The purpose of this study is to determine how well an active motion device, Camoped, works compared to a continuous passive motion device, CPM, for rehabilitation after partial or total knee replacement. It is hypothesized that the Camoped active motion device will provide outcomes equal to or superior than the CPM. Patients undergoing either partial or total knee replacement will be given the opportunity to participate. If they elect to participate, preoperative data will be collected including demographics, measures of strength, balance and knee bending, as well as surveys regarding current physical and mental health, as well as knee function. After surgery, patients will be randomly selected to receive either the Camoped or the CPM for use during their rehabilitation. After discharge, participants will be asked to maintain a daily diary tracking their use of the assigned device, as well as their daily pain levels. At a visit 4 weeks after surgery, participants will be asked to complete a series of surveys pertaining to their health and knee function, as well as to perform tests of strength, balance and knee bending. These results will be used to determine if one device produces superior rehabilitation results following total or partial knee replacement surgery.

The purpose of this study is to determine how well an active motion device, Camoped, works compared to a continuous passive motion device, CPM, for rehabilitation after partial or total knee replacement. It is hypothesized that the Camoped active motion device will provide outcomes equal to or superior than the CPM. 110 patients will be randomized during the course of the study. Participation lasts approximately 4 weeks. Data for patients who begin the trial, but choose to drop out or are lost to follow up will not be included in analysis.

Patients who have elected to undergo surgery with one of the PIs, either a total knee replacement with Dr. Richard Scott or a partial knee replacement with Dr. Wolfgang Fitz, will be informed about the study and offered participation if they meet eligibility criteria. The PI will obtain written consent in the office for those who choose to participate. For participants, demographic data including height, weight, BMI, age and sex will be collected. Additionally, sit-to-stand, knee flexion, proprioception, strength and balance testing will be performed in the office by a physical therapist. Participant responses to the SF-36 physical and mental health surveys, knee function score, KSS and WOMAC questionnaires will also be collected.

Patients will be randomized to receive either the Camoped or CPM device after surgery. Patients will receive the device and its protocol for usage in the hospital following surgery. They will use the device for the duration of their hospital stay, and then take the device home. At home, patients will be asked to keep a daily diary tracking device usage as well as daily pain and medication intake. These results will be compared as part of the study analysis.

When patients return for their follow-up appointment four weeks after surgery, demographic data including height, weight, BMI, age and sex will be collected. Additionally, sit-to-stand, knee flexion, proprioception, strength and balance testing will be performed in the office. Participant responses to the SF-36 physical and mental health surveys, knee function score, KSS and WOMAC questionnaires will also be collected. These measures will be compared to the preoperative results.

Two-sample t-tests will be used to analyze the similarity between the two treatment groups before the intervention and to assess any differences afterwards. The Wilcoxon-Mann Whitney test will be performed as a non-parametric alternative to t-testing for any data sets found to be non-normal.

Data collection and management will be the responsibility of the PIs. All adverse events will be reported as necessary.

Inclusion Criteria:

• • At least 18 years of age

  • Undergoing unilateral knee replacement
  • If female, not pregnant
  • Agree to participate in the follow-up appointment
  • Understand and sign the informed consent form

Exclusion Criteria:

• Bilateral UKA or TKA planned
• Cannot use non-operated leg post-operatively to propel active motion splint, caused by neurological or muscular diseases such as complete or incomplete paralysis or other causes of weakness with an inability to bend or extend knee
• Loss of sensation of/in? operated or non-operated leg
• Received investigational articles <30 days prior to enrollment or was currently receiving investigational products or devices.
• Below or above knee amputations of non-operated leg
• Below knee amputation of operated side
• Chronic pain syndrome with inability to walk and/or use active or passive motion device post-operatively
• Patients taking chronic narcotics and/or are taking more than 10mg codeine per day, or any Hydrocodone, more than 200 mg of tramadol, or any other narcotics prescribed for moderate to severe pain
• Patients involved in pain clinics for chronic pain, or pain that is not related to the knee
• Diagnosis of knee disorder other than osteoarthritis, post-traumatic osteoarthritis, gout, pseudo gout
• Inability to walk due to disorders unrelated to the knee (e.g., hip disorders, spinal stenosis, paralysis, hemiparalysis)

137 patients agreed to participate, 27 did not meet the inclusion criteria and 110 signed the informed consent form. Following allocation to their group, we excluded 24 patients (20 using CAM and 7 CPM) who did not finish the study due to non-compliance, leaving a total of 83 patients.

Adverse event data was collected while patients were participating the study. Patients were followed up at 4 weeks after surgery and any adverse events were noted.

We ran into an unexpected problem in recruiting patients for this study. Many did not want to participate in this study, as they did not want to use the passive device and were not willing to use it 4 hours each day.