how to improve the prediction of quadruple semitendinosus and...

How to improve the prediction of quadruple

semitendinosus and gracilis autograft sizes

with magnetic resonance imaging and

ultrasonography!

GELBER, Pablo E. MD, PhD !

Hospital de la Santa Creu i Sant Pau!ICATME-Institut Universitari Dexeus!

The author declares no conflict of interest!

Introduction!

May have unacceptable size for ACL-reconstruction3!

•!Hamstrings vs B-Patellar tendon-Bone!

•! Comparable functional results 1!

•! Hamstring less morbidity at the donor site 2!

Predict diameter of the 4STGT

with US and MRI!

Predict diameter of the 4STGT

with US and MRI

OBJETIVE!

Methods!•! 33 patients! 33 patients 33 patients 33 patients 33 patients

!! Scheduled for ACL-r with Hamstring autograft!!! MRI performed at our institution!!! Ultrasonography of the ST and GT tendons!

•!No previous ACL-r, Hamstring injury, partial ACL, multiligament knee injuries!

!! CSA of ST and GT!

!! 1.5T at widest point of medial femoral condyle!

!! Under 2x and 4x magnification!

!! Assessed with PACS workstation (Centricity Enterprise Web V3.0!

Ultrasonography! Ultrasonography!! Cross sectional area (CSA) of ST and GT!

!! Performed by the same person !

!! Same US device (LOGIQe, GE Healthcare, Milwaukee)!

!! Same linear array probe (7-12 MHz)!

Ultrasonography Ultrasonography Ultrasonography Ultrasonography Ultrasonography UltrasonographyMethods!

MRI!MRI

4x!

2x!

Results!

•!GT 6.2 ± 0,9 mm2!

•!ST 9.5 ± 1,7 mm2!

•!GT+ST 15,7 ± 2 mm2!

P<0.003

US-CSA graft Pearson CC 0.51!

CSA!

US-CSA graft Pearson CC 0.51US-CSA graft Pearson CC 0.51

CSA>14 mm2 " 8mm sensibility 81%! < 8mm specifity100%!

Results Ultrasonography! Ultrasonography Ultrasonography

4ST-GT diameter = 3.658 + 0.294 x US-CSA !

•!GT+ST 27.2 ± 4.4 mm2 2xMRI!2xMRI

P<0.001

Pearson CC 0.54!

CSA> 25 mm2 "8mm sensibility 75%! < 8mm specificity 85% !

CSA!

4ST-GT diameter = 5.81 + 0.667 x 2xMRI-CSA !

Results!

4x-MRI!4x-MRI

Pearson CC 0.86!

CSA! •!GT+ST 18.8 ± 2.8 mm2

CSA> 17 mm2 "8mm sensibility 96%! < 8mm specificity 100% !

4ST-GT diameter = 3.84 + 0.228 x 4xMRI-CSA !

•!No measurement of ST and GT separately!•!No measurement of the tendon lengths!•!Intra-inter obs. variability not calculated with US!

Limitations!

Discussion!

•!Graft <8mm: !! graft failure?!•! Antropometrics measurements and conventional !MRI have shown lower predictibility!

•!US and 2xMRI good and similar predictibility!•!4xMRI much greater accuracy!

•!25mm2, 17mm2 and 14mm2 are needed to reliably predict a 4ST+GT of at least 8mm in diameter!

Conclusions!

Bibliografía

1. Goldblatt JP, Fitzsimmons SE, Balk E, Richmond JC. Reconstruction of the anterior cruciate ligament: meta-analysis of patellar

tendon versus hamstring tendon autograft. Arthroscopy. 2005;21(7):791-803.!

2. Pinczewski LA, Lyman J, Salmon LJ, Russell VJ, Roe J, Linklater J. A 10-year comparison of anterior cruciate ligament

reconstructions with hamstring tendon and patellar tendon autograft. Am J Sports Med. 2007;35(4):564-574.

3. Pichler W, Tesch NP, Schwantzer G, et al. Differences in length and cross-section of semitendinosus and gracilis tendons and

their effect on anterior cruciate ligament reconstruction in athletes. J Bone JointSurg Br. 2008;90(4):516-519.

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