Lui, Hayman

Background: To report the clinical outcomes of partial denervation for the treatment of basilar thumb joint arthritis. Methods: Patients who underwent partial denervation of the basilar thumb joint for osteoarthritis from a single center between 2019 and 2021 were recruited into the study. This involved a technique that involved cauterization of the joint capsule and its innervation through the branches of the superficial radial, palmar cutaneous branch of the median, lateral antebrachial, and ulnar nerves. Patients were followed up postoperatively to record clinical (grip strength, thumb apposition and opposition pinch grip strength, Kapandji score) and patient-reported outcomes (visual analogue scale [VAS], Quick Disabilities of the Arm, Shoulder and Hand [QuickDASH], Patient-reported Wrist Evaluation [PRWE]). Results: Twelve patients (15 carpometacarpal joints; 9 female and 3 male patients) underwent a partial denervation of the thumb (Eaton stage 3-4). The mean age at the time of surgery was 63 ± 5 years (range 56-72). The mean clinical follow-up duration was 23 ± 11 months (range 9-42 months), and functional score follow-up duration was 27 ± 7 months (range 14-42 months). At the latest clinical follow, VAS score, Kapandji score, grip strength, and thumb apposition/opposition pinch strength all improved significantly ( P < .05). The mean QuickDASH score was 30 ± 16, and PRWE score was 32 ± 17. Patients who had unilateral partial thumb denervation demonstrated greater improvement in grip strength than patients who had bilateral partial thumb denervation procedures ( P = .01). Conclusion: In this clinical case series, our method of basilar thumb joint partial denervation has been effective in improving clinical outcomes and reducing pain due to osteoarthritis. Level of Evidence: IV, case series

Abstract Background Chronic injuries to the scapholunate ligament (SLIL) alter carpal kinematics and may progress to early degenerative osteoarthritis. To date, there is no consensus for the best method for SLIL reconstruction. This study aims to assess the use of growth factors (bone morphogenetic protein [BMP]2 and growth and differentiation factor 5 [GDF5]) for compartmentalized regeneration of bone and ligament in this multiphasic scaffold in a rabbit knee model. Case Description A total of 100 µg of BMP2 and 30 µg of GDF5 were encapsulated into a heparinized gelatin–hyaluronic acid hydrogel and loaded into the appropriate compartment of the multiphasic scaffold. The multiphasic scaffold was implanted to replace the native rabbit medial collateral ligament (n = 16). The rabbits were randomly assigned to two different treatment groups. The first group was immobilized postoperatively with the knee pinned in flexion with K-wires for 4 weeks (n = 8) prior to sacrifice. The second group was immobilized for 4 weeks, had the K-wires removed followed by a further 4 weeks of mobilization prior to sample harvesting. Literature Review Heterotopic ossification as early as 4 weeks was noted on gross dissection and confirmed by microcomputed tomography and histological staining. This analysis revealed formation of a bony bridge located within and over the ligament compartment in the intra-articular region. Biomechanical testing showed increased ultimate force of the ligament compartment at 4 weeks postimplantation consistent with the presence of bone formation and higher numbers of scaffold failures at the bone–tendon junction. This study has demonstrated that the addition of BMP2 and GDF5 in the bone–ligament–bone (BLB) scaffold resulted in heterotopic bone formation and failure of the ligament compartment. Clinical Relevance The implantation of a three-dimensional-printed BLB scaffold alone demonstrated superior biomechanical and histological results, and further investigation is needed as a possible clinical reconstruction for the SLIL.

Abstract Purpose We have previously described arthroscopic-assisted volar scapholunate (SL) capsulodesis as an alternative technique for addressing volar SL interosseous ligament (SLIL) injuries. In this article, we report the outcomes of this procedure in a cohort of patients. Methods Postoperative outcomes including range of motion, grip strength, visual analog scale (VAS) pain score, Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH), and Mayo Wrist Score were assessed through a prospective review of six patients in a single center who underwent this procedure. Results Six patients (four male and two female) with a mean age of 43 ± 14 years were evaluated in the study. The mean duration of follow-up was 41 ± 17 weeks. Postoperative outcomes noted a reduction in VAS pain score from 8 before surgery to 0.7 postoperatively (p = 0.00004) and improvement in Mayo Wrist Score (42 preoperatively to 80 postoperatively; p = 0.001), grip strength (86% of contralateral side; p = 0.20), and flexion arc (81% of contralateral side; p = 0.08). QuickDASH was 20 ± 8 and Patient-Rated Wrist Evaluation score was 13 ± 2 at the last clinical follow-up. There was an improvement in SL gap (p = 0.03), SL angle (p = 0.11), and radiolunate angle (p = 0.15) measurements postoperatively. Conclusions The described arthroscopic-assisted volar SL capsulodesis in this study presents an alternative method to address volar SLIL pathology with positive short-term clinical outcomes. Clinical Relevance Arthroscopic-assisted volar SL capsulodesis may be considered in the treatment algorithm for volar SLIL injuries.

Abstract Background Spanning bridge plates were first popularized for fixation of complex distal radius fractures. However, indications for their use have expanded including the surgical treatment algorithm for treating conditions such as Kienböck's disease. Traditionally, initial surgical treatment of Lichtman Stages II to III Kienböck's disease included lunate decompression, unloading, and revascularization procedures. The addition of a dorsal spanning bridge plate further facilitates lunate offloading and may improve bone revascularization. Case Description We report a complication of proximal carpal row dorsal subluxation secondary to dorsal spanning plate fixation in a patient with Stage IIIb Kienböck's disease. The patient had undergone wrist arthroscopy, lunate forage, radius core decompression, and spanning plate fixation. At 6 weeks after surgery, radiographic imaging demonstrated dorsal subluxation of the proximal carpal row that was corrected upon bridge plate removal. Serial radiographs during follow-up showed no further carpal subluxation without Kienböck's disease progression at 12 months postremoval of hardware. Patient remains pain free and has returned to elite level sport. Literature Review To our knowledge no previous cases of proximal carpal row subluxation with the use of dorsal bridge plate has been reported in the literature. Clinical Relevance Proximal row carpal subluxation can occur with dorsal bridge plate fixation.

High concentrations of bone morphogenetic protein 2 (BMP2) in bone regeneration cause adverse events (e.g, heterotopic bone formation and acute inflammation). This study examines novel epigenetic strategies (i.e., EZH2 inhibition) for augmenting osteogenesis, thereby aiming to reduce the required BMP2 dose in vivo for bone regeneration and minimize these adverse effects. Human bone marrow-derived mesenchymal stem cells (BMSCs) were grown on three-dimensional (3D)-printed medical-grade polycaprolactone scaffolds and incubated in osteogenic media containing 50 ng/mL BMP2 and/or 5 μM GSK126 (EZH2 inhibitor) for 6 days ( n = 3 per group and timepoint). Constructs were harvested for realtime quantitative polymerase chain reaction analysis at Day 10 and immunofluorescence (IF) microscopy at Day 21. After pretreating for 6 days and maintaining in osteogenic media for 4 days, BMSC-seeded scaffolds were also implanted in an immunocompromised subcutaneous murine model ( n = 39; 3/group/donor and 3 control scaffolds) for histological analysis at 8 weeks. Pretreatment of BMSCs with BMP2 and BMP2/GSK126 costimulated expression of osteoblast-related genes (e.g., IBSP , SP7 , RUNX2 , and DLX5 ), as well as protein accumulation (e.g., collagen type 1/ COL1A1 and osteocalcin/ BGLAP ) based on IF staining. While in vivo implantation for 8 weeks did not result in bone formation, increased angiogenesis was observed in BMP2 and BMP2/GSK126 groups. This study finds that BMP2 and GSK126 costimulate osteogenic differentiation of MSCs on 3D scaffolds in vitro and may contribute to enhanced vascularization when implanted in vivo to support bone formation. Thus, epigenetic priming with EZH2 inhibitors may have translational potential in bone healing by permitting a reduction of BMP2 dosing in vivo to mitigate its side effects. Impact statement While autografts are still the gold standard for bone reconstruction, tissue availability and donor morbidity are significant limitations. Previous attempts to use high concentrations of bone morphogenetic protein 2 (BMP2) have been shown to cause adverse events such as excessive bone formation and acute inflammation. Overall, the utilization of EZH2 inhibitors to modulate gene expression in favor of bone healing has been demonstrated in vitro in a tissue engineering strategy. Our study will pave the way to developing tissue engineering strategies involving GSK126 as an adjuvant to increase the effects of BMP2 for stimulating cells of interest on a three-dimensional scaffold for bone regeneration.

AbstractScapholunate interosseous ligament tears are a common wrist injury in young and active patients that can lead to suboptimal outcomes after repair. This research aims to assess a multiphasic scaffold using 3D‐printing for reconstruction of the dorsal scapholunate interosseous ligament. The scaffold was surgically implanted in vivo in the position of the native rabbit medial collateral ligament. Two branches of treatment were implemented in the study. In the first group, the rabbits (n = 8) had the knee joint fixed in flexion for 4 weeks using 1.4 mm K‐wires prior to sample harvesting. The second group (n = 8) had the rabbit knee joint immobilized for 4 weeks prior to K‐wire removal and mobilization for an additional 4 weeks prior to sample harvesting. Overall, samples were harvested at 4 weeks post‐surgery (immobilized group) and eight weeks post‐surgery (mobilized group). Mechanical tensile testing (n = 5/group) and histology (n = 3/group) of the constructs were conducted. Tissue integration and maturation were observed resulting in increased mechanical strength of the operated joint at 8 weeks (P < .05). Bone and ligament tissues were regenerated in their respective compartments with structural and mechanical properties approaching those reported for the human dorsal SLIL ligament. Clinical Significance: This proof of concept study has demonstrated that the synthetic multiphasic scaffold was capable of regenerating both bone and ligament while also withstanding the physiological load once implanted in the rabbit knee. The artificial scaffold may provide an alternative to current techniques for reconstruction of scapholunate instability or other ligament injuries in the hand and wrist.