It has long been recognised (Hayward 1975) that preoperative information enhances perceived control in patients, facilitates patients’ active involvement in their care and therefore reduces anxiety and improves outcomes and satisfaction (Pellino 1997, 1998; Johansson et al. 2005; Walker 2007; Livbjerg et al. 2013). Inadequate information is likely to compromise patient satisfaction (Keulers et al. 2008). Adequate information provided to patients also aligns patients’ expectations with their surgeons’ (Ghomrawi et al. 2012), and appropriate expectations are key for patient satisfaction (Noble et al. 2006) although there is some controversy on this topic due to the different definitions of “expectations” (Haanstra 2012). The effect of preoperative education has been evaluated in many domains: pain, knowledge, anxiety, length of stay, self-efficacy and empowerment. It is hard to quantify the effect in each of these domains. Anxiety seems to be the element that gains the most improvement, and pain itself to a minor extent (McDonald et al. 2004; Johansson et al. 2005). Probably there are some subgroups in the patient population that will benefit the most from preoperative information, for example, those who mostly use denial as a coping strategy and those with the highest anxiety (Daltroy et al. 1998). There are many ways to convey information: via printed material, video, direct oral explanation, conference and web-based material (Gautschi et al. 2010; Jlala et al. 2010; Ihedioha et al. 2013); it is not clear which is the best manner or timing (Jlala et al. 2010). Some authors recommend that there be a moment of verbal transmission with a question-and-answer session at the end. Preoperative information should be offered prior to admission for at that stage patients are already anxious and do not retain as much information (Hughes 2002).

In an effort to interpret the reasons that compromise outcomes in the percentage of unsatisfied TKA patients, the importance of the psychological profile has been long advocated. Depression, pain and disability are clearly statistically linked. Depressed patients preoperatively have worse results after TKA surgery in terms of pain, functionality and satisfaction (Hirschmann et al. 2013; Duivenvoorden et al. 2013; Singh et al. 2013, 2014). Among depression and pain/dysfunction, it is not obvious though which is the cause and which is the effect. Some authors argue that depression is likely to be the effect rather than the cause of knee pathology at least to some extent (Blackburn et al. 2012). Pérez-Prieto et al. recently showed that although it is true that depressed patients have worse outcomes after TKA surgery, as a group they also start from worse pain and function levels preoperatively and the degree of improvement is the same as for non-depressed patients. They conclude that it is equally worthwhile for the depressed to undergo TKA surgery as for the non-depressed. To some extent the surgery will also cure the depression (Pérez-Prieto et al. 2014). Actually “depression” is too broad a concept, for it has often been used as a synonym of “poor mental health”. The SF 36 mental health subscales have been used extensively for the purpose of evaluating the psychological condition of surgical patients, but this tool seems not to be sensitive enough. Many authors recommend additional use of other scoring scales like the HAD (Hospital Anxiety and Depression scale) or other specific scales (Fosså et al. 2002; Ulvik et al. 2008).

We are interested in identifying those patients that have modifiable psychological conditions preoperatively that, if treated, might avoid the compromising of outcomes or at least might modulate correct expectations. Postoperative anxiety is a recognized risk factor for persistent post-surgical pain (Pinto et al. 2013b). Pain catastrophizing, an aspect of anxiety, seems to be a more specific trait element that can be recognized in patients. Pain catastrophising can be described as a tendency to magnify or exaggerate the threat value or seriousness of the pain sensations (Sullivan 1995). It has been proven to predict post-surgical pain severity at 6 weeks (Sullivan et al. 2009) to 6 months (Riddle et al. 2010) and has been linked to residual long-term pain after TKA (Bonnin et al. 2011; Vissers et al. 2012). Preoperative optimism is an indicator that has been evaluated and in a sense is the opposite of the pain catastrophising tendency. The optimistic patient believes that they and/or the surgery will change their condition and control their pain. Optimism as measured with the IPQ-R (Revised Illness Perception Questionnaire) and with the LOT-R (Life Orientation Test – Revised) is associated with augmented pain tolerance for diminished pain sensitivity. It has been shown to modulate acute pain (Pinto et al. 2013a). Sullivan et al. analysed “Behavioral Outcome Expectancies” as an indicator of the motivation to heal and found they where a predictor of pain and function 1 year after TKA surgery (Sullivan et al. 2011). Behavioural outcome expectancies express the confidence the patient has in returning to proper function (i.e. “How likely is it that 1 month following surgery you will have resumed your household responsibilities?”), they are likely more mediated by motivational factors. They differ from “Response” expectancies (i.e. “How likely is it that 1 month following surgery your pain will be reduced?”), which don’t imply a direct role of the patient and therefore essentially automatic or passive. Such observations seem confirmed by experiences in other settings where Anticipated Pain predicted postoperative pain scores, as suggesting a self-fulfilling prophecy (Logan et al. 2005). It seems that if patients have a positive outlook on the experience of surgery and its results, it is more likely that they will actually obtain good results. This might be because an optimistic mind creates the conditions for the best recovery or because patients have a good perception of their health after all and can to some extent predict what will happen to them. In both cases it is a good idea to investigate the patient’s point of view because it is likely to be quite accurate. To date probably the most effective tool for the psychological screening of TKA patients is the Pain Catastrophizing Scale.

If the problem is anxiety, it is plausible to imagine relaxation as a solution. There have been several attempts to produce relaxation in the perioperative setting. It is an interesting field though still relatively unexplored and can potentially offer complementary tools for the optimal management of the surgical patient. Such tools might be especially valuable in patients that cannot metabolically tolerate heavy pain medication. There are obvious advantages like non-invasiveness and non-toxicity. The costs can span from inexpensive to very expensive depending on the method and on the time spent by health-care professionals devoted to it. To date there are very few certainties in this field, and the results are promising but modest. The difficulties of applying such methods, aside from the cost issue, are that in confronting the psychological side of patients, it is difficult to standardize treatment, since varying individual tastes, culture and belief systems are involved.

Generally speaking, in the realm of relaxation techniques, there are two main objectives that are sought. One is distraction from the “drama” of surgery and the connected fears: “diversion therapy”. The other is to modify the physical symptoms of anxiety by directly controlling some of them (i.e. breathing exercises) or by triggering a pleasant mind state (i.e. imagining a peaceful scene). Methods often combine both objectives. Many relaxation techniques have been proposed: progressive muscle relaxation, music, guided imagery, awareness, attention control, hypnosis, humour and others.

The moment of surgery and the days after are inherently stressful. Some patients might not be able to cope with the intensity of these experience. Such intensity demands attention but because of the fear and aversion to the situation the patients’ mind might seek distraction in other thoughts. The mind goes back and forth from the intensity of fear to shallow distraction and back to fear again, thus potentiating such fear in the intimate knowledge of not being able to meet it fully. Such situations are very frustrating and energy consuming. Any effective way of aiding these patient should either help in meeting fully with the intensity of the moment or provide solid distraction so to avoid the back and forth of the mind above described. Better to rest the attention on something else than one’s emotion with some continuity than spiralling in fear and fear-avoidance mechanism. The goal of helping the patient to meet fully with their fear experience is very noble but quite ambitious and broad. It is likely that the TKA perioperative phase is not the appropriate setting either. A much better choice is the second option of providing occasions of solid distraction. This is the logic of distraction as a relaxation technique objective.

Anxiety creates a set of physical modifications such as increased muscle tension, heart rate, blood pressure, respiratory rate and others. Saying that anxiety “creates” reveals a belief that the mind governs the body, but actually the two sets of phenomena simply happen together like a two-sided coin with the psychological side and the physical side. It is possible to modify the psychological side by operating on the physical. Some physical symptoms are partially voluntarily modifiable and have been the terrain of relaxation techniques. Muscle tension and breathing rate are examples (Seers et al. 2008). In both these techniques, the attention is focused on the body (and thus diverted from one’s anxiety). Through alternated contraction and relaxation of muscle groups with applied awareness to the muscle activity, a lowering of muscle tension of the body at rest is achieved. Similarly, with breathing exercises, the patient actively controls the breath, depth and rhythm of breathing. At the end of the exercise, changes in breathing rhythm are noted and persist.