Treatment of subchondral cystic lesions of the medial femoral condyle of mature horses with growth factor enhanced chondrocyte grafts: a retrospective study of 49 cases.

This study evaluated the effectiveness of grafting growth enhanced cells and growth factor (chondrocyte and insulin-like growth factor-I) to treat subchondral cystic lesions in the knee joints (femoral condyle) of horses. Inspecting a total of 49 cases, the researchers concluded that this treatment method is especially beneficial for older horses and those having pre-existing osteoarthritis.

Research Methods

• The study employed a retrospective design to examine the medical records of 49 horses, all of which were suffering from subchondral cystic lesions (SCLs) in the femoral condyle, a part of the horse’s knee joint. These horses were treated by surgical cleansing (debridement) and implantation of grafts containing chondrocytes (cartilage cells) and insulin-like growth factor-I (IGF-I), a growth factor stimulating cell proliferation.
• Each case had preoperative radiographs taken and measurements of the cyst and femoral condyle size were established for ratio calculations. The bone voids left by the cysts were then filled with either autologous cancellous bone (from the same individual) in 45 instances or tricalcium phosphate granules in 4 cases.
• To implant the grafts, a syringe was used that had a mixture of fibrinogen and chondrocytes in one chamber and calcium-activated bovine thrombin alongside IGF-I in the other. A successful treatment was defined as a horse returning to their intended use without any signs of lameness.

Research Findings

• Out of the 49 study subjects, treatment deemed successful was administered to 36 horses, which is approximately 74 percent. Preoperative radiography was conducted on all horses. Thirty-three had unilateral SCLs of the medial femoral condyle, 15 had bilateral SCLs on the medial side, and one had bilateral SCLs on the lateral side.
• The median age for the subjects was 3.3 years, and 15 horses had preoperative radiographic and arthroscopic evidence of osteoarthritis.
• The study’s results indicated that the age of the horse, the presence of pre-existing osteoarthritis, or the initial size of the subchondral cyst didn’t influence the success of the graft treatment.
• Specifically, the treatment was successful in about 80% of the horses who were older than 3 years and in the same percentage of those presenting osteoarthritis.

Conclusions

• The researchers concluded that grafting chondrocytes supplemented with IGF-I is an efficient treatment for horses suffering from SCLs in the femoral condyle. The treatment seems to work best for older horses and those with pre-existing osteoarthritis.
• The study also suggests that chondrocyte implantation might offer better long-lasting results for older horses and horses with osteoarthritis compared to just performing cyst debridement alone.