OBJECTIVE: To standardize the operative procedure for tissue-engineered cartilage repair, by demonstrating surgical technique of arthroscopic implantation of decalcified cortex-cancellous bone scaffolds, and summarizing the surgical experience of the sports medicine department team at Peking University Third Hospital. METHODS: This article elaborates on surgical techniques and skills, focusing on the unabridged implantation technology and surgical procedure of decalcified cortex-cancellous bone scaffolds under arthroscopy: First, the patient was placed in the supine position. After anesthesia had been established, the surgeon established an arthroscope and explored the damaged area under the scope. After confirming the size and location of the injury site, the surgeon cleaned the damaged cartilage, and also trimmed the edges of the cartilage to ensure that the cut surface was smooth and stable. the surgeon performed the micro-fracture surgery in the area of cartilage injury, and then measured the size of the injured area under the scope. Next, the surgeon manually trimmed the tissue-engineered scaffold based on the measurements taken under the arthroscope, and then directly implanted the scaffold using a sleeve. A honeycomb-shaped fixator was used to implant absorbable nails to fix the scaffold. After the scaffold was installed, the knee was repeatedly flexed and extended for 10-20 times to ensure stability and range of motion. Finally, the arthroscope was withdrawn and the wound was closed. RESULTS: Decalcified cortex-cancellous bone scaffolds possessed unparalleled advantages over synthetic materials in terms of morphology and biomechanics. The cancellous bone part of the scaffold provided a three-dimensional, porous space for cell growth, while the cortical bone part offered the necessary mechanical strength. The surgery was performed entirely under arthroscopy to minimize invasiveness to the patient. Absorbable pins were used for fixation to ensure the stability of the scaffold. This technique could effectively improve the prognosis of the patients with cartilage injuries and standardized the surgical procedures for arthroscopic tissue-engineered scaffold operations in the patients with cartilage damage. CONCLUSION With the standard arthroscopic tissue-engineered scaffold repair technique, it is possible to successfully repair damaged cartilage, alleviate symptoms in the short term, and provide a more ideal long-term prognosis. The author and their team explain the surgical procedures for tissue-engineered scaffolds under arthroscopy, with the aim of guiding future clinical practice.
Tissue Engineering/methods* ; Humans ; Tissue Scaffolds ; Arthroscopy/methods* ; Cartilage, Articular/surgery*

Objective The study aimed to investigate the impact of rare earth elements(REEs)exposure on pregnancy outcomes of in vitro fertilization-embryo transfer(IVF-ET)by analyzing samples from spouses. Methods A total of 141 couples were included.Blood and follicular fluid from the wives and semen plasma from the husbands,were analyzed for REEs using inductively coupled plasma mass spectrometry(ICP-MS).Spearman's correlation coefficients and the Mann-Whitney U test were used to assess correlations and compare REE concentrations among three types of samples,respectively.Logistic models were utilized to estimate the individual REE effect on IVF-ET outcomes,while BKMR and WQS models explored the mixture of REE interaction effects on IVF-ET outcomes. Results Higher La concentration in semen(median 0.089 ng/mL,P=0.03)was associated with a lower fertilization rate.However,this effect was not observed after artificial selection intervention through intracytoplasmic sperm injection(ICSI)(P=0.27).In semen,the REEs mixture did not exhibit any significant association with clinical pregnancy. Conclusion Our study revealed a potential association between high La exposure in semen and a decline in fertilization rate,but not clinical pregnancy rate.This is the first to report REEs concentrations in follicular fluid with La,Ce,Pr,and Nd found at significantly lower concentrations than in serum,suggesting that these four REEs may not accumulate in the female reproductive system.However,at the current exposure levels,mixed REEs exposure did not exhibit reproductive toxicity.