[Recent fractures of the radial head associated with elbow instability treated with floating Judet prosthesis].

PURPOSE OF THE STUDY: Fracture of the radial head associated with elbow instability is infrequent. We report a retrospective series of floating Judet prostheses implanted for comminutive fractures of the radial head associated with elbow laxity caused either by dislocation or rupture of the medial collateral ligaments.

MATERIAL AND METHODS: The series included ten patients who underwent surgery from October 1996 to September 2002 at the Amiens University Hospital. The indication for radial head prosthesis was established in the emergency setting for fracture unamendable by osteosyntheis and elbow laxity. Mean age was 48.2 years (25-69). All patients were seen at mean follow-up of 31.7 months (18-48). According to the Mason classification as modified by Johnson, all patients had type 4 fracture. A Judet radial head prosthesis with a floating metallic cup was implanted in all patients. An investigator other than the operators evaluated outcome using the Mayo Clinic criteria.

RESULTS: Joint motion as measured by goniometry was: mean flexion 121degrees (90-140 degrees), mean extension deficit 20 degrees (5-60 degrees), mean pronation 45 degrees (0-85 degrees), mean supination 42.5 degrees (0-90 degrees). The Mayo clinic score was excellent in 3, good in 2, fair in 3, and poor in 2 (prosthesis dislocation in one and hung prosthesis requiring removal in one). Four patients developed periarticular ossifications compromising the final result.

DISCUSSION: The floating Judet prosthesis allows optimal adaptation of the implant to anatomy and function. For us, these implants are indispensable when the radial head fracture is associated with elbow instability. The indication for prosthesis may be questionable if the non-fixed fracture is free of associated ligament injury, as suggested by the good long-term reported after simple resection. Rigorous operative technique is crucial, with careful restitution of the radial height. The quality of the result is related to the degree of capsule and ligament injury even after optimal implant positioning. Preventive treatment against periarticular ossification should be systematic.