Abstract
Introduction
Neurological affection in OPF depicts dynamic instability in the fractured vertebral body. Surgical treatment favors posterior instrumentation in most reports, while hinting toward anterior decompression in selected cases. Guidelines for radiology-based selection of surgical protocol is lacking in literature. We propose a radiological classification and results of surgical treatment of OPFs.
Study: Prospective, clinical case series (Level 3).
Material and Methods
50 consecutive patients (M: F 21:29, average age 69.8) were grouped into 5 radiological patterns. Average BMD was -2.7 (−1.8 to -3.4). Radiological assessment was X-rays, MRI and CT scan. 1. Burst Fracture with retropulsion (23). 2. Tri-columnar instability (13). 3. Circumferential stenosis (9). 4. Intra-vertebral instability post vertebroplasty (2). 5. Unstable disc adjacent to OPF (2). 6. Progressive deformity (1). Average duration of fracture was 2.3 months (0.5 – 6) and neuro-deficit was 0.98months (0.25- 3). Fracture distribution (53 OPF) was D5 (2), D7 (1), D10 (4), D11 (5), D12 (18), L1 (11), L2 (4), L3 (5), and L4 (3). Surgical Protocol was: Pattern 4: Only Posterior stabilization (PS); Pattern 2: PS and VP; Pattern 1: PS and Vertebroplasty (VP) in 17. Posterior decompression (PD) 6; Pattern 3: PS, PD, VP (9), Inter-body cage (4); Pattern 5: PS, TLIF; Pattern 6: PSO.
Result
Average follow-up was 2 years (2008–2014). 47 completed study. Average pre & post treatment and final kyphosis was 27.8 degrees (10- 62), 15.7 degrees and 20.9 (loss of correction 5.2) degrees. Average Pre & post procedure and 2 year VAS pain scores were 8.2, 3.5 and 5.2 respectively. The pre-op ASIA grades were B (4), C (13), D (27). Final ASIA grades were A (1), B (1), C (9), D (32), E (4). Fracture above fixation caused paraplegia in one patient that did not improve. Implant loosening was seen in 19 (40.42%) and 7 (12.76%) required revision. Proximal junctional kyphosis occurred in 2. Pattern 1–4, PS & VP provided stability and clinical improvement. PD was required in 10 (21.27%) only (Specific root decompression in 4). Inter-body cage was used in 6 (early part of series). Authors believe vertebroplasty restores anterior stability and cage should be carefully selected. Pattern 3 is seen with severe degenerative or inflammatory arthropathy. PD sufficed and anterior approach was never preferred. Pattern 5 has not been described in literature. In 2 cases, the disc adjacent to the fractured end plate herniated 3 months after the fracture pain had resolved. Authors hypothesize that impairment of nutrition and stability both contributed to herniation and is a complication of OPF. Pattern 6 was a progressive lumbar kyphosis due to L3 and L4 collapse leading to posterior element failure. Pattern 4 is persistent intra-vertebral instability after vertebroplasty. The posterior osteo-ligamentous complex remained normal. Neurological deficit occurred 6 weeks after vertebroplasty. In contrast Pattern 2 was a combination of Pattern 1 with posterior element injury.
Conclusion
Identifying radiological pattern helps understanding mechanism of injury and formulates a simplistic surgical protocol that alleviates pain and helps neurological recovery.