Tomoyuki Muto

Platelet-rich plasma protects rotator cuff-derived cells from the deleterious effects of triamcinolone acetonide.

Triamcinolone acetonide (TA) injections are widely used to treat enthesopathy, but they may induce adverse effects such as tendon impairment and rupture. Platelet‐rich plasma (PRP) is a blood fraction containing high platelet concentrations and various growth factors that play a role in tissue repair processes. The purpose of this study is to investigate whether TA has deleterious effects on human rotator cuff‐derived cells, and if PRP can protect these cells from the effects of TA. Human rotator cuff‐derived cells were cultured with and without TA and PRP, and the culture without any additive served as the control. Cell morphology was assessed at days 7 and 21. Cell viability was evaluated at days 1, 7, 14, and 21 by a water‐soluble tetrazolium salt assay. Induction of apoptosis was measured by immunofluorescence staining and flow cytometry at day 7. Induction of cleaved caspase‐3 was measured by immunofluorescence staining at day 7. The cells cultured with TA had a flattened and polygonal shape at day 7. The cells cultured with both TA and PRP were similar in appearance to control cells. Exposure to TA also significantly decreased cell viability, but cell viability did not decrease when PRP was added along with TA. The number of apoptotic cells increased with TA exposure, while addition of PRP prevented cell apoptosis. In conclusion, the deleterious effect of TA was prevented by PRP, which can be used as a protective agent for patients receiving local TA injections.

Temporary inductions of matrix metalloprotease‐3 (MMP‐3) expression and cell apoptosis are associated with tendon degeneration or rupture after corticosteroid injection

Corticosteroid injections are widely used to treat enthesopathy and tendinitis, but are also associated with possible side effects, such as tendon degeneration or rupture. However, the mechanism of tendon degeneration or rupture after corticosteroid injection remains controversial. The purpose of this study was to reveal the mechanism of tendon degeneration or rupture after injection of triamcinolone acetonide (TA) or prednisolone (PSL). Forty‐two rats were divided into 3 groups: A normal saline injection group (control group), a TA injection group, and a PSL injection group; the normal saline or corticosteroid was injected around the Achilles tendon. One or 3 weeks after injection, the tendons were subjected to biomechanical testing and histological analysis. At 1 week, the biomechanical strength was significantly lower in the corticosteroid groups. Histological analysis, at 1‐week post‐injection, showed collagen attenuation, increased expression of MMP‐3 and apoptotic cells in the corticosteroid groups. The histological changes and biomechanical weaknesses of the tendon were not seen at 3 weeks. These alterations appeared to be involved in tendon degeneration or rupture after corticosteroid injection.

Concurrent Rotator Cuff Tear and Axillary Nerve Palsy Associated with Anterior Dislocation of the Shoulder and Large Glenoid Rim Fracture: A “Terrible Tetrad”

We present a case of concurrent rotator cuff tear and axillary nerve palsy resulting from anterior dislocation of the shoulder and a large glenoid rim fracture—a “terrible tetrad.” A 61-year-old woman fell on her right shoulder. Radiographs showed anterior dislocation of the shoulder with a glenoid rim fracture, and an MRI two months after injury revealed a rotator cuff tear. Upon referral to our hospital, physical and electrophysiological examinations revealed axillary nerve palsy. The axillary nerve palsy was incomplete and recovering, and displacement of the glenoid rim fracture was minimal and already united; therefore, we surgically repaired only the rotator cuff tear three months after injury. The patient recovered satisfactorily following the operation. In patients whose axillary nerve palsy is recovering, surgeons should consider operating on rotator cuff tears in an attempt to prevent rotator cuff degeneration.

Rotator cuff repair using cell sheets derived from human rotator cuff in a rat model

To achieve biological regeneration of tendon‐bone junctions, cell sheets of human rotator‐cuff derived cells were used in a rat rotator cuff injury model. Human rotator‐cuff derived cells were isolated, and cell sheets were made using temperature‐responsive culture plates. Infraspinatus tendons in immunodeficient rats were resected bilaterally at the enthesis. In right shoulders, infraspinatus tendons were repaired by the transosseous method and covered with the cell sheet (sheet group), whereas the left infraspinatus tendons were repaired in the same way without the cell sheet (control group). Histological examinations (safranin‐O and fast green staining, isolectin B4, type II collagen, and human‐specific CD31) and mRNA expression (vascular endothelial growth factor; VEGF, type II collagen; Col2, and tenomodulin; TeM) were analyzed 4 weeks after surgery. Biomechanical tests were performed at 8 weeks. In the sheet group, proteoglycan at the enthesis with more type II collagen and isolectin B4 positive cells were seen compared with in the control group. Human specific CD31‐positive cells were detected only in the sheet group. VEGF and Col2 gene expressions were higher and TeM gene expression was lower in the sheet group than in the control group. In mechanical testing, the sheet group showed a significantly higher ultimate failure load than the control group at 8 weeks. Our results indicated that the rotator‐cuff derived cell sheet could promote cartilage regeneration and angiogenesis at the enthesis, with superior mechanical strength compared with the control. Treatment for rotator cuff injury using cell sheets could be a promising strategy for enthesis of tendon tissue engineering.

Dose- and time-dependent effects of triamcinolone acetonide on human rotator cuff-derived cells

Objectives To investigate the appropriate dose and interval for the administration of triamcinolone acetonide (TA) in treating tendinopathy to avoid adverse effects such as tendon degeneration and rupture. Methods Human rotator cuff-derived cells were cultured using three media: regular medium (control), regular medium with 0.1 mg/mL of TA (low TA group), and with 1.0 mg/mL of TA (high TA group). The cell morphology, apoptosis, and viability were assessed at designated time points. Results In the low TA group, the cells became flattened and polygonal at seven days then returned to normal at 21 days. The cell apoptosis ratio and messenger ribonucleic acid expression of caspase-3, 7, 8, and 9 increased, and viability was reduced in the low and high groups at seven days. In the low TA group, apoptosis and viability returned to normal at 21 days, however, in the high TA group, the cell morphology, apoptosis ratio, caspase-3, 7, 8, and 9 and viability did not return by day 21. Re-administration was performed in the low TA group at 7-, 14-, and 21-day intervals, and cell viability did not return to the control level at the 7- and 14-day intervals. Conclusion A 0.1 mg/mL dose of TA temporarily decreased cell viability and increased cell apoptosis, which was recovered at 21 days, however, 1 mg/mL of TA caused irreversible damage to cell morphology and viability. An interval > three weeks was needed to safely re-administer TA. These findings may help determine the appropriate dose and interval for TA injection therapy. Cite this article: Bone Joint Res 2014;3:328–34.

The effect of platelet-rich plasma on degeneration change of rotator cuff muscles: In vitro and in vivo evaluations†

Atrophy with fatty degeneration is often seen in rotator cuff muscles with torn tendons. PRP has been reported to enhance tissue repair processes after tendon ruptures. However, the effect of PRP on atrophy and fatty degeneration of the muscle is not yet known. The aim of this study is to examine the effect of PRP on degeneration change of rotator cuff muscles in vitro and in vivo. A murine myogenic cell line and a rat rotator cuff tear model were used in this study and PRP was administrated into subacromial space which is widely used in clinical practice. In in vitro study, administration of PRP to C2C12 cells stimulated cell proliferation while inhibited both myogenic and adipogenic differentiation. In in vivo study, administration of PRP suppressed Oil Red‐O positive lipid droplet formation. The expression of adipogenic genes was also decreased by PRP administration. In conclusion, PRP promoted proliferation of myoblast cells, while inhibiting adipogenic differentiation of myoblast cells and suppressing fatty degeneration change in rat torn rotator cuff muscles. Further investigations are needed to determine the clinical applicability of the PRP.

Effects of platelet-rich plasma and triamcinolone acetonide on interleukin-1ß-stimulated human rotator cuff-derived cells

Objectives Triamcinolone acetonide (TA) is widely used for the treatment of rotator cuff injury because of its anti-inflammatory properties. However, TA can also produce deleterious effects such as tendon degeneration or rupture. These harmful effects could be prevented by the addition of platelet-rich plasma (PRP), however, the anti-inflammatory and anti-degenerative effects of the combined use of TA and PRP have not yet been made clear. The objective of this study was to determine how the combination of TA and PRP might influence the inflammation and degeneration of the rotator cuff by examining rotator cuff-derived cells induced by interleukin (IL)-1ß. Methods Rotator cuff-derived cells were seeded under inflammatory stimulation conditions (with serum-free medium with 1 ng/ml IL-1ß for three hours), and then cultured in different media: serum-free (control group), serum-free + TA (0.1mg/ml) (TA group), serum-free + 10% PRP (PRP group), and serum-free + TA (0.1mg/ml) + 10% PRP (TA+PRP group). Cell morphology, cell viability, and expression of inflammatory and degenerative mediators were assessed. Results Exposure to TA significantly decreased cell viability and changed the cell morphology; these effects were prevented by the simultaneous administration of PRP. Compared with the control group, expression levels of inflammatory genes and reactive oxygen species production were reduced in the TA, PRP, and TA+PRP groups. PRP significantly decreased the expression levels of degenerative marker genes. Conclusions The combination of TA plus PRP exerts anti-inflammatory and anti-degenerative effects on rotator cuff-derived cells stimulated by IL-1ß. This combination has the potential to relieve the symptoms of rotator cuff injury. Cite this article: T. Muto, T. Kokubu, Y. Mifune, A. Inui, R. Sakata, Y. Harada, F. Takase, M. Kurosaka. Effects of platelet-rich plasma and triamcinolone acetonide on interleukin-1ß-stimulated human rotator cuff-derived cells. Bone Joint Res 2016;5:602–609. DOI: 10.1302/2046-3758.512.2000582.

Influence of Combinations of Shoulder, Elbow and Trunk Orientation on Elbow Joint Loads in Youth Baseball Pitchers:

Objectives: Shoulder and elbow pain in youth baseball pitchers is a well-recognized phenomenon. Common problems in pitching mechanics that can lead to injury begin with stride foot contact. The purpose of this study was to address the relationships between the combinations of shoulder, elbow and trunk orientation at the instant of stride foot contact and elbow joint loads in youth baseball pitchers. Methods: A total of 143 Japanese male youth baseball pitchers participated in this study after providing written informed consents approved by the hospital’s institutional review board. The procedures to be performed were also explained to their parent(s) or legal guardian(s). Each participant was not currently injured or recovering from an injury at time of testing. For data collection of baseball pitching, a set of 14-mm spherical reflective markers was placed on the skin overlying 34 anatomical landmarks determined. Subsequently, a motion capture three-dimensional automatic digitizing system was used to collect 500-Hz from 7 charge-coupled-device synchronized cameras was set up around the regulation pitching mound in an indoor laboratory. After performing a preparation routine of stretching and warm-up pitching, each player pitch to 5 fastball pitches off the pitching mound to a catcher at the regulation distance of 16 m for youth pitchers. The best pitch thrown for a strike was chosen for kinematic and kinetic analysis. The local coordinate systems were used to calculate 3-dimesional rotation at the trunk, shoulder and elbow using the typical Eulerian sequence. Afterward, the standard inverse dynamic equation was used to estimate resultant joint forces and torques at throwing shoulder and elbow. In order to normalize data between subjects, forces and torques were expressed as percent using body weight and height. A multiple regression analysis was carried out to assess the combined effects of shoulder (external rotation, abduction and horizontal adduction), elbow (pronation and extension) and trunk (extension, contralateral tilt, rotation) orientation at SFC and the onset time of trunk rotation on elbow joint loads at SFC. The onset time of trunk rotation was defined as the event in which the magnitude of trunk rotation begins to decrease from tis maximum value. Results: The peak medial force of the elbow was significant correlated with the peak internal rotation torque of the shoulder and the peak varus torque of the elbow (Figure 1). The medial force of the elbow at SFC was significantly correlated with the peak medial force of the elbow (r = .41, p < .001). The adjusted multiple R2 value was 0.45, indicating that over 45% of the variance in the medial force of the elbow at SFC was explained by the regression equation. The standard error of estimate was 4.34. All 3 of the regression variables were significant and are shown in Table 1. Conclusion: The combinations of the greater external rotation of the shoulder, contralateral trunk tilt and elbow extension at SFC may have an indirect influence on the peak medial force on the elbow (Table 1). Then the peak elbow varus torque and shoulder internal rotation torque lead to increase as a result of these. These biomechanical data provide a scientific basis for clinicians, athletes, and coaches to establish methods to prevent pitching-related injuries and improve pitching mechanics.

Application of Pain Quantitative Analysis Device for Assessment of Postoperative Pain after Arthroscopic Rotator Cuff Repair

Purpose : The PainVision™ system was recently developed for quantitative pain assessment. Here, we used this system to evaluate the effect of plexus brachialis block on postoperative pain after arthroscopic rotator cuff repair. Methods : Fifty-five patients who underwent arthroscopic rotator cuff repair were included in this study. First 26 cases received no plexus brachialis block (control group), and the next 29 cases received the plexus brachialis block before surgery (block group). Patients completed the visual analog scale at 4, 8, 16, and 24 hours after surgery, and the intensity of postoperative pain was assessed with PainVision™ at 16 hours. The postoperative use of non-steroidal anti-inflammatory agents was also recorded. Results : The pain intensity at 16 hours after surgery assessed by PainVision™ was significantly lower in the block group than in the control group (block, 252.0 ± 47.8, control, 489.0 ± 89.1, P < 0.05). However, there were no differences in the VAS values at 16 hours between the 2 groups (block, 4.3 ± 0.6, control, 5.7 ± 0.4, P = N.S.). The pain intensity and VAS at 16 hours after surgery were highly correlated (r = 0.59, P = 0.006 in the block group and r = 0.62, P = 0.003 in the control group). The effect size of the assessment by PainVision™ was bigger than that of VAS (r=0.31 in VAS and 0.51 in Pain vision). Conclusion : The PainVision™ system could be useful to evaluate postoperative pain because it enables the quantification and comparison of pain intensity independent of individual pain thresholds.

Can Platelet-Rich Plasma Protect Rat Achilles Tendons From the Deleterious Effects of Triamcinolone Acetonide?

Background Triamcinolone acetonide (TA) injections are widely used for tendinitis but have deleterious effects, including tendon degeneration or tendon rupture. Purpose To investigate whether adding platelet-rich plasma (PRP), a blood fraction that participates in tissue repair processes, to TA can prevent its deleterious effects. Study Design Controlled laboratory study. Methods Rat Achilles tendons were injected with TA, TA + PRP, PRP alone, or saline (control). Biomechanical testing and histological analyses were performed on Achilles tendons 1 week after injections. Results The maximum failure loads in the control, TA, TA + PRP, and PRP groups were 31.7 ± 2.3, 19.0 ± 3.6, 31.0 ± 7.1, and 30.2 ± 6.8 N, respectively. The tendon stiffness in the control, TA, TA + PRP, and PRP groups was 12.1 ± 1.8, 7.5 ± 1.8, 11.0 ± 2.8, and 11.3 ± 2.5 N/mm, respectively. The maximum failure load and stiffness were significantly lower in the TA group compared with the other 3 groups. There was no significant difference between the TA + PRP and control groups. Cell invasions, vacuolation, collagen attenuation, and increased type III collagen expression were histologically observed in the TA group; however, these changes were prevented by the simultaneous administration of PRP. Conclusion Administering PRP may prevent deleterious effects caused by TA; therefore, PRP may be used as a protective agent in clinical situations. Clinical Relevance PRP can be useful as a protective agent for sports injury patients receiving local corticosteroid injections.