Michael Dunbar

Patient satisfaction after knee arthroplasty: A report on 27,372 knees operated on between 1981 and 1995 in Sweden

During a validation process of the Swedish Knee Arthroplasty Register (SKAR), living registered patients were sent a questionnaire to ask if they had been reoperated on. This gave an opportunity to pose a simple four-point question with respect to patient satisfaction which 95% of patients answered. We analyzed the answers of patients operated on between 1981 and 1995 and found that only 8% of the patients were dissatisfied regarding their knee arthroplasty 2-17 years postoperatively. The satisfaction rate was constant, regardless of when the operation had been performed during the 15-year period. The proportion of satisfied patients was affected by the preoperative diagnosis, patients operated on for a long-standing disease more often being satisfied than those with a short disease-duration. There was no difference in proportions of satisfied patients, whether they had primarily been operated on with a total knee arthroplasty (TKA) or a medial unicompartmental arthroplasty (UKA). For TKAs performed with primary patellar resurfacing, there was a higher ratio of satisfied patients than for TKAs not resurfaced, but this increased ratio diminished with time passed since the primary operation. Unrevised knees had a higher proportion of satisfied patients than knees that had been subject to revision, and among patients revised for medial UKA, the proportion of satisfied patients was higher than among patients revised for TKA. We conclude that satisfaction after knee arthroplasty is stable and long-lasting in unrevised cases and that even after revision most patients are satisfied.

Psychological determinants of problematic outcomes following Total Knee Arthroplasty

ABSTRACT The primary objective of the present study was to examine the role of pain‐related psychological factors in predicting pain and disability following Total Knee Arthroplasty (TKA). The study sample consisted of 75 (46 women, 29 men) individuals with osteoarthritis of the knee who were scheduled for TKA. Measures of pain severity, pain catastrophizing, depression, and pain‐related fears of movement were completed prior to surgery. Participants completed measures of pain severity and self‐reported disability 6 weeks following surgery. Consistent with previous research, cross‐sectional analyses revealed significant correlations among measures of pre‐surgical pain severity, pain catastrophizing, depression and pain‐related fears of movement. Prospective analyses revealed that pre‐surgical pain severity and pain catastrophizing were unique predictors of post‐surgical pain severity (6‐week follow‐up). Pain‐related fears of movement were predictors of post‐surgical functional difficulties in univariate analyses, but not when controlling for pre‐surgical co‐morbidities (e.g. back pain). The results of this study add to a growing literature highlighting the prognostic value of psychological variables in the prediction of post‐surgical health outcomes. The results support the view that the psychological determinants of post‐surgical pain severity differ from the psychological determinants of post‐surgical disability. The results suggest that interventions designed to specifically target pain‐related psychological risk factors might improve post‐surgical outcomes.

Comparison of Health-Related Quality of Life Between Patients with End-Stage Ankle and Hip Arthrosis

BACKGROUND End-stage ankle arthrosis is one of the leading causes of chronic disability in North America. Information on this condition is limited. The amount of pain and the reduction in health-related quality of life and function have not been quantified with use of universal outcome measures. The purpose of the present study was to compare the extent of pain, loss of function, and health-related quality of life in two cohorts of patients waiting for the surgical treatment of end-stage ankle or hip arthrosis. METHODS One hundred and thirty patients with end-stage ankle arthrosis who were awaiting total ankle arthroplasty or ankle arthrodesis were recruited through a Canadian Orthopaedic Foot and Ankle Society multicenter study. All patients prospectively completed the Short Form-36 (SF-36) generic outcome instrument. This cohort was compared with a similar cohort of 130 patients with end-stage hip arthrosis, randomly selected from an existing prospective joint replacement database, who had completed an SF-36 questionnaire prospectively from 2000 to 2005. RESULTS In both groups, the scores for all SF-36 subscales were approximately two standard deviations below normal population scores. Patients with ankle arthrosis had significantly worse mental component summary scores (p < 0.05), role-physical scores (p < 0.05), and general health scores (p < 0.05). Patients with hip arthrosis reported significantly lower physical function scores (p < 0.05), although the SF-36 physical component summary score was not significantly different between the two groups. The SF-36 physical component summary, bodily pain, vitality, role-emotional, social functioning, and mental health subscale scores were equally affected in both cohorts. CONCLUSIONS The mental and physical disability associated with end-stage ankle arthrosis is at least as severe as that associated with end-stage hip arthrosis.

Appropriate questionnaires for knee arthroplasty. Results of a survey of 3600 patients from The Swedish Knee Arthroplasty Registry.

The Swedish Knee Arthroplasty Registry (SKAR) has recorded knee arthroplasties prospectively in Sweden since 1975. The only outcome measure available to date has been revision status. While questionnaires on health outcome may function as more comprehensive endpoints, it is unclear which are the most appropriate. We tested various outcome questionnaires in order to determine which is the best for patients who have had knee arthroplasty as applied in a cross-sectional, discriminative, postal survey. Four general health questionnaires (NHP, SF-12, SF-36 and SIP) and three disease/site-specific questionnaires (Lequesne, Oxford-12, and WOMAC) were tested on 3600 patients randomly selected from the SKAR. Differences were found between questionnaires in response rate, time required for completion, the need for assistance, the efficiency of completion, the validity of the content and the reliability. The mean overall ranks for each questionnaire were generated. The SF-12 ranked the best for the general health, and the Oxford-12 for the disease/site-specific questionnaires. These two questionnaires could therefore be recommended as the most appropriate for use with a large knee arthroplasty database in a cross-sectional population.

Prospective relation between catastrophizing and residual pain following knee arthroplasty: two-year follow-up.

BACKGROUND Pain is the primary indication for both primary and revision total knee arthroplasty (TKA); however, most arthroplasty outcome measures do not take pain into account. OBJECTIVE To document the prospective pain experience following TKA, with subjective pain-specific questionnaires to determine if comorbidities, preoperative pain or preoperative pain catastrophizing scores are predictive of long-term pain outcomes. METHODS Fifty-five patients with a primary diagnosis of osteoarthritis of the knee, who were scheduled to undergo TKA, were asked to fill out the McGill Pain Questionnaire (MPQ) and the Pain Catastrophizing Scale (PCS) preoperatively and at three, 12 and 24 months follow-up. Comorbidities were extracted from the Queen Elizabeth II Health Sciences Centre health information system. RESULTS The overall response rate (return of completed questionnaires) was 84%. There was a significant decrease in the MPQ scores (P<0.05) postoperatively. PCS scores did not change over time. Receiver operating characteristic curves revealed the number of comorbidities per patient predicted the presence of pain postoperatively, as documented by the numerical rating subscale of the MPQ at 24 months (P<0.05). Receiver operating characteristic curves for preoperative PCS and rumination subscale scores predicted the presence of pain, as measured by the Pain Rating Index subscale of the MPQ at 24 months (P<0.05). Preoperative PCS scores and comorbidities were significantly higher in the persistent pain group (P<0.05). CONCLUSIONS The number of comorbidities predicted the presence of pain at 24 months follow-up and, for the first time, preoperative PCS scores were shown to predict chronic postoperative pain. This may enable the identification of knee arthroplasty patients at risk for persistent postoperative pain, thus allowing for efficient administration of preoperative interventions to improve arthroplasty outcomes.

A systematic review of the effect of waiting for treatment for chronic pain.

&NA; In many countries timely access to care is a growing problem. As medical costs escalate health care resources must be prioritized. In this context there is an increasing need for benchmarks and best practices in wait‐time management. The Canadian Pain Society struck a Task Force in December 2005 to identify benchmarks for acceptable wait‐times for treatment of chronic pain. As part of the mandate a systematic review of the literature regarding the relationship between waiting times, health status and health outcomes for patients awaiting treatment for chronic pain was undertaken. Twenty‐four studies met the inclusion criteria for the review. The current review supports that patients experience a significant deterioration in health related quality of life and psychological well being while waiting for treatment for chronic pain during the 6 months from the time of referral to treatment. It is unknown at what point this deterioration begins as results from the 14 trials involving wait‐times of 10 weeks or less yielded mixed results with wait‐times amounting to as little as 5 weeks, associated with deterioration. It was concluded that wait‐times for chronic pain treatment of 6 months or longer are medically unacceptable. Further study is necessary to determine at what stage the deterioration begins from the onset of pain to treatment and the impact of waiting on treatment outcomes. Most important is the need to improve access to appropriate care for patients with chronic pain, an escalating public health care problem with significant human and economic costs.

The porous coated anatomic total hip replacement: A ten to fourteen-year follow-up study of a cementless total hip arthroplasty

Background: We previously reported our two and five‐year results of arthroplasty with the Porous Coated Anatomic total hip prosthesis. We now report on the performance of this prosthesis at ten to fourteen years. Methods: The results of 311 total hip replacements in which a Porous Coated Anatomic prosthesis was inserted without cement in 279 patients were analyzed prospectively. The average age of the patients at the time of the replacement was sixty-one years (range, twenty to eighty‐one years). Sixty‐four patients (seventy-six hips) died postoperatively. Forty‐five patients (forty‐seven hips) were lost to follow‐up, and four were excluded because of their medical condition. One hundred and sixty‐eight patients (187 hips) were followed for ten to fourteen years (average, twelve years). Seventeen of those patients (seventeen hips) had a revision. Results: The overall survival rate (with any revision as the end point) was 90.0% ± 5.4% at fourteen years, with an average Harris hip score of 85 ± 14 points. The prevalence of thigh pain was 36% (fifty-six of 157) in the late period (more than ten years postoperatively). Radiographs showed stable fixation, with bone ingrowth, of 83% (130) of the 156 acetabular components and 88% (137) of the 156 femoral components at the latest follow‐up evaluation. Men had a significantly higher rate of femoral osteolysis than did women (p < 0.001). The rates of acetabular and femoral osteolysis associated with 32‐mm femoral heads (49% [twenty-three] of forty-seven and 70% [thirty-three] of forty-seven, respectively) were significantly higher (p < 0.01) than those associated with 26‐mm heads (26% [twenty-eight] of 109 and 30% [thirty-three] of 109, respectively). Despite this, revision (removal or exchange of components) was not directly related to head size; instead, it was related to polyethylene thickness. Conclusions: There have been persistent problems with the Porous Coated Anatomic hip system, including thigh pain and an increasing prevalence of osteolysis with time. Revision because of aseptic loosening was related more to the thickness of the polyethylene liner than to the size of the femoral head. Femoral heads with a 32-mm diameter did not increase the risk for revision provided that an adequate thickness of polyethylene had been used.

Extensor mechanism failure associated with total knee arthroplasty: prevention and management.

Abstract Extensor mechanism complications are the most commonly reported reasons for revision surgery after total knee arthroplasty and are a frequent source of postoperative morbidity. Patellofemoral instability is the most commonly reported extensor mechanism complication and has multiple etiologies, including prosthetic malalignment and soft‐tissue imbabalce. Patellar fracture or rupture of either the quadriceps or patellar tendon can cause catastrophic disruption of the extensor mechanism. Although some stable fractures can be successfully managed nonsurgically, displaced fractures or tendon rupture often lead to poor results. Other complications include patellar clunk and soft‐tissue adhesions, prosthetic wear or loosening, and osteonecrosis. Increased understanding of implant alignment, rotation, and soft‐tissue balance, as well as improved design of the trochlear groove of femoral implants and patellar components, has resulted in a decline in extensor mechanism complications. Appropriate prosthetic selection and meticulous surgical technique remain the keys to avoiding unsatisfactory results and revision surgery.

The role of presurgical expectancies in predicting pain and function one year following total knee arthroplasty

Summary Patients’ behavioral outcome expectancies assessed presurgically predicted pain severity and physical function 1 year after total knee arthroplasty (TKA) and partially mediated the relation between catastrophizing and TKA outcomes. Abstract The present study examined the prospective value of response expectancies (ie, pain, sleep) and behavioral outcome expectancies (ie, return to function) in the prediction of pain severity and functional limitations 12 months after total knee arthroplasty (TKA). The study sample consisted of 120 individuals (73 women, 47 men) with osteoarthritis of the knee who were scheduled for TKA. Measures of expectancies, pain severity, pain catastrophizing, pain‐related fears of movement, and depression were completed prior to surgery. Participants also completed measures of pain severity and functional limitations 12 months following surgery. Analyses revealed that behavioral outcome expectancies were stronger predictors of follow‐up pain and functional limitations than response expectancies. Consistent with previous research, analyses also revealed that pain catastrophizing, pain‐related fear of movement, and depression predicted follow‐up pain and function. In a multivariate analysis, only pain catastrophizing contributed significant unique variance to the prediction of follow‐up pain and function. Behavioral outcome expectancies partially mediated the relation between catastrophizing and follow‐up pain and function. The relation between catastrophizing and follow‐up pain severity and functional limitations remained significant even when controlling for behavioral outcome expectancies. The results suggest that interventions designed to specifically target behavioral outcome expectancies and catastrophizing might improve post‐surgical outcomes.

Past incidence and future demand for knee arthroplasty in Sweden: a report from the Swedish Knee Arthroplasty Register regarding the effect of past and future population changes on the number of arthroplasties performed

By combining data from the Swedish Knee Arthroplasty Register and Swedish census registers we have calculated the past age-specific incidence of primary knee arthroplasties and predicted the demand. During the last 20 years, osteoarthrosis has accounted for the largest increase in number of knee arthroplasties while operations for rheumatoid arthritis remained constant. The mean yearly number of operations between the periods 1976-1980 and 1996-1997 increased more than five-fold, while only 6% of that increase could be explained by changes in the age-profile of the population. Most operations were performed on persons of 65 years and older who also had the largest increase in incidence. By using the incidences for 1996 and 1997 and taking into account the expected future changes in the age profile of the Swedish population, we estimate that, in the absence of an effective preventive treatment, the number of knee arthroplasties will increase by at least one third until 2030.