Outcome of unicompartmental knee arthroplasty in octogenarians with tricompartmental osteoarthritis: A longer followup of previously published report

Abstract

Background:Unicompartmental knee arthroplasty (UKA) has specific indications, producing excellent results. It, however, has a limited lifespan and needs eventual conversion to total knee arthroplasty (TKA). It is, therefore, a temporizing procedure in select active young patients with advanced unicompartmental osteoarthritis (UCOA). Being a less morbid procedure it is suggested as an alternative in the very elderly patients with tricompartmental osteoarthritis (TCOA). We performed UKA in a series of 45 octogenarians with TCOA predominant medial compartment osteoarthritis (MCOA) and analyzed the results.Materials and Methods:Forty five octogenarian patients with TCOA predominant MCOA underwent UKA (19 bilateral) from January 2002 to January 2012. All had similar preoperative work-up, surgical approach, procedure, implants and postoperative protocol. Clinicoradiological assessment was done at 3-monthly intervals for the first year, then yearly till the last followup (average 72 months, range 8-128 months). Results were evaluated using the knee society scores (KSS), satisfaction index [using the visual analogue scale (VAS)] and orthogonal radiographs (for loosening, subsidence, lysis or implant wear). Resurgery for any cause was considered failure.Results:Four patients (six knees) died due to medical conditions, two patients (three knees) were lost to followup, and these were excluded from the final analysis. Barring two failures, all the remaining patients were pain-free and performing well at the final followup. Indications for resurgery were: medial femoral condyle fracture needing fixation subsequent conversion to TKA at 2 years (n=1) and progression of arthritis and pain leading to revision TKA at 6 years (n=1).Conclusion:UKA has shown successful outcomes with regards to pain relief and function with 96.4% implant survival and 94.9% good or excellent outcomes. Due to lower demands, early rehabilitation, less morbidity, and relative short life expectancy, UKA can successfully manage TCOA in the octogenarians.

Assessing lateral femoral condyle cartilage prior to medial UKA: MRI vs. Valgus stress radiograph

“…Because low-grade cartilage injuries do not have much influence on the long-term effects of UKA [ 19 – 21 ], as long as image examination can distinguish between low-grade and high-grade injuries, it can become a suitable decision aid for UKA. Our study showed that the accuracy and specificity of MRI were much higher than valgus stress radiograph.…”

“…Outerbridge grade [ 18 ] (Table 1 ) was the gold standard and was assessed by an experienced surgeon for intraoperative cartilage assessment. Slight cartilage injury of the lateral compartment did not affect the efficacy of UKA [ 19 – 21 ]. So, patients with Outerbridge grades 0–2 (non-high-grade injuries) underwent UKA, while patients with Outerbridge grades 3–4 (high-grade injuries) underwent TKA.…”