Multiple studies have shown that the symptomatology of knee osteoarthritis weakly correlate to radiographic severity of disease. Current literature however does not have much in the way of comparing functional outcomes of those with OA knees with radiographic severity. Our objective was to compare radiographic measurements of OA knees with self-reported functional outcomes and determine if radiographic severity of OA knees correlated with loss of functional ability. A retrospective review of prospectively collected registry data of 305 patients with osteoarthritis of the knee was collected. The patient's x-rays were reviewed, and radiographic measurements were taken to include medial, lateral and patellofemoral joint space distance measured in millimetres. The Kellgren and Lawrence, and Ahlback classifications of radiographic knee OA were computed. These were correlated with severity of functional limitations was measured using the SF36, Knee society score (KSS) and Oxford knee scores. Statistical analysis were conducted with SPSS V22.0 statistical software. Demographic characteristics and functional assessments were analysed using one way ANOVA test. Post-hoc test using Tukey HSD and effect size (partial-eta squared η2) was performed if one-way ANOVA was found to be statistically significant. A p-value of 0.05 or less was considered statistically significant. Pre-operative patient demographics are shown in table 1. Patients in with Grade 2 osteoarthritis were significantly younger than Grade 4 patients (post-hoc p=0.003). There were no statistically significant differences in age between the other Grades, and there were no differences in BMI or gender or operative site between all grades. There were significant differences in KSS Function scores between Grade 2 and Grade 3 patients (post-hoc p=0.017) and Grade 2 and 4 patients (post-hoc p < 0 .001). Statistically significant differences were also found between Grade 1 and Grade 4 patients for the KSS Knee score (post-hoc p=0.016). There were significant differences in Oxford knee score (post-hoc p=0.026) and SF- Physical Function (post-hoc p < 0 .001) between Grade 2 and Grade 4 patients too. The effect size η2 for KSS Function, KSS Knee and Oxford knee score was 0.05, 0.06 and 0.33 respectively. When comparing the loss of joint space with the functional scores, there were no statistically significant correlations. Our study show that the radiological severity of knee osteoarthritis based on the two scoring methods was able to correlate with worsening functional scores. Most notably, the differences in KSS function scores correlated strongly between Grade 2 and Grade 3 patients. Of note, there was no correlation between the loss of joint space and the severity of functional limitations across any of the scoring systems. Our study showed that although both the Kellgren and Lawrence and Ahlback radiological grading of Osteoarthritis were able to correlate with worsening functional scores, this was not due to loss of joint space alone and further studies need to be conducted on the other contributors to the scoring system such as osteophytes and subchondral sclerosis. Our study show that the radiological severity of knee osteoarthritis based on the two scoring methods was able to correlate with worsening functional scores. Most notably, the differences in KSS function scores correlated strongly between Grade 2 and Grade 3 patients. Of note, there was no correlation between the loss of joint space and the severity of functional limitations across any of the scoring systems. Our study showed that although both the Kellgren and Lawrence and Ahlback radiological grading of Osteoarthritis were able to correlate with worsening functional scores, this was not due to loss of joint space alone and further studies need to be conducted on the other contributors to the scoring system such as osteophytes and subchondral sclerosis. For any figures or tables, please contact authors directly.
Computer-navigated total knee arthroplasty has been shown to improve the outcome in outliers with consistent results. The aim of this study is to evaluate the clinical and radiographic outcomes of computer-navigated knee arthroplasty with respect to deformity and body mass index (BMI). Data was prospectively collected for 117 consecutive patients undergoing primary computer-navigated total knee arthroplasty using Ci Brainlab system with J&J PFC PS implants by a single surgeon utilising a tibia cut first, gap-balancing technique. Pre-operative and post-operative long-leg films, weight-bearing, films were taken and the long-axis was measured by a single observer. Intra-operative computer navigation long-axis values were stored as screenshots intra-operatively after registration and after implant was cemented. BMI, range of motion (ROM), SF 36 and Oxford knee scores were recorded both before surgery and on follow-up. Minimum 2-year follow-up. Eight patients were lost to follow-up and 8 had incomplete 2 year data. Data was analysed using the Chi-squared test for categorical variables and the t-test for continuous variables.Aim
Materials and Methods
Restoration of the native joint line in total knee arthroplasty is important in restoring ligamentous balance and normal knee kinematics. Failure to achieve this could lead to reduced range of motion, patellofemoral maltracking and suboptimal outcomes. The purpose of this study was to analyse the clinical and functional outcome of patients who demonstrated joint line changes after computer-assisted (CAS) total knee arthroplasty (TKA). A prospective study was conducted for 168 patients (168 knees) who underwent CAS TKA by two surgeons at a single institution with an average follow-up of two years. The final change in joint line was calculated from the verified tibial resection, distal and posterior femoral cuts. Group A patients had joint line changes of less than 4mm and Group B patients had joint line changes of more than 4mm. Postoperative Oxford scores, Knee scores, Function scores and SF-36 scores were obtained at six months, one year and two years post-TKA. The final range of motion and the mechanical alignment were documented. There was significant linear correlation between joint line changes and Oxford scores (p = 0.05) and Function scores (p = 0.05) at six months and Oxford scores alone at two years with increasing joint line changes having poorer outcome scores. Group A compared to Group B patients have better outcomes in terms of Oxford scores (mean 20 vs 27, p = 0.0003), Function scores (mean 69 vs 59, p = 0.03), SF-1 (mean 63 vs 50, p = 0.03), SF-2 (mean 66 vs 43, p = 0.05), SF-5 (mean 75 vs 63, p = 0.04), SF-6 (mean 84 vs 59, p = 0.003), SF-7 (mean 96 vs 83, p = 0.02), SF-8 (mean 84 vs 73, p = 0.006) and total SF-36 scores (mean 603 vs 487, P = 0.003), at six months, and Oxford scores (mean 18 vs 23, p = 0.0007) at two years. In this study, CAS is a useful intra-operative tool for assessing the final joint line in TKA. Outliers in joint line changes of ≥ 4 mm are associated with poorer clinical outcome scores.
