Anti-inflammatory management for tendon injuries - friends or foes?

Acute and chronic tendon injuries are very common among athletes and in sedentary population. Most physicians prescribe anti-inflammatory managements to relieve the worst symptoms of swelling and pain, including non-steroidal anti-inflammatory drugs, corticosteroids and physical therapies. However, experimental research shows that pro-inflammatory mediators such as prostaglandins may play important regulatory roles in tendon healing. Noticeably nearly all cases of chronic tendon injuries we treat as specialists have received non-steroidal anti-inflammatory drugs by their physician, suggesting that there might be a potential interaction in some of these cases turning a mild inflammatory tendon injury into chronic tendinopathy in predisposed individuals. We are aware of the fact that non-steroidal anti-inflammatory drugs and corticosteroids may well have a positive effect on the pain control in the clinical situation whilst negatively affect the structural healing. It follows that a comprehensive evaluation of anti-inflammatory management for tendon injuries is needed and any such data would have profound clinical and health economic importance

Effectiveness of insoles on plantar pressure redistribution

Author name used in this publication: Arthur Fuk Tat Mak2004-2005 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

The effect of glucocorticoids on tendon cell viability in human tendon explants

Background and purpose Previous studies on the culture of human tenocytes have shown that dexamethasone and triamcino-lone reduce cell viability, suppress cell proliferation, and reduce collagen synthesis. However, such cell cultures lack the extracellular matrix and three-dimensional structure of normal tendons, which affects their response to stimuli. We established a human tendon explant culture system and tested the effects of dexamethasone and triamcinolone on cell viability

Grafted tendon healing in tibial tunnel is inferior to healing in femoral tunnel after anterior cruciate ligament reconstruction: a histomorphometric study in rabbits

PURPOSE: This study aimed to test whether graft healing in the tibial tunnel was inferior to that in the femoral tunnel after anterior cruciate ligament (ACL) reconstruction in rabbits. METHODS: Surgical reconstruction by use of the digital extensor tendon in the bone tunnel was performed in 18 rabbits. The rabbits were killed at weeks 2, 6, and 12 postoperatively, with 6 at each time point, for histologic examination. RESULTS: The transiently formed cartilaginous interface was gradually mineralized during re-establishment of direct tendon-to-bone integration, which was observed significantly less in the tibial tunnel than in the femoral tunnel (P < .05). The cell density of the graft was significantly lower in the tibial tunnel than that in the femoral tunnel at weeks 2 and 6 postoperatively (P < .05 for both). An increase in the immature type III collagen content was accompanied by a decrease in graft collagen fiber organization, with healing over time in both the femoral and tibial tunnels. The collagen fiber organization of the graft was significantly poorer in the tibial tunnel than that in the femoral tunnel at week 12 after surgery (P < .05). CONCLUSIONS: Grafted tendon healing in the tibial tunnel was inferior to that in the femoral tunnel at the tendon-to-bone interface and with regard to the grafted tendon within the bone tunnel after ACL reconstruction in rabbits. CLINICAL RELEVANCE: Future biopsy study is desirable to test whether this observation was valid clinically, which might provide a scientific basis for therapeutic targets to improve the outcome of ACL surgery.link_to_subscribed_fulltex

Influence of bone adaptation on tendon-to-bone healing in bone tunnel after anterior cruciate ligament reconstruction in a rabbit model

Anterior cruciate ligament (ACL) reconstruction with placement of grafted tendon in bone tunnel is a common surgical procedure. Bone tunnel creation may result in stress shielding of postero-lateral regions of tibial tunnel. The present study was designed to characterize the changes of peri-graft bone and compare with tendon-to-bone (T-B) healing in spatial and temporal manners after ACL reconstruction in rabbit. Surgical reconstruction using digital extensor tendon in bone tunnel was performed on 48 rabbits. Twelve rabbits were sacrificed at 0, 2, 6, and 12 weeks postoperatively for radiological and histological examinations. Bone mass and microarchitecture at the anterior, posterior, medial, and lateral regions of tunnel wall at distal femur and proximal tibia were evaluated. Using peripheral quantitative computed tomography, a 26, 22, and 42% decrease in bone mineral density (BMD) relative to baseline was present in the medial region of the femoral tunnel and the posterior and lateral regions of the tibial tunnel, respectively, at week 12 postoperatively (p < 0.05). It was accompanied by a decrease in trabecular number and increase in trabecular spacing, the shift of platelike to rodlike trabeculae, and loss of anisotropy under micro-computed tomography evaluation. This finding was echoed by histology showing increased osteoclastic activities and poor T-B healing in these regions. In conclusion, the postoperative bone loss and associated poor T-B healing was region-dependent, which may result from adaptive changes after tunnel creation.link_to_subscribed_fulltex

Effect of dexamethasone on cultured human tenocytes and its reversibility by platelet-derived growth factor

Background: Many cases of tendon rupture after glucocorticoid injections have been reported in the literature. Despite previous studies on the histological and biomechanical changes in tendons after glucocorticoid injections, the role of glucocorticoid in causing tendon rupture still remains controversial. The objective of this study was to determine whether glucocorticoid has deleterious effects on the cellular metabolism and collagen production of cultured human tenocytes and the reversibility of these effects by platelet-derived growth factor-BB (PDGFBB). Methods: Primary cultures of human tenocytes obtained from explants of healthy patellar tendon, harvested during anterior cruciate ligament reconstructions, were performed. The effects on cell viability, cell proliferation, and induction of apoptosis were measured by [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay, 5-bromo-deoxyuridine incorporation, and DNA fragmentation assay, respectively. The effect on collagen synthesis was measured by 3H-proline incorporation assay. Results: The number of viable cells was decreased, in a dose-dependent manner, by the administration of 10 -9 to 10-4-M dexamethasone. This dose range also suppressed cell proliferation. No apoptotic effect was detected. Treatment with 10-6-M dexamethasone significantly reduced the amount of collagen synthesis. Co-incubation with 10 ng/mL of PDGFBB significantly reversed the effects caused by 10-6-M dexamethasone. Conclusions: Dexamethasone significantly decreased cell viability, suppressed cell proliferation, and reduced collagen synthesis in cultured human tenocytes. The effects were reversed by the simultaneous administration of PDGFBB. Clinical Relevance: The current study demonstrates that glucocorticoids adversely affect human tenocytes in cell culture. As the effects are reversible with simultaneous administration of PDGFBB, the growth factor may be useful clinically as a protective agent for patients receiving local glucocorticoid injections.link_to_subscribed_fulltex