BACKGROUNDThe traditional lamina osteotomy replantation method is prone to nerve root injury and low back pain recurrence. Our team has proposed a modified approach that improves the osteotomy site and its fixation procedure. The aim of this study was to evaluate the clinical efficacy of traditional and modified lamina replantation methods in treating unstable lumbar disc herniation.

METHODSFrom March 2008 to August 2011, 124 patients with unstable lumbar disc herniation were enrolled and randomly divided into the following two groups according to random digital table: group A (traditional group) consisting of 61 patients who underwent traditional laminectomy replantation, and group B (modified group) consisting of 63 patients who underwent modified lamina replantation. Both surgeries were performed by the same surgeons. The two groups had no significant difference in gender, age, symptoms, time of onset and the prominent segment. Visual analogue scale (VAS), Oswertry disability index (ODI), and Japanese Orthopaedic Association (JOA) scores, operative time, blood loss, complication rate, radiographic healing rates, and low back pain recurrence rates were compared between the two groups.

RESULTSThere were 121 patients followed up for more than one year, and the follow-up rate was 97.6%. Nerve injury occurred in two patients (3.3%) in the modified group and 12 patients (20.0%) in the traditional group. Dural injury occurred in one patient (1.6%) in the modified group and seven patients (11.7%) in the traditional group. Pseudarthrosis occurred in two patients in the modified group and in 18 patients in the traditional group with 1-year fusion rates of 96.7% and 70.0%, respectively. Recurrence of lower back pain after one year was noted in three patients (4.9%) in the modified group, and in 15 (25.0%) in the traditional group. Leg pain recurrence was noted in one patient (1.6%) in the modified group and in three cases (5.0%) in the traditional group. The one-year healing rates of nerve injury, dural injury, replantation lamina and low back pain recurrence rates after one year were significantly different (P < 0.05) between the two groups. At two weeks, three months, six months and one year postoperatively, both groups had significant improvement in VAS, ODI, and JOA scores from their preoperative values (P < 0.05). No significant difference was detected between the short term postoperative scores between groups A and B (P > 0.05). However, a significant difference was found one year later (P < 0.05).

CONCLUSIONSCompared to the traditional approach, the modified technique for lamina replantation showed lower rates of dural and nerve damage, a higher lamina healing rate, a lower back pain recurrence rate, and better clinical scores. It is a safe and effective operation for lumbar spine surgery.