Osteoarthritis occurs most commonly in the knee joint and causes significant pain and disability in over 10% of people over 60.  Many people immediately think of knee replacement as a solution. However, for people under 70 (Bayliss 2017) who maintain a more active lifestyle the lifetime risk of revision surgery is high. Men in their early 50s have a 35% risk for needing a second knee replacement. The median time to revision surgery for people who had knee replacement aged 60 or younger was only 4·4 years.

An alternative procedure called ‘knee joint distraction’ (KJD) has emerged for treatment of knee osteoarthritis symptoms, to delay knee replacement. ‘Distraction’ means ‘creating a space’ between cartilage of the top & bottom knee bones by gently pulling them apart using a ‘distraction device’ to eliminate mechanical contact between the degenerating articular surfaces.  Joint distraction is indicated for patients under 65, under 120 kg, with end-stage (predominantly tibiofemoral) knee osteoarthritis, and Kellgren and Lawrence scores between 2-4.

KJD is based on the hypothesis that OA cartilage has some reparative activity, and that this reparative activity may become effective when the damaged cartilage is mechanically unloaded for a time, preventing further wear and tear, while the intermittent synovial fluid pressure changes essential for the nutrition of cartilage are maintained.

Joint distraction increased mesenchymal stromal stem cell adhesion to cartilage, a process necessary for colonization and differentiation of these cells leading cartilage repair.³⁵

KJD also reduced

1. inflammatory chemicals in the knee such interleukin-1ß
2. type X collagen cartilage cells chondrocytes that lead to cartilage ossification
3. matrix metalloproteinase 13 – cartilage degrading enzymes

suggesting reduced inflammation and cartilage destruction, as well as cartilage rebuilding.

The procedure takes 30-45 minutes. It involves surgical placement of eight bone-pins, 2 on each side of the femur shaft, same for the tibia, leaving the joint itself undisturbed. Two distraction devices are applied between the femur and tibia pins, one on the lateral side, the other on the medial side of the knee (see picture). Once in place, 2 mm of distraction is applied, then another 3 mm over several days. Knee cartilage is completely unloaded (you walk on crutches) for 6 weeks then the device & pins are removed in day-care under anaesthesia, rehab starts-leg fully loaded, and results are noticeable in 2 months.

The procedure comes with 3 main risks:

1. infection at implants (effectively managed with antibiotics)
2. pulmonary embolism (managed with prophylactic anticoagulants) and
3. limited knee flexion (very rarely, self-resolves)

The procedure has a success rate of 75% increasing cartilage thickness by 1mm. A recent systematic review found joint distraction a viable alternative for certain patients. Clinical and structural benefits persisted for 9 years. Most patient indicated that they would have the procedure again. A great advantage is that having KJD avoids total knee replacement but does not prevent the use of this or any other knee surgery options later if & when required. Similar procedures are also available for hip and ankle joint OA.

 

Article Written + Submitted by:

Andreas Klein Nutritionist + Remedial Therapist from Beautiful Health + Wellness
P: 0418 166 269