Objective: To evaluate and compare healing, with and without the use of bone graft, of the gap created during tibial tuberosity advancement (TTA).

Study Design: Prospective study and case series.

Animals: Dogs treated with TTA (n=67).

Methods: Prospective study: Mediolateral radiographic projections (6 weeks and 4 months) after TTA without use of bone graft (group I, n=14) were compared with radiographs of consecutive TTA in which the gap was filled with autologous cancellous bone graft (group II, n=14). Two scoring techniques (A, B) were used. Score A was used to grade the overall osteotomy healing (0=no healing, 4=healed osteotomy). Score B evaluated, independently of each other, healing in 3 sites: proximal to the cage (B1), between cage and plate (B2), and distal to the plate (B3). Case series: nongrafted TTA (4–25 weeks, n=39) were evaluated for healing (Score A). Data was analyzed using t-tests and ANOVA. Significance was set at P≤.05.

Results: Prospective study: Score A, B2, and B3 showed no difference in healing between groups at 6.8 weeks and 4.2 months. Score B1 revealed, in both rechecks, a significantly higher density in group II. Case series: Radiographs at 11.59±5.99 weeks scored 3.3 (2–4). No healing related complications were observed.

Conclusion: The osteotomy gap created during TTA healed within expected time regardless of bone graft use.