Coronal Hindfoot Alignment in Midfoot Charcot Neuroarthropathy.

Coronal plane hindfoot malalignment produces abnormal compensatory forces within the midfoot and forefoot. The primary aim of this study is to compare radiographic hindfoot alignment in patients with a midfoot Charcot event, and identify patterns associated with breakdown. A retrospective review of 43 patients (48 limbs) with midfoot Charcot neuroarthropathy were compared between the coronal hindfoot alignments and Charcot joint involvement. Coronal hindfoot alignment was classified as neutral (n = 15), valgus (n = 16), and varus (n = 17) utilizing the Saltzman hindfoot alignment radiograph. Charcot joint breakdown was classified as isolated tarsometatarsal joint (n = 8), combination of tarsometatarsal and naviculocuneiform joints (n = 22), and midtarsal joints including talonavicular and calcaneocuboid joints (n = 18). Patients exhibiting varus hindfoot alignment had 5.8 times greater risk of breakdown at the tarsometatarsal and naviculocuneiform joints (odds ratio 5.8, 95% confidence interval 1.7-22.9, p < .01). Hindfoot varus induces external rotation of the talus, resulting in compensation through the naviculocuneiform and tarsometatarsal joint, which correlates with our findings of a 6-fold increase in naviculocuneiform and tarsometatarsal joint collapse. Patients exhibiting valgus hindfoot alignment had 27 times greater risk of breakdown at the midtarsal joint (odds ratio 27.0; 95% confidence interval 5.6-207.0, p < .01). Hindfoot valgus induces internal rotation of the talonavicular joint, which correlates with our findings of a 27-fold increase in midtarsal joint breakdown. Varus and valgus hindfoot alignment are associated with different midfoot injury patterns, which may have implications in surgical management and allow for focused surveillance in neuropathic patients presenting with early-stage clinical findings consistent with Charcot neuroarthropathy.

Risk Factors and Outcomes After Surgical Reconstruction of Charcot Neuroarthropathy in Fracture Versus Dislocation Patterns.

The primary aim of this study is to compare the preoperative risk factors and postoperative outcomes between Charcot neuroarthropathy patients with dislocation versus purely fracture pattern breakdown. The secondary aim is to compare the same factors between Charcot neuroarthropathy patients with dislocation versus fracture-dislocation pattern breakdown. A total of 55 patients with forefoot, midfoot, or hindfoot Charcot Neuroarthopathy were assessed at a mean follow up of 2.99 years. Bivariate analysis compared preoperative risk factors and postoperative outcomes, and segmented multivariable regression analysis was performed. Dislocation pattern Charcot had statistically significant higher rates of broken hardware (p = .05), mean age (p = .01), and revisional exostectomy (p = .01) compared to pure fracture pattern Charcot. Dislocation pattern Charcot was 12 times more likely to have revisions exostectomy (odds ratio [OR] 12.0, 95% confidence interval [CI] 1.84-78.37), and was 8 times more likely to have osteomyelitis (OR 7.8, 95% CI 1.4-42.7, p = .02) compared to the fracture-dislocation pattern Charcot. The patients with pure fracture pattern Charcot were 58.8 times more likely to have Charcot breakdown involvement of the talonavicular joint compared to the dislocation pattern cohort (OR 58.83, 95% CI 1.1-3220.3). Involvement of the talonavicular joint, in the fracture pattern Charcot associate with medial column collapse occurring at the onset of Charcot breakdown. The dislocation pattern in Charcot Neuroarthropathy demonstrated a higher propensity for residual collapse as demonstrated by the higher rates of broken hardware, osteomyelitis, and need for revisional exostectomy.