Mark E. Easley, Marc Merian-Genast, and Mathieu Assal
DEFINITION
Achilles tendon ruptures usually occur 3 to 4 cm above the calcaneal tuberosity.
Although most injuries are “complete” ruptures, “partial” injuries have been described.
An increasing number of reports in the recent literature favor operative treatment of a fresh rupture of the Achilles tendon; mini-invasive techniques are associated with a lower complication rate.
ANATOMY
The Achilles tendon is about 9 cm long and 0.9 cm in diameter.
The proximal part is composed of the gastrocnemius and soleus tendons.
The distal portion inserts onto the posterior aspect of the tuberosity of the calcaneus.
The Achilles tendon is surrounded by the paratenon, a delicate envelope that contributes to tendon vascularization.
There is an area of poor vascularity located between 2.5 cm and 5 cm above the calcaneal tuberosity.
PATHOGENESIS
Rupture of the Achilles tendon is a common injury among high-level athletes, recreational sports enthusiasts, or even sedentary individuals.
Rupture of the Achilles tendon usually occurs during forceful dorsiflexion of the ankle.
Patients often describe hearing or feeling a “pop” in the back of their ankle.
Intratendinous degeneration can be found histologically.
Association with cortisone and fluoroquinolone use has been demonstrated.
This is typically a middle-age lesion, with peak incidence during the third and fourth decades.
NATURAL HISTORY
There is a great amount of controversy concerning the treatment of an acute rupture of the Achilles tendon.
Conservative treatment is found to have a higher rate of tendon rerupture and loss of strength due to the tendon healing in an elongated position.
The major factor motivating surgeons to use a nonoperative approach appears to be avoiding the wound complications that occur with an operative repair.
An increasing number of reports in the literature have tended to favor operative treatment of an acute rupture of the Achilles tendon.
The exact type of operative procedure and the postoperative regimen remain controversial.
If soft tissue complications are avoided, excellent functional results and full return to previous activity can be expected.
PATIENT HISTORY AND PHYSICAL FINDINGS
Physical examination reveals moderate swelling about the posterior aspect of the ankle.
Patients are usually able to walk, although with moderate pain.
With the patient prone, spontaneous excess dorsiflexion of the involved ankle is noted.
In most cases a tender defect (“soft spot”) can be palpated in the Achilles tendon between 2.5 and 5 cm proximal to its insertion into the calcaneal tuberosity.
The Thompson squeeze test is positive.
Patients have difficulty walking on their toes or rising up on their heels.
IMAGING AND OTHER DIAGNOSTIC STUDIES
History and physical examination are sufficient to confirm the diagnosis.
Since these injuries occur in a traumatic setting, plain radiographs of the ankle are strongly advised.
There have been many reports of associated ankle fractures (medial malleolus).
Calcaneal (tuberosity) avulsion will appear on the lateral view.
Ultrasound and MRI are not required for the diagnosis of Achilles tendon rupture but may be of value when the diagnosis is questionable.
DIFFERENTIAL DIAGNOSIS
Ankle sprain
Ankle fracture
Tennis leg (gastrocnemius tear)
Acute paratenonitis
Calcaneal (tuberosity) avulsion
Plantaris tendon rupture
NONOPERATIVE MANAGEMENT
Nonoperative treatment of acute Achilles tendon ruptures involves prolonged immobilization.
Prolonged immobilization is associated with musculoskeletal changes (atrophy), increased time necessary for rehabilitation, and delayed return to work and preinjury activities.
In randomized studies the rerupture rate has been found to be much higher in the nonoperative group.
However, nonoperative treatment avoids surgical complications.
Nonoperative treatment should be considered in elderly patients with limited functional expectations, patients with significant tobacco/alcohol addictions, patients under chronic cortisone treatment, patients with vascular disease, and patients with severe comorbidities (eg, renal failure).
SURGICAL MANAGEMENT
Preoperative Planning
Plain films should be reviewed for fracture, avulsion, and calcific tendinopathy.
All imaging studies are reviewed.
Examination under anesthesia should be performed before positioning the patient to reconfirm the side of injury.
Preoperative Planning
The surgeon should have available the Achillon® (Integra Life Sciences, Plainsboro, NJ) Achilles tendon repair system and two sets each of no. 2 nonabsorbable suture.
The surgeon should be prepared to convert to an open procedure should the mini-open procedure not be feasible (severe shear injury pattern to the tendon).
Positioning
The patient is placed in the prone position.
The patient's brachial plexi and ulnar nerves at the elbow are well protected from tension and untoward pressure, respectively.
The patient's genitalia must be protected.
We routinely use a thigh tourniquet applied with the patient still supine on the stretcher before placing the patient in the prone position on the operating table.
This facilitates effective tourniquet placement and avoids hyperextension of the back during tourniquet placement with the patient already prone.
The feet are suspended over the end of the bed, with firm padding under the ankles.
Both lower extremities are prepared into the operative field to determine the appropriate tension of the repair.
TECHNIQUES
APPROACH AND IDENTIFICATION OF RUPTURED TENDON ENDS
Mini-open incision (TECH FIG 1A)
Make a longitudinal skin incision about 2 cm long at the level of the rupture.
The incision is longitudinal in the event the procedure has to be converted to a full open procedure.
Divide the paratenon to gain control of the ruptured tendon ends (TECH FIG 1B).
The plantaris tendon may occasionally be intact despite complete Achilles tendon rupture (TECH FIG 1C).
Tag the two tendon ends with suture (TECH FIG 1D,E).
TECH FIG 1 • A. Mini-open longitudinal incision directly over tendon rupture. B. Paratenon is divided to gain access to tendon ends. C. The plantaris tendon may remain intact despite complete Achilles tendon rupture. D.Tag sutures are placed on the mobilized tendon ends. E. Tension is applied to tag sutures, approximating the tendon ends.
PLACING PERMANENT SUTURES IN PROXIMAL ASPECT OF THE RUPTURED TENDON
Using the proximal tag sutures, apply tension to the proximal tendon stump.
Place retractors within the paratenon to define the interval between the tendon and the paratenon.
Advance the Achillon device within the paratenon on the medial and lateral aspects of the tensioned proximal tendon (TECH FIG 2A,B).
Typically, the tendon is palpable between the arms of the Achillon device.
In succession from closest to farthest from the rupture, pass three sutures through the tensioned proximal tendon (TECH FIG 2C–F).
By retracting the Achillon device distally back into the wound, secure the sutures in the tendon, within the paratenon, and exiting within the wound (TECH FIG 3A,B).
Tension must be placed on the sutures before proceeding to the next step to ensure the sutures are properly anchored in the proximal tendon (TECH FIG 3C).
If the sutures pull out, repeat the three aforementioned steps, with careful palpation to be sure that the tendon is indeed between the arms of the Achillon device.
TECH FIG 2 • A. The Achillon device is advanced within the paratenon. B. Longitudinal tension placed on the tag suture while advancing the Achillon device facilitates optimal positioning of the tendon between the two arms of the Achillon device. C. The suture closest to the rupture is inserted first. Tension is maintained on the tag suture. D. The second suture is passed through the tendon. E. The third suture is passed. Tension is still maintained on the tag suture, and the tendon is centered between the two arms of the Achillon device that are within the paratenon. F. All three sutures are passed through the proximal tendon and organized.
TECH FIG 3 • A, B. By retracting the device from the wound, the three sets of sutures remain in the tendon, are within the paratenon, and exit at the wound. C. Longitudinal traction is placed on the sutures to ensure that they are secure within the proximal tendon.
PLACING PERMANENT SUTURES IN DISTAL ASPECT OF THE RUPTURED TENDON
This is essentially the mirror image of placing sutures in the proximal tendon.
With distal ruptures, the Achillon device must be advanced as close to the Achilles insertion on the calcaneus as possible to optimize the sutures' purchase in tendon.
Advance the Achillon device's inner arms on either side of the Achilles tendon, within the paratenon (TECH FIG 4A).
Palpate to be sure that the tendon is indeed between the two arms of the Achillon device.
Place the three sutures (similar to those in the proximal tendon), from closest to farthest from the rupture, into the distal tendon, with tension applied to the tag sutures (TECH FIG 4B–E).
Retract the Achillon device from the wound, thereby bringing the three sutures within the paratenon and into the wound, ready for repairing the rupture (TECH FIG 4F).
To ensure that the purchase of the sutures in the distal tendon is satisfactory, apply forceful tension to the sutures.
Tension should plantarflex the ankle (TECH FIG 4G).
Should the sutures pull out, repeat the steps described above so that acceptable purchase of the sutures in the distal tendon is achieved. In our opinion, palpation of the tendon between the arms of the Achillon device is helpful.
TECH FIG 4 • A. The Achillon device is advanced within the paratenon on the medial and lateral aspects of the distal tendon. B–E. The three sutures are placed in the distal tendon and organized. F. The Achillon device is retracted from the wound so that the three sutures remain within the tendon, are within the paratenon, and exit at the wound. G. Longitudinal traction ensures that the sutures are secure within the distal tendon. Note the plantarflexion of the ankle with tension on the sutures.
TENDON REPAIR
Approximate the two tendon ends by tensioning the sutures (TECH FIG 5A).
The sutures must be carefully organized so that corresponding sutures are secured to one another.
Passive plantarflexion of the ankle with a bump placed under the dorsum of the foot or maintained by an assistant takes tension off the tendon during repair.
Secure the two sets of sutures closest to the rupture to one another first.
With tenson maintained on one side, secure the other side with a surgeon's knot (TECH FIG 5B).
Then secure the other side, applying tension first to remove residual slack in the suture (TECH FIG 5C).
Repeat the suture technique described for the initial set of sutures for the other sets (TECH FIG 5D).
Secure the intermediate set of sutures to one another, followed by the sets farthest from the rupture.
If the sutures more distant from the rupture are overtensioned during the repair, then the tension gained with the previously secured sutures is forfeited. Therefore, overtensioning of each successive set of sutures is unnecessary.
With the opposite, uninjured extremity prepared into the operative field, the resting tension of the repair may be compared to what is deemed physiologic (TECH FIG 5E).
Setting the resting tension of the repair slightly greater than that of the contralateral extremity is acceptable and, in our opinion, preferred.
Avoid undertensioning of the repair.
As for flexor tendon repairs for the hand, we recommend reinforcing the repair with additional sutures directly at the rupture (TECH FIG 5F).
In our opinion, this is important because the miniopen technique described above only serves the function of an internal splint. When the repair site is directly palpated after repair with only the three sets of sutures, invariably there is mostly suture at the repair site and relatively little collagen.
We routinely perform this reinforcement with a running, absorbable suture.
This not only reinforces the tendon repair but tends to bring more tendon collagen directly to the repair site.
Place the running or alternatively multiple interrupted sutures circumferentially at the repair site.
TECH FIG 5 • A. The ruptured tendon ends are approximated by tensioning both sets of sutures. B. One side of the corresponding sutures closest to the rupture is tied. Tension should be maintained on the other side of this set of sutures. C. After removing slack in the suture, the other side of this first set of sutures is tied. D. The second and third set of sutures are secured. Overtensioning of each successive set of sutures should be avoided since this will cause the previous set to lose its tension. E. The resting tension of the repair should match that of the other uninjured extremity. Preferably, the tension should be slightly greater in the repair. F. The repair is reinforced with a single running or multiple interrupted sutures directly at the rupture.
CLOSURE
Repair the paratenon and fascial layer over the tendon to a “water-tight” closure (TECH FIG 6A).
Reapproximate the subcutaneous layer and skin to a tensionless closure (TECH FIG 6B,C).
TECH FIG 6 • A. The paratenon and fascial layer are reapproximated. B, C. The subcutaneous layer and skin are reapproximated to a tensionless closure.
POSTOPERATIVE CARE
Low-molecular-weight heparin (subcutaneous administration) is used for prophylactic anticoagulation for 3 weeks postoperatively.
We institute an early functional rehabilitation program, carefully supervised by the physical therapist, which is divided into four distinct stages.
For the first 2 weeks patients are allowed partial weight bearing (30 to 45 pounds) and maintained in the splint full time.
Then gentle ankle range of motion (flexion and extension) is begun, as well as thigh muscle exercises and the use of a stationary bicycle.
The goal is to reach a neutral ankle position by the end of the third week.
After 3 weeks, full weight bearing is allowed with continuous use of the protective splint.
At the end of 8 weeks the splint is discontinued and weight bearing is allowed without any external support.
A more intensive program of ankle range of motion, stretching, and isometric and proprioceptive exercises is instituted.
Jogging is allowed at 3 months, and more demanding sports at 5 months.
OUTCOMES
This limited open procedure with use of the Achillon instrument provides the advantage of an open repair but avoids the soft tissue problems associated with open repair.
Assal et al published a prospective multicenter study1 including 82 patients. Results showed no wound healing problems and no infections. No patient noted a sensory disturbance in the sural nerve distribution. All patients returned to their previous professional or sporting activities. The mean AOFAS score was 96 points (range 85 to 100 points).
Complications occurred in three patients. Two of them were noncompliant and removed the orthosis within the first 3 weeks postoperatively, thus disrupting the repair by a new injury. One patient fell 12 weeks after the surgery and sustained a rerupture. All three new injuries were repaired with an open surgical procedure.
Isokinetic results: The concentric peak torque was performed with the ankle in plantarflexion at 30°/sec and 60°/sec of angular velocity, after correction for dominance. There was no significant difference between the injured and uninvolved sides. The endurance testing at 120°/sec also revealed no difference between sides.
Three recent reports describe similar excellent results using the exact surgical technique and Achillon instrument, thus providing further confirmation of its important role in the repair of acute Achilles tendon ruptures.
REFERENCE
1. Assal M, Jung M, Stern R, et al. Limited open repair of Achilles tendon ruptures: a technique with a new instrument and findings of a prospective multicenter study. J Bone Joint Surg Am 2002;84A:161–170.