CHAPTER I O HALLUX VARUS: Congenital vs. Acquired

Alfred J. Phillips, D.P.M.

The hallux is an extremely immediately postoperatively, or several months challenging, but rewarding deformity to treat. Both after the initial surgery. In a review of 1100 acquired and congenital forms of hallux varus McBride bunionectomies, Janis and Donick exist. Acquired hallux varus is secondary to over- reported the rate of acquired hallux varus to be correction of hallux valgus, and congenital hallux 1.6%. peinstein and Brown reported an occurrence varus is observed at birth. Comparing the etiology rate of L.10/o in a review of B7B hallux valgus and treatment of both forms gives a better under- procedures of different varieties. The majoriry of standing of the hallux varus deformity in general. these procedures were a McBride bunionectomy The comparison stresses the variety of the with a fibular sesamoidectomy. presentation. It helps to identify the specific Several factors can play a role in creating an deforming force of that particular hallux varus case. acquired hallux varus, including staking of the As is common with most complex deformities, no metatarsal head, excessive tightening of the medial single deformity is exactly the same as another. capsule, excessive plantar lateral release, adductor A greater understanding of the deformity will tendon transfer, fibular sesamoidectomy, improve the overall treatment of the deformity. In overcorrection of the intermetatarsal angle, over- this paper both the acquired and congenital forms correction of the PASA, and aggressive of deformity will be reviewed, through the use of postoperative bandaging. The lack of a sagittal clinically illustrated case histories. groove or the presence of a round metatarsal head are also important contributing factors. It is often a ETIOLOGY combination of these factors that creates the deformity. Acquired hallux varus is an uncommon Congenital hallux varus is less common then complication following the correction of hallux the acquired type and is best addressed in infancy. valgus (Fig. 1). The deformity can be noticed If the deformity is not addressed or is under- corrected, the soft tissue imbalance will create osseous changes that will maintain the deformity into adulthood (Fig. 2). Historically, congenital hallux vants has been classified into three types. The primary type involves a tight band of tissue which extends from the medial aspect of the base of the first metatarsal and inserts into the base of the proximal phalanx, pulling the to the midline. The tight band of tissue described in the early literature is probably the abductor halluces. The secondary type is associated with forefoot deformities (metatarsus adductus). The tertiary type is associated with severe skeletal abnormalities such as diastrophic dwarfism. Congenital hallux varus is not considered to be hereditary. The greatest deforming factor in congenital hallux varus is the pull of the abductor halluces into the base of the proximal phalanx. This is more critical and has more of a tendency to result in the Figure 1. Acquired hallux varus secondary to an development of hallux varus when the pull is aggressive base wedge osteotomy. CHAPTER 10 5l

soft tissue and osseous cor:rection. If the patient is older and significant afihrosis has developed, joint destructive procedures may be considered. In order to address each specific case and determine a surgical procedure it is necessary to carefully evaluate the deformity through pre- operative and intraoperative assessment.

PREOPERATTYE ASSESSMENT

A proper preoperative assessment is critical in identifying deforming forces which have helped to create the deformity as well as identify those that maintain the deformity. Patient age, activity level and length of time that the varus has been present are important. Clinical evaluation includes determining the amount of hallux adductus, flexibility or rigidity of the varus, the quality and quantity of the range of Figure 2. Untreated congenital hallux varus. Note motion of the first metatarsophalangeal joint, the negative PASA. presence of a flexion of the interpha- langeal joint (IPJ) and whether it is rigid or flexible. primarily medial. The insetion to the abductor It will also include determining if there are any halluces occurs at the medial aspect of the base of associated forefoot deformities such as digital the proximal phalanx 20o/o of the time. It inserts adductus. Soft tissue adaptation will have occurred. into the plantar medial aspect of the base B0% of The abductor halluces will have tightened and the time. bowing and shortening of the extensor halluxis longus (EHL) tendon will have developed. Muscle TREATMENT tendon imbalance of the hallux will have created a flexion contracture at the IPJ, which leads to a Treatment of acquired hallux varus depends on the cocked-up and dysfunctional hallux. degree of severity of the deformity, and whether Radiographic evaluation will help to identify the deformity is symptomatic. Asymptomatic hallux the following findings that can help to create varus is usually very flexible and not very severe. hallux varus: presence or absence of the fibular The tibial sesamoid is usually peaking but not sesamoid, peaking of the tibial sesamoid, afihrosis dislocating over the medial aspect of the metatarsal of the joint, staking of the metatarsal head, inter- head. These generally go untreated and are metatarsal angle, and PASA. The presence or monitored for an extended period of time. absence of the fibular sesamoid plays a role in Symptomatic hallux varus usually requires surgical acquired hallux varus. The absence of the fibular interyention, and can involve soft tissue releases sesamoid may make it difficult to obtain long-term and tendon transfers, soft tissue procedures and correction with soft tissue procedures only. Even if osseous correction, or joint destructive procedures. the tibial sesamoid is relocated back underneath Congenital hallux varus cases are usually the metatarsal head via soft tissue releases and treated in infancy with manipulation, casting, and transfers, the soft tissue attachments (flexor splinting. Cases which are resistant to conserwative halluces brevis) will be stronger on the medial side ffeatment are ffeated with abductor tendon releases and will tend to gain mechanical advantage. This and skin plasty techniques. Abductor halluces will cause a recurrence of the hallux varus. tenotomies are frequently performed with Heyman, Arthrosis of the joint needs to be identified to Herndon, and Strong procedures in correction determine whether a joint destructive procedure of a congenital hallux varus with concomitant will be required. A Keller, an implant arthroplasty, metatarsus adducn-rs. Congenital hallux va ns cases or an arthrodesis procedure are all viable options which go unffeated and are symptomatic will require when long-term arthrosis is present. 52 CHAPTER 10

It is important to evaluate the amount of the specific situation. Quite commonly distal afticular surface remaining on the metatarsal head, metatarsal head procedures will provide adequate to give an idea whether the sagittal groove is still correction. Joint destructive procedures are present. Obviously, the lesser the amount, the performed on elderly inactive patients, in the case more difficult it will be to reconstruct the joint so of severe joint instability, or in cases where an that the hallux will not slip off the side of the osseous procedure could not be successfully metatarsal head while dorsiflexing. performed. Over-correction of the IM angle is att uncommon cause of the acquired hallux varus. CASE HISTORIES However the presence of this will usually require a reverse osteotomy for correction. In untreated Case History #l congenital hallux vaftis cases, the author has noted A 39-year-old active female was seen with a chief a negative PASA. This would be created osseous by complaint of pain in the first metatarsophalangeal adaptation to the tight abductor halluces tendon. joint. She also related that pain occurred along the medial aspect of the left great toe when she wore INTRAOPERA TTVE ASSESSMENT shoes. The patient's history included a juvenile hallux that was surgically Inffaoperutive assessment is required to propedy corrected 25 years previously using a true McBride correct hallux varus. A systematic and complete and an opening wedge osteotomy of the first periarticular release of the joint is performed first. metatarsal. The patient recalled that her great toe This will include release and tagging of the turned inward immediately after the procedure, abductor halluces tendon, EHL lengthening, and and has become worse over the past several years. complete medial and lateral release. After soft The clinical examination revealed a non- tissue release is performed, the foot is placed in a reducible hallux varus deformity (Fig. 3.A). Crepitus loaded position. The surgeon will identify whether was noted on the medial aspect of the joint during the hallux still shifts into adductus. Then the hallux range of motion testing. The hallux was cocked up is placed through its range of motion and the with a flexible flexor contraction of the interpha- surgeon checks to see whether the hallux drifts into langeal joint. Radiographs revealed a staked first adductus as it dorsiflexes. If this occurs, osseous metatarsal head, a medial dislocation of the hallux, procedures will need to be performed. Specific medial peaking of the tibial sesamoid, and the osseous procedures are determined depending on absence of the fibular sesamoid (Fig. 3B). The

Figure 3A. Clinical appearance of case #1 Figure 38. Radiographic appearance of case -l CHAPTER 10 53 intermetatarsal angle was approximately 5 degrees. Conservative therapy had failed and the patient desired surgical correction. The goal of the procedure was to correct the deformity and maintain motion of the joint. The difficulty however with maintaining the motion was in preventing recurrence. \7ith the fibular sesamoid absent and the sagittal groove compromised from the staked metatarsal head, it was somewhat questionable whether the joint could be realistically reconstructed and the joint motion maintained over the long-term. It was determined that in order to reconstruct the joint, the joint would have to be realigned by an osteotomy of the first metatarsal Figure 5. "2" lengthening of the long extensor tenclon is peforrned head and the deforming forces negated by tendon balance techniques. If this could not be accomplished, an arthrodesis or an implant arthroplasty would be required. Obviously, these were not the desired procedures because of the young age and activity level of the patient. It was decided to attempt a distal osteotomy with tendon re-balancing first and perform a salvage procedure at a Tater date if needed. A dorso-medial approach was used. The abductor tendon was released and tagged for later transfer to the lateral capsule (Fig. ,i). A "2" length-

Figure 6A. Intraoperative vieu, of the metatarsal head. Note the degenerative changes at thc dorso-medial aspect.

Figure 4. Abductor tendon is detached from the base of the proximal phalanx and tagged for later transfer. ening of the long hallux extensor was performed (Fig. 5). Inspection of the joint revealed significant erosion of the dorsal medial aspect of the first metatarsal head, and the absence of a sagittal groove (Figs. 6A, 68). A reverse Austin osteotomy Figure 68, DeE;Cncrative changes are apparent at the dorso-medial was performed and temporarily fixated to aspect. translocate the first metatarsal head medially and correct the varus. Upon loading the forefoot, the 54 CHAPTER 10

hallux was rectus, but when dorsiflexing the hallux the varus deformity was apparent. This deformity was demonstrated by an intraoperative radiograph with the hallux dorsiflexed (Fig. 7). Note that the hallux is adducted and the tibial sesamoid is peaking medially. This was because the dorsai medial aspect of the first metatarsal head was absent as a result of the previous surgery. Another factor was that the joint cafiilage of the metatarsal and the proximal phalanx were not in alignment. It appeared that a high PASA angle in the previous surgery was not addressed.

Figure 8A. The wedge of bone resected from the plantar prorimal aspect of the Austin osteotomy.

Figure 88. Note the frontal plane correction secondary to wedge removal with the transverse plane correction of PASA. Figure 7. Intraoperative radiograph revealing temporary fixation after a reverse Austin osteotomy. This u-as used to identify the metatarsophalangeal joint in a over-corrected sesamoid position on hallur dorsiflerion. Note (Fig. that the sesamoid is sti1l peaking medially, and position to allow the capsular tissue to adapt that the hallux is still in a varus orientation when 10). The abductor tendon was rerouted laterally dorsiflexed. underneath the long extensor and sutured into the lateral joint capsule. The extensor tendon was In order to realign the joint cartilage, a wedge reapproximated at its lengthened position, and of bone with a medial base and a lateral apex was final wound closure was performed. resected from the plantar portion of the proximal The postoperative management consisted of segment (Figs. BA, BB). Removal of this wedge two weeks of non-weight bearing in a surgical realigned the joint but also caused a relative shoe. The wire was then removed, and weight- increase in the dorsal medial aspect of the first bearing in a surgical shoe was initiated. The patient metatarsal head. The hallux did not have as much was able to ambulate in sneakers in three-and-a- tendency to drift into varLls during dorsiflexion as half weeks. Consolidation of the osteotomy was demonstrated by the intraoperative radiograph noted at six weeks. The patient is currently one (Fig. 9). Note that the hallux is realigned in a year postoperative, and the correction has been rectus position and the tibial sesamoid is in a maintained (Figs. 11, 12). This case exemplifies the better position. Permanent fixation was then complexity of the acquired hallux varus deformity. inserted. A 0.062 inch K-wire was placed across the CHAPTER 10 55

Figure 9. Intraoperetive radiograph u'ith hallur Figure 10. Postop.rrative radiograph rcvc'.lls final dorsiflexion follou.ing rcl'ror.al of a s,edge tcr fixation rvith a 0.062 Kw-ire across tl're ioint, coffect PASA. Thc hal1ux alignment and tibial holclirrg it in an over correctcd position. sesamoid position har.e improvecl.

Figure 11. Radiographic .lppearance, one year Figure 72. Clinic:rl appearance, one year postopcfative. postoperative. 56 CHAPTER 10

Figure 1JA. Clinical appearance of case ii2. Figure 1JB. Preoperative radiograph of case *2

Case History #2 A thiffy-eight-year-o1d white male presented with a chief complaint of a painful left great toe. He injured the toe when running after his young son. The patient stated that both great had always pointed inward, but since the injury, the left great toe turned inward to a greater degree. Clinical examination revealed abnormally long halluces, and bilateral hallux adductus with the left being more significant than the right (Fig. i3A). No significant contraction was present at the inter- phalangeal joint. First metatarsophalangeal joint motion was decreased, but without crepitus. Standard radiographs showed an elongated first metatarsal, peaking of the tibial sesamoid, and a high negative PASA (Fig. 138). The goal of the procedure was to correct the hallux varus and increase first metatarsophalangeal motion. The primary deforming force was deemed elongated first metatarsal and the Figure 1,1. Abductor tendon is tagged for later to be the transfer to the lateral capsule. negative PASA. It was decided to perform a Green- \flatermann type osteotomy to shorten the metatarsal and correct the PASA. Soft tissue releases were performed (Fig 74). A Green-Watermann osteotomy was performed. The osteotomy was fixated with 3.5 cofiical screw (Figs. 15A, 158). It was noted that the only thing interfering with total reduction of the varus was lateral soft tissue hypertrophy of the great toe (Fig. 15). The hypertrophy was an adaptation of the CHAPTER 10 57

(ilA/f#

T-A'*-*,wns Ljn I

Figure 15A. Dorsal view of the Green-Y/atemann osteotomv. Note the /=------,- clinical negative PASA. L----<)h^ Hv

Figure 158. Illustration of osteotomy. Note medial aspect of plantar u'ing which is ercised.

Figure 16. Postoperative clinical view reveals Figure 17. A lateral wedge of skin is excised for better correction. lateral soft tissLle hypertrophy which prevents total reduction of var-us. CONCLUSION long-term varus position. A wedge of skin was excised from the laleral aspect of the hallux to Acquired and congenital hallux varus cases have a al1ow the hallux position to be rectus (Fig. 17), similar presentation but different etiology. Final radiographs revealed correction of the PASA, Therefore correction varies according to specific and a normal metatarsal parabola (Figs. 18A-18C). deforming forces which have been identified. The patient was partial weight-bearing for one week followed by a gradual increase to full weight- bearing. He was full weighrbearing in a sneaker in three weeks due to the stability of the osteotomy. First metatarsophalangeal motion has improved since the procedure. 58 CHAPTER 10

Figure 18A Postoperative t,icu. afier removal of leteral tissr:e neclge

Figure 18B. Postoperative racliograph, dorsai- plantar vietr'.

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