Labral Degeneration Predicts Inferior Mid-Term Outcomes in Hip Labral Repair: A Multicenter Comparative Analysis.

PURPOSE: To analyze and compare the mid-term outcomes of hip arthroscopy for patients with and without labral degeneration from multiple orthopaedic centers. The purpose of this research is to develop an understanding of the impacts of labral degeneration on patient outcomes following arthroscopic treatment of labral tears. METHODS: A prospective multicenter hip arthroscopy registry was queried for primary surgeries from January 2014 to October 2017 with completed 2-year International Hip Outcome Tool-12 (iHOT-12) reports. Patients were placed into cohorts based on the presence or absence of labral degeneration noted intraoperatively during hip arthroscopy. Degeneration was defined as yellowing, ossification, or calcification present in at least 50% of the labrum. Differences in baseline variation between groups were assessed with a Wilcoxon rank-sum test or χ2 test. Two-year outcomes were assessed with iHOT-12. Multivariate logistic regression models were fitted while controlling for age, body mass index, sex, and preoperative iHOT-12 scores to identify significant predictors of achieving the clinically significant thresholds of minimal clinically important difference, substantial clinical benefit, and patient-acceptable symptom scale. RESULTS: In total, 735 patients met inclusion criteria, of whom 613 had complete outcomes information. Relative to the control group, the labral degeneration group was significantly older (mean age 44 ± 11 years vs 33 ± 12 years; P < .01). Both groups experienced statistically significant improvement in iHOT-12 scores from baseline to final follow-up (P < .001); however, patients with labral degeneration reported inferior 2-year iHOT-12 scores when compared with patients without degeneration (P < .001). In the logistic regression models, labral degeneration was a significant negative predictor of achieving iHOT-12 minimal clinically important difference (odds ratio [OR] 0.47; 95% confidence interval [95% CI] 0.28-0.79), patient acceptable symptom state (OR 0.50; 95 CI 0.32-0.77), and substantial clinical benefit (OR 0.58; 95% CI 0.37-0.89). CONCLUSIONS: The results of our study conclude that patients with nondegenerative labral tissue at the time of repair have superior patient-reported outcomes at mid-term follow-up. The presence of labral degeneration was a negative predictor of achieving clinically significant thresholds after controlling for patient age, body mass index, sex, and baseline iHOT-12 scores. LEVEL OF EVIDENCE: III, retrospective comparative prognostic trial.

Acetabular Cartilage Lesions Predict Inferior Mid-Term Outcomes for Arthroscopic Labral Repair and Treatment of Femoroacetabular Impingement Syndrome.

PURPOSE: To analyze the effect of acetabular chondrosis at a minimum of 2 years following hip arthroscopy in patients undergoing labral repair and treatment of femoroacetabular impingement. METHODS: From 2014 to 2017, patients undergoing arthroscopic labral repair were prospectively enrolled in a multicenter hip arthroscopy registry. The registry was retrospectively queried for primary labral repair patients with complete 2-year outcomes and a Tonnis grade of less than 2. Patients were grouped according to severity of articular cartilage damage noted intraoperatively using the Beck classification system: none, low-grade (Grade 1 or 2), or high-grade (Grade 3 or 4) damage. A Kruskal-Wallis test and post hoc Dunn's test with Holm correction compared 2-year postoperative outcome scores of the iHOT-12 scale between groups. The proportion of patients in each cohort who achieved the clinically significant thresholds of the minimum clinically important difference (MCID), patient-acceptable symptom scale, and substantial clinical benefit (SCB) were analyzed. Multivariate logistic regression models identified predictors of achieving clinical thresholds while controlling for demographic variation. RESULTS: 422 patients met inclusion criteria, from which 347 completed 2-year outcomes. All groups experienced improvement in iHOT-12 scores from baseline to follow-up (P < .001). iHOT-12 scores at follow-up were inferior for Low-Grade Damage and High-Grade Damage Groups relative to the No Damage Group (P = .04; P = .03). When accounting for age, body mass index, gender, and preoperative iHOT-12 scores in logistic regression models, the presence of high-grade lesions was a negative predictor for achieving SCB (OR [95% CI], 0.54 [0.29-0.96]) and low-grade lesions a negative predictor for achieving MCID (0.50 [0.27-0.92]. Among patients with high-grade lesions, there was no significant difference in 2-year iHOT-12 scores between those undergoing chondroplasty (n = 50) and those undergoing microfracture (n = 14) (P = .14). CONCLUSIONS: Acetabular cartilage damage portends inferior patient-reported outcomes 2 years after primary labral repair and treatment of femoroacetabular impingement. The presence of cartilage lesions was a negative predictor of individual achievement of several clinical thresholds. LEVEL OF EVIDENCE: III, Retrospective comparative cohort.

Multicenter Outcomes After Primary Hip Arthroscopy: A Comparative Analysis of Two-Year Outcomes After Labral Repair, Segmental Labral Reconstruction, or Circumferential Labral Reconstruction.

PURPOSE: (1) To report minimum 2-year follow-up patient-reported outcome measures in patients undergoing labral repair (LR), segmental labral reconstruction (SLR), or circumferential labral reconstruction (CLR) in the primary setting; and (2) to compare minimum 2-year follow-up patient-reported outcome measures among these groups. METHODS: A retrospective review of a prospectively maintained multicenter database of patients undergoing hip arthroscopy was performed. Inclusion criteria were patients undergoing hip arthroscopy for treatment of labral tear and femoroacetabular impingement syndrome between January 2014 and October 2017, and completion of minimum 2-year postoperative outcome scores. Exclusion criteria were patients undergoing revision hip surgery, labral treatment limited to debridement, lateral center-edge angle <20°, osteoarthritis (Tönnis grade > 1), slipped capital femoral epiphysis, workers compensation status, and patients undergoing concomitant gluteus medius and/or minimus repair. Labral reconstruction patients were matched (1:3) with labral repair patients on age, sex, and body mass index. The labral reconstruction group was further stratified into SLR, and CLR groups. Patient demographic characteristics and clinical outcomes including Hip Outcome Score - Activities of Daily Living, Hip Outcome Score - Sport Subscale, modified Harris Hip Score, international Hip Outcome Tool, and visual analog scale for pain were analyzed, as well as achievement of the minimal clinical improvement difference (MCID). A P-value less than .05 indicated statistical significance. RESULTS: A total of 416 patients were included (LR, n = 312; SLR, n = 53; CLR, n = 51). The age, body mass index, and sex of the matched cohort were 42.3 ± 11.2 years, 24.7 ± 3.7, and 55.0% female. At a minimum of 2-year after hip arthroscopic surgery, no differences were found in preoperative, postoperative, or the delta visual analog scale for pain, modified Harris Hip Score, Hip Outcome Score - Activities of Daily Living, Hip Outcome Score - Sport Subscale, or international Hip Outcome Tool. Subsequently, the proportion of patients achieving the MCID and the PASS at latest follow-up were analyzed. This analysis revealed that no significant differences in the rate of MCID or PASS achievement for any outcome measure existed based on labral treatment. CONCLUSIONS: In this multicenter study on labral treatment in the primary setting, patients undergoing LR, SLR, and CLR demonstrated no difference in preoperative or postoperative scores, nor the proportion of patients achieving clinically significant outcome improvement. LEVEL OF EVIDENCE: III; therapeutic outcome study with controls.

Tenotomy for Iliopsoas Pathology is Infrequently Performed and Associated with Poorer Outcomes in Hips Undergoing Arthroscopy for Femoroacetabular Impingement.

PURPOSE: The purpose of this article was to report prevalence of iliopsoas pathology in patients undergoing hip arthroscopy for femoroacetabular impingement (FAI), incidence of rendered tenotomy, and outcomes of hips with iliopsoas involvement compared with those with primary FAI. METHODS: A cohort study from a hip arthroscopy study group using a prospectively-collected multicenter database was performed. Patients who underwent isolated hip arthroscopy for FAI from January 2016 to March 2017 were assigned to the Iliopsoas group (defined as preoperative diagnosis of coxa saltans internus, intraoperative anteroinferior labral bruising or tear, and preoperative positive psoas injection) or control group. The prevalence of iliopsoas pathology, radiographic and intraoperative findings, and rendered procedures between groups were compared. Mean 2-year (minimum 1.8 year) outcomes of iliopsoas groups with and without rendered tenotomy and a control group were compared. RESULTS: There were 1393 subjects, of which 92 (7%) comprised the iliopsoas study group with 1301 subjects control subjects. Sixteen subjects in the iliopsoas group received tenotomy (17% of iliopsoas group, 1% of all subjects), whereas 76 subjects (83% of iliopsoas group) with iliopsoas involvement did not. There was significant effect on postoperative International Hip Outcome Tool-12 (iHOT-12) scores based on iliopsoas involvement and treatment, F(2,1390) = 3.74, P = .02. Compared with the control group (M = 73, standard deviation [SD] = 24), the non-tenotomized iliopsoas group (M = 69, SD = 32) had similar postoperative scores (P = .46), whereas the tenotomized iliopsoas group (M = 57, SD = 28) averaged lower postoperative scores (P = .03). In the tenotomy group, 25% achieved the iHOT-12 substantial clinical benefit and patient acceptable symptomatic state value for normal function and 100% satisfaction, compared to 49% and 41% for the without tenotomy and control groups. CONCLUSIONS: Tenotomy in patients with iliopsoas pathology undergoing arthroscopic surgery for FAI is infrequently performed and is associated with poorer outcomes. Co-afflicted patients treated without tenotomy have similar successful outcomes to patients with primary FAI. Indiscriminate tenotomy for iliopsoas pathology in this setting should be cautiously considered. LEVEL OF EVIDENCE: Level III, cohort study.

Editorial Commentary: A-version to a Pain in the Butt-Structural and Dynamic Determinants of Posterior Hip Pain.

Ischiofemoral impingement is becoming a more recognized source of buttock pain that occurs as the lesser trochanter of the femur approximates the lateral margin of the ischium. Abnormal bony structure and alignment of the hip joint and/or faulty dynamic movement patterns may decrease the ischiofemoral space and compress the structures that are found within the space, including the quadratus femoris, proximal hamstring tendons, and sciatic nerve. The ischiofemoral space is reduced by structural factors including an increase in femoral anteversion and femoral neck angle. Dynamic assessment of the hip region may include the Craig test and total rotational range of motion of the hip joint, as well as the ischiofemoral impingement test and the long-stride walking test. The combination of structural and dynamic assessment of the hip region may help determine the presence of ischiofemoral impingement and direct appropriate management of the condition.

Unique Substantial Clinical Benefit Values for the 12-Item International Hip Outcome Tool Based on Preoperative Level of Function.

PURPOSE: To define unique substantial clinical benefit (SCB) values for improvement on the 12-item International Hip Outcome Tool (iHOT-12) based on a preoperative self-rating of function in patients undergoing hip arthroscopy for intra-articular pathology. METHODS: This was a retrospective review of prospective collected data on patients having hip arthroscopy for labral and chondral pathology and femoroacetabular impingement. On preoperative assessment and 1-year (+/-1 month) follow-up, subjects completed the iHOT-12 and a self-categorical rating of function ("severely abnormal," "abnormal," "nearly normal," or "normal"). Separate receiver operator characteristic analyses were performed for each preoperative categorical self-rating of function to determine unique SCB values for improvement-based changes in self-rating of function. RESULTS: Of 1034 eligible patients, 733 (71%) subjects met the inclusion criteria. Subjects consisted of 537 (73%) female and 196 (27%) male subjects with a mean age of 35.3 years (standard deviation 13). At a mean of 352 (standard deviation 21) days postsurgery, changes in iHOT-12 scores of 22, 28, and 27 points were associated with acceptable accuracy in identifying those who had an improved function rating when reporting a "severely abnormal," abnormal," and "nearly normal" rating on preoperative assessment, respectively. The accuracy of these SCB values in predicting improvement was different depending on the patient's preoperative rating of function. The accuracy of the SCB values in predicting improvement in those who had a "nearly normal" rating of function was not as accurate (area under the curve = 0.73) compared with those who had a "severely abnormal" or "abnormal" rating of function on preoperative assessment (area under the curve = 0.89; 0.89). CONCLUSIONS: This study provides surgeons with unique SCB values for the iHOT-12 based on a preoperative rating function and may allow for a more precise interpretation of score changes. SCB values of 22, 28, and 27 points on the iHOT-12 at 1-year (+/-1 month) follow-up identified those who had an improved function rating, when reporting a "severely abnormal," abnormal," and "nearly normal" rating on preoperative assessment, respectively. LEVEL OF EVIDENCE: III, retrospective comparative study.

Risk of intra-articular hip injury in adolescent athletes: a five-year multicentre cohort study.

PURPOSE: The purpose of the current study was to establish a risk stratification for hip injury by presenting the classification of sports among adolescent athletes undergoing hip arthroscopy. METHODS: A multicentre registry was queried to examine the incidence of adolescent athletes undergoing hip arthroscopy. Patients were identified and grouped according to their sport-specific risk classification (level I-III). Chi-square analysis was performed to determine the relationship of classification of sport and gender in adolescent athletes to hip arthroscopy. A second chi-square analysis was performed to determine the relationship of classification of sport and number of sports the adolescent athlete was participating in prior to arthroscopic hip surgery. RESULTS: A total of 297 adolescent athletes were included in the study with 129 (43.4%) participating in level I sports compared with 84 (28.3%) in level II and 84(28.3%) in level III sports. Chi-square testing demonstrated a significant effect on gender and sport classification, X2 (2, N = 297) = 31.18, p < 0.01. There was a greater percentage of athletes participating in a single sport (65.3%) compared with multiple sports (34.6%), but was not statistically significant, X2 (1, N = 297) = 1.88, p = 0.17. CONCLUSION: The current study was successful in stratifying a large, multicentre cohort of adolescent athletes requiring hip arthroscopy based on classification levels of sport. There were more male athletes participating in level I sports, while more female athletes participated in level II and level III sports.

Minimal Clinically Important Difference and Substantial Clinical Benefit Values for a Pain Visual Analog Scale After Hip Arthroscopy.

PURPOSE: To define minimal clinically important difference (MCID) and substantial clinical benefit (SCB) values for a pain visual analog scale (VAS) in patients undergoing hip arthroscopy for femoroacetabular impingement or chondrolabral pathology. METHODS: This was a retrospective review of prospective collected data on patients having hip arthroscopy for femoroacetabular impingement and/or chondrolabral pathology. On initial assessment and follow-up between 335 and 395 days postsurgery, subjects completed a pain VAS and categorical self-rating of function. MCID was calculated using one-half the standard deviation (SD) of the change in 1-year pain VAS values. Receiver operator characteristic analysis was performed to determine SCB values. A change in SCB value was determined based on change in categorical self-rating of function to create "improved" and "not improved" groups. Absolute postoperative SCB scores were calculated to determine scores that would be associated with "normal" or "abnormal" function ratings. RESULTS: Of 1,034 eligible patients, 733 (71%) met the inclusion criteria, with 537 (73%) women and 196 (27%) men having a mean age of 35.3 years (SD 13). At a mean of 352 (SD 21) days postsurgery, 536 (73%) were in the improved group and 197 (27%) in the not improved group. MCID was -15.0 mm. A change of -22.7 mm on the pain VAS was able to identify those that improved with high sensitivity (0.74) and specificity (0.63). Values of ≤10.4 mm and ≥29.0 mm were cutoffs identifying subjects that rated their function as normal or abnormal, respectively, with high sensitivity (0.79 and 0.76) and specificity (0.88 and 0.76). CONCLUSIONS: This study provides surgeons with information to help interpret pain VAS values at a follow-up period ranging from 335 to 395 days with MCID and SCB values of -15.0 mm and -22.7 mm, respectively. Additionally, a patient who assesses a pain level at ≤10.4 mm is likely to have a normal rating of function, whereas a patient who assesses a pain level at ≥29.0 mm is likely to have an abnormal rating of function. LEVEL OF EVIDENCE: III, retrospective comparative study.

The Patient Acceptable Symptomatic State of the 12-Item International Hip Outcome Tool at 1-Year Follow-Up of Hip-Preservation Surgery.

PURPOSE: To determine the patient acceptable symptomatic state (PASS) cutoff score for the 12-item International Hip Outcome Tool (iHOT-12) for patients after hip-preservation surgery. METHODS: A multicenter hip arthroscopy registry containing deidentified patient data was analyzed to discriminate patients who achieved satisfactory results from patients who did not. Patients eligible for inclusion in the study were between 18 and 75 years of age, consented to undergo elective hip arthroscopy, and completed preoperative patient-reported outcome questionnaires. A receiver operating characteristic analysis was performed to determine the PASS cutoff score for the iHOT-12 at 1 year after surgery based on the sensitivity and specificity of achieving satisfaction with surgery. A visual analog scale rating patient satisfaction 1 year after surgery was documented and compared between subjects who achieved the PASS score for the iHOT-12 and those who did not achieve it through an independent t test with an a priori α set at .05. RESULTS: A total of 647 subjects (66% women) aged between 18 and 73 years (mean, 36.5 years; standard deviation [SD], 12.0 years) were included in the study. A cutoff score of 75.2 for the iHOT-12 yielded a sensitivity of 0.91 and specificity of 0.81. Satisfaction averaged 89.5% (SD, 18.0%) for the patients with iHOT-12 scores greater than the PASS cutoff score versus 60.9% (SD, 30.61%) for those who did not achieve the PASS iHOT-12 score. CONCLUSIONS: The PASS cutoff score of 75.2 for the iHOT-12 establishes a "minimal" target score at which the patient is highly likely to be satisfied with the physical state of his or her hip joint at 1 year after hip arthroscopy. LEVEL OF EVIDENCE: Level III, case-control study.

Arthroscopic Outcomes as a Function of Acetabular Coverage From a Large Hip Arthroscopy Study Group.

PURPOSE: To report comparative hip arthroscopic outcomes of patients with low (borderline dysplasia), normal, and high (global pincer femoroacetabular impingement [FAI]) lateral acetabular coverage. METHODS: A retrospective analysis of prospectively collected data from a multicenter registry was performed. Primary hip arthroscopy patients were assigned to 1 of 3 groups based on preoperative lateral center-edge angle: borderline dysplasia (≤25°), normal (25.1°-38.9°), and pincer (≥39°). Repeated-measures analysis of variance compared preoperative with 2-year minimum postoperative International Hip Outcome Tool (iHOT-12) scores. Subsequent analysis of variance determined the effect of acetabular coverage on magnitude of change in scores. RESULTS: Of 437 patients, the only statistical difference between groups was a lower prevalence of acetabuloplasty in the borderline dysplasia group (P = .001). A significant improvement in the preoperative to postoperative iHOT-12 scores for patients with normal acetabular coverage, acetabular undercoverage, and acetabular overcoverage was observed: F(1, 339) = 311.06; P <.001, with no statistical differences in preoperative (P = .505) and postoperative (P <.488) iHOT-12 scores when comparing the groups based on acetabular coverage. Mean iHOT-12 scores increased from 37.3 preoperatively to 68.7 postoperatively (P <.001) in the borderline dysplasia group, from 34.4 to 72 (P <.001) in the normal coverage group, and from 35.3 to 69.4 (P <.001) in the pincer group. These preoperative scores increased by 31.4, 37.8, and 34.1, respectively, with no effect for acetabular coverage on the magnitude of change from preoperative to postoperative iHOT-12 scores: F(2,339) = 1.18; P = .310. Ten patients (2.3%) underwent conversion arthroplasty, and 19 patients (4.4%) underwent revision arthroscopy with no significant effect of acetabular coverage on the incidence of revision or conversion surgery: χ2 (6,433) = 11.535; P = .073. CONCLUSIONS: Lateral acetabular coverage did not influence outcomes from primary hip arthroscopy when performed in patients with low (borderline dysplasia), normal, and high (global pincer FAI) lateral center-edge angle. Borderline dysplasia and moderate global pincer FAI with no or minimal osteoarthritis do not compromise successful 2-year minimum outcomes or survivorship following primary hip arthroscopy when performed by experienced surgeons. LEVEL OF EVIDENCE: Level III, retrospective therapeutic trial.

Minimal Clinically Important Difference and Substantial Clinical Benefit Values for the 12-Item International Hip Outcome Tool.

PURPOSE: To define minimal clinically important difference (MCID) and substantial clinical benefit (SCB) values for the 12-item International Hip Outcome Tool (iHOT-12) in patients undergoing hip arthroscopy for intra-articular pathology. METHODS: This was a retrospective review of prospectively collected data on patients who underwent hip arthroscopy. On initial assessment and follow-up between 335 and 395 days after surgery, subjects completed the iHOT-12 and a categorical self-rating of function (severely abnormal, abnormal, nearly normal, or normal). One-half the standard deviation (SD) of the change in 1-year iHOT-12 scores was used to calculate the MCID. Receiver operator characteristic analysis was performed to determine SCB values. A change in SCB value was determined based on an improvement in the categorical rating of function. Absolute postoperative SCB scores were calculated to determine scores that would be associated with normal function ratings or with abnormal or severely abnormal function ratings. RESULTS: Of 1,034 eligible patients, 733 (71%) met the inclusion criteria. The subjects consisted of 537 female patients (73%) and 196 male patients (27%), with a mean age of 35.3 years (SD, 13 years). At a mean of 352 days (SD, 21 days) after surgery, 536 patients (73%) were in the "improved" group and 197 (27%) were in the "not improved" group. The MCID was 13 points. An SCB change score of 28 points was able to identify patients who improved with high sensitivity (0.79) and specificity (0.72). Scores of 86 points or greater and 56 points or less were the cutoff values found to identify subjects who rated their function as normal and abnormal, respectively, with high sensitivity (0.74 and 0.90, respectively) and specificity (0.82 and 0.86, respectively). CONCLUSIONS: This study provides information to help interpret iHOT-12 scores for a follow-up period ranging between 335 and 395 days with MCID and SCB values of 13 and 28 points, respectively. In addition, a vpatient who scored 86 points or better was likely to have a normal rating of function, whereas a patient with a score of 56 points or less was likely to have an abnormal rating of function. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Hip Dysplasia: Prevalence, Associated Findings, and Procedures From Large Multicenter Arthroscopy Study Group.

PURPOSE: To report observational findings of patients with acetabular dysplasia undergoing hip arthroscopy. METHODS: We performed a comparative case series of multicenter registry patients from January 2014 to April 2016 meeting the inclusion criteria of isolated hip arthroscopy, a documented lateral center-edge angle (LCEA), and completion of preoperative patient-reported outcome measures. A retrospective analysis compared range of motion, intra-articular pathology, and procedures of patients with dysplasia (LCEA ≤25°) and patients without dysplasia (LCEA >25°). RESULTS: Of 1,053 patients meeting the inclusion criteria, 133 (13%) had dysplasia with a mean LCEA of 22.8° (standard deviation, 2.4°) versus 34.6° (standard deviation, 6.3°) for non-dysplasia patients. There were no statistically significant differences in preoperative modified Harris Hip Score, International Hip Outcome Tool-12 score, or visual analog scale score (pain). Cam deformity occurred in 80% of dysplasia patients. There was a significant difference in internal rotation between the dysplasia (21°) and non-dysplasia groups (16°, P < .001). Mean internal rotation (33.5°; standard deviation, 15.6°) of the dysplastic subjects without cam morphology was greater than that of the dysplastic patients with cam morphology (18.5°; standard deviation, 11.6°; P < .001). Hypertrophic labra were found more commonly in dysplastic (33%) than non-dysplastic hips (11%, P < .001). Labral tears in patients with dysplasia were treated by repair (76%), reconstruction (13%), and selective debridement (11%); labral treatments were not significantly different between cohorts. The most common nonlabral procedures included femoroplasty (76%) and synovectomy (73%). There was no significant difference between the dysplasia and non-dysplasia groups regarding capsulotomy types and capsular closure rates (96% and 92%, respectively). CONCLUSIONS: Dysplasia, typically of borderline to mild severity, comprises a significant incidence of surgical cases (13%) by surgeons performing high-volume hip arthroscopy. Despite having similar preoperative pain and functional profiles to patients without dysplasia, dysplasia patients may have increased flexed-hip internal rotation. Commonly associated cam morphology significantly decreases internal rotation. Arthroscopic labral repair, femoroplasty, and closure of interportal capsulotomy are the most commonly performed procedures. LEVEL OF EVIDENCE: Level III, therapeutic comparative case series.

Sex-Dependent Differences in Preoperative, Radiographic, and Intraoperative Characteristics of Patients Undergoing Hip Arthroscopy: Results From the Multicenter Arthroscopic Study of the Hip Group.

PURPOSE: To compare preoperative, radiographic, and intraoperative findings between male and female patients undergoing hip arthroscopy. METHODS: We performed a retrospective review of a multicenter registry of patients undergoing hip arthroscopy between January 2014 and January 2017. Perioperative data from patients who consented to undergo surgery and completed preoperative patient-reported outcome questionnaires were analyzed to determine the effect of sex on preoperative symptoms, patient-reported outcomes, radiographic measures, and surgical procedures. RESULTS: A total of 1,437 patients (902 female and 535 male patients) with a mean age of 34 years were enrolled in the study. Female patients reported greater pain preoperatively on a visual analog scale (55.42 vs 50.40, P = .001) and deficits in functional abilities as per the modified Harris Hip Score (53.40 vs 57.83, P < .001) and International Hip Outcome Tool 12 (31.21 vs 38.51, P = .001) than male patients. There was a significant difference in the alpha angle (67.6° in male patients vs 59.5° in female patients, P < .001) corresponding with a higher prevalence of cam deformity in male patients (94.6% vs 84.5%, P < .001). Male patients had less range of motion in flexion (-5.67°, P < .001), internal rotation (-8.23°, P < .001), and external rotation (-4.52°, P < .001) than female patients. Acetabular chondroplasty was performed in 58% of male patients versus 40.2% of female patients (P < .001). Acetabuloplasty was performed in 59.1% of male patients versus 43.9% of female patients (P < .001). CONCLUSIONS: Male and female patients undergoing hip arthroscopy differ statistically in terms of preoperative hip function, hip morphology, and self-reported functional deficits, as well as the prevalence of surgical procedures. However, they do not differ significantly in terms of symptom localization, duration, or onset. The observed differences in preoperative functional scores between sexes, although statistically significant, may not represent clinically meaningful differences. LEVEL OF EVIDENCE: Level III, retrospective cross-sectional study.

Ischiofemoral impingement: defining the lesser trochanter-ischial space.

PURPOSE: The purpose of this study was to define changes in the ischial-lesser trochanteric space associated with medial and lateral hip rotation in neutral and 10° of extension and adduction. METHODS: Twenty-five hip joints from 14 embalmed cadavers (7 males and 7 females) were used for this study. The pelvic region of each cadaver was skeletonized, and the hip capsule released distally. With the hip joint in 0° flexion-extension/abduction-adduction, the distance between the lesser trochanter and ischium was measured in: neutral rotation, 40° medial rotation, and 60° lateral rotation. A one-way ANOVA with post hoc analysis determined the difference in the ischiofemoral space in these three positions. An additional position was then tested by laterally rotating the femur with the hip joint positioned in 10° extension and adduction. RESULTS: The average distance between the lesser trochanter and ischium was different (p < .0005) in neutral rotation, 40° medial rotation, and 60° lateral rotation at 2.8 cm (SD 1.1), 4.3 cm (SD 1.2), and 1.4 cm (SD 0.7), respectively. With the hip joint laterally rotated from a starting position of 10° extension and adduction, 21 of 25 (84 %) hips made contact between the lesser trochanter and ischium at an average position of 29° (SD 20) of lateral rotation. CONCLUSIONS: The lesser trochanter is closest to the ischium in lateral rotation and is furthest away in medial rotation when the hip is in neutral flexion-extension/abduction-adduction. The lesser trochanter approximates the ischium when the hip is laterally rotated in 10° extension and adduction. The information gained through this investigation helps to define the pathomechanics associated with ischiofemoral impingement and validate clinical tests to diagnose ischiofemoral impingement.

The effect of Astym® Therapy on muscle strength: a blinded, randomized, clinically controlled trial.

BACKGROUND: Astym(®) therapy is a manual therapy intervention used to stimulate tissue healing, decrease pain, improve mobility, and improve muscle performance associated with musculoskeletal pathology. The purpose of this study was to determine if Astym therapy administered to the lower extremity would result in an immediate change of maximal force output during a unilateral isometric squat test among individuals with a lower extremity injury. METHODS: Forty-five subjects (14 males; 31 females) between 18 and 65 years of age were randomized into 3 treatment groups: 1) Control group - received no treatment 2) Placebo group - received a sham Astym treatment 3) Astym therapy group- received Astym therapy to the lower extremity. A baseline measure of maximal force output (pre-test) during a unilateral isometric squat was performed. The subjects then received the designated treatment intervention. Immediately following the treatment intervention, maximal force output (post-test) was retested using identical testing procedures by an investigator who was blinded to the treatment intervention received by the subjects. The percent change of maximal force output from pre-test to post-test measures was compared using a one-way analysis of variance. A Tukey's post-hoc analysis determined the statistical differences between the groups. RESULTS: The treatment intervention had a significant effect on the percent change of maximal force output [F(2,42) = 7.91, p = 0.001]. Tukey's post hoc analysis demonstrated that the percent change of maximal force output was significantly greater in the Astym group (15 ± 18 % change of Newtons) compared to the placebo (-6 ± 11 % change of Newtons; p = 0.0001) and control (-1 ± 17 % change of Newtons; p = 0.0014) groups. No significant difference (p = 0.68) was noted between the control and placebo groups. CONCLUSIONS: Astym therapy to the involved lower extremity increased maximum force output during an isometric squat test immediately following treatment. The results of this study suggest that Astym therapy can immediately improve muscle performance (maximal force output) for patients presenting with muscular weakness caused by a lower extremity musculoskeletal injury. TRIAL REGISTRATION: Clinicaltrials.gov NCT02349230. Registered 23 January 2015.

Function of the ligamentum teres in limiting hip rotation: a cadaveric study.

PURPOSE: The purpose of this cadaveric study was to evaluate the function of the ligamentum teres (LT) in limiting hip rotation in 18 distinct hip positions while preserving the capsular ligaments. METHODS: Twelve hips in 6 fresh-frozen pelvis-to-toes cadaveric specimens were skeletonized from the lumbar spine to the distal femur, preserving only the hip ligaments. Hip joints were arthroscopically accessed through a portal located between the pubofemoral and iliofemoral ligaments to confirm the integrity of the LT. Three independent measurements of hip internal and external rotation range of motion (ROM) were performed in 18 defined hip positions of combined extension-flexion and abduction-adduction. The LT was then arthroscopically sectioned and rotation ROM reassessed in the same positions. A paired sample t test was used to compare the average internal and external hip rotation ROM values in the intact LT versus resected conditions in each of the 18 positions. P < .0014 was considered significant. RESULTS: A statistically significant influence of the LT on internal or external rotation was found in 8 of the 18 hip positions tested (P < .0014). The major increases in internal and external rotation ROM occurred when the hip was in 90° or 120° of flexion. CONCLUSIONS: The major function of the LT is controlling hip rotation. The LT functions as an end-range stabilizer to hip rotation dominantly at 90° or greater of hip flexion, confirming its contribution to hip stability. CLINICAL RELEVANCE: Ruptures of the LT contribute to hip instability dominantly in flexed hip positions.

Diagnostic accuracy of clinical tests for sciatic nerve entrapment in the gluteal region.

PURPOSE: The purpose of this study was to determine the diagnostic accuracy of the straight leg raise (SLR), active piriformis, and seated piriformis stretch tests in identifying individuals with sciatic nerve entrapment. METHODS: Thirty-three individuals (female = 25 and male = 8) with a mean age of 43 years (range 15-64; SD ± 11 years) were included in the study. Twenty-three subjects had endoscopic findings of sciatic nerve entrapment. Ten subjects without entrapment during endoscopic assessment were used as a control group. The results of the SLR, active piriformis, and seated piriformis stretch tests were retrospectively reviewed for each subject and compared between both groups. The accuracy of these tests for the endoscopic finding of sciatic nerve entrapment was determined by calculating the sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio. RESULTS: The SLR had sensitivity of 0.15, specificity of 0.95, positive likelihood ratio of 3.20, negative likelihood ratio of 0.90, and diagnostic odds ratio of 3.59. The active piriformis test had sensitivity of 0.78, specificity of 0.80, positive likelihood ratio of 3.90, negative likelihood ratio of 0.27, and diagnostic odds ratio of 14.40. The seated piriformis stretch test had sensitivity of 0.52, specificity of 0.90, positive likelihood ratio of 5.22, negative likelihood ratio of 0.53, and diagnostic odds ratio of 9.82. The most accurate findings were obtained when the results of the active piriformis test and seated piriformis stretch test were combined, with sensitivity of 0.91, specificity of 0.80, positive likelihood ratio of 4.57, negative likelihood ratio of 0.11, and diagnostic odds ratio of 42.00. CONCLUSIONS: The active piriformis and seated piriformis stretch tests can be used to help identify patients with and without sciatic nerve entrapment in the deep gluteal region.

A cadaveric model for ligamentum teres function: a pilot study.

PURPOSE: Despite the prevalence and clinical consequences of ligamentum teres pathology, its function is poorly understood. The purpose of this study was to help define the role the ligamentum teres may have in hip joint stabilization and determine whether a ball and string model could be used to describe the function of the ligamentum teres. METHODS: Eight embalmed cadavers were dissected to remove all soft tissue from around the hip, leaving only the ligamentum teres intact. Available hip abduction, adduction, medial rotation, and lateral rotation range of motion were measured for three repeated trials. The position of the ligamentum teres in relation to the femoral head was recorded at the endpoint position of these movements. RESULTS: An endpoint position as limited by the ligamentum teres for abduction, medial rotation, and lateral rotation was identified at a mean of 73°(SD 11°), 64°(SD 11°), and 58°(SD 10°), respectively. Hip adduction was limited by bony contact and therefore was not measured. The ligamentum teres wrapped around the femoral head to prevent inferior, posterior, and anterior subluxation with abduction, medial rotation, and lateral rotation, respectively. Repeated measures ANOVA indicated no significant difference in endpoint position based on trial number for the three movements (n.s.). CONCLUSION: The ligamentum teres consistently tightened to limit hip abduction, medial rotation, and lateral rotation. These results support a ball and string model for the femoral head and ligamentum teres. This information could be important for those with hip instability and ligamentum teres pathology.

Function of the ligamentum teres during multi-planar movement of the hip joint.

PURPOSE: The purpose of this study was to describe the orientation of the ligamentum teres and quantify the limb position when the ligamentum teres reached its endpoint during a simulated squat position in human cadavers. METHODS: Dissection of eight (4 male; 4 female) cadavers resulted in the complete removal of all soft tissue attachment of the femur to the acetabulum, leaving only the ligamentum teres intact. The limb was then moved into combined flexion and abduction of the hip joint to simulate a deep squat position until a ligamentous endpoint of the ligamentum teres was achieved. The orientation of the ligamentum teres in relation to the femoral head was described and the position of the limb relative to the sagittal plane (flexion) and frontal plane (abduction) was quantified. The mean, standard deviation, 95 % confidence intervals, and standard error of the measurement were calculated for the observed angles. RESULTS: Multi-planar movement of flexion and abduction moved the ligamentum teres into an anterior/inferior position relative to the femoral head and prevented the femoral head from anterior/inferior subluxation. The ligamentum teres endpoint was obtained at a combined average position of 100.6° (range 94°-112°; SD 5.5º; 95 % CI 96º-105º) and 20.0° (range 12°-32°; SD 7.0º; 95 % CI 14º-26º) flexion and abduction angle. CONCLUSIONS: The ligamentum teres formed a "sling-like" structure to support the femoral head inferiorly as the hip joint was moved into a combined position of flexion and abduction that resembled a squat position. The results help to define a possible role of the ligamentum teres in hip joint stability and possible mechanisms of injury.

Relationship of Average Outcomes Scores and Change in Status Requires Further Interpretation Between 1 and 2 Years Following Hip Arthroscopy.

BACKGROUND: Previous studies have demonstrated a clinically impactful change in patients between 1 and 2 years after hip arthroscopy. Assessment of differences in patient-specific factors between patients who remain the same and those who change (ie, either improve or decline) could provide valuable outcome information for orthopaedic surgeons treating those patients. PURPOSE: To identify patients who experienced change in functional status between 1 and 2 years after hip arthroscopy for femoroacetabular impingement syndrome and assess differences in patient-specific factors between those who improved, remained the same, or declined in functional status. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Prospectively collected data for patients who underwent hip arthroscopy at 1 of 7 centers were analyzed retrospectively at 1 year and 2 years postoperatively. Patients were categorized as "improved,""remained the same," or "declined" between 1- and 2-year follow-up based on the 12-item International Hip Outcome Tool (iHOT-12) minimal clinically important difference (MCID) value. A 1-way analysis of variance was used to assess differences in iHOT-12 scores, age, body mass index (BMI), alpha angle, and center-edge angle (CEA) between groups. Chi-square analyses were used to assess differences in the proportions of male and female patients in the outcome groups. RESULTS: The study included 753 patients (515 women and 238 men), whose mean ± SD age was 34.7 ± 12 years. Average 1-year (±1 month) and 2-year (±2 months) iHOT-12 scores for all patients were 73.7 and 74.9, respectively. Based on the calculated MCID of ±11.5 points, 162 (21.5%) patients improved, 451 (59.9%) remained the same, and 140 (18.6%) declined in status between 1- and 2-year follow-up. Those who improved between 1 and 2 years had lower 1-year iHOT-12 scores (P < .0005). We found no difference in age, BMI, alpha angle, CEA, or sex between groups (P > .05). CONCLUSION: Between 1- and 2-year follow-up assessments, 21.5% of patients improved and 18.6% declined in self-reported functional status. Those with iHOT-12 scores indicating abnormal function at 1 year improved beyond the MCID at 2 years follow-up. Thus, any decisions about the failure or success of arthroscopic hip procedures should not be made until at least the 2-year follow-up. Failing to thrive at 1-year follow-up may not accurately predict outcomes at year 2 or beyond. This could potentially decrease the perceived need for revision surgery in patients who do not thrive before 2-year follow-up.