Background: Ankle fractures are among the most common injuries
treated by orthopaedic surgeons. However, very few investigators have examined
the functional recovery following ankle fracture surgery and, to our
knowledge, none have analyzed factors that may predict functional recovery. In
this study, we evaluated predictors of short-term functional outcome following
surgical stabilization of ankle fractures.
Methods: Over three years, 232 patients who sustained a fracture of
the ankle and were treated surgically were followed prospectively, for a
minimum of one year. Trained interviewers recorded baseline characteristics,
including patient demographics, medical comorbidities, and functional status
according to the Short Musculoskeletal Function Assessment (SMFA). Laboratory
findings, the American Society of Anesthesiologists (ASA) class, and operative
findings were recorded from the chart during hospitalization. Follow-up
information included the occurrence of complications or additional surgery,
weight-bearing status, functional status according to the SMFA, and the
American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score. The
data were analyzed to determine predictors of functional recovery at three
months, six months, and one year postoperatively.
Results: Complete follow-up data were available for 198 patients
(85%). At one year, 174 (88%) of the patients had either no or mild ankle pain
and 178 (90%) had either no limitations or limitations only in recreational
activities. According to the AOFAS ankle-hindfoot score, 178 (90%) of the
patients had =90% functional recovery. A patient age of less than forty
years was a predictor of recovery, as measured with the SMFA subscores, at six
months after the ankle fracture. At one year, however, age was no longer a
predictor of recovery. Patients who were younger than forty were more likely
to recover =90% of function (p = 0.004), and men were more likely than
women to recover function (p = 0.02). ASA Class 1 or 2 (p = 0.03) and an
absence of diabetes (p = 0.02) were also predictors of better functional
recovery at one year. SMFA subscores were below average at baseline,
indicating a healthy population. At three and six months postoperatively, all
SMFA subscores were significantly higher than the baseline subscores (p <
0.001); however, at one year, the SMFA subscores were almost back to the
baseline, normal level.
Conclusions: One year after ankle fracture surgery, patients are
generally doing well, with most experiencing little or mild pain and few
restrictions in functional activities. They have a significant improvement in
function compared with six months after the surgery. Younger age, male sex,
absence of diabetes, and a lower ASA class are predictive of functional
recovery at one year following ankle fracture surgery. It is important to
counsel patients and their families regarding the expected functional recovery
after an ankle injury.
Level of Evidence: Prognostic Level I. See Instructions
to Authors for a complete description of levels of evidence.