Abstract
Introduction
Unicompartmental Knee Arthroplasty (UKA) has been offered as a tissue sparing alternative to total knee arthroplasty (TKA) for treatment of early to mid-stage osteoarthritis (OA). While the spared tissue and retention of cruciate ligaments may result in faster recovery, smaller incision, less bone resection, decreased pain and blood loss and more normal kinematics and function, UKA has shown unpredictable results in practice, which may be due to variations in surgical techniques1. Recently a robotic-assisted technique has been introduced as a means to provide more consistent and reproducible surgical results. In this study, the early return to function was measured to determine proposed benefits between UKA and TKA.
Methods
Patients requiring either UKA or TKA were prospectively enrolled in this IRB approved study. Each patient received pre-operative education regarding their expected physical therapy (PT) regimen, which was uniform for all patients. PT was determined to be concluded when each patient reached an achievable functional endpoint with each of the following 5 criteria: range of motion from 5 to 115 degrees, recovery of flexion and extension strength to 4/5 of pre-operative strength, gait with minimal limp and without an assistive device for 250 feet and ability to ascend and descend a flight of stairs with step over gait and good control. The number of PT visits to reach each functional goal was recorded.
Results
18 patients (19 knees) were enrolled in the study, with 8 females and 10 males. 13 knees received a TKA and 6 received a UKA. Average age was 65.6 ± 6.4 (range: 54–79) and average body mass index (BMI) was 27.62± 4.9 (range: 20.1–36.6). Age and BMI did not differ between the two groups. Average number of PT visits to reach each functional endpoint is listed in table 1 below. While the UKA group required less visits to reach each criteria, a significant difference (P<0.05) was seen in gait with minimal limp, flexion to 115 degrees, and extension of 5 degrees.
Table 1. Number of Physical Therapy visits required to reach Functional Endpoint for TKA and UKA patients
Discussion
Early results show less physical therapy is required for UKA patients than TKA patients to reach the same functional goals. As physical therapy accounts for a significant portion of the episode of care for knee arthroplasty, this quicker recovery may result in a decreased economic burden. More patients and longer follow-up are required to determine full clinical and economic benefit of UKA procedure.
