[The effect of bone marrow ablation on regional biomechanical properties of rat tibia]. / Kemik iligi ablasyonunun siçan tibiasinin bölgesel biyomekanik özellikleri üzerine etkileri.

OBJECTIVES: Regional (metaphyseal-diaphyseal) biomechanical properties of normal rat tibia, and changes on these biomechanical properties after bone marrow ablation, a model of fracture healing, were examined. METHODS: The study included 24 Sprague-Dawley rats that underwent tibial marrow ablation, and eight control rats with no surgical procedure. Proximal metaphyseal, proximal diaphyseal, distal diaphyseal, and distal metaphyseal samples were prepared from the tibias of all rats. In the control group, stiffness (elastic modulus, E), strength (maximum strength, Smax), and toughness (total energy absorption, U) parameters of the regional tibial segments were evaluated under compression loads. In the experimental group, compression was applied following bone marrow ablation on days 1, 3, 7, 9, and 15, and ablation-induced changes in the regional biomechanical properties were studied. RESULTS: The lowest E, Smax, and U values were obtained from the proximal metaphysis. The highest E and Smax values were from the distal diaphyseal, and the highest U values were from the proximal diaphyseal regions. In ablation-induced rats, decreases were observed in all the mechanical test values during days 1 to 7, followed by slight increases on days 7 to 9, and eventual decreases on days 9 to 15. There were significant differences between the two groups with respect to biomechanical parameters (p<0.05), but no significant differences were found between the tibial regions (p>0.05). CONCLUSION: Biomechanically, the most resistant and the weakest anatomic regions of normal rat tibia are the diaphyseal region and proximal metaphysis, respectively. The metabolic changes occurring after bone marrow ablation lead to changes in the mechanical properties of the tibia. The most affected tibial segments from ablation-induced intramedullary injury are the metaphyseal segments.

Results of surgical treatment of intra-articular (ao-c3) distal humeral fractures in adults.

BACKGROUND: The results of intra-articular comminuted distal humeral fractures, which have been treated by open reduction and dual plate fixation, are compared in this study with previously published results. METHODS: At Uludag University Faculty of Medicine Department of Orthopaedics and Traumatology, between 1995 and 2002, the results of 20 cases were evaluated in patients with intra-articular comminuted distal humer- alfractures, who had been treated by open reduction and internal jixation. RESULTS: Eleven (55%) cases were male, nine (45%) were female and mean age was 40.6 (range; 18 to 76). All fractures were C3 type according to AO/ASIF classification. Eight (40%) cases were open fractures and of these, six ( 30% ) were type 3A and 2 ( 1 0% ) were type 3B on the Gustilo-Anderson classification. All the fractures were jixed with dual plate after open reduction. In 25% ~f the cases, superficial wound infection was observed and in 5% heterotopic ossification. CONCLUSION: In adult distal humeral. fractures of type C3, stabilization by dual plate, following open reduction and early commencement of joint movements, has fewer complications and should he the preferred method of treatment. Key Words: Distal humeral, fracture, intra-articular, dual plate. fixation.

[Results of conservative treatment of midclavicular fractures]. / KLAVIKULA ORTA BOLGE KIRIKLARININ KONSERVATIF TEDAVI SONUCLARI.

BACKGROUND: ln this study, we compare the outcome of conservative management by closed reduction and figure of eight bandage in cases of midclavicular fractures with previously published results of other treatment methods. METHODS: In our department between 1997-2002, 37 cases ofmidclavicular fractures having undergone conservative treatment were evaluated. RESULTS: 26 patients (70.2%) were male and the remaining 11 (29.8%) female. The average age was 34.3 years (range; 9 to 65). The claviclefractures were classified according to the Allman classification and all fractures were in group 1. After reduction, a figure of eight bandage was applied. The mean follow-up period was 29.8 months (range; 6 to 48). All the fractures showed a complete union but one case (2.7%). 1n 16.2% of the cases minor cosmetic problems were observed. CONCLUSIONS: We conclude that conservative treatment is the preferred method of treatment in cases of mid-clavicular fractures, unless there is an absolute indication for surgical therapy. This approach is easily applicable, cost effective and has fewer complications. Key Words: Midclavicular fracture, conservative treatment, closed reduction,figure of eight bandage.