Bipartite os tibiale externum: A rare condition causing foot pain

BackgroundThe accessory navicular (os tibiale externum, prehallux) is a frequent skeletal variation. However, a bipartite os tibiale externum is extremely rare and so far has only be reported in radiologic studies.MethodsWe report on a 30-year old female patient with flexible flatfoot and a bilateral accessory navicular. On the more painful side, a bipartite accessory navicular was resected. The posterior tibial tendon was fixed to the medial aspect of the navicular proper after levelling the prominent tuberosity.Results and conclusionsThe patient was completely pain free after 6 weeks and there was no remaining functional deficit. Bipartite accessory navicular is a very rare variant of a rather frequent accessory bone at the foot. Resection of the ossicle with debridement of the medial aspect of the navicular and attachment of the posterior tibial tendon to the navicular body (modified Kidner procedure) seems to lead to an excellent result also in these cases. In the presence of more severe deformities, treatment has to be adapted to the individual case.     

Approach and treatment of the adult acquired flatfoot deformity

Adult acquired flatfoot deformity (AAFD), embraces a wide spectrum of deformities. AAFD is a complex pathology consisting both of posterior tibial tendon insufficiency and failure of the capsular and ligamentous structures of the foot. Each patient presents with characteristic deformities across the involved joints, requiring individualized treatment. Early stages may respond well to aggressive conservative management, yet more severe AAFD necessitates prompt surgical therapy to halt the progression of the disease to stages requiring more complex procedures. We present the most current diagnostic and therapeutic approaches to AAFD, based on the most pertinent literature and our own experience and investigations.     

Arthrodesis for chronic lateral subtalar joint dislocation caused by posterior tibial tendon dysfunction: A case report

IntroductionAdult acquired flatfoot deformity (AAFD) caused by posterior tibial tendon dysfunction (PTTD) can lead to the development of peritalar subluxation (PTS) and much more rarely to lateral subtalar dislocation.Presentation of caseA 75-year-old woman was referred to our hospital with an approximately 15-year history of pain in her right foot without obvious trauma. The lateral shifting foot deformity had worsened in the previous 5 years. On presentation, she had tenderness over the talonavicular joint, and the skin overlying the talar head on the medial foot was taut. Imaging revealed lateral displacement of the calcaneus with simultaneous dislocation of the talonavicular and talocalcaneal joints. We diagnosed lateral subtalar dislocation including the talonavicular and talocalcaneal joints caused by PTTD, which we treated by reduction and fusion of the subtalar joint complex. The foot and ankle were immobilized with a cast for 6 weeks.DiscussionAt the 1-year follow-up visit, the patient reported no pain during daily activities, although flatfoot persisted.ConclusionWe report a rare case of chronic lateral subtalar dislocation caused by PTTD that was treated by fusion of the talonavicular and talocalcaneal joints.     

Combined weightbearing CT and MRI assessment of flexible progressive collapsing foot deformity

BackgroundThe objective of this study was to evaluate the correlation between Weightbearing CT (WBCT) markers of pronounced peritalar subluxation (PTS) and MRI findings of soft tissue insufficiency in patients with flexible Progressive Collapsing Foot Deformity (PCFD). We hypothesized that significant correlation would be found.MethodsRetrospective comparative study with 54 flexible PCFD patients. WBCT and MRI variables deformity severity were evaluated, including markers of pronounced PTS, as well as soft tissue degeneration. A multiple regression analysis and partition prediction models were used to evaluate the relationship between bone alignment and soft tissue injury. P-values of less than .05 were considered significant.ResultsDegeneration of the posterior tibial tendon was significantly associated with sinus tarsi impingement (p = .04). Spring ligament degeneration correlated to subtalar joint subluxation (p = .04). Talocalcaneal interosseous ligament involvement was the only one to significantly correlate to the presence of subfibular impingement (p = .02).ConclusionOur results demonstrated that WBCT markers of pronounced deformity and PTS were significantly correlated to MRI involvement of the PTT and other important restraints such as the spring and talocalcaneal interosseus ligaments.LEVEL OF EVIDENCE: Level III, Retrospective comparative study.