D Grob

Schulthess Klinik, Zürich, Zürich, Zurich, Switzerland

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Publications (188)601.16 Total impact

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    ABSTRACT: The last few decades have witnessed a paradigm shift in the assessment of outcome in spine surgery, with patient-centred questionnaires superseding traditional surgeon-based assessments. The assessment of complications after surgery and their impact on the patient has not enjoyed this same enlightened approach. This study sought to quantify the incidence and bothersomeness of patient-rated complications 1 year after surgery. Patients with lumbar degenerative disorders, operated with the goal of pain relief between October 2006 and September 2010, completed a questionnaire 1 year postoperatively enquiring about complications arising as a consequence of their operation. They rated the bothersomeness of any such complications on a 5-point scale. Global outcome of surgery and satisfaction at the 12-month follow-up were also rated on 5-point Likert scales. The multidimensional Core Outcome Measures Index (COMI) was completed preoperatively and at the 12-month follow-up. Of 2,282 patients completing the questionnaire (92% completion rate), 687 (30.1%) reported complications, most commonly sensory disturbances (36% of those with complications) or ongoing/new pain (26%), followed by motor problems (8%), pain plus neurological disturbances (11%), and problems with wound healing (6%). The corresponding "bothersomeness" ratings for these were: 1% not at all, 23% slightly, 27% moderately, 31% very, and 18% extremely bothersome. The greater the bothersomeness, the worse the global outcome (Rho = 0.51, p < 0.0001), patient satisfaction (Rho = 0.44, p < 0.0001) and change in COMI score (Rho = 0.52, p < 0.0001). Most complications reported by the patient are perceived to be at least moderately bothersome and hence are not inconsequential. Complications and their severity should be assessed from both the patient's and the surgeon's perspectives--not least to better understand the reasons for poor outcome and dissatisfaction with treatment.
    European Spine Journal 04/2012; 21(8):1625-32. · 2.47 Impact Factor
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    ABSTRACT: Clinical symptoms in lumbar degenerative spondylolisthesis (LDS) vary from predominantly radiating pain to severe mechanical low back pain. We examined whether the outcome of surgery for LDS varied depending on the predominant baseline symptom and the treatment administered [decompression with fusion (D&F) or decompression alone (D)]. 213 consecutive patients (69 ± 9 years; 155f, 58 m) participated. Inclusion criteria were LDS, maximum three affected levels, no previous surgery at the affected level, and D (N = 56) or D&F (N = 157) as the operative procedure. Pre-op and at 12 months' follow-up (FU), patients completed the multidimensional Core Outcome Measures Index (COMI) including 0-10 leg-pain (LP) and LBP scales. At 12 months' FU, patients rated global outcome which was then dichotomised into "good" and "poor". Pre-operatively, LBP and COMI scores were significantly worse (p < 0.05) in the D&F group than in the D group. The improvement in COMI at 12 months' FU was significantly greater for D&F than for D (p < 0.001) and was not influenced by the patient's declared "main problem" at baseline (back pain, leg pain, or neurological disturbances) (p > 0.05). There was a higher proportion (p = 0.01) of "good" outcomes at 12 months' FU in D&F (86%) than in D (70%). Multiple regression analysis, controlling for possible confounders, revealed treatment group to be the only significant predictor of outcome (adding fusion = better outcome). Our study indicated that LDS patients showed better patient-based outcome with instrumented fusion and decompression than with decompression alone, regardless of baseline symptoms. This may be due to the fact that the underlying slippage as the cause of the stenosis is better addressed with fusion.
    European Spine Journal 07/2011; 21(2):268-75. · 2.47 Impact Factor
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    ABSTRACT: Decompression surgery is a common and generally successful treatment for lumbar disc herniation (LDH). However, clinical practice raises some concern that the presence of concomitant low back pain (LBP) may have a negative influence on the overall outcome of treatment. This prospective study sought to examine on how the relative severity of LBP influences the outcome of decompression surgery for LDH. The SSE Spine Tango System was used to acquire the data from 308 patients. Inclusion criteria were LDH, first-time surgery, maximum 1 affected level, and decompression as the only procedure. Before and 12 months after surgery, patients completed the multidimensional Core Outcome Measures Index (COMI; includes 0-10 leg/buttock pain (LP) and LBP scales); at 12 months, global outcome was rated on a Likert scale and dichotomised into "good" and "poor" groups. In the "good" outcome group, mean baseline LP was 2.8 (SD 3.1) points higher than LBP; in the "poor" group, the corresponding value was 1.1 (SD 2.9) (p < 0.001 between groups). Significantly fewer patients with back pain as their "main problem" had a good outcome (69% good) when compared with those who reported leg/buttock pain (84% good) as the main problem (p = 0.04). In multivariate regression analyses (controlling for age, gender, co-morbidity), baseline LBP intensity was a significant predictor of the 12-month COMI score, and of the global outcome (each p < 0.05) (higher LBP, worse outcome). In conclusion, patients with more back pain showed significantly worse outcomes after decompression surgery for LDH. This finding fits with general clinical experience, but has rarely been quantified in the many predictor studies conducted to date. Consideration of the severity of concomitant LBP in LDH may assist in establishing realistic patient expectations before the surgery.
    European Spine Journal 07/2011; 20(7):1166-73. · 2.47 Impact Factor
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    ABSTRACT: As the average life expectancy of the population increases, surgical decompression of the lumbar spine is being performed with increasing frequency. It now constitutes the most common type of lumbar spinal surgery in older patients. The present prospective study examined the 5-year outcome of lumbar decompression surgery without fusion. The group comprised 159 patients undergoing decompression for degenerative spinal disorders who had been participants in a randomised controlled trial of post-operative rehabilitation that had shown no between-group differences at 2 years. Leg pain and back pain intensity (0-10 graphic rating scale), self-rated disability (Roland Morris), global outcome of surgery (5-point Likert scale) and re-operation rates were assessed 5 years post-operatively. Ten patients had died before the 5-year follow-up. Of the remaining 149 patients, 143 returned a 5-year follow-up (FU) questionnaire (effective return rate excluding deaths, 96%). Their mean age was 64 (SD 11) years and 92/143 (64%) were men. In the 5-year follow-up period, 34/143 patients (24%) underwent re-operation (17 further decompressions, 17 fusions and 1 intradural drainage/debridement). In patients who were not re-operated, leg pain decreased significantly (p < 0.05) from before surgery to 2 months FU, after which there was no significant change up to 5 years. Low back pain also decreased significantly by 2 months FU, but then showed a slight, but significant (p < 0.05), gradual increase of <1 point by 5-year FU. Disability decreased significantly from pre-operative to 2 months FU and showed a further significant decrease at 5 months FU. Thereafter, it remained stable up to the 5-year FU. Pain and disability scores recorded after 5 years showed a significant correlation with those at earlier follow-ups (r = 0.53-0.82; p < 0.05). Patients who were re-operated at some stage over the 5-year period showed significantly worse final outcomes for leg pain and disability (p < 0.05). In conclusion, pain and disability showed minimal change in the 5-year period after surgery, but the re-operation rate was relatively high. Re-operation resulted in worse final outcomes in terms of leg pain and disability. At the 5-year follow-up, the "average" patient experienced frequent, but relatively low levels of, pain and moderate disability. This knowledge on the long-term outcome should be incorporated into the pre-operative patient information process.
    European Spine Journal 11/2010; 19(11):1883-91. · 2.47 Impact Factor
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    A Luca, A F Mannion, D Grob
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    ABSTRACT: The aim of this study was to evaluate the influence of smoking on the outcome of patients undergoing surgery for degenerative spinal diseases, and to examine whether smoking had a differential impact on outcome, depending on the fusion technique used. The cohort included 120 patients treated with two different fusion techniques (translaminar screw fixation and TLIF). They were categorised with regard to their smoking habits at the time of surgery and completed the Core Outcome Measures Index at baseline and follow-up (FU) (3, 12 and 24 months FU); at FU they also rated the global outcome of surgery. The distribution of smokers was comparable in the two groups. For the TS group, the greater the number of cigarettes smoked, the less the reduction in pain intensity from pre-op to 24 months FU; the relationship was not significant for the TLIF group. The percentage of good global outcomes declined with time in the TS smokers such that by 24 months FU, there was a significant difference between TS smokers and TS-non-smokers. No such difference between smokers and non-smokers was evident in the TLIF group at any FU time. In conclusion, the TS technique was more vulnerable to the effects of smoking than was TLIF: possibly the more extensive stabilisation of the 360° fusion renders the environment less susceptible to the detrimental effects on bony fusion of cigarette smoking.
    European Spine Journal 10/2010; 20(4):629-34. · 2.47 Impact Factor
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    ABSTRACT: An abstract is unavailable. This article is available as HTML full text and PDF.
    Spine Journal Meeting Abstracts. 09/2010;
  • D Grob
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    ABSTRACT: The spinal intervertebral disc can cause neurocompression or pain as a result of degeneration. Surgical interventions, therefore, include decompression, fusion, disc replacement or a combination thereof. Identifying the painful segment in the case of axial pain requires accurate segment diagnosis and may require invasive diagnostic measures (joint infiltration, discography), since imaging is often not fluid enough. In the case of fusion following disc removal, the placeholder is substitued in the form of a cage or autologous iliac crest graft. Alternatively, when dorsal elements are intact, a disc prosthesis can be inserted. In the case of compression, removal of the compromised structures (disc, osteophytes) becomes necessary. If the indication is correctly made and the appropriate surgical technique used, good results can be expected from cervical spine surgery.
    Der Orthopäde 02/2010; 39(3):335-47. · 0.51 Impact Factor
  • D. Grob
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    ABSTRACT: Die zervikale Bandscheibe kann Ursache von Neurokompression oder Schmerzen durch Degeneration sein. Die chirurgischen Interventionen beinhalten Dekompression, Fusion, Bandscheibenersatz oder eine Kombination dieser Verfahren. Die Identifizierung des schmerzhaften Segments bei axialem Schmerz verlangt eine genaue Segmentdiagnostik und kann invasiv-diagnostische Maßnahmen (Gelenkinfiltration, Diskographie) erfordern, da die Bildgebung häufig nicht ausreicht. Bei einer Fusion nach Entfernung der Bandscheibe wird der Platzhalter in Form eines Cage oder autologen Beckenspans eingeführt. Alternativ kann bei intakten dorsalen Elementen eine Bandscheibenprothese eingesetzt werden. Bei vorliegender Neurokompression müssen die komprimierenden Strukturen (Bandscheibe, Osteophyten) entfernt werden. Bei korrekter Indikation und Operationstechnik kann an der Halswirbelsäule mit guten Resultaten gerechnet werden. The spinal intervertebral disc can cause neurocompression or pain as a result of degeneration. Surgical interventions, therefore, include decompression, fusion, disc replacement or a combination thereof. Identifying the painful segment in the case of axial pain requires accurate segment diagnosis and may require invasive diagnostic measures (joint infiltration, discography), since imaging is often not fluid enough. In the case of fusion following disc removal, the placeholder is substitued in the form of a cage or autologous iliac crest graft. Alternatively, when dorsal elements are intact, a disc prosthesis can be inserted. In the case of compression, removal of the compromised structures (disc, osteophytes) becomes necessary. If the indication is correctly made and the appropriate surgical technique used, good results can be expected from cervical spine surgery. SchlüsselwörterZervikale Bandscheibe-Zentrale Fusion-Plattenfixation-Diskusprothese-Dekompression KeywordsSpinal intervertebral disc-Central fusion-Plate fixation-Disc prosthesis-Decompression
    Der Orthopäde 01/2010; 39(3):335-347. · 0.51 Impact Factor
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    ABSTRACT: In a prospective observational study we compared the two-year outcome of lumbar fusion by a simple technique using translaminar screws (n = 57) with a more extensive method using transforaminal lumbar interbody fusion and pedicular screw fixation (n = 63) in consecutive patients with degenerative disease of the lumbar spine. Outcome was assessed using the validated multidimensional Core Outcome Measures Index. Blood loss and operating time were significantly lower in the translaminar screw group (p < 0.01). The complication rates were similar in each group (2% to 4%). In all, 91% of the patients returned their questionnaire at two-years. The groups did not differ in Core Outcome Measures Index score reduction, 3.6 (sd 2.5) (translaminar screws) vs 4.0 (sd 2.8) (transforaminal lumbar interbody fusion) (p = 0.39); 'good' global outcomes, 78% (translaminar screws) vs 78% (transforaminal lumbar interbody fusion) (p = 0.99) or satisfaction with treatment, 82% (translaminar screws) vs 86% (transforaminal lumbar interbody fusion) (p = 0.52). The two fusion techniques differed markedly in their extent and the cost of the implants, but were associated with almost identical patient-orientated outcomes. Extensive three-point stabilisation is not always required to achieve satisfactory patient-orientated results at two years.
    Journal of Bone and Joint Surgery - British Volume 10/2009; 91(10):1347-53. · 2.69 Impact Factor
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    ABSTRACT: The generic approach of the Spine Tango documentation system, which uses web-based technologies, is a necessity for reaching a maximum number of participants. This, in turn, reduces the potential for customising the Tango according to the individual needs of each user. However, a number of possibilities still exist for tailoring the data collection processes to the user's own hospital workflow. One can choose between a purely paper-based set-up (with in-house scanning, data punching or mailing of forms to the data centre at the University of Bern) and completely paper-free online data entry. Many users work in a hybrid mode with online entry of surgical data and paper-based recording of the patients' perspectives using the Core Outcome Measures Index (COMI) questionnaires. Preoperatively, patients can complete their questionnaires in the outpatient clinic at the time of taking the decision about surgery or simply at the time of hospitalisation. Postoperative administration of patient data can involve questionnaire completion in the outpatient clinic, the handing over the forms at the time of discharge for their mailing back to the hospital later, sending out of questionnaires by post with a stamped addressed envelope for their return or, in exceptional circumstances, conducting telephone interviews. Eurospine encourages documentation of patient-based information before the hospitalisation period and surgeon-based information both before and during hospitalisation; both patient and surgeon data should be acquired for at least one follow-up, at a minimum of three to six months after surgery. In addition, all complications that occur after discharge, and their consequences should be recorded.
    European Spine Journal 07/2009; 18 Suppl 3:312-20. · 2.47 Impact Factor
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    ABSTRACT: Studies comparing the relative merits of microdiscectomy and standard discectomy report conflicting results, depending on the outcome measure of interest. Most trials are small, and few have employed validated, multidimensional patient-orientated outcome measures, considered essential in outcomes research. In the present study, data were collected prospectively from six surgeons participating in a surgical registry. Inclusion criteria were: lumbar/lumbosacral degenerative disease; discectomy/sequestrectomy without additional fusion/stabilisation; German or English-speaking. Before and 3 and 12 months after surgery, patients completed the Core Outcome Measures Index comprising questions on leg/buttock pain, back pain, back-related function, symptom-specific well-being, general quality-of-life, and social and work disability. At follow-up, they rated overall satisfaction, global outcome, and perceived complications. Compliance with the registry documentation was excellent: 87% for surgeons (surgery forms), 91% for patients (for 12 months follow-up). 261 patients satisfied the inclusion criteria (225 microdiscectomy, 36 standard discectomy). The standard discectomy group had significantly greater blood-loss than the microdiscectomy (P < 0.05). There were no group differences in the proportion of surgical complications or duration of hospital stay (P > 0.05). The groups did not differ in relation to any of the patient-orientated outcomes or individual outcome domains (P > 0.05). Though not equivalent to an RCT, the study included every single eligible patient in our Spine Center and allowed surgeons to use their regular procedure; it hence had extremely high external validity (relevance/generalisability). There was no clinically relevant difference in outcome after lumbar disc excision dependent on the use of the microscope. The decision to use the microscope should rest with the surgeon.
    European Spine Journal 04/2009; 18 Suppl 3:360-6. · 2.47 Impact Factor
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    ABSTRACT: The Core Outcome Measures Index (COMI) is a short, multidimensional outcome instrument, with excellent psychometric properties, that has been recommended for use in monitoring the outcome of spinal surgery from the patient's perspective. This study examined the feasibility of implementation of COMI and its performance in clinical practice within a large Spine Centre. Beginning in March 2004, all patients undergoing spine surgery in our Spine Centre (1,000-1,200 patients/year) were asked to complete the COMI before and 3, 12 and 24 months after surgery. The COMI has one question each on back (neck) pain intensity, leg/buttock (arm/shoulder) pain intensity, function, symptom-specific well being, general quality of life, work disability and social disability, scored as a 0-10 index. At follow-up, patients also rated the global effectiveness of surgery, and their satisfaction with their treatment in the hospital, on a five-point Likert scale. After some fine-tuning of the method of administration, completion rates for the pre-op COMI improved from 78% in the first year of operation to 92% in subsequent years (non-response was mainly due to emergencies or language or age issues). Effective completion rates at 3, 12 and 24-month follow-up were 94, 92 and 88%, respectively. The 12-month global outcomes (from N = 3,056 patients) were operation helped a lot, 1,417 (46.4%); helped, 860 (28.1%); helped only little, 454 (14.9%); did not help, 272 (8.9%); made things worse, 53 (1.7%). The mean reductions in COMI score for each of these categories were 5.4 (SD2.5); 3.1 (SD2.2); 1.3 (SD1.7); 0.5 (SD2.2) and -0.7 (SD2.2), respectively, yielding respective standardised response mean values ("effect sizes") for each outcome category of 2.2, 1.4, 0.8, 0.2 and 0.3, respectively. The questionnaire was feasible to implement on a prospective basis in routine practice, and was as responsive as many longer spine outcome questionnaires. The shortness of the COMI and its multidimensional nature make it an attractive option to comprehensively assess all patients within a given Spine Centre and hence avoid selection bias in reporting outcomes.
    European Spine Journal 04/2009; 18 Suppl 3:367-73. · 2.47 Impact Factor
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    ABSTRACT: The Core Outcome Measures Index (COMI) is a reliable and valid instrument for assessing multidimensional outcome in spine surgery. The minimal clinically important score-difference (MCID) for improvement (MCID(imp)) was determined in one of the original research studies validating the instrument, but has never been confirmed in routine clinical practice. Further, the MCID for deterioration (MCID(det)) has never been investigated; indeed, this needs very large sample sizes to obtain sufficient cases with worsening. This study examined the MCIDs of the COMI in routine clinical practice. All patients undergoing surgery in our Spine Center since February 2004 were asked to complete the COMI before and 12 months after surgery. The COMI has one question each on back (neck) pain intensity, leg/buttock (arm/shoulder) pain intensity, function, symptom-specific well-being, general quality of life, work disability, and social disability, scored as a 0-10 index. At follow-up, patients also rated the global effectiveness of surgery, on a 5-point Likert scale. This was used as the external criterion ("anchor") in receiver operating characteristics (ROC) analyses to derive cut-off scores for individual improvement and deterioration. Twelve-month follow-up questionnaires were returned by 3,056 (92%) patients. The group mean COMI score change for patients declaring that the "operation helped" was a reduction of 3.1 points; the corresponding value for those whom it "did not help" was a reduction of 0.5 points. The group MCID(imp) was hence 2.6 points reduction; the corresponding group MCID(det) was 1.2 points increase (0.5 minus -0.7). The area under the ROC curve was 0.88 for MCID(imp) and 0.89 for MCID(det) (both P < 0.0001), indicating that the COMI had good discriminative ability. The cut-offs for individual improvement and deterioration, respectively, were > or =2.2 points decrease (sensitivity 81%, specificity 83%) and > or =0.3 points increase (sensitivity 83%, specificity 88%). The MCID(imp) score of 2.2 points was similar to that reported in the original study (2-3 points, depending on external criterion used). The MCID(det) suggested that the COMI is less responsive to deterioration than to improvement, a phenomenon also reported for other spine outcome instruments. This needs further investigation in even larger patient groups. The MCIDs provide essential information for both the planning (sample size) and interpretation of the results (clinical relevance) of future clinical studies using the COMI.
    European Spine Journal 03/2009; 18 Suppl 3:374-9. · 2.47 Impact Factor
  • D Grob
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    ABSTRACT: Total disc replacement has been introduced to avoid the biomechanical changes often caused in adjacent segments by the traditional fusion of two or more vertebrae in the lumbar spine. It also aims to maintain mobility and eliminate pain. Total disc replacement using a flexible prosthesis is currently a popular solution. The main indication for this procedure is low back pain caused by disc degeneration. Diagnostic procedures are important to correctly identify and localize the affected disc. To this end, discography represents the most reliable test; however, imaging and clinical investigations are also important adjuncts. To date, there are insufficient long-term data available on the relatively new total disc replacement technique to be able to confirm its superiority compared to traditional fusion procedures in terms of low back pain and patient satisfaction, but short- and mid-term results indicate that, when correctly indicated, both procedures have similar outcomes.
    Der Orthopäde 01/2009; 38(1):93-9; quiz 100-1. · 0.51 Impact Factor
  • D. Grob
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    ABSTRACT: Zur Vermeidung der durch eine Verblockung zweier oder mehrerer Wirbel entstehenden biomechanischen Veränderungen in den angrenzenden Segmenten wird der Erhalt der Beweglichkeit bei gleichzeitiger Elimination des Schmerzes angestrebt. Der Ersatz der Bandscheibe durch eine bewegliche Prothese ist eine zurzeit populäre Lösung. Das Anwendungsgebiet der Methode umfasst in erster Linie Rückenschmerzen, die auf eine degenerative Veränderung der Bandscheiben zurückzuführen sind. Der Diagnostik zur Identifikation und Lokalisation der betroffenen Bandscheibe kommt dabei eine wichtige Bedeutung zu. An erster Stelle steht dabei die Diskographie, aber auch Bildgebung und klinische Symptomatik werden einbezogen. Bei der verhältnismäßig neuen Technik der Bandscheibenprothese liegen noch zu wenige Langzeitbeobachtungen vor, um eine definitive Beurteilung der Resultate zu ermöglichen. Kurz- und mittelfristige Beobachtungen lassen aber den Schluss zu, dass bei korrekter Indikation die Resultate bezüglich Rückenschmerzen und Patientenzufriedenheit mit denen der Verblockung vergleichbar sind. Total disc replacement has been introduced to avoid the biomechanical changes often caused in adjacent segments by the traditional fusion of two or more vertebrae in the lumbar spine. It also aims to maintain mobility and eliminate pain. Total disc replacement using a flexible prosthesis is currently a popular solution. The main indication for this procedure is low back pain caused by disc degeneration. Diagnostic procedures are important to correctly identify and localize the affected disc. To this end, discography represents the most reliable test; however, imaging and clinical investigations are also important adjuncts. To date, there are insufficient long-term data available on the relatively new total disc replacement technique to be able to confirm its superiority compared to traditional fusion procedures in terms of low back pain and patient satisfaction, but short- and mid-term results indicate that, when correctly indicated, both procedures have similar outcomes.
    Der Orthopäde 12/2008; 38(1):93-102. · 0.51 Impact Factor
  • D. Grob
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    ABSTRACT: The goal pursued by atlantoaxial arthrodesis is the elimination of any motion of the atlas and axis bones with respect to each other. The screw fixation procedure described by Magerl leads to higher stability rates than conventional posterior arthrodesis techniques. The greater stability afforded by C1/C2 screws makes it possible to perform short fusions, e.g. between the occipital bone and C2, whereas with other techniques fixation must be extended up to C4/5 in order to obtain a satisfactory lever arm. In this study, we used transarticular screw fixation in order to stabilize a series of 54 patients suffering from rheumatoid arthritis, who presented with atlantoaxial instability. They were studied retrospectively with a mean follow-up of 6 years (range: 2-13 years). The pain score on examination, as assessed by means of the Visual Analog Scale (0-10), was 2, as compared with a preoperative score of 6. Seventy-nine percent of patients stated that they would subject themselves to the same surgical procedure if they found themselves in the same situation; 16% were not sure as to whether they would or would not and 5% said that they would not. Seventy-eight percent of patients declared themselves highly satisfied with the result obtained; 18% found the result satisfactory and 3% declared themselves dissatisfied with the result obtained. Atlantoaxial arthrodesis is indicated in the event of instability. Clinically, instability can manifest itself as persistent pain or as myelopathy, resulting from repetitive microtrauma to the spinal cord. Conventional fusion techniques, based on the use of wires, are simple to perform but lead to considerable rates of pseudoarthrosis, particularly in patients with rheumatoid arthritis. Transarticular atlantoaxial screw fixation provides higher rates of stability and reduces the rate of pseudoarthrosis. Placement of the screws requires a detailed anatomical study, especially of the C2 pars interarticularis, through CT- or NMRi-scans. The surgical technique is rather challenging, but leads to a low rate of complications.
    Revista Española de Cirugía Ortopédica y Traumatología. 08/2008; 52(4).
  • D. Grob
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    ABSTRACT: El objetivo de la artrodesis entre el atlas y el axis es eliminar el movimiento relativo entre ambos. El atornillado descrito por Magerl muestra una estabilidad superior a las técnicas de artrodesis posterior convencionales. El aumento de la estabilidad proporcionado por los tornillos C1/C2 nos permite efectuar fusiones cortas, por ejemplo entre el occipital y C2, mientras que con otras técnicas es necesario prolongar la fijación hasta C4/5 para conseguir un brazo de palanca suficiente. Hemos estabilizado mediante un atornillado transarticular una serie de 54 pacientes con artritis reumatoide, que presentaban una inestabilidad entre el atlas y el axis. Fueron estudiados de forma retrospectiva, con un seguimiento medio de 6 (2-13) años. El dolor en el momento de la revisión, valorado mediante la escala visual analógica (0-10) fue de 2, en comparación con un valor de 6 en el preoperatorio. El 79% de los pacientes respondió que volvería a repetir el procedimiento quirúrgico si se encontrase en la misma situación, el 16% no se mostró seguro en la respuesta a esta pregunta y el 5% respondió negativamente. El 78% de los pacientes se declaró muy satisfecho con el resultado obtenido; el 18% indicó que el resultado era satisfactorio y el 3% no se mostró contento con el resultado obtenido. La artrodesis entre el atlas y el axis está indicada cuando existe una inestabilidad. Clínicamente, la inestabilidad puede manifestarse como un dolor persistente o como una mielopatía, consecuencia de un microtraumatismo repetitivo sobre la médula. Las técnicas de fusión convencionales, mediante alambres, son sencillas de efectuar pero comportan una considerable tasa de pseudoartrosis, en particular en condiciones desfavorables, como ocurre en la artritis reumatoide. El atornillado transarticular entre el atlas y el axis proporciona una estabilidad superior y disminuye la tasa de pseudoartrosis. La colocación de los tornillos requiere de un minucioso estudio anatómico, en particular de los istmos de C2, mediante cortes de tomografía axial computarizada o resonancia magnética nuclear. La técnica quirúrgica es delicada, pero presenta una baja tasa de complicaciones.
    Aquatic Botany - AQUAT BOT. 01/2008; 52(4):243-249.
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    ABSTRACT: The variables identified as predictors of surgical outcome often differ depending on the specific outcome variable chosen to designate "success". A short set of multidimensional core outcome measures was recently developed, in which each of the following domains was addressed with a single question and then combined in an index: pain, function, symptom-specific well-being, general well-being (quality of life), disability (work and social). The present study examined the factors that predicted surgical outcome as measured using the multidimensional core measures. 163 spinal surgery patients (mixed indications) completed questionnaires before and 6 months after surgery enquiring about demographics, medical/clinical history, fear-avoidance beliefs (FABQ), depression (Zung self-rated depression), and the core measures domains. Multiple regression analyses were used to identify predictor variables for each core domain and for the multidimensional combined core-set index. The combination of baseline symptoms, medical variables (pain duration, previous spine operations, number of levels treated, operative procedure) and psychosocial factors (FABQ and Zung depression) explained 34% of the variance in the core measures index (P < 0.001). With regard to the individual domain items, the medical variables were better in predicting the items "pain" and "symptom-specific well-being" (R (2) = 6-7%) than in predicting "function", "general well-being" or "disability" (each R (2) < 4%). The inverse pattern was shown for the psychosocial predictors, which accounted for in each case approximately 20% variance in "function", "general well-being" and "disability" but only 12-14% variance in "pain" and "symptom-specific well-being". Further to previous studies establishing the sensitivity to change of the core-set, we have shown that a large proportion of the variance in its scores after surgery could be predicted by "well-known" medical and psychosocial predictor variables. This substantiates the recommendation for its further use in registry systems, quality management projects, and clinical trials.
    European Spine Journal 07/2007; 16(6):777-86. · 2.47 Impact Factor
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    ABSTRACT: Degenerative changes of the cervical spine are commonly accompanied by a reduction or loss of the segmental or global lordosis, and are often considered to be a cause of neck pain. Nonetheless, such changes may also remain clinically silent. The aim of this study was to examine the correlation between the presence of neck pain and alterations of the normal cervical lordosis in people aged over 45 years. One hundred and seven volunteers, who were otherwise undergoing treatment for lower extremity problems in our hospital, took part. Sagittal radiographs of the cervical spine were taken and a questionnaire was completed, enquiring about neck pain and disability in the last 12 months. Based on the latter, subjects were divided into a group with neck pain (N = 54) and a group without neck pain (N = 53). The global curvature of the cervical spine (C2-C7) and each segmental angle were measured from the radiographs, using the posterior tangent method, and examined in relation to neck complaints. No significant difference between the two groups could be found in relation to the global curvature, the segmental angles, or the incidence of straight-spine or kyphotic deformity (P > 0.05). Twenty-three per cent of the people with neck pain and 17% of those without neck pain showed a segmental kyphosis deformity of more than 4 degrees in at least one segment--most frequently at C4/5, closely followed by C5/6 and C3/4. The average segmental angle at the kyphotic level was 6.5 degrees in the pain group and 6.3 degrees in the group without pain, with a range of 5-10 degrees in each group. In the group with neck pain, there was no association between any of the clinical characteristics (duration, frequency, intensity of pain; radiating pain; sensory/motor disturbances; disability; healthcare utilisation) and either global cervical curvature or segmental angles. The presence of such structural abnormalities in the patient with neck pain must be considered coincidental, i.e. not necessarily indicative of the cause of pain. This should be given due consideration in the differential diagnosis of patients with neck pain.
    European Spine Journal 06/2007; 16(5):669-78. · 2.47 Impact Factor
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    ABSTRACT: When functional scales are to be used as treatment outcome measures, it is essential to know how responsive they are to clinical change. This information is essential not only for clinical decision-making, but also for the determination of sample size in clinical trials. The present study examined the responsiveness of a German version of the Oswestry Disability Index version 2.1 (ODI) after surgical treatment for low back pain. Before spine surgery 63 patients completed a questionnaire booklet containing the ODI, along with a 0-10 pain visual analogue scale (VAS), the Roland Morris disability questionnaire, and Likert scales for disability, medication intake and pain frequency. Six months after surgery, 57 (90%) patients completed the same questionnaire booklet and also answered Likert-scale questions on the global result of surgery, and on improvements in pain and disability. Both the effect size for the ODI change score 6 months after surgery (0.87) and the area under the receiver operating characteristics (ROC) curve for the relative improvement in ODI score in relation to global outcome 6 months after surgery (0.90) indicated that the ODI showed good responsiveness. The ROC method revealed that a minimum reduction of the baseline (pre-surgery) ODI score by 18% (equal to a mean 8-point reduction in this patient group) represented the cut-off for indicating a "good" individual outcome 6 months after surgery (sensitivity 91.4% and specificity 82.4%). The German version of the ODI is a sensitive instrument for detecting clinical change after spinal surgery. Individual improvements after surgery of at least an 18% reduction on baseline values are associated with a good outcome. This figure can be used as a reliable guide for the determination of sample size in future clinical trials of spinal surgery.
    European Spine Journal 02/2006; 15(1):66-73. · 2.47 Impact Factor

Publication Stats

4k Citations
601.16 Total Impact Points

Institutions

  • 1987–2012
    • Schulthess Klinik, Zürich
      Zürich, Zurich, Switzerland
  • 2005
    • Universität Bern
      • Institute for Evaluative Research in Medicine
      Berna, Bern, Switzerland
  • 1999
    • Universität Ulm
      Ulm, Baden-Württemberg, Germany
  • 1976–1999
    • Maimonides Medical Center
      Brooklyn, New York, United States
  • 1993–1997
    • University of Zurich
      • Institute of Veterinary Anatomy
      Zürich, ZH, Switzerland
  • 1996
    • SUNY Ulster
      Kingston, New York, United States
  • 1995
    • University of Hamburg
      • Department of Internal Medicine II and Clinic (Oncology Center)
      Hamburg, Hamburg, Germany
    • University Medical Center Hamburg - Eppendorf
      Hamburg, Hamburg, Germany
  • 1991–1995
    • Yale University
      • Department of Orthopaedics and Rehabilitation
      New Haven, CT, United States
  • 1990–1993
    • State University of New York
      New York City, New York, United States
  • 1992
    • Osaka City University
      • Department of Orthopaedic Surgery
      Ōsaka, Ōsaka, Japan
  • 1971
    • Gracie Square Hospital, New York, NY
      New York City, New York, United States
  • 1966–1971
    • State University of New York Downstate Medical Center
      • Department of Medicine
      Brooklyn, NY, United States