Abstract
Introduction: Treatment of dual compartment osteoarthritis remains controversial, with conjecture over whether Uni-Compartmental (‘UKA’) or Total Knee Arthroplasty (‘TKA’) is more appropriate for patients with patello-femoral disease. The ‘Journey Deuce’ 2/3 Knee Arthroplasty (‘2/3 Knee’) (Smith & Nephew) is a bi-cruciate retaining prosthesis designed to treat this subgroup of patients with both antero-medial and patello-femoral disease.
We have conducted a prospective, observational clinical trial of 34 patients with dual compartment osteoarthritis of the knee treated with a 2/3 Knee.
Aims: To assess the safety and clinical efficacy outcomes of the 2/3 Knee.
Method: All patients pre-op leg alignment films, as well as MRI or arthroscopy to confirm the inclusion criteria of dual compartment osteoarthritis with a preserved lateral compartment and intact cruciate ligaments. All operations were performed by a single surgeon (DW) using computer assisted surgery (CAS) and a minimally invasive technique (MIS) at a local university affiliated private hospital (HPH).
Exclusion criteria included obesity, inflammatory arthritis and a fixed flexion deformity > 10 degrees.
Subjective outcome measures included Oxford Knee Scores (OKS) and EQ-5D Scores. RSA beads were implanted at surgery to detect loosening, micro-motion and prosthesis wear. Gait analysis was conducted at 1 year post op in a subgroup of patients.
Results: Follow up ranged from 6 months to 2 years. There have been no early failures requiring complete revision. The first 23 knees (18 patients) did not have primary resurfacing of the patella. Some of these patients suffered palpable and audible patello-femoral crepitus, with a subgroup (17%, 4 knees-3 patients) having associated anterior knee pain. This subgroup had revision procedures to resurface their patellae with resolution of their symptoms. All subsequent patients have had primary patella resurfacing with no incidence of Significant crepitus or anterior knee pain.
The patients have recorded Significant improvement in their Oxford Knee Scores at 6 months (mean reduction all patients: 17.3, resurfaced 20).
Early RSA results have not detected Significant migration to indicate early loosening. Gait analysis has shown that patients return to approximate normal rather than pre-operative gait.
Conclusions: Although longer follow up is required the 2/3 Knee appears a safe and effective treatment option for patients with dual-compartment osteoarthritis; with rehabilitation, function and gait tending towards that seen in UKA rather than TKA.
It is essential that patients undergo primary patella resurfacing to prevent crepitus and associated anterior knee pain.
A study comparing clinical outcomes of 2/3 Knee vs TKA is underway at our institution.
The abstracts were prepared by David AF Morgan. Correspondence should be addressed to him at davidafmorgan@aoa.org.au
Declaration of interest: b
