No Difference in 2-Year Functional Outcomes Using Kinematic Versus Mechanical Alignment in TKA: A Randomized Controlled Clinical Trial

Abstract

underwent primary TKA through the KA or MA technique were included. Results: Six studies were included in the meta-analysis. The proportion of patients who developed postoperative complications (OR 1.10, 95% CI: 0.49 to 2.46; P¼0.69) did not differ significantly between the KA and MA techniques. The two groups were also similar in terms of change in hemoglobin (95% CI:-0.38 to 0.34; P¼0.91), length of hospital stay (95% CI:-0.04 to 0.55; P¼0.10), hip-knee-ankle angle (95% CI:-1.76 to 0.75; P¼0.43), joint line orientation angle (95% CI:-4.27 to 4.23; P¼0.99), tibial component slope (95% CI:-0.53 to 3.56; P¼0.15), and femoral component flexion (95% CI:-2.61 to 7.57; P¼0.34). In contrast, operation time (95% CI:-27.16 to-3.71; P¼0.01), overall functional outcome (95% CI: 6.59 to 11.51; P<0.0001), knee anatomical axis (95% CI:-1.38 to-0.01; P¼0.05), femoral component relative to the mechanical axis (95% CI:-2.47 to-1.40; P<0.0001), and tibial component relative to the mechanical axis (95% CI: 1.56 to 2.95; P<0.0001) were significantly different between the two groups. Conclusion: There were no significant differences in postoperative complications, change in hemoglobin, length of hospital stay, hip-knee-ankle angle, joint line orientation angle, tibial component slope, or femoral component flexion between the KA and MA techniques for primary TKA. However, the KA technique resulted in a significantly shorter operation time and better overall functional outcome than the MA technique, even though the femoral component was placed slightly more valgus and the tibial component slightly more varus relative to the mechanical axis with the KA technique.

Leaving Residual Varus Alignment After Total Knee Arthroplasty Does Not Improve Patient Outcomes

“…Two studies comparing clinical and functional outcomes in postoperatively neutrally-aligned and varus knees have reported worse outcomes in the latter group; [1,40] two have reported superior outcomes in patients left in residual varus; [26,41] and five have reported no differences in outcomes in postoperatively neutrally-aligned and varus knees. [27,36,[42][43][44] Collectively therefore, evidence to date reflects two in favor and seven against the idea that residual varus alignment may improve clinical and functional outcomes and subsequent satisfaction with TKA.…”

No Benefit of Computer-assisted TKA: 10-year Results of a Prospective Randomized Study

“…More recently, questions have been raised as to whether these targets should shift to achieve more patient-specific alignment goals, restoring the individual's premorbid alignment and thus restoring knee kinematics [13,21]. We might have chosen the wrong target in our series; however, to date no scientific evidence of a better "systematic option" has been demonstrated [27]. With the numbers available, we found no survivorship advantage in patients treated with CAS TKA 10 years after surgery.…”

“…More specific targets of alignment may be required and several new concepts have emerged recently such as kinematic alignment or constitutional alignment [1,2]. These techniques are too recent to have long-term survivorship; and if some clinical improvements have been shown at midterm followup [13], a recent randomized controlled study failed to demonstrate any clinical benefit of the kinematic alignment concept 2 years after TKA [27].…”

Reproducibility of an Intraoperative Pressure Sensor in Total Knee Replacement

“…Surgeons have been shown to be poor predictors of the true state of balance and over-tensioning of soft tissue is believed to be a significant cause of worse outcomes in TKR [7,8]. Techniques such as kinematic alignment and gap balancing methods are centered around the concept that these methods will optimize knee ligament balance and prevent over-tensioning, which will directly improve patient outcomes [9][10][11]. Poor soft tissue balance may present as either instability of the prosthesis (insufficient tension) or stiffness and pain (over-tension), both of which are recognized causes of revision knee surgery [12].…”