Triamcinolone-Acetonide Extended-Release for the Management of Osteoathritis of the Knee

Introduction:
Injections are commonly administered for Osteoarthritis Knee (OAK) pain. Triamcinolone-Acetonide Extended-Release(TA-ER), FDA approved on 10/6/17, is effective and safe for initial and repeat use. Early onset and sustained duration are characteristic. This study follows a longitudinal cohort of patients injected with TA-ER.

Methods:
TA-ER was administered in a single practice to patients with symptomatic clinical and radiographic OAK, unresponsive to non-surgical modalities, and desiring to avoid or delay TKA. Repeat injections were offered after at least 3 months when pain recurred. Intervals between injections and before TKA were calculated.

Results:
285 patients received 784 injections into 377 knees(L385, R389) from 8/31/18—6/10/21. Age at initial injection was 73 years(R45—98); BMI was 28.8 kg/m2(R18.6—54). There were 177 (62%) females. Kellgren-Lawrence Radiographic Grade was 3-4. 141 patients had a single injection in one or both (58) knees; 92(32%) had bilateral injections. 144 patients(51%) received 405 repeat injections in 180 knees: 80 knees had 1 repeat injection, 46 had 2, 26 had 3, 11 had 4, 17 had > 5, and one had 10 bilaterally. Mean interval between injections was 21 weeks(R11-90.4). Only 59(21%) patients(63 knees) progressed to TKA. For 39 knees receiving a single injection, mean interval to surgery was 36.2 weeks(R12.9-137.3). For 24 knees with repeat injections, mean interval between initial injection and TKA was 72.2 weeks(R23.2-141.7). For all knees, mean interval between last injection and TKA was 34.5 weeks(R12.9-137.3). No injection or perioperative complications including infection occurred.

Discussion:
This real-world study documents initial experience with TA-ER for OAK. 51% of patients chose repeat injection(s); only 21% required TKA, which was delayed by 36 weeks with one injection, and 72 weeks with multiple. TA-ER is a valuable tool for treating painful OAK, and with repeated injections may provide prolonged pain relief prior to TKA.