Hemicallostatis provides satisfactory results in high tibial osteotomy with dynamic axial fixator

Bachhal V, et al. J Bone Joint Surg Br. 2011. doi: 10.1302/0301-620X.93B7.26124

Hemicallostasis can achieve precise alignment in high tibial osteotomy procedures using a dynamic axial fixator without tibial slope or patellar height interference and free of serious complications, according to researchers from India.

The researchers investigated 37 knees of 32 patients — mean age of 54.6 years — who underwent hemicallostasis using a dynamic external fixator for treatment of osteoarthritis in the medial compartment of the knee. The researchers hoped to achieve valgus overcorrection of 2° to 8° or a mechanical axis at 62.5%.

The team reported no change in mean range of movement and no statistically significant differences in Insall Salvati index or tibial slope at a mean follow-up of 62.8 months. Further, they reported a change in mean hip-knee-ankle angle from 190.6° to 176° and a mean final position of the mechanical axis of 58.5%.

Overall, the researchers noted 31 of 37 knees displayed the desired alignment — with 21 excellent, 13 good, 2 fair and 1 poor result when the Oxford knee score was applied.

“This score was at its best at 1 year with a statistically significant deterioration at 2 years followed by a small but not statistically significant deterioration until the final follow-up,” the authors wrote.