Long-term outcome after stifle arthroscopy in 82 Western performance horses (2003-2010)

Practical Relevance of Institutional Guidelines in Translational Large Animal Studies of Cartilage Repair-A Multidisciplinary Survey

Background and Objective: Translational large animal models are inevitable to transfer cartilage repair methods into clinical practice. Guidelines for these trials have been published by guiding agencies (FDA, ASTM, EMEA) including recommendations for study descriptors and study outcomes. However, practical adherence to these recommendations is not achieved in all aspects. This study includes an assessment of the recommended aspects regarding practical relevance in large animal models for cartilage repair by professionals in the field. Materials and Methods: In an online based survey, 11 aspects regarding study design and 13 aspects regarding study outcome from previously published guidelines were evaluated (0-10 points, with 10 being most important) by study participants. Additionally, the survey contained questions related to professional experience (years), professional focus (preclinical, clinical, veterinarian, industry) and the preferred translational large animal model for cartilage repair. Results: The total number of survey participants was 37. Rated as most important for study design parameters was lesion size (9.54 pts., SD 0.80) followed by study duration (9.43 pts., SD 1.21); and method of scaffold fixation (9.08 pts., SD 1.30) as well as depth of the lesion (9.03 pts., SD 1.77). The most important aspects of study outcome were considered histology (9.41 pts., SD 0.86) and defect filling (8.97 pts., SD 1.21), while gene expression was judged as the least important (6.11 pts., SD 2.46) outcome. A total of 62.2% of all participants were researchers, 18.9% clinicians, 13.5% veterinarians and 5.4% industry employees. Conclusions: In translational research, recommendations published by guiding agencies receive broad theoretical consensus within the community, including both clinically and preclinically orientated scientists. However, implementation into practical research lacks in major aspects. Ongoing re-evaluation of the guidelines under involvement of all stakeholders and approaches to overcome financial and infrastructural limitations could support the acceptance of the guidance documents and contribute to standardization in the field.

Arthroscopic findings and long-term outcomes in 76 sport horses with meniscal injuries (2008-2018)

OBJECTIVE

To report the findings and long-term outcome of 76 sport horses with meniscal injury.

STUDY DESIGN

Retrospective case series.

ANIMALS

Seventy-six horses with 93 meniscal injuries in 85 stifles.

METHODS

Medical records of sport horses diagnosed with meniscal injury during arthroscopy were reviewed. Owner follow up was obtained via telephone interview ≥1.5 years postoperatively. Preoperative and intraoperative findings, and postoperative treatments, were analyzed for potential association with return to athletic performance.

RESULTS

The medial meniscus was involved in 82.8% of cases, with grade 1 injuries diagnosed in 76.3% of menisci. Overall, 85.5% of horses returned to athletic performance, with 40% returning to their previous level. The grade of meniscal injury was associated with long-term outcome (P = .023). The presence of preoperative radiographic abnormalities (P = .259) or additional joint pathology (P = 1.00) was not associated with long-term outcomes. Fifty-nine stifles were treated with an orthobiologic: autologous conditioned serum, platelet-rich plasma, or marrow-derived mesenchymal stem cells. There was no association between the use of any orthobiologic and long-term outcome (P = .394).

CONCLUSION

This is the first report on long-term outcome of sport horses with meniscal injuries following arthroscopic surgery. Overall, the long-term prognosis was fair, with 40% of horses returning to their previous level of use. Severity of the meniscal injury was a prognostic indicator for return to work. The presence of radiographic abnormalities or additional joint pathology, or the use of orthobiologics, was not associated with long-term outcome.

CLINICAL SIGNIFICANCE

These findings can help in prognostication for sport horses with meniscal injuries.

Regenerative Medicine for Equine Musculoskeletal Diseases

Simple Summary

Lameness due to musculoskeletal disease is the most common diagnosis in equine veterinary practice. Many of these orthopaedic disorders are chronic problems, for which no clinically satisfactory treatment exists. Thus, high hopes are pinned on regenerative medicine, which aims to replace or regenerate cells, tissues, or organs to restore or establish normal function. Some regenerative medicine therapies have already made their way into equine clinical practice mainly to treat tendon injures, tendinopathies, cartilage injuries and degenerative joint disorders with promising but diverse results. This review summarises the current knowledge of commonly used regenerative medicine treatments and critically discusses their use.

Abstract

Musculoskeletal injuries and chronic degenerative diseases commonly affect both athletic and sedentary horses and can entail the end of their athletic careers. The ensuing repair processes frequently do not yield fully functional regeneration of the injured tissues but biomechanically inferior scar or replacement tissue, causing high reinjury rates, degenerative disease progression and chronic morbidity. Regenerative medicine is an emerging, rapidly evolving branch of translational medicine that aims to replace or regenerate cells, tissues, or organs to restore or establish normal function. It includes tissue engineering but also cell-based and cell-free stimulation of endogenous self-repair mechanisms. Some regenerative medicine therapies have made their way into equine clinical practice mainly to treat tendon injures, tendinopathies, cartilage injuries and degenerative joint disorders with promising results. However, the qualitative and quantitative spatiotemporal requirements for specific bioactive factors to trigger tissue regeneration in the injury response are still unknown, and consequently, therapeutic approaches and treatment results are diverse. To exploit the full potential of this burgeoning field of medicine, further research will be required and is ongoing. This review summarises the current knowledge of commonly used regenerative medicine treatments in equine patients and critically discusses their use.

An alternative arthroscopic approach to the caudal pouches of the equine lateral femorotibial joint

BACKGROUND

Current arthroscopic approaches to the caudal pouches of the lateral femorotibial joint are challenging and risk iatrogenic nerve and cartilage injury.

OBJECTIVE

Describe an alternative arthroscopic approach to the caudal pouches of the lateral femorotibial joint in the horse and report intra-articular abnormalities observed during diagnostic stifle arthroscopy of these pouches.

STUDY DESIGN

Descriptive cadaver anatomical and clinical study.

METHODS

An approach to the caudal pouches of the lateral femorotibial joint was developed during clinical surgery using an arthroscopic portal in the popliteal tunnel of the femorotibial joint. Relevant anatomy of the lateral femorotibial joint was reviewed and the arthroscopic landmarks validated on 19 cadaver limbs. The procedure was then incorporated as part of routine inspection of 38 joints in 33 horses.

RESULTS

Entry and examination of both pouches of the caudal lateral femorotibial joint was consistently achieved using an arthroscopic portal immediately cranial to the lateral collateral ligament in both cadaver and clinical limbs, with no adverse effects noted in the latter. Contrary to published descriptions, the division of the pouches was principally formed by a meniscopopliteal septum derived from the joint capsule in all cases, rather than the popliteus muscle and tendon as previously described. Abnormalities were detected in five cases. The finding of bilateral tearing within the popliteus muscle may represent a previously unrecognised arthroscopic condition.

MAIN LIMITATION

Limited case numbers.

CONCLUSION

An arthroscopic portal immediately cranial to the lateral collateral ligament permitted consistent entry into the popliteal tunnel and both pouches of the caudal lateral femorotibial joint.

Subchondral lucencies of the proximal tibia in 17 horses

OBJECTIVE

To describe subchondral lucencies (SCL) in the equine proximal tibia, several treatment options, and clinical outcomes.

STUDY DESIGN

Retrospective study.

ANIMALS

Seventeen horses with proximal tibial SCL.

METHODS

Medical record and radiograph review. Follow-up was obtained via examination and radiography when possible and by telephone and race records when required. The median duration of follow-up was 20 months (range, 0-48).

RESULTS

Proximal tibial SCL were associated with lameness in 14 of 17 horses. Subchondral lucencies were primary in 11 horses and secondary to an ipsilateral medial femoral condyle SCL in six horses. One foal with a primary SCL was euthanized because of osteomyelitis. Six horses ≤1 year old with primary SCL were managed with exercise restrictions only; SCL in three horses without lameness decreased in size, whereas three horses with lameness did not improve. One young horse treated with surgical debridement failed to improve and was euthanized. Lameness resolved in three horses with primary tibial SCL treated with screw fixation. Screw fixation of secondary SCL in five horses led to a reduction in SCL size and degree of lameness.

CONCLUSION

Primary tibial SCL healed with rest in 3 non-lame young horses with small SCL, but was not successful in lame horses with larger SC. Radiographic size and associated lameness improved or resolved with screw fixation in primary and secondary proximal tibial SCL.

CLINICAL SIGNIFICANCE

Primary tibial SCL that did not cause lameness healed with conservative management, but persistent primary and secondary tibial SCL required screw fixation to reduce lameness.