[High tibial osteotomy--primary stability of several implants]

Area of Science:

• Orthopedic Surgery
• Biomechanics
• Surgical Implant Technology

Background:

• High tibial osteotomy is a long-standing surgical technique for treating varus knee.
• Recent advancements have introduced newer operative techniques for this procedure.
• In vitro assessment of primary stability for these techniques is essential.

Purpose of the Study:

• To evaluate and compare the primary stability of various surgical implants used in high tibial osteotomy.
• To determine the influence of implant design and surgical technique on osteotomy stability.
• To provide data guiding the selection of implants for optimal varus knee correction.

Main Methods:

• Testing of ten human cadaveric knee specimens (mean age 61 years).
• Evaluation of four implant types: tubular plate, Giebel's plate, bone staples, and external fixator.
• Application of shear and axial forces to the osteotomy site under controlled laboratory conditions.

Main Results:

• External fixators and bone staples demonstrated the highest primary stability.
• Giebel's plate and the one-third tubular plate exhibited lower stability.
• The integrity of the medial cortical bone was critical for achieving adequate primary stability.

Conclusions:

• External fixators and bone staples are superior in providing initial stability for high tibial osteotomy.
• Maintaining the medial cortical bone's integrity is paramount; additional medial fixation may be required if it's compromised.
• While results are comparable with correct implantation, the study's limitations include not accounting for soft tissue effects in vivo.