Electrocautery in arthroscopic surgery: intra-articular fluid temperatures above 43 °C cause potential tissue damage.

PURPOSE: The use of electrocautery during arthroscopy may heat intra-articular saline and subsequently damage intra- and extra-articular tissue. Newer electrocautery devices have the ability to measure the outflow fluid temperature and switch off before reaching a certain threshold; however, the scientific evidence establishing these temperature thresholds' potential for inadvertent damage is lacking. The aim of this study was to analyse current available literature on temperature thresholds for tissue damage after exposure to heated fluid and provide a recommendation for the maximum temperature of intra-articular fluid to prevent tissue damage. METHODS: In February 2018, a systematic literature review was performed using the MEDLINE/PubMed and Embase databases. Inclusion was limited to studies investigating temperature thresholds for thermal damage to at least one of the tissues of interest: skin, bone, cartilage, soft tissues, and nerves. Studies not reporting specific temperature thresholds for thermal damage were excluded. RESULTS: Twenty articles were selected for the final evaluation and data extraction. Varying temperature thresholds, based on the lowest reported temperature causing tissue damage, were found for the different tissues of interest: 44 °C for dermal tissues, between 47 and 50 °C for bony tissues, 50 °C for cartilage, between 43 and 55 °C for soft tissues, and 43 °C for nerves. CONCLUSION: Based on the current literature, a temperature threshold for intra-articular fluid of 43 °C during an arthroscopic procedure is recommended to prevent tissue damage. Higher temperatures may cause damage to surrounding intra- and extra-articular tissues. The threshold for irreversible damage is likely to be higher. In clinical practise, one should be aware of possible heating of intra-articular fluid when using electrocautery and related risk of tissue damage. LEVEL OF EVIDENCE: III.

[Decellularized cadaveric human artery for substitution of connective tissue and smooth muscle defects on the example of tunica albuginea of penis (experimental work)]. / Ispol'zovanie detselliuliarizirovannoi trupnoi arterii cheloveka dlia zameshcheniia defektov soedinitel'notkannykh i gladkomyshechnykh struktur na primere belochnoi obolochki polovogo chlena (éksperimental'naia rabota).

AIM: To analyze experimentally the outcomes of xenotransplantation (cadaveric artery, decellularized cadaveric artery) for tunica albuginea defects repair. MATERIAL AND METHODS: The study included 60 chinchilla rabbits. Rabbits underwent local replacement of tunica albuginea. Animals were divided into 2 groups (group 1 - human cadaveric artery, group 2 - decellularized cadaveric artery). The result was considered after 7, 14 and 30 days postoperatively. RESULTS: Tendency to stasis, sludge-phenomenon and ultimately development of fibrosis of transplantation area were histologically observed in group 1 after 30 days. In group 2 luminal surface of decellularized artery was smoothed, fibrin and blood elements were absent. In group 1 mean level of C-reactive protein was 3.86±0.43, 1.17±0.2 and 0.73±0.16 mg/L after 7, 14 and 30 days respectively. In group 2 the same values were 0.33±0.03, 0.23±0.03 and 0.11±0.02 mg/L. Differences were significant (t =-46.28, t = -25.95, t = -14.84; p<0.0001).

Connective tissue injury in calf muscle tears and return to play: MRI correlation.

OBJECTIVE: The aim of our study was to assess a group of patients with calf muscle tears and evaluate the integrity of the connective tissue boundaries and interfaces. Further, we propose a novel MRI grading system based on integrity of the connective tissue and assess any correlation between the grading score and time to return to play. We have also reviewed the anatomy of the calf muscles. MATERIALS AND METHODS: We retrospectively evaluated 100 consecutive patients with clinical suspicion and MRI confirmation of calf muscle injury. We evaluated each calf muscle tear with MRI for the particular muscle injured, location of injury within the muscle and integrity of the connective tissue structure at the interface. The muscle tears were graded 0-3 depending on the degree of muscle and connective tissue injury. The time to return to play for each patient and each injury was found from the injury records and respective sports doctors. RESULTS: In 100 patients, 114 injuries were detected. Connective tissue involvement was observed in 63 out of 100 patients and failure (grade 3 injury) in 18. Mean time to return to play with grade 0 injuries was 8 days, grade 1 tears was 17 days, grade 2 tears was 25 days and grade 3 tears was 48 days (p<0.001). CONCLUSION: The integrity of the connective tissue can be used to estimate and guide the time to return to play in calf muscle tears.

Validation of a new experimental model of extrusive luxation on maxillary molars of rats: a histological study.

BACKGROUND/AIM: The aim of this study was to test and validate a new model of extrusive luxation trauma on maxillary first molars of rats. MATERIAL AND METHODS: Forty adult male rats (Rattus norvegicus albinus, Wistar; weight = 230-250 g), 45 days old, were divided into eight groups (n = 5): control groups, in which animals were not subjected to any procedure and waited 1 day (GC1D) or 3 days (GC3D) for euthanasia, and experimental groups, in which animals were subjected to forces of 1100cN, 1300cN, or 1500cN and waited 1 or 3 days for euthanasia (GT1100/1D, GT1100/3D, GT1300/1D, GT1300/3D, GT1500/1D, GT1500/3D). In animals of the experimental groups, trauma was produced by an extrusive force in maxillary first right molars. Four-micrometer serial cuts stained with hematoxylin and eosin (HE) were made. Descriptive microscopic analysis of first upper right molar and semi-quantitative analysis (scores 1 to 4) of intensity of acute and chronic inflammation and vascular changes in the periodontal ligament and active and inactive external root resorption were conducted. The distribution of scores in the groups was compared using the Freeman-Halton extension of Fisher's exact test. The significance level was 5%. RESULTS: It was observed that vascular disorders (bleeding) on the periodontal ligament became more evident with increasing extrusive force. CONCLUSIONS: This new method was capable of generating histological changes, proving its secure application in this research area. The 1500cN force produced more damage on the periodontal ligament. CLINICAL RELEVANCE: The validation of a new experimental method can produce more reliable evidence in further research.

[The mechanical strenth characteristics of the biological tissues: the current state-of-the-art]. / Prochnostnye svoistva biologicheskikh tkanei: sovremennoe sostoianie voprosa.

This article reports the results of analysis of the publications in the scientific literature concerning the mechanical strength characteristics of the biological (human) tissues. It is shown that many researchers successfully used the methods and means finding wide applications in the technical disciplines for the investigations into the mechanical strength of such biological objects as skin, tendons, blood vessels, bones, etc. There are thus far no available reports on the studies of the mechanical strength characteristics of the internal organs. At the same time, such studies are of paramount importance for obtaining the materials that might greatly contribute to the better understanding of the mechanisms underlying the development of the lesions in the internal organs. They are likely to enhance objectiveness of expert conclusions in the framework of forensic medical expertise of the injuries to the human body.

The future of bioactive ceramics.

Two important worldwide needs must be satisfied in the future; (1) treatment of the deteriorating health of an aging population and, (2) decreasing healthcare costs to meet the needs of an increased population. The ethical and economic dilemma is how to achieve equality in quality of care while at the same time decreasing cost of care for an ever-expanding number of people. The limited lifetime of prosthetic devices made from first-generation nearly inert biomaterials requires new approaches to meet these two large needs. This paper advises an expanded emphasis on: (1) regeneration of tissues and (2) prevention of tissue deterioration to meet this growing need. Innovative use of bioactive ceramics with genetic control of in situ tissue responses offers the potential to achieve both tissue regeneration and prevention. Clinical success of use of bioactive glass for bone regeneration is evidence that this concept works. Likewise the use of micron sized bioactive glass powders in a dentifrice for re-mineralization of teeth provides evidence that prevention of tissue deterioration is also possible. This opinion paper outlines clinical needs that could be met by innovative use of bioactive glasses and ceramics in the near future; including: regeneration of skeletal tissues that is patient specific and genetic based, load-bearing bioactive glass-ceramics for skeletal and ligament and tendon repair, repair and regeneration of soft tissues, and rapid low-cost analysis of human cell-biomaterial interactions leading to patient specific diagnoses and treatments using molecularly tailored bioceramics.

[Connective tissue and inflammation]. / Kötoszövet és inflammatio.

The author summarizes the structure of the connective tissues, the increasing motion of the constituents, which determine the role in establishing the structure and function of that. The structure and function of the connective tissue are related to each other in the resting as well as inflammatory states. It is emphasized that cellular events in the connective tissue are part of the defence of the organism, the localisation of the damage and, if possible, the maintenance of restitutio ad integrum. The organism responds to damage with inflammation, the non specific immune response, as well as specific, adaptive immunity. These processes are located in the connective tissue. Sterile and pathogenic inflammation are relatively similar processes, but inevitable differences are present, too. Sialic acids and glycoproteins containing sialic acids have important roles, and the role of Siglecs is also highlighted. Also, similarities and differences in damages caused by pathogens and sterile agents are briefly summarized. In addition, the roles of adhesion molecules linked to each other, and the whole event of inflammatory processes are presented. When considering practical consequences it is stressed that the structure (building up) of the organism and the defending function of inflammation both have fundamental importance. Inflammation has a crucial role in maintaining the integrity and the unimpaired somato-psychological state of the organism. Thus, inflammation serves as a tool of organism identical with the natural immune response, inseparably connected with the specific, adaptive immune response. The main events of the inflammatory processes take place in the connective tissue.

The role of ultrasound and magnetic resonance imaging in the evaluation of the forearm interosseous membrane. A review.

The interosseous membrane of the forearm is an important structure to consider in cases of elbow and forearm trauma; it can be injured after elbow or forearm fractures, leading to longitudinal forearm instability. Diagnosis of interosseous membrane injuries is challenging, and failure in diagnosis may result in poor clinical outcomes and complications. Magnetic resonance imaging and ultrasound have shown to be valuable methods for the evaluation of this important structure. Both techniques have advantages and limitations, and its use should be adapted to each specific clinical scenario. This article presents an up-to-date literature review regarding the use of ultrasound and magnetic resonance imaging in the forearm interosseous membrane evaluation.

Repair of intervalvular fibrous body rupture during aortic valve replacement.

The intervalvular fibrosa, the structure that connects the mitral and the aortic valves, can be injured during aortic valve replacement. Although this complication is rare, it may require complex and extensive repair. Herein, we describe management of a damaged aortic-mitral curtain and fibrous body during tissue aortic valve replacement in a patient with mixed connective tissue disorder. A "U" suture repair combining an external and internal reinforcement repair technique via the aorta, without explanting the prosthetic valve technique, is described. The purpose of using the "externalized" buttressed U-stitch was to obliterate any residual cavity and to assure control of hemorrhage externally. Repair of damaged fibrous body during aortic valve replacement (AVR) is challenging. We managed this difficult situation in a satisfactory surgical approach without explanting the aortic prosthesis.

[Bradytrophic tissue. Its histopathological diagnosis and value in trauma surgical and orthopedic expert opinions]. / Bradytrophe Gewebe. Histopathologische Diagnostik und Stellenwert bei unfallchirurgisch-orthopädischen Gutachten.

Expert opinions on the musculoskeletal system are generally required for statutory or private accident insurance purposes in a variety of legal areas and with varying rules of evidence. Since they are also intended for non-medical personnel, terminology needs to be defined and must be comprehensible by all parties. Bradytrophic tissue is the most frequently evaluated aspect of the musculoskeletal system. In this context, the term"degeneration" which was formerly used has been replaced by the term"tissue structure alteration", which takes matrix changes and cellularity into consideration. Thus the significance of histopathological diagnosis of bradytrophic tissue has been put in a new light. Histopathological diagnosis is carried out on the basis of various staining methods, scores and analyses depending on the diagnostic question.

The effect of muscle actions on the level of connective tissue damage.

The aim of this study was to compare the effect of concentric with eccentric muscle actions on the resulting level of damage to connective tissues by urinary concentration of hydroxyproline. Twenty-one male volunteers were divided into control group (CG), experimental concentric group (ECG), and experimental eccentric group (EEG). The measures of hydroxyproline were performed at three times: pretest, fourth week, and posttest. Biceps curl and chest press exercises also were performed with three sets of 10 repetitions two times per week for both experimental groups. Analysis of variance (ANOVA) showed a significant difference between pretest of the CG and pretest of the ECG (p = 0.002), and between pretest and posttest for the EEG (p = 0.029). Therefore, this study concluded that the level of damage to the connective tissue is greater when exercises involving eccentric muscle actions are performed. The continuity of training, however might reduce this damage.

Foreign body extraction from soft tissue by using CT and fluoroscopic guidance: a new technique.

We report on a new minimally invasive technique for the retrieval of a surgical pin fragment after accidental migration into the soft tissue of the shoulder in two patients. The technique is performed under local anaesthesia and uses combined CT and fluoroscopic guidance. The materials used were simple, combining a bone biopsy needle and an endoscopy clamp. Pin displacement was confirmed under fluoroscopic guidance and the clamp was used to withdraw the pin to the cutaneous entry point under CT (step-by-step) guidance. The CT slices provide perfect visualisation of the vascular or nervous structures as well as perfect positioning of the extremity of the trocar relative to the material to be removed. This intervention avoids a second surgical intervention with a longer incision and avoided repeated general anaesthesia.

Outcomes After Arthroscopic Repair in Patients With Tears of Hypertrophic Versus Morphologically Normal Acetabular Labra.

BACKGROUND: Recently, a hypertrophic labrum has been reported in the absence of hip dysplasia, which can possibly contribute to an acetabular labral tear. PURPOSE: To compare the clinical outcomes and complications, including the incidence of iatrogenic acetabular labrum and cartilage injury, in patients with tears of hypertrophic versus morphologically normal acetabular labra over a minimum follow-up period of 2 years and to assess the morphologic changes at follow-up computed tomography arthrography in the 2 groups. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Between January 2010 and December 2016, 20 patients (22 hips) with a hypertrophic labrum underwent arthroscopic hip surgery. A total of 22 patients (22 hips) without a hypertrophic labrum were assigned to the control group based on matching criteria, including age, sex, body mass index, labral tear, and labral repair. Clinical outcomes were assessed with the visual analog scale score, UCLA activity scale score (University of California, Los Angeles), and modified Harris Hip Score. Radiologic outcomes were assessed through serial radiography. Patients were followed for at least 2 years. RESULTS: The mean age at surgery was 42 years. The most common cause of arthroscopic surgery in the study group was an isolated acetabular labral tear without any bony structural abnormalities (68.2%, 15 of 22 hips). All improvements in both groups were statistically significant at the last postoperative follow-up (P < .001). Although the radiologic and clinical outcomes were not significantly different between the groups, the complication rates, including iatrogenic labral perforations and cartilage injury, were significantly higher in patients with hypertrophic acetabular labral tears (9 vs 3, P = .042). The patient-reported satisfaction scores at the last postoperative follow-up were 8.4 and 7.9 in the study and control groups, respectively (P = .351). CONCLUSION: The high rates of patient-reported satisfaction and the clinical outcomes after arthroscopic repair in both groups are encouraging. Arthroscopic treatment in patients with hypertrophic acetabular labral tears should be carefully performed to prevent iatrogenic injury during the surgery, and isolated hypertrophic labral tears can have good results after repair.

MR imaging of overuse injuries in the skeletally immature gymnast: spectrum of soft-tissue and osseous lesions in the hand and wrist.

BACKGROUND: In the pediatric gymnast, stress-related physeal injuries have been well described with characteristic imaging findings. However, a spectrum of overuse injuries, some rarely reported in the literature, can be encountered in the gymnast's hand and wrist. OBJECTIVE: To demonstrate the MR appearance of a spectrum of overuse injuries in the skeletally immature wrist and hand of pediatric gymnasts. MATERIALS AND METHODS: A total of 125 MR exams of the hand and wrist in skeletally immature children were performed at our institution during a 2-year period. Clinical histories were reviewed for gymnastics participation. MR studies of that subpopulation were reviewed and abnormalities tabulated. RESULTS: Of the MR studies reviewed, ten gymnasts were identified, all girls age 12-16 years (mean age 14.2 years) who presented with wrist or hand pain. Three of these children had bilateral MR exams. Abnormalities included chronic physeal injuries in three children. Two girls exhibited focal lunate osteochondral defects. Triangular fibrocartilage tears were present in three girls, one of whom had a scapholunate ligament tear. Two girls manifested metacarpal head flattening and necrosis. CONCLUSION: A variety of soft-tissue and osseous lesions can be encountered in the skeletally immature gymnast. Familiarity with these stress-related injuries is important for accurate diagnosis.

Delayed stenosis as a consequence of angioplasty for subarachnoid hemorrhage-induced vasospasm. Case report.

The authors report a case of restenosis in the bilateral internal carotid arteries (ICAs) following angioplasty for cerebral vasospasm. This 53-year-old woman suffering subarachnoid hemorrhage due to a ruptured posterior communicating artery aneurysm had severe vasospasm and underwent angioplasty of the left and right ICAs and middle cerebral arteries. Two months later, a follow-up CT angiogram revealed bilateral ICA stenoses. Transluminal angioplasty leads to long-term connective tissue damage in the medial and adventitial layers from the disruption of the arrangement of collagen fibers due to stretching and tearing, resulting in loss of transmission of contractile forces. Furthermore, following endothelial cell denudation and stretching and rupture of internal elastic lamina from angioplasty, reendothelialization of the intimal layer composed of smooth muscle cells may also explain the contractile properties of restenosis. Other factors such as macrophage-induced inflammation and reactive oxygen species accumulation may also contribute to restenosis. This is the second reported case of restenosis following angioplasty to treat vasospasm, although restenosis is a known complication of angioplasty for treatment of atherosclerosis. In addition, this is the first case of restenosis in the bilateral ICAs following angioplasty for vasospasm. This report presents an illustrative case study and reviews the pathophysiology of angioplasty and restenosis.

[Soft tissue navigation and image-guided removal of foreign bodies in head and neck surgery]. / Weichteilnavigation im Kopf-Hals-Bereich und navigierte Fremdkörperentfernung.

BACKGROUND: Soft tissue navigation has traditionally been neglected in computer-aided surgery (CAS) because of unpredictable margins of error. In our study, we examined clinical cases in which standard CAS was applied in soft tissue surgery in the head and neck region. Its extended applicability, margins of error, and general performance are described and discussed. MATERIALS AND METHODS: CAS was applied in surgical procedures for six patients. Five patients had foreign bodies in the head and neck region, and one patient displayed uncertain cervical lymph node enlargement. An optoelectrical navigation system (VectorVision(2), BrainLAB) was used in all cases. RESULTS: Using CAS, 10 out of 11 total foreign bodies were identified. Only one glass splinter attached to the eyeball could not be detected by the navigation system. One glass splinter that was deeply buried within the sphenoid bone was easily found but was left untouched. The parapharyngeal lymph node was identified and extracted in a minimally invasive transpalatinal approach. CONCLUSIONS: Soft tissue navigation was successfully applied in all but one case; the success was due to the altered demands in soft tissue navigation as opposed to skull-base surgery. Easy identification of foreign bodies and lymph nodes was possible in the soft tissues of the head and neck, with an acceptable margin of error.

Fiber-based fracture model for simulating soft tissue tearing.

In this paper, we propose a novel approach for simulating soft tissue tearing, using a model that takes into account the existence of fibers within the tissue. These fibers influence the deformation by introducing anisotropy, and impact the direction of propagation for the fracture during tearing. We describe our approach for simulating, in real-time, the deformation and fracture of anisotropic membranes, and we illustrate our method with the simulation of capsulorhexis, one of the critical steps of cataract surgery.

Ultrasound-detected connective tissue involvement in acute muscle injuries in elite athletes and return to play: The French National Institute of Sports (INSEP) study.

OBJECTIVES: Previous MRI studies showed that involvement of connective tissue in muscle injuries may prolong recovery times. The relevance of ultrasound assessment of connective tissue involvement as a prognostic factor is unknown. The aim was to test the hypothesis that ultrasound-detected connective tissue involvement in acute muscle injuries are related to longer recovery times. DESIGN: Cohort study. METHODS: Seventy consecutive elite athletes from the French National Institute of Sports (INSEP) sustaining an acute muscle injury showing positive findings on ultrasound at baseline were included. Ultrasound was systematically performed within 7days after the injury for the assessment of severity (grades 1-4) and type of injury in regard to the absence (M injuries) or presence (C injuries) of connective tissue involvement. The differences in the mean time needed to return to play (RTP) between the different grades and types of injury were assessed using multiple non-parametric tests. RESULTS: When considering the overall grades independently of the type of injury (M or C), an increase in the mean time needed to RTP was observed with the increase of grades (p<0.0001). The same relationship was found when considering grades from M and C injuries separately, with higher grades of injuries exhibiting longer times needed to RTP (p<0.0001). Longer times needed to RTP were observed in athletes demonstrating C injuries in comparison to the ones exhibiting M injuries overall (p=0.002). CONCLUSIONS: Ultrasound-detected connective tissue involvement in acute muscle injuries are related to longer times needed to RTP, especially when disruption is detected.

Injury and regeneration of intramuscular connective tissue subjected to various regimes of distraction.

OBJECTIVE: To investigate the effect on intramuscular connective tissue and passive range of joint motion by the stress produced in limb lengthening. METHODS: An animal model of limb lengthening was established in the tibia of rabbits. Distraction was initiated at a rate of 1 mm/d and 2 mm/d in two steps respectively, and both proceeded until 10% and 20% of the tibia length was achieved. Muscle samples were harvested at the time when distraction ended and at the 4th week of consolidation after the distraction. Scanning electron microscope was applied to observe the morphological changes of the perimysium. The goniometer, which we made for this study, was used to measure the passive range of joint motion. RESULTS: The collagen fibers were partitioned in bundles, crimped and interconnected closely and orderly. In the regime of 1 mm/d distraction with 10% lengthening, no apparent changes of the collagen fiber and passive range of joint motion was demonstrated. When tibia was increased to 20%, the crimped fibers showed a tendency of being straightened while the passive range of joint motion was reduced. The findings remained the same at the 4th week of consolidation. In the regime of 2 mm/d distraction with 10% lengthening, the crimped structure of the collagen fibers in the perimysium disappeared and the fibers were almost straightened. Additionally, the interconnection of the collagen fibers became loosened and interstice was presented among the fibers. At the 4th week of consolidation, the restoration to the original crimped structure was not completed. When the lengthening ratio was increased to 20%, the collagen fibers were straightened completely. This condition remained unchanged throughout all 4 weeks. The passive range of joint motion was reduced dramatically in the regime of 2 mm/d distraction. CONCLUSION: The ultrastructure of perimysium and the passive range of joint motion in the regime of 1mm/d lengthening shows the condition closest to the normal ones. The regime of 2 mm/d lengthening may cause an apparent change in the ultrastructure of perimysium and passive range of joint motion.

Maturation State and Matrix Microstructure Regulate Interstitial Cell Migration in Dense Connective Tissues.

Few regenerative approaches exist for the treatment of injuries to adult dense connective tissues. Compared to fetal tissues, adult connective tissues are hypocellular and show limited healing after injury. We hypothesized that robust repair can occur in fetal tissues with an immature extracellular matrix (ECM) that is conducive to cell migration, and that this process fails in adults due to the biophysical barriers imposed by the mature ECM. Using the knee meniscus as a platform, we evaluated the evolving micromechanics and microstructure of fetal and adult tissues, and interrogated the interstitial migratory capacity of adult meniscal cells through fetal and adult tissue microenvironments with or without partial enzymatic digestion. To integrate our findings, a computational model was implemented to determine how changing biophysical parameters impact cell migration through these dense networks. Our results show that the micromechanics and microstructure of the adult meniscus ECM sterically hinder cell mobility, and that modulation of these ECM attributes via an exogenous matrix-degrading enzyme permits migration through this otherwise impenetrable network. By addressing the inherent limitations to repair imposed by the mature ECM, these studies may define new clinical strategies to promote repair of damaged dense connective tissues in adults.