Delayed Diagnosis of a Medial Malleolar Fracture and its Implications in the Acute Inpatient Rehabilitation Setting: A Case Report.

Case Diagnosis: Non-displaced avulsion fracture of the right medial malleolus

Case Description or Program Description: Patient initially presented to the acute inpatient rehabilitation unit after sustaining a mechanical fall and undergoing intramedullary nailing of an intertrochanteric right hip fracture. The patient was instructed to weight bear as tolerated through the right lower extremity. Shortly after initiation of physical therapy, the patient reported both right hip and, unexpectedly, right medial ankle pain. This pain was repeatedly consistent with attempts to stand.

Setting: Acute inpatient rehabilitation facility

Assessment/Results: Focused physical examination revealed moderate right ankle pitting edema and tenderness overlying the right medial malleolus. Review of acute care imaging was revealing only for hip and pelvis studies. Point-of-care ultrasound demonstrated the bony abnormality and reliably reproduced pain to sono-palpation. X-ray of the right foot and ankle was subsequently ordered and revealed a tiny non-displaced avulsion fracture of the right medial malleolus with overlying soft tissue swelling. Outside orthopedic team was notified and recommended a CAM boot for comfort. After initial poor balance in the boot, patient eventually progressed toward modified independence with ambulation. This did not occur until shortly prior to discharge from rehabilitation, 18 days after admission.

Discussion (relevance): Ankle fractures are the third most common fracture type among geriatric patients following a fall. Though most stable medial or lateral malleolus fractures ( < 2mm) can be treated conservatively and symptomatically, early identification of small fractures can inform appropriate pain management and rehabilitation progression.

Conclusions: Missed trauma on initial assessment can present downstream challenges in a rehabilitation setting, including delayed diagnosis impacting rehabilitation participation, prolonged hospitalization, and increased risk of further injury. Ultrasound has demonstrated high sensitivity and specificity in identifying foot and ankle fractures and can be a useful bedside assessment tool, particularly in stand-alone rehabilitation facilities.