Establishment of finite element model of varus-type ankle arthritis and biomechanical analysis of different correction models for tibial anterior surface angle / 中国修复重建外科杂志

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.

Effectiveness and risk factors of supramalleolar osteotomy in treatment of varus-type ankle arthritis / 中国修复重建外科杂志

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.@*METHODS@#The 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/m 2 (range, 20.43-30.15 kg/m 2). 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.@*RESULTS@#The 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.

Effectiveness comparison of supramalleolar osteotomy and ankle arthrodesis in treatment of inverted ankle osteoarthritis in Takakura 3A stage with talus tilt / 中国修复重建外科杂志

OBJECTIVE@#To compare the effectiveness of supramalleolar osteotomy (SMOT) and ankle arthrodesis (AA) in the treatment of inverted ankle osteoarthritis (OA) in Takakura 3A stage with talus tilt.@*METHODS@#The clinical data of 41 patients with inverted ankle OA in Takakura 3A stage with talus tilt admitted between January 2016 to January 2020 and met the selection criteria were retrospectively analyzed, and they were divided into SMOT group (21 cases) and AA group (20 cases) according to the surgical method. There was no significant difference in baseline data such as gender, age, affected side, cause of injury, and preoperative talar tilt angle (TT), American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, visual analogue scale (VAS) score, short-form 36 health survey scale (SF-36) score, and sagittal range of motion (ROM) between the two groups ( P>0.05). The operation time, intraoperative blood loss, partial weight-bearing time, and complications were recorded in the two groups. AOFAS ankle-hindfoot score, VAS score, SF-36 score, and sagittal ROM were used to evaluate the effectiveness. Bone healing was observed and the time of bony healing was recorded. In the SMOT group, the tibial lateral surface angle (TLS), TT, and the tibial articular surface angle (TAS) were measured on ankle joint weight-bearing anteroposterior and lateral X-ray films and compared with those before operation. And Takakura staging assessment was also performed.@*RESULTS@#The operation time and intraoperative blood loss in AA group were significantly less than those in SMOT group ( P<0.05). Patients in both groups were followed up 24-36 months, with an average of 28.9 months. Incision infection occurred in 2 patients in SMOT group and 1 patient in AA group, respectively, and no vascular or nerve injury occurred in both groups. The partial weight-bearing time of SMOT group was significantly less than that of AA group ( P<0.05), but there was no significant difference in bony healing time between the two groups ( P>0.05). At last follow-up, the difference of VAS score and SF-36 score before and after operation of AA group were less than those of SMOT group, and the difference of sagittal ROM before and after operation in SMOT group was less than that of AA group, with significant differences ( P<0.05). The difference of AOFAS ankle-hindfoot score before and after operation in AA group was slightly greater than that in SMOT group, but the difference was not significant ( P>0.05). The above scores in both groups significantly improved when compared with those before operation ( P<0.05). Sagittal ROM in AA group was significantly less than that before operation ( P<0.05), while there was no significant difference in SMOT group ( P>0.05). In the SMOT group, 17 patients (81.0%) showed improvement in imaging staging, 2 patients (9.5%) showed no improvement in staging, and 2 patients (9.5%) showed stage aggravation. TLS, TAS, and TT significantly improved when compared with those before operation ( P<0.05). At last follow-up, 2 patients in SMOT group received AA due to pain and stage aggravation, and 1 patient with bone nonunion underwent bone graft. Subtalar joint fusion was performed in 1 case of subtalar arthritis in AA group.@*CONCLUSION@#For inverted ankle OA in Takakura 3A stage with talus tilt, both SMOT and AA can significantly releave pain, improve foot function and quality of life, but AA has more definite effectiveness and better patient satisfaction.

Instrumentation with 3D printed patient-specific guides versus conventional techniques in supramalleolar osteotomy for varus ankle osteoarthritis / 中华创伤骨科杂志

Objective To compare instrumentation with 3D-printed patient-specific guides versus conventional techniques in supramalleolar osteotomy for varus ankle osteoarthritis.Methods A retrospective analysis was done of the 21 patients with varus ankle osteoarthritis who had been treated at Department of Orthopaedics,Shanghai JiaoTong University Affiliated Sixth People's Hospital from January 2017 to December 2018.They were divided into 2 groups by their treatment methods.In the 9 patients treated by instrumentation with 3D-printed patient-specific guides,there were 6 males and 3 females with an age of 54.6 ±8.6 years,4 left and 5 right sides involved,and one case of Takakura stage 1,3 cases of Takakura stage 2 and 5 cases of Takakura stage 3a.In the 12 patients treated by conventional techniques,there were 7 males and 5 females with an age of 53.0 ± 6.5 years,7 left and 5 right sides involved,and one case of Takakura stage 1,5 cases of Takakura stage 2 and 6 cases of Takakura stage 3a.The 3D printed guide group and the conventional group were compared in terms of operation time,intraoperative blood loss and frequency of intraoperative fluoroscopy,tibial anterior surface angle (TAS),talar tilt angle (TT),and tibial lateral surface angle (TLS).The differences in TAS,TT and TLS between pre-and post-operation in the 3D printed guide group were also evaluated.Results There were no significant differences in the preoperative general data between the 2 groups (P ＞ 0.05),indicating they were comparable.All the patients were available for follow-up for an average of 7.8 months (from 3 to 15 months).The 3D printed guide group incurred significantly shorter operation time (106.2 ± 10.6 min),less intraoperative blood loss (207.2 ± 16.0 mL) and lower fluoroscopy frequency (2 ± 0) than the conventional osteotomy group (all P ＜ 0.01).The post-operative TAS (94.3° ± 3.2°) and TT (3.8° ± 0.8°) angles in the 3D guide group were significantly different from their preoperative values (84.6°±3.5° and 7.6°± 1.6°) (P ＜ 0.01).The 3D printed guide group was not significantly different from the conventional group in postoperative TAS (94.3°± 3.2° versus 92.4°±5.9°),TT (3.8° ± 0.8° versus 4.2° ± 1.1°) or TLS (83.7° ± 3.4° versus 84.2° ± 2.2°) angles (P ＞0.05).Conclusions Compared with conventional techniques,instrumentation with 3D-printed patient-specific guides can shorten operation time and reduce intraoperative blood loss and fluoroscopy frequency.The 3D printed patient-specific guides in osteotomy can facilitate accurate correction of varus deformity,leading to similar efficacy compared with conventional osteotomy.

Instrumentation with 3D printed patient-specific guides versus conventional techniques in supramalleolar osteotomy for varus ankle osteoarthritis / 中华创伤骨科杂志

Objective@#To compare instrumentation with 3D-printed patient-specific guides versus conventional techniques in supramalleolar osteotomy for varus ankle osteoarthritis.@*Methods@#A retrospective analysis was done of the 21 patients with varus ankle osteoarthritis who had been treated at Department of Orthopaedics, Shanghai JiaoTong University Affiliated Sixth People's Hospital from January 2017 to December 2018. They were divided into 2 groups by their treatment methods. In the 9 patients treated by instrumentation with 3D-printed patient-specific guides, there were 6 males and 3 females with an age of 54.6±8.6 years, 4 left and 5 right sides involved, and one case of Takakura stage 1, 3 cases of Takakura stage 2 and 5 cases of Takakura stage 3a. In the 12 patients treated by conventional techniques, there were 7 males and 5 females with an age of 53.0±6.5 years, 7 left and 5 right sides involved, and one case of Takakura stage 1, 5 cases of Takakura stage 2 and 6 cases of Takakura stage 3a. The 3D printed guide group and the conventional group were compared in terms of operation time, intraoperative blood loss and frequency of intraoperative fluoroscopy, tibial anterior surface angle (TAS), talar tilt angle (TT), and tibial lateral surface angle (TLS). The differences in TAS, TT and TLS between pre- and post-operation in the 3D printed guide group were also evaluated.@*Results@#There were no significant differences in the preoperative general data between the 2 groups (P>0.05), indicating they were comparable. All the patients were available for follow-up for an average of 7.8 months (from 3 to 15 months). The 3D printed guide group incurred significantly shorter operation time (106.2±10.6 min), less intraoperative blood loss (207.2±16.0 mL) and lower fluoroscopy frequency (2±0) than the conventional osteotomy group (all P<0.01). The post-operative TAS (94.3°±3.2°) and TT (3.8°±0.8°) angles in the 3D guide group were significantly different from their preoperative values (84.6°±3.5° and 7.6°±1.6°) (P<0.01). The 3D printed guide group was not significantly different from the conventional group in postoperative TAS (94.3°±3.2° versus 92.4°±5.9°), TT (3.8°±0.8° versus 4.2°±1.1°) or TLS (83.7°±3.4° versus 84.2°±2.2°) angles (P>0.05).@*Conclusions@#Compared with conventional techniques, instrumentation with 3D-printed patient-specific guides can shorten operation time and reduce intraoperative blood loss and fluoroscopy frequency. The 3D printed patient-specific guides in osteotomy can facilitate accurate correction of varus deformity, leading to similar efficacy compared with conventional osteotomy.

New progress in joint-preserving treatment of ankle osteoarthritis / 中华创伤骨科杂志

Ankle osteoarthritis (OA),a progressive disease,will develop into its full end-stage in the long run if no appropriate treatment is given.Joint-sacrificing procedures,such as total ankle replacement and ankle arthrodesis,used to be mostly applied for treatment of painful mid-and end-stage ankle OA,leading to adverse effects in functional recovery,complications and treatment costs.In recent years,joint-preserving surgery has emerged as an increasingly common treatment for mid-stage ankle OA at home and abroad.It has become a hot topic in the field of foot and ankle surgery,because it may restore normal biomechanics of the ankle joint,substantially relieve postoperative pain,improve function,and prevent or slow the degeneration process.This paper reviews the new progress in joint-preserving treatment of ankle OA.

Low Tibial Osteotomy / 대한족부족관절학회지

Low tibial osteotomy is an extra-articular procedure that realigns the mechanical axis, restoring ankle function. It is also an alternative surgical procedure to manage early osteoarthritis of the ankle joint. This can mainly address ankle varus/valgus, as well as procurvatum/recurvatum, internal/external rotation, equinus, calcaneus, and limb length discrepancy. The authors describe the history, mechanism, indications, and limitations of low tibial osteotomy focused on osteoarthritis of the ankle with varus malalignment reviewing several articles published thus far.

Supramalleolar Osteotomy in Patients with Varus Ankle Osteoarthritis / 대한족부족관절학회지

This article has reviewed the alignment of the ankle and hindfoot in varus ankle osteoarthritis. The indication and surgical technique of the supramalleolar osteotomy has been reviewed. Alignment of tibial plafond and hindfoot is variable in early stages of ankle osteoarthritis. Supramalleolar osteotomy is indicated for the treatment of ankle osteoarthritis in patients with minimal talar tilt and neutral or varus heel alignment.