Treatment of cubital tunnel syndrome with ulnar nerve anterior submuscular transposition and medial epicondyle muscle group in situ reconstruction via a bone tunnel

Abstract

Objective To investigate the clinical effectiveness of treating moderate to severe cubital tunnel syndrome with ulnar nerve decompression,anterior submuscular transposition and medial epicondyle muscle group in situ reconstruction via a bone tunnel.Methods The clinical data of 45 cases of moderate to severe cubital tunnel syndrome diagnosed between January 2005 and October 2012 were analyzed.The ulnar nerve was decompressed and its perfnsion by the superior ulnar collateral artery was observed under the surgical microscope intraoperatively.After ulnar nerve was transposed anteriorly,the detached medial epicondyle muscle group was reconstructed in situ through a bone tuunel under direct view.The size of the new ulnar nerve tunnel and mobility of the ulnar nerve were observed.Postoperative recovery was follow-up including pain,sensation,muscular atrophy recovery,claw hand,grip strength,wrist flexion and forearm pronation.Results All 45 cases were follow-up for 6 to 18 months.Intraoperative microscopic observation showed good ulnar nerve perfusion by the superior ulnar collateral artery.Reattachment of the medial epicondyle muscle group was secure.The newly formed cubital tunnel could allow an 8 mm dilator without tension in elbow full extension position.Ulnar nerve could glide freely upon elbow flexion and extension.According to the cubital tunnel syndrome function evaluation standard suggested by Gu Yudong,the results were graded as excellent in 20 cases,good in 17 cases,and fair in 8 cases.The overall excellent and good rate was 82.22％.Wrist flexion and forearm pronation force recovered to preoperative level in all the patients 3 months after the operation.Conclusion Including superior ulnar collateral artery in the anterior transposition of the ulnar nerve provides good blood supply to the nerve and benefits nerve recovery.In situ reconstruction of the medial epicondyle muscle group through a bone tunnel puts the ulnar nerve anderneath flexor carpi ulnaris and pronator teres.The new tunnel is big enough to avoid compression of the nerve.The surrounding tissues are loose so there will be neither ulnar nerve compression around the elbow nor nerve stretch upon elbow flexion.Muscle reattachment via a bone tunnel is secure.No postoperative elbow immobilization with a cast is needed.This allows early protected movement and early return to normal life and work. Key words: Cubital tunnel syndrome; Humerus; Anterior submuscular transposition; Bone tunnel; Reconstruction in situ