gms | German Medical Science

Objectives: The authors compared complication rate, radiological and clinical results by treating consequently calcanaeal fractures of all Sanders-types with an interlocking calcaneal nail (C-Nail) with those results of literature using extended lateral approach and plate fixation.

Methods: In a prospective, consecutive study of 152 cases standard x-rays for measuring Böhler's angle, CT-scans for Sanders- classification, judging posterior facet fragment dislocation pre- and postoperatively were performed. In all cases a lateral position of the patient, a 4 cm long sinus tarsi approach, a 6.5 mm Schanz-screw with handle for tuber fragment manipulation and fluoroscopic control for joint reduction and mini-open screw fixation of the posterior facet was used . After reduction and temporary K-wire fixation of the tuber and anterior process fragments a guide wire for the 65 mm long C-nail was inserted in the lateral third of the calcaneus below the insertion of the Achilles tendon and directed to the middle hight of the calcaneo-cuboideal joint. Through a 1cm vertical incision the nail was then inserted into the overdrilled hole with the attached aiming device. Through the sustentacular arm two K-wires were positioned ideally under fluoroscopic control into the sustentacular fragment and substituted after overdrilling by two locking screws. The tuber and anterior process fragment were then fixed analogously with two locking screws each through the superior and lateral guiding arm.

Results: Between 2011 and 2015 a total of a 152 cases was treated with the C-nail. According to Sanders were treated: Type I (n=13), IIA (n=53), IIB (n=34), IIC (n = 7), IIIAB (n=25), IIIAC (n=4), IIIBC (n=6), IV (n=10). Out of 152 fractures three open fractures (0,2%) were treated immediately, all others within the first three days. The average age of patients was 45 years (17-73), 73 patients were heavy smokers, 15 non-insulin dependend diabetic patients. Böhler's angle was improved from 6,3° to 31.5 ° postoperatively, the posterior facet step off from 4,9 mm to 0.8 mm. According to AOFAS the clinical outcome of 120 patients 6 months after surgery counted 93,1 (65-100) points, in 73 patients 12 months after surgery 93,7 points (75-100). Despite 3 open fractures and 88 risky patients involved, only one infection (0.7 %) was seen , what was significantly different to literature.

Conclusion: The interlocking C-nail with mini-open sinus tarsi approach renders joint reduction, comparable AOFAS results to literatur and a significant lower infection rate of 0.7% even in higher risk cases.