Metacarpophalangeal Flexural Deformity in a Calf: Surgical Approach

Abstract

Background: Flexural deformity is a condition often caused by the contracture of the superficial digital flexor tendon (SDFT) and/or deep digital flexor tendon (DDFT), which can affect the carpal, metacarpophalangeal, and distal interphalangeal joints, significantly interfering with locomotion and normal development in affected calves. Several factors are associated with this condition, which can be classified as mild, moderate, or severe. Diagnosis is made through clinical and radiographic examination. Treatment may vary between conservative and surgical approaches, depending on the severity of the deformity. Calves with severe deformities may not respond to treatment and often require euthanasia. This article aims to report the surgical treatment of bilateral metacarpophalangeal flexural deformity in a calf.

Case: A 9-day-old male mixed-breed calf was admitted to the Large Animal Sector of the Veterinary Teaching Hospital at Paranaense University (UNIPAR) in Umuarama, Paraná, Brazil, presenting bilateral flexural deformity in the thoracic limbs. Clinical examination revealed non-reducible bilateral hyperflexion of the metacarpophalangeal joint, with dorsal weight-bearing sores. Radiographic examination confirmed metacarpophalangeal hyperflexion with no underlying bone abnormalities, leading to a diagnosis of flexural deformity. The initial therapeutic approach involved tenotomy of the superficial and deep digital flexor tendons. Additionally, the interosseous muscle tendon, distal ligaments of the accessory digits (II and V), flexor tendons of digits III and IV, and the flexor manica were transected. Metacarpophalangeal arthrotomy was also performed. Robert Jones bandages were applied to both limbs to protect and support the joints, preventing cranial displacement and metacarpophalangeal flexion immediately after cast removal. After seven days, the immobilization and sutures were removed, with significant improvement in the metacarpophalangeal joint angle.

Discussion: Flexural deformity is a common orthopedic condition in cattle and horses, particularly in young animals, characterized by the inability to fully extend limb joints due to shortening or contraction of flexor tendons, suspensory apparatus, ligaments, or joint capsules. The etiology is variable, including prenatal and postnatal factors, genetic predisposition, intrauterine conditions (e.g., space restriction), and nutritional imbalances. In severe cases, surgical treatment is recommended, and the removal of all anatomical restrictions is crucial. If tenotomy alone does not restore full extension, arthrotomy may be necessary. In this case, arthrotomy combined with synthetic cast immobilization and a Robert Jones bandage ensured limb extension, contributing to a positive outcome. Despite its invasiveness, this technique should be considered even in early-stage cases, as chronicity may lead to irreversible dorsal limb lesions due to abnormal weight-bearing, which can compromise the skin, tendons, joint capsule, and articulation. Novel surgical approaches are crucial for challenging cases where conventional methods fail. Here, arthrotomy with distal limb immobilization effectively resolved severe congenital flexural deformity, ensuring full recovery. The success of this case suggests early surgical intervention with anatomical release may prevent degenerative changes and improve long-term outcomes.

Keywords: arthrotomy, tenotomy, locomotion, cattle, SDFT, DDFT, tendons.