Supraspinatus Tendinopathy in 327 Dogs: A Retrospective Study

Abstract

Objective: To report clinical findings and treatments for dogs with supraspinatus tendinopathy (ST).Background: ST is a term used to describe tears, calcifying tendinopathy, tendinosis and/or injuries in and around the tendon of the supraspinatus muscle, and is a cause of forelimb lameness, especially in sporting and performance dogs.Evidentiary value: This is a retrospective study of 327 dogs diagnosed with ST.Methods: Medical records (2006 to 2013) were reviewed for history, signalment, prior treatments, physical examination findings, diagnostic imaging and arthroscopic findings, concurrent shoulder and elbow pathologies, and treatments performed.Results: Dogs aged 4 months to 14 years (average 6.5 years; median 6 years) were diagnosed with ST. Performance and sporting dogs were 39.4% of the population, with 58.1% of them being agility dogs. Pain was elicited on palpation of the supraspinatus tendon in 49.3% of dogs. Shoulder radiographs in 283 dogs showed mineralisation in 13% of cases. MRI of the shoulder was performed in 31 cases and revealed findings indicative of ST, including hyperintensity of signal on T1 weighted image (or “spin-lattice”) and Short T1 Inversion Recovery (STIR) sequences of the supraspinatus tendon at its insertion on the greater tubercle and mineralisation of the supraspinatus tendon. Common ultrasonographic findings included increased tendon size (76%), irregular fibre pattern (74%), and non-homogeneous echogenicity (92.5%). The most common findings on shoulder arthroscopy were supraspinatus bulge (82.2%) and subscapularis pathology (62.4%). Elbow pathology was recorded in 54.5% of dogs. Treatment outcomes showed 74.6% of dogs failed to respond to non-steroidal anti-inflammatory drugs (NSAID) and 40.8% failed to respond to rehabilitation. Conclusions: These findings suggest concurrent shoulder and/or elbow pathology is not uncommon in dogs with ST. Further, ST often fails to respond to NSAID therapy and rehabilitation therapy. Application: Other treatments such as regenerative medicine should be considered. Future studies are still needed to assess the use and efficacy of regenerative medicine for ST.

Keywords

• supraspinatus tendinopathy
• shoulder
• musculoskeletal diagnostic ultrasound
• dog