Acute correction of severe complex adolescent late-onset tibia vara by minimally invasive osteotomy and simple circular fixation: a case series with 2-year minimum follow-up

Abstract

Background Despite multiple published reviews, the optimum method of correction and stabilisation of Blount’s disease remains controversial. The purpose of this study is to evaluate the clinical and radiological outcomes of acute correction of late-onset tibial vara by percutaneous proximal tibial osteotomy with circular external fixation using two simple rings. Weighing up the pros and cons and to establish if this method would be the method of choice in similar severe cases especially in a context of limited resources. Methods This study was conducted between November 2016 and July 2020. We retrospectively reviewed the clinical notes and radiographs of 30 patients (32 tibiae) who had correction of severe late-onset tibia vara by proximal tibial osteotomy and Ilizarov external fixator. The mean age at the time of the operation was 16.6 (± 2.7) years (range 13–22). Results The mean proximal tibial angle was 65.7° (± 7.8) preoperatively and 89.8° (± 1.7) postoperatively (p < 0.001). The mean mechanical axis deviation improved from 56.2 (± 8.3) preoperatively to 2.8 (± 1.6) mm postoperatively (p < 0.001). The mean femoral-tibial shaft angle was changed from –34.3° (± 6.7) preoperatively to 5.7° (± 2.8) after correction, with degree of correction ranging from 25° to 45°. Complications included overcorrection (three cases 9%) and pin tract infection (eight cases 25%). The mean Hospital for Special Surgery knee scoring system (HSS) improved from 51.03 (± 11.24) preoperatively to 94.2 (± 6.8) postoperatively (p < 0.001). The mean length of follow up period 33.22 (± 6.77) months, (rang: 25–46 months). At final follow up, all patients had full knee range of motion and normal function. All cases progressed to union and there were no cases of recurrence of deformity. Conclusion This simple procedure provides secure fixation allowing early weight bearing and early return to function. It can be used in the context of health care systems with limited resources. It has a relatively low complication rate. Our results suggest that acute correction and simple circular frame fixation is an excellent treatment choice for cases of late-onset tibia vara, especially in severe deformities.

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

“…As many as 273 patients (114 males and 155 females) with 330 lower limb surgeries were included in the studies reviewed. Mean correction angle reported in the studies ranged from 17.64° [ 9 ] to 45° [ 5 ]. One case report was qualitative in nature and does not disclose the sex and age of the patient [ 10 ].…”

“…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 ].…”

“…This review saw majority of the reported osteotomies were stabilized using internal fixations, with minimal screws [ 12 ], plates and screws [ 1 , 9 , 13 , 15 , 16 ], and K-wires [ 4 , 17 , 18 ]. The rest of external fixations described mainly used the hexapod rings resembling Ilizarov apparatus [ 5 , 14 ] and one considered using mono-lateral L-shaped pins to achieve gradual correction [ 10 ]. A patient with Turner syndrome (the absence of one X chromosome which cause various anatomic anomalies in the musculoskeletal system, including progressive varus deformity of the proximal tibia) was also reported to had undergone two bilateral osteotomy procedures with different types of fixation [ 13 ] ( Table 2 ).…”

“…In both fixation methods, pin breakage and pin site infections around screws or wires were the most frequent complication encountered [ 12 , 16 ], however deep infections requiring a complete debridement was a rare occurrence. Multiple drilling holes and screw tampering can cause loosening and infections, especially in the proximal metaphyseal part [ 5 ].…”

“…For late onset and severe deformities, proximal tibial osteotomy for correction regardless of the fixation method was generally suggested. However, there is few evidence to prescribe one form of fixation over the other [ 5 ].…”