The compartmental approach to revision of partial knee arthroplasty results in nearer-normal gait and improved patient reported outcomes compared to total knee arthroplasty

Abstract

Purpose This study investigated the gait and patient reported outcome measures of subjects converted from a partial knee arthroplasty to combined partial knee arthroplasty, using a compartmental approach. Healthy subjects and primary total knee arthroplasty patients were used as control groups. Methods Twenty-three patients converted from partial to combined partial knee arthroplasty were measured on the instrumented treadmill at top walking speeds, using standard gait metrics. Data were compared to healthy controls (n = 22) and primary posterior cruciate-retaining total knee arthroplasty subjects (n = 23) where surgery were performed for one or two-compartment osteoarthritis. Groups were matched for age, sex and body mass index. At the time of gait analysis, combined partial knee arthroplasty subjects were median 17 months post-revision surgery (range 4–81 months) while the total knee arthroplasty group was median 16 months post-surgery (range 6–150 months). Oxford Knee Scores and EuroQol-5D 5L scores were recorded at the time of treadmill assessment, and results analysed by question and domain. Results Subjects revised from partial to combined partial knee arthroplasty walked 16% faster than total knee arthroplasty (mean top walking speed 6.4 ± 0.8 km/h, vs. 5.5 ± 0.7 km/h p = 0.003), demonstrating nearer-normal weight-acceptance rate (p < 0.001), maximum weight-acceptance force (p < 0.006), mid-stance force (p < 0.03), contact time (p < 0.02), double support time (p < 0.009), step length (p = 0.003) and stride length (p = 0.051) compared to primary total knee arthroplasty. Combined partial knee arthroplasty subjects had a median Oxford Knee Score of 43 (interquartile range 39–47) vs. 38 (interquartile range 32–41, p < 0.02) and reported a median EQ-5D 0.94 (interquartile range 0.87–1.0) vs. 0.84 (interquartile range 0.80–0.89, p = 0.006). Conclusion This study finds that a compartmental approach to native compartment degeneration following partial knee arthroplasty results in nearer-normal gait and improved patient satisfaction compared to total knee arthroplasty. Level of evidence III.

Medial bicompartmental arthroplasty patients display more normal gait and improved satisfaction, compared to matched total knee arthroplasty patients

“…The ‘compartmental approach’ (Revision Partial Knee Classification PR2b [ 17 ]) advocates the addition of a second PKA to the newly degenerate compartment, while retaining the primary PKA and ACL [ 14 , 18 ]. It has been shown to preserve healthy gait characteristics, despite second surgery [ 16 ], reflecting the results of the present study.…”

“…The recorded OKS and EQ-5D scores are similar to widely reported literature values for UKA and TKA [ 8 , 26 , 36 ], with no apparent adverse effect as a consequence of the additional PFA in BCA-M subjects when compared to medial UKA, supporting the findings of others [ 29 ]. Higher satisfaction is also reported in those revised through a compartmental approach [ 16 ]. The significant differences observed on the OKS in relation to rising from a chair, kneeling down, stair descent and instability symptoms support the theory that BCA-M preserves isokinetic quadriceps strength and anterior–posterior stability, known to be compromised following TKA [ 13 , 15 , 27 ].…”

Unicompartmental knee replacement: controversies and technical considerations

“…They paired and compared their results with a TKA group and concluded that, after six months, UKR patients showed better quadricep strength and gait function compared to TKA patients, with less likelihood of stiffness and pain in the short term. Furthermore, Garner et al [143] conducted a cross-sectional study in which they aimed to measure gait and patient-reported outcomes in the cases of partial knee arthroplasty and combined partial knee arthroplasty compared to TKA using the compartmental approach. They concluded that patients who underwent the compartmental approach reported better outcomes and had a more normal gait during follow-up compared to TKA patients.…”

The risk of tibial eminence avulsion fracture with bi-unicondylar knee arthroplasty

“… 5 - 14 In particular, bi-unicondylar arthroplasty (Bi-UKA) is of interest for patients with a healthy patellofemoral compartment and functional cruciate ligaments, and either ipsilateral medial and lateral tibiofemoral OA, 4 , 5 , 11 , 12 or a well-functioning unicondylar arthroplasty (UKA) with subsequent degeneration in the other tibiofemoral compartment. 13 …”

“…Recent evidence suggests that Bi-UKA patients have superior outcomes and biomechanics compared to those with a similar disease pattern but treated with total knee arthroplasty (TKA). 11 - 13 , 15 However, a potential barrier to the wider use of this procedure is a perceived risk of compromising the anterior cruciate ligament (ACL) if the seemingly narrow bone island between the two tibial components fractures under ACL tension. Indeed, some authors have suggested that intraoperative tibial eminence avulsion fracture may occur in 4% to 9% of Bi-UKAs.…”