Session V - Foot and Ankle

Chopart Joint Fracture Dislocations: Initial Open Reduction is Better than Closed Reduction

Martinus Richter, MD; Tobias Hüfner, MD; Ulf Schmidt, MD; Thomas Gosling, MD; Jens Geerling, MD; Christian Krettek, MD, FRACS; Trauma Department, Hannover Medical School, Hannover, Germany

Purpose: Cause of injury and long-term results of patients with Chopart joint dislocations or fracture dislocations were evaluated with regard to injury pattern and treatment procedures to create a basis for optimization of treatment.

Methods: Cause of injury, type and extent, treatment, and long-term results were assessed clinically and with use of pedobarography. Scores of patients with Chopart joint dislocations on the AOFAS-M (midfoot), HSS (Hannover Scoring System), and our own questionnaire were evaluated.

Results: Between 1972 and 1997, 100 patients with Chopart joint dislocations were treated at our institution. Men (N = 68) were affected twice as often as women (N = 32). The mean age was 32 years (range, 17 to 85). Both sides were involved in an equal percentage (right, 46; left, 44; bilateral, 10). Pure Chopart joint dislocations were observed in 28 patients (25%), fracture dislocations in 60 patients (55%), and combined Chopart & Lisfranc joint fracture dislocations in 22 patients (20%). Injury causes included vehicular trauma in 90, car occupants, 55; motorcyclists, 31; falls, 8; and others 10. The primary treatment was operative in 91 (83%); 10 were closed procedures, 81 had open reduction, and 12 were initial amputations. Six arthrodeses were initially performed (3 fracture dislocations, 3 Chopart and Lisfranc joint fracture dislocations), and 28 fasciotomies at the foot. Nineteen (17%) feet (exclusively pure Chopart joint dislocations) were treated nonoperatively with a short leg cast. Altogether, a secondary arthrodesis was required eight times (7.3%; three after dislocation-fracture, five after Chopart and Lisfranc joint fracture dislocations). Sixty-five (65%) patients with 66 Chopart joint dislocations (one bilateral) had follow-up examinations after an average of 9 years (range, 1 to 25); 8 patients had died before examination, and 4 had undergone an amputation. The mean scores of the entire Chopart joint dislocation follow-up group were AOFAS-M, 75 (range, 35 to 100); HSS, 69 (range, 29 to 100), and our own questionnaire, 68 (range, 30 to 100). There were no significant differences in scores because of age, sex, injury cause, time, or type of treatment. There were no differences in scores between patients with pure Chopart dislocations (mean scores, AOFAS-M, 78; HSS, 79; our own questionnaire, 73) and those with fracture dislocations (AOFAS-M, 73; HSS, 77; our own questionnaire, 68) (t-test, P>0.05). Patients with combined Chopart and Lisfranc joint fracture dislocations had significantly lower mean scores (AOFAS-M, 61; HSS, 57; our own questionnaire, 48) (t-test, P = 0.05). For patients with all three injury pattern groups, an initial anatomic reduction was essential for good results. An open reduction showed better results than closed reduction in fracture dislocations and combined Chopart and Lisfranc joint fracture dislocations (mean scores for open reduction: AOFAS-M, 75; HSS, 78; and our own questionnaire, 72; closed reduction: AOFAS-M, 55; HSS, 52; and our own questionnaire, 45) (t-test, P<0.05). For pure Chopart joint dislocations, closed and open reduction had similar results.

Discussion: Chopart joint dislocations are uncommon. In our clinical study we found the same proportion of pure Chopart joint dislocations and fracture dislocations as described in the literature. The injuries mainly occurred in multiply injured automobile occupants. Diagnosis and treatment were found to be as difficult as previously described. The overall results of the different scoring systems in our study are comparable to those of other studies. In our patients, the reduction was problematic, especially in fracture dislocations. A closed reduction could usually not restore anatomic alignment. An open reduction was considered to be necessary in those patients. In pure dislocations, a closed reduction was more successful. However, for some pure dislocations an open procedure was necessary. Our long-term results showed that open reduction in fracture dislocations was superior to closed reduction. For pure dislocations, there were no significant differences between open and closed reduction. An internal fixation was frequently necessary to maintain the reduction. In extremely unstable conditions, an additional external fixation was useful.

Conclusion: The long-term results of Chopart joint dislocations are characterized by high functional restrictions, which can most likely be minimized with initial open reduction, especially in fracture dislocations. A closed reduction is only acceptable in pure dislocations, when anatomic conditions can be restored.