Sunday, 25 August 2019

HTO Plate for opening wedge osteotomies

High tibial osteotomy (HTO) is an effective and established method in treating osteoarthritis of the medial compartment of the knee. The HTO system consists of plates, screws and spacer blocks. A typical construct is made up of a plate, 4 screws and a spacer block and locking screw. The plate has an anatomical bend in the proximal portion of 10°. The plate has two screw holes distally and two adjacent screw holes proximally. The plate holes for the screws have a locking thread in them to ensure locking of the bone screws after insertion. The locking threads are angled to better place bone screws in bone stock. The proximal holes angle the screws divergently in the medial-lateral direction. The distal screw holes taper the screws distally. The plate features a central elongated channel that accepts a locking screw that connects the spacer block to the plate. The elongated slot allows for better positioning of the spacer block.
1- Titanium alloy HTO plate (Ti6Al4V) with ISO 5832-3, is available in one size (25×50 mm).
It is used with:
2- HTO cage: Ti6Al4V HTO cage (ISO5832-3) with various sizes (10, 12, 14, 16 mm).
3- Block screw: Ti6Al4V Block screw with ISO 5832-3.
4- Cancellous locking screw: Ti6Al4V Cancellous locking screw with ISO 5832-3 with ranges length from 34 to 78 mm.
5- Cortical locking screw: Ti6Al4V Cortical locking screw with ISO 5832-3 with ranges length from 22 to 55 mm.

Indications
- Young, active patient (<50 years) in whom an arthroplasty would fail due to excessive wear.
- Uni-compartmental arthritis with varus deformity of the leg axis.
- Varus deformity < 10◦ with stable ligaments.
- Up to 65 years of age, depending on activity level.
- Minimum ROM 0-120◦.
- Preferably not significantly overweight.
- Extension deficits must be taken into account and compensated for in the osteotomy planning.
- Correction up to 10◦.

Standard Test
ASTM F 382
Standard Specification and Test Method for Metallic Bone Plates.