Intraoperative monitoring of the femoral nerve using free electromyography during total hip arthroplasty via the direct anterior approach.

AIMS: This study aimed to use intraoperative free electromyography to examine how the placement of a retractor at different positions along the anterior acetabular wall may affect the femoral nerve during total hip arthroplasty (THA) when undertaken using the direct anterior approach (THA-DAA). METHODS: Intraoperative free electromyography was performed during primary THA-DAA in 82 patients (94 hips). The highest position of the anterior acetabular wall was defined as the "12 o'clock" position (middle position) when the patient was in supine position. After exposure of the acetabulum, a retractor was sequentially placed at the ten, 11, 12, one, and two o'clock positions (right hip; from superior to inferior positions). Action potentials in the femoral nerve were monitored with each placement, and the incidence of positive reactions (defined as explosive, frequent, or continuous action potentials, indicating that the nerve was being compressed) were recorded as the primary outcome. Secondary outcomes included the incidence of positive reactions caused by removing the femoral head, and by placing a retractor during femoral exposure; and the incidence of femoral nerve palsy, as detected using manual testing of the strength of the quadriceps muscle. RESULTS: Positive reactions were significantly less frequent when the retractor was placed at the ten (15/94; 16.0%), 11 (12/94; 12.8%), or 12 o'clock positions (19/94; 20.2%), than at the one (37/94; 39.4%) or two o'clock positions (39/94; 41.5%) (p < 0.050). Positive reactions also occurred when the femoral head was removed (28/94; 29.8%), and when a retractor was placed around the proximal femur (34/94; 36.2%) or medial femur (27/94; 28.7%) during femoral exposure. After surgery, no patient had reduced strength in the quadriceps muscle. CONCLUSION: Placing the anterior acetabular retractor at the one or two o'clock positions (right hip; inferior positions) during THA-DAA can increase the rate of electromyographic signal changes in the femoral nerve. Thus, placing a retractor in these positions may increased the risk of the development of a femoral nerve palsy. Cite this article: Bone Joint J 2022;104-B(2):193-199.

Glucocorticoids decreased Cx43 expression in osteonecrosis of femoral head: The effect on proliferation and osteogenic differentiation of rat BMSCs.

Glucocorticoid (GC)-induced osteonecrosis of the femoral head (GC-ONFH) is considered as one of the most serious side effects of long-term or over-dose steroid therapy. However, the underlying cause mechanisms are still not fully investigated. We firstly established a rat model of GC-ONFH and injected lipopolysaccharide (LPS) and methylprednisolone (MPS). We found that the expressions of Cx43, Runx2, ALP and COLⅠ were more decreased than the normal group. Secondly, the isolated rat bone marrow stem cells (BMSCs) were treated with dexamethasone (Dex) in vitro, and the expressions of Cx43, Runx2, ALP and COLⅠ were decreased significantly. Moreover, the results of immunofluorescence staining, alizarin red staining, EdU assay and CCK8 showed that the osteogenic differentiation and the proliferation capacity of BMSCs were decreased after induced by Dex. A plasmid of lentivirus-mediated Cx43 (Lv-Cx43) gene overexpression was established to investigate the function of Cx43 in BMSCs under the Dex treatment. Findings demonstrated that the proliferation and osteogenic differentiation abilities were enhanced after Lv-Cx43 transfected to BMSCs, and these beneficial effects of Lv-Cx43 were significantly blocked when PD988059 (an inhibitor of ERK1/2) was used. In conclusion, the overexpression of Cx43 could promote the proliferation and osteogenic differentiation of BMSCs via activating the ERK1/2 signalling pathway, which provide a basic evidence for further study on the detailed function of Cx43 in GC-ONFH.

Effect of the partner's health and support on cancer patients' use of general practitioner care.

OBJECTIVE: Cancer and its treatment often have a profound impact on patients, leading to increased health care use in the years after diagnosis. Social support is an important determinant of health care use. Partners of cancer patients may not always be able to provide all support patients need and patients may then revert to professional health care. We examined whether partners' health and the support they provide affect the use of general practitioner (GP) care in cancer patients. METHODS: Cancer patients aged ≥18, diagnosed <20 years ago with a cancer type with a 5-year survival rate >20% and no distant metastases were sent a questionnaire, along with their partners. Patients' self-reported recent use of GP care, i.e. whether they had discussed health problems with the GP in the past year, was assessed. Partner support as perceived by the patient was measured on three scales: Active engagement, protective buffering and overprotection. RESULTS: We included 219 patients and partners. Many patients discussed physical and emotional problems with their GP (60% and 28% of patients, respectively). Patients were less likely to discuss physical problems when they experienced active engagement and protective buffering, the latter only for females. CONCLUSION: Partner support affects use of GP care in cancer patients. GPs should therefore pay attention to the support style of the partner. GPs could ask about the support provided by the partner and inform both patients and partners about support groups where they can share experiences.

The combined effect of cancer and chronic diseases on general practitioner consultation rates.

AIM: More than two-thirds of cancer patients have one or more chronic diseases besides cancer. The purpose of this study was to get detailed insight into the combined effect of cancer and chronic diseases on general practitioner (GP) consultation rates. METHODS: From the NIVEL Primary Care Database we identified cancer patients with diabetes mellitus (n=629), osteoarthritis (n=425), coronary artery disease (n=466), COPD (n=383) or without a chronic disease (n=1507), diagnosed with cancer between 2002 and 2010. They were matched on sex, age, practice and chronic disease to 6645 non-cancer controls. RESULTS: 2-5 years after diagnosis, cancer patients without a chronic disease had on average 6.5 GP contacts per year, those with a comorbid disease almost twice as many (ranging from 10 for osteoarthritis to 12.4 for COPD). A similar difference was seen in non-cancer controls. The number of GP contacts for chronic diseases did not differ between cancer patients and controls. The increase in the number of GP consultations with age and number of chronic diseases was similar in cancer patients and controls. Consultation rates were similar in cancer patients and controls if they were stratified by number of chronic diseases while counting cancer as a chronic disease. CONCLUSIONS: Two to five years after diagnosis, cancer leads to an increase in GP contacts that is similar to having a chronic disease. This increase does not differ between those with and without a chronic disease and cancer does not seem to increase the impact of having a chronic disease.