There is no superior treatment method for medial shoulder instability in dogs

Excluded:


The evidence
Ten studies were reviewed in this knowledge summary. None were clinical prospective studies, and most had very small case numbers, or were case reports. To date, no prospective randomised trial has been performed to evaluate the effects of medical management of medial shoulder instability (MSI) compared to any surgical technique. Nor, have there been any prospective evaluations comparing the various surgical techniques reported. MSI can encompass damage to only the medial glenohumeral ligament (MGL), only the subscapularis muscle/tendon, or a combination of both as well as the joint capsule. This poses a challenge when evaluating the best options for treatment of MSI as medical management may be most appropriate for one type of instability, while another may require surgical intervention. This plays a role in the evaluation of the ideal

PICO question
In dogs with medial shoulder instability, what treatment option results in the best patient outcomes medical vs. surgical management?

Clinical bottom line Category of research question Treatment
The number and type of study designs reviewed 10 papers were critically reviewed. Whilst one study was prospective in nature, it was performed in research dogs that were then euthanised to evaluate outcome of various surgical procedures. Of the remaining nine papers reviewed, six were retrospective studies, two were case reports, and one was a combination of a cadaveric project with case report Strength of evidence Weak Outcomes reported Surgical and medical treatment of medial shoulder instability can be successful. There is no strong evidence to support one surgical treatment over another Conclusion Dogs diagnosed with medial shoulder instability may be treated successfully with either medical or surgical management

How to apply this evidence in practice
The application of evidence into practice should take into account multiple factors, not limited to: individual clinical expertise, patient's circumstances and owners' values, country, location or clinic where you work, the individual case in front of you, the availability of therapies and resources.
Knowledge Summaries are a resource to help reinforce or inform decision making. They do not override the responsibility or judgement of the practitioner to do what is best for the animal in their care.
surgical treatment as well. Often times, this information is not fully reported and all cases are treated the same; some reports may even include traumatic and congenital luxation with MSI cases for treatment and outcome evaluation. No systematic reviews or meta-analysis have been performed on this topic, for either medical management of MSI, or surgical treatment. There are also no randomised studies evaluating various treatments. Most evidence comprised of single or low number case reports or case studies, with Franklin et al. (2013)

Population: Canine
Sample size: n = 10; eight medial shoulder instability (MSI), one congenital shoulder luxation, and one traumatic induced complete shoulder luxation Intervention details:  All ten dogs in the report underwent surgery via craniomedial approach to the shoulder, incision of subscapularis and arthrotomy  Placement of medial glenohumeral ligament (MGHL) prosthetic suture placed with fishing leader line  Hole drilled just distal to insertion of MGHL and suture anchor placed with fishing leader line; holes drilled at origins of caudal and cranial component of MGHL -some cases had suture anchors placed at both sites, later cases bone tunnels were placed in the scapula replacing the suture anchors  If suture anchors were used two independent loops were tied for the cranial and caudal components  With bone tunnels the suture was placed from the humeral suture anchor, looped through the caudal bone tunnel in the scapula underneath the infraspinatus and supraspinatus against the lateral surface of the scapula and then passed through the cranial bone tunnel and tied  Medial joint capsule was imbricated  Velpeau sling placed 2-4 weeks  MSI: reconstruction 3 times more likely to have successful outcome than medical management (p -0.011) and 1.6 times more likely than RITC (p = 0.44); RITC 1.8 times more likely to be successful than medical management (p = 0.36)  MSI: surgery may be better than medical management, however, many patients did well with no surgical intervention Limitations:  Retrospective study  Not all dogs were re-evaluated, therefore the study may be biased towards those that did not do well  Unblinded re-evaluation of patients  Dogs not randomly assigned to groups, likely bias in what was recommended in the first place Intervention details:  All dogs underwent arthroscopic evaluation and arthroscopic assisted extracapsular stabilisation with a prosthetic ligament  Multifilament braided strand of ultra-high molecular weight long chain polyethylene and polyester double looped through a stainless-steel button and toggle used as prosthetic ligament  Lateral or dorsal arthroscopic evaluation  Guidewire placed from medial aspect of shoulder joint into joint and visualised arthroscopically as placed with goal of placement on glenoid rim at the midpoint of the origin of the medial glenhumeral (MGL) with the lateral exit point in the supraspinatus fossa just cranial to the spine of the scapula and just proximal to the neck of the scapula  Second guidewire placed into the joint from the medial aspect and arthroscopically visualised at the proximal aspect of the humerus; if the MGL was primarily affected the goal was placement at the insertion of the MGL, or if subscapularis tendon (SST) was primarily affected at its insertion point on the humerus, if both were affected it was placed midpoint between the two structures or two separate guidewires were placed, one at each insertion; the angle of insertion was so that the lateral exit point was on the caudodistal aspect of the greater tubercle slightly cranial to the acromial head of the deltoid muscle on the lateral aspect of the humerus   Pre-operative abduction angle median 53˚ (range 50-90˚)  Four cases initially treated arthroscopically; two no improvement, two only slight improvement; subsequently these all underwent SSTOI  SSTOI significantly reduced abduction angle; median 34˚ postoperatively (range 30-35˚) with p = 0.0117  Lameness fully resolved in three cases and greatly improved in two cases  Improvement seen within 2 months of surgery  No recurrence of lameness at mean of 12.6 months postoperatively, (range 6-20 months)  One case that did not do well was later diagnosed with elbow osteoarthritis  One case comfortable on exam, but owners reported intermittent mild lameness following exercise  Group 1 -lateral control, n =3  Group 2 -medial control, n = 3  Group 3 -lateral transfer of biceps tendon, n = 4  Group 4 -medial transfer of biceps tendon, n = 3  Group 5 -medial transfer of supraspinatus insertion (partial), n = 2 (Numbers are written as is stated in the study)

Intervention details:
 Dogs were assigned to 1 of 5 groups listed above; lateral or medial shoulder instability was created  For medial instability, an open approach was used and the tendon of the subscapularis tendon, medial joint capsule, and medial glenohumeral ligament (MGL) were transected  In control dogs, no closure of these structures was performed  For treatment Group 4 the biceps tendon was freed from the intertubercular groove and moved into a groove placed under the lesser tubercle and secured with two small pins  For treatment Group 5 an osteotome was used to cut the proximal half to the greater tubercle with a part of the insertion of the supraspinatus muscle, which was then moved to a medial location on the lesser tubercle and secured with a tension band Study design: Prospective, randomised, terminal study Outcome studied:  Clinical outcome of subjective lameness assessment prior to euthanasia  Development of osteoarthritis was evaluated grossly at necropsy, as well as radiographically, and via histopathology of the articular surfaces and subchondral bone

Main findings: (relevant to PICO question):
 Control dogs walked normally within 2 weeks of surgery, with no joint abnormalities noted on palpation  Group 4, and 5 had prolonged recovery vs. the control  Groups 4 and 5 regained normal limb usage faster than dogs in Group 3 and were usually sound by 4 weeks  No joints had instability at necropsy; all joints had normal range of motion at necropsy  All dogs developed some gross evidence of osteoarthritis (OA) as well as histopathologic evidence of OA; while all dogs developed some degree of OA, comparatively Group 4 reported a higher degree of OA.  Group 4 with medial transfer of the biceps showed stretching of the tendon at necropsy