ISSN 0972-978X 

  About COAA








The Four Strand Cruciate Suture Design –A New Technique For TA Repair

Rajeev Rao, Ashutosh bhosale,  Ramesh M,  Bhupin bakshi, Manjunatha K

Jubilee Mission Medical College, Thrissur, Kerala, India.

Address for Correspondence:  



Introduction -The Achilles tendon is frequently ruptured tendon and accounts for 20% of tendon injuries. More common are its complications relating to skin dehiscence, sloughing and infection due to more operative time and difficult suture technique. Ankle stiffness is common due to conventional equinus cast for immobilization. We present the results a new suture design of Four Strand Cruciate for tendoachilles repair.

Materials and methods – 15 human cadaver tendons were cut in midsubstance and were repaired four strand cruciate technique and 2 other well established designs. The repairs were evaluated for failure force and mode of failure. From January 2004 to December 2004, 19 cases of tendoachilles ruptures were treated with this technique. A below knee pop cast was applied in 5 degrees of equinus for 2 weeks. For next 2 weeks BK cast in neutral was applied. After 4 weeks ankle was mobilized actively.

Results – In four strand cruciate technique, average force to produce 2 mm gap was 1.8 kg and 2.12 kg for repair to fail which was almost double amount of force as compared to other 2 methods. Commonest injury was due to foot trapped in Indian closet followed by sharp instruments and RTA. The average operative time for repair was 30 min. Functional assessment with AOFAS score showed average 87.1 at one year follow up. All the patients had plantarflexion > 40° and dorsiflexion > 10° at 1 year follow up. Only one patient had skin dehiscence and 3 had adhesions. No patient had rerupture or sural nerve injury.

Conclusion –High tensile strength and gap resistance imparted by four strands and cruciate design provided good strength and allowed us to apply neutral cast and ankles were mobilized early. The ease of placement and less time for repair makes it an ideal technique without any re rupture. It is fast, easy and with high tensile strength which allows neutral cast and early mobilization.

J.Orthopaedics 2008;5(3)e14


The tendoachilles injuries are common problem faced by an orthopedic surgeon in clinical practice. As these injuries affect functional outcome of ankle joint movement, the functional recovery after tendon injury has been the point of interest since years. Surgical repair of acute Achilles tendon ruptures is associated with improved calf strength and reduced tendon lengthening, and may have a smaller re-rupture rate than non-operative management. Early motion is recommended following tendon repairs to prevent formation of adhesions. However, there is concern as to whether active rehabilitation of such patients following -open techniques will lead to wound problems or an increased ankle stiffness.

The best management method of acute tendon injuries is controversial and debated. Although many suture techniques are popular like Kessler, Modified Kessler, Bunnell, Savage, Lee, and Tsuge with their peculiarities none of them meet an ideal suture technique criterias. The tensile strength, Gap resistance, Gliding resistance and stiffness are affected by number of core suture strands, core suture design and location of knot.

In this quest of an ideal tendon suture technique Four Strand Cruciate design appears a strong contender in recent literature of McLarneyet al , Akoi et al . The four strand cruciate technique having 4 strands in cruciate design and knot coming away from repair site is better technique than other techniques.

The purpose of this study was to evaluate four strand cruciate design in cadaver tendon repairs and clinical cases of open repair of acute spontaneous Achilles ruptures with four strand cruciate technique

Material and Methods :

In Vitro study
In vitro cadaver study was planned to decide and compare tensile strength, gap resistance of four strand cruciate technique with already established in use suture techniques like Modified Kessler and Strickland

Four strand cruciate


Modified Kesslar

15 human cadaver tendons of average 5 mm width were harvested. These tendons were cut in midsubstance with a sharp instrument. Out of 15 tendons, 5 were sutured with Modified Kessler, 5 with Strickland and 5 with four strand cruciate technique. Musculotendinous end of each tendon was attached to weighing scale. The other end was applied with sustained linear force which was measured on weighing scale.

The sustained linear force was applied till 2 mm gap was produced at repair site and force was measured directly from scale in Kg. This force was continued till repaired site failed and maximum failure force was determined in kg. The mode of failure in each case was noted like pullout of threads or suture breakage.               

In Vivo study

We selected consecutive group of patients with tendo Achilles injury which were repaired with four strand cruciate technique during January 2004 to December 2004.

Acute injuries of tendo Achilles, essentially midsubstance rupture / cut injuries were included. Tendons injuries less than 2 week were repaired by this technique. 

The exclusion criteria’s were patients with wound infection at the time of presentation, associated fractures of underlying bones, patients requiring arterial and nerve repair, patients with psychiatric disorders, head injuries, substance abuse or cognitive deficiency, severe arthritis of joints, crush injuries. Patients with age less than 12 years and more than 75 years were also excluded.   

Post operative protocol

Immobilization was done in position of least tension on repaired tendon. A below knee cast in 5 degrees of equinus for 2 weeks was applied. Later it was changed to neutral BK cast for another 2 weeks. After 4 weeks of immobilization cast was removed and ankle mobilized.

Functional outcome was assessed by range of movement (ROM) and   AOFAS score. Operative time was recorded in all patients. Condition of wound, scar and any complications were documented. Total period required for return to job or change in job was documented. 

Results :

In vitro study

                     Among the 15 cadaver tendons tested 5 each were with Modified Kessler, Strickland and Four strand cruciate techniques. The data was collected in the form of Force to produce 2 mm gap formation at repair site; Maximum failure force and Mode of failure.

(Table 1)


Force to produce 2 mm gap (Kg)

Maximum failure force (Kg)

Modified Kesslar






Four strand cruciate




In Modified Kessler technique, less than 1 kg of mean force produced both 2 mm gap at repair site and failure of repair (Maximum failure force).

 In Strickland method, average 1 kg of force produced failure.

While in four strand cruciate technique, average force to produce 2 mm gap was 1.8 kg and 2.12 kg for repair to fail which was almost double amount of force as compared to other 2 methods.

The average force to produce 2 mm gap and maximum failure force in Modified Kessler and Strickland is almost equal. The paired student’s‘t’ test was used to study the amount of increased force from 2 mm gap formation to maximum failure force. We found that there was no statistical significant increase in force in these 2 groups.

Mod. Kessler – t value = 1.952

                         p value = 0.2662 (p > 0.05)

Strickland -      t value = 1.4142

                        p value = 0.1950 (p > 0.05)

                    But in case of four strand cruciate method, this increase in force between 2 mm gap formation and maximum failure force was 0.3 kg which was statistically significant.

                       t value = 4.003

                       p value = 0.0039 (p < 0.05)

 Among 15 cases, 60% (9/15) repairs failed by pullout of sutures from tendon ends and 40 %( 6/15) failed by breakage of sutures. In four strand cruciate group 80% (4/5) failed by suture breakage while 20% failed by pullout. In other 2 methods, 80% repairs failed by pullout

   (Table 2)  


Pull out

Suture Breakage

Mod. Kessler






Four strand cruciate







In Vivo study
There were 18 patients with lower limb tendon injuries. Total 19 tendoachilles tendons were repaired (1 patient had B/L TA injury). The age distribution of patients was uniform as shown by kolmogorov test
(Table 3)

The ratio of injuries according to occupation was laborers 31.57%, carpenters and sedentary workers as 10.53% each. The other occupations like students, housewives were 47.47%. 36.84% injuries were due to closet injuries (foot slips and traps in Indian closet, repeated attempts to remove foot causes sharp laceration of tendoachilles). Injuries by knife accounted for 26.32% while RTA caused 15.79% injuries. The other modes of injuries like assault, attrition were seen in 21.05% cases.

 (Table 4)


No of Pts.



 30 –40


 40 –50


  > 50






(Table 5)

Seven out of 19 tendoachilles injuries were due to closet injury (36.84%) while it was injured by RTA in 26.31% and by knife in 15.78%.

The sharp cut injuries were seen in 13/19 tendons (68.42%), while 3/19 were frayed (15.79%) and 3 were lacerated (15.79%).All the injuries by knife were sharp while in closet injury 5/7 were sharp (71.43%) and 2/7 were lacerated (28.57%).The 14/19 tendons were right sided (73.68%) while 5/19 were left sided (26.32%).

(Table 6)

The average operative time for tendoachilles repair was 32.81 minutes with S.D. ± 7.52 min. Average operative time for sharply cut tendons was 30 min. S.D. ± 5.77 min while for frayed tendons it was 43.33 min S.D.± 5.77 min. the lacerated tendons required 31.66 minutes with S.D. ± 2.89 minutes. The operative time difference between these groups was statistically not significant.(t = 0.6407, p value = 0.48) 

The plantarflexion movement at ankle > 40° at 3 months was seen in 8/19 cases (42.10%) while planterflexion at 6 months was > 40° in all patients.

At 3 months there were 10 patients with dorsiflexion at ankle < 10° and 9 patients with dorsiflexion > 10°. At 6 months all 19 limbs had dorsiflexion at ankle > 10°.

The average AOFAS score at 3 months was 76.25 with S.D. ± 7.96 and at 6 months was 87.125 with S.D. ± 3.81. The increase in AOFAS score from 3 to 6 months was 11.125

(Table 7)


3 months

6 months

Plantar flexion >40°

8/19 patients


Plantar flexion <40°

11/19 patients


Dorsiflexion >10°

9/19 patients


Dorsiflexion <10°

10/19 patients


AOFAS score avg











In patients with age less than 30 years, average AOFAS score at 3 months was 79.2 which improved to 89.8 at 6 months. In age group of 30 – 40 years AOFAS score improved from 77 to 87.4 while in 40 – 50 years group it improved from 77.25 to 86.5. In patients with age > 50 years score of 76.2 improved to 86.2. Patients with < 30 years age had better AOFAS score at 3 and 6 months than others but improvement in score from 3 to 6 months was same in all age groups (10.8).

(Table 8)

Two patients had superficial infection. In one case it was associated with skin dehiscence and slough. Both the cases responded to oral antibiotic course and dressings. Patient with skin dehiscence had AOFAS score 82 which was less than average.

                     Three patients had adhesions in which 2 were unable to use Indian closet and had below average AOFAS score. Only 1 patient in our series had sural nerve paresthesia.


Since 1970 the management of tendon injuries is revolutionized due to immediate tendon repair and post repair motion protocols. Over these years many new suture designs, methods has been developed to increase strength and gap resistance of tendon repair techniques. They have permitted more aggressive post repair motion protocols and hence the global improvement in results. In spite of all these advances, there is no consensus over the gold standard or an ideal tendon repair technique.

A four strand cruciate design for tendon repair as described by McLarney3 and Strickland seems to be the near ideal suture technique. A review of literature shows lack of comprehensive clinical study in tendoachilles repair with this technique. Hence this study was performed.

In our study, 15 cadaver tendons were repaired by 3 methods viz. 1) Modified Kessler, 2) Strickland and 3) Four Strand Cruciate and the tensile strength of repairs was judged by linear force. For four strand cruciate the force to produce 2 mm gap was average 1.9 kg which was double the force required for other 2 methods. The maximum failure force was also double as compared to other methods. The attributed reasons for high tensile strength of four strand cruciate was 4 number of strand while other methods had only 2 strands. Lotz[i] in an analytical model proved that four strand cruciate has more tensile strength. In repairs with same number of strands, design of core repair determines the strength.

The mode of failure depends on core suture design and whether suture is locking or grasping type. The locking configuration is one in which the transverse component is passed superficial to the longitudinal so that suture passes around a bundle of tendon fiber and usually prevents pullout. In grasping type, the transverse component passes deep to longitudinal one so that suture does not pass around or lock and is more prone for pull out.

In our study, all repairs were grasping type so the expected result was pull out of sutures at maximum failure force. Though 80% (4/5) of modified Kessler and Strickland sutures failed by pull out, surprisingly 80% (4/5 repairs) of Four Strand Cruciate failed by suture breakage. Though a grasping type repair four strand cruciate exhibits strong pull out resistance due to 4 strands and cruciate design.

The locking designs are known for more gliding resistance and adhesions than grasping types.  The location of knot in four strand cruciate is away from the repair site. This helps in decreasing bulk at repair site and assuring perfect apposition of tendon ends.  More over 4 grasping sutures on surface may make this design more prone for adhesions. But in our cadaver study we were not able to measure and compare gliding resistance due to lack of costly devices like Load Transducers.  

In lower limb, tendoachilles were the commonest tendon injured. All the patients had minimum arc of movement from 10° dorsiflexion to 40° platarflexion at ankle. Even the AOFAS score showed good improvement between 3 to 6 months with 6 months score being average 87.125 indicating good functional outcome. These good results in tendoachilles were attributable to immobilization of ankle in neutral position. Even the period of immobilization was reduced to just 4 weeks contrary to 8 weeks. Due to this strong repair we were able to mobilize patients early with active motion protocols. Khan et al[ii] in Cochrane review reported rerupture rate of 2.3% to 5% after tendoachilles repairs while in our series there was no case of rerupture. Even the skin dehiscence was seen only in single case and 2 patients had superficial infection without any functional problem. Overall in tendoachilles repair four strand cruciate was found to be a good technique with sustainable persistent good results without any major complication. 


The purpose of this study was to compare biomechanical properties of Four Strand Cruciate technique with other established techniques and to evaluate clinical results of this technique.

  • Four Strand Cruciate has significant high tensile strength and gap resistance than other two strand techniques which can allow us to use aggressive post repair rehabilitation protocols.

  • The Four Strand Cruciate with its peculiarities causes fewer complications like reruptures and adhesions.

  • The ease of placement and less time for repair with above properties make it near ideal tendon repair technique.

  • There is no significant correlation between tendon ends, operative time and functional outcome of tendons repaired.

  • There are significantly good results in patients less than 30 years with respect to functional outcome irrespective of type of tendons involved.

  • This technique gives confidence to the surgeon to start with aggressive rehabilitation protocols to achieve good functional results.

  • The incidence of complications like reruptures, adhesions, skin dehiscence is very less.

Reference :

1. Maffuli N. Rupture of the Achilles tendon. J Bone Joint Surg 1999;81-A(7):1019-36

2. Cetti R, Christensen SE. Surgical treatment under local anaesthesia of Achilles tendon rupture. Clin Orthop 1983;173:204-208.

3. Cetti R, Christensen SE, Ejsted R, et al. Operative versus nonoperative treatment of Achilles tendon rupture. A prospective randomized trial & review of literature. Am J Sport Med 1993;21:791-799.

4. Savage R. In vitro study of a new method of flexor tendon repair. J Hand Surg [Br] 1985;10:135-141.

5. McLarney E, Hoffman H, Wolfe SW. Biomechanical analyses of the cruciate four strand flexor tendon repair. J Hand Surg[AM] 1999;24:295-301.

6. Akoi M, Manaske PR, Pruitt DL, Kubota H, Larson BJ. Work of flexion after flexor tendon repair with various suture methods. A human cadaveric study. J Hand Surg[Br] 1995;20:310-313.

7. Lotz JC, Hariharan JS, Diao E. Analytical model to predict the strength of tendon repairs.J.Orthop Res.1998;16(4):399-405

8. Khan RK, Fick D, Brammar T. Interventions for treating acute Achilles tendon ruptures. Cochrane Database Syst Rev 2004;3:CD003674.


This is a peer reviewed paper 

Please cite as : Ashutosh bhosale : The Four Strand Cruciate Suture Design –A New Technique For TA Repair

J.Orthopaedics 2008;5(3)e14





Arthrocon 2011

Refresher Course in Hip Arthroplasty

13th March,  2011

At Malabar Palace,
Calicut, Kerala, India

Download Registration Form

For Details
Dr Anwar Marthya,
Ph:+91 9961303044



Powered by



© Copyright of articles belongs to the respective authors unless otherwise specified.Verbatim copying, redistribution and storage of this article permitted provided no restrictions are imposed on the access and a hyperlink to the original article in Journal of Orthopaedics maintained. All opinion stated are exclusively that of the author(s).
Journal of Orthopaedics upholds the policy of Open Access to Scientific literature.