Preoperative Epidural Steroid Injection Does Not Increase Infection Risk Following Posterior Cervical Surgery.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The purpose of this study was to characterize the infection risk of preoperative epidural steroid injection (ESI) in patients undergoing posterior cervical surgery. SUMMARY OF BACKGROUND DATA: ESI is a helpful tool for alleviating pain and is often used as a diagnostic tool before cervical surgery. However, a recent small-scale study found that ESI before cervical fusion was associated with an increased risk of postoperative infection. MATERIALS AND METHODS: Patients from 2010 to 2020 with cervical myelopathy, spondylosis, and radiculopathy who underwent posterior cervical procedure including laminectomy, laminoforaminotomy, fusion, or laminoplasty were queried from the PearlDiver database. Patients who underwent revision or fusion above C2 or who had a diagnosis of neoplasm, trauma, or preexisting infection were excluded. Patients were divided on whether they received an ESI within 30 days before the procedure and subsequently matched by age, sex, and preoperative comorbidities. The χ 2 analysis was used to calculate the risk of postoperative infection within 90 days. Logistic regression controlling for age, sex, Elixhauser Comorbidity Index, and operated levels was conducted within the unmatched population to assess infection risk for injected patients across procedure subgroups. RESULTS: Overall, 299,417 patients were identified with 3897 having received a preoperative ESI and 295,520 who did not. Matching resulted in 975 in the injected group and 1929 in the control group. There was no significant difference in postoperative infection rate in those who received an ESI within 30 days preoperatively and those who did not (3.28% vs. 3.78%, odds ratio=0.86, 95% CI: 0.57-1.32, P =0.494). Logistic regression accounting for age, sex, Elixhauser Comorbidity Index, and levels operated demonstrated that injection did not significantly increase infection risk in any of the procedure subgroups. CONCLUSIONS: The present study found no association between preoperative ESI within 30 days before surgery and postoperative infection in patients undergoing posterior cervical surgery.

Preoperative radiographic findings associated with postoperative spinopelvic risk factors for instability following total hip arthroplasty.

Postoperative spinopelvic changes are associated with increased dislocation risk following total hip arthroplasty (THA). The aim of this study was to identify preoperative patient and radiographic factors associated with high-risk postoperative spinopelvic parameters. A retrospective review of consecutive THA patients who received preoperative and postoperative sitting and standing lateral lumbar spine-hip radiographs with minimum radiographic and clinical follow-up of 10 months was performed. Patient demographics were recorded and preoperative standing and sitting sacral slope (SS), anteinclination, pelvic femoral angle (PFA), and combined sagittal index (CSI) were measured. High-risk patients were defined by decreased spinopelvic motion (∆SS from sitting to standing of >10°), increased hip motion (∆PFA from sitting to standing of >10°), or decreased CSI of >10° at final follow-up compared with preoperative measurements. Univariate and multivariate regression analyses were used to identify preoperative demographic and radiographic factors associated with these high-risk categories. One hundred and fifty-three patients were included with an average age of 62 years, average body mass index of 27.8 kg/m2 , and average follow-up of 16.2 months. At 1-year follow-up, 43 (28.1%) patients demonstrated a decreased ∆SS > 10° and 67 (43.7%) patients demonstrated an increased ∆PFA > 10° compared with preoperative values. Sitting CSI decreased by >10° in 17 (11.1%) patients. Preoperative increased sitting PFA (adjusted odds ratio [aOR] 1.057, p < 0.001) and decreased preoperative hip motion (∆PFA) were associated with decreased sitting CSI of >10° at 10-month follow-up. Increased spinopelvic motion (∆SS) and decreased hip motion (∆PFA) preoperatively are associated with postoperative radiographic changes that be associated with increased dislocation risk.

Safety and Efficacy of Rivaroxaban in Primary Total Hip and Knee Arthroplasty.

BACKGROUND: An optimal venous thromboembolism prophylaxis agent should balance efficacy and safety. While rivaroxaban provides effective venous thromboembolism prophylaxis after total joint arthroplasty, it may be associated with higher rates of bleeding. This study aimed to compare the safety and efficacy of rivaroxaban to aspirin and enoxaparin. METHODS: A large national database was queried for patients who underwent elective primary total hip (THA) or total knee arthroplasty (TKA) from January 2015 through December 2020 who received rivaroxaban, aspirin, or enoxaparin. Multivariate analyses were performed to assess the 90-day risk of bleeding and thromboembolic complications. Among TKA patients identified, 86,721 (10.8%) received rivaroxaban, 408,038 (50.8%) received aspirin, and 108,377 (13.5%) received enoxaparin. Among THA patients, 42,469 (9.5%) received rivaroxaban, 242,876 (54.5%) received aspirin, and 59,727 (13.4%) received enoxaparin. RESULTS: After accounting for confounding factors, rivaroxaban was associated with increased risk of transfusion (TKA: adjusted odds ratio [aOR] = 2.58, P < .001; THA: aOR 1.64, P < .001), pulmonary embolism (TKA: aOR = 1.25, P = .007), and deep vein thrombosis (TKA: aOR = 1.13, P = .022) compared to aspirin. Compared to enoxaparin, rivaroxaban was associated with an increased risk of combined bleeding events (TKA: aOR = 1.07, P < .001, THA: aOR = 1.11, P < .001), but decreased risk of combined prothrombotic events (THA: aOR = 0.85, P = .036). CONCLUSION: Rivaroxaban chemoprophylaxis following TKA and THA was associated with an increased risk of bleeding and prothrombotic complications compared to aspirin and enoxaparin.

Stability analysis of tranexamic acid in the presence of various antiseptic solutions.

Tranexamic acid (TXA) effectively reduces blood loss and transfusion risk during total joint arthroplasty. Additionally, intraoperative irrigation with various antiseptic solutions is often utilized for the management and prevention of surgical site infection. However, interactions between various antiseptic solutions and TXA have not been investigated. The purpose of this in vitro study is to evaluate the stability of TXA in the presence of common orthopedic antiseptic solutions. Five antiseptic solutions-0.1% chlorhexidine (CHX) gluconate, 10% povidone-iodine (BTD), 0.5% sodium hypochlorite (Dakin's), 3% hydrogen peroxide (H2 O2 ), and 1.5% H2 O2 -and a 0.9% normal saline (NS) control were obtained. A stock 100 mg/ml TXA solution was diluted in each antiseptic solution to a concentration of 10.0 mg/ml to generate reference standard and stability samples. TXA stability in each solution was measured using high performance liquid chromatography at t = 0 and t = 120 min and reported as mean percent of theoretical concentration (MPT) with associated relative standard deviation (RSD). All experiments were performed in triplicate at room temperature. At t = 0 min, TXA remained stable when mixed with 0.9% NS, 0.1% CHX, 10% BTD, 3% H2 O2 , and 1.5% H2 O2 (MPT range: 102.0%-105.0%, RSD range: 0.80%-2.92%). Only 0.5% Dakin's led to significant degradation of TXA at t = 0 min (MPT: 14.3%, RSD:1.28%). At t = 120 min, TXA stability persisted for all compounds except Dakin's 0.5% (MPT: 18.4%, RSD: 28.7%). TXA efficacy may be significantly diminished when 0.5% Dakin's is used as an intraoperative irrigation solution. CHX, BTD, and H2 O2 do not degrade TXA.

Rotator Cuff Repair With Acromioplasty Is Associated With an Increased Rate of Revision and Subsequent Procedures.

Purpose: To evaluate the mid-term rate of revision arthroscopic rotator cuff repair as well as ipsilateral shoulder reoperations after index rotator cuff repair performed with or without acromioplasty in the United States. Methods: The Medicare Standard Analytic File, which encompasses the entire Medicare billing and payment data, was queried between 2005 and 2014. Patients undergoing arthroscopic rotator cuff repair were identified and stratified based on whether ipsilateral acromioplasty was concurrently performed using Current Procedural Terminology codes. Groups were matched by age, sex, year of index procedure, and Elixhauser index at a 2:1 ratio. Primary end point was defined as undergoing a repeat ipsilateral shoulder surgery related to the rotator cuff at 5 years of follow-up. Kaplan-Meier survival curves were constructed, and the 2 groups were compared using the log-rank test. Results: After matching, 54,209 shoulders in the rotator cuff repair with acromioplasty group and 26,448 shoulders in the rotator cuff repair without acromioplasty group were identified. Shoulders undergoing concurrent acromioplasty at index rotator cuff repair had a significantly increased rate of repeat ipsilateral cuff repair at 5 years postoperatively (8.5% vs 6.8%, P < .001). Similarly, there was an increased rate of reoperation of all types to the ipsilateral shoulder in cases where concurrent acromioplasty was performed (9.6% vs 9.1%, P < .001). Conclusions: Using a large, national database, concurrent acromioplasty at the time of rotator cuff tear was found to be associated with both an increase rate of overall subsequent procedures and revision rotator cuff repair. Level of Evidence: III, retrospective comparative study.

Midterm Survivorship of Robotic-Assisted Lateral Unicompartmental Knee Arthroplasty.

BACKGROUND: Lateral unicompartmental knee arthroplasty (UKA) is a popular alternative to total knee arthroplasty (TKA) for patients with isolated lateral compartment osteoarthritis. Few studies have investigated outcomes following robotic-assisted lateral UKA. The purpose of this study is to evaluate mid-term survivorship and patient-reported outcomes of robotic-assisted lateral UKA. METHODS: A retrospective case series was conducted on all robotic-assisted lateral UKAs performed by a single surgeon between 2013 and 2019. Patient demographics, surgical variables, and Kozinn and Scott criteria were collected. Implant survivorship was estimated using the Kaplan-Meier method with all-cause reoperation and conversion to TKA as endpoints. Participating patients were assessed for patient satisfaction and the Forgotten Joint Score-12. Correlations between patient demographics and patient outcome scores were investigated. RESULTS: In total, 120 lateral UKAs were identified, 84 of which met inclusion criteria, with a mean follow-up of 4.0 years (range 2.0-7.0). Five-year survivorship was 92.9% (95% confidence interval [CI] 84.5-96.7) with all-cause reoperation as the endpoint, and 100% (95% CI 95.0-100) with conversion to TKA as the endpoint. One patient was converted to TKA after the 5-year mark, resulting in a 6-year survival for conversion to TKA of 88.9% (95% CI 44.9-98.5). Average Forgotten Joint Score-12 score was 82.7/100, and patient satisfaction 4.7/5. Mean coronal plane correction was 2.5° ± 1.9° toward the mechanical axis. Neither final postoperative alignment nor failure to meet classic Kozinn and Scott criteria for UKA resulted in differences in patient-reported outcomes. CONCLUSION: The current study demonstrates high mid-term survivorship and excellent patient-reported outcomes with robotic-assisted lateral UKA. Robotic-assisted lateral UKA is a viable treatment option for isolated lateral compartment arthritis even in patients who do not meet classic indications.

Conversion rates and timing to total knee arthroplasty following anterior cruciate ligament reconstruction: a US population-based study.

PURPOSE: To define the rate of subsequent TKA following ACLR in a large US cohort and to identify factors that influence the risk of later undergoing TKA after ACLR. METHODS: The California's Office of Statewide Health Planning and Development (OSHPD) database was queried from 2000 to 2014 to identify patients who underwent primary ACLR (ACL group). An age-and gender-matched cohort that underwent appendectomy was selected as the control group. The cumulative incidence of TKA was calculated and ten-year survival was investigated using Kaplan-Meier analysis with failure defined as conversion to arthroplasty. Univariate and multivariate analyses were performed to explore the risk factors for conversion to TKA following ACLR. RESULTS: A total of 100,580 ACLR patients (mean age 34.48 years, 66.1%male) were matched to 100,545 patients from the general population. The ACL cohort had 1374 knee arthroplasty events; conversion rate was 0.71% at 2-year follow-up, 2.04% at 5-year follow-up, and 4.86% at 10-year follow-up. This conversion rate was higher than that of the control group at all time points, with an odds ratio of 3.44 (p<0.001) at 10-year follow-up. Decreasing survivorship following ACLR was observed with increasing age, female gender, and worker's compensation insurance, while increased survivorship was found in patients of Hispanic and Asian Pacific Islander racial heritage and those who underwent concomitant meniscal repair. CONCLUSIONS: In this US statewide study, the rate of TKA after ACLR is higher than reported elsewhere, with significantly increased odds when compared to a control group. Age, gender, concomitant knee procedures and other socioeconomic factors influence the rate of conversion to TKA following ACLR.

Reliability of Plain Radiographs Versus Magnetic Resonance Imaging to Measure Tibial Slope in Sports Medicine Patients: Can They Be Used Interchangeably?

BACKGROUND: The slope of the tibial plateau has been proposed as a reason for failure of anterior cruciate ligament reconstruction. PURPOSE: To evaluate the interobserver reliability of measurements of tibial slope on radiographs versus magnetic resonance imaging (MRI) scans and to assess whether the modalities can be used interchangeably for this purpose. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 3. METHODS: This retrospective study included 81 patients aged 18 to 30 years who were evaluated in a sports medicine setting for knee pain and who had lateral knee radiographs as well as knee MRI scans on file. Medial and lateral tibial plateau slope measurements were made by 3 blinded reviewers from the radiographs and MRI scans using graphic overlay software. The paired t test was used to compare measurements of the medial tibial plateau slope (MTPS) and lateral tibial plateau slope (LTPS) from radiographs and MRI scans. Intraclass correlation coefficients (ICCs) were calculated to determine intra- and interobserver reliability of measurements within each imaging modality, and Pearson correlation coefficients were calculated to determine the relationship between measurements on radiographs versus MRI scans. RESULTS: Imaging from 81 patients were included. The average MTPS was significantly larger on radiographs compared with MRI scans (8.7° ± 3.6° vs 3.7° ± 3.4°; P < .001), and the average LTPS was also significantly larger on radiographs compared with MRI scans (7.9° ± 3.4° vs 5.7° ± 3.7°; P < .001). ICC values indicated good to excellent intraobserver agreement for all imaging modalities (ICC, 0.81-0.97; P ≤ .009). The ICCs for interobserver reliability of MTPS and LTPS measurements were 0.92 and 0.85 for radiographs, 0.87 and 0.83 for MRI based off the subchondral bone, and 0.86 and 0.71 for MRI based off the cartilage, respectively (P < .001). Medium correlation was noted between radiographic and MRI measurements; Pearson correlation coefficients for radiographic versus subchondral MRI measurements were 0.30 and 0.37 for MTPS and LTPS, respectively. CONCLUSION: The average MTPS and LTPS were significantly larger on radiographs compared with MRI scans. Although tibial slope measurements using radiography and those using MRI are reliable between individuals, the measurements from radiographs and MRI scans cannot be used interchangeably, and caution should be used when interpreting and comparing studies using measurements of the tibial slope.

Injury Epidemiology and Time Lost From Participation in Women's NCAA Division I Indoor Versus Beach Volleyball Players.

BACKGROUND: Beach volleyball officially became a National Collegiate Athletic Association (NCAA) Division I sport in 2015-2016. Few studies have examined the epidemiology of injuries in indoor versus beach volleyball in NCAA Division I athletes. PURPOSE: To compare the epidemiology of injuries and time lost from participation between female NCAA Division I athletes who participate in indoor versus beach volleyball. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Injury surveillance data (2003-2020) were obtained using an institutional database for all NCAA Division I women's beach or indoor volleyball athletes. The total injury rate was expressed per 1000 hours played. The injury rate per body site was calculated by dividing the number of injuries in each body region by the total number of injuries. The frequency of injury per body site was also expressed as number of injuries per 1000 hours of practice or number of injuries per 1000 hours of game. The injury rate (total and per body site) and time lost from participation were compared between indoor and beach volleyball athletes. RESULTS: Participants were 161 female NCAA Division I volleyball athletes (53 beach volleyball and 108 indoor volleyball athletes). In total, 974 injuries were recorded: 170 in beach volleyball and 804 in indoor volleyball. The injury rates for beach versus indoor volleyball were 1.8 versus 5.3 injuries per 1000 hours played (P < .0001). Indoor volleyball athletes had significantly higher injury rates compared with beach volleyball players for concussion (7.5% vs 6.5%; P < .0001) and knee injury (16.7% vs 7.6%; P = .0004); however, the rate of abdominal muscle injury was significantly higher in beach versus indoor volleyball (11.8% vs 4.7%; P = .0008). Time lost from sport participation was significantly longer in beach versus indoor volleyball for knee (24 vs 11 days; P = .047), low back (25 vs 17 days; P = .0009), and shoulder (52 vs 28 days; P = .001) injuries. CONCLUSION: Based on this study, injury was more likely to occur in indoor compared with beach volleyball. Sport-related concussion and knee injuries were more common in indoor volleyball, but the rate of abdominal muscle injury was higher in beach volleyball. Beach volleyball players needed longer time to recover after injuries to the knee, low back, and shoulder.

Cross-cultural adaptation and validation of the Musculoskeletal Tumor Society (MSTS) scoring system and Toronto Extremity Salvage Score (TESS) for musculoskeletal sarcoma patients in Greece.

PURPOSE: To perform translation, cross-cultural adaptation, and validation of the Toronto Extremity Salvage Score (TESS) and Musculoskeletal Tumor Society (MSTS) scoring system in Greek patients with lower extremity sarcoma. METHODS: The Greek version of the MSTS for the lower extremity and TESS questionnaires was developed using previously reported methods. Included were 100 patients with musculoskeletal sarcoma who underwent limb salvage surgery. The test-retest reliability [interclass correlation coefficient (ICC) between 2 different time points], internal consistency (Cronbach's alpha), construct validity (Kaiser's criteria, Eigenvalue > 1 rule), and external validity (Short form-36, Spearman's Rho) were assessed. RESULTS: The test-retest reliability (ICC was 0.99 for MSTS-LE and 1 for TESS) and internal consistency were high (Cronbach's alpha was 0.763 for MSTS-LE and 0.924 for TESS) for both questionnaires. Based on the Scree plot, the number of factors retained was 1 for MSTS-LE and 2 for TESS. The TESS showed a strong correlation with SF-36 (Spearman's rho = 0.714, p < 0.001), but the correlation between MSTS for lower extremity and SF-36 was weak (Spearman's Rho = 0.313, p = 0.002). CONCLUSIONS: The Greek version of both the MSTS for lower extremity and TESS questionnaire showed sufficient reliability, internal consistency and good performance using the loading factor analysis when used postoperatively in Greek patients who underwent surgical resection of lower extremity sarcoma. However, only the TESS showed strong correlation with the SF-36, indicating that MSTS for lower extremity was not as powerful for the evaluation of the global health status of these patients.

The management of clenched fist injuries with local anaesthesia and field sterility.

Clenched fist injury is associated with a high risk of infectious complications and is commonly managed with formal irrigation and debridement in the operating theatre. The purpose of this study was to determine outcomes associated with irrigation and debridement of clenched fist injuries under local anaesthesia using field sterility outside the operative theatre. In this single centre study, 232 patients were identified with clenched fist injury and 210 were treated with a standard protocol beginning with administration of intravenous antibiotics and then irrigation and debridement at the bedside. Primary outcome measures were the need for repeat debridement and complications. Secondary outcome measures included factors associated with the need for repeat debridement. Fifteen of the 210 patients (7%) required repeat debridement. Patients with cultures positive for gram-negative organisms had a significantly increased risk of repeat debridement. Irrigation and debridement under local anaesthesia using field sterility results in an acceptably low risk of complications or need for repeat debridement.Level of evidence: IV.

Comparison of Proximal Junctional Failure and Functional Outcomes Across Varying Definitions of Proximal Junctional Kyphosis.

BACKGROUND: Proximal junctional kyphosis (PJK) is a well-recognized complication following surgery for adult spinal deformity (ASD); however, definitions for PJK and its clinical implications can significantly vary by study. This study compares multiple definitions of PJK and describes incidence and clinical significance by definition. METHODS: From 2014 to 2019, patients with ASD who underwent spinal fusion were identified. Nine definitions of PJK were created based on previously established definitions using the following upper instrumented vertebra +2 (UIV+2) sagittal Cobb measurements: A= ≥10 postoperative AND preoperative, B = ≥10 postoperative, C = ≥10 preoperative, D = ≥15 postoperative AND preoperative, E = ≥15 postoperative, F = ≥15 preoperative, G = ≥20 postoperative AND preoperative, H = ≥20 postoperative, I = >20 preoperative. Incidence of PJK was calculated by definition. Area under the curve (AUC) was calculated based on a receiver operating characteristic to assess ability to predict proximal junctional failure (PJF). Univariate analysis was performed to assess association with postoperative Oswestry Disability Index (ODI) scores. RESULTS: Across 82 patients, the incidence of PJK and AUC by definition was as follows: A = 47%, 0.47; B = 72%, 0.65; C = 49%, 0.45; D = 27%, 0.46; E = 57%, 0.62; F = 27%, 0.46; G = 10%, 0.55; H = 40%, 0.71; I = 10%, 0.55. No definition was associated with postoperative ODI scores (P < 0.05). CONCLUSIONS: The incidence of PJK significantly decreased with stricter definitions. Definitions utilizing only postoperative UIV+2 values had higher incidences but were more likely to capture patients who developed PJF. No definition was associated with postoperative ODI scores. UIV+2 ≥20 was best in distinguishing patients who developed PJF.

Can We Identify Why Athletes Fail to Return to Sport After Hip Arthroscopy for Femoroacetabular Impingement Syndrome? A Systematic Review and Meta-analysis.

BACKGROUND: No previous systematic review has focused on the athletes who fail to return to sport after hip arthroscopy for femoroacetabular impingement syndrome (FAIS). PURPOSE: To review the literature on the athletes who fail to return to sport after hip arthroscopy for FAIS to determine the rate of nonreturning athletes and explore the reasons for their inability to return to sport after arthroscopic FAI surgery. STUDY DESIGN: Systematic review and meta-analysis. METHODS: Three electronic databases were searched for eligible articles. Two reviewers independently screened the titles, abstracts, and full-text articles using prespecified criteria. Eligible articles were those that clearly stated the rate of athletes who did not return to sport after hip arthroscopy for FAIS. Data collected were the rate of patients who did not return to sport, the level of competition (high level, recreational, or mixed), the type of sport, comments on patients who did not return to sport, the rate of subsequent hip surgeries (total hip replacement or revision hip arthroscopy) in nonreturning athletes, and the reported reason for not returning to sport. A random-effects model was used for meta-analysis. RESULTS: Twenty studies were eligible for inclusion, and 1093 athletes were analyzed. The weighted rate of athletes who did not return to sport after hip arthroscopy for FAIS was 12.1% (95% CI, 7.7-17.4). Only 2 studies (2/20;10%) reported the age of the athletes who did not return, while sex was reported in 3 studies (3/20;15%). The estimated proportion of athletes who did not return to sport because of hip-related issues was significantly greater than the percentage of athletes who did not return for reasons unrelated to their hip (74.3% vs 22.3%; P < .0001). Persistent hip pain was the most commonly reported factor (52/110 patients; 47.2%) associated with failure to return to sport. Whether the nonreturning athletes underwent any subsequent hip procedure after hip arthroscopy for FAIS was reported in only 4 out of 20 studies (20%). There was evidence of publication bias and study heterogeneity. CONCLUSION: The estimated rate of athletes who did not return to sport after hip arthroscopy for FAIS was 12%, with the majority of athletes being unable to return because of persistent hip pain. There is a severe lack of evidence on the athlete characteristics and clinical course of the nonreturning athletes, and the rate of subsequent hip procedures is unknown. The outcomes and reasons for athletes not returning to sport should be reported in detail to improve patient care.

Cutting, Impingement, Contact, Endurance, Flexibility, and Asymmetric/Overhead Sports: Is There a Difference in Return-to-Sport Rate After Arthroscopic Femoroacetabular Impingement Surgery? A Systematic Review and Meta-analysis.

BACKGROUND: Previous studies have established a classification of sports based on hip mechanics: cutting, impingement, contact, endurance, flexibility, and asymmetric/overhead. No previous review has compared the outcomes of hip arthroscopy for femoroacetabular impingement syndrome (FAIS) using this classification. PURPOSE: To determine whether the rate of return to sport differs among cutting, impingement, contact, endurance, flexibility, and asymmetric/overhead athletes who undergo hip arthroscopy for FAIS. We also aimed to identify differences in patient characteristics, intraoperative procedures performed, and time to return to play among the 6 sport categories. STUDY DESIGN: Systematic review and meta-analysis. METHODS: Three electronic databases were searched for eligible articles. Two reviewers independently screened the titles, abstract, and full-text articles using prespecified criteria. Eligible articles were those that reported the rate of return to sport (defined by the number of hips) after hip arthroscopy for FAIS in athletes of all levels. Data collected were patient age, sex, body mass index, type of sport, rate and time to return to sport, and intraoperative procedures performed. A mixed effects model was used for meta-analysis. RESULTS: A total of 29 articles and 1426 hip arthroscopy cases were analyzed with 185 cutting, 258 impingement, 304 contact, 207 endurance, 116 flexibility, and 356 asymmetric/overhead athletes. The mean age was similar among the 6 subgroups (P = .532), but the proportion of female athletes was significantly higher in flexibility, endurance, and asymmetric/overhead sports as compared with impingement and contact athletes. Flexibility athletes had the highest rate of return to sport after hip arthroscopy for FAIS (94.8%), whereas contact athletes had the lowest rate (88%). The longest mean ± SD time (8.5 ± 1.9 months) to return to sport was reported in cutting sports, while endurance athletes returned faster than the rest (5.4 ± 2.6 months). The difference in rate and time to return to sport, as well as the intraoperative procedure performed, did not reach statistical significance among the 6 subgroups. There was evidence of publication bias and study heterogeneity, and the mean Methodological Index for Non-randomized Studies score was 13 ± 2.6. CONCLUSION: Flexibility athletes had the highest rate of return to sport after hip arthroscopy for FAIS, while endurance athletes returned the fastest. The difference in rate and time to return to sport and intraoperative procedures performed did not reach statistical significance among the 6 subgroups. These results are limited by the evidence of publication bias and should be interpreted with caution. Laboratory-based studies are necessary to validate the classification of sports based on hip mechanics.

Epidemiology of Anterior Cruciate Ligament Injury on Natural Grass Versus Artificial Turf in Soccer: 10-Year Data From the National Collegiate Athletic Association Injury Surveillance System.

BACKGROUND: Anterior cruciate ligament (ACL) injury is prevalent among National Collegiate Athletic Association (NCAA) soccer players. Controversy remains regarding the effect of the surface type on the rate of ACL injury in soccer players, considering differences in sex, type of athletic exposure, and level of competition. HYPOTHESIS: Natural grass surfaces would be associated with decreased ACL injury rate in NCAA soccer players. Sex, type of athletic exposure (match vs practice), and level of competition (Division I-III) would affect the relationship between playing surface and ACL injury rates. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Using the NCAA Injury Surveillance System (ISS) database, we calculated the incidence rate of ACL injury in men and women from 2004-2005 through 2013-2014 seasons. The incidence was normalized against athletic exposure (AE). Additional data collected were sex, athletic activity at time of injury (match vs practice), and level of competition (NCAA division) to stratify the analysis. Statistical comparisons were made by calculating incidence rate ratios (IRR). Statistical significance was set at an alpha of .05. RESULTS: There were 30,831,779 weighted AEs during the study period. The overall injury rate was 1.12 ACL injuries per 10,000 AEs (95% CI, 1.08-1.16). Women comprised 57% of the match data (10,261 games) and 55% of practice data (26,664 practices). The overall injury rate was significantly higher on natural grass (1.16/10,000 AEs; 95% CI, 1.12-1.20) compared with artificial turf (0.92/10,000 AEs [95% CI, 0.84-1.01]; IRR, 1.26 [95% CI, 1.14-1.38]) (P < .0001). This relationship was demonstrated consistently across all subanalyses, including stratification by NCAA division and sex. The injury rate on natural grass (0.52/10,000 AEs; 95% CI, 1.11-1.26) was significantly greater than the injury incidence during practice on artificial turf (0.06/10,000 AEs; 95% CI, 0.043-0.096). Players were 8.67 times more likely to sustain an ACL injury during practice on natural grass compared with practice on artificial turf (95% CI, 5.43-12.13; P < .0001). No significant difference was found in injury rates between matches played on grass versus turf (IRR, 0.93; 95% CI, 0.84-1.03; P = .15). CONCLUSION: NCAA soccer players who practice on natural grass have increased risk of ACL injury compared with the risk of those practicing on an artificial surface, regardless of sex or NCAA division of play. No difference in risk of ACL injury between playing surfaces was detected during matches. Further research is necessary to examine the effect of multiple factors when evaluating the effect of the surface type on the risk of ACL injury in soccer players.

Knee Arthroscopy After Total Knee Arthroplasty: Not a Benign Procedure.

BACKGROUND: Outcomes of knee arthroscopy (KA) after total knee arthroplasty (TKA) have been limited to small case series with short-term follow-up. The purpose of this study is to report the outcomes of patients who undergo a KA after a TKA using a large longitudinal database. METHODS: The PearlDiver Medicare database was queried for patients who underwent a KA procedure after a TKA on the ipsilateral extremity. A randomly selected control group was created by matching controls to cases in a 3:1 ratio based on age, gender, year of procedure, and Elixhauser Comorbidity Index. Revision for infection and all-cause revision were used as end points. RESULTS: A total of192 TKA patients who underwent a subsequent KA (TKA + KA group) were compared to 571 TKA patients who did not have a subsequent KA (TKA - KA group). The incidence of revision for infection was 6.3% in the TKA + KA group compared to 2.2% in the TKA - KA group (odds ratio, 2.87; P = .009). The incidence of all-cause revision was 18.8% in the TKA + KA group compared to 5.1% in the TKA - KA group (odds ratio, 4.34; P < .001). CONCLUSION: KA after TKA was associated with increased infection-related and all-cause revision. The association between KA and subsequent infection requires further investigation.

National Trends in Use of Regional Anesthesia and Postoperative Patterns of Opioid Prescription Filling in Shoulder Arthroscopy: A Procedure-Specific Analysis in Patients With or Without Recent Opioid Exposure.

BACKGROUND: There are few large database studies on national trends in regional anesthesia for various arthroscopic shoulder procedures and the effect of nerve blocks on the postoperative rate of opioid prescription filling. HYPOTHESIS: The use of regional nerve block will decrease the rate of opioid prescription filling after various shoulder arthroscopic procedures. Also, the postoperative pattern of opioid prescription filling will be affected by the preoperative opioid prescription-filling history. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Patient data from Humana, a large national private insurer, were queried via PearlDiver software, and a retrospective review was conducted from 2007 through 2015. Patients undergoing arthroscopic shoulder procedures were identified through Current Procedural Terminology codes. Nerve blocks were identified by relevant codes for single-shot and indwelling catheter blocks. The blocked and unblocked cases were age and sex matched to compare the pain medication prescription-filling pattern. Postoperative opioid trends (up to 6 months) were compared by regression analysis. RESULTS: We identified 82,561 cases, of which 54,578 (66.1%) included a peripheral nerve block. Of the patients who received a block, 508 underwent diagnostic shoulder arthroscopy; 2449 had labral repair; 4746 had subacromial decompression procedure; and 12,616 underwent rotator cuff repair. The percentage of patients undergoing a nerve block increased linearly over the 9-year study period (R 2 = 0.77; P = .002). After matching across the 2 cohorts, there was an identical trend in opioid prescription filling between blocked and unblocked cases (P = .95). When subdivided by procedure, there was no difference in the trends between blocked and unblocked cases (P = .52 for diagnostic arthroscopies; P = .24 for labral procedures; P = .71 for subacromial decompressions; P = .34 for rotator cuff repairs). However, when preoperative opioid users were isolated, postoperative opioid prescription filling was found to be less common in the first 2 weeks after surgery when a nerve block was given versus not given (P < .001). CONCLUSION: An increasing percentage of shoulder arthroscopies are being performed with regional nerve blocks. However, there was no difference in patterns of filled postoperative opioid prescriptions between blocked and unblocked cases, except for the subgroup of patients who had filled an opioid prescription within 1 to 3 months prior to shoulder arthroscopy. Future research should focus on recording the amount of prescribed opioids consumed in national databases to reinforce our strategy against the opioid epidemic.

Ex vivo regional gene therapy with human adipose-derived stem cells for bone repair.

BACKGROUND: The treatment of complex bone loss scenarios remains challenging. This study evaluates the efficacy of ex vivo regional gene therapy using transduced human adipose-derived stem cells (ASCs) overexpressing bone morphogenetic protein-2 (BMP-2) to treat critical-sized bone defects. METHODS: Critical-sized femoral defects created surgically in immunocompromised rats were treated with ASCs transduced with a lentivirus encoding BMP-2 (Group 1, n = 14), or green fluorescent protein (Group 2, n = 5), nontransduced ASCs (Group 3, n = 5), or rhBMP-2 (Group 4, n = 14). At 12 weeks, femurs were evaluated for quantity and quality of bone formation with plain radiographs, micro-computed tomography, histology/histomorphometry, and biomechanical strength testing. RESULTS: Thirteen of 14 samples in Group 1 and all 14 samples in Group 4 showed radiographic healing, while no samples in either Groups 2 or 3 healed. Groups 1 and 4 had significantly higher radiographic scores (p < 0.001), bone volume fraction (BV/TV) (p < 0.001), and bone area fraction (BA/TA) than Groups 2 and 3 (p < 0.001). Radiographic scores, BV/TV, and BA/TA were not significantly different between Groups 1 and 4. No difference with regards to mean torque, rotation at failure, torsional stiffness, and energy to failure was seen between Groups 1 and 4. CONCLUSIONS: Human ASCs modified to overexpress BMP-2 resulted in abundant bone formation, with the quality of bone comparable to that of rhBMP-2. This strategy represents a promising approach in the treatment of large bone defects in the clinical setting. CLINICAL RELEVANCE: Large bone defects may require sustained protein production to induce an appropriate osteoinductive response. Ex vivo regional gene therapy using a lentiviral vector has the potential to be part of a comprehensive tissue engineering strategy for treating osseous defects.

Complications of Methamphetamine Use in Orthopaedic Trauma.

OBJECTIVES: To determine whether methamphetamine (MA) users are at an increased risk for complications compared to matched controls in the setting of orthopaedic trauma. DESIGN: Retrospective cohort study. SETTING: Academic Level-1 Trauma Center. PATIENTS: MA users and matched controls. INTERVENTION: MA use. MAIN OUTCOME MEASUREMENTS: Infection, Deep Vein Thrombosis (DVT), and nonunion. RESULTS: Five hundred sixty-seven patients were included in our study (189 MA users, 378 matched controls). On univariate analysis, MA users had a higher incidence of DVT (3.2% vs. 0.5%), but no statistically significant difference in infection or nonunion rates. MA users also had a higher incidence of intensive care unit admission (36.0% vs. 27.8%), leaving the hospital against medical advice (9.0% vs. 2.1%), nonadherence to weightbearing precautions (18.8% vs. 7.3%), and a higher incidence of loss of follow-up (47.1% vs. 30.4%). However, MA users had a lower incidence of surgical treatment for orthopaedic injuries (51.9% vs. 65.9%). When surgical treatment was pursued, more trips to the operating room were required for orthopaedic injuries in the MA group (2.6 vs. 1.5 trips). On multivariate analysis, MA users continued to demonstrate a higher incidence of DVT and a lower incidence of operative management, but more trips to the operating room when surgical management was pursued, a higher admission rate to the intensive care unit, and a greater incidence of loss of follow-up. CONCLUSIONS: MA use is associated with increased inpatient and outpatient complications. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Proximal Row Carpectomy Versus 4-Corner Fusion: Incidence, Conversion to Fusion, and Cost.

PURPOSE: The primary objective of this study was to compare incidence, demographic trends, and rates of subsequent fusion between proximal row carpectomy (PRC) and 4-corner fusion (4CF) among patients in the United States. METHODS: A total of 3,636 patients who underwent PRC and 5,047 who underwent 4CF were identified from the years 2005 through 2014 among enrollees in the PearlDiver database. Regional distribution, demographic characteristics, annual incidence, comorbidities, and subsequent wrist fusion were compared between the 2 groups. Of the patients identified, 3,512 from each group were age- and sex-matched and subsequently compared for rates of converted fusion, 30- and 90-day readmission rates, and average direct cost. RESULTS: Patients undergoing 4CF and PRC did not have statistically significant differences in comorbidities. The incidence of the procedures among all subscribers increased for both PRC (1.8 per 10,000 to 2.6 per 10,000) and 4CF (1.2 per 10,000 to 2.0 per 10,000) from 2005 to 2014. Comparing the matched cohorts, patients who underwent 4CF had a higher rate of subsequent fusion than those who underwent PRC (2.67% vs 1.79%). Readmission rates were not significantly different at 30 or 90 days. Average direct cost was significantly greater for 4CF than for PRC. CONCLUSIONS: Both PRC and 4CF have been utilized at increasing rates in the past decade. Wrist fusion rates and average costs are higher in the 4CF group without a significant difference in readmission rates. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic III.