Modelling Knee Range of Motion Post Arthroplasty: Clinical Applications

Abstract

Purpose: To model change in knee range of motion (ROM) post total knee arthroplasty (TKA) and to show how this information can be incorporated into clinical decision making. Method: We applied a variable-occasion repeated-measures study design. Patients' knee flexion and extension ROM were assessed pre-and post arthroplasty over the ensuing 60 weeks. We examined change in ROM post TKA using linear and nonlinear mixed-effects modelling, and examined whether age, body mass index, prearthroplasty ROM, and gender were determinants of recovery in post-arthroplasty ROM. Results: Of 93 eligible patients, 74 provided pre-and post-arthroplasty data. A random intercept nonlinear model fit the flexion data best, and a random intercept linear model fit the extension data best. Pre-arthroplasty ROM was found to be a determinant of recovery in ROM post arthroplasty. This finding was common to both flexion and extension models. Conclusions: Our study showed that the greatest improvement for knee ROM took place during the first 12 weeks post arthroplasty. Of the variables examined, only pre-arthroplasty ROM was a determinant of outcome (p < 0.05). The study results provide clinicians with data to determine expected rates of improvement for patients as well as the projected maximum ROM, facilitating improved clinical decision making. RÉ SUMÉObjectif : Modé liser le changement dans l'amplitude de mouvement du genou à la suite d'une arthroplastie totale du genou et dé montrer comment cette information peut ê tre incorporé e à la prise de dé cision clinique. Mé thode : Nous avons appliqué un modè le d'é tude avec mesures ré pé té es à des occasions variables. L'amplitude du mouvement du genou du patient au moment de la flexion et de l'extension a é té é valué e avant et aprè s l'arthroplastie, dans les 60 semaines qui ont suivi l'intervention. Nous avons examiné les changements à l'amplitude des mouvements aprè s l'intervention à l'aide d'un modè le à effets mixtes liné aire et non liné aire, et tenté de voir si l'â ge, l'indice de masse corporelle, l'amplitude de mouvement pré -arthroplastie et le sexe constituaient des dé terminants dans la ré cupé ration de l'amplitude de mouvement post-arthroplastie. Ré sultats : Des 93 patients admissibles, 74 ont fourni des donné es avant et aprè s l'arthroplastie. Un modè le non liné aire d'interception alé atoire convenait mieux aux donné es sur la flexion, tandis qu'un modè le liné aire d'interception alé atoire convenait mieux aux donné es sur l'extension. On a constaté que l'amplitude de mouvement pré -arthroplastie é tait dé terminante dans la ré cupé ration de l'amplitude de mouvement post-arthroplastie. Cette conclusion é tait la mê me pour la flexion que pour l'extension. Conclusions : Notre é tude a dé montré que la plus grande amé lioration à l'amplitude de mouvement du genou avait lieu dans les 12 semaines aprè s l'arthroplastie. Parmi les autres variables examiné es, seule l'amplitude de mouvement pré -arthroplastie constituait un ré sultat dé terminant (p < 0,05). Les ...

Continuous passive motion and its effects on knee flexion after total knee arthroplasty in patients with knee osteoarthritis

“…Limited knee flexion 1 year after TKA was addressed by Miner et al [34], who observed significantly lower knee function in patients with knee flexion <95° compared with that of patients with knee flexion >95°. Although knee flexion at acute-stay discharge might not be an accurate prognostic factor of long-term knee functional outcomes 6 months or longer after TKA [3,39], it is a useful indicator during the early post-arthroplastic stages and a significant determinant of early functional outcomes [9,39,45]. In addition, joint kinematics (i.e.…”

The Combination of Exercise and Manual Therapy Versus Exercise Alone in Total Knee Arthroplasty Rehabilitation: A Randomized Controlled Clinical Trial

“…Established MCIDs for the NPRS, knee flexion ROM, total WOMAC score, and SF12-PCS have been suggested as 1.5 points, 9.6 points , 10 points, and 1.8 points, respectively. 28,[30][31][32] Effect sizes were determined calculating the differences in the means of the baseline and the follow-up data divided by the SD at the baseline and effect sizes of 0.2, 0.5, and 0.8 were considered small, moderate, and large, respectively. 33…”

“…This difference was higher than the reported MCID for flexion by Stratford et al (9.6 ). 28 Additionally, the nonsignificant interaction effect was observed with ANCOVA for baseline knee flexion ROM degrees (P = .25).…”

“…The calculation was based on the following parameters: 2-sided test, alpha error of 0.05, 80% of power, a difference of 9.6 between the average knee flexion of two groups, and SDs of 9.1 and 10.2 . 28 These parameters suggested a sample size of at least 16 patients for each group. Because of the possibility of dropouts, 42 patients were recruited into the study.…”

Robotic Arm-Assisted versus Manual Total Knee Arthroplasty: A Propensity Score-Matched Analysis

“…First, the difference in ROM between the two cohorts was 8 degrees which is below a modeled, minimal detectable change of 9.6 degrees. 32 The measurements were performed in an office setting with the possibility of inter-and intra-observer errors. Therefore, larger studies with multiple raters and an established protocol for ROM measurement may be needed before reaching conclusions.…”