Joan Bagó

Low Fusion Rate After L5-S1 Laparoscopic Anterior Lumbar Interbody Fusion Using Twin Stand-Alone Carbon Fiber Cages

Study Design. Prospective study of a cohort of patients who underwent L5–S1 laparoscopic anterior lumbar interbody fusion. Objectives. To assess the fusion rate and the clinical outcome more than 2 years after L5–S1 laparoscopic anterior lumbar interbody fusion using twin stand-alone carbon-fiber cages. Summary of Background Data. The first reports on laparoscopic anterior lumbar interbody fusion using stand-alone cages appeared in 1995. Since then several articles have reported contradictory data regarding fusion rate. There are no publications describing the fusion rate of stand-alone lumbar carbon-fiber cages. Methods. The authors evaluated 12 patients (mean age 36.5 years) in whom endoscopic L5–S1 anterior lumbar interbody fusion was performed using twin stand-alone laparoscopic carbon-fiber cages. Clinical evaluation was carried out prospectively by the use of three self-evaluation scales. Radiologic evaluation was performed by an independent radiologist using dynamic flexion–extension films and CT scans at 6 and 12 months after surgery and subsequently every year until fusion was demonstrated. Results. After a mean follow-up of 36.6 months (range 24–63 months) the clinical condition of the patients was significantly better than their preoperative status: visual analog scale (P < 0.01), Prolo score (P < 0.05), and Waddell Disability Index (P < 0.01). L5–S1 mobility did not exceed 5° in any dynamic study. However, the overall CT scan fusion rate at 2 years of follow-up was 16.6%. Three years after surgery, CT demonstrated fusion in one of five patients. Conclusion. Two years after endoscopic L5–S1 anterior lumbar interbody fusion using twin stand-alone laparoscopic carbon-fiber cages, the fusion rate was unacceptably low. However, the clinical outcomes of these patients were significantly improved compared with their preoperative status.

Reliability of retrospective clinical data to evaluate the effectiveness of lumbar fusion in chronic low back pain.

Study Design. Patients in whom a posterior spinal fusion instrumentation had been performed to treat low back pain were asked to recall their preoperative clinical status by retrospectively filling out the same 3 self-evaluation scales they had completed before surgery in a prospective fashion. Objectives. To evaluate the impact of recollection error and compare outcomes using retrospective versus prospective methodologies among a cohort of patients treated with posterior spinal fusion instrumentation. Summary of Background Data. Literature on spine surgery from 1990 to 2000 shows a greater increase in retrospective studies as compared to randomized controlled trials and other prospective studies. Cross-sectional studies evaluate therapeutic effectiveness by comparing the current condition with the recalled (retrospectively recorded) pretreatment condition. There are no studies analyzing the characteristics of recalled data in a cohort of patients with chronic low back pain treated with posterior spinal fusion instrumentation. Methods. The preoperative clinical status of 58 patients, 33 women and 25 men, with a mean age of 48.3 years (22–84 years) was assessed prospectively with 3 self evaluation questionnaires and retrospectively at a mean of 37.5 months (2–58 months) after surgery using the same questionnaires. The Wilcoxon test was used to compare prospective and retrospective preoperative data and to compare prospective outcomes with outcomes determined from cross-sectional data. Agreement between prospective and retrospective measures was estimated with intraclass correlation coefficients for absolute agreement and consistency. Results. Comparisons between prospective and recalled data showed significant differences, demonstrating a worse preoperative situation when using retrospective data. Assessment of treatment effectiveness showed that cross-sectional evaluation significantly improved the real surgical outcome. Both absolute agreement and consistency intraclass correlation coefficients showed poor agreement between prospective and cross-sectional data, revealing no systematic bias. Follow-up, age, and gender did not modify agreement and cross-sectional overestimation. Conclusions. Relying on a patient’s recall of preoperative clinical status is not an accurate method to evaluate surgical outcome after posterior spinal fusion instrumentation. Cross-sectional studies may overestimate the effectiveness of surgery.

Clinical and CT scan evaluation after direct defect repair in spondylolysis using segmental pedicular screw hook fixation.

Direct defect repair using segmental pedicular screw hook fixation was carried out in nine patients with spondylolysis and a mean age of 24.2 years. One patient was fused 3 years after isthmic reconstruction. In the remaining eight patients, after a mean follow-up of 41 months (range, 12-78), three self-evaluation scales revealed a significant (p < 0.05) improvement in clinical status. Computed tomography scans were carried out in seven patients. There was bilateral bony union in two cases, in three pars healing was unilateral, and in two the isthmic defect persisted bilaterally. No correlation was observed between the status of the pars and follow-up. We conclude that repair of defects in spondylolysis may result in a favorable clinical outcome even when anatomic reconstruction of pars interarticularis is not successful.

Transcranial Doppler Monitoring During Laparoscopic Anterior Lumbar Interbody Fusion

We studied the consequences on cerebral hemodynamics of lengthy laparoscopic procedures requiring pneumoperitoneum and head-down positioning. From October 1995 to April 1999, 17 ASA status I or II patients (16 women and 1 man; mean age, 38 yr) were treated with laparoscopic anterior lumbar fusion. Besides standard perioperative monitoring for laparoscopic surgery, the mean blood-flow velocity of both middle cerebral arteries and the pulsatility index were determined by transcranial Doppler ultrasound. Adequate acoustic windows were encountered in 11 of the 17 patients, and the remaining 6 were excluded from the analysis. Paco2 and end-tidal CO2 were maintained within normal limits (<40 mm Hg); ventilation was optimized in all cases. There was a significant increase (P < 0.05) in heart rate and central venous pressure with the change from supine to head-down position in all patients. Transcranial Doppler results for mean middle cerebral artery blood-flow velocity and pulsatility index showed no significant variations at any of the four time points studied during the procedure. There were no technique-related complications, except for moderate postoperative headache in eight patients that resolved with rest and oxygen therapy. We conclude that lengthy laparoscopic procedures in the head-down position performed in otherwise healthy patients do not significantly affect intracranial circulation.

How do idiopathic scoliosis patients who improve after surgery differ from those who do not exceed a minimum detectable change

IntroductionThe minimum detectable change (MDC) of the SRS-22 subtotal score is 6.8 points. With the use of this value, patients who have undergone surgery for idiopathic scoliosis can be dichotomized into two groups: the successful (S) group (those who have reached or exceeded this limit) and the unsuccessful (Un-S) group (those in whom the change was smaller). The aim of this study was to analyze the clinical and radiological differences between these patient groups, as well as those related to the surgical technique.Material and MethodsThe study included 91 patients (77 women and 14 men, mean age 18.1 years). All patients completed the SRS-22 questionnaire preoperatively and at follow-up (mean 45.6 months). In addition, radiological and surgical data were collected: levels instrumented, number of fused vertebrae, and use of thoracoplasty.ResultsBased on the MDC of the SRS-22 subtotal score, patients were assigned to the Un-S group (44 cases, 48.4%) or S group (47 cases). Groups were similar in age, sex, number of fused vertebrae, percentage of patients who underwent thoracoplasty, and the upper and lower instrumented levels. The magnitude of the major curve and percentage of correction after surgery were also similar (Un-S group 62.3º, 53.2%; S group 64.3º, 49.9%). As compared to Un-S group, S patients had a poorer preop score in all the SRS-22 domains, and a clinically significant postop improvement in pain, perceived body image, mental health, and subtotal score. In contrast, the Un-S group showed a worsening of pain, function, mental health, and subtotal score, and a clinically nonsignificant improvement in perceived body image on the follow-up questionnaire. There were no significant differences in the satisfaction domain score between groups (4.36 vs. 4.62). On ROC curve analysis, a preop subtotal score of 74 points predicted allocation to the S or Un-S group at follow-up with 79% sensitivity and 76% specificity.ConclusionThe preop subtotal score of the SRS-22 is a good predictor of the clinical response to surgery.

Cardiac tamponade associated with a peripheral vein central venous catheter

We present a case of cardiac tamponade associated with placement of a central venous catheter (CVC) via a peripheral vein in a 14‐year‐old girl with idiopathic scoliosis undergoing corrective surgery. A number of complications have been described in association with CVC misplacement. Sporadic cases of cardiac tamponade from this have been reported, but the actual incidence is unknown. Death from cardiac tamponade attributed to CVCs ranges from 65 to 100%. In our patient, cannulation of the pericardiophrenic vein was probably the cause of cardiac tamponade, based on radiological evidence that the initial location of the catheter was near the right atrium and possibly at the outlet of the pericardiophrenic vein. The catheter could have advanced into the vein and then to the pericardial sac with postural changes. The acute clinical course of cardiac tamponade in our patient had potentially lethal hemodynamic repercussions. The main diagnostic test for this condition is echocardiography and the only effective treatment is drainage of the pericardial effusion. Echocardiography should be performed before pericardiocentesis except in life‐threatening situations or high clinical suspicion. Although they are rare, it is important to be aware of the potential for CVC complications.

Correlation analysis between digital photography measurement of trunk deformity and self-image perception in patients with idiopathic scoliosis

Trunk deformity in idiopathic scoliosis has been fully analyzed using different surface metrics but all of them are expensive and cannot be widely used. Recently it has been suggested that some measures of trunk deformity obtained in digital photography can be useful in the assessment of trunk deformity. Some asymmetry measures have been proposed but the relationship between these measures and patients’ self-image perception has not been established.

Validity of a quantitative tool of trunk asymmetry based on digital photographs in patients with idiopathic scoliosis

Methods Front and back digital photographs of patients with idiopathic scoliosis (Cobb>25o) were obtained. Shoulder, armpit and waist angles, in addition to trunk asymmetry indexes, were calculated on front and back photographs with Surgimap software. On AP radiographs Coronal Cobb angles and radiological shoulder imbalance using CRIA angle (Angle between horizontal line and a line drawn between, the right and left intersection points of clavicle and rib cage) were calculated. Intra-class correlation coefficient was used to assess intra and inter-rater reliability. The Pearson correlation coefficients (r) were used to estimate concurrent validity between both methods. Results 80 patients (68 females) mean age 20.3 years (12-40 years) were included. Mean Cobb Maximum (CobbMax) was 45.9o (25.1o-77.2o).All measures had a good to excellent intra and inter-rater reliability both in front and back photographs. Waist height angle and CobbMax angle, both in front and back photographs, were significantly correlated (r=0.42 back/r=0.29 front view). There was no significant correlation between proximal thoracic curve magnitude and any of the shoulder measures. The correlation between shoulder and armpit height angles and radiographic clavicle tilt were -0.44 and -0.41 respectively on frontal view. There was a correlation between trapezium angle ratio and clavicle tilt in both views (r=0.43 back/r=0.32 front view). No other statistically significant correlations between both methods were found.

Degree of suitability of information (DSI) for children with idiopathic scoliosis and their parents

Background As parents and their children increasingly use Internet website to obtain information about Adolescent Idiopathic Scoliosis (AIS), a growing need to evaluate the content quality of websites is emerging. Bettany-Saltikov et al. and MacCulloch et al. have suggested some suitable requirements that websites on scoliosis should include. From these suggestions, we have created an instrument to quantify this suitability.

Yet another reason for improving approval and surveillance processes for health technologies

As Caragee et al. [1] recently demonstrated, exposure to recombinant human bone morphogenetic protein-2 during anterior spinal fusion surgery is associated with a higher risk of retrograde ejaculation and infertility amongmale patients. Safety concerns on this product were raised in 2002 [2,3], but the reporting of industry-sponsored studies was engineered to camouflage this fact, and authors linked to the manufacturer dismissed these concerns [4,5]. As a result, physicians and patients were never warned about this complication. Carragee et al., and the authors of two related editorial commentaries in The Spine Journal, should be publicly recognized for their work, courage, and honesty [1–3]. In the past, many diagnostic and therapeutic technologies have been marketed beyond their actual clinical value, used widely for off-label indications, and implemented in routine practice despite undisclosed or serious safety concerns. Within the spine field, this has occurred with drugs, biologics, surgical procedures, and devices [6]. Independent groups of researchers and institutions have published recommendations to prevent such situations [6–10]. They advocate for a more rigorous assessment of health technologies before approval, strict comprehensive postmarketing surveillance, and improvements in transparency of financial arrangements, publication policies, research design, and data management [6–10]. Implementing these recommendations would benefit all honest stakeholders in spine caredand across medicine. The recommendations would defend the best interests of patients, providers, and payers. They would allow patients to make fully informed choices. They would permit physicians and payers to distinguish effective from ineffective technologies. They would protect health-care practitioners from malpractice litigation, by preventing patients from exposure to unnecessary harm. They would reduce the risk of politicians and policymakers rationing truly effective, cost-effective, and safe procedures. They would also benefit the industry by helping to restore lost credibility, establishing a clear research framework, and allowing more rapid dissemination of proven technologies. The example of retrograde ejaculation after exposure to recombinant human bone morphogenetic protein-2 illustrates yet again that until such recommendations are implemented in practice, unnecessary harm to patients will continue, as will spiraling health-care costs, while resources