Prone Transpsoas (PTP) fusion is a minimally invasive surgical technique that utilizes a single-position lateral approach to access the anterior column of the lumbar spine. This approach has been employed to manage various lumbar spine conditions, including unilateral stenosis, deformities, and degenerative spondylolisthesis. The primary objective of this study is to evaluate the safety and efficacy of PTP fusion in treating degenerative lumbar conditions, including spondylolisthesis, and to assess its effectiveness in achieving spinal realignment.
A multi-centre, multi-surgeon cohort study was conducted with 204 patients who underwent PTP fusion. All participants provided informed written consent. Descriptive statistical analyses were employed to evaluate patient demographics, procedural metrics, and clinical and radiological outcomes.
The cohort consisted of 204 patients (108 females, 96 males), with a mean age of 72 years and a mean BMI of 28. A total of 282 interbody fusions were performed across the following levels: L1/2 (n = 16), L2/3 (n = 42), L3/4 (n = 89), and L4/5 (n = 135). The mean anaesthetic time was 170 minutes, with a total operative time of 115 minutes. The lateral operative time for anterior column fusion averaged 39 minutes, with a mean psoas retraction time of 14 minutes.
Radiological outcomes showed significant improvements in lumbar lordosis, increasing from 48°±13° pre-operatively to 53°±12° post-operatively (P < 0.001). Segmental lordosis (SL), anterior disc height (ADH), and posterior disc height (PDH) also improved significantly: SL increased from 8.6°±5.6° to 12.6°±5.3° (P < 0.001), ADH from 6.9 mm (±3.1) to 11.4 mm (±2.1, P < 0.001), and PDH from 3.8 mm (±1.7) to 5.6 mm (±2.0, P < 0.001).
In a subset analysis of 107 patients with spondylolisthesis, anterior column fusion was combined with posterior pedicle screw fixation to optimise spinal alignment. The average slip of 5.75 mm (±5.8 SD) had a statistically significant reduction in spondylolisthesis to 0.80 mm (±1.8 SD, P < 0.001).
No major vascular or visceral complications were observed in the cohort. Post-operative complications included four cases of psoas weakness lasting longer than three months, two surgical site infections, one psoas hematoma, two instances of periprosthetic malposition or fracture requiring reoperation, and one anterior longitudinal ligament release.
The prone transpsoas approach is a safe and effective technique for managing various degenerative lumbar spine conditions, including grade 1 spondylolisthesis. This study demonstrates significant post-operative improvements in spinal alignment, further supporting the utility of PTP fusion in treating lumbar spondylosis. These findings contribute to the expanding body of evidence regarding the safety and efficacy of this minimally invasive technique.