Abstract
There are limited medium-term outcome data available for the Repicci II device in
unicompartmental knee arthroplasty (UKA). The purpose of this study was to report
the medium-term (minimum 2 years) patient-reported outcomes and long-term (up to 14
years) procedure survival in a consecutive series of patients undergoing an inlay
prosthesis UKA (Repicci II) at an independent orthopaedic clinic. Patients presenting
with medially localized unicompartmental knee osteoarthritis and meeting the criteria
appropriate for UKA were recruited to a clinical patient registry at the time of presentation.
A cemented unicompartmental prosthesis (Repicci II) was implanted using minimally
invasive techniques with rapid postoperative mobilization. Patients were asked to
complete patient-reported outcomes preoperatively and annually postoperatively. A
procedure list was cross-matched with the Australian Orthopaedic Association National
Joint Replacement Registry (AOANJRR), and an analysis of procedure survival was performed
with comparison to the national data for UKA. Data from a cohort of 661 primary medial
compartment UKA procedures performed in 551 patients over a 15-year period were extracted
from the clinical patient registry. Significant improvements were maintained in general
health, disease symptoms, pain, and function at an average follow-up of 9 years compared
with preoperative data. Threshold analysis revealed that >65% of patients exceeded
Patient Acceptable Symptom State at the latest follow-up, with >80% within or exceeding
age-matched norms for general health. Cumulative revision rate was significantly lower
than that reported for UKA in the AOANJRR at up to 13 years follow-up. This series
represents a lower cumulative revision rate than previously reported, with >65% of
patients reporting satisfactory functional outcomes at an average of 9 years from
surgery. Surgical options for treating unicompartmental knee osteoarthritis could
include UKA as a viable alternative; however, clear definitions of procedure success
and its overall cost–benefit ratio in the context of ongoing management of knee osteoarthritis
remain to be elucidated.
Keywords unicompartmental knee arthroplasty - patient-reported outcomes - long-term follow-up
