Diaphyseal tibiofibular synostosis (plural: synostoses) is a rare condition where there is a focal bony fusion between the tibial and fibular shafts 1,2.
It is a rare condition that is reported in athletes, runners and basketball players 1.
Depending on the location, synostosis may be asymptomatic. Symptomatic synostosis usually presents with chronic anterior leg compartment pain with exertion or ankle pain.
Several causes of synostosis have been described. Congenital types may be associated with multiple hereditary exostoses and typically present at an earlier age.
Other causes include trauma, predominantly to the distal tibia and fibula and ankle where an occult stress fracture or severe ligamentous sprain of the interosseous membrane has occurred. In these cases, the synostosis is believed to result from heterotopic ossification of a small hematoma tracking between the two bones resulting in calcification on the interosseous membrane.
It appears as a focal bony fusion between the shafts of tibia and fibula. It is best appreciated by plain X-ray. There is occasionally an accompanying deformity of the limb segment.
CT and MRI are essential to differentiate this condition from a neoplastic process and to determine its relation to the neurovascular structures.
Bone scan may show increased tracer uptake 5.
Treatment and prognosis
The management of this condition in athletes is controversial. Conservative treatment is recommended initially. Ultrasound-guided steroid injection may be helpful 2. Simple surgical excision of the synostosis is reserved for active athletes with progressive pain and disability 5.
- 1. Sonnery-Cottet B, Alessio-Mazzola M, Luz BF, Barbosa NC, Tuteja S, Kajetanek C, Dellal A, Thaunat M. Diaphyseal tibiofibular synostosis in professional athletes: Report of 2 cases. (2016) Orthopaedics & traumatology, surgery & research : OTSR. 102 (1): 135-8. doi:10.1016/j.otsr.2015.10.002 - Pubmed
- 2. Kobayashi S, Miyazaki T, Takeno K, Arakawa A. Diaphyseal tibiofibular synostosis in a runner. (2013) The Journal of foot and ankle surgery : official publication of the American College of Foot and Ankle Surgeons. 52 (5): 638-42. doi:10.1053/j.jfas.2013.04.001 - Pubmed
- 3. Santa Maria DL, Shaw T, Allen M, Marin J. Fractured diaphyseal tibiofibular synostosis in an adolescent soccer player. (2015) PM & R : the journal of injury, function, and rehabilitation. 7 (1): 84-7. doi:10.1016/j.pmrj.2014.08.947 - Pubmed
- 4. Lenin Babu V, Leninbabu V, Shenbaga N, Komarasamy B, Paul A. Proximal tibiofibular synostosis as a source of ankle pain: a case report. (2006) The Iowa orthopaedic journal. 26: 127-9. Pubmed
- 5. Flandry F, Sanders RA. Tibiofibular synostosis: an unusual cause of shin splint-like pain. (1987) The American journal of sports medicine. 15 (3): 280-4. doi:10.1177/036354658701500318 - Pubmed
- 6. Munjal K, Kishan S, Sabharwal S. Posttraumatic pediatric distal tibiofibular synostosis: a case report. (2004) Foot & ankle international. 25 (6): 429-33. doi:10.1177/107110070402500613 - Pubmed