Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Tenotomy”

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 739 records · Page 41Linked to original sources

Healing of transected equine superficial digital flexor tendons with and without tenorrhaphy.

Healing of transected superficial digital flexor tendons was evaluated mechanically and histologically in eight horses. Tendons sutured with polyglyconate had higher loads at failure than nonsutured tendons at weeks 5 and 9. The tendon stress at failure (force per unit area) was higher in the sutured tendons at week 5 but not at week 9, reflecting the increased size of the scar at week 9. Histologically, scars after tenorrhaphy were consistently more mature than nonsutured tenotomy scars. The mean maturity score for sutured tendons was higher than for nonsutured tendons at weeks 5 and 9. Overall, these data support tenorrhaphy with absorbable suture.

Animals↗

Exposure and postoperative stability of three medial surgical approaches to the canine elbow.

Articular cartilage exposure and immediate postoperative stability provided by three medial surgical approaches in canine cadaver elbows were compared. The approaches evaluated were a desmotomy of the medial collateral ligament (DMCL) that included a tenotomy of the pronator teres muscle, a longitudinal myotomy of the flexor carpi radialis (MFCR), and an osteotomy of the medial epicondyle (OME). Nondestructive biomechanical testing was performed before the surgical approach and repeated after surgery. The stiffness at 13 degrees valgus deviation of the elbow and energy absorption up to 13 degrees valgus deviation of the elbow were determined from the preoperative and postoperative torque-rotation curves. The perimeters of the ulnar and humeral articular cartilage that were visualized through the approach were scored with a dental pick. Latex casts were made of articular surfaces of the elbow. The humeral and ulnar articular exposures were determined by computerized planimetric analysis of latex cast photocopies. The humeral cartilage exposure of the OME approach was significantly greater than either the MFCR or DMCL approaches. The DMCL approach provided a significantly greater humeral cartilage exposure than the MFCR approach. All three approaches provided statistically similar percentages of ulnar cartilage exposure. The stiffness and energy absorption of the OME and MFCR approaches were similar and significantly greater than the DMCL approach. The OME approach provided the best combination of exposure and immediate postoperative stability.

Animals↗

Evaluation of an autologous tendon graft repair method for gap healing of the deep digital flexor tendon in horses.

A sutured tenorrhaphy technique that incorporated an autologous tendon graft was compared mechanically and histologically with a sutured tenorrhaphy at 6, 12, and 24 weeks after repair. Tenorrhaphy was performed in the forelimb tendon of the deep digital flexor muscle and the graft was taken from the hindlimb tendon of the lateral digital extensor muscle; one forelimb site included the graft, whereas the other forelimb site was not grafted. Tenotomies were made immediately proximal to the insertion of the accessory ligament into the tendon of the deep digital flexor muscle. Grafted and nongrafted tenorrhaphies were sutured with 2 polydioxanone in a modified double locking-loop pattern. Limbs were supported with a bandage and an extended elevated heel shoe that maintained the dorsal hoof wall angle at 70 degrees to 75 degrees; this support was removed at 12 weeks and dorsal hoof wall angle was maintained at 40 degrees to 45 degrees for the remainder of the study. Gap formation (2.5 +/- .3 cm) was evident at all tenorrhaphy sites at 3 days on ultrasound examination. In grafted repairs, the breaking stress was increased (P < .001) between 6 weeks (2.56 +/- .44 MPa) and 12 weeks (17.69 +/- 7.68 MPa), with grafted tendon having a greater breaking stress than nongrafted tendon (8.77 +/- 2.5 MPa; P < .05). No differences in breaking stress were evident at 24 weeks. At 12 weeks, repair tissue in grafted tendon was histologically more mature, had less cellularity, better fibroblast orientation and more homogeneous collagen matrix than nongrafted tendon. Polydioxanone suture was still evident histologically at 24 weeks and was associated with minimal cellular reaction. Incorporation of an autologous tendon graft improved the mechanical properties and histological quality of the repair tissue in equine flexor tenorrhaphies at 12 weeks but not at 24 weeks after repair.

Animals↗

Effects of function and weight-bearing on the healing of full-thickness cartilage defects in rats.

The effects of different degrees of active motion were studied in 30 male Wistar rats. In all rats a full-thickness cartilage defect of 1.0 mm in diameter was made in the medial condyle of both femurs. The rats were then allocated to the following three groups; i) exercising group which followed a 4-week training program of moderate intensity, ii) a non-weight-bearing group in which unilateral achilles tenotomy was made to reduce weight-bearing and iii) control rats which were allowed normal cage activity. Healing of the defect was evaluated by planimetric analysis and histologic evaluation. Effects of the training program was confirmed by a lesser weight increase in the exercise group. Planimetric analysis revealed no differences between the groups in the area of the original defect at the end of the experiment. There were no differences in healing ratio (area of healing/area of original defect) between the exercise and control groups, whereas the healing ratio was increased in the non-weight-bearing limbs compared with control and exercised rats. The favorable effect of non-weight-bearing was further indicated by differences in healing ratio between the two limbs in the non-weight-bearing group. Histological evaluation showed that the defect was repaired by a fibrocartilage substance along the periphery of the original defect and fibrovascular granulation tissue centrally. Evaluated by microscopic appearance, there were no qualitative differences between the three groups. We conclude that in the initial repair process by fibrocartilage non-weight-bearing is conductive to healing of full-thickness cartilage defects. The short-term effects revealed no differences on qualitative healing. Increased activity does not seem to prolong the initial fibrocartilage healing compared with normal activity with full weight-bearing.

Animals↗

Adaptation of muscle size and myofascial force transmission: a review and some new experimental results.

This paper considers the literature and some new experimental results important for adaptation of muscle fiber cross-sectional area and serial sarcomere number. Two major points emerge: (1) general rules for the regulation of adaptation (for in vivo immobilization, low gravity conditions, synergist ablation, tenotomy and retinaculum trans-section experiments) cannot be derived. As a consequence, paradoxes are reported in the literature. Some paradoxes are resolved by considering the interaction between different levels of organization (e.g. muscle geometrical effects), but others cannot. (2) An inventory of signal transduction pathways affecting rates of muscle protein synthesis and/or degradation reveals controversy concerning the pathways and their relative contributions. A major explanation for the above is not only the inherently limited control of the experimental conditions in vivo, but also of in situ experiments. Culturing of mature single Xenopus muscle fibers at high and low lengths (allowing longitudinal study of adaptation for periods up to 3 months) did not yield major changes in the fiber cross-sectional area or the serial sarcomere number. This is very different from substantial effects (within days) of immobilization in vivo. It is concluded that overall strain does not uniquely regulate muscle fiber size. Force transmission, via pathways other than the myotendinous junctions, may contribute to the discrepancies reported: because of substantial serial heterogeneity of sarcomere lengths within muscle fibers creating local variations in the mechanical stimuli for adaptation. For the single muscle fiber, mechanical signalling is quite different from the in vivo or in vitro condition. Removal of tensile and shear effects of neighboring tissues (even of antagonistic muscle) modifies or removes mechanical stimuli for adaptation. It is concluded that the study of adaptation of muscle size requires an integrative approach taking into account fundamental mechanisms of adaptation, as well as effects of higher levels of organization. More attention should be paid to adaptation of connective tissues within and surrounding the muscle and their effects on muscular properties.

Adaptation, Physiological↗

Effect of rat soleus muscle overload on neuromuscular transmission efficacy during continuous and intermittent activation.

Increased neuromuscular activity is known to provoke morphological and functional adaptations at the neuromuscular synapse. Most of these changes have been documented following endurance exercise training programmes. In this study, the effect of rat soleus muscle overload produced by tenotomy plus voluntary wheel-cage activity on neuromuscular transmission efficacy was investigated. The overload protocol increased miniature endplate potential (MEPP) and endplate potential (EPP) amplitudes by 17 and 19%, respectively (both P < 0.01), and increased MEPP frequency by 86% (P < 0.01). EPP amplitude rundown during continuous trains of activation was attenuated by approximately 10% in the overloaded group (P < 0.01). Also, during intermittent activation, the overload protocol attenuated EPP amplitude rundown, mainly by enhancing EPP amplitude recovery by approximately 10% during the quiescent periods (P < 0.01). Although the present results show that both the degree and direction of adaptation are similar to what has been observed at rat soleus neuromuscular junctions following an endurance training protocol, there are important nuances between the results, suggesting different mechanisms through which these changes may occur.

Adaptation, Physiological↗

The importance of peripheral changes in determining the sensitivity of striated muscle to depolarizing drugs.

1. The sensitivity of the flexor digitorum longus and soleus muscles to depolarizing drugs was tested after cross-union of their respective motor nerves.2. The alien innervation did not affect the sensitivity of either the flexor digitorum longus (FDL) or soleus muscles, which retained their normal characteristic responses to decamethonium and suxamethonium. The time course of muscle contractions was, however, altered by the cross-union operation.3. A considerable increase in sensitivity to depolarizing drugs was shown after de-afferentation and after tenotomy of the soleus muscles. Both these conditions are associated with muscle atrophy.4. It is suggested that hypersensitivity to depolarizing drugs can be expected in any situation where the muscle is undergoing atrophy.

Animals↗

Relationship between cortisone and muscle work in determining muscle size.

1. Large doses of cortisone caused marked atrophy of the plantaris muscle and other pale muscles of hind limbs of hypophysectomized rats, but hormone treatment had little effect on the size of the red soleus muscle.2. Denervation increased the sensitivity of the soleus and plantaris to the catabolic effects of cortisone.3. Increased work induced by tenotomy of the synergistic gastrocnemius made the plantaris muscle less sensitive to cortisone-induced atrophy.4. Since the catabolic effects of cortisone are more pronounced in the less active muscles, it is suggested that in mobilizing body protein for gluconeogenesis the hormone spares those muscles physiologically most active.5. The rapidity with which muscles lose weight in response to cortisone indicates that the hormone must decrease protein half-lives as well as decrease protein synthesis.

Animals↗

The influence of activity on some contractile characteristics of mammalian fast and slow muscles.

1. The time course of contraction and relaxation in the isometric twitch of a rabbit soleus muscle becomes more rapid following tenotomy and spinal cord section. This increase in speed could be prevented by long-term electrical stimulation at frequencies of 5 or 10/sec. It was not prevented by stimulation at frequencies of 20 or 40/sec.2. Long-term electrical stimulation of fast rabbit and cat muscles at a frequency of 10/sec had a slowing effect on the time course of contraction and relaxation.3. It is concluded that the almost continuous low frequency discharge of motoneurones innervating postural muscles plays an important part in establishing and maintaining the slow time course of contraction of these muscles. The characteristically different speeds of contraction of fast and slow striated muscles can in this way be related to the different patterns of impulse activity which they normally receive.

Animals↗

Control of ACh sensitivity by muscle activity in the rat.

1. Rat soleus and extensor digitorum longus (EDL) muscles were examined following complete blockade of sciatic nerve impulses with anaesthetics or diphtheria toxin for periods up to 14 days.2. Muscles showed atrophy equivalent to that seen after similar periods of denervation.3. Nerve blockade appeared to have little or no effect on neuromuscular transmission when tested by stimulation beyond the block. Normal spontaneous miniature end-plate potentials were present.4. Nerve impulse blockade caused the entire muscle membrane to become sensitive to iontophoretically applied acetylcholine.5. The increase in sensitivity in soleus could be prevented by chronic nerve stimulation distal to the region of block.6. Tenotomy, of 5-12 days duration, which produced atrophy, had no effect on the sensitivity of soleus to acetylcholine.7. Chronic direct stimulation of denervated soleus or EDL muscles could prevent the usual denervation supersensitivity, or cause it to decline towards normal once it had appeared. However, the sensitivity of the end-plate region remained normal.

Acetylcholine↗

The relationship of choline acetyltransferase activity at the neuromuscular junction to changes in muscle mass and function.

1. The role of muscle mass and function in the regulation of choline acetyltransferase activity at the neuromuscular junction has been investigated in the rat.2. Choline acetyltransferase (ChAc) is located in presynaptic nerve terminals and is a specific enzymatic marker of cholinergic innervation in muscle.3. ChAc activity increased co-ordinately with developmental growth of the soleus muscle. However, another form of muscle growth, work hypertrophy, did not produce an increase in ChAc.4. Growth arrest of muscle by hypophysectomy did not alter the normal development of ChAc activity, and cortisone-induced muscle atrophy did not reduce ChAc activity in the soleus or plantaris.5. Tenotomy-induced muscle atrophy provoked a significant fall in ChAc in the soleus and plantaris.6. The tonic soleus had significantly greater ChAc activity than the phasic plantaris.7. These observations suggest that muscle mass per se does not influence the development and regulation of ChAc in muscle but that the quality of muscle contraction may modulate enzyme activity.

Acetyltransferases↗

Enhanced protein synthesis in a cell-free system from hypertrophied skeletal muscle.

Hypertrophy of the rat soleus muscle was induced by tenotomy of the synergistic muscles. Four days after the operation, the weight of the muscle had increased by 30 percent. The hypertrophied muscle had an increased concentration of DNA and RNA, when compared to the contralateral control soleus. Although the amount of myofibrillar protein increased during the 4-day period, the concentration of this component decreased. Microsomes prepared from hypertrophied muscle had an increased RNA concentration. The combined microsomes and pH-5 enzyme from hypertrophied muscle supported a faster rate of protein synthesis in vitro than the same system prepared from an equal weight of contralateral muscle which was used as a control.

Animals↗

Congenital dislocation of the hip: early and late diagnosis and management compared.

During the decade 1970-9, 23 002 infants born in the University of Bristol Department of Obstetrics were examined for congenital dislocation of the hip by junior members of the paediatric staff on the first day of life and again on discharge from hospital. Suspected hip abnormality was checked by a senior member of the staff on the same day. A total of 445 (1.9%) infants were found to have a hip abnormality in the neonatal period. Immediate treatment in an abduction splint was undertaken, usually six weeks for dislocatable hips and 12 weeks for dislocated hips. Routine follow up included clinical and radiological examination at six, 12, 24, and 60 months. Altogether 90% completed the 12 month, 85% the 24 month, and 76% the 60 month checks. Five infants (1.1%) required further orthopaedic treatment (adductor tenotomy and abduction splinting) but no major surgery was necessary, nor was avascular necrosis encountered. The radiological results were excellent. Every effort (1970-84) was also made to identify all cases of late congenital dislocation of the hip diagnosed after the neonatal period in infants born to women in Avon during the same decade (n = 103 431). Ninety one cases were detected (0.88 per 1000 births), 10 in the university cohort (0.44 per 1000) and 81 in the non-university group (1.00 per 1000) (P less than 0.01). Seven of 10 in the former group required open surgery and in seven the radiological outcome at follow up was moderate or poor. The early and late diagnosed groups are compared in respect of perinatal factors and management. It is possible to detect most cases of congenital dislocation of the hip at birth and treat them safely and successfully.

England↗

Decreasing strabismus surgery.

AIM: To determine whether there has been a consistent change across countries and healthcare systems in the frequency of strabismus surgery in children over the past decade. METHODS: Retrospective analysis of data on all strabismus surgery performed in NHS hospitals in England and Wales, on children aged 0-16 years between 1989 and 2000, and between 1994 and 2000 in Ontario (Canada) hospitals. These were compared with published data for Scotland, 1989-2000. RESULTS: Between 1989 and 1999-2000 the number of strabismus procedures performed on children, 0-16 years, in England decreased by 41.2% from 15 083 to 8869. Combined medial rectus recession with lateral rectus resection decreased from 5538 to 3013 (45.6%) in the same period. Bimedial recessions increased from 489 to 762, oblique tenotomies from 43 to 121, and the use of adjustable sutures from 29 to 44, in 2000. In Ontario, operations for squint decreased from 2280 to 1685 (26.1%) among 0-16 year olds between 1994 and 2000. CONCLUSION: The clinical impression of decrease in the frequency of paediatric strabismus surgery is confirmed. In the authors' opinion this cannot be fully explained by a decrease in births or by the method of healthcare funding. Two factors that might have contributed are better conservative strabismus management and increased subspecialisation that has improved the quality of surgery and the need for re-operation. This finding has a significant impact upon surgical services and also on the training of ophthalmologists.

Adolescent↗

Superior oblique tendon expansion in the management of superior oblique dysfunction.

Traditional superior oblique weakening procedures may be unpredictable and lead to superior oblique underaction. The use of 240 retinal band as a spacer to lengthen the superior oblique tendon has been proposed as a more controlled approach than superior oblique tenotomy and related procedures. The use of this technique is reported in a patient with diplopia following an orbital floor blow out fracture, and in a child with Brown's superior oblique tendon sheath syndrome.

Child↗

Achilles tendinopathy: some aspects of basic science and clinical management.

Achilles tendinopathy is prevalent and potentially incapacitating in athletes involved in running sports. It is a degenerative, not an inflammatory, condition. Most patients respond to conservative measures if the condition is recognised early. Surgery usually involves removal of adhesions and degenerated areas and decompression of the tendon by tenotomy or measures that influence the local circulation.

Achilles Tendon↗

Surgical reconstruction of the mitral valve.

From Cutler's first attempt to treat the mitral valve by inserting a tenotomy knife through the left ventricle, to Carpentier's introduction of several repair techniques and a functional classification for assessing mitral valve lesions, the history of mitral valve treatment is exciting. Mitral diseases may be degenerative, ischaemic, infective or rheumatic, with or without superimposed impaired left ventricular function and calcification. Understanding the underlying pathological features is also important in determining whether mitral valve repair is feasible, how the valve should be repaired and the prospect for long-term durability of the repair. Recent advances in minimally invasive mitral valve surgery are promising but more effort is needed to ensure timely mitral valve repair.

Endocarditis, Bacterial↗

Effect of swimming on reinnervation of rat skeletal muscle.

There are no studies that define the optimum intensity or time to begin exercising reinnervating muscle. Through overwork of reinnervating muscle, accomplished by synergistic tenotomy, we developed a working hypothesis. This hypothesis was tested on a physiological model. In the present study, the sciatic nerve of five groups of rats was crushed. One group served as the control and the remaining animals were exercised by swimming with weights attached to their tails for one or two hours each day (early reinnervation group) or four weeks (late reinnervating group) after crush denervation. The evaluation of muscle weights, fibre types, and protein concentration indicate that intense swimming (two hours every day) does not enhance the repair of reinnervation muscle. An evaluation of total proteins suggests that a high workload may be hazardous in the early phase of reinnervation. This study tends to confirm the hypothesis that when there are too few contractile units, as presumably is the case in early reinnervation, exercise inhibits the reinnervation process.

Animals↗