Treatment of unstable spinopelvic fractures: outcome of three surgical techniques-a retrospective single-center case series

L4 fixation is not necessary in L5-Iliac spinopelvic fixation after trauma, but coadjutant transilio-transsacral fixation is

INTRODUCTION

Spinopelvic dissociation (SPD) is a severe injury characterized by a discontinuity between the spine and the bony pelvis consisting of a bilateral longitudinal sacral fracture, most of the times through sacral neuroforamen, and a horizontal fracture, usually through the S1 or S2 body. The introduction of the concept of triangular osteosynthesis has shown to be an advance in the stability of spinopelvic fixation (SPF). However, a controversy exists as to whether the spinal fixation should reach up to L4 and, if so, it should be combined with transiliac-transsacral screws (TTS).

OBJECTIVE

The purpose of this study is to compare the biomechanical behavior in the laboratory of four different osteosynthesis constructs for SPD, including spinopelvic fixation of L5 versus L4 and L5; along with or without TTS in both cases.

MATERIAL AND METHODS

By means of a formerly described method by the authors, an unstable standardized H-type sacral fracture in twenty synthetic replicas of a male pelvis articulated to the lumbar spine, L1 to sacrum, (Model: 1300, SawbonesTM; Pacific Research Laboratories, Vashon, WA, USA), instrumented with four different techniques, were mechanically tested. We made 4 different constructs in 5 specimen samples for each construct. Groups: Group 1. Instrumentation of the L5-Iliac bones with TTS. Group 2. Instrumentation of the L4-L5-Iliac bones with TTS. Group 3. Instrumentation of L5-Iliac bones without TTS. Group 4: Instrumentation of L4-L5-Iliac bones without TTS.

RESULTS AND CONCLUSIONS

According to our results, it can be concluded that in SPD, better stability is obtained when proximal fixation is only up to L5, without including L4 (alternative hypothesis), the addition of transiliac-transsacral fixations is essential.

Operative Technique for Sacral Insufficiency Fractures Causing Spinopelvic Dissociation: A Case Report

CASE

We present a case of a 54-year-old man with atraumatic, U-type sacral insufficiency and L5 compression fractures leading to spinopelvic dissociation, inability to ambulate, and bowel/bladder compromise. The patient underwent L3-4 percutaneous pedicle screw fixation with bilateral iliac bolts and percutaneous iliosacral screw fixation. Postoperatively, the patient had return of bowel/bladder function and independent ambulation at 2.5 years.

CONCLUSION

Atraumatic spinopelvic dissociation is an underappreciated pathology in older patients. Here, we describe the result of our preferred treatment strategy, triangular osteosynthesis, to preserve function and independence. Despite optimal, prompt treatment, these injuries pose a difficult rehabilitation process for patients.