According to Dr Tang Wai-man, a specialist in orthopaedics and traumatology at the Hong Kong Sanatorium and Hospital, the Achilles tendon is the most troublesome part of the human anatomy. The tendon earns its name from an ancient Greek myth about the warrior Achilles, whose mother dipped him into the Styx river to try to make him invincible. However, because she held his heel while immersing him in the magical waters, a small vulnerable spot was created. Achilles was later killed by a shot in the heel from a poisoned arrow.

Doctors know that the Achilles' tendon is vulnerable, not only because it has to bear up to 12 times a person's weight when they are running or jumping, but also - and more importantly - because blood flow to the heel area is poor. Sub-optimal blood flow to any area impedes healing and creates problems.

The last time Chung had to recover from an Achilles' tendon rupture, he spent three months hobbling around with his foot in a cast and developed deep vein thrombosis (DVT). Hence, he knew he needed his loved ones near during recovery to make the uncomfortable road ahead more bearable.

So Chung, who divides his time between Canada and Hong Kong for work, chose to return to the city to stay with his family during the treatment. The medical staff at the Vancouver resort bandaged his ankle tightly to immobilise it, thereby minimising movement and pain for his long trip home. Back in Hong Kong, he consulted Tang.

Tang was a little surprised that Chung experienced the tendon rupture while skiing because the sport does not require the typical strains and jerky movements that usually precede a tear.

When examining Chung's heel area, Tang found a gap where the tendon should have been. Upon squeezing Chung's calf muscle, there was no movement in his left foot when there should have been a slight flexing of the foot if the Achilles' tendon was intact. The connection between foot and calf had indeed been severed.

The ruptured tendon needed to be repaired. Ten years earlier, the surgery to repair Chung's tendon in his right foot left a 6cm wound in his ankle. The extra trouble with a long wound in this area was not simply the slow rate of healing caused by poor blood flow. Poor blood circulation to this area meant the injured skin might not get the nutrients and oxygen it needed to heal, leading to death of the skin tissues in a condition called skin necrosis.

However, minimally invasive tools and techniques now enabled the torn ends of the tendon to be reattached with only a 2cm-long incision, minimising healing time, risk of infection and skin necrosis.

The reattachment process was a delicate one as Tang had to ensure the two ends of the tendon were stitched so they just touched. An over-tight repair could result in another rupture.

Because the newly repaired tendon was fragile and prone to rupture, the whole foot and ankle area needed to be immobilised to enable the tendon to strengthen and heal. The improved tendon-repair techniques also meant that the healing time would be shortened from the three months of a decade ago to four weeks.

Immobilising the foot for an extended period also presented its dangers, as Chung found out previously when he developed DVT. In normal situations, contractions of the calf muscle help pump blood through the veins in the lower legs. This mechanism is especially important in promoting blood flow because the lower legs are so far away from the pumping action of the heart.

When the calf muscles are immobilised, the pumping action of the muscle is stilled. This results in slow blood flow to the lower legs and increases the risk of blood thickening and clumping together to form a blood clot, Tang says. This blood clot can break away and travel in the bloodstream. If it reaches an artery in the lung, it can cause a blockage or pulmonary embolism, which can damage the lungs and other organs, and even cause death. DVT can also cause symptoms such as leg pain, redness and swelling.

Hence, patients recovering from Achilles' tendon reattachment surgery need to take anticoagulants or blood thinners. In the past, Chung had to stay in the hospital for a number of days while the anticoagulants were delivered through an intravenous drip. This time, he could continue taking anticoagulants orally at home, thereby reducing his hospital stay.

Four weeks later, his foot was freed from the cast. He had to undergo six weeks of physiotherapy to rehabilitate his leg muscles and help him to walk normally again.

Chung was delighted with the improved treatment for the tendon rupture. Tang advised him to ease back into light exercise after four months' rest. He also advises people to build up their muscle strength and exercise routines gradually, and avoid sudden and vigorous exercise that their bodies are not used to.