Stabilisation of medial shoulder instability by imbrication of the subscapularis muscle tendon of insertion

OBJECTIVES: To evaluate the efficacy of subscapularis muscle tendon of insertion imbrication as a treatment for medial shoulder instability. METHODS: Medial shoulder instability was diagnosed in five dogs. Initial management with medical or arthroscopic treatment failed to fully resolve lameness in four of the cases. Each case was treated by subscapularis muscle tendon of insertion imbrication. An anatomical model of medial shoulder instability was used to assess the effect of subscapularis muscle tendon of insertion imbrication on the angle of abduction of the shoulder. RESULTS: In clinical study, subscapularis muscle tendon of insertion imbrication was performed in five cases. Lameness resolved fully in three cases and partially in two cases. In cadaver study, transection of either the subscapularis muscle tendon of insertion or the subscapularis muscle tendon of insertion and medial glenohumeral ligament significantly increased the angle of abduction. Imbrication of the subscapularis muscle tendon of insertion significantly reduced the angle of abduction. No significant differences were noted between the angle of abduction of normal shoulder and the shoulder with medial shoulder instability treated by subscapularis muscle tendon of insertion imbrication. CLINICAL SIGNIFICANCE: Subscapularis muscle tendon of insertion imbrication is a moderately effective procedure for the management of medial shoulder instability unresponsive to medical and/or arthroscopic management. The angle of abduction of the shoulder was returned to normal in model of medial shoulder instability, following subscapularis muscle tendon of insertion. Subscapularis muscle tendon of insertion imbrication provides a relatively simple method of treating medial shoulder instability in dogs.     

Rupture of the biceps brachii tendon sheath in two dogs

Rupture of the biceps brachii tendon sheath was diagnosed in two dogs which were presented with chronic thoracic limb lameness. In each case, diagnosis was achieved by positive contrast arthrography, which revealed obvious leakage of contrast agent from the distal portion of the tendon sheath. Arthroscopy was performed in each affected shoulder joint and no other significant lesions were found. In one dog, concomitant bicipital tendinopathy was confirmed by histopathology. Both dogs were treated by bicipital tendon transposition, and tenodesis and both showed improvement in the degree of lameness following surgery. Tearing of the biceps brachii tendon sheath has not been reported previously but should be included in the differential diagnosis for shoulder lameness in the adult dog.     

Supraspinatus tendinosis associated with biceps brachii tendon displacement in a dog

A 4-year-old spayed female Australian Cattle Dog (Blue Heeler) was evaluated because of right forelimb lameness of 5 months' duration. Orthopedic evaluation revealed signs of pain localized to the cranial aspects of both shoulder joints. Via magnetic resonance imaging, the mass of the supraspinatus tendon insertion in both shoulder joints was increased, compared with findings in cadavers of clinically normal dogs; additional imaging procedures revealed that, compared with clinically normal tendons, the tendon had increased signal intensity that was consistent with increased fluid content. The increased supraspinatus tendon mass in each shoulder joint was associated with medial displacement of the biceps brachii tendon, which was more severe in the right limb. Arthroscopic evaluations of both shoulder joints revealed no abnormalities. The dog underwent surgery, and the abnormal parts of the tendons were resected. The most prominent finding on histologic examination of excised tissues was severe myxomatous degeneration. The lameness resolved, and at 22 months after surgery, the dog was reported to have had no recurrence of lameness. The clinical signs and histologic appearance of the tendons in this dog strongly resemble findings associated with tendinosis in humans. Decompression of the biceps brachii tendon may have contributed to the successful outcome after surgery in this dog. Supraspinatus tendinosis should be considered among the differential diagnoses in dogs with uni- or bilateral forelimb lameness.     

Ultrasonography for the diagnosis of diseases of the tendon and tendon sheath of the biceps brachii muscle

OBJECTIVE: To describe the ultrasonographic appearance of the normal and diseased biceps brachii tendon and its tendon sheath in dogs. STUDY DESIGN: A prospective clinical study. ANIMALS: One hundred twenty client-owned dogs. METHODS: In the first part of the study, the ultrasonographic appearance of the normal biceps brachii muscle and the surrounding soft tissue was determined in 27 healthy dogs. Standard views were described and established. In the second part, 120 dogs with suspected pathology of the biceps brachii muscle were examined ultrasonographically. Fifty-five of these dogs had no sonographic changes, and 65 dogs had sonographically detectable pathologic changes of the tendon or the tendon sheath or both. The mean age of the affected dogs was 3.7 years. The ratio of males to females was 1.95:1. Sedation or anesthesia of the dogs was required because of the extreme movements of the leg necessary for the examination. To achieve a perpendicular view of the tendon and the tendon sheath, the area of the shoulder joint was rotated outward and abducted as far as possible. Examination of the muscle-tendon apparatus of the biceps brachii muscle was divided into 4 main sections. RESULTS: Linear transducers (7.5-10 MHz) allowed the soft tissue structures to be easily visualized with ultrasonography. Pathologic changes of the tendon and tendon sheath were visualized sonographically by using high-frequency linear probes. Partial or complete tendon rupture, medial luxation of the tendon, corpora libera in the tendon sheath, and tenosynovitis were clearly shown. CONCLUSIONS: High-frequency ultrasonography using linear transducers allows the examiner to accurately define the pathologic changes in the region of the biceps brachii tendon in dogs. CLINICAL RELEVANCE: The use of sonography for diagnosis of disease processes of the tendon and tendon sheath of the biceps brachii muscle complements clinical and radiographic examination findings.     

Surgical Treatment of Mineralized and Nonmineralized Supraspinatus Tendinopathy in Twenty-four Dogs

Objective— To report and compare the clinical diagnosis, surgical treatment, histopathologic changes, and outcomes of dogs with mineralized and nonmineralized supraspinatus tendinopathy (ST).
Study Design— Case series.
Animals— Dogs (n=24) with ST.
Methods— Medical records (1995–2006) of dogs with ST that had surgical treatment were reviewed. Results of clinical examination, diagnostic imaging, surgery, histopathology of resected tendon tissue, and outcome were compared between dogs with mineralized and nonmineralized ST.
Results— There were 15 dogs with mineralized ST and 9 with nonmineralized ST. Chronic, unilateral, intermittent or waxing-waning lameness, and pain elicited on palpation of the cranial aspect of the shoulder were the most consistent findings. On ultrasonographic or magnetic resonance imaging (MRI) of 35 shoulders, enlargement of the supraspinatus tendon (54%), increased fluid content (63%), and medial displacement of the biceps tendon (60%) were observed. Eleven of 12 dogs with bilateral abnormalities only had unilateral lameness. Surgery was performed in 30 shoulders. Resected tendon specimens had myxomatous degeneration and/or cartilaginous metaplasia in 11 of 13 dogs in the mineralized group and all 9 dogs in the nonmineralized group. Functional outcome after surgery was poor in 3 dogs and good-to-excellent in 16.
Conclusions— Mineralized and nonmineralized ST have many similarities. Although lameness is usually unilateral, the supraspinatus tendon may be affected bilaterally.
Clinical Relevance— Ultrasonography and MRI are good imaging techniques for detection of ST especially the nonmineralized form. Surgical treatment results in good recovery of limb function. Nonmineralized ST is a recently described disorder in dogs and evaluation of more cases is necessary to determine outcome after surgical or medical treatment.     

Bilateral medial displacement of the biceps tendon of origin: repair using polypropylene mesh and staples

A three‐year‐old male greyhound was presented with acute onset right forelimb lameness because of medial displacement of the biceps tendon of origin. Ultrasonographic examination confirmed the diagnosis, and a concomitant partial tear of the medial glenohumeral ligament was detected during arthroscopy. To stabilise the biceps tendon, polypropylene mesh was fixed across the intertubercular groove to replace the torn transverse humeral retinaculum. Recovery was uneventful and lameness resolved. Fifteen months later, the dog was presented with medial displacement of the biceps tendon of origin of the left shoulder, and was treated successfully using the same technique.     

ULTRASONOGRAPHIC EVALUATION OF THE CANINE SHOULDER

The aim of this study was to determine the normal ultrasonographic anatomy of the canine shoulder. Fourteen shoulders from 7 clinically normal mid-sized dogs were radiographed and imaged using high frequency ultrasound. Each shoulder was isolated postmortem, and the ultrasonographic and gross anatomy was studied during dissection. The ultrasonographic appearance of the shoulder specimens was similar to that found in the live dogs. Twenty-four shoulders isolated postmortem from 12 variably sized dogs were also used to characterize the normal ultrasound anatomy over a range of sizes. Important anatomic structures that could be consistently evaluated were the biceps tendon and bursa, the bicipital groove surface, the supraspinatous tendon, the infraspinatous tendon, the teres minor tendon, and the caudal aspect of the humeral head. Results of ultrasonographic examination of 4 dogs with shoulder lameness are described to illustrate some applications of canine shoulder ultrasonography in the evaluation of the canine shoulder. In these dogs, ultrasound was a valuable tool to evaluate effusion and synovial proliferation within the bicipital bursa, supraspinatous and biceps tendinitis, biceps tendon strain, and dystrophic calcification.     

Magnetic Resonance Imaging Findings in Dogs with Confirmed Shoulder Pathology

Objective— To evaluate the diagnostic potential of magnetic resonance imaging (MRI) compared with a reference standard, arthroscopic and/or open surgery, in dogs with soft tissue shoulder pathology. Study Design— Retrospective study. Animals— Dogs (n=21). Methods— Magnetic resonance (MR) images were retrospectively evaluated in 21 dogs that had surgically identified soft tissue shoulder pathology. The musculotendinous units of the biceps, infraspinatus, teres minor, supraspinatus, subscapularis, and the medial and lateral glenohumeral ligaments (MGHL and LGHL) were graded as either normal or abnormal. Abnormal structures were further classified as being either inflamed, partially torn, or fully torn. Impingement of the biceps tendon was also evaluated. Results were reported in terms of agreement and concordance between MRI findings and surgical findings. Agreement was defined as the percentage of times MRI findings concurred with surgical findings with respect to a structure being either normal or abnormal. Concordance was defined as the percentage of times MRI concurred with the exact surgically assessed pathology when abnormality was identified. Results— The findings were biceps tendon: 90% agreement with 100% concordance; subscapularis: 95% agreement with 62% concordance; MGHL: 84% agreement with 83% concordance; LGHL: 88% agreement with 100% concordance; infraspinatus: 100% both agreement and concordance; biceps tendon impingement: 90% agreement with 100% concordance. Conclusions— Soft tissue abnormalities of the canine shoulder were readily identified on preoperative MR images. Clinical Relevance— MRI shows great potential as a diagnostic tool in the evaluation of canine shoulder disease.     

Bicipital tendinitis and tenosynovitis in the dog: a study of 15 cases

AIM: To describe the clinical, radiographic, and sonographic features of 15 dogs with bicipital tendinitis and tenosynovitis, classify them according to cause, and evaluate the long-term efficacy of treatment. METHODS: Dogs exhibiting forelimb lameness with pain localised to the biceps tendon were included in the study. Sonographic examination of the tendon and tendon sheath, and radiographic examination including positive contrast arthrograms of the shoulder joint were performed, and assessed for features consistent with biceps tendon disease. In some cases, synovial-fluid analysis and surgical investigation were also undertaken. The causes of the conditions were classified as either traumatic, mechanical, neoplastic or inflammatory. Dogs were treated conservatively with rest and anti-inflammatory drugs, or surgically by either transection of the transverse humeral ligament or tenodesis of the biceps tendon. Assessment of the effects of treatment was made by re-examination at six weeks and from information gained by telephone interview with the dog's owner at longer-term follow-up. RESULTS: Bicipital tendinitis and tenosynovitis were common causes of forelimb lameness in active, middle-aged or older, medium to large-breed dogs. The most sensitive physical tests for localising pain to the biceps apparatus were shoulder flexion with the elbow extended, focal digital pressure applied directly to the biceps origin, and the biceps retraction test. Sonographic assessment was found to be more sensitive than shoulder radiography or arthrography for characterising the lesion. Conservative treatment of 11 traumatic cases resulted in good or excellent function at long-term follow-up. One mechanical bicipital tendinitis secondary to mineral deposits within the supraspinatus tendon improved following transection of the transverse humeral ligament and removal of the deposits. One of two cases of inflammatory tendinitis/ tenosynovitis improved following tenodesis. One dog with neoplastic disease did not improve and was euthanased. CONCLUSIONS: The diagnosis of bicipital tendinitis and tenosynovitis requires a careful examination using a combination of physical tests. Of the ancillary tests, sonography was the most reliable, however information gained from all tests was useful in fully evaluating the biceps apparatus and shoulder joint. The classification system employed in this study was helpful in selecting a treatment protocol and determining the likely prognosis.     

Computed tomographic arthrography is a useful adjunct to survey computed tomography and arthroscopic evaluation of the canine shoulder joint

The aim of this retrospective, methods comparison study was to assess the diagnostic utility of computed tomographic arthrography in the assessment of various intraarticular shoulder pathologies in dogs in comparison with survey computed tomography (CT), using arthroscopic examination as the reference standard. Computed tomography, computed tomographic arthrography, and arthroscopic findings of 46 scapulohumeral joints of dogs with forelimb lameness were reviewed retrospectively. Predefined sites were assessed for the presence or absence of disease. If a lesion was present, a prespecified pathology was designated. Computed tomographic arthrography was found to be a safe technique which provided a superior diagnostic efficacy relative to survey CT for the assessment of the biceps tendon and biceps tendon sheath (sensitivity 71%, specificity 75%, positive likelihood ratio 2.9, negative likelihood ratio 0.38) and humeral head cartilage (sensitivity 65%, specificity 97%, positive likelihood ratio 19, negative likelihood ratio 0.37). Computed tomography and computed tomographic arthrography provided additional diagnostic information to arthroscopy in regard to osteophytosis, subchondral defects, and joint mice. Computed tomographic arthrography alone was of limited diagnostic value for assessment of the medial and lateral glenohumeral ligaments (sensitivity 13% and 0%, specificity 1% and 78%, positive likelihood ratios unmeasurable and 0, negative likelihood ratios 0.88 and 1.29, respectively) and the subscapularis tendon (sensitivity 14%, specificity 98%, positive likelihood ratio 5.7, negative likelihood ratio 0.88). Computed tomographic arthrography is therefore a useful adjunct to survey CT and arthroscopic evaluation of the canine shoulder joint, however, is not a replacement for these techniques.     

Role of the tendons of the biceps brachii and infraspinatus muscles and the medial glenohumeral ligament in the maintenance of passive shoulder joint stability in dogs

OBJECTIVE: To objectively evaluate the effect of transecting the tendon of the biceps brachii muscle (BBT), tendon of the infraspinatus muscle (IFS), or medial glenohumeral ligament (MGHL) on shoulder joint stability in canine cadavers. SAMPLE POPULATION: 81 forelimbs from mature dogs. PROCEDURE: Cadaver forelimbs were placed in a testing frame and axially preloaded with 4 kg of weight. Shoulder joint stability was tested in neutral joint position, flexion, and extension before and after transection of the BBT (n = 37), IFS (37), or MGHL (7). Humeral translation relative to the glenoid was induced by applying a 3-kg load in each of 3 directions (cranial, lateral, and medial) and quantitatively measured by use of an electromagnetic motion tracking system. Peak translational data were compared in each joint position before and after transection of the BBT, IFS, or MGHL. RESULTS: When tested in neutral position, the cranial, lateral, and medial translation of the humerus was significantly increased after BBT transection. In the flexed position, translation of the humerus in the cranial and lateral directions was significantly increased after BBT transection. In the extended position, the medial translation of the humerus was significantly increased after BBT transection. Complete medial luxation of all humeral heads occurred following transection of the MGHL. CONCLUSIONS AND CLINICAL RELEVANCE: The BBT contributes to passive shoulder joint stability in dogs, particularly in the neutral and flexed positions. It also provides medial stability during shoulder joint extension. Complete luxation of the joint occurs when the MGHL is transected.     

Results of a survey of small-animal practitioners on the perceived clinical efficacy and safety of an oral nutraceutical

A mail survey of 3080 practitioners from two sampling frames was used to determine the perceived clinical efficacy and safety of an oral nutraceutical for the treatment of degenerative joint disease (DJD) in small animals. Overall response rate was 82%, of which 64% reported that they were recommending the oral nutraceutical to their clients. There was a high variability reported between the severity of DJD and response to treatment. Sixty-eight percent of practitioners reported lame dogs older than five years to be the most responsive to treatment. Most practitioners (83%) believed response to treatment with the studied product occurred within four weeks. Practitioners using the product rated the clinical efficacy of the product to be either 'good' or 'excellent' in improving mobility, alleviating pain and improving attitude in the majority of the treated animals. No practitioner reported a worsening of pain, mobility or attitude. Self-reported adverse effects were 2% (the most common was gastrointestinal upset). The results of this survey indicated that perceived clinical efficacy of the studied nutraceutical in the treatment of DJD was regarded to be 'good' or 'excellent' by most of the practitioners who use this product and was considered to be safe with minimal side effects. This provides additional information on the product for use in planning future clinical trials.     

BICIPITAL TENOSYNOVITIS IN THE DOG—EVALUATION WITH POSITIVE CONTRAST ARTHROGRAPHY

This paper describes seven dogs with traumatic bicipital tenosynovitis in which complete clinical, radiographic, and surgical evaluations were performed. All were adult dogs of medium to large breed and were presented with a chronic front limb lameness of several months' duration and shoulder muscle atrophy. Survey radiographs of the scapulohumeral joint showed new bone production almost exclusively in the region of the biceps tendon, i.e., the intertubercular groove and the supraglenoid tuberosity. Arthrograms in six of seven dogs revealed difficulty in filling or irregular filling of the bicipital tendon sheath, best seen on the mediolateral view of the shoulder. On surgical exploration, macroscopic lesions of the tendon and/or the sheath were observed in all dogs and included adhesions, fibrosis, scar tissue, edema, and thickening. Partial tear of the tendon was observed in three dogs.     

Use of T-plates for the stabilisation of supra-cotyloid ilial fractures in 18 cats and five dogs.

The use of the AO (Arbeitgemeinschaft für Osteosynthesenfragen) veterinary T-plates (1.5/2 mm and 2.7/3.5 mm) for stabilisation of supracotyloid ilial fractures in 18 cats and five dogs was evaluated in a retrospective study. The distal fragment from the coxofemoral joint ranged from 0.5 cm to 1 cm with a mean distance of 0.85 cm. Twenty out of 23 (87%) ilial fractures healed in original alignment. Three out of 23 (13%) animals had two loosened screws of the distal fragment with fracture malunion and minor medial displacement of the acetabular fragment. Screw or plate breakage was not observed and the implants were not removed. The clinical result was 'excellent' for 18 animals (78%), 'good' for four animals (17%), and 'poor' for one animal (5%). The use of T-plates permits good correction of supracotylo?d fractures with minimal approach and minimizes post-operative complications.     

Transposition of the biceps tendon to reduce lateral scapulohumeral luxation in three species of nondomestic ruminant.

Open reduction of lateral luxation of the scapulohumeral joint was performed in a Mhorr gazelle (Gazella dama mhorr), a southern pudu (Pudu puda), and an Alpine ibex (Capra ibex ibex) by transposition of the biceps brachii tendon lateral to the greater tubercle of the humerus. The ibex had a very large greater tubercle that required a second osteotomy to allow successful lateral transfer of the tendon. Although all three animals were non-weight bearing in the first 2-3 wk after surgery, ambulation improved at 3 wk and was almost normal by 6 wk after surgery. Postoperative follow-up of 8 yr, 7 mo, and 3 mo in the gazelle, pudu, and ibex, respectively, revealed normal ambulation with no gait deficits. The gazelle was euthanized 8 yr after surgery for unrelated disease and necropsy demonstrated mild to moderate degenerative joint disease. Similar lateral shoulder luxations in comparably sized, nondomestic ruminants, without concurrent fractures or significant joint abnormality, have a good prognosis for return to function after surgical reduction using a biceps tendon transposition.     

Treatment of dogs diagnosed with medial shoulder instability using radiofrequency-induced thermal capsulorrhaphy

OBJECTIVE: To report clinical findings and outcome in dogs diagnosed with medial shoulder instability (MSI) treated with radiofrequency-induced thermal capsulorrhaphy (RITC). STUDY DESIGN: Retrospective study. ANIMALS: Dogs (n=43) with MSI. METHODS: Medical records from consecutive cases with MSI based on orthopedic examination, palpation of shoulder abduction angles, and arthroscopic findings were used to determine clinical findings and long-term (> or = 1 year) outcome of RITC. RESULTS: Forty-three dogs met the criteria for inclusion; 2 dogs had bilateral MSI. The most common clinical findings were chronic unilateral weight-bearing lameness, large (> 45 degrees) shoulder abduction angles, and spinatus muscle atrophy in the affected limb. Mean preoperative abduction angle (50.7 degrees +/- 4.8 degrees) in affected shoulders was significantly larger than in the unaffected shoulders (32.5 degrees +/- 2.1 degrees). Mean postoperative abduction angle in affected shoulders was not significantly different from unaffected shoulders when measured immediately, 8, 16-20 weeks, and approximately 1 year after surgery. Follow-up evaluation ranged from 1 to 6.2 years. RITC treatment resulted in improved clinical function in 40 cases (93%) with 34 cases (79%) considered excellent; 3 cases (7%) were considered failures. CONCLUSIONS: RITC was a safe and effective method of treatment of MSI in most dogs studied. CLINICAL RELEVANCE: RITC can be considered as a viable option for surgical treatment of selected cases of MSI in dogs.     

Pre- and postoperative radiographic and computed tomographic evaluation of dogs with medial patellar luxation

OBJECTIVE: To quantify, using radiographic and computed tomographic (CT) techniques, the effects of surgical procedures most commonly combined to treat dogs with medial patellar luxation (MPL). STUDY DESIGN: Prospective study. METHODS: Six dogs with 8 MPL were studied. Radiographs and CT of the pelvic limbs were obtained before and immediately after soft-tissue reconstruction, trochlear wedge recession, and tibial crest transposition. Radiographic measurements included angle of inclination, Norberg angle, quadriceps angle (QA), anteversion angle, ratio of the length of the patellar tendon (PT) to the length of the patella, and change in patella tendon angle. CT measurements included angle of inclination, Norberg angle, QA, anteversion angle, depth of the femoral trochlear groove, ratio of the middle femoral trochlear groove depth to the patella thickness, and tibial crest alignment. RESULTS: Conformation of the coxofemoral joint was not affected by surgery. Surgical treatment corrected the QA by 33-58%. Trochlear wedge recession was most effective in deepening the proximal trochlea by 103.5%. The ratio of the middle femoral trochlear groove depth to the thickness of the patella postoperatively resulted in 50% coverage of the patella. Tibial crest transposition resulted in caudalization of the PT by 8.5+/-3.0 degrees, with lateralization of the tibial tuberosity of 11.3 degrees. CONCLUSION: The effects of surgery for MPL can be quantified with radiographic and CT measurements. Surgical correction restored the alignment of the quadriceps and adequately deepened the femoral trochlear groove. Tibial crest transposition resulted in caudalization of the patella tendon and lateralization of the tibial tuberosity. CLINICAL RELEVANCE: These pilot data quantified the effects of surgical procedures most commonly combined to treat MPL. We hope to use these measurements to correlate surgical treatment with functional outcome and postoperative occurrence of luxation.     

Unusual soft tissue orthopaedic problems in the dog

Single cases of supraspinatus and infraspinatus muscle contracture in working sheep-dogs are reported. Both cases showed characteristic abnormal forelimb posture and were successfully treated by complete section of the affected muscle. Three cases of anteromedial shoulder luxation with damage to the biceps brachii tendon are also described. In two of these the tendon was completely severed. The integrity of the biceps tendon is important in maintaining shoulder joint stability and should be inspected when surgical reduction of shoulder dislocations is carried out. Repair of the tendon, if severed, is important. Three cases of lameness associated with tendon displacement are considered i.e. slipping of the biceps brachii, long digital extensor and superficial digital flexor tendons. In two cases the displacement was prevented by the insertion of mattress wire sutures to form a 'lid' over the tendon.     

Pilot study of the ultrasonographic examination of the intact and transected medial glenohumeral ligament in dogs

Medial glenohumeral ligament injury is commonly reported during medial shoulder joint instability in dogs. Arthroscopy is considered the gold standard procedure, but it is invasive and requires distension of the joint. Ultrasonographic examination of the medial glenohumeral ligament has been studied as a possible, less invasive alternative to arthroscopy however it has not been considered a useful method of assessment due to the interference of the probe with the pectoral muscles. The aims of this prospective analytical randomized pilot study were to develop a standardized ultrasound protocol for visualizing the canine medial glenohumeral ligament and to compare goniometry and ultrasound findings in cadaver dogs with versus without transection of the medial glenohumeral ligament. Nine adult Beagle cadavers (18 shoulders) were used. The first six shoulders were used in a preliminary study to describe an ultrasound technique to identify the medial glenohumeral ligament. Arthroscopy was performed on the remaining 12 shoulders, with six randomly selected medial glenohumeral ligaments from these shoulders, transected during the procedure. Ultrasound examination was performed after each arthroscopic procedure by an ultrasonographer blinded to the patient group. Four medial glenohumeral ligaments (67%) were correctly identified during the preliminary study. Ultrasonographic examination failed to diagnose the transection of all six medial glenohumeral ligaments in the second part of the study. No difference was observed in the ligament thickness between the dogs with and without a transected medial glenohumeral ligament. Dogs with a transected medial glenohumeral ligament had a wider articular space compared to dogs without a transected ligament (P < 0.001), and an articular space wider than 8.2 mm was discriminatory of a transected medial glenohumeral ligament in all the shoulders. In conclusion, the medial glenohumeral ligament could be identified with a medial ultrasonographic approach of the shoulder and a wider articular space can be a sign of a medial shoulder joint instability. Further studies are needed to confirm these preliminary findings in living dogs, with and without shoulder instability.