Dynamic posterior stabilization for degenerative lumbar spine disease: a large consecutive case series with long-term follow-up by additional postal survey.

INTRODUCTION: Dynamic stabilization of the degenerated spine was invented to overcome the negative side effects of fusion surgery like adjacent segment degeneration. Amongst various different implants DSS(®) is a pedicle-based dynamic device for stabilizing the spine and preserving motion. Nearly no clinical data of the implant have been reported so far. The current analysis presents results from a single spine surgeon who has been using DSS(®) for the past 5 years and recorded all treatment and outcome data in the international Spine Tango registry. MATERIALS/METHODS: From the prospectively documented overall patient pool 436 cases treated with DSS(®) could be identified. The analysis was enhanced with a mailing of COMI patient questionnaires for generating longer-term follow-ups up to 4 years. RESULTS: 387 patients (189 male, 198 female; mean age 67.3 years) with degenerative lumbar spinal disease including degenerative spondylolisthesis (6.1 %) could be evaluated. The type of degeneration was mainly spinal stenosis (89.9 %). After a mean follow-up of 1.94 years, the COMI score and NRS back and leg pain improved significantly and to a clinically relevant extent. The postoperative trend analysis could not determine a relevant deterioration of these outcomes until 4 years postoperative. 10 patients were revised (2.6 %) and the implant was removed; in most cases, a fusion was performed. Another 5 cases (1.3 %) had an extension of the dynamic stabilization system to the adjacent level. 84.2 % of patients rated that the surgery had helped a lot or had helped. DISCUSSION: The results of this large consecutive series with a follow-up up to 4 years could demonstrate a good and stable clinical outcome after posterior dynamic stabilization with DSS(®). For degenerative diseases of the lumbar spine, this treatment seems to be a valid alternative to fusion surgery.

Computer tomography assessment of pedicle screw placement in thoracic spine: comparison between free hand and a generic 3D-based navigation techniques.

INTRODUCTION: Although pedicle screw fixation is a well-established technique for the lumbar spine, screw placement in the thoracic spine is more challenging because of the smaller pedicle size and more complex 3D anatomy. The intraoperative use of image guidance devices may allow surgeons a safer, more accurate method for placing thoracic pedicle screws while limiting radiation exposure. This generic 3D imaging technique is a new generation intraoperative CT imaging system designed without compromise to address the needs of a modern OR. AIM: The aim of our study was to check the accuracy of this generic 3D navigated pedicle screw implants in comparison to free hand technique described by Roy-Camille at the thoracic spine using CT scans. MATERIAL AND METHODS: The material of this study was divided into two groups: free hand group (group I) (18 patients; 108 screws) and 3D group (27 patients; 100 screws). The patients were operated upon from January 2009 to March 2010. Screw implantation was performed during internal fixation for fractures, tumors, and spondylodiscitis of the thoracic spine as well as for degenerative lumbar scoliosis. RESULTS: The accuracy rate in our work was 89.8 % in the free hand group compared to 98 % in the generic 3D navigated group. CONCLUSION: In conclusion, 3D navigation-assisted pedicle screw placement is superior to free hand technique in the thoracic spine.

Comparison of a minimally invasive procedure versus standard microscopic discotomy: a prospective randomised controlled clinical trial.

A Prospective randomised controlled study was done to determine statistical difference between the standard microsurgical discotomy (MC) and a minimally invasive microscopic procedure for disc prolapse surgery by comparing operation duration and clinical outcome. Additionally, the transferability of the results was determined by a bicentric design. The microscopic assisted percutaneous nucleotomy (MAPN) has been advocated as a minimally invasive tubular technique. Proponents have claimed that minimally invasive procedures reduce postoperative pain and accelerate the recovery. In addition, there exist only a limited number of well-designed comparison studies comparing standard microdiscotomy to a tubular minimally invasive technique that support this claim. Furthermore, there are no well-designed studies looking at the transferability of those results and possible learning curve phenomena. We studied 100 patients, who were planned for disc prolapse surgery at two centres [50 patients at the developing centre (index) and 50 patients at the less experienced (transfer) centre]. The randomisation was done separately for each centre, employing a block-randomisation procedure with respect to age and preoperative Oswestry score. Operation duration was chosen as a primary outcome parameter as there was a distinguished shortening observed in a preliminary study at the index centre enabling a sound case number estimation. The following data were compared between the two groups and the centres with a 12-month follow-up: surgical times (operation duration and approach duration), the clinical results, leg and back pain by visual analogue scale, the Oswestry disability index, length of hospital stay, return to work time, and complications. The operation duration was statistically identical for MC (57.8 +/- 20.2 min) at the index centre and for MAPN (50.3 +/- 18.3 min) and MC (54.7 +/- 18.1 min) at the transfer centre. The operation duration was only significantly shorter for the MAPN technique at the index centre with 33.3 min (SD 12.1 min). There was a huge clinical improvement for all patients regardless of centre or method revealed by a repeated measures ANOVA for all follow-up visits Separate post hoc ANOVAs for each centre revealed that there was a significant time-method (MAPN vs. MC) interaction at the index centre (F = 3.75, P = 0.006), whereas this crucial interaction was not present at the transfer centre (F = 0.5, P = 0.7). These results suggest a slightly faster clinical recovery for the MAPN patients only at the index centre. This was due to a greater reduction in VAS score for back pain at discharge, 8-week and 6-month follow up (P < 0.002). The Oswestry-disability scores reached a significant improvement compared to the initial values extending over the complete follow-up at both centres for both methods without revealing any differences for the two methods in either centre. There was no difference regarding complications. The results demonstrate that a shorter operation duration and concomitant quicker recovery is comprehensible at an experienced minimally invasively operating centre. These advantages could not be found at the transfer centre within 25 minimally invasive procedures. In conclusion both procedures show equal mid term clinical results and the same complication rate even if the suggested advantages for the minimally invasive procedure could not be confirmed for the transfer centre within the framework of this study.

[First experience and preliminary clinical results with the cervical disc replacement DISCOVER]. / Erste Erfahrungen und vorläufige klinische Ergebnisse mit der zervikalen Bandscheibenprothese DISCOVER.

AIM: The Discover (DePuy Spine, Raynham, MA, USA) is a newly developed device for cervical disc replacement that is available since 2007 in the EU. To date there are no clinical studies on the Discover. Preliminary clinical and intraoperative results from a pilot study should be compared with data for other commonly used prostheses. METHOD: In a prospective study 70 patients underwent cervical disc surgery in 2007. Clinical parameters were the neck disability index (NDI), VAS for neck and arm pain and neurological deficits. The segmental angles were determined by Cobb's method preoperatively and after 12 months. Intraoperative parameters like time of surgery and blood loss as well as complications during the postoperative course were recorded. Clinical controls after 8 weeks, 6 and 12 months were done. RESULTS: Mean age was 44.3 years. In total, 101 devices in 70 patients (27 two level, 2 three level) were implanted. Average time for surgery amounted to 68 minutes per patient and 54 minutes per prosthesis. Average blood loss was 80 mL. There were no intraoperative complications. All patients, except for 3 surgical revisions, were examined clinically and radiologically after 8 weeks, 6 and 12 months. Study parameters like NDI and VAS for arm and neck pain showed a significant (p < 0.001) improvement at all follow-ups compared to the preoperative situation. However, the value of VAS for arm pain in the follow-up rose again significantly (p < 0.05). The motor deficit improved in 33% completely and in 67% incompletely. Sensory disturbances were unchanged in 17%, improved in 73% and completely resolved in 10%. The average segmental angle improved from 3.1 degrees preoperatively to 5.3 degrees (p < 0.05) after 12 months. Up to the end of the follow-up 8.6% complications were recorded. These were 1 temporary dysphonia and 3 surgical revisions due to translations of the devices (4.3%) and 2 heterotopic ossifications (2.8%). CONCLUSION: This is the first study on the Discover. The results of clinical scores, intraoperative data and complications are encouraging and comparable to those from other commonly used types of cervical disc replacement. Regarding the duration of surgery, the correction of segmental angle and the amount of heterotopic ossifications, the Discover proved to be advantageous. However, for a definitive evaluation the follow-up period is still too short.

Analysis of reoperations after surgical treatment of degenerative cervical spine disorders: a report on 900 cases.

UNLABELLED: Surgery on the degenerative cervical spine disorders aims at decompression of the neural structures and restoring the physiological profile of the cervical spine. The aims of internal fixation are to gain primary stability, introduce a bony fusion and to correct the shape of the spine. The present study will give answers to the following questions: 1. What is the overall revision rate following an operative treatment of degenerative cervical disorders using common operative techniques? 2. Is there any influence of the fusion length to the overall revision rate and especially to the decompensation ratio of adjacent segments? 3. What is the rate of revisions due to instrumentation failures? 4. Are there any differences concerning the revision rate between posterior and anterior instrumentation? MATERIAL: We reviewed 900 patients, who underwent a cervical spine surgery with an internal fixation between January 1994 and December 2000. METHODS: Five different operative techniques were used: type I (mono-and bisegmental intersomatic decompression and fusion using anterior instrumentation), type II (multisegmental intersomatic decompression and fusion using anterior instrumentation), type III (multisegmental anterior intersomatic decompression and fusion with posterior instrumentation), type IV (one-level corpectomy with vertebral body replacement and anterior instrumentation) and type V (multi-level corpectomy with vertebral body replacement and posterior instrumentation). The minimum follow up period was 2.2 years (mean 4.2 years). RESULTS: In total, 121 revisions (13.4%) were recorded. The main indication for revision was implant failure in 5.4%. Operations type I showed the lowest revision rate (11%), while type V operations showed the highest revision rate (32%). CONCLUSIONS: The influence of the fusion length on the revision rate was unexpectedly high. Adjacent level decompensation was neither influenced by the length of the fusion nor the performed procedure. Compared to anterior instrumentation, posterior instrumentation showed a tendency for a lower revision rate without statistical significance. However, the posterior procedures showed a high revision rate regarding to wound healing problems.

A less invasive posterior approach for the management of extended secondary epidural abscess technical note.

Spondylodiscitis is considered to be the main cause of epidural abscess. In this report, the authors present their concept for the management of the extended epidural abscess that occurs in combination with spondylodiscitis. It consists of debridement and fusion for spondylodiscitis together with epidural abscess drainage using a microscopically assisted percutaneous technique. In the period from April 2000 to April 2004, 5 patients with spondylodiscitis and an accompanying extended epidural abscess were operated on. The mean age of the patients was 66 years. There were 4 males and one female. The follow-up period ranged from 3-12 months. To manage the extended epidural abscess, the authors created one or two drainage sites along the extension of epidural abscess. These drainage sites were made using a microscopically assisted percutaneous approach. In all presented cases, the offending organism was Staphylococcus aureus. The postoperative infection markers showed marked regression. The postoperative control MRI demonstrated effective drainage of the extended epidural abscess. Regarding the neurological deficits, 3 patients previously classified as Frankel C showed an improvement to Frankel E within 3 months postoperatively. From these results, it seems that our technique (ventro-dorsal abscess drainage combined with a microscopically assisted percutaneous approach) could be a successful method for the management of the extended epidural abscess associated with spondylodiscitis.

[Long-term results of the anatomic stem "Euroform"]. / Langzeitergebnisse des anatomischen Titanhüftschaftes "Euroform"

PURPOSE: To date there is a lack of long-term results of anatomic hip stems in the literature. In this context we present our 10-year results with the hip stem "Euroform". METHODS: In a retrospective cohort study 90% of the 51 stems implanted in our institute in the years 1993/94 51 stems were reexamined. Of them 39 were implanted cement-free while 11 were cemented. RESULTS: After 10 to 12 years no revision surgery of the cement-free stems was necessary or performed because of stem problems, in one case of a cemented stem revision was done because of cup problems. The survival rate for the complete prostheses was 97.5% after 10 years and 92% after 12 years. The revision surgery was done for cup problems. The satisfaction rate was "1.9" (according to the German school ranking system), the Merle d'Aubigné score was "good" (>10 points). However, one problem was the high rate of PE deterioration which depended on the inclination. CONCLUSION: Both the cemented and the cement-free forms of the "Euroform" stem gives good long-term results. The longevity of the prostheses is limited by polyethylene wear.

[Does timing of thoracic spine stabilization influence perioperative lung function after trauma?]. / Der Einfluss des Versorgungszeitpunktes von Frakturen der Brustwirbelsäule auf die perioperative respiratorische Funktion.

BACKGROUND: Proper timing of stabilization for spine injuries is discussed controversially. Whereas early repair of long bone fractures is known to reduce complications. PATIENTS AND METHODS: We investigated retrospectively 48 patients who were stabilized in a ventrodorsal approach for fractures of the thoracic spine. Patients were divided into three groups. All patients in groups I and II presented radiological or clinical signs of lung contusion. Patients were stabilized in the prone position via single-step dorsal stabilization with internal transpedicular fixation and ventral fusion with titanium cage or autologous bone graft using a minimally invasive video-assisted thoracotomy. RESULTS: The average duration of the procedures in group I was 213+/-40 min, in group II 250+/-75 min, and in group III 255+/-65 min (p: n.s.). Intraoperative blood loss did not differ significantly between the three groups. The PaO(2)/FiO(2) ratio improved in groups I and III, whereas in group II an significant impairment of lung function occurred perioperatively. Postoperative ICU stay was comparable in groups I and II (I: 10+/-5 days; II: 9+/-7 days); overall ICU stay tended to be shorter in group I versus II. The postoperative dependence on ventilator support did not differ significantly among the three groups. The mortality rate was 0% in this series. CONCLUSION: Our data provide further evidence that early stabilization of combined thoracic and thoracic spine injuries is safe, does not alter perioperative lung function, and results in a reduced overall ICU stay.

Mini-open approach combined with percutaneous transarticular screw fixation for C1-C2 fusion.

This paper describes a limited exposure for posterior C1-C2 arthrodesis aided by percutaneous transarticular fixation. The purpose of this study was to report the fusion rate using the aforementioned method. Fifty-seven patients (54 females and three males) with C1-C2 instability due to rheumatoid disease constituted the material of this study. The exposure was restricted to C0-C3 levels. The drilling and insertion of the screws was done through two mini stab wounds. A special sleeve and screwdriver were developed to facilitate this step. An autogenous iliac bone graft was fixed between the decorticated posterior arch of the atlas and the lamina of the axis vertebra. The mean of the atlantodental interval decreased from 8.5 mm (SD 2.3 mm) to 2.6 mm (SD 0.6 mm) at the immediate postoperative periods and reached 2.7 mm (SD 0.7 mm) after a mean follow-up of 30.4 months (SD 5.6 months). Malposition of the screws was observed in two patients and warranted a second operation in one. Fusion was evident in 98% of the cases. Percutaneous insertion of the screws in posterior C1-C2 transarticular fixation reduces the size of the exposure and the surgical trauma to the cervical segments below the fixation.

[The cervicogenic headache from the spiral surgery point of view--a pilot study]. / Der zervikogene Kopfschmerz aus wirbelsäulenchirurgischer Sicht. Eine Pilotstudie.

In a retrospective analysis of 299 consecutive patients with degenerative cervical spine disease the incidence of cervicogenic headache and the results of conservative and operative therapy have been investigated. Cervicogenic headache was noted in 117 of 299 patients (40%). 73 of those patients were treated conservatively. The cervicogenic headache resolved in 10% or improved in 27% and remained unchanged in 63% of the patients. 44 of these patients were operated by ventral discectomy, which was indicated in case of neurological deficit and painful shoulder-arm syndrome refractory to conservative treatment. In none of these patients the operation was indicated by the cervicogenic headache. In the postoperative follow-up with a mean of 6 months the headache resolved in 20%, improved in 60% and remained unchanged in 20% of the patients. These results suggest the existence of a cervicogenic headache, i.e. a headache due to disorders of the cervical spine, and the chance of successful operative treatment.

A new technique for the treatment of lumbar far lateral disc herniation: technical note and preliminary results.

A newly designed technique for a minimally invasive approach to the laterally herniated disc is presented. Fifteen patients suffering from far lateral disc herniation (extraforaminal) were operated according to this technique. Through a small skin incision (1.5 cm), the paraspinal muscles are spread by dilators, until a working channel of 9 mm inner diameter and 11 mm outer diameter can be placed. The next steps are done through this channel using the surgical microscope. No bone resections are necessary and the facet joints are left untouched. However, partial resection of the intertransverse ligament may be necessary. The mean follow-up period for these 15 patients was 11.5 months, and they were evaluated by using the visual analogue scale (VAS) and the Oswestry Disability Index (ODI). The average surgical time was 43 min. The ODI improved from 30.6 (preoperative) to 14.3 (postoperative). The VAS of leg pain improved from 7 (preoperative) to 3.6 (postoperative), which represented a statistically significant improvement at the significance level of (P<0.01). No intra-operative or early postoperative complications occurred. However, one recurrence did occur, which was treated by the same technique. This technique combines the advantages of three-dimensional visual control (operating microscope) with the minimal surgical trauma of endoscopic techniques, while avoiding some of the shortcomings of both the microsurgical and endoscopic techniques.

Chronic encapsulated intracerebral hematoma--a well-defined disease. Report on two cases and review of the literature.

Chronic encapsulated intracerebral hematoma (CEIH) is a rare disease which is believed to be caused by angiographically negative vascular malformations. CEIH has the following characteristic findings: 1. It affects all age groups 2. Clinical symptoms progress slowly after sudden onset. Often there is a latency of months or years 3. There is no correlation with arterial hypertension 4. Imaging reveals a typical fibrous capsule with enclosed blood contents and signs of recurrent bleedings 5. Cavernoma was identified histologically as the cause of bleeding in 30% of cases. 6. All patients had a primary diagnosis of intracerebral tumor. To the best of our knowledge, 27 cases have been reported in the literature. We now add two cases, one of which is the first in the available literature which was not operated and could be followed by imaging.

[The microscopic assisted percutaneous approach to posterior spine - a new minimally invasive procedure for treatment of spinal processes]. / Der mikroskopisch assistierte perkutane Zugang zur dorsalen Wirbelsäule - Ein neues minimalinvasives Verfahren zur Behandlung von Wirbelsäulenprozessen.

The aim of our attempts and trials was to develop a minimally invasive posterior approach to the spine which utilises the smallest access to the target without additional harmful effects on the stability of the spine and at the same time allows excellent dealing with the lesions depending on the advantage of the operative microscope in providing 3 dimensional view of the operative field. In the period between May 1998 and February 2001, 356 patients were treated for different spinal disorders using this approach. The approach was applied in 299 surgeries for lumbar disc herniation and we called the procedure: microscopic assisted percutaneous nucleotomy (MAPN). The approach was applied in another 34 patients with lumbar canal stenosis to perform what we called microscopic assisted percutaneous decompression (MAPD). The latter was applied for three cases with thoracic canal stenosis and six with cervical canal stenosis. The approach was also applied for other purposes and included myeloscopy in four cases, transpedicular biopsy in six, and transpedicular vertebroplasty in the remaining four. The 43 MAPN done in the early period were re-examined one year after the operation. We achieved 75% good and very good results regarding the relief of the sciatic pain and recovery of the neurological deficits. Re-surgery was necessary in only two cases (4.5%). The results with the use of this technique seem very promising. The minimal trauma induced by this approach allows rapid mobilisation of the patients and short hospital stay. A postoperative back orthoses is not necessary. The technique can also be done under local anaesthesia particularly when needed as in old people with severe co-morbidity.

A new minimally invasive posterior approach for the treatment of cervical radiculopathy and myelopathy: surgical technique and preliminary results.

Degenerative cervical disorders predominantly lead to anterior spinal cord compression (by bony spurs at the posterior margin of the vertebral body or by degenerated disc), which may be central and/or foraminal. In a smaller percentage of cases, there is encroachment of the canal mainly from posterior by bulging yellow ligaments or bony appositions, resulting in compression syndromes of roots or spinal cord. The aim of this work is to present a minimally invasive posterior approach avoiding detachment of muscles for the treatment of cervical radiculopathy and myelopathy. Thirteen patients suffering from cervical radiculopathy (four patients) or myelopathy (nine patients) were operated according to this technique. In principle, the technique secures access to the diseased spinal segment via a percutaneously placed working channel (11 mm outer diameter and 9 mm inner diameter). The cervical paraspinal muscles are not deflected, but just spread between their fibres by special dilators. All further steps are performed through this channel under control of three-dimensional vision through the operating microscope. The mean follow-up period was 17 months (one patient died 9 months postoperatively), and patients were evaluated using a modified version of the Oswestry Index, called the Neck Disability Index (NDI), and the visual analogue scale (VAS) for neck and arm pain. The mean NDI (P<0.0001) improved from 13.2 (preoperatively) to 4.8 (postoperatively). The VAS for arm pain (P<0.001) and for neck pain (P<0.001) also showed marked postoperative improvement. Complete recovery of the preoperative neurological deficit was found in four patients, while the remaining eight patients showed improvement of the neurological symptoms during the follow-up period. There were no intra-operative or postoperative complications and no re-operation. The preliminary experience with this technique, and the good clinical outcome, seem to promise that this minimally invasive technique is a valid alternative to the conventional open exposure for treatment of lateral disc prolapses, foraminal bony stenosis and central posterior ligamentous stenosis of the cervical spine.

A less invasive approach technique for operative treatment of lumbar canal stenosis. Technique and preliminary results.

UNLABELLED: The aim of this prospective study is to evaluate the efficacy of a less invasive approach for the operative treatment of lumbar canal stenosis. Using transmuscular dilatation this technique minimises surgical trauma. Through a working channel with a 11 mm outer diameter and under operative microscope guidance, decompression of the neural elements can be achieved. MATERIAL AND METHODS: From November 1998 to December 2001 38 consecutive patients with a mean age of 73.2 years were operated upon using this technique. The study included 56 lumbar segments. The mean follow up was 32 (18-55) months. The Visual Analogue Scale (VAS) for back and leg pain together with the Oxford Claudication Score (OCS) were used to assess the functional results. RESULTS: The average operating time for one level decompression was 74 minutes and the average blood loss was 32 ml/patient. Two patients (5.2 %) required revision by open surgery. The OCS improved from 29.4 preoperatively to 16.9 postoperatively (p < 0.001). VAS for back pain and leg pain also showed a significant improvement (p < 0.001). CONCLUSIONS: This less invasive approach is effective in decompressing lumbar canal stenosis. It has the advantage of early mobilisation and a short hospital stay, especially in elderly patients (mean age here: 73.2 years).