Pseudoaneurysm of the peroneal artery: an unusual complication of open docking site procedure in bone transport with Taylor Spatial Frame

A docking site is the terminus of travel of two segments of bone that are gradually brought into approximation, normally associated with the bone transport technique in limb reconstruction. Traumatic pseudoaneurysm of the peroneal artery have been reported following different types of trauma and orthopedic procedures performed in the distal leg. One uncommon case of delayed peroneal artery pseudoaneurysm following surgical docking site is described. The diagnosis was supported by angiography. Embolization with coil was a successful method of treatment. We recommend a safe method of osteotomy with good bone exposure and adequate soft tissue protection.     

Der Taylor Spatial Frame

Introduction

Posttraumatic deformities in the lower limb are mainly multidirectional, with angulation, translation, and rotatory deformities. Acute corrections with internal fixation are often not possible due to the soft tissue damage and the extent of the deformity. The Taylor Spatial Frame (TSF) allows correction in a virtual hinge with 6 axes, thus enabling the correction of multidirectional deformities simultaneously.

Methods

From February 2003 until December 2006, we applied 31 TSFs to 20 patients with a posttraumatic deformity of the tibia and hindfoot. The mean patient age was 41 years (range 12–73). 9 patients had a nonunion of the tibia with deformity, 6 had a malunion of the lower tibia and ankle, 3 had an angular deformity after ankle fusion, and 2 had malaligned Ilizarov bone segment transports. The mean follow-up time was 25.3 months (range 10–82).

Results

In all 20 patients, full correction of the deformity was achieved. The mean time for correction was 29 days (range 5–82). On average, the frame was worn (time to healing) 164.2 days (80–300) and the mean distraction rate was 1.1 mm/day (0.5–2.0). The Web-based planning was done two times per case for full deformity correction. Complications were 3 pin-site infections, 2 insufficient callus formations and 1 pinhole stress fracture.

Conclusions

The main advantage of the TSF compared with other external frames is the ability to perform simultaneous correction of angular, axial, translational, and rotatory deformities. This enables a reduced correction time and increased patient comfort.     

Histology of the regenerate and docking site in bone transport

Introduction  Bone transport is based on the principle of distraction osteogenesis described by Ilizarov and is a consecrated method for the treatment of segmental bone defects. One of its most problematic and, paradoxically, least studied aspects is the consolidation of the docking site. We studied histologically the ossification of the docking site and regenerate to determine any difference between them. Materials and methods  Nine adult sheep were submitted to correction of a 1-cm tibial diaphyseal defect using a system of plate-fixed bone transport, with latency period of 1 week and 0.2 mm distraction of the transported segment four times a day. The sheep were divided into three groups of three animals each, according to the observation period of 3, 6 or 12 weeks between the fixation of the transported fragment and the euthanasia. The docking site and the regenerate were studied histologically on sections stained with Masson trichrome. Results  The main mode of docking site ossification was the endochondral one and although intramembranous ossification was also observed simultaneously, it was limited to rare and small foci. In contrast, intramembranous ossification played the major role in the regenerate, with bone formation evolving from the base segment to the target segment. Conclusion  The experimental bone transport model proposed in the present study permits us to conclude that there is a clear difference between the ossification of the docking site and of the regenerate. No fundings or grants have been received for this study. The experiments comply with the current Brazilian laws for animal experimentation.     

Repair of tibial nonunions and bone defects with the Taylor Spatial Frame

OBJECTIVE: To investigate the outcomes of tibial nonunions and bone defects treated with the Taylor Spatial Frame (TSF) using the Ilizarov method. DESIGN: Retrospective. SETTING: Limb Lengthening and Deformity Service at an academic medical center. PATIENTS: Thirty-eight consecutive patients with 38 tibial nonunions were treated with the TSF. There were 23 patients with bone defects (average 5.9 cm) and 22 patients with leg-length discrepancy (LLD) (average 3.1 cm) resulting in an average longitudinal deficiency (sum of bone defect and LLD) of 6.5 cm in 31 patients (1-16). The average number of previous surgeries was 4 (0-20). At the time of surgery, 19 (50%) nonunions were diagnosed as infected. INTERVENTION: All patients underwent repair of the nonunion and application of a TSF. Patients with bone loss were additionally treated with lengthening. Infected nonunions were treated with 6 weeks of culture-specific antibiotics. MAIN OUTCOME MEASUREMENTS: Bony union, time in frame, eradication of infection, leg-length discrepancy, deformity, Short Form-36 (SF-36) scores, American Academy of Orthopaedic Surgeons (AAOS) lower-limb scores, and Association for the Study of the Method of Ilizarov (ASAMI) bone and functional results. RESULTS: Bony union was achieved after the initial treatment in 27 (71%) patients. The presence of bone infection correlated with initial failure and persistent nonunion (P=0.03). The 11 persistent nonunions were re-treated with TSF reapplication in 4, intramedullary rodding in 3, plate fixation in 2, and amputation in 2 patients. This resulted in final bony union in 36 (95%) patients. The average LLD was 1.8 cm (0-6.8) (SD 2). Alignment with deformity less than 5 degrees was achieved in 32 patients and alignment between 6 degrees and 10 degrees was achieved in 4 patients. Significant improvement of Short Form-36 (SF-36) scores was noted in physical role (P=0.03) and physical function (P=0.001). AAOS lower-limb module scores significantly improved from 56 to 82 (P<0.001). ASAMI bone and functional outcomes were excellent or good in 36 and 34 patients, respectively. The number of previous surgeries correlated inversely with the ASAMI bone (P=0.003) and functional (P=0.001) scores. CONCLUSIONS: One can comprehensively approach tibial nonunions with the TSF. This is particularly useful in the setting of stiff hypertrophic nonunion, infection, bone loss, LLD, and poor soft-tissue envelope. Infected nonunions have a higher risk of failure than noninfected cases. Treatment after fewer failed surgeries will lead to a better outcome. Internal fixation can be used to salvage initial failures.     

胫骨骨运输术中对接端新鲜化技术的临床观察

目的:研究胫骨骨运输术中对接端应用骨面新鲜化处理技术的效果。方法:对2014年1月至2019年12月胫骨骨运输术中对接端骨面新鲜化处理手术的20例患者进行分析。其中男15例,女5例;年龄19~62(42.3±11.5)岁;感染性7例,非感染性13例。对接端达到接触后即刻通过使骨面新鲜化处理的手术技术,清除卡入断端的皮肤和软组织,切除硬化封闭的骨端,改善对位,增加接触面积,术中即刻对对接端进行加压,并就近取骨植骨。术后继续逐渐加压。结果:缺损长度5~15(9.2±2.9) cm,从截骨到对接端接触需要26~243(109.1±51.1) d。所有患者对接端达到骨性愈合。达到影像学愈合标准需要3~7(3.7±1.1)个月,20例中15例需要腓骨截骨,其中14例腓骨的截骨端达到骨性愈合。胫骨牵开端的骨痂达到影像学坚实化的时间需要5~28(15.0±6.5)个月,骨愈合指数(bone healing index,BHI)为每厘米需0.8~2.8(1.6±0.5)个月。20例中1例胫骨切口出现感染。拆除外固定架后随访时间为12~73(37.6±20.3)个月,所有患者对接端未发生骨折。结论:胫骨骨运输术中,当对接端接触后尽早进行骨面新鲜化处理能缩短对接端的愈合时间,避免对接端再骨折,术中收集的松质骨和钻孔产生的骨屑能消除缺损和间隙,避免在其他部位取自体骨植骨。     

Taylor空间支架的临床应用进展

Taylor空间支架(Taylor spatial frame,TSF)是在Ilizarov技术的基础上,结合特定的计算机程序,输入各项参数后执行程序,根据计算机生成的电子处方来调节相应的支撑杆,进行畸形矫正的外固定系统。该文就TSF在创伤骨折及创伤后遗症治疗、四肢畸形矫正、足踝畸形矫正等方面的临床应用进展,作一简要综述。     

Preventing instability of the Taylor Spatial Frame (TSF) during a strut change

SUMMARY: During treatment with a Taylor Spatial Frame, some of the struts may need to be exchanged for one of a different length. An extra "seventh" strut is usually added to the frame during this procedure. This article describes a "technical trick" to ensure stability during a strut change. The frame was stable whenever the orientation of the "acute ring-strut" of the temporary strut matched that of the strut being exchanged. Clinicians must anticipate that instability can exist during strut changes, and this will depend on the particular configuration and position of the frame. Applying the rule indentified in this article may prevent instability, pain, and tissue damage.     

Pediatric and adolescent applications of the Taylor Spatial Frame

Limb deformity can occur in the pediatric and adolescent populations from multiple etiologies: congenital, traumatic, posttraumatic sequelae, oncologic, and infection. Correcting these deformities is important for many reasons. Ilizarov popularized external fixation to accomplish this task. Taylor expanded on this by designing an external fixator in 1994 with 6 telescoping struts that can be sequentially manipulated to achieve multiaxial correction of deformity without the need for hinges or operative frame alterations. This frame can be used to correct deformities in children and has shown good anatomic correction with minimal morbidity. The nature of the construct and length of treatment affects psychosocial factors that the surgeon and family must be aware of prior to treatment. An understanding of applications of the Taylor Spatial Frame gives orthopedic surgeons an extra tool to correct simple and complex deformities in pediatric and adolescent patients.     

Calculating the mounting parameters for Taylor Spatial Frame correction using computed tomography

The Taylor Spatial Frame uses a computer program-based six-axis deformity analysis. However, there is often a residual deformity after the initial correction, especially in deformities with a rotational component. This problem can be resolved by recalculating the parameters and inputting all new deformity and mounting parameters. However, this may necessitate repeated x-rays and delay treatment. We believe that error in the mounting parameters is the main reason for most residual deformities. To prevent these problems, we describe a new calculation technique for determining the mounting parameters that uses computed tomography. This technique is especially advantageous for deformities with a rotational component. Using this technique, exact calculation of the mounting parameters is possible and the residual deformity and number of repeated x-rays can be minimized. This new technique is an alternative method to accurately calculating the mounting parameters.     

Histological study of the docking site after bone transport. Temporal evolution in a sheep model

IntroductionBone transport appears to be a solution for segmental bone defects; specifically, the “docking site” is where the transported segment meets the target segment at the end of the process. A lack of its consolidation is one of the major causes of failure for this technique. Many studies have been performed in order to enhance the consolidation of the docking site, but histological changes occurring in it remain unknown. The aim of this study was to determine microscopic changes present in this area, from distraction to remodeling, in order to clarify the best options to facilitate the success of this technique.Materials and methodsTen adult sheep were submitted to bone transport using an Ilizarov external fixator. Histomorphometry and immunohistochemical studies were performed in the docking site to determine the main types of ossification, the evolutions of tissues and blood vessels and the distributions of collagen I and II.ResultsOssification was mainly intramembranous with some areas of endochondral ossification. Fibrous tissue was predominant until 98 days after surgery. The area occupied by blood vessels increased until 50 days after surgery, when it decreased slowly until the end of the study.ConclusionsAs far as the authors know, this is the first histological study performed in the docking site reporting the complete evolution of tissues until the end of remodeling, showing results contrary to those published by others authors. This could help to clarify information about its union and may be useful for future investigations about techniques for improving the consolidation of the docking site in humans.