Minimally Invasive Operative Treatment of Bunionette Deformity with Percutaneous Distal Metatarsal Osteotomy



Minimally Invasive Operative Treatment of Bunionette Deformity with Percutaneous Distal Metatarsal Osteotomy


Jin Woo Lee

Woo Jin Choi





PATIENT POSITIONING

The patient is placed in supine position on a radiolucent operating table (Fig. 24-1). The foot is kept internally rotated with a small sandbag under the ipsilateral hip. The operation is usually performed using regional anesthesia and a tourniquet is used. Skin preparation and draping is performed with standard technique. Portable C-arm image intensifier television fluoroscopy is necessary to identify the correction of deformity and the pin position.


SURGICAL APPROACHES

A lateral incision of 1 cm is made just proximal to the lateral eminence of the fifth metatarsal head through the skin and subcutaneous tissue, down to bone. The soft tissue is separated dorsally and plantarly, and held by two small retractors. The lateral wall of the metatarsal neck is now visualized (Fig. 24-2).


REDUCTION TECHNIQUES

The complete osteotomy usually is made using a small blade oscillating saw from lateral to medial side with the obliquity oriented from plantar proximal to dorsal distal with an angle of approximately 30 degrees (Fig. 24-3). The key points of the technique are the inclinations of the osteotomy in the medial-lateral and dorsal-plantar direction, the displacement of the head in the medial-lateral and dorsal-plantar direction, and the rotation of the metatarsal head according to the types of deformity.8 The plane of the osteotomy in the lateral to medial direction is perpendicular to the fourth ray if the length of fifth metatarsal bone must be maintained. The osteotomy may be directed from distal to proximal up to 25 degrees, if shortening of fifth metatarsal bone is necessary in cases of mild arthritis. More rarely, if a lengthening of the fifth metatarsal bone is necessary the plane of the osteotomy is inclined in a proximal-distal direction approximately 15 degrees.

To control the dorsal translation of the metatarsal head with weight bearing the osteotomy is normally inclined about 30 degrees in distal-dorsal to proximal-plantar directions (Fig. 24-4). The adjustment of the lateral-medial position of the metatarsal head is performed by introducing the K-wire superficial with regard to the lateral eminence. The adjustment of the plantar-dorsal position of the metatarsal head is obtained introducing the K-wire in the upper or lower aspect, with regard to the long axis of the metatarsal head. If supination of the fifth metatarsal bone is present, the correction is obtained with derotation of the lesser toe to the neutral position.

Only gold members can continue reading. Log In or Register to continue

Jan 24, 2021 | Posted by in ORTHOPEDIC | Comments Off on Minimally Invasive Operative Treatment of Bunionette Deformity with Percutaneous Distal Metatarsal Osteotomy
Premium Wordpress Themes by UFO Themes