High-flexion TKA in patients with a minimum of 120 degrees of pre-operative knee flexion: outcomes at six years of follow-up

Abstract

We prospectively evaluated outcomes of highflexion total knee arthroplasty in 165 patients who had advanced arthritis with a minimum 120-degree pre-operative knee flexion, with a mean follow-up of 77 months. Patients were divided into two groups according to their ability to perform full-range (heel-to-buttock) pre-operative knee flexion (group A) and the inability to do so (group B). The overall clinical rating was "excellent" in 96% of patients and "good" in 4% of patients. Mean maximum knee flexion decreased from 137.9°to 134.8°, with no statistical difference between pre-and post-operative knee flexion. However, patients in group A had significantly decreased knee flexion (146.2°vs. 135.0°, p<0.001), whereas patients in group B exhibited no change in knee flexion (133.7°vs. 134.7°, p=0.14). We found that 14.7%, 36.5% and 43.0% of the studied patients could engage in kneeling, Thai polite style sitting and cross-legged sitting, respectively, with no significant differences between groups A and B. The survival rates for any reoperation and prosthesis-related problem (such as early loosening) at six years were 98.3% and 100%, respectively. At six-year follow-up in patients with well preserved pre-operative knee flexion, the highflexion knee prosthesis provided a favourable outcome without improving knee flexion.

High-flexion Prosthesis Improves Function of TKA in Asian Patients Without Decreasing Early Survivorship

“…The results of this study support several others reporting no or few loosening cases with the same HF prostheses [18,25,26,39,40,43,50] (Table 3). The present study extends these findings to a larger population with the same ethnicity than previous studies involving a small number of cases to address whether early femoral loosening of a HF design is really high.…”

“…However, our cohort of Korean patients had conflicting findings in that the patients who could achieve postoperative deep flexion did not have inferior cumulative survival than those who had postoperative flexion less than 135°. Other clinical trials conducted in an Asian population reported a better survivorship with none or just one aseptic failure despite the higher postoperative flexion of 135°to 140° [18,20,25,26,43,45] than ours.…”

“…They suggested that these implants allowed HF activity such as squatting or kneeling but which might be associated with a marked rate of early loosening of the femoral component. In contrast, other studies involving HF TKA have reported conflicting prevalences of early aseptic loosening even in the same ethnic group [18,25,26,39,40,43,50]. We therefore determined (1) how many patients could achieve HF ability postoperatively; (2) whether the rate of aseptic loosening was high after HF TKA; and (3) whether the survivorship was inferior in patients who achieved postoperative deep knee flexion more than 135°in our cohort of a Korean population.…”

Gap changes after popliteus-tendon resection in PS-TKA: A cadaveric study in Thai female knees

“…A previous analysis of patient demographic data [10] revealed that a greater number of females than males and the anatomical profile of the distal femur [11] indicated that the average medio-lateral and antero-posterior dimensions of the distal femur of female patients was smaller than what was observed in male patients. Based on that data, we conducted a study on Thai female cadavers, as females represent the most common subgroup of TKA patients.…”

Is the effect of a posterior cruciate ligament resection in total knee arthroplasty predictable?

“…In recent years, demand has increased for TKA to achieve deeper flexion, e.g. for kneeling or squatting [5][6][7]. It is generally agreed that the success of TKA depends on equally balanced extension and flexion gaps [8,9].…”