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

Complex rigid foot deformity correction with hexapod external fixator system

PURPOSE

Complex rigid foot deformities include three-plane deformities and usually presents with poor soft tissue coverage. In the last decades, gradual correction with computer-assisted fixator became an appropriate option for the treatment rigid foot deformities. This study aims to report our experience about treatment of complex foot deformities using Smart Correction fixator system®.

METHODS

We retrospectively analyzed 13 complex rigid foot deformities of ten consecutive patients treated with Smart Correction fixator system® from 2016 to 2020. Primary outcomes were classified as good, fair, and poor according to previously determined criteria. The outcomes were also assessed with The Manchester-Oxford Foot Questionnaire (MOXFQ). Non-parametric analysis (Wilcoxon test) for continuous variables and the Fisher's exact test for categorical variables were used.

RESULTS

Plantigrade foot was achieved in all patients after correction program. Supramalleolar osteotomy was applied in nine feet, midfoot osteotomy was applied in two feet, hindfoot osteotomy was required in one foot, and only soft tissue distraction performed in two feet. Two patients had recurrent deformity managed by further acute corrections. The mean MOXFQ scores improved from 72.7 preoperatively to 24.8 at last follow-up.

CONCLUSIONS

Present study shows that SCF the reliable option for the treatment of complex foot deformities, which also facilitates three-plane correction and concomitant lengthening with gradual soft tissue balance.

Accuracy of the hexapod external fixator in treating tibial angular deformities with or without limb length discrepancy: a retrospective study

OBJECTIVE

Hexapod external fixator systems allow simultaneous deformity correction in multiple planes as well as limb lengthening. The aim of this study is to evaluate the accuracy of a hexapod frame (smart correction frame) in different types of tibial deformities requiring correction with or without lengthening.

METHODS

A total of 54 tibial angular deformities and limb length discrepancies operated with a hexapod frame between January 2015 and January 2021 were classified into four groups: "Group A ( n  = 13): only lengthening," "Group B ( n  = 14): lengthening and uniplanar correction," "Group C ( n  = 16): only uniplanar correction," and "Group D ( n  = 11): biplanar correction." The accuracy of angular deformity correction/lengthening was calculated by dividing the actual correction/lengthening achieved after frame removal by the preoperative planned lengthening/correction.

RESULTS

The lengthening accuracy in Group A and Group B was 96.3 ± 7.1% and 95.7 ± 5.9%, respectively ( P  = 0.685). The angular deformity correction accuracy was 85.1 ± 9.9% for Group B, 85.2 ± 13.9% for Group C, and 80.2 ± 18.4% for Group D ( P  = 0.852). A revision program was performed in six cases (1 in Group B, 1 in Group C, and 4 in Group D) for full correction of the deformities.

CONCLUSION

The accuracy of tibial lengthening is high with the hexapod frame and is minimally affected by simultaneous deformity correction; however, the accuracy of angular correction slightly reduces as the deformity becomes more complex. Surgeons should be aware that reprogramming may be required after complex deformity correction.

Staged correction trajectory with hexapod external fixator for the satisfactory reduction of long bone shaft fracture

Backgroud

When the reduction of long bone shaft fracture fragments is performed by a hexapod external fixator, the collision and interference between bony ends often results in an incomplete reduction and a time-consuming procedure. The purpose of this study was to present and determine the clinical effectiveness of staged correction trajectory with hexapod external fixator in the reduction of a long bone shaft fracture.

Methods

A total of 57 patients with tibial shaft fractures treated by hexapod external fixator were retrospectively analyzed from June 2016 to February 2020. Thirty-one cases (Group I) underwent a conventional one-step reduction trajectory from June 2016 to July 2018. Starting in September 2018, the other twenty-six patients (Group II) underwent staged correction trajectory (three key points reduction trajectory of “distraction-derotation-reduction”). The demographic data, residual deformities before and after correction, number of repeated X-rays after the first postoperative X-ray, duration of deformity correction process, and external fixation time were analyzed. Johner-Wruhs criteria were used to evaluate the final clinical outcomes.

Results

All the 57 patients achieved satisfactory fracture reduction and bone union. There were no significant differences between the two groups in demographic data, residual deformities before and after correction, external fixation time, and final clinical outcomes (p > 0.05). The average number of repeated X-rays after the first postoperative X-ray and mean duration of deformity correction process in Group II (1.3 times, 2.9 days) were all less than those in Group I (2.3 times, 5.1 days) (p < 0.05).

Conclusion

Compared with the conventional one-step reduction trajectory, there is no differences in final clinical outcomes, but the staged correction trajectory provides less repeated X-rays and shorter reduction process duration.

Hospitalization for computer-assisted hexapod ring fixation application – analyses of patient variability, peri-operative complications, hospital costs, and discharge status

Background

Computer-assisted hexapod ring fixation systems (HRF) are used for multiple conditions and in very diverse patient populations. This study analyzes perioperative outcomes following HRF application based on patient etiology and clinical presentation.

Methods

Data from patients in the Premier Hospital Billing Database between 2007–2019 undergoing HRF application were analyzed for the duration of patients’ hospitalizations. Patients were grouped based on etiology: acquired deformity, arthrosis, congenital deformity, deep infection, infected nonunion, fracture, nonunion, and other post-operative complications. Demographics, comorbidities, operating room time (ORT), length of stay (LOS), peri-operative complications, and hospital costs were estimated using generalized linear models. Logistic regression evaluated factors associated with peri-operative complications.

Results

One thousand eight hundred eighteen patients (average age: 46.9, standard deviation (SD) (19.6) – 38.9% female) were included in the study, and included 72% fracture cases, 9.6% deep infection, 10.2% deformity (acquired: 5.9%, congenital: 4.3%), 4.2% nonunions, 2% arthrosis and 1.4% other sequelas from prior fractures. Comorbidities varied across diagnosis categories and age, 40% adults and 86% pediatric had no comorbidities. Pediatric cases mostly suffered from obesity (16.1%) and pulmonary disease (10.7%). Complicated diabetes was present in 45.9% of arthropathy and 34.3% of deep infection patients. ORT, LOS and inflation-adjusted hospital costs for all patients averaged 277.7 min (95% Confidence interval (CI): 265.1–290.3), 7.07 days (95% CI: 6.6–7.5) and $41,507 (95%CI: $39,728-$43,285), respectively, but were highest in patients with deep infection (ORT: 369 min (95%CI: $321.0-$433.8); LOS: 14.4 days (95%CI: $13.7-$15.1); Cost: $54,666 (95%CI: $47,960-$63,553)). The probability of having an intraoperative complication averaged 35% (95%CI: 28%-43%) in adult patients with deep infection vs 7% (95%CI: 2%-20%) in pediatric cases treated for congenital deformity. The risk for intraoperative complications was mostly associated with preexisting comorbidities, an Elixhauser > 5 was the most predictive risk factor for complications (odds ratios: 4.53 (95%CI: 1.71–12.00, p = 0.002).

Conclusions

There is important heterogeneity among HRF patients. Adults with HRF for fracture, deep infection and arthrosis are at far greater risk for peri-operative complications vs. patients with deformity, especially pediatric deformity cases, mostly due to existing comorbidities and age. Device-specific HRF clinical studies cannot be generalized beyond their exact patient population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05171-6.

Marker- three dimensional measurement versus traditional radiographic measurement in the treatment of tibial fracture using Taylor spatial frame

Background

The Taylor Spatial Frame (TSF) has been widely used for tibial fracture. However, traditional radiographic measurement method is complicated and the reduction accuracy is affected by various factors. The purpose of this study was to propose a new marker- three dimensional (3D) measurement method and determine the differences of reduction outcomes, if any, between marker-3D measurement method and traditional radiographic measurement in the TSF treatment.

Methods

Forty-one patients with tibial fracture treated by TSF in our institution were retrospectively analyzed from January 2016 to June 2019, including 21 patients in the marker-3D measurement group (experimental group) and 20 patients in the traditional radiographic measurement group (control group). In the experimental group, 3D reconstruction with 6 markers installed on the TSF was performed to determine the electronic prescription. In the control group, the anteroposterior (AP) and lateral radiographs were performed for the traditional parameter measurements. The effectiveness was evaluated by the residual displacement deformity (RDD) and residual angle deformity (RAD) in the coronal and sagittal plane, according to the AP and lateral X-rays after reduction.

Results

All patients achieved functional reduction. The residual RDD in AP view was 0.5 (0, 1.72) mm in experimental group and 1.74 (0.43, 3.67) mm in control group. The residual RAD in AP view was 0 (0, 1.25) ° in experimental group and 1.25 (0.62, 1.95) °in control group. As for the lateral view, the RDD was 0 (0, 1.22) mm in experimental group and 2.02 (0, 3.74) mm in control group, the RAD was 0 (0, 0) ° in experimental group and 1.42 (0, 1.93) ° in control group. Significant differences in all above comparisons were observed between the two groups (AP view RDD: P = 0.024, RAD: P = 0.020; Lateral view RDD: P = 0.016, RAD: P = 0.004).

Conclusions

The present study introduced a marker-3D measurement method to complement the current TSF treatment. This method avoids the manual measurement error and improves the accuracy of fracture reduction, providing potential advantages of bone healing and function rehabilitation.

Distance from the magnification device contributes to differences in lower leg length measured in patients with TSF correction

INTRODUCTION

In absence of deformity or injury of the contralateral leg, the contralateral leg length is used to plan limb lengthening. Length variability on long-leg weight-bearing radiographs (LLR) can lead to inaccurate deformity correction. The aim of the study was to (1) examine the variability of the measured limb length on LLR and (2) to examine the influence of the position of the magnification device.

MATERIALS AND METHODS

The limb lengths of 38 patients during deformity correction with a taylor-spatial-frame were measured retrospectively on 7.3 ± 2.6 (4-13) LLR per patient. The measured length of the untreated limb between LLR were used to determine length variability between LLR in each patient. To answer the secondary aim, we took LLR from a 90 cm validation distance. A magnification device was placed in different positions: at the middle of the 90 cm distance (z-position), 5 cm anterior and 5 cm posterior from the z-position, at the bottom and top of the validation distance as well as 5 cm medial and 15 cm lateral from the z-position.

RESULTS

The measured length variability ranged within a patient from 10 to 50 mm. 76% of patients had a measured limb length difference of ≥ 2 cm between taken LLR. Compared to length measurement of the 90 cm test object with the magnification device in the z-position (90.1 cm), positioning the device 5 cm anterior led to smaller (88.6 cm) and 5 cm posterior led to larger measurements (91.7 cm). The measured length with the magnification device at the bottom, top, medial or lateral (90.4; 89.9; 90.2; 89.8 cm) to the object differed not relevantly.

CONCLUSIONS

High variability of limb length between different LLR within one patient was observed. This can result from different positions of the magnification device in the sagittal plane. These small changes in positioning the device should be avoided to achieve accurate deformity correction and bone lengthening. This should be considered for all length and size measurements on radiographs.

Opening Wedge High Tibial Osteotomy with Combined Use of Patient-Specific 3D-Printed Plates and Taylor Spatial Frame for the Treatment of Knee Osteoarthritis

Background

High tibial osteotomy (HTO) is used to treat medial degeneration of the osteoarthritis (OA) knee. However, shortcomings still exist in the current procedure, like unprecise creation, inability to correct knee rotation, and internal fixed failure. Here, we reported a novel procedure: patient-specific 3D-printed plates for opening wedge high tibial osteotomy (OWHTO) combined with Taylor spatial frame (TSF). The detailed technique was described, and the clinical outcomes were evaluated.

Methods

We prospectively evaluate outcomes of patient-specific 3D-printed plates for OWHTO with use of TSF in 25 patients with knee OA and varus alignment. Postoperative efficacy was evaluated using the HSS knee score, pain visual simulation score (VAS), and knee joint motion (ROM), and lower limb alignment was evaluated by measuring femorotibial angle (FTA) and hip-knee-ankle (HKA). Results and Conclusion. All patients did not experience complications such as wound infection, nerve damage, or bone amputation. 25 patients were followed up for 6–18 months. The bony union at bone amputation was achieved in 3 months after surgery, and the pain symptoms were significantly alleviated or disappeared. The VAS score was significantly reduced in 6 months after surgery compared with preoperative; the HSSS score was significantly added in 6 months after surgery compared with preoperative. The ROM of knee joint increased significantly 6 months after operation compared with that before operation, and the difference was statically significant (P < 0.05). The FTA and HKA after operation were significantly superior to that before operation, and the difference was statically significant (P < 0.01).

Conclusions

Our study showed that patient-specific 3D-printed plates for HTO with the use of TSF have the advantages of small trauma, few complications, simple operation, and fast recovery in treating knee OA and varus alignment.

Improving postoperative radiographs for the parameter measurement of hexapod external fixator using an additional foot ring

BACKGROUND

It is challenging to determine the orthogonality of radiographs in daily clinical practice. The purpose of this study was to show the usefulness of an additional foot ring which might determine the orthogonality of postoperative radiographs for the parameter measurement of hexapod external fixator.

METHODS

We retrospectively analyzed 81 consecutive trauma patients with tibial shaft fractures treated by the hexapod external fixator at our institution from September 2014 to July 2019. Starting in March 2016, the postoperative radiographs for parameter measurement were obtained under the control of an additional foot ring. The final data consisted of 47 patients in traditional radiographs (Group I) and 34 patients under the control of foot ring during the radiographic process (Group II). The demographic data, original postoperative deformities, residual deformities after final correction, number of repeated radiographs after the first postoperative radiographs, time to the satisfactory reduction achieved, and external fixation time in all patients were documented and analyzed. The Johner-Wruhs criteria were used for the final clinical outcomes evaluation at the last clinical visit.

RESULTS

Satisfactory reduction and bone union were achieved in all patients. There were no statistical significances between the two groups in the demographic data, original postoperative deformities, residual deformities after final correction, external fixation time, and the final clinical outcomes (P > 0.05). The mean number of repeated radiographs after the first radiographs (1.4 times) and mean time to the satisfactory reduction achieved (3.3 days) in patients with an additional foot ring used were all less than those without foot ring (2.4 times, 5.3 days) (P < 0.05).

CONCLUSIONS

The additional foot ring is a practical device to ensure the orthogonality of postoperative radiographs for the hexapod external fixator parameter measurement. Radiation exposure, duration of deformity correction, and cost for patients might be reduced due to the less repeated radiographs with the wrong position.

Intraoperative acute correction versus postoperative gradual correction for tibial shaft fractures with multiplanar posttraumatic deformities using the hexapod external fixator

BACKGROUND

The purpose of this study was to determine the differences in clinical outcomes, if any, between intraoperative acute correction and postoperative gradual correction for tibial shaft fractures with multiplanar posttraumatic deformities using the hexapod external fixator.

METHODS

We retrospectively analyzed 58 consecutive patients with tibial shaft fractures treated by the hexapod external fixator at our institution from January 2015 to April 2019. Twenty-three patients (Group I) underwent intraoperative acute correction, from January 2015 to October 2016. Starting in November 2016, the other 35 patients (Group II) all underwent postoperative gradual correction. The demographic data, operation duration, original residual deformities before correction, residual deformities after correction, and external fixation time were collected and analyzed. The clinical outcomes were evaluated by the Johner-Wruhs criteria at the last clinical visit.

RESULTS

All patients achieved complete bone union with a mean time of 28.7 ± 4.6 weeks (range 21 to 37 weeks) in Group I and 27.9 ± 4.8 weeks (range 19 to 38 weeks) in Group II (P > 0.05). The operation duration in Group I (88.9 ± 7.7 min) was longer than that in Group II (61.9 ± 8.4 min), and there was a statistically significant difference (P < 0.05). There were no statistically significant differences between the two groups in original residual deformities before correction and residual deformities after correction (P > 0.05). The rate of postoperative complication was similar between the two groups. There was no statistical significance in demographic data and clinical outcomes between the two groups (P > 0.05).

CONCLUSIONS

There is no difference in clinical outcomes between intraoperative acute correction and postoperative gradual correction for tibial shaft fractures with multiplanar posttraumatic deformities using the hexapod external fixator. Postoperative gradual correction may shorten the duration in the operation room and decrease the potential intraoperative risk.

Accuracy of radiographic measurement techniques for the Taylor spatial frame mounting parameters

Aim

The correction accuracy of the Taylor Spatial Frame (TSF) fixator depends considerably on the precise determination of the mounting parameters (MP). Incorrect parameters result in secondary deformities that require subsequent corrections. Different techniques have been described to improve the precision of MP measurement, although exact calculation is reportedly impossible radiologically. The aim of this study was to investigate the accuracy of intraoperative and postoperative radiographic measurement methods compared to direct MP measurement from TSF bone mounting.

Methods

A tibial Sawbone® model was established with different origins and reference ring positions. First, reference MPs for each origin were measured directly on the frame and bone using a calibrated, digital vernier calliper. In total 150 MPs measured with three different radiographic measurement techniques were compared to the reference MPs: digital radiographic measurements were performed using soft-copy PACS images without (method A) and with (method B) calibration and calibrated image intensifier images (method C).

Results

MPs measured from a non-calibrated X-ray image (method A) showed the highest variance compared to the reference MPs. A greater distance between the origin and the reference ring corresponded to less accurate MP measurements with method A. However, the MPs measured from calibrated X-ray images (method B) and calibrated image intensifier images (method C) were intercomparable (p = 0.226) and showed only minor differences compared to the reference values but significant differences to method A (p < 0,001).

Conclusion

The results demonstrate that MPs can be accurately measured with radiographic techniques when using calibration markers and a software calibration tool, thus minimizing the source of error and improving the quality of correction.

Long bone fracture reduction and deformity correction using the hexapod external fixator with a new method: a feasible study and preliminary results

Background

The hexapod external fixator (HEF), such as the Taylor spatial frame (TSF), offering the ability of multidirectional deformities correction without changing the structure, whereas there are so many parameters for surgeons to measure and subjective errors will occur inevitably. The purpose of this study was to evaluate the effectiveness of a new method based on computer-assisted three-dimensional (3D) reconstruction and hexapod external fixator for long bone fracture reduction and deformity correction without calculating the parameters needed by the traditional usage.

Methods

This retrospective study consists of 25 patients with high-energy tibial diaphyseal fractures treated by the HEF at our institution from January 2016 to June 2018, including 22 males and 3 females with a mean age of 42 years (range 14–63 years). Hexapod external fixator treatments were conducted to manage the multiplanar posttraumatic deformities with/without poor soft-tissue that were not suitable for internal fixation. Computer-assisted 3D reconstruction and trajectory planning of the reduction by Mimics were applied to perform virtual fracture reduction and deformity correction. The electronic prescription derived from the length changes of the six struts were calculated by SolidWorks. Fracture reduction was conducted by adjusting the lengths of the six struts according to the electronic prescription. Effectiveness was evaluated by the standard anteroposterior (AP) and lateral X-rays after reduction.

Results

All patients acquired excellent functional reduction and achieved bone union in our study. After correction, the mean translation (1.0 ± 1.1 mm) and angulation (0.8 ± 1.2°) on the coronal plane, mean translation (0.8 ± 1.0 mm) and angulation (0.3 ± 0.8°) on the sagittal plane were all less than those (6.1 ± 4.9 mm, 5.2 ± 3.2°, 4.2 ± 3.5 mm, 4.0 ± 2.5°) before correction (P < 0.05).

Conclusions

The computer-assisted three-dimensional reconstruction and hexapod external fixator-based method allows surgeons to conduct long bone fracture reduction and deformity correction without calculating the parameters needed by the traditional usage. This method is suggested to apply in those unusually complex cases with extensive soft tissue damage and where internal fixation is impossible or inadvisable.

Improving radiographic imaging for circular frames: the Cambridge experience

INTRODUCTION

Limb reconstruction using circular frames requires complex accurate measurements to achieve correction of mechanical bone axis. Inadequate imaging could ultimately lead to poor clinical outcome. Therefore, radiographs should be obtained in a standardised manner to yield accurate results. Our aim is to improve the effectiveness of post-operative imaging by obtaining precise examinations and improving the accuracy of frame correction; therefore, reducing technical repeats, radiation exposure, time waste in clinic, and achieving cost effectiveness.

METHODS

We implemented a simple technique for obtaining adequate imaging using standard X-ray equipment. This technique was introduced to the radiographers in the radiology department to image patients with circular frames. Images were taken by obtaining a field of view using the X-ray machine cone of light that is orthogonal to the location of interest in both the antero-posterior (AP) and lateral planes. We compared the quality of radiographs, number of repeated X-rays and radiation dose both before and after implementing our protocol RESULTS: We assessed 54 consultations before and 63 consultations after the implementation of our protocol. The results showed a reduction in inadequate radiographs from 78% to 13% department at Addenbrooke's Hospital at a statistical significance of p < 0.00001. In addition, we found a potential radiation dose reduction of 2.7-0.32mSev between the two cohorts. Our results indicate that there would also be a reduction in the cost to the department as well as time spent repeating inaccurate radiographs.

CONCLUSION

We have been able to achieve a significant improvement in the quality of post-operative radiographic imaging and have expanded its use to adult frame patients with a background of traumatic or infectious aetiologies.

Application of elliptic registration and three-dimensional reconstruction in the postoperative measurement of Taylor spatial frame parameters

BACKGROUND

The Taylor spatial frame offered the ability of simultaneous correction of the multidirectional deformities without the need to change the frame, and it was widely used for limb lengthening, deformity correction, and fracture reduction in recent years. There are still some inherent limitations that can affect the accuracy of correction, especially for the measurement of the mounting and rotational parameters. The purpose of our study was to propose some more precise postoperative measurement of Taylor spatial frame (TSF) parameters by application of elliptic registration and three-dimensional reconstruction.

METHODS

This retrospectively study included 28 trauma patients who suffered tibial fracture treated by the TSF at our institution from January 2016 to January 2018, including 25 males and 3 females with a mean age of 43 years (range 14-70 years). We conducted standard full-length anteroposterior and lateral X-rays of the injured extremity and the computed tomographic scans of the bilateral extremities after the operation. Elliptic registration and 3D reconstruction were used to calculate the parameters by two types of software Mimics and CorelDRAW. Correction of the deformity was conducted by adjusting the struts of the TSF according to the electronic prescription. The standard anteroposterior and lateral X-rays after correction were taken to evaluate the effectiveness.

RESULTS

All patients acquired functional reduction, which was evaluated by digital radiography. The mean coronal plane translation(1.9±2.2 mm), coronal plane angulation(1.2±1.0°), sagittal plane translation(2.7±2.1 mm), and sagittal plane angulation(1.2±1.0°) after correction were all less than those(5.5±4.6 mm, 4.9±3.9°, 4.7±4.0 mm, 2.7±2.3°) before correction.

CONCLUSIONS

The TSF system can correct the 6-axis deformities simultaneously with the accurate parameters. Elliptic registration and three-dimensional reconstruction are alternative methods to precisely measure the parameters needed by the TSF system, especially for the mounting and rotational parameters of unusually complex cases.

The silhouette technique: improving post-operative radiographs for planning of correction with a hexapod external fixator

Correction of deformity of a bone through use of a hexapod external fixator requires clear definition of the relationship between the bone and the frame. Achieving adequate orthogonal calibrated radiographs for this aim, with minimum X-ray exposure, can prove a challenge in the radiography suite. We describe a simple technique for obtaining adequate imaging, without the use of additional equipment. Introduction of the technique to our department has demonstrated an improvement in the adequacy of planning radiographs and a reduction in the requirement for repeat imaging.

Treatment of open fractures with a computer-assisted external fixator system without the use of fluoroscopy

BACKGROUND

Developed for the treatment of deformity correction, computer-assisted circular external fixators in recent years have also been used for fracture fixation. In this study, we aimed to present the efficacy of computer-assisted circular external fixator use in open long bone fractures with our new technique.

METHODS

Between February 2013 and June 2014, 14 patients (mean age 24.5 (range 20-32)) with open tibial or femoral open fractures were treated with the computer-assisted fixation system (Spider Frame-Tasarım Medikal, Istanbul, Turkey). In all patients, appropriate positions of the rings and Schanz screws were determined by measurements on preoperative radiographs. The length of the Schanz screws were determined by depth measure marks on drill bits. Obvious deformities were corrected intraoperatively by manipulations, but residual deformities were corrected by a software program (Spiderfix, Tasarım Medikal, Istanbul, Turkey). We did not use fluoroscopy during the procedures.

RESULTS

Ten patients had tibia diaphyseal and four patients had femoral diaphyseal fractures. Mean surgical time was 24.2 (range 18-28) min. Average follow-up time was 10.2 (range 9-14) months. Mean time for deformity correction was 3.1 (2-5) days. Complete union was observed in all patients with a mean of 4.9 (range 3-9) months. There were two grade 2 pin site infections treated with oral antibiotherapy and pin site care. We did not detect any Schanz screw breakage, loosening, deep infection, nonunion, or malunion.

CONCLUSIONS

Computer-assisted external fixation systems can be used in the treatment of open fractures, and they provide the chance for acute or gradual correction. Preoperative planning and assistant devices with depth measures may decrease the procedure time and the need for fluoroscopy use.

[Correction of posttraumatic lower leg deformities using the Taylor Spatial Frame]

OBJECTIVE

Correction of posttraumatic lower leg deformities using percutaneous osteotomy, external fixation with a ring fixator, and computer-assisted gradual correction with the Taylor Spatial Frame (TSF).

INDICATIONS

Posttraumatic lower leg deformities not suitable for acute correction and internal fixation or deformities that are suitable but have a significantly increased risk for complications: deformities with poor soft tissue coverage, rigid deformities that require gradual correction, complex mulitplanar deformities, deformities with shortening, and periarticular juvenile deformities.

CONTRAINDICATIONS

Posttraumatic lower leg deformities which are suitable for acute correction and internal fixation are also suitable for deformity correction using the TSF. In these cases, however, we recommend acute correction and internal fixation in order to improve the patient comfort. Lack of patient compliance for self-contained correction and pin care.

SURGICAL TECHNIQUE

Percutaneous fixation of the TSF rings to the main fragments using transosseous K-wires and half pins (hybrid fixation). Percutaneous osteotomy of the tibia either by drilling across both cortices and completion of the osteotomy using an osteotome (DeBastiani method) or by using the Gigli saw with preservation of the periostal envelope. Connection of both rings with six oblique telescopic struts via universal joints (hexapod platform). Computer-assisted planning of the correction.

POSTOPERATIVE MANAGEMENT

Gradual postoperative correction of the deformity by changing the strut lengths according to the correction plan. Strut changes, if required. Osseous consolidation of the osteotomy site with the TSF or revision to internal fixation.

RESULTS

The correction of posttraumatic lower leg deformities using the TSF was performed in 6 cases. The mean deformity was 15° (12-22°) in the frontal plane and 6° (4-8°) in the sagittal plane. The correction time was 19 days (14-22 days). The deviation between planned and achieved correction was 0-3° in the frontal plane and 0-2° in the sagittal plane. The osseous consolidation of the osteotomy site was carried out in the TSF in 5 cases with a mean external fixation time of 112 days (94-134 days). In one case, the TSF was removed after the correction and the osteotomy site was fixed using an intramedullary nail. Pin site infections were observed in 3 cases. There were no further complications. The treatment goal was achieved in all cases. The examination at final follow-up was performed after 1 year. All patients were able to walk without walking aids and with no pain at that time. They were able to perform all of their activities of the daily life and their leisure activities without limitations.

Intentional deformation and closure of soft tissue defect in open tibial fractures with a taylor spatial frame--a simple technique

OBJECTIVES

We describe a way of using Taylor spatial frames (TSFs) for acute deformation of Gustilo IIIB tibial fractures and infected tibial nonunions to close the soft tissue defects and to gradually restore anatomical alignment. We use the Direct Scheduler Utility module of the web-based software for TSFs to successfully restore the anatomical alignment.

DESIGN

We report a case series of the above technique.

SETTING

Care was carried out at a tertiary referral center for limb reconstruction.

PATIENTS

Seven consecutive patients with significant soft tissue loss after tibial fractures were treated.

INTERVENTION

Defects were closed with acute deformation of the fracture followed by gradual correction to anatomical alignment with a 2-ring TSF.

MAIN OUTCOME MEASUREMENT

Successful closure of the soft tissue defect was our primary outcome measure.

RESULTS

Soft tissue defects ranged from 3 to 10 cm. All healed without additional plastic surgery to cover the exposed tibia. Only 1 patient required an additional TSF prescription to achieve anatomical alignment.

CONCLUSIONS

The use of the Direct Scheduler module of the web-based TSF software allows the complete correction of complex deformities without the need for obtaining complex mounting and frame parameters. We achieved successful closure of soft tissue defects and restored the anatomical tibial alignment in all our cases.