Surface electromyography (sEMG) studies have indicated that chronic low back pain (cLBP) involves altered electromyographic activity and morphological structure of the lumbar multifidus (LM) beyond pain perception; however, most studies have evaluated the superficial lumbar multifidus. It is difficult to record electromyography (EMG) signals from the deep multifidus (DM) to determine the neuromuscular activation patterns, making it difficult to determine the relationship between functional and structural changes in cLBP. We developed a novel method to record intramuscular EMG signals in the DM based on the sEMG system and fine-wire electrodes. We measured EMG signals of the DM in 24 cLBP patients and 26 pain-free healthy controls to identify changes in neuromuscular activation. We also used ultrasound to measure DM muscle thickness, cross-sectional area, and contraction activity to identify potential relationships between EMG activity and structural damage. cLBP patients had decreased average EMG and root mean square, but increased median frequency and mean power frequency. Average EMG was positively correlated with contractile activity, but not statistically correlated with noncontractile anatomical abnormalities. Our results suggest that cLBP alters the neuromuscular activation patterns and morphological structure of the contractile activity of the DM, providing insights into the mechanisms underlying pain perception.

Background At present, it is unclear which device (uncemented or cemented total hip arthroplasty [UTA or CTA, respectively]) is more suitable for the conversion of a failed proximal femoral nail anti-rotation (PFNA). The aim of this review was to assess the outcomes of failed PFNAs converted to a UTA or CTA device in elderly individuals with intertrochanteric femoral fractures (IFFs). Methods Two hundred fifty-eight elderly individuals (258 hips) with IFFs who underwent a conversion to a UTA or CTA device following failed PFNAs during 2007–2017 were retrospectively identified from the China Southern Medical Centre (CSMC) database. The primary endpoint was the Harris Hip Score (HHS); secondary endpoint was the key orthopaedic complication rate. Results The median follow-up was 65 months (60–69 months). Significant distinctions were observed (87.26 ± 16.62 for UTA vs. 89.32 ± 16.08 for CTA, p = 0.021; 86.61 ± 12.24 for symptomatic UTA vs. 88.68 ± 13.30 for symptomatic CTA, p = 0.026). A significant difference in the overall key orthopaedic complication rate was detected (40.8% [40/98] vs. 19.0% [19/100], p = 0.001). Apparent distinctions were detected in terms of the rate of revision, loosening, and periprosthetic fracture (11.2% for UTA vs 3.0% for CTA, p = 0.025; 13.2% for UTA vs 5.0% for CTA, p = 0.043; 10.2% for UTA vs 3.0% for CTA, p = 0.041, respectively). Conclusion For elderly individuals with IFFs who suffered a failed PFNA, CTA devices may have a noteworthy advantage in regard to the revision rate and the rate of key orthopaedic complications compared with UTA devices, and CTA revision should be performed as soon as possible, regardless of whether these individuals have symptoms.

Objective To compare medium-term clinical and radiological outcomes of primary unilateral uncemented (UN) or cemented (CE) femoral component total hip arthroplasty (THA) in elderly patients with osteoporosis. Methods Consecutive patients with osteoporosis who underwent primary unilateral UN or CE THAs at our institution from 2006 to 2013 were retrospectively reviewed. All consecutive procedures were managed by high-volume surgeons, using UN or CE THA approaches. Follow-up assessments occurred at 1, 3, 6, 9, and 12 months postoperatively, and yearly thereafter. Patient-related functional outcomes were assessed using the Harris Hip Score (HHS). Primary and secondary endpoints were early revision (<5 years) and functional outcome. Results In total, 496 primary unilateral THAs (CE, n = 184; UN, n = 182) were assessed with a median follow-up period of 75 months (range, 65–86 months). From 3 months after surgery to the final follow-up, HHS was consistently superior in the CE group. Respective prosthetic loosening rates in the UN and CE groups were 26.4% and 16.8% at a minimum of 5 years. There was a significant difference in rate of early revision (7.6% CE vs. 14.8% UN). Conclusion Compared with UN THA, CE THA exhibits a superior outcome in elderly patients with primary osteoporosis.

Background: At present, it is unclear which device (uncemented or cemented total hip arthroplasty [UTA or CTA, respectively]) is more suitable for the conversion of a failed proximal femoral nail anti-rotation (PFNA). The aim of this review was to assess the outcomes of failed PFNAs converted to a UTA or CTA device in elderly individuals with intertrochanteric femoral fractures (IFFs).Methods: Two hundred fifty-eight elderly individuals (258 hips) with IFFs who underwent a conversion to a UTA or CTA device following failed PFNAs during 2007-2017 were retrospectively identified from the China Southern Medical Centre (CSMC) database. The primary endpoint was the Harris Hip Score (HHS); secondary endpoint was the key orthopaedic complication rate.Results: The median follow-up was 65 months (60-69 months). Significant distinctions were observed (87.26±16.62 for UTA vs. 89.32±16.08 for CTA, p=0.021; 86.61±12.24 for symptomatic UTA vs. 88.68±13.30 for symptomatic CTA, p=0.026). A significant difference in the overall key orthopaedic complication rate was detected (40.8% [40/98] vs. 19.0% [19/100], p=0.001). Apparent distinctions were detected in terms of the rate of revision, loosening, and periprosthetic fracture (11.2% for UTA vs 3.0% for CTA, p = 0.025; 13.2% for UTA vs 5.0% for CTA, p = 0.043; 10.2% for UTA vs 3.0% for CTA, p = 0.041, respectively).Conclusion: For elderly individuals with IFFs who suffered a failed PFNA, CTA devices seem to have a noteworthy advantage in regard to functional scores and the rate of key orthopaedic complications compared with UTA devices, and CTA revision should be performed as soon as possible, regardless of whether these individuals have symptoms.

Objective To compare the long-term survivorship and Harris hip scores (HHSs) between cemented total hip arthroplasty (CTHA) and uncemented total hip arthroplasty (UTHA) for treatment of acute femoral neck fractures (FNFs). Methods Data of 224 hips (CTHA, n = 112; UTHA, n = 112) that underwent primary surgery in our medical institution from 2005 to 2017 were retrospectively analysed. The primary endpoint was the risk of all-cause revision. The difference in the risk of all-cause revision between the two groups was assessed by Kaplan–Meier survival analysis with a log-rank test and Cox regression analysis. Results The mean postoperative follow-up was 10 years (range, 3–13 years). The Kaplan–Meier estimated 10-year implant survival rate was significantly higher in the CTHA than UTHA group (98.1% vs. 96.2%, respectively). The adjusted Cox regression analysis demonstrated a significantly lower risk of revision in the CTHA than UTHA group. At the final follow-up, the mean HHS was significantly higher in the CTHA than UTHA group (85.10 vs. 79.11, respectively). Conclusion This retrospective analysis demonstrated that CTHA provided higher survival, lower revision risk, and higher functional outcome scores than UTHA. Further follow-up is necessary to verify whether these advantages of CTHA persist over time.

Background: At present, it is unclear which device (uncemented or cemented total hip arthroplasty [UTA or CTA, respectively]) is more suitable for the conversion of a failed proximal femoral nail anti-rotation (PFNA). The aim of this review was to assess the outcomes of failed PFNAs converted to a UTA or CTA device in elderly individuals with intertrochanteric femoral fractures (IFFs).Methods: Two hundred fifty-eight elderly individuals (258 hips) with IFFs who underwent a conversion to a UTA or CTA device following failed PFNAs during 2007-2017 were retrospectively identified from the China Southern Medical Centre (CSMC) database. The primary endpoint was the Harris Hip Score (HHS); secondary endpoint was the key orthopaedic complication rate.Results: The median follow-up was 65 months (60-69 months). Significant distinctions were observed (87.26±16.62 for UTA vs. 89.32±16.08 for CTA, p=0.021; 86.61±12.24 for symptomatic UTA vs. 88.68±13.30 for symptomatic CTA, p=0.026). A significant difference in the overall key orthopaedic complication rate was detected (40.8% [40/98] vs. 19.0% [19/100], p=0.001). Apparent distinctions were detected in terms of the rate of revision, loosening, and periprosthetic fracture (11.2% for UTA vs 3.0% for CTA, p = 0.025; 13.2% for UTA vs 5.0% for CTA, p = 0.043; 10.2% for UTA vs 3.0% for CTA, p = 0.041, respectively).Conclusion: For elderly individuals with IFFs who suffered a failed PFNA, CTA devices may have a noteworthy advantage in regard to the revision rate functional scores and the rate of key orthopaedic complications compared with UTA devices, and CTA revision should be performed as soon as possible, regardless of whether these individuals have symptoms.

Background Chronic low back pain (cLBP) affects brain functional activity of the descending pain modulatory network and altered synergistic activation of lumbar paraspinal muscles. However, the neural mechanism underlying functional reorganization and effectiveness of cooperative motion remains unexplored. Methods Fifteen cLBP patients and fifteen healthy controls underwent whole brain blood oxygen level-dependent signals measured by functional magnetic resonance imaging technique and amplitude of low-frequency fluctuation (ALFF) analysis method to identify pain-induced changes in regional spontaneous brain activity. A novel approach based on the surface electromyography system and fine-wire electrodes was used to record the EMG signals in the deep multifidus, superficial multifidus and erector spinae. Results ALFF was higher in the medial prefrontal cortex, primary somatosensory cortex, motor cortex and inferior temporal cortex in cLBP than at the baseline, whereas lower in the cerebellum, anterior cingulate cortex and posterior cingulate cortex. Further, the decrease in the average electromyography of three lumbar muscles in the cLBP group was positively correlated with the ALFF values of the primary somatosensory cortex, motor cortex, precuneus and middle temporal cortex, but significantly negatively correlated with the medial prefrontal cortex and inferior temporal cortex. Interestingly, the correlation between the functional activity in the cerebellum and the electromyography activity varied in lumbar muscles. Conclusion These findings suggest a functional association between abnormal spontaneous brain activity and altered voluntary neuromuscular activation patterns of the lumbar paraspinal muscles, providing new insights into the underlying mechanisms of pain chronicity and important implications for developing novel therapeutic targets of cLBP patients.

Objective To assess the clinical outcomes of hemi-shoulder arthroplasty (HSA) versus reverse total shoulder arthroplasty (RTSA) following failed plate osteosynthesis of proximal humerus fractures in elderly patients. Methods This retrospective study identified all patients that had a documented failed plate osteosynthesis of proximal humeral fractures treated with revision HSA or RTSA. Follow-up occurred at 1, 3, 6 and 12 months after surgery and every year thereafter. The primary outcomes were the American Shoulder and Elbow Surgeons (ASES) scores, Simple Shoulder Test (SST) scores, visual analogue scale (VAS) pain scores and the University of California, Los Angeles Shoulder Rating Scale (UCLA SRS) scores. The secondary outcome was the rate of major complications. Results A total of 126 patients (126 shoulders) were enrolled in the study. At the final follow-up, the RTSA group had significantly greater improvements in ASES, SST and UCLA SRS scores than the HSA group. The RTSA group had significantly larger decreases in the VAS pain score compared with the HSA group. The rate of major complications was significantly higher in the HSA group than in the RTSA group (44.4% versus 27.5%, respectively). Conclusion RTSA provided superior functional outcomes compared with HSA, with a lower rate of major complications after a follow-up period of at least 5 years.