Range of Motion in Total Knee Arthroplasty: A Prospective Comparison of High-Flexion and Standard Cruciate-Retaining Designs

Abstract

For knees managed with a cruciate-retaining total knee arthroplasty, those that had the high-flexion design and those that had the standard design were found to have a similar range of motion under both non-weight-bearing and weight-bearing conditions. Moreover, no significant difference was found in terms of the other functional outcomes examined.

Can a High-flexion Total Knee Arthroplasty Relieve Pain and Restore Function Without Premature Failure?

“…Similar high knee scores and functional improvements were observed in other short-term evaluations of other HF-TKAs [18,19,32] (Table 5). The high mean postoperative knee flexion observed in our report (129°) was similarly observed in other reports of various HF-TKA designs [1,4,11,13,15,18,19,32] ( Table 5). Many of these reports involved patients of Asian heritage who often had higher magnitudes of preoperative flexion than customarily observed in Western cultures.…”

“…Some observed similar degrees of maximal knee flexion [18,22,28,32], while others demonstrated superior flexion was obtained using a HF-TKA [1,4,11,15]. The amount of increase in flexion in studies reporting superior flexion with a HF-TKA design was typically limited (5°-10°).…”

“…A myriad of HF-TKA prosthetic designs have recently been introduced with the goal of increasing the magnitude of flexion obtained after TKA [1,4,11,12,15,18,19,22,25,28,32]. As with introduction of any new medical device, clinical evaluation of its performance and any associated adverse events is critical.…”

“…Numerous comparative reports comparing patients implanted with a HF-TKA versus a conventional TKA using the same implant system have been published [1,4,11,15,18,22,28,32]. Some observed similar degrees of maximal knee flexion [18,22,28,32], while others demonstrated superior flexion was obtained using a HF-TKA [1,4,11,15].…”

“…Several factors affect postoperative flexion after TKA, including preoperative (preoperative flexion, body habitus, presence of previous knee surgery [13,20,30,34]), intraoperative (ligament and gap balance, component size and position, removal of osteophytes, extensor mechanism tension and balance [10,20,21,24]), and postoperative (postoperative rehabilitation [34], postoperative complications) factors. More recently, the effect of prosthesis design on postoperative knee flexion has been of interest, resulting in development of numerous high-flexion TKA (HF-TKA) implants [1,4,11,12,15,18,19,22,25,28,32]. Early reports of patients implanted with these devices demonstrated differing data, with some reporting enhanced knee flexion and others demonstrating flexion magnitudes similar to traditional ''non-high-flexion'' TKA implants [1,15,18,19].…”