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David A Wong
The Journal of Bone and Joint Surgery 02/2011; 93(3):e10. · 3.27 Impact Factor
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ABSTRACT: A prospective comparison of quantitative motion analyzed (QMA) flexion/extension radiographs versus computed tomography (CT) as an analytical predictor of cervical pseudarthrosis. Intraoperative confirmation of the fusion was performed.
To prospectively compare motion analyzed flexion/extension radiographs to CT to predict pseudarthroses. Define motion thresholds on flexion/extension radiographs to define pseudarthroses.
Assessment of postoperative fusion success is an important factor in assessing success after anterior cervical spine fusion. Gross intervertebral motion can be used as a measure; however, the current "gold standard" for determining fusion status is a CT to assess bridging bone. Defining the amount of intervertebral motion at the fusion site has been previously addressed and definitions have varied widely.
Data were analyzed at 47 fusion segments. Intervertebral motion at the fusion site was measured from flexion/extension radiographs taken at least 1 year after the cervical spine fusion. Motion was quantified from digitized radiographs by an independent researcher using proprietary quantitative motion analysis (QMA) software. CT scans on all patients were analyzed for fusion status by a neuroradiologist. Those patients determined to have a symptomatic pseudarthrosis were revised and intraoperative motion at the facet joints was documented. Correlation between intraoperative findings, CT and QMA was performed.
Using greater than 4° of measured motion on flexion/extension radiographs resulted in a Spearman correlation P-value of 0.096 (95% confidence interval: -0.06 to 0.66). Using greater than 1° of motion, the Spearman correlation P < 0.0001 (95% CI: 0.54-0.90). The positive predictive value (PPV) using 4° of motion as the criterion was 100%, indicating a high specificity. The negative predictive value (NPV) was 52%, indicating a low sensitivity. Using greater than 1° of motion, the PPV was 100% and the NPV was 73%. Findings from CT showed an identical PPV and NPV to assessments made using greater than 1° of rotation. Specificity and positive predictive value were 100% for all criteria. Using a lack of bridging on CT or more than 1° of intervertebral motion during flexion/extension increased the sensitivity to 85% and the negative predictive value to 85%.
A threshold level of 4° of motion is commonly used to identify a pseudarthrosis. Our prospective study suggests that this value has a high PPV, but a low specificity and would miss many of the pseudarthroses that have angular motion less than 4° (sensitivity 23%). By lowering the threshold for angular motion to 1°, the sensitivity improves to 77%. CT scan has been touted as the gold standard, and it has a high positive predictive value of 100%. However, its NPV was slightly lower than using 1° of motion on QMA analyzed flexion-extension films (73% vs. 79%). In conclusion, although CT scan has long been regarded as the gold standard for determining a pseudarthrosis in the cervical spine, the interpretation is subjective and vulnerable to both type I and type II errors. Analysis of motion using Quantitative Motion Analysis is seemingly less subjective than CT and in our prospective study was more predictive of an operatively confirmed pseudarthrosis.
Spine 12/2010; 36(6):463-8. · 2.08 Impact Factor
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The Journal of Bone and Joint Surgery 05/2010; 92(5):1305-11. · 3.27 Impact Factor
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The Journal of Bone and Joint Surgery 07/2009; 91(6):1534-41. · 3.27 Impact Factor
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ABSTRACT: There has been widespread interest in medical errors since the publication of To Err Is Human: Building a Safer Health System by the Institute of Medicine in 2000. The Patient Safety Committee of the American Academy of Orthopaedic Surgeons has compiled the results of a member survey to identify trends in orthopaedic errors that would help to direct quality assurance efforts.
Surveys were sent to 5540 Academy fellows, and 917 were returned (a response rate of 16.6%), with 53% (483) reporting an observed medical error in the previous six months.
A general classification of errors showed equipment (29%) and communication (24.7%) errors with the highest frequency. Medication errors (9.7%) and wrong-site surgery (5.6%) represented serious potential patient harm. Two deaths were reported, and both involved narcotic administration errors. By location, 78% of errors occurred in the hospital (54% in the surgery suite and 10% in the patient room or floor). The reporting orthopaedic surgeon was involved in 60% of the errors; a nurse, in 37%; another orthopaedic surgeon, in 19%; other physicians, in 16%; and house staff, in 13%. Wrong-site surgeries involved the wrong side (59%); another wrong site, e.g., the wrong digit on the correct side (23%); the wrong procedure (14%); or the wrong patient (5% of the time). The most frequent anatomic locations were the knee and the fingers and/or hand (35% for each), the foot and/or ankle (15%), followed by the distal end of the femur (10%) and the spine (5%).
Medical errors continue to occur and therefore represent a threat to patient safety. Quality assurance efforts and more refined research can be addressed toward areas with higher error occurrence (equipment and communication) and high risk (medication and wrong-site surgery).
The Journal of Bone and Joint Surgery 04/2009; 91(3):547-57. · 3.27 Impact Factor
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ABSTRACT: Bone morphogenetic protein-2 (BMP-2) (Infuse) has been approved for use in anterior lumbar fusion in conjunction with an LT cage. However, off-label use is seen with anterior cervical fusion, posterior lumbar interbody fusion (PLIF), and transforaminal lumbar interbody fusion (TLIF). The Federal Food and Drug Administration trial of BMP-2 in a PLIF application was halted because of a high incidence of ectopic bone forming in the neural canal (75%). The authors did not find a correlation between ectopic bone and increased leg pain. They concluded that the ectopic bone was a radiographic phenomenon and not associated with clinical findings. Complications using BMP in the cervical spine have been reported. Heretofore, there has not been a similar warning voiced for use of BMP in a lumbar PLIF or TLIF.
The purpose was to report five cases of ectopic bone in the canal associated with PLIF/TLIF off-label use of BMP-2 potentially contributing to abnormal neurologic findings.
This is an observational cohort study of patients referred to a tertiary care private medical center.
This was a retrospective chart review of patients referred to a tertiary spine institute with complications after surgery where BMP-2 had been used in an off-label PLIF or TLIF application. Patient demographics, operating room (OR) notes from the index BMP surgery, imaging studies, and current clinical status were reviewed.
Five cases of ectopic bone in the spinal canal with potential neurologic compromise were identified.
It does appear that ectopic bone in the spinal canal associated with BMP-2 use in PLIF or TLIF may contribute to symptomatic neurologic findings in rare cases. Revision surgeries are difficult. This article challenges a previous publication, which concluded that the high incidence of ectopic bone was of no clinical significance. Isolating BMP anteriorly in the disc space using layered barriers of bone graft between the BMP and the annular defect may reduce the incidence of ectopic bone in the spinal canal. Surgeons need to weigh the benefits versus risks of any technology used off label when making treatment decisions with their patients.
The Spine Journal 12/2007; 8(6):1011-8. · 3.29 Impact Factor
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ABSTRACT: A review of issues linking advocacy, patient safety, and quality.
To heighten awareness of patient safety issues that require ongoing advocacy efforts by physicians treating spinal disorders.
The 1999 Institute of Medicine report "To Err is Human. Building a Safer Health System" was a landmark publication that vaulted patient safety into the limelight of public awareness and media attention. The American Academy of Orthopedic Surgeons had addressed the wrong site surgery issue with its Sign Your Site Program even before the Institute of Medicine report. Several professional medical societies involved in spine care have made advocating for patient safety a priority.
A summary of areas of advocacy efforts involving patient safety and quality. These include the Sign Your Site Program from the American Academy of Orthopedic Surgeons, Sign, Mark and X-ray from the North American Spine Society, Joint Commission on the Accreditation of Healthcare Organizations Universal Protocol, and technology assessment. Advocacy on the Federal, state, and local levels concerning patient safety is reviewed.
Awareness of patient safety issues has increased. Several patient safety protocols (Sign Your Site, Sign, Mark and X-ray, and the Universal Protocol) are in place. There is increased monitoring of medical errors on the state and local, especially hospital, levels.
Patient safety is an absolute provision of health care. Physicians need to set a personal example for compliance with existing patient safety systems such as the Universal Protocol and be active advocates for patient safety.
Spine 06/2007; 32(11 Suppl):S2-8. · 2.08 Impact Factor
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David A Wong
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ABSTRACT: In every spinal procedure, identifying the specific patient, proper surgical site, and pathologic lesion for surgical intervention are crucial patient safety concerns. The 1999 Institute of Medicine report "To Err is Human" identified adverse events associated with surgery. Both the American Academy of Orthopaedic Surgeons and the North American Spine Society have had voluntary, systems-based programs in place for several years to address wrong patient, wrong procedure, and wrong site surgery. Beginning July 1, 2004, the Joint Commission on the Accreditation of Healthcare Organizations mandated that hospitals comply with the JCAHO Universal Protocol. In addition to surgical site marking, the protocol incorporates additional factors, such as calling a time out before skin incision to do a final systems check of patient identification, surgical site, records, imaging studies, equipment, and review of preoperative medication.
The Journal of the American Academy of Orthopaedic Surgeons 05/2006; 14(4):226-32. · 2.66 Impact Factor
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American journal of orthopedics (Belle Mead, N.J.) 07/2003; 32(6):274; author reply 274-5.
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ABSTRACT: The role of total disc arthroplasty (TDA) in the treatment of spinal pathology is unclear. TDA has been touted as an alternative to fusion. However, not all back pain is purely discogenic in origin. Contraindications to TDA exist. At Spine Week in Porto, Portugal, Cammisa's group from the Hospital for Special Surgery in New York presented a series of 56 fusions where 100% of patients had one or more of 10 contraindications to TDA. En face, this appears to be an extremely large number.
The purpose of the study was to repeat the Hospital for Special Surgery study in another cohort of fusion patients.
This study was an independent, retrospective record review of 100 consecutive lumbar spinal fusions performed at a tertiary care private medical center.
All adult patients having primary1-3 level lumbar spinal fusions from January 2003 to May 2004 were assessed.
Physiologic measures included imaging, range of motion, and response to facet blocks.
A retrospective chart review was performed of 100 consecutive patients having primary 1-3 level lumbar fusion by all five active staff spinal surgeons (3 orthopedic and 2 neurosurgeons). The review was performed independently by the doctorate level physiotherapist who serves as the medical center's research coordinator, reporting to the chairman of the Hospital institutional review board. The same 10 contraindications from Cammisa's study were noted. Additional facet arthrosis data were collected, including mention on imaging reports or operating room notes. Clinical notes were reviewed for documentation of range of lumbar motion (ROM) and whether there was restricted or painful extension ROM. Note was made if patients had facet blocks as another clinical indicator of facet arthrosis.
All 100 patients had at least one contraindication to TDA. The average was 3.69 (range 1-7). Only one patient had facet arthrosis as their only contraindication. Facet arthrosis was documented on imaging reports or operating room notes in 97/100. Reduced extension was present in 71/75 charts that documented ROM. Facet blocks were performed in 12/100 and gave greater than 50% relief in nine.
Both our study and Cammisa's indicate that all lumbar fusion patients in our two institutions have at least one contraindication to TDA. The average fusion patient does not appear to have isolated discogenic pain. A large proportion of the patients appeared to have facet arthritis. The point where facet arthrosis definitely constitutes a contradiction to TDA will require analysis during long-term arthroplasty follow-up studies. Suitable patients for TDA may not represent a significant cohort presently undergoing lumbar fusion.
The Spine Journal 7(1):5-11. · 3.29 Impact Factor
