Hyaluronate Injections after Anterior Cruciate Ligament Reconstruction Does Not Improve Running Mechanics

Abstract

Mitigating inflammation early after anterior cruciate ligament reconstruction (ACLR) may help strength and biomechanical outcomes further in rehabilitation. PURPOSE: The purpose of this study was to determine if hyaluronate injections (HI) administered early after surgery improves strength and running mechanics six months after ACLR. METHODS: Nineteen individuals (Table 1) who suffered an ACL tear during sport participation were enrolled in a randomized double-blind controlled trial to test a post-operative intraarticular HI compared to a placebo one week after surgery (one patient screen failed, and one withdrew after surgery). Six months post-surgery individuals completed isokinetic quadriceps strength (IKQS) at 60°/second and a biomechanical analysis of overground running using 3D motion capture and force plates. Visual 3D was used to calculate bilateral lower extremity biomechanics including knee excursion (KEX) from initial contact to peak knee flexion, and peak vertical ground reaction forces (VGRF). Inverse dynamics were used to calculate internal peak knee abduction moments (KAM), and peak knee extension moments (KEM). A repeated measures analysis of variance was used to determine differences between groups (injection vs control) and limb (involved and uninvolved). An alpha value of 0.05 was used. RESULTS: There were no significant differences between the injection group and the control group in peak IKQS or running mechanics, and there was no significant group x limb interaction. In both the injection group and the control group, the involved limb exhibited significantly lower IKQS and KEM, less KEX, and lower peak VGRF (Table 1) compared to the uninvolved limb. CONCLUSION: The individuals who received the HI post-surgery did not present with improved strength or running mechanics six months post ACLR compared to control subjects. Future research should investigate further benefits of neuromuscular and physiological factors from a HI.