FUNCTIONAL OUTCOMES AFTER ACUTE FRACTURES OF THE FIFTH METATARSAL BASE TREATED WITH TWO DIFFERENT CASTING METHODS

Abstract

Background: This prospective study was done to evaluate functional outcomes after acute avulsion fractures of the fifth metatarsal base. The objective was to compare the results of two different casting methods adopted as a treatment of non-displaced avulsion fractures of the fifth metatarsal.

Methods: Fifty-two patients who sustained an avulsion fracture of the fifth metatarsal base and presented to the outpatient clinic of our hospital system were treated according to the advice of the attending clinicians. A total of 49 patients were available for 3 months follow up. There were eight men and 41 women with an average age of 41.9 (range 17 to 81) years. The lower extremity was placed in a below knee [n=28] or slipper cast [n=21] and patients were allowed to bear weight as tolerated. Baseline data collection consisted of demographic information, and radiographic, and functional evaluation. Patients were seen at regularly scheduled visits for 6 weeks and then at 3 months to obtain follow up information. A Short Musculoskeletal Function Assessment (SMFA) questionnaire was obtained at 3/12 year. Analyses were performed to determine differences in outcome based on demographics and injury information.

Results: Based on self-reports, 10 patients with slipper cast had returned to pre-injury functional status by 3 weeks, compared to 22 patients with below knee cast by 6 weeks. An average of 22 days were lost from work, with 9 patients taking up to 10 days, 13 taking 3 weeks or longer off work. Twenty eight patients were losing more than 6 weeks of work in the other group. All were provided with pain killers, crutches if needed and none required thromboembolic prophylaxis with low molecular heparin. After twelve weeks none of the patients complained about pain. Radiographic consolidation of the fracture was noticed after 7 weeks for the avulsion fractures. As regard to the costing approximately 4 pounds for the slipper cast and 12 pounds were spent on the below knee casting.

Conclusions: Fracture of the fifth metatarsal base often is a source of lost work productivity. Patients can be expected to return to their preinjury level of function with slipper type of cast earlier than below knee cast. Slipper types of casting are cost effective, efficient and offer greater mobility to the patients.