Posterolateral overhang affects patient quality of life after total knee arthroplasty
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To investigate the appropriate mediolateral placement of symmetrical tibial components and the amount of overhang expected from the posterolateral of tibial components implanted to give ideal coverage and the subsequent incidence of residual knee pain and reduction in functional capacity.
A retrospective evaluation was made of 146 consecutive total knee arthroplasties. The posterolateral overhang, rotational alignment and coverage of the tibial component were measured on a post-operative CT scan and the effect of posterolateral overhang on clinical outcomes was analysed 3 years after surgery.
Complaints of local pain in the posterolateral corner were determined in 76 (52.1%) patients. At the Posterolateral corner, overhang was determined in 111 (76%) patients, in the cortical border in 11 (7.6%) patients and underhang in 24 (16.4%) patients. In 71 (48.6%) patients, pain was determined together with oversize and in the evaluation of the overhang of the tibial component in the posterolateral region and the rotation status, there was determined to be overhang in 75 (96.2%) patients where the tibial component was placed in ideal rotation, in 25 (100%) where placement was in external rotation and in 11 (25.6%) where placement was in internal rotation. The mean KSS, KSS-F and WOMAC-P scores were 83.9 ± 6.3, 83.3 ± 7.8 and 4.6 ± 2.9, respectively, in those with posterolateral overhang of the tibial component .The mean KSS, KSS-F and WOMAC-P scores were 86.6 ± 8.4, 89.5 ± 7.8 and 2.8 ± 2.1, respectively, in those with no overhang and the difference was determined to be statistically significant. The amount of overhang was determined as mean 3.6 ± 2.0 mm in those with posterolateral pain and 0.02 ± 3.4 mm in those without pain and the difference was statistically significant.
This study demonstrated that overhang in the posterolateral region is surprisingly high and negatively affects the clinical results following TKA, thereby presenting a danger to the success of TKA. The risk of posterolateral oversizing can increase with placement of the tibial component in external rotation.
KeywordsKnee arthroplasty Posterolateral overhang Tibial baseplate Knee pain
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
There is no funding source.
This article does not contain any studies with human participants or animals performed by any of the authors.
Informed consent was obtained from all individual participants included in the study.
- 4.Bonnin M et al (2000) Revision in non-infected total knee arthroplasty: an analysis of 69 consecutive cases. Rev Chir Orthop Repar Appar Mot 86(7):694–706Google Scholar
- 9.Insall JN, Dorr LD, Scott RD, Scott WN (1989) Rationale of the Knee Society clinical rating system. Clin Orthop Relat Res 248:13–14Google Scholar
- 11.Berger RA et al (1993) Determining the rotational alignment of the femoral component in total knee arthroplasty using the epicondylar axis. Clin Orthop Relat Res 286:40–7Google Scholar
- 15.Yang B et al (2012) Sex, age, and annual incidence of primary total knee arthroplasty: a university affiliated hospital survey of 3118 Chinese patients. Chin Med J (Engl) 125(22):3952–3955Google Scholar
- 18.Incavo SJ et al (1994) Tibial plateau coverage in total knee arthroplasty. Clin Orthop Relat Res 299:81–5Google Scholar
- 34.Hirakawa MKM, Tomari K, Higuma Y, Ikeda S, Noguchi T, Tsumura H (2013) Posterolateral overhang of the femoral component in total knee arthroplasty. B Jt J 95-B(SUPP 15):197Google Scholar