Introduction

Pathology of the biceps tendon (BT) is a common cause of forelimb lameness in active dogs.^1–4 Synovitis of the BT sheath (tenosynovitis) can arise from primary BT pathology or other morbidities such as supraspinatus tendinopathy or the enlargement and encroachment of this muscle into the bicipital groove, resulting in BT impingement.^1,4,5

Published treatments of BT pathology have predominantly focused on transection of the tendon, with or without tenodesis.^6–10 Surgical approach can be via arthrotomy, arthroscopy, or a percutaneous or incisionless approach.^7,8,11,12 Although transecting the BT may improve comfort, it also alters normal anatomy and biomechanics; a transected BT no longer spans the glenohumeral joint, resulting in a loss of the biceps brachii muscle’s role in shoulder extension and stabilization.^1,3,4,8,9,13

Many researchers recommend attempting conservative treatment (CTx) of the BT first, proceeding to surgery only if CTx fails.^1,2,7,14 However, definitions of what constitutes appropriate CTx are absent and the CTx protocols described in some papers and textbook chapters are of questionable adequacy. For example, 1 researcher prescribed oral NSAIDs and exercise restriction for 2 weeks before progressing to surgery.⁷ Other researchers simply advocate a “just cut ’em all” approach, arguing against CTx completely.¹⁵

Historically, specialist treatment of orthopedic injuries, by either conservative or surgical means, has fallen under the domain of board-certified veterinary surgeons (VS). The recognition of board-certified specialty status in sports medicine and rehabilitation (VSMR) has brought a new and potentially different perspective on whether surgery is required to treat biceps pathology and/or what constitutes an appropriate CTx program. Some individuals possess board-certified designation in both surgery and VSMR. Such individuals are referred to as double boarded (DB).

The advent of rehabilitation certification programs (designations CCRT or CCRP) is also new and can be used to determine whether veterinarians possess additional rehabilitation education but not boarded specialty status. Henceforth, board-certified VSMR specialists and nonspecialist veterinarians with CCRT or CCRP certification will herein be referred to collectively as rehabilitation therapists (RTh). Rehabilitation certification programs without the designation CCRT or CCRP are not included within the above RTh designation in the current study.

The purpose of this research was to determine whether there is in fact a difference in therapeutic approaches between VS, RTh, and DB when treating BT disease. This information can be used to determine whether consensus opinion exists on how to best treat this condition. Such consensus agreement can be used to accomplish the secondary goal of this paper, which was to provide a framework on how to best treat various manifestations of BT pathology.

We hypothesized that, compared to RTh, VS would attribute less significance to the BT’s role in providing shoulder stability, be more likely to advocate surgery as a first-line therapeutic approach, and be less optimistic when prognosticating the outcomes of CTx. Furthermore, we hypothesized that there would be significant differences between VS and RTh in the application of a CTx program. Finally, we hypothesized that DB opinions would fall somewhere between those of VS and RTh.

Methods

A survey was developed to test these hypotheses. Ten individuals experienced in the treatment of bicipital tendinopathy (5 VS, 4 RTh, and 1 DB) were asked to provide feedback on a pilot survey. Based on that feedback, the survey was revised, shortened, and made available to a targeted audience. Specifically, it was promoted by each of the American and European Colleges of Veterinary Surgeons and VSMR to members of the Veterinary Orthopedic Society, as well as multiple private listserv and social media groups with specialist VS and VSMR status members, and to groups with rehabilitation certification (listserv@list.vsmr.org, ortholistserv@groups.io, https://www.facebook.com/groups/752787724869613, https://www.facebook.com/groups/976440089198714, https://www.facebook.com/animalrehabdivision, and https://groups.io/g/VetRehab). The survey can be accessed at https://www.surveymonkey.com/r/SVHPSN3.

The survey asked for respondents’ academic credentials, experience treating biceps disease, and their thoughts on whether transecting the BT contributed to either shoulder joint instability or secondary morbidities. Further, respondents were presented with 3 case scenarios that shared a common signalment, that of a “30-kg spayed female 4-year-old field bred Labrador Retriever with whom the owner intends to hike off leash through mountainous terrain for hours at a time, as well as compete in agility with aspirations to make the podium at a national level. There is a 2/5 left forelimb lameness evident at all times, but minimal off-leash running will cause the lameness to become 3/5. It has progressively worsened over the last 6 weeks. In all cases, the owner is highly motivated to receive the best treatment possible and there are no financial or aftercare restrictions.”

Case 1 illustrated a normal BT but moderate impingement from the supraspinatus tendon, resulting in a secondary bicipital tenosynovitis. Cases 2 and 3 illustrated a normal shoulder joint except for tenosynovitis secondary to pathology of the BT, which demonstrated macroscopic tearing affecting 75% (Case 2) and 20% (Case 3) of its cross-sectional surface area.

After 10 weeks, the survey was closed and the collected data submitted for statistical analysis. Eligible respondents were divided into 3 groups (VS, RTh, and DB). VS consisted of board-certified veterinary surgical specialists and surgical residents who had not yet achieved boarded status. Members of this category may or may not also have had CCRT or CCRP certification. RTh included board-certified VSMR specialists, VSMR residents who had not yet achieved boarded status, and veterinarians who had completed CCRT or CCRP programs. Individuals who had completed board-certified designation in both surgery and VSMR were deemed DB. Furthermore, only respondents who had treated a minimum of 6 cases of biceps tendinopathy or tenosynovitis were included.

Results

A total of 223 individuals met the inclusion criteria: 140 VS, 65 RTh, and 18 DB. The survey response rate could not be calculated because the total number of survey recipients was not quantifiable.

Responses to the questions asking whether “transecting the BT increases the chance of secondary shoulder region morbidities or degeneration long-term that will result in clinically relevant gait changes,” or “the BT contributes to shoulder stability in any meaningful way,” are shown (Tables 1 and 2).

For situations in which the biceps tendon is healthy but the patient is experiencing tenosynovitis secondary to supraspinatus impingement, 94.70% of respondents felt that CTx was the best initial therapeutic approach, including 100.00% of RTh, 92.68% of VS, and 84.62% of DB (Tables 3 and 4). RTh felt that the prognostic outcome of CTx was significantly better than that of a surgical approach, but DB and VS both felt that either approach yielded a similar prognostic outcome (Table 5).

For situations in which the majority (75%) of the biceps is torn, 68.30% of respondents felt that surgery was the best initial therapeutic approach. Only 32.76% of RTh felt surgery was the best initial therapeutic approach, compared to 82.64% of the remaining groups choosing surgery (Tables 3 and 4). VS and DB both felt that the surgical prognosis was significantly better than the CTx prognosis, but RTh felt both surgery and CTx had a similar prognostic outcome (Table 5).

For situations in which the minority (20%) of the BT is torn, 85.0% of respondents felt that CTx was the preferred initial therapeutic approach. RTh were unanimous in this assessment, whereas 20.8% of VS and 15.00% of DB still felt that surgery was the better initial therapeutic approach (Tables 3 and 4). RTh felt strongly (P < .0001) that CTx had a better prognosis, but VS felt strongly (P < .0001) that surgery had a better prognosis and DB felt both surgery and CTx yielded a similar prognostic outcome (Table 5).

For all 3 cases, the decision between surgery versus CTx as an initial therapy was not affected by respondents’ experience. However, more experienced respondents were significantly more likely to ascribe a better prognosis for CTx in resolving Cases 1 and 3 when compared to less experienced respondents. This difference did not hold for Case 2. For all 3 cases, less experienced respondents tended to ascribe a better prognosis for surgery when compared to more experienced respondents, but this difference was not statistically significant.

There were significant differences in selection of CTx options (modalities) between groups. Modality selection between groups is listed in descending order of frequency (Table 6). Post hoc analysis determined that, compared to VS, RTh are significantly more likely to employ therapeutic exercise (rehabilitation therapy), extracorporeal shockwave (ESWT), IA platelet-rich plasma (PRP), therapeutic ultrasound, intralesional “stem cell” injections, and pulsed electromagnetic field therapy (PEMF). Compared to both DB and VS, RTh were significantly more likely to employ exercise restriction and photobiomodulation (laser). Compared to VS, RTh were significantly less likely to prescribe NSAIDs and intralesional corticosteroids. Compared to both DB and VS, RTh were significantly less likely to use IA corticosteroids. Although RTh were less likely to select cage rest compared to VS, this difference was not statistically significant.

Intralesional hyaluronic acid and external coaptation were infrequently employed, selected by 2% and 1% of respondents, respectively. Eleven percent of respondents provided text answers under the category of “other,” but the majority did so as a means to elaborate on their treatment regimens (eg, to clarify the number of PRP injections they would employ, that underwater treadmill would be included within their therapeutic exercise program, or that the motive for injecting the biceps tendon with corticosteroids was to induce necrosis). Manual therapy and acupuncture, suggested by a few respondents, were the only additional therapy options that did not already belong to the CTx modalities offered in the survey.

Discussion

Clinical opinion can be affected by a number of factors including confirmation bias, education background, and access or exposure to different treatment options. The adage “if all you own is a hammer, everything looks like a nail,” may well apply here; VS are trained to resolve medical issues through the use of surgery, and RTh are trained in nonsurgical techniques. Rehabilitation certification does not require the same level of experience or education as boarded specialty status. DB status requires the greatest level of education of all the reported groups, yet DB individuals may still have greater experience in one field over another. Given that VSMR specialization was only established in 2010, it may be that most DB individuals were already experienced surgeons with a surgical perspective before earning their boarded VSMR status.

Survey response rate was not calculated as there was no accurate way to determine how many respondents were aware of the survey’s existence, nor could we ascertain how many eligible respondents there were. Even though absolute numbers of boarded surgeons or VSMRs were obtainable, no data exist to determine what percentage of these engage in practice that treats biceps tendinopathy. Many surgeons do not perform orthopedics, focusing instead on soft tissue surgery. Similarly, many RTh work solely in the field of neurologic rehabilitation and do not practice sports medicine.

There is a dearth of research on the effectiveness of various treatments for the multiple manifestations of biceps disease, and it will take considerable time to acquire evidence in the form of meta-analysis of prospective or retrospective clinical therapeutic trials. Until then, in the absence of such information and despite the above noted biases and limitations of clinical impressions, a consensus medical opinion based on the collective experience of qualified individuals from a variety of backgrounds can be the first step in creating a framework on how to best treat BT disease. As new information becomes available, this framework can be modified to reflect such insights.

As hypothesized, compared to RTh, VS attributed less significance to the role of the BT in providing shoulder stability; compared to the other groups, VS were significantly less likely to feel that the BT “always” contributes to shoulder stability and significantly more likely to feel it “never” contributes to shoulder stability.

When asked whether “transecting the BT increases the chance of secondary shoulder region morbidities or degeneration long-term that will result in clinically relevant gait changes,” most respondents answered “don’t know” or “depends” on such factors as body weight or activity level of the dog. The least popular response was “always.” RTh were unanimous in agreeing that “never” was not the correct answer.

In creating the 3 case scenarios, the aim of returning the patient to national-level competition was chosen because the authors felt that successfully achieving this goal would require a more complete resolution of the problem, compared to outcomes in which the patient would only be required to return to a moderate level of exercise. The first case scenario was chosen to determine whether respondents would advocate transecting a healthy BT to palliatively address a primary supraspinatus lesion. Seventy-five percent tearing of the BT (Case 2) was selected to reflect a situation in which the authors suspected most respondents would consider the tendon unsalvageable. Twenty percent tearing of the BT (Case 3) was selected to reflect a situation in which the authors suspected most respondents would consider the tendon salvageable.

As hypothesized, in choosing whether a surgical or CTx approach best addressed the 3 manifestations of bicipital tenosynovitis described in this survey, VS tended toward treating cases surgically and RTh did not. VS also tended to ascribe a worse prognosis for CTx compared to RTh. The opinion of DB individuals fell between these 2 groups.

Despite these differences, there were areas of agreement as well. Specifically, 94.70% of respondents agreed that surgical transection of a healthy BT is an inappropriate first approach in addressing bicipital tenosynovitis secondary to supraspinatus impingement. This answer demonstrated the greatest consensus opinion of the entire survey. One potential reason for this broad consensus was that only 19.30% of respondents felt transecting the BT never contributes to the development of other shoulder comorbidities; for situations in which the supraspinatus is already experiencing tendinopathy secondary to repetitive stress, it could be argued that the loss of the BT’s shoulder stabilizing and extension functions would result in increased demand on the already compromised supraspinatus, thus worsening the pathology.

When 20% of the BT is torn, 85.00% of respondents felt CTx is the best initial therapeutic approach. Conversely, 68.30% of respondents agreed that surgery is the best initial approach in treating a BT that is 75% torn. Presumably, this shift in opinion reflected a belief that a 75% torn tendon is no longer salvageable by CTx means. Respondents were not specifically asked at what point they feel a BT is no longer salvageable, and considerable research will be required to appropriately answer this question. Future research on CTx techniques for biceps repair should quantify the degree of BT fiber disruption pretreatment so that more data can be gathered on this topic.

This survey did not confirm the respondents’ therapeutic goals when attempting CTx: was the goal to reverse the tendon pathology and normalize the joint environment or simply to palliate the symptoms of pain? Such considerations may affect the choice of treatment. For example, 13% of respondents indicated that they would perform intratendinous corticosteroid injections, a technique that has been shown to cause tendon necrosis and subsequent rupture.¹⁶ For those who chose this modality, was the goal to palliate pain? Or, as 1 respondent indicated, was it to induce a complete rupture of the BT? The reliability of performing a bicipital tenotomy via intratendinous corticosteroid injection is unknown. However, it is similar in complexity and instrumentation to the incisionless technique of biceps tendon release, which has shown to provide reliable results in cadavers.¹²

Intra-articular corticosteroid injection has fallen out of favor in human medicine because it is viewed as contraindicated for healing tendinopathy^1,17 and the palliative benefits are both mild and transient.¹⁸ In contrast, seminal veterinary surgical textbooks continue to recommend this therapeutic approach,^19–21 yet VSMR textbooks make no such recommendations.¹ Such differences may underly why 8% of RTh recommended IA corticosteroid injections, compared to 44% of VS. Instead, IA PRP was used by 46% of RTh compared to 25% of VS. The palliative effect of PRP for arthritic pain is well documented,^22,23 but its effectiveness in resolving BT pathology is unproven. Regenerative medicine is discussed as a treatment option for tendinopathy in at least 1 sports medicine textbook¹ but not in surgery texts,^19–21 potentially explaining the difference in popularity of PRP between RTh and surgeons.

We have no studies specifically looking at the use of PRP on the canine BT, but 1 study²⁴ found a 40% response rate when used to treat supraspinatus tendinopathy. Similarly, bone marrow aspirate concentrate coupled with PRP resolved 88% of supraspinatus tendinopathy cases, with the remaining 12% showing incomplete improvement.²⁵

Thirty-three percent of RTh prescribed NSAIDs compared to 58% of VS. Respondents were not asked for how long they would prescribe NSAIDs, so it is unclear whether they intended long- or short-term use. In human medicine, the long-term use of NSAIDs is considered contraindicated when attempting to repair tendon damage, as there is little evidence that they help and there is concern that the vasoconstrictive effect of NSAIDs inhibits the vasodilation required for tendon healing.¹⁷

Therapeutic exercise was the single most recommended CTx modality overall, with RTh significantly more likely to recommend it compared to VS (97% vs 72%). Cage rest was recommended by only 23% of respondents overall, with VS more likely to recommend cage rest compared to RTh (27% vs 11%), but this difference fell shy of statistical significance after post hoc analysis. A positive effect of therapeutic exercise on tendon repair has been shown in human research, as have the deleterious effects of inactivity.^26,27 Although cage rest may be required for patient management in some situations, consideration should instead be given to pharmaceutic interventions such as trazadone and/or gabapentin. Staged return to normal exercise over several weeks, a mainstay of physiotherapy treatment in human medicine, should be employed.

ESWT was the third most popular modality, selected by 57% of respondents. Leeman et al²⁸ concluded that 85% of patients with some combination of biceps and supraspinatus tendinopathy experienced a good or excellent outcome on the basis of owner assessment following a treatment every 3 weeks for 3 treatments. Becker et al²⁹ demonstrated long-term improvement in 64% of dogs following 3 treatments every 3 to 4 weeks, and Kern et al³⁰ demonstrated improved ultrasonic appearance of both the supraspinatus and biceps tendon following ESWT, in addition to improved lameness scores.

More recent meta-analytic research on the use of photobiomodulation for treating tendinopathy shows evidence of effectiveness, in contrast with earlier studies that did not.^31–33 Conversely, therapeutic ultrasound was found to offer no benefit beyond the placebo effect,³⁴ there is inconsistent evidence for the benefits of acupuncture,³⁵ and PEMF has not been clinically evaluated for treating tendinopathy.³⁶ Hyaluronic acid may play a role in the tendon healing process and decrease adhesion formation.^37,38 Manual therapy likely improves patient comfort and possibly mobility, but there is no evidence that it facilitates tendon healing.^39,40

The above information, coupled with the limited canine research available, relevant human research, and what is known about tissue repair, was used to formulate the following recommendations for treating biceps tendinopathy:

• Surgery should not be the primary therapeutic approach when the BT is healthy or if the amount of fiber tearing is ≤ 20%. This recommendation is based on the unanimous consensus opinion of VS, RTh, and DB.

• For situations in which the BT is 75% torn, surgery is likely the best initial therapeutic approach. CTx remains an option, but owners need to be informed of the guarded prognosis. This recommendation is based on the consensus opinion of VS and DB but a dissenting opinion from RTh.

• For cases with tears between 20% and 75%, a case-by-case decision, ensuring best communication about advantages and disadvantages with the owners is likely the best approach. This recommendation is based on the unanimous consensus opinion of VS, RTh, and DB that CTx is the best initial therapeutic response; however, there was disagreement between the 3 groups about whether a surgical prognosis exceeded that of CTx.

• NSAIDs should only be used for short-term pain control and avoided completely when comfort allows; protracted use may delay healing. NSAIDs are not indicated in chronic cases.

• Intra-articular corticosteroids are not an appropriate long-term conservative treatment and are contraindicated when the treatment goal includes tissue repair.

• Intratendinous corticosteroid injections must not be performed. If the end goal is tendon necrosis, a biceps tenotomy should be considered instead, using the least invasive approach available.

• Injections of PRP might be useful, but there is currently a lack of evidence in the published literature when treating biceps tendinopathy in dogs.

• Cage rest is discouraged unless required to enforce compliance with exercise restriction.

• Consider multimodal CTx built on a foundation of therapeutic exercise combined with activity restriction that returns to normal in a staged manner over several months.

• Modalities such as ESWT, regenerative medicine, and photobiomodulation should be considered.

• At this time, there is insufficient evidence to recommend therapeutic ultrasound, PEMF, or acupuncture. Manual therapy may provide increased comfort but does not facilitate tendon repair.

As new information becomes available, appropriate adjustments should be made to the above recommendations. Each of these recommendations would benefit from future clinical research.

Disclosures

The authors have nothing to disclose. No AI-assisted technologies were used in the generation of this manuscript.

Funding

The authors have nothing to disclose.