Calipered kinematic alignment restored the arithmetic hip-knee-ankle angle, achieved high satisfaction and improved clinical outcomes.

PURPOSE: The purpose of this study was to determine whether unrestricted calipered kinematic alignment (KA), coupled with a medial-stabilised (MS) implant system, can reproduce the patient's constitutional alignment as per the arithmetic hip-knee-ankle (aHKA) and improve clinical outcomes. METHODS: One-hundred and ninety-three patients received total knee arthroplasty by the senior author. To determine whether the constitutional alignment was achieved, the postoperative hip-knee-ankle (HKA) alignment was compared against the aHKA. Range of motion (ROM) was determined preoperative and postoperatively at 6 months and 2 years by measuring the active flexion and extension. Patient-Reported Outcomes Measures (PROMs) including Oxford Knee Score (OKS), Knee Injury and Osteoarthritis Outcome Score (KOOS), Forgotten Joint Score (FJS) and Visual Analogue Scale for Satisfaction were also completed. The Sports and Recreation component of KOOS was used to assess the patient's ability to return to sports and daily activities. RESULTS: There was a strong correlation between postoperative HKA and aHKA (r = 0.7, p < 0.05). There was a significant improvement in both extension and flexion seen from as early as 6 months postoperatively, with a mean flexion of 123° ± 11° and extension of 1° ± 3° at 2 years. PROMs had significant improvements with a mean score of 42.8 ± 6.0 for the OKS and all KOOS subscales consisting of Symptoms (88.0 ± 11.7), Pain (91.4 ± 11.6), Activities of Daily Living (91.1 ± 12.4), Sports (76.8 ± 22.1) and Quality of Life (83.0 ± 19.1). The FJS had significant improvements from 6 months to 2 years of 19.9 (p < 0.05), with a mean score of 69.2 ± 26.6 at 2 years. Ninety-three percent (180 patients) were classified as 'satisfied' at the 2-year timepoint. The KOOS Sports component was completed by 64% (124 patients), whereby the mean age was younger than the noncompliant patients (67.7 ± 9.4 vs. 71.7 ± 8.2 years). CONCLUSION: Unrestricted calipered KA can result in an alignment that closely resembles the patient's constitutional alignment, as per the aHKA. This resulted in improved knee ROM and patient satisfaction, as well as assisting younger patients to return to sports and daily activities. LEVEL OF EVIDENCE: Level IV.

Medial pivot design does not yield superior results compared to posterior-stabilised total knee arthroplasty: a systematic review and meta-analysis of randomised control trials.

PURPOSE: The aim of this meta-analysis was a comparison between medial pivot (MP) and posterior-stabilised (PS) knee designs regarding functional and radiological outcomes as well as gait parameters. METHODS: A systematic literature search was conducted in PubMed, Cochrane Library, Science Direct and Clinical Trials.gov from conception up to April 2022, to identify eligible randomised control trials (RCTs). The extracted data were analysed according to the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) statement. RESULTS: Fifteen studies met inclusion criteria, enrolling 1101 patients who underwent 1242 total knee arthroplasties (TKAs). A total of 1158 TKAs (581 MP/577 PS) were included in the quantitative analysis. Mean follow-up ranged from 6 months up to 6.6 years. MP knees showed comparable range of motion (ROM) with PS design 1, 2 and 4 years postoperatively (p = 0.2, p = 0.25, p = 0.34, respectively). No statistical difference was found in patient-related outcome measures (PROMs) (p > 0.05). Mean walking speed (MWS), length of stay (LOS), radiographic alignment and complications rates were also similar between the two groups (p > 0.05). DISCUSSION: The present meta-analysis demonstrated that the theoretical biomechanical advantage of MP implants does not have a better impact on patient satisfaction compared to the traditional PS knees. LEVEL OF EVIDENCE: I.

Medial stabilised total knee arthroplasty achieves comparable clinical outcomes when compared to other TKA designs: a systematic review and meta-analysis of the current literature.

PURPOSE: The purpose of this study was to perform a systematic review and meta-analysis to compare clinical and patient-reported outcome measures of medially stabilised (MS) TKA when compared to other TKA designs. METHODS: The Preferred Reporting Items for Systematic Review and Meta-Analyses algorithm was used. The Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, and EMCARE databases were searched to June 2020. Studies with a minimum of 12 months of follow-up comparing an MS TKA design to any other TKA design were included. The statistical analysis was completed using Review Manager (RevMan), Version 5.3. RESULTS: The 22 studies meeting the inclusion criteria included 3011 patients and 4102 TKAs. Overall Oxford Knee Scores were significantly better (p = 0.0007) for MS TKA, but there was no difference in the Forgotten Joint Scores (FJS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee Society Score (KSS)-Knee, KSS-Function, and range of motion between MS and non-MS TKA designs. Significant differences were noted for sub-group analyses; MS TKA showed significantly worse KSS-Knee (p = 0.02) and WOMAC (p = 0.03) scores when compared to Rotating Platform (RP) TKA while significantly better FJS (p = 0.002) and KSS-knee scores (p = 0.0001) when compared to cruciate-retaining (CR) TKA. CONCLUSION: This review and meta-analysis show that MS TKA designs result in both patient and clinical outcomes that are comparable to non-MS implants. These results suggest implant design alone may not provide further improvement in patient outcome following TKA, surgeons must consider other factors, such as alignment to achieve superior outcomes. LEVEL OF EVIDENCE: III.