Lewallen, David G.

ObjectiveTo study the time trends in sociodemographic and clinical characteristics of patients undergoing primary total knee arthroplasty (TKA).MethodsWe used the Mayo Clinic Total Joint Registry to examine the time trends in patient demographics (body mass index [BMI] and age), underlying diagnosis, medical (Deyo‐Charlson Index) and psychological comorbidity (anxiety and depression), and examination findings of primary TKA patients from 1993–2005. We used the chi‐square test and analysis of variance.ResultsIn total, 7,229 patients constituted the primary TKA cohort; 55% were women. The mean age decreased by 1.3 years (69.3 to 68.0 years), mean BMI increased by 1.7 kg/m2 (30.1 to 31.8 kg/m2), and mean Deyo‐Charlson Index increased by 36% (1.1 to 1.5) over the 13‐year study period (P ≤ 0.001 for all). Compared with 1993–1995, significantly more patients (by 2–3 times) in 2002–2005 had a BMI ≥40 kg/m2 (4.8% versus 10.6%), age <50 years (2.9% versus 5.2%), Deyo‐Charlson Index of ≥3 (12% versus 22.3%), depression (4.1% versus 14.8%), and anxiety (4.1% versus 8.9%), and significantly fewer patients had an underlying diagnosis of rheumatoid/inflammatory arthritis (6.4% versus 1.5%; P < 0.001 for all). Compared with 1993–1995, significant reductions were noted in 2002–2005 for the physical examination findings of anteroposterior knee instability, mediolateral knee instability, moderate to severe knee synovitis, severe limp, fair or poor muscle strength, and absent peripheral pulses (P ≤ 0.001 for all).ConclusionIn this large US total joint registry study, we found significant time trends in patient characteristics, diagnosis, comorbidity, and knee/extremity examination findings in primary TKA patients over 13 years. These secular trends should be taken into account when comparing outcomes over time and in policy‐making decisions.

ObjectiveTo determine the association of the underlying diagnosis with limitation in activities of daily living (ADL) and pain in patients undergoing primary total knee arthroplasty (TKA).MethodsProspectively collected data from the Mayo Clinic Total Joint Registry were used to assess the association of diagnosis with moderate–severe limitation in ADL and moderate–severe pain at 2 and 5 years after primary TKA, using multivariable‐adjusted logistic regression analyses. We calculated odds ratios (ORs) and 95% confidence intervals (95% CIs).ResultsThere were 7,139 primary TKAs at 2 years and 4,234 at 5 years. In multivariable‐adjusted analyses, compared with rheumatoid arthritis (RA)/inflammatory arthritis, osteoarthritis (OA) was associated with significantly lower moderate–severe ADL limitation at 2 years (OR 0.5 [95% CI 0.3–0.8]) (P = 0.004) and at 5 years (OR 0.5 [95% CI 0.3–0.9]) (P = 0.02). There was no significant association of diagnosis of OA with moderate–severe pain at 2 years (OR 1.2 [95% CI 0.5–2.7]) (P = 0.68) or at 5 years (OR 1.0 [95% CI 0.3–3.7]) (P = 1.0).ConclusionWe found that patients with OA who underwent primary TKA had better ADL outcomes compared to patients with RA/inflammatory arthritis at 2 and 5 years. On the other hand, the pain outcomes after primary TKA did not differ in OA versus RA. This suggests a discordant effect of underlying diagnosis on pain and function outcomes after TKA. These novel findings can be used to better inform both patients and surgeons about expected pain and function outcomes after primary TKA.

Seligman’s theory of causal attribution predicts that patients with a pessimistic explanatory style will have less favourable health outcomes. We identified 702 patients who had undergone 894 primary total knee replacements between 1993 and 2005, who responded to follow-up surveys at two (n = 783 knee replacements) and/or five years (n = 443 knee replacements) and had also completed the Minnesota Multiphasic Personality Inventory long before the joint replacement (median = 16.6 and 14.5 years for two- and five-year cohorts, respectively). Scores from the Minnesota Multiphasic Personality Inventory Optimism-Pessimism scale were used to categorise patients as pessimistic (t-score > 60) or non-pessimistic (t-score ≤ 60). Multivariate logistic regression models assessing the effect of pessimistic explanatory style on pain or improvement in knee function were adjusted for gender, age, distance from the place of treatment and depression score. Pessimists reported (a) significantly more moderate or severe pain at two years with odds ratio 2.21 (95% confidence interval (CI) 1.12 to 4.35; p = 0.02), but not at five years when the odds ratio was 1.21 (95% CI 0.51 to 2.83; p = 0.67); and (b) less improvement in knee function at two years when the odds ratio was 0.53 (95% CI 0.30 to 0.96; p = 0.04), but not at five years when the odds ratio was 1.26 (95% CI 0.57 to 2.77; p = 0.57). No significant associations with moderate or severe limitation of activity were seen at two or five years. We conclude that a pessimistic explanatory style is associated with worse pain and functional outcomes two years after total knee replacement.

Increasing application of expensive medical technologies, including joint replacement, is of concern in the current economic climate. Successful upper limb joint replacements (ULJRs) are being performed, but few detailed data about their utilization are available. To explore the resource implications of such surgery, the utilization of total shoulder replacement (TSR), total elbow replacement (TER) and total wrist replacement (TWR) were examined from the time these procedures first became available at the Mayo Clinic up to 1990. The age- and sex-adjusted utilization rate for TSR among Olmsted County, Minnesota, residents was 1.8 per 100000 person-years (p-y), 0.8 per 100000 p-y for TER and 1.1 per 100000 p-y for TWR. Overall utilization of primary ULJR among Olmsted County residents during the 19-year study period was 3.8 per 100000 p-y. The commonest indication for TSR was osteoarthritis (46 per cent) and for TER and TWR was rheumatoid arthritis (50 and 81 per cent respectively). There was no consistent trend in the utilization of these procedures among Olmsted County residents, but the number of referral patients receiving a ULJR at the Mayo Clinic increased steadily during the study period. The Mayo Clinic experience suggests an increasing demand for ULJR, particularly TSR and TER. With continued advances in, and diffusion of, the technology this demand may increase further.