Meniscal Repair Outcome in 3829 Patients With a Minimum Follow-up From 2 Years Up to 5 Years: A Meta-analysis on the Overall Failure Rate and Factors Influencing Failure.

BACKGROUND: The importance of meniscal repair is widely accepted because of the association of loss of meniscal tissue with the development of early-onset knee arthritis. Many factors influencing the results of meniscal repair have been reported, but results remain controversial. PURPOSE: This meta-analysis determines the pooled meniscal repair failure rate of studies with a minimum follow-up of 2 years up to 5 years, with a mean follow-up of 43 months. Moreover, selected failure-influencing factors are analyzed. STUDY DESIGN: Systematic review and meta-analysis; Level of evidence, 4. METHODS: PubMed and Scopus were searched for studies published between January 2000 and November 2021 reporting on meniscal repair outcome with a minimum follow-up of 24 months. The overall pooled failure rate and pooled failure rates for possible predictors were calculated. Random-effect models were used to pool failure rates, and effect estimates in the form of odds ratios with 95% CIs were established. RESULTS: The initial literature search identified 6519 studies. A total of 51 studies met the inclusion criteria. In total, 3931 menisci were included with an overall failure rate of 14.8%. Subgroup analysis revealed a significantly lower failure rate for meniscal repair with concomitant anterior cruciate ligament (ACL) reconstruction compared with knees without any reported injury to the ACL (8.5% vs 14%; P = .043). The pooled failure rate for lateral meniscal repair was significantly lower than that for medial meniscal repair (6.1% vs 10.8%; P = .031). Pooled failure rates of all-inside and inside-out repair were not significantly different (11.9% vs 10.6%; P > .05). CONCLUSION: This meta-analysis on close to 4000 patients demonstrates an overall meniscal repair failure rate of 14.8% at a minimum follow-up from 2 years up to 5 years. Meniscal repair remains a procedure with a high failure rate, especially within the first 2 postoperative years. This review and meta-analysis also identified clinically relevant factors associated with favorable outcomes such as concomitant ACL reconstruction or repair of the lateral meniscus. All-inside meniscal repair with the latest-generation devices yields failure rates of <10%. The failure mechanism and the time of failure is poorly documented; further studies are needed for a better understanding of the retear mechanism.

Activity Following Total Hip Arthroplasty: Which Patients Are Active, and Is Being Active Safe?

BACKGROUND: Younger and physically active patients demand a return to sport after total hip arthroplasty (THA). However, because of the risk of implant wear and loosening, high-impact activities are often not recommended. The current study evaluates predictive factors and revision rates in patients with higher activity levels. METHODS: This retrospective study included 4152 hips in 3828 patients aged 45-75 that underwent primary THA for primary osteoarthritis between 2009 and 2019 with a minimum follow-up of 2 years. Pain and Lower Extremity Activity Scale (LEAS) were assessed before and 2 years after surgery. Activity was classified as low (LEAS 1-6), moderate (LEAS 7-13), or high (LEAS 14-18). RESULTS: Pain and LEAS improved from preoperative to 2-years postoperative (p < 0.001). The activity level was low in 6.2%, moderate in 52.9%, and high in 40.9% of the patients. Younger age, lower BMI, ASA, and CCI, male sex, and higher preoperative LEAS correlated with higher activity at 2 years (p < 0.001). The predicted revision-free survival rates between the activity groups were better for more highly active patients (p < 0.001). CONCLUSIONS: High physical activity 2 years following THA, with participating in sports like jogging several times a week, did not increase the risk of revision surgery. THA patients should not be prevented from a highly active lifestyle.

Predictors for activity following total and unicompartmental knee arthroplasty.

BACKGROUND: Functional demands of patients undergoing knee arthroplasty are increasing. However, it remains unclear which patient-specific factors have an impact on postoperative activity and whether there is a difference between total and unicompartmental knee arthroplasties (TKA/UKA). MATERIALS AND METHODS: This retrospective study analyzed 1907 knees with TKA (n = 1746) or UKA (n = 161), implanted for primary osteoarthritis. Pain and activity (lower extremity activity scale, LEAS) were assessed 2 years after surgery. High activity was defined as LEAS ≥ 14. Cohorts were compared using Kruskal-Wallis or Pearson-Chi-square test. A generalized least squares model was used to predict LEAS scores between cohorts adjusted for age, sex, BMI, Charlson Comorbidity Index, ASA score, and preoperative LEAS. RESULT: There was no difference in pain 2 years after surgery between UKA and TKA (p = 0.952). Preoperative LEAS was similar for UKA and TKA (p = 0.994), and both groups showed significant (p < 0.001 respectively) and similar improvements after surgery (p = 0.068). LEAS 2 years after surgery was 11.1 (SD 3.2) for TKA and 11.9 (SD 3.5) for the UKA group (p = 0.004). After adjusting for preoperative LEAS, age, sex, BMI, CCI and ASA, the difference was not significant (p = 0.225). Male sex, lower BMI, higher preoperative LEAS, and younger age were associated with higher postoperative LEAS (p < 0.001, respectively). CONCLUSION: Patients can achieve a high level of activity following both TKA and UKA. While the postoperative activity level did not depend on the type of the procedure, younger age, male sex, lower BMI, and a higher preoperative activity level were associated with a higher postoperative activity level.

Patella component diameters of 38 mm and up might be associated with higher revision rates after patella resurfacing.

PURPOSE: Patellar resurfacing is considered the standard of care for total knee arthroplasty in the USA. Complications of patella resurfacing include aseptic loosening or patella fractures and can threaten the integrity of the extensor mechanism. The goal of this study was to report on patella button revision rates in posterior stabilized total knee arthroplasty. MATERIAL AND METHODS: Between 01/2010 and 08/2016 patella buttons were implanted in 1056 patients (267 men and 550 women) as part of a posterior stabilized total knee arthroplasty. RESULTS: Of 1056 cases, 35 cases (14 women, 15 men, 5 bilateral, 3.3%) showed early loosening at a mean 52.5 months postoperatively. Patella components of 38 mm or larger diameters showed a significantly higher loosening rate than the 29, 32, 35 mm buttons (p < 0.01). Mean BMI of patients identified with aseptic loosening was 31.7 kg/m2, mean age at time of revision surgery was 63.3 years. All of the patients with loosening of the patella button required revision surgery; in 33 cases an exchange of the button was performed, in two cases a removal of the button and patellar bone grafting was indicated. No complications occurred after revision surgery. CONCLUSION: The current study reports a 3.3% patella loosening rate during this mid-term follow-up. Size 38 mm and larger patella components showed a significantly higher revision rate than smaller buttons and the authors advise caution when using large diameter patella components.

Does high activity after total and unicompartmental knee arthroplasty increase the risk for aseptic revision?

INTRODUCTION: It has been suggested that high activity might negatively impact implant survival following total and unicompartmental knee arthroplasty (TKA/UKA) and many surgeons advise their patients to only participate in moderate level sport activities. To date, it remains unclear whether such restraints are necessary to assure longevity of the implants. MATERIALS AND METHODS: We conducted a retrospective study on 1906 knees (1745 TKA, 161 UKA) in 1636 patients aged 45-75 years who underwent primary arthroplasty for primary osteoarthritis. Lower extremity activity scale (LEAS) at a two year follow-up was assessed to define the activity level. Cases were grouped in low (LEAS ≤ 6), moderate (LEAS 7-13) and high activity (LEAS ≥ 14). Cohorts were compared with Kruskal-Wallis- or Pearson-Chi2-Test. Univariate logistic regression was conducted to test for association between activity level at two years and later revisions. Odds ratio was reported and converted to predicted probability. A Kaplan-Meier curve was plotted to predict implant survival. RESULTS: The predicted implant survival for UKA was 100.0% at two years and 98.1% at five years. The predicted implant survival for TKA was 99.8% at two years, 98.1% at five years. The difference was not significant (p = 0.410). 2.5% of the UKA underwent revision, one knee in the low and three knees in the moderate activity group, differences between the moderate and high activity group were not significant (p = 0.292). The revision rate in the high activity TKA group was lower than in the low and moderate activity groups (p = 0.008). A higher LEAS two years after surgery was associated with a lower risk for future revision (p = 0.001). A one-point increase in LEAS two years after surgery lowered the odds for undergoing revision surgery by 19%. CONCLUSIONS: The study suggests that participating in sports activity following both UKA and TKA is safe and not a risk factor for revision surgery at a mid-term follow-up. Patients should not be prevented from an active lifestyle following knee replacement.

Is there a difference in mobility and inpatient physical therapy need after primary total hip and knee arthroplasty? A decade-by-decade analysis from 60 to 99 years.

INTRODUCTION: Extended inpatient rehabilitation (PT) after total hip (THA) and knee arthroplasty (TKA) has a significant impact on total care costs. As patients age, extended PT might be required following THA and TKA. This study examined the relationship between patient age, functional mobility, inpatient PT need, and discharge disposition in THA and TKA patients. MATERIALS AND METHODS: This retrospective study included patients aged 60 + undergoing primary THA or TKA between 2018 and 2020 at an orthopedic hospital. Comparing by age-decade, 7374 (3600 THA, 3774 TKA) sexagenarians, 5350 (2367 THA, 2983 TKA) septuagenarians, 1356 (652 THA, 704 TKA) octogenarians, and 78 (52 THA, 26 TKA) nonagenarians were analyzed. We compared the number of PT sessions needed for discharge clearance and the postoperative functional mobility using the Activity Measure for Post-Acute Care (AM-PAC) tool. Statistical analyses included ANOVA with post-hoc Tukey's HSD for continuous data and Chi-squared test for categorical variables. RESULTS: The number of PT sessions required for discharge clearance increased with age after THA (3.3 ± 1.9 sessions vs 3.8 ± 2.1 vs 5.0 ± 2.7 vs 6.2 ± 3.0; p < 0.01) and TKA (4.0 ± 2.1 vs 4.7 ± 3.1 vs 5.2 ± 2.8 vs 5.0 ± 1.6; p < 0.01). The functional mobility improvement as measured by AM-PAC was significantly lower for nonagenarians after THA (4.9 ± 2.8 vs 5.1 ± 2.8 vs 4.6 ± 3.3 vs 3.3 ± 3.9; p < 0.01) and TKA (5.0 ± 2.9 vs 4.7 ± 3.2 vs 3.9 ± 3.4 vs 3.2 ± 2.6; p < 0.01). CONCLUSION: Patients in their eighth and ninth decade had less improvement in functional mobility during in-hospital rehabilitation and utilized more PT services. However, clinical results in the elderly are still satisfying and the data may be helpful for resource utilization planning and risk-adjustment in value-based payment models.

Do cobalt and chromium blood metal ion levels normalize after revision of failed metal-on-metal total hip replacements?

INTRODUCTION: Increased cobalt (Co) and chromium (Cr) serum levels are one reason for revision surgery in metal on metal (MoM) total hip arthroplasty (THA) patients. Dual mobility liners are a simple revision option; however, they preserve the metal shell and stem and it is therefore not clear if metal ion levels will fully normalize after revision surgery. MATERIAL AND METHODS: Between April 2013 and December 2017 25 hips (24 patients) underwent revision from a MoM THA to an off-label dual mobility liner. Five patients were lost to follow-up and one patient refused leaving 18 patients (11 men, 7 female, average age 63.9 years) for pre- and postoperative metal ion level blood tests at a minimum follow-up of 2 years. RESULTS: Fourteen patients were revised for osteolysis, two for elevated metal ion levels and two for fluid or cysts around the femoral or acetabular component. The average preoperative Co and Cr levels were 8.3 µg/l and 5.0 µg/l, respectively. At a minimum follow-up of 2 years (30-95 months), metal ions dropped to 0.8 µg/l. Harris Hip Score (HHS), Hip Osteoarthritis Outcome Score (HOOS), Visual Analog Scale (VAS) and the UCLA activity score improved non-significantly from pre- to postoperative. There was one postoperative complication in the study cohort. One patient with persisting pain required revision surgery to a standard acetabular component during the follow-up period. CONCLUSION: The off-label use of a dual-mobility liner in the current study resulted in normalization of the metal ion levels suggesting that preserving the cobalt-chromium acetabular component has little impact on ion levels. In addition, dual mobility liners have a low complication and revision rate.

History of COVID-19 infection is not associated with increased D-dimer levels and risk of deep-vein thrombosis in total joint arthroplasty.

INTRODUCTION: In the acute phase of COVID-19, elevated D-dimer levels indicate a hypercoagulable state putting the patients at increased risk for venous thromboembolic disease (VTE). It is unclear, if prior COVID-19 disease increases the risk for VTE after total joint arthroplasty (TJA) and if D-dimer levels can be used to identify patients at risk. MATERIALS AND METHODS: D-Dimer levels of 313 consecutive SARS-CoV-2 IgG-positive and 2,053 -negative patients undergoing TJA between 05/20 and 12/20 were evaluated. D-Dimer levels were divided into three groups: < 200 ng/ml, 200-400 ng/ml, and > 400 ng/ml D-dimer units (DDU). 277 SARS-CoV-2 IgG-positive patients underwent a Doppler ultrasound to rule out deep-vein thrombosis (DVT) 4-6 weeks after TJA. RESULTS: D-Dimer levels did not differ significantly between SARS-CoV-2 IgG-positive and -negative patients (p value 0.53). Among SARS-CoV-2 IgG-negative patients, 1687 (82.17%) had D-dimer levels < 200 ng/ml, 256 (12.47%) between 200 and 400 ng/ml, and 110 (5.36%) > 400 ng/ml. Of the SARS-CoV-2 IgG-positive patients, 257 (83.71%) had D-dimer levels < 200 ng/ml, 34 (11.07%) between 200 and 400 ng/ml, and 16 (5.21%) > 400 ng/ml. A postoperative DVT was detected in nine patients (2.9%) in the SARS-CoV-2 IgG-positive group and a PE in one patient (0.3%). 7/229 patients with < 200 ng/ml (3.1%), 1/28 patients (3.6%) with 200-400 ng/ml and 1/9 patients (11.1%) with D-dimer levels > 400 ng/ml had a DVT or PE (p = 0.43). CONCLUSIONS: The findings of this investigation suggest there is no difference in D-dimer levels between SARS-CoV-2 IgG-positive and -negative patients undergoing TJA. Although there is a trend for increased VTE rates with increased D-dimer levels, routine D-dimer testing is not recommended based on the current data. SARS-CoV-2 IgG-positive patients have a low risk of VTE in the current study.

Sport after Knee Replacement Surgery - a Review of Sport Habits and Key Surgical Aspects. / Sport mit Knieprothese ­ Wieviel Sport ist möglich und was gilt es zu beachten ?

As an increasing number of younger patients are undergoing total knee replacement (TKR) surgery, many wish to participate in sport, but still expect that the implant will survive for a extended period. Most of the current literature shows that patients predominantly participate in low impact activities, both before and after surgery. A few studies show that with appropriate previous experience, high-impact sports are possible and might not result in increased implant failure rates. These include a decrease in point loads on the polyethylene by using more conform bearing surfaces, avoidance of varus component alignment to minimise stresses at the implant bone interface and avoiding patella resurfacing to facilitate activities in deep knee flexion.A TKR is no longer an absolute contraindication for higher impact activities such as golf, tennis and ski. What is more important than implant specific factors seem to be patient specific factors, including preoperative activity level, and preoperative sport skills.The current review paper reports on the current sport habits of TKR patients, analyses biomechanical loads on the knee during different sport activities and reports on implant selection and technical considerations for the active patient undergoing TKR.

Midterm results of the Birmingham hip resurfacing: a single-surgeon series.

INTRODUCTION: Birmingham hip resurfacing (BHR) is readily used as alternative to total hip replacement in younger patients. The current study aims to compare outcomes in terms of adverse local tissue reactions (ALTR), elevated metal ion levels and survival rates between low-risk (femoral component size ≥ 48 mm) and high-risk (femoral component size < 48 mm) BHR patients at a minimum 5-year follow-up (FU). MATERIALS AND METHODS: We report the minimum 5-year, single surgeon outcome results of 183 BHRs, performed between 2007 and 2012. 154 patients, 18 women (20 hips) and 136 men (163 hips) were included in the study. Patients were grouped in 149 low-risk cases (femoral component size ≥ 48 mm) and in 34 high-risk cases (18 female/12 male) patients with a femoral head size < 48 mm). RESULTS: At a minimum of 5-years FU time, 91% of the patients were available for FU. The overall survival rate was 91.8%. There were five revisions (survival rate 96.6%) in the low-risk group and ten revisions (survival rate 70.6%) in the high-risk group. In the low-risk group, six patients (6.5%) showed elevated metal ion levels (> 7 µg/l), compared to five patients (20.8%) in the high risk-group (p = 0.03). CONCLUSION: Including the surgeon's initial learning curve, the BHR shows very good mid-term survival rates in the low-risk group but should, as previously demonstrated, not be considered for patients with less than 48 mm femoral head size. LEVEL OF EVIDENCE: Level III: retrospective cohort study.

The impact of the COVID-19 associated shutdown on orthopedic patient care.

BACKGROUND: Due to the surge of COVID-19 cases in the US in early March 2020, health care facilities temporarily suspended elective and non-urgent medical procedures such as joint replacement surgeries. The aim of this study was to analyze the impact of the COVID-19 associated shutdown on orthopedic patient care at a specialized orthopedic hospital located at the epicenter of the COVID-19 pandemic. METHODS: Patient volume of outpatient visits and joint replacement surgeries were analyzed and compared for 2019 and 2020. The volumes were further aligned with the timeline of governmental and institutional COVID-19 associated restrictions. RESULTS: The annual surgery volume was reduced by 20.2% in 2020 and did not make up for the reduction experienced during the shutdown. The total number of patient visits decreased by 25.5% and new patient visits remained 25% lower at the end of 2020. Patient care and surgery volume recovered with declining SARS-CoV-2-cases but did not return to levels prior to the shutdown. During the second quarter of 2020, 28.5% of all patient visits were telehealth appointments. By the end of the year it dropped to 7.6%. There was a shift towards patient appointments at outpatient satellite offices. CONCLUSION: Orthopedic providers faced a substantial disruption in outpatient and surgical volume. Telemedicine appointments were crucial for maintaining follow-up patient care and will be an important sector in future patient care. There has been a major push to utilize satellite offices outside the city center.

Hip resurfacing and posterior approach total hip arthroplasty have equivalent blood loss when tranexamic acid is used: a propensity score matched cohort analysis.

INTRODUCTION: Hip resurfacing (HR) requires a larger approach and soft tissue dissection and might therefore be associated with increased blood loss compared to total hip arthroplasty (THA). However, the effect of the adoption of tranexamic acid (TXA) in this setting is unknown. Therefore, the current study compares the blood loss and transfusion requirements between HR and posterior THA in patients receiving TXA. MATERIALS AND METHODS: This retrospective cohort study included patients undergoing primary, unilateral THA or HR using a posterior approach between February 2016 and 2020 in which TXA was administered. THA and HR patients were propensity score matched using nearest neighbor greedy matching accounting for demographic, health and surgical variables. Postoperative hemoglobin (Hgb) levels and Hgb drop from preoperative to post-operative day (POD) 1 were compared using t-tests and associated risk factors were assessed using linear mixed modelling. RESULTS: After matching, each cohort consisted of 1395 patients. Cohorts were similar regarding age, sex, BMI, and Charlson Comorbidity Index. No significant differences were found for Hgb levels on POD 1 (12.3 g/dl; p = 0.90) or Hgb drop (2.3 g/dl; p = 0.87). Duration of surgery was significantly longer for HR patients (82 vs 77 min; p < 0.01). Transfusion rate was 0.1% in both cohorts (p = 1.00). Hospital stay was significantly shorter for HR patients (1 vs 2 days; p < 0.01). CONCLUSION: HR using a standard TXA regimen is not associated with greater perioperative blood loss than posterior THA and does not result in increased transfusion requirements. Both surgical procedures can be considered equally safe in terms of perioperative blood management when TXA is used.

Nineteen percent of meniscus repairs are being revised and failures frequently occur after the second postoperative year: a systematic review and meta-analysis with a minimum follow-up of 5 years.

PURPOSE: Meniscus repair has gained increasing interest over the last two decades as loss of meniscus tissue predisposes to early onset knee arthritis. Although there are many reports of meniscus repair outcome in short-term studies, data on the long-term outcome of meniscus repair are still scarce. The purpose of this meta-analysis was to evaluate the overall failure rate of meniscus repair with a minimum follow-up of 5 years. Additionally, possible factors influencing meniscus repair outcome were assessed. METHODS: PubMed and Scopus were searched for studies of the last 20 years reporting on meniscus repair outcome with a minimum follow-up of 5 years. The study was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The search terms used for this study were ([meniscus OR meniscal] AND repair). Titles and abstracts were evaluated by two authors independently. Using meta package of R (version 3.6.2), random-effect models were performed to pool failure rates. Subgroup analyses were performed and effect estimates in form of an odds ratio with 95% CIs were established. RESULTS: In total, 12 studies with 864 patients were included. Degenerative tears were excluded in two studies and one study only included traumatic meniscus tears. Other studies did not state whether the cause of meniscus tear was degenerative or traumatic. Studies reporting meniscus repair outcome on root repairs, revision anterior cruciate ligament reconstruction, discoid menisci or ramp lesions were excluded. Revision surgery was used as failure definition in all included studies. The overall failure rate of meniscal repair at a mean follow-up of 86 months was 19.1%. There was no significant difference in meniscus repair outcome when performed in combination with anterior cruciate ligament reconstruction compared to isolated meniscus repair (18.7% vs. 28%; n.s.) or when performed on the lateral meniscus compared to the medial meniscus (19.5% vs. 24.4%; n.s.). There was no significant difference of meniscus repair outcome between vertical/longitudinal tears and bucket-handle tears (n.s.). Thirty-six percent of meniscus repair failures occur after the second postoperative year. The only significant finding was that inside-out repair results in a lower failure rate compared to all-inside repair (5.6% vs. 22.3%; p = 0.009) at 5 years. CONCLUSION: The overall meniscus repair failure rate remains nineteen percent in long-term studies. The cause of failure is poorly documented, and it remains unclear whether failure of the meniscus repair itself or additional adjacent tears lead to revision surgery. Despite the given technical advantages of all-inside repair devices, this meta-analysis cannot demonstrate superior outcomes compared to inside-out or outside-in repair at 5 years. LEVEL OF EVIDENCE: IV.

Blood Management Following Total Joint Arthroplasty in an Aging Population: Can We Do Better?

BACKGROUND: To evaluate the transfusion rates for octogenarians and nonagenarians following total knee and hip arthroplasty (TKA, THA), we compared transfusion rates and associated risk factors among sexagenarians, septuagenarians, octogenarians, and nonagenarians. METHODS: This retrospective cohort study included 13,603 sexagenarians, 9796 septuagenarians, 2706 octogenarians, and 158 nonagenarians that received a primary, unilateral THA or TKA between 2016 and 2020 at a high-volume institution. Using multivariable logistic regression analysis, the study analyzed risk factors for postoperative transfusions including use of tranexamic acid (TXA) and compared preoperative and postoperative hemoglobin (Hgb) levels and the drop in Hgb. RESULTS: Nonagenarians had significantly higher transfusion rates (THA 25.5%, TKA 26.7%) than octogenarians (THA 9.9%, TKA 9.2%), septuagenarians (THA 3.3%, TKA 4.5%), and sexagenarians (THA 1.9%, TKA 2.9%) (P < .01). Significant risk factors for transfusion requirement following THA were American Society of Anesthesiologists level III (odds ratio [OR] 5.3, P < .01) and American Society of Anesthesiologists level IV (OR 8.0, P = .01), nonuse of TXA (intravenous: OR 0.3, P < .01; topical: OR 0.5, P < .01), lower preoperative Hgb levels (OR 0.4, P < .01), longer duration of surgery (OR 1.0, P < .01), and hepatopathy (OR 3.1, P < .01). Significant risk factors following TKA were nonuse of TXA (intravenous: OR 0.3, P < .01; topical: OR 0.5, P < .01; combined: OR 0.2, P < .01), lower preoperative Hgb levels (OR 0.4, P < .01), and longer surgery time (OR 1.0, P < .01). CONCLUSION: The strongest independent risk factors for increased transfusion rates among octogenarians and nonagenarians were lack of TXA application and lower preoperative Hgb levels. Routine TXA application and preoperative patient optimization are recommended to reduce transfusion rates in patients aged 80+.

D-Dimer Levels Are Not Elevated in SARS-CoV-2 IgG Positive Patients Undergoing Elective Orthopedic Surgery.

INTRODUCTION: In acute COVID-19, D-Dimer levels can be elevated and those patients are at risk for thromboembolic events. This study aims to investigate differences in preoperative D-Dimer levels in SARS-CoV-2 IgG positive and negative patients undergoing primary total knee and total hip replacement (TJA) or spine surgery. METHODS: D-Dimer levels of 48 SARS-CoV-2 IgG positive and 718 SARS-CoV-2 IgG negative spine surgery patients were compared to those of 249 SARS-CoV-2 IgG positive and 2102 SARS-CoV-2 IgG negative TJA patients. Patients were assigned into groups based on D-Dimer levels as follows: <200 ng/mL, 200-400 ng/mL, and >400 ng/mL D-Dimer Units (DDU). RESULTS: D-Dimer levels did neither differ significantly between SARS-CoV-2 IgG positive spine surgery patients and TJA patients (p = 0.1), nor between SARS-CoV-2 IgG negative spine surgery and TJA patients (p = 0.7). In addition, there was no difference between SARS-CoV-2 IgG positive and negative spine surgery patients and SARS-CoV-2 IgG positive and negative TJA patients (p = 0.3). CONCLUSIONS: There is no difference in D-Dimer levels between SARS-CoV-2 IgG positive and negative patients and there does not seem to be any difference for different orthopedic specialty patients. Routine testing of D-Dimer levels is not recommended for patients undergoing elective orthopedic surgery.

High Revision Rates of a Cementless Beta-Titanium Alloy Stem with Contamination-Free Roughened Surface in Primary Total Hip Arthroplasty.

Optimal osseointegration of cementless total hip arthroplasty is essential for high stability and long-term survival. The purpose of this follow-up study was to evaluate the clinical and radiological outcome, the complications, and survival rates of a beta-titanium alloy stem with a specific grit-blasted-free surface. In 192 patients (mean age of 64.4 years), 202 consecutive primary total hip arthroplasties were performed using a cementless Hipstar® stem (Stryker, Duisburg, DE). The Harris Hip Score (HHS) was assessed pre-operatively and post-operatively. Radiolucent lines were evaluated and the implant survival rate was calculated using Kaplan-Meier analysis. The mean follow-up was 7.71 years (range of 5.0-14.0 years). Overall, 15 revisions were performed. Early aseptic stem loosening was observed in six cases (2.97%). Radiolucent-lines adjacent to the stem were detected in 73 cases (83.02%), especially (70.46%) in the Gruen zones 1, 7, 8, and 14. The mean postoperative HHS was 92.65 points (range 42-100). The cumulative survival probability of the stem was 94.4% (95% CI 90.3 to 98.5%). Considering aseptic failure as an endpoint, the cumulative survival rate of the stem was 95.3% (95% CI 0.914 to 0.992) at six years of follow-up. Overall, an inferior mid-term implant survival was observed in comparison to well-established cementless stem designs.

Sport and Physical Activity Following Primary Total Knee Arthroplasty: A Systematic Review and Meta-Analysis.

BACKGROUND: This systematic review and meta-analysis aims to analyze the sport habits of patients before and after primary total knee arthroplasty (TKA) by answering the following questions: (1) Is there a postoperative improvement of sport activity based on validated activity scores? (2) Does age influence the postoperative improvement of sport activity based on validated activity scores? (3) What are the preoperative and postoperative sport participation rates and the return to sport rates (RTS)? (4) What are the sport disciplines and sport patterns? METHODS: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, MEDLINE and Scopus were searched for studies reporting the physical activity level and sport habits of patients before and after primary TKA based on validated activity scores or an activity questionnaire. Random effect models were implemented to pool the mean differences (MDs) of activity score values and the difference between preoperative and postoperative sport participation rates. RESULTS: Twenty-five studies were included reporting on 6035 TKAs. Physical activity levels improved significantly according to the University of California, Los Angeles (UCLA) activity score (MD 1.55, 95% confidence interval [CI] 0.35-2.76, n = 1239, I2 = 99%, P < .01) and the Tegner score (MD 1.14, 95% CI -0.48 to 2.76, n = 483, I2 = 93%, P < .01). Younger patients (≤55 years) had the highest improvement in the UCLA activity scores following primary TKA (MD 3.12, 95% CI -1.79 to 8.04, n = 67, I2 = 96%, P < .01). Sport participation decreased slightly but not significantly (incidence rate difference -8%, 95% CI -0.14 to -0.2, n = 2673 patients, I2 = 38%, P = .09). The median RTS was 71.2%. Patients predominantly engaged in low-impact sports, especially walking, cycling, and swimming. CONCLUSION: According to validated activity scores, the level of physical activity significantly increases following primary TKA. Young patients (≤55 years) had the highest gain in physical activity according to the UCLA activity score following primary TKA. Sport participation shows a slight but nonsignificant decrease; intermediate and high-impact sports were abandoned to a large degree while participation rates for low-impact sports predominantly increased. RTS varied, although approximately 70% resume sport activities. LEVEL OF EVIDENCE: IV (review including case series).