The purpose of this study is to determine the feasibility and initial efficacy of static progressive splinting for individuals presenting with knee stiffness following total knee arthroplasty (TKA). Data from this trial will be utilized in a NIH grant application for a larger randomized controlled trial directly comparing static progressive splinting to manipulation under anesthesia (MUA) which is the current standard of care for knee stiffness after TKA.

Total knee arthroplasty (TKA) is the standard of care to manage the pain and disability associated with end-stage knee osteoarthritis, with more than 700,000 TKA surgeries performed annually in the United States. Knee stiffness, commonly caused by arthrofibrosis, is an infrequent, but debilitating complication of TKA, with an incidence upwards of 5% postoperatively. As a predominant failure mechanism, knee stiffness accounts for 28% of hospital readmissions due to surgical complications within 90 days of discharge, and 10% of all revisions within 5 years of initial surgery within the United States. With the incidence of TKA projected to reach 3.5 million by 2030, the growing cohort of TKA patients with postoperative knee stiffness provides an important target for research.

Several treatments for knee stiffness have been described including static progressive splinting and manipulation under anesthesia (MUA). To date, no studies have compared the use of static progressive splinting in the early management of individuals presenting with knee stiffness after TKA to more commonly utilized surgical procedures such as MUA. Witvrouw and colleagues compared a computer-controlled passive motion device to MUA for individuals with knee stiffness after TKA and found that stretching device had similar outcomes to MUA in terms of range of motion (ROM) and self-reported pain, stiffness and function. A key limitation of this study is that the computer-controlled motion device is not commercially available and therefore translation of this technology into practice is unlikely. However, this study does demonstrate that conservative stretching techniques may be as efficacious as costlier surgical techniques as well as may cause fewer adverse events such as quadriceps tendon rupture and fractures. Only one study to date has examined the utilization of static progressive splinting after TKA. In this study, they enrolled patients who had already failed MUA and conservative physical therapy management strategies. They found that the average ROM increase for patients was 25° as well as 92% of patients were satisfied with the results and no complications occurred with use of the device. Key limitations to this study are the lack of a comparison group as well as static progressive splinting was utilized after MUA had already failed. It is unknown how individuals would respond to this treatment compared to MUA.

Therefore, the purpose of our study is to determine the feasibility and initial efficacy of static progressive splinting for individuals presenting with knee stiffness following TKA within the current surgical practice of Dr. Jared Foran at Panorama Orthopedics & Spine Center. Data from this trial will be utilized in a NIH grant application for a larger randomized controlled trial directly comparing static progressive splinting to MUA which is the current standard of care for knee stiffness after TKA.

Inclusion Criteria:

• Undergone a unilateral primary Total Knee Arthroplasty (TKA) for end-stage osteoarthritis
• Knee stiffness in the first 6 weeks post-operative defined as knee flexion < 100 degrees

Exclusion Criteria:

• Preoperative knee range of motion less than 15-110 degrees
• Intraoperative (closed) range of motion < 0-120 degrees
• Radiographic signs of heterotopic ossification
• Misaligned components or component-related failures of knee prosthesis that could be responsible for difficulties with motion
• Signs and symptoms consistent with joint infection
• Signs and symptoms consistent with complex regional pain syndrome