Abstract
Background: Transcranial Doppler Ultrasound has been used to detect cerebral micremboli following long bone fractures and intramedullary stabilization. However the clinical effects in terms of cognitive function remain unclear. We aim to measure the cerebral embolic load and to clarify clinical cognitive function following lower limb long bone fractures stabilised by reamed intramedullary fixation.
Methods: 27 femoral and tibial diaphyseal fractures (median age 36 years) were cognitively assessed 3 days following surgery and compared to the normal age and intelligence matched population. A wide range of cognitive tests assessed: global cognitive function; verbal fluency and speed; immediate and delayed memory recall; attention and mental processing speeds. 20 patients had intra-operative transcranial Doppler ultrasound monitoring of the middle cerebral artery for embolic signals. In addition a marker of neuronal injury (S-100B protein) was measured pre-operatively and at 0, 24 and 48 hours following surgery. One sample Wilcoxon signed rank test compared median (percentile) cognitive scores for the fracture patient cohort to a value of 50 representing the normal population.
Results: A significant deterioration in immediate memory recall of unstructured material was noted following surgery. Using established criteria, 4 patients had detectable cerebral emboli with a median count of 3 (range 2–9). Scatter plot graphs indicated no correlation between cerebral embolic events and clinical cognitive dysfunction. S-100B protein levels increased from a pre-operative median (interquartile range) of 0.20 (0.23) to a peak immediately following surgery of 0.51 (0.97) with no correlation to clinical cognitive dysfunction
Conclusions: A small number of cerebral embolic events occur during intramedullary fracture stabilisation but with no direct correlation made to cognitive dysfunction on detailed testing. Recent concerns over the specificity of S100B protein due to extracerebral tissue release appear to be confirmed.
Significance: Clarify cognitive function following intramedullary fracture stabilisation and correlate with cerebral (systemic) embolic load.
Correspondence should be addressed to Mr Carlos Wigderowitz, Honorary Secretary BORS, University Dept of Orthopaedic & Trauma Surgery, Ninewells Hospital & Medical School, Dundee DD1 9SY.
None of the authors have received anything of value from a commercial or other party related directly or indirectly to the subject of the presentation
