[Diagnosis and treatment of finger flexion contracture caused by forearm flexor disease].

Objective: To summarize the clinical characteristics, differential diagnosis, and treatment methods of finger flexion contracture caused by three kinds of forearm flexor diseases.

Methods: Between December 2008 and August 2021, 17 patients with finger flexion contracture were treated, including 8 males and 9 females, aged 5-42 years, with a median of 16 years. The disease duration ranged from 1.5 months to 30 years, with a median of 13 years. The etiology included 6 cases of Volkmann's contracture, all of which were flexion deformity of the 2nd to 5th fingers, accompanied by limitation of thumb dorsiflexion in 3 cases and limitation of wrist dorsiflexion in 3 cases; 3 cases of pseudo-Volkmann's contracture, including 2 cases of flexion deformity of middle, ring, and little fingers, and 1 case of flexion deformity of ring and little fingers; 8 cases of ulnar finger flexion contracture caused by forearm flexor disease or anatomical variations, all of which were flexion deformity of middle, ring, and little fingers. Operations such as slide of flexor and pronator teres origin, excision of abnormal fibrous cord and bony prominence, and release of entrapped muscle (tendon) were performed. Hand function was evaluated according to WANG Haihua's hand function rating standard or modified Buck-Gramcko classification standard, and muscle strength was evaluated according to British Medical Research Council (MRC) muscle strength rating standard.

Results: All patients were followed up 1-10 years (median, 1.5 years). At last follow-up, 8 patients with contracture caused by forearm flexor disease or anatomical variations and 3 patients with pseudo-Volkmann's contracture achieved excellent hand function, with muscle strength of grade M5 in 6 cases and grade M4 in 5 cases. One patient with mild Volkmann's contracture and 3 patients with moderate Volkmann's contracture without severe nerve damage had excellent hand function in 2 cases and good in 2 cases, with muscle strength of grade M5 in 1 case and grade M4 in 3 cases. Two patients with moderate or severe Volkmann's contracture had poor hand function, with 1 case of muscle strength of grade M3 and 1 case of grade M2, which improved when compared with those before operation. The overall excellent and good rate of hand function and the proportion of patients with muscle strength of grade M4 and above were 88.2% (15/17), respectively.

Conclusion: The finger flexion contracture caused by different etiology can be differentiated by analyzing the history, physical examination, radiographs, and intraoperative findings. After different surgical treatments, such as resection of contracture band, release of compressed muscle (tendon), and downward movement of flexor origin, most patients have a good outcome.