Comparison of free fibular flaps with reamer-irrigator-aspirator bone grafts for the reconstruction of critical-sized mandibular defects.

OBJECTIVE: Vascularized bone flaps are currently indicated for reconstructing mandibular defects 6 cm or larger. This technique can result in donor-site morbidity and requires microsurgery. To explore alternative methods of mandibular reconstruction, we sought to compare bone graft obtained with the reamer-irrigator-aspirator (RIA) device with the free fibula (FF) flap for the reconstruction of a critical-sized mandibular defect. METHODS: Sixteen 3-month-old Yorkshire pigs underwent 6-cm full-thickness resection of the left mandible. For the FF group (n = 8), an osseous FF flap was raised from the left leg and placed into the defect. For the RIA group (n = 8), a RIA Instrument Set was used on the ipsilateral femur to ream the femoral canal and harvest RIA putty. This putty containing medullary bone marrow contents and cortical bone was packed into the defect. At the study end point, volumetric, biomechanical, and histologic analyses were performed. RESULTS: Operative times were significantly shorter in the RIA group (RIA,126 [30] min; FF, 346 [50] min; P < 0.05). Biomechanical testing of reconstructed sites showed no significant difference in maximum fracture loads between both groups (RIA, 468 [97] N; FF, 689 [262] N; P = 0.11). Mean (SD) volume ratio of bone growth at the reconstructed sites was comparable between both groups (RIA, 71% [4.5%]; FF, 72% [3.3%]; P = 0.60). Equal bone quality was confirmed histologically. CONCLUSIONS: The RIA technique significantly reduces operative time and provides bone of equal strength and histologic quality to FF flap reconstruction in a large animal model. The RIA method may represent an efficient technique for the reconstruction of craniomaxillofacial defects.

Treatment of severe post-traumatic bone defects with autologous stem cells loaded on allogeneic scaffolds.

Mesenchymal stem cells may differentiate into angiogenic and osteoprogenitor cells. The effectiveness of autologous pluripotent mesenchymal cells for treating bone defects has not been investigated in humans. We present a case series to evaluate the rationale of using nucleated cells from autologous bone marrow aspirates in the treatment of severe bone defects that failed to respond to traditional treatments. Ten adult patients (mean age, 49.6-years-old) with severe bone defects were included in this study. Lower limb bone defects were >or=5 cm3 in size, and upper limb defects .or=2 cm3. Before surgery, patients were tested for antibodies to common pathogens. Treatment consisted of bone allogeneic scaffold enriched with bone marrow nucleated cells harvested from the iliac crest and concentrated using an FDA-approved device. Postsurgery clinical and radiographic follow-up was performed at 1, 3, 6, and 12 months. To assess viability, morphology, and immunophenotype, bone marrow nucleated cells were cultured in vitro, tested for sterility, and assayed for the possible replication of adventitious (contaminating) viruses. In 9 of 10 patients, both clinical and radiographic healing of the bone defect along with bone graft integration were observed (mean time, 5.6 months); one patient failed to respond. No post-operative complications were observed. Bone marrow nucleated cells were enriched 4.49-fold by a single concentration step, and these enriched cells were free of microbial contamination. The immunophenotype of adherent cells was compatible with that of mesenchymal stem cells. We detected the replication of Epstein-Barr virus in 2/10 bone marrow cell cultures tested. Hepatitis B virus, cytomegalovirus, parvovirus B19, and endogenous retrovirus HERV-K replication were not detected. Overall, 470 to 1,150 million nucleated cells were grafted into each patient. This case series, with a mean follow-up of almost 2 years, demonstrates that an allogeneic bone scaffold enriched with concentrated autologous bone marrow cells obtained from the iliac crest provides orthopedic surgeons a novel option for treating important bone defects that are unresponsive to traditional therapies.

The outcome of composite bone graft substitute used to treat cavitary bone defects.

Although autogenous bone graft remains the gold standard graft material, it is associated with an unacceptably high incidence of morbidity. Furthermore, operative time, blood loss, and length of hospitalization are often increased. In order for a graft substitute to replicate the optimal bone healing properties of autogenous graft, 3 essential elements must be present: scaffolding for osteoconduction, growth factors for osteoinduction, and progenitor cells for osteogenesis. A composite graft that combines a synthetic scaffold with osteoprogenitor cells from bone marrow aspirate (BMA) may potentially deliver the advantages of autogenous bone grafts without the procurement morbidity. Sixty consecutive patients with cavitary bone defects were treated with a composite of b-tricalcium phosphate (beta-TCP), Vitoss (Orthovita, Malvern, Pennsylvania), and BMA. The cavitary defects were measured on orthogonal views by experienced musculoskeletal radiologists. Radiographically, resorption and trabeculation increased steadily with time. This differential was slightly more noticeable in large defects with a central trabeculation occurring in advance of the peripheral region. The majority of patients progressed to unrestricted activities by 6 weeks and had returned to their usual activities by 12 weeks. No significant difference in graft incorporation rate was noted based on age, size of defect, or use of adjuvant local treatment. The use of a composite graft (ultraporous beta-TCP+BMA) in the treatment of cavitary lesions appears to be safe and effective.

Evaluation of autologous bone marrow mesenchymal stem cell-calcium phosphate ceramic composite for lumbar fusion in rhesus monkey interbody fusion model.

Autologous bone marrow mesenchymal stem cell (BMSC)-calcium phosphate ceramic composites were constructed in vitro and implanted as a bone graft substitute for lumbar anterior interbody fusion in rhesus monkeys to determine the osteogenic capacity of the composites. Nine adult rhesus monkeys underwent lumbar L3-L4 and L5-L6 diskectomy and interbody fusion via an anterior retroperitoneal approach. Two fusion sites in each animal were randomly assigned to two of three treatments: autogenous tricortical iliac crest bone graft (autograft group), cell-free ceramic graft (ceramic group), or BMSC-ceramic composite graft (BMSC group). Autologous BMSCs were expanded in culture and stimulated with osteogenic supplement. The spinal fusion segments were evaluated by radiography, biomechanical testing, histologic analysis, and histomorphometric analysis 3 months postsurgery. The BMSC group achieved lumbar interbody fusion superior to that of the ceramic group, both biomechanically and histologically. The BMSC group and the autograft group showed equivalent biomechanical stiffness. Ceramic residues were significantly greater in the ceramic group versus the BMSC group. The results indicate that BMSC-ceramic composites can enhance bone regeneration and achieve osseous spinal fusion 3 months after implantation in the rhesus monkey interbody fusion model.

Thrombotic complications of silicone rubber catheters during autologous marrow and peripheral stem cell transplantation: prospective comparison of Hickman and Groshong catheters.

Thrombosis is common after placement of silicone rubber subclavian vein catheters in patients with malignancy receiving conventional doses of chemotherapy. To determine the incidence of this complication in marrow transplant patients and the effect of different catheter designs on thrombosis rates, patients were randomized to receive either open-ended Hickman catheters or valve-ended Groshong catheters for venous access during the transplantation procedure. A total of 35 catheters were placed, of which 23 were double-lumen (11 Groshong and 12 Hickman) and 12 were single-lumen (six Groshong and six Hickman). Arm venograms were performed on all patients at the time of hematopoietic recovery or occurrence of symptoms of subclavian vein thrombosis. There were 10 cases of total subclavian vein thrombosis (three were symptomatic) and 12 cases of asymptomatic non-occlusive mural thrombi. Only 13 normal veins were found. There was no difference in thrombosis rate between the Hickman and Groshong catheters. Double lumen catheters tended to be more likely to cause total venous occlusion (nine of 23) than single lumen catheters (one of 12) (p = 0.06, Fisher's exact test). We conclude that subclavian vein thrombosis is a common occurrence after placement of silicone rubber catheters for venous access during marrow transplantation. Most cases are asymptomatic. Groshong catheters are just as likely to cause this complication as Hickman catheters.

[A novel therapeutic approach to bone replacement: vitalisation of industrial processed allogenic bone graft with autologous bone marrow]. / Das "vitalisierte" Allograft als Alternative im Knochenersatz.

AIM: Osseous defects of the human skeleton are a common problem in reconstructive orthopaedic and trauma surgery. In spite of a long-standing history of research on different organic and inorganic bone replacement materials, a clinically applicable alternative to autogenous bone transplants has not been found. METHODS: The current paper describes a novel bone replacement material, which is vitalised through injection of autologous bone marrow. Industrially processed bone allografts were used for bone replacement; the cancellous bone graft was gained from femoral heads from living human donors and processed by a French tissue bank (Banque de Tissus France, TBF). Sterile packed allogenic bone grafts can be stored at room temperature, are easy to handle and can be adapted to almost every bone defect due to their stability and versatility. RESULTS: From July 2003 to February 2006 125 patients,70 men and 55 women, underwent bone grafting with composite transplants composed of autogenous marrow cells and industrial processed bone allografts. The average age at surgery was 62 (14-84) years; the follow-up period was 11 months. The indication to use the allograft included the whole spectrum of bony defects conventionally treated with autologous cancellous bone grafts such as primary and revision surgery in THA (n = 64) and the treatment of pseudarthrosis particularly of the lower limb (n = 30). CONCLUSION: In comparison to current bone replacement materials applied in clinical use, this approach promises to replicate the biomechanical and biological properties of autogenous cancellous bone. This is an important advantage over conventional approaches to ensure successful healing and regeneration of bone defects. Hence application of vitalised bone allograft represents an important alternative to conventional autogenous cancellous bone which avoids certain complications associated with harvesting and transplantation of autogenous bone. This applies in particular in situations in which harvesting of autogenous cancellous bone is not or no longer possible.

Study of in vivo differentiation of rat bone marrow stromal cells into schwann cell-like cells.

In order to raise an abundant and accessible reservoir for Schwann cells (SCs), which are used as seed cells for constructing tissue-engineered nerve grafts, we investigated the feasibilty of in vivo differentiation of bone marrow stromal cells (MSCs) into SC-like cells. In this study, MSCs were harvested from adult rats' bone marrow, culture-expanded, and characterized. Subcultured MSCs were then labeled with Hoechst 33342, followed by transplantation into the nerve regeneration chamber, which was made of a silicone tube bridging the sciatic nerve defect of the rats. Four weeks after surgery, some of the differentiated MSCs turned into SC-like cells immunopositive to S-100 protein, accompanied by myelination of the regenerated nerve fibers. Walking-track analyses provided evidence that transplantation of MSCs contributed to reconstruction of the sciatic nerve and reinnervation of target tissues. The experimental results suggest that MSCs are capable of differentiating into SC-like cells in vivo, making them a promising candidate for cell transplantation in peripheral nerve repair.

[Tibial bone harvesting technique for filling maxillary bone gaps in implantology]. / Prélèvement osseux tibial pour comblement osseux maxillaire en implantologie.

We present an easy and quick technique of tibial bone grafting that can be used in maxillary bone losses, specially in implantology. The surgical technique is performed under general anaesthesia. A 1.5 cm skin incision is made on the anteromedial side of the tibia. Then the bone marrow can be approached through a cortical window drilled with a motorized trephine. At this stage, a disposable bone aspirator is used to collect the cancellous bone. At the end of the procedure, the periosteum, the subcutaneous tissues and the skin are sutured in three layers. The quantity of harvested cancellous bone varies from 18 to 30 cc. The procedure duration is about twenty minutes. The complication rate is low and the patients are able to walk a few hours after the procedure. They leave the hospital on the day after. Tibial bone harvesting is an alternative technique that can be chosen in cases with large bone defects. This tibial graft can be recommended because of its low morbidity, the quality of the bone and the short time duration of the procedure. Some details must be pointed out. A medial tibial surgical approach is for us better than a lateral approach because of its lower morbidity and because the bone is more superficial. The use of a motorized trephine is important to lift precisely the cortical bone window and because it is less traumatic than the hand trephine. The disposable bone aspirator is an excellent option to pick-up bone marrow with a minimum loss of bone material and in a shorter time.

Reconstruction of mandibular continuity defects in dogs using poly (L-lactide) mesh and autogenic particulate cancellous bone and marrow: preliminary report.

PURPOSE: This study evaluated the reconstruction of continuity defects in the canine mandible using a poly [L-lactide] (PLLA) mesh tray and particulate cancellous bone and marrow (PCBM). MATERIALS AND METHODS: Eight adult dogs were divided into two groups of four dogs each. In group A, each dog had a tray fixed with stainless steel wires on each side of the mandibular stumps with the concave surface of the tray attached to the inferior border of the mandible (U-fixation). In group B, the concave surface was attached to the superior border (inverted U-fixation). Each tray was filled with PCBM from the ilium. After the operation, the dogs were radiographed, and specimens were examined histologically at 3-, 6-, and 12-month intervals. RESULTS: All of group A showed good clinical healing and the continuity of the mandibular bone was regained within 3 months postoperatively. However, fibrous tissue had invaded through the area above the tray, resulting in a poorly shaped alveolar ridges. In group B, the dogs showed good bony regeneration with well-shaped alveolar ridges. However, two animals in this group had partial exposure of the PLLA mesh tray into the oral cavity. CONCLUSION: It is suggested that a combination of the PLLA mesh and PCBM grafts might be a useful technique for functional reconstruction of the jaw bone, specifically using method A (U-fixation) as a technique to reconstruct continuity defects of the mandible, and method B (inverted, U-fixation) as a promising method for alveolar reconstruction to make wearing dentures possible.

Supraclavicular approach to the subclavian/innominate vein for large-bore central venous catheters.

Infraclavicular and internal jugular catheterization are commonly used techniques for hemodialysis access, but may at times be impeded in patients whose anatomy makes cannulation difficult. In an effort to enlarge the spectrum of alternative access sites, we evaluated the supraclavicular approach for large-bore catheters. During an 18-month period we prospectively collected data on success rate and major and minor complications of the supraclavicular access for conventional dialysis catheters as well as Dacron-cuffed tunneled devices in 175 adult patients admitted for various extracorporeal therapies and bone marrow transplantation. Two hundred eight large-bore catheters (99 conventional dialysis catheters, 63 semirigid tunneled Dacron-cuffed catheters, and 46 Hickman catheters) were successfully placed in 164 patients (success rate, 93.8%), 58 (33.1%) of whom had been previously catheterized. Complications included pneumothorax (one patient), arterial puncture (seven patients), and puncture of the thoracic duct (two patients) without sequelae. Postinsertional chest radiographs demonstrated impressive coaxial lie of most catheters. Catheter malpositions occurred only sporadically (1%). Difficulty of introducing the catheter via a placed sheath was rarely observed. There was no clinically significant evidence of catheter-induced venous thrombosis or stenosis. We conclude that the supraclavicular route is an easy and safe first approach for large-bore catheters, as well as a useful alternative to traditional puncture sites for precatheterized and anatomically problematic patients.