Viability assessment of the chondral flap in patients with cam-type femoroacetabular impingement: a preliminary report

Abstract

Background: Delaminated acetabular cartilage is a common finding in patients undergoing surgical dislocation or hip arthroscopy in the treatment of cam-type femoroacetabular impingement. Current treatment involves resection of the free cartilage flap with or without acetabular rim trimming. The viability of the delaminated cartilage flap is not known. We sought to examine if the acetabular cartilage still has viable cartilage cells and, if so, what type of cartilage is present. Methods:We examined the delaminated cartilage flaps from patients undergoing surgical dislocation and osteochondroplasty for symptomatic cam-type impingement. We performed hematoxylin and eosin staining and histological analysis using light microscopy to determine cartilage viability and cartilage type. Results:We examined 12 delaminated cartilage flaps from 11 patients (10 men, 1 woman, average age 30.1 yr). Ninety percent chondrocyte viability was confirmed in 11 of 12 flaps. Six of 12 flaps were composed predominantly of hyaline cartilage, 4 were a mixed population of fibrocartilage and hyaline cartilage and 2 were predominantly fibrocartilage. Conclusion:Our findings suggest that the delaminated cartilage flap in patients with femoroacetabular impingement may retain a large amount of viable chondrocytes. Development of surgical techniques focusing on refixation of this flap as an alternative to excision and microfracture should be considered.

Characterization of primary chondrocytes harvested from hips with femoroacetabular impingement

“…The extent of cell viability of primary human chondrocytes derived from the damaged hip areas was comparable to that reported by other studies. For instance, Meulenkamp et al found an overall viability of ninety percent in chondrocytes derived from delaminated cartilage flaps from patients with symptomatic camtype impingement which is in line with our findings 23 . Notably transport simulation, being a crucial prerequisite for clinical translation, did not affect cell viability.…”

Viability and Tissue Quality of Cartilage Flaps From Patients With Femoroacetabular Hip Impingement: A Matched-Control Comparison

“… 16 , 60 Unlike our study, the control samples used were animal articular cartilage and human knee cartilage, and no direct comparison of tissue viability and quality was made with the human acetabular articular cartilage surface. 16 In another study by Meulenkamp et al, 32 the reported cellular viability of 12 chondral flaps was higher, with an overall viability of 90%. This was measured from H&E-stained sections, which can overestimate viability, as suggested by the authors.…”

Viability Assessment of Chondrocytes Obtained from Flap Type Injuries in Patients with FAI

“…Under light microscopy a musculoskeletal pathologist assessed the cartilage viability and found more than 90% of viable chondrocytes in 11 out of 12 samples. In addition, they found that in 50% of the flaps the cartilage was predominantly hyaline [14].…”