Anatomic Considerations of Intervertebral Disc Perspective in Lumbar Posterolateral Approach via Kambin's Triangle: Cadaveric Study

Abstract

Study DesignAnatomical study.PurposeTo evaluate the anatomy of intervertebral disc (IVD) area in the triangular working zone of the lumbar spine based on cadaveric measurements.Overview of LiteratureThe posterolateral percutaneous approach to the lumbar spine has been widely used as a minimally invasive spinal surgery. However, to our knowledge, the actual perspective of disc boundaries and areas through posterolateral endoscopic approach are not well defined.MethodsNinety-six measurements for areas and dimensions of IVD in Kambin's triangle on bilateral sides of L1–S1 in 5 fresh human cadavers were studied.ResultsThe trapezoidal IVD area (mean±standard deviation) for true working space was 63.65±14.70 mm2 at L1–2, 70.79±21.88 mm2 at L2–3, 99.03±15.83 mm2 at L3–4, 116.22±20.93 mm2 at L4–5, and 92.18±23.63 mm2 at L5–S1. The average dimension of calculated largest ellipsoidal cannula that could be placed in IVD area was 5.83×11.02 mm at L1–2, 6.97×10.78 mm at L2–3, 9.30×10.67 mm at L3–4, 8.84×13.15 mm at L4–5, and 6.61×14.07 mm at L5–S1.ConclusionsThe trapezoidal perspective of working zone of IVD in Kambin's triangle is important and limited. This should be taken into consideration when developing the tools and instruments for posterolateral endoscopic lumbar spine surgery.

Evaluation of the Lumbar Safety Triangle Through Magnetic Resonance Imaging

“…Lertudomphonwanit et al, 20 in a 2016 anatomical study of cadavers, demonstrate and suggest that the true work zone would be trapezoidal instead of the typical right angle triangle. 20,21 These researchers consider the disc height to be the limit of the medial height of the trapezoid. They also describe the trapezoidal area as varying by the level studied, which is in agreement with our reports.…”

“…It is understood from their description that the dorsal root ganglion would be inside the boundaries of the trapezoid, which would increase the chance of surgical complications. 20 The use of MRI as a preoperative evaluation tool in patients undergoing minimally invasive procedures demonstrates excellent detection of nerve anatomy and its relationships, 22 being able to suppress the vascular and/or fat signal to create selective images. 23 There may be changes in the anatomical relationships with the use of cadavers to study the triangular safety zone, since the tension within the tissues is reduced, particularly the thecal sac and the nerve root.…”

Transforaminal Percutaneous Endoscopic Lumbar Diskectomy for Downmigrated Disk Herniations: Lever-Up, Rotate, and Tilt Technique

“…Consequently, complete removal of the fragments became more likely with the use of larger size forceps and tools. 16,[21][22][23][24] Migration of herniated fragments is not uncommon. If the herniated fragment breaches the PLL and moves into the epidural space, it migrates in an up or down route in 35 to 72% of the cases.…”

Kambin's triangle and the position of the dorsal nerve root in the lumbar neural foramen

“…Thai (Lertudomphonwanit et al, 2016) population groups. Table 5 provides an overview of measurements from the current study and compares them to those from other population groups used in previous studies.…”