Purpose. To analyse the early results of unconstrained pyrocarbon joint replacements in patients with osteo-arthritis of the metacarpo-phalangeal joints. Background. Silicone arthroplasty, as introduced by Swanson in 1962 has remained the most popular procedure to treat arthritis of the metacarpo-phalangeal (MCP) joints. However, despite providing good pain relief, they have shown to demonstrate breakage rates up to 82% at 5 years. This is of great concern in the osteoarthritis (OA) patient group, who tend to be younger and have higher functional demands compared to their rheumatoid counterparts. The newer unconstrained pyrolytic carbon MCP joint prostheses may therefore be more suitable in OA patients whose soft tissue constraints are intact and whose hand function is strong. This study is the first to analyse the results of this implant in a cohort of OA patients only, with prospective data. Methods. 19 primary pyrocarbon metacarpo-phalangeal joint replacements, in 11 patients (5 men and 6 women) were reviewed, with prospective data collection. The diagnosis was primary osteoarthritis in all patients. The mean age at operation was 66.4 years (range 55–82 years). 2 patients underwent concomitant trapiezectomy and one underwent DIPJ fusion. All patients were right hand dominant −75% underwent surgery in their dominant hand. Eleven of the nineteen joints were performed in the index finger, with the remainder in the middle finger. Mean follow up is 22.1 months (range 11–37). Results. At the 3 month post-operative hand therapy assessment, the arc of motion had improved from a mean of 32 degrees to 45 degrees and flexion had improved from a mean of 51 degrees to 66 degrees. Grip strength improved from a mean 20 to 27Kg. DASH scores significantly improved from a mean of 40 to 10 (p=0.01). All patients were satisfied with their outcomes and would have the surgery again. Pre-operative radiographs demonstrated joint narrowing in all patients but no evidence of heterotopic ossification, cystic change or erosions. Post-operatively, there has been no radiographic evidence of joint dislocation, resorption stress-shielding, loosening, migration or heterotopic ossification. There were three intra-operative complications of phalangeal fractures that were immediately treated with a cerclage wire. In one patient there has been a fracture of the proximal phalangeal implant at 14 months which was asymptomatic. One patient has required revision for mal-rotation of the implant leading to loss of index finger supination. Conclusion. Our results demonstrate excellent early results of pyrocarbon MCP joint arthroplasty in OA patients

Purpose. Evaluation of our experience on the treatment of comminuted, radial head fractures, and of the outcomes of pyrocarbon prosthetic replacement in such cases. Materials and Methods. We evaluated 47 cases of prosthetic replacement, performed from May 2003 to July 2008. There were 18 males and 29 females with an average follow-up of 48 months (12 to 60). The Hotchkiss classification was used to characterize the fractures. The indicators for the procedure were type III fractures in 27 cases, type IV fractures in 10 cases, comminuted radial head fractures (associated with disruption in medial collateral ligament) in 3 cases, Monteggia variant in 5 cases, and Essex Lopresti in 2 cases. Functional outcomes were assessed using the Mayo Elbow Performance Index and the Visual Analog Scales (VAS) of pain, joint motion, and stability. Results. The mean VAS score for elbow pain was 1 (0.5–2.1). Patients showed an average arch of motion from 6 degrees to 140, with 75 degrees of pronation, and 67 of supination. By the Mayo Elbow Performance Index, 42 patients had good to excellent results, 3 fair, and 2 poor. The complications that we have encountered were: implant dislocations (2 cases), elbow stiffness (1), implant dissociation (1), stem rupture (1), and transient PIN palsy (2 cases with complete recovery of nervous function at 5 and 8 weeks). There was no persistent instability, infection, synosthosis, severe degenerative changes, or impingement. Conclusion. The pyrocarbon implants are a good treatment option in complicated, radial head fractures, but the outcome depends on the severity of the initial fracture and the associated lesions. We have also encountered a tendency towards overestimating the prosthesis size, causing restriction of motion, impingement, overstuffing, or dislocation. For these results we are now using the non-modular prosthesis in our center, but further studies are required

Most fractures of the radial head are stable undisplaced or minimally displaced partial fractures without an associated fracture of the elbow or forearm or ligament injury, where stiffness following non-operative management is the primary concern. Displaced unstable fractures of the radial head are usually associated with other fractures or ligament injuries, and restoration of radiocapitellar contact by reconstruction or prosthetic replacement of the fractured head is necessary to prevent subluxation or dislocation of the elbow and forearm. In fractures with three or fewer fragments (two articular fragments and the neck) and little or no metaphyseal comminution, open reduction and internal fixation may give good results. However, fragmented unstable fractures of the radial head are prone to early failure of fixation and nonunion when fixed. Excision of the radial head is associated with good long-term results, but in patients with instability of the elbow or forearm, prosthetic replacement is preferred.

This review considers the characteristics of stable and unstable fractures of the radial head, as well as discussing the debatable aspects of management, in light of the current best evidence.

Cite this article: Bone Joint J 2013;95-B:151–9.