Aims. Rotator cuff (RC) injuries are characterized by tendon rupture, muscle atrophy, retraction, and fatty infiltration, which increase injury severity and jeopardize adequate tendon repair. Epigenetic drugs, such as histone deacetylase inhibitors (HDACis), possess the capacity to redefine the molecular signature of cells, and they may have the potential to inhibit the transformation of the fibro-adipogenic progenitors (FAPs) within the skeletal muscle into adipocyte-like cells, concurrently enhancing the myogenic potential of the satellite cells. Methods. HDACis were added to FAPs and satellite cell cultures isolated from mice. The HDACi vorinostat was additionally administered into a RC injury
Introduction. The pathogenesis of rotator cuff disease (RCD) is complex and
not fully understood. This systematic review set out to summarise
the histological and molecular changes that occur throughout the
spectrum of RCD. Methods. We conducted a systematic review of the scientific literature
with specific inclusion and exclusion criteria. Results. A total of 101 studies met the inclusion criteria: 92 studies
used human subjects exclusively, seven used
Rotator cuff (RC) tears are common musculoskeletal injuries which often require surgical intervention. Noninvasive pulsed electromagnetic field (PEMF) devices have been approved for treatment of long-bone fracture nonunions and as an adjunct to lumbar and cervical spine fusion surgery. This study aimed to assess the effect of continuous PEMF on postoperative RC healing in a rat RC repair model. A total of 30 Wistar rats underwent acute bilateral supraspinatus tear and repair. A miniaturized electromagnetic device (MED) was implanted at the right shoulder and generated focused PEMF therapy. The animals’ left shoulders served as controls. Biomechanical, histological, and bone properties were assessed at three and six weeks.Aims
Methods
Traumatic brachial plexus injury causes severe functional impairment
of the arm. Elbow flexion is often affected. Nerve surgery or tendon
transfers provide the only means to obtain improved elbow flexion.
Unfortunately, the functionality of the arm often remains insufficient.
Stem cell therapy could potentially improve muscle strength and
avoid muscle-tendon transfer. This pilot study assesses the safety
and regenerative potential of autologous bone marrow-derived mononuclear
cell injection in partially denervated biceps. Nine brachial plexus patients with insufficient elbow flexion
(i.e., partial denervation) received intramuscular escalating doses
of autologous bone marrow-derived mononuclear cells, combined with
tendon transfers. Effect parameters included biceps biopsies, motor
unit analysis on needle electromyography and computerised muscle tomography,
before and after cell therapy.Objectives
Methods
Local corticosteroid infiltration is a common practice of treatment
for lateral epicondylitis. In recent studies no statistically significant
or clinically relevant results in favour of corticosteroid injections
were found. The injection of autologous blood has been reported
to be effective for both intermediate and long-term outcomes. It
is hypothesised that blood contains growth factors, which induce
the healing cascade. A total of 60 patients were included in this prospective randomised
study: 30 patients received 2 ml autologous blood drawn from contralateral
upper limb vein + 1 ml 0.5% bupivacaine, and 30 patients received
2 ml local corticosteroid + 1 ml 0.5% bupivacaine at the lateral
epicondyle. Outcome was measured using a pain score and Nirschl
staging of lateral epicondylitis. Follow-up was continued for total
of six months, with assessment at one week, four weeks, 12 weeks
and six months.Objectives
Methods
This study reports the application of a novel method for quantitatively determining differences in the mechanical properties of healthy and torn rotator cuff tissues. In order to overcome problems of stress risers at the grip-tendon interface that can obscure mechanical measurements of small tendons, we conducted our investigation using dynamic shear analysis. Rotator cuff tendon specimens were obtained from 100 patients during shoulder surgery. They included 82 differently sized tears and 18 matched controls. We subjected biopsy samples of 3 mm in diameter to oscillatory deformation under compression using dynamic shear analysis. The storage modulus (G’) was calculated as an indicator of mechanical integrity. Normal tendons had a significantly higher storage modulus than torn tendons, indicating that torn tendons are mechanically weaker than normal tendons (p = 0.003). Normal tendons had a significantly higher mean shear modulus than tendons with massive tears (p <
0.01). Dynamic shear analysis allows the determination of shear mechanical properties of small tissue specimens obtained intra-operatively that could not be studied by conventional methods of tensile testing. These methods could be employed to investigate other musculoskeletal tissues. This pilot study provides some insight into mechanisms that might contribute to the failure of repair surgery, and with future application could help direct the most appropriate treatment for specific rotator cuff tears.
This study examined the role of vitamin D as a factor accounting for fatty degeneration and muscle function in the rotator cuff. There were 366 patients with disorders of the shoulder. A total of 228 patients had a full-thickness tear (group 1) and 138 patients had no tear (group 2). All underwent magnetic resonance arthrography and an isokinetic muscle performance test. The serum concentrations of vitamin D (25(OH)D3) were measured. In general, a lower serum level of vitamin D was related to higher fatty degeneration in the muscles of the cuff. Spearman’s correlation coefficients were 0.173 (p = 0.001), −0.181 (p = 0.001), and −0.117 (p = 0.026) for supraspinatus, infraspinatus and subscapularis, respectively. In group 1, multivariate linear regression analysis revealed that the serum level of vitamin D was an independent variable for fatty degeneration of the supraspinatus and infraspinatus. The serum vitamin D level has a significant negative correlation with the fatty degeneration of the cuff muscle and a positive correlation with isokinetic muscle torque.
