Introduction:
The Aptis[BS1.1][MZ1.2][KS2.1][MZ2.2] DRUJ prosthesis is a semi-constrained, total[KS3.1][MZ3.2] distal radioulnar joint (DRUJ) replacement, indicated for end stage arthritis and as a salvage for other failed DRUJ procedures. Used internationally since it’s development in 1997, with documented good outcome, it’s use in New Zealand has never been audited. The aim of[KS4.1] this study was to comprehensively evaluate the outcome of Aptis DRUJ replacement in a nationwide cohort of New Zealand patients.
Methods:
All patients who underwent an Aptis semi-constrained total DRUJ arthroplasty between 2010 and 2020. Participant demographics, indications for surgery and the details of previous wrist surgeries were obtained. Assessment included subjective, physical and radiological examination. Functional outcomes were evaluation using the Mayo Wrist Score, Patient Rated Wrist/Hand Evaluation (PRWHE) and Quick Disability of Hand and Shoulder (QuickDASH) scores. Implant survival and re-operations were recorded. Univariate and multivariate analysis were performed to identify risk factors for poor functional outcomes.
Results:
A total of 46 joints were replaced in 43 patients, 34 joints (74%) were assessed in person. The mean follow-up period was 6.8 years. Implant survivorship was 94%. Including two implant failures, the re-operation rate was 24% (8 joints). Two[KS5.1][MZ5.2] joints were radiologically loose with excellent clinical outcomes.
Mean Mayo Wrist, PRWHE and Quickdash scores were 74 (SD20), 36 (SD30) and 33 (SD26) respectively. Mean active supination and pronation were 71° and 79°, and mean grip strength was 21kg. At final follow up, 23/34 (65%) joints had a good composite outcome as defined by a Mayo score of >65. Previous wrist fusion, concurrent surgical wrist procedures and more than one prior operation on the same wrist were significant risk factors for a poor composite outcome as defined as a Mayo Wrist Score below 65.
Conclusions:
With an average follow-up of nearly 7 years, our results for the Aptis semi constrained DRUJ prosthesis are comparable with those reported in the literature. However, our audit showed that outcomes were less favourable in patients with previous wrist fusion and those who have undergone multiple prior procedures or who have concurrent wrist surgery. We conclude that this procedure is a reasonable surgical solution for the very difficult problem of end stage DRUJ pathologies but that patient selection is crucial; the indications for the procedure must be carefully assessed and the conditions of the recipient patient must be appropriate to proceed.
