Comparison of range of motion after standard and high-flexion posterior stabilised total knee replacement

Abstract

The purpose of this study was to compare the range of motion after standard version posterior stabilised TKR and high-flexion version TKR in patients receiving bilateral total knee replacement. Thirty-five patients were recruited. The range of motion of the knees was measured clinically with a goniometer in both the pre-operative period and the most recent follow-up. It was found that the preoperative range of motion was comparable in the two groups. The average post-operative flexion was 105°±13°in the standard version group and 106°±14°in the high-flexion design group (p=0.201, paired t-test; beta error=0.073). A slight loss in flexion was observed in the standard version group (0.5°) as opposed to a slight gain in the high-flexion design group (2°). However, this was not statistically significant (p=0.251, paired t-test; beta error=0.105).Résumé Le but de cette étude est de comparer la mobilité du genou après prothèse totale postéro stabilisée et prothèse total type « high-flexion », tous les patients étant opérés des deux genoux dans le même temps opératoire. 35 patients ont été inclus, la mobilité des genoux a été mesurée cliniquement en pré-opératoire et au plus grand recul. La mobilité pré-opératoire a été comparable dans les deux groupes, la mobilité post opératoire a été de 105°±13°dans la prothèse standard contre 106°±14°dans les prothèses dites « high-flexion » (p=0.201). Une petite perte de flexion est observée dans le groupe standard (0.5°), le gain dans le groupe des prothèses dites « high-flexion » est modéré (2°). Il n'y a pas de différences significatives entre ces deux groupes (p=0.251).

Range of motion and function are similar in patients undergoing TKA with posterior stabilised and high-flexion inserts

“…Our study and five others in the literature [14,20,22,27,29] failed to prove an increase in flexion with the use of HF TKAs. However, there is evidence that suggests that HF TKA designs may improve intraoperative passive ROM and postoperative maximum weight-bearing flexion.…”

“…In a systematic literature review focusing on outcomes after HF TKA, Murphy et al found that there was insufficient evidence to support the view that these new TKA designs improved ROM or functional performance [24]. This review included nine studies [1, 8,10,14,17,27,29,34,37] with 399 HF TKAs in 370 patients. They conclude that the claims of greater flexion, ROM, and function for HF TKA reported in some of those studies were not supported due to poor study designs, short follow-up periods, inadequate blinding, and use of functional outcome measures that lacked sensitivity [24].…”

“…The design changes aim at facilitating flexion by improving the TKA kinematics in high flexion. It remains debatable whether the design changes in the so called HF TKA will not only facilitate but also increase postoperative flexion and diminish the manipulation rate [1, 8,10,14,17,18,22,27,29,37].…”

High-flexion total knee arthroplasty: a systematic review

“…Osteoarthritis was the primary reason for TKA. Five of the nine studies were conducted in Asian populations reflecting the increased knee flexion demands in this region's cultural and religious activities [24][25][26][27][28].…”

2009 Marshall Urist Young Investigator Award: How Often Do Patients with High-Flex Total Knee Arthroplasty Use High Flexion?

“…A third study reported no difference in average postoperative knee flexion in 50 patients who underwent bilateral TKAs (138°for NexGen 1 LPS-Flex versus 135°for NexGen 1 LPS) [26]. To date, three of nine clinical studies suggest patients have increased postoperative flexion with highflexion prostheses [6,19,20,23,26,38,42,44,45]. One of these studies reported patients with maximum flexion greater than 135°had a better functional WOMAC Osteoarthritis Index score than patients with maximum flexion of 135°or less (17.5 versus 14.3) [45].…”