Abstract
Background:
Bone-patellar tendon-bone (BPTB) graft for anterior cruciate ligament (ACL) reconstruction (ACLR) is the second most common graft worldwide and the most common graft in the United States. Fixation generally consists of screws, which can have risks, such as graft damage or cutting, loss of tension, or suture breakage while fixating. All-inside reconstruction is generally used for soft-tissue grafts and has advantages over full tunnels. Therefore, we present a technique for ACLR using an all-inside BPTB autograft.
Indications:
Patient with symptomatic ACL stability and no signs of patella alta, as this increases the risk of graft-tunnel mismatch.
Technique Description:
Preoperative magnetic resonance imaging is reviewed for tendon length, along with the Ohio State University Graft Metrix Table, which is presented. The patient is positioned supine in a leg holder. Standard anterior incision for patellar tendon harvest is performed, paratenon is preserved, and a 13-mm long and 10-mm wide patellar bone block is harvested along with the middle-third patellar tendon and a 15 to 20 mm long and 10-mm wide tibial bone block. The tibial side is prepared for the femoral tunnel using standard adjustable loop fixation with a cortical button, and the patellar side for the tibial tunnel using quadriceps tendon adjustable loop fixation. Standard femoral and tibial all-inside tunnels are drilled with maximum sockets, and the graft is passed from the anteromedial portal into the joint, the bone plugs are pulled into the sockets, and the adjustable loop fixation is tightened.
Results:
No studies have reported on outcomes of all-inside BPTB ACLR. Soft-tissue graft all-inside fixation has been shown to lead to better patient-reported outcomes, less tunnel widening, better knee laxity, and less pain.
Discussion/Conclusion:
The all-inside ACLR with a BPTB graft is a safe and straightforward technique that can be performed using standard equipment. It has the aforementioned benefits of all-inside tunnel sockets and prevents the potential complications of screw fixation.
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.
Level of Evidence:
Level 5.
This is a visual representation of the abstract.
Keywords
Video Transcript
We present our study, All-inside autograft bone-patellar tendon-bone anterior cruciate ligament reconstruction. These are our disclosures. One or more of the authors has declared a potential conflict of interest as specified in the VJSM Conflict of Interest statement, with the editorial board and paid consultancy as shown here.
Background
In this video, we will review the background, preoperative planning, patient positioning, and procedure of the all-inside bone-patellar tendon-bone (BPTB) autograft anterior cruciate ligament reconstruction (ACLR), along with potential complications, rehabilitation, return to sports, and patient outcomes in the literature.
Indications
We present the case of a 20-year-old male who injured his knee playing basketball 3 months ago. He complains of persistent instability with sports and daily activities. His height is 1 meter 78 centimeters. His physical examination reveals insufficient ACL stability. Radiographs show no osteoarthritis or acute abnormalities and no patella alta. Magnetic resonance imaging (MRI) of T2 sagittal, coronal, and axial slices shows a proximal third junction complete ACL tear with classic bone marrow edema patterns, and a medial meniscus ramp tear. The patellar tendon length is measured at 41 mm.
Technique Description
Standard BPTB equipment is used with a 10-mm saw and a small osteotome. For the femur, the TightRope adjustable loop system is used, and for the Tibia, the FiberTag TightRope with ABS button. The graft length depends on the height of the patient, and the Ohio State University (OSU) Graft Metrics Table is used as shown below. With our patient, we aim for a graft length between 65 and 70 mm to avoid graft-tunnel mismatch. In general, the aim is to drill a 23- to 25-mm femoral socket, which depends on the anatomy, and we consider a 25-mm intra-articular length, which is a conservative estimation. Then, we aim to drill at least 30 mm for the tibial socket. The tibial socket can be adjusted by increasing the inclination angle if this is required. In this case, the anatomy shows a 31-mm femoral bone distance, which leads to a 24-mm socket, considering the 7-mm hub of the Arthrex guide. Similarly, with a 60° inclination angle, a 37-mm tibial bone distance will lead to a 30-mm tibial socket. The total length is then 24 + 25 + 30, which equals 79 mm for this specific case, which is safe for this graft length. We recommend a safety margin of approximately 1 cm.
Patient positioning is supine with a leg holder. A tourniquet is placed on the thigh, but only inflated for 10 minutes during harvest.
After a midline incision, the paratenon is incised and released, and the tendon is exposed. The middle third of the patellar tendon is incised using a 10-mm dual blade, and the patellar bone block is harvested with a saw and then an osteotome. No mallet should be used with the osteotome to avoid patellar fracture. A 13-mm-long and 10-mm-wide bone block is harvested. A smaller bone block decreases the risk of patella fracture and makes passing into the tunnel easier. The bone block is left with its adhesions to prevent it from falling out after the tibial cut. The tibial bone block is then cut to a 10-mm width and 15- to 20-mm length, and an osteotome with a mallet can be used to cut the tibia. The adhesions are cut, and then the patellar length is reviewed to determine if indeed all-inside reconstruction is possible. On the back table, it is confirmed that the tendon length is similar to the preoperative measures and that a total graft length between 65 and 70 mm is possible with sufficient bone blocks between 10 and 15 mm. The tibial bone block becomes the femoral side, and the patellar bone block the tibial side. Two holes are drilled in the femoral side—1 in the proximal third and 1 very close to the tendon. One hole is drilled in the tibial side. For the femoral side, a rescue stitch is made by passing it through the hole close to the tendon and through the tendon. Then, the TightRope mechanism is loaded through the proximal drill hole, and the mechanism is loaded in standard fashion. The end product is a femoral bone block with adjustable loop button fixation and a rescue stitch, as shown at the end. The tibial side is then prepared as if it were a Quadriceps tendon graft using the FiberTag TightRope. Because of the smaller 10 by 12 mm bone block, this gives extra security to the graft and avoids ripping through. The sutures are passed through the tendon in standard fashion, which is not completely shown here, and through the drilled hole. The result is shown here. The graft is sized in standard fashion, the length is remeasured, and the bone-tendon junctions are marked for identification during graft passage.
During arthroscopy, the torn ACL with an empty notch is confirmed, the ACL remnant is debrided, and a small notchplasty is performed. Using a curette, an indentation is made at the desired location, high and deep on the femoral wall, and this is checked with the probe. Then, a femoral tunnel is drilled with a retrograde drill. The arthroscope is switched to the anteromedial portal, and a very deep and high tunnel position is confirmed with only a 1-mm back wall. A possible minimal blow-out can be tolerated, as fixation is with a button over the femoral cortex. A passing suture is passed through and retrieved out of the anteromedial portal. The total length on the retrograde drill can be read, and the socket depth can be measured by distracting 7 mm (for the hub of the guide) from the read depth, but this depends on the type of all-inside reamer.
Using standard landmarks of the posterior border of the anterior horn of the lateral meniscus and the medial eminence, a 10-mm tibial tunnel is drilled. A passing suture is passed up the tibial tunnel, and both passing sutures are grasped together in the joint and retrieved to avoid a soft-tissue bridge. The medial portal is extended to fit the graft. The femoral sutures of the graft are passed through the passing sutures, and the graft is shuttled into the joint. The graft is passed into the joint and into the femoral tunnel. The graft is then pulled back to pull the button flush on the femoral cortex. The white shortening sutures are used to shuttle the bone block into the femoral tunnel, and the passage is helped by a probe. Once the bone block is in the femur, the tibial shuttle sutures are used to pull the tibial side of the graft into the tibial tunnel. As seen here, there is immediately good tension of the graft and no signs of bottoming out. After final fixation, there is good tension of the graft, and no signs of impingement. Here is externally shown how the tibia ABS button is loaded and how the white shuttle sutures are used to tension the button down with the knee in extension.
Results
Potential complications should be avoided, the most important of which is graft-tunnel mismatch. The patient's height and patellar tendon length on MRI and the OSU Graft Metrics Table should be reviewed. RetroDrilling should be performed, and maximal sockets should be drilled. If needed, the tibial tunnel inclination angle can be adjusted for a longer tibial tunnel, as shown before. As a contingency plan, a full tibial tunnel with a screw or button extender can be used. Furthermore, if the sutures cut through the smaller bone block, the rescue sutures can be additionally fixed with back-up fixation using an anchor. Finally, one should also ensure that the button is flush on the femoral cortex, either by palpation or fluoroscopy, and the graft should be fixed in extension to avoid overconstraint or graft stretching.
Discussion/Conclusion
BPTB graft for ACLR is the second most used graft worldwide, and most used in the United States, and screw fixation is almost always preferred. 6 From the soft-tissue graft literature, all-inside fixation has several advantages, as a meta-analysis of randomized trials recently showed slightly better patient-reported outcome measures, less tunnel widening, and better laxity. 5 A randomized controlled trial also showed less pain with all-inside tibial tunnels. 4 To date, only 1 technique 1 has been published on all-inside BPTB ACLR, but this was 15 years ago using a retroscrew, which is cumbersome and not available anymore.2,3 We present a straightforward and reproducible technique for all-inside BPTB ACLR with standard all-inside instrumentation.
Footnotes
One or more of the authors has declared the following potential conflict of interest or source of funding: J.P.V. is on the editorial board of Arthroscopy and received fellowship education from Arthrex and Smith & Nephew; R.B. is affiliated with education CDC Medical LLC. C.C.K is a paid consultant for Arthrex. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.
