Management of Acute Achilles Tendon Rupture Using the Krackow and Tendon-Bundle Techniques

Yong YANG,Qipei WEI,Zhongzhe LI,Xingjian HUANG,Bin LI,Feng LI,Liying SUN

ABSTRACT Background Acute Achilles tendon rupture is a severe injury of the lower extremities;however,optimal treatment options are not yet available.This study aimed to investigate the surgical method and clinical effect of the Krackow and tendon-bundle techniques for managing acute Achilles tendon rupture.Methods This retrospective case series study analyzed 17 cases of acute Achilles tendon rupture at the Beijing Jishuitan Hospital from December 2012 to January 2020.There were 16 men and one woman,aged 27-45 years,with an average of 39.6 years.Thirteen patients were injured while playing basketball or badminton,and 4 patients were injured while participating in a football match or other sports.All injuries were repaired using the Krackow and tendon-bundle techniques.Postoperative evaluation indicators included active range of motion during ankle plantar flexion and dorsiflexion,height of single foot heel lifting,Amer-Lindholm Achilles tendon function score,and American Orthopedic Foot and Ankle Society (AOFAS) score.Results The patients were followed-up for 6-45 months (average,18.9 months).There was no re-rupture of the Achilles tendon,wound infection,or sural nerve injury.At the final follow-up,the affected and contralateral sides exhibited plantar flexion of 42.1 ± 4.4 °and 43.8 ± 2.8 °,dorsiflexion of 15.8 ± 2.9 ° and 16.6 ± 2.9 °,respectively,and one foot exhibited a heel lifting height of 7.2 ± 1.0 cm and 7.5 ± 0.9 cm,respectively.There was no significant difference between the affected and contralateral sides (P＞0.05).At the final follow-up,the Amer-Lindholm Achilles tendon function score was excellent in 94.1%(16/17) of the patients and good in 5.9% (1/17) of the patients.The AOFAS scores ranged from 90 to 100,with an average of 96.4 ± 3.7.Conclusion Krackow and tendon-bundle techniques can improve the strength of the suture used for the Achilles tendon repair and ensure good matching for broken ends,and thus it is an effective repair method for closed Achilles tendon injury.

KEY WORDS Achilles tendon;Rupture;Tendon-bundle techniques;Repair

INTRODUCTION

The Achilles tendon is one of the most frequently ruptured tendon.It is often ruptured when individuals participate in a basketball,soccer,or badminton match.Achilles tendon rupture mostly occurs between the ages of 35 and 45 years,predominantly in men.In addition to the strong tension generated by muscle contraction,degenerative changes in the Achilles tendon,poor local blood supply,and the application of hormonal drugs are also important pathological causes of rupture.Treatment options for Achilles tendon rupture include conservative and surgical treatment,and the indications for treatment are still controversial[1-3].Conservative treatment is associated with fewer complications.However,the incidence of Achilles tendon re-rupture is relatively high.Additionally,lengthening of the Achilles tendon and loss of muscle strength can occur[1,4-5].Surgical treatments include conventional surgery and minimally invasive surgery,each with its own advantages.Minimally invasive techniques are mainly divided into percutaneous and small incision suturing[1,3,6-10].The percutaneous Achilles tendon suture technique is less invasive;however,the relatively high incidence of Achilles tendon re-rupture and sural nerve injury following this procedure limits its widespread use[6,11-13].A small incision or limited-incision sutures effectively avoid the aforementioned disadvantages;however,the modalities of suture and strength are limited due to the inevitably inadequate exposure to the Achilles tendon.Conventional surgery involves long incisions;therefore,postoperative incision non-healing,infection,and postoperative ankle joint dysfunction can occur[5-6].However,surgeries involving conventional incisions can adequately expose the Achilles tendon,allowing for the selection of sutures with higher strength.Additionally,careful manipulation during conventional incisional surgery can effectively prevent complications.In this study,we retrospectively analyzed 17 cases of acute Achilles tendon rupture at the Beijing Jishuitan Hospital between December 2012 and January 2020.All injuries were surgically repaired using the Krackow and tendon-bundle techniques.

PATIENTS AND METHODS

General Information

The inclusion criteria were as follows:Ⅰ) closed injury with a complete rupture of the Achilles tendon confirmed by physical examination and imaging examinations;Ⅱ)time patients presented at the hospital following injury＜ 3 weeks.

The exclusion criteria were as follows:Ⅰ) open Achilles tendon rupture or avulsion fracture;Ⅱ) previous history of Achilles tendon injury;Ⅲ) concomitant fractures and damage of the ankle,foot,and other surrounding areas.

A total of 17 patients were included in this study (16 men and one woman).The ages of patients ranged from 27 to 45 years,with an average age of 39.6 ± 5.7 years.Thirteen of the injuries were caused by jumping while playing basketball or badminton,and 4 cases were caused by running while playing soccer or other sports.The time between injury and surgery ranged from 0 to 21 days,with an average of 9.4 days.The clinical manifestations included pain,swelling,limited plantar flexion or reduced plantar flexion strength,interruption of Achilles tendon continuity and depression,positive heel lift test,and Thompson’s sign.The diagnosis could be further clarified using ultrasound and MRI (Fig.1).

Surgical Approach (Figs.1 and 2)

All surgeries were performed by a single surgeon (Y Y).The patient was anesthetized with an epidural block in the prone position,and the affected limb had a tourniquet on the proximal thigh with a pressure of 300 mmHg.

Incision and dissection

A longitudinal incision 12-15 cm in length was made on the posterior median tibial side of the Achilles tendon.The flap at the superficial level of the peritendinous sheath canal of the Achilles tendon was lifted on both sides to reveal the edges of the Achilles tendon.The peritendinous sheath canal was incised longitudinally along the posterior median line and carefully peeled off on both sides to fully expose the severed ends.This revealed an irregular tendon rupture in the shape of a horsetail.

Krackow techniques

The hematoma between the ruptured ends was removed,and the severed ends of the Achilles tendon were moderately trimmed.On one side of the severed end,using a syringe needle,a No.2 Ethibond suture was threaded transversely through the Achilles tendon from 3 to 6 cm from the ruptured end,and continuous locking edge sutures were performed on both sides of the Achilles tendon up to the ruptured end.The other side of the tendon end was treated using the same procedure.After plantar flexion of the ankle joint,the sutures at both ends were knotted at the ruptured end simultaneously,ensuring that the severed ends were in contact.

Tendon-bundle techniques

The ruptured tendon bundles were carefully matched and the tendon bundles were sutured end to end using 4-0 PDS sutures as a unit.An“8”suture was used for inter-bundle suturing to ensure accurate alignment and adequate contact between the disconnected ends of the bundles.

Closure of the peritendinous sheath canal and the incision

Fig.1 Surgical repair of the left Achilles tendon rupture using the Krackow and tendon-bundle techniques. (A) Disruption of the Achilles tendon continuity as observed during MRI.(B) A longitudinal incision 1 cm off the posterior median tibial side of the Achilles tendon.(C) The flap was lifted superficially from the peritendinous sheath canal of the Achilles tendon to both sides to reveal the edges of the Achilles tendon on both sides.(D) A longitudinal incision of the peritendinous sheath canal of the Achilles tendon in the posterior median line revealed Achilles tendon rupture,which appears as horsetail-shaped irregular severed ends.(E) Krackow continuous locking edge sutures were performed on both sides of the Achilles tendon with a No.2 Ethibond suture.(F) A 4-0 PDS suture was used to close the peritendinous sheath of the Achilles tendon.(G) After closing the peritendinous sheath,the taut Achilles tendon was pressed against the posterior tibial border.(H) Suture of the closed incision.(I-J) Active plantar flexion and dorsiflexion of the ankle at the final follow-up.(K) Unipedal standing heel lift.

Fig.2 Surgical repair of acute right Achilles tendon rupture using the Krackow and tendon-bundle techniques. (A) A longitudinal incision 1 cm off the posterior median tibial side of the Achilles tendon.The flap was lifted superficially from the peritendinous sheath canal of the Achilles tendon to both sides to reveal the edges of the Achilles tendon on both sides.(B) A longitudinal incision of the peritendinous sheath canal of the Achilles tendon in the posterior median line,exposing the severed ends of the Achilles tendon.(C) Continuous Krackow locked edge suture was performed on both sides of the Achilles tendon with a No.2 Ethibond suture.(D) End-to-end sutures with 4-0 PDS sutures between the bundles of severed ends.(E) A 4-0 PDS suture was used to close the peritendinous sheath of the Achilles tendon.(F) A postoperative adjustable brace to immobilize the ankle in plantar flexion at 20 °.(G-H) Active plantar flexion and dorsiflexion of the ankle at the final follow-up.(I) Unipedal standing heel lift.

The Achilles tendon was visibly tensed after the repair.While applying gentle pressure on the Achilles tendon,the peritendinous sheath canal was closed with continuous sutures using 4-0 PDS sutures.After suturing the peritendinous sheath,the tensed Achilles tendon was pressed against the dorsal tibia.The subcutaneous and skin sutures were closed layer by layer.

Postoperative Management

Postoperatively,the ankle was fixed in a 20 ° plantar flexion cast or brace,which was adjusted to 10 ° after 3 weeks.Six weeks after surgery,the cast or brace was removed.The ankle brace for walking was fixed,and the patient started to walk under partial weight-bearing.Twelve weeks after surgery,complete weight-bearing and functional exercises for ankle joint resistance and heel lifting were performed.No strenuous exercise was performed for 6 months after the surgery.

Observation Inde xes

The observation indexes included the range of motion of the ankle during plantar flexion and dorsiflexion,the height of heel lift in unipedal standing,postoperative complications,the Amer-Lindholm Achilles tendon score,and the AOFAS ankle-hindfoot score.Postoperative complications included incision infection,non-healing wounds,Achilles tendon re-rupture,heel lift weakness,claudication,and peroneal nerve injury.

Ankle plantar flexion and dorsiflexion mobility were measured with a circumferential goniometer placed on the lateral malleolus and measured with the lateral malleolus as the axis of rotation.The movable arm was aligned with the fifth metatarsal and the fixed arm was aligned with the fibula.The patient was asked to perform active maximum plantar flexion and dorsiflexion of the ankle joint,and the average of three movements was considered for each measurement.For the unipedal standing heel lift height measurement,the patient stood on one foot.The height of the heel from the ground after heel lift was measured three times separately and averaged.

The Amer-Lindholm Achilles tendon score was based on the subjective perception of the Achilles tendon area,walking gait,heel lift strength,muscle strength,calf leg circumference,and ankle mobility.The results were divided into three grades:excellent,good,and poor.The AOFAS ankle-posterior function score included a total of nine items.The score was determined based on scores provided by the patient and from the physician’s examination.The items included indicators of pain,functional and voluntary activity,support,maximum walking distance (measured by blocks),ground walking,abnormal gait,anterior-posterior activity (flexion plus extension),hindfoot activity,ankle-posterior foot stability,and force line of the foot,with a total score of 100.

Statistical Analysis

Statistical analysis was performed using SPSS 17.0.Data were expressed as mean ± standard deviation,and pairedt-test was used for comparison of data before surgery and at the final follow-up.We chose α=0.05 as the significance level.

RESULTS

Postoperative follow-up ranged from 6 to 45 months,with a mean of 18.9 months.All incisions healed by primary intention,and none of the patients experienced postoperative re-rupture,incisional infection,or peroneal nerve injury.At the last follow-up,the plantar flexion of the ankle was 42.1 ± 4.4 ° and 43.8 ± 2.8 °,and the dorsiflexion of the ankle was 15.8 ± 2.9 ° and 16.6 ± 2.9 ° on the affected side and healthy side,respectively.The height of the unilateral heel lift was 7.2 ± 1.0 cm and 7.5 ± 0.9 cm,on the affected side and healthy side,respectively.There was no statistically significant difference between the affected and healthy sides (P＞0.05) (Table 1).At the final follow-up,the Amer-Lindholm Achilles tendon function scores were 94.1% (16/17) and 5.9% (1/17),respectively.The AOFAS ankle-hindfoot function scores ranged from 90 to 100,with a mean of 96.4 ± 3.7 points (Table 1 and Figs.1 and 2).

Table 1 Measurements of active plantar flexion,dorsiflexion,and unipedal heel lift height of the affected and healthy ankles at the last follow-up

DISCUSSION

Treatment options for acute occlusive Achilles tendon rupture include conservative and surgical treatments.Conservative treatment involves immobilization of the affected limb with a cast or brace,limb elevation,and functional exercises.Previous studies have shown that the incidence of Achilles tendon re-rupture with conservative treatment is 9.8%-12.5%,which is significantly higher than the incidence of Achilles tendon re-rupture with surgical treatment,which is 3.7%-5.1%[1,14-16].Further studies have shown that the incidence of Achilles tendon re-rupture was significantly higher in the conservative treatment group than in the surgical group when the distance between the severed ends of the Achilles tendon was greater than 10 mm[17].Therefore,older patients are relatively more suitable for conservative treatment.In contrast,surgical treatment is recommended for young and middle-aged patients with higher motor requirements and for patients with larger spacing between Achilles tendon rupture ends.

In recent years,minimally invasive Achilles tendon repair techniques,such as small incisions and percutaneous sutures,have attracted increasing attention.The incidence of non-healing wounds and infection after minimally invasive surgery is lower than that after conventional incisional surgical approaches;however,there is a risk of peroneal nerve injury and Achilles tendon re-rupture[1,18].With the conventional incisional repair of the Achilles tendon,the severed ends of the Achilles tendon are adequately exposed,a stronger Achilles tendon repair can be made,and gastrocnemius nerve injury can be effectively avoided.

The occurrence of Achilles tendon re-rupture is closely related to the initial strength of the suture used to repair the Achilles tendon and the final strength of the healed tendon.The Krackow and tendon-bundle techniques can adequately address both aspects.Closed Achilles tendon injuries are mostly located 3-5 cm proximal to the termination,and the severed ends are mostly irregularly horsetail-shaped.Biomechanical experiments have confirmed that among the sutures of the Achilles tendon,the strength of the Krackow continuous locking edge suture is the highest among commonly used sutures[19].In this study,the Krackow technique using No.2 Aegis sutures ensured the early strength of the repaired Achilles tendon.The Achilles tendon consists of 20-30 tendon bundles,and after the rupture of the Achilles tendon,the tendon bundles become unequal in length.The repair of the severed ends of the tendon bundles ensures good alignment and long-term healing of the two severed ends[20-21].In our study,the Krackow and tendon-bundle techniques were used.Significant results were achieved,with no re-rupture of the Achilles tendon and no statistical difference in ankle mobility and muscle strength between the affected side and the healthy side at the final follow-up.

The main reason for the non-healing of an incision,the occurrence of partial skin necrosis,and the occurrence of infection in conventional incisional surgical approaches is that after the repair of the Achilles tendon,the taut Achilles tendon causes increased local skin tension and poor blood flow to the flap at the incision site,which may lead to more serious consequences such as the exposure of the Achilles tendon and deep infection.The aforementioned problems can be effectively prevented by rational planning of the surgical incision,non-invasive intraoperative operation,and careful repair of the peritendinous sheath canal tissue of the Achilles tendon.Afterward,the Achilles tendon is pressed toward the posterior tibial edge,which promotes blood flow to the skin around the incision.In addition,the repair of the peritendinous sheath canal also helps to prevent adhesion of the Achilles tendon to the surrounding tissues and preserves as much blood flow to the severed ends of the Achilles tendon as possible,which helps the Achilles tendon to heal.No complications occurred in this study,and all incisions healed successfully by first intention.

CONCLUSION

The use of the Krackow and tendon-bundle techniques for the treatment of acute Achilles tendon injury can improve the suture strength and ensure good alignment of the severed ends of the Achilles tendon.It is an effective repair method for closed Achilles tendon injury.

FUNDING

This study was supported by the Beijing Health System High-level Health Talent Training Plan (grant no.2015-3-036).

ETHICS DECLARATIONS

Ethics Approval and Consent to Participate

This study received ethical approval from the Ethics Committee of Beijing Jishuitan Hospital (ID:202102-02).All participants provided written informed consent before study enrollment.

Consent for Publication

All the authors have consented to the publication of this article.

Competing Interests

The authors declare no conflicts of interest.The authors state that the views expressed in the article are their own and not the official position of the institution or funder.