VCS 806_Shoulder-2023.pdf

SHOULDER DISEASES IN SMALL ANIMALS SUN YOUNG KIM PURDUE UNIVERSITY [email protected] Outline  Shoulder anatomy  Shoulder dislocation/instability  Osteochondrosis dissecans (OCD)  Common muscle/tendon conditions  Biceps tenosynovitis  Supraspinatus tendon disease  Infraspinatus contractur...

SHOULDER DISEASES IN SMALL ANIMALS SUN YOUNG KIM PURDUE UNIVERSITY [email protected] Outline  Shoulder anatomy  Shoulder dislocation/instability  Osteochondrosis dissecans (OCD)  Common muscle/tendon conditions  Biceps tenosynovitis  Supraspinatus tendon disease  Infraspinatus contracture  Signalment / Etiology  Physical examination findings  Diagnostics  Treatment options  Prognosis Learning Objectives List abnormal physical examination findings Construct diagnostic plan Interpret radiographs of shoulder List common shoulder conditions based on signalment and orthopedic examination Recognize surgical indications of shoulder conditions Anatomy – Lateral Deep Layer Biceps tendon Lateral Glenohumeral ligament Image:Vet surgery Teres Minor Image:Vet Anatomy The dog & Cat Stabilizers of the shoulder Passive: Congruity of the joint (concavity), Glenohumeral ligaments, Joint capsule Active: supra/infrasptinatus, subscapularis, teres minor mm. Other muscles around shoulder Supraspinatus Subscapularis Biceps Transverse humeral retinaculum Image:Vet surgery Image:Vet Anatomy The dog & Cat SHOULDER LUXATION / INSTABILITY Not Common Congenital/Chronic Small Breeds Acute trauma Any animal Medial Instability Athletic dogs Shoulder Luxation - Diagnosis  History  Chronic (congenital) Vs. Acute (trauma)  Orthopedic examination  Often non-weight bearing  Anatomical landmarks  Instability, crepitus  +/- pain Shoulder Luxation - Diagnosis  Orthogonal radiographs  Confirm direction  Evaluate severity / abnormality  Rule out other problems  CT  Evaluate abnormality Shoulder Luxation Treatment – Conservative  Closed reduction/conservative Spica splint Velpeau sling management  Acute luxation without other problem  Closed reduction under general anesthesia  Stable after reduction  Bandage (2-4 weeks)  Medial luxation → Velpeau sling  Lateral luxation → Spica splint  Activity restriction for 4 weeks Images: handbook of small animal ortho and fracture repair Shoulder Luxation Treatment - Surgical  Reconstruct Passive stabilizers  Glenohumeral ligament → Prosthetic ligament  Joint capsule → Imbrication  Biceps transposition  Support humeral head  Postoperative care (6 weeks)  Bandage (2 weeks)  Medial luxation → Velpeau sling  Lateral luxation → Spica splint  Activity restriction for another 4 weeks Medial Shoulder Instability  Athletic dogs  Proposed causes of instability  Disruption of medial stabilizers  Joint capsule, glenohumeral lig., subscapularis m.  Signalment/History  Middle-aged medium ~ large breeds  Chronic lameness (various severity)  Minimal response to NSAID Medial Shoulder instability - Diagnosis  History of chronic lameness  Orthopedic examination  Pain on hyperextension  Increased shoulder abduction  Under sedation  Poor reproducibility/repeatability → Compare with the contralateral side Jones VOS 2017 Case Images: Courtesy Dr. von Pfeil Medial Shoulder instability - Diagnosis  Radiographs/CT  Not specific  Normal ~ DJD  Rule out other conditions  Arthroscopy  Cartilage damage in humeral head  Erosion of the medial ridge of glenoid  Tearing of the medial glenohumeral ligament  Synovitis (not specific) Rochat: “..notable MGHL/Subscap damage w/o lameness, … clinically normal dog” Medial Shoulder instability - Treatment  Conservative  Surgical stabilization  Exercise restriction  Prosthetic glenohumeral ligament  Shoulder hobbles (6-9 weeks)  Open approach  Rehabilitation  Fluoroscopy assisted  Stem cell, PRP injection??  Arthroscopy assisted  Subscapularis imbrication  For a dog with mild lameness  Biceps transposition  ~ 85% success (no study) Case Images: Courtesy Dr. von Pfeil Shoulder Luxation / Medial Instability – Salvage Procedures  Indications  No proper function but just pain  Severe osteoarthritis  Abnormal structure  Failed surgical stabilization  Arthrodesis  Glenoid excision → Good prognosis with Mild mechanical lameness OSTEOCHONDROSIS DISSECANS (OCD) OCD - Etiology / Signalment  Failed endochondral ossification  Large ~ Giant breed dogs  Male > Female  Immature or young dogs  OC develops while grwoing  Often bilateral (27 ~ 67%)  Caudal aspect of the humeral head  Can have elbow dysplasia OCD – Orthopedic Exam / Diagnostics  Weight bearing lameness  Pain on extension of an affected shoulder  Shoulder extension → tense the caudal aspect of the joint OCD – Orthopedic Exam / Diagnostics  Weight bearing lameness  Pain on extension of an affected shoulder  Shoulder extension → tense the caudal aspect of the joint  Bilateral Orthogonal Radiographs  Mediolateral view OCD - Treatment Cartilage flap Joint mouse  Conservative management  Only for asymptomatic / mild condition  Rest / NSAID  Reparative surgery → Good prognosis Calcified cartilage  Removal of cartilage flap and joint mice  Debride calcified cartilage  Expose subchondral bone  Stimulate hemorrhage → Fibrocartilage formation over 2-3 months strict activity restriction for 2-3 months Cartilage flap is removed Debrided calcified cartilage Hemorrhage from subchondral bone OCD - Treatment  Conservative management  Only for asymptomatic / mild condition  Rest / NSAID  Reparative surgery → Good prognosis  Removal of cartilage flap and joint mice  Debride calcified cartilage  Expose subchondral bone  Stimulate hemorrhage → Fibrocartilage formation over 2-3 months strict activity restriction for 2-3 months OCD - Treatment  Restorative surgery  Osteochondral Autogenous Transfer Suregery (OATS) Fitzpatrick. Vet Surg 2010  Favorable outcome  Donor site morbidity  Synthetic osteochondral resurfacing  Favorable outcome  Complications related to surgical sites Murphy.Vet Surg 2019 Soft tissue injury - Muscle, Tendon  Hunting dogs, Working dogs  Biceps brachialis tendinopathy  Supraspinatus tendon calcification  Infraspinatus muscle contracture Image/Video: Drs. Dejardin, Hayashi, Kapatkin, Dagner Biceps Brachialis Tendinopathy (Biceps tenosynovitis)  Middle age, large, athletic dogs  May occur due to strain from trauma/overuse  May be secondary to shoulder instability?  Mild inflammation ~ Disruption of tendon and dystrophic calcification  History  Chronic Intermittent to progressive weight-bearing lameness  Worse lameness after exercise Biceps tenosynovitis - Examination  Orthopedic examination  Positive biceps test  Diagnostics  Radiographs (3 views)  Shoulder Flexion  Arthrography  Elbow extension  Joint fluid analysis  Direct pressure over the tendon insertion  Ultrasonography  CT, MRI  Arthroscopy  Surgical exploration Image: handbook of small animal ortho and fracture repair Biceps tenosynovitis - Diagnostics  Radiography  Mediolateral & Skyline view  Ultrasonography  Fluid accumulation within the bursa and around the tendon  Changes to the tendon structure Scapula Humerus Normal tendon Courtesy: Dr. Degner Biceps tenosynovitis – Treatment / Diagnostics  Conservative  Exercise restriction (2-3 months) !!  NSAID  Intra-articular Steroid → will lead DJD  Prednisolone acetate 10 – 40 mg  Triamcinolone 5 mg  Rehabilitation  Platelet enriched plasma (PRP) ??? Normal Biceps tenosynovitis Biceps tenosynovitis – Treatment  Surgical treatment  Structural changes of the tendon (tear, irritating calcification)  Poor response to conservative management Biceps release Image: Courtesy Dr. Dejardin Tenodesis Calcification of Supraspinatus Tendon  Middle aged larger breeds Biceps  Incidental or clinical  R/O with biceps tenosynovitis  History of chronic subtle lameness  Ortho exam Supraspinatus  Often unremarkable  Can mimic biceps tenosynovitis Cranial view of the shoulder Calcification of Supraspinatus Tendon - Diagnostics  Radiographs  Orthogonal + Skyline view  CT or MR  Ultrasonography Supraspinatus Biceps Calcification of Supraspinatus Tendon – Treatment / Prognosis  Conservative  Activity restriction  NSAID  Platelet Rich Plasma (PRP)?? Injection  Surgical excision  Poor response to conservative management  Postoperative care  Carpal flexion bandage ( < 2 weeks)  Activity restriction for 2-4 weeks → Good prognosis Images: handbook of small animal ortho and fracture repair Infraspinatus Muscle Contracture  Hunting dogs, Working dogs  Unknown etiology  Trauma, Progressive fibrosis  History  Acute/chronic lameness  Orthopedic examination  Muscle atrophy (shoulder)  No pain/gait alteration  Abduction of extremity with external rotation Case Image: Courtesy Dr. Dejardin Infraspinatus Muscle Contracture  Diagnosis PreOp PostOp  History + physical examination  Treatment  Surgical excision and release  Excellent prognosis Case videos: Courtesy Dr. Dejardin Summary – Shoulder Conditions Miniature ~ Small Breeds Growing Large ~ Giant Mature ~ Old Growing • Congenital luxation • Chronic instability • OCD • Traumatic luxation • Chronic luxation • Traumatic luxation Mature ~ Old • Tendon disease • Biceps tenosynovitis • DJD • Supraspinatus • Traumatic luxation • Infraspinatus • Medial instability • Traumatic Luxation • DJD/OA