| Abstract ID |
| 20260033 |
| Category |
| Knee: ACL |
| Preferable Presentation |
| Both |
| Title |
| ORAL ALENDRONATE REDUCES TUNNEL DIAMETER FOLLOWING ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION: PRELIMINARY RESULTS OF A MULTI-CENTRE, DOUBLE-BLIND, RANDOMIZED PLACEBO-CONTROLLED TRIAL |
| Author |
|
| Presenter |
| Christine Hoi Yan FU |
| Abstract |
BACKGROUND: Bone tunnel widening and peri-tunnel bone resorption are common, which impair tendon graft fixation to bone tunnel in anterior cruciate ligament reconstruction (ACLR). Alendronate is a bisphosphonate that may reduce peri-tunnel bone loss, promote tunnel bone acquisition, and hence clinical and functional outcomes. OBJECTIVES: This study aimed to evaluate the effects of oral alendronate on tunnel bone acquisition, peri-tunnel bone loss, and knee function in primary ACLR patients. STUDY DESIGN & METHODS: This is a multi-center, double-blinded, placebo-controlled randomized trial with subject recruitment from four local public hospitals and one private hospital. The surgical procedures, postoperative follow-up, and rehabilitation were standardized across sites. The trial complied with all the regulatory guidelines. Patients aged 14 and older, without a prior history of knee injuries or surgeries, who are undergoing primary ACL reconstruction with a hamstring autograft and have no concomitant ligament injuries were recruited for the study. Additionally, participants must not be receiving long-term medications that affect bone metabolism and should not have contraindications to alendronate therapy. After signing the consent form, participants were randomly assigned to the oral alendronate (ALN group; 70 mg weekly from postoperative day 8 for 16 weeks) or l placebo treatment (PCB group) at a 1:1 ratio with a block size of 6 at each study site. Participants and outcome assessors were blinded to the study. Group allocation remained concealed from the data analyst until the intervention was completed. The primary outcomes included bone tunnel diameter, bone tunnel cross-sectional area (CSA), bone mineral density (BMD), and bone volume/total volume (BV/TV) at the distal femur and proximal tibia, as measured by HR-pQCT, along with knee laxity assessed by KT-1000. Secondary outcomes encompassed Lysholm Score, IKDC, IPAQ, and functional knee stability. Here we reported the results of 24 participants following the completion of the 16-week intervention. RESULTS: Both groups demonstrated 100% drug compliance with no adverse reactions. The percentage increase in tunnel diameter from baseline at both bone tunnels was significantly smaller in the ALN group compared to the PCB group (distal femur: ?=0.038; proximal tibia: p=0.027). The percentage increase in tunnel CSA at the proximal tibia was also lower in the ALN group compared to the PCB group, although this difference was marginally insignificant (p=0.059). Additionally, the percentage decrease in bone volume/total volume (BV/TV) from baseline at the proximal tibia was less in the ALN group compared to the PCB group, but this difference was not statistically significant (8% vs. 24%; p=0.149). Knee laxity, IKDC, Lysholm score, and IPAQ scores improved in both groups; however, no statistically significant differences were observed between groups (all p>0.05). DISCUSSION/CONCLUSION: The preliminary findings show that a 16-week course of oral alendronate is safe. The bone-protective effect of alendronae aligns with prior preclinical and pilot data. A larger trial with longer follow-up is warranted to confirm the effects of alendronate on bone resorption and clinical benefits. ACKNOWLEDGEMENT: This study is supported by the Health and Medical Research Fund [ref no. 22230171] and the InnoHK initiative of ITC [ref no. ITC RC/IHK/4/7]. |