Systematic Review on the Use of Radial Head Prosthesis in Fractures and Dislocations around the Elbow

Abstract

Radial head fractures are common injuries, comprising one third of all elbow fractures. Displaced fractures may occur in isolation but frequently are associated with dislocation of the elbow and damage to the medial and lateral collateral ligaments. Early reports of open reduction internal fixation (ORIF) of fractures of the radial head were very positive, perhaps because the technique was initially used for stable, minimally displaced, isolated partial head fractures for which good results would be expected even with non-operative treatment. It is found that unstable, displaced,multi-fragmented fractures of the radial head are subjected to early failure, nonunion, and poor forearm rotation after operative fixation. In cases of comminuted radial head fractures not amenable for fixation, excision is utilized; however, radial head excision causes altered elbow kinematics, increased laxity, and proximal migration of the radius causing wrist pain and weak hand grip. Replacement of the fractured radial head with prosthesis (RHP) helps to restore stability of the elbow and forearm. An improved understanding of the elbow complex biomechanics and the role played by the radial head in physiological elbow function has led to substantial improvements in the design of radial head implants, as well as the material used. The aim of this work is to highlight the results of radial head prosthesis application, functional outcomes and post-RHPcomplication in fractures and dislocations around the elbow through a systematic article review of English literature. The electronic comprehensive literature search identified 17 studies accounting for a total of 748 radial head implants that were included in the final analyses. The most commonly reported indication for acute RHP was complex radial head fractures (Mason Type 3 and 4) along with concomitant elbow injuries that threatened the stability of the elbow joint. Residual pain and stiffness from previous failed resection or internal fixation was found to be the indication for delayed arthroplasty. Less common indications included traumatic elbow instability, previously failed excision or fixation, failed silicone replacement. The contraindications that are described in the literature include open fractures with risk of infection, chondral lesion or avascular necrosis of capitellum and known allergy to metal used in the implant. The most common mechanism of injury reported was a fall on outstretched hand, followed by a fall from a height, and motor vehicle accident. Radial head arthroplastyconsistently leads to improved functional outcomes (ROM, elbow strength, stability of elbow joint, residual pain and patient satisfaction) as evident from the reviewed literature. To effectively evaluate the mid- to long-term outcomes of radial head arthroplasty, future clinical trials should be designed to prospectively compare implant designs and operative techniques with validated outcomes.