Hendrik Jansen

Background Complicated tibial fractures with severe soft tissue trauma are challenging to treat. Frequently associated acute compartment syndrome can result in scarring of muscles with impaired function. Several studies have shown a relationship between angiogenesis and more effective muscle regeneration. Vascular endothelial growth factor (VEGF) is associated with angiogenesis but it is not clear whether it would restore muscle force, reduce scarring, and aid in muscle regeneration after acute musculoskeletal trauma. Questions/purposes Therefore, we asked whether local application of VEGF (1) restores muscle force, (2) reduces scar tissue formation, and (3) regenerates muscle tissue. Methods We generated acute soft tissue trauma with increased compartment pressure in 22 rabbits and shortened the limbs to simulate fracture débridement. In the test group (n = 11), a VEGF-coated collagen matrix was applied locally around the osteotomy site. After 10 days of limb shortening, gradual distraction of 0.5 mm per 12 hours was performed to restore the original length. Muscle force was measured before trauma and on every fifth day after trauma. Forty days after shortening we euthanized the animals and histologically determined the percentage of connective and muscle tissue. Results Recovery of preinjury muscle strength was greater in the VEGF group (2.4 N; 73%) when compared with the control (1.8 N; 53%) with less connective and more muscle tissue in the VEGF group. The recovery of force was related to the percentage of connective tissue versus muscle fibers. Conclusions Local application of VEGF may improve restoration of muscle force by reducing connective tissue and increasing the relative amount of muscle fibers. Clinical Relevance VEGF may be useful to improve skeletal muscle repair by modulating muscle tissue regeneration and fibrosis reduction after acute trauma.

OBJECTIVE: To determine the results and complications of treating supracondylar fractures of the femur with external fixation. DESIGN: Retrospective follow-up from the time of injury (inception cohort) to an average of thirty-one (range thirteen to seventy-two) months after injury. SETTING: Tertiary care university hospital. PATIENTS: All thirteen adult patients with supracondylar femur fractures treated with the method described were included. There were seven closed and five open fractures and five vascular injuries that required repair. Fractures were chosen for this technique on an individual basis by the treating surgeon. INTERVENTIONS: The femoral condyles were reduced percutaneously or via a medial arthrotomy and stabilized with 6.5-millimeter cannulated screws. Fixator pins were placed from lateral to medial in the condyles and in the shaft above the fracture. The monolateral fixator was applied laterally and stabilized the reduced condyles to the shaft. Initial grafts of bone were used in five fractures. External fixation time averaged 127 days. OUTCOME MEASURES: During treatment we determined the occurrence of complications at the pin sites and the fracture site, the time of healing, and the angular alignment at healing. At the latest follow-up we determined the range of motion of the knee, knee stability, a standardized knee score, and on radiographs the occurrence of arthrosis. RESULTS: Twelve fractures healed primarily. One patient had a fracture site infection and required further treatment before healing. Knee flexion was restricted while in the fixator but rapidly recovered after frame removal. At follow-up (average thirty-one months), the range of knee flexion averaged 111 degrees (range sixty-five to 140). The Iowa Knee Score averaged 87 points (range 75-93 points). Four femurs healed with angular malalignments, shortening, or both. Twelve knees had no detectable arthrosis. CONCLUSIONS: We concluded that in select supracondylar femur fractures, monolateral external fixation is a satisfactory treatment alternative.