The Impact of COVID-19 Redeployment on an Orthopedic Surgery Department at a Tertiary Care Medical Center in New York City.

BACKGROUND: The SARS-CoV-2 (COVID-19) pandemic resulted in new, non-orthopedic roles for many members of our New York City based orthopedic department, including redeployment to medicine wards, emergency departments, and intensive care units. The purpose of this study was to determine if certain areas of redeployment predisposed individuals to higher likelihood of positive diagnostic or serologic testing for COVID-19. METHODS: In this study, attendings, residents, and phy-sician assistants within our orthopedic department were surveyed to determine their roles during the COVID-19 pandemic and whether they were tested via diagnostic or serologic methods for detecting COVID-19. Additionally, symptoms and missed days of work were reported. RESULTS: No significant association between redeployment site and rate of positive COVID-19 diagnostic (p = 0.91) or serologic (p = 0.38) testing was detected. Sixty individuals responded to the survey, with 88.3% of respondents rede-ployed during the pandemic. Nearly half (n = 28) of those redeployed experienced at least one COVID-19 related symptom. Two respondents had a positive diagnostic test, and 10 had a positive serologic test. CONCLUSIONS: Area of redeployment during the COVID-19 pandemic is not associated with an increased risk of subse-quently having a positive diagnostic or serologic COVID-19 test.

Mid-term outcomes after reverse total shoulder arthroplasty with latissimus dorsi transfer.

Background: Reverse total shoulder arthroplasty is a common treatment for patients with rotator cuff arthropathy who have failed a prior rotator cuff repair. Latissimus dorsi transfer can be performed simultaneously to reverse total shoulder arthroplasty for patients with preoperative external rotation deficiency. Current literature is limited with several studies providing functional and pain improvements at short-term follow-up; however, there is a deficit in data regarding mid-term outcomes. The purpose of this study was to evaluate the clinical and radiographic outcomes following reverse total shoulder arthroplasty with latissimus dorsi transfer with mid-term follow-up. We hypothesized significant improvement in external rotation and shoulder functionality for patients with preoperative external rotation lag. Methods: We retrospectively reviewed patients who underwent reverse total shoulder arthroplasty with latissimus dorsi transfer. Preoperative and postoperative changes in range of motion were assessed. American Shoulder and Elbow Surgeon Score and the Simple Shoulder Test were used to evaluate changes in shoulder function while pain scores were assessed using the Visual Analog Scale (VAS). Radiographs were reviewed for rotator cuff arthropathy, fatty infiltration, scapular notching, baseplate loosening, and osteolysis. We reported frequency and mean ± standard deviation for categorical and continuous variables, respectively. Means were compared using the paired Student's t-test and proportions using the Chi-square test. Results: Fifteen patients met the inclusion criteria. The mean age of the cohort was 71.7 ± 8.4 years (range 51.2-87.8 years) with a mean follow-up of 6.3 ± 4.1 years (range 1.0-14.5 years). Reverse total shoulder arthroplasty with latissimus dorsi transfer improved external rotation (-7 ± 21.3° to 38 ± 15.8°; p value = 0.001). There was no statistically significant difference regarding forward flexion (116.3 ± 45.4° to 133.7 ± 14.7°; p value = 0.17) and internal rotation (T12 to L2; p value = 0.57). The procedure led to an increase in American Shoulder and Elbow Surgeon Score scores (37 ± 19 to 62 ± 22; p = 0.005) and Simple Shoulder Test scores (2 ± 2 to 6 ± 3; p value = 0.001) with a significant reduction in Visual Analog Scale scores (5 ± 3 to 2 ± 3; p value = 0.022). The procedure corrected external rotation lag in 10 patients. Radiographically, rotator cuff arthropathy was found to be grade 3 in two patients, grade 4 A in four patients, grade 4B in eight patients, and grade 5 in one patient. On postoperative imaging, scapular notching was found in six patients (40%). Twelve patients had cortical humeral erosion at the site of the latissimus dorsi transfer. Only one patient experienced a shoulder-related complication which was aseptic baseplate loosening and required a revision reverse total shoulder arthroplasty with allograft. Conclusions: In this study, patients undergoing reverse total shoulder arthroplasty with latissimus dorsi transfer experienced improvements in range of motion, functional scores, and pain at mid-term follow-up. The shoulder-related complication rate was low.Level of evidence: IV; Case series.

New Approaches to the Diagnosis and Management of Periprosthetic Joint Infection of the Shoulder.

Periprosthetic joint infection (PJI) of the shoulder is a potentially devastating complication following shoulder arthroplasty. It is important to review the workup of PJI in the shoulder, including recently developed diagnostic criteria for shoulder PJI, along with detailed examination of the most common causative organism, Cutibacterium acnes. Treatment strategies for PJI of the shoulder include antibiotic therapy, surgical options, and what to do with unexpected positive cultures in revision arthroplasty. Surgeons should be familiar with bony and soft-tissue reconstructive options following explantation of an infected shoulder prosthesis.

Long-term clinical and radiographic outcomes of total shoulder arthroplasty in patients under age 60 years.

BACKGROUND: We aimed to characterize the long-term clinical and radiographic outcomes of total shoulder arthroplasty (TSA) in patients aged < 60 years. We hypothesized meaningful improvements in shoulder functionality and pain with TSA and an acceptably low rate of prosthesis complications and revisions. METHODS: This was a retrospective cohort study of 29 patients (34 shoulders) undergoing TSA before age 60 years with a minimum follow-up period of 10 years. Shoulder range of motion, functionality (American Shoulder and Elbow Surgeons and Simple Shoulder Test scores), and pain (visual analog scale score) were evaluated. Radiographs were assessed for lateral humeral offset, the acromiohumeral interval, and glenoid loosening. RESULTS: The mean age of the patients was 54.4 ± 5.5 years (range, 35.5-59.8 years), with a mean follow-up period of 16.1 ± 4.5 years (range, 10.0-26.1 years). In patients aged < 60 years, TSA significantly improved forward elevation (from 119° ± 26° to 146° ± 21°, P = .0002), external rotation (from 21° ± 25° to 52° ± 15°, P = .0001), and internal rotation (from L5 to L1, P = .002). Additionally, TSA significantly increased American Shoulder and Elbow Surgeons scores (from 32 ± 20 to 64 ± 27, P = .0008) and Simple Shoulder Test scores (from 3 ± 2 to 7 ± 4, P = .0004) and reduced visual analog scale pain scores (from 7 ± 3 to 3 ± 3, P = .0001). Radiographically, there was no significant difference in mean lateral humeral offset (13 ± 6 mm vs. 10 ± 12 mm, P = .472) or the mean acromiohumeral interval (20 ± 4.2 mm vs. 16 ± 6 mm, P = .061) between immediate postoperative and final follow-up radiographs. Radiographic evidence of glenoid loosening was noted in 2 patients. Complications occurred in 6 patients (17.6%), all of which were cases of aseptic glenoid loosening. Ultimately, 4 patients underwent conversion to a reverse TSA and 2 underwent arthroscopic glenoid removal. The rate of prosthesis survivorship was 97.1% (95% confidence interval [CI], 91.4%-100%) at 10 years, 85.4% (95% CI, 73.7%-97.2%) at 15 years, and 80.1% (95% CI, 65.1%-98.4%) at 20 years. DISCUSSION: TSA consistently improved shoulder functionality and reduced pain while limiting the need for further revisions. These findings suggest that TSA is a viable treatment option for glenohumeral arthritis in younger patients.

Trends in Periprosthetic Knee Infection and Associated Costs: A Population-Based Study Using National Data.

Given increasing demand for primary knee arthroplasties, revision surgery is also expected to increase, with periprosthetic joint infection (PJI) a main driver of costs. Recent data on national trends is lacking. We aimed to assess trends in PJI in total knee arthroplasty revisions and hospitalization costs. From the National Inpatient Sample (2003-2016), we extracted data on total knee arthroplasty revisions (n = 782,449). We assessed trends in PJI prevalence and (inflation-adjusted) hospitalization costs (total as well as per-day costs) for all revisions and stratified by hospital teaching status (rural/urban by teaching status), hospital bed size (≤299, 300-499, and ≥500 beds), and hospital region (Northeast, Midwest, South, and West). The Cochran-Armitage trend test (PJI prevalence) and linear regression determined significance of trends. PJI prevalence overall was 25.5% (n = 199,818) with a minor increasing trend: 25.3% (n = 7,828) in 2003 to 28.9% (n = 19,275) in 2016; p < 0.0001. Median total hospitalization costs for PJI decreased slightly ($23,247 in 2003-$20,273 in 2016; p < 0.0001) while median per-day costs slightly increased ($3,452 in 2003-$3,727 in 2016; p < 0.0001), likely as a function of decreasing length of stay. With small differences between hospitals, the lowest and highest PJI prevalences were seen in small (≤299 beds; 22.9%) and urban teaching hospitals (27.3%), respectively. In stratification analyses, an increasing trend in PJI prevalence was particularly seen in larger (≥500 beds) hospitals (24.4% in 2003-30.7% in 2016; p < 0.0001), while a decreasing trend was seen in small-sized hospitals. Overall, PJI in knee arthroplasty revisions appears to be slightly increasing. Moreover, increasing trends in large hospitals and decreasing trends in small-sized hospitals suggest a shift in patients from small to large volume hospitals. Decreasing trends in total costs, alongside increasing trends in per-day costs, suggest a strong impact of length of stay trends and a more efficient approach to PJI over the years (in terms of shorter length of stay).

Posterior Spinal Fusion With Multilevel Posterolateral Convex Disc Releases for the Treatment of Severe Thoracolumbar Scoliosis.

BACKGROUND: Severe, rigid thoracolumbar scoliosis presents a surgical challenge to achieve 3-dimensional correction, maximize distal motion segments, and avoid operative morbidity conferred by combined anterior-posterior approaches or 3-column osteotomies. We present a new approach for releasing these curves, using multilevel posterolateral convex disc release (PCDR) and posterior instrumented fusion. METHODS: There were 3 adults and 1 adolescent (mean age, 31.8 years; 2 females) with severe progressive thoracic and transforaminal lumbar (major) idiopathic scoliosis (IS) who were treated with 3-level PCDR, multiple posterior column osteotomies, and posterior instrumented thoracolumbar fusion with all-pedicle screw constructs. RESULTS: Restoration of global coronal and sagittal alignment was achieved for all patients (minimum 2-year follow-up). Lowest instrumented vertebra (LIV) was L4 in 2 patients and L3 in the remaining 2. All except 1 were fused to the lower end vertebra. Postoperatively, mean thoracolumbar curve was reduced from 77.3° (range, 69°-91°) to 21.8° (72%Δ), LIV tilt decreased from 26.8° to 8.3°, and LIV translation improved (2.5-1.2 cm; 58%Δ), whereas lumbar lordosis remained unchanged. Average central sacral vertical line shift measured via C7 sagittal vertical axis changed from 1.4 to -0.7 cm. There were no complications except for dysesthesias in the lower extremity on the side of the PCDR in 1 patient, which resolved after 3 months. CONCLUSIONS: Severe thoracolumbar IS presents a surgical challenge to achieve 3-dimensional correction, minimize fusion levels, and avoid procedural morbidity. PCDR is a novel technique that may facilitate this correction with minimal procedure-related morbidity.

Revision rotator cuff repair: a systematic review.

BACKGROUND: The incidence of revision rotator cuff repair (RCR) has increased along with the incidence of primary RCR over the past 2 decades. The purpose of this study was to perform a systematic review to analyze the clinical outcomes of revision RCR and chiefly to identify prognostic factors that may influence postoperative outcomes. METHODS: The PubMed, MEDLINE (Ovid), Embase (Elsevier), and Cochrane Library (Wiley) databases were searched from database inception through November 2018 for studies assessing revision RCR. All studies were screened in duplicate for eligibility. Pooled analysis correlations between mean preoperative range-of-motion measures, American Shoulder and Elbow Surgeons (ASES) scores, and visual analog scale (VAS) pain scores and mean postoperative outcomes with revision RCR were examined via linear regression and reported with the strength of the Spearman correlation coefficient (rs). RESULTS: A total of 22 studies met the inclusion criteria, including 3 level III and 19 level IV studies. Mean preoperative forward flexion had the greatest correlation with the mean postoperative ASES score (rs = 0.98). A strong positive correlation was also found between mean preoperative forward flexion and mean postoperative forward flexion (rs = 0.83). The mean preoperative VAS pain score was strongly correlated with the mean postoperative VAS pain score (rs = 0.88) and demonstrated a moderate negative association with the mean postoperative ASES score (rs = -0.48). Finally, the mean preoperative ASES score was moderately correlated with the mean postoperative ASES score (rs = 0.56). CONCLUSIONS: The results of this systematic review demonstrate favorable clinical outcomes following RCR revision performed both in an open manner and arthroscopically. Preoperative forward flexion was identified as a possible prognostic factor for improved outcomes.

Body Image Disturbance Improvement After Operative Correction of Adolescent Idiopathic Scoliosis.

HYPOTHESIS: Body Image Disturbance Questionnaire-Scoliosis version (BIDQ-S) is a sensitive outcomes instrument to evaluate improvements in body image-related psychosocial effects with surgical correction. DESIGN: Prospective observational study. INTRODUCTION: The BIDQ-S was previously validated (convergent validity, internal consistency) as a tool to assess body image-related distress and psychosocial impairment in adolescent idiopathic scoliosis (AIS). This study was conducted to evaluate responsiveness to change in the BIDQ-S associated with surgical treatment of AIS two years postoperatively to complete the validation of this questionnaire. METHODS: Seventy-five consecutive operative AIS patients were enrolled and completed BIDQ-S and Scoliosis Research Society-22 (SRS-22) at preoperative and two-year postoperative visits. Demographic and radiographic data were collected. Preoperative and two-year postoperative BIDQ-S (1 = best, 5 = worst) and SRS-22 scores (1 = worst, 5 = best) were compared using paired t test. Correlations between BIDQ-S and SRS-22 scores were evaluated by linear regression. RESULTS: Eighty-four percent of the subjects were females, with average age at surgery of 14.4 ± 1.6 years. The mean follow-up was 2.26 years (range 2.0-4.5). The major Cobb was corrected from 50.0° ± 7.2° to 14.2° ± 5.8° (Δ = 71.3% ± 12.1%; p < .0001). There was a significant improvement in BIDQ-S scores after surgery (1.64 ± 0.51 to 1.21 ± 0.38, p < .0001). BIDQ-S improvements were correlated with change in SRS self-image (p = .0055), activity (p = .0057), mental (p = .0018), and overall mean (p = .0007) domains. Preoperative, two-year postoperative, and Δ BIDQ-S score were not associated with major Cobb magnitude, truncal rotation, or Lenke curve type. Patients who reached SRS-22r minimal clinically important difference (MCID) in activity and self-image domains had worse preoperative BIDQ scores than those who did not reach MCID (activity 1.91 vs. 1.54 [1 = best, 5 = worst], p = .0099; self-image 2.08 vs. 1.51, p < .0001). Greater improvement in BIDQ-S was noted in patients who reached MCID in SRS-22 self-image than those who did not (Δ = 0.77 vs. 0.38, p = .0052). CONCLUSION: BIDQ-S is responsive to surgical correction of AIS. The BIDQ-S is a valuable clinical outcome tool to assess the psychosocial effects of scoliosis in adolescents augmenting existing outcome instruments.

Utilization of Drains and Association With Outcomes: A Population-Based Study Using National Data on Knee Arthroplasties.

INTRODUCTION: Although surgical drains have been used routinely in total knee arthroplasties (TKAs), results from several large trials have led to recommendations against their use. Because national data are lacking, we aimed at assessing utilization patterns of drains and perioperative outcomes in TKA procedures. METHODS: We included 1,130,124 TKA procedures from the national claims-based Premier Healthcare Database (2006 to 2016). Patients receiving a drain were compared with those who did not. Multivariable multilevel models measured associations between drain use and blood transfusions, postoperative infections, 30-day readmission, and length/cost of hospitalization. Odds ratios and 95% confidence intervals are reported. Propensity score analyses were performed to assess the robustness of results. RESULTS: Drain use decreased from 33.0% (n = 22,901 of 69,370) in 2006 to 15.6% (n = 19,418 of 124,440) in 2016 and was particularly higher in large (>500 beds; 27.1%) and nonteaching hospitals (26.9%). After adjustment for relevant covariates, the use of drains (compared with no use) was significantly associated with increases in particularly blood transfusions (odds ratio, 1.27; 95% confidence interval, 1.24 to 1.30 n = 138,306 total transfusions), whereas minimal effects were seen for other outcomes. Propensity score analyses confirmed these results. DISCUSSION: Although retrospective, the current study provides an important insight into real-world clinical practice regarding the use of drains. With current evidence not supporting their use in TKA, we found that national utilization is slowly decreasing. Moreover, because drain use is associated with negative outcomes, future studies should focus on drivers of their continued use. LEVEL OF EVIDENCE: Level III, therapeutic study.

Postoperative Spine Infection: Diagnosis and Management.

STUDY DESIGN: Review article. OBJECTIVES: A review of the literature on postoperative spinal infections, their diagnosis, and management. METHODS: A systematic computerized Medline literature search was performed using PubMed, Cochrane Database of Systematic Reviews, and EMBASE. The electronic databases were searched for publication dates from the last 10 years. The searches were performed from Medical Subject Headings (MeSH) used by the National Library of Medicine. Specifically, MeSH terms "spine," "infections," "management," and "diagnosis" were used. RESULTS: Currently, the gold standard for diagnosis of postoperative spine infection is positive deep wound culture. Many of the current radiologic and laboratory tests can assist with the initial diagnosis and monitoring treatment response. Currently erythrocyte sedimentation rate, C-reactive protein, computed tomography scan, and magnetic resonance imaging with and without contrast are used in combination to establish diagnosis. Management of postoperative spine infection involves thorough surgical debridement and targeted antibiotic therapy. CONCLUSIONS: Postoperative spine infection is a not uncommon complication following surgery that may have devastating consequences for a patient's short- and long-term health. A high index of suspicion is needed to make an early diagnosis.

Trends in Periprosthetic Hip Infection and Associated Costs: A Population-Based Study Assessing the Impact of Hospital Factors Using National Data.

BACKGROUND: Periprosthetic joint infection (PJI) is an important cost driver in hip arthroplasty revisions, thus necessitating careful trend monitoring. Recent national trend data are lacking; we therefore assessed national PJI burden, trends in prevalence, and hospitalization costs. METHODS: We extracted data on hip arthroplasty revisions from the National Inpatient Sample (2003-2013; n = 465,209). Trends in PJI prevalence and hospitalization costs were (1) assessed for the full cohort and (2) stratified by hospital teaching status, hospital bed size (≤299, 300-499, and ≥500 beds), and hospital region (Northeast, Midwest, South, and West). The Cochran-Armitage trend test (PJI prevalence) and linear regression (hospitalization costs) determined significance of trends. Trends were adjusted for patient's age, gender, insurance type, race, Deyo-Charlson comorbidities, obesity, length of stay, and hospital characteristics. RESULTS: Overall, PJI prevalence was 15.0% (n = 70,011); adjusted prevalence increased from 13.1% in 2003 to 16.4% in 2013 (P < .0001), while adjusted median PJI hospitalization costs increased from $28,240 in 2003 to $31,529 in 2013 (P < .0001). Rural hospitals had the lowest PJI burden (12.5%; n = 4,525), while urban and teaching hospitals had the highest PJI burden (16.4%; n = 40,297). The stratified analyses, particularly in large hospitals (>500 beds), showed that PJI prevalence increased from 13.0% (2003) to 17.4% (2013; a 33.8% increase; P < .0001). Similarly, PJI revision hospitalization costs increased from a median of $27,490 (2003) to $31,312 (2013; a 14% increase; P < .0001). CONCLUSION: The burden of PJI in hip arthroplasty revision is increasing and-while additional research is needed-there appears to be a particular shift of revision burden to larger hospitals with increasing costs.

Comparing the 5-Year Health State Utility Value of Cervical Disc Replacement and Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: Health utility analysis. OBJECTIVES: To determine the health state utility (HSU) of 1- and 2-level anterior cervical discectomy and fusion (ACDF) and cervical disc replacement (CDR). METHODS: Data from the Medtronic Prestige Cervical Disc investigational device exemption studies was used. Four groups were defined: 1-level ACDF, 1-level CDR, 2-level ACDF, and 2-level CDR. The 36-item Short Form Health Survey (SF-36) was collected at baseline, 12 months, 24 months, 36 months, and 60 months postoperatively and converted into utility scores for each time point. A repeated-measures 1-way analysis of variance (ANOVA) was used to detect differences among groups. Tukey's method for multiple comparisons was used to determine which means within the groups were statistically different (P < .05). RESULTS: We found a statistically significant difference in HSU among groups as determined by repeated-measures 1-way ANOVA (P = .0008). Post hoc analysis indicated that 1-level ACDF had a statistically lower utility score compared with 1- and 2-level CDR (P = .04 and P = .02, respectively). Similarly, 2-level ACDF had lower utility values compared with 2-level CDR (P = .010). One-level ACDF utility values were not different from 2-level ACDF values (P = .55). Similarly, 1-level CDR and 2-level CDR did not have different utility values (P = .67). CONCLUSIONS: Overall, CDR had higher health state utility scores for 1- and 2-level procedures at every time point. This study indicates that CDR results in a higher postoperative health utility state than ACDF, and may therefore be an effective alternative to ACDF for treating degenerative conditions of the cervical spine.

Investigating the 7-Year Cost-Effectiveness of Single-Level Cervical Disc Replacement Compared to Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: Cost-effectiveness analysis. OBJECTIVES: To determine the 7-year cost-effectiveness of cervical disc replacement (CDR) and anterior cervical discectomy and fusion (ACDF). METHODS: We analyzed 7-year Short Form-36 Health Survey data collected from the Prestige Cervical Disc investigational device exemption study (IDE). The SF-6D algorithm was used to convert this data into health state utilities. Costs were calculated from the payer perspective, and quality adjusted life years (QALYs) were used to represent effectiveness. A Markov transition-state model was used to evaluate the cost-effectiveness of single-level CDR versus ACDF, and a Monte Carlo simulation was performed to assess the probabilistic sensitivity of the model. RESULTS: CDR generated a 7-year cost of $172 989 compared to a 7-year cost of $143 714 for ACDF. CDR generated 4.53 QALYs compared to 3.85 QALYs generated by ACDF. The cost-effectiveness ratio of CDR was $38 247/QALY, while the cost-effectiveness ratio of ACDF was $37 325/QALY. The incremental cost-effectiveness ratio of CDR was $43 522/QALY, under the willingness to pay threshold of $50 000/QALY. Our probabilistic sensitivity analysis demonstrated CDR would be chosen 56% of the time based on 10 000 simulations. CONCLUSIONS: Single-level CDR and ACDF were both cost-effective strategies at 7 years for treating degenerative conditions of the cervical spine. Both the Markov simulation and the Monte Carlo simulation demonstrate CDR to be the more cost-effective strategy at 7 years. Continued analysis of IDE data should be performed to validate long-term cost-effectiveness of these treatment strategies.

The 5-year cost-effectiveness of two-level anterior cervical discectomy and fusion or cervical disc replacement: a Markov analysis.

BACKGROUND CONTEXT: Anterior cervical discectomy and fusion (ACDF) and cervical disc replacement (CDR) are both acceptable surgical options for the treatment of cervical myelopathy and radiculopathy. To date, there are limited economic analyses assessing the relative cost-effectiveness of two-level ACDF versus CDR. PURPOSE: The purpose of this study was to determine the 5-year cost-effectiveness of two-level ACDF versus CDR. STUDY DESIGN: The study design is a secondary analysis of prospectively collected data. PATIENT SAMPLE: Patients in the Prestige cervical disc investigational device exemption (IDE) study who underwent either a two-level CDR or a two-level ACDF were included in the study. OUTCOME MEASURES: The outcome measures were cost and quality-adjusted life years (QALYs). MATERIALS AND METHODS: A Markov state-transition model was used to evaluate data from the two-level Prestige cervical disc IDE study. Data from the 36-item Short Form Health Survey were converted into utilities using the short form (SF)-6D algorithm. Costs were calculated from the payer perspective. QALYs were used to represent effectiveness. A probabilistic sensitivity analysis (PSA) was performed using a Monte Carlo simulation. RESULTS: The base-case analysis, assuming a 40-year-old person who failed appropriate conservative care, generated a 5-year cost of $130,417 for CDR and $116,717 for ACDF. Cervical disc replacement and ACDF generated 3.45 and 3.23 QALYs, respectively. The incremental cost-effectiveness ratio (ICER) was calculated to be $62,337/QALY for CDR. The Monte Carlo simulation validated the base-case scenario. Cervical disc replacement had an average cost of $130,445 (confidence interval [CI]: $108,395-$152,761) with an average effectiveness of 3.46 (CI: 3.05-3.83). Anterior cervical discectomy and fusion had an average cost of $116,595 (CI: $95,439-$137,937) and an average effectiveness of 3.23 (CI: 2.84-3.59). The ICER was calculated at $62,133/QALY with respect to CDR. Using a $100,000/QALY willingness to pay (WTP), CDR is the more cost-effective strategy and would be selected 61.5% of the time by the simulation. CONCLUSIONS: Two-level CDR and ACDF are both cost-effective strategies at 5 years. Neither strategy was found to be more cost-effective with an ICER greater than the $50,000/QALY WTP threshold. The assumptions used in the analysis were strongly validated with the results of the PSA.

Acute vascular endothelial growth factor expression during hypertrophy is muscle phenotype specific and localizes as a striated pattern within fibres.

Skeletal muscle hypertrophy requires the co-ordinated expression of locally acting growth factors that promote myofibre growth and concurrent adaptive changes in the microvasculature. These studies tested the hypothesis that vascular endothelial growth factor (VEGF) and heparin-binding epidermal growth factor (HB-EGF) expression are upregulated during the early stages of compensatory muscle growth induced by chronic functional overload (FO). Bilateral FO of the plantaris and soleus muscles was induced for 3 or 7 days in the hindlimbs of adult female Sprague-Dawley rats (n = 5 per group) and compared with control (non-FO) rats. Relative muscle mass (in mg (kg body weight)(-1)) increased by 18 and 24% after 3 days and by 20 and 33% after 7 days in the plantaris and soleus muscles, respectively. No differences in HB-EGF mRNA or protein were observed in either muscle of FO rats relative to control muscles. The VEGF mRNA was similar in the soleus muscles of FO and control rats, whereas a significant elevation occurred at 3 and 7 days of FO in the plantaris muscle. However, VEGF protein expression after 3 days of FO exhibited a differential response; expression in the soleus muscle decreased 1.6-fold, whereas that in the plantaris muscle increased 1.8-fold compared with the control muscle. After 7 days of FO, VEGF protein remained elevated within the plantaris muscle, but returned to basal levels in the soleus. Robust basal HB-EGF and VEGF protein expression was consistently seen in control muscles. In all groups, immunohistochemistry for VEGF protein displayed a distinct striated expression pattern within myofibres, with considerably less labelling in extracellular spaces. Constitutive expression of HB-EGF and VEGF in control myofibres is consistent with housekeeping roles for these growth factors in skeletal muscle tissue. However, the specific patterns of VEGF expression in these muscles during FO may reflect the chronic changes in neural recruitment between muscles and the co-ordination of angiogenic and/or other hypertrophic responses.