Distribution of bone mineral density at osteochondral donor sites in the patellofemoral joint among baseball players and controls.
BACKGROUND
To theoretically minimize complications of osteochondral graft harvest from the knee, grafts should be obtained from the site of lowest stress distribution across the joint.


OBJECTIVE
Long-term stress distribution over the patellofemoral (PF) joint surface is not equal in athletes.


METHODS
Cross-sectional study; Level of evidence, 3.


METHODS
Measurement of subchondral bone density can determine long-term resultant stress acting on an articular surface in living joints. Our analysis was performed using computed tomography (CT) image data obtained from bilateral knees of 10 college baseball fielders (fielder group) and 10 college baseball pitchers (pitcher group) and 2 control groups, including 10 college soccer players (soccer group) and 10 nonathletes (nonathlete group). The distribution pattern of subchondral bone density throughout the articular surface of the PF joint was assessed using the CT osteoabsorptiometry method. The quantitative analysis focused on the location of the low-density area at the articular surface to assess potential osteochondral donor sites.


RESULTS
All participants in the pitcher and fielder groups demonstrated a low-density area widely distributed in the proximal part of the lateral trochlea. On the other hand, a high-density area was located in the distal part of the lateral notch, of the medial notch, and of the medial trochlea. No apparent differences in the distribution pattern were found between the baseball groups and the control groups.


CONCLUSIONS
Our analysis, based on CT osteoabsorptiometry, indicates that the proximal lateral trochlea of the distal femur has the highest percentage area of low bone density at the PF joint level in donor knees of baseball players, soccer players, and nonathlete controls.


CONCLUSIONS
From a biomechanical viewpoint, the proximal lateral trochlea is the optimal site for harvesting osteochondral grafts in performing mosaicplasty for baseball players. This selection for the donor site may minimize postoperative PF joint symptoms.
Department of Orthopaedic Surgery, Hokkaido University School of Medicine, Sapporo, Japan.
Kinya
K
Nishida
Norimasa
N
Iwasaki
Kazuhiro
K
Fujisaki
Tadanao
T
Funakoshi
Tamotsu
T
Kamishima
Shigeru
S
Tadano
Akio
A
Minami
D000328:Adult; D056352:Athletes; D001484:Baseball; D015519:Bone Density; D003430:Cross-Sectional Studies; D006801:Humans; D007717:Knee / Q000000981:diagnostic imaging; D008297:Male; D014057:Tomography, X-Ray Computed; D060053:Transplant Donor Site; D055815:Young Adult