Vertical Drop Jump Biomechanics of Patients With a 3- to 10-Year History of Youth Sport-Related Anterior Cruciate Ligament Reconstruction

Patients With a Quadriceps Tendon Autograft Demonstrate Greater Asymmetry in Landing Kinetics Than Patients With a Bone-Patellar Tendon-Bone Autograft 6 Months After Anterior Cruciate Ligament Reconstruction

BACKGROUND

Asymmetric landing kinetics 6 months after anterior cruciate ligament reconstruction (ACLR) are associated with higher risk of second anterior cruciate ligament injury. Little is known about landing kinetics after ACLR with an all-soft tissue quadriceps tendon (QT) autograft despite its increasingly common use in young, active patients.

PURPOSE/HYPOTHESIS

The purpose of this study was to compare landing kinetics during a bilateral drop vertical jump (DVJ) 6 months after ACLR in participants who had undergone primary ACLR with a QT or bone-patellar tendon-bone (BTB) autograft. The hypothesis was that patients with a QT autograft will experience more asymmetry during a bilateral DVJ than patients with a BTB autograft 6 months after ACLR. In addition, greater impact force asymmetry will be associated with worse patient-reported outcome measures.

STUDY DESIGN

Controlled laboratory study.

METHODS

Participants who underwent primary unilateral ACLR with a QT or BTB autograft between May 2022 and December 2023 were prospectively recruited to undergo DVJ assessment and patient-reported outcome measures 6 months after ACLR. DVJ assessment was completed using force-sensing insoles. Peak impact force, average loading rate, and impulse data were collected at 100 Hz.

RESULTS

Forty-four participants (22 BTB, 22 QT) completed DVJ assessment and International Knee Documentation Committee (IKDC) and Anterior Cruciate Ligament-Return to Sport After Injury (ACL-RSI) surveys at 6 ± 1 months after ACLR. Graft source groups did not differ by age (P = .884), sex (P = .531), mass (P = .872), height (P = .572), months since surgery (P = .683), or lateral (P = .637) or medial (P = .416) meniscal tear treatment rate. On average, participants with a QT autograft demonstrated 26.2% greater contralateral limb peak impact force (P = .004), 18.4% lower peak impact force limb symmetry index (P = .009), 18.5% lower involved limb impulse (P < .001), and 15.1% lower impulse limb symmetry index (P < .001) when compared with participants with a BTB autograft. Graft source groups did not differ in IKDC score (P = .333) or ACL-RSI score (P = .070). Neither IKDC nor ACL-RSI score was strongly associated with any kinetic variables.

CONCLUSION/CLINICAL RELEVANCE

Participants with a QT autograft exhibit greater asymmetry in landing kinetics when compared with participants with a BTB autograft 6 months after ACLR, and landing kinetics were not associated with IKDC or ACL-RSI score.

Drop landing analysis of rotational osteotomies

Pathomechanics resulting from rotational deformities of the long bones in an idiopathic population have not been extensively studied, and are chiefly limited to level over ground walking. Thirty-five adolescents with excessive idiopathic outward tibial torsion (TT), femoral rotation, or both (pan genu) were studied both before and after corrective surgery. Data collected included computational motion analysis of a drop jump and patient-reported outcomes consisting of PODCI and Goal Attainment Scores. Results were compared to an age-matched typically developing cohort (n = 25). Subjects with femoral anteversion (FA) exhibited compensatory hip rotations to normalize knee progression angles at landing. Subjects with only TT did not compensate at the hip, landing with typical knee progression but excessive outward foot progression. These strategies resulted in elevated frontal plane knee moments for FA ( P  = 0.008), and elevated lateral knee forces in all groups compared to typical, with the TT group reaching significance ( P  < 0.001). Rotational osteotomies successfully restored elevated kinematics and kinetics to within or below typically developing ranges. Patient-reported outcomes generally improved after surgery across all domains studied. Drop jump testing elucidated compensation strategies employed by these cohorts. Compensation did not fully alleviate elevated forces at the knees. Surgical intervention normalized pathokinematics and pathokinetics, reduced pain, and improved patients' perception of their functional abilities. Greater improvements were found in individuals in the two groups with FA compared to the group with TT only.

Lower extremity joint angle, moment, and coordination throughout a double limb drop vertical jump in individuals with anterior cruciate ligament reconstruction

Individuals with anterior cruciate ligament reconstruction (ACLR) utilise different landing biomechanics between limbs, but previous analyses have not considered the continuous or simultaneous joint motion that occurs during landing and propulsion. The purpose of this study was to compare sagittal plane ankle/knee and knee/hip coordination patterns as well as ankle, knee, and hip angles and moments and vertical ground reaction force (vGRF) between the ACLR and uninjured limbs during landing and propulsion. Fifteen females and thirteen males performed a drop vertical jump from a 30 cm box placed half their height from force platforms. Coordination was compared using a modified vector coding technique and binning analysis. Kinematics and kinetics were time normalised for waveform analyses. Coordination was not different between limbs. The ACLR limb had smaller dorsiflexion angles from 11 to 16% of landing and 24 to 75% of landing and propulsion, knee flexion moments from 5 to 15% of landing, 20 to 31% of landing, and 35 to 91% of landing and propulsion, and vGRF from 92 to 94% of propulsion compared with the uninjured limb. The ACLR limb exhibited smaller dorsiflexion angles to potentially reduce the knee joint moment arm and mitigate the eccentric and concentric demands on the ACLR knee during landing and propulsion, respectively.

Jumping into recovery: A systematic review and meta-analysis of discriminatory and responsive force plate parameters in individuals following anterior cruciate ligament reconstruction during countermovement and drop jumps

Purpose

Comprehensive understanding of force plate parameters distinguishing individuals postprimary anterior cruciate ligament reconstruction (ACLR) from healthy controls during countermovement jumps (CMJ) and/or drop jumps (DJ) is lacking. This review addresses this gap by identifying discriminative force plate parameters and examining changes over time in individuals post-ACLR during CMJ and/or DJ.

Methods

We conducted a systematic review and meta analyses following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. Nine databases were searched from inception to March 2022. We included cross-sectional papers comparing post-ACLR with healthy controls or longitudinal studies of individuals at least 6 months postprimary ACLR while performing CMJ and/or DJ on force plates. The methodological quality was appraised using the Modified Downs and Black Checklist.

Results

Thirty-three studies including 1185 (50.38%) participants post-ACLR, and 1167 (49.62%) healthy controls, were included. Data were categorised into single-leg CMJ, double-leg CMJ, single-leg DJ, and double-leg DJ. Jump height was reduced in both single (mean difference [MD] = -3.13; p < 0.01; 95% confidence interval [CI]: [-4.12, -2.15]) and double-leg (MD = -4.24; p < 0.01; 95% CI: [-5.14, -3.34]) CMJs amongst individuals with ACLR. Similarly, concentric impulse and eccentric/concentric impulse asymmetry could distinguish between ACLR (MD = 3.42; p < 0.01; 95% CI: [2.19, 4.64]) and non-ACLR (MD = 5.82; p < 0.01; 95% CI: [4.80, 6.80]) individuals. In double-leg DJs, peak vertical ground reaction forces were lower in the involved side (MD = -0.10; p = 0.03; 95% CI: [-0.18, -0.01]) but higher in the uninvolved side (MD = 0.15; p < 0.01; 95% CI: [0.10, 0.20]) when compared to controls and demonstrated significant changes between 6 months and 3 years post-ACLR.

Conclusion

This study identified discriminative kinetic parameters when comparing individuals with and without ACLR and also monitored neuromuscular function post-ACLR. Due to heterogeneity, a combination of parameters may be required to better identify functional deficits post-ACLR.

Level of Evidence

Level III.