Moran, Steven L.

Background: The treatment for Kienböck disease varies widely based on the status of the lunate. To date, there is no consensus regarding the optimal treatment for patients with coronal plane fractures of the lunate, or Lichtman Stage IIIC. Therefore, the purpose of this study was to assess whether coronal plane fractures of the lunate in Kienböck disease healed after surgical intervention, and to determine the outcomes after surgical fixation of the lunate compared with treatment with salvage procedures. Methods: A retrospective review of 36 patients with Lichtman IIIC Kienböck disease was conducted. Patients were classified into lunate reconstruction (vascularized bone graft [VBG] or non-VBG) or salvage procedures (proximal row carpectomy [PRC] or limited fusion). Preoperative and postoperative visual analog scale (VAS) pain, range of motion, grip strength, and Mayo Wrist Score (MWS) were analyzed. Radiographs and computed tomographic scans were reviewed for Lichtman stage, fracture location, union, modified carpal height ratio, Stahl index, and radioscaphoid angle. Results: Thirteen patients underwent lunate reconstruction, 13 underwent limited fusion, and 10 underwent PRC. The overall union rate was 45% after lunate reconstruction, with average time to union of 7 months. There were no differences in union rates between VBG and non-VBG. All 3 groups experienced improvement in their postoperative grip strength and MWS. There were no statistically significant differences in preoperative to postoperative changes in clinical outcome measures between the 3 cohorts; however, when we compared lunate reconstruction with all patients who underwent salvage procedures (limited carpal fusion and PRC), we noted the latter had improved functional outcomes ( P = .019). Four patients (31%) in the reconstruction cohort and 2 patients (8%) in the limited carpal fusion group required reoperation at latest follow-up. Conclusions: Union rate of coronal plane fractures in Kienböck disease remains variable. While the proportion of patients requiring reoperation was higher in the reconstruction group, all groups of patients experienced improvement in their clinical outcomes, without a significant difference between cohorts.

Knowledge of the adaptation of the soft tissue to mechanical factors and biomolecules would be essential to better understand the mechanism of tendon injury and to improve the outcome of tendon repair. The responses to these factors could be different for the distinct types of cells in the tendon: cells from the tendon sheath, fibroblasts from the epitenon surface, or fibroblasts from the internal endotenon. In this study, we examined the mechanical and histological characteristics of the rate of contraction of the collagen gel seeded with epitenon and endotenon fibroblasts. The rate of contraction and the mechanical property of the contracted construct depend on the gel concentration and also the treatment of TGF-β 1 .

Degenerative wrist conditions, such as scapholunate advanced collapse and scaphoid nonunion advanced collapse, often require salvage procedures to reduce pain and improve function. For early stages of disease, both proximal row carpectomy and scaphoid excision four-corner arthrodesis are viable motion-preserving options. There remains controversy on which technique is superior. Selection is a nuanced decision that requires consideration of patient characteristics and stage of disease. The traditional notion that proximal row carpectomy should be reserved for older individuals with low demands has been challenged; long-term studies in younger populations demonstrate similar patient-reported outcomes, pain relief and survivorship without conversion to total wrist arthrodesis between proximal row carpectomy and four-corner arthrodesis. The existing evidence suggests proximal row carpectomy has advantages of greater range of motion, fewer complications and lower costs. Advancements such as arthroscopic techniques for both procedures show potential, although mastery involves a steep learning curve.

AbstractThis study aimed to compare the clinically established autologous extrasynovial tendon graft to a newly developed tissue‐engineered allograft (Eng‐allograft) in terms of functional outcomes following flexor tendon reconstruction in a canine model. The second and fifth flexor digitorum profundus (FDP) tendons from 16 dogs were transected and repaired in Zone II. After 6 weeks of cage activity, the repaired tendons were intentionally ruptured, creating a clinically relevant model for reconstruction. The re‐ruptured FDP tendons were then reconstructed using either the clinically standard autologous extrasynovial tendon graft or the Eng‐allograft, which had been revitalized with autologous bone marrow‐derived mesenchymal stem cells (BMSCs) and synovialized using carbodiimide derivatized synovial fluid (cd‐SYN). Following 12 weeks of postoperative rehabilitation, the functional outcomes of the surgical digits were evaluated. The Eng‐allograft group exhibited improved digital function, including lower digit work of flexion and reduced adhesion status, while maintaining similar tendon gliding resistance compared to the autograft group. However, the failure load of both the distal and proximal host/graft conjunctions in the Eng‐allograft group was significantly lower than that of the autograft group with higher graft rupture at the host−graft junction. In conclusion, the decellularized allogenic intrasynovial tendon, when revitalized BMSCs and synovialized with cd‐SYN, demonstrates positive effects on digital function improvement and adhesion reduction. However, the healing at both proximal and distal graft/host junctions is far lower than the autograft. Further research is needed to enhance the healing capacity of allograft conjunctions, aiming to achieve a comparable level of healing seen with autografts.

» 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.

Abstract Background Hemiarthroplasty may be indicated for patients with distal radioulnar joint (DRUJ) arthritis. Recently, the use of the pyrocarbon metacarpophalangeal implant has been proposed as a novel means of treating DRUJ arthritis due to the materials improved mechanical properties and wear characteristics. Purpose This study compares midterm outcomes of metallic and pyrocarbon hemiarthroplasties for the treatment of symptomatic DRUJ arthritis. Questions of interest included outcomes and complications. Materials and Methods In total, 32 hemiarthroplasties, 10 metallic and 22 pyrocarbon, were performed between 2010 and 2020 by three surgeons at one tertiary medical center. Patients' retrospective outcomes were extracted from the electronic medical record. Results Postoperatively, the metallic implant group (mean follow-up: 38 months) demonstrated decreased pain but no changes in range of motion. Comparatively, the pyrocarbon group experienced an improved range of motion and postoperative pain (p < 0.05). Radiographic analysis demonstrated 10% of metallic implants and 9% of pyrocarbon implants to have resulted in thinning of the lateral cortex of the radius at the final follow-up. Minor complications in metallic and pyrocarbon implant groups warranting reoperation occurred at rates of 10 and 13.5% while implant failure occurred at a rate of 30 and 18%, respectively. Discussion Within this study, pyrocarbon implants resulted in significant functional improvement with comparable complication and failure rates to the metallic implant. Long-term stability demonstrated efficacy for both techniques in symptomatic DRUJ treatment. Type of Study/Level of Evidence Observational Case Series IV.

Introduction: Platelets are heavily implicated in angiogenesis; however, the underlying mechanism remains relatively uncharacterized. The goal of this study was to evaluate the angiogenic potency of a platelet-derived regenerative exosome product (PEP) in an effort to develop a novel treatment for peripheral arterial disease. Here, we evaluated the mechanistic basis of PEP in angiogenesis and it’s use In Vivo in a rodent hind limb ischemia model. Methods/Results: Under Current Good Manufacturing Practices, conditioned medium from apheresis platelet cultures was purified to acquire the exosomes. PEP, enriched in exosome markers CD63, CD9 and Flotillin, induced human umbilical vein endothelial cell (HUVEC) proliferation, migration, and vascular tube formation In Vitro. Proteomic evaluation of PEP highlighted receptor tyrosine kinase (RTK) pathways and western blot validation demonstrated induction of phospho-MAPK and phospho-AKT following PEP treatment of HUVECs. Systematic evaluation of RTK receptor involvement was performed using small molecule inhibitors and receptor knock-down in HUVECs, ruling out RTK activation as a mode of action. However, small molecule inhibition of PI3 kinase demonstrated elimination of PEP-induced AKT phosphorylation and reduction in PEP-induced angiogenesis In Vitro measured by HUVEC proliferation and migration. In Vivo, evaluation of angiogenesis was performed in a rodent model of hindlimb ischemia treated with PEP embedded in fibrin glue (PEP/TISSEEL). Blood flow was evaluated by SPY angiography on day 0 pre- and post-operation, day 21, and day 28. Animals treated with PEP/TISSEEL showed a significant increase in blood flow compared to sham and TISSEEL treated animals (percent perfusion at 28 days: sham 40.9%, TISSEEL 44.3%, PEP/TISSEEL 100.2%), with significant increase in vascular area on histology (at 28 days vascular area (μm 2 )/muscle area(μm 2 ): healthy control 12.71, sham 4.66, TISSEEL 4.76, PEP/TISSEEL 15.54). Conclusions: Exosome driven activation of PI3 kinase can induce angiogenesis both In Vitro and In Vivo. PEP provides a novel, clinical-grade, off-the-shelf therapy to promote angiogenesis for the treatment of peripheral arterial disease.