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Minimal soft tissue dissection, careful suture placement are keys to limited incision repair of acute midsubstance Achilles tendon rupture
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Acute midsubstance Achilles tendon ruptures, an increasingly common athletic injury in patients 30 years to 50 years old, can result in significant functional limitation and decreased quality of life. The management of these injuries is controversial, with no consensus in the literature regarding the use of surgical treatment or optimal repair technique.
The American Academy of Orthopaedic Surgeons clinical practice guidelines report moderate evidence that nonoperative treatment of Achilles tendon ruptures has lower wound healing complications, but higher rates of re-rupture. In addition, limited incision approaches have been found to have fewer overall complications compared with traditional open repair. A recent meta-analysis comparing open and limited incision Achilles repair techniques furthered this evidence, finding less invasive approaches have a significantly reduced risk of superficial wound infection and greater patient satisfaction compared with open repair. Taken together, these findings have helped stimulate the development of less invasive surgical techniques for acute Achilles tendon repair to optimize the functional benefits of surgery while reducing postoperative complications.
Traditional open Achilles repair uses a 6-cm to 8-cm longitudinal posteromedial incision centered over the rupture site with paratenon dissection and placement of Krackow locking sutures into the proximal and distal tendon stumps with a two-strand end-to-end repair. While biomechanically strong, this repair technique is prone to superficial and deep infection, as well as wound healing problems that may require reoperation. The goal of limited incision Achilles repair techniques is to minimize soft tissue and paratenon dissection, while also obtaining an end-to-end repair by percutaneously inserting sutures into both tendon stumps.
The percutaneous Achilles repair system (PARS, Arthrex, Inc.) is a modern, limited incision repair technique that uses a 2-cm to 3-cm transverse skin incision in combination with a reusable curved metal jig to assist in the passing of non-locking and locking sutures.
Biomechanical results of the PARS technique have shown greater construct strength under cyclic and ultimate loads compared with previously described limited incision techniques. In addition, a recently published series that compared 101 PARS and 169 open Achilles repairs found the PARS group had significantly shorter operative times and a higher number of patients able to return to baseline physical activities by 5 months compared with open repair. Though not statistically significant, the overall PARS complication rate was 5% while the open complication rate was 11%. The PARS group also had no cases of sural neuritis or deep infection requiring reoperation. Overall, limited incision Achilles repair can help provide improved wound healing and faster recovery along with lower postoperative complications compared with traditional open repair.
Proper preparations
Prior to surgery, it is important to perform a thorough history and physical exam to determine the timing of the injury and ensure that an acute Achilles midsubstance rupture is present. Physical exam should include a Thompson test, palpation of a gap within the tendon and evaluation of resting ankle dorsiflexion in the affected extremity in the prone position with the knees bent. Preoperative lateral radiograph should be analyzed for the presence a bony avulsion fragment indicative of insertional avulsion injury or midsubstance calcium deposition reflecting chronic Achilles tendinosis, as both of these conditions would change surgical management.
Images: Hsu AR
MRI is not recommended with acute midsubstance ruptures, but may be helpful in the case of chronic ruptures or more proximal tears of the musculotendinous junction. Baseline activity level and risk factors should be noted, in particular diabetes, vascular disease and a history of tobacco use.
Limited incision repair is ideally performed within 2 weeks of the injury to ensure both tendon ends are easy to identify, mobilize and repair. An open repair is generally recommended for midsubstance ruptures older than 4 weeks and cases of insertional rupture and Achilles tendinopathy. Meticulous attention to limited soft tissue dissection, suture placement and management, and postoperative rehabilitation are the keys to obtaining a successful outcome with limited incision repair.
Set-up and approach
In the OR, a thigh tourniquet is placed on the operative extremity prior to flipping the patient. Patients are positioned prone with chest rolls and kneepads with the arms at less than 90° of abduction. The foot of the operative extremity is placed slightly hanging off the end of the bed with a small bump underneath in order to adjust the amount of plantar flexion as needed. After prepping and draping, the extremity is exsanguinated and the tourniquet inflated. The defect within the Achilles tendon is palpated and a 2-cm to 3-cm transverse incision is marked out over the defect in the center of the Achilles tendon (Figure 1). The transverse incision follows the natural skin creases in the back of the ankle and permits easier PARS jig insertion with minimal paratenon disruption.
The skin and soft tissues are incised and dissection is carefully carried down to the rupture site with minimal manipulation of the skin. A transverse incision is made through the paratenon and typically a hematoma is expressed. An index finger can be placed within the wound to confirm the center of the rupture has been located. Carefully inspect the lateral aspect of the incision and retract the sural nerve as the paratenon is opened more laterally and medially. Preservation of the paratenon is important to reduce disruption to the native vascular supply of the tendon. Next, an Allis clamp is inserted and the proximal tendon stump is grabbed securely and pulled through the wound approximately 1 cm to 2 cm. Blunt finger dissection can be used around the proximal tendon stump to free up any adhesions that may limit tendon excursion.
Proximal jig insertion
Prior to inserting the PARS jig, test the center turn wheel first to ensure the prongs of the jig open smoothly and familiarize yourself with the proper direction to open and close the prongs. While continuing to gently pull the proximal stump through the wound, carefully insert the curved jig over the tendon and slide it proximally while slowly opening the prongs. Slide the jig back and forth a few times to ensure you are within the paratenon sheath. There should be little resistance during jig insertion once in the correct location. Palpate the proximal tendon under the skin to ensure the tendon is centered within the prongs of the jig.
A common error is to insert the jig too deep, which will cause subsequent needles and sutures to miss the tendon and pull through. Once the jig is in the appropriate location, it is important to keep the jig centered and stabilized so that it does not veer medially or laterally. Maintaining the jig in a centralized position can help prevent incorrect suture passing and avoid iatrogenic injury to the sural nerve.
For suture passing, begin with all needles unloaded without suture. Insert the first and second needles into their respective holes and through the tendon (Figure 2). Ensure the needles pass through the opposite side of the jig rather than above or below it. It is helpful to have two needles within the tendon at all times during suture passing to stabilize the jig relative to the tendon and avoid piercing an adjacent suture with a needle. A #2 Fiberwire (Arthrex Inc.) suture (i.e., blue) is passed through the first hole using the needle suture passer and made even in length on both sides. Before passing the second suture (i.e., white), the first needle is inserted in and through the third hole.
The third and fourth sutures (i.e., green stripe) are unique in that one end has a loop and one end has a tail and they are passed in a slightly oblique direction. When passing these sutures, the final result should be one loop and one tail on either side of the tendon. The fifth and final Fiberwire suture (i.e., black-and-white stripe) is passed straight across the tendon similar to the first suture. In large laborers, morbidly obese patients or elite athletes, two additional sutures can be passed through the optional sixth and seventh holes to create an additional locking suture. These sutures resemble the looped and tail ones used for the third and fourth sutures, except these are in a different color.
Jig removal
Carefully remove the jig by applying slow, gentle tension toward yourself while closing the prongs using the center turn wheel. As all of the sutures emerge from the wound, check that both sides of each suture are attached properly through the tendon and that there are no misses or pull-outs. A hemostat can be inserted through the loop of the sutures to help guide them out of the wound.
Grab both sides of the suture and gently pull on the proximal tendon to ensure adequate fixation has been achieved. If any or all of the sutures pull out of the tendon, this indicates the tendon was not centered in the jig during suture passing. In this scenario, remove all sutures and repeat the above jig insertion steps while paying close attention to tendon location within the jig. It is not advisable to extend the incision longitudinally on either end of the transverse incision, as this may lead to wound healing complications after surgery.
If proximal fixation is achieved, untangle all sutures and place them spread apart on the medial and lateral sides in the following order from proximal to distal (if following the above suture-passing order): blue, white, looped green stripe, tail green stripe, black-and-white stripe. Take the white suture on both sides and loop it distally around the two green stripe sutures and the black-and-white suture and then back proximally through the looped end of the green stripe suture. Pull the green stripe tail from each side through the tendon onto the opposite site to create a locking suture.
In the end, there will be two non-locking (i.e., blue, black-and-white stripe) and one locking (i.e., white) suture on either side of the tendon. Pull on each pair of sutures firmly to confirm that they are securely grabbing the proximal tendon. Place a hemostat clamp proximally on each group of three sutures on either side to keep them out of the way during distal suture placement.
Distal jig insertion
For distal jig insertion, repeat the above steps and first grab the distal tendon stump with an Allis clamp and deliver it out of the wound while carefully inserting the jig (Figure 3). With most midsubstance Achilles ruptures, the jig should be inserted as distal as possible to bone at the location of the Achilles insertion to ensure all sutures are passed through the tendon. Suture passing, jig removal and creation of locking sutures follow the same steps as outlined above. Again, it is important to pull on each pair of sutures in the end to ensure distal tendon fixation has been achieved.
Achilles tensioning and closure
The ankle should be placed in maximum plantar flexion during suture tying to obtain a secure end-to-end repair (Figure 4). The tendon will gradually stretch out during postoperative weight-bearing and physical therapy. Begin by tying the suture pair furthest from the rupture site (i.e., blue) then moving to the pair closest to the rupture (black-and-white stripe). When tying the non-locking sutures, it is important to have an assistant hold tension on the opposite side as the suture will continue to slide through the tendon with increasing force applied to each knot. While tying, it is critical to pull out all remaining slack from the sutures before securing them with five to six square knots. After each suture is tied, carefully cut the suture above the knot and away from the other sutures to avoid tangling.
After all sutures are tied, the ankle should remain in a plantar flexed position with improved resting tension. After wound irrigation, check the suture knots to ensure they are tucked in deep and not protruding into the subcutaneous tissue. Fiberwire may cause skin irritation and inflammation and elicit a foreign body reaction when placed in a superficial location close to the skin. Any residual strands of tendon should be sharply debrided and tucked within the wound to allow for adequate paratenon closure. Then, 2-0 Vicryl (Ethicon) sutures are used to close the paratenon followed by closure of subcutaneous tissues with 3-0 Monocryl (Ethicon) sutures.
During closure of the subcutaneous tissues, it is important to check and make sure both sides of tissue adequately oppose each other as either side may become tucked in and buried as the ankle is brought into plantar flexion. Skin is closed with 3-0 nylon sutures followed by placement of a sterile soft dressing and short leg posterior mold non-weight-bearing (NWB) splint with the ankle in resting plantar flexion.
Rehabilitation
Diligent postoperative wound care and physical therapy are essential to obtaining successful outcomes after Achilles repair. Patients are kept in a NWB plantar flexion splint for 2 weeks after surgery. If the incision is healed at that time, sutures are removed and patients are transitioned into a NWB cast for 2 weeks. If there is any concern regarding wound healing, then sutures are maintained for an additional 1 week to 2 weeks. It is important to protect the Achilles repair in resting plantar flexion throughout the first 4 postoperative weeks when it is the most susceptible to potential elongation and re-injury.
From 4 weeks to 8 weeks after surgery, progressive weight-bearing with ankle range of motion (ROM) exercises is initiated in a tall controlled ankle motion (CAM) boot with peel-away heel lifts (approximately 2 cm thick). Each layer of the heel lift is gradually removed as pain allows every 2 days to 3 days with the goal of being full weight-bearing with the foot flat at 6 weeks postoperatively. Physical therapy focusing on ankle ROM and gentle Achilles stretching and strengthening is also started 6 weeks after surgery.
From 8 weeks to 12 weeks postoperatively, patients are transitioned out of the tall CAM boot into normal accommodative shoe wear with full weight-bearing. Activity levels are increased as tolerated with no running or jumping from 12 weeks to 16 weeks with full release to all activities after 16 weeks. Patients should be counseled that full return to baseline athletic activities may take a total of 5 months to 6 months after surgery.
- References:
- Chiodo CP, et al. J Bone Joint Surg Am. 2010;92(14):2466-2468.
- Clanton TO, et al. Am J Sports Med. 2015;doi:10.1177/0363546515587082.
- Hsu AR, et al. Foot Ankle Int. 2015;doi:10.1177/1071100715589632.
- Khan RJ, et al. Cochrane Database Syst Rev. 2010; doi:10.1002/14651858.CD003674.pub4.
- McMahon SE, et al. Foot Ankle Surg. 2011;doi:10.1016/j.fas.2010.11.001.
- Nilsson-Helander K, et al. Am J Sports Med. 2010;doi:10.1177/0363546510376052.
- For more information:
- Andrew R. Hsu, MD, can be reached at 101 The City Dr. South, Pavilion 3, Orange, CA 92868; email: hsuar@uci.edu.
Disclosure: Hsu reports no relevant financial disclosures.