TECHNIQUE TIP: AN EASY WAY OF TENSIONING AND SECURING A TENDON TO BONE
January 1st, 2002
Mark S. Myerson, MD; Ilan Cohen, MD;and Jaimie Uribe, MD
INTRODUCTION
Tendon transfers to the foot are frequently performed as static tenodesis procedures or as dynamic corrections of flexible deformity. Common examples of tendon transfers include transfer of the posterior tibial tendon to the dorsum of the foot, the flexor hallucis longus to the calcaneus, and the flexor digitorum longus to the navicular. To maximize the function of the transferred tendon, the tendon must be transferred at the appropriate tension and firmly secured to the foot. The tendon can be attached to soft tissues or directly to bone. Tensioning and secure fixation of the tendon transfer are relatively easy to achieve in procedures where both ends of the bone tunnel are exposed and visualized, since the tendon can be sutured to the adjacent soft tissues both proximal and distal to the tunnel. This procedure, however, is more difficult when the tendon is transferred to a bone where only the entry into the bone tunnel is visible, as in a posterior tibial tendon transfer. Suturing the tendon to the adjacent periosteum and soft tissue is not reliably strong, nor does it permit appropriate tension to be applied. The alternative procedure of passing a suture through the distal soft tissue and anchoring it to a button on the plantar aspect of the foot also has its disadvantages. Potential complications include pressure skin sores, infection, and unsuccessful fixation. In view of these complications, a more effective method of securing tendon to bone is needed.
In general orthopaedic practice, two methods are currently used in tendon-to-bone fixation procedures where the distal tunnel is inaccessible. The first method uses an interference screw inserted from proximal to distal, such as in arthroscopic anterior cruciate ligament reconstruction.{9722} The second method uses a bone anchor, a technique used for reattachment of tendons in locations such as the rotator cuff in the shoulder,{8994} the proximal and distal biceps brachii tendons in the arm,{9715} and the flexor digitorum profundus{9716} and the extensor’s central slip{9717} in the hand. Bone anchors have also been used in foot and ankle surgery to secure the Achilles tendon to the calcaneus,{9718} the peroneus brevis to the base of the fifth metatarsal after avulsion fractures,{9718} the tibialis anterior to the cuboid,{9719} and the redundant posterior tibial tendon on completion of a Kidner procedure.{9720} A recent case report described the use of a bone anchor in the repair of a traumatic hallux varus caused by an avulsion detachment of the adductor hallucis tendon.{9721} The anchors in these cases, however, were not used in conjunction with a bone tunnel. We present a reliable and simple method for achieving a stable fixation, while maintaining proper tensioning of the tendon, by passing the tendon through a predrilled tunnel in the bone using a suture anchor to improve fixation. This method facilitates correct tensioning of the tendon during transfer and helps ensure bone-tendon healing.
SURGICAL TECHNIQUE
The tendon to be transferred is sharply detached from its insertion, and a 2-0 nonabsorbable suture is attached to its end in a cerclage fashion to facilitate later passage through a bone tunnel. A trephine of 6 to 8 mm in diameter is then used to create a tunnel in the bone, and the dowel of bone is preserved for later reinsertion. The size of the trephine is determined by the size of the tendon and the bone into which it is to be transferred. After the tunnel is created, a single suture anchor (OBL Inc., Phoenix, AZ) is inserted at a 60º oblique angle to the plane of the tunnel into the side wall. A 4-cm straight needle is then used to guide the tendon stump with its attached suture through the bone tunnel, and the suture is delivered through the skin onto the plantar aspect of the foot. The suture is pulled in a plantarward direction until the necessary tension on the tendon is attained (Fig. 1a, 1b, and 1c). Further tension may be applied to the tendon by drawing it further into the bone tunnel using a specific method of suture. The tendon is secured to the bone by passing one or more suture strands from the bone anchor through the tendon. This is performed in a manner similar to the criss-cross lacing of a shoelace, entering the tendon 1 cm proximal to the entrance of the tunnel. The suture is finally tied, and, as tension is applied to it, the tendon is advanced into the tunnel up to the level of the bone anchor with the bone anchor acting as a fulcrum (Fig. 2). The procedure is completed by reinserting the dowel plug into the tunnel to enhance fixation and then cutting the suture at the level of the skin, allowing it to retract into the soft tissues.
POSTOPERATIVE MANAGEMENT
This method of tendon fixation is both secure and reliable, and patients are permitted to bear weight once the sutures are removed at ten days. We use either a walker boot or cast for four weeks when range of motion exercises and rehabilitation commence.
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