IMAGES FOR SURGEONS ANZJSurg.com
Tibial nerve palsy as the presenting feature of posterior tibial artery pseudoaneurysm Pseudoaneurysm of the posterior tibial artery has been reported infrequently in the literature. It has been seen following highenergy lower limb trauma, open fractures and iatrogenic injury. We present the case of a 16-year-old boy who presented with a persistent numbness to the sole of his foot 4-months following a closed fracture of his tibia. He underwent resection of the pseudoaneurysm and decompression of his tibial nerve. A 16-year-old boy with no previous medical history sustained a closed fracture of the mid-shaft of his right tibia following a motorcycle accident (Fig. 1). On presentation to the emergency department, he was noted to have normal pedal pulses and slightly decreased light-touch sensation in the medial and lateral plantar nerve distributions. He underwent Titanium Elastic Nail System nailing of his unstable fracture, with subsequent uneventful bony union. On examination at 6-weeks follow-up, he was noted to have a persistent, profound, loss of sensation in the sole of his foot. He also had swelling of his lower medial calf, which was assumed to be a haematoma. When no resolution of the tibial nerve palsy or the ‘haematoma’ swelling was forthcoming at 12-weeks follow-up nerve conduction studies and ultrasound examinations were requested. These revealed a 51 × 30 × 50 mm pseudoaneurysm of the posterior tibial artery and abnormal nerve conduction/electromyography with almost complete right tibial motor neuropathy. Subsequent magnetic resonance imaging showed displacement of the, in continuity, tibial nerve, and loss of muscle mass in the calf compared with the other side (Fig. 2). Further clinical examination revealed a subtle weakness in muscle power of flexor hallucis longus. The motor deficit had not been clinically apparent as his weight bearing and ambulation had been limited by his fracture rehabilitation. He underwent surgical decompression of the tibial nerve and resection of the pseudoaneurysm. Due to the chronicity of the pseudoaneurysm at the time of exploration, a large degree of fibrosis had occurred, rendering it impossible to dissect the posterior tibial artery from the pseudoaneurysm sac. Blood flow through the posterior tibial artery was minimal and the leg was well vascularized through the anterior tibial and peroneal vessels, therefore the decision was taken to ligate the posterior tibial artery to ensure the vessels feeding the pseudo aneurysm were dealt with. The thickened, fibrotic, pseudoaneurysm sac was resected from the tibial nerve, which was in continuity but markedly compressed at the site of the pseudoaneurysm (Fig. 3). On review at 3-months following nerve decompression and pseudoaneurysm excision, he reported some return of sensation to the sole of his foot. A positive Tinel’s sign was elicited in the distal © 2016 Royal Australasian College of Surgeons
leg. Further imaging or nerve conduction studies were not deemed necessary. Pseudoaneurysm of the posterior tibial artery is rare. It has been 3 reported following low-energy fracture,1,2 penetrating injury,3 ,4 5 6 surgical manipulation, tendon transfer surgery and arthroscopy.7
Fig. 1. Closed right tibia and fibula fractures with minimal displacement prior to reduction and intramedullary nailing of the tibia.
ANZ J Surg (2016)
Images for surgeons
2
Fig. 2. Coronal T1 magnetic resonance imaging showing the right sided pseudoaneurysm displacing the tibial nerve.
These lesions may be asymptomatic, presenting as a palpable lump, may present with distal embolization,8 but have been reported to cause non-union2 and even pathological fracture4 when untreated. Tibial nerve compression leading to paraesthesia, neuralgia and weakness of the foot and toe muscles has been reported as a complication of true aneurysm of the posterior tibial artery,8 but not to our knowledge as a presenting feature of pseudoaneurysm. It has been suggested that the pathophysiology of pseudoaneurysm formation involves injury to all three arterial layers, leading to subsequent haematoma formation, inflammation and local tissue degeneration. This later results in pseudoaneurysm formation.9 Treatment of pseudoaneurysm is varied, and depends on the presenting symptoms. Much debate regarding open versus endovascular repair exists. Sometimes spontaneous thrombosis of the pseudoaneurysm can occur, but intervention should be undertaken once the diagnosis is established to prevent enlargement and potential complications. Endovascular treatment options include coil embolization, ultrasound-guided compression and percutaneous injection of thrombin. However, open vascular surgery may be the only option if endovascular procedures are unsuccessful, or, as in our case, decompression of the tibial nerve is required. Vascular injuries following high-energy trauma are not uncommon. In otherwise healthy young people, however, vascular injury following long bone fracture is rare, being seen in only 0.6% of all paediatric orthopaedic trauma patients.10 Within this group, open fractures account for the vast majority of patients with concomitant vascular injury.11
Fig. 3. Intraoperative view of the pseudoaneurysm with a vessel loop isolating the tibial nerve proximally.
This case illustrates an unusual presentation of an infrequently reported complication of a closed tibia/fibula fracture. Early recognition of the unresolved ‘haematoma’ following lower limb trauma should alert one to the possibility of pseudoaneurysm formation and early intervention may be warranted to prevent compression of surrounding structures.
References 1. Guiral J, Vázquez P, Ortega M. False aneurysm of the posterior tibial artery complicating fracture of the tibia and fibula. Rev. Chir. Orthop. Reparatrice Appar. Mot. 1995; 81: 546–8. 2. Kalyan JP, Kordzadeh A, Hanif MA, Griffiths M, Lyall H, Prionidis I. Nonunion of the tibial fracture as a consequence of posterior tibial artery pseudoaneurysm. J. Surg. Case Rep. 2015; 2015: rjv138. 3. Singh D, Ferero A. Traumatic pseudoaneurysm of the posterior tibial artery treated by endovascular coil embolization. Foot Ankle Spec. 2013; 6: 54–8. 4. Singh PK, Banode P, Shrivastva S, Dulani R. Pathological fracture of the fibula due to a late presenting posterior tibial artery pseudoaneurysm: a case report. J. Bone Joint Surg. Am. 2011; 93: e54. 5. Brigido SA, Bleazey ST, Oskin TC, Protzman NM. Pseudoaneurysm of the posterior tibial artery after manipulation under anesthesia of a total ankle replacement. J. Foot Ankle Surg. 2013; 52: 655–8. 6. Elabdi M, Roukhsi R, Tijani Y, Chtata H, Jaafar A. Pseudoaneurysm of the posterior tibial artery after posterior tibial tendon transfer. J. Foot Ankle Surg. 2016; 55: 609–11. © 2016 Royal Australasian College of Surgeons
Images for surgeons
7. Salgado CJ, Mukherjee D, Quist MA, Cero S. Anterior tibial artery pseudoaneurysm after ankle arthroscopy. Cardiovasc. Surg. 1998; 6: 604–6. 8. Tshomba Y, Papa M, Marone EM, Kahlberg A, Rizzo N, Chiesa R. A true posterior tibial artery aneurysm – a case report. Vasc. Endovascular Surg. 2006; 40: 243–9. 9. Snyder LL, Binet EF, Thompson BW. False aneurysm with arteriovenous fistula of the anterior tibial artery following fracture of the fibula. Radiology 1982; 143: 405–6. 10. Barmparas G, Inaba K, Talving P et al. Pediatric vs adult vascular trauma: a National Trauma Databank review. J. Pediatr. Surg. 2010; 45: 1404–12.
© 2016 Royal Australasian College of Surgeons
3
11. Caudle RJ, Stern PJ. Severe open fractures of the tibia. J. Bone Joint Surg. Am. 1987; 69: 801–7.
Adrian D. Murphy, MD, FRCS (Plast) Marion Chan, MBBS Sian M. Fairbank, MBBS, FRACS Department of Plastic and Maxillofacial Surgery, Royal Children’s Hospital, Melbourne, Victoria, Australia doi: 10.1111/ans.13825
Tibial nerve palsy as the presenting feature of posterior tibial artery pseudoaneurysm Pseudoaneurysm of the posterior tibial artery has been reported infrequently in the literature. It has been seen following highenergy lower limb trauma, open fractures and iatrogenic injury. We present the case of a 16-year-old boy who presented with a persistent numbness to the sole of his foot 4-months following a closed fracture of his tibia. He underwent resection of the pseudoaneurysm and decompression of his tibial nerve. A 16-year-old boy with no previous medical history sustained a closed fracture of the mid-shaft of his right tibia following a motorcycle accident (Fig. 1). On presentation to the emergency department, he was noted to have normal pedal pulses and slightly decreased light-touch sensation in the medial and lateral plantar nerve distributions. He underwent Titanium Elastic Nail System nailing of his unstable fracture, with subsequent uneventful bony union. On examination at 6-weeks follow-up, he was noted to have a persistent, profound, loss of sensation in the sole of his foot. He also had swelling of his lower medial calf, which was assumed to be a haematoma. When no resolution of the tibial nerve palsy or the ‘haematoma’ swelling was forthcoming at 12-weeks follow-up nerve conduction studies and ultrasound examinations were requested. These revealed a 51 × 30 × 50 mm pseudoaneurysm of the posterior tibial artery and abnormal nerve conduction/electromyography with almost complete right tibial motor neuropathy. Subsequent magnetic resonance imaging showed displacement of the, in continuity, tibial nerve, and loss of muscle mass in the calf compared with the other side (Fig. 2). Further clinical examination revealed a subtle weakness in muscle power of flexor hallucis longus. The motor deficit had not been clinically apparent as his weight bearing and ambulation had been limited by his fracture rehabilitation. He underwent surgical decompression of the tibial nerve and resection of the pseudoaneurysm. Due to the chronicity of the pseudoaneurysm at the time of exploration, a large degree of fibrosis had occurred, rendering it impossible to dissect the posterior tibial artery from the pseudoaneurysm sac. Blood flow through the posterior tibial artery was minimal and the leg was well vascularized through the anterior tibial and peroneal vessels, therefore the decision was taken to ligate the posterior tibial artery to ensure the vessels feeding the pseudo aneurysm were dealt with. The thickened, fibrotic, pseudoaneurysm sac was resected from the tibial nerve, which was in continuity but markedly compressed at the site of the pseudoaneurysm (Fig. 3). On review at 3-months following nerve decompression and pseudoaneurysm excision, he reported some return of sensation to the sole of his foot. A positive Tinel’s sign was elicited in the distal © 2016 Royal Australasian College of Surgeons
leg. Further imaging or nerve conduction studies were not deemed necessary. Pseudoaneurysm of the posterior tibial artery is rare. It has been 3 reported following low-energy fracture,1,2 penetrating injury,3 ,4 5 6 surgical manipulation, tendon transfer surgery and arthroscopy.7
Fig. 1. Closed right tibia and fibula fractures with minimal displacement prior to reduction and intramedullary nailing of the tibia.
ANZ J Surg (2016)
Images for surgeons
2
Fig. 2. Coronal T1 magnetic resonance imaging showing the right sided pseudoaneurysm displacing the tibial nerve.
These lesions may be asymptomatic, presenting as a palpable lump, may present with distal embolization,8 but have been reported to cause non-union2 and even pathological fracture4 when untreated. Tibial nerve compression leading to paraesthesia, neuralgia and weakness of the foot and toe muscles has been reported as a complication of true aneurysm of the posterior tibial artery,8 but not to our knowledge as a presenting feature of pseudoaneurysm. It has been suggested that the pathophysiology of pseudoaneurysm formation involves injury to all three arterial layers, leading to subsequent haematoma formation, inflammation and local tissue degeneration. This later results in pseudoaneurysm formation.9 Treatment of pseudoaneurysm is varied, and depends on the presenting symptoms. Much debate regarding open versus endovascular repair exists. Sometimes spontaneous thrombosis of the pseudoaneurysm can occur, but intervention should be undertaken once the diagnosis is established to prevent enlargement and potential complications. Endovascular treatment options include coil embolization, ultrasound-guided compression and percutaneous injection of thrombin. However, open vascular surgery may be the only option if endovascular procedures are unsuccessful, or, as in our case, decompression of the tibial nerve is required. Vascular injuries following high-energy trauma are not uncommon. In otherwise healthy young people, however, vascular injury following long bone fracture is rare, being seen in only 0.6% of all paediatric orthopaedic trauma patients.10 Within this group, open fractures account for the vast majority of patients with concomitant vascular injury.11
Fig. 3. Intraoperative view of the pseudoaneurysm with a vessel loop isolating the tibial nerve proximally.
This case illustrates an unusual presentation of an infrequently reported complication of a closed tibia/fibula fracture. Early recognition of the unresolved ‘haematoma’ following lower limb trauma should alert one to the possibility of pseudoaneurysm formation and early intervention may be warranted to prevent compression of surrounding structures.
References 1. Guiral J, Vázquez P, Ortega M. False aneurysm of the posterior tibial artery complicating fracture of the tibia and fibula. Rev. Chir. Orthop. Reparatrice Appar. Mot. 1995; 81: 546–8. 2. Kalyan JP, Kordzadeh A, Hanif MA, Griffiths M, Lyall H, Prionidis I. Nonunion of the tibial fracture as a consequence of posterior tibial artery pseudoaneurysm. J. Surg. Case Rep. 2015; 2015: rjv138. 3. Singh D, Ferero A. Traumatic pseudoaneurysm of the posterior tibial artery treated by endovascular coil embolization. Foot Ankle Spec. 2013; 6: 54–8. 4. Singh PK, Banode P, Shrivastva S, Dulani R. Pathological fracture of the fibula due to a late presenting posterior tibial artery pseudoaneurysm: a case report. J. Bone Joint Surg. Am. 2011; 93: e54. 5. Brigido SA, Bleazey ST, Oskin TC, Protzman NM. Pseudoaneurysm of the posterior tibial artery after manipulation under anesthesia of a total ankle replacement. J. Foot Ankle Surg. 2013; 52: 655–8. 6. Elabdi M, Roukhsi R, Tijani Y, Chtata H, Jaafar A. Pseudoaneurysm of the posterior tibial artery after posterior tibial tendon transfer. J. Foot Ankle Surg. 2016; 55: 609–11. © 2016 Royal Australasian College of Surgeons
Images for surgeons
7. Salgado CJ, Mukherjee D, Quist MA, Cero S. Anterior tibial artery pseudoaneurysm after ankle arthroscopy. Cardiovasc. Surg. 1998; 6: 604–6. 8. Tshomba Y, Papa M, Marone EM, Kahlberg A, Rizzo N, Chiesa R. A true posterior tibial artery aneurysm – a case report. Vasc. Endovascular Surg. 2006; 40: 243–9. 9. Snyder LL, Binet EF, Thompson BW. False aneurysm with arteriovenous fistula of the anterior tibial artery following fracture of the fibula. Radiology 1982; 143: 405–6. 10. Barmparas G, Inaba K, Talving P et al. Pediatric vs adult vascular trauma: a National Trauma Databank review. J. Pediatr. Surg. 2010; 45: 1404–12.
© 2016 Royal Australasian College of Surgeons
3
11. Caudle RJ, Stern PJ. Severe open fractures of the tibia. J. Bone Joint Surg. Am. 1987; 69: 801–7.
Adrian D. Murphy, MD, FRCS (Plast) Marion Chan, MBBS Sian M. Fairbank, MBBS, FRACS Department of Plastic and Maxillofacial Surgery, Royal Children’s Hospital, Melbourne, Victoria, Australia doi: 10.1111/ans.13825
