Femoroacetabular impingement

Imaging in Hip Arthroscopy for Femoroacetabular Impingement: A Comprehensive Approach

Hip arthroscopy has experienced unprecedented growth in recent years and remains an area of booming technology and interest in orthopedic surgery. As understanding of the pathologic state of femoroacetabular impingement (FAI) has grown, imaging modalities have increased. Careful consideration of all bony and soft tissue structures in concert with physical examination findings in nonarthritic patients is necessary before any surgical intervention. This article summarizes the authors' approach to imaging in patients suspected of FAI, which facilitates careful patient selection and preoperative planning.

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

BACKGROUND

The outcomes of hip arthroscopy in the treatment of dysplasia are variable. Historically, arthroscopic treatment of severe dysplasia (lateral center-edge angle [LCEA] <18°) resulted in poor outcomes and iatrogenic instability. However, in milder forms of dysplasia, favorable outcomes have been reported.

PURPOSE

To compare outcomes after hip arthroscopy for femoroacetabular impingement (FAI) in borderline dysplastic (BD) patients compared with a control group of nondysplastic patients.

STUDY DESIGN

Cohort study; Level of evidence, 3 METHODS: Between March 2009 and July 2012, a BD group (LCEA, 18°-25°) of 46 patients (55 hips) was identified. An age- and sex-matched control group of 131 patients (152 hips) was also identified (LCEA, 25°-40°). Patient-reported outcome scores, including the modified Harris Hip Score (mHHS), the Hip Outcome Score-Activities of Daily Living (HOS-ADL) and Sport-Specific Subscale (HOS-SSS), and the International Hip Outcome Tool (iHOT-33), were collected preoperatively and at 1 and 2 years postoperatively.

RESULTS

The mean LCEA was 22.4° ± 2.0° (range, 18.4°-24.9°) in the BD group and 31.0° ± 3.1° (range, 25.4°-38.7°) in the control group (P < .001). The mean preoperative alpha angle was 66.3° ± 9.9° in the BD group and 61.7° ± 13.0° in the control group (P = .151). Cam decompression was performed in 98.2% and 99.3% of cases in the BD and control groups, respectively; labral repair was performed in 69.1% and 75.3% of the BD and control groups, respectively, with 100% of patients having a complete capsular closure performed in both groups. At a mean follow-up of 31.3 ± 7.6 months (range, 23.1-67.3 months) in unrevised patients and 21.6 ± 13.3 months (range, 4.7-40.6 months) in revised patients, there was significant improvement (P < .001) in all patient-reported outcome scores in both groups. Multiple regression analysis did not identify any significant differences between groups. Importantly, female sex did not appear to be a predictor for inferior outcomes. Two patients (4.3%) in the BD group and 6 patients (4.6%) in the control group required revision arthroscopy during the study period.

CONCLUSION

Favorable outcomes can be expected after the treatment of impingement in patients with borderline dysplasia when labral refixation and capsular closure are performed, with comparable outcomes to nondysplastic patients. Further follow-up in larger cohorts is necessary to prove the durability and safety of hip arthroscopy in this challenging group and to further explore potential sex-related differences in outcome.

Use of Hip Arthroscopy and Risk of Conversion to Total Hip Arthroplasty: A Population-Based Analysis

PURPOSE

To use population-level data to (1) evaluate the conversion rate of total hip arthroplasty (THA) within 2 years of hip arthroscopy and (2) assess the influence of age, arthritis, and obesity on the rate of conversion to THA.

METHODS

We used the State Ambulatory Surgery Databases and State Inpatient Databases for California and Florida from 2005 through 2012, which contain 100% of patient visits. Hip arthroscopy patients were tracked for subsequent primary THA within 2 years. Out-of-state patients and patients with less than 2 years follow-up were excluded. Multivariate analysis identified risks for subsequent hip arthroplasty after arthroscopy.

RESULTS

We identified 7,351 patients who underwent hip arthroscopy with 2 years follow-up. The mean age was 43.9 ± 13.7 years, and 58.8% were female patients. Overall, 11.7% of patients underwent THA conversion within 2 years. The conversion rate was lowest in patients aged younger than 40 years (3.0%) and highest in the 60- to 69-year-old group (35.0%) (P < .001). We found an increased risk of THA conversion in older patients and in patients with osteoarthritis or obesity at the time of hip arthroscopy. Patients treated at high-volume hip arthroscopy centers had a lower THA conversion rate than those treated at low-volume centers (15.1% v 9.7%, P < .001).

CONCLUSIONS

Hip arthroscopy is performed in patients of various ages, including middle-aged and elderly patients. Older patients have a higher rate of conversion to THA, as do patients with osteoarthritis or obesity.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

New perspectives on femoroacetabular impingement syndrome

Femoroacetabular impingement (FAI) is characterized by an abnormality in the shape of the femoral head-neck or acetabulum that results in impingement between these two structures. Arthroscopic treatment has become the preferred method of management of FAI owing to its minimally invasive approach. Surgical correction involves resection of impinging osseous structures as well as concurrent management of the associated chondral and labral pathology. Research from the past 5 years has shown that repair of the labrum results in a better anatomic correction and improved outcomes compared with labral debridement. Research is underway to improve cartilage assessment by using innovative imaging techniques and biochemical tests to inform predictions of prognosis. Several ongoing randomized controlled trials, including the Femoroacetabular Impingement Trial (FAIT) and the Femoroacetabular Impingement Randomized Controlled Trial (FIRST), will provide critical information regarding the diagnosis, management and prognosis of patients undergoing arthroscopic management of FAI.

Hip arthroscopy in the warrior athlete: 2 to 10 year outcomes

Hip disorders are increasingly recognized among athletic populations. The rigors of military service expose individuals to the same risks as those participating in competitive sports, compounded by potential exposure to violent macrotrauma. This is a retrospective review of prospectively collected data among 62 active duty military personnel (64 hips) with 2–10-year follow-up.

Follow-up averaged 47 months (range 24–120 months). The average age was 30 years (range 17–53 years) with 45 males and 17 females; 37 right and 27 left hips. Duration of symptoms prior to arthroscopy averaged 28 months (range 6–168 months). The average improvement was 22 points (pre-op 63; post-op 85) using the 100-point modified Harris hip score and was statistically significant (P <  0.001). Patients were improved after 60 of 64 procedures (94%) and returned to active duty following 52 (80%) and an average of 5 months (range 1 week–15 months). Forty-six (72%) underwent correction of FAI including 27 combined, 17 cam and two pincer lesions. Overall diagnoses and procedures are detailed. One patient underwent repeat arthroscopy and remained improved at 2-year follow-up; none were converted to total hip arthroplasty. There were two minor complications, a transient ulnar nerve neurapraxia and superficial sensory dysesthesias of the foot, both of which resolved within a few days. This is a heterogeneous cohort of pathology, but illustrates that hip disorders may exist among active duty military personnel and may benefit from arthroscopic intervention. A sense of awareness is important for accurate diagnosis and timely treatment.

Does Femoroacetabular Impingement Cause Hip Instability? A Systematic Review

PURPOSE

To determine whether femoroacetabular impingement (FAI) is associated with hip instability.

METHODS

A systematic search examining FAI and hip instability was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Clinical and basic science studies were included. Instability had to be documented with either a clinical or imaging examination. Studies were excluded if they did not define diagnostic criteria for FAI, involved prosthetic hips, were not in English, were review articles, or reported Level V evidence (case reports, expert opinion). Rates of FAI morphologic features in patients with documented hip instability were determined. Mechanisms and rates of FAI-induced hip subluxation were examined in basic science studies.

RESULTS

The search yielded 1,630 relevant studies. Seven studies (4 clinical and 3 basic science) met inclusion criteria. Four studies investigated an association between FAI and hip instability in 92 patients with an average age of 31 years. Seventy-six patients experienced frank dislocations and 16 experienced posterior subluxation events. The prevalence of FAI was documented in 89 patients with hip instability. The rates of cam and pincer morphologic characteristics were 74% and 64%, respectively. The average lateral center edge angle and prevalence of acetabular retroversion were 30° and 70%, respectively (n = 76 patients). All 3 basic science studies had real-time visualization of FAI-induced hip subluxations.

CONCLUSIONS

High rates of FAI morphologic characteristics are present in patients with hip instability. FAI morphologic characteristics may predispose the hip to instability through anatomic conflict caused by pincer or cam lesions (or both) levering the femoral head posteriorly.

LEVEL OF EVIDENCE

Level IV, systematic review of Level III, Level IV, and non-clinical studies.

Radiographic Identification of Arthroscopically Relevant Proximal Femoral Structures

BACKGROUND

Anatomic landmarks located on the proximal femur have only recently been defined, and there is a lack of radiographic guidelines for their locations presented in the literature. With the confident identification of these landmarks, radiographs could provide more assistance in preoperative evaluations, intraoperative guidance, and postoperative assessments.

PURPOSE

To quantify the radiographic locations of endoscopic landmarks of the proximal femur.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Ten cadaveric specimens were dissected, and radio-opaque hardware was placed for each landmark of interest. Radiographs were obtained and measurements recorded in anteroposterior (AP) and Dunn 45° views.

RESULTS

In the AP view, the gluteus medius insertion was located a mean 12.9 ± 2.4 mm and 34.7 ± 5.1 mm from the piriformis fossa and vastus tubercle, respectively. The piriformis fossa was a mean 14.8 ± 5.9 mm and 4.9 ± 1.9 mm from the anterior and posterior tips of the greater trochanter, respectively. The anterior and posterior tips of the greater trochanter were a mean 14.8 ± 5.1 mm from each other. In the Dunn 45° view, the piriformis fossa was a mean 13.3 ± 2.0 mm, and the vastus tubercle was a mean 21.5 ± 6.0 mm, from the gluteus medius insertion. Moreover, the vastus tubercle was a mean 33.5 ± 6.4 mm from the anterior tip of the greater trochanter and 31.6 ± 8.5 mm from the posterior tip of the greater trochanter.

CONCLUSION

In spite of the variation in cadaveric sizes, quantitative descriptions of endoscopic landmarks were reproducible in clinical views.

CLINICAL RELEVANCE

A detailed understanding of how the described landmarks present radiographically is relevant to preoperative planning, intraoperative evaluations, and postoperative assessments.

Arthroscopy Up to Date: Hip Femoroacetabular Impingement

PURPOSE

To provide a comprehensive review and summary of the research published in Arthroscopy: The Journal of Arthroscopic and Related Surgery and The American Journal of Sports Medicine (AJSM) related to hip arthroscopy for femoroacetabular impingement (FAI).

METHODS

A comprehensive review was conducted in duplicate of Arthroscopy and AJSM from February 2012 to February 2015 for all articles related to FAI, and a quality assessment was completed for all included studies. Clinical outcomes were dichotomized into short-term (<6 months) and midterm (<24 months) outcomes, and values were pooled when possible.

RESULTS

We identified 60 studies in Arthroscopy and 44 studies in AJSM, primarily from North America (78.8%), that predominantly assessed clinical outcomes after arthroscopic hip surgery (46.1%). Seventy-one percent of Arthroscopy studies and 20.5% of AJSM studies were Level IV evidence. The modified Harris Hip Score (mHHS) was used by 81.5% of included studies. Pooled weighted mean mHHS values after arthroscopic surgery for FAI showed improvements at the midterm from 60.5 points (range, 56.6 to 83.6 points) to 80.5 points (range, 72.1 to 98.0 points) out of a possible 100 points. Pooled weighted outcomes for labral repair showed mean mHHS improvements from 63.8 points (range, 62.5 to 69.0 points) preoperatively to 86.9 points (range, 85.5 to 89.9 points) up to 24 months postoperatively.

CONCLUSIONS

This comprehensive review of research published in Arthroscopy and AJSM over the past 3 years identified a number of key findings. Arthroscopic intervention results in improvements in functional outcomes at both the short-term and midterm for patients with symptomatic FAI in the absence of significant existing degenerative changes. Labral repair may result in improvements over labral debridement. The most commonly used outcome score was the mHHS for objective assessment of surgical success. There is a need for continued focus on improvement of methodologic quality and reporting of research pertaining to FAI.

LEVEL OF EVIDENCE

Level IV, systematic review of Level IV studies.

MRI for the preoperative evaluation of femoroacetabular impingement

Femoroacetabular impingement (FAI) refers to a condition characterized by impingement of the femoral head–neck junction against the acetabular rim, often due to underlying osseous and/or soft tissue morphological abnormalities. It is a common cause of hip pain and limited range of motion in young and middle-aged adults. Hip preservation surgery aims to correct the morphological variants seen in FAI, thereby relieving pain and improving function, and potentially preventing early osteoarthritis. The purpose of this article is to review the mechanisms of chondral and labral injury in FAI to facilitate an understanding of patterns of chondrolabral injury seen on MRI. Preoperative MRI evaluation of FAI should include assessment of osseous morphologic abnormalities, labral tears, cartilage status, and other associated compensatory injuries of the pelvis. As advanced chondral wear is the major relative contraindication for hip preservation surgery, MRI is useful in the selection of patients likely to benefit from surgery.

Teaching points

• The most common anatomical osseous abnormalities predisposing to FAI include cam and pincer lesions.

• Morphological abnormalities, labral lesions, and cartilage status should be assessed.

• In cam impingement, chondral wear most commonly occurs anterosuperiorly.

• Pre-existing advanced osteoarthritis is the strongest predictor of poor outcomes after FAI surgery.

• Injury to muscles and tendons or other pelvic structures can coexist with FAI.

Open and Arthroscopic Surgical Treatment of Femoroacetabular Impingement

Femoroacetabular impingement (FAI) is a common cause of hip pain, and when indicated, can be successfully managed through open surgery or hip arthroscopy. The goal of this review is to describe the different approaches to the surgical treatment of FAI. We present the indications, surgical technique, rehabilitation, and complications associated with (1) open hip dislocation, (2) reverse periacetabular osteotomy, (3) the direct anterior “mini-open” approach, and (4) arthroscopic surgery for FAI.

MRI of Labral and Chondral Lesions of the Hip

OBJECTIVE

Unenhanced MRI, indirect MR arthrography, and direct MR arthrography have been used in the radiologic evaluation of patients with suspected labral tears and chondral lesions of the hip. The purpose of this article is to examine the existing evidence for the use of these techniques in patients with hip pain and suspected labral or chondral abnormalities.

CONCLUSION

Evidence from a review of the radiologic literature supports the use of direct MR arthrography over unenhanced MRI and indirect MR arthrography for the detection of labral and cartilage abnormalities in the hip. Although high-resolution unenhanced 3-T MRI appears promising, limited information in the literature supports its use in the detection and characterization of chondrolabral lesions.

The Natural History of Femoroacetabular Impingement

Femoroacetabular impingement (FAI) is a clinical syndrome resulting from abnormal hip joint morphology and is a common cause of hip pain in young adults. FAI has been posited as a precursor to hip osteoarthritis (OA); however, conflicting evidence exists and the true natural history of the disease is unclear. The purpose of this article is to review the current understanding of how FAI damages the hip joint by highlighting its pathomechanics and etiology. We then review the current evidence relating FAI to OA. Lastly, we will discuss the potential of hip preservation surgery to alter the natural history of FAI, reduce the risk of developing OA and the need for future arthroplasty.

Isometric and isokinetic hip strength and agonist/antagonist ratios in symptomatic femoroacetabular impingement

OBJECTIVES

This study investigated isometric and isokinetic hip strength in individuals with and without symptomatic femoroacetabular impingement (FAI). The specific aims were to: (i) determine whether differences exist in isometric and isokinetic hip strength measures between groups; (ii) compare hip strength agonist/antagonist ratios between groups; and (iii) examine relationships between hip strength and self-reported measures of either hip pain or function in those with FAI.

DESIGN

Cross-sectional.

METHODS

Fifteen individuals (11 males; 25±5 years) with symptomatic FAI (clinical examination and imaging (alpha angle >55° (cam FAI), and lateral centre edge angle >39° and/or positive crossover sign (combined FAI))) and 14 age- and sex-matched disease-free controls (no morphological FAI on magnetic resonance imaging) underwent strength testing. Maximal voluntary isometric contraction strength of hip muscle groups and isokinetic hip internal (IR) and external rotation (ER) strength (20°/s) were measured. Groups were compared with independent t-tests and Mann-Whitney U tests.

RESULTS

Participants with FAI had 20% lower isometric abduction strength than controls (p=0.04). There were no significant differences in isometric strength for other muscle groups or peak isokinetic ER or IR strength. The ratio of isometric, but not isokinetic, ER/IR strength was significantly higher in the FAI group (p=0.01). There were no differences in ratios for other muscle groups. Angle of peak IR torque was the only feature correlated with symptoms.

CONCLUSIONS

Individuals with symptomatic FAI demonstrate isometric hip abductor muscle weakness and strength imbalance in the hip rotators. Strength measurement, including agonist/antagonist ratios, may be relevant for clinical management of FAI.

Dislocation After Hip Arthroscopy for Cam-Type Femoroacetabular Impingement Leading to Progressive Arthritis: A Case Report

CASE

We present the case of a fifty-two-year-old man who underwent hip arthroscopy for cam-type femoroacetabular impingement and had an anterior hip dislocation three weeks postoperatively. The patient did not have any of the previously identified risk factors for instability after hip arthroscopy. He underwent revision involving capsular repair and removal of loose bodies but progressed to needing total hip arthroplasty within two years.

CONCLUSION

This case illustrates that even patients without the previously reported risk factors for hip instability are at risk of dislocation after hip arthroscopy and this can lead to rapid joint degeneration necessitating arthroplasty.

Mental Health Medication Use Correlates with Poor Outcome After Femoroacetabular Impingement Surgery in a Military Population

BACKGROUND

Femoroacetabular impingement is a common cause of hip pain in young adults. Several preoperative risk factors for poor outcomes with surgery have been identified; however, to our knowledge, no study has attempted to determine the effect of psychiatric comorbidity on outcomes with femoroacetabular impingement surgery.

METHODS

A retrospective review was performed on active-duty patients at one institution undergoing surgery for femoroacetabular impingement over five years. Medical records were reviewed for demographic characteristics, radiographic data, and history of mental health medication use. Return-to-duty status was considered the primary outcome measure. Outcome scores obtained included modified Harris hip scores, Single Assessment Numeric Evaluation scores, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores, patient satisfaction, and Veterans RAND-12 scores. Patients taking mental health medication were compared with those who were not with regard to return to duty and validated patient-reported outcome measures.

RESULTS

Ninety-three patients (mean age, 32.2 years) were available for follow-up at a mean duration of 3.6 years. Of the seventeen patients discharged from service postoperatively, twelve (71%) were taking mental health medications. One-third (twenty-five) of seventy-six patients who returned to duty were taking mental health medication and this difference was significant (p < 0.006). Patients taking mental health medication had significantly poorer modified Harris hip scores (p < 0.02), WOMAC scores (p < 0.0008), and Veterans RAND-12 mental scores (p < 0.001). Antidepressant, antipsychotic, and multiple mental health medication use were all predictive of medical discharge due to hip pain.

CONCLUSIONS

Psychiatric comorbidities are an important risk factor in active-duty military personnel undergoing surgery for femoroacetabular impingement. Mental health medication use is associated with poorer outcome scores and can significantly lower the possibility of returning to active-duty status.

Comparison of T2 Values in the Lateral and Medial Portions of the Weight-Bearing Cartilage of the Hip for Patients With Symptomatic Femoroacetabular Impingement and Asymptomatic Volunteers

PURPOSE

To develop a simplified method to define a clinically relevant subregion in the course of arthroscopic treatment of femoroacetabular impingement (FAI) using T2 mapping in patients and asymptomatic volunteers. Additionally, we sought to compare the lateral and medial subregion values in asymptomatic volunteers and in patients presenting with FAI. Finally, we wanted to investigate possible associations between patients' T2 mapping values and demographic variables-i.e., alpha angle, age, sex, and body mass index (BMI).

METHODS

Twenty-five asymptomatic volunteers and 23 consecutive symptomatic patients with FAI (cam or mixed type) were prospectively enrolled and evaluated with a sagittal T2 mapping sequence. The weight-bearing region of the acetabular and femoral cartilage was manually segmented and divided into medial and lateral subregions. Median T2 values were determined, and patient characteristics were assessed as potential predictors of T2 values.

RESULTS

T2 values in the lateral portion of the acetabulum were lower than in the medial portion for both asymptomatic volunteers (43 v 53 ms; P < .001) and patients with FAI (42 v 49 ms; P = .016). The medial acetabulum (MA) of asymptomatic volunteers had higher T2 values than those of the FAI group (53 v 49 ms; P = .040). The lateral-minus-medial difference was significantly larger among asymptomatic volunteers than in patients with FAI (P = .047). Patients with FAI had higher alpha angles than those of the asymptomatic volunteers, but no other associations with patient characteristics were observed.

CONCLUSIONS

This study's findings suggest that there are differences in cartilage T2 mapping values between medial and lateral weight-bearing aspects of the hip and may expand the application and usefulness of biochemical magnetic resonance imaging (MRI) techniques, specifically T2 mapping, in the diagnosis of hip cartilage damage with the evaluation of clinically relevant subregions. When comparing asymptomatic volunteers and patients with FAI presenting with cam or mixed type deformity, we observed a significant contrast between the T2 mapping values of the lateral and medial portions of the weight-bearing zone of the acetabular cartilage, whereas such contrast was not observed when zone 3 was analyzed as a whole.

LEVEL OF EVIDENCE

Level III, development of diagnostic criteria on the basis of consecutive patients with a universally applied reference gold standard.

Advanced Imaging in Femoroacetabular Impingement: Current State and Future Prospects

Symptomatic femoroacetabular impingement (FAI) is now a known precursor of early osteoarthritis (OA) of the hip. In terms of clinical intervention, the decision between joint preservation and joint replacement hinges on the severity of articular cartilage degeneration. The exact threshold during the course of disease progression when the cartilage damage is irreparable remains elusive. The intention behind radiographic imaging is to accurately identify the morphology of osseous structural abnormalities and to accurately characterize the chondrolabral damage as much as possible. However, both plain radiographs and computed tomography (CT) are insensitive for articular cartilage anatomy and pathology. Advanced magnetic resonance imaging (MRI) techniques include magnetic resonance arthrography and biochemically sensitive techniques of delayed gadolinium-enhanced MRI of cartilage (dGEMRIC), T1rho (T1ρ), T2/T2* mapping, and several others. The diagnostic performance of these techniques to evaluate cartilage degeneration could improve the ability to predict an individual patient-specific outcome with non-surgical and surgical care. This review discusses the facts and current applications of biochemical MRI for hip joint cartilage assessment covering the roles of dGEMRIC, T2/T2*, and T1ρ mapping. The basics of each technique and their specific role in FAI assessment are outlined. Current limitations and potential pitfalls as well as future directions of biochemical imaging are also outlined.

Return to sport after hip surgery for femoroacetabular impingement: a systematic review

BACKGROUND

We aimed to appraise (1) the rate of return to sport of athletes after hip surgery for femoroacetabular impingement (FAI) and (2) some aspects that may influence the return to sport.

METHODS

Four databases (EMBASE, PubMed, Web of Science, Cochrane Library) were searched until 21 October 2014. Studies evaluated return to sport of athletes who underwent hip surgery for the treatment of symptomatic FAI. A validated tool was used for quality evaluation of the studies.

RESULTS

A total of 18 case series (level of evidence IV) with moderate-to-high methodological quality were included. On average, 87% of athletes returned to sport after hip surgery for FAI and 82% returned to the same sport level as before the occurrence of the symptoms. Professional athletes seem to return to sport at a higher rate compared with recreational and collegiate athletes. Sport participation after hip arthroscopy tends to decrease for professional athletes at short-term and mid-term follow-ups. Diffuse hip osteoarthritis at the time of surgery may not allow athletes to return to sport.

CONCLUSIONS

Most athletes return to sport after hip surgery for the treatment of symptomatic FAI. The level of competition, time of evaluation after hip surgery and presence of articular cartilage lesions at the time of surgery may influence return to sport. Future studies with higher levels of evidence should describe and evaluate return to sport protocols after hip surgery for FAI.

Influence of capsular repair versus unrepaired capsulotomy on 2-year clinical outcomes after arthroscopic hip preservation surgery

PURPOSE

The primary objective of this study was to determine whether capsular management technique influences clinical outcomes at a minimum of 2 years after arthroscopic hip preservation surgery.

METHODS

A retrospective review of prospectively collected data was conducted to determine the relative influence of 2 capsular management strategies on clinical outcomes: unrepaired capsulotomy (group A) and capsular repair (group B). Four hundred three patients who had undergone arthroscopic hip preservation surgery met the inclusion criteria and had 2-year outcome data available. All patients completed 4 patient-reported outcome (PRO) questionnaires preoperatively and at a minimum of 2 years' follow-up. These included the Hip Outcome Score-Activities of Daily Living (HOS-ADL) and Hip Outcome Score-Sport-Specific Subscale (HOS-SSS) subsets, Non-Arthritic Hip Score (NAHS), and modified Harris Hip Score (mHHS).

RESULTS

Group A included 235 patients and group B, 168. The mean age of all patients at final follow-up was 36.9 years. Patients in group A were significantly older (42.3 years v 29.4 years, P < .0001) and had a significantly higher body mass index (26.8 kg/m(2)v 22.9 kg/m(2), P < .0001) compared with group B. In addition, female patients were more likely than male patients to undergo capsular repair (136 female patients v 32 male patients, P < .0001). Patients in group A also showed greater chondral damage by acetabular labrum articular disruption classification (P = .0081) and reduced preoperative PROs (HOS-ADL of 60.5 v 66.0, P = .087; HOS-SSS of 37.0 v 46.4, P = .0002; NAHS of 54.6 v 62.2, P < .0001; mHHS of 58.7 v 64.4, P = .0009; and visual analog scale score of 6.3 v 5.84, P = .028). All PROs showed statistically significant improvements for both groups at a minimum follow-up of 2 years (HOS-ADL, 60.5 to 82.2 in group A and 66 to 86.1 in group B; HOS-SSS, 36.9 to 67.3 and 46.4 to 71.2, respectively; NAHS, 54.6 to 79 and 62.2 to 82.8, respectively; visual analog scale score, 6.3 to 3.1 and 5.8 to 2.9, respectively; and mHHS, 58.7 to 81 and 64.4 to 83.8, respectively; P < .0001 for all differences). Furthermore, group B showed greater overall improvements than group A for the HOS-ADL (P = .03) and NAHS (P = .03) on uncorrected univariate analysis, but significance was lost once we controlled for confounding variables.

CONCLUSIONS

Arthroscopic capsular repair, used in conjunction with arthroscopic hip preservation surgery, appears to be safe and did not negatively influence clinical outcomes in this study. When confounding variables were controlled for, the use of capsular repair did not show clinically relevant superiority over the use of unrepaired capsulotomy.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Gait and lower extremity kinematic analysis as an outcome measure after femoroacetabular impingement surgery

PURPOSE

Lower extremity and pelvis kinematics have been shown to be abnormal in patients with femoroacetabular impingement (FAI). We conducted this systematic review to evaluate the current status of gait and lower extremity kinematics as an outcome measure in patients treated surgically for FAI.

METHODS

We searched the Embase, Medline, and PubMed databases for all reports of studies published through February 22, 2014, evaluating kinematic assessment of patients undergoing FAI surgery. A review of eligible studies was conducted, and the references were searched. Methodologic quality was evaluated for all studies that met the inclusion and exclusion criteria, and data were extracted regarding methods of kinematic assessment and clinical and kinematic outcomes.

RESULTS

We identified 633 reports, of which 5 met our eligibility criteria. These studies included a total of 58 patients with symptomatic FAI (age range, 18 to 50 years). All included studies were of moderate methodologic quality. Kinematic assessments were completed preoperatively and postoperatively with variable methodology and follow-up (range, 3 to 32 months). Most studies used high-speed motion-capture camera systems with reflective tracking markers to evaluate in vivo kinematic function. Of the 5 included studies, 3 documented kinematic improvements postoperatively particularly regarding sagittal hip range of motion primarily with flexion (weighted mean, 35.1° ± 5.4° preoperatively and 37.8° ± 6.3° postoperatively).

CONCLUSIONS

Gait and lower extremity kinematics can be used as an outcome measure after FAI surgery. However, the lack of uniformity in the methodology used and underpowered case series limit the ability to identify clear and predictable differences after corrective surgery for FAI. Though statistically significant, functional outcome improvements were often conflicting and not necessarily of clinical significance. A uniform outcome measure and technique to reliably assess in vivo hip motion are required for future comparative studies.

LEVEL OF EVIDENCE

Level IV, systematic review of Level IV studies.

Improved outcomes after hip arthroscopic surgery in patients undergoing T-capsulotomy with complete repair versus partial repair for femoroacetabular impingement: a comparative matched-pair analysis

BACKGROUND

Hip capsular management after hip arthroscopic surgery for femoroacetabular impingement (FAI) is controversial.

PURPOSE/HYPOTHESIS

To compare the clinical outcomes of patients undergoing hip arthroscopic surgery for FAI with T-capsulotomy with partial capsular repair (PR; closed vertical incision, open interportal incision) versus complete capsular repair (CR; full closure of both incisions). The hypothesis was that there would be improved clinical outcomes in patients undergoing CR compared with those undergoing PR.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Consecutive patients undergoing hip arthroscopic surgery for FAI by a single fellowship-trained surgeon from January 2011 to January 2012 were prospectively collected and analyzed. Inclusion criteria included all patients between ages 16 and 65 years with physical examination and radiographic findings consistent with symptomatic FAI, with a minimum 2-year follow-up. For analysis, patients were matched according to sex and age ±2 years. Primary clinical outcomes were measured via the Hip Outcome Score Activities of Daily Living (HOS-ADL) and Sport-Specific (HOS-SS) subscales, the modified Harris Hip Score (mHHS), patient satisfaction (measured on a visual analog scale), and clinical improvement at baseline, 6 months, 1 year, and 2 years. Statistical analysis was performed utilizing Student paired and unpaired t tests, with P < .05 considered significant.

RESULTS

A total of 64 patients were included in the study, with 32 patients (12 male, 20 female) in each group. The average follow-up was 29.9 ± 2.6 months. There were no significant demographic differences between the groups. The CR group demonstrated significantly superior outcomes in the HOS-SS at 6 months (PR: 63.8 ± 31.1 vs CR: 72.2 ± 16.1; P = .039), 1 year (PR: 72.7 ± 14.7 vs CR: 82.5 ± 10.7; P = .006), and 2.5 years (PR: 83.6 ± 9.6 vs CR: 87.3 ± 8.3; P < .0001) after surgery. Patient satisfaction at final follow-up was significantly better in the CR group (PR: 8.4 ± 1.0 vs CR: 8.6 ± 1.1; P = .025). Both groups demonstrated significant improvements in the HOS-ADL (PR: 64.6 ± 17.0 to 90.7 ± 8.4 [P < .0001]; CR: 66.1 ± 15.7 to 92.1 ± 7.9 [P < .0001]) and HOS-SS (PR: 39.4 ± 23.9 to 83.6 ± 9.6 [P < .0001]; CR: 39.1 ± 24.2 to 87.3 ± 8.3 [P < .0001]) at final follow-up. There were no significant differences between the groups in the HOS-ADL at any time point. There were no significant differences in the mHHS between the groups at final follow-up (PR: 82.5 ± 5.0 vs CR: 83.0 ± 4.4; P = .364). The overall revision rate was 6.25%; all patients (n = 4) who required revision arthroscopic surgery were in the PR group (13% of 32 patients), while no patients in the CR group required revision surgery.

CONCLUSION

While significant improvements were seen at 6 months, 1 year, and 2.5 years of follow-up regardless of the closure technique, patients who underwent CR of the hip capsule demonstrated superior sport-specific outcomes compared with those undergoing PR. There was a 13% revision rate in the PR group, but no patients in the CR group required revision surgery. While longer term outcome studies are needed to determine if these results are maintained over time, these data suggest improved outcomes after CR compared with PR at 2.5 years after hip arthroscopic surgery for FAI.

Factors associated with the failure of arthroscopic surgery treatment in patients with femoroacetabular impingement: A cohort study

OBJECTIVE

The aim of this study was to evaluate the association of the anatomical and functional characteristics with therapeutic failure in patients with femoroacetabular impingement, who underwent hip arthroscopy.

MATERIALS AND METHODS

A cohort study was performed on 179 patients with femoroacetabular impingement who underwent hip arthroscopy between 2004 and 2012. The demographic, anatomical, functional, and clinical information were recorded. A logistic regression model and ANCOVA were used in order to compare the described characteristics with the treatment outcomes of the hip arthroscopy.

RESULTS

The median time of follow-up for symptoms was 13 months (8-30), and the mean time of follow-up after surgery was 23.83 ± 9.8 months. At the end of the follow-up 3.91% of the patients were considered as a therapeutic failure. The WOMAC score in pain and functional branches, as well as the total WOMAC score, showed significant differences (P<.05). The mean WOMAC score was higher (0 to 100 with 0 being a perfect score) in the group of patients who failed after surgery as compared with the group who meet the requirements for a successful treatment, 65.9 vs 48.8, respectively (mean difference 17.0; 95% CI; 1.3-32.6; P=.033).

CONCLUSION

The poor functional state prior to arthroscopic treatment of femoroacetabular impingement, mainly due to preoperative pain, assessed using the WOMAC scale, is associated with a higher therapeutic failure rate.

Operative treatment of femoroacetabular impingement

Femoroacetabular impingement is a common pathologic disorder of the hip that causes pain and has been implicated in the development of early osteoarthritis in young adults. This disorder includes 2 different subtypes: cam impingement and pincer impingement. When nonsurgical treatment methods fail, surgical options are indicated. These options have been increasingly investigated over recent years and show promising results. Several surgical techniques have been described, including surgical dislocation of the hip, mini-open procedures, hip arthroscopy, and periacetabular osteotomies. Nevertheless, the preferred mode of surgical management of femoroacetabular impingement remains a source of controversy. Only short-term and midterm outcome data are available regarding the efficacy of these surgical techniques. This review details 5 approaches for surgical management of femoroacetabular impingement: open surgical dislocation, a combined arthroscopic and open approach, hip arthroscopy, a mini-open anterior approach, and periacetabular osteotomy. It focuses specifically on surgical technique, outcomes, and their efficacy in treatment of femoroacetabular impingement.

Arthroscopic technique for treatment of combined pathology associated with femoroacetabular impingement syndrome using traction sutures and a minimal capsulotomy

The use of hip arthroscopy is gaining popularity for diagnostic and therapeutic purposes. With our increasing understanding of hip biomechanics and pathophysiology, our techniques for treatment are evolving as well. The main aim is to preserve the joint and prolong the degenerative process associated with femoroacetabular impingement (FAI). In general, combined pathology is encountered when a diagnosis of FAI is established. In our experience, we have seen large number of patients with a combination of cam and pincer lesions with or without associated labral tears. It is optimal to address all symptomatic pathology with one surgical intervention. The described technique shows the feasibility of dealing with the hip FAI pathology by using traction sutures on the capsule through a 2-portal technique.

[Hip arthroscopy in males younger than 40 with femoroacetabular impingement: short-term outcomes]

INTRODUCTION AND OBJECTIVES

Femoroacetabular impingement is probably the most common mechanism that leads to the development of early cartilage and labral damage in the non-dysplastic hip. The objective was to evaluate the outcomes of hip arthroscopy as a treatment for femoroacetabular impingement in patients with high level of function.

MATERIAL AND METHODS

A prospective study was performed on 41 patients younger than 40 years old undergoing hip arthroscopy for femoroacetabular impingement. Modified Harris Hip Score and HOS and IHOT questionnaires were used for clinical assessment. Radiological evaluation was made for joint space and alpha angle.

RESULTS

The mean age of patients was 32.7 years. Labrum injury was detected in 78%, and acetabular cartilage injury in 56% of cases. The average follow-up was 31.3 months. There was a significantly improvement in the mean score in the clinical questionnaires. Radiologically there was no change in the mean joint space, with significantly reduction to normal values of the alpha angle. All patients returned to sports at their pre-injury level of function.

DISCUSSION

Hip arthroscopy resulted in improvement in hip functional outcomes with correction of the underlying osseous deformity and treatment of the associated labral and cartilage pathology, with the return of patients to their pre-injury sports. Further follow-up is essential to confirm the stability of the clinical and radiological outcomes.

What's New in Femoroacetabular Impingement Surgery: Will We Be Better in 2023?

Context:

Femoroacetabular impingement (FAI) has been described as a common cause of hip pain in young adults. This leads to abnormal hip joint mechanics and contact pressures. The associated pathomechanics can lead to the development of early osteoarthritis. Better understanding of the anatomy and pathophysiology, biomechanics, and diagnostic and therapeutic advances has led to improved clinical outcomes. A growing body of evidence has set the foundation for future progress in the treatment of this commonly encountered condition.

Evidence Acquisition:

The PubMed database was searched for English-language articles pertaining to FAI over the past 15 years (1998-2013).

Study Design:

Retrospective literature review.

Level of Evidence:

Level 4.

Results:

The authors evaluated and discussed the current evidence regarding the anatomy, physiology, biomechanics, imaging, and clinical outcomes of surgical intervention for FAI. Based on this information, future directions for improving the diagnosis and management of FAI are proposed.

Conclusion:

There remains a diverse approach to the diagnosis and management of cam- and/or pincer-type FAI. Recent advances in clinical diagnosis, imaging, indications, and arthroscopic techniques have led to improved outcomes and have set the foundation for future progress in the management of this condition.

Strength of Recommendation Taxonomy (SORT):

B

The etiology of femoroacetabular impingement: what we know and what we don't

Context:

Several risk factors may cause femoroacetabular impingement (FAI). Knowledge of causation would identify patients for early intervention, prior to the development of painful intra-articular damage.

Data Sources:

PubMed, MEDLINE, EMBASE, and related article reference lists were screened for relevant studies published between January 2000 and December 2013.

Study Selection:

Inclusion criteria were (1) etiology of FAI, (2) original FAI clinical data, and (3) English language. Case reports of fewer than 3 patients were excluded.

Study Design:

Systematic review.

Level of Evidence:

Level 4.

Results:

In all, 754 studies were screened, with 18 meeting the eligibility criteria. There were 13 comparative observational studies and 5 case series. The studies pertained to intrinsic patient factors (n = 2), activity/developmental factors (n = 8), hip disease (n = 5), postsurgical changes (n = 2), and malunion after hip fracture (n = 1).

Conclusion:

A combination of intrinsic patient and developmental factors, activities involving repetitive hip motion, pediatric hip disease, and hip-related surgical procedures may contribute to the development of FAI.

Current possibilities for hip arthroplasty

Hip arthroscopy has been popularized over the last decade and, with technical advances regarding imaging diagnostics, understanding of the physiopathology or surgical techniques, several applications have been described. Both arthroscopy for intra-articular conditions and endoscopy for extra-articular procedures can be used in diagnosing or treating different conditions. This updated article has the objective of presenting the various current possibilities for hip arthroscopy.

A mountain among molehills: removing an impinging large femoral neck osteochondroma in a man with hereditary multiple exostoses

A 31-year-old man with a history of hereditary multiple exostoses (HME) presented with persistent right groin pain and reduced hip range of movement. Examination demonstrated a positive FADIR (flexion, adduction and internal rotation) test suggesting femoroacetabular impingement (FAI). Investigations showed multiple sessile osteochondromata of the right femur with a dominant anterolateral femoral neck osteochondroma causing flexion block. The patient underwent an uncomplicated proximal femoral exostectomy. Six-week postoperative pain, range of movement and daily activity had greatly improved. This case highlights that even in the setting of multiple osteochondromata, excellent impingement relief can be achieved following selective proximal femoral exostectomy.

Elevation in circulating biomarkers of cartilage damage and inflammation in athletes with femoroacetabular impingement

BACKGROUND

Femoroacetabular impingement (FAI) is one of the most common causes of early cartilage and labral damage in the nondysplastic hip. Biomarkers of cartilage degradation and inflammation are associated with osteoarthritis. It was not known whether patients with FAI have elevated levels of biomarkers of cartilage degradation and inflammation.

HYPOTHESIS

Compared with athletes without FAI, athletes with FAI would have elevated levels of the inflammatory C-reactive protein (CRP) and cartilage oligomeric matrix protein (COMP), a cartilage degradation marker.

STUDY DESIGN

Controlled laboratory study.

METHODS

Male athletes with radiographically confirmed FAI (n = 10) were compared with male athletes with radiographically normal hips with no evidence of FAI or hip dysplasia (n = 19). Plasma levels of COMP and CRP were measured, and subjects also completed the Short Form-12 (SF-12) and Hip Disability and Osteoarthritis Outcome Score (HOOS) surveys.

RESULTS

Compared with controls, athletes with FAI had a 24% increase in COMP levels and a 276% increase in CRP levels as well as a 22% decrease in SF-12 physical component scores and decreases in all of the HOOS subscale scores.

CONCLUSION

Athletes with FAI demonstrate early biochemical signs of increased cartilage turnover and systemic inflammation.

CLINICAL RELEVANCE

Chondral injury secondary to the repetitive microtrauma of FAI might be reliably detected with biomarkers. In the future, these biomarkers might be used as screening tools to identify at-risk patients and assess the efficacy of therapeutic interventions such as hip preservation surgery in altering the natural history and progression to osteoarthritis.

Cam lesion femoral osteoplasty: in vitro biomechanical evaluation of iatrogenic femoral cortical notching and risk of neck fracture

PURPOSE

To investigate the effect of femoral cortical notching at different depths on the peak compressive load and energy required to cause a femoral neck fracture in composite femurs.

METHODS

Thirty fourth-generation composite femurs were divided into 5 groups: (1) intact with an inherent alpha angle of 61°, (2) resection of inherent cam lesion by reducing the alpha angle from 61° to 45°, (3) cam resection and cortical notching of a 5.5-mm spherical diameter by 2.00-mm (grade I) depth, (4) cam resection with cortical notching of 4.00-mm (grade II) depth, and (5) cam resection with cortical notching of 6.00-mm (grade III) depth. The specimens were loaded in the position of midstance during gait and tested until failure using a dynamic tensile testing machine at a rate of 6 mm/min.

RESULTS

Grade II and grade III cortical notching depths with cam resections resulted in a significant decrease in the ultimate load to failure and energy (P < .05) compared with the intact state. The grade II and grade III cortical notching groups with cam resection failed at a significantly lower ultimate load and with significantly lower energy when compared with the cam resection group alone.

CONCLUSIONS

The findings of this study demonstrated significant decreases in ultimate load and energy to failure between the intact group and the grade II and grade III femoral cortical notching groups with cam resection.

CLINICAL RELEVANCE

Iatrogenic cortical notching may lead to an increased risk of postsurgical complications, specifically femoral neck fracture. Thus, surgical intervention for a cam lesion femoral osteoplasty should strive for precision, especially around the femoral neck.

Operative treatment of FAI: open hip preservation surgery

Femoroacetabular Impingement (FAI) is characterized by abnormal contact of the hip joint. Many etiologies cause this painful condition, which leads to early osteoarthritis. While hip arthroscopy has become the most prevalent way to surgically correct a hip, some presentations of FAI require open surgical hip preservation techniques to fully address the pathology at hand. Certain head neck deformities may require open surgical hip dislocation utilizing a trochanteric slide osteotomy. A retroverted acetabulum may require an open periacetabular osteotomy to gain anteversion and eliminate impingement in the hip joint. Acetabular protrusio may require surgical hip dislocation with rim trimming and a possible valgus intertrochanter osteotomy. The sequelae of Legg-Calvé-Perthes disease causes complex abnormalities about the hip joint, which may require open surgery to address both the intra-articular pathology and the extra-articular pathology. Osteotomies of the proximal femur and acetabulum may all be necessary to restore a hip back to normal morphology. Chronic slipped capital femoral epiphysis (SCFE) may also require open surgical hip dislocations and complex intertrochanter osteotomies to recreate normal morphology.