The Ecological Footprint of COVID-19 mRNA Vaccines: Estimating Greenhouse Gas Emissions in Germany.

Compared to the medical, economic and social implications of COVID-19 vaccinations, little attention has been paid to the ecological balance to date. This study is an attempt to estimate the environmental impact of two mRNA vaccines in terms of CO2 equivalents with respect to their different freezing strategies and supply chain organization. Although it is impossible to accurately calculate the actual environmental impact of the new biochemical synthesis technology, it becomes apparent that transport accounts for up to 99% of the total carbon footprint. The emissions for air freight, road transportation and last-mile delivery are nearly as 19 times the emissions generated from ultra-deep freeze technologies, the production of dry ice, glass and medical polymers for packaging. The carbon footprint of a single mRNA vaccine dose injected into a patient is about 0.01 to 0.2 kg CO2 equivalents, depending on the cooling technology and the logistic routes to the vaccination sites in Germany.

Favorable Reoperation Rate at 2 Years Following Repair of Horizontal Cleavage Tears Using an All Suture-Based Technique: A Prospective, Multicenter Trial.

PURPOSE: This prospective, multicenter trial evaluates the clinical success (as measured by reoperation rates and improvements in patient-reported outcome measures) of using circumferential compression stitches with all-suture techniques for horizontal cleavage tears (HCTs) of the meniscus. METHODS: Investigators enrolled 30 patients (mean age, 38.2 years; standard deviation, 11.1 years) aged 18 to 60 years with HCTs in the symptomatic compartment at 8 centers in the United States who underwent HCT repair with all-suture circumferential stitches using a self-retrieving all-inside suture passing device. Postoperative follow-up visits were conducted at 6 months, 1 year, and 2 years. Study outcomes included freedom from reoperation of the index meniscus repair site; knee pain and function, as measured by International Knee Documentation Committee Knee evaluation (IKDC), Knee injury and Osteoarthritis Outcome Score, Lysholm Knee Scale, and Tegner Activity Scale; and serious complications observed during the study. Minimal clinically important difference at 1 year was assessed for IKDC and Lysholm. RESULTS: Twenty-three patients had 2-year follow-up data available. Freedom from reoperation was 96.0% at 6 months (26/27, 91.7% at 1 year [23/25], and 82.6% at 2 years [19/23]). Significant improvement was observed in over baseline at 2 years for IKDC (36.7-82.5; P < .001), Knee injury and Osteoarthritis Outcome Score (52.2-89.3; P < .001), Lysholm (50.2-87.4; P < .001), and Tegner scores (3.3-5.3; P = .007). Minimal clinically important difference was met or exceeded for IKDC and Lysholm scores at 1 year 69.2% and 65.4% of patients, respectively. Four patients (6.7%) experienced serious complications, of which 2 were assessed as being related to the procedure. CONCLUSIONS: Repair of HCTs using all-suture circumferential stitches placed with a self-retrieving all-inside suture passing device leads to a favorable reoperation rate (17.4%), significant improvements in clinical outcomes, and an acceptable rate of serious complications (6.7%) at 2 years, supporting the viability of this treatment approach in this indication. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Editorial Commentary: False-Positive Meniscus Pseudotear on Magnetic Resonance Imaging: A False Sign That Rings True.

The false-positive finding of anterior horn meniscus (pseudo)tear on magnetic resonance imaging (MRI) is an important finding of which to be aware. We have recently seen awareness similarly raised regarding root tears of the meniscus, which, if overlooked, could have detrimental consequences. Manifestations of the MRI finding of meniscus pseudotear arise from the variability of the insertion of the transverse geniculate ligament into the anterior horn of the lateral meniscus. Bearing in mind that anterior knee pain is a common reason that patients present for an orthopaedic and sports medicine evaluation, the understanding that this MRI finding does not represent a true meniscus tear may save patients from unnecessary arthroscopic surgery.

In-Office Needle Arthroscopy Can Evaluate Meniscus Tear Repair Healing as an Alternative to Magnetic Resonance Imaging.

PURPOSE: To assess the healing of horizontal cleavage tears of the meniscus 1 year after surgical repair and to determine what modality is best to determine healing. METHODS: Patients were prospectively followed for 12 months after surgical meniscus repair using a circumferential compression stitch. Inclusion criteria were preoperative magnetic resonance imaging (MRI) evidence of horizontal cleavage tear, age between 18 and 50 years, and no concomitant anterior cruciate ligament reconstruction. Patients were excluded if they were >50 years old, had a meniscus tear pattern other than horizontal cleavage tear, and underwent concomitant ligament reconstruction. MRIs were performed 1-year postoperatively for evaluation of repair healing. Preoperative and postoperative MRIs of tears were evaluated blindly by a musculoskeletal radiologist. In-office needle arthroscopy was performed at 6 months post-operatively. RESULTS: Eight patients were included and had surgery between March 2016 and November 2017. There were 4 medial and 4 lateral meniscus tears. No patients had recurrence of preoperative symptoms or evidence of retear. Six repairs evaluated by in-office needle (at 5.9 months postsurgery) arthroscopy demonstrated complete healing. Seven of the 8 patients had grade III changes on preoperative MRI, and 1 patient had grade IIc changes. On postoperative MRI, 5 of 7 patients had grade III changes, 1 patient had IIc changes, and 1 had IIb changes. There was no significant difference in the proportion of patients with grade III changes preoperatively compared with postoperatively (P = .57). One of 8 patients with preoperative MRIs demonstrated extrusion where no patients demonstrate postoperative MRI evidence of extrusion (P = .47). CONCLUSIONS: Horizontal cleavage meniscal tears repaired with a circumferential compression stitch demonstrate healing on in-office needle arthroscopy 6 months after surgery. No evidence of incomplete or failed healing was found. MRI at 1 year after surgery demonstrated residual tear evidence for all patients. LEVEL OF EVIDENCE: IV, therapeutic case series.

Meniscus Tear Management: Indications, Technique, and Outcomes.

Meniscus tears are commonly encountered in the clinical and operative setting and vary in presentation, including bucket-handle, radial, and horizontal cleavage tears. Historically, tears were treated with benign neglect or partial meniscectomy. However, a great deal of subsequent research has highlighted the biomechanical consequences of tears and meniscectomy, including increased peak local contact forces, progressive postmeniscectomy arthritis, and subsequent arthroplasty. With the advent and evolution of repair devices, increasing attention is being turned to the ideal restorative treatment of meniscus tears. Successful meniscus repair is centered about the ABCs of repair: Anatomic reduction, Biologic preparation and augmentation, and Circumferential compression. Recent advances in repair techniques have included microfracture of the intercondylar notch to provide healing factors and marrow cells for augmented healing, all-inside suture devices enabling the reduction and fixation tears without the need for additional assistants and the morbidity of inside-out exposure, and circumferential compression combined with clot augmentation to reduce and fix horizontal cleavage tears and recreate biomechanics to within 15% of baseline contact forces. Clinical outcomes of meniscus repair using modern techniques have been promising, with reapproximation of native joint biomechanics, substantial improvements in patient subjective outcome scores, and satisfactory reoperation rates. With implementation of the ABCs of meniscus repair as well as the continued expansion of the orthopedic surgeons' meniscus repair toolbox, restoration and preservation of the meniscus are increasingly possible across the spectrum of tear types.

Editorial Commentary: A Stitch in Time May Save the Meniscus but Not the Articular Cartilage?

Early-generation meniscal fixators sometimes caused iatrogenic articular cartilage damage. This resulted in injury to the very structure one tries to preserve when repairing a meniscal tear. Advances in suture-based meniscal implants and all-inside suture devices have allowed us to safely repair meniscal tears, even ones thought previously irreparable, and without the need for a secondary incision. As the techniques for meniscal repair continue to improve, orthopaedic surgeons should be encouraged to consider repair with more complex meniscal tear patterns.

Meniscus Root Repair vs Meniscectomy or Nonoperative Management to Prevent Knee Osteoarthritis After Medial Meniscus Root Tears: Clinical and Economic Effectiveness.

BACKGROUND: Medial meniscus root tears are a common knee injury and can lead to accelerated osteoarthritis, which might ultimately result in a total knee replacement. PURPOSE: To compare meniscus repair, meniscectomy, and nonoperative treatment approaches among middle-aged patients in terms of osteoarthritis development, total knee replacement rates (clinical effectiveness), and cost-effectiveness. STUDY DESIGN: Meta-analysis and cost-effectiveness analysis. METHODS: A systematic literature search was conducted. Progression to osteoarthritis was pooled and meta-analyzed. A Markov model projected strategy-specific costs and disutilities in a cohort of 55-year-old patients presenting with a meniscus root tear without osteoarthritis at baseline. Failure rates of repair and meniscectomy procedures and disutilities associated with osteoarthritis, total knee replacement, and revision total knee replacement were accounted for. Utilities, costs, and event rates were based on literature and public databases. Analyses considered a time frame between 5 years and lifetime and explored the effects of parameter uncertainty. RESULTS: Over 10 years, meniscus repair, meniscectomy, and nonoperative treatment led to 53.0%, 99.3%, and 95.1% rates of osteoarthritis and 33.5%, 51.5%, and 45.5% rates of total knee replacement, respectively. Meta-analysis confirmed lower osteoarthritis and total knee replacement rates for meniscus repair versus meniscectomy and nonoperative treatment. Discounted 10-year costs were $22,590 for meniscus repair, as opposed to $31,528 and $25,006 for meniscectomy and nonoperative treatment, respectively; projected quality-adjusted life years were 6.892, 6.533, and 6.693, respectively, yielding meniscus repair to be an economically dominant strategy. Repair was either cost-effective or dominant when compared with meniscectomy and nonoperative treatment across a broad range of assumptions starting from 5 years after surgery. CONCLUSION: Repair of medial meniscus root tears, as compared with total meniscectomy and nonsurgical treatment, leads to less osteoarthritis and is a cost-saving intervention. While small confirmatory randomized clinical head-to-head trials are warranted, the presented evidence seems to point relatively clearly toward adopting meniscus repair as the preferred initial intervention for medial meniscus root tears.

Meniscus Repair and Replacement.

The importance of preserving the function of the meniscus is seen with renewed interest. There has been an evolution of arthroscopic meniscus repair from inside-out, outside-in, meniscal fixators, to all-inside suturing techniques. Tear patterns once ignored or thought to be irreparable, such as root tears and horizontal cleavage tears, have recently been undergoing repair with promising results. Newer techniques have also recently allowed surgeons to address postmeniscectomy knee pain. Replacing lost tissue with scaffolds or replacing the meniscus with an allograft helps restore function and reduce degenerative changes.

Editorial Commentary: Should I Order Prophylactic Antibiotics for My Next Knee Scope?

Postoperative infections are going to happen. The question of whether prophylactic antibiotics can lower the infection rate in routine knee arthroscopy is investigated. Although a large number of cases were included in the study, the results did not reach statistical significance. Nevertheless, a significant trend toward a lower incidence of deep infection was seen when antibiotics were given.

Clinical Application of Scaffolds for Partial Meniscus Replacement.

Meniscal tears are common injuries often treated by partial meniscectomy. This may result in altered joint contact mechanics which in turn may lead to worsening symptoms and an increased risk of osteoarthritis. Meniscal scaffolds have been proposed as a treatment option aimed at reducing symptoms while also potentially reducing progression of degenerative change. There are 2 scaffolds available for clinical use at the present time; Collagen Meniscus Implant and Actifit. Medium-term to long-term data (4.9 to 11.3 y) demonstrate efficacy of partial meniscus replacement. The patients who seem to benefit most are chronic postmeniscectomy rather than acute meniscal injuries. Herein we report on available clinical data for Collagen Meniscus Implant and Actifit while describing our preferred surgical technique and postoperative rehabilitation program.

Physical examination and imaging of medial collateral ligament and posteromedial corner of the knee.

The medial collateral ligament (MCL) is the most commonly injured knee ligament. Most will heal well with nonoperative treatment. However, not all medial knee injuries are the same. A detailed physical examination can help determine the severity of the medial-sided injury. When combined with advanced imaging, the examination will delineate damage to associated medial knee structures, including the location of MCL damage, posteromedial capsule injuries, and combined cruciate injuries. Failure to recognize MCL injuries that may be prone to chronic laxity can lead to significant disability, joint damage, and failure of concomitant cruciate ligament reconstructions. Magnetic resonance imaging is the mainstay of diagnostic imaging, with coronal sequences allowing full assessment of the MCL complex. Tangential views aid in the diagnosis of concomitant injuries. Stress radiography can play a role in evaluating MCL healing and subtle chronic laxity. Ultrasonography is also gaining acceptance as a means to assess MCL injuries. Use of a detailed examination and advanced imaging will allow optimal treatment of medial knee injuries and improve clinical outcomes.

Repair of horizontal meniscus tears: a systematic review.

PURPOSE: Despite the well-documented advantages of meniscal repair over meniscectomy, horizontal cleavage tears (HCTs) are often not repaired. Reported reasons include difficulty performing the repair, potential suture failure due to mechanical stresses, and poor healing rates. In addition, many surgeons have the perception that debriding the tear until the superior and inferior laminae are stable results in a good clinical outcome. Furthermore, many of the tears occur in patients who are older than the generally accepted indicated age for repair and may also have a degenerative component, making them potentially less likely to benefit from repair. This review was performed to evaluate the published outcomes of HCT repairs and test the hypothesis that surgically repaired HCTs have an unacceptably low rate of success. METHODS: A systematic search of the PubMed and Embase databases was performed in December 2013 to identify studies in which meniscal HCTs were repaired. Inclusion criteria for the analysis were English language, reference to a patient with an HCT repaired by any method, and a report of at least 1 postoperative outcome. For the purposes of this review, a failed outcome was defined as the need for reoperation. RESULTS: More than 16,000 abstracts were returned in the search. From these abstracts, we identified 210 articles for further review, of which 9 met the inclusion criteria. A total of 98 repairs of horizontal tears were evaluated in these studies. By use of reoperation as the criterion for treatment failure, 77 of the repairs were successful, for an overall success rate of 77.8%. CONCLUSIONS: The literature does not support the hypothesis that surgically repaired HCTs have an unacceptably low rate of success. Rather, our results show that existing studies of repaired HCTs show a comparable success rate to repairs of other types of meniscal tears. LEVEL OF EVIDENCE: Level IV, systematic review of Level IV studies.

Metal Oxides and Ion-Exchanging Surfaces as pH Sensors in Liquids: State-of-the-Art and Outlook.

Novel applications of online pH determinations at temperatures from -35 °C to 130 °C in technical and biological media, which are all but ideal aqueous solutions, require new approaches to pH monitoring. The glass electrode, introduced nearly hundred years ago, and chemical sensors based on field effect transistors (ISFET) show specific drawbacks with respect to handling and long-time stability. Proton sensitive metal oxides seem to be a promising and alternative to the state-of-the-art measuring methods, and might overcome some problems of classical hydrogen electrodes and reference electrodes.

Anterior cruciate ligament reconstruction with Achilles tendon allografts in revisions and in patients older than 30.

We evaluated the results of anterior cruciate ligament (ACL) reconstruction using an Achilles tendon allograft in revisions and in patients older than 30. Results from 23 consecutive patients (mean age, 43 years) who underwent ACL reconstruction with fresh-frozen, irradiated (22/23) Achilles allografts were retrospectively reviewed. Seven cases were revisions. Patients were evaluated with physical examination, questionnaires, and x-rays. Twenty of the 23 patients were evaluated a mean of 28 months after surgery. There were 5 failures (21%); 3 acute failures were not evaluated at follow-up. One patient had an infection that required graft removal, 2 patients had mechanical failure of the grafts, and 2 had displacements of more than 5.5 mm as measured with a KT-1000 arthrometer. The 18 clinically successful cases had full motion, no thigh atrophy, and no effusion. Pivot shift scores were 55% A and 45% B on the International Knee Documentation Committee (IKDC) scale. Lachman scores were 40% A, 55% B, and 5% C on the IKDC scale. The KT-1000 difference was a mean of 2.9 mm at final follow-up. However, knees loosened a mean of 4.5 mm from the immediate postoperative measurements (P<.0001). Mean Lysholm and Tegner scores were 86.8 and 5.2, respectively. Tibial tunnel diameter increased by 3.1 mm on anteroposterior x-rays and 3.0 mm on lateral x-rays. Five patients developed mild medial compartment arthritis. Four of the 5 grafts with failures were from donors older than 40. Postoperative complications included deep vein thrombosis and inflammatory effusion (white blood cell count, 15,000). Twenty-one percent of ACL reconstructions with Achilles tendon allografts failed. Grafts deemed successful still had significant loosening at final follow-up. Allografts from donors older than 40 may have played a role in these failures. From the data in this study, it appears that surgeons should scrutinize the source of the allograft tissue and the age of the donor.

Magnetic resonance imaging appearance of the shoulder after subacromial injection with corticosteroids can mimic a rotator cuff tear.

Subacromial injections have been used to treat rotator cuff problems. Previous studies have noted the difficulty in performing accurate injections into this area. In addition, one must also question the effects that misplaced corticosteroids could have on the surrounding tissues. In this case, a 51-year-old woman presented with several weeks of left shoulder pain and was diagnosed with rotator cuff tendonitis. After a subacromial injection with betamethasone and lidocaine, the patient noted 3 weeks of near complete pain relief, followed by a return of her symptoms. A magnetic resonance imaging scan obtained 7 weeks after the injection showed a full-thickness tear of the supraspinatus tendon. Five weeks later, the patient underwent arthroscopic evaluation of the shoulder and subacromial decompression. The rotator cuff tendons were noted to be intact and normal in appearance. The patient eventually had full resolution of her symptoms. Six months postoperatively, she underwent a new scan that showed a normal supraspinatus tendon. Apparently, the subacromial injection penetrated the anterior half of the supraspinatus tendon, causing a transient effect and signal change. One should use caution in the interpretation of magnetic resonance imaging scans of the shoulder soon after the injection of corticosteroids.

Physical examination and imaging of the medial collateral ligament and posteromedial corner of the knee.

The medial side is one of the most commonly injured areas of the knee. The anatomy, diagnosis, and treatment of medial collateral ligament and posteromedial corner (PMC) injuries can be challenging. Understanding the mechanism of injury and performing a thorough physical examination and radiographic evaluation is essential. Frequently, there are concomitant meniscal and other ligament injuries associated with medial-side injuries. Correct identification of all injured structures is important, as missed diagnoses can lead to significant disability. Unrecognized PMC injuries have been implicated in anteromedial rotary instability and failed anterior cruciate ligament reconstructions. Valgus stress testing is the cornerstone for the identification of medial-side knee injuries. Coronal sequences from magnetic resonance imaging are the most useful tool to view the medial collateral ligament and posteromedial structures. Stress x-rays and ultrasound may also be helpful. Thorough physical examination and imaging of injuries to the PMC should dictate the appropriate treatment for optimal results.

Antibiotic prophylaxis for arthroscopic surgery.

Because the incidence of infection in arthroscopic surgery is very low, one can argue both for and against the use of prophylactic antibiotics. Administering antibiotics adds expense and introduces the potential for both exposure to allergic reactions and selection of resistant organisms. Antibiotics are given to prevent deep infection; such treatment may require further surgery, prolonged use of intravenous antibiotics, high costs, and outcomes that may be less than satisfactory. An answer to this controversial issue would require a study that includes large numbers of patients to make it adequately statistically powered because the incidence of infection is so low. No such research has yet been performed, and the American Academy of Orthopaedic Surgeons (AAOS) has not produced an advisory statement addressing this issue. It is the opinion of this author that antibiotic prophylaxis is indicated for arthroscopic surgery. Despite surgical team best practices, mistakes can occur. This has led the AAOS to issue an advisory statement to prevent wrong-site surgery. Similarly, complacency with repetition may produce breaks in sterility that may occasionally go undetected. Antibiotic usage may help to reduce infection in such circumstances. Arthroscopic procedures are not always performed in healthy patients. The risk of infection in "high-risk" patients, such as those with diabetes, immune problems, and skin disorders, may be reduced by prophylactic antibiotics. How one defines a case as arthroscopic can be debated. If small incisions are made, or if the scope is used for only a portion of the procedure, many would still consider the case to be arthroscopic. Surgeries are becoming more complex, which adds to their duration. Some cases also involve the use of implants such as interference screws and suture anchors. It is my opinion that antibiotics should be used in these situations. The potential exists for litigation in cases of infection. Medicolegally, it is easier to argue that all measures were taken to prevent infection if prophylactic antibiotics were given, although patient care issues supersede defensive medicine. Risk of infection in arthroscopic surgery is multifactorial, and antibiotic prophylaxis is only one facet of the issue. Although it is my opinion that antibiotics are recommended, others could be justified in supporting the opposite opinion, pending appropriately designed and adequately powered future investigations.

Unsatisfactory clinical results of meniscal repair using the meniscus arrow.

PURPOSE: The all-inside technique using the Meniscus Arrow (Bionx Implants, Malvern, PA) has become a popular method for repairing meniscal tears. The few published clinical studies have been promising. The present study, with longer follow-up and larger numbers, does not show encouraging results. The clinical efficacy, failure rate, and associated complications of meniscal repair using the Meniscus Arrow with a minimum follow-up of 3 years are described. TYPE OF STUDY: Consecutive case series. METHODS: We studied 60 consecutive meniscal repairs in 57 patients (average age, 27 years) using exclusively the Meniscus Arrow. Follow-up averaged 54 months (range, 36 to 70 months). The anterior cruciate ligament (ACL) was intact in 12 knees (12 repairs), whereas 42 patients (45 repairs) underwent concomitant ACL reconstruction. One patient (2 repairs) had radiofrequency shrinkage of the ACL and another patient (1 repair) underwent concomitant arthroscopic fixation of a tibial eminence fracture. RESULTS: Seventeen of 60 repairs (28%) were documented as failures by repeat arthroscopy or magnetic resonance imaging; 5 of 12 repairs (42%) performed in knees with an intact ACL failed; and 9 of 45 menisci (20%) repaired in conjunction with an ACL reconstruction also failed. The remaining 3 failures occurred in knees with unsuccessful ACL procedures. The type of meniscus tear and the postoperative rehabilitation regimen were also factors that influenced the success rate in this study. Fifteen patients (26%) underwent a second operation because of persistent postoperative symptoms. One patient, whose repair failed, deferred a repeat operation after sustaining a postoperative pulmonary embolism. CONCLUSIONS: Contrary to previously published studies that reported good clinical results, this series revealed a 28% failure rate with significant postoperative complications, such as chondral scoring, fixator breakage, and postoperative joint-line irritation. This study has raised concerns about the continued liberal use of the Bionx Meniscus Arrow, leading the authors to abandon its use for repairing meniscal tears. LEVEL OF EVIDENCE: Level IV.

Electromyographic evaluation after primary repair of massive rotator cuff tears.

Anatomic dissections have suggested that mobilization of the supraspinatus and infraspinatus tendons greater than 1 cm may cause suprascapular nerve injury. This study evaluated rotator cuff function by use of electromyographic (EMG) analysis after primary repair of massive tears in 9 patients. All subjects had massive rotator cuff tears involving at least the entire supraspinatus and entire infraspinatus tendons. Rotator cuff advancement averaged 2.5 cm (range, 2.0-3.5 cm). No EMG evidence of suprascapular nerve injury was found postoperatively. The UCLA shoulder score improved from a preoperative mean of 11 to a postoperative mean of 28. There was 1 excellent, 6 good, 1 fair, and 1 poor result. The poor result was due to a documented failed repair. The EMG results suggest that mobilization and advancement of the rotator cuff up to 3.5 cm during primary repair may be performed safely without as much risk to the suprascapular nerve as anatomic studies would suggest.