Femoroacetabular Impingement: Have We Hit a Global Tipping Point in Diagnosis and Treatment? Results From the InterNational Femoroacetabular Impingement Optimal Care Update Survey (IN FOCUS)

Inflammatory and Immunologic Contributions in Femoroacetabular Impingement Syndrome

Femoroacetabular impingement (FAI) is one of the most common causes of labral and early cartilage damage in the nondysplastic hip. FAI is increasingly recognized as a cause for hip and groin pain in the young, active patient, and the surgical treatment of FAI with hip arthroscopy has risen exponentially. Although our understanding of FAI and the progression to degenerative osteoarthritis of the hip has historically been considered a mechanical "wear-and-tear" disease of an imperfectly shaped, aspherical, femoral head within a deep or overcovering acetabulum leading to cartilage injury, our understanding of the intrinsic pathophysiologic mechanisms underlying the development of FAI and joint degeneration of the hip remains poor. For example, many patients with FAI morphology may never develop hip pain or osteoarthritis; there remains more to discover regarding the pathophysiology of arthritis in the setting of FAI. Recent work has begun to identify a strong inflammatory and immunologic component to the FAI disease process that affects the hip synovium, labrum, and cartilage and may be detectable from peripheral clinical samples (blood and urine). This review highlights our current understanding of the inflammatory and immunologic contributions to FAI and potential therapeutic strategies to supplement and augment the surgical management of FAI.

Return to sport after arthroscopic surgery for femoroacetabular impingement

BACKGROUND

Femoroacetabular impingement (FAI) is common among the active and young population. The present study analysed the rate of return to sport, related influencing factors, and the sport activity level according to the Hip Outcome Score - Sport-Specific Subscale (HOS-SSS).

METHODS

The literature search was performed in December 2020. All clinical trials investigating HOS-SSS and/or return to sport after arthroscopic treatment for FAI were considered for inclusion. The outcomes of interest were to analyse the rate of return to sport and the sport activity level according to the HOS-SSS in patients who underwent arthroscopic osteoplasty for FAI.

RESULTS

Data from 41 studies (4063 procedures) were retrieved. A total of 88.75% (581 of 655) of patients returned to sports within a mean of 37.4 ± 16.5 months. The HOS-SSS score improved from 45.0 ± 10.6 to 73.1 ± 9.5 (P < 0.0001) at last follow-up. The following baseline characteristics evidenced positive association with post-operative activity level: lighter weight (P = 0.01), younger age (P = 0.001), Tönnis angle grade I (P = 0.009), greater HHS (P = 0.01), NAHS (P < 0.0001) and HOS-ADL (P = 0.01).

CONCLUSION

Arthroscopic treatment for FAI resulted in excellent results in terms of return to sport. Moreover, lighter weight and younger age, greater HHS, NAHS, HOS-ADL at baseline were positively associated with post-operative sport activity level.

LEVEL OF EVIDENCE

IV, systematic review.

Defining Parameters for Surgical Correction and Hip Complications for Femoroacetabular Impingement Syndrome: Results of an International Modified Delphi Study

OBJECTIVES

To develop recommendations for clinical and radiographic criteria to help define the "acceptable" surgical correction of femoroacetabular impingement syndrome (FAIS) and identify/define complications postoperatively.

METHODS

A 3-phase modified Delphi study was conducted involving a case-based survey; a Likert/multiple choice-based survey concerning radiographic and physical examination characteristics to help define FAIS correction, as well as the prevalence and definition of potential postoperative complications; and 2 consensus meetings.

RESULTS

Of the 75 experts invited, 54 completed the Phase I survey, 50 completed the Phase II survey (72% and 67% response rate), and 50 participated in the Phase III consensus meetings. For both typical and atypical (complex) cases, there was consensus that fluoroscopy with multiple views and dynamic hip assessment should be used intraoperatively (96% and 100%, respectively). For typical FAIS cases, the Expert Panel agreed that Dunn lateral and anteroposterior radiographs were the most important radiographs to evaluate the hip postoperatively (88%, consensus). When asked about evaluating the correction of cam impingement postoperatively, 87% voted that they use subjective evaluation of the "sphericity" of the femoral head. In the case of focal and global pincer-type FAIS, there was consensus that the reduction or elimination of the crossover sign (84%) and lateral center-edge angle (91%) were important to inform the extent of the FAIS correction. There was consensus for recommending further investigation at 6 months postoperatively if hip pain had increased/plateaued (92% agreed); that additional investigation and treatment should occur between 6 and 12 months (90% agreed); and that a reoperation may be recommended at 12 months or later following this investigation period (89% agreed).

CONCLUSIONS

This consensus project identified the importance of using fluoroscopy and dynamic hip assessment intraoperatively; Dunn lateral and anteroposterior view radiographs postoperatively; evaluating the "sphericity" of the femoral head for cam-type correction and the use of dynamic hip assessment; reducing/eliminating the crossover sign for focal pincer-type FAIS; evaluating the lateral center-edge angle for global pincer-type FAIS; and avoiding overcorrection of pincer-type FAIS. In cases in which postoperative hip pain increased/plateaued, further investigation and treatment is warranted between 6 and 12 months, and a reoperation may be recommended at a minimum of 12 months depending on the cause of the hip pain.

CLINICAL RELEVANCE

Hip arthroscopy surgeons have yet to reach a firm agreement on what constitutes an "acceptable" or "good" surgery radiographically and how they can achieve desired clinical outcomes. Although this was a comprehensive effort, more study is needed to determine therapeutic thresholds that can be universally applied.

Incidence of Symptomatic Femoroacetabular Impingement: A 4-Year Study at a National Collegiate Athletic Association Division I Institution

Background:

Femoroacetabular impingement (FAI) is an increasingly recognized cause of hip pain in young athletes. Although there are multiple studies that describe the radiographic prevalence of FAI in athletes, its true incidence within this population is unknown.

Purpose:

To report on the overall and sport-specific incidence of symptomatic FAI in National Collegiate Athletic Association (NCAA) Division I athletes. Return-to-sport times were reported for patients treated operatively.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

A retrospective review was conducted to identify all reported hip injuries within a large, multisport NCAA Division I institution. Hip injuries were stratified into FAI, general pain/dysfunction, musculotendinous, ligament, bursitis, bone stress, contusion, and other. FAI was diagnosed based on history, physical examinations, imaging, and symptomatic relief after a diagnostic injection. Descriptive statistics were used to calculate the overall and sport-specific incidence, and chi-square analysis was performed to identify contingency data.

Results:

In a 3-year period, a total of 5319 musculoskeletal injuries occurred in 1072 athletes. There were 491 (9.2%) hip injuries that occurred in 288 athletes, of which 40 injuries were FAI. The overall incidence of symptomatic FAI was 3.0% of the total population, 3.7% of all injured athletes, and 13.9% of athletic hip injuries. There were no statistically significant differences in FAI rates among male and female athletes overall or among male and female athletes within similar sports. Of the 19 athletes who were treated nonoperatively, 2 failed to return to play: 1 secondary to multiple musculoskeletal injuries and 1 related to cardiac issues. There were 21 hips in 20 patients that were treated operatively, with 1 athlete failing to return to sport. Return to play occurred at a mean of 202 days (range, 81-360 days) after hip arthroscopic surgery.

Conclusion:

In this large, multisport NCAA Division I cohort, the overall incidence of symptomatic FAI was 3.0% and represented 13.9% of hip injuries. The successful management of FAI with return to play was achieved by both nonoperative and operative treatment methods. The relatively low incidence of symptomatic FAI, despite reports of a high prevalence of FAI morphology in athletes, serves to emphasize the importance of clinical evaluations in treating patients with FAI.

How Does Chondrolabral Damage and Labral Repair Influence the Mechanics of the Hip in the Setting of Cam Morphology? A Finite-Element Modeling Study

BACKGROUND

Individuals with cam morphology are prone to chondrolabral injuries that may progress to osteoarthritis. The mechanical factors responsible for the initiation and progression of chondrolabral injuries in these individuals are not well understood. Additionally, although labral repair is commonly performed during surgical correction of cam morphology, the isolated mechanical effect of labral repair on the labrum and surrounding cartilage is unknown.

QUESTION/PURPOSES

Using a volunteer-specific finite-element analysis, we asked: (1) How does cam morphology create a deleterious mechanical environment for articular cartilage (as evaluated by shear stress, tensile strain, contact pressure, and fluid pressure) that could increase the risk of cartilage damage compared with a radiographically normal hip? (2) How does chondrolabral damage, specifically delamination, delamination with rupture of the chondrolabral junction, and the presence of a chondral defect, alter the mechanical environment around the damage? (3) How does labral repair affect the mechanical environment in the context of the aforementioned chondrolabral damage scenarios?

METHODS

The mechanical conditions of a representative hip with normal bony morphology (characterized by an alpha angle of 37°) and one with cam morphology (characterized by an alpha angle of 78°) were evaluated using finite-element models that included volunteer-specific anatomy and kinematics. The bone, cartilage, and labrum geometry for the hip models were collected from two volunteers matched by age (25 years with cam morphology and 23 years with normal morphology), BMI (both 24 kg/m2), and sex (both male). Volunteer-specific kinematics for gait were used to drive the finite-element models in combination with joint reaction forces. Constitutive material models were assigned to the cartilage and labrum, which simulate a physiologically realistic material response, including the time-dependent response from fluid flow through the cartilage, and spatially varied response from collagen fibril reinforcement. For the cam hip, three models were created to represent chondrolabral damage conditions: (1) "delamination," with the acetabular cartilage separated from the bone in one region; (2) "delamination with chondrolabral junction (CLJ) rupture," which includes separation of the cartilage from the labrum tissue; and (3) a full-thickness chondral defect, referred to throughout as "defect," where the acetabular cartilage has degraded so there is a void. Each of the three conditions was modeled with a labral tear and with the labrum repaired. The size and location of the damage conditions simulated in the cartilage and labrum were attained from reported clinical prevalence of the location of these injuries. For each damage condition, the contact area, contact pressure, tensile strain, shear stress, and fluid pressure were predicted during gait and compared.

RESULTS

The cartilage in the hip with cam morphology experienced higher stresses and strains than the normal hip. The peak level of tensile strain (25%) and shear stress (11 MPa) experienced by the cam hip may exceed stable conditions and initiate damage or degradation. The cam hip with simulated damage experienced more evenly distributed contact pressure than the intact cam hip, as well as decreased tensile strain, shear stress, and fluid pressure. The peak levels of tensile strain (15% to 16%) and shear stress (2.5 to 2.7 MPa) for cam hips with simulated damage may be at stable magnitudes. Labral repair only marginally affected the overall stress and strain within the cartilage, but it increased local tensile strain in the cartilage near the chondrolabral junction in the hip with delamination and increased the peak tensile strain and shear stress on the labrum.

CONCLUSION

This finite-element modeling pilot study suggests that cam morphology may predispose hip articular cartilage to injury because of high shear stress; however, the presence of simulated damage distributed the loading more evenly and the magnitude of stress and strain decreased throughout the cartilage. The locations of the peak values also shifted posteriorly. Additionally, in hips with cam morphology, isolated labral repair in the hip with a delamination injury increased localized strain in the cartilage near the chondrolabral junction.

CLINICAL RELEVANCE

In a hip with cam morphology, labral repair alone may not protect the cartilage from damage because of mechanical overload during the low-flexion, weightbearing positions experienced during gait. The predicted findings of redistribution of stress and strain from damage in the cam hip may, in some cases, relieve disposition to damage progression. Additional studies should include volunteers with varied acetabular morphology, such as borderline dysplasia with cam morphology or pincer deformity, to analyze the effect on the conclusions presented in the current study. Further, future studies should evaluate the combined effects of osteochondroplasty and chondrolabral treatment.

Arthroscopic Management of Femoroacetabular Impingement in Adolescents: A Systematic Review

BACKGROUND

Femoroacetabular impingement (FAI) is highly prevalent in adolescent athletes. There has been an increasing trend for arthroscopic surgery for FAI, and the results of several clinical studies on outcome after arthroscopic surgery for FAI are available.

PURPOSE

To conduct a systematic review to investigate the role of arthroscopic management for FAI in adolescents.

STUDY DESIGN

Systematic review.

METHODS

This systematic review was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. In August 2020, PubMed, Scopus, Google Scholar, and EMBASE were accessed. All clinical trials concerning the arthroscopic treatment for adolescents with FAI were identified. Only studies on patients aged less than 18 years at the time of surgery reporting data over a minimum follow-up of 12 months were considered.

RESULTS

Data from 406 adolescents (470 procedures; mean age at surgery, 15.9 years; mean follow-up, 30.4 months) with FAI were retrieved. At a mean of 28.0 months of follow-up, 94% of the adolescents had already returned to sport. All the scores of interest were improved at the final follow-up: visual analog scale (P = .01), modified Harris Hip Score (P < .0001), Non-Arthritic Hip Score (P = .03), Hip Outcome Score-Activities of Daily Living (P = .01), Hip Outcome Score-Sport-Specific Subscale (P < .0001), and Tegner score (P < .0001). Complications occurred in 1.1% (5/470) of procedures, and revision arthroscopy was performed in 4.7% (22/470) of procedures.

CONCLUSION

Arthroscopic surgery in adolescents with FAI achieves excellent outcomes and a high rate of return to sport, with rates of complication and revision surgery of 1% and 5%, respectively.

Rapid decline of yearly number of hip arthroscopies in Sweden: a retrospective time series of 6,105 hip arthroscopies based on a national patient data register

Background and purpose - Hip arthroscopies (HAs) have increased exponentially worldwide and are expected to continue rising. We describe time trends in HA procedures in Sweden (10 million inhabitants) between 2006 and 2018 with a focus on procedure rates, surgical procedures, and patient demographics such as age and sex distribution.Patients and methods - We retrospectively collected data from the Swedish National Patient Register (NPR) for all surgeries including surgical treatment codes considered relevant for HA from 2006 to 2018. Surgical codes were validated through a multiple-step procedure and classified into femoroacetabular impingement syndrome (FAIS) related or non-FAIS related procedure. Frequencies, sex differences, and time trends of surgical procedures and patient demographics are presented.Results - After validation of HA codes, 6,105 individual procedures, performed in 4,924 patients (mean age 34 years [SD 12]) were confirmed HAs and included in the analysis. Yearly HA procedure rates increased from 15 in 2006 to 884 in 2014, after which a steady decline was observed with 469 procedures in 2018. The majority (65%) of HAs was performed in males. Male patients were younger, and surgeries on males more frequently included an FAIS-related procedure.Interpretation - Similar to previous studies in other parts of the world, we found dramatic increases in HA procedures in Sweden between 2006 and 2014. Contrary to existing predictions, HA rates declined steadily after 2014, which may be explained by more restrictive patient selection based on refined surgical indications, increasing evidence, and clinical experience with the procedure.

Femoroacetabular impingement surgery leads to early pain relief but minimal functional gains past 6 months: experience from the FIRST trial

PURPOSE

To understand the early outcomes after hip arthroscopy and better define the trajectory of improvement in a prospective cohort of patients who have undergone hip arthroscopic osteochondroplasty for femoroacetabular impingement (FAI) syndrome.

METHODS

Data were analyzed from the Femoroacetabular Impingement RandomiSed controlled Trial (FIRST) on the 108 study patients who underwent osteochondroplasty, with or without labral repair. Study outcomes included patient-reported pain (using a 100-point Visual Analogue Scale (VAS)), hip function (using the Hip Outcome Score (HOS) and International Hip Outcome Tool (iHOT-12)), and health-related quality of life (using the EuroQol 5 Dimensions (EQ-5D)) measured at baseline, 2 weeks, 3 months, 6 months, and 12 months post-operatively.

RESULTS

There was a decrease in mean post-operative pain VAS scores from baseline. The first 2 weeks post-operative yielded the greatest reduction in pain with a mean (SD) VAS score of 37.8 (23.4), with score stabilization between 6 months (26.9 (26.9)) and 12 months (25.3 (27.6)). Mean HOS (activities of daily living) scores improved from baseline (59.7 (16.2)) starting at 6 weeks post-operative (64.1 (19.1)). The HOS (Sports) showed no improvement from baseline (41.2 (20.4)) until 3 months (49.1 (27.9)), and continued to improve at 6 months (64.1 (28.7)) and 12 months (68.6 (30.5)). The iHOT-12 scores showed functional improvement from baseline (31.3 (18.8)), as early as 6 weeks (44.9 (22.4)) up to and including 12 months (67.1 (29.7)). EQ-5D index scores showed modest steady improvement from 6 weeks to 12 months post-operative, while the EQ-5D VAS component similarly showed modest and steady improvements from 3 months onward.

CONCLUSION

Results from this study highlight that hip arthroscopic osteochondroplasty with or without labral repair for FAI leads to early pain relief. While all scores improved from baseline, functional gains appear to plateau from 6 months onwards. These data can be used to inform decision-making about timelines for rehabilitation and return to sport, a knowledge gap in the current FAI literature.

LEVEL OF EVIDENCE

II.

Association between severity of hip chondrolabral injuries, dynamic hip muscle strength and quality of life: A cross-sectional study in patients with femoroacetabular impingement syndrome scheduled for hip arthroscopy

BACKGROUND

We assessed the association between: the severity of hip chondral or labral pathology with dynamic hip muscle strength or quality of life in patients with femoroacetabular impingement syndrome scheduled for hip arthroscopy. We also assessed the association between dynamic hip muscle strength with quality of life.

METHODS

Eighty-three participants with femoroacetabular impingement syndrome scheduled for hip arthroscopy were included. We measured dynamic hip abduction and adduction muscle strength with an isokinetic dynamometer (Nm/kg), and quality of life with the iHoT-33 questionnaire. The severity of hip chondrolabral pathologies was scored using the modified Beck classification. Linear regression analyses were conducted to assess the association between severity of hip chondral or labral pathology with dynamic hip muscle strength and quality of life.

FINDINGS

The regression analyses showed no association between the (i) severity of hip chondral (adjusted r²: 0.14) or labral (adjusted r²: 0.08) pathology and quality of life (P > 0.05), (ii) between the severity of hip chondral or labral pathology and dynamic hip abduction and adduction muscle strength (P > 0.05). Significant correlation was observed for quality of life and hip abduction (adjusted r²:0.29; P < 0.001) or adduction (adjusted r²: 0.32; P < 0.001) muscle strength.

INTERPRETATION

The severity of hip chondral or labral pathologies were not associated with quality of life or dynamic hip muscle strength in participants with femoroacetabular impingement syndrome. Greater dynamic hip abduction and adduction muscle strength were associated with better quality of life in participants with femoroacetabular impingement syndrome scheduled for hip arthroscopy.

Osteochondroplasty and Labral Repair for the Treatment of Young Adults With Femoroacetabular Impingement: A Randomized Controlled Trial

BACKGROUND

Femoroacetabular impingement (FAI) is a condition known to cause hip pain in young adults.

PURPOSE

To evaluate the efficacy of the surgical correction of FAI via arthroscopic osteochondroplasty with or without labral repair compared with arthroscopic lavage of the hip joint with or without labral repair.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 220 male and female participants aged 18 to 50 years with nonarthritic FAI suitable for surgical treatment were recruited for the trial at 10 clinical centers in Canada, Finland, and Denmark between October 2012 and November 2017, of whom 214 were included in the final analysis. In the osteochondroplasty group, cam- and/or pincer-type lesions were resected using fluoroscopic guidance. In the lavage group, the joint was washed out with 3 L of normal saline. Surgeons were instructed to repair the labrum in both groups if it was mechanically unstable once probed, showing visible displacement or chondrolabral separation. The primary outcome was patient-reported pain (using the 100-point visual analog scale [VAS]) at 12 months. Secondary outcomes included hip function (Hip Outcome Score [HOS] and International Hip Outcome Tool), physical and mental health (12-Item Short Form Health Survey), and health utility (EuroQol-5 Dimensions) at 12 months as well as any reoperations and other hip-related adverse events at 24 months.

RESULTS

At 12 months, there was no difference in pain (VAS) between the groups (mean difference [MD], 0.11 [95% CI, -7.22 to 7.45]; P = .98). Also, 88.3% (189/214) of participants had a labral tear, of which 60.3% were repaired. For the secondary outcomes, there were no significant differences between treatment groups, with the exception of the HOS activities of daily living domain in which lavage showed significant improvement compared with osteochondroplasty (MD, -5.03 [95% CI, -10.40 to -0.03]; P = .049). By 24 months, there were significantly fewer reoperations reported in the osteochondroplasty group (8/105) than the lavage group (19/104) (odds ratio, 0.37 [95% CI, 0.15-0.89]; P = .026). The primary reasons for a reoperation included hip pain (15/27; 55.6%) and a reinjury of the labrum (11/27; 40.7%).

CONCLUSION

Both the osteochondroplasty and the lavage groups with or without labral repair for FAI had significantly improved pain or function significantly at 1 year. By 2 years, the reoperation rate was significantly lower in the osteochondroplasty group.

REGISTRATION

NCT01623843 (ClinicalTrials.gov identifier).

Hip Arthroscopy for Femoroacetabular Impingement: 1-Year Outcomes Predict 5-Year Outcomes

BACKGROUND

Limited evidence exists comparing short- and long-term patient-reported outcomes (PROs) and overall survival rates after hip arthroscopy for femoroacetabular impingement syndrome (FAIS).

HYPOTHESIS

Patients with high improvement (HI) versus low improvement (LI) at 1 year postoperatively would achieve higher PROs and better index procedure survival rates at 5-year follow-up.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Patients who underwent primary hip arthroscopy for FAIS between September 2012 and March 2014 with minimum 5-year outcome data were identified. Using the median 1-year change in modified Harris Hip Score (mHHS) as a threshold, HI and LI subcohorts were determined. Analysis of variance was used to compare PROs. Failure rates were determined using Kaplan-Meier and Cox proportional hazards model analyses. Regression analysis was used to identify factors associated with increasing 5-year change in mHHS and Nonarthritic Hip Score (NAHS).

RESULTS

Out of 108 eligible consecutive patients, 89 (82.4%) were included (mean [SD]: age, 43.3 [14.6] years; body mass index, 25.4 [4.5]). As compared with the LI group (n = 45), the HI group (n = 44) had a longer 5-year index surgery survival rate (mean ± SEM: 83.7 ± 3.3 months vs 68.5 ± 4.6 months; P = .012) and 5-year estimated survival rate (89% vs 71%). The HI group had a decreased risk of failure versus the LI group (hazard ratio, 0.15; P = .002). The HI group also had greater PROs than did the LI group at 1 year (mHHS: 94.8 ± 1.2 vs 72.6 ± 2.7, P < .001; NAHS: 94.0 ± 1.3 vs 75.6 ± 2.2, P < .001) and 5 years (mHHS: 86.9 ± 2.0 vs 77.6 ± 3.4, P = .017; NAHS: 92.6 ± 1.8 vs 82.7 ± 4.1, P = .020). As compared with the LI group, the HI group achieved higher rates of the Patient Acceptable Symptomatic State (PASS) and minimal clinically important difference (MCID) at 1 year (PASS: 95% vs 42%, P < .001; MCID: 100% vs 89%, P = .056) and 5 years (PASS: 77% vs 45%, P = .002; MCID: 86% vs 64%, P = .014). Linear regression demonstrated that being in the HI group (ΔmHHS, P = .041; ΔNAHS, P = .017) and decreasing body mass index (ΔmHHS, P = .055; ΔNAHS, P = .023) were associated with higher 5-year ΔPROs.

CONCLUSION

Patients with FAIS and significant improvement in the first year after hip arthroscopy had superior 5-year outcomes versus patients with persistent symptom severity. Survival rates and PROs were significantly better in patients who achieved high early outcomes at the 1-year mark.

Editorial Commentary: Defining Proficiency in Hip Arthroscopic Surgery Is Facing Its Own Learning Curve

The learning curve of hip arthroscopy has been described as steep. A wide range, between 30 and 520 cases, has been gathered as the learning curve before complications are minimized. While the precise number of cases required for proficiency has remained elusive, the heterogeneity in surgeon profile and baseline training can serve as an explanation. Moreover, as caseload increases, case complexity, revision surgeries, and outside referrals may begin to consume the greater-volume surgeon. While the learning curve remains hard to define, innovations in surgical training hold the promise of improving proficiency. Regardless of career stage, hip arthroscopists can still expect improved patient outcomes with appropriate indications and a properly executed procedure.

What can we learn from surveys? A systematic review of survey studies addressing femoroacetabular impingement syndrome

The purpose of this study was to systematically review the methodology, response rate and quality of survey studies related to femoroacetabular impingement (FAI) syndrome. A search was conducted on three databases (PubMed, EMBASE, MEDLINE) for relevant studies from database inception to 27 January 2020. Data extracted included study and survey characteristics, as well as response rates. The quality of the included studies was also assessed using a previously published quality assessment tool. Data were analysed with means, ranges, standard deviations, 95% confidence intervals and bivariate analysis. Eleven studies (13 surveys) were included in this review out of a total of 1608 initial titles found. Surveys were most often administered via the Internet (72%) to orthopaedic surgeons (54%). The mean response rate was 70.4%. The mean quality score was moderate 13.3/24 (SD ±4.3). The criterion that most often scored high was ‘clearly defined purpose and objectives’ (11/11). The most common survey topic investigated surgeons’ knowledge regarding FAI diagnosis and management (n = 7). In addition, bivariate analysis between quality score and response rate showed no significant correlation (Spearman’s rho = −0.090, P = 0.85). Overall, survey studies related to FAI syndrome most often use Internet-based methods to administer surveys. The most common target audience is orthopaedic surgeons. The topics of the surveys most often revolve around orthopaedic surgeons’ knowledge and opinions relating to the diagnosis and management of FAI syndrome. The response rate is high in patient surveys and lower in larger surgeon surveys. Overall, the studies are of moderate quality.

The evolution of femoroacetabular impingement surgical management as a model for introducing new surgical techniques

Introducing new surgical techniques and concepts can be difficult. There are many hurdles to overcome initially, such as the learning curve, equipment and technique development, before a standard of care can be established. In the past, new surgical techniques have been developed, and even widely accepted, before any scientific evaluation has been made. At that stage, it may be too late properly to evaluate the effectiveness of treatments, as the objectiveness and/or randomisation process may be obstructed. Since the introduction of evidence-based medicine (EBM), there have been high standards of scientific rigour to prove the efficacy of treatments. Based on the nature of evidence-based acceptance, innovations cannot be subjected to this final process before their evolution process is complete and, as a result, there is a need for the staged scientific development of new surgical techniques that should be adopted. This paper presents a model for this kind of stepwise introduction based on the actual evolution of FAI syndrome surgery. By following a scientific algorithmic methodology, new surgical techniques and concepts can be introduced in a stepwise manner to ensure the evidence-based progression of knowledge.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

Systematic review of non-randomized studies, Level IV.

Analysis of the referral pattern and wait time for hip arthroscopy in a single payer publicly funded health care system

RATIONALE AND OBJECTIVES

To analyse the referral pattern for hip pain and to investigate the wait time for an orthopaedic assessment by a hip arthroscopy surgeon in a single payer health care system. We hypothesized that a significant delay from time of onset of symptoms to time of assessment by a hip arthroscopy surgeon exists.

METHOD

Retrospective review of prospectively collected data in an academic hospital in a single payer health care system. An electronic database analysis was conducted searching for all referrals for hip pain between February 2017 and June 2017. Data were then analysed with the aim to identify the most common reason for hip referral, calculate the duration of symptoms between onset and orthopaedic assessment, and categorize previous investigations and treatments.

RESULTS

A total of 96 patients were included (47 male and 49 female). Main source of referrals was Family Medicine Physicians in 37% of cases and Primary Care Sports Medicine Physicians in 35%. The most common reason for referral was labral tear in 44.7% of cases followed by combined femoroacetabular impingement and labral tear in 21.8%. The duration of symptoms was longer than 2 years in 42% of cases and between 1 and 2 years in 40% of cases. Twenty percent of patients had previous intra-articular injection while 53% of patients had physiotherapy treatment (64% of patient underwent physiotherapy for longer than 6 months).

CONCLUSION

In the Canadian single payer health care system, a significant delay from the time of onset of symptoms to the time of assessment by a hip arthroscopy surgeon exists with the vast majority of patients in our cohort waiting more than 1 year. It is unknown if this delay affects the patient outcomes. This will require further investigation. Certainly, based on our findings, we should advocate for a better screening process, centralized referrals to hip arthroscopy specialists, and appropriate patient work-up.

How Should We Define Clinically Significant Outcome Improvement on the iHOT-12?

BACKGROUND

There is increased emphasis on efficiently administering patient-reported outcome measures (PROMs). The International Hip Outcome Tool-12 (iHOT-12) is a short-form version of the iHOT-33, and relatively little is known about clinically significant outcomes using the iHOT-12.

QUESTIONS/PURPOSES

The purpose of this study was to define minimal clinically important difference (MCID) and patient acceptable symptomatic state (PASS) for the iHOT-12 and to identify predictors for achieving these psychometric end points in patients undergoing arthroscopic treatment of femoroacetabular impingement (FAI).

METHODS

Data was prospectively collected and retrospectively analyzed as part of an institutional hip preservation repository. One hundred and twenty patients were included; mean age and body mass index (BMI) were 38.7 years and 25.9, respectively. A majority of patients were female (67.5%) and white (81.7%) and participated in recreational sports (79.2%). The iHOT-12 was administered pre-operatively and at 1-year follow-up to patients undergoing primary hip arthroscopy for FAI. The following anchor question was also asked at 1-year follow-up: "Taking into account all the activities you have during your daily life, your level of pain, and also your functional impairment, do you consider that your current state is satisfactory?" MCID was calculated using a distribution-based method. Receiver-operating characteristic analysis with area under the curve was used to confirm the significance of the PASS threshold.

RESULTS

Mean iHOT-12 scores improved from 35.6 at pre-operative assessment to 70.7 at 1-year follow-up. Patients indicating satisfaction with their outcome improved from 37.5 pre-operatively to 79.0 at 1-year follow-up. MCID value for the iHOT-12 was 13.0. The PASS threshold was 63.0, indicating an excellent predictive value that patients scoring above this threshold were likely to have met an acceptable symptom state. Worker's compensation patients and those with increased BMI were less likely to achieve PASS; lower pre-operative iHOT-12 score was predictive for achieving MCID, and achieving MCID was predictive for achieving PASS.

CONCLUSION

This is the first study to define PASS and MCID for the iHOT-12, which measures clinically significant outcome improvement comparably to that of other commonly used hip PROMs. As its use becomes more widespread, the iHOT-12 data-points presented in this study can be used to determine clinically significant improvement of patient-reported outcomes.

Predictors of Outcomes After Hip Arthroscopic Surgery for Femoroacetabular Impingement: A Systematic Review

Background

The benefits of hip arthroscopic surgery in the setting of femoroacetabular impingement (FAI) have been well established; however, some patients may experience a greater degree of improvement than others. Identifying positive and negative predictors of outcomes would assist the orthopaedic surgeon's management algorithm for patients with FAI.

Purpose/Hypothesis

The objective of this systematic review was to identify demographic, radiographic, and other operative predictors of positive and negative outcomes after hip arthroscopic surgery for patients with FAI. It was hypothesized that factors including FAI morphology, age, body mass index (BMI), sex, dysplasia, articular cartilage damage, radiographic joint space, and labral treatment would predict outcomes after hip arthroscopic surgery.

Study Design

Systematic review; Level of evidence, 4.

Methods

This systematic review was performed in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Three databases (Embase, PubMed, and Ovid [MEDLINE]) were searched on May 19, 2018, using terms including "hip," "arthroscopy," and "FAI." Studies were screened and data extracted in duplicate.

Results

A total of 39 studies were included in this systematic review, comprising 9272 hips with a mean age of 36.5 years (47.2% female). Younger age, male sex, lower BMI (<24.5 kg/m²), Tönnis grade 0, and preoperative pain relief from diagnostic intra-articular hip injections predicted positive outcomes. Female sex, older age (>45 years), longer duration of preoperative symptoms (>8 months), elevated BMI, increased Tönnis grade (≥1), chondral defects, decreased joint space (≤2 mm), increased Kellgren-Lawrence grade (>3), increased lateral center-edge angle (LCEA), and undergoing labral debridement alone were predictors of negative outcomes.

Conclusion

In patients with FAI, younger age, male sex, lower BMI (<24.5 kg/m²), Tönnis grade 0, and pain relief from preoperative intra-articular hip injections are significantly more likely to achieve positive outcomes after hip arthroscopic surgery. On the other hand, older age (>45 years), female sex, elevated BMI, osteoarthritic changes, decreased joint space (≤2 mm), chondral defects, increased LCEA, and undergoing labral debridement compared with labral repair are associated with negative outcomes.

The two-year incidence of hip osteoarthritis after arthroscopic hip surgery for femoroacetabular impingement syndrome

Background

One of the reported goals of hip preservation surgery is to prevent or delay the onset of osteoarthritis. This includes arthroscopic surgery to manage Femoroacetabular Impingement (FAI) Syndrome. The purpose of this study was to describe the prevalence of clinically-diagnosed hip OA within 2 years after hip arthroscopy for FAI syndrome, and 2) determine which variables predict a clinical diagnosis of OA after arthroscopy.

Methods

Observational analysis of patients undergoing hip arthroscopy between 2004 and 2013, utilizing the Military Health System Data Repository. Individuals with prior cases of osteoarthritis were excluded. Presence of osteoarthritis was based on diagnostic codes rendered by a medical provider in patient medical records. Adjusted odds ratios (95% CI) for an osteoarthritis diagnosis were reported for relevant clinical and demographic variables.

Results

Of 1870 participants in this young cohort (mean age 32.2 years), 21.9% (N = 409) had a postoperative clinical diagnosis of hip osteoarthritis within 2 years. The 3 significant predictors in the final model were older age (OR = 1.04; 95%CI = 1.02, 1.05), male sex (OR = 1.31; 95%CI = 1.04, 1.65), and having undergone an additional hip surgery (OR = 2.33; 95% CI = 1.72, 3.16). Military status and post-surgical complications were not risk factors.

Conclusion

A clinical diagnosis of hip osteoarthritis was found in approximately 22% of young patients undergoing hip arthroscopy in as little as 2 years. These rates may differ when using alternate criteria to define OA, such as radiographs, and likely underestimate the prevalence. A more comprehensive approach, considering various criteria to detect OA will likely be necessary to accurately identify the true rates. Females were at lower risk, while increasing age and multiple surgeries increased the risk for an OA diagnosis. OA onset still occurs after “hip preservation” surgery in a substantial number of individuals within 2 years. This should be considered when estimating rates of disease prevention after surgery. Prospective trials with sound methodology are needed to determine accurate rates and robust predictors of osteoarthritis onset after hip preservation surgery.

Do Your Routine Radiographs to Diagnose Cam Femoroacetabular Impingement Visualize the Region of the Femoral Head-Neck Junction You Intended?

PURPOSE

To use computer models and image analysis to identify the position on the head-neck junction visualized in 10 radiographic views used to quantify cam morphology.

METHODS

We generated 97 surface models of the proximal femur from computed tomography scans of 59 control femurs and 38 femurs with cam morphology-a flattening or convexity at the femoral head-neck junction. Each model was transformed to a position that represents the anteroposterior, Meyer lateral, 45° Dunn, modified false-profile, Espié frog-leg, modified 45° Dunn, frog-leg lateral, cross-table, 90° Dunn, and false-profile views. The position on the head-neck junction visualized from each view was identified on the surfaces. This position was then quantified by a clock face generated on the plane of the head-neck junction, in which the 12-o'clock position indicated the superior head-neck junction and the 3-o'clock position indicated the anterior head-neck junction. The mean visualized clock-face position was calculated for all subjects. Analysis was repeated to account for variability in femoral version. A general linear model with repeated measures was used to compare each radiographic view and anteversion angle.

RESULTS

Each radiographic view provided visualization of the mean clock-face position as follows: anteroposterior view, 12:01; Meyer lateral view, 1:08; 45° Dunn view, 1:40; modified false-profile view, 2:01; Espié frog-leg view, 2:14; modified 45° Dunn view, 2:35; frog-leg lateral view, 2:45; cross-table view, 3:00; 90° Dunn view, 3:13; and false-profile view, 3:44. Each view visualized a different position on the clock face (all P < .001). Increasing simulated femoral anteversion by 10° changed the visualized position of the head-neck junction to a more clockwise position (range, 0:07 to 0:29; all P < .001), whereas decreasing anteversion by 10° visualized a more counterclockwise position (range, -0:23 to -0:08; all P < .001).

CONCLUSIONS

Ten common radiographic views used to identify cam morphology visualized different clock-face positions of the head-neck junction. Our data will help clinicians to understand the position of the head-neck junction visualized for each radiographic view and make educated decisions in the selection of radiographs acquired in the clinic.

CLINICAL RELEVANCE

Our findings will aid clinicians in choosing a set of radiographs to capture cam morphology in the assessment of patients with hip pain.

Quality Assessment of Prospective Cohort Studies Evaluating Arthroscopic Treatment for Femoroacetabular Impingement Syndrome: A Systematic Review

Background

Femoroacetabular impingement (FAI) syndrome is a cause of pain and reduced range of motion in the hip joint. Given the limited number of randomized controlled trials, prospective cohort studies constitute the dominant part of the available prospective evidence evaluating relevant clinical outcomes after arthroscopic hip surgery for FAI.

Purpose

To assess the methodological quality of prospective cohort studies evaluating arthroscopic surgery for FAI and to determine whether there has been an improvement in methodological quality over time.

Study Design

Systematic review; Level of evidence, 4.

Methods

A systematic literature search was performed in PubMed, Embase (OvidSP), and the Cochrane Library. Included studies were clinical prospective cohort studies of primary arthroscopic surgery for cam and/or pincer morphology FAI. Methodological quality was assessed with the Methodological Index for Non-randomized Studies (MINORS). The mean MINORS score for studies published during the first 5 years of the period was compared with those published during the last 5 years to evaluate methodological improvement over time. The methodological quality of randomized controlled trials was also assessed with the Coleman Methodology Score.

Results

The search yielded 53 studies. There were 34 noncomparative studies, 15 nonrandomized comparative studies, and 4 randomized controlled trials. The included studies were published between 2008 and 2017. The mean ± SD MINORS score for noncomparative and comparative studies was 10.4 ± 1.4 of 16 possible and 18.7 ± 2.0 of 24 possible, respectively. The mean Coleman Methodology Score for randomized controlled trials was 79.0 ± 7.0 of 100 possible.

Conclusion

The methodological quality of prospective cohort studies evaluating arthroscopic surgery for FAI is moderate for comparative and noncomparative studies. Common areas for improvement include unbiased assessment of study endpoints and prospective sample-size calculations. Despite an increase in the number of published studies, an improvement in methodological quality over time was not observed.

[Surgical hip dislocation : Current status in the treatment of femoral acetabular impingement]

INTRODUCTION

Surgical hip dislocation (SHD) in the therapy of femoral acetabular impingement (FAI) has been mostly replaced by minimally invasive techniques. Nevertheless, in the circumstances of complex FAI types and combined impingement located in inaccessible areas of the hip, SHD is an option to reach those deformities. The advantage of the complete overview of the hip joint enables the circumferential therapy of bony deformity, but at the expense of higher invasivity. In the literature there is still a lack of mid to long-term studies of SHD to determine the overall treatment outcome. Therefore, the aim of this study is to evaluate the treatment outcome, risks and complications of SHD in FAI therapy within a mid-term follow-up.

METHODS

A total of 43 patients (mean follow-up 54 months.) with combined ventral and dorsal impingement who undertook SHD were retrospectively reviewed. Outcome parameters were range of motion (ROM), the Harris hip score (HHS), the hip outcome score (HOS), the activity level, pain, complications, conversion to total hip arthroplasty (THA) and patient specific surveys. Additionally, radiographs and the influence of preoperative osteoarthrosis were evaluated.

RESULTS

We were able to demonstrate a significant increase of ROM, HHS (69 → 80 Pkt.; p < 0.05), hip function and a decrease in pain level. The return to sport rate was 81%, but in most cases the patients had to reduce the intensity or change to a low impact sport activity. Overall, 75% were satisfied with the treatment outcome. The alpha angle improved from 70 to 45° (p < 0.05). Patients with preoperatively advanced hip osteoarthrosis showed no decent improvement of hip function. Conversion to THA was necessary in 36% of cases. The complication rate was about 13%.

CONCLUSION

SHD is successful in the treatment of combined ventral and dorsal impingement within a mid-term follow-up. The improvement of hip function and the reduction of pain symptoms is possible. In case of a manifest arthrosis an indication for SHD is no longer reasonable.

Time Required to Achieve Minimal Clinically Important Difference and Substantial Clinical Benefit After Arthroscopic Treatment of Femoroacetabular Impingement

BACKGROUND

Minimal clinically important difference (MCID) defines the minimum degree of quantifiable outcome improvement that a patient perceives as the result of an intervention or in the process of healing. Substantial clinical benefit (SCB) defines the amount of quantifiable outcome improvement that is needed for a patient to feel substantially better. Little is known about when clinically significant outcome improvement is achieved.

PURPOSE

To investigate the time-dependent nature of MCID and SCB after hip arthroscopy for femoroacetabular impingement (FAI).

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

An institutional hip preservation registry was queried. The modified Harris Hip Score, Hip Outcome Score, and 33-item International Hip Outcome Tool (iHOT-33) were administered to patients undergoing hip arthroscopy for FAI. Follow-up times for outcome measures were classified into 3 periods: 5 to 11 months (6 months), 12 to 23 months (1 year), and 24 to 35 months (2 years). Cumulative probabilities for achieving MCID and SCB were calculated with Kaplan-Meier survival curve analysis and interval censoring. A Weibull parametric regression analysis evaluated the odds of achieving earlier MCID.

RESULTS

A total of 719 patients undergoing primary hip arthroscopy were included. The mean ± SD age was 32.5 ± 10.5 years, and the majority were female (n = 380, 52.9%). Across all 4 outcome instruments, patients had the highest probability for achieving MCID and SCB by the 6-month postoperative period. The iHOT-33 demonstrated the highest probability for capturing MCID and SCB improvement at each of the 3 periods, with 76.0%, 84.8%, and 93.6% achieving MCID by 6 months, 1 year, and 2 years, respectively. Similarly, the probabilities of achieving SCB on the iHOT-33 were as follows: 57.1%, 68.0%, and 71.7%. A similar trend was demonstrated across other outcome tools. Older male patients and those with Outerbridge classification 1 to 4 (vs grade 0) had a significantly increased risk for taking a longer time to achieve MCID and SCB. Additionally, patients with higher preoperative outcome scores took a longer time to achieve MCID and SCB.

CONCLUSION

At least half of patients treated with hip arthroscopy for FAI achieve MCID and SCB within the first 6 months after the procedure. However, clinically significant outcome improvement continues to be attained until 2 years postoperatively. Female patients, younger individuals, and those without chondral defects achieve faster clinical outcome improvement. These findings can be helpful for establishing shared decision-making aids and follow-up guidelines for arthroscopic treatment of FAI.

Assessing the Outcome of Hip Arthroscopy for Labral Tears in Femoroacetabular Impingement Using the Minimum Dataset of the British Non-arthroplasty Hip Register: A Single-Surgeon Experience

PURPOSE

The aim of this study was to assess changes in British Non-arthroplasty Hip Register (NAHR) minimum dataset (MDS) patient-reported outcome measures (PROMs) after hip arthroscopy for femoroacetabular impingement (FAI) and define the relation between these and patient satisfaction. Secondary aims included exploring the impact of patient characteristics (age, sex, and social deprivation status) on MDS PROMs and satisfaction and determining the Net Promoter Score for hip arthroscopy for FAI.

METHODS

Preoperative data were collected from the NAHR, and postoperative data were collected through the NAHR, by mail, and by telephone survey. Correlations between satisfaction, International Hip Outcome Tool 12 (iHOT-12), and EQ-5D scores were explored.

RESULTS

A consecutive series of 89 primary hip arthroscopy procedures for FAI in 88 patients is reported. Patients reported improvements in the iHOT-12 score (mean, 34.08; 95% confidence interval [CI], 27.88 to 40.28; P < .001), EQ-5D index score (+0.124; 95% CI, 0.063 to 0.185; P < .001), and EQ-5D visual analog scale (VAS) (+4.49; 95% CI, -1.56 to 10.54; P = .061) after hip arthroscopy for FAI. Satisfaction was predicted by both change in iHOT-12 score (Spearman r [r_s] = 0.54, P < .001) and absolute postoperative iHOT-12 score (r_s = 0.78, P < .001), change in EQ-5D index score (r_s = 0.42, P < .001) and absolute postoperative EQ-5D index score (r_s = 0.70, P < .001), and change in EQ-5D VAS score (r_s = 0.30, P = .012) and absolute postoperative EQ-5D VAS score (r_s = 0.59, P < .001); and the strength of correlation was greater with the absolute postoperative score than with the change in score for all 3. Sex, age, and social deprivation status did not predict postoperative PROMs (P ≥ .15) or satisfaction (P ≥ .32). The postoperative iHOT-12 score correlated strongly with EQ-5D index (r_s = 0.90, P < .001) and EQ-5D VAS (r_s = 0.81, P < .001) scores. The Net Promoter Score for hip arthroscopy for FAI was 70.31.

CONCLUSIONS

This study showed significant improvements in hip-specific function (iHOT-12) and health-related quality of life (EQ-5D), as measured by the NAHR MDS, in patients undergoing hip arthroscopy for FAI. Satisfaction rates were high (75.7%) and correlated strongly with hip-specific and general health PROMs. Satisfied patients were more likely to be willing to undergo similar surgery in the future. Self-reported postoperative hip function correlated very strongly with general health-related quality of life.

LEVEL OF EVIDENCE

Level IV, case series.

Characterization and Correction of Symptomatic Hip Impingement in American Football Linemen

BACKGROUND

Femoroacetabular impingement (FAI) morphology can lead to range-of-motion deficits in football players. It is therefore important for physicians treating these players to be aware of the location and implications of FAI morphology.

PURPOSE/QUESTIONS

We sought to characterize the radiographic deformity and dynamic impingement observed in a consecutive series of American football linemen with symptomatic, mechanical hip pain who underwent surgical treatment for FAI and to use software analysis to identify the location of impingement and terminal range of motion and the effects of simulated correction.

METHODS

A retrospective analysis was conducted of 17 hips in 13 football linemen who underwent arthroscopic correction for symptomatic FAI. Computed tomography (CT) scans were used to generate preoperative three-dimensional models of the hips. Femoral and acetabular measurements, maximum hip flexion, abduction, internal rotation at 90° flexion (IR90), and flexion/adduction/internal rotation (FADIR) were determined, and areas of bony collision were defined. Simulated femoral correction was performed and motion analysis was repeated.

RESULTS

Mean femoral version was 13.1° (range, 0 to 26°), while mean femoral neck-shaft angle was 132.1° (range, 123 to 145°). Mean maximum alpha angle on the radial reformatted CT was 69.2° (range, 48 to 95°) and was located at the 12:45 clock-face position (range, 11:30 to 2:15). Mean acetabular version values at 1:30 and 3:00 were 1.1° (range, - 11 to 11°) and 12.7° (range, 2 to 20°), respectively. Fifty-three percent of hips showed a "crossover" sign. Mean lateral center-edge angle was 31.7° (range, 25 to 44°). CT-derived motion analysis demonstrated a mean preoperative flexion of 108.2° (range, 73 to 127°), IR90 of 20.5° (range, 0 to 52°), and FADIR of 12.3° (range, 0 to 39°). Simulated correction resulted in significant improvements in flexion (6.6°), IR90 (11.3°), and FADIR (10.6°).

CONCLUSIONS

While cephalad retroversion was observed in approximately half of the hips, a significant cam deformity was seen maximally at 12:45, a more posterior cam location than that of the general population. Managing this pathology required obtaining preoperative and intraoperative images to characterize lesions and allow for their complete correction. With complete correction of the deformity, simulated range of motion demonstrated significant improvement in flexion, IR90, and FADIR maneuvers.

Prevalence and Consistency in Surgical Outcome Reporting for Femoroacetabular Impingement Syndrome: A Scoping Review

PURPOSE

The purposes of this review were (1) to collate and synthesize research studies reporting any outcome measure on both open and arthroscopic surgical treatment of femoroacetabular impingement (FAI) syndrome and (2) to report the prevalence and consistency of outcomes across the included studies.

METHODS

A computer-assisted literature search of the MEDLINE, CINAHL (Cumulative Index to Nursing and Allied Health Literature), and Embase databases was conducted using keywords related to FAI syndrome and both open and arthroscopic surgical outcomes, resulting in 2,614 studies, with 163 studies involving 14,824 subjects meeting the inclusion criteria. Two authors independently reviewed study inclusion and data extraction with independent verification. The prevalence of reported outcomes was calculated and verified by separate authors.

RESULTS

Between 2004 and 2016, there has been a 2,600% increase in the publication of surgical outcome studies. Patients had a mean duration of symptoms of 27.7 ± 21.5 months before surgery. Arthroscopy was the surgical treatment used in 71% of studies. The mean final follow-up period after surgery was 32.2 ± 17.3 months. Follow-up time frames were reported in 78% of studies. Ten different patient-reported outcome measures were reported. The alpha angle was reported to be measured 42% less frequently as a surgical outcome than as a surgical indication. Surgical complications were addressed in only 53% of studies and failures in 69%. Labral pathology (91% of studies reporting) and chondral pathology (61%) were the primary coexisting pathologies reported. Clinical signs, as defined by the Warwick Agreement on FAI syndrome, were reported in fewer than 25% of studies.

CONCLUSIONS

Most FAI syndrome patients have longstanding pain and potential coexisting pathology. Patient-reported outcome measures and diagnostic imaging are the most frequently reported outcomes. Measures of hip strength and range of motion are under-reported. It is unclear whether the inconsistency in reporting is because of lack of measurement or lack of reporting of specific outcomes in these studies. Current surgical outcomes are limited to mid-term surgical follow-up time frames and inconsistent outcome reporting.

LEVEL OF EVIDENCE

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

Editorial Commentary: Safe Innovation? Arthroscopy After Traumatic Hip Dislocation

Hip arthroscopy can be helpful relative to conventional imaging when diagnosing (and treating) intra-articular injuries after a hip dislocation, but more evidence is required before adopting this approach diagnostic and therapeutic strategy.

Expert Opinion Is Necessary: Delphi Panel Methodology Facilitates a Scientific Approach to Consensus

Our current trend and focus on evidence-based medicine is biased in favor of randomized controlled trials, which are ranked highest in the hierarchy of evidence while devaluing expert opinion, which is ranked lowest in the hierarchy. However, randomized controlled trials have weaknesses as well as strengths, and no research method is flawless. Moreover, stringent application of scientific research techniques, such as the Delphi Panel methodology, allows survey of experts in a high quality and scientific manner. Level V evidence (expert opinion) remains a necessary component in the armamentarium used to determine the answer to a clinical question.

Similar views on rehabilitation following hip arthroscopy among physiotherapists and surgeons in Scandinavia: a specialized care survey

PURPOSE

The rising number of hip arthroscopies (HA) is leading to increasing numbers of patients requiring post-surgical rehabilitation; however, evidence regarding post-operative rehabilitation is currently limited. The purpose of the study was to describe and compare current rehabilitation strategies and views among surgeons and physiotherapists in Scandinavia.

METHODS

Scandinavian surgeons and physiotherapists experienced with HA and post-surgical rehabilitation were asked to complete an online survey. Ninety clinicians (28 surgeons, 62 physiotherapists) responded.

RESULTS

Both professions mostly rated physiotherapy as very or extremely important in the rehabilitation process. The majority advocated criteria-based or combined criteria- and time-based progression. Expected rehabilitation timelines were reported with large intra-professional variation but general inter-professional agreement. However, compared with physiotherapists surgeons expected fewer weeks on crutches and faster return to competitive sport. Surgeons more often reported use of evidence-based self-reported outcomes while physiotherapists more often evaluated readiness for return to play.

CONCLUSIONS

Among surgeons and physiotherapists, physiotherapy is considered very important following HA. Generally, very similar views were held between professions. Surgeons expected reduced time on crutches and to return to competitive sports than physiotherapists. Surgeons also used evidence-based self-reported outcomes to a higher degree than physiotherapists. Being the first study to provide an overview on currently applied rehabilitation strategies following HA, results of this study may guide much needed, future research on the rehabilitation process following HA.

LEVEL OF EVIDENCE

IV.

Population-based prevalence of multiple radiographically-defined hip morphologies: the Johnston County Osteoarthritis Project

OBJECTIVE

To provide the first prevalence estimates of different radiographic hip morphologies relevant to dysplasia and femoroacetabular impingement in a well-characterized USA population-based cohort.

METHODS

Cross-sectional data were from the baseline examination (1991-1997) of a large population-based prospective longitudinal cohort study (The Johnston County Osteoarthritis Project). HipMorf software (Oxford, UK) was used to assess hip morphology on anteroposterior (AP) pelvis radiographs. Weighted, sex-stratified prevalence estimates and 95% confidence intervals for four key hip morphologies (AP alpha angle, triangular index sign, lateral center edge angle (LCEA), and protrusio acetabula) were derived and further stratified by age, race and body mass index (BMI).

RESULTS

A total of 5192 hips from 2596 individuals were included (31% African American, 43% male, mean age 63 years, mean BMI 29 kg/m²). Cam morphology was seen in more than 25% of men and 10% of women. Mild dysplasia was present in about 1/3 of men and women, while pincer morphology was identified in 7% of men and 10% of women. Femoral side (cam) morphologies were more common and more frequently bilateral among men, while pincer morphologies were more common in women; mixed morphologies were infrequent. African-Americans were more likely to have protrusio acetabula than whites.

CONCLUSION

We report the first population-based prevalence estimates of radiographic hip morphologies relevant to femoroacetabular impingement (FAI) and dysplasia in the USA. These morphologies are very common, with ¼ men and 1/10 women having cam morphology, 1/3 of all adults having mild dysplasia, and 1/15 men and 1/10 women having pincer morphology in at least one hip.

Who Is Performing Hip Arthroscopy?: An Analysis of the American Board of Orthopaedic Surgery Part-II Database

BACKGROUND

Hip arthroscopy utilization has increased dramatically over the last decade. However, the lack of a formal training curriculum raises concern that inconsistent technical performance may be an issue for early-career hip arthroscopists. The purpose of the present study was to investigate hip arthroscopy utilization by early-career orthopaedic surgeons while focusing on fellowship training status to better guide future development of a hip arthroscopy training curriculum.

METHODS

The American Board of Orthopaedic Surgery (ABOS) Part-II database was used to identify candidates who had performed ≥1 hip arthroscopy procedures between 2006 and 2015. Procedures were categorized using Common Procedural Terminology (CPT) codes, and candidates were categorized by fellowship training experience. Trends in hip arthroscopy utilization were evaluated using univariate and regression analyses while stratifying by fellowship training experience.

RESULTS

Overall, 9.2% (643) of 6,987 ABOS candidates had performed ≥1 hip arthroscopy procedures. Over the study period, both the proportion of candidates performing hip arthroscopy and the proportion of hip arthroscopy procedures performed (relative to all procedures performed, of any type) increased (p < 0.001). Candidates performing hip arthroscopy most frequently reported sports medicine fellowship training (74.5%; 479 of 643). Also, among the candidates who performed hip arthroscopy, the proportion who had sports medicine fellowship training increased over the study period (p = 0.001). The majority of candidates performing hip arthroscopy (67.2%; 432 of 643) performed ≤5 hip arthroscopy procedures, while a small number of high-volume hip arthroscopists (6.5%; 42 of 643) performed 34.6% (1,403 of 4,054) of all hip arthroscopy procedures.

CONCLUSIONS

The increase in hip arthroscopy utilization in this cohort appears to have been driven primarily by the increased number of candidates performing hip arthroscopy and less by an increasing number of hip arthroscopy procedures being performed by individual candidates. The majority of candidates performing hip arthroscopy were sports-medicine-fellowship trained. This information is valuable for both trainees and educators interested in improving education and defining a curriculum for future hip arthroscopy training.

Does Hip Arthroscopy Have a Role in the Treatment of Developmental Hip Dysplasia?

BACKGROUND

Indications for hip arthroscopy in mildly dysplastic patients with a symptomatic hip remain controversial.

METHODS

This article provides a concise review of the available literature evaluating the role of hip arthroscopy in treating symptomatic dysplasia. Potential indications for hip arthroscopy in isolation are reviewed. Emerging evidence on the role of hip arthroscopy based on patient-specific pathomorphology is highlighted.

RESULTS

Hip arthroscopy in isolation may be helpful for select dysplastic patients with dynamic impingement or microinstability. Isolated arthroscopic treatment of intra-articular pathology resulting from static overload is unlikely to be successful in the long term and may be detrimental.

CONCLUSION

Arthroscopic procedures for individuals with mild dysplasia in the absence of frank instability may be effective; however, great caution should be exercised when approaching dysplastic patients with symptomatic hips.

Important clinical descriptors to include in the examination and assessment of patients with femoroacetabular impingement syndrome: an international and multi-disciplinary Delphi survey

PURPOSE

Determine which examination findings are key clinical descriptors of femoroacetabular impingement syndrome (FAIS) through use of an international, multi-disciplinary expert panel.

METHODS

A three-round Delphi survey utilizing an international, multi-disciplinary expert panel operationally defined from international publications and presentations was utilized.

RESULTS

All six domains (subjective examination, patient-reported outcome measures, physical examination, special tests, physical performance measures, and diagnostic imaging) had at least one descriptor with 75% consensus agreement for diagnosis and assessment of FAIS. Diagnostic imaging was the domain with the highest level of agreement. Domains such as patient-reported outcome measures (PRO's) and physical examination were identified as non-diagnostic measures (rather as assessments of disease impact).

CONCLUSION

Although it also had the greatest level of variability in description of examination domains, diagnostic imaging continues to be the preeminent diagnostic measure for FAIS. No single domain should be utilized as the sole diagnostic or assessment parameter for FAIS. While not all investigated domains provide diagnostic capability for FAIS, those that do not are able to serve purpose as a measure of disease impact (e.g., impairments and activity limitations). The clinical relevance of this Delphi survey is the understanding that a comprehensive assessment measuring both diagnostic capability and disease impact most accurately reflects the patient with FAIS.

LEVEL OF EVIDENCE

V.

Decreased and increased relative acetabular volume predict the development of osteoarthritis of the hip: an osteological review of 1090 hips

AIMS

Recently, there has been considerable interest in quantifying the associations between bony abnormalities around and in the hip joint and osteoarthritis (OA). Our aim was to investigate the relationships between acetabular undercoverage, acetabular overcoverage, and femoroacetabular impingement (FAI) with OA of the hip, which currently remain controversial.

MATERIALS AND METHODS

A total of 545 cadaveric skeletons (1090 hips) from the Hamann-Todd osteological collection were obtained. Femoral head volume (FHV), acetabular volume (AV), the FHV/AV ratio, acetabular version, alpha angle and anterior femoral neck offset (AFNO) were measured. A validated grading system was used to quantify OA of the hip as minimal, moderate, or severe. Multiple linear and multinomial logistic regression were used to determine the factors that correlated independently with the FHV, AV, and the FHV/AV ratio.

RESULTS

Female cadavers had smaller FHVs (standardised beta -0.382, p < 0.001), and AVs (standardised beta -0.351, p < 0.001), compared with male patients, although the FHV/AV ratio was unchanged. Every 1° increase in alpha angle increased the probability of having moderate OA of the hip compared with minimal OA by 7.1%. Every 1 mm decrease in AFNO increased the probability of having severe or moderate OA of the hip, compared with minimal OA, by 11% and 9%, respectively. The relative risk ratios of having severe OA of the hip compared with minimal OA were 7.2 and 3.3 times greater for acetabular undercoverage and overcoverage, respectively, relative to normal acetabular cover.

CONCLUSION

Acetabular undercoverage and overcoverage were independent predictors of increased OA of the hip. The alpha angle and AFNO had modest effects, supporting the hypothesis that bony abnormalities both in acetabular dysplasia and FAI are associated with severe OA. Cite this article: Bone Joint J 2017;99-B:432-9.

Defining the "Substantial Clinical Benefit" After Arthroscopic Treatment of Femoroacetabular Impingement

BACKGROUND

The minimal clinically important difference (MCID) has been defined in orthopaedics and is the smallest change that a patient considers meaningful. Less is known about improvements that the patient perceives as clinically considerable, or the substantial clinical benefit (SCB). For the young, highly functioning patient cohort with femoroacetabular impingement (FAI), the SCB is an important measure of clinical success.

PURPOSE

To derive the SCB for FAI treatment and identify outcome score thresholds and patient variables predictive of the SCB.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 2.

METHODS

The modified Harris Hip Score (mHHS), the Hip Outcome Score activities of daily living (HOS-ADL) and sport (HOS-Sport) subscales, and the international Hip Outcome Tool (iHOT-33) were prospectively administered to 364 patients with a minimum 1-year follow-up. At 1 year postoperatively, patients graded their hip function based on several anchor responses such as "no change" and "much improved." The SCB was defined as the change on each outcome tool that equated to the difference between "no change" and "much improved" on the health transition question. Receiver operating characteristic analysis with area under the curve (AUC) was used to identify optimal values that were most representative of the SCB. Multivariable analysis identified patient variables predictive of the SCB.

RESULTS

The net change in outcome scores corresponding to the SCB for the mHHS, HOS-ADL, HOS-Sport, and iHOT-33 was 19.8, 10.0, 29.9, and 24.5, respectively. The following postoperative outcome scores demonstrated excellent distinction (AUC >0.8) between "no change" and "much improved" and thus were considered absolute values for the postoperative SCB: 82.5 (mHHS), 93.3 (HOS-ADL), 84.4 (HOS-Sport), and 63.5 (iHOT-33). Preoperative scores on the HOS-ADL (83.3) and HOS-Sport (50.0) were significant threshold cutoffs, above which attaining the SCB became less likely. Younger age and lower Outerbridge grade were predictive of achieving the SCB.

CONCLUSION

The SCB has not been previously defined in the hip preservation literature and is complementary to the MCID as the upper bound for clinically significant improvement. We identified predictive preoperative and diagnostic postoperative outcome scores for the SCB that can be used to manage patient expectations and grade outcomes. These findings are objective criteria for defining clinical success after arthroscopic FAI treatment.

How Does the dGEMRIC Index Change After Surgical Treatment for FAI? A Prospective Controlled Study: Preliminary Results

BACKGROUND

Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) allows an objective, noninvasive, and longitudinal quantification of biochemical cartilage properties. Although dGEMRIC has been used to monitor the course of cartilage degeneration after periacetabular osteotomy (PAO) for correction of hip dysplasia, such longitudinal data are currently lacking for femoroacetabular impingement (FAI).

QUESTIONS/PURPOSES

(1) How does the mean acetabular and femoral dGEMRIC index change after surgery for FAI at 1-year followup compared with a similar group of patients with FAI treated without surgery? (2) Does the regional distribution of the acetabular and femoral dGEMRIC index change for the two groups over time? (3) Is there a correlation between the baseline dGEMRIC index and the change of patient-reported outcome measures (PROMs) at 1-year followup? (4) Among those treated surgically, can dGEMRIC indices distinguish between intact and degenerated cartilage?

METHODS

We performed a prospective, comparative, nonrandomized, longitudinal study. At the time of enrollment, the patients' decision whether to undergo surgery or choose nonoperative treatment was not made yet. Thirty-nine patients (40 hips) who underwent either joint-preserving surgery for FAI (20 hips) or nonoperative treatment (20 hips) were included. The two groups did not differ regarding Tönnis osteoarthritis score, preoperative PROMs, or baseline dGEMRIC indices. There were more women (60% versus 30%, p = 0.003) in the nonoperative group and patients were older (36 ± 8 years versus 30 ± 8 years, p = 0.026) and had lower alpha angles (65° ± 10° versus 73° ± 12°, p = 0.022) compared with the operative group. We used a 3.0-T scanner and a three-dimensional dual flip-angle gradient-echo technique for the dGEMRIC technique for the baseline and the 1-year followup measurements. dGEMRIC indices of femoral and acetabular cartilage were measured separately on the initial and followup radial dGEMRIC reformats in direct comparison with morphologic radial images. Regions of interest were placed manually peripherally and centrally within the cartilage based on anatomic landmarks at the clockface positions. The WOMAC, the Hip disability and Osteoarthritis Outcome Score, and the modified Harris hip score were used as PROMs. Among those treated surgically, the intraoperative damage according to the Beck grading was recorded and compared with the baseline dGEMRIC indices.

RESULTS

Although both the operative and the nonoperative groups experienced decreased dGEMRIC indices, the declines were more pronounced in the operative group (-96 ± 112 ms versus -16 ± 101 ms on the acetabular side and -96 ± 123 ms versus -21 ± 83 ms on the femoral side in the operative and nonoperative groups, respectively; p < 0.001 for both). Patients undergoing hip arthroscopy and surgical hip dislocation experienced decreased dGEMRIC indices; the decline in femoral dGEMRIC indices was more pronounced in hips after surgical hip dislocation (-120 ± 137 ms versus -61 ± 89 ms, p = 0.002). In the operative group a decline in dGEMRIC indices was observed in 43 of 44 regions over time. In the nonoperative group a decline in dGEMRIC indices was observed in four of 44 regions over time. The strongest correlation among patients treated surgically was found between the change in WOMAC and baseline dGEMRIC indices for the entire joint (R = 0.788, p < 0.001). Among those treated nonoperatively, no correlation between baseline dGEMRIC indices and change in PROMs was found. In the posterosuperior quadrant, the dGEMRIC index was higher for patients with intact cartilage compared with hips with chondral lesions (592 ± 203 ms versus 444 ± 205 ms, p < 0.001).

CONCLUSIONS

We found a decline in acetabular, femoral, and regional dGEMRIC indices for the surgically treated group at 1-year followup despite an improvement in all PROMs. We observed a similar but less pronounced decrease in the dGEMRIC index in symptomatic patients without surgical treatment indicating continuous cartilage degeneration. Although treatment of FAI is intended to alter the forces acting across the hip by eliminating impingement, its effects on cartilage biology are not clear. dGEMRIC provides a noninvasive method of assessing these effects. Longer term studies will be needed to determine whether the matrix changes of the bradytrophic cartilage seen here are permanent or clinically important.

LEVEL OF EVIDENCE

Level II, therapeutic study.

Defining modes of failure after joint-preserving surgery of the hip

Aims

Joint-preserving surgery of the hip (JPSH) has evolved considerably and now includes a number of procedures, including arthroscopy, surgical dislocation, and redirectional osteotomies of the femur and acetabulum. There are a number of different factors which lead to failure of JPSH. Consequently, it is of interest to assess the various modes of failure in order to continue to identify best practice and the indications for these procedures.

Patients and Methods

Using a retrospective observational study design, we reviewed 1013 patients who had undergone JPSH by a single surgeon between 2005 and 2015. There were 509 men and 504 women with a mean age of 39 years (16 to 78). Of the 1013 operations, 783 were arthroscopies, 122 surgical dislocations, and 108 peri-acetabular osteotomies (PAO). We analysed the overall failure rates and modes of failure. Re-operations were categorised into four groups: Mode 1 was arthritis progression or organ failure leading to total hip arthroplasty (THA); Mode 2 was an Incorrect diagnosis/procedure; Mode 3 resulted from malcorrection of femur (type A), acetabulum (type B), or labrum (type C) and Mode 4 resulted from an unintended consequence of the initial surgical intervention.

Results

At a mean follow-up of 2.5 years, there had been 104 re-operations (10.2%) with a mean patient age of 35.5 years (17 to 64). There were 64 Mode 1 failures (6.3%) at a mean of 3.2 years following JPSH with a mean patient age of 46.8 years (18 to 64). There were 17 Mode 2 failures (1.7%) at a mean of 2.2 years post-JPSH with a mean patient age of 28.9 years (17 to 42) (2% scopes; 1% surgical dislocations). There were 19 Mode 3 failures (1.9%) at a mean of 2.0 years post-JPSH, with a mean patient age of 29.9 years (18 to 51) (2% scopes; 2% surgical dislocations; 5% PAO). There were 4 Mode 4 failures (0.4%) at a mean of 1.8 years post-JPSH with a mean patient age of 31.5 years (15 to 43). Using the modified Dindo-Clavien classification system, the overall complication rate among JPSHs was 4.2%.

Conclusion

While defining the overall re-operation and complication rates, it is important to define the safety and effectiveness of JPSH. Standardisation of the modes of failure may help identify the best practice. Application of these modes to large clinical series, such as registries, will assist in further establishing how to improve the efficacy of JPSH. Cite this article: Bone Joint J 2017;99-B:303–9.

Editorial Commentary: Looking Past the Hip Joint-The Role of Pelvic Incidence in Femoroacetabular Impingement

In a retrospective comparative study, pelvic incidence was significantly less in patients with symptomatic femoroacetabular impingement (FAI), with a significant difference in FAI subgroups compared with asymptomatic volunteers. This finding may help to explain the existence of asymptomatic FAI morphology and highlight the importance of thorough assessment of the patient with hip pain.

Anterior hip capsuloligamentous reconstruction with Achilles allograft following gross hip instability post-arthroscopy

The increasing use of hip arthroscopy has led to further development in our understanding of hip anatomy and potential post-operative complications. Iatrogenic gross hip instability following hip arthroscopy is a concerning complication described in recent orthopaedic literature. Post-arthroscopy hip instability is thought to be multifactorial, related to a variety of patient, surgical and post-operative factors. Given its infrequency, there is scarcity of literature describing appropriate surgical management and operative technique for addressing this instability. This study reports a case of gross hip instability following hip arthroscopy, describing a novel technique of management through anterior hip capsuloligamentous reconstruction with Achilles tendon allograft. Level of evidence V, Case Study.

Authorship in the field of femoroacetabular impingement: an analysis of journal publications

PURPOSE

This review provides a bibliometric analysis of the contributors to the field of FAI research.

METHODS

A comprehensive search of three databases (MEDLINE, EMBASE, and PubMed) was performed to identify all clinical research articles on the topic of FAI (from inception to 2015). Cadaveric and animal studies were excluded. Study characteristics including authors, residing country of corresponding author, and journal were abstracted from the respective databases.

RESULTS

In total, 1073 articles were included in this review. There were a total of 5471 different authors who contributed to the field of FAI research, 28.3 % of whom were only published in one article. The top 20 authors were associated with over half of all publications, and research studies were typically performed in their countries of residence. The greatest proportion of FAI-related articles was published in the Journal of Arthroscopy and Clinical Orthopaedics and Related Research.

CONCLUSIONS

The number of authors contributing to FAI research is increasing, suggesting not only increasing prevalence of FAI treatment among orthopaedic surgeons but also increasing interest among hip arthroscopists in furthering understanding regarding the diagnosis and management of the condition. The number of publications produced by the top 20 authors (and their affiliated countries: USA, Switzerland, Canada, and the UK) is expected to contribute to a majority of future publications. Current trends suggest that the quality of evidence will continue to improve in the near future, as large-scale, collaborative studies are currently underway.

LEVEL OF EVIDENCE

Retrospective study, Level IV.

Sources and quality of literature addressing femoroacetabular impingement: a scoping review 2011-2015

A systematic review was performed to explore the current trends over the last 5 years in femoroacetabular impingement (FAI) literature and compare the quality and sources of publications in the literature to that published previously. We identified 1066 relevant studies including 186,572 patients. The number of publications increased during the reviewed time period with the most dramatic increase from 2011 to 2013. Seventy-three percent (N = 786) of all studies were of levels 4 and 5 quality evidence. The percent of publications which were levels 1, 2 and 3 increased by almost twofold from 16.1 % (N = 26) to 28.7 % (N = 51) between 2011 and 2015. In comparison to previous work, there has been 3.5-fold increase in the number of publications over the past 5 years with a shift towards improving the level of evidence available guiding the arthroscopic management of FAI.

LEVEL OF EVIDENCE

IV-Systematic Review.

BRAZILIAN ORTHOPEDISTS' OPINIONS AND PERCEPTIONS ON FEMOROACETABULAR IMPINGEMENT

Objective:

To assess the opinion of Brazilian orthopedists surgeons on the diagnosis and treatment of femoroacetabular impingement (FAI).

Methods:

A questionnaire was sent to several orthopedic societies around the world, including the Sociedade Brasileira de Ortopedia e Traumatologia (SBOT). This questionnaire was sent electronically and included questions on many topics related to FAI.

Results:

253 Brazilian orthopedists responded the questionnaire. Sixty-eight point nine percent worked in private practice and 23.1% in academic institutions. Pain during hip rotation was the most important finding in the clinical history according to 81.8% of the respondents and the anterior impingement sign was the most important finding in the physical examination according to 88.2%. Initial treatment was physiotherapy according to 86.2%. Surgical treatment was hip arthroscopy according to 38.8%, and via surgical hip dislocation for 14.7%.

Conclusion:

Brazilian orthopedists' opinions on FAI are similar to their international colleagues. There is considerable discrepancy in the answers provided, demonstrating a need for future investigation on FAI, in order to institute proper treatment and diagnosis protocols. Level of Evidence V. Expert Opinion.

Femoroacetabular Impingement Surgery Is on the Rise-But What Is the Next Step?

Surgery for femoroacetabular impingement (FAI) has been advocated for correction of cam and pincer hip joint morphology. Surgery for FAI was first pioneered by Myers et al, who surgically treated FAI by open dislocation. Arthroscopy was then introduced in 2005 by Sampson. Arthroscopy has continued to develop since then, with the intent of providing pain relief and improving function in patients with FAI. This Viewpoint discusses the escalating popularity of FAI surgery, the widespread acceptance of this relatively new surgical procedure, and next steps for determination of who benefits from this treatment. J Orthop Sports Phys Ther 2016;46(6):406-408. doi:10.2519/jospt.2016.0605.

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.

High affinity recognition of a Phytophthora protein by Arabidopsis via an RGD motif

The RGD tripeptide sequence, a cell adhesion motif present in several extracellular matrix proteins of mammalians, is involved in numerous plant processes. In plant-pathogen interactions, the RGD motif is believed to reduce plant defence responses by disrupting adhesions between the cell wall and plasma membrane. Photoaffinity cross-linking of [125I]-azido-RGD heptapeptide in the presence of purified plasma membrane vesicles of Arabidopsis thaliana led to label incorporation into a single protein with an apparent molecular mass of 80 kDa. Incorporation could be prevented by excess RGD peptides, but also by the IPI-O protein, an RGD-containing protein secreted by the oomycete plant pathogen Phytophthora infestans. Hydrophobic cluster analysis revealed that the RGD motif of IPI-O (positions 53-56) is readily accessible for interactions. Single amino acid mutations in the RGD motif in IPI-O (of Asp56 into Glu or Ala) resulted in the loss of protection of the 80-kDa protein from labelling. Thus, the interaction between the two proteins is mediated through RGD recognition and the 80-kDa RGD-binding protein has the characteristics of a receptor for IPI-O. The IPI-O protein also disrupted cell wall-plasma membrane adhesions in plasmolysed A. thaliana cells, whereas IPI-O proteins mutated in the RGD motif (D56A and D56E) did not.