Intertrochanteric fractures may occur in a bone with a wide medullary canal that may lead to significant mobility of a intramedullary nail, contrary to an extramedullary device. This study evaluates the Dynamic Hip Screw and the gamma nail in AO 31.A2.1 fractures in these circumstances. Synthetic femora with canals drilled to 18 mm were used. Five fixation types were examined: a 2 - hole and a 4 - hole Dynamic Hip Screw with a 2 - hole plate, a standard gamma nail with dynamic and static distal locking and a long gamma nail. The specimens were tested with cyclic axial loading, from 500 N increasing of 50 N increments in each cycle. Force at failure, overall stiffness, stiffness at the fracture site, location and mode of failure were recorded. The short gamma nails dislocated into varus under preload because the nail migrated laterally. The Dynamic Hip Screw was initially stable, but some specimens rotated around the lag screw. The gamma nail was rotationally stable. Both implants failed through femur fracture. The long gamma nailed failed by screw cut - out at forces lower than the ultimate force of the short gamma nail. This study shows that the gamma nail is unstable in a large medullary canal but offers better rotational stability of the proximal fragment. A modification of the nail design or the operative technique may be considered.

The position of the fovea of the femoral head is usually considered to be inferior or inferoposterior, despite the fact that few detailed anatomical studies have been performed. This study was performed to assess the position of the fovea in computed tomography and its correlation with standard radiographic measures of the proximal femur.

A case series of seven children and adolescents who underwent secondary nerve grafting of median or ulnar nerve is presented. The children were evaluated after a mean follow-up of 7 years, using the Disabilities of Arm Shoulder and Hand (DASH) questionnaire and the Rosen-Lundborg outcome scale. The mean DASH outcome was 14.6 and the mean Rosen-Lundborg score was 2.08. A similar study was conducted for comparison in an adult group, with a mean DASH score of 46.3 and Rosen-Lundborg score of 1.3, indicating superior treatment results in children. The treatment outcome after nerve grafting in children did not match, however, to those obtained in the primary suture group.

Biphalangealism of the toes is an exclusively human phenomenon. The aim of this study was to evaluate the development of the lateral toes in childhood by following the ossification pattern of the phalanges.

This study compares the strength of the native bone-cement bond and the old-new cement bond under cyclic loading, using third generation cementing technique, rasping and contamination of the surface of the old cement with biological tissue. The possible advantages of additional drilling of the cement surface is also taken into account. Femoral heads from 21 patients who underwent a total hip arthroplasty performed for hip arthritis were used to prepare bone-cement samples. The following groups of samples were prepared. A bone—cement sample and a composite sample of a 6 weeks old cement part attached to new cement were tested 24 hours after preparation to avoid bone decay. Additionally, a uniform cement sample was prepared as control (6 weeks polymerization time) and 2 groups of cement-cement samples with and without anchoring drill hole on its surface, where the old cement polymerized for 6 weeks before preparing composite samples and then another 6 weeks after preparation. The uniaxial cyclic tension-compression tests were carried out using the Zwick-Roell Z020 testing machine. The uniform cement sample had the highest ultimate force of all specimens (n = 15; R_m = 3149 N). The composite cement sample (n = 15; R_m = 902 N) had higher ultimate force as the bone-cement sample (n = 31; R_m = 284 N; p <0.001). There were no significant differences between composite samples with 24 hours (n = 15; R_m = 902 N) and 6 weeks polymerization periods (n = 22; R_m = 890 N; p = 0.93). The composite cement samples with drill hole (n = 16; R_m = 607 N) were weaker than those without it (n = 22; R_m = 890 N; p < 0.001). This study shows that the bond between the old and new cement was stronger than the bond between cement and bone. This suggests that it is better to leave the cement that is not loosened from the bone and perform cement in cement revision, than compromising bone stock by removal of the old cement with the resulting weaker cement-bone interface. The results support performing cement-in-cement revision arthroplasty The drill holes in the old cement mantle decrease cement binding strength and are not recommended in this type of surgery.