Arthroscopic surgery for the treatment of osteochondrosis in the equine shoulder joint

Needle Arthroscopy of the Scapulohumeral Joint and Bicipital BURSA in Horses: An Ex Vivo Study

To evaluate the feasibility of performing needle arthroscopy of the scapulohumeral joint and bicipital bursa in standing horses by using the thoracic limbs of euthanized horses. To that purpose, this experimental study was designed. Ten thoracic limbs, five left and five right from euthanized horses were retained in an upright position to simulate a standing horse. The craniolateral and lateral scapulohumeral arthroscopic portals were used to access the articular structures. A third (caudal) portal was also identified and described. The degree of difficulty in accessing the articular space and the optic maneuverability within the joint were compared between portals. The needle arthroscopy image lacks in quality, but the procedure was considered useful as a diagnostic aid for examination of the scapulohumeral joint of horses. Needle arthroscopy of the bicipital bursa was not possible. Needle arthroscopy has a great diagnostic potential for lesions in the scapulohumeral joint of horses. A new access (caudal) to the scapulohumeral joint of horses has been identified.

Diagnostic needle arthroscopy of the scapulohumeral joint in standing sedated horses

OBJECTIVE

To describe the technique to perform diagnostic standing scapulohumeral joint needle arthroscopy with a 1.2-mm-diameter arthroscope in horses.

STUDY DESIGN

Experimental study.

ANIMALS

Eight thoracic limbs in phase 1 and six horses in phase 2.

METHODS

In phase 1, the feasibility of the technique was evaluated by using a craniolateral arthroscopic approach. An evaluation of the visible structures of the scapulohumeral joint was performed with both a needle arthroscope and a 4-mm-diameter arthroscope. In phase 2, the technique was performed in six healthy sedated horses to validate the technique in live animals and to report any complications or limitations.

RESULTS

In phase 1, joint evaluation was similar between arthroscopes and allowed complete evaluation of approximately the lateral half of the humeral head and the lateral glenoid rim. In phase 2, all joints were successfully accessed, and fluid extravasation was mild. Arthroscopic visualization was complete for the centrolateral aspect of the joint in all horses and either complete (3/6) or partial (3/6) for the craniolateral and caudolateral structures, respectively. The procedure was rapidly performed and well tolerated, and no postoperative complications occurred.

CONCLUSION

The described technique was simple and allowed direct inspection of the scapulohumeral joint. Nonetheless, the standing nature of the technique prevents evaluation of the medial aspect of the humeral head and most of the glenoid cavity.

CLINICAL SIGNIFICANCE

Needle arthroscopy of the scapulohumeral joint is feasible in horses and offers a diagnostic technique that may improve the surgeon's diagnostic ability for certain shoulder pathologies.

Arthroscopic approaches to and anatomy of the shoulder joint of cattle: a cadaver study

Background

Arthroscopic surgery is described as a minimally invasive technique for diagnosis, exploration and treatment of joint disorders. It allows intraarticular structures to be assessed accurately, thereby improving the diagnostic capabilities, and it broadens the spectrum of surgical techniques feasible for treatment of articular pathologies in cattle.

This study aimed to assess for cattle the described arthroscopic approaches to the shoulder joint of horses, and to describe the appearance of the corresponding intraarticular structures of the shoulder joint. Additionally, to perform histological examination where tissues were identified and assessed arthroscopically, but the tissue type was uncertain using cadaveric limbs from cattle of different age categories without any signs of orthopedic diseases of the front limbs.

Results

An anatomic and arthroscopic investigation with 34-cadaveric forelimbs from 20-cattle was performed. The arthroscope was inserted either immediately cranial or 1-cm caudal to the tendon of the infraspinatus muscle for the cranial and caudal approaches, respectively. The shoulder joints were examined with the limbs in either horizontal non-pulled position, abducted non-pulled position using a three-pod limb holder adjustable in height, or horizontal manually pulled position. Arthroscopy was performed using a rigid 30°arthroscope (18-cm length, 4-mm outer diameter) to view the synovial pouches with their synovial villi and the following structures: cranial rim of the glenoid, cranial portion of the humeral head, incisura-glenoidalis, caudal rim of the glenoid, caudal portion of the humeral head, and cranial and caudal cul-de-sac. Abduction of the limb allowed improved visualization of the lateral portion of the joint. Pulling the limb facilitated investigation of the medial portion of the joint. Generally, the distention range was higher in younger as compared to adult cattle, and visualization of the medial portion of the joint was, therefore, facilitated in younger animals. The main complications observed were subcutaneous fluid extravasations and partial-thickness articular cartilages wear-lines.

Conclusion

The described arthroscopic techniques allowed good overall visualization of the most relevant anatomical structures within the healthy cadaveric joint. Further investigations are warranted to evaluate the diagnostic and therapeutic applications of these techniques and the prognosis of arthroscopic surgery as a tool for the treatment of joint lesions.

Arthroscopic reattachment of osteochondritis dissecans lesions using resorbable polydioxanone pins

REASONS FOR PERFORMING STUDY

Debridement of osteochondritis dissecans (OCD) cartilage lesions results in fibrocartilage and imperfect hyaline repair tissue, and forms a permanent irregularity to the subchondral bone plate.

OBJECTIVE

To evaluate the clinical, radiographic and outcome effects of OCD cartilage flap reattachment for select lesions as an alternative to OCD debridement.

HYPOTHESIS

Separated cartilage flaps resulting from OCD lesions may be re-incorporated into the hyaline cartilage surface by reattachment rather than debridement and removal.

METHODS

Resorbable polydioxanone pins were used to reattach OCD flap lesions in 16 joints of 12 horses. Criteria for attachment, rather than removal, included an unmineralised cartilage flap on preoperative radiographs and a relatively smooth surface with some residual perimeter attachment at surgery.

RESULTS

There were 12 subjects, 6 males and 6 females, 7 Thoroughbred or Standardbred weanlings, 3 Warmbloods, 1 Arabian and 1 Quarter Horse, mean age at surgery 6.8 months. All horses had effusion of the affected femoropatellar joint (n = 9), tarsocrural joint (n = 1) or fetlock (n = 2). Radiographic lesions varied in length between 1.8-6.3 cm; reattachment was used in 16 of 18 affected joints and the OCD cartilage was not satisfactory for salvage in 2 stifles. Number of pins required was 2-10. One horse was subjected to euthanasia due to a tendon laceration 8 weeks after surgery; of the remaining 11 horses, mean duration of follow-up was 3.9 years (range 4 months-8 years). Nine of these were sound and had entered work, while 2 were sound but remained unbroken 4 and 6 months post operatively, respectively. Radiographic resolution of the OCD lesion occurred in 14 of 16 pinned joints in the 9 horses with long-term follow-up. The 2 remaining joints had a 3 and a 5 mm mineralised flap in the original defect sites.

CONCLUSIONS

This study indicated cartilage flap reattachment was an alternative to removal in selected OCD lesions.

POTENTIAL RELEVANCE

Relatively smooth OCD cartilage flaps may be salvaged by reattachment and can result in normal radiographic subchondral contour and a high likelihood of athletic performance. Further case numbers are required to determine which lesions are too irregular or contain too much mineral for effective incorporation after reattachment.

Scapulohumeral arthrodesis in miniature horses

OBJECTIVES

To describe surgical arthrodesis of the scapulohumeral joint and to evaluate its efficacy in reducing morbidity associated with severe shoulder dysfunction in miniature horses.

STUDY DESIGN

Retrospective study.

ANIMALS

Four miniature horses.

METHODS

Medical records and radiographs were reviewed for history, physical examination findings, lameness evaluation, radiographic evaluation, surgical techniques, postoperative complications, and outcome. A 10- or 11-hole, 4.5-mm narrow dynamic compression plate and 4.5-mm cortical screws were applied to the cranial surface of the scapula and cranial surface of the humerus after osteotomy of the intermediate tubercle. In most horses, 1 or 2 screws were inserted in lag fashion across the joint, through holes in the plate.

RESULTS

Scapulohumeral osteoarthritis was diagnosed radiographically in 4 horses, and 3 horses had concurrent shoulder luxation or subluxation. All horses had grade 3 or 4 lameness before surgery, and most improved by 1 to 2 grades after surgery. Despite complications of implant failure (2 horses), infection (2 horses), scapular fracture (1 horse), and atrophy of the shoulder muscles (1 horse), functional arthrodesis reduced morbidity in all horses.

CONCLUSIONS

Scapulohumeral arthrodesis facilitates early return to weight bearing in miniature horses with severe scapulohumeral joint osteoarthrosis. Despite functional gait abnormality, the horses ambulated quite well after surgery.

CLINICAL RELEVANCE

Scapulohumeral arthrodesis should be considered for debilitating conditions of the shoulder joint in miniature horses, especially when the intended outcome is breeding or pasture soundness.

Subchondral cystic lesions of the proximal extremity of the tibia in horses: 12 cases (1983-2000)

OBJECTIVE

To determine clinical and radiographic features of subchondral cystic lesions (SCL) of the proximal extremity of the tibia in horses that could be used to classify these lesions as being related to osteochondrosis or osteoarthritis and to evaluate results of surgical debridement.

DESIGN

Retrospective study.

ANIMALS

12 horses with 14 SCL.

PROCEDURE

Medical records and radiographs obtained before and after treatment were reviewed.

RESULTS

In 6 young horses (8 lesions), SCL were considered to be related to osteochondrosis; all involved the lateral tibial condyle. The remaining 6 horses were mature and had radiographic evidence of osteoarthritis in addition to SCL. Arthroscopic debridement was performed in 4 horses in which lesions were considered to be a result of osteochondrosis and in 3 horses with osteoarthritis. Three horses in which SCL were considered to be a result of osteochondrosis performed athletically after debridement. Two horses with moderate osteoarthritis returned to work after arthroscopic debridement but at a lower level of athletic performance. One horse with SCL related to osteochondrosis responded to medical treatment and went on to race.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that arthroscopic debridement of SCL is feasible in horses in which lesions involve the cranial portion of the lateral or medial tibial condyle, and that treated horses may be able to perform athletically.

Diagnostic findings and prognosis following arthroscopic treatment of subtle osteochondral lesions in the shoulder joint of horses: 15 cases (1996-1999)

OBJECTIVE

To determine clinical, scintigraphic, radiographic, and arthroscopic findings and results of treatment in horses with lameness attributable to subtle osteochondral lesions of the shoulder joint.

DESIGN

Retrospective study.

ANIMALS

15 horses.

PROCEDURE

Medical records were reviewed, and results of physical examination, scintigraphy, radiography, arthroscopy, and treatment were recorded.

RESULTS

Severity of lameness ranged from grade 1 to 4. Response to shoulder flexion or extension was variable. Twelve horses had a narrow upright foot. Intra-articular anesthesia of the shoulder joint localized the cause of the lameness to the shoulder joint in 9 of 10 horses. Scintigraphic abnormalities were detected in 4 of 6 horses. Radiographic lesions were subtle and included glenoid sclerosis, focal glenoid lysis, small glenoid cysts, and alterations in the humeral head contour. Arthroscopic evaluation confirmed clefts in the glenoid cartilage, glenoid cysts, a humeral head cyst, fibrillation of the humeral head cartilage, cartilage fragmentation, or a nondisplaced fracture of the humeral head. After treatment, 12 horses returned to their previous level of performance, 1 was sound for light riding, 1 remained lame, and 1 was euthanatized because of chronic lameness.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that a combination of physical examination, scintigraphy, and radiography is necessary to diagnose subtle osteochondral lesions of the shoulder joint in horses. Arthroscopy can be used to confirm the diagnosis and treat cartilage and subchondral bone lesions. Young and middle-aged horses with subtle osteochondral lesions of the shoulder joints have a good prognosis for return to performance following arthroscopic treatment.

Arthroscopic treatment of osteochondritis dissecans in the canine shoulder

Twenty-three shoulders of 21 dogs were treated arthroscopically for osteochondritis dissecans (OCD). Thirteen dogs had bilateral lesions detectable radiographically; however, only two dogs had arthroscopic surgery on both shoulders. Arthroscopic procedures included removal of the osteochondral flap, curettage of the subchondral defect, and partial synovectomy. Fourteen dogs were using the treated limb within 1 day and eight dogs within 2 days, although some lameness may have persisted for several weeks. Force plate evaluation was effective for comparison of preoperative and postoperative mean peak force/body weight (PF/BW) values. Improvement was detected objectively in 9 of the 10 dogs returned for postoperative force plate analysis. All owners were satisfied with the cosmetic results and the rapid return to function.

Review of pathogenesis and treatment of degenerative joint disease

Treatment of degenerative joint disease (osteoarthritis) is discussed in relationship to pathogenesis of five clinical entities, defined to facilitate discussion:-1) occurring in high motion joints and associated with synovitis; 2) associated with low motion joints; 3) "non-progressive" articular cartilage erosion; 4) secondary to other identified problems (intra-articular fractures, ligamentous damage, wounds, septic arthritis, osteochondrosis); and 5) chondromalacia of the patella. In addition to direct damage to articular cartilage, synovitis and capsulitis and depletion of matrical glycosaminoglycans and proteoglycans play important roles. The natural healing response in damaged articular cartilage is inadequate. The principles of treatment are divided into: 1) prevention or treatment of primary causes. These include the effects of track surface, shoeing, and the appropriate resolution of intra-articular fractures, septic arthritis and osteochondritis dissecans. 2) treatment of active soft tissue disease contributing to articular cartilage degeneration, including rest, physical therapy, synovectomy and administration of anti-inflammatory drugs, sodium hyaluronate and polysulfated glycosaminoglycans. 3) attempts at treatment of articular cartilage loss or degeneration, including articular cartilage curettage, subchondral bone drilling, osteophyte removal, articular cartilage grafting and arthrodesis.