The Achilles tendon is the strongest, largest, and thickest tendon in the body,1-7 yet it is the most frequently ruptured tendon,2-5,8 with most ruptures occurring at the watershed area approximately 2 to 6 cm proximal to insertion of the tendon.1,4,6-14
Achilles ruptures are most commonly seen in middle aged males, 30-50 years old, who participate intermittently in recreational athletic activities (often referred to as “weekend warriors”), with 75% of all ruptures occurring during sporting activities.1-4, 6, 8-11, 15 Ruptures additionally can occur in the older patient, usually in those with underlying tendenosis, and may be asymptomatic or subclinical. These patients usually do not feel the classical sensation of being kicked or hit in the calf nor hear an audible snap, and ruptures tend to occur during low-energy activities. As such, these ruptures may be more difficult to recognize and may be more frequently missed on initial evaluation.
Delays in treatment result from decreased pain after the initial injury, as well as misdiagnosis by the first evaluator, in up to 20-36% of patients.1,2,4,6,8-10,15,16 These delays in treatment, whether operative or non-operative, can have detrimental effects on the final outcomes.6,11,14 Loss of Achilles function leads to loss of plantar flexion strength, weakness, fatigue, limp, inability to run, heel rise, play sports, and climb stairs.1,2,4,8,9,11,14
Patients initially present with swelling, complaints of weakness, difficulty walking up and down stairs, loss of balance, and a tendency to fall forward.11 There is wasting in calf muscle and often a palpable gap between the ends of the Achilles tendon. If an acute rupture is missed and becomes chronic, there is 20% less endurance of the muscle and the treatment becomes more difficult.2,14 If the tendon is not repaired or immobilized, retraction of the muscle fibers leads to decreased muscle tension until it becomes zero at about 60% of the fibers’ resting length.8 Although there is debate of what may be considered a chronic injury, 4 to 10 weeks have been used by various authors,1,2,8,11,13,14 since 4 weeks is the earliest time point that has demonstrated histological evidence of chronic healing.13
Treatment Options and Surgical Indications
Missed or neglected ruptures result is significant dysfunction. Non-operative treatment of chronic ruptures includes using a molded ankle-foot orthosis (MAFO). An ankle hinge spring loaded MAFO can add torque and further aid pushoff.11 This may be an excellent option for sedentary, elderly, and surgically unfit patients.14 However, this is less tolerated by more active patients, as it immobilizes the ankle and hindfoot joints, altering limb mechanics and gait.14 Surgical reconstruction should be considered in patients who have failed conservative management, are good surgical candidates, and are active.14 Surgical intervention offers higher activity resumption, less calf atrophy, better ankle movement, and fewer complaints.20
History and Physical
The patient history should include details about the injury such as the duration and the mechanism of injury, as well as any co-morbidities that could have predisposed to the injury and/or influence its management. Both lower limbs should be examined, with calf girths compared. Neurovascular status and the condition of soft tissues in the leg and the foot should be evaluated and documented.
Gait evaluation typically reveals excess ankle dorsiflexion due to the loss of check-reign effect of the Achilles and weakness in step-off.11 The most commonly used exam maneuver for Achilles tendon rupture is the Thompson test.17,18 However, in more chronic ruptures, there will be some degree of plantar flexion on calf compression due to the formation of a scar bridge between the ruptured ends of the Achilles tendon. To avoid a spurious result, the test must be compared to the contralateral side.11,14 In chronic ruptures the resting tension ( Matles test) 1,2,4,5,8,10,11,14,15,19 demonstrates a diminished plantarflexed position of the ankle on the affected side compared to the contralateral side (Figure 1).
Figure 1. Note the decreased resting tension in the injured right ankle as compared to the uninjured left ankle.
A palpable gap in the tendon may be present between the retracted tendon ends; however, in chronic cases, scar tissue with often fill the void, making this test unreliable. Additionally, the contour of the Achilles as viewed posteriorly is usually altered.14 Plantar flexion strength is not a reliable clinical test as it may be influenced by the intact flexor tendons or scar bridging.2,4,9,11,15 However, even patients able to perform a single heel rise are typically unable to perform the maneuver repeatedly,14 and strength remains weaker than on the unaffected side. Finally, passive ankle hyperdorsiflexion compared to the contralateral side is usually present due to elongation of the interposed scar tissue, or “pseudotendon.”11,14
Although the diagnosis is clinically made, imaging studies are recommended. A weight-bearing lateral radiograph of the hindfoot will typically show loss of soft tissue tension and Keegan's trianglar shadow, which is created by an intact AT. Pre-existing degeneration may be associated with calcification in the Achilles tendon. A gap at the rupture site may not be distinct due to scarring. MRI or ultrasonography is useful in accurately determining the extent of the tendon gap preoperatively.11,14 It should be noted that the true tendon gap is usually larger than that estimated on MRI or ultrasound and is determined intraoperatively after resection of nonvital tissue.14
The choice of surgical procedure is generally based on the extent of the gap between the tendon ends. A gap of less than 2 cm can usually be closed with a primary end-to-end repair with gentle traction. A gap of 2 to 5 cm will usually require a V-Y slide lengthening. When the gap is more than 5 cm, V-Y advancement has been hypothesized to result in increased weakness of the muscle unit.11,14 Defects of more than 7 cm will require an Achilles turndown procedure or an allograft replacement.11 Alternatively, a flexor digitorum longus (FDL) or flexor hallucis longus (FHL) transfer as a bridging procedure has been described through a two incision technique.14,21-25 We have previously described a single approach for performing the V-Y advancement and FHL transfer.14
Advantages of using the FHL tendon include its greater size and muscle unit strength, synergistic function with the Achilles, and technically easier transfer through a single incision without having to cross the medial neurovascular bundle.14,25 Also, the distal location of the FHL muscle belly forms a vascular bed adjacent to the dysvascular Achilles repair site.
The patient should be counseled regarding the diagnosis and given an explanation of the options available for management, along with the risks and benefits of each of these options. A likely deficit in great toe flexion power and its effect on athletic activity should be mentioned when reconstruction of the ruptured Achilles tendon is contemplated using the FHL tendon.
The procedure is done on an outpatient basis under general anesthesia with a popliteal block to augment postoperative pain control. A thigh tourniquet is used to allow access to the proximal calf and to prevent the tourniquet from squeezing the gastrocnemius muscle which would decrease mobility of the muscle and prevent accurate tensioning. The patient is positioned prone on well padded chest rolls. Both extremities are prepared and exposed to a level above the knee for surgery. This is to allow for tendon length and tension comparison between the affected and the normal extremities (Figure 2).
Figure 2. The patient is prone. A thigh tourniquet is applied with the connection lateral to avoid pressure points. Both legs are prepped up to the knee.
An extensile posterior incision over the calf is required for the procedure. The initial longitudinal incision is made distally at the rupture level, placed immediately medial to the Achilles tendon to avoid potential sural nerve injury. Once the diagnosis and rupture gap is confirmed, the incision is extended proximally along the posterior midline of the calf and extended to the myotendinous junction (Figure 3). Care should be taken to identify and protect the sural nerve as it crosses from lateral to central in the midcalf area. The nerve is usually found with the lesser saphenous vein, which aids in its identification, and should also be preserved if possible (Figure 4).
Figure 3. The incision is medial distally and curves to the midline proximally.
Figure 4. The sural nerve and lesser saphenous vein are identified and retracted laterally.
At the distal rupture level, a full-thickness incision is sharply made down to and through the paratenon, which is then reflected full thickness together with the skin flap and preserved for later repair. After identifying the ruptured region, the gap is measured (Figure 5). A scar pseudotendon is usually found between the retracted tendon ends and should be resected along with all nonviable ends of the tendon. The true gap can then be measured with the knee flexed to 30 degrees and the ankle held in a resting position matching that of the contralateral side (Figure 6).
Figure 5. The rupture site is identified with the interposed pseudotendon. This should not be used as the gap measurement as it is misleading.
Figure 6. The true gap is measured after debridement of the pseudotendon.
An inverted V incision is made within the myotendenous portion of the gastrocsoleus-Achilles mechanism, with the apex of the V placed midline at the most proximal portion of the myotendinous junction. The limbs of the V diverge to exit through the medial and lateral borders of the tendon (Figure 7). The limbs should be at twice the length of the measured true gap. The V is then incised through the tendinous portion (superficial) only, leaving the underlying muscle fibers intact (Figure 8). A heavy braided non-absorbable suture (No. 2 Fiberwire, Arthrex Inc, Naples, FL, or No. 5 Ethibond, Ethicon-J&J, Piscataway, NJ) is then sutured into the ends of the ruptured tendon using a locking Krakow technique with five locked loops on each of the medial and lateral sides, with the suture ends exiting out of the ends of the rupture stump.
Figure 7. The V is drawn with the apex at the musculotendinous junction and the limbs divergent to exit the medial and lateral borders of the tendon. The length of the limbs should be twice the length of the measured gap.
Login to view presentation on V-Y Advancement and FHL Transfer-Video 8 Incise the V
Figure 8. The V is incised through the tendinous portion (superficial) only, leaving the underlying muscle fibers intact.
The suture is then used to apply longitudinal traction to the proximal tendon stump, while gently teasing the muscle fibers longitudinally, allowing the myotendinous junction to slide distally. It should be done with great patience and care not to detach the tendon from the underlying muscle, which would devascularize the tendon (Figure 9). This is continued until the tendon ends are approximated. At this point, the FHL transfer portion of the procedure should be performed, as described below.
Login to view presentation on V-Y Advancement and FHL Transfer-Video 9 Gently Stretching the Tendon
Figure 9. A suture is used to apply longitudinal traction to the proximal tendon stump, while gently teasing the muscle fibers longitudinally, allowing the myotendinous junction to slide distally.
After the FHL transfer, the tendon ends are repaired using the sutures that were previously placed. The V-shaped incision is now repaired creating an inverted Y, with the long arm of the Y being the length that the tendon was elongated, which is also the length of the measured gap (Figure 10).
Figure 10. After FHL transfer and repair of the ruptured ends, the V-shaped incision is then repaired creating an inverted Y, with the long arm of the Y being the length that the tendon was lengthened and the true gap.
The FHL tendon can be harvested through the same single incision and utilized for the transfer.14 Prior to repairing the Achilles tendon, the deep posterior compartment fascia is incised and released, exposing the FHL muscle and tendon (Figure 11). The FHL muscle belly is usually low-lying and extends to the level of the tibiotalar joint, making it easy to identify (frequently referred to as the “beef at the heel”). The tendon is digitally retracted and flexion of the hallux is observed to confirm that it is the correct tendon (Figure 12).
Login to view presentation on V-Y Advancement and FHL Transfer-Video 11 Identify the FHL Tendon
Figure 11. The FHL muscle belly is usually low-lying and extends to the level of the tibiotalar joint, making it easy to identify.
Login to view presentation on V-Y Advancement and FHL Transfer-Video 12 Verify the FHL Tendon
Figure 12. The FHL tendon is digitally retracted and flexion of the hallux is observed to confirm that it is the correct tendon.
Just medial to the FHL tendon is the medial neurovascular bundle, including the tibial nerve and posterior tibial artery. Dissection of the tendon around the medial malleolus is carried out on the lateral aspect of the tendon sheath to avoid inadvertent injury to the neurovascular bundle. With the ankle and hallux held fully flexed and maximal traction placed on the FHL tendon, the tendon can then be transected as distally as possible (Figure 13). An adequate length is obtained using this technique for most patients (Figure 14). Alternatively, a second incision can be made over the medial longitudinal arch of the foot, and the FHL tendon can be harvested at the master knot of Henry and then pulled out from the posterior incision;21-24 however, this is rarely needed and offers no clinical advantage.14,26
Login to view presentation on V-Y Advancement and FHL Transfer-Video 13 Cutting the FHL Tendon
Figure 13. With the ankle and hallux held fully flexed and maximal traction placed on the FHL tendon, the tendon can then be transected as distally as possible.
Figure 14. The obtained graft has adequate length to be secured to the calcaneal tubercle.
The diameter of the FHL tendon is measured (Figure 15) and a matching-sized bone tunnel is drilled into the posterior tubercle of the calcaneus directly anterior to the Achilles insertion (Figure 16). A suture is placed in the distal portion of the FHL tendon, which is then pulled down into the bone tunnel utilizing a Beath pin (Figures 17). The tendon is tensioned so as to match the resting tension of the unaffected side prior to fixation (Figure 18). An interference screw of the same size as the bone tunnel is used to fix the tendon into the calcaneus (Figure 19). Attention is then turned to the remainder of the V-Y advancement, as described above.
Login to view presentation on V-Y Advancement and FHL Transfer-Video 15 Measuring the FHL Graft
Figure 15. The diameter of the FHL tendon is measured.
Login to view presentation on V-Y Advancement and FHL Transfer-Video 16 Beath Pin for FHL Graft
Figure 16. After the diameter of the FHL tendon is measured, a matching-sized bone tunnel is drilled into the posterior tubercle of the calcaneus directly anterior to the Achilles insertion.
Login to view presentation on V-Y Advancement and FHL Transfer-Video 17 Passing FHL Sutures
Figure 17. A suture is placed in the distal portion of the FHL tendon, which is then pulled down into the bone tunnel utilizing a Beath pin.
Login to view presentation on V-Y Advancement and FHL Transfer-Video 18 Tensioning the FHL Tendon
Figure 18. The FHL tendon is tensioned to match the resting tension of the unaffected side prior to fixation.
Figure 19. An interference screw is used to secure the FHL tendon graft at the appropriate resting tension.
Testing and Closure
At the end of the procedure, the final resting tension is again compared to the contralateral uninjured side (Figure 20). The repair is gently stressed by dorsiflexing the ankle to test for gapping (Figure 21). The paratenon is then closed as a separate layer. The skin is closed in layers and the patient is placed in a well-padded posterior plaster splint with the ankle maintained at its resting tension level of plantar flexion. The tourniquet is then released.
Figure 20. Restoration of resting tension as compared to the uninjured side.
Login to view presentation on V-Y Advancement and FHL Transfer-Video 21 Gently Testing the Repair for Gapping
Figure 21. The repair is gently stressed by dorsiflexing the ankle to test for gapping.
Pearls and Pitfalls11
- Preoperatively, a careful examination of vascularity, skin quality, and healing potential is essential, as wound complications remain a major risk factor.
- During the approach, the sural nerve and saphenous vein should be identified and protected.
- Adequate length, twice that of the rupture gap, should be ensured and used for the limbs of the V in the V-Y advancement. If this is not possible, an alternate procedure, such as an Achilles turndown, should be used in preference to the V-Y procedure. This can be done through the same approach as described above.
- During the advancement, care should be taken to avoid completely disrupt the myotendinous portion from the underlying muscle, thereby devascularizing the tendon. While harvesting the FHL tendon, care must be taken to avoid injury to the neurovascular bundle lying immediately medial to the tendon.
- When drilling the bone tunnel, the ankle should be dorsiflexed so that the bone tunnel is collinear with the Achilles tendon.
- An appropriately sized interference screw should be used to ensure adequate fit.
- Ensure that the tendon is adequately tensioned to match the unaffected side prior to fixation.
- A careful repair of the paratenon is essential as it contains a rich vascular supply important to the repair. Additionally, it aids in preventing adhesions of the tendon to the skin and subcutaneous tissues.
The extremity is maintained in a splint in slight equinus for 2 weeks post-operatively. The patients is maintained strictly non-weightbearing for the first 6 weeks. At the 2-week postoperative visit, the incisions are checked and sutures are removed. The patient is then converted to an Achilles-type hindfoot boot (Bledsoe Inc., Grand Prairie, TX) with three hindfoot wedges and instructed to remove one wedge in 2 weeks (4 weeks post-operatively).
At 6 weeks, the patient is clinically evaluated again and the tendon integrity and function is tested. The patient is then allowed to start weightbearing in the Achilles boot brace with two remaining wedges, as comfort allows. One wedge should be removed every 2 weeks (at 8 and 10 weeks post-operatively). Physical therapy is also started at that point, two or three times a week for 10 weeks. Therapy should concentrate on passive Achilles stretching, Achilles strengthening, and gait training.
At the 12-week visit, the patient's boot is discontinued if the ankle is in neutral alignment. The patient is allowed to slowly resume activity as comfort allows but to avoid sudden accelerations, cutting, or jumping until at least 6 months after surgery.
Outcomes of chronic or neglected Achilles tendon rupture repair are uniformly inferior to acute rupture repairs.11 In our previous study,14 we found that patients undergoing reconstruction with a V-Y advancement and an FHL transfer had a decrease in active range of motion and plantar flexion torque at both 60 and 120 degrees per second. We demonstrated the ability to restore 86% of power and 78% of strength compared to the contralateral side. Clinically, 11 patients (73%) were able to perform a single leg heel raise and five of them were able to perform 20 repetitions of this on the operative side. Ten patients reported their satisfaction as very good and 5 as good; all of them would recommend the procedure or undergo it again.14 AOFAS hindfoot scale scores improved from 58.4 preoperatively to 94.1 at final follow-up.
Takao et al27 reported deficits of up to 23% in 10 patients with neglected Achilles ruptures treated with gastrocnemius fascial flaps. Several others have reported similar results.28,29 Wapner et al23,24 reported on outcomes using FHL transfer only without V-Y advancement and showed 30% reduction in strength at 30 degrees per second, and a decrease of 41.8% and 51% in torque and work generated by plantar flexion of the ankle, respectively.
A potential concern about FHL tendon transfer is the loss of active interphalangeal joint plantar flexion function of the hallux. In one study, patients were unaware of the functional weakness of their hallux even though pedobarography showed reduced peak pressure load in the distal phalanx.30
Wound complications are always a concern in foot and ankle surgeries. In our study, we had one superficial wound dehiscence. Others have reported similar results. Although re-rupture is a concern, with incidence of re-rupture after acute or chronic rupture repair estimated to be 1.4-3.7%,20 no ruptures have been reported when using FHL transfer.24,31-33
There is a concern regarding tearing of the muscle during elongation greater than 4-5 cm during the V-Y portion of the procedure, but we have found that slow, gentle, but consistent traction helps avoid this. Plantar flexion weakness is a common outcome of the procedure. Sural neuritis or nerve injury is has also been reported, as has deep venous thrombosis.
- Heckman DS, Gluck GS, Parekh SG. Tendon disorders of the foot and ankle, part 2: Achilles tendon disorders. Am J Sports Med. 2009;37(6):1223-34.
- Padanilam TG. Chronic Achilles tendon ruptures. Foot Ankle Clin. 2009;14(4):711-28.
- Worth N, Ghosh S, Maffulli N. Management of acute Achilles tendon ruptures in the United Kingdom. J Orthop Surg (Hong Kong). 2007;15(3):311-4.
- Longo UG, Ronga M, Maffulli N. Acute ruptures of the achilles tendon. Sports Med Arthrosc. 2009;17(2):127-38.
- Maffulli N. The clinical diagnosis of subcutaneous tear of the Achilles tendon. A prospective study in 174 patients. Am J Sports Med. 1998;26(2):266-70.
- Chiodo CP, Wilson MG. Current concepts review: acute ruptures of the achilles tendon. Foot Ankle Int. 2006;27(4):305-13.
- el-Khoury GY, Brandser EA, Saltzman CL. MRI of tendon injuries. Iowa Orthop J. 1994;14:65-80.
- Maffulli N, Ajis A, Longo UG, Denaro V. Chronic rupture of tendo Achillis. Foot Ankle Clin. 2007;12(4):583-96, vi.
- Krahe MA, Berlet GC. Achilles tendon ruptures, re rupture with revision surgery, tendinosis, and insertional disease. Foot Ankle Clin. 2009;14(2):247-75.
- Movin T, Ryberg A, McBride DJ, Maffulli N. Acute rupture of the Achilles tendon. Foot Ankle Clin. 2005;10(2):331-56.
- Raikin SM. V-Y Advancement and Flexor Hallucis Longus Transfer for the Chronic or Neglected Achilles Tendon Rupture, in Operative Techniques in Foot and Ankle Surgery. Editors: Easley ME, Wiesel SW. Philadelphia, Lippincott, Williams & Wilkins, 2011. Pages: 918-25.
- Calleja M, Connell DA. The Achilles tendon. Semin Musculoskelet Radiol. 2010;14(3):307-22.
- Reddy SS, Pedowitz DI, Parekh SG, Omar IM, Wapner KL. Surgical treatment for chronic disease and disorders of the achilles tendon. J Am Acad Orthop Surg. 2009;17(1):3-14.
- Elias I, Besser M, Nazarian LN, Raikin SM. Reconstruction for missed or neglected Achilles tendon rupture with V-Y lengthening and flexor hallucis longus tendon transfer through one incision. Foot Ankle Int. 2007;28(12):1238-48.
- Maffulli N, Ajis A. Management of chronic ruptures of the Achilles tendon. J Bone Joint Surg Am. 2008;90(6):1348-60.
- Cetti R, Andersen I. Roentgenographic diagnoses of ruptured Achilles tendons. Clin Orthop Relat Res. 1993;(286):215-21.
- Simmonds FA. The diagnosis of the ruptured Achilles tendon. Practitioner. 1957;179(1069):56-8.
- Thompson TC, Doherty JH. Spontaneous rupture of tendon of Achilles: a new clinical diagnostic test. J Trauma. 1962;2:126-9.
- Matles AL. Rupture of the tendo Achilles. Another diagnostic sign. Bull Hosp Joint Dis. 1975;36(1):48-51.
- Cetti R, Christensen SE, Ejsted R, Jensen NM, Jorgensen U. Operative versus nonoperative treatment of Achilles tendon rupture. A prospective randomized study and review of the literature. Am J Sports Med. 1993;21(6):791-9.
- Martin RL, Manning CM, Carcia CR, Conti SF. An outcome study of chronic Achilles tendinosis after excision of the Achilles tendon and flexor hallucis longus tendon transfer. Foot Ankle Int. 2005;26(9):691-7.
- Monroe MT, Dixon DJ, Beals TC, Pomeroy G, Crowley DL, Manoli A. Plantarflexion torque following reconstruction of Achilles tendinosis or rupture with flexor hallucis longus augmentation. Foot Ankle Int. 2000;21(4):324-9.
- Wapner KL, Hecht PJ, Mills RH, Jr. Reconstruction of neglected Achilles tendon injury. Orthop Clin North Am. 1995;26(2):249-63.
- Wapner KL, Pavlock GS, Hecht PJ, Naselli F, Walther R. Repair of chronic Achilles tendon rupture with flexor hallucis longus tendon transfer. Foot Ankle. 1993;14(8):443-9.
- Mann RA, Holmes GB, Jr., Seale KS, Collins DN. Chronic rupture of the Achilles tendon: a new technique of repair. J Bone Joint Surg Am. 1991;73(2):214-9.
- Tashjian RZ, Hur J, Sullivan RJ, Campbell JT, DiGiovanni CW. Flexor hallucis longus transfer for repair of chronic achilles tendinopathy. Foot Ankle Int. 2003;24(9):673-6.
- Takao M, Ochi M, Naito K, Uchio Y, Matsusaki M, Oae K. Repair of neglected Achilles tendon rupture using gastrocnemius fascial flaps. Arch Orthop Trauma Surg. 2003;123(9):471-4.
- Kissel CG, Blacklidge DK, Crowley DL. Repair of neglected Achilles tendon ruptures--procedure and functional results. J Foot Ankle Surg. 1994;33(1):46-52.
- Us AK, Bilgin SS, Aydin T, Mergen E. Repair of neglected Achilles tendon ruptures: procedures and functional results. Arch Orthop Trauma Surg. 1997;116(6-7):408-11.
- Coull R, Flavin R, Stephens MM. Flexor hallucis longus tendon transfer: evaluation of postoperative morbidity. Foot Ankle Int. 2003;24(12):931-4.
- Den Hartog BD. Flexor hallucis longus transfer for chronic Achilles tendonosis. Foot Ankle Int. 2003;24(3):233-7.
- Wilcox DK, Bohay DR, Anderson JG. Treatment of chronic achilles tendon disorders with flexor hallucis longus tendon transfer/augmentation. Foot Ankle Int. 2000;21(12):1004-10.
- Wong MW, Ng VW. Modified flexor hallucis longus transfer for Achilles insertional rupture in elderly patients. Clin Orthop Relat Res. 2005;(431):201-6.