Components of laxity in interference fit fixation of quadrupled hamstring grafts

We tested in vitro 15 Poly-L-lactic acid and 14 titanium interference screws in male human cadaver tibia-hamstring constructs. Elongation of the graft, displacement of the screw in the tibial tunnel, and slippage at the graft/screw interface were measured as outcomes with an infrared optical system. All constructs failed by slippage of the graft past the interference screw. On average, graft slippage accounted for 92% of total construct laxity at 5mm total construct elongation, whereas permanent stretching of the midsubstance of the graft accounted for only 8%. Movement of the interference screw in the tibial canal was minimal, averaging 0.01 (0-0.5) mm at construct failure. Inadequacy of isolated tibial interference screw fixation of soft tissue grafts may be overcome if early failure at the graft/screw interface is prevented.     

Components of laxity in interference fit fixation of quadrupled hamstring grafts

We tested in vitro 15 Poly-L-lactic acid and 14 titanium interference screws in male human cadaver tibia-hamstring constructs. Elongation of the graft, displacement of the screw in the tibial tunnel, and slippage at the graft/screw interface were measured as outcomes with an infrared optical system. All constructs failed by slippage of the graft past the interference screw. On average, graft slippage accounted for 92% of total construct laxity at 5mm total construct elongation, whereas permanent stretching of the midsubstance of the graft accounted for only 8%. Movement of the interference screw in the tibial canal was minimal, averaging 0.01 (0-0.5) mm at construct failure. Inadequacy of isolated tibial interference screw fixation of soft tissue grafts may be overcome if early failure at the graft/screw interface is prevented.     

The EndoPearl device increases fixation strength and eliminates construct slippage of hamstring tendon grafts with interference screw fixation

Purpose: The EndoPearl (Linvatec, Largo, FL), a biodegradable device to augment the femoral interference screw fixation of hamstring tendon grafts has been developed. The first objective of this study was to compare the initial fixation strength of quadrupled hamstring tendons and biodegradable interference screw fixation with and without the application of the EndoPearl device. The second objective was to determine the influence of the EndoPearl device on the fatigue behavior under incremental cyclic loading conditions in a simulation of critical fixation conditions. Type of Study: Biomechanical study. Methods: Fresh human hamstring tendons were harvested and grafts were fixed with biodegradable poly-L-lactide interference screws. Twenty proximal calf tibias were used to compare the initial fixation strength of the study and the control group. In the study group, the EndoPearl device was secured to the graft using two No. 5 Ethibond sutures (Ethicon, Somerville, NJ). Specimens were loaded until failure in a materials testing machine. For cyclic testing, human hamstring tendons and 20 distal porcine femurs were used. Critical graft fixation conditions were simulated by increasing tunnel diameter 2 mm over the graft diameter. Grafts were loaded progressively in increments of 100 N until failure; 100 cycles were applied per load increment. Results: Graft fixation with the additional EndoPearl device had a significantly higher maximum load to failure (658.9 ± 118.1 N v 385.9 ± 185.6 N, P =.003) and stiffness (41.7 ± 11 N/mm v 25.7 ± 8.5 N/mm). Graft fixation with the EndoPearl device sustained a significant higher total number of cycles (388.5 ± 125.6) compared with the control group (152.8 ± 144.9, P =.002). Conclusions: We demonstrated that the augmentation of a hamstring tendon graft with the EndoPearl device increases interference screw fixation strength significantly. Under dynamic loading conditions, specimens of the study group sustained substantially higher loads and a larger number of cycles, which indicates a greater resistance to graft slippage. The application of the EndoPearl device may also allow for a secure soft-tissue graft fixation with interference screws in cases of critical fixation conditions.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 17, No 4 (April), 2001: pp 353–359     

Correlation of bone tunnel diameter with quadrupled hamstring graft fixation strength using a biodegradable interference screw

Purpose: The purpose of this study was to determine whether the ultimate load at failure of a quadrupled hamstring tendon graft (QHT) fixed with a biodegradable interference screw is improved with a more precise match of the bone tunnel diameter to the diameter of the QHT. Type of Study: Biomechanical testing. Methods: In group A, 8 cadaver knees with a mean age of 69.4 years (range, 60 to 76) were used. QHT graft diameters were measured using sleeves in standard 1.0-mm increments, with matching bone tunnels drilled in 1.0-mm increments. In group B, 9 cadaver knees, with a mean age of 66.5 (53 to 81) were used. Grafts were measured using sleeves in 0.5-mm increments and matching bone tunnels in 0.5-mm increments were drilled. In both groups, the QHT grafts were fixed with a biodegradable interference screw (BioScrew, Linvatec, Largo, FL) in both the tibia and the femur. Tendon interference fixation was tested to failure using a material testing device that tensioned the grafts directly in line with the bone tunnels. Bone mineral density was measured using dual photon absorptimetry for the metaphyseal area of the tibias and femora in the area of interference screw fixation. Results: Femoral maximum load at failure significantly improved from 341 N in the 1.0-mm group to 530 N (P <.05) in the 0.5-mm group; the tibial maximum load at failure improved from 221 N to 308 N (P =.35). Conclusions: Fixation strength results of this study suggest that commercially available instrumentation could be improved with sleeves and reamers available in 0.5-mm increments.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 18, No 8 (October), 2002: pp 901–907     

Arthroscopic single-bundle reconstruction of posterior cruciate ligament with quadrupled hamstring tendon

Objective： To evaluate the technique and outcome of arthroscopic sipy, le-bundie reconstruction of posterior crudate ligament （PCL） with quadrupled hamstring tendon. Methods： From April 2001 to October 2004, 49 knees with PCL tears in 49 patients were verified with arthroscope in this department. Of them, 13 were combined with anterior cruciate ligament tears, 14 with disruptions of the posterolateral comer, 6 with ruptures of the posteromedial corner and medial collateral ligament, 9 with lateral meniscus tears, 5 with medial meniscus tears and 2 with popliteal vascular tears. All the damaged PCLs were reconstructed with single-bundie of autogenous quadrupled hamstring tendons under arthroscope. Biodegradable interference screws or blunt titanium interference screws were used for direct anatomic fixation of the reconstructed ligament. Results： After operation, no severe complications occurred at early stage in the 49 patients. All of them were followed up for 10-52 months with an average of 22. 0 months ＋ 10. 7 months. Lysholm score was remarkably improved from 30-60 （ mean： 47.96 ＋ 8. 16） preoperatively to 70-95 （ mean： 89. 08 ＋ 6. 10 ） at the last postoperative follow-up （ P 〈 0.01 ）. Furthermore, there was a significant improvement in International Knee Documentation Committee （IKDC） score from abnormal （ Grade C） in 10 knees and severely abnormal （Grade D ） in 39 preoperatively to normal （ Grade A ） in 20, nearly normal （ Grade B） in 24 and abnormal in 5 at the last follow-up. Of the 49 patients, 40 returned to the same activity level as before and 9 were under the level. Conclusions： Single-bundle reconstruction of PCL with quadrupled hamstring tendons has the advantage of minimal trauma in surgery and satisfactory outcome.     

The effect of strand configuration on the tensile properties of quadrupled tendon grafts

Purpose: To compare selected biomechanical properties of 4 different quadrupled tendon graft preparations applicable for anterior cruciate ligament reconstruction. Type of Study: Biomechanical investigation in a cadaver model. Methods: Graft strands were arranged in parallel, braided, bolo-plait, and twist configurations. Elongation of the graft was monitored during loading with an infrared optical measurement system, which measured the 3-dimensional position of twelve spherical reflective markers mounted within the camera field. Permanent elongation, stiffness, and ultimate strength of each graft configuration were determined. Results: Permanent graft strain after the first incremental loading cycle was 7.2% in braid, 6.6% in twist, 6.5% in bolo-plait, and 3.3% in parallel constructs (P <.0001). Permanent graft strain after a second incremental loading cycle was 1.2% in bolo-plait, 1.1% in braid, 0.7% in twist, and 0.7% in parallel preparations (P =.0012). Braid and bolo-plait grafts were less stiff than twist or parallel grafts (P <.0001). Differences in failure load were not significant (P =.171). Conclusions: Variation in graft configuration from the conventional, parallel strand pattern lead to increased viscoelasticity and permanent elongation of grafts with repetitive loading. This deficit is expected to cause increased laxity of the reconstructed knee.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 18, No 2 (February), 2002: pp 194–200     

Anterior cruciate ligament reconstruction using hamstring tendon grafts

The annual incidence of more than 100,000 anterior cruciate ligament tears has increased with the rise of participation in sports in the general population, especially in females and older participants. Anterior cruciate ligament reconstruction is the standard of care in the young and/or athletically active individuals, based on prospective randomized studies. Replacement tissues to reconstruct the anterior cruciate ligament can be categorized as autograft, allograft, xenograft, and artificial replacements. Historically, xenograft and artificial replacements for the anterior cruciate ligament have failed dismally. As a result, autograft and allograft tissues commonly are used to reconstruct the anterior cruciate ligament. Autograft tissue currently is the most common source for grafts used worldwide. The two most common autograft tissues are the bone-patellar tendon-bone and hamstrings tendons. Controversy exists regarding the advantages and disadvantages of using each of these two tissues. The purpose of the current study was to review the basic science and clinical data regarding the use of the hamstring tendons in anterior cruciate ligament reconstruction.     

A modified technique for tibial interference screw fixation of hamstring anterior cruciate ligament grafts.

This article describes a modified technique for tibial fixation of quadrupled hamstring grafts in anterior cruciate ligament reconstruction. Using this technique common problems with tibial interference screw fixation of hamstring grafts-such as loss of tension of the graft during screw introduction or twisting of the graft in the tunnel around the screw-are avoided.     

Initial fixation strength of modified patellar tendon grafts for anatomic fixation in anterior cruciate ligament reconstruction.

Recently it has been shown that anatomic tibial graft fixation in anterior cruciate ligament (ACL) reconstruction is preferable in order to increase isometry and knee stability. To facilitate anatomic patellar tendon graft fixation, customized graft length shortening is necessary. The purpose of this study was to compare the initial fixation strength of four different shortened patellar tendon grafts including three bone plug flip techniques and direct patellar tendon-to-bone interference fit fixation in a model with standardized bone density. Ninety calf tibial plateaus (22 to 24 weeks old) with adjacent patella and extensor ligaments were used. Tendon grafts were shortened by flipping the bone plug over the tendon leaving a tendon-tendon-bone (TTB) construct and, as the first modification in the opposite direction resulting in a tendon-bone-tendon (TBT) construct. The second modification consisted of the TBT construct with interference screw position at the lateral aspect of the bone plug (TBTlat). As the fourth modification the tendon graft was directly fixed (Tdirect) with an interference screw. In addition, a round-threaded titanium (RCI; Smith & Nephew DonJoy, Carlsbad, CA), a round-threaded biodegradable screw (Sysorb; Sulzer Orthopedics, Münsingen, Switzerland), and a conventional titanium interference screw (Arthrex Inc, Naples, FL) were compared. We found that TTB (mean 441 N for biodegradable screw, 357 N for RCI screw, 384 N for conventional screw) and TBT (mean 407 N for biodegradable screw, 204 N for RCI screw, 392 N for conventional screw) construct fixation achieves comparable fixation strength, although failure in the TTB was due to tendon strip off at its ligamentous insertion. The highest failure load was found in TBTlat fixation (mean 610 N for biodegradable screw, 479 N for RCI screw). Therefore, this technique should be recommended when using a tendon flip technique. The failure load for Tdirect fixation (mean 437 N for biodegradable screw, 364 N for RCI screw) was similar to that of TTB and TBT fixation, which may indicate that a patellar-tendon graft harvested without its patellar bone plug and directly fixed with an interference screw is equivalent to a flipped graft. This may additionally reduce harvest site morbidity and eliminates the risk of patellar fracture. The fixation strength of round-threaded biodegradable and conventional titanium interference screws was similar, whereas that of round-threaded titanium screws was significantly lower in the patellar tendon flip-techniques. However, it should be taken into consideration that round-threaded titanium screws are proposed for direct tendon-to-bone fixation.     

The strength of distal fixation of flexor digitorum profundus tendon grafts in human cadavers

Early active motion limits adhesion formation and thus improves functional performance after tendon grafting. The early strength of distal fixation is critical to successful tendon grafting. We describe a new Y-tunnel technique of distal fixation and compare it with 2 established methods, the Pulvertaft transverse tunnel and the Bunnell button over the fingernail techniques, in a human cadaver model to determine which is the strongest method. Hands with a grafted tendon were rigidly mounted on an anatomic tensiometer testing apparatus and loaded to failure. Mean load to failure (newtons +/- 95% confidence intervals) of the Y-tunnel technique (155.2 +/- 29.4) was greater than those for the Pulvertaft (100.2 +/- 13.2) and Bunnell (57.1 +/- 4.7) techniques. Two-way analysis of variance showed significant differences, and the Bonferroni multiple pairwise comparison test showed that all 3 intergroup comparisons were statistically significant. These results indicate marked improvement in immediate strength with the Y-tunnel technique and lay the groundwork for further studies using a healing tendon model.     

In vitro comparison of tension and stiffness between hamstring tendon and patella tendon grafts

Following anterior cruciate ligament reconstruction, grafts relax and warm from the temperature of the operating room to body temperature. The current study compared graft tension and stiffness between patella tendon and hamstring tendon grafts. Six quadruple strand hamstring tendon grafts and six patella tendon grafts were preconditioned and loaded to 105 N while at 20°C. Graft tension and stiffness were measured after 15 min, after an additional 4 h, and after increasing the temperature to 34°C. A two‐way repeated‐measures analysis of variance and a post hoc test were used to compare the measurements between the two types of graft and identify significant (p < 0.05) changes for each type of graft. Tension was significantly larger for the patella tendon grafts, although the stiffness values were not significantly different (p > 0.8). For both types of graft, tension and stiffness decreased significantly with time and the temperature increase. The lowest tension and stiffness measurements were 50 ± 11 N and 129 ± 35 N/mm, respectively, for the patella tendon grafts, compared to 18 ± 5 N and 115 ± 11 N/mm, respectively, for the hamstring tendon grafts. Both types of graft lose tension to relaxation and a temperature increase, but the tension loss is larger for hamstring tendon grafts. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:1506–1511, 2008     

LARS中空韧带复合自体腘绳肌腱重建前交叉韧带手术技术

[目的]介绍LARS中空韧带复合自体腘绳肌腱重建前交叉韧带的手术技术和初步临床疗效。[方法]2018年8月~2019年1月,本院手术治疗前交叉韧带损伤患者18例,其中男11例,女7例,平均年龄(34.30±3.80)岁。切取半腱肌腱和股薄肌腱,折成四股编织缝合,再将其置入中空LARS人工韧带内编织缝合,制备直径8~9 mm的移植物,解剖位单束重建前交叉韧带。采用VAS评分、Lachman试验、Lysholm评分及IKDC评分评价临床效果。[结果] 18例均获随访,平均随访(4.20±1.90)个月。术后VAS评分、膝关节Lysholm评分及IKDC评分均较术前显著改善,临床结果评定优16例,良2例。[结论] LARS中空韧带联合自体腘绳肌腱重建前交叉韧带可快速恢复膝关节稳定性与功能,能较快地使患者重返生活及运动。     

A comparison of autogenous patellar tendon and hamstring tendon grafts for anterior cruciate ligament reconstruction

Several graft options exist for reconstruction of the deficient ACL. The most commonly used grafts are the BPTB and quadrupled hamstring tendon autografts. Based on a comprehensive review of the literature, one graft is not superior to the other. Advantages and disadvantages are associated with the use of each graft. Surgeons who perform ACL reconstruction should be familiar with the use of both grafts.     

Acromioclavicular reconstructions with hamstring tendon grafts: a comparative biomechanical study

The surgical treatment of chronic acromioclavicular injuries remains controversial. There is increasing use of autogenous tendon grafts to perform these reconstructions. This study examined the mechanical properties of differing configurations of these grafts. Mechanical testing of acromioclavicular joint reconstructions was performed with a screw and soft tissue washer for tendon fixation, a simple loop of tendon tied to itself, and a bio-interference screw for tendon fixation, with and without a loop of nonabsorbable suture for reinforcement. The bio-interference screw fixation, with reinforcement by a loop of nonabsorbable suture, gave the highest load to failure among the group (502N +/- 177), which was not significantly different from the intact ligaments (705 N +/- 132), although it was significantly less stiff than the intact group (57.2 N/mm +/- 12.6 and 109.7 N/mm +/- 32.6, respectively). All other reconstructions had an ultimate load and stiffness which were significantly less than that of the intact specimens.     

Stiffness characteristics of hamstring tendon graft fixation methods at the femoral site

In ACL reconstruction, stiffness and strength of a tendon graft complex are important features for knee stability and rehabilitation. The fixation between tendon and bone is known to be one of the weakest components of the graft complex. We examined the tensile load-displacement characteristics of looped semitendinosus tendons in a porcine femoral tunnel. Two groups of six cadaveric semitendinosus tendons and porcine femurs were tested, secured with either an aperture or non-aperture fixation method. Constructs were tested at 1 mm/s until failure in a materials testing machine, which allowed force and displacement data to be recorded. The non-aperture fixation group was significantly less stiff for the first 4 mm of displacement and had significantly higher ultimate failure loads. Provided that adequate ultimate strength can be achieved, stiffness properties of a tendon graft will be improved by using aperture fixation in femoral-site ACL reconstruction.

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Résumé Dans la reconstruction du LCA la rigidité et la résistance du complexe greffe-tendon sont des éléments importants pour la stabilité du genou et la récupération fonctionnelle. La fixation entre le tendon et los est connue pour être un des maillons faibles de lensemble. Nous avons examiné les caractéristiques de lélasticité sous traction de tendons du demi-tendineux insérés en boucle dans un tunnel fémoral porcin. Deux groupes de six tendons cadavériques ont été testés, amarrés par une fixation avec ou sans ouverture. Les constructions ont été testées à 1 mm/s jusquà la rupture avec une machine á traction qui permet denregistrer la force et le déplacement. Le groupe avec la fixation sans ouverture était significativement moins rigide pour les premiers 4 mm de déplacement et avait une charge de rupture nettement plus haute. A condition que la tension de rupture puisse être atteinte, les propriétés de rigidité dune greffe tendineuse seront améliorées en utilisant la fixation avec ouverture au niveau du site fémoral dans la reconstruction du LCA.

     

Tensile strength of a new suture for fixation of tendon grafts when using a weave technique

PURPOSE: To evaluate a new corner stitch construct for tendon graft or tendon transfer fixation and compare the tensile strength with a conventional central cross-suture design in human cadaver tendons. METHODS: Flexor digitorum profundus tendons of the index, middle, and ring fingers (48 total) were used as recipients and palmaris longus, extensor indicis proprius, and extensor digitorum communis tendons of the index finger (48 total) were used as grafts from 16 fresh-frozen human cadaver hands. We compared the cross-stitch technique with a new corner stitch technique in tendon repairs made with 1, 2, or 3 weaves (8 per group). Tendons were sutured at each weave with either 2 full-thickness cross-stitches or 4 partial-thickness corner stitches of 4-0 nylon. Mattress sutures also were placed through the free tendon end for each repair type. The tensile strength of the tendon-graft composite was measured with a materials testing machine. RESULTS: The tensile strength of the repairs increased significantly with the number of weaves. When 2 or 3 weaves were used with the corner stitch or when 3 weaves were used with the cross-stitch, the repairs were significantly stronger. Although no significant difference in strength to failure was noted when comparing cross and corner stitches with equivalent numbers of weaves, qualitatively there was a difference in mode of failure with the 3-weave corner stitches failing primarily by intrasubstance tendon failure and the 3-weave cross-stitch repairs failing by tendon pullout. CONCLUSIONS: The corner stitch is as strong as conventional cross-stitch repairs and its superficial placement may be more favorable to tendon blood supply. This repair may be advantageous for clinical applications.     

Revision anterior cruciate ligament reconstruction with ipsi- or contralateral hamstring tendon grafts

Objectives

With the increasing number of primary anterior cruciate ligament (ACL) reconstructions, the need for revision ACL surgery has risen over the past few years. The purpose of the present study is to retrospectively compare the clinical outcome of ipsilateral versus contralateral hamstring tendon autografts for ACL revision surgery, specifically with regard to patient satisfaction, post-operative functional outcomes, and return to sports.

Methods

Between 2004 and 2011, 64 patients underwent ACL revision surgery. Forty-five were successfully recontacted and retrospectively reviewed at an average follow-up of 6.3 years. Twenty-two subjects underwent revision ACL reconstruction with ipsilateral autogenous hamstring tendon grafts; in 23 subjects contralateral hamstring were used for reconstruction. Clinical, arthrometric, and functional evaluations were performed. The Tegner activity level, Knee Injury and Osteoarthritis Outcome Score (KOOS), and International Knee Documentation Committee (IKDC) Subjective Knee Form were used. Objective evaluation included range of motion, Lachman test, pivot shift test and KT-1000 instrumented laxity testing.

Results

No major complications were reported. Follow-up examination showed that there were no significant differences in the IKDC and KOOS scores between the groups. No differences in anterior tibial translation as measured with KT-1000 arthrometer were reported between the groups, although there was a trend for more of the patients undergoing ipsilateral DGST reconstruction to have a glide on the pivot shift test. The percentage of patients returning to pre-injury level was high in both groups.

Conclusions

The use of contralateral hamstring tendon autografts for ACL revision surgery produced similar subjective and objective outcomes at 6-years follow-up compared to revision with ipsilateral hamstring tendon autografts. Patients undergoing revision surgery with contralateral autografts experienced a quicker return to sports compared to patients who underwent ipsilateral DGST revision surgery.

     

Reconstruction of the superior peroneal retinaculum using a hamstring tendon autograft and interference screw

We present a new technique for reconstruction of the superior peroneal retinaculum in chronic dislocation of the peroneal tendons. This uses an autologous hamstring graft and an interference screw providing a low profile, secure fixation in the os calcis. This aims to restore normal anatomy without significant donor site morbidity.     

Graft fixation influences revision risk after ACL reconstruction with hamstring tendon autografts

Background and purpose — A large number of fixation methods of hamstring tendon autograft (HT) are available for anterior cruciate ligament reconstruction (ACLR). Some studies report an association between fixation method and the risk of revision ACLR. We compared the risk of revision of various femoral and tibial fixation methods used for HT in Scandinavia 2004–2011.

Materials and methods — A register-based study of 38,666 patients undergoing primary ACLRs with HT, with 1,042 revision ACLRs. The overall median follow-up time was 2.8 (0–8) years. Fixation devices used in a small number of patients were grouped according to design and the point of fixation.

Results — The most common fixation methods were Endobutton (36%) and Rigidfix (31%) in the femur; and interference screw (48%) and Intrafix (34%) in the tibia. In a multivariable Cox regression model, the transfemoral fixations Rigidfix and Transfix had a lower risk of revision (HR 0.7 [95% CI 0.6–0.8] and 0.7 [CI 0.6–0.9] respectively) compared with Endobutton. In the tibia the retro interference screw had a higher risk of revision (HR 1.9 [CI 1.3–2.9]) compared with an interference screw.

Interpretation — The choice of graft fixation influences the risk of revision after primary ACLR with hamstring tendon autograft.     

Biomechanical testing of hamstring graft tibial tunnel fixation with bioabsorbable interference screws

Purpose:This study evaluated the failure mode, maximum load at failure, displacement at failure, and stiffness differences of quadrupled hamstring graft-tibial tunnel fixation using 28-mm, tapered 35-mm, or bicortical 17- and 20-mm bioabsorbable interference screws (Arthrex, Naples, FL).Type of Study:Biomechanical study.Methods:Nine matched pairs (18 specimens) of young cadaver tibias (mean bone mineral density [BMD] = 0.847 g/cm², range, 0.689 to 1.11 g/cm²) were divided into 3 groups of 6 specimens. Kruskal Wallis analysis of variance and Mann-Whitney U tests post hoc comparisons were used to assess group differences (P < .05).Results:Maximum load at failure for the 28-mm screw was 488.2 ± 197 N, with a displacement of 18.4 ± 7.5 mm and a stiffness modulus of 38.9 ± 7.0 N/mm. Maximum load at failure for the tapered 35-mm screw was 844.8 ± 121.4 N, with a displacement of 15.3 ± 1.6 mm and a stiffness modulus of 70.5 ± 21.1 N/mm. Maximum load at failure for bicortical screw fixation was 543.7 ± 266.5 N, with a displacement of 17.7 ± 6.6 mm and a stiffness modulus of 57.7 ± 14.9 N/mm. Fixation using the tapered 35-mm screw displayed greater maximum load at failure than either 28-mm screw fixation (P = .015) or bicortical screw fixation (P = .037). Significant differences were not evident for displacement. Both tapered 35-mm (P = .016) and bicortical screw (P = .026) fixation displayed greater stiffness than 28-mm screw fixation. All constructs failed by pullout.Conclusions:Fixation using a single tapered 35-mm screw displayed increased maximum load at failure compared with the 28-mm screw or bicortical fixation. Both the tapered 35-mm screw and bicortical fixation showed greater stiffness than fixation using a 28-mm screw. Use of a single 35-mm screw for quadrupled hamstring graft-tibial tunnel fixation may be preferred for patients with poor tibial BMD.