Computer tomography assessment of pedicle screw placement in lumbar and sacral spine: comparison between free-hand and O-arm based navigation techniques.

Transpedicular screw fixation has been accepted worldwide since Harrington et al. first placed pedicle screws through the isthmus. In vivo and in vitro studies indicated that pedicle screw insertion accuracy could be significantly improved with image-assisted systems compared with conventional approaches. The O-arm is a new generation intraoperative imaging system designed without compromise to address the needs of a modern OR like no other system currently available. The aim of our study was to check the accuracy of O-arm based and S7-navigated pedicle screw implants in comparison to free-hand technique described by Roy-Camille at the lumbar and sacral spine using CT scans. The material of this study was divided into two groups, free-hand group (group I) (30 patients; 152 screws) and O-arm group (37 patients; 187 screws). The patients were operated upon from January to September 2009. Screw implantation was performed during PLIF or TLIF mainly for spondylolisthesis, osteochondritis and post-laminectomy syndrome. The accuracy rate in our work was 94.1% in the free-hand group compared to 99% in the O-arm navigated group. Thus it was concluded that free-hand technique will only be safe and accurate when it is in the hands of an experienced surgeon and the accuracy of screw placement with O-arm can reach 100%.

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.

Rheumatological manifestations of hepatitis C: incidence in a rheumatology and non-rheumatology setting and the effect of methotrexate and interferon.

OBJECTIVES: To evaluate hepatitis C virus (HCV)-positive patients followed in a rheumatology department and to compare them with a similar population of HCV-positive patients who had never seen a rheumatologist, in order to describe the rheumatological symptoms present and the effects of methotrexate and interferon-alpha therapy. METHODS: We performed a retrospective study of clinical, radiological and biological data on 21 rheumatology patients (Group I) presenting symptoms consistent with a chronic inflammatory arthritis with a known HCV infection and compared them with 41 members of an HCV support association (Group II). RESULTS: Symptoms of myalgia, sicca syndrome, Raynaud's phenomenon or paraesthesias were similarly frequent in the two groups. However, inflammatory joint pain and joint swelling were more common in Group I. In this group rheumatoid factor was positive in 48%, antinuclear antibodies in 26%, cryoglobulin in 44% and a reduced complement level in 63%. The majority of patients from Group I treated with methotrexate demonstrated an amelioration of the rheumatological symptoms with few negative outcomes. Regarding interferon-alpha therapy and rheumatological symptoms-in Groups I and II respectively 50 and 66% demonstrated a deterioration, 33 and 30% showed no change and 17 and 4% showed an amelioration. CONCLUSION: Rheumatological symptoms are common in patients chronically infected with HCV. It is essential to individualize the role of treatment with interferon-alpha and to consider the use of methotrexate for difficult cases.

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.

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).