What Components Comprise the Measurement of the Tibial Tuberosity-Trochlear Groove Distance in a Patellar Dislocation Population?
BACKGROUND
The tibial tuberosity-trochlear groove distance is used as an indicator for medial tibial tubercle transfer; however, to our knowledge, no studies have verified whether this distance is strongly affected by tubercle lateralization at the proximal part of the tibia. We hypothesized that the tibial tuberosity-trochlear groove distance is mainly affected by tibial tubercle lateralization at the proximal part of the tibia.


METHODS
Forty-four patients with a history of patellar dislocation and forty-four age and sex-matched controls were analyzed with use of computed tomography. The tibial tuberosity-trochlear groove distance, tibial tubercle lateralization, trochlear groove medialization, and knee rotation were measured and were compared between the patellar dislocation group and the control group. The association between the tibial tuberosity-trochlear groove distance and three other parameters was calculated with use of the Pearson correlation coefficient and partial correlation analysis.


RESULTS
There were significant differences in the tibial tuberosity-trochlear groove distance (p < 0.001) and knee rotation (p < 0.001), but there was no difference in the tibial tubercle lateralization (p = 0.13) and trochlear groove medialization (p = 0.08) between the patellar dislocation group and the control group. The tibial tuberosity-trochlear groove distance had no linear correlation with tubercle lateralization (r = 0.21) or groove medialization (r = -0.15); however, knee rotation had a good positive correlation in the patellar dislocation group (r = 0.62). After adjusting for the remaining parameters, knee rotation strongly correlated with the tibial tuberosity-trochlear groove distance (r = 0.69, p < 0.001), whereas tubercle lateralization showed moderate significant correlations in the patellar dislocation group (r = 0.42; p = 0.005).


CONCLUSIONS
Because the tibial tuberosity-trochlear groove distance is affected more by knee rotation than by tubercle malposition, its use as an indicator for tibial tubercle transfer may not be appropriate.


CONCLUSIONS
Surgical decisions of tibial tubercle transfer should be made after the careful analysis of several underlying factors of patellar dislocation.
Department of Orthopedic Surgery (K.T., Y.A., H.S., S.T., S.I., and H.K.) and Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research (N.S.), Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan. E-mail address for K. Tensho: kten@shinshu-u.ac.jp. E-mail address for Y. Akaoka: zebrawoodc@shinshu-u.ac.jp. E-mail address for H. Shimodaira: shimohei4792@yahoo.co.jp. E-mail address for S. Takanashi: seijit@shinshu-u.ac.jp. E-mail address for S. Ikegami: ikegamish@shinshu-u.ac.jp. E-mail address for H. Kato: hirokato@shinshu-u.ac.jp. E-mail address for N. Saito: saitoko@shinshu-u.ac.jp.
Keiji
K
Tensho
Department of Orthopedic Surgery (K.T., Y.A., H.S., S.T., S.I., and H.K.) and Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research (N.S.), Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan. E-mail address for K. Tensho: kten@shinshu-u.ac.jp. E-mail address for Y. Akaoka: zebrawoodc@shinshu-u.ac.jp. E-mail address for H. Shimodaira: shimohei4792@yahoo.co.jp. E-mail address for S. Takanashi: seijit@shinshu-u.ac.jp. E-mail address for S. Ikegami: ikegamish@shinshu-u.ac.jp. E-mail address for H. Kato: hirokato@shinshu-u.ac.jp. E-mail address for N. Saito: saitoko@shinshu-u.ac.jp.
Yusuke
Y
Akaoka
Department of Orthopedic Surgery (K.T., Y.A., H.S., S.T., S.I., and H.K.) and Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research (N.S.), Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan. E-mail address for K. Tensho: kten@shinshu-u.ac.jp. E-mail address for Y. Akaoka: zebrawoodc@shinshu-u.ac.jp. E-mail address for H. Shimodaira: shimohei4792@yahoo.co.jp. E-mail address for S. Takanashi: seijit@shinshu-u.ac.jp. E-mail address for S. Ikegami: ikegamish@shinshu-u.ac.jp. E-mail address for H. Kato: hirokato@shinshu-u.ac.jp. E-mail address for N. Saito: saitoko@shinshu-u.ac.jp.
Hiroki
H
Shimodaira
Department of Orthopedic Surgery (K.T., Y.A., H.S., S.T., S.I., and H.K.) and Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research (N.S.), Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan. E-mail address for K. Tensho: kten@shinshu-u.ac.jp. E-mail address for Y. Akaoka: zebrawoodc@shinshu-u.ac.jp. E-mail address for H. Shimodaira: shimohei4792@yahoo.co.jp. E-mail address for S. Takanashi: seijit@shinshu-u.ac.jp. E-mail address for S. Ikegami: ikegamish@shinshu-u.ac.jp. E-mail address for H. Kato: hirokato@shinshu-u.ac.jp. E-mail address for N. Saito: saitoko@shinshu-u.ac.jp.
Seiji
S
Takanashi
Department of Orthopedic Surgery (K.T., Y.A., H.S., S.T., S.I., and H.K.) and Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research (N.S.), Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan. E-mail address for K. Tensho: kten@shinshu-u.ac.jp. E-mail address for Y. Akaoka: zebrawoodc@shinshu-u.ac.jp. E-mail address for H. Shimodaira: shimohei4792@yahoo.co.jp. E-mail address for S. Takanashi: seijit@shinshu-u.ac.jp. E-mail address for S. Ikegami: ikegamish@shinshu-u.ac.jp. E-mail address for H. Kato: hirokato@shinshu-u.ac.jp. E-mail address for N. Saito: saitoko@shinshu-u.ac.jp.
Shota
S
Ikegami
Department of Orthopedic Surgery (K.T., Y.A., H.S., S.T., S.I., and H.K.) and Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research (N.S.), Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan. E-mail address for K. Tensho: kten@shinshu-u.ac.jp. E-mail address for Y. Akaoka: zebrawoodc@shinshu-u.ac.jp. E-mail address for H. Shimodaira: shimohei4792@yahoo.co.jp. E-mail address for S. Takanashi: seijit@shinshu-u.ac.jp. E-mail address for S. Ikegami: ikegamish@shinshu-u.ac.jp. E-mail address for H. Kato: hirokato@shinshu-u.ac.jp. E-mail address for N. Saito: saitoko@shinshu-u.ac.jp.
Hiroyuki
H
Kato
Department of Orthopedic Surgery (K.T., Y.A., H.S., S.T., S.I., and H.K.) and Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research (N.S.), Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan. E-mail address for K. Tensho: kten@shinshu-u.ac.jp. E-mail address for Y. Akaoka: zebrawoodc@shinshu-u.ac.jp. E-mail address for H. Shimodaira: shimohei4792@yahoo.co.jp. E-mail address for S. Takanashi: seijit@shinshu-u.ac.jp. E-mail address for S. Ikegami: ikegamish@shinshu-u.ac.jp. E-mail address for H. Kato: hirokato@shinshu-u.ac.jp. E-mail address for N. Saito: saitoko@shinshu-u.ac.jp.
Naoto
N
Saito
D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D031222:Patellar Dislocation / Q000000981:diagnostic imaging / Q000473:pathology*; D012189:Retrospective Studies; D013977:Tibia / Q000000981:diagnostic imaging / Q000473:pathology*; D014057:Tomography, X-Ray Computed; D014102:Torsion Abnormality / Q000000981:diagnostic imaging / Q000473:pathology; D055815:Young Adult