Coronavirus in hip fractures (CHIP) 4 : has vaccination improved mortality outcomes in hip fracture patients?

AIMS: Prior to the availability of vaccines, mortality for hip fracture patients with concomitant COVID-19 infection was three times higher than pre-pandemic rates. The primary aim of this study was to determine the 30-day mortality rate of hip fracture patients in the post-vaccine era. METHODS: A multicentre observational study was carried out at 19 NHS Trusts in England. The study period for the data collection was 1 February 2021 until 28 February 2022, with mortality tracing until 28 March 2022. Data collection included demographic details, data points to calculate the Nottingham Hip Fracture Score, COVID-19 status, 30-day mortality, and vaccination status. RESULTS: A total of 337 patients tested positive for COVID-19. The overall 30-day mortality in these patients was 7.7%: 5.5% in vaccinated patients and 21.7% in unvaccinated patients. There was no significant difference between post-vaccine mortality compared with pre-pandemic 2019 controls (7.7% vs 5.0%; p = 0.068). Independent risk factors for mortality included unvaccinated status, Abbreviated Mental Test Score ≤ 6, male sex, age > 80 years, and time to theatre > 36 hours, in decreasing order of effect size. CONCLUSION: The vaccination programme has reduced 30-day mortality rates in hip fracture patients with concomitant COVID-19 infection to a level similar to pre-pandemic. Mortality for unvaccinated patients remained high.Cite this article: Bone Joint J 2022;104-B(12):1362-1368.

Variation of surgical anatomy of the thoracic portion of the long thoracic nerve.

Decompression of the long thoracic nerve (LTN) is a potentially beneficial procedure for selected patients with LTN palsy. The aim of this work is to describe the surgical anatomy of the thoracic part of the LTN and highlight its variations. A retrospective review of patients undergoing exploration of the LTN was performed. Preoperatively, all patients had serratus anterior dysfunction and underwent electromyographic (EMG) assessment. All patients had an initial trial of nonoperative management. The surgical procedures were undertaken by the senior author. The anatomy of the LTN and the associated vasculature was recorded in patient records, and with digital photography. Forty-five patients underwent LTN exploration. Two patients with iatrogenic injury were excluded, leaving 43 patients for analysis. Mean age was 36 years. Sixty-seven percent of cases involved the dominant side. Trauma was the commonest cause, followed by neuralgic amyotrophy. Four patients had typical features of serratus anterior dysfunction but with normal EMG studies. Two distinct patterns of LTN anatomy were noted. In 79% of cases, a single major nerve trunk coursing along serratus anterior was observed and classified as a type I LTN. In 21% of cases, two equal major branches of the nerve were identified, which was classified as a type II LTN. Approximately one in five patients may have two major branches of the LTN. This is of clinical relevance to those who undertake any thoracic procedures, as well as those who are considering exploration of the LTN.

Pre-injury use of antiplatelet and anticoagulations therapy are associated with increased mortality in a cohort of 1038 hip fracture patients.

BACKGROUND: Hip fractures are a large burden on the health care systems of developed nations. Patients usually have multiple co-morbidities and the pre-injury use of anticoagulants and anti-platelet medication is common. MATERIALS AND METHODS: This study used a single hospital hip fracture database to facilitate a retrospective analysis of the impact of anti-coagulation and anti-platelet therapy on mortality and complications after surgical management of hip fractures. There were 92 patients on warfarin, 69 on DOAC, 260 antiplatelet patients and 617 control patients. RESULTS: Mortality rates at 30 days were 4.8% for the control group, 12.6% for the antiplatelet group, warfarin 7.0%, 9.5% for Direct Oral Anticoagulant (DOAC) group, p = 0.004. Mortality rates at 1 year were 22.4% for the control group, 32.3% for the antiplatelet group, 29.3% for the warfarin group and 29.0% for DOAC group (p=0.007). Amongst complications, significant differences were found in transfusion (DOAC) and wound ooze (warfarin) rates, but the study did not detect significant clinical consequences arising from these differences. A matched analysis for age, sex, and ASA was undertaken to look in more detail at mortality data. Some mortality differences remained between groups with anti-platelet medication associated with increased mortality, but the differences no longer appeared to be significant. Our data suggests that this is a non-causal association, which could be incorporated into predictive mortality risk scores such as the Nottingham hip fracture score. CONCLUSION: We believe that pre-injury antiplatelet therapy is a strong indicator for high risk patients with higher expected mortality after hip fracture surgery. We saw no evidence to support delayed surgery in patients taking DOACs.

Vibration as an adjunct to exercise: its impact on shoulder muscle activation.

PURPOSE: There is an interest within elite sport in understanding the impact of a vibrating platform as an adjunct to exercise in the training and rehabilitation of throwing athletes. However, there has been no comprehensive evaluation of its impact on the rotator cuff muscles or its effect on the timing of shoulder muscle recruitment more globally. METHODS: Twenty healthy participants were recruited with EMG recorded from 15 shoulder girdle muscles. Isometric shoulder flexion at 25% maximal voluntary contraction was performed in three testing scenarios [no vibration; whole body vibration (WBV); and arm vibration (AV)]. A press up and triceps dips with and without vibration were also performed. Muscular recruitment was assessed pre- and post-vibration exposure as participants initiated forward flexion. RESULTS: Activation of the anterior deltoid (p = 0.002), serratus anterior (p = 0.004), and rotator cuff muscles (p = 0.004-0.022) occurred significantly earlier following exposure to vibration. Significantly greater activation was seen in the anterior, middle and posterior deltoid, upper, middle and lower trapezius, serratus anterior, teres major, latissimus dorsi, supraspinatus, and infraspinatus when the isometric contraction was performed with either WBV and/or AV (p = < 0.001-0.040). Similarly, increased activation was also demonstrated during the press up and triceps dips when performed with vibration. CONCLUSION: The use of vibration as an adjunct to exercise provokes a near global increase in shoulder muscle activation level. Furthermore, exposure to vibration alters muscular recruitment improving readiness for movement. This has potential implications within elite sport for both training and game preparation; however, further longitudinal work is required.

Patterns of muscle coordination during dynamic glenohumeral joint elevation: An EMG study.

The shoulder relies heavily on coordinated muscle activity for normal function owing to its limited osseous constraint. However, previous studies have failed to examine the sophisticated interrelationship between all muscles. It is essential for these normal relationships to be defined as a basis for understanding pathology. Therefore, the primary aim of the study was to investigate shoulder inter-muscular coordination during different planes of shoulder elevation. Twenty healthy subjects were included. Electromyography was recorded from 14 shoulder girdle muscles as subjects performed shoulder flexion, scapula plane elevation, abduction and extension. Cross-correlation was used to examine the coordination between different muscles and muscle groups. Significantly higher coordination existed between the rotator cuff and deltoid muscle groups during the initial (Pearson Correlation Coefficient (PCC) = 0.79) and final (PCC = 0.74) stages of shoulder elevation compared to the mid-range (PCC = 0.34) (p = 0.020-0.035). Coordination between the deltoid and a functional adducting group comprising the latissimus dorsi and teres major was particularly high (PCC = 0.89) during early shoulder elevation. The destabilising force of the deltoid, during the initial stage of shoulder elevation, is balanced by the coordinated activity of the rotator cuff, latissimus dorsi and teres major. Stability requirements are lower during the mid-range of elevation. At the end-range of movement the demand for muscular stability again increases and higher coordination is seen between the deltoid and rotator cuff muscle groups. It is proposed that by appreciating the sophistication of normal shoulder function targeted evidence-based rehabilitation strategies for conditions such as subacromial impingement syndrome or shoulder instability can be developed.

ELECTROMYOGRAPHIC ANALYSIS OF SHOULDER GIRDLE MUSCLES DURING COMMON INTERNAL ROTATION EXERCISES.

BACKGROUND: High level throwing performance requires the development of effective muscle activation within shoulder girdle muscles particularly during forceful internal rotation (IR) motions. STUDY DESIGN: Controlled Laboratory Descriptive Study. PURPOSE: To investigate activation pattern of 16 shoulder girdle muscles/muscle sub-regions during three common shoulder IR exercises. METHODS: EMG was recorded in 30 healthy subjects from 16 shoulder girdle muscles/muscle sub-regions (surface electrode: anterior, middle and posterior deltoid, upper, middle and lower trapezius, serratus anterior, teres major, upper and lower latissimus dorsi, upper and lower pectoralis major; fine wire electrodes: supraspinatus, infraspinatus, subscapularis and rhomboid major) using a telemetric EMG system. Three IR exercises (standing IR at 0° and 90° of Abduction, and IR at Zero-Position) were studied. EMG amplitudes were normalized to EMGmax (EMG at maximal IR force in a standard position) and compared using one-way repeated-measures analysis of variance (ANOVA). RESULTS: There were significant differences in muscles' activation across IR exercises (p<0.05-p<0.001). Rotator cuff and deltoid muscles were highly activated during IR at 90° of Abduction. Latissimus dorsi exhibited markedly higher activation during IR at Zero-Position. While upper trapezius had the highest activation during IR at Zero-Position, middle and lower trapezius were activated at highest during IR at 90° of Abduction. The highest activation of serratus anterior and rhomboid major occurred in IR at Zero-Position and IR at 90° of Abduction, respectively. CONCLUSIONS: Studied exercises have the potential to effectively activate glenohumeral and scapular muscles involved in throwing motions. Results provide further evidence for developing rehabilitation, injury prevention, and training strategies. LEVEL OF EVIDENCE: 4, Controlled laboratory study.

Electromyographic Analysis of the Shoulder Girdle Musculature During External Rotation Exercises.

BACKGROUND: Implementation of overhead activity, a key component of many professional sports, requires an effective and balanced activation of the shoulder girdle muscles, particularly during forceful external rotation (ER) motions. PURPOSE: To identify activation strategies of 16 shoulder girdle muscles/muscle segments during common shoulder ER exercises. STUDY DESIGN: Descriptive laboratory study. METHOD: Thirty healthy subjects were included in this study, and 16 shoulder girdle muscles/muscle segments were investigated (surface electrode: anterior, middle, and posterior deltoid; upper, middle, and lower trapezius; serratus anterior; teres major; upper and lower latissimus dorsi; and upper and lower pectoralis major; fine wire electrodes: supraspinatus, infraspinatus, subscapularis, and rhomboid major) using a telemetric electromyography (EMG) system. Five ER exercises (standing ER at 0° and 90° of abduction, with underarm towel roll, prone ER at 90° of abduction, side-lying ER with underarm towel) were studied. Exercise EMG amplitudes were normalized to EMG at maximum ER force in a standard position. Univariate analysis of variance and post hoc analysis applied on EMG activity of each muscle were used to assess the main effect of the exercise condition. RESULTS: Muscular activity differed significantly among the ER exercises (P < .05 to P < .001). The greatest activation for anterior and middle deltoid, supraspinatus, upper trapezius, and serratus anterior occurred during standing ER at 90° of abduction; for posterior deltoid, middle trapezius, and rhomboid during side-lying ER with underarm towel; for lower trapezius, upper and lower latissimus dorsi, subscapularis, and teres major during prone ER at 90° of abduction; and for the clavicular and sternal part of the pectoralis major during standing ER with underarm towel. CONCLUSION: Key glenohumeral and scapular muscles can be optimally activated during specific ER exercises, particularly in positions that stimulate athletic overhead motions. CLINICAL RELEVANCE: These results enable sports medicine professionals to target specific muscles during shoulder rehabilitation protocols while minimizing the effect of others, providing a foundation for optimal evidence-based exercise prescription. They also provide information for tailored muscle training and injury prevention in overhead sports.

Muscle strength and its relationship with skeletal muscle mass indices as determined by segmental bio-impedance analysis.

PURPOSE: Despite increasing interest in bio-impedance analysis (BIA) for estimation of segmental skeletal muscle mass (SMM), published results have not been entirely convincing. Furthermore, a better understanding of the relationship between muscle strength and SMM will be useful in interpreting outcomes of physical/training interventions particularly in groups with diverse body sizes (e.g. men vs women). This study aimed to measure SMM in the upper body (upper extremity and torso), to determine its correlation with muscle strength and to examine the effects of gender on muscle strength-muscle mass relationship. METHODS: Segmental (upper extremity and torso) SMM and muscle strength in five distinct shoulder planes (forward flexion, abduction in scapular plane, abduction in coronal plane, internal and external rotation) were measured in 45 healthy participants (22 males, 23 females) with mean age 30.3 years. Statistical analysis included independent t tests, Pearson correlation, and multiple regression analysis. RESULTS: Men and women differed significantly in body mass (BMI: 25.9 ± 4.3 vs 23 ± 3.6) and SMM (p < 0.01). A strong relationship correlation was found between the five shoulder strength measurements and upper extremity SMM (r = 0.66-0.80, p < 0.01), which was not affected by gender. There was a significant gender difference (p < 0.01) in absolute shoulder strength, but not after normalisation to the SMM. CONCLUSION: BIA-estimated SMM of upper extremity and torso was highly correlated with upper extremity (shoulder) strength independent of gender. SMM may, therefore, be useful for the normalisation of muscle strength allowing size-independent comparisons of muscle strength in individuals with diverse physical characteristics.

Shoulder muscle activation and coordination in patients with a massive rotator cuff tear: an electromyographic study.

Adaptive muscle activation strategies following a massive rotator cuff tear (MRCT) are inadequately understood, and the relationship among muscles during everyday activities has not been considered. Thirteen healthy subjects comprised the control group, and 11 subjects with a MRCT the patient group. Upper limb function was assessed using the Functional Impairment test-hand, neck, shoulder, and arm (FIT-HaNSA). Electromyography (EMG) was recorded from 13 shoulder muscles, comprising five muscle groups, during a shelf-lifting task. Mean FIT-HaNSA scores were significantly lower in MRCT patients (p≤0.001), reflecting a severe functional deficit. In MRCT patients, EMG signal amplitude was significantly higher for the biceps brachii-brachioradialis (p < 0.001), upper trapezius-serratus anterior (p= 0.025), muscle groups and for the latissimus dorsi (p = 0.010), and teres major (p=0.007) muscles. No significant differences in the correlation among muscle groups were identified, pointing to an unchanged neuromuscular strategy following a tear. In MRCT patients, a reorganization of muscle activation strategy along the upper limb kinetic chain is aimed at reducing demand on the glenohumeral joint. Increased activation of the latissimus dorsi and teres major muscles is an attempt to compensate for the deficient rotator cuff. Re-education towards an alternate neuromuscular control strategy appears necessary to restore function.

Normal shoulder muscular activation and co-ordination during a shoulder elevation task based on activities of daily living: an electromyographic study.

Studies of normal shoulder function have often failed to consider the inter-relationship between different muscle groups in activities relevant to daily life. Upper limb functional status was assessed in 12 healthy male volunteers using the Functional Impairment Test-Hand, Neck, Shoulder and Arm test (FIT-HaNSA). Electromyography was then used to study the activity and coordination of 13 muscles (10 by surface electrodes, 3 by fine-wire intramuscular electrodes) around the shoulder during a dynamic movement task based on the shelf-lifting task in FIT-HaNSA. Muscles were grouped for analysis into deltoid (anterior, middle, and posterior divisions), adductors (latissimus dorsi and teres major), rotator cuff (supraspinatus, infraspinatus, and subscapularis), and elbow flexor (brachioradialis, biceps brachii) groups. There were no significant inter-session effects. Using cross-correlation analysis to investigate the whole time-course of activation, there were highly significant positive correlations (p < 0.001) between the deltoid and rotator cuff, the deltoid and adductor and the adductor and rotator cuff groups, and a significant negative correlation between the deltoid and elbow flexor groups (p = 0.031). We conclude that the deltoid, adductor, and rotator cuff muscles all contribute to the muscular component of glenohumeral joint stability. Muscular stability can be adapted as required to meet task-specific demands.