Tibial slope modifying osteotomies

Chapter synopsis

This chapter focuses on proximal tibial osteotomies to correct sagittal tibial slope to address not only cruciate ligament (ACL or PCL) pathologies but also meniscal and cartilage deficiencies. Cruciate reconstructions have been shown to fail in patients with greater posterior tibial slope in the case of ACL reconstructed knees and in those with flat or decreased posterior tibial slope in PCL reconstructed knees. In revision settings, these osteotomies can be a powerful tool to ensure success.

Important points

• Consider posterior tibial slope as a risk factor for failure in all cruciate reconstructions

• Indications for pure sagittal plane slope changing osteotomies: Failed ACL reconstruction in a patient with posterior tibial slope greater than 12°, PCL reconstruction failures with flat (decreased) posterior tibial slope less than 6°.

• Indications for biplanar corrective osteotomies: Failed Cruciate reconstruction in the setting of varus/ valgus and increased or decreased posterior tibial slope (ACL or PCL respectively for sagittal plane deformity).

• Contraindications to slope changing osteotomies: Active infection, patient unable to comply with rehabilitation or weight bearing restrictions after surgery

• Assess the degree of correction for sagittal slope as well as any planned coronal correction prior to surgery because it will impact implant and technique selection, i.e. too large a correction in two planes requires a correction over a frame/external fixator

Clinical/surgical pearls

• Critically assess range of motion as well as collateral ligament deficiencies as recurvatum or flexion contractures can be improved or worsened depending on the slope adjustment.

• High-quality long leg alignment films and high-quality lateral knee radiographs with at least 15 cm of proximal tibia included for adequate surgical planning.

• Make all pure sagittal slope correction cuts under fluoroscopic visualization to ensure protection of the posterior hinge.

• A tibial tubercle osteotomy may be considered in an anterior closing wedge osteotomy when decreasing tibial slope to prevent patella alta.

• Additional fixation may be required in addition to staples to control the proximal articular segment (small fragment T-plates etc.)