Historical review of arthroscopic surgery of the hip

SSR white paper: guidelines for utilization and performance of direct MR arthrography

OBJECTIVE

Direct magnetic resonance arthrography (dMRA) is often considered the most accurate imaging modality for the evaluation of intra-articular structures, but utilization and performance vary widely without consensus. The purpose of this white paper is to develop consensus recommendations on behalf of the Society of Skeletal Radiology (SSR) based on published literature and expert opinion.

MATERIALS AND METHODS

The Standards and Guidelines Committee of the SSR identified guidelines for utilization and performance of dMRA as an important topic for study and invited all SSR members with expertise and interest to volunteer for the white paper panel. This panel was tasked with determining an outline, reviewing the relevant literature, preparing a written document summarizing the issues and controversies, and providing recommendations.

RESULTS

Twelve SSR members with expertise in dMRA formed the ad hoc white paper authorship committee. The published literature on dMRA was reviewed and summarized, focusing on clinical indications, technical considerations, safety, imaging protocols, complications, controversies, and gaps in knowledge. Recommendations for the utilization and performance of dMRA in the shoulder, elbow, wrist, hip, knee, and ankle/foot regions were developed in group consensus.

CONCLUSION

Although direct MR arthrography has been previously used for a wide variety of clinical indications, the authorship panel recommends more selective application of this minimally invasive procedure. At present, direct MR arthrography remains an important procedure in the armamentarium of the musculoskeletal radiologist and is especially valuable when conventional MRI is indeterminant or results are discrepant with clinical evaluation.

A comprehensive review of hip arthroscopy techniques and outcomes

Transforming the orthopedic landscape, hip arthroscopy pioneers a minimally invasive surgical approach for diagnosing and addressing hip pathologies. With its origins dating back to Burman's 1931 cadaveric study, this groundbreaking technique gained clinical relevance in 1939 through Takagi's report. However, the 1980s marked the actual emergence of hip arthroscopy for treating a wide range of hip disorders. Now, a staple in modern orthopedics, hip arthroscopy empowers patients with previously undiagnosed and untreated hip conditions, enabling them to obtain relief and reclaim their lives. By employing a compact camera and specialized tools, surgeons expertly navigate the hip joint, performing procedures from excising loose bodies and mending labral tears to addressing femoroacetabular impingement and tackling other intricate issues. This innovative approach has dramatically elevated patients' quality of life, allowing them to embrace targeted treatments and resume daily activities without resorting to lifestyle alterations.

THE STATE OF HIP ARTHROSCOPY IN RUSSIA: ASSESSMENT BASED ON A SOCIOLOGICAL SURVEY OF DOCTORS

Background.Hip arthroscopy is a minimally invasive surgical technique most commonly performed to correct femoroacetabular impingement (FAI). The number of hip arthroscopy performed in Russia is unknown. Information about this surgical technique is also very limited in our country.The aim of the study was to assess the level of hip arthroscopy in Russia.Methods.A sociological survey of orthopaedic surgeon with experience in performing hip arthroscopy was conducted. The questionnaire was posted on the Google Forms platform. The survey included 54 surgeons from Russian clinics, 45 people filled out the questionnaire.Results.The majority of specialists (73,30,06%) were trained in hip arthroscopy. More than half of the respondents (68,80,06%) are currently engaged in this surgical area, however, in 45,160,07% of them, the number of operations does not exceed 5 per year. For surgeons who have completed two or more training courses, the volume of operations performed is higher (p0,05). 51,110,07% of doctors perform arthroscopy using an alternative technique. There are 2,5 time more specialists doing just bone resection, than surgeons who apply any kind of reconstruction technique while treating FAI (p0,05). Fifteen respondents (48,390,08%) perform debridement as an attempt to delay arthroplasty. The most common difficulties faced by surgeon are problems with the diagnosis of FAI (400,02%), lack of the necessary tools (400,02%) and sufficient time to master the technique (33,30,07%). Only three (6,60,07%) respondents believed to achieve planned results, 93,30,03% of surgeons said that it is not always possible to achieve the desired outcomes.Conclusion. Hip arthroscopy in Russia is not very common, the volume of such interventions is insignificant. Doctors not skilled in arthroscopic hip surgery predominate. Factors impeding the development of this area in our country are related to teaching methods, FAI diagnostics, the lack of necessary instruments for performing operations, and the lack of time for specialists to master surgical techniques.

Peripheral Nerve Block for Hip Arthroscopy Does Not Have any Clinical Advantage Compared With Local Anesthetic Regarding Pain Management: A Meta-analysis of Randomized Controlled Trials

PURPOSE

To evaluate the efficacy of peripheral nerve block on reduction in opioid consumption and pain control after hip arthroscopy.

METHOD

To identify studies evaluating the effects of peripheral nerve block on pain control and reduction in opioid consumption in hip arthroscopy, we searched all records in the PubMed, Embase, and Cochrane Library databases until May 2021. Studies with the following characteristics were considered eligible: 1) patients who underwent a hip arthroscopy (population); 2) patients who received peripheral nerve block (intervention); 3) patients who did not receive peripheral nerve block (comparator); 4) record of total opioid consumption as a primary outcome and pain level at 1, 3 to 6, and 24 hours after surgery, patient satisfaction, and incidence of nausea and vomiting as secondary outcomes (outcomes); and 5) randomized controlled trial (study design). Data were independently extracted by two reviewers and synthesized using a random or fixed-effects model, according to the heterogeneity.

RESULTS

Eight RCTs were finally included in the meta-analysis. There were no significant differences in postoperative opioid consumption at 24 hours (standardized mean difference [SMD] = -0.091, 95% confidence interval [CI] [-0.270, 0.089]) or in visual analog scale (VAS) score at 1 (SMD = 0.299, 95% CI [-0.758, 0.160]), 3 to 6 (SMD = -0.304, 95% CI [-0.655, 0.047]), and 24 (SMD = -0.230, 95% CI [-0.520, 0.060]) hours postoperatively between the peripheral nerve block and control groups. Moreover, no significant differences were observed in patient satisfaction (SMD < 0.001, 95% CI [-0.284, 0.284]) or the incidence of nausea and vomiting (SMD = 0.808, 95% CI [0.311, 2.104]) between the two groups.

CONCLUSION

Peripheral nerve block for hip arthroscopy has no clinical advantage regarding pain management after surgery when compared with the group that received the local infiltration of analgesics without peripheral nerve block.

LEVEL OF EVIDENCE

Level II, meta-analysis of level I and II randomized controlled trials (RCTs).

Incidence of heterotopic ossification following hip arthroscopy is low: considerations for routine prophylaxis

PURPOSE

This scoping review aims to map and summarise the available literature on heterotopic ossification (HO) following hip arthroscopy, with particular focus on incidence, distribution as per Brooker classification, efficacy of prophylactic measures and factors that may influence the likelihood of production of HO.

METHODS

A computer-based search was performed on PubMed, Embase, Emcare, Cinahl, ISI web of science and Scopus using the terms 'heterotopic ossification' and 'hip arthroscopy'. Articles reporting heterotopic ossification following hip arthroscopy for any condition were included after two-stage title/abstract and full-text screening.

RESULTS

Of the 663 articles retrieved, 45 studies were included. The proportion of patients with HO ranged from 0 to 44%. The majority of the cases were either Brooker grade I or II. Of the six studies investigating the effect of NSAID prophylaxis, five reported a significantly lower incidence of heterotopic ossification associated with its use. Weak evidence suggests that an outside-in arthroscopic approach, no capsular closure, male sex and mixed cam and pincer resection may be associated with an increased risk of HO.

CONCLUSION

Although there is a large variation in rates of HO following hip arthroscopy in the current literature, the majority of studies report a low incidence. Evidence exists advocating the administration of post-operative NSAIDs to reduce the incidence of HO following hip arthroscopy. This, combined with the low risk of complications, means there is a favourable risk-benefit ratio for prophylactic NSAID used in HA. Future research should work to identify patient clinical and demographic factors which may increase the risk of development of HO, allowing clinicians to risk stratify and select only specific patients who would benefit from receiving NSAID prophylaxis.

Low-Fidelity Arthroscopic Simulation Training in Trauma and Orthopaedic Surgery: A Systematic Review of Experimental Studies

PURPOSE

To identify and appraise evidence assessing the effectiveness of low-fidelity arthroscopic simulation in the acquisition of arthroscopic surgical skills in a novice population.

METHODS

Four databases were electronically searched in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) algorithm. Studies from any year that described the use of orthopaedic, low-fidelity arthroscopic training models in novice populations were included. Questionnaires, case studies, and review studies were excluded. Risk of bias assessment was conducted using the Cochrane Collaboration's Risk of Bias Tool or the Cochrane Risk of Bias in Non-Randomised Studies of Interventions (ROBINS-I) checklist.

RESULTS

Sixteen studies were identified. Using the PRISMA algorithm, 6 studies were included with a total of 131 novice participants. Individual studies ranged from 8 to 40 novices and were of Level I to II evidence. Outcome measurements varied between studies (total 16 different outcomes used). Various outcome measures used for assessing arthroscopic surgical skills within all 6 studies demonstrated significant improvement. A cross-study subjective outcome synthesis revealed low-fidelity arthroscopic simulators reduced time to completion outcomes (2 studies, P < .05), increased Arthroscopic Surgical Skill Evaluation Tool scores (2 studies, P < .01), and confirmed face validity (2 studies) and transfer of skills to cadavers (2 studies) or live patients (1 study). Cost data were under-reported in all studies apart from one.

CONCLUSIONS

Arthroscopic training using low-fidelity simulators likely improves the performance of novice participants in completing basic arthroscopic procedures. These simulators may also be more cost effective and thus more implementable than their high-fidelity counterparts.

LEVEL OF EVIDENCE

Level II, systematic review of Level I-II studies.

Portal Setup: the Key Point in the Learning Curve for Hip Arthroscopy Technique

OBJECTIVE

To analyze the learning curve experience of hip arthroscopy based on patient demographics, surgical time, portal setup time, and postoperative complications and to find the key point in the learning curve.

METHODS

From May 2016 to February 2019, a prospective study on the learning curve experience of hip arthroscopy was performed in our hospital. We evaluated the first 50 consecutive hip arthroscopy procedures performed by a single surgeon. There were nine females and 41 males with a mean age of 30.8 years. We divide the patients into early group and late group according to the date of their operation, with each group including 25 patients. Data on patient demographics, types of procedure, surgical time, portal setup time, and postoperative complications were collected. Functional scores were assessed with the modified Harris Hip Score (mHHS).

RESULTS

Patients were followed up for 16.4 months on average (range, 13-27 months). The early group of patients had a mean age of 35.2 years and the late group a mean age of 26.5 years. The most common procedures performed for the early group were debridement (17 patients, 68%), and in the late group, most patients underwent labral repair (18 patients, 72%). Mean total surgical time was 168 min for the early group and 143 min for the late group, and there was no statistically significant difference between two groups. The portal setup time in the early group and late group was 40.2 ± 12.4 min and 18.5 ± 6.2 min, respectively (P < 0.001), and the portal setup time was significantly longer in the early group. Further analysis of the learning curve of portal setup showed that the average portal setup time was not statistically significant changed after 30 cases. There were six complications including iatrogenic cartilage injury and iatrogenic labrum injury in the early group and five complications including perineal crush injury and nerve stretch injury in the late group. The functional score of patients in the late group was significantly higher than that in the early group during follow-up.

CONCLUSION

The steep learning curve of hip arthroscopy is mainly caused by the challenge of portal setup and portalrelated complications were more common in the early group than in the late group. Surgical time is not an effective indicator for evaluating progress on the learning curve of hip arthroscopy.

The Top 100 Most-Cited Articles on Ankle Arthroscopy: Bibliometric Analysis

The aim of this study was to analyze the 100 most-cited articles on ankle arthroscopy. Using the keyword ankle arthroscopy, the 100 most-cited articles in the Web of Science database were analyzed. Original articles, reviews, clinical trials, and case reports were included in the study. The search period included studies conducted between the years 1990 and 2020. The number of citations of the 100 most-cited articles ranged from 56 to 225 (mean, 95.52). The total number of citations was 9552. Among the articles examined, most were produced in the United States of America. The American Journal of Sports Medicine was the journal in which the most-cited articles were more frequently published. The article topic that drew attention most was osteochondral defects. Ankle arthroscopy is a technique that is still open to development and is a current topic that should be studied. Analyzing the 100 most-cited articles, it can be seen that most studies are on osteochondral defects. More articles will increase scientific data and provide more realistic solutions to ankle problems.

Outcomes of Hip Arthroscopy in Patients with Femoroacetabular Impingement and Concomitant Tönnis Grade II Osteoarthritis or Greater: Protocol for a Systematic Review

Introduction

Outcomes of hip arthroscopy for femoroacetabular impingement and concomitant moderate- to advanced hip osteoarthritis (Tönnis Grade II or greater) is still a matter of debate as findings in the literature are controversial. This study aims to investigate whether hip arthroscopy is effective in treating patients with femoroacetabular impingement and Tönnis hip osteoarthritis Grade II or greater.

Methods and Analysis

The protocol follows the PRISMA-P guidelines. The systematic review is registered in the International Prospective Register for Systematic Reviews and Meta-analysis (PROSPERO) under the registration number: CRD42020210936. The search will include multiple databases: MEDLINE, EMBASE, Web of Science Core Collection and Cochrane library. The screening and selection process will be performed by two independent researchers based on predefined criteria. All studies published in English or German from inception to 1^st of December 2020 that investigated outcomes of hip arthroscopy in patients with Tönnis grade II or greater of hip osteoarthritis will be considered eligible. The risk of bias and quality of articles will be assessed using the MINORS tool. Methodological inconsistency and heterogeneity will be explored using the I² test. This assessment will be used to provide recommendations using the GRADE system.

Ethics and Dissemination

Separate ethical approval is not required. This study will be a comprehensive and rigorous systematic review on all published articles reporting on outcomes of hip arthroscopy for femoroacetabular impingement and concomitant hip osteoarthritis Tönnis Grade II or greater. It will explore patient reported outcomes as well as radiological outcomes, complications, rates of revision surgery and rates of conversion to total hip replacement (THR). Results of the current review will be published in a peer-reviewed scientific journal and disseminated on research platforms according to copyright rules and rights.

Highlights

Hip arthroscopy is used to treat femoroacetabular impingement and is effective in patients that have concomitant hip osteoarthritis Tönnis Grade 0 or 1.Outcomes of hip arthroscopy in patients with femoroacetabular impingement and in moderate to advanced osteoarthritis - Tönnis Grade 2 or greater, is a matter of debate.The purpose of the current systematic review is to elucidate, stratify and critical appraise the current evidence on outcomes in this patient subpopulation.

Neuraxial Anesthesia Is Associated With Decreased Pain Scores and Post-Anesthesia Care Unit Opioid Requirement Compared With General Anesthesia in Hip Arthroscopy

PURPOSE

We sought to identify the immediate postoperative differences in opioid use, pain scores, and post-anesthesia care unit (PACU) length of stay (LOS) after hip arthroscopy related to the type of anesthesia used for the surgical procedure.

METHODS

Patients undergoing hip arthroscopy for femoroacetabular impingement syndrome with labral tears by a single surgeon at an academic center between October 2017 and July 2019 were reviewed retrospectively. The primary outcome was PACU opioid administration, measured by morphine equivalents. Secondary parameters included total LOS, postincision LOS, PACU LOS, and PACU arrival/discharge pain scores. Analyses conducted were t tests, Wilcoxon rank sum tests, or χ² tests.

RESULTS

A total of 129 patients met inclusion criteria for this study; 54 male and 75 female, with an average age of 28 (±10.1) years. In total, 52 (40.3%) had general anesthesia and 77 (59.7%) had neuraxial anesthesia, including spinal, epidural, and combined spinal-epidural anesthesia, which were intermixed throughout the study period. Intraoperative and PACU opioid administration demonstrated a significant difference in medians. Neuraxial methods required a lower morphine equivalents in both the operating room (30.0 vs 53.9, P = .001) and PACU (18.2 vs 31.2, P = 0.002). Neuraxial anesthesia had lower median PACU arrival and discharge pain scores (0.0 vs. 5.0, P = .001, 3.0 vs. 4.0, P = .013). There was no statistically significant difference in postincision LOS or traction time. General anesthesia was associated with a longer PACU phase 1 time (1.0 vs 1.3 hours, P = .005). No major adverse events such as death, disability, or prolonged hospitalization occurred in either group.

CONCLUSIONS

Neuraxial anesthesia use in routine hip arthroscopy was associated with lower immediate postoperative pain scores, lower intraoperative and immediate postoperative opioid requirements, and may be associated with shorter anesthesia recovery time without any major adverse events when compared with general anesthesia.

LEVEL OF EVIDENCE

III, Retrospective Comparative Study.

Computer assistance in hip preservation surgery-current status and introduction of our system

INTRODUCTION

Preservation surgery of the hip with open or arthroscopic approach has always been challenging as complex 3-D anatomy and limited surgical access make intraoperative evaluation difficult. Recent advances in computer technology offer a wide range of innovative solutions with a goal to improve accuracy and safety of corrective procedures on human joints.

METHOD

The author critically reviews currently available literature in the field of computer assistance in hip preservation surgery. Basic features of unique planning software and navigation surgical system used in treatment of femoroacetabular impingement and hip dysplasia are introduced.

RESULTS

Currently available software provides preoperative identification of hip deformity on CT-based 3-D model and planning of the surgical correction using kinematic protocols. Real-time intraoperative 3-D orientation is possible, and execution of surgical correction can be performed either with navigation of surgical tools or with printed templates. Computer assistance in hip preservation surgery is in the developing phase. First clinical experiences of its use in treatment of femoroacetabular impingement, hip dysplasia, hip tumors, and avascular necrosis of the femoral head are promising.

CONCLUSION

Computer assistance has been applied for treatment of several hip disorders. Technical advances are suggested and quality basic studies and clinical trials are encouraged for the novel technology to become more user friendly and widely accepted.

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSION

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

The Top 50 Most Influential Articles in Hip Arthroscopy

PURPOSE

To identify the 50 most frequently cited publications related to hip arthroscopy.

METHODS

The Clarivate Analytics Web of Knowledge database was used to search for publications relating to hip arthroscopy. The top 50 most cited articles that met the inclusion criteria were recorded and reviewed for various metrics.

RESULTS

The top 50 publications were cited a total of 8,306 times, with an average of 437.2 total citations per year. Of the 50 articles identified, 44 had been published since 2000. Case series, expert opinion articles, and review articles were the most common study types.

CONCLUSIONS

The majority of the most influential articles on hip arthroscopy are case series and expert opinions; however, as hip arthroscopy continues to become more widely performed, higher-level articles should supplant some of the articles included in this analysis. As indications for hip arthroscopy have expanded, so has its body of literature, with the vast majority of articles identified in our study having been published since 2000. Elucidating the 50 most cited articles in hip arthroscopy will allow practicing physicians a quick reference to the highest-yield articles and will allow residency programs to guide their education on the topic.

CLINICAL RELEVANCE

The top 50 list provides residents, fellows, and researchers with a comprehensive list of the major academic contributions to hip arthroscopy.

Prior arthroscopic treatment for femoro-acetabular impingement does not compromise hip arthroplasty outcomes: a matched-controlled study with minimum two-year follow-up

BACKGROUND

Femoro-acetabular impingement (FAI) is known as a predisposing factor in the development of osteoarthritis of the hip. In order to treat this condition, hip arthroscopy is considered as the gold standard in recent years. The number of performed hip arthroscopies has risen immensely. However, a number of patients with poor outcome after hip arthroscopy will require further surgical intervention, sometimes even conversion into THR (total hip replacement). The purpose of this study was to analyze whether outcomes of THR are affected by prior hip arthroscopy in these patients.

METHODS

Patients who underwent a THR following an ipsilateral hip arthroscopy were matched to a control group of THR patients with no history of prior ipsilateral hip surgery. Matching criteria were age, sex, body mass index, implants used, and surgical approach. Modified Harris Hip Score, surgical time, presence of heterotopic ossification, and post-operative complication were prospectively compared at a minimum two year follow-up.

RESULTS

Thirty-three THR after hip arthroscopy patients were successfully matched to control patients. There was no significant difference in mHHS between both groups (FAI treatment group 92.8 vs. control group 93.8, p = 0.07). However, FAI treatment group showed a lower mHHS score pre-operatively (48 vs. 60, p = 0.002). There was no significant difference in surgical time and post-operative complication rate. No heterotopic ossification could be found.

CONCLUSION

A prior hip arthroscopy has no affect to clinical outcomes of subsequent THR.

Increased Prevalence of Concomitant Psychiatric Diagnoses Among Patients Undergoing Hip Arthroscopic Surgery

Background

Active patients with musculoskeletal pain are not immune to psychological or psychiatric disease. Observations suggest that patients undergoing hip arthroscopic surgery may have an increased prevalence of comorbid psychiatric conditions.

Hypothesis

Patients undergoing hip arthroscopic surgery have an increased prevalence of concomitant psychiatric diagnoses compared with the general population as well as those undergoing anterior cruciate ligament (ACL) reconstruction.

Study Design

Case-control study; Level of evidence, 3.

Methods

A retrospective review of a medical claims database spanning from 2007 to 2016 was utilized to identify patients with a Current Procedural Terminology (CPT) code indicating that they had undergone hip arthroscopic surgery. This group was then dichotomized to those with or without an International Classification of Diseases, 9th Revision (ICD-9) and 10th Revision (ICD-10) diagnosis code indicating a psychological or psychiatric condition at any time before hip arthroscopic surgery or up to 2 years after hip arthrscopic surgery. As a control, ICD-9 and ICD-10 diagnosis codes for psychological or psychiatric conditions were determined in patients without a CPT code for hip arthroscopic surgery (general population) as well as for 2 surgical groups: those undergoing ACL reconstruction and those undergoing shoulder stabilization surgery. Prevalence was determined in all groups and compared using chi-square analysis.

Results

There were 22,676,069 patients in the database, with 2428 undergoing hip arthroscopic surgery. Those undergoing hip arthroscopic surgery had a 3-fold increased prevalence of concomitant psychiatric diagnoses compared with the general population (52% vs 17%, respectively; P < .0001). There was a significant difference in the prevalence of psychiatric diagnoses in the hip arthroscopic surgery group between male and female patients (46% vs 56%, respectively; P = .0061), with depression and anxiety being the 2 most common comorbid conditions. Those undergoing hip arthroscopic surgery also had a significantly increased prevalence of concomitant psychiatric diagnoses versus those undergoing ACL reconstruction (52% vs 28%, respectively; P < .0001) as well as those undergoing shoulder stabilization surgery (52% vs 42%, respectively; P < .0001).

Conclusion

Patients undergoing hip arthroscopic surgery had an increased prevalence of comorbid psychiatric conditions compared with the general population as well as those undergoing ACL reconstruction or shoulder stabilization surgery. Depression and anxiety were the most prevalent concomitant psychiatric diagnoses.

Arthroscopic excision of heterotopic ossification in the rectus femoris muscle causing extra-articular anterior hip impingement

Subspine impingement is an extra-articular hip impingement syndrome that usually occurs when there is abnormal contact between an enlarged or malorientated anterior inferior iliac spine (AIIS) and the distal anterior femoral neck in straight flexion of the hip. We present the case of a 13-year-old boy with a history of left groin pain and loss of range of movement of the hip for over six months following an avulsion fracture of the AIIS during a game of rugby. He was diagnosed with subspine impingement secondary to a large lesion of heterotopic ossification in the rectus femoris; this was dissected and extracted from the muscle in toto arthroscopically. This case highlights the importance of heterotopic ossification after injury as an important cause for subspine impingement in the young adult hip. This is the first report and describes subspine impingement secondary to a large lesion of heterotopic ossification.