Abstract
Objectives:
The purpose of this study is to review recurrent injury and reoperations rates, physical examination findings, and patient reported outcomes in the first 100 Bridge registry subjects a minimum of 1 year postop from the Bridge Enhanced ACL Restoration (BEAR) procedure.
Methods:
Consecutive patients with ACL injuries indicated for BEAR at 6 institutions were invited to enroll in the Bridge registry either preoperatively or at the time of their first postoperative visit after study initiation. Subjects were prospectively followed at 3, 6, 9, and 12, and 24 months after surgery with physical examinations and surveys. Adverse events including recurrent or ipsilateral ACL injury, subsequent meniscus tears, and reoperations were recorded. Adverse events were compared between subjects whose BEAR procedure was performed using the original technique versus modified surgical techniques using Fisher’s Exact test. Range of motion, Lachman grade, firmness of endpoint, and pivot shift examinations were compared between baseline and 12 months using a paired T test for ROM and Wilcoxon Signed Rank Test for all stability measures. Patient reported outcomes (IKDC, KOOS, MARX, RSI) were compared between subjects over time.
Results:
Of the 100 subjects, 94 enrolled postoperatively and 6 enrolled preoperatively. Four exited the study, and 1 completed the 9 month, but not the 12 month follow up, providing 95% minimum 1 year follow-up (mean 15.3+4.7 mo, range 9-31 mo). The mean age was 31.3±14.3 years and 67% were female. 51 underwent a BEAR using the original technique, while 49 underwent a BEAR with a modified surgical technique. Modifications included use of an anchor on the femoral wall or tibia, use of luggage tag style suture rather than Bunnell suturing, or use of nonabsorbable instead of absorbable sutures in the ACL stump. The overall rates of adverse events and reoperations are as follows at 1 year: 1 DVT, 2 meniscal injuries without ACL retear, and 8 reoperations (1 lysis of adhesions/cyclops removal, 2 manipulations under anesthesia, 3 removals of retained ethibond suture, 1 partial lateral menisectomy, 1 medial meniscus repair).
Additional adverse events requiring reoperations between 1 and 2 years were 1 recurrent ACL tear with associated meniscus tears and 2 meniscal injuries without ACL tear. Overall reoperation rate was 8.4% at 1 year and 11.6% at 2 years, with 1% ACL retear rate in this cohort. There were no significant differences in adverse events or reoperation rates between the original technique and the modified technique groups. Mean IKDC, MARX and RSI scores at 12 months were (N=79) respectively 82.7 +14.6, 7.5 + 5.36, 66.6+24.06. Mean KOOS pain, function daily living, and function sports and recreational activities were as follows: 92.7+8.6, 96.7+6.0, and 82.0+18.5. Mean knee ROM (N=72) for flexion was 136+18.61 and active hyperextension (N=70) was 1.2+3.46 at 12 months. There was no significant loss of extension as compared to baseline and there was significant improvement in flexion. Lachman’s (N=73) was 0-2mm in 79.5% and grade 1 in 20.5% with 93.8% having a firm endpoint (N=64). Pivot shift (N=68) was negative in 89.7% and grade 1 in 8.8%, while 1.5% had a grade 2 pivot shift at 12 months.
Conclusions:
The rates of adverse events and acute failure status BEAR with and without modification are low at 1 year, with one retear occurring after 1 year with return to sport. Excellent stability and ROM are attained at 1 year. Further research in warranted to better understand long term outcomes of BEAR with and without modified techniques and with more widespread utilization of and indications.