BACKGROUND
Hallux varus is a post-operative complication which has been reported in 0-15% of all corrective bunion surgery.1,3,7 Splinting can be beneficial in early stages of the condition, however, as the deformity progresses, hallux varus becomes more difficult to correct. Various surgical procedures have been described to correct hallux varus.1,4,5 Most procedures will employ a medial soft tissue release with or without a corrective osteotomy. Various tendon transfers using the EHL, EHB, split tibialis anterior, and abductor hallucis brevis tendons have also been described in the literature. A novel approach to this deformity is presented. The procedure described consists of a release of the medial soft tissue structures followed by reconstruction of the lateral collateral ligament utilizing a biologic collagen implant (OrthADAPTT Bioimplant, Pegasus Biologics, Irvine, CA). This technique is an innovative approach to this difficult surgical correction.

MATERIALS AND METHODS
The procedure is performed in the supine position under IV sedation. An incision is made on the medial side of the foot extending proximally from the base of the great toe to the mid shaft of the first metatarsal. The initial skin incision is deepened and the medial capsular structures are identified. A capsulotomy is then performed and the abductor tendon is lengthened via Z-plasty. After complete capsulotomy on the medial, dorsal and plantar aspect of the joint, the hallux is then allowed to assume a more neutral position.

A 2x15cm sheet of OrthADAPTT Bioimplant is prepared according to the manufacturer directions (Image #1). A 1x5cm strip is removed from the sheet using a sharp scissor. Two hemostats are placed at both ends of the strip and are twisted to make a cable(Image #2). Two drill holes are then made in the first metatarsal and the base of the proximal phalanx parallel to each other from medial to lateral(Image #5). Keith needles are then passed through these parallel drill holes (Image #6). The OrthADAPTT cable is passed beneath the deep transverse metatarsal ligament (Image #7). The cable is then pulled through the parallel drill holes in the first metatarsal and the base of the proximal phalanx from lateral to medial (Image #8). The Cable is then secured medially to the periosteum while the great toe is held in the desired position. The capsule is re-approximated utilizing absorbable suture. Skin closure is obtained using absorbable sutures and adhesive strips(Image #9)

RESULTS
A 53 year old female presented for a second opinion following bunion surgery at another institution which had led to a hallux varus deformity (Images #3-4). The condition had progressively become worse and gave her chronic pain. She began having transfer pain to the lesser metatarsals and the lateral side of her foot, and was unable to wear shoes that were appropriate for her occupation. She underwent a hallux varus repair with ligament reconstruction utilizing OrthADAPTT Bioimplant 14 months after her original hallux valgus repair. This resulted in an improved position for her great toe with a satisfying cosmetic (Image #9) and radiographic(Image #10) result. She was able to return to shoes without discomfort and had maintained correction after 8 months of follow-up. Follow-up MRI demonstrated no inflammatory response to the implant and incorporation of graft material in the bone tunnel (Image #11).

DISCUSSION AND CONCLUSION
Lateral collateral ligament reconstruction has been shown to be a safe and effective method for correcting hallux varus deformity. Tourne et al. reported a series of 14 cases in which a Ligapro suture was used to reconstruct the lateral collateral ligament.6 To our knowledge, there is currently no literature describing the use of biological equivalents to correct hallux varus.

The OrthADAPTT Bioimplant is an FDA approved, decellularized, biologic scaffold that fortifies and promotes tissue ingrowth. It is intended for the reinforcement, repair and reconstruction of soft tissue in orthopedic procedures. Preclinical studies have shown that the OrthADAPT Bioimplant-FX integrates with host tissue by revascularizing and supporting the remodeling cascade to lay down new collagen and provides a reliable scaffold throughout the healing process.

We report our results with the use of OrthADAPTT Bioimplant for the correction of hallux varus with maintained alignment, incorporation of graft material, and good cosmesis for the patient.

BIBLIOGRAPHY
1. AS Banks, JA Ruch and SR Kalish, Surgical repair of hallux varus, J Am Podiatr Med Assoc 78 (1988), pp. 334-339
2. BG Donley, Acquired hallux varus, Foot Ankle Int 18 (1997), pp. 586-592.
3. LR Janis and Donick II, The etiology of hallux varus: a review, J Am Podiatry Assoc 65 (1975), pp. 233-237
4. Vanore, J. et al.Diagnosis and treatment of First Metatarsophalangeal Joint Disorders. Section 3: Hallux varus The Journal of Foot and Ankle Surgery Volume 42,
Issue 3, May-June 2003, Pages 137-142
5. Myerson MS, Komenda GA: Results of hallux varus correction using an extensor hallucis brevis tenodesis. Foot Ankle Int 1996 Jan; 17(1): 21-7
6. Tourne Y, Saragaglia D, Picard F: Iatrogenic hallux varus surgical procedure: a study of 14 cases. Foot Ankle Int 1995 Aug; 16(8): 457-63
7. Hawkins FB: Acquired hallux varus: cause, prevention and correction. Clin Orthop 1971 May; 76: 169-76

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