Biomedical subjects

S R Duff

Publications and source records attributed to S R Duff.

At least 37 records · Page 2Linked to original sources

PubMed1987

Observations on femoral head abnormalities in broilers.

Detachment of the proximal femoral cartilaginous epiphysis was observed in broilers that were being down-graded at slaughter as a result of haemorrhage into thigh musculature. A traumatic aetiology is proposed with injury occurring at catching. Examination of field case material, and birds culled from a commercial flock of the same strain, revealed that physeal lesions are not infrequent in proximal femora. Clefts and areas of matrix necrosis occurred in normal and dyschondroplastic physeal cartilage. Clefts were thought to result from repetitive minor trauma insufficient to cause total detachment of the cartilaginous epiphysis. Total detachment may result from an acute traumatic episode or be a consequence of pre-existing physeal lesions. A traumatic aetiology suggests that in such cases the terms fracture separation or traumatic epiphyseolysis of the cartilaginous epiphysis are more appropriate than femoral head necrosis or degeneration.

Animals↗

PubMed1986

Windswept deformities in poultry.

"Windswept deformities", involving valgus angulation of one intertarsal joint and varus angulation in the contralateral limb, were identified in 75 of 120 turkeys and 24 of 120 broiler fowls which had been culled because of lameness, so that windswept limb angulation was more common in turkeys than broilers. A proportion of cases can be more accurately described as unilateral intertarsal varus deformities with physiological valgus angulation of the contralateral limb. In other cases, marked angulation of one limb probably results from adoption of an altered posture secondary to deformity of the contralateral limb. No correlation was found between abnormal bone torsion, limb angulation and dyschondroplastic lesions. In broilers, almost 70 per cent of windswept limbs with 20 degrees or more intertarsal angulation showed physeal disturbance in the distal tibiotarsus or proximal transometatarsus or both. This finding supports the concept that windswept deformities are commonly associated with physeal lesions but whether the two conditions are causally related is uncertain.

Animals↗

PubMed1986

Rupture of the intercondylar ligament in intertarsal joints of broiler fowls.

On examination of the intertarsal joints of approximately 150 lame broiler fowls, the intercondylar ligament was found to be ruptured, either partially or totally, in 22 birds. In some cases, rupture of the intercondylar ligament occurred in joints with gross angulation and usually in association with collateral ligament instability. In other birds, intercondylar ligament rupture occurred in limbs with minimal angulation but often with concomitant ligament or tendon failure in the same or contralateral limb. A fibrovascular layer was frequently identified between collateral ligaments and their distal tibiotarsal attachment. Haemorrhage in the fibrovascular tissue appears to be responsible for the establishment of the cyst-like structures which were present in some distal tibiotarsi.

Animals↗

PubMed1986

Morphological and radiological findings in induced abnormal bone growth in lambs.

Unilateral hip excision arthroplasty in skeletally immature lambs resulted in altered load bearing and posture in the contralateral limb. Derangement of endochondral bone growth occurred in distal tibiae and metatarsi and both angular and torsional deformities developed. There was no absolute correlation between torsional and angular deformities. Although femoral torsion was variable, the unoperated pelvic limbs frequently developed exaggerated internal torsion of tibiae and metatarsi. Tibiae of operated limbs developed less torsion than was seen in control animals. These findings suggest that functional limb loading can modify developing bone torsion and that torsional deformities in lambs may be a consequence of increased functional torque.

Animals↗

PubMed1986

Histopathology of growth plate changes in induced abnormal bone growth in lambs.

Unilateral hip excision arthroplasty in lambs resulted in osteochondrosis developing in distal tibiae and metatarsi of the contralateral pelvic limb. The physeal cartilage of distal tibiae and metatarsi developed clefts which probably represent shear failure. The histopathology of the meataphyseal defects differed between the medial and lateral growth plate sectors. Medially, the lesions were typical of physeal osteochondrosis in other mammals, with disorganized chondrocyte columns, cell death and matrix necrosis. Laterally, metaphyseal defects were predominantly fibrous, and islands of bone formed in physeal cartilage from re-established endochondral ossification. Both medial and lateral metaphyseal defects were associated with disturbed primary spongiosa formation. It is suggested that, in some instances at least, traumatic physeal clefts, resulting from shear failure in previously normal growth cartilage, may interfere with endochondral ossification and produce osteochondrosis.

Animals↗

PubMed1986

Vascular changes in induced abnormal bone growth in lambs.

In lambs, unilateral hip excision arthroplasty induced angular and torsional deformities in the contralateral limb and the vascular changes associated with abnormal bone growth in distal tibiae and metatarsi have been studied. Eosinophilic septa separating physeal cartilage columns were more frequent and prominent in association with physeal osteochondrosis. Epiphyseal vessels traversed thickened physeal cartilage to an abnormal depth and resulted in protrusions of epiphyseal bone and an irregular epiphyseal bone plate. In some cases, epiphyseal vessels crossed the whole physis and arboresced after turning through 180 degrees. This vascular pattern appears to occur as a reparative response.

Animals↗

PubMed1986

Further studies on knee ligament failure in broiler breeding fowls.

A group of 88, predominantly male, broiler breeding fowls was examined and, in 38, knee ligament failure was identified. All birds were aged between 15 and 60 weeks when examined. Although derangement of the caudal cruciate ligament was the most frequent finding (25 birds), partial or total rupture of the cranial cruciate ligament was also identified (10 birds). Medial (10 birds) and lateral (5 birds) collateral ligament failure was also noted. Knee ligament failure may, in part, be age related. The most frequent concomitant finding in individual birds was tendon or ligament failure elsewhere in the same skeleton. It can therefore be assumed that male broiler breeding fowls are predisposed to ligament and tendon failure and a high proportion will have lesions at more than one skeletal site.

Animals↗

PubMed1986

Embedding of skeletal tissue in plastic for vascular and histological study to demonstrate delayed endochondral ossification in Leghorn type fowl.

A method is described which enables visualisation of the blood supply in developing avian long bones, followed by the preparation of undecalcified histological sections from the same material. The circulatory system was perfused with a solution of fixative, dye and barium sulphate. The skeletal tissue was cleared in plastic resin before embedding and tissue blocks were cut into 1 mm slabs. The vascular canals were then examined with a dissecting microscope. Slabs were re-embedded in resin and 5 microns sections cut for routine undecalcified histological staining. Focal areas of delayed endochondral ossification were demonstrated in slabs prepared from the proximal ends of femora of White Leghorns. These lesions are considered a less severe form of the dyschondroplastic condition occurring in broilers.

Animals↗

PubMed1986

Tendon lesions in broiler fowls.

Tendon lesions have been studied in 35 broiler or broiler breeder fowls. Tendon rupture most commonly affected the gastrocnemius and flexor muscles but was also seen in cranial tibial muscles (four cases) and the patellar tendon (one case). In nine birds tenosynovitis, characterised by a marked inflammatory response, was identified. In others, however, rupture occurred without appreciable inflammation and these cases were concluded to be comparable to spontaneous tendon rupture in other species. A traumatic aetiology is suggested in these cases, as other pelvic limb tendons or ligament rupture was a frequent concomitant finding. Degenerative tendon lesions were present but it is uncertain whether such changes are primary or secondary to rupture.

Animals↗

PubMed1986

Effect of unilateral weight-bearing on pelvic limb development in broiler fowls: morphological and radiological findings.

Twenty-five broiler chickens, which habitually adopted a unilateral weight-bearing stance, were studied. In all cases the contralateral limb was held free of the ground, normally as a result of gross valgus angulation of the intertarsal joint. The left pelvic limb was more frequently weight-bearing than the right which suggests that a pattern of limb dominance may occur in broiler fowls. Metaphyseal lesions, suggestive of dyschondroplasia, were more common in the load-bearing limb. This suggests that altered load-bearing or posture can initiate or exacerbate dyschondroplasia in susceptible birds. The load-bearing limb also showed altered patterns of bone torsion. These findings are similar to those observed in induced physeal (growth plate) osteochondrosis in mammals and the pathogenesis of lesions is likely to be similar.

Animals↗

PubMed1986

Chronic orthopaedic disease in adult male broiler breeding fowls.

An assessment has been made of spontaneous orthopaedic disease in 100 male broiler breeding fowls aged between 51 and 62 weeks. Lesions were identified in the pelvic limbs of 92 birds, 85 of which showed total or partial rupture of ligaments or tendons. Total ligament or tendon failure was identified at one or more skeletal sites in 54 birds. In two cases, avulsion of the femoral origin of the cranial tibial muscle had occurred. Other findings included degenerative changes in a number of joints but there was no correlation with ligament derangement. Partial or total detachment of the femoral head occurred in 16 birds. The primary lesion was disturbed endochondral ossification and, once detached, the femoral head normally became necrotic. In the reparative phase, 'creeping substitution' was identified.

Animals↗

PubMed1986

The gastrocnemius tendon of domestic fowl: histological findings in different strains.

Vascular and histological studies were performed on normal gastrocnemius tendons from male birds considered susceptible (broiler breeding) and insusceptible (laying strain) to noninfectious tendon rupture. Structural differences between strains were noted at the site where rupture usually occurs. This site contains a hypovascular region which develops at an earlier age in broiler type fowls. Histological sections revealed that vessel occlusion had occurred in birds with hypovascular tendon segments. Chondrocytes and chondroid cells adjacent to occluded vessels accumulated lipid and died. This finding was particularly apparent in broiler fowls where cartilaginous plaques were larger and thicker than in laying strain fowls. The presence of occluded vessels, cartilage death and chondroid infiltration of collagen bundles in broiler type fowls are interpreted as structural changes which may predispose to noninfectious tendon rupture. Indeed they may also predispose to tendon lesions associated with pathogens.

Animals↗

PubMed1985

Fractured fibulae in broiler fowls.

Fibular diaphyseal fractures were identified bilaterally or unilaterally in 15 broilers aged between 13 and 105 days. Incomplete cortical defects were also identified on radiographs in a further 8 birds. Fractures and incomplete defects always occurred at the Tuberculum M. iliofibularis of fibulae. The character of bone at this site differed from bone elsewhere in the diaphysis. Following fracture, cartilaginous callus united the diaphyseal segments and pseudarthrosis or fibrous non-union were common sequelae. The concept that fibular fractures in broilers are always a consequence of abnormal proximal tibiotarsal curvature is not supported by this study. It is suggested that differential growth of the paired crural bones is of primary importance.

Aging↗

PubMed1985

Cruciate ligament rupture in young adult broiler knee joints.

Derangement of the caudal cruciate ligament was identified in 11 broiler fowls aged between 18 and 38 weeks. In some cases, the caudal cruciate ligament alone was ruptured, whereas, in others, the caudal meniscofemoral and meniscotibial ligaments and medial meniscus were also deranged. In some birds, ligaments were only partially ruptured but, in 5 cases, complete rupture had occurred in both knee joints. All birds showed severe lameness which, in 2 cases, could only be ascribed to caudal cruciate derangement. Degenerative changes were present in many of the ligaments which suggested that rupture may be a consequence of primary ligamentous change. Proximal tibiotarsal osteochondrosis was a frequent concomitant finding which may affect the integrity of the ligament attachment. A number of other factors including postural abnormality, obesity, and relative inactivity may predispose broilers to caudal cruciate ligament rupture.

Aging↗

PubMed1985

Dyschondroplasia/osteochondrosis of the femoral trochanter in the fowl.

Of 104 lame broilers, 12 birds with femoral trochanteric abnormalities were identified by post-mortem and radiographic examination. Defects occurred in ossification of either the trochanteric zenith or its medial aspect. Lesions were identified as dyschondroplasia, osteochondrosis or osteochondrosis dissecans affecting the articular surface of the femoral trochanter. In the absence of concomitant musculoskeletal disease, degrees of lameness can be attributed to trochanteric lesions. Breaches in the medial trochanteric bone plate permit granulation tissue repair of the articular surface. This repair process, however, did not compensate for the loss of articular surface contour and the junction of reparative and normal tissue may be prone to subsequent degeneration.

Animals↗

PubMed1985

Hip instability in young adult, broiler fowls.

In a study of spontaneous orthopaedic disease in 104 broiler-type birds fed ad lib, 14 cases of hip instability were detected. Female birds were commonly affected and all were aged between 20 and 30 weeks. Although hip luxation was not identified, in most cases the gait abnormality could be attributed to capital femoral ligament failure. There were two main patterns of capital femoral ligament disruption; either the ligament was avulsed, together with a cartilage fragment, from its foveal attachment, or the ligament itself was partially or totally ruptured. Histological evidence suggests that repetitive trauma or acute trauma of sufficient magnitude may be necessary for ligament disruption. It is likely that the excessive weight gain of ad-lib fed birds predisposes to ligament damage.

Animals↗

PubMed1985

Avulsion of muscles from the femoral trochanter in the fowl.

Post-mortem examination revealed lateral femoral trochanteric defects in 14 out of 104 broiler type chickens. All birds were severely lame, and in the absence of concomitant musculoskeletal disease trochanteric lesions were implicated in their clinical signs. Trochanteric muscle insertions had avulsed and the lateral metaphyseal defect was usually lined with granulation tissue. Examination of normal trochanteric development identified endochondral ossification at sites of muscle attachment. In some skeletally immature, proximal femurs evidence of osteochondrosis was detected at sites of trochanteric muscle attachment. It is deduced that broiler femoral trochanters are susceptible to muscle avulsion by virtue of their known predisposition to osteochondrosis and the pattern of muscle insertion.

Animals↗

PubMed1985

Further studies of degenerative hip disease; antitrochanteric degeneration in turkeys and broiler type chickens.

Postmortem examination revealed antitrochanteric degeneration in turkeys (8 male, 2 female) and broiler type chickens (5 male, 1 female). Antitrochanteric degeneration was detected in birds aged 20 weeks or older but histological examination identified lesions in others with grossly normal antitrochanters. Normal and abnormal antitrochanteric development was studied in male, skeletally immature, turkeys and broilers. Differential subchondral bone growth occurred, with relatively delayed ilial bone development. As a result, hyaline cartilage was retained dorsally and persisted even in adult birds. Retained hyaline, and in younger birds growth plate, cartilage was prone to osteochondrosis. When cartilage flap formation involved fissures traversing retained hyaline cartilage, the term osteochondrosis dissecans was appropriate. In other cases of antitrochanteric degeneration, changes typical of osteoarthrosis were present with, in some instances, no evidence of pre-existing osteochondrosis. Certain sites of antitrochanteric cartilage may be susceptible to fatigue failure in these cases.

Animals↗