[Treatment of distal femur fracture by less invasive stabilization system-distal femur].
OBJECTIVE
To investigate the therapeutic effects and the related factors during operation of the less invasive stabilization system-distal femur (LISS-DF)for Types 33A3, C2 and C3 fractures classfied on the criteria by Association of Orthopedics (AO).


METHODS
From August 2004 to December 2005, 26 patients with distal femoral fractures were surgically treated by LISS-DF, including 9 patients with Type 33A3, 11 with Type 33C2, and 6 with Type 33C3. There were 15 males and 11 females, aged 32-72 years (average, 55 years). The fractures occurred on the left side in 16 patients and on the right side in 10 patients. The fractures resulted from a road traffic accident in 12 patients, a fall from the height in 9, and a crush injury in 5. Of the 26 patients, 3 had an open fracture (2 Gustilo Type I, 1 Gustilo Type II A), with the mean time between the injury and the operation of 4 days (range, 6 h-16 d). The operation through a lateral para-patellar incision and a trans-articular retrograde plate of osteosynthesis (TARPO) was performed on 17 patients for Type 33C2 and 33C3 fracture of the distal femur. The locking head screw (LHS) insertion through the stab incisions and monocortical fixation was performed on 9 patients for Type 33A3 fracture.


RESULTS
The follow-up of all the patients for 12-26 months averaged 14.5 months revealed that the bone union was completed in all the 26 patients, 1 of whom had a delayed bone union. The X-ray films showed that the time for the bone union was 11-36 weeks averaged 16.1 weeks, and the time for the full weight loading was 13-26 weeks averaged 17.6 weeks. Superficial infection developed in 1 patient, and the infection was cured after the dressing changes. The internal fixator attachment was performed on 5 patients 6-13 months after operation, who had a serious pain in the lateral part of the distal femur. No deep infection, loosening of the internal fixation, breakage or failure of the implants was found in all the patients. Evaluated by the Merchant score system for the knee joint, of the 26 patients 13 achieved an excellent result, 11 achieved a good result, and 2 achieved a fair result, with 92.3% excellent and good results. Based on the Rasmussen criteria for the fracture reduction, the 26 patients had standard scores of 12-19 with an average of 17.6; of the 26 patients, 16 had an excellent result, 9 had a good result, and 1 had a fair result.


CONCLUSIONS
The LISS is consistent with the principles of biological osteosynthesis on the design, and the system offers a new and effective internal fixation method for treatment of AO Types A3, C2 and C3 fractures. However, its operation indications and operating instructions should be strictly followed.
Ru
Jiangying
J
Department of Orthopedic Surgery, Jiangsu Provincial Corps Hospital of Chinese People's Armed Police Force, Yangzhou Jiangsu, 225003, PR China. rujiangying@163.com
Hu
Yuhua
Y
Liu
Fan
F
D000328:Adult; D000368:Aged; D001860:Bone Plates; D001863:Bone Screws; D005260:Female; D005264:Femoral Fractures / Q000145:classification / Q000601:surgery*; D005500:Follow-Up Studies; D005593:Fracture Fixation, Internal / Q000295:instrumentation / Q000379:methods*; D017102:Fracture Healing; D005597:Fractures, Open / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures; D019651:Plastic Surgery Procedures / Q000379:methods; D013978:Tibial Fractures / Q000601:surgery; D016896:Treatment Outcome