Dislocation of the first metatarsophalangeal joint concomitant with Lisfranc joint dislocation in a 45-year-old man
- Kanoko Mizumoto ,
- Tadashi Kimura ,
- Makoto Kubota and
- Mitsuru Saito
- Department of Orthopaedic Surgery, Jikei University School of Medicine, Tokyo, Japan
- Correspondence to Dr Tadashi Kimura; tadashi-kimura@jikei.ac.jp
Abstract
A 45-year-old man presented with severe pinch-point crush injury to his left foot. Plain radiographs revealed dislocation of the first metatarsophalangeal joint and dorsolateral dislocation of the basal phalanx and sesamoids. The first tarsometatarsal joint was subluxed in the plantar direction and the second to fourth tarsometatarsal joints were subluxed dorsally. The sesamoids were displaced dorsolateral to the metatarsal head. There was a longitudinal tear of the joint capsule at the medial margin of the medial sesamoid, which was sutured together with the abductor hallucis tendon and collateral ligament. The Lisfranc and dorsal ligaments in the tarsometatarsal joint were torn and repaired after reduction and fixed with a plate. One year after surgery, there was contracture of the first metatarsophalangeal joint, but the patient had no pain and was able to run.
Background
Most traumatic dislocations of the first metatarsophalangeal (MTP) joint are dorsal, and lateral dislocations are very rare.1 In this article, we report a case of lateral dislocation of the first MTP joint concomitant with a Lisfranc dislocation fracture.
Case presentation
A 45-year-old man sustained a crush injury to his left foot when it became caught between a fork and a wall while he was operating a forklift truck. He was found to have a dislocated first MTP joint and was referred to our department immediately because closed reduction had been considered too difficult. Our department has seen dislocation of the first MTP joint in less than five cases.
Initial examination revealed a skin abrasion and severe swelling on the dorsal aspect of the MTP joint of the great toe, which was fixed like a spring in the dorsiflexed position (figure 1).
Findings on initial medical examination show (A) an abrasion and swelling on the dorsal side of the first metatarsophalangeal joint and (B) the toe fixed like a spring in the dorsiflexed position.
Investigations
Plain radiographs showed that the first MTP joint was dislocated and that the basal phalanx and sesamoids were markedly dislocated dorsolaterally (figure 2). CT images showed that the first tarsometatarsal (TMT) joint was subluxed in the plantar direction, the second to fourth TMT joints were subluxed dorsally, and there was a fracture at the base of the second metatarsal. There was no obvious fracture of the sesamoids, which were displaced dorsolateral to the metatarsal head (figure 3).
Plain radiographs showing dislocation of the first metatarsophalangeal joint and marked dorsolateral dislocation of the proximal phalanx along with the sesamoids: (A) anteroposterior view, (B) lateral view and (C) oblique view.
CT images: (A) coronal slice, (B) sagittal slice and (C, D) three-dimensional images. The first tarsometatarsal joint is subluxed in the plantar direction and the second to fourth tarsometatarsal joints are subluxed dorsally. The sesamoids are displaced dorsolateral to the metatarsal head.
Treatment
Given the difficulty of performing closed reduction under a sciatic nerve block, we performed an open reduction on the same day. Exploration via a medial incision over the first MTP joint revealed that the abductor hallucis, medial collateral ligament and capsule were torn. Moreover, the plantar plate and the flexor hallucis longus were displaced lateral to the metatarsal head and trapped, which prevented reduction (figure 4). The first MTP joint was reduced by lifting the metatarsal head with traction on the great toe in the plantar medial direction after releasing the soft tissue that was interfering with reduction. Plain radiographs obtained after reduction showed that the first MTP joint and the Lisfranc joint were in the correct anatomical positions (figure 5). In this case, the plantar plate prevented reduction, so after the first operation we performed MRI, which is known to be very useful in detecting soft tissue and ligamentous injuries, to evaluate the possibility of an incomplete tear. MRI showed that the plantar plate was partially damaged but not severely torn. Therefore, we decided there was no need to repair it. The Lisfranc ligament showed high signal on short tau inversion recovery images (figure 6). We performed internal fixation to stabilise the forefoot on day 12 after the injury when the swelling had subsided. Exploration of the first MTP joint via the previous incision showed that the plantar plate and the intersesamoid ligament were intact, but that there was a longitudinal tear of the joint capsule at the medial margin of the medial sesamoid, which was sutured together with the abductor hallucis tendon and the collateral ligament using a suture anchor on the medial side of the proximal phalanx. Thus, the first MTP joint was stabilised by this process. Exploration of the first TMT joint and between the second and third TMT joints using a dorsal approach showed rupture of the Lisfranc ligament and the dorsal TMT ligaments. The dorsal ligaments were sutured and the first, second and third TMT joints were fixed with a plate (figure 7). Calcaneal gait was started on the first week, range of motion exercise for the toes was commenced on the second week, and partial weightbearing was started on the fourth week postoperatively using a rigid sole plate to provide adequate support for the arch of the foot. Full weightbearing was allowed on the seventh week after surgery. The plate was removed 4 months postoperatively.
Primary surgery consisted of reducing the first metatarsophalangeal joint with pulling of the flexor hallucis longus that was displaced lateral to the metatarsal head.
Plain radiographs acquired after open reduction show the anatomical positions of the metatarsophalangeal joint and the Lisfranc joint: (A) anteroposterior view and (B) lateral view.
MRI acquired after open reduction. (A) An axial short tau inversion recovery image showing that the Lisfranc ligament has a high signal. (B) A sagittal short tau inversion recovery image showing that the plantar plate is partially damaged but not severely torn. (C) A coronal T1-weighted image.
Plain radiographs obtained after internal fixation: (A) anteroposterior view and (B) lateral view. The first to third tarsometatarsal joints are fixed with plates.
Outcome and follow-up
One year after surgery, the first MTP joint showed contracture of 50° in dorsiflexion and 0° in plantar flexion. However, the patient felt no pain when walking and was able to run. Plain radiographs showed no morphological abnormalities (figure 8). Clinical evaluation revealed a score of 95 points on the Japanese Society for Surgery of the Foot Hallux Scale2 and a perfect score on the Self-Administered Foot Evaluation Questionnaire.3
Plain radiographs obtained in a weightbearing position 1 year after surgery show no morphological abnormalities: (A) anteroposterior view and (B) lateral view.
Discussion
First reported by Chisholm in 1914,4 dislocation of the first MTP joint is a rare injury of the foot with an incidence of 0.008%–0.04%.5 6 Lateral dislocations are very rare, with only nine cases reported in the literature as far as we are aware1 7–13 (table 1).
Reported cases of lateral dislocation of the first metatarsophalangeal joint
| First author | Publication year | Age, years | Situation | Associated injury | Reduction | Sesamoid complex | Operation |
| Present case | 2021 | 45 | Direct crush injury | Lisfranc joint dislocation, dislocation of the second, third and fourth TMT joints, fracture at the base of the second metatarsal | Open | Dislocation (+), fracture (−) | Capsule and ligament repair, internal fixation |
| Vosoughi1 | 2017 | 44 | Motorcycle accident | Fracture of the second, third and fourth metatarsals | Open | Dislocation (+), fracture (−) | Capsule and ligament repair |
| Chou7 | 2015 | 27 | Traffic accident | Dislocation of the second MTP joint | Open | Dislocation (+), fracture (+) | Closed reduction and internal fixation |
| Yun8 | 2008 | 38 | Fall | Avulsed bone fragment from the proximal phalanx of the great toe | Closed | Dislocation (+), fracture (−) | Ligament repair, closed reduction and internal fixation |
| Piétu9 | 2005 | 23 | Motor vehicle accident | None | Open | Dislocation (+), fracture (−) | Ligament repair, closed reduction and internal fixation |
| Piétu9 | 2005 | 25 | Direct crush injury | Fracture dislocation of the second MTP joint, dislocation of the third MTP joint | Open | Dislocation (+), fracture (−) | Ligament repair, closed reduction and internal fixation |
| Kasmaoui10 | 2003 | 28 | Traffic accident | Fracture of the neck of the second and third metatarsals, first and second Lisfranc joint dislocation | Open | Dislocation (−), fracture (−) | Closed reduction and internal fixation |
| Bousselmame 11 |
2001 | 24 | Motorcycle accident | Fracture of the head of the second metatarsal | Closed | Dislocation (+), fracture (−) | Ligament repair |
| Gale12 | 1991 | 20 | Motorcycle accident | Fracture of the neck of the second, third and fourth metatarsals | Closed | Dislocation (+), fracture (−) | Conservative treatment |
| Henderson13 | 1986 | 19 | Motorcycle accident | Interphalangeal joint dislocation in the great toe | Closed | Dislocation (−), fracture (−) | Capsule and ligament repair |
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MTP, metatarsophalangeal; TMT, tarsometatarsal.
All of the injuries in these reports were caused by high-energy trauma, such as falls or traffic accidents, as in the present case, and only one mentioned concomitant Lisfranc joint dislocation; however, there were other associated injuries, including dislocation of the first interphalangeal joint, dislocation of an MTP joint other than the great toe, or metatarsal fracture, except in one case with no associated injuries.
Furthermore, in seven cases, there was dislocation of the sesamoids, with one case that was complicated by a sesamoid fracture. The sesamoid complex consists of the plantar plate, flexor hallucis brevis, capsule and sesamoid ligaments, and plays an important support role on the basal side of the first MTP joint.14
Jahss5 15 16 classified dorsal dislocations of the MTP joint according to the rupture pattern of the sesamoid complex. When there is mild damage to the MTP joint, the dislocation causes the sesamoid complex to be displaced dorsally towards the metatarsal head and become entrapped, and this is the main factor limiting the reduction.
Zrig et al 17 also proposed a general classification for dislocations of the first MTP joint that included lateral and plantar dislocations. Large lateral dislocations may be difficult to repair due to incarceration of the sesamoid complex. Only four of the reported cases of lateral dislocation could be treated by closed reduction and five required open reduction.
In our case, the presumed mechanism of injury and pathology is as follows. Axial loading was applied with the forefoot fixed in the equinus position, and the dorsal ligament was torn and the plantar ligament was damaged because the Lisfranc joint was subjected to strong plantar flexion, after which the second to fourth TMT joints were subluxed dorsally. At the same time, the medial support structure of the first MTP joint was disrupted due to the valgus force of the great toe. However, because the plantar aspect was not severely damaged, the sesamoid complex and the flexor hallucis longus were dislocated to the lateral side of the metatarsal head and incarcerated along with the proximal phalanx. The first TMT joint was forcibly pulled down to the plantar side, resulting in plantar subluxation unlike the other toes. Open reduction was necessary to repair the dislocation of the first MTP joint, after which the force that was pulling the first TMT joint down to the plantar side disappeared and the TMT joint recovered spontaneously.
In the reported cases, the first ray was observed to be unstable even after repair, and ligament repair or Kirschner wire fixation was performed. This may reflect the fact that most of the injuries were caused by strong external forces that resulted in severe damage to the soft tissues, including the collateral ligament. However, the outcome of lateral dislocation of the MTP joint in the great toe is good in the short to medium term, with few complaints when wearing shoes and an acceptable range of motion.1 However, it has been suggested that damage to the medial soft tissues caused by lateral dislocation of the first MTP joint may cause hallux valgus,1 and complications such as osteoarthritis, neuralgia and pseudarthrosis of the sesamoids have been reported.17
In this case, we thought it was necessary to repair the dislocation as soon as possible for pain control and to avoid damage to the blood vessels, skin and nerves. Therefore, we took action on the day of the injury. However, joint instability remained even after reduction. However, the swelling was already so severe that we thought it would be better to avoid a highly invasive procedure. Furthermore, because it was difficult to determine the area to be repaired on the day of the first surgery due to the rare condition and we could not prepare sufficient surgical equipment at the time, we waited for the swelling to subside and plate fixation of the TMT joint was performed later, with addition of repair of the joint capsule and ligaments of the first MTP joint with sufficient preparation.18 19 We believe that this strategy adequately stabilised the forefoot and contributed to the good outcome in this case.
Learning points
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Most traumatic dislocations of the first metatarsophalangeal joint are in the dorsal direction, and lateral dislocations are very rare.
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If closed reduction is difficult, open reduction should be performed as soon as possible in order to control pain and avoid damage to the blood vessels, skin and nerves.
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If the joint is still unstable after reduction, strong internal fixation and further soft tissue repair should be considered.
Ethics statements
Footnotes
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Contributors KM, TK and MK had the idea of the article, wrote the manuscript and were involved in the patient's care. MS was involved in writing and review of the manuscript.
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Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
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Competing interests None declared.
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Provenance and peer review Not commissioned; externally peer reviewed.
- © BMJ Publishing Group Limited 2021. No commercial re-use. See rights and permissions. Published by BMJ.
References
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