Total Hip Arthroplasty (THA) and Total Knee Arthroplasty (TKA) can provide patients with significant pain relief as well as improving their overall functional ability. The success of these procedures is difficult to measure, however Patient Reported Outcome Measures and patient satisfaction are being used increasingly as indicators of surgical success. Satisfaction and dissatisfaction after THA and TKAare well reported, with dissatisfaction after TKA being as much as 20%1,2 compared with 7% 3 after THA. As the age range of patients requiring THA or TKA changes, so has the range of patient expectations. Fulfillment of these pre-operative expectations should in turn lead to greater patient satisfaction.
The authors have sought to quantify pre-operative expectations for THA and TKA, assess the subsequent level of fulfillment of these expectations post-operatively, and correlate the fulfillment of the expectations with patient satisfaction. In addition they have attempted to identify why satisfaction differs between THA and TKA. The expectation questions for THA were identical to those used in the Hospital for Special Surgery (HSS) Hip Replacement surveys and those for TKA were altered from the HSS Knee Surgery expectations survey to give a more reflective view of an arthroplasty population.
This was a prospective study with large patient numbers in both groups. The data were collected pre-operatively and at 12 months after surgery. Patient expectations were ranked according to importance. The post-operative level of fulfillment of each of these expectations was recorded. Functional outcomes were measured using the Oxford Hip (OHS) and Oxford Knee Scores (OKS) along with both mental and physical components of the Short form (SF-12) health questionnaire. In addition to this, patients were asked ‘how satisfied’ they were with their hip or knee by choosing from four options: very satisfied, satisfied, uncertain or dissatisfied.
Improvement in the ability to walk and relief of daytime pain were ranked as the most important expectations pre-operatively in both groups. The level of expectation did not differ significantly between the groups, however multivariable analysis did reveal significant predictors of high expectation. These included age and pre-operative mental component score (of the SF-12) in THA, and age, male gender, OKS and SF-12 score (both components) in TKA. Expectation fulfillment was significantly higher in THA than TKA, which was similar to other studies4, and exceeded expectations in many areas, although interestingly many of these criteria were ranked low in their level of importance, for example medication requirement, psychological well-being, employment and sexual activity. TKA failed to meet expectations in three activities: stair climbing, kneeling and squatting. This may be related to the range of post-operative knee flexion as those patients with high flexion (>130°) have been shown to have a lower level of functional limitation than their counterparts with poorer flexion and were more likely to have their pre-operative expectations met.5 We might suspect that patients with poor pre-operative OHS, OKS and SF-12 scores were more likely to have high levels of expectation fulfillment however the authors found this not to be the case with better pre-operative scores significantly predicting higher levels of fulfillment, and thus satisfaction. This is in contrast to published data3,6 showing that Oxford scores have no predictive accuracy in identifying those who will be satisfied or dissatisfied. Neither the presence of symptomatic arthritis in another major joint nor complications were assessed in the study, both of which may affect satisfaction.3
The study aimed to shed light on why satisfaction differs between THA and TKA. They have shown that pre-operative expectations are similar for both groups with pain relief and walking ability as key factors however TKA is not yet fulfilling the ‘high knee flexion’ activities that patients are wanting from modern TKA. Expectation fulfillment is directly linked to the improvement in pain and changes in functional ability and these are in turn related to whether a patient feels satisfied or not.
The authors should be commended for their work. It is a paper that contains a large amount of useful information that should make surgeons examine how they select patients suitable for surgery and how patients are counselled regarding expectations and goals of surgery. The inclusion of complication rates and range of knee flexion post-operatively may have helped better understand the complex multifactorial outcome of patient satisfaction.
Mr D McMurray, Leeds, UK and Professor Riaz Khan, Australia
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2. Baker PN, Van der Meulen JH, Lewsey J, Gregg PJ. The role of pain and function in determining patient satisfaction after total knee replacement. Data from the National Joint Registry for England and Wales. J Bone Joint Surg [Am] 2007;89-A:893-900.
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5. Devers BN et al. Does greater knee flexion increase patient function and satisfaction after Total Knee Arthroplasty. J Arthroplasty 2011;26:178-186.
6. Judge A et al. Assessing patients for joint replacement; can pre-operative Oxford Hip and Knee scores be used to predict patient satisfaction following joint replacement surgery and to guide patient selection? J Bone Joint Surg [Br] 2011;93-B:1660-4