The Reverdin style osteotomies are considered in patients with mild to low-moderate IM angle deformity (12–15°) and a subluxed MTP joint [9]. For the purpose of this text, we will define a Reverdin style osteotomy as any procedure of the distal metatarsal, which serves to correct an abnormal proximal articular set angle (PASA). A mild sagittal plane deformity can also be treated with Reverdin style osteotomies; however, correction may not be as dramatic as with other procedures. Adequate joint space with pain-free range of motion is required for improvement of functional outcomes utilizing this technique. Moreover, despite the inherently stable nature of the Reverdin osteotomy, adequate bone stock with the capacity to heal is also important.

The Reverdin procedure, first described in 1881, depicts a trapezoidal osteotomy made in the metaphyseal region of the first metatarsal head [10]. This medially based wedge, made at the level of the sesamoids, acts to adduct the capital fragment and realign the proximal articular cartilage. Hinging the distal articular fragment effectively corrects an abnormal proximal articular set angle (PASA) and realigns the hallux from its valgus orientation via reverse buckling [11] (Fig. 9.2). Several variations have been made to the Reverdin technique with distinct differences in anatomic location and orientation of osteotomies. With the addition of angulation to the osteotomy and plantar-based wedge resection, the Reverdin can produce both IM correction and plantar flexion. The osteotomy is positioned with the distal cut parallel to the articular cartilage and the proximal cut perpendicular to the long axis of the first metatarsal. Maintaining the lateral cortex will provide added stability.

Modifications to the osteotomy have produced multi-correctional capabilities (Reverdin-Green, Reverdin-Laird, and Reverdin-Todd). In 1977, Green described a modification that avoids possible damage to the dorsal articular surface of the sesamoid groove (Fig. 9.3) [12]. In 1988, Laird described a transcortical osteotomy, which penetrated the lateral cortex of the metatarsal head, allowing transposition of the capital fragment with relative reduction of the intermetatarsal angle (Fig. 9.4) [13]. Today, Reverdin style procedures are seldom performed in isolation and are usually a component part of HAV reconstruction. Lombardi et al. recommend the use of Reverdin procedures with basal or Lapidus type procedures as a method to address abnormal PASA [14]. Isolated Reverdin procedures have been largely replaced by aggressive soft tissue reconstruction or more aggressive osteotomies of the first ray; however, the recent emergence of percutaneous Reverdin procedures has continued to make this a relevant topic within the foot and ankle literature [15]. Although these multiplanar modifications have been described and have appeal, the exact degree of deformity correction in each plane may indeed be minimal. Solid evidence regarding the mechanical and functional outcomes is not available.

The Mitchell style osteotomies (Fig. 9.5) are considered in patients with mild to low-moderate IM angle deformity (12–15°). For the purpose of this text, we will define a Mitchell style osteotomy as any procedure of the distal metatarsal, which serves to correct an abnormal IM angle while attempting to reestablish normal load sharing to the forefoot [16]. Mild sagittal plane deformity can also be treated with Mitchell style osteotomies; however, correction may not be as dramatic as with other procedures. Adequate joint space with pain-free range of motion is required for improvement of functional outcomes utilizing this technique. Additionally, adequate bone stock with the capacity to heal is also important.

First defined in the literature by Hawkins et al. in 1945, this osteotomy describes a step-cut through the neck of the metatarsal used to reduce the intermetatarsal angle [16]. It was not until 1985 that Mitchell modified this technique to allow for the addition of plantar flexion to the capital fragment. This was achieved by the removal of a plantar-based wedge from the step-cut (Fig. 9.6). This osseous “wedge” removal often results in an excessively short first metatarsal. Merkel et al. performed a retrospective analysis of patients who underwent Mitchell osteotomies and found that 86% of patients were satisfied despite significant metatarsal shortening of greater than 5 mm [17]. The initial aim of the Mitchell modification was to reduce the incidence of transfer metatarsalgia seen in other IM corrective procedures. Transfer metatarsalgia is a potential concern with any osteotomy that may reduce metatarsal length; however, the subtle plantar flexion of the capital fragment has been suggested to offload the adjacent metatarsal heads. Nevertheless , a study by Heerspink et al. showed no significant reduction in transfer metatarsalgia when compared to Chevron osteotomy and found a significant shortening in first metatarsal length [18]. Furthermore, Shapiro and Heller noted transfer metatarsalgia in nearly 33% of patients who underwent a Mitchell procedure [19]. In their series, they found that individuals with a metatarsal 4–5 mm shorter than their second metatarsal were at increased risk for developing transfer metatarsalgia. The inherent instability of this osteotomy makes it necessary to consider non-weight bearing and even casting to prevent displacement. This factor along with the potential for shortening and lateral overload has made this procedure less popular within the foot and ankle community.

Austin, Leventon, and Coreless first described the Chevron osteotomy, also referred to as an “Austin procedure,” in 1962 [20]. Their technique describes a V-shaped osteotomy with the apex distal, within the metaphysis of the metatarsal head, used for the sole purpose of IM correction. This transcortical osteotomy utilizes a 60° horizontally directed V-shaped cut for lateral displacement of the capital fragment. The authors described the inherent stability of the Chevron osteotomy as a major advantage. It requires no fixation and allows for early weight bearing without casting. For added versatility, several modifications have been introduced which have improved fixation capabilities and stability. Modifications of the Austin have allowed for correction of PASA, plantar flexion of the hallux, and shortening or lengthening of the metatarsal. When multiple deformities are corrected within the same plane, the osteotomy is termed a bicorrectional Austin. In contrast, when deformity is corrected in multiple planes (transverse, sagittal), the osteotomy is called a biplane Austin. As with the other osteotomies described, the overall amount of accessory plane correction may or may not be robust. There are no current modifications to the Austin that address frontal plane deformity.

Subjective criteria for DMO include progressive pain confined to the medial bump, pain predominately when wearing shoes, and recent progression in the deformity. The patient may demonstrate neuralgia to the first dorsal digital nerve and its distributions. The authors will also consider DMO in patients that may objectively require a more proximal procedure for ideal intermetatarsal correction, but cannot tolerate non-weight bearing. Some surgeons consider DMO a reasonable option in those patients that cannot afford the extended convalescence associated with more proximal procedures. It must be noted that overall corrective result may not be equivalent to alternative procedures depending on the degree and configuration of the deformity.

Objective criteria for selection of DMO include a moderate deformity, pain-free first MTP range of motion, and a reducible deformity. The authors prefer DMO in patients with a stable forefoot where the first ray is stable without clinical signs of lateral forefoot overload (tender second MTP joint, hyperkeratosis plantar to the lesser metatarsal heads, global hammertoe deformities, etc.). Additionally, we prefer DMO when there is no significant evidence of hind foot pathology (equinus, flatfoot deformity, etc.) that might result in recurrence. These patients are better managed with more proximal procedures that might be more durable in the presence of hind foot pathology. Otherwise, one may consider addressing hind foot pathology concomitantly with a DMO in this situation. Additionally, as noted above this osteotomy does not provide for frontal plane axial correction which should be assessed preoperatively.

Preoperative radiographs are essential in planning a distal metatarsal procedure. Traditionally, DMO has been recommended for mild to moderate intermetatarsal angle (12–15°) with a deviated to subluxed metatarsal-phalangeal joint (HAA < 30). First intermetatarsal angles of 12–15° demonstrate good patient satisfaction and less reoccurrence. The author’s primary radiographic parameter when considering DMO is first metatarsal head width. Metatarsal head width will be the limiting factor in the amount of translation of the capital fragment and the degree of correction obtained with a DMO. Patients with relatively wide metatarsal heads will have the capacity for greater correction, regardless of the IM angle. The opposite is true for thin metatarsal heads, where excess lateral displacement of the capital fragment can result in an unstable osteotomy.