1. Lateralization of the Tibial Tubercle in Recurrent Patellar Dislocation: Verification Using Multiple Methods to Evaluate the Tibial Tubercle
- Author
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Hiroyuki Kato, Shota Ikegami, Keiji Tensho, Daisuke Hatanaka, Suguru Koyama, Naoto Saito, Hiroki Shimodaira, and Yusuke Akaoka
- Subjects
Male ,Torsion Abnormality ,Tubercle ,Recurrent patellar dislocation ,Patellar Dislocation ,Multiple methods ,Lateralization of brain function ,Cruciate ligament ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,Recurrence ,medicine ,Cutoff ,Humans ,Orthopedics and Sports Medicine ,Retrospective Studies ,030222 orthopedics ,Receiver operating characteristic ,Tibia ,business.industry ,Area under the curve ,030229 sport sciences ,General Medicine ,musculoskeletal system ,medicine.anatomical_structure ,Case-Control Studies ,Surgery ,Female ,Nuclear medicine ,business ,Tomography, X-Ray Computed - Abstract
Background The tibial tubercle deviation associated with recurrent patellar dislocation (RPD) has not been studied sufficiently. New methods of evaluation were used to verify the extent of tubercle deviation in a group with patellar dislocation compared with that in a control group, the frequency of patients who demonstrated a cutoff value indicating that tubercle transfer was warranted on the basis of the control group distribution, and the validity of these methods of evaluation for diagnosing RPD. Methods Sixty-six patients with a history of patellar dislocation (single in 19 [SPD group] and recurrent in 47 [RPD group]) and 66 age and sex-matched controls were analyzed with the use of computed tomography (CT). The tibial tubercle-posterior cruciate ligament (TT-PCL) distance, TT-PCL ratio, and tibial tubercle lateralization (TTL) in the SPD and RPD groups were compared with those in the control group. Cutoff values to warrant 10 mm of transfer were based on either the minimum or -2SD (2 standard deviations below the mean) value in the control group, and the prevalences of patients in the RPD group with measurements above these cutoff values were calculated. The area under the curve (AUC) in receiver operating characteristic (ROC) curve analysis was used to assess the effectiveness of the measurements as predictors of RPD. Results The mean TT-PCL distance, TT-PCL ratio, and TTL were all significantly greater in the RPD group than in the control group. The numbers of patients in the RPD group who satisfied the cutoff criteria when they were based on the minimum TT-PCL distance, TT-PCL ratio, and TTL in the control group were 11 (23%), 7 (15%), and 6 (13%), respectively. When the cutoff values were based on the -2SD values in the control group, the numbers of patients were 8 (17%), 6 (13%), and 0, respectively. The AUC of the ROC curve for TT-PCL distance, TT-PCL ratio, and TTL was 0.66, 0.72, and 0.72, respectively. Conclusions The extent of TTL in the RPD group was not substantial, and the percentages of patients for whom 10 mm of medial transfer was indicated were small. Level of evidence Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.
- Published
- 2018