How To Manage Postoperative Hallux Varus

Chances are, you have seen patients present to your office with pain after undergoing a bunion surgery, which you may or may not have performed. If you were the operating surgeon, it is easy enough to research the specific procedure that you performed. However, in many cases of hallux varus complications, the patients wind up in another surgeon’s office for reconstruction. Obtaining all the prior operative and post-op information will aid in tailoring the revisional surgery. With this in mind, let’s consider the following case. A 55-year-old female patient returns to the office for a follow-up visit four months after her bunion surgery. The patient is complaining of continued pain in the first metatarsophalangeal joint that occurs mainly with range of motion and ambulatory activities. The patient also expresses some concern about the position of the toe, stating it looks “too straight.” We sent her to get some new films and went back to check the op report, X-rays and post-op notes. The op report discussed a medial skin incision, a standard lateral release of the adductor tendon at the level of the joint as well as a lateral capsulotomy. For the osteotomy, we had performed a standard head procedure, using a long dorsal-arm chevron bunionectomy and fixation with two 2-0 mm screws. We had resected the medial overhang and smoothed the medial first metatarsal as per standard procedure. We also had performed a medial capsulorrhaphy with tightening of the medial capsule. Intraoperative fluoroscopy pictures in the chart revealed great positioning of the sesamoids under the first metatarsal head. They showed good correction of a moderate bunion deformity without overaggressive translocation of the capital fragment or medial resection. The intermetatarsal angle had been corrected from a 14 to an 8 or 9. The initial postoperative visits at one, two, four and six weeks were all uneventful with a normal postoperative course. The patient denied any history of trauma. She was attending some range of motion therapy with a licensed physical therapist specializing in foot and ankle care. She had shown good progress in terms of range of motion. She noted the pain was better but remained persistent. The patient has been in tennis shoes for about six weeks, but can not wear much else. Normally an active person, she has tried to increase her activity but is bothered by the pain. She now raises questions about the cosmetic appearance of the toe. The patient’s films confirm early onset of a hallux varus. The hallux abductus angle is approximately a negative 3 degrees with an IM of 8. The position of the capital fragment on the first metatarsal shaft is good with no visible osteotomy line and no signs of malrotation, collapse or overcorrection. The screws are intact without shifting or signs of loosening. On the DP radiograph, the tibial sesamoid has migrated medially a small amount from the previous films and is now peeking out medially. Emphasizing The Importance Of Informed Consent The patient wants to know what happened and where do we go from here. Informed consent is an important part of the preoperative work-up. We are careful to spend the extra time with patients detailing the procedure and outlining the potential complications with each specific procedure. Iatrogenic hallux varus is an uncommon complication that, according to the literature, occurs in 1 to 5 percent of cases. Since we had informed and educated the patient regarding the possibility of developing hallux varus along with other potential complications, she returned to our office for treatment and possible revision. A Guide To Key Treatment Considerations The literature offers many options for treating iatrogenic hallux varus. Conservative management includes strapping, taping and padding of the hallux in a corrected position. When employing conservative treatment, make sure the patient understands the corrective device needs to be in place all the time. Applying felt padding to the inside of the shoe is a good idea, but keep in mind that most people will be in those shoes for only a third of the day. This will not provide long-term correction. Surgical reconstruction of early hallux varus is directed at correcting the deforming force, but bear in mind that the same procedure will not work for every patient. For example, if the flexors have been destabilized due to a fibular sesamoidectomy, one needs to address this. If an over-corrective osteotomy was performed, consider a reverse osteotomy to increase the IM angle. This also may place the sesamoids in a better position under the metatarsal head. If excessive resection of the medial eminence had been performed, applying a bone graft to the medial first metatarsal has been described in the literature. Soft tissue balancing, in the absence of osseous deformity, should follow some basic principles. One should make a dorsal or dorsomedial incision even if a medial incision were made initially. The incision should extend longer distally and proximally to allow for easier tissue plane separation away from the scar tissue of the previous surgery. In a reconstructive case like this, you should avoid having less exposure than the initial surgeon had. Perform deep dissection medially and laterally into the interspace, separating the deep and superficial fascia, and defining the joint capsule. The tight medial capsule may need a capsular flap to allow for lengthening, but maintain coverage. Perform a complete capsulotomy and, if necessary, mobilize the sesamoid apparatus with a McGlamry elevator. Load the foot and evaluate the position. Even if the toe maintains an improved position at this time, it is important to perform adjunctive stabilization procedures as soft tissue release alone will not typically give a lasting corrective result. Several tendon transfer and/or lengthening procedures, including abductor hallucis, extensor hallucis longus and adductor hallucis, have been described in the literature. One would typically reserve joint destructive procedures, including implant arthroplasty, Keller arthroplasty and arthrodesis, for long-standing hallux varus presentations that have secondary arthritic degeneration of the first MTPJ. Pertinent Pearls On Successful Surgical Revision In this case, after reviewing the initial operation and examination of the patient and radiographs, we determined that the developing deformity was due to a combination of the following factors: a medial incision, medial capsulorrhaphy, lateral release and postoperative bandaging in a slightly overcorrected position. Regarding the medial incision, note that post-op scarring typically occurs along the line of the incision. Therefore, a medial incision typically will produce some additional scarring and stabilization along the medial aspect of the hallux and first MTPJ. In this case, it also could have been an additional contributing factor in the medial drift of the hallux. We advocate early surgical intervention due to the dynamic and usually progressive nature of iatrogenic hallux varus. In addition, if the hallux remains in a medial position for an extended period of time, joint degeneration will begin to occur and the lesser digits may also begin to drift medially. Once the condition of hallux varus becomes more chronic and longstanding, one should give more consideration to joint destructive procedures. Following a long dorsal incision and careful layer dissection, we performed a capsulotomy and released the tight medial structures with a V-Y medial capsular flap. We chose to perform a stabilizing tendon transfer with use of the extensor hallucis brevis. This tendon, the first slip of the extensor digitorum brevis muscle that inserts on the dorsal base of the proximal phalanx, dorsiflexes the proximal phalanx of the hallux. Leave the insertion intact and dissect the tendon proximally. Harvest the tendon at the myotendinous junction in order to help ensure good length for the transfer. Emphasize meticulous dissection in order to avoid iatrogenic compromise to the deep peroneal or medial dorsal cutaneous nerve as well as the terminal branches of the dorsalis pedis artery. Once the tendon is harvested proximally, pass the tendon deep to the deep transverse metatarsal ligament (DTML) to the lateral surface of the first metatarsal head. Once you have placed the hallux in a corrected position, perform a bio-tenodesis, placing the extensor hallucis brevis into the lateral head of the first metatarsal. We prefer to use Arthrex suture anchors in this case. A titanium corkscrew anchor available from Arthrex incorporates a cancellous thread with a very small core diameter. This maximizes the pull-out strength in cancellous or osteopenic bone. This anchor also doesn’t require any pre-drilling to facilitate a tenodesis site to the lateral first metatarsal head. After suture repair to the capsule and medial capsular flap, close the wound in standard procedure. Splint the hallux in this corrected position and consider the use of postoperative forefoot slipper casting to ensure that this position is maintained. Final Thoughts Iatrogenic hallux varus is a difficult entity to treat and usually requires surgical repair and reconstruction. It is important to identify the deforming force in order to correctly select your procedure and target the repair. The patient is usually frustrated with the complication and need for further surgery, so it’s important to spend extra time with the patient, whether you did the initial case or not. Patients appreciate honesty, not guarantees. Dr. Baravarian (shown at the right) is an Assistant Clinical Professor in the Department of Surgery/ Division of Podiatric Surgery of the UCLA School of Medicine. His e-mail address is bbaravarian@mednet.ucla.edu. Dr. Franson is Chief Resident at the VA Medical Center of Los Angeles.