What is involved in a posterior approach L2 (second lumbar) vertebra corpectomy or vertebrectomy?

Posterior Approach L2 Vertebral Corpectomy: Technical Overview and Outcomes

A posterior approach to L2 corpectomy is technically feasible and can achieve complete anterior column reconstruction through a single incision, though it requires transgression of large muscle groups and carries higher wound-related morbidity compared to anterior approaches. 1

Surgical Technique

Access and Exposure

• The posterior approach can be used for any spinal segment and provides access to the L2 vertebral body through a transpedicular or extracavitary corridor 1, 2
• The extracavitary approach allows circumferential decompression and anterior column reconstruction without requiring a separate anterior incision 3
• Patients are positioned prone on a radiolucent table to facilitate intraoperative imaging 3

Corpectomy Execution

• Complete vertebrectomy is performed through transpedicular bone removal, accessing the vertebral body by removing the pedicles and working anteriorly 3, 4
• The operative microscope may be useful to inspect the surgical bed and ensure complete resection 1
• Both unilateral and bilateral pedicle involvement can be addressed through this approach 3

Reconstruction Components

• Anterior column reconstruction is completed with an expandable titanium cage inserted in the collapsed position, then expanded in situ after implantation 3, 5, 4
• This technique allows reconstruction without sacrificing lumbar nerve roots 3
• Posterior instrumentation with pedicle screw fixation is performed through the same exposure, typically spanning 2 levels above and below the corpectomy 3, 5, 4
• Titanium constructs are preferred as they are biologically inert with ultrastructurally smooth surfaces that minimize organism adherence 2

Clinical Outcomes

Neurological Recovery

• Neurological improvement occurs in the majority of patients, with studies showing improvement in 67-72% of cases 5, 6
• No new neurological deficits occurred in a series of 34 consecutive patients 5
• One study reported iatrogenic nerve root traction injury in 1 of 21 patients (4.8%), though the patient remained ambulatory 3

Pain and Functional Outcomes

• Pain scores improve dramatically, with visual analog scale decreasing from 8.94/10 preoperatively to 2.62/10 postoperatively 5
• Sagittal deformity is significantly reduced (average 10.0 degrees correction, P = 0.013) 5
• The posterior approach demonstrates comparable clinical outcomes to anterior and combined approaches for thoracolumbar fractures 1

Operative Characteristics

Surgical Parameters

• Average estimated blood loss per level: 1,360 cc (range 200-2,500 cc) for extracavitary approach 3
• Blood loss is higher with posterior approach (2,486 ml) compared to anterior approach (1,172 ml) for thoracic vertebrectomies (P = 0.03) 6
• Average operative time: 5.3 hours per level (range 2.7-8.6 hours) 3
• Average postoperative stay: 4.7 days 3

Radiographic Stability

• No gross hardware fracture or pseudoarthrosis was observed at mean follow-up of 28.8 months in one series 4
• Minimal cage subsidence may occur in long-term follow-up (>60 months) but typically does not require intervention 3, 4
• Posterior instrumentation alone after corpectomy provides superior rigidity compared to anterior instrumentation alone in biomechanical studies 7

Complications and Morbidity

Wound-Related Issues

• Posterior approaches have significantly higher wound infection rates (26.7%) compared to anterior approaches (4.5%) (P = 0.03) 6
• Dorsal incisions are prone to poor wound healing, particularly in patients who remain recumbent postoperatively due to direct pressure on the wound 1, 2
• Overall complication rate: 14.3% in the largest extracavitary series 3

Systemic Complications

• Deep vein thrombosis occurs more frequently with posterior approach (15.6%) compared to anterior or combined approaches (0%) (P = 0.02) 6
• Pneumothorax risk is lowest with posterior approach (4.4%) compared to anterior or combined approaches (P < 0.0001) 6
• No chest tubes are required with pure posterior approach 3

Recovery Considerations

• Posterior approaches require longer recovery periods due to extensive paraspinal muscle dissection 1, 2
• This is the primary disadvantage compared to anterior retroperitoneal approaches, which patients typically tolerate extremely well 1

Critical Technical Limitations

Anterior Access Constraints

• Decompression of ventral epidural pathology via posterior approach alone must be performed with extreme caution in the cervical or thoracic spine 1, 2
• However, at the L2 level, transpedicular corpectomy provides adequate access to the anterior column and ventral thecal sac 3, 4

Biomechanical Considerations

• Laminectomy alone rarely causes destabilization unless substantial vertebral body destruction coexists 1, 2
• After corpectomy, posterior instrumentation alone provides adequate stability for L2 reconstruction 4
• Combined anterior-posterior instrumentation provides superior rigidity but has higher complication rates compared to posterior-only approaches 1, 7

Intraoperative Monitoring

• Intraoperative electrophysiological monitoring (evoked and spontaneous EMG) during pedicle screw placement is recommended, with 100% sensitivity and 91-100% negative predictive value for detecting screw malposition 2

Common Pitfalls to Avoid

• Do not underestimate blood loss—ensure adequate blood product availability and consider cell saver technology 6
• Avoid inadequate posterior instrumentation—biomechanical studies show anterior instrumentation alone after corpectomy is insufficient 7
• Recognize the prolonged recovery time associated with extensive muscle dissection when counseling patients 1, 2
• Implement aggressive DVT prophylaxis given the 15.6% thrombosis rate 6
• Ensure meticulous wound closure and postoperative wound care to minimize the 26.7% infection risk 6

budget:token_budget Tokens used this turn: 5506 Tokens remaining: 194494