Risk Factors of Extended Hospital Stay After One-Level Anterior Cervical Discectomy Fusion or Disc Replacement: Results from 1004 Patients in Food and Drug Administration Trials.

BACKGROUND: Extended length of stay (LOS) after surgery is costly to the health care system and can be distressing to the patient and family. Previous studies have shown conflicting data on factors associated with increased LOS and are limited by using multiple different surgeries. Our study seeks to analyze factors that are associated with extended LOS. OBJECTIVE: The objective of this study was to analyze data from 2 Food and Drug Administration trials of one-level cervical surgery to identify risk factors that are associated with extended LOS in the hospital. METHODS: Extended LOS was defined to be >1 day. Patients with LOS ≤1 day were compared with those with LOS >1 day. Data from the BRYAN and Prestige ST Trial (n = 1004) were analyzed. Subjects with LOS ≤1 day were compared with those with LOS >1 day. Variables analyzed for their effect on LOS included demographic characteristics, patient-reported outcome measures, preoperative medical conditions, preoperative neurologic status, and intraoperative factors. RESULTS: A total of 912 patients (90.84%) had an LOS ≤1 day and 92 patients (9.16%) had an extended LOS >1 day. Weak narcotic medication use (P = 0.021; odds ratio [OR], 1.72), Nurick gait (P = 0.019; OR, 1.796), and operative time (P < 0.0001; OR, 2.062) were found to significantly affect LOS. CONCLUSIONS: Nurick gait, operative time, and history of weak narcotic use are associated with extended hospital stay. These data may be useful in preoperatively counseling patients, developing quality metrics for hospitals, and helping create financial models for cost/diagnosis-related group reimbursement for single-level anterior cervical surgery.

Laminectomy and fusion versus laminoplasty for the treatment of degenerative cervical myelopathy: results from the AOSpine North America and International prospective multicenter studies.

BACKGROUND CONTEXT: It remains unclear whether cervical laminoplasty (LP) offers advantages over cervical laminectomy and fusion (LF) in patients undergoing posterior decompression for degenerative cervical myelopathy (DCM). PURPOSE: The objective of this study is to compare outcomes of LP and LF. STUDY DESIGN/SETTING: This is a multicenter international prospective cohort study. PATIENT SAMPLE: A total of 266 surgically treated symptomatic DCM patients undergoing cervical decompression using LP (N=100) or LF (N=166) were included. OUTCOME MEASURES: The outcome measures were the modified Japanese Orthopaedic Association score (mJOA), Nurick grade, Neck Disability Index (NDI), Short-Form 36v2 (SF36v2), length of hospital stay, length of stay in the intensive care unit, treatment complications, and reoperations. METHODS: Differences in outcomes between the LP and LF groups were analyzed by analysis of variance and analysis of covariance. The dependent variable in all analyses was the change score between baseline and 24-month follow-up, and the independent variable was surgical procedure (LP or LF). In the analysis of covariance, outcomes were compared between cohorts while adjusting for gender, age, smoking, number of operative levels, duration of symptoms, geographic region, and baseline scores. RESULTS: There were no differences in age, gender, smoking status, number of operated levels, and baseline Nurick, NDI, and SF36v2 scores between the LP and LF groups. Preoperative mJOA was lower in the LP compared with the LF group (11.52±2.77 and 12.30±2.85, respectively, p=.0297). Patients in both groups showed significant improvements in mJOA, Nurick grade, NDI, and SF36v2 physical and mental health component scores 24 months after surgery (p<.0001). At 24 months, mJOA scores improved by 3.49 (95% confidence interval [CI]: 2.84, 4.13) in the LP group compared with 2.39 (95% CI: 1.91, 2.86) in the LF group (p=.0069). Nurick grades improved by 1.57 (95% CI: 1.23, 1.90) in the LP group and 1.18 (95% CI: 0.92, 1.44) in the LF group (p=.0770). There were no differences between the groups with respect to NDI and SF36v2 outcomes. After adjustment for preoperative characteristics, surgical factors and geographic region, the differences in mJOA between surgical groups were no longer significant. The rate of treatment-related complications in the LF group was 28.31% compared with 21.00% in the LP group (p=.1079). CONCLUSIONS: Both LP and LF are effective at improving clinical disease severity, functional status, and quality of life in patients with DCM. In an unadjusted analysis, patients treated with LP achieved greater improvements on the mJOA at 24-month follow-up than those who received LF; however, these differences were insignificant following adjustment for relevant confounders.

A comparison of computed tomography measures for diagnosing cervical spinal stenosis associated with myelopathy: a case-control study.

STUDY DESIGN: Retrospective comparative study. PURPOSE: To assess differences in computed tomography (CT) imaging parameters between patients with cervical myelopathy and controls. OVERVIEW OF LITERATURE: There is a lack of information regarding the best predictor of symptomatic stenosis based on osseous canal dimensions. We postulate that smaller osseous canal dimensions increase the risk of symptomatic central stenosis. METHODS: CT images and medical records of patients with cervical myelopathy (19 patients, 8 males; average age, 64.4±13.4 years) and controls (18 patients, 14 males; average age, 60.4±11.0 years) were collected. A new measure called the laminar roof pitch angle (=angle between the lamina) was conducted along with linear measures, ratios and surrogates of canal perimeter and area at each level C2-C7 (222 levels). Receiver-operator curves were used to assess the diagnostic value of each. Rater reliability was assessed for the measures. RESULTS: The medial-lateral (ML) diameter (at mid-pedicle level) and calculated canal area (=anterior-posterior.×ML diameters) were the most accurate and highly reliable. ML diameter below 23.5 mm and calculated canal area below 300 mm(2) generated 82% to 84% sensitivity and 67% to 68% sensitivity. No significant correlations were identified between age, height, weight, body mass in dex and gender for each of the CT measures. CONCLUSIONS: CT measures including ML dimensions were most predictive. This study is the first to identify an important role for the ML dimension in cases of slowly progressive compressive myelopathy. A ML reserve may be protective when the canal is progressively compromised in the anterior-posterior dimension.

Quantitative differences in intervertebral disc-matrix composition with age-related degeneration.

This study was carried out to determine the effect of age on the intervertebral disc, using a rabbit model. Anulus fibrosus and nucleus pulposus tissue from New Zealand white rabbits aged 3 years old (old rabbits) and 6 months old (young rabbits) were used. The water content, the proteoglycan, the DNA content, and the mRNA levels of aggrecan, type I collagen, and type II collagen were all measured for each sample. Water, proteoglycan, DNA, and the mRNA levels of aggrecan and type II collagen were all greater in the nucleus pulposus of the young rabbits as compared to the old. For the anulus fibrosus, the difference between young and old is less marked with only proteoglycan and DNA being greater in the young disc as compared to the old. Clearly, according to our results, it is the nucleus pulposus that suffers the brunt of the changes with age.

A comparison of three cell types as potential candidates for intervertebral disc therapy: annulus fibrosus cells, chondrocytes, and bone marrow derived cells.

OBJECTIVES: Candidate cell types for disc cell transplantation therapy include anulus fibrosus (AF) cells, chondrocytes, and bone marrow derived cells (BMDCs). We compared the disc matrix production in these three types of cells, before and after stimulation with rhBMP-2. There is no study extant that compares these three cell types to determine the best candidate for the disc cell therapy. METHODS: AF cells, chondrocytes, and BMDCs (iliac crest and femur) were isolated and grown in monolayer. They were treated for 3 days with rhBMP-2. After 3 days, proteoglycan (sGAG) content in the media was quantified. The results were normalized by cell numbers. The mRNA expression of aggrecan, type I collagen, and type II collagen was measured using real-time PCR. Each cell type was also cultured in chamber slides and immunostained for aggrecan, type I collagen, and type II collagen after 3 days of treatment with rhBMP-2. RESULTS: (1) Without rhBMP-2 the chondrocytes produced more proteoglycan (sGAG) as compared to the other two cell types (AF cells and BMDCs). After stimulation with rhBMP-2 the chondrocytes produce even more proteoglycan than the other two cell types. (2) As compared to the other two cell types, in terms of mRNA expression, the chondrocytes expressed more aggrecan, type I collagen, and type II collagen before stimulation with rhBMP-2. After rhBMP-2 stimulation, the chondrocytes expressed even more aggrecan, type I collagen, and type II collagen in proportion to the concentration of rhBMP-2. For the BMDCs there were no changes in type I and II collagen. (3) rhBMP-2 stimulation produced increases in the protein levels of aggrecan, type I and II collagen in all three types of cells. CONCLUSIONS: On balance, according to these results, it would seem that chondrocytes are the best candidate for the disc cell therapy.