Summary

In our series, arthroscopic posterior capsular release resulted in significant improvement of knee extension and patient reported outcome scores at 6 month and 2 years postoperatively with a low rate of recurrent stiffness.

Abstract

Purpose

To describe outcomes of posterior capsular release to treat knee extension loss after anterior cruciate ligament (ACL) reconstruction in athletes.

Methods

A retrospective review was performed between January 2014 and December 2019 for patients undergoing arthroscopic posterior capsular release for knee extension loss after ACL reconstruction. Patients were indicated for the procedure if they had greater than 10 degrees of extension loss at least three months after ACL reconstruction that was refractory to physical therapy. Patients were included in the study if they were involved in either high school or college athletics, had complete outcomes of interest, and had at least 2 years of follow up. Collected outcomes included preoperative and postoperative measurement of knee extension, international knee documentation committee (IKDC) score, Lysholm score, return to sport data, and complications.

Results

Over the study period a total of 38 arthroscopic posterior capsular releases were performed. Of these, 20 were high school or college athletes. Two of these patients did not have 2-year follow up, leaving a total of 18 patients included in the analysis. Patients underwent surgery at an average of 16 weeks after ACL reconstruction. Knee extension improved an average of 13.8 degrees at 2-years follow up (pre-extension loss 15.1, post-extension loss 1.3, p < 0.005. At 2 years, there was no significant difference in knee extension when compared to the contralateral knee (p= 0.0151). Improvements in the IKDC score averaged 21.7 at 6 months and 35.0 at 24 months, both of which were statistically significant (p < 0.005). Similarly, differences in Lysholm included an improvement of 23.0 and 34.2 at 6 months and 2 years, respectively (p < 0.005). In total, 77.8% returned to sport at an average of 9.8 months from surgery. Complications included one patient that required revision capsular release for persistent extension loss, one ACL tear of the ipsilateral knee, and two ACL tears of the contralateral knee. No infections or neurovascular injuries occurred.

Conclusion

Knee extension loss after surgery can have significant consequences including reduced patient satisfaction and reduced return to sport. Although arthroscopic posterior capsular release is a recognized treatment for knee extension loss, outcomes have not been reported in athletes. In our series, arthroscopic posterior capsular release resulted in significant improvement of knee extension and patient reported outcome scores at 6 month and 2 years postoperatively. On average, patients had comparable range of motion to the contralateral knee postoperatively. Additionally, the procedure appears to be safe with few complications, including 5.6% need for repeat arthroscopy for knee extension loss. Posterior capsular release appears to be a reliable and safe treatment for athletes with persistent knee extension loss after ACL reconstruction.