Summary

This study showed no differences in clinical outcomes, satisfaction, return to sport, or reoperations in patients that received pre-operative knee injections compared to those that did not, irrespective of the type of injection received, prior to OCA transplantation in the knee.

Abstract

Purpose

Intra-articular injections are a common non-operative treatment for pain in knee osteoarthritis. Similarly, injections may alleviate pain caused by osteochondral lesions, which exhibit similar progressions of articular cartilage degeneration. There is currently conflicting literature with respect to the effect of injections on clinical outcomes in patients with osteochondral lesions. The purpose of this study is to evaluate the effect of pre-operative knee injections on clinical outcomes and return to sport following osteochondral allograft (OCA) transplantation of the knee.

Methods

This is a retrospective study of patients who underwent OCA transplantation at a single institution with at least 1 year clinical follow-up. Patients who received knee injections including platelet-rich plasma (PRP), corticosteroid (CS), and hyaluronic acid (HA) injections were identified. Clinical outcomes were assessed using a visual analog scale (VAS) for pain and satisfaction, the Knee Injury and Osteoarthritis Outcome Score (KOOS), and a detailed sport activity and return-to-sport survey. Revisions and post-operative complications including graft failure was also recorded. Patients were divided into two cohorts (those who received injections and those who did not) and outcomes were compared using T-tests and Chi-square analyses. ANCOVA and logistic regression models were used to control for confounders. Subsequent sub-analyses were performed to identify differences between patients who received CS and HA injections specifically.

Results

A total of 96 patients were included in this analysis, 67 (69.7%) received no injection during their pre-operative course and 29 (30.2%) who received an injection prior to their OCA transplantation (15 patients received HA/15 received CS injections). Patients in the injection group were older than those in the no-injection group (40.8 ±10.1 years vs. 32.4±11.3 years, p<0.001). However, no difference in the number of high-grade lesions, BMI, or gender was observed between the two cohorts. Clinical outcomes were similar between cohorts with patient satisfaction score of 77.6 ± 27.2 in the no injection cohort compared to 69.3 ±33.3 in the injection cohort (p=0.203). KOOS subscores were similar between the two cohorts after controlling for the age difference. Sub-analysis based on the type of injection received demonstrated no difference in outcomes between the two cohorts. 59.1% of patients in the no injection group returned to sport compared to 70.4% in the injection group, p=0.308. 25.0% of patients underwent reoperation (10 patients undergoing adhesiolysis/manipulation under anesthesia) with no difference in need for reoperation between the cohorts. Graft failure was noted in 3 patients. Lastly, when subanalysis was performed based on type of injection (HA/CS) received, satisfaction scores for the patients who received HA injections were statistically higher when controlling for age (79.6 ± 57.4, p=0.037).

Conclusion

There were no differences in clinical outcomes, satisfaction, return to sport, or reoperations in patients that received pre-operative knee injections compared to those that did not, irrespective of the type of injection received, prior to OCA transplantation in the knee. The frequency of reoperations were similar between both study groups.