Proximal tibial osteotomy for genu varum: Radiological evaluation of deformity correction with a plate vs external fixator

Abstract

BACKGROUND High tibial osteotomy (HTO) is a well-known procedure for the correction of knee varus. The purpose of this study was to compare the radiological results and accuracy of deformity correction performed using two different techniques: acute opening wedge correction using a plate and gradual correction with a monolateral external fixator. AIM To compare of the radiological results of two different techniques: acute opening wedge correction (a plate and screw) and gradual correction (external fixator). METHODS A total of 43 patients with plates and 36 patients with external fixators were included. All patients had moderate uniplanar varus deformities. We measured radiographic parameters, including the mechanical axis deviation (MAD), medial proximal tibial angle (MPTA), Caton-Deschamps Index (CDI), posterior proximal tibial angle, and joint line obliquity angle (JLOA). The accuracy of MAD correction was calculated based on a correction goal of neutral or overcorrection for medial compartment arthritis. RESULTS Demographics including age, body mass index, sex, and preoperative deformities were similar between the groups. The MAD significantly improved from 23.6 mm medial to the midline (SD = 8.2 mm) to 6.9 mm lateral to the midline (SD = 5.4 mm) ( P < 0.001). The accuracy of MAD correction did not differ between the groups and was 96.1% (SD = 8.1%) in the plate group and 98.2% (SD = 5.2%) in the external fixator group ( P = 0.18). The MPTA significantly improved from 83.9° (SD = 2.9°) to 90.9° (SD = 3.3°) ( P < 0.001), and the change was similar between the groups. Differences were noted in patella height, with a CDI change of -19.2% (SD = 13.7%) and 3.1% (SD = 8.0%) for the plate and external fixator groups, respectively ( P < 0.001). The change in JLOA was 1.6 degrees (SD = 1.1 degrees) and 0.9 degrees (SD = 0.9 degrees) for the plate and external fixator groups, respectively ( P = 0.04). CONCLUSION Reliable correction of moderate varus alignment was achieved with both the acute opening wedge technique with a plate and the gradual monolateral external fixator technique. The patellar height decreased with the open wedge plate technique. Joint line obliquity decreased to a greater degree with the open wedge plate technique, perhaps as a result of medial collateral ligament release. The appropriate technique should be selected based on surgeon and patient preferences; however, external fixation may be a better choice when the preservation of patellar height is deemed important.

Osteotomy treatments and post-operative fixations for Blount disease: A systematic review

“…Of the 15 articles, seven of them are retrospective studies, four of them are case reports, and four are prospective studies. Two of the seven retrospective studies were comparison studies [ 7 , 8 ]. As many as 273 patients (114 males and 155 females) with 330 lower limb surgeries were included in the studies reviewed.…”

“…The most featured technique featured in papers reviewed employed proximal tibial osteotomy [ 1 , 4 , 5 , [7] , [8] , [9] , 12 , 13 ] with different location of surgical interventions, namely intra-epiphyseal [ 11 ], metaphyseal [ [14] , [15] , [16] ], and subperiosteal [ 17 ] sites. At least three procedures described were performed as double osteotomy in a single surgery [ 10 , 17 , 18 ], and at least two described grafting fibular fragments into tibial openings [ 17 , 18 ].…”

“…At least three procedures described were performed as double osteotomy in a single surgery [ 10 , 17 , 18 ], and at least two described grafting fibular fragments into tibial openings [ 17 , 18 ]. Various types of osteotomies were performed in the studies, the most prominent were the opening-wedge osteotomy [ 7 , [9] , [10] , [11] ] and dome-shaped osteotomy [ 8 , 17 ]. Three case studies were reporting novel techniques to manage unique cases requiring special procedures, such as controlled gradual opening [ 10 ], Z-shaped osteotomy [ 4 ], and inverted V-shaped osteotomy [ 13 ].…”

“…Abnormal lower limb biomechanical axis causes damage to knee cartilage and affects the result of knee ligament reconstruction surgery. Inaccurate correction of varus deformation could lead to persistent pain [ 7 ] and cause socio-psychological problems like struggling with schooling, discrimination, low self-esteem, and depression for the patient or family [ 8 ].…”

“…Proximal tibial osteotomy coupled with mono-lateral external frame is a technique where the fibula and lateral tibial cortex are left intact during osteotomy. Realignment hinges on the gradual distraction of the medial cortex, through the intact lateral cortex [ 7 ]. Even severe tibial deformities associated with late presenting Blount disease could mostly be treated successfully by double PTO done within a single procedure [ 17 ].…”