Duke Whan Chung

Effect of Hyaluronic Acid-Carboxymethylcellulose Solution on Perineural Scar Formation after Sciatic Nerve Repair in Rats

Background Scar tissue formation is the major cause of failure in peripheral nerve surgery. Use of a hyaluronic acid-carboxymethylcellulose (HA-CMC) membrane (Seprafilm) as a solid anti-adhesion barrier agent is one of the therapeutic approaches to reduce postoperative scar tissue formation. However, a solid membrane may not be suitable for repair of a weak peripheral nerve site. This study examined the effect of HA-CMC solution on perineural scar formation after peripheral nerve repair in rats. Methods The sciatic nerves of 40 rats were transected and then immediately repaired using 10-0 nylon. The nerves were divided randomly into two groups. Saline and HA-CMC solution were applied topically to the nerve repair sites in the control and experimental groups, respectively. Reoperation was performed at 3, 6, 9, and 12 weeks to assess scar tissue formation. The assessment included the quality of wound healing, presence of perinueral adhesion, cellular components of the scar tissue, thickness of the scar tissue and histomorphological organization of the repair site. Results Topical application of the HA-CMC solution significantly decreased the macroscopic nerve adherence score and the numbers of the cellular components such as fibroblasts and inflammatory cells (p < 0.05, Mann-Whitney U-test). The scar tissue formation index was significantly lower in the experimental group at 12 weeks than that in the control group (p < 0.05, Mann-Whitney U-test). The grading scores of the histomorphological axonal organization at the repair site were significantly higher in the experimental group than those in the control group at 12 weeks (p < 0.05, Mann-Whitney U-test). No evidence of wound dehiscence or inflammatory reactions against the HA-CMC solution was noted. Conclusions Topical application of a HA-CMC solution is effective in reducing the perineural scar formation and adhesion after sciatic nerve repair in rats, and is effective in promoting peripheral nerve regeneration at the repair site.

Factors Causing Prolonged Postoperative Symptoms Despite Absence of Complications After A1 Pulley Release for Trigger Finger

PURPOSE This study aimed to investigate the incidence and prognostic factors for prolonged postoperative symptoms after open A1 pulley release in patients with trigger finger, despite absence of any complications. METHODS We reviewed 109 patients (78 single-finger involvement, 31 multiple-finger involvement) who underwent open A1 pulley release for trigger finger from 2010 to 2016, with 8 weeks or longer postsurgical follow-up and without postoperative complications. The group had 16 men and 93 women, with mean age of 56 years (range, 21-81 years), and average follow-up period of 24.8 weeks (range, 8.0-127.4 weeks). Prolonged postoperative symptoms were defined as symptoms persisting for longer than 8 weeks after surgery. Factors analyzed for delay in recovery included duration of preoperative symptoms; number of preoperative local corticosteroid injections; preoperative flexion contracture of proximal interphalangeal (PIP) joint; multiplicity of trigger finger lesions; occupation; presence of type 2 diabetes mellitus, other hand disorders like carpal tunnel syndrome, de Quervain disease, or Dupuytren contracture; and fraying or partial tear of the flexor tendon. RESULTS Twenty-six fingers (19.3%) showed prolonged postoperative symptoms, with mean time until complete relief being 14.0 ± 6.4 weeks (range, 9-34 weeks). Risk factors associated with prolonged postoperative symptoms included duration of preoperative symptoms, preoperative flexion contracture of the PIP joint, and fraying or partial tear of the flexor tendon. CONCLUSIONS Physicians should consider the duration of preoperative symptoms and preoperative flexion contracture of the PIP joint when deciding timing of surgery for trigger finger patients. In addition, they should explain to patients with a positive history of these factors and in whom flexor tendon injury is found during surgery about the possibility of prolonged postoperative symptoms. TYPE OF STUDY/LEVEL OF EVIDENCE Prognostic IV.

Morphological Study of the Proximal Fibular Articular Surface Using Computed Tomography: Which Side Is Preferred for Proximal Fibular Flap in Wrist Arthroplasty?

Background Although proximal fibular flaps have been widely applied in wrist arthroplasty, controversy remains regarding which side of the proximal fibula is better for reconstruction of the distal radius. If the articular surface of the proximal fibula shows dorsal tilting, the ipsilateral (right) proximal fibula should be harvested in right wrist arthroplasty because the articular surface of the distal radius normally has volar tilt. This study investigated anatomical similarities between the proximal fibular articular surface and the distal radius articular surface based on morphologic analysis of the proximal fibula using computed tomography (CT). Methods A total of 18 proximal fibulae from 18 adult volunteers were analyzed using CT. Tilt and length of the proximal fibular articular surface were measured in the section plane parallel to the proximal tibiofibular articular surface (simulated sagittal plane). The inclination angle of the articular surface was measured in the section plane perpendicular to the proximal tibiofibular articular surface (simulated coronal plane). Results In the simulated sagittal plane, the articular surface of the proximal fibula showed a mean dorsal tilt of 4.1 degrees; the articular surface for each scan was 17.1 mm. In the simulated coronal plane, two articular surfaces were studied. The inclination angle of these surfaces was measured as 32.2 and 54.4 degrees, respectively. Conclusion CT analysis of the proximal fibular articular surfaces suggested that ipsilateral proximal fibular transfer can result in improved anatomic restoration of normal volar tilt of the distal radius due to dorsal tilt of the proximal fibular articular surface.