Evaluation of the stress distribution change at the adjacent facet joints after lumbar fusion surgery: A biomechanical study

Abstract

Spinal fusion surgery has been widely applied in clinical treatment, and the spinal fusion rate has improved markedly. However, its postoperative complications, especially adjacent segment degeneration, have increasingly attracted the attention of spinal surgeons. The most common pathological condition at adjacent segments is hypertrophic degenerative arthritis of the facet joint. To study the stress distribution changes at the adjacent facet joint after lumbar fusion with pedicle screw fixation, human cadaver lumbar spines were used in the present study, and electrical resistance strain gauges were attached on L1-L4 articular processes parallel or perpendicular to the articular surface of facet joints. Subsequently, electrical resistance strain gauge data were measured using anYJ-33 static resistance strain indicator with three types of models: the intact model, the laminectomy model, and the fusion model with pedicle screw fixation. The strain changes in the measurement sites indirectly reflect the stress changes. Significant differences in strain were observed between the normal and laminectomy state at all facet joints. Significant differences in strain were observed between the normal and the pedicle screw fixation fusion state at the L1/2 and L3/4 facet joints. The increased stress on the facet joints after lumbar fusion with pedicle screw fixation may be the cause of adjacent segment degeneration.

Preserving Posterior Complex Can Prevent Adjacent Segment Disease following Posterior Lumbar Interbody Fusion Surgeries: A Finite Element Analysis

“…Several authors reported that the changes in load sharing among ligaments would alter the normal physiological and mechanical environments of ligaments, leading to ligament failure and hypertrophy [24, 25]. Moreover, the increase in ligaments forces were likely relevant to the invocation of pain and prone to cause chronic soft tissue injury, facet joint degeneration as well as hypertrophy of the LF, and thereby cause the ASD [5, 23, 24, 26]. …”

The primary stability of different implants for intra-articular calcaneal fractures: an in vitro study

“…Secondly, the same calcaneus model was consecutively tested under intact and fracture conditions due to the limitation of specimen numbers. However, this procedure was common in biomechanical studies [ 16 , 25 , 27 ], and the simulated physiological loading would not bring much damage to calcaneus structures. Thirdly, the surrounding soft tissues were not considered in this study because the musculature was not active in the cadaveric samples.…”

Biomechanical analysis of single-level interbody fusion with different internal fixation rod materials: a finite element analysis

“…On the other hand, biomechanical studies have shown that fusion at one or two levels can increase the stress at adjacent segments [7][8][9]. Studies [9,10] have also indicated that the fusion surgery might increase the stress at facet joints and increase segmental mobility and intradiscal pressure at adjacent levels.…”