Tokish, John M.

Abstract Glenohumeral bone loss is a significant risk factor for recurrent instability after shoulder dislocation. The Hill‐Sachs lesion is an osseous defect of the posterior humeral head that is commonly recognized after anterior shoulder dislocation. Several procedures exist to address humeral‐sided bone loss, including soft tissue filling procedures, osteoarticular allografts, bone plugs, rotation osteotomies, and humeral head replacements. However, among the most common of these procedures is the arthroscopic remplissage. This technique involves capsulotenodesis of the posterior shoulder capsule and infraspinatus tendon into a Hill‐Sachs lesion. Previously described techniques use knotted suture anchors. In this report, we describe a modified technique for remplissage using knotless, all‐suture anchors to perform capsulotenodesis of a Hill‐Sachs lesion. Benefits of this technique include a single skin incision, improved bone preservation, and easier facilitation of revision surgery if required. Technique Video video See video under supplementary data.

Background: With a hip abductor tendon tear, widening of the intergluteal space, or “fat stripe,” is a characteristic change seen in and around the gluteus medius and minimus. Purpose: To determine the relationship of the intergluteal fat stripe in hips with pathologic abductor tears compared with the contralateral side and to evaluate the association of fat stripe size with hip-specific patient-reported outcome measures. Study Design: Case series; Level of evidence, 4. Methods: Of the 43 patients (42 female, 1 male; mean age, 56.6 years; range, 38-85 years) who underwent endoscopic gluteus medius repair, 19 met inclusion criteria of preoperative bilateral hip magnetic resonance imaging (MRI) scans and 2-year follow up. A single board-certified fellowship-trained orthopaedic surgeon (J.F.), who was blinded to outcomes, evaluated the MRI scans to measure the intergluteal fat stripe on the operative and nonoperative sides. The 2-year postoperative International Hip Outcome Tool (iHOT-12) and modified Harris Hip Score (mHHS) values were analyzed to determine their relationship to the size of the fat stripe. Statistical analysis was performed using a paired t test, and associations were determined using Pearson product correlation as well as nonparametric measurements. Results: The size of the intergluteal fat stripe differed significantly between the operative and nonoperative sides. The area of the fat stripe on the operative side was 645.73 ± 513.09 mm 2 , and on the nonoperative side it was 313.47 ± 360.71 mm 2 , an average of 332.36 mm 2 greater than the nonoperative side ( P = .02). The width of the fat stripe was 9.10 ± 4.60 mm on the operative side and 5.15 ± 3.87 mm on the nonoperative side, 3.95 mm greater than the nonoperative side ( P < .01). There was no correlation between the width or area of the fat stripe on the operative side and iHOT-12 or mHHS values at 2-year follow-up. Conclusion: The study findings indicated that the intergluteal fat stripe is significantly wider and has a significantly larger area in hips with abductor tears compared with unaffected hips. This did not correlate with 2-year patient-reported outcomes.

BACKGROUND Despite increased awareness of factors related to athletic performance and injury prevention, youth and adolescent baseball players continue to report injuries at alarming rates. Upper extremity muscle strength is an integral part of physical assessment and injury prevention in baseball players, however minimal data exists in youth populations. Changes in anthropometric measures, inherent in physically developing athletes, have been shown to impact strength measures, however normalization methodology is rarely reported. PURPOSE The purposes of this study were to 1) compare the measurement properties of five potential methods for normalizing isometric shoulder strength in a cohort of 9-12 year old male baseball players and 2) examine the relationship between normalized isometric shoulder strength and ball velocity in a cohort of 9-12 year old male baseball players. STUDY DESIGN Prospective cohort study (n=159) METHODS Baseline and follow up height, weight and bilateral ulnar length measurements were assessed followed by isometric strength in both the dominant and non-dominant shoulders. Strength measures included scapular plane abduction (scaption), external rotation (ER) at 0°, ER and internal rotation (IR) at 90°. Ball velocity was assessed as a measure of throwing performance. Intraclass correlation coefficients (ICC2,1), standard errors of measurement (SEM) and minimal detectable change (MDC95) were calculated for all strength measures. Repeated measures ANOVA were conducted comparing changes in normalized strength using five separate anthropometric measures: weight, height, body mass index, ulnar length and % of non-dominant shoulder strength. Linear regression models were used to examine the relationships between normalized isometric shoulder strength and ball velocity. Statistical significance was set a priori at α=0.05. RESULTS Shoulder strength normalized using ulnar length was the only method that demonstrated excellent reliability (ICC2,1 0.98-0.99) and detected significant changes between strength in each of the four measures tested (SEM 0.39-0.69 Nm). Modest but significant correlations were observed between scaption and ball velocity (r2 = 0.27, p < 0.001) and ER at 0° and ball velocity (r2 = 0.23, p < 0.001). CONCLUSION Ulnar length was the most stable and reliable normalization method for assessing isometric shoulder strength in youth baseball players. In addition, normalized scaption strength was the most significant predictor of ball velocity, followed by ER at 0° strength in this population. LEVEL OF EVIDENCE Level 2b (etiology)

This biomechanical study evaluates the performance of a solid titanium-alloy intra-medullary ( IM) clavicular screw in torsion and cantilever bending in cadaveric clavicle specimens with simulated simple oblique and butterfly wedge midshaft fractures. Thirty-two fresh-frozen male clavicles were sorted into six experimental groups: Torsion Control, Torsion Simple Oblique Fracture, Torsion Butterfly Wedge Fracture, Bending Control, Bending Simple Oblique Fracture, and Bending Butterfly Wedge Fracture. The experimental groups were controlled for density, length, diameter, and laterality. All other samples were osteotomy-induced and implanted with a single 90 mm × 3 mm clavicle screw. All groups were tested to physiologically relevant cutoff points in torsion or bending. There were no statistically significant differences in the performance of the oblique and butterfly wedge fracture models for any torsion or bend testing measures, including maximum torsional resistance ( p = 0.66), torsional stiffness ( p = 0.51), maximum bending moment ( p = 0.43), or bending stiffness ( p = 0.73). Torsional testing of samples in the direction of thread tightening tended to be stronger than samples tested in loosening, with all groups either approaching or achieving statistical significance. There were no significant differences between the simple oblique or the butterfly-wedge fracture groups for any of the tested parameters, suggesting that there is no difference in the gross biomechanical properties of the bone-implant construct when the IM clavicle screw is used in either a simple midshaft fracture pattern or a more complex butterfly wedge fracture pattern.

Abstract Orthoregeneration is defined as a solution for orthopaedic conditions that harnesses the benefits of biology to improve healing, reduce pain, improve function, and optimally, provide an environment for tissue regeneration. Options include drugs, surgical intervention, scaffolds, biologics as a product of cells, and physical and electro‐magnetic stimuli. The goal of regenerative medicine is to enhance the healing of tissue after musculoskeletal injuries as both isolated treatment and adjunct to surgical management, using novel therapies to improve recovery and outcomes. Various orthopaedic biologics (orthobiologics) have been investigated for the treatment of pathology involving the shoulder including the rotator cuff tendons, glenohumeral articular cartilage, glenoid labrum, the joint capsule, and bone. Promising and established treatment modalities include hyaluronic acid (HA); platelet‐rich plasma (PRP) and platelet rich concentrates (PRC); bone marrow aspirate (BMA) comprising mesenchymal stromal cells (MSCs alternatively termed medicinal signaling cells and frequently, misleadingly labelled “mesenchymal stem cells”); MSC harvested from adipose, umbilical, or placental sources; factors including vascular endothelial growth factors (VEGF), basic fibroblast growth factor (FGF), platelet‐derived growth factor (PDGF), transforming growth factor‐beta (TGFβ), bone morphogenic protein (BMP), and matrix metalloproteinases (MMPs); prolotherapy; pulsed electromagnetic field therapy; microfracture and other marrow‐stimulation techniques; biologic resurfacing using acellular dermal allografts, allograft Achilles tendons, allograft lateral menisci, fascia lata autografts, and porcine xenografts; osteochondral autograft or allograft); and autologous chondrocyte implantation (ACI). Studies involving hyaluronic acid, platelet rich plasma, and medicinal signaling cells of various origin tissues have shown mixed results to‐date as isolated treatments and as surgical adjuncts. Despite varied results thus far, there is great potential for improved efficacy with refinement of current techniques and translation of burgeoning preclinical work. Level of Evidence Level V, expert opinion.

Purpose We create a viable, mechanically expanded autograft long head biceps tendon (LHBT) scaffold for biologically augmenting the repair of torn rotator cuffs. Methods The proximal aspect of the tenotomized LHBTs was harvested from patients during rotator cuff repair surgery and was mechanically formed into porous scaffolds using a surgical graft expander. LHBT scaffolds were evaluated for change in area, tensile properties, and tenocyte viability before and after expansion. The ability of endogenous tenocytes derived from the LHBT scaffold to promote tenogenic differentiation of human adipose‐derived mesenchymal stromal cells (ADMSCs) was also determined. Results Autograft LHBTs were successfully expanded using a modified surgical graft expander to create a porous scaffold containing viable resident tenoctyes from patients undergoing rotator cuff repair. LHBT scaffolds had significantly increased area (length: 24.91 mm [13.91, 35.90] × width: 22.69 mm [1.87, 34.50]; P = .011) compared with the native LHBT tendon (length: 27.16 mm [2.70, 33.62] × width: 6.68 mm [5.62, 7.74]). The structural properties of the autograft were altered, including the ultimate tensile strength (LHBT scaffold: .56 MPa [.06, 1.06] vs. native LHBT: 2.35 MPa [1.36, 3.33]; P = .002) and tensile modulus (LHBT scaffold: 4.72 MPa [−.80, 1.24] versus native LHBT: 37.17 MPa [24.56, 49.78]; P = .001). There was also a reduction in resident tenocyte percent viability (LHBT scaffold: 38.52% [17.94, 59.09] vs. native LHBT: 68.87% [63.67, 74.37]; P =.004). Tenocytes derived from the LHBT scaffold produced soluble signals that initiated ADMSC differentiation into an immature tenocyte‐like phenotype, as indicated by an 8.7× increase in scleraxis ( P = .040) and a 3.6× increase in collagen type III mRNA expression ( P = .050) compared with undifferentiated ADMSC controls. Conclusions The ability to produce a viable autologous scaffold from the proximal biceps tendon having dimensions, porosity, mechanical characteristics, native ECM components, and viable tenocytes that produce bioactive signals conducive to supporting the biologic augmentation of rotator cuff repair surgery has been demonstrated. Clinical Relevance This biologically active construct may help to improve the quality of healing and regeneration at the repair site of rotator cuff tears, especially those at high risk for retear.

Purpose To describe the complications that occur following biologic therapeutic injections. Methods We queried physician members of the Biologic Association, a multidisciplinary organization dedicated to providing a unified voice for all matters related to musculoskeletal biologics and regenerative medicine. Patients included in this study must have (1) received a biologic injection, (2) sustained an adverse reaction, and (3) had a minimum of 1‐year follow‐up after the injection. Patient demographic information, medical comorbidities, diagnoses, and previous treatments were recorded. The type of injection, injection setting, injection manufacturers, and specific details about the complication and outcome were collected. Results In total, 14 patients were identified across 6 institutions in the United States (mean age 63 years, range: 36‐83 years). The most common injections in this series were intra‐articular knee injections (50%), followed intra‐articular shoulder injections (21.4%). The most common underlying diagnosis was osteoarthritis (78.5%). Types of injections included umbilical cord blood, platelet‐rich plasma, bone marrow aspirate concentrate, placental tissue, and unspecified “stem cell” injections. Complications included infection (50%), suspected sterile inflammatory response (42.9%), and a combination of both (7.1%). The most common pathogen identified from infection cases was Escherichia coli (n = 4). All patients who had isolated infections underwent treatment with at least one subsequent surgical intervention (mean: 3.6, range: 1‐12) and intravenous antibiotic therapy. Conclusions This study demonstrates that serious complications can occur following treatment with biologic injections, including infections requiring multiple surgical procedures and inflammatory reactions. Level of Evidence Level IV, case series.

Background The primary objective of the present study was to investigate how preoperative imaging modalities including 3D computed tomography (CT) scans with preoperative planning software affect implant choice for shoulder arthroplasty. Methods X-ray, uncorrected 2D CT scans, and 3D CT scans from 21 patients undergoing primary arthroplasty were reviewed by five shoulder surgeons. Each surgeon measured glenoid version, inclination and humeral head subluxation, and then selected an anatomic or reverse shoulder arthroplasty implant based only on these imaging parameters. Each surgeon virtually positioned the implant. Agreement between surgeons and changes in plan for individual surgeons between imaging modalities were assessed. Results Average measurements of native version, inclination, and subluxation were similar across all imaging modalities with very good interobserver reliability. Overall, there was a high rate of variability in choice of implant depending on imaging modality. Agreement on implant selection between surgeons improved from 68.6% using x-ray to 80.0% with 3D CT. Introducing age added significant variability, reducing agreement on implant choice to 61.0% with 3D CT. Conclusions The use of preoperative 3D planning changes implant choice in nearly one-third of cases compared to plain radiographs and improves surgeon agreement on implant choice compared to x-ray and 2D CT. Level of evidence: III.

Purpose To report the annual incidence of anterior shoulder instability (ASI) diagnosis, injury severity, and surgical stabilization in a U.S. population. Methods An established U.S. geographic database was used to identify patients < 40 years old with diagnoses of ASI from 1994‐2016. Medical records were reviewed to obtain patient demographics, histories, imaging results, and surgical details. Age‐ and sex‐specific incidence rates were calculated and adjusted to the 2010 U.S. population. Poisson regression was performed to examine trends by timeline, sex and age. Results The study population consisted of 652 patients with ASI and a mean age of 21.5 years (range, 3.6‐39.5). Comparing 2015‐2016 to 1994‐1999, we found an increase in the number of dislocations (from 1.0‐1.9; P = 0.016) and total instability events (from 2.3‐3.4; P = 0.041) per patient prior to presentation to a physician. There was a trend in increased diagnosis of bony Bankart and/or Hill‐Sachs on MRI over time, with these lesions documented in 96% of patients undergoing MRI in 2015‐2018 compared to 52.9% in 1994‐1999 ( P < .001). The use of arthroscopic procedures increased and peaked in 2005‐2009 (90% of surgical cases performed). The proportion of open Latarjet procedures increased from 2010‐2014 (14%) and 2015‐2018 (31%). Conclusions The age‐ and sex‐ adjusted incidence of ASI diagnosis in a U.S. population from 1994‐2016 is comparable to that demonstrated in Canadian and European populations. This study demonstrates an increasing number of instability events prior to surgical evaluation, which may correlate with patients’ more commonly presenting with bone loss and requiring more aggressive surgical treatment or that ASI is being more frequently cared for and documented by present‐day orthopedic surgeons. Level of Evidence Level III, cross‐sectional study.

Abstract Introduction Musculoskeletal injuries are an endemic amongst U.S. Military Service Members and significantly strain the Department of Defense’s Military Health System. The Military Health System aims to provide Service Members, military retirees, and their families the right care at the right time. The Military Orthopedics Tracking Injuries and Outcomes Network (MOTION) captures the data that can optimize musculoskeletal care within the Military Health System. This report provides MOTION structural framework and highlights how it can be used to optimize musculoskeletal care. Materials and Methods MOTION established an internet-based data capture system, the MOTION Musculoskeletal Data Portal. All adult Military Health System patients who undergo orthopedic surgery are eligible for entry into the database. All data are collected as routine standard of care, with patients and orthopedic surgeons inputting validated global and condition-specific patient reported outcomes and operative case data, respectively. Patients have the option to consent to allow their standard of care data to be utilized within an institutional review board approved observational research study. MOTION data can be merged with other existing data systems (e.g., electronic medical record) to develop a comprehensive dataset of relevant information. In pursuit of enhancing musculoskeletal injury patient outcomes MOTION aims to: (1) identify factors which predict favorable outcomes; (2) develop models which inform the surgeon and military commanders if patients are behind, on, or ahead of schedule for their targeted return-to-duty/activity; and (3) develop predictive models to better inform patients and surgeons of the likelihood of a positive outcome for various treatment options to enhance patient counseling and expectation management. Results This is a protocol article describing the intent and methodology for MOTION; thus, to date, there are no results to report. Conclusions MOTION was established to capture the data that are necessary to improve military medical readiness and optimize medical resource utilization through the systematic evaluation of short- and long-term musculoskeletal injury patient outcomes. The systematic enhancement of musculoskeletal injury care through data analyses aligns with the National Defense Authorization Act (2017) and Defense Health Agency’s Quadruple Aim, which emphasizes optimizing healthcare delivery and Service Member medical readiness. This transformative approach to musculoskeletal care can be applied across disciplines within the Military Health System.