Abstract
Disorders of the Achilles include acute rupture, chronic neglected rupture, insertional tendinosis, and noninsertional tendinosis. The goals of surgery are to restore the function of the Achilles while minimizing the risk of infection. For both acute and chronic rupture, minimally invasive techniques have allowed us to achieve these goals. The recognition of a gastrocnemius contracture in the setting of chronic tendinosis has altered our management of these conditions but has not supplanted the need for surgical reconstruction for all cases.
Key Words
Achilles, rupture, tendinosis, gastrocnemius, equinus, chronic, allograft, mini-invasive, minimally invasive
Insertional Achilles Tendinopathy
Insertional Achilles tendinosis is a difficult condition to treat that does not respond well to the nonoperative measures that are effective for noninsertional disease. The most practical difficulty lies in the fact that no treatment will resolve the posterior heel prominence that makes shoe wear difficult and is a primary complaint. Although physical therapy and shockwave treatment have proven effective for noninsertional disease, they are not as effective for insertional disease, and in some cases may make the symptoms worse. Once nonoperative methods for treatment of insertional Achilles tendon disease have failed, the next decision to be made is the type of incision used for the surgical approach. We have found that the most effective incision is a central splitting posterior approach for most patients. A central splitting incision of the posterior Achilles tendon and calcaneus works well, and the entire broad plate of the osteophyte can be removed. Use of this Achilles-splitting incision is advantageous because it allows direct visualization of the disease and ease of dissection of the torn portion of the tendon with removal of the osteophyte. However, this incision is associated with a more prolonged recovery ( Fig. 21.1 ).
In obese patients or in those with compromised posterior skin, a posteromedial incision with the patient in a supine, externally rotated position may be used, and allows for a flexor hallucis longus (FHL) transfer if required. The main difficulty with this approach is that the entire medial aspect of the Achilles must be detached, and placement of the anchors is more difficult secondary to the externally rotated position of the leg ( Fig. 21.2 ).
The operation is performed with use of regional anesthesia and the patient in a prone position. A 4-cm vertical incision is made directly over the tendon extending toward the junction of the plantar heel skin. The incision must be taken inferiorly to remove the enthesophyte. In addition, the inferior extension is needed to use the Achilles Speedbridge (Arthrex, Naples, United States) technique for fixation, which we have found to result in superior fixation, direct tendon-to-bone apposition, and improved outcomes. The incision is deepened through the tendon, which is split longitudinally, and the incision is deepened directly onto bone, even inferiorly. The central portion of the tendon is the location of maximum degeneration, and this area can be exposed either through a vertical ellipse or by splitting the tendon and separating it with a retractor. We prefer to split the tendon and remove all disorganized and thickened tissue. The tendon is carefully elevated from the osteophyte leaving the most medial and lateral attachments to the calcaneus intact, as these edges are typically not associated with the osteophyte. The benefit of this technique is that the tension of the Achilles has not been altered, minimizing the risk of postoperative equinus contracture or elongation of the tendon and resultant weakness. Once the distal aspect of the tendon has been elevated, the enlarged osteophyte is visible, and this is excised with an osteotome. Fluoroscopy must be used to ensure that the most distal aspect of the osteophyte has been removed as this can be difficult to visualize. The dorsal posterior surface of the calcaneus must be smoothed down to remove any potential source of irritation on the anterior aspect of the Achilles tendon insertion. The tendon must be repaired with a running locking suture, and we prefer the use of an absorbable nonbraided No. 0 suture. The midline split of the tendon should be repaired prior to use of the Achilles Speedbridge for distal fixation. In many patients, a concomitant gastrocnemius contracture is present, and this should be corrected at the time of reconstruction. With the patient prone, a small incision is made medial to midline (to avoid direct exposure of the sural nerve) at the level of the musculotendinous junction to lengthen the gastrocnemius. This will relieve the tension on the Achilles insertion and minimize the risk of recurrence.
In general, we prefer to reattach the tendon back to the calcaneus to minimize the risk of rupture, facilitate rehabilitation, and to allow for direct tendon to bone healing minimizing the risk of disorganized scar tissue formation ( Fig. 21.3 ). Although, if in the case less than one-third of the insertion is debrided, reattachment of the tendon may not be necessary. Removal of up to one-third of the central aspect of the tendon does not disrupt its attachment whatsoever, and possibly up to half of the tendon insertion can be detached. The proximal row of suture anchors is placed at the posterosuperior calcaneus placed in the medial one-third and the lateral one-third of the calcaneus. The sutures are then taken from deep to superficial within the respective half of the tendon. The second row of anchors are drilled inferior to the attachment of the Achilles tendon. One suture from the proximal medial and proximal lateral anchor are taken and placed through the eyelet of the distal SwiveLock (Arthrex, Naples, United States) interference screw and fixated under tension. This is repeated to complete the fixation that results in a crisscross suture over the Achilles insertion without any knots. The fixation method allows for a broad area of tendon to bone apposition with minimal hardware/suture prominence ( Fig. 21.4 ; ).
For treatment of many severe forms of degenerative tendinopathy, a significant portion of the tendon must be excised, leaving less than 50% of the native Achilles to reattach. In such cases, transfer of the FHL tendon is required, to supplement the strength and vascularity of the Achilles. In lower-demand patients, excision of the entire distal segment of the Achilles tendon with FHL transfer is a very reliable method to relieve pain. Function for activities of daily living along with walking, elliptical, and low-intensity biking, can be expected after this procedure. However, power will be insufficient for any true athletic activity for isolated FHL transfer, and they will not regain the ability to perform a single-limb heel rise ( Fig. 21.5 ).
The only clinical concern that we have with this condition (whether or not it is related to the use of the central splitting incision) is the prolonged recovery time. Up to 1 year may be required for the patient to recover completely and return to full function. The advantages of the central splitting incision are the direct access to the degenerative disease and the removal of the hypertrophic osteophytes; whether the disease or the approach used is responsible for this delayed return to full, painless activity is unclear.
Careful attention to postoperative care is essential during healing of central splitting and other incisions that are used to expose the distal Achilles tendon. Healing invariably occurs uneventfully provided that the foot is held immobilized to prevent formation of a hypertrophic scar, which could be catastrophic. Given the improved blood flow to the posterior skin at 20 degrees of plantar flexion, we immobilize the ankle in this position for 2 weeks in a splint. Formation of scar directly over the heel will lead to problems with shoe wear. The foot must therefore be immobilized postoperatively until full wound healing has occurred. Rehabilitation of the Achilles tendon is important, requiring strengthening modalities, heel elevation, and orthotic arch support. With the rigid fixation provided by the Speedbridge technique, the patient is allowed to bear weight at 4 weeks in a controlled ankle movement (CAM) walker boot with a 2-inch wedge, and physical therapy is initiated. Progression to a neutral over the course of the next 4 weeks is allowed with further transition to an athletic shoe with a small half-inch heel for a further 4 weeks.
Insertional tendinopathy should be distinguished from Haglund syndrome and retrocalcaneal bursitis. In patients with these latter conditions, the bursitis occurs as a result of enlargement of the dorsal superior lateral aspect of the calcaneus. The dorsolateral tuberosity causes impingement against the lateral insertion of the Achilles tendon, and retrocalcaneal bursitis develops. If the bursitis is refractory to nonoperative treatment, the best approach is through a short dorsolateral incision just anterior to the Achilles tendon ( Fig. 21.6 ). The incision is deepened through subcutaneous tissue, the retrocalcaneal bursa is excised, and the insertion of the Achilles tendon and the enlarged posterolateral bone are exposed. Only a lateral ostectomy is performed; a more medial extension of the ostectomy is unnecessary.
Haglund syndrome is commonly associated with retrocalcaneal bursitis, but the retrocalcaneal bursitis may indeed be present without a lateral bone prominence. The bursa is irritated as a result of impingement between the Achilles tendon and the posterior dorsal surface of the tuberosity, causing the inflammatory change. If surgery is required, the bursa is excised along with any bone prominence as previously described.
Alternative incisions may be used to correct insertional tendinopathy, including an extended J-incision. The advantage of this type of incision is that it gives complete access to the entire insertion of the tendon. We use this incision for more severe diffuse insertional tendinopathy when we do not think that we can access the entire tendon through either a central splitting incision or bilateral incisions. With use of the extended J-incision, the tendon is completely detached from its insertion, the offending bone is debrided, the retrocalcaneal space is denuded, and then the tendon is reattached with a suture anchor ( Fig. 21.7 ). However, difficulty with wound healing and need to create a large subcutaneous flap make this less ideal than a central splitting approach.
In general, the tissue is insufficient in amount or of such poor quality that a simple debridement cannot be performed. The management of these more severe forms, as discussed later in the section on management of noninsertional tendinopathy, consists of resection of the insertion of the Achilles tendon with a reconstruction consisting of either an FHL transfer or an Achilles tendon allograft. These more extensive procedures are distinguished from the simple superolateral exostectomy ( Fig. 21.8 ).
Management of Paratendinitis
Recognized as a separate disorder from the degenerative tendinopathies, paratendinitis is an inflammatory condition, typically occurring in athletes, and usually associated with hyperpronation of the foot in conjunction with a mild gastrocnemius muscle contracture. The usual nonsurgical methods of treatment, including contrast bathing, physical therapy, orthotic arch support, and gastrocnemius muscle stretching, are usually sufficient to alleviate symptoms. If the paratendinitis is persistent, a brisement of the paratenon is performed, beginning with injection of 3 mL of lidocaine. The No. 20 needle is inserted just underneath the paratenon, advanced into the tendon, and then backed off so that it lies indirectly under the paratenon. Injection of the anesthetic not only confirms the diagnosis and the correct location of the needle but also elevates the inflamed, scarred paratenon off the tendon. This technique works well enough that it should be tried before surgery.
The surgical procedure for paratendinitis involves a short incision on the medial aspect of the tendon over a length of 2 cm ( Fig. 21.9 ). The subcutaneous tissue is elevated, and then the paratenon is identified and incised. The paratenon is then elevated off the Achilles tendon and stripped by excising the superficial anterior sheath of the paratenon medially, dorsally, and laterally as one sleeve ( Fig. 21.10 ). The deep ventral surface of the Achilles tendon is left intact, to leave the blood supply undisturbed. The foot should be immobilized for a short period to prevent any hypertrophic scar formation, and then therapy with cross training and modalities used in rehabilitation after boot immobilization can proceed for approximately 3 weeks.
