Hexapod External Fixation of Tibia Fractures in Children

Biomechanical study of the stiffness of the femoral locking compression plate of an external fixator for lower tibial fractures

BACKGROUND

A locking compression plate (LCP) of the distal femur is used as an external fixator for lower tibial fractures. However, in clinical practice, the technique lacks a standardized approach and a strong biomechanical basis for its stability.

METHODS

In this paper, internal tibial LCP fixator (Group IT-44), external tibial LCP fixator (Group ET-44), external distal femoral LCP fixator (Group EF-44, group EF-33, group EF-22), and conventional external fixator (Group CEF-22) frames were used to fix unstable fracture models of the lower tibial segment, and anatomical studies were performed to standardize the operation as well as to assess the biomechanical stability and adjustability of the distal femoral LCP external fixator by biomechanical experiments.

RESULTS

It was found that the torsional and flexural stiffnesses of group EF-44 and group EF-33 were higher than those of group IT-44 and group ET-44 (p < 0.05); the flexural stiffness of group EF-22 was similar to that of group IT-44 (p > 0.05); and the compressive stiffness of all three EF groups was higher than that of group ET-44 (p < 0.05). In addition, the flexural and compressive stiffnesses of the three EF groups decreased with the decrease in the number of screws (p < 0.05), while the torsional stiffness of the three groups did not differ significantly between the two adjacent groups (p > 0.05). Group CEF-22 showed the highest stiffnesses, while group ET-44 had the lowest stiffnesses (P < 0.05).

CONCLUSIONS

The study shows that the distal femoral LCP has good biomechanical stability and adjustability and is superior to the tibial LCP as an external fixator for distal tibial fractures, as long as the technique is used in a standardized manner according to the anatomical studies in this article.

Unilateral External Fixator Combined with Lateral Auxiliary Frame for Ultimate Treatment of Tibia and Fibula Shaft Fractures with Poor Soft Tissue Conditions

Background

For severe soft tissue damage or open fracture, unilateral external fixation is one of the treatment choices. In the current study, a unilateral external fixator combined with a lateral auxiliary frame was used to treat tibia and fibula shaft fractures with poor soft tissue conditions to verify its feasibility for the ultimate treatment.

Methods

We retrospectively analyzed the patients with tibia and fibula shaft fractures who underwent unilateral external fixator combined with lateral auxiliary frame between December 2018 and October 2020. The clinical outcomes were recorded.

Results

31 patients with tibia and fibula shaft fractures who received unilateral external fixator combined with lateral auxiliary frame were included in the current study. Among them, 23 cases had closed fractures with poor soft tissue and 8 cases had Gastilo type I open fractures. The average duration of hospital stay was 7.3 ± 2.3 days. The causes of injury were traffic accidents in 15 cases (48.4%), fall from height in 7 cases (22.6%), crush injury in 5 cases (16.1%), and other causes in 4 cases (12.9%). During follow-up, the clinical healing time was 3.0 ± 0.85 months. Additionally, the infection rate of pin-tract and reoperation rate was 12.9% and 3.2%. Fortunately, all patients achieved fracture healing and recovered well without joint dysfunction and obvious claudication. The Johner-Wruh scores showed that 27 cases (87.1%) were “excellent” and 4 cases (12.9%) were “good.”

Conclusions

The unilateral external fixator combined with lateral auxiliary frame is an effective option for ultimate treatment of the tibia and fibula shaft fractures with poor soft tissue conditions.

Retrospective clinical outcomes in the definitive treatment of high-energy tibial diaphyseal fractures using hexapod external fixator versus monolateral external fixator

BACKGROUND

External fixation, which can preserve the biomechanical microenvironment of fracture healing, plays an important role in managing the high-energy fractures with poor surrounding soft tissues. The purpose of this study was to determine the differences of clinical outcomes, if any, between hexapod external fixator and monolateral external fixator in the definitive treatment of high-energy tibial diaphyseal fractures.

METHODS

A total of 53 patients with high-energy tibial diaphyseal fractures and definitively treated by the hexapod external fixator (HEF) or monolateral external fixator (MEF) were retrospectively collected and analyzed, from March 2015 to June 2019. There were 31 patients in the HEF treatment, and the other 22 patients were managed by the MEF. The demographic data, surgical duration, external fixation time, final radiological results, complications, and clinical outcomes were documented and analyzed. Difficulties that occurred during the treatment were classified according to Paley. The clinical outcomes were evaluated by the Association for the Study and Application of the Method of Ilizarov criteria (ASAMI) at the last clinical visit.

RESULTS

The mean surgical duration in the HEF group (62.4 ± 8.3 min) was shorter than that in the MEF group (91.4 ± 6.9 min) (P < 0.05). All patients acquired complete bone union finally. Patients in the HEF group (24.2 ± 3.1 weeks) underwent a shorter average external fixation time than that in the MEF group (26.3 ± 3.8 weeks) (P < 0.05). Satisfactory alignment was achieved in all patients without the need for remanipulation. The residual sagittal plane deformities in the HEF group were all less than that in the MEF group (P < 0.05). The complication rate was 35.5% in the HEF group, while 45.5% in the MEF group. There was no statistically significant difference between the two groups in ASAMI scores (P > 0.05).

CONCLUSION

There is no statistically significant difference in finally clinical outcomes between hexapod external fixator and monolateral external fixator in the definitive treatment of high-energy tibial diaphyseal fractures. The hexapod external fixation treatment is a superior effective method, including advantages of stable fixation, less surgical duration, postoperatively satisfactory fracture reduction, and fewer complications.

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.

An engineering review of external fixators

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Mechanical stability plays a key role in the effectiveness of external fixators.

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Strength and stiffness are the main factors which contributes towards stability.

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Modified configurations of linear, circular and hybrid fixators are investigated.

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Light weight composite materials are gradually replacing traditional metallic alloys.

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Existing research gaps in further optimizing external fixators are identified.

External Fixators are a common technique used to treat a variety of issues related to bones, predominantly due to its non-intrusive nature and versatility in terms of form and materials. While it is mainly used to treat open fractures, its other uses include limb lengthening, deformity correction, bone grafting, compression of non-unions and stabilization of dislocations. Its earliest use dates as far back as 400 BCE and has undergone significant improvements, focusing on both customization and optimization. These two aspects highlight the significance of complementing the orthopaedic requirements with engineering knowledge and its applications. Hence, this review paper aims to conduct an examination of recent developments of external fixators with a special focus on its structure, the usage of materials and biomechanical investigations using experimental and numerical techniques. The paper presents the existing level of engineering knowledge with regards to these aspects and identifies research gaps, which can improve the quality of the commonly used external fixators.

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.

Displaced diaphyseal tibia fractures managed by elastic stable intramedullary nailing with or without the use of intraoperative traction table during nail insertion: a comparative analysis of 160 patients

The use of an orthopedic traction table (OTT) during elastic stable intramedullary nailing (ESIN) in the management of displaced diaphyseal tibia fractures (DTFs) is controversial. The aim of this study was to evaluate the clinical and radiological outcome of children with displaced DTF managed by ESIN with and without the use of an OTT. Medical records were retrospectively reviewed for all pediatric patients sustaining DTF managed by ESIN from 2011 to 2019 at two different institutions. In all, 160 consecutive children with displaced DTF were recorded, of whom 80 underwent operative treatment by ESIN without OTT (group A), and 80 by ESIN with the use of an OTT and skeletal traction (group B). ESIN outcome measure scale, Beaty radiologic criteria and Radiographic Union Scale for Tibia fractures (RUST) score were used to evaluate the results. Average patient age at time of injury was 10.8 years (range 7-15). The mean follow-up was 55.8 months (range 12-96). All complications (2.5%) and poorer results according to ESIN outcome measure scale and Beaty radiological criteria were recorded among children managed with OTT. No complications related to pin insertion for skeletal traction were observed. Mean RUST score, length of surgery and cumulative time of radiation exposure were comparable between the two groups. Children with a displaced DTF treated by ESIN without the use of OTT showed superior results as there are no additional procedures (traction wire insertion and removal) decreased theater time and no complications with similar radiation dose.

External fixation versus elastic stable intramedullary nailing in the treatment of open tibial shaft fractures in children

Introduction

External fixator (EF) is a popular choice for open tibial fractures, but pin tract infection (PTI) and refracture are common complications. Elastic stable intramedullary nail (ESIN) has been reported in the treatment for open tibial fractures. This study aims to compare the clinical outcomes of EF vs. ESIN in the treatment for open tibial shaft fracture in children retrospectively.

Methods

Patients aged 5–11 years with Gustilo-Anderson II and IIIA tibial shaft fracture treated at our institute from January 2008 to January 2018 were reviewed retrospectively and categorized into EF and ESIN groups. Patients with pathological fracture, neuromuscular disorder, metabolic disease, previous tibial fracture or instrumentation, and polytrauma were excluded. Patients with follow-up < 24 months or incomplete medical records were also excluded.

Results

In all, 55 patients (33 males, 22 females) were included in the EF group, whereas 37 patients (21 males, 16 females) were included in the ESIN group. There was no statistically significant difference between the two groups concerning sex, age, body weight, duration from injury to surgery, Gustilo-Anderson (GA) classification, and concomitant injuries. There was no case of nonunion and malunion in either group. The angulation at the latest follow-up was higher in the EF group than the ESIN group (P < 0.01). The radiological union was faster in the ESIN group (7.0 ± 0.9 weeks) than those in the EF group (9.0 ± 2.2 weeks) (P < 0.01). Limb length discrepancy (LLD) was more in the EF group (12.1 ± 4.4, mm) than in the ESIN group (7.3 ± 4.3, mm) (P < 0.01).

Conclusion

ESIN is a viable option in selected patients of GA grade II and IIIA open tibial fractures with comparable clinical outcomes as external fixator. Pin tract infection is the most troublesome complication in the EF group while implant prominence is a nuisance in the ESIN group.

Application of unilateral external fixation by the "joystick technique" in the treatment of pediatric tibia shaft fractures: technical note

Background

The aims of current study were to present the clinical outcomes in patients with pediatric tibia shaft fractures who were treated with unilateral external fixation combined with joystick for fracture reduction and describe the details of our technique.

Methods

We retrospectively analyzed the patients with pediatric tibia shaft fractures who were treated with unilateral external fixation combined with joystick for fracture reduction between July 2018 and March 2020. The clinical outcomes were evaluated.

Results

A total of 23 patients were included in the current study with the average age of 8.0 years (ranged 4–14 years). The average duration of hospital and follow-up were 5.9 days (ranged 4–8 days) and 17.4 months (ranged 8–27 months), respectively. At postoperative 3 days, the visual analog scale (VAS) score was 3.1 ± 1.43, which was significantly lower than the preoperative score of 7.3 ± 1.5. Of these, 2 cases showed redness and swelling of pin-tract and exudation at postoperative 1 month, who improved after oral antibiotics without causing fixation failure. The average time to full weight-bearing without crutches was 5.1 weeks (ranged 3–8 weeks). All patients achieved fracture healing and good functional recovery. No complications including fixation failure, reoperation, epiphyseal injury occurred, infection around implants, vessel damage, nerve damage, and limitation of joint movement were observed. The Johner-Wruh scores showed that 21 cases (91.3%) were “excellent” and 2 cases (8.7%) were “good.”

Conclusions

This procedure had advantages of simple operation, minimum trauma, early recovery of lower limb function, and no risk of complications. It may provide a new choice for children with tibia shaft fractures who require surgical treatment.

Influence of parameter deviation on the closeness of the tibial limb and external fixator based on a novel collision detection algorithm

The Ortho-SUV frame (OSF) is a hexapod external fixator widely applied in orthopedics deformity correction. The possibility of collision between OSF's struts and the soft tissue is an essential but overlooked issue. To avoid the issue, a novel collision detection algorithm is established based on a cone-cylinder model of the tibial limb-strut interaction for detecting the closeness of the tibial limb and external fixator. The algorithm is constructed using the vector analysis based on the model of the minimum distance between the truncated cone generatrix and the cylinder axis. The motion simulation is performed on the overall alignment through the Solidworks-motion module to verify the feasibility of the algorithm. Subsequently, the installation parameter deviations of the bone-fixator system are described to investigate the influence of orientation and position deviation on the closeness of the tibial limb and external fixator through the numerical method. The investigation results show that the orientation deviation γ (around the z-axis), the position deviation τ₁ and τ₂ (along the x and y-axes, respectively) have greater sensitivity to closeness and the influence of multiple deviations on the closeness has the property of superposition. The proposed algorithm can assist clinicians to strictly design and appraise frame configurations prior to their application to avoid the collision between the external fixator and the limbs during the correction. It has great application significance in the development of computer-aided correction software.

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.

Management of high-energy tibial shaft fractures using the hexapod circular external fixator

Background

The hexapod external fixator (HEF) is increasingly used for high-energy tibial shaft fracture care as more general orthopedic surgeons are gaining expertise of this versatile device. The purpose of this study was to evaluate the clinical effectiveness of the HEF for definitive management in patients with high-energy tibial shaft fractures.

Methods

The study was conducted on 34 patients with tibial shaft fractures who were admitted or referred to our institution and consented to HEF treatment from Jan 2016 to June 2019, including 27 males and 7 females with a mean age of 39 years (range 18 to 65 years). Patients' clinical and radiological data, and the final clinical outcomes at a minimum of 12 months follow-up were collected and retrospectively analyzed. All complications were documented according to Paley’s classification. The clinical outcomes were evaluated using the Association for the Study and Application of the Method of Ilizarov criteria (ASAMI) at the last clinical visit.

Results

All patients remained in the HEF for a mean of 26 weeks (range 15 to 52 weeks) and acquired complete bone union. The satisfactory alignment was achieved in all patients, and all the patients were able to perform daily activities with no difficulty at the last clinical visit. Complications included pin tract infection (44%), delayed union (6%), nonunion (3%), and joint stiffness (3%). The ASAMI bony result was excellent in 31 patients and good in 3. The ASAMI functional result was excellent in 27 patients, good in 6, and fair in 1.

Conclusions

Definitive management using the hexapod external fixator is an alternative and effective method for high-energy tibial shaft fractures, including technical advantages of early trauma-control, the versatility of achieving excellent alignment, and the continuity of device until bone union.

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.

Can the TrueLok Hexapod System™ be used to accurately correct lower limb deformity in children?

INTRODUCTION

Progressive bone lengthening in children can be done using an external fixator, a lengthening nail, or plate with screws. The TrueLok Hexapod System™ (TL-HEX™) is the newest hexapod external fixator on the market. We hypothesized that the TL-HEX™ can accurately correct lower limb deformities in children. The goal of this study was to evaluate the clinical and radiographic outcomes after correcting lower limb deformities in children using the TL-HEX™ system.

MATERIAL AND METHODS

Data from 58 limbs that underwent bone lengthening with the TL-HEX™ were analyzed for this retrospective, single-center study. The average patient age was 11.4 years. The femur was lengthened in 23 limbs and the tibia in 35. The outcomes were evaluated using long leg standing radiographs preoperatively and at the final assessment. The variables of interest were the mechanical axis deviation (MAD), mechanical lateral distal femoral angle (mLDFA), mechanical lateral proximal tibia angle (mMPTA), healing index (HI) and accuracy of the correction. The complications were graded on a 4-point scale summarizing three broad goals: planned correction, duration of treatment and sequelae. The accuracy of the correction was defined as the difference between the planned correction and the actual correction achieved.

RESULTS

The mean HI was 37 days/cm. Significant correction was achieved for leg length discrepancy (LLD) (60 mm vs. 20 mm; p<0.01) and mLDFA (88.6° vs. 89.9°; p=0.04) but not the MAD (17.7 vs. 14.7; p= 0.17) or mMPTA (87.3 vs. 88.1; p=0.08). In the entire cohort, the difference from planned was 12.5 mm (p<0.01) for lengthening, 1.3° for the mLDFA (p=0.5) and 3° for the mMPTA (p=0.02). Relative to the initial goal, the mean lengthening achieved was 118%. In the sub-group where the plan did not need to be modified, the accuracy of the correction was better. There were 40 complications (69%).

CONCLUSION

The TL-HEX™ is an effective and accurate system. The complication rate associated with its use is the same as other hexapod external fixators. Surgeons and patients must be aware of the high complication rate, which may require the plan to be modified and could potentially compromise the outcome.

Management of Pediatric Tibial Shaft Fractures

Diaphyseal tibia fractures in the pediatric population have dynamic treatment strategies that depend on injury pattern, mechanism, patient skeletal maturity and size. Treatment strategies include closed reduction and cast immobilization, flexible nails, uniplanar or multiplanar external fixation or plate osteosynthesis. Accepted parameters for sagittal and coronal alignment vary based on age and potential for remodeling, although all fractures should have minimal rotational malalignment and less than 1 cm of shortening. Stable union generally occurs in 3 to 4 weeks for the common toddler's fracture and 6 to 8 weeks in other fracture patterns. Complications such as compartment syndrome are possible with both open and closed injuries, and nonunions, although rare, are more common in patients treated with external fixation or flexible nailing. Overall, treatment should be predicated on a full evaluation of the patient, fracture, local soft tissues, and any concomitant injuries.

Evidence-based update on the surgical treatment of pediatric tibial shaft fractures

PURPOSE OF REVIEW

To describe surgical treatment options for pediatric tibial shaft fractures which are the third most common pediatric long bone fracture. Management of these injuries is dictated by fracture location, fracture pattern, associated injuries, skeletal maturity, and other patient-specific factors. Although most pediatric tibial shaft fractures can be treated nonoperatively, this review provides an update on surgical treatment options when operative intervention is indicated.

RECENT FINDINGS

Advances in surgical implants and techniques affords a wide range of options for the surgical treatment of pediatric tibial shaft fractures. Flexible intramedullary nailing is gaining wide adoption for acute surgical treatment. Recent studies support cross-sectional imaging for further evaluation and scrutiny of fracture patterns suspicious for intraphyseal or intra-articular extension. Grade I open tibial shaft fractures may be safely treated with irrigation and debridement in the emergency department; however, no high-level comparative studies have been performed to make any definitive conclusions regarding the effectiveness of this treatment strategy.

SUMMARY

Tibial shaft fractures are common injuries in pediatric patients. Management is dictated by fracture location, fracture pattern, associated injuries, patient age, and other patient-specific factors. Surgical intervention is indicated for fractures that are open, irreducible, have failed nonoperative management, are associated with compartment syndrome, or in the multiply injured patient. Surgical treatment options include flexible intramedullary nailing, plate osteosynthesis, external fixation, and rigid intramedullary nailing. Recent literature has shown increased rates of flexible intramedullary nailing. All operative and nonoperative management options can result in complications including compartment syndrome, infection, delayed union, nonunion, malunion, limb length discrepancy, and symptomatic hardware. Most pediatric patients go on to uneventful union with excellent final outcomes and return to full activities.

Update on leg fractures in paediatric patients

Leg fractures are common and further increasing in prevalence in paediatric patients. The diagnosis is readily made in most cases. Choosing the best treatment is the main issue. Non-operative treatment is the reference standard for non-displaced or reducible and stable fractures but requires considerable expertise and close monitoring, as well as an immobilisation period that far exceeds 3 months in many cases. Some surgical teams therefore offer elastic stable intra-medullary nailing (ESIN) as an alternative to children who do not want to be immobilised for several months. Internal fixation is required for unstable or irreducible leg fractures. ESIN is often used as the first-line method, based on its very good risk/benefit ratio. For fractures that do not lend themselves to ESIN, optimal stabilisation can be achieved by choosing among the other available options (screw-plate fixation, rigid intra-medullary nailing or external fixation) on a case-by-case basis. Close monitoring during the first few days is crucial to ensure the early detection of compartment syndrome. The other complications and sequelae are non-specific.

Evaluation of the external fixator TrueLok Hexapod System for tibial deformity correction in children

BACKGROUND

Tibial deformities are common in paediatric orthopaedic practice. Correcting multiplanar tibial deformities associated with lower limb length discrepancy can be challenging. Hexapod external fixation with gradual correction has been proven effective in this situation.

OBJECTIVE

To assess clinical and radiological outcomes of gradual tibial deformity correction using the external fixator TL-HEX™ (Orthofix) in children.

HYPOTHESIS

TL-HEX™ is effective in correcting tibial deformities in children.

PATIENTS AND METHODS

This multicentre retrospective study collected data from the medical files of 26 patients with 31 tibial deformities treated by gradual correction using TL-HEX™. The tibial deformities were due to congenital defects in 11 (35%) cases, Blount's disease in 9 (29%) cases, pseudo-achondroplasia in 4 (13%) cases, and other causes in 7 (23%) cases. Mean age at surgery was 11.9 years. In each patient, antero-posterior long leg radiographs obtained pre-operatively and at last follow-up were used to measure parameters including the mechanical axis deviation (MAD), medial proximal tibia angle (MPTA), and leg length discrepancy (LLD).

RESULTS

The mean healing index was 39.3 days/cm (range, 32-58 days/cm). The overall complication rate was 61%, with 11 unplanned visits. Superficial pin tract infection was the most common complication. Significant decreases between the pre-operative and post-operative assessments occurred in mean MAD (from 32.1mm to 10.2mm, P<0.001) and mean LLD (from 36.8mm to 9.1mm, P<0.001). Patients who underwent proximal tibial osteotomy had a significant improvement in MPTA, from 80.6° to 88.5° (P=0.006).

DISCUSSION

This is the first clinical study specifically designed to assess outcomes of TL-HEX™ limb lengthening and deformity correction. MAD, MPTA, and LLD were significantly improved at last follow-up. MAD was greater than 10mm at last follow-up in only 11patients. The complication rate was similar to those reported with other external fixators. TL-HEX™ is effective in the management of tibial deformities in children.

LEVEL OF EVIDENCE

IV (retrospective study).

Clinical utility of the Taylor spatial frame for limb deformities

The Taylor spatial frame (TSF) is a hexapod external fixator that can correct six-axis deformities. The mathematical base of all hexapod systems is projective geometry, which describes complex repositioning of an object in space. The Taylor brothers developed one of the first six-axis correction systems, which is known today as TSF. Over the years, this system has become the most used six-axis deformity correction device. In this review, we describe the history behind TSF development, and describe the principles and clinical utility for application of the TSF in different settings, such as acute trauma, malunions, and various deformities of the lower and upper limb.