Cesar G. Fontecha

Vascularized Fibular Periosteal Graft: A New Technique to Enhance Bone Union in Children

Background: The periosteum in children has strong osteogenic power and is quite thick, facilitating procurement. However, it has been rarely used as a vascularized flap to enhance bone union in this age range. The purpose of this study is to assess the effectiveness of a new vascularized periosteal flap harvested from the fibula for the enhancement of bone union in the pediatric age. Methods: Thirteen vascularized fibular periosteal grafts were used in 12 children, mean age 12.6 years. Indications included the prevention of bone allograft-host junction nonunion and treatment of recalcitrant bone nonunion. In 9 instances, the periosteal flap was harvested as a free flap and in 4 as a pedicled flap. Serial radiographs and computed tomography scans were used to evaluate the progression of callus formation and bone healing. Results: All flaps were successful in promoting bone healing and achieving bone union in a mean time of 2.8 months for metaphyseal junctions and 7.1 months for diaphyseal ones, except for 1 case, which initially failed due to a pedicle torsion. It was then resolved with a second vascularized fibular periosteal grafts, with complete union after 5 months. Conclusions: Transfer of a vascularized fibular periosteal flap, either pedicled or as a free flap, is an effective treatment to enhance bone union in children in biologically unfavorable scenarios. The properties of periosteal tissue in the pediatric age are unique and its use in bone union enhancement permits new reconstructive strategies in children different from those described in adults. Level of Evidence: IV.

Inert patch with bioadhesive for gentle foetal surgery of myelomeningocele in a sheep model

OBJECTIVE Current techniques used in foetal myelomeningocele repair can require considerable manipulation of fragile foetal tissues to obtain tension-free closure. The aim of this study was to assess the feasibility of a simple foetal coverage method without foetal tissue manipulation to provide closure of the neural tube defect in myelomeningocele. STUDY DESIGN This is an experimental study performed in 15 foetal sheep with lumbar myelomeningocele, surgically created on day 75 of gestation. Five foetuses remained untreated. Ten underwent coverage with inert sheeting (5 Silastic; 5 Silastic+Marlex) secured by surgical tissue adhesive without suturing on day 95; none of them underwent foetal muscle or skin manipulation. Clinical and subsequent histological examinations were performed at 48h after birth. The Chi-square, Fisher exact, and Mann-Whitney U tests, when appropriate, were used for the comparisons. RESULTS The mean operating time for foetal coverage was 7.1 (SD=1.6)min. All untreated animals were unable to walk, had sphincter incontinence, showed an open defect, histological spinal cord damage, and a large Chiari malformation. All covered animals were able to walk, had sphincter continence, showed almost complete closure of the defect with regeneration of several soft tissue layers, and minimum Chiari malformation. CONCLUSION In a surgical myelomeningocele model in sheep, a simple, fast and gentle coverage method using a sealed patch avoids foetal tissue manipulation and enables adequate closure of the neural tube defect, providing regeneration of several tissue layers that protect the spinal cord, and significantly reducing Chiari II malformation.

Single-Access Fetal Endoscopy (SAFE) for myelomeningocele in sheep model I: amniotic carbon dioxide gas approach

BackgroundThis study aimed to assess the feasibility of single-access fetal endoscopy (SAFE) for the management of myelomeningocele (MMC) using intrauterine carbon dioxide as a distension medium in a sheep model.MethodsThis prospective experimental case-control study investigated 12 lamb fetuses that had a myelomeningocele-like defect surgically created on the 75th day of gestation. Four fetuses remained untreated (control group), and eight fetuses had MMC repair using two fetoscopic approaches with carbon dioxide used to distend the amniotic cavity. A collagen patch was placed over the defect and secured with surgical sealant. Four animals had a two-port fetoscopic procedure, and four animals had SAFE. Clinical and pathologic studies were performed after delivery.ResultsThis study confirmed the validity of the animal MMC model. None of the control animals was able to stand or walk, and all had a significant defect in the lumbar area with continuous leakage of cerebrospinal fluid, ventriculomegaly, and a Chiari-II malformation. All the treated animals, independently of the number of ports used in the repair, were able to walk and had a closed defect with resolution of the Chiari malformation.ConclusionsThe SAFE patch and glue coverage of surgically created fetal MMC is feasible and effective in restoring gross neurologic function in the fetal lamb model.

Fetoscopic release of extremity amniotic bands with risk of amputation.

With the advent of less-invasive fetal surgery techniques, nonlethal disorders are considered amenable to intrauterine treatment. Extremity amniotic band syndrome fulfils the criteria of intrauterine disorders conformable with fetal treatment: capability of prenatal diagnosis and severity. We report 2 cases of extremity amniotic bands with risk of limb amputation released fetoscopically with YAG laser.

Maldevelopment of the cerebral cortex in the surgically induced model of myelomeningocele: implications for fetal neurosurgery.

PURPOSE The purpose of this study is to describe the malformations of cortical development detected in a model of cerebrospinal fluid (CSF) leakage and the influence of surgical closure technique on developmental outcome. METHODS Using a surgically induced model of myelomeningocele (MMC) in sheep, we studied the effects of different repair methods upon the development of hydrocephalus, the presence of the Arnold-Chiari II (AC-II) hindbrain malformation, and cerebral cortex developmental anomalies using gross and histologic (hematoxylin and eosin and Nissl staining) study techniques. RESULTS A malformed cerebral cortex, including 2 anomalous cortical folding patterns, and lower brain weights were observed in the untreated animals. Hydrocephalus and AC-II malformations were also found in this group. These malformations were mostly prevented with prenatal 2-layer closure. CONCLUSIONS Cerebral cortical malformations and hydrocephalus, in addition to the AC-II hindbrain malformation, are disorders caused by fetal CSF leakage. These malformations were prevented with the technique of MMC closure currently used in humans. Both observations magnify the importance of the second hit associated with chronic CSF leakage, in addition to the primary defect causing the MMC, in the development of the malformation complex.

The role of muscle imbalance in the pathogenesis of shoulder contracture after neonatal brachial plexus palsy: a study in a rat model

BACKGROUND An internal rotation contracture of the shoulder is common after neonatal brachial plexus injuries due to subscapularis shortening and atrophy. It has been explained by 2 theories: muscle denervation and muscle imbalance between the internal and external rotators of the shoulder. The goal of this study was to test the hypothesis that muscle imbalance alone could cause subscapularis changes and shoulder contracture. MATERIALS AND METHODS We performed selective neurectomy of the suprascapular nerve in 15 newborn rats to denervate only the supraspinatus and the infraspinatus muscles, leaving the subscapularis muscle intact. After 4 weeks, passive shoulder external rotation was measured and a 7.2-T magnetic resonance imaging scan of the shoulders was used to determine changes in the infraspinatus and subscapularis muscles. The subscapularis muscle was weighed to determine the degree of mass loss. An additional group of 10 newborn rats was evaluated to determine the sectional muscle fiber size and muscle area of fibrosis by use of images from type I collagen immunostaining. RESULTS There was a significant decrease in passive shoulder external rotation, with a mean loss of 66°; in the thickness of the denervated infraspinatus, with a mean loss of 40%; and in the thickness and weight of the non-denervated subscapularis, with mean losses of 28% and 25%, respectively. No differences were found in subscapularis muscle fiber size and area of fibrosis between shoulders after suprascapular nerve injury. CONCLUSIONS Our study supports the theory that shoulder muscle imbalance is a cause of shoulder contracture in patients with neonatal brachial plexus palsy.

COMPOSITE VASCULARIZED FIBULAR EPIPHYSEO-OSTEO-PERIOSTEAL TRANSFER FOR HIP RECONSTRUCTION AFTER PROXIMAL FEMORAL TUMORAL RESECTION IN A 4-YEAR-OLD CHILD

Literature on the reconstruction of the proximal femur in skeletally immature patients with the use of an epiphyseal transplant is scarce and with variable results depending on the indication. We report successful outcomes using a modified vascularized fibular epiphyseal transplant in a 4‐year‐old boy with an oncologic lesion. We discuss the advantages of supplementing the standard graft with a vascularized fibular periosteal tissue.

Femoral head bone viability after free vascularized fibular grafting for osteonecrosis: SPECT/CT study

To evaluate femoral head bone viability following free vascularized fibular grafting (FVFG) for osteonecrosis using SPECT/CT imaging.

Treatment of congenital pseudarthrosis of the tibia with vascularized fibular periosteal transplant

The vascularized fibular periosteal flap has been recently described and showed solid angio and osteogenic features. We report the use of a free vascularized fibular periosteal transplant in the treatment of a El‐Rosasy‐Paley Type III congenital pseudarthrosis of the tibia in a 7‐year‐old boy, with a prior unsuccessful surgery at the age of three. The contralateral fibular periosteum was used to replace two‐thirds of the hamartomatous tibial periosteum. We did not proceed to debriding the focus of the pseudarthrosis nor addressed the tibial recurvatum or revised the previous tibial rod. Consolidation was achieved radiologically at 3 months, allowing for the tibial rod to be removed. One year postoperatively, the patient ambulated without the use of a protective orthesis and resumed his sports practice. This novel pathogenesis‐based technique showed promising results and a prompt healing of such a difficult orthopedic condition.

Vascularized periosteal graft from the first metatarsal bone: a new technique to prevent collapse of osteonecrosis of the talus in children. A case report.

Several microsurgical techniques have been described for the treatment of osteonecrosis of the talus (ONT). Recently reported in children, vascularized periosteal grafts showed promising revascularizing properties. We report a novel technique using a pedicled periosteal graft from the first metatarsal bone to treat steroid‐induced early Ficat‐Arlet stage III ONT in an 11‐year‐old boy. The patient presented initial favorable clinical and radiological results which were maintained at 34 months during the last follow‐up. Through this original technique, and basing on the powerful osteogenic and vasculogenic propreties of periosteal flaps, we could effectively induce bone revascularization and prevent further collapse of the talar dome.