Biochemical and Cellular Assessment of Acetabular Chondral Flaps Identified During Hip Arthroscopy.
OBJECTIVE
To analyze chondral flaps debrided during hip arthroscopy to determine their biochemical and cellular composition.


METHODS
Thirty-one full-thickness acetabular chondral flaps were collected during hip arthroscopy. Biochemical analysis was undertaken in 21 flaps from 20 patients, and cellular viability was determined in 10 flaps from 10 patients. Biochemical analysis included concentrations of (1) DNA (an indicator of chondrocyte content), (2) hydroxyproline (an indicator of collagen content), and (3) glycosaminoglycan (an indicator of chondrocyte biosynthesis). Higher values for these parameters indicated more healthy tissue. The flaps were examined to determine the percentage of viable chondrocytes.


RESULTS
The percentage of acetabular chondral flap specimens that had concentrations within 1 SD of the mean values reported in previous normal cartilage studies was 38% for DNA, 0% for glycosaminoglycan, and 43% for hydroxyproline. The average cellular viability of our acetabular chondral flap specimens was 39% (SD, 14%). Only 2 of the 10 specimens had more than half the cells still viable. There was no correlation between (1) the gross examination of the joint or knowledge of the patient's demographic characteristics and symptoms and (2) biochemical properties and cell viability of the flap, with one exception: a degenerative appearance of the surrounding cartilage correlated with a higher hydroxyproline concentration.


CONCLUSIONS
Although full-thickness acetabular chondral flaps can appear normal grossly, the biochemical properties and percentage of live chondrocytes in full-thickness chondral flaps encountered in hip arthroscopy show that this tissue is not normal.


CONCLUSIONS
There has been recent interest in repairing chondral flaps encountered during hip arthroscopy. These data suggest that acetabular chondral flaps are not biochemically and cellularly normal. Although these flaps may still be valuable mechanically and/or as a scaffold in some conductive or inductive capacity, further study is required to assess the clinical benefit of repair.
El Camino Hospital, Los Gatos, California, U.S.A.. Electronic address: doctorsanaz@me.com.
Sanaz
S
Hariri
Orthopaedic Research Laboratories, Stanford University School of Medicine, Stanford, California, U.S.A.
Jeremy
J
Truntzer
Orthopaedic Research Laboratories, Stanford University School of Medicine, Stanford, California, U.S.A.
Robert Lane
RL
Smith
Division of Sports Medicine, Department of Orthopaedic Surgery, Stanford University, Redwood City, California, U.S.A.
Marc R
MR
Safran
D000077:Acetabulum / Q000601:surgery; D000328:Adult; D001182:Arthroscopy / Q000379:methods*; D002357:Cartilage Diseases / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D002358:Cartilage, Articular / Q000737:chemistry* / Q000473:pathology / Q000601:surgery; D002470:Cell Survival; D019902:Chondrocytes / Q000473:pathology; D004247:DNA / Q000032:analysis; D005260:Female; D006025:Glycosaminoglycans / Q000032:analysis; D006621:Hip Joint / Q000473:pathology / Q000601:surgery*; D006801:Humans; D006909:Hydroxyproline / Q000032:analysis; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014945:Wound Healing
D006025:Glycosaminoglycans; D004247:DNA; D006909:Hydroxyproline