Research Article: Cognitive Function in Patients Undergoing Arthroplasty: The Implications for Informed Consent

Date Published: June 20, 2011

Publisher: SAGE-Hindawi Access to Research

Author(s): N. Demosthenous, J. P. St Mart, P. Jenkins, A. Chappel, Kenneth Cheng.


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.

Partial Text

Good medical practice is a partnership between clinician and patient. It is based on sharing of information, presenting and discussing treatment options, and arriving at an informed decision. Informed consent is obtained only when a patient has received, processed, and retained this new technical information and arrives at a voluntary decision. The UK General Medical Council outlines the fundamentals of consent as listening to and respecting patients’ views, discussing and sharing relevant information required to make a decision with patients, and respecting their decision [1].

The study was carried out at the Inverclyde Royal Hospital, Greenock, Scotland, which is a district general hospital that provides a range of elective and acute trauma orthopaedic services. The inclusion criteria were patients over eighteen years of age, undergoing primary total hip replacement, total knee replacement, unicompartmental knee replacement, hip resurfacing, hip revision arthroplasty, or knee revision arthroplasty. Patients were excluded if they had any condition impairing memory or communication (dementia, cerebrovascular disease, epilepsy, head injury, dysphasia, or aphasia). Sixty-five patients were considered for inclusion over a six-month time period, and six were excluded for one of the exclusion criteria above.

Patients recalled a median three complications (IQR 1 to 4) when they attended for their procedure out of 10 that had been outlined at the prior assessment (Table 2) (Figure 1). There was no difference in complication recall between genders (MWU; P = .374). There was a negative correlation between complication recall and age (Spearman rho = −0.345, P = .007; Table 3). Patients who left full time education after nineteen years of age had a higher level of complication recall (median 3, IQR 1 to 4) compared with those with the least education (leaving full time education before age 14 (median 2, IQR 2 to 2; MWU; P = .02).

This study provides important quantitative data about the cognitive abilities of a group of patients undergoing arthroplasty. This is particular important as the transmission, receipt, and storage of information about the procedure is vital to both the legal consent process, and in the patient’s satisfaction with the outcome of the procedure by managing expectations. This study confirms that the ability to remember complications is poorer as age increases. Patients only recall 3 out of 10 major possible complications, even when specifically told they should remember them. It also shows that neuropsychological tests of memory correlate with the ability to recall this complication list. All patients showed the ability to learn; however, the younger cohort out performed their peers in the AVLT test. This suggests that older patients may need further repetition of the information or different techniques for consolidating information.

The doctor-patient dynamic is based on honesty and openness. Patients require capacity to consent for a procedure. Capacity relies on a patient’s ability to process and retain vital information regarding a procedure. We have shown that this retention of information is, at least in part, dependent on both patient age and education levels. This is increasingly important in orthopaedic patients undergoing arthroplasty because of an aging population, and therefore questions their ability to provide consent. Consent may still be possible if interventions are used to aid the transmission and recall of the benefits and risks of surgery.




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