The purpose of this blog is to discuss the role of Compression Therapy (CT) in reducing swelling after Orthopaedic peripheral joint surgery. Most literature on this topic investigates the role of compression on conditions of chronic oedema (swelling lasting longer than 3 months) eg. Lymphodaema and Venous Insufficiency. In these chronic conditions CT is the “Gold Standard” in long term treatment.
An electronic literature search on Pubmed, Cinahl, Amed, Medline, and SportDiscus investigating Compression Therapy in Orthopaedic Joint Conditions produced studies on Total Knee Joint Replacement.
Cheung et al (2014) looked at the effects of compression bandaging versus crepe bandaging after Total Knee Joint Replacement (TKJR). Patients in the compression bandaging group were significantly more likely to be discharged with a walking stick rather than a rollator frame. They also demonstrated greater improvements in Flexion ROM and Straight Leg Raise. Charalambides et al (2005) used compression bandaging from toe to mid thigh and found faster recovery after TKJR, Greater ROM and shorter hospital stay.
However, Munk et al (2013) in a Randomised Controlled Trial of 88 patients showed no significant difference using medical elastic compression stocking after TKJR. Smith et al (2002) found no significant difference between compression bandaging and cold therapy after TKJR.
Evidence in the literature, directly looking at TKJR, is conflicting. The form of CT used in these studies is not consistent. It is useful to examine the current concepts surrounding Compression Therapy (CT) to better understand how compression could be used more effectively in Post Operative conditions.
Lymphatic and Venous System
In our body the Lymphatic and Venous systems are responsible for returning Lymph and venous blood back to the heart for recirculation around the body https://youtu.be/I7orwMgTQ5I
Lymph fluid is a fluid that forms in our body and surrounds all our body’s tissues. Extra fluid that comes from the body’s tissues drains into the Lymphatic system.
Compression acts as a cylinder around a limb. Zuther (2014) explains how the increased tissue pressure provided by external compression reduces the amount of fluid leaving the blood capillaries into the tissues and increases the return of tissue fluids back into the blood and lymph capillaries, thus reducing the amount of fluid in the tissues. External Compression is also thought to improve the function of valves in lymph and venous blood vessels making them more effective at removing fluid from tissues.
The importance of muscle contraction and joint motion combined with compression, to propel fluid back to the heart, is significantly highlighted.
The science
The pressure a compression garment exerts on the surface of the skin is called Interface pressure. There are two laws which form the basis of CT; Interface pressure will increase if the size of the limb increases (Laplace’s Law), and the compressive force of a garment around a limb is exerted internally on a one to one ratio (Pascal’s Law). These Law’s help us understand what happens to compression if a limb increases in size and how much internal compression it can create.
Compression garments will exert pressure at rest (Resting Pressure) and a different pressure when walking (Working Pressure). Working Pressure would be greater than Resting Pressure when walking.
It is important compression is comfortable when at rest and walking by choosing the correct type of Compression Garment. Compression Garments can be divided into two catagories; 1. Inelastic or short stretch (stiffer fabrics and higher Static Stiffness Index, SSI) and 2. Elastic or long stretch (lower SSI)
Short stretch compression can expand between 30-60% of its length when pulled. It is designed to increase compression with walking (Increase Working Pressure) and decrease compression at rest (Reduce Resting Pressure). As it does not stretch much it can limit oedema formation. This Inelastic property also creates the greatest inward pressure on the veins when walking and increases venous return.
Long stretch compression will change with walking and rest and is best used in situations where the calf muscle pump is not used regularly (Immobile patients).
These types of garments come as Circular knit or Flat knit. Circular knit garments are produced like a tube. Flat knit garments are sewn together with a seam. Flat knit garments are thicker, can provide greater compression, and are more comfortable around the holding (top) band of the garment.
There are some products which combine inelastic and elastic compression (Wraps). This allows for compression to be adjusted if oedema fluctuates and provides a better fit of the garment around the limb at all times.
Compression can be contraindicated in conditions where blood flow in the limb is already compromised. To ensure safely for every patient undertaking CT a medical profession can check circulation in the limb before applying CT.
To check circulation in a limb a test used to measure Ankle- Brachial Pressure Index (ABPI) is possible. Guidelines suggest an ABPI of greater than or equal to 0.8 is required if using compression of 30-40mmHg. It should be 0.8 to 0.6 for 25-35mmHg. Compression should never be applied on patients with an ABPI of less than 0.6. An ABPI of 0.5 indicates significant arterial disease and requires referral to a Vascular Consultant. To measure ABPI you require Doppler Ultrasound https://www.nursingtimes.net/clinical-archive/nutrition/doppler-assessment-calculating-an-ankle-brachial-pressure-index/205076.article If testing ABPI is not practical Class 1 compression could be used with a complete Holistic assessment. Rivolo (2016) has produced clear guidelines and a traffic light system for carry out a comprehensive Holistic assessment.
Classes of Compression Therapy
The amount of pressure CT creates can be catagorised into 3 or 4 classes. For Graduated Compression garments the peak level of compression starts at the ankle and reduces towards the knee and hip. Typically, the suitable level of Compression for Orthopaedic conditions is 20-30mmHg.
Comparison of compression standards
Class I Class II Class III Class IV
British Standard
(BS 66112:1985) 14–17 mmHg, 18–24 mmHg, 25–35 mmHg, Not reported
French standard
(ASQUAL) 10–15 mmHg, 15–20 mmHg, 20–36 mmHg, >36 mmHg
German standard
(RAL-GZ 387:2000) 18–21 mmHg, 23–32 mmHg, 34–46 mmHg, >49 mmHg
Just as important as the type and class of compression garment is the correct size of the compression garment. Specific measurements of the leg are required to obtain the correct size. With a poorly sized Compression Garment there is a risk of Reverse Pressures in the leg. Often a sign to look for is an indentation in the skin above the holding band of the stocking. It is important to monitor the leg once Compression garments have been applied.
Clinical Application
TED Stockings are usually the chosen form of compression after an operation https://tinyurl.com/y9ekhauv Ted Stockings are clinically proven, in peer reviewed published studies, to reduce the risk of DVT. They provide graduated compression to improve blood circulation.
There is a popular phrase “TEDs are for beds” because TED stockings provide low level compression (8-15 mmHg) and are designed for patients who remain in bed. They are customarily used during Hospital Stay, and after long surgery, such as pelvic and leg surgery lasting longer than 1 hour.
TED stockings do not provide enough compression for patients who are standing, walking or sitting. In these situations Compression garments should start at 20-30mmHg and can go higher if required.
Patients in TED stockings can find them difficult to use. They complain of the difficulty putting them on, being uncomfortable, and not staying securely in place. They become even more difficult to put on if reaching the toes is troublesome or hands are arthritic and weak. This is not a hassle free when in hospital or convalescing in a rehabilitation facility as nursing staff can put TED stockings on or take them off. It is a problem once patients are at home by themselves.
Considering the amount of compression TED stockings produce and the problems using them I ask the following questions…If we want to reduce swelling on an operated limb are TED stockings appropriate when a patient is now walking and, if not, what other options are available and which are more practical to use?
Tune in for next weeks blog…for the answer and ideas on practical application of Compression Therapy in Post Operative conditions.
