Comparison of Percutaneous Kyphoplasty and Bone Cement-Augmented Short-Segment Pedicle Screw Fixation for Management of Kümmell Disease

Percutaneous kyphoplasty with or without posterior pedicle screw fixation for the management of severe osteoporotic vertebral compression fractures with nonunion

OBJECTIVE

To assess the radiographic outcomes, clinical outcomes and complications of percutaneous kyphoplasty (PKP) with and without posterior pedicle screw fixation (PPSF) in the treatment of severe osteoporotic vertebral compression fractures (sOVCF) with nonunion.

METHODS

This study involved 51 patients with sOVCF with nonunion who underwent PKP or PPSF + KP. The operation time, intraoperative blood loss, volume of injected bone cement, operation costs and hospital stays were all recorded. In addition, the Visual Analogue Scale (VAS) and the Oswestry Disability Index (ODI) were assessed separately for each patient before and after surgery.

RESULTS

Compared with the PPSF + KP group, the PKP group had shorter operation time, less intraoperative blood loss, shorter hospital stays and fewer operation costs. However, cobb's angle improvement (13.4 ± 4.3° vs. 21.4 ± 5.3°), VWR improvement ratio (30.4 ± 11.5% vs. 52.8 ± 12.7%), HA (34.9 ± 9.0% vs. 63.7 ± 7.6%) and HM (28.4 ± 11.2% vs. 49.6 ± 7.7%) improvement ratio were all higher in PPSF + KP group than that in PKP group. In addition, the ODI index and VAS score in both groups were significantly decreased at the postoperative and final follow-up. PKP group's postoperative VAS score was significantly lower than that in PPSF + KP group, but there was no statistically significant difference in VAS score at the last follow-up.

CONCLUSION

PKP and PPSF + KP can both effectively relieve the pain associated with sOVCF with nonunion. PPSF + KP can achieve more satisfactory vertebral reduction effects compared to PKP. However, PKP was less invasive and it has more advantages in shortening operation time and hospital stay, as well as decreasing intraoperative blood loss and operation costs.

Percutaneous short segmental fixation combined with bone cement augmentation for stage III Kümmell's disease without nerve deformity

The objective of this study was to evaluate the safety and efficacy of percutaneous pedicle screw fixation combined with bone cement augmentation in the management of stage III Kümmell disease without nerve deformity. A retrospective analysis was conducted on 17 patients diagnosed with stage III Kümmell disease without nerve deformity, who underwent treatment with percutaneous pedicle screw fixation combined with bone cement augmentation between April 2019 and 2022. Preoperative, postoperative, and final follow-up clinical outcome measures were collected, including Visual Analog Scale scores and Oswestry Disability Index scores. Additionally, lateral radiography was used to measure the Cobb angle and height of the anterior border of the affected vertebral body. Operative time, volume of injected bone cement, intraoperative cement leakage, and other complications were recorded. All patients underwent successful surgery, resulting in significant reductions in Visual Analog Scale scores, Oswestry Disability Index scores, and Cobb angle postoperatively; meanwhile there was a significant increase in height of the anterior border of the affected vertebral body. No major complications occurred during the follow-up period. In conclusion, percutaneous pedicle screw short-segment fixation combined with bone cement augmentation appears to be an effective surgical option for treating stage III Kümmell disease without nerve deformities.

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.

Biomechanical evaluation of a novel minimally invasive pedicle bone cement screw applied to the treatment of Kümmel's disease in porcine vertebrae

Background and objective: Treatment of Kümmel's Disease (KD) with pure percutaneous kyphoplasty carries a greater likelihood of bone cement displacement due to hardened bone and defect of the peripheral cortex. In this study, we designed a novel minimally invasive pedicle bone cement screw and evaluate the effectiveness and safety of this modified surgical instruments in porcine vertebrae. Methods: 18 mature porcine spine specimens were obtained and soaked in 10% formaldehyde solution for 24 h. 0.5000 mmol/L EDTA-Na2 solution was used to develop in vitro osteoporosis models of porcine vertebrae. They were all made with the bone deficiency at the anterior edge of L1. These specimens were randomly divided into 3 groups for different ways of treatment: Group A: pure percutaneous kyphoplasty (PKP) group; Group B: unilateral novel minimally invasive pedicle bone cement screw fixation combined with PKP group; Group C: bilateral novel minimally invasive pedicle bone cement screw fixation combined with PKP group. The MTS multi-degree of freedom simulation test system was used for biomechanical tests, including axial loading of 500 N pressure, range of motion (ROM) in flexion, extension, left/right lateral bending, and left/right axial rotation at 5 Nm, and the displacement of bone cement mass at maximum angles of 5° and 10°. Result: The three groups were well filled with bone cement, no leakage or displacement of bone cement was observed, and the height of the vertebrae was higher than pre-operation (p < 0.05). In the left/right axial rotation, the specimens were still significantly different (p < 0.05) from the intact specimens in terms of ROM after PKP. In other directions, ROM of all group had no significant difference (p < 0.05) and was close to the intact vertebrae. Compared with PKP group, the relative displacement of bone cement in groups B and C was smaller (p < 0.05). Conclusion: In the in vitro animal vertebral models, the treatment of KD with the placement of novel pedicle minimally invasive bone cement screw combined with PKP can effectively restore the vertebral height, improve the stability of the affected vertebra and prevent the displacement of bone cement. Biomechanically, there is no significant difference between bilateral and unilateral fixation.

Biomechanical analysis of a novel bone cement bridging screw system for the treatment of Kummell disease: a finite element analysis

When bone cement is used to strengthen the vertebrae in patients with Kummell disease (KD), loosening and displacement of cement are common complications that can cause poor results. We developed a bone cement bridging screw system to avoid this complication. This three-dimensional finite element study aims to analyze the biomechanical properties of the novel bridging screw system and compare it to single vertebroplasty and vertebroplasty combined with pediculoplasty. After the effective establishment of a KD three-dimensional finite element model, the stability of the bone cement in the five treatment methods was analyzed and compared on four aspects. According to the calculation results of the maximum von Mises stress of bone cement and the relative displacement ratio of bone cement, it was determined that the stability of the bone cement was significantly improved when combined with the bridging screw system or pediculoplasty. In addition, according to the calculation results of the maximum von Mises stress of the inferior endplate of T12 and the displacement load ratio of the bone cement, we further found that after using the bridging screw system, the bone cement in the vertebral body has the best stability, and the risk of bone cement loosening or displacement is the lowest. In conclusion, for treating KD with bone cement augmentation, the bone cement bridging screw system combined with vertebroplasty has better stability and safety than ordinary single vertebroplasty and vertebroplasty combined with pediculoplasty. This treatment approach has the most robust ability to avoid loosening and displacement of bone cement.

Efficacy and Safety of Posterior Long-Segment Fixation Versus Posterior Short-Segment Fixation for Kummell Disease: A Meta-Analysis

Purpose

Posterior short-segment fixation (SSF) and long-segment fixation (LSF) are two methods for the treatment of Kummell disease, but the safety and effectiveness of these two surgical methods still lack adequate medical evidence. This study aimed to evaluate the two methods.

Methods

Database searches for randomized controlled trials, case-control studies, and cohort studies of posterior SSF and posterior LSF in the treatment of Kummell disease were performed. After the document quality was evaluated with the Newcastle-Ottawa Quality Assessment Scale, a meta-analysis was carried out.

Results

Meta-analysis revealed that the operation time and intraoperative blood loss in the LSF group were higher than those in the SSF group [MD = −18.17, 95% CI (−30.31, −6.03), z = 2.93, P = .003; MD = −82.07, 95% CI (−106.91, −57.24], z = 6.48, P < .00001). The postoperative last follow-up local kyphosis angle in the SSF group was greater than that in the LSF group (MD = 3.18, 95% CI [.56, 5.81], z = 2.38, P = .02), and there were no significant differences in perioperative complications, bone cement leakage rate, incidence of adverse events during follow-up, postoperative follow-up visual analog scale, postoperative Oswestry dysfunction index, and postoperative immediate local kyphosis angle between the two groups (P > .05).

Conclusion

SSF and LSF are effective and safe for the treatment of Kummell disease. SSF can reduce the operation time and intraoperative bleeding; LSF can better maintain the long-term stability of kyphosis. The methods should be evaluated by clinicians according to the individual situation of the patients.

Percutaneous Kyphoplasty Versus Percutaneous Vertebroplasty for Neurologically Intact Osteoporotic Kümmell's Disease: A Systematic Review and Meta-Analysis

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVE

Percutaneous vertebroplasty (PVP) and percutaneous kyphoplasty (PKP) are minimally invasive techniques widely used for the treatment of neurologically intact osteoporotic Kümmell's disease (KD), but which treatment is preferable remains controversial. Therefore, this study aimed to shed light on this issue.

METHODS

Six databases were searched for all relevant studies based on the PRISMA guidelines. Two investigators independently conducted a quality assessment, extracted the data and performed all statistical analyses.

RESULTS

Eight studies encompassing 438 neurologically intact osteoporotic KD patients met the inclusion criteria. Compared to PVP, PKP was associated with greater improvement in the short- and long-term Cobb angle [SMD = -0.37, P = 0.007; SMD = -0.34, P = 0.012], short-term anterior vertebral height [SMD = 0.43, P = 0.003] and long-term middle vertebral height [SMD = 0.57, P = 0.012] and a lower cement leakage rate [SMD = 0.50, P = 0.003] but produced more consumption (cement injection volume, operative time, fluoroscopy times, intraoperative blood loss and operation cost). However, there were no differences between the 2 procedures in the short- and long-term VAS and ODI scores, long-term anterior vertebral height, overall complications or new vertebral fractures.

CONCLUSIONS

Both procedures are equally effective for neurologically intact KD in terms of the clinical outcomes, with the exception of a lower cement leakage risk and better radiographic improvement for PKP but greater resource consumption. Based on the evidence available, good clinical judgment should be exercised in the selection of patients for these procedures.

Does segmental artery occlusion cause intravertebral cleft following osteoporotic vertebral fracture: a prospective magnetic resonance angiography study

Background

The avascular necrosis (AVN) hypothesis of intravertebral cleft (IVC) formation in osteoporotic vertebral fracture (OVCF) has received increasing attention. The aim of this article is to detect whether the segmental artery occlusion causes the IVC following OVCF.

Methods

Between December 2019 and April 2020, 44 OVCF patients with 46 fracture levels were prospectively enrolled and the vertebral segmental arteries were evaluated by magnetic resonance angiography (MRA). The artery conditions were divided into patent, narrow and occluded. The lesion segmental occlusion rate (LSOR) and the total occlusion rate (TOR) were calculated. The association of segmental artery occlusion and IVC formation was assessed.

Results

LOSR was 15.34% and TOR was 15.12%. The segmental arteries of the unfractured vertebrae had a higher occlusion rate at thoracolumbar levels than at non-thoracolumbar levels. There was no significant difference between the IVC group and the non-IVC group in the fractured levels artery occlusion rate (20.24 ± 28.08 vs 9.78 ± 19.56, P = 0.156) or the total segmental arteries occlusion rate (13.83 ± 12.04 vs 11.57 ± 9.25, P = 0.476).

Conclusions

In patients with vertebral osteoporotic fracture, segmental artery occlusion is not associated with the development of intravertebral cleft.

Vertebral augmentation plus short-segment fixation versus vertebral augmentation alone in Kümmell's disease: a systematic review and meta-analysis

Osteoporotic vertebral compression fractures of the thoracolumbar spine can progress to Kümmell's disease, an avascular vertebral osteonecrosis. Vertebral augmentation (VA)-vertebroplasty and/or kyphoplasty-is the main treatment modality, but additional short-segment fixation (SSF) has been recommended concomitant to VA. The aim is to compare clinical and radiological outcomes of VA + SSF versus VA alone. Systematic review, including comparative articles in Kümmell's disease, was performed. This study assessed the following outcome measurements: visual analog scale (VAS), Oswestry Disability Index (ODI), anterior vertebral height (AVH), local kyphotic angle (LKA), operative time, blood loss, length of stay, and cement leakage. Six retrospective studies were included, with 126 patients in the VA + SSF group and 152 in VA alone. Pooled analysis showed the following: VAS, non-significant difference favoring VA + SSF: MD -0.61, 95% CI (-1.44, 0.23), I² 91%, p = 0.15; ODI, non-significant difference favoring VA + SSF: MD -9.85, 95% CI (-19.63, -0.07), I² 96%, p = 0.05; AVH, VA + SSF had a non-significant difference over VA alone: MD -3.21 mm, 95% CI (-7.55, 1.14), I² 92%, p = 0.15; LKA, non-significant difference favoring VA + SSF: MD -0.85°, 95% CI (-5.10, 3.40), I² 95%, p = 0.70. There were higher operative time, blood loss, and hospital length of stay for VA + SSF (p < 0.05), but with lower cement leakage (p < 0.05). VA + SFF and VA alone are effective treatment modalities in Kümmell's disease. VA + SSF may provide superior long-term results in clinical and radiological outcomes but required a longer length of stay.

Long-term efficacy and safety of bone cement-augmented pedicle screw fixation for stage III Kümmell disease

This study aimed to evaluate the efficacy and safety of bone cement-augmented pedicle screw fixation for stage III Kümmell disease. Twenty-five patients with stage III Kümmell disease who received bone cement-augmented pedicle screw fixation at the First Affiliated Hospital of Guangzhou University of Chinese Medicine between June 2009 and December 2015 were enrolled. All patients were females with a history of osteoporosis. The vertebral Cobb angle (V-Cobb angle), the fixed segment Cobb Angle (S-Cobb angle), pelvic parameters, visual Analogue Scale (VAS) score, and Oswestry Disability Index (ODI) were assessed preoperatively, postoperatively and at the final follow-up. Complications, loosening rate, operation time, and intraoperative bleeding were recorded. The average lumbar vertebral density T-value was − 3.68 ± 0.71 SD, and the average age was 71.84 ± 5.39. The V-Cobb angle, S-Cobb angle, and Sagittal Vertical Axis (SVA) were significantly smaller postoperatively compared to the preoperative values. The VAS and ODI at 1 month after surgery were 3.60 ± 1.00 and 36.04 ± 6.12%, respectively, which were both significantly lower than before surgery (VAS: 8.56 ± 1.04, ODI: 77.80 ± 6.57%). Bone cement-augmented pedicle screw fixation is a safe and effective treatment for stage III Kümmell disease. It can effectively correct kyphosis, restore and maintain sagittal balance, and maintain spinal stability.

Clinical Observations of Kümmell Disease Treatment Through Percutaneous Fixation Combined with Vertebroplasty

OBJECTIVE

To explore the safety and efficacy of percutaneous pedicle screw fixation combined with vertebroplasty for the treatment of stage III Kümmell disease.

METHODS

The clinical data and follow-up results of 22 patients with Kümmell disease who were admitted to our department from 2014 to 2018 were analyzed. There were 14 females and eight males, and the Age range was 58-81 years. All patients were followed up for 24 months. The treatment method was percutaneous pedicle screw fixation combined with vertebroplasty. The patient general information such as age, gender, bedrest time and location of fracture vertebrae were recorded. The clinical symptoms and imaging data of visual analogue scale (VAS), bone cement leakage, Oswestry Disability Index (ODI), Cobb angle, anterior, middle and posterior height of the diseased vertebral body, and complications were recorded before operation and during follow-up.

RESULTS

For patients enrolled, no bone cement leakage was observed during the operation; no patients developed infections after operation. The operation was safe and resulted in a short bedrest time. The VAS score and ODI index at 3 and 24 months postoperative (2.86 ± 0.83, 31.68% ± 6.21%; 3.0 ± 0.82, 32.78% ± 6.05%) were significantly lower than that recoded preoperatively (7.59 ± 0.59, 71.5% ± 8.84%) (P < 0.05). Additionally, there was no significant difference between the records at 3 and 24 months after operation (P > 0.05). Imaging data showed that the bone cement and screws were in good position and did not move during postoperative and follow-up. The anterior, middle and posterior height of the diseased vertebral body measured 2 days after surgery (23.46 ± 4.72, 23.12 ± 3.05, 25.81 ± 2.22) and at last follow-up (20.83 ± 4.48, 21.78 ± 2.74, 24.74 ± 1.93) were higher than that recorded preoperatively (13.08 ± 4.49, 12.93 ± 3.53, 19.32 ± 2.73) (P < 0.05), and the Cobb angle measured 2 days and 24 months after operation (9.57 ± 4.63, 10.68 ± 3.97) were lower than that recorded preoperatively (28.24 ± 8.95) (P < 0.05), and no significant difference was found between the values recorded at 2 days and 24 months after operation (P > 0.05). Follow-up for 24 months, there was no re-fracture of the diseased vertebrae and internal fixation loosening, but two cases of adjacent vertebral refracture complications occurred, and the effect was good after PVP treatment.

CONCLUSION

Short-segment percutaneous pedicle screw fixation combined with vertebroplasty in the treatment of stage III Kümmel disease can effectively restore the height of the diseased vertebrae, kyphosis correction, reduce trauma, prevent the diseased vertebral body from collapsing again, and effectively improves clinical symptoms.

Posterior Fixation Combined with Vertebroplasty or Vertebral Column Resection for the Treatment of Osteoporotic Vertebral Compression Fractures with Intravertebral Cleft Complicated by Neurological Deficits

Purpose

The aim of the current study was to evaluate the relative benefits of posterior fixation combined with vertebroplasty (PFVP) or vertebral column resection (PVCR) for osteoporotic vertebral compression fractures (OVCFs) with intravertebral cleft (IVC) complicated by neurological deficits.

Methods

From June 2010 to January 2015, 45 consecutive patients suffering OVCFs with IVC and spinal cord injuries were treated with PFVP or PVCR in our department. The visual analogue scale (VAS) score, anterior vertebral height (AVH), posterior vertebral height (PVH), local kyphotic angle (LKA), and neurologic function were evaluated and compared, and the operative duration, blood loss, and complications were also recorded.

Results

They all achieved excellent pain relief, vertebral height recovery, and kyphosis correction one month after surgery, and no significant differences existed between the two groups. No significant differences were observed between the 1-month postoperative and final follow-up VAS, AVH, and LKA values in the PVCR group (P > 0.05), while AVH and LKA worsened in the PFVP group at the final follow-up (P < 0.05). Similarly, the initial improvements in VAS scores decreased over time (P < 0.05). Neurologic function improved in both groups, and no significant differences were observed between the 2 groups either preoperatively or postoperatively (P > 0.05). The blood loss and operative duration were significantly lower in the PFVP group than those in the PVCR group (P < 0.05).

Conclusion

Compared with PVCR, PFVP had equivalent short-term clinical outcomes with less blood loss and operative duration which can be very beneficial for treating elderly patients with extreme comorbidities in this condition. However, based on the long-term efficacy of pain relief, vertebral height maintenance, and deformity correction, PVCR is a more reasonable choice.

Fabrication of PLLA/C3S Composite Membrane for the Prevention of Bone Cement Leakage

Kyphoplasty is an important treatment for stabilizing spine fractures due to osteoporosis. However, leakage of polymethyl-methacrylate (PMMA) bone cement during this procedure into the spinal canal has been reported to cause many adverse effects. In this study, we prepared an implantable membrane to serve as a barrier that avoids PMMA cement leakage during kyphoplasty procedures through a hybrid composite made of poly-l-lactic acid (PLLA) and tricalcium silicate (C₃S), with the addition of C₃S into PLLA matrix, showing enhanced mechanical and anti-degradation properties while keeping good cytocompatibility when compared to PLLA alone and most importantly, when this material design was applied under standardized PMMA cement injection conditions, no posterior wall leakage was observed after the kyphoplasty procedure in pig lumbar vertebral bone models. Testing results assess its effectiveness for clinical practice.

Novel Surgical Strategy for Treating Osteoporotic Vertebral Fractures with Cord Compression

Objectives

Treatment for osteoporotic vertebral fracture (OVF) with cord compression is challenging and it usually requires surgical interventions to decompress nerves and restore spinal sequences. To describe a novel surgical strategy for treating OVFs with cord compression.

Methods

This is a single‐center retrospective analysis. The inclusion criteria were Frankel grade C‐E, single level T₁₀‐L₂. Between January 2008 and December 2016, a total of 56 OVF patients (47 females and nine males, with an average age of 72 years (66–88 years), comprising of eight grade C, 23 grade D, and 25 grade E patients) were enrolled. The treatment algorithm included preoperative evaluation by MRI, extension CT, and radiography to classify the OVFs as type 1.1 (reducible, stable; n = 13), type1.2 (reducible, unstable; n = 16), type 2 (irreducible; n = 19) or type 2M (modifier; n = 8). Vertebroplasty (VP)/kyphoplasty (KP) was applied in type 1.1. VP/KP with posterior fixation and posterolateral fusion was applied in type 1.2. And additional laminectomy/osteotomy was used in type 2, except in a modifier group (2M) where same procedure as applied for type 1.2 was used. VAS, ODI, Cobb angle, Frankel functional grade, and complications were recorded.

Results

Thirteen cases were classified as type 1.1, 16 cases as type 1.2, 19 cases as type 2, and eight cases as type 2M. The follow‐up period was 38.9 months (range, 24–108 months). All patients were followed‐up in at least 24 months, in which time four patients died, two patients were lost at the last follow‐up, and 50 patients completed the full study. The total VAS and ODI improved from 8 (7, 9) and 75.5% (67.2%, 80.0%) preoperatively to 2 (1, 3) and 31% (24.0%, 37.0%) on conclusion, respectively (P < 0.01). The local kyphotic angle was corrected from 22.3° (17.1°, 33. 8°) preoperatively to 10.4° (6.4°, 15.3°) on conclusion (P < 0.01). Twenty‐three patients had achieved neurological recovery on conclusion (42E, 8D, P < 0.01). Asymptotic cement leakage was observed in 17/56 cases (30.4%), 6/56 in the affected vertebra (10.7%), and 24/330 in the screw trajectory (7.3%). At 2 years postoperatively, 11 new VFs had occurred in nine patients (16.1%), including VFs in nine adjacent segments that all occurred within 1 year after surgery. No cement migration or implant failure was noted.

Conclusion

The novel surgical strategy for treating OVFs with cord compression consists of the most tailored and least invasive treatment for each patient. The positive mid‐ and long‐term clinical and radiological outcomes observed could represent a step forward in devising the proposed algorithm.

Vitamin D Deficiency/Insufficiency Is Associated with Risk of Osteoporotic Thoracolumbar Junction Vertebral Fractures

Background

The association between serum vitamin D level and vertebral fracture (VFx) remains controversial. The purpose of this study was to determine whether serum 25-hydroxy vitamin D (25(OH)D) level is associated with osteoporotic thoracolumbar junction VFx in elderly patients.

Material/Methods

From Jan 2013 to Dec 2017, this retrospective case-control study included 534 patients with primary osteoporotic thoracolumbar junction VFx (T10–L2) and 569 elderly orthopedic patients with back pain (without osteoporotic VFx) as controls. Serum 25(OH)D levels were measured and the association with osteoporotic VFx was analyzed. Other clinical data, including BMI, comorbidities, and bone mineral density (BMD), were also collected and compared between these 2 groups.

Results

It was shown that 25(OH)D levels were significantly lower in patients with T10–L2 VFx than in control patients. Among 534 VFx patients, 417 (78.1%) patients showed grade 2–3 fracture. Serum 25(OH)D levels were significantly related to affected vertebral numbers and VFx severities. The VFx risk was 28% lower (OR=0.72, 95% CI 0.62–0.83) per increased SD in serum 25(OH)D. Compared with the 1^st quartile (mean 25(OH)D: 29.67±6.18 nmol/L), the VFx risk was significantly lower in the 3^rd (mean 25(OH)D: 60.91±5.12nmol/L) and 4^th quartiles (mean 25(OH)D: 103.3±44.21nmol/L), but not in the 2^nd quartile (mean 25(OH)D: 45.40±3.95 nmol/L). In contrast, the VFx risk was significantly increased in the 1^st quartile (OR=1.87, 95% CI 1.42–2.45) compared with the 2^nd–4^th quartiles.

Conclusions

Vitamin D deficiency/insufficiency was associated with risk of osteoporotic thoracolumbar junction vertebral fractures in elderly patients.

Safety of Cement Distribution Patterns in Metastatic Vertebral Tumors: A Retrospective Study

Background

Kyphoplasty (KP) is a palliative treatment for patients with metastatic vertebral tumors. The distribution pattern of cement affects safety and efficacy. The distribution pattern of cement has not been previously reported for patients with metastatic vertebral tumors.

Material/Methods

From January 2013 to December 2017, patients with metastatic vertebral tumors who met our criteria were divided into cement fusion (n=91) and separation (n=97) groups. Visual analogue scale (VAS) and middle vertebral height (MVH) were evaluated preoperatively, postoperatively, and 1 year after surgery. Spinal Instability Neoplastic Score, fluoroscopy time, operation time, cement volume, cement leakage, and vertebral fractures were recorded and evaluated.

Results

Compared with the fusion group, the separation group had significantly different (P<0.001) operation time, fluoroscopy time, and cement volume. Compared with preoperative status, VAS and MVH were significantly improved 3 days postoperatively and 1 year postoperatively in both groups (P<0.001). The difference in cement leakage between the 2 groups (P<0.05) and in the number of adjacent vertebral fractures between the 2 groups (P<0.05) were significant.

Conclusions

The distribution patterns of the bone cement had a good analgesic effect and preventive effect on vertebral collapse. However, the separation of bone cement may be safer.

Analysis of percutaneous kyphoplasty or short-segmental fixation combined with vertebroplasty in the treatment of Kummell disease

Background

In recent years, short segment internal fixation combined with vertebroplasty (SSF + VP) has provided a new option for the treatment of Kummell disease (KD). The purpose of this study is to evaluate the efficacy of percutaneous kyphoplasty (PKP) and SSF + VP, to provide evidence-based medical support for the decision-making process when treating KD patients without neurological deficits.

Methods

Databases including MEDLINE (PubMed) and EMBASE (Ovid) (1947 to April 6, 2019) were searched for PKP and short-segmental fixation combined with vertebroplasty (SSF + VP) to treat Kummell disease in randomized controlled trials (RCTs) or cohort studies. Two investigators independently evaluated the eligibility of the studies retrieved from the databases based on the predetermined selection criteria. The postoperative evaluation indexes included operation time, bleeding volume, visual analog scale (VAS) score, Oswestry Disability Index (ODI) score, local vertebral Cobb angle, and cement leakage. When the data were significant, a random-effects model was used for analysis. In contrast, when the results showed no statistical heterogeneity, a fixed-effects model was used to estimate the overall effect sizes.

Results

Three retrospective case-control studies were included in the final analysis. The differences in the bleeding volume and operation time were statistically significant, and the combined weighted mean differences (WMDs) (95% CI) were − 0.204.46 (− 210.97, − 197.93) and − 98.98 (− 141.63, 56.32), respectively.

The combined data showed that the differences in VAS score, ODI score, local vertebral Cobb angle, and cement leakage were not statistically significant.

Conclusions

This analysis demonstrates that the PKP and SSF + VP methods are safe and effective in treating Kummell disease patients without neurological symptoms. However, PKP can shorten the operation time and reduce the volume of blood loss.

Efficacy of unilateral transverse process-pedicle and bilateral puncture techniques in percutaneous kyphoplasty for Kummell disease

In the present study, the efficacy of unilateral transverse process-pedicle and bilateral puncture techniques in percutaneous kyphoplasty (PKP) for Kummell disease was compared. Between March 2015 and June 2017, 63 patients with Kummell disease were recruited and underwent PKP with two different puncture techniques: A total of 38 patients were treated by unilateral transverse process-pedicle PKP and 25 patients were treated by bilateral PKP. The operative time, intra-operative fluoroscopy time, volume of bone cement injection and bone cement leakage were recorded. Prior to surgery and 1 day post-surgery, the visual analogue scale (VAS) pain score and Oswestry disability index (ODI) were determined, and the vertebral body height and Cobb angle were measured. The results indicated that the incidence of bone cement leakage in the unilateral group was similar with the bilateral group (15.79% vs. 16.00%), with no statistically significant difference between the two groups. None of the patients in the two groups had any obvious damage of the spinal cord. The operative time, intra-operative fluoroscopy time and volume of bone cement injection in the unilateral group were lower than those in the bilateral group. A chest X-ray examination at 1 day post-surgery revealed no pulmonary embolism in the two groups. The VAS score, ODI, vertebral body height and Cobb angle were significantly improved in the unilateral and bilateral groups at 1 day post-surgery and at the last follow-up (12 months post-surgery) as compared with these parameters prior to surgery. In conclusion, the unilateral transverse process-pedicle and bilateral puncture techniques in PKP exhibited good efficacy as a treatment for Kummell disease. The operative time, intra-operative fluoroscopy time and volume of bone cement injection were lower in the unilateral group.