19,21,22) Reduction of the central tendon
to the rotator cuff footprint during TOE repair often results in marginal dog ear deformities anterior and posterior to the construct.
Other signs of pneumoperitoneum on supine abdominal film include the doge's cap sign (triangular collection of gas in Morrison's pouch), large area of hyperlucency over the liver shadow, parahepatic air (gas bubble lateral to the right edge of the liver), air outlining the fissure of ligamentum teres and the cupola sign (gas trapped below central tendon
The central tendon
of the diaphragm forms the well-defined superior margin of the cupola sign.
The cause for 'hooding' is attenuation of the central extensor tendon, either from longstanding clawing or from trauma on the dorsal PIP joint and exposure/ necrosis of the central tendon
As pain increases from this process, so does weakness in the tendon and muscle, which then can lead to further development of calcified nodules, tendonosis changes, degenerative partial fiber tears, cyst formation, and central tendon