No marked benefit seen to continuous passive motion following TKA

Issue: April 2013

CHICAGO — One of the largest, randomized prospective reports on continuous passive motion shows no significant advantages in its use after total knee arthroplasty for postoperative range of motion, patient-reported pain or other studied markers for recovery.

“[Continuous passive motion] CPM provided no benefit to our patients,” Clifford K. Boese, MD, said during his presentation of a series of total knee arthroplasties (TKAs) performed by a single surgeon, using the same type of posterior stabilized knee implant for all patients who also underwent the same physical therapy regime. He added, “CPM adds to the cost of knee replacement surgery,” noting that is institution was spending more than $1,800 per month for the rent of CPM machines at the time of the study.

Boese and colleagues compared the pain, swelling, postoperative drop in hemoglobin, hospital length of stay and degree of flexion/extension achieved in 160 patients who underwent TKA followed by:

moving CPM of 0° to 110° that started immediately upon arrival to the orthopedic floor and continued for a minimum of 5 hours per day for minimum of 2 days until the patient achieved 90° of active flexion;
static CPM in which the operative leg was held stationary at 90° for a minimum of 8 hours and then moved from 0° to 110°; or
no CPM.

The groups had similar demographics for age, body mass index, limb girth, preoperative hemoglobin, and preoperative range of motion.

After treatment, the investigators found no significant differences between the groups for flexion or extension.

“Although the group that had no CPM tended to have the lowest pain scores, the difference was not statistically significant at any point,” Boese said. He added, “Actually, the group that did not receive CPM had the shortest hospital length of stay, and the group that was kept flexed overnight had the longest — that was significant.”

There was a smaller decrease in hemoglobin levels in the static CPM group, but this finding was not statistically significant.

“There was some increased swelling in the moving CPM group, but we did not feel that was clinically significant,” Boese said.

Reference:

Boese CK. Paper #348. Presented at: American Academy of Orthopaedic Surgeons Annual Meeting; March 19-23, 2013; Chicago.

Disclosure: Boese has no relevant financial disclosures.