The unicompartmental knee is the preferred side in individuals with both a unicompartmental and total knee arthroplasty

Abstract

Purpose To determine the preferred knee in patients with both one total and one unicompartmental knee arthroplasty. Method Patients simply with a unicompartmental (UKA) and total knee arthroplasty (TKA) on contralateral sides were retrospectively screened from three senior knee surgeon's logs over a 15 year period. Patients safe and free from other diseases to affect gait were approached. A total of 16 patients (mean age 70 ± 8) agreed to ground reaction force testing on an instrumented treadmill at a fair pace and incline. A gender-ratio identical group of 16 healthy control subjects (mean age 67 ± 10) and 16 patients with ipsilateral medial knee OA (mean age 66 ± 7) were analysed to compare. Results Radiographically the mode preoperative Kellgren-Lawrence knee grade for each side was 3. Postoperatively, the TKA side had a mean coronal femoral component alignment of 7° and a mean tibial coronal alignment of 89° with a mean posterior slope of 5° in the sagittal plane. The UKA side had a mean coronal femoral component alignment of 7° and a mean tibial coronal alignment of 86° with a mean posterior slope of 4° in the sagittal plane. In 7 patients, the TKA was the first procedure, while 6 for the UKA and 3 done simultaneously. Gait analysis demonstrated in both walking conditions the UKA limb was the preferred side through all phases of loading (p < 0.05) and nearer to normal than the TKA limb when compared to healthy controls and patients with knee OA. The greatest difference was observed between the transition of weight acceptance and midstance (p = 0.008), when 22% more load was taken by the UKA side. Conclusion By using a dynamic metric of an everyday activity, a distinct gait difference between differing arthroplasty types were established. A more natural loading pattern can be achieved with unicompartmentals as compared to total knees. Level of evidence Retrospective comparative study, Level III.

The extensor efficiency of unicompartmental, bicompartmental, and total knee arthroplasty

“… 47 - 51 Clinically, data suggest that walking on a slope with a TKA in situ is functionally more difficult than post-UKA. 7 However, in this study, no differences were detected over this range of flexion. Differences in slope walking may be a consequence of other factors, such as loss of proprioception following resection of the cruciate ligaments, rather than differences in extensor function.…”

“…More than 1.5 million total knee arthroplasty (TKA) procedures are performed annually worldwide 1 to treat end-stage osteoarthritis (OA) in one, two, or three knee compartments. 2 - 5 While many patients benefit from TKA, for some, poor postoperative function can lead to disability, especially on stairs or when walking on slopes, 6 , 7 and patient dissatisfaction rates of up to 25% have been reported. 8 - 11 Consequently, there has been much recent debate in the orthopaedic community regarding how to improve knee function and patient satisfaction following arthroplasty.…”

“…For patients with functional cruciate ligaments, and disease isolated to one tibiofemoral knee compartment, the use of unicompartmental knee arthroplasty (UKA) instead of TKA can lead to improved patient satisfaction and knee function, with reported benefits including faster gait, greater range of motion, and earlier return to desired activity. 7 , 17 - 21 There is also renewed interest in combined partial knee arthroplasty (CPKA) 22 , 23 where combinations of two or more partial knee arthroplasty (PKA) implants are used in the same knee. 24 Recent data have suggested that two-thirds of TKA patients could be candidates for PKA or CPKA.…”

Comparison of Functional Outcome of Total and Unicompartmental Knee Arthroplasty Using Computer-Assisted Patient-Specific Templating

“…The current operative treatment modalities of advanced osteoarthritis are total knee arthroplasty (TKA) and unicompartmental knee arthroplasty (UKA). However, replacing all the affected and nonaffected surfaces is considered the gold standard procedure [ 2 , 3 ]. On the other hand, many surgeons argue the superiority of UKA in unicompartmental cases to spare the undamaged compartments, despite having higher revision rates when compared to TKA [ 2 , 4 ].…”

Robotic arm-assisted bi-unicompartmental knee arthroplasty maintains natural knee joint anatomy compared with total knee arthroplasty: a prospective randomized controlled trial

“…It has been shown that patients with a UKA and a contralateral TKA tend to favour the UKA, which maintains a more natural gait. 16 - 18 UKA also offers faster recovery, less postoperative pain, and lower rates of thromboembolism, cerebrovascular events and 30-day mortality, compared with TKA. 19 …”