Idiopathic carpal hyperextension in 12 cats (2018-2025)

Area of Science:

• Veterinary Medicine
• Small Animal Surgery
• Orthopedics

Background:

• Idiopathic carpal hyperextension (ICH) is a condition affecting cats.
• Understanding its clinical presentation, radiographic findings, and treatment is crucial for effective management.

Purpose of the Study:

• To characterize the clinical presentation, radiographic findings, and treatment outcomes of idiopathic carpal hyperextension in cats.
• To identify potential breed predispositions and patterns of limb involvement.

Main Methods:

• Retrospective review of medical records from 2018-2025 across multiple institutions.
• Data collection included signalment, clinical signs, diagnostic imaging, treatments, and outcomes for cats diagnosed with ICH.
• Analysis of radiographic findings, including joint angles and hyperextension, on stressed views.

Main Results:

• The study included 12 cats with 20 affected carpi, showing age peaks in young (0-2 years) and older (9-13 years) cats, with Shorthair cats being prevalent.
• All cats presented with carpal hyperextension without significant trauma history; 66% were bilaterally affected, with delayed contralateral limb involvement in some.
• Common signs included palmigrade stance (100%) and thoracic limb lameness (66%). Radiographically, increased antebrachiocarpal angulation was consistent, with metacarpophalangeal and interphalangeal hyperextension in 42% of cases.
• Conservative management (rest, NSAIDs) had good outcomes in 4 cases, while 8 cases had unknown outcomes. Bilateral pancarpal arthrodesis was performed in 4 cats (8 carpi).

Conclusions:

• Idiopathic carpal hyperextension in cats is characterized by a lack of trauma history, frequent bilateral presentation, and a predisposition in Shorthair cats.
• Delayed contralateral limb involvement is possible, necessitating long-term monitoring.
• Treatment strategies range from conservative management to surgical arthrodesis, with variable outcomes.