Occipital bone thickness: Implications on occipital-cervical fusion. A cadaveric study.

OBJECTIVE: The aim of this study was to create a map of the occipital bone using a cadaveric morphometric analysis. MATERIAL: Twelve heads, from seven male and five female cadavers, were studied. The thickness of the occipital bone was measured with a digital vernier caliper within a coordinate system. RESULTS: The maximum thickness of the occipital bone could be measured at the external occipital protuberance (mean 15.4 mm; range 9-29.3 mm). All male individuals had higher bone thickness around this point. Further lateral a steady decrease of bone thickness could be observed. Same could be observed in craniocaudal direction. However, values above the superior nuchal line were on average thicker than below. CONCLUSION: The measurements demonstrated a great individual variability of bone thickness of the occipital bone. The results emphasize the role of preoperative planning for the feasibility of placement of an occipital screw.

Indications and contraindications: interspinous process decompression devices in lumbar spine surgery.

BACKGROUND: Interspinous process decompression devices (IPD) allow a minimally invasive treatment of lumbar spinal stenosis (LSS), but their use is discussed highly controversial. Several level I studies suggest that IPD implantation is a viable alternative for both conservative treatment and decompression, but clear indications and contraindications are still missing. This study was designed to explore the perspectives and limitations of IPDs and to evaluate the role of these devices in general. MATERIAL AND METHODS: The study is based on a questionnaire sent to all hospitals registered in the German Hospital Address Register 2010 with an orthopedic, neurosurgerical, or spine surgery department (n = 1,321). The questionnaire was reviewed by experienced spine surgeons and statisticians, and included both single-response, close-ended, and multiple-response open-ended questions. RESULTS: We received 329 (24.9%) entirely analyzable questionnaires. A total of 164 respondents (49.8%) stated that IPDs are a treatment option for LSS, and 135 of the 164 respondents (82.3%) use them. Poor clinical experience (60%) and lack of evidence (53.9%) are the main reasons cited for not using IPDs. We detected a high negative correlation between the size of the hospital, the number of outpatients and inpatients treated for LSS and other spine pathologies, and the use of IPDs (p = 0.001). Most respondents prefer the combination of open decompression and IPD (64.4%; n = 87). A total of 9.6% (n = 13) of the users favor IPD implantation as a stand-alone procedure. Overall, 25.9%  n = 35 use both options. Most surgeons aim to relieve the facet joints (87.7%) and to stabilize a preexisting instability (75.4%). They recommend IPDs in the segments L2-L3 (77%), L3-L4 (98.5%), and L4-l5 (99.3%) and consider that IPD implanation also could be done at the L5-S1 segment (40.1%). Overall, 64.4% (n = 87) of the users recommend limiting IPD implantation to two segments. Infection (96.3%), fracture (94.8%), isthmic spondylolisthesis (77%), degenerative spondylolisthesis (higher than Meyerding I [57%]), lumbar spine scoliosis (48.1%), and osteoporosis (50.4%) are seen as contraindications for IPD. CONCLUSION: No clear consensus exists among spine surgeons concerning the use of IPD for LSS treatment. The study showed that hospital-related parameters also influence decision making for or against the use of IPDs. However, despite the lack of evidence, the indications and contraindications which had been identified in the present study might contribute to improved outcomes after IPD implantation or at least prevent harm to patients.

Single-Shot Epidural Injections in the Management of Radicular Pain.

Epidural injections are commonly used in the treatment of chronic low back pain due to symptomatic lumbar spinal disorders. The aim of the present investigation was to study their therapeutic value for different age subgroups. A consecutive series of 356 patients were treated with at least one injection, and assessed before and after injection. Significant pain reduction was observed in all age groups following a series of injections with the greatest reduction after the first one. Especially in patients younger than 50 years, pain medication could be reduced substantially. Surgery was performed in 19.4% of patients (n=69) following a series of SSPDA injections. In the current study, interlaminar steroid injections for treatment of chronic low back and radicular pain caused sufficient improvement and significant reduction of medication especially in younger patients.

Evaluation of efficacy of a new hybrid fusion device: a randomized, two-centre controlled trial.

BACKGROUND: The 360° fusion of lumbar segments is a common and well-researched therapy to treat various diseases of the spine. But it changes the biomechanics of the spine and may cause adjacent segment disease (ASD). Among the many techniques developed to avoid this complication, one appears promising. It combines a rigid fusion with a flexible pedicle screw system (hybrid instrumentation, "topping off"). However, its clinical significance is still uncertain due to the lack of conclusive data. METHODS/DESIGN: The study is a randomized, therapy-controlled, two-centre trial conducted in a clinical setting at two university hospitals. If they meet the criteria, outpatients presenting with degenerative disc disease, facet joint arthrosis or spondylolisthesis will be included in the study and randomized into two groups: a control group undergoing conventional fusion surgery (PLIF - posterior lumbar intervertebral fusion), and an intervention group undergoing fusion surgery using a new flexible pedicle screw system (PLIF + "topping off"), which was brought on the market in 2013. Follow-up examination will take place immediately after surgery, after 6 weeks and after 6, 12, 24 and 36 months. An ongoing assessment will be performed every year.Outcome measurements will include quality of life and pain assessments using validated questionnaires (ODI - Ostwestry Disability Index, SF-36™ - Short Form Health Survey 36, COMI - Core Outcome Measure Index). In addition, clinical and radiologic ASD, sagittal balance parameters and duration of work disability will be assessed. Inpatient and 6-month mortality, surgery-related data (e.g., intraoperative complications, blood loss, length of incision, surgical duration), postoperative complications (e.g. implant failure), adverse events, and serious adverse events will be monitored and documented throughout the study. DISCUSSION: New hybrid "topping off" systems might improve the outcome of lumbar spine fusion. But to date, there is a serious lack of and a great need of convincing data on safety or efficacy, including benefits and harms to the patients, of these systems. Health care providers are particularly interested in such data as these implants are much more expensive than conventional implants. In such a case, randomized clinical trials are the best way to evaluate benefits and risks. TRIAL REGISTRATION: NCT01852526.

From embouchure problems to embouchure dystonia? A survey of self-reported embouchure disorders in 585 professional orchestra brass players.

OBJECTIVES: Data concerning embouchure problems in professional brass players are scarce. Embouchure problems can potentially lead to focal dystonia. The aim of this study was to investigate the frequency of distinct embouchure problems in professional brass players. Furthermore, the frequency of "cramping", a distinct symptom of embouchure dystonia, was evaluated in the context of established embouchure dystonia risk factors. METHODS: Five hundred and eighty-five professional brass players participated in a cross-sectional study concerning embouchure problems. A self-administered questionnaire was developed to evaluate embouchure fatigue, embouchure disorders and their consequences. To study the association between risk factors and cramping (a symptom of embouchure dystonia), a log-binomial regression analysis was conducted, enabling estimation of prevalence ratios (PR) and 95 % confidence intervals (95 % CI). RESULTS: Thirty percent (95 % CI 25.9-33.3) reported embouchure fatigue. The relative frequency of embouchure disorders was 59 % (95 % CI 54.6-63.6), with 26 % (95 % CI 22.4-29.5) reporting embouchure cramping. Embouchure disorders resulted in sick leave in 16 % (95 % CI 12.7-20.6). Female brass players (PR 2.0, 95 % CI 0.98-3.98) and musicians with a prior change in their embouchure (PR 2.4, 95 % CI 1.38-4.05) or breathing technique (PR 2.2, 95 % CI 1.25-3.72) and musicians with embouchure fatigue (PR 1.9, 95 % CI 1.18-2.93) presented more frequently with embouchure cramping than musicians with other or without risk factors. CONCLUSION: This study shows a high relative frequency of embouchure problems in professional brass players. Given that embouchure dystonia is often preceded by embouchure problems, these findings may assist in gaining further insight into the characteristics of embouchure dystonia and the development of preventive strategies.

Is there a stable vertebral height restoration with the new radiofrequency kyphoplasty? A clinical and radiological study.

PURPOSE: The aim of this study is to evaluate whether radiofrequency kyphoplasty can restore vertebral body height in osteoporotic vertebral fractures and whether restoration of vertebral height correlates with decreased pain. METHODS: In a prospective study from December 2010 to October 2011, 25 patients underwent RF kyphoplasty for 30 fresh osteoporotic vertebral fractures. The parameter demographics, pain relief, restoration of vertebral body height (mean vertebral body height, kyphosis angle, anterior/posterior edge height) and all complications were recorded. RESULTS: Mean age of patients was 73.8 ± 9.6 (range, 55-83); time from initial painful fracture to treatment was 3.0 weeks ± 1.2; average operative time was 23.5 min (range, 15-41). Average pain index score decreased significantly from 69 ± 8.5 preoperatively to 34.4 ± 5.9 postoperatively (p < 0.001), and to 30 ± 6.3 (p < 0.001) after 3 months. Mean vertebral body height, anterior edge height and kyphosis angle showed significant increases postoperatively and at 3-month follow-up (p < 0.05). In two vertebrae (6.6 %), minimal, asymptomatic cement leakage occurred in the upper disc. After 2 months, one new fracture (3.3 %) was identified in the directly adjacent segment that was also successfully treated with radiofrequency kyphoplasty. There was a preliminary correlation between mean vertebral body height elevation and cement volume (r = 0.533). CONCLUSION: Radiofrequency kyphoplasty achieves rapid and lasting improvement in clinical symptoms. There was stable restoration of vertebral body height with a mean cement volume of 3.0 ml ± 0.6. There was no correlation between restoration of vertebral body height and pain relief.

Complications of vertebroplasty and kyphoplasty in the treatment of vertebral fractures: results of a questionnaire study.

Percutaneous vertebroplasty (VP) and balloon kyphoplasty (BKP) are minimally invasive procedures performed to stabilize vertebral fractures. With continuing expansion in clinical use, a broad spectrum of complications has been reported for both interventions. The goal of the current study was to compare the safety of these procedures using a questionnaire completed by practitioners. A questionnaire was developed with multiple choice and open questions. General data as well as information regarding complications which occurred during the year 2007 were requested. The incidence and odds ratios (OR) of complications for both procedures were analysed. One hundred and sixteen questionnaires detailing 3216 VP and 5139 BKP procedures were included for evaluation. The risk of cement extrusion from the vertebra (OR 2.64, p <0.01) and into the spinal canal (OR 435, p <0.01) was markedly increased for VP. The odds ratio for neurologic complications (OR 2.56, p = 0.1) and secondary fracture (OR = 0.99, p = 0.96) did not indicate significant predisposition for either procedure. Secondary fracture occurred in 5% of VP and 5.1% of BKP procedures. Overall, 80% of practitioners subjectively considered BKP the safer procedure. Overall, BKP appears safer than VP. Symptomatic complications are rare with both procedures. Additional prospective data is necessary to reach more definitive conclusions.

Quality of life and radiological outcome after cervical cage fusion and cervical disc arthroplasty.

In this retrospective comparative study, 42 patients with single-level cervical radiculopathy were operated upon, either with Shell cage fusion (23 patients) or with Prestige cervical disc arthroplasty (19 patients). The mean follow-up (FU) was 17.5 months (range: 5.6-42.1 months). Both treatments significantly improved all clinical parameters (VAS, ODI, SF36) (p < 0.001), without statistically relevant differences between the two groups. From a radiological viewpoint there was an obvious but statistically non-significant increase in the segmental height for both treatment groups. Segmental angle also increased in both groups, and the increase was significant (p < 0.05). As expected, range of motion (ROM) decreased significantly (p < 0.05) in the fusion group, while it was preserved in the arthroplasty group. Significantly more (p < 0.05) adjacent level degeneration class 1 to 4 was evident in the fusion group (8/23 or 34.8%) than in the arthroplasty group (3/19 or 15.8%). Two fusion patients (2/23 or 8.7%) developed painful clinical adjacent level disease requiring arthroplasty. The major conclusion was that significant adjacent level degenerative changes occurred in the cage group. Retained motion at the operative site seems to decrease the incidence of adjacent level degeneration. Implant subsidence was recorded at FU in 8 out of 42 patients (19%). It occurred significantly (p < 0.05) more often in the fusion group (6/23 or 26.1%) than in the arthroplasty group (2/19 or 10.5%), but it did not cause clinical symptoms. As in other studies, there is no explanation as to why better radiological results did not translate into better clinical outcomes within the time limits of the study.

Treatment of spondylodiscitis.

PURPOSE: Pyogenic infections of the spine are relatively rare with an incidence between 1:100,000 and 1:250,000 per year, but the incidence is increasing due to increases in average life-expectancy, risk factors, and medical comorbidities. The mean time in hospital varies from 30 to 57 days and the hospital mortality is reported to be 2-17%. This article presents the relevant literature and our experience of conservative and surgical treatment of pyogenic spondylodiscitis. METHOD: We have performed a review of the relevant literature and report the results of our own research in the diagnosis and treatment of pyogenic spondylodiscitis. We present a sequential algorithm for identification of the pathogen with blood cultures, CT-guided biopsies and intraoperative tissue samples. Basic treatment principles and indications for surgery and our surgical strategies are discussed. RESULTS: Recent efforts have been directed toward early mobilisation of patients using primary stable surgical techniques that lead to a further reduction of the mortality. Currently our hospital mortality in patients with spondylodiscitis is around 2%. With modern surgical and antibiotic treatment, a relapse of spondylodiscitis is unlikely to occur. In literature the relapse rate of 0-7% has been recorded. Overall the quality of life seems to be more favourable in patients following surgical treatment of spondylodiscitis. CONCLUSION: With close clinical and radiological monitoring of patients with spondylodiscitis, conservative and surgical therapies have become more successful. When indicated, surgical stabilisation of the infected segments is mandatory for control of the disease and immediate mobilisation of the patients.

Is there an increased stem migration or compromised osteointegration of the Mayo short-stemmed prosthesis following cerclage wiring of an intrasurgical periprosthetic fracture?

AIM: Short-stemmed prostheses are increasingly regarded as implants of first choice in primary THA. As a result of the press-fit fixation in the femoral metaphysis, the occurrence of intraoperative fractures were reported. The aim of this study was to analyze the postoperative results of the Mayo short-stem prosthesis following treatment of an intrasurgical femur fracture with cerclage wiring. PATIENTS AND METHODS: From 1999 to 2005, in 38 patients (18 females, 20 males; mean age 56 years; mean BMI = 27) with the diagnosis of coxarthrosis in whom a Mayo short-stemmed prosthesis has been implanted, an intraoperative fracture was observed. The fractures were treated with cerclage wiring (1 cerclage, n = 32; 2 cerclages, n = 5; 3 cerclages, n = 1). Postoperatively, all patients were prescribed mobilization without weight-bearing (floor contact) on the treated leg for 6 weeks. Using the Wristing software, longitudinal stem migration and varus-valgus femoral stem alignment were examined digitally in anteroposterior X-rays taken immediately after surgery, after 6 weeks and on average after 5.7 years (Zeh et al., Z Orthop Unfall 149:200-205, 2011). Additionally, the incidence of periprosthetic radiolucent lines was captured in the anteroposterior X-rays and assigned to the Gruen zones. Additionally, a DEXA scan was performed. The X-rays of a matched control group after the implantation of a Mayo prosthesis without femur fracture were analyzed by the same method. RESULTS: There was no significant migration of the Mayo prosthesis in the study or control groups during postoperative follow-up (t test, P > 0.05). The cerclage group compared with the control group showed a statistically significant valgus tilt of 1.5° on average during the follow-up, which is regarded to be clinically not relevant. The frequency of occurrence of radiolucent lines was not statistically different (chi-square test, χ = 0.42, P = 0.51). DEXA scans showed no differences of the bone mineral density in the Gruen zones compared with a historical control group. CONCLUSION: After wiring of an intrasurgical fracture, no disadvantage could be proven for Mayo prosthesis regarding stem migration and varus-valgus alignment. Furthermore, due to the absence of differences in the occurrence of radiolucent lines and the same results in the DEXA scan, an unimpaired osseointegration is assumed.

Multilevel spinal fusion in the aged: not a panacea.

The authors conducted a retrospective study on the outcome after multilevel spine fusion in elderly patients. Seventy-two out of 80 patients were available after a mean follow-up period of 29.4 months. There were 47 females and 25 males. Their mean age at operation was 68.7 years, which means that many complaints may have been due to an underlying osteoporosis, unresponsive to surgical treatment, and exposing to loosening of the implants. The outcome was indeed rather poor: only 50% of the patients were satisfied. VAS and ODI improved slightly, but not significantly. Implant loosening was the main complication: it occurred in 35 patients, but necessitated re-operation in only 8. Adjacent segment degeneration (ASD) occurred in 26 patients, and necessitated re-operation in 17. This study should be a warning against an interventionist attitude in older patients with so-called spondylosis, where osteoporosis should be excluded and, if present, should be treated as a first step.

Effects of impaction on cement mantle and trabecular bone in hip resurfacing.

INTRODUCTION: Failures involving the femoral part in hip resurfacing remain problematic in terms of overall implant survival. In this context, effects of impaction strength on cement mantle morphology and trabecular bone damage have not been studied to date. MATERIALS AND METHODS: Sixteen paired cadaveric femora that had undergone hard and gently impacted hip resurfacing using a manual packing cementing technique in a previous study, were evaluated morphologically. The earlier study had revealed lower failure loads for hard impacted heads. A central slice of each femoral head underwent microradiography. RESULTS: Overall cement mantle thickness averaged 2.0 mm (range 0-5 mm) in the hard and in the low impact group with no significant difference between groups (p = 0.299). No signs of damage in the bone remnants inside the prosthesis of the fractured proximal femurs were detected in the microradiographic analysis. CONCLUSION: Cement mantle thickness was not influenced by impaction strength when using a manual packing cementing technique. No trabecular damage underneath the implant was detected despite lower failure loads, confirming the difficulty to identify small trabecular damage in an in vitro study.

Dorsal resection of a thoracic hemivertebra in a 4-year-old boy with endochondral gigantism. A case report.

The authors present what appears to be the first case of congenital kyphosis due to a T12 hemivertebra in a four-year-old boy with endochondral gigantism syndrome of unknown origin. Because of his overgrowth, the patient had severe medical and orthopaedic problems and was almost immobile. Prior to surgery, he experienced a rapidly progressive thoracolumbar kyphosis to 600 (T10-L2). MRI of the brain and spine showed critical protraction of the spinal cord and myelopathy from compression at T12. Single-stage posterior resection of the hemivertebra with spinal shortening and dorsal transpedicular instrumentation of T10-L2 was performed. Although the bone tissue was cartilaginous and dysplastic, 420 (30%) correction was achieved along with decompression of the spinal canal. The patient experienced no neurological impairment post-operatively. At follow-up examination 1.5 year after surgery, the patient's movement disorder had improved markedly and he was able to stand and walk. This very rare case demonstrates that single-stage posterior hemivertebra resection and transpedicular instrumentation for correction of congenital kyphosis can be a safe and effective procedure even in a very challenging case.

Computed tomography measurements of the lumbar spinous processes and interspinous space.

PURPOSE: This study examines the anatomic proportions of the interspinous space and the spinous processes, considering the optimal placement of an interspinous spacer. METHODS: Between January 2008 and December 2009, 565 patients undergoing computed tomography (CT) scans of the abdomen for various reasons were collected retrospectively for the study. Using the CT scan data, spinous processes of the lumbar spine L1-5 and the interspinous spaces T12-L5 were measured. RESULTS: The average measured interspinous space was 9.1 ± 2.5 mm. This space became significantly (p < 0.001) smaller from anterior to posterior. Average cortical thickness of all lumbar spinous processes was 2.5 ± 0.5 mm. Cortical thickness decreased significantly (p < 0.001) from anterior to posterior. The cortex of the spinous processes from L2 (2.67 ± 0.45 mm) and L3 (2.66 ± 0.94 mm) was significantly thicker (p < 0.001) than that of the others. The spinous process of L5 had the thinnest (p < 0.001) cortex (2.10 ± 0.41 mm), as well as the smallest (p < 0.001) volume (3.0 ± 1.0 ml) and the shortest (p < 0.001) height (16.6 ± 3.6 mm). CONCLUSIONS: The spinous processes of L2 and L3 are the largest and sturdiest, and that of L5 is the weakest. The L4/5 segment features the smallest interspinous space with the thinnest cortex of all lumbar spinous processes. Because the interspinous space narrows posteriorly and the cortex is thicker anteriorly, it seems that the best anatomic position for a stand alone interspinous spacers is anterior.

Pulmonary cement embolism after augmentation of pedicle screws with bone cement.

The authors present the very rare complication of widespread pulmonary artery cement embolism after pedicle screw augmentation with bone cement for multilevel spine fusion. A 69-year-old woman with severe osteoporosis underwent a posterior T12S1fusion because of lumbar scoliosis. After two months the superior pedicle screws loosened, and a revision spondylodesis T8L1 was performed with bone cement augmentation of the pedicle screws. Although cement leakage was seen paravertebrally, the patient was asymptomatic and reported distinct pain relief, so that no further investigations were initiated. Three months later, instability was identified in the adjacent superior segment. A CT-scan of the chest now revealed multiple pulmonary cement embolisms. Corpectomy T7 and extension spondylodesis T6T9 with an anterior single rod were performed. The pulmonary embolisms remained clinically silent and lung function was normal 18 months after surgery. The risk for cement embolism after pedicle screw augmentation has been established at 1/119 or 0.8%. After vertebroplasty and kyphoplasty it ranges from 3 to 23%. The existing literature offers no clear strategy for prevention or treatment of pulmonary cement embolism. The authors feel, as far as prevention is concerned, that creating a cavity by means of balloon distention before pedicle screw augmentation allows to inject the cement under lower pressure, so that the incidence of cement embolism might be reduced. Treatment options include, besides surgical removal in symptomatic embolism, heparin or warfarin treatment for 3 to 6 months.

Indications and contraindications for vertebroplasty and kyphoplasty.

INTRODUCTION: Vertebral fractures (VF) are a leading cause of morbidity in the elderly. In the past decade, minimally invasive bone augmentation techniques for VF, such as percutaneous vertebroplasty (VP) and kyphoplasty (KP) have become more widespread. According to the literature, both techniques provide significant pain relief. However, KP is more expensive and technically more demanding than VP. The current study surveyed German surgeons who practice percutaneous augmentation to evaluate and compare decisions regarding the implementation of these techniques. Is there a difference in the indications and contraindications of VP and KP compared with the interdisciplinary consensus paper on VP and KP of the German medical association in the treatment of VF? METHODS: A multiple choice questionnaire was designed with questions regarding diagnostic procedures, clinical and radiologic (AO classification) indications, as well as contraindications for both VP and KP. A panel of five experts refined the initial questionnaire. The final version was then sent to 580 clinics registered to practice KP in Germany. The statistical analysis was done by two authors, who collected the questionnaire data and Wilcoxon's signed ranks test was performed for non-parametric variables with SPSS. RESULTS: 327 of 580 questionnaires (56.4%) were completed and returned. 151 (46.2%) of participants were performing both procedures, and 176 (53.8%) performed KP only. Median duration from onset of acute pain to intervention was 3 weeks. For most participants (95.4%), consistent back pain at the fracture level with a visual analog scale score over 5 was the main clinical indication for VP and KP. A1 and A3.1 fractures from osteoporosis and metastasis were considered indications for KP. Osteoporotic A1.1 fractures were an indication for VP. Traumatic A3.2 fractures were not an indication for either procedure. Major contraindications to both procedures were active infection (94.7%), cement allergy (86.8%), and coagulation disorders (80.3%). CONCLUSION: Vertebroplasty and kyphoplasty both have roles in the treatment of vertebral fractures. However, we could see differences in the indications for the two percutaneous techniques. Participants of this study found more indications for KP versus VP in cases of painful A1.2 and A3.1 fractures due to osteoporosis, metastasis, and trauma. About half of the respondents reported that VP is indicated for osteoporotic and pathologic A1.1 fractures. This study offers only limited conclusions. Open questionnaires and prospective data from all clinicians performing these procedures should be analyzed to offer more specific information.

Mid-range outcomes in 64 consecutive cases of multilevel fusion for degenerative diseases of the lumbar spine.

In the treatment of multilevel degenerative disorders of the lumbar spine, spondylodesis plays a controversial role. Most patients can be treated conservatively with success. Multilevel lumbar fusion with instrumentation is associated with severe complications like failed back surgery syndrome, implant failure, and adjacent segment disease (ASD). This retrospective study examines the records of 70 elderly patients with degenerative changes or instability of the lumbar spine treated between 2002 and 2007 with spondylodesis of more than two segments. Sixty-four patients were included; 5 patients had died and one patient was lost to follow-up. We evaluated complications, clinical/radiological outcomes, and success of fusion. Flexion-extension and standing X-rays in two planes, MRI, and/or CT scans were obtained pre-operatively. Patients were assessed clinically using the Oswestry disability index (ODI) and a Visual Analogue Scale (VAS). Surgery performed was dorsolateral fusion (46.9%) or dorsal fusion with anterior lumbar interbody fusion (ALIF; 53.1%). Additional decompression was carried out in 37.5% of patients. Mean follow-up was 29.4±5.4 months. Average patient age was 64.7±4.3 years. Clinical outcomes were not satisfactory for all patients. VAS scores improved from 8.6±1.3 to 5.6±3.0 pre- to post-operatively, without statistical significance. ODI was also not significantly improved (56.1±22.3 pre- and 45.1±26.4 post-operatively). Successful fusion, defined as adequate bone mass with trabeculation at the facets and transverse processes or in the intervertebral segments, did not correlate with good clinical outcomes. Thirty-five of 64 patients (54%) showed signs of pedicle screw loosening, especially of the screws at S1. However, only 7 of these 35 (20%) complained of corresponding back pain. Revision surgery was required in 24 of 64 patients (38%). Of these, indications were adjacent segment disease (16 cases), pedicle screw loosening (7 cases), and infection (one case). At follow-up of 29.4 months, patients with radiographic ASD had worse ODI scores than patients without (54.7 vs. 36.6; P<0.001). Multilevel fusion for degenerative disease still has a high rate of complications, up to 50%. The problem of adjacent segment disease after fusion surgery has not yet been solved. This study underscores the need for strict indication guidelines to perform lumbar spine fusion of more than two levels.

How does spinal canal decompression and dorsal stabilization affect segmental mobility? A biomechanical study.

INTRODUCTION: When decompression of the lumbar spinal canal is performed, segmental stability might be affected. Exactly which anatomical structures can thereby be resected without interfering with stability, and when, respectively how, additional stabilization is essential, has not been adequately investigated so far. The present investigation describes kinetic changes in a surgically treated motion segment as well as in its adjacent segments. MATERIAL AND METHODS: Segmental biomechanical examination of nine human lumbar cadaver spines (L1 to L5) was performed without preload in a spine-testing apparatus by means of a precise, ultrasound-guided measuring system. Thus, samples consisting of four free motion segments were made available. Besides measurements in the native (untreated) spine specimen further measurements were done after progressive resection of dorsal elements like lig. flavum, hemilaminectomy, laminectomy and facetectomy. The segment was then stabilised by means of a rigid system (ART((R))) and by means of a dynamic, transpedicularly fixed system (Dynesys((R))). RESULTS: For the analysis, range of motion (ROM) values and separately viewed data of the respective direction of motion were considered in equal measure. A very high reproducibility of the individual measurements could be verified. In the sagittal and frontal plane, flavectomy and hemilaminectomy did not achieve any relevant change in the ROM in both directions. This applies to the segment operated on as well as to the adjacent segments examined. Resection of the facet likewise does not lead to any distinct increase of mobility in the operated segment as far as flexion and right/left bending is concerned. In extension a striking increase in mobility of more than 1degree compared to the native value can be perceived in the operated segment. Stabilization with the rigid and dynamic system effect an almost equal reduction of flexion/extension and right/left bending. In the adjacent segments, a slightly higher mobility is to be noted for rigid stabilization than for dynamic stabilisation. A linear regression analysis shows that in flexion/extension monosegmental rigid stabilisation is compensated predominantly in the first cranial adjacent segment. In case of a dynamic stabilisation the compensation is distributed among the first and second cranial, and by 20% in the caudal adjacent segment. SUMMARY: Monosegmental decompression of the lumbar spinal canal does not essentially destabilise the motion segment during in vitro conditions. Regarding rigid or dynamic stabilisation, the ROM does not differ within the operated segment, but the distribution of the compensatory movement is different.

Spondylodiscitis in the elderly patient: clinical mid-term results and quality of life.

INTRODUCTION: Focusing on spondylodiscitis in elderly patients current literature does not contain much information. METHOD: We performed a retrospective case series (n = 32) comparing conservative (group 1; n = 16) versus operative (group 2; n = 16) treated spondylodiscitis patients aged > or =65 years (mean age 74.9 years) from January 2002 to April 2004. The review of the medical records provided information about the pre-hospital time, the inpatient course and the time after discharge. At follow-up (FU) (mean 3.6 years) disease specific and general quality of life (QOL) questionnaires (COMI back patient self-assessment, ODI and SF-36) were administered. RESULTS: Altogether, 71.9% of the patients could be contacted; 12.5% had died since hospitalisation and 15.6% could not be contacted anymore. At FU based on the visual analogue scale, patients indicated an average of 3.2 for back pain and 2.5 for leg pain. ODI scoring yielded minimal disability for 38.9%, a moderate disability for 22.2%, a severe disability for 22.2% and for 11.1% a crippled situation; 5.6% were bed-ridden or exaggerated their symptoms. The SF-36 PCS amounted to an average of 38.2, the MCS 50.6. Owing to additional surgery-associated risks, operative treatment of spondylodiscitis feature a complication rate twice as high in the respective group, but general complications do not differ. At FU, no statistically remarkable difference concerning QOL and remaining pain became evident between the groups, the operated patients being more satisfied with regard to the treatment of spondylodiscitis. CONCLUSION: Ultimately, if surgery is indicated the operative risks should be borne in mind, but advanced age should not be the crucial factor in decision-making.

Interspinous implants (X Stop, Wallis, Diam) for the treatment of LSS: is there a correlation between radiological parameters and clinical outcome?

Neurogenic intermittent claudication, caused by lumbar spinal stenosis (LSS), usually occurs after the age of 50 and is one of the most common degenerative spinal diseases in the elderly. Among patients over the age of 65 with LSS, open decompression is the most frequently performed spinal operation. The recently introduced interspinous spacers are a new alternative under discussion. In this retrospective study, we reviewed medical records and radiographs of patients with LSS and NIC treated from June 2003 to June 2007. All included patients (n = 129) were treated with interspinous implants (X Stop Wallis, or Diam). Evaluations of pain, using a visual analog scale (VAS), and radiographic signs, using two-plane X-rays of the lumbar spine, were performed preoperatively (preop), postoperatively (postop) and after discharge (FU 2-3). Gender ratio (m:w) was 1.1:1. Mean age of the patients was 60.8 +/- 16.3 years. Foraminal height, foraminal width, foraminal cross-sectional area, intervertebral angle, as well as anterior and posterior disc height changed significantly (P < 0.0001) after implantation of the interspinous device. Postoperatively, symptom relief (VAS) was significant (P < 0.0001). The X Stop implant improved (in some cases significantly) the radiographic parameters of foraminal height, width, and cross-sectional area, more than the Diam and Wallis implants; however, there was no significant difference among the three regarding symptom relief. FU 1 was on average 202.3 +/- 231.9 and FU 2 527.2 +/- 377.0 days postoperatively. During FU, the radiological improvements seemed to revert toward initial values. Pain (VAS) did not increase despite this "loss of correction." There was no correlation between age and symptom improvement. There was only very weak correlation between the magnitude of radiographic improvement and the extent of pain relief (VAS). The interspinous implant did not worsen low-grade spondylolisthesis. Provided there is a strict indication and fusion is not required, implantation of an interspinous spacer is a good alternative to treat LSS. The interspinous implant offers significant, longlasting symptom control, even if initially significant radiological changes seem to revert toward the initial values ("loss of correction").