Degenerative lumbar spinal stenosis with osteoporotic vertebral fracture involving endplate: a retrospective study

Abstract

Objective

Degenerative lumbar spinal stenosis (LSS) accompanied by osteoporotic vertebral fractures (OVFs) involving the endplate is relatively uncommon and presents therapeutic challenges. This study aims to evaluate the clinical outcomes of surgical treatment in such cases.

Methods

A retrospective analysis was conducted on nine patients diagnosed with LSS and endplate-involved OVFs who underwent surgery at Ruijin Hospital between July 2015 and December 2022. Patients received either decompression with kyphoplasty or fusion with kyphoplasty. All patients were followed for a minimum of 12 months. Clinical outcomes were assessed using the Visual Analog Scale (VAS) and Japanese Orthopaedic Association (JOA) scores. Radiographic evaluations, including X-rays and CT scans, were used to assess implant stability, cage subsidence, and fusion status.

Results

The study included 1 male and 8 female patients, aged 72 to 81 years (mean: 76.3 ± 5.2 years). Two patients underwent decompression and kyphoplasty, six underwent fusion and kyphoplasty, and one patient received posterolateral fusion and kyphoplasty due to an enlarged disc space and cage instability. Significant postoperative improvements in VAS and JOA scores were observed and maintained throughout the follow-up period. Radiological follow-up exceeding 12 months revealed no intervertebral height loss or segmental instability in patients who underwent decompression and kyphoplasty. All patients in the fusion group achieved successful fusion without notable complications such as implant loosening or cage subsidence. The patient who underwent posterolateral fusion also experienced no complications, including screw loosening, vertebral height loss, or hardware failure.

Conclusion

Degenerative LSS combined with OVF involving the endplate is a complex clinical condition. Both decompression with kyphoplasty and fusion with kyphoplasty are effective surgical strategies, providing significant and sustained clinical improvement.

Introduction

Lumbar spinal stenosis (LSS) is a condition characterized by the narrowing of the spinal canal, leading to compression of the nerve roots and dura mater, and resulting in neurological symptoms. Degenerative LSS, which predominantly affects older adults, is typically caused by degeneration of the facet joints, hypertrophy of the ligamentum flavum, disc herniation, and loss of intervertebral disc height [1]. The most common clinical manifestation is intermittent claudication, while severe cases may involve urinary and bowel dysfunction as well as sexual disturbances. When conservative treatments fail, surgical intervention becomes necessary. Laminotomy and decompression are commonly employed techniques. However, when extensive decompression compromises spinal stability, or if segmental instability is identified preoperatively, fusion is often required in addition to decompression [2].

Degenerative LSS frequently occurs in elderly individuals who are also prone to osteoporosis. In some cases, these patients present with both LSS and osteoporotic vertebral fractures (OVFs), a condition referred to as LSS with OVF. These patients typically experience both lower back pain and neurological symptoms in the lower extremities. However, the severity of back pain varies widely: some individuals report severe pain, others only mild discomfort, and some experience minimal or no pain after conservative management [3]. Similarly, lower extremity symptoms are not always prominent prior to the fracture. In many cases, symptoms of LSS become apparent or rapidly worsen following a traumatic event. Unlike acute burst fractures, where early neurological deficits often result from direct bone fragment compression, patients with LSS and OVF typically do not exhibit obvious intracanal bone fragments on CT imaging and may not have immediate neurological deficits after trauma. Over time, however, these patients may develop progressive radiating pain in the lower limbs. This may be attributed to lumbar foraminal stenosis or redundant ligamentum flavum caused by vertebral height loss, as well as nerve root irritation due to fracture-related microinstability [4–6]. This progression differs from the delayed neurological dysfunction observed in stage III Kummell’s disease, which is usually driven by progressive kyphosis and gross spinal instability [7–9]. Notably, patients with LSS and OVF may lack both severe kyphotic deformity and significant vertebral height loss, despite having compression fractures.

Surgical treatment for LSS combined with OVF remains controversial. Various strategies—including posterior-only, anterior-only, and combined anterior-posterior approaches—have been reported, as well as diverse techniques such as decompression alone, instrumentation alone, or decompression combined with fusion. These approaches differ in terms of surgical indications, invasiveness, and clinical efficacy. Osteoporosis further complicates management by reducing the strength of internal fixation, increasing the risk of cage subsidence, and potentially lowering fusion rates [10]. In some cases, osteoporotic fractures involve the endplate, making interbody fusion more technically challenging. Endplate disruption increases the risk of cage subsidence or migration and may result in lower fusion rates or even require revision surgery [11, 12]. In this study, we report the clinical outcomes of a series of patients with degenerative lumbar spinal stenosis combined with endplate-involved osteoporotic vertebral fractures who underwent surgical treatment.

Method

This retrospective study analyzed nine patients with degenerative lumbar spinal stenosis (LSS) combined with osteoporotic vertebral fractures (OVFs) involving the endplates who were treated at our hospital between July 2015 and December 2022. The cohort included one male and eight female patients, with ages ranging from 72 to 81 years (mean: 76.3 ± 5.2 years). All patients underwent comprehensive preoperative assessments, including a detailed medical history, physical examination, standard radiographs (anteroposterior, lateral, and dynamic flexion-extension views), bone mineral density testing, three-dimensional computed tomography (CT), and magnetic resonance imaging (MRI). The diagnosis of degenerative LSS combined with endplate-involved OVF was confirmed based on these findings. Surgical intervention was performed in patients who failed to respond to standardized conservative treatment for at least six weeks. The study was approved by the Ethics Committee of Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, and informed consent was obtained from all participants.

Inclusion and exclusion criteria

Inclusion criteria were as follows: (1) typical clinical symptoms of lumbar spinal stenosis; (2) radiographic confirmation of lumbar spinal stenosis combined with osteoporotic vertebral fractures involving the endplates, based on X-rays, CT scans, MRI, and bone mineral density testing, consistent with clinical presentation; (3) failure to respond to at least 6 weeks of conservative treatment; (4) complete clinical and radiological data available; (5) endplate fractures located at the intervertebral disc level corresponding to the symptomatic segment. Exclusion criteria were as follows: (1) history of previous lumbar spine surgery with recurrence; (2) presence of spinal deformities, infections, or tumors; (3) coagulation disorders or bleeding tendency; (4) psychiatric disorders, refusal to participate, or poor compliance with follow-up.

Preoperative treatment

All patients received at least six weeks of standardized conservative treatment following diagnosis. The treatment protocol included bed rest, brace support, non-steroidal anti-inflammatory drugs (NSAIDs), dehydrating agents, neurotrophic medications, and selective nerve root blocks. In addition, all patients received systemic anti-osteoporotic therapy, which consisted of zoledronic acid, denosumab, or teriparatide, combined with vitamin D and calcium supplementation.

Surgical technique

The preferred surgical strategy for all patients was decompression of the affected spinal segment combined with kyphoplasty of the fractured vertebra [13]. In cases with preoperative segmental instability, or when the decompression required an extensive laminectomy that could compromise stability, decompression with fusion was performed. Unilateral or bilateral decompression was selected based on the patient’s clinical symptoms. Patients with unilateral lower limb symptoms underwent unilateral decompression, while those with bilateral symptoms or severe stenosis underwent unilateral approach bilateral decompression. For fusion procedures, short-segment fixation was adopted to minimize surgical trauma, reduce the risk of adjacent segment degeneration, and preserve spinal mobility. Kyphoplasty was performed at the fractured vertebral level using pedicle screw augmentation to restore vertebral height and stabilize the fracture. The adjacent vertebrae were also instrumented with pedicle screws to enhance fixation strength and increase resistance to screw pullout. In cases where the intervertebral space was excessively enlarged and the largest available cage could not achieve adequate stability, posterolateral fusion was performed instead of interbody fusion.

Surgical procedure A: decompression and kyphoplasty

After induction of general anesthesia, the patient was placed in the prone position on a four-point support frame. A posterior midline incision was made, and the skin, subcutaneous tissue, and deep fascia were sequentially dissected. The paraspinal muscles were detached bilaterally along the spinous processes and laminae until the lateral borders of the facet joints were exposed. Laminotomy was performed in a distal-to-proximal direction, involving partial removal of the lamina and the inferior articular process. The hypertrophied ligamentum flavum was excised, followed by lateral recess and foraminal decompression to fully release the dura mater and affected nerve roots. The annulus fibrosus was incised, and the herniated nucleus pulposus was removed to ensure thorough neural decompression. Under C-arm fluoroscopic guidance, bilateral pedicle punctures were performed at the fractured vertebral level. Working channels were established, followed by balloon inflation and injection of polymethylmethacrylate (PMMA) bone cement. The surgical field was thoroughly irrigated, hemostasis was achieved, and a drainage tube was placed before wound closure.

Surgical procedure B: fusion and kyphoplasty

After induction of general anesthesia, the patient was placed in the prone position. A posterior midline incision was made, and the paraspinal muscles were dissected to expose the facet joints. Bilateral pedicle screws were first inserted for augmentation. At the fractured vertebral level, the screws were temporarily removed to allow establishment of working channels, followed by balloon inflation and injection of polymethylmethacrylate (PMMA) bone cement (2–3 mL). The screws were then reinserted. An additional 1–2 mL of bone cement was injected into the adjacent vertebrae via the augmented pedicle screws. A laminotomy was performed up to the isthmus. The isthmus was osteotomized, and the inferior articular processes were resected. Lateral recess and foraminal decompression were performed by removing the inner margin and tip of the superior articular process. Hypertrophied ligamentum flavum and epidural vessels were excised, and the dura mater and nerve roots were fully decompressed. The annulus fibrosus was incised, and the herniated nucleus pulposus was removed. The cartilaginous endplates were carefully curetted to expose the bone grafting surface. Autologous bone harvested during decompression was packed into the anterior intervertebral space. An appropriately sized interbody fusion cage, filled with autogenous bone, was inserted according to preoperative measurements and intraoperative evaluation. After confirming the position of the dura mater and nerve roots, bilateral rods and caps were installed and secured. The final positioning of the screws and cage was confirmed with fluoroscopy. The surgical site was irrigated, hemostasis was achieved, and a drainage tube was placed prior to wound closure.

Postoperative management

Following surgery, patients were advised to remain on bed rest with moderate straight leg elevation and to perform lumbar muscle strengthening exercises. The drainage tube was removed once the drainage volume decreased to less than 50 mL within 24 h, typically 2 to 3 days postoperatively. Patients were then encouraged to begin ambulation with brace support. Patients were permitted to fully resume daily activities after three months. Heavy physical labor was restricted until interbody fusion was confirmed by computed tomography (CT) or at least 12 months after surgery. Standard postoperative care, including dehydration management, neurotrophic therapy, and analgesia, was initiated immediately after surgery and continued as indicated. Systematic anti-osteoporotic treatment, consisting of zoledronic acid, denosumab, or teriparatide combined with vitamin D and calcium supplementation, was also administered.

Follow-up indicators

All patients were followed up for a minimum of 12 months postoperatively. Clinical assessments included the Visual Analog Scale (VAS) for pain evaluation and the Japanese Orthopaedic Association (JOA) score for functional status. Radiological evaluations, including X-rays and computed tomography (CT) scans, were performed to assess fixation-related parameters such as implant loosening, cage subsidence, and fusion status.

Statistical analysis

Data analysis was performed using GraphPad Prism version 8. Continuous variables are expressed as mean ± standard deviation and were compared using Student’s t-test. Categorical variables were analyzed using the chi-square test. A p-value less than 0.05 was considered statistically significant.

Results

A total of nine patients with lumbar spinal stenosis and osteoporotic vertebral fractures involving the endplates were included, comprising one male and eight females. The patients’ ages ranged from 72 to 81 years, with a mean age of 76.3 ± 5.2 years. Nine spinal segments were affected, with eight cases at the L4/5 level and one case at L3/4. Decompression combined with kyphoplasty was performed in two cases, while fusion combined with kyphoplasty was performed in seven cases (Fig. 1). Among the fusion group, interbody cages were successfully implanted in six patients. In one patient, due to an excessively large intervertebral space causing instability of the largest available fusion cage, the procedure was modified intraoperatively to posterior lateral fusion.

Fig. 1.

A case of degenerative lumbar spinal stenosis with osteoporotic vertebral fracture involving endplate treated with fusion combined with kyphoplasty A 67-year-old male with L4/5 spinal stenosis and L5 OVCF (involving the upper endplate). The patient underwent decompression and interbody fusion of L4/5, together with kyphoplasty of L5 and cement augmentation of L4. Specially, the spread of the cement in L5 was dissatisfied because of the leakage at an early time. But fortunately, the pre-operative lower back pain was improved significantly after conservative treatment, and the internal fixation is useful enough for the treatment of upper endplate and anterior upper margin fractures. Three months post-surgery, the lower back pain VAS score was 1, and the leg pain VAS score was 1. And the X ray examination demonstrated significant intervertebral bony union formation at 12 months post-surgery

All nine patients completed follow-up, with a duration ranging from 13 to 37 months (mean, 24.3 months). Postoperative Visual Analog Scale (VAS) and Japanese Orthopaedic Association (JOA) scores improved significantly compared to preoperative values (both p < 0.001), and these improvements were maintained through the final follow-up.

Radiological follow-up exceeding 12 months was conducted for all patients. Those who underwent decompression and kyphoplasty showed no significant loss of intervertebral height or evidence of segmental instability. All patients treated with fusion and kyphoplasty achieved successful interbody fusion, without notable complications such as implant loosening or cage subsidence. In the patient who received posterolateral fusion combined with kyphoplasty, no significant complications—including screw loosening, vertebral height loss, or rod and screw breakage—were observed at the 16-month final follow-up.

Discussion

Osteoporosis is a major global public health concern, and an increasing number of patients requiring spinal surgery also suffer from osteoporosis [14, 15]. However, degenerative lumbar spinal stenosis combined with osteoporotic vertebral fractures involving the endplate is relatively rare in clinical practice. To date, no studies have specifically reported outcomes for this condition. For patients who fail conservative treatment, surgical intervention should be considered. The key surgical goals are adequate decompression of lumbar spinal stenosis and effective management of the osteoporotic vertebral fracture. The preferred surgical approach involves direct laminectomy decompression of the affected segment combined with vertebral augmentation of the fractured vertebra. This approach is relatively minimally invasive. Laminectomy decompression can be performed via open surgery, minimally invasive tubular techniques, or even endoscopic methods. Vertebral augmentation is a well-established and safe procedure that effectively alleviates lumbar pain. During laminectomy, preserving as much bony structure as possible is crucial to maintain segmental stability. Proper dispersion of bone cement during vertebral augmentation helps maintain vertebral height, thereby preventing symptomatic recurrence caused by postoperative vertebral height loss and subsequent spinal stenosis. For cases involving endplate fractures, this approach avoids intervertebral space manipulation, reducing the risk of fusion failure due to inadequate preparation of the fractured endplate. Nevertheless, this approach has limitations. The presence of vertebral fractures complicates preoperative assessment of segmental stability using lumbar flexion-extension radiographs. Additionally, laminectomy may further compromise stability, increasing the risk of postoperative instability, symptom recurrence, and revision surgery. Therefore, some indirect decompression methods have been explored. Chung et al. reported cases of lumbar osteoporotic vertebral fractures with radiating leg pain, treated with vertebral augmentation alone. In their patients, leg pain disappeared when lying down but worsened upon standing, despite the absence of significant spinal canal compression on imaging. They hypothesized that foraminal stenosis caused by vertebral height loss in the standing position contributed to the symptoms. Vertebral augmentation supporting vertebral height was thus proposed as an effective treatment, with favorable outcomes in a series of seven patients [4]. Miller et al. described a minimally invasive technique combining vertebral augmentation with an interspinous process spacer to simultaneously address fractures and spinal stenosis. The spacer expands the intervertebral space and spinal canal, providing indirect decompression [16]. However, in our study, all patients exhibited clear radiographic evidence of spinal stenosis, rendering these indirect decompression methods unsuitable. Among our two patients treated with decompression and kyphoplasty, satisfactory outcomes were observed at final follow-up, with no significant intervertebral height loss or instability. This may be attributed to strict patient selection, widespread cement dispersion, and minimally invasive decompression techniques.

Preoperative and intraoperative factors contributing to segmental instability are the primary surgical indications for fusion procedures [11]. The combined fusion and kyphoplasty technique has demonstrated definite therapeutic efficacy, effectively addressing neural compression, segmental instability, and vertebral fractures at the affected level. Our study further confirms excellent clinical and radiographic outcomes following this surgical approach. A major challenge in this procedure lies in the management of the intervertebral space. Fractured endplates complicate the preparation of the disc space, and residual intervertebral disc tissue and cartilaginous endplates may increase the risk of fusion failure. Possible strategies to optimize fusion outcomes include: (1) Thorough and extensive preparation of the intervertebral space by meticulous removal of the nucleus pulposus and cartilaginous endplates, with bilateral treatment if necessary; (2) Maximizing autologous bone grafting within the intervertebral space; additional posterior lateral bone grafting may be applied as needed; (3) Selection of fusion devices with appropriate height, preferentially placed on the side with relatively intact endplates; (4) Cage positioning guided by preoperative computed tomography (CT) assessment of fracture line orientation, aiming for horizontal placement along the fracture plane. Additionally, distraction and maintenance of the intervertebral space can be difficult in these patients. Therefore, thorough decompression—particularly in the foraminal region—is essential to prevent postoperative restenosis caused by inadequate distraction or implant subsidence and loosening. For the fractured vertebra, polymethylmethacrylate (PMMA) cement should be adequately diffused and supported to maintain vertebral height and reduce the risk of symptomatic recurrence related to spinal canal stenosis secondary to postoperative vertebral collapse.

The optimal fixation length remains a topic of considerable debate. Given the challenges posed by osteoporosis, vertebral fractures, difficulty in intervertebral space distraction, and fusion, extending the number of fixed segments may be necessary. However, multi-level fixation carries increased risks, including internal fixation failure, reduced spinal mobility, and greater surgical trauma, which complicate decision-making. In this study, eight out of nine cases involved L4/5 spinal stenosis combined with L5 osteoporotic fractures, while only one case involved L3/4 stenosis with an L4 fracture. The markedly higher incidence at the L4/5 segment may reflect the greater prevalence of spinal stenosis at L4/5 and osteoporotic fractures at L5. For patients with L4/5 stenosis and L5 fractures, extending fixation to include L5/S1 is often considered. However, this extension significantly increases the risks of reduced lumbar range of motion, challenges related to S1 screw fixation strength, adjacent segment degeneration, and surgical morbidity, making the decision to extend fixation less favorable [17–21]. Besides the posterior decompression and fusion techniques described in this study, anterior or combined anterior-posterior approaches may be considered. The anterior approach provides robust support and is more suitable for severe vertebral height loss or pronounced kyphosis, offering better stability, deformity correction, and fusion rates. However, it is associated with greater surgical trauma and more limited indications [22, 23]. Our team prefers posterior short-segment fixation augmented with bone cement screws, which offers the advantages of reduced surgical trauma, enhanced fixation strength, safety, and reliability.

Medical management of osteoporosis is particularly crucial in this patient population. Osteoporosis, common among older adults, accelerates spinal degeneration and poses significant challenges for spinal surgery, especially regarding internal fixation strength and fusion outcomes. Osteoporotic bone is characterized by osteopenia and inadequate mineralization, which reduce its resistance to pull-out forces. Additionally, widened pedicles and thinning of cortical bone further compromise pedicle screw fixation, leading to a higher risk of screw loosening and fixation failure [24–26]. Therefore, thorough preoperative assessment of bone quality and internal fixation strategy is essential in osteoporotic patients. Strategies may include multi-point fixation, combining multiple fixation techniques, cement-augmented pedicle screws, hydroxyapatite-coated screws, larger diameter screws, dual cortical fixation, and long-segment fixation. Intraoperatively, efforts should be made to restore appropriate sagittal balance while accepting limited correction in the coronal plane to minimize mechanical complications [26, 27]. In this study, all patients were diagnosed with osteoporotic vertebral fractures (T-score < − 2.5) and, according to the 2022 Primary Osteoporosis Diagnosis and Treatment Guidelines, were classified as very high risk for fracture. Therefore, standardized anti-osteoporotic treatment was administered perioperatively, including: (1) Zoledronic acid or denosumab as the main antiresorptive agents. For patients with adequate financial resources, a short course of teriparatide (three months) was prescribed prior to sequential treatment with zoledronic acid or denosumab; (2) Routine supplementation with vitamin D and calcium to improve baseline bone mineral density. To enhance internal fixation strength, cement augmentation was routinely employed to improve pedicle screw purchase. Furthermore, excessive intervertebral space distraction and overcorrection in sagittal and coronal planes were avoided during surgery to reduce the risk of cage subsidence and fixation failure.

All nine patients included in this study were followed for a minimum of 12 months postoperatively. Significant improvements were observed in VAS scores for both low back and leg pain, as well as in JOA scores, compared to preoperative values. These findings suggest that both decompression combined with kyphoplasty and fusion combined with kyphoplasty effectively alleviate symptoms in this patient population. However, this study has several limitations, including a small sample size and a relatively short follow-up period, which precluded comprehensive analysis of the comparative advantages, disadvantages, and long-term outcomes of different surgical techniques—such as fusion rates, adjacent segment disease, and segmental degeneration. Future studies with larger cohorts, longer follow-up durations, and randomized controlled designs are warranted to better determine the optimal surgical strategies for degenerative lumbar spinal stenosis combined with osteoporotic vertebral fractures involving the endplates.

Conclusion

Degenerative lumbar spinal stenosis combined with osteoporotic vertebral fractures involving the endplate presents considerable challenges in clinical practice. Both decompression followed by kyphoplasty and fusion combined with kyphoplasty have been demonstrated to be effective surgical options, resulting in significant clinical improvement (Table 1).

Table 1.

VAS and JOA scores before surgery, 3 months after surgery, and at the final follow-up

		Patient1	Patient2	Patient3	Patient4	Patient5	Patient6	Patient7	Patient8	Patient9
Surgical procedure		A	B	B	B	B	B	A	B	B
Follow-up(months)		37	32	30	28	23	19	18	16	13
Back pain VAS	Before surgery	3	5	5	4	4	3	4	2	5
	3 months post surgery	1	2	1	1	1	1	1	1	2
	Final follow-up	2	1	2	2	1	1	2	1	2
Leg pain VAS	Before surgery	6	5	6	7	6	6	7	7	6
	3 months post surgery	1	1	1	2	1	2	1	2	1
	Final follow-up	1	1	1	1	1	1	1	1	1
JOA	Before surgery	11	12	12	8	9	12	13	12	10
	3 months post surgery	22	24	23	21	22	21	21	22	23
	Final follow-up	19	23	24	21	22	21	21	21	24

Abbreviations

(LSS)

Lumbar spinal stenosis

(OVF)

Osteoporotic vertebral fracture

(VAS)

Visual Analog Scale

(JOA)

Japanese Orthopedic Association

(CT)

Computed tomography

(MRI)

Magnetic resonance imaging

Authors’ contributions

ZQ, WWJ, and LY contributed to the conception of the study; LY, and XLB performed the surgeries and the follow-ups; CZ, LYZ, and QJR contributed significantly to analysis and manuscript preparation; ZQ, CZ contributed significantly to the revision of the manuscript.

Funding

No funding.

Data availability

Data is available upon reasonable request, please contact author Qiang Zhang (zqywyx@163.com）.

Declarations

Ethics approval and consent to participate

The study was reviewed and approved by the ethics committee of Ruijin Hospital, Shanghai Jiaotong University School of Medicine. Informed consent was also obtained from all participants.

Consent for publication

NA.

Competing interests

The authors declare no competing interests.