From the Guidelines
The usual weight-bearing status after a Total Knee Arthroplasty (TKA) is immediate full weight-bearing as tolerated, as evidenced by the postoperative management in the study by 1, where twice daily postoperative physical therapy with full weight bearing was initiated on the day of the surgery. This approach is supported by the fact that the patient in the study had no postoperative complications and required no blood transfusions, and was able to ambulate independently without assistive devices at 3 months postoperatively. The use of full weight-bearing as tolerated promotes better outcomes by enhancing blood circulation, preventing muscle atrophy, improving proprioception, and accelerating the recovery process.
- Key benefits of immediate full weight-bearing include:
- Enhanced blood circulation
- Prevention of muscle atrophy
- Improved proprioception
- Accelerated recovery process
- Reduced risk of complications associated with immobility, such as deep vein thrombosis and joint stiffness
- The modern implant designs and fixation techniques used in TKA are engineered to withstand these forces, making immediate weight-bearing safe for most patients, as seen in the study by 1, where the patient was able to maintain a regular self-initiated exercise program at the local gym without any issues. However, the specific weight-bearing protocol may be modified based on individual factors such as bone quality, surgical approach, implant stability, or concomitant procedures, so patients should always follow their surgeon's specific instructions.
From the Research
Weight-Bearing Status After Total Knee Arthroplasty (TKA)
- The usual weight-bearing status after a Total Knee Arthroplasty (TKA) can vary depending on the patient and the surgeon's instructions.
- According to a study published in 2013 2, weight-bearing exercises are tolerated by patients in the early stage after TKA, and physiotherapy that focuses on learning different ways of walking through practice may be a plausible way to train patients after TKA.
- However, another study published in 2023 3 found that compliance to prescribed weight-bearing restrictions after TKA was low, with 84% and 90% of patients overloading the affected limb during every step at two different measurement times.
- The same study 3 also found that patients older than 65 loaded the affected limb on average 17% and 34% more than their younger counterparts did.
- A study published in 2007 4 found that patients who had undergone total hip arthroplasty (THA) with trochanteric osteotomy did not achieve partial weight bearing at a specific target load when given verbal instructions, and loaded the operated leg higher and more frequently above the target load, especially when walking at home with no supervision of a physical therapist.
- Another study published in 2020 5 found that weight-bearing asymmetry correlates with patient-reported outcomes (PROMs) after TKA, and that the more symmetry in muscle-force and weight-bearing is found preoperatively, the better the PROMs will be at 6 months after surgery.
Factors Influencing Weight-Bearing Status
- Age: Patients older than 65 may have more difficulty maintaining partial weight-bearing after TKA 3.
- Body weight: The achievable load reduction is determined by the patient's body weight 3.
- Physiotherapy: Physiotherapy that focuses on learning different ways of walking through practice may be a plausible way to train patients after TKA 2.
- Supervision: Patients may load the operated leg higher and more frequently above the target load when walking at home with no supervision of a physical therapist 4.