SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Shoulder

170

Aseptic loosening of all-polyethylene glenoid components remains a limiting factor in achieving long-term implant survival in total shoulder arthroplasty (TSA). This study prospectively evaluated the functional and radiographic outcomes of patients undergoing TSA with a novel, porous, tantalum-backed glenoid component, with a minimum 2 years of follow-up.

Concepts: Vector space, Shoulder

169

Changes in muscle activities are commonly associated with shoulder impingement and theoretically caused by changes in motor program strategies. The purpose of this study was to assess for differences in latencies and deactivation times of scapular muscles between subjects with and without shoulder impingement. Twenty-five healthy subjects and 24 subjects with impingement symptoms were recruited. Glenohumeral kinematic data and myoelectric activities using surface electrodes from upper trapezius (UT), lower trapezius (LT), serratus anterior (SA) and anterior fibers of deltoid were collected as subjects raised and lowered their arm in response to a visual cue. Data were collected during unloaded, loaded and after repetitive arm raising motion conditions. The variables were analyzed using 2 or 3 way mixed model ANOVAs. Subjects with impingement demonstrated significantly earlier contraction of UT while raising in the unloaded condition and an earlier deactivation of SA across all conditions during lowering of the arm. All subjects exhibited an earlier activation and delayed deactivation of LT and SA in conditions with a weight held in hand. The subjects with impingement showed some significant differences to indicate possible differences in motor control strategies. Rehabilitation measures should consider appropriate training measures to improve movement patterns and muscle control.

Concepts: Muscle, Humerus, Shoulder, Deltoid muscle, Clavicle, Glenohumeral joint, Scapula, Serratus anterior muscle

151

The aims of this study were to determine the survival of anatomic total shoulder arthroplasty with uncemented metal-backed (MB) glenoid components with a polyethylene (PE) insert in primary osteoarthritis, to assess the reasons for revision surgery, and to identify patients and diagnostic factors that influence failure rates.

Concepts: Medicine, Physician, Osteoarthritis, Hip replacement, Shoulder, Failure rate, Shoulder replacement, Scapula

64

Shoulder pathologies of the rotator cuff of the shoulder are common in clinical practice. The focus of this pictorial essay is to discuss the anatomical details of the rotator interval of the shoulder, correlate the anatomy with normal ultrasound images and present selected pathologies. We focus on the imaging of the rotator interval that is actually the anterosuperior aspect of the glenohumeral joint capsule that is reinforced externally by the coracohumeral ligament, internally by the superior glenohumeral ligament and capsular fibers which blend together and insert medially and laterally to the bicipital groove. In this article we demonstrate the capability of high-resolution musculoskeletal ultrasound to visualize the detailed anatomy of the rotator interval. MSUS has a higher spatial resolution than other imaging techniques and the ability to examine these structures dynamically and to utilize the probe for precise anatomic localization of the patient’s pain by sono-palpation.

Concepts: Biology, Anatomy, Medical school, Human anatomy, Anatomical terms of location, Shoulder, Rotator cuff, Glenohumeral joint

37

The scapula functions as a bridge between the shoulder complex and the cervical spine and plays a very important role in providing both mobility and stability of the neck/shoulder region. The association between abnormal scapular positions and motions and glenohumeral joint pathology has been well established in the literature, whereas studies investigating the relationship between neck pain and scapular dysfunction have only recently begun to emerge. Although several authors have emphasised the relevance of restoring normal scapular kinematics through exercise and manual therapy techniques, overall scapular rehabilitation guidelines decent for both patients with shoulder pain as well as patients with neck problems are lacking. The purpose of this paper is to provide a science-based clinical reasoning algorithm with practical guidelines for the rehabilitation of scapular dyskinesis in patients with chronic complaints in the upper quadrant.

Concepts: Vertebral column, Shoulder, Cervical vertebrae, Glenohumeral joint, Scapula, Acromion

35

Rotator cuff related shoulder pain (RCRSP) is an over-arching term that encompasses a spectrum of shoulder conditions including; subacromial pain (impingement) syndrome, rotator cuff tendinopathy, and symptomatic partial and full thickness rotator cuff tears. For those diagnosed with RCRSP one aim of treatment is to achieve symptom free shoulder movement and function. Findings from published high quality research investigations suggest that a graduated and well-constructed exercise approach confers at least equivalent benefit as that derived from surgery for; subacromial pain (impingement) syndrome, rotator cuff tendinopathy, partial thickness rotator cuff (RC) tears and atraumatic full thickness rotator cuff tears. However considerable deficits in our understanding of RCRSP persist. These include; (i) cause and source of symptoms, (ii) establishing a definitive diagnosis, (iii) establishing the epidemiology of symptomatic RCRSP, (iv) knowing which tissues or systems to target intervention, and (v) which interventions are most effective.

Concepts: Diagnosis, Greek loanwords, Symptom, Symptomatic treatment, Shoulder, Rotator cuff, Shoulder problems, Rotator cuff tear

35

PURPOSE: It is commonly stated that supraspinatus initiates abduction; however, there is no direct evidence to support this claim. Therefore, the aims of the present study were to determine whether supraspinatus initiates shoulder abduction by activating prior to movement and significantly earlier than other shoulder muscles and to determine if load or plane of movement influenced the recruitment timing of supraspinatus. METHODS: Electromyographic recordings were taken from seven shoulder muscles of fourteen volunteers during shoulder abduction in the coronal and scapular planes and a plane 30° anterior to the scapular plane, at 25%, 50% and 75% of maximum load. Initial activation timing of a muscle was determined as the time at which the average activation (over a 25ms moving window) was greater than three standard deviations above baseline measures. RESULTS: All muscles tested were activated prior to movement onset. Subscapularis was activated significantly later than supraspinatus, infraspinatus, deltoid and upper trapezius, while supraspinatus, infraspinatus, upper trapezius, lower trapezius, serratus anterior and deltoid all had similar initial activation times. The effects of load or plane of movement were not significant. CONCLUSIONS: Supraspinatus is recruited prior to movement of the humerus into abduction but not earlier than many other shoulder muscles, including infraspinatus, deltoid and axioscapular muscles. The common statement that supraspinatus initiates abduction is therefore, misleading.

Concepts: Humerus, Shoulder, Rotator cuff, Supraspinatus muscle, Deltoid muscle, Muscles of the upper limb, Scapula, Serratus anterior muscle

34

Frozen shoulder is a poorly understood condition that typically involves substantial pain, movement restriction, and considerable morbidity. Although function improves overtime, full and pain free range, may not be restored in everyone. Frozen shoulder is also known as adhesive capsulitis, however the evidence for capsular adhesions is refuted and arguably, this term should be abandoned. The aim of this Masterclass is to synthesise evidence to provide a framework for assessment and management for Frozen Shoulder. Although used in the treatment of this condition, manipulation under anaesthetic has been associated with joint damage and may be no more effective than physiotherapy. Capsular release is another surgical procedure that is supported by expert opinion and published case series, but currently high quality research is not available. Recommendations that supervised neglect is preferable to physiotherapy have been based on a quasi-experimental study associated with a high risk of bias. Physiotherapists in the United Kingdom have developed dedicated care pathways that provide; assessment, referral for imaging, education, health screening, ultrasound guided corticosteroid and hydro-distension injections, embedded within physiotherapy rehabilitation. The entire pathway is provided by physiotherapists and evidence exists to support each stage of the pathway. Substantial on-going research is required to better understand; epidemiology, patho-aetiology, assessment, best management, health economics, patient satisfaction and if possible prevention.

Concepts: United Kingdom, Shoulder, Joint manipulation, Adhesive capsulitis of shoulder, Hydrodilatation, Diseases involving the fasciae

31

The reverse fly machine is a popular exercise for strengthening the horizontal shoulder abductors including the posterior deltoid. . There seems to be little consensus as to which hand position most effectively targets the posterior deltoid despite this option on most machines. This study investigated the impact of varying one’s hand position, and consequently altering shoulder joint rotation, on muscle activity in various glenohumeral muscles during exercise on the reverse fly machine. Nineteen resistance trained men (mean age = 23.2 ± 4.3 years; height =176.9 ± 7.1 centimeters; body mass = 81.3 ± 10.5 kilograms; body mass index = 25.9 ± 2.6) were recruited from a university population to participate in the study. In a repeated measures design, subjects grasped the hand bars on the machine with either a pronated (PRO) or neutral (NEU) grip and performed dynamic horizontal abduction repetitions to muscular failure using a load equating to approximately 75% body weight. The order of performance of the hand positions was counterbalanced between participants so that approximately half of the subjects performed PRO first and the other half performed NEU first. Surface electromyography was used to record both mean and peak muscle activity of the posterior deltoid, middle deltoid, and infraspinatus. Results showed that mean EMG activity for the posterior deltoid was significantly greater in NEU compared to PRO (p = 0.046; 95% CI = 0.1 to 7.4% MVIC). Similarly, mean EMG activity of the infraspinatus also was significantly greater in NEU compared to PRO (p = 0.002; 95% CI = 3.7 to 13.6% MVIC). The results of this study show that performing exercise on the reverse fly machine with a neutral hand position significantly increases activity of the posterior deltoid and infraspinatus muscles compared to a pronated hand position.

Concepts: Muscle, Mass, Body mass index, Electromyography, Shoulder, Rotator cuff, Deltoid muscle, Glenohumeral joint

30

Study Design Case report. Background Prognosis for adhesive capsulitis has been described as self-limiting and can persist for 1-3 years. Conservative treatment including physical therapy is commonly advised. Case Description The patient was a 54 year old female with primary symptoms of shoulder pain and loss of motion consistent with adhesive capsulitis. Manual physical therapy intervention initially consisted of joint mobilizations of the shoulder region and thrust manipulation of the cervicothoracic region. Although manual techniques seemed to cause some early functional improvement, continued progression was limited by pain. Subsequent examination identified trigger points in the upper trapezius, levator scapula, deltoid and infraspinatus muscles that were treated with dry needling to decrease pain and allow for higher grades of manual intervention. Outcomes The patient was treated for a total of 13 visits over a 6 weeks period. After trigger point dry needling was introduced on the third visit, improvements in pain-free shoulder range of motion and functional outcome measures, including SPADI and QuickDASH, exceeded the minimal clinically important difference after 2 treatment sessions. At discharge the patient had achieved significant improvements in shoulder range of motion in all planes and outcome measures were significantly improved. Discussion This case report describes the clinical reasoning behind the use of trigger point dry needling in the treatment of a patient with adhesive capsulitis. The rapid improvement seen in this patient following the initiation of dry needling to the upper trapezius, levator scapula, deltoid and infraspinatus muscles suggests that surrounding muscles may be a significant source of pain in this condition. Level of Evidence Therapy, level 4. J Orthop Sports Phys Ther, Epub 21 November 2013. doi:10.2519/jospt.2014.4915.

Concepts: Improve, Injuries, Acupuncture, Shoulder, Massage, Supraspinatus muscle, Clavicle, Trigger point