Investigation of body weight ratios on joint structures at different knee flexion angles in patients with unilateral knee arthroplasty
Serkan Bakırhan1, Bayram Ünver2, Vasfi Karatosun3
1İzmir Üniversitesi Sağlık Yüksekokulu, Fizyoterapi ve Rehabilitasyon Bölümü, İzmir, Türkiye
2Dokuz Eylül Üniversitesi Fizik Tedavi ve Rehabilitasyon Yüksekokulu, Ortopedik Fizyoterapi Anabilim Dalı, İzmir, Türkiye
3Dokuz Eylül Üniversitesi Tıp Fakültesi, Ortopedi ve Travmatoloji Anabilim Dalı, İzmir, Türkiye
Keywords: Age factors; arthroplasty; body weight; knee; replacement.
Abstract
Objectives: The study aims to determine body weight ratios between extremities in patients with unilateral total knee arthroplasty (TKA) at 12 months postoperatively at the staticstanding position at 30, 60 and 90 degrees of knee flexion.
Patients and methods: The study included 52 female patients (mean age 65.6±10.6 years; range 40 to 83 years) who underwent unilateral primary TKA. The force-platform was used to calculate the body-weight ratios of the patients. Body weight ratios on the operated and non-operated limbs of the unilateral TKA patients were examined at standing-static position at 30, 60 and 90 degrees of knee flexion on the forceplatform according to their age and body mass index (BMI). The pain levels of the patients were evaluated using the visual analog scale.
Results: It was found that unilateral TKA patients placed their body weight on the non-operated limb more at the standing-static position, and 30, 60 and 90 degrees of knee flexion at 12 months postoperatively (p<0.05). It was also found that as the knee flexion degree increased with age, so did TKA patients place their body weight on the nonoperated limb more (p<0.05), and that BMI had no effect on the load distribution difference over the two extremities (p>0.05).
Conclusion: During the postoperative period, load asymmetry between the two extremities in patients with unilateral TKA remains the same due to advancing age. This accelerates the osteoarthritis process on the nonoperated knee. It is concluded that the age factor should be taken into account while planning physiotherapy and rehabilitation programs for unilateral TKA patients and knee exercise programs aiming to place load over the operated limb should be arranged.