Observations on leg deformity in broilers with particular reference to the intertarsal joint

Abstract

Leg deformities were investigated in two flocks of male broilers. The most frequently encountered lesions were a progressive valgus deformity of the intertarsal joint, dyschondroplasia and an abnormal thickening of growth plates. No chondrodystrophy was observed. In one flock the peak incidence of leg deformities occurred between 3 and 7 weeks of age and 75% of all valgus abnormalities were diagnosed between 22 and 35 days of age (P < 0.001); 62% of broilers with leg abnormality in this flock had growth plate lesions in one or more bones compared to 40% in broilers without deformity (P < 0.001). Although a relationship is indicated between the presence of dyschondroplasia - particularly in the distal tibio-tarsus - and valgus deformity it was considered that dyschondroplasia would increase the likelihood of distortion without necessarily being a pre-requisite for the initial deformity. The terminology of the lesions is discussed.

Clinical and anatomical differences in varus and valgus deformities of chick limbs suggest different aetio‐pathogenesis

“…In Hubbard strain, Cruickshank & Sim (1986) postulate that varus and valgus angulations are symmetrical expression of the same pathology and suggest that deformities could originate from shallow condyle grooves in the distal tibiotarsi. They suggest, in agreement with Randall & Mills (1981), that tendinous displacement observed in varus or valgus angulation is secondary to flattened condyle groove. In the present experiment, condyle groove depth was also reduced in birds affected with varus deformity, but was deeper in birds showing severe valgus angulation.…”

“…In the limb affected by varus angulation, the femur was internally rotated, as described by Duff & Thorp (1985b), and the tibiotarsus had a shallow condyle groove. Similar shallow condyles have been described (Randall & Mills, 1981;Cruickshank & Sim, 1986;Pavaux, 1988). Medial curvature of the metatarsus (Mpa, Mcxa, Table 2) and external axial rotation of tibiotarsus (Duff & Thorp, 1985b;Pavaux et al, 1989; Table 2) were recognized only in limbs with varus angulation.…”

“…Data show numerous contradictory observations concerning symmetry of tarsal joint angulation, occurrence of tendinous displacement or bone deformations. Unilateral (Cruickshank & Sim, 1986) or bilateral deformities (Randall & Mills, 1981;Julian, 1984) have been described as predominant. Displacement of the gastrocnemius tendon has been frequently observed (Sauveur & Mongin, 1976;Harlou & S^rensen, 1984;Cruickshank & Sim, 1986) or rarely according to other observations (Osbaldiston & Wise, 1967;Nairn & Watson, 1972;Julian, 1984).…”

“…Randall & Mills (1981) and Julian (1984) later suggested that the imprecise term of 'twisted legs' should be replaced by valgusvarus angulation. Data show numerous contradictory observations concerning symmetry of tarsal joint angulation, occurrence of tendinous displacement or bone deformations.…”

A syndrome of pathological fractures in the proximal tibiotarsi of white leghorn x new hampshire pullets

“…Necrosis at the apex of dyschondroplastic cartilage in 4-to 5-week-old broiler chickens with tibial dyschondroplasia has been reported (Randall and Mills 1981) but is quite distinct from the lesions in the cases we have described. These lesions were also different from those described in turkey syndrome '65, which is probably associated with mycoplasma infection (Wannop et ah, 1971;Wise and Fuller 1974).…”