To explore the clinical efficacy of using a tunnel beneath the paratenon to repair chronic Achilles tendon rupture of Myerson type Ⅱ.

From August 2008 through January 2018, 19 patients with chronic Achilles tendon rupture were treated with a self-designed minimally invasive suture technique at Department of Orthopaedics, The Fourth Medical Center, General Hospital of PLA.They were all male, aged from 25 to 64 years (average, 40.4 years).The left side was injured in 12 patients and the right side in 7.The duration from injury to surgery ranged from 28 to 120 days, averaging 60 days.The Achilles tendon defects averaged 3.84 cm.Their clinical diagnoses were confirmed by positive results of clinical examination and magnetic resonance imaging (MRI) scans.After a 2 cm transverse incision was made at the proximal side, the proximal stump beneath the paratenon was adequately released with a periosteum elevator.The proximal stump was sutured by the Bunnell method with an Ethicon-X519 non-absorbable suture under direct vision.After a 1.0-1.5 cm transverse incision was made, percutaneous Bunnell suture was performed at the distal side.The proximal stump was then introduced into the distal incision through the paratenon tunnel.After the affected foot was fully flexed, the 2 stumps were tied closely together and buried under direct vision.Early rehabilitation was encouraged after surgery.The clinical efficacy was assessed ac-cording to the ankle-hindfoot scores of American Orthopaedic Foot & Ankle Society (AOFAS) and the Arner-Lindholm evaluation criteria.

The 19 patients were followed up for 10 months to 9.5 years (average, 2.45 years).All the wounds healed at the first stage without any complications related to incision, sural nerve injury or tendon re-rupture.Their AOFAS ankle-hindfoot scores averaged 98.4, with 19 excellent cases; according to the Arner-Lindholm criteria, 13 cases were excellent and 6 cases good.Both of the e-valuation systems yielded a good to excellent rate of 100%.In the 3 patients who underwent isokinetic testing, there was no significant difference between the normal and affected sides in the peak value of flexion or in the total work of fatigue.

Using a tunnel beneath the paratenon is a good self-designed minimally invasive suture technique for chronic Achilles tendon rupture of Myerson type Ⅱ because it is simple and re-liable, and leads to limited tissue damage, adhesion or complications.

Achilles tendon; Tendon injuries; Surgical procedures, minimally invasive; Chronic