The canine shoulder: selected disorders and their management with physical therapy

Ultrasonographic appearance of supraspinatus and biceps tendinopathy improves in dogs treated with low-intensity extracorporeal shock wave therapy: a retrospective study

Objective

This study aimed to determine whether dogs with shoulder tendinopathy diagnosed via musculoskeletal ultrasound would show improvement in imaging after treatment using piezoelectric shockwave therapy and rest.

Methods

Medical records were reviewed for dogs diagnosed with biceps and/or supraspinatus tendinopathy via musculoskeletal ultrasound, treated using piezowave shockwave, and re-imaged post-treatment. Data collected included patient signalment, duration and grade of lameness, prior rest, piezowave dose, and patient outcome, including a return to sport where applicable. Images were scored using an adapted ultrasound grading scale, in addition to obtaining cross-sectional area measurements. Statistics included Shapiro-Wilk tests (normality), Wilcoxon matched pairs signed rank tests (pre- vs. post-treatment comparisons), and Spearman's correlation coefficients (lameness grade vs. ultrasound score) (significant at P < 0.05).

Results

In total, 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. For both tendons, post-treatment cross-sectional area and ultrasound score were significantly lower than pre-treatment (P < 0.001). Lameness decreased clinically (P < 0.0001) following piezowave shockwave treatment regardless of the tendons involved, but the lameness score did not correlate with the ultrasound score for either tendon.

Conclusion

Dogs with tendinopathy of the biceps brachii and supraspinatus showed significant improvement on follow-up musculoskeletal ultrasound and lameness evaluation after the treatment of their tendons using piezoelectric shockwave therapy with rest.

Clinical significance

Canine biceps brachii and supraspinatus tendinopathy can cause variable lameness and ultrasonographic appearance, which improves after shockwave therapy and rest. The ultrasound scoring system and cross-sectional area assessment provide useful outcome measures for clinical cases.

Management of Injuries in Agility Dogs

Agility is a physically demanding sport, and injuries are common. An understanding of the common clinical presentations, frequent injuries, and risk factors for injury is critical when seeing this population of patients in practice. Shoulder injuries and other soft tissue injuries including iliopsoas muscle strains are commonly seen. The Border Collie seems to be at higher risk of developing agility-related injuries. The key to rehabilitation of the agility dog is accurate and expedient diagnosis of the injury, which often involves advanced diagnostics such as musculoskeletal ultrasound, arthroscopy, and/or MRI.

Surgical Treatment of Nonmineralized Supraspinatus Tendinopathy in Dogs: A Retrospective Long-Term Follow-Up

(1) Background: two forms of supraspinatus tendinopathy (ST) have been reported in dogs: mineralized and non-mineralized. Surgical treatment consists of longitudinal incisions (splitting) in the tendon of insertion of the supraspinatus muscle. The purpose of this retrospective study is to describe the diagnostic workout, the surgical procedure and the short and long term follow up of dogs treated for non-mineralized ST. (2) Methods: medical records (2010-2017) of dogs diagnosed with non-mineralized ST that underwent surgical treatment were reviewed. Data retrieved were: signalment, history, clinical signs, orthopaedic examination findings, diagnostic imaging findings, surgical treatment, histopathologic diagnosis and clinical outcome. (3) Results: A total of 27 dogs met the inclusion criteria. The most consistent clinical findings were intermittent lameness accompanied by pain on palpation of the insertion of the supraspinatus. Magnetic resonance imaging (MRI) of 27 shoulders distended sheaths of the biceps tendon (10/27), compression of the biceps brachii tendon sheaths (5/27) and enlargement of the supraspinatus tendon (3/27) were observed. The most prominent histologic finding was severe myxomatous degeneration in all 27 samples. Resolution of lameness was achieved in 80% of the cases surgically treated without any further lameness episodes in the long-term follow-up. (4) Conclusions: the surgical splitting of the non-mineralized supraspinatus tendon is an effective procedure with no intra-operative complications and a low incidence of minor (18%) and major (4%) complications.

Efficacy of Serial Ultrasonographic Examinations in Predicting Return to Play in Agility Dogs with Shoulder Lameness

The aim of this study is to investigate the use of shoulder ultrasound as a method of predicting the likelihood of returning to competition in agility dogs with shoulder teno-muscular injuries after a standardised rehabilitation protocol. Thirty-two agility dogs with a clinical and ultrasonographic diagnosis of shoulder teno-muscular injury were included in a prospective study with physical and ultrasound examinations at the time of diagnosis (T0) and at two (T2), four (T4) and six (T6) months; during this period, the dogs received rehabilitation treatments. The endpoint of the study was to obtain information regarding participation in agility competitions 12 months after diagnosis, based on telephone interviews with the owners. The clinical lameness score (CLS) and the ultrasound lesion score (ULS) were used as outcome measurements. The CLS indicated partial recovery from a shoulder injury at T2 (78%), while the ULS indicated no satisfactory recovery at T2 in any patient. At 4 months, the CLS alone was not a valuable predictor of full recovery from a shoulder injury in agility dogs. Relative Risk indicated that, at T2, ultrasound was 23.8 times more valuable in identifying a shoulder lesion as compared to clinical lameness score (CLS), and it was 2.53 times more valuable at T4.

Associations between early neutering, obesity, outdoor access, trauma and feline degenerative joint disease

OBJECTIVES

The aim of this case-control study was to identify early-life risk factors associated with the occurrence of owner-reported mobility changes in 6-year-old cats by examining prospective data from a longitudinal cohort study of pet cats, the Bristol Cats study.

METHODS

Data on potential risk factors were obtained from seven sequential questionnaires completed between the ages of 2-4 months and 5 years. Mobility-related questions from the study questionnaire distributed at the age of 6 years were used to calculate each cat's mobility score. Cats with mobility scores of ⩾2 and 0 were allocated to the case and control groups, respectively, and the cat's status was the outcome variable.

RESULTS

Of the 799 cats included for analysis, 238 (29.8%) had owner-reported mobility changes. Binomial logistic regression using backwards elimination identified four risk factors for owner-reported mobility changes at 6 years of age: entire neuter status at 6 months of age (odds ratio [OR] 1.97; 95% confidence interval [CI] 1.26-3.07), sustained trauma before 6 years of age (OR 1.85; 95% CI 1.30-2.60), outdoor access at 6 years of age (OR 1.67; 95% CI 0.96-2.90) and overweight/obese status at 6 years of age (OR 1.62; 95% CI 1.13-2.33).

CONCLUSIONS AND RELEVANCE

Risk factor analysis demonstrated that obesity, outdoor access and a history of trauma may predispose cats to developing owner-reported mobility changes associated with degenerative joint disease, whereas neutering before 6 months of age appears to decrease that risk.

The Shoulder Joint and Common Abnormalities

The shoulder is a complex joint composed mostly of static and dynamic capsuloligamentous structures and plays an important role in forelimb lameness. Its complex anatomy and biomechanics necessitate thorough examination and diagnostic work-up for accurate diagnosis. This article provides an updated review of common canine shoulder pathologies, including osteochondrosis, bicipital and supraspinatus tendinopathies, infraspinatus contracture, medial shoulder syndrome, and luxation.

A Modification of the Cheli Craniolateral Approach for Minimally Invasive Treatment of Osteochondritis Dissecans of the Shoulder in Dogs: Description of the Technique and Outcome in 164 Cases

OBJECTIVE

 The aim of this study was to describe a novel minimally invasive surgical approach for the treatment of shoulder osteochondritis dissecans (OCD) in dogs and to retrospectively review our clinical cases treated with this approach.

STUDY DESIGN

 The study describes a modification of Cheli surgical approach (1985), developed to reduce the degree of invasiveness as well as the incidence of postoperative complications observed in other surgical approaches to the shoulder joint. Medical records of dogs that underwent our minimally invasive approach to the scapulohumeral joint for treatment of OCD from May 2001 to May 2019 were retrospectively reviewed for intraoperative findings and complications. Clinical outcome and complications were also evaluated in the operated dogs with a minimum of a 2-month-follow-up evaluation.

RESULTS

 A total of 164 shoulders in 141 dogs (23 bilateral), 103 males and 38 females, were examined and treated with our modified craniolateral approach for the treatment of OCD of the humeral head. In all cases, the modified craniolateral approach allowed visibility and adequate exposure of the caudal humeral head surface. Radiographic and clinical follow-up evaluations were available in 123/164 (75%) cases. The clinical outcome was consistent with other reports using different surgical approaches for OCD lesions of the humeral head in dogs.

CLINICAL SIGNIFICANCE

 This technique provided a reliable approach for surgical treatment of canine shoulder OCD and can be considered a valid alternative to other surgical approaches including arthroscopy.

Effect of antioxidants, mitochondrial cofactors and omega-3 fatty acids on telomere length and kinematic joint mobility in young and old shepherd dogs - A randomized, blinded and placebo-controlled study

In dogs, decreasing telomere length is a biomarker for cellular aging. On a systemic level, aging affects the locomotor system in particular, leading to restricted joint mobility. As aging is thought to be related to oxidative stress, it may be counteracted by a diet enriched with antioxidants, mitochondrial cofactors and omega-3 fatty acids. This randomized, blinded and placebo-controlled study examined the influence of an accordingly enriched diet compared to a control diet on 36 young and 38 old shepherd dogs. At the outset, after 3 and after 6 months, mean and minimum telomere lengths were measured. Furthermore, minimum and maximum joint angles and range of motion of the shoulder, elbow, carpal, hip, stifle and tarsal joints were measured by computer-assisted gait analysis. A positive influence of the enriched diet on old dogs could be verified for minimum telomere length and all three parameters of the shoulder joint on the side with the higher vertical ground reaction force after 6 months. In the other joints there were less significant differences; in some cases they indicated a contrary influence of the enriched diet on young dogs, probably due to its reduced protein content. The greater effect of the enriched diet on minimum than on mean telomere length may be due to the higher preference of telomerase for short telomeres. The greater effect on shoulder joint mobility is explained by the greater influence of musculature and connective tissue in this joint. For elderly dogs it is advisable to feed these nutritional supplements.

Feasibility and safety of arthroscopic medial glenohumeral ligament and subscapularis tendon repair with knotless anchors: A cadaveric study in dogs

OBJECTIVE

To test the feasibility and safety of an arthroscopic imbrication of the medial glenohumeral ligament (MGHL) and the subscapularis tendon with knotless anchors in dogs.

STUDY DESIGN

Cadaveric study.

SAMPLE POPULATION

Ten limbs.

METHODS

Cranial and caudal arms of the MGHL were imbricated with a 2.9- or a 2.4-mm knotless anchor. A horizontal mattress suture secured with a 3.5-mm knotless anchor was used to imbricate the subscapularis tendon. Computed tomography measurements included (1) the bone stock around the anchors, (2) the angle between the anchor and the joint surface (insertion angle), and (3) the angle formed by lines tangent to the cortices of the bones (safety angle). Limbs were dissected to assess the position of anchors. Safety and insertion angles and bone stock were compared among anchors with a Kruskal-Wallis test (P < .05).

RESULTS

Surgical repairs were achieved in all limbs, with only 2 of 30 anchors incorrectly placed, both in the glenoid. The safety angle of the humeral anchor (HA; median, 89°) was greater than that of the cranial glenoid anchor (CrGA; P = .0017) and the caudal glenoid anchor (CdGA; P < .001). The insertion angle of the HA (median, 68°) was also greater than that of the other anchors (P < .001 and P = .001). The insertion angle of the CrGA (median, 26°) was greater (P = .0191) than that of the CdGA (median, 7°). All anchors were inserted at the MGHL and subscapularis footprint.

CONCLUSION

Arthroscopic imbrication of MGHL and subscapularis tendon was feasible. HA were safer to place than glenoid anchors.

CLINICAL SIGNIFICANCE

The results of this feasibility study justify further evaluation of the indications and outcomes of this technique in dogs with shoulder instability.

Ultrasonographic findings of shoulder teno-muscular structures in symptomatic and asymptomatic dogs

PURPOSE

B-mode sonographic evaluation of shoulder joint in dogs provides qualitative information concerning mainly tendon and muscles structures. Although the sonographic findings of tenomuscular lesions have been described previously, their frequency in symptomatic and asymptomatic patients has not been reported yet. Aim of the study was to describe and compare qualitative ultrasonographic findings of shoulder joint in clinically symptomatic and asymptomatic dogs and to speculate which lesions might be considered major responsible for lameness.

METHODS

Fifty-two dogs with shoulder lameness and 58 asymptomatic dogs (both with unremarkable radiographic findings) underwent ultrasonographic B-mode examination of the scapulohumeral joint. Lesions detected were recorded and statistically compared between groups.

RESULTS

Significant differences between groups were observed for the number of ultrasonographic abnormalities detected and for fluid accumulation, biceps brachii tendon (BT) lesions and bone surface irregularities. Sonography was considered useful for the determination of lesions absence and for the detection of BT lesions, fluid accumulation, muscle lacerations and bone surface irregularities. The odds for symptomatic dogs were greater than for asymptomatic patients to ultrasonographically diagnose BT lesions, fluid accumulation and bone surface irregularities.

CONCLUSIONS

Ultrasound has proven to be a useful tool in the evaluation of tenomusculoskeletal structures of shoulder in dogs with unremarkable radiographic findings. Our results suggest that ultrasonography is useful in the diagnosis of tendon abnormalities, fluid accumulation, muscle lacerations and bone surface irregularities as potential contributors to shoulder lameness in dogs.

The magnitude of muscular activation of four canine forelimb muscles in dogs performing two agility-specific tasks

Background

The purpose of this study was to measure the muscular activation in four forelimb muscles while dogs performed agility tasks (i.e., jumping and A-frame) and to provide insight into potential relationships between level of muscular activation and risk of injury. Muscle activation in eight healthy, client-owned agility dogs was measured using ultrasound-guided fine-wire electromyography of four specific forelimb muscles: Biceps Brachii, Supraspinatus, Infraspinatus, and Triceps Brachii – Long Head, while dogs performed a two jump sequence and while dogs ascended and descended an A-frame obstacle at two different competition heights.

Results

The peak muscle activations during these agility tasks were between 1.7 and 10.6 fold greater than walking. Jumping required higher levels of muscle activation compared to ascending and descending an A-frame, for all muscles of interest. There was no significant difference in muscle activation between the two A-frame heights.

Conclusions

Compared to walking, all of the muscles were activated at high levels during the agility tasks and our findings indicate that jumping is an especially demanding activity for dogs in agility. This information is broadly relevant to understanding the pathophysiology of forelimb injuries related to canine athletic activity.

Orthoses and exoprostheses for companion animals

Exoprostheses are devices that are secured to incomplete limbs to enable locomotion. By comparison, orthoses are devices externally applied to support or protect an injured body part. Orthoses also can be used to control, guide, protect, limit motion of, or immobilize an extremity, a joint, or a body segment. Exoprostheses and orthoses are a growing aspect of the physical rehabilitation of companion animals. They require precise design and fabrication. Patients and owners must be trained to use the devices. Exoprostheses and orthoses can have a profound beneficial impact on the mobility and the quality of life of companion animals.

A validated approach for collecting fine-wire electromyographic recordings in four canine shoulder muscles during highly dynamic tasks

This study investigated the feasibility of obtaining ultrasound-guided intramuscular fine-wire electromyographic (fEMG) recordings from four canine shoulder muscles during highly dynamic activities. Four cadaveric canines were utilised to confirm the appropriate anatomical landmarks and the use of real time ultrasound guidance for electrode placement for four shoulder muscles: Biceps Brachii (BB), Supraspinatus (SP), Infraspinatus (IF), and Triceps Brachii – Long Head (TBLH). Electromyographic activity of the left BB, S P, IF, and TBLH was then recorded in two research dogs while walking and trotting to refine the data collection procedures. Finally, the full experimental protocol was piloted with two client-owned, specially-trained agility dogs, confirming the feasibility of collecting fEMG recordings while performing dynamic, highly-specific agility-related tasks and verifying our EMG amplitude normalisation protocol to enable comparisons across muscles and performance tasks. We present specific guidelines regarding the placement of fEMG electrodes and data collection/normalisation procedures to enable investigations of muscle activation during dynamic activities.

Principles and application of range of motion and stretching in companion animals

Optimal function after injury, surgery, or in patients with chronic conditions requires adequate motion in joints, muscles, tendon, fascia, and skin. Range of motion and stretching exercises are commonly used in companion animal rehabilitation programs to maintain or improve motion of musculoskeletal tissues. Range of motion exercises and stretching prevent adhesions from forming, help scar tissue remodeling, may improve muscle tone, and prevent future injury from occurring. Stretching is used to avoid loss of motion or to regain lost joint motion. Stretching is done manually, using external coaptation, or using therapeutic exercises. Careful documentation of range of motion is necessary.

Is the long sarcomere length responsible for non-traumatic supraspinatus tendinopathy? Potential novel pathophysiology and implications for physiotherapy

Several theories have been proposed to explain the mechanism of non-traumatic supraspinatus tendinopathy, which causes rotator cuff tendinitis and rotator cuff ruptures. However, these theories have not addressed all potential causes of rotator cuff tendinopathy. We propose that the microanatomy of the supraspinatus muscle and its response to gravity is the mechanism that responsible for non-traumatic supraspinatus tendinopathy and rotator cuff tears. Gravity causes chronic traction to the supraspinatus muscle, which results in elongation in the sarcomere length. Elongated sarcomere length causes compression on the micro vessels in the muscle which compromises internal microcirculation of the muscle and tendon. Poor microcirculation triggers ischemia and ischemia triggers inflammation process in the muscle and the tendon. This results in a higher incidence of tendinopathy. We also propose a new physiotherapeutic approach that may provide improved healing for rotator cuff tendinopathy.

Animal models for translational research on shoulder pathologies: from bench to bedside

Several animal models have been used for in vivo and in vitro shoulder research. In vitro models, consisting of cadaveric specimens, are useful in providing basic understanding of the functioning of the shoulder and for biomechanical experiments. In vivo models provide the means to model living phenomena, such as tendon healing process, tendinopathy, instability, and adaptive responses to surgery. However, intrinsic differences among different species make translation to human shoulder pathologies difficult. Most of the animals used in experimental settings are quadrupeds, using the forelimbs for weight-bearing during locomotion, with no or minimal overhead activity. The various animal models already used to study shoulder pathologies are presented in this article. However, there is a lack of validation for these animal models, which provides challenge to the further research in this field.

Preclinical models for translating regenerative medicine therapies for rotator cuff repair

Despite improvements in the understanding of rotator cuff pathology and advances in surgical treatment options, repairs of chronic rotator cuff tears often re-tear or fail to heal after surgery. Hence, there is a critical need for new regenerative repair strategies that provide effective mechanical reinforcement of rotator cuff repair as well as stimulate and enhance the patient's intrinsic healing potential. This article will discuss and identify appropriate models for translating regenerative medicine therapies for rotator cuff repair. Animal models are an essential part of the research and development pathway; however, no one animal model reproduces all of the features of the human injury condition. The rat shoulder is considered the most appropriate model to investigate the initial safety, mechanism, and efficacy of biologic treatments aimed to enhance tendon-to-bone repair. Whereas large animal models are considered more appropriate to investigate the surgical methods, safety and efficacy of the mechanical-or combination biologic/mechanical-strategies are ultimately needed for treating human patients. The human cadaver shoulder model, performed using standard-of-care repair techniques, is considered the best for establishing the surgical techniques and mechanical efficacy of various repair strategies at time zero. While preclinical models provide a critical aspect of the translational pathway for engineered tissues, controlled clinical trials and postmarketing surveillance are also needed to define the efficacy, proper indications, and the method of application for each new regenerative medicine strategy.