Pulsed lavage is associated with better quality of bone-cement-implant interface in knee arthroplasties (TKA/UKA) compared to syringe lavage in vitro; however, clinical data are missing: A systematic review

Purpose

The purpose of this systematic review is to analyse the available literature to ascertain the optimal method of bone preparation to improve the quality of bone-cement-implant interface with either pulsed lavage or syringe lavage in both total knee arthroplasty (TKA) and unicompartmental knee arthroplasty (UKA).

Methods

A comprehensive search was conducted across MEDLINE, Scopus and Embase databases until July 2023. Both inclusion and exclusion criteria were clearly stated and used to identify all the published studies. Subsequent screening throughout the title, abstract and full text was made, followed by complete critical appraisal and data extraction. This sequential process was performed by two reviewers independently and summarised following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines). A quality assessment of the systematic review was performed according to the Quality Appraisal for Cadaveric Studies scale (QUACS), reaching a quality level ranging from 69% to 85%.

Results

A total of 10 articles, out of 47, nine biomechanical cadaveric studies and one human clinical study were analysed. A total of 196 UKA tibial components, 74 patellar components, 36 TKA tibial components and 24 UKA femoral components were retrieved, and a high level of heterogeneity resulted overall. The pulsed lavage group showed better cement penetration and higher pull-out force than the syringe lavage group; a higher interface temperature was also found in the pulsed lavage group. No differences were found regarding tension ligament forces between the groups.

Conclusion

Our systematic review suggests that pulsed lavage is superior to syringe lavage in terms of the quality of bone-cement-implant interface in knee arthroplasties (TKA/UKA). However, translation of these results from cadaveric studies to individual clinical settings may be hazardous; therefore, clinical in vivo prospective studies are highly needed.

PROSPERO CRD

PROSPERO CRD number CRD42023432399.

Level of Evidence

Level III.

Stereotactic body radiotherapy for centrally located inoperable early-stage NSCLC: EORTC 22113-08113 LungTech phase II trial results

BACKGROUND

The international EORTC phase II single-arm LungTech trial 22113-08113 assessed safety and efficacy of stereotactic body radiotherapy (SBRT) in patients with centrally located early-stage non-small cell lung cancer (NSCLC).

PATIENTS AND METHODS

Patients with inoperable non-metastatic central NSCLC (T1-T3 N0 M0, ≤7cm) were included. After prospective central imaging review and radiation therapy quality assurance (RTQA) for any eligible patient, SBRT (8x7.5 Gy, ICRU 83) was delivered. The primary endpoint was freedom from local progression probability at three years after start of SBRT.

RESULTS

The trial was closed earlier due to poor accrual related to repeated safety-related pauses in recruitment. Between 08/2015 and 12/2017, 39 patients from 6 European countries were included and 31 were treated per protocol and analyzed. Patients were mainly male (58%) with a median age of 75 years. Baseline comorbidities were mainly respiratory (68%) and cardiac (48%). Median tumor size was 2.6 cm (range, 1.2-5.5) and most cancers were T1 (51.6%) or T2a (38.7%) N0 M0 and of squamous cell origin (48.4%). Median follow-up was 3.6 years. The 3-year freedom from local progression and overall survival rates were 81.5% (90% CI: 62.7-91.4%) and 61.1% (90%CI: 44.1-74.4%), respectively. Cumulative incidence rates of local, regional and distant progression at 3 years were 6.7% (90% CI: 1.6-17.1%), 3.3% (90% CI: 0.4 - 12.4%) and 29.8% (90% CI: 16.8 - 44.1%), respectively. SBRT-related acute and late AEs ≥ G3 were reported in 6.5% (n=2, including one G5 pneumonitis in a patient with prior interstitial lung disease) and 19.4 % (n=6, including one lethal hemoptysis after a lung biopsy in a patient receiving anticoagulants), respectively.

CONCLUSION

The LungTech trial suggests that SBRT with 8×7.5Gy for central lung tumors in inoperable patients is associated with acceptable local control rates. However, late severe adverse events may occur after completion of treatment. This SBRT regimen is a viable treatment option after thorough risk-benefit discussion with patients. To minimize potentially fatal toxicity, careful management of dose constraints and post-SBRT interventions is crucial.

Fractionated stereotactic radiotherapy of intracranial postoperative cavities after resection of brain metastases - Clinical outcome and prognostic factors

Background and Purpose

After surgical resection of brain metastases (BM), radiotherapy (RT) is indicated. Postoperative stereotactic radiosurgery (SRS) reduces the risk of local progression and neurocognitive decline compared to whole brain radiotherapy (WBRT). Aside from the optimal dose and fractionation, little is known about the combination of systemic therapy and postoperative fractionated stereotactic radiotherapy (fSRT), especially regarding tumour control and toxicity.

Methods

In this study, 105 patients receiving postoperative fSRT with 35 Gy in 7 fractions performed with Cyberknife were retrospectively reviewed. Overall survival (OS), local control (LC) and total intracranial brain control (TIBC) were analysed via Kaplan-Meier method. Cox proportional hazards models were used to identify prognostic factors.

Results

Median follow-up was 20.8 months. One-year TIBC was 61.6% and one-year LC was 98.6%. Median OS was 28.7 (95%-CI: 16.9-40.5) months. In total, local progression (median time not reached) occurred in 2.0% and in 20.4% radiation-induced contrast enhancements (RICE) of the cavity (after median of 14.3 months) were diagnosed. Absence of extracranial metastases was identified as an independent prognostic factor for superior OS (p = <0.001) in multivariate analyses, while a higher Karnofsky performance score (KPS) was predictive for longer OS in univariate analysis (p = 0.041). Leptomeningeal disease (LMD) developed in 13% of patients.

Conclusion

FSRT after surgical resection of BM is an effective and safe treatment approach with excellent local control and acceptable toxicity. Further prospective randomized trials are needed to establish standardized therapeutic guidelines.

Artificial Intelligence-Based Emphysema Quantification in Routine Chest Computed Tomography: Correlation With Spirometry and Visual Emphysema Grading

OBJECTIVE

The aim of the study is to assess the correlation between artificial intelligence (AI)-based low attenuation volume percentage (LAV%) with forced expiratory volume in the first second to forced vital capacity (FEV1/FVC) and visual emphysema grades in routine chest computed tomography (CT). Furthermore, optimal LAV% cutoff values for predicting a FEV1/FVC < 70% or moderate to more extensive visual emphysema grades were calculated.

METHODS

In a retrospective study of 298 consecutive patients who underwent routine chest CT and spirometry examinations, LAV% was quantified using an AI-based software with a threshold < -950 HU. The FEV1/FVC was derived from spirometry, with FEV1/FVC < 70% indicating airway obstruction. The mean time interval of CT from spirometry was 3.87 ± 4.78 days. Severity of emphysema was visually graded by an experienced chest radiologist using an established 5-grade ordinal scale (Fleischner Society classification system). Spearman correlation coefficient between LAV% and FEV1/FVC was calculated. Receiver operating characteristic determined the optimal LAV% cutoff values for predicting a FEV1/FVC < 70% or a visual emphysema grade of moderate or higher (Fleischner grade 3-5).

RESULTS

Significant correlation between LAV% and FEV1/FVC was found (ϱ = -0.477, P < 0.001). Increasing LAV% corresponded to higher visual emphysema grades. For patients with absent visual emphysema, mean LAV% was 2.98 ± 3.30, for patients with trace emphysema 3.22 ± 2.75, for patients with mild emphysema 3.90 ± 3.33, for patients with moderate emphysema 6.41 ± 3.46, for patients with confluent emphysema 9.02 ± 5.45, and for patients with destructive emphysema 16.90 ± 8.19. Optimal LAV% cutoff value for predicting a FEV1/FVC < 70 was 6.1 (area under the curve = 0.764, sensitivity = 0.773, specificity = 0.665), while for predicting a visual emphysema grade of moderate or higher, it was 4.7 (area under the curve = 0.802, sensitivity = 0.766, specificity = 0.742). Furthermore, correlation between visual emphysema grading and FEV1/FVC was found. In patients with FEV1/FVC < 70% a high proportion of subjects had emphysema grade 3 (moderate) or higher, whereas in patients with FEV1/FVC ≥ 70%, a larger proportion had emphysema grade 3 (moderate) or lower. The sensitivity for visual emphysema grading predicting a FEV1/FVC < 70% was 56.3% with an optimal cutoff point at a visual grade of 4 (confluent), demonstrating a lower sensitivity compared with LAV% (77.3%).

CONCLUSIONS

A significant correlation between AI-based LAV% and FEV1/FVC as well as visual CT emphysema grades can be found in routine chest CT suggesting that AI-based LAV% measurement might be integrated as an add-on functional parameter in the evaluation of chest CT in the future.

Robotic-assisted total knee arthroplasty is not associated with improved accuracy in implant position and alignment compared to conventional instrumentation in the execution of a preoperative digital plan

Purpose

The primary objective of the present study was to evaluate if robotic-assisted total knee arthroplasty (RO-TKA) results in improved accuracy compared to conventional TKA (CO-TKA) with respect to alignment and component positioning executing a preoperative digital plan. The secondary objective was to compare patient-reported outcome measures (PROMs) between the two groups at 6 months of follow-up (FU).

Methods

Patients who underwent primary TKA using the concept of constitutional alignment were identified from the database. Each patient underwent preoperative digital planning as well as postoperative evaluation of the preoperative plan (alignment and component position) using mediCAD® software (Hectec GmbH). Two groups were formed: (i) The RO-TKA group (n = 30) consisted of patients who underwent TKA with a robotic surgical system (ROSA®, Zimmer Biomet) and (ii) the CO-TKA group (n = 67) consisted of patients who underwent TKA with conventional instrumentation. To assess accuracy, all qualitative variables were analysed using the χ 2 test. Tegner activity scale, Oxford Knee Score and visual analogue scale were assessed preop and at 6-month FU. To assess differences between the two groups, a 2 × 2 repeated measures analysis of variance was performed.

Results

There was no significant (p > 0.05) difference in the accuracy of alignment as well as tibial and femoral component position between the two groups. At the 6-month FU, there was no significant (p > 0.05) difference in PROMs between the two groups.

Conclusion

While robotic TKA may have some potential advantages, no significant difference was found between robotic and conventional TKA with respect to limb alignment, clinical outcomes and component positioning.

Level of Evidence

Level III.

A slight degree of osteoarthritis appears to be present after anterior cruciate ligament reconstruction compared with contralateral healthy knees at a minimum of 20 years: A systematic review of the literature

Purpose

The aim of the present systematic review was to quantitatively synthesize the best literature evidence regarding osteoarthritis developing after anterior cruciate ligament reconstruction (ACLR), including only studies with a follow-up duration of at least 20 years.

Material and Methods

A systematic review was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines on four electronic databases (PubMed, Scopus, EMBASE and Cochrane Library). The outcome measures extracted from the studies were failure rate, subsequent knee surgery on the same knee, radiographic development of osteoarthritis measured with Kellgren-Lawrence, International Knee Documentation Committee (IKDC) radiographic score and Ahlbäck classification. The health of both the ACLR knee and the contralateral knee was compared.

Results

A total of 1552 patients were included in the study, of which 1290 (83.11%) were operated on using a patellar tendon graft, 190 (12.24%) with hamstrings, 27 (1.73%) with an iliotibial band and 45 (2.89%) with patellar tendon plus a ligament augmentation device (LAD). The mean age at the time of surgery was 25.18 ± 1.91 years, and the mean follow-up time was 23.34 ± 2.56 years. Analysing IDKC Score at final follow-up, ACLR Group showed a higher degree of OA compared with contralateral healthy knee (p < 0.01), but only 33.2% (324/976) of the patients showed a moderate to severe degree (Grade C or D) of osteoarthritis, while for Kellgren-Lawrence, ACLR Group showed a higher degree of OA compared with contralateral healthy knee (p < 0.01), but only 28.9% (196/678) of the patients showed a moderate to severe degree (Grade III or IV) of osteoarthritis. In total, 1552 patients were registered, 155 reruptures (9.98%) and a total of 300 (19.3%) new surgeries, of which 228 meniscectomy (14.69%), 21 (1.35%) knee arthroplasty and 17 (1.09%) hardware removal were recorded.

Conclusions

ACL reconstruction appears to result in mild osteoarthritis in the long term in most of the patients and only less than 33.2% develop a moderate to severe degree of knee OA according to IKDC radiographic score. A slight degree of osteoarthritis appears to be present in ACLR knees compared with contralateral healthy knees.

Level of Evidence

Level IV.

The "Golden Age" of quadriceps tendon grafts for the anterior cruciate ligament: a bibliometric analysis

IMPORTANCE

Bibliometric research is a statistical analysis of publications to measure the scientific output in a specific field in order to highlight medical developments or knowledge gaps and to direct future scientific research. The quantity of orthopedic papers on the internet is astounding and is steadily growing as a result of recent advancements in technology and medicine. This is why choosing the right information is essential.

AIM

The purpose of this study was to analyze the current literature for trends in publications regarding quadriceps tendon (QT) grafting of the anterior cruciate ligament (ACL).

EVIDENCE REVIEW

PubMed was searched on August 28, 2023. References were collected from PubMed, and trends were analyzed using this information. This search retrieved 405 articles regarding human and animal studies. We analyzed the top 10 authors and journals in terms of publication numbers, citation numbers, and citations per year. The PubMed-by-year feature was used to compare the number of publications regarding ACL reconstruction by quadriceps grafting with all publications in PubMed.

FINDINGS

The number of yearly publications averaged 10 or less up to 2018, starting from 1982 when the first paper on the QT was published. However, the number of publications increased from 2018. While the total number of publications on this topic was 405, 260 were published from 2018 alone. The number of citations was 8262 in total overall years. It is expected that the last five years' publications, especially those for the last year, will be low in number, as it takes time for citations to accrue. The journal Arthroscopy published the most articles on this topic, with 57 papers and 1884 citations, followed by the American Journal of Sports Medicine, with 39 articles and 1576 citations. The top three journals on this topic were Arthroscopy, AmericanJournalofSportsMedicine, and KneeSurgery, SportsTraumatology, Arthroscopy. The most published author was Musahl V (with 24 articles), and the most cited author was Xerogeanes JW (with 570 citations).

CONCLUSIONS AND RELEVANCE

Global trend analysis suggests that research on anterior cruciate ligament reconstruction with the quadriceps has significantly increased in the last 5 years and that the number of papers on this topic is increasing steadily. We found that the publications and citations are exhibiting a rising trend, Arthroscopy is the most impactful journal, and Musahl V is the most impactful author on the topic. Xerogeanes JW is the author with the most citations on the topic. The promising clinical results of anterior cruciate ligament reconstruction with the QT have attracted the most research interest.

LEVEL OF EVIDENCE

Level IV.

Medial Patellofemoral Ligament Reconstruction Using Pedicled Quadriceps Tendon Autograft Yields Similar Clinical and Patient-Reported Outcomes but Less Donor-Site Morbidity Compared With Gracilis Tendon Autograft

PURPOSE

To compare clinical and patient-reported outcome measures (PROMs) in patients with recurrent patellar dislocation after medial patellofemoral ligament (MPFL) reconstruction using either a gracilis tendon (GT) or quadriceps tendon autograft (QT).

METHODS

All MPFL reconstruction performed between 2017 and 2019 were reviewed retrospectively. Only patients with isolated MPFL reconstruction, without any major patellofemoral risk factors and a minimum follow-up of 24 months, were included in the study. Patients were matched with respect to sex, age, and body mass index. All patients were evaluated clinically and using PROMs.

RESULTS

A total of 64 patients with an average follow up of 28.7 ± 7.5 months were included in this study. The mean Kujala score (GT: 84.8 ± 12.9, QT: 88.9 ± 10.1), Lysholm score (GT: 89.4 ± 10.2, QT: 88.4 ± 5.0), and visual analog scale score for pain (GT: 1.9 ± 1.8, QT: 1.1 ± 1.3) did not significantly differ between both groups. Tegner activity level was significantly greater (P = .027) in the QT group (5.5 ± 1.9) compared with the GT group (4.6 ± 1.8), but within the minimal clinically important differences. Occasional patellar instability events, but no recurrent dislocation, were reported in 12.5% in the GT group and 6.3% in the QT group (P = .39). Of all patients, 90.6% in the QT and 68.8% in the HT group exceeded the PASS for the Kujala score (P = .06). Significantly more patients (59.4%) treated with GT reported donor-site morbidity in the form of sensitivity deficit at the lower leg compared with those treated with QT (3.1%, P = .001).

CONCLUSIONS

GT and QT MPFL reconstruction have comparable PROMs and patellar redislocation rates 2 years' postoperatively. Significantly more patients treated with GT reported lower-leg sensitivity deficit compared with those treated with QT.

LEVEL OF EVIDENCE

Level III, retrospective case-control study.

Primary Versus Revision ACL Reconstruction Using Quadriceps Autograft: A Matched-Control Cohort Study

Background

The incidence of anterior cruciate ligament (ACL) reconstruction is increasing, and quadriceps tendon (QT) autograft is gaining popularity for both primary and revision ACL reconstruction.

Purpose

To evaluate the differences in the patient-reported functional outcomes, concomitant injuries, and graft failure in primary versus revision ACL surgery using QT autograft.

Study Design

Cohort study; Level of evidence, 3.

Methods

A total of 376 patients with primary ACL reconstruction and 138 patients with revision ACL reconstruction were retrospectively retrieved from a prospectively collected ACL registry. A minimally invasive technique was used for QT autograft harvesting. The surgical procedure and rehabilitation protocol were identical in both groups. To maintain a homogeneous cohort for the study, the groups were matched by age, sex, and preinjury outcome scores (Lysholm knee score, Tegner activity level, and visual analog scale [VAS] for pain). Initial baseline assessments of outcome scores were compared with scores collected at the 2-year postoperative mark.

Results

The mean age of the primary group and revision group was 32.9 ± 10.2 years (range, 18-55 years) and 32.3 ± 9.9 years (range, 19-55 years) respectively. Significant preinjury to postoperative improvements were noted in Lysholm (88.2 ± 16.4 vs 83.5 ± 15.0; P = .007) and VAS pain (0.9 ± 1.3 vs 1.5 ± 1.6; P = .001) scores after primary ACL reconstruction compared with revision reconstruction. However, no significant difference was found in Tegner activity level (6.7 ± 1.8 vs 5.9 ± 1.8; P > .430). Primary ACL injury was associated with significantly higher concomitant medial collateral ligament injuries (P = .019), while the revision group was associated with significantly higher concomitant cartilage (P = .001) and meniscal (P = .003) injuries. A significantly higher graft failure rate was noted in the revision group compared with the primary ACL reconstruction group (13.0% vs 5.6%; P = .005).

Conclusion

Both primary and revision ACL reconstruction with QT autograft had acceptable functional outcomes. The primary group had better outcomes than the revision group, possibly due to the lower prevalence of meniscal and cartilage injuries in the primary group compared with the revision group. The revision group was associated with higher graft failure than the primary group. QT autograft is a viable graft choice for both primary and revision ACL reconstruction.

Increased Intra-Articular Internal Tibial Rotation Is Associated With Unstable Medial Meniscus Ramp Lesions in ACL-Injured Athletes: An MRI Matched-Pair Comparative Study

Purpose

To analyze internal tibial rotation through magnetic resonance imaging (MRI) of patients with anterior cruciate ligament (ACL) injuries with and without an unstable medial meniscal ramp lesion (MMRL).

Methods

Retrospective analysis of prospectively data was performed to include all consecutive patients who underwent primary ACL reconstruction (ACLR) between January 2022 and June 2022. Two groups, ACLR + unstable MMRL and ACLR without MMRL, were constituted. Propensity score matching analysis was used to limit selection bias. The angle between surgical epicondylar axes (SEAs) and the tangent line of the posterior tibial condyles (PTCs) was measured to analyze the rotational alignment between distal femur and proximal tibia. MMRLs were defined unstable if they were ≥1 cm, if the lesions extend beyond the lower pole of the femoral condyle, and/or if there was displacement into the medial compartment by anterior probing.

Results

Twenty-eight propensity-matched pairs were included. The ACLR + unstable MMRL presented a significantly greater internal rotation of the tibia compared to ACLR without MMRL (P < .001). An internal tibial rotation was associated with unstable ramp lesions in ACL-injured patients (odds ratio [OR], 0.36; 95% CI, 0.25-0.41; P < .0001). If SEA-PTC was 0°, the sensitivity and specificity of the SEA-PTC angle to detect unstable MMRL were respectively 100% (95% CI, 85%-100%) and 18% (95% CI, 8%-36%). Otherwise, if SEA-PTC angle was -10°, the sensitivity and specificity of the SEA-PTC angle to detect unstable MMRL were respectively 43% (95% CI, 27%-61%) and 96% (95% CI, 81%-100%). Bone edema of the posterior medial tibial plateau was significantly associated with unstable ramp lesions (OR, 1.58; 95% CI, 1.21-2.06; P = .029).

Conclusions

Unstable MMRL concomitant to an ACL rupture was associated with an increased tibial internal rotation.

Level of Evidence

Level III, retrospective comparative trial.

Quality of YouTube Videos Regarding Anterior Cruciate Ligament Reconstruction Using Quadriceps Tendon Autograft Is Unsatisfactory

PURPOSE

To assess the validity and informational value of teaching material regarding anterior cruciate ligament reconstruction (ACLR) using quadriceps tendon (QT) autograft provided on the YouTube video platform.

METHODS

An extensive systematic search of the YouTube video platform was performed, and all videos that met the criteria were included in the analysis. The analysis of the video content was performed using the DISCERN instrument, Journal of American Medical Association (JAMA) benchmark criteria, and Global Quality Score (GQS). The duration of the videos, the date of publication, and the number of likes and views were recorded. Furthermore, videos were categorized based on the source (physicians, companies, patients), the subject (surgical technique, patient experience and overview [overview videos were videos in which multiple aspects were analyzed]), and the type of content (educational or subjective patient experience).

RESULTS

A total of 88 videos were included in the analysis. Seventy-one (80.7%) videos were published by physicians, 15 (17.0%) by patients, and 2 (2.3%) by companies. The majority of the videos described various surgical techniques (59%-67.0%), 80.7% of the videos (72%-81.8%) had an educational nature, and the remaining 18.2% described patient experiences. The mean length of the videos was 8.21 ± 7.88 minutes. The mean number of views was 3,988.51 ± 9,792.98 (range 9-56,047), whereas the mean numbers of comments and likes were 30.07 ± 70.07 (range 0-493) and 4.48 ± 14.22 (range 0-82), respectively. The mean DISCERN score, JAMA score, and GQS were 27.43 ±11.56 (95% confidence interval [CI] 25.01-29.85; range: 17-68), 1.22 ± 0.85 (95% CI 1.04-1.40; range 0-3), and 1.82 ± 0.93 (95% CI 1.63-2.01; range 1-4), respectively. For all scores, videos published by physicians had greater quality (DISCERN score, JAMA score, and GQS) (P < .05). Among all of the analyzed videos, overview videos were of the highest quality (P < .05).

CONCLUSIONS

YouTube is a fast and open-access source of mass information. The overall quality of the videos on ACLR performed using QT autograft was unsatisfactory, demonstrating low educational quality and reliability. Currently, YouTube cannot be recommended as a reliable source of information on ACLR with the QT.

Distal Kaplan fibers and anterolateral ligament injuries are associated with greater intra-articular internal tibial rotation in ACL-deficient knees based on magnetic resonance imaging

PURPOSE

The purpose of the present study was to assess the internal rotation of the tibia on Magnetic Resonance Imaging (MRI) in a series of consecutive athletes with Anterior cruciate Ligament (ACL) tears.

METHODS

Retrospective analysis of prospectively collected data was performed to include all consecutive patients who had undergone primary ACL reconstruction between January 2022 and June 2022. The angle between surgical epicondylar axes (SEA) of the knee and posterior tibial condyles (PTC) was measured. A negative value was defined as internal torsion. KFs and ALL injuries were reported. Analysis of covariance (ANCOVA) was performed to examine the independent associations between SEA-PTC angle and injuries of KFs and ALL adjusted for physical variables (age, gender and body mass index [BMI]). Statistical significance was set at a p-value of < 0.05.

RESULTS

A total of 83 eligible patients were included. The result of multiple linear regression analysis showed that internal tibial rotation was associated with KFs and ALL injuries. The estimated average of SEA-PTC angle in relation to ALL injuries controlling the other variables was -5.49 [95%CI -6.79 - (-4.18)] versus -2.99 [95%CI -4.55 - (-1.44)] without ALL injuries. On the other hand, the estimated average of SEA-PTC angle in relation to KFs lesions controlling the other variables was -5.73 [95%CI -7.04 - (-4.43)] versus -2.75 [95%CI -4.31 - (-1.18)] without KFs injuries.

CONCLUSIONS

KFs and ALL injuries were associated with an increased intra-articular internal tibial rotation in ACL-deficient knees. The measurement of femorotibial rotation on axial MRI could be useful to detect indirect signs of anterolateral complex (ALC) injuries.

An integrated systems biology approach reveals differences in formate metabolism in the genus Methanothermobacter

Methanogenesis allows methanogenic archaea to generate cellular energy for their growth while producing methane. Thermophilic hydrogenotrophic species of the genus Methanothermobacter have been recognized as robust biocatalysts for a circular carbon economy and are already applied in power-to-gas technology with biomethanation, which is a platform to store renewable energy and utilize captured carbon dioxide. Here, we generated curated genome-scale metabolic reconstructions for three Methanothermobacter strains and investigated differences in the growth performance of these same strains in chemostat bioreactor experiments with hydrogen and carbon dioxide or formate as substrates. Using an integrated systems biology approach, we identified differences in formate anabolism between the strains and revealed that formate anabolism influences the diversion of carbon between biomass and methane. This finding, together with the omics datasets and the metabolic models we generated, can be implemented for biotechnological applications of Methanothermobacter in power-to-gas technology, and as a perspective, for value-added chemical production.

The "Bankart knee": high-grade impression fractures of the posterolateral tibial plateau lead to increased translational and anterolateral rotational instability of the ACL-deficient knee

PURPOSE

The aim of this biomechanical cadaver study was to evaluate the effects of high-grade posterolateral tibia plateau fractures on the kinematics of anterior cruciate ligament (ACL)-deficient joints; it was hypothesized that, owing to the loss of the integrity of the osseous support of the posterior horn of the lateral meniscus (PHLM), these fractures would influence the biomechanical function of the lateral meniscus (LM) and consequently lead to an increase in anterior translational and anterolateral rotational (ALR) instability.

METHODS

Eight fresh-frozen cadaveric knees were tested using a six-degree-of-freedom robotic setup (KR 125, KUKA Robotics, Germany) with an attached optical tracking system (Optotrack Certus Motion Capture, Northern Digital, Canada). After the passive path from 0 to 90° was established, a simulated Lachman test and pivot-shift test as well as external rotation (ER) and internal rotation (IR) were applied at 0°, 30°, 60° and 90° of flexion under constant 200 N axial loading. All of the parameters were initially tested in the intact and ACL-deficient states, followed by two different types of posterolateral impression fractures. The dislocation height was 10 mm, and the width was 15 mm in both groups. The intraarticular depth of the fracture corresponded to half of the width of the posterior horn of the lateral meniscus in the first group (Bankart 1) and 100% of the meniscus width in the second group (Bankart 2).

RESULTS

There was a significant decrease in knee stability after both types of posterolateral tibial plateau fractures in the ACL-deficient specimens, with increased anterior translation in the simulated Lachman test at 0° and 30° of knee flexion (p = 0.012). The same effect was seen with regard to the simulated pivot-shift test and IR of the tibia (p = 0.0002). In the ER and posterior drawer tests, ACL deficiency and concomitant fractures did not influence knee kinematics (n.s.).

CONCLUSION

This study demonstrates that high-grade impression fractures of the posterolateral aspect of the tibial plateau increase the instability of ACL-deficient knees and result in an increase in translational and anterolateral rotational instability.

Optical Measurement of Ligament Strain: Opportunities and Limitations for Intraoperative Application

A feasible and precise method to measure ligament strain during surgical interventions could significantly enhance the quality of ligament reconstructions. However, all existing scientific approaches to measure in vivo ligament strain possess at least one significant disadvantage, such as the impairment of the anatomical structure. Seeking a more advantageous method, this paper proposes defining medical and technical requirements for a non-destructive, optical measurement technique. Furthermore, we offer a comprehensive review of current optical endoscopic techniques which could potentially be suitable for in vivo ligament strain measurement, along with the most suitable optical measurement techniques. The most promising options are rated based on the defined explicit and implicit requirements. Three methods were identified as promising candidates for a precise optical measurement of the alteration of a ligaments strain: confocal chromatic imaging, shearography, and digital image correlation.

Concomitant Injuries Associated With ACL Rupture in Elite Professional Alpine Ski Racers and Soccer Players: A Comparative Study With Propensity Score Matching Analysis

Background

For elite professional soccer players and alpine skiers, injuries associated with anterior cruciate ligament (ACL) rupture, such as meniscal, cartilage, or collateral ligament lesions, could result in a delayed return to sport compared with isolated ACL injury.

Purpose/Hypothesis

The purpose of the study was to provide a detailed description of associated injuries at the time of primary ACL reconstruction in elite soccer players and alpine skiers. It was hypothesized that soccer players and skiers would present different typical injury patterns due to different injury mechanisms.

Study Design

Cohort study; Level of evidence, 3.

Methods

Surgical reports and arthroscopic images of elite professional soccer players and alpine skiers who underwent primary ACL reconstruction at a single institution between January 2010 and June 2022 were analyzed retrospectively. The presence and location of multiligamentous injury, meniscal tears, and chondral lesions were compared between the athlete groups. A propensity score matching analysis with 1:1 ratio was performed between skiers and soccer players to limit the effect of selection bias.

Results

Included were ACL reconstruction data representative of 37 soccer players and 44 alpine skiers. Meniscal pathology was found in 32 (86%) soccer players and 30 (68%) skiers. Chondral injuries were reported in 11 (30%) soccer players and 15 (34%) skiers. Results of the propensity score matching analysis in 15 pairs of soccer players and skiers indicated that soccer players had a significantly higher rate of medial meniscal injuries (73% vs 27%; P = .03) and lateral posterior root tears (33% vs 0%; P = .04) compared with skiers.

Conclusion

A higher prevalence of combined chondral and meniscal injuries versus isolated ACL injuries was observed in both groups of athletes. Professional soccer players were characterized by higher prevalence of medial meniscal tears and lateral posterior root lesions compared with professional alpine skiers.

The Targeted Deletion of Genes Responsible for Expression of the Mth60 Fimbriae Leads to Loss of Cell-Cell Connections in Methanothermobacter thermautotrophicus ΔH

This study is a continuation by the Environmental Biotechnology Group of the University of Tübingen in memoriam to Reinhard Wirth, who initiated the work on Mth60 fimbriae at the University of Regensburg. Growth in biofilms or biofilm-like structures is the prevailing lifestyle for most microbes in nature. The first crucial step to initiate biofilms is the adherence of microbes to biotic and abiotic surfaces. Therefore, it is crucial to elucidate the initial step of biofilm formation, which is generally established through cell-surface structures (i.e., cell appendages), such as fimbriae or pili, that adhere to biotic and abiotic surfaces. The Mth60 fimbriae of Methanothermobacter thermautotrophicus ΔH are one of only a few known archaeal cell appendages that do not assemble via the type IV pili assembly mechanism. Here, we report the constitutive expression of Mth60 fimbria-encoding genes from a shuttle-vector construct and the deletion of the Mth60 fimbria-encoding genes from the genomic DNA of M. thermautotrophicus ΔH. For this, we expanded our system for genetic modification of M. thermautotrophicus ΔH using an allelic-exchange method. While overexpression of the respective genes increased the number of Mth60 fimbriae, deletion of the Mth60 fimbria-encoding genes led to a loss of Mth60 fimbriae in planktonic cells of M. thermautotrophicus ΔH compared to the wild-type strain. This, either increased or decreased, number of Mth60 fimbriae correlated with a significant increase or decrease of biotic cell-cell connections in the respective M. thermautotrophicus ΔH strains compared to the wild-type strain. IMPORTANCE Methanothermobacter spp. have been studied for the biochemistry of hydrogenotrophic methanogenesis for many years. However, a detailed investigation of certain aspects, such as regulatory processes, was impossible due to the lack of genetic tools. Here, we amend our genetic toolbox for M. thermautotrophicus ΔH with an allelic exchange method. We report the deletion of genes that encode the Mth60 fimbriae. Our findings provide the first genetic evidence of whether the expression of these genes underlies regulation and reveal a role of the Mth60 fimbriae in the formation of cell-cell connections of M. thermautotrophicus ΔH.

Graft choices for paediatric anterior cruciate ligament reconstruction: State of the art

The paediatric population is at particularly high risk for anterior cruciate ligament (ACL) injuries due to high rates of sports participation. Other risk factors for ACL injuries in children include but are not limited to being female, generalised ligamentous laxity, a high body mass index (BMI), and poor neuromuscular control. ACL reconstruction (ACLR) is commonly done to treat ACL injuries and allow for return to sports and daily activities. ACL repair is another option with ongoing techniques being developed. The high rates of graft failure in children reported in recent publications on ACL repair are very concerning. Special consideration must be taken in ACLR in the skeletally immature patient due to the risk of growth-related complications, such as limb deformity or growth arrest, that can arise from drilling across or disrupting the physis. Graft choices for paediatric ACLR include iliotibial band (ITB) over the top and over the front, hamstring autograft, bone patellar tendon bone (BTB) autograft, quadriceps tendon autograft, and allograft. Factors for each graft choice to consider include graft size, graft failure rates, donor site morbidity, requirement for bony tunnels, the post-op rehabilitation process, and return to sport outcomes. Each graft has its benefits and disadvantages for the individual patient, depending on age, skeletal maturity, and goals for recovery. Lateral extra-articular tenodesis (LET) is another option to consider with paediatric ACLR because LET has been shown to decrease the re-rupture rate in adult ACLR. After surgery, patient follow-up until at least the growth plates are closed is important. This article aims to provide an overview and comparison of the various graft types to aid in the graft choice decision making process for paediatric ACLR.

Revision ACL reconstruction using quadriceps, hamstring and patellar tendon autografts leads to similar functional outcomes but hamstring graft has a higher tendency of graft failure

PURPOSE

The purpose of this study was to evaluate the differences in the patient-reported functional outcomes, and graft failure in revision ACL reconstruction using quadriceps tendon (QT), Hamstring tendon (HT) and bone-patellar tendon-bone (BPTB) autografts.

METHODS

Between 2010 and 2020, 97 patients who underwent revision ACL reconstruction (40 patients received a QT, 26 an HT and 31 a BPTB graft) met the inclusion criteria. Pre-injury and at 2-year postoperatively patients were evaluated for patient-reported functional outcomes; Lysholm knee score, Tegner activity level and VAS (visual analogue scale) for pain; and graft failure. Patient-reported outcomes and graft failure were compared between the QT, HT and BPTB groups. The patients with graft failure were not included for outcome analysis at 2-years of follow-up.

RESULTS

All three revision groups with QT, HT and BPTB autograft did not differ significantly in terms of age, sex, time from injury to surgery, concomitant injuries and single-stage or double-stage procedures (n.s.). No significant difference was found in the pre-injury patient-reported outcome; Lysholm knee score, Tegner activity and VAS for pain (n.s.) between the three groups. At the 2-year follow-up functional outcomes improved in all three groups and all the patients returned to pre-injury activity level; however, no significant difference was found in functional outcomes at the 2-year follow-up between the three groups (n.s.). Graft failure occurred in 4 (10%), 5 (19%) and 3 (10%) patients of QT, HT and BPTB groups, respectively. However, the rate of failure did not differ significantly between groups.

CONCLUSION

All three autografts (QT, HT and BPTB) demonstrated satisfactory patient-reported outcomes in revision ACL reconstruction. Compared with QT and BPTB grafts, HT graft showed a higher tendency for failure rates. With the increasing incidence of revision ACL reconstruction, surgeons should be aware of all the available graft options. The findings of this study will assist the surgeons in the graft selection for revision ACL reconstruction.

LEVEL OF EVIDENCE

Level III.

Influence of contrast agent on artificial intelligence-based CT low attenuation volume percentage measurement

BACKGROUND

Low attenuation volume percentage (LAV%) has been identified as a quantitative imaging biomarker for emphysema with good correlation with spirometry. The influence of intravenous contrast agent on LAV% and its correlation with spirometry is not well known.

PURPOSE

To evaluate the influence of intravenous contrast agent on artificial intelligence (AI)-based LAV% in correlation with spirometric Tiffeneau-Pinelli Index (TI).

MATERIAL AND METHODS

In a retrospective study, two groups of 47 patients (mean age 68.04 ± 12.64 and 67.89 ± 11.54 years) with either non-enhanced chest computed tomography (CT) or contrast-enhanced CT were compared. Using an AI-based software, LAV% was quantified using a threshold <-950 HU. TI was calculated from spirometry and pathologic airway obstruction was considered with a TI <70. The effect of contrast agent on LAV% and the relationship between TI and LAV% was analyzed. Correlation coefficients between TI and LAV% were compared for both groups.

RESULTS

Patients with non-enhanced CT had a mean LAV% of 9.07 ± 7.53. Of them, 22 patients had a TI <70% and 25 patients a TI ≥70%. Patients with contrast-enhanced CT had a mean LAV% of 6.54 ± 4.62. Of them, 20 patients had a TI <70% and 27 patients had a TI ≥70%. Contrast agent did not show a major effect on LAV% (P = 0.099) and the relationship between TI and LAV% (P = 0.88). In both groups, a significant correlation between TI and LAV% was found (ρ = -0.317 for non-enhanced CT; ρ = -0.514 for contrast-enhanced CT). Difference between correlation coefficients was insignificant.

CONCLUSION

Our findings suggest that contrast agent does not influence LAV% nor its correlation with TI.

No difference in patient reported outcomes, laxity, and failure rate after revision ACL reconstruction with quadriceps tendon compared to hamstring tendon graft: a systematic review and meta-analysis

PURPOSE

The purpose of this study was to synthesize and quantitatively assess the outcomes of ACL Revision using a quadriceps tendon (QT) graft and to compare them with those of ACL Revisions performed with hamstring tendons (HT) graft.

METHODS

A comprehensive search based on the PRISMA protocol was performed across PubMed, Scopus, Embase, and Cochrane Library from inception until February 2022. Clinical studies reporting the outcomes of ACL Revision with QT autograft were included. Subjective and Objective IKDC, Tegner activity level, Lysholm knee score, KOOS score, VAS for pain, knee laxity (KT-1000/2000 arthrometer, Lachman test, and pivot-shift test), and graft failure were assessed. A systematic review and meta-analysis were performed and a quality assessment of the included studies was carried out with the MINORS score.

RESULTS

Seven studies met the selection criteria and were included in the systematic review for the qualitative synthesis of data. A pooled mean of all the variables was provided for the 7 studies, while 3 studies included a control group of ACL Revision with HT and were included in a meta-analysis. A total of 420 participants with a mean age of 28.9 ± 10.5 years and a mean postoperative follow-up of 39.3 ± 16.4 months were assessed. Of these, 277 patients underwent ACL Revision with QT and 143 patients underwent ACL Revision with HT. In the QT group, average graft failure was 9.8% compared to 17.4% in the HT group. KOOS Sport and pivot-shift test showed better postoperative outcomes in QT than HT, although it was not statistically significant (p = 0.052).

CONCLUSION

The QT autograft was associated with an improved trend of rotatory laxity, PROMs and failure rate compared to HT autograft after revision ACL reconstruction. The QT autograft for revision ACL reconstruction is supported by the current literature. It is a viable graft that should be considered for both primary and revision ACL reconstruction.

LEVEL OF EVIDENCE

Level IV.

Return to Play and Pattern of Injury After ACL Rupture in a Consecutive Series of Elite UEFA Soccer Players

Background

Anterior cruciate ligament rupture represents a career-threatening injury for professional soccer players.

Purpose

To analyze the pattern of injury, return to play (RTP), and performance of a consecutive series of elite professional soccer players after anterior cruciate ligament reconstruction (ACLR).

Study Design

Case series; Level of evidence, 4.

Methods

We evaluated the medical records of 40 consecutive elite soccer players who underwent ACLR by a single surgeon between September 2018 and May 2022. Patient age, height, weight, body mass index, position, injury history, affected side, RTP time, minutes played per season (MPS), and MPS as a percentage of playable minutes before and after ACLR were retrieved from medical records and from publicly available media-based platforms.

Results

Included were 27 male patients (mean ± SD age at surgery, 23.2 ± 4.3 years; range, 18-34 years). The injury occurred during matches in 24 players (88.9%), with a noncontact mechanism in 22 (91.7%). Meniscal pathology was found in 21 patients (77.8%). Lateral meniscectomy and meniscal repair were performed in 2 (7.4%) and 14 (51.9%) patients, respectively, and medial meniscectomy and meniscal repair were performed in 3 (11.1%) and 13 (48.1%) patients, respectively. A total of 17 players (63.0%) underwent ACLR with bone-patellar tendon-bone autograft and 10 (37.0%) with soft tissue quadriceps tendon. Lateral extra-articular tenodesis was added in 5 patients (18.5%). The overall RTP rate was 92.6% (25 of 27). Two athletes moved to a lower league after surgery. The mean MPS% during the last preinjury season was 56.69% ± 21.71%; this decreased significantly to 29.18% ± 20.6% (P < .001) in the first postoperative season and then increased to 57.76% ± 22.89% and 55.89% ± 25.8% in the second and third postoperative seasons. Two (7.4%) reruptures and 2 (7.4%) failed meniscal repairs were reported.

Conclusion

ACLR in elite UEFA soccer players was associated with a 92.6% rate of RTP and 7.4% rate of reinjury within 6 months after primary surgery. Moreover, 7.4% of soccer players moved to a lower league during the first season after surgery. Age, graft selection, concomitant treatments, and lateral extra-articular tenodesis were not significantly associated with prolonged RTP.

[Importance and application of injury prevention in Austrian football - a survey among 687 coaches]

BACKGROUND

Soccer is one of the most popular sports in the world but associated with a high risk of injury. For this reason, the study of the etiology of injuries is of great interest and numerous prevention programs have been developed in recent years. Since these prevention programs must be embedded into training routine, trainers are primarily responsible for their implementation. The present study aimed to survey Austrian soccer coaches engaged in professional, amateur or youth teams with respect to their opinions on injuries as well as the application of respective prevention programs.

METHODS

An online questionnaire was developed and sent to all coaches registered in the Austrian Football Association.In addition to personal data, the trainers' attitudes to the subject of injury prevention were also asked. It was also asked which preventive measures the trainers consider important and which they also use in their training and to what extent.

RESULTS

A total of 687 trainers took part in the survey. 2,3%, 37,5% and 43,6% of trainers were engaged in professional, amateur and youth clubs, respectively. The rest gave no information. The majority of respondents (56%) considered injuries a major concern in soccer. Inadequate fitness (75,7%) as well as insufficient preparation (60,7%) and poor regeneration (59,2%) were seen as the greatest risk factors for injuries. Appropriate warm-up (66,8%), regeneration (59,4%) and core stabilization training (58,2%) were considered the most effective preventative measures. More than 50% of the participants were not familiar with any of the most widely applied injury prevention programs, and only 15.4% actually implemented those programs in their training.The substantial interest in injury prevention notwithstanding, the respective standard of knowledge amongst Austrian coaches is poor. In light of the high prevalence of injuries, it is most important to inform trainers about injury prevention programs and possibilities to implement them in training practice.

Total knee arthroplasty improves sports activity and the patient-reported functional outcome at mid-term follow-up

PURPOSE

The purpose of this study was to assess (1) sports participation and preference for the type of sports activity after TKA, (2) mid-term functional outcome and activity level, (3) correlation of different age groups with activity level and functional outcomes, and (4) mid-term survivorship of the prosthesis.

METHODS

A retrospective review of prospectively collected data was performed. 182 patients were included who underwent primary TKA between January 2010 and December 2016. Inclusion criteria were symptomatic knee osteoarthritis, age 50-90 years, and with a minimum of 5-year follow-up after TKA. Patients with rheumatoid arthritis and revision TKA were excluded. Sports participation and sports preference, Oxford Knee Score (OKS), Tegner Activity Level, and Visual Analogue Scale (VAS) for pain were recorded pre- and postoperatively at 6 months, 1 year, 2 years, and 5 years. The patient cohort was subdivided according to age groups; activity levels, patient-reported outcomes, and improvement in knee pain were correlated with these age groups. Kaplan-Meier curves were used to investigate survivorship at a minimum of 5 years.

RESULTS

The mean age of the cohort was 75.6 ± 7.2 years (range 52-89). Significant improvement was noted in sports participation (p < 0.003). After TKA, there was no change in the preference for sports and none of the patients had to discontinue their sporting activity. OKS improved significantly at all follow-up time points compared to the preoperative score (p < .0001). Patients' sports and physical activity improved significantly at 1 year compared to the preoperative activity level (p < 0.001). Although the Tegner activity level improved over time, this improvement was not significant (NS), while it was significantly higher in males than in females (p < 0.004). Significant improvement was found in the VAS for pain at all follow-up time points compared to the preoperative score (p < .0001). Survivorship was found to be 100% at a 5-year follow-up.

CONCLUSION

After TKA, patients can be able to return to sporting activity or even perform better than before surgery. Maximum improvement was noted in the first post-operative year. The male and younger groups perform better than the female and older groups. Sports and physical activity do not negatively impact survivorship of the knee prosthesis at mid-term follow-up and all patients are encouraged to take up sports participation after their TKA.

LEVEL OF EVIDENCE

Level 3.

Complications and downsides of the robotic total knee arthroplasty: a systematic review

PURPOSE

The purpose of this systematic review is to describe the complications and downsides of robotic systems in total knee arthroplasty (TKA).

METHODS

A comprehensive search according to the PRISMA guidelines was performed across PubMed, MEDLINE, Cochrane Central Register of Controlled Trials, Scopus, and Google Scholar from inception until December 2021. All articles of any study design directly reporting on complications and downsides of the robotic system in TKA were considered for inclusion. Risk of bias assessment was performed for all included studies using the Cochrane risk of bias and MINORS score.

RESULTS

A total of 21 studies were included, consisting of 4 randomized controlled trials, 7 prospective studies and 10 retrospective studies. Complications of the robotic system were pin-hole fracture, pin-related infection, iatrogenic soft tissue and bony injury, and excessive blood loss. While, downsides were longer operative duration, higher intraoperative cost, learning curve and aborting a robotic TKA due to different reasons. Iatrogenic injuries were more common in the active robotic system and abortion of the robotic TKA was reported only with active robotic TKA.

CONCLUSION

Robotic TKA is associated with certain advantages and disadvantages. Therefore, surgeons need to be familiar with the system to use it effectively. Widespread adoption of the robotic system should always be evidence-based.

LEVEL OF EVIDENCE

IV.

Quadriceps tendon autograft for anterior cruciate ligament reconstruction: state of the art

The ideal graft for anterior cruciate ligament reconstruction (ACLR) continues to be debated. Although first described in 1984, use of the quadriceps tendon (QT) autograft has only recently gained popularity. The biomechanical properties of the QT autograft are favourable compared to bone-patellar tendon-bone (BPTB) and doubled hamstring (HS) grafts with a higher load to failure and a modulus of elasticity that more closely approximates the native anterior cruciate ligament (ACL). The QT graft can be harvested with or without a bone plug, as either a full thickness or a partial thickness graft, and even through minimally invasive techniques. The surgeon must be aware of potential harvest risks including patellar fracture or a graft that is of insufficient length. Numerous short-term studies have shown comparable results when compared to BPTB or hamstring HS autografts with similar graft failure rates, patient-reported outcomes. A major advantage of QT ACLR is reduced donor site morbidity compared to BPTB. However, some persistent quadriceps weakness after QT ACLR has also been reported. The current literature shows that use of the QT autograft for ACLR provides equivalent clinical results compared to other autografts with less donor site morbidity. However, future studies with longer follow-up and higher level of evidence are needed to identify specific populations where the QT may have additional advantage.

Quadriceps tendon autograft for primary anterior cruciate ligament reconstruction show comparable clinical, functional, and patient-reported outcome measures, but lower donor-site morbidity compared with hamstring tendon autograft: A matched-pairs study with a mean follow-up of 6.5 ​years

OBJECTIVES

To compare clinical and functional outcomes of patients after primary anterior cruciate ligament reconstruction (ACLR) using quadriceps tendon- (QT-A) and hamstring tendon (HT-A) autograft with a minimum follow-up (FU) of 5 years.

METHODS

Between 2010 and 2014, all patients undergoing ACLR were recorded in a prospectively administered database. All patients with primary, isolated QT-A ACLR and without any concomitant injuries or high grade of osteoarthritis were extracted from the database and matched to patients treated with HT-A. Re-rupture rates, anterior-posterior (ap) knee laxity, single-leg hop test (SLHT) performance, distal thigh circumference (DTC) and patient-reported outcome measures (PROMs) were recorded. Between group comparisons were performed using chi-square-, independent-samples T- or Mann-Whitney-U tests.

RESULTS

45 QT-A patients were matched to 45 HT-A patients (n ​= ​90). The mean FU was 78.9 ​± ​13.6 months. 18 patients (20.0%/QT-A: N ​= ​8, 17.8%; HT-A: n ​= ​10, 22.2%; p ​= ​.60) sustained a graft rupture and 17 subjects (18.9%/QT-A: n ​= ​9, 20.0%; HT-A: n ​= ​8, 17.8%; p ​= ​.79) suffered a contralateral ACL injury. In high active patients (Tegner activity level ≥ 7) rerupture rates increased to 37.5% (HT-A) and 22.2% (QT-A; p ​= ​.32), respectively. Patients with graft failure did not differ between both groups in terms of mean age at surgery (QT-A: 26.5 ​± ​11.6 years, HT-A: 23.3 ​± ​9.5 years, p ​= ​.63) or graft thickness (mean graft square area: QT-A: 43.6 ​± ​4.7 mm², HT-A: 48.1 ​± ​7.9 mm², p ​= ​.27). No statistical between-group differences were found in ap knee laxity side-to-side (SSD) measurements (QT-A: 1.9 ​± ​1.2 ​mm, HT-A: 2.1 ​± ​1.5 ​mm; p ​= ​.60), subjective IKDC- (QT-A: 93.8 ​± ​6.8, HT-A: 91.2 ​± ​7.8, p ​= ​.17), Lysholm- (QT-A 91.9 ​± ​7.2, HT-A: 91.5 ​± ​9.7, p ​= ​.75) or any of the five subscales of the KOOS score (all p ​> ​.05). Furthermore, Tegner activity level (QT-A: 6(1.5), HT-A: 6(2), p ​= ​.62), VAS for pain (QT-A: 0.5 ​± ​0.9, HT-A: 0.6 ​± ​1.0, p ​= ​.64), Shelbourne-Trumper score (QT-A: 96.5 ​± ​5.6, HT-A: 95.2 ​± ​8.2, p ​= ​.50), Patient and Observer Scar -Assessment scale (POSAS) (QT-A: 9.4 ​± ​3.2, HT-A: 10.7 ​± ​4.9, p ​= ​.24), SSD-DTC (QT-A: 0.5 ​± ​0.5, HT.- A: 0.5 ​± ​0.6, p ​= ​.97), return to sports rates (QT-A: 82.1%, HT-A: 86.7%) and SLHT (QT -A: 95.9 ​± ​3.8%, HT-A: 93.7 ​± ​7.0%) did not differ between groups. Donor-site morbidity (HT-A n ​= ​14, 46.7%; QT-A n ​= ​3, 11.5%; p ​= ​.008) was statistically significantly lower in the QT-A group. Five patients (11.1%) of the HT-group and three patients (6.7%) in the QT-group required revision surgery (p ​= ​.29).

CONCLUSION

Patient-reported outcome measures, knee laxity, functional testing results and re-rupture rates are similar between patients treated with QT- and HT- autografts. However, patients with QT-autograft have a smaller tibial postoperative scar length and lower postoperative donor-site morbidity. There is a tendency towards higher graft rupture rates in highly active patients treated with HT autograft.

LEVEL OF EVIDENCE

II.

No difference in sports participation and patient-reported functional outcomes between total knee arthroplasty and unicompartmental knee arthroplasty at minimum 2-year follow-up in a matched control study

PURPOSE

The purpose of this study was to compare (1) sports participation and type of sports activity between TKA and UKA patients; (2) functional outcome and activity level between TKA and UKA; and (3) survivorship of the prosthesis in both the groups.

METHODS

Prospectively collected data were obtained from an arthroplasty database to identify patients who underwent primary TKA and UKA. Both the cohorts of TKA and UKA were matched, controlling for age, sex, BMI and preoperative patient-reported outcomes, which include Oxford Knee Score (OKS), Tegner activity level, and visual analog scale (VAS) for pain score. After matching the two groups, 287 TKA and 69 UKA cases were available to be included in the study. Patients were evaluated pre- and postoperatively at 2 years for sports participation and sports preference, patient-reported outcomes, activity levels, and improvement in knee pain.

RESULTS

The mean age of the TKA and UKA groups were 75.7 ± 8.1 and 74.2 ± 8.8, respectively. There was no significant difference between the two groups concerning the demographic variables. Significant improvement was noted in the weekly sports participation at the final follow-up compared to preoperative sports participation in both the TKA and UKA groups (p < 0.05). All patients were able to return to their desired sporting activity. No significant difference was noted between the two groups in sports participation preoperatively and postoperatively (p > 0.05). OKS, Tegner activity level and VAS for pain demonstrated a significant improvement from preoperative to 2 years postoperatively (p < 0.05). However, preoperative and postoperative patient-reported outcomes did not differ significantly between the TKA and UKA groups (p > 0.05). No case of revision surgery was found at a 2-year follow-up in both groups.

CONCLUSION

Traditionally, in isolated medial compartment osteoarthritis, UKA has been considered to be the procedure with better functional outcomes, but the current study demonstrates that when confounding factors are controlled, both TKA and UKA are effective, and offer similar functional outcomes and result in similar improvement in sports participation. These findings will be helpful to counsel the patients to choose the best suitable operative procedure between UKA and TKA.

LEVEL OF EVIDENCE

Level 3.

Instabilität des Kniegelenks – medial oder anteromedial?

Hintergrund

Verletzungen des medialen Bandkomplexes gehören zu den häufigsten Knieverletzungen. Sie heilen zwar meist mit konservativer Therapie problemlos aus, persistierende Instabilitäten erhöhen aber die Belastung der Kreuzbänder und benötigen speziell bei deren Beteiligung eine adäquate Therapie.

Anatomie und Biomechanik

Der mediale Seitenbandkomplex besteht im Wesentlichen aus dem oberflächlichen Seitenband (sMCL), welches der primäre Stabilisator gegen Valgus ist, dem tiefen Seitenband (dMCL) mit dessen schräg verlaufendem ventralem Anteil (AML), die nur sekundäre Stabilisatoren gegen Valgus darstellen, aber primär gegen Außenrotation stabilisieren, und dem hinteren Schrägband (POL), das in vollständiger Streckung gegen Valgus sowie gegen Innenrotation stabilisiert.

Therapie

Chronische Instabilitäten bzw. höhergradige Verletzungen mit Dislokation der Bandstümpfe oder multiligamentäre Verletzungen bedürfen einer operativen Versorgung. Im Akutstadium zeigen Avulsionsverletzungen bei anatomischer Refixation gutes Heilungspotenzial, während bei intraligamentären Verletzungen zusätzlich zur Naht der Bandanteile eine Augmentation mit Sehnenmaterial empfohlen wird. Bei chronischen Instabilitäten ist die Differenzierung des Instabilitätsmusters ausschlaggebend für die Wahl der Rekonstruktionstechnik (reine sMCL-Rekonstruktion oder kombinierte Rekonstruktion von sMCL und AML). In beiden Fällen kommt die hier beschriebene Technik mit flachem Transplantat der Anatomie näher als bei konventionellen Verfahren.

Diskussion

Rekonstruktionstechniken unter Verwendung flacher Sehnentransplantate, die alle betroffenen Bandanteile adressieren, haben sich biomechanisch als sehr effektiv erwiesen, komplexe mediale Instabilitäten suffizient zu behandeln. Ob diese auch klinisch überlegen sind, werden zukünftige klinische Studien zeigen müssen.

Medial Collateral Ligament Reconstruction: A Gracilis Tenodesis for Anteromedial Knee Instability

The main principle of the present medial collateral ligament reconstruction technique is to address anteromedial knee instability. Therefore, we describe a gracilis tenodesis with 2 functional bundles to reconstruct the deep and superficial medial collateral ligament. The proposed technique may be performed as an isolated or combined procedure with anterior cruciate ligament reconstruction. Valgus instability in extension is a contraindication.

The Control of Anteromedial Rotatory Instability Is Improved With Combined Flat sMCL and Anteromedial Reconstruction

BACKGROUND

Both the superficial medial collateral ligament (sMCL) and the deep MCL (dMCL) contribute to the restraint of anteromedial (AM) rotatory instability (AMRI). Previous studies have not investigated how MCL reconstructions control AMRI.

PURPOSE/HYPOTHESIS

The purpose was to establish the optimal medial reconstruction for restoring normal knee kinematics in an sMCL- and dMCL-deficient knee. It was hypothesized that AMRI would be better controlled with the addition of an anatomically shaped (flat) sMCL reconstruction and with the addition of an AM reconstruction replicating the function of the dMCL.

STUDY DESIGN

Controlled laboratory study.

METHODS

A 6 degrees of freedom robotic system equipped with a force-torque sensor was used to test 8 unpaired knees in the intact, sMCL/dMCL sectioned, and reconstructed states. Four different reconstructions were assessed. The sMCL was reconstructed with either a single-bundle (SB) or a flattened hamstring graft aimed at better replicating the appearance of the native ligament. These reconstructions were tested with and without an additional AM reconstruction. Simulated laxity tests were performed at 0°, 30°, 60°, and 90° of flexion: 10 N·m valgus rotation, 5 N·m internal and external rotation (ER), and an AM drawer test (combined 134-N anterior tibial drawer in 5 N·m ER). The primary outcome measures of this force-controlled setup were anterior tibial translation (ATT; in mm) and axial tibial rotation (in degrees).

RESULTS

Sectioning the sMCL/dMCL increased valgus rotation, ER, and ATT with the simulated AM draw test at all flexion angles. SB sMCL reconstruction was unable to restore ATT, valgus rotation, and ER at 30°, 60°, and 90° of flexion to the intact state (P < .05). Flat MCL reconstruction restored valgus rotation at all flexion angles to the intact state (P > .05). ER was restored at all angles except at 90°, but ATT laxity in response to the AM drawer persisted. Addition of an AM reconstruction improved control of ATT relative to the intact state at all flexion angles (P > .05). Combined flat MCL and AM reconstruction restored knee kinematics closest to the intact state.

CONCLUSION

In a cadaveric model, AMRI resulting from an injured sMCL and dMCL complex could not be restored by an isolated SB sMCL reconstruction. A flat MCL reconstruction or an additional AM procedure, however, better restored medial knee stability.

CLINICAL RELEVANCE

In patients evaluated with a combined valgus and AM rotatory instability, a flat sMCL and an additional AM reconstruction may be superior to an isolated SB sMCL reconstruction.

Longitudinal observational study on health literacy and clinical outcomes in older adults with total knee arthroplasty in the context of inpatient and outpatient rehabilitation

Purpose

To assess health literacy (HL) of patients with total knee arthroplasty (TKA) and evaluate its impact on patient reported outcome measures (PROMs) as well as investigating outcome differences in inpatient and outpatient rehabilitation.

Methods

In this study, HL and PROMs of older patients were assessed preoperatively (T0) and after 3 (T1), 6 (T2), and 12 (T3) months. HL was assessed with the short form of the European HL Questionnaire; pain scores, functional restrictions, and activity levels with standardized PROMs.

Results

Limited HL was observed in 70.6% of patients at T0. HL improved from baseline to follow-ups (p < 0.001). There was no impact of HL on PROMs. Pain scores were higher in patients undergoing outpatient rehabilitation (p = 0.022). No differences were found between the rehabilitation settings for the other outcomes.

Conclusion

The study shows that limited HL is prevalent in patients with scheduled TKA. Rehabilitation seems to have a positive effect on increasing HL.

MCL Reconstruction Using a Flat Tendon Graft for Anteromedial and Posteromedial Instability

The main principles of the present medial collateral ligament (MCL) reconstruction techniques are (1) to approximate the natural anatomy and (2) to restore the main passive restraining structures in anteromedial and posteromedial knee instability. Therefore, we describe a technique using a flat tendon graft instead of tubular grafts with point-to-point bone fixation. Moreover, we address the deep MCL, a relevant restraint to anteromedial instability.

An Interdomain Conjugation Protocol for Plasmid-DNA Transfer into Methanothermobacter thermautotrophicus ΔH

Methanogenic archaea of the order Methanobacteriales are widespread in anaerobic environments and play pivotal roles in microbial communities. The family of Methanobacteriaceae encompasses mesophilic and thermophilic hydrogenotrophic species. Mesophilic species are found in various natural and anthropogenic environments (e.g., are associated with the microbiome in animals and humans). Thermophilic species can be found in thermally active bogs and warm sulfuric springs, but also in anthropogenic environments, such as wastewater treatment plants and anaerobic digesters. Recently, genetic tools for Methanothermobacter thermautotrophicus ΔH, as the first representative of this order of methanogenic archaea, were successfully implemented. This protocol describes the methods for interdomain conjugational DNA transfer from Escherichia coli to M. thermautotrophicus ΔH with shuttle-vector plasmid DNA, which allows the genetic manipulation of this microbe, and provides a basis for the development of further genetic methods for this and potentially other representatives of Methanobacteriales.

Conservative treatment of iliotibial band syndrome in runners: Are we targeting the right goals?

OBJECTIVE

Iliotibial band syndrome (ITBS) is presumably caused by excessive tension in the iliotibial band (ITB) leading to compression and inflammation of tissues lying beneath it. Usually managed conservatively, there is a lack of scientific evidence supporting the treatment recommendations, and high symptom recurrence rates cast doubt on their causal effectiveness. This review discusses the influence of common physiotherapeutic measures on risk factors contributing to tissue compression beneath the ITB.

METHODS

The potential pathogenic factors are presented on the basis of a simple biomechanical model showing the forces acting on the lateral aspect of the knee. Existent literature on the most commonly prescribed physiotherapeutic interventions is critically discussed against the background of this model. Practical recommendations for the optimization of physiotherapy are derived.

RESULTS

According to biomechanical considerations, ITBS may be promoted by anatomical predisposition, joint malalignments, aberrant activation of inserting muscles as well as excessive ITB stiffness. Hip abductor strengthening may correct excessive hip adduction but also increase ITB strain. Intermittent stretching interventions are unlikely to change the ITB's length or mechanical properties. Running retraining is a promising yet understudied intervention.

CONCLUSIONS

High-quality research directly testing different physiotherapeutic treatment approaches in randomized controlled trials is needed.

Developing a Technique for the Imaging-Based Measurement of ACL Elongation: A Proof of Principle

Towards the goal of obtaining non-invasive biomarkers reflecting the anterior cruciate ligament’s (ACL) loading capacity, this project aimed to develop a magnetic resonance imaging (MRI)-based method facilitating the measurement of ACL elongations during the execution of knee stress tests. An MRI-compatible, computer-controlled, and pneumatically driven knee loading device was designed to perform Lachman-like tests and induce ACL strain. A human cadaveric leg was used for test purposes. During the execution of the stress tests, a triggered real-time cine MRI sequence with a temporal resolution of 10 Hz was acquired in a parasagittal plane to capture the resultant ACL elongations. To test the accuracy of these measurements, the results were compared to in situ data of ACL elongation that were acquired by measuring the length changes of a surgical wire directly sutured to the ACL’s anteromedial bundle. The MRI-based ACL elongations ranged between 0.7 and 1.7 mm and agreed very well with in situ data (root mean square errors, RMSEs ≤ 0.25 mm), although peak elongation rates were underestimated by the MRI (RMSEs 0.19–0.36 mm/s). The high accuracy of elongation measurements underlines the potential of the technique to yield an imaging-based biomarker of the ACL’s loading capacity.

Preliminary experience of an international orthopaedic registry: the ESSKA Paediatric Anterior Cruciate Ligament Initiative (PAMI) registry

Paediatric and adolescent ACL injuries are an emerging health burden, increasing at a higher rate than in adults. They compromise quality of life, affect knee structure and function, lead to the early development of osteoarthritis and are a serious economic burden due to shortened professional careers and subsequent surgeries. Up to 35% of children and adolescents will experience a second ACL injury and this population particularly at high risk of secondary intraarticular soft tissue degeneration and growth abnormalities. However, there is still a lack of high-quality outcome studies on this specific population and many knowledge gaps persist in the current treatment guidelines. It is currently unknown whether ACL reconstruction in this young population decreases the risk of irreversible secondary intraarticular soft tissue degeneration. Furthermore, it is not known whether return to high or elite level sports after paediatric ACL injury or reconstruction should be recommended. The relatively low number of paediatric ACL injuries seen in each hospital makes it necessary to conduct international multi-centre studies to collect robust data to provide evidence-based guidelines for the treatment of these injuries. The Paediatric Anterior Cruciate Ligament Initiative (PAMI) was thus started by the European Society of Sports Traumatology, Knee Surgery & Arthroscopy and opened for patient inclusion in 2018. This comprehensive overview of the first 2 years of the PAMI registry shows that the project is now well consolidated and accepted by the European orthopaedic community. Future challenges include ensuring additional external funding to ascertain long term sustainability and continuous dissemination of the knowledge acquired in scientific journals.

Anatomic and Biomechanical Properties of Flat Medial Patellofemoral Ligament Reconstruction Using an Adductor Magnus Tendon Graft: A Human Cadaveric Study

BACKGROUND

In contrast to the majority of existing techniques for reconstruction of the medial patellofemoral ligament (MPFL), the technique described in this article uses the adductor magnus muscle tendon to gain a flat, broad graft, leaving its distal femoral insertion intact, and does not require drilling within or near the femoral physis. It also allows for soft tissue patellar fixation and could facilitate anatomic MPFL reconstruction in skeletally immature patients.

PURPOSE

To evaluate the anatomic and structural properties of the native MPFL and the adductor tendon (AT), followed by biomechanical evaluation of the proposed reconstruction.

STUDY DESIGN

Descriptive laboratory study.

METHODS

The morphological and topographical features of the AT and MPFL were evaluated in 12 fresh-frozen cadaveric knees. The distance between the distal insertion of the AT on the adductor tubercle and the adductor hiatus, as well as the desired length of the graft, was measured to evaluate this graft's application potential. Load-to-failure tests were performed to determine the biomechanical properties of the proposed reconstruction construct. The construct was placed in a uniaxial testing machine and cyclically loaded 500 times between 5 and 50 N, followed by load to failure, to measure the maximum elongation, stiffness, and maximum load.

RESULTS

The mean ± SD length of the AT was 12.6 ± 1.5 cm, and the mean distance between the insertion on the adductor tubercle and adductor hiatus was 10.8 ± 1.3 cm, exceeding the mean desired length of the graft (7.5 ± 0.5 cm) by 3.3 ± 0.7 cm. The distal insertion of the AT was slightly proximal and posterior to the insertion of the MPFL. The maximum elongation after cyclical loading was 1.9 ± 0.4 mm. Ultimately, the mean stiffness and load to failure were 26.2 ± 7.6 N/mm and 169.7 ± 19.2 N, respectively. The AT graft failed at patellar fixation in 2 of the initially tested specimens and at the femoral insertion in the remaining 10.

CONCLUSION

The described reconstruction using the AT has potential for MPFL reconstruction. The AT graft presents a graft of significant volume, beneficial anatomic topography, and adequate tensile properties in comparison with the native MPFL following the data from previously published studies.

CLINICAL RELEVANCE

Given its advantageous anatomic relationship as an application that avoids femoral drilling and osseous patellar fixation, the AT may be considered a graft for MPFL reconstruction in skeletally immature patients.

Contralateral ACL tears strongly contribute to high rates of secondary ACL injuries in professional ski racers

PURPOSE

To analyse the effects of graft selection, sex, injury complexity and time to return to competition on the odds to suffer secondary ACL injury (either re-rupture or contralateral ACL tear) in professional alpine skiers.

METHODS

The database of a specialised joint surgery clinic was screened for professional alpine skiers who had participated in competitions at the FIS race, European Cup and World Cup level prior to having to undergo a primary ACL reconstruction, and who had returned to the same competitional level at least one year prior to the end of the observation period. The rates of secondary ACL injuries were statistically compared between athletes with hamstring and quadriceps tendon autografts, men and women, simple and complex (involvement of menisci or cartilage) primary ACL injuries, and between early (≤ 300 days after primary reconstruction) and late (> 300 days) returners to competition.

RESULTS

Fourteen out of the 30 athletes included (46.7%) suffered secondary ACL injuries on average 29.4 ± 22.5 months after primary reconstruction. The secondary injuries comprised five re-ruptures (16.7%) and nine contralateral ACL tears (30.0%). The odds to suffer contralateral ACL tears were non-significantly higher in patients with hamstring tendon autografts (OR 5.69, n.s.) and in those whose primary injuries were classified as simple ACL tears (OR 5.31, n.s.). None of the factors assessed was associated with the odds of graft failure.

CONCLUSION

The odds of ACL-injured professional alpine ski racers to suffer secondary ACL tears are nearly 50%, with subsequent contralateral ACL injuries being more common than graft failures. While statistical significance could not be established due to a lack of power, greater odds of contralateral ACL tears were observed in athletes with hamstring tendon grafts as well as those with simple primary ACL injuries. No factors potentially predisposing athletes for graft failure could be identified.

LEVEL OF EVIDENCE

III.

Return to sport after anterior cruciate ligament injury: Panther Symposium ACL Injury Return to Sport Consensus Group

OBJECTIVES

A precise and consistent definition of return to sport (RTS) after anterior cruciate ligament (ACL) injury is lacking, and there is controversy surrounding the process of returning patients to sports and their previous activity level. The aim of the Panther Symposium ACL Injury RTS Consensus Group was to provide a clear definition of RTS after ACL injury and description of the RTS continuum, as well as provide clinical guidance on RTS testing and decision-making.

METHODS

An international, multidisciplinary group of ACL experts convened as part of a consensus meeting. Consensus statements were developed using a modified Delphi method. Literature review was performed to report the supporting evidence.

RESULTS

Key points include that RTS is characterised by achievement of the preinjury level of sport and involves a criteria-based progression from return to participation to RTS, and ultimately return to performance. Purely time-based RTS decision-making should be abandoned. Progression occurs along an RTS continuum with decision-making by a multidisciplinary group that incorporates objective physical examination data and validated and peer-reviewed RTS tests, which should involve functional assessment as well as psychological readiness. Consideration should be given to biological healing, contextual factors and concomitant injuries.

CONCLUSION

The resultant consensus statements and scientific rationale aim to inform the reader of the complex process of RTS after ACL injury that occurs along a dynamic continuum. Research is needed to determine the ideal RTS test battery, the best implementation of psychological readiness testing and methods for the biological assessment of healing and recovery.

Correction to: CANPMR syndrome and chromosome 1p32-p31 deletion syndrome coexist in two related individuals affected by simultaneous haplo-insufficiency of CAMTA1 and NFIA genes

An amendment to this paper has been published and can be accessed via the original article.

Training load characteristics and injury and illness risk identification in elite youth ski racing: A prospective study

PURPOSE

The study aimed to investigate the role of training load characteristics and injury and illness risk in youth ski racing.

METHODS

The training load characteristics as well as traumatic injuries, overuse injuries, and illnesses of 91 elite youth ski racers (age = 12.1 ± 1.3 years, mean ± SD) were prospectively recorded over a period of 1 season by using a sport-specific online database. Multiple linear regression analyses were performed to monitor the influence of training load on injuries and illnesses. Differences in mean training load characteristics between preseason, in-season, and post-season were calculated using multivariate analyses of variance.

RESULTS

Differences were discovered in the number of weekly training sessions (p = 0.005) between pre-season (4.97 ± 1.57) and post-season (3.24 ± 0.71), in the mean training volume (p = 0.022) between in-season (865.8 ± 197.8 min) and post-season (497.0 ± 225.5 min) and in the mean weekly training intensity (Index) (p = 0.012) between in-season (11.7 ± 1.8) and post-season (8.9 ± 1.7). A total of 185 medical problems were reported (41 traumatic injuries, 12 overuse injuries, and 132 illnesses). The weekly training volume and training intensity was not a significant risk factor for injuries (p > 0.05). Training intensity was found to be a significant risk factor for illnesses in the same week (β = 0.348; p = 0.044; R² = 0.121) and training volume represents a risk factor for illnesses in the following week (β = 0.397; p = 0.027; R² = 0.157).

CONCLUSION

A higher training intensity and volume were associated with increased illnesses, but not with a higher risk of injury. Monitoring training and ensuring appropriate progression of training load between weeks may decrease incidents of illness in-season.

The superficial medial collateral ligament is the major restraint to anteromedial instability of the knee

PURPOSE

The purpose of the present study was to determine how the medial structures and ACL contribute to restraining anteromedial instability of the knee.

METHODS

Twenty-eight paired, fresh-frozen human cadaveric knees were tested in a six-degree of freedom robotic setup. After sequentially cutting the dMCL, sMCL, POL and ACL in four different cutting orders, the following simulated clinical laxity tests were applied at 0°, 30°, 60° and 90° of knee flexion: 4 Nm external tibial rotation (ER), 4 Nm internal tibial rotation (IR), 8 Nm valgus rotation (VR) and anteromedial rotation (AMR)-combined 89 N anterior tibial translation and 4 Nm ER. Knee kinematics were recorded in the intact state and after each cut using an optical tracking system. Differences in medial compartment translation (AMT) and tibial rotation (AMR, ER, IR, VR) from the intact state were then analyzed.

RESULTS

The sMCL was the most important restraint to AMR, ER and VR at all flexion angles. Release of the proximal tibial attachment of the sMCL caused no significant increase in laxity if the distal sMCL attachment remained intact. The dMCL was a minor restraint to AMT and ER. The POL controlled IR and was a minor restraint to AMT and ER near extension. The ACL contributed with the sMCL in restraining AMT and was a secondary restraint to ER and VR in the MCL deficient knee.

CONCLUSION

The sMCL appears to be the most important restraint to anteromedial instability; the dMCL and POL play more minor roles. Based on the present data a new classification of anteromedial instability is proposed, which may support clinical examination and treatment decision. In higher grades of anteromedial instability an injury to the sMCL should be suspected and addressed if treated surgically.

Man against machine reloaded: performance of a market-approved convolutional neural network in classifying a broad spectrum of skin lesions in comparison with 96 dermatologists working under less artificial conditions

BACKGROUND

Convolutional neural networks (CNNs) efficiently differentiate skin lesions by image analysis. Studies comparing a market-approved CNN in a broad range of diagnoses to dermatologists working under less artificial conditions are lacking.

MATERIALS AND METHODS

One hundred cases of pigmented/non-pigmented skin cancers and benign lesions were used for a two-level reader study in 96 dermatologists (level I: dermoscopy only; level II: clinical close-up images, dermoscopy, and textual information). Additionally, dermoscopic images were classified by a CNN approved for the European market as a medical device (Moleanalyzer Pro, FotoFinder Systems, Bad Birnbach, Germany). Primary endpoints were the sensitivity and specificity of the CNN's dichotomous classification in comparison with the dermatologists' management decisions. Secondary endpoints included the dermatologists' diagnostic decisions, their performance according to their level of experience, and the CNN's area under the curve (AUC) of receiver operating characteristics (ROC).

RESULTS

The CNN revealed a sensitivity, specificity, and ROC AUC with corresponding 95% confidence intervals (CI) of 95.0% (95% CI 83.5% to 98.6%), 76.7% (95% CI 64.6% to 85.6%), and 0.918 (95% CI 0.866-0.970), respectively. In level I, the dermatologists' management decisions showed a mean sensitivity and specificity of 89.0% (95% CI 87.4% to 90.6%) and 80.7% (95% CI 78.8% to 82.6%). With level II information, the sensitivity significantly improved to 94.1% (95% CI 93.1% to 95.1%; P < 0.001), while the specificity remained unchanged at 80.4% (95% CI 78.4% to 82.4%; P = 0.97). When fixing the CNN's specificity at the mean specificity of the dermatologists' management decision in level II (80.4%), the CNN's sensitivity was almost equal to that of human raters, at 95% (95% CI 83.5% to 98.6%) versus 94.1% (95% CI 93.1% to 95.1%); P = 0.1. In contrast, dermatologists were outperformed by the CNN in their level I management decisions and level I and II diagnostic decisions. More experienced dermatologists frequently surpassed the CNN's performance.

CONCLUSIONS

Under less artificial conditions and in a broader spectrum of diagnoses, the CNN and most dermatologists performed on the same level. Dermatologists are trained to integrate information from a range of sources rendering comparative studies that are solely based on one single case image inadequate.

Compositional MRI of the anterior cruciate ligament of professional alpine ski racers: preliminary report on seasonal changes and load sensitivity

The purpose of this study was to investigate potential changes in the anterior cruciate ligament (ACL) structure of alpine ski racers over the course of an entire season using quantitative magnetic resonance imaging (T2* mapping). The dominant legs of three alpine ski racers were examined on a 3-T MR scanner four times at 3-month intervals. Multi-echo sequences for T2* maps, which were coregistered with high-resolution morphological sequences for reproducible definition of ACL regions of interest, were acquired. Means and standard deviations of T2* values from the central and femoral portion of the ACL were extracted and presented in a descriptive manner. T2* values were subject to seasonal changes, which were most pronounced in the ligament central region. Substantial increases (+ 41%) occurred between the measurements taken in January and April. A partial recovery of T2* (-19%) was observed in the July follow-up. The increased T2* times may reflect decreased stress tolerance and increased susceptibility for fatigue tears at the end of the competitive season. Further research in larger samples is required. The likeliness of ACL tears may depend on the precedent history of mechanical loading and vary in professional athletes over the course of the competitive season.

The role of health literacy in orthopaedic rehabilitation after total knee and hip arthroplasty: A scoping review

BACKGROUND

Health literacy (HL) is a key aspect in empowering patient education as part of orthopaedic rehabilitation after total knee or hip arthroplasty (TKA/THA).

OBJECTIVES

This scoping review aims to demonstrate the prevalence of patient-related outcome measures in studies on the effectiveness of orthopaedic rehabilitation of older people after TKA/THA. The review also focuses on the identification of outcome measures that assess patients' HL or HL-related aspects.

METHODS

A scoping literature search was conducted using the JBI methodology for scoping reviews. The databases MEDLINE (PubMed), CINAHL Complete, The Cochrane Library, Academic Search Elite, and ERIC were searched with keywords and phrases to find relevant literature. Identified outcome measures were conceptually analysed in a peer reviewed procedure. Those with suspected HL-related content were analysed at item level. Text analyses were performed using MAXQDA.

RESULTS

117 papers were included in this review. 45 patient-related outcome measures could be found, 2 of which assess HL-related aspects. No paper could be found that assessed patients' HL in orthopaedic rehabilitation after TKA/THA.

CONCLUSIONS

HL has hitherto been of limited importance in orthopaedic rehabilitation. Health professionals are responsible for assessing patients' health literacy and developing appropriate strategies for patient education in the context of orthopaedic rehabilitation.

Remodeling the Skeletal Muscle Extracellular Matrix in Older Age-Effects of Acute Exercise Stimuli on Gene Expression

With advancing age, the skeletal muscle extracellular matrix (ECM) undergoes fibrotic changes that may lead to increased muscle stiffness, injury susceptibility and strength loss. This study tested the potential of different exercises to counter these changes by stimulating the activity of genes associated with ECM remodeling. Twenty-six healthy men (66.9 ± 3.9 years) were stratified to two of four groups, performing unilateral (i) conventional resistance exercise, (ii) conventional resistance exercise followed by self-myofascial release (CEBR), (iii) eccentric-only exercise (ECC) or (iv) plyometric jumps (PLY). The non-trained leg served as control. Six hours post-exercise, vastus lateralis muscle biopsy samples were analyzed for the expression of genes associated with ECM collagen synthesis (COL1A1), matrix metallopeptidases (collagen degradation; MMPs) and peptidase inhibitors (TIMP1). Significant between-group differences were found for MMP3, MMP15 and TIMP1, with the greatest responses in MMP3 and TIMP1 seen in CEBR and in MMP15 in ECC. MMP9 (3.24–3.81-fold change) and COL1A1 (1.47–2.40-fold change) were increased in CEBR and PLY, although between-group differences were non-significant. The expression of ECM-related genes is exercise-specific, with CEBR and PLY triggering either earlier or stronger remodeling than other stimuli. Training studies will test whether execution of such exercises may help counter age-associated muscle fibrosis.

[Artificial intelligence and smartphone program applications (Apps) : Relevance for dermatological practice]

ADVANTAGES OF ARTIFICIAL INTELLIGENCE (AI)

With responsible, safe and successful use of artificial intelligence (AI), possible advantages in the field of dermato-oncology include the following: (1) medical work can focus on skin cancer patients, (2) patients can be more quickly and effectively treated despite the increasing incidence of skin cancer and the decreasing number of actively working dermatologists and (3) users can learn from the AI results. POTENTIAL DISADVANTAGES AND RISKS OF AI USE: (1) Lack of mutual trust can develop due to the decreased patient-physician contact, (2) additional time effort will be necessary to promptly evaluate the AI-classified benign lesions, (3) lack of adequate medical experience to recognize misclassified AI decisions and (4) recontacting a patient in due time in the case of incorrect AI classifications. Still problematic in the use of AI are the medicolegal situation and remuneration. Apps using AI currently cannot provide sufficient assistance based on clinical images of skin cancer.

REQUIREMENTS AND POSSIBLE USE OF SMARTPHONE PROGRAM APPLICATIONS

Smartphone program applications (apps) can be implemented responsibly when the image quality is good, the patient's history can be entered easily, transmission of the image and results are assured and medicolegal aspects as well as remuneration are clarified. Apps can be used for disease-specific information material and can optimize patient care by using teledermatology.