Brian T. Carlsen

Comparison of single versus double nerve transfers for elbow flexion after brachial plexus injury

Background: Restoration of elbow flexion is commonly achieved with nerve transfer to the musculocutaneous nerve branches after upper trunk brachial plexus injury. It is unknown if double nerve transfer to the biceps and brachialis nerve branches results in greater strength than single nerve transfer to the biceps branch alone. Methods: A retrospective review was performed of all patients receiving nerve transfer to restore elbow flexion. Single and double nerve transfers were compared in regard to severity of injury, elbow flexion, supination, grip strengths, and Disabilities of the Arm, Shoulder, and Hand scores. Elbow flexion and supination torque strength were measured quantitatively. Results: Fifty-five patients underwent nerve transfer to restore elbow flexion (23 single, 32 double). At similar follow-up periods, British Medical Research Council grade improved to 4 or better in 14 of 21 single and 24 of 30 double nerve transfer patients. Supination strength was similar between groups (p = 0.148). Grip strength was greater in the double nerve transfer patients (p = 0.028). Preoperative Disabilities of the Arm, Shoulder, and Hand scores were significantly greater in single versus double nerve transfer patients (p = 0.018). Although single nerve transfer patients had a greater improvement in scores, the final mean scores were similar in the two groups. The severity of injury was different between the two groups, with 19 of 23 single nerve transfer patients having injury beyond the C5–6 level and only 16 of 32 of double nerve transfer patients with greater than C5–6 injury (p = 0.020). Conclusions: Outcomes are similar between the two groups for elbow flexion and supination strength. Postoperative Disabilities of the Arm, Shoulder, and Hand scores are similar in single and double nerve transfer patients.

Bone morphogenetic protein-2 (BMP-2) and transforming growth factor-β1 (TGF-β1) alter connexin 43 phosphorylation in MC3T3-E1 Cells

BackgroundBone morphogenetic proteins (BMPs) and transforming growth factor-βs (TGF-βs) are important regulators of bone repair and regeneration. BMP-2 and TGF-β1 have been shown to inhibit gap junctional intercellular communication (GJIC) in MC3T3-E1 cells. Connexin 43 (Cx43) has been shown to mediate GJIC in osteoblasts and it is the predominant gap junctional protein expressed in these murine osteoblast-like cells. We examined the expression, phosphorylation, and subcellular localization of Cx43 after treatment with BMP-2 or TGF-β1 to investigate a possible mechanism for the inhibition of GJIC.ResultsNorthern blot analysis revealed no detectable change in the expression of Cx43 mRNA. Western blot analysis demonstrated no significant change in the expression of total Cx43 protein. However, significantly higher ratios of unphosphorylated vs. phosphorylated forms of Cx43 were detected after BMP-2 or TGF-β1 treatment. Immunofluorescence and cell protein fractionation revealed no detectable change in the localization of Cx43 between the cytosol and plasma membrane.ConclusionsBMP-2 and TGF-β1 do not alter expression of Cx43 at the mRNA or protein level. BMP-2 and TGF-β1 may inhibit GJIC by decreasing the phosphorylated form of Cx43 in MC3T3-E1 cells.

Osteoarthritis of the wrist.

Summary: This article reviews pathogenesis and treatment of wrist osteoarthritis. Because there is no cure for osteoarthritis, treatment is directed at symptomatic relief. Surgical treatment is reserved for patients who have failed nonoperative modalities. This article reviews the surgical treatment of wrist osteoarthritis with an emphasis on selection of the appropriate procedure. Literature guiding surgical treatment with patient outcomes is reviewed.

Desmoid tumor following abdominally-based free flap breast reconstruction

Desmoid tumors are fibroblastic connective tissue tumors that most commonly develop within the anterior abdominal wall. The etiology of desmoid tumors has not been well defined; however, hereditary, hormonal, traumatic, and surgery-related causes have been implicated. Desmoid tumors are believed to arise from musculoaponeurotic structures. Development in the breast is very rare. Several reports of desmoid tumors arising in the vicinity of the fibrous capsule of a breast implant have been described, but to date, the authors are not aware of any published cases following autologous breast reconstruction. This report describes a desmoid tumor developing after a muscle-sparing free transverse rectus abdominis musculocutaneous (TRAM) flap for breast reconstruction and subsequent surgical management.