Ahmedabad Bolt, Bicortical Bolt

1. Ahmedabad bolt is an assembly of 2 bolts. The small female bolt is hollow and internal threading receives male threads of the big bolt. The male big bolt is cannulated (allow guide wire) and threads that match with the small female bolt. male – female threads engage each other blindly(within the bone) and compress the fracture fragments together.

2. Under dynamic loading, the threads of conventional cortical/cancellous screws transfer shear force to the surrounding bone. Research suggests that bone is relatively weaker in shear force compared to tension, as stated by Norman et al. This shear force has the potential to be a significant contributing factor to the failure of cortical/Cancellous screws in bone.

3. BCB holding power does not depend on thread/bone interface (like cortical/ cancellous screw), rather it creates tension in BCB assembly and compression at screw head / cortical bone interface. Male female Machined thread engagement of big – small bolt has more superior holding power.

It has been proven in mechanical testing of the Breaking strength of a Bicortical Bolt in 3 part shear fracture model is 288 kg.

Ahmedabad bolt strength test in proximal tibia bicondylar fracture Model.

Ahmedabad bolt breaking strength test in proximal tibia bicondylar fracture Model. Load on medial and lateral columns

Surgical Technique

Ahmedabad Bolt, Bicortical Bolt, Guide wire insertion and measurement.

Ahmedabad Bolt invitro surgery in proximal tibia bone model.