Correlation between Anterior and Posterior Obliquity of the Sliding Lag Screw and Stability in Unstable Intertrochanteric Fractures

PURPOSE: To investigate the characteristics of the sliding pattern of the proximal fragment (head and neck) in unstable intertrochanteric fractures, which were fixed with a dynamic hip screw (DHS) with anterior to posterior or posterior to anterior insertion angle in the axial view. MATERIALS AND METHODS: AO type A2.1 intertrochanteric fracture was reproduced in 10 proximal femur model (Synbone, Malans, Switzerland). Five fractured models were reduced and fixed using DHS with anterior to posterior insertion angle (group 1) and five models were fixed with posterior to anterior angle (group 2). Load of 500 N (30 cycles) was applied to the fracture fragment-plate complex using Instron 6022. Data on the distance of sliding and the angle of rotation of the proximal fragment were collected and analyzed. RESULTS: No significant difference was noted statistically in the distance of sliding between the two groups (p=0.92). However, the mean angle of rotation was 13.4degrees and 8.0degrees in group 1 and 2, respectively and the difference was statistically significant (p=0.012). Anterior cortical fracture of distal fragment was noted in 3 cases of group 1. There was no fracture of the anterior cortex in group 2. CONCLUSION: In unstable intertrochanteric fracture, the insertion angle of the lag screw in axial view does seem to play a role in the fate of bone-plate complex. Early eccentric contact of both fragments caused rotation of the proximal fragment in all cases and anterior cortical fracture of the distal fragment in 3 cases of group 1.

Chondroblastoma in Hand: A Case Report / 대한정형외과학회잡지

A 25 year-old man complained of pain at the distal interphalangeal joint of the middle finger for 3 months. The radiographs revealed an unicondylar osteolytic lesion at the head of middle phalanx. Enchondroma was initially suspected and curettage was performed, and final diagnosis was chondroblastoma. The size of the lesion increased and multiple septation developed at 9 months follow up. Curettage and bone graft was performed. Radiologic improvement was observed at 1 year after operation. Chondroblastoma developing at the phalanx is first report in our country, and this report can serve as a reminder at the diagnosis of osteolytic lesion in hand.