AJSM - 2026-09-02 - Journal Article
Quadriceps Tendon Autograft Harvest Technique Affects Both Graft Strength and Cross-sectional Area.
Bi AS, Augustin EJ, Smelley CC, Angotti ML, Acheampong KK, Sachdev D, Shewman E, Yanke AB
Topics
Key Takeaway
Full-thickness double-blade quadriceps tendon grafts (DB-QT) achieved a mean CSA of 0.97 cm² and the highest load-to-failure, significantly exceeding both cylindrical-harvester QT grafts (0.64 cm²) and BTB grafts (0.44 cm²).
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Summary
This cadaveric study compared CSA and biomechanical properties of BTB, double-blade full-thickness QT (DB-QT), and cylindrical-harvester QT (CH-QT) grafts, all harvested at 9 mm width. DB-QT produced the largest CSA (0.97 ± 0.22 cm²) and highest load-to-failure, followed by CH-QT (0.64 ± 0.10 cm²) and BTB (0.44 ± 0.08 cm²), with all pairwise differences significant (P < .01). After normalization to CSA, stress and strain were equivalent across graft types, indicating that harvest technique drives structural differences through graft volume rather than intrinsic tissue properties.
Key Limitation
The cadaveric model eliminates in vivo variables including graft healing, tunnel incorporation, and the clinical impact of DB-QT's greater CSA variability, which could translate to unpredictable graft sizing in live patients.
Original Abstract
BACKGROUND
Bone-patellar tendon-bone (BTB) autografts have been considered the gold standard for anterior cruciate ligament reconstruction, although the popularity of quadriceps tendon (QT) autografts is increasing.
HYPOTHESIS/PURPOSE
The purpose of this study was to compare the ultrasound-derived cross-sectional area (CSA) and biomechanical strength of BTB and QT grafts harvested with different techniques. The authors hypothesized that ultrasound CSA measurements would be reliable and that QT grafts would be larger and stronger than BTB grafts, without differences between QT harvest methods.
STUDY DESIGN
Controlled laboratory study.
METHODS
Thirty grafts from 15 cadaveric knees included 15 BTB grafts harvested with a 9-mm double-blade scalpel, 7 full-thickness QT grafts harvested with the same 9-mm double-blade scalpel (DB-QT), and 8 QT grafts harvested with a proprietary 9-mm cylindrical QT harvester (CH-QT). CSA was measured at 3 regions with ultrasound by 2 raters, followed by cyclic loading and pull-to-failure testing. Between-group differences were analyzed, and associations between CSA and biomechanical outcomes were assessed with linear regression.
RESULTS
Ultrasound CSA demonstrated good to excellent reliability (ICC 2,1 = 0.70-0.87; ICC 2, k = 0.82-0.93). CSA differed between graft types (mean ± SD; BTB, 0.44 ± 0.08 cm 2 ; CH-QT, 0.64 ± 0.10; DB-QT, 0.97 ± 0.22; all pairwise P < .01), with heterogeneous variance (Levene P = .002). DB-QT demonstrated greater CSA variability than BTB ( P = .005) and no difference in variability when compared with CH-QT ( P = .055). Maximum load and energy to maximum load differed significantly (both omnibus P < .001) with DB-QT > CH-QT > BTB, with significant post hoc differences. In paired-knee analyses, pooled QT grafts also demonstrated greater maximum displacement than BTB grafts from the same specimens. CH-QT demonstrated significantly greater variability in maximum load than BTB ( P = .002) and DB-QT ( P = .045). Mean displacement at maximum load and stiffness were similar, although variance differed. Cyclic elongation differed among grafts (omnibus P = .011), with DB-QT < CH-QT < BTB, while other cyclic measures did not differ. When grafts were pooled, CSA correlated positively with maximum load and energy to maximum load; however, within-graft type regressions were not significant. After normalization to CSA, stress and strain were similar across graft types.
CONCLUSION
QT grafts were significantly larger and stronger than BTB, with full-thickness double-blade harvest producing the greatest CSA and load to failure. Ultrasound was a reliable tool to measure CSA, which correlated with graft strength.
CLINICAL RELEVANCE
QT grafts demonstrate greater structural capacity than BTB, and QT harvest technique influences graft size and strength, with double-blade harvest producing larger, stronger grafts.