Posterior Hamstring Harvest and Preparation for Quadruple Autograft All-Inside Anterior Cruciate Ligament Reconstruction

Video Transcript

We present our study of posterior hamstring harvest and preparation for quadruple autograft all-inside anterior cruciate ligament (ACL) reconstruction.

In this video, we review the background, preoperative planning, patient positioning, and procedure of the posterior hamstring harvest and graft preparation, along with potential complications, rehabilitation, and return to sports and patient outcomes in the literature.

Background

We present the case of a 44-year-old woman who presents 4 weeks after a skiing injury and indicates instability with daily activities. She works as a nurse and enjoys skiing, running, tennis, and fitness. Her body mass index is 24 kg/m², and her height is 1 m, 63 cm. Radiographs reveal no evidence of osteoarthritis or acute abnormalities. Magnetic resonance imaging of T2 sagittal, coronal, and axial slices shows a proximal third junction complete ACL tear with classic bone marrow edema patterns, a medial meniscus tear, and mild chondromalacia patellae.

Indications

The atraumatic hamstring harvester, shown on the right top of the slide with the black handle, and the closed hamstring harvester, shown on the right bottom of the slide with the silver handle, are used. Graft length is important for all-inside ACL reconstruction to avoid graft-tunnel mismatch. The following graft lengths are used for patients of varying heights. ⁴ In this case, the semitendinosus length was 26 cm, which we will quadruple for a graft length of 65 mm. The standard method of the senior author (C.C.K.) for all hamstring ACL reconstructions is to harvest the hamstring tendons from posterior, as this has the advantages of less iatrogenic nerve damage, lower risk of premature graft harvest and no need to release the vincula or any other adhesions, shorter operative time, and higher satisfaction with cosmetics, which are all discussed at the end of the presentation in detail.

Patient positioning is supine with a leg holder to the preference of the senior author. At the beginning of the case, leg extension and elevation out of the leg holder should be possible for graft harvest. Leg position and flexion angle differ throughout graft harvest, as shown here and displayed in the upcoming videos.

Technique Description

The hamstring tendons are palpated with the knee in 90° of flexion, and then, using a No. 10 blade, a transverse skin incision is made approximately 1 cm proximal to the flexion crease over the hamstring tendons with the knee in extension. The fascia is identified and opened. Care should be taken to incise only the fascia and not the underlying semitendinosus tendon. The semitendinosus is the most lateral of the medial hamstring tendons and is freed using a right-angle clamp.A free suture is looped around the tendon. Then, the atraumatic open hamstring harvester is placed over the tendon, and the tendon is harvested proximally, with a smooth, continuous movement and a combination of pushing with the harvester and pulling the tendon while the knee is at 30° of flexion. Muscle is then released from the tendon using Mayo scissors. There is no need to release any vincula or adhesions as the hamstring is harvested from the proximal aspect of these, which is a significant advantage over anterior harvest. The graft is passed through the closed tendon stripper and held with a hemostat. Then, the distal part of the tendon is harvested with the knee in 30° of flexion or extension, and the graft is brought to the back table. Again, there is no need to release the vincula or adhesions.

The graft preparation station is set up with the femoral button on the right and an adjustable loop for future tibial button on the left. The graft is passed through the loops 4 times, and the graft ends are clamped together with a hemostat. The graft is then tensioned and the length reviewed. If the tendon is too long, more overlap between the graft ends will result in a shorter total length. The graft is now preliminarily fixated using 2-0 nonabsorbable sutures. After fixation, the graft is tensioned again, and both graft length and graft diameter can be assessed using graft sizers. The sutured ends are moved to the inside of the graft and to the femoral or tibial end, depending on surgeon preference. Adjustments can be made for length and diameter as demanded. If the graft is not of sufficient diameter or length, the gracilis tendon can be harvested in a similar fashion to the semitendinosus harvest. The graft is now sutured using 2-0 nonabsorbable sutures. Suturing is started on the inside of the graft approximately 15 mm from the end and then passed twice through all 4 strands before suturing from outside back to the middle of the graft. The sutures are then tied and docked away and cut short, such that no sutures are prominent on the outside of the graft. This process is then repeated one more time for the femoral side and twice for the tibial portion, and these steps are not shown here. The femoral and tibial sides are then marked 15 mm from the end of the graft, which can help during graft docking, as these lines should be in the femoral and tibial sockets after graft passage. The graft is kept at the back table in a tobramycin-infused saline solution prior to graft passage and fixation. Standard all-inside graft passage and fixation are performed with femoral and tibial buttons, but this procedure remains outside the scope of this technique video.

Some potential complications should be avoided. Identification of the semitendinosus is important, and the tendon is the most lateral of the medial hamstrings and can be palpated superficially with the knee in 90° flexion just above the flexion crease. Also, the fascia should be carefully opened, as the semitendinosus is located directly underneath it. Finally, graft-tunnel mismatch should be avoided, and attention should be paid to the patient's height. When drilling all-inside tunnels, one should ensure to drill sufficient bone tunnels, adjusting the tibial tunnel inclination angle for more length.

Results

Standard ACL reconstruction rehabilitation is followed with initial weightbearing and range of motion, depending on concomitant procedures such as meniscus repair. Specifically for this type of ACL reconstruction, isotonic resisted hamstring exercises should be avoided for 8 weeks. Return to sports should be allowed at a minimum of 8 months, provided the displayed criteria are met.

Discussion/Conclusion

Hamstring tendons are the most commonly used graft for ACL reconstruction and are usually harvested through an anterior approach.^6,7 Posterior harvesting, however, has several advantages over anterior harvesting, as there is less risk of nerve damage, ⁶ a lower risk of premature graft harvest as the vincula do not need to be identified and cut,^1-3,5,6 shorter operative time,^2,6 and higher cosmetic satisfaction.^2,6 Therefore, posterior harvesting should be considered when performing hamstring autograft ACL reconstruction.

These are our references. Thank you for your attention.