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At least 181 records · Page 10Linked to original sources
PubMed2002

Reconstruction of chronic ruptures of the distal biceps tendon with use of an achilles tendon allograft.

BACKGROUND: Chronic ruptures of the distal biceps tendon are uncommon and are complicated by the retraction and poor quality of the muscle and tendon. Surgical procedures that have been described for the treatment of this injury are limited by the quality and availability of the structures used for augmentation. The purpose of the present study was to describe the surgical technique for reconstruction of the tendon with an Achilles tendon allograft and to report our preliminary experience with this procedure. METHODS: An Achilles tendon allograft was used to reconstruct a chronic rupture of the distal biceps tendon in four patients. The patients were evaluated with regard to subjective satisfaction, pain, range of motion, and strength in flexion and supination. The results were graded with use of the Mayo elbow performance score. RESULTS: After an average duration of follow-up of 2.8 years (range, 2.0 to 3.7 years), all four patients had a satisfactory subjective result, a full range of motion, and an excellent Mayo elbow performance score. The strength of flexion and supination was comparable with that on the contralateral side in two patients and was slightly decreased in the other two. CONCLUSIONS: Reconstruction of chronic disruptions of the distal biceps tendon with an Achilles tendon allograft appears to offer a satisfactory technical solution for this challenging problem and has provided satisfactory clinical results to date.

Achilles Tendon↗
PubMed2004

Three-dimensional muscle-tendon geometry after rectus femoris tendon transfer.

BACKGROUND: Rectus femoris tendon transfer is performed in patients with cerebral palsy to improve knee flexion during walking. This procedure involves detachment of the muscle from its insertion into the quadriceps tendon and reattachment to one of the knee flexor muscles. The purpose of the present study was to evaluate the muscle-tendon geometry and to assess the formation of scar tissue between the rectus femoris and adjacent structures. METHODS: Magnetic resonance images of the lower extremities were acquired from five subjects after bilateral rectus femoris tendon transfer. A three-dimensional computer model of the musculoskeletal geometry of each of the ten limbs was created from these images. RESULTS: The three-dimensional paths of the rectus femoris muscles after transfer demonstrated that the muscle does not follow a straight course from its origin to its new insertion. The typical muscle-tendon path included an angular deviation; this deviation was sharp (>35 degrees ) in seven extremities. In addition, scar tissue between the transferred rectus femoris and the underlying muscles was visible on the magnetic resonance images. CONCLUSIONS: The angular deviations in the rectus femoris muscle-tendon path and the presence of scar tissue between the rectus femoris and the underlying muscles suggest that the beneficial effects of rectus femoris tendon transfer are derived from reducing the effects of the rectus femoris muscle as a knee extensor rather than from converting the muscle to a knee flexor. These findings clarify our understanding of the mechanism by which rectus femoris tendon transfer improves knee flexion.

Adolescent↗
PubMed1990

Transfer of the pronator teres tendon to the tendons of the flexor digitorum profundus in tetraplegia.

In eleven patients who had traumatic tetraplegia, the pronator teres tendon was transferred to the flexor digitorum profundus tendons to restore active flexion of the fingers. At the same time, in ten of these patients the tendon of the brachioradialis was transferred to the tendon of the flexor pollicis longus, and in the eleventh patient the brachioradialis tendon was transferred to the tendon of the flexor digitorum superficialis of the small finger, to restore pinch. The average time between injury and operation was thirty-four months. The average length of follow-up after operation was thirty-four months. Ten patients gained functional active flexion of the fingers, and they reported improved performance of activities of daily living. When the wrist was in 30 degrees of extension, the average active grasp strength was twenty-one millimeters of mercury and the average key-pinch strength was 2.2 kilograms. The average active flexion of the fingers from the resting position, measured from the tip of the finger to the distal palmar crease, was 1.5 centimeters. Only one patient did not gain active flexion of the fingers. Of the entire group, this patient had the least function of the hand on preoperative evaluation; retrospectively, he seemed to be a poor candidate for operation, since the strength of the pronator teres muscle and the sensibility of the hand were insufficient for useful function. We concluded that, in selected tetraplegic patients, transfer of the pronator teres tendon to the flexor digitorum profundus tendons provides useful active flexion of the fingers.

Adult↗
PubMed1987

A method of repair for quadriceps tendon or patellar ligament (tendon) ruptures without cast immobilization. Preliminary report.

The quadriceps tendon and patellar tendon (ligament) were repaired with a Dacron vascular graft used as a tension suture material. In cases of quadriceps tendon ruptures, the Dacron graft is passed transversely through the patellar ligament just below the patella and crossed transversely at the level of the musculotendinous junction with two loops applying tension to the tendon, which brings the tendon ends together by creating a solid structure. In cases of patellar ligament ruptures, the Dacron graft is passed through a hole in the tibia posteriorly to the tibial tuberosity instead of through the patellar ligament below the patella. This technique enables early mobilization on the first day after surgery. The technique was first tested on six dogs with severed quadriceps tendons and patellar ligaments that were repaired with this suture method. All of the animals recovered from surgery and walked and ran normally on the repaired legs within 27 days and with only mild limping after 17 days. The technique was then used on six patients, four with complete quadriceps tendon rupture and two with complete tear (avulsion) of the patellar ligament (tendon). In all of the patients, excellent surgical results were obtained and leg immobilization was virtually eliminated. Physical therapy was prescribed the first day after surgery. The rehabilitation period was significantly reduced.

Animals↗
PubMed1985

[Experimental studies on the healing and restoration of gliding function of the injured digital flexor tendon. Part 9: The use of drugs to prevent adhesion formation of the injured tendon].

In order to prevent the formation of restrictive adhesion without influencing tendon healing, hyaluronic acid and triamcinolone were given topically between a scarred tendon and gliding floor. The third digits of female broiler chickens were used. Three factors of tendon adhesion were elicited, namely, injury to the tendon, tendon sheath and gliding floor. Standard adhesion was established from all factors in addition to the cast immobilization. The above-mentioned procedure was used as a standard adhesion model in the following experiments. Hyaluronic acid, triamcinolone and ganglion contents were applied topically just after the above-mentioned procedure. After three weeks of immobilization, the state of tendon adhesion and tendon healing was observed. Triamcinolone, 0.05 mg, had an adhesion-preventing action, but the effective dose of this agent had only narrow limits. Hyaluronic acid, 1% and 0.5%, was more effective than triamcinolone in the prevention of adhesion and did not interfere with the tendon healing. Ganglion contents had a slight effect on the prevention of adhesion.

Administration, Topical↗
PubMed1995

Tendon response to tensile stress: an ultrastructural investigation of collagen:proteoglycan interactions in stressed tendon.

Tendons are parallel arrays of collagenous fibres which are specialised to resist and transmit tensile stresses. The response of tendon fibres to tensile stress is age-dependent and complex. Elastic elongation at low stress is accompanied by the disappearance of alternate light and dark bands seen in transmitted polarised light. This region of the stress/strain curve is associated with straightening of fibre 'crimps'. At higher stress, elongation is still elastic and reversible until break point is reached. This behaviour may be associated with straightening of a helical arrangement of collagen fibrils. In addition to the collagen fibrils, there are transverse and longitudinal proteoglycan filaments, many of which bridge and link between the fibrils. We have investigated the effect of various levels of stress from very low up to breaking point on the appearance of the proteoglycan filaments and their relationships with the collagen fibrils. Proteoglycan-collagen fibril interactions in rat and mouse tail and flexor digitorum tendons were visualised by Cupromeronic blue staining, applied to dissected fibres in the resting state and at stresses up to breaking. Proteoglycan filaments were seen to be orthogonally arranged in every D period, probably at the d band in mature tendons. In immature tendons proteoglycan filaments took up more varied orientations, but were mainly orthogonal or axially arranged with respect to the collagen fibrils. Both pictures appeared unchanged after application of stress of any level up to breaking point. Young tendons ruptured at lower stresses than mature tendons. It is suggested that PG bridges between collagen fibrils play a part in transmitting and resisting tensile stresses in tendons, contributing to the strength of the tissue.

Animals↗
PubMed1993

Morphologic changes in the human patellar tendon after bone-tendon-bone anterior cruciate ligament reconstruction.

Magnetic resonance imaging (MRI) was performed on 15 patients, an average of 2.5 years after arthroscopically assisted bone-tendon-bone (BTB) anterior cruciate ligament (ACL) reconstruction, to evaluate the patellar tendon donor site. Five patients who had arthroscopically assisted ACL reconstruction using the semitendinosus tendon as a graft also were scanned bilaterally and evaluated. The mean difference between the involved and uninvolved patellar tendon length was -0.2 mm for the BTB patients and -2.6 mm for the semitendinosus patients. The mean difference between patellar tendon width for the BTB patients was 1.1 mm and 1.9 mm for the semitendinosus patients. The mean difference between patellar tendon thickness was 0.4 mm for the BTB surgery group and 0.02 mm for the semitendinosus surgery group. None of the differences were statistically significant. Results indicate that harvesting the central one third of the patellar tendon does not significantly affect the length, width, or thickness of the tendon at least 22 months after arthroscopically assisted BTB-ACL.

Adolescent↗
PubMed1995

Anatomy of the Achilles tendon (tendo calcaneus) with respect to tendon thickness measurements.

267 normal controls of different ages underwent achilles tendon thickness measurements by ultrasonography (US) for reference. 96 recruits and 10 young women additionally underwent magnetic resonance imaging of the achilles tendons and calves for more systematic evaluation of the factors influencing tendon thickness. Children under 10 had a tendon thickness (mean +/- SD) of 4.6 +/- 0.8 mm, 10-17 year-olds 6.1 +/- 0.8 mm, 18-30 year-olds 6.3 +/- 0.5 mm and over 30 year-olds 6.9 +/- 1.0 mm. Women had slightly thinner tendons than men, but the difference was statistically significant only in the oldest age group. Normal variation in shape of the tendon caused up to a 25% variation in the measured thickness values. In the large sample of recruits a statistically significant correlation was found between the tendon thickness and body height. Differences in population height could account for the measured differences in normal achilles tendon thickness found in studies on Japanese subjects compared with studies on European and American subjects.

Achilles Tendon↗
PubMed2005

Gliding resistance of the extensor pollicis brevis tendon and abductor pollicis longus tendon within the first dorsal compartment in fixed wrist positions.

PURPOSE: While the etiology of de Quervain's disease is unknown, repetitive motion coupled with awkward wrist position and septation within the first dorsal compartment are considered causative factors. We hypothesize that these conditions might produce high gliding resistance, which could then induce micro-damage of the tendons and retinaculum. The purpose of this study was to measure the gliding resistance of the extensor pollicis brevis and abductor pollicis longus tendons within the first dorsal compartment in a human cadaver model. METHODS: Fifteen human cadaver wrists, which included eight septation and seven non-septation wrists in the first dorsal compartment, were used. Gliding resistance of the extensor pollicis brevis and abductor pollicis longus tendons was measured in seven wrist positions: 60 degrees extension, 30 degrees extension, 0 degrees, 30 degrees flexion, 60 degrees flexion in neutral deviation and 30 degrees ulnar deviation, 15 degrees radial deviation in neutral extension/flexion. RESULTS: The overall gliding resistance was not different between septation and non-septation wrists (0.21 versus 0.19 N for abductor pollicis longus and 0.21 versus 0.15 N for extensor pollicis brevis, respectively), but there was a significant effect on gliding resistance due to wrist position (p<0.05) in both tendons. Interaction between wrist position and septation status was observed in the extensor pollicis brevis tendon (p<0.05). With septation, the gliding resistance of the extensor pollicis brevis was significantly higher in 60 degrees wrist flexion (0.51 N) compared to all other wrist positions tested (all less than 0.26 N) (p<0.05). In the non-septation group, gliding resistance was significantly higher in 60 degrees flexion (0.20 N) and 60 degrees extension (0.22 N) compared to the other five wrist positions (all less than 0.15 N) (p<0.05). Although no significant difference was observed, the extensor pollicis brevis tendon with septation tended to have higher gliding resistance than that without septation in wrist flexion. In 60 degrees of wrist flexion the abductor pollicis longus tendon had significantly higher gliding resistance (0.33 N) than the other wrist positions (all less than 0.26 N) (p<0.05). CONCLUSIONS: A combination of septation and wrist position significantly affected extensor pollicis brevis tendon gliding resistance in this cadaver model. These factors may contribute to the development of de Quervain's disease.

Biomechanical Phenomena↗
PubMed1998

Moment arms of the digital flexor tendons at the wrist: role of differential loading in stability of carpal tunnel tendons.

When a flexor digitorum superficialis tendon crossing a flexed or extended wrist has a load applied to it in excess of that applied to adjacent tendons, that tendon may translate across the carpal tunnel. In 6 cadaver specimens, each of the 9 carpal tunnel tendons was loaded with a baseline tension of 85 g and the moment arms of the flexor pollicis longus and the 4 flexor digitorum superficialis tendons were determined. Applying a higher 540-g load to individual flexor digitorum superficialis tendons and the flexor pollicis longus while loading the remaining tendons with the baseline 85-g tension significantly changed the moment arms from those measured under baseline load. The results demonstrated that tendons with applied differential loads in the carpal tunnel shift their positions, as revealed by their changing moment arms.

Analysis of Variance↗
PubMedDate not supplied

Restoration of tensile properties at tendon insertion to bone by a patellar tendon-tibia autograft: an experimental study with canine infraspinatus.

A free patellar tendon-tibia autograft was performed to reconstruct a tendon insertion to bone of the canine infraspinatus. In this experimental study restoration of mechanical properties at tendon insertion to bone of the patellar tendon-tibia autograft was examined on 0, 42, and 84 postoperative days. Five dogs were used for each time point. Bone union occurred in all grafts by 6 postoperative weeks. The ultimate strength at the tendon insertion to bone recovered from 255.5 N on 0 day to 264.3 N and 439.3 N on 42 and 84 postoperative days, respectively. Stiffness recovered from 141.8 KN/m on 0 day to 201.8 KN/m and 226.3 KN/mN on 42 and 84 postoperative days, respectively. Our results demonstrate that patellar tendon-tibia autograft maintains excellent mechanical properties at tendon insertion to bone in the early healing period. This result suggests that transfer or free graft of tendons with attaching bone plug has a mechanical advantage for reconstruction of the rotator cuff, which may allow the patient to institute early postoperative mobilization.

Animals↗
PubMed2004

Periosteal augmentation of a tendon graft improves tendon healing in the bone tunnel.

Secure fixation of tendon or ligament to bone has been a challenging problem. The periosteum is an osteogenic organ that regulates bone growth and remodeling at the outer surface of cortical bone and also is known to play an important role in forming a tendon insertion site to bone. Therefore, we hypothesized that a freshly harvested periosteum can be used as a stimulative scaffold to biologically reinforce the attachment of tendon graft to bone. Using a rabbit hallucis longus tendon and calcaneus process model, we found that a periosteal augmentation of a tendon graft could enhance the structural integrity of the tendon-bone interface, when the periosteum is placed between the tendon and bone interface with the cambium layer facing toward the bone. Clinically, the use of an autogenous periosteum patch would be an optimal choice for biologic augmentation of the tendon graft in the bone tunnel, because the tissue is readily available for harvest from the patient's body.

Analysis of Variance↗
PubMed2004

Medial canthal tendon repair for moderate to severe tendon laxity.

BACKGROUND: Medial canthal tendon laxity is a common cause of epiphora and ocular irritation. It is difficult to treat due to the proximity of the lower canaliculus and punctum to the tendon. METHODS: The results of a prospective series of patients with involutional medial canthal tendon laxity between 1997 and 2002 were reviewed. Symptoms and measured laxity were recorded before and after medial canthal tendon repair. The medial canthal tendon was routinely repaired through a cut along the lid margin extending from the punctum medially. This avoids a vertical cut onto the anterior lamella of the eyelid, which is useful if a skin graft is required. RESULTS: Twenty lower eyelid medial canthal tendon repairs were performed on 17 patients. Preoperatively, the lower punctum in all patients was able to be distracted to the medial limbus or further and in 50% of cases, the lower lid punctum was able to be distracted to the pupil midline or further. Postoperatively all patients had reduction of their medial canthal tendon laxity. Postoperatively in 85% of cases the lower punctum was not able to be distracted beyond the medial limbus; however, 15% of cases still had significant residual laxity. Eighty-five per cent of patients reported improvement in symptoms. CONCLUSIONS: This is an effective procedure in the majority of patients with moderate to severe medial canthal tendon laxity; however, residual lower lid laxity persisted in some patients.

Aged↗
PubMedDate not supplied

Patellar tendon or semitendinosus tendon autografts for anterior cruciate ligament reconstruction? A prospective randomized study with a two-year follow-up.

BACKGROUND: There are well-known problems with the use of bone-patellar tendon-bone autografts for anterior cruciate ligament reconstruction, especially in terms of donor site morbidity. Hamstring tendon grafts have been increasingly used as an alternative, but there are very few controlled studies comparing the methods. HYPOTHESIS: Use of semitendinosus tendon grafts will cause less donor site morbidity and result in better knee-walking ability. STUDY DESIGN: Prospective randomized clinical trial. METHODS: Seventy-one patients who had a unilateral anterior cruciate ligament rupture underwent arthroscopic reconstruction with interference screw fixation and use of either bone-patellar tendon-bone or semitendinosus tendon graft. Outcome assessment was performed by physiotherapists not involved in the patients' care. RESULTS: At the 2-year follow-up, no differences were found in terms of the Lysholm score, Tegner activity level, KT-1000 arthrometer side-to-side laxity measurement, single-legged hop test, or International Knee Documentation Committee classification results. The knee-walking test was rated difficult or impossible to perform by 53% of the bone-patellar tendon-bone group and by only 23% of the semitendinosus graft patients, a significant difference. CONCLUSIONS: The semitendinosus tendon graft is at least an equivalent option to the bone-patellar tendon-bone graft for anterior cruciate ligament reconstruction, and we recommend its use.

Adolescent↗
PubMedDate not supplied

A randomized comparison of patellar tendon and hamstring tendon anterior cruciate ligament reconstruction.

BACKGROUND: Patellar and hamstring tendon autografts are the most frequently used graft types for anterior cruciate ligament reconstruction, but few direct comparisons of outcomes have been published. HYPOTHESIS: There is no difference in outcome between the two types of reconstruction. STUDY DESIGN: Prospective randomized clinical trial. METHODS: After isolated anterior cruciate ligament rupture, 65 patients were randomized to receive either a patellar tendon or a four-strand hamstring tendon graft reconstruction, and results were reviewed at 4, 8, 12, 24, and 36 months. RESULTS: Pain on kneeling was more common and extension deficits were greater in the patellar tendon group. There were greater quadriceps peak torque deficits in the patellar tendon group at 4 and 8 months but not thereafter. In the hamstring tendon group, active flexion deficits were greater from 8 to 24 months, and KT-1000 arthrometer side-to-side differences in anterior knee laxity at 134 N were greater. Cincinnati knee scores, International Knee Documentation Committee ratings, and rates of return to preinjury activity levels were not significantly different between the two groups. CONCLUSIONS: Both grafts resulted in satisfactory functional outcomes but with increased morbidity in the patellar tendon group and increased knee laxity and radiographic femoral tunnel widening in the hamstring tendon group.

Adolescent↗
PubMed2005

[The use of N-butyl-2-cyanoacrylate (Histoacryl) in primary tendon repair: a biomechanical study with sheep flexor tendons].

OBJECTIVES: In this study, the biomechanical properties of peripheral tendon repair with the use of epitendinous suture technique and N-butyl-2-cyanoacrylate (Histoacryl) (NBSA), a biodegradable glue, were compared. METHODS: Twenty-four flexor tendons were harvested from sheep hind limbs. Following transection of the tendons, 12 tendons (group 1) were repaired with modified Kessler core sutures using no 2 prolene and epitendinous running sutures with 3/0 prolene. In the other 12 tendons (group 2), NBSA was applied between the cut surfaces before placing modified Kessler core sutures. Placed on an hydrolic test machine, half of the tendons from each group were subjected to load to failure with a tensile force of 20 mm/min and the other half to cyclic loading with a tensile loading between 1-15 N at a rate of 20 cycles/min. Observation of a gap of 1 mm between the tendon ends in each test was regarded as repair failure. RESULTS: The mean load to failure was 27.3 N (range 25 to 32 N) for group 1 and 50.4 N (range 32 to 63 N) for group 2 (p=0.022). The mean number of cycles at failure was 140 (range 45 to 250) in group 1 and 350 (range 150 to 600) in group 2 (p=0.032). CONCLUSION: Our results showed that peripheral tendon repair with the use of NBSA has biomechanical advantages over repair with the epitendinous running suture technique.

Animals↗
PubMed1991

An experimental study on the application of a hydroxyapatite artificial tendon sheath to prevent adhesions after tendon repair (Part 1).

The formation of adhesions around the lacerated flexor tendons in zone II was studied in chickens after using an artificial tendon sheath made of hydroxyapatite (HAp). The flexor sheath was excised between the proximal and distal pulleys in zone II to create a window in the fibro-osseous tunnel. After suturing the severed profundus tendon, an HAp sheath was placed around the suture site followed by 3 weeks of immobilization. The results were compared with controls in which no HAp sheaths were used after the operation. Adhesion formation was assessed both biomechanically and histologically. The mobility of the tendons was better in the HAp group at all the periods studied. HAp sheath was not firmly adherent to either the granulation tissue or the surface of the tendon. Histology at 3 as well as 6 weeks in HAp groups revealed epitenon-like structure on the tendon surface including the tenorrhaphy site and a wide space around the tendon after the HAp sheath was removed. The outer margins of this space was lined by a layer of fibrocyte-like cells and collagen fibers thereby resembling new formed tendon sheath. In the cases of control, marked peritendinous adhesions were observed.

Animals↗
PubMed1990

[Controlling and supporting apparatus of the deep finger flexor tendon and the long extensor tendon of the thumb. Clinico-anatomical analysis].

Full function of finger flexion requires an intact pulley system. After destruction of the pulleys, reconstruction over the metacarpal head (A1) and over the center of the proximal and middle phalanges (A2, A4) should be carried out. Calculations on a computer model suggest that the reconstructed pulley must hold the tendon close to the underlying bone. Width of the pulley and distance from the next proximal or distal joint of the inserted pulley are of minor functional importance. The amount of maximum load on the pulley, exceeding the tension of the tendon, must be considered in operation and postoperative treatment. The extensor pollicis longus tendon lies at the dorsal tubercle (tubercle of Lister) within an osseous gliding surface, where it changes direction. The deviation angle depends on the radiocarpal position and causes, in addition to the usual tension, a pressure stress to that part of the tendon. A graphical analysis of statics, based on X-rays, demonstrates maximum loads on the gliding surface. They can increase in relation to the tension force of the tendon to about 50% in the antero-posterior and to 100% in the radioulnar projection. Densitography of the distal radius shows a maximum of density where the dorsal tubercle is most prominent. Nutritional problems of that tendon are predisposed by that particular mechanical stress. Therefore spontaneous rupture of the extensor pollicis longus tendon in patients with rheumatoid arthritis or after fracture of the distal radius occurs, though infrequently. In the case of immobilization, slight ulnar abduction within the radiocarpal joint remarkably reduces the tension and pressure stresses on the tendon.

Computer Simulation↗