Citations

Abstract Background Endoprostheses (EPC) are often utilized for reconstruction of the proximal humerus with either hemiarthroplasty (HA) or reverse arthroplasty (RA) constructs. RA constructs have improved outcomes in patients with primary lesions, but no studies have compared techniques in metastatic disease. The aim of this study is to compare functional outcomes and complications between HA and RA constructs in patients undergoing endoprosthetic reconstruction for proximal humerus metastases. Methods We retrospectively reviewed our institutional arthroplasty database to identify 66 (56% male; 38 HA and 28 RA) patients with a proximal humerus reconstruction for a non‐primary malignancy. The majority (88%) presented with pathologic fracture, and the most common diagnosis was renal cell carcinoma (48%). Resultss Patients with RA reconstructions had better postoperative forward elevation (74° vs. 32°, p < 0.01) and higher functional outcome scores. HA patients had more complications (odds ratio 13, p < 0.01), with instability being the most common complication. Conclusions Patients with nonprimary malignancies of the proximal humerus had improved functional outcomes and fewer complications after undergoing reconstruction with a reverse EPC compared to a HA EPC. Preference for reverse EPC should be given in patients with good prognosis and ability to complete postoperative rehabilitation.

Abstract Purpose The Optimizing Performance Through Intrinsic Motivation and Attention for Learning (OPTIMAL) theory postulates that directing attention to the intended movement effect or outcome (external focus) is more effective than directing attention to the internal body motion or body part (internal focus). This study compared external versus internal focus of attention as novice students learned ultrasound-guided peripheral cannulation. The authors hypothesized that conditions promoting an external (vs internal) focus of attention would result in better performance on immediate and delayed (retention) testing. Method The authors conducted a randomized, experimental study from October 2022 to February 2023 comparing external and internal focus using ultrasound-guided peripheral venous cannulation followed by practice using an ultrasound training block. Undergraduate health science students performed 4 practice trials with instructions to focus on the needle tip (external focus) or their hands (internal focus), followed by immediate and delayed (retention) assessment 2 weeks later. The primary outcome was time to successful cannulation. Results were compared using Kaplan-Meier curves and parametric survival analysis regression (accelerated failure time) models. Results Seventy participants completed the immediate assessment. The external focus group completed successful cannulation a mean of 2.33 times faster (95% confidence interval [CI], 1.47–3.67; P &lt; .001) than those in the internal focus group (median time, 12.0 vs 29.5 seconds). Results also favored the external focus group during practice, with the external focus group successfully completing the task a mean of 1.83 times faster (95% CI, 1.04–3.21; P = .04) than the internal focus group. In the retention assessment, the external focus group successfully completed the task a mean of 2.37 times faster (95% CI, 1.19–4.74; P = .02) than the internal focus group. Conclusions External focus of attention compared with internal focus of attention improves medical motor skill learning in novice learners.

AbstractAdipoRon is an adiponectin receptor 1, 2 (ADIPOR1 and ADIPOR2) agonist with potential antifibrotic effects. Whether AdipoRon can mitigate joint stiffness in a rabbit model of arthrofibrosis is unknown. We examined the efficacy of intravenous (IV) AdipoRon at mitigating contracture in a rabbit model of knee arthrofibrosis. Fifty‐six female New Zealand White rabbits were divided into three dosing groups: vehicle (dimethyl sulfoxide, DMSO), 2.5 mg/kg AdipoRon, and 5 mg/kg AdipoRon. AdipoRon, in DMSO, was administered IV preoperatively and for 5 days postoperatively (30 rabbits, Aim 1). AdipoRon was again dosed similarly after Kirschner wire (K‐wire) removal at 8 weeks (26 rabbits; Aim 2). The primary outcome of joint passive extension angle (PEA,°) was measured at 8, 10, 12, 16, and 24 weeks following index surgery. At 24 weeks, rabbits were euthanized and limbs were harvested to measure posterior capsular stiffness (N cm/°). In Aim 1, the 5 mg/kg treated rabbits had a significant increase in PEA when compared to controls at 16‐week (p < 0.05). In Aim 2, the 5 mg/kg treated rabbits had a significant increase in PEA when compared to controls at 10‐week (p < 0.05). In both aims, no significant differences were observed at later time points. Capsular stiffness was no different in any group. We are the first to report the efficacy of IV AdipoRon in a rabbit model of arthrofibrosis. We identified a significant dose‐dependent decrease in joint PEA at early time points; however, no differences were observed between groups at later time points. Clinical Significance: The present investigation provided the first assessment of AdipoRon's efficacy in mitigating knee stiffness in the current gold standard rabbit model of arthrofibrosis. Results of this investigation provided further evidence as to the potential role of AdipoRon as a preventative for arthrofibrosis in large mammals.

» The proximal humerus is a common location for primary bone tumors, and the goal of surgical care is to obtain a negative margin resection and subsequent reconstruction of the proximal humerus to allow for shoulder function. » The current evidence supports the use of reverse total shoulder arthroplasty over hemiarthroplasty when reconstructing the proximal humerus after resection of a bone sarcoma if the axillary nerve can be preserved. » There is a lack of high-quality data comparing allograft prosthetic composite (APC) with endoprosthetic reconstruction of the proximal humerus. » Reverse APC should be performed using an allograft with donor rotator cuff to allow for soft-tissue repair of the donor and host rotator cuff, leading to improvements in shoulder motion compared with an endoprosthesis.

AbstractArthrofibrosis, which causes joint motion restrictions, is a common complication following total knee arthroplasty (TKA). Key features associated with arthrofibrosis include myofibroblast activation, knee stiffness, and excessive scar tissue formation. We previously demonstrated that adiponectin levels are suppressed within the knee tissues of patients affected by arthrofibrosis and showed that AdipoRon, an adiponectin receptor agonist, exhibited anti‐fibrotic properties in human mesenchymal stem cells. In this study, the therapeutic potential of AdipoRon was evaluated on TGFβ1‐mediated myofibroblast differentiation of primary human knee fibroblasts and in a mouse model of knee stiffness. Picrosirius red staining revealed that AdipoRon reduced TGFβ1‐induced collagen deposition in primary knee fibroblasts derived from patients undergoing primary TKA and revision TKA for arthrofibrosis. AdipoRon also reduced mRNA and protein levels of ACTA2, a key myofibroblast marker. RNA‐seq analysis corroborated the anti‐myofibrogenic effects of AdipoRon. In our knee stiffness mouse model, 6 weeks of knee immobilization, to induce a knee contracture, in conjunction with daily vehicle (DMSO) or AdipoRon (1, 5, and 25 mg/kg) via intraperitoneal injections were well tolerated based on animal behavior and weight measurements. Biomechanical testing demonstrated that passive extension angles (PEAs) of experimental knees were similar between vehicle and AdipoRon treatment groups in mice evaluated immediately following immobilization. Interestingly, relative to vehicle‐treated mice, 5 mg/kg AdipoRon therapy improved the PEA of the experimental knees in mice that underwent 4 weeks of knee remobilization following the immobilization and therapy. Together, these studies revealed that AdipoRon may be an effective therapeutic modality for arthrofibrosis.

AimsThe scapula is a rare site for a primary bone tumour. Only a small number of series have studied patient outcomes after treatment. Previous studies have shown a high rate of recurrence, with functional outcomes determined by the preservation of the glenohumeral joint and deltoid. The purpose of the current study was to report the outcome of patients who had undergone tumour resection that included the scapula.MethodsWe reviewed 61 patients (37 male, 24 female; mean age 42 years (SD 19)) who had undergone resection of the scapula. The most common resection was type 2 (n = 34) according to the Tikhoff-Linberg classification, or type S1A (n = 35) on the Enneking classification.ResultsThe ten-year disease-specific survival was 76%. High tumour grade (hazard ratio (HR) 4.27; p = 0.016) and a total resection of the scapula (HR 3.84; p = 0.015) were associated with worse survival. The ten-year metastasis-free and local recurrence-free survivals were 82% and 86%, respectively. Total scapular resection (HR 6.29; p = 0.004) was associated with metastatic disease and positive margins were associated with local recurrence (HR 12.86; p = 0.001). At final follow-up, the mean shoulder forward elevation and external rotation were 79° (SD 62°) and 27° (SD 25°), respectively. The most recent functional outcomes evaluated included the mean Musculoskeletal Tumor Society Score (76% (SD 17%)), the American Shoulder and Elbow Score (73% (SD 20%)), and the Simple Shoulder Test (7 (SD 3)). Preservation of the glenoid (p = 0.001) and scapular spine (p < 0.001) improved clinical outcomes; interestingly, preservation of the scapular spine without the glenoid improved outcomes (p < 0.001) compared to preservation of the glenoid alone (p = 0.05).ConclusionResection of the scapula is a major undertaking with an oncological outcome related to tumour grade, and a functional outcome associated with the status of the scapular spine and glenoid. Positive resection margins are associated with local recurrence.Cite this article: Bone Joint J 2023;105-B(12):1314–1320.

Background: Traditionally, the reconstruction of severe distal humeral bone loss at the time of revision total elbow arthroplasty (TEA) has used allograft-prosthetic composites (APCs) stabilized with cerclage wires or cables. We have migrated to plate fixation when revision TEA using a humeral APC is performed. This study shows the outcomes of patients treated with a humeral APC with plate fixation during revision TEA. Methods: Between 2009 and 2019, 41 humeral APCs with plate fixation of distal humeral allograft to the native humerus were performed in the setting of revision TEA. There were 12 male patients (29%) and 29 female patients (71%), with a mean age of 63 years (range, 41 to 87 years). The mean allograft length was 12 cm. All elbows had a minimum follow-up of 2 years (mean follow-up, 3.3 years). Patients were evaluated for visual analog scale pain scores, range of motion, the ability to perform select activities of daily living, and the Mayo Elbow Performance Score (MEPS). Outcomes including reoperations, complications, and revisions were noted. The most recent radiographs were evaluated for union at the allograft-host interface, failure of the plate-and-screw construct, or component loosening. Results: The mean postoperative flexion was 124° (range, 60° to 150°) and the mean postoperative extension was 26° (range, 0° to 90°); the mean arc of motion was 99° (range, 30° to 150°). The mean MEPS was 58 points (range, 10 to 100 points). Two surgical procedures were complicated by neurologic deficits. The overall reoperation rate was 14 (34%) of 41. Of the 33 patients with complete radiographic follow-up, 12 (36%) had evidence of nonunion at the allograft-host interface with humeral component loosening, 1 (3%) had evidence of partial union, and 1 (3%) had ulnar stem loosening. Conclusions: Revision TEA with a humeral APC using compression plating was successful in approximately two-thirds of the elbows. Further refinement of surgical techniques is needed to improve union rates in these complex cases. Level of Evidence: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Background: Glenoid baseplate malpositioning during reverse total shoulder arthroplasty can contribute to perimeter impingement, dislocation, and loosening. Despite advances in preoperative planning, conventional instrumentation may lead to considerable inaccuracy in implant positioning unless patient-specific guides are used. Optical navigation has the potential to improve accuracy and precision when implanting a reverse shoulder arthroplasty baseplate. This systematic review aimed to analyze the most recent evidence on the accuracy and precision of glenoid baseplate positioning using intraoperative navigation and its potential impact on component selection and surgical time. Methods: We conducted a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. The PubMed, Scopus, and EMBASE databases were queried in July 2022 to identify all studies that compared navigation vs. conventional instrumentation for reverse shoulder arthroplasty. Data of deviation from the planned baseplate version and inclination, the use of standard or augmented glenoid components, and surgical time were extracted. Quantitative analysis from the included publications was performed using the inverse-variance approach and Mantel-Haenszel method. Results: Of the 2,048 records identified in the initial query, only 10 articles met the inclusion and exclusion criteria, comprising 667 shoulders that underwent reverse total shoulder arthroplasty. The pooled mean difference (MD) of the deviation from the planned baseplate position for the clinical studies was −0.44 (95% confidence interval [CI], −3.26; p = 0.76; I 2 = 36%) for version and −8.75 (95% CI, −16.83 to −0.68; p = 0.02; I 2 = 83%) for inclination, both in favor of navigation. The odds ratio of selecting an augmented glenoid component after preoperative planning and navigation-assisted surgery was 8.09 (95% CI, 3.82-17.14; p < 0.00001; I 2 = 60%). The average surgical time was 12 minutes longer in the navigation group (MD 12.46, 95% CI, 5.20-19.72; p = 0.0008; I 2 = 71%). Conclusions: Preoperative planning integrated with computer-assisted navigation surgery seems to increase the accuracy and precision of glenoid baseplate inclination compared with the preoperatively planned placement during reverse total shoulder arthroplasty. The surgical time and proportion of augmented glenoid components significantly increase when using navigation. However, the clinical impact of these findings on improving prosthesis longevity, complications, and patient functional outcomes is still unknown. Level of Evidence: Level III , systematic review and meta-analysis. See Instructions for Authors for a complete description of levels of evidence.

Abstract An efficient 2-D continuum finite element method (FEM), including the rigid body algorithm and our previously developed contact element, was formulated for the contact stress analysis of articular joints. This FEM can calculate the contact pressure distribution on articular surfaces and stress distribution inside of cartilage. This method can model geometric and material nonlinearities for both the static and dynamic situations. The major advantage of this method is that only the soft cartilage requires finite element (FE) mesh, while the bony structure can be modeled as a rigid body due to its relatively rigid nature. Since much less degrees of freedom are now required in FEM, much faster computing speed can be achieved.

Background: Osteochondritis dissecans (OCD) of the capitellum can be a disabling condition that typically affects adolescent, overhead athletes. To date, a variety of different surgical treatment options have been described. Indications: Surgical indications for osteochondral allograft transplantation (OCA) for capitellar OCD lesions include failure of nonsurgical management or prior surgery and unstable, full-thickness lesions of almost any size affecting both bone and cartilage. The anconeus preserving approach specifically provides wide access to nearly the entire capitellum and can be used for lesions in almost any location. Technique Description: The anconeus preserving approach for OCA utilizes the interval between the anconeus and the ulna. With the patient positioned supine and the elbow flexed on an arm table, an incision is made approximately 1 cm lateral to the olecranon and is carried down to the fascia. Electric cautery is used to dissect the interval between the ulna and the anconeus. The anconeus is elevated off the ulna and retracted laterally to expose the underlying joint capsule. An L-shaped capsulotomy is performed over the center of the capitellum, just proximal to the annular ligament of the radial head. A pin is placed into the center of the lesion, perpendicular to the capitellum. A cannulated reamer 0.5 mm smaller than the lesion is used to ream the lesion to a depth of approximately 5 mm. Depth measurements are taken at all 4 poles of the defect. About 3 cc of bone marrow aspirate harvest is then obtained from the ulna using a cannulated needle. The oscillating saw is used to cut the graft to size using the prior measurements. The bone marrow aspirate is placed onto the osseous side of the graft before the osteochondral graft is impacted into the recipient site. The capsulotomy is then closed, and the anconeus is repaired back to the ulna. Postoperatively, patients begin range of motion as soon as tolerated, initiate strengthening at 6 weeks, and initiate return-to-sport programming at 3 months. Results: Lesions treated with OCA typically demonstrate improvement in all outcome measures, including functional scores, graft incorporation, articular surface congruity, and return-to-sport. Complications and graft failure is rare. Discussion/Conclusion: OCA using an anconeus preserving approach is a reliable option for surgical management of unstable OCD lesions. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.