- Email: [email protected]
The dorsal bunion: an overview
Foot and Ankle Surgery 11 (2005) 65–68 www.elsevier.com/locate/fas
Review
The dorsal bunion: an overview Adrien Albert*, Thibaut Leemrijse Cliniques Universitaires Saint-Luc, Brussels, Belgium Received 9 November 2004; accepted 14 December 2004
Abstract The authors reviewed available publications concerning the dorsal bunion, a vertical deformity of the first ray of the foot. After describing the clinical side and the usual patient complaints, they analyse the lesion’s mechanisms, based on the muscular imbalance of the foot and its joints and describe the causes to the dorsal bunion, especially clubfoot and its surgical correction. The numerous surgical treatments of the dorsal bunion are detailed by order of publication. Then the authors report a recent case of dorsal bunion with illustrations before and after surgery. q 2005 European Foot and Ankle Societ. Published by Elsevier Ireland Ltd. All rights reserved. Keywords: Dorsal bunion; Clubfoot; First metatarsal
1. Introduction The dorsal bunion is a common symptom of many foot diseases, mostly in children. Its primary definition is a bunion above the first metatarsal head. Many causes of dorsal bunion are described. Clinical features always include a dorsiflexion of the first metatarsal associated with plantar-flexion at the metatarso-phalangeal (MTP) joint, an extension of its interphalangeal (IP) joint and a bunion. The deformation is apparent in the unloaded foot but becomes accentuated when the patient is walking or weight-bearing. The complaints are aesthetics, pain and walking instability.
2. Discussion 2.1. Pathogenesis of the dorsal bunion Many origins are described in the literature; they all include a muscular imbalance of the foot. This results in * Corresponding author. Address: Service d’orthope´die et de Traumatologie de l’ Appareil Locomoteur, AV. Hippocrate, 10, 1200 Brussels, Belgium. E-mail addresses: [email protected] (A. Albert), thibaut. [email protected] (T. Leemrijse).
a deformity of the medial arch that affects the mechanics of the foot. In the incipient stage, the deformity is not fixed and remains supple but becomes stiff after a period of time. The treatment then is more difficult and can afford a complementary arthrodesis. The pathology includes the typical bunion at the head of the first metatarsal, and metatarsalgia, commonly under the central metatarsal heads but can be located laterally in a global forefoot supination. Two primary mechanisms were distinguished by Hammond [2] and Lapidus [6]. † The most common one is a primary dorsiflexion of the first metatarsal that brings about the secondary activation of the hallux plantar flexors. The flexion of the first hallux phalangeal contributes to stabilise the first metatarsal’s horizontal position. This mechanism explains why a global forefoot supination can be at the origin of a dorsal bunion in paralytic feet. † The second one is a primary plantar-flexion of the big toe with secondary upward displacement of the first metatarsal. In some paralytic feet the plantar flexing forces of the first metatarsal head are insufficient and the hallux active flexion is then used to support the push-off while walking or to help stabilise the foot during weightbearing. The area of weight-bearing of the first metatarsal head is then shifted forward to the IP joint and contributes to the development of a dorsal bunion.
1268-7731/$ - see front matter q 2005 European Foot and Ankle Societ. Published by Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.fas.2004.12.004
66
A. Albert, T. Leemrijse / Foot and Ankle Surgery 11 (2005) 65–68
Lapidus [6] describes this primary active flexion associated with hallux rigidus. 2.2. About muscles active on the first ray of the foot The primary origin of the deformity is the muscular imbalance [6] of the first ray associated with the suppleness of its joints, mostly the first MTP. Four muscles are involved: † Peroneus longus muscle. It seems to be the most important muscle involved in dorsal bunion pathology. Its function is to stabilise the first metatarsal head to the ground during the stance phase and later push-off. Its deficiency induces a compensation by the flexors of the hallux. An isolated palsy of the peroneus longus does not seem to result in a muscular imbalance and does not lead to the development of a dorsal bunion except in young children, probably because of the suppleness of their joints. Meary [8] reports an interesting case following peroneal tendon dislocation following clubfoot surgery. Kuo [5] reports a dorsal bunion with intact peroneus longus muscle. † Flexor hallucis brevis muscle. Its action, together with the intrinsic muscles is to flex the MTP joint. Their overuse is, as previously said, often the consequence of other abnormalities of the foot. They contribute to strengthen the elevation of the first metatarsal head and may therefore be responsible for the painful bunion. † Tibialis anterior muscle. This muscle is the antagonist of the peroneus longus muscle and its integrity or overactivity is required for the development of a dorsal bunion. An anomality of its bone insertion or its retraction can be found in congenital clubfoot and partly explains the natural tendency of these feet to develop a dorsal bunion. † According to Meary [8], weakness of the gastroc-soleus muscle is important in the development of the deformity. 2.3. Main clinical syndromes causing the deformity of the DB Many clinical syndromes related to the dorsal bunion are described in the literature. Historically the most common cause is the paralytic foot, especially following poliomyelitis. Currently, the most frequent one is the clubfoot itself and its corrective surgery. (a) Clubfoot. It includes different predisposing factors: the mobility of the joints due to the young age, a malaligned hind foot, a weak peroneus longus muscle, and insertion anomalies with a normal or excessive function of the tibialis anterior muscle. (b) Following clubfoot surgery. Kuo [5] concludes that the main factors leading to dorsal bunion are weakness of the Achilles tendon, excessive power of the flexor
hallucis longus muscle, forefoot supination with a strong anterior tibial tendon, and weakness of the peroneus longus tendon. (c) Global forefoot supination. It can be primary or follow surgery. (d) Paralytic deformities of the foot. The most common causes described in the literature are poliomyelitis, disc hernia, compartmental syndrome, direct nerve injury and Charcot–Marie–Tooth syndrome. Lapidus [6] describes three categories of paralytic feet: † Weak peroneus longus with a strong tibialis anterior strong hallux flexors. † Weak dorsiflexors of the foot and strong plantar flexors of the great toe. † Calcaneus deformity with active plantar flexors of the big toe.
(e) Hallux rigidus. Dorsiflexion of the hallux and weightbearing on the ball of the big toe are painful and lead to an antalgic position of the foot. The patient keeps the big toe in plantar-flexion and holds the forefoot in slight supination. In time there is a lost of extension of the first phalanx of the big toe followed by dorsal exostosis of the first metatarsal. The weight-bearing area under the first metatarsal head is then displaced under the IP joint and contributes to the development of the cutaneous lesion. (f) Some other clinical syndromes are less frequently related to the dorsal bunion and can be cited; their mechanisms are the same as those previously described: hallux valgus surgery, severe congenital talipes planovalgus, Lisfranc joint dislocation. 2.4. Principles of the treatment of the DB Many surgical treatments have been proposed. Each of them in accords with the author’s understanding of the pathogenesis of dorsal bunion. † The first treatment was proposed by Hohmann [3] and consisted of a simple removal of the dorsal exostosis or resection of basal phalanx. Because of the lack of understanding of the dorsal bunion by its author, this procedure resulted in a prompt recurrence of the deformity. † The reverse Jones procedure is the transfer of the long hallux flexor insertion on the head of the first metatarsal. It cuts out the flexor action of this muscle and contributes to pull the first metatarsal down. † Lapidus [6] in 1940 proposed a new sophisticated surgical procedure for the correction of the deformity. A first incision exposes the first MTP joint that is opened. A second one is made along the dorsomedial border of the forefoot and exposes the first cuneiform-metatarsal joint and, if necessary, the first cuneiform-navicular joint. A wedge-shaped resection with a plantar-base is
A. Albert, T. Leemrijse / Foot and Ankle Surgery 11 (2005) 65–68
†
†
†
†
then performed at the first cuneiform-metatarsal joint and, if necessary, at the first cuneiform-navicular joint. The flexor hallucis longus is then severed from its insertion and pulled dorsally through an oblique bone channel drilled in the shaft of the first metatarsal. The distal end of the flexor is anchored to the dorsal capsule of the first MTP joint. The author especially recommends this procedure for paralytic feet with strong flexors and weak extensors of the big toe. Three years later, Hammond [2] proposed an athrodesis for fixed deformities resembling the one described by Lapidus but associated with transfer of the deforming muscle, tibialis anterior or peroneus longus, to the head of the third metatarsal. He proposed a tibial graft in the dorsal gap of the MTP joint. If the deformity is not yet fixed, the arthrodesis is unnecessary but the progressive character of the pathology always justifies the transfer of the involved tendon. The procedure described by Meary [8] in 1956 is a transfer of flexors of the toe’s first phalanx on the neck of the first metatarsal. A first longitudinal incision on the medial side of the foot allows exposure of the lateral sesamoid and its two muscular heads (external head of the flexor hallucis brevis and abductor hallucis). A second incision at the first intermetatarsal space exposes the lateral head of the flexor hallucis brevis and the oblique head of the adductor hallucis on the lateral sesamoid. Muscular heads are then inserted into the first metatarsal neck. This technique is difficult to perform and the author prefers the Lapidus procedure with flexor hallucis longus transfer. Tachdjian [10] proposes an osteotomy of the base of the first metatarsal, a capsulorrhaphy of the MTP joint and a transfer of the flexor hallucis longus to the head of the first metatarsal. McKay [7] describes in 1983 a procedure for children. He transfers the tendons of abductor hallucis, both heads of the flexor hallucis brevis, the oblique and transverse
Fig. 1. The typical painful DB in front of the first metatarsal head of the left foot.
67
Fig. 2. X-ray of the left foot, showing the horizontal alignment of the first metatarsal, flexion of the first MTP and an extension of the IPP joint of the hallux.
heads of the adductor hallucis from the base of the proximal phalanx to the neck of the first metatarsal to create a myotendinous ring. The author recommends the suture of the flexor hallucis longus at the base of the proximal phalanx and the interphalangeal joint arthodesis as a complimentary procedure. † Johnson [4] recommends the procedure described by McKay [7] associated to a transfer of the flexor hallucis longus. He also recommended the tibialis anterior transfer to the second metatarsal as described by Hammond [2]. † The desupinative tarsectomy [9] can be performed if the primary lesion is an excessive supination of the forefoot. It includes an osteotomy at the Lisfranc joint or at the mid-foot. The desupination movement is obtained by a triangular plantar-base bone resection. A triangular bone graft can be inserted at the level of the osteotomy. Minor supination can be corrected by a frontal forefoot rotation but this creates incongruance between the bone fragments.
Fig. 3. Direct postoperative appearance of the foot, showing the reduced subcutaneous deformity.
68
A. Albert, T. Leemrijse / Foot and Ankle Surgery 11 (2005) 65–68
We present the preoperative and postoperative pictures of the foot with the corresponding X-ray (Figs. 1–4).
4. Conclusion
Fig. 4. Postoperative X-ray, showing the first metatarsal correction.
† The last available source [1] proposes a lengthening or a transfer of the tibialis anterior tendon with a plantarbased closing wedge osteotomy of the medial cuneiform and capsulorraphy of the MTP joint. The first results seem to be encouraging.
3. Case report We report the case of a 26 years old patient, previously treated surgically for a congenital clubfoot at age one. She presented in 2003 with a dorsal bunion, a reducible hindfoot supination, a calcaneus deformity and claw toes. She complained of metatarsalgia. † We first corrected the claw toes of the second and third rays by a transfer of the flexor digitorum brevis on the flexor digitorum longus with a lengthening effect. The claw toe deformations of the fourth and fifth rays were corrected by flexor tenotomy. † The dorsal bunion was then treated as described by Lapidus [6]. We performed a wedge-shaped resection with plantar-base at the first cuneiform-metatarsal joint and fixed the first metatarsal with a compressive screw. We drilled an oblique bone channel running from the proximal plantar aspect to the distal dorsal aspect of the first metatarsal. Then we threaded the flexor hallucis longus tendon, pulled it dorsally through the bone channel and fixed the tendon at the dorsal aspect of the neck of the first metatarsal. † We finally corrected the hindfoot supination by a split tibialis anterior tendon transfer to the cuboid. Results. We obtained a very good correction of the forefoot alignment and the metatarsalgia improved.
The Dorsal Bunion is a clinical feature of a complex pathology of the first ray of the foot. It is important to give attention to the clinical and surgical context, anatomic abnormalities, paralysis, and to a possible rigidity of the first toe. A thorough clinical examination and a precise understanding of each deformity is essential to determine the most effective treatment. Among the numerous origins of the dorsal bunion, club feet are the most interesting because of their frequency and their iatrogenic character. In these cases it is also very important to identify the exact origin of the abnormality and to keep in mind their natural proclivity to develop a dorsal bunion. Often there is a surgically induced abnormality of the first ray, less frequently a global supination of the hindfoot. In the first case, the ‘Reverse Jones’ seems to bring a simple and effective solution. The value of the other surgical procedures is difficult to assess objectivity because of the few published cases. Except Meary [8], whose technique was copied by McKay [7], all authors are satisfied with their results. Arthrodesis is indicated for fixed deformities and the tarsectomy must be reserved for severe global forefoot supination.
References [1] Ryan DD. Dorsal bunion: a new corrective procedure. 70th annual meeting. Poster board number P180. American Academy of Orthopaedic Surgeons; February 2003. [2] Hammond G. Elevation of the first metatarsal bone with hallux equinus. Surgery 1943;13:240–56. [3] Hohmann G. Fuss und bein: ihre erkrankungen und deren behandlung 2 aufl. Bergmann, e´dit. Munich; 1934. [4] Johnson CE, Roach RW. Dorsal bunion following clubfoot surgery. Orthopedics 1985;8:1036–40. [5] Kuo KN. ‘Reverse Jones’ procedure for dorsal bunion following clufoot surgery. In: Simons GW, editor. The clubfoot, the present and a view of the future. Springer 1994; 384–90. [6] Lapidus PW. Dorsal bunion: its mechanics and operative correction. J Bone Joint Surg 1940;22:627–37. [7] McKay DW. Dorsal bunions in children. J Bone Joint Surg 1983;65: 975–80. [8] Meary R. Sur une forme particulie`re de de´faut d’appui plantaire ante´ro-interne du pied. Revue d’Orthope´die 1956;42:235–45. [9] Meyer M, Tomeno B. Le de´faut d’appui plantaire ante´ro-interne. Revue de Chirurgie Orthope´dique 1976;62:463–73. [10] Tachdjian, MO. Pediatric Orthopedics. Saunders. pp. 994–995. Philadelphia, WB Saunders; 1972.
Review
The dorsal bunion: an overview Adrien Albert*, Thibaut Leemrijse Cliniques Universitaires Saint-Luc, Brussels, Belgium Received 9 November 2004; accepted 14 December 2004
Abstract The authors reviewed available publications concerning the dorsal bunion, a vertical deformity of the first ray of the foot. After describing the clinical side and the usual patient complaints, they analyse the lesion’s mechanisms, based on the muscular imbalance of the foot and its joints and describe the causes to the dorsal bunion, especially clubfoot and its surgical correction. The numerous surgical treatments of the dorsal bunion are detailed by order of publication. Then the authors report a recent case of dorsal bunion with illustrations before and after surgery. q 2005 European Foot and Ankle Societ. Published by Elsevier Ireland Ltd. All rights reserved. Keywords: Dorsal bunion; Clubfoot; First metatarsal
1. Introduction The dorsal bunion is a common symptom of many foot diseases, mostly in children. Its primary definition is a bunion above the first metatarsal head. Many causes of dorsal bunion are described. Clinical features always include a dorsiflexion of the first metatarsal associated with plantar-flexion at the metatarso-phalangeal (MTP) joint, an extension of its interphalangeal (IP) joint and a bunion. The deformation is apparent in the unloaded foot but becomes accentuated when the patient is walking or weight-bearing. The complaints are aesthetics, pain and walking instability.
2. Discussion 2.1. Pathogenesis of the dorsal bunion Many origins are described in the literature; they all include a muscular imbalance of the foot. This results in * Corresponding author. Address: Service d’orthope´die et de Traumatologie de l’ Appareil Locomoteur, AV. Hippocrate, 10, 1200 Brussels, Belgium. E-mail addresses: [email protected] (A. Albert), thibaut. [email protected] (T. Leemrijse).
a deformity of the medial arch that affects the mechanics of the foot. In the incipient stage, the deformity is not fixed and remains supple but becomes stiff after a period of time. The treatment then is more difficult and can afford a complementary arthrodesis. The pathology includes the typical bunion at the head of the first metatarsal, and metatarsalgia, commonly under the central metatarsal heads but can be located laterally in a global forefoot supination. Two primary mechanisms were distinguished by Hammond [2] and Lapidus [6]. † The most common one is a primary dorsiflexion of the first metatarsal that brings about the secondary activation of the hallux plantar flexors. The flexion of the first hallux phalangeal contributes to stabilise the first metatarsal’s horizontal position. This mechanism explains why a global forefoot supination can be at the origin of a dorsal bunion in paralytic feet. † The second one is a primary plantar-flexion of the big toe with secondary upward displacement of the first metatarsal. In some paralytic feet the plantar flexing forces of the first metatarsal head are insufficient and the hallux active flexion is then used to support the push-off while walking or to help stabilise the foot during weightbearing. The area of weight-bearing of the first metatarsal head is then shifted forward to the IP joint and contributes to the development of a dorsal bunion.
1268-7731/$ - see front matter q 2005 European Foot and Ankle Societ. Published by Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.fas.2004.12.004
66
A. Albert, T. Leemrijse / Foot and Ankle Surgery 11 (2005) 65–68
Lapidus [6] describes this primary active flexion associated with hallux rigidus. 2.2. About muscles active on the first ray of the foot The primary origin of the deformity is the muscular imbalance [6] of the first ray associated with the suppleness of its joints, mostly the first MTP. Four muscles are involved: † Peroneus longus muscle. It seems to be the most important muscle involved in dorsal bunion pathology. Its function is to stabilise the first metatarsal head to the ground during the stance phase and later push-off. Its deficiency induces a compensation by the flexors of the hallux. An isolated palsy of the peroneus longus does not seem to result in a muscular imbalance and does not lead to the development of a dorsal bunion except in young children, probably because of the suppleness of their joints. Meary [8] reports an interesting case following peroneal tendon dislocation following clubfoot surgery. Kuo [5] reports a dorsal bunion with intact peroneus longus muscle. † Flexor hallucis brevis muscle. Its action, together with the intrinsic muscles is to flex the MTP joint. Their overuse is, as previously said, often the consequence of other abnormalities of the foot. They contribute to strengthen the elevation of the first metatarsal head and may therefore be responsible for the painful bunion. † Tibialis anterior muscle. This muscle is the antagonist of the peroneus longus muscle and its integrity or overactivity is required for the development of a dorsal bunion. An anomality of its bone insertion or its retraction can be found in congenital clubfoot and partly explains the natural tendency of these feet to develop a dorsal bunion. † According to Meary [8], weakness of the gastroc-soleus muscle is important in the development of the deformity. 2.3. Main clinical syndromes causing the deformity of the DB Many clinical syndromes related to the dorsal bunion are described in the literature. Historically the most common cause is the paralytic foot, especially following poliomyelitis. Currently, the most frequent one is the clubfoot itself and its corrective surgery. (a) Clubfoot. It includes different predisposing factors: the mobility of the joints due to the young age, a malaligned hind foot, a weak peroneus longus muscle, and insertion anomalies with a normal or excessive function of the tibialis anterior muscle. (b) Following clubfoot surgery. Kuo [5] concludes that the main factors leading to dorsal bunion are weakness of the Achilles tendon, excessive power of the flexor
hallucis longus muscle, forefoot supination with a strong anterior tibial tendon, and weakness of the peroneus longus tendon. (c) Global forefoot supination. It can be primary or follow surgery. (d) Paralytic deformities of the foot. The most common causes described in the literature are poliomyelitis, disc hernia, compartmental syndrome, direct nerve injury and Charcot–Marie–Tooth syndrome. Lapidus [6] describes three categories of paralytic feet: † Weak peroneus longus with a strong tibialis anterior strong hallux flexors. † Weak dorsiflexors of the foot and strong plantar flexors of the great toe. † Calcaneus deformity with active plantar flexors of the big toe.
(e) Hallux rigidus. Dorsiflexion of the hallux and weightbearing on the ball of the big toe are painful and lead to an antalgic position of the foot. The patient keeps the big toe in plantar-flexion and holds the forefoot in slight supination. In time there is a lost of extension of the first phalanx of the big toe followed by dorsal exostosis of the first metatarsal. The weight-bearing area under the first metatarsal head is then displaced under the IP joint and contributes to the development of the cutaneous lesion. (f) Some other clinical syndromes are less frequently related to the dorsal bunion and can be cited; their mechanisms are the same as those previously described: hallux valgus surgery, severe congenital talipes planovalgus, Lisfranc joint dislocation. 2.4. Principles of the treatment of the DB Many surgical treatments have been proposed. Each of them in accords with the author’s understanding of the pathogenesis of dorsal bunion. † The first treatment was proposed by Hohmann [3] and consisted of a simple removal of the dorsal exostosis or resection of basal phalanx. Because of the lack of understanding of the dorsal bunion by its author, this procedure resulted in a prompt recurrence of the deformity. † The reverse Jones procedure is the transfer of the long hallux flexor insertion on the head of the first metatarsal. It cuts out the flexor action of this muscle and contributes to pull the first metatarsal down. † Lapidus [6] in 1940 proposed a new sophisticated surgical procedure for the correction of the deformity. A first incision exposes the first MTP joint that is opened. A second one is made along the dorsomedial border of the forefoot and exposes the first cuneiform-metatarsal joint and, if necessary, the first cuneiform-navicular joint. A wedge-shaped resection with a plantar-base is
A. Albert, T. Leemrijse / Foot and Ankle Surgery 11 (2005) 65–68
†
†
†
†
then performed at the first cuneiform-metatarsal joint and, if necessary, at the first cuneiform-navicular joint. The flexor hallucis longus is then severed from its insertion and pulled dorsally through an oblique bone channel drilled in the shaft of the first metatarsal. The distal end of the flexor is anchored to the dorsal capsule of the first MTP joint. The author especially recommends this procedure for paralytic feet with strong flexors and weak extensors of the big toe. Three years later, Hammond [2] proposed an athrodesis for fixed deformities resembling the one described by Lapidus but associated with transfer of the deforming muscle, tibialis anterior or peroneus longus, to the head of the third metatarsal. He proposed a tibial graft in the dorsal gap of the MTP joint. If the deformity is not yet fixed, the arthrodesis is unnecessary but the progressive character of the pathology always justifies the transfer of the involved tendon. The procedure described by Meary [8] in 1956 is a transfer of flexors of the toe’s first phalanx on the neck of the first metatarsal. A first longitudinal incision on the medial side of the foot allows exposure of the lateral sesamoid and its two muscular heads (external head of the flexor hallucis brevis and abductor hallucis). A second incision at the first intermetatarsal space exposes the lateral head of the flexor hallucis brevis and the oblique head of the adductor hallucis on the lateral sesamoid. Muscular heads are then inserted into the first metatarsal neck. This technique is difficult to perform and the author prefers the Lapidus procedure with flexor hallucis longus transfer. Tachdjian [10] proposes an osteotomy of the base of the first metatarsal, a capsulorrhaphy of the MTP joint and a transfer of the flexor hallucis longus to the head of the first metatarsal. McKay [7] describes in 1983 a procedure for children. He transfers the tendons of abductor hallucis, both heads of the flexor hallucis brevis, the oblique and transverse
Fig. 1. The typical painful DB in front of the first metatarsal head of the left foot.
67
Fig. 2. X-ray of the left foot, showing the horizontal alignment of the first metatarsal, flexion of the first MTP and an extension of the IPP joint of the hallux.
heads of the adductor hallucis from the base of the proximal phalanx to the neck of the first metatarsal to create a myotendinous ring. The author recommends the suture of the flexor hallucis longus at the base of the proximal phalanx and the interphalangeal joint arthodesis as a complimentary procedure. † Johnson [4] recommends the procedure described by McKay [7] associated to a transfer of the flexor hallucis longus. He also recommended the tibialis anterior transfer to the second metatarsal as described by Hammond [2]. † The desupinative tarsectomy [9] can be performed if the primary lesion is an excessive supination of the forefoot. It includes an osteotomy at the Lisfranc joint or at the mid-foot. The desupination movement is obtained by a triangular plantar-base bone resection. A triangular bone graft can be inserted at the level of the osteotomy. Minor supination can be corrected by a frontal forefoot rotation but this creates incongruance between the bone fragments.
Fig. 3. Direct postoperative appearance of the foot, showing the reduced subcutaneous deformity.
68
A. Albert, T. Leemrijse / Foot and Ankle Surgery 11 (2005) 65–68
We present the preoperative and postoperative pictures of the foot with the corresponding X-ray (Figs. 1–4).
4. Conclusion
Fig. 4. Postoperative X-ray, showing the first metatarsal correction.
† The last available source [1] proposes a lengthening or a transfer of the tibialis anterior tendon with a plantarbased closing wedge osteotomy of the medial cuneiform and capsulorraphy of the MTP joint. The first results seem to be encouraging.
3. Case report We report the case of a 26 years old patient, previously treated surgically for a congenital clubfoot at age one. She presented in 2003 with a dorsal bunion, a reducible hindfoot supination, a calcaneus deformity and claw toes. She complained of metatarsalgia. † We first corrected the claw toes of the second and third rays by a transfer of the flexor digitorum brevis on the flexor digitorum longus with a lengthening effect. The claw toe deformations of the fourth and fifth rays were corrected by flexor tenotomy. † The dorsal bunion was then treated as described by Lapidus [6]. We performed a wedge-shaped resection with plantar-base at the first cuneiform-metatarsal joint and fixed the first metatarsal with a compressive screw. We drilled an oblique bone channel running from the proximal plantar aspect to the distal dorsal aspect of the first metatarsal. Then we threaded the flexor hallucis longus tendon, pulled it dorsally through the bone channel and fixed the tendon at the dorsal aspect of the neck of the first metatarsal. † We finally corrected the hindfoot supination by a split tibialis anterior tendon transfer to the cuboid. Results. We obtained a very good correction of the forefoot alignment and the metatarsalgia improved.
The Dorsal Bunion is a clinical feature of a complex pathology of the first ray of the foot. It is important to give attention to the clinical and surgical context, anatomic abnormalities, paralysis, and to a possible rigidity of the first toe. A thorough clinical examination and a precise understanding of each deformity is essential to determine the most effective treatment. Among the numerous origins of the dorsal bunion, club feet are the most interesting because of their frequency and their iatrogenic character. In these cases it is also very important to identify the exact origin of the abnormality and to keep in mind their natural proclivity to develop a dorsal bunion. Often there is a surgically induced abnormality of the first ray, less frequently a global supination of the hindfoot. In the first case, the ‘Reverse Jones’ seems to bring a simple and effective solution. The value of the other surgical procedures is difficult to assess objectivity because of the few published cases. Except Meary [8], whose technique was copied by McKay [7], all authors are satisfied with their results. Arthrodesis is indicated for fixed deformities and the tarsectomy must be reserved for severe global forefoot supination.
References [1] Ryan DD. Dorsal bunion: a new corrective procedure. 70th annual meeting. Poster board number P180. American Academy of Orthopaedic Surgeons; February 2003. [2] Hammond G. Elevation of the first metatarsal bone with hallux equinus. Surgery 1943;13:240–56. [3] Hohmann G. Fuss und bein: ihre erkrankungen und deren behandlung 2 aufl. Bergmann, e´dit. Munich; 1934. [4] Johnson CE, Roach RW. Dorsal bunion following clubfoot surgery. Orthopedics 1985;8:1036–40. [5] Kuo KN. ‘Reverse Jones’ procedure for dorsal bunion following clufoot surgery. In: Simons GW, editor. The clubfoot, the present and a view of the future. Springer 1994; 384–90. [6] Lapidus PW. Dorsal bunion: its mechanics and operative correction. J Bone Joint Surg 1940;22:627–37. [7] McKay DW. Dorsal bunions in children. J Bone Joint Surg 1983;65: 975–80. [8] Meary R. Sur une forme particulie`re de de´faut d’appui plantaire ante´ro-interne du pied. Revue d’Orthope´die 1956;42:235–45. [9] Meyer M, Tomeno B. Le de´faut d’appui plantaire ante´ro-interne. Revue de Chirurgie Orthope´dique 1976;62:463–73. [10] Tachdjian, MO. Pediatric Orthopedics. Saunders. pp. 994–995. Philadelphia, WB Saunders; 1972.