Our previous rat study demonstrated an ex vivo-created “Biomimetic Hematoma” (BH) that mimics the intrinsic structural properties of normal fracture hematoma, consistently and efficiently enhanced the healing of large bone defects at extremely low doses of rhBMP-2 (0.33 μg). The aim of this study was to determine if an extremely low dose of rhBMP-2 delivered within BH can efficiently heal large bone defects in goats. Goat 2.5 cm tibial defects were stabilized with circular fixators, and divided into groups (n=2-3): 2.1 mg rhBMP-2 delivered on an absorbable collagen sponge (ACS); 52.5 μg rhBMP-2 delivered within BH; and an empty group. BH was created using autologous blood with a mixture of calcium and thrombin at specific concentrations. Healing was monitored with X-rays. After 8 weeks, femurs were assessed using microCT. Using 2.1 mg on ACS was sufficient to heal 2.5 cm bone defects. Empty defects resulted in a nonunion after 8 weeks. Radiographic evaluation showed earlier and more robust callus formation with 97.5 % (52.5 μg) less of rhBMP-2 delivered within the BH, and all tibias were fully bridged at 3 weeks. The bone mineral density was significantly higher in defects treated with BH than with ACS. Defects in the BH group had smaller amounts of intramedullary and cortical trabeculation compared to the ACS group, indicating advanced remodeling. The results confirm that the delivery of rhBMP-2 within the BH was much more efficient than on an ACS. Not only did the large bone defects heal consistently with a 40x lower dose of rhBMP-2, but the quality of the defect regeneration was also superior in the BH group. These findings should significantly influence how rhBMP-2 is delivered clinically to maximize the regenerative capacity of bone healing while minimizing the dose required, thereby reducing the risk of adverse effects

Open limb fractures are typically due to a high energy trauma. Several recent studied have showed treatment's superiority when a multidisciplinary approach is applied. World Health Organization reports that isolate limb traumas have an incidence rate of 11.5/100.000, causing high costs in terms of hospitalization and patient disability. A lack of experience in soft tissue management in orthopaedics and traumatology seems to be the determining factor in the clinical worsening of complex cases. The therapeutic possibilities offered by microsurgery currently permit simultaneous reconstruction of multiple tissues including vessels and nerves, reducing the rate of amputations, recovery time and preventing postoperative complications. Several scoring systems to assess complex limb traumas exist, among them: NISSSA, MESS, AO and Gustilo Anderson. In 2010, a further scoring system was introduced to focus open fractures of all locations: OTA-OFC. Rather than using a single composite score, the OTA-OFC comprises five components grades (skin, arterial, muscle, bone loss and contamination), each rated from mild to severe. The International Consensus Meeting of 2018 on musculoskeletal infections in orthopaedic surgery identified the OTA-OFC score as an efficient catalogue system with interobserver agreement that is comparable or superior to the Gustilo-Anderson classification. OTA-OFC predicts outcomes such as the need for adjuvant treatments or the likelihood of early amputation. An orthoplastic approach reconstruction must pay adequate attention to bone and soft tissue infections management. Concerning bone management: there is little to no difference in terms of infection rates for Gustilo-Anderson types I–II treated by reamed intramedullary nail, circular external fixator, or unreamed intramedullary nail. In Gustilo-Anderson IIIA-B fractures, circular external fixation appears to provide the lowest infection rates when compared to all other fixation methods. Different technique can be used for the reconstruction of bone and soft tissue defects based on each clinical scenario. Open fracture management with fasciocutaneous or muscle flaps shows comparable outcomes in terms of bone healing, soft tissue coverage, acute infection and chronic osteomyelitis prevention. The type of flap should be tailored based on the type of the defect, bone or soft tissue, location, extension and depth of the defect, size of the osseous gap, fracture type, and orthopaedic implantation. Local flaps should be considered in low energy trauma, when skin and soft tissue is not traumatized. In high energy fractures with bone exposure, muscle flaps may offer a more reliable reconstruction with fewer flap failures and lower reoperation rates. On exposed fractures several studies report precise timing for a proper reconstruction. Hence, timing of soft tissue coverage is a critical for length of in-hospital stay and most of the early postoperative complications and outcomes. Early coverage has been associated with higher union rates and lower complications and infection rates compared to those reconstructed after 5-7 days. Furthermore, early reconstruction improves flap survival and reduces surgical complexity, as microsurgical free flap procedures become more challenging with a delay due to an increased pro-thrombotic environment, tissue edema and the increasingly friable vessels. Only those patients presenting to facilities with an actual dedicated orthoplastic trauma service are likely to receive definitive treatment of a severe open fracture with tissue loss within the established parameters of good practice. We conclude that the surgeon's experience appears to be the decisive element in the orthoplastic approach, although reconstructive algorithms may assist in decisional and planification of surgery

Objectives

The purpose of this study was to compare the results and complications of tibial lengthening over an intramedullary nail with treatment using the traditional Ilizarov method.

Anatomical atlases document safe corridors for placement of wires when using fine-wire circular external fixation. The furthest posterolateral corridor described in the distal tibia is through the fibula. This limits the crossing angle and stability of the frame. In this paper we describe a new, safe Retro-Fibular Wire corridor, which provides greater crossing angles and increased stability. In a cadaver study, 20 formalin-treated legs were divided into two groups. Wires were inserted into the distal quarter of the tibia using two possible corridors and standard techniques of dissection identified the distance of the wires from neurovascular structures.

In both groups the posterior tibial neurovascular bundle was avoided. In group A the peroneal artery was at risk. In group B this injury was avoided. Comparison of the groups showed a significant difference (p < 0.001).

We recommend the Retro-Fibular wire technique whereby wires are inserted into the tibia mid-way between the posteromedial border of the fibula and the tendo Achillis, at 30° to 45° to the sagittal plane, and introduced from a posterolateral to an anteromedial position. Subsequently, when using this technique in 30 patients, we have had no neurovascular complications or problems relating to tethering of the peroneal tendons.

Biomechanical studies involving all-wire and hybrid types of circular frame have shown that oblique tibial fractures remain unstable when they are loaded. We have assessed a range of techniques for enhancing the fixation of these fractures. Eight models were constructed using Sawbones tibiae and standard Sheffield ring fixators, to which six additional fixation techniques were applied sequentially.

The major component of displacement was shear along the obliquity of the fracture. This was the most sensitive to any change in the method of fixation. All additional fixation systems were found to reduce shear movement significantly, the most effective being push-pull wires and arched wires with a three-hole bend. Less effective systems included an additional half pin and arched wires with a shallower arc. Angled pins were more effective at reducing shear than transverse pins.

The choice of additional fixation should be made after consideration of both the amount of stability required and the practicalities of applying the method to a particular fracture.