A comparative cohort study of surgical approaches for adult spinal deformity at a minimum 2-year follow-up.

STUDY DESIGN: This study was a retrospective multi-center comparative cohort study. MATERIALS AND METHODS: A retrospective institutional database of operative adult spinal deformity patients was utilized. All fusions > 5 vertebral levels and including the sacrum/pelvis were eligible for inclusion. Revisions, 3 column osteotomies, and patients with < 2-year clinical follow-up were excluded. Patients were separated into 3 groups based on surgical approach: 1) posterior spinal fusion without interbody (PSF), 2) PSF with interbody (PSF-IB), and 3) anteroposterior (AP) fusion (anterior lumbar interbody fusion or lateral lumbar interbody fusion with posterior screw fixation). Intraoperative, radiographic, and clinical outcomes, as well as complications, were compared between groups with ANOVA and χ2 tests. RESULTS: One-hundred and thirty-eight patients were included for study (PSF, n = 37; PSF-IB, n = 44; AP, n = 57). Intraoperatively, estimated blood loss was similar between groups (p = 0.171). However, the AP group had longer operative times (547.5 min) compared to PSF (385.1) and PSF-IB (370.7) (p < 0.001). Additionally, fusion length was shorter in PSF-IB (11.4) compared to AP (13.6) and PSF (12.9) (p = 0.004). There were no differences between the groups in terms of change in alignment from preoperative to 2 years postoperative. There were no differences in clinical outcomes. While postoperative complications were largely similar between groups, operative complications were higher in the AP group (31.6%) compared to the PSF (5.4%) and PSF-IB (9.1) groups (p < 0.001). CONCLUSION: While there were differences in intraoperative outcomes (operative time and fusion length), there were no differences in postoperative clinical or radiographic outcomes. AP fusion was associated with a higher rate of operative complications.

Short Term Outcomes (Average Follow-Up of 2.4 Years) of a Constrained Acetabular Liner in Primary and Revision Total Hip Arthroplasty.

BACKGROUND: As instability continues to be a burden post-total hip arthroplasty (THA), there has been a controversial discussion on the ideal implant choice. We report the outcomes of a modern constrained acetabular liner (CAL) system in primary and revision THA at an average follow-up of 2.4 years. METHODS: We performed a retrospective study of all patients undergoing primary and revision hip arthroplasty and being implanted with the modern CAL system from 2013 to 2021. We identified 31 hips, of which 13 underwent primary THA and the remaining 18 underwent revision THA for instability. RESULTS: Of those implanted with CAL primarily, 3 had concomitant abductor tear repair and gluteus maximus transfer, 5 had Parkinson's disease, 2 had inclusion body myositis, 1 had amyotrophic lateral sclerosis, and the remaining two were over 94 years of age. All patients implanted with the CAL had active instability post-primary THA and underwent only liner and head exchange without revision of the acetabular or femoral components. At an average follow-up of 2.4 years (ranging from 9 months to 5 years and 4 months), we had 1 case (3.2%) of dislocation post-CAL implantation. None of the patients undergoing surgery with CAL for active instability had a redislocation. CONCLUSION: In conclusion, a CAL provides excellent stability in both primary THA in high-risk individuals and revision THA in cases of active instability. There were no dislocations when using a CAL to treat active instability post-THA.

Implant Malalignment may be a Risk Factor for Poor Patient-Reported Outcomes Measures (PROMs) Following Total Knee Arthroplasty (TKA).

BACKGROUND: Implant malalignment may be a risk factor for poor patient-reported outcomes measures (PROMs) following total knee arthroplasty (TKA). METHODS: Postoperative surveys were administered to assess PROMs regarding satisfaction, pain, and function in 262 patients who underwent surgery at 4 centers in the U.S. and U.K (average age, 67.2) at a mean 5.5 years after primary TKA. Postoperative distal femoral angle (DFA), proximal tibial angle (PTA), and posterior tibial slope angle (PSA) were radiographically measured, and outliers were recorded. PROMs were compared between patients with aligned versus malaligned knees using univariate analysis. RESULTS: Patients with DFA, PTA, and PSA outliers were more likely to experience similar or decreased activity levels postoperatively than patients with no alignment outliers, as were patients with 1 or 2 outliers of any kind (P < .05). Patients with DFA, PTA, and PSA outliers were significantly more likely to be dissatisfied with their ability to perform activities of daily living (ADLs), as were patients with 1 or 2 outliers of any kind (P < .05). Patients with DFA and PSA outliers were more likely to be dissatisfied with their degree of pain relief, as were patients with 2 outliers of any kind (P < .05). Finally, patients with DFA and PSA outliers, as well as those with 1 outlier of any kind, were more likely to be dissatisfied with their overall knee function (P < .05). CONCLUSION: DFA, PTA, and PSA outliers represent a significant risk factor for decreased satisfaction with activities of daily living(ADLs), pain relief, and knee function, as well as decreased activity levels. LEVEL OF EVIDENCE: Level III.

Infographics Are More Effective at Increasing Social Media Attention in Comparison With Original Research Articles: An Altmetrics-Based Analysis.

PURPOSE: To compare social media attention and citation rates between infographics (visual abstracts) and original research articles. METHODS: All infographics in 2019 from electronic versions of Arthroscopy were matched by topic to articles in the "Original Research" section of the journal in a 4:1 ratio within the same year. The primary outcome was the Altmetric Attention Score (AAS), a cumulative measure of social media attention from various platforms such as Twitter and Facebook. Secondary outcomes included citation rates, article characteristics, and number of shares on social media platforms. Independent t tests and χ2 analyses were used to compare primary and secondary outcomes between infographics and control articles. Multivariate linear regression analysis was performed to determine the association between article type and social media attention while controlling for bibliometric characteristics. RESULTS: A total of 60 matched research articles (n = 48, 80.0%) and infographics (n = 12, 20.0%) published in 2019 in Arthroscopy were included. The mean AAS among all infographics was 29.75 ± 32.84 (range, 3-118), whereas the mean AAS among all control research articles was 5.75 ± 8.90 (range, 0-41), representing a statistically significant difference (P < .001). Infographics had significantly more Twitter mentions (100% vs 70.8%, P < .001) and Facebook mentions (75% vs. 6.2%, P < .001) compared with original articles. Multivariate linear regression analysis demonstrated a statistically significant and positive association between AAS and article type, with an additional mean increase in the AAS of 33.7 (95% confidence interval 11.6-50.6; P = .003) for every infographic article compared with an original research article. The mean citation rate among all infographics was 2.4 ± 2.4 (range, 0-7), whereas the mean citation rate among all control research articles was 2.2 ± 4.0 (range, 0-27), which was not a significant difference (P = .69). CONCLUSIONS: Infographics resulted in significantly greater AAS and social media attention in comparison with original research articles of similar topics. We recommend the routine creation of infographics by journals to increase the social media attention that their research and chosen topics of interest receive. However, viewers of infographics should read them out of interest but turn their attention toward the original article or a source of more detailed information before making changes in clinical decision-making or practice, as they can be oversimplified. CLINICAL RELEVANCE: Infographics are an increasingly used by journals as a form of depicting research findings from select studies. By producing infographics, journals may increase the amount of social media attention received for a particular study or topic of interest.

Cost Comparison of Botulinum Toxin Injections Versus Surgical Treatment in Pediatric Patients With Cerebral Palsy: A Markov Model.

PURPOSE: The purpose of this study was to compare the cost-effectiveness of surgical release to botulinum toxin injections in the treatment of upper-extremity (UE) cerebral palsy (CP). METHODS: A Markov transition-state model was developed to assess the direct and indirect costs as well as accumulated quality-adjusted life-years associated with surgery (surgery group) and continuous botulinum toxin injections (botulinum group) for the treatment of UE CP in children aged 7 to 12 years. Direct medical costs were obtained from institutional billing departments. The number of parental missed workdays associated with each treatment was estimated and previously published regressions were used to calculate indirect costs associated with missed work. Total costs, cost-effectiveness, and incremental cost-effectiveness ratios were calculated. Incremental cost-effectiveness ratios and willingness to pay thresholds were used to make decisions regarding society's willingness to pay for the incremental cost of each treatment given the incremental benefit. RESULTS: The surgery group demonstrated lower direct, indirect, and total costs compared with the botulinum group. Direct costs were $29,250.50 for the surgery group and $50,596.00 for the botulinum group. Indirect costs were $9,467.46 for the surgery group and $44,428.60 for the botulinum group. Total costs were $38,717.96 for the surgery group and $95,024.60 for the botulinum group, a difference of $56,306.64. The incremental cost-effectiveness ratio was -$42,019.88, indicating that surgery is a less costly and more effective treatment and that botulinum injections fall outside the societal willingness to pay threshold. Excluding indirect costs associated with parental missed work during home occupational therapy did not have a significant impact on the model. CONCLUSIONS: Surgery is associated with lower direct, indirect, and total costs, as well as a greater number of accumulated quality-adjusted life-years. Surgery provides a greater benefit at a lower cost, which suggests that botulinum injections should be used sparingly in this population. Treatment with surgery could represent savings of $5.6 to $11.3 billion annually in the United States. TYPE OF STUDY/LEVEL OF EVIDENCE: Economic/Decision Analysis II.

Synovial Fluid Aspirates Diluted with Saline or Blood Reduce the Sensitivity of Traditional and Contemporary Synovial Fluid Biomarkers.

BACKGROUND: Recent criteria-based diagnostic tools to diagnose periprosthetic infection (PJI), such as the International Consensus Meeting (ICM) definition of PJI, are heavily reliant on synovial fluid laboratory results. Despite the importance of synovial fluid in PJI diagnosis, the effect of the quality of synovial fluid aspirate on testing results has not been studied. Our laboratory has established quality control parameters to identify synovial fluid aspirates that are highly diluted by saline or blood, which appear to degrade the diagnostic performance of synovial fluid laboratory tests. QUESTIONS/PURPOSES: (1) What proportion of synovial fluid aspirates analyzed at one laboratory are of poor quality (defined as having a red blood count > 1M cells/uL or an optical density at 280 nm < 0.324 or > 1.19)? (2) Does a poor-quality aspirate decrease the sensitivities of International Consensus Meeting-based scores and other synovial fluid biomarker tests in terms of their ability to anticipate a positive culture? METHODS: From January 2016 to July 2019, a total of 123,549 synovial fluid samples were submitted to one laboratory for the purpose of diagnostic testing. Of these, 14% (16,773 of 123,549) samples were excluded because they were from a site other than a hip, knee, or shoulder arthroplasty, and an additional 33% (35,660 of 106,776) were excluded due to insufficient requested tests, resulting in 58% (71,116 of 123,549) samples included in this study. Specimens diluted with extreme levels of saline or blood were identified (defined as having a red blood count >1 M cells/uL or an optical density at 280 nm < 0.324 or > 1.19) as poor-quality aspirates. The sensitivities of synovial fluid C-reactive protein, alpha defensin, neutrophil elastase, white blood cell count, polymorphonuclear cell percentage, and the 2018 ICM-based tool were assessed in good-quality versus poor-quality synovial fluid samples. To avoid bias from using these evaluated tests within the reference definition of PJI in this study, a positive culture resulting from the synovial fluid served as the reference diagnosis defining a control cohort of PJI-positive samples. Although the low false-positive rate of synovial fluid culture allows for the valid estimation of synovial fluid test sensitivity, the high false-negative rate of synovial fluid culture prevents the valid estimation of test specificity, which was not evaluated in this study. RESULTS: Of the samples analyzed, 8% (6025 of 71,116) were found to have poor quality, in that they were substantially compromised by saline and/or blood. The sensitivity of all tests to detect culture-positive synovial fluid was lower in poor-quality than in good-quality samples: 2018 International Consensus Meeting-based tool (83% [95% CI 80 to 86] versus 97% [95% CI 96 to 97]), synovial fluid C-reactive protein (65% [95% CI 61 to 69] versus 88% [95% CI 87 to 89]), alpha defensin (70% [95% CI 66 to 73] versus 93% [95% CI 93 to 94]), neutrophil elastase (80% [95% CI 77 to 83] versus 96% [95% CI 96 to 97]), synovial fluid white blood cell count (69% [95% CI 65 to 73] versus 93% [95% CI 93 to 94]), and the polymorphonuclear cell percentage (88% [95% CI 85 to 91] versus 95% [95% CI 94 to 95]), with all p < 0.001. CONCLUSIONS: When synovial fluid is substantially diluted with saline or blood, the biomarkers and cells being measured are also diluted, decreasing the sensitivity of laboratory testing. We recommend that future diagnostic studies exclude these samples because an artificial reduction in test sensitivity will be observed. CLINICAL RELEVANCE: Clinicians should avoid relying on negative synovial fluid testing to rule out PJI when the fluid submitted is substantially constituted of saline or blood. Further studies are necessary to understand the diagnostic utility, if any, of these diluted aspirate samples.

Prior Manipulation under Anesthesia is a Predictor of Contralateral Manipulation in Staged Bilateral Total Knee Arthroplasty.

BACKGROUND: There are many risk factors for arthrofibrosis and manipulation under anesthesia (MUA) following total knee arthroplasty (TKA). However, no study has elucidated whether a history of MUA increases the risk of contralateral MUA in patients undergoing staged bilateral TKA. METHODS: A retrospective review of an institutional database of TKAs was performed. All patients aged ≥18 years who underwent primary staged bilateral TKAs were screened for inclusion. Staged bilateral TKAs were viewed as 2 distinct events based on the temporal order in which they occurred: TKA#1 (occurred first) and TKA#2 (occurred second). Following TKA#1, patients were split into 2 groups: those who underwent MUA (Group MANIP) and those who did not (Group NO MANIP). The subsequent risk of undergoing MUA following TKA#2 was then assessed and compared between the 2 groups. Chi-squared tests were used for comparison. RESULTS: A total of 5,330 patients who underwent primary uncomplicated staged bilateral TKAs (10,660 knees) during the study period were identified. Overall, 2.1% of patients underwent MUA following TKA#1 and 1.9% of patients underwent MUA following TKA#2. In the MANIP group, 21.4% of patients underwent MUA following TKA#2, while only 1.5% underwent MUA in the NO MANIP group. This 14.3-fold increase in the risk of MUA in the MANIP group following TKA#2 was statistically significant (21.4% vs 1.5%, absolute risk reduction = 19.9%, relative risk reduction = 93.0%, P < .0001). CONCLUSION: Patients who undergo MUA during the first TKA of a staged bilateral TKA are 14.3 times more likely to undergo a subsequent MUA than those who did not undergo MUA following their first TKA.

False-Positive Automated Synovial Fluid White Blood Cell Counting Is a Concern for Both Hip and Knee Arthroplasty Aspirates.

BACKGROUND: Although false elevation of automated leukocyte (white blood cell [WBC]) counts has been described in the setting of hip corrosion, the more general correlation between manual and automated cell counts among synovial fluid aspirates from hip and knee arthroplasties has not been studied. METHODS: This retrospective review at one laboratory identified 8607 consecutive synovial fluid samples from arthroplasties and 812 from native knees, each with an automated WBC count > 3000 cells/µL and a corresponding paired reflex manual count. The correlation between automated and manual counts was evaluated, as was the rate of false-positive automated WBC counts. RESULTS: The correlation between automated WBC counts for native knees, total knee arthroplasties, and total hip arthroplasties was near-perfect, strong, and moderate, respectively. The false-positive rates for automated counts were 4.4%, 10.1%, and 34.3%, respectively (P < .0001). International Consensus Meeting scores and culture positivity demonstrated that manual counts, not automated counts, were correct. CONCLUSION: The presence of a hip or knee arthroplasty appears to substantially increase the risk of a false-positive automated synovial fluid WBC count. Clinicians evaluating an arthroplasty should exercise caution when interpreting positive automated WBC counts, and consider requesting a reflex manual count, to verify the accuracy of automated cell counting.

Comparison of Quadriceps-Sparing and Medial Parapatellar Approaches in Total Knee Arthroplasty: A Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: The quadriceps-sparing (QS) technique for total knee arthroplasty (TKA) was introduced to improve outcomes associated with the medial parapatellar (MP) approach. There is no clear consensus on what advantages, if any, QS provides. METHODS: We performed a meta-analysis of randomized controlled trials (RCTs) comparing the QS and MP techniques. PubMed, Ovid, and Scopus were assessed for relevant literature. Long-term (primary) outcomes and short-term (secondary) outcomes from 8 RCTs (579 TKAs) were analyzed using OpenMetaAnalyst (2016). RESULTS: The QS approach did not demonstrate clinically significant advantages, but was associated with statistically and clinically significant increases in the primary outcomes of femoral (odds ratio [OR] 4.92, P = .005), tibial (OR 4.34, P = .01), and mechanical axis outliers (OR 4.77, P = .004). Secondary outcome assessments demonstrated increased surgical (mean differences [MD] 19.54, P < .001) and tourniquet time (MD 23.30, P < .001) for QS. Although statistically significant advantages for QS were identified in Knee Society Function scores at 1.5-3 months (MD 2.31, P = .004) and 2 years (MD 1.86, P < .001), these were not clinically significant (fell below the 6-point minimal clinically important difference). CONCLUSION: The QS approach to TKA fails to demonstrate clinically significant advantages, but shows increased malalignment. This increased incidence of implant malalignment may predispose QS patients to early prosthesis failure. Because the QS approach may increases the risk of malalignment while providing no clear benefit compared to MP, we recommend against the routine use of the QS TKA approach.

Preoperative Patellofemoral Chondromalacia is Not a Contraindication for Fixed-Bearing Medial Unicompartmental Knee Arthroplasty.

BACKGROUND: Patellofemoral chondromalacia (PFCM) has historically been considered a contraindication for unicompartmental knee arthroplasty (UKA), but there is limited data assessing PFCM's impact on the results of fixed-bearing UKA. Our objective was to assess the impact of medial patellar and/or medial trochlear PFCM on overall and patellofemoral-specific 2-year outcomes after fixed-bearing medial UKA. METHODS: Intraoperative notes defined the presence and location of PFCM during fixed bearing medial UKA. Outcome measures included the New Knee Society Score (NKSS), Kneeling Ability Score (KAS) and Forgotten Joint Score (FJS-12). Thirty-one knees with PFCM (PFCM group), and 52 knees without PFCM (N-PFCM group) were included for analysis. Mann-Whitney U tests assessed the statistical significance of observed differences, and a Bonferroni correction was applied, adjusting threshold for significance to P = .005. RESULTS: At minimum follow-up of 2 years, no statistical differences were detected between the N-PFCM and PFCM groups in the postoperative NKSS (159 vs 157, P = .731), preoperative to postoperative NKSS change (P = .447), FJS-12 (70.5 vs 67.6, P = .471), or KAS (71% vs 65%, P = .217). Patients with isolated patellar chondromalacia (n = 13) demonstrated trends toward worse outcomes according to NKSS (147, P = .198), FJS-12 (58, P = .094), and KAS (46%, P = .018), but were statistically insignificant. No failures occurred in either group. CONCLUSION: Functional outcomes of fixed-bearing medial UKA are not adversely impacted by the presence of PFCM involving the medial patellar facet and/or medial or central trochlea. Further follow-up is needed to determine longer-term implications of fixed-bearing medial UKA in patients with PFCM.

Improvements in Sexual Activity After Total Knee Arthroplasty.

BACKGROUND: Sexual limitations in the setting of total knee arthroplasty (TKA) are poorly understood. METHODS: Surveys were designed to assess preoperative and postoperative sexual function, and limitations were retrospectively administered to 91 sexually active TKA patients at an average of 2.1 years (range, 0.5-4.0) after surgery. Preoperative and postoperative responses were compared using 1-tailed and 2-proportion z tests, with P < .05 as the threshold for significance. RESULTS: Before TKA, sexual quality and/or frequency was limited in 45% of patients because of their knee. Patients experienced an average 17.1 months (range, 0-60) of sexual limitations before surgery, resulting largely from pain (87%) and diminished range of motion or flexibility (44%). Fifty-five percent of patients reported the need to change their sexual positions to accommodate their knee, with 97% of these patients indicating the need to avoid kneeling during sex. Postoperatively, fewer patients had to adjust their sexual positions to accommodate their knee (55% vs 28%, P = .0005), and avoid bearing weight on the afflicted knee during sex (97% vs 79%, P = .0213). Patients resumed sexual activity after an average of 2.4 months (range, 0-18). Despite these general improvements, 25% of individuals had less sex in the first year after surgery. After 1 year of recovery, however, 60% indicated that they more easily engaged in sexual activity than in the previous year, with 84% of these patients experiencing less pain, and 30% experiencing greater mobility or range of motion. CONCLUSION: TKA does not eliminate sexual limitations, but it significantly decreases kneeling dysfunction and gives patients more liberty in selecting their sexual positions.

Radiographic Imaging in the Postanesthesia Care Unit is Unnecessary After Partial Knee Arthroplasty.

BACKGROUND: Obtaining routine radiographs in the postanesthesia care unit (PACU) after primary uncomplicated partial knee arthroplasty (PKA) is a common practice with unclear utility. The objective of this study is to determine the rate at which immediate postoperative radiographs identify an actionable problem after primary uncomplicated PKA and to determine the potential cost savings associated with foregoing the routine acquisition of these radiographs. METHODS: This was a retrospective review that assessed a consecutive series of 1366 primary uncomplicated PKAs (including 873 unicondylar knee arthroplasties, 313 patellofemoral arthroplasties, and 180 bicompartmental knee arthroplasties) performed between January 2008 and March 2016. Patients were separated into 2 cohorts: (1) those who had PACU radiographs (n = 1184), and (2) those who did not (n = 182). Operative reports and clinical follow-up records at the initial postoperative visit were reviewed to determine whether patients underwent early reoperation based on radiographic findings. The direct cost of PACU radiographs was estimated to be $33.63 based on average global Medicare payments from our institution. RESULTS: The rate of reoperation because of radiographic findings in the PACU or at the first follow-up was 0% (95% confidence interval: 0.0%-0.027%). The estimated direct radiographic expenditure for our 1366 patient cohort was nearly $46,000. CONCLUSION: Routine immediate postoperative PACU radiographs after primary uncomplicated PKA have limited clinical utility. Therefore, delaying postoperative radiographs until the initial follow-up office visit would result in substantial cost-savings without compromising the quality of patient care.

Stepping Toward Objective Outcomes: A Prospective Analysis of Step Count After Total Joint Arthroplasty.

BACKGROUND: Functional recovery monitoring after total hip arthroplasty (THA) and total knee arthroplasty (TKA) is often limited to surgeon-based assessment and patient self-reporting rather than objective measures. However, traditional outcomes may not reliably gauge return of function. The goal of this study was to evaluate and compare an objective measure of postoperative recovery, daily step-count, with patient self-reported outcomes. METHODS: Prospectively, 589 patients used a mobile step-tracking application to record daily steps. Steps were recorded for 4 weeks before surgery and 12 weeks, thereafter. Patient-reported lower extremity functional scale (LEFS) scores were recorded at 1, 6, and 12 weeks, postoperatively. LEFS scores were correlated to weekly median daily steps using the Spearman rank correlation coefficient. RESULTS: Preoperative median daily steps were 2682 and 1988 for patients undergoing THA and TKA, respectively. Steps for weeks 1, 6, and 12 were 214, 3,170, and 3884 after THA and 153, 1772, and 2311 after TKA, respectively. Step-count demonstrated a weakly positive correlation with LEFS scores. For week 1, the correlation was 0.27 and 0.29 for THA and TKA patients, respectively. For week 6, the correlation was 0.18 and 0.29 for THA and TKA patients, respectively. CONCLUSION: Physical function improved over the first 12 weeks as measured by both steps and patient-reported assessments. Postoperative steps weakly correlated with LEFS scores, suggesting patient-reported outcomes may provide only part of the story. Incorporating objective measures may be a valuable addition to the surgeon's armamentarium for monitoring patient recovery.

The Alpha-defensin Test for Periprosthetic Joint Infections Is Not Affected by Prior Antibiotic Administration.

BACKGROUND: Previous studies have demonstrated that the administration of antibiotics to patients before performing diagnostic testing for periprosthetic joint infection (PJI) can interfere with the accuracy of test results. Although a single-institution study has suggested that alpha-defensin maintains its concentration and sensitivity even after antibiotic treatment, this has not yet been demonstrated in a larger multiinstitutional study. QUESTIONS/PURPOSES: (1) For the evaluation of PJI, is prior antibiotic administration associated with decreased alpha-defensin levels? (2) When prior antibiotics are given, is alpha-defensin a better screening test for PJI than the traditional tests (erythrocyte sedimentation rate [ESR], C-reactive protein [CRP], fluid white blood cells, fluid polymorphonuclear cells [PMNs], and fluid culture)? METHODS: This retrospective study included data from 106 hip and knee arthroplasties with Musculoskeletal Infection Society-defined PJI from four centers. Of the 106 patients in this study, 30 (28%) were treated with antibiotics for PJI before diagnostic workup (ABX group), and 76 (72%) were not treated before the diagnostic workup (NO-ABX group). There were no differences in age, sex, joint, culture-negative rate, or bacteriology between groups. The patients in the ABX group had antibiotics initiated by physicians who commenced care before assessment for PJI by the treating surgeon's service. We compared the alpha-defensin levels and sensitivity between the ABX and NO-ABX groups. Additionally, the sensitivity of the alpha-defensin test was compared to that of traditional tests for PJI among patients on antibiotics. RESULTS: The administration of antibiotics before performing the alpha-defensin test for PJI was not associated with a decreased median alpha-defensin level (ABX group, median 4.2 [range, 1.79-12.8 S/CO] versus NO-ABX, median 4.9 [range, 0.5-16.8 S/CO], difference of medians: 0.68 S/CO [95% confidence interval {CI}, -0.98 to 1.26], p = 0.451). Furthermore, the alpha-defensin test had a higher sensitivity (100%; 95% CI, 88.4%-100.0%) in diagnosing PJI among patients on antibiotics when compared with the ESR (69.0% [95% CI, 49.17%-84.72%], p = 0.001), the CRP (79.3% [95% CI, 60.3%-92.0%], p = 0.009), the fluid PMN% (79.3% [95% CI, 60.3%-92.0%), p = 0.009), and fluid culture (70.0% [95% CI, 50.6%-85.3%], p = 0.001). CONCLUSIONS: The alpha-defensin test maintains its concentration and sensitivity for PJI even in the setting of antibiotic administration. Furthermore, among patients with PJI on antibiotics, the alpha-defensin tests demonstrated a higher sensitivity in detecting PJI when compared with the ESR, CRP, fluid PMN%, and fluid culture. The high sensitivity of the alpha-defensin test, even in the setting of prior antibiotic treatment, provides excellent utility as a screening test for PJI. LEVEL OF EVIDENCE: Level III, diagnostic study.

Significant Functional Improvement at 2 Years After Isolated Patellofemoral Arthroplasty With an Onlay Trochlear Implant, But Low Mental Health Scores Predispose to Dissatisfaction.

INTRODUCTION: We reviewed the clinical and radiographic outcomes of a consecutive series of patients who underwent patellofemoral arthroplasty (PFA) using a modern onlay-style trochlear design and all-polyethylene patellar component. An additional goal of the study was to elucidate, for the first time, the extent to which patients were satisfied with their implant and whether expectations were met after undergoing PFA. METHODS AND MATERIALS: We identified a consecutive series of 70 knees (53 patients) treated with primary isolated PFA between October 2007 and May 2012. For our clinical outcomes analysis, we included patients with a minimum follow-up of 2 years and available preoperative original Knee Society scores. RESULTS: At an average 4.9 years of follow-up, the mean range of motion and Knee Society Knee and Function scores improved significantly, and less than 4% of patients required revision arthroplasty. There was no radiographic evidence of component loosening or wear. Despite these improvements, new Knee Society scores indicated that fewer than two-thirds of patients were satisfied or had their expectations met. Dissatisfied patients and those whose expectations were not met had significantly lower Mental Health scores according to the Short Form-36 following PFA. CONCLUSIONS: Despite the clinical and radiographic success of this implant, patient satisfaction remained low, which may be partially explained by poor mental health.

Return to Play After Injuries to the Cervical Spine.

Return to play (RTP) after sports-related traumatic injuries to the cervical spine is important for athletes and teams, especially at the elite level. While early RTP may be incentivized for athletes and organizations, treating clinicians must have a thorough understanding of cervical spine injuries, treatments, and RTP guidelines to make safe recommendations. In general, patients can RTP when asymptomatic from prior injury with no neurological deficits and a full, painless, active range of motion of the neck. However, injury diagnosis, injury symptoms and severity, history of cervical spine injuries, anatomic variants/anomalies, history of treatment/surgery, and any ongoing or persistent symptoms may modify RTP recommendations. In the current review, we summarize the common cervical spine injuries associated with contact sports and the available guidelines for RTP. It is important to note, however, that despite these guidelines, there is little consensus among treating physicians regarding these recommendations. Therefore, clinical judgment should be used to ensure conservative decisions are made and patient safety is maintained.

Hounsfield units and vertebral bone quality score for predicting mechanical complications after adult spinal deformity surgery: a systematic review and meta-analysis.

The purpose of this systematic review and meta-analysis is to assess existing literature and determine the association between the Hounsfield unit (HU) value and the vertebral body quality (VBQ) score with mechanical complications (MCs) after adult spinal deformity (ASD) surgery. Although bone quality is considered an increasingly important factor for MCs after ASD surgery, the utility of the HU value assessed by computed tomography and the VBQ score assessed by magnetic resonance imaging remains unknown. A systematic review of PubMed, Embase, and Cochrane Library databases was performed to find studies evaluating the association between the HU value and the VBQ score with MCs after ASD surgery. In the subsequent meta-analysis, MC outcomes were combined using a random-effects model, and the standardized mean difference and 95% confidence interval were calculated. The final analysis included a total of 20 studies. Nineteen studies reported HU values, and two studies reported VBQ scores. Proximal junctional kyphosis/failure (PJK/PJF) was reported as the MC in 16 studies, whereas other MCs were included in 6 studies. Six studies with a pool of 506 patients with ASD revealed that preoperative HU values at the upper instrumented vertebra (UIV) and UIV+1 were significantly lower in patients with PJK/PJF (standardized mean difference, -0.74; 95% confidence interval, -1.09 to -0.40). Three studies suggested an cutoff HU value of approximately ≤120, yielding a pooled sensitivity of 0.77, specificity of 0.67, and diagnostic odds ratio of 7.01. However, two studies reported conflicting results on the relationship between the VBQ score and PJK/PJF. Low HU values predicted the risk of certain MCs, particularly PJK/PJF, after ASD surgery. An HU value of <120 should alert surgeons to be cautious about the postoperative occurrence of PJK/PJF. Future studies are needed to validate the cutoff HU value and evaluate the utility of the VBQ score.

The Impact of Endplate Coverage on Heterotopic Ossification Following Cervical Disc Replacement: A Systematic Review and Meta Analysis.

STUDY DESIGN: Systematic review and meta-analysis. OBJECTIVE: Describe the impact of endplate coverage on HO in cervical disc replacement (CDR). SUMMARY OF BACKGROUND DATA: CDR is a motion-sparing alternative to anterior cervical discectomy and fusion. However, the high prevalence of heterotopic ossification threatens to diminish range of motion and limit this benefit associated with CDR. MATERIALS AND METHODS: A systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. EMBASE and PubMed databases were queried. Results were deduplicated and screened. Relevant studies were included. All metrics that were reported in ≥3 studies were aggregated for analysis. SPSS was used to perform the meta-analysis. RESULTS: A total of 10 studies were included in the systematic review. Endplate coverage was assessed using a wide variety of measurements, including anteroposterior implant depth (ID), endplate depth (ED), exposed endplate depth (EED), implant depth to endplate depth ratio (ID:ED), EED to ED ratio (EED:ED), implant width (IW) to endplate width (EW) ratio (IW:EW), and the implant area (IA) to endplate area (EA) ratio (IA:EA). No evidence has linked ID (three studies) to HO. Mixed evidence has linked ID:ED (3/5) and IW:ED (1/2) to HO. All available evidence has linked ED (2), EED (4), EED:ED (2), and IA:EA (1) to HO. In our meta-analysis, ID was not found to be a significant risk factor for HO. However, EED and ID:ED were found to be significant risk factors for HO formation. CONCLUSIONS: Exposed endplate, especially as assessed by EED and ID:ED, is a significant risk factor for HO. Surgeons should focus on preoperative planning and intraoperative implant selection to maximize endplate coverage. While optimizing technique and implant selection is crucial, improved implant design may also be necessary to ensure that appropriate implant-endplate footprint matching is possible across the anatomic spectrum.

Analysis of 1027 Adverse Events Reports for Interspinous Process Devices From the US Food and Drug Administration Manufacturer and User Facility Device Experience Database.

BACKGROUND: Interspinous process devices (IPDs) introduce a new class of complications to surgical decompression without fusion: hardware-related complications. The purpose of this study was to describe the adverse events associated with IPDs. STUDY DESIGN: This was a retrospective review of the Food and Drug Administration Manufacturer and User Facility Device Experience database. METHODS: The database was queried from its inception to November 2022 for reports associated with "Prosthesis, Spinous Process Spacer/Plate." Entries were categorized by event type, patient impact, and interventions. RESULTS: A total of 943 surgery-related adverse events were identified. The most common intraoperative events were implant malfunctions (39.7%, n = 374) and fractures (2.2%, n = 21). The most common postoperative events were persistent pain (26.6%, n = 251), implant migration (19.1%, n = 180), and fracture (6.8%, n = 64). The most common resultant outcome of an adverse event was the need for revision surgery (48.8%, n = 460). The need for revision surgery was common in patients who experienced fracture (47.1%), implant migration (84.5%), infection (76.7%), and neurological complications (76.9%). Implant migration, fracture, and implant malfunction, 3 complications that are unique to decompression with an IPD as compared with traditional laminectomy, accounted for 45.9% of revisions (211/460), and revision was required in 33.0% of cases where 1 of these complications was reported (211/640). Implant malfunction made up 21.2% of Coflex complications, 47.3% of Superion complications, and 5.2% of X-Stop complications. CONCLUSIONS: The most common adverse events were implant malfunction, inadequate efficacy, implant migration, and fracture. Concerningly, these complications require revision surgery in one-third of cases when they occur. Implant-specific assessments demonstrate a high prevalence of implant malfunctions for the Coflex and Superion implants. CLINICAL RELEVANCE: Interspinous process devices introduce a new class of complications to isolated spinal decompression surgery: implant-related complications. These complications occur both intraoperatively and postoperatively, and they frequently necessitate revision surgery.

Perioperative Infection Prophylaxis With Vancomycin is a Significant Risk Factor for Deep Surgical Site Infection in Spine Surgery.

STUDY DESIGN: Retrospective cohort. OBJECTIVE: The purpose of this study was to compare the efficacy of cefazolin versus vancomycin for perioperative infection prophylaxis. SUMMARY OF BACKGROUND DATA: The relative efficacy of cefazolin alternatives for perioperative infection prophylaxis is poorly understood. MATERIALS AND METHODS: This study was a single-center multisurgeon retrospective review of all patients undergoing primary spine surgery from an institutional registry. Postoperative infection was defined by the combination of three criteria: irrigation and debridement within 3 months of the index procedure, clinical suspicion for infection, and positive intraoperative cultures. Microbiology records for all infections were reviewed to assess the infectious organism and organism susceptibilities. Univariate and multivariate analyses were performed. RESULTS: A total of 10,122 patients met inclusion criteria. The overall incidence of infection was 0.78%, with an incidence of 0.73% in patients who received cefazolin and 2.03% in patients who received vancomycin (OR: 2.83, 95% CI: 1.35-5.91, P= 0.004). Use of IV vancomycin (OR: 2.83, 95% CI: 1.35-5.91, P =0.006), BMI (MD: 1.56, 95% CI: 0.32-2.79, P =0.014), presence of a fusion (OR: 1.62, 95% CI: 1.04-2.52, P =0.033), and operative time (MD: 42.04, 95% CI: 16.88-67.21, P =0.001) were significant risk factors in the univariate analysis. In the multivariate analysis, only noncefazolin antibiotics (OR: 2.48, 95% CI: 1.18-5.22, P =0.017) and BMI (MD: 1.56, 95% CI: 0.32-2.79, P =0.026) remained significant independent risk factors. Neither IV antibiotic regimen nor topical vancomycin significantly impacted Gram type, organism type, or antibiotic resistance ( P >0.05). The most common reason for antibiosis with vancomycin was a penicillin allergy (75.0%). CONCLUSIONS: Prophylactic antibiosis with IV vancomycin leads to a 2.5 times higher risk of infection compared with IV cefazolin in primary spine surgery. We recommend the routine use of IV cefazolin for infection prophylaxis, and caution against the elective use of alternative regimens like IV vancomycin unless clinically warranted.