Knee Surg Sports Traumatol Arthrosc DOI 10.1007/s00167-014-3212-1
Knee
Recovery in knee range of motion reaches a plateau by 12 months after total knee arthroplasty Zhihong Zhou · Khye Soon Andy Yew · Earnest Arul · Pak‑Lin Chin · Keng Jin Darren Tay · Ngai‑Nung Lo · Shi‑Lu Chia · Seng Jin Yeo
Received: 19 June 2013 / Accepted: 28 July 2014 © Springer-Verlag Berlin Heidelberg 2014
Abstract Purpose The primary aim of this study was to identify the time point at which improvements in knee range of motion reach a plateau, if any. The secondary aim of this study was to investigate the correlation between the improvements in knee range of motion and patient-reported outcomes [Oxford knee score (OKS) and SF-36]. The hypothesis is that there is a time point at which the recovery in the knee range of motion after total knee arthroplasty (TKA) plateaus. Method A prospective study of 145 patients who underwent TKA was conducted. All TKAs were performed by the same surgeon. OKS and SF-36 scores were measured preoperatively and at 6, 12, and 24 months. Range of motion was measured preoperatively and at 1, 3, 6, 12, and 24 months postoperatively. Results This study shows that for surgeon/therapist reported range of motion, a plateau in recovery was reached at 12 months after TKA. It was also found that range of extension is significantly correlated with OKS, whereas range of flexion was not significantly correlated with OKS. Conclusions Knowledge of when patients fully recover after TKA will allow appropriate counseling of patients during preoperative consultation. Also, this knowledge will enable surgeons/therapists to better monitor the rehabilitation progress of TKA patients, and make adjustments to the rehabilitation
Z. Zhou (*) · K. S. A. Yew · P.-L. Chin · K. J. D. Tay · N.N. Lo · S.-L. Chia · S. J. Yeo Department of Orthopaedic Surgery, Singapore General Hospital, Academia Level 4, 20 College Road, Singapore 169856, Singapore e-mail: [email protected] E. Arul Duke-NUS Graduate Medical School, 8 College Road, Singapore 169857, Singapore
protocol. In addition, our study shows that objective surgeon-/ therapist-measured outcome (range of motion) has a significant correlation with subjective patient-reported outcomes (OKS). Hence, both outcome measures should be employed in the postoperative monitoring of patient progress. Level of evidence Prospective case series, Level IV. Keywords Total knee arthroplasty · Range of motion · Recovery plateau
Introduction Knee range of motion is an important outcome of total knee arthroplasty (TKA). It has been documented that 67° of flexion is required for swing phase in gait, 83° is required for stairs climbing, 90° is required to go downstairs, and 93° of flexion is required to rise from a seated position [1]. It has been reported that patients with a limited preoperative knee flexion angle significantly improved after total knee arthroplasty while patients with a good preoperative knee flexion angle had limited improvements or had a postoperative flexion less than the preoperative flexion angle. On the other hand, it has been shown that preoperatively stiff knees were likely to have a limited postoperative knee flexion angle [5]. It is essential to address the expectation of patients contemplating TKA. Patient dissatisfaction following TKA may be as high as 15–20 % [16]. With an aging population that is staying active after retirement age, there is an increasing expectation for improvement after TKA. Among various reasons for patient dissatisfaction, inadequate preoperative counseling could be one of the contributing factors. To that effect, information regarding the time course of recovery from TKA allows patients to have realistic expectations about their progress.
13
There is no consensus regarding the time course of improvement in knee range of motion following TKA. The primary aim of this study was to identify the time point at which improvements in the knee range of motion reach a plateau, if any. The secondary aim of this study was to investigate the correlation between the improvements in knee range of motion and the patient-reported outcomes (Oxford knee score and SF-36). The hypothesis is that there is a time point at which the recovery in the knee range of motion after TKA plateaus.
Materials and methods A prospective study of patients who underwent TKA at a large regional hospital was conducted. Patients who underwent both unilateral and bilateral primary TKA for osteoarthritis were included in this study. Patients who underwent revision TKA, who had a history of rheumatoid arthritis, and who had septic arthritis were excluded from this study. All operative procedures were performed by the same surgeon between 2007 and 2009. Cruciate-retaining implants were used in 77 patients, and posterior-stabilized implants were used in 68 patients. All patients underwent the same postoperative rehabilitation protocol. Knee range of extension and flexion was measured preoperatively and at 1, 3, 6, 12, and 24 months. Measurement of knee range of motion was carried out using goniometry, accurate up to 0.1°. The landmarks used in the measurements are the greater trochanter of the femur, the proximal head of the fibula, and the lateral malleolus. Goniometry was used as it has been reported that goniometric measurements of range of motion are more reliable than visual observation [8]. All measurements were carried out by a single trained physical therapist to eliminate inter-observer variability. In addition, patients were scored in the OKS and SF36 preoperatively and at 6, 12, and 24 months postoperatively. The same physical therapist administered OKS and SF-36 scores. The OKS consists of 12 questions, which are summed to give a total score. The minimum score is 12 and the maximum score is 60. A lower score corresponds to better outcome [12]. The SF-36 physical (PCS) and mental (MCS) component summary scores were computed. A higher score corresponds to a better outcome [18]. Approval for this study was given by SingHealth Centralized Institutional Review Board (CIRB/2012/2097/D). Statistical analysis Statistical analysis was carried out in consultation with an in-house biostatistician, using Stata 11 (StataCorp. 2009. Stata Statistical Software: Release 11. College Station, TX: StataCorp LP). Specifically, the generalized estimating
13
Knee Surg Sports Traumatol Arthrosc
equation (GEE) model was used to analyze data. Pair-wise comparison with Bonferroni’s correction was performed to assess whether there were differences in means between adjacent time points. Differences were considered to be statistically significant if p value was
Knee
Recovery in knee range of motion reaches a plateau by 12 months after total knee arthroplasty Zhihong Zhou · Khye Soon Andy Yew · Earnest Arul · Pak‑Lin Chin · Keng Jin Darren Tay · Ngai‑Nung Lo · Shi‑Lu Chia · Seng Jin Yeo
Received: 19 June 2013 / Accepted: 28 July 2014 © Springer-Verlag Berlin Heidelberg 2014
Abstract Purpose The primary aim of this study was to identify the time point at which improvements in knee range of motion reach a plateau, if any. The secondary aim of this study was to investigate the correlation between the improvements in knee range of motion and patient-reported outcomes [Oxford knee score (OKS) and SF-36]. The hypothesis is that there is a time point at which the recovery in the knee range of motion after total knee arthroplasty (TKA) plateaus. Method A prospective study of 145 patients who underwent TKA was conducted. All TKAs were performed by the same surgeon. OKS and SF-36 scores were measured preoperatively and at 6, 12, and 24 months. Range of motion was measured preoperatively and at 1, 3, 6, 12, and 24 months postoperatively. Results This study shows that for surgeon/therapist reported range of motion, a plateau in recovery was reached at 12 months after TKA. It was also found that range of extension is significantly correlated with OKS, whereas range of flexion was not significantly correlated with OKS. Conclusions Knowledge of when patients fully recover after TKA will allow appropriate counseling of patients during preoperative consultation. Also, this knowledge will enable surgeons/therapists to better monitor the rehabilitation progress of TKA patients, and make adjustments to the rehabilitation
Z. Zhou (*) · K. S. A. Yew · P.-L. Chin · K. J. D. Tay · N.N. Lo · S.-L. Chia · S. J. Yeo Department of Orthopaedic Surgery, Singapore General Hospital, Academia Level 4, 20 College Road, Singapore 169856, Singapore e-mail: [email protected] E. Arul Duke-NUS Graduate Medical School, 8 College Road, Singapore 169857, Singapore
protocol. In addition, our study shows that objective surgeon-/ therapist-measured outcome (range of motion) has a significant correlation with subjective patient-reported outcomes (OKS). Hence, both outcome measures should be employed in the postoperative monitoring of patient progress. Level of evidence Prospective case series, Level IV. Keywords Total knee arthroplasty · Range of motion · Recovery plateau
Introduction Knee range of motion is an important outcome of total knee arthroplasty (TKA). It has been documented that 67° of flexion is required for swing phase in gait, 83° is required for stairs climbing, 90° is required to go downstairs, and 93° of flexion is required to rise from a seated position [1]. It has been reported that patients with a limited preoperative knee flexion angle significantly improved after total knee arthroplasty while patients with a good preoperative knee flexion angle had limited improvements or had a postoperative flexion less than the preoperative flexion angle. On the other hand, it has been shown that preoperatively stiff knees were likely to have a limited postoperative knee flexion angle [5]. It is essential to address the expectation of patients contemplating TKA. Patient dissatisfaction following TKA may be as high as 15–20 % [16]. With an aging population that is staying active after retirement age, there is an increasing expectation for improvement after TKA. Among various reasons for patient dissatisfaction, inadequate preoperative counseling could be one of the contributing factors. To that effect, information regarding the time course of recovery from TKA allows patients to have realistic expectations about their progress.
13
There is no consensus regarding the time course of improvement in knee range of motion following TKA. The primary aim of this study was to identify the time point at which improvements in the knee range of motion reach a plateau, if any. The secondary aim of this study was to investigate the correlation between the improvements in knee range of motion and the patient-reported outcomes (Oxford knee score and SF-36). The hypothesis is that there is a time point at which the recovery in the knee range of motion after TKA plateaus.
Materials and methods A prospective study of patients who underwent TKA at a large regional hospital was conducted. Patients who underwent both unilateral and bilateral primary TKA for osteoarthritis were included in this study. Patients who underwent revision TKA, who had a history of rheumatoid arthritis, and who had septic arthritis were excluded from this study. All operative procedures were performed by the same surgeon between 2007 and 2009. Cruciate-retaining implants were used in 77 patients, and posterior-stabilized implants were used in 68 patients. All patients underwent the same postoperative rehabilitation protocol. Knee range of extension and flexion was measured preoperatively and at 1, 3, 6, 12, and 24 months. Measurement of knee range of motion was carried out using goniometry, accurate up to 0.1°. The landmarks used in the measurements are the greater trochanter of the femur, the proximal head of the fibula, and the lateral malleolus. Goniometry was used as it has been reported that goniometric measurements of range of motion are more reliable than visual observation [8]. All measurements were carried out by a single trained physical therapist to eliminate inter-observer variability. In addition, patients were scored in the OKS and SF36 preoperatively and at 6, 12, and 24 months postoperatively. The same physical therapist administered OKS and SF-36 scores. The OKS consists of 12 questions, which are summed to give a total score. The minimum score is 12 and the maximum score is 60. A lower score corresponds to better outcome [12]. The SF-36 physical (PCS) and mental (MCS) component summary scores were computed. A higher score corresponds to a better outcome [18]. Approval for this study was given by SingHealth Centralized Institutional Review Board (CIRB/2012/2097/D). Statistical analysis Statistical analysis was carried out in consultation with an in-house biostatistician, using Stata 11 (StataCorp. 2009. Stata Statistical Software: Release 11. College Station, TX: StataCorp LP). Specifically, the generalized estimating
13
Knee Surg Sports Traumatol Arthrosc
equation (GEE) model was used to analyze data. Pair-wise comparison with Bonferroni’s correction was performed to assess whether there were differences in means between adjacent time points. Differences were considered to be statistically significant if p value was
