Chapter 53 - Vertebral column thorax coccygeal Flashcards
What type of vertebral injuries is more common in adult horses than in foals?
Thoracolumbar
1.
In horses, life-threatening vertebral fractures are most often seen in what activity?
Jumping
Which parts of the thoracolumbar spine are typically involved in fractures?
Vertebral body and dorsal spinous processes
Where do the most common vertebral body fractures occur in horses?
First three thoracic vertebrae followed by T12
What is the recommended course of action for horses with severe disruption of the thoracolumbar spinal cord?
Euthanasia
Where do dorsal spinous process fractures tend to occur?
Thoracic vertebrae
What therapeutic approaches can be attempted when the spinal cord is intact?
Conservative therapy or stabilization with pins/plates
Fracture of the thoracic dorsal spinal processes in horses is often associated with what behavior?
Rearing and falling backward
In a report of 22 cases of thoracolumbar vertebral fractures, how many involved the vertebral body or neural arch?
15
What are common clinical signs of fractures of the dorsal spinous processes?
Local pain, swelling, and stiffness
What surgical procedure is performed for fractures of the dorsal spinous processes?
Subtotal ostectomy
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What is the preferred technique for the subtotal ostectomy of the dorsal spinous processes?
In the standing horse
For what reasons might surgery be required for dorsal spinous process fractures?
Sequestered bone fragments or position precluding saddle use
How long postoperatively is healing adequate to permit riding?
8-12 weeks
What does consist the conservative tx of thoracic and lumbar spinous processes fracture?
systemic and intralesional cortico +
shockwave/radial pressure wave therapy,
bisphosphonates
+ acupuncture careffully inserted
How do you perform the surgical intervention?
Surgical tx: sedation + local anesthesia nea incisionbut LR is preferred by most surgeons
Metalic markers forradio control ofexactly the sites of the DSPs to be resectedvLongitudinal inicision is made betweenthe most cranial and caudal of the affected DSPs
Supraspinous ligaments diveded sharply and longitudinally and retracted abaxially with Gelpi retractors
The dorsal part of DSP of 1 or morevertebra is resected àoscillating saw, osteotome, gigli wire
Gigli wire with custom-made wire guide is used hasess exposure and dissection is necessary which is why this is the preferredtechnique 2 types of procedure:
1.Resection of the entire DSP
2.Subtotal (cranial wedge) ostectomy(+ recent)
mandatory minimum of 5 mm between remaining bodies of each process resected
describe partial resection
Partial resection of the thoracic and lumbar dorsal spinousprocesses
Thedorsal 4 to 5 cm of the DSPs are dissected free of the supraspinous ligament +interspinous ligaments + adjacent muscle tissue
For the cranial wedge osteoctomy: 1stinterspinous ligament cranial to each affected DSP is sharply incised
With oscillation saw onlythe cranial portion of affected DSPs is removed in a caudodorsal-cranioventraldirection
The ventral extent of the resectionshould emerge ventral to the site of impingement
Once the** resection is complete à supraspinous ligament issutured in simple continous pattern** – skin with staples
In addition to radiography, which imaging modality is advised due to frequent oversight of fractures?
CT
What is used to document the extent of spinal cord compression in foals, small horses, ponies, and donkeys?
Myelography
What is the initial treatment for horses with little or no displacement of vertebral fragments?
Conservative management
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When is implant fixation indicated in vertebral body fractures?
When needed to provide stability
What position is the horse placed in for implant fixation surgery?
Sternal recumbency
How are the Steinmann pins inserted for stabilizing a fracture?
At an angle to the vertebra
What is critical to avoid when inserting the caudal pins?
Injuring the aorta and vena cava
What provides final rigidity in the stabilization process?
Cold-curing PMMA
Which diagnostic methods are used to examine back pain in horses?
Physical and complete orthopedic examination, including diagnostic analgesia, radiology, and scintigraphy
What conditions have been associated with back pain in horses?
Overriding DSPs,
osteoarthritis,
spondylosis
What is the common treatment for most horses with back pain?
Intralesional treatment with corticosteroids and agents like Sarapin
What surgical technique is used for the resection of the dorsal part of the DSP in horses?
esection using an oscillating saw, osteotome, gigli wire, or bone-cutting shears
Brown et al VS 2020 Long-term outcome and effect of diagnostic analgesia in horses undergoing interspinous ligament desmotomy for overriding dorsal spinous processe. Performance comparison of 159 Thoroughbred racehorses and matched cohorts before and after desmotomy of the interspinous ligamen- What was compared to determine the influence on long-term outcome? A) The type of ISLD performed
B) The use of preoperative diagnostic analgesia
C) The age of the horses
D) The breed of the horses
B) The use of preoperative diagnostic analgesia
What was the conclusion of the study regarding preoperative diagnostic analgesia?
A) It has no effect on the long-term outcome
B) It is detrimental to the long-term outcome
C) It is likely to improve the long-term outcome
D) It should be avoided as it complicates the surgery
C) It is likely to improve the long-term outcome
Which recent complication has been reported following desmotomy of the interspinous ligament?
A) Infection at the surgical site
B) Hemorrhage during surgery
C) Neurogenic atrophy of the contralateral epaxial muscle
D) Complete recovery without side effects
C) Neurogenic atrophy of the contralateral epaxial muscle
EVJ 2021 Derham et al Implications of the neuroanatomy of the equine thoracolumbar vertebral column with regional anaesthesia and complications following desmotomy of the interspinous ligament What are impinging/overriding dorsal spinous processes (DSPs) of the thoracolumbar vertebrae known to cause in horses?
A) Improved performance
B) Poor performance
C) Increased flexibility
D) Better balance
B) Poor performance
What do the authors suggest as the cause of this complication?
A) An allergic reaction to medication
B) A more lateral approach than previously described, possibly transecting a nerve
C) Poor surgical technique
D) Inadequate postoperative care
B) A more lateral approach than previously described, possibly transecting a nerve
What is hypothesised to be the cause of post-operative neurogenic atrophy?
A) Transection of an intermediate branch of the dorsal spinal nerve supplying the m. longissimus
B) Genetic predisposition to muscle atrophy
C) The horse’s activity level post-surgery
D) Age-related muscle degeneration
A) Transection of an intermediate branch of the dorsal spinal nerve supplying the m. longissimus
What does the review article highlight regarding the equine thoracolumbar region?
A) There is an abundance of detailed knowledge about neural anatomy
B) Surgical techniques in this area are well-standardized
C) There is a lack of anatomical knowledge in the literature
D) Local anaesthesia is always effective in localising pain in the equine back
C) There is a lack of anatomical knowledge in the literature
Prisk et al VS 2019 Long-term prognosis for return to athletic function after interspinous ligament desmotomy for treatment of impinging and overriding dorsal spinous processes in horses: 71 cases (2012-2017) - What percentage of horses returned to some level of performance post-ISLD?
A) 37.5%
B) 52.9%
C) 78.6%
D) 91.1%
D) 91.1%
Prisk et al VS 2019 What did the study conclude about the influence of radiographic and scintigraphic grades on the return to performance?
A) They are strong predictors of return to performance
B) They have no influence on the return to performance
C) Only radiographic grades are influential
D) Only scintigraphic grades are influential
B) They have no influence on the return to performance
de Souza et al. 2021 (Vet Surg) - Minimallyinvasive cranial ostectomy for the treatment of impinging dorsal spinousprocesses in 102 standing horses- Main important factor is the rongeur. What are themeasurements?
Cranial ostectomy of theCAUDAL DSP with Stille Lueror Leksell-Stille bone rongeurs
●4-8 bites, ensure >5mm gap achieved, 4 cm depth●
●Dimensions of rongeurs CRUCIAL
20-24cm length, jaw length 20-30mm,
jaw width 10-15mm
Prisk et al VS 2019 What was the satisfaction level among owners regarding their horses’ postoperative performance levels?
A) 37.5%
B) 52.9%
C) 78.6%
D) 82.1%
C) 78.6%
What percentage of horses had complete resolution of clinical signs and returned to intended work after the procedure?
A) 69%
B) 80%
C) 93%
D) 100%
B) 80%
What typically causes trauma to the sacral area in horses?
Suddenly dog-sitting or falling over backward
What are the symptoms of compressive lesions of the sacrum in horses?
Pain and swelling over the croup and tail head, tail weakness or paralysis, decreased anal tone, retention of feces, bladder distention, and urine dribbling
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How are sacral area injuries in horses initially treated?
With antiinflammatory drugs and observation for up to 10 days
What is the recommended action if there is no improvement in the horse’s condition after 10 days of an acute sacral injury?
Consider surgical intervention or euthanasia
What surgical procedure can be performed for decompression of the sacrum in horses?
Surgical decompression by removing the spinous processes and dorsal laminae of the sacral vertebrae
How many coccygeal vertebrae do horses typically have?A) 10B) 16C) 18D) 20
C) 18
What is a common consequence of trauma to the base of the tail in horses?
Vertebral fracture, soft tissue injury, and neurapraxia of the motor nerves
What diagnostic tool is useful for evaluating tail fractures in horses?
Radiographs
Figure 53-24. Horse that sustained multiple fractures of the dorsal spinous processes and was treated conservatively. Note the flat contour of the withers.
Figure 53-25. Laterolateral radiographic view showing fracture (arrows) of the dorsal spinous processes.
Figure 53-27. Three dimensional–computed tomography reconstruction of a comminuted fracture (arrow) of the second thoracic vertebra in a horse that ran into a tree and was paralyzed immediately after the injury.
Figure 53-28. (A) Laterolateral radiographic view showing impingement of the thoracic dorsal spinous processes in a sport horse (arrow). (B) Laterolateral radiographic view during preparation for surgery (spinal needles were inserted between the dorsal spinous processes, and skin staples were used to assist in the identification of the involved spinous processes. (C) Laterolateral radiographic view taken immediately after surgery. (D) Laterolateral radiographic view taken 1 year postoperatively showing excellent healing without complication; no bony reactions are noted at the insertion point of the interspinous ligament.
How do you manage a worse with cocygeal fracture?
Most horses with fractures of the coccygeal vertebrae are managed conservatively with stall rest and the use of antiinflammatory drugs
What are the options for coccygeal fractures treatment?
- Closed fracture is conservative
- open fracture = debridement with longitudinal incision dorsal or ventral
- Tail amputation
Figure 53-29. (A) Intraoperative view of fixation of a comminuted fracture of the sacrum using a narrow 6-hole 4.5/5.0-mm locking compression plate. (B) Laterolateral radiographic view of the horse shown
in Figure 53-45 taken immediately postoperatively.
Describe the tail amputation
Epidural and local anesthesia
Standing under sedation
A penrose drain or Esmarch bandage is placed tightly around the most cranial aspect of the tail to reduce hemorrhage during surgery.
Two flaps are created from the dorsal and ventral ends of the skin.
The points of these flaps are facing caudally and should be located caudal to the site of amputation to allow enough soft tissue for wound closure.
A scalpel is used to transect between two coccygeal vertebrae at the site of the amputation.
Disc material and cartilage is removed with a curette to expose a vascularized bony surface that supports healing.
The subcutaneous tissues and skin are closed in routine fashion.
A stent bandage is applied to the incision and covered with an adhesive barrier drape to keep the area clean and dry during recovery from anesthesia
Which spinal cord segments are suggested to be intact if a mare has normal micturition and defecation without hind limb ataxia?
S1-S4
Injury to which spinal cord segments can result in abnormal micturition and defecation in horses?
Sacral segments S1-S4
The mare’s lack of sensation to the perineum and initial absence of anal tone suggest damage to which nerve?
Caudal rectal nerve
The lack of sensation and motor function to the tail are likely due to damage to which nerve?
Coccygeal nerve
What is a major concern following the complete amputation of a horse’s tail?
Lack of insect control.
What type of trauma does the presence of a hematoma in the tail suggest?
Tension-induced trauma to blood vessels
What is used for fixation in the treatment of cranial coccygeal fractures?
Locking compression plates (LCPs) and/or pins
Which of the following are examples of malformational abnormalities?
Hemivertebrae, butterfly vertebrae, and block vertebrae.
What may asymmetric fusion between the atlas and the occipital bones lead to?
The development of scoliosi
The dens of the axis in horses with OAAM is typically what?
Hypoplastic.
In which breed is OAAM most frequently reported?
Arabian foals.
What clinical sign may be elicited by manipulating the head of a horse with OAAM?
A clicking sound.
How do clinical signs of OAAM progress over time?
They worsen due to repetitive or persistent spinal cord compression
What is required for a definitive diagnosis of OAAM?
A systematic neurological examination and two orthogonal radiographic views.
Which imaging modalities are best for evaluating OAAM?
CT and MRI.
When is OAAM typically detected?
At birth or within the first few weeks of life.
