- Email: [email protected]
Reconstruction of Neglected Flexor Hallucis Longus Tendon Rupture: A Case Report
The Journal of Foot & Ankle Surgery 57 (2018) 1256–1258
Contents lists available at ScienceDirect
The Journal of Foot & Ankle Surgery j o u r n a l h o m e p a g e : w w w. j f a s . o r g
Reconstruction of Neglected Flexor Hallucis Longus Tendon Rupture: A Case Report Nikolaos Anastasopoulos, MD, PhD 1, George Paraskevas, MD, PhD 2, Nikolaos Lazaridis, MD, PhD 3, Konstantinos Natsis, MD, PhD 4 1Orthopedic
Surgeon and Assistant Professor, Department of Anatomy and Surgical Anatomy, Faculty of Health Sciences, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece Professor, Department of Anatomy and Surgical Anatomy, Faculty of Health Sciences, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece 3 Lecturer, Department of Anatomy and Surgical Anatomy, Faculty of Health Sciences, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece 4Professor, Department of Anatomy and Surgical Anatomy, Faculty of Health Sciences, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece 2Associate
A R T I C L E
I N F O
Level of Clinical Evidence: 4
Keywords: chronic tendon rupture flexor hallucis longus tendon great toe injury plantaris tendon graft surgical repair
A B S T R A C T
Isolated rupture of the flexor hallucis longus tendon is an unusual injury. We present the case of a neglected flexor hallucis longus tendon closed traumatic rupture at the plantar aspect of the first phalangeal head of the great toe in a middle-age male. The injury occurred while he was dancing. Because end-toend tendon suture was impossible, the ensuing gap was repaired using a free plantaris tendon graft. We present the operative repair benefit of the flexor hallucis longus tendon rupture to regain the function and strength of the interphalangeal joint of the hallux, avoid extension of the distal phalanx, and maintain the longitudinal arch of the foot. © 2018 by the American College of Foot and Ankle Surgeons. All rights reserved.
Isolated rupture of the flexor hallucis longus (FHL) tendon is an unusual injury. FHL rupture is usually associated with trauma and, occasionally, autoimmune disease such as diabetes mellitus, systemic lupus erythematosus, Reiter’s disease, and chronic renal failure, or corticosteroid use (1). These systemic diseases have an effect on the vascular or innate tissue quality. Trauma can be either an open injury, causing laceration to the plantar aspect of the foot or at the base of the toe, or closed, resulting from repetitive injuries causing tendinitis or stenosing tenosynovitis. The FHL tendon is the most common site of tenosynovitis in ballet dancers, and it has also been described in long-distance runners (2). Closed rupture of the FHL tendon can also be complete or partial. Injury to the FHL can occur anywhere along the course of the tendon. The site of disruption can be categorized into 3 different anatomic zones: distal to the sesamoids in the area just proximal to FHL insertion (zone 1), between the sesamoids and the knot of Henry (zone 2), and proximal to the knot of Henry (zone 3). This classification has an obvious clinical effect because disruption in zone 3 will lead to proximal retraction of the tendon but injuries in zones 1 and 2 will not,
Financial Disclosure: None reported. Conflict of Interest: None reported. Address correspondence to: Nikolaos Lazaridis, MD, PhD, Department of Anatomy and Surgical Anatomy, Faculty of Health Sciences, School of Medicine, Aristotle University of Thessaloniki, PO Box 300, 54124 Thessaloniki, Greece. E-mail address: [email protected] (N. Lazaridis).
owing to the fibrous slip connecting the FHL and flexor digitorum longus (FDL) (3). A total of 35 cases of complete or partial closed rupture have been reported (4). Closed complete rupture of the FHL tendon at the base or the head of proximal phalanx was reported in 2 cases (4,5). We present the case of chronic complete subcutaneous rupture of the FHL tendon at the distal phalangeal head after forceful dorsiflexion of the great toe. We present the operative repair using a free plantaris tendon (PT) graft and discuss the importance of a postoperative functional brace and an aggressive rehabilitation program. To the best of our knowledge, ours is the first report of this specific injury treated with a free PT graft. Case Report A 48-year-old, otherwise fit and healthy, male had slipped during dancing and sustained a violent dorsiflexion of his right great toe. He experienced sudden intensive pain under his forefoot but continued dancing. He reported pain while walking, and a mild swelling over the plantar aspect of right great toe appeared thereafter. Conservative treatment was unsuccessful, including nonsteroidal antiinflammatory drugs and physiotherapy. The patient sought medical attention 10 months after the injury. On presentation, he complained of being unable to flex the distal phalanx of his great toe. In addition, pain and subjective loss of push-off power with walking, running, and jumping was apparent. The medical history of the patient
1067-2516/$ - see front matter © 2018 by the American College of Foot and Ankle Surgeons. All rights reserved. https://doi.org/10.1053/j.jfas.2018.03.041
N. Anastasopoulos et al. / The Journal of Foot & Ankle Surgery 57 (2018) 1256–1258
Fig. 1. Sagittal T2-weighted short T1 inversion recovery magnetic resonance image showing loss of flexor hallucis longus tendon continuity, with distal stump (arrows) at the level of the first phalangeal head and the proximal stump appearing thickened and lying just proximal to the metatarsal head.
revealed that 40 days before his injury acute unilateral facial nerve palsy (Bell’s palsy) had been diagnosed, and he had been prescribed oral prednisolone, 60 mg daily for 5 days, tapered by 10 mg daily for the next 5 days. On physical examination, the patient demonstrated mild swelling and moderate tenderness at the plantar surface of the metatarsophalangeal (MTP) joint between the sesamoid bones. Passive plantarflexion and extension of the interphalangeal (IP) joint of the hallux were normal, but active plantarflexion was not possible. Active flexion in the first MTP joint and all other MTP joints was unimpaired, indicating that the flexor hallucis brevis and FDL tendons were intact. The findings from plain radiographs of the right foot and ankle were normal. Magnetic resonance imaging of the foot demonstrated a complete rupture of the FHL tendon (Fig. 1). The residual proximal stump appeared thickened and was lying just proximal to the metatarsal head; the distal end was present at the level of the first phalangeal head. Fluid collection was also noted around the proximal stump (Fig. 1). Operative repair of the FHL tendon was undertaken with the patient under general anesthesia and placed in a prone position in March 2015. Under tourniquet control, a plantar longitudinal incision on
1257
the sole of the foot (9 to 10 cm long), centered over the MTP joint and extending to the flexor fold of the great toe, was used to avoid damage to the medial branch of the medial plantar nerve. We incised the tendon sheath, but no tendon was seen (Fig. 2A). The ruptured distal and proximal ends of the FHL tendon were identified. The distal caput of the FHL tendon had been interrupted ~2 to 3 cm from its insertion. The tendon was frayed and thinned (Fig. 2A). The proximal stump was found 3 to 4 cm proximally to the intersesamoid region. It was short, thickened, and degenerative in appearance (Fig. 2A). Because end-to-end tendon suturing was impossible, we restored the 7-cm existing gap using a free PT graft (Fig. 2B). A small 2-cm skin incision was made at the medial border of the Achilles tendon insertion at the calcaneal tuberosity. The PT was located by blunt dissection, mobilized, and harvested using a blunt tendon stripper from distally to proximally. After debridement, the distal caput of the FHL tendon was sutured to the PT graft using no. 2-0 FiberWire suture (Arthrex, Naples, FL) and secured with a 2.7-mm anchor at the base of the first phalange of the great toe (Fig. 2B). The proximal end of the ruptured tendon was pulled down and sutured directly to the other end of the graft, using the strengthened modified Kessler technique (Fig. 2B). The skin was closed with 3-0 nylon mattress sutures. Postoperative treatment consisted of below-the-knee cast immobilization, with mild equinus at the ankle and neutral position of the hallux, for 3 weeks. The cast extended distally to the toes to prevent dorsiflexion of the metatarsophalangeal joint. Weightbearing was initiated 4 weeks after surgery. A functional brace, allowing active extension and passive flexion, was applied for 6 more weeks, and the patient was encouraged to actively flex and extend the great toe thereafter. His physical capacity was improved by an aggressive postoperative rehabilitation program, which included water running and bicycling. At the final follow-up examination at 18 months postoperative, 32° of active flexion of the IP joint was noted and the first MTP joint movements were normal (Fig. 3). The passive movement at the IP joint was also normal. The patient’s great toe was normally positioned, and his distal phalanx was not hyperextended. The patient was able to support the great toe while running, and he had noted no inconvenience or pain during his daily activities.
Fig. 2. (A) Intraoperative photograph showing distal (arrow) and proximal (arrowhead) stump of the ruptured tendon. The distal caput of the flexor hallucis longus tendon seemed frayed and thinned and had been interrupted ~2 to 3 cm from its insertion. The proximal caput seemed short, thickened, and degenerative in appearance. (B) Intraoperative photograph showing restoration of the existing gap with a free plantaris tendon graft.
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Fig. 3. At 18 months postoperatively, 32° of active flexion of the interphalangeal joint was observed.
Discussion The FHL anatomy is complicated and its tendon is 1 of the longest in the lower extremity. The FHL arises from the distal two thirds of the posterior surface of the fibula (except for its lowest 2.5 cm); the adjacent interosseous membrane and the posterior crural intermuscular septum; and the fascia covering the tibialis posterior muscle (6). The FHL tendon courses behind the talus, running down behind the medial malleolus inferior to the sustentaculum tali of the calcaneus. In the plantar aspect of the foot, the tendon of the FHL crosses the tendon of the FDL from laterally to medially (6). At the crossing point, the so-called knot of Henry, it gives off 2 strong slips to the medial 2 divisions of the FDL tendons and then crosses the lateral part of the flexor hallucis brevis to reach the interval between the sesamoid bones under the head of the first metatarsal (6). It continues on the plantar aspect of the hallux and attaches to the plantar aspect of the base of the distal phalanx (6). The FHL not only flexes the great toe, but also contributes, together with the plantar fascia, to the distribution of forces at the plantar side of the forefoot, thus supporting the longitudinal arch of the foot (7). When the foot is on the ground and under load, both the FHL and FDL maintain the pads of the toes in firm contact with the ground and stabilize the heads of the metatarsal bones, which form the fulcrum on which the body is propelled forward, becoming very active during toe-off and tip-toe movements (6). Thus, the FHL has been referred to as the Achilles tendon of the foot by Hamilton (8). The FHL tendon is prone to injury in the foot and ankle region, including tears and partial injuries, especially among ballet dancers and athletes who engage in repetitive push-off maneuvers (9). Experience with FHL tendon injury repair has mainly involved laceration cases. More rarely, these injuries present as closed complete ruptures. To the best of our knowledge, Krackow (10) was the first to describe a closed complete rupture of the FHL tendon in 1980; this traumatic rupture occurred in a 34-year-old male who had dorsiflexed the ankle, foot, and great toe against resistance while diving. Concerning the site of rupture, it can occur in specific areas. Inokuchi and Usami (11) described a rupture at the posterior process of the talus. Other cases have occurred at Henry’s knot (12) or just distal to the tendinous slip connecting the FHL to the FDL (13). Advancing distally, another site of rupture could be at the head of the first metatarsal (14). Rupture could also occur at the base of the second phalanx of the great toe (10) or at the proximal phalangeal head (4). The case we have presented occurred after violent dorsiflexion of the great toe against resistance. The site of rupture was located 2 to 3 cm from the tendon’s insertion, at the level of the first phalangeal head. A gap of 7 cm was present, probably due to the previous prednisolone treatment.
Operative treatment of an FHL tendon rupture includes tendon suture, tendon transplantation, and tenodesis to the FDL (4). Pain relief is the main indication for surgical intervention according to Wei et al (12). Krackow (10) observed that the strength of push-off can be improved after repair; thus, surgical repair should be considered if the patient’s physical activities are highly demanding. The adverse effect of nonoperative treatment with the loss of push-off and the consequent gait imbalance led us to conclude that all ruptures of the FHL should undergo surgical repair. IP joint mobility is often decreased after suturing, although the crucial function of the great toe during gait, which is push off and stabilization pressure up to the neutral joint position, will be restored (15). In distal chronic tears, if direct repair is not possible, some investigators have recommended using a free tendon graft, such as the PT, Achilles tendon, or even fascia lata (11,16). Heikkila et al (16) used a wide slip of Achilles tendon as a graft in a world class runner with chronic rupture of the FHL tendon. However, because of the formed adhesions, even the best performed procedure cannot guarantee that complete function will be restored. Thus, use of a free tendon graft requires an aggressive postoperative rehabilitation program and the use of a functional brace (16). In conclusion, we have presented a case of neglected chronic closed rupture of the FHL tendon at the level of the first phalangeal head treated with a free PT graft. We decided to repair the injured tendon to alleviate our patient’s pain and restore the push-off power for walking, running, and jumping. Hyperextension of the distal phalanx was avoided, and a quantifiable amount of active plantarflexion of the great toe was achieved. We observed no gait disturbances or imbalance or thrust problems. Even in chronic cases, a successful return to running and daily activities is feasible. To the best of our knowledge, ours is the first report of this specific injury treated with free PT graft.
References 1. Gillott E, Ray PS. Repair of iatrogenic rupture of the flexor hallucis longus tendon following an Akin osteotomy: a case report and review of the literature. Foot Ankle Online J 5:1, 2012. 2. Petersen W, Pufe T, Zantop T, Paulsen F. Blood supply of the flexor hallucis longus tendon with regard to dancer’s tendinitis: injection and immunohistochemical studies of cadaver tendons. Foot Ankle Int 24:591–606, 2003. 3. Coughlin MJ, Mann RA, Saltzman CL. Surgery of the Foot and Ankle, pp. 1177–1178, Mosby-Elsevier, Philadelphia, 2007. 4. Noda D, Yoshimura I, Kanazawa K, Hagio T, Naito M. Subcutaneous rupture of the flexor hallucis longus tendon: a case report. J Foot Ankle Surg 51:234–236, 2012. 5. Sato K, Moriwaki M. A case of subcutaneous rupture of flexor hallucis longus. Rinsho Seikei Geka 18:1317–1320, 1983. 6. Standring S. Gray’s Anatomy, p. 1423, Elsevier Churchill Livingstone, Edinburgh, 2008. 7. Hamel AJ, Donahue AW, Sharkey NA. Contribution of active and passive toe flexion to forefoot loading. Clin Orthop Relat Res 393:326–334, 2001. 8. Hamilton WG. Tendonitis about the ankle joint in classical ballet dancers. Am J Sports Med 5:84–88, 1977. 9. Sammarco GJ, Cooper PS. Flexor hallucis longus tendon injury in dancers and nondancers. Foot Ankle Int 19:356–362, 1998. 10. Krackow KA. Acute, traumatic rupture of a flexor hallucis longus tendon: a case report. Clin Orthop Relat Res 150:261–262, 1980. 11. Inokuchi S, Asami N. Closed complete rupture of the flexor hallucis longus tendon at the groove of the talus. Foot Ankle Int 18:47–49, 1997. 12. Wei SY, Kneeland JB, Okereke E. Complete atraumatic rupture of the flexor hallucis longus tendon: a case report and review of the literature. Foot Ankle Int 19:472–474, 1998. 13. Coghlan BA, Clarke NM. Traumatic rupture of the flexor hallucis longus tendon in a marathon runner. Am J Sports Med 21:617–618, 1993. 14. Romash MM. Closed rupture of the flexor hallucis longus tendon in a long distance runner: report of a case and review of the literature. Foot Ankle Int 15:433–435, 1994. 15. Pagenstert GI, Valderrabano V, Hintermann B. Tendon injuries of the foot and ankle in athletes. Schweiz Z Sportmed Sporttraumatologie 52:11–21, 2004. 16. Heikkila JT, Mattila K, Alanen J, Orava S. Chronic rupture of flexor hallucis longus tendon in a world class runner. Foot Ankle Surg 10:71–74, 2004.
Contents lists available at ScienceDirect
The Journal of Foot & Ankle Surgery j o u r n a l h o m e p a g e : w w w. j f a s . o r g
Reconstruction of Neglected Flexor Hallucis Longus Tendon Rupture: A Case Report Nikolaos Anastasopoulos, MD, PhD 1, George Paraskevas, MD, PhD 2, Nikolaos Lazaridis, MD, PhD 3, Konstantinos Natsis, MD, PhD 4 1Orthopedic
Surgeon and Assistant Professor, Department of Anatomy and Surgical Anatomy, Faculty of Health Sciences, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece Professor, Department of Anatomy and Surgical Anatomy, Faculty of Health Sciences, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece 3 Lecturer, Department of Anatomy and Surgical Anatomy, Faculty of Health Sciences, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece 4Professor, Department of Anatomy and Surgical Anatomy, Faculty of Health Sciences, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece 2Associate
A R T I C L E
I N F O
Level of Clinical Evidence: 4
Keywords: chronic tendon rupture flexor hallucis longus tendon great toe injury plantaris tendon graft surgical repair
A B S T R A C T
Isolated rupture of the flexor hallucis longus tendon is an unusual injury. We present the case of a neglected flexor hallucis longus tendon closed traumatic rupture at the plantar aspect of the first phalangeal head of the great toe in a middle-age male. The injury occurred while he was dancing. Because end-toend tendon suture was impossible, the ensuing gap was repaired using a free plantaris tendon graft. We present the operative repair benefit of the flexor hallucis longus tendon rupture to regain the function and strength of the interphalangeal joint of the hallux, avoid extension of the distal phalanx, and maintain the longitudinal arch of the foot. © 2018 by the American College of Foot and Ankle Surgeons. All rights reserved.
Isolated rupture of the flexor hallucis longus (FHL) tendon is an unusual injury. FHL rupture is usually associated with trauma and, occasionally, autoimmune disease such as diabetes mellitus, systemic lupus erythematosus, Reiter’s disease, and chronic renal failure, or corticosteroid use (1). These systemic diseases have an effect on the vascular or innate tissue quality. Trauma can be either an open injury, causing laceration to the plantar aspect of the foot or at the base of the toe, or closed, resulting from repetitive injuries causing tendinitis or stenosing tenosynovitis. The FHL tendon is the most common site of tenosynovitis in ballet dancers, and it has also been described in long-distance runners (2). Closed rupture of the FHL tendon can also be complete or partial. Injury to the FHL can occur anywhere along the course of the tendon. The site of disruption can be categorized into 3 different anatomic zones: distal to the sesamoids in the area just proximal to FHL insertion (zone 1), between the sesamoids and the knot of Henry (zone 2), and proximal to the knot of Henry (zone 3). This classification has an obvious clinical effect because disruption in zone 3 will lead to proximal retraction of the tendon but injuries in zones 1 and 2 will not,
Financial Disclosure: None reported. Conflict of Interest: None reported. Address correspondence to: Nikolaos Lazaridis, MD, PhD, Department of Anatomy and Surgical Anatomy, Faculty of Health Sciences, School of Medicine, Aristotle University of Thessaloniki, PO Box 300, 54124 Thessaloniki, Greece. E-mail address: [email protected] (N. Lazaridis).
owing to the fibrous slip connecting the FHL and flexor digitorum longus (FDL) (3). A total of 35 cases of complete or partial closed rupture have been reported (4). Closed complete rupture of the FHL tendon at the base or the head of proximal phalanx was reported in 2 cases (4,5). We present the case of chronic complete subcutaneous rupture of the FHL tendon at the distal phalangeal head after forceful dorsiflexion of the great toe. We present the operative repair using a free plantaris tendon (PT) graft and discuss the importance of a postoperative functional brace and an aggressive rehabilitation program. To the best of our knowledge, ours is the first report of this specific injury treated with a free PT graft. Case Report A 48-year-old, otherwise fit and healthy, male had slipped during dancing and sustained a violent dorsiflexion of his right great toe. He experienced sudden intensive pain under his forefoot but continued dancing. He reported pain while walking, and a mild swelling over the plantar aspect of right great toe appeared thereafter. Conservative treatment was unsuccessful, including nonsteroidal antiinflammatory drugs and physiotherapy. The patient sought medical attention 10 months after the injury. On presentation, he complained of being unable to flex the distal phalanx of his great toe. In addition, pain and subjective loss of push-off power with walking, running, and jumping was apparent. The medical history of the patient
1067-2516/$ - see front matter © 2018 by the American College of Foot and Ankle Surgeons. All rights reserved. https://doi.org/10.1053/j.jfas.2018.03.041
N. Anastasopoulos et al. / The Journal of Foot & Ankle Surgery 57 (2018) 1256–1258
Fig. 1. Sagittal T2-weighted short T1 inversion recovery magnetic resonance image showing loss of flexor hallucis longus tendon continuity, with distal stump (arrows) at the level of the first phalangeal head and the proximal stump appearing thickened and lying just proximal to the metatarsal head.
revealed that 40 days before his injury acute unilateral facial nerve palsy (Bell’s palsy) had been diagnosed, and he had been prescribed oral prednisolone, 60 mg daily for 5 days, tapered by 10 mg daily for the next 5 days. On physical examination, the patient demonstrated mild swelling and moderate tenderness at the plantar surface of the metatarsophalangeal (MTP) joint between the sesamoid bones. Passive plantarflexion and extension of the interphalangeal (IP) joint of the hallux were normal, but active plantarflexion was not possible. Active flexion in the first MTP joint and all other MTP joints was unimpaired, indicating that the flexor hallucis brevis and FDL tendons were intact. The findings from plain radiographs of the right foot and ankle were normal. Magnetic resonance imaging of the foot demonstrated a complete rupture of the FHL tendon (Fig. 1). The residual proximal stump appeared thickened and was lying just proximal to the metatarsal head; the distal end was present at the level of the first phalangeal head. Fluid collection was also noted around the proximal stump (Fig. 1). Operative repair of the FHL tendon was undertaken with the patient under general anesthesia and placed in a prone position in March 2015. Under tourniquet control, a plantar longitudinal incision on
1257
the sole of the foot (9 to 10 cm long), centered over the MTP joint and extending to the flexor fold of the great toe, was used to avoid damage to the medial branch of the medial plantar nerve. We incised the tendon sheath, but no tendon was seen (Fig. 2A). The ruptured distal and proximal ends of the FHL tendon were identified. The distal caput of the FHL tendon had been interrupted ~2 to 3 cm from its insertion. The tendon was frayed and thinned (Fig. 2A). The proximal stump was found 3 to 4 cm proximally to the intersesamoid region. It was short, thickened, and degenerative in appearance (Fig. 2A). Because end-to-end tendon suturing was impossible, we restored the 7-cm existing gap using a free PT graft (Fig. 2B). A small 2-cm skin incision was made at the medial border of the Achilles tendon insertion at the calcaneal tuberosity. The PT was located by blunt dissection, mobilized, and harvested using a blunt tendon stripper from distally to proximally. After debridement, the distal caput of the FHL tendon was sutured to the PT graft using no. 2-0 FiberWire suture (Arthrex, Naples, FL) and secured with a 2.7-mm anchor at the base of the first phalange of the great toe (Fig. 2B). The proximal end of the ruptured tendon was pulled down and sutured directly to the other end of the graft, using the strengthened modified Kessler technique (Fig. 2B). The skin was closed with 3-0 nylon mattress sutures. Postoperative treatment consisted of below-the-knee cast immobilization, with mild equinus at the ankle and neutral position of the hallux, for 3 weeks. The cast extended distally to the toes to prevent dorsiflexion of the metatarsophalangeal joint. Weightbearing was initiated 4 weeks after surgery. A functional brace, allowing active extension and passive flexion, was applied for 6 more weeks, and the patient was encouraged to actively flex and extend the great toe thereafter. His physical capacity was improved by an aggressive postoperative rehabilitation program, which included water running and bicycling. At the final follow-up examination at 18 months postoperative, 32° of active flexion of the IP joint was noted and the first MTP joint movements were normal (Fig. 3). The passive movement at the IP joint was also normal. The patient’s great toe was normally positioned, and his distal phalanx was not hyperextended. The patient was able to support the great toe while running, and he had noted no inconvenience or pain during his daily activities.
Fig. 2. (A) Intraoperative photograph showing distal (arrow) and proximal (arrowhead) stump of the ruptured tendon. The distal caput of the flexor hallucis longus tendon seemed frayed and thinned and had been interrupted ~2 to 3 cm from its insertion. The proximal caput seemed short, thickened, and degenerative in appearance. (B) Intraoperative photograph showing restoration of the existing gap with a free plantaris tendon graft.
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Fig. 3. At 18 months postoperatively, 32° of active flexion of the interphalangeal joint was observed.
Discussion The FHL anatomy is complicated and its tendon is 1 of the longest in the lower extremity. The FHL arises from the distal two thirds of the posterior surface of the fibula (except for its lowest 2.5 cm); the adjacent interosseous membrane and the posterior crural intermuscular septum; and the fascia covering the tibialis posterior muscle (6). The FHL tendon courses behind the talus, running down behind the medial malleolus inferior to the sustentaculum tali of the calcaneus. In the plantar aspect of the foot, the tendon of the FHL crosses the tendon of the FDL from laterally to medially (6). At the crossing point, the so-called knot of Henry, it gives off 2 strong slips to the medial 2 divisions of the FDL tendons and then crosses the lateral part of the flexor hallucis brevis to reach the interval between the sesamoid bones under the head of the first metatarsal (6). It continues on the plantar aspect of the hallux and attaches to the plantar aspect of the base of the distal phalanx (6). The FHL not only flexes the great toe, but also contributes, together with the plantar fascia, to the distribution of forces at the plantar side of the forefoot, thus supporting the longitudinal arch of the foot (7). When the foot is on the ground and under load, both the FHL and FDL maintain the pads of the toes in firm contact with the ground and stabilize the heads of the metatarsal bones, which form the fulcrum on which the body is propelled forward, becoming very active during toe-off and tip-toe movements (6). Thus, the FHL has been referred to as the Achilles tendon of the foot by Hamilton (8). The FHL tendon is prone to injury in the foot and ankle region, including tears and partial injuries, especially among ballet dancers and athletes who engage in repetitive push-off maneuvers (9). Experience with FHL tendon injury repair has mainly involved laceration cases. More rarely, these injuries present as closed complete ruptures. To the best of our knowledge, Krackow (10) was the first to describe a closed complete rupture of the FHL tendon in 1980; this traumatic rupture occurred in a 34-year-old male who had dorsiflexed the ankle, foot, and great toe against resistance while diving. Concerning the site of rupture, it can occur in specific areas. Inokuchi and Usami (11) described a rupture at the posterior process of the talus. Other cases have occurred at Henry’s knot (12) or just distal to the tendinous slip connecting the FHL to the FDL (13). Advancing distally, another site of rupture could be at the head of the first metatarsal (14). Rupture could also occur at the base of the second phalanx of the great toe (10) or at the proximal phalangeal head (4). The case we have presented occurred after violent dorsiflexion of the great toe against resistance. The site of rupture was located 2 to 3 cm from the tendon’s insertion, at the level of the first phalangeal head. A gap of 7 cm was present, probably due to the previous prednisolone treatment.
Operative treatment of an FHL tendon rupture includes tendon suture, tendon transplantation, and tenodesis to the FDL (4). Pain relief is the main indication for surgical intervention according to Wei et al (12). Krackow (10) observed that the strength of push-off can be improved after repair; thus, surgical repair should be considered if the patient’s physical activities are highly demanding. The adverse effect of nonoperative treatment with the loss of push-off and the consequent gait imbalance led us to conclude that all ruptures of the FHL should undergo surgical repair. IP joint mobility is often decreased after suturing, although the crucial function of the great toe during gait, which is push off and stabilization pressure up to the neutral joint position, will be restored (15). In distal chronic tears, if direct repair is not possible, some investigators have recommended using a free tendon graft, such as the PT, Achilles tendon, or even fascia lata (11,16). Heikkila et al (16) used a wide slip of Achilles tendon as a graft in a world class runner with chronic rupture of the FHL tendon. However, because of the formed adhesions, even the best performed procedure cannot guarantee that complete function will be restored. Thus, use of a free tendon graft requires an aggressive postoperative rehabilitation program and the use of a functional brace (16). In conclusion, we have presented a case of neglected chronic closed rupture of the FHL tendon at the level of the first phalangeal head treated with a free PT graft. We decided to repair the injured tendon to alleviate our patient’s pain and restore the push-off power for walking, running, and jumping. Hyperextension of the distal phalanx was avoided, and a quantifiable amount of active plantarflexion of the great toe was achieved. We observed no gait disturbances or imbalance or thrust problems. Even in chronic cases, a successful return to running and daily activities is feasible. To the best of our knowledge, ours is the first report of this specific injury treated with free PT graft.
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