Meijer, M.F. (2012) Inter- and intraobserver reliability of the EOS stereography system for the follow-up after revision total knee arthroplasty. thesis, Medicine.
Full text available on request.Abstract
Introduction: Primary total knee arthroplasty (TKA) is a safe and cost-effective treatment for end-stage knee osteoarthritis and the incidence of this surgical procedure has increased rapidly over the past two decades. Despite good results of primary TKA, the number of revision total knee arthroplasties (rTKAs) also increases and a further increase is predicted. Compared to primary TKA rTKA is a more complex surgical procedure and results in worse clinical outcome. Proper positioning of the implant is very important, since malpositioning of a knee prosthesis leads to worse patient outcome and survival. During primary TKA, one uses anatomic landmarks to correctly implant the prosthesis. Due to extensive bone loss during rTKA, these anatomical landmarks have disappeared and correct alignment of the prosthesis is therefore a challenge. However, for radiological evaluation of prosthesis alignment a new biplanar low-dose X-ray technique, called the EOS stereography system is available. With this device it is possible to obtain weight-bearing 2D and 3D images of the leg with an amount of radiation 800-1000 times less than for CT-scan and 10 times less than for conventional X-ray. However, inter- and intraobserver reliability of the EOS system has not yet been investigated. Objective of this study is therefore to investigate inter- and intraobserver reliability of knee prosthesis alignment measurements after rTKA using the EOS system. Materials and methods: In this study 40 anteroposterior and lateral EOS images of 37 rTKA patients were included. Two observers independently performed 2D and 3D measurements on these 40 images two times. Measurements chosen for this study are varus/valgus angle and flessum/recurvatum angle. Intraclass Correlation Coefficients were used for determining relative reliability and were interpreted using the benchmarks described by Fleiss. The Bland and Altman method was used for determining absolute reliability. Results: Interobserver reliability is excellent for varus/valgus angle in 3D (VV3D), flessum/recurvatum angle in 3D (FR3D), varus/valgus angle in 2D (VV2D) and flessum/recurvatum angle in 2D (FR2D), with ICCs > 0.95. There are no significant differences between the measurements of observer A and observer B. There is no bias between the measurements of VV3D of both observers. For FR3D, VV2D and FR2D a bias of respectively 0.88° (0.76 -1.00), -0.16° (-0.31 – - 0.01), 0.85° (0.74 – 0.96) exists between the two observers. Intraobserver reliability is excellent for VV3D, FR3D, VV2D and FR2D with ICCs > 0.97. There is no significant difference and no bias between the means of the first and second measurements of all angles. Discussion and conclusion: Although a bias does exist regarding interobserver reliability when measuring FR3D, VV2D and FR2D, this is small and not considered of clinical importance. It can be concluded that the EOS biplanar low dose X-ray device provides reliable varus/valgus and flessum/recurvatum measurements of the lower limb in 2D and 3D when containing a knee prosthesis.
| Item Type: | Thesis (Thesis) |
|---|---|
| Supervisor name: | Facultair begeleider: and Boerboom drs. A.L. and Afdeling: and Orthopaedie, UMCG |
| Faculty: | Medical Sciences |
| Date Deposited: | 25 Jun 2020 10:54 |
| Last Modified: | 25 Jun 2020 10:54 |
| URI: | https://umcg.studenttheses.ub.rug.nl/id/eprint/1523 |
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