ARTHROSCOPIC RECONSTRUCTION OF THE ANTERIOR CRUCIATE LIGAMENT WITH HAMSTRING TENDONS

RAY A. MOYER, MD, and PAUL A. MARCHETTO, MD

The technique of anterior cruciate ligament reconstruction has evolved from an open procedure with augmentation to an arthroscopic procedure. Details of the harvesting of the hamstring tendons, selection of the intra-articular fixation points, means of tendon fixation, and postoperative rehabilitation are presented. KEY WORDS: reconstruction, hamstrings, semitendinosus, gracilus, anterior cruciate

Reconstruction of the anterior cruciate ligament using the semitendinosus and gracilis tendons has been per- formed at Temple University Hospital for the past 12 years. Initially, the technique was performed open using a single length of the semitendinosus and gracilis ten- dons along with an extra-articular augmentation similar to a Losee procedure. 1 It is now performed arthroscop- ically, using doubled lengths of both the semitendinosus and gracilis tendons. 2 The extra-articular augmentation is only performed on grossly unstable knees.

PROCEDURE

The patient is administered either general or regional an- esthesia and is then examined. The results of ligament stress testing, patella stability, and range of motion are compared with the normal knee and recorded.

Arthroscopic evaluation of the knee is performed to evaluate the extent.of damage to the anterior cruciate ligament, menisci, and chondral surfaces. The anterior cruciate ligament is then debrided. Unrepairable menis- cus tears are resected and repairable tears are sutured. However, the meniscus sutures are not tied until the an- terior cruciate ligament reconstruction is secured.

Arthroscopy is temporarily terminated and the ham- string tendons are harvested. This must be done care- fully to maximize length and to minimize trauma to the tendons. In those patients with minimal subcutaneous fat, the tendons can be readily palpated approximately 3 cm medial to the tibial tuberosity. Heavy individuals have a roll of fat that overlies the pes and obscures the tendons. In these individuals the tibial tuberosity, me- dial tibial metaphyseal flair, and the fatty deposit are

From the Temple University Center for Sports Medicine and Sci- ence, and the Department of Orthopedic Surgery, Temple University Hospital, Philadelphia, PA.

Address reprint requests to Ray A. Moyer, MD, Broad and Tioga Sts, Philadelphia, PA 19140.

Copyright �9 1992 by W. B. Saunders Company 1048-6666/92/0202-0009505.00/0

used as references in placing the skin incision. For cos- mesis, a small incision is preferable, and identifying the precise location of the tendons makes this possible.

The skin incision is made starting at the superior edge of the pes tendons and extending distally approximately 2 in (Fig 1). When retracting to visualize the tendons, care must be taken not to traumatize the skin edges. The skin and subcutaneous tissue are mobilized and the pes expansion is readily visualized. The interval between the gracilis and semitendinosus tendons is identified by pal- pation. A fascial incision is made between the semiten- dinosus and gracilis tendons, and subfascial fat and paratenon are bluntly dissected from the body of the ten- dons. A curved hemostat is placed under the semitendi- nosus, the more distal tendon, and is drawn up into the surgical wound. The knee is then flexed, allowing more tendon to be withdrawn from the proximal thigh. This allows more efficient stripping of the multiple fascial ad- hesions. In virtually all limbs, both the semitendinosus and gracilis tendons have insertional fibers into the over- lying crural fascia. These fascial bands are usually found on the inferior and distal aspect of the tendons (Fig 2). These bands must be divided to mobilize the tendons which allow for maximal tendon length and prevent the premature transection by the tendon stripper. When the semitendinosus is tensioned with distal traction, it is pal- pated in the middle of the posterior aspect of the thigh. The gracilis outline is palpated along the posterior medial aspect of the thigh.

Harvesting the hamstring tendon has been greatly fa- cilitated by using a tendon stripper (Fig 3). In the past a posterior thigh incision was used, which was technically cumbersome and left a very unattractive scar. Present instrumentation has made that incision unnecessary. At- tention to detail when using the tendon stripper is essen- tial to avoid damaging the tendons or premature transec- tion. The stripper is placed around the tendons while they are under constant manual traction. During proxi- mal excursion of the stripper over the tendon, firm trac- tion is maintained and the stripper is held precisely par- allel to the line of the tendon (Fig 4). Resistance is met

Operative Techniques in Orthopaedics, Vol 2, No 2 (April), 1992: pp 99-103 99

Fig 1. Skin incision. Dot- ted lines are skin inci- sion. Solid lines are pal- pated tendon.

Fig 2. Fascial band left knee. Finger around tendon, hemo- stat around band.

when the stripper meets the musculotendinous junction assuming that all fascial bands have been previously transected. The tendon is transected when the stripper courses through the muscle. No angulation of the instru- mentation is necessary. The tendons are harvested indi- vidually and in a similar fashion, usually harvesting the semitendinosus first.

The tendons are now prepared for subsequent fixation. Two things have been done that have substantially im- proved graft strength: the first is doubling of the tendon

strands and the second is suture augmentation of each tendon with two no. 5 Ticron sutures (Ticron, T-56 needle [special order]; Ethicon, Inc, Johnson & Johnson, Somer- ville, NJ). In the past, the tendons were left attached distally and affixed to the femur with two staples over decorticated bone. If the tendons are doubled and left attached at the pes, having sufficient length to span the bone tunnels is a problem. Consequently, the tendons are now used as free grafts. This allows for adjustment of length in both the tibial and femoral tunnels. Four inches is a sufficient length to traverse the bone tunnels. The tendons are debrided of all muscle tissue and doubled over. Two no. 5 Ticron sutures are placed through the entire length of the doubled tendon in a weave or base- ball-stitch pattern. The sutures should provide stress protection of the tendon and reduce tendon abrasion in the bone tunnels. A cinch knot is placed at each end of the tendons (Fig 5). Firm suture fixation is necessary at the tendon ends to allow passage of the tendons through the bone. These sutures are also used to augment the tendon fixation to bone. An alternative for tendon fixa- tion is to incorporate a loop at one end of the doubled tendons (Fig 6). This loop will be used for femoral fixa- tion. The tendons are then passed through sizers to de- termine the diameter of the bone tunnels. They are usu- ally between 8 and 11 mm in diameter (Fig 5).

Arthroscopy is then resumed. The soft-tissue remnant of the anterior cruciate ligament is debrided from the lat- eral femoral condyle. A sufficient notchplasty is per- formed to allow visualization of the posterior lateral notch and to prevent abrasion of the graft. The notch- plasty is routinely performed with the scope in the an- terolateral portal and the instruments in the anteromedial portal. In small knees or in patients with an exuberant fat pad, the anterior part of the notch is more readily acces- sible with the arthroscope in the anteromedial portal and the instruments in an accessory medial portal.

After preparation of the notch, a lateral incision is

100 MOYER AND MARCHETTO

Fig 3. Tendon stripper (OSI; Orthopedic Sys- tems Incorporated, Hay- ward, CA).

Fig 4. Tendon stripper about tendon In preparation fop har- vesting.

Fig 5. Sutured tendons, drill bit, and sizer.

made that extends from the metaphyseal flair of the distal femur proximally for 2 in. The fascial incision is in the superior part of the iliotibial band. The lateralis muscle is mobilized anteriorly, being careful not to rupture the joint capsule.

The guide pins are now placed in the femur and tibia using the Acufex drill guide. (Acufex cannulated drill guide system; Acufex MicroSurgical Inc., Norwood, MA) The pin sight on the femur is 3 to 4 mm anterior to the over-the-top position, between the 12- and 1-o'clock po-

Fig 6. Sutured tendons with loop.

Fig 7. Sutured tendons with strings through bone tunnel in preparation for passage.

RECONSTRUCTION OF ACL WITH HAMSTRING TENDONS 101

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Fig 8. Staple fixation

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Fig 9. Screw and loop fixation to proximal femur.

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sitions in the left knee or between the 11- and.12-o'clock positions in the right knee. Too generous a notchplasty may cause one to lateralize the femoral pin placement; this will be avoided b y using the 12-o'clock reference point. Visual references for the tibial pin are the center of the anteromedial fibers of the anterior cruciate ligament

to proximal femur.

and parallel to the anterior horn of the lateral meniscus. When the knee is placed in full extension, the tibial pin will fall beneath the horizon of the intercondylar notch.

After the guide pins are placed, they are overdrilled with the preselected drill bit. The tibial tunnel is usually drilled first. Careful penetration into the joint is neces- sary to prevent any damage to the posterior cruciate lig- ament. A soft-tissue resector is introduced through the tibial tunnel to remove debris that may contribute to a cyclops lesion prohibiting knee extension. 3 A plug is placed in the tibial tunnel to maintain joint distension. The femoral tunnel is drilled and the bone edges are chamfered with an abrader and curette.

Passage of the tendons through the bone tunnels is done using two no. 5 Ticron sutures that are passed from the femur through the tibia with an arthroscopic grabber. These sutures are tied to the Ticron sutures sewn through the tendons during graft preparation. The tendons are now drawn retrograde through the bone tunnels (Fig 7). A tight fit within the bone tunnels is preferable to encour- age early bone fixation and contribute to tendon stabil- ity. 4

When the loop technique is used, a no. 5 Mersilene tape (Ethicon, Inc, Johnson & Johnson Company, Som- erville, NJ) is passed through the loop and tied to the passing sutures. Traction on the tape forces the loop to form a narrow leading edge, facilitating tendon passage. The Ticron sutures that were incorporated into the graft during graft preparation are also passed through the drilled canals.

The tendons are fixed on the femoral side first. The

102 MOYER AND MARCHETTO

means of fixation vary depend ing on the t endon length and the surgeons preference. If the tendons do not ex- tend beyond the bone tunnel , the tendons are fixed by tying the no. 5 Ticron sutures over a low profile cancel- lous screw with a fiat washer . If the t endons extend be- yond the bone tunnels, they may be fixed proximally with two staples over decort icated bone (Fig 8) or with a cancellous screw and a soft-tissue washer placed th rough the loop in the tendons (Fig 9).

After fixation of the t endons proximally, the knee is cycled, about 20 times, th rough a full range of motion. This is done while maintaining firm traction on the ten- dons distally. This equalizes the tension of the tendons within the bone tunnels. While maintaining traction, the Ticron sutures are now tied to a low-pl'ofile cancellous screw in the proximal tibia. Bicortical fixation is only used if purchase of the cancellous screw is inadequate. After the tendons are fixed both proximally and distally, the knee is again a r throscoped to make sure there is no impingement in full extension at the notch or in flexion along the lateral femoral condyle.

POSTOPERATIVE CARE

Postoperatively the patient is placed in a h inged brace from 0 ~ and 60 ~ A cont inuous passive motion (CPM) machine is used for 6 hours daily. At 1 week, the brace is set be tween 0 ~ and 90 ~ and partial weight bearing is permitted. S t rengthening exercises are started at I week, with quadriceps blocked over the last 45 ~ of extension. Patella mobilization is also per formed. Bike and pool ex- ercises are started at I month . With satisfactory progress in rehabilitation, running may be started at 4 months , but no agility exercises are al lowed for 8 to 9 months . KT- 1000 (MEDmetric, San Diego, CA) measurements are per- formed at 3, 6, 12, and 24 months . Precluding significant injury to the knee, no change iri KT-1000 measurements should occur once full range .of mot ion has been ob- tained.

DISCUSSION

The success of the reconstruct ion of the anterior cruciate ligament has been improved over the last 10 years by a bet ter u n d e r s t a n d i n g of the funct iona l a n a t o m y , 5'6"7 greater efforts in preserving the menisci, s improved fixa- tion, and well-defined rehabili tation programs with early protected motion. 9 The use of extra-articular procedures has gradual ly regressed with greater confidence in graft strength, precision of graft placement , and s t rength of fixation. 1~ Extra-articular p rocedures are still appropr ia te with significant anteromedial laxity and in pat ients with a gross pivot shift.

The choice of autograft material is ei ther a patellar ten- don or hamstr ing tendons . The a r g u m e n t s for using hamstr ing t endon autografts include ease of harvest ing tendons, ease of tunnel passage, no compromise in knee function by a graft sacrifice, h a n d a lesser potential for patella femoral symptoms than with patients who have had patellar t endon autografts. The major criticism of hamstr ing t endons is that they are of lesser s t rength than the patellar tendon. 12"13 Doubling of the hamstr ing ten- dons with modif ied fixation techniques and the use of the Ticron suture augmenta t ion have negated the ques t ion of graft s trength.

The technique presen ted is a re f inement of the basic procedure that has been used over the past 12 years. Our experience has demons t ra ted that anter ior cruciate liga- ment reconstruct ion using the semi tendinosus and graci- lis tendons has been successful in greater than 90% of our patients in allowing them to re turn to their pre in jury level of activity. 14

REFERENCES

1. Losee RA, Johnson TR, Southwick WO: Anterior subluxation of the lateral tibial plateau: A diagnostic test and operative repair. J Bone Joint Surg [Am] 60A:1015-1030, 1978

2. Moyer RA, Betz RR, Marchetto PA, et ah Arthroscopic anterior cruciate reconstruction using the semitendinosus and gracilis ten- don: Preliminary report. Contemp Orthop 12(1):17-23, 1986

3. Jackson DW, Shaefer RK: Cyclops syndrome: Loss of extension fol- lowing intra-articular anterior cruciate ligament reconstruction. Ar- throscopy 6:171-178, 1990

4. Arnoczky SP, Torzilli PA, Warren FR, et ah Biologic fixation of ligament prostheses and augmentations. An evaluation of bone in- growth in the dog. Am J Sports Med 16(2):106-112, 1988

5. Sapega AA, Moyer RA, Schneck C, et al: Testing for isometry dur- ing reconstruction of the anterior cruciate ligament. J Bone Joint Surg [Am] 72A:259-267, 1990

6. Arnoczky SP: Anatomy of the anterior cruciate ligament. Clin Or- thop 172:19-25, 1983

7. Odenstein M, Mognes J, Gilquist J: Functional anatomy of the an- terior cruciate ligament and a rationale for reconstruction. J Bone Joint Surg [Am] 67A:257-261, 1985

8. DeHaven KE: Perpheral meniscus repair: An alternative to menis- cectomy. J Bone Joint Surg [Br] 63B:463, 1981 (abstr)

9. Grood ES, Noyes FR, Butler DL: Biomechanics of the knee extension exercise. J Bone Joint Surg [Am] 66A:725-735, 1984

10. O'Brien SJ, Warren RF, Pavlov It, et al: Reconstruction of the chron- ically insufficient anterior cruciate ligament with the central third of the patellar ligament. J Bone Joint Surg [Am] 73A:278-285, 1991

11. Lipscombe AB, Johnston RK, Snyder RB, et al: Evaluation of ham- string strength following use of semitendinosus and gracilis ten- dons to reconstruction the anterior cruciate ligament. Am J Sports Med 10:340-342, 1982

12. Butler DL: Strength consideration in selection of ligament grafts. Orthop Today 1:26, 1984 (abstr)

13. Butler DL, Noyes FR, Grood ES, et ah Mechanical properties of transplants in the anterior cruciate ligament. Orthop Trans 4:180, 1980

14. Boden B, Moyer RM, Betz R, et al: Arthroscopically assist ACL reconstruction: A follow up study. Contemp Orthop 20(2):187-194, 1990

RECONSTRUCTION OF ACL WITH HAMSTRING TENDONS 103