Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “TENDONS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 901 records · Page 50Linked to original sources
PubMed1988

Kinetics and kinematics of the equine hind limb: in vivo tendon loads and force plate measurements in ponies.

Loads on the suspensory ligament, deep digital flexor tendon, superficial digital flexor tendon, and long digital extensor tendon of the equine hind limb were determined in ponies by use of implanted strain gauges consisting of silicone rubber tubes filled with mercury. Recordings were made simultaneously with force plate measurements and high-speed film recordings while the ponies were walking. The relationship between strain gauge signals and tendon loads was obtained from tension-strain tests performed after death of the ponies. The suspensory ligament and the 2 digital flexor tendons were loaded during the stance phase, and the extensor tendon was loaded mainly during the swing phase. The loading pattern of the suspensory ligament, with peak loads of 4.6 N/kg of body weight, correlated well with the vertical component of the ground reaction force. Maximal loading of the deep digital flexor tendon was observed during the second half of the stance phase, with peak values of 6.7 N/kg. The superficial digital flexor tendon was loaded maximally at the beginning of the stance phase, with a peak load of 4.1 N/kg, and the long digital extensor tendon was loaded maximally during the swing phase, with a peak load of 0.3 N/kg. Recordings made from this procedure for calibration of the strain gauge signals to tendon load and tendon strain, in combination with the force plate measurements, enabled verification of the results by torque analysis of the lower portion of the hind limb, using the vector of the ground reaction force, limb conformation, and limb geometric configuration. Torque analysis of the lower extremity indicated that the determined tendon loads were in agreement with the recorded ground reaction forces.

Animals↗
PubMed1996

Tenascin-C and human tendon degeneration.

We investigated the distribution of tenascin in supraspinatus tendons to determine whether an alteration in tenascin expression was associated with human tendon degeneration. Tenascin was present in all of the tendons studied, although with two distinct patterns of expression. First, tenascin was associated with organized, fibrous regions of the tendon matrix that were typical of the normal tendon structure. This distribution is consistent with a role for tenascin in collagen fibril organization, perhaps maintaining the interface between fibrils and adjacent structures. Second, although tenascin was generally absent from poorly organized matrix in degenerate tendons, it was strongly associated with some rounded cells in disorganized fibrocartilaginous regions that were more abundant in pathological specimens. Tenascin was also found around infiltrating blood vessels, with more intense staining associated with a mononuclear cell infiltrate. Western blotting of tendon extracts showed differences in tenascin isoform expression, with only the small (200-kd) tenascin isoform found in normal tendons. Degenerate tendons also expressed the 300-kd isoform, consistent with a role for the larger tenascin isoform in tendon disease, potentially stimulating tenocyte proliferation, cell rounding, and fibrocartilaginous change. Proteolytic fragments of tenascin were detected but only in ruptured tendons, an indication of matrix remodeling in degenerate tendons, with fragment sizes consistent with the activity of matrix metalloproteinase enzymes.

Adult↗
PubMed2000

[Quadriceps and patellar tendon ruptures].

Ruptures of the quadriceps as well as the patellar tendon occur in low frequency, but cause major functional deficits of the leg. These injuries usually require operative treatment. Acute quadriceps tendon ruptures are treated by suture repair, using heavy sutures guided through bone tunnels in the patella. Chronic defects and neglected cases require a local tendon transfer, either by a quadriceps tendon turn-down or by a V-Y-plasty of the quadriceps tendon. Ruptures of the patellar tendon are treated by suture of the tendon stumps plus an reinforcement procedure protecting the tendon and avoiding secondary patella alta. Patello-tibial fixation may be achieved by a cerclage technique using wire or an autologous tendon strip, alternatively a patello-tibial external fixator can be applied. In chronic and neglected cases, patellar tendon reconstruction is performed with autologous tendon grafts or with soft tissue allografts. The graft must be protected by a patello-tibial fixation for the first weeks.

Acute Disease↗
PubMed1996

Proteoglycans of human rotator cuff tendons.

Rotator cuff and biceps tendons that appeared grossly normal were procured from adult cadavers without a history of shoulder problems. These tendons were analyzed for the amount and type of glycosaminoglycan, type of proteoglycan, and histology. When compared with the distal/tensional region of biceps tendon, the glycosaminoglycan content of supraspinatus, infraspinatus, and subscapularis tendons was 2.5-fold higher and the glycosaminoglycan content of the proximal/compressed region of biceps tendon was 3-fold higher. The ratio of hyaluronic acid to chondroitin sulfate/dermatan sulfate in all three cuff tendons was approximately 1. Rotator cuff tendons contained large proteoglycan similar to aggrecan, as demonstrated by sodium dodecyl sulfate-polyacrylamide gel migration elution from Sepharose CL-4B, and content of both chondroitin sulfate and keratan sulfate chains. Both decorin and biglycan were also present, as demonstrated by migration in sodium dodecyl sulfate-polyacrylamide gels and core protein immunoreactivity. In contrast decorin was the only proteoglycan prominent in distal/tensional regions of biceps tendon. Histological analysis showed layers of loosely organized alcian blue-stained material running between the longitudinal collagen fiber bundles. The proteoglycan content of rotator cuff tendons was similar to fibrocartilage in tendons that have been subjected to compressive loads in situ. This suggests that cells of normal adult rotator cuff tendons have adapted to loads distinct from pure tension. However, the histological organization did not resemble mature fibrocartilage. The increased amount of proteoglycan in rotator cuff tendons may serve to separate and lubricate collagen bundles as they move relative to each other during normal shoulder motion.

Adult↗
PubMed1997

Patella position and biomechanical properties of the patellar tendon 1 year after removal of its central third.

OBJECTIVE: The aim of this study was to investigate how the removal of a patellar tendon graft for cruciate ligament reconstruction influences the mechanical properties of the remaining patellar tendon and the position of the patella at the knee joint. DESIGN: The experimental model of this in vivo study was the anterior cruciate ligament reconstruction in sheep. BACKGROUND: While the efficacy of a patellar tendon third as a ligament replacement has been extensively investigated, the consequences for the function of the remaining tendon and patella position remain unclear. METHODS: The central third of the patellar tendon from the right knees of 10 animals was removed for cruciate ligament replacement. One year postoperatively, the position of the patella within the joint and the stiffness and modulus of elasticity of the remaining tendon were compared with the non-operated contralateral controls. RESULTS: The patella position did not change in the operated knee joints in comparison with the controls. The cross-sectional area of the operated patellar tendon increased significantly by scar tissue formation at the defect site. CONCLUSION: Although the inferior mechanical properties of the scar tissue reduced the modulus of, elasticity of the tendon, the increase in cross-sectional area allowed it to develop a structural stiffness similar to the control tendons. RELEVANCE: The central third of the patellar tendon is often used for ligament replacement. Resulting biomechanical and structural changes in the remaining patellar tendon have not been previously reported using an in vivo animal model. The recovery of the biomechanical properties of the partially resected tendons allows for continued function.

Journal Article↗
PubMed2002

The effects of polyester (terylene) fibre implants on normal equine superficial digital flexor tendon.

AIM: To determine the effect of polyester (terylene) fibre implants on normal equine superficial digital flexor (SDF) tendon structure. METHODS: Normal forelimb SDF tendons (n=24) of 12 horses were divided into unoperated, sham-operated, and implanted (terylene fibre implant) groups. Horses were assessed for lameness and ultrasonographic changes to SDF tendons at intervals up to 48 weeks post-operatively. After euthanasia, SDF tendons were collected for histological and ultrastructural examination. Histological sections were examined for alcian blue staining intensity, cellularity, fibril bundle alignment, fascicle separation and crimp morphology. Mass-average diameters (MADs) of collagen fibrils were calculated from electron micrographs and compared between treatment groups. RESULTS: Insertion of terylene fibre implants resulted in short-term (8 weeks) lameness in implanted limbs. Ultrasonographically, the implants could be detected in 50% of implanted tendons, but were associated with tendon swelling and the presence of hypoechoic core lesions in 7/8 implanted limbs. There were significant alterations in alcian blue staining, cellularity and crimp morphology in the central fascicles of sham-operated and implanted tendons, and alteration in fibril alignment in the central fascicles of implanted tendons. Unoperated tendons remained histologically normal. MADs of collagen fibrils did not differ between sham-operated, implanted and unoperated limbs. CONCLUSIONS: Both the sham procedure and the insertion of terylene fibre implants led to alterations in tendon structure that persisted for up to 48 weeks. Persistence of disorganised connective tissue at the proximal and distal ends of the terylene fibre implants may predispose implanted tendons to continued risk of injury. CLINICAL RELEVANCE: It is unlikely that terylene fibre implants offer any advantage over standard non-surgical treatments for mild to moderate cases of SDF tendonitis in the horse.

Journal Article↗
PubMed1990

Collagen synthesis during primate flexor tendon repair in vitro.

The concept that flexor tendons have the intrinsic capacity to participate actively in the repair process following laceration has been developed in recent years as the result of experimental studies from numerous laboratories. However, the role of the outer/epitenon and inner/endotenon cell populations with regard to protein synthesis is still controversial. The purpose of this study was to investigate the respective participation of these tendon fibroblast populations in the synthesis of the collagen matrix during in vitro repair of the flexor tendon from nonhuman primates, utilizing immunohistochemical techniques and a Type I procollagen antibody. Zone II profundus flexor tendon segments were obtained from young adult Macaca nemestrina monkeys. One centimeter segments were cultured, either with or without a transverse laceration across 90% of the midsection of the tendon segment. Frozen sections of the cultured tendon segments were reacted with the (mouse monoclonal) Type I procollagen antisera. At all times of culture of the nonlacerated tendon segment, only a few of the epitenon cells along the surface of the tendon and distant from the cut end stained positively for active collagen synthesis. In the lacerated segments, and as early as 9 days of culture and repair, the procollagen reaction product was starting to appear in those cells of the outer epitenon cell layer. These studies support the concept that the inner fibroblasts do actively participate in collagen production. However, it now also appears that a significant degree of collagen synthesis during tendon repair resides in the outer/epitenon layer of cells enveloping the tendon segment, and that the repair response of the flexor tendon in vitro is proportional to the degree of injury.

Animals↗
PubMed2006

Effect of wrist and ulna head position on gliding resistance of the extensor digitorum minimi and extensor digitorum communis III tendons: a cadaver study.

While attrition from sharp bony surfaces is the most common cause of extensor digiti minimi (EDM) tendon rupture, the etiology of other cases of spontaneous EDM tendon rupture is still unknown. Friction within the compartment may play a role, especially with ulna dislocation. The purpose of this study was to compare gliding resistance of the EDM tendon with that of a tendon which rarely ruptures spontaneously, the extensor digitorum communis of the middle finger (EDC III) tendon, under various wrist and ulna head positions. Eight fresh frozen cadavers were used. Gliding resistance between the tendon and its sheath in each compartment was measured in five different wrist positions and three different ulna head positions. Gliding resistance of the EDM tendon (0.13 +/- 0.03 N) was significantly greater than the EDC III tendon (0.09 +/- 0.03 N) (p < 0.05). For the EDM tendon, the gliding resistance in ulnar deviation or pronation was higher than the gliding resistance in neutral, radial deviation, or supination (p < 0.05), and the gliding resistance with ulnar lengthening (over 6 mm) or dorsal ulnar dislocation (over 9 mm) was higher than in neutral ulnar head positioning. For the EDC III tendon, the gliding resistance in ulnar deviation was significantly higher than the gliding resistance in neutral, radial deviation, or supination, or dorsal dislocation with ulnar lengthening (p < 0.05). Wrist ulnar deviation, ulnar dorsal dislocation (over 9 mm), and ulnar lengthening (over 6 mm) increased the gliding resistance of the EDM tendon. In patients at risk for EDM rupture, such as those with rheumatoid arthritis or distal radioulnar joint osteoarthritis, avoiding such positions may be advantageous.

Aged↗
PubMed1999

[Blood supply of the quadriceps tendon].

Degenerative changes have been considered to be a cause for spontaneous quadriceps tendon rupture. Aim of this study is to investigate the microvasculature of the quadriceps tendon by injection techniques and immunohistochemical methods (antibodies against laminin) with regard to the pathogenesis of tendon degeneration. The blood supply of the quadriceps tendon arises from descending branches of the lateral circumflex femoral artery, by branches of the descending geniculate artery and by branches of the medial and lateral superior geniculate arteries. Blood vessels penetrate the tendon from the surrounding connective tissue and anastomose with a longitudinally orientated intraligamentous network. Compared to the surrounding synovial layer, the amount of vessels in the tendon substance is greatly reduced. The distribution of blood vessels within the quadriceps tendon is not homogenous. The anterior or superficial part of the tendon has a complete vascular network that extends from the musculo-tendinous junction to the patella. Within the deep portion of the quadriceps tendon there is an oval shaped avascular area which measures app. 30 mm in length and app. 15 mm in width. Within this area the immunohistochemical proof of laminin is negative. An explanation for the absence of blood vessels may be compressive stress caused by the patellar groove which serves as hypomochlion for the quadriceps tendon when the knee is flexed. The occurrence of an avascular zone within the deep layer of the tendon that is directed to the joint cavity may explain the frequency of degenerative changes in this region.

Adult↗
PubMed2004

Combined rupture of the tibialis anterior and the extensor hallucis longus tendons--functional reconstruction.

BACKGROUND: Traumatic rupture of the tibialis anterior (TA) tendon represents a very rare foot injury. A combined injury of both the TA and the extensor hallucis longus (EHL) tendons has not yet been reported. Within the scope of this work we will prove that tendon transfers in cases of combined tendon injuries are a reasonable course of action in order to achieve the aim of a functional reconstruction. METHODS: A combined rupture of the tibialis anterior (TA) and the extensor hallucis longus (EHL) tendons was treated by suturing the EHL tendon to the distal TA tendon stump. The TA insertion was secured and the distal portion of the EHL tendon attached to an extensor digitorum slip. The TA muscle was proximally attached to the tendinous EHL segment. RESULTS: A 1 year follow-up verified very good results, showing the patient without complaints in regard to the trauma. Compared with the contralateral non-affected side, the repaired foot showed very satisfactory results in reference to range of motion, strength and gait. CONCLUSION: With this work we proved that tendon transfers in cases of combined tendon injuries make sense in order to achieve functional reconstruction. This approach preserves function and strength and avoids the problems and risks of alternate treatment techniques, including tendon grafting.

Adult↗
PubMed1999

Blood supply of the tibialis anterior tendon.

Injection techniques and immunohistochemical methods (antibodies against laminin) were performed to uncover the vascular pattern of the human tibialis anterior tendon with regard to spontaneous rupture of this tendon. Proximally, the blood supply of the tibialis anterior tendon mainly arises from the anterior tibial artery. Distally, the tendon is supplied by branches of the medial tarsal artery. Blood vessels enter the peritenon via vinculae from the posterior side. From the peritenon, the blood vessels penetrate the tendon and anastomose with a longitudinally orientated intratendinous network. Compared with the surrounding peritenon, the number of vessels in the tendon substance is greatly reduced. The distribution of blood vessels within the anterior tibial tendon is not homogenous. The posterior part of the tendon has a complete vascular network that extends from the musculotendinous junction to the insertion at the bone. In the anterior half of the tendon, there is an avascular zone between 45 and 67 mm in length. The location of the avascular zone correlates well with the location of the most frequent site of spontaneous rupture of the tibialis anterior tendon reported in the literature. Hypovascularity has to be considered as an etiological cofactor for spontaneous rupture of the tibialis anterior tendon.

Aged↗
PubMed2004

Abnormal tenocyte morphology is more prevalent than collagen disruption in asymptomatic athletes' patellar tendons.

This study investigated the prevalence of each of the four features of patellar tendinosis in asymptomatic athletic subjects undergoing patellar tendon anterior cruciate ligament (ACL) reconstruction. Fifty subjects (39 males and 11 females) undergoing ACL reconstruction using a patellar tendon graft were screened for previous tendon symptoms, training and playing history and had their patellar tendons examined with ultrasound prior to surgery. During surgery, a small piece of proximal posterocentral tendon was harvested, fixed and examined under light microscopy. Histopathological changes were graded for severity. Results demonstrate that 18 tendons were abnormal on light microscopy and 32 were normal. There were no differences between subjects with and without pathology in respect of training, recovery after surgery and basic anthropometric measures. Three tendons were abnormal on ultrasound but only one had proximal and central changes. Tendons showed a consistent series of changes. Tenocyte changes were found in all but one of the abnormal tendons. In all but one of the tendons with increased ground substance there were tenocyte changes, and collagen separation was always associated with both tenocyte changes and increased ground substance. No tendons demonstrated neovascularization. It appears that cellular changes must be present if there is an increase in ground substance, or collagen and vascular changes. Further research is required to confirm these findings.

Adult↗
PubMed2001

Gliding resistance after repair of partially lacerated human flexor digitorum profundus tendon in vitro.

OBJECTIVE: This study reports the gliding resistance between repaired, partially lacerated tendon and pulley in human cadaver digits, using several commonly employed repair techniques. BACKGROUND: Suture techniques with multi-strands and locking loops have been recommended to reduce the risk of rupture of the repair tendon with early active motion. Such sutures may increase the gliding resistance, and the gliding resistance after tendon repair is also an important factor influencing the rehabilitation. METHOD: 105 specimens of second, third, or fourth fingers from 36 adult human hands were tested for the gliding resistance between flexor digitorum profundus tendon and A2 pulley in the normal condition. After an 80% laceration, each tendon was repaired with one of the following suture techniques: (1) Kessler; (2) modified Kessler; (3) Savage; (4) Lee; (5) Tsuge; and (6) Becker. All suture techniques were reinforced with a circumferential epitenon simple running suture. After tendon repair, the gliding resistance was remeasured. RESULTS: The gliding resistance of the Becker repair was significantly greater than each of the other four repairs (P<0.05). The resistance of the modified Kessler repair was significantly less than that of the Kessler, Savage, or Tsuge repairs. CONCLUSIONS: We conclude that the type of tendon repair can significantly affect the gliding resistance between the tendon and pulley system after tendon repair. RELEVANCE: The design of the tendon repair, through its effect on friction, may have an adverse effect on the clinical results of tendon mobilization.

Aged↗
PubMed1999

Frequency analysis of echo texture in tendon.

A texture discriminant based on spatial frequencies is proposed for characterizing B-scans of Achilles' tendon. The anisotropic echo texture of normal tendon has an ellipsoidal spatial spectrum that can be quantified by the ratio of the major-to-minor axis and by the direction of the major axis. Applying a moving window to the B-scan, a corresponding tissue elliptical axis ratio (TEAR) image is derived that segments out tendon. The algorithm was applied to B-scan images taken from 13 volunteers, 6 of whom had tendon abnormalities: tendon rupture (n = 3) or cholesterol deposits (xanthomas) in patients with heterozygous familial hypercholesterolemia (n = 3). The average TEAR value was 1.75 +/- 0.17 for normal tendon, 1.04 +/- 0.06 for torn tendon, and 1.31 +/- 0.16 for tendons with xanthomas. The dispersion of the directionality vectors was used to further differentiate tendons with xanthomas from normal tendons. This technique appears to be useful for characterizing both diffuse and focal tendon abnormalities.

Achilles Tendon↗
PubMed2003

Two-portal repair of canine flexor tendon insertion site injuries: histologic and immunohistochemical characterization of healing during the early postoperative period.

PURPOSE: In vivo animal studies have indicated that the complex structure of the tendon-bone interface may not be restored after repair even under optimal conditions. Controversy exists about the histologic findings in the early postoperative period after tendon reattachment to bone; this may have impact on biomechanical properties. The objective was to study the histologic structure and immunohistochemical staining of the tendon-bone interface in a large model of digital flexor tendon-bone repair. The hypothesis was that the tendon-bone interface matures and assumes a progressively more anatomic histologic and immunohistochemical appearance during the first 6 weeks after repair. METHODS: Twenty-four canine flexor digitorum profundus tendons were released from their insertion by sharp dissection and repaired to bone. The forelimb was immobilized after surgery and 10 minutes of daily passive motion rehabilitation was performed. Dogs were killed at 10, 21, and 42 days after surgery. Hematoxylin-eosin and immunohistochemical staining for types I, II, and II collagen were performed. RESULTS: Although at both 10 and 21 days after surgery substantial inflammation was seen at the tendon-bone repair site, this had decreased markedly by 42 days. Although direct apposition of tendon to bone was seen at 42 days, the mature tendon-bone insertion site was not recreated by this time. Staining for types I and III collagen was diffuse throughout the tendon-bone insertion throughout the interval examined. CONCLUSION: These findings suggest that at 6 weeks after surgery the intact tendon-bone repair site shows minimal histologic and molecular similarity when compared with unoperated specimens.

Animals↗
PubMed1998

Biochemistry and biomechanics of healing tendon: Part II. Effects of combined laser therapy and electrical stimulation.

PURPOSE: In previous studies we demonstrated that early mechanical loading and laser photo-stimulation independently promoted tendon healing. Thus, we tested the hypothesis that a combination of laser phototherapy and mechanical load would further accelerate healing of experimentally tenotomized and repaired rabbit Achilles tendons. METHODS: Following surgical tenotomy and repair, the tendons of experimental and control rabbits were immobilized in polyurethane casts for 5 d. The repaired tendons of experimental rabbits received mechanical load via electrical stimulation-induced contraction of the triceps surae for 5 d. In addition, experimental tendons were treated with daily doses of 1 J.cm-2 low intensity helium-neon laser throughout the 14-d experimental period. RESULTS: The combination of laser photostimulation and mechanical load increased the maximal stress, maximal strain, and Young's modulus of elasticity of the tendons 30, 13, and 33%, respectively. However, MANOVA revealed no statistically significant differences in these biomechanical indices of repair of control and experimental tendons. Biochemical assays showed a 32% increase in collagen levels (P < 0.05) and an 11% decrease in mature cross-links in experimental tendons compared with that in controls (P > 0.05). Electron microscopy and computer morphometry revealed no significant differences in the morphometry of the collagen fibers and no visible differences in the ultrastructure of cellular and matrical components of control and experimental tendons. CONCLUSIONS: These findings indicate that the combination of laser photostimulation and early mechanical loading of tendons increased collagen production, with marginal biomechanical effects on repaired tendons.

Achilles Tendon↗
PubMed1996

Effects of laser versus scalpel tenolysis in the rabbit flexor tendon.

The use of surgical lasers has been shown to decrease adhesion formation as compared with scalpel control groups in various surgical procedures. The potential benefits of laser technology have not been assessed in the treatment of adherent tendons. The current study was designed to first develop a reliable and reproducible model for consistent adhesion formation following flexor tendon trauma. The second goal was to compare the effects of laser tenolysis procedures on tendon gliding with those of traditional scalpel tenolysis. In phase I, the adhesion-induction model utilized bilateral standardized crush- abrasion injuries to the hind limb digital flexor tendons of New Zealand White rabbits. Following 4 weeks of immobilization, the animals were sacrificed, and peritendoneal adhesions were assessed biomechanically. A significantly higher maximal force was required to extract the adherent tendons from the foot as compared with nontraumatized control tendons. In phase II, six groups of animals underwent the same standardized tendon trauma. Four weeks later the rabbits were randomly assigned to undergo either CO2 laser or holmium:YAG laser tenolysis on one foot. Scalpel lysis was used on the contralateral foot and served as an intraindividual control. Biomechanical assessment was performed at 1, 2, and 4 weeks following tenolysis. Significantly less force was required to extract the treated tendons at 1 and 2 weeks following holmium:YAG laser tenolysis when compared with scalpel or CO2 laser tenolysis. After 4 weeks, differences between holmium:YAG and CO2 laser and scalpel treatment were no longer significant. Extracted tendons were pulled apart to failure, and no difference in breaking strength was noted between groups. We conclude that holmium:YAG laser tenolysis results in easier tendon gliding as compared with scalpel or CO2 laser tenolysis at early time points. Laser tenolysis does not affect intrinsic tendon strength.

Anesthesia, General↗
PubMed1998

Macroscopic 'degeneration' of equine superficial digital flexor tendon is accompanied by a change in extracellular matrix composition.

Injuries to the superficial digital flexor tendon are common in horses required to gallop and jump at speed. Partial rupture of this tendon usually occurs in the central core of the midmetacarpal region and may be preceded by localised degenerative changes. Post mortem examination of apparently normal equine flexor tendons has revealed an abnormal macroscopic appearance in the central core, characterised by a reddish discolouration. We have previously shown that there is also physical damage to the collagen fibres. In the present study we tested the hypothesis that the abnormal appearance is accompanied by changes in the composition of the extracellular matrix of the tendon. Biochemical analysis of the extracellular matrix demonstrated an increase in total sulphated glycosaminoglycan content, increase in the proportion of type III collagen and decrease in collagen linked fluorescence in the central core of 'degenerated' tendons relative to tissue from the peripheral region of the same tendon. Dry matter content and total collagen content were not significantly different between tendon zones or normal and 'degenerated' tendons. These changes suggest a change in cell metabolism and matrix turnover in the central core of the tendon and are likely to contribute to a decrease in mechanical properties in this part of the tendon, predisposing to the characteristic partial rupture of the tendon.

Animals↗