Enhanced fracture and soft-tissue healing by means of anabolic dietary supplementation.

BACKGROUND: Malnutrition is common in hospitalized injured patients. It contributes to delayed fracture-healing and increased morbidity. However, relatively little attention has been directed toward nutritional strategies for augmenting musculoskeletal recovery after a fracture. This animal study was designed to examine the effects of dietary protein intake and the role of conditionally essential amino acids in muscle and bone-healing after a fracture. METHODS: One hundred adult male rats were used. Ten rats served as controls and received a 15% protein diet throughout the study. The remaining ninety rats received a 6% protein diet for five weeks to induce protein malnutrition. The rats underwent intramedullary nailing and closed midshaft fracture of one femur. After the fracture, they were separated into three isocaloric dietary groups. Group P6 received a diet with 6% protein; Group P15, a diet with 15% protein; and group P30, a diet with 30% protein with conditionally essential amino acids. At two, four, and six weeks after surgery, ten animals from each group were killed and the femora were evaluated with dual x-ray absorptiometry, histomorphometric assessment of callus, and torsional testing. The quadriceps muscles were analyzed for total mass, total protein content, and for mRNA expression of insulin-like growth factor-1 (IGF-1), IGF-2, IGF receptors, actin, myosin, and vascular endothelial growth factor (VEGF). RESULTS: The P30 group demonstrated elevations in albumin, body mass, muscle mass, total protein content of muscle, and bone mineral density in the fracture callus compared with the P6 diet group at six weeks (p < 0.05). Molecular analysis of muscle revealed that IGF-1, IGF-2, IGF receptors, myosin, actin, and VEGF gene expression were significantly (p < 0.001) higher in the P6 group compared with the P30 group. Biomechanical testing of the femora, however, showed no significant differences. CONCLUSIONS: Dietary supplementation with conditionally essential amino acids in malnourished animals had anabolic effects on bone mineralization, body mass, and muscle mass.

Anterior trochanteric slide osteotomy for primary total hip arthroplasty. Review of nonunion and complications.

The radiographic results of 73 anterior trochanteric slide osteotomies were retrospectively reviewed at an average of 36 months after primary hip arthroplasty to determine the incidence of nonunion of the trochanter and complications related to trochanteric hardware. In each case, the trochanter was retracted anteriorly, with the gluteus medius and vastus lateralis muscle insertions left intact. Reattachment was performed with 2 monofilament wires or cables passed through the lesser trochanter in each case. Ninety-two percent of the trochanters healed; nonunion was associated with anterior displacement of the trochanteric fragment with external rotation of the femur. The incidence of repeat surgery for hardware-related problems was 28%. Although the slide osteotomy prevented proximal migration of the trochanteric fragment, the incidence of hardware complications was too high to justify the routine use of this approach in primary hip arthroplasty.

Repair or reattachment of the meniscus after fixation of a tibial plateau fracture.

The intact meniscus provides protection for healing of tibial plateau fractures, prevention of early posttraumatic arthritis, and maintenance of knee stability. However, tibial plateau fractures may have associated meniscal injury that may impair this function. In addition, the meniscotibial ligaments are often divided during submeniscal arthrotomy for exposure. Repair or reattachment of the meniscus can be difficult. We describe the technique of using Kirschner wire holes in proximal tibial plates for anchoring the meniscus.

Vacuum-assisted closure complicated by erosion and hemorrhage of the anterior tibial artery.

We report an erosion and hemorrhage of a left anterior tibial artery associated with a vacuum-assisted closure device. To our knowledge, this report represents the first arterial erosion associated with a vacuum-assisted closure device. We estimate our patient lost 6 units of blood. The hemorrhage was complicated by anticoagulation and a traumatic setting. Based on our complication, we believe great care should be taken when placing a vacuum-assisted closure device adjacent to an exposed artery.

Comparison of the response of primary human blood monocytes and the U937 human monocytic cell line to two different sizes of alumina ceramic particles.

It is well recognized that wear particles derived from orthopaedic implants have the potential to induce inflammation, which may eventually lead to aseptic loosening of the artificial joint. We hypothesized that alumina ceramic particles of different sizes cause a differential cytokine response by human monocytes. To test this hypothesis a human monocytic cell line (U937) and primary human blood monocytes obtained from healthy volunteers were exposed to ceramic particles within the range known to be generated in vivo. Cellular responses were measured by quantifying the relative gene expression of 12 different cytokines using TAQman Real-Time Polymerase Chain Reaction (RT-PCR). Our results demonstrate that at a particle to cell ratio of 100:1, 0.5 microm ceramic particles consistently provoked higher amounts of Interleukin-1alpha (IL-1alpha), IL-1beta, IL-8, IL-10 and Tumor necrosis factor-alpha (TNF-alpha) steady state mRNA by U937 cells. As expected, the variability of cytokine expression in primary blood monocytes was much higher compared to the cell line however, a similar trend was observed. These results show a differential response to ceramic particle size, which may imply that 0.5 microm particles are less biocompatible. New ceramic implants can be designed to generate a known particle size range in vivo. Implant materials of this type may induce relatively lower levels of production of inflammatory cytokines resulting in a reduced incidence of failure due to aseptic loosening.