Bonnie Chien1, Kurt Hofmann2, Mohammad Ghorbanhoseini3, David Zurakowski4, Edward K Rodriguez5, Paul Appleton6, J Kent Ellington7, John Y Kwon8. 1. Harvard Combined Orthopaedic Residency Program, Boston, MA, USA. 2. New England Baptist Hospital, Boston, MA, USA. 3. Carl J. Shapiro Department of Orthopaedics, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA mghorban@bidmc.harvard.edu. 4. Department of Anesthesia, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA. 5. Orthopaedic Trauma, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA. 6. Orthopaedic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA. 7. OrthoCarolina, Foot and Ankle Institute, Charlotte, NC, USA. 8. Carl J. Shapiro Department of Orthopaedics, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
Abstract
BACKGROUND: Determining the stability of ankle fractures, particularly Weber B fibula fractures, can be challenging. Ability to weight-bear after injury may be predictive of stability. We sought to determine whether patients' ability to weight-bear immediately after injury was an effective indicator for ankle stability following fracture. METHODS: A prospective review was conducted of patients sustaining ankle fractures. Patients' ability to weight-bear after injury was elicited and correlated with ankle radiographs, which were deemed stable or unstable based on commonly used indices to assess stability. RESULTS: For the entire cohort (n = 121), patients who were able to weight-bear immediately after injury were over 8 times more likely to have a stable fracture than those who could not (odds ratio [OR] = 8.6, P < .001). Positive predictive value (PPV) for being able to fully weight-bear as it related to stability was 73%. Inability to weight-bear was 85% specific among patients with an unstable fracture. When analyzing patients with radiographic isolated fibula fractures (n = 67), PPV = 82%, negative predictive value [NPV] = 53%, specificity = 79%, whereas the OR was 5.0 (P = .003) for those who could weight-bear having a stable fracture. When subanalyzing patients who presented with isolated fibula fractures and anatomic mortises (n = 43), PPV = 74%, NPV = 52%, specificity = 62%, whereas the OR was 3.6 (P = .07) for those who could weight-bear having a stable fracture. CONCLUSION: Patients' ability to weight-bear immediately after injury was a specific and prognostic indicator for stability across a range of ankle fracture subtypes. Patients with an isolated fibula fracture and anatomic mortise were 3.6 times more likely to have a stable fracture if they were able to fully weight-bear at the time of injury. Although a patient's history does not preclude the need for appropriate imaging studies and clinical judgment, it may aid in the assessment of ankle stability following fracture. LEVEL OF EVIDENCE: Level II, clinical diagnostic.
BACKGROUND: Determining the stability of ankle fractures, particularly Weber B fibula fractures, can be challenging. Ability to weight-bear after injury may be predictive of stability. We sought to determine whether patients' ability to weight-bear immediately after injury was an effective indicator for ankle stability following fracture. METHODS: A prospective review was conducted of patients sustaining ankle fractures. Patients' ability to weight-bear after injury was elicited and correlated with ankle radiographs, which were deemed stable or unstable based on commonly used indices to assess stability. RESULTS: For the entire cohort (n = 121), patients who were able to weight-bear immediately after injury were over 8 times more likely to have a stable fracture than those who could not (odds ratio [OR] = 8.6, P < .001). Positive predictive value (PPV) for being able to fully weight-bear as it related to stability was 73%. Inability to weight-bear was 85% specific among patients with an unstable fracture. When analyzing patients with radiographic isolated fibula fractures (n = 67), PPV = 82%, negative predictive value [NPV] = 53%, specificity = 79%, whereas the OR was 5.0 (P = .003) for those who could weight-bear having a stable fracture. When subanalyzing patients who presented with isolated fibula fractures and anatomic mortises (n = 43), PPV = 74%, NPV = 52%, specificity = 62%, whereas the OR was 3.6 (P = .07) for those who could weight-bear having a stable fracture. CONCLUSION:Patients' ability to weight-bear immediately after injury was a specific and prognostic indicator for stability across a range of ankle fracture subtypes. Patients with an isolated fibula fracture and anatomic mortise were 3.6 times more likely to have a stable fracture if they were able to fully weight-bear at the time of injury. Although a patient's history does not preclude the need for appropriate imaging studies and clinical judgment, it may aid in the assessment of ankle stability following fracture. LEVEL OF EVIDENCE: Level II, clinical diagnostic.