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 361 records · Page 20Linked to original sources
PubMed1991

[Simultaneous rupture of the patellar tendon and the contralateral quadriceps tendon in chronic kidney insufficiency].

Simultaneous ruptures of the patellar tendon and the contralateral quadriceps tendon, happening either spontaneously or with a preceding minor trauma, is a rare event especially in young patients. Major degenerative changes in the tendons' structure are most often a prerequisite for a trauma such as this. The reasons for these excessive pathological findings in tendon tissue structure can be chronic renal failure and resulting secondary hyperparathyroidism. The causal relationship will be discussed in front of a patients case history followed by a review of the relevant literature.

Adult↗
PubMed1985

A low-serum medium for tendon cells: effects of growth factors on tendon cell growth and collagen production.

Primary avian tendon cells maintain a higher percentage of net collagen synthesis when cultured in low serum concentrations than in high. However, under these conditions the cells grow slowly and can only be subcultured one or two times. We therefore examined various growth factors for their effects on tendon cell multiplication in order to develop a new medium for these cells. Of the growth factors tested, epidermal growth factor, insulin, transferrin, and selenium each stimulated tendon cell division. We also investigated how these factors affected collagen synthesis, and found that they all increased both collagen and noncollagen protein synthesis equally, thus leaving the percentage of protein synthesis devoted to collagen the same. When combined with 0.2% fetal bovine serum in Ham's F12 medium, epidermal growth factor and insulin together stimulated cell multiplication to a level comparable to that of cells grown in Ham's F12 plus 10% serum. Cells could also be successfully subcultured in this medium. Thus, by using selected growth factors we have reduced significantly the serum requirements of cultured tendon cells without affecting population doubling time or subculture capability. This low-serum medium should prove useful for the study of the regulation of collagen biosynthesis.

Animals↗
PubMed2006

[Simultaneous rupture of a patellar tendon and contralateral quadriceps tendon].

The simultaneous bilateral rupture of the quadriceps tendon is a rare injury; only occasional reports exist about the bilateral simultaneous rupture of the patellar tendon. Degenerative changes of the tendon due to drugs or diseases lead to the rupture. We describe two cases of simultaneous rupture of the patellar and contralateral quadriceps tendons; only one patient had special risks. We report the management of therapy and the functional results using the Lysholm score and Knee Rating Scale.

Adult↗
PubMed2000

[Patellar tendon rupture after anterior cruciate ligament reconstruction with autologous patellar tendon-bone transplant. A case report].

Patellar ligament ruptures due to a complication after usage of bone-tendon autograft for an anterior cruciate ligament reconstruction happens seldom. During surgeries to restore continuity a fascia-lata-strip may be wrapped in and fixated to secure the primary tendon suture. This may be done in addition to the usually employed patella-tibial wiring cerclage. Whether a matrix for the scarred healing tendon will be created in addition to the construction of a support for the primary tendon seam without a foreign body reaction has to be left to further histological clarifications that cannot be implemented in the present casuistry.

Adult↗
PubMed2004

A novel technique to measure active tendon forces: application to the subscapularis tendon.

This paper describes the design and use of a novel system for quantification of active tendon forces. An arthroscopically implantable force probe (AIFP) was inserted arthroscopically into the subscapularis tendon of the shoulder in vivo. The output response of this device was calibrated in situ with known forces applied to the tendon using an arthroscopic technique. On recovery of motor control following interscalene regional anaesthesia, the force within the tendon during active muscle contraction was measured. The AIFP was then retrieved through an arthroscopic portal. The technique showed that the subscapularis may produce forces of 250 N during maximum internal rotation of the shoulder.

Arthroscopy↗
PubMed1999

Healing of the patellar tendon donor defect created after central-third patellar tendon autograft harvest. A long-term histological evaluation in the lamb model.

Patellar tendon donor defect (PTDD) healing after patellar tendon autograft (PTA), was evaluated in 12 lambs (24 knees), by means of conventional histology, immunohistochemistry and image analysis. The results of this study indicate that the PTDD is replaced by a tissue that does not assume the histological characteristics of a normal patellar tendon. Both the Hoffa fat pad (HFP) and the paratenon play an important role in the healing process, although qualitative and quantitative chronological differences were found, which supports the concept of a "two-time process". The HFP initiates the repair process, and is the main active proliferative tissue compartment during the first week. Once the process is established, the paratenon and, in particular, its synovial lining, starts proliferative activity and virtually substitutes that of the HFP, which rapidly loses activity in a few days. Moreover, donor-site morbidity after PTA could be the result of histological changes in the patellar tendon and environs in only a few cases. We have found inflammatory and neural changes in the refilled PTDD that could explain the anterior knee pain after PTA. Likewise, we have observed loss of Golgi corpuscles in the refilled PTDD, which could lead to proprioceptive loss after ACL reconstruction with PTA. Finally, we have observed shrinkage of the PTDD scar that could contribute to the etiopathogenia of a patella infera.

Animals↗
PubMed1988

Active tendon implants in flexor tendon reconstruction.

Forty-five active flexor tendon implants were evaluated after placement in scarred tendon beds of digits II through V. The implant is constructed of silicone rubber with a Dacron core, terminating in a loop proximally and a metal plate distally. Modification of the implant during the period of study has improved its reliability and longevity. The improvement in total active motion (TAM) averaged 72 degrees during implant functioning (stage I) in a group of digits that before operation were classified as 78% Boyes grade 5 (salvage). Complication rate during stage I was 11% (5 out of 45). Of the 27 digits evaluated after implant replacement by tendon autograft (stage II), there was an overall improvement in 62 degrees total active motion with 70% of digits being Boyes grade 5. Many of the complications were believed to be avoidable with experience. This study demonstrates the feasibility of an active tendon implant and the possibility of a permanent prosthesis.

Adolescent↗
PubMed2006

Initial biomechanical properties of staple-anchor Achilles tendon allograft and interference screw bone-patellar tendon-bone autograft fixation for anterior cruciate ligament reconstruction in a cadaveric model.

PURPOSE: Anterior cruciate ligament (ACL) reconstruction is a common procedure that has a fairly high success rate. Despite such success, controversy exists with regard to fixation and graft type. The purpose of this study was to quantify the maximum load to failure for staple-anchor freeze-dried Achilles tendon allograft fixation compared with interference screw bone-pattelar tendon-bone autograft fixation at the time of insertion for ACL reconstruction. METHODS: Eleven pairs of cadaveric knees were prepared for ACL reconstruction by disarticulation before graft insertion. The tibia and femur were mounted separately onto an MTS machine and were loaded to failure in line with the tunnels. Femoral fixation for the allograft was provided by a staple anchor; tibial fixation was provided by a suture anchor. Titanium interference screws on the femoral and tibial sides provided autograft fixation. A paired t test was performed to compare mechanical testing results in the 2 groups. RESULTS: Mean maximum load to failure for the allograft was 58.7 N (range, 32.3 to 92.6 N) and 119.6 N (range, 82 to 165.9 N) for the femur and the tibia, respectively, compared with 228.2 N (range, 74.2 to 352 N) and 232.9 N (range, 65.1 to 553.1 N) for the autografts. This difference was statistically significant (P < .001) for femoral fixation, but it was not statistically significant for tibial fixation (P = .186). CONCLUSIONS: Soft tissue Achilles tendon allograft with staple fixation is a significantly weaker fixation construct when compared with autograft bone-patellar tendon-bone with interference screw fixation. CLINICAL RELEVANCE: This study shows significantly weaker fixation in the staple-alograft construct and yet this construct has had at least equivalent results over a 5-year time frame, indicating that rigid femoral fixation may not be a critical factor in long-term results.

Achilles Tendon↗
PubMed2005

Reconstruction of the anterior cruciate ligament with a patella-tendon-bone graft may lead to a permanent loss of bone mineral content due to decreased patellar tendon stiffness.

Immobilisation induces bone loss. Evidence from studies in animals and healthy humans that were immobilised for a limited time indicates that, in general, bone mass may be restored even in adults. Following conservative management of partial tears of the anterior cruciate ligament (ACL), bone loss is often negligible (2-3%). After surgical reconstruction, however, there is greater bone loss (15-20%), with little or no recovery. Bones adapt to the stresses they experience. Also, the largest forces in the musculoskeletal system arise from muscle pull. Tendons transmit these forces. Many surgical techniques for ACL reconstruction use autologous tendon grafts. We hypothesise that tissue harvesting causes weakening of the formerly intact tendon, which, in turn, leads to reduced muscle pull and subsequent bone loss in those parts of the bone that are loaded by the tendon. If our hypothesis holds true, it may change patients' and surgeons' choice of management. Clinical follow-up should assess the functional result with greater scrutiny, possibly including the assessment of bone mineral content. This may be particularly important since there is accumulating evidence that a decrease in bone mineral density (BMD) preceedes, and hence may be a cause of, osteoarthritis.

Animals↗
PubMed1999

Percutaneous tenodesis of the Achilles tendon. A new surgical method for the treatment of acute Achilles tendon rupture through percutaneous tenodesis.

Various studies have shown that the operative treatment of a freshly ruptured Achilles tendon is generally considered to be more appropriate than a nonoperative regimen. However, complications in open reconstructions are reported to occur between 11-29%. We intended to develop a method which reduces the risk of complications arising from operation but simultaneously allows early postoperative mobilization and functional treatment. We developed a percutaneous tenodesis of the Achilles tendon, using two Lengemann extension wires for adaptation of the ruptured tendon. This method of treatment has been applied in 20 patients. The postoperative observation period was one year. All patients were male, their average age was 42 years. The Achilles tendon ruptures occurred during sporting activities and were treated by operation within 22 h on average. The outcome was very good in 95%. One patient (5%) suffered a rerupture due to trauma. There was no other complication.

Achilles Tendon↗
PubMed1998

Flexor tendon repair using a stainless steel internal anchor. Biomechanical study on human cadaver tendons.

We have developed a stainless steel internal tendon anchor that is used to strengthen a tendon repair. This study tested its use in vitro to produce a repair that can withstand the tensile strength demands of early active flexion. Fresh human cadaver flexor digitorum profundus tendons were harvested, divided, and then repaired using four different techniques: Kessler, Becker or Savage stitches, or the internal tendon anchor. The internal splint repairs demonstrated a 99-270% increase in mean maximal linear tensile strength and a 49-240% increase in mean ultimate tensile strength over the other repairs. It is hoped that this newly developed internal anchor will provide a repair that will be strong enough to allow immediate active range of motion.

Cadaver↗
PubMed1991

Tendon subluxation after de Quervain's release: treatment by brachioradialis tendon flap.

Volar subluxation of the tendons of the first dorsal compartment of the wrist occurred in two patients after surgery for treatment of de Quervain's stenosing tenosynovitis. In both patients a painful tenosynovitis of the extensor pollicis brevis and abductor pollicis longus developed, which was unresponsive to conservative therapy as the tendons prolapsed over the prominence of the first dorsal compartment. A distally based flap of the brachioradialis tendon was used to prevent tendon prolapse, with both patients asymptomatic and free of subluxation one and five years after operation.

Adult↗
PubMed1985

The fate of tendon healing after restoration of the integrity of the tendon sheath with autogenous vein grafts.

This experimental study in the chicken model compares the results of sheath closure during primary tendon surgery. Sheath closure after tendon grafting was accomplished by trapdoor of the original sheath, vein patch, and vein conduit. After casting in flexion for 14 days, the operated foot and digits were taken through a full passive range of motion every 3 days. At the 28th postoperative day, all immobilization was removed and free active range of motion and daily perching began. Active flexion was measured after death by continuous traction on the proximal profundus tendon: simulated active flexion. The unoperated contralateral foot served as the control. All operated middle toes achieved significantly greater functional return when the sheath was restored either with trap-door closure, vein conduit, or vein patch compared with simple excision of the sheath. The results indicate the efficacy of sheath closure as well as the possibility of utilizing vein patches or conduits during primary tendon repair.

Animals↗
PubMed1995

Miscellaneous conditions of tendons, tendon sheaths, and ligaments.

The use of diagnostic ultrasonography has greatly enhances our ability to diagnose injuries of tendons and tendon sheaths that were previously either unrecognized or poorly understood. For may of these injuries, there is currently only a small amount of follow-up data. This article considers injuries of the deep digital flexor tendon and its accessory ligament, the carpal tunnel syndrome soft tissue swellings on the dorsal aspect of the carpus, intertubercular (bicipital) bursitis and bicipital tendinitis, injuries of the gastrocnemius tendon, common calcaneal tendinitis, rupture of peroneus (fibularis tertius) and ligaments injuries of the back.

Animals↗
PubMed2002

Actin stress fibres and cell-cell adhesion molecules in tendons: organisation in vivo and response to mechanical loading of tendon cells in vitro.

Tendons consist of parallel longitudinal rows of cells separated by collagen fibres. The cells are in intimate contact longitudinally within rows, and laterally via sheet-like lateral cell processes between rows. At points of contact, they are linked by gap junctions. Since tendons stretch under load, such cell contacts require protection. Here we describe the organisation of the actin cytoskeleton and actin-based cell-cell interactions in vivo and examine the effect of cyclic tensile loading on tendon cells in vitro. Cells within longitudinal rows contained short longitudinally running actin stress fibres. Each fibre was aligned with similar fibres in the cells longitudinally on either side, and fibres appeared to be linked via adherens junctions. Overall, these formed long oriented rows of stress fibres running along the rows of tendon cells. In culture, junctional components n-cadherin and vinculin and the stress fibre component tropomyosin increased in strained cultures, whereas actin levels remained constant. These results suggest that: (1) cells are linked via actin-associated adherens junctions along the line of principal strain; and (2) under load, cells appear to attach themselves more strongly together, and assemble more of their cytoplasmic actin into stress fibres with tropomyosin. Taken together, this suggests that cell-cell contacts are protected during stretch, and also that the stress fibres, which are contractile, may provide an active mechanism for recovery from stretch. In addition, stress fibres are ideally oriented to monitor tensile load and thus may be important in mechanotransduction and the generation of signals passed via the gap junction network.

Actins↗
PubMed2001

Comparisons of intraosseous graft healing between the doubled flexor tendon graft and the bone-patellar tendon-bone graft in anterior cruciate ligament reconstruction.

PURPOSE: The purpose of this study was to compare intraosseous graft healing between the doubled flexor tendon (FT) graft and the bone-patellar tendon-bone (BPTB) graft in anterior cruciate ligament (ACL) reconstruction. TYPE OF STUDY: Randomized trial. METHODS: A biomechanical and histologic study was conducted with 24 adult beagle dogs. Bilateral ACL reconstructions were performed in each animal. Autogenous doubled FT and BPTB grafts were used for the left and right knees, respectively. Each end of the 2 grafts was tethered with a polyester suture to a screw post with a washer. The animals were then allowed unrestricted activities in their cages. Eight animals were killed at 3, 6, and 12 weeks, respectively. RESULTS: Histologically, the FT graft was anchored to the tunnel wall with newly formed collagen fibers resembling Sharpey's fibers by 12 weeks. These fibers were more abundant in the anterior (ventral) gap than in the posterior (dorsal) gap. In the BPTB graft, the bone plug was anchored with newly formed bone at 3 weeks, although osteocytes in the plug trabeculae were necrotic for 12 weeks. Degeneration of the tendon-bone junction in the plug progressed at 6 weeks. Tensile testing showed that the weakest site was different not only between the 2 grafts but also between the observation periods. In the FT graft, the weakest site was the graft-wall interface at 3 weeks and the intraosseously grafted tendon at 6 weeks. In the BPTB graft, the weakest site was the graft-wall interface at 3 weeks and the proximal site in the bone plug at 6 weeks. The ultimate failure load of the FT graft was significantly inferior (45.8%) to that of the BPTB graft at 3 weeks (P =.021). At 6 weeks, the load of the FT graft was 85% that of the BPTB graft without a significant difference (P =.395). CONCLUSIONS: As to the clinical relevance, the fixation device chosen for soft-tissue fixation appears to be more important than comparing it to the BPTB graft, although this has yet to be conclusively proven.

Animals↗
PubMed2001

[Modified collateral ligament reconstruction with the tendon of the abductor pollicis tendon in treatment of chronic radial instability of the basal thumb joint].

Injuries to the radial collateral ligament of the MP joint of the thumb occur much less frequently than injuries to the ulnar collateral ligament. Ligament injury is usually a result of direct trauma. The resultant instability to the thumb usually impairs hand function. In acute lesions to the radial collateral ligament, direct repair is often possible. In cases of chronic radial joint instability, secondary ligament reconstruction with a free tendon graft, most commonly the palmaris longus tendon, is usually recommended. We describe another technique using the tendon insertion of the abductor pollicis brevis muscle. The tendon inserting distally can be used as a stable ligament after dividing it at the border to the muscle and attaching it to the head of the metacarpal bone with a wire. The follow-up for six patients treated by this method showed good and painless stability and function of the thumb in a time span of one year.

Chronic Disease↗
PubMed2003

[Internal rotational strength of the thigh after ACL reconstruction. Prospective comparison of harvesting of the semitendinosus and gracilis tendons and the patella tendon].

AIM: The aim of the present study was the prospective, randomized evaluation of the internal rotation strength in patients, undergoing ACL reconstruction using either semitendinosus and gracilis tendon autografts (ST/G) or the central third of the patella tendon (BPT). METHOD: 40 patients (20 male, 20 female, average age 32 years [16 - 49]) underwent reconstruction of the ACL. In 20 patients ST/G was used, in 20 matched patients the central third of the patella tendon (BPT) was used. Rehabilitation was identical for both groups. The isometric strength of internal tibial rotation in neutral position was measured preoperatively, 3, 6 and 12 months postoperatively. RESULTS: After 3 months no difference to the preoperative data was found. After six months the internal tibial torque was significantly higher (p < 0.05) than preoperatively. No additional increase was found after 12 months. There was no statistically significant difference between both groups at any time. CONCLUSION: The internal tibial torque, which is predominantly a function of the pes anserinus, recovers shortly after operation and is, due to postoperative rehabilitation, significantly elevated after 6 months. The randomized comparison with the harvesting of the central third of the patellar tendon showed no significant difference.

Adolescent↗