Distal Ulnar Bifurcation Arthroplasty in the Treatment of Bayne and Klug Types 3 and 4 Radial Club Hands: Preliminary Outcomes.

BACKGROUND: The treatment of Bayne and Klug types 3 and 4 radial club hands (RCHs) remains challenging and controversial. In this study, the authors reported a new procedure called distal ulnar bifurcation arthroplasty and reviewed the preliminary results. METHODS: Between 2015 and 2019, 11 patients with 15 affected forearms having type 3 or 4 RCHs underwent distal ulnar bifurcation arthroplasty. The mean age was 55.5 months (range, 29 to 86 months). The surgical protocol consisted of (1) bifurcation of the distal ulna to accommodate the wrist with stable support; (2) pollicization to treat hypoplastic or absent thumb; and (3) in the case of significant bowed ulna, ulnar corrective osteotomy. In all patients, clinical and radiologic parameters including hand-forearm angle, hand-forearm position, ulnar length, wrist stability, and motion were recorded. RESULTS: The mean duration of follow-up was 42.2 months (range, 24 to 60 months). The average correction of hand-forearm angle was 80.2 degrees. The overall range of active wrist motion was approximately 87.5 degrees. Ulna growth per year was 6.7 mm (range, 5.2 to 9.2 mm). No major complications were recorded during follow-up. CONCLUSIONS: The distal ulnar bifurcation arthroplasty offers a technically feasible alternative for the treatment of type 3 or 4 RCH, which enables satisfactory appearance, provides stable support to the wrist, and maintains wrist function. Despite the promising preliminary results, longer follow-up is necessary to evaluate this procedure. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Docosahexaenoic Acid Improves Diabetic Wound Healing in a Rat Model by Restoring Impaired Plasticity of Macrophage Progenitor Cells.

BACKGROUND: Chronic inflammation associated with delayed diabetic wound healing is induced by disturbed polarization of macrophages derived mainly from predisposed progenitor cells in bone marrow. Docosahexaenoic acid plays a critical role in regulating the function of macrophage progenitor cells. The authors evaluated whether docosahexaenoic acid accelerates diabetic wound healing in rats. METHODS: Streptozotocin-induced diabetic rats divided into control and docosahexaenoic acid-treated groups (n = 10) were subjected to paired dorsal skin wounds. Docosahexaenoic acid (100 mg/kg per day) was orally supplemented 2 weeks before wounding until termination. The wound healing process was recorded 0, 7, and 14 days after wounding. At day 7, blood perfusion was measured by laser Doppler perfusion imaging; angiogenesis was compared using immunofluorescent CD31 and α-smooth muscle actin staining; macrophage polarization was detected using immunofluorescence for CD68, CD206, and inducible nitric oxide synthase. Hematoxylin and eosin staining was used to examine wound healing at day 14. Activation status of macrophages derived from bone marrow cells in normal, diabetic, and docosahexaenoic acid-treated diabetic rats was determined in vitro using Western blotting and enzyme-linked immunosorbent assay. RESULTS: Docosahexaenoic acid significantly accelerated wound healing 7 and 14 days (p < 0.01) after wounding. Increased vessel densities (1.96-fold; p < 0.001) and blood perfusion (2.56-fold; p < 0.001) were observed in docosahexaenoic acid-treated wounds. Immunofluorescence revealed more CD206 and fewer inducible nitric oxide synthase-positive macrophages (p < 0.001) in treated wounds. Furthermore, macrophages derived from diabetic rats expressed higher levels of inducible nitric oxide synthase and tumor necrosis factor-α and lower arginase-1 and interleukin-10 (p < 0.05). CONCLUSION: Docosahexaenoic acid accelerates diabetic wound healing at least in part by restoring impaired plasticity of macrophage progenitor cells.

A novel duplication downstream of BMP2 in a Chinese family with Brachydactyly type A2 (BDA2).

BACKGROUND: Brachydactyly type A2 (BDA2) is an autosomal dominant disease characterized by the deformation of the middle phalanx of the second fingers and toes. It has been reported to be associated with three genes regulating the osteogenesis, including BMPR1B, GDF5 and BMP2. MATERIALS AND METHODS: 10 BDA2 patients and 7 unaffected individuals in a Chinese family were identified through clinical signs and radiographs. The mutation analyses of BMPR1B, GDF5 and BMP2 gene was performed in all the available family members and 100 control subjects. The duplication analysis for the downstream of BMP2 was also performed in all the samples. RESULTS: A novel 4671bp duplication downstream the BMP2 gene was identified in all the patients undergoing molecular analysis but not in the unaffected individuals and healthy controls, with a 28bp microhomology flanking it. There was no mutation in all the exons of BMPR1B, GDF5 and BMP2 in all the tested family members. CONCLUSION: The novel duplication has different breakpoints compared with the previous ones but highly overlapped with them. The duplication narrows the range of the potential cis-regulatory sequence, and further supports the association between BDA2 and the duplication downstream BMP2.

The Effect of Atorvastatin on the Viability of Ischemic Skin Flaps in Diabetic Rats.

BACKGROUND: Endothelial progenitor cells play a critical role in neovascularization. However, the mobilization, recruitment, and functional capacity of endothelial progenitor cells are significantly impaired in diabetes. Statins have been shown to augment the number and improve the function of endothelial progenitor cells. This study investigated the effects of statins on the viability of ischemic skin flaps in diabetic rats. METHODS: Twenty normal and 40 diabetic Sprague-Dawley rats were included in this study. Atorvastatin (10 mg/kg/day) was administered orally in 20 diabetic rats at 2 weeks before flap surgery for 21 consecutive days. Other rats received equal vehicle. Two weeks after first gavage, a 3 × 10-cm skin flap was established on the backs of rats. The necrotic area of each skin flap was measured at 7 days postoperatively. Capillary density and endothelial progenitor cells recruited to the flaps were analyzed using immunofluorescence staining. Circulating endothelial progenitor cell number was determined by flow cytometry. In vitro migration and tube formation experiments were used to analyze the function of endothelial progenitor cells. RESULTS: Atorvastatin treatment increased flap survival rate and capillary density. In addition, more endothelial progenitor cells were identified in peripheral blood and skin flaps in diabetic rats receiving atorvastatin. Atorvastatin treatment also restored the impaired function of diabetic endothelial progenitor cells in migration and tube formation. CONCLUSION: Atorvastatin notably promoted neovascularization and enhanced the viability of ischemic skin flaps in diabetic rats, which may be mediated at least partially by augmenting the number and restoring the functional capacity of endothelial progenitor cells.

Stimulation of Nitric Oxide Production Contributes to the Antithrombotic Effect of Stromal Cell-Derived Factor-1α in Preventing Microsurgical Anastomotic Thrombosis.

Background Intimal injury plays a critical role in initiating the pathogenesis of thrombosis formation after microsurgical anastomosis. Application of stromal cell-derived factor-1α (SDF-1α) is reported to promote early regeneration of injured intima through migration of endothelial cells and mobilization of endothelial progenitor cells. We therefore hypothesized that local transfer of SDF-1α gene would inhibit microsurgical anastomotic thrombosis. Methods Sixty Sprague-Dawley rats were used and divided randomly into three groups (SDF-1α group, plasmid group, and saline group) in this study. Plasmid DNA encoding SDF-1α, empty plasmid, and saline were injected into the left femoral muscles of rats from each group, respectively. Seven days after injection, peripheral blood samples were obtained to measure the plasma levels of SDF-1α and nitric oxide (NO). The left femoral artery of each rat was crushed, transected, and repaired by end-to-end microsurgical anastomosis. Vascular patency was assessed at 15, 30, and 120 minutes after reperfusion using milk test. Thrombosis formation was assessed with hematoxylin and eosin staining and scanning electron microscopy at 120 minutes postoperatively. Results The plasma levels of SDF-1α and NO in SDF-1α group were significantly higher than those in plasmid group and saline group (p < 0.01). The patency rate in SDF-1α group was significantly higher than that in control groups at 120 minutes after reperfusion (p < 0.05). Treatment of SDF-1α significantly reduced the size of thrombotic occlusion when compared with controls (p < 0.05). All SDF-1α recipients exhibited decreased thrombosis under scanning electron microscopy. Conclusions The current study demonstrated that local transfer of SDF-1α gene increases arterial patency and inhibits microsurgical anastomotic thrombosis in a crush model of femoral artery in rat. The antithrombotic effect of SDF-1α may be mediated through increased production of endogenous NO. These findings provide a novel approach for inhibition of microsurgical anastomotic thrombosis.

Combined Anterolateral Thigh and Anteromedial Thigh Flap for Extensive Extremity Reconstruction: Vascular Anatomy and Clinical Application.

BACKGROUND: The combined anterolateral thigh (ALT) and anteromedial thigh (AMT) flap has been previously reported for use in complicated head and neck reconstruction. However, it has not gained popularity due to the vascular variation. Here, we explore the vascular basis of this combined flap, and report its application in extremity reconstruction. METHODS: This study was divided into two parts: vascular anatomy and clinical application. In the anatomical study, 52 sides of adult thighs were dissected to identity vascular perforators supplying the combined ALT and AMT flap, with focus on sizeable perforators (larger than 0.5 mm) arising from the descending branch of the lateral circumflex femoral artery.Clinically, five male patients were treated by combined ALT and AMT flaps for extensive extremity reconstruction from January 2006 to December 2010. The mean age was 32 years (range, 23-45 years). The combined flap was used for covering large soft-tissue defects in forearm (n = 3) and calf (n = 2). For each patient, esthetic and functional results were recorded. RESULTS: The anatomical study showed that sizeable perforators supplying the ALT flap were present in 50 thighs (96.2%), and the perforators supplying the AMT flap were present in 32 thighs (61.5%). The combined ALT and AMT flaps were available in 30 thighs (57.7%).All five combined flaps survived completely. Skin grafts covering the donor sites healed uneventful. The mean follow-up was 9.6 months (range, 6-12 months). No complications were recorded during the follow-up. CONCLUSION: The combined ALT and AMT flap may be used for extensive extremity reconstruction in selected patients for its great maneuverability and acceptable donor-site morbidity.

Management of hypertrophic nonunion with failure of internal fixation by distraction osteogenesis.

INTRODUCTION AND AIM: Distraction osteogenesis is employed in the management of hypertrophic nonunion associated with angular deformity and shortening. This study was aimed at evaluating the outcomes of Ilizarov apparatus without bone graft or open osteotomy in cases of hypertrophic nonunion not responding to treatment with internal fixation. METHODS: We retrospectively reviewed the data of 12 patients (mean age, 46.5 years) treated for hypertrophic nonunion at our institution. All patients had two-plane angular deformities (mean, 19° and 23.5° in sagittal and frontal plane, respectively) and limb-length discrepancy (mean, 3.8cm). The Ilizarov apparatus was used to simultaneously treat the nonunion, malalignment, and limb-length discrepancy. RESULTS: The mean follow-up duration after the removal of the apparatus was 42 months. In all cases, bone union had been achieved within an average of 8 months after a single surgery, without the need for any additional procedure. Additionally, none of the patients had recurrence of limb-length discrepancy or malalignment during the follow-up period. Complications of superficial pin-tract infections and mild Achilles tendon contracture were observed, but they resolved over time. All patients were satisfied with the outcome of the surgery. CONCLUSION: Patients with hypertrophic nonunion associated with internal fixation failure can be treated by using the Ilizarov apparatus, thereby eliminating the need for bone graft or open osteotomy. Distraction osteogenesis appears to be effective as a minimally invasive percutaneous procedure in the treatment of hypertrophic nonunion with deformity and shortening.