Intraoperative 3-dimensional visualization with the ISO-C-3D can provide useful information in foot and ankle trauma care that cannot be obtained from plain films or conventional C-arms. During the same procedure, after conventional C-arm scans judged the positioning to be correct and an ISO-C-3D scan was done, the reduction and/or implant position was corrected in 39% of the cases in this study, although not unnecessarily prolonging the operation. The ISO-C-3D appears to be most helpful in procedures with a closed reduction and internal fixation, and/or when axial reformations provide information that is not possible to obtain with a conventional C-arm and/or direct visualization during open reduction and internal fixation.

Injury cause, treatment, and long-term results [American Orthopaedic Foot and Ankle Society (AOFAS) Midfoot Score, Hannover Scoring System, Hannover Outcome Questionnaire] of patients with Chopart joint dislocations or fracture-dislocations were evaluated. Between 1972 and 1997, 100 patients with 110 Chopart joint dislocations were treated in the authors' institution. Pure Chopart joint dislocations were observed in 28 (25%) feet, fracture-dislocations in 60 (55%) feet, and combined Chopart-Lisfranc joint fracture-dislocations in 22 (20%) feet. The primary treatment was operative in 91 (83%) feet and nonoperative in 19 (17%) feet. Sixty-five (65%) patients had follow-up after an average of 9 years (range, 2-25 years). The mean scores of the entire follow-up group were: AOFAS score, 75 points; Hannover Scoring System, 69 points (maximium possible score = 100 points); Hannover Outcome Questionnaire, 68 points (maximium possible score = 100 points). There were no differences between the scores for pure dislocations or fracture-dislocations of the Chopart joint, but significantly lower scores were noted with combined Chopart-Lisfranc joint fracture-dislocations. In all three injury pattern groups, an initial anatomic reduction was essential for good results. The high functional restrictions in Chopart dislocations can most likely be minimized with initial open reduction, especially in fracture-dislocations. A closed reduction yielded good results only with pure dislocations, when anatomic conditions could be restored, or if there were contraindications to surgery.

Artificial calcanei (Sawbone, Synbone) showed different biomechanical characteristics than cadaver bones (embalmed and fresh-frozen) in this experimental setup with biocompatible cyclic loading. These results do not support the use of artificial calcanei for biomechanical implant testing. Fresh-frozen and embalmed specimens seem to be equally adequate for mechanical testing. The low variation of mechanical strength in the unpaired cadaver specimens suggests that the use of PAIRED specimens is not necessary.