Operative Techniques in Orthopaedic Surgery (4 Volume Set) 1st Edition

512. Mini-Open Achilles Tendon Repair: Perspective 2

Mark E. Easley, Marc Merian-Genast, and Mathieu Assal

DEFINITION

images Achilles tendon ruptures usually occur 3 to 4 cm above the calcaneal tuberosity.

images Although most injuries are “complete” ruptures, “partial” injuries have been described.

images 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

images The Achilles tendon is about 9 cm long and 0.9 cm in diameter.

images The proximal part is composed of the gastrocnemius and soleus tendons.

images The distal portion inserts onto the posterior aspect of the tuberosity of the calcaneus.

images The Achilles tendon is surrounded by the paratenon, a delicate envelope that contributes to tendon vascularization.

images There is an area of poor vascularity located between 2.5 cm and 5 cm above the calcaneal tuberosity.

PATHOGENESIS

images Rupture of the Achilles tendon is a common injury among high-level athletes, recreational sports enthusiasts, or even sedentary individuals.

images Rupture of the Achilles tendon usually occurs during forceful dorsiflexion of the ankle.

images Patients often describe hearing or feeling a “pop” in the back of their ankle.

images Intratendinous degeneration can be found histologically.

images Association with cortisone and fluoroquinolone use has been demonstrated.

images This is typically a middle-age lesion, with peak incidence during the third and fourth decades.

NATURAL HISTORY

images There is a great amount of controversy concerning the treatment of an acute rupture of the Achilles tendon.

images 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.

images The major factor motivating surgeons to use a nonoperative approach appears to be avoiding the wound complications that occur with an operative repair.

images An increasing number of reports in the literature have tended to favor operative treatment of an acute rupture of the Achilles tendon.

images The exact type of operative procedure and the postoperative regimen remain controversial.

images If soft tissue complications are avoided, excellent functional results and full return to previous activity can be expected.

PATIENT HISTORY AND PHYSICAL FINDINGS

images Physical examination reveals moderate swelling about the posterior aspect of the ankle.

images Patients are usually able to walk, although with moderate pain.

images With the patient prone, spontaneous excess dorsiflexion of the involved ankle is noted.

images 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.

images The Thompson squeeze test is positive.

images Patients have difficulty walking on their toes or rising up on their heels.

IMAGING AND OTHER DIAGNOSTIC STUDIES

images History and physical examination are sufficient to confirm the diagnosis.

images Since these injuries occur in a traumatic setting, plain radiographs of the ankle are strongly advised.

images There have been many reports of associated ankle fractures (medial malleolus).

images Calcaneal (tuberosity) avulsion will appear on the lateral view.

images 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

images Ankle sprain

images Ankle fracture

images Tennis leg (gastrocnemius tear)

images Acute paratenonitis

images Calcaneal (tuberosity) avulsion

images Plantaris tendon rupture

NONOPERATIVE MANAGEMENT

images Nonoperative treatment of acute Achilles tendon ruptures involves prolonged immobilization.

images Prolonged immobilization is associated with musculoskeletal changes (atrophy), increased time necessary for rehabilitation, and delayed return to work and preinjury activities.

images In randomized studies the rerupture rate has been found to be much higher in the nonoperative group.

images However, nonoperative treatment avoids surgical complications.

images 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

images Plain films should be reviewed for fracture, avulsion, and calcific tendinopathy.

images All imaging studies are reviewed.

images Examination under anesthesia should be performed before positioning the patient to reconfirm the side of injury.

Preoperative Planning

images 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.

images 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

images The patient is placed in the prone position.

images The patient's brachial plexi and ulnar nerves at the elbow are well protected from tension and untoward pressure, respectively.

images The patient's genitalia must be protected.

images 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.

images This facilitates effective tourniquet placement and avoids hyperextension of the back during tourniquet placement with the patient already prone.

images The feet are suspended over the end of the bed, with firm padding under the ankles.

images 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

images Mini-open incision (TECH FIG 1A)

images Make a longitudinal skin incision about 2 cm long at the level of the rupture.

images The incision is longitudinal in the event the procedure has to be converted to a full open procedure.

images Divide the paratenon to gain control of the ruptured tendon ends (TECH FIG 1B).

images The plantaris tendon may occasionally be intact despite complete Achilles tendon rupture (TECH FIG 1C).

images Tag the two tendon ends with suture (TECH FIG 1D,E).

images

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

images Using the proximal tag sutures, apply tension to the proximal tendon stump.

images Place retractors within the paratenon to define the interval between the tendon and the paratenon.

images Advance the Achillon device within the paratenon on the medial and lateral aspects of the tensioned proximal tendon (TECH FIG 2A,B).

images Typically, the tendon is palpable between the arms of the Achillon device.

images In succession from closest to farthest from the rupture, pass three sutures through the tensioned proximal tendon (TECH FIG 2CF).

images 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).

images 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).

images 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.

images

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.

images

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

images This is essentially the mirror image of placing sutures in the proximal tendon.

images 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.

images Advance the Achillon device's inner arms on either side of the Achilles tendon, within the paratenon (TECH FIG 4A).

images Palpate to be sure that the tendon is indeed between the two arms of the Achillon device.

images 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 4BE).

images 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).

images To ensure that the purchase of the sutures in the distal tendon is satisfactory, apply forceful tension to the sutures.

images Tension should plantarflex the ankle (TECH FIG 4G).

images 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.

images

images

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

images Approximate the two tendon ends by tensioning the sutures (TECH FIG 5A).

images The sutures must be carefully organized so that corresponding sutures are secured to one another.

images 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.

images Secure the two sets of sutures closest to the rupture to one another first.

images With tenson maintained on one side, secure the other side with a surgeon's knot (TECH FIG 5B).

images Then secure the other side, applying tension first to remove residual slack in the suture (TECH FIG 5C).

images Repeat the suture technique described for the initial set of sutures for the other sets (TECH FIG 5D).

images Secure the intermediate set of sutures to one another, followed by the sets farthest from the rupture.

images 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.

images 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).

images Setting the resting tension of the repair slightly greater than that of the contralateral extremity is acceptable and, in our opinion, preferred.

images Avoid undertensioning of the repair.

images As for flexor tendon repairs for the hand, we recommend reinforcing the repair with additional sutures directly at the rupture (TECH FIG 5F).

images 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.

images We routinely perform this reinforcement with a running, absorbable suture.

images This not only reinforces the tendon repair but tends to bring more tendon collagen directly to the repair site.

images Place the running or alternatively multiple interrupted sutures circumferentially at the repair site.

images

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

images Repair the paratenon and fascial layer over the tendon to a “water-tight” closure (TECH FIG 6A).

images Reapproximate the subcutaneous layer and skin to a tensionless closure (TECH FIG 6B,C).

images

images

TECH FIG 6  A. The paratenon and fascial layer are reapproximated. B, C. The subcutaneous layer and skin are reapproximated to a tensionless closure.

images

POSTOPERATIVE CARE

images Low-molecular-weight heparin (subcutaneous administration) is used for prophylactic anticoagulation for 3 weeks postoperatively.

images We institute an early functional rehabilitation program, carefully supervised by the physical therapist, which is divided into four distinct stages.

images For the first 2 weeks patients are allowed partial weight bearing (30 to 45 pounds) and maintained in the splint full time.

images Then gentle ankle range of motion (flexion and extension) is begun, as well as thigh muscle exercises and the use of a stationary bicycle.

images The goal is to reach a neutral ankle position by the end of the third week.

images After 3 weeks, full weight bearing is allowed with continuous use of the protective splint.

images At the end of 8 weeks the splint is discontinued and weight bearing is allowed without any external support.

images A more intensive program of ankle range of motion, stretching, and isometric and proprioceptive exercises is instituted.

images Jogging is allowed at 3 months, and more demanding sports at 5 months.

OUTCOMES

images 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.

images 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).

images 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.

images 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.

images 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.



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