A review of the New Zealand National Joint Registry to compare the outcomes of Coonrad-Morrey and Latitude total elbow arthroplasty.

BACKGROUND

Total elbow arthroplasty has traditionally been used in the treatment of inflammatory arthropathy patients. More and more, however, its use is expanding to include acute trauma and sequelae of trauma. In New Zealand, the most commonly used prosthesis is the Coonrad-Morrey prosthesis, but the Latitude prosthesis has gained in popularity, with a 3-fold increase in implantation over the past 5 years.

METHODS

Prospectively collected national joint registry data were used to compare the survival rates of these prostheses. Underlying diagnoses, reasons for revision, and patient-reported outcome measures, as well as patient age and exact implants used, were all recorded. Statistical analysis involved survival analysis using Kaplan-Meier curves and the paired Student t test.

RESULTS

Over the 18-year study interval, the Coonrad-Morrey prosthesis has shown consistently lower revision rates than the Latitude prosthesis. This was true for both the linked and unlinked Latitude prostheses and was not affected by radial head replacement or underlying diagnosis. In all cases, the risk of revision for the Coonrad-Morrey prosthesis was reduced by at least 65% compared with the Latitude prosthesis.

CONCLUSION

This study using New Zealand Joint Registry data shows a lower failure rate of the Coonrad-Morrey elbow prosthesis compared with the Latitude prosthesis. The hazard ratio for a revision procedure for the Coonrad-Morrey prosthesis compared with the Latitude prosthesis was 0.28 (95% confidence interval, 0.14-0.55). This lower rate was evident irrespective of linkage and radial head replacement. The reason for the lower rate of revision with the Coonrad-Morrey prosthesis is likely multifactorial, but perhaps when used by lower-volume surgeons, the Coonrad-Morrey prosthesis may confer better implant longevity.