Congenital hallux varus had been a well-described condition for many years before acquired hallux varus as a condition arising from bunion correction was not described until 1935. In that year, McBride discussed this potential problem when describing this as a potential problem from his described technique, identifying possible mechanisms to prevent the disorder from occurring. Authors such as Joplin and Kelikian echoed the concept in the early 1960's, spawning a series of corrective procedures. Miller brought this to common practice in 1975, describing the tendon imbalance seen across the precarious 1^st MTP joint.

The first metatarsophalangeal joint moves in the sagittal plane, dorsiflexion and plantarflexion only. Four intrinsic muscles stabilize the digit, with the abductor and adductor hallucis taking the lion share of this function. The abductor tendon actually functions primarily as a plantarflexor of the first metatarsophalangeal joint 83% of the time (Thompson) due to its primary plantar location. This fact, in combination with the pronation generally seen in severe bunion deformities, contributes to acquired hallux varus following bunion correction. Besides the obvious cause of over-correction of the metatarsal osteotomy creating hallux varus, imbalance of the tendon complex post-operatively can create an equally catastrophic circumstance. Hawkins demonstrated that severing the adductor tendon complex (the conjoined tendon) will not product hallux varus when the hallux is not rotated. However, in more severe hallux valgus, pronation of the hallux may be proportional to the deformity of the hallux itself. This rotational deformity places the insertions of the abductor (and medial insertion of the flexor brevis) more plantarward and lateral, increasing the valgus deformity. If the entire conjoined tendon is sectioned and the internal rotation deformity corrected the insertion of the contracted abductor moves medially, pulling the toe into varus. If the center of the base of the proximal phalanx is brought beyond the mid-point of the first metatarsal head, the extensor hallucis longus will bowstring, pulling the great toe into varus while creating a hallux flexus deformity. Finally, if the lesser toes are in varus and not corrected, this deforming force will create hallux varus following bunion correction with a lateral release. The message is clear: not all patients require a lateral release, and, if done, should be done with caution.

Once present, correction can be difficult. Tendon transfers utilizing the extensor hallucis longus (Johnson) or extensor hallucis brevis (Myerson) only have beneficial effects in non-arthritic, mobile first metatarsophalangeal joints. In addition, if metatarsal deformity is not corrected, the deformity will recur. Thus, in many circumstances, arthrodesis of the first metatarsophalangeal joint becomes the treatment of choice, and is commensurate with a disappointed patient who underwent a primary bunion correction and was left with a fused great toe.

This lecture will explore the above mechanism and salvage situations, in hopes of eliminating this unwelcomed outcome from your practice.

Most of the controversy surrounding management of the adult acquired flatfoot deformity revolves around the correction of Stage 2 deformity. Stage 1 deformity, uncommonly corrected surgically, involves tenosynovitis with preservation of tendon length and absence of structural deformity. Attempts at tenosynovectomy in light of structural deformity leads to operative failure, found in 10% of Teasdall and Johnson's 1992 patient population. Thus, with tenosynovectomy rarely becoming an operative situation, Stage 2 deformity becomes the mainstay of operative treatment of the adult flatfoot. Stage 2 deformity patients present with swelling medially, the inability to do a single heel raise, with a passively correctable subtalar joint. The tendon is functionally torn. In recent years, authors have subdivided Stage 2 deformity even further into A and B subcategories, where A involves less than 50% uncovering of the talonavicular joint, and B patients more than 50%. Recently, Anderson has added a C subtype, which may be applied to either A and B patients, in patients who have forefoot varus. Thus, Stage 2 patients suffer from pain that begins medially and progresses to the subfibular region over time. Most important, recognition of the continued sub classification in Stage 2 disease echoes the fact that this disorder is on a continuum, challenging the surgeon to recognize subtleties that, if unrecognized, lead to a poor patient outcome. The mainstay of treatment in Stage 2 disease is the medial slide calcaneal osteotomy, which realigns the hindfoot axis reducing valgus, improves the medial arch, protects the FDL tendon transfer, and allows the Achilles tendon to become a strong inverter. Over shift of the calcaneus can compromise the outcome, as will a lack of recognition of the congenital subtleties such that a valgus hindfoot can have a varus orientation to the calcaneus, both leading to lateral overload. A pure medial slide of a calcaneus that has a varus orientation does not correct deformity, rather, it creates it. Thus, an axial calcaneal view must be studied carefully, for a varus orientation may be corrected via a closing wedge osteotomy commensurate with the medial shift of the tuberosity. As noted above, the flexor digitorum longus tendon transfer is the staple procedure to replace the damaged posterior tibial tendon. This transfer balances the eversion power of the peroneal tendons, works in phase with the former posterior tibial tendon in the stance phase of gait, and replaces a painful diseased posterior tibial tendon. However, over tensioning the transfer results in a tenodesis rather than a functional tendon transfer, the relative weakness of the FDL tendon (30% as strong as the PTT) creates difficulty with heel raise, and inappropriate transfer to distal tarsal bones may compromise the result by limiting torque from the transferred tendon. Preservation of the posterior tibial tendon in combination with the transferred FDL tendon remains a consideration without answer, though Rosenfeld (2005) suggests a substantial improvement in strength through PTT preservation. Failure of the above protocol for treating Stage 2 disease most often revolves around the insufficient corrective power of the tandem procedures in longstanding ruptures. According to Guyton (2001), only 50% of patients report a perception in deformity improvement following FDL/calcaneal osteotomy procedures, and only 4% report a significant improvement in pre-existing deformity. Sangeorzan (2001) found such patients could not achieve a painless plantigrade foot due to acquired ligament laxity (primarily the Spring Ligament). Sangeorzan applied Evans' pediatric procedure to adults without confirming the pathomechanics of correction. Some speculate the windlass effect on the plantar fascia creates correction (refuted by Horton, 1998, finding the plantar fascia is loosened by a lateral column lengthening), others believe tightening the peroneus longus through lateral column lengthening increases first ray plantarflexion, restoring the medial arch. Controversy also remains in answering Cooper's (1997) claim that lengthening through the calcaneus creates static increase in pressure about the calcaneocuboid joint (1.4mPa total) that may lead to an arthritic joint long term. Painful lateral overload following lateral column lengthening remains difficult problem to both prevent and correct. This last point leads to some focusing their efforts on restoration of the medial column. This group focuses on the “C” type deformity noted by Anderson, those with forefoot varus. It is known that the medial column is supported by the navicular, the cuneiforms, and the first, second, and third metatarsals. While a Cotton (opening wedge medial cuneiform) osteotomy, a first tarsometatarsal joint arthrodesis, or a metatarsal osteotomy has value, the surgeon must note that this only corrects the first ray. Complete correction of the medial column is best achieved through naviculocuneiform joint arthrodesis. Standing radiographs commonly reveal collapse at that level; however, surgeons are reticent to perform such fusions in light of the higher nonunion rate.

Deltoid ligament insufficiency has been shown to decrease tibiotalar contact area and increase peak pressures within the lateral ankle mortise. Sectioning of the deltoid ligament has been shown to decrease tibiotalar contact area by 43%. This detrimental effect may create an arthritic ankle joint if left unresolved. Reconstructive efforts thus far have been less than satisfactory. Pankovich and Shivaram described the deltoid ligament as having superficial and deep components based on insertion sites. The superficial layer originates from the anterior colliculus of the medial malleolus and inserts on the navicular, calcaneus and talus. The deep layer originates from the intercollicular groove and posterior colliculus and inserts on the talus. Boss and Hintermann noted that the most consistent and strongest bands of the deltoid were the tibiocalcaneal and posterior deep tibiotalar ligaments. Chronic deltoid ligament insufficiency may be seen in several disorders including trauma and sports injuries, posterior tibial tendon disorders, prior triple arthrodesis with valgus malunion, or total ankle arthroplasty with improper component positioning or pre-existing ligament laxity. The reconstruction of the deltoid ligament in these settings may be critical to the prevention of tibiotalar arthrosis or failure of ankle prostheses from edge loading and polyethylene wear.

The reconstructive technique we describe, under low torque, was able to restore eversion and external rotation stability to the talus, which was statistically similar to the native deltoid ligament. In addition, though we maximally tension this graft to give the most secure repair possible, we did not note any increased stiffness in the ankle joint through our measurement techniques. This unusual, positive secondary effect is different from that noted in studies of lateral ligament reconstruction, where ligament tensioning by all methods attempts to reproduce the native tension and not exceed it. All medial ankle ligament repairs of substance involve some type of tendon-weave (whether autograft or allograft) to achieve reconstruction. Our technique develops its strength not only from the anatomic orientation of the reconstructed ligament, but the strength of the components chosen to fix the tendon graft to the bone. The use of Endobuttons allows the entire graft to sit within the tunnels, without the potential violation of the graft ends achieved through techniques utilizing interference screw fixation. Tensioning the graft proximally through the tibia against a rigid distal construct allows greater tension to be placed on the graft at the deltoid ligament site itself than techniques which employ distal tensioning while holding the ankle into inversion. Finally, the use of a looped graft proximally secured with a post that may be moved even further proximally at the surgeon's discretion creates superior tension to achieve medial column rigidity in grossly unstable situations. Thus, given the critical importance of the deltoid ligament and the relative paucity of repair/reconstruction options available, we believe this novel approach will assist the clinician in anatomically reconstructing this challenging condition.

Deltoid ligament reconstruction technique using semitendinosis allograft, with superimposed line drawing demonstrating orientation of looped graft.

Arthrodesis of both the ankle and the hindfoot has been discussed in the literature since the early part of the last century. Techniques have been modified substantially since these early discussions, though complications remain a frustrating element in patient management. Early procedures relied on molded plaster casts to hold fixation in corrected positions. Successful outcomes were hampered by loss of reduction in these casts and subsequent malunions. In addition, motion within these casts lead to a high rate of nonunion between the opposed bony surfaces. The era of internal fixation allowed compression across arthrodesis sites, enhancing union but creating a host of technical errors leading to unsatisfying results.

Malunion is also seen in post-traumatic situations. In particular, non-operative management of calcaneus fracture (or other hindfoot fractures) leads to not only arthritis of the involved joint surfaces, but malunion complicating successful fusion. Fusion in-situ leads to a high level of patient dissatisfaction, leading surgeons to challenging deformity correction while trying to achieve successful arthrodesis in compromised joints.

This lecture will focus on two types of malunion, one iatrogenic, one acquired. Revision triple arthrodesis (iatrogenic) can range from simple to challenging. A variety of studies document patient dissatisfaction following correction via this technique, ranging from Graves and Mann (1993) where the highest dissatisfaction rate was in highest in valgus malunion, to Sangeorzan and Hansen (1993), who found a 9% failure rate, most with varus malunion. The precarious balance required to create a plantigrade foot via triple arthrodesis with pre-existing deformity leaves even the most skilled surgeon challenged. As such, this component of the lecture will focus on recognition and correction of malunion based on a structured algorithmic approach we first presented in 1997. This algorithm is based on recognition of the apex of the deformity, and creating osteotomies to achieve balance.

We reviewed 28 patients who returned for follow-up examination who received treatment through this algorithm and found a statistically significant improvement in pre- and postoperative AOFAS ankle/hindfoot score, from an average of 31 points preoperatively to 59 postoperatively (p<0.01). All patients united, and all stated they would undergo the revision procedure again. Comparisons of pre- and postoperative shoe wear modification demonstrated a statistically significant improvement (p=0.01). Preoperatively, 20 patients required restrictive devices such as ankle foot orthoses and orthopaedic shoes. Postoperatively, only 1 patient required such a restrictive device. In fact, 17 patients required no modifications to their shoe wear at all.

The second component to this lecture will assess acquired hindfoot deformity, from malunion created by calcaneus fractures. A 2005 JBJS study by Brauer, et.al. found operative management resulted in a lower rate of subtalar arthrodesis with a shorter time off work compared to non-operative management. Removing the expense of time off work still netted a $2800 savings for operative management over non-operative management. Sanders echoed these thoughts in a JBJS 2006 paper, suggesting patients with displaced intra-articular calcaneal fractures may benefit from acute operative treatment given the difficulty encountered in restoring the calcaneal height and the talo-calcaneal relationship in symptomatic calcaneal fracture malunion. Thus, with these challenges in mind, the goal of this component of the lecture is to introduce methods to achieve balance and union with calcaneus fracture malunion. Vertically oriented multiplanar calcaneal osteotomy may assist the surgeon in avoiding the higher non-union rate associated with bone-block arthrodesis procedures. In this vein, the challenges associated with bone block subtalar arthrodesis will be explored.