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.
Greater Postoperative Biceps Tendon Migration After Arthroscopic Suprapectoral or Open Subpectoral Biceps Tenodesis Correlates With Lower Patient‐Reported Outcome Scores
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.
A Radiostereometric Analysis of Tendon Migration After Arthroscopic and Mini-Open Biceps Tenodesis: Interference Screw Versus Single Suture Anchor Fixation
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.
Platelet‐Rich Plasma and Marrow Venting May Serve as Cost‐Effective Augmentation Techniques for Isolated Meniscal Repair: A Decision‐Analytical Markov Model–Based Analysis
Purpose To evaluate the cost‐effectiveness of 3 isolated meniscal repair (IMR) treatment strategies: platelet‐rich plasma (PRP)–augmented IMR, IMR with a marrow venting procedure (MVP), and IMR without biological augmentation. Methods A Markov model was developed to evaluate the baseline case: a young adult patient meeting the indications for IMR. Health utility values, failure rates, and transition probabilities were derived from the published literature. Costs were determined based on the typical patient undergoing IMR at an outpatient surgery center. Outcome measures included costs, quality‐adjusted life‐years (QALYs), and the incremental cost‐effectiveness ratio (ICER). Results Total costs of IMR with an MVP were $8,250; PRP‐augmented IMR, $12,031; and IMR without PRP or an MVP, $13,326. PRP‐augmented IMR resulted in an additional 2.16 QALYs, whereas IMR with an MVP produced slightly fewer QALYs, at 2.13. Non‐augmented repair produced a modeled gain of 2.02 QALYs. The ICER comparing PRP‐augmented IMR versus MVP‐augmented IMR was $161,742/QALY, which fell well above the $50,000 willingness‐to‐pay threshold. Conclusions IMR with biological augmentation (MVP or PRP) resulted in a higher number of QALYs and lower costs than non‐augmented IMR, suggesting that biological augmentation is cost‐effective. Total costs of IMR with an MVP were significantly lower than those of PRP‐augmented IMR, whereas the number of additional QALYs produced by PRP‐augmented IMR was only slightly higher than that produced by IMR with an MVP. As a result, neither treatment dominated over the other. However, because the ICER of PRP‐augmented IMR fell well above the $50,000 willingness‐to‐pay threshold, IMR with an MVP was determined to be the overall cost‐effective treatment strategy in the setting of young adult patients with isolated meniscal tears. Level of Evidence Level III, economic and decision analysis.