31.1 Introduction

A myriad of surgical procedures have been described to surgically correct hallux valgus. These can be broadly grouped by their location within the first metatarsal. With hallux abductovalgus (HAV) deformities, the center of rotation of angulation (CORA) is seen to be at the level of the first metatarsocuneiform joint (MCJ). That is, the apex of deformity. With this in mind, one can easily conceptualize that as the selected procedure more closely approximates this location, the more corrective influence can be obtained. In situations of HAV deformity with degenerative changes at the first metatarsophalangeal joint (MPJ), a first MPJ fusion is often the procedure of choice.

31.2 Preop

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  Positioning. The patient is placed supine on the surgical table with a bump under the ipsilateral hip to rotate the malleoli in a plane parallel to the floor. This position facilitates the assessment of deformity correction as well as optimizes the surgeon’s access to the entire first ray.

  
  
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  Tourniquet. Tourniquet use is based on surgeon preference, and when used, is best placed at the thigh level. Ankle tourniquets may also be used; however, this limits the amount of leg that is surgically prepped and can thus make manipulation of the leg for fluoroscopy more cumbersome. Additionally, an ankle tourniquet would prohibit an adjunctive gastrocnemius recession, which is often necessitated.

  
  
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  Anesthesia. Typically, general endotracheal anesthesia is the method of choice, but regional and even local blocks with moderate sedation have been described. A patient who is under regional or local anesthesia should not have a thigh tourniquet applied as this will cause significant pain.

31.3 Approach

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  The first MCJ is marked medial to the long extensor tendon and medial dorsal cutaneous nerve, and lateral to the tibialis anterior tendon (▶Fig. 31.1a).

  
  
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  The skin is sharply incised to the subcutaneous layer. The medial marginal vein or a branch thereof is sometimes encountered, which is mobilized and protected or ligated if necessary.

  
  
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  The long extensor tendon is visible in its sheath beneath the fascia. Medial to this, the remaining tissue can be incised to the level of bone with impunity (▶Fig. 31.1b).

  
  
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  Full thickness soft tissue flaps including periosteum are developed medial and lateral to the joint, and the long extensor is retracted laterally, revealing the joint (▶Fig. 31.1c).

  
  
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  The joint capsule is incised (▶Fig. 31.1d) and the collateral ligaments are sectioned; care is taken laterally within the first interspace to avoid insult to the deep plantar artery.

31.4 Joint Preparation

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  A Hinterman retractor is useful to gain access to the joint for preparation.

  
  
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  The authors prefer an “in-situ” approach to joint resection. In this way, the length of the first metatarsal is preserved. Additionally, corrective cuts within the metatarsal or cuneiform can result in undue shortening and have the potential for gross overcorrection.

  
  
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  The joint cartilage is currettaged to bleeding cancellous bone, no attempt to preserve the subchondral plate is made (▶Fig. 31.1e).

31.5 IM Correction

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  Attention must be paid to all three cardinal planes for appropriate deformity correction. This type of correction is only obtainable with a first MC fusion. ¹

  
  
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  A Kirschner wire (K-wire) is placed into the first metatarsal shaft from medial to lateral, plantar to dorsal (▶Fig. 31.2a). Rotating the medial end of the K-wire toward the dorsal foot will affect de-rotation of the metatarsal shaft (supinatory effect) (▶Fig. 31.2b). Appropriate joint mobilization is the key to allow this.

  
  
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  For sagittal plane correction, the great toe is dorsiflexed, which reciprocally plantar flexes the metatarsal into a functional position. Metatarsal elevatus is a common component of HAV.

  
  
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  Lastly, a clamp is placed with one tine around the medial first metatarsal head, and one tine around the lateral second metatarsal head through a percutaneous incision (▶Fig. 31.2c). The first metatarsal is made to be parallel to the second, avoiding a negative IM angle, which could cause an iatrogenic hallux varus.