rip_patella_score: Recurrent Instability of the Patella (RIP) Score

In cliot: Clinical Indices and Outcomes Tools

Recurrent Instability of the Patella (RIP) Score

Description

Calculates the RIP Score to predict the risk of recurrent patellar dislocation. The score utilizes four clinical and radiographic factors: age, skeletal maturity (open physes), trochlear dysplasia, and history of contralateral dislocation.

Usage

rip_patella_score(age, skeletal_immature, trochlear_dysplasia,
                  contralateral_dislocation)

Arguments

age	Numeric. Patient age in years. (< 25 years adds 2 points).
skeletal_immature	Numeric (0 or 1). Are physes open (skeletally immature)? (1 = Yes, +1 point).
trochlear_dysplasia	Numeric (0 or 1). Presence of trochlear dysplasia on lateral radiograph. (1 = Yes, +1 point).
contralateral_dislocation	Numeric (0 or 1). History of contralateral patellar dislocation. (1 = Yes, +1 point).

Value

A list containing:

RIP_Score	The calculated total score (Range 0-5).
Risk_Category	Classification (Low 0-1, Intermediate 2-3, High 4-5).
Recurrence_Risk	Estimated percentage risk of recurrence.

References

Cheung JP, Fung B, Ip WY, Chow SP. Review on recurrent dislocation of the patella. Orthopedics. 2008;31(1):76-80. Hevesi M, Heckmann N, Brown GA, et al. The Recurrent Instability of the Patella (RIP) Score: A Statistically Based Predictive Tool for Recurrent Patellar Instability. Am J Sports Med. 2019;47(4):922-928. doi:10.1177/0363546518825255

Examples

# Example 1: High Risk
# 16yo (+2), Open Physes (+1), Dysplasia (+1), No contralateral history
# Score = 4
rip_patella_score(16, 1, 1, 0)

# Example 2: Low Risk
# 30yo (0), Closed Physes (0), Dysplasia (1), No contralateral history
# Score = 1
rip_patella_score(30, 0, 1, 0)

cliot documentation built on Dec. 1, 2025, 1:06 a.m.