RESUMEN

BACKGROUND: Few clinical studies have reported the predictors of lateral hinge fracture (LHF) after medial opening-wedge high tibial osteotomy (MOWHTO). PURPOSE/HYPOTHESIS: The purpose was to compare the incidence of LHF on plain radiographs versus computed tomography (CT) scans and to investigate the factors related to the development of LHF after MOWHTO. We hypothesized that (1) a higher LHF detection rate would be seen on CT scans versus plain radiographs and (2) LHF incidence would be related to opening gap width and hinge position. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 3. METHODS: A total of 97 MOWHTO cases were included. The presence and types of LHF were determined from plain radiographs and CT scans. Radiographic parameters were measured on plain radiographs taken 6 weeks postoperatively. Anterior and posterior opening gap widths, coronal and sagittal osteotomy slopes, and fibular height were calculated from CT scans. The wedge-hinge relationship and the zone of hinge position were assessed, and the patient and radiographic factors related to LHF occurrence were evaluated. RESULTS: Seventeen LHF cases (20.5%) were detected on plain radiographs, while significantly more (37 cases; 44.6%) were found on CT scans (P = .001). Based on Takeuchi classification, 28 LHF cases were considered type 1, 7 were type 2, and 2 were type 3. Logistic regression analysis revealed that opening gap width (odds ratio, 1.615; 95% confidence interval, 1.232-2.118; P = .001) and posterior opening gap width (odds ratio, 3.731; 95% confidence interval, 1.642-4.351; P = .008,) differed significantly between patients with versus without LHF. Other patient and radiographic factors were not significantly related to LHF occurrence. Receiver operating characteristic curve analysis identified the opening gap width cutoff values for LHF as 11.0 mm (area under the curve, 0.81; sensitivity, 78.4%; specificity, 73.9%). CONCLUSION: The incidence of LHF after MOWHTO can be underestimated on plain radiographs compared with CT scans. Only large opening gap width, especially posterior gap width, was found to have a statistically significant relationship with occurrence of LHF. Therefore, special caution for possible LHF may be needed if a large correction is planned.

RESUMEN

PURPOSE: With surgical modifications reflecting plate design differences of the specific rigid locking plate adding a metal wedge, uniplane high tibial osteotomy (HTO) has fewer lateral-hinge fractures and fewer plate irritations than biplane HTO. METHODS: Uniplane HTO with a rigid locking plate adding a metal wedge was compared with biplane HTO with a rigid locking plate including a proximal D-hole. For comparison, the HTO patients' medical records and radiological results in a single institution were retrospectively reviewed. The Oxford knee score 2 years post-operation, CT scan at post-operative day 2 and serial standing long-bone scanography were reviewed to evaluate clinical outcome and radiological results, including the incidence of lateral-hinge fracture, plate irritation and correction loss to varus alignment. RESULTS: A total of 103 knees, including 59 uniplane HTO and 44 biplane HTO, were enrolled. The Oxford scores were 38.1 ± 7.8 in the uniplane group and 35.9 ± 8.3 in the biplane group (ns). On CT scans, more lateral-hinge fractures developed in the biplane group, and seven knees (12%) of the uniplane group and 12 knees (27%) of the biplane group had Takeuchi type I stable hinge fracture (p < 0.05); unstable fracture was not noted in either group. Plate irritation occurred in nine knees (19%) of the uniplane group and in 14 knees (32%) of the biplane group, and the difference was statistically significant (p < 0.05). CONCLUSION: In clinical situations including the use of surgical modifications reflecting plate design differences, fewer lateral-hinge fractures developed after uniplane medial opening-wedge HTO compared with biplane HTO. Uniplane HTO potentially represents a better option than biplane HTO for the prevention of lateral-hinge fracture. LEVEL OF EVIDENCE: IV.

Asunto(s)

Placas Óseas/efectos adversos , Osteoartritis de la Rodilla/cirugía , Osteotomía/métodos , Tibia/cirugía , Fracturas de la Tibia/prevención & control , Anciano , Femenino , Genu Varum/cirugía , Humanos , Incidencia , Articulación de la Rodilla/cirugía , Masculino , Persona de Mediana Edad , Osteoartritis de la Rodilla/rehabilitación , Osteotomía/instrumentación , Osteotomía/rehabilitación , Estudios Retrospectivos , Tibia/lesiones , Fracturas de la Tibia/etiología

RESUMEN

BACKGROUND: Distal femur wedge osteotomies for varus or valgus alignment of the lower extremity could be done in either uniplanar or biplanar fashion.Union time and stability of the osteotomy site has been considered important in this anatomic region. In this study, clinical and radiographic findings of biplane distal femur osteotomy were reported. METHODS: Clinical, functional, and radiological findings of eight patients (10 knees) underwent biplane distal femur osteotomy were evaluated. Visual analogue score (VAS) and Lysholm-Tegner knee score were used for the assessment of pain and function before and three months after surgery. RESULTS: In this study, eight patients were included. All patients were female. The mean age was 28±6.3. The mean pre-operative mechanical angle was 8.7±2.2° and the post-operative angle was 1.4±0.53° in patients with valgus alignment whileit was 7.0±1.0°preoperatively and 0.66±1.2° postoperatively in patients with varus alignment. The mean lateral distal femoral angle (LDFA) was 85±8.0° before surgery and was 88±1.3° after surgery. According to Lysholm-Tegner knee score, in the post-operative visit, six knees were good and four were excellent. The mean union time was 9.2±2.3 weeks. CONCLUSIONS: Biplane distal femur osteotomy is a reliable technique that creates larger surfaces and more stability at the osteotomy site with further rapid union.