Purpose

Angiogenesis and osteogenesis are essential for bone growth, fracture repair, and bone remodeling. VEGF has an important role in bone repair by promoting angiogenesis and osteogenesis. In our previous study, endothelial progenitor cells (EPCs) promoted bone healing in a rat segmental bone defect as confirmed by radiological, histological and microCT evaluations (Atesok, Li, Schemitsch 2010); EPC treatment of fractures resulted in a significantly higher strength by biomechanical examination (Li, Schemitsch 2010). In addition, cell-based VEGF gene transfer has been effective in the treatment of segmental bone defects in a rabbit model (Li, Schemitsch et al 2009); Purpose of this study: Evaluation of VEGF gene expression after EPC local therapy for a rat segmental bone defect.

Purpose: Severe fractures damage blood vessels and disrupt circulation at the fracture site resulting in an increased risk of poor fracture healing. Endothelial progenitor cells (EPCs) are bone-marrow derived cells with the ability to differentiate into endothelial cells and contribute to neovascularization and re-endothelialization after tissue injury and ischemia. We have previously reported that EPC therapy resulted in improved radiographic healing and histological blood vessel formation in a rat fracture model. The purpose of this study was to further quantify the effects of EPC therapy with microCT and biomechanical analyses.

Method: Five-millimeter segmental defects were created and stabilized in the femora of 14 fisher 344 rats. The treatment group (n=7) received 1x106 EPCs within gelfoam locally at the area of the bone defect and control animals (n=7) received only saline-gelfoam with no cells. The formation and healing of bone after 10 weeks were asessed by radiographic, micro-CT and biomechanical analyses.

Results: Radiographically all the animals in EPC-treated group healed with bridging callus formation, whereas control group animals demonstrated radiographic non-union. Micro-CT assessment demonstrated significantly improved parameters of bone volume (35.34 to 20.68 mm³, p=0.000), bone volume density (0.24 to 0.13%, p=0.001), connectivity density (25.13 to 6.15%, p=0.030), trabecular number (1.14 to 0.51 1/mm, p=0.000), trabecular thickness (0.21 to 0.26 mm, p=0.011), trabecular spacing (0.71 to 1.88 mm, p=0.002), bone surface area (335.85 to 159.43mm, p=0.000), and bone surface to bone volume ratio (9.43 to 7.82 1/mm, p=0.013) in the defect site for the EPC group versus the control group respectively. Biomechanical testing showed that the EPC treatment group had a significantly higher torsional strength compared with the control group (EPC=164.6±27.9 Nmm, Control=29.5±3.8 Nmm; p value = 0.000). Similarly, the EPC treated fractures demonstrated significantly higher torsional stiffness versus controls (EPC=30.3±5.0 Nmm/ deg, Control=0.9±0.1 Nmm/deg; p value = 0.000). When biomechanically compared to contralateral intact limbs, the EPC treated limbs had similar torsional stiffness (p=0.996), but significantly lower torsional strength (p=0.000) and smaller angle of twist (p=0.002).

Conclusion: These results suggest that local EPC therapy significantly enhances fracture healing in an animal model. The biomechanical results show that control animals develop a mechanically unstable non-union. In contrast, EPC therapy results in fracture healing that restores the biomechanical properties of the fractured bone closer to that of intact bone.

Purpose: The purpose of this study was to assess the safety and efficacy of computed tomography (CT) guided percutaneous radiofrequency (RF) ablation of osteoid osteoma by using the water-cooled probe.

Patients & Methods: During the period from July 2002 to February 2006, fifty-one patients with osteoid osteomas localized in femur (30), tibia (9), calcaneus (2), talus (2), metatarsus (2), humerus (1), sacrum (1), scapula (1), olecranon (1), patella (1) and thoracic vertebra (1) were treated with CT-guided RF ablation using the Cooltip™ Tyco Healthcare probe. Mean age was 20 (range, 3.5 to 57) and male to female ratio was 35/16. Mean follow-up period was reported 22 months (range, 8 to 50 months). The procedures were carried out under general anesthesia and the patients were discharged from the hospital within 24 hours.

Results: Technically, all the procedures were performed successfully. Pain disappeared postoperatively in all the patients within 2–3 days and no patients needed analgesic treatment after a week. All patients were allowed fully weight bear and function without limitation after the procedure. Recurrence of the pain was observed in one patient who was treated successfully with a second ablation. Our primary and secondary clinical success rates were 98% and 100% respectively. In one case, wound infection was observed after the procedure as the only post-operative complication in our series.

Conclusion: CT-guided percutaneous RF ablation of osteoid osteomas using the water-cooled probe is a safe, effective and minimally invasive procedure with high success rate and lack of relapses.

Background: The purpose of this study was to analyze the applicability and advantages of the intraoperative use of a mobile isocentric C-arm with 3-dimensional imaging (SIREMOBIL ISO-C-3D) in fixation of intraarticular fractures.

Methods: Intraoperative CT-quality visualization was performed on a series of 72 closed-intraarticular fractures in 70 patients following fixation. Fracture distribution was; calcaneus (25), tibial plateau (17), tibial plafond (12), acetabulum (11), distal radius (3), ankle (3), femoral head (l). The mean patient age was 41. Intraoperative revision was performed based on the additional information Iso-C-3D provided beyond routine fluoroscopy used for fracture reduction and fixation. The primary outcome measure was revision rate after final Iso-C-3D data acquisition and prior to wound closure. Secondary objectives were to measure the additional time required for Iso-C-3D use and to determine the rate of further re-do surgeries.

Results: Eight out of 70 (11%) fracture fixations were judged by the surgeon to require intraoperative revision following Iso-C-3D imaging. In 7 cases this was due to hardware misplacement and in 1 this was for intraarticular loose fragment. Prior to leaving the operating room, the surgeon was satisfied with fracture alignment in all the procedures. The mean additional operative time using Iso-C-3D was 7.5 minutes. No patient required re-do surgery.

Conclusion: Intraoperative 3-dimensional visualization of intraarticular fractures enables the surgeon to identify inadvertent malreductions or implant malpositions which may be overlooked by routine C-arm fluoroscopy and hence eliminates the need for re-do procedures. Iso- C-3D adds little operative time and may preclude the need for preoperative and postoperative CT-scans in selected cases.

Background: The purpose of this study is to evaluate the applicability and advantages of the intraoperative use of a mobile isocentric C-arm with 3-dimensional imaging (SIREMOBIL ISO-C-3D) in trauma surgery.

Patients & Methods: Between November, 2004 and September, 2005, the ISO-C-3D was used at our institution for intraoperative CT-quality visualization of 33 trauma cases with the fractures of calcaneus (13), tibial plateau (7), tibial plafond (6), acetabulum (4), distal radius (2) and talus (1). The mean patient age was 42 and male to female ratio 25 to 8. In 30 cases ISO-C-3D was used during the surgery after the reduction and fixation of the fracture to assess the accuracy of reduction and implant position prior to wound closure and in 3 cases the device was used before starting the operation to obtain real-time CT images which were transferred to a navigation system to perform computer navigated procedures.

Results: This novel technique was highly beneficial from 4 aspects; intraoperative diagnosis, proper reduction, correct implant placement and feasibility in combining the CT images to computer navigation. In 40% of the cases (13/33) who had no regular CT scan before the surgery, intraoperative three dimensional imaging with ISO-C-3D has been a superior modality in diagnosis. In one case the reduction and implant position was corrected during the surgery after the ISO-C-3D scan. In all the procedures with ISO-C-3D navigation, satisfactory reconstruction of the articular surfaces with precise fixation was achieved.

Conclusion: Intraoperative 3-dimensional visualization with ISO-C-3D provides useful information in trauma surgery which enables the surgeon to re-evaluate the injury diagnostically and to judge the reduction and implant position before wound closure. Combining the ISO-C-3D images with computer navigation makes the reduction and implant placement highly accurate.

Background: The purpose of this retrospective study was to analyze the results of closed intramedullary fixation of pathological humeral shaft fractures with unreamed humeral nail (UHN).

Patients & Methods: Nine patients who had ten pathological fractures of the humeral shaft secondary to metastatic disease were included in the study. All fractures were stabilized with unreamed humeral nailing with use of a closed anterograde technique. The mean patient age was sixty-three (range, fifty to 78), male to female ratio 1:8 and left humerus was involved in five, right in three patients and one patient had bilateral pathological humeral shaft fracture.

Results: The blood loss was unremarkable in seven patients (8 procedures). Two patients were given totally 3 units of pack cells after the surgery and these were the only patients who had additional surgeries during the same operation due to their additional pathological fractures. The mean duration of hospitalization after the operation was 6.5 days (range, two to 16 days). All of the ten extremities had a return to nearly normal function within 6 weeks after nailing. Relief of pain was rated as good in all but one patient. Seven patients received adjuvant therapy during the 3 months period before and after the procedure. Five patients died at a mean of 3.5 months (range, one to 9 months). There were no early or late complications related to surgery except one patient who developed cellulitis after the surgery. The fracture was united in all of the extremities in patients who survived for at least 3 months and had radiographs available.

Conclusion: Unreamed humeral nailing of the pathological humeral shaft fractures provides immediate stability and pain relief, minimum morbidity and early return of function to the extremity.