Talus bipartitus: a systematic review and report of two cases with arthroscopic treatment

Abstract

Purpose The aim of this study was to provide a literature review on talus bipartitus and to introduce an arthroscopic treatment option.Methods A systematic review of published case reports and small case series was performed. Medline, Embase, CINAHL, Google Scholar and Web of Science databases were searched for relevant publications. In addition, three cases of talus bipartitus treated in our institute were discussed.ResultsEleven articles were identified, reporting on 23 patients, of whom one patient had a bilateral talus bipartitus. Fourteen were males (61%). The median age at presentation was 15.5 years (IQR 14–24.3). In 21 of the symptomatic cases (96%), the patient experienced ankle pain, and 13 had a restricted range of motion (54%). In our institution, two patients were treated arthroscopically and had excellent short- and long-term outcomes.ConclusionTalus bipartitus is a rare anatomical anomaly. Symptoms are characterized by pain and restricted subtalar motion in young patients. Surgical treatment is focused on either fixation or excision of the bony fragment. Our two cases have demonstrated that an arthroscopic approach can be a safe and effective treatment option in patients with a symptomatic talus bipartitus.Level of evidenceIV.

Tarsal Tunnel Syndrome Associated With a Bipartite Talus

“…By contrast, a bipartite talus will involve the posteromedial and posterolateral tubercles of the talus and appear as a much larger bony fragment, with a division occurring within the coronal plane of the talus separating it into anterior and posterior components with both segments having contributions to the articular surface of the ankle joint. 10,11 In this patient, the bone fragment was much more medial and larger than previously documented os trigonums at close to 3 cm on the axial imaging. By contrast, in a retrospective study of foot and ankle axial CT scans of 204 patients with os trigonums, the majority measured less than 1.5 cm.…”

“…7,13 Similar to TTS, the initial treatment of a symptomatic bipartite talus or os trigonum syndrome may begin conservatively with activity modification, rest, and anti-inflammatories, with progression to surgical treatment should conservative management fail. 8,[10][11][12] In this unusual case, we describe an initial TTS presentation in an older patient secondary to a large bony structure within the posterior ankle. This structure, originally thought to be a large os trigonum, was identified as a bipartite talus, which was successfully managed with tarsal tunnel decompression and removal of the posterior talar fragment.…”

“… 8 In the few reported cases, talus bipartitus has presented similar to an os trigonum with ankle pain, along with decreased range of motion and ankle swelling. 10 , 11 The etiology of a bipartite talus currently remains debated, with theories postulating it arises because of talar nonunion after trauma, repetitive trauma during development preventing secondary talar ossification center fusion, or occurs because of idiopathic failure of fusion of a secondary ossification center similar to an os trigonum. 10 - 12 Lateral radiographs are one of the most valuable modalities to visualize these bony structures, yet MRI imaging remains a vital imaging modality to assess bone marrow edema of the talus or ossicles and assess surrounding soft-tissue injury in the setting of posterior ankle pain.…”

“… 10 , 11 The etiology of a bipartite talus currently remains debated, with theories postulating it arises because of talar nonunion after trauma, repetitive trauma during development preventing secondary talar ossification center fusion, or occurs because of idiopathic failure of fusion of a secondary ossification center similar to an os trigonum. 10 - 12 Lateral radiographs are one of the most valuable modalities to visualize these bony structures, yet MRI imaging remains a vital imaging modality to assess bone marrow edema of the talus or ossicles and assess surrounding soft-tissue injury in the setting of posterior ankle pain. 7 , 13 Similar to TTS, the initial treatment of a symptomatic bipartite talus or os trigonum syndrome may begin conservatively with activity modification, rest, and anti-inflammatories, with progression to surgical treatment should conservative management fail.…”

Talus Bipartitus: A Rare Anatomical Variant Presenting as an Entrapment Neuropathy of the Tibial Nerve within the Tarsal Tunnel

“…Differential diagnosis of TB includes the presence of an os trigonum, which lacks of articular surface and has a higher incidence (13%). Zwiers et al [ 18 ] identified only 23 reported cases of TB in their systematic review. None of them involved neuropathy entrapment.…”