Prosthetic replacement of the radial head

Abstract

Abstract Background Radial head replacement is an established option in patients with comminuted radial head fractures and complex elbow trauma. While studies demonstrated that asymptomatic radiolucencies around the stem are common, the incidence and clinical significance of bone loss at the proximal part of the radius, just distal to the neck of the prosthesis (collar resorption), is unknown. Objectives The aim of this retrospective study was to analyse the incidence of collar resorption after radial head replacement and investigate whether this correlates with specific patient characteristics such as gender, age, indication for index surgery and the size of implant used. Materials and methods The study group consisted of 30 patients (average age 60.1 years) having undergone prosthetic replacement with a monopolar press-fit implant of the radial head at an average follow-up of 23 months. Indications for surgery included trauma sequelae or revision in 16 patients and acute, unreconstructable fractures of the radial head in 14 cases. Symptoms of loosening and revision surgery were recorded. Radiographs were analysed for signs of lucency between the bone and the implant as well as for signs of resorption of bone mass around the neck (section 1). These values were correlated with age, gender, indication for index surgery and size of implant. Results In all, 28/30 (93.3%) prostheses showed proximal osteolysis around the neck of the shaft. Of the 30, one prosthesis presented signs of shaft loosening. The average amount of osteolysis was 8.78% (range 0–26.1%; ±6.0%) of the overall length of the prosthetic shaft (OL). There was no significant difference (p = 0.49) between the amount of resorption in section 1 between the primary fracture cases (8.75 ± 4.5%; range 1.2–15.8%) and the group of secondary implantations due to degeneration or fracture sequelae (8.8 ± 7.2%; range 0–26.1%). Furthermore, the analysis did not reveal any statistically relevant correlations between the amount of neck resorption and the other cohort characteristics (age, gender, size of the components). Conclusions In the study cohort, a high amount of osteolysis/bone resorption was assessed around the neck of the press-fit radial head prosthesis used. However, no significant correlation between collar resorption, patient demographics and indication for index surgery was found at short-term follow-up.