Preoperative Predictors of Postoperative Opioid Usage,Pain Scores,and Referral to a Pain Management Service in Total Knee Arthroplasty

Background

Little is known about preoperative predictors of postoperative pain and referral to a recuperative pain management service after total knee arthroplasty (TKA).

Questions/Purposes

We sought to identify the preoperative predictors of postoperative pain scores, referral to a pain management service, and narcotic usage in patients undergoing primary total knee arthroplasty.

Methods

We performed a prospective cohort study of 97 TKAs from a single surgeon. Pre and 6-week postoperative WOMAC, visual analog pain scale (VAS) scores, narcotic usage, and catastrophizing pain scores were collected.

Results

After adjusting for all other variables, higher age and catastrophizing pain scores were associated with lower odds of postoperative opioid usage. Increasing age and BMI were associated with lower odds of being referred to pain management. There was no relationship between self-reported preoperative pain tolerance and postoperative change in WOMAC or VAS pain scores.

Conclusions

This information may help surgeons advise their patients preoperatively and set expectations during the recovery period.

Electronic supplementary material

The online version of this article (doi:10.1007/s11420-014-9418-4) contains supplementary material, which is available to authorized users.     

A patient with a large pulmonary saddle embolus eluding both clinical gestalt and validated decision rules

We report a patient with chest pain who was classified as having low risk for pulmonary embolism with clinical gestalt and accepted clinical decision rules. An inadvertently ordered D-dimer and abnormal result, however, led to the identification of a large saddle embolus. This case illustrates the fallibility of even well-validated decision aids and that an embolism missed by these tools is not necessarily low risk or indicative of a low clot burden.     

Treatment of fibromyalgia at the Maharishi Ayurveda Health Centre in Norway II—a 24-month follow-up pilot study

Treatments offered at the Maharishi Ayurveda Health Centre in Norway are based on Maharishi Vedic Medicine (MVM). MVM is a consciousness-based revival by Maharishi Mahesh Yogi, the founder of the Transcendental Meditation (TM) program of the ancient Ayurvedic medicine tradition in India. To extend from 6 to 24 months, a pilot study of the effects of the treatment program at the Health Centre on fibromyalgia. Retesting 2 years after a clinical trial. In this intention to treat study, 31 women with a diagnosis of fibromyalgia received an individually tailored program of (1) physiological purification therapy (Maharishi Panchakarma) and (2) Ayurvedic recommendations regarding daily routine and diet including a novel approach to food intolerance. Five subjects chose to learn TM for stress reduction, pain management and personal development. All were recommended Ayurvedic herbal products for follow-up treatment. A modified Fibromyalgia Impact Questionnaire (FIQ) that included seven dimensions. Scores at 24 months follow-up were compared with pre-treatment scores. At 24-months follow-up, there were significant reductions (26% to 44%) in six of the seven fibromyalgia dimensions: impairment of working ability, pain, tiredness, morning tiredness, stiffness and anxiety. The 7th, depression, decreased 32% (borderline significant). At 24 months, the four subjects who continued practising TM, had almost no symptoms and significantly lower FIQ change scores (−92% to 97%) than the non-meditators on all outcomes. This pilot study suggests that the treatments and health promotion programs offered at the Maharishi Ayurveda Health Centre in Norway lead to long-term reductions in symptoms of fibromyalgia, which is considered a treatment-resistant condition, and further studies are warranted.     

Impact of amino acid sequence variation of a determinant(s) on the antigenic properties of hepatitis B virus HBsAg

Impact of amino acid sequence variation on the antigenic properties of the surface hepatitis B virus antigen HBsAg was studied. Eleven recombinant HBsAg variants of wild (adr, ayw2, adw2, adw4, aywl, adw2) and vaccine escape (adw2 T126S, adw2 Q129L, adw2 Q129R, adw2 T143K, adw2 Q145R, aywl Q145A) were obtained. All the recombinant antigens were tested on a panel of 43 monoclonal antibodies (MAb) specific to different HBsAg determinants. Amino acid sequence variation of the a-determinant of HBsAg was shown to significantly affect its immunological responsiveness and antigenic properties. Amino acid substitution in different positions or in the same position, but for various amino acids may differently affect these properties.     

Distinguishing acute from chronic and resolved hepatitis C virus (HCV) infections by measurement of anti-HCV immunoglobulin G avidity index

An assay to measure avidity index (AI) was developed to diagnose incident hepatitis C virus (HCV) infections. The assay demonstrated an AI value statistically significantly lower in primary HCV infections than in chronic infections. When the assay was applied to past resolved infections, the difference in AI values was not as significant as the difference between incident and chronic infections. Lower AI values obtained in past resolved infections may be directly related to lower levels of immunoglobulin G anti-HCV in past resolved infections than in either new infections or chronic infections.     

Influence of biochemical composition on endplate cartilage tensile properties in the human lumbar spine

Endplate cartilage integrity is critical to spine health and is presumably impaired by deterioration in biochemical composition. Yet, quantitative relationships between endplate biochemical composition and biomechanical properties are unavailable. Using endplate cartilage harvested from human lumbar spines (six donors, ages 51–67 years) we showed that endplate biochemical composition has a significant influence on its equilibrium tensile properties and that the presence of endplate damage associates with a diminished composition–function relationship. We found that the equilibrium tensile modulus (5.9 ± 5.7 MPa) correlated significantly with collagen content (559 ± 147 µg/mg dry weight, r² = 0.35) and with the collagen/GAG ratio (6.0 ± 2.1, r² = 0.58). Accounting for the damage status of the adjacent cartilage improved the latter correlation (r² = 0.77) and indicated that samples with adjacent damage such as fissures and avulsions had a diminished modulus–collagen/GAG relationship (p = 0.02). Quasi‐linear viscoelastic relaxation properties (C, τ₁, and τ₂) did not correlate with biochemical composition. We conclude that reduced matrix quantity decreases the equilibrium tensile modulus of human endplate cartilage and that characteristics of biochemical composition that are independent of matrix quantity, that is, characteristics related to matrix quality, may also be important. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:245–252, 2014.     

Intramuscular administration of human tissue-type plasminogen activator in rabbits and dogs and its implications for coronary thrombolysis

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Rapid prenatal diagnosis of beta thalassemia using DNA amplification and nonradioactive probes

We used in vitro DNA amplification by the polymerase chain reaction and nonradioactive probes for prenatal diagnosis of beta thalassemia in Chinese from the Guangdong province. Exact molecular diagnoses were made in all 20 fetuses studied over a 6-month period. We conclude that this method of prenatal diagnosis for beta thalassemia is a viable approach in many parts of the world where this disease is common.