Irreducible L5/S1 Spondyloptosis in Over 20 Years After Neglected Trauma Treated with Modified Grob’s Technique – Case Report

Introduction

Spondyloptosis, a pathological condition characterized by the complete slip of an overlaying vertebral body off the underlying one, is commonly classified as grade 5 spondylolisthesis with a slip exceeding 100% according to the classification introduced by H.W. Myerding in 1938.¹ The most prevalent locations for spondyloptosis are the L5/S1 and L4/L5 levels.^2,3 This condition leads to a state of extreme instability within the affected vertebral segment, accompanied by associated disorders of the vertebral canal. Notably, the manifestation of symptoms associated with root or spine compression varies depending on the specific level of slippage. Spondyloptosis is typically the result of high-energy trauma and necessitates urgent surgical intervention, as delay in treatment may further exacerbate the condition.^4–8 It is uncommon for patients to present to a spinal surgery unit several decades after the initial traumatic event. In this context, we present a noteworthy case report of a patient who experienced sacrolumbar spine trauma over two decades ago and subsequently underwent surgical intervention involving spinal canal decompression and posterior lumbosacral fusion utilizing a modified Grob’s method.

Report of the Case

A 62-year-old individual with obesity (BMI 37.1 kg/m2) was admitted to the authors’ spinal surgery unit due to the presence of severe pain in the lumbosacral region, which radiated to the lower extremities (Visual Analog Scale [VAS] score of 6 out of 10). Additionally, the patient experienced severe neurogenic claudication (14 points on the N-CLASS scale⁹) and exhibited weakness in the lower limbs (MRC scale: 4). No reports of bowel or bladder control loss were noted. The Oswestry Disability Index (ODI) score was 48%, indicating a state of severe disability.¹⁰

The magnetic resonance imaging (MRI) examination performed on the patient revealed findings consistent with complete spondylolisthesis (spondyloptosis) at the L5/S1 level. The MRI showed distortion of the vertebral bodies, with the L5 vertebral body displaced anteriorly to the S1 vertebral body. Additionally, critical stenosis of the spinal canal and intervertebral foramina was observed. (Figure 1) Prior to the surgery, a preoperative computed tomography (CT) scan was conducted, providing further information. In addition to the previously mentioned findings, the CT scan revealed a significant degree of bone fusion (union) in the L5/S1 region. Furthermore, the transverse dimension of the dural sac at the L4/L5 level was measured to be 15×9 [mm] (Figure 2).

Figure 1 Preoperative MRI - T2 TSE: (A) – midline sagittal plane, (B) – plane tangential to the L3/L4 disc (marked with the red line in the (A)).

Figure 2 Preoperative computed tomography scan: (A) – axial plane at the level marked with the red line in the (B), (B) – midline sagittal plane.

The surgical intervention consisted of decompression of the dural sac through laminectomy at the L3-S1 levels and stabilization of L3, L4, and L5-S1. Transpedicular screws were routinely inserted at the L3 and L4 levels. However, due to the significant bone fusion between L5 and S1, which hindered the reduction of spondyloptosis at this level, transpedicular screws were inserted using Grob’s technique, passing through the fused L5 and S1 vertebrae. Following stabilization, spinal canal decompression was performed, and the screws were connected to a connecting rod for further support and stability.

The postoperative course was uneventful, without any complications. A CT scan conducted 24 hours after the surgery confirmed the accurate positioning and secure anchorage of the screws. This imaging assessment provided reassurance regarding the stability and integrity of the surgical construct (Figure 3).

Figure 3 The 3D render of CT scan performed 24h after the surgery.

To enhance the comprehensibility of the case report, we compiled tomographic images that illustrate the placement of the screws. By consolidating these images, we aimed to provide a clearer visual representation of the precise positioning and alignment of the screws within the spinal structure (Figure 4).

Figure 4 Combined tomographic images showing screw placement.

Within 24 hours of the procedure, the patient regained the ability to walk. The previously experienced weakness in the lower extremities and neurogenic claudication were resolved. Following a favorable recovery, the patient was discharged in good overall condition after 72 hours. A digital radiograph obtained four weeks post-surgery revealed the accurate positioning of the screws, indicating successful alignment and stability. (Figure 5) At the four-month postoperative assessment, the patient’s Oswestry Disability Index (ODI) improved to 34%, indicating a significant reduction in disability. Prior to the surgery, the patient experienced nighttime pain disturbances, but after the procedure, he achieved uninterrupted sleep. The patient’s mobility has notably improved, enabling him to walk distances of up to 4 km without significant difficulties. However, he does report occasional paresthesias in his toes. Overall, the patient’s functional outcomes have significantly improved, demonstrating the positive impact of the surgical intervention.

Figure 5 Postoperative radiological image of the lumbosacral section obtained 1 month after the surgery.

Discussion

Spondyloptosis is a highly uncommon condition characterized by the complete displacement of a vertebral body in relation to the underlying vertebra. According to the classification introduced by Henry Meyerding, it can be classified as grade V spondylolisthesis, indicating a displacement of more than 100%. This severe form of spondylolisthesis involves the complete anterior translation of the affected vertebral body, resulting in significant instability and functional impairment. The rarity of this condition underscores its exceptional nature within the spectrum of spinal disorders.¹ Spondyloptosis manifests with various symptoms, including lower back pain, sciatica, neurogenic claudication resulting from spinal canal stenosis, compression of nerve roots leading to motor weakness, impaired or abolished reflexes, sensory disturbances, as well as sphincter dysfunction symptoms such as urinary and fecal incontinence.^11–14

While there have been numerous studies focusing on the pathomechanism and management of spondylolisthesis, the management of spondyloptosis, specifically, remains a challenge due to its rarity.^{11,12,15–18} Spondyloptosis is a condition that typically arises from high-energy trauma and is characterized by complete vertebral slippage. Despite the availability of literature on spondylolisthesis and its treatment modalities, there are no clear guidelines specifically tailored for spondyloptosis management. This further highlights the exceptional nature of this condition.^5–7,19 In our presented case report, the situation is particularly unusual as the patient experienced an injury, resulting from a fall, more than two decades prior to the onset of symptoms. During that time, the patient neglected to seek a diagnosis and treatment due to minor ailments. It is worth noting that complete vertebral slippage most commonly occurs at the lumbosacral level, with less frequent involvement of the lumbar region.²⁰

In the case we presented, the patient experienced severe low back pain that radiated to the lower limbs, along with weakness in the lower extremities and neurogenic claudication, which manifested after approximately 100 steps. Based on our assessment, these complaints were attributed to the stenosis of the spinal canal and intervertebral foramen at the L3, L4, L5, and S1 levels as observed in the imaging studies. These symptoms had a substantial negative impact on the patient’s quality of life.

The management of spondyloptosis typically necessitates surgical intervention involving decompression, reduction, and stabilization techniques.¹⁵ In our presented case, the spinal canal was decompressed through laminectomies performed at the L3-S1 vertebrae levels, followed by transpedicular stabilization at those segments. The routine insertion of polyaxial screws at the L3 and L4 levels was accompanied by the utilization of Grob’s direct pediculo-body fixation technique for stabilization at the L5-S1 level.²¹

It should be noted that the chosen technique may appear subject to debate when compared to methodologies described by other researchers. Nevertheless, none of the techniques reported in the literature completely addressed the requirements of our specific case. The Gaines and Nichols method, involving a two-stage reduction of spondyloptosis with anterior vertebrectomy at the L5 level during the initial stage and subsequent reduction and stabilization from L4 to S1 during the second stage, is acknowledged for its effectiveness.^13,22 However, this method exerts a significant toll on the patient’s overall condition and is predominantly intended for younger individuals - Gaines described his method on patients whose average age was 22 years. In our case, considering the patient’s age (62 years), high body mass index (37.1 kg/m2), and comorbidities, the risks associated with the anterior approach outweighed the potential benefits.

An alternative technique under consideration was sacral dome osteotomy, a posterior approach involving the removal of a fragment of the sacrum adjacent to the inferior terminal lamina of the L5 vertebra prior to reducing L5 over S1.²³ This technique has demonstrated efficacy according to previous reports.^15,18,24 Regrettably, we were unable to utilize this approach in our case due to extensive bony fusion between L5 and S1, likely resulting from detachment of the proximal part of the S1 shaft. This finding aligns with observations made by other investigators.¹⁴

The Grob technique of direct pediculo-body fixation, which we employed, represents an effective treatment option for advanced spondylolisthesis at the L5-S1 level.²¹ In Grob et al study, patients undergoing this technique reported experiencing neurogenic claudication and pain, with some individuals manifesting symptoms of radiculopathy. However, no postoperative neurological deficits were detected, and symptoms resolved in all treated patients. Notably, the mean age of the study participants was 54 years (ranging from 35 to 77 years), and the mean intraoperative blood loss was relatively low, with an average of 360 mL (ranging from 100 to 800 mL)²¹ In contrast, alternative techniques described in the literature primarily targeted much younger patient populations (approximately 22 years of age)^13,14,22,25 and were associated with higher blood loss (approximately 2 liters).^23,26,27 Authors combined In our case, we combined Grob’s method with dural sac decompression and transpedicular stabilization at the L3-L5S1 levels. Although this approach entails a higher risk of pseudarthrosis compared to stabilization with reduction, the procedure exhibited fewer intra- and postoperative complications and appeared to be a safer and more suitable choice for our patient.¹⁵

Following the surgical intervention, the patient was able to ambulate 24 hours postoperatively, demonstrating a notable improvement in gait. Additionally, the previously experienced neurogenic claudication completely resolved, and there was a notable increase in lower limb strength. The patient’s pain levels, as assessed using the Numeric Rating Scale (NRS), decreased from 6 to 2 points, indicating a substantial reduction in pain intensity. Subsequent diagnostic imaging confirmed the satisfactory placement of the screws. Remarkably, within a span of two months after the surgery, the patient fully regained functional capacity.

Conclusions

Based on our findings and experience, we firmly assert that the utilization of the Grob’s technique in conjunction with decompression and stabilization represents an efficacious and secure approach for managing spondyloptosis in older individuals. The combined procedure provides a comprehensive treatment strategy that addresses the underlying pathology, promotes spinal stability, and alleviates associated symptoms. By employing this approach, we have witnessed positive outcomes in terms of clinical improvement, functional recovery, and postoperative complications. Consequently, we advocate for the consideration of this combined technique as a viable option for the management of spondyloptosis in the geriatric population.