Lateral Extra-Articular Tenodesis in Skeletally Immature Patients: The Modified Ellison Technique

Abstract

Background:

Anterior cruciate ligament (ACL) rupture is an increasingly common injury in the young population. Unfortunately, reinjury rates in this population following ACL reconstruction (ACLR) are also very high. As such, lateral extra-articular procedures have been proposed to augment ACLR and shown to reduce reinjury rates. Most techniques use a strip of iliotibial band (ITB) fixed proximally on the distal femur in close proximity to the lateral femoral epicondyle, which in the skeletally immature patient may be closely associated with the distal femoral physis. In addition, there is also a risk of convergence with the femoral tunnel for the ACLR. The modified Ellison technique avoids both of these risks given it is a distally based tenodesis with its fixation point on the proximal tibial epiphysis. The purpose of this video is to describe a modified Ellison technique in a skeletally immature patient.

Indications:

Primary ACLR in skeletally immature patients at high risk of ACL graft rerupture due to their young age, a positive family history of ACL rupture in a first-degree relative, previous contra-lateral ACL rupture, generalized joint hypermobility, high-grade pivot-shift test, and participating in pivoting sports.

Technique Description:

The modified Ellison technique is a distally based lateral extra-articular procedure. A 1-cm strip of ITB is detached from Gerdy’s tubercle, passed beneath the lateral collateral ligament, and reattached back to from where it was removed. The fixation is within the proximal epiphysis of the tibia.

Results:

In a high-risk adult population, the modified Ellison technique has been shown to have a low ACL graft reinjury rate at 2 years following an ACLR. Biomechanical studies have demonstrated that a modified Ellison technique closely restores native knee kinematics following simulated anterolateral complex injury.

Discussion/Conclusion:

The modified Ellison technique is a safe and reproducible lateral extra-articular procedure in skeletally immature patients when performed in combination with an ACLR.

Patient Consent Disclosure Statement:

The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Graphical Abstract

This is a visual representation of the abstract.

Video Transcript

In this video, we will demonstrate a lateral extra-articular tenodesis (LEAT) in a skeletally immature patient with open growth plates using a modified Ellison technique.

These are our disclosures.

A modified Ellison procedure^1,4,5 is recommended in primary anterior cruciate ligament (ACL) reconstruction (ACLR) setting in skeletally immature patients who are at a high risk for ACL graft rupture. Since there are no definitive indications for a LEAT available in the current literature, the risk of reinjury after ACLR is discussed with the patient and their family and a decision to add this procedure to the ACLR is made preoperatively. These specific risk factors are taken in consideration: young age (<20 years), positive family history of ACL rupture (first-degree relative), previous contralateral ACLR, generalized joint hypermobility (Beighton score >5), high-grade pivot-shift test, and participating in pivoting sports. ⁷

This case report shows a 13-year-old male patient with open physes with a left ACL rupture on the background of generalized joint hypermobility. Here you can see the typical pivot-shift bone bruise pattern and the open femoral and tibial physes on the preoperative magnetic resonance imaging (MRI) scan.

The patient is positioned supine on a standard operating table. A high tourniquet is applied and the leg is placed at 70° of flexion using a foot rest and a lateral thigh support. The fluoroscopic C-arm is positioned on the opposite side of the operating table; in this case on the right.

The ACLR is performed prior to the lateral extra-articular procedure. The graft is fixed on the femoral side, but fixation of the tibial side is carried out following the modified Ellison procedure. This video demonstrates a modified Ellison procedure on the left knee.

First, the key anatomic landmarks on the lateral side of the knee are identified: Gerdy’s tubercle and the lateral femoral epicondyle. An incision is made centered between these landmarks. The posterior border of the iliotibial band (ITB) is identified. The aim is to harvest a 10-mm-wide strip of ITB. The first incision of the ITB is made 8 to 10 mm anterior of the posterior border of the ITB. This harvest should be in line with the ITB fibers and run approximately 2 cm proximal to the lateral collateral ligament (LCL). Special care must be taken to not injure the LCL, which is directly underneath.

The ITB is then sharply dissected from its attachment to the Gerdy’s tubercle. In the pediatric population the periosteal attachment of the ITB is cartilaginous. Attention should be paid not to dissect too distally and inadvertently enter the proximal tibial physis. The graft is then freed from soft tissue attachments to its deep surface.

Next, the LCL is identified through the defect in the ITB created by the graft harvest. The knee can be placed in a figure-of-4 position to palpate the LCL more easily. Sharp dissection is performed anterior and posterior to clearly identify the ligament and to create a tunnel for passage of the ITB graft. A blunt artery forceps is passed deep to the LCL to establish a tunnel for the ITB graft. Care must be taken not to injure the proximal attachment of the LCL by being too aggressive with fashioning the tunnel. It is important to have sufficient space to allow smooth passage of the ITB graft and to avoid twisting it.

Once the graft has been passed deep to the LCL and the correct orientation is confirmed, fluoroscopy is used to assess the location of the proximal tibial growth plate. An anteroposterior fluoroscopic image is taken of the proximal tibial epiphysis prior to drilling for the anchor to ensure the orientation avoids the growth plate. A 4.5-mm hole is then drilled at the harvest site on Gerdy’s tubercle, just proximal to the growth plate. A tap is used with the appropriate thread diameter and a double-loaded suture anchor is then inserted. The individual suture limbs are passed through the distal end of the ITB graft. The assistant then gently pulls one pair of sutures distally while the other suture pair is tied over the ITB graft. Then the second suture pair is tied. Finally, the reattachment is reinforced using 3 or 4 absorbable sutures to fix the graft to the margins of the ITB. The proximal defect in the ITB is left open to avoid the potential risk of increased lateral patellofemoral constraint.

In contrast to other techniques of LEAT, the positioning of the foot in external or internal rotation and the degree of flexion in the knee is not relevant because the ITB graft is attached at the same location from where it was detached and is not constrained proximally.^2,8 The final construct shows a LEAT, which is fixed proximal to the tibial growth plate at Gerdy’s tubercle and is passing deep to the LCL.

The postoperative radiograph shows the femoral fixation of the ACLR with an Endobutton and tibial fixation with a fixation post as well as the suture anchor proximal to the open tibial physis.

The rehabilitation protocol after a LEAT is the same as for a routine ACLR protocol, which in our hands allows for full weightbearing as tolerated and no bracing.^3,6 Early focus is on restoration of knee extension and quadriceps activation. Usually, patients commence riding a stationary bike at 3 to 4 weeks postoperatively and return to gym-based exercises at 5 to 6 weeks postoperatively. Running is allowed after restoration of adequate quadriceps strength and once there is no effusion, which is typically at 3 to 4 months after surgery. Participating in team practice is allowed usually at around 6 months postoperatively followed by a sport-specific rehabilitation protocol. Time to return to sports varies but is usually from 11 or 12 months after surgery.

In conclusion, the modified Ellison procedure is a safe additional procedure in skeletally immature patients undergoing ACLR. It avoids the open growth plate on the distal femur, and there is no risk of convergence with the femoral ACLR tunnel. It also avoids the potential risk of having a graft that is too short, as can occur with other techniques of LEAT.

Thank you for your attention.