Demographic characteristics influencing the stem subsidence in total hip arthroplasty: an imaging study.

INTRODUCTION: The present study evaluated whether patient demographic characteristics influence the subsidence of the stem in total hip arthroplasty (THA). The following characteristics were evaluated: age, height, weight, and sex. The association between the time elapsed from the THA implantation and the amount of stem subsidence was also investigated. METHODS: The records of patients who underwent THA in the period between 2016 and 2023 were accessed. All patients underwent two-staged bilateral THA using cementless DePuy collarless Corail (DePuy Synthes, Raynham, MA, USA) stems. The following parameters were measured and compared to assess stem subsidence: distance from the proximal femur at the stem bone interface and the medial apex of the regular triangle built within the trochanter minor (point A); distance from the medial apex of the regular triangle built within the trochanter minor and the distal portion of the femoral stem (point B). RESULTS: Overall, 294 patients were included. 62% (182 of 294 patients) were women. 45% (134 of 296 THAs) were on the right side. The mean age was 64.9 ± 10.4 years. The mean BMI was 28.3 ± 5.1 kg/m2. The mean length of the follow-up was 14.4 ± 11.0 months. The mean subsidence in point A was 2.1 mm (P < 0.0001), and that in point B was 3.1 mm (P < 0.0001). There was evidence of a weak positive association between patient weight (P < 0.0001), age (P = 0.03), follow-up (P = 0.002) and the amount of stem subsidence. Patient height did not demonstrate any association with the amount of stem subsidence (P = 0.07). There was no difference in stem subsidence between women and men (P = 0.9). CONCLUSION: Stem subsidence in THA using cementless DePuy collarless Corail implants is approximately 2.6 mm after 14.4 months. Greater patient weight, age, and longer time elapsed from THA implantation were associated with greater stem subsidence. Patient height and sex did not demonstrate any influence on the amount of stem subsidence. These results must be considered in light of the limitations of the present study.

Antithrombotic prophylaxis following total hip arthroplasty: a level I Bayesian network meta-analysis.

BACKGROUND: Several clinical investigations have compared different pharmacologic agents for the prophylaxis of venous thromboembolism (VTE). However, no consensus has been reached. The present investigation compared enoxaparin, fondaparinux, aspirin and non-vitamin K antagonist oral anticoagulants (NOACs) commonly used as prophylaxis following total hip arthroplasty (THA). A Bayesian network meta-analysis was performed, setting as outcomes of interest the rate of deep venous thrombosis (DVT), pulmonary embolism (PE) and major and minor haemorrhages. METHODS: This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension statement for reporting systematic reviews incorporating network meta-analyses of healthcare interventions. All randomised controlled trials (RCTs) comparing two or more drugs used for the prophylaxis of VTE following THA were accessed. PubMed, Web of Science and Google Scholar databases were accessed in March 2023 with no time constraint. RESULTS: Data from 31,705 patients were extracted. Of these, 62% (19,824) were women, with age, sex ratio, and body mass index (BMI) being comparable at baseline. Apixaban 5 mg, fondaparinux, and rivaroxaban 60 mg were the most effective in reducing the rate of DVT. Dabigatran 220 mg, apixaban 5 mg, and aspirin 100 mg were the most effective in reducing the rate of PE. Apixaban 5 mg, ximelagatran 2 mg and aspirin 100 mg were associated with the lowest rate of major haemorrhages, while rivaroxaban 2.5 mg, apixaban 5 mg and enoxaparin 40 mg were associated with the lowest rate of minor haemorrhages. CONCLUSION: Administration of apixaban 5 mg demonstrated the best balance between VTE prevention and haemorrhage control following THA. Level of evidence Level I, network meta-analysis of RCTs.

Telemedicine in orthopaedics and trauma surgery during the first year of COVID pandemic: a systematic review.

PURPOSE: Prior to the COVID-19 pandemic, telemedicine in orthopaedics and trauma surgery had mostly developed for joint arthroplasty, fracture management, and general pre- and postoperative care including teleradiology. With the corona-outbreak, telemedicine was applied on a broad scale to prevent assemblage and to guarantee access to medical care protecting critical areas. The purpose of the present study was to give an overview of the spectrum of clinical applications and the efficacy of telemedicine in orthopaedic and trauma surgery as published in times of the COVID-19 pandemic. METHODS: All published studies investigating the application of telemedicine related to orthopaedics and trauma during the COVID-19 pandemic were accessed and screened for suitability. The primary outcome of interest was the efficacy of telemedicine in various clinical applications. The secondary outcome of interest was the spectrum of different applications in which telemedicine applications were investigated. RESULTS: The literature search resulted in 1047 articles. After the removal of duplicates, 894 articles were screened of which 31 finally met the inclusion criteria. Dimensions that were described by studies in the literature to have positive effects were preoperative patient optimisation, the usefulness of telemedicine to correctly diagnose a condition, conservative treatment, willingness to and feasibility for telemedicine in patients and doctors, and postoperative/post-trauma care improvement. The efficacy of telemedicine applications or interventions thereby strongly varied and seemed to depend on the exact study design and the research question addressed. CONCLUSION: Various successful applications of telemedicine have already been reported in orthopaedics and trauma surgery, with a strong increase in scientific output during the COVID-19 years 2020-2021. Whether the advantages of such an approach will lead to a relevant implementation of telemedicine in everyday clinical practice should be monitored after the COVID-19 pandemic.

Changes in femoral rollback and rotation with increasing coupling in knee arthroplasty-a biomechanical in-vitro study.

BACKGROUND: After total knee arthroplasty, 10-30% of patients still complain about knee pain, even after exact positioning of the components. Altered knee kinematics are crucial in this regard. The aim of our study was to experimentally determine the influence of different degrees of component coupling of knee prostheses on joint kinematics during muscle-loaded knee flexion in-vitro. METHODS: Femoral rollback and femoral rotation of a standard cruciate retaining (GCR), a posterior stabilized (GPS), a rotational hinge (RSL) and a total hinge (SSL) design of the same series of knee replacement implants (SL-series) of one single manufacturer (Waldemar Link GmbH, Hamburg, Germany) were analyzed and set in relation to the motion of the corresponding native knee in a paired study design. All different coupling degrees were analyzed in the same human knees. To simulate muscle loaded knee flexion, a knee simulator was used. Kinematics were measured with an ultrasonic motion capture system and integrated in a calculated coordinate system via CT-imaging. RESULTS: The largest posterior motion on the lateral side was found for the native knee (8.7 ± 7.0 mm), followed by the GPS (3.2 ± 5.1 mm) and GCR (2.8 ± 7.3 mm) implants, while no motion was found for the RSL (0.1 ± 3.0 mm) and the SSL (-0.6 ± 2.7 mm) implants. In contrast, on the medial side, only the native knee showed a posterior motion (2.1 ± 3.2 mm). Regarding femoral external rotation, the only implant where the observed difference did not reach statistical significance when compared to the native knee was the GCR (p = 0.007). CONCLUSION: The GCR and GPS kinematics closely imitate those of the native joint. Medial femoral rollback is reduced, however, with the joint pivoting around a rotational center located in the medial plateau. Without additional rotational forces, the coupled RSL and SSL prostheses closely resemble each other with no femoral rollback or relevant rotational component. The femoral axis, however, shifts ventrally in both models when compared with their primary counterparts. The positioning of the coupling mechanism in the femoral and tibial component thus can already lead to altered joint kinematics even in prostheses with an identical surface geometry.

Autologous chondrocyte implantation in the knee is effective in skeletally immature patients: a systematic review.

PURPOSE: This systematic review evaluated the efficacy and safety of autologous chondrocyte implantation (ACI) for chondral defects of the knee in skeletally immature patients. Current available data from patients reported outcome measures (PROMs) and complications were collected, analyzed, and discussed. METHODS: This systematic review was conducted according to the PRISMA guidelines. The following databases were accessed in May 2022: PubMed, Google scholar, Embase, and Scopus. All the clinical studies investigating the efficacy of ACI to manage chondral defects of the knee in skeletally immature patients were accessed. Articles treating patients with surgical procedures other than ACI were not eligible, nor were studies with a follow-up shorter than 12 months. RESULTS: Data from 9 studies (251 procedures) were collected. 32% (80 of 251) of patients were females. The mean length of follow-up was 44.2 ± 29.4 (range, 12-115) months. The mean age of the patients was 16.4 ± 0.7 (range, 15-17) years. The Knee injury and Osteoarthritis Outcome Score (KOOS) and International Knee Document Committee (IKDC) increased of + 41.9/100 (P = 0.003) and + 33.2/100 (P = < 0.0001) points, respectively. The Lysholm Knee Score improved of + 20.6/100 (P = 0.02) points. The Visual Analogue Scale (VAS) for pain reduced of - 3.6/10 (P = 0.004) points. The Tegner scale did not show any statistically significant improvement from baseline to follow-up (P = n.s.). The rate of graft hypertrophy was 12.5% (5 of 40 patients), and the rate of failure 5.6% (8 of 142 patients). CONCLUSION: ACI for chondral defects of the knee is effective to improve PROMs in skeletally immature patients. The safety profile of ACI still remains controversial. LEVEL OF EVIDENCE: III.

Clinical evaluation of a new technique for custom-made spacers in septic two-stage revision of total hip arthroplasties.

INTRODUCTION: In septic two-stage revision surgery, success depends on numerous factors. Key steps are the procedure of ex- and reimplantation and the choice of spacer in the interim phase. The latter is still a matter of debate. Recently, we showed the microbial non-inferiority of a spacer technique using prosthetic cemented implants with an individualized antibiotic mixture in the cement applying a mechanically inferior cementation method. The aim of the present study was to evaluate the clinical results of these spacers in view of either an endofemoral or a transfemoral procedure. MATERIALS AND METHODS: Our collective consisted of 86 patients (45 endofemoral and 41 transfemoral procedures). The collective was analyzed with respect to complications, reinfection rate and clinical status at the end of the interim phase. Results of an endofemoral and transfemoral approach were compared. RESULTS: With a median Staffelstein-Score of 60 (range 31-81) at the end of the interim phase, the first clinical results are promising. The reinfection-free rate after a median follow-up of 50 months was 90%. Spacer-related complications occurred in 8% of the total collective. Comparing the endo- and transfemoral procedure, there were no statistical differences in complications or regarding the clinical and infectiological outcome. CONCLUSIONS: In this study, we were able to show good clinical results for the presented spacer technique. With no relevant difference in outcome, the decision for an endofemoral or transfemoral technique can be based on technical deliberations. Further prospective comparative studies are necessary to show the clinical benefit of this procedure.

Influence of hyaluronic acid on intra-articular friction - a biomechanical study in whole animal joints.

BACKGROUND: Cartilage is a mechanically highly stressed tissue in the human body and an important part of synovial joints. The joint cartilage is lubricated by synovial fluid with hyaluronic acid (HA) as main component. However, in joints with osteoarthritis HA has a lower concentration and molecular weight compared to healthy joints. In recent years, the intra-articular injection of therapeutic HA lubricant, has become a popular therapy. The effect of HA application on the friction of a complete joint with physiological movement needs to be further determined. METHODS: The aim of the present study was to evaluate the lubrication effect of the joint by three lubricants (NaCl, fetal calf serum (FCS) and HA) and their effect on the friction in nine complete ovine carpo-metacarpal joints. The joints were mounted on a material testing machine and a physiological movement with 10° rotation was simulated with ascending axial load (100 - 400 N). Specimens were tested native, with cartilage damage caused by drying out and relubricated. Dissipated energy (DE) as a measure of friction was recorded and compared. RESULTS: Investigating the effect of axial load, we found significant differences in DE between all axial load steps (p < .001), however, only for the defect cartilage. Furthermore, we could document an increase in DE from native (Mean: 15.0 mJ/cycle, SD: 8.98) to cartilage damage (M: 74.4 mJ/cycle, SD: 79.02) and a decrease after relubrication to 23.6 mJ/cycle (SD: 18.47). Finally, we compared the DE values for NaCl, FCS and HA. The highest values were detected for NaCl (MNorm = 16.4 mJ/cycle, SD: 19.14). HA achieved the lowest value (MNorm = 4.3 mJ/cycle, SD: 4.31), although the gap to FCS (MNorm = 5.1 mJ/cycle, SD: 7.07) was small. CONCLUSIONS: We were able to elucidate three effects in joints with cartilage damage. First, the friction in damaged joints increases significantly compared to native joints. Second, especially in damaged joints, the friction increases significantly more with increased axial load compared to native or relubricated joints. Third, lubricants can achieve an enormous decrease in friction. Comparing different lubricants, our results indicate the highest decrease in friction for HA.

The significance of synovial biopsy in the diagnostic workup of the low-grade periprosthetic joint infection of shoulder arthroplasty.

INTRODUCTION: A common reason for painful shoulder arthroplasties and revision surgery is a low-grade periprosthetic joint infection (PJI). Diagnosing a low-grade infection is, however, a major diagnostic challenge. This applies even more to the shoulder, which differs from other large joints in terms of clinical features and microbiological spectrum. Aim of this study was to evaluate the diagnostic value of the synovial biopsy in the diagnostic workup of low-grade PJI of the shoulder. MATERIALS AND METHODS: A retrospective evaluation was conducted on 56 patients receiving revision surgery on their shoulder arthroplasty. A standardized preoperative workup was performed comprising CRP value, leukocyte blood count, synovial fluid microbiological analyses and leukocyte count from joint aspiration, and five synovial biopsy samples for bacteriologic and histologic analysis obtained through an arthroscopic approach. During revision surgery, five samples of periprosthetic tissue were harvested for bacteriologic and histologic analyses. The MSIS-Criteria 2014 were used to evaluate the diagnostic results. RESULTS: In total, 15 of 56 revised prostheses turned out as PJI (27%). When applying our diagnostic workup, we obtained a sensitivity of 67% with a specificity of 95%. When performing a subgroup analysis on those patients that had received diagnostic biopsy, a sensitivity of 100% and a specificity of 83% could be achieved. With a sensitivity and specificity of 90% and 83%, respectively, the biopsy is the single method with the highest diagnostic value. CONCLUSIONS: The sensitivity of only 67% of our standard workup emphasizes the difficulty to adequately diagnose low-grade infections after shoulder arthroplasty. The excellent specificity of 95% ensures, however, that non-infected prostheses are not incorrectly explanted. This study highlights that synovial biopsy has a high diagnostic value and should be done prior to complex revision surgeries to raise sensitivity in diagnosing a PJI.

Arthroscopic modified Broström operation versus open reconstruction with local periosteal flap in chronic ankle instability.

INTRODUCTION: The modified Broström operation (MBO) has found widespread use in the therapy of lateral chronic ankle instability (CAI). However, alternative surgical techniques like the open reconstruction using a periosteal flap (RPF) are still an important part of the surgical treatment of lateral CAI. Both procedures differ in terms of the reconstruction material used and the surgical procedure. Comparative studies on the surgical therapy of CAI are limited and generally refer to similar surgical procedures. Aim of this study was to compare the arthroscopic MBO and the RPF. MATERIALS AND METHODS: We retrospectively analysed 25 patients with lateral CAI after a tear of the anterior talofibular ligament (ATFL). 14 patients received arthroscopic MBO and 11 patients received RPF. We compared the postoperative outcome between both groups with respect to subjective instability, the number of ankle sprains, pain, complications and follow-up operations as well as the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score. RESULTS: Both surgical procedures resulted in a significant improvement in pain, in subjective instability, in the reduction in the frequency of ankle sprains and improvement in the AOFAS ankle-hindfoot score one year postoperatively. Three months postoperatively, the values for pain and instability of the MBO group were significantly better compared to the RPF. One year after the operation, these differences were evened out. Also in terms of complications and follow-up operations, no significant difference was found between the two procedures. CONCLUSIONS: Both surgical procedures give very good results one year postoperatively in terms of pain, instability, function and complication rate. With significantly better results regarding pain and instability three months postoperatively, the MBO allows a faster recovery in patients operated with this technique.

Influence of reduction accuracy in lateral tibial plateau fractures on intra-articular friction - a biomechanical study.

BACKGROUND: Lateral tibial split fractures (LTSF) usually require surgical therapy with screw or plate osteosynthesis. Excellent anatomical reduction of the fracture is thereby essential to avoid post-traumatic osteoarthritis. In clinical practice, a gap and step of 2 mm have been propagated as maximum tolerable limit. To date, biomechanical studies regarding tibial fractures have been limited to pressure measurement, but the relationship between dissipated energy (DE) as a friction parameter and reduction accuracy in LTSF has not been investigated. In past experiments, we developed a new method to measure DE in ovine knee joints. To determine weather non-anatomical fracture reduction with lateral gap or vertical step condition leads to relevant changes in DE in the human knee joint, we tested the applicability of the new method on human LTSFs and investigated whether the current limit of 2 mm gap and step is durable from a biomechanical point of view. METHODS: Seven right human, native knee joint specimens were cyclically moved under 400 N axial load using a robotic system. During the cyclic motion, the flexion angle and the respective torque were recorded and the DE was calculated. First, DE was measured after an anterolateral approach had been performed (condition "native"). Then a LTSF was set with a chisel, reduced anatomically, fixed with two set screws and DE was measured ("even"). DE of further reductions was then measured with gaps of 1 mm and 2 mm, and a 2 mm step down or a 2 mm step up was measured. RESULTS: We successfully established a measurement protocol for DE in human knee joints with LTSF. While gaps led to small though statistically significant increase (1 mm gap:ΔDE compared with native = 0.030 J/cycle, (+ 21%), p = 0.02; 2 mm gap:ΔDE = 0.032 J/cycle, (+ 22%), p = 0.009), this increase almost doubled when reducing in a step-down condition (ΔDE = 0.058 J/cycle, (+ 56%), p = 0.042) and even tripled in the step-up condition (ΔDE = 0.097 J/cycle, (+ 94%), p = 0.004). CONCLUSIONS: Based on our biomechanical findings, we suggest avoiding step conditions in the daily work in the operating theatre. Gap conditions can be handled a bit more generously.

Transfer of plantar pressure from the medial to the central forefoot in patients with hallux valgus.

BACKGROUND: The aim of the study was to evaluate changes in plantar pressure distribution in feet affected by hallux valgus compared with their contralateral non-affected feet and with the feet of healthy control subjects. METHODS: Thirty-six patients with unilateral hallux valgus who were indicated for surgery and 30 healthy subjects were assessed on a pedobarographic instrumented treadmill for step length and width, mean stance phase, and plantar foot pressure distribution. Plantar pressure distribution was divided into eight regions. RESULTS: Significantly higher plantar pressures were observed in hallux valgus feet under the second and third metatarsal heads (p = .033) and the fourth and fifth toes (p < .001) than in the healthy control feet. Although decreased pressures were measured under the hallux in affected feet (197 [82-467] kPa) in contrast to the contralateral side (221 [89-514] kPa), this difference failed to reach statistical significance (p = .055). The gait parameters step width, step length, and single-limb support did not show any differences between hallux valgus and control feet. CONCLUSION: Although the literature on changes in plantar pressures in hallux valgus remains divided, our findings on transferring load from the painful medial to the central and lateral forefoot region are consistent with the development of transfer metatarsalgia in patients with hallux valgus.

Inpatient gradual diagnostics and its relevance for determining treatment strategies in lumbar back pain.

BACKGROUND: Identifying patients who will benefit from spine surgery is still a challenge. This is especially the case when patients' complaints and medical history, together with clinical observations, do not correspond to structural pathological changes. With inpatient gradual diagnostics (IGD)-the administration of analgesic and anti-inflammatory agents to a special area of interest-the effect of surgery can be temporarily simulated. From the patient's statement about the alleviation of pain, the surgeon can draw conclusions concerning its causes. The aim of this study was to evaluate the extent to which IGD influences the decision about the nature and scope of surgical treatment strategies, and the way in which it does so, in patients with chronic lumbar back pain. METHODS: Clinical history and radiologic images were analysed retrospectively in 116 patients by two spine surgeons. Two therapeutic recommendations were developed for each patient: one was based on knowledge before IGD and one on knowledge after IGD. RESULTS: IGD changed the treatment strategy in 39 % of the analysed cases. Although the rate of recommended surgery was reduced by about 10 %, the indicated surgical scope increased in 25 % of cases. CONCLUSIONS: IGD is an established concept used to determine therapeutic strategies in patients with chronic lumbar back pain. In our analysed cases, IGD led to highly relevant changes in recommendations for further surgical treatment.

Driving and emergency braking may be impaired after tibiotalar joint arthrodesis: conclusions after a case series.

PURPOSE: To assess whether reaction time (RT) and movement time (MT), as the two components of the total brake response time (TBRT) and brake force (BF) are different in patients with a foot joint arthrodesis in comparison to controls. METHODS: The study was a comparative case series in a driving simulator under realistic driving conditions. Mobile patients without a walker, ≥6 months after surgery who were driving a car and had no neurological co-morbidity, knee or hip joint prosthesis were included in the study. The selection criteria resulted in 12 patients with right tibiotalar joint arthrodesis (TTJA) and 12 patients with another right foot joint arthrodesis (OFJA), who were compared to 17 individuals without any ankle-joint pathology. For TBRT, an empirical safe driving threshold of 700 ms was used. The outcome measures were RT, MT, TBRT, BF and McGuire score. RESULTS: MT (p = 0.034) and TBRT (p = 0.026) were longer in TTJA patients in comparison with the controls. Also, more patients with TTJA than patients with OFJA and controls exceeded the safe driving threshold (p = 0.028). The outcomes in OFJA patients and in controls were comparable. The McGuire score was similar between the TTJA and OFJA patients (p = 0.26). CONCLUSIONS: Significantly slower MT and TBRT, and significantly more patients exceeding the safe driving threshold, were observed after a tibiotalar-joint arthrodesis in comparison to the controls. Patients with OFJAs were not significantly different from the controls. Driving and emergency braking may be impaired after tibiotalar-joint arthrodesis.

Influence of left- and right-side total hip arthroplasty on the ability to perform an emergency stop while driving a car.

OBJECTIVE: To show the possible effect of left- and right-side total hip arthroplasty (THA) on the ability to perform an emergency stop when driving a car. DESIGN: Inception cohort. SETTING: A driving simulator using an actual car cabin, specifically developed for the experiment, was used for testing driving ability. PARTICIPANTS: Patients (N=40; 20 left-side THA/20 right-side THA) were tested preoperatively and in increments of 8 days and 6, 12, and 52 weeks after surgery. INTERVENTIONS: Left- and right-side THA. MAIN OUTCOME MEASURES: Reaction time, movement time, total brake response time (TBRT), and maximum brake force. RESULTS: Eight days postoperatively, measurements on driving performance indicated a slight worsening for all outcome parameters in patients after left-side THA and considerably more worsening in patients after right-side THA. For both patient groups, significant improvements in outcome measures were noted during the 1-year follow-up. Brake force declined significantly in patients with left-side THA (P=.012) and in patients after right-side THA (P<.001). A total of 35% of the patients with right-side THA and 15% with left-side THA could not meet the 600 ms TBRT threshold 6 weeks postoperatively. CONCLUSIONS: Most patients who underwent right-side THA reached their preoperative baseline 6 weeks after surgery. Most of the patients with left-side THA showed no TBRT limitations 8 days postoperatively. Because of the patients' highly individual rehabilitation course and considering the possible consequences of the premature resumption of driving a motor vehicle, individual examination and recommendation are necessary.

Osteoarthritis of the knee or hip significantly impairs driving ability (cross-sectional survey).

BACKGROUND: Advising patients about when they can drive after surgery is common practice after arthroplasty of the knee or hip. In the literature, the preoperative braking performance values of the patients are frequently taken as the "safe" landmark. We hypothesised that osteoarthritis (OA), the most frequent reason for arthroplasty, already compromises the ability to perform an emergency stop. We expected that both Reaction Time (RT) and Movement Time (MT) as components of the Total Brake Response Time (TBRT), would be prolonged in patients with OA of the knee or hip in comparison with healthy subjects. We also expected maximum pressure levels on the brake pedal to be reduced in such cases. METHODS: A real car cabin was equipped with pressure sensors on the accelerator and brake pedals to measure RT, MT, TBRT and maximum Brake Force (BF) under realistic spatial constraints. Patients with OA of the knee (right n = 18, left n = 15) or hip (right n = 20, left n = 19) were compared with a healthy control group (n = 21). RESULTS: All measured values for TBRT in the control group remained below 600 ms. OA of the right hip or knee significantly prolonged the braking performance (right hip: TBRT p = 0.025, right knee: TBRT p < 0.001), whereas OA of the left hip did not impair driving ability (TBRT p = 0.228). Intriguingly, OA of the left knee prolonged RT and MT to the same degree as OA on the contralateral side (RT p = 0.001, MT p < 0.001). CONCLUSIONS: This study demonstrates that depending on the localisation of OA, driving capability can be impaired; OA can significantly increase the total braking distance. To ensure safe traffic participation the safety margin for TBRT should be strictly set, under our experimental conditions, at around 600 ms. Moreover, therapeutic approaches to OA, such as physiotherapy, and patients receiving surgery of the left knee should take into account that left knee OA can also impair driving ability. CLINICAL TRIAL REGISTRATION NUMBER: Project number of the ethics committee of the University of Tübingen: 268/2009BO2; 267/2009BO2.

Diagnostic and prognostic relevance of plain radiographs for periprosthetic joint infections of the hip: a literature review.

Conventional radiography is regularly used to evaluate complications after total hip arthroplasty. In various recent consensus meetings, however, plain radiographs of a potentially infected hip joint have been judged as being only relevant to exclude diagnoses other than infection. Solid data on radiographic presentations of periprosthetic joint infection (PJI) are scarce. As a result, the prognostic value of radiological features in low-grade PJI remains uncertain. The present review article aims to present an overview of the available literature and to develop ideas on future perspectives to define the diagnostic possibilities of radiography in PJIs of the hip. The primary outcome of interest of this systematic review was the radiologic presentation of periprosthetic joint infections of the hip. As secondary outcome of interest served the sensitivity and specificity of the radiologic presentation of periprosthetic joint infections. Of the included articles, 26 were reviews, essays, or case reports and only 18 were clinical studies. Typical radiologic abnormalities of PJI were a periosteal reaction, a wide band of radiolucency at the cement-bone or metal-bone interface, patchy osteolysis, implant loosening, bone resorption around the implant, and transcortical sinus tracts. The frequency of their occurrence is still inadequately defined. A deeper understanding of the underlying causes and the relation between microorganisms to radiologic abnormalities can probably help clinicians in the future to diagnose a PJI. This is why further research shall focus on the radiographic features of PJI.

Minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient-acceptable symptom state (PASS) in patients who have undergone total knee arthroplasty: a systematic review.

BACKGROUND: The present systematic review investigated the minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient-acceptable symptom state (PASS) of several frequent and established PROMs used to assess patients who have undergone TKA. This study was conducted according to the 2020 PRISMA statement. METHODS: In September 2023, PubMed, Web of Science, and Embase were accessed with no time constraint All clinical studies investigating tools to assess the clinical relevance of PROMs used to evaluate patients having received TKA were accessed. Only studies which evaluated the MCID, PASS, or SCB were eligible. The PROMs of interest were the Forgotten Joint Score-12 (FJS-12), the Oxford Knee Score (OKS), the Knee Injury and Osteoarthritis Outcome Score (KOOS) and its related subscales activity of daily living (ADL), pain, quality of life (QoL), sports and recreational activities, and symptoms, the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) score, the Knee Society Score (KSS) and related function score, and the Short Form-12 (SF-12) and Short Form-36 (SF-36). RESULTS: Data from 29,737 patients were collected. The overall risk of bias was low to moderate. The great variability of thresholds for MCID, SCB and PASS between questionnaires but also between investigated aspects was noted, whereby MCIDs for the SF-36 appear lower than for knee-specific questionnaires. CONCLUSION: Despite its critical role from a patient's perspective, the dimension of SCB is still neglected in the literature. Moreover, thresholds for the different concepts need to be condition-specific. We encourage authors to specifically report such data in future studies and to adhere to previously reported definitions to allow future comparison. Level of evidence Level IV, systematic review and meta-analysis.

Proteolysis of the pericellular matrix: Pinpointing the role and involvement of matrix metalloproteinases in early osteoarthritic remodeling.

The pericellular matrix (PCM) serves a critical role in signal transduction and mechanoprotection in chondrocytes. Osteoarthritis (OA) leads to a gradual deterioration of the cartilage, marked by a shift in the spatial arrangement of chondrocytes from initially isolated strands to large cell clusters in end-stage degeneration. These changes coincide with progressive enzymatic breakdown of the PCM. This study aims to assess the role and involvement of specific matrix metalloproteinases (MMPs) in PCM degradation during OA. We selected cartilage samples from 148 OA patients based on the predominant spatial chondrocyte patterns. The presence of various MMPs (-1,-2,-3,-7,-8,-9,-10,-12,-13) was identified by multiplexed immunoassays. For each pattern and identified MMP, the levels and activation states (pro-form vs. active form) were measured by zymograms and western blots. The localization of these MMPs was determined using immunohistochemical labeling. To verify these results, healthy cartilage was exposed to purified MMPs, and the consecutive structural integrity of the PCM was analyzed through immunolabeling and proximity ligation assay. Screening showed elevated levels of MMP-1,-2,-3,-7, and -13, with their expression profile showing a clear dependency of the degeneration stage. MMP-2 and -7 were localized in the PCM, whereas MMP-1,-7, and -13 were predominantly intracellular. We found that MMP-2 and -3 directly disrupt collagen type VI, and MMP-3 and -7 destroy perlecan. MMP-2, -3, and -7 emerge as central players in early PCM degradation in OA. With the disease's initial stages already displaying elevated peaks in MMP expression, this insight may guide early targeted therapies to halt abnormal PCM remodeling. STATEMENT OF SIGNIFICANCE: Osteoarthritis (OA) causes a gradual deterioration of the articular cartilage, accompanied by a progressive breakdown of the pericellular matrix (PCM). The PCM's crucial function in protecting and transmitting signals within chondrocytes is impaired in OA. By studying 148 OA-patient cartilage samples, the involvement of matrix metalloproteinases (MMPs) in PCM breakdown was explored. Findings highlighted elevated levels of certain MMPs linked to different stages of degeneration. Notably, MMP-2, -3, and -7 were identified as potent contributors to early PCM degradation, disrupting key components like collagen type VI and perlecan. Understanding these MMPs' roles in initiating OA progression, especially in its early stages, provides insights into potential targets for interventions to preserve PCM integrity and potentially impeding OA advancement.

Reliability and Accuracy of the Outerbridge Classification in Staging of Cartilage Defects.

OBJECTIVE: The decision on whether or not and how to treat a local cartilage defect is still made intraoperatively based on the visual presentation of the cartilage and findings from indentations with an arthroscopic probe. The treatment decision is then usually based on grading according to established classifications systems, which, therefore, need to have high reliability and accuracy. The aim of the present study was to evaluate the reliability and accuracy of the Outerbridge classification in staging cartilage defects. METHODS: We performed an observer arthroscopic study using the Outerbridge classification on seven fresh-frozen human cadaveric knees, which collectively exhibited nine cartilage defects. To evaluate accuracy, defect severity was verified through histological examination. Interrater and intrarater reliabilites were calculated using Cohen's kappa and the intra-class correlation coefficient (ICC 3.1). RESULTS: The interrater and intrarater reliability for the Outerbridge classification ranged from poor to substantial, with 0.24 ≤ κ ≤ 0.70 and κ = 0.55 to κ = 0.66, respectively. The accuracy evaluated by comparison with the histological examination was 63% overall. The erroneous evaluations were, however, still often at the discrimination of grade 2 and 3. We did not find any relationship between higher experience and accuracy or intraobserver reliability. Taken together, these results encourage surgeons to further use diagnostic arthroscopy for evaluating cartilage lesions. Nevertheless, especially in grade 2 and 3, deviations from the histology were observed. This is, however, the point where a decision is made on whether to surgically address the defect or not. CONCLUSION: Diagnostic arthroscopy is the standard for cartilage lesion assessment, yet interobserver reliability is fair to substantial. Caution is warranted in interpreting varied observer results. The accuracy of the "simpler" Outerbridge classification is insufficient compared to histological examinations, highlighting the need for improved techniques in guideline-based intraoperative decision-making.

Fostering Excellence in Knee Arthroplasty: Developing Optimal Patient Care Pathways and Inspiring Knowledge Transfer of Advanced Surgical Techniques.

Osteoarthritis of the knee is common. Early sports trauma or cartilage defects are risk factors for osteoarthritis. If conservative treatment fails, partial or total joint replacement is often performed. A joint replacement aims to restore physiological biomechanics and the quality of life of affected patients. Total knee arthroplasty is one of the most performed surgeries in musculoskeletal medicine. Several developments have taken place over the last decades that have truly altered the way we look at knee arthroplasty today. Some of the fascinating aspects will be presented and discussed in the present narrative review.