BIOSS. Inter-Operative BIOmechanical Surgical Splint. By: Nick Schlewitz Department of Biomedical Engineering Vanderbilt University Advisors: Dr. Paul King, Vanderbilt University; Dr. Edward Glaser, D.P.M. What is BIOSS?.
A bunion is calcium deposit which occurs at the head of the first metatarsal.
The extra calcium causes a separation of the first and second metatarsals. The big toe commonly crosses over the second toe if left untreated.
The greater the separation, the more severe the operation to correct it.
Many bunions are so severe that they require restructuring of the first metatarsal. This is called a closing wedge osteotomy.
Closing wedge osteotomies are major operations and carry severe complications, sometimes crippling the patient.
Before (left) and after (right) picture of a bunion that has been removed. (http://www.footdrhorsley.com/diary/bunionectomy.php?display=print)
The most common complication resulting from a closing wedge osteotomy is called Metatarsus Primus Elevatus (MPE).
MPE is best described as an elevation of the big toe. The toe becomes fixated in this position and becomes rigid or completely immobile.
MPE, the big toe is clearly raised as a result of a closing wedge osteotomy
This condition can be
crippling and/or lead
to future operations.
Surgical technique, which involves the precision of the cut in the bone.
Post-operative weight bearing
Patients are already told not to bear weight and there is no way to template the cut. However, MPE can be addressed during the healing stages, when the foot is bandaged, with a splint that holds the toe in the correct position and sustains its mobility. This is precisely what BIOSS is designed to do.Why MPE?How do we treat it?
BIOSS is designed to alleviate MPE by two mechanisms:
BIOSS prototype showing the arch support
BIOSS prototype emphasizing the CPM feature
Only current CPM for toe joint