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...
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.
Traumatic synostosis of tibia and fibula
Based on the provided X-ray images, the distal tibia and distal fibula after external fixation (intramedullary nail) show that the fracture line is essentially healed and the fixation remains stable.
A clear bony bridging can be observed between the tibia and fibula, indicating potential ossification or bony connection (possibly ectopic ossification or bony bridging).
The fracture fragments are in acceptable alignment, and the distal articular surface is basically flat without noticeable collapse or displacement. No obvious swelling or abnormal density is seen in the surrounding soft tissues.
Overall, there is no evidence of delayed union or nonunion, and the bone quality around the fixation device appears normal.
Taking into account the patient’s age (17), clinical information (closed distal tibia and fibula fracture, 6 months post-surgery with no significant clinical symptoms), and imaging findings (bony bridging between the tibia and fibula), the most likely diagnosis is:
Post-traumatic (post-surgical) Tibiofibular Synostosis
Because the normal range of motion between the tibia and fibula is relatively limited, a mild bony synostosis usually does not significantly affect lower limb function. However, further evaluation and management may be required should ankle range of motion become restricted or other functional issues arise in the future.
Given the limited physiological movement between the tibia and fibula, most patients with mild tibiofibular synostosis do not require additional surgical intervention in the absence of notable functional impairment or pain. Regular follow-up is recommended, and vigilance is advised in case of:
• Unexplained localized pain or swelling.
• Marked restriction in ankle mobility that compromises normal gait.
• Loosening of fixation or re-displacement of the bone.
The following rehabilitation exercises and exercise prescriptions can be implemented to maintain and progressively improve lower limb range of motion and muscle strength:
If significant restriction of ankle mobility arises in the future, impacting quality of life, surgical removal of the bony bridge may be considered following specialist evaluation. However, this scenario is relatively uncommon, and such intervention is typically reserved for cases unresponsive to conservative treatment or where clear functional limitations exist.
Disclaimer: This report is based solely on the provided images and clinical information for reference and does not replace in-person consultation or professional medical advice. If necessary, please seek medical attention or consult a specialist for a personalized treatment plan.
Traumatic synostosis of tibia and fibula
