Prognosis of shoulder pain in those with and without a psychological disorder: A prospective cohort study with a six-month follow-up.

BACKGROUND: Because shoulder pain can have an unfavorable prognosis, it is important to have a better understanding of factors that may influence recovery. OBJECTIVE: To determine the association between recovery from shoulder pain and the presence of depression, anxiety, and pain catastrophizing. METHODS: In a prospective cohort study with a six months follow-up, we included patients visiting an orthopaedic department with shoulder pain. Primary outcome was recovery from shoulder pain measured with the Shoulder Pain and Disability Index at three and six months. Information about depression and anxiety (Hospital Anxiety and Depression Scale), pain catastrophizing (Pain Catastrophizing Scale), and demographic and clinical factors were collected at baseline. A linear mixed model was used to estimate the effects of depression, anxiety, pain catastrophizing, and underlying shoulder disorders on recovery. RESULTS: We included 190 patients. There were no statistically significant associations between the presence of depression, anxiety, and pain catastrophizing, and three- and six-month recovery. Also between the underlying shoulder disorders and recovery at three and six months, there were no statistically significant associations. CONCLUSIONS: We could not prove that depression, anxiety, and pain catastrophizing, as well as underlying shoulder disorders, were associated with recovery of shoulder pain at six months.

Does the implementation of a care pathway for patients with hip or knee osteoarthritis lead to fewer diagnostic imaging and referrals by general practitioners? A pre-post-implementation study of claims data.

BACKGROUND: The Dutch care for hip and knee osteoarthritis (OA) is of good quality, but there is room for improvement regarding the efficient use of diagnostic imaging and conservative treatment. Therefore a stepped-care approach, in the shape of the care pathway 'Better exercise in osteoarthritis', was implemented to reduce the number of diagnostic imaging requested by GPs and referrals of GPs to orthopaedic care. METHODS: In 2015, the pathway is implemented with the use of educational meetings, distributing guidelines and incorporating reminders in the GPs' referral application. To evaluate the effect of the pathway on the diagnostic and referral behaviour of GPs, hip and knee related health insurance claims are used together with claims of other joints and of a control region for comparison. The average number of claims and the percentage change in the post-implementation period are described. Binary logistic regression analysis is used to examine the interaction between region (intervention and control) and period (pre- and post-implementation). Using random sampling of patient records, information about the practical application of the pathway and the number of hip or knee arthroplasties is added. RESULTS: In both regions, the number of diagnostic imaging decreased and the number of initial orthopaedic consultations increased during the post-implementation period. Significant interaction effects were found in knee-related diagnostics (p ≤ 0.001) and diagnostics of other joints (p = 0.039). No significant interaction effects were found in hip-related diagnostics (p = 0.060) and in initial orthopaedic consultation claims of hip (p = 0.979), knee (p = 0.281), and other joints (p = 0.464). Being referred according to the pathway had no significant effect on the probability of undergoing arthroplasty. CONCLUSION: The implementation of the pathway had a positive effect on GPs diagnostic behaviour related to the knee, but not to the hip. The referral behaviour of GPs to orthopaedic care needs attention for future interventions and research, since an increase (instead of a desired decrease) in the number of initial orthopaedic consultations was found. Focusing on the entire width of care for hip and knee OA could be helpful.

Accuracy of the Precision Saw versus the Sagittal Saw during total knee arthroplasty: A randomised clinical trial.

BACKGROUND: The aim of this study was to compare the accuracy of the oscillating tip saw system (Precision Saw=PS) with the more conventional fully oscillating blade system (Sagittal Saw=SS) during computer-assisted total knee arthroplasty (CAS-TKA). METHODS: A prospective, randomised, controlled trial included 58 consecutive patients who underwent primary CAS-TKA and were randomly assigned in the PS group or the SS group to compare the accuracy of both blades. The primary outcome was the difference between the intended cutting planes and the actual cutting planes in degrees (°) in two planes of both the femur and the tibia. The secondary outcome was total surgery time. RESULTS: Tibia: In the VV-plane no significant differences were registered for the mean absolute deviation (p=0.28). The PS was more accurate in the AP-plane (p=0.03). Femur: The PS showed significantly fewer mean absolute deviations in the VV-plane (p=0.03); however, the SS revealed better accuracy in the FE-plane (p=0.04). The difference in the surgery time between the groups was not statistically significant (p=0.45). Two outliers were measured using the SS, while seven outliers were detected using the PS. CONCLUSION: The Precision Saw is not proven to be overall more accurate than the Sagittal Saw. Significantly better accuracy was shown with the PS in the two cutting planes, with the exception of one cutting plane that favoured the SS. Greater number of outliers were found using the PS. LEVEL OF EVIDENCE: II.

Switching a Catalyst System from Ethene Polymerization to Ethene Trimerization with a Hemilabile Ancillary Ligand.

A drastic ligand effect was observed in the catalytic ethene conversion by the substituted mono(cyclopentadienyl)titaniumtrichloride/methylalumoxane (MAO) catalysts shown. The catalyst with R=Me produces polyethene, whereas the catalyst with R=Ph selectively trimerizes ethene to 1-hexene. This switch in catalyst performance appears to be the result of a hemilabile behavior of the cyclopentadienyl ligand with the pendant arene group, involving reversible coordination of the arene moiety.