Use of Hinged Implants for Multistage Revision Knee Arthroplasty for Severe Periprosthetic Joint Infection: Remission Rate and Outcomes After a Minimum Follow-Up of 5 Years.

BACKGROUND: In severe periprosthetic joint infection after total knee arthroplasty (TKA), multistage procedures are indicated for ongoing signs of infection after implant removal during the spacer interval of an intended 2-stage exchange. In these cases, several additional debridement and spacer exchange surgeries may be necessary. Herein, we analyzed the complications, remission rates, and functional outcomes after multistage revision arthroplasty using hinged TKAs. METHODS: Patients (n = 79) treated with multistage revision arthroplasty after chronic periprosthetic joint infection of the knee were included (2010 to 2018). During the prosthesis-free interval, a static spacer containing antibiotic-loaded bone cement was implanted. The mean number of surgeries, including implant removal and revision arthroplasty, was 3.8 (range, 3 to 8). The mean duration from implant removal to revision arthroplasty was 83 days (range, 49 to 318). Complications, remission, and mortality were analyzed after a minimum follow-up of 5 years. Outcomes were assessed based on the Knee Society Score (KSS) and the Western Ontario McMasters University Osteoarthritis Index. RESULTS: During follow-up, 24 (30.4%) patients underwent revision surgery, with a mean time to surgical revision of 99 weeks (range, 1 to 261). After follow-up, the infection-free remission rate and overall mortality were 87.3 and 11.4%, respectively. The mean KSS was 74.3 (range, 24 to 99), the KSS Function Score was 60.8 (range, 5 to 100), and the Western Ontario McMasters University Osteoarthritis Index 30.2 (range, 5 to 83). CONCLUSIONS: In difficult-to-treat cases, multistage revision arthroplasty showed high remission rates and low mortality after a follow-up of 5 years. The overall revision rate was comparably high, accounting for early and late reinfections most of the time. In cases of implant survival, functional outcomes comparable to those of revision hinge TKA reported in the literature can be achieved. Therefore, multistage procedures with additional debridement steps should be performed in cases of ongoing infections in intended 2-stage procedures.

Mid-term outcome following radial head arthroplasty in acute trauma: risk factors for poor outcome.

BACKGROUND: The aims of this study were to evaluate the outcomes of a single type of radial head implant in a large cohort of patients at mid-term follow-up and to determine the associated risk factors for inferior functional outcomes. METHODS: We performed a retrospective follow-up assessment of 65 patients (33 women and 32 men; mean age, 53.3 years [range, 22-81 years]) who underwent radial head arthroplasty (RHA) for acute trauma between 2012 and 2018, after a minimum follow-up period of 3 years. The Mayo Elbow Performance Score, Oxford Elbow Score, Disabilities of the Arm, Shoulder and Hand score, and Mayo Modified Wrist Score were evaluated, and all available radiographs were analyzed. All complications and revision procedures were assessed. Bivariate and multivariate regression analyses were performed to identify potential risk factors for a poor outcome following RHA. RESULTS: After an average follow-up period of 4.1 years (range, 3-9.4 years), the mean Mayo Elbow Performance Score was 77.2 (standard deviation [SD], 18.9); mean Oxford Elbow Score, 32.0 (SD, 10.6); mean Mayo Modified Wrist Score, 74.6 (SD, 13.7); and mean Disabilities of the Arm, Shoulder and Hand score, 29.0 (SD, 21.2). Average range of motion measured 10° (SD, 15°) in extension, 125° (SD, 14°) in flexion, 81° (SD, 14°) in pronation, and 63° (SD, 24°) in supination. The overall complication and reoperation rates were 38.5% and 30.8%, respectively, with severe elbow stiffness being the most common reason for revision. Patient age >50 years, the use of an external fixator, the presence of accompanying medial collateral ligament injuries, and the development of higher-grade osteoarthritis were associated with a poor outcome. CONCLUSION: Satisfactory medium-term outcomes can be achieved using a monopolar, long-stemmed RHA in patients with acute trauma. However, complication and revision rates are high, frequently leading to inferior outcome scores. Additionally, a higher patient age, the use of an external fixator, the presence of accompanying medial collateral ligament injuries, and the occurrence of higher-grade osteoarthritis were associated with a poor outcome; these factors should raise awareness by the treating trauma surgeon.

Arthroscopic Bankart repair: how many knotless anchors do we need for anatomic reconstruction of the shoulder?-a prospective randomized controlled study.

PURPOSE: The optimal strategy for surgical repair of traumatic anterior shoulder instability remains controversial. While several study groups have reported that the clinical and radiological outcomes of arthroscopic procedures performed with two anchors are not fully adequate, these conclusions are not supported by the findings published in other studies. A prospective randomized study was conducted to compare the structural and clinical outcomes of surgical procedures involving two vs. three anchors. METHODS: Patients who underwent arthroscopic Bankart repair were randomly assigned to either Group I, which underwent procedures involving two double-loaded 3.5-mm knotless anchors, or Group II, which underwent procedures involving three single-loaded 2.9-mm knotless anchors. All patients underwent bilateral MRI assessments at a minimum of 12 months and clinical assessment at a minimum of 24 months postoperatively. To evaluate the reconstruction of the labral capsular ligamentous complex (LCLC), the labrum-glenoid height index (LGHI), restored labral height (LH), and labral slope (LS) were measured for both shoulders. For clinical assessment, the redislocation rate and functional outcome scores (Constant score (CS), American Shoulder and Elbow Surgeon score (ASES), Walch Duplay score (WDS), and Rowe score (RS)) were evaluated at follow-up visits. RESULTS: Bankart repair with two knotless anchors showed lower values for anterior reconstruction of the LCLC compared to the uninjured contralateral shoulder. Likewise, significant differences were noted when comparing these measurements to those from patients who underwent reconstruction with three anchors. No differences were demonstrated with regard to the reconstruction of the inferior LCLC. Clinical assessment showed good to excellent results in both groups. In total, three patients experienced redislocation of the shoulder: two in group I and one in group II. No significant differences were found with respect to clinical outcomes and redislocation rates. CONCLUSION: Bankart repair with both two and three knotless anchors results in effective anatomical reconstruction of the labral capsular ligamentous complex. Although the two-anchor technique yields significantly lower values for the anterior portion compared with the contralateral side, none of these differences reach clinical relevance as per our original definition.

Coronoid tip fractures in terrible triad injuries can be safely treated without fixation.

INTRODUCTION: The optimal treatment of terrible triad injuries of the elbow (TTI) remains topic of ongoing discussion. The aim of this study was to determine whether different treatment strategies for coronoid tip fractures in terrible triad injuries influences the clinical and radiological results in a mid-term follow-up. METHODS: A total of 62 patients with surgical treatment of a TTI including a coronoid tip fracture (37 women, 25 men; mean age, 51 years) were available for follow-up assessment after an average of 4.2 years (range 24-110 months). Thirteen patients had O'Driscoll 1.1 and 49 O'Driscoll 1.2 coronoid fractures, of which 26 were treated with and 36 without fixation. Range of motion, the Mayo Elbow Performance Score (MEPS), Oxford Elbow Score (OES), and Disabilities of the Arm, Shoulder and Hand (DASH) score as well as grip strength were evaluated. Radiographs were analyzed for all participants. RESULTS: No significant benefit in outcome variables could be detected between patients, whose coronoid had been fixed, compared to patients without fixation of the coronoid. In the coronoid fixation group, patients had mean outcome scores of 81.5 ± SD 19.1 (range 35-100) for MEPS, 31.0 ± SD 12.5 (range 11-48) for OES and 27.7 ± SD 23 (range 0-61) for DASH score, while in the no-fixation group, mean MEPS was 90.8 ± SD 16.5 (range 40-100), mean OES was 39.0 ± SD 10.4 (range 16-48) and mean DASH score was 14.5 ± SD 19.9 (range 0-48). Mean range of motion was 116° ± SD 21° (range 85-140°) versus 124° ± SD 24° (range 80-150°) in extension-flexion and 158° ± SD 23° (range 70-180°) versus 165° ± SD 12° (range 85-180°) in pronation-supination. Overall complication rate was 43.5% and revision rate was 24.2%, with no significant differences between both groups. Suboptimal results were more frequently seen in patients who had degenerative or heterotopic changes on their latest radiograph. CONCLUSIONS: Sufficient elbow stability and good outcomes can be achieved in most patients with TTI and coronoid tip fractures. Although some bias in treatment allocation and group heterogeneity cannot be completely omitted, our analysis detected no significant benefit in outcome when the coronoid tip fracture has been fixed compared to patients with non-fixed coronoid tip. Therefore, we would suggest a no-fixation approach for coronoid tip fractures as primary treatment in TTI of the elbow. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Value of closed suction drainage in arthroscopic and minimally invasive surgery of the ankle joint: a prospective randomised study.

INTRODUCTION: Closed suction drainage is an established procedure in arthroscopic surgery. It is intended to reduce the retention of wound and irrigation fluids, which form the basis for postoperative swelling, pain, and infection. However, currently, there is no scientific review of the actual benefit of this procedure. METHODS: Between 2020 and 2021, 84 patients (53 males, 31 females; mean age: 42 years) were prospectively randomised into this study. The patients underwent arthroscopic surgery of the ankle joint with (group A) or without (group B) insertion of a closed suction drain (42 patients per group). Assessments included upper ankle swelling using the figure-of-eight-20 method, pain preoperatively and 48 h postoperatively, and unexpected events within 6 weeks postoperatively. RESULTS: The measurements performed 48 h postoperatively showed a mean circumferential increase of 1.38 cm (1.48 and 1.28 cm in groups A and B, respectively; p > 0.05) in all patients. The mean pain at rest, assessed using the visual analogue scale (maximum 10 points), was 2.7 and 2.4 in groups A and B, respectively (p > 0.05). Overall, two minor complications occurred: residual swelling in group A and persistent limitation of movement in group B. The average length of hospital stay was 2.4 days (p > 0.05). CONCLUSIONS: Based on the available data, the routine insertion of a closed suction drainage at the upper ankle does not offer any objective benefit and must be considered obsolete. From both a medical and an economic point of view, the decision to conduct this procedure should be justified on an individual basis. LEVEL OF EVIDENCE: Level I, prospective randomised trial.

Tissue sampling is non-inferior in comparison to sonication in orthopedic revision surgery.

BACKGROUND: The aim of this study was to assess the role of sonication fluid cultures in detecting musculoskeletal infections in orthopedic revision surgery in patients suspected of having peri-prosthetic joint infection (PJI), fracture-related infections (FRI), or postoperative spinal implant infections (PSII). METHODS: Between 2016 and 2019, 149 cases with a data set including sonication fluid cultures and tissue specimen and histological analysis were included. Accuracy of each diagnostic tool as well as the influence of antibiotic therapy was analyzed. Pathogens identified in the sonication cultures and in the associated tissue samples were compared based on the matching of the antibiograms. Therapeutic benefits were then assessed. RESULTS: Of 149 cases, 43.6% (n = 65) were identified as PJI, 2.7% (n = 4) as FRI, 12.8% (n = 19) as PSII, 6.7% (n = 10) as aseptic non-union, and 34.2% (n = 51) as aseptic implant loosening. The sensitivity and specificity of tissue and synovial specimens showed no significant difference with respect to sonication fluid cultures (sensitivity/specificity: tissue: 68.2%/96.7%; sonication fluid cultures: 60.2%/98.4%). The administration of antibiotics over 14 days prior to microbiological sampling (n = 40) resulted in a lower sensitivity of 42.9% each. Histological analysis showed a sensitivity 86.3% and specificity of 97.4%. In 83.9% (n = 125) of the cases, the results of sonication fluid cultures and tissue specimens were identical. Different microorganisms were found in only four cases. In 17 cases, tissue samples (n = 5) or sonication (n = 12) were false-negatives. CONCLUSION: Sonication fluid culture showed no additional benefit compared to conventional microbiological diagnostics of tissue and synovial fluid cultures. Preoperative administration of antibiotics had a clearly negative effect on microbiologic test accuracy. In over 83.9% of the cases, sonication fluid and tissue cultures showed identical results. In the other cases, sonication fluid culture did not further contribute to the therapy decision, whereas other factors, such as fistulas, cell counts, or histological analysis, were decisive in determining therapy.

[Inpatient and Outpatient Treatment in the German Social Accident Insurance]. / Stationäre und ambulante Heilverfahren der Deutschen Gesetzlichen Unfallversicherung.

It is one objective of German Social Accident Insurance (DGUV) to restore the health and performance of insured persons after an accident "using all appropriate methods". Because of the legal requirements, possible rehabilitation may greatly differ from that provided by sickness or pension insurance. This article provides an overview of the available treatments after accidents at work and the rehabilitation phase in which they may be used.

[Reduction in Earning Capacity (MdE) Statutory Accident Insurance]. / Minderung der Erwerbsfähigkeit (MdE) in der gesetzlichen Unfallversicherung.

Changes in the employment market and improvements in the current prosthetic treatment have encouraged German Statutory Health Insurance e. V. (DGUV) to re-examine the standard values for reduced earning capacity after work related accidents. The new standard values for reduced earning capacity came into force on 01.11.2019. The present article summarises the consensus paper of the group of independent experts.

Molecular Assessment of Staphylococcus Aureus Strains in STAT3 Hyper-IgE Syndrome Patients.

Hyper-IgE syndromes (HIES) are a group of inborn errors of immunity (IEI) caused by monogenic defects such as in the gene STAT3 (STAT3-HIES). Patients suffering from HIES show an increased susceptibility to Staphylococcus aureus (S. aureus) including skin abscesses and pulmonary infections. To assess if the underlying immune defect of STAT3-HIES patients influences the resistance patterns, pathogenicity factors or strain types of S. aureus. We characterized eleven S. aureus strains isolated from STAT3-HIES patients (n = 4) by whole genome sequencing (WGS) to determine presence of resistance and virulence genes. Additionally, we used multi-locus sequence typing (MLST) and protein A (spa) typing to classify these isolates. Bacterial isolates collected from this cohort of STAT3-HIES patients were identified as common spa types in Germany. Only one of the isolates was classified as methicillin-resistant S. aureus (MRSA). For one STAT3 patient WGS illustrated that infection and colonization occurred with different S. aureus isolates rather than one particular clone. The identified S. aureus carriage profile on a molecular level suggests that S. aureus strain type in STAT3-HIES patients is determined by local epidemiology rather than the underlying immune defect highlighting the importance of microbiological assessment prior to antibiotic treatment.

Autonomous role of medullary thymic epithelial cells in central CD4(+) T cell tolerance.

Medullary thymic epithelial cells (mTECs) serve an essential function in central tolerance by expressing peripheral-tissue antigens. These antigens may be transferred to and presented by dendritic cells (DCs). Therefore, it is unclear whether mTECs, in addition to being an antigen reservoir, also serve a mandatory function as antigen-presenting cells. Here we diminished major histocompatibility complex (MHC) class II on mTECs through transgenic expression of a 'designer' microRNA specific for the MHC class II transactivator CIITA (called 'C2TA' here). This resulted in an enlarged polyclonal CD4(+) single-positive compartment and, among thymocytes specific for model antigens expressed in mTECs, enhanced selection of regulatory T cells (T(reg) cells) at the expense of deletion. Our data document an autonomous contribution of mTECs to both dominant and recessive mechanisms of CD4(+) T cell tolerance and support an avidity model of T(reg) cell development versus deletion.

Proximal ulna non-union: treatment concept and postoperative outcome.

PURPOSE: Non-union of the proximal ulna is a serious complication after surgical treatment of olecranon and complex elbow fractures, frequently leading to poor functional outcome. To date, there is a lack of data regarding optimal treatment strategies and functional outcome parameters after surgical revision. METHODS: From 02/2010 to 12/2018, 31 patients undergoing surgical treatment of proximal ulna non-union could be included. Follow-up period was seven years (SD 2.5 years). All patients were clinically assessed using a clinical assessment tool set and standard elbow scores (MEPS, OES, DASH score). All complications and unplanned revision surgeries were recorded and all radiographic material was analyzed. RESULTS: Initial non-union procedures were performed at an average of 6.6 months (SD 3 months) after the index procedures. Those included the use of autologous spongiosa graft in all patients and concomitant compression re-osteosynthesis in 28 patients. Radiological consolidation was achieved in all patients. Overall, patients achieved a good to fair functional outcome with Mayo elbow performance score measuring 78.5 (SD 9.1), DASH score 34.7 (SD 14.4), and Oxford elbow score 31.2 (SD 6.6) points. Initial malreduction/implant-malposition could be identified as a main reason for the occurrence of the non-union. Furthermore, inferior postoperative outcome was detected in patients > 60 years and BMI > 30 kg/m2. CONCLUSION: Using a standardized protocol, bony union and acceptable functional outcomes can be achieved in proximal ulna non-unions. However, surgeons should be aware of potential risk factors and proper initial fracture reduction as key to achieve sufficient bone healing.

Comminuted AO-C3 fractures of the patella: good outcome using anatomically contoured locking plate fixation.

PURPOSE: The treatment of comminuted patellar fractures remains a challenge for orthopedic surgeons. The aim of this study was to assess the clinical, functional, and radiological outcome after treatment of comminuted patellar fractures using an anatomically contoured plating system. METHODS: Between January 2015 and December 2019 (5 years), 29 patients with complex C3 fractures according to AO classification (18 female, 11 male; mean age: 53 years) were treated using an anatomically contoured plating system (patella SuturePlate™, Arthrex®, Naples, USA). Indication for surgery was based on instability and/or initial fragment dislocation (> 2 mm). After a minimum follow-up of 12 months, patients were examined using a standardized clinical examination and functional outcome was assessed using specific knee scores (Lysholm, WOMAC, IKDC, Kujala, and Tegner score). In addition, complications were recorded and all available radiographs were evaluated regarding osteoarthritis and reduction quality. RESULTS: All patients returned for follow-up investigation after an average of 19 months (range: 12-48 months). A mean range of motion (ROM) of 131° (range: 100-150) was recorded. Overall good functional outcome parameters could be reported, with a mean Lysholm score of 84.7 (range: 100-45), a WOMAC of 5.1 (range: 0-19.2), a Kujala scale of 85.5 (range: 100-48), an IKDC of 76.6 (range: 100-44.8), and a Tegner score of 4.3 (range: 10-3) with a difference of 0.62 to pre-operative. Patient satisfaction was rated 8.4 (range: 4-10) using a VAS. No loss of reduction, mechanical failure, or implant complications were detected. Radiological follow-up showed no evidence of relevant post-traumatic retropatellar osteoarthritis. In 7 cases, implants were removed due to subjective mechanical irritation. CONCLUSION: Anatomically contoured patellar plates allow secure fixation of the fracture fragments even in comminuted cases. Especially when tension-band wiring is prone to early failure, locking plate fixation represents a viable option leading to good functional results and low complication rates.

Superiority of upper ankle arthrodesis over total ankle replacement in the treatment of end-stage posttraumatic ankle arthrosis.

PURPOSE: Surgical treatment of end-stage posttraumatic upper ankle arthrosis is challenging. Highly variable revision rates have been reported with total ankle arthroplasty (TAA) of the upper ankle joint. The aim of this retrospective study was to compare revision rates with tibiotalar arthrodesis (TTA) and TAA with a prosthesis to determine the superior treatment approach. METHODS: Data for 148 patients (96 males and 52 females) with end-stage posttraumatic upper ankle arthrosis-including 88 treated with TTA and 60 with TAA between 2008 and 2013, with a mean follow-up of 59 months-were analysed. Bone fusion was confirmed by x-ray radiography and computed tomography. RESULTS: The overall revision rate was 28%; the rate was higher with TAA (42%) than with TTA (18%). The TAA group showed an increase in revisions from 12- to 24-month postsurgery. The most common cause of revision in the TAA group was cysts (20%), and the most frequent reason for revision was nonunion (8%). Mean American Orthopaedic Foot and Ankle Society (AOFAS) and Foot and Ankle Outcome (FAO) scores in all patients were 55.5 and 53.1, respectively, with no significant difference between the TTA and TAA groups (p > 0.05). In nine cases (15%) the prosthesis was explanted or converted to TTA. TAA patients who underwent conversion to TTA had worse outcomes (AOFAS score = 39; FAO score = 35.29). CONCLUSION: TAA is associated with a high rate of revisions, especially from the 2nd year postsurgery. Therefore, TTA is the treatment of choice for end-stage posttraumatic upper ankle arthrosis. Level of evidence Level III, comparative series.

Treatment of grossly dislocated supracondylar humerus fractures after failed closed reduction: a retrospective analysis of different surgical approaches.

INTRODUCTION: The supracondylar humerus fracture (SCHF) is one of the most common pediatric injuries. Highly displaced fractures can be very challenging. If closed reduction fails, the therapy algorithm remains controversial. MATERIALS AND METHODS: In total, 41 patients (21 boys and 20 girls) with irreducible Gartland type III SCHF, treated with open reduction through three different approaches and cross-pin fixation, were retrospectively evaluated. The mean follow-up was 46 months (min.: 12, max.: 83, SD: 23.9). The Mayo elbow performance score (MEPS) as well as the quick disabilities of arm, shoulder and hand (qDASH) score were used to assess the functional outcome. Baumann's angle and the anterior humeral line (AHL, Roger's line) were obtained from follow-up radiographs. Time to surgery, postoperative nerve-palsy, rate of revision surgery, and complication rate were examined. RESULTS: Two revision surgeries were reported. One due to inadequate reduction and one due to secondary loss of reduction. In this context, the AHL was a sufficient tool to detect unsatisfactory reduction. According to the MEPS the functional outcome was excellent (> 90) in 37/41 patients and good (75-89) in 4/41 at the final visit. Fair or poor results were not documented. The qDASH score was 1.8 (min.: 0, max.: 13.6, SD: 3.4). There were no significant differences between the utilized surgical approaches. An iatrogenic injury of the ulnar nerve was not reported in any case. Overall, one heterotopic ossification without impairment of the range of motion and one preliminary affection of the radial nerve were documented. CONCLUSION: In the rare case of an irreducible SCHF, an anatomical reduction can be achieved by open approaches with excellent functional outcome and a high grade of patient satisfaction. All described open approaches can be utilized with a high safety-level.

Sustained cellular immunity in adults recovered from mild COVID-19.

Transient lymphocytopenia is frequently observed in acute phase of coronavirus disease 2019 (COVID-19). It remains a concern whether impairment of cellular immunity may be retained after COVID-19. Here, we demonstrate by extensive lymphocyte profiling in 44 adults after mild COVID-19 that cellular immunity is not fundamentally altered in convalescent patients. Except for increased activated CD8+ lymphocytes, total counts of B, T, and NK cells and their subsets did not differ significantly between patients after COVID-19 and healthy controls after a median of 27 days (range 13-45) suggesting no residual cellular immune deficiency after recovery from mild COVID-19.

Performance of antigen testing for diagnosis of COVID-19: a direct comparison of a lateral flow device to nucleic acid amplification based tests.

OBJECTIVES: The gold standard for diagnosing an infection with SARS-CoV-2 is detection of viral RNA by nucleic acid amplification techniques. Test capacities, however, are limited. Therefore, numerous easy-to-use rapid antigen tests based on lateral flow technology have been developed. Manufacturer-reported performance data seem convincing, but real-world data are missing. METHODS: We retrospectively analysed all prospectively collected antigen tests results performed between 23.06.2020 and 26.11.2020, generated by non-laboratory personnel at the point-of-care from oro- or nasopharyngeal swab samples at the University Hospital Augsburg and compared them to concomitantly (within 24 h.) generated results from molecular tests. RESULTS: For a total of 3630 antigen tests, 3110 NAAT results were available. Overall, sensitivity, specificity, NPV and PPV of antigen testing were 59.4%, 99.0%, 98.7% and 64.8%, respectively. Sensitivity and PPV were lower in asymptomatic patients (47.6% and 44.4%, respectively) and only slightly higher in patients with clinical symptoms (66.7% and 85.0%, respectively). Some samples with very low Ct-values (minimum Ct 13) were not detected by antigen testing. 31 false positive results occurred. ROC curve analysis showed that reducing the COI cut-off from 1, as suggested by the manufacturer, to 0.9 is optimal, albeit with an AUC of only 0.66. CONCLUSION: In real life, performance of lateral-flow-based antigen tests are well below the manufacturer's specifications, irrespective of patient's symptoms. Their use for detection of individual patients infected with SARS-CoV2 should be discouraged. This does not preclude their usefulness in large-scale screening programs to reduce transmission events on a population-wide scale.

High-resolution pediatric reference intervals for 15 biochemical analytes described using fractional polynomials.

OBJECTIVES: Assessment of children's laboratory test results requires consideration of the extensive changes that occur during physiological development and result in pronounced sex- and age-specific dynamics in many biochemical analytes. Pediatric reference intervals have to account for these dynamics, but ethical and practical challenges limit the availability of appropriate pediatric reference intervals that cover children from birth to adulthood. We have therefore initiated the multi-center data-driven PEDREF project (Next-Generation Pediatric Reference Intervals) to create pediatric reference intervals using data from laboratory information systems. METHODS: We analyzed laboratory test results from 638,683 patients (217,883-982,548 samples per analyte, a median of 603,745 test results per analyte, and 10,298,067 test results in total) performed during patient care in 13 German centers. Test results from children with repeat measurements were discarded, and we estimated the distribution of physiological test results using a validated statistical approach (kosmic). RESULTS: We report continuous pediatric reference intervals and percentile charts for alanine transaminase, aspartate transaminase, lactate dehydrogenase, alkaline phosphatase, γ-glutamyl-transferase, total protein, albumin, creatinine, urea, sodium, potassium, calcium, chloride, anorganic phosphate, and magnesium. Reference intervals are provided as tables and fractional polynomial functions (i.e., mathematical equations) that can be integrated into laboratory information systems. Additionally, Z-scores and percentiles enable the normalization of test results by age and sex to facilitate their interpretation across age groups. CONCLUSIONS: The provided reference intervals and percentile charts enable precise assessment of laboratory test results in children from birth to adulthood. Our findings highlight the pronounced dynamics in many biochemical analytes in neonates, which require particular consideration in reference intervals to support clinical decision making most effectively.

The projected volume of primary and revision total knee arthroplasty will place an immense burden on future health care systems over the next 30 years.

PURPOSE: Total knee arthroplasty (TKA) rates have increased substantially in the recent decades worldwide, with Germany being one of the leading countries in the prevalence of TKA. The aim of this study was to provide an overview of treatment changes during the last decade and to project the expected burden of primary and revision TKA (rTKA) for the next 30 years. METHODS: Comprehensive nationwide data from Germany was used to quantify primary and revision TKA rates as a function of age and gender. Projections were performed with use of a Poisson regression models and a combination of exponential smoothing and autoregressive integrated moving average models on historical procedure rates in relation to official population projections from 2020 to 2050. RESULTS: The incidence rate of primary TKAs is projected to increase by around 43% to 299 per 100,000 inhabitants [95% CI 231-368], leading to a projected total number of 225,957 primary TKAs in 2050 (95% CI 178,804-276,442). This increase has been related to a growing number of TKA performed in male patients, with the highest increase modelled in patients between 50 and 65 years of age. At the same time, the annual total number of revision procedures is forecast to increase even more rapidly by almost 90%, accounting for 47,313 (95% CI 15,741-78,885; IR = 62.7 per 100,000, 95% CI 20.8-104.5) procedures by 2050. Those numbers are primarily associated with a rising number of rTKAs secondary to periprosthetic joint infection (PJI). CONCLUSIONS: Using this country- specific forecast approach, a rising number of primary TKA and an even more rapidly growing number of rTKA, especially for PJI, has been projected until 2050, which will inevitably provide a huge challenge for the future health care system. As many other industrialized nations will face similar demographic and procedure-specific developments, these forecasts should be alarming for many health care systems worldwide and emphasize the tremendous need for an appropriate financial and human resource management in the future. LEVEL OF EVIDENCE: Level III, prognostic study, economic and decision analysis.

Epidemiology and Treatment of Radial Head Fractures: A Database Analysis of Over 70,000 Inpatient Cases.

PURPOSE: We aimed to study the epidemiology of radial head fractures within a single national registry database while analyzing trends in available treatments. METHODS: A retrospective analysis of data from 2007 to 2016 provided by a national inpatient database registry was performed using the International Classification of Diseases code for radial head fractures and associated German Procedure Classification (OPS) codes. All surgical interventions were evaluated according to fracture type, patient sex and age, and distribution differences over the last decade to detect changes in the treatment trends. The number of major revision procedures was identified and the revision burden for each procedure calculated. RESULTS: Overall, 70,118 radial head fractures were included, with the annual number rising over 20% during this period. Women were significantly older than men (peak incidence, 55-64 years vs 30-39 years) and more frequently injured (women-to-men, 1.3:1). Surgical interventions increased during the study period, with locking plate fixation of comminuted fractures and radial head arthroplasty (RHA) becoming increasingly performed while radial head resections decreased. The revision burden differed significantly between the fixation techniques, with an increased occurrence of RHA revision procedures more recently. CONCLUSIONS: The data show a higher number and incidence of surgical procedures, especially for comminuted radial head fractures over the study period. Open reduction and internal fixation remains the most frequently used option, with the use of new fixation devices (eg, locking plates) increasing. The use of RHA more than doubled over the past 10 years while the number of radial head resections decreased. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic II.

Secondary reconstruction of chronic Achilles tendon rupture: flexor hallucis longus transfer versus plantaris longus augmentation.

INTRODUCTION: Chronic Achilles tendon rupture is primarily caused by degenerative processes of multifactorial origin. In addition to secondary repair (SR) with augmentation of the plantaris longus tendon, the transfer of the flexor hallucis longus tendon (FHL) to the calcaneus is a recognised reconstruction procedure. This paper aims to provide a direct comparison based on clinical scores and objectifiable strength measurements. METHODS: We analysed data for 60 patients (46 males and 14 females) with chronic Achilles tendon rupture, including 34 (mean age 57 years) treated with FHL and 26 (mean age 52 years) with SR between 2016 and 2020 (mean follow-up of 49 months). The follow-up included the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scoring System (AOFAS-AH) and Visual Analogue Scale Foot and Ankle (VAS FA), the 12-item Short Form Survey (SF-12) and the objectifiable strength measurement using the dynamometer BIODEX®. Pre-existing gait disorders and permanent pain therapy led to exclusion. RESULTS: The mean AOFAS-AH was 87.8 points (FHL: 85.6, SR: 90.6), the mean VAS FA was 78.1 points (FHL: 73.7, SR: 83.6), the mean PCS was 48.2 points (FHL: 46.3, SR: 50.7) and the mean MCS was 54.1 points (FHL: 55.0, SR: 53.0). The maximum torque for plantar flexion was 56.7 Nm on average (FHL: 51.0, SR: 63.7). A total of seven (11.7%) wound infections requiring revision occurred (FHL: 4 (11.8%), SR: 3 (11.5%)). All measurements did not differ significantly between the groups (p > 0.05). CONCLUSION: The results of the study prove the equivalence of FHL and SR based on the clinical scores as well as on the strength measurement using BIODEX®. Nevertheless, a higher withdrawal because of morbidity with a tendency for prolonged incapacity to work in the FHL group has to be taken into account. The present work provides the basis for a prospective comparison in future studies.