Harry Merk

Full-endoscopic interlaminar and transforaminal lumbar discectomy versus conventional microsurgical technique: a prospective, randomized, controlled study.

Study Design. Prospective, randomized, controlled study of patients with lumbar disc herniations, operated either in a full-endoscopic or microsurgical technique. Objective. Comparison of results of lumbar discectomies in full-endoscopic interlaminar and transforaminal technique with the conventional microsurgical technique. Summary of Background Data. Even with good results, conventional disc operations may result in subsequent damage due to trauma. Endoscopic techniques have become the standard in many areas because of the advantages they offer intraoperatively and after surgery. With the transforaminal and interlaminar techniques, 2 full-endoscopic procedures are available for lumbar disc operations. Methods. One hundred seventy-eight patients with full-endoscopic or microsurgical discectomy underwent follow-up for 2 years. In addition to general and specific parameters, the following measuring instruments were used: VAS, German version North American Spine Society Instrument, Oswestry Low-Back Pain Disability Questionnaire. Results. After surgery 82% of the patients no longer had leg pain, and 14% had occasional pain. The clinical results were the same in both groups. The recurrence rate was 6.2% with no difference between the groups. The full-endoscopic techniques brought significant advantages in the following areas: back pain, rehabilitation, complications, and traumatization. Conclusion. The clinical results of the full-endoscopic technique are equal to those of the microsurgical technique. At the same time, there are advantages in the operation technique and reduced traumatization. With the surgical devices and the possibility of selecting an interlaminar or posterolateral to lateral transforaminal procedure, lumbar disc herniations outside and insidethe spinal canal can be sufficiently removed using the full-endoscopic technique, when taking the appropriate criteria into account. Full-endoscopic surgery is a sufficient and safe supplementation and alternative to microsurgical procedures.

Full-Endoscopic Cervical Posterior Foraminotomy for the Operation of Lateral Disc Herniations Using 5.9-mm Endoscopes : A Prospective, Randomized, Controlled Study

Study Design. Prospective, randomized, controlled study of patients with lateral cervical disc herniations, operated either in a full-endoscopic posterior or conventional microsurgical anterior technique. Objective. Comparison of results of cervical discectomies in full-endoscopic posterior foraminotomy technique with the conventional microsurgical anterior decompression and fusion. Summary of Background Data. Anterior cervical decompression and fusion is the standard procedure for operation of cervical disc herniations with radicular arm pain. Mobility-preserving posterior foraminotomy is the most common alternative in the case of lateral localization of the pathology. Despite good clinical results, problems may arise due to traumatization of the access. Endoscopic techniques are considered standard in many areas, since they may offer advantages in surgical technique and rehabilitation. These days, all disc herniations of the lumbar spine can be operated in full-endoscopic technique. With the full-endoscopic posterior cervical foraminotomy a procedures is available for cervical disc operations. Methods. One hundred and seventy-five patients with full-endoscopic posterior or microsurgical anterior cervical discectomy underwent follow-up for 2 years. In addition to general and specific parameters, the following measuring instruments were used: VAS, German version North American Spine Society Instrument, Hilibrand Criteria. Results. After surgery 87.4% of the patients no longer had arm pain, and 9.2% had occasional pain. The clinical results were the same in both groups. There were no significant difference between the groups in the revision or complication rate. The full-endoscopic technique brought advantages in operation technique, preserving mobility, rehabilitation, and traumatization. Conclusion. The recorded results show that the full-endoscopic posterior foraminotomy is a sufficient and safe supplement and alternative to conventional procedures when the indication criteria are fulfilled. At the same time, it offers the advantages of a minimally invasive intervention.

Surgical treatment for lumbar lateral recess stenosis with the full-endoscopic interlaminar approach versus conventional microsurgical technique: a prospective, randomized, controlled study.

OBJECT Extensive decompression with laminectomy where appropriate is often still described as the method of choice in surgery for lateral recess stenosis. Nonetheless, tissue-sparing procedures are becoming more common. Endoscopic techniques have become the standard in many areas because of the advantages they offer in surgical technique and in rehabilitation. Transforaminal and interlaminar access provide 2 full-endoscopic (FE) techniques for lumbar spine surgery. The goal of this prospective randomized controlled study was to compare the surgical results for the FE technique via the interlaminar approach with those of the conventional microsurgical technique in patients with degenerative lateral recess stenosis. METHODS A total of 161 patients with FE or microsurgical decompression underwent follow-up for 2 years. In addition to general and specific parameters, the following measuring instruments were used: visual analog scale, German version of the North American Spine Society instrument, and the Oswestry low-back pain disability questionnaire. RESULTS The results show that 74.5% of patients reported no longer having leg pain, and 20.5% had only occasional pain. The clinical results were the same in both groups. The rate of complications and revisions was significantly reduced in the FE group. The FE techniques brought advantages in the following areas: operation, complications, traumatization, and rehabilitation. CONCLUSIONS The clinical results of the FE interlaminar technique are equal to those of the microsurgical technique. At the same time, there are advantages in the operation technique, such as reduced traumatization. The FE interlaminar spinal decompression procedure is a sufficient and safe supplement and alternative to microsurgical procedures.

Recurrent lumbar disc herniation after conventional discectomy: a prospective, randomized study comparing full-endoscopic interlaminar and transforaminal versus microsurgical revision.

Study Design Prospective, randomized, controlled study of patients with recurrent lumbar disc herniations after conventional discectomy, operated either in a full-endoscopic or microsurgical technique. Objective Comparison of results of lumbar revision discectomies in full-endoscopic interlaminar and transforaminal technique with the conventional microsurgical technique. Summary of Background Data Recurrences after lumbar disc operations cannot be prevented. Because of the existing scarring, the risk of intraoperative complications may be increased and consecutive damage may arise owing to greater traumatization. In disc surgery, tissue-sparing interventions are becoming more widespread. Endoscopic techniques have become the standard in many areas because of the advantages they offer intraoperatively and postoperatively. With the transforaminal and interlaminar techniques, 2 full-endoscopic procedures are available for the lumbar spine. Methods Eighty-seven patients with recurrent herniation after conventional discectomy underwent full-endoscopic or microsurgical intervention and were followed for 2 years. In addition to general and specific parameters, the following measuring instruments were used: visual analog scale, German version of the North American Spine Society Instrument, Oswestry Low-Back Pain Disability Questionnaire. Results Postoperatively, 79% of the patients no longer had leg pain, and 16% had occasional pain. The clinical results were the same in both groups. The re-recurrence rate was 5.7% with no difference between the groups. The full-endoscopic techniques brought significant advantages in the following areas: rehabilitation, complications, and traumatization. Conclusions The clinical results of the full-endoscopic technique are equal to those of the microsurgical technique. At the same time, there are advantages in the operation technique and reduced traumatization. With the surgical devices and the possibility of selecting an interlaminar or posterolateral to lateral transforaminal procedure, recurrent lumbar disc herniations can be sufficiently removed using the full-endoscopic technique. Full-endoscopic surgery is a sufficient and safe supplementation and alternative to microsurgical procedures.

Treatment of vertebral osteomyelitis by radical debridement and stabilization using titanium mesh cages.

Study Design. A retrospective clinical and radiologic evaluation of patients with vertebral osteomyelitis treated via radical debridement and stabilization using titanium mesh cages. Objective. To assess the efficacy of titanium mesh cages in the treatment of active vertebral osteomyelitis. Summary of Background Data. Although titanium mesh cages have proven to be superior in trauma and tumor reconstructions, there are few reports regarding the use of titanium mesh cages in the presence of active pyogenic or tuberculotic vertebral osteomyelitis. Methods. A total of 88 cases with vertebral osteomyelitis were operated on between January 2000 and December 2002. There were 2 craniocervical, 13 cervical, 19 thoracic, 11 thoracolumbar, and 43 lumbar infections. The titanium mesh cages replaced 1 disc in 34 cases, 1 vertebral body in 28 cases, 2 vertebral bodies in 23 cases, and 3 vertebral bodies in 3 cases. Results. All patients showed a solid bony fusion without any recurrence of infection at latest follow-up. Changes in pain score, Frankels classification, and blood parameters demonstrated a significant clinical improvement in all patients. The sagittal profile was restored. Conclusions. The use of titanium mesh cages in the treatment of vertebral osteomyelitis effectively reconstructs the anterior column, while adding stability and restoring the sagittal profile. There is no increase in the rate of recurrence or persistence of infection related to the implantation of titanium mesh cages.

Auricular acupuncture for pain relief after ambulatory knee surgery: a randomized trial

Background: Auricular acupuncture is a promising method for postoperative pain relief. However, there is no evidence for its use after ambulatory surgery. Our aim was to test whether auricular acupuncture is better than invasive needle control for complementary analgesia after ambulatory knee surgery. Methods: One hundred and twenty patients undergoing ambulatory arthroscopic knee surgery under standardized general anesthesia were randomly assigned to receive auricular acupuncture or a control procedure. Fixed indwelling acupuncture needles were inserted before surgery and retained in situ until the following morning. Postoperative rescue analgesia was directed to achieve pain intensity less than 40 mm on a 100-mm visual analogue scale. The primary outcome measure was the postoperative requirement for ibuprofen between surgery and examination the following morning. Results: Intention-to-treat analysis showed that patients from the control group (n = 59) required more ibuprofen than patients from the auricular acupuncture group (n = 61): median (interquartile range) 600 (200–800) v. 200 (0–600) mg (p = 0.012). Pain intensity on a visual analogue scale was similar in both groups at all time points registered. The majority of patients in both groups believed that they had received true acupuncture and wanted to repeat it in future. Interpretation: Auricular acupuncture reduced the requirement for ibuprofen after ambulatory knee surgery relative to an invasive needle control procedure.

Nerve Root Sedimentation Sign : Evaluation of a New Radiological Sign in Lumbar Spinal Stenosis

Study Design. Retrospective case-referent study. Objective. To assess whether the new sedimentation sign discriminates between nonspecific low back pain (LBP) and symptomatic lumbar spinal stenosis (LSS). Summary of Background Data. In the diagnosis of LSS, radiologic findings do not always correlate with clinical symptoms, and additional diagnostic signs are needed. In patients without LSS, we observe the sedimentation of lumbar nerve roots to the dorsal part of the dural sac on supine magnetic resonance image scans. In patients with symptomatic and morphologic central LSS, this sedimentation is rarely seen. We named this phenomenon “sedimentation sign” and defined the absence of sedimenting nerve roots as positive sedimentation sign for the diagnosis of LSS. Methods. This study included 200 patients. Patients in the LSS group (n = 100) showed claudication with or without LBP and leg pain, a cross-sectional area <80 mm2, and a walking distance <200 m; patients in the LBP group (n = 100) had LBP, no leg pain, no claudication, a cross-sectional area of the dural sac >120 mm2, and a walking distance >1000 m. The frequency of a positive sedimentation sign was compared between the 2 groups, and intraobserver and interobserver reliability were assessed in a random subsample (n = 20). Results. A positive sedimentation sign was identified in 94 patients in the LSS group (94%; 95% confidence interval, 90%–99%) but none in the LBP group (0%; 95% confidence interval, 0%–4%). Reliability was kappa = 1.0 (intraobserver) and kappa = 0.93 (interobserver), respectively. There was no difference in the detection of the sign between segmental levels L1–L5 in the LSS group. Conclusion. A positive sedimentation sign exclusively and reliably occurs in patients with LSS, suggesting its usefulness in clinical practice. Future accuracy studies will address its sensitivity and specificity. If they confirm the signs high specificity, a positive sedimentation sign can rule in LSS, and, with a high sensitivity, a negative sedimentation sign can rule out LSS.

Bilateral operation of lumbar degenerative central spinal stenosis in full-endoscopic interlaminar technique with unilateral approach: prospective 2-year results of 74 patients.

Study Design Prospective study of the patients with degenerative spinal central stenosis, operated bilateral in a full-endoscopic unilateral technique. Objective The objective of this prospective study was to examine the technical possibilities of full-endoscopic interlaminar bilateral technique with unilateral approach in degenerative lumbar central spinal stenosis and predominant leg symptoms using new designed endoscopes and instruments. Summary of Background Data Extensive decompression with laminectomy where appropriate, is often still described as the method of choice in the operation of degenerative lumbar spinal stenosis. Nonetheless, tissue-sparing procedures are becoming more common. Endoscopic techniques have become the standard in many areas because of the advantages they offer in surgical technique and in rehabilitation. At the spine, 1 essential point was the developing of the instruments for sufficient bone resection under continuous visual control. This enabled the use in the operation of spinal canal stenoses. Methods A total of 72 patients with lumbar central spinal stenosis full-endoscopic unilateral decompression were followed for 2 years. In addition to general and specific parameters, these measuring instruments were used: VAS, German version North American Spine Society Instrument, Oswestry Low-back Pain Disability Questionnaire. Results The results show that 70.8% no longer have leg pain or it was nearly completely reduced and 22.2% have occasional pain. The decompression results were equal to those of conventional procedures. The complication rate was low. The full-endoscopic techniques brought advantages in these areas: operation, complications, traumatization, and rehabilitation. Conclusions The recorded results show that the full-endoscopic interlaminar bilateral decompression with unilateral approach is a sufficient and safe supplement and alternative to conventional procedures when the indication criteria are fulfilled. At the same time, it offers the advantages of a minimally invasive intervention.

Changes in content and synthesis of collagen types and proteoglycans in osteoarthritis of the knee joint and comparison of quantitative analysis with Photoshop-based image analysis

IntroductionThe different cartilage layers vary in synthesis of proteoglycan and of the distinct types of collagen with the predominant collagen Type II with its associated collagens, e.g. types IX and XI, produced by normal chondrocytes. It was demonstrated that proteoglycan decreases in degenerative tissue and a switch from collagen type II to type I occurs. The aim of this study was to evaluate the correlation of real-time (RT)-PCR and Photoshop-based image analysis in detecting such lesions and find new aspects about their distribution.PatientsWe performed immunohistochemistry and histology with cartilage tissue samples from 20 patients suffering from osteoarthritis compared with 20 healthy biopsies. Furthermore, we quantified our results on the gene expression of collagen type I and II and aggrecan with the help of real-time (RT)-PCR. Proteoglycan content was measured colorimetrically. Using Adobe Photoshop the digitized images of histology and immunohistochemistry stains of collagen type I and II were stored on an external data storage device. The area occupied by any specific colour range can be specified and compared in a relative manner directly from the histogram using the “magic wand tool” in the select similar menu. In the image grow menu gray levels or luminosity (colour) of all pixels within the selected area, including mean, median and standard deviation, etc. are depicted. Statistical Analysis was performed using the t test.MethodWith the help of immunohistochemistry, RT-PCR and quantitative RT- PCR we found that not only collagen type II, but also collagen type I is synthesized by the cells of the diseased cartilage tissue, shown by increasing amounts of collagen type I mRNA especially in the later stages of osteoarthritis.ResultsA decrease of collagen type II is visible especially in the upper fibrillated area of the advanced osteoarthritic samples, which leads to an overall decrease. Analysis of proteoglycan showed a loss of the overall content and a quite uniform staining in the different zones compared to the healthy cartilage with a classical zonal formation. Correlation analysis of the proteoglycan Photoshop measurements with the RT-PCR using Spearman correlation analysis revealed strong correlation for Safranin O and collagen type I, medium for collagen type II and glycoprotein but weak correlation between PCR aggrecan results.ConclusionPhotoshop-based image analysis might become a valuable supplement for well known histopathological grading systems of lesioned articular cartilage.

Semiquantitative analysis of ECM molecules in the different cartilage layers in early and advanced osteoarthritis of the knee joint

The study was conducted to examine the expression of collagen type I and II in the different cartilage layers in relation to other ECM molecules during the progression of early osteoarthritic degeneration in human articular cartilage (AC). Quantitative real-time (RT)-PCR and colorimetrical techniques were used for calibration of Photoshop-based image analysis in detecting such lesions. Immunohistochemistry and histology were performed with 40 cartilage tissue samples showing mild (ICRS grade 1b) respectively moderate/advanced (ICRS grade 3a or 3b) (20 each) osteoarthritis compared with 15 healthy biopsies. Furthermore, we quantified our results on the gene expression of collagen type I and II and aggrecan with the help of real-time (RT)-PCR. Proteoglycan content was measured colorimetrically. The digitized images of histology and immunohistochemistry stains were analyzed with Photoshop software. T-test and Spearman correlation analysis were used for statistical analysis. In the earliest stages of AC deterioration the loss of collagen type II was associated with the appearance of collagen type I, shown by increasing amounts of collagen type I mRNA. During subsequent stages, a progressive loss of structural integrity was associated with increasing deposition of collagen type I as part of a natural healing response. A decrease of collagen type II is visible especially in the upper fibrillated area of the advanced osteoarthritic samples, which then leads to an overall decrease. Analysis of proteoglycan showed losses of the overall content and a loss of the classical zonal formation. Correlation analysis of the proteoglycan Photoshop measurements with the RT-PCR revealed strong correlation for Safranin O and collagen type I, medium for collagen type II, alcian blue and glycoprotein but weak correlation with PCR aggrecan results. Photoshop based image analysis might become a valuable supplement for well known histopathological grading systems of lesioned articular cartilage. The evidence of collagen type I production early in the OA disease process coupled with the ability of chondrocytes to up-regulate collagen type II production suggests that therapeutic agents that suppress collagen type I production and increase collagen type II production may enable chondrocytes to generate a more effective repair response.