Summary

This study investigated whether an association exists between the presence, grade, and location of chondral lesions and postoperative pain after ACL reconstruction.

Abstract

Introduction

The presence of meniscal and chondral lesions at the time of ACL reconstruction is associated with worse patient reported outcomes. Few studies have examined the relationship between specific location and grades of chondral lesions and patient reported outcomes. The purpose of this study is to determine if there is an association between the presence, grade, and location of chondral lesions and postoperative pain after ACL reconstruction.

Methods

We examined the electronic health records of 137 patients who underwent ACL reconstruction by a single orthopedic surgeon from January 1, 2018 through March 1, 2021. Variables that were analyzed included age, body mass index (BMI), mechanism of injury, interval between injury and surgery, pre-operative clinical Lachman grade, pre-operative pivot test grade, and the type of graft utilized. Pre-operative MRIs and arthroscopic reports for each patient were analyzed for the presence and locations of meniscal injury, chondral injury, and bone marrow edema. The primary outcome of interest was pain at the most recent follow-up visit, excluding the initial 3 postoperative visits (3 days, 2 weeks, and 6 weeks post-surgery). Patients were excluded if they did not attend any post-operative visits beyond the initial 3 postoperative visits. Relationships between qualitative variables and the presence of pain were analyzed with Chi-square statistics. The crude odds ratio (OR) of the occurrence of pain after surgery was calculated using the univariate logistic regression method.

Results

We identified 137 patients who underwent ACL reconstruction from January 1, 2018 through March 1, 2021. The age range was 14 to 71 years, with 80 males and 57 females. In this patient group, 41 patients (29.9%) reported pain complications at their most recent follow-up. Patients were stratified based on age into younger than 19, 20-39 years, and older than 40 years, which revealed that the crude odds ratio of pain occurrence after surgery was 4.16 (p=0.008) in patients older than 40 compared to those younger than 19 years. There were also statistically significant crude odds ratios when analyzing BMI (p=0.027), mechanism of injury (p=0.006), interval between injury and surgery (p=0.042), and the choice of graft used in reconstruction (p=0.002). Although no significant relationship was identified when analyzing those with a Grade 3 or 4 chondral lesion and post-operative pain, there was a significant relationship between the presence of Grade 3 or 4 chondral lesions and age, with 42.4% of patients 40 years or older having a concomitant Grade 3 or 4 chondral lesion and an odds ratio of 14.73 (p<0.001) compared to those less than 19 years of age. No significant relationships were identified between the locations of the chondral lesions and postoperative pain.

Discussion

Pain is a significant complication post ACL reconstruction. Age greater than 40, BMI, mechanism of injury, choice of ACL graft, and interval between injury and time of surgery are predictors of post-operative pain. Additionally, an age greater than 40 years was associated with a statistically significant increase in the prevalence of Grade 3 & 4 chondral lesions. Thus, the presence of Grade 3 or 4 chondral lesions likely has an association with post-operative pain in patients with age greater than 40 years.