Posterior decompression and short segmental pedicle screw fixation combined with vertebroplasty for Kümmell's disease with neurological deficits

Global trends and frontiers of research on Kümmell's disease: A bibliometric analysis

The prevalence of Kümmell's disease (KD) has been increasing due to the aging population and the rise of osteoporotic vertebral compressibility fractures. As a result, there has been a growing concern about this condition. Despite the rapid advancements in its related research fields, the current research status and hotspot analysis of KD remain unclear. Therefore, our goal was to identify and analyze the global research trends on KD using bibliometric tools. All KD data were obtained from the Web of Science Core Collection. The information of research field was collected, including title, author, institutions, journals, countries, references, total citations, and years of publication for further analysis. From 1900 to 2022, a total of 195 articles and 1973 references have been published in this field, originating from 27 countries/regions and 90 journals, with China leading the contributions. The most significant institutional and author contributions come from Soochow University and Kim, HS, respectively. The journal with the highest number of published research and total citation frequency is Spine. The latest research focuses in this field include "risk factor," "osteoporotic vertebral compression fracture," "pedicle screw fixation," "percutaneous vertebroplasty," and "bone cement," and should be closely monitored. Additionally, we have conducted a comprehensive analysis of the 50 most-cited articles in KD, providing a valuable list of articles to guide clinical decision-making and future research for clinicians and researchers. In recent years, there has been a significant increase in scientific research on KD. Future research in KD is likely to focus on surgical treatment, risk factors, and complications.

'Armed kyphoplasty' with posterior stabilization avoids corpectomy in complex thoracolumbar spine fractures: a case series

BACKGROUND

Complex thoracolumbar fractures require reduction and stabilization. Posterior instrumentation alone and standard cement augmentation may represent undertreatment, while corpectomy has significant morbidity. In a series of unstable thoracolumbar fractures, we assessed the feasibility, safety, and results of 'armed kyphoplasty' (AKP) and surgical posterior stabilization (PS).

METHODS

A total of 24 consecutive patients were treated with combined AKP and PS. Minimally invasive and open surgery techniques were used for PS. AKP was performed with C-arm or biplane fluoroscopic guidance, and screws were placed under navigation or fluoroscopic guidance. A postoperative CT scan and standing plain films were obtained. Patients were followed up according to clinical standards. Kyphosis correction (measured with regional Cobb angle), pain (measured with the Numeric Rating Scale), neurological status (measured with Frankel grade) were assessed.

RESULTS

A total of 25 fractures of neoplastic (40%), traumatic (32%), and osteoporotic (28%) nature were treated. Open surgery and minimally invasive techniques were applied in 16/24 and 8/24 patients, respectively. Decompressive laminectomy was performed in 13 cases. No intraprocedural complications occurred. Two patients (8%) died due to underlying disease complications and three complications (12%) required re-intervention (one surgical site infection, one adjacent fracture, and one screw pull-out) in the first month. The mean Cobb angle was 20.14±6.19° before treatment and 11.66±5.24° after treatment (P<0.0001). No re-fractures occurred at the treated levels.

CONCLUSIONS

Combined AKP and PS is feasible and effective in the treatment of complex thoracolumbar fractures of all etiologies. AKP avoided highly invasive corpectomy. Anterior and posterior support ensured stability, preventing implant failure and re-fracture. The complication rate was low compared with more invasive traditional 360° open surgical approaches.

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.

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.

Biomechanical analysis of a novel bone cement bridging screw system combined with percutaneous vertebroplasty for treating Kummell's disease

Kummell's Disease (KD) was originally proposed by Dr. Hermann Kummell in 1891 as a type of delayed posttraumatic vertebral collapse, which is a clinical phenomenon. The purpose of this experiment is to compare the strength of bone cement and the novel bone cement bridging screw in the treatment of thoracolumbar Kummell disease (KD) with other treatment methods. Thirty sheep spine specimens were selected. T12 to L2 segments were selected, and a KD intravertebral vacuum cleft model was made at the L1 segment. According to the ways of cement filling, the specimens were divided into percutaneous vertebroplasty (PVP), PVP combined with unilateral percutaneous pediculoplasty (PPP), PVP combined with bilateral PPP, unilateral novel bone cement bridging screw system combined with PVP, and bilateral cement bridging screw system combined with PVP groups. There were two experiments: three-dimensional biomechanical strength test and axial compression test. In the three-dimensional biomechanical strength test, we measured the strength of bone cement in specimens under six motion states, including flexion, extension, left bending, right bending, and left and right axial rotations. In the axial compression test, we detected the maximum axial pressure that the bone cement could withstand when it was under pressure until the bone cement was displaced. The unilateral or bilateral novel bone cement bridging screw with PVP groups had the best strength under flexion, extension, left bending, right bending, and had better biomechanical strength, with a significant difference from the other three groups (p < 0.05). There was no significant difference between the unilateral or bilateral novel bone cement bridging screw with PVP groups (p > 0.05). Unilateral and bilateral novel bone cement bridging screw could achieve similar bone cement strength. Compared with the other three groups, the unilateral or bilateral novel bone cement bridging screw with PVP groups are higher 136.35%, 152.43%; 41.93%, 51.58%; 34.37%, 43.50% respectively. The bilateral novel bone cement bridging screw with PVP could bear the largest pressure under vertical force. To conclude, the novel bone cement bridging screw can increase the strength of bone cement and avoid the loosening and displacement of bone cement in the treatment of KD of the thoracolumbar spine.

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.

Comparison of Outcomes Between Percutaneous Vertebroplasty and Percutaneous Kyphoplasty for the Treatment of Kümmell's Disease: A Meta-Analysis

STUDY DESIGN

A meta-analysis.

OBJECTIVE

The aim is to compare the efficacy of percutaneous vertebroplasty (PVP) and percutaneous kyphoplasty (PKP) in treating Kümmell's disease (KD) without neurological deficits.

SUMMARY OF BACKGROUND DATA

PVP and PKP are routine methods for the treatment of KD without neurological deficits; however, whether PVP or PKP is superior is a matter of debate.

MATERIALS AND METHODS

According to the Cochrane Handbook for Systematic Reviews of Interventions, PubMed, Embase, the Cochrane Library, and Web of Knowledge were searched for eligible randomized controlled trials or cohort studies. Two authors independently collected data and assessed the methodologic quality of the included studies. Intraoperative and postoperative clinical outcomes, cement leakage, refracture rate, and the costs during hospitalization were evaluated.

RESULTS

Five observational studies comparing 119 PVP and 128 PKP patients were included in qualitative and quantitative reviews. All of the included s studies had evidence of good quality, as assessed by the Newcastle-Ottawa scale. On the basis of meta-analysis the operation time [weighted mean difference: -10.65; 95% confidence interval (95% CI): -11.94 to -9.35; P <0.00001] and hospitalization cost (weighted mean difference: -2.38; 95% CI: -2.87 to -1.89; P <0.00001) were less for PVP, while the cement leakage rate was lower for PKP (odds ratio: 3.03; 95% CI: 1.58-5.82; P <0.001). Together, the data indicated that the differences in cement volume, visual analog scale score, Oswestry disability index score, Cobb angle, anterior vertebral height, and refracture rate were not significantly different.

CONCLUSION

The findings of this study suggest that PVP and PKP are safe and effective for the treatment of KD. PVP required less operative time and was more affordable, but PKP was superior given the lower cement leakage rate. Additional high-quality randomized controlled trials designed to support these findings are warranted.

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.

Therapeutic Efficacy of Transpedicular Impaction Bone Grafting with Long Segmental Posterior Instrumentation in Stage III Kümmell Disease

STUDY DESIGN

A retrospective review of clinical and radiological parameters.

OBJECTIVE

To evaluate the therapeutic efficacy of transpedicular impaction bone grafting (TIBG) with long segmental posterior instrumentation for the treatment of stage III Kümmell disease.

SUMMARY OF BACKGROUND DATA

The optimal treatment for stage III Kümmell disease remains controversial and unclear. Theoretically, transpedicular bone grafting can reconstruct anterior column support and reduce the failure of internal fixation, which is an intuitive method for the treatment of Kümmell disease. However, the use of this technique has rarely been reported for the treatment of this disease. This study reported the clinical and radiological results of TIBG with long segmental posterior instrumentation for the treatment of stage III Kümmell disease.

METHODS

Between August 2011 and December 2017, we retrospectively analyzed 24 patients with stage III Kümmell disease who underwent TIBG with long segmental posterior instrumentation. Anterior vertebral heights, kyphotic Cobb angle, visual analog scale (VAS), Oswestry disability index (ODI), and American Spinal Injury Association (ASIA) impairment scale were used to evaluate the effects of surgery.

RESULTS

The mean time to follow-up was 38.1 ± 10.2 months. The average operative duration was 136 ± 16.5 minutes, and the average intraoperative blood loss was 293 ± 41.3 mL. The VAS, ODI, anterior vertebral heights, and kyphotic Cobb angles were improved significantly at 1 week after surgery compared the preoperative examinations, and were well maintained at the final follow-up evaluation. Fourteen patients (58%) had mild neurological impairments before surgery, with neurological function returning to normal at the final follow-up evaluation. There was no instance of instrumentation failure.

CONCLUSION

TIBG combined with long segmental posterior instrumentation is a safe and effective surgical option for stage III Kümmell disease.Level of Evidence: 4.

Long-Segmental Posterior Fusion Combined With Vertebroplasty and Wiring: Alternative Surgical Technique for Kummell's Disease With Neurologic Deficits-A Retrospective Case Series

Purpose

Various surgical methods have been reported for Kummell's disease with neurologic deficits. The aim of this study was to introduce long-segmental posterior fusion (LPF) combined with vertebroplasty (VP) and wiring as an alternative surgical technique.

Material and Methods

We retrospectively analyzed 10 patients undergoing posterior decompression and LPF combined with VP and wiring for Kummell's disease with neurologic deficits from January 2011 to December 2014. The radiologic outcomes included the local kyphotic angle (LKA) and segmental kyphotic angle (SKA). Clinical outcomes, including the visual analog scale (VAS), the Oswestry Disability Index (ODI) and the Frankel grade were assessed. Surgery-related complications were also evaluated.

Results

The mean age of the included patients was 77 ± 8 years with a mean follow-up period of 31.4 ± 4.9 months and a mean bone mineral density of -3.5 ± 0.7 (T-score). The mean operation time was 220 ± 32.3 minutes with a mean blood loss of 555 ± 125.7 mL. The preoperative LKA and SKA were significantly corrected postoperatively (37.9 ± 8.7° vs. 15.3 ± 5.3°, p = 0.005 for LKA; 21.3 ± 5.1° vs. 7.6 ± 2.8°, p = 0.005 for SKA) without a loss of correction at the last follow-up. The VAS and ODI were also significantly improved (7.7 ± 1.1 vs. 3.0 ± 1.6, p = 0.007 for VAS; 90.3 ± 8.9 vs. 49.6 ± 22.7, p = 0.007 for ODI). The Frankel grade of all patients was improved by at least 1 or 2 grades at the last follow-up. Surgery-related complications such as intraoperative cement leakage and implant loosening during the follow-up were not observed.

Conclusions

LPF combined with VP and wiring might be an effective surgical option for Kummell's disease with neurologic deficits, especially for the elderly patients with morbidities.

Level of Evidence

level IV.

CRISPR/Cas9-induced β-carotene hydroxylase mutation in Dunaliella salina CCAP19/18

Dunaliella salina (D. salina) has been exploited as a novel expression system for the field of genetic engineering. However, owing to the low or inconsistent expression of target proteins, it has been greatly restricted to practical production of recombinant proteins. Since the accurate gene editing function of clustered regularly interspaced short palindromic repeat (CRISPR)/Cas system, β-carotene hydroxylase gene was chosen as an example to explore D. salina application with the purpose of improving expression level of foreign genes. In this paper, based on pKSE401 backbone, three CRISPR/Cas9 binary vectors were constructed to targeting exon 1 and 3 of the β-carotene hydroxylase of D. salina CCAP19/18 (Dschyb). D. salina mutants were obtained by salt gradient transformation method, and the expression of Dschyb gene were identified through real-time fluorescent quantitative PCR. Moreover, carotenoids content was analyzed by high-performance liquid chromatography at different time points after high intensity treatment. Compared with wild type strains, the β-carotene levels of mutants showed a significant increase, nearly up to 1.4 μg/ml, and the levels of zeaxanthin decreased to various degrees in mutants. All the results provide a compelling evidence for targeted gene editing in D. salina. This study gave a first successful gene editing of D. salina which has a very important practical significance for increasing carotene yield and meeting realistic industry demand. Furthermore, it provides an approach to overcome the current obstacles of D. salina, and then gives a strong tool to facilitates the development and application of D. salina system.

Application of Titanium Alloy 3D-Printed Artificial Vertebral Body for Stage III Kümmell's Disease Complicated by Neurological Deficits

Purpose

The current study aimed to compare the clinical and radiographic results of the 3D-printed artificial vertebral body (3DP-AVB) and titanium mesh cage (TMC) for the treatment of Kümmell’s disease (KD) complicated by neurological deficits.

Patients and Methods

From January 2014 to July 2018, 28 consecutive patients diagnosed with KD and nerve injuries in our department were treated by posterior vertebral column resection and internal fixation. The patients were divided into two groups (3DP-AVB group and TMC group) based on the different anterior column reconstruction implants. Clinical and radiographic parameters were used to evaluate the outcomes.

Results

The two groups achieved excellent clinical and radiographic results 1 month after surgery with no significant difference (P>0.05), while 3DP-AVB group showed better outcomes compared with TMC group during the follow-up after 6 months (P<0.05). The risk of subsidence in 3DP-AVB group was lower than that in TMC group (41.6% vs 87.5%, P<0.05), and severe subsidence (≥5 mm) was correlated with the recurrence of back pain and bad daily life function. No significant difference was found in the improvement of neurological function between the two groups (P>0.05). The blood loss and operation time in 3DP-AVB group were significantly less than both in TMC group (P<0.05).

Conclusion

The lower incidence of cage subsidence, with a better long-term efficacy in maintaining the height of the fused segment, relieving back pain, and improving daily life function indicates that the 3DP-AVB may be a superior alternative for KD with neurological deficits.

Short-term outcomes of percutaneous pedicle screw fixation combined with vertebroplasty: A minimally invasive treatment for Kümmell's disease with intravertebral instability

OBJECTIVE

The aim of this study was to present early clinical and radiological outcomes of percutaneous pedicle screw fixation (PPSF) combined with vertebroplasty (VP) in the treatment of Kümmell's disease with intravertebral instability.

METHODS

In this study, 21 consecutive patients (4 male and 17 female; mean age = 75.6 years; age range=65-86 years) who suffered from stage II and III Kümmell's disease with intravertebral instability were prospectively recruited from 2012 to 2016 and treated with PPSF combined with VP. The Cobb angle (CA) or wedge angle (WA) in both flexion and extension positions was measured using lateral radiographs, computed tomography, or magnetic resonance imaging. In addition to these radiological parameters, clinical outcome measures, including the visual analog scale (VAS) and the Oswestry Disability Index (ODI) were collected preoperatively; 1 week and 1, 3, 6, and 12 months postoperatively; and then annually. Complications were also recorded.

RESULTS

The mean follow-up was 19.3 (range=12-36) months. The mean operating time was 135.4 (range, 110-175) min, and the mean estimated blood loss was 106.9 (range, 50-165) mL. The mean VAS score and ODI significantly decreased from 7.7±1.1 and 65.3%±7.7% preoperatively to 3.4±0.6 and 30.0%±7.6% postoperatively, respectively (p<0.05). At the final follow-up, the mean VAS score and ODI were 2.5±0.8 and 21.5%±8.8%, respectively (p>0.05). CA and WA significantly decreased from 26.9°±9.7° and 21.3°±6.0° preoperatively to 12.7°±7.2° to 8.6°±4.5° postoperatively, respectively (p<0.05). At the final follow-up, CA was 4.2°±2.0°, and WA was 4.7°±1.8° (p>0.05). No major complications were encountered during the follow-up period.

CONCLUSION

PPSF combined with VP seems to be an effective surgical option for the treatment of Kümmell's disease with intravertebral instability.

LEVEL OF EVIDENCE

Level IV, Therapeutic study.

Reliability and application of the new morphological classification system for chronic symptomatic osteoporotic thoracolumbar fracture

Background

We propose a new classification system for chronic symptomatic osteoporotic thoracolumbar fracture (CSOTF) based on fracture morphology. Research on CSOTF has increased in recent years; however, the lack of a standard classification system has resulted in inconvenient communication, research, and treatment. Previous CSOTF classification studies exhibit different symptoms, with none being widely accepted.

Methods

Imaging data of 368 patients with CSOTF treated at our hospital from January 2010 to June 2017 were systematically analyzed to develop a classification system. Imaging examinations included dynamic radiography, computed tomography scans, and magnetic resonance imaging. Ten investigators methodically studied the classification system grading in 40 cases on two occasions, examined 1 month apart. Kappa coefficients (κ) were calculated to determine intraobserver and interobserver reliability. Based on the radiographic characteristics, the patients were divided into 5 types, and different treatments were suggested for each type. Clinical outcome evaluation included using the visual analog score (VAS), the Oswestry disability index (ODI), and the American Spinal Injury Association (ASIA) impairment scale.

Results

The new classification system for CSOTF was divided into types I–V according to whether the CSOTF exhibited dynamic instability, spinal stenosis or kyphosis deformity. Intra- and interobserver reliability were excellent for all types (κ = 0.83 and 0.85, respectively). The VAS score and ODI of each type were significantly improved at the final follow-up compared with those before surgery. In all patients with neurological impairment, the ASIA grading after surgery was significantly improved compared with that before surgery (P < 0.001).

Conclusions

The new classification system for CSOTF demonstrated excellent reliability in this initial assessment. The treatment algorithm based on the classification can result in satisfactory improvement of clinical efficacy for the patients of CSOFT.

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.

An exploration of the rapid transformation method for Dunaliella salina system

As a new expression system, Dunaliella salina (D. salina) has bright prospects and applications in various fields. However, its application is currently restricted because of the low expression and instability of foreign gene in D. salina cells. During genetic operation, transformation is a crucial step for genes expression in D. salina system. Although several transformation methods are existing currently, many inherent deficiencies and limitations still can be found in actual practice. Thus, we attempted to set up a rapid transformation method using the change of salt concentrations for D. salina. Based on osmotic pressure difference, exogenous genes can be spontaneously transferred into D. salina cells. After that, transformed D. salina cells were subjected to histochemical and molecular analysis. The results showed that the reporter gene, beta-glucuronidase genes were successfully expressed in the positive transformants, and detected in all of transformed cells by PCR analysis. Moreover, different transformation parameters, containing the salt gradient, time, dye dosage and Triton X-100 concentration, were optimized to obtain an optimal transformation result. Taken together, we preliminarily established a rapid transformation method with the features of fast, simple, economic, and high-efficient. This method will provide a strong genetic manipulation tool for the future transformation of D. salina system.

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.

[Effectiveness of posterior short-segmental fixation with bone cement augmentation for stage Kümmell's disease with spinal canal stenosis]

OBJECTIVE

To investigate the effectiveness of posterior short-segmental fixation with bone cement augmentation in treatment of stage Ⅲ Kümmell's disease with spinal canal stenosis.

METHODS

Between June 2012 and January 2017, 36 patients with stage Ⅲ Kümmell's disease and spinal canal stenosis were treated by posterior short-segmental fixation and bone cement augmentation. There were 12 males and 24 females, aged 55-83 years (mean, 73.5 years). The disease duration ranged from 2 to 8 months, with an average of 4.6 months. Preoperative bone mineral density examination showed that all patients had different degrees of osteoporosis in the spines. The lesion segments included T 10 in 4 cases, T 11 in 7 cases, T 12 in 8 cases, L 1 in 9 cases, and L 2 in 8 cases. The preoperative neural function was classified as grade B in 4 cases, grade C in 12 cases, grade D in 13 cases, and grade E in 7 cases according to Frankle classification. The operation time, intraoperative blood loss, and the volume of injected bone cement, and hospital stay were recorded. The visual analogue scale (VAS) score, Oswestry Disability Index (ODI), kyphotic Cobb angle, and the height of anterior edge of injured vertebra were recorded before operation, at 1 week after operation, and at last follow-up; and the leakage of bone cement was observed.

RESULTS

All operations were completed successfully. The operation time was 90-145 minutes (mean, 110.6 minutes); the intraoperative blood loss was 198-302 mL (mean, 242.5 mL); the volume of injected bone cement was 8.3-10.5 mL (mean, 9.2 mL); the hospital stays were 7-12 days (mean, 8.3 days). All patients were followed up 12-26 months (mean, 24.5 months). At 1 week after operation, the neural function was classified as grade B in 2 cases, grade C in 8 cases, grade D in 12 cases, and grade E in 14 cases, which was significantly improved when compared with that before operation ( Z=2.000, P=0.047). The VAS score, ODI, the height of anterior edge of injured vertebra, and Cobb angle were significantly improved at 1 week and last follow-up when compared with preoperative values ( P<0.05); but there was no significant difference between 1 week and last follow-up ( P>0.05). Two cases had asymptomatic cement leakage to the intervertebral disc at 1 week after operation; and 1 case had adjacent vertebral fracture at 8 months after operation. No complication such as loosening or breaking of internal fixator occurred during the follow-up.

CONCLUSION

Posterior short-segmental fixation with bone cement augmentation is a safe and effective surgical scheme for stage Ⅲ Kümmell's disease combined with spinal canal stenosis, which can avoid the aggravation of nerve injury and complications related to staying in bed.

Thymosin participates in antimicrobial immunity in zebrafish

Thymosin hormones, which were shown to be involved in immune system development and differentiation in previous studies, have antimicrobial functions in different animals. Zebrafish are a useful model for immunology research. Although thymosin has been reported to be involved in the embryonic development of zebrafish, it is necessary to uncover the antimicrobial function of thymosin in zebrafish. In this study, we expressed thymosin β (Tβ) in zebrafish in vitro and studied its antimicrobial function. The Tβ protein consists of 45 amino acids and is conserved among its family members, especially the actin-binding motif (LKKTET). Tβ was expressed in all tested tissues and was highly expressed in the brain, liver and hindgut. After Aeromonas hydrophila challenge, the Tβ transcript level increased in the skin, liver, kidney, spleen, thymus, foregut, gills and midgut. Purified recombinant thymosin β (rTβ) protein was used to study the antimicrobial mechanism. rTβ could inhibit the growth of Staphylococcus aureus, Aeromonas hydrophila, Vibrio anguillarum, Pseudomonas aeruginosa and Klebsiella pneumoniae. rTβ also binds to and agglutinates certain bacteria. Further study showed that rTβ could combine with the polysaccharides from gram-negative and gram-positive bacterial walls. All results suggested that the Tβ of zebrafish plays a significant role in innate antibacterial immune responses.

Titanium mesh bone grafting combined with pedicle screw internal fixation for treatment of Ku[Combining Diaeresis]mmell disease with cord compression: A case report and literature review

RATIONALE

In 1891, Dr. Hermann Kümmell, a German surgeon, described a clinical entity characterized by the development of progressive painful kyphosis following an asymptomatic period of months or years after a minor spinal trauma, leading to a gradual collapse of the vertebra and dynamic instability, ultimately progressing to kyphosis with prolonged back pain and/or paraparesis. To date, the main pathologic eliciting event remains unclear, and no standard treatment or single effective treatment are available for Kümmell disease.

PATIENT CONCERNS

A 74-year-old woman presented with severe back pain and numbness of both legs for approximately 2 months.

DIAGNOSES

According to the clinical symptoms and imaging examinations, the patient was diagnosed with stage III Kümmell disease.

INTERVENTIONS

The patient underwent titanium mesh bone grafting combined with pedicle screw internal fixation.

OUTCOMES

Postoperative kyphosis was corrected, and the vertebra was reconstructed.

LESSONS

Kümmell disease is not a rare complication of osteoporotic vertebral compression fractures, and treatment of each patient must be individualized. The application of titanium mesh bone grafting combined with pedicle screw internal fixation is an effective treatment option for stage III Kümmell disease.

Percutaneous kyphoplasty treatment evaluation for patients with Kümmell disease based on a two-year follow-up

Percutaneous kyphoplasty (PKP) has been used in Kümmell disease treatment for years. The objective of the current study was to evaluate the efficacy and safety of PKP in the treatment of patients with Kümmell disease and to explore the association between cement injection volume and pain relief. A total of 50 patients were enrolled in the present study and follow-up was 2 years. Efficacy was evaluated using the Visual Analog Scale (VAS), the Oswestry Disability Index (ODI) and the kyphotic angle (Cobb's angle). VAS and ODI were determined at the initial evaluation (prior to surgery), at 3 days, 3 months, and 1 and 2 years post surgery. Cobb's angle was measured prior to and 3 months, 1 year and 2 years following surgery. PKP safety was assessed by evaluating complications, including cement leakage and spinal cord compression. In the follow-ups, VAS significantly decreased from 7.00±0.78 pre-PKP to 3.14±0.67 at 2 years post-PKP (P<0.05). ODI significantly decreased from 73.88±8.60 prior to surgery to 22.84±8.85 at 1 year following surgery (P<0.05) and did not significantly change at the following 2-year measurement (26.44±8.63). The Cobb's angle, measured at 17.73±2.43° preoperatively, significantly decreased to 8.32±2.21° at 3 months following surgery (P<0.05). On subsequent follow-ups at 1 and 2 years, the Cobb's angle increased to 9.55±2.82 and 10.27±3.22°, respectively. A total of 8 patients exhibited signs of cement leakage during the PKP procedure. No patients experienced severe neurological deficits or complications. Spearman analysis demonstrated a positive correlation between cement injection volume and pain relief. The current study indicated that PKP was a safe and effective treatment for patients with Kümmell disease and that there was a positive correlation between cement injection volume and pain relief. The current study may be used a reference in cement dosing for the treatment of PKP.

Anterior reconstruction versus posterior osteotomy in treating Kümmell's disease with neurological deficits: A systematic review

OBJECTIVE

This study aimed to conduct a systematic review of literature comparing the clinical effectiveness and safety between anterior reconstruction (AR) and posterior osteotomy (PO) in the treatment of Kümmell's disease with neurological deficits.

METHODS

We systematically reviewed the literature in PubMed, EMBASE, Cochrane Database of Systematic Reviews, and the Web of Science for "spin*," "surg*," "Kümmell's disease," "Kummell's disease," "Kummell disease," "vertebral osteonecrosis," "vertebral pseudarthrosis," "intravertebral vacuum cleft," "delayed vertebral collapse," and "compression fracture nonunion". Quality was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation method.

RESULTS

A total of 10 publications involving 268 Kümmell's disease patients with neurological deficits were included in this review, with 7 studies of low- or very low-quality. There were 37.7% and 62.3% of patients receiving AR and PO, respectively. For clinical outcomes, AR group showed no significant differences in pain, neurological dysfunction, and imaging outcome improvements compared with patients who underwent PO. However, the incidence of implant-related complications including loose screw, screw fracture, screw disconnection, and plate dislodgment, was higher in AR group compared with PO group (21.6% vs. 14.3%). As another major complication, AR group more often required a second surgery.

CONCLUSION

This systematic review demonstrated that both AR and PO could improve pain, neurological dysfunction and imaging outcomes. However, serious comorbidities, multilevel corpectomies and/or severe osteoporosis highly required PO. Design discrepancies were found in the current studies, further higher-quality studies are warranted.

LEVEL OF EVIDENCE

Level III, therapeutic study.

What is the Current Evidence on Vertebral Body Osteonecrosis?: A Systematic Review of the Literature

Osteonecrosis (ON) is a clinical entity characterized by a pattern of cell death and complex process of bone resorption and formation. Studies related to ON have largely focused on certain anatomical sites; however, the evidence on vertebral body ON (VBON) is largely inconsistent and fragmented. The aim of this study was to clarify the pathophysiology, risk factors, imaging findings, and available treatment modalities for VBON. A systematic review of the relevant articles published in English was performed using PubMed, Embase, Medline, Google Scholar, Cochrane Central Register of Controlled Trials (CENTRAL), and CINAHL databases. A total of 81 articles were included in this study. Three main topics about VBON were identified: (1) pathophysiology and risk factors, (2) diagnosis, and (3) treatment. Forty-five studies were based on the pathophysiology, 52 on diagnosis, and 38 on the treatment options for VBON. The literature on VBON was limited and mainly focused on post-traumatic cases with a considerable overlap with nonunion and pseudoarthrosis.

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

BACKGROUND The purpose of this study was to compare the efficacy of percutaneous kyphoplasty (PKP) and bone cement-augmented short segmental fixation (BCA+SSF) for treating Kümmell disease. MATERIAL AND METHODS Between June 2013 and December 2015, 60 patients were treated with PKP or BCA+SSF. All patients were followed up for 12-36 months. We retrospectively reviewed outcomes, including Oswestry Disability Index (ODI), visual analogue scale (VAS), and kyphotic Cobb angle. RESULTS VAS, ODI, and Cobb angle, measured postoperatively and at the final follow-up, were lower than those measured preoperatively in both groups (P<0.05). VAS, ODI, and Cobb angle measured postoperatively demonstrated no significant differences when compared with those measured at the final follow-up in the PKP group (P>0.05). In the BCA+SSF group, VAS and ODI at the final follow-up were lower than those measured postoperatively (P<0.05), but no significant difference was found in the Cobb angle (P>0.05). The PKP group had better VAS and ODI than the BCA+SSF group, postoperatively (P<0.05). No significant difference was found in VAS and ODI at the final follow-up (P>0.05) or the Cobb angle measured postoperatively and at the final follow-up (P>0.05) between the 2 groups. Operative time, blood loss, and hospital stay in the PKP group were lower than those in the BCA+SSF group (P<0.05). No significant difference was found in complications (P>0.05). CONCLUSIONS PKP patients had better early clinical outcomes, shorter operation times and hospital admission times, and decreased blood loss, but had similar complications, radiographic results, and long-term clinical outcomes compared with BCA+SSF patients.

Bone Cement-Augmented Short-Segment Pedicle Screw Fixation for Kümmell Disease with Spinal Canal Stenosis

Background

This study aimed to explore the feasibility and efficacy of bone cement-augmented short-segmental pedicle screw fixation in treating Kümmell disease.

Material/Methods

From June 2012 to June 2015, 18 patients with Kümmell disease with spinal canal stenosis were enrolled in this study. Each patient was treated with bone cement-augmented short-segment fixation and posterolateral bone grafting, and posterior decompression was performed when needed. All patients were followed up for 12–36 months. We retrospectively reviewed outcomes, including the Oswestry disability index (ODI), visual analog scale (VAS) score, anterior and posterior heights of fractured vertebrae, kyphotic Cobb angle, and neurological function by Frankel classification.

Results

The VAS grades, ODI scores, anterior heights of affected vertebrae, and kyphotic Cobb angles showed statistically significant differences between pre- and postoperative and between preoperative and final follow-up values (P<0.05), whereas the differences between postoperative and final follow-up values were not statistically significant (P>0.05). The differences between posterior vertebral heights at each time point were not statistically significant (P>0.05). Improved neurological function was observed in 12 cases at final follow-up. Three cases had complications, including asymptomatic cement leakage in 2 patients and delayed wound infection in 1 patient.

Conclusions

Bone cement-augmented short-segment pedicle screw fixation is safe and effective for treating Kümmell disease, and can achieve satisfactory correction of kyphosis and vertebral height, with pain relief and improvement in neurological function, with few complications.

Posttraumatic Delayed Vertebral Collapse : Kummell's Disease

Posttraumatic delayed vertebral collapse, known as Kummell’s disease, is increasing in number of patients. This disease is already progressive kyphosis due to vertebral collapse at the time of diagnosis and it causes intractable pain or neurologic deficit due to intravertebral instability. Treatment is very difficult after progression of the disease, and the range of treatment, in hospital day, and cost of treatment are both increased. Clinical features, pathogenesis and radiologic findings of these disease groups were reviewed to determine risk factors for delayed vertebral collapse. The purpose of this article is to suggest appropriate treatment before vertebral collapse for patients with osteoporotic vertebral compression fracture who have risk factors for posttraumatic delayed vertebral collapse.

Kümmell's Disease Treated with Percutaneous Vertebroplasty: Minimum 1 Year Follow-Up

Objective

To evaluate the radiographic and clinical outcomes of percutaneous vertebroplasty (PVP) in patients with Kümmell's disease.

Methods

A retrospective review was conducted for 19 vertebrae in 18 patients, between January 2012 and June 2016. A visual analogue scale (VAS) score was used to determine each patient's subjective level of pain (0=no pain to 10=severe pain) preoperative, immediately postoperative and at the last follow-up (at least 12 months after PVP).Radiographic parameters such as regional and global kyphotic angle, lumbar lordosis (LL), thoracolumbar junction (TLJ) angle, vertebral height, cement leakage, refracture, and adjacent level fracture were evaluated by the clinician preoperative, immediate postoperative and at the last follow-up.

Results

The mean VAS score significantly decreased after PVP and the decrease was maintained through to the final follow-up (p<0.05). However, the regional and global kyphotic angle, LL, and TLJ angle were not improved. Cement leakage was observed in 5 cases (26.3%): however, there were no cases of cement leakage into the spinal canal. No neurological deterioration was observed, even among patients with cement leakage. Adjacent level fractures were detected in 3 cases (15.8%).

Conclusion

PVP can be considered as an effective treatment option for pain relief and maintenance of sagittal balance in patients with Kümmell's disease.

[Effectiveness comparison between two operations in treatment of unstable type Kümmell's disease]

Objective

To compare the effectiveness between short segmental fixation combined with vertebroplasty (SSF+VP) and short segmental pedicle screw fixation combined with bone graft (SSF+BG) in the treatment of unstable type Kümmell's disease so as to provide a reference for the selection of the surgical method.

Methods

Between March 2013 and February 2015, 48 patients with unstable type Kümmell's disease who were in accordance with the inclusive criteria were included in the study. SSF+VP were used in 25 cases (SSF+VP group) and SSF+BG in 23 cases (SSF+BG group). There was no significant difference in gender, age, disease duration, bone mineral density, fracture segment, and preoperative visual analogue scale (VAS), Oswestry disability index (ODI), and kyphotic Cobb angle between 2 groups ( P>0.05). The operation time and complications related to operation were recorded; the effectiveness was evaluated by VAS, ODI, and kyphotic Cobb angle.

Results

The operation time was (107.7±18.8) minutes in SSF+VP group and was (113.7±22.4) minutes in SSF+BG group, showing no significant difference between 2 groups ( t=-1.045, P=0.302). Bone cement leakage occurred in 6 cases of SSF+VP group, and incision delayed healing occurred in 1 case of SSF+BG group. All patients achieved bone graft fusion on X-ray films. The bone graft fusion time was (15.1±1.3) weeks in SSF+VP group and (15.7±1.8) weeks in SSF+BG group, showing no significant difference between 2 groups ( t=-1.361, P=0.180). The VAS, ODI, and kyphotic Cobb angle at immediate after operation and at last follow-up were significantly lower than preoperative ones ( P<0.05). The VAS, ODI, and kyphotic Cobb angle had no significant difference between at immediate and at last follow-up in SSF+VP group ( P>0.05). In SSF+BG group, VAS at last follow-up was significantly lower than that at immediate after operation ( P<0.05), but no significant difference was found in kyphotic Cobb angle and ODI ( P>0.05). SSF+VP group was significantly better than SSF+BG group in VAS at immediate after operation ( P<0.05), but SSF+BG group was significantly better than SSF+VP group at last follow-up ( P<0.05). There was no significant difference in kyphotic Cobb angle and ODI between 2 groups at immediate after operation and at last follow-up ( P>0.05).

Conclusion

SSF+BG can achieve satisfactory effectiveness in the treatment of unstable type Kümmell's disease, and it has the advantages of good bony healing, obvious improvement of pain, and low complication incidence when compared with SSF+VP.

Modified posterior vertebral column resection for Kümmell disease: Case report

RATIONALE

Kümmell's disease is defined as delayed traumatic vertebral collapse disease in which patients develop a kyphosis after asymptomatic minor spinal trauma. Both anterior approach and posterior approach have been reported, however, there is no standard treatment for Kümmell's disease.

PATIENT CONCERNS

We described a successful modified posterior vertebral column resection in a patient with Kümmell's disease. A 65-year-old woman reported persistent back pain for almost three months.

DIAGNOSES

Kümmell's disease was diagnosed based on computer tomography (CT) and magnetic resonance imaging (MRI).

INTERVENTIONS

Modified posterior vertebral column resection combined with short-segment fixation was designed to treat this disease.

OUTCOMES

The procedure was successful without any complications. Patient reported that symptoms were obviously improved in one week after operation.

LESSONS

Modified posterior vertebral column resection combined with short-segment fixation is an effective treatment option for Kümmell's disease.

An Effective Treatment Option for Kümmell Disease With Neurological Deficits: Modified Transpedicular Subtraction and Disc Osteotomy Combined With Long-Segment Fixation

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To illustrate the technique of modified transpedicular subtraction and disc osteotomy combined with long-segment fixation for the treatment of Kümmell disease with neurologic deficits and to evaluate clinical and radiographic results of patients treated with the technique.

SUMMARY OF BACKGROUND DATA

Kümmell disease is a clinical condition in which patients develop a kyphosis in the lower thoracolumbar spinal region months to years after sustaining an otherwise asymptomatic minor spinal. Currently, for patients with neurological deficits, anterior decompression with bone grafting fusion, posterior decompression with pedicle subtraction osteotomy, or a combined anterior and posterior approach operation were used; however, there is no standard treatment and no single effective treatment for Kümmell disease.

METHODS

Between May 2009 and May 2012, we reviewed 12 patients experiencing Kümmell disease with neurological deficits who underwent modified transpedicular subtraction and disc osteotomy combined with long-segment fixation. Preoperative and postoperative Cobb angle, visual analog scale, Asia Spinal Injury Association, and sagittal balance were documented. The patients were followed up for 33 months on average.

RESULTS

The Cobb angles decreased from 43.33 ± 7.44° to 1.92 ± 2.74° (P < 0.01), the mean visual analog scale reduced from 7.17 ± 1.27° to 1.17 ± 1.03° (P < 0.01), and the sagittal vertical angle improved from 14.82 ± 3.56 cm to 5.15 ± 2.10 cm (P < 0.01). Kyphotic deformity was successfully corrected and solid fusion was achieved in all cases. Neurologic function of nine cases was improved to various degrees.

CONCLUSION

Modified transpedicular subtraction and disc osteotomy combined with long-segment fixation is an effective treatment option for Kümmell disease with neurological deficits.

LEVEL OF EVIDENCE

4.

Comparative Study of Modified Posterior Operation to Treat Kümmell's Disease

The present study aimed at examining the curative effect of modified posterior operation on treatment of Kümmell's disease. About 30 patients of Kümmell's disease with complete image and clinical data treated during June 2004 to July 2013 were conducted with anterior and posterior approaches, respectively. Kyphotic Cobb angle, fractured vertebra wedge angle, and the anterior and posterior heights of fractured vertebra were all measured through x-ray before and after operation, and the pain visual analog scale (VAS) was determined for evaluating the effect of operations. The injury and restoration of neurological function were assessed using Frankel classification. Patients in group A were treated with anterior operation, whereas group B was posterior operation. Postoperatively, VAS score, kyphotic Cobb angle, anterior vertebra height, and pathologic vertebra wedge angle were all significantly improved in patients with Kümmell's disease receiving modified posterior operation (group B). Similar results were also observed in patients with anterior operation. The improvement of VAS and correction rate of kyphotic Cobb angle indicated equivalent effects of posterior and anterior operations. Meanwhile, alleviated neurological function damage was observed in 2 groups. Relevant factor analysis illustrated that there was no significant correlation of the severity and improvement rate of pain symptoms with age, medical history, anterior and posterior vertebra heights, kyphotic Cobb angle, and pathological vertebra wedge angle. Compared with traditional anterior approach, modified posterior operation, adopting transpedicular vertebral body grafting combined with vertebral pedicle screw fixation, could produce equivalent effects on kyphosis correction, pain relief, and improvement of neurological function in patients with Kümmell's disease.

Comparison of percutaneous vertebroplasty and percutaneous kyphoplasty for the management of Kümmell's disease: A retrospective study

BACKGROUND

Post traumatic osteonecrosis of a vertebral body occurring in a delayed fashion was first described by the German doctor Kümmell in 1895. Several studies have reported percutaneous vertebroplasty (PVP), or percutaneous kyphoplasty (PKP) for Kümmell's disease achieves good outcomes. However, it is unknown whether a technique is superior for the treatment of this disease. The objective of the study is to compare the efficacy of PVP and PKP for the treatment of Kümmell's disease.

MATERIALS AND METHODS

A retrospective review was conducted for 73 patients with Kümmell's disease. PVP was performed in 38 patients and PKP in 35 patients. Visual analogue score (VAS) was used to evaluate pain. The anterior vertebral height was measured. The operative time, the incidence of cement leakage and the costs were recorded.

RESULTS

In both PVP group and PKP group, the VAS and anterior vertebral height significantly improved at 1-day postoperatively (P < 0.05), and the improvement sustained at the final followup (P > 0.05). Between the PVP and PKP groups, there were no significant differences in VAS and the anterior vertebral height at 1-day postoperatively and at the final followup (P > 0.05). The operating time and expense in the PKP group were higher than the PVP group (P < 0.001). Cement leakages in the PKP group were fewer than PVP group (P < 0.05).

CONCLUSIONS

PVP is a faster, less expensive option that still provides a comparable pain relief and restoration of vertebral height to PKP for the treatment of Kümmell's disease. PKP has a significant advantage over PVP in term of the fewer cement leakages.