Measuring recovery and understanding long-term deficits in balance, ankle mobility and hip strength in people after an open reduction and internal fixation of bimalleolar fracture and their impact on functionality: a 12-month longitudinal study

Abstract

To analyze how balance and other physical capacities evolved after surgery in patients with a bimalleolar fracture and how these capacities and clinical variables (immobilization or unloading time) contribute to restoring patients'functionality, 22 patients and 10 healthy people (HC) were assessed for static and dynamic balance (Y-Balance test, YBT), dorsiflexion ankle mobility (ADFROM) and hip strength at 6 and 12 months after surgery. Patients' functional status was assessed through the Olerud Molander Ankle Score (OMAS) and the American Orthopaedic Foot and Ankle Society (AOFAS) score. Twenty-one patients with ankle fractures who completed the study showed a worse static and dynamic balance at 6 months. The YBT in the anterior direction (YBTA) revealed balance deficits in the operated limb at 12 months compared to the non-operated limb (--5.6%) and the HC (--6.7%). They also showed a decreased ADFROM compared to the non-operated limb (--7.4º) and the HC (--11º). In addition, medium-term (6 months) deficits in abductor strength hip but no hip strength deficits were found at 12 months after surgery. Relative weight analyses showed that ADFROM and hip strength explained 35-63% of the YBTA variance and AOFAS/OMAS scores. Balance, hip strength and ADFROM seem to be reliable indexes for assessing the functional status of these patients. These results could help to understand the relationship between these physical capacities and the patients' perceived functional status.