Persistently elevated joint contact stress after periacetabular osteotomy is associated with joint failure at minimum 10-year follow-up.

Periacetabular osteotomy (PAO) is a common treatment for prearthritic hip dysplasia. The goal of this investigation was to determine if computationally assessed hip contact mechanics are associated with joint failure at minimum 10-year follow-up. One hundred patients with hip dysplasia (125 hips) completed patient-reported outcomes an average of 13.8 years (range 10.0-18.0 years) after PAO. 63/125 hips were classified as having failed: 26 converted to total hip arthroplasty (THA) and 37 with significant disability indicated by modified Harris Hip Score (mHHS) ≤ 70. Differences in discrete element analysis-computed contact mechanics were compared between (1) preserved and failed hips, (2) preserved hips and hips that failed by THA, and (3) preserved hips and hips that failed by mHHS ≤ 70. Failed hips had significantly higher preoperative contact stress and exposure metrics (p < 0.001-0.009) than preserved hips. Failed hips also had significantly higher postoperative peak contact stress (p = 0.018), higher mean contact stress (p < 0.001), and smaller contact area (p = 0.044). When assessed based on type of failure, hips that failed by THA had significantly higher postoperative contact stress and exposure metrics than preserved hips (p < 0.001-0.020). In hips that failed by mHHS ≤ 70, mean postoperative contact stress exposure was significantly higher compared to preserved hips (p = 0.043). Despite improved radiographic measures of dysplasia after PAO, pathologic joint contact mechanics can persist and predict treatment failure at minimum 10 years after surgery. Operative and nonoperative techniques specifically intended to reduce harmful contact mechanics in dysplastic hips may have the potential to further improve clinical outcomes after PAO.

Menstrual Cycle Hormone Relaxin and ACL Injuries in Female Athletes: A Systematic Review.

Background: Female athletes are at increased risk for anterior cruciate ligament (ACL) injuries. The influence of hormonal variation on female ACL injury risk remains ill-defined. Recent data suggests that the collagen-degrading menstrual hormone relaxin may cyclically impact female ACL tissue quality. This review aims to identify any correlation between menstrual relaxin peaks and rates of female ACL injury. Methods: A systematic review was performed, utilizing the MEDLINE, EMBASE, and CINAHL databases. Included studies had to directly address relaxin/female ACL interactions. The primary outcome variable was relaxin proteolysis of the ACL, at cellular, tissue, joint, and whole-organism levels. The secondary outcome variable was any discussed method of moderating relaxin levels, and the clinical results if available. Results: AllThe numerous relaxin receptors on female ACLs upregulate local collagenolysis and suppress local collagen production. Peak serum relaxin concentrations (SRC) occur during menstrual cycle days 21-24; a time phase associated with greater risk of ACL injury. Oral contraceptives (OCPs) reduce SRC, with a potential ACLprotective effect. Conclusion: A reasonable correlative and plausible causative relationship exists between peak relaxin levels and increased risk of ACL injury in females, and further investigation is warranted. Level of Evidence: III.

Single-Dose Intravenous Tranexamic Acid Does Not Increase Venous Thromboembolic Rate or Complication Rate During Hip Arthroscopy.

PURPOSE: To determine whether tranexamic acid (TXA) is safe to administer preoperatively in patients undergoing hip arthroscopy by comparing the venous thromboembolic rate and complication rate between patients who did and did not receive TXA preoperatively. METHODS: This was a multicenter consecutive-cohort series of patients who underwent arthroscopic hip surgery between 2014 and 2021. The 2 cohorts comprised patients who did and did not receive TXA preoperatively (single dose of 1-2 g), after a practice change. Data were collected via chart review. Surgical outcomes included days until follow-up, visual analog scale pain score at first follow-up, total operating room (OR) time, number of arthroscopic fluid bags (3 L/bag), and complications and revision operations up to 1 year after surgery. The Mann-Whitney U test was performed for continuous variables, and the χ2 test, for categorical variables. RESULTS: A total of 862 patients were identified: 449 (52%) received TXA and 413 (48%) did not. Patient demographic characteristics including age, sex, height, weight, body mass index, smoking status, and procedures performed, as well as number of anchors used (3.5 anchors for no TXA vs 3.7 anchors for TXA) and traction time (38 minutes for no TXA vs 40 minutes for TXA), did not significantly differ between groups. Significantly more patients underwent prior hip arthroscopy in the TXA group (n = 45; primary, n = 404) than in the group that did not receive TXA (n = 25; primary, n = 388) (P = .03). Visual analog scale pain scores at the first follow-up visit (2.61 for no TXA vs 2.62 for TXA, P = .62) and the need for subsequent revision surgery (24 patients with no TXA vs 18 patients with TXA, P = .68) were not significantly different. TXA use was associated with less arthroscopic fluid utilization (5.9 bags of 3 L of fluid for no TXA vs 5.3 bags of 3 L of fluid for TXA, P < .01) and less total OR time (99.5 minutes for no TXA vs 90.0 minutes for TXA, P < .01). There was a higher overall complication rate in the group that did not receive TXA (n = 27) than in the group that did (n = 10) (P = .01). However, if lateral femoral cutaneous nerve neurapraxia was excluded, then no difference in complication rate was observed (P = .24). CONCLUSIONS: There was no difference in the incidence of venous thromboembolic complications between patients who did and did not receive TXA preoperatively. We observed a lower overall complication rate in patients who received TXA preoperatively; however, this normalized between the 2 groups when lateral femoral cutaneous nerve neuritis was excluded. No difference in early pain control or revision surgery rate was observed between groups. Although there was statistically less arthroscopic fluid utilization and less total OR time in the group that received TXA, further studies are needed to clarify whether this is clinically meaningful. Preoperatively administered TXA is a safe adjunct medication in patients undergoing arthroscopic hip surgery. LEVEL OF EVIDENCE: Level III, retrospective multicenter consecutive series.

Editorial Commentary: Complications After Meniscal Surgery Are Rare and Generally Associated With Medical Comorbidity.

Meniscal tears are prevalent and frequently require surgical intervention. This injury affects younger, active patients after acute trauma. Meniscal repair is often indicated. Degenerative tears are more common in elderly patients and are generally treated with partial meniscectomy. Other factors such as chronicity, stability, tear type, and associated injuries may also play a role in the treatment algorithm. In terms of complications, both procedures are generally safe, with a complication rate approximating 1%, but adverse effects such as deep venous thrombosis, pulmonary embolism, surgical-site infection, readmission, and reoperation can occur. Complications are more common in elderly patients. Moreover, recent research shows that complications are associated with medical comorbidities, with smoking, and with longer operating times.

Incorporating patient-specific hip orientation from weightbearing computed tomography affects discrete element analysis-computed regional joint contact mechanics in individuals treated with periacetabular osteotomy for hip dysplasia.

Computational models of the hip often omit patient-specific functional orientation when placing imaging-derived bony geometry into anatomic landmark-based coordinate systems for application of joint loading schemes. The purpose of this study was to determine if this omission meaningfully alters computed contact mechanics. Discrete element analysis models were created from non-weightbearing (NWB) clinical CT scans of 10 hip dysplasia patients (11 hips) and oriented in the International Society of Biomechanics (ISB) coordinate system (NWB-ISB). Three additional models were generated for each hip by adding patient-specific stance information obtained via weightbearing CT (WBCT) to each ISB-oriented model: (1) patient-specific sagittal tilt added (WBCT-sagittal), (2) coronal and axial rotation from optical motion capture added to (1; WBCT-combo), and (3) WBCT-derived axial, sagittal, and coronal rotation added to (1; WBCT-original). Identical gait cycle loading was applied to all models for a given hip, and computed contact stress and contact area were compared between model initialization techniques. Addition of sagittal tilt did not significantly change whole-joint peak (p = 0.922) or mean (p = 0.871) contact stress or contact area (p = 0.638). Inclusion of motion-captured coronal and axial rotation (WBCT-combo) decreased peak contact stress (p = 0.014) and slightly increased average contact area (p = 0.071) from WBCT-sagittal models. Including all WBCT-derived rotations (WBCT-original) further reduced computed peak contact stress (p = 0.001) and significantly increased contact area (p = 0.001). Variably significant differences (p = 0.001-1.0) in patient-specific acetabular subregion mechanics indicate the importance of functional orientation incorporation for modeling applications in which local contact mechanics are of interest.

Evaluation and Management of the Athlete's Hip.

Hip and groin pain is common in athletes, and there are many possible underlying pathologies. It is important to describe athletic hip pathology in the context of sport-specific physiologic loads and biomechanical demands. Three distinct types of athletes with this pathology are collision athletes, hypermobility athletes, and endurance athletes. Although there is considerable overlap between sports, athletes with hip pain should always be evaluated in the context of their sport. Understanding the effect of sport-specific biomechanical demands may help with both diagnosis and treatment of athletic hip pathology; however, each athlete's injury should be analyzed on an individual basis.

Postoperative Bracing after Medial Patellofemoral Ligament Reconstruction.

It is unclear if bracing is necessary after isolated medial patellofemoral ligament reconstruction (MPFLr) for recurrent patellar instability. We hypothesize that patients who did not use a brace will have similar outcomes to those who were braced postoperatively. A retrospective review of patients who underwent isolated MPFLr from January 2015 to September 2020 at a single institution was performed. Those with less than 6 weeks of follow-up were excluded. The braced group was provided a hinged-knee brace postoperatively until the return of quadriceps function, which was determined by the treating physical therapist (brace, "B"; no brace, "NB"). Time to straight leg raise (SLR) without lag, recurrent instability, and total re-operations were determined. Univariate analysis and logistic regression were used to evaluate outcomes (statistical significance, p < 0.05). Overall, 229 isolated MPFLr were included (B: 165 knees, 146 patients; NB: 64 knees, 58 patients). Baseline demographics were similar (all p > 0.05). Median time to SLR without lag was shorter in the NB group (41 days [interquartile range [IQR]: 20-47] vs. 44 days [IQR: 35.5-88.3], p = 0.01), while return to sport times were equivalent (B: 155 days [IQR: 127.3-193.8] vs. NB: 145 days [IQR: 124-162], p = 0.31). Recurrent instability rates were not significantly different (B: 12 knees [7.27%] vs. NB: 1 knee [1.56%], p = 0.09), but the re-operation rate was higher in the brace group (20 knees [12.1%] vs. 0 [0%], p = 0.001). Regression analysis identified brace use (odds ratio [OR]: 19.63, 95% confidence interval [CI]: 1.43-269.40, p = 0.026) and female patients (OR: 2.79, 95% CI: 1.01-7.34, p = 0.049) to be associated with needing reoperation. Recurrent instability rates and return to sport times were similar between patients who did or did not use a hinged knee brace after isolated MPFLr. Re-operation rates were higher in the braced group. Retrospective Comparative Study, Level III.

Providing a computationally derived, mechanically optimised target correction during preoperative planning can improve joint contact mechanics of hip dysplasia treated with periacetabular osteotomy.

AIM: Preoperative identification of acetabular corrections that optimally improve joint stability and reduce elevated contact stresses could further reduce osteoarthritis progression in patients with hip dysplasia who are treated with periacetabular osteotomy (PAO). The purpose of this study was to investigate how providing patient-specific, mechanically optimal acetabular reorientations to the surgeon during preoperative planning affected the surgically achieved correction. METHODS: Preoperative CT scans were used to create patient-specific hip models for 6 patients scheduled for PAO. A simulated acetabular fragment was extracted from the preoperative pelvis model and computationally rotated to simulate candidate acetabular reorientations. For each candidate, discrete element analysis was used to compute contact stresses during walking, which were summed over the gait cycle and scaled by patient age to obtain chronic contact stress-time exposure. The ideal patient-specific reorientation was identified using a cost function that balances minimising chronic stress exposures and achieving surgically acceptable acetabular coverage angles. The optimal reorientation angles and associated contact mechanics were provided to the surgeon preoperatively. After PAO was performed, a model of the surgically achieved correction was created from a postoperative CT scan. Radiographic coverage and contact mechanics were compared between preoperative, optimal, and surgically achieved orientations. RESULTS: While surgically achieved reorientations were not significantly different from optimal reorientations in radiographically measured lateral (p = 0.094) or anterior (p = 0.063) coverage, surgically achieved reorientations had significantly (p = 0.031) reduced total contact area compared to optimal reorientations. The difference in lateral coverage and peak chronic exposure between surgically achieved and optimal reorientations decreased with increasing surgeon experience using the models (R² = 0.758, R2 = 0.630, respectively). CONCLUSIONS: Providing hip surgeons with a patient-specific, computationally optimal reorientation during preoperative planning may improve contact mechanics after PAO, which may help reduce osteoarthritis progression in patients with hip dysplasia.

Incidence and risk factors for non-union of the superior ramus osteotomy when hip dysplasia is treated with periacetabular osteotomy.

Periacetabular osteotomy (PAO) is a well-established surgical treatment for hip dysplasia. Few studies report risk factors for the development of superior ramus osteotomy non-union. The purpose of this investigation was to document the incidence and risk factors for this complication. We identified 316 consecutive hips that underwent PAO for symptomatic acetabular dysplasia with a minimum 1-year radiographic follow-up. We developed and validated a technique to measure the superior ramus osteotomy location on anterior-posterior (AP) pelvis radiographs and computed tomography. Logistic regression with generalized estimating equations was used to evaluate the relationships between odds of non-union and potential demographic and radiographic predictor variables in univariate and multivariate analyses. Twenty-nine (9.2%) hips developed superior ramus non-union. Age {median [interquartile range (IQR)] 23 years (18-35) healed versus 35 years (26-40) non-united, P = 0.001}, pre-operative lateral center-edge angle (LCEA) [16° (11-20) healed versus 10° (6-13) non-united, P < 0.001] and the distance from the superior ramus osteotomy to the ilioishial line [15.8 mm (13.2-18.7) healed versus 18.1 mm (16.2-20.5) non-united, P < 0.001] varied significantly between groups. Using multivariate analysis, moderate-to-severe dysplasia [LCEA < 15°, odds ratio (OR) 5.95, standard error (SE) 3.32, 95% confidence interval (CI) 1.99-17.79, P = 0.001], increased age (5-year increase, OR 1.29, SE 3.32, 95% CI 1.105-1.60, P-value = 0.018) and distance from the ilioishial line (3-mm increase, OR 1.67, SE 0.22, 95% CI 1.29-2.18, P < 0.001) were at increased risk of developing non-union. Superior ramus osteotomy non-union is common after PAO. Older age, moderate-to-severe dysplasia, and more medial osteotomy location were independent risk factors for non-union. Consideration should be made in high-risk patients for a more lateral superior ramus osteotomy and adjuvant medical and surgical interventions.

The Impact of Age on Clinical Outcomes of Acetabular Microfracture During FAI Surgery.

BACKGROUND: Full-thickness acetabular cartilage lesions are common findings during primary surgical treatment of femoroacetabular impingement (FAI). PURPOSE: To evaluate clinical outcomes after acetabular microfracture performed during FAI surgery in a prospective, multicenter cohort. STUDY DESIGN: Cohort Study; Level of evidence, 3. METHODS: Patients with FAI who had failed nonoperative management were prospectively enrolled in a multicenter cohort. Preoperative and postoperative (mean follow-up, 4.3 years) patient-reported outcome measures were obtained with a follow-up rate of 81.6% (621/761 hips), including 54 patients who underwent acetabular microfracture. Patient characteristics, radiographic parameters, intraoperative disease severity, and operative procedures were analyzed. Propensity matching using linear regression was used to match 54 hips with microfracture to 162 control hips (1:3) to control for confounding variables. Subanalyses of hips ≤35 and >35 years of age with propensity matching were also performed. RESULTS: Patients who underwent acetabular microfracture were more likely to be male (81.8% vs 40.9%; P < .001), be older in age (35.0 vs 29.9 years; P = .001), have a higher body mass index (27.2 vs 25.0; P = .001), and have a greater alpha angle (69.6° vs 62.3°; P < .001) compared with the nonmicrofracture cohort (n = 533). After propensity matching to control for covariates, patients treated with microfracture displayed no differences in the modified Harris Hip Score or Hip Disability and Osteoarthritis Outcome Score (P = .22-.95) but were more likely to undergo total hip arthroplasty (THA) (13% [7/54] compared with 4% [6/162] in the control group; P = .002), and age >35 years was associated with conversion to THA after microfracture. Microfracture performed at or before 35 years of age portended good outcomes with no significant risk of conversion to THA at the most recent follow-up. CONCLUSION: Microfracture of acetabular cartilage defects appears to be safe and associated with reliably improved short- to mid-term results in younger patients; modified expectations should be realized when full-thickness chondral lesions are identified in patients >35 years of age.

Early Versus Delayed Surgery for Midshaft Clavicle Fractures: A Systematic Review.

Background: Orthopaedic surgeons debate the timing of and necessity for surgical intervention when treating displaced midshaft clavicle fractures (MCFs). This systematic review evaluates the available literature regarding functional outcomes, complication rates, nonunion, and reoperation rates between patients undergoing early versus delayed surgical management of MCFs. Methods: Search strategies were applied in PubMed (Medline), CINAHL (EBSCO), Embase (Elsevier), Sport Discus (EBSCO), and Cochrane Central Register of Controlled Trials (Wiley). Following an initial screening and full-text review, demographic and study outcome data was extracted for comparison between the early fixation and delayed fixation studies. Results: Twenty-one studies were identified for inclusion. This resulted in 1158 patients in the early group and 44 in the delayed. Demographics were similar between groups except for a higher percentage of males in the early group (81.6% vs. 61.4%) and longer time to surgery in the delayed group (4.6 days vs. 14.5 months). Disability of the arm, shoulder, and hand scores (3.6 vs. 13.0) and Constant-Murley scores (94.0 vs. 86.0) were better in the early group. Percentages of initial surgeries resulting in complication (33.8% vs. 63.6%), nonunion (1.2% vs. 11.4%), and nonroutine reoperation (15.8% vs. 34.1%) were higher in the delayed group. Conclusion: Outcomes of nonunion, reoperation, complications, DASH scores, and CM scores favor early surgery over delayed surgery for MCFs. However, given the small cohort of delayed patients who still achieved moderate outcomes, we recommend a shared decision-making style for treatment recommendations regarding individual patients with MCFs. Level of Evidence: II.

Return to Sport After Knee Injuries in Collegiate Wrestling.

Background: Wrestling is known to be a sport of relatively high injury incidence, and knee injuries account for a large percentage of those injuries. Treatment of these injuries varies considerably depending on injury and wrestler characteristics, leading to variability in complete recovery and return to sport (RTS). The purpose of this study was to evaluate injury trends, treatment strategies, and RTS characteristics after knee injuries in competitive collegiate wrestling. Methods: NCAA Division I collegiate wrestlers who sustained knee injuries between January 2010 and May 2020 were identified using an institutional Sports Injury Management System (SIMS). Wrestling-related knee, meniscus, and patella injuries were identified, and treatment strategies were documented to investigate potential recurrent injury trends. Descriptive statistics were used to quantify the number of days, practices, and competitions missed, return to sport times, and recurrent injuries among wrestlers. Results: Overall, 184 knee injuries were identified. After excluding non-wrestling injuries (n=11), 173 injuries remained (77 wrestlers). The mean age at time of injury was 20.8 ± 1.4 years, and the mean BMI was 25.9 ± 3.8 kg/m2. There were 135 primary injuries (74 wrestlers), which consisted of 72 (53%) ligamentous injuries, 30 (22%) meniscus injuries, 14 patellar injuries (10%), and 19 other injuries (14%). The majority of ligamentous injuries (93%) and patellar injuries (79%) were treated non-operatively, while the majority of meniscus tears (60%) underwent surgery. Twenty-three wrestlers (22%) sustained recurrent knee injuries, of which 76% were treated non-operatively after their initial injury. Recurrent injuries consisted of 12 (32%) ligamentous injuries, 14 (37%) meniscus injuries, eight (21%) patellar injuries, and four (11%) other injuries. Fifty percent of recurrent injuries were treated operatively. When comparing recurrent injuries to primary injuries, recurrent injuries had a significantly longer return to sport time (Recurrent 68.3 ± 96.0 days vs. Primary 26.0 ± 56.4 days, p=0.01). Conclusion: The majority of NCAA Division I collegiate wrestlers who sustained knee injuries were initially treated non-operatively, and approximately one in five wrestlers sustained recurrent injuries. Return to sport time was significantly increased after a recurrent injury. Level of Evidence: IV.

Radiographically successful periacetabular osteotomy does not achieve optimal contact mechanics in dysplastic hips.

BACKGROUND: Optimal correction of hip dysplasia via periacetabular osteotomy may reduce osteoarthritis development by reducing damaging contact stress. The objective of this study was to computationally determine if patient-specific acetabular corrections that optimize contact mechanics can improve upon contact mechanics resulting from clinically successful, surgically achieved corrections. METHODS: Preoperative and postoperative hip models were retrospectively created from CT scans of 20 dysplasia patients treated with periacetabular osteotomy. A digitally extracted acetabular fragment was computationally rotated in 2-degree increments around anteroposterior and oblique axes to simulate candidate acetabular reorientations. From discrete element analysis of each patient's set of candidate reorientation models, a mechanically optimal reorientation that minimized chronic contact stress exposure and a clinically optimal reorientation that balanced improving mechanics with surgically acceptable acetabular coverage angles was selected. Radiographic coverage, contact area, peak/mean contact stress, and peak/mean chronic exposure were compared between mechanically optimal, clinically optimal, and surgically achieved orientations. FINDINGS: Compared to actual surgical corrections, computationally derived mechanically/clinically optimal reorientations had a median[IQR] 13[4-16]/8[3-12] degrees and 16[6-26]/10[3-16] degrees more lateral and anterior coverage, respectively. Mechanically/clinically optimal reorientations had 212[143-353]/217[111-280] mm2 more contact area and 8.2[5.8-11.1]/6.4[4.5-9.3] MPa lower peak contact stresses than surgical corrections. Chronic metrics demonstrated similar findings (p ≤ 0.003 for all comparisons). INTERPRETATION: Computationally selected orientations achieved a greater mechanical improvement than surgically achieved corrections; however, many predicted corrections would be considered acetabular over-coverage. Identifying patient-specific corrections that balance optimizing mechanics with clinical constraints will be necessary to reduce the risk of osteoarthritis progression after periacetabular osteotomy.

Outcomes of Arthroscopic Decompression of the Anterior Inferior Iliac Spine: A Systematic Review and Meta-analysis.

BACKGROUND: Anterior inferior iliac spine (AIIS) impingement has been increasingly recognized as a source of extra-articular impingement and hip pain. However, no aggregate data analysis of patient outcomes after AIIS decompression has been performed. PURPOSE: To evaluate outcomes after arthroscopic AIIS decompression. STUDY DESIGN: Meta-analysis; Level of evidence, 4. METHODS: A systematic review was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. PubMed, EMBASE, and Cochrane Central Register of Controlled Trials were queried for all English-language studies reporting outcomes of arthroscopic AIIS decompression performed in isolation or in conjunction with hip impingement correction surgery. After screening, 10 articles were included. The indications for AIIS decompression were recorded, and weighted mean improvements in patient-reported outcome (PRO) scores, complication rates, and revision rates were calculated. RESULTS: A total of 547 patients (311 women; 57%) were identified, with a total of 620 operative hips. The mean age was 28.42 ± 5.6 years, and the mean follow-up was 25.22 ± 11.1 months. A total of 529 hips (85%) underwent AIIS decompression, 530 hips (85%) underwent femoral osteochondroplasty, and 458 hips (74%) underwent labral repair. Of the patients, 13% underwent bilateral AIIS decompression. The mean modified Harris Hip Score improved from 61.3 ± 6.9 to 88.7 ± 4.7 postoperatively (change, 27.4 ± 5.7 points; P < .001), the Hip Outcome Score-Activities of Daily Living improved from 67.2 ± 10.6 to 91.1 ± 3.2 postoperatively (change, 24.0 ± 8.0 points; P = .001), and the Hip Outcome Score-Sports Specific Subscale improved from 36.8 ± 19.2 to 82.8 ± 3.8 postoperatively (change, 46.0 ± 18.2 points; P = .002). The pooled risk of postoperative complications was 1.1% (95% CI, 0.1%-2.1%), and the pooled risk of needing revision surgery was 1.0% (95% CI, 0.1%-2.0%). No complication was directly attributed to the AIIS decompression portion of the procedure. CONCLUSION: PROs improved significantly after hip arthroscopy with AIIS decompression, with a low risk of postoperative complications and subsequent revision surgeries. Failure to identify extra-articular sources of hip pain in outcomes of femoroacetabular impingement syndrome, including from the AIIS, could lead to poorer outcomes and future revision surgery.

Joint contact stress improves in dysplastic hips after periacetabular osteotomy but remains higher than in normal hips.

AIM: The purpose of this study was to use computational modeling to determine if surgical correction of hip dysplasia restores hip contact mechanics to those of asymptomatic, radiographically normal hips. METHODS: Discrete element analysis (DEA) was used to compute joint contact stresses during the stance phase of normal walking gait for 10 individuals with radiographically normal, asymptomatic hips and 10 age- and weight-matched patients with acetabular dysplasia who underwent periacetabular osteotomy (PAO). RESULTS: Mean and peak contact stresses were higher (p < 0.001 and p = 0.036, respectively) in the dysplastic hips than in the matched normal hips. PAO normalised standard radiographic measurements and medialised the location of computed contact stress within the joint. Mean contact stress computed in dysplastic hips throughout the stance phase of gait (median 5.5 MPa, [IQR 3.9-6.1 MPa]) did not significantly decrease after PAO (3.7 MPa, [IQR 3.2-4.8]; p = 0.109) and remained significantly (p < 0.001) elevated compared to radiographically normal hips (2.4 MPa, [IQR 2.2-2.8 MPa]). Peak contact stress demonstrated a similar trend. Joint contact area during the stance phase of gait in the dysplastic hips increased significantly (p = 0.036) after PAO from 395 mm2 (IQR 378-496 mm2) to 595 mm2 (IQR 474-660 mm2), but remained significantly smaller (p = 0.001) than that for radiographically normal hips (median 1120 mm2, IQR 853-1444 mm2). CONCLUSIONS: While contact mechanics in dysplastic hips more closely resembled those of normal hips after PAO, the elevated contact stresses and smaller contact areas remaining after PAO indicate ongoing mechanical abnormalities should be expected even after radiographically successful surgical correction.

Intra-labral pigmented villonodular synovitis: a rare case in two adult patients.

This article discusses two rare cases of intra-labral pigmented villonodular synovitis (PVNS) of the hip. The hip joint represents the second most common location of pigmented villonodular synovitis, second to the knee [1]. The majority of hip PVNS cases either diffusely involve the synovium or are focal lesions within the joint. The lesions and synovium show foci of low signal intensity related to hemosiderin deposition, a finding that differentiates PVNS from other causes of synovial proliferation. Our case report presents two rare manifestations of PVNS lesions localized within the hip labrum. This presentation could easily be mistaken for a cyst by imaging modality. Despite the rarity of this condition, we highlight the importance of questioning the possibility of intra-labral PVNS, when patients have persistent hip pain not responding to therapy and atypical imaging findings. Highlighting this rare presentation is crucial for establishing the correct diagnosis, guiding treatment, and obtaining the best clinical outcome.

Pain Catastrophizing, Kinesiophobia, Stress, Depression, and Poor Resiliency Are Associated With Pain and Dysfunction in the Hip Preservation Population.

Background: Psychiatric disorders are known to have a negative impact on outcomes attained from hip-preservation surgery. Psychosocial traits such as resiliency and pain avoidance likely also affect treatment outcomes, however these characteristics are less easily identified, and data is lacking supporting their presence and impact on related outcomes within the hip preservation population. We therefore evaluated hip preservation patients for a variety of maladaptive psychosocial traits and assessed patient-reported outcomes (PROs) in order to ascertain which specific traits were most associated with hip pain and dysfunction. Methods: 62 subjects aged 15-49 years presenting for evaluation of a nonarthritic hip condition completed psychosocial questionnaires and patient reported outcome measures via electronic survey as listed in table one. Participants were tested again eight weeks later to evaluate the relationship between changes in physical function, pain, and mental health behaviors. Pearson correlation coefficients assessed association between hip PROs and psychosocial tests and analyses were corrected for multiple comparisons. Results: Pain Catastrophizing (PCS), Kinesiophobia (TSK), Stress, and PROMIS-Global Mental Health (GMH) scores correlated with poor physical function and high pain scores at zero and eight weeks. Low resiliency (BRS) and depression were also associated with elevated pain on PRO tests as well as HOOS-Physical Function. There was a moderately strong correlation between improvement in PROMIS-Physical Function (PF) from zero to eight weeks and subjects initial scores for kinesiophobia, anxiety, and stress (r= -0.45, -0.41, -0.44, all p<0.05). Conclusion: PCS, TSK, Stress, Depression, and low BRS are associated with pain and disability in hip preservation subjects. Elevated TSK, Anxiety and Stress may be predictors of failure to improve with nonoperative treatment. These psychosocial characteristics should be investigated further as predictors of clinical outcomes in the hip preservation population. Level of Evidence: II.

Sex Differences in Patient-Reported Outcomes Following Surgical Hip Preservation Interventions: A Systematic Review and Meta-Analysis.

Background: Female patients undergoing hip preservation surgery often have inferior patient-reported outcome scores (PROs), raising concerns about the clinical benefit of hip preservation surgery in women. Comparison of preoperative and postoperative PROs, and change in PROs, for female versus (vs.) male hip preservation patients was completed via systematic review. Methods: In accordance with PRISMA guidelines, the MEDLINE, Cochrane Central, and Em-base databases were searched. Level I-IV studies of patients undergoing surgical intervention for femoroacetabular impingement (FAI) and/or developmental dysplasia of the hip (DDH) with at least two years of postoperative follow-up were included. Sex-stratified PRO scores or outcome information had to be included. Results: We identified 32 hip preservation studies evaluating sex-related PRO differences, and/or providing sex-specific PRO data. The quantitative analysis of 24 studies (1843 patients) was stratified by DDH status. The modified Harris Hip Score (mHHS), Hip Outcome Score-Activities of Daily Living subscale (HOS-ADL), and Hip Outcome Score-Sport-Specific subscale (HOS-SSS) were assessed. Patients undergoing surgery for FAI only were 52.1% female (n= 806/1546). As predicted, women had lower preoperative PRO scores, however, they had significantly greater improvements in HOS-ADL (20.14±4.41 vs. 26.00±0.35, p<0.05) and HOS-SSS (33.21± 0.71 vs. 38.33± 0.46, p<0.05) compared to males. Similar results were found in the DDH cohort of 330 patients (72.1% female): females had lower preoperative PRO scores, but significantly greater improvement of mHHS (22.68±0.45 vs. 10.60±1.46, p<0.01). Conclusion: The present review suggests that men undergoing surgery for FAI and/or DDH tend to have higher preoperative and postoperative PRO scores. However, it appears that women often have greater preoperative to postoperative improvement in PRO scores. This finding is strongest in surgical treatment of DDH. Level of Evidence: III.

The Incidence and Outcomes Following Treatment of Capsulolabral Adhesions in Hip Arthroscopy: A Systematic Review.

Background: To perform a systematic review to evaluate the incidence of capsulolabral adhesions following hip arthroscopy (HA) for femoroacetabular impingement (FAI); including risk factors and post-treatment outcomes. Methods: Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we queried PubMed, EMBASE, and Cochrane Central Register of Controlled Trials for English-language studies with minimum 6-month follow-up after primary or revision HA for FAI, which reported the incidence of capsulolabral adhesions. Potential adhesion risk factors, such as anchor type used and protocol for capsule closure, were assessed. Pre-operative and post-operative modified Harris Hip Score (mHHS) values were compared in studies that reported them. Results: Thirty-seven articles were included (24 primary HA; 13 revision HA). There were 6747 patients who underwent primary HA (6874 hips; 3005 female, 44%). The incidence of capsulolabral adhesions, confirmed surgically during revision HA, was low. Patients undergoing surgical treatment reported postoperative improvement per modified Harris Hip Scores. Data for 746 patients undergoing second revision HA (761 hips; 449 female, 60%), showed an incidence of adhesions greater than that of primary HA patients. Conclusion: While the incidence of symptomatic capsulolabral adhesions after primary hip arthroscopy is low; revision hip arthroscopy is strongly associated with adhesion development. Lysis of adhesions in primary hip arthroscopy patients reliably improved patient-reported outcomes. Level of Evidence: IV.

Does preoperative gabapentin or intraoperative ketorolac influence postoperative pain following hip arthroscopy?

Optimization of perioperative analgesia has important implications for patient satisfaction and short-term outcomes. This study's purpose is to assess if preoperative gabapentin or intraoperative ketorolac influences postoperative pain or time to discharge following hip arthroscopy. In total, 409 patients who underwent hip arthroscopic femoroplasty and/or acetabuloplasty with a single surgeon for femoroacetabular impingement were retrospectively reviewed (September 2017 to February 2021). The effect of preoperative gabapentin or intraoperative ketorolac on postoperative visual analog scale (VAS) pain scores, perioperative opioids in morphine milligram equivalents (MMEs), time in post-anesthesia care unit (PACU), second-stage recovery and time to discharge was assessed using unadjusted and adjusted t-tests, and generalized linear models controlling for operative time, traction time, preoperative MME, intraoperative MME and postoperative MME were compared between the groups of gabapentin to no gabapentin and ketorolac to no ketorolac. There was no difference in first PACU VAS pain score, final PACU VAS score, VAS pain score prior to discharge, average VAS pain score or pain level on follow-up call in the unadjusted or adjusted analysis for the preoperative gabapentin or intraoperative ketorolac groups. Females had higher first PACU VAS pain score (6.05 versus 5.15 P = 0.0026), final PACU VAS pain score (4.43 versus 3.90, P = 0.0045), final VAS pain score prior to discharge (3.87 versus 3.03, P < 0.001) and average postoperative pain score (4.60 versus 4.03, P < 0.001), but no difference in VAS pain score on follow-up call following surgery. Gabapentin or ketorolac was not associated with decreased VAS pain scores or time to discharge after hip arthroscopy.