Clinical outcome after lumbar spinal fusion surgery in degenerative spondylolisthesis: a 3-year follow-up.

INTRODUCTION: Lumbar spinal fusion surgery is a widely accepted surgical treatment in degenerative causes of lumbar spondylolisthesis. The benefit of reduction of anterior displacement and restoration of sagittal parameters is still controversially debated. Purpose of the underlying publication was to analyze the influence of radiographic sagittal parameters of the spine in aspects of changes in postoperative clinical outcome. MATERIALS AND METHODS: By prospective analysis, we included patients with low-grade degenerative lumbar spondylolisthesis (Meyerding grades I and II) with mono- or bisegmental fusion surgery with a minimum follow-up data of 3 years. For clinical outcome measures, COMI, ODI and EQ-5D were used. Spinopelvic parameters (sacral inclination, pelvic tilt, sacral slope and pelvic incidence, lumbar lordosis and lumbar index as well as anterior displacement and sagittal rotation) were measured on plain radiographs. RESULTS: We could observe a significant benefit in clinical outcome after lumbar fusion surgery in low-grade spondylolisthesis in our mid-term follow-up data including 32 patients. By surgical reduction, we could see significant restoration of anterior displacement and sagittal rotation. Interestingly, a significant correlation between restoration of both sagittal rotation and sacral inclination and clinical outcome score was observed in the 3-year follow-up. CONCLUSION: In low-grade spondylolisthesis, spinal fusion surgery is a well-established surgical procedure; however, the impact of sagittal parameters and reduction of anterior displacement remains controversial. Within our findings, restoration of sagittal parameters showed significant correlation to improvement in clinical outcome in our mid-term follow-up data.

Outbreak of Pseudomonas aeruginosa infections after CT-guided spinal injections.

BACKGROUND: Meningitis and spinal infections with Gram-negative bacteria after local injections for treatment of chronic back pain are rare. This study investigated an outbreak of Pseudomonas aeruginosa infections following computed tomography (CT)-guided spinal injections (SI). METHODS: A case was defined as a spinal infection or meningitis with P. aeruginosa after SI between 10th January and 1st March 2019 in the same outpatient clinic. Patients without microbiological evidence of P. aeruginosa but with a favourable response to antimicrobial therapy active against P. aeruginosa were defined as probable cases. FINDINGS: Twenty-eight of 297 patients receiving CT-guided SI during the study period developed meningitis or spinal infections. Medical records were available for 19 patients. In 15 patients, there was microbiological evidence of P. aeruginosa, and four patients were defined as probable cases. Two of 19 patients developed meningitis, while the remaining 17 patients developed spinal infections. The median time from SI to hospital admission was 8 days (interquartile range 2-23 days). Patients mainly presented with back pain (N=18; 95%), and rarely developed fever (N=3; 16%). Most patients required surgery (N=16; 84%). Seven patients (37%) relapsed and one patient died. Although the source of infection was not identified microbiologically, documented failures in asepsis when performing SI probably contributed to these infections. CONCLUSIONS: SI is generally considered safe, but non-adherence to asepsis can lead to deleterious effects. Spinal infections caused by P. aeruginosa are difficult to treat and have a high relapse rate.

Fracture risk of vertebral bodies after cryosurgery using a miniature cryoprobe: A biomechanical in-vitro analysis on human bones.

INTRODUCTION: Due to spinal instability and compressive neurologic deficits surgical management is sometimes necessary in patients with metastatic spinal lesions. However, in some cases open surgery is not possible and minimally invasive procedures, like cryoablation, are needed. The aim of the current study was to investigate whether a miniature cryoprobe provides adequate tissue cooling in vertebrae and to evaluate the direct impact of cryosurgery on vertebral body stability. MATERIALS AND METHODS: Twelve thoracic vertebral bodies were harvested from fresh cadavers. After documenting bone density cryoablation was performed in six vertebral bodies according to a standardized procedure. Afterwards temperature inside the vertebral body and maximum breaking force were measured in the control and experimental groups. RESULTS: Required temperature of -50° was reached in all areas. There was a significant correlation between maximum breaking force and measured bone density (p= 0.001). Mean breaking force within the experimental group was 5047 N (SD = 2955 N) compared to 4458 N (SD = 2554 N) in the control group. There were no observable differences in maximum breaking force between both groups. CONCLUSION: Miniature cryoprobe can deliver adequate tissue cooling to -50°C in vertebral bodies. The procedure does not seem to influence breaking force of the treated bones in-vitro. Therefore, using miniature probes cryosurgery may provide a valuable alternative to conventional surgical resection of neoplastic diseases as well as of benign locally aggressive bone tumors.

Predictive validity of preoperative CT scans and the risk of pedicle screw loosening in spinal surgery.

INTRODUCTION: Pedicle screw fixation is the standard technique for the stabilization of the spine, a clinically relevant complication of which is screw loosening. This retrospective study investigates whether preoperative CT scanning can offer a predictor of screw loosening. METHODS: CT-scan attenuation in 365 patients was evaluated to determine the mean bone density of each vertebral body. Screw loosening or dislocation was determined in CT scans postoperatively using the standard radiological criteria. RESULTS: Forty-five of 365 patients (12.3 %; 24 male, 21 female) suffered postoperative screw loosening (62 of 2038 screws) over a mean follow-up time of 50.8 months. Revision surgeries were necessary in 23 patients (6.3 %). The correlation between decreasing mean CT attenuation in Hounsfield Units (HU) and increasing patient age was significant (p < 0.001). Mean bone density was 116.3 (SD 53.5) HU in cases with screw loosening and 132.7 (SD 41.3) HU in cases in which screws remained fixed. The difference was statistically significant (p = 0.003). CONCLUSION: The determination of bone density with preoperative CT scanning can predict the risk of screw loosening and inform the decision to use cement augmentation to reduce the incidence of screw loosening.

The acromiohumeral distance and the subacromial clearance are correlated to the glenoid version.

BACKGROUND: The acromiohumeral distance (ACHD) is a radiographic parameter for evaluating the presence of a rotator cuff rupture. Previous investigations have demonstrated that several factors may influence the magnitude of the acromiohumeral distance, but glenoid version has not yet been considered. HYPOTHESIS: Our hypothesis was that there is a direct correlation between glenoid version and acromiohumeral distance as well as subacromial clearance. METHODS: Four right glenohumeral joints from adult fresh cadavers were anatomically dissected to the level of the rotator cuff. After fixation to a board and positioning of the humeral head in neutral position, an osteotomy of the glenoid neck was carried out and the version was altered in steps of 5°. The ACHD as well as the subacromial clearance (SAC) were measured for every degree of glenoid version. RESULTS: The ACHD increased with increased anteversion and consistently decreased with increased retroversion of the glenoid. The SAC also depended on glenoid version. Neutral version was associated with a minimal clearance under the anterior third of the acromion, retroversion transferred the minimal SAC posteriorly and anteversion transferred minimal SAC under the coracoacromial ligament. CONCLUSION: Our results indicate that glenoid version correlates directly with the magnitude of ACHD and SAC. Therefore, variations of glenoid version can lead to false interpretations of cuff integrity. TYPE OF STUDY: Biomechanical investigation. LEVEL OF EVIDENCE: Not possible to define.

It is the lateral head tilt, not head rotation, causing an asymmetry of the odontoid-lateral mass interspace.

OBJECTIVE: Asymmetry in odontoid-lateral mass interspace in trauma patients is a common finding that regularly leads to additional diagnostic work-up, since its dignity is not entirely clear. There is little evidence in the literature that atlantoaxial asymmetry is associated with C1-C2 instability or (sub) luxation. Asymmetry in odontoid-lateral mass interspace seems to occur occasionally in healthy individuals and patients suffering a cervical spine injury. Congenital abnormalities in odontoid-lateral mass asymmetry may mimic an atlantoaxial asymmetry. The center of C1-C2 rotation is based in the peg of dens axis; therefore, a C1-C2 rotational influence seems unlikely. So far, no study examined the influence of C0-C1-C2 tilt to an asymmetry in odontoid-lateral mass interspace. SUBJECTS AND METHODS: In order to determine if rotation or tilt influences the lateral atlantodental interval (LADI) and to estimate physiologic values, we examined 300 CT scans of the cervical spine. RESULTS: The mean LADI was 3.57 mm and the mean odontoid-lateral mass asymmetry was 1.0 mm. Head position during CT examination was found to be rotated in 39 % of the cases in more than 5°. Subsequent mean C0/C2 rotation was 4.6°. There was no significant correlation between atlantoaxial asymmetry and head rotation (p = 0.437). The average tilt of C0-C1-C2 was found to be 2°. We found a significant correlation between tilt of C0-C1-C2 and asymmetry in odontoid-lateral mass interspace (p = 0.000). CONCLUSION: We conclude that an atlantoaxial asymmetry revealed in CT scans of the cervical spine occurs occasionally. Since head tilt correlates with an atlantoaxial asymmetry, it is crucial to perform cervical spine CT scans in a precise straight head position.

Lumbar lordosis and sacral slope in lumbar spinal stenosis: standard values and measurement accuracy.

STUDY DESIGN: Radiological study. PURPOSE: To asses standard values, intra- and interobserver reliability and reproducibility of sacral slope (SS) and lumbar lordosis (LL) and the correlation of these parameters in patients with lumbar spinal stenosis (LSS). METHODS: Anteroposterior and lateral X-rays of the lumbar spine of 102 patients with LSS were included in this retrospective, radiologic study. Measurements of SS and LL were carried out by five examiners. Intraobserver correlation and correlation between LL and SS were calculated with Pearson's r linear correlation coefficient and intraclass correlation coefficients (ICC) were calculated for inter- and intraobserver reliability. In addition, patients were examined in subgroups with respect to previous surgery and the current therapy. RESULTS: Lumbar lordosis averaged 45.6° (range 2.5°-74.9°; SD 14.2°), intraobserver correlation was between Pearson r = 0.93 and 0.98. The measurement of SS averaged 35.3° (range 13.8°-66.9°; SD 9.6°), intraobserver correlation was between Pearson r = 0.89 and 0.96. Intraobserver reliability ranged from 0.966 to 0.992 ICC in LL measurements and 0.944-0.983 ICC in SS measurements. There was an interobserver reliability ICC of 0.944 in LL and 0.990 in SS. Correlation between LL and SS averaged r = 0.79. No statistically significant differences were observed between the analyzed subgroups. CONCLUSION: Manual measurement of LL and SS in patients with LSS on lateral radiographs is easily performed with excellent intra- and interobserver reliability. Correlation between LL and SS is very high. Differences between patients with and without previous decompression were not statistically significant.

[Surgical options of metastatic spine tumors]. / Chirurgische Therapiemöglichkeiten bei Wirbelkörpermetastasen.

Spinal metastases are a common concomitant phenomenon of advanced tumor disease. Beside the lung and liver, the spine is the third most common localization of manifestation. Apart from chronic and increasing pain, spinal metastases lead to neurological deficits due to destruction of the vertebral body and subsequent epidural growth expansion. The aim of a surgical treatment is the reduction of pain and the maintenance of neurological function as well as spine stability. The indication for surgery should be determined individually in an interdisciplinary consultation. The purpose of this article was to provide a brief overview regarding diagnostics and therapy of metastatic spine tumors.

[Inferior vena cava thrombosis after laparoscopy]. / Thrombose der Vena cava Inferior nach Diagnostischer Laparoskopie.

HISTORY AND FINDINGS: A previously healthy 43-year-old woman was admitted because of pain in the lower abdomen. Abdominal and transvaginal ultrasound revealed a cystic structure in the right ovary, providing the indication for an exploratory laparoscopy. A hemorrhagic corpus luteum was enucleated. Laboratory tests had merely shown a raised C-reactive protein level and marginally elevated leukocytes. A family history of thrombotic episodes had been elicited. FURTHER COURSE, DIAGNOSIS AND TREATMENT: Although heparin had been applied increasing swelling developed in both thighs and lower legs at day six, indicating thrombosis of the inferior vena cava. Laboratory tests revealed a mutation in factor V (Leiden). Computed tomography showed complete thrombotic IVC occlusion. Thrombolytic treatment with recombinant tissue plasminogen was initiated, direct thrombus aspiration attempted and a filter inserted in the IVC. Low molecular heparin was infused, replaced by oral anticoagulation with phenprocoumon. Subsequent Doppler ultrasound examination demonstrated almost complete resolution of the thrombus, except for a few small residual thrombi. CONCLUSION: This case demonstrates that even minor laparoscopic interventions carry the risk of an IVC thrombosis as a late complication, indicating appropriate measures to prevent thrombosis.