Sánchez‐Sotelo, Joaquín

Objectives: Osteochondritis dissecans (OCD) of the humeral capitellum is an often painful condition that typically affects the adolescent athlete. There is little consensus on treatment and a scarcity of long-term outcomes data. The purpose of this study was to (1) report the long-term outcomes associated with both operative and non-operative management of capitellar OCD, (2) identify factors associated with failure of non-operative management, and (3) determine whether delay in surgery affects final outcomes. Methods: All patients diagnosed with OCD of the capitellum from 1995-2020 within a defined geographic cohort were included. Medical records, imaging studies, and operative reports were manually reviewed to record demographic data, treatment strategies, and outcomes. Surgical treatment was considered delayed if it occurred more than 6 months after symptom onset. Results: A total of 50 elbows with a mean follow-up of 9.4 years were included. Of these, 7 (14%) were treated non-operatively and never underwent surgery during follow-up, while 43 (86%) underwent surgical intervention: 27 had early surgery and 16 underwent delayed surgery after ≥ 6 months of non-operative treatment. When compared to non-operative management, surgical management resulted in superior MEPI scores (90 vs 83, p=0.05), decreased persistence of mechanical symptoms (9% vs 50%, p<0.01), and better elbow flexion (141° vs 131°, p=0.01) at long-term follow up. Older patients had a trend toward increased failure of non-operative management (p=0.06). The presence of an intra-articular loose body strongly predicted failure of non-operative management (p=0.01; OR 13). Plain radiography and MRI had poor sensitivities for identifying loose bodies (27% and 40%, respectively). Differences in outcomes following early versus delayed surgical management were not demonstrated. Conclusions: Patients with capitellar OCD initially treated nonoperatively failed nonoperative management 70% of the time. Elbows that did not undergo surgery had slightly increased symptoms and decreased functional outcomes compared to those treated surgically. In this cohort, the greatest predictors for failure of non-operative treatment were older age and presence of a loose body; however, an initial trial of non-operative treatment did not adversely impact the success of future surgery at long term follow-up. [Table: see text][Table: see text][Table: see text][Table: see text]

Purpose To (1) report the long‐term outcomes associated with both operative and nonoperative management of capitellar osteochondritis dissecans (OCD), (2) identify factors associated with failure of nonoperative management, and (3) determine whether delay in surgery affects final outcomes. Methods All patients who received a diagnosis of capitellar OCD from 1995‐2020 within a geographic cohort were included. Medical records, imaging studies, and operative reports were manually reviewed to record demographic data, treatment strategies, and outcomes. The cohort was divided into 3 groups: (1) nonoperative management, (2) early surgery, and (3) delayed surgery. Delayed surgery (surgery ≥6 months after symptom onset) was considered failure of nonoperative management. Results Fifty elbows with a mean follow‐up period of 10.5 years (median, 10.3 years; range, 1‐25 years) were studied. Of these, 7 (14%) were definitively treated nonoperatively, 16 (32%) underwent delayed surgery after at least 6 months of failed nonoperative treatment, and 27 (54%) underwent early surgical intervention. When compared with nonoperative management, surgical management resulted in superior Mayo Elbow Performance Index pain scores (40.1 vs 33, P = .04), fewer mechanical symptoms (9% vs 50%, P < .01), and better elbow flexion (141° vs 131°, P = .01) at long‐term follow‐up. Older patients trended toward increased failure of nonoperative management ( P = .06). The presence of an intra‐articular loose body predicted failure of nonoperative management ( P = .01; odds ratio, 13). Plain radiography and magnetic resonance imaging had poor sensitivities for identifying loose bodies (27% and 40%, respectively). Differences in outcomes after early versus delayed surgical management were not observed. Conclusions Nonoperative management of capitellar OCD failed 70% of the time. Elbows that did not undergo surgery had slightly more symptoms and decreased functional outcomes compared with those treated surgically. The greatest predictors of failure of nonoperative treatment were older age and presence of a loose body; however, an initial trial of nonoperative treatment did not adversely impact the success of future surgery. Level of Evidence Level III, retrospective cohort study.

AbstractDeep learning has the potential to be one of the most transformative technologies to impact orthopedic surgery. Substantial innovation in this area has occurred over the past 5 years, but clinically meaningful advancements remain limited by a disconnect between clinical and technical experts. That is, it is likely that few orthopedic surgeons possess both the clinical knowledge necessary to identify orthopedic problems, and the technical knowledge needed to implement deep learning‐based solutions. To maximize the utilization of rapidly advancing technologies derived from deep learning models, orthopedic surgeons should understand the steps needed to design, organize, implement, and evaluate a deep learning project and its workflow. Equipping surgeons with this knowledge is the objective of this three‐part editorial review. Part I described the processes involved in defining the problem, team building, data acquisition, curation, labeling, and establishing the ground truth. Building on that, this review (Part II) provides guidance on pre‐processing and augmenting the data, making use of open‐source libraries/toolkits, and selecting the required hardware to implement the pipeline. Special considerations regarding model training and evaluation unique to deep learning models relative to “shallow” machine learning models are also reviewed. Finally, guidance pertaining to the clinical deployment of deep learning models in the real world is provided. As in Part I, the focus is on applications of deep learning for computer vision and imaging.

AbstractArthrofibrosis, which is characterized by excessive scar tissue and limited motion, can complicate the daily functioning of patients after total knee arthroplasty (TKA). Molecular hallmarks of arthrofibrosis include pathologic accumulation of myofibroblasts and disproportionate collagen deposition. Epigenetic mechanisms, including posttranslation modification of histones, control gene expression and may regulate fibrotic events. This study assessed the role of the bromodomain and extra‐terminal (BET) proteins on myofibroblast differentiation. This group of epigenetic regulators recognize acetylated lysines and are targeted by a class of drugs known as BET inhibitors. RNA‐seq analysis revealed robust mRNA expression of three BET members (BRD2, BRD3, and BRD4) while the fourth member (BRDT) is not expressed in primary TKA knee outgrowth fibroblasts. RT‐qPCR and western blot analyses revealed that BET inhibition with the small molecule JQ1 impairs TGFβ1‐induced expression of ACTA2, a key myofibroblast marker, in primary outgrowth knee fibroblasts. Similarly, JQ1 administration also reduced COL3A1 mRNA levels and collagen deposition as monitored by picrosirius red staining. Interestingly, the inhibitory effects of JQ1 on ACTA2 mRNA and protein expression, as well as COL3A1 expression and collagen deposition, were paralleled by siRNA‐mediated depletion of BRD4. Together, these data reveal that BRD4‐mediated epigenetic events support TGFβ1‐mediated myofibroblast differentiation and collagen deposition as seen in arthrofibrosis. To our knowledge, these are the first studies that assess epigenetic regulators and their downstream events in the context of arthrofibrosis. Future studies may reveal clinical utility for drugs that target epigenetic pathways, specifically BET proteins, in the prevention and treatment of arthrofibrosis.

Aims As has been shown in larger animal models, knee immobilization can lead to arthrofibrotic phenotypes. Our study included 168 C57BL/6J female mice, with 24 serving as controls, and 144 undergoing a knee procedure to induce a contracture without osteoarthritis (OA). Methods Experimental knees were immobilized for either four weeks (72 mice) or eight weeks (72 mice), followed by a remobilization period of zero weeks (24 mice), two weeks (24 mice), or four weeks (24 mice) after suture removal. Half of the experimental knees also received an intra-articular injury. Biomechanical data were collected to measure passive extension angle (PEA). Histological data measuring area and thickness of posterior and anterior knee capsules were collected from knee sections. Results Experimental knees immobilized for four weeks demonstrated mean PEAs of 141°, 72°, and 79° after zero, two, and four weeks of remobilization (n = 6 per group), respectively. Experimental knees demonstrated reduced PEAs after two weeks (p < 0.001) and four weeks (p < 0.0001) of remobilization compared to controls. Following eight weeks of immobilization, experimental knees exhibited mean PEAs of 82°, 73°, and 72° after zero, two, and four weeks of remobilization, respectively. Histological analysis demonstrated no cartilage degeneration. Similar trends in biomechanical and histological properties were observed when intra-articular violation was introduced. Conclusion This study established a novel mouse model of robust knee contracture without evidence of OA. This was appreciated consistently after eight weeks of immobilization and was irrespective of length of remobilization. As such, this arthrofibrotic model provides opportunities to investigate molecular pathways and therapeutic strategies. Cite this article: Bone Joint Res 2023;12(1):58–71.

Background: Arthroscopic debridement for osteochondritis dissecans (OCD) lesions of the capitellum is a relatively common and straightforward surgical option for failure of nonoperative management. However, the long-term outcomes of this procedure remain unknown. Hypothesis: Arthroscopic debridement of capitellar OCD would provide satisfactory long-term improvement in patient-reported outcomes. Study Design: Case series; Level of evidence, 4. Methods: Patients aged ≤18 years who underwent arthroscopic debridement procedures for OCD lesions (International Cartilage Repair Society grades 3 and 4) were identified. Procedures included loose body removal when needed and direct debridement of the lesion; marrow stimulation with drilling or microfracture was added at the discretion of each surgeon. The cohort consisted of 53 elbows. Patient evaluation included visual analog scale for pain; motion; subjective satisfaction; Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) scores; reoperation; and rate of return to sports. Results: At a mean 11 years of follow-up (range, 5-23 years), the median visual analog scale score for pain was 0, and 96% of patients reported being improved as compared with how they were before surgery. The mean ± SD QuickDASH score was 4 ± 9 points (range, 0-52 points), and 80% of patients returned to their sports of interest. The arc of motion significantly improved from 115°± 28° preoperatively to 130°± 17° at latest follow-up ( P = .026). Seven elbows (13%) required revision surgery for OCD lesions, resulting in high rates of overall survivorship free of revision surgery: 90% (95% CI, 80%-96%) at 5 years and 88% (95% CI, 76%-94%) at 10 years. At final follow-up, 7 all-cause reoperations were performed without revision surgery on the OCD lesion. Conclusion: Arthroscopic debridement of grade 3 or 4 OCD lesions of the capitellum produced satisfactory patient-reported outcomes in a majority of elbows, although a subset of patients experienced residual symptoms. The inherent selection bias of our cohort should be considered when applying these results to the overall population with OCD lesions, as we do not recommend this procedure for all patients.

Background: There are limited data on the incidence of capitellar osteochondritis dissecans (OCD) in the United States (US) population. Purpose: To determine the incidence of symptomatic capitellar OCD in a representative US subpopulation and identify changes in its incidence over time and to investigate the relationship between the incidence of capitellar OCD and patient sex and age. Study Design: Descriptive epidemiology study. Methods: A retrospective review was performed of patients aged ≤24 years from Olmsted County, Minnesota, with symptomatic capitellar OCD over a 25-year period (1995-2019). Patients with acute osteochondral injuries, Panner disease, and hereditary arthropathy were excluded. Poisson regression was utilized to identify the predictors of a capitellar OCD diagnosis. Incidence rates (per 100,000) were assessed for changes over time. Age groups of younger (10-15 years) versus older (16-24 years) patients were compared. Results: A total of 45 patients (78% male) were identified. The mean age was 14.5 years (range, 10-24 years); 31 patients were in the younger group, and 14 patients were in the older group. Sport participation was seen in 89%of patients; 90% were overhead athletes, and 58% were throwing athletes. The incidence of capitellar OCD was 6.0 per 100,000 overall, 9.5 per 100,000 for male patients, and 2.6 per 100,000 for female patients. The incidence was highest for male patients in the younger group (15.3/100,000) and lowest for female patients in the older group (0.8/100,000). The estimated incidence rate ratio for younger versus older patients was 3.3 ( P < .001), and the incidence rate ratio for male versus female patients was 3.5 ( P < .001). There were no changes in the incidence of capitellar OCD over time as a continuous or 5-year categorical variable ( P = .290 and P = .460, respectively). Overall, 82% of patients were treated surgically. There were no significant changes in surgical rates over time. Conclusion: In this US subpopulation, the overall incidence of symptomatic capitellar OCD between the ages of 10 and 24 years was 6.0 per 100,000 over the 25-year period studied, which is higher than previously reported US estimates. Incidence rates and treatment strategies did not change significantly over time.

Objectives: Distal biceps tendon tears, although rare, significantly impair patient’s elbow mobility and function. There is a paucity of contemporary literature reporting long term outcomes of distal biceps (DB) injuries. Therefore, the authors sought to identify magnetic resonance imaging (MRI) confirmed distal bicep tears and report on (1) patient demographics and injury characteristics of all patients with distal bicep pathology, (2) outcomes of all patients with non-operatively managed DB pathology, and (3) outcomes of all patients with operatively managed DB pathology. Methods: Patients with an MRI-confirmed distal biceps rupture from 1996 to 2016 were identified through an institutional image database. Patients from the initial search were then cross-referenced with the [REDACTED] 1 to ensure record availability. Patients were included if they had complete medical records and ≥5 years of clinical follow-up. Patients with inflammatory arthritis and enthesitis, polytrauma, or incidental findings without clinical assessment were excluded. Medical records were reviewed to confirm the diagnosis of distal biceps tears and obtain further subject details. Results: A total of 158 patients (22 female, 136 male) with a mean age 51.5 years (44.8-61.2) were identified and included. Baseline patient demographics including BMI, smoking status, dominant-handedness, laborer occupation, and gender were gathered (Table 1). Patients had a mean clinical follow-up of almost 14 years (Table 1, range 8.4 -17.8). Outcomes of the 52 non-operative and 106 operatively managed patients, included severe complications, functional outcomes, and health-related productivity loss are reported in Table 2. There were 7 re-operations (4%), 5 re-ruptures (3%), and overall 35% of the operatively treated cohort experienced a complication. Conclusions: Patients with distal bicep pathology tended to be a male laborer in their 50s without clinically significantly associated risk factors. The majority of patients regained full ROM, and 83% were able to return to work without modifications, irregardless of operative or non-operative management. At long term follow up, patients treated operatively were more likely to report missing time from work and averaged more days missed than their non-operatively treated counterparts. Additionally, operative patients had no statistically significant gains functional outcomes, and were subject to potential post-operative complications. Surgeon bias may play a role in deciding treatment for distal biceps tears. As such, careful patient selection for surgical intervention for distal biceps pathology should be employed; surgeons should consider restricting surgical intervention to patients who have significant clinical symptoms or fail non-operative management. [Table: see text][Table: see text]

Objectives: Distal biceps tendon tears, although rare, significantly impair patient’s elbow mobility and function. There is a paucity of literature reporting outcomes of partial thickness tears to inform management strategies. Therefore, the authors sought to identify magnetic resonance imaging (MRI) confirmed partial thickness distal biceps tears and report on (1) demographics and treatment strategies, (2) outcomes and complications, and (3) any identifiable risk factors for progression to surgery or full thickness tear. Methods: Patients who experienced a partial thickness distal biceps tear confirmed on MRI from 1996 to 2016 were identified by a musculoskeletal radiologist through an institutional image database. Patients were included if they had complete medical records and at least one visit of clinical follow-up. Patients with inflammatory arthritis and enthesitis, polytrauma, or incidental findings without clinical assessment were excluded. Medical records were reviewed to confirm the diagnosis and obtain study details. Multivariate logistic regression models were created using baseline characteristics, injury details and physical exam findings in order to predict operative intervention. Results: Overall, 111 patients (22F, 89M, age: 53.6 years ± 13) were identified and included. Baseline injury characteristics and patient demographics including weakness in elbow flexion, forearm supination, and patient reported sensation at time of injury were all found to be statistically different between treatment groups (Table 1). Patients were followed to a mean of 10 years of clinical follow up. Within the cohort, 57 patients were treated non-operatively, while 54 were treated operatively. Patients who received surgical intervention were more likely to report missing time from work and greater loss of productivity due to missed time (Table 2); however, almost 90% of patients returned to work without restrictions, regardless of treatment modality (88% vs 88%, Table 2). For surgical patients, there were 5 re-operations (9%), 3 re-ruptures (6%), and overall, 31% of the operatively treated cohort experienced a complication. Results of the final multivariate logistic regression model are included in Table 3; final model variables included age at initial consult, tenderness to palpation tendon insertion on exam, and supination weakness. Of these, supination weakness at initial consult was found to be a statistically significant predictor for surgical intervention (p=.001, OR=24.8). Conclusions: Operative patients tended to be male with more profound supination weakness; these patients tended to report increased loss of productivity due to time missed after treatment. At 10 year clinical follow up 31% experienced some complication and 9% underwent a re-operation. However, patients demonstrated uniform ability to return to work without modification and no statistical differences in functional outcomes, regardless of treatment modality. Patients who suffer from a partial distal biceps tear should be counseled that operative management represents a balance of returning function with potential complications and increased loss of productivity. [Table: see text][Table: see text][Table: see text]