Available online at
ScienceDirect www.sciencedirect.com Chirurgie de la main 34 (2015) 91–93
Clinical case
Floating thumb metacarpal in a motorcyclist: A case report Premier métacarpien flottant chez un motocycliste : à propos d’un cas T. Messaoudi *, M. Errhaimini, M. Ghoubach, R. Chafik, M. Madhar, H. Elhaoury, H. Saidi, T. Fikry Service de traumatologie-orthopédie, CHU Mohammed VI, Marrakech, Morocco Received 25 September 2014; received in revised form 18 December 2014; accepted 7 January 2015 Available online 10 March 2015
Abstract We present a case of simultaneous dislocation of the carpometacarpal and the metacarpophalangeal joints of the thumb (floating thumb metacarpal) in a 47-year-old motorcyclist. The treatment consisted of closed reduction of both joints with cast immobilization. After 24 months, the functional result was excellent. The mechanism of this rare injury and its therapeutic management are discussed. # 2015 Elsevier Masson SAS. All rights reserved. Keywords: Dislocation; Carpometacarpal; Metacarpophalangeal; Thumb; Closed reduction
Résumé Les auteurs rapportent l’association d’une luxation simultanée des articulations trapézo-métacarpienne et métacarpo-phalangienne du pouce (premier métacarpien flottant) chez un motocycliste de 47 ans. Le traitement a consisté en une réduction orthopédique des deux articulations avec immobilisation plâtrée. Au recul de 24 mois, le résultat fonctionnel était excellent. Le mécanisme lésionnel et les modalités de prise en charge thérapeutique de cette lésion rare sont discutés. # 2015 Elsevier Masson SAS. Tous droits réservés. Mots clés : Luxation ; Trapézo-métacarpienne ; Métacarpo-phalangienne ; Pouce ; Réduction orthopédique
1. Introduction Combined dislocation of carpometacarpal (CMC) and metacarpophalangeal (MCP) joints of the thumb (floating thumb metacarpal) is a rare injury. Only a few cases have been reported in literature. We report on the conservative treatment of a simultaneous dislocation of thumb CMC and MCP joints. 2. Case report A 47-year-old right-handed man with no previous history of dislocation or joint laxity visited our emergency room after a * Corresponding author. E-mail address: [email protected] (T. Messaoudi). http://dx.doi.org/10.1016/j.main.2015.01.007 1297-3203/# 2015 Elsevier Masson SAS. All rights reserved.
road accident (motorcyclist who hit a car) in which he landed on his right thumb. Physical examination revealed pain and oedema at the thenar eminence and a zigzag deformity of the right thumb. Capillary filling and sensation in the right thumb were adequate. Radiographs showed lateral dislocation of the CMC joint and dorsal dislocation of the MCP joint without fracture (Fig. 1). Under regional anesthesia, both dislocations were reduced. The quality of the reductions was confirmed by fluoroscopy. The MCP joint was perfectly stable upon testing. The CMC joint had slight radial laxity. The possibility of surgical stabilization was discussed with the patient but he refused. As a consequence, the injury site was immobilized in a thumb spica cast for a period of six weeks, after which the radiographs were normal (Fig. 2).
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T. Messaoudi et al. / Chirurgie de la main 34 (2015) 91–93
and was very satisfied with the functional outcome. The thumb’s range of motion and the grip force were identical to those of the uninjured contralateral side. Kapandji score was 10/10. 3. Discussion
Fig. 1. Anteroposterior and lateral radiographs of the right thumb showing simultaneous dislocation of the carpometacarpal and metacarpophalangeal joints.
The patient underwent progressive physical therapy for 3 months. The patient returned to work in the same occupation after 6 months. He returned to motorcycling 10 months after the accident. After 24 months, the patient had no pain or instability,
Fig. 2. Anteroposterior and lateral radiographs of the injured thumb at 6 weeks follow-up showing well-maintained reduction of both dislocations.
Simultaneous double thumb dislocation seems to be a very rare injury [1–6]; it was first described by Moore in 1978 and later named ‘‘floating thumb metacarpal’’ by Drosos et al. [2]. Direct impact of the motorcycle handlebar into the first web space seems to be the cause of the CMC dislocation. Motorcycle riders always grip the handlebar with their fingers above and the thumb below. In a collision, the motorcycle’s abrupt stop compresses the soft tissues against the ulnar side of the base of the thumb metacarpal, causing dorsal or dorsoradial CMC joint dislocation [3]. Then, the weight of the motorcycle is transmitted through the handlebar on the palmar surface of the proximal phalanx of the thumb, causing a hyperextension force that leads to MCP dislocation (Fig. 3). In previously reported cases and in the case described here, the dislocated MCP joints were reduced easily. The integrity of the collateral ligaments should be checked, especially in cases of dorsoradial dislocation that increases the risk of collateral instability, unlike pure dorsal dislocations [2]. Although the MCP joint dislocation was dorsoradial in our reported case, the joint was perfectly stable after reduction. According Rochet et al., the position of sesamoid during stress radiographs helps to determine the surgical indication in case of MCP joint
Fig. 3. Mechanism of injury for the floating thumb metacarpal.
T. Messaoudi et al. / Chirurgie de la main 34 (2015) 91–93
instability [7]. Surgical repair should be performed only in patients who have lost the parallelism of the sesamoids relative to the tangent to the metacarpal head; this indicates a tear of two fascicles (principal and accessory) of the ulnar collateral ligament [7]. If closed reduction fails, the volar plate, sesamoid bones, or flexor pollicis longus tendon are likely interposed [8,9]. In this case, open reduction is required through a volar or dorsal approach [10,11]. Pure CMC dislocations are rare [3,11] and may go unnoticed especially in multitrauma patients [2,12]. Their treatment is very controversial. In stable closed reductions, some suggest conservative treatment with cast immobilization to maintain the reduction, but there is a risk of long-term instability [1,3–11]. Other authors prefer Kirschner-wire stabilization independent of the reduction method [2,3,12,13]. It is a quick, simple and reproducible procedure [14]; however, articular non-congruence may persist, which can generate osteoarthritis. Other authors consider that the two aforementioned treatments increase the risk of recurrence, thus ligament reconstruction [16,17] or CMC joint capsulorraphy is suggested [18]. According to Péquignot et al., peripheral ligament reconstruction provides joint stability without reducing its range of motion and results in good joint kinematics [15]. However, the outcomes have been reported to deteriorate over time [14]. When the metacarpal cannot be reduced properly, surgical treatment finds its place because of soft tissue impingement [1]. Closed reduction of the CMC joint dislocations (cast immobilization and percutaneous K-wires) can increase the risk of recurrence, due to the CMC joint instability that is secondary to joint hypermobility syndrome brought on by certain connective tissue diseases (Ehlers Danlos, Marfan, etc.) in patients with previously unidentified hyperlaxity [1]. In our case, joint testing after CMC joint reduction showed slight lateral laxity. We opted for conservative treatment because the patient refused surgery. 4. Conclusion The floating thumb metacarpal is a very rare injury that results from high-energy trauma to the thumb. Its mechanism of injury is unique. Conservative treatment is rarely described for these injuries because of the high risk of instability, but stable reduction and good functional outcome was achieved in the case reported here.
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Disclosure of interest The authors declare that they have no conflicts of interest concerning this article. References [1] Leiber-Wackenheim F, David E, Tran Van F, Havet E, Vernois J, Mertl P. Premier métacarpien flottant avec luxation trapézo métacarpienne récidivante chez un sujet hyperlaxe. Rev Chir Orthop Reparatrice Appar Mot 2007;93:725–9. [2] Drosos GI, Kayias EH, Tsioros K. Floating thumb metacarpal or complete dislocation of the thumb metacarpal a case report and review of the literature. Injury 2004;35:545–8. [3] Shih KS, Tsai WF, Wu CJ, Mudgal C. Simultaneous dislocation of the carpometacarpal and metacarpophalangeal joints of the thumb in a motorcyclist. J Formos Med Assoc 2006;105:670–3. [4] Vashista GN, Krishnan KM, Deshmukh SC. Simultaneous dislocations of the carpometacarpal and metacarpophalangeal joints of the thumb. Injury Extra 2004;35:56–8. [5] Moore JR, Webb Jr CA, Thompson RC. A complete dislocation of the thumb metacarpal. J Hand Surg Am 1978;3:547–9. [6] Ibrahim S, Noor MA. Simultaneous dislocation of the carpometacarpal and metacarpophalangeal joints of the thumb. Injury 1993;24:343–4. [7] Rochet S, Gallinet D, Garbuio P, Tropet Y, Obert L. Entorse grave du pouce : opérer selon la position des sésamoïdes lors des clichés en stress. Chir Main 2007;26:200–5. [8] Bohart PG, Gelberman RH, Vandell RF, Salamon PB. Complex dislocations of the metacarpophalangeal joint. Clin Orthop Relat Res 1982;164:208–10. [9] Dutton RO, Meals RA. Complex dorsal dislocation of the thumb metacarpophalangeal joint. Clin Orthop 1982;164:160–4. [10] Ostrowski DM. Irreducible dorsoulnar dislocation of the proximal phalanx of the thumb. J Hand Surg Am 1991;16:121–4. [11] Dray GJ, Eaton RG. Dislocations and ligament injuries in the digits. Oper Hand Surg 1993;1:767–98. [12] Johnson SR, Jones DG, Hoddinott HC. Missed carpometacarpal dislocation of the thumb in motorcyclists. Injury 1987;18:415–6. [13] Le Nen D, Hu W, Dubrana F, Prud’homme M, Genestet M, Lefèvre C. Fractures, entorses et luxations de la main et des doigts. EMC Appareil Locomoteur, 2003 [14-047-C-10]. [14] Obert L, Garbuio P, Gérard F, Ridoux PE, Tropet Y, Vichard P. La luxation trapézo-métacarpienne fermée, récente, traitée par embrochage. Ann Chir Main 1997;16:102–10. [15] Péquignot JP, Giordano P, Boatier C, Allieu Y. Luxation traumatique de la trapézo-métacarpienne. Ann Chir Main 1988;7:14–24. [16] Simonian PT, Trumble TE. Traumatic dislocation of the thumb carpometacarpal joint: early ligamentous reconstruction versus closed reduction and pinning. J Hand Surg Am 1996;21:802–6. [17] Chen VT. Dislocation of the carpometacarpal joint of the thumb. J Hand Surg Br 1987;12:246–51. [18] Gunther SF. The carpometacarpal joints. Orthop Clin North Am 1984;15: 268–77.
ScienceDirect www.sciencedirect.com Chirurgie de la main 34 (2015) 91–93
Clinical case
Floating thumb metacarpal in a motorcyclist: A case report Premier métacarpien flottant chez un motocycliste : à propos d’un cas T. Messaoudi *, M. Errhaimini, M. Ghoubach, R. Chafik, M. Madhar, H. Elhaoury, H. Saidi, T. Fikry Service de traumatologie-orthopédie, CHU Mohammed VI, Marrakech, Morocco Received 25 September 2014; received in revised form 18 December 2014; accepted 7 January 2015 Available online 10 March 2015
Abstract We present a case of simultaneous dislocation of the carpometacarpal and the metacarpophalangeal joints of the thumb (floating thumb metacarpal) in a 47-year-old motorcyclist. The treatment consisted of closed reduction of both joints with cast immobilization. After 24 months, the functional result was excellent. The mechanism of this rare injury and its therapeutic management are discussed. # 2015 Elsevier Masson SAS. All rights reserved. Keywords: Dislocation; Carpometacarpal; Metacarpophalangeal; Thumb; Closed reduction
Résumé Les auteurs rapportent l’association d’une luxation simultanée des articulations trapézo-métacarpienne et métacarpo-phalangienne du pouce (premier métacarpien flottant) chez un motocycliste de 47 ans. Le traitement a consisté en une réduction orthopédique des deux articulations avec immobilisation plâtrée. Au recul de 24 mois, le résultat fonctionnel était excellent. Le mécanisme lésionnel et les modalités de prise en charge thérapeutique de cette lésion rare sont discutés. # 2015 Elsevier Masson SAS. Tous droits réservés. Mots clés : Luxation ; Trapézo-métacarpienne ; Métacarpo-phalangienne ; Pouce ; Réduction orthopédique
1. Introduction Combined dislocation of carpometacarpal (CMC) and metacarpophalangeal (MCP) joints of the thumb (floating thumb metacarpal) is a rare injury. Only a few cases have been reported in literature. We report on the conservative treatment of a simultaneous dislocation of thumb CMC and MCP joints. 2. Case report A 47-year-old right-handed man with no previous history of dislocation or joint laxity visited our emergency room after a * Corresponding author. E-mail address: [email protected] (T. Messaoudi). http://dx.doi.org/10.1016/j.main.2015.01.007 1297-3203/# 2015 Elsevier Masson SAS. All rights reserved.
road accident (motorcyclist who hit a car) in which he landed on his right thumb. Physical examination revealed pain and oedema at the thenar eminence and a zigzag deformity of the right thumb. Capillary filling and sensation in the right thumb were adequate. Radiographs showed lateral dislocation of the CMC joint and dorsal dislocation of the MCP joint without fracture (Fig. 1). Under regional anesthesia, both dislocations were reduced. The quality of the reductions was confirmed by fluoroscopy. The MCP joint was perfectly stable upon testing. The CMC joint had slight radial laxity. The possibility of surgical stabilization was discussed with the patient but he refused. As a consequence, the injury site was immobilized in a thumb spica cast for a period of six weeks, after which the radiographs were normal (Fig. 2).
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T. Messaoudi et al. / Chirurgie de la main 34 (2015) 91–93
and was very satisfied with the functional outcome. The thumb’s range of motion and the grip force were identical to those of the uninjured contralateral side. Kapandji score was 10/10. 3. Discussion
Fig. 1. Anteroposterior and lateral radiographs of the right thumb showing simultaneous dislocation of the carpometacarpal and metacarpophalangeal joints.
The patient underwent progressive physical therapy for 3 months. The patient returned to work in the same occupation after 6 months. He returned to motorcycling 10 months after the accident. After 24 months, the patient had no pain or instability,
Fig. 2. Anteroposterior and lateral radiographs of the injured thumb at 6 weeks follow-up showing well-maintained reduction of both dislocations.
Simultaneous double thumb dislocation seems to be a very rare injury [1–6]; it was first described by Moore in 1978 and later named ‘‘floating thumb metacarpal’’ by Drosos et al. [2]. Direct impact of the motorcycle handlebar into the first web space seems to be the cause of the CMC dislocation. Motorcycle riders always grip the handlebar with their fingers above and the thumb below. In a collision, the motorcycle’s abrupt stop compresses the soft tissues against the ulnar side of the base of the thumb metacarpal, causing dorsal or dorsoradial CMC joint dislocation [3]. Then, the weight of the motorcycle is transmitted through the handlebar on the palmar surface of the proximal phalanx of the thumb, causing a hyperextension force that leads to MCP dislocation (Fig. 3). In previously reported cases and in the case described here, the dislocated MCP joints were reduced easily. The integrity of the collateral ligaments should be checked, especially in cases of dorsoradial dislocation that increases the risk of collateral instability, unlike pure dorsal dislocations [2]. Although the MCP joint dislocation was dorsoradial in our reported case, the joint was perfectly stable after reduction. According Rochet et al., the position of sesamoid during stress radiographs helps to determine the surgical indication in case of MCP joint
Fig. 3. Mechanism of injury for the floating thumb metacarpal.
T. Messaoudi et al. / Chirurgie de la main 34 (2015) 91–93
instability [7]. Surgical repair should be performed only in patients who have lost the parallelism of the sesamoids relative to the tangent to the metacarpal head; this indicates a tear of two fascicles (principal and accessory) of the ulnar collateral ligament [7]. If closed reduction fails, the volar plate, sesamoid bones, or flexor pollicis longus tendon are likely interposed [8,9]. In this case, open reduction is required through a volar or dorsal approach [10,11]. Pure CMC dislocations are rare [3,11] and may go unnoticed especially in multitrauma patients [2,12]. Their treatment is very controversial. In stable closed reductions, some suggest conservative treatment with cast immobilization to maintain the reduction, but there is a risk of long-term instability [1,3–11]. Other authors prefer Kirschner-wire stabilization independent of the reduction method [2,3,12,13]. It is a quick, simple and reproducible procedure [14]; however, articular non-congruence may persist, which can generate osteoarthritis. Other authors consider that the two aforementioned treatments increase the risk of recurrence, thus ligament reconstruction [16,17] or CMC joint capsulorraphy is suggested [18]. According to Péquignot et al., peripheral ligament reconstruction provides joint stability without reducing its range of motion and results in good joint kinematics [15]. However, the outcomes have been reported to deteriorate over time [14]. When the metacarpal cannot be reduced properly, surgical treatment finds its place because of soft tissue impingement [1]. Closed reduction of the CMC joint dislocations (cast immobilization and percutaneous K-wires) can increase the risk of recurrence, due to the CMC joint instability that is secondary to joint hypermobility syndrome brought on by certain connective tissue diseases (Ehlers Danlos, Marfan, etc.) in patients with previously unidentified hyperlaxity [1]. In our case, joint testing after CMC joint reduction showed slight lateral laxity. We opted for conservative treatment because the patient refused surgery. 4. Conclusion The floating thumb metacarpal is a very rare injury that results from high-energy trauma to the thumb. Its mechanism of injury is unique. Conservative treatment is rarely described for these injuries because of the high risk of instability, but stable reduction and good functional outcome was achieved in the case reported here.
93
Disclosure of interest The authors declare that they have no conflicts of interest concerning this article. References [1] Leiber-Wackenheim F, David E, Tran Van F, Havet E, Vernois J, Mertl P. Premier métacarpien flottant avec luxation trapézo métacarpienne récidivante chez un sujet hyperlaxe. Rev Chir Orthop Reparatrice Appar Mot 2007;93:725–9. [2] Drosos GI, Kayias EH, Tsioros K. Floating thumb metacarpal or complete dislocation of the thumb metacarpal a case report and review of the literature. Injury 2004;35:545–8. [3] Shih KS, Tsai WF, Wu CJ, Mudgal C. Simultaneous dislocation of the carpometacarpal and metacarpophalangeal joints of the thumb in a motorcyclist. J Formos Med Assoc 2006;105:670–3. [4] Vashista GN, Krishnan KM, Deshmukh SC. Simultaneous dislocations of the carpometacarpal and metacarpophalangeal joints of the thumb. Injury Extra 2004;35:56–8. [5] Moore JR, Webb Jr CA, Thompson RC. A complete dislocation of the thumb metacarpal. J Hand Surg Am 1978;3:547–9. [6] Ibrahim S, Noor MA. Simultaneous dislocation of the carpometacarpal and metacarpophalangeal joints of the thumb. Injury 1993;24:343–4. [7] Rochet S, Gallinet D, Garbuio P, Tropet Y, Obert L. Entorse grave du pouce : opérer selon la position des sésamoïdes lors des clichés en stress. Chir Main 2007;26:200–5. [8] Bohart PG, Gelberman RH, Vandell RF, Salamon PB. Complex dislocations of the metacarpophalangeal joint. Clin Orthop Relat Res 1982;164:208–10. [9] Dutton RO, Meals RA. Complex dorsal dislocation of the thumb metacarpophalangeal joint. Clin Orthop 1982;164:160–4. [10] Ostrowski DM. Irreducible dorsoulnar dislocation of the proximal phalanx of the thumb. J Hand Surg Am 1991;16:121–4. [11] Dray GJ, Eaton RG. Dislocations and ligament injuries in the digits. Oper Hand Surg 1993;1:767–98. [12] Johnson SR, Jones DG, Hoddinott HC. Missed carpometacarpal dislocation of the thumb in motorcyclists. Injury 1987;18:415–6. [13] Le Nen D, Hu W, Dubrana F, Prud’homme M, Genestet M, Lefèvre C. Fractures, entorses et luxations de la main et des doigts. EMC Appareil Locomoteur, 2003 [14-047-C-10]. [14] Obert L, Garbuio P, Gérard F, Ridoux PE, Tropet Y, Vichard P. La luxation trapézo-métacarpienne fermée, récente, traitée par embrochage. Ann Chir Main 1997;16:102–10. [15] Péquignot JP, Giordano P, Boatier C, Allieu Y. Luxation traumatique de la trapézo-métacarpienne. Ann Chir Main 1988;7:14–24. [16] Simonian PT, Trumble TE. Traumatic dislocation of the thumb carpometacarpal joint: early ligamentous reconstruction versus closed reduction and pinning. J Hand Surg Am 1996;21:802–6. [17] Chen VT. Dislocation of the carpometacarpal joint of the thumb. J Hand Surg Br 1987;12:246–51. [18] Gunther SF. The carpometacarpal joints. Orthop Clin North Am 1984;15: 268–77.
