Nicholas Ahn

MECHANICAL NECK PAIN ANDCERVICOGENIC HEADACHE

MECHANICAL NECK PAIN is a very common symptom that may occur with cervical spondylosis. It can be associated with cervical radiculopathy and myelopathy or can occur in isolation. Neck pain can result from a variety of causes, including trauma, tumor, infection, and degeneration. The presentation of axial neck pain varies. This article highlights the presentation, differential diagnosis, and appropriate work-up for the patient who presents with mechanical neck pain.

Reherniation and Failure After Lumbar Discectomy: A Comparison of Fragment Excision Alone Versus Subtotal Discectomy

Study Design Retrospective review of 259 lumbar discectomies. Objective To compare rates of reoperation after subtotal discectomy versus established rates after fragment excision. Summary of Background Data Herniated nucleus pulposes (HNP) and annular morphology influence rates of reherniation after discectomy. Certain patterns are linked to reherniation rates exceeding 20%. Methods We retrospectively reviewed 259 single-level lumbar discectomies performed between 1980 and 2005. Mean follow-up was 60.9 months. In each case, annulotomy and subtotal discectomy was performed in addition to excision of disc fragments. HNP morphology was classified according to the 4-part system of Carragee (type 1: fragment/fissure; type 2: fragment/defect; type 3: fragment/contained; type 4: no fragment/contained). Fisher exact test was used to compare our proportion of patients with reherniation and/or reoperation to Caragees series in which only fragment excision was performed. Results Of 259 cases, 12 (4.5%) reoperations were performed. A significant difference in failure/reoperation rate was noted in type 2 herniations. There was a significantly lower rate of failure and reoperation for type 2 HNP after subtotal discectomy (3.4%) when compared with fragment excision alone (21.2%), P<0.003. Conclusions Subtotal discectomy is an acceptable technique that decreases reherniation after lumbar discectomy.

Can Internet Information on Vertebroplasty be a Reliable Means of Patient Self-education?

BackgroundStudies of the quality and accuracy of health and medical information available on the Internet have shown that many sources provide inadequate information. However, to our knowledge, there are no published studies analyzing the quality of information available online regarding vertebroplasty. Because this has been a high-volume procedure with highly debated efficacy, it is critical that patients receive complete, accurate, and well-balanced information before deciding a treatment course. Additionally, few studies have evaluated the merit of academic site authorship or site certification on information quality, but some studies have used measurements of quality that are based primarily on subjective criteria or information accuracy rather than information completeness.Questions/purposesThe purposes of our study were (1) to evaluate and analyze the information on vertebroplasty available to the general public through the Internet; (2) to see if sites sponsored by academic institutions offered a higher quality of information; and (3) to determine whether quality of information varied according to site approval by a certification body.MethodsThree search engines were used to identify 105 web sites (35 per engine) offering information regarding vertebroplasty. Sites were evaluated for authorship/sponsorship, content, and references cited. Information quality was rated as “excellent,” “high,” “moderate,” “low,” or “unacceptable.” Sites also were evaluated for contact information to set up an appointment. Data were analyzed as a complete set, then compared between authorship types, and finally evaluated by certification status. Academic sites were compared with other authorship groups and certified sites were compared with noncertified sites using Student’s t-test.ResultsAppropriate indications were referenced in 74% of sites, whereas only 45% discussed a contraindication to the procedure. Benefits were expressed by 100% of sites, but risks were outlined in only 53% (pxa0<xa00.001). Ninety-nine percent of sites provided step-by-step descriptions of the procedure, and 44% of sites also included images. Alternative treatments were mentioned by 51% of sites. Twenty-seven percent of sites referenced peer-reviewed literature, 41% offered experiential or noncited data based on American populations, and 7% offered analogous data from international populations. Thirty percent of sites provided contact information for patient appointment scheduling. Seven percent of sites were classified as excellent quality, 6% as high quality, 11% as moderate quality, 19% as poor quality, and 57% as unacceptable. Sixteen percent of sites were sponsored by academic institutions, 62% by private groups, 8% by biomedical device companies, and 14% were sponsored otherwise. Academic sites reported fewer risks of the procedure than private sites or other sites (pxa0=xa00.05 and pxa0=xa00.04), but reported more risks than industry sites (pxa0=xa00.007). Academic sites were more likely than sites classified as other to offer contact information for patient appointment scheduling (pxa0=xa00.004). Nine percent of sites evaluated were Health on the Net Foundation (HONCode) certified. No association with improved information quality was observed in these sites relative to noncertified sites (all pxa0>xa00.05).ConclusionsInternet information regarding vertebroplasty is not only inadequate for proper patient education, but also potentially misleading as sites are more likely to present benefits of the procedure than risks. Although academic sites might be expected to offer higher-quality information than private, industry, or other sites, our data would suggest that they do not. HONCode certification cannot be used reliably as a means of qualifying website information quality. Academic sites should be expected to set a high standard and alter their Internet presence with adequate information distribution. Certification bodies also should alter their standards to necessitate provision of complete information in addition to emphasizing accurate information. Treating physicians may want to counsel their patients regarding the limitations of information present on the Internet and the pitfalls of current certification systems.Level of EvidenceLevel IV, economic and decision analyses. See the Instructions for Authors for a complete description of levels of evidence.

Protrusio acetabuli in Marfan syndrome: Age-related prevalence and associated hip function

BACKGROUNDnProtrusio acetabuli is known to occur in patients with Marfan syndrome, but its prevalence, its effects on hip function, and its possible association with the subsequent development of degenerative hip disease have not been studied in a large population. Nevertheless, some clinicians have recommended prophylactic hip surgery for preadolescents with Marfan syndrome and protrusio acetabuli.nnnMETHODSnWe performed a cross-sectional study of 173 patients (346 hips) with Marfan syndrome who were interviewed and examined for calculation of the Iowa hip score. Anteroposterior radiographs of the pelvis were made, and two radiographic indices of acetabular depth were measured: (1) the center-edge angle of Wiberg and (2) the acetabular-ilioischial distance. The presence of protrusio was defined with use of two extant definitions: (1) a center-edge angle of >50 degrees or (2) an acetabular-ilioischial distance of >/=3 mm in male patients or >/=6 mm in female patients. Linear regression analyses were performed between these radiographic indices of acetabular depth and patient age, Iowa hip scores, the magnitude of the radiographic joint space, and range of motion.nnnRESULTSnThe prevalence of protrusio acetabuli was 27% according to the center-edge angle criterion and 16% according to the acetabular-ilioischial distance criterion. The prevalence of protrusio increased until the age of twenty years and remained stable after the age of twenty years. Slight but significant negative correlations were detected between the two radiographic indices of acetabular depth and both the Iowa hip score and the summed range of motion (p < 0.02 for all). No significant relationship was found between the two radiographic indices and pain scores. In patients with Marfan syndrome who were more than forty years old, the Iowa hip scores for hips with protrusio were not significantly lower than those for hips without protrusio.nnnCONCLUSIONSnIn patients with Marfan syndrome, the prevalence of protrusio acetabuli increases during the first two decades of life and then plateaus in terms of both population-wide prevalence and radiographic severity. In this population, protrusio generally is not associated with severely problematic hip function but it is associated with slightly decreased range of motion of the hip. We concluded that prophylactic surgical intervention is not indicated for most patients with Marfan syndrome who have a radiographic diagnosis of protrusio.

Cement augmentation of refractory osteoporotic vertebral compression fractures: survivorship analysis.

Study Design. Retrospective cohort. Objective. To compare survivorship after cement augmentation of refractory osteoporotic vertebral compression fractures (OVCFs) with traditional inpatient pain management and bracing. Summary of Background Data. OVCFs can cause debilitating pain and functional decline necessitating prolonged bed rest and high-dose narcotics. Vertebroplasty and kyphoplasty are cement augmentation procedures used to control pain and restore function in patients with OVCFs that are refractory to conservative treatment. Early mobilization is associated with improved survival after other fractures in elderly patients. Methods. A university hospital database was used to identify all participants treated with primary diagnosis of OVCF between 1993 and 2006. Chart review and imaging studies were used to confirm demographics, comorbidities, diagnosis, and treatment. Survival time was determined using hospital data, national death indices and patient follow-up. Exact Fisher tests, Mann-Whitney tests, and proportional hazards regression models with Kaplan-Meier plots compared patients treated with cement augmentation with controls treated with inpatient pain management and bracing. Patients with high-energy trauma, tumors or age more than 60 years were excluded. Results. Within the past 12 years, 46 patients treated with cement augmentation and 129 matched controls met inclusion criteria. They did not differ with respect to age, sex, and comorbidities. A significant survival advantage was found after cement augmentation compared with controls (P < 0.001; log rank), regardless of comorbidities, age, or the number of fractures diagnosed at the start date (P = 0.565). Controlling simultaneously for covariates, the estimated hazard ratio associated with cementation was 0.10 (95% confidence interval [CI] = 0.02–0.43; P = 0.002) for year 1, 0.15 (95% CI = 0.02–1.12; P = 0.064) for year 2, and 0.95 (95% CI = 0.32–2.79; P = 0.919) for subsequent follow-up. The number of OVCFs at the start time of treatment did not affect survival benefit of cementation (P = 0.44). Conclusion. Cement augmentation of refractory OVCF improves survival for up to 2 years when compared with conservative pain management with bed rest, narcotics, and extension bracing, regardless of age, sex, and number of fractures or comorbidities. Therefore, aggressive management should be considered for refractory OVCFs with intractable back pain.

Are the Left and Right Proximal Femurs Symmetric

BackgroundThe contralateral femur frequently is used for preoperative templating for THA or hemiarthroplasty when the proximal femur is deformed by degenerative changes or fracture. Although femoral symmetry is assumed in these situations, it is unclear to what degree the contralateral femur is symmetrical.Questions/purposeWe therefore defined the degree of asymmetry between left and right proximal femurs and determined whether it was affected by demographics and proximal femoral anatomy.MethodsWe obtained 160 paired femurs from individuals (20–40 years old), evenly distributed for gender and ethnicity (African-American and Caucasian). The height and weight of the individuals were recorded. We measured the femoral head diameter, minimal femoral neck diameter in the AP and cephalocaudal (CC) planes, and the AP femoral diaphyseal diameter. The absolute and percent differences were determined.ResultsAll femoral measurements showed an absolute difference less than 2 mm and a percent asymmetry and difference less than 2% for the femoral head, less than 4% for the femoral neck, and less than 3.5% for the femoral shaft. We found no correlation or predictive value between absolute differences and asymmetry and age, ethnicity, gender, or weight. Height was negatively associated with femoral head differences and thus increased symmetry of the femoral head.ConclusionsOur data support assumptions of substantial symmetry of the proximal femur and highlights that asymmetry is not affected by demographics or the size of the proximal femur. Asymmetry tends not to occur in isolated segments of the femur.

Ten-year clinical and imaging follow-up of dural ectasia in adults with Marfan syndrome.

BACKGROUND CONTEXTnDural ectasia in the lumbosacral spine is a common feature of Marfan syndrome and is associated with low back pain and surgical complications, but its natural history is unknown.nnnPURPOSEnTo evaluate the natural history of dural ectasia in adults with Marfan syndrome by determining if, over time, symptoms associated with dural ectasia worsen, dural ectasia imaging findings worsen, or spondylolisthesis/spondylolysis develops or worsens.nnnSTUDY DESIGNnProspective cohort study.nnnPATIENT SAMPLEnFor our prospective follow-up study, we enrolled 20 patients with Marfan syndrome and dural ectasia who, from 1998 through 1999, had undergone magnetic resonance imaging (MRI) and computed tomography (CT) of the lumbosacral spine and had completed the Oswestry Disability Index (ODI) questionnaire. Of the 20, five did not meet the inclusion criterion of a completed 2009 ODI questionnaire and were excluded. The remaining 15 patients (mean age, 49.6 years; mean follow-up, 10.5 years) formed our study group.nnnOUTCOME MEASURESnThe ODI, MRI-based qualitative and quantitative measurements, CT-based quantitative measurements.nnnMETHODSnWe performed matched-pair analyses via Student t test and Wilcoxon signed-rank test of the ODI scores (15 pairs), dural volume of L5-S2 (eight pairs), dural sac ratio (DSR) of L4-S2 (nine pairs), development/progression of spondolysthesis/spondylolysis (11 pairs), and Fattori qualitative grading of dural ectasia size (10 pairs). Significance was set at p<.05.nnnRESULTSnWe found no statistical differences in the 1998/1999 and 2009 ODI scores (25.8 vs. 22.2 points), dural volume (70.4 vs. 73.9 cm(3)), or DSR (0.68, 0.78, 2.04, and 58.1 vs. 0.69, 0.83, 2.30, and 70.20). There was also no development or progression of spondylolisthesis/spondylolysis and no increase in dural ectasia size.nnnCONCLUSIONSnDuring this 10-year period, the natural history of dural ectasia in adults with Marfan syndrome was not associated with a significant increase in ODI scores, dural ectasia size, or with the development/progression of spondylolisthesis or spondylolysis.

Establishment of parameters for congenital stenosis of the cervical spine: an anatomic descriptive analysis of 1066 cadaveric specimens

PurposeCongenital cervical stenosis (CCS) occurs when the bony anatomy of the cervical canal is smaller than expected in the general population predisposing an individual to symptomatic neural compression. No studies have defined CCS based on the normal population. The diagnosis is currently made based on clinical impression from radiographic studies. The aim of this study is to establish parameters that are associated with CCS, based on anatomic measurements on a large sample of skeletal specimens.MethodsFrom the Hamann-Todd collection at the Cleveland Museum of Natural History, 1,066 skeletal specimens were selected. Digital calipers were used to measure the sagittal canal diameter (SCD), interpedicular distance (IPD), and pedicle length. Canal area at each level was calculated using a geometric formula. A standard distribution was created and values that were 2 SD below mean were considered as congenitally stenotic. An analysis of deviance was performed to identify parameters that were associated with CCS. Regression analysis was used to determine odds ratios (OR) for CCS using these parameters.ResultsCCS was defined at each level as: C3/4xa0=xa01.82xa0cm2, C4/5xa0=xa01.80xa0cm2, C5/6xa0=xa01.84xa0cm2, C6/7xa0=xa01.89xa0cm2, C7/T1xa0=xa01.88xa0cm2. Values of SCDxa0<xa013xa0mm and IPDxa0<xa022.5xa0mm were associated with CCS and yielded sensitivities and specificities of 88–100xa0% at each level. Logistic regression demonstrated a significant association between these parameters and presence of CCS with ORxa0>xa018 at each level.ConclusionsBased on our study of a large population of adult skeletal specimens, we have defined CCS at each level. Values of SCDxa0<xa013xa0mm and IPDxa0<xa023xa0mm are strongly associated with the presence of CCS at all levels.

Does chronic warfarin cause increased blood loss and transfusion during lumbar spinal surgery

BACKGROUND CONTEXTnThe use of oral anticoagulation therapy such as warfarin is projected to increase significantly as the population ages and the prevalence of cardiovascular disease increases. Current recommendations state that warfarin be discontinued before surgery and the internationalxa0normalized ratio (INR) normalized.nnnPURPOSEnTo determine if stopping warfarin 7 days before surgery and correcting INR had any effect on intraoperative blood loss or the requirements for blood product transfusion.nnnSTUDY DESIGN/SETTINGnThis was a retrospective cohort study in a high-volume tertiary care center.nnnPATIENT SAMPLEnSample comprised 263 consecutive patients who underwent elective lumbar spinal surgery.nnnOUTCOME MEASUREnThe outcome measures were intraoperative blood loss, intraoperative blood transfusion, postoperative blood transfusion, and the number of blood products transfused.nnnMETHODSnThe records of patients undergoing elective spinal surgery were analyzed for patient demographic data, comorbidities, coagulation panel laboratory findings, operative characteristics, blood loss, and blood transfusion requirements. These included patients undergoing full laminectomies with or without posterolateral fusion and instrumentation. Patients on warfarin were analyzed for the mean dosage of warfarin and underlying pathology that required anticoagulation. All patients on warfarin had their anticoagulation therapy stopped 7 days before surgery and their INR checked preoperatively to confirm normalization. Both univariate and multiple linear regression analyses were performed.nnnRESULTSnThe patients on warfarin had a mean intraoperative blood loss of 839 mL compared with 441 mL for patients not on warfarin (p<.01). Multiple regression analysis determined that warfarin and number of spinal levels decompressed/fused/instrumented were predictors for increased blood loss (R(2)=0.37). Patients on warfarin also had increased postoperative blood transfusions (23.1% compared with 7.4%, p=.04). There was no significant difference between groups in terms of intraoperative blood transfusion or number of units transfused.nnnCONCLUSIONSnPatients on chronic anticoagulation therapy with warfarin who have their therapy stopped 7 days before surgery and have their INR normalized still demonstrated increased intraoperative blood loss and requirement for postoperative transfusion. Surgeons should be aware of the increased propensity of these patients to bleed despite adherence to protocols and should attempt to mitigate this risk.

Is lumbar stenosis associated with thoracic stenosis? A study of 1,072 human cadaveric specimens.

BACKGROUND CONTEXTnTandem stenosis of the cervical and lumbar spine is known to occur in 5% to 25% of individuals with symptomatic neural compression in one region. However, the prevalence of concurrent lumbar and thoracic stenosis is not known. Whether this relationship is because of an increased risk of degenerative diseases in these individuals or because of the tandem presence of stenosis in lumbar and thoracic canal is unknown.nnnPURPOSEnTo determine the prevalence of concurrent lumbar and thoracic stenosis, and whether the presence of stenosis in the lumbar spine is associated with stenosis in the thoracic spine.nnnSTUDY DESIGNnA morphoanatomic study of lumbar and thoracic cadaveric spines.nnnMETHODSnOne thousand seventy-two adult skeletal specimens from the Hamann-Todd Collection in the Cleveland Museum of Natural History were selected. Canal area at each level was also calculated using a geometric formula. A standard distribution for each level was created, and values that were 2 standard deviations below mean were considered as being stenotic. Linear regression analysis was used to determine the association between the additive canal areas at all levels in the lumbar and thoracic spine and between the number of stenotic lumbar and thoracic levels. Logistic regression was used to calculate the odds ratios (OR) for concurrent lumbar and thoracic stenosis.nnnRESULTSnThe prevalence of concurrent lumbar and thoracic stenosis is 1.42%. A positive association was found between the additive areas of all lumbar and thoracic levels (p<.01). No association, however, was found between the number of stenotic lumbar and thoracic levels (p=.7). Log regression demonstrated no significant association (OR <1) between stenosis in the lumbar and thoracic spine.nnnCONCLUSIONSnThe stenosis of the lumbar spine is not associated with the thoracic stenosis. Thus, stenosis in lumbar and thoracic levels does not seem to be contributed by tandem stenosis.