• Journal of Veterinary Clinics
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• v.23 no.3
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• pp.291-299
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• 2006

During long bone lengthening, there are many disadvantages including axial deviation, malalignment and re-fracture which are commonly encountered inspite of its proven abilities. To study the effects of intramedullary K-wire application on the lengthening of long bone, ten skeletally mature mongrel dogs were separated into two groups(Group I, II). Right femurs of group I(5 dogs) were fixed with only monolateral external fixator after subperiosteal osteotomy. Right femurs of group II(5 dogs) were fixed with mono lateral external fixator and intramedullary K-wire after subperiosteal osteotomy. Lengthening was started at 7 days after the surgery with the rate of 0.5 mm per day for 5 weeks and the dogs were sacrificed after 15 weeks postoperatively to examine histologic differences and evaluate bone mineral density. Radiographic examination at an interval of two weeks was done to evaluate the type of callus formed and to analyze complications including instability of external skeletal fixation and axial deviation. Bone mineral density at the lengthened area and contralateral nonlengthened area were measured using quantitative computerized tomography. Histological examination of regenerated bone was performed using Masson's trichrome stain method. The radiographs demonstrated poor callus formation, higher incidence of axial deviation and screw loosening in the group I compared to the group II. The bone mineral density at the lengthened area in the group II was higher than that of the group I(P<0.05). Histological examination showed that the new bone trabeculae in the group II were greater than that of the group I. In conclusion, the combination of monolateral external fixator and intramedullary K-wire can prevent pin loosening, axial deviation and reduce healing period in dogs.

• Korean Journal of Veterinary Research
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• v.42 no.3
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• pp.411-418
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• 2002

Thirty rabbits underwent femoral lengthening using monolateral external fixator to evaluate results and complications of limb lengthening. Twenty rabbits survived until consolidation of callus formed at the lengthening site after finishing lengthening. Ten rabbits were sacrificed during femoral lengthening because of complications. Survived 20 rabbits were classified to two groups according the amount of lengthening: group I (10% lengthening of the femoral length); group II (20% lengthening). There was no significant difference of consolidation time between two groups (p=0.25). Varus angulation at the lengthening site occurred in 60% of two groups and the amount of varus angulation in group II was larger than that of group I. Degenerative change of articular cartilage at the medial condyle of the distal femur was found in 30% of group II. Of sacrificed ten rabbits, 5 had pin loosenings with pull an of pins from the femur, 2 had fermoral fractures around the pin-tract site, and 3 had severe osteomyelitis of the femur around the pin-tract site.