An MUA is a surgical technique to break up fibrous materials, adhesions, and scar tissue around the knee joint. The surgeon will perform controlled joint mobilizations and manipulations to the knee by placing the knee in different positions and applying pressure. The surgeon will also take the knee through its full available ROM of knee flexion and extension.

The MUA is a surgical procedure performed while under anesthesia, usually a general anesthesia, but IV administration is also used.

Thankfully, the prevalence of diagnosed significant knee stiffness following surgery is low. One study by Kim et al. (2004) found that only 1.3% of individuals had diagnosed knee stiffness after surgery at 32 weeks post-op.

When is a MUA Appropriate?

MUA should be considered a last resort option after failed attempts at conservative treatment like active ROM exercises. Conservative options should be tried for a minimum amount of time after surgery. Most recommendations are to wait until at least 6 weeks postoperatively before a MUA is recommended, and the typical time frame for a MUA is 6-12 weeks post-op. 

Two studies, one by Desai et al. (2013) and Choi et al. (2015) assess the efficacy of performing more than one, or repeated MUA. Both studies concluded that there was no additional benefit in terms of knee ROM with repeated MUA procedures.

What are the Benefits?

The main benefit of a MUA is decreased knee stiffness and improved overall ROM of the knee. These improvements are usually noticed immediately after the MUA is performed, and although a period of increased pain after the procedure is normal, your recovery time is not significantly impacted in most cases.

Are there risks?

Due to developments in treatment technique, MUA is relatively safe with minimal risks. There is a risk of fracture to the bones that comprise the knee joint. This risk is increased with older age, frail bones, or osteoporosis. There are also some inherent risks with the use of anesthesia that you should be aware of.

1. Kim, J., Nelson, C. L., & Lotke, P. A. (2004). Stiffness after total knee arthroplasty: prevalence of the complication and outcomes of revision. JBJS, 86(7), 1479-1484.
2. Mohammed, R., Syed, S., & Ahmed, N. (2009). Manipulation under anaesthesia for stiffness following knee arthroplasty. The Annals of The Royal College of Surgeons of England, 91(3), 220-223.
3. Mamarelis, G., Sunil-Kumar, K. H., & Khanduja, V. (2015). Timing of manipulation under anaesthesia for stiffness after total knee arthroplasty. Annals of translational medicine, 3(20).
4. Wied, C., Thomsen, M. G., Kallemose, T., Myhrmann, L., Jensen, L. S., Husted, H., & Troelsen, A. (2015). The risk of manipulation under anesthesia due to unsatisfactory knee flexion after fast-track total knee arthroplasty. The Knee, 22(5), 419-423.
5. Desai, A. S., Karmegam, A., Dramis, A., Board, T. N., & Raut, V. (2014). Manipulation for stiffness following total knee arthroplasty: when and how often to do it?. European Journal of Orthopaedic Surgery & Traumatology, 24(7), 1291-1295.
6. Choi, H. R., Siliski, J. M., Malchau, H., & Kwon, Y. M. (2015). Effect of repeated manipulation on range of motion in patients with stiff total knee arthroplasty. Orthopedics, 38(3), e157-e162.