The effect of compacted cancellous bone grafting on the healing of subchondral bone defects of the medial femoral condyle in horses.
OBJECTIVE
To compare the quality of second-intention healing and that of compacting sternally harvested cancellous bone into subchondral bone defects of the medial femoral condyle in horses.


METHODS
A controlled experiment using a surgical technique that minimizes soft tissue trauma, customized for consistency among horses.


METHODS
Ten horses, aged 2 to 5 years, free of hindlimb lameness and with radiographically normal stifles.


METHODS
After a 12.7-mm-diameter x 19-mm-deep defect was created into randomly selected medial femoral condyles, bone and cartilage healing was evaluated over a 6-month period in control horses (n = 5) and horses receiving a compacted cancellous bone graft (n = 5). Healing was evaluated using lameness assessment, radiographic and microradiographic interpretation, arthroscopic appearance, percent bone fill, proteoglycan content, and histology.


RESULTS
Six months after surgery, there was no significant difference between grafted and ungrafted defects with respect to lameness, radiographic score, or percent bone fill. Histologically, grafted defects were characterized by the presence of dead graft and secondary cyst formation in four defects. Ungrafted defects filled with fibrous tissue and no cyst formation were identified.


CONCLUSIONS
Grafted defects do not heal better than ungrafted defects, and lameness was not affected by surgical technique.


CONCLUSIONS
Cartilage healing is similar in grafted and ungrafted defects in the equine medial femoral condyle at 6 months, suggesting that surgical debridement alone of cystic structures remains the treatment of choice.
Jackson
W A
WA
Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing 48824-1314, USA.
Stick
J A
JA
Arnoczky
S P
SP
Nickels
F A
FA
D000818:Animals; D001182:Arthroscopy / Q000662:veterinary; D001845:Bone Cysts / Q000503:physiopathology / Q000601:surgery / Q000662:veterinary*; D016025:Bone Transplantation / Q000662:veterinary*; D005269:Femur / Q000502:physiology* / Q000601:surgery; D006734:Horse Diseases / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D006736:Horses; D007592:Joint Diseases / Q000503:physiopathology / Q000601:surgery / Q000662:veterinary*; D007794:Lameness, Animal; D011859:Radiography; D011897:Random Allocation; D013264:Stifle / Q000502:physiology / Q000601:surgery; D016896:Treatment Outcome; D014945:Wound Healing