PT Tip of the Month Archive

Total Knee Replacement (TKR)

Total Knee replacement, or knee arthroplasty, is a surgical procedure to replace the surfaces of the knee joint to relieve pain and disability as result of osteoarthritis. For a better understanding of osteoarthritis please see last month’s Tip of the Month: Osteoarthrtis.

Picture 1: total knee replacement mechanism

Surgical intervention for osteoarthritis is indicated for the following examples:

  • Severe joint pain with weight bearing or motion that compromises functional abilities
  • Extensive destruction of articular cartilage of the knee secondary to advanced arthritis
  • Gross inability or limitation of motion in the knee
  • Marked deformity of the knee
  • Failure of non-operative management or a previous surgical procedure

Picture 2: X-ray from the front and the side of knee following a TKR

There are many types of components and techniques that may be used by the surgeon. Picture 1 illustrates the most common type of knee component utilized. The decision to use a particular component or technique is dependent on the needs of the patient and the amount of damage within the knee.

Pre-operative care

Pre-operative care revolves around education of the patient’s condition and post-op expectations and prognosis; as well as improving strength, flexibility, aerobic fitness and gaiting training with the assistive device to be used following surgery. In a study by Mizner et al. entitled, Preoperative quadriceps strength predicts functional ability one year after total knee arthroplasty quadriceps strength was found to play a dominant role in predicting one-year functional measures. Patients who had stronger quadriceps strength before surgery had better outcomes than patients with weaker quadriceps.

Post-Op care

In most cases, acute care in the hospital will begin the day after surgery. Acute care will focus on decreasing pain and swelling, early weight bearing, gait, functional mobility (i.e., stairs, bed mobility) and exercises to gain range of motion and muscle control. The physician may also prescribe a continuous passive machine (CPM), which assists to passively stretch the knee to gain range of motion (see picture 3). If the physician prescribes a CPM, in most cases, it will be continued to be use for 1-2 weeks post-op. The goal of acute care is improve the patient’s functional status so they can independently maneuver within their home. In most cases this includes: ambulation, getting into and out of bed, and ascend and descend stairs.

Picture 3: continuous passive machine (CPM)

Following 3-5 days of acute care, most patients are discharged to their home with nursing and physical therapy home care and will be given a discharge plan. This discharge plan is physician specific and will contain information pertaining to activities the patient may or may not perform at home (i.e., guidelines for driving). The focus of treatment at this phase of care will be to continue to manage pain and swelling, increase knee range of motion, strength and aerobic fitness. The nurse and/or physical therapy will also evaluate and improve safety within the home. Home care will continue for 1-2 weeks, to help manage the patient. In some cases, patients that are not safe for a home discharge following acute care, will be admitted to an inpatient rehabilitation or skilled nursing facility to continue to improve independence with functional tasks for a safer discharge to their home.

When home care ends, most patients will be prescribed outpatient physical therapy. The focus of treatment at this point of recovery will revolve around joint stretching and mobilization, exercises in weight bearing, gait training to decrease the need for assistive devices, and balance training. Patients are seen in the clinic 2-3x per week to perform these treatment techniques. A home exercise program (HEP) also be prescribed, which will be performed 1-2 times per day, and will include exercises to improve balance, strength, range of motion and aerobic fitness.

As progress is made physical therapy will evolve with a focus to continue to improve the patient's functional status. It may take at least 3 months postoperatively to increase strength in the quadriceps back to a preoperative level.

If you experiencing signs and symptoms of osteoarthritis or will be undergoing a total joint replacement procedure and would like to be scheduled for a physical therapy evaluation, please contact 617-232-PAIN (7246) for our Brookline office and 617-325-PAIN (7246) for our West Roxbury office.

33 Pond Avenue, Suite 107B Brookline, MA 02445 Tel: (617) 232-PAIN (7246) Fax: (617) 232-5196
1208B VFW Parkway, Suite 202 West Roxbury, MA 02132 Tel: (617) 325-PAIN (7246) Fax: (617) 325-7282