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Combined Correction of Tibial Torsion and Tibial Tuberosity-Trochlear Groove Distance by Supratuberositary Torsional Osteotomy of the Tibia

Lukas Jud, Sarvpreet Singh, Timo Tondelli, Philipp Fürnstahl, Sandro F Fucentese & Lazaros Vlachopoulos

abstract

BACKGROUND
Increased external tibial torsion and tibial tuberosity-trochlear groove distance (TTTG) affect patellofemoral instability and can be corrected by tibial rotational osteotomy and tibial tuberosity transfer. Thus far, less attention has been paid to the combined correction of tibial torsion and TTTG by supratuberositary osteotomy.

PURPOSE
To quantify the effect of a supratuberositary torsional osteotomy on TTTG.

STUDY DESIGN
Descriptive laboratory study.

METHODS
Seven patients who underwent supratuberositary osteotomy to treat patellofemoral instability and an additional 13 patients with increased TTTG were included (N = 20). With 3-dimensional (3D) surface models, supratuberositary rotational osteotomies were simulated with predefined degrees of rotation. Concomitant 3D TTTG was measured by a novel and validated measurement method. In addition, all operated patients underwent 2-dimensional (2D) radiographic evaluation with pre- and postoperative computed tomography data. Absolute differences among simulated, predicted, and achieved postoperative corrections were compared.

RESULTS
A total of 500 supratuberositary osteotomies were simulated. The linear regression estimate yielded a change of -0.68 mm (95% CI, -0.72 to -0.63; < .0001) in 3D TTTG per degree of tibial rotation, and 2D and 3D TTTG measurements in the operated patients were comparable in pre- and postoperative measurements (preoperative, 19.8 ± 2.5 mm and 20.0 ± 2.4 mm; postoperative, 13.6 ± 3.8 mm and 14.6 ± 3.4 mm, respectively). Postoperative 2D TTTG deviated in absolute terms from predicted (regression) and simulated TTTG by 1.4 ± 1.0 mm and 1.5 ± 0.6 mm. Inter- and intrarater reliability (intraclass correlation coefficient) for radiological and simulated measurements ranged between 0.883 and 0.996 and were almost perfect.

CONCLUSION
In supratuberositary osteotomy, TTTG changes by -0.68 mm per degree of internal tibial rotation. The absolute mean difference between postoperative predicted TTTG and 2D TTTG was only 1.4 mm. Thus, TTTG correction can be successfully predicted by the degree of tibial rotation.

CLINICAL RELEVANCE
TTTG correction can be successfully predicted by the degree of tibial rotation. Therefore, in selected cases, tibial torsional deformity and TTTG can be corrected by 1 osteotomy. However, isolated rotations have been performed, and unintended translational movements during tibial rotation may alter the postoperative results.
   
citation Jud L, Singh S, Tondelli T, Fürnstahl P, Fucentese S F, Vlachopoulos L. Combined Correction of Tibial Torsion and Tibial Tuberosity-Trochlear Groove Distance by Supratuberositary Torsional Osteotomy of the Tibia. Am J Sports Med 2020; 48:2260-2267.
   
type journal paper/review (English)
date of publishing 18-06-2020
journal title Am J Sports Med (48/9)
ISSN electronic 1552-3365
pages 2260-2267
PubMed 32551826
DOI 10.1177/0363546520929687