More anterior bone loss in middle vertebra after contiguous two-segment cervical disc arthroplasty.

BACKGROUND: Contiguous two-segment cervical disc arthroplasty (CDA) is safe and effective, while post-operative radiographic change is poorly understood. We aimed to clarify the morphological change of the three vertebral bodies operated on. METHODS: Patients admitted between 2015 and 2020 underwent contiguous two-level Prestige LP CDA were included. The follow-up was divided into immediate post-operation (≤ 1 week), early (≤ 6 months), and last follow-up (≥ 12 months). Clinical outcomes were measured by Japanese Orthopedic Association (JOA) score, visual analogue score (VAS), and neck disability index (NDI). Radiographic parameters on lateral radiographs included sagittal area, anterior-posterior diameters (superior, inferior endplate length, and waist length), and anterior and posterior heights. Sagittal parameters included disc angle, Cobb angle, range of motion, T1 slope, and C2-C7 sagittal vertical axis. Heterotopic ossification (HO) and anterior bone loss (ABL) were recorded. RESULTS: 78 patients were included. Clinical outcomes significantly improved. Of the three operation-related vertebrae, only middle vertebra decreased significantly in sagittal area at early follow-up. The four endplates that directly meet implants experienced significant early loss in length. Sagittal parameters were kept within an acceptable range. Both segments had a higher class of HO at last follow-up. More ABL happened to middle vertebra. The incidence and degree of ABL were higher for the endplates on middle vertebra only at early follow-up. CONCLUSION: Our findings indicated that after contiguous two-segment CDA, middle vertebra had a distinguishing morphological changing pattern that could be due to ABL, which deserves careful consideration before and during surgery.

The application of topical antibiotics for the prevention of infections in primary joint arthroplasty. An umbrella review of systematic reviews and meta-analysis.

This umbrella review aim to explore the effect of topical antibiotics in infection prevention after primary joint arthroplasty, and provide a specific theoretical basis for clinical treatment. The review process was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched PubMed, EMBASE, Medline, and the Cochrane Library on infection prevention by topical antibiotics from inception to 10 April 2023. The two researchers individually and strictly screened the literature according to the inclusion and exclusion criteria, performed the literature quality evaluation and data extraction, and used Stata 17 for data analysis. This study included six studies with one systematic review and five meta-analyses. The pooled analysis showed that topical antibiotic administration effectively reduced the incidence of overall infection and periprosthetic joint infection. However, it does not reduce the risk of superficial infection. Besides, the topic of antibiotics significantly increases the incidence of other sterile complications of the incision. According to the current evidence, topical application of antibiotics can reduce the incidence of overall infection and periprosthetic joint infection after primary joint arthroplasty. Although it increases the incidence of complications such as delayed healing of incisions, the pros and cons should be weighed in clinical decision making. However, they should not be discarded due to side effects.

Basal thumb arthritis surgery: complications and its management.

The management of complications after surgery for basal thumb arthritis is sometimes challenging, and there are no clear recommendations on how to evaluate and manage patients with residual symptoms. The aim of the present article was to review the most common complications after surgery for basal thumb arthritis, with an emphasis on resection arthroplasty, joint replacement and joint fusion. In addition, possible management strategies for the different types of complications will be highlighted.

Systematic review and meta-analysis of single-stage vs two-stage revision for periprosthetic joint infection: a call for a prospective randomized trial.

BACKGROUND: Periprosthetic joint infection (PJI) is a severe complication of joint arthroplasty that causes significant pain and economic loss. This study aimed to determine whether the current evidence supports single-stage revision for PJI based on reinfection and reoperation rates. METHODS: We searched the PubMed, EBSCO, Medline, and Cochrane Library databases from inception to 30 May 2023 to identify studies that compared single-stage revision and two-stage revision for PJI. Data on reinfection and reoperation rates were pooled. RESULTS: This meta-analysis included a total of 40 studies with 8711 patients. Overall, there was no significant difference between single- and two-stage revision regarding the postoperative reinfection rate and reoperation rate. Subgroup analysis by surgery period and different surgical sites revealed no difference between the two groups in the reinfection and reoperation rates. CONCLUSIONS: Based on the available evidence, our study did not identify a significant difference in reinfection and reoperation rates between single- and two-stage revision for PJI. Given the limitations in inclusion/exclusion criteria and the observed heterogeneity, we acknowledge the complexity of drawing strong conclusions. Therefore, we suggest that the choice between single- and two-stage revision should be carefully considered on an individual basis, taking into account patient-specific factors and further research developments.

Correlation of Patient-Reported Preoperative Narcotic Use and Postoperative Requirements in Total Joint Arthroplasty.

Preoperative narcotic use is associated with diminished outcomes and increased complications in patients undergoing primary total joint arthroplasty (TJA). The goal of this study was to compare self-reported and state database identified preoperative narcotic use and correlate it with perioperative narcotic requirements in patients undergoing primary arthroplasty. A total of 788 patients undergoing unilateral TJA from a single institution were examined using self-reported preoperative narcotic use questionnaires and were verified using the Massachusetts Prescriber Awareness Tool (MassPAT). Demographic data, perioperative morphine milligram equivalents, and postdischarge refills were recorded and analyzed. Of the total population, 16.4% of patients undergoing TJA had verified MassPAT narcotics prescriptions preoperatively. Of these patients, 55% accurately reported use to their surgeon. Patients with verified MassPAT narcotic prescriptions required more morphine milligram equivalents than patients without MassPAT prescriptions, regardless of their preoperative self-report at all time points in the study. Patients who accurately reported use required more narcotics than those who did not. Patients with MassPAT prescriptions required more postdischarge refills than patients without MassPAT prescriptions. These data suggest that state-run narcotics databases may be more useful than self-reports for identifying which patients may require more opioids both immediately postoperatively and after hospital discharge. [Orthopedics. 2024;47(1):34-39.].

Should patient eligibility criteria for cervical disc arthroplasty (CDA) be expanded? A retrospective cohort analysis of relatively contraindicated patients undergoing CDA.

BACKGROUND CONTEXT: Cervical disc arthroplasty (CDA) is a safe and effective alternative to anterior cervical discectomy and fusion (ACDF) in the treatment of various degenerative pathologies with advantages of motion preservation and lower rates of adjacent segment degeneration (ASD). Absolute contraindications for CDA have been well outlined in order to prevent adverse outcomes in patients. However, in cases of patients with relative contraindications (kyphotic deformity, prior cervical surgery, etc.), there remains controversy. There is minimal literature evaluating long-term outcomes in this patient population. PURPOSE: To compare long-term clinical and functional outcomes of CDA in typical patients versus those with relative contraindications. DESIGN: Retrospective cohort review. PATIENT SAMPLE: Eighty-nine patients were included in the study: 55 (no contraindications) in Group 1 and 34 (relatively contraindicated) in Group 2 and 26 (preoperative segmental kyphosis) in Group 3. OUTCOME MEASURES: (1) Patient demographics; (2) perioperative data; (3) rates of complications and revisions; (5) visual analogue scale (VAS), and neck disability index (NDI) scores. METHODS: Patients were placed in the relatively contraindicated cohort if they possessed at least one of the following: (1) segmental kyphosis of 5° to 10°, (2) significant loss of disc height (between 50% and 75% of initial measurements or 1.5-3mm), (3) bridging osteophytes, and (4) prior cervical spine surgery based on preoperative cervical radiographs. The other cohort included patients without any relative contraindication who underwent CDA over the same time frame. Additionally, a subgroup analysis was used to compare those without any contraindications to those with only preoperative segmental kyphosis. Patients were included in this study if they met the following criteria: over 18 years of age, minimum follow-up of 24 months, and availability of complete medical records. Patient demographics, levels operated on, and perioperative outcomes were assessed between the two groups. Revision and complication rates were recorded. Functional outcomes scores were compared using VAS and NDI scores at 6-months, 12-months and final follow-up. RESULTS: Mean follow-up was 40.8 months in Group 1 and 38.3 months in Group 2 (p=.569). Complication rates were 21.8% in Group 1 and 26.4% in Group 2 (p=.615). Complication rates in a comparison between Groups 1 and 3 were statistically insignificant (p=.383). The most common complication was transient approach-related postoperative dysphagia (Group 1: 20% vs Group 2: 23.5%, p=.693). No significant differences were observed in the rates of transient dysphonia (Group 1: 0.0% vs Group 2: 2.9%, p=.201), adjacent segment degeneration (ASD) (Group 1: 1.8% vs Group 2: 0.0%, p=.429), infection (Group 1: 1.8% vs Group 2: 2.9%, p=.712), heterotopic ossification (Group 1: 49.1% vs Group 2: 50.0%, p=.934) or spontaneous fusion (Group 1: 1.8% vs Group 2: 2.9%, p=.728). No revision surgeries were observed in either cohort. All three groups demonstrated significant improvements in their VAS and NDI scores compared with preoperative measurements (p<.001), but no significant differences were found in the degree of improvement between groups at any point in time. CONCLUSIONS: Our study found no significant differences in clinical and functional outcomes between patients undergoing 1- and 2-level CDA with relative contraindications versus typical patients. These findings suggest that patient eligibility criteria for CDA may warrant expansion. However, future prospective studies over a longer period of follow-up are necessary to corroborate our results.

Predictors of Failure to Achieve Planned Same-Day Discharge after Primary Total Joint Arthroplasty: a Multivariable Analysis of Perioperative Risk Factors.

INTRODUCTION: Failure to achieve planned same-day discharge (SDD) primary total joint arthroplasty (TJA) occurs in as many as 7% to 49% of patients in the United States. This study evaluated the association between 43 perioperative risk factors and SDD failure rates. METHODS: A retrospective analysis of prospectively collected data from 466 primary TJAs with planned SDD to home was performed. Surgeries were performed at an academic tertiary care center comprising a hospital facility and a stand-alone ambulatory surgery center (ASC) on the same campus. Factors associated with failed SDD were identified using a multivariable analysis. RESULTS: Only one of 316 (0.3%) patients who underwent surgery in the ASC failed planned SDD ( P < 0.001) compared with 33.3% of 150 patients who underwent surgery in the hospital. The ASC failure was because of pain that interfered with physical therapy. Sixty-two percent (n = 31) of hospital failures were attributed to medical complications, 24% (n = 12) to physical therapy clearance, 8% (n = 4) to not being seen by internal medicine or therapy on the day of surgery, and 6% (n = 3) to unknown causes. Failure was increased in patients with preoperative anemia ( P = 0.003), nonwhite patients ( P = 0.002), patients taking depression/anxiety medication ( P = 0.015), and for every 10-morphine milligram equivalent increase in opioids consumed per hour in the postacute care unit ( P = 0.030). DISCUSSION: Risk stratification methods used to allocate patients to ASC versus hospital outpatient TJA surgery predicted SDD success. Most failures were secondary to medical causes. The findings of this study may be used to improve perioperative protocols enabling the safe planning and selection of patients for SDD pathways.

A review of wear debris in thumb base joint implants.

AIM: Polymers and metals, such as polyethylene (PE) and cobalt chrome (CoCr), are common materials used in thumb-based joint implants, also known as CMC (Carpometacarpal) arthroplasty. The purpose of this review was to investigate the reported failure modes related to wear debris from these type of materials in CMC implants. The impact of wear debris on clinical outcomes of CMC implants was also examined. Potential adverse wear conditions and inflammatory particle characteristics were also considered. METHOD: A literature search was performed using PRISMA guidelines and 55 studies were reviewed including 49 cohort studies and 6 case studies. Of the 55 studies, 38/55 (69%) focused on metal-on-polyethylene devices, followed by metal-on-metal (35%), and metal-on-bone (4%). RESULTS: The summarized data was used to determine the frequency of failure modes potentially related to wear debris from metals and/or polymers. The most commonly reported incidents potentially relating to debris were implant loosening (7.1%), osteolysis (1.2%) and metallosis (0.6%). Interestingly the reported mechanisms behind osteolysis and loosening greatly varied. Inflammatory reactions, while rare, were generally attributed to metallic debris from metal-on-metal devices. Mechanisms of adverse wear conditions included implant malpositioning, over-tensioning, high loading for active patients, third-body debris, and polyethylene wear-through. No specific examination of debris particle characterization was found, pointing to a gap in the literature. CONCLUSION: This review underscores the types of failure modes associated with wear debris in CMC implants. It was found that failure rates and adverse wear conditions of CMC implants of any design are low and the exact relationship between wear debris and implant incidences, such as osteolysis and loosening remains uncertain. The authors note that further research and specific characterization is required to understand the relationship between debris and implant failure.

Periprosthetic Infection in Patients With Multiple Joint Arthroplasties.

The number of total joint arthroplasties performed in the United States is increasing every year. Owing to the aging population and excellent long-term prosthesis survival, 45% of patients who undergo joint arthroplasty will receive two or more joint arthroplasties during their lifetimes. Periprosthetic joint infection (PJI) is among the most common complications after arthroplasty. Evaluation and treatment of PJI in patients with multiple joint arthroplasties is challenging, and no consensus exists for the optimal management. Multiple PJI can occur simultaneously, synchronous, or separated by extended time, metachronous. Patient risk factors for both scenarios have been reported and may guide evaluation and long-term management. Whether to perform joint aspiration for asymptomatic prosthesis in the presence of suspected PJI in patients with multiple joint arthroplasties is controversial. Furthermore, no consensus exists regarding whether patients who have multiple joint arthroplasties and develop PJI in a single joint should be considered for prolonged antibiotic prophylaxis to reduce the risk of future infections. Finally, the optimal treatment of synchronous joint infections whether by débridement, antibiotics and implant retention, and one-stage or two-stage revision has not been defined. This review will summarize the best information available and provide pragmatic management strategies.

Humeral Head Reconstruction of Reverse Hill-Sachs Lesions.

Compared with anterior instability, posterior shoulder dislocations are a rare entity and are often missed at presentation. A concomitant anteromedial impression fracture of the humeral head, or a reverse Hill-Sachs lesion, is commonly present with these dislocations and is more pronounced with a longer timeline to reduction. Treatment of these defects ranges from nonsurgical treatment to soft-tissue procedures, bony reconstruction, and arthroplasty. Management may be dictated by various factors, such as patient demands, defect size and location, concomitant injuries, and underlying etiology. Small reverse Hill-Sachs defects without engagement can generally be treated nonsurgically or with benign neglect, whereas larger defects (>20%) often require surgery. The most reported surgical techniques are the (arthroscopic) McLaughlin and modified McLaughlin procedure, disimpaction and bone grafting, or reconstruction of the defect with autograft or with fresh (or fresh-frozen) osteochondral allograft. Finally, arthroplasty is generally required for large defects, where more than 45% to 50% of the articular cartilage is involved. Overall, reported outcomes generally reflect patient satisfaction for most patients, with a low incidence of secondary instability or posttraumatic arthritis, although better results are achieved when recognizing and treating these injuries in the more acute setting.

Infection in Shoulder Arthroplasty: Prevention, Diagnosis, and Treatment.

Prosthetic joint infection is a devastating complication following shoulder arthroplasty that can lead to pain, poor function, and poor quality of life. With the increasing number of shoulder arthroplasties performed annually, recognition of prosthetic infection and treatment is necessary. The skin surrounding the shoulder has a unique microbiome, and Cutibacterium acnes is the most commonly encountered bacteria causing prosthetic joint infection. C acnes is a low-virulence organism that resides in the subcutaneous layer of the skin. As a result, the clinical presentation is typically less obvious than prosthetic infections seen in other joints such as the hip and knee. Therefore, diagnosis is not always straightforward, and optimal treatment strategy is unclear. Guidance on prevention, diagnosis, and treatment of shoulder prosthetic joint infection with special emphasis on the consensus definition established at the 2018 International Consensus Meeting is provided.

Neutrophil to Lymphocyte Ratio as an Indicator of Periprosthetic Joint Infection: A Retrospective Cohort Study.

INTRODUCTION: Periprosthetic joint infection (PJI) after total joint arthroplasty (TJA) is a serious complication posing notable clinical implications for patients and substantial economic burdens. Neutrophil to lymphocyte ratio (NLR) is an emerging biomarker of inflammation, which may better predict PJI. The objective of this review was to evaluate NLR changes in patients with confirmed PJI, to compare NLR between an aseptic revision and a revision for PJI, and to establish whether an NLR of 2.45 is an appropriate cutoff for predicting infection. METHODS: A retrospective review of patients who underwent revision TJA for PJI at a single center between January 1, 2005, and December 31, 2018, was performed and compared with an aseptic cohort who underwent aseptic revision TJA. NLR was calculated from complete blood counts performed at index surgery and at the time of revision surgery. Receiver operating characteristic curves were analyzed, along with sensitivity, specificity, and positive and negative likelihood ratios. RESULTS: There were 89 patients included in each cohort. Mean NLR in patients who underwent revision for PJI was 2.85 (± 1.27) at the time of index surgery and 6.89 (± 6.64) at the time of revision surgery ( P = 0.017). Mean NLR in patients undergoing revision for PJI (6.89) was significantly higher than aseptic revisions (3.17; P < 0.001). DISCUSSION: In patients who underwent revision surgery for PJI, NLR was markedly elevated at time of revision compared with the time of index surgery. Because it is a cost-effective and readily available test, these findings suggest that NLR may be a useful triage test in the diagnosis of PJI. LEVEL OF EVIDENCE: Level III Diagnostic Study.

The Risk of Early Postoperative Complications Associated With Preoperative Immunosuppression in Patients Undergoing Total Elbow Arthroplasty.

PURPOSE: Patients considering total elbow arthroplasty (TEA) may be receiving immunosuppressive therapy; however, the relationship between immunosuppressive medications and postoperative complications is not well defined. Our purpose was to assess the relationship between preoperative immunosuppression and short-term complications following TEA. METHODS: The American College of Surgeons National Surgical Quality Improvement Program database was reviewed from 2005 to 2020 to identify patients undergoing TEA. Procedures indicated for malignancy or infection were excluded. Patients were grouped according to preoperative chronic immunosuppressive status. Demographic and operative characteristics were compared between groups. The 30-day incidence of complications and reoperations were compared between groups. Multiple logistic regression models, inverse-weighted by propensity scores, were used to calculate odds ratio (OR) of experiencing any complication or return to the operating room based on immunosuppression status and other demographic characteristics. RESULTS: A total of 769 patients undergoing TEA were included, of whom 142 (18.5%) received chronic immunosuppression. Distribution of age, sex, race, body mass index, diabetes, and American Society of Anesthesiologists classification differed significantly between groups. Most procedures were performed on an inpatient basis, and the median operative duration was 148 minutes. Most procedures were indicated for fracture in the nonimmunosuppressed group and rheumatoid arthritis in the immunosuppressed group. Overall complication rates were 7.0% for immunosuppressed patients and 10.2% for nonimmunosuppressed patients. The incidence of complications and reoperations did not significantly differ between groups. After controlling for confounding and adjusting for patient characteristics, immunosuppressed patients were 0.52 times less likely to experience a complication. Additionally, there was no association between immunosuppression status and odds of return to the operating room. CONCLUSION: Similar rates of complications were observed following TEA, regardless of preoperative immunosuppression status. Chronic immunosuppression does not appear to increase the rates of postoperative complications for patients undergoing TEA. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic II.

Nano wear particles and the periprosthetic microenvironment in aseptic loosening induced osteolysis following joint arthroplasty.

Joint arthroplasty is an option for end-stage septic arthritis due to joint infection after effective control of infection. However, complications such as osteolysis and aseptic loosening can arise afterwards due to wear and tear caused by high joint activity after surgery, necessitating joint revision. Some studies on tissue pathology after prosthesis implantation have identified various cell populations involved in the process. However, these studies have often overlooked the complexity of the altered periprosthetic microenvironment, especially the role of nano wear particles in the etiology of osteolysis and aseptic loosening. To address this gap, we propose the concept of the "prosthetic microenvironment". In this perspective, we first summarize the histological changes in the periprosthetic tissue from prosthetic implantation to aseptic loosening, then analyze the cellular components in the periprosthetic microenvironment post prosthetic implantation. We further elucidate the interactions among cells within periprosthetic tissues, and display the impact of wear particles on the disturbed periprosthetic microenvironments. Moreover, we explore the origins of disease states arising from imbalances in the homeostasis of the periprosthetic microenvironment. The aim of this review is to summarize the role of relevant factors in the microenvironment of the periprosthetic tissues, in an attempt to contribute to the development of innovative treatments to manage this common complication of joint replacement surgery.

Association Between Thromboelastometry Identified Hypercoagulability and Thromboembolic Complications After Arthroplasty: A Prospective Observational Study in Patients With Obesity.

The prothrombotic state of obesity can increase the risk of thromboembolism. We aimed to investigate if there was an association between baseline hypercoagulable rotational thromboelastometry (ROTEM) profile and thromboembolic complications in arthroplasty patients with obesity. Patients with a body mass index ≥ 25 kg/m2 and/or waist circumference ≥94 cm (M) and 80 cm (F) undergoing hip and knee arthroplasty had pre- and postoperative ROTEM. ROTEM values were compared by outcome status using an independent sample equal-variance t-test. Of the 303 total participants, hypercoagulability defined as extrinsically activated thromboelastometry maximum clot firmness G score ≥ 11 K dyne/cm2, was observed in 90 (30%) of the 300 participants with preoperative ROTEM assays. Clinically significant thromboembolic complications occurred in 5 (1.7%) study participants before discharge and in 10 (3.3%) by 90 days. These included 6 with pulmonary emboli, 3 with deep venous thrombus, and 1 with myocardial infarction. We found no evidence for an association between baseline hypercoagulability and incident thromboembolic events, analysis limited by the number of events. Postoperative decrease in platelets and an increase in fibrinogen were observed. ROTEM parameter changes differed across obesity categories.

Short-term and Long-term Complications of Cervical Disc Arthroplasty.

STUDY DESIGN: A narrative review. OBJECTIVE: This review discusses the short and long-term complications associated with cervical disc arthroplasty (CDA). SUMMARY OF BACKGROUND DATA: CDA is a safe and effective motion-sparing alternative to fusion for the treatment of cervical disc pathology in patients with cervical radiculopathy or myelopathy. Although CDA offers advantages over fusion within a narrower set of indications, it introduces new technical challenges and potential complications. METHODS: A systematic search of several large databases, including Cochrane Central, PubMed, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry, was conducted from January 2005 to August 2023 to identify published studies and clinical trials evaluating cervical disc replacement complications and outcomes. RESULTS: Short-term complications are primarily related to surgical approach and include dysphagia reported as high as ~70%, laryngeal nerve injury ~0%-1.25%, Horner syndrome ~0.06%, hematoma ~0.01%, gross device extrusion ~0.3%, whereas long-term complications include adjacent segment disease reported at ~3.8%, osteolysis ~44%-64%, heterotopic ossification ~7.3%-69.2%, implant failure ~3.3%-3.7%, and implant wear, which varies depending on design. CONCLUSIONS: Approaches for mitigating complications broadly include meticulous dissection, intraoperative techniques, and diligent postoperative follow-up. This review emphasizes the need for a comprehensive understanding and management of complications to enhance the safety, reproducibility, and success of CDA. As CDA continues to evolve, there remains a critical need for ongoing research to delve deeper into evaluating risk for complications and long-term patient outcomes.

Characterization of periprosthetic environment microbiome in patients after total joint arthroplasty and its potential correlation with inflammation.

AIMS: Periprosthetic joint infection (PJI) is one of the most serious complications after total joint arthroplasty (TJA) but the characterization of the periprosthetic environment microbiome after TJA remains unknown. Here, we performed a prospective study based on metagenomic next-generation sequencing to explore the periprosthetic microbiota in patients with suspected PJI. METHODS: We recruited 28 patients with culture-positive PJI, 14 patients with culture-negative PJI, and 35 patients without PJI, which was followed by joint aspiration, untargeted metagenomic next-generation sequencing (mNGS), and bioinformatics analysis. Our results showed that the periprosthetic environment microbiome was significantly different between the PJI group and the non-PJI group. Then, we built a "typing system" for the periprosthetic microbiota based on the RandomForest Model. After that, the 'typing system' was verified externally. RESULTS: We found the periprosthetic microbiota can be classified into four types generally: "Staphylococcus type," "Pseudomonas type," "Escherichia type," and "Cutibacterium type." Importantly, these four types of microbiotas had different clinical signatures, and the patients with the former two microbiota types showed obvious inflammatory responses compared to the latter ones. Based on the 2014 Musculoskeletal Infection Society (MSIS) criteria, clinical PJI was more likely to be confirmed when the former two types were encountered. In addition, the Staphylococcus spp. with compositional changes were correlated with C-reactive protein levels, the erythrocyte sedimentation rate, and the synovial fluid white blood cell count and granulocyte percentage. CONCLUSIONS: Our study shed light on the characterization of the periprosthetic environment microbiome in patients after TJA. Based on the RandomForest model, we established a basic "typing system" for the microbiota in the periprosthetic environment. This work can provide a reference for future studies about the characterization of periprosthetic microbiota in periprosthetic joint infection patients.

The residual exposed endplate ratio is predictive of posterior heterotopic ossification after cervical Bryan disc arthroplasty.

OBJECTIVES: Heterotopic ossification (HO), a major cause of dysfunction after disc arthroplasty (CDA). The aim of this study was to determine the cut value of the residual exposed endplate (REE) ratio and to predict the development of posterior HO after Bryan CDA. METHODS: This retrospective study investigated the relationship between the REE ratio and posterior HO formation after Bryan CDA. Consecutive adult patients who underwent 1- or 2-level Bryan CDA by a single neurosurgeon between 2006 and 2016 with at least two years follow-up were included. Postoperative radiographic analysis and measurement were performed to obtain the REE ratio and the HO grade. RESULTS: Of 249 patients with 384 surgical levels who underwent Bryan CDA during the study period, 114 (45.8 %) received 1-level CDA and 135 (54.2 %) received 2-level CDA. Lateral radiographs showed that 169 implants (44 %) had posterior HOs in all grades after two years or more of follow up and 14 implants (3.64 %) had severe HO (McAfee grades 3 and 4). In 329 implants (85.7 %), a comparison of radiographs to CT examination of HO grading showed a substantial relationship. Using area under the curve (AUC) analysis, a REE ratio >9 %, with 65.1 % sensitivity and 86.5 % specificity, was the cut point for posterior HO formation. CONCLUSIONS: REE is highly correlated with the development of postoperative posterior HO after Bryan CDA, regardless of the level of implantation. An undersized implant causing a REE ratio >9 % is a predictor of postoperative posterior HO formation after cervical Bryan CDA.

Outcomes of patients undergoing single-level arthroplasty versus anterior lumbar interbody fusion.

BACKGROUND: Compared to vertebral body fusion, artificial discs are thought to lessen the risks of adjacent segment disease and the need for additional surgery by maintaining spinal mobility as they mimic the intervertebral disc structure. No studies have compared the rates of postoperative complications and the requirement for secondary surgery at adjacent segments among patients who have undergone anterior lumbar interbody fusions (ALIF) versus those undergoing lumbar arthroplasty. METHODS: An all-payer claims database identified 11,367 individuals who underwent single-level ALIF and lumbar arthroplasty for degenerative disc disease (DDD) between January 2010 and October 2020. Rates of complications following surgery, the need for additional lumbar surgeries, length of stay (LOS), and postoperative opioid utilization were assessed in matched cohorts based on logistic regression models. Kaplan-Meyer plots were created to model the probability of additional surgery. RESULTS: Following 1:1 exact matching, 846 records of patients who had undergone ALIF or lumbar arthroplasty were analyzed. All-cause readmission within 30-30 days following surgery was significantly higher in patients undergoing ALIF versus arthroplasty (2.6% vs. 0.71%, p = 0.02). LOS was significantly lower among the patients who had undergone ALIF (1.043 ± 0.21 vs. 2.17 ± 1.7, p < .001). CONCLUSIONS: ALIF and lumbar arthroplasty procedures are equally safe and effective in treating DDD. Our findings do not support that single-level fusions may biomechanically necessitate revisional surgeries.