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Achilles tendon reconstruction using the flexor digitorum longus
ACHILLES TENDON RECONSTRUCTION USING THE FLEXOR DIGITORUM LONGUS ROGER A. MANN, MD
Reconstruction of the Achilles tendon is presented using the flexor digitorum longus (FDL) tendon. The involved area of the Achilles tendon is resected. The remaining tendon is advanced either into the calcaneus if the distal portion has been resected or into the viable portion of the tendon. The FDL is harvested from the plantar aspect of the foot and is used as an intact musclotendinous unit to help re-establish the proper tension of the reconstructed Achilles tendon. KEY WORDS: Achilles tendon reconstruction
The underlying principle of reconstructing the Achilles tendon with the flexor digitorum longus (FDL) is to create an intact musculotendinous unit. By using a normal musculotendinous unit, a new resting length for the posterior calf muscles can be achieved, and the remainder of the Achilles tendon reconstruction can be developed around it. The cross-suturing of the reconstructed portion of the Achilles tendon to the intact musculotendinous structure allows the vascularity of the muscle mass of the tendon transfer to hopefully participate in the revascularization of the reconstructed Achilles tendon. When reconstructing the Achilles tendon, there are several technical problems that the surgeon must be aware of. The first and foremost problem is that the skin around the Achilles tendon and posterior calcaneus has a significant tendency to slough, particularly if previous scars are present. Therefore, it is imperative that all skin flaps are made full thickness and carried directly down to the tendon sheath of the Achilles tendon both distally and proximally. At times, w o u n d closure can also be a problem, because as the reconstructed tendon and transfer are pulled down under tension, tenting of the skin occurs. This can be partially overcome by placing the foot in maximum plantar flexion and using stitches that help keep the tension off of the skin edges.
TECHNIQUE The surgical approach for reconstruction of the Achilles tendon is divided into three parts. The first part is the surgical approach, which exposes the proximal and distal portion of the Achilles tendon; the second is obtaining the FDL from the plantar aspect of the foot; and the third is securing the tendon into the calcaneus.
in private practice, San Leandro, CA.
Address reprint requests to Roger A. Mann, MD, 237 Estudillo Ave, San Leandro, CA 94577. Copyright 9 1994 by W. B. Saunders Company 1048-6666/94/0403-0003505.00/0
138
The procedure is carried out with the patient in a prone position and a tourniquet around the thigh. The initial skin incision is made along the posteromedial aspect of the calf, starting at approximately the midportion of the leg and carried distally, almost bisecting the interval between the medial border of the gastrocnemius and posterior medial border of the tibia. As the incision is brought distally at about the midportion of the calcaneus, it is carried lateralward across the midline for about I cm. The incision is deepened to the sheath of the Achilles tendon proximally and distally. Care is taken not to traumatize the skin edges (Fig 1A). The pathological portion of the Achilles tendon is identified, and having opened the sheath proximally and distally, the two incisions are brought together to expose the abnormal tendon. The neurovascular bundle is located in the vicinity of the anteromedial aspect of the tendon and should be watched for. Having freed the tendon circumferentially, the portion of the tendon that needs to be reconstructed is identified. If the pathology is in the midsubstance of the tendon, that portion is excised, or if the pathology is in the area of the insertion of the tendon, that portion is excised. It is important that as much of the pathological tissue be excised as possible so that, hopefully, normal tendon will be healing together after the reconstruction is carried out. If the surgeon excises the midportion of the tendon well proximal to the insertion, then the central flap that is developed is brought down and sutured into the remaining portion of the tendon. If the portion that is resected is at the insertion of the tendon, then the advanced portion of the tendon needs to be brought d o w n and buried into the calcaneus to create a bony insertion for the tendon. The FDL tendon is now harvested by making an incision along the medial border of the foot, just along the superior margin of the abductor hallucis muscle. The muscle belly is reflected in a plantarward direction, the posterior tibial tendon is identified, and the next tendon plantar to this is the FDL. The tendon is carefully freed from its tendon sheath and traced distally, taking down the master knot of Henry. Some bleeding is often encountered in this area that requires cauterizing. In the
Operative Techniques in Orthopaedics, Vol 4, No 3 (July), 1994: pp 138-140
A
I
Fig 1. (A) The incision used to expose the Achilles tendon is shown. The medial foot incision allows for access to the FDL tendon. (B) Tenodesis of the FDL stump to the flexor hallucis Iongus. (Modified and reprinted with permission. 1'2) ACHILLES TENDON RECONSTRUCTION
Fig 2. (A) The FDL is pulled through the calcaneal drill hole. (B) Augmentation of the defect by spanning the gap with an advanced portion of Achilles tendon. (Modified and reprinted with permission. 1'2) 13g
midportion of the foot where the FDL and flexor hallucis longus cross one another, the tendon is severed. The distal portion of the FDL is sutured into the flexor hallucis longus if adequate cross-connections do not exist (Fig 1A and B). 3 The freed FDL tendon is now pulled into the proximal portion of the wound, and the foot incision is closed in a routine manner. A transverse drill hole is made in the calcaneus, and the FDL tendon is advanced through it and sutured back onto itself (Fig. 2A). As this is carried out, the ankle should be held in approximately 10~ to 15~ of plantar flexion, with the knee bent at a right angle. The tendon is then sutured onto itself to secure it. The central half of the Achilles tendon is now developed and brought distally to either bypass the gap in the tendon if it has been sectioned proximal to the insertion, or brought down into a hole made in the calcaneus if the Achilles tendon was excised at its insertion. As this portion of the procedure is carried out, enough tension must be placed on the reconstructed Achilles tendon so that some semblance of normal musculotendinous tension is restored to the Achilles tendon (Fig 2B). Once this has been carried out and the advanced portion of the Achilles tendon has been sutured to the substance of the Achilles tendon itself, the transferred FDL is cross-sutured to the Achilles tendon. Once this is achieved, the w o u n d is closed in layers over a drain with the subcutaneous layer being carefully closed so that the skin can be brought together under minimal tension. Although the ankle has been set in about 10~ to 15~ of equinus, it can be placed down into more equinus w h e n the w o u n d is closed to keep the tension off of the skin edges. The patient is placed into a snug compression dressing incorporating plaster splints.
140
POSTOPERATIVE CARE The postoperative m a n a g e m e n t includes a dressing change at about 10 days, and if the w o u n d is healed in a satisfactory manner, the ankle is placed into approximately 10~ of equinus. The patient is kept in this position for approximately 2 months, after which gentle range-of-motion exercises are begun, but the immobilization in a removable cast continues. The patient is permitted weight bearing after 3 months, and instructed to gently work on range-of-motion exercises using an elastic band. At 4 months, if the tendon seems to be fairly stable and there is minimal pain and thickening about it, activities are permitted without the cast. If there is still warmth and swelling about the tendon, unprotected weight bearing is not permitted until this subsides. As a general rule, patients are immobilized for 5 to 6 months, after which, if there is any doubt regarding the stability of the transfer and reconstructed area, the patient is placed into a polypropylene ankle/foot orthosis with an articulated ankle and permitted about 10~ of dorsiflexion.
REFERENCES 1. MannRA, HolmesGB, SealeKS, et al: Chronicrupture of the Achilles tendon: A new technique of repair. J BoneJoint Surg [Am] 73: 214-219, 1991 2. PlattnerP, Mann RA: Disorders of tendons, in Mann RA, Coughlin MJ (eds): Surgeryof the Foot and Ankle, vol 2 (ed 6). St Louis,MO, Mosby, 1992, pp 805-835 3. Wapner KL, AllardyceT, Shea J, et al: Anatomicbasis for tendon selection for reconstructionof ruptures of Achillestendon and posterior tibial tendon. Presented at the American Orthopaedic Foot and Ankle SocietySummerMeeting, Napa, CA, July 1992
ROGER A. MANN
Reconstruction of the Achilles tendon is presented using the flexor digitorum longus (FDL) tendon. The involved area of the Achilles tendon is resected. The remaining tendon is advanced either into the calcaneus if the distal portion has been resected or into the viable portion of the tendon. The FDL is harvested from the plantar aspect of the foot and is used as an intact musclotendinous unit to help re-establish the proper tension of the reconstructed Achilles tendon. KEY WORDS: Achilles tendon reconstruction
The underlying principle of reconstructing the Achilles tendon with the flexor digitorum longus (FDL) is to create an intact musculotendinous unit. By using a normal musculotendinous unit, a new resting length for the posterior calf muscles can be achieved, and the remainder of the Achilles tendon reconstruction can be developed around it. The cross-suturing of the reconstructed portion of the Achilles tendon to the intact musculotendinous structure allows the vascularity of the muscle mass of the tendon transfer to hopefully participate in the revascularization of the reconstructed Achilles tendon. When reconstructing the Achilles tendon, there are several technical problems that the surgeon must be aware of. The first and foremost problem is that the skin around the Achilles tendon and posterior calcaneus has a significant tendency to slough, particularly if previous scars are present. Therefore, it is imperative that all skin flaps are made full thickness and carried directly down to the tendon sheath of the Achilles tendon both distally and proximally. At times, w o u n d closure can also be a problem, because as the reconstructed tendon and transfer are pulled down under tension, tenting of the skin occurs. This can be partially overcome by placing the foot in maximum plantar flexion and using stitches that help keep the tension off of the skin edges.
TECHNIQUE The surgical approach for reconstruction of the Achilles tendon is divided into three parts. The first part is the surgical approach, which exposes the proximal and distal portion of the Achilles tendon; the second is obtaining the FDL from the plantar aspect of the foot; and the third is securing the tendon into the calcaneus.
in private practice, San Leandro, CA.
Address reprint requests to Roger A. Mann, MD, 237 Estudillo Ave, San Leandro, CA 94577. Copyright 9 1994 by W. B. Saunders Company 1048-6666/94/0403-0003505.00/0
138
The procedure is carried out with the patient in a prone position and a tourniquet around the thigh. The initial skin incision is made along the posteromedial aspect of the calf, starting at approximately the midportion of the leg and carried distally, almost bisecting the interval between the medial border of the gastrocnemius and posterior medial border of the tibia. As the incision is brought distally at about the midportion of the calcaneus, it is carried lateralward across the midline for about I cm. The incision is deepened to the sheath of the Achilles tendon proximally and distally. Care is taken not to traumatize the skin edges (Fig 1A). The pathological portion of the Achilles tendon is identified, and having opened the sheath proximally and distally, the two incisions are brought together to expose the abnormal tendon. The neurovascular bundle is located in the vicinity of the anteromedial aspect of the tendon and should be watched for. Having freed the tendon circumferentially, the portion of the tendon that needs to be reconstructed is identified. If the pathology is in the midsubstance of the tendon, that portion is excised, or if the pathology is in the area of the insertion of the tendon, that portion is excised. It is important that as much of the pathological tissue be excised as possible so that, hopefully, normal tendon will be healing together after the reconstruction is carried out. If the surgeon excises the midportion of the tendon well proximal to the insertion, then the central flap that is developed is brought down and sutured into the remaining portion of the tendon. If the portion that is resected is at the insertion of the tendon, then the advanced portion of the tendon needs to be brought d o w n and buried into the calcaneus to create a bony insertion for the tendon. The FDL tendon is now harvested by making an incision along the medial border of the foot, just along the superior margin of the abductor hallucis muscle. The muscle belly is reflected in a plantarward direction, the posterior tibial tendon is identified, and the next tendon plantar to this is the FDL. The tendon is carefully freed from its tendon sheath and traced distally, taking down the master knot of Henry. Some bleeding is often encountered in this area that requires cauterizing. In the
Operative Techniques in Orthopaedics, Vol 4, No 3 (July), 1994: pp 138-140
A
I
Fig 1. (A) The incision used to expose the Achilles tendon is shown. The medial foot incision allows for access to the FDL tendon. (B) Tenodesis of the FDL stump to the flexor hallucis Iongus. (Modified and reprinted with permission. 1'2) ACHILLES TENDON RECONSTRUCTION
Fig 2. (A) The FDL is pulled through the calcaneal drill hole. (B) Augmentation of the defect by spanning the gap with an advanced portion of Achilles tendon. (Modified and reprinted with permission. 1'2) 13g
midportion of the foot where the FDL and flexor hallucis longus cross one another, the tendon is severed. The distal portion of the FDL is sutured into the flexor hallucis longus if adequate cross-connections do not exist (Fig 1A and B). 3 The freed FDL tendon is now pulled into the proximal portion of the wound, and the foot incision is closed in a routine manner. A transverse drill hole is made in the calcaneus, and the FDL tendon is advanced through it and sutured back onto itself (Fig. 2A). As this is carried out, the ankle should be held in approximately 10~ to 15~ of plantar flexion, with the knee bent at a right angle. The tendon is then sutured onto itself to secure it. The central half of the Achilles tendon is now developed and brought distally to either bypass the gap in the tendon if it has been sectioned proximal to the insertion, or brought down into a hole made in the calcaneus if the Achilles tendon was excised at its insertion. As this portion of the procedure is carried out, enough tension must be placed on the reconstructed Achilles tendon so that some semblance of normal musculotendinous tension is restored to the Achilles tendon (Fig 2B). Once this has been carried out and the advanced portion of the Achilles tendon has been sutured to the substance of the Achilles tendon itself, the transferred FDL is cross-sutured to the Achilles tendon. Once this is achieved, the w o u n d is closed in layers over a drain with the subcutaneous layer being carefully closed so that the skin can be brought together under minimal tension. Although the ankle has been set in about 10~ to 15~ of equinus, it can be placed down into more equinus w h e n the w o u n d is closed to keep the tension off of the skin edges. The patient is placed into a snug compression dressing incorporating plaster splints.
140
POSTOPERATIVE CARE The postoperative m a n a g e m e n t includes a dressing change at about 10 days, and if the w o u n d is healed in a satisfactory manner, the ankle is placed into approximately 10~ of equinus. The patient is kept in this position for approximately 2 months, after which gentle range-of-motion exercises are begun, but the immobilization in a removable cast continues. The patient is permitted weight bearing after 3 months, and instructed to gently work on range-of-motion exercises using an elastic band. At 4 months, if the tendon seems to be fairly stable and there is minimal pain and thickening about it, activities are permitted without the cast. If there is still warmth and swelling about the tendon, unprotected weight bearing is not permitted until this subsides. As a general rule, patients are immobilized for 5 to 6 months, after which, if there is any doubt regarding the stability of the transfer and reconstructed area, the patient is placed into a polypropylene ankle/foot orthosis with an articulated ankle and permitted about 10~ of dorsiflexion.
REFERENCES 1. MannRA, HolmesGB, SealeKS, et al: Chronicrupture of the Achilles tendon: A new technique of repair. J BoneJoint Surg [Am] 73: 214-219, 1991 2. PlattnerP, Mann RA: Disorders of tendons, in Mann RA, Coughlin MJ (eds): Surgeryof the Foot and Ankle, vol 2 (ed 6). St Louis,MO, Mosby, 1992, pp 805-835 3. Wapner KL, AllardyceT, Shea J, et al: Anatomicbasis for tendon selection for reconstructionof ruptures of Achillestendon and posterior tibial tendon. Presented at the American Orthopaedic Foot and Ankle SocietySummerMeeting, Napa, CA, July 1992
ROGER A. MANN