Fascial Turn-Down Flap Repair of Chronic Achilles Tendon Rupture

Transcription

1 19 Fascial Turn-Down Flap Repair of Chronic Achilles Tendon Rupture S. Ghosh, P. Laing, and Nicola Maffulli Introduction Fascial turn-down flaps can be used for an anatomic repair of chronic Achilles tendon rupture. This technique allows one to strengthen the suture line and diminish the formation of adhesions between the sutured site and the skin. 1 5 Historical Perspective Christensen 1 and Gerhardt 2 separately described similar techniques. After suturing the tendon ends, they raised a distally based flap from the gastrocnemius aponeurosis and turned it over itself across the suture line and sutured it to the distal part of the Achilles tendon. Silfverskiold 6 twisted the gastrocnemius flap through 180 degrees before suturing it distally. This resulted in the smooth surface of the flap coming in contact with the skin, thereby decreasing the chance of adhesion between the flap itself and the overlying tissue. Toygar 7 described a technique for chronic ruptures, where it is difficult to regain continuity between the two ends. The gap is bridged by two flaps, raised from the two ends of the tendon, one from the medial side and the other from the lateral side. Weisbach 8 described another technique to address the same problem. Along with the gastrocnemius flap, he raised another flap from the distal stump of the Achilles tendon, and sutured these two flaps in order to bridge the gap. In this chapter we describe two of the most commonly used techniques using the principle of turn-down flaps: first one that was described by Christensen in 1931 and Gerhardt in 1937, followed by the technique described by Lindholm in Operative Technique (Central Flap) The patient is placed in prone position. Anesthesia should ensure maximal muscle relaxation. Make a linear/curvilinear medial incision (to minimize the risk of injuring the sural nerve) from the midcalf to the calcaneus, taking care not to cross the midline in the distal part, in order to avoid scarring the tendon (Fig. 19.1). Incise the deep fascia in the midline after freeing it from the skin, thus making sure that the fascial incision lies fully under the skin flap. The site of the Achilles tendon rupture and the proximal gastrocnemius muscle are thus exposed (Fig. 19.2). Debride the tendon stumps as necessary, excising any fibrous tissue that may have formed in between the torn edges (Fig. 19.3). Then appose the refreshed ends with a box type of mattress suture, if possible, using heavy absorbable sutures. Place the foot in as much plantarflexion as required for proper apposition. Next, raise a flap approximately cm broad and 7 8 cm long (depending on the gap to be bridged in case of neglected ruptures) from the middle of the proximal tendon and the gastrocnemius aponeurosis (Fig. 19.4), thus creating a central flap. Make sure that the flap is long enough to bridge the gap and it can be sutured securely to the distal tendon. Leave the flap attached for at 174

2 19. Fascial Turn-Down Flap Repair of Chronic Achilles Tendon Rupture 175 FIGURE 19.1 Medial skin incision. least 3 cm proximal to the rupture. Next, turn the central flap upside down on itself and suture it to the distal stump with interrupted sutures (Fig. 19.5). Close the defect in the proximal tendon and gastrocnemius muscle belly with interrupted sutures. Close the tendon sheath and the deep fascia, followed by skin closure. Apply a plaster cast with the foot in gravity equinus. Aftertreatment At two weeks remove the cast, check the wound, and remove the sutures. Apply another short leg cast, with the foot in gravity equinus, for two weeks. After four weeks from surgery, bring the foot gradually to the plantigrade position over the next two weeks by serial changes of cast. The FIGURE 19.2 Tendon sheath exposed and fibrous tissue (which is bridging the defect) visualized.

3 176 S. Ghosh et al. FIGURE 19.3 Refreshed tendon ends after adequate excision of fibrous tissue. FIGURE 19.4 A central flap raised from the proximal tendon and gastrocnemius muscle. FIGURE 19.5 The central flap is turned down on itself to bridge the gap.

4 19. Fascial Turn-Down Flap Repair of Chronic Achilles Tendon Rupture 177 patient can gradually resume walking with partial weight bearing on crutches during a two-week period. At six to eight weeks, apply a short leg walking cast with the foot in the plantigrade position, and allow full weight bearing. Alternatively, use a removable brace allowing only plantarflexion. Begin gentle active range-of-motion exercises and isometric ankle exercises. Toe raises, progressive resistance exercises, and proprioceptive exercises, in combination with a general strengthening program, constitute the third stage of rehabilitation. At 12 weeks, start using a reverse-90-degree ankle stop brace or similar device (if not already in use) and continue until a nearly full range of motion and strength 80% that of the opposite extremity has been obtained, usually within 6 months. In reliable, well-supervised patients with good tissue repair you may accelerate this program, with earlier use of dorsiflexion-stop orthoses and active range-of-motion exercises. Discussion This technique is easy and simple to carry out. However, there is a risk of adhesion as the raw inner surface of the flap comes in contact with the subcutaneous tissue. This can be overcome by the modification proposed by Silfverskiold and discussed earlier. Lindholm noted avascular necrosis of the turned-down flap, and proposed his technique to avoid a possible injury to the vascularity of the flap. Operative Technique (Medial and Lateral Flaps) The initial steps, until the tendon is exposed, are the same as described above. The Achilles tendon rupture and lower part of the gastrocnemius muscle bellies are thus exposed (Fig. 19.3). Next, raise a flap approximately 1.0 cm broad and 7 8 cm long (depending on the gap to be bridged in chronic ruptures) from either side of the proximal tendon and the gastrocnemius aponeurosis about cm from the midline (Fig. 19.6). Leave these flaps attached at a point 3 4 cm proximal to the tendon suture. Try to use the superficial layer of the aponeurosis only, though at times this is difficult. However, the detachment of the superficial layer is easier if you make the longitudinal incisions first, and then undermine the flap, before dividing it proximally. After creating the flaps, twist them 180 degrees backward on themselves so that the smooth external surface lies next to the subcutaneous surface as you turn it distally over the rupture. Close the FIGURE 19.6 The two flaps are raised from the proximal end.

5 178 S. Ghosh et al. FIGURE 19.7 The flaps are turned down on themselves through 180 to reach the distal end and the proximal defects are sutured. proximal defect in the gastrocnemius aponeurosis with interrupted sutures (Fig. 19.7). Suture the flaps to each other in the midline and to the distal stump of the tendon using interrupted sutures (Figs and 19. 9). Close the tendon sheath and the deep fascia carefully (Fig ). Appose the subcutaneous tissues together and close the skin wound. After suturing the stumps of the Achilles tendon, gradually reduce the plantarflexion of the foot during the rest of the operation, by careful, continuous pressure against the sole of the foot. This ensures the tendon is progressively stretched, so that at the end of surgery the foot can be placed with only 5 10 degrees of plantarflexion. Apply a plaster cast with the foot in gravity equinus. FIGURE 19.8 The flaps are sutured to each other.

6 19. Fascial Turn-Down Flap Repair of Chronic Achilles Tendon Rupture 179 FIGURE 19.9 The combined flap is sutured to the distal stump. Aftertreatment This is the same as in the previous technique. Discussion Lindholm published this technique with results on 20 patients. He described better cosmetic results and lack of adhesion, while maintaining good functional outcome. 3 He described one patient with superficial infection of the wound, one with re-rupture, and one with a mild degree of skin fixity. Lindholm primarily described his technique only for acute ruptures and did not recommend its use in chronic ruptures, as he believed that a free gliding surface forms against the subcutaneous tissue in old ruptures and plastic procedures in these cases greatly impede suture of the skin. However, we use it in cases of neglected ruptures only. 5 The rationale behind fashioning two flaps instead of one central flap, as described by Silfverskiold, was to preserve vascularity of the tendon, which is mostly centrally distributed, thus preventing necrosis of the flaps. 3 FIGURE The paratenon is closed over the tendon.