J Matheson, C Frampton (Dunedin, New Zealand)
Introduction: This study was undertaken to assess any differences in revision rates for bilateral (one operation) and unilateral Total knee joint replacement patients in a single surgeon practice.
Methods: Using New Zealand National Joint Registry data all registered Total knee joint replacement patients in the author’s Public and Private practice from 1999 until the end of 2017 were reviewed.
Results: During the period of review, from commencement of the NZNJR, 214 (107 patients) bilateral Total knee joint replacements and 925 unilateral Total knee joint replacements were recorded.At mean follow up of 6.3 years no bilateral Total knee joint replacement patients had undergone revision surgery.At mean follow up of 7.1 years 15 unilateral Total knee joint replacement patients had undergone revision surgery (0.23 rate/100 component years).
8.4% of bilateral and 15.7% of unilateral Total knee replacement patients had died.
There was no statistically significant difference in revision rates for posterior cruciate ligament retaining (75%) and posterior stabilised (25%) total knee joint replacement patients.Revision rates were unaffected by patellar resurfacing (20%). There was no statistically significant difference in 6 month Oxford scores for patients with bilateral (38.9) or unilateral (39.6) Total knee joint replacements, or in patients with posterior cruciate retaining (39.4) and posterior stabilised (39.5) components. There were no significant differences in complications for bilateral and unilateral Total knee replacement patients.
Conclusion: This New Zealand National Joint Registry study demonstrates excellent medium term Total knee joint replacement survival outcomes for selected patients having bilateral Total knee joint replacement.