Outcomes Associated With Treatments for Medial, Lateral, and Multidirectional Shoulder Instability in Dogs

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.

Treatment of Medial Shoulder Joint Instability by Stabilization with an Arthroscopically Guided Prosthetic Ligament: A Cadaveric Feasibility Study in Dogs

OBJECTIVE

 The aim of this study was to assess the feasibility and efficiency of an arthroscopically guided ligamentoplasty of the medial glenohumeral ligament to treat medial shoulder joint instability.

STUDY DESIGN

 Six Beagle cadavers were used (12 limbs). Both arms of the medial glenohumeral ligament were severed using arthroscopic guidance. Arthroscopically guided reconstruction of the ligament was performed. Threaded sutures were fixed with a bone anchor on the medial aspect of the glenoidal cavity of the scapula, passed through a humeral tunnel and finally tensioned with a suture button on lateral aspect of the humerus. Shoulder abduction angles were measured before and after the section of the medial glenohumeral ligament, and following the surgery. Two orthogonal radiographic projections and dissections were performed after each procedure to grade the placement of the implants.

RESULTS

 Surgical repairs were achieved in 10 out of 12 limbs. The abduction angles after repair with ligamentoplasty were not significantly different from the abduction angles measured before the section of the medial glenohumeral ligament.

CONCLUSION

 Arthroscopically guided ligamentoplasty with a scapular bone anchor and a humeral drilling tunnel is feasible in cadavers, and efficient to restore acutely shoulder abduction angle in a minimally invasive manner. Further clinical studies are required to assess in vivo results.

Inverted V-shaped extracapsular stabilisation technique and arthroscopic findings in six dogs with medial shoulder instability

OBJECTIVES

The aim of this case series was to report arthroscopic findings and to evaluate clinical outcomes of dogs treated with an inverted V-shaped extracapsular stabilisation technique without additional external coaptation for medial shoulder instability.

MATERIAL AND METHODS

Medical records of dogs with medial shoulder instability that underwent arthroscopy and an inverted V-shaped extracapsular stabilisation technique were retrospectively reviewed. Extracapsular stabilisation was performed in all dogs using screws and spiked washers as anchor points for the coated polyester prosthetic ligament. No additional external coaptation was used in any dog. A minimum 18-month follow-up period was required for study inclusion. Complications and long-term outcomes were recorded.

RESULTS

The subscapularis tendon and medial glenohumeral ligament were the structures most commonly affected. All dogs had pathological cartilage fibrillations. Implants were successfully placed in all dogs. Implant loosening was recorded in two out of six dogs on recheck but no revision surgery was performed. Function at the time of last clinical follow-up (median, 28 months, range 18 to 33 months) was full in four out of six and acceptable in two out of six dogs.

CLINICAL SIGNIFICANCE

Surgical treatment of medial shoulder instability using the novel inverted V-shaped extracapsular stabilisation technique was successful. Potential complications such as implant loosening may occur. Despite the limited number of cases, the present study suggests that additional postoperative external coaptation may not be necessary for successful management of dogs with medial shoulder instability.

Orthopedic and ultrasonographic examination findings in 128 shoulders of 64 ultra-endurance Alaskan sled dogs

OBJECTIVE

To determine the location and periarticular shoulder-muscle-abnormalities detected via orthopedic examinations and ultrasonography in ultra-endurance Alaskan sled-dogs, returned from an ultra-endurance sled-dog-race prior to finishing it.

STUDY DESIGN

Prospective clinical study.

SAMPLE POPULATION

Sixty-four dogs (128 shoulders).

METHODS

Dogs were classified based on clinical evidence of shoulder pain (SP versus control). Orthopedic examination findings, shoulder-abduction-angles (SAA; before- and during-anesthesia), and ultrasonographic findings were recorded. Relationships between orthopedic and ultrasonographic abnormalities were compared.

RESULTS

Pain was elicited on 55/128 shoulders; 73 shoulders were pain-free. The most common painful structures included the biceps-tendon (BT; 30%), triceps-muscle (28%), and infraspinatus-muscle (25%). SAA ranged between 25° and 75° among groups, including pain-free shoulders in dogs without lameness. SAA was greater when dogs were anesthetized (46.3° ± 14.0° vs. 47.8° ± 12.0°; p = .03), especially in SP (mean increase of 3.49° ± 8.85°) compared to control (0.03° ± 7.71°, p = .009). Overall, 103 ultrasonographic abnormalities were detected (SP: 44; control: 59). The most common ultrasonographic abnormality was fluid surrounding the biceps tendon, similarly distributed between groups (SP: 39/44; control: 57/59). Most chronic ultrasonographic abnormalities affected the BT (15/103 abnormalities). No associations were detected between ultrasonographic abnormalities and clinical findings.

CONCLUSION

Shoulder abduction varied greatly and reached up to 75° in normal joints. Ultrasonographic shoulder-muscle abnormalities were common but did not seem associated with clinical findings.

CLINICAL SIGNIFICANCE

Interpretation of shoulder abduction warrants caution, and the presence of fluid around the BT may reflect a physiologic adaptation to racing, rather than a pathologic change in ultra-endurance Alaskan sled-dogs.

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.

Description and outcome of prosthetic ligament placement for stabilization of medial or dorsomedial tarsometatarsal joint luxation in dogs and cats: 16 cases (2004-2017)

OBJECTIVE

To describe prosthetic ligament placement for reduction and stabilization of medial or dorsomedial tarsometatarsal joint luxation in dogs and cats and to report complications and postoperative outcomes for patients that underwent that procedure.

ANIMALS

14 dogs and 2 cats with medial or dorsomedial tarsometatarsal joint luxation.

PROCEDURES

The electronic database of a referral surgery practice was searched to identify records of dogs and cats with tarsometatarsal joint luxation that underwent prosthetic ligament placement between January 2004 and March 2017. For each study subject, information extracted from the medical record included signalment, a description of the tarsometatarsal joint injury, durations of anesthesia and surgery, and intraoperative and postoperative care and complications. Radiographic images were also reviewed. The long-term outcome for study subjects was assessed by administration of a standardized questionnaire to owners.

RESULTS

Prosthetic ligament placement successfully stabilized the luxated tarsometatarsal joint in all 16 patients. Six patients developed minor postoperative complications, which included bandage-associated dermatitis or ulceration (n = 5) and orthopedic wire failure (1). No major or catastrophic complications were reported. All 13 owners who completed the questionnaire perceived that the described technique resulted in satisfactory long-term function for their pets.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that prosthetic ligament placement was a technically simple procedure that achieved satisfactory long-term stabilization of the tarsometatarsal joint in small animal patients with medial or dorsomedial luxation of the joint. Prosthetic ligament placement may be an alternative to arthrodesis for tarsometatarsal joint stabilization in appropriate patients.

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.

Arthroscopically assisted treatment of injury to the lateral glenohumeral ligament in dogs

OBJECTIVE

To report short and medium term outcomes, and complications, in dogs treated for rupture of the lateral glenohumeral ligament (LGHL) with a novel, arthroscopically assisted technique.

STUDY DESIGN

Retrospective case series.

ANIMALS

Dogs (n = 10) with LGHL injury.

METHODS

Dogs were included after arthroscopic confirmation of rupture of the LGHL and treatment using an arthroscopically assisted suture anchor technique with informed owner consent. Outcomes were assessed by the authors and owners and complications arising from treatment recorded.

RESULTS

After 6 months, 7 dogs were assessed as having full function, 2 as having acceptable function, and 1 had poor function. There was 1 minor intra-operative and 1 minor post-operative complication. There were no major complications encountered 6 months after treatment.

CONCLUSIONS

Dogs with LGHL injury can be treated using this novel technique with low complication rates and good outcomes after 6 months.