Vascularized fibula graft for the traumatically induced long-bone defect

A Novel Method to Assess Healing of Segmental Bone Defects using the Induced Membrane Technique

OBJECTIVE

Clinical concerns exist regarding the quality of bony consolidation in the context of the induced membrane technique. This study evaluates the clinical process of bone grafting in the second stage of induced membrane bone union in patients with tibial bone defects to infer the possibility of non-union and establish a reliable and effective evaluation method combined with computed tomography (CT) to assess fracture healing.

METHODS

Patients with tibial bone defects who underwent the induced membrane technique at our hospital between February 2017 and February 2020 were retrospectively analyzed. The Hounsfield unit (HU) values of the patients were evaluated at different times during the second stage of bone grafting. Bone healing at the boundary value of the 120 HU output threshold (-1024 HU-3071 HU) was directionally selected, and the changes in the growth volume of union (new bone volume [selected according to HU value]/bone defect volume) were compared with analyzing individual class bone union. Method 1 involved X-rays revealing that at least three of the four cortices were continuous and at least 2 mm thick, with the patient being pain free. For Method 2, new bone volume (selected according to HU value/bone defect volume) at the stage was compared with analyzing individual class healing. Receiver operating characteristic curve analysis was used for Methods 1 and 2.

RESULTS

A total of 42 patients with a segmental bone defect with a mean age of 40.5 years (40.5 ± 8.3 years) were included. The relationship between bone graft volume and time variation was analyzed by single factor repeated variable analysis (F = 6.477, p = 0.016). Further, curve regression analysis showed that the change in bone graft volume over time presented a logarithmic curve pattern (Y = 0.563 + 0.086 × ln(X), Ra2 = 0.608, p = 0.041). ROC curve analysis showed that Method 2 is superior to Method 1 (AUC: 86.3% vs. 68.3%, p < 0.05).

CONCLUSION

The induced membrane technique could be used to treat traumatic long bone defects, with fewer complications and a higher healing rate. The proposed imaging grading of HU (new bone volume/bone defect volume) can be used as a reference for the quality of bony consolidation with the induced membrane technique.

Bone reconstruction with modified Masquelet technique in open distal femoral fractures: a case series

BACKGROUND

Large bone defects require complex treatment, multidisciplinary resources, and expert input, with surgical procedures ranging from reconstruction and salvage to amputation. The aim of this study was to provide the results of a case series of open comminuted intra-articular distal femoral fractures with significant bone loss that were managed by early fixation using anatomical plates and a modified Masquelet technique with the addition of surgical propylene mesh.

METHODS

This retrospective study included all patients referred to our institution with OTA/AO C3 distal femur open fractures and meta-diaphyseal large bone loss between April 2019 and February 2021. We treated the fractures with irrigation and debridement, acute primary screw and plate fixation in the second look operation, and Masquelet method using shell-shaped antibiotic beads supplemented by propylene surgical mesh to keep the cements in place. The second step of the procedure was conducted six to eight weeks later with bone grafting and mesh augmentation to contain bone grafts. Surprisingly, hard callus formation was observed in all patients at the time of the second stage of Masquelet procedure.

RESULTS

All five patients' articular and meta-diaphyseal fractures with bone loss healed without major complications. The average union time was 159 days. The mean knee range of motion was 5-95 degrees. The average Lower Extremity Functional Score (LEFS) was 49 out of 80.

CONCLUSIONS

Combination of early plate fixation and the modified Masquelet technique with polypropylene mesh is an effective method for managing large bone defects in open intra-articular distal femoral fractures with bone loss, resulting in shorter union time possibly associated with the callus formation process. This technique may also be applicable to the management of other similar fractures specially in low-income and developing areas.

From replantation to transplantation: The evolution of orthoplastic extremity reconstruction

For more than six decades, the use of the operating microscope for extremity surgery has led to remarkable advances in the management of orthopedic trauma, tumors, infections, and congenital differences. The microsurgical reconstructive ladder ascends from basic microsurgical procedures such as a digital artery or nerve repair to more complex procedures such as autologous tissue transplantation. Functional muscle transfers, toe-to-hand transfers, and recently vascularized composite allotransplantation are the highest rungs on this ladder that help restore extremity function. The development of the orthoplastic approach over the last three decades simultaneously integrates the principles and practices of both orthopedic surgery and plastic surgery for optimal care and salvage of extremities. Clinical, anatomic, and basic science research in reconstructive microsurgery has resulted in significant improvements in extremity salvage, reconstruction, and restoration.

Effects of Combination of BMP7, PFG, and Autograft on Healing of the Experimental Critical Radial Bone Defect by Induced Membrane (Masquelet) Technique in Rabbit

Background

Healing of large segmental bone defects can be challenging for orthopedic surgeons. This research was conducted to provide further insight into the effects of BMP7 in combination with autograft and platelet fibrin glue (PFG) on bone regeneration by Masquelet technique (MT).

Methods

Twenty five domestic male rabbits, more than 6 months old, weighing 2.00±0.25 kg were randomly divided into five equal groups as follows: MT-blank cavity (without any biological or synthetic materials) (1), blank cavity (2), MT-autograft (3), MT-autograft-BMP7 (4), and MT-BMP7-PFG (5). A 20 mm segmental defect was made in radial bone in both forelimbs. The Masquelet technique was done in all groups except group 2. The study was evaluated by radiology, biomechanics, histopathology and scanning electron microscopy.

Results

The results showed that Masquelet technique enhanced the healing process, as, the structural and functional criteria of the injured bone showed significantly improved bone healing (P<0.05). Treatment by PFG-BMP7, Autograft-BMP7, and autograft demonstrated beneficial effects on bone healing. However, Autograft-BMP7 was more effective than autograft in healing of the radial defect in rabbits.

Conclusion

Our findings introduce the osteogenic materials in combination with Masquelet technique as an alternative for reconstruction of the big diaphyseal defects in the long bones in animal models. Our findings may be useful for clinical application in future.

Interposition Arthroplasty of the Elbow After Proximal Ulna Reconstruction With the Masquelet Technique: A Case Report

INTRODUCTION

Periarticular bone loss in the upper extremity poses challenges for a functional reconstruction.

CASE

A 32-year-old man sustained an open elbow fracture-dislocation from a high-velocity gunshot resulting in significant bone and soft-tissue loss about the proximal ulna. He underwent bony reconstruction with the Masquelet technique and delayed interposition arthroplasty in an attempt to preserve function.

CONCLUSIONS

The Masquelet technique, coupled with interposition arthroplasty, may be used to address significant articular bony defects about the proximal ulna, allowing patients to maintain function and limit pain.

Management of Bone Failure in Fracture of the Distal Region of the Femur Using the Masquelet Technique with Fibula Graft Associated with Iliac-Crest Graft: Report of Two Cases

Two cases of bone failure after fracture of the distal region of the femur treated with the Masquelet technique are presented. The first case involves acute bone loss, and the second, pseudarthrosis. The proper management of these lesions led to consolidation and a good functional result.

Bone Grafts, Bone Substitutes, and Orthobiologics: Applications in Plastic Surgery

As reconstructive needs often extend past the soft tissue alone, a plastic surgeon must also be well versed in the methods of bony reconstruction. Understanding of the basic science of fracture healing and the biochemical mechanisms of the different bone grafts, bone substitutes, and orthobiologics is essential to selecting among the many different options available to the modern plastic surgeon. This review provides a broad overview of these different options and the specific applications for plastic surgeons based on anatomic location.

Harnessing extracellular vesicles to direct endochondral repair of large bone defects

Large bone defects remain a tremendous clinical challenge. There is growing evidence in support of treatment strategies that direct defect repair through an endochondral route, involving a cartilage intermediate. While culture-expanded stem/progenitor cells are being evaluated for this purpose, these cells would compete with endogenous repair cells for limited oxygen and nutrients within ischaemic defects. Alternatively, it may be possible to employ extracellular vesicles (EVs) secreted by culture-expanded cells for overcoming key bottlenecks to endochondral repair, such as defect vascularization, chondrogenesis, and osseous remodelling. While mesenchymal stromal/stem cells are a promising source of therapeutic EVs, other donor cells should also be considered. The efficacy of an EV-based therapeutic will likely depend on the design of companion scaffolds for controlled delivery to specific target cells. Ultimately, the knowledge gained from studies of EVs could one day inform the long-term development of synthetic, engineered nanovesicles. In the meantime, EVs harnessed from in vitro cell culture have near-term promise for use in bone regenerative medicine. This narrative review presents a rationale for using EVs to improve the repair of large bone defects, highlights promising cell sources and likely therapeutic targets for directing repair through an endochondral pathway, and discusses current barriers to clinical translation. Cite this article: E. Ferreira, R. M. Porter. Harnessing extracellular vesicles to direct endochondral repair of large bone defects. Bone Joint Res 2018;7:263-273. DOI: 10.1302/2046-3758.74.BJR-2018-0006.

Massive segmental bone loss due to pantibial osteomyelitis in children reconstructed by medial fibular transport with Ilizarov frame

Objectives

Vascularized or non-vascularized fibula transport is a novel procedure for limb salvage but has been associated with high failure rates and complications. Ipsilateral medial fibular transport (IMFT) using Ilizarov apparatus is a modification of the procedure to prevent complications and increase success rate. This article presents the largest series of limb salvage for massive tibial bone loss in children due to pan-osteomyelitis by IMFT with Ilizarov apparatus.

Methods

A case series of 12 patients with a mean age of 12 (6-18) years is described. At the first stage of surgery, the excision of all dead bone was performed, and Ilizarov without traction apparatus was applied. In second stage, ipsilateral fibula is gradually transferred to tibial defect with the help of ilizarov olive wires. In the third stage, the freshening of docking sites of fibula to tibia was performed. The minimum follow up was of two years.

Results

Hypertrophy of the transported fibula accompanied by full weight bearing and satisfactory joint motion occurred in all patients. Removal of sequestrated bone resulted in control of infection in 27.17 ± 7.76 days. Fibular transport took 16.58 ± 4.14 days. The length of tibial bone loss replaced by fibula was 9.50 ± 2.23 cm. The mean days required for union after freshening of the docking site was 76.58 ± 6.20 days.

Conclusions

Ilizarov frame for pan tibial osteomyelitis with bone excision and medial fibular transport works well for limb salvage in children.

Outcomes of cement beads and cement spacers in the treatment of bone defects associated with post-traumatic osteomyelitis

Background

Cement spacers (Masquelet technique) have traditionally been used for the treatment of segmental bone defects. However, no reports have used cement spacers for the treatment of small/partial segmental bone defects associated with osteomyelitis and compared the outcomes with cement beads.

Methods

We retrospectively analysed 40 patients with post-traumatic osteomyelitis of the tibia who underwent treatment, which was performed in two stages. In the first stage, thorough debridement was performed, and bone defects were filled with either antibiotic-impregnated cement beads (bead group, 18 patients) or spacers (spacer group, 22 patients). In the second stage, the cement beads or spacers were removed (for the spacer group, the induced membrane formed by the spacer was preserved) and the bone defects were filled with cancellous autografts.

Results

All patients in the bead group had small/partial segmental bone defects after debridement, while 3 patients in the spacer group had large/segmental bone defects.

The mean volume of bone defects of the spacer group (40.4 cm³) was significantly larger than that of the bead group (32.4 cm³). The infection control rate (88.9%,16/18 vs 90.9%, 20/22), bone healing time (8.5 months vs 7.5 months) and complication rates (22.2%, 4/18 vs 27.2%, 6/22) were comparable between bead group and spacer group.

Conclusion

The results of this study suggest that cement spacers may have an infection control rate comparable to cement beads in the treatment of bone defects associated with post-traumatic osteomyelitis. Furthermore, cement spacers could be used for the reconstruction of small/partial segmental bone defects as well as for large/segmental bone defects, whereas cement beads were not suitable for the reconstruction of large/segmental bone defects.

Free Vascularized Fibular Graft Transfer in the Reconstruction of Defects for Premalignant and Malignant Musculoskeletal Conditions of the Femur in a Tertiary Care Setting in Pakistan: A Series of Six Cases

Objective

To determine the application, success and complications of the utilization of free vascularized fibular grafts (FVFG) in the reconstruction of lower limb defects after resection of primary lower limb musculoskeletal tumors.

Methodology

This descriptive retrospective case series analysis was conducted at Shifa International Hospital from January 2011 to January 2016. It included patients who had premalignant and malignant conditions of the lower limb and subsequently had the lesion resected followed by FVFG surgery. The data collected was to outline the demographic profile, clinical features, and post-procedure outcomes and complications.

Results

There was a total of six patients. The mean age of the patients was 25.8 ± 11.8 years (range: 15-40 years). The patients presented with pain, swelling, inability to bear weight and/or restriction of movement at the joint. Postoperatively, one patient had proximal wound necrosis and one patient had a thrombus in the anastomosed vessels, both of which were managed successfully.

Conclusion

With a success rate of 100% at the end of the six-month follow-up period, FVFG surgery is a reliable procedure that may be successfully carried out for musculoskeletal tumors of the lower limb with minimal complications.

Surgical treatment options for septic non-union of the tibia: two staged operation, Flow-through anastomosis of FVFG, and continuous local intraarterial infusion of heparin

BACKGROUND

The treatment of septic non-union of the tibia is a challenging area.　The objective of this clinical study was to improve the treatment outcomes in patients with a highly active infection by the three strategies consisting of a two-staged operation, a flow-through technique for vascular anastomosis of a free vascularized fibular graft (FVFG), and continuous local intra-arterial infusion of heparin.

PATIENTS & METHOD

Five patients with septic non-union of the tibia who were treated with an FVFG (mean age: 52.8 years) were enrolled.　The mean postoperative follow-up period was 47.2 months, and the mean length of the bone defect was 111 mm.　A two-staged operation, in which polymethylmethacrylate (PMMA) beads containing antibiotics were inserted into a bone defect followed by bone reconstruction performed with an FVFG later.　Vascular anastomosis was performed with the flow-through technique in all patients.　Immediately after FVFG, heparin was continuously infused through a femoral arterial catheter for 1 week.

RESULT

Bone union was confirmed an average of 18.8 weeks after-surgery in all patients without reoperation for thrombus.

CONCLUSION

Our attempt to apply the strategies appears to be a viable treatment option for septic non-union of the tibia.

Is the Induced-membrane Technique Successful for Limb Reconstruction After Resecting Large Bone Tumors in Children?

BACKGROUND

Resection of primary malignant tumors often creates large bony defects. In children, this creates reconstructive challenges, and many options have been described for limb salvage in this setting. Studies have supported the use of an induced-membrane technique after placement of a cement spacer to aid in restoration of bone anatomy.

QUESTIONS/PURPOSES

We asked: (1) What complications are associated with the induced-membrane technique? (2) How often is bone healing achieved after resection greater than 15 cm using this technique? (3) What is the functional outcome of patients treated with this technique?

METHODS

We performed a retrospective evaluation of eight patients with a mean age of 13.3 years (range, 11-17 years) treated for a malignant bone tumor between 2002 and 2012 at our centers. The primary malignant tumors involved the proximal humerus, femur, and tibia. All patients were treated using the induced-membrane technique after a resection with mean bone loss of 18 cm (range, 16-23 cm). The general indication for using the induced-membrane technique during this time was a large diaphyseal defect after resection of the tumor. In addition to using cancellous graft as with the original technique, in the current patients an autogenous nonvascularized fibula was used to enhance stability. The patients were assessed at the last followup using the Musculoskeletal Tumor Society (MSTS) scoring system. Mean followup was 47.1 months (range, 24-120 months), and none of the patients were lost to followup before 2 years.

RESULTS

A total of four unplanned reoperations were performed in these eight patients. A fracture of the reconstruction occurred in three patients and all were treated successfully, two with surgery and one with immobilization. Bone fusion was obtained in all patients within 4 to 8 months (mean, 5.6 months) after the reconstruction. The mean healing index was 0.31 month/cm of reconstruction (range, 0.23-0.5 month/cm). At last followup, the mean MSTS score was 74% (range, 67%-80%).

CONCLUSIONS

Our findings suggest that the modified induced-membrane technique is a reasonable alternative to other limb reconstruction techniques for bone tumors in children and has the advantage of not requiring a bone bank or an expensive metal prosthesis. Although more patients will be needed to substantiate our findings, it has become a standard part of our arsenal in the treatment of large bone defects after resection of pediatric primitive bone tumors.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Management of segmental skeletal defects by the induced membrane technique

BACKGROUND

Surgical reconstruction of segmental skeletal defects represents a true challenge for the orthopedic surgeons. Recently, Masquelet et al. described a two-stage technique for reconstruction of bone defects, known as the induced membrane technique. The aim of this study is to assess the results of the induced membrane technique in the management of segmental skeletal defects resulting from debridement of bone infection.

MATERIALS AND METHODS

Seventeen patients with segmental skeletal defects were treated in our institution by the induced membrane technique. The average age of the patients was 43 years (range 26- 58 years). The causes of the defects were infected gap nonunion in 12 cases and debridement of osteomyelitis in 5 cases. The defects were located in the tibia (n = 13) and the femur (n = 4). The mean defect was 7 cm (range 4 cm - 11 cm). All cases were treated by the induced membrane technique in two-stages.

RESULTS

Bone union happened in 14 patients. The limb length discrepancy did not exceed 2.5 cm in the healed cases. The mean time of healing was 10 months (range 6-19 months). The complications included nonunion of the graft in five cases, failure of graft maturation in two cases, reactivation of infection in two cases and refracture after removal of the frame in one case. These complications were managed during the course of treatment and they did not affect the final outcome in all patients except three.

CONCLUSION

The induced membrane technique is a valid option for the management of segmental skeletal defects. It is a simple and straight forward procedure, but the time required for growth and maturation of the graft is relatively long.

Masquelet technique for the treatment of a severe acute tibial bone loss

The "induced membrane" technique described by Masquelet has been used successfully for many years for posttraumatic bone defect reconstruction, non-unions and osteomyelitis. The main advantages are the two-step surgical procedure that in case of primary infection allows repeated debridement if necessary, in case of internal fixation early weight bearing with decreased malalignment risk and it has a short learning curve. A theoretical application of this procedure is the management of acute severe traumatic bone loss of the limbs despite the lack of this experience in literature. We report on a Gustilo IIIB meta-epiphyseal fracture (AO 43-C3) of the leg with a 6 cm in length bone loss that was treated with the Masquelet technique.

Assessment of vascularized free fibula transplantation revealing a congenital aplastic posterior tibial artery: a case report

Introduction

Anatomical abnormalities in the lower limb vessels are uncommon. However, the preoperative evaluation of the anatomical variations is very important for planning the operation procedure to prevent jeopardizing the donor leg.

Case presentation

In this case report, a 23-year-old Asian woman who was scheduled to have vascularized free fibula transplantation for reconstruction of her wrist after excision of bone tumor in her distal radius, was found to have congenital aplastic posterior tibial arteries in both legs. These findings were found on magnetic resonance angiography (our preferred methodology due to its simplicity). We planned testing the sufficiency of her pedal pulses after temporarily clamping her peroneal artery but prior to harvesting, to ensure minimal risk to the longevity of her donor leg. During the operation, after dissection of a 10cm segment of her fibula with the peroneal artery, the peroneal artery proximal to the graft was temporarily clamped and the tourniquet was released. As adequate sustainable pedal pulses were confirmed, the graft was harvested and transplanted to her wrist. There was no morbidity in her right leg postoperatively and the union of the grafted fibula was substantiated 10 months postoperatively.

Conclusions

We concluded two findings: firstly, for accurate preoperative planning of a vascularized free fibula procedure, examination of the bilateral lower leg vasculature either by angiography or other imaging should be performed. Secondly, abnormalities are not in themselves reason to abandon the vascularized free fibula procedure. We contend that pedal pulses should be evaluated preoperatively and provided that adequate foot circulation can be confirmed (by temporarily clamping the vessels and releasing the tourniquet during the operation prior to harvesting the free vascularized fibula) the procedure should be successful without jeopardizing the donor leg.

Bone transport with an external fixator and a locking plate for segmental tibial defects

Although gradual bone transport may permit the restoration of large-diameter bones, complications are common owing to the long duration of external fixation. In order to reduce such complications, a new technique of bone transport involving the use of an external fixator and a locking plate was devised for segmental tibial bone defects. A total of ten patients (nine men, one woman) with a mean age at operation of 40.4 years (16 to 64) underwent distraction osteogenesis with a locking plate to treat previously infected post-traumatic segmental tibial defects. The locking plate was fixed percutaneously to bridge proximal and distal segments, and was followed by external fixation. After docking, percutaneous screws were fixed at the transported segment through plate holes. At the same time, bone grafting was performed at the docking site with the external fixator removed. The mean defect size was 5.9 cm (3.8 to 9.3) and mean external fixation index was 13.4 days/cm (11.8 to 19.5). In all cases, primary union of the docking site and distraction callus was achieved, with an excellent bony result. There was no recurrence of deep infection or osteomyelitis, and with the exception of one patient with a pre-existing peroneal nerve injury, all achieved an excellent or good functional result. With short external fixation times and low complication rates, bone transport with a locking plate could be recommended for patients with segmental tibial defects.

The reconstructive microsurgery ladder in orthopaedics

Since the advent of the operating microscope by Julius Jacobson in 1960, reconstructive microsurgery has become an integral part of extremity reconstruction and orthopaedics. During World War I, with the influx of severe extremity trauma Harold Gillies introduced the concept of the reconstructive ladder for wound closure. The concept of the reconstructive ladder goes from simple to complex means of attaining wound closure. Over the last half century microsurgery has continued to evolve and progress. We now have a microsurgical reconstructive ladder. The microsurgical reconstruction ladder is based upon the early work on revascularization and replantation extending through the procedures that are described in this article.

Improved healing of large segmental defects in the rat femur by reverse dynamization in the presence of bone morphogenetic protein-2

BACKGROUND

Large segmental defects in bone do not heal well and present clinical challenges. This study investigated modulation of the mechanical environment as a means of improving bone healing in the presence of bone morphogenetic protein (BMP)-2. Although the influence of mechanical forces on the healing of fractures is well established, no previous studies, to our knowledge, have described their influence on the healing of large segmental defects. We hypothesized that bone-healing would be improved by initial, low-stiffness fixation of the defect, followed by high-stiffness fixation during the healing process. We call this reverse dynamization.

METHODS

A rat model of a critical-sized femoral defect was used. External fixators were constructed to provide different degrees of stiffness and, importantly, the ability to change stiffness during the healing process in vivo. Healing of the critical-sized defects was initiated by the implantation of 11 μg of recombinant human BMP (rhBMP)-2 on a collagen sponge. Groups of rats receiving BMP-2 were allowed to heal with low, medium, and high-stiffness fixators, as well as under conditions of reverse dynamization, in which the stiffness was changed from low to high at two weeks. Healing was assessed at eight weeks with use of radiographs, histological analysis, microcomputed tomography, dual x-ray absorptiometry, and mechanical testing.

RESULTS

Under constant stiffness, the low-stiffness fixator produced the best healing after eight weeks. However, reverse dynamization provided considerable improvement, resulting in a marked acceleration of the healing process by all of the criteria of this study. The histological data suggest that this was the result of intramembranous, rather than endochondral, ossification.

CONCLUSIONS

Reverse dynamization accelerated healing in the presence of BMP-2 in the rat femur and is worthy of further investigation as a means of improving the healing of large segmental bone defects.

CLINICAL RELEVANCE

These data provide the basis of a novel, simple, and inexpensive way to improve the healing of critical-sized defects in long bones. Reverse dynamization may also be applicable to other circumstances in which bone-healing is problematic.

Overcoming hypoxia in 3D culture systems for tissue engineering of bone in vitro using an automated, oxygen-triggered feedback loop

Tissue engineering is an attractive approach to heal bony defects. However, three-dimensional cell-scaffold constructs display uneven oxygen supply resulting in inhomogeneous tissue quality. We assessed different strategies to improve oxygen supply in vitro. Scaffolds with differing inner surface were seeded with preosteoblastic cells and cultivated either statically or in perfusion bioreactors. Oxygen concentration and pH were measured in the center of the scaffolds. An inductive feedback mechanism was build to increase bioreactor pump speed according to the oxygen concentrations measured within the scaffolds. While pH remained stable, oxygen concentration decreased significantly under static conditions within the cell-seeded scaffolds. Reducing the scaffolds' inner surface as well as increasing perfusion speeds in bioreactors resulted in improved oxygen supply. We conclude that improving oxygen supply to three dimensional culture systems for bone tissue engineering is feasible in an automated manner. Culture conditions have to be adapted to each cell-scaffold system individually.

The effect of intramedullary reaming on a diaphyseal bone defect of the tibia

BACKGROUND

The effect of intramedullary reaming on diaphyseal tibial defects has not been examined in the literature. The present aim was to relate the extent of reaming to angiogenesis and bone formation occurring around a critical-sized defect in the tibia for two scenarios, namely, when the bone defect is left empty and when the bone defect is treated with autograft.

METHODS

Eleven canines were allocated into two groups, namely, empty (n=5) or iliac crest autograft (n=6). All tibiae were reamed to 7.0 mm and fixed with a 6.5-mm statically locked intramedullary nail after creation of an 8.0-mm diaphyseal defect. The extent of reaming of the canal was dependent on the cross-sectional area of the tibia, because all tibiae were reamed to 7.0 mm. Fluorescent markers were administered at different times: calcein green (6 weeks), xylenol orange (9 weeks), and tetracycline (11 weeks and 14 weeks). Animals were sacrificed at 15 weeks and perfused with a barium compound. Analysis consisted of radiography, micro-computed tomography scan, and histology.

RESULTS

Linear regression analysis of percent bone volume and canal area provided a Pearson correlation coefficient of r=0.925 (p=0.025) for empty samples and r=0.244 (p=0.641) for autograft samples. Linear regression analysis of percent vasculature volume and canal area provided a Pearson correlation coefficient of r=0.784 (p=0.117) for empty samples and r=-0.146 (p=0.783) for autograft samples. Bone formation rates were reported as the distance between the fluorescent labels and were less within the endosteum, cortex, and periosteum, with extensive reaming in empty samples.

CONCLUSIONS

The results suggest that limited reaming may be beneficial to the acute management of tibial shaft fractures with a bone defect.

A biodegradable scaffold for the treatment of a diaphyseal bone defect of the tibia

The aim of this study was to compare angiogenesis and osteogenesis occurring within 8.0 mm diaphyseal defects created in canine tibiae treated using autograft or a biodegradable bone scaffold. All tibiae were reamed to 7.0 mm and fixed with a 6.5-mm statically locked intramedullary nail. Each of the 18 canines as allotted to one of three treatment groups: (1) left empty (N = 5), (2) treated with iliac crest autograft (N = 6), or (3) treated with a PLGA/calcium phosphate biodegradable scaffold (N = 7). Fluorescent markers were given at successive time periods: calcein green at 6 weeks, xylenol orange at 9 weeks, and tetracycline at 11 and 14 weeks. Animals were sacrificed at 15 weeks and their legs were perfused with a radio opaque compound. Samples were analyzed using Micro CT, bright-field microscopy and fluorescent microscopy. Scaffold samples were found to have significantly greater bone formation (p = 0.015) and blood vessel formation (p < 0.001) at their osteotomy sites than autograft samples. Bone formation rate in the periosteum was significantly greater in the autograft samples than the scaffold samples for all time periods. Bone formation at the osteotomy site was found to be significantly greater when associated with greater blood vessel formation (p = 0.026). The PLGA/calcium phosphate biodegradable scaffold we have employed supports angiogenesis within a segmental tibial defect that has adequate soft tissue coverage.

Extremity war injuries: challenges in definitive reconstruction

The third annual Extremity War Injuries Symposium was held in January 2008 to review challenges related to definitive management of severe injuries sustained primarily as a result of blast injuries associated with military operations in the Global War on Terror. Specifically, the symposium focused on the management of soft-tissue defects, segmental bone defects, open tibial shaft fractures, and challenges associated with massive periarticular reconstructions. Advances in several components of soft-tissue injury management, such as improvement in the use of free-tissue transfer and enhanced approaches to tissue-engineering, may improve overall care for extremity injuries. Use of distraction osteogenesis for treatment of large bone defects has been simplified by the development of computer-aided distraction protocols. For closed tibial fractures, evidence and consensus support initial splinting for transport and aeromedical evacuation, followed by elective reamed, locked intramedullary nail fixation. Management of open tibial shaft fractures sustained as a result of high-energy combat injuries should include serial débridements every 48 hours until definitive wound closure and stabilization are recommended. A low threshold is recommended for early utilization of fasciotomies in the overall treatment of tibial shaft fractures associated with war injuries. For management of open tibial fractures secondary to blast or high-velocity gunshot injuries, good experiences have been reported with the use of ring fixation for definitive treatment. Treatment options in any given case of massive periarticular defects must consider the specific anatomic and physiologic challenges presented as well as the capabilities of the treating surgeon.

Composite tissue transfer in upper extremity trauma

Unlike congenital malformations or defects resulting from tumour ablation, trauma of the upper extremity is more complex to manage. Also because of the structural complexity of the upper extremity, tissue defects often result in exposure of vital structures such as bone, nerve, blood vessels and tendons. Thus, a successful reconstruction after upper extremity trauma must be approached with the goals of not only providing stable coverage but most importantly, restoring function. We present the state-of-the-art material on composite tissue transfer in upper extremity trauma. This chapter describes the modern philosophy of emergency wound management, the optimal timing of reconstruction, and the basic principles in selection of coverage tissue, as well as outlining the advantages, disadvantages, and indications of several most commonly used flaps. In our opinion, radical debridement followed by primary reconstruction is always the first choice when treating traumatic injuries. Microsurgical transplantation of composite tissue to the upper extremity results in the best wound coverage and early functional rehabilitation. Simultaneously, multicomponent reconstruction can also be achieved with minimal donor site morbidity and aesthetically acceptable donor sites.

Innovations in osteosynthesis and fracture care

Over the years giant steps have been made in the evolution of fracture fixation and the overall clinical care of patients. Better understanding of the physiological response to injury, bone biology, biomechanics and implants has led to early mobilisation of patients. A significant reduction in complications during the pre-operative and post-operative phases has also been observed, producing better functional results. A number of innovations have contributed to these improved outcomes and this article reports on the advances made in osteosynthesis and fracture care.

Lumbosacral reconstruction for intractable pyogenic spondylitis using a total leg flap with a vascularized tibia graft

✓This report describes an effective technique of using a total leg flap for treating a 57-year-old male paraplegic patient with intractable sacral pyogenic spondylitis caused by methicillin-resistant Staphylococcus aureus. Spondylitis was accompanied by severe instability of the lumbosacral area, a large lumbosacral ulcer, and a large bone and muscle defect, which made it difficult for the patient to maintain a sitting position. A total leg flap procedure, a modification of the total thigh flap procedure, was performed as a 1-stage salvage surgery. The vascularized tibia and fibula were grafted between the lumbar and sacral vertebrae, and a musculocutaneous flap was used to cover the extensive ulceration in the lumbosacral skin defect. The intractable lesion of the lumbosacral spine, which had not been cured for more than 2 years despite repeated debridement, intravenous antibiotic injections, sugar treatment, pyoktanin treatment, and hyperbaric O2 treatment, subsided and stabilized within 1 year of surgery. The patient returned to activities of daily living using a wheelchair, and was very satisfied with the results. Use of a total leg flap with a vascularized tibia graft is an effective treatment for intractable pyogenic spondylitis accompanied by a large bone defect and large lumbosacral ulcers.