Verma, Nikhil N.

Background: Outcomes after arthroscopic rotator cuff repair (RCR) are frequently measured through clinically significant outcomes (CSOs) such as the minimal clinically important difference, the substantial clinical benefit, and the Patient Acceptable Symptom State. Global achievement of CSOs is challenging to predict. Purpose: To determine if unsupervised machine learning can identify distinct patient subgroups based on CSO achievement after elective arthroscopic RCR. Study Design: Case-control study; Level of evidence, 3. Methods: A prospectively collected database was analyzed to identify patients who underwent elective arthroscopic RCR from 2015 to 2017. Tear dimensions were measured on magnetic resonance imaging utilizing a validated technique. CSO achievements on the American Shoulder and Elbow Surgeons, the Single Assessment Numeric Evaluation, and the Constant-Murley subjective score at 2-year follow-up were calculated. An unsupervised random forest algorithm was utilized to develop and internally validate patient subgroups with significantly different rates of CSO achievement. Patient subgroup membership, along with a total of 30 demographic and clinical variables, as well as preoperative patient-reported outcomes, were incorporated into a stepwise multivariable logistic regression to identify factors predictive of optimal CSO achievement. Results: A total of 346 patients (192 male; mean ± SD age, 57.2 ± 9.1 years; body mass index, 30.1 ± 5.4 kg/m 2 ) were eligible for inclusion and followed for a mean of 3.8 years (range, 2.0-6.2 years) Of these, a total of 333 patients were partitioned by the random forest algorithm into 2 subgroups (stability, 0.16; connectivity: 180.8; Dunn: 0.16; silhouette: 0.05), with 176 patients in the optimal achievement subgroup and 157 patients in the suboptimal achievement subgroup. The 2 subgroups differed significantly (all P ≤ .004) in the likelihood of achievement of all CSOs. Stepwise multivariable logistic regression identified an increase of 1 mm in tear size in the sagittal dimension beyond 1.9 cm to predict a 10% increase in the probability of suboptimal achievement. Additional risk factors for suboptimal CSO achievement included increasing number of tendons involved (odds ratio [OR], 14.07; 95% CI, 4.50-44.02; P < .001), subscapularis involvement (OR, 8.67; 95% CI, 2.45-30.71; P = .01), and increased preoperative CMS score (OR, 1.11; 95% CI, 1.04-1.18; P = .001). Protective factors included performance of a subpectoral biceps tenodesis compared with biceps tenotomy (OR, 0.22; 95% CI, 0.05-0.92; P = .03). Conclusion: Clinically meaningful subgroups were uncovered using an unsupervised machine learning algorithm in patients undergoing arthroscopic RCR. Tear size, number of tendons involved, and subscapularis involvement were significant and additive predictors of suboptimal CSO achievement at 2-year minimum follow-up. Treatment of concurrent biceps pathology with tenodesis conferred 78% increased likelihood of CSO achievement compared with tenotomy.

Background: Despite mounting clinical evidence for the utility of orthobiologics in nonoperative management of orthopaedic pathology, the market for orthobiologic therapies remains largely unregulated by the Food and Drug Administration, giving rise to a wide range of pricing for these therapeutics by different provider types. Purpose: To determine the availability and pricing for platelet-rich plasma (PRP), amniotic or adipose “stem cell,” and bone marrow aspirate concentrate (BMC) injections for the treatment of knee osteoarthritis among orthopaedic sports medicine and alternative providers (eg, chiropractic clinics and stand-alone “regenerative medicine” clinics) in a major metropolitan city. Study Design: Cross-sectional study. Methods: Orthopaedic sports medicine providers in the Chicagoland area were identified through the American Orthopaedic Society for Sports Medicine (AOSSM) and Arthroscopy Association of North America (AANA) surgeon databases. Alternative clinics offering orthobiologic injections were systematically compiled using Yelp! and Google search listings and reviews. Clinics were contacted using a standardized telephone script. Data were collected for each site on the types of injections offered, whether price was disclosed over the telephone, the price of injections offered, and the source of stem cell injections if they were provided. Mann-Whitney U tests were used to compare the mean price between practices. F tests for equality of variances were used to compare the variability in prices between practice types. Results: A total of 25 unique orthopaedic sports medicine practices (comprising 80 AOSSM/AANA surgeons) and 40 alternative clinics offered PRP, stem cell, and/or BMC injections, as indicated over the telephone. There was no difference in likelihood of offering PRP ( P = .698) or BMC injections ( P = .340). However, alternative clinics were significantly more likely to offer stem cell injections ( P < .001). There was no difference in the willingness to disclose the price for PRP ( P = .269), stem cell injections ( P = .302), and BMC ( P = .528) or the source of what each clinic advertised as stem cell injections ( P = .630). The mean price for a single PRP injection was significantly higher ( P = .011) and significantly more variable ( F statistic = .139; P < .001) at alternative clinics. Similarly, the mean price for a single stem cell injection was significantly higher ( P < .001) and significantly more variable ( F statistic = 0.080; P = .025) at alternative clinics. Conclusion: This study demonstrates that orthobiologic knee injections are highly prevalent for in-clinic use within the Chicago metropolitan area, with PRP being the most commonly used therapeutic. When compared with orthopaedic sports medicine providers, alternative clinics were more likely to offer stem cell injections and charge a significantly greater and more variable amount per PRP and stem cell treatment.

Background: The Latarjet and other bony augmentation procedures are commonly used to treat anterior shoulder instability in the setting of significant glenoid bone loss. Although several fixation strategies have been reported, the biomechanical strength of these techniques remains poorly understood. Purpose: To perform a systematic review of the biomechanical strength of glenoid bony augmentation procedures for anterior shoulder instability. Study Design: Systematic review; Level of evidence, 4. Methods: A systematic search of the Medline, Embase, Web of Science, and Cochrane Library databases was performed to identify biomechanical studies evaluating various fixation strategies for coracoid and other bone transfer procedures for anterior shoulder instability. Biomechanical results included load to failure with both compression and traction forces, stiffness, and cyclic displacement. The quality of included articles was assessed based on the Quality Appraisal for Cadaveric Studies (QUACS) scale. Results: A total of 21 biomechanical studies comprising 486 specimens were included. The number of screws used and the addition of washers were found to significantly increase rigidity and load to failure. The comparison of fixation techniques demonstrated mixed results in load to failure between screw and alternative constructs including suture buttons and suture anchors. However, studies that tested graft displacement consistently found more graft displacement in buttons compared with screws. The median and mean of the QUACS scale were both 12, with a range of 10-13. Conclusion: Biomechanical studies consistently demonstrated that when glenoid bone grafts were fixed with screws, the number of screws and use of washers significantly increased construct rigidity and load to failure. Different metal screw materials and sizes did not consistently demonstrate a significant difference in biomechanical strength. There are mixed results when comparing suture buttons to screw fixation. The evaluated studies revealed that all double metal screw constructs and the majority of suture button and anchor constructs were able to withstand the glenohumeral load reflective of activities of daily living using a 150-N threshold.

Purpose To assess the relation between tendon migration, as measured by radiostereometric analysis, and patient‐reported outcome measures (PROMs) after biceps tenodesis (BT); to determine the likelihood of achieving clinically significant outcomes (CSOs) after BT; and to identify factors that impact CSO achievement. Methods Patients undergoing arthroscopic suprapectoral or open subpectoral BT at a single, high‐volume academic medical center were prospectively enrolled. A tantalum bead sutured to the tenodesis construct was used as a radiopaque marker. Biceps tendon migration was measured on calibrated radiographs at 12 weeks postoperatively. PROMs (Constant‐Murley, Single Assessment Numeric Evaluation [SANE], and Patient‐Reported Outcomes Measurement Information System–Upper Extremity [PROMIS‐UE] scores) were collected preoperatively and at minimum 2‐year follow‐up. Results Of 115 patients enrolled, 94 (82%) were included (median age, 52 years; median body mass index, 31.4). At a mean follow‐up of 2.9 years, the median Constant‐Murley, SANE, and PROMIS‐UE scores were 33 (interquartile range [IQR], 26‐35), 90 (IQR, 80‐99), and 47 (IQR, 42‐58), respectively. Median tantalum bead migration was 6.5 mm (IQR, 1.8‐13.8 mm). There were significant correlations between migration and Constant‐Murley score ( r 2 = 0.222; β = –0.554 [95% confidence interval (CI), –1.027 to –0.081]; P = .022), SANE score ( r 2 = 0.238; β = –0.198 [95% CI, –0.337 to –0.058]; P = .006), and PROMIS‐UE score ( r 2 = 0.233; β = –0.406 [95% CI, –0.707 to –0.104]; P = .009). On univariable analysis, higher body mass index was associated with achievement of substantial clinical benefit (unadjusted odds ratio [OR], 1.078 [95% CI, 1.007 to 1.161]; P = .038). Greater bead migration was negatively associated with achievement of the minimal clinically important difference (unadjusted OR, 0.969 [95% CI, 0.943 to 0.993]; P = .014) and patient acceptable symptomatic state (unadjusted OR, 0.965 [95% CI, 0.937 to 0.989]; P = .008) on all 3 instruments. Conclusions A 1‐cm increase in post‐tenodesis biceps tendon migration was associated with a decrease in the Constant‐Murley, SANE, and PROMIS‐UE scores of 6, 2, and 4 points, respectively, at a mean of 2.9 years after surgery. Most patients achieved CSOs for these PROMs by latest follow‐up, and greater biceps tendon construct migration was negatively associated with the likelihood of CSO achievement. Level of Evidence Level IV, retrospective case series.

Purpose To assess the consistency and quality of risk factor reporting for rotator cuff repair (RCR) retear and identify risk factors most frequently associated with retear. Methods A systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta‐analyses (PRISMA) guidelines. Of the initial 3,158 studies, a total of 31 met the following inclusion criteria: (1) clinical studies regarding RCR failure, (2) arthroscopic procedures involving RCR, (3) reporting of clinical outcomes, (4) publication within the past 5 years, and (5) studies investigating preoperative risk factors for retear. After full‐text review, 18 risk factors were analyzed. Results The most consistently significant risk factors were acromiohumeral distance (80%), critical shoulder angle (67%), tear size (63%), anterior‐posterior dimension (60%), fatty infiltration (FI) (58%), and retraction size (56%). FI was analyzed using different methods among studies, with 63% finding significant results and 50% of all studies performing ordinal analysis. Tear size was inconsistently analyzed quantitatively or qualitatively, with 58% of studies finding significant results and 63% of all studies performing quantitative analysis. Risk factors consistently found to be nonsignificant included age, sex, diabetes mellitus, symptom duration, hand dominance, repair technique, smoking, and body mass index. Conclusions Tear size, FI, and retraction size were found to be significant risk factors in most of the included studies evaluating rotator cuff retear. Risk factors less likely reported as predictive included repair technique, age, sex, diabetes mellitus, symptom duration, hand dominance, repair technique, smoking, and body mass index. Risk factors that require further investigation include critical shoulder angle, acromiohumeral distance, and anterior‐posterior tear dimension. Level of Evidence Level III, systematic review of Level III‐IV studies.

Background: Approximately 90% of patients who undergo arthroscopic rotator cuff repair (RCR) are satisfied with their pain levels and function after surgery. However, a subset of patients experience continued symptoms that warrant revision surgery. Preoperative risk factors for RCR failure requiring revision surgery have not been clearly defined. Purpose: To (1) determine the rate of RCR failure requiring revision surgery and (2) identify risk factors for revision surgery, which will help surgeons to determine patients who are at the greatest risk for RCR failure. Study Design: Systematic review and meta-analysis; Level of evidence, 4. Methods: A systematic review and meta-analysis in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were performed. The initial search resulted in 3158 titles, and 533 full-text articles were assessed for eligibility. A total of 10 studies met the following inclusion criteria: (1) human clinical studies, (2) arthroscopic RCR, (3) original clinical research, and (4) evaluation of preoperative risk factors for revision. Results: After a full-text review, a total of 16 risk factors were recorded and analyzed across 10 studies. Corticosteroid injection was the most consistent risk factor for revision surgery, reaching statistical significance in 4 of 4 studies, followed by workers’ compensation status (2/3 studies). Patients with corticosteroid injections had a pooled increased risk of revision surgery by 47% (odds ratio, 1.44 [95% CI, 1.36-1.52]). Patients with workers’ compensation had a pooled increased risk of revision surgery by 133% (odds ratio, 2.33 [95% CI, 2.09-2.60]). Age, smoking status, diabetes, and obesity were found to be risk factors in half of the analyzed studies. Conclusion: Corticosteroid injections, regardless of the frequency of injections, and workers’ compensation status were found to be significant risk factors across the literature based on qualitative analysis and pooled analysis. Surgeons should determine ideal candidates for arthroscopic RCR by accounting for corticosteroid injection history, regardless of the frequency, and insurance status of the patient.

Background: Studies suggest that similar clinical results are achieved via arthroscopic and open biceps tenodesis (BT) techniques. Purpose: To quantify the postoperative migration of the BT construct between arthroscopic suprapectoral BT (ASPBT) and open subpectoral BT (OSPBT) techniques via interference screw (IS) or single-suture suture anchor (SSSA) fixation using radiostereometric analysis. Study Design: Cohort study; Level of evidence, 2. Methods: Distal migration of the biceps tendon after OSPBT with a polyetheretherketone IS, OSPBT with 1 SSSA, ASPBT with polyetheretherketone IS, and ASPBT with 2 SSSAs was measured prospectively. Patients with symptomatic biceps tendinopathy and preoperative patient-reported outcome measures (PROMs) including Constant-Murley subjective, Single Assessment Numeric Evaluation, or Patient-Reported Outcomes Measurement Information System–Upper Extremity scores were included. A tantalum bead was sutured on the proximal end of the long head of the biceps tendon before fixation of tendon tissue. Anteroposterior radiographs were performed immediately postoperatively, at 1 week, and at 3 months. Bead migration was measured, and preoperative PROMs were compared with those at latest follow-up. Results: Of 115 patients, 94 (82%) were available for final follow-up. IS fixation yielded the least tendon migration with no difference between the open and arthroscopic approaches (4.31 vs 5.04 mm; P = .70). Fixation with 1 suture anchor demonstrated significantly greater migration than that achieved with an IS at both 1 week (6.47 vs 0.1 mm, 6.47 vs 1.75 mm, P < .001;) and 3 months (14.76 vs 4.31 mm, 14.76 vs 5.04 mm, P < .001) postoperatively. Two-suture anchor fixation yielded significantly greater migration than IS fixation at 1 week (7.02 vs 0.1 mm, P < .001; 7.02 vs 1.75 mm, P = .003) but not 3 months postoperatively (8.06 vs 4.31 mm, P = .10; 8.06 vs 5.04 mm, P = .07). Four patients with suture anchor fixation (3 patients in the OSPBT 1 SSSA group, 9.4%, and 1 patient in the ASPBT 2 SSSAs group, 3.8%) developed a Popeye deformity, whereas no Popeye deformities occurred in the IS groups. Mean 3-month bead migration in patients with and without a Popeye deformity was 60.8 and 11.2 mm, respectively ( P < .0001). PROMs did not differ among groups at final follow-up. Conclusion: Interference screw fixation yielded the least tendon migration whether achieved arthroscopically or open. The available data indicated that fixation with 1 SSSA but not 2 SSSAs resulted in significantly greater migration than that achieved with an IS. Despite variations in tendon migration, PROMs were similar among all groups. When SSSAs are used, tendon migration may be minimized by using ≥2 anchors.

Background: All-suture anchors and knotless anchors are increasingly used in the repair of anteroinferior labral tears in patients with shoulder instability. Optimal repair constructs may limit recurrent instability. Purpose: To perform a quantitative biomechanical comparison of 3 labral fixation devices for soft tissue Bankart lesions: knotless soft-body tensionable anchor (SB knotless), knotted soft-body anchor (SB knotted), and knotless hard-body PEEK (polyether ether ketone) interference anchor (HB knotless). Study Design: Controlled laboratory study. Methods: A total of 21 glenoid specimens were randomized into 3 groups: SB knotless, SB knotted, and HB knotless. Artificial Bankart lesions were created at the anteroinferior labrum. Anchors were placed at the 3:30, 4:30, and 5:30 clockface positions, and sutures were passed through 1 cm of tissue. Anchors were tested simultaneously as one construct by pulling capsular tissue connected to the anteroinferior quadrant. Cyclic loading (5-25 N, 100 cycles) was followed by load-to-failure testing (15 mm/min). Biomechanical testing variables were collected, and failure mechanisms were recorded per individual anchor. Results: There were no differences in baseline specimen characteristics. There was no difference in elongation during cyclic loading ( P = .40). The ultimate load to failure between SB knotless (309.7 ± 125.6 N), SB knotted (226.4 ± 34.8 N), and HB knotless (256.5 ± 90.5 N) did not significantly differ ( P = .25). Failure mechanisms differed among groups ( P = .008); mechanisms included anchor pullout (SB knotless: 33.3%; SB knotted: 23.8%; HB knotless: 28.6%), suture pull-through (SB knotless: 66.7%; SB knotted: 38.1%; HB knotless: 33.3%), and anchor fixation method failure, defined as knot failure for knotted anchors or locking mechanism failure for knotless anchors (SB knotless: 0.0%; SB knotted: 38.1%; HB knotless: 38.1%).) Conclusion: The SB knotless, SB knotted, and HB knotless labral fixation anchors studied exhibited comparable elongation during cyclic loading, stiffness, and ultimate loads to failure in a cadaveric model. However, the failure mechanisms significantly differed, as SB knotless anchors failed primarily from suture pull-through, while SB knotted and HB knotless anchors were subject to knot failure and locking mechanism failure, respectively. Clinical Relevance: These data support the benefit of SB knotless anchors for anteroinferior labral repair in limiting knot failure typically seen with knotted anchors, perhaps demonstrating that all-suture anchors may have better locking mechanism quality than their PEEK counterparts.

Background: Clinically significant outcomes (CSOs) connect patient-reported outcome measures data to patient-perceived benefit. Although investigators have established threshold values for various CSOs, the timeline to achieve these outcomes after isolated biceps tenodesis (BT) has yet to be defined. Purpose: To define the time-dependent nature of minimal clinically important difference (MCID), substantial clinical benefit (SCB), and Patient Acceptable Symptom State (PASS) achievement after isolated BT. Study Design: Case series; Level of evidence, 4. Methods: The American Shoulder and Elbow Surgeons score (ASES), the Single Assessment Numeric Evaluation, and the Constant-Murley score (CMS) were administered preoperatively and at 6 and 12 months postoperatively to patients undergoing isolated BT between 2014 and 2018 at our institution. Cumulative probabilities for achieving MCID, SCB, and PASS were calculated using Kaplan-Meier survival analysis. Weibull parametric regression evaluated the hazard ratios (HRs) of achieving earlier MCID, SCB, and PASS. Results: Overall cohort (N = 190) achievement rates ranged between 77.8% and 83.2% for MCID, between 42.2% and 80.2% for SCB, and between 59.7% and 62.9% for PASS. Median achievement time was 5.3 to 6.1 months for MCID, 5.9 to 6.4 months for SCB, and 6.07 to 6.1 months for PASS. Multivariate Weibull parametric regression identified older age, male sex, higher body mass index, preoperative thyroid disease, smoking history, and higher preoperative CMS as predictors of delayed CSO achievement (HR, 1.01-6.41), whereas normal tendon on arthroscopy, defined as absence of tenosynovitis or tendon tear on arthroscopy, predicted earlier CSO achievement (HR, 0.19-0.46). Location of tenodesis and worker compensation status did not significantly predict the time to achieve CSOs on multivariate analysis. Conclusion: After isolated BT, patients can expect to attain CSO by 13 months postoperatively, with most patients achieving this between 5 and 8 months. Patients tend to take longer to achieve PASS than MCID and SCB.

AbstractPurposeRecovery following elective knee arthroscopy can be compromised by prolonged postoperative opioid utilization, yet an effective and validated risk calculator for this outcome remains elusive. The purpose of this study is to develop and validate a machine‐learning algorithm that can reliably and effectively predict prolonged opioid consumption in patients following elective knee arthroscopy.MethodsA retrospective review of an institutional outcome database was performed at a tertiary academic medical centre to identify adult patients who underwent knee arthroscopy between 2016 and 2018. Extended postoperative opioid consumption was defined as opioid consumption at least 150 days following surgery. Five machine‐learning algorithms were assessed for the ability to predict this outcome. Performances of the algorithms were assessed through discrimination, calibration, and decision curve analysis.ResultsOverall, of the 381 patients included, 60 (20.3%) demonstrated sustained postoperative opioid consumption. The factors determined for prediction of prolonged postoperative opioid prescriptions were reduced preoperative scores on the following patient‐reported outcomes: the IKDC, KOOS ADL, VR12 MCS, KOOS pain, and KOOS Sport and Activities. The ensemble model achieved the best performance based on discrimination (AUC = 0.74), calibration, and decision curve analysis. This model was integrated into a web‐based open‐access application able to provide both predictions and explanations.ConclusionFollowing appropriate external validation, the algorithm developed presently could augment timely identification of patients who are at risk of extended opioid use. Reduced scores on preoperative patient‐reported outcomes, symptom duration and perioperative oral morphine equivalents were identified as novel predictors of prolonged postoperative opioid use. The predictive model can be easily deployed in the clinical setting to identify at risk patients thus allowing providers to optimize modifiable risk factors and appropriately counsel patients preoperatively.Level of evidenceIII.