The Pathophysiology and Principles of Rehabilitation after Cartilage Injury

Abstract To determine interobserver and intraobserver reliabilities of the combination of classification systems, including the Beck and acetabular labral articular disruption (ALAD) systems for transition zone cartilage, the Outerbridge system for acetabular and femoral head cartilage, and the Beck system for labral tears. Additionally, we sought to determine interobserver and intraobserver agreements in the location of injury to labrum and cartilage. Three fellowship trained surgeons reviewed 30 standardized videos of the central compartment with one surgeon re-evaluating the videos. Labral pathology, transition zone cartilage and acetabular cartilage were classified using the Beck, Beck and ALAD systems, and Outerbridge system, respectively. The location of labral tears and transition zone cartilage injury was assessed using a clock face system, and acetabular cartilage injury using a five-zone system. Intra- and interobserver reliabilities are reported as Gwet’s agreement coefficients. Interobserver and intraobserver agreement on the location of acetabular cartilage lesions was highest in superior and anterior zones (0.814–0.914). Outerbridge interobserver and intraobserver agreement was >0.90 in most zones of the acetabular cartilage. Interobserver and intraobserver agreement on location of transition zone lesions was 0.844–0.944. The Beck and ALAD classifications showed similar interobserver and intraobserver agreement for transition zone cartilage injury. The Beck classification of labral tears was 0.745 and 0.562 for interobserver and intraobserver agreements, respectively. The Outerbridge classification had almost perfect interobserver and intraobserver agreement in classifying chondral injury of the true acetabular cartilage and femoral head. The Beck and ALAD classifications both showed moderate to substantial interobserver and intraobserver reliabilities for transition zone cartilage injury. The Beck system for classification of labral tears showed substantial agreement among observers and moderate intraobserver agreement. Interobserver agreement on location of labral tears was highest in the region where most tears occur and became lower at the anterior and posterior extents of this region. The available classification systems can be used for documentation regarding intra-articular pathology. However, continued development of a concise and highly reproducible classification system would improve communication.

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Digital Light Processing Bioprinted Human Chondrocyte-Laden Poly (γ-Glutamic Acid)/Hyaluronic Acid Bio-Ink towards Cartilage Tissue Engineering

Biomedicines ◽

10.3390/biomedicines9070714 ◽

2021 ◽

Vol 9 (7) ◽

pp. 714

Author(s):

Alvin Kai-Xing Lee ◽

Yen-Hong Lin ◽

Chun-Hao Tsai ◽

Wan-Ting Chang ◽

Tsung-Li Lin ◽

...

Keyword(s):

United States ◽

Tissue Engineering ◽

Hyaluronic Acid ◽

Glutamic Acid ◽

Cellular Proliferation ◽

Cartilage Tissue Engineering ◽

Cartilage Regeneration ◽

The United States ◽

Cartilage Injury ◽

Cartilage Tissue

Cartilage injury is the main cause of disability in the United States, and it has been projected that cartilage injury caused by osteoarthritis will affect 30% of the entire United States population by the year 2030. In this study, we modified hyaluronic acid (HA) with γ-poly(glutamic) acid (γ-PGA), both of which are common biomaterials used in cartilage engineering, in an attempt to evaluate them for their potential in promoting cartilage regeneration. As seen from the results, γ-PGA-GMA and HA, with glycidyl methacrylate (GMA) as the photo-crosslinker, could be successfully fabricated while retaining the structural characteristics of γ-PGA and HA. In addition, the storage moduli and loss moduli of the hydrogels were consistent throughout the curing durations. However, it was noted that the modification enhanced the mechanical properties, the swelling equilibrium rate, and cellular proliferation, and significantly improved secretion of cartilage regeneration-related proteins such as glycosaminoglycan (GAG) and type II collagen (Col II). The cartilage tissue proof with Alcian blue further demonstrated that the modification of γ-PGA with HA exhibited suitability for cartilage tissue regeneration and displayed potential for future cartilage tissue engineering applications. This study built on the previous works involving HA and further showed that there are unlimited ways to modify various biomaterials in order to further bring cartilage tissue engineering to the next level.

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