Editorial Commentary: Tunnel Widening After Anterior Cruciate Ligament Reconstruction May Increase Laxity and Complicate Revision

Tunnel widening (TW) after anterior cruciate ligament (ACL) reconstruction has been a research area of interest in ACL reconstruction. It has been demonstrated that femoral tunnels enlarge anteriorly and distally (ie, the direction where the mechanical traction force of the graft works) rather than concentrically after anatomic double-bundle ACL reconstruction using hamstring autografts. This finding suggests that the wall supporting the graft moves closer to the direction of the pull, leading to increased laxity of the knee joint due to TW. The causes of TW are presumed to be multifactorial, with both biological and mechanical features. Biological factors include osteolytic cytokines that enter the space between the graft and the bone through the synovial fluid. Mechanical factors include longitudinal graft motion by extracortical femoral fixation (known as the bungee effect), transverse graft motion (also called the windshield-wiper effect), improper graft placement, higher initial graft tension, accelerated rehabilitation, and so on. Although TW does not seem to affect short-term clinical outcomes from studies published to date, it is plausible to speculate that the expansion of the bone tunnel (ie, the edge where the graft tendon is fixed) would theoretically increase joint laxity to some extent, and it would be premature to conclude that TW has no effect on clinical outcomes relative to graft–tunnel micromotion. In addition, there is a general consensus that the presence of expanded tunnels often severely complicates revision ACL reconstruction. In ACL reconstruction using the hamstring tendon, it is necessary to take into account the possibility of a shift in the tunnel position when determining the location of the femoral tunnel.     

Arthroscopic anterior cruciate ligament reconstruction with quadriceps tendon composite autograft

At present, no single graft option clearly outperforms another. Autografts (patellar tendon, hamstring) and allografts (Achilles tendon, patellar tendon) are the grafts most often used. However, each grafts has advantages and disadvantages. Quadriceps tendon graft for anterior cruciate ligament reconstruction is not new, but an alternative composite graft is introduced here that consists of quadriceps tendon–patellar bone and bone obtained from a coring reamer used to create the tibial tunnel. This composite graft retains reduced morbidity while allowing the secure bone-to-bone fixation associated with bone–patellar tendon–bone graft.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 17, No 5 (May-June), 2001: pp 546–550     

Anatomische vordere Kreuzbandersatzoperation mittels Semitendinosus- und Grazilissehne in fremdmaterialfreier Press-fit-Technik

An innovative technique for anterior cruciate ligament (ACL) reconstruction has been developed in 1998 which allows the grafts to be fixed by press-fit to the femoral and tibial tunnel without any hardware. The semitendinosus (ST) and gracilis tendons (GT) are built into a sling by tying a knot with the tendon ends and securing the knot after conditioning by sutures. For the femoral tunnel the anteromedial porta is used. The correct anatomic position of the single femoral tunnel is checked using intraoperative lateral fluoroscopy by placing the tip of a K-wire to a point between the anteromedial and posterolateral bundle insertion sites. A femoral bottleneck tunnel is drilled to receive the knot of the tendons. The tendon loops filled the tibial tunnel without any suture material. The loops are fixed at the tibial tunnel outlet with tapes over a bone bridge. Between 1998 and 1999 a prospective randomized study (level 1) was conducted comparing this technique with a technique using bone-patellar-tendon graft and press-fit fixation without hardware. In conclusion it was found that implant-free press-fit ACL reconstruction using bone-patella-tendon (BPT) and hamstring tendon (HT) grafts proved to be an excellent procedure to restore stability and function of the knee. Using hamstring tendons (ST and GT) significantly lower donor site morbidity was noted. Kneeling and knee walking pain persisted to be significantly more intense in the BPT up to 9 years after the operation. Re-rupture rates, subjective findings, knee stability and isokinetic testing showed similar results for both grafts. This is the first level I study which demonstrates cartilage protection by ACL reconstruction as long as the meniscus is intact at index surgery, shown by bilateral MRI analysis 9 years post-operation. There was no significant difference in the average grade of chondral and meniscus lesions between BPT and HT and in comparison of the operated to the intact knee, except for grade 3-4 lesions found at the 9 year follow-up, which were significantly higher in the BPT group.     

Vordere Kreuzbandersatzplastik

Rupture of the anterior cruciate ligament (ACL) is the most frequent ligamentous injury in the knee. The goal of its surgical reconstruction is the restoration of stability so that the roll-and-glide mechanism is as close as possible to normal. The indications for reconstruction are becoming more numerous. The tendons most commonly used for grafts are the patellar, hamstring and quadriceps tendons; the one selected depends on the patient’s needs. Despite technical improvements (in placement and fixation of the grafts), the risk of technical failures and intraoperative complications is still up to 20%. Besides the well-known problems with graft harvesting, the windshield-wiper effect and incorrect placement of the drilling tunnels are the most common reasons for revision surgery.     

All-Inside Anterior Cruciate Ligament Reconstruction

Anterior cruciate ligament (ACL) reconstruction is one of the most commonly performed knee operations. An “all-inside” technique creates bone sockets for ACL graft passage, as opposed to more traditional full bone tunnels, and typically incorporates suspensory fixation instead of screw fixation to secure the graft. This technique may be indicated for any ACL reconstruction surgery, where adequate bone stock exists to drill sockets and to use cortical fixation. The technique may be used with all soft tissue, as well as bone plug ACL grafts and autograft hamstring or quadriceps tendon; most allograft tendon options may be performed with an all-inside technique. Advantages include anatomic tunnel/socket placement, decreased postoperative pain and swelling, minimal hardware, appropriate graft tensioning and retensioning, and circumferential graft to bone healing. Tips for successful all-inside surgery include matching graft diameter to socket diameter, drilling appropriate length sockets based on individual graft length, so as not to “bottom out” the graft and confirming cortical button fixation intraoperatively. Potential complications include graft-socket mismatch, full-tunnel reaming, and loss of cortical fixation. Multiple studies have shown the all-inside technique to have similar or superior biomechanical properties and clinical outcomes compared to the more traditional full-tunnel ACL reconstruction techniques.     

双股腘绳肌腱重建解剖学形态的前交叉韧带

目的探讨经双股骨和3个胫骨隧道用双股腘绳肌腱移植,重建解剖学形态前交叉韧带的可行性和效果。方法使用关节镜技术准确的确立出前交叉韧带起止点位置,并钻取2个股骨和3个胫骨隧道,将双股腘绳肌腱分为3束重建解剖学形态的前交叉韧带。结果所有病例随访8~15个月,膝关节功能恢复满意。结论前交叉韧带重建技术更能发挥膝关节生物力学性能,具有广泛的应用前景。     

Quadriceps tendon-patellar bone autograft for anterior cruciate ligament reconstruction: a technical note

The quadriceps tendon autograft can be used for primary and revision anterior cruciate ligament (ACL) reconstruction. Despite several successful clinical reports, graft fixation issues remain, and the ideal technique for fixation continues to be controversial. We present a technique of ACL reconstruction with quadriceps tendon autograft (QTA) using a patellar bone block. The tendon end is fixed in the femoral tunnel and the bone plug in the tibial tunnel using reabsorbable interference screws. The advantages of this technique are related to the increase in stiffness of the graft, the achievement of a more anatomic fixation, and a reduction in synovial fluid leakage.     

Editorial Commentary: Large-Diameter Quadrupled Hamstring Autografts Are an Acceptable Option for National Collegiate Athletic Association Division I College Football Players: We Must Challenge Our Comfort Zone to Be Successful in the End Zone

The majority of surgeons caring for elite American football teams choose bone–patellar tendon–bone (BTB) autograft for anterior cruciate ligament reconstruction. As we strive to continue to improve currently favorable outcomes, we need to consider all options regarding graft choice, surgical technique, and postoperative rehabilitation. Advantages of BTB include an excellent track record, potential for faster incorporation with bone-to-bone healing. Disadvantages include risk of patellar fracture/tendon rupture and anterior knee pain. The pros of quadrupled hamstring (QH) graft include stronger graft (higher ultimate load to failure) and less anterior knee pain and stiffness, and the cons include loss of flexion/hamstring strength and slower healing in the tunnels. Several studies have shown that smaller grafts have higher failure rates, and recent research shows that QH grafts >9 mm had decreased risk of revision compared to BTB. We can now quadruple the semitendinosus tendon to provide elite athletes with even more robust grafts. Large-diameter QH autografts are an acceptable option for National Collegiate Athletic Association Division I college football players.     

Anatomic Double Bundle: A New Concept in Anterior Cruciate Ligament Reconstruction Using the Quadriceps Tendon

Surgical procedures for double-bundle anterior cruciate ligament reconstruction, which currently use hamstring graft, have been described, but some concerns remain regarding graft fixation and the ability to obtain adequate bundle size. We report an original double-bundle anterior cruciate ligament reconstruction technique using a quadriceps tendon graft and a simplified outside-in femoral tunnel–drilling process. The graft consists of a patellar bone block with its attached tendon split into superior and inferior portions, which yields 2 bundles. The anteromedial tunnel is drilled from the outside through a small lateral incision by use of a guide. The posterolateral tunnel is made through the same incision with a specific guide engaged in the anteromedial tunnel. A single tibial tunnel is created. The graft is routed from the tibia to the femur with the bone block in the tibial tunnel and the 2 bundles in their respective femoral tunnels. After fixation of the bone block in the tibia, the 2 bundles are tensioned and secured separately in their femoral tunnels.     

Anterior Cruciate Ligament Reconstruction: A New Technique for Achilles Tendon Allograft Preparation

We describe a new technique in Achilles tendon allograft preparation for use in anterior cruciate ligament (ACL) reconstruction that allows for secure bony interference fixation on each side of the joint and aperture fixation for all patients. In addition, preparation of the graft in this manner avoids some problems that are frequently encountered with patellar tendon allografts, including graft tunnel mismatch and limited availability. Previous studies have reported successful results with Achilles tendon allograft use in ACL reconstruction with soft tissue fixation in the tibial tunnel. Bony interference fixation on the tibial side can be achieved by suturing a free bone plug to the tendon end of an Achilles allograft. We use a 9-mm circular oscillating saw to harvest a free 30-mm length bone plug from the remaining calcaneal bone block. This is then sutured directly to the tendon end of a bone-Achilles tendon allograft with the use of No. 1 nonabsorbable suture placed through 3 equally spaced drill holes in the free bone plug. Tendon length between the bone plugs can be individually set for each patient at a distance equivalent to the length of the native ACL (intra-articular distance between the femoral and tibial tunnels). After graft passage, the construct is tensioned and secured with interference screws, similar to a traditional bone–patellar tendon–bone graft. The senior author (S.G.) has performed 40 procedures with excellent results and reports no cases of tibial fixation failure. Biomechanical and long-term follow-up studies are in progress.     

Anatomical reconstruction of the patellar tendon: a new technique with hamstring tendons and iliotibial tract.

A new technique of patellar tendon reconstruction was performed in a patient who lost tendon and tibial tuberosity during wide excision surgery for a malignancy. In this procedure, the tendon was anatomically replaced by a graft composed of ipsilateral hamstring tendons and iliotibial tract, with the biomechanical conditions considered. Both ends of the graft were secured in the size-matched bone tunnels in the patella and tibia by screw post fixation, which is a technique established in ligament reconstruction surgery in the knee joint. At the twenty-month follow-up, the result was deemed successful.     

In vitro comparison of elongation of the anterior cruciate ligament and single- and dual-tunnel anterior cruciate ligament reconstructions.

This study evaluated strain in the normal anterior cruciate ligament (ACL) and compared it to four different double-strand hamstring tendon reconstructive techniques. Seventeen fresh-frozen knees from 11 cadavers were tested. The strain in the anteromedial and posterolateral bands of the native ACL and their equivalents in four autograft techniques were measured using differential variable reluctance transducers. The anteromedial band of the intact ACL shortened from 0 degree -30 degrees of flexion, then lengthened to 120 degrees; the posterolateral band of the intact ACL shortened from 0 degree - 120 degrees of flexion. Following ACL excision, these knees underwent reconstruction with double-strand hamstring tendons with either single tibial and femoral tunnels, single tibial and dual femoral tunnels, dual tibial and single femoral tunnels, or dual tibial and dual femoral tunnels. With the exception of the dual-band, dual-tunnel technique, all of the procedures placed greater strain on the reconstructive tissues than was observed on the native ACL, after approximately 30 degrees of flexion. These results indicate that dual-band hamstring tendon reconstructions placed with single tibial and femoral tunnels do not address the complexity of the entire ACL. Rather, these procedures appear to only duplicate the effect of the anteromedial band, while perhaps overconstraining the joint as a result of its inability to reproduce the function of the posterolateral band. During rehabilitation following ACL reconstruction, therefore, only from 0 degree - 30 degrees of the graft tissues are not significantly strained. Dual tibial and femoral tunnel techniques should be evaluated further to more closely recreate knee kinematics following ACL reconstruction.     

Technical Note: Double tibial tunnel using quadriceps tendon in anterior cruciate ligament reconstruction

Summary: To avoid complications related to the use of patellar tendon and hamstring (semitendinosus and gracilis) tendon and to create a more anatomic reconstruction, we present a new technique based on the use of quadriceps tendon placed in a single half femoral tunnel and double tibial tunnels. The graft, harvested by a central longitudinal incision, possesses the following characteristics: (1) a bone plug 20 mm long and 10 mm in diameter; (2) a tendon component 7 to 8 cm long, 10 mm wide, and 8 mm thick; and (3) division of the tendon longitudinally into 2 bundles while maintaining the patellar insertion. Every bundle has a width and thickness of approximately 5 mm and 8 mm, respectively. The total length of the graft is 9 to 10 cm. A 10-mm half femoral tunnel is drilled through a low anteromedial portal with the knee flexed at 120°. A suture loop is left in place in the half tunnel. A double tibial tunnel is drilled in a convergent manner (from outside to inside) obtaining an osseous bridge between the 2 tunnels. Two suture loops are passed trough the tibial tunnels and retrieved in a plastic cannula (10 mm) positioned in the anteromedial portal to allow the passage of the 2 bundles in the tibial tunnels. The suture loop left in the half tunnel permits the transportation of the bone plug in the femoral tunnel. Fixation is achieved by an interference screw at the femoral side and by 2 absorbable interference screws (1 for each tunnel). The advantages of this technique are a more cross-sectional area (80 mm²), greater bone-tendon interface, and a more anatomic reconstruction. Theoretically, easier bone incorporation, decreased windshield wiper and bungee effect, fewer donor site problems, and less tunnel enlargement can also be possible.     

Extensor Mechanism Disruption After Contralateral Middle Third Patellar Tendon Harvest for Anterior Cruciate Ligament Revision Reconstruction

The contralateral central third patellar tendon autograft is a reliable graft choice for revision, and recently, for primary reconstruction of the anterior cruciate ligament (ACL). We report 2 complications including a lateral third tibial tuberosity fracture and a distal patellar tendon avulsion with contralateral patellar tendon autograft with disruption of the extensor mechanism of the donor knee. A patient sustained a lateral tibial tuberosity fracture of the donor knee and underwent open reduction and internal fixation. At 1-year follow-up, she had no extensor lag and full range of motion. Another patient sustained a distal patellar tendon avulsion of the donor knee and underwent primary repair. Three years postoperatively, she had a full range of motion and no extensor lag. Although contralateral middle third patellar tendon autograft for primary and revision ACL reconstruction is established in the literature, extensor mechanism complications can occur. Technical considerations are important to avoid weakening the remaining patellar tendon insertion. Postoperative nerve blocks or local anesthetics may alter pain feedback for regulation of weight bearing and contribute to overload of the donor knee.     

Anatomically Oriented Anterior Cruciate Ligament Reconstruction with a Bone–Patellar Tendon–Bone Graft via Rectangular Socket and Tunnel: A Snug-fit and Impingement-Free Grafting Technique

An anterior cruciate ligament (ACL) reconstruction technique is described to place bone–patellar tendon–bone (BPTB) graft in an anatomically oriented fashion to mimic the 2 bundles of the normal ACL, based on the concept of twin tunnel ACL reconstruction, to maximize the graft-tunnel interface. In this technique, the attached bone plug is introduced into a rectangular femoral socket via a halfway rectangular tibial tunnel for the anterior portion of the graft to function as the anteromedial bundle and for its posterior portion to behave as the posterolateral bundle. A snug fitting of the graft is achieved not only at the femoral socket, but also in the tibial tunnel.     

Editorial Commentary: Goldilocks and the Three Grafts: Managing Tendon Harvest and Graft Length Problems in Autograft Anterior Cruciate Ligament Reconstruction

Autograft hamstring tendon harvest in anterior cruciate ligament (ACL) reconstruction can occasionally result in a graft length that is inadequate for creation of a robust ACL graft. Patients at risk for an abnormally short hamstring may also be high risk for ACL reinjury. Graft augmentation with allograft may be a suboptimal solution to this problem. Therefore, a reliable means for preoperative estimation of hamstring tendon length by magnetic resonance imaging measurement could avoid this pitfall. However, even with a reliable correlation between magnetic resonance imaging measurement and actual harvested tendon length, establishing a simple, clinically relevant threshold below which hamstring grafts should be avoided remains elusive. By contrast, all-soft-tissue quadriceps autograft avoids the potential length problems inherent to both bone tendon bone (graft–tunnel mismatch) and hamstring tendon grafts, but intermediate- and long-term outcome studies are still needed to validate all-soft-tissue quadriceps autograft in ACL reconstruction.     

Scientific justification and technique for anterior cruciate ligament reconstruction using autogenous and allogeneic soft-tissue grafts

The DLSTG is the strongest and stiffest autogenous graft source available for reconstruction of the torn anterior cruciate ligament. Harvest morbidity is low compared with other autogenous graft sources, such as the patellar bone-tendon-bone graft. Soft-tissue allografts provide an excellent alternative for patients requiring revision surgery or for patients who want to avoid any morbidity associated with autogenous graft harvest. Successful use of any soft-tissue graft source, however, relies on precise placement of the tibial and femoral tunnels to prevent roof and PCL impingement and to restore tensile behavior in the graft tissue similar to the native ACL. The use of high-strength, high-stiffness fixation devices that secure the graft at the end of the tunnel promote tendon tunnel healing, restore stability without high graft tensioning, and allow safe, aggressive rehabilitation. The Bone Mulch Screw/WasherLoc screw system provides the surgeon with a consistent, reproducible technique that restores stability and function to the ACL-deficient knee using a soft-tissue graft in both males and females.     

Biomechanical comparison of hamstring and patellar tendon graft anterior cruciate ligament reconstruction techniques: The impact of fixation level and fixation method under cyclic loading

Purpose: To mechanically test different reconstruction techniques of the anterior cruciate ligament (ACL) under incremental cyclic loading and to evaluate the impact of the level and method of graft fixation on tensile properties of each technique. Type of Study: In vitro biomechanical study. Methods: Four hamstring and 1 patellar tendon reconstruction techniques were performed on 40 young to middle-aged human cadaveric knees (average age, 39 years). An anterior drawer with increasing loads of 20 N increments was applied at 30° of knee flexion. Anatomic, direct interference screw fixation was tested in 2 hamstring and in the patellar tendon groups. Nonanatomic (extracortical) graft anchorage was tested in the remaining 2 hamstring groups with indirect graft fixations on both sides and the combination of indirect tibial and direct femoral fixation. Structural properties were determined throughout the cyclic loading test. Results: The more anatomic reconstruction techniques provided significantly higher structural properties and smaller loss of fixation compared with nonanatomic, extracortical fixation, with indirect repair on both fixation sites resulting in the lowest structural properties. The tibial fixation site was the weakest link in all of the anatomic reconstructions. Patellar tendon fixation with attached bone blocks in both bone tunnels significantly improved construct stiffness and decreased graft slippage. Conclusions: The results of this study suggest that anatomic fixation should be preferred for anchorage of hamstring tendons and linkage materials should be avoided. Direct soft-tissue fixation with interference screws still allows considerable graft slippage, which can be limited by using a bone block or application of a backup or hybrid fixation, especially on the tibial fixation site.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 18, No 3 (March), 2002: pp 304–315     

前交叉韧带重建术后骨道增宽的临床研究

目的分析前交叉韧带（ACL）重建术后骨道增宽的发生率、增宽程度、骨道形状、相关因素及其与临床效果的关系。方法回顾性研究应用胭绳肌腱重建ACL手术后骨道的变化,通过X线片测量ACL重建术后的骨道直径。对51例患者行ACL重建手术,其中男性30例,女性21例。所有患者均获随访,平均随访时间16个月。主要研究及观察指标：患者性别、年龄、身高等因素,移植物的固定方式,随访时的关节活动度、膝关节稳定性检查（KT2000）及肌力恢复情况,以及股骨和胫骨的骨道直径、骨道位置和角度等。数据分析采用统计学卡方检验及相关性分析。结果前交叉韧带重建术后的骨道增宽率股骨85％-94％,胫骨65％;增宽程度股骨51％-53％,胫骨40％～44％。胫骨骨道增宽的形态以O型（冠位片）及V型（矢位片）最常见。骨道增宽与年龄、身高及体重指数相关。股骨骨道位置偏前会引起股骨骨道的增宽,股骨骨道角或胫骨骨道角越小,则股骨骨道越容易增宽。结论以腘绳肌腱为移植物重建前交叉韧带手术,术后骨道增宽的发生率与程度,股骨骨道较胫骨骨道明显。骨道增宽与患者年龄、身高以及骨道定位相关,其中股骨和胫骨骨道的位置及角度是引起术后骨道增宽的主要因素之一。骨道增宽与KT2000结果和术后肌力恢复情况相关。     

Arthroscopic anterior cruciate ligament reconstruction with quadriceps tendon-patellar bone autograft

BACKGROUND: Surgical reconstruction of the anterior cruciate ligament (ACL) is indicated in the ACL-deficient knee with symptomatic instability and multiple ligaments injuries. Bone patellar tendon-bone and the hamstring tendon generally have been used. In the present study, we describe an alternative graft, the quadriceps tendon-patellar bone autograft, by using arthroscopic ACL reconstruction. METHODS: From March of 1996 through March of 1997, a quadriceps tendon-patellar bone autograft was used in 12 patients with ACL injuries. RESULTS: After 15 to 24 months of follow-up, the clinical outcome for those patients with this graft have been encouraging. Ten patients could return to the same or a higher level of preinjury sports activity. According to the International Knee Documentation Committee rating system, 10 of the 12 patients had normal or nearly normal ratings. Recovery of quadriceps muscle strength to 80% of the normal knee was achieved in 11 patients in 1 year. CONCLUSION: The advantages of the quadriceps tendon graft include the following: the graft is larger and stronger than the patellar tendon; morbidity of harvest technique and donor site is less than that of patellar tendon graft; there is little quadriceps inhibition after quadriceps harvest; there is quicker return to sports activities with aggressive rehabilitation. A quadriceps tendon-patellar autograft is a reasonable alternative to ACL reconstruction in patients who are not suitable for either a bone-patellar tendon-bone autograft or a hamstring tendon autograft.