A comparison of ice wrap and subacromial injection for postoperative pain and edema control following arthroscopic rotator cuff repair.

BACKGROUND: Postoperative pain and edema are the most common problems associated with arthroscopic rotator cuff repair. The purpose of the present study was to compare ice wrap and subacromial injection (SI) as treatments for early postop pain and edema control and to contrast them with a control group. MATERIALS AND METHODS: 59 patients treated with arthroscopic rotator cuff repair were randomized into three groups: 23 patients who received an ice wrap, 20 patients who received a SI, and a control group of 16 patients. RESULTS: Patient demographics, comorbidities, tear retraction, degree of fatty muscle degeneration, surgical procedures, and amount of irrigation fluid were similar for the three groups, which also showed similar results regarding postoperative pain and edema control as well as analgesic consumption. CONCLUSIONS: The present study failed to show any difference in effectiveness between the two most common pain management modalities, or between those modalities and the control group. LEVEL OF EVIDENCE: IV, prospective observational study.

Suture anchor fixation strength in the Latarjet procedure: a biomechanical study in cadavers.

BACKGROUND: The use of metallic screws for graft fixation during the Latarjet procedure is not devoid of complications. The purpose of the present cadaver study was to determine the initial strength of coracoid graft fixation using suture anchors and compare it to that of the traditional screw fixation of the graft using a fresh frozen human shoulder cadaver model. MATERIALS AND METHODS: Twelve unpaired fresh frozen cadaver shoulders were utilized. In the first group, suture anchor fixation of the graft was used, while 3.75-mm cannulated screws were used in the second group. The specimens were then cyclically loaded from 5 to 150 N at a speed of 0.05 mm/s for 100 cycles. After cyclic loading, each specimen was then loaded at a constant rate of 0.5 mm/s until 7 mm of displacement. Cyclic elongation, peak-to-peak displacement, stiffness and maximum load were measured. RESULTS: There were no significant differences between the traditional screw fixation and fixation using suture anchors in elongation, peak-to-peak displacement, stiffness and maximum load. CONCLUSIONS: In this study, traditional screw fixation and fixation using suture anchors did not significantly affect biomechanical performance in a classic Latarjet procedure.

Suture Anchor Fixation in Osteoporotic Bone: A Biomechanical Study in an Ovine Model.

PURPOSE: To evaluate the load to failure strength of anchor techniques suitable for osteoporotic bone. METHODS: Using an osteoporotic ovine model in 72 humeri, 6 fixation techniques were tested. Group 1: two interlocking 5-mm anchors with fewer, wider threads; group 2: one 5-mm anchor; group 3: one 5-mm anchor reinforced laterally by a 6.5-mm cancellous screw; group 4: one 5-mm anchor in an area reinforced with a cancellous plug; group 5: two interlocking 5-mm anchors with smaller threads; group 6: one 5-mm smaller threaded anchor. After a 10-N preload, the specimens were cyclically loaded between 10 N and 30 N for 50 cycles and then destructively tested. Peak-to-peak displacement, cyclic elongation, ultimate load, stiffness, and failure mode were recorded. RESULTS: Group 1 had lower peak-to-peak displacement than group 3 (P = .001), group 5 (P = .001), and group 6 (P = .033). In addition, group 1 showed lower cyclic elongation than group 3 (P = .001), group 5 (P = .035), and group 6 (P = .001). Group 1 had a higher ultimate load than group 2 (P = .002), group 3 (P = .019), and group 6 (P = .006). Group 1 also showed higher stiffness than group 2 (P = .007) and group 3 (P = .022). Mode of failure was predominantly caused by anchor pullout for all of the groups except group 3, which mainly failed by suture rupture. CONCLUSIONS: Two interlocking suture anchors are stronger than a single anchor in osteoporotic bone. The anchor with fewer, wider threads and a smaller core diameter showed greater strength and less elongation than the other constructs. Reinforcement by cancellous autografting increased suture anchor strength. CLINICAL RELEVANCE: Considering concerns about suture anchor pullout from osteoporotic bone, interlocking a second suture anchor with the first increases load to failure resistance. Anchors with small core diameters and fewer but wider threads are more efficient in osteoporotic bone.

Femur can be lengthened over nail, along its mechanical axis : a modified lengthening over nail technique.

The theoretical risk of medialisation of the knee joint and the lateral shift of the lower extremity mechanical axis, due to achievement of lengthening along the anatomical axis is present in the process of lengthening with elongation nails and the "lengthening over nail" technique. With this new technique described in this study we aimed to prove that lengthening over nail can be performed along the mechanical axis of the femur. Six lower-limb models were used to perform three different lengthening techniques. In group 1, lengthening was achieved along the anatomical axis with an external fixator. In group 2, the clamps of the external fixator were adjusted at 6° to achieve lengthening along the mechanical axis. In group 3, eight different sized nails were applied with an external fixator (angle adjustable clamps were at 6°) to achieve lengthening along the mechanical axis by LON technique. Photographs were taken after each cm of lengthening and the distance from the mechanical axis line were measured. The modified LON technique described in this study provided lengthening along the mechanical axis. One of the main advantages of the procedure described in our study is the chance for reconsideration and revision of unforeseen angulations and malalignments, via the help of the distal angular adjustable clamps; during the time of the surgery for external fixator removal before application of the poller screws.

Biomechanical Performance of Hip Labral Repair Techniques.

PURPOSE: To determine the strength of various suture techniques and the impact of suture passer size on cyclically loaded hip labra. METHODS: We assigned 63 bovine hip labra to 9 simple knotless suture technique groups using OrthoCord suture: (1) penetrating grasper (2.6 mm)-placed horizontal mattress, (2) penetrating grasper-placed vertical mattress, (3) SutureLasso (1.8 mm)-placed vertical mattress, (4) penetrating grasper-placed oblique repair, (5) penetrating grasper-placed vertical mattress plus radiofrequency, (6) SutureLasso-placed horizontal mattress, (7) SutureLasso-placed oblique mattress, (8) SutureLasso-placed horizontal mattress plus radiofrequency, and (9) SutureLasso-placed oblique mattress plus radiofrequency. After 20 cycles of uniaxial tensile loading (5 to 80 N), destructive testing was performed. RESULTS: Penetrating grasper-placed horizontal mattress sutures showed lower ultimate failure loads than vertical and oblique mattress sutures (P < .05). Penetrating grasper-placed vertical mattress sutures had higher peak-to-peak displacement than SutureLasso-placed vertical mattress sutures (P = .04). SutureLasso-placed oblique mattress sutures had a higher ultimate load (P < .01) and stiffness (P = .04) than SutureLasso-placed horizontal mattress sutures. SutureLasso-placed horizontal mattress sutures had lower cyclic elongation than penetrating grasper-placed horizontal mattress sutures (P = .01) and lower ultimate load (P < .01) and stiffness than SutureLasso-placed vertical mattress sutures (P < .01). Horizontal mattress sutures with radiofrequency had a higher ultimate load (P = .02), stiffness, and cyclic elongation (P < .01) than without radiofrequency. CONCLUSIONS: A horizontal mattress hip labrum stitch shows a lower ultimate failure load than vertical or oblique mattress stitches. Smaller-diameter suture-passing devices show less cyclic displacement and elongation than larger-diameter devices. Radiofrequency labral treatment does not alter vertical stitch strength but does alter horizontal mattress stitch strength. CLINICAL RELEVANCE: Vertical and oblique stitches are stronger than horizontal stitches. A 1.8-mm passing device shows a better cyclic loading performance than a 2.6-mm device.

Operative treatment of chondroblastoma: a study of 11 cases.

Aim of the study was to review the radiological, clinical results of 11 chondroblastoma cases treated at our institute between 2003-2013. All patients with chondroblastoma included in this study underwent intra-lesional curettage+/-bone grafting. Follow up for healing of chondroblastoma lesions and detection of any local recurrence was assessed on clinical and radiological bases. The functional outcome was assessed by the Musculoskeletal Tumour Society scoring system. The mean follow-up period was 6.1 years. There were three recurrences (two femoral head, one proximal tibia). The mean Musculoskeletal Tumour Society functional score was 21. First line aggressive treatment seems appropriate for chondroblastoma especially when localized at lower extremities.

The effect of inclination angle on the strength of vertical mattress configuration for meniscus repair.

PURPOSE: Vertical mattress configuration is the strongest of all other configurations and the repairing devices of meniscus repair. The purpose was whether increasing the inclination angle between two strands of the vertical mattress configuration by increasing the amount of meniscus tissue captured would enhance the initial strength of the construction. METHODS: A 2-cm long anteroposterior vertical longitudinal incision was created in two groups of bovine medial menisci. In the first group, the distance between the two vertical suture strands and the vertical horizontal sutures on the capsular side of the meniscal lesion was 2 mm (Group 1). In the second group, the distance was 5 mm (Group 2). The following repair specimens underwent cyclic loading prior to loading the failure testing. The endpoints included ultimate failure load (N), stiffness (N/mm) and cyclic displacement (mm) after the 100 cycles and the mode of failure. RESULTS: Group 1 (2 mm) (90.7 (±19.9) N) had lower ultimate load than Group 2 (5 mm) (120.8 (±24.5)) (P < 0.05). Stiffness and displacements during the cycling were not different between the groups (n.s.). All specimens failed by suture rupture. CONCLUSION: Increased inclination angle with increased distance between the two vertical suture strands on the capsular side of the meniscal lesion resulted in higher failure load compared to control group with lower inclination angle and distance on the capsular side.

Mechanical Comparison of Headless Screw Fixation and Locking Plate Fixation for Talar Neck Fractures.

For talar neck fractures, open reduction and internal fixation have been thought to facilitate revascularization and prevent osteonecrosis. Newer screw systems allow for placement of cannulated headless screws, which provide compression by virtue of a variable pitch thread. The present study compared the biomechanical fixation strength of cannulated headless variable-pitch screw fixation and locking plate fixation. A reproducible talar neck fracture was created in 14 fresh cadaver talar necks. Talar head fixation was then performed using 2 cannulated headless variable-pitch 4-mm/5-mm diameter (4/5) screws (Acutrak; Acumed, Hillsboro, OR) and locking plate fixation. Headless variable-pitch screw fixation had lower failure displacement than did locking plate fixation. No statistically significant differences were found in failure stiffness, yield stiffness (p = .655), yield load (p = .142), or ultimate load between the 2 fixation techniques. Cannulated headless variable-pitch screw fixation resulted in better failure displacement than locking plate fixation in a cadaveric talus model and could be considered a viable option for talus fracture fixation. Headless, fully threaded, variable-pitch screw fixation has inherent advantages compared with locking plate fixation, because it might cause less damage to the articular surface and can compress the fracture for improved reduction. Additionally, plate fixation can increase the risk of avascular necrosis owing to the wider incision and dissection of soft tissues.

The effects of tears in infraspinatus on other rotator cuff constituents.

The rotator cuff tear effects on glenohumeral joint tissues, such as superior labrum anterior-posterior (SLAP) lesions, have been studied experimentally or numerically in various cases. In relation to these studies, and as a novel feature of our study, infraspinatus (INF) muscle tear effects on other muscle force variations and stress and strain increases on glenoid labrum (GL), glenoid cartilage (GC) tissues, and a SLAP pathology were investigated. The ITK-SNAP Software (ISS) was used to segment the humerus and glenoid bone. The surface entities were segmented and exported to SolidWorks 2019, where the finite element model (FEM) was completed. Static optimizations of the muscle forces were calculated using a generic model in OpenSim 4.1 for the 0-3.88 s time interval to perform our finite element analyses (FEAs) in ANSYS 19.3 for the intact, partial torn, and fully torn INF muscle. The FEAs were also conducted for the specified time interval. The stress and strain increases on the GL, and GC tissues were determined to be critical when compared with yield strengths. In the case of fully torn INF, the GL and cartilage interfacial principal stress was calculated to be 3.3856 MPa. In the case of the fully torn INF, the principal stress that occurred on the GC tissue was calculated to be 42.465 MPa. In the case of the intact INF, the principal stress that occurred on the labrum was obtained as 4.257 MPa. These results showed that there was no detachment or disorder on the designated tissues caused by the INF muscle tear when the shoulder functioned at 60° of external rotation at 11° of abduction. Nonetheless, a minor amount of external force could cause severe pathological effects on the specified tissues.

Anatomic footprint of the direct head of the rectus femoris origin: cadaveric study and clinical series of hips after arthroscopic anterior inferior iliac spine/subspine decompression.

PURPOSE: The purposes of this study were to define the anatomy of the anterior inferior iliac spine (AIIS) and its relation to the footprint of the rectus femoris tendon and to evaluate on the clinical outcomes after AIIS/subspine decompression. METHODS: The rectus origin was dissected and detached in 11 male cadaveric hips with a mean age of 54.3 ± 14.3 years (range, 33 to 74 years). The proximal-distal and medial-lateral extent of the footprint and its relation to the AIIS and acetabular rim were evaluated, with the 12-o'clock position defined as directly lateral at the insertion of the indirect head of the rectus tendon and the 1- to 6-o'clock positions defined as anterior acetabular positions. To assess the safety and efficacy of subspine decompression for AIIS deformity, clinical correlation of a series of 163 AIIS decompressions (mean age, 27.8 years; age range, 14 to 52 years) performed from January 2011 to January 2012 was completed, and outcome scores, strength deficits, and ruptures were assessed by manual muscle testing and postoperative radiographs. All patients presented with symptomatic FAI with proximal femoral and/or acetabular deformity and type 2 (131 hips) or type 3 (32 hips) AIIS morphology as defined by Hetsroni et al. RESULTS: The mean proximal-distal and medial-lateral distances for the rectus origin footprint were 2.2 ± 0.1 cm (range, 2.1 to 2.4 cm) and 1.6 ± 0.3 cm (range, 1.2 to 2.3 cm), respectively. There was a characteristic bare area at the anteromedial AIIS. On the clock face, the lateral margin (1-o'clock to 1:30 position) and medial margin (2-o'clock to 2:30 position) of the AIIS and the indirect head of the rectus (12 o'clock) were consistent for all specimens. In the clinical series, 163 AIIS decompressions were performed for symptomatic subspine impingement. The mean modified Harris Hip Score was 63.1 points (range, 21 to 90 points) preoperatively compared with 85.3 points (range, 37 to 100 points) at a mean follow-up of 11.1 ± 4.1 months (range, 6 to 24 months) (P < .01). Short Form 12 scores improved significantly from a mean of 70.4 (range, 34 to 93) preoperatively to a mean of 81.3 (range, 31 to 99) postoperatively (P < .01). The mean pain score on a visual analog scale also improved significantly from a mean of 4.9 (range, 0.1 to 8.6) preoperatively to a mean of 1.9 (range, 0 to 7.8) postoperatively (P < .01). The mean alpha angle improved from 61.5° (range, 35° to 90°) preoperatively to 49° (range, 35° to 63°) postoperatively on anteroposterior radiographs and from 71° (range, 45° to 90°) preoperatively to 44.3° (range, 37° to 60°) postoperatively on lateral radiographs. No short- or long-term hip flexion deficits or rectus femoris avulsions were noted with up to 2 years' follow-up. CONCLUSIONS: The origin of the rectus femoris tendon is broad on the AIIS and protective against direct head detachment with subspine decompression. This broad origin and consistent bare area anteromedially on the AIIS can be readily used by surgeons to perform a safe AIIS resection in cases of symptomatic impingement. Arthroscopic subspine decompression in addition to osteoplasty for symptomatic cam- and/or pincer-type FAI deformities can reliably improve outcome scores without significant hip flexion deficits or AIIS/rectus femoris avulsions. CLINICAL RELEVANCE: The direct head of the rectus tendon has a broad insertion on the AIIS, and an area devoid of tendon provides a "safe zone" for subspine decompression in cases of symptomatic AIIS impingement.

Strength of different Krackow stitch configurations using high-strength suture.

The purpose of the present study concerning high-strength sutures was to determine whether increasing the number of locking loops with different size sutures or decreasing the suture size with increased suture strands would have any influence on the strength of Achilles tendon repair. A total of 32 fresh bovine Achilles tendon specimens were randomly assigned to 4 groups. For 3 of the groups, 1 suture was used (no. 2 or no. 5 FiberWire™ with 2 or 4 Krackow locking loops). For the fourth group, 2 sutures (2-0 FiberWire™) with 2 locking loops were used. After repair, the study groups underwent cyclic loading (0 to 200 N, 200 cycles) and then underwent tension to failure in a testing machine. Cyclic elongation, peak to peak displacement, ultimate load, stiffness, and failure mode were recorded for each specimen. The tendon width and thickness were measured in all specimens. The mean width, thickness, cyclic displacement, load to failure, and pull-out stiffness showed no differences among the 4 groups. The cyclic peak to peak displacements (0.01 ± 0.01 mm) were smallest with the no. 5 suture with 4 locking loops (p < .05), with no failure during cyclic loading, unlike in the other groups. In the group with 2-0 suture with 4 strands and 2 locking loops, 6 failed during cyclic loading. The number of locking loops used might have had an influence on the strength of the Krackow suture configuration using the larger diameter, high-strength sutures. However, decreasing the suture diameter, with a simultaneous increase in the number of strands, failed to improve the initial strength of the repair.

A Novel Electromechanical Intramedullary Nail System for Limb Lengthening.

Background/Purpose of the Study: Many methods have been developed to treat leg length discrepancies. Extensible intramedullary nails are the most commonly used systems. However, complications such as excessive distraction, blockage of the nail, aditional surgery, uncontrolled lengthening and much pain occur during the use of these systems, and the desired success rate cannot be achieved. This study aims to develop a new extensible intramedullary system with two mechanisms (electronical and mechanical) for femur and tibia that treats leg length inequalities in a way that allows lengthening without complications as much as possible and does not require a second surgical intervention. It was planned to perform basic mechanical and cadaver functional tests of the new system, which will be designed and developed for this purpose. Methods: The 3D design of the system has been completed with 3D computer software. A compact system has been developed that is mechanically activated by sudden axial loading and electronically activated by a controllable electric motor. Basic mechanical and functional tests of the new system have been performed within a cadaver. Results: The rapid prototype of the system with electronical and mechanical units has been produced. As a result of the mechanical tests (axial loading), the nail was found to be resistant to compression forces. Its application to the cadaver and function tests was successfully performed. Conclusions: We believe that the system we have developed will have advantages, such as working principle, ease of application, controlled lengthening, patient mobility compared to existing leg lengthening methods. The success of the system in practice will be evaluated by in-vivo animal experiments after more detailed mechanical experiments on cadavers. According to the results, it will be ready for human use by performing necessary restorations.

Fabrication of Helix aspersa Extract Loaded Gradient Scaffold with an Integrated Architecture for Osteochondral Tissue Regeneration: Morphology, Structure, and In Vitro Bioactivity.

Regeneration of osteochondral tissue with its layered complex structure and limited self-repair capacity has come into prominence as an application area for biomaterial design. Thus, literature studies have aimed to design multilayered scaffolds using natural polymers to mimic its unique structure. In this study, fabricated scaffolds are composed of transition layers both chemically and morphologically to mimic the gradient structure of osteochondral tissue. The aim of this study is to produce gradient chitosan (CHI) scaffolds with bioactive snail (Helix aspersa) mucus (M) and slime (S) extract and investigate the structures regarding their physicochemical, mechanical, and morphological characteristics as well as in vitro cytocompatibility and bioactivity. Gradient scaffolds (CHI-M and CHI-S) were fabricated via a layer-by-layer freezing and lyophilization technique. Highly porous and continuous 3D structures were obtained and observed with SEM analysis. In addition, scaffolds were physically characterized with water uptake test, micro-CT, mechanical analysis (compression tests), and XRD analysis. In vitro bioactivity of scaffolds was investigated by co-culturing Saos-2 and SW1353 cells on each compartment of gradient scaffolds. Osteogenic activity of Saos-2 cells on extract loaded gradient scaffolds was investigated in terms of ALP secretion, osteocalcin (OC) production, and biomineralization. Chondrogenic bioactivity of SW1353 cells was investigated regarding COMP and GAG production and observed with Alcian Blue staining. Both mucus and slime incorporation in the chitosan matrix increased the osteogenic differentiation of Saos-2 and SW1353 cells in comparison to the pristine matrix. In addition, histological and immunohistological staining was performed to investigate ECM formation on gradient scaffolds. Both characterization and in vitro bioactivity results indicated that CHI-M and CHI-S scaffolds show potential for osteochondral tissue regeneration, mimicking the structure as well as enhancing physical characteristics and bioactivity.

Computational analysis of the effects of interprosthetic distance on normal and reduced cortical thickness femur models.

Distal femoral fractures associated with the femoral stem in a well-fixed hip arthroplasty pose a risk of an interprosthetic fracture, the treatment of which is known as difficult. To effectively prevent and treat IP fractures, biomechanical effects must be demonstrated. We defined eight variations of the interprosthetic distance ranging from 48 mm overlap to 128 mm gap. Femoral geometries with normal and reduced cortical thickness were modeled to evaluate the effects of cortical thickness. In addition to the intact model, a total of 16 finite element models were analyzed under physiological boundary conditions. Maximum and minimum principal strains on the lateral and medial cortex surfaces were always found to be greater in models with reduced cortical thickness than in normal femurs. The model with 48 mm overlapping interprosthetic distance produced the least peak strain and the model with 16 mm interprosthetic gap produced the greatest strain with both normal and reduced cortical thickness. The screw holes produced local strain concentrations and increased the peak strains on the cortex surfaces, especially close to the stem tip. Statistically, a significant correlation (R2 = 0.9483) was found between strain shielding and interprosthetic distance. Axial stiffness, interfragmentary shear motion, and maximum von-Mises stress on the distal plate showed a high correlation with the interprosthetic distance. It was concluded that the overlapping structures are superior to other fixations we analyzed in that they offer better mechanical stability and eliminates the local strain concentrations.

Effects of degree of translation or rotation of acetabular fragment of periacetabular osteotomy procedure on pelvic X-ray parameters.

The present study aims to investigate the effect of amount of lateralization and/or anteversion of the point where the iliac cut meets with the posterior column cut of periacetabular osteotomy (PAO), on X-ray parameters such as Center of edge (CE) angle, retroversion index (RVI) and sharp angle. Fourteen patients with symptomatic hip dysplasia (CE° < 20°) were included. Pelvis Computerized tomography (CT) sections were used for 3D printing. PAO was then performed on these models. The point (A), 1 cm lateral to the pelvic brim, is marked where the iliac cut intersects the posterior column cut. In Group I (1.5-0), point A is lateralized parallel to the osteotomy line for 1.5 cm. In Group II (1.5-0.5), it is additionally anteverted for 0.5 cm. In Group III (3-0), point A is lateralized for 3 cm and then additionally anteverted for 1 cm (Group IV: 3-1). Radiographs were taken in each stage. The lateral CE angle, RVI and sharp angle were measured. All had an increase in the CE angle and RVI and a decrease in the sharp angle compared to the control group (P < 0.05). The amount of CE angle (ΔCE) or RVI increase (ΔRV) was as follows: 3-1(38°, 0.3) > 3-0(27°, 0.2) and 1.5-0.5(25°, 0.1) > 1.5-0(17°, 0.07) (P < 0.05) (with no difference between groups 1.5-0.5 and 3-0, P = 0.7). The amount of sharp angle decrease was as follows: 3-1(20°), 3-0(18°) < 1.5-0.5(11°) < 1.5-0(8°) (P < 0.05). The lateralization of the intersection point where the iliac wing cut meets with the posterior column cut along the cut surface led to an increase of lateral cover and focal retroversion. Additional anteversion leads to further increases in those parameters, while groups 1.5-0.5 and 3-0 did not differ between.

Fabrication of 3D Printed poly(lactic acid) strut and wet-electrospun cellulose nano fiber reinforced chitosan-collagen hydrogel composite scaffolds for meniscus tissue engineering.

The main goal of the study was to produce chitosan-collagen hydrogel composite scaffolds consisting of 3D printed poly(lactic acid) (PLA) strut and nanofibrous cellulose for meniscus cartilage tissue engineering. For this purpose, first PLA strut containing microchannels was incorporated into cellulose nanofibers and then they were embedded into chitosan-collagen matrix to obtain micro- and nano-sized topographical features for better cellular activities as well as mechanical properties. All the hydrogel composite scaffolds produced by using three different concentrations of genipin (0.1, 0.3, and 0.5%) had an interconnected microporous structure with a swelling ratio of about 400% and water content values between 77 and 83% which is similar to native cartilage extracellular matrix. The compressive strength of all the hydrogel composite scaffolds was found to be similar (∼32 kPa) and suitable for cartilage tissue engineering applications. Besides, the hydrogel composite scaffold comprising 0.3% (w/v) genipin had the highest tan δ value (0.044) at a frequency of 1 Hz which is around the walking frequency of a person. According to the in vitro analysis, this hydrogel composite scaffold did not show any cytotoxic effect on the rabbit mesenchymal stem cells and enabled cells to attach, proliferate and also migrate through the inner area of the scaffold. In conclusion, the produced hydrogel composite scaffold holds great promise for meniscus tissue engineering.

Loofah-chitosan and poly (-3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) based hydrogel scaffolds for meniscus tissue engineering applications.

The meniscus is a fibrocartilaginous tissue that is very important for the stability of the knee joint. However, it has a low ability to heal itself, so damage to it will always lead to articular cartilage degeneration. The goal of this study was to make a new type of meniscus scaffold made of chitosan, loofah mat, and PHBV nanofibers, as well as to describe hydrogel composite scaffolds in terms of their shape, chemical composition, mechanical properties, and temperature. Three different concentrations of genipin (0.1, 0.3, and 0.5 %) were used and the optimal crosslinker concentration was 0.3 % for Chitosan/loofah (CL) and Chitosan/loofah/PHBV fiber (CLF). Scaffolds were seeded using undifferentiated MSCs and incubated for 21 days to investigate the chondrogenic potential of hydrogel scaffolds. Cell proliferation analyses were performed using WST-1 assay, GAG content was analyzed, SEM and fluorescence imaging observed morphologies and cell attachment, and histological and immunohistochemical studies were performed. The in vitro analysis showed no cytotoxic effect and enabled cells to attach, proliferate, and migrate inside the scaffold. In conclusion, the hydrogel composite scaffold is a promising material for engineering meniscus tissue.

Development of biological meniscus scaffold: Decellularization method and recellularization with meniscal cell population derived from mesenchymal stem cells.

Tissue engineering approaches which include a combination of cells and scaffold materials provide an alternative treatment for meniscus regeneration. Decellularization and recellularization techniques are potential treatment options for transplantation. Maintenance of the ultrastructure composition of the extracellular matrix and repopulation with cells are important factors in constructing a biological scaffold and eliminating immunological reactions.The aim of the study is to develop a method to obtain biological functional meniscus scaffolds for meniscus regeneration. For this purpose, meniscus tissue was decellularized by our modified method, a combination of physical, chemical, and enzymatic methods and then recellularized with a meniscal cell population composed of fibroblasts, chondrocytes and fibrochondrocytes that obtained from mesenchymal stem cells. Decellularized and recellularized meniscus scaffolds were analysed biochemically, biomechanically and histologically. Our results revealed that cellular components of the meniscus were successfully removed by preserving collagen and GAG structures without any significant loss in biomechanical properties. Recellularization results showed that the meniscal cells were localized in the empty lacuna on the decellularized meniscus, and also well distributed and proliferated consistently during the cell culture period (p < 0.05). Furthermore, a high amount of DNA, collagen, and GAG contents (p < 0.05) were obtained with the meniscal cell population in recellularized meniscus tissue.The study demonstrates that our decellularization and recellularization methods were effective to develop a biological functional meniscus scaffold and can mimic the meniscus tissue with structural and biochemical features. We predict that the obtained biological meniscus scaffolds may provide avoidance of adverse immune reactions and an appropriate microenvironment for allogeneic or xenogeneic recipients in the transplantation process. Therefore, as a promising candidate, the obtained biological meniscus scaffolds might be verified with a transplantation experiment.

Three-Dimensionally-Printed Joint-Preserving Prosthetic Reconstruction of Massive Bone Defects After Malignant Tumor Resection of the Proximal Tibia.

Joint-preserving prosthetic reconstruction for massive bone defects has the potential to be a new and revolutionary treatment option. In this paper, we discuss the case of a 30-year-old female patient who presented with pain and swelling around the knee for three months. The patient underwent this procedure. Postoperative patient satisfaction, pain scores, and range of motion results were found to be promising. We believe that this method has the potential to be the next stage in the quest for better treatment options for this condition.

Scapular spine base fracture with long outside-in superior or posterior screws with reverse shoulder arthroplasty.

BACKGROUND: The purpose of the present study was to determine how long superior screws alone or in combination with posterior placement of metaglene screws protruding and penetrating into the scapular spine in reverse total shoulder arthroplasty affect the strength of the scapular spine in a fresh cadaveric scapular model. METHODS: Seven fresh cadaver scapulas were allocated to the control group (short posterior and superior screws) and seven scapulars to the study group (spine base fixation with a four long screws, three with both long superior and long posterior screws). RESULTS: The failure load was lower in the spine fixation group (long screw, 869 N vs. short screw, 1,123 N); however, this difference did not reach statistical significance (p>0.05). All outside-in long superior or superior plus posterior screws failed due to scapular spine base fracture; failures in the short screw group were due to acromion fracture. An additional posterior outside-in screw failed to significantly decrease the failure load of the acromion spine. CONCLUSIONS: The present study highlights the significance of preventing a cortical breach or an outside-in configuration when a superior or posterior screw is inserted into the scapular spine base.