Objective To compare the functional and radiological outcomes of supramalleolar osteotomy (SMOT) between with and without fibular osteotomy for varus ankle osteoarthritis. Methods Between April 2009 and April 2014, 41 patients (41 feet) with mid-staged varus ankle osteoarthritis were treated with SMOT. Fibular osteotomy was not performed in 19 cases (group A), and fibular osteotomy was performed in 22 cases (group B). There was no significant difference in gender, age, side, body mass index, osteoarthritis stage, pathogeny, American Orthopedic Foot and Ankle Society (AOFAS) ankle-hind score, ankle osteoarthritis scale (AOS) pain and function scores, range of motion (ROM) of the ankle joint, tibial articular surface angle (TAS), talar tilt angle (TT), tibiocrural angle (TC), and tibial lateral surface angle (TLS) between 2 groups (P>0.05). The bone union was observed after operation, and functional and radiological outcomes were compared between 2 groups at last follow-up. Results All incisions healed by stage I, and no surgery related complications occurred. The mean follow-up time was 36.6 months (range, 16-55 months). Pain and limited activity were observed in 1 case of groups A and B respectively, and ankle arthrodesis was performed. All cases achieved bony union; the bone union time was (3.6±0.4) months in group A and (3.9±0.7) months in group B, showing no significant difference (t=1.61,P=0.12). At last follow-up, no significant difference was found in TAS, TLS, TT, and TC between groups (P>0.05). However, group B was significantly better than group A in improvement of TT and TC (P<0.05). The AOFAS ankle-hind score, AOS pain and function scores, ROM of the ankle joint showed no significant difference between groups (P>0.05). According to the modified Takakura stage, the improvement rates of groups A and B were 55.6% and 57.1%, respectively; no significant difference was found between 2 groups (χ2=0.01,P=0.92). Conclusion SMOT with fibular osteotomy is helpful in correction of TT and TC in patients with relative longer fibula.
Objective To establish the finite element model of varus-type ankle arthritis and to implement the finite element mechanical analysis of different correction models for tibial anterior surface angle (TAS) in supramalleolar osteotomy. Methods A female patient with left varus-type ankle arthritis (Takakura stage Ⅱ, TAS 78°) was taken as the study object. Based on the CT data, the three-dimensional model of varus-type ankle arthritis (TAS 78°) and different TAS correction models [normal (TAS 89°), 5° valgus (TAS 94°), and 10° valgus (TAS 99°)] were created by software Mimics 21.0, Geomagic Wrap 2021, Solidworks 2017, and Workbench 17.0. The 290 N vertical downward force was applied to the upper surface of the tibia and 60 N vertical downward force to the upper surface of the fibula. Von Mises stress distribution and stress peak were calculated. Results The finite element model of normal TAS was basically consistent with biomechanics of the foot. According to biomechanical analysis, the maximum stress of the varus model appeared in the medial tibiotalar joint surface and the medial part of the top tibiotalar joint surface. The stress distribution of talofibular joint surface and the lateral part of the top tibiotalar joint surface were uniform. In the normal model, the stress distributions of the talofibular joint surface and the tibiotalar joint surface were uniform, and no obvious stress concentration was observed. The maximum stress in the 5° valgus model appeared at the posterior part of the talofibular joint surface and the lateral part of the top tibiotalar joint surface. The stress distribution of medial tibiotalar joint surface was uniform. The maximum stress of the 10° valgus model appeared at the posterior part of the talofibular joint surface and the lateral part of the top tibiotalar joint surface. The stress on the medial tibiotalar joint surface increased. Conclusion With the increase of valgus, the stress of ankle joint gradually shift outwards, and the stress concentration tends to appear. There was no obvious obstruction of fibula with 10° TAS correction. However, when TAS correction exceeds 10° and continues to increase, the obstruction effect of fibula becomes increasingly significant.
Objective To assess the effectiveness of supramalleolar osteotomy (SMOT) as a therapeutic intervention for varus-type ankle arthritis, while also examining the associated risk factors that may contribute to treatment failure. MethodsThe clinical data of 82 patients (89 feet) diagnosed with varus-type ankle arthritis and treated with SMOT between January 2016 and December 2020 were retrospectively analyzed. The patient cohort consisted of 34 males with 38 feet and 48 females with 51 feet, with the mean age of 54.3 years (range, 43-72 years). The average body mass index was 24.43 kg/m2 (range, 20.43-30.15 kg/m2). The preoperative tibial anterior surface angle (TAS) ranged from 77.6° to 88.4°, with a mean of 84.4°. The modified Takakura stage was used to classify the severity of the condition, with 9 feet in stage Ⅱ, 41 feet in stage Ⅲa, and 39 feet in stage Ⅲb. Clinical functional assessment was conducted using the Maryland sore, visual analogue scale (VAS) score, and psychological and physical scores in Health Survey 12-item Short From (SF-12). Radiology evaluations include TAS, talar tilt (TT), tibiocrural angle (TC), tibial medial malleolars (TMM), tibiocrural distance (TCD), tibial lateral surface angle (TLS), and hindfoot alignment angle (HAA). The results of clinical failure, functional failure, and radiology failure were statistically analyzed, and the related risk factors were analyzed. ResultsThe operation time ranged from 45 to 88 minutes, with an average of 62.2 minutes. No complication such as fractures and neurovascular injuries was found during operation. There were 7 feet of poor healing of the medial incision; 9 pin tract infections occurred in 6 feet using external fixator; there were 20 cases of allograft and 3 cases of autograft with radiographic bone resorption. Except for 1 foot of severe infection treated with bone cement, the remaining 88 feet were primary healing, and the healing area was more than 80%. All patients were followed up 24-82 months, with an average of 50.2 months. Maryland score, VAS score, SF-12 psychological and physiological scores, and TAS, TC, TLS, TCD, TT, TMM, HAA, and Takakura stage were significantly improved at last follow-up (P<0.05). Postoperative clinical failure occurred in 13 feet, functional failure in 15 feet, and radiology failure in 23 feet. Univariate analysis showed that obesity, TT>10°, and Takakura stage Ⅲb were risk factors for clinical failure, HAA≥15° and Takakura stage Ⅲb were risk factors for functional failure, and TT>10° was risk factor for radiographic failure (P<0.05). Further logistic regression analysis showed that TT>10°, HAA≥15°, and TT>10° were risk factors for clinical failure, functional failure, and radiographic failure, respectively (P<0.05). Conclusion SMOT is effective in the mid- and long-term in the treatment of varus-type ankle arthritis, but it should be used with caution in patients with obesity, severe hindfoot varus, severe talus tilt, and preoperative Takakura stage Ⅲb.
Objective To evaluate the influence of lateral hinge fracture (LHF) on the early effectiveness of supramalleolar osteotomy (SMO) and to explore the related risk factors for LHF. Methods A total of 39 patients (39 feet) with varus-type ankle osteoarthritis treated with SMO between January 2016 and December 2022 were analyzed retrospectively. There were 10 males and 29 females, aged from 41 to 71 years (mean, 57.7 years). According to Takakura stage, there were 6 feet in stage Ⅱ, 19 feet in stage Ⅲa, and 14 feet in stage Ⅲb. The LHF was recognized by the immediate postoperative X-ray film. The osteotomy healing time and the changes of pain visual analogue scale (VAS) score, American Orthopaedic Foot and Ankle Society (AOFAS) score, tibial anterior surface angle (TAS), tibial lateral surface angle (TLS), and tibiotalar angle (TT) before and after operation were compared between patients with and without LHF. The age, gender, affected side, body mass index, Takakura stage, preoperative VAS score, preoperative AOFAS score, preoperative TAS, preoperative TLS, preoperative TT, SMO correction angle, osteotomy distraction, distance from medial osteotomy to ankle joint line (MD), and distance from lateral osteotomy to ankle joint line (LD) were compared between with and without LHF patients, and further logistic regression analysis was used to screen the risk factors of LHF during SMO. Results All patients were followed up 12-54 months (mean, 27.1 months). During operation, 13 feet developed LHF (group A) and 26 feet did not develop LHF (group B). X-ray film reexamination showed that 1 patient in group A complicated with tibial articular surface cleft fracture had delayed osteotomy and healed successfully after plaster fixation; the osteotomy of other patients healed, and there was no significant difference in healing time between the two groups (P>0.05). At last follow-up, there were significant differences in VAS score, AOFAS score, TAS, TLS, and TT of the two groups when compared with preoperative ones (P<0.05), but there was no significant difference in the changes of above indicators before and after operation between the two groups (P>0.05). The differences in SMO correction angle, osteotomy distraction, and LD between with and without LHF patients were significant (P<0.05), and further logistic regression analysis showed that excessive LD was the risk factor of LHF during SMO (P<0.05). Conclusion Too high or too low lateral hinge position during SMO may lead to LHF, but as long as appropriate treatment and rehabilitation measurements are taken, the early effectiveness is similar to that of patients without LHF.