Venting in closed femoral nailing: A simple technique using a frazier suction tip.

A surgical technique to drain the medullary content during closed femoral nailing by using a Frazier suction tip as a vent is demonstrated. This method is simple, safe and reproducible. The medullary content can be drained outside without surrounding soft tissue contamination and the intramedullary pressure is possibly minimized when femoral canal reaming and nail insertion is performed.

3D geometrical assessment of femoral curvature: a reverse engineering technique.

OBJECTIVE: Investigate the 2D/3D geometry of femoral curvature and femoral length using the advanced technique of computerized tomography combined with reverse engineering techniques. MATERIAL AND METHOD: The present study was performed using reverse engineering technique based on CT data of 99 cadaveric femora. The femur was divided into three segments, proximal, mid-shaft, and distal regions by defining 35% and 65% of the femoral total length as a boundary of each region. The intramedullary canal in the mid-shaft region was mainly extracted to determine the set of circular center, which could consequence to approximate the 3D femoral radius of curvature using the 3D least square best fit. The 3D femoral curvature was then projected into A-P and M-L directions to investigate the correlation of 2D/3D femoral curvature as normal radiographic images. RESULTS: It was found that the average 3D Thai femoral curvature was 895.46-mm (SD = 238.06) and the average femoral total length is 421.96-mm (SD = 27.61). In addition, the 2D femoral curvature derived from sagittal radiographic image can be used to determine the 3D femoral curvature with this equation: R3D = RSagittal + 3.67 with r = 0.987. CONCLUSION: This described technique is a non-destructive method that can effectively assess the internal/ external 3D geometric data of the femur The obtained data is useful to develop a proper design of prosthesis that required inserting into the intramedullary canal. From the present study, it can be concluded that the 2DSagittal femoral curvature derived from standard radiographic image can be represented for the 3D femoral curvature.

Radiation scattering to the primary surgeon during closed locked femoral nailing.

A prospective study of the radiation exposure to the primary surgeon during closed static locked femoral nailing was performed in 50 cases. There were 44 males and 6 females whose ages ranged from 15 to 70 years (average, 32). The degree of fracture comminution was classified by Winquist. The cases included 1 Winquist (WQ)1, 9 WQ2, 27 WQ3 and 13 WQ4. The Grosse-Kempf femoral nail was used in 40 cases and the AO interlocking femoral nail was used in 10 cases. The C-arm image intensifier model Phillip BV212 and BV 300 were used during the present study. The average operation time was 52 minutes (range, 30 to 120). The fluoroscopic time for the entire procedure average 132 seconds (range, 23 to 366). The radiation exposure to the primary surgeon ranged from 2 to 231 micro-Sv with an average of 30 micro-Sv per procedure. From the present study, it was found that radiation scattered to the primary surgeon during current practice for closed static femoral nailing using the recent model of C-arm image intensifier was minimal and far below the permissible dose. It was also found that the group using the C-arm model BV 300 (n = 16) had significant lesser fluoroscopic time and less radiation scattering to the primary surgeon than the group with model BV 212 (n = 34).

Fit-and-fill analysis of trochanteric gamma nail for the Thai proximal femur: a virtual simulation study.

The present study present a three-dimensional virtual simulation method to evaluate the fit-and-fill effect of the insertion of a trochanteric gamma nail (TGN) in 98 Thai dadaveric proximal femora. The circular best fit of the 2-dimensional cross-section of the femoral canal and the nail at 4 levels [d100, d120, d140 and d160] which were located at 100, 120, 140 and 160 mm distal to the tip of the greater trochanter were calculated. The evaluation of each level included, 1) the diameters of the medullary canal, 2) the percentage of area filled by the nail in the unreamed medullary canal, 3) the minimal reamer diameter that required enlargement of the canal to accommodate TGN insertion, 4) the minimal inner cortical reaming thickness that needed to be removed, 5) the percentage of cortical bone area that needed to be removed prior to nail insertion and 6) the deviation of the nail center from the center of the medullary canal. The results showed that at 4 studied locations the diameter of unreamed medullary canal averaged 10.3 to 11.8 mm. The nail cross-section that could fill the medullary canal averaged 86.9-95.1%. The minimal reaming diameter for the medullary canal to accommodate the TGN insertion averaged 11.3 to 12.3 mm. The inner cortical thickness that should be removed averaged 0.6 to 0.8 mm. The cortical bone that needed to be removed averaged 13.6 to 19.3% of the total cortical area. The deviation of the nail center from the canal center averaged 0.3 to 0.8 mm. The present study showed some mismatching of the TGN to that of the Thai proximal femur. Appropriate reaming to prepare the medullary canal should be considered prior to TGN insertion to prevent technical problem. Future re-design of the implant may be considered for Thai patients.