Orthopedic Disorders PDF

Orthopedic Disorders 22 CH A P TE R Patricia A. Schenck It is not possible to pr...

Orthopedic Disorders 22 CH A P TE R Patricia A. Schenck It is not possible to provide a complete review of the II. Clinical signs: Asymmetry of the jaw, oral hemor- anatomy, surgical approaches to the bones and joints, rhage and pain, crepitus, concurrent head and and surgical procedures in this review text. The reader is thoracic trauma encouraged to review surgical techniques, approaches, III. Diagnosis: Based on history and radiographs; CT can and anatomy using a surgery text. provide a three-dimensional (3-D) impression IV. Surgical procedures A. Preoperative considerations: Monitor neurologic FRACTURES OF THE SKULL function, and check for diaphragmatic hernia, I. Zygomatic arch fracture pneumothorax, and other conditions A. Preoperative considerations B. Anesthetic considerations: Place an endotracheal 1. Perform a neurologic examination tube through a pharyngotomy incision. Give 2. Confirm that the optic nerve and vision is antibiotics because most mandibular fractures intact before surgery are open 3. Computed tomography (CT) provides the best C. Surgical principles: Restore normal dental occlu- assessment sion. Intramedullary pinning is not recommended B. Surgical procedure: Reduce fractures that cause D. Postoperative care: Maintain nutrition with an compression of the eye esophagostomy or gastrostomy feeding tube. If C. Postoperative care and complications: Monitor not using a feeding tube, feed a soft gruel for neurologic function. Degenerative joint disease 4 weeks post surgery. Flush the mouth daily (DJD) of the temperomandibular joint (TMJ) may with dilute chlorhexidine solution result long-term. Prognosis is good E. Complications: Malocclusion is the most impor- II. Extracranial fractures: Fractures of the nuchal crest, tant complication; osteomyelitis occurs rarely sagittal crest, or frontal sinus V. Mandibular symphyseal separations A. Preoperative considerations: Perform neurologic A. Occurs often in cats examination B. Wire stabilization is the technique of choice B. Treatment: Most are managed conservatively. VI. Mandibular body fractures Surgery is performed if displacement is severe A. Create a muzzle using tape (Figure 22-1) C. Postoperative care and complications: Monitor 1. Can be used if there is minimal displacement neurologic function. Subcutaneous emphysema of fragments may occur secondary to frontal sinus fracture 2. Difficult to do in cats or in brachycephalic III. Intracranial fractures breeds A. Preoperative considerations 3. Feed soft gruel 1. Perform a neurologic examination B. Maxillary-mandibular fixation: Either wire the 2. Most are closed fractures maxilla to the mandible or use acrylic bonding of 3. Calvarial fractures are usually associated with the canine teeth to keep the mouth closed central nervous system (CNS) compromise C. Interfragmentary wiring: For fracture fragments B. Surgical procedure: Elevate depressed calvarial that are stable without loss of bone or fractures, and remove comminuted pieces comminution C. Postoperative care and complications: Monitor D. Intraoral acrylic splint neurologic function. Prognosis is guarded for neu- E. External skeletal fixation: Best used for fractures rologic recovery that are open, comminuted, or involve bone loss F. Bone plating VII. Mandibular ramus fractures FRACTURES AND DISLOCATIONS A. Usually do not require surgical treatment because OF THE MANDIBLE displacement is minimal I. Anatomy B. Condylectomy can be performed in those that A. About 15% of all fractures in cats are of the mandible develop an inability to open the mouth B. The mandibular canal contains the mandibular ar- VIII. TMJ dislocations tery and vein and the mandibular alveolar nerve A. Usually occurs from trauma 305