Abstract
Objectives:
To compare the cost-effectiveness of nonoperative treatment, immediate operative treatment, and delayed operative treatment for first-time and recurrent episodes of patellar instability. Further, this study investigates the cost-effectiveness of medial patellofemoral ligament reconstruction (MPFL-R) versus medial patellofemoral ligament reconstruction with tibial tubercle osteotomy (MPFL-R with TTO).
Methods:
Using the Justifying Patellar Instability Treatment by Results (JUPITER) cohort, patients were prospectively enrolled between 2017-2022 if they were ages 10-35, had 1-year follow-up or more for treatment of patellar instability, did not have need for multi-ligamentous reconstruction, and completed all required follow-up assessments. Those who underwent previous ipsilateral knee surgery were excluded. Patients were categorized into first-time patellar or recurrent patellar dislocation, then subsequently categorized based on their treatment plan: nonoperative, initial operative, or delayed operative. Each group was further divided into three lifestyle alteration states: 1) severe/total alteration or lifestyle, 2) mild/moderate alteration of lifestyle, and 3) no alteration of lifestyle. The responses from the Knee Injury and Osteoarthritis Outcome Score (KOOS) Q2 question (“Have you modified your lifestyle to avoid potentially damaging activities to your knee?”) were used categorize patients in these states. Each lifestyle state was assigned a Quality Adjusted Life Year (QALY) score from 0-1, with 1 representing perfect health. This QALY score was an average of the patients’ Banff Patellofemoral Instability Instrument (BPII) (score for the annual assessment of patellofemoral treatment effectiveness) in each lifestyle state.
A Markov state transition model was constructed to assess the cost-effectiveness of each treatment modality for first time and recurrent patellar instability. The Markov model ran for 10 cycles, representing cost-effectiveness outcomes 10 years following initiation of treatment. Transition state probabilities between lifestyle states from initiation of treatment to 2 years were modeled using JUPITER derived probabilities. Transition state probabilities from years 2-10 were derived from existing literature. Cost of surgery, physical therapy, parental leave, and bracing were also derived from current literature and adjusted to inflation. A final ratio was used to compare cost-effectiveness between treatment modalities.
Results:
There were 307 First Time Dislocators and 380 Recurrent Dislocators that met inclusion criteria. A total of 257 patients underwent MPFL-R and 73 patients MPFLR with TTO. For first-time dislocators, a QALY score of .35 was associated with severe/total lifestyle alterations, .65 was associated with mild/moderate lifestyle alterations, and a score of .85 was associated with no. Comparative QALY scores for the recurrent dislocators group were 0.35, 0.64, and 0.87. QALY scores for the MPFLR surgical treatment group were greater compared to the MPFL-R with TTO group. Over a 2-year time-period, operative treatment had the highest QALY accruals out of all treatment modalities for both first time and recurrent dislocators, whereas delayed operative treatment had the lowest. Further analysis showed MPFLR without any concurrent bony procedures having a higher QALY accrual compared to MPFLR with TTO.
Conclusions:
Over a two-year period, operative treatment provided the highest utility amongst patients with first-time and recurrent patellar dislocations. Delayed operative treatment led to the lowest utility scores, emphasizing the importance of choosing the correct treatment modality from patients’ initial presentation and avoiding delay of definitive treatment. Lastly, isolated MPFL-R led to higher utility scores than MPFL-R with TTO, proving to be a more cost-effective form of operative treatment, giving providers another metric when ultimately deciding which operative measure to perform. Given that MPFL-R treatment provides the highest utility of all, there is further support for its utilization among both first-time and recurrent patellar dislocations as the standard treatment for patellar instability.
