Episode 2 - The Background

The Background and History of the knee Problem.

I experienced knee buckling on my right knee some 18 months ago. It was a strange feeling as there was no pain and I was unable to simulate such loss of muscular control. Later, I felt pain whenever I jogged or played a round of golf. Usually, rubbing medicated oil and putting on a knee guard would keep the pain in check. I also started taking glucosamine and chondroitin sulphate supplements and also applied transdermal glucosamine cream to the knee. They helped to relief the pain somewhat, but these products are really costly. I decided to seek medical treatments when the knee started to lock up briefly in the bent position occasionally. Trying to straighten the leg to stand up would cause intense pain at the knee. Massaging the knee and relaxing the muscles would eventually ease up the locked knee. Again, I was unable to simulate the knee locking, no matter how hard I tried - it was as if nothing had happened and there was no pain afterward.

I was referred to a specialist consultant in NUH, an Assoc Professor, who specialised in orthopaedic, tissue engineering and stem cells. He examined my leg and told me that, based on the symptoms, it is likely to be knee osteoarthritis - the wearing out of or damage to the knee cartilage. Subsequent MRI and X-ray confirmed localised damage of the cartilage known as chondral ulcer. Cartilages are normally meant to last one's lifetime. However, diseases, trauma to the joints, high intensity & high impact activities and even obesity can aggravate the cartilage wear.

The Prof said that at my age, I was neither here nor there - too young for knee replacement and too old for tissue engineering, such as using stem cells or cultured cells. Normal age range for cells replacement is from 13 - 55 years old and knee replacement is usually for those above 65, as artificial knee can only last 10 - 15 years, shorter if the person is active in sports. Obviously, I'm outside these age ranges. Later, however, he asked if I'm prepared to try stem cells for the repair. There are special stem cells called mesenchymal stem cells (MSCs) which can be extracted from one's bone marrow, usually taken from the hipbone. The very small number of stem cells are cultured in the lab, multiplied into millions in number and then implanted back to the knee. The stem cells will eventually transform into new cartilage cells in the knee. I agreed without hesitation. He suggested monitoring my conditions for a short period. In the meantime, however, the episodes of knee locking happened more and more often and the locking up sometimes lasted 30 minutes or more. The Prof said that it was caused by broken fragments of cartilage in the knee and these would have to be removed under a key-hole surgery called Arthroscopy. In April 2007, I underwent arthroscopy and the Prof removed 3 pieces of somewhat rounded fragments, which he called 'meteorites' floating in the knee cavity. The fragments were probably damaged a long time ago, ground until somewhat rounded over many years. He told me later that he took the opportunity to harvest some chondrocyte (cartilage) cells to grow in the lab. He asked me to be prepared for ACI, Autologous Chondrocyte Implantation in 4 weeks' time. (Please see my post on 'What is ACI'). The surgery date was eventually fixed 5 weeks later, on 30 May 2007, provided of course, my harvested cells survived and had thrived in the bioreactor.

Click the links below from Arlington Orthopedic Associates to watch 3-D video animations of Knee Arthroscopy and Knee ACI.

Acknowledgements:

National University Hospital, Singapore. (http://www.nuh.com.sg/index/index.htm)
Stem cells. (http://www.nuh.com.sg/nuh_ortho/ortho/sports/stemcell.html)
Arthroscopy. (http://www.nuh.com.sg/nuh_ortho/ortho/sports/arthroscopy.html)

Arlington Orthopedic Associates. 3-D Video animations

Knee Arthroscopy. http://arlingtonortho.com/ka/

Knee ACI. http://arlingtonortho.com/aci/

Episode 1 - Introduction to this Blog

I created this blog to share my recent experience on the operation of my right knee. Many friends and colleagues have also been enquiring about my well-being and how I'm coping with the rehabilitation, and wishing me a speedy recovery. I really wish to express my heartfelt thanks to everyone for their concerns and wishes. Being a novice at blogging, I initially thought of setting this blog up as a private blog only for family, friends and colleagues to view, but my kids suggested that I should open it to anyone who might be interested in this medical procedure - that's what sharing is all about, isn't it?

I underwent an operation called knee ACI, Autologous Chondrocyte Implantation - this basically means taking out some healthy cartilage cells from your own knee, grow it in a lab, implant it back to repair the damaged portion of the knee cartilage, something like Cut, Grow & Paste. I shall post the background of my knee problem, what is ACI, pre-operation thoughts, the post op experience, both in hospital and at home and finally what to expect in the next few months, including some 50 references & links for further reading.

Episodes

1. Introduction to this Blog (this page)
2. The Background
3. Pre-Operation thoughts
4. D day - The Operation
5. The Day After
6. The Recovery
7. The Home Coming
8. A Feverish Nightmare
9. The Fever Pattern
10. Winning the Battle
11. Start of the Rehab
12. What's Next

Annexes

• Annex A - What is ACI
• Annex B - The Next Few Months (including references & links)
• Annex C - The Fever Chart

Annex A - What is ACI ?

What is knee ACI – it’s the acronym for Autologous Chondrocyte Implantation. It is now considered a fairly established medical procedure to repair damaged or partially worn knee cartilages, although not many people have heard of it. Knee cartilages are avascular, meaning they have no blood vessels and they are, therefore not able to be regenerated by the body. Autologous means using one’s own cells; chondrocytes are specialised type of cells that form the cartilage; and implantation means to patch new cultivated cells back into the knee. This is a two-stage surgery process, where healthy cells are first scraped off from non-weight bearing area of cartilage surface using a technique called arthroscopy. Two keyholes are opened up, one to insert a fibrescope lightsource & camera and the other to insert the tool for the biopsy where about 300mg or some 10,000 cells are harvested. While examining the interior of the knee compartment, any broken fragments of cartilage are removed. The damaged area, known as chondral ulcer, is cleaned up and the jagged edges are trimmed (debrided), to prepare the area for the next stage.

The harvested cells are then taken to a lab, together with a substantial amount of the patient’s blood (about 70 ml) to grow in a special nutrient rich bioreactor. Normally, within 3 to 4 weeks, the 10,000 cells would have multiplied to some 10 to 12 millions cells and ready for implantation. NUH is currently the only medical facility in this region with a cells culture lab, Therapaeutic Tissue Engineering Laboratory (TTEL), to grow these cells. Previously, they are sent to US, UK, Sweden, Japan or Australia for the culture. In my case, owing to the surgeon’s fully booked schedule, my operation was some 5 weeks later. My ulcer was found to be larger and deeper than originally estimated and I probably needed those additional millions of cells.

During the second stage of the surgery, which is an open knee surgery, 2 incisions are made. The major incision is for the main surgery – about 100mm to 150 mm long over the kneecap, to expose the damaged ulcer. In my case, it is at the end of the thighbone, a femoral chondral ulcer. The surgeon then measured and made a template in the exact shape of the ulcer. He then opened a second incision on the shinbone (tibia); about 50 to 70 mm long, to expose the periosteum, the membrane or skin that covers the bone. Using the template created earlier, he cut out a slightly larger layer of the periosteum and immediately sutured this on the ulcer. Bone glue made from one’s own blood was used to cement over the sutured area to seal the overlap. To ensure that the newly created pouch is fully watertight, pressurized sterile saline water was injected into the pouch to test for leak (something like hydrostatic test used in industries). Once no leak was detected, the saline water is drained and the prepared cultured cell is implanted into this pouch using a syringe. The pouch acts as the formwork where the cells continued to grow and eventually hardened to form the newly created cartilage. Both the pouch and the incisions are then sutured or stitched up. The photos below showed the ulcer before the repair and the fully regrown cartilage.

Acknowledgements:

National University Hospital, Singapore, Dept of Orthopaedic Surgery. (http://www.nuh.com.sg/nuh_ortho/ortho/sports/cartilage.html)

The Center for Orthopaedics and Sports Medicine, Atlanta, Georgia, USA. (http://www.arthroscopy.com/sp08001.htm)

Brown University, Rhode Island, USA. (http://biomed.brown.edu/Courses/BI108/BI108_1999_Groups/Cartilage_Team/christine/HowitWorks.html)

Arlington Orthopedic Associates. 3-D Video animations
Knee Arthroscopy. http://arlingtonortho.com/ka/
Knee ACI. http://arlingtonortho.com/aci/