Mark E. Easley and Matthew J. DeOrio
DEFINITION
Insertional Achilles tendinopathy is posterior heel pain at the insertion of the Achilles tendon.
The clinical diagnosis is acute and chronic pathology of the Achilles tendon insertion and its surrounding tissues.
ANATOMY
The Achilles tendon, the condensation of the gastrocnemius and soleus tendons, inserts on the posterior calcaneal tuberosity.
The insertion is not only posterior but also on the medial and lateral aspects of the calcaneus.
A dorsal-posterior calcaneal prominence is most obvious on a lateral radiograph. The Achilles tendon inserts distal to this, directly posterior on the calcaneus.
Between the distal Achilles tendon and the dorsal-posterior calcaneal prominence, immediately proximal to the Achilles insertion, is the retrocalcaneal bursa.
A pre-Achilles bursa is superficial to the distal Achilles tendon.
PATHOGENESIS
While not fully understood, repetitive microtrauma to the Achilles tendon insertion is thought to be the cause.
Most likely some initial injury occurs, followed by multiple minor reinjuries that lead to chronic symptoms.
In the acute phase, the process may have some inflammatory characteristics; however, the chronic process is degenerative, with a relative paucity of inflammatory tissue.
Without histologic confirmation, the diagnosis of Achilles tendinitis or tendinosis cannot be made; therefore, the pathologic process at the Achilles tendon insertion is viewed as “tendinopathy” without tissue confirmation.
PATIENT HISTORY AND PHYSICAL FINDINGS
The patient may recall an inciting event but typically reports chronic acitivity-related aching or even sharp pain at the posterior heel.
In addition, the patient notes a progressively enlarging prominence on the posterior heel.
This ache is usually accompanied by exquisite tenderness directly posteriorly on the calcaneus, at the Achilles tendon insertion, with manual pressure, on contact from the shoe’s heel counter, or when the posterior heel is rested on a hard surface.
Putting the Achilles tendon on stretch aggravates the symptoms, such as when the patient walks uphill.
Physical examination reveals the following:
A prominence is evident on the posterior heel, at the Achilles tendon insertion (FIG 1).
Tenderness is felt directly on the posterior calcaneal prominence.
No tenderness is found in the Achilles tendon proximal to its insertion on the calcaneus.
Thompson’s test is negative.
IMAGING AND OTHER DIAGNOSTIC STUDIES
A lateral weight-bearing radiograph of the foot often demonstrates irregularities and calcifications at the Achilles tendon insertion on the posterior calcaneus (FIG 2A).
While unnecessary to make the diagnosis, magnetic resonance imaging (MRI) defines the extent of tendon involvement at the insertion and the presence of retrocalcaneal and perhaps even pre-Achilles bursitis (FIG 2B).
DIFFERENTIAL DIAGNOSIS
Pre-Achilles bursitis
Retrocalcaneal bursitis
Calcaneal stress fracture
Haglund’s deformity (prominent dorsal-posterior calcaneal tuberosity impinging on the Achilles tendon)
Calcaneal stress fracture
Posterior ankle impingement
Plantar fasciitis
Noninsertional Achilles tendinopathy
NONOPERATIVE MANAGEMENT
Activity modification (avoidance of activities that place the Achilles tendon on stretch)
Nonsteroidal anti-inflammatory agents
Heel lift or a shoe with a heel to unload the Achilles tendon
Open-backed shoe or a shoe with a soft heel counter
FIG 1 • Example of posterior calcaneal prominence characteristic of insertional Achilles tendinopathy.
FIG 2 • A. Lateral foot radiograph demonstrating the posterior calcaneal prominence and calcification within the Achilles tendon insertion. B. T2weighted sagittal MRI of patient with insertional Achilles tendinopathy. Signal change in the distal tendon and retrocalcaneal bursitis can be seen.
Physical therapy
Focus on eccentric strengthening exercises
In our experience the common practice of aggressive Achilles stretching must be avoided as it will aggravate the symptoms.
Modalities: ultrasound, iontophoresis
Extracorporal shockwave therapy may have some benefit but is largely unproven.
Corticosteroid injection may lead to Achilles rupture and is contraindicated unless the process is isolated to retrocalcaneal bursitis, in which case a judicious injection of only the retrocalcaneal bursa can be performed.
SURGICAL MANAGEMENT
The primary surgical indication is nonoperative management.
Up to 50% of insertional Achilles tendinopathy can be successfully managed without surgery, even when there is a large posterior calcaneal prominence.
Insertional Achilles teninopathy with central calcific tendinosis may be less amenable to nonoperative management.
Preoperative Planning
Preoperative medical clearance
Even in healthy patients, the thin skin on the posterior heel is at risk. Carefully inspect skin to be sure that the patient is a reasonable candidate for a posterior approach to the Achilles tendon insertion.
With extensive Achilles tendon degeneration (confirmed with preoperative MRI), an augmentation of the insertion may be warranted. Therefore, preoperative planning should include the anticipation that the flexor hallucis longus (FHL) tendon may need to be harvested and transferred to the posterior calcaneus. The FHL tendon lies immediately deep to the deep compartment fascia that is anterior to the Achilles tendon and can readily be harvested through the same approach.
As a rough estimate, we perform an FHL augmentation in less than 10% of cases but routinely have our preferred anchoring system available should the transfer be warranted.
We educate all of our patients undergoing surgical management for insertional Achilles tendinopathy that, based on our intraoperative findings, an FHL tendon transfer may be necessary.
The recovery following surgical management for insertional Achilles tendinopathy is prolonged and may take a full year before the patient returns to full activity. We educate our patients that the recovery is not rapid.
Positioning
The patient is placed prone on the operating table.
We routinely inflate the thigh tourniquet with the patient supine on the stretcher, then flip the patient to the prone position on the operating room table. This facilitates proper tourniquet position and avoids stressing the patient’s lumbar spine, which may be stressed when placing the tourniquet with the patient in the prone position.
The chest and pelvis are well padded.
The brachial plexi and ulnar nerves at the elbows are protected and relaxed.
The genitalia are protected.
TECHNIQUES
APPROACH AND REFLECTION OF THE ACHILLES TENDON INSERTION
A central approach is undertaken, directly over Achilles tendon and posterior calcaneus (TECH FIG 1A).
The scalpel is moved through skin and into central portion of distal Achilles tendon. Deep incision is continued distally, directly to bone.
The goal is to avoid unnecessary delamination of the soft tissues and to elevate full-thickness flaps.
We then elevate medial and lateral slips of Achilles tendon from the calcaneus (TECH FIG 1B,C).
More than half of the Achilles tendon insertion can be elevated without compromising the integrity of the insertion. One study suggests that up to 75% can be released.
We elevate the Achilles tendon until all the diseased portion of tendon can be excised.
Another study suggests that the entire insertion of the Achilles tendon should be routinely elevated and excised to ensure that all diseased tissue is removed. Reattachment is facilitated by a proximal Achilles tendon lengthening that also serves to unload the Achilles tendon.
We do not routinely elevate the entire Achilles tendon, but should one or both of the Achilles tendon slips become detached, we have uniformly been able to reattach the tendon to the calcaneus with a successful outcome.
TECH FIG 1 • A. Central posterior approach. The foot is hanging from the end of the bed. After a full-thickness incision is made through the diseased portion of the tendon, lateral (B) and medial (C) tendon slips are developed.
DÈBRIDEMENT OF THE DISEASED PORTION OF ACHILLES TENDON
The diseased portion of tendon is gradually pared from the Achilles insertion, until only healthy fibers remain (TECH FIG 2A–C).
Healthy Achilles fibers have an organized, longitudinal pattern.
Degenerated Achilles tendon substance is unorganzied and may be likened to crab meat (TECH FIG 2D,E).
Calcific tendinosis may be present, and all calcifications within the residual Achilles tendon must be excised (TECH FIG 2F).
TECH FIG 2 • Débriding the diseased portion of the tendon. A. Medial tendon slip débridements. B,C. Lateral tendon slip débridement. (continued)
TECH FIG 2 • (continued) D, E. Collection of the excised diseased portion of tendon. F. Calcific tendinosis. It is important to débride the calcifications within the residual tendon.
CALCANEAL EXOSTECTOMY
Retractors are used to protect the medial and lateral Achilles tendon slips.
We routinely use a microsagittal saw to perform the exostectomy.
We first define the exit point on the dorsal calcaneus in order to avoid the tendency to take unnecessary calcaneal bone (TECH FIG 3A).
If necessary, a single fluoroscopy spot image may be used to define the trajectory of the saw blade.
As a general rule, it is steeper (more vertical) than anticipated (TECH FIG 3B).
The bony prominence is mobilized with a chisel and removed with a rongeur (TECH FIG 3C,D).
Commonly, the exostectomy must be “touched up” to remove all of the prominence (TECH FIG 3E).
With the Achilles tendon slips still protected, the medial and lateral chamfers are removed (TECH FIG 3F,G).
This helps narrow the heel and reduce the bulk of the residual calcaneus, medial, and lateral prominences that may lead to persistent pressure and impingement experienced by the patient.
While these chamfers are near the medial and lateral insertion points of the Achilles tendon, typically they can be excised without compromising the residual tendon attachment.
TECH FIG 3 • Calcaneal exostectomy. A. Planning the trajectory for the saw blade. B. A microsagittal saw is used to perform the exostectomy. C. A chisel is used to mobilize the excised fragment. (continued)
TECH FIG 3 • (continued) D. A rongeur is used to remove the resected bone. E. Touch-up to ensure an appropriate amount of bone was removed and an adequate “healing” cancellous surface is exposed. Chamfer preparation to decompress the lateral (F) and medial (G) dimensions of the prominent calcaneus.
REATTACHMENT OF RESIDUAL HEALTHY ACHILLES TENDON
Primary Sutures
With only healthy Achilles tendon fibers remaining and the calcaneus decompressed posteriorly, medially, and laterally, the Achilles tendon should be reattached to the calcaneus.
While one study suggested that up to 75% of the tendon attachment can be released without compromising the integrity of the insertion, we routinely reattach the elevated portion of tendon to the exposed cancellous calcaneal surface.
In our opinion, reattachment not only strengthens the repair but also facilitates direct tendon healing to the calcaneus.
We routinely use two or three suture anchors:
One anchor for each tendon slip
Occasionally, an additional anchor to augment the reattachment of both tendon slips
The anchors are positioned relatively symmetrically on the exposed cancellous surface, in a position that will allow for each respective tendon slip to be reapproximated to the calcaneus in a balanced fashion (TECH FIG 4A,B).
The anchors must be strong enough to lift the foot from the bed (TECH FIG 4C–E). If they should fail, we would prefer for them to fail now so we can rectify the problem.
TECH FIG 4 • A. Anchor being started into bone. B. Anchor secured to bone. (continued)
TECH FIG 4 • (continued) C. Testing the stability of the anchor by lifting the limb off the table. The medial suture anchor (D) is placed symmetrically relative to the lateral anchor and secured to bone (E).
Balancing and Securing the Sutures
The anchor sutures are then passed in through their respective tendon slip, also in a balanced manner to ensure that the tendon slips have near equal tension once the sutures are secured (TECH FIG 5A–C).
We routinely check the anticipated tension by pushing the tendon slip to bone while tensioning the sutures after they have been passed through the tendon.
If the tension does not appear to be equal in the two slips, we readjust the position of the sutures.
The sutures must not only be tensioned appropriately in the longitudinal plane but must also be balanced well in the medial-to-lateral plane, so that the two tendon slips may also be reapproximated side to side and reconfigure the physiologic Achilles attachment.
The sutures are then secured (TECH FIG 5D,E). Have the assistant hold the ankle in plantarflexion so that the tendon slips fully contact the calcaneus.
TECH FIG 5 • A. the suture is passed through the tendon. B. Confirming the optimal balance of the tendon slip on the anchor. C. Passing the sutures through the second tendon slip. (continued)
TECH FIG 5 • (continued) D. Lateral tendon slip fully approximated to bone. Note that the ankle is held in plantarflexion to facilitate tendon approximation. E. Medial tendon slip being attached.
Additional Sutures
We have a low threshold to place a third suture anchor to further stabilize both Achilles slips distally on the calcaneus (TECH FIG 6A–C).
Finally, the most distal Achilles fibers are reapproximated to the fascial tissue immediately distal to the calcaneus (TECH FIG 6D,E).
Avoid trapping fat in this portion of the repair as it may lead to fat necrosis.
The two Achilles slips are then reapproximated to one another with an absorbable suture (TECH FIG 6F).
Gently test dorsiflexion. The ankle should typically still reach neutral without compromising the repair. If it does not, however, it is not a problem.
Patients rarely if ever develop equinus contracture.
Once the Achilles tendon insertion is again healthy and asymptomatic, it has been our experience that the gastrocnemius and soleus muscles accommodate.
TECH FIG 6 • A. A third anchor is being placed centrally and distal to the other anchors. B. Securing these sutures to both tendon slips. C. Tightening these sutures to bring distal tendon slips to bone. D–F.Reapproximating the tendon slips to the distal fascia. D. Passing suture. E. Fully closing the gap between the distal tendon and the fascia. (continued)
TECH FIG 6 • (continued) F. Reapproximating two tendon slips proximal to the reattachment.
CLOSURE
Close the paratenon (TECH FIG 7A).
Reapproximate the subcutaneous tissues (TECH FIG 7B).
Perform a tensionless closure. We routinely use staples in the proximal wound but favor suture in the distal wound, where the skin does not evert as readily (TECH FIG 7C).
Sterile dressings, abundant padding, and a posterior splint with the ankle in its resting tension complete the closure.
TECH FIG 7 • Closure. A. Paratenon. B. Subcutaneous tissue. C. Skin (sutures are used distally to ensure that skin margins did not invert).
FLEXOR HALLUCIS TENDON AUGMENTATION
Only rare patients present with a combination of insertional and noninsertional Achilles tendinopathy.
Extensive dèbridement of diseased tendon is required (TECH FIG 8A,B).
After fasciotomy of the deep compartment, the FHL tendon is identified, the tibial nerve is protected, and the FHL is harvested from its medial fibrosseous tunnel with the ankle and hallux interphalangeal joint in maximum plantarflexion (TECH FIG 8C).
With this local (short) harvest of the FHL, in contrast to a long harvest from the plantar foot via a separate incision, the tendon length is ample for augmentation of the Achilles reattachment (TECH FIG 8D).
The FHL tendon is anchored via an interference screw in the central calcaneus, within the exposed cancellous surface created after exostectomy (TECH FIG 8E).
A suture goes through the plantar calcaneus to allow optimal tensioning of the FHL tendon (TECH FIG 8F).
Suture anchors for reattachment of the the Achilles slips are balanced on either side of the FHL anchor point (TECH FIG 8G).
TECH FIG 8 • A,B. Extensive débridement that left relatively thin residual Achilles slips. C–F. FHL tendon transfer. C. Short harvest of FHL tendon through same incision. D. Adequate length of FHL using the short harvest (harvest from posterior ankle and foot). E. Determining the optimal position to anchor the FHL (ideally, as posterior as possible to maximize mechanical advantage). F. Interference screw fixation of FHL (note the suture through plantar foot to appropriately tension the FHL). G. Suture anchors are placed symmetrically for reattachment of Achilles slips, without interfering with the FHL anchor point.
POSTOPERATIVE CARE
Weeks 0 to 2: Posterior splint with the ankle in resting tension of plantarflexion
At 2 weeks: Return to clinic for suture removal and casting
Weeks 2 to 5: Short leg, plantarflexed (5 to 10 degrees) weight-bearing cast, with weight bearing permitted but use of an assistive device encouraged
At 5 weeks: Return to clinic for cast removal and transfer to a cam boot
Weeks 5 to 8: Cam walker boot with a 5to 10-degree heel lift; initiate a physical therapy program, with a gradual progression to careful resistance exercises
Weeks 8 to 12: Progression to a regular shoe with a heel lift or an open-back shoe with a slight heel; physical therapy with a progressive eccentric strengthening exercises
Between 3 and 6 months: return to full activities; home program for physical therapy
It may take a full year before patients “can forget about this Achilles tendon.”
Maintain independent basic physical therapy exercises for a lifetime.
OUTCOMES
Most patients undergoing surgical management of insertional Achilles tendinopathy have good to excellent results, albeit without returning to full activity for 6 to 12 months.
However, most studies note that there are patients that do not return to full activity and while they are improved, they are not pain-free.
Johnson et al5 reported a mean improvement in the AOFAS ankle outcomes score from 53 to 89 points for 22 patients at 34 months’ average follow-up.
McGarvey et al9 noted an 82% satisfaction rate in 22 patients at mean follow-up of 33 months. Thirteen of 22 patients were pain-free and and an equal number could return to full acitivities.
COMPLICATIONS
Wound dehiscence
Infection
Avulsion of Achilles tendon from anchors on calcaneus
Persitent pain despite apparent successful procedure
Suture reaction or irriation
REFERENCES
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