SEARCH · PubMed Health

Results for “Fibrocartilage”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 19 recordsLinked to original sources

PubMed1999

Communicating defects of the triangular fibrocartilage complex without disruption of the triangular fibrocartilage: a report of two cases.

Perforations or communicating defects of the triangular fibrocartilage complex have been more commonly identified after Palmer published his classification system (J Hand Surg 1989;14A:594-606). To his variants of class 1B (traumatic) ulnar avulsion with or without distal ulnar fracture, a third category may be added: defects of the ulnar collateral ligament without any associated disruption of the triangular fibrocartilage. The ulnar collateral ligament can be defined as an ulnar capsular structure between the more discrete elements of the triangular fibrocartilage and the ulnar ligaments, with the defect or perforation being distal to the intact triangular fibrocartilage and exiting into the floor of the extensor carpi ulnaris sheath. We present 2 cases that illustrate the diagnosis, the use of both magnetic resonance imaging and arthrography to confirm the diagnosis, the associated dorsal ulnar cutaneous nerve pain distribution, and the open direct and retinacular flap repair.

Adult↗

PubMed2004

A comparison of combined arthroscopic triangular fibrocartilage complex debridement and arthroscopic wafer distal ulna resection versus arthroscopic triangular fibrocartilage complex debridement and ulnar shortening osteotomy for ulnocarpal abutment syndrome.

PURPOSE: Treatment of ulnocarpal abutment (UAS) syndrome involves decompression of the pressure and impingement, or abutment of the ulnocarpal articulation. Debridement of triangular fibrocartilage complex (TFCC) tears alone in the patient with UAS may have a failure rate of as much as 25% to 30%. Ulnar shortening osteotomy (USO) can be an effective treatment of failed TFCC debridement. Good results have been reported with combined arthroscopic TFCC debridement and mechanical arthroscopic distal ulnar resection. Similar results have been reported with both ulnar shortening osteotomy and open wafer distal ulnar resections in the UAS patient. Because all of these treatment choices appear to yield similar relief of symptoms, determination of the optimal treatment protocol remains a point of debate. The purpose of this study was to evaluate 2 different surgical treatments for UAS. TYPE OF STUDY: Retrospective review. METHODS: Eleven combined arthroscopic TFCC debridement and arthroscopic distal ulna resections (arthroscopic wafer procedures; AWP) were compared with 16 arthroscopic TFCC debridement and USOs. All patients had diagnostic wrist arthroscopy and arthroscopic TFCC debridement. All patients presented with ulnar wrist pain or neutral or positive ulnar variance, and all experienced at least 3 months of failed conservative management. RESULTS: At mean follow-up times of 21 and 15 months, respectively, 9 of 11 patients showed good to excellent results after arthroscopic TFCC debridement and AWP compared with 11 of 16 after arthroscopic TFCC debridement and USO. A statistically significant difference (P <.05) in the complication rates was identified, including secondary procedures and tendonitis. One secondary procedure and 2 cases of tendonitis were seen in the arthroscopic wafer group. CONCLUSIONS: Combined arthroscopic TFCC debridement and arthroscopic wafer procedure provides similar pain relief and restoration of function with fewer secondary procedures and tendonitis when compared with arthroscopic TFCC debridement and USO, for the treatment of UAS. LEVEL OF EVIDENCE: Level III.

Adult↗

PubMed2000

Chronic triangular fibrocartilage complex tears with distal radioulna joint instability: A new method of triangular fibrocartilage complex reconstruction.

From September 1996 to September 1997, 27 adult patients were diagnosed with chronic triangular fibrocartilage complex (TFCC) tears with distal radioulna joint (DRUJ) instability in our clinic. They all received the procedure of TFCC reconstruction with partial extensor carpi ulnaris (ECU) tendon combined with or without ulnar shortening. There were 26 males and one female in the study with a mean age of 22.4 years. The follow-up period ranged from 22 to 28 months with a mean of 26.2 months. 24 patients who had positive or zero ulnar variance received the procedure of ulnar shortening. Three patients who had minus ulnar variance only received TFCC reconstruction. After the operation, the DRUJ was fixed by a 2.0 mm K-wire for 4 weeks. All patients underwent a rehabilitation program and they were reexamined at our outpatient department (OPD). The results were graded according to the Mayo Modified Wrist Score. Five of the 27 patients rated their wrists 'excellent', 18 rated 'good', and 4 rated 'fair. Overall, a total of 23 patients (85%) rated satisfactorily and returned to work or sport activities. In the 4 patients rated 'fair', mild pain at work and/or exercise, and mildly limited supination were found; however their grip strength was improved at least by 65% compared to the opposite hand. Therefore, as suggested by this study, TFCC reconstruction with partial ECU tendon combined with the ulnar shortening procedure is an alternative method for chronic TFCC tears with DRUJ instability.

Journal Article↗

PubMed1998

Triangular fibrocartilage of wrist: presentation on high resolution ultrasonography.

This study consisted of two parts. Part I is for detection of the normal triangular fibrocartilage by high resolution ultrasonography and Part II is a preliminary study to evaluate high resolution ultrasonography in the diagnosis of tears of the triangular fibrocartilage. Normally, the triangular fibrocartilage was seen in all cases in Part I as an inverse triangular structure of homogeneous hyperechogenicity on transverse and oblique sagittal scans at the level of the distal radioulnar joint. At its waist it measured from 2.3 to 4.2 mm (mean, 3.0 +/- 0.5 mm) on oblique sagittal scan and from 2.5 to 3.7 mm (mean, 3.2 +/- 0.4 mm) on transverse scan. Under normal conditions, the triangular fibrocartilage is thicker than 2.5 mm on both transverse and oblique sagittal sections with a confidence level of 95%. In Part II, eight of the 47 wrists were found to be hypoechoic in the triangular fibrocartilage region, which proved to be tears by arthrography. Six cases showed a homogeneous hyperchoic triangular fibrocartilage measuring from 1.8 to 2.8 mm (mean, 2.3 +/- 0.5 mm) in transverse section and from 0 to 2.2 mm (mean 1.2 +/- 1.1 mm) in oblique sagittal section; five of these proved to be tears by arthrography. In contrast, 33 wrists had a homogeneous hyperechoic triangular fibrocartilage measuring from 2.5 to 4 mm (mean, 3.1 +/- 0.4 mm) and 2.5 to 4.2 mm (mean, 3.1 +/- 0.6 mm) on transverse and oblique sagittal sections, respectively; 27 proved to be normal triangular fibrocartilage by arthrography. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 68.4%, 96.4%, 92.9%, 81.8%, and 85.1%, respectively. HRUS can display the normal triangular fibrocartilage as a homogeneous hyperechoic and inverted triangular structure. The torn triangular fibrocartilage appears as a hypoechoic region or as thinning (< 2.5 mm) of the hyperechoic structure on either transverse or oblique sagittal section. HRUS has an acceptable accuracy in the diagnosis of triangular fibrocartilage tear.

Adolescent↗

PubMed1996

Ultrastructure of fibrocartilages at the insertion of the rat Achilles tendon.

The ultrastructure of 3 fibrocartilages is described at the insertion of the adult rat Achilles tendon. Enthesial fibrocartilage lies at the tendon-bone junction, sesamoid fibrocartilage in the deep surface of the tendon where it presses on the calcaneus, and periosteal fibrocartilage covers the opposing surface of the bone. All had some features that could be interpreted as typical of fibrous tissues and other features that were more characteristic of cartilage. The general extracellular matrix was largely fibrous and had relatively little visible proteoglycan. In contrast, the cells had features more common in cartilage--dilated rough endoplasmic reticulum, glycogen and lipid, and pericellular matrix rich in proteoglycans and fine collagen fibrils. The periosteal fibrocartilage was the most 'cartilaginous' in character, probably because it develops rapidly after birth as a secondary cartilage from the calcaneal periosteum whereas enthesial and sesamoid fibrocartilages develop by metaplasia of tendon fibroblasts. A major difference between the 3 fibrocartilages was the arrangement of their collagen fibrils. There were parallel bundles in enthesial fibrocartilage but interweaving networks in the sesamoid and periosteal fibrocartilages. This probably reflects different functional demands of the tissues. The sesamoid and periosteal fibrocartilages directly formed the boundaries of the retrocalcaneal bursa and were not covered by synovium. Both were lined by an electron dense, articular surface lamina that prevented cell contact with the bursa. It significance is unclear, but it could protect against wear and tear, represent material being shed into the bursal cavity or control nutrient exchange with the synovial fluid.

Achilles Tendon↗

PubMed2000

Ultrastructure of the developing fibrocartilage of the os penis of rat.

Development of the fibrocartilage of the os penis of rat was studied by transmission electron microscopy. Prepubertal (0-4 weeks of development) and pubertal (4-8 weeks of development) males were examined. Effects of castration on the development of the fibrocartilage were also examined. During the first 0-4 weeks of development, cells in the primordium of the fibrocartilage became large and the cytoplasm had well-developed rough endoplasmic reticulum (rER) and many intermediate filaments. Collagen fibers increased markedly in amount in the extracellular matrix (ECM) during the period. For 4-6 weeks, when gonadal secretion of androgens increases, the cells developed into mature chondrocytes with lacunae. Collagenous bundles were pushed away from the lacunae, resulting in a characteristic appearance of this fibrocartilage. The cytoplasm of the mature chondrocytes of the fibrocartilage was characterized by many intermediate filaments, oil droplets, glycogen granules, and well-developed rER. At 6 weeks, calcification started on the cell membrane of the mature chondrocytes. At 8 weeks, a large part of the cartilage matrix was calcified. Matrix vesicles that originate from degenerated chondrocytes were found in the ECM of decalcified samples. In castrated males, cells of the primordium of the fibrocartilage ceased further development after castration. Intermediate filaments were still abundant in the cytoplasm and collagen fibers increased even after castration, but mature chondrocytes never differentiated. There were no signs of matrix vesicle formation, calcification, or cell degeneration in the fibrocartilage primordium. The developmental process of the fibrocartilage can be subdivided into two phases: collagenous matrix formation during the prepubertal period (0-4 weeks), and maturation of chondrocytes and calcification after puberty (4-8 weeks).

Animals↗

PubMed1998

Fibrocartilage in tendons and ligaments--an adaptation to compressive load.

Where tendons and ligaments are subject to compression, they are frequently fibrocartilaginous. This occurs at 2 principal sites: where tendons (and sometimes ligaments) wrap around bony or fibrous pulleys, and in the region where they attach to bone, i.e. at their entheses. Wrap-around tendons are most characteristic of the limbs and are commonly wider at their point of bony contact so that the pressure is reduced. The most fibrocartilaginous tendons are heavily loaded and permanently bent around their pulleys. There is often pronounced interweaving of collagen fibres that prevents the tendons from splaying apart under compression. The fibrocartilage can be located within fascicles, or in endo- or epitenon (where it may protect blood vessels from compression or allow fascicles to slide). Fibrocartilage cells are commonly packed with intermediate filaments which could be involved in transducing mechanical load. The ECM often contains aggrecan which allows the tendon to imbibe water and withstand compression. Type II collagen may also be present, particularly in tendons that are heavily loaded. Fibrocartilage is a dynamic tissue that disappears when the tendons are rerouted surgically and can be maintained in vitro when discs of tendon are compressed. Finite element analyses provide a good correlation between its distribution and levels of compressive stress, but at some locations fibrocartilage is a sign of pathology. Enthesis fibrocartilage is most typical of tendons or ligaments that attach to the epiphyses of long bones where it may also be accompanied by sesamoid and periosteal fibrocartilages. It is characteristic of sites where the angle of attachment changes throughout the range of joint movement and it reduces wear and tear by dissipating stress concentration at the bony interface. There is a good correlation between the distribution of fibrocartilage within an enthesis and the levels of compressive stress. The complex interlocking between calcified fibrocartilage and bone contributes to the mechanical strength of the enthesis and cartilage-like molecules (e.g. aggrecan and type II collagen) in the ECM contribute to its ability to withstand compression. Pathological changes are common and are known as enthesopathies.

Adaptation, Physiological↗

PubMed2002

Limitations of MR imaging in the diagnosis of peripheral tears of the triangular fibrocartilage of the wrist.

OBJECTIVE: The treatment of peripheral tears of the triangular fibrocartilage complex is radically different from the more typical central, degenerative tears. To our knowledge, no reports in the imaging literature specifically evaluate tears of the ulnar attachment of the triangular fibrocartilage complex. We evaluated the accuracy of MR imaging in these patients. MATERIALS AND METHODS: Eighty-six MR imaging examinations of the wrist (41 indirect MR arthrograms and 45 unenhanced MR images) were evaluated: 20 wrists with surgically confirmed peripheral triangular fibrocartilage complex tears and 66 wrists with surgically documented normal ulnar attachment. These cases were evaluated by three experienced musculoskeletal radiologists, who were unaware of the surgical findings, to assess the presence of peripheral triangular fibrocartilage complex tears or fluid signal at the ulnar attachment of the triangular fibrocartilage complex. RESULTS: The sensitivity for evaluation of the peripheral triangular fibrocartilage complex tear was 17%, with a specificity of 79% and an accuracy of 64%. High signal intensity at the ulnar insertion of the triangular fibrocartilage complex as a marker for tear showed a sensitivity of 42%, a specificity of 63%, and an accuracy of 55%. Weighted kappa values revealed only fair agreement among the three observers. CONCLUSION: MR imaging does not adequately reveal the peripheral attachment of the triangular fibrocartilage complex.

Adolescent↗

PubMed1998

Fibrocartilages in the extensor tendons of the interphalangeal joints of human toes.

The extensor tendons of the fingers and toes form part of the capsule of the interphalangeal joint and press against the proximal phalanx during flexion. Previous work on the fingers has shown that there is a "sesamoid" fibrocartilage on the deep surface of each tendon that labels immunohistochemically for a variety of glycosaminoglycans and collagens. However, we know little about the molecular composition of the tendon in the toes. This question is of special interest, because the mechanics of the interphalangeal joints differ in the upper and lower limbs-the toes balance the forefoot, distribute load during the gait cycle, and transmit the pull of larger muscles. This means that their extensor tendons are more often under higher tension than those in the fingers. Here, we report the presence of an equivalent fibrocartilage and compare its immunolabelling characteristics in all the toes. Six forefeet were removed from elderly cadavers, and the interphalangeal (IP) joints were fixed in 90% methanol. The extensor tendon and its enthesis were dissected out from the IP joint of the big toe and from the proximal interphalangeal (PIP) joint of all lesser toes, decalcified, cryosectioned, and immunolabelled with a panel of monoclonal and polyclonal antibodies for type I, II, III, and VI collagens; chondroitin 4 and 6 sulphates; and dermatan and keratan sulphate. Antibody binding was detected with the Vectastain ABC Elite avidin-biotin-peroxidase kit (Vector Laboratories, Burlingame, CA). The extensor tendon in all the toes had a metachromatic, sesamoid fibrocartilage on its deep surface that immunolabelled for all glycosaminoglycans and for type I, III, and VI collagens. Labelling for type II collagen was seen in the sesamoid fibrocartilage of all toes but was particularly characteristic of the 2nd through 5th toes. The immunolabelling patterns of the enthesis fibrocartilage were similar in all toes and to results reported previously for fingers. The normal occurrence of type II collagen in the sesamoid fibrocartilage of the 2nd through 5th toes is in contrast to our published data on the fingers. The finding can be related to the more constant loading of the tendon in the toes. The greater prominence of type II collagen in the sesamoid fibrocartilage of the 2nd through 5th toes could be related to a difference in joint position during walking between the 1st toe and the 2nd through 5th toes--the PIP joints of the latter are usually more flexed than the IP joint of the former.

Adult↗

PubMed1999

Fibrocartilage in the extensor tendons of the human metacarpophalangeal joints.

The extensor tendons of the fingers cross both the metacarpophalangeal (MCP) and interphalangeal joints. Previous studies have shown that where the extensor tendons replace the capsule of the proximal interphalangeal (PIP) joint, they contain a sesamoid fibrocartilage that articulates with the proximal phalanx during flexion. The fibrocartilage labels immunohistochemically for a variety of glycosaminoglycans and collagens. In the current study, we investigate the molecular composition of the extensor tendons at the level of the MCP joints. This is of particular interest because the tendon has a greater moment arm at this location (and might thus be subject to greater compression), but is separated from the joint cavity by the capsule and peritendinous tissue. Six hands were removed from elderly cadavers (39-85 years of age) and the MCP joints were fixed in 90% methanol. The extensor tendons were dissected from all fingers, cryosectioned, and immunolabelled with a panel of monoclonal and polyclonal antibodies for types I, II, III, and VI collagens, chondroitin 4 and 6 sulphates, dermatan, and keratan sulphate and aggrecan. Antibody binding was detected with the Vectastain ABC 'Elite' avidin/biotin/peroxidase kit. The extensor tendons in all the fingers had a metachromatic sesamoid fibrocartilage on their deep surface which immunolabelled for types I, III, and VI collagens, and for all glycosaminoglycans and aggrecan. Labelling for type II collagen was also seen in some fibrocartilages and was a constant feature of all index fingers. This probably relates to the greater use of that digit and the higher loads to which its tendons are subject. Chondroitin 6 sulphate and type II collagen are the most consistent markers of the fibrocartilage phenotype and most of the chondroitin 6 sulphate is probably associated with aggrecan. It is concluded that the labelling profile of the tendon fibrocartilage in the different fingers at the MCP joints is broadly similar to that at the PIP joints. Thus, the potentially greater level of compression on the extensor tendons may be counterbalanced by the lack of fusion of the tendon with the joint capsule. It is suggested that the maintenance of a similar level of fibrocartilage differentiation at two different points along the length of the extensor tendon ensures that the tensile strength is the same in the two regions and that no weak link is present.

Adult↗

PubMed2003

The development of fibrocartilage in the elastic tendon of the chicken wing.

The elastic tendon of the chicken wing has five morphologically distinct regions. One of these regions is a distally located fibrocartilage from which fibrous connections extend to the capsule of the distal radius. In adult birds, this region shows the characteristics of a tendon-compressed fibrocartilage, with an accumulation of proteoglycans between thick collagen bundles arranged in a basket-weave formation. Here we study the development of this fibrocartilage in order to of compare it with other tendon fibrocartilages and try to identify the factors involved in fibrocartilage differentiation. This fibrocartilage initially developed by cell enlargement and accumulation of vimentin, with simultaneous deposition of proteoglycans in the extracellular matrix and an increase in the amount and thickness of collagen bundles. Elastic fibers were minor components associated with the collagen bundles. Cells could be classified into two main types. One was typically fibrocartilaginous and the other was fibroblast-like, the latter occurring in close association with the collagen bundles. These results establish the steps in the development of the elastic tendon fibrocartilage and provide a basis for future studies.

Animals↗

PubMed2001

Evidence of a hypermineralised calcified fibrocartilage on the human femoral neck and lesser trochanter.

Femoral neck fractures are a major cause of morbidity and mortality in elderly humans. In addition to the age-related loss of cancellous bone, changes to the microstructure and morphology of the metaphyseal cortex may be a contributing factor in osteoporotic hip fractures. Recent investigations have identified a hypermineralised tissue on the neck of the femur and trochanteric region that increases in fractional area with advancing age in both males (Boyce & Bloebaum, 1993) and females (Vajda & Bloebaum, 1999). The aim of this study was to determine if the hypermineralised tissue previously observed on the proximal femur is calcified fibrocartilage. Regional variations in the fractional area of hypermineralised tissue, cortical bone, and porosity of the cortical bone along the neck of the femur and lesser trochanter were also quantified. Comparison of back scattered electron and light microscope images of the same area show that regions of hypermineralised tissue correlate with the regions of calcified fibrocartilage from tendon and capsular insertions. The hypermineralised tissue and calcified fibrocartilage had similar morphological features such as the interdigitations of the calcified fibrocartilage into the bone, lacunar spaces, and distinctly shaped pores adjacent to the 2 tissues. Regions of the neck that did not contain insertions were covered with periosteum. There were no regional differences (P > 0.05) on the superior and inferior femoral neck in terms of the percentage area of hypermineralised calcified fibrocartilage, cortical bone, or cortical bone porosity. The lesser trochanter exhibited regional differences in the fractional area of hypermineralised calcified fibrocartilage (P = 0.007) and cortical bone (P = 0.007) but not porosity of the cortical bone (P > 0.05). The effects of calcified fibrocartilage on femoral neck periosteal expansion, repair, and mechanics are unknown, but may play a role in osteoporotic fractures and intracapsular fracture healing.

Cartilage↗

PubMed1990

Fibrocartilage in the attachment zones of the quadriceps tendon and patellar ligament of man.

Differences are reported in the quantities and distribution of uncalcified fibrocartilage at the attachment sites of the quadriceps tendon and the patellar ligament. The largest quantity of fibrocartilage was characteristic of the quadriceps tendon. A prominent wedge of fibrocartilage was seen in the proximal part of the tibial attachment of the patellar ligament, though there was no fibrocartilage in the most superficial fibres. Little fibrocartilage was seen at the patellar attachment of the patellar ligament. According to other workers, there is a similar change in angle (about 35 degrees) between the quadriceps insertion (in relation to the patella) and the tibial attachment of the patellar ligament (in relation to the tibia). However, there is virtually no change in angle at the origin of the patellar ligament (relative to the patella). Thus, fibrocartilage is least conspicuous where there is little motility near an attachment site. It is suggested that the larger amount of fibrocartilage in the quadriceps tendon compared with the tibial attachment of the patellar ligament may be related to the greater absolute size (and particularly anterior-posterior thickness) of the tendon compared with the ligament.

Aged↗

PubMed1995

Fibrocartilage associated with human tendons and their pulleys.

The presence of fibrocartilage in tendons that wrap around bony or fibrous pulleys is well known. It is an adaptation to resisting compression or shear, but the extent to which the structure of most human tendons is modified where they contact pulleys is less clear, for there has been no single comprehensive survey of a large number of sites. Less is known of the structure of the corresponding pulleys. In the present study, 38 regions of tendons that wrap around bony pulleys or pass beneath fibrous retinacula have been studied in routine histology sections taken from each of 2 or 3 elderly dissecting room cadavers. Most of the corresponding pulleys have also been examined. Fibrocartilage was present in 22 of the 38 tendon sites and it was most conspicuous where the tendons pressed predominantly against bone rather than retinacula and where they showed a large change in direction. Fibrocartilage was more characteristic of tendons at the ankle than the wrist, probably because the long axis of the foot is at right angles to that of the leg. There was considerable variation in the structure of tendon fibrocartilage. The most fibrocartilaginous tendons had oval or round cells embedded in a highly metachromatic matrix with interwoven or spiralling collagen fibres. At other sites, fibrocartilage cells were arranged in rows between parallel collagen fibres. The differences probably relate to differences in development. A single tendon could be modified at successive points along its length and fibrocartilage could be present in the endotenon and epitenon as well as in the tendon itself. Pathological changes seen in 'wrap around' tendons were fragmentation and partial delamination of the compressed surface, chondrocyte clustering, fatty infiltration and bone formation. Three types of pulleys were described for tendons--bony prominences and grooves, fibrous retinacula and synovial joints. The extent of cartilaginous differentiation on the periosteum of bony pulleys frequently mirrored that in the corresponding tendon. The cartilage or fibrocartilage prevents the tendon from 'sawing' through the bone. Some of the best known retinacula were largely fibrous, though the inferior peroneal retinaculum and the trochlea for the superior oblique were cartilaginous. The results underline the considerable regional heterogeneity in different tendons and their pulleys. They show that one tendon is not like another and that tendons may need to be carefully selected for particular surgical transfers or joint reconstructions.

Aged↗

PubMed2007

Peripheral tear of the triangular fibrocartilage: depiction with MR arthrography of the distal radioulnar joint.

OBJECTIVE: Although central tears of the triangular fibrocartilage are easily seen on imaging, peripheral tears of the ulnar attachment are frequently missed. The aim of this study was to evaluate the accuracy of MR arthrography of the distal radioulnar joint in depiction of peripheral tears of the triangular fibrocartilage. MATERIALS AND METHODS: Forty-one patients (18 women, 23 men; mean age, 38 years; age range, 18-60 years) underwent MR arthrography and wrist arthroscopy. For MR arthrography, iopamidol (300 mg I/mL) and gadopentetate dimeglumine (4 mmol/L) were injected into the distal radioulnar joint. Consensus review of both MR arthrograms and conventional arthrograms was performed by two experienced musculoskeletal radiologists. Presence or absence of communicating and noncommunicating tears of the ulnar attachment of the triangular fibrocartilage was recorded. Arthroscopy was used as the standard of reference for determining sensitivity, specificity, and accuracy in detection of tears of the ulnar attachment. RESULTS: At MR arthrography, communicating tear of the ulnar attachment was diagnosed in three patients, noncommunicating tear in 19 patients, and normal attachment in 19 patients. Arthroscopy revealed peripheral tear of the triangular fibrocartilage in all three patients with communicating tear, in 14 of 19 patients with noncommunicating tear, and in three of 19 patients with normal attachment. The sensitivity was 85% (17/20), specificity was 76% (16/21), and accuracy was 80% (33/41). CONCLUSION: MR arthrography of the distal radioulnar joint is accurate in depiction of peripheral tears of the ulnar attachment of the triangular fibrocartilage. These tears often appear as noncommunicating tears extending from the distal radioulnar joint into the triangular fibrocartilage.

Adolescent↗

PubMed2002

Experimental confirmation of the sheep model for studying the role of calcified fibrocartilage in hip fractures and tendon attachments.

Research has shown that there is a dramatic increase in the fractional area of calcified fibrocartilage from tendon and capsular insertions on the human femoral neck (Vajda and Bloebaum, 1999; Shea et al., 2001b). Additional information regarding the properties of the proximal femur's cortical shell, gained from the use of an animal model, may result in a better understanding of elderly hip fracture since the cortical shell is a significant contributor to the strength of the proximal femur. The objective of the present study was to determine if the greater trochanter's tendon insertions of the human, rat, and sheep differ in terms of morphology and mineralization. The tendons of the greater trochanter of the human, rat, and sheep were observed to insert via a fibrocartilage insertion. The mineral content of the human and sheep calcified fibrocartilage was significantly higher than that of the rat calcified fibrocartilage (P < 0.01). Additionally, the mineral content of the rat cortical bone was significantly higher than that of the human cortical bone (P < 0.01). The mineral content of the calcified fibrocartilage and bone of the human and sheep were not statistically different from each other. There were also more similarities between the bone structure and lacunae density of the human and sheep than between the human and the rat. This suggests that the tendon insertions of the sheep are a better model than the tendon insertions of the rat for the investigation of calcified fibrocartilage in elderly hip fractures.

Aged↗

PubMed2004

Remodeling capacity of calcified fibrocartilage of the hip.

It is well known that the incidence of hip fractures increases exponentially with age and that hip fractures can be a major cause of morbidity and morality among elderly humans; this has prompted substantial research on hip fractures. The majority of research on hip fractures has focused on morphological changes of the proximal femur with age. Recently calcified fibrocartilage in the proximal femur has been shown to increase in fractional area with age and can ultimately make up to 60% of the fractional area of the cortex. However, the capacity of the tissue to remodel and heal is currently unknown. The purpose of the present study was to determine the remodeling capacity of calcified fibrocartilage on the proximal femur compared to the underlying cortical bone. The remodeling capacity of calcified fibrocartilage and cortical bone was assessed in adult female sheep by means of tetracycline labeling. The number of double and single labels within each tissue type was quantified and analyzed with a paired t-test. The data showed very few labels in the calcified fibrocartilage compared to the cortical bone. This indicated that calcified fibrocartilage lacked a capacity to remodel in a manner similar to bone. The results of this investigation demonstrate that while the underlying cortical bone was actively remodeling, the calcified fibrocartilage appeared to have no remodeling capacity similar to that of cortical bone.

Animals↗

PubMed1999

In situ expression of collagen and proteoglycan genes during development of fibrocartilage in bovine deep flexor tendon.

A region of fibrocartilage develops in bovine deep flexor tendon where the tissue wraps around bone and is subjected to compressive and shear forces in addition to tension. There is no fibrocartilage at this location in fetal tendon or in adjacent adult tendon that is subjected to tensional load only. We investigated the development of fibrocartilage in tendon using in situ hybridization to localize cells that express collagen and proteoglycan genes typical of either tendon or cartilage. The signal for type I collagen and decorin was high in cells throughout fetal and newborn tendon, as is expected in a growing tissue composed predominantly of type I collagen. No signal for aggrecan was seen in either fetal or newborn tendon. No hybridization with any of the probes for collagen or proteoglycan was detected in cells in the tensional region of adult tendon, indicating that the cells in this tissue are normally quiescent. However, the cells in the fibrocartilage of adult tendon displayed a high level of expression for types I and II collagen, decorin, biglycan, and aggrecan. This suggests that the fibrocartilage in adult tendon is a dynamic tissue. Expression of type IIA collagen is considered a marker of prechondrocytes. Type IIA collagen gene expression was present throughout both the tensional and compressed regions of fetal and newborn tendon but was absent in cartilage and adult tendon. This suggests that cells located throughout fetal tendon may have the capacity to develop as chondrocytes. Fibrocartilage signal was detected for type I collagen in 75% of the cells and for type II collagen in 50% of the cells at one location in adult tendon, suggesting that some cells in this tissue could have expressed mRNA for both type I and type II collagen.

Animals↗