Periostin Is a Biomarker for Anterior Shoulder Instability: Proteomic Analysis of Synovial Fluid.

BACKGROUND: The incremental biological changes in the synovial microenvironment of the shoulder in acute and chronic instability that may contribute to joint degeneration are poorly understood. Proteomic analysis of synovial fluid in patients with shoulder instability may improve our understanding of proteins that are shed into shoulder synovial fluid after an injury. HYPOTHESIS: Injury-specific factors such as the direction of instability and the severity of glenoid and humeral bone loss are associated with the proteome of synovial fluid in patients with shoulder instability. STUDY DESIGN: Descriptive laboratory study. METHODS: Synovial fluid lavage samples were compared between patients with anterior (n = 12) and posterior (n = 8) instability and those without instability (n = 5). Synovial proteins were identified with liquid chromatography-tandem mass spectrometry. Orthogonal validation of protein targets found to be significant on tandem mass spectrometry was performed in a separate set of prospective patients with Western blotting. Data were processed and analyzed, and P values were adjusted with the Benjamini-Hochberg method for multiple comparisons. RESULTS: A total of 25 patients were included. Tandem mass spectrometry identified 720 protein groups in synovial fluid of patients with shoulder instability. There were 4 synovial proteins that were significantly expressed in patients with anterior instability relative to posterior instability: periostin (POSTN) (adjusted P value = .03; log fold change [logFc] = 4.7), transforming growth factor beta-induced protein ig-h3 (adjusted P value = .05; logFc = 1.7), collagen type VI alpha-3 chain (adjusted P value = .04; logFc = 2.6), and coagulation factor V (adjusted P value = .04; logFc = -3.3). Among these targets, POSTN showed a moderate correlation with the Hill-Sachs lesion size (r = 0.7). Prospective validation with Western blotting confirmed a significantly higher level of POSTN in synovial fluid of patients with anterior instability (P = .00025; logFc = 5.1). CONCLUSION: Proteomic analysis enriched our understanding of proteins that were secreted into shoulder synovial fluid of patients with shoulder instability. The identification of POSTN, a proinflammatory catabolic protein involved with tissue remodeling and repair, as a significant target in anterior shoulder instability is a novel finding. Therefore, further study is warranted to determine the role that POSTN may play in the progression of bone loss and posttraumatic osteoarthritis. CLINICAL RELEVANCE: Proteomic analysis of synovial fluid in patients with shoulder instability improved our understanding of this abnormality after an injury.

Rate of incidental findings on routine preoperative computed tomography for shoulder arthroplasty.

Background: Incidental findings are commonly noted in advanced imaging studies. Few data exist regarding the rate of incidental findings on computed tomography (CT) for preoperative shoulder arthroplasty planning. This study aims to identify the incidence of these findings and the rate at which they warrant further work-up to help guide orthopedic surgeons in counseling patients. Methods: A retrospective review was performed to identify patients with available preoperative shoulder CT who subsequently underwent shoulder arthroplasty procedures at a single institution between 2015 and 2021. Data including age, sex, and smoking status were obtained. Radiology reports for CTs were reviewed for incidental findings and categorized based on location, tissue type, and/or body system. The rate of incidental findings and the rate at which further follow-up was recommended by the radiologist were determined. Results: A total of 617 patients was identified. There were 173 incidental findings noted in 146 of these patients (23.7%). Findings ranged from pulmonary (59%), skin/soft tissue (16%), thyroid (13%), vascular (9%), spinal (2%), and abdominal (1%) areas. Of the pulmonary findings, 50% were pulmonary nodules and 47% were granulomatous disease. Overall, the final radiology report recommended further follow-up for 50% of the patients with incidental findings. Conclusions: Incidental findings are relatively common in preoperative CTs obtained for shoulder arthroplasty, occurring in nearly one-quarter of patients. Most of these findings are pulmonary in nature. Overall, half of the patients with incidental findings were recommended for further follow-up. These results establish population data to guide orthopedic surgeons in patient counseling. Level of evidence: III.

Musculoskeletal Biorepository: Establishment, Sustainment, and Tips for Success.

A biorepository, also referred to as a "biobank," is a collection of biologic samples that are stored for laboratory research. With the emergence of precision medicine, the importance of leveraging individual patient biomolecular signatures to improve diagnosis, prognosis, and treatment is becoming increasingly recognized. Successful development and sustainment of a biorepository provides the potential for transformative preclinical research. Establishing a biobank requires a team approach with involvement of the institutions' research laboratory team and regulatory body. Execution of research activities requires a coordinated team approach for case identification, consent process, data and specimen collection, specimen processing, and storage and archiving. The advancing fields of precision medicine and orthobiologics provide incredible opportunities for institutions to generate novel lines of inquiry in musculoskeletal diseases through a multiomics approach (genomic, transcriptomic, proteomic, microbiomic). In addition, a biobank is an important component of post-market surveillance for the rapidly emerging field of orthobiologics.

Modifiable and Nonmodifiable Risk Factors Associated with the Development of Recurrent Rotator Cuff Tears.

Nonoperative and operative strategies exist to manage rotator cuff pathology. Although surgical repair is successful for most patients, others may experience retear or nonhealing of the rotator cuff. Several modifiable and nonmodifiable risk factors are associated with an increased retear rate. The literature shows consistency and agreement regarding many of these risk factors, most notably, patient age, tear size, and rotator cuff muscular atrophy, whereas others remain controversial. It is important that shoulder surgeons are familiar with modifiable and nonmodifiable risk factors associated with retear, to better advise patients and optimize their chances of success following rotator cuff repair surgery.

Patient Initiated Discrimination and Harassment-A Descriptive Survey of Experiences Within a Single Academic Department.

Background: Diversity in orthopedics is lacking despite ongoing efforts to create a more inclusive workforce. Increasing diversity necessitates recruitment and retainment of underrepresented providers, which involves representation among leadership, mentorship initiatives, and development of a safe work environment. Discrimination and harassment behaviors are prevalent within orthopedics. Current initiatives aim to address these behaviors among peers and supervising physicians, but patients are an additional underrecognized source of these negative workplace behaviors. This report aims to establish the prevalence of patient-initiated discrimination and harassment within a single academic orthopedic department and establish methods to reduce these behaviors in the workplace. Methods: An internet-based survey was designed using the Qualtrics platform. The survey was distributed to all employees of a single academic orthopedic department including nursing staff, clerks, advanced practice providers, research staff, residents/fellows, and staff physicians. Survey was distributed on two occasions between May and June of 2021. The survey collected information on respondent demographics, experience with patient-initiated discrimination/harassment, and opinions regarding possible intervention methods. Fisher exact test was used for statistical analysis. Results: Over one half of survey respondents report observing or personally experiencing patient-initiated discrimination within our orthopedics department (57%, n=110). Nearly half of respondents report observing or personally experiencing patient-initiated harassment within our department (46%, n=80). Encounters with these behaviors were more commonly reported from resident and staff female physicians. The most frequently reported negative patient-initiated behaviors include gender discrimination and sexual harassment. Discordance exists regarding optimal methods to address these behaviors, but one third of respondents indicate potential benefit from visual aids throughout the department. Conclusion: Discrimination and harassment behaviors is common within orthopedics, and patients are a significant source of this negative workplace behavior. Identification of this subset of negative behaviors will allow us to provide patient education and provider response tools for the protection of orthopedic staff members. Ideally, minimizing discrimination/harassment behaviors within our field will help create a more inclusive workplace environment and allow continued recruitment of diverse candidates into our field. Level of Evidence: V.

Outcomes of Geriatric Periprosthetic Distal Femur Fractures: Comparison of Fixation Versus Reconstruction.

OBJECTIVE: Comparing outcomes of periprosthetic distal femur fractures treated with open reduction and internal fixation (ORIF) versus distal femoral replacement (DFR). SETTING: Three major academic hospitals within one metropolitan area. DESIGN: Retrospective. PATIENTS/PARTICIPANTS: Three hundred seventy patients >64 years old with periprosthetic distal femur fractures were identified and 115 were included (65 ORIF vs. 50 DFR). INTERVENTION: ORIF with locked plating versus DFR. MAIN OUTCOME MEASUREMENT: One-year mortality, ambulatory status at 1 year, reoperations, and hospital readmissions. RESULTS: No differences were observed between ORIF and DFR cohorts regarding demographics or medical history, including Charleston Comorbidity Index. DFR was associated with longer hospital stay (6.09 days ORIF vs. 9.08 days DFR, P < 0.001) and more frequent blood transfusion (12.3% ORIF vs. 44.0% DFR, P < 0.001). Logistic regression analysis using propensity score matching (PSM) demonstrated no statistically significant difference in reoperation, hospital readmission, ambulatory status at 1 year, or 1-year mortality between the 2 cohorts. Finally, applying Bayesian model averaging using PSM to identify risk factors for 1-year mortality demonstrated that increasing age, length of index hospital stay, and 90-day hospital readmission were significantly associated with 1-year mortality, regardless of type of surgical treatment. CONCLUSION: Rehospitalization, reoperation, ambulatory status, and 1-year mortality are no different between ORIF and DFR in the treatment of geriatric periprosthetic distal femur fractures when PSM is applied to mitigate selection bias. Further study is warranted to elucidate functional outcomes, long-term sequelae, and costs of care related to these treatment options to better guide treatment planning. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

A Surgical Framework for the Management of Incomplete Axillary Nerve Injuries.

BACKGROUND: Axillary nerve injury is the most common nerve injury affecting shoulder function. Nerve repair, grafting, and/or end-to-end nerve transfers are used to reconstruct complete neurotmetic axillary nerve injuries. While many incomplete axillary nerve injuries self-resolve, axonotmetic injuries are unpredictable, and incomplete recovery occurs. Similarly, recovery may be further inhibited by superimposed compression neuropathy at the quadrangular space. The current framework for managing incomplete axillary injuries typically does not include surgery. METHODS: This study is a retrospective analysis of 23 consecutive patients with incomplete axillary nerve palsy who underwent quadrangular space decompression with additional selective medial triceps to axillary end-to-side nerve transfers in 7 patients between 2015 and 2019. Primary outcome variables included the proportion of patients with shoulder abduction M3 or greater as measured on the Medical Research Council (MRC) scale, and shoulder pain measured on a Visual Analogue Scale (VAS). Secondary outcome variables included pre- and postoperative Disabilities of the Arm, Shoulder, and Hand Questionnaire (DASH) scores. RESULTS: A total of 23 patients met the inclusion criteria and underwent nerve surgery a mean 10.7 months after injury. Nineteen (83%) patients achieved MRC grade 3 shoulder abduction or greater after intervention, compared with only 4 (17%) patients preoperatively (p = 0.001). There was a significant decrease in VAS shoulder pain scores of 4.2 ± 2.5 preoperatively to 1.9 ± 2.4 postoperatively (p < 0.001). The DASH scores also decreased significantly from 48.8 ± 19.0 preoperatively to 30.7 ± 20.4 postoperatively (p < 0.001). Total follow-up was 17.3 ± 4.3 months. CONCLUSION: A surgical framework is presented for the appropriate diagnosis and surgical management of incomplete axillary nerve injury. Quadrangular space decompression with or without selective medial triceps to axillary end-to-side nerve transfers is associated with improvement in shoulder abduction strength, pain, and DASH scores in patients with incomplete axillary nerve palsy.

Increasing Awareness of Complications of Nerve Injury Following Shoulder Surgery: Preventing Delays in Referral and Treatment.

BACKGROUND: Nerve injuries remain a challenging complication after shoulder surgery. While most resolve spontaneously, some require surgical intervention. This study describes the characteristics of patients sustaining nerve injuries following shoulder surgery, evaluates referral patterns to nerve surgeons, and characterizes nerve surgeries performed and their outcomes. Increased awareness of these injuries allows patients and providers to be better informed regarding the appropriate management when these complications occur. METHODS: A retrospective review of referrals with nerve injuries following shoulder surgery between 2007 and 2015 was performed. The final analysis included 65 patients. Data reviewed included demographics, procedure and anesthesia type, and diagnosis of nerve injury. Time to referral to nerve surgeon and proportional changes in the Disabilities of the Arm, Shoulder, and Hand (DASH) scores were determined. Outcomes were categorized as failed, partially successful, and successful based on final follow-up. RESULTS: Patients were referred following arthroscopic shoulder surgeries (35.4%), shoulder arthroplasties (24.6%), open shoulder procedures (21.5%), and combined open and arthroscopic procedures (18.5%). The mean time to referral was 7.6 months. Nerve injuries involved brachial plexus (33) and individual and multiple peripheral nerve branches (23 and 7, respectively). Twenty-five (38%) nerve injuries demonstrated spontaneous recovery. Thirty-five patients underwent surgical intervention, of which 27 were successful, 3 were partially successful, and 3 failed. CONCLUSIONS: This is the largest series of patients with iatrogenic nerve injury following shoulder surgeries to date. Our data demonstrate a lack of timely referral to nerve surgeons, especially after arthroscopy. There continues to be a variable injury pattern even among similar surgeries. Despite this, timely surgical intervention, when indicated, can lead to favorable outcomes.

Current Concept Review: Risk Factors for Infection Following Open Fractures.

Infection following open fracture is a significant source of morbidity and mortality. Therefore, a central tenet of treatment is to minimize the risk of infection. The initial risk of infection is determined by wound characteristics, such as size, soft tissue coverage, vascular injury, and contamination. While no consensus exists on optimal antibiotic regimen, early administration of prophylactic antibiotics, within an hour of injury, when possible, has been shown definitively to decrease the risk of infection. Infection risk is further reduced by early irrigation with normal saline and aggressive debridement of devitalized tissue. Patient factors that increase risk of infection following open fracture include diabetes mellitus, smoking, male gender, and lower extremity fracture.

Physician-Patient Communication in the Orthopedic Clinic: Surgeon-Identified Challenges.

Background: Effective communication between the physician and the patient is crucial to quality healthcare. The orthopedic surgery clinic setting provides an environment for cultivating the physician-patient relationship, eliciting diagnostic data, and developing treatment strategies. However, little is known about the orthopedic surgeon perspective on communicating with patients. The purpose of the study was to identify patient communication and care issues faced in the orthopedic surgery clinic setting that physicians categorize as challenging. Methods: All surgeons in the department of orthopedics in a large tertiary care center were invited to respond to an online survey on common communication challenges. Physicians were asked to rate 13 challenges identified by the literature and opinion leaders using a four-point Likert scale ranging from "Not at all challenging" to "Extremely challenging". In addition, the survey included open ended questions regarding common challenges in communicating with patients and types of encounters, and thematic analysis was applied. Mean scores were calculated. Results: Nineteen orthopedic surgeons completed the survey and were included in the analysis. Orthopedic surgeons identified misaligned expectations for surgical intervention for a nonsurgical diagnosis as the most challenging encounter in the clinic (16/19). Managing postoperative patient expectations (14/19) and communicating with patients who were dissatisfied with their surgical outcome (13/19) were also commonly rated as particularly challenging. Open ended responses echoed these ratings and additional difficulty facilitating patient understanding of complex information as common communication challenges. Conclusion: Common challenges in the orthopedic clinic often surround managing patient expectations and providing effective explanations, particularly where physicians perceive a surgical intervention as inappropriate for addressing the patient complaint. Identifying these issues can guide training efforts to help orthopedic physicians in managing these and improving communication. These findings can also provide basis for collecting information about communication challenges from orthopedic surgeons across institutions. Level of Evidence: IV.

Standardizing Screw Head Orthopaedic Trauma Implants. Is There an Interest? An OTA Member Survey.

OBJECTIVE: To determine the level of interest in standardization of design for fracture fixation implants within the orthopaedic trauma community. METHODS: A survey regarding implant removal concerns and implant design preferences was electronically distributed to members of Orthopaedic Trauma Association (OTA). RESULTS: Three hundred thirty respondents participated in the survey (response rate of 19%) Only 2.4% of respondents indicated a consistent ability to identify the implant vendor and/or manufacturer of retained implants in the preoperative planning phase of care; >75% of respondents reported investing a minimum of an additional 30 minutes to their operative times to remove screw(s) to successfully extract a plate. More than 80% of respondents reported multiple occurrences requiring modification of their surgical plans because of implants that could not be removed, preventing the completion of the planned procedure. The majority of respondents expressed interest in the adoption of standardized locking head screws for mini, small, and large screw sizes sets (63.5%); 84.8% of respondents desire standardization of screw head and driver sizes across the industry. Also, 83.6% of respondents expressed interest in the adoption of a standardized locking screw head for each cannulated screw, regardless of manufacturer. CONCLUSIONS: Members of the orthopaedic community, as represented in the membership of the OTA, are interested in the adoption of universal standards in implant design. Establishing standard screw heads and drivers will optimize the delivery of operative care.

Influence of subscapularis stiffness with glenosphere lateralization on physiological external rotation limits after reverse shoulder arthroplasty.

BACKGROUND: Repair of the subscapularis following reverse shoulder arthroplasty (RSA) remains a controversial topic among surgeons. Poor rotator cuff muscle quality is associated with increased musculotendinous stiffness, and the subsequent effect of compromised tissue repair on RSA functional outcomes remains unclear. The objective was to investigate the influence of subscapularis stiffness together with glenoid component lateralization on pre- and postimpingement joint mechanics during external rotation after RSA. METHODS: A validated finite element model incorporating the Zimmer Trabecular Metal reverse system was used. The deltoid and subscapularis tendon were tensioned and wrapped around the joint prior to controlled shoulder external rotation. Baseline subscapularis stiffness, determined from cadaveric testing, was varied to 80%, 120% and 140% of baseline, to simulate a range of pliability associated with fatty infiltration and fibrosis. We evaluated the effects of varying subscapularis stiffness and the corresponding variation in joint tension with varying glenosphere lateralization (2, 4, and 10 mm) on the torque required to externally rotate the shoulder and the impingement/subluxation risk. RESULTS: Prior to any impingement, the torques required to externally rotate the shoulder ranged from 22-47 Nm across the range of parameters studied, with the greatest torques required for the 10-mm glenosphere lateralization. The impact of increasing subscapularis stiffness on torque requirements was most pronounced at the 10-mm lateralization, as well. A 20% increase in subscapularis stiffness necessitated a 7%-14% increase in preimpingement torque, whereas a 40% stiffness increase was associated with a 12%-27% increase in torque. Torque was proportional to lateralization. When lateralization was increased from 2 to 4 mm, the preimpingement torque increased by 10%-13%, whereas a 10-mm lateralization necessitated a 35%-62% torque increase relative to 2 mm of lateralization. Increased subscapularis stiffness did not limit impingement-free range of motion or substantially decrease postimpingement subluxation in this model. DISCUSSION: Mechanical gains achieved through lateralization may be hindered by increased torque demands, especially when a stiffer subscapularis is repaired. As lateralization increases subscapularis tension, greater torque is required to externally rotate the shoulder. The torque required for external rotation has been reported between 15-50 Nm. Subscapularis repair with the simulated increases in stiffness requires relative increases in torque that the reconstructed shoulder may not be able to physically produce to rotate the glenohumeral joint, particularly at 10-mm lateralization. These results suggest that subscapularis repair may not be indicated in cases where a lateralized glenoid component is used and the subscapularis is compromised.

Artificial Intelligence to Identify Arthroplasty Implants From Radiographs of the Knee.

BACKGROUND: Revisions and reoperations for patients who have undergone total knee arthroplasty (TKA), unicompartmental knee arthroplasty (UKA), and distal femoral replacement (DFR) necessitates accurate identification of implant manufacturer and model. Failure risks delays in care, increased morbidity, and further financial burden. Deep learning permits automated image processing to mitigate the challenges behind expeditious, cost-effective preoperative planning. Our aim was to investigate whether a deep-learning algorithm could accurately identify the manufacturer and model of arthroplasty implants about the knee from plain radiographs. METHODS: We trained, validated, and externally tested a deep-learning algorithm to classify knee arthroplasty implants from one of 9 different implant models from retrospectively collected anterior-posterior (AP) plain radiographs from four sites in one quaternary referral health system. The performance was evaluated by calculating the area under the receiver-operating characteristic curve (AUC), sensitivity, specificity, and accuracy when compared with a reference standard of implant model from operative reports. RESULTS: The training and validation data sets were comprised of 682 radiographs across 424 patients and included a wide range of TKAs from the four leading implant manufacturers. After 1000 training epochs by the deep-learning algorithm, the model discriminated nine implant models with an AUC of 0.99, accuracy 99%, sensitivity of 95%, and specificity of 99% in the external-testing data set of 74 radiographs. CONCLUSIONS: A deep learning algorithm using plain radiographs differentiated between 9 unique knee arthroplasty implants from four manufacturers with near-perfect accuracy. The iterative capability of the algorithm allows for scalable expansion of implant discriminations and represents an opportunity in delivering cost-effective care for revision arthroplasty.

New versus old: 95 degree angled blade plate versus distal femoral locking plate. A randomized clinical trial.

INTRODUCTION: The purpose was to compare the locking condylar plate (LCP) with the 95° angled blade plate (ABP) for distal femoral fracture patterns amenable to either device. Our hypothesis was that LCP would outperform ABP with primary outcome of nonunion and secondary outcomes of reoperation and malunion. METHODS: 78 adult patients with 79 eligible fractures and mean age of 60 years were prospectively randomized to LCP (n = 45) or ABP (n = 34). Mean ISS was 16. 22% fractures were open. Patient-reported functional outcomes were assessed with the Musculoskeletal Function Assessment (MFA). RESULTS: All patients were followed to union, and mean follow-up was 25 months. There were no differences in age, sex, fracture pattern, co-morbidities or mechanism for the two groups. Three patients had infections, one superficial after LCP and one deep infection each after ABP and LCP. Three patients developed nonunion after LCP versus none after ABP (p = 0.06). Nine patients healed with minor deformity after LCP versus 5 following ABP. One fracture had major deformity after ABP versus two after LCP. Eight patients had a secondary procedure following LCP versus two after ABP (p = 0.05). CONCLUSIONS: The investigation failed to support newer technology being better. Evidence did not indicate the LCP was superior to the ABP. Trends for primary union and fewer secondary procedures suggest that ABP may have superior performance to LCP for fracture patterns which may be treated with either implant.

Influence of Interfacial Bonding on the Mechanical and Impact Properties Ring-Opening Metathesis Polymer (ROMP) Silica Composites.

Polymers formed by ring-opening metathesis polymerization (ROMP) such as poly(dicyclopentadiene) (pDCPD) exhibit a technologically desirable combination of high toughness, high glass transition temperature, and outstanding low-temperature performance. However, because of their nonpolar molecular structure, they tend to suffer from relatively low elastic moduli and poor adhesion to common fillers, fibers, and substrates, limiting their utility as adhesives and composite binders without specialized bonding agents. Here, we investigate the mechanical properties of a pDCPD-based copolymer filled with well-defined spherical microparticles having four distinct surface chemistries capable of strong, moderate, or weak bonding to the matrix with surfaces ranging from polar to nonpolar. Measurements in uniaxial tension, quasi-static fracture, and high-velocity impact are complemented by digital image correlation (DIC), scanning electron microscopy (SEM) fractography, and X-ray computed tomography (X-µCT) of subcritically loaded crack tips, yielding insight into the complex roles played by interfacial bonding in strength, stiffness, and toughening mechanisms of an already tough polymer. Analysis using quantitative fracture and impact mechanism models provided valuable guidelines for designing heterogeneous systems that combine structural and tough performance.