Comparison Of Physical Therapy Utilization And Motion-related Reoperations Between Isolated ACL And Multiligament Knee Injuries

PURPOSE: The increased prevalence of postoperative arthrofibrosis after multiligament knee injuries (MLKI) compared to isolated anterior cruciate ligament (ACL) injuries has been proposed to be due, in part, to patient factors limiting physical therapy utilization. The purpose of this study was to compare demographic factors, pre- and postoperative physical therapy utilization, and the need for motion-restoring surgery between MLKI and ACL-injured patients. METHODS: Using the PearlDiver Mariner database, two cohorts were identified using Current Procedural Terminology (CPT) codes and included those between the ages of 16 and 60 that underwent isolated ACL (n = 96,535) vs. MLKI reconstruction (n = 3,537). The number of pre- and postoperative physical therapy visits were recorded as was the need for motion-restoring surgery (manipulation under anesthesia or arthroscopic lysis of adhesions). Demographic factors, physical therapy utilization, and the prevalence of motion-restoring surgery were compared between ACL and MLKIs using chi-square or t-tests as appropriate. RESULTS: The MLKI group included a greater proportion of male patients and fewer patients had commercial insurance. A significantly greater proportion of MLKI patients underwent subsequent motion-restoring surgery (MLKI = 202/3,537(5.7%) vs. ACL = 1878/96,537(1.9%), p = 0.0001; Odds Ratio = 3.1 [95%CI: 2.6, 3.5], p < 0.0001); however, neither pre- nor postoperative physical therapy utilization differed between groups. CONCLUSIONS: The prevalence of motion-restoring surgery was significantly greater after MLKI when compared to isolated ACL injury. However, despite observed differences in age, sex, and insurance provider, physical therapy utilization was not decreased for patients with MLKIs. While the risk of arthrofibrosis after MLKI is likely multifactorial, the current results suggest that patient factors alone are not solely responsible for the increased risk of arthrofibrosis after MLKI. The underlying mechanisms may then be biological and/or physiological in nature. Future work is necessary to elucidate whether the increased risk of arthrofibrosis after MLKIs is related to a greater inflammatory response due to the increased severity of injury, more involved surgical procedures, and/or prolonged immobilization.