures.

Conclusion:

There is a lack of consensus in the literature on the best treatment option for patients with BDDH. Preoperative patient characteristics and concomitant injuries should be considered when evaluating which surgical procedure will result in the most favorable outcomes.

Hip Arthroscopy for Femoroacetabular Impingement Syndrome in Adolescents Provides Clinically Significant Outcome Benefit at Minimum 5-Year Follow-Up

PURPOSE

To report the rates of achieving clinically significant outcomes as defined by the minimal clinically important difference (MCID), patient acceptable symptomatic state (PASS), or substantial clinical benefit (SCB) in adolescent patients and the rates of clinical failure 5 years after undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAIS).

METHODS

Data from consecutive adolescent patients (defined by the American Academy of Pediatrics as age 11 to 21 years) who underwent primary hip arthroscopy with routine capsular closure for the treatment of FAIS between January 2012 and January 2015 by a single, fellowship-trained surgeon was collected. Baseline data, clinical outcomes including Hip Outcome Score (HOS)-Activities of Daily Living, HOS-Sports Subscale, modified Harris hip score, international Hip Outcome Tool, and clinical failure rates were recorded at 5 years after operative. Clinical failure was defined by revision hip arthroscopy or conversion to total hip arthroplasty. Clinically significant outcomes was defined as achieving MCID, PASS, or SCB on at least 1 hip-specific outcome measure.

RESULTS

Of the 139 eligible patients, a total of 85 (60.4%) patients (85 hips) were included in the final analysis, with an age and body mass index average of 17.6 ± 2.5 years (range 13-21) and 22.3 ± 3.1 kg/m², respectively. The majority of the patients were female (80.6%) and participated in sports (76.2%). There was statistically significant difference between preoperative and postoperative score averages across every reported outcome (P < .001). At 5 years, 88.4%, 67.6%, and 64.9% reached at least 1 threshold for achieving MCID, PASS, and SCB, respectively, whereas 89.2% achieved at least one of the meaningful outcome thresholds. Last, 2 patients (2.4%) failed clinically, with both undergoing revision (2.4%) because of continued pain. There were no conversions to total hip arthroplasty.

CONCLUSION

This study demonstrated that a large majority (89.2%) of adolescent patients undergoing primary arthroscopic treatment for symptomatic FAIS achieved meaningful clinically significant outcomes. Furthermore, only 2.4% of patients failed clinically, requiring revision hip arthroscopy because of continued pain.

LEVEL OF EVIDENCE

IV, Retrospective Case Series.

Development and Internal Validation of Supervised Machine Learning Algorithms for Predicting Clinically Significant Functional Improvement in a Mixed Population of Primary Hip Arthroscopy

PURPOSE

To (1) develop and validate a machine learning algorithm to predict clinically significant functional improvements after hip arthroscopy for femoroacetabular impingement syndrome and to (2) develop a digital application capable of providing patients with individual risk profiles to determine their propensity to gain clinically significant improvements in function.

METHODS

A retrospective review of consecutive hip arthroscopy patients who underwent cam/pincer correction, labral preservation, and capsular closure between January 2012 and 2017 from 1 large academic and 3 community hospitals operated on by a single high-volume hip arthroscopist was performed. The primary outcome was the minimal clinically important difference (MCID) for the Hip Outcome Score (HOS)-Activities of Daily Living (ADL) at 2 years postoperatively, which was calculated using a distribution-based method. A total of 21 demographic, radiographic, and patient-reported outcome measures were considered as potential covariates. An 80:20 random split was used to create training and testing sets from the patient cohort. Five supervised machine learning algorithms were developed using 3 iterations of 10-fold cross-validation on the training set and assessed by discrimination, calibration, Brier score, and decision curve analysis on an independent testing set of patients.

RESULTS

A total of 818 patients with a median (interquartile range) age of 32.0 (22.0-42.0) and 69.2% female were included, of whom 74.3% achieved the MCID for the HOS-ADL. The best-performing algorithm was the stochastic gradient boosting model (c-statistic = 0.84, calibration intercept = 0.20, calibration slope = 0.83, and Brier score = 0.13). Of the initial 21 candidate variables, the 8 most important features for predicting the MCID for the HOS-ADL included in model training were body mass index, age, preoperative HOS-ADL score, preoperative pain level, sex, Tönnis grade, symptom duration, and drug allergies. The algorithm was subsequently transformed into a digital application using local explanations to provide customized risk assessment: https://orthoapps.shinyapps.io/HPRG_ADL/.

CONCLUSIONS

The stochastic boosting gradient model conferred excellent predictive ability for propensity to gain clinically significant improvements in function after hip arthroscopy. An open-access digital application was created, which may augment shared decision-making and allow for preoperative risk stratification. External validation of this model is warranted to confirm the performance of these algorithms, as the generalizability is currently unknown.

LEVEL OF EVIDENCE

IV, Case series.

Evaluation of outcome reporting trends for femoroacetabular impingement syndrome- a systematic review

PURPOSE

The aim of this systematic review was to evaluate the trends in the literature regarding surgical treatment for femoroacetabular impingement syndrome (FAIS) and to present which patient-reported outcome-measures (PROMs) and surgical approaches are included.

METHODS

This systematic review was conducted with the PRISMA guidelines. The literature search was performed on PubMed and Embase, covering studies from 1999 to 2020. Inclusion criteria were clinical studies with surgical treatment for FAIS, the use of PROMs as evaluation tool and studies in English. Exclusion criteria were studies with patients < 18 years, cohorts with < 8 patients, studies with primarily purpose to evaluate other diagnoses than FAIS and studies with radiographs as only outcomes without using PROMs. Data extracted were author, year, surgical intervention, type of study, level of evidence, demographics of included patients, and PROMs.

RESULTS

The initial search yielded 2,559 studies, of which 196 were included. There was an increase of 2,043% in the number of studies from the first to the last five years (2004-2008)-(2016-2020). There were 135 (69%) retrospective, 55 (28%) prospective and 6 (3%) Randomized Controlled Trials. Level of evidence ranged from I-IV where Level III was most common (44%). More than half of the studies (58%) originated from USA. Arthroscopic surgery was the most common surgical treatment (85%). Mean follow-up was 27.0 months (± 17 SD), (range 1.5-120 months). Between 1-10 PROMs were included, and the modified Harris Hip Score (mHHS) was most commonly used (61%).

CONCLUSION

There has been a continuous increase in the number of published studies regarding FAIS with the majority evaluating arthroscopic surgery. The mHHS remains being the most commonly used PROM.

Large Heterogeneity Among Minimal Clinically Important Differences for Hip Arthroscopy Outcomes: A Systematic Review of Reporting Trends and Quantification Methods

PURPOSE

To perform a systematic review of reporting trends and quantification methods for the minimal clinically important difference (MCID) within the hip arthroscopy literature.

METHODS

Cochrane, PubMed, and OVID/MEDLINE databases were queried for hip arthroscopy articles that reported the MCID. Studies were classified as (1) calculating new MCID values for their specific study-population or (2) referencing previously established MCID values. Data pertaining to patient demographics, study characteristics, outcome measures, method of MCID quantification, MCID value, anchor questions, measurement error, and study from which referenced MCID values were obtained were extracted.

RESULTS

A total of 59 articles with 18,830 patients (19,867 hips) was included. A total of 19 unique outcome measures was reported. A total of 33 (n = 55.9%) studies (follow-up range 6-60 months) used previously established MCID values to assess their study population (MCID values established at a follow-up range 6-31 months). The remaining 26 studies (44.1%) performed new MCID calculations. The MCID values were inconsistent and varied widely (Hip Outcome Score-Activities of Daily Living: 5.0-15.4; Hip Outcome Score-Sports Subscale: 6-25; modified Harris hip score: 2.4-20.9). Among the 33 studies that used previously established MCID values, 10 different studies were cited as the reference. Among the remaining 26 studies that calculated a new MCID value, the most common method was 0.5 standard deviation method (n = 21, 80.8%). Only 3 of 26 (11.5%) studies reported a measurement of error in conjunction with their MCID values.

CONCLUSIONS

Inconsistencies in MCID reporting and quantification methods led to a wide range of MCID values for commonly administered outcome measures within the hip arthroscopy literature-even for the same outcome measures. The majority of studies referenced previously established MCID values with variable ranges of follow-up and applied those values to assess their specific study population at varying follow-ups.

LEVEL OF EVIDENCE

IV, systematic review.

Adolescent hip dysplasia: what are the symptoms and how to diagnose it

PURPOSE OF REVIEW

Adolescent and young adult hip dysplasia is a cause of hip pain which can lead to early hip osteoarthritis. This may result in early hip osteoarthrosis and possible total hip arthroplasty if dysplasia is not recognized and treated. Hip dysplasia in this population can be difficult to diagnose. It is important for primary care providers and pediatricians to recognize the symptoms, physical examination findings, and radiographic findings associated with adolescent hip dysplasia so that the patient can be referred to an orthopedist specializing in hip disorder. The current review includes the most up-to-date literature on the diagnosis of adolescent hip dysplasia.

RECENT FINDINGS

Recent studies have shown that most patients presenting with symptomatic hip dysplasia present with insidious onset hip pain localized to either the groin or lateral aspect of the hip in a C-shape distribution around the inguinal crease. Patients most commonly see several different providers and have pain for a long period prior to accurate diagnosis. There are myriad radiographic measurements of hip dysplasia, many of which are described below that are helpful in initial diagnosis.

SUMMARY

Adolescent and young adult hip dysplasia can be a cause of early, progressive hip osteoarthritis. Hip dysplasia is a term that represents a spectrum of disorder due to abnormal formation of the hip joint, resulting in an acetabulum that does not sufficiently cover the femoral head. The ability to recognize symptoms, physical examination findings, and radiographic evidence of adolescent hip dysplasia is critical so that the patient can be referred to the appropriate provider and receive timely treatment prior to the onset of degenerative hip disease. This article will focus mainly on the diagnosis of adolescent hip dysplasia. The standard for treatment of acetabular dysplasia in skeletally mature patients is the periacetabular osteotomy; however, nonoperative management and occasionally arthroscopic surgery can also be considered in cases of symptomatic borderline dysplasia.

Radiographic Indices Are Not Predictive of Clinical Outcomes Among 1735 Patients Indicated for Hip Arthroscopic Surgery: A Machine Learning Analysis

BACKGROUND

The relationship between the preoperative radiographic indices for femoroacetabular impingement syndrome (FAIS) and postoperative patient-reported outcome measure (PROM) scores continues to be under investigation, with inconsistent findings reported.

PURPOSE

To apply a machine learning model to determine which preoperative radiographic indices, if any, among patients indicated for the arthroscopic correction of FAIS predict whether a patient will achieve the minimal clinically important difference (MCID) for 1- and 2-year PROM scores.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 1735 consecutive patients undergoing primary hip arthroscopic surgery for FAIS were included from an institutional hip preservation registry. Patients underwent preoperative computed tomography of the hip, from which the following radiographic indices were calculated by a musculoskeletal radiologist: alpha angle, beta angle, sagittal center-edge angle, coronal center-edge angle, neck shaft angle, acetabular version angle, and femoral version angle. PROM scores were collected preoperatively, at 1 year postoperatively, and at 2 years postoperatively for the modified Harris Hip Score (mHHS), the Hip Outcome Score (HOS)-Activities of Daily Living (HOS-ADL) and -Sport Specific (HOS-SS), and the International Hip Outcome Tool (iHOT-33). Random forest models were created for each PROM at 1 and 2 years' follow-up, with each PROM's MCID used to establish clinical meaningfulness. Data inputted into the models included ethnicity, laterality, sex, age, body mass index, and radiographic indices. Comprehensive and separate models were built specifically to assess the association of the alpha angle, femoral version angle, coronal center-edge angle, McKibbin index, and hip impingement index with respect to each PROM.

RESULTS

As evidenced by poor area under the curves and P values >.05 for each model created, no combination of radiographic indices or isolated index (alpha angle, coronal center-edge angle, femoral version angle, McKibbin index, hip impingement index) was a significant predictor of a clinically meaningful improvement in scores on the mHHS, HOS-ADL, HOS-SS, or iHOT-33. The mean difference between 1- and 2-year PROM scores compared with preoperative values exceeded the respective MCIDs for the cohort.

CONCLUSION

In patients appropriately indicated for FAIS corrective surgery, clinical improvements can be achieved, regardless of preoperative radiographic indices, such as the femoral version angle, coronal center-edge angle, and alpha angle. No specific radiographic parameter or combination of indices was found to be predictive of reaching the MCID for any of the 4 studied hip-specific PROMs at either 1 or 2 years' follow-up.

Arthroscopic management with labral preservation, femoral osteoplasty, and capsular plication in patients with borderline hip dysplasia. Results of a matched-cohort study at minimum two year follow-up

PURPOSE

The purpose of this study was to assess intra-operative findings, surgical procedures, and outcomes in a cohort of patients with borderline hip dysplasia treated with arthroscopic labral repair, femoral osteoplasty, and capsular plication, and compare these outcomes with those of a rigorously matched control group without dysplasia.

METHODS

Data were prospectively collected and retrospectively reviewed for patients with a lateral center-edge angle between 20 and 24° who underwent hip arthroscopy surgery between 2014 and 2018. Labral, chondral status, psoas impingement, ligamentum teres, and cam morphology were evaluated. Patient-reported outcomes (PROs) scores included modified Harris Hip Score (mHHS), Hip Outcome Score Activities of Daily Living Subscale (HOS-AVD) and Hip Outcome Score Sport-Specific Subscale (HOS-SSS), and International Hip Outcome Tool-12 (IHOT-12). Clinical relevance was measured with the minimal clinical important difference (MCID), patient acceptable symptom state (PASS), and substantial clinical benefit (SCB).

RESULTS

Twenty patients met the inclusion criteria. An age- and sex-matched control group of 40 patients was also selected. Arthroscopic intra-operative findings were similar between cohorts. At a mean follow-up of 50 months in the borderline hip dysplasia cohort, and 52 months in the control cohort, there was a significant improvement in PROs in both cohorts, and no significant differences could be detected at the latest follow-up. The difference in frequency of patients achieving the MCID, PASS, and SCB was not statistically significant between cohorts.

CONCLUSION

With strict patient selection criteria, hip arthroscopy may be a beneficial approach in patients with borderline hip dysplasia.

Editorial Commentary: Arthroscopy for Borderline Developmental Dysplasia of the Hip: Selection Determines the Outcomes

Although the literature has presented results that favored arthroscopic procedures in treating borderline developmental dysplasia of the hip (BDDH), it remains controversial whether arthroscopic surgery would be better than periacetabular osteotomy for BDDH. Instead of a debate on the application of arthroscopy, the issue worthy of discussion should be distinguishing suitable BDDH candidates for hip arthroscopy. First, identification of patients with real BDDH is critical for making management choices. Second, it should be distinguished whether the major symptoms result from mechanical lesions or functional hip instability. Third, once hip arthroscopy is suggested for BDDH patients, relative contraindications such as advanced age and osteoarthritis should be taken into consideration, in addition to labral repair and capsular closure or plication intraoperatively. In conclusion, more long-term and high-grade evidence is still demanded to end the debate, but we believe that an individualized management strategy based on an accurate diagnosis and comprehensive assessment will bring optimal outcomes for BDDH patients.

Hip Arthroscopy and Borderline Developmental Dysplasia of the Hip: A Systematic Review

PURPOSE

To provide an up-to-date evidence-based review of hip arthroscopy for patients with borderline developmental dysplasia of the hip (BDDH).

METHODS

Literature describing hip arthroscopy in patients with BDDH was systematically identified from PubMed, EMBASE, and Cochrane Library using the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. All studies that involved BDDH and not just those reporting their clinical outcomes were included. Methodological Index for Non Randomized Studies criteria and Newcastle-Ottawa Scale were used to assess the quality of studies. The definition of BDDH, operative technique, correlation with labrum and/or cartilage lesions, outcome, and factors associated with poor outcome were collected and analyzed.

RESULTS

Assessment of the articles yielded 28 studies involving 1502 hips that were included for final analysis. There were no studies with a high risk of bias. BDDH was defined as lateral center-edge angle of 20° to 25° in most studies. Hip arthroscopy for BDDH showed an improvement in the weighted mean postoperative modified Harris Hip Score, from 60.2 to 81.7, a relatively high rate of acquisition of minimal clinically important difference of 79.5% to 87%, and had 1.0% rate of complications. Eleven studies reported on all the patients undergoing a capsular plication. Four studies reported that BDDH was associated with cartilage damage on the femoral head. Age older than 35 or 42 years and ≥20° of femoral anteversion were reported as risk factors for poor outcomes.

CONCLUSIONS

Hip arthroscopy for BDDH with capsular plication provides improvement in patient-reported outcome measures and a relatively high rate of acquisition of minimal clinically important difference with a low rate of complications in the shorter term. BDDH may be associated with cartilage damage on the femoral head. Female sex is a factor related to good outcomes, whereas older age, excessive femoral anteversion, and anterior undercoverage of acetabulum are risk factors related to poorer outcomes.

LEVEL OF EVIDENCE

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

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.

Defining the Clinically Meaningful Outcomes for Arthroscopic Treatment of Femoroacetabular Impingement Syndrome at Minimum 5-Year Follow-up

BACKGROUND

Minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS) have gained prominence as important variables in the orthopaedic outcomes literature. In hip preservation surgery, much attention has been given to defining early clinically meaningful outcome; however, it is unknown what represents meaningful patient-reported outcome improvement in the medium to long term.

PURPOSE

(1) To define MCID, PASS, and SCB at a minimum 5 years after hip arthroscopy for femoroacetabular impingement syndrome (FAIS) and (2) to evaluate the time-dependent nature of MCID, PASS, and SCB.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Patients undergoing primary hip arthroscopy for FAIS between January 2012 and March 2014 were included. Clinical and demographic data were collected in an institutional hip preservation registry. MCID, PASS, and SCB were calculated for each outcome score including the Hip Outcome Score-Activities of Daily Living subscale (HOS-ADL), Hip Outcome Score-Sport-Specific subscale (HOS-SS), modified Harris Hip Score (mHHS), and International Hip Outcome Tool (iHOT-12) at 1, 2, and 5 years. MCID was calculated by use of a distribution-based method, whereas PASS and SCB were calculated by use of an anchor method.

RESULTS

The study included 283 patients with a mean ± SD age of 34.2 ± 11.9 years. The mean changes in 1-year, 2-year, and 5-year scores, respectively, required to achieve MCID were as follows: HOS-ADL (8.8, 9.7, 10.2); HOS-SS (13.9, 14.3, 15.2); mHHS (6.9, 9.2, 11.4); and iHOT-12 (15.1, 13.9, 15.1). The threshold scores for achieving PASS were as follows: HOS-ADL (89.7, 88.2, 99.2); HOS-SS (72.2, 76.4, 80.9); mHHS (84.8, 83.3, 83.6); and iHOT-12 (69.1, 72.2, 74.3). Last, the threshold scores for achieving SCB scores were as follows: HOS-ADL (89.7, 91.9, 94.6); HOS-SS (78.1, 77.9, 85.8); mHHS (86.9, 85.8, 94.4); and iHOT-12 (72.6, 76.8, 87.5). More patients achieved MCID, SCB, and PASS at 2-year compared with 1-year follow-up; however, by 5 years, fewer patients had achieved clinically meaningful outcome (minimum 1-, 2-, and 5-year follow-up, respectively: MCID, 82.6%, 87.3%, 79.3%; PASS, 67.6%, 74.9%, 67.5%; SCB, 62.3%, 67.2%, 56.6%).

CONCLUSION

The greatest proportion of patients achieved MCID, PASS, and SCB at 2-year follow-up after arthroscopic treatment of FAIS compared with 1- and 5-year time points. Improvements were maintained out to 5-year follow-up, although the proportion of patients achieving clinical significance was slightly decreased.

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

What is the Role of Kinesiophobia and Pain Catastrophizing in Outcomes After Hip Arthroscopy for Femoroacetabular Impingement Syndrome?

Purpose

To (1) investigate trends in kinesiophobia and pain catastrophizing after hip arthroscopy for femoroacetabular impingement syndrome (FAIS), and (2) determine whether kinesiophobia and pain catastrophizing scores are associated with achieving minimal clinically important difference (MCID) for any of the hip-specific patient-reported outcome questionnaires.

Methods

Patients undergoing primary hip arthroscopy for treatment of FAIS between December 2016 and March 2017 were prospectively enrolled. Patients received the Tampa Scale of Kinesiophoibia-11 (TSK-11) and Pain Catastrophizing Scale (PCS) questionnaires preoperatively, 6 months, and 1 year postoperatively. They also received the hip-specific patient-reported outcome questionnaires (Hip Outcome Score Activities of Daily Living and Sport-Specific subscales, modified Harris Hip Score, and International Hip Outcome Tool-12), as well as visual analog scale for satisfaction and pain preoperatively and 1-year postoperatively. The threshold for achieving MCID was determined for each hip outcome tool, and patients achieving MCID were compared with those who did not.

Results

A total of 85 (80.2%) patients (mean age: 33.7 ± 12.4 years; female: 75.3%) were included in the final analysis. At 1-year follow-up, there was a significant reduction in TSK-11 scores (26.22 ± 5.99 to 18.70 ± 6.49; P < .001) and PCS scores (17.81 ± 10.13 to 4.77 ± 7.57; P < .001) when compared with preoperative scores. 1-year PCS scores were significantly lower in patients achieving MCID compared with patients failing to achieve MCID (3.2 ± 4.4 vs 10.8 ± 15.2; P = .006). There were no significant differences in TSK-11 scores between those achieving and not achieving MCID.

Conclusions

Patient kinesiophobia and pain catastrophizing both show significant improvements 1 year after undergoing hip arthroscopy for FAIS. However, pain catastrophizing scores at 1 year are significantly greater in patients not achieving MCID, whereas no association was identified between kinesiophobia and likelihood for MCID achievement. This suggests PCS may be a more useful tool than TSK-11 during postoperative rehabilitation for identifying patients at risk for not achieving MCID.

Level of Evidence

Level II, prospective case series.