The Warwick Agreement on femoroacetabular impingement syndrome (FAI syndrome): an international consensus statement

Editorial Commentary: Personalized Hip Arthroscopy Outcome Prediction Using Machine Learning-The Future Is Here

Machine learning and artificial intelligence are increasingly used in modern health care, including arthroscopic and related surgery. Multiple high-quality, Level I evidence, randomized, controlled investigations have recently shown the ability of hip arthroscopy to successfully treat femoroacetabular impingement syndrome and labral tears. Contemporary hip preservation practice strives to continually refine and improve the value of care provision. Multiple single-center and multicenter prospective registries continue to grow as part of both United States-based and international hip preservation-specific networks and collaborations. The ability to predict postoperative patient-reported outcomes preoperatively holds great promise with machine learning. Machine learning requires massive amounts of data, which can easily be generated from electronic medical records and both patient- and clinician-generated questionnaires. On top of text-based data, imaging (e.g., plain radiographs, computed tomography, and magnetic resonance imaging) can be rapidly interpreted and used in both clinical practice and research. Formidable computational power is also required, using different advanced statistical methods and algorithms to generate models with the ability to predict individual patient outcomes. Efficient integration of machine learning into hip arthroscopy practice can reduce physicians' "busywork" of data collection and analysis. This can only improve the value of the patient experience, because surgeons have more time for shared decision making, with empathy, compassion, and humanity counterintuitively returning to medicine.

Comparing Patient-Reported Outcome Measurements for Femoroacetabular Impingement Syndrome

BACKGROUND

There is much debate in the current literature with regard to the most appropriate hip-specific patient-reported outcome (PRO) measurement for assessment of femoroacetabular impingement syndrome (FAIS) and outcomes after surgical treatment. Despite systematic reviews assessing the validity of classic hip-specific PROs as well as newer PROs developed to target the young, active population, there lacks a direct comparison of the question content between each PRO.

PURPOSE

To compare the question composition and degree of overlap between commonly used PROs for FAIS.

STUDY DESIGN

Cross-sectional study.

METHODS

A literature review yielded the 6 most commonly cited PROs for assessment of FAIS: modified Harris Hip Score (mHHS), Hip disability and Osteoarthritis Outcome Score (HOOS), Copenhagen Hip and Groin Outcome Score (HAGOS), Nonarthritic Hip Score (NAHS), international Hip Outcome Tool (iHOT-33), and Hip Outcome Score (HOS). Questions from each PRO were classified as identical, similar, or unique after pooled comparison, and the number of overlapping (identical or similar) questions between each PRO was determined. Questions were then classified into 5 domains: pain, symptoms, functional activities, sports, and quality of life, and variations in questions assessing each domain based on PRO were analyzed.

RESULTS

Analysis of 164 total questions from 6 PROs showed that 87 questions (53%) were identical between 2 or more PROs, 39 (24%) were similar, and 38 (23%) were unique. The iHOT-33 contained the highest number of unique questions, with 13 of 33 (39.4%), while the HOOS contained the lowest number of unique questions, with 3 of 40 (7.5%). The HOOS, HAGOS, and iHOT-33 contained questions assessing all 5 domains of patient outcomes; the NAHS did not evaluate quality of life; the mHHS only assessed pain, symptoms, and functional activities; and the HOS only assessed functional activities and sports.

CONCLUSION

As there is a high percentage of overlapping (identical or similar) questions between the most commonly used hip-specific PROs for FAIS, multiple tests may be appropriate for use. The iHOT-33, HOOS, and HAGOS are well suited for the general population as they offer comprehensive assessments across all domains, while the HOS provides added focus to sports/activity assessments for athletes and highly active patients.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

IV, Retrospective Case Series.

Hip arthroscopy with initial access to the peripheral compartment provides significant improvement in FAI patients

PURPOSE

This study was designed to evaluate the clinical and radiographic results of arthroscopic treatment of femoroacetabular impingement (FAI) using the technique of initial access to the peripheral compartment. It is based on a single surgeon large case series with a minimum of 2 years follow-up.

METHODS

Prospective longitudinal study with consecutive patients. Inclusion criteria were the presence of FAI syndrome that had failed non-operative treatment and had a hip arthroscopy with initial access to the peripheral compartment. Exclusion criteria were previous hip surgery, patients younger than 16 or older than 60 years, Tönnis grade ≥ 2 osteoarthritis, hip dysplasia based on radiographic evidence of LCEA less than 25° and workers compensation cases. One hundred and sixty hips met the inclusion criteria, 84 were female and 70 were male patients (six bilateral cases), with a median age of 36 years (range 16-59).

RESULTS

The median alpha angle correction was 22.6º (range 5.9-46.7) (p < 0.01) and the average LCEA correction when acetabuloplasty was undertaken was 6.5º (range - 1.4-20.8) (p < 0.01). The mean NAHS at baseline was 56.1 (range 16-96) and improved to 83.2 at the last follow up (range 44-100) for the patients that had no additional procedure (p < 0.01). The mean average improvement was 27.7º points (range - 16-73). No iatrogenic labral perforation and no full-thickness chondral damage were recorded during the arthroscopic procedures.

CONCLUSIONS

Favourable outcomes are reported for the arthroscopic treatment of FAI with initial access to the peripheral compartment. The technique is protective against iatrogenic chondral and labral damage, more conservative to the joint capsule, but the mean traction time was relatively long when suture anchors were used. The results are comparable to the classic initial central compartment approach.

LEVEL OF EVIDENCE

Level IV.

Six Meta-analyses on Treatments for Femoroacetabular Impingement Syndrome in a Year and Readers Are None the Wiser: Methods Advice for Researchers Planning Meta-analysis of Data From Fewer Than 5 Trials

In 2020, 6 meta-analyses comparing arthroscopic hip surgery to physical therapy were published. All included the same 3 randomized controlled trials, and none used methods suitable for the analysis of fewer than 5 studies. When there are fewer than 5 studies and heterogeneity, a random-effects model with the Hartung-Knapp-Sidik-Jonkman adjustment for a maximally conservative estimate should be employed; if reliable prior information is available, a Bayesian random-effects meta-analysis should be employed. Our re-analysis, which employed the appropriate model, found that there is currently insufficient evidence to conclude that surgery is superior to physical therapy for femoroacetabular impingement (FAI) syndrome. Further randomized controlled trials are required to resolve the clinical question of what the best treatment approach is for FAI syndrome. We provide readers with tools to conduct appropriate meta-analysis of fewer than 5 trials. J Orthop Sports Phys Ther 2021;51(5):201-203. doi:10.2519/jospt.2021.0107.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Femoroacetabular impingement: correlation between imaging parameters, sport activity, and chondral damage

BACKGROUND

Femoroacetabular impingement is characterised by an abnormal contact between the acetabulum and the femoral head-neck junction. Femoroacetabular impingement shows three main clinical frameworks: Pincer-FAI, Cam-FAI and Cam-Pincer mixed form. The aim of the study was to investigate the correlation between femoroacetabular impingement, imaging, activity and chondral damages.

METHODS

Forty-one patients, undergoing arthroscopic chondroartroplasty for Cam and Cam-Pincer mixed form were considered. All patients underwent an X-ray hip evaluation (G1 group), while 15 patients also underwent a pelvis MRI evaluation (G2 subgroup). For G1 patients, the superior-inferior offset ratio and alpha angle were calculated from the X-ray examinations. For G2 patients, the antero-posterior offset ratio was also calculated from pelvis MRI. Chondral damage was classified according to the Outerbridge classification.

RESULTS

The superior-inferior offset ratio and the antero-posterior offset ratio were respectively 0.50 ± 0.23 and 0.33 ± 0.19. The α angle predictive for a chondral damage of IV degree was 81.5°.The chondral damage of the patients suffering from Cam-FAI and Cam-Pincer mixed form were respectively 3.53±0.80 and 3.00±1.41.

CONCLUSIONS

From the results was possible to: - Elaborate two tables providing a reliable indirect calculation of the alpha angle. - Establish an alpha angle cut-off value indicative for a IV degree chondral damage. - Show that Pincer-FAI does not represent an aggravating factor for chondral damage - Show that the level of sports activity was related to the severity of chondral damage. - Show that a physically demanding occupation was not an aggravating factor for chondral damage.

How Many Patients Achieve an Acceptable Symptom State After Hip Arthroscopy for Femoroacetabular Impingement Syndrome? A Cross-sectional Study Including PASS Cutoff Values for the HAGOS and iHOT-33

Background

Hip arthroscopy is a viable treatment for femoroacetabular impingement syndrome (FAIS). Clinically relevant improvements in hip function and pain after surgery are often reported, but it is less clear how many patients achieve an acceptable symptom state (Patient Acceptable Symptom State [PASS]).

Purpose

To investigate the proportion of patients who achieved a PASS 12 to 24 months after hip arthroscopy and to determine the cutoff scores of the 2 recommended and valid patient-reported outcome measures (the subscales of the Copenhagen Hip and Groin Outcome Score [HAGOS] and the International Hip Outcome Tool-33 [iHOT-33]) for which patients are most likely to achieve PASS.

Study Design

Cohort study; Level of evidence, 3.

Methods

Eligible study patients were identified in the Danish Hip Arthroscopy Registry. An electronic questionnaire was used to collect data on PASS, HAGOS, and iHOT-33 12 to 24 months after surgery. PASS was measured using an anchor question. Receiver operating characteristic curve analyses were applied to identify the PASS cutoff values of HAGOS and iHOT-33 scores.

Results

A total of 137 individuals (mean age at surgery, 35.4 ± 9.4 years) were included in the study at a mean follow-up of 18.5 ± 3.2 months after surgery. At follow-up, 64 individuals (46.7%; 95% CI, 38.6-55.1) reported PASS. Higher HAGOS and iHOT-33 values were observed for participants who reported PASS compared with those who did not report PASS (Cohen d ≥ 1.06; P < .001). Cutoff scores for HAGOS subscales (42.5-82.5) and iHOT-33 (67.00) showed excellent to outstanding discriminative ability in predicting PASS (area under the curve, 0.82-0.92).

Conclusion

In total, 46% of individuals having hip arthroscopy for FAIS achieved PASS at 12 to 24 months of follow-up. Patients who achieved PASS had statistically significant and substantially better self-reported hip function compared with those who did not achieve PASS. Cutoff values at HAGOS subscales and iHOT-33 showed excellent to outstanding discriminative ability in predicting patients with PASS.

Physiotherapist-led treatment for femoroacetabular impingement syndrome (the PhysioFIRST study): a protocol for a participant and assessor-blinded randomised controlled trial

INTRODUCTION

This double-blind, randomised controlled trial (RCT) aims to estimate the effect of a physiotherapist-led intervention with targeted strengthening compared with a physiotherapist-led intervention with standardised stretching, on hip-related quality of life (QOL) or perceived improvement at 6 months in people with femoroacetabular impingement (FAI) syndrome. We hypothesise that at 6 months, targeted strengthening physiotherapist-led treatment will be associated with greater improvements in hip-related QOL or greater patient-perceived global improvement when compared with standardised stretching physiotherapist-led treatment.

METHODS AND ANALYSIS

We will recruit 164 participants with FAI syndrome who will be randomised into one of the two intervention groups, both receiving one-on-one treatment with the physiotherapist over 6 months. The targeted strengthening physiotherapist-led treatment group will receive a personalised exercise therapy and education programme. The standardised stretching physiotherapist-led treatment group will receive standardised stretching and personalised education programme. Primary outcomes are change in hip-related QOL using International Hip Outcome Tool-33 and patient-perceived global improvement. Secondary outcomes include cost-effectiveness, muscle strength, range of motion, functional task performance, biomechanics, hip cartilage structure and physical activity levels. Statistical analyses will make comparisons between both treatment groups by intention to treat, with all randomised participants included in analyses, regardless of protocol adherence. Linear mixed models (with baseline value as a covariate and treatment condition as a fixed factor) will be used to evaluate the treatment effect and 95% CI at primary end-point (6 months).

ETHICS AND DISSEMINATION

The study protocol was approved (La Trobe University Human Ethics Committee (HEC17-080)) and prospectively registered with the Australian New Zealand Clinical Trials Registry. The findings of this RCT will be disseminated through peer reviewed scientific journals and conferences. Patients were involved in study development and will receive a short summary following the completion of the RCT.

TRIAL REGISTRATION NUMBER

ACTRN12617001350314.

Femoroacetabular Impingement and Core Muscle Injury in Athletes: Diagnosis and Algorithms for Success

Athletic hip injuries account for a substantial portion of missed time from sports in high-level athletes. For both femoroacetabular impingement (FAI) and core muscles injuries, a thorough history and physical examination are paramount to guide the treatment. While advanced imaging including computed tomography and magnetic resonance imaging are frequently obtained, a wealth of information can be ascertained from standard radiographs alone. For patients with isolated or combined FAI and core muscle injuries (CMIs), the initial treatment is often nonoperative and consists of rest, activity modification, and physical therapy of the hips, core, and trunk. Injections may then aid in both confirming diagnosis and temporary symptom abatement. Arthroscopic procedures for refractory FAI in experienced hands have been shown to be both safe and efficacious. While surgical repair options for CMIs are significantly more variable, long-term studies have demonstrated the rapid resolution of symptoms and high return to play rates. More recently, anatomic and clinical correlations between FAI and CMIs have been identified. Special attention must be paid to elite athletes as the incidence of concurrent FAI with CMI is extremely high yet with significant symptom variability. Predictable return to play in athletes with coexisting symptomatic intra-articular and extra-articular symptomatology is incumbent upon the treatment of both pathologies.

The Use of Biologics for Hip Preservation

PURPOSE OF REVIEW

A wide array of nonoperative modalities to treat hip pain are aimed at restoring and maintaining the structural and physiologic characteristics of the joint. The purpose of this review is to describe the current understanding of biologics in hip pathology by providing an evidence-based overview of treatment modalities available for orthopedic surgeons.

RECENT FINDINGS

The use of biologics as a primary treatment or adjunct to traditional management has shown encouraging results for the treatment of hip pain. Studies have demonstrated safety with minimal complications when using platelet rich plasma, hyaluronic acid, or stem cells to treat hip pain caused by osteoarthritis, femoroacetabular impingement syndrome, tendinopathy, or osteonecrosis of the femoral head. Several studies have been able to demonstrate meaningful clinical results that can improve treatment standards for hip pain; however, more work must be performed to better delineate the appropriate protocols, indications, and limitations of each modality. Recent advances have inspired renewed interest in biologics for patients with hip pain. We present a concise review of platelet rich plasma, hyaluronic acid, stem cells, and matrix metalloprotease inhibitors and their applicability to hip preservation surgery.

Clinical outcomes after revision hip arthroscopy in patients with femoroacetabular impingement syndrome (FAIS) are inferior compared to primary procedures. Results from the Danish Hip Arthroscopy Registry (DHAR)

PURPOSE

As many as 10% of primary hip arthroscopies end up with a revision arthroscopy procedure when treating patients suffering from femoroacetabular impingement syndrome (FAIS). In general, revision procedures are indicated because of residual impingement, but only a few studies present outcome data from revision hip arthroscopy after failed FAIS surgical treatment. The purpose of this study was to evaluate clinical outcomes after revision hip arthroscopy in a FAIS cohort and compare outcomes with a primary FAIS hip arthroscopy cohort and describe potential causes of failure after the primary hip arthroscopy. It was hypothesized that subjective outcomes improve after revision hip arthroscopy although outcomes were expected to be inferior to primary hip arthroscopic outcomes.

METHODS

Three-hundred and thirty-one arthroscopic revision hip FAIS patients were included from the Danish Hip Arthroscopy Registry (DHAR). Patient-related outcome measures (PROM's), Copenhagen Hip and Groin Outcome Scores (HAGOS), Hip Sports Activity Scale (HSAS), EQ-5D and Numeric Rating Scale (NRS) pain, were assessed in the study cohort prior to the primary procedure and at revision and at follow-up one year after the revision procedure. These data were compared with 4154 primary hip arthroscopic FAIS patients.

RESULTS

One-year after revision surgery, mean follow-up (in months ± SD): 12.3 ± 1.6, significant improvements (p < 0.05) in all PROMs was demonstrated, but FAIS patients in the primary hip arthroscopic cohort demonstrated significantly higher outcomes, in all PROMs, when compared at one-year follow-up. Scar tissue, residual osseous impingement and insufficient healing of the labral repair were reported as the main reasons for revision surgery. The conversion to total hip arthroplasty was low (6.4%).

CONCLUSION

Revision hip arthroscopy in FAIS patients improves subjective outcomes significantly, although they are poorer than after primary FAIS hip arthroscopy. Main reasons for revision arthroscopy was scar tissue, residual femoroacetabular impingement and insufficient healing of labral repair.

LEVEL OF EVIDENCE

Level III.

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.

Patient experiences of receiving arthroscopic surgery or personalised hip therapy for femoroacetabular impingement in the context of the UK fashion study: a qualitative study

BACKGROUND

UK FASHIoN was a multicentre randomised controlled trial comparing hip arthroscopic surgery (HA) with personalised hip therapy (PHT, physiotherapist-led conservative care), for patients with hip pain attributed to femoroacetabular impingement (FAI) syndrome. Our aim was to describe the treatment and trial participation experiences of patients, to contextualise the trial results and offer further information to assist treatment decision-making in FAI.

METHODS

We conducted in-depth semi-structured telephone interviews with a purposive sample of trial participants from each of the trial arms. They were interviewed after they received treatment and completed their first year of trial participation. Thematic analysis and constant comparison analytical approaches were used to identify themes of patient treatment experiences during the trial.

RESULTS

Forty trial participants were interviewed in this qualitative study. Their baseline characteristics were similar to those in the main trial sample. On average, their hip-related quality of life (iHOT-33 scores) at 12 months follow-up were lower than average for all trial participants, indicating poorer hip-related quality of life as a consequence of theoretical sampling. Patient experiences occurred in five patient groups: those who felt their symptoms improved with hip arthroscopy, or with personal hip therapy, patients who felt their hip symptoms did not change with PHT but did not want HA, patients who decided to change from PHT to HA and a group who experienced serious complications after HA. Interviewees mostly described a trouble-free, enriching and altruistic trial participation experience, although most participants expected more clinical follow-up at the end of the trial.

CONCLUSION

Both HA and PHT were experienced as beneficial by participants in the trial. Treatment success appeared to depend partly on patients' prior own expectations as well as their outcomes, and future research is needed to explore this further. Findings from this study can be combined with the primary results to inform future FAI patients.

TRIAL REGISTRATION

Arthroscopic surgery for hip impingement versus best conventional care ( ISRCTN64081839 ). 28/02/2014.

Deriving alpha angle from anterior-posterior dual-energy x-ray absorptiometry scans: an automated and validated approach

Introduction: Alpha angle (AA) is a widely used measure of hip shape that is commonly used to define cam morphology, a bulging of the lateral aspect of the femoral head. Cam morphology has shown strong associations with hip osteoarthritis (OA) making the AA a clinically relevant measure. In both clinical practice and research studies, AA tends to be measured manually which can be inconsistent and time-consuming. Objective: We aimed to (i) develop an automated method of deriving AA from anterior-posterior dual-energy x-ray absorptiometry (DXA) scans; and (ii) validate this method against manual measures of AA. Methods: 6,807 individuals with left hip DXAs were selected from UK Biobank. Outline points were manually placed around the femoral head on 1,930 images before training a Random Forest-based algorithm to place the points on a further 4,877 images. An automatic method for calculating AA was written in Python 3 utilising these outline points. An iterative approach was taken to developing and validating the method, testing the automated measures against independent batches of manually measured images in sequential experiments. Results: Over the course of six experimental stages the concordance correlation coefficient, when comparing the automatic AA to manual measures of AA, improved from 0.28 [95% confidence interval 0.13-0.43] for the initial version to 0.88 [0.84-0.92] for the final version. The inter-rater kappa statistic comparing automatic versus manual measures of cam morphology, defined as AA ³≥60°, improved from 0.43 [80% agreement] for the initial version to 0.86 [94% agreement] for the final version. Conclusions: We have developed and validated an automated measure of AA from DXA scans, showing high agreement with manually measuring AA. The proposed method is available to the wider research community from Zenodo.

Cost-Effectiveness of Hip Arthroscopy for Treatment of Femoroacetabular Impingement Syndrome and Labral Tears: A Systematic Review

Background:

Hip arthroscopy has frequently been shown to produce successful outcomes as a treatment for femoroacetabular impingement (FAI) and labral tears. However, there is less literature on whether the favorable results of hip arthroscopy can justify the costs, especially when compared with a nonoperative treatment.

Purpose:

To systematically review the cost-effectiveness of hip arthroscopy for treating FAI and labral tears.

Study Design:

Systematic review; Level of evidence, 3.

Methods:

PubMed/MEDLINE, Embase, and Cochrane Library databases, and the Tufts University Cost-Effectiveness Analysis Registry were searched to identify articles that reported the cost per quality-adjusted life-year (QALY) generated by hip arthroscopy. The key terms used were “hip arthroscopy,” “cost,” “utility,” and “economic evaluation.” The threshold for cost-effectiveness was set at $50,000/QALY. The Methodological Index for Non-Randomized Studies instrument and Quality of Health Economic Studies (QHES) score were used to determine the quality of the studies. This study was prospectively registered on PROSPERO (CRD42020172991).

Results:

Six studies that reported the cost-effectiveness of hip arthroscopy were identified, and 5 of these studies compared hip arthroscopy to a nonoperative comparator. These studies were found to have a mean QHES score of 85.2 and a mean cohort age that ranged from 33-37 years. From both a health care system perspective and a societal perspective, 4 studies reported that hip arthroscopy was more costly but resulted in far greater gains than did nonoperative treatment. The preferred treatment strategy was most sensitive to duration of benefit, preoperative osteoarthritis, cost of the arthroscopy, and the improvement in QALYs with hip arthroscopy.

Conclusion:

In the majority of the studies, hip arthroscopy had a higher initial cost but provided greater gain in QALYs than did a nonoperative treatment. In certain cases, hip arthroscopy can be cost-effective given a long enough duration of benefit and appropriate patient selection. However, there is further need for literature to analyze willingness-to-pay thresholds.

Arthroscopic Correction of Sports-Related Femoroacetabular Impingement in Competitive Athletes: 2-Year Clinical Outcome and Predictors for Achieving Minimal Clinically Important Difference

Background:

A growing body of literature supports surgical intervention for femoroacetabular impingement (FAI) in young, active athletes. However, factors likely to influence results in this cohort are less clearly defined.

Purpose:

To quantify changes in validated patient-reported outcome measures (PROMs) and determine whether differences in baseline athlete demographic characteristics, intraoperative findings, and surgical techniques are associated with achieving improved outcomes and minimal clinically important difference (MCID) after arthroscopic management of sports-related FAI.

Study Design:

Case series; Level of evidence, 4.

Methods:

Data were prospectively collected from competitive athletes who underwent hip arthroscopy between January 2009 and February 2017. Athletes who underwent primary arthroscopic correction of sports-related FAI with labral repair were included providing they had a Tönnis grade ≤1 and a lateral center-edge angle ≥20°, excluding significant articular cartilage injury and lateral rim dysplasia. The modified Harris Hip Score, Western Ontario and McMaster Universities Osteoarthritis Index, University of California Los Angeles activity scale, and 36-Item Short Form Health Survey were used to measure outcomes at the 2-year follow-up. MCID was measured using 3 methods: a mean change method, a distribution-based method, and the percentage of possible improvement (POPI) method. Multivariate regression models were used to assess a number of diagnostic and surgical variables associated with good outcome and achieving MCID at follow-up.

Results:

At 2-year follow-up, statistically significant improvements were observed for all PROMs (P < .001 for all), and 84% of athletes continued to play sport. Higher preoperative PROM scores reduced the likelihood of achieving MCID; however, returning to play was the strongest predictor of reaching MCID in this athletic cohort. Using absolute score change (mean change or distribution method) to calculate MCID was less accurate owing to ceiling effects and dependence on preoperative PROM scores.

Conclusion:

Athletes undergoing arthroscopy for sports-related FAI can expect a successful outcome and continued sports participation at 2 years postoperatively. The majority of athletes will achieve MCID. The POPI method of MCID calculation was more applicable to higher functioning athletic cohorts. Reduced preoperative PROM scores and the ability to return to sport increased the likelihood of achieving MCID in this population.

The Role of Hip Joint Clearance Discrepancy as Other Clinical Predictor of Reinjury and Injury Severity in Hamstring Tears in Elite Athletes

Hamstring tear injuries (HTI) are the most prevalent injuries in athletes, with high reinjury rates. To prevent reinjury and reduce the severity of injuries, it is essential to identify potential risk factors. Hip characteristics are fundamental to optimal hamstring function. We sought to investigate the role of hip joint clearance discrepancy (JCD) as a risk factor for HTI and a clinical predictor of risk of reinjury and injury severity. A cross-sectional, retrospective study was performed with elite athletes (n = 100) who did (n = 50) and did not (n = 50) have a history of injury. X-rays were taken to assess JCD. We reviewed muscular lesions historial, and health records for the previous 5 years. Significant differences were found in injury severity (p = 0.026; ŋ²p = 0.105) and a number of injuries (p = 0.003; ŋ²p = 0.172). The multivariate analysis data indicated that JCD was significantly associated with the number of injuries and their severity (p < 0.05). In the stepwise regression model, JCD variability explained 60.1% of the number of injuries (R² 0.601) and 10.5% of injury severity (R² 0.0105). These results suggest that JCD could play an important role as a risk factor for HTI and also as a clinical predictor of reinjury and injury severity.

The Size and Prevalence of Bony Hip Morphology Do Not Differ Between Football Players With and Without Hip and/or Groin Pain: Findings From the FORCe Cohort

OBJECTIVE

To compare the size and prevalence of bony hip morphology in football players with and without hip and/or groin pain.

DESIGN

Case-control.

METHODS

We recruited 184 soccer and Australian football players with self-reported hip and/or groin pain of greater than 6 months in duration and a positive flexion, adduction, and internal rotation (FADIR) test (290 hips, 21% women), and 55 football players with no pain and a negative FADIR test (110 hips, 26% women) as a control group. Bony hip morphology was identified by the alpha angle and lateral center-edge angle (LCEA) on anteroposterior pelvis and Dunn 45° radiographs. The alpha angle and LCEA were analyzed as continuous measures (size) and dichotomized using threshold values to determine the presence of bony hip morphology (cam, large cam, pincer, and acetabular dysplasia). Regression analyses estimated differences in the size and prevalence of bony hip morphology between football players with and without pain.

RESULTS

In all football players and in men, the size and prevalence of bony hip morphology did not differ between those with and without hip and/or groin pain. Cam morphology was evident in 63% of hips in players without pain and 71% of symptomatic hips in players with hip and/or groin pain. In female football players with hip and/or groin pain compared to those without pain, larger alpha angle values were observed on the Dunn 45° view (5.9°; 95% confidence interval: 1.2°, 10.6°; P = .014).

CONCLUSION

The size and prevalence of bony hip morphology appear to be similar in football players with and without hip and/or groin pain. J Orthop Sports Phys Ther 2021;51(3):115-125. Epub 25 Dec 2020. doi:10.2519/jospt.2021.9622.

Defining the Clinically Meaningful Outcomes for Arthroscopic Treatment of Femoroacetabular Impingement Syndrome at Minimum 10-Year Follow-up: The Timing of Surgery Is Crucial

Background

Arthroscopic treatment of femoroacetabular impingement syndrome (FAIS) has become a common procedure. However, meaningful long-term clinical outcomes have not been defined.

Purpose

To define the minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS) for the modified Harris Hip Score (mHHS) at a minimum 10-year follow-up in patients undergoing arthroscopic treatment for FAIS and identify preoperative predictors for achievement of the MCID, SCB, and PASS.

Study Design

Case-control study; Level of evidence, 3.

Methods

A consecutive series of patients undergoing arthroscopic treatment for FAIS between 2007 and 2009 with a minimum 10-year follow-up was analyzed. Patient data included patient characteristics, radiographic parameters, and the pre- and postoperative mHHS and visual analog scale (VAS) for pain score. Paired t tests were used to compare the patient-reported outcome measures (PROMs). The MCID was determined by calculating half of the standard deviation, and SCB and PASS were calculated by the anchor method. Correlation and logistic regression analyses were conducted to identify predictors for the achievement of the MCID, SCB, and PASS.

Results

A total of 44 patients (27 men, 17 women) were included. The mean age and body mass index were 42.2 years (range, 16-67 years) and 22.3 kg/m² (range, 16.76-29.78 kg/m²), respectively. The MCID, absolute SCB, net change SCB, and PASS of the mHHS were calculated to be 19.6, 90.1, 31.5, and 84.4 points, respectively. Preoperative symptom duration was identified as an independent predictor for the achievement of meaningful clinical outcomes. The median symptom durations for patients who achieved the MCID, absolute SCB, net change SCB, and PASS were 11.7, 9.1, 9.0, and 10.8 months, respectively. The median symptom duration for patients who did not achieve the MCID, absolute SCB, net change SCB, and PASS were 15.8, 17.4, 17.3, and 18.4 months, respectively. No other statistically significant correlations were found.

Conclusion

The preoperative duration of symptoms was identified as an independent predictor for achievement of the MCID, SCB, and PASS. These findings can be helpful in accelerating the transition to surgical treatment of FAIS.

Outside-In Capsulotomy of the Hip for Arthroscopic Pincer Resection

Hip surgical techniques have evolved significantly, transitioning from open techniques to arthroscopic techniques. Hip arthroscopy has many advantages over open techniques, including reduced trauma to surrounding tissues, reduced risk of infection, and improved patient-reported outcome measures. Hip arthroscopic techniques are now commonly used for pathologies such as femoroacetabular impingement (FAI). FAI can include cam, pincer, or mixed impingement. Through hip arthroscopy, FAI may be treated with a femoroplasty and acetabuloplasty along with addressing any labral pathology that may exist. Owing to the capsule playing an integral role in hip stability, surgeons are now mindful of the initial approach and closure on completion of the intra-articular procedure. The most common approach for capsulotomy is the inside-out approach. However, this approach can be difficult in patients with a large pincer deformity. The authors describe an outside-in approach to arthroscopic hip capsulotomy. This capsular approach helps protect the labrum and articular cartilage while preserving capsular tissue.

Treatment of Labral Calcification in the Setting of Femoroacetabular Impingement Syndrome With Arthroscopic Calcification Excision, Labral Repair, and Osteoplasty Improves Outcomes

PURPOSE

To describe the diagnosis and 2-year outcomes of arthroscopic treatment for labral calcification in the setting of femoroacetabular impingement syndrome (FAIS).

METHODS

A retrospective analysis was performed from a prospectively collected database of patients with FAIS undergoing hip arthroscopy. Patients with FAIS with labral calcification were differentiated radiographically from patients with other paralabral radiopaque densities such as os acetabuli, acetabular rim fractures, and labral ossification. Patients with FAIS with labral calcification were treated with arthroscopic calcification excision, labral repair, and osteoplasty and matched by age, sex, and body mass index with a cohort of patients with FAIS without labral calcifications who underwent labral repair and osteoplasty. Pre- and 2 years postoperatively, patients completed patient-reported outcome (PRO) scores including the modified Harris Hip Score, Hip disability and Osteoarthritis Outcome Score (HOOS), 12-item Short-Form survey, and visual analog scale.

RESULTS

In total, 40 hips (21 male, 19 female) with FAIS and labral calcification were included (age 36.8 ± 8.1, body mass index, 25.9 ± 4.5). Patients with FAIS with labral calcification demonstrated similar significant PRO score improvements compared with a matched cohort of patients with FAIS without labral calcification at 2 years after surgery (visual analog scale: (-)2.3 ± 0.4, (-)2.7 ± 0.5, modified Harris Hip Score: 16.1 ± 2.6, 17.1 ± 3.2; HOOS symptoms: 21.9 ± 3.7, 18.6 ± 3.6; HOOS pain: 22.1 ± 3.0, 25.0 ± 3.5; HOOS activities of daily living: 20.2 ± 2.8, 23.8 ± 3.3; HOOS sport: 35.6 ± 5.0, 35.6 ± 4.1; HOOS quality of life: 36.9 ± 4.5, 37.5 ± 4.4; 12-item Short-Form survey physical component summary: 15.5 ± 2.3, 20.1 ± 2.1, respectively). Both cohorts achieved minimal clinically important differences at equivalent rates (60%-82.5%) for all PRO scores.

CONCLUSIONS

Patients with labral calcification in the setting of FAIS can be effectively treated with arthroscopic calcification excision, labral repair, and osteoplasty. These patients demonstrate significant improvements in patient-reported outcomes and achievement of minimal clinically important differences at 2 years similar to patients undergoing arthroscopic treatment for FAIS without labral calcification.

LEVEL OF EVIDENCE

Level III, matched cohort study.

Midterm Outcomes and Satisfaction After Hip Arthroscopy Are Associated With Postoperative Rehabilitation Factors

Background:

Arthroscopic hip-preservation surgery is commonly performed to address nonarthritic sources of hip pain in young, active individuals. However, there is little evidence to support postoperative rehabilitation protocols, including the most appropriate frequency and length of individual formal physical therapy sessions. There is also a lack of information to look at patients’ perceived value of their home program/self-practice in relation to outcomes.

Purpose:

To investigate postoperative rehabilitation factors after hip arthroscopy related to formal physical therapy and home program/self-practice and their correlation with patient outcomes and satisfaction.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

A total of 125 patients who underwent hip arthroscopy for femoroacetabular impingement syndrome and a labral tear (75 men) were included. The mean age was 34.6 ± 14.4 years, and the mean follow-up time was 4.9 ± 1.6 years. Hip Outcome Score–Activities of Daily Living subscale (HOS-ADL) scores, overall satisfaction scores, and factors related to supervised physical therapy and home program/self-practice were collected. Correlations between continuous variables and differences in the length of individual formal physical therapy and patients’ rating of the importance of their home program/self-practice between those who would and those who would not undergo surgery again were assessed.

Results:

The frequency and length of individual formal physical therapy sessions were significantly correlated with postoperative HOS-ADL scores (r = 0.22, P = .014; and r = 0.24, P = .007, respectively) and level of satisfaction (r = 0.24, P = .007; and r = 0.21, P = .02, respectively). The length of individual formal physical therapy sessions was significantly greater in those who noted they would undergo surgery again (35.3 vs 26.3; P = .033). A significant correlation was identified between the rating of the importance of their home program/self-practice and postoperative HOS-ADL scores (r = 0.29; P = .001) and their level of satisfaction (r = 0.23; P = .009). There was a significant difference in the rating of the importance of their home program/self-practice between those who would undergo surgery again and those who would not (8.9 vs 7.8; P = .007).

Conclusion:

Surgeons and physical therapists should emphasize the value of home program/self-practice when it comes to outcomes and may want to encourage their patients to participate in more frequent, longer, formal physical therapy sessions.

Hip joint space width in an asymptomatic population: Computed tomography analysis according to femoroacetabular impingement morphologies

Background

Although the association between femoroacetabular impingement (FAI) syndrome and hip osteoarthritis (OA) is well established, not all hips exhibiting cam or pincer morphologies (i.e. imaging findings of FAI syndrome) are symptomatic or arthritic. It is difficult to detect which subgroup will wear out, or how does the arthritic process start radiographically. Therefore, we measured in a retrospective study based on computed tomography (CT) analysis, the joint space width (JSW) according to a standard protocol and we investigated its variation according to the presence of a cam and/or pincer morphology. We hypothesized that the radiological presence of a cam and/or pincer hip morphologies, even in asymptomatic subjects, would affect JSW.

Methods

Two hundred pelvic CT scans performed for non-orthopedic etiologies in asymptomatic patients were analyzed using a 3D software. After excluding patients with hip OA or previous hip surgery, 194 pelvic CT scans (388 hips) were retained. We measured for each hip the presence of FAI syndrome imaging findings (cam and pincer morphologies) using the classical parameters of coxometry. In addition, we performed a measurement of articular joint space width according to a standard protocol. We then calculated the mean thickness of 3 defined regions along the femoroacetabular joint: anterior-superior, posterior-inferior, and posterior-superior. Lastly, we compared the JSW across 4 groups: hips with (1) no cam or pincer, (2) pincer, (3) cam, and (4) cam and pincer morphologies using a multivariate analysis. Additionally, a topographic heatmap of JSW was plotted allowing quantitative representation of JSW along the joint.

Results

Increased JSW with peak difference of 0.9 mm (25.7%) was found in hips with cam and pincer morphologies when compared to normal ones (p = 0.002) and to hips with pincer or cam morphologies only.

Conclusion

Positive variations in JSW were associated to the presence of cam and pincer morphologies. This significant increase in JSW could be one of the earliest measurable changes preceding later classical alterations.

Best Practices: Hip Femoroacetabular Impingement

OBJECTIVE. Imaging plays a critical role in the assessment of patients with femoroacetabular impingement (FAI). With better understanding of the underlying pathomechanics and advances in joint-preserving surgery, there is an increasing need to define the most appropriate imaging workup. The purpose of this article is to provide guidance on best practices for imaging of patients with FAI in light of recent advances in corrective FAI surgery. CONCLUSION. Pelvic radiography with dedicated hip projections is the basis of the diagnostic workup of patients with suspected FAI to assess arthritic changes and acetabular coverage and to screen for cam deformities. Chondrolabral lesions should be evaluated with unenhanced MRI or MR arthrography. The protocol should include a large-FOV fluid-sensitive sequence to exclude conditions that can mimic or coexist with FAI, radial imaging to accurately determine the presence of a cam deformity, and imaging of the distal femoral condyles for measurement of femoral torsion. CT remains a valuable tool for planning of complex surgical corrections. Advanced imaging, such as 3D simulation, biochemical MRI, and MR arthrography with application of leg traction, has great potential to improve surgical decision-making. Further research is needed to assess the added clinical value of these techniques.

Hip Dysplasia

Acetabular dysplasia represents a structural pathomorphology associated with hip pain, instability, and osteoarthritis. The wide spectrum of dysplasia anatomically refers to a 3-dimensional volumetric- and surface area-based insufficiency in coverage and is classified based on the magnitude and location of undercoverage. Borderline dysplasia has been variably defined and leads to management challenges. In symptomatic dysplasia, treatment addresses coverage with periacetabular osteotomy. Concomitant simultaneous or staged hip arthroscopy has significant advantages to address intra-articular pathology. In nonarthritic individuals, there is evidence PAO alters the natural history of dysplasia and decreases the risk of hip arthritis and total hip arthroplasty.

The Lisbon Agreement on femoroacetabular impingement imaging-part 2: general issues, parameters, and reporting

OBJECTIVES

Imaging assessment for the clinical management of femoroacetabular impingement (FAI) is controversial because of a paucity of evidence-based guidance and notable variability among practitioners. Hence, expert consensus is needed because standardised imaging assessment is critical for clinical practice and research. We aimed to establish expert-based statements on FAI imaging by using formal methods of consensus building.

METHODS

The Delphi method was used to formally derive consensus among 30 panel members from 13 countries. Forty-four questions were agreed upon, and relevant seminal literature was circulated and classified in major topics to produce answering statements. The level of evidence was noted for all statements, and panel members were asked to score their level of agreement (0-10). This is the second part of a three-part consensus series and focuses on 'General issues' and 'Parameters and reporting'.

RESULTS

Forty-seven statements were generated and group consensus was reached for 45. Twenty-five statements pertaining to 'General issues' (9 addressing diagnosis, differential diagnosis, and postoperative imaging) and 'Parameters and reporting' (16 addressing femoral/acetabular parameters) were produced.

CONCLUSIONS

The available evidence was reviewed critically, recommended criteria for diagnostic imaging highlighted, and the roles/values of different imaging parameters assessed. Radiographic evaluation (AP pelvis and a Dunn 45° view) is the cornerstone of hip-imaging assessment and the minimum imaging study that should be performed when evaluating adult patients for FAI. In most cases, cross-sectional imaging is warranted because MRI is the 'gold standard' imaging modality for the comprehensive evaluation, differential diagnosis assessment, and FAI surgical planning.

KEY POINTS

• Diagnostic imaging for FAI is not standardised due to scarce evidence-based guidance on which imaging modalities and diagnostic criteria/parameters should be used. • Radiographic evaluation is the cornerstone of hip assessment and the minimum study that should be performed when assessing suspected FAI. Cross-sectional imaging is justified in most cases because MRI is the 'gold standard' modality for comprehensive FAI evaluation. • For acetabular morphology, coverage (Wiberg's angle and acetabular index) and version (crossover, posterior wall, and ischial spine signs) should be assessed routinely. On the femoral side, the head-neck junction morphology (α° and offset), neck morphology (NSA), and torsion should be assessed.

Do currently prescribed exercises reflect contributing pathomechanics associated with femoroacetabular impingement syndrome? A scoping review

OBJECTIVE

Research reports limited, mixed evidence on the effectiveness of physiotherapy management in the treatment of femoroacetabular impingement (FAI) syndrome. The purpose of this review was to (1) identify what therapeutic exercises are being utilized in the non-surgical management of patients with FAI syndrome; (2) map the extent to which reported exercises reflect contributory pathomechanics associated with FAI syndrome.

DESIGN

Scoping Review.

METHODS

MEDLINE, PubMed, CINAHL, SPORTDiscus, and PEDRO electronic databases were searched for studies that implemented a non-surgical, exercise-based treatment approach in patients with FAI syndrome. Exercises were extracted and analyzed according to elements recognized as contributing to the pathomechanics associated with FAI syndrome.

RESULTS

24 studies fulfilled the inclusion criteria. 453 exercises were extracted. Uniplanar exercises accounted for 338/453 or 74.6% of all reported exercises whereas triplanar exercises accounted for 21/453 or 4.6% of all exercises. Non-weight bearing exercises accounted for 220/453 or 48.6% of all exercises.

CONCLUSION

The majority of therapeutic exercises were classified as sagittal, uniplanar exercises, utilizing a concentric exercise approach. These findings highlight that exercises utilizing triplanar, eccentric hip control, in a single limb weightbearing position are considerably underrepresented.

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).

Less hip range of motion is associated with a greater alpha angle in people with longstanding hip and groin pain

PURPOSE

A higher alpha angle has been proposed to correlate with lower hip range of motion, but the association in people with longstanding hip and groin pain is currently unclear. The aims were to: (1) assess the association between range of motion and alpha angle in patients with longstanding hip and groin pain; (2) examine if a cut-off value in range of motion variables could identify patients with an alpha angle above or below 60°.

METHODS

Seventy-two participants were consecutively recruited from an orthopaedic department after referral for hip- and groin-related pain. Passive hip range of motion was measured in flexion, internal rotation with 90° hip flexion, internal rotation in neutral hip position, external rotation with 90° hip flexion, and abduction. The alpha angle was calculated from a frog-leg lateral radiograph. Linear regression examined the association between range of motion and alpha angle, and an ROC-curve analysis was performed to identify the sensitivity and specificity of range of motion cut-offs.

RESULTS

Lower range of motion in internal rotation in flexion, external rotation, and abduction were associated with higher alpha angle. Internal rotation of 27° or less displayed good sensitivity (81%) and specificity (85%) to detect an alpha angle above 60°, while a cut-off of 41° in external rotation and 27° in abduction showed a sensitivity of 72% and specificity of 50% and 60%, respectively.

CONCLUSION

Less internal rotation in flexion, external rotation, and abduction are associated with a greater alpha angle in a cohort of people with longstanding hip and groin pain. A cut-off of 27° in internal rotation has good sensitivity and specificity to identify people with an alpha angle above or below 60° and have the potential to be used in the clinical setting to identify patients that require further imaging, or that are unlikely to have cam morphology.

LEVEL OF EVIDENCE

II.

Incidence of Femoroacetabular Impingement and Surgical Management Trends Over Time

BACKGROUND

Femoroacetabular impingement (FAI) is a well-known cause of hip pain in adolescents and young adults. However, the incidence in the general population has not been clearly defined.

PURPOSE

To (1) define the population-based incidence of diagnosis of FAI in patients with hip pain, (2) report the trends in diagnosis of FAI over time, and (3) determine the changes in the rate and type of surgical management over time.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A geographic database was used to identify patients who were 14 to 50 years old with hip pain between the years 2000 and 2016. Chart and radiographic review was performed to determine which patients had FAI. To be included, patients had to have a triad of clinical symptoms, physical examination signs, and imaging findings consistent with FAI. Medical records were reviewed to obtain demographic information, clinical history, physical examination findings, imaging details, and treatment details. Statistical analysis determined the overall age- and sex-adjusted annual incidence of FAI diagnosis and trends over time.

RESULTS

There were 1893 patients evaluated with hip pain, and 716 (38%; 813 hips) had diagnosed FAI. The mean ± SD age was 27.2 ± 8.4 years, and 67% were female. The incidence of FAI diagnosis was 54.4 per 100,000 person-years. Female patients had a higher incidence than male patients (73.2 vs 36.1 per 100,000 person-years; P < .01). Incidence of FAI diagnosis were higher from 2010 to 2016 (72.6 per 100,000 person-years; P < .01) as compared with 2005 to 2009 (45.3) and 2000 to 2004 (40.3). Hip arthroscopy, surgical hip dislocation, and periacetabular osteotomy utilization increased from the 2000-2004 to 2010-2016 periods, respectively: 1 (1%) to 160 (20%; P = .04), 2 (1%) to 37 (5%; P = .01), and 1 (1%) to 22 (3%; P = .58).

CONCLUSION

The overall incidence of FAI diagnosis was 54.4 per 100,000 person-years, and it consistently increased between 2000 and 2016. Female patients had a higher incidence than male patients. The utilization of joint preservation operations, including hip arthroscopy, surgical hip dislocation, and anteverting periacetabular osteotomy, increased over time.

The Influence of Body Mass Index on Outcomes After Hip Arthroscopy for Femoroacetabular Impingement Syndrome: Five-Year Results in 140 Patients

BACKGROUND

Significant short-term improvements in function and pain after arthroscopic management of femoroacetabular impingement syndrome (FAIS) have been demonstrated regardless of mass index (BMI). No studies have reported the influence of obesity on mid- to long-term outcomes.

PURPOSE

To evaluate the effect of BMI class on 5-year patient outcomes after arthroscopic treatment of FAIS.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A retrospective review of a prospective database was performed to identify patients who underwent arthroscopic treatment for FAIS. A matched-pair analysis for age and sex was performed in a 1:1:2:3 fashion for morbidly obese (BMI ≥35), obese (BMI = 30-34.9), overweight (BMI = 25-29.9), and normal weight (BMI = 18.5-24.9) patients, respectively. Patient characteristics, imaging, Hip Outcome Score Activities of Daily Living (HOS-ADL) and Sports Subscale (HOS-SS) scores, modified Harris Hip Score (mHHS), and pain scores were recorded preoperatively, with the same outcome scores recorded at 5 years postoperatively, along with satisfaction scores. Standardized modern hip arthroscopy, with labral repair, acetabuloplasty, femoroplasty, and capsular plication followed by formalized rehabilitation, was performed for all patients. Absolute outcomes along with change in outcomes were assessed between BMI groups. A between-group analysis was also conducted evaluating achievement of the minimal clinically important difference (MCID), patient acceptable symptomatic state (PASS), and substantial clinical benefit (SCB) for any outcome score. A multivariable analysis was additionally included to evaluate outcomes adjusting for known confounding variables.

RESULTS

A total of 140 patients with mean follow-up of 62.1 ± 6.5 months were identified: 20 morbidly obese, 20 obese, 40 overweight, and 60 normal weight. There were significant improvements for HOS-ADL, HOS-SS, and mHHS scores in the normal (all P < .0001) and overweight groups (all P < .0001), mHHS in the obese group (P = .0275), and no significant improvement in functional scores in the morbidly obese group (P > .05). Compared with normal controls, multivariable analysis, adjusting for confounders, showed similar improvement in HOS-ADL for patients in the overweight and obese groups, HOS-SS for patients in the overweight group, and mHHS for patients in the overweight and obese groups (all P > .05). All groups showed significant improvement in pain scores (all P < .01) that were not significantly different between groups in multivariable analysis (all P > .05). Obese BMI was associated with a 54.9-point decrease in 5-year HOS-SS, and morbidly obese BMI was associated with a 27.3, 35.0, and 23.7-point decrease in 5-year HOS-ADL, HOS-SS, and mHHS, respectively (all P < .05). Regarding surgical benefit in comparison with normal weight patients, patients in the overweight and obese groups were as likely to achieve MCID (reciprocal odds ratio [ROR]: 1.5 and 1.2, respectively, both P > .05), but patients in the morbidly obese group were not. All groups were significantly less likely than the normal weight group to achieve PASS (ROR: overweight 5.2, obese 14.1, morbidly obese 13.0; all P < .05) and SCB (ROR: overweight 3.9, obese 7.8, morbidly obese 20.3; all P < .05).

CONCLUSION

There were significant improvements in at least 1 outcome score across all BMI groups with arthroscopic treatment of FAIS. While the normal weight patients demonstrated universal improvement in all patient-reported outcomes and significantly greater likelihood of achieving PASS and SCB, the higher BMI groups still demonstrated significant improvement in function and pain, except for the morbidly obese group. Patients with morbid obesity demonstrated long-term pain improvement, although they did not experience functional improvement.

Femoroacetabular Impingement Syndrome

Femoroacetabular impingement (FAI) syndrome is one of the most rapidly evolving etiologies of hip pain. The 2016 Warwick Agreement consensus statement defined FAI syndrome as a triad of symptoms, signs, and radiographic findings. Cam morphology is more likely in athletes and is associated with repetitive hip loading in maximal flexion during adolescence. Much less is known about the development of pincer morphology. Physical therapy improves pain and function, justifying a trial before pursuing surgery. Musculoskeletal injections are utilized for FAI syndrome, but the evidence is limited. Arthroscopic surgery for FAI syndrome can correct the morphological changes and address the underlying soft tissue injuries. Recent studies evaluated reliable indicators of surgical outcomes, the most reliable of which is the presurgical presence of osteoarthritis. Recent studies demonstrate the efficacy of surgery, but with the risk of complication and no guarantee of a return to the same level of sport.

MRI-based 3D models of the hip joint enables radiation-free computer-assisted planning of periacetabular osteotomy for treatment of hip dysplasia using deep learning for automatic segmentation

Introduction

Both Hip Dysplasia(DDH) and Femoro-acetabular-Impingement(FAI) are complex three-dimensional hip pathologies causing hip pain and osteoarthritis in young patients. 3D-MRI-based models were used for radiation-free computer-assisted surgical planning. Automatic segmentation of MRI-based 3D-models are preferred because manual segmentation is time-consuming.To investigate(1) the difference and(2) the correlation for femoral head coverage(FHC) between automatic MR-based and manual CT-based 3D-models and (3) feasibility of preoperative planning in symptomatic patients with hip diseases.

Methods

We performed an IRB-approved comparative, retrospective study of 31 hips(26 symptomatic patients with hip dysplasia or FAI). 3D MRI sequences and CT scans of the hip were acquired. Preoperative MRI included axial-oblique T1 VIBE sequence(0.8 mm³ isovoxel) of the hip joint. Manual segmentation of MRI and CT scans were performed. Automatic segmentation of MRI-based 3D-models was performed using deep learning.

Results

(1)The difference between automatic and manual segmentation of MRI-based 3D hip joint models was below 1 mm(proximal femur 0.2 ± 0.1 mm and acetabulum 0.3 ± 0.5 mm). Dice coefficients of the proximal femur and the acetabulum were 98 % and 97 %, respectively. (2)The correlation for total FHC was excellent and significant(r = 0.975, p < 0.001) between automatic MRI-based and manual CT-based 3D-models. Correlation for total FHC (r = 0.979, p < 0.001) between automatic and manual MR-based 3D models was excellent.(3)Preoperative planning and simulation of periacetabular osteotomy was feasible in all patients(100 %) with hip dysplasia or acetabular retroversion.

Conclusions

Automatic segmentation of MRI-based 3D-models using deep learning is as accurate as CT-based 3D-models for patients with hip diseases of childbearing age. This allows radiation-free and patient-specific preoperative simulation and surgical planning of periacetabular osteotomy for patients with DDH.

Immediate Versus Delayed Hip Arthroscopy for Femoroacetabular Impingement: An Expected Value Decision Analysis

INTRODUCTION

Hip arthroscopy is an increasingly used surgical procedure for both intra- and extra-articular hip pathologies, including femoroacetabular impingement (FAI). Although the arthroscopic approach is known to be preferable to open, the optimal timing of such intervention is unclear. The purpose of this study was to carry out an expected value decision analysis of immediate versus delayed hip arthroscopy for FAI. Its hypothesis is immediate hip arthroscopy is the preferable treatment option.

METHODS

An expected value decision analysis was implemented to systematize the decision-making process between immediate and delayed hip arthroscopies. A decision tree was created with options for immediate and delayed surgeries with utilities characterizing each state obtained from surveying 70 patients. Fold-back analysis was then carried out, calculating expected values by multiplying the utility of each health outcome by the probability of that outcome. Corresponding expected values were then summed to "fold back" the decision tree one layer at a time. This was repeated until overall expected values (0 to 100) for immediate and delayed hip arthroscopies resulted with the higher value indicating the preferable option.

RESULTS

Fold-back analysis demonstrated that immediate hip arthroscopy is the preferred treatment for FAI over delayed with expected values of 78.27 and 72.63, respectively. Restoration of good function after hip arthroscopy was the most notable contributor to this difference. Immediate hip arthroscopy remained superior even as vast adjustments to preoperative physical function were made in one-way sensitivity analysis. Complications of hip arthroscopy leading to total hip arthroplasty were the least notable contributors to overall expected values.

DISCUSSION

This study confirms that immediate surgery is the preferred option when using decision-making analysis combining patient-reported utilities of health outcomes and the probabilities of those outcomes from the literature. This is consistent across a range of estimates of poor function in both the delayed and immediate surgery arms.

Arthroscopy versus nonoperative treatment of symptomatic femoroacetabular impingement syndrome: A systematic review and meta-analysis

BACKGROUND

Presently, hip arthroscopy is a widely adopted surgical intervention for the treatment of femoroacetabular impingement (FAI). However, there is insufficient evidence regarding which between arthroscopy and nonoperative treatment is more optimal for symptomatic FAI.

METHODS

MEDLINE, Embase, Web of Science, and the Cochrane Library were systematically searched for studies that compared arthroscopy and nonoperative interventions for FAI treatment from inception to August 4, 2020. We included studies that directly compared surgical and nonsurgical treatment for symptomatic FAI and excluded those that did not use arthroscopic treatment as a surgical technique and studies performed on patients with concomitant diagnoses instead of pure FAI. We compared the following clinical outcome scores at 6 and 12 months of follow-up: International Hip Outcome Tool 33 (iHOT-33), hip outcome score (HOS), EuroQol-visual analog scale (EQ-VAS), modified Harris hip score (mHHS), and nonarthritic hip score (NAHS).

RESULTS

Five studies totaling 838 patients were included in the qualitative and quantitative synthesis; 382 patients underwent hip arthroscopy, and 456 patients were treated by nonoperative interventions. At 6 months of follow-up, there were no statistically significant differences in iHOT-33 ratings (mean difference [MD] = 7.92, P = .15), HOS (MD of HOS-ADL = 5.15, P = .26 and MD of HOS-Sports = 2.65, P = .79, respectively), and EQ-VAS (MD = 1.22, P = .76) between the 2 treatment strategies. At 12 months of follow-up, the arthroscopy group had a greater mean improvement in iHOT-33 score than the conservative treatment group (MD = 8.42, P = .002), but there was no difference between the groups in terms of mHHS rating (MD = -0.24, P = .83) and NAHS (MD = -2.08, P = .09).

CONCLUSION

Despite arthroscopy being associated with significantly superior iHOT-33 scores after 12 months of follow-up, we were unable to discern the difference between the treatment strategies using other scoring methods, such as HOS, EQ-VAS, mHHS, and NAHS. Further studies will be needed to conclusively determine if 1 strategy is superior to the other for treating FAI.

Patient-Reported Outcomes Measurement Information System Physical Function Has a Lower Effect Size and is Less Responsive Than Legacy Hip Specific Patient Reported Outcome Measures Following Arthroscopic Hip Surgery

PURPOSE

To compare the use and responsiveness of Patient Reported Outcomes Measurement Information System (PROMIS) to legacy patient-reported outcome measures (PROMs) in patients undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAIS) at 6-month follow-up.

METHODS

Data from patients who underwent primary hip arthroscopy with routine capsular closure between August 2018 and January 2019 for the treatment of FAIS were analyzed. Preoperative outcomes, 6-month postoperative outcomes, and demographics were recorded. Primary outcome measures included PROMIS Physical Function (PROMIS-PF), PROMIS Pain Interference (PROMIS-PI), and PROMIS Depression. The legacy PROMs included Hip Outcome Score Activities of Daily Living (HOS-ADL), Hip Outcome Score Sport Subscale (HOS-SS), and the international hip outcome tool 12 questions (iHOT-12). Floor and ceiling effects along with the responsiveness and Cohen's d effect size of each PROM tool were calculated.

RESULTS

Ninety-six patients with an average age and body mass index of 32.4 ± 11.9 years and 25.9 ± 6.1 kg/m², respectively, were included in the final analysis. All outcomes were significantly higher at 6 months compared with the preoperative level (P < .001) except for PROMIS Depression (P = .873). PROMIS-PF demonstrated excellent correlation with HOS-SS (r = 0.81; P < .001), very good correlation with HOS-ADL (r = 0.73; P < .001), and good correlation with iHOT-12 (r = 0.68; P < .001). No floor was observed for any measure. The effect size was large for all outcomes, except PROMIS Depression (d = 0.04), but largest for iHOT12 (d = 1.87) followed by HOS-ADL (d = 1.29). The iHOT-12 was more responsive than PROMIS-PI (relative efficiency [RE] = 3.95), PROMIS-PF (RE = 4.13), HOS-ADL (RE = 2.26), and HOS-SS (RE = 3.84). HOS-SS was similarly responsive to PROMIS-PI (RE=1.03) and PROMIS-PF (RE=1.08). However, PROMIS-PF was overall the least responsive.

CONCLUSIONS

In patients at 6 months postoperatively from hip arthroscopy for FAIS, iHOT-12 was the most responsive and had the largest effect size. In contrast, PROMIS-PF had a lower effect size compared with legacy hip-specific PROMs. Additionally, PROMIS-PF did not correlate as well with iHOT-12 compared with HOS-SS.

LEVEL OF EVIDENCE

Level IV, case series.

Treatment of femoroacetabular impingement by arthroscopy versus anterior mini-open approach: Case-control study of a continuous series of 91 cases at a mean 4.6 years' follow-up

INTRODUCTION

Femoroacetabular impingement is a frequent cause of hip pain, and can be managed by conservative surgery. Many studies assessed postoperative course, but none compared operative techniques within a given population. We therefore conducted a retrospective case-control study comparing the minimally invasive anterior Hueter approach versus arthroscopy, assessing difference in 1) functional gain and 2) complications and 3) analyzing the impact of labral or cartilage lesions on functional scores.

HYPOTHESIS

Clinical results do not differ between the mini-open and arthroscopic approach.

MATERIAL AND METHOD

Between 2007 and 2018, 91 hips in 84 patients were treated for femoroacetabular impingement: 69/91 (75.8%) cam effect, 6/91 pincer effect (6.6%) and 16/91 mixed (17.6%). Fifty-five were treated by arthroscopy and 36 by the Hueter mini-open approach. There were 20 female and 71 male hips. Mean age at surgery was 32 years (range, 17-55 years). Potential predictive factors comprised Nötzli alpha angle, labral/cartilage lesion and type of surgery.

RESULTS

Mean follow-up was 4.6 years (range, 1-16 years), with no loss to follow-up. The arthroscopy and Hueter groups showed no differences in functional improvement on Oxford-12 score (gain, -6.7±5.9 versus -6.2±8.1 (p=0.73), Postel Merle d'Aubigné (PMA) score (gain, 1.3±1 versus 1.1±0.9; p=0.41), operative time (75 versus 67min; p=0.16), or alpha angle correction (-10.9±12.9 versus -9.8±7.1; p=0.22). Complications did not differ: 1/55 severe complications after arthroscopy (1 definitive femoral nerve palsy) versus 4/36 non-severe complications after Hueter (3 cases of dysesthesia in the lateral cutaneous nerve of the thigh, 1 rectus femoris enthesopathy) (p=0.15). Labral lesions (37/91) did not affect clinical outcome: gain, 1.2±1 versus 1.3±0.9 on PMA (p=0.514) and -7.3±6 versus -6±7.3 on Oxford-12 (p=0.366). Cartilage lesions (27/91) were associated with poorer outcome on PMA (gain, 1±1.1 versus 1.3±0.9; p=002) but not on Oxford-12 (gain, -6.1±7.3 versus -6.7±6.6; p=0.288).

CONCLUSION

Impingement correction by the minimally invasive anterior Hueter approach gave clinical results comparable to those of hip arthroscopy in terms of Oxford and PMA scores, alpha angle correction, operative time and complications. Cartilage lesions were associated with poorer clinical results.

LEVEL OF EVIDENCE

III; retrospective case-control study.

Improving function in people with hip-related pain: a systematic review and meta-analysis of physiotherapist-led interventions for hip-related pain

OBJECTIVE

To report the effectiveness of physiotherapist-led interventions in improving pain and function in young and middle-aged adults with hip-related pain.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

A comprehensive, reproducible search strategy was performed on five databases in May 2019. Reference lists and grey literature were also searched.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Population: people aged ≥18 years with hip-related pain (with or without a diagnosis of femoroacetabular impingement syndrome).

INTERVENTION(S)

physiotherapist-led interventions for hip pain. Comparators: sham treatment, no treatment or other treatment (eg, hip arthroscopic surgery).

OUTCOMES

primary outcomes included patient-reported hip pain and function. Secondary outcomes included physical function measures.

RESULTS

1722 papers were identified. After exclusion criteria were applied, 14 studies were included for analysis. They had varied risk of bias. There were no full-scale placebo-controlled randomised controlled trials (RCTs) of physiotherapist-led treatment. Pooled effects ranged from moderate effects (0.67 (95% CI 0.07 to 1.26)) favouring physiotherapist-led intervention over no treatment post-arthroscopy, to weak effects (-0.32 (95% CI 0.57 to 0.07)) favouring hip arthroscopy over physiotherapist-led treatment.

CONCLUSION

Physiotherapist-led interventions might improve pain and function in young and middle-aged adults with hip-related pain, however full-scale high-quality RCT studies are required.

PROSPERO REGISTRATION NUMBER

CRD42018089088.

Rate of Surgery and Baseline Characteristics Associated With Surgery Progression in Young Athletes With Prearthritic Hip Disorders

Background:

Prearthritic hip disorders (PAHD), such as femoroacetabular impingement (FAI), acetabular dysplasia, and acetabular labral tears, are a common cause of pain and dysfunction in adolescent and young adult athletes, and optimal patient-specific treatment has not been defined. Operative management is often recommended, but conservative management may be a reasonable approach for some athletes.

Purpose:

To identify (1) the relative rate of progression to surgery in self-reported competitive athletes versus nonathletes with PAHD and (2) baseline demographic, pain, and functional differences between athletes who proceeded versus those who did not proceed to surgery within 1 year of evaluation.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

An electronic medical record review was performed of middle school, high school, and college patients who were evaluated for PAHD at a single tertiary-care academic medical center between June 22, 2015, and May 1, 2018. Extracted variables included patients’ self-reported athlete status, decision to choose surgery within 1 year of evaluation, and baseline self-reported pain and functional scores on Patient-Reported Outcomes Measurement Information System (PROMIS) domains, the Hip disability and Osteoarthritis Outcome Score (HOOS), and the modified Harris Hip Score.

Results:

Of 260 eligible patients (289 hips), 203 patients (78%; 227 hips) were athletes. Athletes were no more likely to choose surgery than nonathletes (130/227 hips [57%] vs 36/62 hips [58%]; relative risk [RR], 0.99 [95% CI, 0.78-1.25]). Among athletes, those who proceeded to surgery over conservative care were more likely to be female (81% vs 69%; RR, 1.34 [95% CI, 0.98-1.83]) and had more known imaging abnormalities (FAI: 82% vs 69%, RR, 1.47 [95% CI, 1.09-1.99]; dysplasia: 48% vs 27%, RR, 1.44 [95% CI, 1.16-1.79]; mixed deformity: 30% vs 10%, RR, 2.91 [95% CI, 1.53-5.54]; known labral tear: 84% vs 40%, RR, 2.79 [95% CI, 2.06-3.76]). Athletes who chose surgery also reported worse baseline hip-specific symptoms on all HOOS subscales (mean difference, 10.8-17.7; P < .01 for all).

Conclusion:

Similar to nonathletes, just over half of athletes with PAHD chose surgical management within 1 year of evaluation. Many competitive athletes with PAHD continued with conservative management and deferred surgery, but more structural hip pathology and worse hip-related baseline physical impairment were associated with the choice to pursue surgery.

Epidemiology of Traumatic and Overuse Injuries in Swiss Professional Male Ice Hockey Players

Background:

Ice hockey injury patterns in Europe were last evaluated in the 1990s.

Purpose:

The aim of this study was to assess the frequency, type, location, and incidence of traumatic injuries, as well as the prevalence and relative effect of overuse injuries in professional male ice hockey players.

Study Design:

Descriptive epidemiology study.

Methods:

Traumatic injuries were assessed using a standardized injury report form over a 1-year period (including the preparatory phase and season). The Oslo Sports Trauma Research Centre Overuse Injury Questionnaire was used to determine overall and substantial overuse injuries and their relative effect on ice hockey players.

Results:

Five Swiss National League teams participated in the study. From a total of 321 recorded injuries, 179 led to time loss from sport. The game-related time-loss injury incidence during the season was 88.6/1000 player-game hours.Time-loss injuries affected mainly the hip/groin/thigh region (23%), followed by the head (17%). Most time-loss injuries were classified as muscle strains (24%), followed by concussions (18%). The most common injury mechanism involved collision with an opponent’s body (31%), and right forward players (23%) were most likely to report a game-related injury. Most injuries (27%) occurred within the defending zone along the boards. The average prevalence rates of all overuse and substantial overuse injuries were 49% and 13%, respectively. The hip/groin displayed the highest average prevalence for all overuse problems (16%), translating to the highest relative effect.

Conclusion:

Muscle strains and concussions were the most frequent time-loss injuries in Swiss professional ice hockey players. The hip/groin was the most affected region for both traumatic and overuse injuries.