A retrospective comparative study of traditional PVP and bone cement pedicle-anchored PVP techniques for stage I and II Kümmell’s disease

Abstract

Background

Kümmell’s disease (KD), characterized by delayed vertebral collapse with intravertebral vacuum cleft (IVC), remains controversial in clinical management. Traditional percutaneous vertebroplasty (PVP) may lead to cement loosening and vertebral re-collapse due to insufficient mechanical interlocking between cement and bone. This study compared the clinical efficacy of bone cement pedicle-anchored PVP (BCPA-PVP) versus conventional PVP for Stage I and II KD.

Methods

A retrospective analysis enrolled 79 patients with Stage I/II KD undergoing PVP or BCPA-PVP between March 2018 and January 2023. Patients were divided into four groups: Stage I PVP (n=18), Stage I BCPA-PVP (n=20), Stage II PVP (n=20), and Stage II BCPA-PVP (n=21). Clinical outcomes, including Visual Analog Scale (VAS) scores, Oswestry Disability Index (ODI), anterior vertebral height (AVH), Cobb angle, and complications, were evaluated preoperatively, postoperatively (day 1), and at final follow-up.

Results

For Stage I KD, no significant differences emerged between PVP and BCPA-PVP groups at final follow-up: VAS (1.06±0.66 vs. 0.90±0.64), ODI (15.33±3.24 vs. 15.60±4.76), AVH (26.94±2.29 mm vs. 27.10±2.45 mm), or Cobb angle (5.22±1.17° vs. 5.10±1.52°) (all P > 0.05). No cement loosening occurred. In Stage II KD, the PVP group showed significantly worse outcomes at final follow-up compared to BCPA-PVP: VAS (2.60±1.85 vs. 1.14±1.01, P < 0.05), ODI (30.40±12.67 vs. 19.52±9.84, P < 0.05), and AVH (20.15±2.64 mm vs. 21.86±1.72 mm, P < 0.05). Cement leakage occurred in 30.4% (24/79), with higher rates in Stage II BCPA-PVP (42.8%, 9/21). Cement loosening was observed exclusively in Stage II PVP group (25%, 5/20).

Conclusion

Conventional PVP can provide satisfactory outcomes for Stage I KD. However, BCPA-PVP is recommended for Stage II KD to reduce risks of cement loosening, vertebral re-collapse, and kyphotic progression.

Introduction

Kümmell’s disease (KD), once considered a rare spinal disorder, is characterized by delayed post-traumatic vertebral collapse with intravertebral vacuum cleft (IVC) [1–4]. First described in 1891 by German surgeon Hermann Kümmell, patients experience an asymptomatic latent period (months to years) after minor trauma, followed by progressive kyphotic deformity and neurological deficits [5–7]. With aging populations and advancements in medical imaging technologies such as CT and MRI, the detection rate of KD has significantly increased, drawing attention to its clinical management [8–10]. At present, the exact pathogenesis remains controversial, but most researchers attribute it to vertebral ischemic necrosis [6, 7, 11, 12]. This ischemic process leads to non-union of the fracture and the formation of a characteristic IVC, which is considered a pathognomonic radiographic feature of the disease [1–4]. Histologically, the IVC is lined by fibrocartilaginous tissue and surrounded by necrotic sclerotic bone, creating a mechanically unstable environment that precludes spontaneous healing [11].

Based on clinical symptoms, X-ray, and MRI findings of vertebral damage, Li et al. [13] classified KD into three stages: Stage I (vertebral height loss < 20%, no adjacent disc degeneration, minimal or no back pain), Stage II (vertebral height loss > 20%, with dynamic instability, characterized by > 3 mm of intersegmental translation or > 5°of angular change on dynamic lateral radiographs, along with adjacent disc degeneration), and Stage III (posterior cortical disruption with dynamic instability, spinal canal stenosis, and potential neurological deficits). Currently, most scholars recommend percutaneous vertebroplasty (PVP) or percutaneous kyphoplasty (PKP) for Stage I and II KD [1, 2, 14, 15], However, some scholars hold different opinions [16, 17]. They argue that due to the presence of IVC in KD patients, the distribution of bone cement within the vertebral body differs significantly from that in traditional osteoporotic vertebral compression fractures (OVCF). In KD, the bone cement is predominantly concentrated within IVC of the fractured vertebral body, forming a cement mass that fails to establish mechanical interlocking with the surrounding trabecular bone. Under such circumstances, the bone cement is highly prone to loosening and displacement at the bone-cement interface, leading to recurrence of vertebral instability. Consequently, patients may experience recurrent or exacerbated low back pain, potentially accompanied by neurological deficits [6].

To address this mechanical deficiency, some scholars have proposed the bone cement pedicle-anchored PVP (BCPA-PVP) technique [6, 18]. This modified procedure aims to create a three-dimensional stabilization construct by deliberately extending bone cement from the IVC into the bilateral pedicles. By anchoring the cement mass to the stable posterior elements, BCPA-PVP theoretically transforms a loose “cement island” into an integrated load-bearing framework, thereby enhancing resistance to shear and rotational forces and preventing loosening and displacement. Zou et al. [6] initially reported favorable short-term outcomes with this technique, but its comparative efficacy against conventional PVP, particularly when stratified by disease stage, has not been systematically evaluated.

Therefore, the purpose of this study was to conduct a retrospective comparative analysis of the clinical and radiographic outcomes of conventional PVP versus BCPA-PVP in the treatment of Stage I and II KD. we sought to determine whether BCPA-PVP offers superior long-term stability and clinical benefits, particularly for the more challenging Stage II KD. The findings of this study aim to provide evidence-based guidance for selecting the optimal minimally invasive treatment for patients with different stages of Kümmell’s disease.

Patients and methods

Written informed consent was obtained from each patient and this study was approved by Ethics Committee of Yantaishan Hospital (Yantai, China; approval no. 2025028). The study was conducted in accordance with the principles of the Declaration of Helsinki 1975.

This study enrolled patients diagnosed with Kümmell disease who underwent PVP or BCPA-PVP surgery at the Spine Surgery Center of Yantaishan Hospital from March 2018 to January 2023. The inclusion criteria for the study were as follows: (1) Diagnosis of stage I and stage II KD based on symptoms and imaging examinations; (2) Single-segment involvement; (3) Bone mineral density (BMD) T-score ≤ -2.5 SD. The exclusion criteria were: (1) Stage III KD; (2) Previous history of thoracolumbar surgery; (3) Spinal tumors or spinal infections; (4) Follow-up duration less than 12 months due to various reasons. Based on these inclusion and exclusion criteria, 79 patients were ultimately enrolled in the study. According to the different clinical stages of KD and differences in surgical approaches, the study samples were divided into four groups. Demographic and clinical data, including BMD, amount of bone cement injected, follow-up period, complications and other relevant information are presented in Table 1. BMD was measured using dual-energy X-ray absorptiometry and osteoporosis was defined by a T-score ≤-2.5 standard deviations (SD).

Table 1.

Baseline characteristics and complications across groups

Variables	StageⅠPVP Group	StageⅠ BPCA-PVP Group	StageⅡPVP Group	StageⅡ BPCA-PVP Group
Sex (M/F)	8/10 (n = 18)	10/10 (n = 20)	9/11 (n = 20)	11/10 (n = 21)
Age (y)	76.06 ± 4.12	75.79 ± 4.72	75.71 ± 3.86	75.05 ± 4.72
BMD	-3.28 ± 0.48	-3.39 ± 0.63	-3.45 ± 0.56	-3.34 ± 0.51
ICV (ml)	7.31 ± 1.02	7.90 ± 1.10	6.80 ± 0.75	6.77 ± 0.89
OT(min)	18.14 ± 1.36	27.38 ± 1.07	19.44 ± 0.92	29.76 ± 1.53
FFU(mon)	18.33 ± 1.78	17.45 ± 1.93	16.62 ± 1.80	16.35 ± 1.93
Complications
BCL	4 (22.2%)	5 (25.0%)	6 (30.0%)	9 (42.8%)
AVF	1(5.6%)	1 (5.0%)	3 (15.0%)	3 (14.3%)
BCD	0 (0%)	0 (0%)	5 (25%)	0 (0%)

M Male, F Female, y Year, BMD Bone mineral density, ICV Injected cement volume, ml Milliliter, OT Operation time, FFU Final follow-up, mon Month, BCL Bone cement leakage, AVF Adjacent vertebral fracture, BCD Bone cement displacement

Surgical procedure: All procedures were performed under local anesthesia by the same minimally invasive surgical team in the spine center. Patients were positioned prone on the Jackson table with elevated thoracic and iliac regions, allowing the abdomen to remain free to achieve hyperextension. Bilateral transpedicular approaches were performed under biplane fluoroscopic guidance for all patients.

In the PVP group, conventional surgical techniques were employed (Fig. 1A-D). For the BCPA-PVP group, distinct from traditional PVP, the puncture point was located at the superolateral quadrant of the pedicle with a needle trajectory angle of approximately 15–20° relative to the sagittal plane to minimize damage to the medial and inferior pedicle walls, ensuring safe and effective cement anchoring in the pedicle. First, under fluoroscopic guidance, the trocar and cannula system was inserted into the IVC of the vertebral body through one side pedicle. Next, the drill was advanced to create a tunnel, after which the drill was removed, and polymethylmethacrylate (PMMA, Tecres, Spa.) cement was injected into the vertebral body. The cement was injected using a standard manual injection system at a slow, controlled rate, estimated to be 0.5-1.0 mL/min. Typically, the initially injected PMMA cement resided within the IVC. Once the IVC was fully filled, the working cannula was gradually withdrawn while continuing the slow injection of PMMA cement. The puncture needle angle could be adjusted appropriately to ensure adequate filling of areas outside the IVC within the vertebral body. When the working cannula was positioned within the pedicle, the injection rate of PMMA cement must be further slowed. Concurrently, fluoroscopic monitoring was essential to observe potential cement leakage, and the patient should be assessed for any neurological symptoms. The same procedure was then repeated on the contralateral side to complete the surgical process (Fig. 1E-H).

Fig. 1 .

Imagings of Conventional PVP and BCPA-PVP for Stage I Kümmell’s Disease

Clinical and radiological assessments

Clinical and radiological assessments were performed preoperatively, on postoperative day 1, and at the final follow-up. The Visual Analog Scale (VAS) was used to assess the severity of low back pain, while the Oswestry Disability Index (ODI) was employed to evaluate the degree of functional impairment [19, 20]. With authorization, radiological data were acquired and measured through the hospital’s Picture Archiving and Communication System (PACS). Changes in anterior vertebral height (AVH) were obtained by measuring lateral radiographs or sagittal CT images. The Cobb angle was defined by drawing a line along the superior endplate of the vertebra one level above the fractured vertebra and another line along the inferior endplate of the vertebra one level below the fractured vertebra. The intersection of these two lines was determined as the Cobb angle (Fig. 2A). Additionally, the duration of final follow-up and postoperative complications were recorded and analyzed. The criteria for judging postoperative PMMA bone cement loosening were as follows: (i) Significant clinical deterioration, defined as an increase in VAS score of ≥ 2 points or an increase in ODI of ≥ 10% from the postoperative day 1 assessment. (ii) Radiographic instability, defined as a clear displacement of the cement mass of > 2 mm relative to the surrounding vertebral bone on flexion-extension lateral radiographs. (iii) Characteristic MRI findings, specifically the presence of a distinct annular zone of edematous enhancement (high signal on T2-weighted images) at the interface between the PMMA bone cement and the adjacent bone tissue. Clinical outcomes (VAS, ODI) were collected directly from patients, which eliminating inter-observer variability for these patient-reported measures. Radiological measurements (AVH, Cobb angle) were performed independently by two senior spine surgeons. All measurements were conducted using the hospital’s PACS system, which provides standardized digital measurement tools. In cases of discrepancy greater than 10%, a consensus was reached through joint re-evaluation. This consensus-based approach ensured uniform assessment across all cases.

Fig. 2.

Imagings of Conventional PVP and BCPA-PVP for Stage II Kümmell’s Disease

Treatment of osteoporosis

Treatment of osteoporosis

The patients were advised to undergo regular anti-osteoporosis therapy throughout the perioperative and follow-up periods. It was recommended that patients take daily calcium and vitamin D supplements. In accordance with current clinical guidelines and individual patient profiles, additional pharmacological interventions were prescribed. For patients with normal renal function, oral bisphosphonates were commonly used as first-line therapy. For patients with renal insufficiency or those intolerant to bisphosphonates, denosumab was administered as the preferred alternative. For patients with severe osteoporosis (T-score ≤ -3.0 SD) and without contraindications, teriparatide was suggested as a first-line anabolic option when economically feasible, given its superior efficacy in increasing bone mineral density and reducing fracture risk. The choice of anti-osteoporotic agent was made on an individual basis, considering renal function, cost, patient preference, and potential side effects.

Statistical analysis

All statistical analyses were performed using SPSS 22.0 software (IBM Corp., Armonk, NY, USA ). Each variable was expressed as mean ± standard deviation (SD). For comparisons of continuous variables between two independent groups at a single time point, the independent samples t-test was used for normally distributed data, and the Mann-Whitney U test was applied for non-normally distributed data. Normality was assessed using the Shapiro-Wilk test. The Bonferroni correction was applied to control the family-wise error rate, with a significance level set at P < 0.0125. For all other analyses, a P-value < 0.05 was considered statistically significant. Categorical variables, such as sex and complication rates, were compared between groups. The chi-square test was used when all expected cell frequencies were ≥ 5. When more than 20% of cells had expected frequencies < 5, Fisher’s exact test was employed instead.

Results

According to the stages of KD and different surgical approaches, the 79 patients included in the study were divided into four groups: Stage Ⅰ PVP Group (18 cases), Stage Ⅰ BCPA-PVP Group (20 cases), Stage Ⅱ PVP Group (20 cases), and Stage Ⅱ BCPA-PVP Group (21 cases). Overall analysis showed that the average age was 75.65 ± 4.36 years ( range 65–84 years), the mean preoperative BMD T-score was − 3.37 ± 0.55 SD ( range − 2.6 to -4.8 SD ), the average intraoperative bone cement volume injected was 6.98 ± 0.96 ml ( range 5.1–9.3 ml ), the average operation time was 24.12 ± 4.93 min (range 18.1–31.3 min), and the mean follow-up duration was 17.19 ± 1.91 months ( range 13–22 months ). Detailed variations of these parameters across groups are presented in Table 1. No statistically significant differences were observed in intergroup comparisons of these indicators (P > 0.05 ).

For Stage I KD, both the PVP and BCPA-PVP groups achieved significant and sustained improvements in all clinical and radiological outcomes. At final follow-up, no significant intergroup differences were observed in VAS score (1.06 ± 0.66 vs. 0.90 ± 0.64, P = 0.433), ODI (15.33 ± 3.24% vs. 15.60 ± 4.76%, P = 0.841), AVH (26.94 ± 2.29 mm vs. 27.10 ± 2.45 mm, P = 0.832), or Cobb angle (5.22 ± 1.17° vs. 5.10 ± 1.52°, P = 0.780). No instances of bone cement loosening were observed in either Stage I group (Table 2).

Table 2.

Comparative analysis of variables at different clinical stages and time points

Variables	Time point	Stage ⅠPVP Group (Mean ± SD)	StageⅠ BCPA-PVP Group (Mean ± SD)	p-value	Stage ⅡPVP Group (Mean ± SD)	StageⅡ BCPA-PVP Group (Mean ± SD)	p-value
VAS	Pre	5.94 ± 0.90	6.05 ± 0.89	0.701	6.30 ± 0.92	6.19 ± 0.81	0.682
	Post	1.17 ± 0.38	1.10 ± 0.45	0.593	0.95 ± 0.39	1.00 ± 0.45	0.715
	FFU	1.06 ± 0.66	0.90 ± 0.64	0.433	2.60 ± 1.85	1.14 ± 1.01	0.002
ODI (%)	Pre	66.33 ± 9.12	66.70 ± 9.45	0.901	65.20 ± 9.84	66.57 ± 8.92	0.632
	Post	22.00 ± 3.74	20.10 ± 4.12	0.143	18.70 ± 3.45	18.86 ± 3.12	0.871
	FFU	15. 33 ± 3.24	15.60 ± 4.76	0.841	30.40 ± 12.67	19.52 ± 9.84	0.003
AVH (mm)	Pre	26.28 ± 2.38	26.25 ± 2.52	0.972	20.25 ± 2.31	20.62 ± 2.18	0.602
	Post	27.89 ± 2.34	28.05 ± 2.41	0.840	22.85 ± 1.97	23.10 ± 1.89	0.681
	FFU	26.94 ± 2.29	27.10 ± 2.45	0.832	20.15 ± 2.64	21.86 ± 1.72	0.017
Cobb Angle (°)	Pre	6.06 ± 1.16	5.95 ± 1.457	0.798	16.05 ± 4.72	15.71 ± 3.81	0.791
	Post	5.06 ± 1.16	4.90 ± 1.41	0.697	13.55 ± 4.03	13.48 ± 3.12	0.949
	FFU	5.22 ± 1.17	5.11 ± 1.52	0.780	17.20 ± 5.12*	15.57 ± 3.37*	0.214

VAS Visual Analogue Scale, ODI Oswestry Disability Index, AVH Anterior vertebral height, BCPA Bone bement pedicle-anchored, PVP Percutaneous vertebroplasty

In contrast, for Stage II KD, significant differences between the two treatment groups emerged at the final follow-up. While both the PVP and BCPA-PVP groups demonstrated comparable and effective immediate postoperative improvements (postoperative day 1) in all parameters (P > 0.05), the PVP group showed significant deterioration by the final follow-up. Specifically, at final follow-up, the Stage II PVP group had significantly worse VAS scores (2.60 ± 1.85 vs. 1.14 ± 1.01, corrected P = 0.008) and ODI scores (30.40 ± 12.67% vs. 19.52 ± 9.84%, corrected P = 0.012) compared to the Stage II BCPA-PVP group. Radiographically, the PVP group exhibited greater loss of anterior vertebral height correction (AVH: 20.15 ± 2.64 mm vs. 21.86 ± 1.72 mm, P = 0.017), although this difference did not remain statistically significant after Bonferroni correction (corrected P = 0.068). Furthermore, the PVP group demonstrated significant progressive kyphosis, with the Cobb angle worsening from 13.55 ± 4.03° postoperatively to 17.20 ± 5.12° at final follow-up (P < 0.05), whereas the BCPA-PVP group maintained its postoperative correction (13.48 ± 3.12° to 15.57 ± 3.37°, P > 0.05 for within-group change). However, the intergroup difference in Cobb angle at final follow-up did not reach statistical significance (P = 0.214)(Fig. 3).

Fig. 3.

Clinical Outcome Trends (VAS, ODI, AVH) and Postoperative Complication Rates Across Four Study Groups of Stage I/II Kümmell’s Disease

Cement leakage remains the most common complication. In this study, a total of 24 patients experienced cement leakage, representing a leakage rate of 30.4%. Notably, 9 cases in the Stage II BCPA-PVP Group exhibited leakage, with a significantly higher leakage rate of 42.8%, which may be related to the increased leakage probability during the process of cement anchoring in the pedicle(Fig. 2H). Additionally, 8 patients developed adjacent vertebral fractures (AVF), corresponding to an incidence rate of 10.1%. Postoperative bone cement loosening occurred in 5 patients, all of whom were in the Stage II PVP Group, potentially serving as an important factor contributing to poor long-term prognosis. The specific variations of these parameters among different groups are detailed in Table 1.

Discussion

Currently, the exact pathogenesis of KD remains unclear, but the widely accepted view is that it represents a delayed ischemic osteonecrosis of the vertebral body following trauma [6, 11, 12, 21]. Its clinical features include an asymptomatic period after minor vertebral trauma, followed by intractable low back pain and progressive kyphotic deformity developing over months or years [6]. The intravertebral vacuum cleft (IVC) observed on X-ray and CT imaging is considered a characteristic radiographic feature of vertebral osteonecrosis [1–4, 22]. MRI demonstrates high sensitivity and specificity for diagnosing KD. On MRI images, the intravertebral vacuum cleft (IVC) can be observed to be filled with gas, fluid, or a gas-fluid mixed signal intensity. The dynamic changes of gas and fluid within the IVC primarily occur due to variations in the patient’s position and the duration of recumbency [23, 24]. On T2-weighted MRI sequences, a “double-line sign” can be observed: the IVC is surrounded by a hyperintense inner zone bordered externally by hypointense sclerotic bone. Hasegawa et al. [25] conducted histological examinations of IVC tissue in 5 patients and found that the hyperintense zone corresponds to fibrocartilaginous tissue, while the peripheral hypointense area represents necrotic sclerotic bone. These pathological characteristics indicate that traditional conservative treatments such as bracing, bed rest, and analgesics are unsuitable for KD and may lead to disease progression, vertebral collapse, and even neurological deficits [26, 27].

For patients with stage III Kümmell disease, who often present with kyphotic deformity due to incomplete posterior vertebral cortex and may exhibit neurological deficits, the preferred surgical treatment is posterior pedicle screw fixation, supplemented with spinal canal decompression or osteotomy correction if necessary [5, 8]. For stage I and II Kümmell disease, most scholars advocate minimally invasive surgical approaches such as PVP or PKP [1, 2, 14, 15]. A prospective cohort study by Chang et al. [1] demonstrated that both PVP and PKP achieve favorable clinical outcomes in treating KD, with no significant differences in long-term follow-up between the two techniques. However, some studies have reported bone cement loosening during long-term follow-up, attributed to the concentration of cement within the IVC, which creates a distinct boundary with surrounding vertebral bone and lacks sufficient mechanical interlock [6, 16, 17]. Heo et al. [16] documented vertebral re-collapse in 6 out of 21 patients (28.57%) who underwent PVP for KD during follow-up. Zou et al. [6] proposed a bilateral BCPA-PVP technique to establish a three-dimensional stabilization structure by connecting IVC cement with bilateral pedicles, effectively preventing cement loosening.

Our study provides compelling evidence that the choice between conventional PVP and BCPA-PVP should be guided by a stage-specific strategy. The key determinant lies in the distinct pathological biomechanics of each stage. In Stage I KD, characterized by minimal vertebral height loss and the absence of dynamic instability, the IVC is typically small and located anterosuperiorly. The primary goal of surgery is to obliterate this cleft and provide moderate support. In this context, conventional PVP is sufficient. After filling the IVC, the cement can interdigitate with the surrounding trabecular bone or form additional supportive foci elsewhere in the vertebral body. This creates a stable composite structure that effectively resists compressive forces, explaining the satisfactory and sustained outcomes we observed in our Stage I PVP patients, with no instances of cement loosening.

The clinical scenario and mechanical demands are fundamentally different in Stage II KD. Here, the greater vertebral height loss and the presence of dynamic instability indicate a more extensive collapse of the trabecular architecture and a larger IVC. The bone cement injected during PVP tends to be largely confined within this capacious cleft, forming a large, isolated “cement island” that lacks robust integration with the surrounding sclerotic bone walls. This configuration is mechanically precarious. Under repetitive spinal loads, micromotion occurs at the bone-cement interface, leading to progressive loosening, loss of support, and eventual re-collapse. This pathomechanism is directly corroborated by our findings: cement loosening was exclusively observed in the Stage II PVP group (25%), which subsequently manifested as significant deterioration in VAS, ODI, and AVH at final follow-up (Fig. 2B-D).

The BCPA-PVP technique is specifically designed to address this mechanical deficiency in Stage II KD. Its core innovation is the creation of a three-dimensional “cement-bridge” construct. By deliberately anchoring cement within the bilateral pedicles and ensuring its continuity with the cement mass in the IVC, the technique effectively bridges the unstable anterior vertebral body to the stable posterior elements. This construct transforms a loose cement island into an integrated load-bearing framework. The pedicle anchors act as robust pillars, distributing stresses away from the fragile bone-cement interface within the vertebral body and significantly enhancing resistance to shear and rotational forces. This biomechanical superiority translates directly into the superior clinical and radiological outcomes we documented in the Stage II BCPA-PVP group, including maintained vertebral height, sustained pain relief, and a complete absence of cement loosening (Fig. 2E-H).

Is BCPA-PVP surgery recommended for all patients with stage I and stage II KD? In our study, for stage I KD, there were no statistically significant differences in postoperative and final follow-up VAS scores, ODI scores, AVH, and Cobb angles between the PVP group and the BCPA-PVP group. No bone cement loosening was observed during follow-up. This may be related to the following reasons. First, patients with stage I KD have minimal vertebral height loss, typically with small IVC located in the anterosuperior portion of the vertebral body and no dynamic instability. Second, during surgery, after filling the IVC with PMMA cement, the puncture angle can be adjusted to fill other spaces within the vertebral body. Even if the cement cannot connect with the IVC as a single unit due to sclerotic bone barriers, it still provides sufficient support to the vertebral body. The cement within the IVC lacks space for loosening or displacement.

For stage II KD, there were no statistically significant differences in VAS scores, ODI scores, AVH, or Cobb angles between the PVP and BCPA-PVP groups on postoperative day 1. However, significant differences in VAS scores, ODI scores, and AVH emerged at the final follow-up. Although the Cobb angle showed no intergroup differences, significant intra-group differences were observed between postoperative and final follow-up measurements, indicating progressive kyphotic angulation during follow-up. The primary reason lies in the larger IVC size in the PVP group, where PMMA cement was confined to the IVC, resulting in greater vertebral height loss and dynamic instability. In such cases, the advantages of BCPA-PVP become evident.

Regarding the learning curve of the BCPA-PVP technique, this modified procedure is based on the conventional PVP, with no additional complex surgical instruments required, and thus has a moderate and manageable learning curve for spine surgeons with basic experience in percutaneous vertebroplasty. The core technical difference from conventional PVP lies in the precise control of the puncture trajectory and the slow, staged injection of bone cement during pedicle anchoring—two key steps that determine the success of cement fixation and the reduction of leakage risk.

Similar to previous literature reports [1, 27], Cement leakage remained the most common complication in this study, occurring in 34% of cases. Notably, the incidence of cement leakage was higher in BCPA-PVP group compared to conventional PVP group. This is primarily due to the increased risk of leakage during the process of cement anchoring in the pedicle, which poses significant dangers. During surgery, close monitoring of patient responses and increased fluoroscopic frequency are essential to mitigate risks. Some scholars have attempted to use bridging screws to connect the IVC as an alternative to cement anchoring in the pedicle, thereby reducing the risk of cement leakage, offering new insights and options [28–30]. The incidence of adjacent vertebral fracture showed no significant difference from previous literature reports [6, 15]. Cement loosening predominantly occurred in the stage II PVP group, with a 25% incidence rate, aligning closely with the 28.57% reported by Heo et al. [16].

This study has certain limitations. The research was designed as a retrospective, single-center investigation with a limited sample size, which may have affected the reliability of the findings. Future research should involve prospective, large-scale randomized controlled studies to further validate the conclusions’ reliability. It should be noted that the use of teriparatide may be limited by cost and availability in some regions, which could affect the generalizability of our anti-osteoporosis regimen. Furthermore, the sample size, while sufficient to demonstrate the primary outcome differences between groups, precluded robust subgroup analyses (e.g., based on specific vertebral levels or detailed BMD stratification) to identify potential modifiers of the treatment effect. Future research should involve prospective, large-scale randomized controlled studies with larger cohorts to validate our conclusions and enable meaningful subgroup analyses. Fourth, as a retrospective study, certain technical parameters such as precise real-time cement injection pressure were not routinely recorded, which may limit the granularity of technical reproduction. Furthermore, the consensus-based approach for radiographic measurements, while ensuring clinical consistency, precludes the calculation of formal inter-rater reliability statistics. Future prospective studies would benefit from the prospective collection of such data. The follow-up duration (mean 17.19 months, range 13–22 months) is shorter than the more than 2 years often recommended for assessing long-term stability in Kümmell’s disease (KD). As KD is characterized by delayed vertebral collapse, the current follow-up period may not capture late-onset complications such as cement loosening or vertebral re-collapse in a small subset of patients. We will extend the follow-up period to 3 years in future work to verify the long-term durability of BCPA-PVP.

Conclusion

In summary, this study demonstrates that for Stage I KD, percutaneous vertebroplasty (PVP) alone can achieve satisfactory clinical outcomes. For Stage II KD, the BCPA-PVP technique is recommended to prevent complications such as bone cement loosening, vertebral re-collapse, and progression of kyphotic deformity.

Abbreviations

KD

Kümmell’s disease

BCPA

Bone cement pedicle-anchored

PVP

Percutaneous vertebroplasty

PKP

Percutaneous kyphoplasty

IVC

Intravertebral vaccum cleft

OVCF

Osteoporotic vertebral compression fracture

CT

Computed tomography

MRI

Magnetic resonance imaging

PMMA

Polymethylmethacrylate

VAS

Visual analogue scale

ODI

Oswestry disability index

AVH

Anterior vertebral height

BMD

Bone mineral density

DXA

Dual energy X-ray absorptiometry

Authors’ contributions

Jianmin Wang designed the research plan and wrote the manuscript. Human wang performed the statistical analysis of the research data and assisted Jianmin Wang in the writing of the manuscript. Wei Du, Yuchi Zhao and Junjie Jiang were responsible for data collection, Image preparation, Software processing. Dexin Zou was responsible for supervision, funding acquisition, and final manuscript approval. All authors read and approved the final version of the manuscript.

Funding

No funding was received for this study.

Data availability

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.

Declarations

Ethics approval and consent to participate

The study was approved by Ethics Committee of Yantaishan Hospital. Consent to publication was obtained from each patient.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.