Retraction: Néel Spin-Orbit Torque Driven Antiferromagnetic Resonance in Mn_{2}Au Probed by Time-Domain THz Spectroscopy [Phys. Rev. Lett. 120, 237201 (2018)].

Retraction of DOI: 10.1103/PhysRevLett.120.237201.

Editorial Commentary: Go Ahead and Repair My Rotator Cuff. I Dare You.

A national database in the United States was used to identify increasing age, male sex, smoking, obesity, hyperlipidemia, and vitamin D deficiency as significant independent patient-specific risk factors for rotator cuff repair failure requiring revision repair. Understanding risks for repair failure can help counsel patients, inform treatment strategies, and consider treatment alternatives for patients with symptomatic rotator cuff tears.

Differential Contributions of the Quadriceps and Patellar Attachments of the Proximal Medial Patellar Restraints to Resisting Lateral Patellar Translation.

PURPOSE: To define the contributions of the of the medial patellofemoral ligament (MPFL) and medial quadriceps tendon femoral ligament (MQTFL) to lateral patellar translation as the knee moves through a 90° arc of motion. METHODS: Six pairs of bilateral cadaveric knee specimens (12 knees) were dissected and potted in perfect lateral position using fluoroscopy. An eye screw was placed in the midpoint on the lateral aspect of the patella. Each knee underwent testing in 4 conditions after sequential sectioning: intact, lateral retinacular release, randomized MQTFL or MPFL sectioning, and complete proximal medial patellar restraint (PMPR) sectioning. With a custom machined jig, all knees were tested at 0, 10, 20, 30, 45, 60, and 90° of flexion on an MTS machine with 20N of lateral patellar force applied and displacement recorded. RESULTS: PMPR extensor mechanism insertion on all specimens was identified 50% on the quadriceps tendon and 50% on the proximal aspect of the medial patella. Isolated MPFL sectioning resulted in significantly increased lateral displacement compared to the lateral release state at all flexion angles tested except 0°. There was significantly increased lateral patellar displacement with complete sectioning compared with isolated proximal sectioning at all degrees of knee flexion except 0°. However, complete sectioning following isolated MPFL sectioning did not demonstrate significance at any angle. CONCLUSIONS: Compared with the MQTFL, the MPFL is primarily responsible for resistance to lateral patellar translation throughout a 0° to 90° arc of motion. The MPFL provides a similar resistance to lateral patellar displacement as the fully intact PMPR; however, the MQTFL may contribute to resistance in full extension. CLINICAL SIGNIFICANCE: Proximal medial patellar restraint reconstruction techniques involving both the patellar and quadriceps insertion have been described; however, the unique contributions of the native anatomy to lateral patellar restraint have not been investigated.

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

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

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

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

Two-Year Patient-Reported Outcomes for Patients Undergoing Revision Hip Arthroscopy with Capsular Incompetency.

PURPOSE: To determine clinical outcomes of patients undergoing revision hip arthroscopy for failure to improve with magnetic resonance imaging (MRI) and intraoperative evidence of a capsular incompetency as compared with (1) patients undergoing revision hip arthroscopy without evidence of a capsular incompetency and (2) patients undergoing primary surgery for femoroacetabular impingement syndrome (FAIS) at a minimum follow up of 2 years. METHODS: Data from consecutive patients undergoing revision hip arthroscopy with MRI/arthrogram-confirmed capsular incompetency between January 2012 and June 2016 were analyzed. All revision patients with capsular incompetency was matched 1:1 by age and body mass index to FAIS revision patients without capsular incompetency and primary FAIS patients. Outcomes included the Hip Outcome Score (HOS)-Activities of Daily Living (ADL), HOS-Sports Subscale (SS), Modified Harris Hip Score (mHHS), pain, and satisfaction. The minimal clinically important difference was calculated for HOS-ADL, HOS-SS, and mHHS. RESULTS: In total, 49 patients (54.4%) of 90 undergoing revision hip arthroscopy had MRI evidence of a capsular incompetency. Most patients were female (79.6%), with a mean age of 30 ± 10.5 years and body mass index of 25.7 ± 5.5. The difference among pre- and postoperative HOS-ADL, HOS-SS, mHHS, and visual analog scale score for pain were all statistically significant (P < .05). Analysis of reported outcomes among matched groups demonstrated statistically significant differences, with the group undergoing primary surgery having the greatest 2-year outcomes. Only 66.7% of patients undergoing revision surgery with capsular incompetency achieved a minimal clinically important difference; however, there was no significant difference when compared with revision patients without capsular incompetency. When compared with patients undergoing primary surgery, the difference in frequency was statistically significant (66.7% vs 91.3%; P < .001). CONCLUSIONS: More than one half of patients undergoing revision hip arthroscopy had MRI and intraoperative evidence of capsular incompetency. Revision arthroscopy for capsular incompetency results in significantly improved 2-year outcomes. However, patients undergoing revision for capsular incompetency and intact capsule revision patients reported significantly lower outcomes compared with primary patients. LEVEL OF EVIDENCE: Level III, Retrospective Comparative Study.

Risk factors for opioid use after total shoulder arthroplasty.

HYPOTHESIS: The purpose was to assess opioid use before and after anatomic and reverse total shoulder arthroplasty (TSA) and determine patient factors associated with prolonged postoperative opioid use. METHODS: Patients undergoing primary TSA (anatomic or reverse) were identified within the Humana database from 2007 to 2015. Patients were categorized as opioid-naive patients who did not fill a prescription prior to surgery or those who filled opioid prescriptions within 3 months preoperatively (OU); the OU cohort was subdivided into those filling opioid prescriptions within 1 month preoperatively and those filling opioid prescriptions between 1 and 3 months preoperatively. The incidence of opioid use was evaluated preoperatively and longitudinally tracked for each cohort. Multivariate analysis was used to identify factors associated with opioid use at 12 months after surgery, with statistical significance defined as P < .05. RESULTS: Overall, 12,038 patients (5180 in OU cohort, 43%) underwent primary TSA during the study period. Opioid use declined after the first postoperative month; however, the incidence of opioid use was significantly higher in the OU cohort than in the opioid-naive cohort at 1 year (31.4% vs. 3.1%, P < .0001). Subgroup analysis revealed a similar decline in postoperative opioid use for anatomic and reverse TSA (P < .0001 for both). Multivariate analysis identified chronic preoperative opioid use (ie, filling an opioid prescription between 1 and 3 months prior to surgery) as the strongest risk factor for opioid use at 12 months after anatomic and reverse TSA (P < .0001). CONCLUSION: More than 40% of patients undergoing TSA received opioid medications within 3 months before surgery. Preoperative opioid use, age younger than 65 years, and fibromyalgia were independent risk factors for opioid use 1 year following anatomic and reverse TSA. Chronic preoperative opioid use conferred the highest risk of prolonged postoperative opioid use.

Influence of mental health on postoperative outcomes in patients following biceps tenodesis.

PURPOSE: To evaluate the relationship between preoperative mental health measured by the Short-Form 12 health survey mental component score and outcomes after isolated biceps tenodesis. METHODS: The American Shoulder and Elbow Surgeons form (ASES), Single Assessment Numeric Evaluation (SANE), Constant-Murley score (CMS), and visual analog scale (VAS) for pain were administered preoperatively and at 6 and 12 months postoperatively to consecutive patients undergoing isolated biceps tenodesis between 2014 and 2018. Minimal clinically important difference, substantial clinical benefit (SCB), patient-acceptable symptom state (PASS), and rates of achievement were calculated. Patients were stratified by mental health status based on preoperative scores on the Short-Form 12 health survey mental component score. Multivariate logistic regression was performed to evaluate preoperative mental health status on achievement of minimal clinically important difference, SCB, and PASS. RESULTS: Patients demonstrated significant improvements in all outcome measures (P < .001). Patients with depression reported inferior postoperative scores on all patient-reported outcome measures. Low preoperative mental health score significantly predicted reduced likelihood to achieve SCB (odds ratio [OR]: 0.38, 95% confidence interval [CI]: 0.17-0.81, P = .01) and PASS (OR: 0.28, 95% CI: 0.12-0.65, P = .003) on the ASES form, SANE (OR: 0.24, 95% CI: 0.10-0.61, P = .003), CMS (OR: 0.25, 95% CI: 0.08-0.77, P = .016), and VAS pain (OR: 0.01, 95% CI: 0.00-0.31, P = .008). CONCLUSION: Patients with depression reported inferior scores on all postoperative patient-reported outcome measures and demonstrated lower odds of achieving the SCB and PASS on the ASES form and PASS on the SANE, CMS, and VAS pain, compared with nondepressed patients.

Therapeutic postoperative anticoagulation is a risk factor for wound complications, infection, and revision after shoulder arthroplasty.

BACKGROUND: The purpose of the present study was to examine the relationship between postoperative therapeutic anticoagulation, wound complications, infection, and revision. METHODS: Using a national insurance database from 2007 to 2016, patients who underwent shoulder arthroplasty with an indication for postoperative therapeutic anticoagulation in the case of atrial fibrillation or acute postoperative venous thromboembolism were identified. Those with a prescription for a therapeutic anticoagulant within 2 weeks of surgery were identified and compared with controls without postoperative therapeutic anticoagulant prescriptions. Wound complications and postoperative infection at 3 and 6 months, and revision shoulder arthroplasty at 6 months and all time points were then compared in the database using a multivariable logistic regression analysis. RESULTS: A total of 17,272 patients were included, including 684 patients who received therapeutic anticoagulation and 16,588 controls. Patients receiving therapeutic anticoagulation experienced increased wound complications at 3 months (odds ratio [OR] 3.0, 95% confidence interval [CI] 2.0-4.6, P < .0001) and 6 months (OR 2.5, 95% CI 1.7-3.8, P < .0001). Patients receiving therapeutic anticoagulation also experienced increased rates of wound infection at 3 months (OR 1.5, 95% CI 1.1-2.0, P = .007) and 6 months (OR 1.8, 95% CI 1.4-2.3, P < .0001). Finally, patients receiving therapeutic anticoagulation experienced increased rates of revision surgery at 6 months (OR 1.8, 95% CI 1.3-2.5, P = .0003) and within 9 years (OR 1.5, 95% CI 1.1-2.0, P = .007). CONCLUSIONS: Wound complications and revision rates in patients undergoing shoulder arthroplasty who require postoperative therapeutic anticoagulation are significantly elevated compared with controls.

Salvage reverse total shoulder arthroplasty for failed anatomic total shoulder arthroplasty: a cohort analysis.

BACKGROUND: Reverse total shoulder arthroplasty (RTSA) as a revision procedure for failed anatomic total shoulder arthroplasty (TSA) is increasing in incidence. The purpose of this study was to analyze the results of RTSA as a revision salvage procedure for failed TSA and identify factors that influenced those outcomes. METHODS: All anatomic TSAs that were revised to RTSAs in adult patients, under the care of 2 senior surgeons at a single academic center from 2006 to 2018, were queried and reviewed. Cases in which hemiarthroplasty or RTSA was revised to RTSA were excluded. Electronic medical records and survey databases were reviewed for each subject. Demographic and surgical details were reviewed and analyzed with descriptive statistics. Preoperative and postoperative range of motion (ROM) including active forward elevation and active external rotation were evaluated. Patient-reported outcome surveys including the American Shoulder and Elbow Surgeons survey, Single Assessment Numeric Evaluation, and visual analog scale for pain were collected and analyzed. Improvement in ROM and outcome survey measures was assessed with 2-sample t tests. Complication and reoperation rates were analyzed with descriptive statistics. RESULTS: A total of 75 patients (32 men and 43 women) were available for analysis at a mean of 22.3 months. The subjects were aged 60.3 ± 11.3 years at the time of TSA and 64.6 ± 9.7 years at the time of RTSA. The average period between TSA and RTSA was 4.3 years. The 3 most common indications for revision RTSA were painful arthroplasty (n = 62, 82.7%), rotator cuff failure (n = 56, 74.7%), and unstable arthroplasty (n = 25, 33.3%), but the majority of patients had multiple indications for surgery (n = 69, 92%). Significant improvements were found in all outcome measures from the time of failed TSA diagnosis to most recent follow-up after salvage RTSA with the exception of active external rotation: American Shoulder and Elbow Surgeons score, 39 ± 15 preoperatively vs. 62 ± 25 postoperatively; Single Assessment Numeric Evaluation, 27 ± 23 vs. 60 ± 30; visual analog scale pain score, 5 ± 2 vs. 3 ± 3; and active forward elevation, 79° ± 41° vs. 128° ± 33°. Major complications occurred in 21 patients (28.4%) after salvage RTSA, and 9 (12%) underwent reoperation. CONCLUSIONS: RTSA for failed TSA can improve pain, function, and quality-of-life measures in patients with various TSA failure etiologies. However, postoperative ROM and patient-reported outcomes do not reach the values seen in the primary RTSA population.

The Association of Perioperative Glycemic Control With Adverse Outcomes Within 6 Months After Arthroscopic Rotator Cuff Repair.

PURPOSE: To determine the association between glycemic control and adverse events after arthroscopic rotator cuff repair (RCR). METHODS: Patients with a diagnosis of diabetes mellitus who underwent arthroscopic RCR and had a hemoglobin A1c (HbA1c) level determined within 3 months before or after surgery were identified in a national database and stratified by HbA1c level. The incidence of postoperative infection within 6 months was determined using Current Procedural Terminology and International Classification of Diseases, Ninth Revision codes. A receiver operating characteristic (ROC) curve analysis was performed to determine whether a threshold HbA1c level existed above which the risk of infection, revision rotator cuff surgery, and lysis of adhesions (LOA)-manipulation under anesthesia (MUA) after arthroscopic RCR was significantly increased. This threshold was then tested using a logistic regression analysis. RESULTS: The study included 3,740 patients with an infection rate ranging from a low of 0.29% to a high of 1.14% after RCR. The inflection point of the ROC curve for infection corresponded to an HbA1c level between 7.0 and 8.0 mg/dL (P = .035; area under the curve, 0.648; specificity, 61%; sensitivity, 59%). We then used 8.0 mg/dL as a threshold to test for adverse outcomes. We found a significant difference in infection rates for patients with levels below versus above the threshold (0.30% vs 0.84%; OR, 2.0; 95% confidence interval, 1.2-3.4; P = .014) but no difference in revision rates (P = .240) or LOA-MUA (P = .650) in patients with levels above versus below the threshold. CONCLUSIONS: The risk of infection after RCR in patients with diabetes mellitus increases as the perioperative HbA1c level increases and, although statistically significant, remains low. ROC curve analysis determined that a perioperative HbA1c level above 8.0 mg/dL could serve as a threshold level; however, the area under the curve and low sensitivity reflected the poor utility of this test as an independent predictor. This study did not find an association between increased perioperative HbA1c levels and rates of revision rotator cuff surgery or LOA-MUA after RCR. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Perioperative Serum 25-Hydroxyvitamin D Levels Affect Revision Surgery Rates After Arthroscopic Rotator Cuff Repair.

PURPOSE: To examine any association between perioperative serum 25-hydroxyvitamin D levels and failure of arthroscopic rotator cuff repair (RCR) requiring revision surgery. METHODS: Using a private-payer national insurance database, patients who underwent arthroscopic RCR with perioperative serum 25-hydroxyvitamin D levels recorded were included. Patients were stratified into groups of (1) serum 25-hydroxyvitamin D deficiency (<20 ng/mL), (2) insufficiency (20-30 ng/mL), or (3) sufficient (>30-<150 ng/mL). The primary outcome measure was ipsilateral revision rotator cuff surgery, including revision repair, debridement, or reverse shoulder arthroplasty. A multivariable logistic regression analysis was used to control for patient demographics and comorbidities during comparisons. RESULTS: A total of 982 patients were included in the study. The rate of revision rotator cuff surgery was significantly higher in patients in the serum 25-hydroxyvitamin D-deficient group (5.88%) compared with the serum 25-hydroxyvitamin D-sufficient control group (3.7%) (odds ratio [OR], 3.1; 95% confidence interval [CI], 1.6-5.8; P = .007). Patients with serum 25-hydroxyvitamin D deficiency (5.88%) also had a significantly higher incidence of revision surgery compared with patients with serum 25-hydroxyvitamin D insufficiency (OR, 2.4; 95% CI, 1.5-3.9; P = .011). There was no significant difference in the incidence of revision surgery in the serum 25-hydroxyvitamin D-insufficient group (4.97%) compared with the serum 25-hydroxyvitamin D-sufficient control group (3.7%) (OR, 1.4; 95% CI, 0.8-2.3; P = .250). The absolute risk reduction of revision surgery for 25-hydroxyvitamin D-deficient patients compared with controls was 2.2%, corresponding to a number needed to treat to avoid 1 revision surgery of 46 patients, relative risk reduction = 0.59. CONCLUSIONS: Although the present study found a significant statistical association between serum 25-hydroxyvitamin D deficiency and insufficiency and the rate of revision rotator cuff surgery after primary arthroscopic RCR, the absolute differences of these revision rates are minimal and are accompanied with overlapping confidence intervals limiting the clinical significance of these findings. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

The Association of Osteoporosis and Bisphosphonate Use With Revision Shoulder Surgery After Rotator Cuff Repair.

PURPOSE: To examine any association between osteoporosis and the failure of arthroscopic rotator cuff repair (ARCR) leading to revision surgery and to investigate whether the use of bisphosphonates had any influence on the observed associations. METHODS: Patients who underwent ARCR with a diagnosis of osteoporosis were identified from the PearlDiver database and stratified according to whether there was a filled prescription for a bisphosphonate in the perioperative period. Patients with osteoporosis who underwent ARCR with bisphosphonate use were compared with age- and sex-matched patients who underwent ARCR with osteoporosis without a prescription for a bisphosphonate within 1 year of surgery and patients who underwent ARCR without a diagnosis of osteoporosis and no bisphosphonate use. The primary outcome measure was ipsilateral revision rotator cuff surgery, including revision repair, debridement for a diagnosis of a rotator cuff tear, or reverse shoulder arthroplasty. A multivariable logistic regression analysis was used to control for patient demographic characteristics and comorbidities during comparisons. RESULTS: We identified 2,706 patients, including 451 in the bisphosphonate study group; 902 in the osteoporosis, no-bisphosphonate control group; and 1,353 in the non-osteoporosis control group. Patients with osteoporosis, including those to whom bisphosphonates were prescribed, had a significantly higher rate of revision rotator cuff surgery (6.58%) than patients without osteoporosis (4.51%) (odds ratio, 1.60; 95% confidence interval, 1.30-1.97; P = .008). No significant difference in the rate of revision surgery was found between patients with osteoporosis using bisphosphonates (6.65%) and age- and sex-matched patients with osteoporosis not using bisphosphonates (6.54%, P = .718). CONCLUSIONS: By using an administrative database, this study was able to show a substantial difference in the revision surgery rate after ARCR in patients with osteoporosis compared with matched controls. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Functional and Clinical Outcomes of Patients Undergoing Revision Hip Arthroscopy With Borderline Hip Dysplasia at 2-Year Follow-up.

PURPOSE: To compare outcomes of borderline hip dysplasia (BHD) patients undergoing revision hip arthroscopy with 1) patients with BHD undergoing primary hip arthroscopy for femoroacetabular impingement syndrome (FAIS) and 2) patients without BHD undergoing revision hip arthroscopy for FAIS. METHODS: A retrospective cohort study was performed to identify patients who underwent arthroscopy from January 2012 to January 2016 by a single fellowship-trained surgeon, including a 2-year follow-up. Patient demographics, comorbid medical conditions, and preoperative outcome scores were compared between patients with BHD (lateral center-edge angle 18° to 25°) who had revision hip arthroscopy to patients with BHD undergoing primary arthroscopy and patients without BHD (lateral center-edge angle >25°) undergoing revision arthroscopy. Cohorts were matched 2:1 by age and body mass index. Multivariate regressions were used to compare Hip Outcome Score, Activities of Daily Living subscale (HOS-ADL) and Sports subscale (HOS-SS) scores and modified Harris Hip Score (mHHS) between the cohorts at 2-year follow-up. Binomial regression analysis was used to determine predictors of achieving minimal clinically important difference (MCID) and patient-acceptable symptom state (PASS). RESULTS: There was no statistical difference in age and BMI between the BHD revision (29.1 ± 8.8 years; 25.5 ± 3.58 kg/m2), BHD nonrevision (28.9 ± 8.5 years; 24.6 ± 3.1 kg/m2), and non-BHD revision (29.15 ± 8.6 years; 25.01 ± 3.2 kg/m2) cohorts. There were no statistically significant differences in 2-year clinical outcomes between BHD revision patients and either BHD primary or non-BHD revision patient groups, but BHD revision patients were significantly less likely to achieve PASS for HOS-SS compared with BHD primary and non-BHD revision groups (P = .047 and P = .031, respectively). CONCLUSION: Surgeons should exercise caution when indicating patients for revision hip arthroscopy with BHD. Although the current study lacks statistical power, the available data suggest that patients undergoing revision surgery with BHD may still experience clinical improvement but be less likely to achieve PASS metrics for several patient-reported outcomes at 2-year follow up. LEVEL OF EVIDENCE: III, case-control study.

The Timing of Corticosteroid Injections Following Simple Knee Arthroscopy Is Associated With Infection Risk.

PURPOSE: To examine any association between the timing of ipsilateral postoperative corticosteroid injection following simple knee arthroscopy and infection. METHODS: Private payer (PP) and Medicare (MC) national insurance databases were queried for patients who underwent simple arthroscopic knee procedures. Patients undergoing concomitant open or more complex procedures with grafts were excluded. Patients who underwent ipsilateral corticosteroid injections within 2, 4, 6, and 8 weeks postoperatively were then identified. Postoperative infection within 90 days after the injection was assessed using International Classification of Diseases, 9th Revision, and Current Procedural Terminology coding and compared using a multivariate binomial logistic regression analysis. RESULTS: A total of 5,533 patients were identified, including 725 that received an injection within 2 weeks; 1,236 patients within 4 weeks; 1,716 patients within 6 weeks; and 1,856 patients that received an injection within 8 weeks postoperatively. In both the PP and MC datasets, the rate of infection was significantly higher in the 2-week group compared with the 6- (PP: odds ratio [OR] 3.81, P = .012; MC: OR 9.36, P = .001) and 8-week (PP: OR 8.59, P = .003; MC: OR 7.80, P = .001) groups. The rate of infection was also higher in the 4-week group compared with the 6- (PP: OR 2.54, P = .024; MC: OR 8.91, P = .001) and 8-week (PP: OR 5.64, P = .009; MC: OR 7.80, P = .001) groups. There was no difference in infection rates between the 2- and 4-week groups in either dataset (PP: P = .278; MC: P = .861). CONCLUSIONS: There is a significant association between intra-articular knee corticosteroid injections within 4 weeks of surgery and an increased incidence of postoperative infection in both MC and PP patients after knee arthroscopy compared with patients with steroid injections more than 4 weeks postoperatively and matched controls who did not receive injections. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Radiographic Prevalence of Sacroiliac Joint Abnormalities and Clinical Outcomes in Patients With Femoroacetabular Impingement Syndrome.

PURPOSE: To quantify the prevalence of sacroiliac joint (SIJ) abnormalities in patients undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAIS) by use of various imaging modalities and to compare outcomes based on SIJ abnormalities. METHODS: Plain radiographs, computed tomography (CT) scans, and magnetic resonance imaging (MRI) scans of patients who underwent primary hip arthroscopy for FAIS from January 2012 to January 2016 were identified. The exclusion criteria included patients undergoing bilateral or revision surgery, those with a history of dysplasia, and those with less than 2 years' follow-up. On radiographs, the SIJs were graded using modified New York criteria for spondyloarthropathy. CT and MRI scans were reviewed for joint surface erosion, subchondral sclerosis, joint space narrowing, pseudo-widening, bone marrow edema, and ankylosis. Patients with SIJ abnormalities were matched to patients without SIJ abnormalities in a 1:2 ratio by age and body mass index. Outcomes included the Hip Outcome Score-Activities of Daily Living (HOS-ADL), Hip Outcome Score-Sports Subscale (HOS-SS), modified Harris Hip Score (mHHS), visual analog scale (VAS) for pain, and VAS for satisfaction. RESULTS: Of 1,009 consecutive patients, 743 (73.6%) were included; 187 (25.2%) showed SIJ changes. Of these 187 patients, 164 (87.7%) had changes on plain radiographs, 88 (47.1%) had changes on CT, and 125 (66.8%) had changes on MRI. SIJ changes on any imaging modality were weakly correlated with pain to palpation of the SIJ (r = 0.11, P = .004) on physical examination. Pain to palpation of the SIJ on physical examination (odds ratio [OR], 1.12; P = .031) and a history of SIJ pain (OR, 1.93; P = .018) increased the odds of having an SIJ abnormality on any imaging modality. After matching, patients without SIJ abnormalities had a significantly greater HOS-ADL (95.4 vs 90.6, P = .001), HOS-SS (91.1 vs 77.5, P < .001), and mHHS (91.3 vs 84.5, P < .001) and a significantly lower VAS pain score (10.9 vs 25.7, P < .001) than patients with abnormalities at a mean follow-up of 34.1 ± 9.7 months (range, 24-54 months). Patients without SIJ abnormalities had greater odds of achieving the minimal clinically important difference for the HOS-ADL (OR, 2.91; P = .001) and for the HOS-SS (OR, 2.83; P < .001) but not for the mHHS (OR, 1.73; P = .081). CONCLUSIONS: A high prevalence of SIJ abnormalities (25.2%) is seen on imaging in FAIS patients. These patients may show significantly inferior clinical outcomes and persistent postoperative pain after FAIS treatment. The results of this study may allow treating orthopaedic surgeons to better inform patients with SIJ abnormalities that they may not achieve clinically significant outcome improvement after hip arthroscopy. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Obstructive sleep apnea affects complication rates following knee arthroscopy but use of continuous positive airway pressure is not protective against complications.

PURPOSE: Obstructive sleep apnea (OSA) has not been studied as a risk factor for complications following knee arthroscopy. The goals of this study were to: (1) compare complication rates after knee arthroscopy between patients with and without OSA and (2) evaluate whether continuous positive airway pressure (CPAP) mitigated complication rates. METHODS: A national private insurance database was queried for patients undergoing simple knee arthroscopy from 2007 to 2016. Patients with a diagnosis of OSA were then identified using ICD-9/10 codes. Patients with OSA were then subdivided into cohorts with and without a billing code for a CPAP device. Adverse events within 30 days postoperatively related to OSA were then assessed in all groups: (1) emergency room (ER) visit, (2) hospital admission, (3) pulmonary embolism (PE), (4) myocardial infarction, (5) respiratory arrest and (6) in-hospital mortality within 6 months postoperatively. Adverse event rates were compared between the control and study groups using a multivariable regression analysis. RESULTS: 97,036 patients underwent simple knee arthroscopy with 8656 patients having a diagnosis of OSA. Of these, 3820 (44%) had orders for CPAP machines. After controlling for confounders, patients with OSA had significantly higher risk of ER visits, PE and respiratory arrest compared to controls (p < 0.05). The majority of these significant findings persisted regardless of CPAP use. There were no significant differences in complication rates between OSA patients with and without CPAP orders. CONCLUSIONS: OSA appears to be independently associated with a higher risk for ER visits, PE and respiratory arrest following knee arthroscopy after controlling for demographic and comorbidity confounders. An order for CPAP was not associated with a significant reduction the risk for these complications. CPAP noncompliance may not be as important a factor when risk stratifying patients undergoing ambulatory knee arthroscopy compared to more significant medical comorbidities. LEVEL OF EVIDENCE: III.

Dialysis dependence and modality impact complication rates after shoulder arthroplasty.

BACKGROUND: The goals of the study were to determine (1) the incidence of dialysis patients undergoing shoulder arthroplasty (SA), (2) the association of dialysis modality with complications after SA, and (3) the association of dialysis dependence with death in patients undergoing SA and nonsurgical dialysis-dependent controls. METHODS: Using an insurance database, we identified dialysis-dependent patients undergoing SA and compared them with a matched control cohort without dialysis use. We performed an analysis comparing patients using peritoneal dialysis (PD), patients using hemodialysis (HD), matched non-dialysis-dependent controls, and matched PD and HD nonsurgical patients. Complications including in-hospital death, emergency department visits, hospital readmission, infection, and revision surgery were assessed. RESULTS: The incidence of SA in dialysis patients has significantly increased. Compared with controls, dialysis-dependent patients had increased rates of in-hospital death (odds ratio [OR], 7.60; P < .0001), emergency department visits (OR, 4.16; P < .0001), hospital admission (OR, 1.63; P < .0001), and infection within 1 year (OR, 1.90; P = .009). Compared with patients receiving HD, PD patients had lower rates of death (OR, 0.40; P = .008), hospital readmission (OR, 0.43; P = .047), and revision surgery (OR, 0.23; P = .037). as well as a lower incidence of infection (OR, 0.30; P = .018). Compared with controls, PD patients had similar rates of most complications. Compared with nonsurgical dialysis-dependent patients, the SA procedure itself was not associated with an increased mortality rate. CONCLUSIONS: Although dialysis represents a significant independent risk factor for complications after SA, this risk is highly influenced by the type of dialysis.

Certificate-of-Need State Laws and Total Hip Arthroplasty.

BACKGROUND: Many states have certificate-of-need (CON) programs requiring governmental approval to open or expand healthcare services, with the goal of limiting cost and coordinating utilization of healthcare resources. The purpose of the present study was to evaluate the associations between these state-level CON regulations and total hip arthroplasty (THA). METHODS: States were designated as CON or non-CON based on existing laws. The 100% Medicare Standard Analytic Files from 2005 to 2014 were used to compare THA procedure volumes, charges, reimbursements, and distribution of procedures based on facility volumes between the CON and non-CON states. Adverse postoperative outcomes were also analyzed. RESULTS: The per capita incidence of THA was higher in non-CON states than CON states at each time period and overall (P < .0001). However, the rate of change in THA incidence over the time period was higher in CON states (1.0 per 10,000 per year) compared to non-CON states (0.68 per 10,000 per year) although not statistically significant. Length of stay was higher and a higher percentage of patients received care in high-volume hospitals in CON states (both P < .0001). No meaningful differences in postoperative complications were found. CONCLUSION: CON laws did not appear to have limited the growth in incidence of THA nor improved quality of care or outcomes during the study time period. It does appear that CON laws are associated with increased concentration of THA procedures at higher volume facilities. Given the inherent potential confounding population and geographic factors, additional research is needed to confirm these findings.

Relationship Between Physical Therapy Characteristics, Surgical Procedure, and Clinical Outcomes in Patients After ACL Reconstruction.

CONTEXT: Postoperative rehabilitation is critical to optimize outcomes after anterior cruciate ligament reconstruction (ACLR). However, the relationship between physical therapy (PT) and clinical outcomes is unclear. OBJECTIVE: To describe PT characteristics following ACLR and to assess the relationships between PT characteristics, surgical procedure, and clinical outcomes. DESIGN: Cross-sectional. SETTING: Laboratory. Patients (or Other Participants): A total of 60 patients (31 females/29 males, age = 22.4 [9.2] y, height = 171.7 [9.9] cm, and mass = 70.2 [14.7] kg) with a history of primary unilateral ACLR (53.6% patellar tendon and 46.4% hamstring) participated. INTERVENTION(S): Patients completed a performance assessment and rated subjective knee function prior to physician clearance (mean = 6.3 [1.3] mo postoperatively) and were contacted within 6 months of clearance to complete a PT questionnaire. MAIN OUTCOME MEASURES: PT questionnaire item response, knee extension maximum voluntary isometric contraction (MVIC) torque, peak isokinetic knee extension torque, single leg hop distance, and International Knee Documentation Committee were measured. Correlations assessed relationships between PT quantity and clinical outcomes. Independent t tests compared PT quantity and clinical outcomes based on return-to-sport status, readiness to return to sport, and surgical procedure. RESULTS: Patients completed regular PT (2 d/wk, 25 wk, 58 visits) and were most likely to conclude when discharged by the therapist (68.3%). More than half (56.7%) returned to sport, yet most (73.3%) felt unready at discharge. Isokinetic torque was correlated with days of PT/week (r = .29, P = .03). Isokinetic torque and hop symmetry were reduced in patients who returned to sport (P < .05). Patients who felt ready to return completed fewer weeks of PT (P < .05). Patients with a patellar tendon graft completed more days of PT/week and total visits, but demonstrated lower MVIC torque, MVIC symmetry, and isokinetic symmetry (P < .05). CONCLUSIONS: Many patients felt unready to return to sport at PT discharge. PT frequency was associated with isokinetic torque, yet this relationship was small. Outcomes were reduced in patients who returned to sport, suggesting premature resumption of preinjury activity.