Limb lengthening and deformity correction in children with abnormal bone

Beyond the gut: spectrum of magnetic surgery devices

Since the 1970s, magnetic force has been used to augment modern surgical techniques with the aims of minimizing surgical trauma and optimizing minimally-invasive systems. The majority of current clinical applications for magnetic surgery are largely centered around gastrointestinal uses-such as gastrointestinal or bilioenteric anastomosis creation, stricturoplasty, sphincter augmentation, and the guidance of nasoenteric feeding tubes. However, as the field of magnetic surgery continues to advance, the development and clinical implementation of magnetic devices has expanded to treat a variety of non-gastrointestinal disorders including musculoskeletal (pectus excavatum, scoliosis), respiratory (obstructive sleep apnea), cardiovascular (coronary artery stenosis, end-stage renal disease), and genitourinary (stricture, nephrolithiasis) conditions. The purpose of this review is to discuss the current state of innovative magnetic surgical devices under clinical investigation or commercially available for the treatment of non-gastrointestinal disorders.

Growth Arrest in Type IV Osteogenesis Imperfecta After Fassier-Duval Rod Insertion Treated by a Lengthening Magnetic Intramedullary Nail: A Case Report

CASE

A child with Type IV Osteogenesis Imperfecta (OI) sustained a growth arrest of the distal femur after fixation of a left femur fracture with a Fassier-Duval expanding rod at 3 years old. Despite bar resection with fat interposition, the discrepancy progressed to 7.5 cm at maturity. Because the femur had grown to a sufficient diameter, he underwent successful lengthening with a magnetic intramedullary rod.

CONCLUSION

Although it is a potential complication, growth arrest has not been reported in association with placement of an expanding nail in a child with osteogenesis imperfecta. This case illustrates this rare complication and treatment using a magnetic intramedullary rod.

Preliminary Results of Bone Lengthening over Telescopic Titanium Intramedullary Rod

Background

Limb lengthening and deformity correction in patients with abnormal bone associating fragility often require an approach combining methods of external and internal fixation. This study demonstrates results of simultaneous application of external fixator, and telescopic rod for femoral lengthening and deformity correction in three children with osteogenesis imperfecta or severe form of Ollier's disease.

Materials and Methods

Three patients (two boys with Ollier's disease and a girl with osteogenesis imperfecta, type I) were operated on for femoral lengthening with combined technique associating Ilizarov frame and titanium telescopic intramedullary rodding.

Results

Planned amount of lengthening and deformity correction were achieved for all patients. We found neither rod bending nor pull out of threaded tips. There was no difficulty of expanding of telescopic intramedullary rods made of titanium alloy during distraction phase of lengthening procedure.

Conclusion

This short series proved feasibility of performing one-stage surgery with external frame and telescopic rodding in limb lengthening. The technique of telescopic rods in lengthening procedure is promising method requiring meticulous insertion of rod in centralized positioning in epiphysis. Acute alignment of the segment been elongating should be achieved at surgery. No any progressive angular deformity correction in postoperative period is authorized in order to avoid bending of telescopic rod. This combined approach does not affect bone healing.

An Interference Inspection Algorithm of Limb and Hexapod Frame in the Treatment of Lower Limb Deformity

The Ortho-SUV frame is an innovative hexapod widely used in orthopedics for managing fractures and deformities. Avoidance of limb-frame interference is essential to verify the implementability of the pre-planned correction trajectory, as well as to maintain the continuity and security of the correction strategy. In this study, a novel interference inspection algorithm is developed to investigate the interaction of the limb and hexapod frame in the treatment of lower limb deformities. The algorithm is built on a minimum distance model of the cone frustum busbar and cylindrical axis using vector analysis. A pre-defined trajectory is generated by Cartesian coordinate path control. Subsequently, an interference case is performed through numerical simulation and motion simulation. The results show that the conclusion of numerical simulation and motion simulation are consistent, which prove the feasibility of the algorithm. The results also show that it is possible to identify the riskiest struts, which are prone to interfere with the limb, and the riskiest positions. The proposed algorithm can support the clinician in selecting the suitable frame configuration to avoid interference. The algorithm solves the problem that the interference can only be judged by clinical observation in the clinic.

Limb lengthening with PRECICE magnetic nail in pediatric patients: A systematic review

BACKGROUND

Limb lengthening techniques play an increasingly important role in the pediatric orthopedic field. The principles of the osteogenesis distraction bonded traditionally with external fixators; however, the recent deployment of fully implantable systems has been able to overcome severities related to external fixators. The PRECICE^® is an implantable limb lengthening intramedullary nail system that is remotely controlled and magnetically driven.

AIM

To review the current literature available on this matter in order to assess the PRECICE clinical and radiological outcomes and its possible complications in a population of pediatric patients undergoing limb lengthening.

METHODS

Only five studies met the inclusion criteria and were consequently included in the review for a total of 131 patients and 135 femurs. The clinical and radiological outcomes of interest were: the main lengthening obtained, the distraction rate, the period of time to full weight bearing, the consolidation index, and the Association for the Study and Application of Methods of Ilizarov score.

RESULTS

In conclusion, data collected from the articles under investigation were comparable with the exception of the consolidation index. Unfortunately, the study population was too small and the patients’ follow-up was too short to make definitive conclusions.

CONCLUSION

This review shows that the PRECICE Nail System is still a therapeutic challenge in limb lengthening for pediatric orthopedic surgeons; however, careful pre-operative planning and an accurate surgical technique could allow the correction of more complex deformities with a low rate of complications.

International recognition of the Ilizarov bone reconstruction techniques: Current practice and research (dedicated to 100th birthday of G. A. Ilizarov)

The Ilizarov method is one of the current methods used in bone reconstruction. It originated in the middle of the past century and comprises a number of bone reconstruction techniques executed with a ring external fixator developed by Ilizarov GA. Its main merits are viable new bone formation through distraction osteogenesis, high union rates and functional use of the limb throughout the course of treatment. The study of the phenomenon of distraction osteogenesis induced by tension stress with the Ilizarov apparatus was the impetus for advancement in bone reconstruction surgery. Since then, the original method has been used along with a number of its modifications developed due to emergence of new fixation devices and techniques of their application such as hexapod external fixators and motorized intramedullary lengthening nails. They gave rise to a relatively new orthopedic subspecialty termed “limb lengthening and reconstruction surgery”. Based on a comprehensive literature search, we summarized the recent clinical practice and research in bone reconstruction by the Ilizarov method with a special focus on its modification and recognition by the world orthopedic community. The international influence of the Ilizarov method was reviewed in regard to the origin country of the authors and journal’s rating. The Ilizarov method and other techniques based on distraction osteogenesis have been used in many countries and on all populated continents. It proves its international significance and confirms the greatest contribution of Ilizarov GA to bone reconstruction surgery.

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.

[Correction of complex defomities around the Knee Joint]

Complex deformities around the knee joint are usually severe and have several aetiologies. They can be present in one or more planes, with variations in severity between planes. The occurrence and progression of the deformity can be influenced by local and systemic factors. Several types of osteotomies and fixation methods are available to correct these complex deformities. The selection of the osteotomy used to correct a deformity depends on the type of deformity, its severity and its aetiology. Therefore, precise planning taking into consideration the above factors is necessary to achieve the goal.

Does the management of osteofibrous dysplasia of the tibia and fibula in children should be tailored to the extent and location of the lesion? A case control study investigating different surgical options

BACKGROUND

Osteofibrous dysplasia (OFD) is a rare non neoplastic, self-limited intracortical fibro-osseous lesion that most commonly affects the diaphysis of the tibia and fibula of children, the best treatment is still debated. Therefore we performed a retrospective study in children mostly under 10 years old with OFD aiming to determine whether early surgery is necessary and which is the best treatment.

HYPOTHESIS

Symptomatic OFD lesions should be treated proactively, and appropriate treatment can achieve favorable outcome.

METHODS

We retrospectively reviewed 23 patients with OFD of the tibia (n=22) and fibula. Management varied according to the severity of symptoms (deformity, pain or pathological fracture) and the extent of the lesion. Cases were divided into four groups (Gr.): Gr. 1: observation (n=4); Gr. 2: curettage and allograft (n=6); Gr. 3: curettage, allograft and elastic stable intramedullary nailing (ESIN) fixation (n=9); Gr. 4: extra-periosteal resection and bone transport (n=5). One patient received two different treatments successively (23 patients and 24 cases). All patients had regular clinical and radiographic follow-up to assess bone consolidation and complications.

RESULTS

In Gr. 1, four asymptomatic patients underwent observation after open biopsy. Gr. 4 had the lowest local recurrence rate: 0 cases (0%) vs. 4 (66.7%; Gr. 2) vs. 1 (11.1%; Gr. 3) (p=0.002), incidence of deformity: 0 case (0%) vs. 0 (0%; Gr. 2) vs. 3 (50%; Gr. 3) (p=0.023), and pathological fracture: 0 case (0%) vs. 0 (0%; Gr. 2) vs. 1 (16.7%; Gr. 3) (p=0.006), although the consolidation time was longer: 6.8 vs. 2 (Gr. 2) vs. 2.7 months (Gr. 3) (p=0.017) and the rate of complication was higher than those of Gr. 2 and Gr. 3 (p<0.05). Gr. 3 had a lower local recurrence rate: 1 case (11.1%) vs. 4 cases (66.7%) (p=0.002), incidence of deformity: 0 case (0%) vs. 3 cases (50%) (p=0.023), and pathological fracture: 0 case vs. 1 case (16.7%) (p=0.006) than Gr. 2.

DISCUSSION

Open biopsy is an important step in the management of patients with imaging suggestive of OFD in order to rule out Adamantinoma and other bone tumors or infection. Observation should be reserved for asymptomatic patients, while surgical treatment is indicated in patients with persistent pain, pathological fracture or significant deformity of the tibia. ESIN is a valid option to preserve the anatomical axis of the tibia in symptomatic patients with lesions of limited size; large circumferential lesions or recurrence can be managed by extra-periosteal resection and bone transport, although the complication rate can be relatively high.

LEVEL OF EVIDENCE

III; case control study.

Limb Length Discrepancy and Angular Deformity due to Benign Bone Tumors and Tumor-like Lesions

Benign bone tumors and tumor-like lesions are frequently diagnosed in children and adolescents. The immature skeleton is at risk for growth disturbances and deformity because of the effects of the lesions on normal bone architecture and the physis. The development, manifestation, and severity of the limb length inequality and deformity differs between the various bone pathologies. Distraction osteogenesis, osteotomy, and guided growth are key tools in the treatment of limb inequality and deformity using a combination of external and internal fixation devices.

Lower limb lengthening and deformity correction in polyostotic fibrous dysplasia using external fixation and flexible intramedullary nailing

The study describes preliminary experience of the use of external fixators for limb lengthening and deformity correction in combination with flexible intramedullary nailing in management of polyostotic fibrous dysplasia.

Patients and methods

The retrospective study included 8 patients (mean age 11.6 ± 3.38 years; range 7-17 years) with polyostotic fibrous dysplasia operated on using external circular frame and flexible intramedullary nailing. Mean follow-up was 2.6 years. Surgical technique consisted of percutaneous osteotomy of a segment and application of circular external frame. The intramedullary nailing was done using two bent nails. Hydroxyapatite-coated nails were applied in three patients; five patients had titanium nails. Amount of lengthening (cm and %), amount of deformity correction, duration of external fixator use, index of external fixation, "nail/medullary canal at narrowest site" ratio, "nail-medullary canal at osteotomy site" ratio were analyzed. Results and complications were assessed according to Lascombes's classification.

Results

The mean amount of lengthening was 4.5 cm (or 13.7 ± 6.0% per segment). This gave a mean external fixation index of 32.5 ± 13.97 days/cm. The mean ratio of IM nail diameter/medullary canal diameter at the narrowest site was 0.22 ± 0.07 (range, 0.125-0.3 mm). No migration of IM nails into medullary canal were noticed. But in one case there was external migration of Ti-nail. In a year after frame removal, the results of treatment were classified as grade I in 7 cases and IIb in one case.At the latest follow-up control, mechanical axis deviation was found within normal limits in six patients. Two patients had excessive MAD of 11 and 28 mm. In the first case a partial varus deformity recurrence occurred at middle shaft site where a large dysplastic zone was presented. In the second case, a specific shepherd's crook deformity developed and caused excessive MAD. Mean lower limb length discrepancy varied from 1 to 15 mm.

Conclusion

There are advantages of using elastic intramedullary nailing and external fixation in the treatment of limb length discrepancy and deformity of long bones in patients with PFD. This strategy ensures reduced external fixation time and high accuracy of alignment. Intramedullary nails left in situ, especially nails with HA-coating, seem to prevent deformity recurrence and stimulate remodeling in dysplastic fibrous zones.