Arthroscopic utilization of ChondroFiller gel for the treatment of hip articular cartilage defects: a cohort study with 12- to 60-month follow-up

Outcomes of Arthroscopic Joint Preservation Techniques for Chondral Lesions in the Hip: An Updated Systematic Review

PURPOSE

To systematically review outcomes of joint preservation procedures for chondral lesions of the hip through analysis of survival rates and patient-reported outcomes (PROs).

METHODS

A literature search from 2018 to May 2023 was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines in 3 databases: PubMed, Embase, and Google Scholar. Studies were included if they reported on outcomes of patients undergoing hip arthroscopy for the treatment of chondral lesions of the hip joint and if there were quantifiable postoperative outcome measures. Quality assessment was completed using the Methodological Index for Non-Randomized Studies criteria.

RESULTS

Twenty-seven studies were included, with 20 noncomparative and 7 comparative studies. Microfracture (MFx) was the most common procedure, reported in 17 studies. Other procedures include autologous chondrocyte transplantation (ACT) (5 studies), autologous matrix-induced chondrogenesis (AMIC) (3 studies), and MFx in conjunction with CarGel (3 studies). Seven other novel procedures were reported in individual separate studies. Survival rates, defined by no revision surgery or conversion to total hip arthroscopy (THA) at latest follow-up, for MFx (14 studies), AMIC (3 studies), and MFx in conjunction with CarGel (3 studies) ranged from 59.1% to 100%, 92.9% to 100%, and 94.4% to 95.7%, respectively. Survival rates of ACT, biological reconstruction, debridement and abrasion, microfragmented autologous adipose tissue transplantation, and ChondroFiller gel were all reported once in separate studies with rates of 100%, 100%, 85.4%, 100%, and 92.3%, respectively. All studies included PROs, most reporting statistically significant improvements (P < .05) at the latest follow-up.

CONCLUSIONS

Isolated MFx remained the most commonly performed technique, but with lower survival and higher conversion to THA rates than in studies before 2018. Novel techniques that were performed in conjunction with MFx or that avoided MFx altogether had higher overall survival rates despite being minimally performed. Most patients across all techniques demonstrated significant improvements in PROs.

LEVEL OF EVIDENCE

Level IV, systematic review of Level III and IV studies.

In vitro and in vivo efficacy of naturally derived scaffolds for cartilage repair and regeneration

Intrinsically present bioactive cues allow naturally derived materials to mimic important characteristics of cartilage while also facilitating cellular recruitment, infiltration, and differentiation. Such traits are often what tissue engineers desire when they fabricate scaffolds, and yet, literature from the past decade is replete with examples of how most natural constructs with native biomolecules have only offered sub-optimal results in the treatment of cartilage defects. This paper provides an in-depth investigation of the performance of such scaffolds through a review of a collection of natural materials that have been used so far in repairing/regenerating articular cartilage. Although in vivo and clinical studies are the best indicators of scaffold efficacy, it was, however, observed that a large number of natural constructs had very promising scaffold characteristics to begin with, and would often show good in vitro/in vivo results. Finally, an examination of the biochemistry and biomechanics of repair tissues in studies that reported positive outcomes showed that these attributes often approached target cartilage values. The paper concludes with an outline of current trends as well as future directions for the field. STATEMENT OF SIGNIFICANCE: This review offers an exclusive focus on natural scaffold materials for cartilage repair and regeneration and provides a quantitative and qualitative analysis of their performance under a variety of in vitro and in vivo conditions. Readers can learn about environments where natural scaffolds have had the most success and tailor strategies to optimize their own work. Furthermore, given how the glycosaminoglycan (GAG) to hydroxyproline (HYP) ratio and moduli are fundamental attributes of hyaline cartilage, this paper adds to the body of knowledge by exploring how these characteristics reflect in preclinical outcomes. Such perspectives can greatly aid researchers better utilize natural materials for Cartilage Tissue Engineering (CTE).

Advances in Microgravity Directed Tissue Engineering

Tissue engineering aims to generate functional biological substitutes to repair, sustain, improve, or replace tissue function affected by disease. With the rapid development of space science, the application of simulated microgravity has become an active topic in the field of tissue engineering. There is a growing body of evidence demonstrating that microgravity offers excellent advantages for tissue engineering by modulating cellular morphology, metabolism, secretion, proliferation, and stem cell differentiation. To date, there have been many achievements in constructing bioartificial spheroids, organoids, or tissue analogs with or without scaffolds in vitro under simulated microgravity conditions. Herein, the current status, recent advances, challenges, and prospects of microgravity related to tissue engineering are reviewed. Current simulated-microgravity devices and cutting-edge advances of microgravity for biomaterials-dependent or biomaterials-independent tissue engineering to offer a reference for guiding further exploration of simulated microgravity strategies to produce engineered tissues are summarized and discussed.

Injectable hydrogels for articular cartilage and nucleus pulposus repair: Status quo and prospects

Osteoarthritis (OA) and chronic low back pain due to degenerative (intervertebral) disc disease (DDD) are two of the major causes of disabilities worldwide, affecting hundreds of millions of people and leading to a high socioeconomic burden. Although OA occurs in synovial joints and DDD occurs in cartilaginous joints, the similarities are striking, with both joints showing commonalities in the nature of the tissues and in the degenerative processes during disease. Consequently, repair strategies for articular cartilage (AC) and nucleus pulposus (NP), the core of the intervertebral disc, in the context of OA and DDD share common aspects. One of such tissue engineering approaches is the use of injectable hydrogels for AC and NP repair. In this review, the state-of-the-art and recent developments in injectable hydrogels for repairing, restoring, and regenerating AC tissue suffering from OA and NP tissue in DDD are summarized focusing on cell-free approaches. The various biomaterial strategies exploited for repair of both tissues are compared, and the synergies that could be gained by translating experiences from one tissue to the other are identified.