A residual intra-articular varus after medial opening wedge high tibial osteotomy (HTO) for varus osteoarthritis of the knee.
Arch Orthop Trauma Surg
; 139(6): 743-750, 2019 Jun.
Article
em En
| MEDLINE
| ID: mdl-30673869
ABSTRACT
PURPOSE:
Varus deformity of knee osteoarthritis was formed by both intra-articular and extra-articular pathologies. Such intra-articular deformities could not be fully corrected by a medial open-wedge high tibial osteotomy (HTO), which was performed as an extra-articular procedure. Therefore, the purpose of this study was to investigate whether any residual varus was left inside the joint after HTO in the patients with knee osteoarthritis, and a correlation of the residual varus could be traced.METHODS:
This study involved 66 patients (66 knees) undergoing HTO for medial knee osteoarthritis. The percentage of mechanical axis (%MA), mechanical femorotibial angle (mFTA), mechanical lateral distal femoral angle (mLDFA), mechanical medial proximal tibial angle (mMPTA) and joint line convergence angle (JLCA) were measured on radiographs of the full-length legs preoperatively and 6 months postoperatively. The relationship between changes in the JLCA and alignment correction was assessed. The postoperative residual JLCA was categorized as the optimal (postoperative JLCA ≤ 2°), the acceptable (2° < postoperative JLCA ≤ 5°), and the unacceptable (postoperative JLCA > 5°) to analyze its correlation with pre- or intra-operative factors.RESULTS:
Average %MA and mFTA were improved from 5.5 to 60% and from 190.2° to 176.4°, respectively. There was no change in mLDFA, whereas mMPTA changed from 80.3° to 91.8°. JLCA changed from 4.2° to 2.7°. The analyses of multiple linear regression showed that the preoperative JLCA and postoperative changes in mechanical alignment (%MA, mFTA and mMPTA) were two important variables dependently associated with differences in JLCAs postoperatively. However, postoperative JLCAs showed a stronger correlation to preoperative JLCAs than to changes in mechanical alignment postoperatively. A Chi-square analysis showed a significantly higher percentage of patients achieved acceptable postoperative JLCAs in the preoperative JLCA ≤ 6° group (78.8%) compared to the preoperative JLCA > 6° group (6.1%). Therefore, 6° of JLCA was suggested to be a tipping point.CONCLUSIONS:
The capability of HTO to correct intra-articular varus deformities, which was represented by JLCAs, is limited. Postoperative residual JLCAs were correlated primarily to preoperative JLCA values and total alignment correction, while the former accounted for most. A preoperative JLCA of 6° was suggested to be a tipping point, and a larger value indicated more than 5° residual JLCA after the HTO.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Temas:
Geral
Base de dados:
MEDLINE
Assunto principal:
Osteotomia
/
Tíbia
/
Osteoartrite do Joelho
Tipo de estudo:
Etiology_studies
/
Incidence_studies
/
Observational_studies
/
Risk_factors_studies
Limite:
Humans
Idioma:
En
Revista:
Arch Orthop Trauma Surg
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
China