Disorders of the back and pelvis in horses

Disorders of the Equine Back and Pelvis:

I. Clinical Overview and Diagnostic Principles
- Significance: These disorders are a major cause of poor performance and gait abnormalities in sport and racehorses.
- The Compensatory Link: There is a complex relationship between back pain and subtle bilateral hindlimb lameness; determining which is the primary pathology is often difficult.
- Diagnostic Approach: Definitive diagnosis is challenging and usually requires integrating multiple imaging modalities, including radiography, ultrasonography, and nuclear scintigraphy.

Disorders of Spinal Processes and Ligaments:

Kissing Spines (Impingement of Dorsal Spinous Processes)
- Location: Most common between T10 and T18, but also found between L1 and L6.
- Grading System: Ranges from Grade 1 (narrowing of space) to Grade 4 (severe remodeling).
- Clinical Presentation: Frequency varies by discipline; lesions can exist in racehorses and sport horses without clinical pain.
- Management: Includes local steroid injections, shock wave therapy, and specialized rehabilitation; surgical resection or desmotomy is reserved for cases failing medical management.
- Fractures of Spinal Processes
  1. Cause: Typically occurs in horses that rear and fall over backward.
  2. Location: Usually involves T4 through T10.
  3. Prognosis: Recovery is generally satisfactory with no permanent effect on performance, though withers deformation may require saddle adjustments.
- Supraspinous Desmopathies (Ligament Injuries)
  1. Diagnosis: Identified via ultrasonography by ligament thickening and altered architectural patterns.
  2. Enthesopathy: Indicated by bone surface alterations at the top of the spinous processes.

Disorders of Vertebral Bodies and Disks:

Vertebral Spondylosis: Bony proliferation found mainly in the midthoracic area (T11–T13); generally considered rare and not clinically important.
Congenital Abnormalities: Rare deformities like triangular or trapezoidal vertebrae usually located in the thoracic region.
Osteomyelitis: Can occur with or without diskospondylitis, most commonly in the thoracolumbar spine of foals.
Fractures: Result from severe trauma or falls (common in jumping races); often lead to paraplegia and carry a grave prognosis.

Muscle Strain and Soreness:

Prevalence: Muscle injury is the most common cause of back soreness in horses.
Primary Target: Usually involves the longissimus dorsi muscle.
Soreness Sites: Primarily localized to the caudal withers and cranial lumbar regions.
Management: Responds to rest (several weeks), NSAIDs, muscle relaxants, and physiotherapy.

Osteoarthritis of Articular Process Complexes (Facet Joints):

- Anatomy: Located dorsal to the vertebral canal at the 10-o'clock and 2-o'clock positions.
- Imaging Findings: Radiography and ultrasonography reveal sclerosis, joint space narrowing, and periarticular new bone.

- Management: Focused on ultrasonographically-guided steroid injections, shock wave therapy, and specific mobilization protocols.

Sacroiliac (SI) Joint Abnormalities:

Acute Strain: Associated with severe injury, pelvic pain, and marked hindlimb lameness.
Chronic Disease: Characterized by back soreness, poor performance, and intermittent toe dragging.
Diagnostic Challenge: Often requires a combination of physical exams, scintigraphy, and rectal ultrasonography to assess the ventral aspect of the joint.

Diagnostic Risk: Local anesthetic infiltration of the SI joint to confirm pain carries a risk of sciatic nerve paralysis.
Management: Supportive care including periarticular steroids, shock wave, and exercises to develop the gluteal muscles.

Disorders of the back and pelvis in horses

Disorders of the Equine Back and Pelvis:

I. Clinical Overview and Diagnostic Principles

Significance: These disorders are a major cause of poor performance and gait abnormalities in sport and racehorses.

The Compensatory Link: There is a complex relationship between back pain and subtle bilateral hindlimb lameness; determining which is the primary pathology is often difficult.

Diagnostic Approach: Definitive diagnosis is challenging and usually requires integrating multiple imaging modalities, including radiography, ultrasonography, and nuclear scintigraphy.

Disorders of Spinal Processes and Ligaments:

Kissing Spines (Impingement of Dorsal Spinous Processes)

Location: Most common between T10 and T18, but also found between L1 and L6.

Grading System: Ranges from Grade 1 (narrowing of space) to Grade 4 (severe remodeling).

Clinical Presentation: Frequency varies by discipline; lesions can exist in racehorses and sport horses without clinical pain.

Management: Includes local steroid injections, shock wave therapy, and specialized rehabilitation; surgical resection or desmotomy is reserved for cases failing medical management.

Fractures of Spinal Processes

Cause: Typically occurs in horses that rear and fall over backward.

Location: Usually involves T4 through T10.

Prognosis: Recovery is generally satisfactory with no permanent effect on performance, though withers deformation may require saddle adjustments.

Supraspinous Desmopathies (Ligament Injuries)

Diagnosis: Identified via ultrasonography by ligament thickening and altered architectural patterns.

Enthesopathy: Indicated by bone surface alterations at the top of the spinous processes.

Disorders of Vertebral Bodies and Disks:

Vertebral Spondylosis: Bony proliferation found mainly in the midthoracic area (T11–T13); generally considered rare and not clinically important.

Congenital Abnormalities: Rare deformities like triangular or trapezoidal vertebrae usually located in the thoracic region.

Osteomyelitis: Can occur with or without diskospondylitis, most commonly in the thoracolumbar spine of foals.

Fractures: Result from severe trauma or falls (common in jumping races); often lead to paraplegia and carry a grave prognosis.

Muscle Strain and Soreness:

Prevalence: Muscle injury is the most common cause of back soreness in horses.

Primary Target: Usually involves the longissimus dorsi muscle.

Soreness Sites: Primarily localized to the caudal withers and cranial lumbar regions.

Management: Responds to rest (several weeks), NSAIDs, muscle relaxants, and physiotherapy.

Osteoarthritis of Articular Process Complexes (Facet Joints):

Anatomy: Located dorsal to the vertebral canal at the 10-o'clock and 2-o'clock positions.

Imaging Findings: Radiography and ultrasonography reveal sclerosis, joint space narrowing, and periarticular new bone.

Management: Focused on ultrasonographically-guided steroid injections, shock wave therapy, and specific mobilization protocols.

Sacroiliac (SI) Joint Abnormalities:

Acute Strain: Associated with severe injury, pelvic pain, and marked hindlimb lameness.

Chronic Disease: Characterized by back soreness, poor performance, and intermittent toe dragging.

Diagnostic Challenge: Often requires a combination of physical exams, scintigraphy, and rectal ultrasonography to assess the ventral aspect of the joint.

Diagnostic Risk: Local anesthetic infiltration of the SI joint to confirm pain carries a risk of sciatic nerve paralysis.

Management: Supportive care including periarticular steroids, shock wave, and exercises to develop the gluteal muscles.