Hip fracture in women without osteoporosis.

The proportion of fractures that occur in women without osteoporosis has not been fully described, and the characteristics of nonosteoporotic women who fracture are not well understood. We measured total hip bone mineral density (BMD) and baseline characteristics including physical activity, falls, and strength for 8065 women aged 65 yr or older participating in the Study of Osteoporotic Fractures and then followed these women for hip fracture for up to 5 yr after BMD measurement. Among all participants, 17% had osteoporosis (total hip BMD T-score < or = -2.5). Of the 243 women with incident hip fracture, 54% were not osteoporotic at start of follow-up. Nonosteoporotic women who fractured were less likely than osteoporotic women with fracture to have baseline characteristics associated with frailty. Nevertheless, among nonosteoporotic participants, several characteristics increased fracture risk, including advancing age, lack of exercise in the last year, reduced visual contrast sensitivity, falls in the last year, prevalent vertebral fracture, and lower total hip BMD. These findings call attention to the many older women who suffer hip fracture but do not have particularly low antecedent BMD measures and help begin to identify risk factors associated with higher bone density levels.

Influence of workers' compensation eligibility upon functional recovery 10 to 28 years after polytrauma.

BACKGROUND: Previous studies have shown that work-related injuries are often associated with inferior outcomes. The aim of the current study was to compare the long-term functional outcome after polytrauma between work-related and non-work-related injuries at a minimum follow-up of 10 years. METHODS: Six hundred thirty-seven polytrauma patients were evaluated using a patient questionnaire and a physical examination. The average follow-up was 17.5 years (range 10-28 years); the average Injury Severity Score (ISS) was 20.7 (range 4 to 54). RESULTS: A multivariate analysis, with adjustments for age, sex, injury severity, and injury pattern, demonstrated that work-related injuries resulted in significantly inferior outcomes measured by the Hannove Score for Polytrauma Outcome (HASPOC), 12-Item Short-Form Health Survey (SF-12), requirement for medical aids and devices, length of rehabilitation, and retirement status (P < .05). CONCLUSIONS: Polytrauma patients receiving workers' compensation achieve significantly inferior long-term outcomes than other patients. The obtained results demonstrate that psychosocial variables such as insurance status have a significant impact on the functional recovery following polytrauma.

Distal radius fractures in older women: a 10-year follow-up study of descriptive characteristics and risk factors. The study of osteoporotic fractures.

OBJECTIVES: To determine the incidence of distal radius fractures and the characteristics of those fractures and to identify the key risk factors. DESIGN: Prospective cohort study, mean follow-up of 9.8 years. SETTING: Four clinical centers, one each in Baltimore, Maryland; Minneapolis, Minnesota; Pittsburgh, Pennsylvania; and Portland, Oregon. PARTICIPANTS: Nine thousand seven hundred four white women aged 65 and older, enrolled in the multicenter Study of Osteoporotic Fractures. METHODS: Five hundred twenty-seven distal radius fractures were confirmed by physician review of radiology reports; characteristics of the fractures were noted. Information was also collected on lifestyle, demographics, bone mineral density (BMD), and clinical and performance measures. RESULTS: The overall incidence of fracture was 7.3/1,000 person-years. Twenty-seven percent of the fractures were intra-articular; 73% were extra-articular. The independent predictors of fracture were decreased BMD (per 0.1 g/cm(2)) at the distal radius ( relative risk ( RR)=1.8, 95% confidence interval ( CI)=1.6-2.1), a history of recurrent falls ( RR=1.6, 95% CI=1.2-2.0), and having had a previous fracture since age 50 ( RR=1.3, 95% CI=1.1-1.6). Current use of oral estrogen was protective ( RR=0.6, 95% CI=0.4-0.8). For women aged 75 and older, poor cognitive status was also a predictor of wrist fracture. Intra-articular fractures occurred more than twice as frequently in women with diabetes mellitus. CONCLUSIONS: This is the first large long-term comprehensive study of distal radius fractures in older people. The results indicate that factors predictive of distal radius fractures can easily be assessed in routine clinical practice and can identify women at high risk for fracture. Selected preventive strategies could be designed to reduce the incidence of these fractures.

A community-based study of postmenopausal white women with back and leg pain: health status and limitations in physical activity.

BACKGROUND: The objective of this study was to determine the prevalence of lower back pain and associated leg pain/numbness in postmenopausal Caucasian women and the relationship of these symptoms to health status and function. METHODS: A convenience sample of 573 white women enrolled in the Observational Study of the Women's Health Initiative (WHI) in Pittsburgh completed a questionnaire on low back pain (LBP) and leg pain (LP) and its impact on their daily activity. For data analysis, this information was merged with that obtained under the standard WHI protocol. RESULTS: Almost half of the women (49%) reported having had LBP during the previous month: 8% had LBP only, while 41% had both LBP and LP. In 9% of women, the leg and back symptoms were alleviated by sitting. Among women with LBP during the previous month, those who also had leg pain were five times more likely to have had functional limitations, two to four times more likely to have consulted a clinician or taken medications, and more likely to have had prior spinal surgery or hospitalization than the women with no LP. Based on the Short Form-36, women with LBP/LP had significantly lower scores for physical function, physical role, and bodily pain than women with no LBP or with LBP alone. CONCLUSIONS: Low back pain that radiates into the hip, buttock, or leg is relatively common in postmenopausal Caucasian women living in the community and is associated with decreased physical health status and with physical limitations.

Foot and ankle fractures in elderly white women. Incidence and risk factors.

BACKGROUND: Although foot and ankle fractures are among the most common nonspinal fractures occurring in older women, little is known about their epidemiology. This study was designed to determine the incidence of and risk factors for foot and ankle fractures in a cohort of 9704 elderly, nonblack women enrolled in the multicenter Study of Osteoporotic Fractures. METHODS: At their first clinic visit, between 1986 and 1988, the women provided information regarding lifestyle, subjective health, and function. Bone mineral density was measured in the proximal and distal parts of the radius and in the calcaneus. The women were followed for a mean of 10.2 years, during which time 301 of them had a foot fracture and 291 had an ankle fracture. The fractures were classified with use of a modification of the Orthopaedic Trauma Association's guidelines. RESULTS: The incidence of foot fractures was 3.1 per 1000 woman-years, and the incidence of ankle fractures was 3.0 per 1000 woman-years. The most common ankle fracture was an isolated fibular fracture (prevalence, 57.6%), and the most common foot fracture was a fracture of the fifth metatarsal (56.9%). Women who sustained an ankle fracture had been slightly younger at the time of study enrollment than the women who did not sustain such a fracture (71.0 compared with 71.7 years), they had a higher body mass index (27.6 compared with 26.5), and they were more likely to have fallen within the twelve months prior to filling out the original questionnaire (38.1% compared with 29.7%). The appendicular bone mineral density was not significantly different between these two groups of subjects. Women who sustained a foot fracture had a lower bone mineral density in the distal part of the radius (0.345 g/cm (2) compared with 0.363 g/cm (2) ) and a lower calcaneal bone mineral density (0.394 g/cm (2) compared with 0.404 g/cm (2) ) than the women without a foot fracture, they were less likely to be physically active (62.3% compared with 67.8%), and they were more likely to have had a previous fracture after the age of fifty (45.5% compared with 36.8%) and to be using either long or short-acting benzodiazepines. CONCLUSIONS: Overall, foot fractures appeared to be typical osteoporotic fractures, whereas ankle fractures occurred in younger women with a relatively high body mass index.

Neck and shoulder pain in 70- to 79-year-old men and women: findings from the Health, Aging and Body Composition Study.

BACKGROUND CONTEXT: Musculoskeletal pain in the cervicobrachial region is considered a major health problem among adults of working age, but little is known about the impact of this pain in the elderly. PURPOSE: Determine the prevalence of neck and shoulder pain in a well-functioning cohort, identify factors associated with this pain, assess the pattern of coexisting joint pain and evaluate the impact of this pain on physical functioning. STUDY DESIGN: Cross-sectional study. PATIENT SAMPLE: Black and white men and women, aged 70 to 79 years, participating in the Health, Aging and Body Composition (Health ABC) study. OUTCOME MEASURES: Not applicable. METHODS: Between April 1997 and June 1998, 3,075 men and women participating in Health ABC study completed the initial home interview and clinical examination. Information was collected on musculoskeletal pain, medical history, depressive symptomatology and physical function. Physical performance measures were obtained. RESULTS: A total of 11.9% of participants reported neck pain of one month or more in duration and 18.9% reported shoulder pain. White women had the highest prevalence of neck pain (15.4%) and black women the highest prevalence of shoulder pain (24.3%). The correlates of both neck and shoulder pain were female gender, no education beyond high school, poorer self-rated health, depressive symptomatology and a medical history of arthritis, heart attack, angina. Increasing severity of both neck and shoulder pain was associated with an increased prevalence of joint pain at other body sites and with poor functional capacity. Measures of physical performance involving the upper extremity were also decreased. CONCLUSIONS: Neck and shoulder pain, either alone or in conjunction with pain in other joints, has a substantial impact on the function and well-being of the older adults in this cohort.

Lumbar spine listhesis in older African American women.

BACKGROUND CONTEXT: Degenerative changes in the lumbar spine may result in a loss of spinal stability and subluxation of one vertebra relative to another. Cadaveric studies and clinical case series have suggested that listhesis may be much more common in African Americans than in whites. PURPOSE: To determine the prevalence of lumbar spine listhesis (anterolisthesis and retrolisthesis) among African American women aged 65 years and older and the relationship of listhesis to low back pain, physical function and quality of life. STUDY DESIGN/SETTING: Cross-sectional study. PATIENT SAMPLE: A total of 481 African American women aged 65 years and older who were enrolled in the Study of Osteoporotic Fractures. These women were recruited from population-based listings in Baltimore, MD, Minneapolis, MN, Pittsburgh, PA, and Portland, OR. OUTCOME MEASURES: Not applicable. METHODS: Lateral radiographs of the lumbar spine were digitized, and listhesis (anterolisthesis and retrolisthesis) was assessed at spinal levels L3-L4, L4-L5 and L5-S1. Usable data were obtained for 470 women. Listhesis was defined as present when the subluxation (antero or retro) was 3 mm or more. RESULTS: The overall prevalence of anterolisthesis was 58.3% and varied by spinal level (13.2% at L3-L4, 36.5% at L4-L5 and 29.6% at L5-S1). The prevalence increased with age but was lower among oophorectomized women and those currently on estrogen replacement therapy. Anterolisthesis was not associated (p>.05) with disc height nor was it related to back function. Retrolisthesis occurred in 4% of women and was associated with decreased disc height and an increased prevalence of spinal problems and walking problems. CONCLUSIONS: The prevalence of anterolisthesis among older African American women living in the community was two to three times greater than that found in white women of a similar age. This condition was not related to an increased frequency of back problems nor did it adversely affect general physical function. Retrolisthesis was relatively rare but was associated with decreased back function.

Nausea and vomiting after outpatient ACL reconstruction with regional anesthesia: are lumbar plexus blocks a risk factor?

STUDY OBJECTIVE: To track the incidence of in-hospital postoperative nausea and vomiting (PONV) requiring postoperative parenteral nursing interventions after outpatient reconstruction of the anterior cruciate ligament (ACL) with one of two types of regional anesthesia to determine the extent to which various anesthetic techniques, preemptive antiemetics, and other factors were associated with the lowest probability of PONV. DESIGN: Retrospective chart (database) review of all ACL procedures at the University of Pittsburgh Medical Center from August 1997 through June 1999. SETTING: University medical center. MEASUREMENTS: We reviewed our institutional database of 347 consecutive patients undergoing ACL reconstruction with either spinal with femoral nerve block (SPI-FNB) or lumbar plexus and sciatic nerve block (LUM-SCI). Recorded variables and outcomes included gender, history of PONV, intravenous (i.v.) fentanyl before and during surgery, preemptive antiemetics given, and parenteral nursing interventions for PONV performed. Chi-square tests and logistic regression were used to determine factors associated with PONV. MAIN RESULTS: For SPI-FNB, PONV incidence was 13% (26/208), but it was higher for LUM-SCI [25%, 34/139, p = 0.002; odds ratio (OR) = 2.2]. Regression modeling demonstrated that women (OR = 2.8, p = 0.003) and LUM-SCI patients (OR = 3.0, p = 0.005) were at greater risk for PONV. The combination of dexamethasone (4 to 10 mg i.v.) and perphenazine (1.2 to 2.0 mg i.v.) was associated with less PONV (OR = 0.3, p = 0.005). Type of local anesthetic used for lumbar plexus block was not associated with PONV incidence. CONCLUSIONS: For ACL reconstruction with regional anesthesia, use of LUM-SCI was associated with a higher rate of PONV, whereas combination antiemetic prophylaxis with perphenazine and dexamethasone was associated with less PONV.

Evaluating and treating the stiff elbow.

The evaluation and treatment of the stiff elbow are described, as well as the lateral, medial, anterior, and posterior approaches for release of elbow contractures. The results after surgical release in 48 patients that failed nonoperative treatment for elbow contractures in our institution are reported. A literature review is provided.

Cervical spine injuries associated with the incorrect use of airbags in motor vehicle collisions.

STUDY DESIGN: Retrospective database review and analysis. OBJECTIVE: The purpose of this study is to determine the rate of cervical spine injuries with correct and incorrect use of front driver and passenger-side airbags. Summary of Background Data. Although there are abundant literature showing reduced injury severity and fatalities from seatbelts and airbags, no recent studies have delineated the affect of incorrect use of airbags in cervical spine injuries. METHODS: The database from the Pennsylvania Trauma Systems Foundation was searched for drivers and front-seat passenger injuries from 1990 to 2002. The resulting records were then grouped into those using both seatbelt and the airbag, airbag-only, seatbelt-only, and no restraints. The data were then analyzed for frequency of cervical spine fractures with or without spinal cord injury and injury severity indexes. RESULTS: The drivers using the airbag-only had significantly higher rate (54.1%) of cervical fractures than those using both airbag and a seatbelt (42.1%). Overall, drivers using the airbag-alone were 1.7 times more likely to suffer a cervical spine fracture than those using both protective devices. Likewise, passengers using the airbag-alone were 6.7 times more likely to suffer from a cervical spine fracture with spinal cord injury than those using both protective devices. In addition, the injury severity indexes (Glasgow coma scale, Injury Severity Score, Intensive Care Unit stays, and Total Hospital days) were significantly worse in patients who used an airbag-only. CONCLUSION: Airbag use without the concomitant use of a seatbelt is associated with a higher incidence of cervical spine fractures with or without spinal cord injuries. Airbag misuse is also associated with higher Injury Severity Score, lower Glasgow coma scale, and longer intensive care unit and total hospital stays, indicating that these patients suffer worse injury than those who use the airbag properly.

Mannose-binding lectin is a disease-modifying factor in North American patients with systemic lupus erythematosus.

OBJECTIVE: To investigate whether development of systemic lupus erythematosus (SLE), its clinical manifestations, and autoantibody production are associated with polymorphisms of the mannose-binding lectin (MBL) gene in North American patients with SLE. METHODS: MBL gene polymorphisms in codons 52 (designated variant D, with the wild-type designated A), 54 (variant B), and 57 (variant C) were determined by polymerase chain reaction-sequence specific priming in 130 patients with SLE and 142 healthy controls. Autoantibodies against double-stranded DNA (dsDNA), Smith antigen, phospholipids, Ro/SSA, La/SSB, and RNP were tested at certified clinical pathology laboratories. RESULTS: A statistically significant increased likelihood of anti-Smith antibody production was observed in SLE patients with the heterozygous A/B genotype [odds ratio (OR) 5.1; 95% confidence interval (CI) 1.6-16.6; the A/A genotype as the reference group] or A/C genotype (OR 8.2; 95% CI 2.0-33.9). SLE patients with the homozygous or compound heterozygous variant genotype (O/O; O, a common designation for variant alleles) had an increased likelihood of mounting autoantibody responses against dsDNA, Ro/SSA, and La/SSB, and were more likely to have a history of renal disease (OR 4.8; 95% CI 0.9-25.2). However, differences in the frequencies of MBL variant alleles and genotypes observed between patients with SLE and controls did not reach statistical significance. CONCLUSION: A significantly increased prevalence of anti-Smith antibody was associated with the heterozygous genotypes A/B and A/C. Although MBL structural gene polymorphism was not a risk factor for SLE development in this study population, homozygosity of MBL variant alleles may be a weak disease-modifying factor, particularly for renal involvement, in North American patients with SLE.

Measurement of lumbar lordosis: inter-rater reliability, minimum detectable change and longitudinal variation.

STUDY DESIGN: Repeated measures design to examine reliability and longitudinal variation of lumbar lordosis measurement. OBJECTIVES: To determine the interrater reliability, minimum detectable change (MDC) and longitudinal variation of the Cobb method for measuring lumbar lordosis using standardized rules. SUMMARY OF BACKGROUND DATA: The reliability of the 4-line Cobb method for measuring lumbar lordosis was not examined when standardized rules were instituted for drawing the lines. METHODS: A random sample of participants was selected from the Pittsburgh clinic of the multicenter Study of Osteoporotic Fractures for radiographic measurement of lumbar lordosis reliability (n=48) and stability (n=109). A standardized version of the 4-line Cobb method was used for all measurements of lordosis. The Intraclass Correlation Coefficient (ICC) was used to calculate interrater reliability for lordosis and to measure the stability of this measure over an approximate 2-year-time period. The standard error of measurement and MDC were calculated for lordosis measurement based on the ICC value. RESULTS: The interrater reliability coefficient for lumbar lordosis was in the excellent range (ICC=0.98; 95% CI: 0.95, 0.99). The MDC based on measurements between raters was 3.90 degrees. The ICC value for the stability, or reliability from time 1 to time 2, of lordosis measurement over time was 0.81 (95% CI: 0.74, 0.87). CONCLUSION: This study demonstrates that the 4-line Cobb method can be a highly reliable and precise method for measuring lumbar lordosis if standardized procedures are used. The Cobb method has an MDC that is appropriate for clinical use. Also, there is minimal longitudinal variation in lordosis measurements over a 2-year period.

Prevalence of symptoms of cervical and lumbar stenosis among participants in the Osteoporotic Fractures in Men Study.

STUDY DESIGN: Cross-sectional. OBJECTIVES: To determine the prevalence of symptoms typical of cervical and lumbar stenosis, evaluate the relationship between lumbar and cervical symptoms, and assess the impact of these symptoms on health status. SUMMARY OF BACKGROUND DATA: Degenerative changes of the spine frequently associated with aging, may result in stenosis, a narrowing of the spinal canal. Little is known about the prevalence or health impact of symptoms associated with stenosis in older individuals. METHODS: Between March 2000 and April 2002, 5995 men aged > or = 65 years participating in the Osteoporotic Fractures in Men Study completed a self-administered questionnaire and clinical examination. Information was collected on demographics, spinal/joint health, and general health status. RESULTS: Overall, 14.4% of men had had clinically relevant neck pain during the previous year, and almost half this group (6.5%) had numbness/tingling/weakness (NTW) extending into the arm; 26.2% reported clinically relevant lower back pain, which in 12.2%, was accompanied by NTW extending into the leg. Men with spinal pain (neck or lower back) accompanied by NTW radiating into a limb had poorer health status than those with milder pain. CONCLUSIONS: Symptoms suggestive of cervical and lumbar stenosis are relatively common among this cohort of older men, and generalized spinal stenosis may occur in as many as 4%.

Reduction of verbal pain scores after anterior cruciate ligament reconstruction with 2-day continuous femoral nerve block: a randomized clinical trial.

BACKGROUND: Single-injection femoral nerve block analgesia and spinal anesthesia have been associated with fewer postoperative nursing interventions and successful same-day discharge after anterior cruciate ligament reconstruction. In the current study, the authors prospectively determined the effect of continuous femoral nerve block on a numeric rating scale (NRS) of pain intensity with movement for 7 postoperative days. METHODS: Patients undergoing this surgery with no history of previous invasive surgery on the same knee were recruited for this study. After standardized spinal anesthesia, intravenous sedation, and perioperative multimodal analgesia, patients received a femoral nerve catheter with (1) saline bolus (30 ml) plus saline infusion (270 ml at 5 ml/h, placebo group); (2) levobupivacaine (0.25%) bolus with saline infusion (group I), or (3) levobupivacaine (0.25%) bolus and infusion (group II). Patients were surveyed preoperatively and on postoperative days 1-4 and 7 to determine NRS scores (scale 0-10). RESULTS: Data from 233 participants were analyzed. On days 1-2, 50% of placebo patients had NRS scores of 5 or above, whereas among group II patients, only 25% had scores of 5 or above (P < 0.001). In regression models for NRS scores during days 1-4, group II was the only factor predicting lower pain scores (odds ratios, 0.3-0.5; P = 0.001-0.03). Overall, patients with preoperative NRS scores greater than 2 were likely to report higher NRS scores during days 1-7 (odds ratios, 3.3-5.2; P < 0.001). CONCLUSIONS: Femoral nerve block catheters reliably keep NRS scores below the moderate-to-severe pain threshold for the first 4 days after anterior cruciate ligament reconstruction.

Analgesic usage for low back pain: impact on health care costs and service use.

STUDY DESIGN: Cross-sectional analysis of analgesic use by patients with low back pain (LBP). OBJECTIVES: To describe patterns of analgesic use and their cost implications for the use of other care services among individuals with LBP enrolled in a health insurance plan during 2001. It was hypothesized that the use of analgesics would be most frequent among patients with LBP with neurologic findings. SUMMARY OF BACKGROUND DATA: National guidelines have recommended analgesics as the primary pharmacologic treatment of LBP. The choice of specific analgesics has major cost and service use implications. METHODS: The University of Pittsburgh Health System includes 18 affiliated hospitals, more than 5000 physicians, and a commercial health plan with 255,958 members in 2001. This study uses the System Health Plan's insurance claims database to identify members who had services provided for one of 66 International Classification of Diseases, Version 9, Clinical Modification codes that identify mechanical LBP (n = 17,148). RESULTS: In 2001, 7631 (43.5%) members with claims for LBP services had no analgesic pharmacy claims. The other 9517 (55.5%) had analgesics claims costing a total of $1.4 million; 68% of claimants were prescribed an opioid and 58% nonselective nonsteroidal antiinflammatory drugs (NSAID). The costs of opioids, NSAID, and cyclooxygenase-2 selective NSAID for patients with LBP represented 48%, 24%, and 28%, respectively, of total health plan expenditures for all uses of these drugs, including cancer. Opioid use was associated with the high volume usage of LBP care services. Patients with LBP with and without neurologic involvement and those with acquired lumbar spine structural disorders had similar patterns of analgesic use: those with congenital structural disorders were less likely to use analgesics; and those with psychogenic pain and LBP related to orthopedic devices were more likely to use opioids. CONCLUSIONS: With this health plan, a high proportion of patients with LBP had claims for opioids during 2001. The use of opioids by patients with LBP represents a major cost for the health plan, and is associated with specific patient characteristics and their use of other LBP services.

A slowly progressive and reproducible animal model of intervertebral disc degeneration characterized by MRI, X-ray, and histology.

STUDY DESIGN: The progression of intervertebral disc degeneration following anterolateral "stab" of adult rabbit lumbar discs by 16-gauge hypodermic needle to a limited (5-mm) depth was studied for up to 24 weeks using magnetic resonance imaging, radiograph, and histologic outcome measures. OBJECTIVES: To develop a slowly progressive, reproducible rabbit model of intervertebral disc degeneration suitable for studying pathogenesis and pathophysiology of intervertebral disc degeneration and testing safety and efficacy of novel approaches to the treatment of intervertebral disc degeneration (e.g., growth factors, gene therapy, cell therapy, and tissue engineering). SUMMARY OF BACKGROUND DATA: Numerous animal models of intervertebral disc degeneration have been proposed in the literature, each with attendant advantages and disadvantages. The classic "stab model," involving full-thickness stab of anterior anulus fibrosus of adult rabbit lumbar discs by a number 11 scalpel blade, appears to produce changes in certain biochemical and histologic outcome measures that are similar to changes seen in human intervertebral disc degeneration. However, the immediate herniation of nucleus pulposus on full-thickness stab renders this model less suitable for 1) studying effects of less precipitous changes in nucleus pulposus and anulus fibrosus that may be important in the onset and progression of intervertebral disc degeneration and 2) testing novel therapeutic approaches that target the processes of early intervertebral disc degeneration. METHODS: The L2-L3, L3-L4, and L4-L5 lumbar intervertebral discs of 18 skeletally mature female New Zealand White rabbits were stabbed by 16-gauge hypodermic needle to a depth of 5 mm in the left anterolateral anulus fibrosus. Serial magnetic resonance imaging scans of the stabbed discs and intact L1-L2 and L5-L6 control discs were performed at 3, 6, 12, and 24 weeks post surgery and compared with preoperative magnetic resonance images. Supplemental radiograph and histologic analyses were performed. RESULTS: The stabbed discs exhibited a progressive decrease in "magnetic resonance imaging index" (the product of nucleus pulposus area and signal intensity from T2-weighted midsagittal plane images) starting at 3 weeks post stab and continuing through 24 weeks, with no evidence of spontaneous recovery or reversal of magnetic resonance imaging changes. Radiograph findings included early osteophyte formation by 6 weeks post stab and extensive, bridging osteophytes by 24 weeks. Histologic analysis revealed progressive loss of notochordal cells from the nucleus pulposus, filling of the nucleus pulposus space with fibrocartilage, and derangement of anulus fibrosus. CONCLUSIONS: Stabbing the anterolateral anulus fibrosus of adult rabbit lumbar discs with a 16-gauge hypodermic needle to a limited (5-mm) depth results in a number of slowly progressive and reproducible magnetic resonance imaging, radiograph, and histologic changes over 24 weeks that show a similarity to changes seen in human intervertebral disc degeneration. This model would appear suitable for studying pathogenesis and pathophysiology of intervertebral disc degeneration and testing safety and efficacy of novel treatments of intervertebral disc degeneration.

Pediatric spinal cord injury without radiographic abnormality (SCIWORA): the absence of occult instability and lack of indication for bracing.

STUDY DESIGN: A retrospective review of medical records and imaging studies of children diagnosed with spinal cord injury without radiographic abnormality (SCIWORA) or SCIWORA-like symptoms at Children's Hospital of Pittsburgh between 1965 and 1999 was undertaken. OBJECTIVES: To evaluate the existence of occult segmental spinal instability and a role for bracing as treatment for SCIWORA, we contrasted the Children's Hospital of Pittsburgh experience with literature reports on SCIWORA. SUMMARY OF BACKGROUND DATA: There is a great deal of confusion and conflicting evidence regarding pediatric SCIWORA in the literature. Previous reports from our institution reported unique findings, including the only description of serious, recurrent SCIWORA in the literature. These findings have frequently been cited as the justification for long-term immobilization in all cases of SCIWORA. METHODS: All records on patients coded as spinal cord injury without fracture or dislocation (ICD-9 code 952.xx) were reviewed. Children 17 years of age or younger with traumatic spinal cord injury and normal plain radiographic findings were included. Penetrating trauma, infection, or metabolic diseases were excluded. RESULTS: A total of 189 patients were diagnosed with SCIWORA at our institution over the 35-year review period. These patients differed from those reported in the literature with respect to a higher incidence, older age, less involved neurologic injury, and more low-energy mechanisms, such as sports and falls. There were no cases of a patient with SCIWORA who deteriorated and developed a permanent neurologic deficit after having either recovered or plateaued from an initial SCIWORA. All recurrent SCIWORA recovered to normal neurologic function. Bracing did not demonstrate any benefit in preventing these minor recurrent SCIWORAs. CONCLUSION: We identified no cases of serious, recurrent SCIWORA at our institution from 1965 to 1999. A case-by-case evaluation is required for the treatment of spinal cord injury without apparent spinal column injury, and bracing is not uniformly indicated.

Superior mesenteric artery syndrome in scoliosis surgery: weight percentile for height as an indicator of risk.

A retrospective analysis of charts identified cases of superior mesenteric artery (SMA) syndrome occurring after scoliosis surgery over a 23-year period. Despite numerous reports on this potentially fatal complication of scoliosis surgery, no method exists to stratify patients for risk of developing disease after spine surgery. A study of charts was performed to identify all cases of SMA syndrome occurring after scoliosis surgery from 1972 to 1995. An upper gastrointestinal study with findings specific for the syndrome was requisite for inclusion. Patients' weight and height at the time of diagnosis of SMA syndrome were recorded. Based on standard national data tables, a percentile for weight, percentile for height, and a weight percentile for height were derived for each patient. The syndrome occurred after posterior spinal fusion in six patients (three boys, three girls). The average weight percentile for height, available in five of the six patients, was 3%, significantly different from both age-matched controls in the general population and from age-matched controls undergoing posterior spinal fusion for adolescent idiopathic scoliosis. This study, the largest reported from a single institution, suggests that a weight percentile for height of 5% is the degree of asthenia that allows compromise of the duodenum. The percentile identifies patients at risk for SMA syndrome for the purposes of increasing postoperative vigilance for gastrointestinal complaints, decreasing the threshold for diagnostic workup, and guiding perioperative dietary supplementation.