Proximal Metatarsal osteotomies are used for larger deformities, generally those with an intermetatarsal angle greater than 15°. These osteotomies usually are combined with a Distal Soft Tissue Release, which is necessary to correct metatarsophalangeal (MTP) sub-luxation with a Hallux Valgus Angle greater than 35°. Many types of osteotomies have been described. These include a medial opening wedge, a lateral closing wedge, proximal chevron, and a crescentic. Additional osteotomies include the Scarf, Ludloff, and Mao osteotomies. Presently, the proximal chevon and crescentic osteotomies are widely used.
In our study we used the proximal chevon osteotomy combined with Distal Soft Tissue Release and approximation of the 1st and 2nd metatarsus using a string to further decrease the intermetatarsal angle.
From January 2000 to June 2005 the basal chevon osteotomy was selected in 44 patients (37 female and seven male patients, ages 14 to 80, mean: 54.97 years) total of 49 feet with moderate metatarsus primus varus (IMA 13 to 20 degrees) and hallux valgus deformities (less than 50 degrees). The AOFAS Hallux Metatarsopha-langeal-Interphalangeal Scale and patient satisfaction were monitored prior to surgery, and postoperatively. Changes in the IMA and HV angle were measured in the conventional method and documented. All patients were treated in a Darco Post operative splint.
Results: Multiple complications were encountered. The most common is transfer metatarsalgia. This occurred in 10 patients (20%). Other complications include delayed union (4%), increase in the height of the first metatarsus (10%), floating toe (6%), superficial infection (15%), local parenthesis and early recurrence of deformity in 3%. 38 patients were available for follow-up. The hallux valgus angle improved significantly more than 20 degrees on average postoperatively. The intermeta-tarsal angle also improved significantly (more than 10 degrees on average) postoperatively. The position of the sesamoids was realigned to beneath the first metatarsal head and the metatarsal length remained essentially unchanged. The AOFAS score preoperatively was a mean of 75.64 with respect to pain, deformity, motion, disability, and cosmetic. The AOFAS score postoperatively was a mean of 94.55. The mean improvement was 18.91. About 95.45 percent (42/44) were satisfied and would recommend the surgery to a friend.
Conclusions: The basal chevron osteotomy combined with Distal Soft Tissue Release and realignment using a string is a technically demanding procedure and has multiple potential complications but provdes a reliable method with respect to stability, technical ease and satisfactory surgical outcome for correction of moderate and severe bunion deformity, both as a primary and revision procedure.
