Surgical and Clinical Results of Minimally Invasive Spinal Fusion Surgery in an Unselected Patient Cohort of a Spinal Care Unit.

OBJECTIVES: To review the surgical results and to identify possible parameters influencing the clinical outcomes in an unselected patient collective undergoing minimally invasive lumbar interbody fusion in a spinal care unit. METHODS: A total of 229 adult patients who underwent minimally invasive lumbar spinal fusion between 2008 and 2016 were included in this retrospective analysis. Lumbar fusion was performed using transforaminal interbody fusion (TLIF) devices and posterolateral fusion. To eliminate confounding parameters, in all patients interbody fusion was indicated by lumbar degenerative pathologies, and surgery was performed using the same fusion device. Treatment efficacy was evaluated using scores describing pain (visual analogue scale [VAS]) and health impairment (EQ-5D, Oswestry Disability Index [ODI]). The influence of patient age, obesity, active smoking status, and co-morbidities on clinical outcome and perioperative complications was analyzed. RESULTS: The patient population reviewed had improved VAS (P(leg pain) ≤ 0.0001, P(back pain) ≤ 0.0001), ODI (P ≤ 0.0001), EQ-VAS (P ≤ 0.0001), and EQ-5D subscales "mobility", "self-care", "pain", and "anxiety" (P(mobility) ≤ 0.0001, P(self-care) = 0.41, P(pain) ≤ 0.0001, P(anxiety) = 0.011) postoperatively. Neither advanced patient age, nor increased body mass index (BMI), hypertension, or active smoking status had a significantly limiting influence on the success of minimally invasive spinal surgeries (MIS). Duration of surgery strongly correlated with the number of spinal levels treated and with intraoperative blood loss (r = 0.774, P ≤ 0.0001, n = 208). Weak positive correlations were found between patient age and duration of surgery (r = 0.184, P = 0.005, n = 229), intraoperative blood loss (r = 0.165, P = 0.012, n = 229), and duration of hospitalization (r = 0.270, P ≤ 0.0001, n = 228), respectively. When compared to non-smokers, smokers were younger (P ≤ 0.0001), and had a significantly lower BMI (P = 0.001), shorter durations of surgery (P ≤ 0.0001), decreased intraoperative blood loss (P = 0.022), and shorter hospital stays (P = 0.006), respectively. Complications occurred in 17 patients (7%) and were not affected by patient age, BMI, hypertension, or active smoking status. CONCLUSION: Minimally invasive spinal surgery is a safe and effective treatment option and may be superior to open surgery in subpopulations with significant co-morbidities and risk factors, such as elderly and obese patients as well as patients with an active smoking status.

Randomized, prospective, monocentric study to compare the outcome of continuous passive motion and controlled active motion after total knee arthroplasty.

BACKGROUND: The number of patients requiring a total knee arthroplasty (TKA) is increasing and postoperative care is an important factor for the recovery of knee function. It is discussed controversially, if the benefits of controlled active motion (CAM) therapies are comparable to continuous passive motion (CPM) therapies. OBJECTIVE: Comparison of postoperative outcomes using a device in CAM and CPM settings, in addition to standard physiotherapeutical exercises immediately after TKA. METHODS: TKA patients were randomized to either CAM or CPM therapy performed with an identical device (ARTROMOT® ACTIVE-K, Ormed GmbH). All patients received an additional physiotherapeutic program. Pain, knee associated problems (KOOS), active range of motion (ROM), and adverse events were documented before surgery, during the stationary stay and after an outpatient period. RESULTS: We included 50 patients (70 ± 8 years). During the postoperative period, KOOS scales improved significantly in both groups, but the CAM group showed a significantly better improvement of pain and quality of life scale. Furthermore, postoperative course of pain intensity and knee flexion was significantly better in the CAM group. CONCLUSIONS: CAM and CPM lead to significant improvements after TKA, but CAM shows better results in terms of flexion, pain and quality of life.

Influence of radiofrequency kyphoplasty on pulmonary function.

BACKGROUND: Vertebral compression fractures (VCF) change the natural spinal alignment and inevitably lead to a decreased quality of life. OBJECTIVE: The aim of the study was to evaluate changes in pulmonary function after VCF were treated by radiofrequency kyphoplasty (RF-TVA). METHODS: Twenty-five patients were treated with RF-TVA and analyzed in 3 subgroups taking into account the spinal location of the VCF. Pain as measured by visual analogue scale (VAS), Oswestry-Disability-Index (ODI), vertebral height, forced expiratory volume in 1 second (FEV1), and peak expiratory flow (PEF) were assessed before, directly after and 30 days after RF-TVA. RESULTS: The mean vertebral height was improved in all subgroups, with a minor reduction from one to 30 days postoperatively. The mean VAS and ODI significantly decreased in the main and upper diaphragm groups from baseline to the follow-up after 30 days. Patients treated below the main diaphragm region showed a significant improvement of ODI and a clear trend to significant improvements of VAS. PEF and FEV1 were significantly improved in the main diaphragm group. FEV1 also increased significantly in the upper diaphragm group with a clear trend to significance in the lower diaphragm group. CONCLUSIONS: Results indicate that RF-TVA may improve pulmonary function especially in cases where fractures are located in the main spinal region of the diaphragm.

Two-year clinical results of patients with sacroiliac joint syndrome treated by arthrodesis using a triangular implant system.

BACKGROUND: Sacroiliac joint (SIJ) syndrome can cause various symptoms and may also be one reason for persistent low back pain, especially in patients with prior spinal fusions. If conservative treatments fail to improve symptoms, arthrodesis surgery can be considered. Minimally invasive approaches have emerged recently providing a good alternative to conventional methods. A novel triangular implant system (iFuse) can achieve an arthrodesis of the SIJ without the use of additional screws or bone material. OBJECTIVE: Aim of the present study was an evaluation of short-term safety and efficacy of the implant system. METHODS: Twenty-four patients were included in the study and treated with the iFuse system. In addition to demographic data, pain intensity (visual analogue scale) and functional impairment (Oswestry-disability index) were assessed prior to surgery and 1 month, 3 months, 6 months, 12 months and 24 months thereafter. During surgery and the follow up period all adverse events were documented and the correct implant position was controlled via plain radiographs. RESULTS: VAS scores and ODI improved significantly directly after surgery from 84.3 ± 9.2 mm to 40.7 ± 9.2 mm and from 76.8 ± 9.2% to 40.7 ± 9.2 % (p < 0.001). The ODI improved further to 31 ± 5.4% after 24 months whereas the VAS improved until the 3 months examination and ten stayed constant between 27.7 mm and 26.5 mm to 27 ± 6.6 mm at 24 months. No adverse events, intraoperative complications, implant malpositioning or loosening could be recorded at any time. CONCLUSIONS: The iFuse system is an effective and safe treatment for minimally invasive surgical arthrodesis of the SIJ. Pain and functional impairment can be significantly improved. However, in addition to this case series, further controlled studies are necessary, particularly in terms of a previous spinal fusion history.

Interaction of radiation therapy and radiofrequency kyphoplasty in the treatment of myeloma patients.

BACKGROUND: 30% of myeloma patients suffer from vertebral compression fractures (VCF). Consequently, augmentation often becomes inevitable to prevent further problems. This study evaluated the interaction of radiation therapy (RT) and radiofrequency kyphoplasty (RFK) in the treatment of myeloma associated VCF. METHODS: Eighty-six myeloma patients with VCF were treated with RFK followed by radiation therapy (RFK group) or vice versa (RT group). Visual analgoue scale (VAS), Oswestry-Disability-Index (ODI), vertebral height and kyphosis angle were assessed preoperatively, 3-4 days, 3 and 6 months postoperatively. Adverse events like cement leakage or additional fractures were documented. RESULTS: Both groups achieved comparable outcomes, but the course of VAS and kyphosis angle differed. Early postoperative kyphosis angles improved significantly in the RFK group, but significantly worsened afterwards. The RT group showed a trend towards significantly improvement postoperatively and minor worsening afterwards. VAS remained constant in the RT group and worsened in the RFK group after 6 months. More cement leakages and additional fractures were noted in the RT group. CONCLUSIONS: RFK is an effective method for treating VCF in myeloma patients independent of treatment order with regard to radiation therapy. However, RT should be conducted after RFK to minimize risks of cement extrusion and additional fractures.

Elastoplasty: A Silicon Polymer as a New Filling Material for Kyphoplasty in Comparison to PMMA.

BACKGROUND: Painful vertebral compression fractures (VCF) caused by osteoporosis are a common health problem in the elderly population. If conservative treatments are unsuccessful, surgical treatments like vertebroplasty or kyphoplasty are recommended. But the use of Polymethylmethacrylat (PMMA) bone cement for augmentation surgery is associated with risks. OBJECTIVES: Evaluation of the effectiveness and safety of a newly developed silicon polymer (VK100) that can be used instead of PMMA bone cement for kyphoplasty treatments. STUDY DESIGN: A retrospective study of 30 patients comparing the outcomes of kyphoplasty treatments conducted with PMMA and VK100. SETTING: Clinic for Orthopedics and Trauma Surgery Bonn, Germany. METHODS: Thirty patients with one to 3 VCF were treated either with balloon kyphoplasty using VK100 or balloon kyphoplasty using PMMA bone cement. Data from both groups was compared by a matched pair analysis. The medial vertebral height was measured at each examination radiologically. The patients stated their pain intensity using the Visual Analogue Scale (VAS) and the patient's functional impairment was evaluated with the Oswestry-Disability-Index (ODI).All data were assessed before surgery, and 3 days, 3 months, 6 months, and 12 months after surgery. Intraoperative and postoperative adverse events were documented. RESULTS: The patients' functional impairment and pain improved significantly after surgery. The course of ODI and VAS was comparable in both treatment groups, but the improvement in the VK group was significantly ongoing until the 12 month follow-up. Vertebral height improvement was significant in both groups, but the PMMA group achieved a better absolute restoration. The vertebral height stayed constant during the follow-up in the VK group and worsened significantly in the PMMA group. There was no significant difference between groups concerning the occurrence of additional fractures; and no other types of complications or surgery-related adverse events were observed in either the PMMA group or in the VK group. LIMITATIONS: The study is only a matched pair analysis of 15 patients for each procedure and the amount of injected filling material was not recorded. CONCLUSION(S): The study results demonstrate that the clinical outcome of VAS and ODI of using the silicon polymer VK100 is comparable or slightly better than using PMMA. VK 100 shows a trend to minor additional fractures during the follow-up. However, height restoration is not satisfactory in comparison to PMMA, although vertebral height stayed more or less constant in the VK group. To address the augmentation success further, it would be necessary to study a larger patient group over a longer study period and to assess additional parameters such as bone density and injected amount of filling material.

Mid-term outcomes after radiofrequency-targeted vertebral augmentation in the treatment of myeloma associated vertebral fractures.

BACKGROUND: Myeloma patients often suffer from painful vertebral fractures (VCF) which impair their quality of life. Common methods for augmentation of the vertebrae are vertebroplasty, kyphoplasty and radiofrequency-targeted vertebral augmentation (RF-TVA). OBJECTIVE: This study evaluates the long-term effectiveness and safety of RF-TVA in the treatment of myeloma associated VCF. METHODS: Eighty-seven myeloma patients (mean age: 64.7 ± 9.5 years) with VCF were treated with RF-TVA. Patient data were assessed preoperatively and in five postoperative examinations up to 12 months. Pain was measured with the visual analogue scale (VAS) and the impairment was evaluated with the Oswestry-Disability-Index (ODI) at each examination. In addition, the mid vertebral height, kyphosis angle, and additional fractures were evaluated by x-rays. Furthermore, cement leakage was documented. RESULTS: The VAS values were significantly improved in comparison to the preoperative values (p≤ 0.001), but slightly fluctuating during the follow-up period. The ODI was also significantly improved (p≤ 0.001), but it showed a worsening from the 12 months evaluation to the 24 months evaluation. The kyphosis angle and the vertebral height were significantly improved after surgery (p = 0.03, p ≤ 0.001), but worsened steadily to the last follow up examination. Cement leakage was asymptomatic and occurred in 18% of the patients. In 10% of the patients additional fractures were detected in the 24 months evaluation. CONCLUSIONS: The results of our study show that RF-TVA is a safe treatment for myeloma associated vertebral compression fractures, which achieves an acceptable improvement of patient's pain and quality of life.

Temperature distribution during radiofrequency ablation of spinal metastases in a human cadaver model: Comparison of three electrodes.

BACKGROUND: Radiofrequency ablation (RFA) temperatures reaching 45°C in adjacent tissues are cytotoxic to the spinal cord, nerves and surrounding tissues. OBJECTIVE: This study compares different RFA electrodes with regard to the temperature distribution during ablation of spinal metastases. METHODS: In vitro experimental study in isolated lumbar vertebrae of a human cadaveric spine. The temperature distribution of RFA electrodes was measured during ablation in human cadaveric lumbar vertebrae containing a simulated vertebral body lesion. The analysis compared a novel bipolar RFA electrode with two conventional monopolar RFA electrodes. A vertebral metastasis model was prepared in eight lumbar vertebrae for each electrode. Differences between the electrodes were evaluated with a one-way ANOVA. RESULTS: The lowest temperature at the thermocouples adjacent to the simulated lesion was achieved when using the bipolar RFA electrode (46.4 ± 3.3°C), but temperature difference to the monopolar RFA electrodes was not significant. In the neural foramen and epidural space of lumbar vertebrae the maximal temperature measured when using the bipolar RFA electrode was 37.0 ± 0°C and 37.3 ± 0.7°C, which was significantly lower than during ablation via either of the monopolar RFA electrodes (p ≤ 0.001). CONCLUSIONS: Temperatures in areas of adjacent tissue during RFA using a specific for spinal ablation designed electrode with integrated thermocouples were significantly lower compared to other electrodes, potentially reducing temperature related risks during ablation.

Influence of smoking on spinal fusion after spondylodesis surgery: A comparative clinical study.

BACKGROUND: Smoking is a risk factor in the process of bone healing after lumbar spondylodesis, often associated with complications that occur intraoperatively or during follow-up periods. OBJECTIVE: To assess if smokers yield worse results concerning lumbar interbody fusion than non-smokers in a clinical comparative setting. METHODS: Spondylodesis outcomes in 50 patients, 34 non-smokers (mean 58 years; (range 29-81) and 16 smokers (mean 47 years; range 29-75) were compared preoperatively and one year after spondylodesis surgery using Oswestry-Disability-Index (ODI), visual analogue scale (VAS) and radiological outcome analysis of fusion-success. RESULTS: Smokers showed a comparable ODI-improvement (p = 0.9343) and pain reduction to non-smokers (p = 0.5451). The intake of opioids was only reduced in non-smokers one year after surgery. Fusion success was significantly better in non-smokers (p = 0.01). CONCLUSIONS: The results indicate that smoking adversely effects spinal fusion. Particularly re-operations caused by pseudarthrosis occur at a higher rate in smokers than in non-smokers.

Clinical efficacy and safety of a new flexible interbody spacer system.

BACKGROUND: Patients with lumbar degenerative disk disease (DDD) often require an interbody fusion. Several spacer systems have been developed to achieve an adequate fusion. The newly developed flexible interbody spacer system (Luna®, Benvenue Medical Inc.) expands to the disk space and is adjustable to the patient's anatomy. OBJECTIVE: Prospective monocentric evaluation of interbody fusions performed with the new system in patients with DDD to assess the device's efficacy and safety. METHODS: The study includes patients with DDD of one or two contiguous lumbar levels. All patients were treated with the new flexible cage system. To evaluate the clinical outcome, examinations were conducted preoperatively, 6 weeks, 6 months and 12 months postoperatively. At each study visit possible implant loosening was assessed by plain radiography and any adverse events were documented. Furthermore, back pain was evaluated using the visual analogue scale (VAS), functional impairment using the Oswestry-Disability-Index (ODI) and quality of life using the SF36. RESULTS: A total of 30 patients (age: 52.8 ± 11 years, gender: 53% male) were included. None of the patients showed signs of implant loosening and the total number of adverse events was low (3%). The VAS improved significantly from 81.2 ± 9.5 mm at baseline to 28 ± 26.2 mm after 12-months (p ≤ 0.0001). The ODI also improved significantly from 57.9 ± 9.6% at baseline to 20 ± 15.6% after 12-months (p ≤ 0.0001). The physical component score (PCS) of the SF36 improved significantly ongoing from 29.2 ± 9.3 at baseline to 56.1 ± 14.9 after 12-months (p = 0.0079) and the mental component score (MCS) improved significantly from 49.2 ± 20.7 at baseline to 62.8 ± 18.9 after 12 months (p = 0.013). CONCLUSIONS: Minimal-invasive lumbar interbody fusion with the new flexible system is a safe and effective treatment method for patients with DDD. Complication rates are low and treatment leads to an improvement of pain, functional impairment and quality of life.