The Shelbourne Knee Center has been using the continuous passive motion (CPM) machine for all of our post-operative knee procedures and have not experienced the daily challenges or complications that we hear from many physical therapist in other facilities. Over the past 37 years, our office has been collecting data on post-surgical patients to determine best practices, and for evidence based treatment for postoperative rehabilitation. Initially, the CPM was used with all the post-operative ACL patients as it allows the knee to stay above the heart while patients are on bedrest. This prevents a hemarthrosis in the knee joint, which has secondary effects on improved range of motion, decreased pain and no quadriceps inhibition.


Our post-operative protocol includes a combination of modalities, physical therapy exercises, and pain medications that utilized for the primary purpose of preventing a hemarthrosis in the knee, which is the main culprit that causes pain and limitations in knee range of motion and leg function after surgery. The primary advantage of using a CPM post-operatively is that it allow the knee to stay above the heart while patients are on bedrest. This prevents a hemarthrosis in the knee joint, which has secondary effects on improved range of motion, decreased pain and no quadriceps inhibition. The CPM moves the knee 0 degrees to 30 degrees, 24 hours a day, 7 days a week while on bedrest. Additionally, a mid-thigh TED hose stocking that is applied in the operating room along with a cryo-cuff to the knee joint. The patient and their caregiver are instructed prior to surgery on how to operate the cryo-cuff and instructed to change the water out of the cuff every hour during the first week to allow for constant compression to the joint capsule, and cold/compression at least 15 minutes out of every hour of the day. The cuff is to come off the knee when the patient gets up to go to the bathroom, at least 4 times a day, and it comes off when doing a series of exercises three times a day. This allows for a more normal gait pattern and avoids onset of compensatory patterns in gait. Patients may use an assistive device as needed for safety. Otherwise, the patient is educated on staying on bedrest with the leg elevated above the heart in the CPM during the first 7 days post-operative. Patients are instructed in a series of exercises to be done 3 times/day and log sheets provided to make sure they are completed and document range of motion using a yardstick.


Another component of our post-operative protocol is preemptive pain management, which is defined as prevention of pain prior to surgical insult. Our current protocol evolved since the 1980 is starting with the use of IM Demerol to using IM Ketorolac every 6 hours, and eventually to using continuous infusion IV Ketorolac, which is our current pain management approach. Ketorolac is a preemptive pain management drug that prevents prostaglandin synthesis when it is administered before surgery, causing a decreased in local inflammatory reaction. Our research showed that there was no kidney or liver complications noted, and it allowed for smoother pain control than using injections.


This approach to managing and preventing a post-operative hemarthrosis has been used at our facility for ACL reconstruction patients since 1984. Shelbourne and Nitz published the results of using this protocol with an “accelerated rehabilitation program after ACL reconstruction”, and the results indicated a quicker return of range of motion and strength, with no loss of stability and few complications, which inadvertently lead to quicker return to sport. Other subsequent studies have gone on to find that achieving normal knee range of motion post-operatively is vital for achieving not only the best subjective outcomes but for reducing the risk for developing osteoarthritis in the long-term after surgery. We have continually analyzed our results over the past 37 years, and have made a few modifications in our post-operative rehabilitation protocol in order to continue to make improvements in our patient’s overall outcomes. We have also tracked pain levels, need for pain medication and long-term outcomes with range of motion, strength and function with not only the ACL patient populations, but with our total knee arthroplasty procedures, beginning in 2007. As we have collected data from the TKA patients, we are finding the same benefit with no hemarthrosis, decrease pain levels, decrease need of pain medication, increased return of range of motion and no quad inhibition. Patients are walking without the need of any assistive device sooner.

A retrospective study was done looking at pain management with the progression of Demerol to IV Ketorolac and found that the group that received continuous IV Ketorolac had a statistically significantly lower mean narcotic doses per day and per hour, shorter hospital stay, and lower hemovac output. (p<.05).

We felt the pain management with our ACL patients was so effective that it should be just as effective with the total knee patients. However, the practice of bedrest and use of ketorolac raised concerns because this was not considered standard of practice for this age population. These concerns included keeping elderly patients on bedrest lead to increased risk of DVT (blood clots), GI ulcerations, coronary syndromes, or impaired renal function. To determine whether our protocol caused increased complications, a retrospective study to analyze our total knee data of pain medication use, pain level and complication rate verses another group of patients who were mobilized every day and who had an Opioid pain control. The results of this study showed that patients in the ketorolac/bedrest protocol had statistically significantly lower pain scores and less narcotic use than the opioid/early ambulation protocol. Patients in the continuous IV Ketorolac group received 81% fewer opioids in the first 24 hours and 95% less in the second 24 hours. The Ketorolac group also had a statistically significantly lower percentage of those suffering with respiratory depression at 5.2% compared to 25.3% in the opioid group. Respiratory depression is defined as less than 8 breaths/minute requiring Naloxone administration. There were six patients in the opioid group for whom Naloxone was administered and none in the Ketorolac group. For the 1119 patients who underwent a TKA surgery and followed our post-operative protocol between 2007 and 2018, 3 patients suffered a DVT. Therefore, our treatment approach of keeping the patient on bedrest and elevating in the CPM does not lead to increase rate of DVT.

Because our philosophy has always put range of motion first with our rehabilitation programs, we feel that there should not be any limitations for achieving full, symmetrical range of motion with our ACL patients and feel there should not be any limitations to our TKA population as well. Of 1029 TKAs in 841 patients, there was a mean age of 65.0 with 619 unilateral patients, 157 bilateral patients, and 96 staged procedures and we were able to collect 1 year objective data, or greater on 60%. The post op complications included 11 (1.2%) manipulation for flexion loss, 10 (1.1%) infection, and 3 quad tendon ruptures. Pre-operative knee extension showed 62% had 0 degrees or some degree of hyperextension, compared to 91% had 0 degrees of extension or hyperextension at 2 years post op TKA. With flexion range of motion, the mean flexion range of motion is 121 degrees pre-operatively and the mean range of motion 2 years post operatively was 123 degrees.

The following chart shows the percentage of patients with KOOS (Subjective ratings) scores within the normal range at 1-year post operatively.

Pain Symptoms ADL Sport QOL
93% 84% 96% 90% 91%


Effective pain management in the first week using the TED hose, staying on bedrest with the leg elevated in the CPM 24 hours a day for 7 days, using a cold/compression device, and doing exercises 3 times per day in bed allows us to be aggressive with achieving full range of motion quickly after surgery. A major component to our perioperative rehabilitation program with both our ACL and TKA patients is the time we spend with patients pre-operatively to achieve the best range of motion possible before surgery. The physical therapy sessions on obtaining knee extensions first, then flexion, and lastly increasing strength. A previous study of 450 of our osteoarthritic patients showed that our pre-operative rehabilitation gave great relief of pain and symptoms, and 76% decided they did not need TKA surgery. Patients who go on to have TKA surgery receive the benefit of improved range of motion before surgery, which has been found to correlate with improve range of motion after TKA surgery. Our experience with seeing patients for second opinions, and talking with other orthopedic surgeons, is that most surgeons do not know that range of motion can improve in an arthritic knee. Most patients, who are not happy with their TKA after surgery, typically demonstrate joint stiffness and weakness. We believe our patients are an active participant in their rehabilitation process and it is the responsibility of the physical therapist to educate the patient and the orthopedic surgeon on how physical therapy can benefit their osteoarthritic knee patient; both prior to surgery and post-operatively with an emphasis on keeping patients down, preventing the hemarthrosis, and not getting them up to walk same day of surgery.