Direct Posterior Midline Approach for Treatment of Insertional Achilles Tendonitis

33 Direct Posterior Midline Approach for Treatment of Insertional Achilles Tendonitis

Taggart T. Gauvain and William C. McGarvey

Abstract

Posterior midline approach for the treatment of insertional Achilles tendonitis is a highly reproducible surgical procedure that has good results with long-term follow-up. Patient satisfaction has reached 96% in some studies and most patients report that they would recommend the procedure to family and/or undergo it again if needed. Few complications occur with respect to the soft tissues due to the position of the incision in between two separate angiosomes. Excellent visualization and access is provided for the Achilles tendon debridement. Up to 70% of the tendon insertion can be safely elevated without increased risk of delayed rupture. This provides for adequate debridement and re-establishment of native resting tone following repair. This approach provides direct access for flexor hallucis longus tendon transfer if indicated. Haglund’s deformity can be adequately resected to decompress the posterior heel with this approach. Double row suture bridge repair provides large surface area of tendon–bone interface allowing for rapid healing and early mobilization in most cases.

Keywords: insertional Achilles tendonitis, Haglund’s deformity, Fowler–Philip angle, Pavlov’s parallel pitch lines, intratendinous spur, nonoperative treatment, surgical approach

33.1 Indications and Pathology

• Degenerative process at the insertion of the Achilles tendon onto the posterior calcaneus.

• Painful condition commonly seen as a chronic overuse issue. It is also seen in sedentary patients as a degenerative process.

• Painful inflammation and degeneration occurs both at the tendon insertion and within the local substance of the Achilles tendon.

• Patients present with heel pain that is exacerbated by mechanical irritation from closed shoe wear, presence of bony impingement, and local bursitis causing inflammation.

• This condition represents 10 to 20% of all Achilles pathology.

• Ten percent of patients are recalcitrant to nonsurgical intervention.¹

• The posterior midline approach for debridement and repair of the insertion of the Achilles tendon is a successful and reproducible means to treat this condition.

33.1.1 Anatomy

• The Achilles tendon (confluence of the gastrocnemius and soleus tendons) is the largest tendon in the body. It connects the triceps surae (two heads of the gastrocnemius and the soleus muscle) to the calcaneus bone in the foot.

• Its primary function is to plantarflex the foot.

• The tendon bears up to 10 times the body weight during single leg stance while running.

• It inserts broadly on the posterior calcaneus covering the entirety of the distal tuberosity and extends to the medial and lateral plantar borders of the bone.

• Anterior to the tendon lies the retrocalcaneal bursa. This bursa can become a source of inflammation and pain especially when a large Haglund’s deformity is present (superolateral calcaneal prominence).

• Deep to the retrocalcaneal bursa lies the deep posterior compartment of the leg encased in its fascial layer. Structures within the deep posterior compartment include flexor hallucis longus (FHL), the posterior tibial artery and vein, the tibial nerve, and flexor digitorum longus. These structures lie in this order from lateral to medial starting at the medial border of the distal tibia within the deep posterior compartment.

33.1.2 Clinical Evaluation

• Palpation of the tendon insertion often elicits pain, most commonly over the superolateral corner of the calcaneus where a visible prominence may be present.

• Patients often have a contracture of the Achilles tendon and have limited dorsiflexion.

• The intratendinous spur is often painful and palpable on physical exam.

• Thickening and nodularity of the tendon is common.

• Occasionally there will be crepitus or even an actual squeak with motion.

• Shoe wear is mostly limited to backless or soft-heeled types.

33.1.3 Radiographic Evaluation

• Lateral radiographs will often show a large Haglund’s deformity (superolateral calcaneal prominence), ossific changes within the distal portion of the tendon, and traction spur formation at the insertion of the Achilles tendon (Figs. 33.1).

• The Haglund deformity can be diagnosed using radiographic parameters including Fowler–Philip angle, Pavlov’s parallel pitch lines, and calcaneal pitch angle.

A Fowler–Philip angle greater than 75 degrees (normal is 44–69 degrees).²

Posterior bone prominence above the superior parallel pitch line.³

Combined pitch angle and Fowler–Philip angle greater than 90 degrees.

• Magnetic resonance imaging (MRI) is indicated preoperatively in select cases (Fig. 33.2).

Prior Achilles surgery.

Suspicion of infection.

Atypical pain and presentation.

Defining the extent of degenerative tendon in noncalcification tendinopathy.

33.1.4 Nonoperative Options¹^,⁴^–⁶

• Icing regimens.

• Activity modification.

Fig. 33.1 Lateral radiograph demonstrating large posterior calcaneal spur, tuberosity deformity, and Haglund’s deformity.

Fig. 33.2 Sagittal magnetic resonance imaging (MRI) of the heel. Note increased uptake surrounding the distal insertion of the Achilles and the deterioration at the bone-tendon interface. This is a severe case of this disorder.

• Boot immobilization.

• Oral anti-inflammatory medication.

• Physical therapy including eccentric strengthening, iontophoresis, and aggressive Achilles tendon stretching exercises.

• Extracorporeal shock wave therapy.

• Nitroglycerine patches.

• Platelet-rich plasma (PRP) injections.

• Almost 90% of patients will respond well to nonoperative intervention.

33.1.5 Contraindications

• Presence of adjacent scars/incisions that may be utilized to approach the Achilles tendon.

• Posterior skin ulceration or wound.

• Dysvascular extremity.

• Active infection.

• Large, thick callosities.

33.2 Goals of Surgical Procedure

• Goals of the surgery are to remove damaged and diseased tendon tissue, inflamed bursal tissue, bone prominences causing impingement, and painful osteophytes as well as calcified areas in and around the insertion of the Achilles tendon.

• By removing the degenerative and inflamed tissue, the patient may find great relief of pain and the ability to resume desired activities and normal shoe wear.

33.3 Advantages of Surgical Procedure

• The direct posterior midline approach provides direct access to the Achilles tendon and calcaneus. Ninety-five percent of patients have central tendon disease that needs to be removed. Exposure of this area is generous and uncomplicated with good technique.

• The midline incision gives you healthy tissue flaps by not requiring division or disruption of the blood supply to the skin. The incision is in between angiosomes of the posterior leg with the medial flap supplied by the calcaneal branches of the posterior tibial artery and the lateral flap supplied by the calcaneal branches of the peroneal artery.

• The incision also keeps the sural nerve and vein safely in the tissues lateral to the surgical wound. There is almost no loss of sensation following this incision because it is placed at the border of the medial saphenous nerve dermatome and the lateral sural nerve dermatome.

• This approach is indicated for insertional Achilles tendonitis, Achilles tendinosis, posterior compartment access, tibiotalar joint fusion, subtalar joint fusion, and tibiotalocalcaneal fusion.

33.4 Key Principles

• Prone positioning.

• Direct midline approach over the distal Achilles tendon.

• Split the Achilles insertion and remove all tendonotic portions of the tendon.

• Resect the Haglund’s deformity.

• Reattach the Achilles back to the tuberosity with suture anchors.

• FHL tendon transfer augmentation is performed if greater than 50% of the Achilles tendon is debrided.

33.5 Preoperative Preparation and Patient Positioning

• Operative limb is appropriately shaved with an electric clipper in the pre-op holding area.

• General endotracheal anesthesia should be applied with the patient still on the hospital gurney.

• Tourniquet should be placed high on the thigh of the operative limb prior to turning prone.

• The patient is turned prone on the OR (operating room) table with gel rolls supporting the chest and padding for all bony prominences. The arms should be in the “superman” position with the shoulders abducted less than 90 degrees.

• The feet should be hanging just off the edge of the bed with a pillow under the anterior ankles.

• A bump can be placed under the nonoperative side hip to adjust rotation of the operative limb to have the posterior midline ankle facing directly to the ceiling.

33.6 Operative Technique

• A 6-cm incision is made directly in the posterior midline of the heel. Incision starts 2 to 3 cm above the insertion of the Achilles tendon on the calcaneus and ends just distal to the glabrous–nonglabrous skin junction (Fig. 33.3).

• Full-thickness dissection down to the level of the paratenon, which is then incised vertically along the tendon midline.

• Tendon and its insertion are split in the midline with the scalpel the length of the skin incision.

• The tendon insertion is reflected with subperiosteal dissection off the calcaneus medially and laterally, but be sure to leave some far medial and far lateral tendon insertion intact to maintain natural resting tone and tension for the repair later.

• Small Weitlaner self-retainer is then placed within the split portion of the tendon proximally. Be careful not to place any excessive retraction directly on the skin flaps (Fig. 33.4).

• Sharply excise degenerative and calcific portions within the tendon and along the insertion with the scalpel. You can feel these portions of the tendon as lumps and grainy areas along the tendon.

• Deep to the tendon layer is the tissue of the retrocalcaneal bursa. There is fatty tissue and small veins present in this area. This tissue should be removed with the assistance of electrocautery given it is a fairly vascular tissue. You are safe in the midline and superficial to the deep posterior compartment fascial layer (Fig. 33.4).

• Any posterior spur on the calcaneus can be removed with osteotome or oscillating saw.

• The Haglund’s deformity can now be removed using osteotome or oscillating saw. Be sure to angle your cut so that you do not violate the posterior facet of the calcaneus. The goal is to remove the triangular bony prominence and leave a flat surface behind (Fig. 33.5).