Percutaneous kyphoplasty in the treatment of Kümmell disease in lumbar scoliosis: A case report.

BACKGROUND: Due to mechanical imbalance in the spine, elderly scoliosis patients tend to develop vertebral fracture nonunion, i.e., Kümmell disease, when osteoporotic vertebral compression fractures occur. However, accompanying vertebral rotational deformities make surgical procedures challenging risky. Such patients are usually compelled to undergo conservative treatment and there are very few reports on minimally invasive surgeries for them. We first-time report a patient with Kümmell disease and lumbar scoliosis treated with percutaneous kyphoplasty (PKP) under O-arm guidance. CASE SUMMARY: An 89-year-old female was admitted to the hospital due to delayed low back pain after a fall. She was diagnosed with Kümmell disease based on physical and radiologic examinations. The patient experienced severe scoliosis and subsequently underwent O-arm-guided kyphoplasty, resulting in a significant alleviation of low back pain. CONCLUSION: PKP has good efficacy in treating Kümmell disease. However, surgical risks are elevated in scoliosis patients with Kümmell disease due to the abnormal anatomical structure of the spine. O-arm assisted operations play a crucial role in decreasing surgical risks.

Efficacy and Safety of High-Viscosity Bone Cement in Percutaneous Vertebroplasty for Kummell's Disease.

Background: To analyze and evaluate the clinical outcomes of using high-viscosity bone cement compared to low-viscosity bone cement in percutaneous vertebroplasty (PVP) for treatment of Kummell's disease. Methods: From July 2017 to July 2019, 68 Kummell's disease patients who underwent PVP were chosen and separated into 2 groups: H group (n = 34), were treated with high-viscosity bone cement and L group (n = 34), treated with low-viscosity bone cement during treatment. The operation time, number of fluoroscopy tests done, and amount of bone cement perfusion were recorded for both groups. Clinical outcomes were compared, by measuring their Visual Analog Scale (VAS), Oswestry Disability Index (ODI), Kyphosis Cobb's angle, vertebral height compression rate, and other complications. Results: High-viscosity group showed less operation time and reduced number of fluoroscopy tests than the low-viscosity group (P < 0.05). When compared to preoperative period, both groups' VAS and ODI scores were significantly reduced at 1 day and 1 year postoperatively (P < 0.05). The vertebral height compression rate and Cobb's angle were significantly lower (P < 0.05) in both groups after surgery compared with those before surgery (P < 0.05). The cement leakage rate in group H was 26.5%, which was significantly lower than that in group L, which was 61.8% (P < 0.05). Conclusions: High-viscosity and low-viscosity bone cement in PVP have similar clinical efficacy in reducing pain in patients during the treatment, but in contrast, high-viscosity bone cement shortens the operative time, reduces number of fluoroscopy views and vertebral cement leakage and improves surgical safety.

A Comparative Study of 2 Techniques to Avoid Bone Cement Loosening and Displacement After Percutaneous Vertebroplasty Treating Unstable Kummell Disease.

OBJECTIVE: Percutaneous vertebroplasty (PVP) is currently the most common surgical procedure for unstable Kummell disease (KD), but cement loosening or displacement often occurs after PVP. We had been using percutaneous pediculoplasty (PPP) or a self-developed bone cement bridging screw system to avoid this severe complication. This study intends to compare these novel surgical procedures through a 2-year follow-up evaluation. METHODS: From May 2017 to May 2021, 77 patients with single-level unstable KD were included in the PPP group, and 42 patients received the PVP-bone cement bridging screw system were included in the screw group. The changes in the vertebral body index (VBI), bisegmental Cobb angle, visual analogue scale (VAS) and Oswestry Disability Index (ODI) and the cement loosening rate and displacement rate at different follow-up time points were used to evaluate the clinical efficacy. RESULTS: There was no significant difference in VBI or bisegmental Cobb angle between the 2 groups (p > 0.05) before operation, immediately after operation and at 6-month followup, while at 1-year and 2-year postoperative evaluations, the screw group had higher VBI and bisegmental Cobb angle than the PPP group (p < 0.05). Before operation, immediately after operation, at 6-month and 1-year follow-up, there was no significant difference in VAS or ODI score between the 2 groups (p > 0.05), while at 2-year follow-up, the screw group still had higher VAS and ODI scores than the PPP group (p < 0.05). No bone cement displacement occurred in both groups, but the rate of bone cement loosening was 14.29% in group PPP, and 0 in screw group (p < 0.05). CONCLUSION: This 2-year follow-up study shows that the PVP-bone cement bridging screw system combined therapy had better midterm treatment efficacy than the PVP-PPP combined therapy in patients with unstable KD, and the bone cement bridging screw system is a preferred therapy with better anti cement loosening ability.

[Percutaneous pedicle screw anchored vertebral augmentation for the treatment of Kümmell disease without neurological symptoms].

OBJECTIVE: To explore the clinical effect of percutaneous pedicle screw anchored vertebral augmentation(PPSAVA) in the treatment of asymptomatic Kümmell disease without neurological symptoms. METHODS: The clinical data of 20 patients with Kümmell disease without neurological symptoms treated with PPSAVA in our hospital from January 2019 to December 2021 were analyzed retrospectively, including 5 males and 15 females, aged 56 to 88 (74.95±9.93) years old. and the course of disease was 7 to 60 days with an average of (21.35±14.46) days. All patients were treated with PPSAVA. The time of operation, the amount of bone cement injected and the leakage of bone cement were recorded. The visual analogue scale(VAS), Oswestry disability index(ODI), vertebral body angle(VBA), anterior edge height and midline height of vertebral body were compared among the before operation, 3 days after operation and during the final follow-up. The loosening and displacement of bone cement were observed during the final follow-up. RESULTS: All the 20 patients completed the operation successfully. The operation time was 30 to 56 min with an average of (41.15±7.65) min, and the amount of bone cement injection was 6.0 to 12.0 ml with an average of (9.30±1.49) ml. Bone cement leakage occurred in 6 cases and there were no obvious clinical symptoms. The follow-up time was 6 to 12 months with an average of (8.43±2.82) months. The VBA, anterior edge height and midline height of of injured vertebral body were significantly improved 3 days after operation and the final follow-up(P<0.05), and the VBA, anterior edge height and midline height of of injured vertebral body were lost in different degrees at the final follow-up (P<0.05). The VAS and ODI at 3 days after operation and at the final follow-up were significantly lower than those at preoperatively(P<0.05), but the VAS score and ODI at the final follow-up were not significantly different from those at 3 d after operation(P>0.05). At the last follow-up, no patients showed loosening or displacement of bone cement. CONCLUSION: PPSAVA is highly effective in treating Kümmell disease without neurological symptoms, improving patients' pain and functional impairment, and reducing the risk of cement loosening and displacement postoperatively.

Percutaneous cement-augmented short-segment pedicle screw fixation plus percutaneous vertebroplasty for stage III Kummell's disease without neurological symptoms: A case report.

INTRODUCTION: The incidence of stage III Kummell's disease without neurological symptoms is increasing in elderly patients with osteoporotic thoracolumbar fractures. However, the surgical method is still controversial in this condition. This report presented a case of Kummell's disease in which percutaneous bone cement-augmented short-segment pedicle screw fixation combined with percutaneous vertebroplasty was performed, providing a reference for the surgical approach. CASE PRESENTATION: The patient was a 72-year-old female who presented unexplained lower back pain accompanied with limited mobility for the past three months. Based on her medical history, physical examinations, and imaging studies, it was confirmed that she had Kummell's disease in stage III without neurological symptoms. We treated her with percutaneous bone cement-augmented short-segment pedicle screw fixation combined with percutaneous vertebroplasty on the symptomatic vertebrae. CLINICAL DISCUSSION: The majority of patients with stage III Kummell's disease have severe osteoporosis, which result in failure of the internal fixation and a series of other complications. Maintaining the stability of the internal fixation system is crucial, especially after screwing and subsequent locking. When augmented with bone cement, the grip and pull-out resistance of the percutaneous pedicle screws enhance greatly. Simultaneously, percutaneous vertebroplasty on the symptomatic vertebrae can immediately support the spine unit's stability mechanically and maintain the shape of the vertebrae after reduction. CONCLUSIONS: The percutaneous bone cement-augmented short-segment pedicle screw fixation combined with percutaneous vertebroplasty on the symptomatic vertebrae is an effective treatment for stage III Kummell's disease without neurological symptoms. It can effectively restore the vertebral height, correct the kyphotic deformities, improve spinal canal stenosis, and achieve satisfactory short-term clinical outcomes.

The Use of Spiral Cement Injector for Percutaneous Vertebroplasty to Treat Kümmell Disease: A Retrospective Study.

BACKGROUND: Percutaneous vertebroplasty (PVP) is a common method used to treat Kümmell disease. In patients without neurologic symptoms, we sought to evaluate whether using the new spiral injectors instead of the traditional push-rod injectors in PVP can result in improved clinical efficacy for the treatment of Kümmell disease. METHODS: A clinical retrospective study was conducted between August 2018 and December 2020. The study included patients diagnosed with single-level thoracolumbar Kümmell disease who underwent PVP surgery. The patients were divided into 2 groups: an observation group consisting of 53 patients treated with spiral injectors and a control group consisting of 68 patients treated with push-rod injectors. RESULTS: A 2-year follow-up period was adopted. The bone cement injection volume and occurrence of bone cement leakage were significantly greater in the observation group compared with the control group (P < 0.05). The observation group had significantly shorter operation time and intraoperative fluoroscopy times compared with the control group (P < 0.05). The scores for the visual analog scale and Oswestry Disability Index in both groups were significantly lower at 3 days or 3 months and 2 years after surgery compared with before surgery, with the scores at 2 years after surgery being significantly lower than those at 3 days or 3 months for both groups (P < 0.05). The relative anterior ledge height and Cobb angle showed significant improvement at 3 days and 2 years after surgery compared with before surgery in both groups (P < 0.05), but patients in the observation group experienced substantial improvement at 3 days and 2 years after surgery compared with those in the control group (P < 0.05). In both groups, the relative anterior ledge height was noticeably lower 2 years after surgery compared with 3 days after surgery (P < 0.05). Concurrently, there was a significant increase in the local Cobb angle over time in both groups (P < 0.05). CONCLUSIONS: The implementation of both spiral injectors and traditional push-rod injectors in PVP surgery yields effective pain relief, improved function, partially restored vertebral height, and corrected kyphosis in treating Kümmell disease. Compared with the push-rod injector, the spiral injector is highly efficient in restoring vertebral height, correcting kyphosis, and minimizing fluoroscopy use and operation time, but it carries a greater risk of bone cement leakage.

Comparison of the Clinical Efficacy and Bone Cement Distribution Difference Between Kummell's Disease and Osteoporotic Vertebral Compression Fracture After Percutaneous Kyphoplasty.

BACKGROUND: Kummell's disease (KD) and osteoporotic vertebral compression fracture (OVCF) are commonly found in patients with osteoporosis. Several studies have been conducted on bone cement distribution in OVCF or KD; a comparison between the 2 diseases is rarely reported. OBJECTIVES: To compare the clinical efficacy and bone cement distribution difference between KD and OVCFs after percutaneous kyphoplasty (PKP). STUDY DESIGN: This was a retrospective, nonrandomized controlled study. SETTING: Department of Orthopedics from an affiliated hospital. METHODS: From January 2018 to December 2020, 61 patients who underwent PKP surgery for single KD or OVCF and met the inclusion criteria were retrospectively reviewed. All patients were assigned to 2 groups: the KD group and the OVCF group. Clinical and radiologic characteristics, including the bone cement volume, leakage, bone cement dispersion scale, anterior vertebral height (AVH), median vertebral height (MVH), posterior vertebral height (PVH), Cobb angle and Visual Analog Scale (VAS) were analyzed and compared using Mimics three-dimensional (3D) reconstruction images and 3D reconstruction computed tomography, preoperatively, postoperatively, and 2 years after the operation, respectively. The correlations between the bone cement dispersion scale and the VH improvement rate (VHIR), VH change rate (VHCR), VAS improvement rate (VASIR), and follow-up VAS improvement rate (f-VASIR) were also evaluated. RESULTS: The mean follow-up time was 24.0 months. Postoperative VH, Cobb angle, vertebra volume, and VAS score were significantly improved in the 2 groups (P < 0.05). There was no statistical difference in postoperative parameters between the 2 groups. While a strong positive correlation between VHIR and bone cement dispersion scale was observed in the OVCF group (P < 0.01), no significant correlation between VHIR and bone cement dispersion scale was found in the KD group. There was no correlation between VASIR and bone cement dispersion scale in both groups. Compared with postoperation, VH was lower in both groups in later follow-up, and the difference between the 2 groups was statistically significant (P < 0.05). VH, VAS, f-VASIR, and VHCR had a worse manifestation in the KD group than in the OVCF group. However, no significant correlation was found between VHCR, f-VASIR, and bone cement dispersion scale in the 2 groups. LIMITATIONS: This study was limited by the non-randomized design, small sample size, and lack of a comprehensive follow-up period. CONCLUSIONS: Although there was no significant difference in the bone cement distribution and early clinical efficacy between KD and OVCF patients under the same surgical plan and surgeon, OVCF patients exhibited better long-term radiologic and clinical outcomes.

[Effect of Kümmell's disease with kyphosis on spinal-pelvic sagittal parameters].

OBJECTIVE: To explore the effect of Kümmell's disease with kyphosis on the sagittal morphology of the spine-pelvis. METHODS: A retrospective analysis of 34 patients of Kümmell's disease with kyphosis （Kümmell group） admitted from August 2015 to September 2022, including 10 males and 24 females with an average age of （71.1±8.5） years old. A control group of 37 asymptomatic population aged （69.3±6.7） years old was matched. Spinal-pelvic sagittal parameters were measured on the anterior-posterior and lateral X-rays of the whole spine in the standing position, including segmental kyphosis（SK） or thoracolumbar kyphosis（TLK）, thoracic kyphosis（TK）, lumbar lordosis（LL）, pelvic incidence（PI）, pelvic tilt（PT）, sacral slope（SS）, sagittal vertical axis（SVA）, T1 pelvic angle（TPA） and PI-LL. Vertebral wedge angle（WA） in Kümmell was measured and differences in parameters among groups were analyzed and the relationship between spino-pelvic parameters and WA, SK were also investigated. RESULTS: TK, SK, PT, SVA, TPA and PI-LL in Kümmell group were significantly larger than those in control group （P<0.05）, LL and SS in Kümmell group were significantly decreased than those in control group （P<0.05）, and there was no significant difference in PI between two groups （P>0.05）. In Kümmell group, WA（30.8±5.9）° showed a positive correlation with SK and TK（r=0.366, 0.597, P<0.05）, and SK was significantly correlated with LL and SS（r=0.539, -0.591, P<0.05）. Strong positive correlation between LL and PI, SS, SVA, TPA, PI-LL were also confirmed in patients with Kümmell with kyphosis（r=0.559, 0.741, -0.273, -0.356, -0.882, P<0.05）. CONCLUSION: Patients with Kümmell with kyphosis not only have segmental kyphosis, but also changes the overall spinal-pelvic sagittal parameters, including loss of lumbar lordosis, pelvic retrorotation, trunk forward tilt. The surgical treatment of Kümmell disease should not only pay attention to the recovery of the height of the collapsed vertebra, but also focus on the overall balance of the spine-pelvic sagittal plane for patients with kyphosis.

Comparison of the Clinical Outcomes of Vesselplasty vs. Percutaneous Vertebroplasty for the Treatment of Neurologically Intact Osteoporotic Kümmell's Disease: A Retrospective Study.

Kummell's disease (KD) is a rare clinical complication of osteoporotic vertebral compression fractures (OVCFs). Minimally invasive surgery is an important way to treat KD. In this paper, we used Percutaneous Vertebroplasty (PVP) and Vesselplasty (VP) to treat KD. 125 patients with KD were admitted to our hospital. Among them, 89 patients received PVP and 36 received VP. All patients underwent operations successfully. VAS scores and ODI of both groups at each postoperative time point were lower than preoperatively. Postoperative Cobb angle of both groups postoperatively was lower than preoperatively (p < 0.05). The anterior height and ratio of vertebra compression of both groups postoperatively was lower than preoperatively (p < 0.05). Cement leakage occurred in 16 vertebrae (16/89) in PVP group and one (1/36) in VP group. Two patients suffered from transient paraplegia in PVP group immediately after operation. Adjacent vertebral fractures occurred in one patient in PVP group and one in VP group. Re-fracture of affected vertebra occurred in one patient in PVP group. Besides, four patients suffered from bone cement loosening in PVP group while one in VP group. Both PVP and VP play an important effect in pain relief and functional recovery for the treatment of KD. And VP is more effective than PVP in preventing cement leakage.

Minimally Invasive Surgery Transpedicular Intrabody Cage Technique for the Management of Kummell Disease.

BACKGROUND: The treatment of Kummell disease remains controversial, with a wide variety of options proposed in the literature. This study aims to introduce a unique and minimally invasive approach for the treatment of Kummell disease and present the clinical results of this technique. METHODS: Twenty patients underwent surgery using the minimally invasive surgery transpedicular intrabody cage (MISTIC) technique from 2014 to 2016. Postoperatively, patients were seen at 3, 6, and 12 months after surgery. Visual analog scale and Oswestry Disability Index scores were collected, and patient outcomes were graded according to the modified MacNab's criteria. Radiological outcomes were assessed through measurements of the anterior vertebral height (AH), mean vertebral body height (BH), and segmental angle (SA) on standing lateral radiographs pre- and postoperatively. RESULTS: There was significant improvement in the SA, AH, and BH postoperatively. The SA improved from 15.2 ± 8.7° of kyphosis to 1.2 ± 5.2° (P < 0.01) in the immediate postoperative period. The AH increased from 13.3 ± 14.6 to 22.6 ± 12.2 mm (P < 0.01), and at the final follow-up, it was 21.9 ± 12.6 mm (P < 0.01). Similarly, the BH increased from 18.5 ± 6.8 to 25.6 ± 7.6 mm (P < 0.01) postsurgery, and at the final follow-up, it was 23.6 ± 4.4 mm (P < 0.01). CONCLUSIONS: The MISTIC technique offers significant correction of kyphosis and restoration of the vertebral anatomy following surgery. These results were maintained at 12 months postoperation, with a 100% union rate of the fractures. Additionally, patients experienced significant pain relief and improvement in their ODI scores that were maintained at 12 months.

Transpedicular Intravertebral Cage Augmentation Using Expandable Cage in Kummell Disease: Technical Note and Case Series.

OBJECTIVE: To demonstrate the surgical techniques for transpedicular intravertebral cage augmentation (TPICA) using an expandable cage for Kummell disease, which requires posterior surgical stabilization, and provide the preliminary surgical outcomes. METHODS: Six consecutive patients undergoing TPICA surgery using an expandable cage with a minimum 6-month follow-up were evaluated. Radiographic analysis to evaluate the local kyphosis angle, restoration ratio of anterior vertebral height of the index vertebra, and clinical outcomes including the Oswestry Disability Index, EuroQol 5-dimension instrument, and visual analog scale for back and leg pain, were compared between the preoperative and final follow-ups. RESULTS: All patients showed improvements in all clinical outcomes and were able to walk independently without support at the last follow-up. In radiographic evaluation, the mean preoperative restoration ratio of anterior vertebral height was 41.2 ± 15.6%, which increased postoperatively to 70.3 ± 20.5% (1.70 times) and 62.4 ± 20.0% at the last follow-up (1.51 times). The mean preoperative local kyphosis angle was 10.5 ± 14.8 and was corrected to 6.0 ± 10.0 at the last follow-up. A slight loss of correction was observed between the postoperative period and the last follow-up; however, there was no clinical significance. CONCLUSIONS: Expandable cages in TPICA may allow easier surgical manipulation for cage insertion around the pedicle entrance, minimizing damage to the fractured vertebral body's end plates while achieving satisfactory height restoration compared to static cages, and may also provide wider indications for TPICA surgery.

Deep learning-driven diagnosis of multi-type vertebra diseases based on computed tomography images.

Background: Osteoporotic vertebral compression fractures (OVCFs) are the most common type of fragility fracture. Distinguishing between OVCFs and other types of vertebra diseases, such as old fractures (OFs), Schmorl's node (SN), Kummell's disease (KD), and previous surgery (PS), is critical for subsequent surgery and treatment. Combining with advanced deep learning (DL) technologies, this study plans to develop a DL-driven diagnostic system for diagnosing multi-type vertebra diseases. Methods: We established a large-scale dataset based on the computed tomography (CT) images of 1,051 patients with OVCFs from Luhe Hospital and used data of 46 patients from Xuanwu Hospital as alternative hospital validation dataset. Each patient underwent one examination. The dataset contained 11,417 CT slices and 19,718 manually annotated vertebrae with diseases. A two-stage DL-based system was developed to diagnose five vertebra diseases. The proposed system consisted of a vertebra detection module (VDModule) and a vertebra classification module (VCModule). Results: The training and testing dataset for the VDModule consisted of 9,135 and 3,212 vertebrae, respectively. The VDModule using the ResNet18-based Faster region-based convolutional neural network (R-CNN) model achieved an area under the curve (AUC), false-positive (FP) rate, and false-negative (FN) rate of 0.982, 1.52%, and 1.33%, respectively, in the testing dataset. The training dataset for VCModule consisted of 14,584 and 47,604 diseased and normal vertebrae, respectively. The testing dataset consisted of 4,489 and 15,122 diseased and normal vertebrae, respectively. The ResNet50-based VCModule achieved an average sensitivity and specificity of 0.919 and 0.995, respectively, in diagnosing four kinds of vertebra diseases except for SN in the testing dataset. In the alternative hospital validation dataset, the ResNet50-based VCModule achieved an average sensitivity and specificity of 0.891 and 0.989, respectively, in diagnosing four kinds of vertebra diseases except for SN. Conclusions: Our proposed DL system can accurately diagnose four vertebra diseases and has strong potential to facilitate the accurate and rapid diagnosis of vertebral diseases.

Risk factor analysis of refracture in the same cemented vertebra after percutaneous kyphoplasty for Kümmell's disease.

OBJECTIVE: The objective of this study was to evaluate the factors that affect refracture in the same cemented vertebra after percutaneous kyphoplasty (PKP) for Kümmell's disease (KD) and establish a risk prediction score. METHODS: A total of 2932 patients who were treated with PKP for KD between January 2019 and December 2021 were retrospectively reviewed. After inclusion and exclusion criteria were applied, 191 patients were included in the study. According to the criteria for refracture, there were 50 patients in the refracture group and 141 patients in the no-refracture group. Twenty-five factors were analyzed. Patient demographics, medical history, imaging data, surgical data, and postoperative management were reviewed. Multivariate logistic regression modeling was used to identify the independent risk factors for refracture. Receiver operating characteristic (ROC) curve analysis was used to assess and establish a risk score system and further predict the risk of refracture. RESULTS: In this study, 50 (26.2%) patients developed a refracture. Through univariate analysis, bone mineral density (BMD) (p < 0.001), compression rate (p = 0.007), classification (i.e., the stages determined by the compression ratios) (p < 0.001), bone cement volume (p < 0.001), volume fraction (p < 0.001), distribution pattern (p = 0.007), non-PMMA endplate contact (p < 0.001), and anti-osteoporosis therapy (p < 0.001) were found to be significant factors for post-cement vertebral refracture after PKP in patients with KD. Three independent risk factors were found to be significant for refracture: small volume fraction, low BMD, and no anti-osteoporosis therapy. One point was assigned for each factor. The incidence rates of refracture in patients with scores of 0, 1, 2, and 3 were 3.7%, 4.4%, 42.0%, and 100%, respectively. The area under the ROC curve for this risk prediction score was 0.888 (p < 0.001), indicating moderate accuracy. CONCLUSIONS: Volume fraction, BMD, and osteoporosis therapy are the main factors influencing the refracture of the same cemented vertebra in KD. On the basis of these factors, the risk prediction score developed in this paper can be used to forecast the incidence of refracture.

Comparison between percutaneous short-segment fixation and percutaneous vertebroplasty in treating Kummell's disease: A minimum 2-year follow-up retrospective study.

BACKGROUND: Percutaneous kyphoplasty (PKP) or percutaneous short-segment fixation (PSSF) is often used to treat Kummell's disease. However, it is not clear which treatment is better for patients. OBJECTIVE: To retrospectively compare the clinical efficacy of PVP and PSSF for the treatment of Kummell's disease. METHOD: 60 patients were involved in this research and the period of follow-up was at least 2 years. 27 of them were treated with PVP (Group I) and the rest who received PSSF (Group II). The visual analog scale (VAS) and radiographic indexes of each participant had been measured preoperatively as well as 1 week, 3 months, and 2 years postoperatively. Additionally, the Oswestry Disability Index (ODI) scores were assessed at the last time point. RESULTS: Comparing the two groups, no statistical significance was found among all parameters preoperatively. The time of operations and blood loss is less in Group I. At each time point after operation, the imaging indices in Group II are lower (P< 0.05). One week after treatments, the VAS scores are lower in Group I, and similarly, 3 months are the same (P< 0.05), while VAS are similar at the last time point. In the aspect of ODI scores, they are lower in Group II during long-term follow-up. CONCLUSION: For the treatment of Kummell's disease, both PVP and PSSF have been found to be effective. PVP can provide rapid pain relief with a shorter operation time. However, in cases with severe kyphosis deformity, PSSF should be given priority.

Biomechanical behaviour of a novel bone cement screw in the minimally invasive treatment of Kummell's disease: a finite element study.

OBJECTIVE: To investigate and evaluate the biomechanical behaviour of a novel bone cement screw in the minimally invasive treatment of Kummell's disease (KD) by finite element (FE) analysis. METHODS: A validated finite element model of healthy adult thoracolumbar vertebrae T12-L2 was given the osteoporotic material properties and the part of the middle bone tissue of the L1 vertebral body was removed to make it wedge-shaped. Based on these, FE model of KD was established. The FE model of KD was repaired and treated with three options: pure percutaneous vertebroplasty (Model A), novel unilateral cement screw placement (Model B), novel bilateral cement screw placement (Model C). Range of motion (ROM), maximum Von-Mises stress of T12 inferior endplate and bone cement, relative displacement of bone cement, and stress distribution of bone cement screws of three postoperative models and intact model in flexion and extension, as well as lateral bending and rotation were analyzed and compared. RESULTS: The relative displacements of bone cement of Model B and C were similar in all actions studied, and both were smaller than that of Model A. The minimum value of relative displacement of bone cement is 0.0733 mm in the right axial rotation of Model B. The maximum Von-Mises stress in T12 lower endplate and bone cement was in Model C. The maximum Von-Mises stress of bone cement screws in Model C was less than that in Model B, and it was the most substantial in right axial rotation, which is 34%. There was no substantial difference in ROM of the three models. CONCLUSION: The novel bone cement screw can effectively reduce the relative displacement of bone cement by improving the stability of local cement. Among them, novel unilateral cement screw placement can obtain better fixation effect, and the impact on the biomechanical environment of vertebral body is less than that of novel bilateral cement screw placement, which provides a reference for minimally invasive treatment of KD in clinical practice.

Prevention of Bone Cement Displacement in Kümmell Disease without Neurological Deficits through Treatment with a Novel Hollow Pedicle Screw Combined with Kyphoplasty.

OBJECTIVE: Displacement of bone cement following percutaneous vertebral augmentation for Kümmell disease (KD) presents a significant concern, resulting in increasing back pain and compromising daily activities. Unfortunately, current literature does not yet establish a validated and minimally invasive surgical intervention for this issue. This study aims to investigate the effects of a novel hollow pedicle screw combined with kyphoplasty (HPS-KP) in preventing bone cement displacement following simply percutaneous kyphoplasty for the management of KD. METHODS: A total of 22 patients (six males, 16 females, averagely aged 77.18 ± 7.63 years) with KD without neurological deficits treated by HPS-KP at the hospital between March 2021 and June 2022 were hereby selected, among which, there were three stage I KD cases, 12 stage II KD cases, and seven stage III KD cases according to Li's classification. Bone mineral density (BMD), spinal X-ray, computed tomography (CT), and magnetic resonance imaging (MRI) were examined before the operation. The operation time, intraoperative blood loss, and postoperative complications were all recorded. The follow-up focused on visual analog scale (VAS) score, Oswestry dysfunction index (ODI), anterior vertebral height (AVH), middle vertebral height (MVH), posterior vertebral height (PVH), wedge-shape affected vertebral Cobb angle (WCA), and bisegmental Cobb angle (BCA). One-way analysis of variance (ANOVA) followed by Bonferroni post-hoc test was employed for performing multiple comparisons in the present study. RESULTS: All patients having received the operation successfully were followed up for more than 8 months (ranging from 8 to 18 months). The operation time, intraoperative blood loss, and BMD (T-score) were 39.09 ± 5.64 min, 14.09 ± 3.98 ml, and - 3.30 ± 0.90 g/cm3 , respectively. Statistically significant differences were observed in the VAS score, ODI, AVH, MVH, and WCA (All p < 0.05), but there was no statistically significant difference in PVH and BCA at different time points (All p > 0.05). During follow-up, five patients suffered from bone cement leakage, and one presented an adjacent vertebral fracture and no bone cement displacement. CONCLUSION: HPS-KP could be safe and effective in the treatment of KD without neurological deficits, effectively relieving the symptoms of patients, restoring partial vertebral height, and preventing the occurrence of bone cement displacement.

Double Vertebrae Kümmell Disease: Five Cases Report and Literature Review.

Kümmell disease (KD) is a complication of osteoporotic vertebral compression fractures. There is a lot of literature on KD, but the reported cases are all single vertebrae. This study reports five double vertebrae KD cases (10 levels) and discusses the possible underlying mechanisms with a literature review. One hundred and thirty vertebrae KD were diagnosed from 2074 osteoporotic vertebral compression fractures patients treated in our hospital between 2015 and 2019. These vertebrae KD were divided into two groups, one-level vertebrae KD (n = 125) and double-level KD (n = 5). The diagnosis of KD is mainly based on the signs of intravertebral vacuum cleft on X-ray or CT scan. Double vertebrae KD cases were classified by using the KD staging system. The analysis was performed on KD to compare age, gender, femoral neck bone mineral density of femoral neck (BMD), vertebrae distribution, Cobb angle, and visual analog scale (VAS) between one-level KD and double-level by t-tests, Welch's t-test, or hypothesis testing. The mean age of the participants in the one-level KD group was 78.69 years, while the mean age in the double-level KD group was 82.4 years. The difference was statistically significant (t = 3.66, p = 0.0004). There were 89 females and 36 males in the one-level KD group, while the double-level KD group had five females and no males. The femoral neck BMD was significantly different between the two groups, with the one-level KD group having a mean BMD of -2.75 and the double-level KD group having a mean BMD of -4.2 (t = 2.99, p= 0.0061). The vertebrae distribution was different between the groups, with the one-level KD group having vertebrae from T7 to L4 and the double-level KD group having vertebrae from T11 to L1. The Cobb angle was also significantly different between the groups, with the one-level KD group having a mean angle of 20.58 and the double-level KD group having a mean angle of 31.54 (t = 6.22, p = 0.0001). Finally, the VAS scores were similar between the two groups, with the one-level KD group having a mean score of 8.63 and the double-level KD group having a mean score of 8.8 (t = 1.35, p = 0.1790). It is concluded that double vertebrae Kümmell disease has special clinical significance due to its potential to cause greater spinal instability and deformity, increased risk of neurological symptoms, more complex surgical management, and greater risk of complications.

Evaluation of the clinical efficacy of the bilateral pedicle cement anchoring technique in percutaneous vertebroplasty for Kümmell disease.

The present study aimed to evaluate the clinical efficacy of the bilateral pedicle cement anchoring technique combined with the postural reduction in percutaneous vertebroplasty (PVP) for Kümmell disease. For this purpose, a retrospective study was performed on 18 patients with Kümmell disease who between January 2018 and June 2021 underwent bilateral pedicle cement anchoring combined with postural reduction in PVP. Pre- and post-operative bone mineral density, injected cement volume, visual analogue scale (VAS) values, Oswestry disability index (ODI) scores, Cobb angle measurements and anterior vertebral height (AVH) were recorded and assessed. The mean follow-up duration was 8.4±1.2 months. The average VAS score decreased from 8.17±0.71 pre-operatively to 1.56±0.62 post-operatively and remained at 2.00±0.91 at the final follow-up visit (P<0.05). The average ODI improved from 86.44±5.5 pre-operatively to 24.33±7.82 post-operatively. Until the last follow-up, the ODI remained at 27.11±8.76 (P<0.05). Similarly, the changes in the Cobb angle and AVH before and after surgery were also statistically significant in the radiological evaluation (P<0.05). During the follow-up, two patients experienced adjacent vertebral fractures. The loosening of cement was not found. Overall, the present study demonstrated that during the treatment of Kümmell disease with PVP, the bilateral pedicle cement anchoring technique combined with postural reduction can achieve good clinical outcomes.

Comparison of percutaneous vertebroplasty and percutaneous vertebroplasty combined with pediculoplasty for Kümmell's disease: a retrospective observational study.

BACKGROUND: To investigate the clinical outcomes of percutaneous vertebroplasty (PVP) versus percutaneous vertebroplasty combined with pediculoplasty (PVP-PP) for Kümmell's disease (KD). METHODS: Between February 2017 and November 2020, 76 patients with KD undergoing PVP or PVP-PP were included in this retrospective study. Based on the PVP whether combined with pediculoplasty, those patients were divided into PVP group (n = 39) and PVP-PP group (n = 37). The operation duration, estimated blood loss, cement volume, and hospitalization stays were recorded and analyzed. Meanwhile, the radiological variations including the Cobb's angle, anterior height of index vertebra, and middle height of index vertebra from X-ray were recorded preoperatively, at 1 days postoperatively and the final follow-up. The visual analogue scale (VAS) and Oswestry disability index (ODI) were also evaluated. Preoperative and postoperative recovery values of these data were compared. RESULTS: The two groups showed no significant difference in demographic features (p > 0.05). The operation time, intraoperative blood loss, and time of hospital stay revealed no sharp statistical distinctions either (p > 0.05), except that PVP-PP used more bone cement than PVP (5.8 ± 1.5 mL vs. 5.0 ± 1.2 mL, p < 0.05). The anterior and middle height of vertebra, Cobb's angle, VAS, and ODI was observed a little without significant difference between the two groups before and 1 days postoperatively (p > 0.05). Nevertheless, ODI and VAS scores decreased significantly in the PVP-PP group than in the PVP group at follow-up (p < 0.001). The PVP-PP group exhibited a slight amelioration in Ha, Hm, and Cobb's angle when compared to the PVP group, displaying statistical significance (p < 0.05). No significant disparity in cement leakage was observed between the PVP-PP and PVP groups (29.4% vs. 15.4%, p > 0.05). It is worth noting that the prevalence of bone cement loosening displayed a remarkable decrement within the PVP-PP group, with only one case recorded, as opposed to the PVP group's seven cases (2.7% vs. 17.9%, p < 0.05). CONCLUSIONS: Both PVP-PP and PVP can relieve pain effectively in patients with KD. Moreover, PVP-PP can achieve more satisfactory results than PVP. Thus, compared with PVP, PVP-PP is more suitable for KD without neurological deficit, from a long-term clinical effect perspective.