Graft Stability Research Articles

Enhanced alveolar ridge preservation with hyaluronic acid-enriched allografts: a comparative study of granular allografts with and without hyaluronic acid addition

PurposeRidge preservation is essential to restore alveolar ridge volume and to enhance esthetic and functional outcomes for dental implants. The addition of hyaluronic acid to allogeneic bone substitute materials might enhance these outcomes. This clinical study evaluated the efficacy of ridge preservation after tooth extraction using granular allografts with and without hyaluronic acid addition.MethodsIn this retrospective study, 40 patients with compromised extraction sockets were enrolled. Among them, 19 received particulate allogeneic bone substitutes (Allo), 21 received allogeneic bone substitutes with hyaluronic acid (AlloHya). Vertical and horizontal graft stability, graft shrinkage rate, and bone mineral density were assessed using radiographic measurements on CBCT scans conducted before tooth extraction, directly after ridge preservation and after four months. Patients were followed up 12 months post-implantation.ResultsVertical height loss after 4 months was significantly greater in the Allo group (-0.82 ± 0.95 mm) compared to the AlloHya group (-0.19 ± 0.51 mm; p = 0.011). Graft shrinkage rate was 16.9 ± 11.5% (Allo) and 10.3 ± 7.7% (AlloHya) (p = 0.038). After four months, average bone density was significantly higher in the AlloHya compared to the Allo group (p = 0.004). Nearly all implants (39 out of 40) were classified as “Success” according to the ICOI scheme, with no differences in implant quality between the two study groups.ConclusionsImproved graft stability, reduced resorption, and increased bone density were observed in hyaluronic acid-enriched allografts compared to pure allografts. Adding hyaluronic acid to allogeneic bone grafts significantly enhanced outcomes in ridge preservation.

Partial-Full-Thickness Tunnel Technique and Supra-Crestal Sling Suture for Treatment of RT2 and RT3 Gingival Recessions: Technical Report with Two Cases.

The purpose of this technical report is to describe a modified tunnel surgical approach and connective tissue graft (CTG) stabilization technique for the treatment of gingival recessions with interproximal clinical attachment loss (ICAL). The partial-full-thickness (PFT) tunnel technique utilizes multiple vestibular incisions to facilitate creation of a split-mucoperiosteal tunnel that enhances tissue passivity and allows for coronal advancement of soft tissue with minimal tension. The supra-crestal sling (SCS) suture engages only the CTG, independent of the overlying tissue and stabilizes the CTG around the buccal and proximal root surfaces. The treatment approach of PFT tunnel preparation and CTG stabilization with the SCS suture was designed to optimize blood supply and maximize wound stability, resulting in complete root coverage with satisfactory clinical outcomes in RT2 and RT3 gingival recession. It is suggested that the PFT tunnel preparation with graft stabilization via the SCS suture has the potential to treat recessions with anatomical limitations associated with ICAL.

The relationship between the secondary implant stability quotient and oxidized implant-related factors: A retrospective study

ObjectiveThe present retrospective study aimed to determine the relationship between the secondary implant stability quotient and different parameters related to an oxidized implant. MethodsA total of 135 patients (305 oxidized implants) were included. Implant-related factors (length, diameter, surgical and loading protocols, grafting, insertion torque, and primary stability) were used for comparisons and linear regression analyses, using secondary ISQ as the dependent variable. ResultsAt the patient level, the mean time from implantation to secondary ISQ registration was 20.3 ± 29 weeks, and the mean secondary ISQ was 77.30 ± 7.22. The ISQ did not reveal significant differences regarding implant lengths, loading protocol, and simultaneous grafting. In contrast, platform diameters (3.5, 4.3, and 5.0), surgical protocols (one stage versus two stages), insertion torque (<35 Ncm versus >35 Ncm), and primary stability (achieved versus not achieved) all revealed significant secondary ISQ differences. Nevertheless, the regression analysis demonstrated that the platform diameter was the only variable significantly and positively predicted the secondary ISQ. Similar findings were found with the implant level analysis. ConclusionsAmong different implant- and protocol-related parameters, the platform diameter of the oxidized implant appears to be the only significant predictor of high secondary ISQ values at the time of superstructure connection.

Impregnation, dehydration and crosslinking of responsive organoboron polymer to generate smart gating membrane for multimolecular gradient separation

Responsive materials have garnered increasing attention in the membrane separation field. However, fabricating smart gating membranes with tunable pore sizes to separate complex systems remains challenging. Herein, gating membranes with boroxine skeleton and temperature-tunable pores were successfully fabricated by fixing lower critical solution temperature (LCST)-type organoboron polymers (poly(N-isopropylacrylamide-co-glycidyl methacrylate/3-aminophenylboronic acid), PNG-APBA) onto the membrane surface via "impregnation-dehydration-crosslinking" strategy. The conformational behavior of the NIPAM-containing polymer chains (shrinking above LCST-stretching below LCST) serves as a functional gate, enabling the membranes to achieve reversibly tunable pore sizes and surface properties. The modified membranes exhibit gradient separation capabilities for small/medium/large molecules in complex polymer systems through temperature-tunable channels. The tunable pores also provided a potential tool for the high-selectivity separation of mixed proteins, such as lysozyme (LZM) and hemoglobin (Hb). Notably, the conformational behavior of the polymer chains endowed the membranes with excellent self-cleaning ability (FRR> 99.5%), while the boroxine network enhanced the grafting stability of the polymer chains, ensuring effective reversibility and repeatability of membranes.

"The Jigsaw Puzzle Locking Technique" to Augment the Stabilization between the Septal Cartilage and Extension Graft in End-to-End Suture Fixation.

Nasal tip stability is crucial for long-lasting results. Usage of the extension graft is one of the most reliable stabilization techniques. With a septum in the midline, the extension graft is fixed end to end. The "jig-saw puzzle technique" reinforces this end-to-end fixation. The specific protrusion on one piece of the puzzle is inserted in a groove on adjacent piece. This settlement provides stabilization between the pieces. Application of this philosophy between the nasal septum and extension graft may provide a long-term fixation. Between April 2022 and March 2024, the "jig-saw puzzle technique" was applied in 26 female patients. Trapezoid-shaped protrusion was created at the septum. Similar indentation was created at the extension grafts. The protrusion is then settled in the indentation. The preop, immediate postoperative and one-year postoperative pictures are compared to assess the rotations and projections with Adobe Photoshop Program. All 26 patients were females with mean age 27.5 years (20-32). Satisfactory graft stabilization was obtained without loss of projection and rotation in all patients. Statistically significant difference was found between the preoperative, immediate postoperative and postoperative 1-year projection and rotation assessments of the patients (p=0.001; p<0.01). The results were evaluated at a 95% confidence interval and significance was evaluated at p<0.05 level. These statistical analyses verify that both projection and rotation were preserved with jig-saw puzzle technique. The jigsaw puzzle technique may provide suture-independent, long-term end-to-end fixation opportunity of the septal cartilage and the extension graft. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Premaxillary Graft with Costal Cartilage in Rhinoplasty: A Technique to Support the Nasal Tip.

Rhinoplasty is an ever-evolving field, with innovative techniques continually being developed to enhance both aesthetic and functional outcomes for patients. Increasingly, research has focused on the integral role of the facial skeleton in providing nasal support and projection. Central to the structural integrity of the nose is the maxillary bone, which occupies a pivotal position in the midface. The objective of this study is to assess the outcomes of patients who underwent rhinoplasty involving the placement of a premaxillary graft fashioned from costal cartilage. The study aims to evaluate the graft's tolerance, stability, and potential complications. The patient cohort comprised individuals who underwent open approach rhinoplasty with premaxillary insufficiency, necessitating the placement of a costal cartilage graft anterior to the nasal spine, performed by the same surgeon between 2021 and 2022. A total of 38 patients, consisting of 5 men and 33 women aged between 18 and 58years, were operated on during this period. Consistent maintenance of tip support was observed across all cases. Among the 33 patients, 20 were randomly chosen for a comparative assessment of the nasolabial angle in preoperative and postoperative profile photographs, demonstrating a statistically significant improvement. No complications such as graft displacement, scarring, extrusion, or infections were reported. The use of a premaxillary graft with costal cartilage appears to be a viable, well-tolerated option with favorable long-term outcomes. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Establishing and Characterizing the Molecular Profiles, Cellular Features, and Clinical Utility of a Patient-Derived Xenograft Model Using Benign Prostatic Tissues

Benign prostatic hyperplasia (BPH) is a common condition marked by the enlargement of the prostate gland, which often leads to significant urinary symptoms and a decreased quality of life. The development of clinically relevant animal models is crucial for understanding the pathophysiology of BPH and improving treatment options. This study aims to establish a patient-derived xenograft (PDX) model using benign prostatic tissues to explore the molecular and cellular mechanisms of BPH. PDXs were generated by implanting fresh BPH (transition zone) and paired normal (peripheral zone) prostate tissue from 8 patients under the renal capsule of immunodeficient male mice. Tissue weight, architecture, cellular proliferation, apoptosis, prostate-specific marker expression, and molecular profiles of PDXs were assessed after 1 week and 1, 2, or 3 months of implantation by immunohistochemistry, enzyme-linked immunosorbent assay, transcriptomics, and proteomics. Responses to finasteride, a standard-of-care therapy, were evaluated. PDXs maintained histologic and molecular characteristics of the parental human tissues. BPH, but not normal PDXs, demonstrated significant increases in weight and cellular proliferation, particularly at 1 month. Molecular profiling revealed specific gene and protein expression patterns correlating with BPH pathophysiology. Specifically, an increased immune and stress response was observed at 1 week, followed by increased expression of proliferation markers and BPH-specific stromal signaling molecules, such as BMP5 and CXCL13, at 1 month. Graft stabilization to preimplant characteristics was apparent between 2 and 3 months. Treatment with finasteride reduced proliferation, increased apoptosis, and induced morphologic changes consistent with therapeutic responses observed in human BPH. Our PDX model recapitulates the morphologic, histologic, and molecular features of human BPH, offering a significant advancement in modeling the complex interactions of cell types in BPH microenvironments. These PDXs respond to therapeutic intervention as expected, providing a valuable tool for preclinical testing of new therapeutics that will improve the well-being of BPH patients.

A Meta-Analysis of Surgical Outcomes in 25727 Patients Undergoing Anterior Cervical Discectomy and Fusion or Anterior Cervical Corpectomy and Fusion for Cervical Deformity.

Systematic Review. To evaluate which cervical deformity correction technique between anterior cervical discectomy and fusion (ACDF) and anterior cervical corpectomy and fusion (ACCF) produces better clinical, radiographic, and operative outcomes. We conducted a meta-analysis comparing studies involving ACDF and ACCF. Adult patients with either original or previously treated cervical spine deformities were included. Two independent reviewers categorized extracted data into clinical, radiographic, and operative outcomes, including complications. Clinical assessments included patient-reported outcomes; radiographic evaluations examined C2-C7 Cobb angle, T1 slope, T1-CL, C2-7 SVA, and graft stability. Surgical measures included surgery duration, blood loss, hospital stay, and complications. 26 studies (25727 patients) met inclusion criteria and were extracted. Of these, 14 studies (19077 patients) with low risk of bias were included in meta-analysis. ACDF and ACCF similarly improve clinical outcomes in terms of JOA and NDI, but ACDF is significantly better at achieving lower VAS neck scores. ACDF is also more advantageous for improving cervical lordosis and minimizing the incidence of graft complications. While there is no significant difference between approaches for most surgical complications, ACDF is favorable for reducing operative time, intraoperative blood loss, and length of hospital stay. While both techniques benefit cervical deformity patients, when both techniques are feasible, ACDF may be superior with respect to VAS neck scores, cervical lordosis, graft complications and certain perioperative outcomes. Further studies are recommended to address outcome variability and refine surgical approach selection.

The Lateral Wall of the Inferior Meatus as a New Graft Source for Rhinoplasty: Radiological Study and Surgical Technique.

Generally, revision rhinoplasty cases require the use of stiff grafts to restore the lost support. However, the majority of patients indicated for revision surgery present with a lack of a bony cartilaginous framework of the septum, especially after previous septoplasty. Thus, surgeons are compelled to harvest costal cartilage. At the same time, rib graft harvesting is associated with additional trauma and a risk of serious complications. Being ENT surgeons, we often resect a part of the lateral wall of the inferior nasal meatus during the extended endoscopic approach to the maxillary sinus. We supposed that this bone plate could be used as a donor site for rhinoplasty graft harvesting. The aim of our study was a radiological assessment of the feasibility and limits of using the inferior meatus lateral wall (IMLW) as a donor site for rhinoplasty bone graft.A retrospective evaluation of 100 CT scans of sinuses was conducted. Further measurements of the IMLW were performed: average length and width (28.06 ± 4.03 mm and 19.73 ± 3.08 mm, respectively), thickness (0.62 ± 0.21 mm), and average deviation from the sagittal plane (17.7 ± 9.53 degrees). According to the obtained measurements, the described donor site is appropriate for harvesting nice straight bony fragments.The IMLW bone graft was used in four revision rhinoplasty cases. There were no postoperative complications. During the long-term follow-up, patients reported significant improvement in aesthetics, function, and social aspects according to Rhinoplasty Outcome Evaluation. Thus, the described technique is an easy and safe method for bone harvesting for revision rhinoplasty. Our first experience demonstrated the convenience and stability of IMLW grafts for revision rhinoplasty during the follow-up period of up to 2 years.

Socket Preservation Using Platelet-Rich Fibrin and Free Gingival Grafts

The present randomised controlled trial is based on the null hypothesis that there is no difference in crestal bone levels (CBLs) following socket preservation (SP) using platelet-rich fibrin (PRF) and free gingival graft (FGG). The aim was to evaluate CBLs following SP using PRF and FGG. This study is a parallel-arm randomised controlled trial. Patients in the test and control groups underwent SP using PRF and FGG, respectively. Intraoral visual examination was performed to clinically assess signs of swelling, pus/abscess, and stability of sutures and graft. Self-rated postoperative pain was assessed after 1 week and 6 months using the visual analogue scale (VAS). At the 6-month follow-up, cone-beam computed tomography was performed to evaluate CBL in mesiodistal and buccolingual dimensions. The preoperative cone-beam computed tomographic images were superimposed with those taken at the 6-month follow-up to compare CBLs. Statistical comparisons were performed and level of significance was set at P < .05. The test and control groups each comprised 13 individuals with comparable ages. All teeth included in the test and control groups were located in the maxillary aesthetic zone. At the 1-week follow-up, VAS scores were higher in the control than in the test group (P < .01). At the 6-month follow-up, none of the participants reported self-rated pain. The change in buccolingual dimension was greater in the control group than in the test group (P < .05). Both FGG and PRF are effective techniques for SP; however, the latter technique is more effcacious in maintaining buccolingual dimensions of the extraction socket.

Double vertical interrupted suture for optimal adaptation and stabilization of free gingival graft around dental implants: a case report

BackgroundFree gingival graft is commonly used to augment the keratinized mucosa and vestibular depth around dental implants. The proper suturing technique is fundamental to achieve a successful result following free gingival graft. However, there are limited studies that focus on the details of the suturing methods to optimize graft adaptation. The purpose of this technical note is to describe a new suturing technique for optimal approximation and stabilization of free gingival graft around dental implants.Case presentationHere, we present a 53-year-old Persian female with peri-implantitis and lack of keratinized mucosa around mandibular implants who was a candidate for free gingival graft. A new suturing technique, double vertical interrupted suture, was conducted in the interimplant areas. In addition, the suspensory cross-mattress sutures were added to ensure the adaptation of the graft over the implants. The proposed suturing technique is useful for soft tissue augmentation around multiple implants with concave or uneven recipient bed.ConclusionThe present article describes a novel suturing technique for good adaptation and fixation of free gingival graft around dental implants.

Radiation grafted polyacrylic acid–polyurethane foam copolymer for efficient toxic metal removal from aqueous waste: a sustainable approach to waste management

The acrylic acid-grafted functionalized base polyurethane foam (PAA-g-PUf) is synthesized through mutual radiation grafting technique using acrylic acid as functional monomers and polyurethane form (PUf) with macroporous structure as base polymer, for the extraction of lead from the aqoueous waste streams. The incorporation of functionality on PUf is identified and confirmed by FT-IR spectroscopy, degree of grafting and thermal stability by TGA–DSC technique while the surface morphology, and pores dimensions are evaluated by SEM techniques. The kinetics measurements indicate that the synthesized sorbent reaches its saturation sorption capacity within 10 min at ~ 25 °C under near-neutral pH condition. The monolayer sorption capacity of the synthesized PAA-g-PUf for lead ion (Pb2+) is calculated from Langmuir’s model and found to be ~ 257 mg g−1, which is quite good as compared to the other functionalized material available. These grafted foams are quite efficient over a wide range of concentrations and temperature of the experimental solutions. In this study, the adsorbed lead ions are eluted out in 0.5 M HCl strippent efficiently. These sorbents exhibit excellent reusability up to five cycles without losing appreciable capacity, suggesting better usability in real water samples for many cycles. The polyurethane foam used was obtained from municipal waste, and hence, they cannot generate any additional secondary waste to the environment and make the process more sustainable and economically viable.Graphical abstract

Technical feasibility and device stability of the Gore Excluder iliac branch endoprosthesis as abdominal aortic bifurcated device

The aim is to describe the technical feasibility, early outcomes, and graft stability of the Excluder iliac branch endoprosthesis (W.L. Gore & Associates) used as an infrarenal abdominal bifurcated endograft in cases unsuitable for standard endovascular aortic repair. The technique was used in 13 cases with abdominal and/or iliac aneurysms (n = 6), occlusive disease (n = 3), or complex aneurysms in association with a proximal fenestrated/branched endograft (n = 4). Technical success was 100%, and there were no adverse events, with 100% graft stability at 3 months. This case series demonstrates, in extremely selected cases, the feasibility and safety of Excluder iliac branch endoprosthesis used as an infrarenal aortic bifurcated device.

Intermittent sliding-lock-knot suture for limbal conjunctival autograft fixation in pterygium surgery: a technique note.

To report a technique used with intermittent sliding-lock-knot (ISLK) fixation for limbal conjunctival autografts in pterygium surgery and compared with those of routine intermittent (RI) fixation. Consecutive patients with primary pterygium who had undergone pterygium excision combined with limbal conjunctival autograft transplantation between March 2021 and March 2022 at our institute were retrospectively analyzed. Primary outcome measures were mean duration of surgery and suture removal, degree of conjunctival hyperemia on postoperative day 1, pain score at suture removal, postoperative symptoms at 6mo, including conjunctival hyperemia, foreign body sensation, and graft stability. Ninety-eight patients underwent monocular surgery and were divided into ISLK (51 eyes) and RI (47 eyes) groups according to the type of conjunctiva autograft fixation method planned. There was no significant difference in mean duration of surgery between the two groups (18.59±2.39min vs 18.15±2.20min, P=0.417); however, compared to the RI group, shorter suture removal times were observed in the ISLK group [0.58min (0.42-0.87) vs 3.00min (2.21-4.15), P<0.001]. The degree of conjunctival hyperemia on postoperative day 1 was milder in the ISLK group (P<0.001). Pain scores at suture removal were lower in the ISLK group than in RI group [1 (0-3) vs 2 (1-4), P<0.001]. Postoperative symptoms at 6mo were comparable between the groups (P=0.487), with no recurrence. ISLK is an innovative method for limbal conjunctival autograft fixation after pterygium excision. Compared to RI fixation, ISLK facilitates suture removal and reduces discomfort, with comparable surgery duration and less conjunctival hyperemia.

3D printing of Ceffe-infused scaffolds for tailored nipple-like cartilage development

The reconstruction of a stable, nipple-shaped cartilage graft that precisely matches the natural nipple in shape and size on the contralateral side is a clinical challenge. While 3D printing technology can efficiently and accurately manufacture customized complex structures, it faces limitations due to inadequate blood supply, which hampers the stability of nipple-shaped cartilage grafts produced using this technology. To address this issue, we employed a biodegradable biomaterial, Poly(lactic-co-glycolic acid) (PLGA), loaded with Cell-Free Fat Extract (Ceffe). Ceffe has demonstrated the ability to promote angiogenesis and cell proliferation, making it an ideal bio-ink for bioprinting precise nipple-shaped cartilage grafts. We utilized the Ceffe/PLGA scaffold to create a porous structure with a precise nipple shape. This scaffold exhibited favorable porosity and pore size, ensuring stable shape maintenance and satisfactory biomechanical properties. Importantly, it could release Ceffe in a sustained manner. Our in vitro results confirmed the scaffold’s good biocompatibility and its ability to promote angiogenesis, as evidenced by supporting chondrocyte proliferation and endothelial cell migration and tube formation. Furthermore, after 8 weeks of in vivo culture, the Ceffe/PLGA scaffold seeded with chondrocytes regenerated into a cartilage support structure with a precise nipple shape. Compared to the pure PLGA group, the Ceffe/PLGA scaffold showed remarkable vascular formation, highlighting the beneficial effects of Ceffe. These findings suggest that our designed Ceffe/PLGA scaffold with a nipple shape represents a promising strategy for precise nipple-shaped cartilage regeneration, laying a foundation for subsequent nipple reconstruction.

The "Pocket" Technique: A Novel Surgical Technique for Repair of Glaucoma Drainage Device Tube Exposure.

Presented is a novel surgical technique, termed the "pocket" technique, of scleral patch graft placement into a subconjuntival pocket to cover exposed glaucoma tube shunts, which is particularly useful in cases of scarred and thinned conjunctiva and Tenons. Exposure of glaucoma tube shunts is an uncommon postoperative complication which poses a significant risk to the patient and may be difficult to repair. In this case series, the authors present 2 cases using a novel surgical technique, the "pocket" technique, to place a scleral patch graft to address tube exposure. Patient 1 remained free of tube exposure at most recent follow-up visit after 21 months, and patient 2 remained free of tube exposure at most recent follow-up visit after 4 months. This technique offers an elegant surgical option that has multiple benefits; it allows for stability of the scleral patch graft even in cases of scarred down, thinned conjunctiva with minimal Tenons, allows for repair along the entire length of the tube shunt including perilimbal exposures, and allows for secondary healing when there is not enough conjunctiva to cover both the opening and the patch. These advantages make the "pocket" technique a quick to perform, minimally invasive surgical approach that is useful for addressing both difficult and straightforward tube exposure cases.

Young men undergoing anterior cruciate ligament reconstruction with patellar tendon autograft and anteromedial drilling outperform at 5- to 10-year follow-up in terms of graft stability and activity levels compared to those undergoing reconstruction with hamstring autograft and transtibial drilling

ObjectiveTo compare 5- to 10-year outcomes of anterior cruciate ligament (ACL) reconstruction in young men performed with bone-patellar tendon bone (BPTB) autograft and anteromedial portal to reconstruction with hamstring autograft and transtibial technique. It was hypothesised that in young adult men, at 5- to 10-year follow-up, superior restoration of knee laxity and activity levels would be demonstrated using BPTB autograft and anteromedial portal technique. MethodsNinety-four men who had ACL reconstruction with BPTB autograft and anteromedial portal were eligible for comparison to 106 men who had reconstruction with hamstring autograft and transtibial technique. Inclusion criteria were: (1) age 18–35 years, (2) ACL tear caused by sports trauma only, (3) no concomitant ligament reconstruction and (4) 5- to 10-year follow-up. Outcome measures compared between the two groups included Lachman and pivot shift tests, KT side-to-side difference, Tegner and Marx scores, International Knee Documentation Committee (IKDC)-subjective score, Knee Osteoarthritis Outcome Scale (KOOS), Short Form (SF)-36, and single hop test for distance. P value ​< ​0.05 indicated statistical significance. ResultsForty-five patients with BPTB and 55 patients with hamstring ACL reconstruction were available for in-person assessment at 5–10 years after surgery. Outcomes in the BPTB group compared to the hamstring group showed KT difference 1.4 ​± ​1.9 mm vs. 2.8 ​± ​2.3 mm (p ​< ​0.01), pivot shift grade 2–3 in 4% vs. 34% (p ​< ​0.01), return to preinjury Tegner level in 51% vs. 36% (p ​= 0.1) and to preinjury Marx score in 29% vs. 11% (p ​= 0.02), and IKDC-subjective 88 ​± ​10 vs. 82 ​± ​13 vs (p ​< ​0.01), respectively. Statistically significant inter-relationships were found between KT side-to-side difference and the Tegner, Marx and IKDC-subjective scores at follow-up (r ​= ​−0.314, p ​< ​0.01; r ​= ​−0.263, p ​< ​0.01; r ​= ​−0.218, p ​= ​0.03, respectively). ConclusionYoung men undergoing ACL reconstruction with patellar tendon autograft and anteromedial drilling outperform at 5- to 10-year follow-up in terms of graft stability and activity levels compared to young men undergoing reconstruction with hamstring autograft and transtibial drilling. Level of EvidenceIII (Retrospective cross-sectional comparative study).

Maxillary Sinus Augmentation with Anorganic Bovine Bone Mineral of Different Particle Sizes: A Split-Mouth Study with Histomorphometric, Radiographic, and Clinical Analyses.

The aim of the present study was to compare the histomorphometrically evaluated new bone formation (NB), the radiographically measured graft stability, and the clinical implant outcome for maxillary sinus augmentation grafted with deproteinized bovine bone mineral (DBBM) with either small (Bio-Oss-S, Geistlich) or large (Bio-Oss-L, Geistlich) particles. Using a split-mouth study design, bilateral maxillary sinus augmentation was performed in 13 patients either with Bio-Oss-S particles (0.25 to 1 mm) or Bio-Oss-L particles (1 to 2 mm). After a healing period of 6 months, bone biopsies were axially retrieved in the molar region for histologic/histomorphometric analysis of NB, including subsequent staged implant placement. To determine graft stability, the maxillary sinus augmentation vertical graft heights were radiographically measured immediately after sinus augmentation, at implant placement, and at the 2- and 4-year post-augmentation follow-ups. In addition, the clinical implant-prosthodontic outcome (survival/ success/marginal bone loss) was assessed at 1 and 3 years post-loading. A total of 22 sinuses from 11 patients with split-mouth evaluation were ultimately available for data and statistical analysis. Histomorphometric analysis of the axially retrieved bone biopsies revealed the presence of NB (S: 25.5% ± 7.0% vs L: 23.6% ± 11.9%; P = .640), residual graft particles (S: 19.6% ± 9.2% vs L: 17.5% ± 6.3%; P = .365) as well as connective tissue (S: 54.9% ± 9.2% vs L: 58.9% ± 12.5%; P = .283), without significant differences between the use of small (Bio-Oss-S) and large (Bio-Oss-L) particles. However, there was significantly (P = .021) higher bone-to-graft contact (BGC) for the small-particle graft sites (27.9% ± 14.8%) compared to the large-particle graft sites (19.9% ± 12.9%), representing a significantly higher osteoconductivity. Both particle sizes showed significant (P < .01) vertical graft height reduction over time (4 years) of about 10%, with predominant graft reduction in the time period between sinus augmentation and implant placement compared to any follow-up periods after implant placement. At the 3-year post-loading implant evaluation, all implants and prostheses survived (100%), and the peri-implant marginal bone loss (S: 0.52 ± 0.19 mm; L: 0.48 ± 0.15 mm) as well as the peri-implant health conditions (S: 87.5%, L:81.2%) did not differ between implants inserted with the two different xenograft particles used. The use of small and large bovine xenograft particles for maxillary sinus augmentation provides for comparable bone formation, ensuring stable graft dimensions combined with high implant success and healthy peri-implant conditions. However, small particle size resulted in a higher BGC, providing for higher osteoconductivity than with the larger particle size.

Mechanical Characteristics of Individualized Biodegradable Augmentation Scaffold-In Vitro Pilot Study.

The alveolar ridge reconstruction of vertical and combined bone defects is a non-predictable procedure with varying percentages of success. The greatest challenge for vertical and combined bone augmentation is to maintain mechanical stability of the bone graft; therefore, it is mandatory to provide and preserve space for bone regeneration. The development of biomaterials and 3D printing has enabled the use of polymer scaffolds in the reconstruction of alveolar ridge defects. The aim of this pilot study was to evaluate the mechanical characteristics of an innovative individualized biodegradable polylactic acid (PLA) scaffold, under dynamic conditions, simulating biodegradation and the influence of masticatory forces. After the design and 3D printing of PLA scaffolds, two groups of 27 scaffolds were formed according to the compression testing procedure. The compression tests were performed in occlusal and lateral directions. In each of the two groups, nine subgroups of three scaffolds were formed for different testing periods during in vitro degradation with a total period of 16 weeks. Results showed that biodegradation and load application had no significant influence on mechanical characteristics of tested scaffolds. It can be concluded that simulated masticatory forces and biodegradation do not significantly influence the mechanical characteristics of an individualized biodegradable augmentation scaffold.

A Finite Element Model to Investigate the Stability of Osteochondral Grafts Within a Human Tibiofemoral Joint

Osteochondral grafting has demonstrated positive outcomes for treating articular cartilage defects by replacing the damaged region with a cylindrical graft consisting of bone with a layer of cartilage. However, factors that cause graft subsidence are not well understood. The aim of this study was to develop finite element (FE) models of osteochondral grafts within a tibiofemoral joint, suitable for an investigation of parameters affecting graft stability. Cadaveric femurs were used to experimentally calibrate the bone properties and graft-bone frictional forces for use in corresponding image-based FE models, generated from µCT scan data. Effects of cartilage defects and osteochondral graft repair were measured by examining contact pressure changes using further in vitro tests. Here, six defects were created in the femoral condyles, which were subsequently treated with osteochondral autografts or metal pins. Matching image-based FE models were created, and the contact patches were compared. The bone material properties and graft-bone frictional forces were successfully calibrated from the initial tests with good resulting levels of agreement (CCC = 0.87). The tibiofemoral joint experiment provided a range of cases that were accurately described in the resultant pressure maps and were well represented in the FE models. Cartilage defects and repair quality were experimentally measurable with good agreement in the FE model pressure maps. Model confidence was built through extensive validation and sensitivity testing. It was found that specimen-specific properties were required to accurately represent graft behaviour. The final models produced are suitable for a range of parametric testing to investigate immediate graft stability.