Biomechanical and dinical studies of anatomical reconstruction of posterior wall of the acetabulum with self ilium / 中华创伤杂志

ABSTRACT

Objective To design a new method of posterior wall reconstruction for severely corn-minuted and obsolete fracture of the posterior wall of the aeetabulum. Methods (1) Biomechanical study (from two perspectives the stability and the stress distribution on the femoral head and the acetabu-lure) six fresh adult' s pelvis and femur specimens were collected and divided into experimental group ( consisted of the left sides) and control group ( consisted of the right sides). After the defects of the pos-terior wall were made, the defects were anatomically reconstructed with the harvested ilium by acetabular tridimentional memory fixation system (ATMFS) in the experimental group, whereas the acetabular frag-ments were repositioned to the defect sites and fixated by the plates and screws in the control group. Lon-gitudinal and latitudinal displacement, stability of the anatomically reconstructed posterior wall of the ace-tabulum, the fitness of femoral head to the acetabulum after anatomical reconstruction and mean and maxi-mum pressure of anterior wall, posterior and cupuh of the acetabuhm were analysed and compared. (2) Cinical study The posterior wall defect on the harvested ilium piece was repaired with 3-directional loc-king of ATMFS in 10 male patients (at age of 16-50 years, mean 36.4 years) from January 2000 to June 2002. There were seven patients with flesh acetabular fractures and three with old acetabular fractures.The period from fracture to reconstruction for the patients with old fractures was 58-251 days ( 137.7 days an average). The patients were foUowed up for 5.8 years (average 5.2-7.1 years). Results (1) Biomechanical study showed no statistical difference upon stability and fitness of femoral head to acetabu-lum after reconstruction in experimental and control groups. (2) Clinical study postoperative X-ray film showed no repeated displacement of the fracture and the patients began out-of-bed movement with weight bearing after 1.6 months (1.2-2.1 months). Heterotopic ossification was found in two patients, with no influence on the joint function. According to the elinieal ranking standard of Modified d' Aubigne and Postal, the excellence rate was 93%. Conclusions Anatomical reconstruction of posterior wall of the acetabulum by using serf ilium with ATMS has good stability and stress distribution of the femoral head and the reconstructed acetabulum in clinical application and offers a new method for treatment of severely comminuted and obsolete fracture of posterior wall of acetabulum.