315. FRACTURES OF THE FIFTH METACARPAL: OSTEOSYNTHESIS WITH A LOCKED SCREW PLAT OR CENTROMEDULLARY NAILING?

Abstract

Purpose of the study: Fractures of the metacarpals are common injuries generally observed in young males. Nailing, either with a centromedullary configuration or intermetacarpal construction is generally proposed. The nailing procedure nevertheless has its drawbacks: fracture instability, secondary displacement, pin migration, infection, requirement to remove material, injury to the cutaneous dorsal branch of the ulnar nerve, and most importantly, immobilisation for several weeks which is a major inconvenience for these young active patients. In this context, we wanted to compare two fixation systems: a locked plate versus centromedullary nailing.

Material and methods: This was a retrospective comparison of consecutive patients from September 2007 to December 2008. The series included 39 cervical fractures of the fifth metacarpal in 39 patients aged 31 years on average. The first 19 patients were treated with a locked plate (Médartis^®) (group A) and the 20 others with descending centromedullary nailing (group B). In group A, a dorsal approach respecting the dorsal cutaneous branch of the ulnar nerve was used. The technique consisted in insertion of distal locking screws enabling fracture reduction on the plate. No postoperative immobilisation was proposed and rapid mobilisation was encouraged. In group B, classical centromedullary nailing was performed with immobilisation with a short Thomine brace and syndactylisation of the last two fingers. Outcome was based on objective criteria (Jamar^® force, joint motion, duration of sick leave) and subjective assessment (DASH, VAS).

Results: Mean follow-up was 12 months in group A and 8 months in group B. Depending on the type of fracture, plates with different shapes and lengths were used in group A; a single pin was used in group B (16/10 or 20/10). Secondary displacement was more frequent in group B, but the results in recovered motion were better in group B. The only parameter better in group A was length of sick leave; four patients in group A underwent reoperation to remove the plate and for tenoarthrolysis. In all, the outcomes for cervical fractures of the fifth metatarsal were better in group B.

Discussion: Our preliminary results in group A show lesser complications and earlier return to work compared with better motion at last follow-up in group B. Centromedullary nailing remains the better treatment for cervical fractures of the fifth metatarsal. The extra cost of the plates does not appear to be warranted for the treatment of neck fractures of the fifth even though the patient can resume occupational activities earlier.