Neglected tendon ruptures present challenges for reconstruction. The most common neglected ruptures that you will encounter include the Achilles, tibialis anterior, tibialis posterior and the peroneal tendons.
As you know, chronic ruptures of the posterior tibial tendon rarely require tendon repair per se but go on to “flatfoot” surgery, which may include a tendon transfer along with osseous reconstruction. I want to focus on the tendons that would require surgical repair rather than bony reconstruction as in the foot with posterior tibial tendon dysfunction (PTTD).
The tibialis anterior rupture is not as common as other tendon ruptures around the ankle. In my experience, the tibialis anterior tendon rupture is typically secondary to a cortisone injection in the medial arch. Patients present with a slap foot/drop foot condition. Typically, patients receive a cortisone injection for an insertional tibialis anterior tendinitis. Other less common causes are spontaneous ruptures due to long-term prednisone use or in patients with collagen vascular diseases or rheumatoid arthritis. Magnetic resonance images (MRIs) typically reveal 5 to 6 cm of tendon retraction, which makes reconstruction tricky.
Similar to the tibialis posterior tendon, the peroneal tendons tend to rupture slowly over time. Typically in flatter feet, the tibialis posterior tendon is vulnerable for pathology whereas high arched feet tend to cause problems with the peroneal tendons. It is my experience that peroneal pathology such as partial tears, tendinosis and even complete ruptures are often relatively asymptomatic and are incidental findings on MRI.
The long extensor tendons of the ankle rarely rupture and when they do, it is usually a laceration injury. The extensor hallucis longus tendon is the most common long extensor tendon rupture that I see and it is usually from dropping broken glass or a knife on the foot.
For the Achilles tendon, there is usually an event causing the rupture. Patients will describe an audible “pop” and it feels like they were kicked or hit with something on the back of the leg.
When we repair neglected Achilles tendons, there are a number of options for addressing a large gap.
First, one can do a gastrocnemius recession to pull down the proximal stump of the tendon. Next, a flap-down technique can harvest the central portion of the aponeurosis and one can use that to augment repair. A flexor hallucis longus tendon transfer adds more strength to the Achilles, brings blood supply from the muscle and one can suture it side to side with the Achilles.
For the tibialis anterior tendon, one can perform a flap-down technique as well. However, the tendon becomes very narrow and is vulnerable to re-rupture. Another option is to obtain an autogenous tendon graft from the peroneus longus tendon in which one splits the tendon in half and utilizes a free graft.
There are various xenografts and allografts that one can use as well. Products such as GraftJacket (Wright Medical), Restore Patch (DePuy Orthopaedics) and the OrthADAPT Bioimplant (Synovis Orthopedic and Woundcare), just to name a few, are available for augmenting tendon repair.
I want to share with you my experience and personal feelings on the topic. First, I want you to think about bone repair. Most of us do more bone surgery and have a certain comfort level with that. What is the gold standard for bone grafting? Autogenous bone … right? So when you have a nonunion such as a failed arthrodesis, would you rather obtain an autogenous bone graft or use bone croutons from a jar? Obviously, there is no comparison.
When I am dealing with a tendon rupture with a sizeable defect that I cannot primarily repair, my first thought is: how can I get real tendon to bride the gap? I am not thinking about man-made or xenograft implants. I think those products may be OK for augmentation or making your primary repair more robust. Unlike bone, tendon tissue is avascular. Therefore, autogenous tendon grafting is less paramount than autogenous bone grafting.
To that end, I will order a fresh cadaver tendon for whatever tendon that I am repairing. I have had to replace an entire Achilles tendon from the gastrocnemius aponeurosis to the calcaneus, a peroneal tendon from the retromalleolar position to the styloid process and tibialis anterior tendons from the ankle joint to the medial cuneiform. Tendon allografts are readily available. Your tissue bank can match the size and gender for you. Moreover, your hospital may have a stock of tendons in their tissue freezer. Orthopedic surgeons use the tibialis anterior tendon for anterior cruciate ligament repairs so most hospitals are familiar with that graft. Remember, you can order whatever tendon you want from a tissue bank.
Just like complicated osseous reconstructions, you do not always know what you will need. So you call your implant vendor and have the kitchen sink available as far as plates, screws, staples, external fixators, etc. My kitchen sink for tendon repair includes a fresh cadaver tendon, Keith needles, plenty of FiberWire suture (Arthrex), soft tissue anchors, a microdebrider (Topaz, Arthrocare) and human pericardium allograft tissue for augmentation if necessary.