Assessment & Treatment of Fractures and Dislocations of the Thoracic and Lumbar Spine. Brian Drew, MD

Transcription

1 Assessment & Treatment of Fractures and Dislocations of the Thoracic and Lumbar Spine Brian Drew, MD

2 Introduction Mechanism of injuries to the thoracolumbar spine Assessment of spinal stability Treatment Non-surgical Surgical

3 Anatomy of Thoracic Spine Normal kyphotic alignment Narrow spinal canal Transverse facet orientation Rib and sternum increase stability Conus at T12-L1

4 Anatomy of Lumbar Spine Normal lordotic alignment Larger vertebral bodies Biplanar facet orientation Cauda equina

5 Thoracolumbar Junction Major Transition Zone Kyphosis to lordosis Stiff thoracic to mobile lumbar Spinal cord to conus to cauda

6 Clinical Assessment Associated Injuries 28% have other major organ system injuries Noncontiguous spine fractures 3-17% Always monitor hematocrit and urine output GI prepare for ileus Retroperitoneal bleeding from fracture Gastroparesis from trauma Meyer 85

7 Radiographic Evaluation Initial Trauma Series: (Classic ATLS) Lateral cervical, chest, AP pelvis Secondary spine films determined by individual condition and MOI Trauma protocols with CT scans of chest, abd. and pelvis provide much more information; Challenges necessity for plain films Obtunded patients require further skeletal survey, secondary survey essential

8 Additional Imaging CT scan bony injuries MRI soft tissue imaging: Spinal cord, intervertebral discs, ligamentous structures

9 Classification of Thoracic and Lumbar Fractures 1. Which injuries are stable?? 2. Which injuries benefit from spinal cord decompression?? 3. Which injuries require surgical stabilization??

10 Classification of Thoracic and Lumbar Fractures Founding Fathers of Classification Nicoll stable vs. unstable Holdsworth 2 column theory Denis 3 column injury Ferguson and Allen mechanistic classification McAfee- Identified the stable burst fracture

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14 Stable Burst Fracture Failure of anterior and middle columns Predominantly axial load No posterior column disruption Stable injuries < 50% retropulsion <20 degrees kyphosis

15 Burst Fractures

16 L2

17 Unstable Burst Fracture Posterior column involvement!!! Distraction or translation/rotation injury mechanisms

18 Spinal Stability Mechanical stability: maintain alignment under physiologic loads without significant onset of pain or intolerable deformity Neurologic stability: prevent neural signs or symptoms under anticipated loads

19 Mechanical Stability 2-column theory (Holdsworth, 53) anterior= vertebral body, disc, ALL, PLL posterior= neural arch, Posterior ligament complex 3-column theory (Denis 83) middle = posterior ½ vertebral body, posterior disc, posterior longitudinal ligament (PLL)

20 Holdsworth : PLC is key to stability!!! Re-confirmed James, et al 94 Posterior lig. complex more important to in vitro resistance versus kyphosis Denis: MIDDLE COLUMN is key to stability No anatomic basis Stable burst fracture defies definition

21 How Can We Detect Instability? Dynamic: deformity worsens under physiologic loads acute kyphosis with standing progressive kyphosis over time Static: Inferred from imaging Plain films- widened spinous processes, biplanar deformity CT - facet complex disruption MRI- disrupted PLC

22 Instability (Textbook definition) Relies on historical standards >50 % loss of height implies PLC injury >30 º Cobb kyphosis implies PLC injury Direct MRI visualization of a disrupted PLC *****However, little clinical data to support these guidelines.*******

23 Neurologic Stability Defined by the neurological findings at time of presentation and Reflects the (remaining) intrinsic ability of the spinal column to protect the neural elements from (further) damage under anticipated loads Related to mechanical stability Crucial for intact and incomplete SCI

24 Initial radiographs usually supine Alignment appears acceptable without load Upright load can cause deformity If unstable, deformity will progress or neurological signs will occur Deformity (Kyphosis)

25 Biomechanics of Thoracic Injuries Center of Gravity: Anterior to the vertebral body with axial load - Posterior ligamentous tension band Potential for KYPHOTIC deformity

26 Biomechanics of Lumbar Injuries Center of Gravity: Posterior ½ vertebral body Lordotic alignment protective Potential for 2 0 flexion moment (seat belt)

27 Biomechanical Studies Roaf, 1960 pure axial load or pure flexion leads to little posterior ligamentous injury Nagel, degrees of kyphosis or 10 degrees lateral angulation implies incompetence of PLL and posterior elements, thus inferring instability

28 Biomechanical Studies Panjabi, 1981 it takes sectioning of PLL and posterior annulus to destabilize a motion segment with the addition of facet capsule and interspinous ligament disruption James et al, 94 middle column offers little additional resistance to kyphosis with increasing axial load

29 Management of Thoracic and Lumbar Injuries CONTROVERSIAL!!!!

30 Non-Operative Treatment of Thoracic Spine Injuries Brace or Cast Treatment Compression Fractures Stable Burst Fractures Pure Bony Flexion-Distraction Injury

31 Surgical Management of Thoracolumbar Injuries Unstable burst fractures Purely ligamentous Facet dislocations Translational/rotational injuries Neurologic deficits????

32 Treatment Guidelines Incomplete neurological injury:surgery may potentiate neural recovery and facilitate earlier rehabilitation Complete neurological deficits: Operative stabilization will hasten onset of rehabilitation Neurologically intact: non-operative treatment unless significant deformity or posterior complex injury

33 Goals of Surgical Treatment To decompress compromised neural elements in the face of a neurologic deficit To protect intact or incompletely injured neural elements To stabilize the unstable spine To restore/ improve sagittal balance

34 How Do We Achieve These Goals? Decompression Fixation for acute correction and stability Fusion with bone graft for long-term maintenance of reduction/ stability

35 Canal Decompression Complete SCI Complete SCI (after spinal shock resolves): regardless of treatment method, shows little functional improvement Intact neurological status Intact neuro status: regardless of x-ray appearance, neurologic status can t get better than normal

36 Canal Decompression Incomplete neuro deficit with canal compromise Does surgery improve neurological recovery? Current literature lacks supportive evidence

37 Decision to Decompress Location of SCI Little functional benefit seen with 1 or 2 level improvement in upper thoracic (>T9) cord injuries Conus (T10-L1) lesions are critical: bowel/bladder Low lumbar--roots more accommodating to canal compromise, and more apt to recover independent of decompression Completeness of SCI

38 Surgery: Anterior versus Posterior Anterior More predictable/safer decompression Saves levels Avoids posterior musculature SRS,1992 may be indicated for bladder dysfunction Posterior More familiar approach Usually requires more levels Early indirect reductions successful Quicker, often better tolerated early

39 Neurologic Decompression Anterior corpectomy: Visualize cord Safest and most predictable form of decompression Alternative: Indirect decompression Lordosis and distraction Relies on annulus to reduce retropulsed fragment through ligamentotaxis

40 Methods of Decompression Anterior Decompression = Gold Standard Most common in thoracic and thoracolumbar regions Direct visualization of cord facilitates removal of retropulsed fragments Readily combined with reconstruction and fusion Treatment of choice for burst fractures with incomplete SCI In presence of posterior lig injuries may require A/P surgery

41 Surgical Approaches Posterior Approach Fractures at T6 or above Posterior ligament complex injury Multi-level injury Associated chest trauma Anterior Approach Ideal for T6 and lower Decompression via corpectomy Reconstruction with strut graft and anterior instrumentation May combine with post stabilization

42 Methods of Decompression Laminectomy alone: Contraindicated!!! Further destabilizes an unstable spine, may lead to posttraumatic kyphosis In combination with stabilization may provide access to allow visualization and repair of dural tears

43 Methods of Decompression Posterolateral decompression Transpedicular or costotransversectomy Useful when anterior approach not a viable option Useful in lumbar spine w/ dural mobilization Indirect Reduction Canal cleared by spinal realignment Relies primarily on posterior annulus reducing retropulsed fragment Optimal time: immediate - 72 hrs.

44 Emergent: Timing of Surgery Progressive neurological deficit in an unstable fracture pattern Studies have shown no significant increase in morbidity with early surgery Subacute: Decreased edema, stable general condition, decreased blood loss, Spine team Late recovery common

45 Timing of Decompression? Early 1. Most animal SCI studies support early decompression 2. Intuition: remove pressure early = improved recovery Delayed 1. Clinically, early intervention has less support, its less convenient. 2. Fear of complications related to early surgery

46 Timing of Surgical Stabilization Benefits of early surgery : facilitates aggressive pulmonary toilet decreases risk of DVT/PE with mobilization prevents likelihood of decubitus ulcers facilitates earlier rehab Surgery should be delayed until: Hemodynamically/medically stabilized An experienced surgeon/ team is available

47 Indication for Early/Emergent Decompression Progressive neurologic deficit associated with canal compromise from retropulsed fragments or spinal mal-alignment (fx/dislocation)

48 Compression Fractures Anterior column injury Does not extend into posterior vertebral wall on CT With increasing severity, the likelihood of posterior lig complex injury increases. If PLC is disrupted --UNSTABLE (not a compression fracture)

49 Wedge Compression Fractures Hyper flexion or compressive failure Anterior column Stable injury

50 Compression Fractures Compression fractures rarely require surgery Surgery is indicated if PLC disrupted Relative indications for surgery single level lumbar VB height loss >50 % single level thoracic VB height loss >30 % combined multi-level height loss >50 % relative segmental or combined kyphosis >30 º

51 Compression Fractures Non-operative treatment TLSO or Jewitt extension bracing Frequent radiographic follow-up Deformities can progress Advantages: avoid surgical complications and muscle injury 2 to surgery Disadvantages: post-traumatic kyphosis

52 Compression Fractures Outcomes and Complications Most common sequelae is BACK PAIN does not correlate with severity of deformity (Young, 1993, Hazel, 1988) Lumbar worse than thoracic (Day, 1977)

53 Burst Fractures Definition: fracture extends into posterior vertebral wall May be stable or unstable

54 Unstable Burst Fractures (textbook definition ) Related to PLC integrity >30 º relative kyphosis Loss of vertebral body height > 50% MRI finding of disrupted PLC

55 Stable Burst Fractures Criteria (burst with intact PLC) <20-30 º kyphosis (controversial) <50% lumbar canal compromise <30% thoracic canal compromise TLSO/Jewitt brace (for comfort)

56 Stable Burst Fractures Radiographic follow-up to follow potential deformity progression Optional: Repeat CT to monitor canal resorption Same treatment principles as compression fracture

57 Burst Fractures Outcomes and Complications Anterior Approach Ileus (GI) after anterior approach Risk of large vessel damage Improved chances of bladder recovery with anterior decompression Without decompression: fragment resorption decreases canal compromise by 30% Non-op results similar to results of Op

58 Specific Thoracolumbar Injuries Compression fractures Burst fractures Flexion-distraction/Chance injury Fracture-dislocations

59 Fracture-Dislocations High-energy injuries Highest rate of SCI of all spinal fractures Thoracic--worst prognosis Rare non-operative management Unstable with multi-planar deformity---little residual stability

60 Flexion-Distraction Injury Due to distraction forces of middle and posterior columns Usually secondary to seat belt injuries Boney, purely soft tissue, mixed Visceral injuries common

61 Chance (Flexion-Distraction) Injury Seatbelt injury Trans-abdominal ecchymosis Common in children (seatbelt higher up) 0-30% neurologic injury Most common associated non-spinal injury: perforated viscus (pressure)

62 Chance Injury Injury often involves 3- columns Wide range of vertebral body involvement Center of rotation: variable PLC disrupted or posterior neural arch fractured transversely

63 Chance Fracture

64 Chance Fracture Variants Purely bone Best healing Part bony/part ligamentous Some healing Purely ligamentous/ trans-discal No healing

65 What type of fracture is this? What is the mechanism? Associated Injuries?

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67 RIGHT LEFT

68 Flexion-Distraction Injuries Boney Chance: stable in extension (TLSO) brace the fracture will heal Ligamentous injuries do not heal, require stabilization and fusion need to restore the disrupted posterior tension band

69 Surgical Approach Posterior approach Relies on intact ALL If burst component present, optimal treatment with pedicle screws (maintain anterior column length, don t over compress--- increase retropulsion )

70 Decompression? Spinal realignment often accomplished decompression prone positioning on OR table O.R.I.F. locked facets: open reduction by resection of articular processes

71 Posterior constructs provide stability after realignment Rarely require anterior decompression/ reconstruction

72 Fracture-Dislocations Outcome and Complications Severity of SCI --main predictor of outcome

73 Translational/ Rotational Injury Results from shearing failure of middle column Holdsworth coined slice fracture Most unstable!!! Highest incidence of neurologic deficit

74 Mrs. P.T. 43 woman High Speed MBA - learning to ride MD on scene - no motor and sensory function lower limbs

75 Mrs. P.T. Severe dysasthetic arm pain Neck pain T7 paraplegia Bilateral hemothoraces Right ACL disruption Left Wrist fracture

76 Examination Findings GCS 15/15 Tenderness upper thoracic and cervical spine Kyphus and hematoma upper thoracic spine Neurological examination complete paraplegia with sensory level T7

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82 Mr. R.H. 24 male Army parachutist Landed onto concrete surface during jump Immediate pain in back and wrist Pain into left thigh

83 Examination Findings GCS 15/15 Tenderness upper lumbar spine No hematoma / palpable defect in midline Neurological examination normal except for decreased sensation left L2 dermatome Deformed right wrist

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86 History 30 year old women fall down an escarpment

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91 SUMMARY History and Physical exam often ATLS Imaging X-rays CT/MRI Treatment Bracing Surgery Controversy exists regarding Treatment type, approach, timing of treatment

92 Thank You