The Association Between Surgeon Volume and Dislocation After Total Hip Arthroplasty: A Nationwide Evaluation of 5,106 Orthopaedic Surgeons.

INTRODUCTION: The relationship between surgeon volume and risk of dislocation after total hip arthroplasty (THA) is debated. This study sought to characterize this association and assess patient outcomes using a nationwide patient and surgeon registry. METHODS: The Premier Healthcare Database was queried for adult primary elective THA patients from January 1, 2016, to December 31, 2019. Annual surgeon volume and 90-day risk of dislocation were modeled using multivariable logistic regression with restricted cubic splines. Bootstrap analysis identified a threshold annual case volume, corresponding to the maximum decrease in dislocation risk. Surgeons with an annual volume greater than the threshold were deemed high volume, and those with an annual volume less than the threshold were low volume. Each surgeon within a given year was treated as a unique entity (surgeon-year unit). 90-day complications of patients treated by high-volume and low-volume surgeons were compared. RESULTS: From 2016 to 2019, 352,131 THAs were performed by 5,106 surgeons. The restricted cubic spline model demonstrated an inverse relationship between risk of dislocation and surgeon volume (threshold: 109 cases per year). A total of 9,967 (87.8%) low-volume surgeon-year units had individual dislocation rates lower than the average of the entire surgeon cohort. Patients treated by high-volume surgeons had decreased risk of dislocation (adjusted odds ratio [aOR], 0.60; 95% CI, 0.54 to 0.67), periprosthetic fracture (aOR, 0.87; 95% CI, 0.76 to 0.99), periprosthetic joint infection (aOR, 0.63; 95% CI, 0.56 to 0.69), readmission (aOR, 0.70; 95% CI, 0.67 to 0.73), and in-hospital death (aOR, 0.60; 95% CI, 0.46 to 0.80). CONCLUSION: While most of the low-volume surgeons had dislocation rates lower than the cohort average, increasing annual surgeon case volume was associated with a reduction in risk of dislocation after primary elective THA. THERAPEUTIC LEVEL OF EVIDENCE: Level IV.

Risk Factors for Peripheral Nerve Injury Following Revision Total Hip Arthroplasty in 112,310 Patients.

Background: Peripheral nerve injury (PNI) following revision total hip arthroplasty (rTHA) can be a devastating complication. This study assessed the frequency of and risk factors for postoperative PNI following rTHA. Methods: Patients who underwent rTHA from 2003 to 2015 were identified using the National Inpatient Sample (NIS). Demographics, medical history, surgical details, and complications were compared between patients who sustained a PNI and those who did not, to identify risk factors for the development of PNI after rTHA. Results: Overall, 112,310 patients who underwent rTHA were identified, 929 (0.83%) of whom sustained a PNI. Univariate analysis found that younger patients (p < 0.0001), females (p = 0.025), and those with a history of flexion contracture (0.65% vs. 0.22%, p = 0.005), hip dislocation (24.0% vs. 18.0%, p < 0.001), and spine conditions (4.8% vs. 2.7%, p < 0.001) had significantly higher rates of PNI. In-hospital complications associated with PNI included postoperative hematoma (2.6% vs. 1.2%, p < 0.0001), postoperative seroma (0.75% vs. 0.30%, p = 0.011), superficial wound dehiscence (0.65% vs. 0.23%, p = 0.008), and postoperative anemia (36.1% vs. 32.0%, p = 0.007). Multivariate analysis demonstrated that a history of pre-existing spine conditions (aOR: 1.7; 95%-CI: 1.3-2.4, p < 0.001), prior dislocation (aOR 1.5; 95%-CI: 1.3-1.7, p < 0.001), postoperative anemia (aOR 1.2; 95%-CI: 1.0-1.4, p = 0.01), and hematoma (aOR 2.1; 95%-CI: 1.4-3.2, p < 0.001) were associated with increased risk for PNI. Conclusions: Our findings align with the existing literature, affirming that sciatic nerve injury is the prevailing neuropathic complication after total hip arthroplasty (THA). Furthermore, we observed a 0.83% incidence of PNI following rTHA and identified pre-existing spine conditions, prior hip dislocation, postoperative anemia, or hematoma as risk factors. Orthopedic surgeons may use this information to guide their discussion of PNI following rTHA, especially in high-risk patients.

An Updated Estimate of Total Hip and Total Knee Arthroplasty Inpatient Case Volume During the 2020 COVID-19 Pandemic in the United States.

Background: Inpatient total hip arthroplasty (THA) and total knee arthroplasty (TKA) practices were dramatically affected in the United States in 2020 as elective surgeries were paused in response to the COVID-19 pandemic. This study sought to provide an updated estimate of inpatient total joint arthroplasty (TJA) case volumes in the United States in 2020. Methods: A retrospective cohort study was performed by identifying all adult patients who underwent primary, elective TJA from January 1st, 2017 to December 31st, 2020, using the National Inpatient Sample. Monthly and annual case volumes were reported with descriptive statistics. Baseline case volumes were established by taking the average number of monthly cases performed in 2017, 2018, and 2019. These monthly averages were compared to 2020 values. Results: From 2017 to 2019, the average case volume was 1,056,669 cases per year (41.0% THA, 59.0% TKA) and 88,055 cases per month. In 2020, 535,441 cases were identified (45.4% THA, 54.6% TKA), corresponding to a 49.3% reduction from the 2017-2019 annual average. Monthly cases decreased to 4515 in April during the "first wave" of COVID-19, corresponding to a 94.8% decrease from prior years. In June, cases rebounded to 55,520 before decreasing again in July to 50,100 during the "second wave" of COVID-19. During the "third wave," COVID-19 cases decreased month-over-month from October through December (56.5% decrease). Conclusions: This updated estimate identified a 49.3% decrease in inpatient TJA cases in 2020 compared to prior years. This is similar to the 46.5-47.7% decrease in case volume previously reported.

Metal artifact reduction sequence-MRI abnormalities in asymptomatic patients with dual-mobility hip prostheses.

Aims: Modular dual-mobility (DM) articulations are increasingly used during total hip arthroplasty (THA). However, concerns remain regarding the metal liner modularity. This study aims to correlate metal artifact reduction sequence (MARS)-MRI abnormalities with serum metal ion levels in patients with DM articulations. Methods: A total of 45 patients (50 hips) with a modular DM articulation were included with mean follow-up of 3.7 years (SD 1.2). Enrolled patients with an asymptomatic, primary THA and DM articulation with over two years' follow-up underwent MARS-MRI. Each patient had serum cobalt, chromium, and titanium levels drawn. Patient satisfaction, Oxford Hip Score, and Forgotten Joint Score-12 (FJS-12) were collected. Each MARS-MRI was independently reviewed by fellowship-trained musculoskeletal radiologists blinded to serum ion levels. Results: Overall, two patients (4.4%) had abnormal periprosthetic fluid collections on MARS-MRI with cobalt levels > 3.0 µg/l. Four patients (8.9%) had MARS-MRI findings consistent with greater trochanteric bursitis, all with cobalt levels < 1.0 µg/l. A seventh patient had a periprosthetic fluid collection with normal ion levels. Of the 38 patients without MARS-MRI abnormalities, 37 (97.4%) had cobalt levels < 1.0 µg/l, while one (2.6%) had a cobalt level of 1.4 µg/l. One patient (2.2%) had a chromium level > 3.0 µg/l and a periprosthetic fluid collection. Of the 41 patients with titanium levels, five (12.2%) had titanium levels > 5.0 µg/l without associated MARS-MRI abnormalities. Conclusion: Periprosthetic fluid collections associated with elevated serum cobalt levels in patients with asymptomatic DM articulations occur infrequently (4.4%), but further assessment is necessary due to implant heterogeneity.

Intravenous tranexamic acid reduces complications following surgical treatment of pathologic fractures of the lower extremity.

BACKGROUND AND OBJECTIVES: This study aimed to evaluate the postoperative complications associated with administering intravenous (IV) tranexamic acid (TXA) in patients undergoing surgical fixation for neoplastic pathologic fractures of the lower extremities. METHODS: Patients ≥18 years old who underwent surgical intervention for neoplastic pathologic lower extremity fractures from 2015 to 2021 were identified using the Premier Healthcare Database. This cohort was divided by TXA receipt on the index surgery day. Patient demographics, hospital factors, patient comorbidities, and 90-day complications were assessed and compared between the cohorts. RESULTS: From 2015 to 2021, 4497 patients met inclusion criteria (769 TXA[+] and 3728 TXA[-]). Following propensity score matching, patients who received TXA had a significantly shorter length of stay than those who did not (7.6 ± 7.3 days vs. 9.0 ± 15.2, p = 0.036). Between the two cohorts, there were no significant differences in comorbidities. Regarding differences in postoperative complications, TXA(+) patients had significantly decreased odds of deep vein thrombosis (DVT) (1.87% vs. 5.46%; odds ratio [OR]:0.33; 95% confidence interval: 0.17-0.62; p = 0.001). CONCLUSION: Administration of IV TXA may be associated with a decreased risk of postoperative DVT without an increased risk of other complications. Orthopedic surgeons should consider the utilization of IV TXA in patients treated surgically for neoplastic pathologic fractures of the lower extremity.

Characteristics of Very Young Patients Undergoing Total Hip Arthroplasty: A Contemporary Assessment.

Background: This study aims to compare indications, patient characteristics, hospital factors, and complication rates between total hip arthroplasty (THA) patients aged 30 years or younger and those older than 30 years using a large national database. Methods: The Premier Healthcare Database was utilized to identify primary THA patients from 2015 to 2021 who were aged ≤30 or >30 years. Patient demographics, hospital factors, and primary indications were compared for each cohort. Rates of complications and readmissions were assessed for each cohort by primary indication. Differences were assessed through univariate analysis. Results: Overall, 539,173 primary THA patients were identified (age ≤30: 1849; >30: 537,234). Compared to the >30 cohort, the ≤30 cohort was more likely to be male (56.5% vs 44.9%, P < .001) and non-White (34.0% vs 14.2%, P < .001). The most common indications for THA in the ≤30 cohort were osteonecrosis (49.3%), osteoarthritis (17.8%), and congenital hip deformities (16.0%), and in the >30 cohort, they were osteoarthritis (77.0%), other arthritis (11.3%), and osteonecrosis (5.4%). Patients aged ≤30 years had lower rates of respiratory failure (0.16% vs 0.57%, P < .001), acute renal failure (0.32% vs 1.72%, P < .001), and urinary tract infection (0.38% vs 1.11%, P = .003) than those aged >30 years, but higher rates of wound dehiscence (0.59% vs 0.29%, P = .015) and transfusion (3.68% vs 2.21%, P < .001). There were no differences in 90-day readmission rates (P = .811) or 90-day in-hospital death (P = .173) between cohorts. Conclusions: Younger patients undergoing THA differed significantly in indication, patient characteristics, and hospital factors compared to the older population on univariate analysis. Despite differences in indications, the cohorts did not differ markedly with regard to complication rates in this study.

Risk Factors for Peripheral Nerve Injury Following Revision Total Knee Arthroplasty in 132,960 Patients.

BACKGROUND: Peripheral nerve injury (PNI) following revision total knee arthroplasty (rTKA) is a potentially devastating injury for patients. This study assessed the frequency of and risk factors for postoperative PNI following rTKA. METHODS: Patients who underwent rTKA from 2003 to 2015 were identified using the National Inpatient Sample. Demographics, medical histories, surgical details, and complications were compared between patients who sustained a PNI and those who did not to identify risk factors for the development of PNI after rTKA. RESULTS: Overall, 132,960 patients who underwent rTKA were identified, and 737 (0.56%) sustained a postoperative PNI. After adjusting for confounders, patients with a history of a spine condition (adjusted odds ratio [aOR]: 1.7, 95%-confidence interval 1.2 to 2.4, P = .003) and postoperative anemia (aOR: 1.3, 95%-CI: 1.1 to 1.5, P = .004) had higher risk of PNI following rTKA. Intraoperative periprosthetic fracture (aOR: 1.3, 0.78 to 2.2, P = .308), rheumatoid arthritis (aOR: 1.0, 95%-CI: 0.68 to 1.6, P = .865), and history of knee dislocation (aOR: 1.1, 95%-CI: 0.85 to 1.5, P = .412), were not significantly associated with higher risk for PNI. CONCLUSIONS: This study found a 0.56% incidence of PNI following rTKA, and patients who had preexisting spine conditions or postoperative anemia were at an increased risk for this complication. Orthopedic surgeons may use the results of this study to appropriately counsel patients on the potential for a PNI following rTKA.

Use of Surgical Adjuvants Does Not Decrease Recurrence of Aneurysmal Bone Cysts in Surgical Intervention With Pediatric Patients.

BACKGROUND: Aneurysmal bone cysts (ABCs) are benign active tumors often requiring intralesional curettage with or without adjuvants. The primary aim of this study was to analyze whether recurrence is influenced by the use of surgical adjuvants in pediatric patients with ABCs. Secondary aims examined recurrence rates based on age, sex, and physeal contact. METHODS: A retrospective review was performed at a tertiary pediatric hospital from 2004 to 2020. Inclusion criteria consisted of patients treated surgically for histologically confirmed ABCs with a minimum of 6 months follow-up. Patients with treatment for a recurrent tumor or incomplete records were excluded. Patient demographics, location of the lesion, treatment technique, and incidence of recurrence were collected. Statistical analyses were performed using STATA. RESULTS: There were 129 patients (74 males and 55 females) with a mean age of 11.5 ± 4.1 years and an average follow-up of 29.0 ± 25.4 months. The most common locations for ABCs were the femur and tibia. Of the patients, 53.5% had tumors abutting the physis, 28.7% had no physeal contact, and 17.8% had insufficient imaging to evaluate physeal contact. Surgical adjuvants (high-speed burr, coagulation, liquid nitrogen, and/or hydrogen peroxide) were used in 91 of the 129 cases (70.5%). There was no significant difference in recurrence when comparing those who received an adjuvant and those who did not (25.3% vs 23.7%, P = 1.000). Physeal contact was also not significantly associated with recurrence ( P = 0.146). Finally, patients younger than 6 years old were significantly more likely to have recurrence compared with those 6 years old or older (66.7% vs 21.7%, P = 0.007). CONCLUSION: Our study found no association between the use of surgical adjuvants and the risk of recurrence after intralesional curettage for ABCs. Although our study did demonstrate that patients 6 years old or younger had an increased rate of recurrence, no significant association was found regarding physeal contact or sex. These data indicate that surgical adjuvant may not affect the recurrence rates of pediatric patients with ABCs. LEVEL OF EVIDENCE: Level III. This retrospective review compares rates of recurrence based on the choice of surgical adjuvant.

Tandem Reconstruction of the Femoral Diaphysis Using an Intercalary Prosthesis and a Fibular Free Flap.

BACKGROUND: Femoral diaphyseal reconstructions with metal prostheses have mediocre results because of high mechanical forces that result in eventual implant failure. Biological alternatives require prolonged restrictions on weight-bearing and have high rates of infection, nonunion, and fracture. A novel method of utilizing a vascularized fibula in combination with an intercalary prosthesis was developed to complement the immediate stability of the prosthesis with the long-term biological fixation of a vascularized fibular graft. METHODS: A prospectively maintained database was retrospectively reviewed to identify patients who underwent reconstruction of an oncological intercalary femoral defect using an intercalary prosthesis and an inline fibular free flap (FFF). They were compared with patients who underwent femoral reconstruction using an intercalary allograft and an FFF. RESULTS: Femoral reconstruction with an intercalary metal prosthesis and an FFF was performed in 8 patients, and reconstruction with an allograft and an FFF was performed in 16 patients. The mean follow-up was 5.3 years and 8.5 years, respectively (p = 0.02). In the bioprosthetic group, radiographic union of the fibula occurred in 7 (88%) of 8 patients, whereas in the allograft group, 13 (81%) of 16 patients had allograft union (p = 1.00) and all 16 patients had fibular union (p = 0.33). The mean time to fibular union in the bioprosthetic group was 9.0 months, whereas in the allograft group, the mean time to allograft union was 15.3 months (p = 0.03) and the mean time to fibular union was 12.5 months (p = 0.42). Unrestricted weight-bearing occurred at a mean of 3.7 months in the prosthesis group and 16.5 months in the allograft group (p < 0.01). Complications were observed in 2 (25%) of 8 patients in the prosthesis group and in 13 (81%) of 16 patients in the allograft group (p = 0.02). Neither chemotherapy nor radiation affected fibular or allograft union rates. Musculoskeletal Tumor Society scores did not differ significantly between the groups (mean, 26 versus 28; p = 0.10). CONCLUSIONS: Bioprosthetic intercalary femoral reconstruction with a metal prosthesis and an FFF resulted in earlier weight-bearing, a shorter time to union, fewer operations needed for union, and lower complication rates than reconstruction with an allograft and an FFF. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Postoperative Complications Associated with Non-Steroidal Anti-Inflammatory Combinations Used Status-Post Total Hip and Knee Arthroplasty.

Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used in multimodal pain control following total joint arthroplasty (TJA). However, few studies have assessed the complications associated with the combinations of NSAIDs in this population despite the known risks associated with this class of medications. The Premier Healthcare Database was queried to identify adults who underwent primary total hip or knee arthroplasty from 2005-2014. The following most common inpatient combinations of NSAIDs were chosen for analysis: aspirin + celecoxib (A + C), toradol + aspirin (T + A), toradol + ibuprofen (T + I), celecoxib + ibuprofen (C + I), ibuprofen + aspirin (I + A), and toradol + celecoxib (T + C). Primary outcomes included acute kidney injury (AKI), gastrointestinal bleed, and stroke. Secondary outcomes included periprosthetic joint infection (PJI), deep vein thrombosis, and pulmonary embolism. Univariate and multivariate regression analyses were used to compare differences and address confounds. Overall, 195,833 patients were identified. After controlling for confounds, increased odds of AKI was associated with A + C (adjusted odds ratio [aOR]: 1.20, 95% confidence interval [CI]: 1.09-1.34, p < 0.001) and decreased odds was associated with T + A (aOR 0.76, 95% CI: 0.69-0.83, p < 0.001). Increased odds of stroke was associated with A + C (aOR: 1.80, 95% CI: 1.15-2.84, p = 0.011); T + I (aOR 3.48, 95% CI: 1.25-9.73, p = 0.017); and I + A (aOR 4.29, 95% CI: 1.06-17.9, p = 0.046). Increased odds of PJI was associated with C + I (aOR: 10.3, 95% CI: 1.35-78.3, p = 0.024). In the TJA patient population, NSAID pairings should be regarded as distinct entities. Our results suggest that combinations including A + C, T + I, I + A, and C + I should be used cautiously. With this knowledge, providers should consider tailoring NSAID prescriptions appropriately.

Medicare Advantage in Soft Tissue Sarcoma May Be Associated with Worse Patient Outcomes.

Medicare Advantage healthcare plans may present undue impediments that result in disparities in patient outcomes. This study aims to compare the outcomes of patients who underwent STS resection based on enrollment in either traditional Medicare (TM) or Medicare Advantage (MA) plans. The Premier Healthcare Database was utilized to identify all patients ≥65 years old who underwent surgery for resection of a lower-extremity STS from 2015 to 2021. These patients were then subdivided based on their Medicare enrollment status (i.e., TM or MA). Patient characteristics, hospital factors, and comorbidities were recorded for each cohort. Bivariable analysis was performed to assess the 90-day risk of postoperative complications. Multivariable analysis controlling for patient sex, as well as demographic and hospital factors found to be significantly different between the cohorts, was also performed. From 2015 to 2021, 1858 patients underwent resection of STS. Of these, 595 (32.0%) had MA coverage and 1048 (56.4%) had TM coverage. The only comorbidities with a significant difference between the cohorts were peripheral vascular disease (p = 0.027) and hypothyroidism (p = 0.022), both with greater frequency in MA patients. After controlling for confounders, MA trended towards having significantly higher odds of pulmonary embolism (adjusted odds ratio (aOR): 1.98, 95% confidence interval (95%-CI): 0.58-6.79), stroke (aOR: 1.14, 95%-CI: 0.20-6.31), surgical site infection (aOR: 1.59, 95%-CI: 0.75-3.37), and 90-day in-hospital death (aOR 1.38, 95%-CI: 0.60-3.19). Overall, statistically significant differences in postoperative outcomes were not achieved in this study. The authors of this study hypothesize that this may be due to study underpowering or the inability to control for other oncologic factors not available in the Premier database. Further research with higher power, such as through multi-institutional collaboration, is warranted to better assess if there truly are no differences in outcomes by Medicare subtype for this patient population.

Increased Risk of Venous Thromboembolism in Patients with Postoperative Anemia After Total Joint Arthroplasty: Are Transfusions to Blame?

BACKGROUND: The relationship between anemia and the risk of venous thromboembolism (VTE) following total knee arthroplasty (TKA) and total hip arthroplasty (THA) remains unclear. Red blood cell (RBC) transfusions, which have been shown to have thrombogenic effects, may explain conflicting data. This study sought to elucidate the relationship between anemia, RBC transfusions, and VTE following total joint arthroplasty (TJA). METHODS: Using the International Classification of Diseases, Tenth Revision (ICD-10) and Current Procedural Terminology (CPT) codes, the Premier Healthcare Database was queried for all adults who underwent primary elective THA or TKA from January 2015 to December 2020. Patients were classified into 3 cohorts: those who did not have a diagnosis of anemia and did not receive an RBC transfusion (the control group), those with acute blood loss anemia who did not receive a transfusion (the anemia without transfusion group), and those with acute blood loss anemia who did receive a transfusion (the anemia with transfusion group). The primary outcomes assessed were the 90-day rate and risk of deep vein thrombosis (DVT), pulmonary embolism (PE), and aggregate VTE. Analysis of variance and pairwise comparisons were used to compare groups. Multivariable analyses were performed to account for confounding factors. RESULTS: The 1,290,815 patients identified as having undergone TJA included 1,078,507 control patients (83.6%), 198,233 patients who had anemia without transfusion (15.4%), and 14,075 patients who had anemia and transfusion (1.1%). Age, sex, race, length of hospital stay, and hospital costs were significantly different between the 3 groups. After adjusting for confounding factors, there was no difference between the anemia without transfusion group and the control group with regard to DVT (adjusted odds ratio [OR], 0.97 [95% confidence interval (CI), 0.89 to 1.06]; p = 0.500), PE (adjusted OR, 1.04 [95% CI, 0.92 to 1.18]; p = 0.543), and VTE (adjusted OR, 0.99 [95% CI, 0.92 to 1.06]; p = 0.697). However, patients with anemia and transfusion had an increased risk of PE (adjusted OR, 1.83 [95% CI, 1.34 to 2.51]; p < 0.001) and VTE (adjusted OR, 1.39 [95% CI, 1.14 to 1.70]; p = 0.001) compared with patients in the control group. CONCLUSIONS: Patients with acute blood loss anemia who received a transfusion were at increased risk for developing VTE following TJA, whereas patients with anemia who did not receive a transfusion were not. Orthopaedic surgeons need to be aware of the risks of transfusion and individualize the use of transfusions in their patients. LEVEL OF EVIDENCE: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Complications of cryoprobe cryoablation as a surgical adjuvant for the treatment of metastatic carcinoma to bone, benign bone tumors, and soft tissue tumors: A series of 148 patients.

BACKGROUND AND OBJECTIVE: This study describes the complication profile of modern cryoablation utilizing probes as an adjuvant during open surgical treatment of orthopedic tumors. METHODS: A retrospective, single-surgeon study was performed for patients receiving cryoprobe cryoablation. Demographic information, malignancy-related and operative details, and clinical courses were collected. Outcomes assessed included rates of complications, recurrence, and correlations between the number of probes or cryoablation cycles performed. RESULTS: In this 148-patient study, 67.6% had metastatic carcinoma to bone, 27.7% had benign bone tumors, and 4.7% had soft tissue tumors. An average of 3.4 ± 1.7 cryoablation probes were utilized and 1.7 ± 0.6 freezing cycles were performed. The overall cohort aggregate complication rate was 16.9%. These complications included postoperative fracture (3.4%), nerve palsy (2.7%), wound complications (7.4%), and infection (3.4%). The number of cycles and probes was significantly correlated with the incidence of aggregate complications in the overall cohort (Pearson = 0.162, p = 0.049) and metastatic bone cohort (Pearson = 0.222, p = 0.027). There were 13 recurrences. CONCLUSION: This study describes the complication rates involving cryoablation probes used as surgical adjuvants. Greater probe number usage was correlated with increased aggregate complications in patients with metastatic disease to bone; meanwhile, more treatment cycles were associated with increased aggregate complications in the overall cohort.

Complications and Safety of Simultaneous Bilateral Total Knee Arthroplasty: A Patient Characteristic and Comorbidity-Matched Analysis.

BACKGROUND: Total knee arthroplasty (TKA) is a highly successful surgical procedure that decreases pain and improves function. Many patients who undergo TKA may require surgical intervention on both extremities because of bilateral osteoarthritis. The purpose of this study was to evaluate the safety of simultaneous bilateral TKA compared with that of unilateral TKA. METHODS: Patients who underwent unilateral or simultaneous bilateral primary, elective TKA from 2015 to 2020 were identified using the Premier Healthcare Database. Subsequently, the simultaneous bilateral TKA cohort was matched to the unilateral TKA cohort in a 1:6 ratio by age, sex, race, and presence of pertinent comorbidities. Patient characteristics, hospital factors, and comorbidities were compared between the cohorts. The 90-day risks of postoperative complications, readmission, and in-hospital death were assessed. Differences were assessed using univariable regression, and multivariable regression analyses were performed to account for potential confounders. RESULTS: Overall, 21,044 patients who underwent simultaneous bilateral TKA and 126,264 matched patients who underwent unilateral TKA were included. After accounting for confounding factors, patients who underwent simultaneous bilateral TKA demonstrated a significantly increased risk of postoperative complications, including pulmonary embolism (adjusted odds ratio [OR], 2.13 [95% confidence interval (CI), 1.57 to 2.89]; p < 0.001), stroke (adjusted OR, 2.21 [95% CI, 1.42 to 3.42]; p < 0.001), acute blood loss anemia (adjusted OR, 2.06 [95% CI, 1.99 to 2.13]; p < 0.001), and transfusion (adjusted OR, 7.84 [95% CI, 7.16 to 8.59]; p < 0.001). Patients who underwent simultaneous bilateral TKA were at increased risk of 90-day readmission (adjusted OR, 1.35 [95% CI, 1.24 to 1.48]; p < 0.001). CONCLUSIONS: Simultaneous bilateral TKA was associated with increased rates of complications including pulmonary embolism, stroke, and transfusion. Orthopaedic surgeons and patients should consider these potential complications when contemplating simultaneous bilateral TKA. When simultaneous bilateral TKA is pursued, patient counseling and thorough medical optimization should be performed. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Prevalence of primary malignant tumours, rates of pathological fracture, and mortality in the setting of metastatic bone disease.

Aims: The modern prevalence of primary tumours causing metastatic bone disease is ill-defined in the oncological literature. Therefore, the purpose of this study is to identify the prevalence of primary tumours in the setting of metastatic bone disease, as well as reported rates of pathological fracture, postoperative complications, 90-day mortality, and 360-day mortality for each primary tumour subtype. Methods: The Premier Healthcare Database was queried to identify all patients who were diagnosed with metastatic bone disease from January 2015 to December 2020. The prevalence of all primary tumour subtypes was tabulated. Rates of long bone pathological fracture, 90-day mortality, and 360-day mortality following surgical treatment of pathological fracture were assessed for each primary tumour subtype. Patient characteristics and postoperative outcomes were analyzed based upon whether patients had impending fractures treated prophylactically versus treated completed fractures. Results: In total, 407,893 unique patients with metastatic bone disease were identified. Of the 14 primary tumours assessed, metastatic bone disease most frequently originated from lung (24.8%), prostatic (19.4%), breast (19.3%), gastrointestinal (9.4%), and urological (6.5%) malignancies. The top five malignant tumours resulting in long bone pathological fracture were renal (5.8%), myeloma (3.4%), female reproductive (3.2%), lung (2.8%), and breast (2.7%). Following treatment of pathological fractures of long bones, 90-day mortality rates were greatest for lung (12.1%), central nervous system (10.5%), lymphoma (10.4%), gastrointestinal (10.1%), and non-renal urinary (10.0%) malignancies. Finally, our study demonstrates improved 90-day and 360-day survival in patients treated for impending pathological fracture compared to completed fracture, as well as significantly lower rates of deep vein thrombosis, pulmonary embolism, urinary tract infection, and blood transfusion. Conclusion: This study defines the contemporary characteristics of primary malignancies resulting in metastatic bone disease. These data should be considered by surgeons when prognosticating patient outcomes during treatment of their metastatic bone disease.

Increased Complication Risk Associated With Simultaneous Bilateral Total Hip Arthroplasty: A Contemporary, Matched Cohort Analysis.

BACKGROUND: Simultaneous bilateral total hip arthroplasty (sbTHA) continues to be performed in patients who have bilateral end-stage osteoarthritis. However, few studies have evaluated the risk associated with this practice compared to unilateral total hip arthroplasty (THA). METHODS: Using a large national database, primary, elective sbTHAs, and unilateral THAs were identified from January 1, 2015 to December 31, 2021. The sbTHAs were matched to unilateral THAs at a 1:5 ratio on age, sex, and pertinent comorbidities. Patient characteristics and comorbidities, and hospital factors were compared between both cohorts. Additionally, 90-day risk of postoperative complications, readmissions, and in-hospital deaths were assessed. After matching, 2,913 sbTHAs were compared to 14,565 unilateral THAs with an average age of 58.5 ± 10.0 years. RESULTS: Compared to unilateral patients, sbTHA patients demonstrated higher rates of pulmonary embolism (PE) (0.4 versus 0.2%, P = .002), acute renal failure (1.2 versus 0.7%, P = .007), acute blood loss anemia (30.4 versus 16.7%, P < .001), and need for transfusion (6.6 versus 1.8%, P < .001). After accounting for confounders, sbTHA patients demonstrated increased risk of PE (adjusted odds ratio [aOR]: 3.76, 95% CI: 1.84 to 7.70, P < .001), acute renal failure (aOR: 1.83, 95% CI: 1.23 to 2.72, P = .003), acute blood loss anemia (aOR: 2.3, 95% CI: 2.10 to 2.53, P < .001), and transfusion (aOR: 4.08, 95% CI: 3.35 to 4.98, P < .001) compared to unilateral THA patients. CONCLUSION: The practice of performing sbTHA was associated with an increased risk of PE, acute renal failure, and risk of transfusion. Careful evaluation of patient-specific risk factors is warranted when considering these bilateral procedures.

Refining the Role of Routine Synovial Alpha-Defensin in Periprosthetic Joint Infection Following Total Knee Arthroplasty: An Analysis of Limitations.

BACKGROUND: The utility of the synovial alpha-defensin test in diagnosing periprosthetic joint infections (PJIs) remains controversial. This study aimed to examine the diagnostic utility of this test. METHODS: A retrospective review was conducted to identify adults evaluated for PJI following total knee arthroplasty at a single institution. Patient demographics, laboratory results, and operative details were recorded. Using the 2018 Musculoskeletal Infection Society (MSIS) criteria, cases were categorized as definitive, inconclusive, or negative for PJI. The sensitivity, specificity, positive predictive value, and negative predictive value of each MSIS criterion was determined. The number of patients whose PJI diagnosis was contingent on alpha-defensin positivity was calculated. RESULTS: Overall, 172 total knee arthroplasty patients were included, who had an average age of 70.4 years (range, 39 to 95). Of the 21 patients who met major criteria, 20 (95.2%) were alpha-defensin positive. Of the remaining 151 patients, 85 did not meet minor criteria, all of whom were alpha-defensin negative. Among the 30 patients who met minor criteria, 28 (93.3%) were alpha-defensin positive and 2 (6.7%) were negative. The remaining 36 patients were deemed inconclusive preoperatively. In total, alpha-defensin testing changed the diagnosis in only 9 of 172 patients (5.2%). The sensitivity, specificity, positive predictive value, and negative predictive value of alpha-defensin in this cohort were 94.1, 100, 100, and 97.6, respectively. CONCLUSION: Alpha-defensin may assist in the diagnosis of PJI when a preoperative workup is inconclusive. However, this test is often unnecessary when the diagnosis of PJI can be made using the 2018 MSIS criteria.

Cemented versus Cementless Femoral Fixation for Elective Primary Total Hip Arthroplasty: A Nationwide Analysis of Short-Term Complication and Readmission Rates.

Cementless fixation during total hip arthroplasty (THA) is the predominant mode of fixation utilized for both acetabular and femoral components during elective primary THAs performed in the United States. This study aims to compare early complication and readmission rates between primary THA patients receiving cemented versus cementless femoral fixation. The 2016-2017 National Readmissions Database was queried to identify patients undergoing elective primary THA. Postoperative complication and readmission rates at 30, 90, and 180 days were compared between cemented and cementless cohorts. Univariate analysis was conducted to compare differences between cohorts. Multivariate analysis was performed to account for confounding variables. Of 447,902 patients, 35,226 (7.9%) received cemented femoral fixation, while 412,676 (92.1%) did not. The cemented group was older (70.0 vs. 64.8, p < 0.001), more female (65.0% vs. 54.3%, p < 0.001), and more comorbid (CCI 3.65 vs. 3.22, p < 0.001) compared to the cementless group. On univariate analysis, the cemented cohort had decreased odds of periprosthetic fracture at 30 days postoperatively (OR: 0.556, 95%-CI 0.424-0.729, p < 0.0001), but higher odds of hip dislocation, periprosthetic joint infection, aseptic loosening, wound dehiscence, readmission, medical complications, and death at all timepoints. On multivariate analysis, the cemented fixation cohort demonstrated reduced odds of periprosthetic fracture at all postoperative timepoints: 30 (OR: 0.350, 95%-CI 0.233-0.506, p < 0.0001), 90 (OR: 0.544, 95%-CI 0.400-0.725, p < 0.0001), and 180 days (OR: 0.573, 95%-CI 0.396-0.803, p = 0.002). Cemented femoral fixation was associated with significantly fewer short-term periprosthetic fractures, but more unplanned readmissions, deaths, and postoperative complications compared to cementless femoral fixation in patients undergoing elective THA.

Factors Associated With Failure Following Proximal Femoral Replacement for Salvage Hip Surgery for Nononcologic Indications.

BACKGROUND: Proximal femoral replacement (PFR) is used when extensive proximal femoral bone loss is encountered during revision total hip arthroplasty. However, further data on 5-to-10-year survivorship and predictors of failure are needed. Our aim was to assess the survivorship of contemporary PFRs used for nononcologic indications and determine factors associated with failure. METHODS: A single-institution retrospective observational study was conducted between June 1, 2010 and August 31, 2021 for patients undergoing PFR for non-neoplastic indications. Patients were followed for a minimum of 6 months. Demographic, operative, clinical, and radiographic data were collected. Implant survivorship was determined via Kaplan-Meier analysis of 56 consecutive cemented PFRs in 50 patients. RESULTS: At a mean follow-up of 4 years, the mean Oxford Hip Score was 36.2 and patient satisfaction was rated at an average of 4.7 of 5 on the Likert scale. Radiographic evidence of femoral-sided aseptic loosening was determined in 2 PFRs at a median of 9.6 years. The 5-year survivorship with all-cause reoperation and revision as end points was 83.2% (95% Confidence Interval [CI]: 70.1% to 91.0%) and 84.9% (95% CI: 72.0% to 92.2%), respectively. The 5-year survivorship was 92.3% (95% CI: 78.0% to 97.5%) for stem length > 90 mm compared to 68.4% (95% CI: 39.5% to 85.7%) for stem length ≤ 90 mm. A construct-to-stem length ratio (CSR) ≤ 1 was associated with a 91.7% (95% CI: 76.4% to 97.2%) survival, while a CSR > 1 was associated with a 73.6% (95% CI: 47.4% to 88.1%) survival. CONCLUSION: A PFR stem length ≤ 90 mm and CSR > 1 were associated with increased rates of failure.