High-grade spondylolisthesis treated using a modified Bohlman technique: results among multiple surgeons

Area of Science:

• Spine surgery
• Orthopedic surgery
• Degenerative spine disease

Background:

• The optimal surgical management for high-grade spondylolisthesis is debated.
• Concerns exist regarding the original Bohlman technique, including graft fracture and kyphosis.
• Alternative fixation methods are needed to improve outcomes.

Purpose of the Study:

• To evaluate radiographic and surgical outcomes of high-grade spondylolisthesis treated with the Bohlman technique.
• To compare transsacral S-1 screws versus standard pedicle screw fixation.
• To assess the efficacy of modified Bohlman fusion for spondylolisthesis.

Main Methods:

• Retrospective review of 16 patients with high-grade spondylolisthesis.
• Comparison of transsacral versus standard pedicle screw fixation augmenting Bohlman fusion.
• Radiographic analysis of slip percent and angle, and evaluation of complications.

Main Results:

• Spanning pedicle screw fixation showed no nonunions, unlike isolated transsacral screws (2/6 revision rate).
• Significant improvements in slip percent (62% to 37%) and slip angle (18° to 8°) were observed.
• Fusion rate was 88% (14/16), with low rates of L-5 motor deficit.

Conclusions:

• The modified Bohlman technique with spanning instrumentation is effective for high-grade spondylolisthesis.
• This approach yields reproducible results with significant radiographic improvements.
• Fusion rates are high, and L-5 motor deficits are infrequent.