Introduction of a Clinical Practice Guideline for Patella Reduction by Paramedics: The Effect on Pain Relief,...

Patella dislocation is a common and painful form of orthopedic injury cared for by paramedics. Care is typically limited to analgesia and transport to an emergency department, delaying definitive joint relocation. In November 2022, Ambulance Victoria introduced a guideline recommending out-of-hospital patella reduction by paramedics. This study aimed to evaluate the effect of the guideline on pain reduction and other clinically and service-oriented outcomes.

A retrospective study was conducted using emergency medical service electronic patient care data from the state of Victoria, Australia. Consecutive patients presenting with acute patella dislocation between September 1, 2021 and August 31, 2023 were included. Interrupted time series analysis was used to evaluate the effect of the guideline on the proportion of patients with effective analgesia, defined as ≥50% reduction from the initial pain score.

The analysis included 1,210 patients with 622 in the pre-implementation group and 588 in the post-implementation group. Following the introduction, there was no significant step change in the proportion of patients reporting substantial analgesia (0.8%, 95%CI -6.6%, 8.1%; p = 0.832). There was a significant reduction in the rate of intravenous (IV) access (-17.3%, 95%CI -25.9%, -8.7 %; p < 0.001), transport to hospital (-38.4%, 95%CI -48.2%, -28.7%; p < 0.001) and case duration (-32.9 min, 95%CI -50.8, -15.0; p < 0.001). The success rate of reduction attempts was 91.8%. The median estimated duration of dislocation was 71 min shorter amongst patients who received a successful reduction (median minutes: 47 [IQR 32-65] versus 118 [96-157]; p < 0.001).

The introduction of a guideline for patella reduction by paramedics was associated with similar rates of effective analgesia and significant reductions in intravenous access, transport rate, and total case duration. Future studies should examine the longer-term functional outcomes, patient experience, and safety associated with patella reduction by paramedics.