Accurate surgical posterior tibial slope alteration can be achieved in total knee arthroplasty regardless of surgeon skill level or local soft tissue thickness-A retrospective radiograph-based study.

PURPOSE: To retrospectively report on the impact of local soft tissue thickness and surgeon skill level on the accuracy of surgical posterior tibial slope (PTS) alteration achieved in patients undergoing total knee arthroplasty (TKA) utilising lateral knee radiographs. METHODS: Pre- and postoperative radiographs of 82 patients undergoing primary TKA using conventional mechanical alignment technique were measured by two observers and subjected to quality criteria for accurate measurement of the PTS. All patients underwent a standardised surgical approach for PTS alteration: cruciate-retaining (CR) cases with preoperative PTS ≤ 10° were set for reconstruction of the preoperative PTS. Cases indicated for posterior-stabilised (PS) design and/or with a preoperative PTS > 10° were set for 3° of postoperative PTS. Pretibial subcutaneous fat (PSF) and surgeon skill level were analysed for their predictive quality regarding the accuracy of surgical PTS alteration achieved. RESULTS: The overall mean postoperative PTS was significantly lower than the preoperative values (6.2°, SD 2.7 vs. 7.7°, SD 3.2; p = 0.002103). Neither local soft tissue thickness, namely PSF, nor surgeon skill level was found to be a predictor of the accuracy of surgical PTS alteration achieved. Among cases set for PTS reconstruction, 25.9% and 42.6% achieved a postoperative PTS within ±1° and ±2° of preoperative values, respectively. In patients with a PTS > 10° or those indicated for PS design, slope reduction was achieved with a mean postoperative PTS of 6.5°. Furthermore, 14.3% and 32.1% of cases were within ±1° and ±2° of 3, respectively. CONCLUSION: This study demonstrates that accurate surgical alteration of the PTS is possible in TKA regardless of local knee soft tissue thickness or surgeon skill level. This proves the clinical feasibility of both targeted reduction as well as reconstruction of the PTS in TKA. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Influence of the type of stem and its fixation on revision and immediate postoperative mortality in elective total hip arthroplasty.

Aims: Despite higher rates of revision after total hip arthroplasty (THA) being reported for uncemented stems in patients aged > 75 years, they are frequently used in this age group. Increased mortality after cemented fixation is often used as a justification, but recent data do not confirm this association. The aim of this study was to investigate the influence of the design of the stem and the type of fixation on the rate of revision and immediate postoperative mortality, focusing on the age and sex of the patients. Methods: A total of 333,144 patients with primary osteoarthritis (OA) of the hip who underwent elective THA between November 2012 and September 2022, using uncemented acetabular components without reconstruction shells, from the German arthroplasty registry were included in the study. The revision rates three years postoperatively for four types of stem (uncemented, uncemented with collar, uncemented short, and cemented) were compared within four age groups: < 60 years (Young), between 61 and 70 years (Mid-I), between 71 and 80 years (Mid-II), and aged > 80 years (Old). A noninferiority analysis was performed on the most frequently used designs of stem. Results: The design of the stem was found to have no significant influence on the rate of revision for either sex in the Young group. Uncemented collared stems had a significantly lower rate of revision compared with the other types of stem for females in the Mid-I group. There was a significantly higher rate of revision for uncemented stems in females in the Mid-II group compared with all other types of stem, while in males the rate for uncemented stems was only significantly higher than the rate for cemented stems. Cemented stems had a significantly lower revision rate compared with uncemented and short stems for both sexes in the Old cohort, as did females with collared stems. The rate of immediate postoperative mortality was similar for all types of stem in the Old age group, as were the American Society of Anesthesiologists grades. Conclusion: In patients aged > 80 years, uncemented and short stems had significantly higher revision rates compared with cemented and collared stems, especially in females. The design of the stem and type of fixation have to be analyzed in more detail than only considering cemented and uncemented fixation, in order to further improve the success of THA.

Bilateral simultaneous knee arthroplasty shows comparable early outcome and complication rate as staged bilateral knee arthroplasty for patients scored ASA 1-3 if performed by a high-volume surgeon: a retrospective cohort study of 127 cases.

BACKGROUND AND PURPOSE: The study compares early outcomes after simultaneous and staged knee arthroplasty in patients with bilateral knee osteoarthritis (OA) to evaluate whether simultaneous bilateral TKA shows comparable early outcomes and complication rates to staged bilateral TKA. METHODS: A retrospective cohort study including all patients scheduled for primary TKA for bilateral knee OA (n = 127) was conducted. Patients received either simultaneous (n = 53, 41.7%) or staged (n = 74, 58.3%) bilateral TKA by a single, high-volume surgeon-depending on their individual preference. Demographic data, haemoglobin drop (Hb), length of stay (LOS), operation time, 30-day complication rate and achievement of rehabilitation key points were evaluated. RESULTS: There was no difference between the groups concerning age, sex, BMI or complication rate. ASA scoring was better in the simultaneous group [2.2, (15.1% ASA 1, 49.1% ASA 2, 35.8% ASA 3) vs. 2.4 (2.7% ASA 1, 51.4% ASA 2, 45.9% ASA 3)]. Average LOS was 7.8 ± 2.1 days for simultaneous TKA, 7.4 ± 1.7 days for single procedure of staged group (p < 0.453) and 14.7 ± 3.1 days if combined (p < 0.001). Cumulative Hb loss was significantly higher in the staged group (3.8 ± 1.2 g/dl vs. 2.4 ± 0.8 g/dl, p < 0.001). Detailed comparison of early outcome parameters between staged and simultaneous procedure depending on ASA score only revealed slightly slower assessment of stairs (p < 0.001) and increased Hb drop per surgery in case of simultaneous procedure (p < 0.011) if ASA score was ≥ 2. Only patients scored ASA 3 demonstrated a significant longer LOS per procedure in simultaneous group (8.5 ± 2.4 vs.7.3 ± 1.6 days, p = 0.034). INTERPRETATION: Simultaneous bilateral TKA results in comparable early outcome and complication rate than staged bilateral procedure-even for patients scored ASA 3. LEVEL OF EVIDENCE: Level IV.

[Acute postoperative infections after dual head arthroplasty in geriatric patients]. / Akute postoperative Infektion nach Duokopfprothesenimplantation beim geriatrischen Patienten.

Acute periprosthetic joint infections (PJI) after dual head arthroplasty represent a major challenge with a 1-year mortality rate up to 50% in the mostly multimorbid geriatric patient collective. Due to the limited possibilities of preoperative patient optimization, infection rates of up to 9% have been reported, which is significantly higher than in elective arthroplasty. A therapeutic gold standard has not yet been established due to the heterogeneous study situation and the lack of prospective randomized studies. The most promising therapeutic option currently appears to be a single-stage stem replacement in combination with implantation of a cup component (conversion to total hip arthroplasty, infection eradication in up to 100%). An approach of débridement, antibiotics, implant retention (DAIR) alone shows significantly poorer success rates (16-82%). Surgical treatment should always be followed by antibiotic treatment with a total duration of 12 weeks. In addition to the established perioperative antibiotic prophylaxis, the use of antibiotic-loaded bone cement seems to be superior to cementless stem fixation in preventing PJI in dual head arthroplasty.

Increased ankle pain after total knee arthroplasty is associated with a preoperative lateralized gait and talar tilt, but not with ankle laxity or the range of motion of the subtalar joint.

Aims: Total knee arthroplasty (TKA) may provoke ankle symptoms. The aim of this study was to validate the impact of the preoperative mechanical tibiofemoral angle (mTFA), the talar tilt (TT) on ankle symptoms after TKA, and assess changes in the range of motion (ROM) of the subtalar joint, foot posture, and ankle laxity. Methods: Patients who underwent TKA from September 2020 to September 2021 were prospectively included. Inclusion criteria were primary end-stage osteoarthritis (Kellgren-Lawrence stage IV) of the knee. Exclusion criteria were missed follow-up visit, post-traumatic pathologies of the foot, and neurological disorders. Radiological angles measured included the mTFA, hindfoot alignment view angle, and TT. The Foot Function Index (FFI) score was assessed. Gait analyses were conducted to measure mediolateral changes of the gait line and ankle laxity was tested using an ankle arthrometer. All parameters were acquired one week pre- and three months postoperatively. Results: A total of 69 patients (varus n = 45; valgus n = 24) underwent TKA and completed the postoperative follow-up visit. Of these, 16 patients (23.2%) reported the onset or progression of ankle symptoms. Varus patients with increased ankle symptoms after TKA had a significantly higher pre- and postoperative TT. Valgus patients with ankle symptoms after TKA showed a pathologically lateralized gait line which could not be corrected through TKA. Patients who reported increased ankle pain neither had a decreased ROM of the subtalar joint nor increased ankle laxity following TKA. The preoperative mTFA did not correlate with the postoperative FFI (r = 0.037; p = 0.759). Conclusion: Approximately one-quarter of the patients developed ankle pain after TKA. If patients complain about ankle symptoms after TKA, standing radiographs of the ankle and a gait analysis could help in detecting a malaligned TT or a pathological gait.

Bilateral simultaneous hip arthroplasty shows comparable early outcome and complication rate as staged bilateral hip arthroplasty for patients scored ASA 1-3 if performed by a high-volume surgeon.

PURPOSE: The aim of this study was to compare early outcomes after simultaneous and staged hip arthroplasty (THA) in patients with bilateral symptomatic pathology. METHODS: We conducted a retrospective cohort study including all patients scheduled for primary THA for bilateral hip osteoarthritis (OA, n = 290). Patients either received simultaneous (n = 152, 52.4%) or staged (n = 138, 47.6%) bilateral THA based on individual preference. All operations (n = 428) were performed by one single, high-volume surgeon. Demographic data (e.g., age, ASA score) as well as perioperative parameters (haemoglobin drop (Hb), red blood cell transfusion, length of stay (LOS), operation time, six week complication rate and achievement of inpatient rehabilitation key points) were evaluated. RESULTS: Patients in the simultaneous bilateral THA group were younger (62.8 ± 8.9 vs. 65 ± 9.7 years, p = 0.022) and had lower ASA scores (1.8, (34.2% ASA 1, 55.3% ASA 2, 37.2% ASA 3) vs. 2.0 (18.8% ASA 1, 61.6% ASA 2, 19.6% ASA 3)) than the staged group. While the average LOS was 7.1 ± 1.7 days for simultaneous bilateral THA, the combined LOS for the staged group was 12.9 ± 2.4 days (p < 0.001). The cumulative operation time in the simultaneous bilateral THA group was 61.1 ± 11.5 min and 57.6 ± 7.3 min in the staged group (p < 0.015). Cumulative Hb loss was significantly higher in the staged group (2.1 ± 7.2 g/dl vs. 3.7 ± 1.3 g/dl, p < 0.001). No significant differences were found concerning the complication rate or early inpatient rehabilitation. CONCLUSION: Simultaneous bilateral hip arthroplasty in patients with symptomatic bilateral hip osteoarthritis is as safe and successful as a staged procedure if performed by a high-volume surgeon.

Functional gait analysis reveals insufficient hindfoot compensation for varus and valgus osteoarthritis of the knee.

PURPOSE: The hindfoot is believed to compensate varus and valgus deformities of the knee by eversion and inversion movements. But these mechanisms were merely found in static radiologic measurements. The aim of this study was, therefore, to assess dynamic foot posture during gait using pressure-sensitive wireless insoles in patients with osteoarthritis of the knee and frontal knee deformities. METHODS: Patients with osteoarthritis of the knee were prospectively included in this study. Patients were clinically and radiologically (mechanical tibiofemoral angle (mTFA), hindfoot alignment view angle (HAVA), and talar tilt (TT)) exa mined. Gait line analysis was conducted using pressure-sensitive digital shoe insoles. RESULTS: Eighty-two patients (varus n = 52, valgus n = 30) were included in this prospective clinical study. Radiologically, the mTFA significantly correlated with the HAVA (cor = -0.72, p < 0.001) and with the TT (Pearson's cor = 0.32, p < 0.006). Gait analysis revealed that the gait lines in varus knee osteoarthritis were lateralized, despite the hindfoot valgus. In valgus knee osteoarthritis, gait lines were medialized, although the hindfoot compensated by varization. CONCLUSIONS: Functional dynamic gait analysis could demonstrate that the hindfoot is not able to sufficiently compensate for frontal malalignments of the knee joint, contrary to static radiologic findings. This led to a narrowing of the joint space of the ankle medially in varus and laterally in valgus knee osteoarthritis.

Major Shortening of the Patellar Tendon During Septic Two-Stage Knee Arthroplasty Revision Using Static Spacers.

BACKGROUND: Two-stage septic revision knee arthroplasty (TKA) often results in inferior functional outcome after reimplantation, which might be due to impairments of the extensor mechanism. The aim of the current study was to elucidate possible alterations in extensor mechanisms during septic two-stage revision of TKA treated with a static spacer. METHODS: This retrospective study included 87 patients (42 women, 45 men, age 64.5 ± 10.5; range, 29-85 years) undergoing septic two-stage TKA revision using a static spacer. The modified Insall Salvati ratio (mISR) was calculated via calibrated true lateral radiographs by two independent orthopedic surgeons before TKA explantation (G0), 6-8 days after TKA removal (G1), one day before TKA reimplantation (G2) and 6-8 days after TKA reimplantation (G3). Age, sex, body mass index (BMI), index C-reactive protein level, and number of previous surgeries were evaluated to identify the possible correlations. RESULTS: Overall, mISR significantly decreased within the first 6 days after index surgery from 1.71 ± 0.41 to 1.63 ± 0.41 (G0 versus G1, P < .001) and showed a further decline within the next 6 weeks to 1.54 ± 0.39 (G1 versus G2, P = .002). Conversely, mISR increased after reimplantation of TKA to 1.6 ± 0.43 (G3 versus G2, P = .08), though it did not regain preoperative baseline levels (G0 versus G3, P < .001). The subgroup with mISR decrease ≥10% experienced patellar tendon shortening of 16% between G0 and G1, 19% between G0 and G2 and up to 20% between G0 and G3. There were weak correlations concerning age (r = -0.240, P = .038), preoperative C-reactive protein level (r = 0.239, P = .04) and patellar tendon shortening. Intraclass correlation coefficient (ICC)was 0.88 concerning radiographic measurement. CONCLUSION: Septic two-stage TKA revision using static spacers leads to irreversible alterations of the extensor mechanism, specifically a major shortening of the patellar tendon, in one out of 3 patients. LEVEL OF EVIDENCE: II.

Clinical evaluation of dithiothreitol in comparison with sonication for biofilm dislodgement in the microbiological diagnosis of periprosthetic joint infection.

Sonication of explanted devices is well investigated method and was shown to improve the microbiological diagnosis of impant-associated infections by physical removal of bacterial biofilms. Recently, novel approach with chemical agents have been investigated for biofilm dislodgement such as dithiothreitol (DTT). We compared the biofilm dislodgement efficacy of chemical method (dithiothreitol, DTT) compared to the sonication procedure in the diagnosis of prosthetic joint infections (PJI). In a prospective cohort, 187 patients undergoing hip and knee prostheses explantation were included, of whom 94 were assigned for sonication and 93 for DTT group. Sonication showed better sensitivity (73.8%) than DTT (43.2%) for the diagnosis of PJI and comparable specificity (98% and 94.6%, respectively). We concluded that sonication provides a more reliable diagnosis of PJI and detects about 30% more pathogens compared to DTT system. The study was registered at ClinicalTrials.gov (NCT02530229).

Failure Analysis in Multiple TKA Revisions-Periprosthetic Infections Remain Surgeons' Nemesis.

BACKGROUND: The aim of this study was to categorize reasons for failure and to analyze the survivorship of multiple total knee arthroplasty (TKA) revisions. METHODS: The study retrospectively evaluated all multiple TKA revisions performed between 2005 and 2015 at the authors' institutions. Sixty-three patients (35 female, 28 male, age 64 ± 10 years, follow-up 55 ± 36 months) underwent a total of 157 re-revision TKA surgeries (range 2-5). The revision indications were divided up into main diagnoses. Survivorship was evaluated by mixed model analysis. RESULTS: The main overall reason for re-revision was periprosthetic joint infection (PJI) (48%), followed by instability (12%), polyethylene wear (11%), malpositioning (8%), and aseptic loosening (8%). Survivorship shortened with an increasing number of revision surgeries (p = 0.003). While PJI was in 38% of all cases, the reason for the first revision, incidence increased constantly with the number of revisions (48% at second revision, 55% at third revision, 86% at fourth revision, and 100% at fifth revision, p = 0.022). If periprosthetic infection caused the first revision, patients showed an average of two more septic revisions at follow-up than patients with an aseptic first revision indication (p < 0.001). In 36% of cases, the reason for follow-up surgery in case of periprosthetic infection was again PJI. CONCLUSION: The probability of survival of the implanted knee arthroplasty is significantly reduced with each subsequent revision. Periprosthetic infection is the main cause of multiple revisions.

Significant increase in quantity and quality of knee arthroplasty related research in KSSTA over the past 15 years.

PURPOSE: This study aimed to evaluate both publication and authorship characteristics in Knee Surgery, Sports Traumatology, Arthroscopy journal (KSSTA) regarding knee arthroplasty over the past 15 years. METHODS: PubMed was searched for articles published in KSSTA between January 1, 2006, and December 31st, 2020, utilising the search term 'knee arthroplasty'. 1288 articles met the inclusion criteria. The articles were evaluated using the following criteria: type of article, type of study, main topic and special topic, use of patient-reported outcome scores, number of references and citations, level of evidence (LOE), number of authors, gender of the first author and continent of origin. Three time intervals were compared: 2006-2010, 2011-2015 and 2016-2020. RESULTS: Between 2016 and 2020, publications peaked at 670 articles (52%) compared with 465 (36%) published between 2011 and 2016 and 153 articles (12%) between 2006 and 2010. While percentage of reviews (2006-2010: 0% vs. 2011-2015: 5% vs. 2016-2020: 5%) and meta-analyses (1% vs. 6% vs. 5%) increased, fewer case reports were published (13% vs. 3% vs. 1%) (p < 0.001). Interest in navigation and computer-assisted surgery decreased, whereas interest in perioperative management, robotic and individualized surgery increased over time (p < 0.001). There was an increasing number of references [26 (2-73) vs. 30 (2-158) vs. 31 (1-143), p < 0.001] while number of citations decreased [30 (0-188) vs. 22 (0-264) vs. 6 (0-106), p < 0.001]. LOE showed no significant changes (p = 0.439). The number of authors increased between each time interval (p < 0.001), while the percentage of female authors was comparable between first and last interval (p = 0.252). Europe published significantly fewer articles over time (56% vs. 47% vs. 52%), whereas the number of articles from Asia increased (35% vs. 45% vs. 37%, p = 0.005). CONCLUSION: Increasing interest in the field of knee arthroplasty-related surgery arose within the last 15 years in KSSTA. The investigated topics showed a significant trend towards the latest techniques at each time interval. With rising number of authors, the part of female first authors also increased-but not significantly. Furthermore, publishing characteristics showed an increasing number of publications from Asia and a slightly decreasing number in Europe. LEVEL OF EVIDENCE: IV.

Effect of total hip arthroplasty on brake reaction time and braking force.

INTRODUCTION: The correct moment for return to driving after total hip arthroplasty (THA) remains unclear. Until today no uniform recommendation exists on the ability to perform an emergency brake.The aim of this prospective study was to investigate the braking ability of patients before and after THA implantation based on brake reaction time in milliseconds (BRT) and braking force in N (BF). METHODS: In total, 25 patients (15 men, 10 women, mean age 51.3 ± 10.1 years) were treated with THA on the right side. Inclusion criteria consisted of a valid driving licence, frequent road participation and at least 2 years of driving experience. Exclusion criteria were underlying neurological disorders as well as severe complaints in the lumbar spine and the right knee joint. The brake ability was evaluated for emergency braking with a car simulator and a measuring sole. Measurements were performed preoperatively, 6 days, 2, 4 and 6 weeks after surgery. RESULTS: Preoperatively, the mean BRT was 671.3 ± 123.5 ms and the BF 455.4 ± 185.0 N. Significant differences were observed at 6 days and 2 weeks after surgery, (BRT 836.4 ± 219.7 ms, respectively, BRT 735.0 ± 186.7 ms, and BF 302.6 ± 154.9 N, respectively, BF 375.5 ± 149.3 N, p < 0.05). Only 4 weeks after, no significant differences were seen compared to pre-operative with a BRT of 647.0 ± 91.9ms (p = 0.354) and BF of 435.9 ± 177.4 (p = 0.843). Furthermore, the BRT improved significantly after 6 weeks (607.4 ± 87.6; p = 0.005). CONCLUSIONS: The braking force is significantly reduced, and the brake reaction time is prolonged directly after surgery for at least 2 weeks. After 4 weeks, no statistically significant differences were measured, although special care should still be taken during return to activity.

[Septic revision arthroplasty: how to confirm diagnosis, plan surgery and manage follow-up treatment]. / Septische Revisionsprothetik: Vorbereitung, Durchführung und Nachbehandlung.

BACKGROUND: Septic revision arthroplasty represents an interdisciplinary challenge in terms of diagnosis as well as surgical and follow-up treatment. DIAGNOSIS: The implementation of a standardized diagnostic algorithm including anamnesis, clinic, imaging, blood sampling and joint aspiration is essential. Depending on the duration of the symptoms acute (< 3 weeks) and chronic (> 3 weeks) infections are distinguished. THERAPY: While acute infections show an immature biofilm and can usually be addressed surgically via debridement and changing the mobile parts, chronic infections almost always require a complete change of the implant. This can be done in one or two stages, depending on the general condition of the patient, the pathogen, its resistances as well as the wound conditions. The surgical revision is always followed by a resistance-based antibiotic treatment.

Public Interest in Knee Pain and Knee Replacement during the SARS-CoV-2 Pandemic in Western Europe.

Due to the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) pandemic, a large number of elective knee replacement procedures had to be postponed in both early and late 2020 in most western countries including Germany and the UK. It is unknown how public interest and demand for total knee arthroplasties was affected. Public interest in knee pain, knee osteoarthritis and knee arthroplasty in Germany and the UK was investigated using Google Trend Analysis. In addition, we monitored for changes in patient composition in our outpatient department. As of early March in Germany and of late March in the UK, until the lockdown measures, a 50 to 60% decrease in relative search frequency was observed in all categories investigated compared to the beginning of the year. While public interest for knee pain rapidly recovered, decreased interest for knee osteoarthritis and replacement lasted until the easing of measures. Shortly prior to and during the first lockdown mean search frequency for knee replacement was significantly decreased from 39.7% and 36.6 to 26.9% in Germany and from 47.7% and 50.9 to 23.7% in the UK (Germany: p = 0.022 prior to lockdown, p < 0.001 during lockdown; UK: p < 0.0001 prior to and during lockdown). In contrast, mean search frequencies did not differ significantly from each other for any of the investigated time frames during the second half of 2020 in both countries. Similarly, during the first lockdown, the proportion of patients presenting themselves to receive primary knee arthroplasty compared to patients that had already undergone knee replacement declined markedly from 64.7% to 46.9%. In contrast, patient composition changed only marginally during the lockdown measures in late 2020 in both Germany and the UK. We observed a high level of public interest in knee arthroplasty despite the ongoing pandemic. The absence of a lasting decline in interest in primary knee arthroplasty suggests that sufficient symptom reduction cannot be achieved without surgical care for a substantial number of patients.

Soluble Pecam-1 as a Biomarker in Periprosthetic Joint Infection.

A reliable workup with regard to a single diagnostic marker indicating periprosthetic joint infection (PJI) with sufficient sensitivity and specificity is still missing. The immunologically reactive molecule Pecam-1 is shed from the T-cell surface upon activation via proinflammatory signaling, e.g., triggered by specific pathogens. We hypothesized that soluble Pecam-1 (sPecam-1) can hence function as a biomarker of PJI. Fifty-eight patients were prospectively enrolled and assigned to one of the respective treatment groups (native knees prior to surgery, aseptic, and septic total knee arthroplasty (TKA) revision surgeries). Via synovial sample acquisition and ELISA testing, a database on local sPecam-1 levels was established. We observed a significantly larger quantity of sPecam-1 in septic (n = 22) compared to aseptic TKA revision surgeries (n = 20, p ≤ 0.001). Furthermore, a significantly larger amount of sPecam-1 was found in septic and aseptic revisions compared to native joints (n = 16, p ≤ 0.001). Benchmarking it to the gold standard showed a high predictive power for the detection of PJI. Local sPecam-1 levels correlated to the infection status of the implant, and thus bear a strong potential to act as a biomarker of PJI. While a clear role of sPecam-1 in infection could be demonstrated, the underlying mechanism of the molecule's natural function needs to be further unraveled.

Does sonography allow an objective and reproducible distinction between stable, hypermobile, and unstable elbow joints?

BACKGROUND: The diagnosis of residual or chronic elbow instability is often challenging. Sonography allows a dynamic examination of the elbow joint without any radiation exposure. The purpose of this prospective single-center study was to investigate the application of sonography for the evaluation of ligamentous instabilities of the elbow joint. Therefore, asymptomatic (stable) and acute dislocated (unstable) elbows were examined by sonography. METHODS: A total of 72 elbows in 36 participants (23 women and 13 men; mean age, 40 ± 17 years [range, 18-82 years]) were examined. Group 1 (G1 [normal]) included 40 unaffected, asymptomatic elbow joints; 28 elbows belonged to 14 voluntary participants (bilateral), whereas 12 asymptomatic elbows belonged to patients who had an acute elbow dislocation (contralateral elbow). Group 2 (G2 [hypermobile]) included 20 hypermobile elbow joints in 10 participants (bilateral), and group 3 (G3 [unstable]) included 12 acute unstable elbow joints without bony lesions. Radiographic assessment included sonography of both elbow joints with standardized measurements of the neutral and stressed radiocapitellar and ulnohumeral distances (calculated as Δ values). Two investigators independently performed all measurements. Additionally, plain radiographs and magnetic resonance imaging of the affected elbow joints were obtained in G3. RESULTS: On the radial side, the mean radiocapitellar Δ was statistically higher in G3 (2.2 ± 1.6 mm) than in G1 (0.5 ± 0.4 mm, P < .01) or G2 (0.8 ± 0.6 mm, P < .01). G3 also showed an increased ulnohumeral Δ (2.7 ± 0.7 mm) compared with G1 (1.0 ± 0.7 mm, P < .01) or G2 (0.9 ± 0.3 mm, P < .01). No significant differences in the mean radiocapitellar Δ (P = .06) and ulnohumeral Δ (P = .26) were found between G1 and G2. Within G3, Δ was significantly higher at the affected elbow joint than at the contralateral, unaffected elbow joint (P = .04 for the radial side and P = .04 for the ulnar side). The inter-rater correlation coefficient was 0.82 for the radial side and 0.74 for the ulnar side. Patients with collateral ligament injuries, diagnosed on magnetic resonance imaging, showed higher Δ values than those with intact collateral ligaments, although no significant difference was found. CONCLUSION: Sonography of the elbow joint is a valuable imaging tool for the assessment of ligamentous instability. Nevertheless, a distinction between healthy and hypermobile elbow joints is not possible, and therefore, obtaining a complete clinical history and examination is vital. We further recommend comparing the affected elbow joint with the contralateral side to access intraindividual differences.

Laminar air flow reduces particle load in TKA-even outside the LAF panel: a prospective, randomized cohort study.

PURPOSE: Released particles are a major risk of airborne contamination during surgery. The present prospective study investigated the quantitative and qualitative particle load in the operating room (OR) depending on location, time of surgery and use of laminar air flow (LAF) system. METHODS: The particle load/m3 was measured during the implantation of 12 total knee arthroplasties (6 × LAF, 6 × Non-LAF) by using the Met One HHPC 6 + device (Beckmann Coulter GmbH, Germany). Measurement was based on the absorption and scattering of (laser) light by particles and was performed at three different time-points [empty OR, setting up, ongoing operation) at 3 fixed measurement points [OR table (central LAF area), anaesthesia tower (marginal LAF area), surgical image amplifier (outside LAF area)]. RESULTS: Independent of time and location, all measurements showed a significantly higher particle load in the Non-LAF group (p < 0.01). With ongoing surgical procedure both groups showed increasing particle load. While there was a major increase of fine particles (size < 1 µm) with advancing activity in the LAF group, the Non-LAF group showed higher particle gain with increasing particle size. The lowest particle load in the LAF group was measured at the operating column, increasing with greater distance from the operating table. The Non-LAF group presented a significantly higher particle load than the LAF group at all locations. CONCLUSION: The use of a LAF system significantly reduces the particle load and therefore potential bacterial contamination regardless of the time or place of measurement and therefore seems to be a useful tool for infection prevention. As LAF leads to a significant decrease of respirable particles, it appears to be a protective factor for the health of the surgical team regardless of its use in infection prevention. LEVEL OF EVIDENCE: I.

Reaction time and brake pedal force after total knee replacement: timeframe for return to car driving.

PURPOSE: This prospective cohort study aimed to examine objective and subjective parameters in patients who underwent total knee replacement (TKR) to assess from when on driving a car can be deemed safe again. METHODS: Thirty patients (16 women, 14 men, age 66 ± 11 years) who received TKR of the right knee and 45 healthy controls (26 women, 19 men, age 32 ± 9 years) were asked to perform an emergency braking manoeuvre using a driving simulator. Brake pedal force (BPF), neuronal reaction time (NRT), brake reaction time (BRT), and subjective parameters (pain, subjective driving ability) were measured preoperatively as well as 5 days, 3-4, and 6 weeks after TKR. RESULTS: Preoperative NRT was 506 ± 162 ms, BRT 985 ± 356 ms, and BPF 614 ± 292 N. NRT increased to 561 ± 218 ms, BRT to 1091 ± 404 ms and BPF decreased to 411 ± 191 N 5 days after TKR. Three weeks after surgery, NRT was 581 ± 164 ms and BRT 1013 ± 260 ms, while BPF increased to 555 ± 200 N. Only BPF showed significant differences (p < 0.01). In week 6, all parameters were restored to baseline levels; patients showed significant pain decrease and evaluated their driving ability as "good" again. CONCLUSION: BPF was the only parameter displaying a significant postoperative decrease. However, preoperative patients' baseline levels and subjective confidence in driving ability were only reached 6 weeks after the operation. These results indicate that a minimum waiting period of 6 weeks should be considered before patients can safely participate in road traffic at their individual preoperative safety level again. LEVEL OF EVIDENCE: II.

Local infiltration anaesthesia versus sciatic nerve and adductor canal block for fast-track knee arthroplasty: A randomised controlled clinical trial.

BACKGROUND: Local infiltration anaesthesia (LIA) was introduced as an innovative analgesic procedure for enhanced recovery after primary total knee arthroplasty (TKA). However, LIA has never been compared with analgesia based on an adductor canal catheter and a single-shot sciatic nerve block. OBJECTIVE: To evaluate two analgesic regimens for TKA comparing mobility, postoperative pain and patient satisfaction. DESIGN: Two-group randomised, controlled clinical trial. SETTING: Charité-Universitätsmedizin Berlin, Campus Charité Mitte, Germany between April and August 2017. PATIENTS: Adults undergoing primary TKA under general anaesthesia were eligible for study participation. Exclusion criteria were heart insufficiency (New York Heart Association class >2), liver insufficiency (Child Pugh Score >B), evidence of diabetic polyneuropathy, severe obesity (BMI > 40 kg m), chronic opioid therapy for more than 3 months before scheduled surgery and allergy to local anaesthetics. INTERVENTIONS: Nerve block patients group (n=20) underwent surgery with two ultrasound-guided regional anaesthesia blocks: a single-shot sciatic nerve block with 20 ml of ropivacaine 0.75% combined with an adductor canal block with a catheter placed for less than 4 days with an infusion of ropivacaine 0.2% at a rate of 6 ml h. LIA patients (LIA group, n=20) received LIA of the knee capsule at the end of surgery with 150 ml of ropivacaine 0.2%. MAIN OUTCOME MEASURES: The primary endpoint was postoperative time to patient mobilisation (ability to walk) on the ward. RESULTS: Baseline characteristics were similar in each study group. Patients in both groups were mobilised to walk after TKA in similar time frames (LIA 24.0 h versus nerve block 27.1 h, 95% CI of difference -9.6 to 3.3 h). Maximum postoperative pain scores on exertion were higher in LIA patients with a mean 1.3 of 10 numerical rating scale points (95% CI 0.3 to 2.3, P = 0.010) as were intra-operative opioid requirements (LIA median 107 [IQR 100 to 268] mg versus nerve block median 78 [60 to 98] mg, P < 0.001). Patient satisfaction, postoperative oral morphine-equivalents and resting pain levels were comparable between groups. Anaesthesia induction time was reduced in LIA patients (LIA 10 min versus nerve block 35 min, 95% CI of difference 13 to 38 min, P < 0.001). CONCLUSION: Both analgesic regimens allow early mobilisation after TKA with high patient satisfaction. LIA shortened peri-operative time. Further research is required to optimise especially pain control during the later postoperative period with LIA. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov identifier NCT03114306.