Using an instrumented hammer to predict the lateral hinge fracture in high tibial osteotomy: A cadaveric study

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Skeletal Biomechanics

Background:

• Open-wedge high tibial osteotomy is a common surgical procedure for varus knee osteoarthritis.
• Lateral hinge fractures are a frequent complication, often related to the surgeon's control over osteotome impaction.
• Accurate identification of bone density during surgery is crucial for preventing iatrogenic fractures.

Purpose of the Study:

• To evaluate the efficacy of an instrumented hammer in distinguishing between cortical and trabecular bone during osteotomy.
• To determine if the instrumented hammer can detect bone fracture events in real-time.
• To assess the potential of this technology in preventing lateral hinge fractures.

Main Methods:

• Seventeen human lower-limb specimens were used in a cadaveric study.
• An osteotome was impacted using an instrumented hammer, recording force signals.
• A custom algorithm analyzed signal variations (specifically, τ) to identify bone type and fracture.
• The algorithm's performance was compared against manual surgeon assessment.

Main Results:

• The instrumented hammer successfully differentiated between cortical and trabecular bone, with significantly lower τ values in cortical bone.
• The algorithm achieved high accuracy (71% medial, 81% lateral) in detecting the transition to trabecular bone.
• The study demonstrated the potential to prevent excessive impacts leading to hinge rupture.

Conclusions:

• An instrumented hammer can reliably detect bone type and fracture during osteotomy.
• This technology shows promise for reducing the incidence of lateral hinge fractures in high tibial osteotomies.
• Further clinical trials are warranted to validate these findings in a surgical setting.