Talar Neck Fractures…Tickle the Foot! (Well, Test Sensation)
by Elizabeth Hofheinz, M.P.H., M.Ed.
Citing that talus fractures are accompanied by a high rate of complications, including numbness, pain, and tingling, researchers from the Medical College of Georgia and the Emory University School of Medicine joined forces to conduct a retrospective chart review on these injuries. Their work, “Tibial Nerve Dysfunction Associated With Operatively Treated Talar Neck Fractures,” was published in the September 2020 edition of The Journal of Orthopaedic Trauma.
Co-author Thomas Moore, Jr., M.D. commented to OSN, “I work at a level 1 trauma center, Grady Memorial Hospital in Atlanta, where we see a lot of high energy lower extremity trauma. We already know the other common associated injuries with talar neck fractures such as ankle arthritis, avascular necrosis, subtalar arthritis, and malunion. We also commonly see neurologic injuries involving the tibial nerve with these high energy injuries, but no one had previously characterized how often this occurs and when. There also wasn’t a lot of literature on the natural history of these nerve injuries, which are commonly treated with observation.”
The researchers examined 64 patients (65 talar neck fractures) who underwent open reduction and internal fixation between January 1, 2014, and May 1, 2018. The Hawkins classification system for characterizing talar neck fractures was used, as was the Orthopaedic Trauma Association/AO classification system.
“We looked at our hospital trauma database and found all operative talar neck fractures and looked for tibial nerve dysfunction and found associations with the type of fracture and type of displacement present in the hindfoot,” recounted Dr. Moore. “The higher the grade on the Hawkins classification, which also correlates with other complications of talar neck fracture, the more likely the patient will have tibial nerve dysfunction. We also found an association between open fracture of the talus and tibial nerve dysfunction and an association between tibiotalar dislocation and tibial nerve dysfunction.”
The authors wrote, “Evidence of TND was documented in 20 of 65 cases (30.8%) of talar neck fractures. There were no cases of TND associated with Hawkins I fractures, but TND was found in 7 of 32 Hawkins II fractures (21.9%), 10 of 24 Hawkins III fractures (41.7%), and 3 of 5 Hawkins IV fractures (60%). TND was reported in 11 of 19 open talar neck fractures (57.9%). TND was associated with tibiotalar dislocation but not subtalar dislocation. TND did not occur in the absence of subtalar subluxation/dislocation…”
“An interesting finding from our research,” states Dr. Moore, “was that half of the patients with tibial nerve dysfunction were diagnosed after surgery, some even after their initial hospitalization, which is likely due to the high rate of concomitant injuries making the initial physical exam difficult in these patients and also plantar foot and heel sensation is hard to test after a splint is placed. This finding could also be because providers don’t always actively look for this injury. We as practitioners need to be more vigilant about testing sensation on the bottom of the foot and heel in patients with talar neck fractures patients, when possible.”
“Surprisingly, the majority of these patient had at least partial (44%), if not full recovery (39%), of symptoms by 12 months postop.”