Computer Navigation-assisted versus Minimally Invasive TKA

Abstract

Computer-navigated and minimally invasive TKAs are emerging technologies that have distinct strengths and weaknesses. We compared duration of surgery, length of hospitalization, Knee Society scores, radiographic alignments, and complications in two unselected groups of 81 consecutive knees that underwent TKA using either a minimally invasive approach or computer navigation. The two groups were operated on by two different surgeons over differing timeframes. The mean surgical time was longer in the navigated group by 63 minutes. The Knee Society scores and lengths of hospitalization of the two groups were similar. The postoperative component alignments of the two groups were similar; the mean femoral valgus and tibial varus angles of the navigation group changed from 96°and 88°p reoperatively to 95°and 89°postoperatively, respectively, and in the minimally invasive group, the mean femoral valgus angles and tibial varus angles changed from 97°and 88°preoperatively to 95°and 89°postoperatively, respectively. There were 11 major and three minor complications in the navigation group, including one revision, two femoral shaft fractures, four reoperations for knee stiffness, and four instances of bleeding from tracker sites. We believe the higher incidence of complications in addition to the longer operative time in the navigated group may outweigh any potential radiographic benefits. Level of Evidence: Level II, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Residual Varus Alignment does not Compromise Results of TKAs in Patients with Preoperative Varus

“…Physical examination included evaluation of knee ROM, stability to varus and valgus stress, and wound healing, and the IKS knee and function scores were calculated [11]. We grouped perioperative complications as major (those threatening life or requiring reoperation) and minor (those resolving with antibiotics, anticoagulation, or without specific treatment) as described previously [4,25].…”

Does Minimally Invasive Surgery Improve Short-term Recovery in Total Knee Arthroplasty?

“…Repeated prudent examination of the position of instruments and cut surface is important to avoid outliers. Computer-assisted navigation systems are promising for increasing the precision of implanting prostheses during TKAs, but the navigation procedure further extends surgery time [3,5,6,12,42].…”

“…We specifically asked whether MIS TKAs would be associated with (1) increased operative time, (2) reduced blood loss, (3) shortened hospital stay, (4) faster recovery of ROM, (5) higher knee scores, (6) inferior component positioning, and (7) increased complications.…”

Improved Accuracy of Alignment With Patient-specific Positioning Guides Compared With Manual Instrumentation in TKA

“…Although computer-assisted navigation (CAN) reduces the number of outliers by approximately threefold (Table 1), it requires additional operative time compared to MI [11] and may increase the rate of complications, such as postoperative stress fracture [10,55]. PSPGs purportedly eliminate many of the disadvantages of CAN, including surgical prolongation and fiducial pin complications [33,81], while enabling individualized bone resections that match the measured mechanical axis.…”