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Osteoarthritis of the Proximal Interphalangeal Joint in Horses

By

Matthew T. Brokken

, DVM, The Ohio State University

Last full review/revision Sep 2015 | Content last modified Oct 2015
Topic Resources

Osteoarthritis of the proximal interphalangeal joint (high ringbone) is a common cause of lameness in many types of horses used for a variety of disciplines. The osteoarthritic process can start as a single traumatic episode or as a result of “wear and tear,” or overuse. Other causes of osteoarthritis of this joint are infection and developmental orthopedic disease. The proximal interphalangeal joint is a lower motion joint that is somewhat unforgiving to high loads placed upon it. Osteoarthritis is characterized by cartilage loss and periarticular new bone formation. In the chronic, progressive osteoarthritic pastern, lameness is typically subtle at first and becomes more noticeable as the disease progresses. Radiographic findings may include periarticular new bone formation, subchondral lysis and/or sclerosis, and loss of joint space (typically the medial aspect of the joint). In the early stages of disease, diagnostic analgesia is typically required to localize the lameness. In addition, a positive response may be seen on lower limb flexion. Oral or intra-articular anti-inflammatory medication may relieve the signs of lameness temporarily. The use of intra-articular ethanol injection into the proximal interphalangeal joint has been described. If surgical fusion is not an option, multiple injections were successful in some horses for facilitated ankyloses. Surgical arthrodesis of the pastern joint is frequently required to successfully restore performance. Typically, this involves a combination of plate(s) and screw(s). In a retrospective study of 53 horses that had a proximal interphalangeal joint arthrodesis using a combination plate-screw technique (81% forelimb, 95% hindlimb), 87% of horses with follow-up were used as intended. Deterioration of articular cartilage within the metacarpal/tarsophalangeal joint is a common injury in racehorses and can lead to development of periarticular osteophytes, enthesophytes, and joint space collapse. In young, training horses, periosteal bone can form on the dorsal aspect of the distal metacarpus and the proximal aspect of the proximal phalanx, often involving the joint capsule (osselets). Osteoarthritis is often secondary to a primary abnormality such as a chip fracture or osteochondrosis (see Osteochondrosis of the Stifle in Horses). Treatment typically has two goals: reducing pain and minimizing further joint deterioration. The judicious use of anti-inflammatories (eg, NSAIDs, corticosteroids) can provide pain relief. Newer biologic therapies (platelet-rich plasma, stem-cell therapy, interleukin-1 receptor antagonist protein) may help slow down or arrest the progression of osteoarthritis. In severe, advanced cases, arthrodesis of the joint is necessary to provide pain relief.

OTHER TOPICS IN THIS CHAPTER

Lameness in Horses
Overview of Lameness in Horses
The Lameness Examination in Horses
Imaging Techniques in Equine Lameness
Arthroscopy in Equine Lameness
Regional Anesthesia in Equine Lameness
Disorders of the Foot in Horses
Osseous Cyst-like Lesions in the Distal Phalanx in Horses
Bruised Sole and Corns in Horses
Canker in Horses
Fracture of Navicular Bone in Horses
Fracture of Distal Phalanx in Horses
Keratoma in Horses
Laminitis in Horses
Navicular Disease in Horses
Pedal Osteitis in Horses
Puncture Wounds of the Foot in Horses
Pyramidal Disease in Horses
Quittor in Horses
Quarter Crack in Horses
Scratches in Horses
White Line Disease in Horses
Sheared Heels in Horses
Sidebone in Horses
Thrush in Horses
Disorders of the Pastern and Fetlock
Fractures of the First and Second Phalanx in Horses
Fractures of the Proximal Sesamoid Bones in Horses
Osteoarthritis of the Proximal Interphalangeal Joint in Horses
Palmar/Plantar Metacarpal/Metatarsal Nonadaptive Bone Remodeling in Horses
Sesamoiditis in Horses
Chronic Proliferative Synovitis in Horses
Digital Sheath Tenosynovitis in Horses
Disorders of the Metacarpus in Horses
Tendinitis in Horses
Suspensory Desmitis in Horses
Inferior Check Desmitis in Horses
Bucked Shins in Horses
Exostoses of the Second and Fourth Metacarpal Bones in Horses
Fractures of the Small Metacarpal (Splint) Bones in Horses
Fracture of the Third Metacarpal (Cannon) Bone in Horses
Disorders of the Carpus in Horses
Fracture of the Carpal Bones in Horses
Subchondral Bone Disease of the Third Carpal Bone in Horses
Tearing of the Medial Palmar Intercarpal Ligament in Horses
Osteoarthritis of the Carpus in Horses
Distal Radial Exostosis and Osteochondroma of the Distal Radius in Horses
Carpal Hygroma in Horses
Rupture of the Common Digital Extensor Tendon in Horses
Disorders of the Shoulder in Horses
Developmental Diseases of the Shoulder in Horses
Fractures of the Shoulder in Horses
Bicipital Bursitis in Horses
Infection of the Shoulder in Horses
Suprascapular Neuropathy in Horses
Osteoarthritis of the Shoulder in Horses
Disorders of the Elbow in Horses
Developmental Orthopedic Disease in the Elbow of Horses
Fractures of the Elbow in Horses
Osteoarthritis of the Elbow in Horses
Collateral Ligament Injury in the Elbow of Horses
Disorders of the Metatarsus in Horses
Bucked Shins/Dorsal Cortical Fractures of the Third Metatarsal Bone in Horses
Exostoses of the Metatarsal Bones in Horses
Diaphyseal Fracture of the Third Metatarsal Bone in Horses
Incomplete Longitudinal Fractures of the Plantar Aspect of the Third Metatarsal Bone in Horses
Focal Bone Reaction and Avulsion Fractures of the Third Metatarsal Bone in Horses
Fractures of the Second and Fourth Metatarsal Bones in Horses
Enostosis-like Lesions of the Third Metatarsal Bone in Horses
Disorders of the Tarsus in Horses
Failure of Ossification of the Distal Tarsal Bones in Horses
Osteoarthritis of the Distal Tarsal Joints in Horses
Osteoarthritis of the Talocalcaneal Joint in Horses
Osteoarthritis of the Tarsocrural Joint in Horses
Synovitis/Capsulitis of the Tarsocrural Joint in Horses
Osteochondrosis of the Tarsocrural Joint in Horses
Osteitis of the Calcaneus in Horses
Fractures of the Distal Tarsal Bones in Horses
Fracture of the Talus in Horses
Fracture of the Fibular Tarsal Bone (Calcaneus) in Horses
Fracture of the Lateral Malleolus of the Tibia in Horses
Tarsal Joint Luxation in Horses
Desmitis of the Collateral Ligaments of the Tarsus in Horses
Rupture of the Fibularis (Peroneus) Tertius in Horses
Stringhalt
Curb in Horses
Disorders of the Tarsal Sheath in Horses
False Thoroughpin in Horses
Luxation of the Superficial Digital Flexor Tendon from the Tuber Calcanei in Horses
Gastrocnemius Tendinitis in Horses
Calcaneal Bursitis in Horses
Capped Hock
Disorders of the Stifle in Horses
Osteochondrosis of the Stifle in Horses
Subchondral Cystic Lesions in Horses
Meniscus and Meniscal Ligament Injuries in Horses
Cranial and Caudal Cruciate Ligament Injuries in Horses
Collateral Ligament Injuries in Horses
Intermittent Upward Fixation of the Patella and Delayed Patella Release in Horses
Fragmentation of the Patella in Horses
Patellar Luxation in Horses
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Lameness
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