Similar migration in computer-assisted and conventional total knee arthroplasty

Abstract

Background and purposeComputer-assisted surgery (CAS) in total knee arthroplasty (TKA) has been used in recent years in the hope of improving the alignment and positioning of the implant, thereby achieving a better functional outcome and durability. However, the role of computer navigation in TKA is still under debate. We used radiostereometric analysis (RSA) in a randomized controlled trial (RCT) to determine whether there are any differences in migration of the tibial component between CAS- and conventionally (CONV-) operated TKA.Patients and methods54 patients (CAS, n = 26; CONV, n = 28) with a mean age of 67 (56–78) years and with osteoarthritis or arthritic disease of the knee were recruited from 4 hospitals during the period 2009–2011. To estimate the mechanical stability of the tibial component, the patients were examined with RSA up to 24 months after operation. The following parameters representing tibial component micromotion were measured: 3-D vector of the prosthetic marker that moved the most, representing the magnitude of migration (maximum total point motion, MTPM); the largest negative value for y-translation (subsidence); the largest positive y-translation (lift-off); and prosthetic rotations. The precision of the RSA measurements was evaluated and migration in the 2 groups was compared.ResultsBoth groups had most migration within the first 3 months, but there was no statistically significant difference in the magnitude of the migration between the CAS group and the CONV group. From 3 to 24 months, the MTPM (in mm) was 0.058 and 0.103 (p = 0.1) for the CAS and CON groups, respectively, and the subsidence (in mm) was 0.005 and 0.011 (p = 0.3).InterpretationMean MTPM, subsidence, lift-off, and rotational movement of tibial trays were similar in CAS- and CONV-operated knees.

Long-term outcomes were similar between hybrid and cemented TKAs performed on paired knees at a minimum 15 years of follow-up

“…There has been controversy as to whether the long‐term survival of hybrid TKAs is better than that of cemented TKAs due to biologic durable cementless fixation of the femoral component. In Norwegian registries, the survival of hybrid TKAs was better than that of cemented TKAs at 11 years of follow‐up [23]. A long‐term retrospective study with a minimum 15 years of follow‐up showed a better survival rate for aseptic loosening in hybrid TKAs compared with cemented TKAs [23].…”

Letter to the Editor: How Large a Study is Needed to Detect TKA Revision Rate Reductions Attributable to Robotic or Navigated Technologies? A Simulation-based Power Analysis

“…A meta-analysis by Rhee et al [6] using nine RCTs with long-term follow-up confirmed this assumption by finding no differences in functional outcomes and survivorship between CAS and conventional TKA [6]. The findings of these RSA-based studies [4,9] are supportive of the main findings of Hickey et al [1] in that they suggest there is likely to be little, if any, clinical benefit from robotic surgery in terms of the clinically important endpoint of tibial revision.…”

“…To our knowledge, two randomized controlled trials (RCTs) [4,9] on computer-assisted surgery (CAS) in TKA used RSA to measure tibial baseplate migration. van Strien et al [9] and Petursson et al [4] studied the effect on tibial baseplate migration 2 years after surgery randomizing 57 and 54 patients, respectively. They found no clinically relevant differences in tibial migration.…”

Tech-trends in orthopedics 2018

“…An interesting randomized controlled trial from Petursson et al. (2017) showed no benefit in regard to RSA migration patterns, i.e. no signs of improved implant survival despite better positioning.…”