The Chitranjan S. Ranawat Award : No Difference in 2-year Functional Outcomes Using Kinematic versus Mechanical Alignment in TKA: A Randomized Controlled Clinical Trial.

Show simple item record Young, Simon en Walker, Matthew L en Bayan, Ali en Briant-Evans, Toby en Pavlou, Paul en Farrington, Bill en 2018-11-05T23:19:15Z en 2017-01 en
dc.identifier.issn 0009-921X en
dc.identifier.uri en
dc.description.abstract Neutral mechanical alignment (MA) in total knee arthroplasty (TKA) aims to position femoral and tibial components perpendicular to the mechanical axis of the limb. In contrast, kinematic alignment (KA) attempts to match implant position to the prearthritic anatomy of the individual patient with the aim of improving functional outcome. However, comparative data between the two techniques are lacking.In this randomized trial, we asked: (1) Are 2-year patient-reported outcome scores enhanced in patients with KA compared with an MA technique? (2) How does postoperative component alignment differ between the techniques? (3) Is the proportion of patients undergoing reoperation at 2 years different between the techniques?Ninety-nine primary TKAs in 95 patients were randomized to either MA (n = 50) or KA (n = 49) groups. A pilot study of 20 TKAs was performed before this trial using the same patient-specific guides positioning in kinematic alignment. In the KA group, patient-specific cutting blocks were manufactured using individual preoperative MRI data. In the MA group, computer navigation was used to ensure neutral mechanical alignment accuracy. Postoperative alignment was assessed with CT scan, and functional scores (including the Oxford Knee Score, WOMAC, and the Forgotten Joint Score) were assessed preoperatively and at 6 weeks, 6 months, and 1 and 2 years postoperatively. No patients were lost to followup. We set sample size at a minimum of 45 patients per treatment arm based on a 5-point improvement in the mean Oxford Knee Score (OKS; the previously reported minimum clinically significant difference for the OKS in TKA), a pooled SD of 8.3, 80% power, and a two-sided significance level of 5%.We observed no difference in 2-year change scores (postoperative minus preoperative score) in KA versus MA patients for the OKS (mean 21, SD 8 versus 20, SD 8, least square means 1.0, 95% confidence interval [CI], -1.4 to 3.4, p = 0.4), WOMAC score (mean 38, SD 18 versus 35, SD 8, least square means 3, 95% CI, -3.2 to 8.9, p = 0.3), or Forgotten Joint score (28 SD 37 versus 28, SD 28, least square means 0.8, 95% CI, -9.1-10.7, p = 0.8). Postoperative hip-knee-ankle axis was not different between groups (mean KA 0.4° varus SD 3.5 versus MA 0.7° varus SD 2.0), but in the KA group, the tibial component was a mean 1.9° more varus than the MA group (95% CI, 0.8°-3.0°, p = 0.003) and the femoral component in 1.6° more valgus (95% CI, -2.5° to -0.7°, p = 0.003). Complication rates were not different between groups.We found no difference in 2-year patient-reported outcome scores in TKAs implanted using the KA versus an MA technique. The theoretical advantages of improved pain and function that form the basis of the design rationale of KA were not observed in this study. Currently, it is unknown whether the alterations in component alignment seen with KA will compromise long-term survivorship of TKA. In this study, we were unable to demonstrate an advantage to KA in terms of pain or function that would justify this risk.Level I, therapeutic study. en
dc.format.medium Print en
dc.language eng en
dc.relation.ispartofseries Clinical orthopaedics and related research en
dc.rights Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. Previously published items are made available in accordance with the copyright policy of the publisher. en
dc.rights.uri en
dc.subject Knee Joint en
dc.subject Humans en
dc.subject Range of Motion, Articular en
dc.subject Treatment Outcome en
dc.subject Arthroplasty, Replacement, Knee en
dc.subject Pilot Projects en
dc.subject Knee Prosthesis en
dc.subject Recovery of Function en
dc.subject Aged en
dc.subject Aged, 80 and over en
dc.subject Middle Aged en
dc.subject Female en
dc.subject Male en
dc.subject Biomechanical Phenomena en
dc.subject Patient Reported Outcome Measures en
dc.title The Chitranjan S. Ranawat Award : No Difference in 2-year Functional Outcomes Using Kinematic versus Mechanical Alignment in TKA: A Randomized Controlled Clinical Trial. en
dc.type Journal Article en
dc.identifier.doi 10.1007/s11999-016-4844-x en
pubs.issue 1 en
pubs.begin-page 9 en
pubs.volume 475 en
dc.rights.holder Copyright: The author en
dc.identifier.pmid 27113595 en
pubs.end-page 20 en
pubs.publication-status Published en
dc.rights.accessrights en
pubs.subtype research-article en
pubs.subtype Randomized Controlled Trial en
pubs.subtype Journal Article en
pubs.elements-id 527126 en Medical and Health Sciences en School of Medicine en Surgery Department en
dc.identifier.eissn 1528-1132 en
pubs.record-created-at-source-date 2016-04-27 en
pubs.dimensions-id 27113595 en

Files in this item

There are no files associated with this item.

Find Full text

This item appears in the following Collection(s)

Show simple item record


Search ResearchSpace