Cerebral emboli and cognitive function after intramedullary fracture fixation
Introduction
Concerns exist about orthopaedic procedures which instrument the intramedullary canal due to the production of emboli. Pulmonary embolisation detected by transoesophageal echocardiography during such procedures regularly produces detectable hypoxaemia and clinical effects.3, 15 In addition, cerebral embolic events have more recently been detected after intramedullary fracture stabilisation using transcranial Doppler ultrasound.7 Whether such events are associated with a clinical effect on cerebral function remains unclear. Sensitive and validated neuropsychological testing methods are available and have recently demonstrated subtle cognitive decline after knee arthroplasty surgery.16 However in this study no correlation was found with the detection of cerebral emboli. Cognitive dysfunction after cardiac bypass surgery is well recognised with a high intraoperative cerebral embolic load being a main predictor.20
The aim of this study was firstly to use transcranial Doppler ultrasound to measure the frequency and distribution of intraoperative cerebral emboli during the intramedullary nailing of femoral and tibial diaphyseal fractures. A range of sensitive neuropsychological tests were then applied after surgery to assess for any clinical cognitive change. Any correlation between the intra-operative cerebral embolic load and cognitive function was then established. Our hypothesis was that the level of cerebral embolisation would be lower than that required to consistently produce cognitive change.
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Materials and methods
Local Research Ethical Committee approval and written consent from each patient was obtained (LREC No. 2003/R/OST/02). Twenty non-consecutive patients with a median age of 38 years (range 17–79) were recruited by the primary investigator after admission to the orthopaedic trauma unit. Inclusion criteria were femoral or tibial diaphyseal fractures that required intramedullary stabilisation under general anaesthesia. Exclusion criteria included patients aged under 16 or greater than 80 years and
Statistical methods
All information was recorded and analysed using the SPSS software package version 11.0 (SPSS, Inc., Chicago, Illinois). Each cognitive test result was expressed as a percentile difference compared to the predicted pre-morbid score (PFSIQ (%)). A Wilcoxon signed-rank test was then used to determine if this difference was significant (p value < 0.05).
Mann–Whitney U tests compared the median cognitive test score differences of patients who had cerebral embolic events and those who did not. This was
Cerebral emboli detection
Four patients had detectable cerebral embolic events with counts of only 2, 3, 3 and 9 respectively. The highest cerebral embolic load occurred after intramedullary fixation of a pathological femoral fracture secondary to a metastatic deposit from small-cell lung neoplasia. The other three patients had isolated tibial fractures. The distributions of embolic events over the phases of each stabilisation procedure are demonstrated in Fig. 1. The majority were detectable during and immediately
Discussion
Specific and quantifiable defects in cognitive function were detectable after surgery. First, patients performed significantly worse than predicted on a test, which required them to repeat number sequences of increasing length (digit span). Secondly, patients performed more poorly than would have been anticipated on a test of verbal recall in both immediate and delayed conditions. Furthermore, interference scores indicated that memory consolidation was adversely affected by the presentation of
Conclusions
A relatively small volume of cerebral embolus was detected predominantly during the intramedullary instrumentation phase of long bone fracture stabilisation. No direct correlation was found between this embolic load and the poorer cognitive results detected using the more sensitive clinical tests. This poor correlation is similar to recent studies involving arthroplasty patients and conforms to the cardiac surgery literature where such low levels of systemic embolisation would be unlikely to
Conflict of interest statement
No benefits in any form have been received or will be received from a commercial party related to the subject of this article by any of the authors. There are no conflicts of interest from any of the authors with regards this study.
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Surgical techniques: how I do it? The Reamer/Irrigator/Aspirator (RIA) System
2009, InjuryCitation Excerpt :However, although reamed intramedullary nailing has long been considered a safe procedure, pulmonary complications have been reported in some groups of patients.14,24,31 Concerns over fat embolisation, adult respiratory distress syndrome (ARDS), sudden intraoperative death and aseptic cortical thermal necrosis have prompted some authors to question whether the benefits of reaming are outweighed by its potential adverse effects to the patient.5,6,10,21,13,27,33,45,5,15,19,49 In response to these complications, recent evaluations have focused on alternative systems that reduce intramedullary pressure during reaming.35,39
Incidence of fat embolism syndrome in femur fractures and its associated risk factors over time—A systematic review
2021, Journal of Clinical MedicineReview of transcranial doppler ultrasound to detect microemboli during orthopedic surgery
2014, American Journal of Neuroradiology