OBJECTIVETo explore the advantages and indications of the paraspinal approach by anatomical study and clinical application.

METHODSThe anatomical data and clinical practice of 27 cases were analyzed to explore the accurate approach between the paraspinal muscles and the structure of ambient tissues, as well as the results of clinical application of paraspinal approach. The operation time, blood loss, incision length, radiographic result (Cobb angle, height of anterior edge of the vertebrae) were compared with those in 24 cases treated by traditional approach.

RESULTSComplete exposure of the facets could be easily performed by identifying natural cleavage plane between the multifidus and longissimus muscles. The natural muscular cleavage was (1.47+/-0.23) cm lateral to the midline for females, and (1.64+/-0.35) cm for males at T(12) level. The distance was (3.3+/-0.6) cm lateral to the midline for females, and (3.7+/-1.0) cm for males at L(4) level. In paraspinal approach group, the operation time was (76.2+/-15.7) min, blood loss was (91.6+/-16.9) ml and incision length was (7.6+/-0.8) cm. In traditional approach group, the operation time was (121.4+/-19.6) min, blood loss was (218.7+/-32.3) ml and incision length was (17.4+/-2.1) cm. To compare paraspinal approach with traditional approach, the operation time, blood loss and incision length had statistical difference (P less than 0.05) and the radiographic result (Cobb angle, height of anterior edge of the vertebrae) had no statistical difference (P larger than 0.05).

CONCLUSIONSWhen the paraspinal approach is performed through natural cleavage plane between the multifidus and longissimus muscles, there are no wide muscular disinsertions, leaving the supraspinous and interspinous ligaments intact. The distance of natural cleavage to the midline is different at T(12) and L(4) planes. By this approach, the facet joints can be explored easily and completely, and a clear surgical field will be available for the placement of pedicle screws. As a minimally invasive approach, it can be widely used in thoracolumbar spine surgery.