Graft Stability Research Articles

The buried knot technique for all inside graft link preparation leads to superior biomechanical graft link stability

The aim of this study was to measure and compare the biomechanical properties of two different graft link preparation techniques for anterior cruciate ligament reconstruction. We hypothesised that there would be differences in elongation, load at failure and failure mode due to the different graft link preparation techniques. Thirty fresh-frozen anatomical specimen knees were used. Both tendons (semitendinosus and gracilis) were harvested and randomly assigned to two groups. Graft links prepared with a continuous loop technique were allocated to group 1, whereas those prepared with a buried-knot technique were allocated to group 2. The mechanical properties of both techniques were measured. A mean load to failure of 731 N and an overall graft elongation of 6 mm was found in the continuous loop group. In the buried-knot group, a higher load to failure (848 N) and a lower mean overall elongation (5 mm) was found. The buried-knot technique showed better results with significantly higher load to failure and significantly less elongation compared to the continuous loop technique. It is essential in clinical practice to choose the most accurate technique for graft link preparation to ensure graft stability, especially in the early phase of recovery.

Myringoplasty outcome. Five-year experience at a tertiary teaching hospital.

Objectives:To assess the outcome of a myringoplasty procedure during a 5-year period at a tertiary teaching hospital in Abha, Kingdom of Saudi Arabia.Methods:All patients with chronic suppurative otitis media (CSOM) who underwent elective myringoplasty between August 2012 and February 2018 were included in the study. Patients were investigated preoperatively and postoperatively by pure tone audiometry (PTA). The patients’ demographic data were collected together with the surgical outcome. Postoperatively, patients were followed at the first week, at 6 weeks and then every 3 months, thereafter for one year.Results:A total of 67 myringoplasty procedures were performed during the period of study. There were 41 females and 26 males, and they had an age range of 16-60 years and a mean age of 32.37±12.95 years. Preoperative PTA indicated that 58 (86.6%) patients had a hearing gap >20 dB. However, after surgery, only 9 (13.4%) patients remained with hearing gaps >20 dB. The success rate of graft stability at the end of one year was 94% with significant difference p=0.0001. However, one patient of the 4 patients with failed graft stability demonstrated graft atrophy, and the remaining 3 developed graft infection.Conclusion:Myringoplasty remains a useful technique for the management of CSOM. However, it depends on the surgeon’s skills and expertise and on the site of perforation. The success rate of myringoplasty in this study was comparable with that of the quoted literature.

Meniscal and Chondral Pathology Associated With Anterior Cruciate Ligament Injuries.

Anterior cruciate ligament (ACL) ruptures are commonly associated with meniscal and articular cartilage injuries, and the presence of these defects influences both short- and long-term outcomes. Multiple variables are predictive of this pathology including time from injury, age, and sex. Revision ACL reconstructions demonstrate higher rates of chondral injury than primary reconstructions. Menisci are important secondary stabilizers of the knee in the setting of ACL deficiency, and specific tear types are more consistently associated with ACL injury. Successful outcomes with multiple treatment options for meniscal tears in conjunction with ACL reconstruction have been reported. Maintaining meniscal integrity may be protective of both joint surfaces and graft stability in the long term; however, clear treatment recommendations for tear subtypes remain ill defined. High-grade chondral defects have the most consistent and potentially largest negative effect on long-term patient-reported outcomes; however, optimal treatment is also controversial with successful results demonstrated with several modalities including benign neglect.

Natural killer cells as modulators of alloimmune responses.

Natural killer (NK) cells are effector cells of the innate immune system that can lyse target cells without prior sensitization and are important in host defense to virally infected and transformed cells. Although the concept of 'missing-self' would suggest NK cells could target foreign allografts, the prevailing dogma has been that NK cells are not active participants in the rejection of solid organ allografts. This review summarizes recent studies that challenge this conclusion and instead suggest NK cells are important in outcomes posttransplant. NK cells expressing specific cell surface receptors may promote graft damage and rejection. However, recent studies suggest some NK cell subsets have tolerogenic or immunoregulatory potential and promote graft stability, suggesting a dichotomous role for NK cells after transplant. Furthermore, NK cells respond to cells infected with cytomegalovirus and Epstein-Barr virus, and studies suggest some NK cells have immune memory. Our understanding of the role of NK cells posttransplant has evolved from 'no role' to the current idea that NK cells may have 'complex interactions' that impact graft outcomes. Additional studies, using cutting edge techniques to comprehensively analyze the phenotypic and functional subsets of NK cells in transplant recipients, are clearly necessary.

Connective Tissue Graft Stabilization by Subperiosteal Sling Suture for Periodontal Plastic Surgery Using the VISTA Approach

This report describes a minimally invasive surgical approach using the vestibular incision subperiosteal tunnel access and a suture called the subperiosteal sling (SPS) to stabilize the connective tissue graft (CTG) for periodontal plastic surgery. The SPS suture engages only the CTG and stabilizes the CTG against the tooth independent of the overlying tissue, which minimizes the risk of graft mobility caused by muscle movement.

Effect of grafted poly [2-methacryloyloxyethyl phosphorylcholine (MPC)] on tribological properties of ultra-high molecular weight polyethylene (UHMWPE)

2-methacryloyloxyethyl phosphorylcholine (MPC) polymers have good biocompatibility and hydrophilicity because the function of the phospholipid polar groups of MPC side-chain is similar to the natural articular cartilage. MPC has a potential application on surface modification of artificial joints. In this research, MPC was grafted on ultra-high molecular weight polyethylene (UHMWPE) by the photo-induced graft polymerization to form poly 2-methacryloyloxyethyl phosphorylcholine (PMPC) layer. The microstructure of PMPC layer was studied by Fourier-transform infrared (FT-IR) spectroscopy with attenuated total reflection (ATR) equipment, X-ray photoelectron spectroscopy (XPS). The surface wettability of PMPC layer was evaluated by the contact angle test. The wear resistance of MPC modified UHMWPE was evaluated by the wear test. The results show that the PMPC layer has a good lubricating effect and it can reduce the friction coefficient effectively. The benzophenone pretreatment time is an important factor in the graft stability of MPC.

Autologous Blood for Conjunctival Autograft Fixation in Primary Pterygium Surgery: A Systematic Review and Meta-analysis

The study aimed to perform a systematic review and meta-analysis of randomized controlled trials comparing the efficacy and complications of autologous blood versus using fibrin glue and surgical sutures for conjunctival autograft fixation in primary pterygium surgery. Systematic review with quantitative meta-analysis. Four authentic databases have been searched using relevant keywords. Eligible studies were obtained, and their data were extracted into an online form. Analysis was done using Review Manager for windows. Dichotomous outcomes were reported as risk ratio, while continuous data were reported as mean difference. Seven studies were included in the analysis. Most of the included studies were of moderate quality according to Cochrane Risk of Bias assessment tool. There was no difference between the three techniques in recurrence rates (Risk Ratio (RR) 0.80, 95% CI [0.45 to 1.44], p= 0.46). Graft retraction and displacement were more profound in the autologous blood group vs fibrin glue and suture groups (RR 3.22, 95% CI [1.48 to7.02], p= 0.003) and (RR 5.27, 95% CI [2.24 to 12.38], p> 0.001) respectively. In terms of operative time, fibrin glue took shorter while suturing took longer time compared to blood coagulum (Mean Difference (MD) =1.57, 95% CI [0.90, 2.25], p> 0.00001) and (MD -20.47, 95% CI [-38.05 to -2.88], p =0.02). Autologous blood for conjunctival autograft fixation in primary pterygium surgery was associated with lower graft stability than fibrin glue or sutures. However, it did not account for higher recurrence rates than the fibrin glue or sutures. Patient satisfaction and postoperative symptoms are relatively better in the blood coagulum group than the other techniques. The overall quality of evidence is low. Further well designed randomized controlled trials are still needed.

PTERYGIUM;

Objectives: To compare graft stability, patient discomfort and surgical time between autologus blood and sutures for autologus conjunctival graft adherence in pterygium surgery. Study Design: Prospective interventional study. Setting: Department of Ophthalmology, Pak Red Crescent Medical and Dental College, Dina Nath. Period: January 2017 to December 2017. Materials and Methods: Fifty eyes of fifty patients requiring pterygium surgery were enrolled. The patients were divided in two groups (A and B). Under peribulbar anesthesia pterygium was excised in all patients. Bare sclera was covered with conjuctival autograft using autologus blood as adhesive agentin Group A while in Group B conjuctival autograft was fixed with 10/0 Nylon sutures. The patients were examined postoperatively on day 1, day 7, day 14 and day 30. The groups were compared in terms of surgical time, graft displacement and patient discomfort. Results: Mean surgical time was (20.96 ±2.05 minutes) in Group A and (30.04±3.38 minutes) in Group B. There was nasal displacement of conjunctival autograft in 3 (12%) of patients on 1stpost-operative day in Group A whereas no graft displacement was seen in any case of Group B. Level of patient discomfort measured on visual analogue scale in Group A was (0.56 ± 0.92 on day 1, 0.40 ± 0.71 on day 7, 0.04 ± 0.20 on day 14 and 0 ± 0 on day 30). In Group B level of patient discomfort was (3.92 ± 1.12 on day1, 1.24 ± 1.09 on day 7, 0.12 ± 0.33 on day 14 and0 ±0 on day 30). Conclusions: The use of autologus blood to affix the conjuctival autograft in pterygium surgery is a reliable method. It is associated with less patient discomfort post operatively and requires shorter surgical time, as compared to conjunctival autograft with sutures.

Efficacy of Autologous Serum in Fixing Conjunctival Autografts of Various Sizes in Different Types and Grades of Pterygium.

Purpose:To evaluate the efficacy of autologous serum in fixing conjunctival autografts of various sizes in different grades and types of pterygium and to determine the largest successfully secured graft size.Methods:This prospective interventional study comprised 151 eyes of 151 patients belonging to age group of 21 to 64 years with different grades and types of primary and recurrent pterygium that underwent excision with inferior conjunctivo - limbal autograft secured with autologous serum. The autografts were measured with calipers and were grouped by size into three categories: Group A, small (5 × 5 mm); Group B, medium (5–7 × 5 mm); and Group C, large (>7 × 5 mm). The adhesive fixation power of autologous serum for the various conjunctival autograft sizes was determined for each group using the following criteria: graft stability, cosmetic appearance and complications in the immediate ( first week) and two-months postoperative follow-up visits. Descriptive statistical analysis was used to calculate the percentage frequency of the variables.Results:The groups A, B, and C included 48%, 22%, and 30% of the autografts, respectively. Overall, 93.34% of the grafts were stable with good cosmetic appearance. However, subconjunctival hemorrhage (36%), graft edema (36%) and graft retraction (13.5%) were the most common complications. The largest successfully fixed graft was 14 × 5 mm in size.Conclusion:Autologous serum is efficient in securing conjunctival autografts of various sizes with minimal complications and satisfactory results, including good cosmesis.

A detailed description and 16-year validation of a new suturing method for stabilizing connective tissue grafts at recipient sites for root coverage and gingival augmentation

Which are the different ways of stabilizing connective tissue grafts (CTGs) for root coverage and gingival augmentation by means of placement of sutures? There are various defined and undefined ways of stabilizing CTGs depending on experience and personal preferences. Most of the techniques profess use of absorbable sutures in separate interrupted fashion (sutures at the corners of the graft wherever possible). This paper describes a new suturing method, "the lingually-tied horizontal mattress contouring suture," for stabilization of CTGs with or without epithelialized collar at the recipient site, for use with papilla retention and sparing techniques to treat marginal tissue recessions. The suturing technique is described in detail. It can be indicated for good number of root coverage cases, with additional objectives of gingival augmentation, specifically developed for papilla sparing and papillary buccal de-epithelialization recipient site preparations. Over a period of last 16 years this suturing technique showed promising results in terms of graft stabilization and survival. The main advantage of this technique lies in the use of cost-effective nonabsorbable sutures that usually retain some amount of tension on the soft tissues longer. The primary objective of the suturing technique, per se, is to stabilize the CTG firmly along the contours of the root surface and to expedite a very close adaptation to the interdental soft tissues as well. The secondary objective of the article or publication is to disseminate the knowledge acquired through long periods of performance and observation for the benefit of the periodontal community as whole. Further validation is advocated.

Osteochondral Allograft Transplantation: Identifying the Biomechanical Impact of Using Shorter Grafts and Pulsatile Lavage on Graft Stability.

This study seeks to identify the ability of shorter osteochondral allografts (OCAs) to resist displacement/failure. Additionally, this study seeks to evaluate the effect of pulsatile lavage (PL) on the biomechanical stability of the OCA. Fifteen-millimeter diameter, human cadaveric, OCAs of 4, 7, and 10 mm in depth were harvested for comparison of resistance to compressive and tensile loads. For each group, seven specimens were subjected to tensile loads and three specimens subjected to compressive loads until failure (pullout or subsidence). An additional study group of 10 pulsatile-lavaged OCAs of 15 mm in diameter and 7 mm in depth were introduced for comparison to the original 7 mm depth OCA group. The average tensile forces for failure for the 4, 7, and 10 mm plugs were 23.74, 199.57, and 197.69 N, respectively (p = 1.5 × 10-5). After post hoc analysis of the tensile groups, significant differences in the mean tensile force to failure were appreciated between the 4 and 7 mm groups (p = 4.12 × 10-5) and the 4 and 10 mm groups (p = 1.78 × 10-5) but not between the 7 and 10 mm groups (p = 0.9601). There were no significant differences between the average tensile forces resulting in failure for the 7 mm and 7 mm PL groups (199.57 and 205.2 N, p = 0.90) or compressive forces to failure, respectively (733.6 and 656 N, p = 0.7062). For OCAs of 15 mm in diameter, a commonly used size in practice, plugs of 7 mm in depth showed comparable resistance to pull out and subsidence as 10 mm plugs and significantly better resistance to pull out than 4 mm grafts. PL of allografts prior to insertion did not take away from the structural integrity and stability of the plug.

Bone Graft Displacement After Maxillary Sinus Floor Augmentation With or Without Covering Barrier Membrane: A Retrospective Computed Tomographic Image Evaluation.

Scientific publications have recently found that bone graft quality and implant survival rates were not influenced by antrostomy membrane coverage during maxillary sinus floor augmentation with a lateral approach. The aim of this study was to evaluate the stability of the bone substitute after a maxillary sinus floor augmentation procedure with or without using a covering membrane. This retrospective study evaluated all patients who were enrolled between April 2016 and January 2017. The stability of the bone graft inside the sinus cavity as well at the level of the lateral bone window was assessed through preoperative and postoperative cone beam computed tomography images up to 6-month follow-up. The clinical postoperative morbidity was evaluated following a visual analog scale (VAS) protocol. Maxillary sinus floor augmentation with a lateral approach was performed in 41 patients. In 17 cases (10 women/7 men, mean age: 55.4 years), a barrier membrane was used to cover the lateral bone window (control group), and in 24 cases (13 women/11 men, mean age: 56.2 years), no membrane was used (test group). The bone graft dislodgement within the buccal mucosa at 6 months postoperative ranged from 0 to 12.2 mm (mean value: 3.8 ± 3.1 [standard deviation] mm) in the test group and from 0 to 2.3 mm (mean value: 0.5 ± 0.4 mm) in the control group. The postoperative pain and swelling complications were significantly more important for the test group (3.3 ± 1.4/4.3 ± 4.5, respectively) than for the control group (2.1 ± 0.9/2.7 ± 0.9). On the basis of this preliminary study, it appears that the use of a barrier membrane to cover the lateral bone window during maxillary sinus floor augmentation surgery with a lateral approach reduces the postoperative dislodgement of the bone graft throughout the sinus antrostomy and prevents the bone substitute particles penetrating within the buccal mucosa, which is related to postoperative morbidity.

Allograft Tendon Interposition Arthroplasty of the Hallux Metatarsophalangeal Joint: A Technique Guide and Literature Review.

The "anchovy" interpositional arthroplasty technique can be used as a salvage option for failed hallux rigidus procedures. The operative technique utilized by the senior author is described. Careful soft-tissue handling, meticulous joint space and graft preparation, and interposition graft stabilization using a bone tunnel and suture anchors are unique aspects of this technique, which in the authors' experience have contributed to improved outcomes. Current literature regarding indications and outcomes is limited and controversial. The proposed benefits of soft-tissue interposition arthroplasty of the hallux metatarsophalangeal joint for patients with prior failed implant arthroplasty are improved pain scores and preservation of range of motion. Level of Evidence: Level V, technique guide.

Cells, soluble factors and matrix harmonically play the concert of allograft integration.

Implantation of allograft tissues has massively grown over the last years, especially in the fields related to sports medicine. Beside the fact that often no autograft option exists, autograft related disadvantages as donor-site morbidity and prolonged operative time are drastically reduced with allograft tissues. Despite the well documented clinical success for bone allograft procedures, advances in tissue engineering raised the interest in meniscus, osteochondral and ligament/tendon allografts. Notably, their overall success rates are constantly higher than 80%, making them a valuable treatment option in orthopaedics, especially in knee surgery. Complications reported for allografting procedures are a small risk of disease transmission, immunologic rejection, and decreased biologic incorporation together with nonunion at the graft-host juncture and, rarely, massive allograft resorption. Although allografting is a successful procedure, improved techniques and biological knowledge to limit these pitfalls and maximize graft incorporation are needed. A basic understanding of the biologic processes that affect the donor-host interactions and eventual incorporation and remodelling of various allograft tissues is a fundamental prerequisite for their successful clinical use. Further, the importance of the interaction of immunologic factors with the biologic processes involved in allograft incorporation has yet to be fully dissected. Finally, new tissue engineering techniques and use of adjunctive growth factors, cell based and focused gene therapies may improve the quality and uniformity of clinical outcomes. The aim of this review is to shed light on the biology of meniscus, osteochondral and ligament/tendon allograft incorporation and how collection and storage techniques may affect graft stability and embodiment.Level of evidence V.

The influence of wound closure on graft stability‐ a comparison of different bone grafting techniques for the treatment of one‐wall horizontal bone defects

The influence of wound closure on graft stability‐ a comparison of different bone grafting techniques for the treatment of one‐wall horizontal bone defects

Influence of timing on horizontal stability of connective tissue grafts at single implants – a pilot study

Influence of timing on horizontal stability of connective tissue grafts at single implants – a pilot study

Dimensional stability of grafts using synthetic hydroxyapatite alone or with platelet rich fibrin on maxillary sinus lift. A clinical and tomographic study in humans

Dimensional stability of grafts using synthetic hydroxyapatite alone or with platelet rich fibrin on maxillary sinus lift. A clinical and tomographic study in humans

Modified transtibial versus anteromedial portal techniques for anterior cruciate ligament reconstruction, a comparative study.

PurposeThis study compared the accessory anteromedial portal (AAMP) and the modified transtibial technique (MTTT)” for single-bundle anterior cruciate ligament (ACL) reconstruction.Patients and methodsSixty active adult patients with ACL tear were randomly assigned into two equal groups who were treated surgically. One group was operated on using AAMP and the other group through MTTT. Both the groups had the same postoperative course and were followed for 1 year after surgery. The follow-up included Lysholm and International Knee Documentation Committee (IKDC) subjective knee evaluation forms, IKDC objective knee examination form, and radiological evaluation. Results were evaluated and compared with each other.ResultsThere was no significant difference in subjective effects or clinical examination between the two groups. Regarding radiological angles, the AAMP had more oblique graft orientation in the coronal plane than the MTTT, but both were found to be more slanted than native ACL. Also, the MTTT had succeeded to place the graft and tunnel more obliquity than the traditional non-anatomic TTT and better than the anatomic ranges despite having the graft inclination of the AAMP higher than the MTTT. The complaints from the patients and subjective scoring were found to be positively related to graft stability. Patients with healthier preoperative subjective state had a smoother postoperative period and better outcome.ConclusionThis study offers simple modifications to the transtibial technique to allow near anatomic ACL reconstruction with similar results comparable to the AAMP and with fewer complications.

Long-term stability of autologous bone graft of intraoral origin after lateral sinus floor elevation with simultaneous implant placement.

Lateral approach to maxillary sinus floor elevation (LSFE) with autologous bone grafts and simultaneous implant insertion is a widespread technique for prosthetic rehabilitation of the atrophic maxilla. To analyze implant survival and autologous bone graft resorption after LSFE, in patients with at least 5 years follow-up. Thirty-three patients (mean age 56 years, range 46-68 years) who had undergone LSFE with intraoral autologous bone graft from mandibular ramus and simultaneous implant insertion were included. A minimum of 5 years of follow-up was required. The total peri-implant bone height was measured at mesial and distal aspects of the implants immediately after surgery (T0) and after a period ranging from 5 to 11.5 years after surgery (mean 7.65 ± 1.80 years) (T1) on digital panoramic and periapical radiographs. Wilcoxon matched-pairs signed rank test was used to compare bone graft height at T0 and T1. The influence of patient-, surgery-, and implant-related factors on the outcomes was investigated. Of the 58 implants placed, no one was lost. All prostheses were in function, and no biological or mechanical complications occurred. The residual ridge height at the involved sites averaged 6.48 ± 1.72 mm. The mean bone height at grafted regions was 12.05 ± 2.47 mm at T0 and 12.13 ± 2.39 mm at T1 (not statistically significant). Marginal bone level change at T1 averaged -1.22 ± 1.60 mm. None of the evaluated factors significantly affected the results. Autologous bone grafts from intraoral donor sites display excellent volume stability over time that may contribute to optimal outcomes of the procedure.

Preconditioning and Cellular Engineering to Increase the Survival of Transplanted Neural Stem Cells for Motor Neuron Disease Therapy.

Despite the extensive research effort that has been made in the field, motor neuron diseases, namely, amyotrophic lateral sclerosis and spinal muscular atrophies, still represent an overwhelming cause of morbidity and mortality worldwide. Exogenous neural stem cell-based transplantation approaches have been investigated as multifaceted strategies to both protect and repair upper and lower motor neurons from degeneration and inflammation. Transplanted neural stem cells (NSCs) exert their beneficial effects not only through the replacement of damaged cells but also via bystander immunomodulatory and neurotrophic actions. Notwithstanding these promising findings, the clinical translatability of such techniques is jeopardized by the limited engraftment success and survival of transplanted cells within the hostile disease microenvironment. To overcome this obstacle, different methods to enhance graft survival, stability, and therapeutic potential have been developed, including environmental stress preconditioning, biopolymers scaffolds, and genetic engineering. In this review, we discuss current engineering techniques aimed at the exploitation of the migratory, proliferative, and secretive capacity of NSCs and their relevance for the therapeutic arsenal against motor neuron disorders and other neurological disorders.