A large-effect fitness trade-off across environments is explained by a single mutation affecting cold acclimation.

Identifying the genetic basis of local adaptation and fitness trade-offs across environments is a central goal of evolutionary biology. Cold acclimation is an adaptive plastic response for surviving seasonal freezing, and costs of acclimation may be a general mechanism for fitness trade-offs across environments in temperate zone species. Starting with locally adapted ecotypes of Arabidopsis thaliana from Italy and Sweden, we examined the fitness consequences of a naturally occurring functional polymorphism in CBF2. This gene encodes a transcription factor that is a major regulator of cold-acclimated freezing tolerance and resides within a locus responsible for a genetic trade-off for long-term mean fitness. We estimated the consequences of alternate genotypes of CBF2 on 5-y mean fitness and fitness components at the native field sites by comparing near-isogenic lines with alternate genotypes of CBF2 to their genetic background ecotypes. The effects of CBF2 were validated at the nucleotide level using gene-edited lines in the native genetic backgrounds grown in simulated parental environments. The foreign CBF2 genotype in the local genetic background reduced long-term mean fitness in Sweden by more than 10%, primarily via effects on survival. In Italy, fitness was reduced by more than 20%, primarily via effects on fecundity. At both sites, the effects were temporally variable and much stronger in some years. The gene-edited lines confirmed that CBF2 encodes the causal variant underlying this genetic trade-off. Additionally, we demonstrated a substantial fitness cost of cold acclimation, which has broad implications for potential maladaptive responses to climate change.

Post-Related Complications in Hip Arthroscopy Are Reported Significantly Greater in Prospective Versus Retrospective Literature: A Systematic Review.

PURPOSE: To determine whether there are differences in (1) the incidence of post-related complications following hip arthroscopy between prospective and retrospective publications; and (2) between post-assisted and postless techniques. METHODS: A systematic review was performed using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines to characterize post-related complications following hip arthroscopy for central or peripheral compartment hip pathology, including femoroacetabular impingement syndrome and chondrolabral injury. Inclusion criteria were prospective and retrospective Level I-IV evidence investigations that reported results of hip arthroscopy performed in the supine position. Exclusion criteria included open or extra-articular endoscopic hip surgery. Post-related complications included pudendal nerve injury (sexual dysfunction, dyspareunia, perineal pain or numbness) or perineum/external genitalia soft-tissue injury. RESULTS: Ninety-four studies (12,212 hips; 49% male, 51% female; 52% Level IV evidence) were analyzed. Prospective studies (3,032 hips) report a greater incidence of post-related complications compared with retrospective (8,116 hips) studies (7.1% vs 1.4%, P < .001). Three studies (1,064 hips) used a postless technique and all reported a 0% incidence of pudendal neurapraxia or perineal soft tissue injury. Most pudendal nerve complications were transient, resolving by 3 months, but permanent nerve injury was reported in 4 cases. Only 19%, 22%, 7%, and 4% of studies reported a total surgery time, traction time, traction force, and bed Trendelenburg angle for their study samples, respectively. CONCLUSIONS: The incidence of post-related complications is 5 times greater in prospective (versus retrospective) hip arthroscopy literature. Postless distraction resulted in a 0% incidence of post-related injuries. LEVEL OF EVIDENCE: IV, systematic review of Level I-IV evidence.

Worse Preoperative Pain and Higher Activity Levels Predict Patient Choice of Formal Physical Therapy After Primary Anterior Total Hip Arthroplasty.

BACKGROUND: The purpose of this randomized controlled trial is (1) to compare the efficacy of supervised formal physical therapy (PT) and self-directed home exercises and (2) to identify independent predictors of transitioning from self-directed home exercises to supervised formal PT following total hip arthroplasty (THA) via an anterior approach. METHODS: After Institutional Review Board approval, 147 patients undergoing primary unilateral THA through anterior approach were enrolled and randomized to receive either clinic or home-based PT. Surveys with Hip Disability Osteoarthritis Outcome Scores (HOOS) and Short Form-12 Health Survey scores for both groups were obtained before surgery and at 6, 14, and 24 weeks after surgery. Patients had the option to transition into the other study group at their 6-week follow-up visit. RESULTS: Of the 147 patients enrolled, final analysis included scores for 136 patients. Forty-two (63.6%) of the 66 patients randomized to the supervised formal PT group crossed over to self-directed home exercise group and 12 (17.1%) of the 70 patients randomized to the self-directed home exercise group crossed over to supervised formal PT group. There were no significant (P > .05) differences between groups at all time points for the overall HOOS and Short Form-12 Health Survey. Subjects with worse preoperative pain scores (P = .005) and higher HOOS preoperative activity of daily living scores (P = .015) were more likely to transition from the home exercise group to formal PT group. CONCLUSION: There were no significant outcome score differences between subjects undergoing supervised formal PT and self-directed home exercises. However, patients reporting worse preoperative pain and higher preoperative activity levels may prefer supervised formal PT compared to self-directed home exercises after undergoing primary anterior THA.

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.

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.

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.

Return to Sport Rates in Physically Active Individuals 6 Months After Arthroscopy for Femoroacetabular Impingement Syndrome.

CONTEXT: Six months is the expected time frame to return to sport (RTS) after hip arthroscopy for femoroacetabular impingement syndrome (FAIS). OBJECTIVE: The primary aims of this study were to (1) report the RTS rate of physically active individuals 6 months after arthroscopic surgery for FAIS and (2) compare the self-reported hip function between those who were able to RTS against those who had not. DESIGN: Cohort study. SETTING: The Ohio State University Wexner Medical Center. PATIENTS: A total of 42 physically active individuals scheduled for hip arthroscopy for FAIS. MAIN OUTCOME MEASURES: Self-reported function, including preinjury and current activity levels and ability to participate in sport, were collected on 42 individuals with FAIS prior to surgery and at 6-month follow-up. Participants were allocated into 2 groups based on self-reported RTS status at 6-month follow-up. Separate 2-way analyses of variance were used to test the interaction of groups (those who did/did not RTS). Main effects were reported in the absence of statistically significant interactions (P ≤ .05). RESULTS: Altogether, 28 of 42 participants (66%) returned for 6-month follow-up; 5 of the 14 participants (35.7%) lost to follow-up underwent contralateral hip surgery within the study time frame. At the 6-month follow-up, 16 of the remaining 28 participants (57.1%) reported that they had returned to sport, 5 of whom returned at their prior level of participation. There was no statistically significant interaction of group and time for either hip outcome score subscale (P ≥ .20). Self-reported hip function improved over time, regardless of group (P ≤ .001). Participants in the yRTS group demonstrated higher hip outcome score-sport scores than did the nRTS group, regardless of time (P = .04). CONCLUSIONS: Though just over half of participants returned to sport 6 months after hip arthroscopy for FAIS, only 18% returned to their previous level of sports participation. Participants who returned to sport reported better function than those who did not, but self-reported hip function improved over time regardless of group. The most commonly reported reasons for not returning to sport were weakness (69.6%), fear (65.2%), and pain (56.5%).

Preoperative Depression Is Negatively Associated With Function and Predicts Poorer Outcomes After Hip Arthroscopy for Femoroacetabular Impingement.

PURPOSE: (1) To determine the prevalence of depression in patients undergoing hip arthroscopy for the treatment of femoroacetabular impingement (FAI) syndrome and (2) to determine whether depression has a statistically significant and clinically relevant effect on preoperative and postoperative patient-reported outcome scores. METHODS: Consecutive subjects undergoing hip arthroscopy for FAI syndrome were retrospectively reviewed. The Beck Depression Inventory-II (BDI-II), Hip Outcome Score (HOS), and 33-item International Hip Outcome Tool (iHOT-33) were administered preoperatively and postoperatively. Clinically relevant differences were defined by the minimal clinically important difference, substantial clinical benefit, and patient acceptable symptom state. Comparisons between preoperative and postoperative scores were completed. The Spearman correlation coefficient (r) was used to determine the degree of correlation between the BDI-II score, HOS, and iHOT-33 score preoperatively and postoperatively. RESULTS: We analyzed 77 patients (72.7% female patients; mean age, 35.2 ± 12.5 years). Depressive symptoms were reported as minimal (75.3%), mild (11.7%), moderate (6.5%), or severe (6.5%). Patients with minimal or mild depression had a superior HOS Activities of Daily Living (Δ17.3 preoperatively [P < .001] and Δ37.8 postoperatively [P < .001]), HOS Sport-Specific Subscore (Δ12.8 preoperatively [P = .002] and Δ52.1 postoperatively [P < .0001]), and iHOT-33 score (Δ15.4 preoperatively [P < .0001] and Δ51.3 postoperatively [P < .0001]) compared with patients with moderate or severe depression. There was a weak to moderate negative correlation between the BDI-II score and iHOT-33 score (r = -0.4614, P < .0001 preoperatively; r = -0.327, P < .0001 at 1 year), HOS Activities of Daily Living (r = -0.531, P < .0001 preoperatively), and HOS Sport-Specific Subscore (r = -0.379, P < .0017 at 1 year). CONCLUSIONS: Most patients undergoing hip arthroscopy for FAI have minimal depressive symptoms with the overall prevalence higher than the general population. Patients with minimal or mild depressive symptoms have statistically and clinically better preoperative and postoperative patient-reported outcomes, are more likely to obtain substantial clinical benefit from surgery, and are more likely to reach a patient acceptable symptom state after surgery than patients with moderate to severe depressive symptoms. LEVEL OF EVIDENCE: Level III, case-control 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.

Origin of the direct and reflected head of the rectus femoris: an anatomic study.

PURPOSE: This study aimed to define the footprint of the direct and reflected heads of the rectus femoris and the relation of the anterior inferior iliac spine (AIIS) to adjacent neurovascular (lateral circumflex femoral artery and femoral nerve), bony (anterior superior iliac spine [ASIS]), and tendinous structures (iliopsoas). METHODS: Twelve fresh-frozen cadaveric hip joints from 6 cadavers, average age of 44.5 (±9.9) years, were carefully dissected of skin and fascia to expose the muscular, capsular, and bony structures of the anterior hip and pelvis. Using digital calipers, measurements were taken of the footprint of the rectus femoris on the AIIS, superior-lateral acetabulum and hip capsule, and adjacent anatomic structures. RESULTS: The average dimensions of the footprint of the direct head of the rectus femoris were 13.4 mm (±1.7) × 26.0 mm (±4.1), whereas the dimensions of the reflected head footprint were 47.7 mm (±4.4) × 16.8 mm (±2.2). Important anatomic structures, including the femoral nerve, psoas tendon, and lateral circumflex femoral artery, were noted in proximity to the AIIS. The neurovascular structure closest to the AIIS was the femoral nerve (20.8 ± 3.4 mm). CONCLUSIONS: The rectus femoris direct and reflected heads originate over a broad area of the anterolateral pelvis and are in close proximity to critical neurovascular structures, and care must be taken to avoid them during hip arthroscopy. CLINICAL RELEVANCE: A thorough knowledge of the anatomy of the proximal rectus femoris is valuable for any surgical exposure of the anterior hip joint, particularly arthroscopic subspine decompression and open femoroacetabular impingement (FAI) surgery.

Complications and reoperations during and after hip arthroscopy: a systematic review of 92 studies and more than 6,000 patients.

PURPOSE: To determine the prevalence of complications and reoperations during and after hip arthroscopy. METHODS: A systematic review of multiple medical databases was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and checklist. All clinical outcome studies that reported the presence or absence of complications and/or reoperations were eligible for inclusion. Length of follow-up was not an exclusion criterion. Complication and reoperation rates were extracted from each study. Duplicate patient populations within separate distinct publications were analyzed and reported only once. RESULTS: Ninety-two studies (6,134 participants) were included. Most were Level IV evidence studies (88%) with short-term follow-up (mean 2.0 years). Labral tears and femoroacetabular impingement (FAI) were the 2 most common diagnoses treated, and labral treatment and acetabuloplasty/femoral osteochondroplasty were the 2 most common surgical techniques reported. Overall, major and minor complication rates were 0.58% and 7.5%, respectively. Iatrogenic chondrolabral injury and temporary neuropraxia were the 2 most common minor complications. The overall reoperation rate was 6.3%, occurring at a mean of 16 months. Total hip arthroplasty (THA) was the most common reoperation. The conversion rate to THA was 2.9%. CONCLUSIONS: The rate of major complications was 0.58% after hip arthroscopy. The reoperation rate was 6.3%, and the most common reason for reoperation was conversion to THA. Minor complications and the reoperation rate are directly related to the learning curve of hip arthroscopy. As surgical indications evolve, patient selection should limit the number of cases that would have been converted to THA. Similarly, the number of minor complications is directly related to technical aspects of the procedure and therefore will decrease with surgeon experience and improvement in instrumentation. LEVEL OF EVIDENCE: Level IV, a systematic review of Level I to IV studies.

Salvage hip arthroplasty after failed fixation of proximal femur fractures.

We reviewed 46 patients who underwent salvage hip arthroplasty (SHA) for revision of failed cannulated screws (CS), sliding hip screws (SHS), or intramedullary nails (IMN). The primary objective was to determine differences in operative difficulty. SHA after failed femoral neck fixation was associated with lower intra-operative demands than after failed peri-trochanteric fractures. Similarly, analysis by the index implant found that conversion arthroplasty after failed CSs was associated with lower intra-operative morbidity than failed SHSs or IMNs; differences between SHS and IMN were not as clear. Importantly, intra-operative data in cases of failed SHSs were similar regardless of the original fracture type, showing the device played a larger role than the fracture pattern. Complications and revision surgery rates were similar regardless of fracture type or fixation device. Our results suggest that operative demands and subsequent patient morbidity are more dependent on the index device than the fracture pattern during SHA.

Addition of Pericapsular Nerve Group and Transversus Abdominis Plane Blocks Significantly Reduces Opioid Use in Patients Undergoing Concomitant Hip Arthroscopy and Periacetabular Osteotomy.

INTRODUCTION: Previous studies have evaluated the effect of the pericapsular nerve group block for hip arthroscopy and the transverse abdominis plane block for periacetabular osteotomy and have shown decreased narcotic consumption in both groups. No published study has evaluated the effectiveness of combining the blocks when performing hip arthroscopy and periacetabular osteotomy under the same general anesthesia. It was hypothesized that patients treated for hip dysplasia with hip arthroscopy and concomitant periacetabular osteotomy using a pericapsular nerve group block, transverse abdominis plane block, and general anesthesia would have decreased postoperative pain and require less narcotic consumption than those undergoing the procedure with general anesthetic alone.  Methods: A single surgeon performed a retrospective analysis of consecutive patients undergoing concomitant hip arthroscopy and periacetabular osteotomy between 11/2020 and 6/2021. Fifteen consecutive patients undergoing the procedure with a general anesthetic alone (no-block group) were compared to 15 patients undergoing the same procedure with a combined pericapsular nerve group block, transverse abdominis plane block, and general anesthetic (block group). Hip arthroscopy was performed utilizing a post-free technique, and a rectus sparing approach was used for the periacetabular osteotomy. The nerve blocks were performed by multiple anesthesiologists using previously published methods. Operating room time, length of stay, visual analog scale pain scores, and total narcotic consumption in morphine milliequivalents were analyzed. Groups were compared using the chi-squared test for non-continuous demographic variables and a two-tailed t-test for continuous variables utilizing Microsoft Excel (Microsoft, Redmond, WA, USA), p-value set at 0.05 for significance.  Results: The no-block group consisted of 14 females and one male, while the block group was all females. No significant differences were observed between age, sex, BMI, surgery time, length of stay, or procedures performed, p>0.05. The maximal visual analog scale score in the post-anesthesia care unit was 8 ± 1.3 vs. 7 ± 1.9 in the no-block vs. block groups, respectively, p=0.15. The average hospital floor visual analog scale score was 5.7 ± 1.3 vs. 4.8 ± 1.3 in the no-block vs. block groups, respectively, p=0.07. Total pain medications required were 217.6 ± 54.6 vs. 154 ± 41.9 morphine milliequivalents in the no-block vs. block groups, respectively, p=0.001. No complications were reported in either group, and no patient in the block group demonstrated motor nerve palsy or postoperative fall. CONCLUSION:  This study demonstrated that patients undergoing combined hip arthroscopy and periacetabular osteotomy for symptomatic acetabular dysplasia who had pericapsular nerve group, transverse abdominal plane block, and general anesthesia required fewer narcotics in the first 24 hours after surgery compared to those who had general anesthesia alone.

Females with hip-related pain display altered lower limb mechanics compared to their healthy counterparts in a drop jump task.

BACKGROUND: Hip-related pain describes femoroacetabular impingement syndrome, acetabular dysplasia, and other hip pain conditions without clear morphological features. Movement strategies in this population, notably sex-related patterns, are poorly understood and may provide insights into why females report more pain and worse function. This study examined the sex-related differences during a drop vertical jump task between those with hip-related pain and healthy controls. METHODS: Patients with hip-related pain and healthy controls completed five repetitions of a drop jump while their kinematics and kinetics were recorded using a motion capture system and force plates. Hip, knee, and ankle joint angles and external joint moments during landing were used in general estimating equations for comparison of group by sex by limb interactions. Time series data were further investigated using statistical parametric mapping. FINDINGS: Females with hip-related pain had 9.1° less hip flexion (P = .041) and 9.2° less knee flexion (P = .024) than healthy females, and 8.3° less knee flexion than male counterparts with hip-related pain (P = .039). Males demonstrated 1.4° less hip flexion on the affected side compared to their uninvolved side (P = .004). Statistical parametric mapping results showed significant differences in knee flexion angle for females with hip-related pain compared to healthy females (P = .042). There were no significant differences in hip, knee, or ankle moments. INTERPRETATION: Females with hip-related pain showed kinematic patterns distinct from healthy controls. Sex may be an important variable of interest in characterizing movement impairments in this population and movement impairments may be an appropriate target for intervention for these patients.

Femoroacetabular impingement: a common cause of hip pain in young adults.

OBJECTIVE: Femoroacetabular impingement (FAI) is a common cause of hip discomfort in young adults. Recently, a better understanding of the pathomechanics and morphologic abnormalities in the hip has implicated FAI as a possible factor in early osteoarthrosis. The clinical presentation, physical examination findings, and radiographic features are discussed in this article. DATA SOURCES: PubMed was searched using words and terms including femoacetabular impingement, hip osteoarthritis, hip arthroscopy, early osteoarthrosis, and hip dislocation. References of relevant studies were searched by hand. STUDY SELECTION: All studies directly involving the treatment of FAI were reviewed by 3 authors and selected for further analysis, including expert opinion and review articles. DATA SYNTHESIS: The quality of each study was assessed, and the results were summarized. CONCLUSIONS: Conservative measures, including physical therapy, restriction of activities, core strengthening, improvement of sensory-motor, and control and nonsteroidal anti-inflammatories are the mainstays of nonsurgical treatment. However, surgical management is often necessary to allow full return to activity with options including surgical dislocation of the hip, hip arthroscopy, periacetabular and rotational osteotomies, and combined hip arthroscopy with a limited open exposure. Although the literature is replete with short-term evidence to support surgical treatment, there are currently no long-term prospective data or natural history studies examining the implications of FAI and effects of early intervention.

Efficacy of treatment of trochanteric bursitis: a systematic review.

OBJECTIVE: Trochanteric bursitis (TB) is a self-limiting disorder in the majority of patients and typically responds to conservative measures. However, multiple courses of nonoperative treatment or surgical intervention may be necessary in refractory cases. The purpose of this systematic review was to evaluate the efficacy of the treatment of TB. DATA SOURCES: A literature search in the PubMed, MEDLINE, CINAHL, and ISI Web of Knowledge databases was performed for all English language studies up to April 2010. Terms combined in a Boolean search were greater trochanteric pain syndrome, trochanteric bursitis, trochanteric, bursitis, surgery, therapy, drug therapy, physical therapy, rehabilitation, injection, Z-plasty, Z-lengthening, aspiration, bursectomy, bursoscopy, osteotomy, and tendon repair. STUDY SELECTION: All studies directly involving the treatment of TB were reviewed by 2 authors and selected for further analysis. Expert opinion and review articles were excluded, as well as case series with fewer than 5 patients. Twenty-four articles were identified. According to the system described by Wright et al, 2 studies, each with multiple arms, qualified as level I evidence, 1 as level II, 1 as level III, and the rest as level IV. More than 950 cases were included. DATA EXTRACTION: The authors extracted data regarding the type of intervention, level of evidence, mean age of patients, patient gender, number of hips in the study, symptom duration before the study, mean number of injections before the study, prior hip surgeries, patient satisfaction, length of follow-up, baseline scores, and follow-up scores for the visual analog scale (VAS) and Harris Hip Scores (HHS). DATA SYNTHESIS: Symptom resolution and the ability to return to activity ranged from 49% to 100% with corticosteroid injection as the primary treatment modality with and without multimodal conservative therapy. Two comparative studies (levels II and III) found low-energy shock-wave therapy (SWT) to be superior to other nonoperative modalities. Multiple surgical options for persistent TB have been reported, including bursectomy (n = 2), longitudinal release of the iliotibial band (n = 2), proximal or distal Z-plasty (n = 4), osteotomy (n = 1), and repair of gluteus medius tears (n = 4). CONCLUSIONS: Efficacy among surgical techniques varied depending on the clinical outcome measure, but all were superior to corticosteroid therapy and physical therapy according to the VAS and HHS in both comparison studies and between studies. This systematic review found that traditional nonoperative treatment helped most patients, SWT was a good alternative, and surgery was effective in refractory cases.

The Key Parts of Hip Arthroscopy for Femoroacetabular Impingement Syndrome: Implications for the Learning Curve.

BACKGROUND: Hip arthroscopy is a rapidly growing surgical approach to treat femoroacetabular impingement (FAI) syndrome with a significant learning curve pertaining to complication risk, reoperation rate, and total hip arthroplasty conversion. Hip arthroscopy is more frequently being taught in residency and fellowship training. The key, or critical, parts of the technique have not yet been defined. PURPOSE: To identify the key components required to perform arthroscopic treatment of FAI syndrome. STUDY DESIGN: Consensus statement. METHODS: A 3-question survey comprising questions on hip arthroscopy for FAI was sent to a convenience sample of 101 high-volume arthroscopic hip surgeons in the United States. Surgeon career length (years) and maintenance volume (cases per year) were queried. Hip arthroscopy was divided into 10 steps using a Delphi technique to achieve a convergence of expert opinion. A step was considered "key" if it could (1) avoid complications, (2) reduce risk of revision arthroscopy, (3) reduce risk of total hip arthroplasty conversion, or (4) optimize patient-reported outcomes. Based on previous literature, steps with >90% of participants were defined as key. Descriptive and correlation statistics were calculated. RESULTS: A total of 64 surgeons (63% response rate) reported 5.6 ± 2.1 steps as key (median, 6; range, 1-9). Most surgeons (56.3%) had been performing hip arthroscopy for >5 years. Most surgeons (71.9%) had performed >100 hip arthroscopy procedures per year. Labral treatment (97% agreement) and cam correction (91% agreement) were the 2 key steps of hip arthroscopy for FAI. Pincer/subspine correction (86% agreement), dynamic examination before capsular closure (63% agreement), and capsular management/closure (63% agreement) were selected by a majority of respondents but did not meet the study definition of key. There was no significant correlation between surgeon experience and designation of certain steps as key. CONCLUSION: Based on a Delphi technique and expert opinion survey of high-volume surgeons, labral treatment and cam correction are the 2 key parts of hip arthroscopy for FAI syndrome.