Which muscles are spared in the interlaminar (interment) approach in endoscopic spine surgery?

Muscles Spared in Interlaminar Approach for Endoscopic Spine Surgery

The interlaminar approach in endoscopic spine surgery primarily preserves the multifidus and paraspinal muscles by avoiding extensive muscle stripping and retraction, resulting in significantly less muscle atrophy compared to traditional midline approaches. 1

Anatomical Preservation in Interlaminar Approach

• The interlaminar approach allows access to the spinal canal while preserving the attachment of paravertebral muscles to the spinous process, minimizing muscle damage 2
• Studies show that the degree of postoperative paraspinal muscle atrophy is significantly less when using approaches that avoid extensive muscle stripping compared to traditional midline approaches (-4.8% vs -20.7%, respectively) 1
• The technique specifically preserves the multifidus muscle, which is crucial for spinal stability and function 2

Technical Aspects of Muscle Preservation

• In the interlaminar approach, the surgeon accesses the spinal canal through the interlaminar space without extensive detachment of the paraspinal muscles from their bony attachments 3
• This approach requires less manipulation and retraction of the paraspinal muscles compared to traditional approaches, which contributes to muscle preservation 1
• The technique allows for both ipsilateral and contralateral decompression while maintaining minimal muscle disruption 4

Advantages of Muscle Preservation

• Preservation of the paraspinal muscles leads to less postoperative pain and faster recovery 5
• MRI studies one year after surgery show no significant difference in T2 signal intensity of the multifidus muscle between the approach and non-approach sides, indicating minimal muscle damage 2
• The muscle-sparing nature of this approach may contribute to better long-term functional outcomes and decreased risk of failed back surgery syndrome 1

Comparison with Other Approaches

• Traditional midline approaches require stripping the paravertebral muscles from the spinous process, resulting in greater muscle damage and atrophy 1
• The posterior approach typically requires transgression of large muscle groups, leading to longer recovery times and higher risk of poor wound healing 6
• Posterior approaches are typically more painful due to muscle dissection and have a higher risk of wound complications 6

Clinical Implications

• The muscle-sparing benefit of the interlaminar approach aligns with current trends toward minimally invasive spine surgery techniques that aim to reduce surgical morbidity 3
• Preservation of the paraspinal muscles may help maintain spinal stability and reduce the risk of adjacent segment disease 1
• The interlaminar approach allows for extensive foraminal and extraforaminal decompression without causing neural retraction while maintaining the stability of the operated level 5

The interlaminar approach represents an important advancement in endoscopic spine surgery by allowing adequate decompression while minimizing damage to the critical stabilizing musculature of the spine, potentially leading to improved patient outcomes.