Does Patient-Specific Instrumentations Improve Short-Term Functional Outcomes After Total Knee Arthroplasty? A Systematic Review and Meta-Analysis

AbstractKinematically aligned total knee arthroplasty (KATKA) was developed to more anatomically align the knee prosthesis to restore the native alignment of the knee and promote physiological kinematics. Even though there are concerns with implant survival, and follow-up at 10 years or more after KATKA has not been reported, there is a negligible incidence of failure of a tibial component at 2 to 9 years. Early clinical results with this technique are encouraging and demonstrate better functional outcomes compared with mechanically aligned TKA (MATKA). The purpose of this study is to perform a systematic review and meta-analysis of the literature to determine whether there are any clinical differences between KATKA and MATKA. The authors conducted a systematic review of the English literature. Five randomized controlled trials (RCTs) which compared clinical outcomes of KATKA and MATKA were finally included. Four RCTs used patient-specific instrument, and one RCT used navigation. Data were extracted and meta-analysis was conducted. KATKA patients had better outcomes: Mean difference between KATKA and MATKA and p-value are presented in brackets after each variable: the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) (–12.5; p < 0.0001), Oxford Knee Score (OKS) (2.3; p = 0.030), combined Knee Society Score (C-KSS) (13.1; p < 0.0001), Knee Function Score (KFS) (6.4; p = 0.0070), and postoperative range of motion (ROM) (4.1°; p = 0.0010). There was no significant difference concerning the complication rates which needed reoperations or revision surgery (odds ratio, 1.01; p = 0.99). KATKA components had a more femoral valgus (–1.8°; p < 0.0001), more tibial varus (1.2°; p = 0.0001), and more tibial slope (1.2°; p = 0.0001), all being statistically significantly different. Better clinical outcomes were obtained in KATKA and component placement in KATKA is significantly different from that in MATKA. There was no increase of patients with poor clinical results due to implant position especially for varus placement of tibial component. This systematic review of five RCTs suggests that KATKA is of potential alternative method to MATKA since the risk of revision for tibial loosening is negligible compared with MATKA for the same follow-up period.

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Does Kinematic Alignment Improve Short-Term Functional Outcomes after Total Knee Arthroplasty Compared with Mechanical Alignment? A Systematic Review and Meta-analysis

The Journal of Knee Surgery ◽

10.1055/s-0037-1602136 ◽

2017 ◽

Vol 31 (01) ◽

pp. 078-086 ◽

Cited By ~ 17

Author(s):

Yanhong Li ◽

Yuliang Wang ◽

Mingxuan Yang ◽

Shuanke Wang

Keyword(s):

Total Knee Arthroplasty ◽

Knee Arthroplasty ◽

Functional Outcomes ◽

Mechanical Axis ◽

Meta Analysis ◽

Mechanical Alignment ◽

Short Term ◽

Significant Difference ◽

Total Knee

AbstractThis meta-analysis was conducted to study whether kinematically aligned total knee arthroplasty (TKA) improves short-term functional outcomes compared with mechanical alignment without changing the hip–knee–ankle angle. Prospective cohort studies were searched from electronic literature databases, including PubMed, Web of Science, Embase (Ovid interface), and Cochrane Library (Ovid interface). Total 1,159 records were identified. Six trials involving 561 patients were eligible for data extraction and meta-analysis. The included studies recorded outcomes in the follow-up range from 6 to 34 months. Primary outcomes were to assess the functional outcomes in follow-up, and KA group achieved better performance on WOMAC score (mean difference [MD] = −18.82, 95% CI: −16.06 to −5.58), knee function score (MD = 7.23, 95% CI: 0.52–13.94), Oxford knee score (MD = 4.76, 95% CI: 0.40–9.12), and knee range of flexion (MD = 4.48, 95% CI: 2.09–6.86), whereas other parameters including Knee Society score, knee range of extension, VAS pain score, and the occurrence of the complications were without significant difference (p > 0.05). Second outcomes evaluated the perioperative clinic indexes. Our meta-analysis showed that KA group had a shorter time of operation (MD = −15.44, 95% CI: −27.47 to −3.71) and a longer walk distance before discharge (MD = 53.24, 95% CI: 21.32–85.15) when compared with the MA group, whereas the change in hemoglobin, incision length, knee range of flexion before discharge, and length of stays were without significant difference (p > 0.05). Third outcomes were used to analyze the alignment data. Our study showed that KA had larger angles of femoral component and mechanical axis of the femur (MD = −1.95,95% CI: −2.77 to −1.13), tibial component and mechanical axis of tibia (MD = 2.06, 95% CI: 1.43–2.70), anatomic knee angle (MD = −0.72, 95% CI: −1.33 to −0.11), and operative limb alignment (MD = −1.97, 95% CI: −2.50 to −1.45,) compared with the MA group, but the hip–knee–ankle angles between the two groups were similar. KA provided better functional outcomes and better flexion following short-term follow-up of TKA. However, longer-term follow-up and larger sample studies are needed to put into research in the future.

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