Introduction: A good cup positioning requires reliable anatomical landmarks expecially for navigation. The anterior pelvic plane (APP) seems to be a good reference for navigation because it is in relation with pelvic tilt which do affect the position of the cotyle and consequently the position of the cup. The value of this plane is not well known according to gender, age, weight… The aim of the study is to assess radiologically the APP in standing and supine position before and after total hip arthroplasty.

MATERIALS AND Methods: 92 Patients (32 males, 60 females, mean age 65 years) underwent strict lateral X-rays in standing and supine standardized position. Uninterpretable or unsatisfying X rays were withdrawn. 45 patients underwent a standing X-ray, 24 a supine X-ray, 21 a supine and standing X ray. Statistical analysis used a Student t-test.

Results: Non matched values showed a retroversion of the pelvis of 6.4° (+/− 6.9) in supine position, 0.3° (+/− 7.4) in standing position. Matches values showed an retroversion of the pelvic of 6.9° (+/− 5.3) in supine position, 0.3° (+/− 5.03) in standing position (significant difference). Extreme values varied from −15° to + 18° (3 patients showed no variation, 2 patients a retroversion from supine to standing position). There was no statistical difference between male and female but a statistical differences in females.

Discussion: The APP is easily assessable by X rays in standing as in supine position. Bony landmarks of the plane are also assessable by navigation tools and to can be a good plane as reference. Several authors showed the repercussion of the pelvic tilt on the cotyle position. The difference between standing and supine position is about 6°. But for some patients the difference is may be of 20°and that could explain some impigment and instability. A cup well positioned in supine position may be not so good in standing position because of the pelvic tilt.

Conclusion: The value of the APP is important to know before THA and seems to be a good plane as reference for navigation.

Purpose of the study: Percutaneous compression plating (PCCP) is a new method for minimally invasive fixation of intratrochanteric fractures. Fixation is achieved with two neck screws and a 3-hole plate. This prospective study of a non-randomized series was designed to compare results in a monocentric cohort of patients treated by PCCP or dynamic hip screw (DHS).

Material and methods: From September 2003 to December 2004, all patients presenting an A1 (75.8%) or A1 (24.2%) (AO classification) intratrochanteric fracture were treated with PCCP (n=37) or DHS (n=20). Female gender predominated (86.5%) in this elderly population, mean age 83.2 years. The following variables were studied: operative time, radiation time, blood loss, hemoglobin level, blood transfusion, bone healing, complications, quality of the reduction.

Results: Mean follow-up was 8.3 months. The two groups were similar regarding bone healing, functional outcome and mortality. Intraoperative blood loss was less with PCCP (63 ml) than with DHS (120 ml). Mean fall in hemoglobin level was 2 after PCCP and 3 after DHS. The transfusion rate was 28% for PCCP and 40% for DHS. Mean operative time was 50 for PCCP and 30 minutes for DHS. Men radiation exposure was 4 minutes for PCCP and 1 minute for DHS. The positions of the screw (DHS) and the two PCCP screws were considered good for 68% of the PCCP and 75% of the DHS, acceptable for 29% PCCP and 20% DHS, and poor for 3% PCCP and 5% DHS. Complications were similar (one disassembly in each group).

Discussion: Although this was a preliminary study, PCCP was found to provide an attractive alternative for the treatment of intratrochanteric fractures. Results are similar to those obtained with the DHS but with a less aggressive method (limited approach, less blood loss). A learning curve (at least 10 implantations) appears indispensable to achieve maximum skill. The main drawback is the duration of the radiation. This implant would not be acceptable for subtrochanteric fractures which would require another type of implant.