Case report: A 10 years follow-up of periprosthetic femoral fracture after total hip arthroplasty in osteopetrosis.

Osteopetrosis is an inherited disorder characterized by increased bone density and brittle bone quality. Degenerative changes often occur after the age of 40 in patients with osteopetrosis. Operative intervention is the primary treatment option if the clinical manifestation of secondary osteoarthritis is severe. A 44-year-old male suffering autosomal dominant osteopetrosis and progressive unilateral hip osteoarthritis required a total hip arthroplasty. However, there were several technical challenges associated with this procedure including creating a femoral medullary canal and developing a Vancouver type B2 periprosthetic femoral fracture postoperatively. To afford some experience for the management of similar cases, we here present our technical solutions to these problems.

[Three-dimensional parallel collagen scaffold promotes tendon extracellular matrix formation].

OBJECTIVE: To investigate the effects of three-dimensional parallel collagen scaffold on the cell shape, arrangement and extracellular matrix formation of tendon stem cells. METHODS: Parallel collagen scaffold was fabricated by unidirectional freezing technique, while random collagen scaffold was fabricated by freeze-drying technique. The effects of two scaffolds on cell shape and extracellular matrix formation were investigated in vitro by seeding tendon stem/progenitor cells and in vivo by ectopic implantation. RESULTS: Parallel and random collagen scaffolds were produced successfully. Parallel collagen scaffold was more akin to tendon than random collagen scaffold. Tendon stem/progenitor cells were spindle-shaped and unified orientated in parallel collagen scaffold, while cells on random collagen scaffold had disorder orientation. Two weeks after ectopic implantation, cells had nearly the same orientation with the collagen substance. In parallel collagen scaffold, cells had parallel arrangement, and more spindly cells were observed. By contrast, cells in random collagen scaffold were disorder. CONCLUSION: Parallel collagen scaffold can induce cells to be in spindly and parallel arrangement, and promote parallel extracellular matrix formation; while random collagen scaffold can induce cells in random arrangement. The results indicate that parallel collagen scaffold is an ideal structure to promote tendon repairing.

[Fabrication of bioactive tissue engineering scaffold for reconstructing calcified cartilage layer based on three-dimension printing technique].

OBJECTIVE: To fabricate organic-inorganic composite tissue engineering scaffolds for reconstructing calcified cartilage layer based on three-dimensional (3D) printing technique. METHODS: The scaffolds were developed by 3D-printing technique with highly bioactive calcium-magnesium silicate ultrafine particles of 1%, 3% and 5% of mass fraction, in which the organic phases were composed of type I collagen and sodium hyaluronate. The 3D-printed scaffolds were then crosslinked and solidified by alginate and CaCl2 aerosol. The pore size and distribution of inorganic phase were observed with scanning electron microscope (SEM); the mechanical properties were tested with universal material testing machine, and the porosity of scaffolds was also measured. RESULTS: Pore size was approximately (212.3 ± 34.2) µm with a porosity of (48.3 ± 5.9)%, the compressive modulus of the scaffolds was (7.2 ± 1.2) MPa, which was irrelevant to the percentage changes of calcium-magnesium silicate, the compressive modulus was between that of cartilage and subchondral bone. CONCLUSION: The porous scaffolds for calcified cartilage layer have been successfully fabricated, which would be used for multi-layered composite scaffolds in osteochondral injury.

Cartilage repair using mesenchymal stem cell (MSC) sheet and MSCs-loaded bilayer PLGA scaffold in a rabbit model.

PURPOSE: The integration of regenerated cartilage with surrounding native cartilage is a major challenge for the success of cartilage tissue-engineering strategies. The purpose of this study is to investigate whether incorporation of the power of mesenchymal stem cell (MSC) sheet to MSCs-loaded bilayer poly-(lactic-co-glycolic acid) (PLGA) scaffolds can improve the integration and repair of cartilage defects in a rabbit model. METHODS: Rabbit bone marrow-derived MSCs were cultured and formed cell sheet. Full-thickness cylindrical osteochondral defects (4 mm in diameter, 3 mm in depth) were created in the patellar groove of 18 New Zealand white rabbits and the osteochondral defects were treated with PLGA scaffold (n = 6), PLGA/MSCs (n = 6) or MSC sheet-encapsulated PLGA/MSCs (n = 6). After 6 and 12 weeks, the integration and tissue response were evaluated histologically. RESULTS: The MSC sheet-encapsulated PLGA/MCSs group showed significantly more amounts of hyaline cartilage and higher histological scores than PLGA/MSCs group and PLGA group (P < 0.05). In addition, the MSC sheet-encapsulated PLGA/MCSs group showed the best integration between the repaired cartilage and surrounding normal cartilage and subchondral bone compared to other two groups. CONCLUSIONS: The novel method of incorporation of MSC sheet to PLGA/MCSs could enhance the ability of cartilage regeneration and integration between repair cartilage and the surrounding cartilage. Transplantation of autologous MSC sheet combined with traditional strategies or cartilage debris might provide therapeutic opportunities for improving cartilage regeneration and integration in humans.

Comparison of the ability of exosomes and ectosomes derived from adipose-derived stromal cells to promote cartilage regeneration in a rat osteochondral defect model.

BACKGROUND: Extracellular vesicles (EVs) derived from mesenchymal stromal cells (MSCs) offer promising prospects for stimulating cartilage regeneration. The different formation mechanisms suggest that exosomes and ectosomes possess different biological functions. However, little attention has been paid to the differential effects of EV subsets on cartilage regeneration. METHODS: Our study compared the effects of the two EVs isolated from adipose-derived MSCs (ASCs) on chondrocytes and bone marrow-derived MSCs (BMSCs) in vitro. Additionally, we loaded the two EVs into type I collagen hydrogels to optimize their application for the treatment of osteochondral defects in vivo. RESULTS: In vitro experiments demonstrate that ASC-derived exosomes (ASC-Exos) significantly promoted the proliferation and migration of both cells more effectively than ASC-derived ectosomes (ASC-Ectos). Furthermore, ASC-Exos facilitated a stronger differentiation of BMSCs into chondrogenic cells than ASC-Ectos, but both inhibited chondrocyte apoptosis to a similar extent. In the osteochondral defect model of rats, ASC-Exos promoted cartilage regeneration in situ better than ASC-Ectos. At 8 weeks, the hydrogel containing exosomes group (Gel + Exo group) had higher macroscopic and histological scores, a higher value of trabecular bone volume fraction (BV/TV), a lower value of trabecular thickness (Tb.Sp), and a better remodeling of extracellular matrix than the hydrogel containing ectosomes group (Gel + Ecto group). At 4 and 8 weeks, the expression of CD206 and Arginase-1 in the Gel + Exo group was significantly higher than that in the Gel + Ecto group. CONCLUSION: Our findings indicate that administering ASC-Exos may be a more effective EV strategy for cartilage regeneration than the administration of ASC-Ectos.

Advances in Hydrogels for Meniscus Tissue Engineering: A Focus on Biomaterials, Crosslinking, Therapeutic Additives.

Meniscus tissue engineering (MTE) has emerged as a promising strategy for meniscus repair and regeneration. As versatile platforms, hydrogels have gained significant attention in this field, as they possess tunable properties that allow them to mimic native extracellular matrices and provide a suitable microenvironment. Additionally, hydrogels can be minimally invasively injected and can be adjusted to match the shape of the implant site. They can conveniently and effectively deliver bioactive additives and demonstrate good compatibility with other functional materials. These inherent qualities have made hydrogel a promising candidate for therapeutic approaches in meniscus repair and regeneration. This article provides a comprehensive review of the advancements made in the research on hydrogel application for meniscus tissue engineering. Firstly, the biomaterials and crosslinking strategies used in the formation of hydrogels are summarized and analyzed. Subsequently, the role of therapeutic additives, including cells, growth factors, and other active products, in facilitating meniscus repair and regeneration is thoroughly discussed. Furthermore, we summarize the key issues for designing hydrogels used in MTE. Finally, we conclude with the current challenges encountered by hydrogel applications and suggest potential solutions for addressing these challenges in the field of MTE. We hope this review provides a resource for researchers and practitioners interested in this field, thereby facilitating the exploration of new design possibilities.

Self-adaptive pyroptosis-responsive nanoliposomes block pyroptosis in autoimmune inflammatory diseases.

Nanoliposomes have a broad range of applications in the treatment of autoimmune inflammatory diseases because of their ability to considerably enhance drug transport. For their clinical application, nanoliposomes must be able to realize on-demand release of drugs at disease sites to maximize drug-delivery efficacy and minimize side effects. Therefore, responsive drug-release strategies for inflammation treatment have been explored; however, no specific design has been realized for a responsive drug-delivery system based on pyroptosis-related inflammation. Herein, we report a pioneering strategy for self-adaptive pyroptosis-responsive liposomes (R8-cardiolipin-containing nanoliposomes encapsulating dimethyl fumarate, RC-NL@DMF) that precisely release encapsulated anti-pyroptotic drugs into pyroptotic cells. The activated key pyroptotic protein, the N-terminal domain of gasdermin E, selectively integrates with the cardiolipin of liposomes, thus forming pores for controlled drug release, pyroptosis, and inflammation inhibition. Therefore, RC-NL@DMF exhibited effective therapeutic efficacies to alleviate autoimmune inflammatory damages in zymosan-induced arthritis mice and dextran sulfate sodium-induced inflammatory bowel disease mice. Our novel approach holds great promise for self-adaptive pyroptosis-responsive on-demand drug delivery, suppressing pyroptosis and treating autoimmune inflammatory diseases.

Combined treatment with platelet-rich plasma and brain-derived neurotrophic factor-overexpressing bone marrow stromal cells supports axonal remyelination in a rat spinal cord hemi-section model.

BACKGROUND AIMS: Combining biologic matrices is becoming a better choice to advance stem cell-based therapies. Platelet-rich plasma (PRP) is a biologic product of concentrated platelets and has been used to promote regeneration of peripheral nerves after injury. We examined whether PRP could induce rat bone marrow stromal cells (BMSCs) differentiation in vitro and whether a combination of BMSCs, PRP and brain-derived neurotrophic factor (BDNF) could provide additive therapeutic benefits in vivo after spinal cord injury (SCI). METHODS: BMSCs and BDNF-secreting BMSCs (BDNF-BMSCs) were cultured with PRP for 7 days and 21 days, respectively, and neurofilament (NF)-200, glial fibrillary acidic protein (GFAP), microtubule-associated protein 2 (MAP2) and ribosomal protein S6 kinase (p70S6K) gene levels were assessed. After T10 hemi-section in 102 rats, 15-µL scaffolds (PRP alone, BMSCs, PRP/BMSCs, BDNF-BMSCs or PRP/BDNF-BMSCs) were transplanted into the lesion area, and real-time polymerase chain reaction, Western blot, immunohistochemistry and ultrastructural studies were performed. RESULTS: The messenger RNA expression of NF-200, GFAP, MAP2 and p70S6K was promoted in BMSCs and BDNF-BMSCs after culture with PRP in vitro. BDNF levels were significantly higher in the injured spinal cord after implantation of BDNF-BMSCs. In the PRP/BDNF-BMSCs group at 8 weeks postoperatively, more GFAP was observed, with less accumulation of astrocytes at the graft-host interface. Rats that received PRP and BDNF-BMSC implants showed enhanced hind limb locomotor performance at 8 weeks postoperatively compared with control animals, with more axonal remyelination. CONCLUSIONS: A combined treatment comprising PRP and BDNF-overexpressing BMSCs produced beneficial effects in rats with regard to functional recovery after SCI through enhancing migration of astrocytes into the transplants and axonal remyelination.

Relationship of the subscapular nerves to the base of the coracoid.

PURPOSE: This study was performed to determine the relation of the subscapular nerves to the medial base of the coracoid when using an arthroscopic approach. METHODS: Twenty human cadaveric shoulder specimens were dissected, and measurements were taken from the medial base of the coracoid to the innervation points of the upper and lower subscapular nerves. Measurements were obtained with the humerus in both neutral and maximal external rotation. RESULTS: The average distance of the upper subscapular nerve from the coracoid base was 31.6 ± 6.6 mm (range, 22 to 45 mm) in neutral rotation and 24.2 ± 7.4 mm (range, 11 to 35 mm) in external rotation. The lower subscapular nerve's insertion point averaged 42.6 ± 7.6 mm (range, 25 to 55 mm) from the coracoid base in neutral rotation and 33.9 ± 6.9 mm (range, 24 to 45 mm) in external rotation. For both nerves, their distance from the coracoid significantly decreased when the humerus was placed in external rotation. CONCLUSIONS: The closest that the innervation point of either the upper or lower subscapular nerve came to the medial aspect of the coracoid was 11 mm. CLINICAL RELEVANCE: Understanding the relationship of the subscapular nerves to the base of the coracoid allows a safe arthroscopic release of a retracted subscapularis muscle that has formed adhesions to the inferior aspect of the coracoid. Use of an arthroscopic elevator to release adhesions between the subscapularis and the inferior aspect of the coracoid does not appear to risk denervation of the subscapularis muscle.

Impact of sleep-wake features on fatigue among female shift work nurses.

BACKGROUND: Sleep disturbance and fatigue are prevalent in nurses. Little is known about the characteristics of shift work nurses' sleep-wake features and their subsequent impact on work performance. The study aimed to describe the characteristics of the sleep-wake index, reaction time, saliva cortisol level, and fatigue severity among female shift work nurses. METHODS: This is a cross-sectional exploratory study. A convenience sample of 152 female nurses (8-hour day-evening-night, n = 70; 12-hour day-night, n = 82) participated in this study from nine intensive care units (ICUs) from two teaching hospitals in Beijing, China. A consecutive 7-day actigraphy data were used to analyse sleep-wake indexes, including total sleep time (TST) and circadian activity rhythms (CAR). Before and after shifts, the following data were collected, psychomotor vigilance task for reaction time, saliva cortisol for the level of alertness, and self-reported fatigue severity with the Lee Fatigue Scale-Short Form. RESULTS: All nurses reported clinically significant fatigue severity. Compared with the 8-hour shift nurses, the 12-hour shift nurses had significantly more TST (456 vs. 364 min), higher saliva cortisol levels before the day shift (0.54 vs. 0.31), but longer reaction time before the night shift (286 vs. 277 ms). In both shifts, those with better CAR had significantly longer TST. CONCLUSION: Female nurses experienced fatigue and desynchronized CAR, especially nurses on a 12-hour shift. The CAR-friendly shift work schedule is needed to minimize the health and safety impacts of circadian misalignment for nurses.Key messagesThis is the first use of consecutive 7-day actigraphy data to explore the link between sleep disturbances as a stressor to CAR, salivary cortisol, and reaction time among clinical nurses.CAR may be a helpful indicator for overworked nurses, and it can serve as a modifiable target for interventions to enhance nurses' well-being.

Effects of retrograde gene transfer of brain-derived neurotrophic factor in the rostral spinal cord of a compression model in rat.

Recovery after spinal cord injury (SCI) is rare in humans and experimental animals. Following SCI in adults, changes in gene expression and the regulation of these genes are associated with the pathological development of the injury. High levels of brain-derived neurotrophic factor (BDNF) in the injury area during the post-injury period contribute to enhanced neuroprotection and axonal regeneration. Intervention at the level of gene regulation has the potential to promote SCI repair. In this study, the injection of adenovirus-mediated BDNF in the lesion area (rostral spinal cord) up-regulated the expression of BDNF in the injury zone of a compression model in rat, thereby protecting neurons and enhancing behavioral function.

Anatomy of the biceps tendon: implications for restoring physiological length-tension relation during biceps tenodesis with interference screw fixation.

PURPOSE: The purpose of this study was to characterize the normal length and diameter of the long head of the biceps tendon (BT) to provide guidelines for interference screw tenodesis. METHODS: Twenty-one cadaveric shoulders were dissected. The BT length was measured from its origin to the humeral head articular margin (AM), lower subscapularis, upper pectoralis major, musculotendinous junction of the biceps (MTJ), and lower pectoralis major (LPM). Tendon diameter was measured at levels corresponding to tenodesis: (1) at the AM, (2) suprapectorally, and (3) subpectorally. RESULTS: The mean tendon length was 24.9 mm from the origin to the AM, 56.1 mm to the lower subscapularis, 73.8 mm to the upper pectoralis major, 98.5 mm to the MTJ, and 118.4 mm to the LPM. The mean tendon diameter was 6.6 mm for tenodesis at the AM, 5.1 mm for suprapectoral tenodesis, and 5.3 mm for subpectoral tenodesis. During biceps tenodesis with interference screw fixation, restoring the normal length-tension relation of the BT depends on the site of tenodesis and the depth of the bone socket. At the AM, a 25-mm bone socket on average will maintain the length-tension relation. For tenodesis more distally, the length of tendon resection varies with bone socket length. Because the MTJ is above the LPM, subpectoral tenodesis should be performed proximal to the LPM. CONCLUSIONS: This study provides guidelines for restoring the normal length-tension relation during biceps tenodesis with interference screw fixation. The simplest way to restore this relation is with tenodesis adjacent to the humeral head AM and a bone socket of 25 mm in depth. For tenodesis at more distal locations, both the length of the BT and the depth of the bone socket must be considered. CLINICAL RELEVANCE: Information about the normal BT may be useful in preserving the physiological length-tension relation during biceps tenodesis.

Anatomic double-bundle anterior cruciate ligament reconstruction.

OBJECTIVE: To retrospectively evaluate the early results of anatomic double-bundle anterior cruciate ligament (ACL) reconstruction and compare with the results of native ACL of the contralateral knee. METHODS: The results of a consecutive series of 118 patients receiving arthroscopic ACL reconstruction were evaluated. Eight patients were lost to the latest follow-up, leaving a total of 110 patients available for study within at least 3 years'clinical follow-up. Among them, 63 patients underwent postoperative MRI and CT scan, as well as clinical evaluation. RESULTS: After reconstruction, the knees were stable and pain-free. Mean postoperative Lysholm score was 95.54 in 110 patients after 3 years. CT and MRI assessment showed that the reconstruction centered in the femoral footprint of ACL (n equal to 63). The sagittal ACL angle in the reconstructed ACL (52.16 degree+/-2.45 degree was much close to that in the contralateral intact ACL (51.31 degree +/-2.18 degree, P larger than 0.05). By ACL-Blumensaat line angle analysis, there was no difference between double-bundle reconstructed knees and their contralateral normal knees (4.67 degree+/-0.43 degree vs. 4.62 degree+/-0.60degree, P larger than 0.05). CONCLUSION: Anatomic double-bundle ACL reconstruction can place grafts more precisely in the anatomic footprint of the ACL and better restore knee kinematics.

A needle deflection model with operating condition optimization for corrective force-based needle guidance during transrectal prostate brachytherapy.

BACKGROUND: Transrectal prostate brachytherapy (BT) involves the permanent implantation of radioactive seeds through a needle, which must be inserted along a straight path to satisfy dose distribution requirements. However, this process is complicated by bevelled needle tips that can cause deflection during penetration. In clinical practice, physicians typically rotate the bevelled tip intermittently or apply manual correction forces near the insertion point, to reduce needle deflection. While assisted rotational insertion robots have made substantial progress in the past 20 years, tissue sticking can be caused by rotation of the bevelled tip and there are currently few studies on the use of corrective forces. As such, an auxiliary needle insertion guide for transrectal prostate BT, based on corrective forces, is investigated in this study for the first time. METHODS: The proposed BT guide is designed to reduce needle deflection and was experimentally verified by in vitro experiments. An energy-based deflection model was developed to predict needle motion as corrective forces were applied during insertion. An experimental platform was constructed to perform corrective force-assisted punctures, using the magnitude of the corrective force (A), the position of corrective force application (B) and the puncture speed (C) as test factors, with needle deflection as a test indicator. Design-Expert 8.0.5b software was used for simulation, and a high-definition camera acquired pictures of the needle tip as it pierced the tissue. A regression equation was also established for the test factors and test indicators, using Design-Expert software. Optimal parameter combinations (A, B and C) were determined through optimization. RESULTS: Calculated needle deflection values were then compared with the measured position of the needle insertion point, producing an average error of 0.39 ± 0.28 mm. Deflection was as low as 0.8 mm using optimal puncture parameters CONCLUSIONS: A needle-tissue interaction model, considering tissue nonlinearity, which experimental results demonstrated to be highly accurate. Optimal puncture parameters effectively improved puncture accuracy.

Review of research on path planning and control methods of flexible steerable needle puncture robot.

In the field of minimally invasive interventional therapy, the related research on the soft tissue puncture robot and its technology based on the flexible steerable needle as a research hot topic at present, and it has been developed rapidly in the past ten years. In order to better understand the development status of the flexible steerable needle puncture (FSNP) robot and provide reference for its design and improvement in subsequent research, it is necessary to introduce in two aspects of FSNP robot: the puncture path planning and the control methods. First, this article introduced the concept of the FSNP technology, and the necessity of the application of FSNP soft tissue robot in minimally invasive interventional surgery. Second, this article mainly introduced the principle of FSNP, the path planning of FSNP, the navigation and positioning control of the needle tip of the flexible steerable needle, the control method of FSNP system, and the controllable flexible needle. Finally, combined with the above analysis and introduction, it was pointed out that FSNP soft tissue robot and its related technology would be an important development direction in the field of minimally invasive interventional therapy in the future, and the current existing problems were pointed out. Meanwhile, the development trend of FSNP robot control technology was summarized and prospected.

A Modified Reptile Search Algorithm for Numerical Optimization Problems.

The reptile search algorithm (RSA) is a swarm-based metaheuristic algorithm inspired by the encirclement and hunt mechanisms of crocodiles. Compared with other algorithms, RSA is competitive but still suffers from low population diversity, unbalanced exploitation and exploration, and the tendency to fall into local optima. To overcome these shortcomings, a modified variant of RSA, named MRSA, is proposed in this paper. First, an adaptive chaotic reverse learning strategy is employed to enhance the population diversity. Second, an elite alternative pooling strategy is proposed to balance exploitation and exploration. Finally, a shifted distribution estimation strategy is used to correct the evolutionary direction and improve the algorithm performance. Subsequently, the superiority of MRSA is verified using 23 benchmark functions, IEEE CEC2017 benchmark functions, and robot path planning problems. The Friedman test, the Wilcoxon signed-rank test, and simulation results show that the proposed MRSA outperforms other comparative algorithms in terms of convergence accuracy, convergence speed, and stability.

Comparative Effects of Exosomes and Ectosomes Isolated From Adipose-Derived Mesenchymal Stem Cells on Achilles Tendinopathy in a Rat Model.

BACKGROUND: Extracellular vesicles derived from mesenchymal stem cells (MSC-EVs) have gained momentum as a treatment for tendinopathy. Multiple studies have demonstrated significant differences in cargo composition between the 2 subtypes of MSC-EVs (ie, exosomes and ectosomes), which may result in different therapeutic effects. However, the effects of the 2 EV subtypes on tendinopathy have not yet been compared. PURPOSE: To compare the effects of adipose stem cell-derived exosomes (ASC-Exos) and ectosomes (ASC-Ectos) on Achilles tendinopathy. STUDY DESIGN: Controlled laboratory study. METHODS: Rats were administered collagenase injections to generate a model of Achilles tendinopathy. A week later, 36 rats were randomly assigned to 3 groups. In each group, Achilles tendons were injected with equal volumes of ASC-Exos, ASC-Ectos, or saline (12 legs/group). The healing outcomes were evaluated by magnetic resonance imaging, histology, immunohistochemistry, transmission electron microscopy, and biomechanical testing at 3 and 5 weeks after collagenase injection. RESULTS: At 3 and 5 weeks, the ASC-Exo group had better histological scores (P = .0036 and P = .0276, respectively), a lower fibril density (P < .0001 and P = .0310, respectively), and a larger collagen diameter (P = .0052 and P < .0001, respectively) than the ASC-Ecto group. At 5 weeks, the expression of collagen type 1 and CD206 in the ASC-Exo group was significantly higher than that in the ASC-Ecto group (P = .0025 and P = .0010, respectively). Regarding biomechanical testing, the ASC-Exo group showed higher failure load (P = .0005), tensile stress (P < .0001), and elastic modulus (P < .0001) than the ASC-Ecto group. CONCLUSION: ASC-Exos had more beneficial effects on tendon repair than ASC-Ectos in a rat model of Achilles tendinopathy. CLINICAL RELEVANCE: Administration of ASC-EVs may have the potential to treat Achilles tendinopathy, and delivery of ASC-Exos could provide additional benefits. It is necessary to compare the healing responses caused by different EV subtypes to further understand their effects on tendinopathy and to aid clinical decision making.

[Intermediate outcomes of alumina-on-alumina bearing total hip arthroplasty].

OBJECTIVE: To explore the intermediate outcomes of third-generation alumina-on-alumina total hip arthroplasty (THA). METHODS: A consecutive series of 165 primary alumina-on-alumina total hip arthroplasties were performed in 135 patients. Three patients died and 13 patients lost follow-up so that a total of 119 patients (146 hips) were available for study. The mean patient age was 53.4 ± 11.0 years old (range: 26 - 79). Hydroxyapatite. (HA)-coated press-fit acetabular cups were used in all cases. At femoral side, 123 cases were implanted with HA-coated uncemented stems and 23 cases implanted with high polished double taped cemented stems. All patients were evaluated clinically and radiographically after a minimal follow-up duration of 60 months. RESULTS: The preoperative mean Harris hip score of 49.6 ± 7.9 points improved to 91.7 ± 3.0 points at the last follow-up (P < 0.05). The 5-year survival for any reason lead to revision was 96.6%. Five hips were under revision, 1 for acetabular shell loosening and migration, 1 for Vancouver B2 periprosthetic fracture, 1 for fracture of pure alumina liner and 2 for infections. All other prostheses demonstrated no radiographic evidence of loosening. No periprosthetic osteolysis was found. There were 2 cases of dislocations and 2 patients presented postoperatively with "squeaking-like" hips. CONCLUSION: The clinical and radiographic outcomes after primary THA with third-generation ceramic-on-ceramic bearing surfaces are favorable after a minimal follow-up duration of 5 years. The modified alumina-on-alumina bearing implants offer a better option for younger and active patients.

Image-guided robots for low dose rate prostate brachytherapy: Perspectives on safety in design and use.

BACKGROUND: Image-guided brachytherapy (BT) robots can be used to assist urologists during seed implantation, thereby improving therapeutic effects. However, safety issues must be considered in the design of such robots, including their structure, mechanical movements, function, materials and actuators. Previous reviews focused on image-guided prostate BT robot technology (e.g., imaging and robot navigation technology and robot system introduction); however, this review is the first time that safety issues have been investigated as part of a study on low-dose-rate (LDR) prostate BT robots. METHODS: Multiple electronic databases were searched for LDR prostate BT robot articles published during the last 24 years (1996-2020), with a particular focus on two aspects of robots: safety in design and use. RESULTS: We retrieved a total of 26 LDR prostate BT robots. BT robots were divided into ultrasound, computed tomography, magnetic resonance imaging and fusion-guided systems. The conditions associated with each system were then analysed to develop a set of requirements for the safety of prostate BT robots. Recommendations are also provided for future BT robot development. CONCLUSIONS: The transrectal approach for prostate seed implantation is safer than the traditional transperineal approach. Research into the control of a steerable needle by the urologists and robot, the needle deflection model, and robotic automated needle changing and seed injection equipment should be pursued in a future study.

Short- to Midterm Clinical and Radiological Outcomes After Matrix-Associated Autologous Chondrocyte Implantation for Chondral Defects in Knees.

BACKGROUND: Matrix-associated autologous chondrocyte implantation (MACI) has been proven to provide favorable short-term results for chondral defects in knees. However, it remains unclear whether the clinical benefits of MACI persist in the longer term. PURPOSE: The purpose of this prospective study was to evaluate the clinical and radiological outcomes, at short- and midterm follow-up, for patients undergoing MACI for focal chondral defects of the knee. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A total of 30 consecutive patients (31 knees) were treated using MACI between October 2010 and March 2018. There were 24 male patients and 6 female patients with an average age of 26 years (range, 12-48 years). The areas of the cartilage defect were consistently >2 cm2. All patients underwent MACI for a focal chondral defect of the femoral condyles or trochlea in the knee. These patients had been evaluated for up to 5 years, with an average follow-up of 44 months (range, 6-60 months) postoperatively.The International Knee Documentation Committee (IKDC) score, Lysholm score, and magnetic resonance imaging (MRI) with T2 mapping were used to assess the outcomes. RESULTS: No patients were lost to follow-up. Mean IKDC scores improved from 58.6 (range, 40.2-80.5) to 79.1 (range, 39.1-94.3) at 12 months and up to 88.4 (range, 83.9-100) at 5 years; mean Lysholm scores improved from 67.3 (range, 46-95) to 90.6 (range, 71-100) at 12 months and up to 95.9 (range, 85-100) at 5 years. The MRI with T2 mapping value of the transplanted area was evaluated for 21 knees, which revealed no differences compared with the normal area at 12 months postoperatively. CONCLUSION: From the first year onward, the clinical outcome scores and MRI with T2 mapping values showed continuous and marked improvement, suggesting that MACI is a valid option for localized cartilage defects in the knee.