Repair Site Research Articles

SCOPING: A Pilot Study Exploring the Role of A Series of Clinical Observational Parameters as Indicators of Nerve Regeneration.

Following the repair of a mixed peripheral nerve, functional recovery requires successful nerve regeneration across the repair site and, eventually, reinnervation of distal targets. Reliably determining a failing nerve repair so that revision may be performed before irreversible muscle atrophy remains a challenge in peripheral nerve surgery. This study aimed to ascertain whether any commonly used clinical examination tests during surveillance after nerve repair can detect a failing repair and prompt earlier salvage intervention. A prospective observational cohort study was performed to evaluate commonly used clinical determinants of neuron regeneration that may provide early surrogate recovery measures. Sequential cutaneous thermography was used to identify temperature differences between denervated and normal skin in the hand operated on, with the contralateral hand as a control. Six out of nine patients completed between 6 and 18 months of follow-up. Tinel sign progression was observed in all subjects. Tinel progression rate was associated with motor and sensory Medical Research Council grade. The delta temperature was calculated to document the size and direction of any temperature differentials in the hand detected by thermography, but we did not have sufficient data to calculate any correlations with motor and sensory Medical Research Council grade. Specifically, the progression of Tinel sign is associated with recovery measured by progression of the British Medical Research Council motor and sensory grades. The use of thermographic imaging demonstrates that there is a difference in temperature between an injured and noninjured nerve. Future studies could investigate to what extent thermographic imaging predicts final nerve repair outcomes.

Effect of magnetic microbeads on sustained and targeted delivery of transforming growth factor-beta-1 for rotator cuff healing in a rat rotator cuff repair model

Structural failure is a well-established complication of rotator cuff repair procedures. To evaluate the effect of magnetic microbeads, designed for precise drug delivery via magnetic force, on sustained transforming growth factor-beta-1 (TGF-β1) release and rotator cuff healing in a rat rotator cuff repair model. TGF-β1 laden microbeads were prepared, and baseline in vitro experiments included the magnetization of the microbeads and TGF-β1 release tests. In an in vivo experiment using a rat rotator cuff repair model on both shoulders, 72 rats were randomly assigned to three groups (24 per group): group A, conventional repair; group B, repair with and simple TGF-β1 injection; and group C, repair with magnet insertion into the humeral head and TGF-β1 laden microbead injection. Delivery of TGF-β1 was evaluated at 1 and 7 days after the intervention using PCR, Western blot, and immunohistochemistry. At 6 weeks post-intervention, rotator cuff healing was assessed using biomechanical and histological analysis. The in vitro experiments confirmed the magnetization property of the microbeads and sustained delivery of TGF-β1 for up to 10 days. No difference in the TGF-β1 expression was found at day 1 in vivo. However, at day 7, group C exhibited a significantly elevated expression of TGF-β1 in both PCR and Western blot analyses compared to groups A and B (all P < 0.05). Immunohistochemical analysis revealed a higher expression of TGF-β1 at the repair site in group C on day 7. At 6 weeks, biomechanical analysis demonstrated a significantly higher ultimate failure load in group C than in groups A and B (P < 0.05) and greater stiffness than in group A (P = 0.045). In addition, histological analysis showed denser and more regular collagen fibers with complete continuity to the bone in group C than in groups A and B, a statistically significant difference according to the semi-quantitative scoring system (all P < 0.05). The use of the TGF-β1 laden magnetic microbeads demonstrated sustained delivery of TGF-β1 to the repair site, improving rotator cuff healing.

Biohacking Nerve Repair: Novel Biomaterials, Local Drug Delivery, Electrical Stimulation, and Allografts to Aid Surgical Repair.

The regenerative capacity of the peripheral nervous system is limited, and peripheral nerve injuries often result in incomplete healing and poor outcomes even after repair. Transection injuries that induce a nerve gap necessitate microsurgical intervention; however, even the current gold standard of repair, autologous nerve graft, frequently results in poor functional recovery. Several interventions have been developed to augment the surgical repair of peripheral nerves, and the application of functional biomaterials, local delivery of bioactive substances, electrical stimulation, and allografts are among the most promising approaches to enhance innate healing across a nerve gap. Biocompatible polymers with optimized degradation rates, topographic features, and other functions provided by their composition have been incorporated into novel nerve conduits (NCs). Many of these allow for the delivery of drugs, neurotrophic factors, and whole cells locally to nerve repair sites, mitigating adverse effects that limit their systemic use. The electrical stimulation of repaired nerves in the perioperative period has shown benefits to healing and recovery in human trials, and novel biomaterials to enhance these effects show promise in preclinical models. The use of acellular nerve allografts (ANAs) circumvents the morbidity of donor nerve harvest necessitated by the use of autografts, and improvements in tissue-processing techniques may allow for more readily available and cost-effective options. Each of these interventions aid in neural regeneration after repair when applied independently, and their differing forms, benefits, and methods of application present ample opportunity for synergistic effects when applied in combination.

Reprogramming macrophages with R848-loaded artificial protocells to modulate skin and skeletal wound healing.

After tissue injury, inflammatory cells are rapidly recruited to the wound where they clear microbes and other debris, and coordinate the behaviour of other cell lineages at the repair site in both positive and negative ways. In this study, we take advantage of the translucency and genetic tractability of zebrafish to evaluate the feasibility of reprogramming innate immune cells in vivo with cargo-loaded protocells and investigate how this alters the inflammatory response in the context of skin and skeletal repair. Using live imaging, we show that protocells loaded with R848 cargo (which targets TLR7 and TLR8 signalling), are engulfed by macrophages resulting in their switching to a pro-inflammatory phenotype and altering their regulation of angiogenesis, collagen deposition and re-epithelialization during skin wound healing, as well as dampening osteoblast and osteoclast recruitment and bone mineralization during fracture repair. For infected skin wounds, R848-reprogrammed macrophages exhibited enhanced bactericidal activities leading to improved healing. We replicated our zebrafish studies in cultured human macrophages, and showed that R848-loaded protocells similarly reprogramme human cells, indicating how this strategy might be used to modulate wound inflammation in the clinic.

"Off-pore" nucleoporins relocalize heterochromatic breaks through phase separation.

Phase separation forms membraneless compartments in the nuclei, including by establishing heterochromatin "domains" and repair foci. Pericentromeric heterochromatin mostly comprises repeated sequences prone to aberrant recombination, and "safe" homologous recombination (HR) repair of these sequences requires the movement of repair sites to the nuclear periphery before Rad51 recruitment and strand invasion. How this mobilization initiates is unknown, and the contribution of phase separation to these dynamics is unclear. Here, we show that Nup98 nucleoporin is recruited to heterochromatic repair sites before relocalization through Sec13 or Nup88 nucleoporins, and downstream from the Smc5/6 complex and SUMOylation. Remarkably, the phase separation properties of Nup98 are required and sufficient to mobilize repair sites and exclude Rad51, thus preventing aberrant recombination while promoting HR repair. Disrupting this pathway results in heterochromatin repair defects and widespread chromosome rearrangements, revealing a novel "off-pore" role for nucleoporins and phase separation in nuclear dynamics and genome integrity in a multicellular eukaryote.

Artificial dermal repair for larger finger pulp defects: Satisfactory coverage with limitations in sensation and inevitable scar formation

BackgroundThis prospective study aimed to evaluate the outcomes of the use of dermal templates for lengthy volar soft tissue defects (1.5–4 cm) in the fingers. MethodsThe volar soft tissue defects of 15 patients (19 fingers) were treated with Lando dermal template coverage between June 2022 and November 2022. We evaluated sensory recovery, scar formation, and overall appearance of the repair site at an average of 13 months (range, 12–17 months) of follow-up. ResultsThe defect healed in all cases. We found an average static 2-point discrimination of 7 mm (range 4 to 14 mm). Scar formation was evident in all cases. The repair did not restore the bulkiness of the volar finger, especially in the finger with the bony exposure. Nail deformities and joint contracture were observed in some cases. ConclusionDermal template repair does not restore normal sensation and inevitably leads to scar formation when the defect is longer (>1.5 cm). Bulkiness of the volar finger is not restored in most patients, especially when there was bone or tendon exposure in the initial wound site.

Human amniotic membrane modulates collagen production and deposition in vitro

Pathological fibrosis is a significant complication of surgical procedures resulting from the accumulation of excess collagen at the site of repair which can compromise the tissue architecture and severely impede the function of the affected tissue. Few prophylactic treatments exist to counteract this process; however, the use of amniotic membrane allografts has demonstrated promising clinical outcomes. This study aimed to identify the underlying mechanism of action by utilizing relevant models that accurately represent the pathophysiology of the disease state. This study employed a pro-fibrotic in vitro system using TGFβ1 stimulation and macromolecular crowding techniques to evaluate the mechanism by which amniotic membrane allografts regulate collagen biosynthesis and deposition. Following treatment with dehydrated human amnion chorion membrane (DHACM), subsequent RNA sequencing and functional enrichment with Reactome pathway analysis indicated that amniotic membranes are indeed capable of regulating genes associated with the composition and function of the extracellular matrix. Furthermore, macromolecular crowding was used in vitro to expand the evaluation to include both the effects of DHACM and a lyophilized human amnion/chorion membrane (LHACM). DHACM and LHACM regulate the TGFβ pathway and myofibroblast differentiation. Additionally, both DHACM and LHACM modulate the production, secretion, and deposition of collagen type I, a primary target for pathological fibrosis. These observations support the hypothesis that amniotic membranes may interrupt pathological fibrosis by regulating collagen biosynthesis and associated pathways.

Effect of Heparin on Post-Operative Ultrasonographic Changes in Flexor Digitorum Profundus Tendon Trauma Of The Hand

Abstract Background Flexor tendon injuries especially zone II are a challenging problem for both surgeons and patients as they need careful post-operative early physiotherapy to decrease adhesions and improve gliding which carry risk of early tendon rupture. Many drugs were tested for their role in decreasing paratendinous adhesions and enhance clinical outcome, this study by ultrasound examination test effect of intraoperative addition of heparin in limiting paratendinous adhesions and improving clinical outcome. Aim of the Work to evaluate the effect of intraoperative heparin addition in preventing postoperative adhesions and on clinical outcome. Patients and Methods This clinical trial study included 21 patients with 31 surgically repaired zone II flexor digitorum profundus tendons. The 21 Patients were divided randomly into two groups, group A (study group) with heparin injection during surgical repair and group B (control group) without heparin injection, with a total number of eleven patients in group I and ten patients in group II. Results There was no statistically significant difference between the two groups in tendon margins, gliding or granulation tissue severity, which can support why it does not affect clinical outcome. There was no statistically significant relation between the heparin injection and tenosynovitis although heparin is known for its anti-inflammatory effect. Tendon re rupture was more presented in heparin injected group yet not of statistical significance. Conclusion The intraoperative heparin injection at repair site didn’t show any significance in enhancing clinical outcome or in limiting paratendinous adhesions. Although it wasn’t of statistical significant but tendon re-rupture was more seen in cases managed with heparin injection group so heparin injection is not recommended in treatment such cases yet further investigations are needed.

Poster 303: Outcomes Following Repair of Radial Meniscus Tears Compared to Bucket Handle Meniscus Tears

Objectives: Preserving the meniscus has become a priority in managing meniscal tears with advancement of meniscus repair techniques. Meniscal repair, as opposed to partial meniscectomy, reduces risk of development and progression of knee osteoarthritis. Radial meniscus tears have traditionally been associated with a poor prognosis because they occur perpendicular to circumferential meniscal fibers, compromising hoop tension. Advances in surgical technique and biologic augmentation have facilitated repair of these complex injuries. The purpose of this study was to compare post-operative complication and surgical revision rates in patients who underwent repair of a radial meniscus tear versus bucket-handle meniscus tear. We hypothesized the outcomes of repair of radial meniscus tear would be similar to a matched group of patients who underwent repair of a bucket handle meniscus tear. Methods: A retrospective study was performed to identify patients who underwent repair of radial meniscus tear. Chart review was performed for 1506 patients who underwent meniscus repair from 2012 to 2019, and demographic information, type of meniscus tear, concomitant ACL reconstruction, post-operative complications, repeat surgeries, and failure at the repair site were detailed in a database. Patients who underwent repair of a radial tear were matched with patients who underwent repair of a bucket-handle tear based on sex, age (within 5 years), BMI (within 5 kg/m2), meniscus laterality, and concomitant ACL reconstruction. Isolated meniscus repairs were augmented with platelet rich plasma (PRP). Results: Fifty patients (age, 31.8 ± 15.2 years; BMI, 30.2 ± 6.4 kg/m2) were identified who underwent a radial meniscus tear repair. Of these patients, 16 (32.0%) were female and 23 (46.0%) underwent concomitant ACL reconstruction. Complications including recurrent swelling, stiffness, persistent pain, and repeat injury were reported in 15 patients (30.0%). Six patients underwent repeat surgery (12.0%). Four repeat surgical patients, who had previously undergone meniscus repair and concomitant ACL reconstruction, were found to have an intact radial repair at the time of second surgery, and underwent repeat surgery for a reason unrelated to the radial tear repair (e.g. cyclops lesion, synovectomy, new meniscus tear). Two patients had a radial tear repair failure that required surgical revision (4.0%). Radial tear repair patients who underwent concomitant ACL reconstruction differed significantly from those who did not only in age (ACL group, 26.0 ± 10.9 y; non-ACL group, 36.6 ± 16.7 y; p = 0.03). There were no significant differences in post-operative complications, repeat surgeries, or failures between the radial and bucket-handle tear repair patients. Conclusions: Repair of radial meniscus tears with contemporary techniques and biological enhancement with either ACL reconstruction or PRP can be expected to have similar outcomes to repairs of bucket handle meniscus tears.

DNA N-glycosylases Ogg1 and EndoIII as components of base excision repair in Plasmodium falciparum organelles

The integrity of genomes of the two crucial organelles of the malaria parasite — an apicoplast and mitochondrion in each cell − must be maintained by DNA repair mediated by proteins targeted to these compartments. We explored the localisation and function of Plasmodium falciparum base excision repair (BER) DNA N-glycosylase homologs PfEndoIII and PfOgg1. These N-glycosylases would putatively recognise DNA lesions prior to the action of apurinic/apyrimidinic (AP)-endonucleases. Both Ape1 and Apn1 endonucleases have earlier been shown to function solely in the parasite mitochondrion. Immunofluorescence localisation showed that PfEndoIII was exclusively mitochondrial. PfOgg1 was not seen clearly in mitochondria when expressed as a PfOgg1leader-GFP fusion, although chromatin immunoprecipitation assays showed that it could interact with both mitochondrial and apicoplast DNA. Recombinant PfEndoIII functioned as a DNA N-glycosylase as well as an AP-lyase on thymine glycol (Tg) lesions. We further studied the importance of Ogg1 in the malaria life cycle using reverse genetic approaches in Plasmodium berghei. Targeted disruption of PbOgg1 resulted in loss of 8-oxo-G specific DNA glycosylase/lyase activity. PbOgg1 knockout did not affect blood, mosquito or liver stage development but caused reduced blood stage infection after inoculation of sporozoites in mice. A significant reduction in erythrocyte infectivity by PbOgg1 knockout hepatic merozoites was also observed, thus showing that PbOgg1 ensures smooth transition from liver to blood stage infection. Our results strengthen the view that the Plasmodium mitochondrial genome is an important site for DNA repair by the BER pathway.

Paper 14: Evaluation of Outcomes at Mean 2.75 years after Repair of Lateral Meniscus Oblique Radial Tears during ACL Reconstruction

Objectives: Lateral meniscus oblique radial tears (LMORTs) commonly occur in the setting of anterior cruciate ligament (ACL) rupture. Despite publications pertaining to the prevalence, biomechanics, and surgical repair techniques of LMORTs, studies reporting outcomes following LMORT repair are lacking. The purpose of this study was to examine clinical and patient-reported outcomes following the surgical repair of LMORTs during ACL reconstruction. Methods: A retrospective chart review was conducted on 845 patients that underwent a meniscus repair at a single institution between 2017 and 2019. Operative reports, procedure notes, and operative images were manually reviewed to identify LMORTs. Subsequent knee surgery, meniscus repair failure, and postoperative complications were also extracted during the chart review. Postoperative complications were defined as reinjury, pain, stiffness, recurrent swelling, weakness, instability, or superficial wound infections. Patients were contacted postoperatively for evaluation of patient reported outcomes including the Knee Injury and Osteoarthritis Outcome Score (KOOS), Marx Activity Rating Scale (MARS), and Visual Analog Scale (VAS). Results: Twenty-five patients (68% male) were identified who underwent repair of an LMORT in the same setting as an ACL reconstruction during the study period. Mean age was 21.1 ± 4.6 years old, and the mean body mass index was 26.9 ± 5.1 kg/m2. Mean follow-up was 33.1 ± 25.7 months. There were no reported failures of the LMORT repair. Postoperative complications were reported in 9 patients (36%). Seven of these patients underwent repeat arthroscopy of the index knee for stiffness, pain, and/or repeat injury. However, of the patients who had repeat arthroscopy at the same institution (6 patients), all demonstrated complete healing of the LMORT repair site during arthroscopic evaluation. For patients completing patient-reported outcome measures, there was a minimum follow-up period of 43 months from the initial date of surgery. The mean KOOS, MARS, and VAS were 86.3 ± 8.1, 6.7 ± 4.2, and 2.0 ± 1.3, respectively. Conclusions: Surgical repair of LMORTs results in low failure risk, low complication rates, and favorable patient-reported outcome measures. Further work is needed to evaluate for differences in outcomes between meniscus repair versus partial meniscectomy versus observation of these LMORT lesions.

Mesenchymal Stromal Cells for the Enhancement of Surgical Flexor Tendon Repair in Animal Models: A Systematic Review and Meta-Analysis.

Flexor tendon lacerations are primarily treated by surgical repair. Limited intrinsic healing ability means the repair site can remain weak. Furthermore, adhesion formation may reduce range of motion post-operatively. Mesenchymal stromal cells (MSCs) have been trialled for repair and regeneration of multiple musculoskeletal structures. Our goal was to determine the efficacy of MSCs in enhancing the biomechanical properties of surgically repaired flexor tendons. A PRISMA systematic review was conducted using four databases (PubMed, Ovid, Web of Science, and CINAHL) to identify studies using MSCs to augment surgical repair of flexor tendon injuries in animals compared to surgical repair alone. Nine studies were included, which investigated either bone marrow- or adipose-derived MSCs. Results of biomechanical testing were extracted and meta-analyses were performed regarding the maximum load, friction and properties relating to viscoelastic behaviour. There was no significant difference in maximum load at final follow-up. However, friction, a surrogate measure of adhesions, was significantly reduced following the application of MSCs (p = 0.04). Other properties showed variable results and dissipation of the therapeutic benefits of MSCs over time. In conclusion, MSCs reduce adhesion formation following tendon injury. This may result from their immunomodulatory function, dampening the inflammatory response. However, this may come at the cost of favourable healing which will restore the tendon's viscoelastic properties. The short duration of some improvements may reflect MSCs' limited survival or poor retention. Further investigation is needed to clarify the effect of MSC therapy and optimise its duration of action.

Left ventricular unloading therapy using Impella 5.5 after emergency surgery for acute myocardial infarction mechanical complication: a case report

BackgroundFollowing an acute myocardial infarction (AMI), surgery for left ventricular free wall rupture (LVFWR) and ventricular septal rupture (VSR) has a high in-hospital mortality rate, which has not improved significantly over time. Unloading the LV is critical to preventing excessive stress on the repair site and avoiding problems such as bleeding, leaks, patch dehiscence, and recurrence of LVFWR and VSR because the tissue is so fragile. We present two cases of patients who used Impella 5.5 for LV unloading following emergency surgery for AMI mechanical complications.Case presentationA 76-year-old male STEMI patient underwent fibrinolysis of the distal right coronary artery. Three days later, he passed out and went into shock. Echocardiography revealed a cardiac tamponade. We found an oozing-type LVFWR on the posterolateral wall and treated it with a non-suture technique using TachoSil. Before the patient was taken off CPB, Impella 5.5 was inserted into the LV via a 10 mm synthetic graft connected to the right axillary artery. We kept the flow rate above 4.0 to 4.5 L/min until POD 3 to reduce LV wall tension while minimizing pulsatility. On POD 6, we weaned the patient from Impella 5.5. A postoperative cardiac CT scan showed no contrast leakage from the LV. However, a cerebral hemorrhage on POD 4 during heparin administration complicated his hospitalization. Case 2: A diagnosis of cardiogenic shock caused by STEMI occurred in an 84-year-old male patient, who underwent PCI of the LAD with IABP support. Three days after PCI, echocardiography revealed VSR, and the patient underwent emergency VSR repair with two separate patches and BioGlue applied to the suture line between them. Before weaning from CPB, we implanted Impella 5.5 in the LV and added venoarterial extracorporeal membrane oxygenation (VA-ECMO) support for right heart failure. The postoperative echocardiography revealed no residual shunt.ConclusionsPatients undergoing emergency surgery for mechanical complications of AMI may find Impella 5.5 to be an effective tool for LV unloading. The use of VA-ECMO in conjunction with Impella may be an effective strategy for managing VSR associated with concurrent right-sided heart failure.

Polyamory in Black: A Companion Justification for Minimal Marriage

ABSTRACTA number of Black writers have cast Black marriage in a state of emergency – Black folks are not getting (or staying) married like they used to. Yet in seeking to address the Black marriage problem many have left marriage's ‘monogamous‐only’ condition unexamined. In this article, I take a different approach. I draw on a long‐standing prevalence of de facto non‐monogamy among those marked Black and argue that the numerical constraint making marriage between two people violates equal treatment. To make the case, I show how anti‐non‐monogamy attitudes have been racialized in ways that are expressive of anti‐Blackness. In my view, the effects of this racialization include ongoing and disproportionate impacts on an already burdened group – Black polyamorists. A failure to reform the monogamous‐only condition of marriage tacitly endorses anti‐non‐monogamous attitudes of the past where Black intimate relationships were thought inferior and therefore deserving of an inferior social standing. Finally, I look to an account of minimal marriage as a site of possibility for establishing a marriage institution that is more just in relation to equal treatment and a site of repair for racialized non‐monogamists whose historical denial to accessing marriage has had the effect of accumulated social and political disadvantage.

Photosealed Neurorrhaphy Using Autologous Tissue.

Photochemical sealing of a nerve wrap over the repair site isolates and optimizes the regenerating nerve microenvironment. To facilitate clinical adoption of the technology, we investigated photosealed autologous tissue in a rodent sciatic nerve transection and repair model. Rats underwent transection of the sciatic nerve with repair performed in three groups: standard microsurgical neurorrhaphy (SN) and photochemical sealing with a crosslinked human amnion (xHAM) or autologous vein. Functional recovery was assessed at four-week intervals using footprint analysis. Gastrocnemius muscle mass preservation, histology, and nerve histomorphometry were evaluated at 120 days. Nerves treated with a PTB-sealed autologous vein improved functional recovery at 120 days although the comparison between groups was not significantly different (SN: -58.4 +/- 10.9; XHAM: -57.9 +/- 8.7; Vein: -52.4 +/- 17.1). Good muscle mass preservation was observed in all groups, with no statistical differences between groups (SN: 69 +/- 7%; XHAM: 70 +/- 7%; Vein: 70 +/- 7%). Histomorphometry showed good axonal regeneration in all repair techniques. These results demonstrate that peripheral nerve repair using photosealed autologous veins produced regeneration at least equivalent to current gold-standard microsurgery. The use of autologous veins removes costs and foreign body concerns and would be readily available during surgery. This study illustrates a new repair method that could restore normal endoneurial homeostasis with minimal trauma following severe nerve injury.

ATTACHMENT WITH SUTURE VIA BONE TUNNELS IS COMPARABLE BIOMECHANICALLY TO SINGLE-ROW ANCHOR SUTURE FOR REATTACHMENT OF ACHILLES TENDON TO BONE

Insertional Achilles tendinitis with considerable degeneration that failed non-operative treatment typically requires tendon debridement and reattachment to bone. It is common practice for tendons to be reattached back with anchor sutures, but this poses a challenge to patients who are not able to afford them. Bony anchorage of tendons may be performed by passing sutures through tunnels, but the strength of repair compared to by using anchors is not known. We investigated the load at clinical and catastrophic failure of these two methods of reattachment. Sixteen paired Achilles tendons along with the calcaneus were harvested from eight fresh frozen cadavers. Paired randomization was done. For the anchor suture group, two 5’0 anchors with polyethylene #2 sutures were used for reattachment whereas for the suture only group, tendons were reattached to bone using braided polyester #2 sutures via two bony tunnels. All samples were mounted on a materials testing system and preloaded at 50N for 60sec before load to failure at a rate of 1mm/sec. With the assumption that preloading has removed tendon crimp and any subsequent extension is a result of gapping at the repair site, loads at 5mm, 10mm, 15mm, and 20mm of extension were noted as well as the maximal load at failure. We found higher loads were needed to cause an extension of 5 to 20mm in the suture only group compared to the anchor suture group but these data were not significant. On the other hand, the anchor suture group required higher loads before catastrophic failure occurred compared to the suture only group, but this again is not significant. We conclude that suture only reattachment of the Achilles tendon is comparable in strength with anchor suture reattachment, and this method of reattachment can be considered for patients who do not have access to anchor sutures.

Review on Repair and Rehabilitation of Cold Storage

Abstract: The purpose of the project is to gain fundamental and practical understanding on concrete repair and rehabilitation of the structures. Large number of reinforced concrete (RC) structure are deteriorating, often prematurely, and need remedial measures to reinstate their safety and/or serviceability. Consequently, the need for repair and protection has grown considerably in recent years. While costs associated with repair of deteriorating concrete structures can be substantial, costs resulting from poorly designed or executed repairs may be even higher. Repair methods need to be designed with consideration for the anticipated or desired remaining service life of the structure. A distinction must be made between repairs intended to stop deterioration fully and those merely aimed at slowing down deterioration processes for a limited period of time. Then the respective repairs will be studied and classified into cracks, corrosion of concrete reinforcement, seepage and deterioration of surface coating. Detailed study will be done on the causes for each repair and a suitable rehabilitation method will be suggested for each repair site by comparing various methods. This paper presents review of literature available on the repair and rehabilitation of cold storage and presented a complied review report.

Meniscal Repair with ArthroZheal® an Autologous Bioactive Fibrin Scaffold. A New Technique and Treatment Option.

Injuries of the meniscus often lead to changes in joint biomechanics, which affect the load distribution and contact stresses. The menisci consist of a peripheral vascular region (red zone) and an inner avascular region (white zone). The blood supply plays an important role in the healing of meniscal tears. Surgical treatment of such lesions includes meniscectomy/meniscoplasty and repair, depending on the type of injury, where "meniscoplasty" refers to the treatment modality that occurs under coblation. The application of Autologous Bioactive Matrix (ABM) has been shown to promote healing in such lesions. In addition, a special type of PRF (ArthroZheal®, Vivostat A/S, Allerød, Denmark) has been demonstrated to have healing effects in extracellular matrix synthesis and cell proliferation, as well as regenerative and remodeling effects. This autologous product can be applied directly at the meniscal repair site. We performed a prospective study on meniscus repair with ArthroZheal® alone (plus meniscoplasty) and ArthroZheal® together with an all-inside suturing technique using the STAR AccurFix Meniscal Repair Device system (STAR Sports Medicine, Beijing, China), depending on the type and the site of the lesion. One hundred twenty knees (110 patients) were identified through the use of clinical examination and MRI scan. The study took place between January 2023 and August 2023. Two groups were created: GROUP A was treated only with ArthroZheal®(plus meniscoplasty) and GROUP B was treated with a combination of ArthroZheal® and an all-inside suturing technique (STAR AccurFix). Pre- and postoperative grading was performed with the International Knee Documentation Committee (IKDC) score and the Tegner Activity Level Scale (Tegner Score). The results with both treatment methods were excellent and meniscus restoration has been documented on MRIs conducted 6 months post-op. In 15 patients, 2nd-look arthroscopy was performed through a nanoscope on an outpatient basis, and showed meniscal healing and remodeling. Tegner scores and IKDC scores in both groups showed significant improvement. Meniscal repair should be performed at all costs to maintain meniscal integrity and prevent long-term degenerative changes. New treatment methods include orthobiologics and all-inside suturing techniques. The main idea is to apply an autologous biological scaffold which is able to carry cells into the meniscal lesion and to allow their differentiation, proliferation, and extracellular matrix synthesis to produce a meniscal-like tissue. Our results suggest that the application of autologous ABM (ArthroZheal®) for the treatment of such lesions by means of dry arthroscopy results in better MRI, pain management and functional results at 3 months post-op, and these improvements can persist for up to 6 months.

Inside-out repair of complex tears in the posterior horn of the lateral meniscus

All-inside meniscus devices are preferred over inside-out sutures for complex tears in the posterior horn of the lateral meniscus due to the ease of use, avoidance of additional skin incisions, and reduced surgical time. However, inside-out sutures have the advantages of being less traumatic due to smaller diameter needles, better healing rate, and less chance of injuries to posterior neurovascular structures due to direct visualization and protection. To the author’s knowledge, the inside-out repair technique has been described only for vertical tears and not for complex tears in the posterior horn of the lateral meniscus. This video describes the technique of repairing complex lateral meniscus tears with inside-out sutures using various suture configurations. The lateral meniscus tear pattern is identified. A posterolateral safety incision is made, and a retractor is placed posterior to the capsule. The popliteal vein is identified at this step and kept under visualization to avoid injury. Meniscal repair configurations such as “H,” “X,” and “A” patterns and simple vertical or horizontal sutures are planned according to the tear pattern. Sutures are passed using inside-out meniscal sutures, 18G spinal needle, self-retrieving suture devices or a combination of those, and tied over the capsule using sliding knots while the repair site is arthroscopically visualized.

DNA lesion bypass and the stochastic dynamics of transcription-coupled repair

DNA base damage is a major source of oncogenic mutations and disruption to gene expression. The stalling of RNA polymerase II (RNAP) at sites of DNA damage and the subsequent triggering of repair processes have major roles in shaping the genome-wide distribution of mutations, clearing barriers to transcription, and minimizing the production of miscoded gene products. Despite its importance for genetic integrity, key mechanistic features of this transcription-coupled repair (TCR) process are controversial or unknown. Here, we exploited a well-powered in vivo mammalian model system to explore the mechanistic properties and parameters of TCR for alkylation damage at fine spatial resolution and with discrimination of the damaged DNA strand. For rigorous interpretation, a generalizable mathematical model of DNA damage and TCR was developed. Fitting experimental data to the model and simulation revealed that RNA polymerases frequently bypass lesions without triggering repair, indicating that small alkylation adducts are unlikely to be an efficient barrier to gene expression. Following a burst of damage, the efficiency of transcription-coupled repair gradually decays through gene bodies with implications for the occurrence and accurate inference of driver mutations in cancer. The reinitation of transcription from the repair site is not a general feature of transcription-coupled repair, and the observed data is consistent with reinitiation never taking place. Collectively, these results reveal how the directional but stochastic activity of TCR shapes the distribution of mutations following DNA damage.