The Effect of Rim Preparation, Labral Augmentation, and Labral Reconstruction on the Suction Seal of the Hip.

PURPOSE: To evaluate the biomechanical properties of the labral suction seal in the native labrum and after rim preparation, labral augmentation, and labral reconstruction. METHODS: Eight hemi-pelvises were dissected to the level of labrum and mounted for biomechanical testing. Each specimen was tested in axial distraction starting with the native labrum and then sequentially following rim preparation from 12 to 3 o'clock, labral augmentation, and segmental labral reconstruction using the iliotibial band allograft. In each condition, the specimens were compressed to 250 N and then distracted at 10 mm/s with force and displacement continuously recorded. Each test was repeated 3 times, and the mean peak force, displacement at peak force, and work were calculated. Data were reported as a percentage of the intact values to account for sex and size differences. Statistical testing was performed via a repeated-measures analysis of variance with a post hoc Tukey analysis. RESULTS: Peak loads occurred within 2.21 to 3.11 mm of displacement. The mean peak force, displacement at peak force, and work relative to the intact condition were the following: rim preparation (91.1% ± 8.5%, 94.4% ± 14.3%, 93.4% ± 23.5%, respectively), augmentation (66.1% ± 27.6%, 78.2% ± 16.3%, 55.7% ± 30.7%, respectively), and reconstruction (55.6% ± 25.7%, 64.7% ± 31.4%, 38.7% ± 27.2%, respectively). There was no significant difference in peak force following the rim preparation (P = .807), but peak force was significantly decreased after augmentation and reconstruction (P = .010 and P < .001, respectively). There was no significant difference in displacement at peak force following rim preparation or augmentation (P = .936 and P = .125, respectively), but displacement at peak force was significantly decreased after reconstruction (P = .005). The work from the suction seal was significantly less in both augmentation and reconstruction states compared to the intact labrum (P = .004 and P < .001, respectively) and rim preparation (P = .017 and P < .001, respectively). CONCLUSIONS: The results show that the suction seal is not significantly changed following rim preparation. Relative to the rim preparation, labral augmentation may re-create the labral suction seal better than labral reconstruction. CLINICAL RELEVANCE: This study provides a biomechanical basis for surgical decision making and clinical management of patients with labral tears of the hip.

Intraoperative Automated Radiographic Visualization Tool Allows for Higher Accuracy of Cam Lesion Resection When Used by Novice Surgeons for Arthroscopic Femoroplasty: Lowering the Learning Curve.

PURPOSE: To compare the accuracy of conventional fluoroscopy versus an intraoperative radiographic visualization tool in assisting a novice and experienced hip arthroscopist in comprehensive cam correction to a desired alpha angle (AA). METHODS: A cadaveric study was performed using 28 hemi-pelvises with cam-type deformity (AA > 55˚) measured on anteroposterior, lateral, and Dunn-view radiographs. Two fellowship-trained hip arthroscopists each performed 14 arthroscopic femoroplasties. The specimens were randomly assigned: 14 of the procedures were performed by the experienced surgeon, with 7 using the automated radiographic visualization tool (Guided Femoroplasty) and 7 using routine fluoroscopy (Control). The same number of hips was assigned to the novice surgeon, completing 7 femoroplasties with and without the visualization tool. Each hip was imaged before and after femoroplasty in 6 different positions using intraoperative fluoroscopy to evaluate head-neck offset. Femoroplasty AAs were compared between groups with and without visualization tool use, as well as between surgeons. One-way analysis of variance analysis was performed to evaluate the consistency of cam resection. RESULTS: For the experienced hip arthroscopist, comparison of Guide Femoroplasty and Control groups resulted in similar accuracy when compared to the controls, with post-femoroplasty AA averages ranging from 41.4° ± 3.8˚ to 44.8° ± 2.8˚ (P = .511) and 40.2° ± 5.3˚ to 45.6° ± 2.2˚ (P = .225), respectively. For the novice hip arthroscopist, the Guided Femoroplasty group had higher accuracy, with post-femoroplasty AA averages ranging from 42.8° ± 2.6˚ to 46.1° ± 7.2˚(P = .689) with and 39.8° ± 3.1˚ to 51.9° ± 8.1˚ (P = .001) without the visualization tool. Comparison of procedure time did not show any statistically significant difference between the use of the radiographic visualization tool and controls for either surgeon (P > .05 for all). CONCLUSIONS: Femoroplasty with and without the use of automated radiographic visualization tool results in accurate cam resection when used by both the experienced and novice surgeon. However, higher accuracy was observed when resecting to a desired AA performed by a novice surgeon using the visualization tool. Additionally, use of the visualization tool did not result in longer procedure times for either surgeon. CLINICAL RELEVANCE: The impact of incomplete cam resections and over-resection on patient outcomes in the literature has led to the recent development of automated intraoperative radiographic visualization tools that allow for assistance of cam resection accuracy for the treatment of femoroacetabular impingement syndrome. This cadaveric study demonstrates that femoroplasty with the use of an intraoperative automated radiographic visualization tool may result in more accurate cam resections.

Machine Learning Algorithms Predict Clinically Significant Improvements in Satisfaction After Hip Arthroscopy.

PURPOSE: To develop machine learning algorithms to predict failure to achieve clinically significant satisfaction after hip arthroscopy. METHODS: We queried a clinical repository for consecutive primary hip arthroscopy patients treated between January 2012 and January 2017. Five supervised machine learning algorithms were developed in a training set of patients and internally validated in an independent testing set of patients by discrimination, Brier score, calibration, and decision-curve analysis. The minimal clinically important difference (MCID) for the visual analog scale (VAS) score for satisfaction was derived by an anchor-based method and used as the primary outcome. RESULTS: A total of 935 patients were included, of whom 148 (15.8%) did not achieve the MCID for the VAS satisfaction score at a minimum of 2 years postoperatively. The best-performing algorithm was the neural network model (C statistic, 0.94; calibration intercept, -0.43; calibration slope, 0.94; and Brier score, 0.050). The 5 most important features to predict failure to achieve the MCID for the VAS satisfaction score were history of anxiety or depression, lateral center-edge angle, preoperative symptom duration exceeding 2 years, presence of 1 or more drug allergies, and Workers' Compensation. CONCLUSIONS: Supervised machine learning algorithms conferred excellent discrimination and performance for predicting clinically significant satisfaction after hip arthroscopy, although this analysis was performed in a single population of patients. External validation is required to confirm the performance of these algorithms. LEVEL OF EVIDENCE: Level III, therapeutic case-control study.

Improvements in Sleep Quality Are Maintained at a Minimum of 2 Years Following Hip Arthroscopy for Femoroacetabular Impingement Syndrome.

PURPOSE: To present the results of a mid-term follow-up study on sleep quality at a minimum of 2 years after hip arthroscopy for femoroacetabular impingement syndrome. METHODS: Original inclusion criteria were consecutive patients undergoing primary hip arthroscopy for cam/pincer correction between March 1, 2017, and July 1, 2017, who did not respond to nonoperative management, whereas exclusion criteria were revision arthroscopy, gluteus medius repair, contralateral procedure during the follow-up period, and known sleep disorders. Patients who had followed up at 6 months were contacted at a minimum of 2 years following their surgery. In total, 37 of 55 (67.3%) were available for follow-up. New Pittsburgh Sleep Quality Index (PSQI) scores were obtained and compared with previously reported scores at preoperative and 6-month time points. The PSQI ranges from 0 to 21, with a score of ≥5 indicating poor sleep quality. Point biserial correlations and χ2 tests of associations were used to investigate associations between demographics, preoperative patient-reported outcome measures, and the incidence of poor sleep quality at 2 years postoperatively. RESULTS: Preoperatively, 94.5% of patients (52/55) had a PSQI of ≥5 with a mean PSQI score of 9.8 ± 4.2. Statistically significant improvements were observed at both 6 (PSQI: 2.2 ± 0.2, P < .001) and 24 months (PSQI: 4.3 ± 3.9) postoperatively compared to baseline (P < .001, both). The mean PSQIs at 2 years and 6 months postoperatively were not statistically different (P = .06). A total of 21.7% (10/46) of patients continued to experience poor sleep quality at 6 months postoperatively, whereas a total of 29.7% (11/37) did so at 2 years postoperatively (P = .36). No preoperative factors were associated with poor sleep quality (P > .05 all). CONCLUSIONS: The early improvements in sleep quality observed 6 months postoperatively from an original small cohort were maintained at a mean 2.8-year follow-up in those who responded. However, approximately 30% of hip arthroscopy patients still experience poor sleep quality. LEVEL OF EVIDENCE: IV, therapeutic case series.

Gender and Age-Specific Differences Observed in Rates of Achieving Meaningful Clinical Outcomes 5-Years After Hip Arthroscopy for Femoroacetabular Impingement Syndrome.

PURPOSE: To compare the impact of age and gender on achieving meaningful outcomes among minimum patients 5 years after undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAIS). METHODS: Consecutive patients undergoing hip arthroscopy for FAIS by a single fellowship-trained surgeon between January 2012 and October 2014 were analyzed. Study inclusion criteria included any patient undergoing primary hip arthroscopy for FAIS, with 5 years follow-up. Preoperative and 5-year postoperative functional scores were collected, including the Hip Outcome Score Activities of Daily Living Subscale (HOS-ADL), HOS-Sport Subscale (HOS-SS), modified Harris hip score (mHHS), and Visual Analog Scale for satisfaction. Patients were matched 1:1 by gender and age to compare outcomes between these 2 demographics. Minimal clinically important difference (MCID) and patient acceptable symptomatic state (PASS) were calculated for each functional measure and compared by gender and age. RESULTS: Of the 340 patients (70.5%) with 5 years' follow up, 150 were matched by gender and age into one of the following groups: female patients <30 years, female patients 30 to 45 years, female patients >45 years, male patients <30 years, male patients 30 to 45 years, and male patients >45 years of age. At minimum 5-year follow-up, all 6 groups demonstrated statistically significant improvement in the functional outcome score averages and pain (P < .001 for all). Both within gender and within age category analysis of postoperative functional scores did not demonstrate any statistical differences (P > .05). Analysis of achieving MCID and PASS demonstrated that females had higher rates of reaching the HOS-SS and mHHS threshold for achieving MCID as compared to their male counterparts (P < .05). Furthermore, patients <30 years old had higher rates of reaching the HOS-ADL and mHHS for achieving PASS when compared to patients >45 years old (P < .05). CONCLUSION: The majority of patients achieve clinically significant outcome improvement at 5-year follow-up after arthroscopic FAIS surgery. Females reach the mHHS threshold for achieving MCID at significantly higher rates than males. Patients <30 years of age achieved PASS on the HOS-ADL and mHHS threshold scores at higher rates than those >45 years old. LEVEL OF EVIDENCE: Level III, case-control study.

Editorial Commentary: Rehabilitation After Hip Arthroscopy-Bear in Mind the Bearing of Weight.

Hip arthroscopy is the surgical treatment of choice for the treatment of femoroacetabular impingement syndrome and hip labral tears. Current guidelines on postoperative rehabilitation protocols are based on expert opinion, and evidence-based protocols are scarce. Previously, a non-weight-bearing protocol for several weeks after surgery was thought to prevent axial-load damage to the newly repaired labrum. However, there is a trend toward using immediate weight bearing as tolerated for early joint mobilization and pressurization. Strict weight-bearing restrictions may not be as necessary as once thought. We recommend that the first phase of rehabilitation prioritize joint protection to prevent joint inflammation and tissue irritation with a gradual increase in mobility exercises to restore range of motion. However, rehabilitation protocols should be tailored to address specific surgical findings, procedures, patient characteristics, and athletic goals. It is wise to be more conservative in older patients with poor bone quality. Bearing in mind this caveat, weight-bearing restrictions after hip arthroscopy may not improve outcomes and instead may have the negative effect of preventing patients from re-establishing a normal gait pattern.

Athletic Pubalgia (Sports Hernia): Presentation and Treatment.

Often referred to as a "sports hernia" or "core muscle injury," athletic pubalgia is a common yet poorly defined athletic injury. It is characterized by abdominal and groin pain likely from weakening or tearing of the abdominal wall without evidence of a true hernia. Symptoms can appear acutely or insidiously, primarily as groin and lower abdominal pain that can radiate toward the perineum and proximal adductors. Pain is exacerbated by athletic activity such as kicking, cutting, and sprinting. The pubis acts as a pivot point between the abdominal musculature and lower-extremity adductors, and therefore, pain with palpation over the symphysis or its surrounding structures is typical in athletic pubalgia. Symptoms can be reproduced during a resisted sit-up or with a forced cough or sneeze. Clinical examination should include an evaluation of articular hip pathology to identify underlying femoroacetabular impingement syndrome. Magnetic resonance imaging can aid in ruling out other pathologies and identify specific findings including tears or strains of the ipsilateral rectus abdominis or adductor tendons. Lidocaine injections can be used to localize the source of the pain. First-line treatment consists of a period of rest and anti-inflammatories, followed by a course of focused physical therapy. If conservative therapy fails to allow an athlete to return to activity, a variety of open or laparoscopic surgical techniques can be used. The surgical principles include reattachment of the rectus abdominis and repair or reinforcement of the abdominal musculature in layers to re-create the inguinal ligament anatomy. At times, variations of pelvic floor repair are performed or the addition of an adductor tenotomy or repair is used concomitantly. Numerous studies report a high rate of return to play after surgical management. Diagnosis and appropriate treatment of coexisting femoroacetabular impingement syndrome are crucial to a successful return to athletic activity.

Patients With a Hypotrophic Labrum Achieve Similar Outcomes After Primary Labral Repair Compared With Patients With a Normal-Sized Labrum: A Matched Cohort Analysis of 346 Patients With Femoroacetabular Impingement Syndrome.

PURPOSE: To compare patient functional scores and rates of achieving minimum clinically important differences (MCID) and patient acceptable symptomatic state (PASS) between patients with a hypotrophic labrum with those with a normal labrum width at a minimum 1-year follow-up from arthroscopic treatment of femoroacetabular impingement syndrome. METHODS: Data from consecutive patients who underwent primary hip arthroscopy between November 2015 and July 2018 for the treatment of femoroacetabular impingement syndrome were analyzed. Baseline demographic data, preoperative patient-reported outcome measures (PROMs), and minimum 1-year PROMs, including Hip Outcome Score-Activities of Daily Living, Hip Outcome Score-Sports Subscale, modified Harris Hip Score, international Hip Outcome Tool 12 questions, and visual analog scale for pain and satisfaction were recorded. The labrum size was determined using an arthroscopic probe at the 12- to 2-o'clock position with a hypotrophic labrum being defined as <4 mm and normal labrum defined as having a width between 4 and 7 mm on the articular side. Patients with hypotrophic labrum were matched 1:1 by age and body mass index to patients with normal labrum width. RESULTS: A total of 346 patients were included in the study with an average age of 31.4 ± 11.9 and a majority being female (72.0%). There were 173 in each of the normal and hypotrophic groups. There were no significant differences seen in 1-year PROMs between the 2 groups (P > .05 for all). The normal labrum group achieved MCID at a rate of 75% to 84% and PASS at a rate of 51% to 70%. The hypotrophic labrum group achieved MCID at a rate of 70% to 85% and PASS at a rate of 57% to 71%. There were no significant differences in rates between each group (P > .05 for all). CONCLUSIONS: Patients with an intraoperative finding of labral hypotrophy achieve 1-year meaningful clinical outcome at the same rate as those with normal labral width following arthroscopic labral repair. LEVEL OF EVIDENCE: III, Case-control study.

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.

Preoperative Duration of Symptoms Is Associated With Outcomes 5 Years After Hip Arthroscopy for Femoroacetabular Impingement Syndrome.

PURPOSE: To determine the effect of the preoperative duration of femoroacetabular impingement syndrome (FAIS)-associated symptoms on clinical outcomes at a minimum of 5 years after hip arthroscopy. METHODS: We identified FAIS patients who underwent primary hip arthroscopy between January 2012 and January 2014 with a minimum of 5 years' follow-up. Patient demographic characteristics and clinical outcomes, comprising the Hip Outcome Score-Activities of Daily Living (HOS-ADL), Hip Outcome Score-Sports Subscale (HOS-SS), modified Harris Hip Score (mHHS), pain score, and satisfaction score, were analyzed. The minimal clinically important difference, patient acceptable symptomatic state, and substantial clinical benefit were calculated. Patients were stratified based on the preoperative duration of symptoms: less than 2 years versus 2 years or longer. Multivariate regressions were constructed to determine the association between the preoperative symptom duration and clinical outcomes at 5 years after hip arthroscopy. RESULTS: A total of 310 patients were included with a mean age (±standard deviation) of 34.1 ± 11.9 years and body mass index of 25.3 ± 5.1. The study group showed statistically significant improvements in the HOS-ADL, HOS-SS, mHHS, pain score, and satisfaction score (P < .001 for all). A preoperative duration of symptoms of 2 or more years was an independent predictor of worse HOS-ADL, HOS-SS, mHHS, and pain score (P < .05 for all). Furthermore, a longer duration of symptoms was associated with a lower likelihood of achieving the minimal clinically important difference for the HOS-ADL (odds ratio [OR], 0.53; P = .037), HOS-SS (OR, 0.38; P = .003), and mHHS (OR, 0.43; P = .009); the patient acceptable symptomatic state for the HOS-SS (OR, 0.44; P = .006) and mHHS (OR, 0.46; P = .006) but not the HOS-ADL despite trending toward significance (OR, 0.59; P = .098); and substantial clinical benefit for the HOS-ADL (OR, 0.50; P = .011), HOS-SS (OR, 0.52; P = .020), and mHHS (OR, 0.47; P = .007). CONCLUSIONS: Patients with a preoperative duration of FAIS-associated symptoms of 2 or more years prior to hip arthroscopy experience inferior outcomes and a lower frequency of clinically significant outcome improvement than patients with a shorter duration of symptoms at medium-to long-term follow-up. LEVEL OF EVIDENCE: Level III, retrospective comparative trial.

Defining Meaningful Functional Improvement on the Visual Analog Scale for Satisfaction at 2 Years After Hip Arthroscopy for Femoroacetabular Impingement Syndrome.

PURPOSE: To (1) define Substantial Clinical Benefit (SCB), Patient Acceptable Symptomatic State (PASS), and Minimal Clinically Important Difference (MCID) for the visual analog scale (VAS) Satisfaction in patients undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAIS), and (2) identify preoperative predictors of achieving each outcome end-point. METHODS: Data from consecutive patients who underwent primary hip arthroscopy between November 2014 and January 2017 were prospectively collected and retrospectively analyzed. Inclusion criteria consisted of patients with clinical and radiographic diagnosis of FAIS, who failed nonoperative treatment, underwent primary hip arthroscopy to address the FAIS, and had at minimum 2-year follow-up. Baseline data and postoperative patient-reported outcome scores were recorded at 2 years postoperatively. To quantify clinical significance of outcome achievement on the VAS)Satisfaction, we calculated MCID, PASS, and SCB for this outcome measure. A multivariate logistic regression analysis was used to identify preoperative predictors of achieving SCB, PASS, and MCID satisfaction. RESULTS: A total of 335 patients were included in the final analysis, with an average age and body mass index (BMI) of 32.8 (standard deviation ± 12.4) years and 25.2 (standard deviation ± 5.3), respectively, and the majority being female (69.3%). The values on the VAS satisfaction were identified to represent MCID, PASS, and SCB, respectively: 52.8, 80.9, and 89.7. The rates of achieving clinically significant improvement on the VAS Satisfaction was 85.6%, 68.1%, and 56.9% for MCID, PASS, and SCB, respectively. A larger preoperative alpha angle was predictive for achieving SCB (odds ratio [OR], 1.076; P = .046), whereas lower BMI (OR, 0.955; P = .047) and larger preoperative alpha angle (OR, 1.12; P = .025) were predictors for achieving PASS. CONCLUSIONS: This study identified threshold VAS satisfaction scores of 52.8, 80.9, and 89.7 for achieving MCID, SCB, and PASS, respectively, at 2-year follow-up following hip arthroscopy for FAIS. Furthermore, preoperative variables including larger preoperative alpha angles and lower BMI are predictors of achieving superior clinical satisfaction. LEVEL OF EVIDENCE: Level IV, Case Series.

Comparison of Suction Seal and Contact Pressures Between 270° Labral Reconstruction, Labral Repair, and the Intact Labrum.

PURPOSE: To biomechanically compare the suction seal, contact area, contact pressures, and peak forces of the intact native labrum, torn labrum, 12- to 3-o'clock labral repair, and 270° labral reconstruction in the hip. METHODS: A cadaveric study was performed using 8 fresh-frozen hemipelvises with intact labra and without osteoarthritis. Intra-articular pressure maps were produced for each specimen using an electromechanical testing system under the following conditions: (1) intact labrum, (2) labral tear, (3) labral repair between the 12- and 3-o'clock positions, and (4) 270° labral reconstruction using iliotibial band allograft. Specimens were examined in neutral position, 20° of extension, and 60° of flexion. In each condition, contact pressure, contact area, and peak force were obtained. Repeated-measures analysis of variance was used to identify differences in biomechanical parameters among the 3 conditions. Qualitative differences in suction seal were compared between labral repair and labral reconstruction using the Fisher exact test. RESULTS: Repeated-measures analysis of variance for contact area in neutral position, extension, and flexion showed statistically significant differences between the normalized study states (P < .05). Post hoc analysis showed significantly larger contact areas measured in labral repair specimens than in labral reconstruction specimens in the extension and flexion positions. Region-of-interest analysis for the normalized contact area in the extension and flexion positions, as well as normalized contact pressures in neutral position, showed statistically significant differences between the labral states (P < .05). Finally, 8 labral repairs (100%) versus only 1 labral reconstruction (12.5%) retained the manually tested suction seal (P < .001). CONCLUSIONS: In this in vitro biomechanical model, 270° labral reconstruction resulted in decreased intra-articular contact area and loss of suction seal when compared with labral repair. Clinically, labral reconstruction may not restore the biomechanical characteristics of the native labrum as compared with labral repair. CLINICAL RELEVANCE: Labral reconstruction may result in lower intra-articular hip contact area and loss of suction seal, affecting the native biomechanical function of the acetabular labrum. Further biomechanical studies and clinical studies are necessary to determine whether there are any long-term consequences of 270° labral reconstruction.

A Cadaveric Study of Cam-Type Femoroacetabular Impingement: Biomechanical Comparison of Contact Pressures Between Cam Morphology, Partial Femoral Osteoplasty, and Complete Femoral Osteoplasty.

PURPOSE: To compare the biomechanical properties of the hip joint with an intact femoral cam lesion, partial cam resection, and complete cam resection. METHODS: A cadaveric study was performed using 8 hemipelvises with cam-type morphology (alpha angle > 55°) and intact labra. Intra-articular pressure maps were produced for each specimen under the following conditions: (1) native cam morphology (intact), (2) cam morphology with incomplete resection (partial), and (3) cam morphology with complete resection (complete). By use of an open technique, resection of the superior portion of the cam morphology was performed with a 5.5-mm burr to create the partial resection, followed by the inferior portion to create the complete resection. In each condition, 3 biomechanical parameters were obtained: contact pressure, contact area, and peak force within a region of interest. Measurements were performed 3 times in each condition, and the average value was used for statistical analysis. Analysis of variance was used to compare biomechanical parameters between conditions. RESULTS: A statistically significant difference was found between the pre- and post-resection alpha angles (62.2° ± 3.9° vs 40.9° ± 1.4°, P < .001). Repeated-measures analysis of variance showed that the normalized average pressure values of hips with complete resection of cam lesions were significantly lower than those of hips with incomplete femoral cam lesions and hips with intact cam morphology (100% vs 93.6% ± 8.3% and 82.6% ± 16.2%, respectively; P < .0001). The percentage reduction of contact pressure in the complete and partial groups was 17.4% and 6.4%, respectively, compared with the intact group. Contact area and peak force showed no statistically significant differences across the 3 conditions (P > .05). CONCLUSIONS: Complete cam resection results in significantly lower intra-articular hip contact pressures than incomplete cam resection and native cam morphology in a cadaveric hip model. These observations underscore the importance of ensuring complete resection of femoral cam lesions in patients undergoing hip arthroscopy for femoroacetabular impingement syndrome. CLINICAL RELEVANCE: Previous studies have shown that the most common reason for revision hip arthroscopy in patients with femoroacetabular impingement syndrome is incomplete femoral cam resection during the index operation. This study shows biomechanical differences associated with partial cam resection compared with the complete cam resection state that may translate to persistent symptoms.

Nitromethane Exposure from Tobacco Smoke and Diet in the U.S. Population: NHANES, 2007-2012.

Nitromethane is a known toxicant and suspected human carcinogen. Exposure to nitromethane in a representative sample of the civilian, noninstitutionalized population in the United States ≥12 years old was assessed using 2007-2012 National Health and Nutritional Examination Survey (NHANES) data. Nitromethane was detected in all 8000 human blood samples collected, of which 6730 were used for analyses reported here. Sample-weighted median blood nitromethane was higher among exclusive combusted tobacco users (exclusive smokers; 774 ng/L) than nonusers of tobacco products (625 ng/L). In stratified sample-weighted regression analysis, smoking 0.5 pack of cigarettes per day was associated with a statistically significant increase in blood nitromethane by 150 ng/L, and secondhand smoke exposure (serum cotinine >0.05 ng/mL and <10 ng/mL) was statistically significant with a 31.1 ng/L increase in blood nitromethane. Certain dietary sources were associated with small but statistically significant increases in blood nitromethane. At median consumption levels, blood nitromethane was associated with an increase of 7.55 ng/L (meat/poultry), 9.32 ng/L (grain products), and 14.5 ng/L (vegetables). This is the first assessment of the magnitude and relative source apportionment of nitromethane exposure in the U.S. population.

Hip Instability in the Athlete: Anatomy, Etiology, and Management.

In this review, the recent literature evaluating the anatomic considerations, etiology, and management options for athletes with hip instability are investigated. Studies on the osseous, chondrolabral capsuloligamentous, and dynamic muscular contributions to hip stability are highlighted. Microinstability, iatrogenic instability, and femoroacetabular impingement-induced instability are discussed with a focus on demographic and outcomes research in athletes. Surgical techniques including both open and arthroscopic approaches are additionally evaluated.

Physical Examination of the Hip.

The hip and pelvis have a complex anatomy and are a common source of pain and injury in the athletic population. The clinical examination of the hip requires a systematic approach to differentially diagnose hip problems with overlapping pain referral patterns. Because of the complex anatomy of the hip, the physical examination is a comprehensive evaluation of the 4 main pain generators of the hip from deep to superficial: the osteochondral, capsulolabral, musculotendinous, and neurovascular elements of the hip. The hip examination begins with the standing examination and gait analysis followed by a seated, supine, lateral, and prone examination. A targeted physical examination used in conjunction with a layered understanding of the hip and pelvis can help guide diagnostic testing, distinguish hip-specific diagnoses from similar presenting pathologies, and inform treatment.

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.

Surgical Treatment of Labral Tears: Debridement, Repair, and Reconstruction.

Advances in hip preservation surgery have to lead to increased utilization of hip arthroscopy. With this, there has also been a growth in the understanding of various hip conditions, therefore, leading to an increase in hip conditions amenable to arthroscopic intervention. The acetabular hip labrum has been at the forefront of arthroscopic advances in the hip. The labrum is important for hip stability, provision of the suction seal, and joint proprioception. Given the labrum's central role in hip biomechanics, there is increasing emphasis on labral preservation in the form of debridement and repair. In revision settings, advanced techniques such as labral augmentation and reconstruction may play a role in the management of labral pathology. Appropriate management of the hip labrum at the time of surgery can be an important mediator of the outcome. As such, an understanding of the evolving evidence base and surgical indications and techniques are integral to the treatment and management of labral pathology.

Prolonged Postoperative Opioid Use After Arthroscopic Femoroacetabular Impingement Syndrome Surgery: Predictors and Outcomes at Minimum 2-Year Follow-up.

BACKGROUND: The association between prolonged postoperative opioid use on outcomes after hip preservation surgery is not known. PURPOSE: To compare minimum 2-year patient-reported outcomes (PROs) between patients who required ≥1 postoperative opioid refill after undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAIS) versus patients who did not require a refill and to identify preoperative predictors for patients requiring ≥1 postoperative opioid refill. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Data from consecutive patients who underwent arthroscopic surgery for FAIS between January 2012 and January 2017 were analyzed. Multivariate regression analysis was performed to classify patient and radiographic variables as predictive of requiring ≥1 opioid prescription refill after surgery. Patients completed the following PROs preoperatively and at 2-year follow-up: Hip Outcome Score- Activities of Daily Living subscale (HOS-ADL), HOS-Sports Subscale (HOS-SS), modified Harris Hip Score (mHHS), International Hip Outcome Tool (iHOT-12), and 100-point visual analog scale (VAS) for pain and satisfaction. Scores were compared between patients needing additional prescription opioids and those who did not. RESULTS: A total of 775 patients, of whom 141 (18.2%) required ≥1 opioid prescription refill, were included in the analysis. Patients requiring opioid refills had significantly lower 2-year postoperative PRO scores compared with patients not requiring refills: HOS-ADL (79.9 ± 20.3 vs 88.7 ± 14.9), HOS-SS (64.6 ± 29.5 vs 78.2 ± 23.7), mHHS (74.2 ± 21.1 vs 83.6 ± 15.9), iHOT-12 (63.6 ± 27.9 vs 74.9 ± 24.8), and VAS satisfaction (73.4 ± 30.3 vs 82.2 ± 24.9), as well as significantly more pain (26.8 ± 23.4 vs 17.9 ± 21.8) (P ≤ .001 for all). Predictors of requiring a postoperative opioid refill included patients with active preoperative opioid use (odds ratio, 3.12 [95% confidence interval, 1.06-9.21]; P = .039) and larger preoperative alpha angles (odds ratio, 1.04 [95% confidence interval, 1.01-1.07]; P = .03). CONCLUSION: Patients requiring ≥1 opioid prescription refill after hip arthroscopy for FAIS had lower preoperative and 2-year PRO scores when compared with patients not requiring refills. Additionally, active opioid use at the time of surgery was found to be predictive of requiring additional opioids for pain management.

Achievement of Meaningful Clinical Outcomes Is Unaffected by Capsulotomy Type During Arthroscopic Treatment of Femoroacetabular Impingement Syndrome: Results From the Multicenter Arthroscopic Study of the Hip (MASH) Study Group.

BACKGROUND: Capsule management has emerged as an important topic in the field of hip arthroscopy. The 2 most popular techniques are interportal capsulotomy and T-type capsulotomy, but few studies have compared outcomes between these 2 techniques. PURPOSE: To compare 2-year (±2 months) patient-reported outcomes (PROs) between patients who underwent interportal versus T-type capsulotomy during arthroscopic labral repair for femoroacetabular impingement syndrome (FAIS). STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A retrospective review of a large multicenter registry of patients undergoing arthroscopic hip preservation surgery for FAIS was performed. Data from 9 surgeons across 9 sites between January 2014 and February 2018 were included in the study. Baseline demographic data, preoperative PROs, and minimum 2-year postoperative PROs including Hip Outcome Score-Activities of Daily Living (HOS-ADL), HOS-Sports Subscale (HOS-SS), modified Harris Hip Score, and International Hip Outcome Tool-12 (iHOT-12) were recorded. Patients were divided into 2 groups based on whether interportal or T-type capsulotomy was performed according to the senior surgeon's preference and training, and all capsulotomies were then routinely repaired. The 2 groups were matched 1:1 by age, sex, and body mass index (BMI). Achievement of minimal clinically important difference (MCID), Patient Acceptable Symptomatic State (PASS), and substantial clinical benefit (SCB) was compared for the HOS-ADL, HOS-SS, and iHOT-12 between the 2 groups. RESULTS: The final analysis included 658 of 1483 eligible patients with a mean ± SD age of 32.6 ± 11.6 years and BMI of 24.0 ± 3.7; of these, 329 patients were treated via interportal capsulotomy, and 329 patients were treated via T-type capsulotomy. Female patients comprised 66.3% of the study population. Capsulotomy type was not a predictor of 2-year postoperative PROs on multivariate linear regression analysis when adjusted for covariates. Chi-square analysis showed no statistical difference in achievement of MCID, PASS, and SCB between the interportal and T-type groups for HOS-ADL (80.3%, 75.8%, 52.7% and 77.1%, 71.7%, 53.6%, respectively; P > .01 for all), HOS-SS (83.6%, 72.5%, 51.5% and 81.7%, 68.4%, 49.2%, respectively; P > .01 for all), and iHOT-12 (87.5%, 72.0%, 50.5% and 80.0%, 64.7%, 45.6%, respectively; P > .01 for all). CONCLUSION: Arthroscopic management of FAIS resulted in significant clinical improvement that was independent of capsulotomy type when the capsulotomy included repair.