Radial head replacement with a pyrocarbon head prosthesis: Preliminary results of a multicentric prospective study

Abstract

The authors present the preliminary results of a multicentric prospective study of 30 cases treated by a new radial head prosthesis (MoPyc). This new modular radial head prosthesis is composed of a cementless titanium stem and a 15° angulated neck. The head is in pyrocarbon and enables an optimal couple of friction between the implant and cartilage. This multicentric prospective study includes 30 patients (19 men and 11 women, mean age 50 years). The mean follow-up was 18 months (6-29 months). The main etiology was a radial head fracture with elbow instability. The post-operative evaluation was clinical and included the Broberg-Morrey score and the Mayo Clinic Elbow Performance Score (MEPS). The radiological evaluation included the stability of the elbow, the fixation of the prosthesis and the interface between the pyrocarbon head and the humeral condyl and the distal radio-ulnar joint. At the time of follow-up, the average Broberg-Morrey score was 88/100, with 77% of good and excellent results. The average MEPS was 95/100, with 97% of good and excellent results. Elbow flexion averaged 122°, extension -15°, pronation 74° and supination 72°. Elbow stability was good in all the cases, and no proximal migration of the radius occurred. Asymptomatic bone lucencies were found in five cases (three stress shieldings, under the neck of the prosthesis, two around the stem). Complications included two cases of proximal radio-ulnar synostosis and one under stuffing of the prosthesis (which was re-operated shortly after the first implantation) with a good final result. One case demonstrated a tendency to posterior subluxation during heavy work. The preliminary results of 30 patients treated by this radial head prosthesis with a pyrocarbon head are encouraging at a follow-up of 18 months. The shape and the modularity of this prosthesis provide a good stability and function of the elbow and allow an easy implantation regardless of the level of resection. The contact between the articular surfaces and the pyrocarbon head should ensure the durability of this arthroplasty. However, a longer follow-up is required. © Springer-Verlag 2005.