Hamstring autograft utilization in reconstructing anterior cruciate ligament: Review of harvesting techniques,graft preparation,and different fixation methods

Rupture of the anterior cruciate ligament (ACL) is a common orthopedic injury. Various graft options are available for the reconstruction of ruptured ACL. Using the hamstring muscle as an autograft was first described in 1934, and it remains a commonly harvested graft for ACL reconstruction. Hamstring autografts can be harvested using the traditional anteromedial approach or the newer posteromedial technique. An isolated semitendinosus tendon can be used or combined with the gracilis tendon. There are numerous methods for graft fixation, such as intra-tunnel or extra-tunnel fixation. This comprehensive review discusses the different hamstring muscle harvesting techniques and graft preparation options and fixation methods. It provides a comprehensive overview for choosing the optimal surgical technique when treating patients.     

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.     

Editorial Commentary: How to Increase Hamstring Tendon Graft Size for Anterior Cruciate Ligament Reconstruction

The concept of a five-strand hamstring tendon autograft for anterior cruciate ligament reconstruction is not new. The concept of a five-strand hamstring tendon autograft was largely ignored until recent studies showed higher failure and revision rates for hamstring ACL reconstructions performed with graft diameters less than 8 mm. In the majority of patients in the United Arab Emirates, four-strand hamstring tendon autografts result in a graft diameter between 6.5-7.5 mm. As a result, since 2006, I have completely abandoned using four-strand hamstring tendon autografts in favor of five-and six-stranded hamstring tendon autografts for ACL reconstructions. The key to performing five-or six-strand hamstring tendon autografts lies in the ability to triple the semitendinosus tendon and in the case of six-strand hamstring tendon grafts, the gracilis tendon. Although, five-and six-strand hamstring tendon autografts can increase the diameter of hamstring tendon ACL grafts, the question of whether these grafts will reduce failure and revision rates remains unanswered.     

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.     

Prediction of hamstring tendon autograft diameter and length for anterior cruciate ligament reconstruction

The purpose of this study was to determine whether common physical measurements in patients undergoing anterior cruciate ligament (ACL) reconstruction with autologous hamstring tendon could be used to predict autograft length and diameter. One hundred nineteen consecutive patients undergoing hamstring autograft ACL reconstruction had these preoperative measurements taken: age, height, weight, bilateral leg length, and bilateral thigh girth 5 and 10 cm proximal to the superior pole of the patella. Correlations between these measurements and graft length and diameter were evaluated. There was a strong correlation between leg length and hamstring autograft length (r = .73, P<.001). Weight (r = .51, P<.001) and leg length (r = .42, P<.001) had only moderate correlations with graft diameter. All other correlations were weak. Regression analysis demonstrated that leg length can be used to predict hamstring autograft tendon length to within 20 mm and that weight can be used to predict graft diameter to within 1.2 mm using regression equations. In conclusion, several simple measurements correlate with doubled semitendinosus and gracilis tendon autograft length and diameter. This new information may prove useful to surgeons who want hamstring autografts of a certain diameter or of a long length.     

Hamstring tendon anterior cruciate ligament reconstruction: does gracilis tendon harvest matter?

Purpose

Hamstring tendon grafts are a popular choice for anterior cruciate ligament (ACL) reconstruction. Typical morbidity reported after hamstring tendon harvest is muscle weakness in flexion, and whilst still a matter for debate, this morbidity may be greater if the gracilis tendon is harvested in addition to the semitendinosus. This study sought to comprehensively compare the outcome of ACL reconstructions in which the semitendinosus was harvested alone (ST group) or with the gracilis (ST/G group).

Methods

Twenty patients (ten ST, ten ST/G) were assessed with a variety of measures that included subjective scores, function, strength and tibial rotation as measured by gait analysis during a pivoting task.

Results

Results showed that the graft diameter was significantly larger in the ST group, but there were no other differences between the groups for any other outcome measure.

Conclusion

Harvesting the gracilis in addition to semitendinosus does not appear to affect either the outcome or graft-related morbidity after hamstring ACL reconstruction.     

Joint Infection Unique to Hamstring Tendon Harvester Used During Anterior Cruciate Ligament Reconstruction Surgery

Joint infection after anterior cruciate ligament (ACL) reconstruction is a rare but important clinical issue that must be resolved quickly to prevent secondary joint damage and preserve the graft. After careful analysis, we observed 3 infection cases within a 12-month period after ACL reconstruction, which represented an abnormally elevated risk. All reconstructions were performed by the same surgeon and used hamstring tendon allograft. For each surgery, the Target Tendon Harvester (DePuy Mitek, Raynham, MA) was used to harvest hamstring tendons. Through our review, we learned that this instrument was sterilized while assembled. It is our belief that ineffective sterilization of this hamstring graft harvester served as the origin for these infections. We have determined that appropriate sterilization technique involves disassembly of this particular hamstring tendon harvester before sterilization because of the tube-within-a-tube configuration. We have since continued to use the Target Tendon Harvester, disassembling it before sterilization. There have been no infections in the ensuing 12 months during which the surgeon performed over 40 primary ACL reconstructions via hamstring autograft. The information from this report is intended to provide arthroscopists with information about potential sources of infection after ACL reconstruction surgery.     

Prospective clinical comparisons of semitendinosus versus semitendinosus and gracilis tendon autografts for anatomic double-bundle anterior cruciate ligament reconstruction

Background

The data available from the previously reported clinical studies remains insufficient concerning the hamstring graft preparation in double-bundle anterior cruciate ligament (ACL) reconstruction.

Objective

To test the hypothesis that there are no significant differences between the semitendinosus tendon alone and the semitendinosus and gracilis tendon graft fashioning techniques concerning knee stability and clinical outcome after anatomic double-bundle ACL reconstruction.

Methods

A prospective study was performed on 120 patients who underwent anatomic double-bundle ACL reconstruction according to the graft fashioning technique. The authors developed the protocol to use hamstring tendon autografts. When the harvested doubled semitendinosus tendon is thicker than 6 mm, each half of the semitendinosus tendon is doubled and used for the anteromedial (AM) and posterolateral (PL) bundle grafts (Group I). On the other hand, when the harvested semitendinosus tendon is under 6 mm in thickness, the gracilis tendon is harvested additionally. The distal half of the semitendinosus and gracilis tendons are doubled and used for the AM bundle graft, and the remaining proximal half of the semitendinosus tendon is doubled and used for the PL bundle grafts (Group II). Sixty-one patients were included in Group I, and 59 patients in Group II. The two groups were compared concerning knee stability and clinical outcome 2 years after surgery.

Results

The postoperative side-to-side anterior laxity averaged 1.3 mm in both groups, showing no statistical difference. There were also no significant differences between the two groups concerning the peak isokinetic torque of the quadriceps and the hamstrings, the Lysholm knee score, and the International Knee Documentation Committee evaluation.

Conclusion

There were no significant differences between the two graft fashioning techniques after anatomic double-bundle ACL reconstruction concerning knee stability and postoperative outcome. The present study provided orthopedic surgeons with important information on double-bundle ACL reconstruction with hamstring tendons.

Level of evidence

Level II; prospective comparative study.     

Donor-site morbidity and anterior knee problems after anterior cruciate ligament reconstruction using autografts

The authors review the current knowledge on donor site–related problems after using different types of autografts for anterior cruciate ligament (ACL) reconstruction and make recommendations on minimizing late donor-site problems. Postoperative donor-site morbidity and anterior knee pain following ACL surgery may result in substantial impairment for patients. The selection of graft, surgical technique, and rehabilitation program can affect the severity of pain that patients experience. The loss or disturbance of anterior sensitivity caused by intraoperative injury to the infrapatellar nerve(s) in conjunction with patellar tendon harvest is correlated with donor-site discomfort and an inability to kneel and knee-walk. The patellar tendon at the donor site has significant clinical, radiographic, and histologic abnormalities 2 years after harvest of its central third. Donor-site discomfort correlates poorly with radiographic and histologic findings after the use of patellar tendon autografts. The use of hamstring tendon autografts appears to cause less postoperative donor-site morbidity and anterior knee problems than the use of patellar tendon autografts. There also appears to be a regrowth of the hamstring tendons within 2 years of the harvesting procedure. There is little known about the effect on the donor site of harvesting fascia lata and quadriceps tendon autografts. Efforts should be made to spare the infrapatellar nerve(s) during ACL reconstruction using patellar tendon autografts. Reharvesting the patellar tendon cannot be recommended due to significant clinical, radiographic, and histologic abnormalities 2 years after harvesting its central third. It is important to regain full range of motion and strength after the use of any type of autograft to avoid future anterior knee problems. If randomized controlled trials show that the long-term laxity measurements following ACL reconstruction using hamstring tendon autografts are equal to those of patellar tendon autografts, we recommend the use of hamstring tendon autografts because there are fewer donor-site problems.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 17, No 9 (November-December), 2001: pp 971–980     

无内固定物腘绳肌腱重建前交叉韧带临床探讨

目的探讨用无内固定物的绳肌腱重建前交叉韧带的临床运用和效果。方法自2002年12月～2004年6月对33例前交叉韧带损伤进行了无内固定物的绳肌腱重建前交叉韧带术,其中13例移植肌腱采用二股半腱肌腱和二股股薄肌腱,另20例仅为二股半腱肌腱,术前和术后进行Lachman试验评估膝关节的稳定性,用Lysholm评分方法评定膝关节功能。结果术前Lachman试验均为阳性,术后29例为阴性,4例为阳性。术前Lysholm评分为36～57分,术后Lysholm评分为71～96分。结论无内固定物的绳肌腱重建前交叉韧带为生物固定,固定可靠、费用少、短期效果好,中长期效果有待观察。     

Magnetic resonance imaging at different time periods following hamstring harvest for anterior cruciate ligament reconstruction

Purpose: The purpose of this study was to evaluate the magnetic resonance imaging (MRI) appearance of the hamstring graft harvest site after harvesting the hamstring tendons to reconstruct a torn anterior cruciate ligament (ACL). Type of Study: Case series. Methods: We performed MRI on 21 patients who had previously undergone hamstring harvest and ACL reconstruction. Twenty of the patients (7 female and 13 male; mean age, 37 years; range, 16 to 84 years), all volunteers, were selected from a series of 45 ACL reconstructions performed by the senior author during a 20-month period. Another patient, a 32-year-old man, underwent ACL reconstruction elsewhere 32 months before. Both the semitendinosus and gracilis tendons were harvested in all cases. All MRIs were obtained on a 1.5-T magnet and were prospectively evaluated by 2 experienced musculoskeletal radiologists who were blinded to the time interval between graft harvest and MRI. Results: Two weeks after graft harvest, MRI showed ill-defined intermediate signal on T1-weighted images and increased signal on T2-weighted images, consistent with fluid in the harvest site, with no discernable tendon. At 6 weeks, structures were seen at the level of the superior pole of the patella that had morphology and signal characteristics similar to native tendon. By 3 months, structures with normal morphology and signal characteristics were seen to the level of the joint line, and by 12 months, to the level of 1 to 3 cm above that of the tibial attachment. At 32 months, the tendons appeared on MRI to normalize to a level of 1 to 2 cm above their tibial attachment. Conclusion: Following hamstring tendon harvest, MRI demonstrates an apparent regeneration of tendons beginning proximally and extending distally over time.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 17, No 1 (January), 2001: pp 2–8     

兔自体半腱肌重建前交叉韧带拉伸断裂后组织学研究

目的观察骨形态发生蛋白(BMP)复合异体脱蛋白松质骨(DPB)行自体双股半腱肌肌腱重建前交叉韧带(ACL)术后移植物断裂部位及组织学形态。方法将64只骨骼成熟新西兰大白兔分成四组,其中一组为空白对照组,其他三组选取每只兔的左侧膝关节进行手术,术中于骨隧道内植入BMP结合DPB、BMP、DPB。分别于术后第3、6、12、24周取材,保留股骨下段及胫腓骨上段,包埋后行移植物抗拉测试,观察移植物完全断裂部位及断面组织学结构,采用苏木精-伊红染色观察其变化过程。结果术后第3周,移植物断裂部位DPB组及空白对照组位于股骨隧道内,断端仅为纤维组织,BMP组及BMP结合DPB组均位于隧道内口,断端可见少量软骨样组织。术后12周各组移植物断裂部位均位于关节腔内,断端均可见大量胶原纤维,空白对照组及DPB组胶原纤维排列不规则,BMP组及BMP结合DPB组胶原纤维较规则,纤维软骨细胞增多。术后第24周各组断裂部位位于关节腔内移植物中段或近止点处,BMP结合DPB组及BMP组断端胶原纤维排列整齐、规则,可见短杆状及椭圆形细胞,空白对照组及DPB组仅见胶原纤维排列较前规则,未见软骨细胞。结论术后第24周BMP结合DPB组较其他各组更早发生爬行替代,在组织学形态上与正常前交叉韧带更相似。     

Muscle and tendon morphology after reconstruction of the anterior cruciate ligament with autologous semitendinosus-gracilis graft

BACKGROUND: The autologous semitendinosus-gracilis graft is the first choice of many orthopaedic surgeons when reconstructing the anterior cruciate ligament. The effect that graft harvest has on muscle and tendon morphology remains unclear. The purpose of this study was to describe these effects more completely. METHODS: Magnetic resonance images were acquired from eight patients before the anterior cruciate ligament reconstruction with semitendinosus-gracilis autograft and then again postoperatively after they had returned to sports. Muscle and tendon morphology was described by determining the volume and peak cross-sectional area of each structure on digitally reconstructed images. The effects that the procedure had on muscle and tendon length were evaluated separately and then together as a muscle-tendon complex. RESULTS: Anterior cruciate ligament reconstruction with semitendinosus-gracilis autograft resulted in a marked decrease in volume, cross-sectional area, and length of the semitendinosus and gracilis muscles. Tendon regeneration occurred in varying degrees in nearly all subjects. The morphology of the biceps femoris and semimembranosus muscles suggested that they had been compensating for the reduced semitendinosus and gracilis muscle function. Although semitendinosus and gracilis muscle retraction occurred following tendon stripping, nearly all of the subjects displayed evidence of at least partial tendon regeneration. CONCLUSIONS: Anterior cruciate ligament reconstruction with semitendinosus-gracilis autograft had a marked impact on semitendinosus and gracilis muscle morphology. However, this altered muscle morphology did not appear to have a clinically important impact on short-term outcomes. The biceps femoris and semimembranosus muscles appear to compensate for reduced semitendinosus and gracilis function. Tendon regeneration is observed in most people, but it is often incomplete at six months.     

Evaluation of active knee flexion and hamstring strength after anterior cruciate ligament reconstruction using hamstring tendons

Purpose: The purpose of this study was to evaluate active knee flexion range of motion and hamstring strength following hamstring anterior cruciate ligament (ACL) reconstruction. Type of Study: Case control study, consecutive sample. Methods: Seventy-four consecutive patients who had undergone hamstring ACL reconstruction underwent isokinetic muscle strength testing at 2 years post surgery. Measurements of the maximum standing active knee flexion angle with the hip extended were also taken. During isokinetic testing, we evaluated flexion torque at 90° of knee flexion, in addition to the peak flexion torque. We further compared these parameters of muscle strength around the knee for the patients in whom only semitendinosus tendon was harvested as a graft source (ST group), and those from whom the semitendinosus tendon and the gracilis tendon were harvested (ST/G group). Results: Isokinetic testing showed that, in both the ST and ST/G groups, the knee flexor strength of the involved leg was less effectively restored at 90° of knee flexion than at the angle at which the peak torque was generated. Conversely, no significant difference was seen in the side-to-side ratio in either the peak flexion torque or the 90° flexion torque between the groups. The side-to-side ratio in mean maximum standing knee flexion angle was significantly lower in the ST/G group than in the ST group. Conclusions: This study suggests that the loss of knee flexor strength following the harvest of the hamstring tendons may be more significant than has been previously estimated. Furthermore, multiple tendon harvest may affect the range of active knee flexion.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 18, No 6 (July-August), 2002: pp 598–602     

Editorial Commentary: Revision Anterior Cruciate Ligament Using Soft Tissue Autograft Quadriceps Is Effective but Not Recommended for All Comers

The average revision rate is between 3.2% and 11.1%following primary anterior cruciate ligament (ACL) reconstructions,¹ and an objective failure rate of 13.7% has been reported for revision ACLR.² Prior implants, positioning of tunnels, and muscle weakness from the prior reconstruction present challenges. Additionally, graft choice for the revision reconstruction is restricted, depending on the primary reconstruction. Revision ACL reconstruction with the all-soft tissue quadriceps tendon autograft is a viable option with 83.3% of the patients surpassing the minimally clinically significant difference for International Knee Documentation Committee (IKDC) scores, which is similar to outcomes for revision ACL reconstruction (ACLR) using bone-patella-bone and hamstring tendon autografts. Furthermore, objective strength data suggest that it is possible to achieve equal limb symmetry index strength ratios even in the setting of prior bone-patella tendon-bone autograft. However, although I am cautiously optimistic regarding soft tissue quadriceps autograft in revision ACLR, I would be hesitant to recommend it for all comers. In my experience, young high school/collegiate female athletes with primary reconstruction using BPTB autograft may not be able to tolerate a secondary insult to the extensor mechanism via quadriceps tendon (QT) autograft harvest, where hematoma and arthrofibrosis could be concerns. Furthermore, increased posterior tibial slope may require evaluation and treatment, and the addition of a lateral extra-articular tenodesis may reduce residual rotatory laxity in ACL revision patients.     

Semitendinosus muscle in anterior cruciate ligament surgery: Morphology and function

Purpose: To evaluate the fate of the hamstring muscles in general and the semitendinosus muscle in particular, after anterior cruciate ligament (ACL) reconstruction with an autologous semitendinosus tendon graft from the ipsilateral side. Type of Study: Prospective consecutive case series investigation. Methods: Included were 16 consecutive patients, 14 male and 2 female, with a mean age of 26 years. The inclusion criterion was chronic unilateral ACL insufficiency with no concomitant knee ligament injuries. ACL reconstruction was performed with a quadruple semitendinosus tendon graft using the EndoButton technique (Acufex, Mansfield, MA). Intraoperatively, muscle specimens were taken from the semitendinosus muscle on the harvested side. Follow-up at a minimum of 6 months included clinical examination, isokinetic strength performance, magnetic resonance imaging (MRI) of the thigh and knee, and ultrasound-guided muscle biopsy procurement from the semitendinosus muscle for histochemical and enzymatic analyses. Results: Of the patients, 75% showed regeneration of their semitendinosus tendons. The neotendons all inserted below the knee joint where they had fused with the gracilis tendon to a conjoined tendon inserting in the pes anserinus. The semitendinosus muscle had a smaller cross-sectional area on the operated side but none showed total atrophy. Less atrophy was present in the patients with a regenerated semitendinosus neotendon compared with those without regeneration (P =.029). In the latter group the semimembranosus muscle seemed to compensate for this with hypertrophy (P =.019). Cross-sectional muscle fiber areas, the relative number of each fiber type and oxidative potential as estimated by citrate synthase activity, showed no significant differences between the operated and nonoperated legs. The isokinetic strength of the hamstrings and quadriceps was significantly lower in the operated leg than in the nonoperated leg. Conclusions: With this surgical technique, the semitendinosus muscle can recover and the tendon has, according to the MRI images, a great potential to regenerate after its removal.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 17, No 8 (October), 2001: pp 808–817     

Quadriceps Tendon Graft for Anterior Cruciate Ligament Reconstruction: THE GRAFT OF THE FUTURE!

Anterior cruciate ligament (ACL) reconstruction is one of the most common orthopaedic surgeries performed on active people in the world. One of the most important surgical decisions is graft type for use in the reconstruction. Despite extensive research on optimal graft choice for ACL reconstruction, discrepancy exists among practicing surgeons' graft preference. Recently, the quadriceps tendon has gained popularity for use as a graft source for ACL reconstruction.The all soft tissue quadriceps graft offers many advantages over other autograft choices. Histologically it has 20% more collagen fibrils per cross-sectional area than the patellar tendon (PT). Biomechanically, its ultimate load is 70% > than that of a similar width PT graft, while its modulus is more similar to the native ACL than either the PT or hamstring graft. Anatomically the quadriceps tendon has significantly more volume than the PT. Thus, even after harvest of the quadriceps graft, the remaining quadriceps tendon is still 80% stronger than the intact PT!The length and cross-sectional area of the quadriceps tendon graft can be tailored to the needs of the patient. On any patient over 5 feet tall, a graft length of 7 cm can be obtained. Because the thickness of the tendon is almost twice the thickness of the same patient's PT, a graft diameter from 7 to 11 mm can easily be achieved. Thus, this graft can be customized for both primary and revision surgeries.Harvest site morbidity is minimal. An incision less than 2 cm in an area with no significant cutaneous nerves without harvest of any patella bone leads to no significant harvest site pain, numbness, or palpable defect.Clinical outcomes using this graft are excellent. Our prospective data on nearly 1,000 grafts, with a mean patient age of 20 years old, show a 4.2% failure rate. Thus, the all soft tissue quadriceps graft will be the surgical choice for ACL reconstruction for future athletes.     

Initial biomechanical properties of anterior cruciate ligament reconstruction autografts

To provide more information to consider when selecting a reconstruction technique, we did a side-by-side comparison of some of the initial biomechanical properties of currently accepted reconstruction methods. Our research hypotheses were that a quadrupled, woven semitendinosus and gracilis graft is as strong as any of the other commonly used graft materials and that quadrupling and weaving the hamstring graft may increase the stiffness of the overall construct Using lower extremity cadaveric specimens harvested from young donors, we fashioned seven each of seven types of graft: 9-mm, 10-mm, and 11-mm-wide patellar tendon graft (PTG); 10-mm-wide central quadriceps tendon graft; doubled semitendinosus graft; tripled semitendinosus graft; and quadrupled, woven semitendinosus and gracilis graft. Specimens were stripped of remaining soft tissue, and anterior cruciate ligament (ACL) constructs were created for biomechanical testing. The tibia was translated anteriorly on the femur, mimicking a pivot shift maneuver, andfailure strength, failure mechanism, and construct stiffness were recorded. No differences in mean strength were detected. The quadrupled, woven graft was significantly stiffer than the doubled semitendinosus graft and no less stiff than any of the PTG constructs. All grafts showed similar and adequate initial absolute strength to reconstruct the ACL. Quadrupling and weaving the semitendinosus and gracilis graft increases the stiffness of the reconstructed specimen to a level statistically similar to that of specimens reconstructed with a PTG.     

Clinical outcomes after ACL reconstruction with free quadriceps tendon autograft versus hamstring tendons autograft. A retrospective study with a minimal follow-up two years

ObjectiveThe aim of this retrospective study was to compare the clinical outcomes of anatomic single bundle ACL reconstruction using either a free quadriceps tendon autograft or a quadrupled hamstring autograft with a minimum follow-up of 24 months.MethodsConsecutive patients undergoing ACL reconstruction using either a free quadriceps tendon autograft or hamstring tendon autograft from January 2013 to December 2014 were included. ACL reconstruction was done in all patients due to isolated ACL tears. Patients with associated cartilage lesions > Outerbridge III, meniscal lesions in need of meniscectomy or repair as well as patients with prior knee surgery on the affected or contralateral knee were excluded. The primary outcome evaluation was the side-to-side difference in instrumented Lachman testing. Secondary outcome evaluation consisted in the Lysholm, modified Cincinnati and SF-36 scores. Side-to-side difference in range of motion and thigh diameter was also documented.ResultsAfter applying the inclusion/exclusion criteria, a total of 82 patients were identified and 72 (87.8%) presented to the hospital for follow-up. There were 39 patients with quadriceps graft (30.64 ± 8.71, range: 18–53 years) and 33 patients with hamstrings (28.60 ± 6.74, range: 18–46 years). No statistically significant difference between groups was detected with regard to KT-1000 measurements (p = 0.326). No significant difference was found between the mean postoperative Lysholm (p = 0.299), the modified Cincinnati (p = 0.665) and the general SF-36 scores between groups (p = 0.588). Less side-to-side thigh diameter difference was noted in the quadriceps graft group (p = 0.026).ConclusionIn conclusion, similar clinical results, in terms of stability and subjective measures, can be obtained after ACL reconstruction both with a free quadriceps and a 4-strand hamstring tendons autograft.Level of evidenceLevel III, Therapeutic Study.