0.05). CONCLUSION Nebulized 2% lidocaine inhalation is an easy, simple and reliable method of anesthesia for strobolaryngoscopy.

Objective To discuss the therapy for acetabular comminuted fractur e combined with compressive defects. Methods From July 1997 to February 2005, 43 cases of comminuted acetabular fracture combined with compressive defect were t reated. 25 cases were obsolete, 16 fresh, and 2 malformed (90 days after injury) . 34 cases were complicated fractures with defects, and 9 simple fractures with defects. The defect volumes ranged from 3 to 9 cm3, averaging 4.5 cm3. They were treated with ATMFS (acetabular tridimensional memory fixation system) to fixate the comminuted bone fragments tridimensionally. The modified acetabular approac h, reduction of acetabular comminuted articular face, anatomical reconstruction of posterior wall of acetabulum with autogenous ilium, autogenous and artificial bone implantation and bone wax isolation were used. The follow-ups lasted from 5 to 86 months, averaging 15.7 months. Results 31 cases achieved anatomical red uction by filling up the compressive defects. 12 cases were treated by anatomica l reconstruction of posterior wall. On average, 5.3 months after operation, the injured hip joint was as good as the healthy one in 40 cases. Ischemia necrosis of femoral head occurred in 1 case, and 2 cases experienced heterotopic ossifica tion with ischemia necrosis of femoral head which led to osseous fusion of hip j oint. Conclusion The new methods for treatment of acetabular fractures with comp ressive defects elevate the reduction rate of acetabulum and femoral head, and a re effective for the functional recovery of hip joint.

Objective To analyze the causes of postoperative step off of the tibial plateau fracture and to suggest strategies to cope with them. Methods 57 cases of tibial plateau fracture who had been treated operatively in our department from January 2001 to June 2003 with satisfactory reduction of the articular surface were reviewed. Their radiograms were analyzed. Results The follow ups lasted 6 to 30 months (average 15 months). Postoperative step off rate was 28.1%in all the cases according to radiological step off criteria. (A depression of the articular surface more than 3 millimeters or malalignment of the extremity more than 5 degrees is considered as step off.). Six causes of loss of reduction were: 1) more than sixty years of age, 2) severe osteoporosis, 3) preoperative displacement and fracture fragmentation, 4) poor anti shearing strength of screw and plate, 5) loose bonegraft, and 6) premature weight bearing. Conclusions The key points to enhance the outcome include precise judgment of the type of fracture, sufficient amount of bonegraft, rigid internal fixation after anatomic reduction and an appropriate plan for performing early, loadless, functional exercise. The traumatic osteoarthritis may be avoided or deferred if the above mentioned six causes can be taken into full consideration or preventive measures can be taken.