Partial Achilles tendon tears.
Persistent pain in the Achilles tendon is often caused by partial ruptures leading to a hypoxic state in the tissues, insufficient healing, and a remaining, immature, and painful scar. The rupture is caused by overuse and conservatively treated with orthotic devices to reduce tendon load and physiotherapy to correct training errors and strength the muscle-tendon unit. Significant partial ruptures seem to respond poorly to conservative measures and do not improve with time. Surgical treatment with excision of degenerated tissue which leads to complete pain relief and full restoration of function with long-standing effects in most cases is why persistent Achilles tendon pain due to partial rupture preferably should be treated surgically.
Achilles Tendon↗