Roberto Vélez

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.

EFFECT OF ADMINISTRATION OF PLATELET-RICH PLASMA IN EARLY PHASES OF DISTRACTION OSTEOGENESIS: AN EXPERIMENTAL STUDY IN AN OVINE FEMUR MODEL

BACKGROUND It has been suggested that platelet-rich plasma (PRP) might enhance bone formation. The aim of this study was to quantify the effect of PRP administered in the early phases of distraction osteogenesis in an ovine femur model. METHODS Twenty sheep aged 4 months underwent osteotomy of the femoral diaphysis followed by distraction osteogenesis. The sheep were divided into two groups of 10. One group received three injections of PRP on days 0, 10, and 20 of the procedure (PRP group) and the other received no additional treatment (control group). The results were evaluated by computed tomography (CT) and histology on completion of distraction osteogenesis (day 40). CT evaluation included measurement of the callus and bone density. Femur size was also measured proximally and distally. Histological evaluation was used to quantify osteoblasts, osteoclasts, vascular lumens, and trabecular maturity by zones and to calculate trabecular bone, fibrous tissue, and cartilage ratios. RESULTS Radiological and histological evaluation of the regenerate bone showed no significant differences between the PRP group and the control group for any of the variables analysed. The only significant difference detected was a wider femur (increased diaphyseal thickness) at the proximal and distal levels in the PRP group. CONCLUSION We found no radiological or histological evidence that the administration of PRP in the early phases of distraction osteogenesis enhances bone formation.

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.

Cyclooxygenase‐2 inhibitor suppresses tumour progression of prostate cancer bone metastases in nude mice

To assess whether celecoxib, a selective cyclooxygenase‐2 (COX‐2) inhibitor with anti‐cancer properties, has an inhibitory effect on tumour establishment and progression of prostate cancer (PCa) bone metastases.

Multidisciplinary Management of a Giant Plexiform Neurofibroma by Double Sequential Preoperative Embolization and Surgical Resection

Plexiform neurofibromas are benign tumors originating from subcutaneous or visceral peripheral nerves, which are usually associated with neurofibromatosis type 1. Giant neurofibromas are very difficult to manage surgically as they are extensively infiltrative and highly vascularized. These types of lesions require complex preoperative and postoperative management strategies. This case report describes a 22-year-old female with a giant plexiform neurofibroma of the lower back and buttock who underwent pre-operative embolization and intraoperative use of a linear cutting stapler system to assist with haemostasis during the surgical resection. Minimal blood transfusion was required and the patient made a good recovery. This case describes how a multidisciplinary management of these large and challenging lesions is technically feasible and appears to be beneficial in reducing perioperative blood loss and morbidity. Giant neurofibroma is a poorly defined term used to describe a neurofibroma that has grown to a significant but undefined size. Through a literature review, we propose that the term “giant neurofibroma” be used for referring to those neurofibromas weighing 20% or more of the patients total corporal weight.

Fetal surgery of extremity amniotic bands: an experimental model of in utero limb salvage in fetal lamb.

Background: Extremity amniotic band (EAB) syndrome can cause an intrauterine amputation as a result of a mechanical effect with progressive strangulation. The aim of the study is to assess the use of fetal surgery of EABs with risk of amputation in the ovine fetus. Methods: Right limbs of fifteen 60-day-gestational age fetal sheep were ligated with silk suture at the infracondylar level. Left limbs were used for paired comparison. Fetuses were randomized into 3 groups: an early-repair group (n = 5), a late-repair group (n = 5), and a nonrepaired group (n = 5). The limbs of the 2 repaired groups underwent fetal release. The limbs obtained from at-term fetuses were analyzed morphologically, functionally, and radiologically. Statistical analysis with paired test was used to compare data. Results: Nonrepaired limbs showed amputation or quasi amputation; the repaired ones did not. However, those late-repaired had significantly reduced passive ankle range of motion, shorter limb length, and mild residual changes. Conclusions: Intrauterine release of potentially severe EABs prevents limb amputation and leads to morphofunctional recovery. Early release shows better results. Clinical Relevance: Intrauterine amputations caused by EABs in the human fetus might be avoidable by fetal surgery. Level of Evidence: Level of evidence II.

A reproducible method for the isolation and expansion of ovine mesenchymal stromal cells from bone marrow for use in regenerative medicine preclinical studies

The use of multipotent mesenchymal stromal cells (MSCs) as candidate medicines for treating a variety of pathologies is based on their qualities as either progenitors for the regeneration of damaged tissue or producers of a number of molecules with pharmacological properties. Preclinical product development programmes include the use of well characterized cell populations for proof of efficacy and safety studies before testing in humans. In the field of orthopaedics, an increasing number of translational studies use sheep as an in vivo test system because of the similarities with humans in size and musculoskeletal architecture. However, robust and reproducible methods for the isolation, expansion, manipulation and characterization of ovine MSCs have not yet been standardised. The present study describes a method for isolation and expansion of fibroblastic‐like, adherent ovine MSCs that express CD44, CD90, CD140a, CD105 and CD166, and display trilineage differentiation potential. The 3‐week bioprocess proposed here typically yielded cell densities of 1.4 × 104 MSCs/cm2 at passage 2, with an expansion factor of 37.8 and approximately eight cumulative population doublings. The osteogenic potential of MSCs derived following this methodology was further evaluated in vivo in a translational model of osteonecrosis of the femoral head, in which the persistence of grafted cells in the host tissue and their lineage commitment into osteoblasts and osteocytes was demonstrated by tracking enhanced green fluorescent protein‐labelled cells. Copyright

How 3D patient-specific instruments improve accuracy of pelvic bone tumour resection in a cadaveric study

Objectives To assess the accuracy of patient-specific instruments (PSIs) versus standard manual technique and the precision of computer-assisted planning and PSI-guided osteotomies in pelvic tumour resection. Methods CT scans were obtained from five female cadaveric pelvises. Five osteotomies were designed using Mimics software: sacroiliac, biplanar supra-acetabular, two parallel iliopubic and ischial. For cases of the left hemipelvis, PSIs were designed to guide standard oscillating saw osteotomies and later manufactured using 3D printing. Osteotomies were performed using the standard manual technique in cases of the right hemipelvis. Post-resection CT scans were quantitatively analysed. Student’s t-test and Mann–Whitney U test were used. Results Compared with the manual technique, PSI-guided osteotomies improved accuracy by a mean 9.6 mm (p < 0.008) in the sacroiliac osteotomies, 6.2 mm (p < 0.008) and 5.8 mm (p < 0.032) in the biplanar supra-acetabular, 3 mm (p < 0.016) in the ischial and 2.2 mm (p < 0.032) and 2.6 mm (p < 0.008) in the parallel iliopubic osteotomies, with a mean linear deviation of 4.9 mm (p < 0.001) for all osteotomies. Of the manual osteotomies, 53% (n = 16) had a linear deviation > 5 mm and 27% (n = 8) were > 10 mm. In the PSI cases, deviations were 10% (n = 3) and 0 % (n = 0), respectively. For angular deviation from pre-operative plans, we observed a mean improvement of 7.06° (p < 0.001) in pitch and 2.94° (p < 0.001) in roll, comparing PSI and the standard manual technique. Conclusion In an experimental study, computer-assisted planning and PSIs improved accuracy in pelvic tumour resections, bringing osteotomy results closer to the parameters set in pre-operative planning, as compared with standard manual techniques. Cite this article: A. Sallent, M. Vicente, M. M. Reverté, A. Lopez, A. Rodríguez-Baeza, M. Pérez-Domínguez, R. Velez. How 3D patient-specific instruments improve accuracy of pelvic bone tumour resection in a cadaveric study. Bone Joint Res 2017;6:577–583. DOI: 10.1302/2046-3758.610.BJR-2017-0094.R1.

Bernese Periacetabular Osteotomy in a Hip Extra-Articular Resection Followed by Reconstruction Using an Extracorporeal Irradiated Acetabulum Autograft with Megaprosthesis, for Proximal Femur Osteosarcoma in a Pediatric Patient

Osteosarcoma is the most common primary malignant tumour of bone. The oncologic surgery of a proximal femur osteosarcoma affecting the hip joint can be very challenging. We present an 8-year-old boy with a 5-month history of right hip pain. Radiographs and magnetic resonance imaging (MRI) showed a lytic lesion of the proximal femur extending 13 cm to the diaphysis. Histological evaluation was consistent with high-grade osteoblastic osteosarcoma. After completing chemotherapy we performed an extra-articular resection of the hip. Reconstruction was accomplished by reimplanting the acetabulum after irradiation and modular proximal femur megaprosthesis. Endoprosthetic reconstruction following proximal femur resection is a good treatment alternative achieving good postoperative function. Extra-articular resection of the hip using a periacetabular osteotomy technique enabled us to achieve wide margins and leave an intact posterior column to optimize acetabular reconstruction stability. Extracorporeal irradiation and reimplantation is a valuable treatment option in a situation such as this where allograft geometric fit is a priority. We conclude that an extra-articular resection of the hip, followed by reconstruction with an extracorporeally irradiated acetabulum and a proximal femur modular megaprosthesis, is a useful combined treatment option for malignant lesions involving the hip joint, especially in paediatric patients.

Vascularized ulnar periosteal pedicled flap for forearm reconstruction: Anatomical study and a case report

Through an anatomical review, the aim of this study is to define the ulnar periosteal branches of the posterior interosseous vessels (PIV). In addition, we report the clinical utility of a vascularized ulnar periosteal pedicled flap (VUPPF), supplied by the investigated PIV, in a complex case of radial nonunion.