Aim: The PASA (proximal articular surface angle) is a very useful measurement of the hallux metatarsal articular orientation for the preoperative evaluation and the selection of the surgical procedure. The measurement of PASA is found to be dependent mostly to the evaluator. The spatial orientation of the hallux can affect the measurement of PASA. In this study we try to evaluate the effect of pronation and the inclination of the first metatarsal on the measurement of PASA in 10 cadaver first metatarsals.

Material and Methods: The study is made on 10 cadaver first metatarsals. The metatarsals are fixed to a device. The metatarsal inclination and pronation of the metatarsal can be changed by this device. 15-30-45 degrees inclination and 0-10-20 degrees pronation are applied to the metatarsals. After applying radio opaque putty to the medial and lateral articular edges; metatarsal dorsal diaphysial ridge, the x-ray and digital images are taken at different degrees of inclination and pronation. The measurement of PASA is done by graphic software on computer. The statistical analysis is performed by paired sample T-test.

Results: We found that changing the inclination has no effect on PASA (p> 0.1). The pronation of first metatarsal has found to have a positive effect on PASA (p< 0.005). As the degree of pronation increases, the degree of PASA is found to be increased also. No difference was found between the measurements of x-ray and digital photography images.

Discussion: Inclination of the first metatarsal can change depending on the height of the medial longitudinal arch. By this experimental study we tried to simulate the pes cavus and pes planus deformity on the radiologic measurement of the hallux by modifying the inclination and pronation of the first metatarsal. According to the current study, inclination has no effect on measurement of PASA. Pronation of the first metatarsal accompanies some hallux deformities. As pronation influences the measurement of PASA, the current data suggests that the measurement of PASA is not suitable for making clinical and surgical decisions.

Aim: Bone grafts and bone graft substitutes are often used at radical surgical procedures such as; trauma, congenital anomalies, tumor surgery, bone infections, revision arthroplasty surgery, spinal surgery. However autograft and allograft bone are frequently used, they have some limitations. ABM/P-15 (Pepgen P-15) is a combination of anorganic bovine derived hydroxyapa-tite matrix coupled with a synthetic-cell binding peptide (P-15). This tissue engineered particulate bone replacement graft has been established for the treatment of periodontal osseous defects. The aim of this study is to determine the effect of ABM/P-15 on the healing of a critical sized segmental defect in rat radius.

Methods: 36 Wistar rats were used at this study. A critical sized segmental defect was created in each rat radius. 13 defects were filled with ABM/P-15 Flow (putty form), 12 defects were filled with ABM/P-15, and 11 defects were used as a control group. The rats were killed at 10 weeks. The healing of defects was evaluated with radiographic and histological studies.

Results: The use of ABM/P-15 and ABM/P-15 Flow were demonstrated improved healing of segmental bone defects in rat radius on radiographic and histological studies compared with control group. Statistical evaluation showed that there were significant differences between control sites, and sites treated with P-15 and P-15 Flow (p< 0.005). The highest radiological and histological grades were achieved by P-15. Osteogenic proliferation was seen at the P-15 group more than P-15 flow.

Conclusion: Segmental cortical bone defects may be treated with ABM/P-15 instead of bone allografts, and autografts. According to the radiologic and histological parameters measured in this study, the implantation of ABM/P-15 resulted in optimum healing of the segmental cortical bone defects.