The classification, diagnosis and treatment of rare avulsion injury of flexor digitorum profundus tendon

Abstract

Objective To report the clinical experience of diagnosing and treating uncommon avulsion injury of the flexor digitorum profundus (FDP) tendon and propose a new type of injury classification. Methods A retrospective chart review was conducted of 17 cases of avulsion injury of the flexor digitorum profundus tendon treated between January 1995 and May 2015. Three were 7 cases of typeⅠ, 2 cases of type Ⅱ and 5 cases of type Ⅲ injuries. Three cases did not fall in any of the four types of Leddy and Smith Classification. All the cases were surgically treated. Results All 17 patients were follow-up for 3 to 18 months postoperatively. There was some extent of flexion of the distal interphalangeal joint. The treatment results were evaluated by measuring total active range of motion of the injured finger (TAM) and rated as excellent in 11 cases, good in 3 cases, fair in 1 case and poor in 2 cases. Conclusion Early diagnosis and surgical repair of avulsed flexor digitorum profundus tendon can achieve good clinical outcomes. For the 3 cases that cannot be categorized by Leddy and Smith Classification, the rupture is in two places: one being FDP insertion, the other being lumbrical muscle attachment on FDP. We propose to name this type of injuryⅠsubtype since it is similar to Leddy-Smith typeⅠ injury. Key words: Tendon injuries; Transplantation; Classification