Displacement Following Minimally Invasive vs Open Lateralizing Calcaneal Osteotomy: A Direct Comparison in a...

Minimally invasive (MIS) calcaneal osteotomy is increasingly used to decrease soft tissue morbidity, but whether MIS lateral displacement calcaneal osteotomy (LDCO) can achieve similar translation to the open calcaneal osteotomy technique remains unclear.

In a paired cadaveric study, 16 feet from 8 donors were block-randomized so that each pair received 1 open LDCO and 1 MIS LDCO performed by a fellowship-trained foot and ankle surgeon. Lateral translation of the tuberosity was measured directly via a medial approach using a metric ruler by 2 independent observers; Wilcoxon signed-rank test (α = 0.05) compared the 2 techniques. We operationally defined ≥5 mm as a clinically meaningful threshold.

Median lateralization was 5.0 mm (range 3.0-8.0) for MIS and 7.5 mm (range 4.0-9.5) for open. The Hodges-Lehmann median difference was 2.41 mm (95% CI: 1.25-4.00 mm), with no statistically significant difference detectable with the numbers available between techniques (Z = -1.47, P = .14). Using a clinically relevant ≥5 mm threshold, 4 of 8 MIS specimens fell below this level compared with 2 of 8 open specimens.

Both open and MIS LDCO were associated with similar lateral translation of the calcaneal tuberosity, with no significant difference detectable with the numbers available, though MIS was less consistent in reaching ≥5 mm of lateralization. Either approach may be used for mild-to-moderate hindfoot varus, with technique selection guided by soft tissue and infection risk considerations.

For mild to moderate hindfoot varus correction, MIS LDCO provides deformity correction comparable to the open approach while potentially reducing soft tissue morbidity. Surgical approach selection should consider patient-specific risk factors.