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

It has been shown that a cognitive function (CF) loss can occur after hip or knee arthroplasty procedures, with an incidence of 40 to 70%. The pathogenesis remains unclear but studies suggest some form of brain emboli; although both trans-cranial doppler and trans-oesophageal doppler have both shown emboli per-operatively a correlation has never been shown with CF loss post-operatively. In contrast, in the cardiothoracic literature an embolic cause is widely accepted for detectable post-operative CF drop. The purpose of this study was to ascertain whether MRI could show evidence of embolic phenomena in patients undergoing hip or knee arthroplasty. Twenty-five patients presenting for hip or knee arthroplasty procedures were consented for this study. Brain MRI scans and MR angiograms were performed 1 week pre-operatively and within 1 week post-operatively using a Phillips 1.5Tesla MRI unit. All scans recorded were independently reviewed by 2 radiologists. A series of tests to examine several modes of cognitive function were carried out by a clinical psychologist pre-operatively, and at 1 week post-operatively. The CF tests showed a clinically significant drop following surgery in 64% of cases – this is in keeping with other recently published data. None of the post-operative scans or angiograms showed overt evidence of new lesions. Three Scans had equivocal tiny brainstem hypodensities on a single slice with no correlating abnormality on diffusion images to support the presence of new ischaemia. We conclude that either the aetiology of post-operative CF drop following arthroplasty is not embolic in nature, or that with current technology MRI brain scans even with angiograms are not sensitive enough to show the corresponding abnormality. With currently available equipment there appears to be no benefit from using MRI as a tool to evaluate post-operative CF loss in this group of patients

Background: Long bone fractures and intramedullary stabilisation can result in the extravasation of fat and marrow emboli into the venous circulation. The effects of these emboli can become systemic causing neurological features. Aim: To establish the cerebral microembolic load following femoral and tibial diaphyseal fractures treated by intramedullary fixation and to specify any neurological impairment with the application of a series of cognitive tests and a serum marker of neuronal injury. Methods: 20 femoral and tibial fractures treated with intramedullary fixation had intra-operative transcranial doppler ultrasound monitoring of the middle cerebral artery with emboli detection software set to established guidelines. Cognitive testing (day 3), following surgery with an I.Q. assessment (PFSIQ) allowing comparison with age specific normative data. This included: verbal fluency and speed (COWAT – Control Oral Word Association Test); working memory with assessment of immediate and delayed recall; mini-mental state examination; executive function, attention and mental processing speeds (Colour Trails 1& 2). Beta S-100 levels measured pre-operatively, 0, 24 and 48 hours following surgery as a marker of neuronal injury. Statistical Analysis: One sample Wilcoxon signed rank test to compare median of the cognitive scores with age matched normative data. Multiple regression analysis used to correlate embolic load with cognitive function. Results: Mean age (SD) for the group is 32 (5.8). Mean PFSIQ of 52.8%, SD 21.4 [median 59.5, IQ range 28.3, 71.3]. No significant difference detected in cognitive testing compared with normative data. Cerebral microemboli detected in 17 of 20 patients with a count median (range) of 6 (0, 29). The mean pre-operative beta S-100 level was 0.36 micro g/l (normal range 0–0.15). This increased to a peak mean of 0.88 micro g/l immediately following surgery with a poor correlation to cerebral embolic load. Discussion: Detailed clinical testing indicates no significant deterioration in cognitive function following intramedullary stabilisation of these fractures. A variable cerebral micro-embolic load was seen but with no detectable clinical effect. No direct correlation was found between the elevated levels of Beta S-100 seen following surgery and cerebral embolic load. This appears to correlate with previous concerns in the literature regarding the specificity and sensitivity of this established marker of neuronal injury

Study Purpose To assess clinical cognitive function and measure cerebral embolic load following primary cemented hip arthroplasty. Methods 34 primary cemented hip arthroplasty patients (mean age 69.9 (SD 11.0)0 and no history of cerebrovascular disease, underwent cognitive assessment before and after (day 4) surgery. Testing included: Verbal fluency and speed (Control Oral Word Association Test); Working memory to assess immediate and delayed recall (Weschler Memory Scale III); Attention and mental processing speeds (Colour Trails 1& 2). A one sample Wilcoxon signed rank test compared median differences before and after surgery. A sub-group of 20 patients had intra-operative transcranial Doppler ultrasound monitoring of the middle cerebral artery for embolic signals. A marker of neuronal injury (S-100B protein) was measured pre-operatively and at 0, 24 and 48 hours following surgery. Results A significant difference was noted in Colour Trails tests 1& 2 following hip arthroplasty with P values (C.I.) of 0.002 (−21, −4) and 0.023 (−15.5, −1.0) respectively. Using established emboli criteria 10 (50%) patients had true cerebral emboli with a range from 1 to 550 signals (median 2.5 interquartile range (IQ) 2 to 12.5). S-100B levels increased from a pre-operative median (IQ) of 0.15 microg/L (0.12 to 0.20) to a peak immediately following surgery of 1.88(1.36 to 4.24) returning to 0.26(0.18 to 0.37) by 48 hours (normal range: 0.03–0.15). Plotted scatter charts indicated no correlation between embolic load and cognitive dysfunction or with S-100B levels following surgery. Conclusion Cognitive testing indicates deterioration in early measured attention, visual searching and mental processing speed shortly following hip arthroplasty. No direct correlation was found between cognitive dysfunction and cerebral embolic load

Purpose of the study: Dementia in the elderly subject aged over 75 years is currently an important public health problem. An important part of the activity in orthopaedic surgery involves this age group. In 2007, 16,812 elderly persons aged over 75 years were hospitalised in our University Hospital (769 in orthopaedic surgery): 1380 patients were considered demented (40 in orthopaedic surgery). The purpose of this work was to evaluate the cognitive function of this population in a teaching hospital unit of orthopaedic and traumatology surgery where the prevalence of dementia appears to be underestimated. Material and methods: Data were collected over a period of four years. This study concerned 113 patient, including 83 women, mean age 81.8 years (range 75–92). The reason for hospitalisation was predominantly fracture of the proximal femur (73%); thirty patients had hip, knee or shoulder arthroplasty and 24 other situations. The Mini Mental State Examination (MMSE) was performed. Results: The MMSE could be interpreted for 100 patients: < 24 for 33, 24 to 26 for 29 and > 27 for 38. Among the 24 patients with no cognitive disorder known before hospitalization (nine patients known to be demented were removed from the analysis) and for whom the MMSE was completed entirely, the most frequent alterations were noted for attention, calculation, and recall-memory items. Discussion: Finally, one-third of the subjects aged over 75 years and hospitalized in our unit presented signs of altered cognitive function according to the MMSE(< 24). This score is one of the criteria for frailness of the elderly subject. This population has an unstable precarious medicosocial status with defective adaptation to stress and change in environment. These persons are exposed to a high risk of morbidity, mortality, dependence, longer hospital stay and institutionalization. The purpose of this screening is to improve management for these patients by proposing more specifically adapted care. Conclusion: It is thus indispensable to screen for cognitive disorders systematically in patients aged over 75 years hospitalized in a surgery unit. The MMSE score can be used for this purpose. This work is in favour of a physician or better a geriatrician within the unit who could be financed directly by his-her own sector of activity

Total Hip Arthroplasty (THA) surgery is a physical and cognitive challenge for surgeons. Data on stress levels, cognitive and physical load of orthopaedic surgeons, as well as ergonomic impact, are limited. With and without the use of an automated impaction device, operational efficiency and the surgeon's ergonomic, mental, and physical load was investigated.

In a total of thirty THA procedures, a standard manual technique was compared with an automated impaction device. Three computerized cognitive tasks (Simon, pattern comparison, and pursuit rotor) and five physical tests (isometric wall-sit, plank-to-fatigue, handgrip, supra-postural task, and shoulder endurance) were used to assess psychophysiological load of the surgeon. Surgeon's cortisol concentration was evaluated from saliva samples. Postural risk was assessed by Rapid Upper Limb Assessment (RULA) and Rapid Entire Body Assessment (REBA). Efficiency was assessed by timing surgical steps and instrumentation flow.

Cognitive performances after automated impaction showed faster response times and lower error rates with a greater time-on-target (+1.5 s) and a lower mouse deviation from target (−1.7 pixels). Manual impaction showed higher physical exhaustion in the isometric wall-sit test (10.6% vs. 22.9%), plank-to-fatigue (2.2% vs. 43.8%), the number of taps in the supra-postural task (−0.7% vs. −7.7%), handgrip force production in the dominant (−6.7% vs. −12.7%) and contralateral hand (+4.7% vs. +7.7%), and in shoulder endurance (−15s vs. −56s). An increase of 38.2% in salivary cortisol concentration between the midday (1.31 nmol/l) and afternoon session (1.81 nmol/l) was observed with manual impaction. After using automated impaction, salivary cortisol concentration decreased (−51.2%). Manual broaching time was on average 6′20’’ versus 7’3’’ with automated impaction. RULA of manual impaction scored 6 for cup impaction and 5 for femoral broaching, versus 3 and 3 for automated impaction, respectively. REBA of manual impaction scored 9 for cup impaction and 5 for femoral broaching, versus 4 and 3 for automated impaction, respectively.

Automated impaction lowers surgeons’ cognitive and physical fatigue and leads to reduced stress and improved ergonomics without loss of surgical efficiency.

Obtaining informed consent for an operation is a fundamental daily interaction between orthopaedic surgeon and patient. It is based on a patient's capacity to understand and retain information about the proposed procedure, the potential consequences of having it and the alternative options available. We used validated tests of memory on 59 patients undergoing lower limb arthroplasty to assess how well they learned and recalled information about their planned procedure. All patients showed an ability to learn new material, however, younger age and higher educational achievement correlated with better performance. These results have serious implications for orthopaedic surgeons discussing planned procedures. They identify groups of patients who may require enhanced methods of communicating the objectives, risks and alternatives to surgery. Further research is necessary to assess interventions to improve communication prior to surgery.

Aims

Frailty greatly increases the risk of adverse outcome of trauma in older people. Frailty detection tools appear to be unsuitable for use in traumatically injured older patients. We therefore aimed to develop a method for detecting frailty in older people sustaining trauma using routinely collected clinical data.

Aims

The aim of this study was to assess whether it is possible to predict the mortality, and the extent and time of neurological recovery from the time of the onset of symptoms and MRI grade, in patients with the cerebral fat embolism syndrome (CFES). This has not previously been investigated.

Artificial intelligence and machine-learning analytics have gained extensive popularity in recent years due to their clinically relevant applications. A wide range of proof-of-concept studies have demonstrated the ability of these analyses to personalize risk prediction, detect implant specifics from imaging, and monitor and assess patient movement and recovery. Though these applications are exciting and could potentially influence practice, it is imperative to understand when these analyses are indicated and where the data are derived from, prior to investing resources and confidence into the results and conclusions. In this article, we review the current benefits and potential limitations of machine-learning for the orthopaedic surgeon with a specific emphasis on data quality.

Aims. The aim of this study was to determine whether total hip arthroplasty (THA) for chronic hip pain due to unilateral primary osteoarthritis (OA) has a beneficial effect on cognitive performance. Methods. A prospective cohort study was conducted with 101 patients with end-stage hip OA scheduled for THA (mean age 67.4 years (SD 9.5), 51.5% female (n = 52)). Patients were assessed at baseline as well as after three and months. Primary outcome was cognitive performance measured by d2 Test of Attention at six months, Trail Making Test (TMT), FAS-test, Rivermead Behavioural Memory Test (RBMT; story recall subtest), and Rey-Osterrieth Complex Figure Test (ROCF). The improvement of cognitive performance was analyzed using repeated measures analysis of variance. Results. At six months, there was significant improvement in attention, working speed and concentration (d2-test; p < 0.001), visual construction and visual memory (ROCF; p < 0.001), semantic memory (FAS-test; p = 0.009), verbal episodic memory (RBMT; immediate recall p = 0.023, delayed recall p = 0.026), as well as pain (p < 0.001) with small to large effect sizes. Attention, concentration, and visual as well as verbal episodic memory improved significantly with medium effect sizes over η. 2. partial. = 0.06. In these cognitive domains the within-group difference exceeded the minimum clinically important difference. Conclusion. THA is associated with clinically relevant postoperative improvement in the cognitive functions of attention, concentration, and memory. These data support the concept of a broad interaction of arthroplasty with central nervous system function. Cite this article: Bone Joint J 2022;104-B(3):331–340

Background: Confusion occurs in up to 60% of patients following neck of femur fracture, delaying hospital discharge. We investigated venous – arterial circulation shunts (v-aCS) and the influence of cerebral embolism before and during surgery on subsequent cognitive function. Methods: Cerebral emboli were counted in 16 patients with an inter-trochanteric or Garden III/IV fracture by transcranial Doppler (TCD) monitoring over 1 hour pre-operatively and intra-operatively. A v-aCS was diagnosed when 1 or more microbubbles were detected in the middle cerebral artery by TCD following intravenous injection of a microbubble emulsion. Cognitive function was investigated by a battery of computerised tests preoperatively and at 5 days postoperatively. Results: Cerebral emboli were detected in 9 of 16 patients preoperatively (median 2, range 1–23) and in 10 patients during surgery (median 10, range 4 – 617). A v-aCS was associated with preoperative emboli in 9 patients (p=0.036, Fisher’s Exact) and intraoperative emboli in 10 patients (p=0.011, Fisher’s Exact). Cognitive function deteriorated following surgery only in patients with emboli, with the median (range) overall reaction times increasing from 3220ms (1926–5868) to 7493ms (4690–15992) [p=0.008]. The overall accuracy deteriorated from 2.57 to 2.37 (NS). Conclusion: Cerebral embolism is common following femoral neck fracture in patients with a v-aCS and was associated with a deterioration in cognitive function

Background. Traditionally, a Surgical Tourniquet (ST) is used during Total Knee Replacement Surgery (TKRS) to prevent blood flow to the leg and improve the surgical field of view. The use of a ST is known to increase the risk of venous thromboembolism. Echogenic material, suggestive of emboli has been observed in the brain following ST deflation in TKRS despite the absence of a patent foramen ovale, likely through pulmonary shunts. The aim of this study was to assess whether cerebral emboli result from tourniquet use in TKRS and the sequelae of any emboli. Methods. 11 subjects from a single centre undergoing routine TKRS with a ST gave informed consent. Each participant had diffusion weighted MR brain imaging prior to, and within 48 hours after TKRS and completed pre and post-operative mini-mental state examinations (MMSE). Results. Pre and post-operative MR imaging were assessed by a senior radiologist and the results were reported according to Age and Cognitive Performance Research Centre (ACPRC) rating scale. There were no changes from pre and post-operative MR scans. 4 participants (36%) had no change in MMSE scores. These participants had a score of 1 or 0 in both MR scans. 7 participants (63%) had a score of 2 or 3. These participants had mean 2.8 point (9.5%) drop on MMSE (IQR = 1) within 48 hours. Conclusions. In this small, exploratory study we found no evidence of discrete cerebral emboli occurring with the use of ST in TKRS. Interestingly, participants noted to have minimal or no pre-operative ischaemic change appeared to maintain more cognitive function post-operatively than those with higher levels of pre-existing ischaemia. Subtle changes in ischaemic load in patients with pre-existing ischaemia may lead to impaired cognitive function, however further evidence is required to confirm this theory. Level of Evidence. III. Approval. Protocol approved by NRES Committee Yorkshire & The Humber, Leeds West and The Research, Development & Innovation Department University Hospitals Coventry & Warwickshire

Orthopaedic surgical hoods rely on an intrinsic fan to force clean external air over the wearer and allow potentially contaminated and expired air to flow down and away from the surgical field. Carbon dioxide (CO. 2. ) is produced through aerobic metabolism and can potentially accumulate inside the hood. Levels above 2500ppm have been shown to affect cognitive and practical function in flight simulator studies. Maximum Health and Safety Executive (HSE) 8-hour exposure limit is 5000ppm There is a paucity of data on real-world CO. 2. levels experienced during arthroplasty surgery whilst wearing a hood. CO. 2. levels were continuously recorded during 31 elective arthroplasties, both primary and revision. Data was collected for surgeon and assistant. Data was recorded at 0.5Hz throughout the procedure utilising a Bluetooth CO. 2. detector, worn inside a Stryker Flyte. ™. surgical helmet worn with a toga gown. Four surgeons contributed real time data to the study. This data was augmented with experimental data, investigating varying fan speeds and activity levels. Median operative duration was 82 minutes (range 36–207). The average CO. 2. level across all procedures was 2952ppm, with 22 of the cases having a mean above 2500ppm, but none having a mean above 5000ppm. For each procedure, the time spent above 2500 and 5000 ppm was calculated, with the average being 68.4 % and 5.6% respectively. The experimental data demonstrated higher CO. 2. levels with lower fan speed, and at higher activity levels, and levels exceeding 15000 ppm during gentle exercise. During operative cases, low fan speed cases did have a marginally higher mean CO. 2. value than high fan speed (3033.02 and 2903.56 respectively) but the small numbers of cases (n=10) where this data was captured limit the relevance of this difference. The use of surgical helmets for elective orthopaedic surgery, can results in CO. 2. levels regularly rising to a point which may affect cognitive function. This study recommends the use of a higher fan speed where possible to minimise the risk of such CO. 2. levels, and recommends further research in this area

Cognitive impairment is common in patients with hip fracture both on admission and may develop later on. Reduced cognitive function is a risk factor for development of delirium, correlates with poor rehabilitation, and is an independent predictor of increased mortality. Despite its commonplace and potential for serious morbidity, cognitive dysfunction is often poorly assessed & diagnosed. Our aims were to 1) assess the practice of cognitive assessment on admission for hip fracture patients according to local guidelines and 2) ascertain whether it can be improved by the formal introduction of Abbreviated Mental Test Score (AMTS) & Clock Drawing Test (CDT) in the hip fracture admission proforma. A prospective audit was undertaken of cognitive assessment by either AMTS or CDT for 50 consecutive patients admitted with hip fracture from 4/8/2010. Subsequently, the hip fracture admission proforma was amended to include both the AMTS & CDT. A re-audit was performed on 50 consecutive patients admitted from 17/2/2011 to determine the change in practice. Patient demographics were comparable in both audit loops, with the mean age being equal (84 years) and an equal majority of female patients (76%). Cognitive assessment by either AMTS or CDT significant increased from 28% (n=14) to 86% (n=43) in the re-audit (p<0.0001). All AMTS were completed in accordance with instructions, whereas almost half of CDTs were incompletely or incorrectly filled out (45%). The assessment of cognitive function can be greatly improved by inclusion of both the AMTS & CDT to the hip fracture admission proforma, allowing the most appropriate multi-disciplinary care to be planned for the patient. Whilst both CDT and AMTS are good screening tools for cognitive impairment, many are unfamiliar with CDT & more training is needed

Background: Cerebral emboli may be detected by transcranial Doppler (TCD) in patients undergoing hip arthroplasty. Venous – arterial circulation shunts (v-aCS), cerebral embolism and postoperative organ dysfunction were investigated in elective hip arthroplasty. Methods: TCD was used to identify v-aCS in (i) elective hip arthroplasty (n=45), (ii) abdominal aortic aneurysm surgery (AAA) (n=20) and (iii) transurethral resection of prostate (TURP) (n=10). A v-aCS was diagnosed when 1 or more microbubbles were detected in the middle cerebral artery by TCD following intravenous injection of a microbubble emulsion. TCD was also used to monitor for intraoperative cerebral emboli (ICE). Cognitive function was measured by a battery of computerised tests before and 5 days after surgery. Troponin T, AST, ALP, Bilirubin, Creatinine, Urea and Creatinine clearance were measured pre-operatively and 24 and 48 hours post-operatively. Results: Cerebral embolism occurred in 26 of 45 patients during hip arthroplasty (median 4, range 1 – 368) but not during AAA or TURP surgery. Cerebral embolism only occurred in patients with a v-aCS (p< 0.001) and was strongly associated with the size of the v-aCS (rs=0.8, p< 0.001). The number of ICE had no influence on Troponin T, renal function, liver function or cognitive function. Conclusion: Cerebral embolism is common in patients with a v-aCS during hip arthroplasty. There was no evidence of cerebral or multi-organ damage due to paradoxical embolism

Introduction. Patients with pre-existing dementia are more susceptible to hip fracture due to various risk factors such as age, decreased activity leading to sarcopenia and osteoporosis, Vitamin D deficiency and presence of Apolipoprotein gene. The mortality associated with dementia and fracture neck of femurs was thought to be 2.3 times more than that of patients with intact cognitive function. The aim of this study is to assess the mortality of patients at 28 days, 4 months and one year after undergoing surgery for fracture neck of femurs. Methods. A retrospective study of 184 patients admitted with fracture neck of femur and had dementia for a period from April 2014 to August 2016 were carried out. The patient demographics, AMT score, pre-operative co-morbidities, perioperative mortality and one year mortality were analysed. Results. A total no. of 1007 patients was admitted with fracture neck of femurs during the study period. 184 patients were found to have pre fracture dementia. The mean age was87.088 years (Range 64–101). There was 42 males and 142 females. The average ASA grade was 2–3. 99 patients (53.8%) had Alzheimer's disease, 50 patients (27%) had vascular dementia and 35 patients (19.2%) had other types of dementia.94 patients (51%) had more than one co-morbidity. The average AMT score was 0.66(normal range 0–10). The total number of patients died was 114(62%). The overall mortality at 28 days was 24 %(44 patients=0.0001), 4 months was 46 %(84 patients) and one year was 62 %(114 patients, p=0.0001). In 90(49%) patients who had only dementia and no other co-morbidities(ASA grade 1–2) the mortality at 28 days was 20% (p=0.0051), 4 months was 40% and at one year 61%(p=0.0001). Conclusion. In our study we found that the overall mortality in patients with dementia and fracture neck of femurs is 62% and the perioperative mortality rate was 24%. The peri-operative mortality rate was 20% in patients with pure dementia. The mortally rate in dementia with fracture neck of femurs patients was far more than what is noted in the literature

The December 2022 Research Roundup³⁶⁰ looks at: Halicin is effective against Staphylococcus aureus biofilms in vitro; Synovial fluid and serum neutrophil-to-lymphocyte ratio: useful in septic arthritis?; Transcutaneous oximetry and wound healing; Orthopaedic surgery causes gut microbiome dysbiosis and intestinal barrier dysfunction; Mortality in alcohol-related cirrhosis: a nationwide population-based cohort study; Self-reported resistance training is associated with better bone microarchitecture in vegan people.

Cognitive dysfunction has been well documented following total knee replacement. Possible causes that have been postulated include cerebral emboli, post-operative complications and pain. The aim of this study is to compare cognitive decline in patients undergoing conventional total knee replacement (TKR), navigated total knee replacement and total hip replacement (THR). We prospectively analysed 75 patients undergoing lower limb arthroplasty. Group 1 consisted of 25 conventional TKR’s, group 2 consisted of 25 navigated TKR’s and group 3 consisted of 25 THR’s. Cognitive function was assessed by 11 validated neuropsychological tests preoperatively, at 1 week post-operatively and at 6 months post-operatively. Testing was carried out by a clinical psychologist. At day 6 post-operatively 55% of group 1, 83% of group 2 and 61% of group 3 patients had a significant cognitive decline. Group 2 had a significantly greater cognitive decline at day 6 compared to the other 2 groups. At 6 months significant cognitive decline was found in all 3 groups to 21%, 16% and 34% respectively. Group 2 demonstrated the greatest improvement in cognition from day 6 to 6 months post-operatively. Significant cognitive decline occurs in two-thirds (66%) of all patients undergoing lower limb arthroplasty at day 6 and remains significant in a quarter (25%) of patients at 6 months. There was no significant difference in cognitive decline in patients undergoing hip and knee arthroplasty