SummaryBackground: Abnormal morphology of the anterior inferior iliac spine (AIIS) and the subspine region of the acetabular rim are increasingly being recognised as a source of symptomatic extra-articular hip impingement. This review article aims to highlight important differences in the pathogenesis, clinical presentation and management of extra-articular hip impingement from both the AI-IS and subspine bony regions, and the outcome following surgical intervention. Methods: A literature review was undertaken to examine the supporting evidence for AIIS and subspine hip impingement. A narrative account of the Author's professional experience in this area, including operative technique for arthroscopic correction, is also presented. Results: Abnormal morphology of the AIIS and subspine region has been classified using cadaveric, radiological and arthroscopic means; the clinical presentation and operative treatment has been documented in several case series studies. Dual pathology is often present -recognition and treatment of both intra-and extra-articular components are necessary for good postoperative outcome. Conclusions: AIIS and sub-spine hip impingement should be considered as distinct pathological entities, which may also co-exist. Symptom relief can be expected following arthroscopic deformity correction with the treatment of concomitant intra-articular pathology. Failure to recognise and treat the extra-articular component may affect postoperative outcome. Level of evidence: V.

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Aim: To examine the pathogenesis and clinical presentation of sports-related femoroacetabular impingement (SRFAI) in a large consecutive series of symptomatic athletes. Methods: Between January 2009 and February 2017 prospectively collected data from competitive athletes within the Gaelic Athletic Association (GAA), and who subsequently underwent arthroscopic treatment for symptomatic FAI, were analysed. Data was collected using internationally validated health questionnaires (Harris Hip Score, UCLA, SF-36, WOMAC) and recognised clinical (ROM, symptom presentation, provocation tests) and radiological (AP pelvis, Dunn, False profile) indicators/measures of FAI. Results: A total of 1021 consecutive cases (mean 26.6 ± 6.2 years) were included. In every case, conservative treatment failed to resolve symptoms with athletes attending an average of 2.4 ± 1.1 health care professionals prior to referral. Symptoms developed gradually (78%) and consisted primarily of groin pain (76.1%) and hip stiffness (76.5%) following activity. An acetabular rim deformity (pincer) was present in all cases; a cam deformity in 72.1%. The prevalence and degree of cam deformity increased with progressing age groups ( p < 0.001); mean lateral centre-edge angle remained static ( p = 0.456). Increasing CEA, alpha angle and presence of rim fracture was associated with a reduction in all ranges of hip movement ( p < 0.001). Conclusion: Symptomatic SRFAI presented in this large series of GAA athletes failed to resolve with non-operative treatment. Increasing hip deformity resulted in poorer ROM. Abnormal acetabular morphology remains static with increasing athletic age while cam deformity is progressive and most likely a secondary pathology.

Background: Measures of clinically meaningful improvement in patient-reported outcomes within orthopaedics are becoming a minimum requirement to establish the success of an intervention. Purpose: To (1) define the minimal clinically important difference (MCID) at 2 years postoperatively in competitive athletes undergoing hip arthroscopic surgery for symptomatic, sports-related femoroacetabular impingement utilizing existing anchor- and distribution-based methods and (2) derive a measure of the MCID using the percentage of possible improvement (POPI) method and compare against existing techniques. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: There were 2 objective outcome measures—the modified Harris Hip Score (mHHS) and 36-Item Short Form Health Survey (SF-36)—administered at baseline and 2 years postoperatively. External anchor questions were used to determine the MCID through mean change, mean difference, and receiver operating characteristic (ROC) techniques. Distribution-based calculations consisted of 0.5 SD, effect size, and standard error of measurement techniques. The POPI was calculated alongside each technique as an achieved percentage change of maximum available improvement for each athlete relative to the individual baseline score. The impact of the preoperative baseline score on the MCID was assessed by assigning athletes to groups determined by baseline percentiles. Statistical analysis was performed, with P < .05 considered significant. Results: There were 576 athletes (96% male; mean age, 25.9 ± 5.7 years). The MCID score change (and POPI) for the mHHS and SF-36 ranged from 2.4 to 16.7 (21.6%-63.6%) and from 3.3 to 24.9 (22.1%-57.4%), respectively. The preoperative threshold value for achieving the ROC-determined MCID was 80.5 and 86.5 for the mHHS and 70.1 and 72.4 for the SF-36 for the patient-reported outcome measure (PROM) score– and POPI-calculated MCID, respectively. Through the commonly used mean change method, 40.0% (mHHS) and 42.4% (SF-36) of athletes were unable to achieve the MCID because of high baseline scores and PROM ceiling effects compared with 0% when the POPI technique was used. A highly significant difference for the overall MCID was observed between preoperative baseline percentile groups for the mHHS ( P = .014) and SF-36 ( P = .004) (improvement in points), while there was no significant difference between groups for either the mHHS ( P = .487) or SF-36 ( P = .417) using the POPI technique. Conclusion: The MCID defined by an absolute value of improvement was unable to account for postoperative progress in a large proportion of higher functioning athletes. The POPI technique negated associated ceiling effects, was unrestricted by the baseline score, and may be more appropriate in quantifying clinically important improvement.

Background: Femoroacetabular impingement (FAI) is a common mechanical hip condition, prevalent in both the athletic and the general population. Surgical intervention is an effective treatment option that improves both symptoms and function in short- to medium-term follow-up. Few studies within the literature have reported the longer-term success of arthroscopic surgery. Purpose: The aim of this study was to quantify the 10-year survivorship and clinical outcome for patients treated arthroscopically for symptomatic FAI. Study Design: Case series; Level of evidence, 4. Methods: Patients from our hip registry (n = 119) completed patient-reported outcome measures (PROMs) including the modified Harris Hip Score (mHHS), University of California Los Angeles (UCLA) activity scale, 36-Item Short Form Health Survey (SF-36), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at a minimum of 10 years after arthroscopy (range, 10-12 years). Results were compared with baseline scores using the Wilcoxon signed rank test. The associations among several prognostic factors, which included age, sex, Tönnis grade, and labral treatment, and subsequent conversion to total hip replacement (THR) or repeat hip arthroscopy (RHA) were analyzed using the chi-square analysis. Relationships between range of motion and radiological findings with clinical outcome were also examined using Pearson correlation analysis. Minimal clinically important difference (MCID) was calculated using a distribution method (0.5 standard deviation of the change score), and substantial clinical benefit (SCB) was determined using an anchor method. Finally, receiver operating characteristic curves with subsequent Youden index were used to determine cutoffs for PROMs, which equated to a Patient Acceptable Symptom State (PASS). Results: A total of 8.4% of cases required conversion to THR, and 5.9% required RHA. Statistically significant improvements in mHHS, SF-36, and WOMAC scores, with high satisfaction (90%), were observed 10 years after surgery. No significant change was seen in activity level (UCLA score) despite patients being 10 years older. A high percentage of patients achieved MCID for mHHS (88%), SF-36 (84%), and WOMAC (60%). The majority of patients also achieved PASS (62% for mHHS, 85% for UCLA, 78% for SF-36, and 84% for WOMAC) and SCB (74% for mHHS, 58% for UCLA, 52% for SF-36, and 56% for WOMAC). Conclusion: Arthroscopic intervention is a safe and viable treatment option for patients with symptomatic FAI, and patients can expect long-term improvements and high satisfaction. Results indicated a high satisfaction (90%) and survivorship rate (91.6%), with excellent clinical outcome, 10 years after the initial procedure.