CASE 2236 Published on 07.09.2003

Traumatic synostosis of tibia and fibula


Musculoskeletal system

Case Type

Clinical Cases


Kumar G, Iyengar K, Murali SR.


17 years, male

Clinical History
The patient sustained a closed fracture of the distal shaft of tibia and fibula which was fixed with an interlocking nail. At six months post surgery patient was asymptomatic but the radiographs showed...
Imaging Findings
The patient came off a motor bike at about 40 miles per hour. His only injury was to the left lower leg. There was no distal neurovascular deficit. The patient did not have any significant past illnesses. Radiographs of the left lower leg showed an oblique fracture of the left distal tibial shaft and a transverse fracture of the distal third fibula with 50% lateral translation and shortening of about 1 cm (Fig 1). After administering adequate analgesia an above knee gutter slab was applied (Fig 2). Under general anaesthesia a closed reamed interlocking nail fixation was performed (Fig 3). There were no immediate post operative complications. Patient was mobilised partial weight bearing by two weeks and fully weight bearing by five weeks. At six months follow up patient was pain free and back to work as a ware house worker. The range of movements in both knee and ankle were satisfactory. Radiographs of his left tibia showed an intact nail, well healed fracture and a significant synostosis of the tibia and fibula (Fig 4). Since the patient was asymptomatic no further intervention was carried out and he was advised to return to the clinic in case of any further problems.
Superior tibio fibular joint is a synovial joint while the distal tibio fibular joint is a syndesmosis. There is minimal relative movement between the tibia and fibula. The superior articular surface of the talus is broader in front. Hence, in dorsiflexion, greater space is required between the two malleoli which is produced by a slight outward gliding movement of the distal fibula. Heterotopic bone formation between tibia and fibula is usually following injury to the syndesmosis unlike the case described here.
When an injury involves fractures of both tibia and fibula or radius and ulna shafts depending on the amount of associated soft tissue injury there is potential for synostosis. If synostosis occurs between radius and ulna the functional implications are immense whereas traumatic synostosis between tibia and fibula is not that significant due to lack of relative motion between tibia and fibula [1].
Though atraumatic synostosis of tibia and fibula is quite often associated with multiple osteochondromatosis and deformities of the involved bones there have been anecdotal reports without such associations [2]. If the synostosis interferes with the movements of the ankle then excision may be beneficial [3]. Overall there is not much of disability following synostosis of tibia and fibula.
Differential Diagnosis List
Traumatic synostosis of tibia and fibula
Final Diagnosis
Traumatic synostosis of tibia and fibula
Case information
DOI: 10.1594/EURORAD/CASE.2236
ISSN: 1563-4086