Laurie's Blogs.

In searching for a topic for today’s blog, I came across a different blog on supraspinatus tendinopathies.  Whenever I see such things, I am always drawn towards check out pubmed to see “What’s New?”  And that what I did here!  So join me in looking at supraspinatus tendinopathies in dogs!

Piras LA, Olimpo M, Lafuente P, Tomba A, Del Magno S, Lardone E, Peirone B, Mancusi D. Surgical Treatment of Nonmineralized Supraspinatus Tendinopathy in Dogs: A Retrospective Long-Term Follow-Up. Animals (Basel). 2023 Feb 8;13(4):592. 

This group reviewed the medical records of 27 dogs diagnosed with non-mineralized supraspinatus tendinopathy that underwent a surgical splitting of the supraspinatus tendon as a treatment technique.  

Outcome:  Resolution of lameness was achieved in 80% of the cases.

MY Thoughts:  Surgery seems like a dramatic treatment for a tendinopathy.  However, if we realize that the splitting is doing nothing more than creating an irritation and stimulating inflammation in order to kickstart healing, then we can be more creative about non-invasive ways to do the same.  Dry Needling…  Shockwave… Photobiomodulation… Targetted therapeutic exercise.

This next group of researchers took a non-invasive approach.

Kern T, Manfredi J, Tomlinson J. Ultrasonographic appearance of supraspinatus and biceps tendinopathy improves in dogs treated with low-intensity extracorporeal shock wave therapy: a retrospective study. Front Vet Sci. 2023 Aug 7;10:1238513. 

This study reviewed the medical records of 30 dogs diagnosed with biceps and/or supraspinatus tendinopathy via musculoskeletal ultrasound, treated using piezowave shockwave, and re-imaged post-treatment.

Treatment: Piezowave-focused shockwave (Piezowave2-VET Richard Wolf—ELvation Medical GmbH) once weekly for three treatment sessions. Treatment was performed within 10 days of initial imaging.

Findings:  26 of 30 dogs had pathology involving both the biceps and supraspinatus tendons in one limb, with 27 of 30 having tendon/s affected bilaterally.

In total, 18 out of 21 of the canine athletes/working dogs (85.7%) were able to return to their sport/work by 3 months following treatment. (2 developed unrelated injuries and one has persistent shoulder pain.)

Eight of the nine pet dogs returned to normal activity (88.9%) by 3 months post-treatment. (One dog had a perpetual unrelated injury.)

There was significant improvement in follow-up musculoskeletal ultrasound evaluation after treatment of their tendons using piezoelectric shockwave therapy.  However, there was no correlation between lameness and ultrasound score at either the PRE or POST timepoint for the tendons involved

MY Thoughts:  This is a nice study that promotes shockwave for treatment of shoulder tendinopathies, however, I am drawn to the part where the ultrasound score did not correlate with lameness.

What do normal supraspinatus tendons look like on Ultrasound?

Lassaigne CC, Boyer C, Sautier L, Taeymans O. Ultrasound of the normal canine supraspinatus tendon: comparison with gross anatomy and histology. Vet Rec. 2020 May 30;186(17):e14. 

Well, this group looked at 19 non-lame cadaver dogs.

Findings:  Close to their insertion on the greater tubercle, all STs displayed a widened portion with a deep central hypoechoic area lacking a fibrillar pattern, when compared with its more proximal aspect and adjacent biceps brachii. Histologically this deep portion corresponded to poorly organized collagen bundles interspersed within a myxoid substance mainly composed of mucopolysaccharides. This central myxoid area with collagen disarray was responsible for the reduced echogenicity on ultrasound.

Conclusion:  In the absence of other ultrasonographic criteria of tendinopathy, a hypoechoic central area in the ST near its insertion should be considered normal.

MY Thoughts:  A thorough physical examination that corroborates US findings would be in order.  OR, perhaps veterinary medicine is actually too quick to jump to imaging for diagnostics and too reliant on those reports when looking for a diagnosis.

What do normal supraspinatus tendons look like on MRI?

Pownder SL, Caserto BG, Hayashi K, Norman ML, Potter HG, Koff MF. Magnetic resonance imaging and histologic features of the supraspinatus tendon in non-lame dogs. Am J Vet Res. 2018 Aug;79(8):836-844. 

This was also a cadaveric study of 7 animals (14 shoulder joints) of 2-year-old non-lame male beagles.

Results indicated histologically normal canine supraspinatus tendons have a trilaminar appearance on MRI images. In dogs, a diagnosis of supraspinatus tendinosis should not be based solely on the tendon having a hyperintense signal on MRI images; other MRI evidence of shoulder joint disease and diagnostic findings are necessary to support such a diagnosis.

MY OVERALL Thoughts as a culmination of these papers:  Perhaps we need to assume that the supraspinatus tendon is in a continual state of overuse and repair.  It would make sense, it’s a prime stabilizer of the shoulder, a prime controller of movement, and often used eccentrically.  So, do we approach it with a bit of ‘ignore that, it’s normal’ or ‘always treat that, because it’s always in and out of a state of tendinosis.  I think you could argue both effectively.  

If the tendon as tender on palpation, then I’d treat it with therapeutic tools (shockwave, laser, dry needling) as well as controlled eccentric exercises (push-ups).  I also believe that these findings highlight the need for ‘tendon conditioning’ in our canine athlete population.

Okay, I hope you have enjoyed this trip down supraspinatus lane!

Until next time…

Cheers!  Laurie