Achilles Tendon is the largest and thickest tendon in the human’s body which can hold up forces up to 9 kN, similar to 12.5 times of the body weight [1]. It is approximately 15 centimeters long and connects the gastrocnemius, soleus and plantaris to the calcaneus. In spite of its strength, acute Achilles tendon rupture is the most frequently sports-related injury occurred in middle-age recreational sports players.
Several movements such as violent muscle contraction, direct trauma or long-standing tendonitis may lead to typical tendon rupture [2]. Other factors include aging, the usage of fluoroquinolone antibiotics, corticosteroids use, rheumatoid arthritis and gout [3].
Achilles tendon extracellular matrix have been observed to become weakened by the fluoroquinolone antibiotics, giving rise to less tensile tendon strength [3]. In addition, Corticosteroids, used to decrease tissue inflammation, also impede the formation of collagen and decrease blood supply to an already avascular structure [3]. In terms of aging, chronic degeneration of the tendon and failure of normal inhibitory mechanisms may occur during a person’s life time. The Tensile strength of collagen decreases as the reduction of blood flow of the susceptible region with age [4]. While aging, tissue also increase stiffness to decrease the ability to withstand repetitive stress which in return allow forceful and sudden contractions to tear the tendon [5].
The incident number of Achilles tendon rupture vary a lot continentally. The reported incidence in the literature ranges from 6 to 37 per 100,000 person-years [6,7].
In Canada, from 2003 to 2013, the incidence of acute Achilles tendon rupture in Ontario increased from 18.0 to 29.3 per 100 ,000 person-years [8]. In Taiwan, according to the National Health Insurance research databases and the data we acquired from interviewing surgeons, 5,600 patients suffer from acute Achilles tendon rupture annually
and the compound annual growth rate is approximately 5%. In terms of Japan and France, unfortunately, from the literatures and interview of local surgeons, there’s no epidemiology research conducted regarding Achilles tendon rupture. The incident rate in Japan and France are remain unknown.
There are mainly 2 treatment options including surgical and conservative approaches. Compare to conservative methods, operative treatment could significantly reduce the risk of re-rupture rate to 7% [9]. Operative treatments include conventional open wound repair, percutaneous methods and minimally invasive surgery. During open surgery, a 10 to 15 cm incision is made in the back of leg and the Achilles tendon is stitched together with Krackow suture. Although open repair surgery could reduce the re-rupture rate, it may lead to a significant increase in other complications such as poor wound healing, flap necrosis infection, and sural nerve injury, with a reported risk up to 21% [9]. To solve the high complication problems, percutaneous and minimally invasive methods were introduced. These methods vary with more complex repair tools and suture-passing techniques. However, the recent researches indicate a range of 0–27% of sural neuritis after percutaneous procedures [10,11]. For example, the Achillon limited open repair device (Integra Life Sciences Holding Corporation, Plainsboro, NJ) and the Percutaneous Achilles Repair System (PARS) Arthrex Device will create a 3 to 5-centimeter incision to insert the jig system to clip the rupture tendon [11]. This critical procedure may harm the periosteal vessels and cause sural nerve damage during surgeries [12]. In addition, these techniques cannot assure that the sutures are well positioned at the middle portion of the tendon, especially for the farthest suture, which may cause the suture to cut through during knot tying.
A novel ultrasound-guided minimally invasive surgery was invented by Taiwanese Orthopedic surgeons who we are cooperating with [13]. Ultrasound has great
advantages of no radiation, no tissue damage, and excellent soft tissue visualization.
With high-frequency resolution and real time ultrasonography, intraoperative ultrasound could be of assistance during minimally invasive surgery to avoid damaging sural nerves [14]. Comparing to other percutaneous treatments, this novel technique could reduce the wound size from 5 centimeter to approximately 1 centimeter [13]. With less wound size, the complications including re-rupture, wound healing and skin necrosis are 0%. Moreover, this novel surgical treatment could shorten the recovery and rehabilitation time and will be beneficial for elder or diabetes patients with poor healing.
However, few surgeons are aware of this novel technique. During our interview with over 10 orthopedic surgeons from Taiwan, Japan and France, they have a common concern regarding biomechanical strength test and the healing procedure. Plenty of researches have been indicating the biomechanical outcomes and knot strength in the load to failure test of percutaneous surgery have no significantly different comparing with the open Krackow suture [15,16]. However, the minimally invasive repair techniques demonstrated an increased susceptibility to early repair elongation [16].
These are based on the cadaveric study. Further in vivo test of postoperative protection for biological healing plays an important role.
Plenty of patients are still suffering from the Achilles tendon repair complications such as re-rupture, infection and worse wound healing situation. Therefore, with the GIP-TRIAD training, I am extremely excited to discover this unmet need and contribute myself to promote this incredible technique. This comprehensive report includes what I have done during 2 years of study and how I combine all the knowledge to propose a scientific pre-proposal and business plan regarding Achilles tendon minimally invasive medical device.