Aibinder, William R

ABSTRACT The goal of this radiomic analysis is to quantify the sensitivity of radiomic features on computed tomography (CT) image pre‐processing parameters and use machine learning (ML) techniques to identify the radiomic features that are highly predictive of shoulder arthroplasty outcomes. An ML framework auto‐segmented 3D masks of the deltoid muscle and scapula bone from pre‐operative CT images of 1949 primary anatomic total shoulder arthroplasty (aTSA)/reverse total shoulder arthroplasty (rTSA) patients. Radiomic features were extracted after various image pre‐processing protocols and assessed for reproducibility. The radiomic features deemed robust to image pre‐processing were used to train ML predictive outcomes models. Feature importance data were rank‐ordered to identify the radiomic features that were highly predictive of pain, motion, and function before and after aTSA/rTSA. A sensitivity analysis identified 37 deltoid muscle and 38 scapular bone radiomic features that were robust, reproducible, and unique across image pre‐processing parameters. The most predictive deltoid muscle radiomic measurements were normalized volume, elongation, flatness, fat percentage, sphericity, and max 2D diameter column. The most predictive scapular bone radiomic measurements were flatness, sphericity, elongation, max 2D diameter column, and max 2D diameter slice. Radiomic data of the deltoid and scapula were highly predictive of pain, motion, and function before and after aTSA and rTSA. Radiomic data were more predictive than patient comorbidities, diagnosis, and implant type/size data, but less predictive than pre‐operative active range of motion measurements and patient reported outcome measures, 3D measurements from planning software, or patient demographic data. Future work is required to clinically validate these radiomic features before they can be deployed in clinical decision support tools. Level of Evidence Level III, Retrospective Comparative Outcome Study.

Introduction: We developed a computed tomography (CT)-based tool designed for automated segmentation of deltoid muscles, enabling quantification of radiomic features and muscle fatty infiltration. Prior to use in a clinical setting, this machine learning (ML)-based segmentation algorithm requires rigorous validation. The aim of this study is to conduct shoulder expert validation of a novel deltoid ML auto-segmentation and quantification tool. Materials and Methods: A SwinUnetR-based ML model trained on labeled CT scans is validated by three expert shoulder surgeons for 32 unique patients. The validation evaluates the quality of the auto-segmented deltoid images. Specifically, each of the three surgeons reviewed the auto-segmented masks relative to CT images, rated masks for clinical acceptance, and performed a correction on the ML-generated deltoid mask if the ML mask did not completely contain the full deltoid muscle, or if the ML mask included any tissue other than the deltoid. Non-inferiority of the ML model was assessed by comparing ML-generated to surgeon-corrected deltoid masks versus the inter-surgeon variation in metrics, such as volume and fatty infiltration. Results: The results of our expert shoulder surgeon validation demonstrates that 97% of ML-generated deltoid masks were clinically acceptable. Only two of the ML-generated deltoid masks required major corrections and only one was deemed clinically unacceptable. These corrections had little impact on the deltoid measurements, as the median error in the volume and fatty infiltration measurements was <1% between the ML-generated deltoid masks and the surgeon-corrected deltoid masks. The non-inferiority analysis demonstrates no significant difference between the ML-generated to surgeon-corrected masks relative to inter-surgeon variations. Conclusions: Shoulder expert validation of this CT image analysis tool demonstrates clinically acceptable performance for deltoid auto-segmentation, with no significant differences observed between deltoid image-based measurements derived from the ML generated masks and those corrected by surgeons. These findings suggest that this CT image analysis tool has potential to reliably quantify deltoid muscle size, shape, and quality. Incorporating these CT image-based measurements into the pre-operative planning process may facilitate more personalized treatment decision making, and help orthopedic surgeons make more evidence-based clinical decisions.

Background As no consensus exists on the optimal postoperative rehabilitation protocol in terrible triad injuries, we sought to characterize the reported protocols and relate them to postoperative range of motion (ROM) measures and Mayo Elbow Performance Score (MEPS). Methods A systematic review was performed by searching PubMed/MEDLINE, Embase, Web of Science, and Cochrane databases to identify articles on the operative treatment of terrible triad injuries reporting postoperative rehabilitation protocols were included. Included studies were descriptively summarized. Methodologic quality was assessed using the Methodological Index for Non-randomized Studies criteria. Meta-analysis compared postoperative ROM measures and the MEPS between patients initiating passive ROM exercises at ≤7 days vs. >7 days. Results Our review included 36 articles with 1123 elbows (66% male, mean age: 43 years, follow-up: 27 months). Of the studies reporting physical therapy protocols, it was most commonly initiated at 7 days postoperatively (6/36, 17%), passive ROM exercises at 7 days (3/25, 12%), and active ROM at 21 days (4/26, 15%). On meta-analysis, early passive ROM initiation was not associated with improved elbow ROM or MEPS. Discussion While rehabilitation protocols commonly advised passive ROM at one week post-operatively, meta-analysis did not support functional benefits of early passive ROM. Study design Systematic Review; Level of evidence, 4.

Context: Elbow medial ulnar collateral ligament (UCL) injuries have become increasingly common in athletes. Despite this, rehabilitation protocols appear to vary drastically, which may explain the clinical equipoise regarding optimal management. Objective: This systematic review reports rehabilitation characteristics reported after UCL injuries and compares reported outcomes based on early versus delayed rehabilitation. Data Sources: Our search utilized PubMed/MEDLINE, Embase, Web of Science, and Cochrane to identify all articles on UCL rehabilitation published between January 1, 2002 and October 1, 2022. Study Selection: Studies in English with ≥5 patients that reported rehabilitation protocols for UCL injuries were evaluated. Study Design: Systematic review. Level of Evidence: Level 4. Data Extraction: Data included sample characteristics, time to achieve physical therapy milestones, outcome scores, and return-to-play (RTP) rate and timing. Results: Our review included 105 articles with a total of 15,928 elbows (98% male; weighted mean age, 23 years; follow-up, 47 months), with 15,077 treated operatively and 851 treated nonoperatively. The weighted mean time patients spent adhering to nonweightbearing status was 42 days. The mean time until patients were given clearance for active range of motion (ROM) 15 days, full ROM 40 days, and elbow strengthening exercises 32 days. The mean time until all restrictions were lifted was 309 days. The mean time to begin a throwing program was 120 days. Across all rehabilitation characteristics, protocols for patients undergoing nonoperative management started patients on rehabilitation earlier. After UCL reconstruction, earlier active ROM (≤14 days), elbow strengthening (≤30 days), no restrictions (≤180 days), and throwing (≤120 days) postoperatively led to earlier RTP without a negative effect on functional outcome scores. Conclusion: Current literature provides a spectrum of protocols for elbow UCL rehabilitation, regardless of management. Nonoperative patients began ROM activities, strengthening, and throwing programs sooner than operative patients, and earlier milestones led to earlier RTP.

Background: Despite the importance of the deltoid to shoulder biomechanics, very few studies have quantified the three-dimensional shape, size, or quality of the deltoid muscle, and no studies have correlated these measurements to clinical outcomes after anatomic (aTSA) and/or reverse (rTSA) total shoulder arthroplasty in any statistically/scientifically relevant manner. Methods: Preoperative computer tomography (CT) images from 1057 patients (585 female, 469 male; 799 primary rTSA and 258 primary aTSA) of a single platform shoulder arthroplasty prosthesis (Equinoxe; Exactech, Inc., Gainesville, FL) were analyzed in this study. A machine learning (ML) framework was used to segment the deltoid muscle for 1057 patients and quantify 15 different muscle characteristics, including volumetric (size, shape, etc.) and intensity-based Hounsfield (HU) measurements. These deltoid measurements were correlated to postoperative clinical outcomes and utilized as inputs to train/test ML algorithms used to predict postoperative outcomes at multiple postoperative timepoints (1 year, 2–3 years, and 3–5 years) for aTSA and rTSA. Results: Numerous deltoid muscle measurements were demonstrated to significantly vary with age, gender, prosthesis type, and CT image kernel; notably, normalized deltoid volume and deltoid fatty infiltration were demonstrated to be relevant to preoperative and postoperative clinical outcomes after aTSA and rTSA. Incorporating deltoid image data into the ML models improved clinical outcome prediction accuracy relative to ML algorithms without image data, particularly for the prediction of abduction and forward elevation after aTSA and rTSA. Analyzing ML feature importance facilitated rank-ordering of the deltoid image measurements relevant to aTSA and rTSA clinical outcomes. Specifically, we identified that deltoid shape flatness, normalized deltoid volume, deltoid voxel skewness, and deltoid shape sphericity were the most predictive image-based features used to predict clinical outcomes after aTSA and rTSA. Many of these deltoid measurements were found to be more predictive of aTSA and rTSA postoperative outcomes than patient demographic data, comorbidity data, and diagnosis data. Conclusions: While future work is required to further refine the ML models, which include additional shoulder muscles, like the rotator cuff, our results show promise that the developed ML framework can be used to evolve traditional CT-based preoperative planning software into an evidence-based ML clinical decision support tool.

Purpose To evaluate return to play (RTP) and return to same level of play (RTSP) rates as well as preoperative and postoperative in‐game performance metrics in baseball pitchers who underwent ulnar collateral ligament reconstruction (UCLR). Secondarily, this review sought to assess outcomes based on primary versus revision UCLR as well as level of competition. Methods This review was performed using Preferred Reporting Items for Systematic Reviews and Meta‐Analyses guidelines. PubMed/MEDLINE, Embase, Web of Science, and Cochrane Database of Systematic Reviews were queried to identify articles evaluating UCLR in baseball players between January 2002 and October 2022. Data included RTP, RTSP, and performance metrics including earned run average, innings pitched, walks and hits per inning pitched, batting average against, strikeouts per 9 innings, walks per 9 innings, percentage of fastballs thrown, and average fastball velocity. The Methodological Index for Non‐randomized Studies criteria were used for quality assessment. Results Analysis included 25 articles reporting on 2,100 elbows. After primary UCLR, RTP ranged from 336 to 615 days (57% to 100% achieved) and RTSP ranged from 330 to 513 days (61% to 95%). After revision UCLR, RTP ranged from 381 to 631 days (67% to 98%) and RTSP ranged from 518 to 575 days (42% to 78%). When stratifying primary UCLR outcomes by competitive level, RTP and RTSP ranged respectively from 417 to 615 days (75% to 100%) and 513 days (73% to 87%) for Major League Baseball only, 409 to 615 days (57% to 100%) and 470 to 513 days (61% to 95%) for Major League Baseball plus Minor League Baseball, and 336 to 516 days (73% to 85%) and 330 days (55% to 74%) for college plus high school. Heterogeneity was seen in postoperative sports performance metrics. Conclusions Although more than half of baseball players appear able to RTP after primary and revision UCLR, RTSP rates after revision UCLR were as low as 42% in the literature. Preoperative and postoperative performance metrics varied. Level of Evidence Level IV, systematic review of Level II‐IV studies.

Abstract Purpose The teres minor is particularly important for activities that require external rotation in abduction in the settings of both rotator cuff tears and reverse shoulder arthroplasty. This study sought to assess the incidence of teres minor fatty infiltration in a large cohort of consecutive patients evaluated with shoulder MRI for shoulder pain and to identify all associated pathologies in an effort to determine the various potential etiologies of teres minor involvement. Methods A retrospective review of 7,376 non‐contrast shoulder MRI studies performed between 2010 and 2015 were specifically evaluated for teres minor fatty infiltration. Studies were reviewed by two fellowship trained musculoskeletal radiologists. Muscle atrophy was graded on a 3‐point scale according to Fuchs and Gerber. The remaining rotator cuff tendons and muscles, biceps tendon, labrum, and joint surfaces were assessed on MRI as well. Results In this series, 209 (2.8%) shoulders were noted to have fatty infiltration of the teres minor. The rate of isolated fatty infiltration of the teres minor was 0.4%. Concomitant deltoid muscle atrophy was common, and occurred in 68% of the shoulders with fatty infiltration of the teres minor. Tearing of the teres minor tendon was extremely rare. Conclusion Fatty infiltration of the teres minor can occur in isolation, be associated with deltoid muscle atrophy only, or occur in the setting of rotator cuff full tears. Thus, fatty infiltration of the teres minor may be related to a neurologic process or disuse. Further long term longitudinal studies are necessary to be elucidate the etiologies. Level of Evidence Level IV.

Introduction Dysfunction of the distal radioulnar joint (DRUJ) can be significantly debilitating. The Sauve-Kapandji (S-K) procedure can be indicated to address multiple etiologies of DRUJ dysfunction. The purpose of this study was to review our institution’s results performing the S-K procedure for DRUJ dysfunction in terms of clinical and radiographic outcomes, as well as complications and reoperations. Methods A retrospective review of S-K procedures performed at 2 institutions between 1998 and 2017 with a minimum of 1-year follow-up was performed. Preoperative and postoperative visual analog scale (VAS) pain, grip strength, and wrist range of motion were reviewed. Radiographs were reviewed for DRUJ healing, carpal translation, and radiocarpal degenerative changes. Results The cohort included 35 patients. The mean age was 51 years. The mean follow-up was 49.5 months. The postoperative range of motion was unchanged in regard to pronation, supination, and wrist extension. There was a decrease in wrist flexion from 43 degrees to 34 degrees. Successful union was noted in 100% of the wrists. There was 1 case (2.8%) of progressive ulnar translation and 4 major complications (11.3%). Conclusion The S-K procedure has several theoretical benefits compared to other procedures for DRUJ dysfunction with results of this study demonstrating excellent pain relief, improved postoperative grip strength, retained wrist pronation, supination, and extension, high rate of successful arthrodesis and low rate of major complications. Level of Evidence Level IV

Objective: To compare the clinical outcomes of static versus dynamic external fixation for elbow fracture-dislocations with persistent instability after surgical management. Design: Comparative, retrospective review. Setting: Two tertiary referral upper-extremity centers. Patients: Twenty-four elbows requiring external fixation for persistent elbow instability within 90 days of surgical management of an elbow fracture-dislocation. Intervention: Static and dynamic external fixation was used in 16 and 8 patients, respectively, for a median of 39 days (interquartile range, 33–48 days). Main Outcome Measurements: Elbow range of motion, complications, and revision surgeries. Results: Immediately after static and dynamic external fixation removal, there was no difference in elbow extension [33 degrees ± 16 degrees vs. 41 degrees ± 13 degrees, mean difference (MD) 7 degrees, 95% confidence interval (CI) −6 degrees–22 degrees] or flexion (114 degrees ± 35 degrees vs. 118 degrees ± 11 degrees, MD 4 degrees, 95% CI -23 degrees–132 degrees), respectively. At last follow-up, static and dynamic external fixation groups had no difference in elbow extension (27 degrees ± 13 degrees vs. 24 degrees ± 10 degrees, MD -3 degrees, 95% CI –15 degrees–7 degrees) or flexion (129 degrees ± 12 degrees vs. 128 degrees ± 14 degrees, MD -1 degree, 95% CI -13 degrees–10 degrees), respectively. Static and dynamic external fixation groups had no difference in complications [7 (44%) vs. 5 (63%), difference 19%, 95% CI -23%–54%] or revision surgeries [6 (38%) vs. 4 (50%), difference 13%, 95% CI -27%–49%]. Conclusions: No difference in range of motion, complications, and revision surgeries was detected after static versus dynamic external fixation of persistently unstable elbow fracture-dislocations. Due to ease of application, static external fixation is our preferred treatment for these injuries. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Background: There is limited literature regarding the treatment of concomitant scapholunate ligament (SL) injuries in acute distal radius fractures (DRFs). We hypothesized that surgical treatment of SL injuries in adult patients with DRFs leads to improved functional outcomes. Methods: A retrospective review was made of 42 adult patients who underwent surgical treatment of a DRF with a SL injury between 2005 and 2013. In all, 39 of the 42 patients sustained an intra-articular DRF (AO B or C). SL injury was diagnosed by SL diastasis > 3 mm on posteroanterior (PA) radiographs, magnetic resonance imaging, or with wrist arthroscopy. Patients were divided into 3 groups: 23 had a SL repair and were treated within 21 days of injury (acute), 8 underwent SL repair greater than 21 days from injury (subacute/chronic), and 11 did not undergo repair (non-operative). Median overall time to clinical follow-up was 5.1 years. Mayo Wrist Scores (MWS) and Disabilities of the Arm, Shoulder and Hand (DASH) scores were used to evaluate functional outcome. Results: Clinical outcomes measured by the MWS at final follow-up (6 months-12 years) showed no significant differences between the 3 groups. Of patients treated acutely, 17.3% had good to excellent MWS. MWS at 1-year follow-up was 68.4, 70, and 64 in the acute, subacute/chronic, and non-operative groups, respectively. DASH scores were 16.7, 14.3, and 11.8 in the acute, subacute/chronic, and nonoperative groups, respectively, at a mean of 7.8 years. Conclusions: At mid-term follow-up, all 3 treatment groups had similar DASH scores to the general population. There were no statistical functional differences between any of the groups based upon MWS or DASH scores.