Pertinent Pearls On Fifth Metatarsal Osteotomies
Which osteotomy offers the most advantages for treating a tailor’s bunion? Offering insights from their experience as well as a thorough review of the literature, these authors offer a closer look at options ranging from distal metatarsal osteotomies and the lateral exostectomy to transverse and oblique osteotomies.
The bunionette, or tailor’s bunion, is a deformity of the lateral or dorsolateral aspect of the fifth metatarsal. It is often a painful condition that shoe wear typically exacerbates. Retrospective studies have shown this condition is three to 10 times more common in women than men and arises predominantly in one’s 30s and 40s.1 Although authors have yet to agree to a single etiology, researchers have offered numerous theories in the literature.
Potential congenital etiologies identified in the literature have included: incomplete development of the transverse metatarsal ligament; the presence of a supernumerary bone lateral to the fourth metatarsal head; and the presence of an enlarged metatarsal head/condyles.2-5
Additionally, authors have cited aberrant biomechanical forces as a primary etiology. Hicks noted that excessive abduction of the fifth metatarsal would be irritating to the fifth metatarsal in shoes.6 Root identified many biomechanical abnormalities that could potentially lead to the formation of a tailor’s bunion. These abnormalities included abnormal subtalar joint pronation, uncompensated forefoot and rearfoot varus, and a plantarflexed position of the fifth ray.7
Structural and positional abnormalities including prominent lateral condyles of the fifth metatarsal head, and/or angular deformities of the fourth and fifth metatarsals also may contribute to this deformity. Fallat and Buckholtz identified several entities that could be associated with the presence of a tailor’s bunion. These entities include an increased intermetatarsal angle between the fourth and fifth metatarsal heads, an increased lateral deviation angle, lateral rotation of the plantar lateral condyle, a large dumbbell-shaped fifth metatarsal head, arthritic changes with bony exostosis at the fifth metatarsophalangeal joint, and any combination of the aforementioned conditions.8,9
The clinical presentation will typically reveal a painful and prominent metatarsal head with a subsequent corresponding hyperkeratotic skin lesion. This is often visible in the presence of erythema and may include an adventitious bursa.9 The fifth digit may exhibit an adductovarus position with or without corresponding skin lesions including both heloma molle formation and Lister’s corns.8-10
Conservative management should include shoe gear modifications such as wider toe box shoes, orthotics and padding of areas of prominence. When appropriate, one should debride lesions and attempt corticosteroid injections for treatment of an inflamed bursa.9,10 Clinicians may also use oral anti-inflammatory medications and analgesics adjunctively.1 Although conservative therapy may provide short-term relief, surgical intervention is often needed.1,9,10
A Guide To Preoperative Considerations And Incision Placement
Ensure that the patient is in a supine position. Bear in mind that many patients will externally rotate the lower extremities once they receive anesthesia. This makes appropriate visualization of the surgical target difficult.1,10 To avoid this, it is best to place a sandbag under the ipsilateral buttock. Tilting or “airplaning” the operating table toward the opposite extremity will also aid in visualization.10
Hemostasis will also help with keeping the surgical field clear for identifying vital structures. One can achieve this with the use of a pneumatic ankle tourniquet or administration of a local anesthetic agent with epinephrine (1:100,000).1,9,10