Opening Wedge Proximal Metatarsal Osteotomy

 - See: Hallux Valgus
- for mod hallux valgus in younger pts (HVA < 30 & IMA < 13-15 deg); 
- usually no pin or screw fixation is required; 
- no shortening of metatarsal will occur; 
- if a Silver Procedure is being performed, concomitantly, the excised medial eminence can be fashioned into a trapezoidal bone graft; 
- Disadvantages of Opening Wedge: 
- lengthens metatarsal, requires bone graft & can cause tightness of soft tissues, instability, & dorsiflexion of 1st metatarsal; 
- has potential for creating instability at osteotomy site; 
- Technique: 
- trace out the foot on the surgical glove paper;  
- a standard approach is is made to the medial side of the foot, w/ the incision extending from the base of the proximal phalanx to the the metatarsal cuneiform joint; 
- be aware of the dorsal cutaneous nerves, and be careful w/ placement of self retaining retractors; 
- incise thru the joint capsule (either straight or w/ a V flap) and take care not to injure the joint cartilage; 
- elevate the joint capsule and the attached periosteum in both dorsal and plantar direction; 
- perform the Silver Procedure, and fashion the excised medial eminence into a slightly trapezoidal wedge; 
- use a needle to identify the metatarsal cuneiform joint; 
- insert Homan metacarpal retractors on both the dorsal and plantar sides of the metacapals to protect the soft tissues during the osteotomy; 
- perform a straight lateral wedge osteotomy into the proximal osteotomy about 1 cm distal to the joint; 
- be careful, not to injure the periosteum on the far (lateral) side of the osteotomy (just as in an HTO), since a green stick effect is the desired goal; 
- if necessary a sharp osteotome can be used to complete the osteotomy, and to help pry open the medial side of the osteotomy; 
- wedge the bone graft into the osteotomy, a small bone tamp may be used to impact the graft flush against the metatarsal surface; 
- it is essential that metatarsal is not dorsiflexed as a result of the bone graft, hence the thicker side of the trapezoidal wedge should be inserted onto the dorsal side; 
- typically, the graft will seat tightly into the osteotomy, and hence there will be no need for pin or screw fixation; 
- determine the amount of correction of the hallux valgus; 
- because the osteotomy will medialize the MTP joint, the adductor hallucis will be relaxed and the abductor hallucis is stretched which would tend to medialize the great toe, hence further correcting the deformity




Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Friday, June 1, 2012 1:35 pm