Implant-free press-fit fixation for bone–patellar tendon–bone ACL reconstruction: 10-year results

Objective

The aim of this study is to determine the outcome of anterior cruciate ligament (ACL) reconstruction without foreign material with patellar tendon bone graft in the fixation with bone dowels near the native insertion.

Materials and methods

Between 1998 and 1999, 189 patients were operated with ACL reconstruction with BTB patellar tendon graft. In a prospective study, 148 (78%) (91M, 57F) patients could be seen for a mean follow-up of 10.3 years. All had foreign material-free press-fit and a bottom-to-top (BTT) fixation in 120° knee flexion. All patients were evaluated with detailed history, clinical examinations, radiographic examination with weight bearing which could be compared to the time of surgery in 64 (43%) patients. Laxity testing was performed in Lachman position with the Rolimeter and pivot shift. All patients were graded according to the IKDC and Tegner activity score.

Results

87% of the patients achieved an IKDC score of A/B. The subjective IKDC score was A/B in 94.6% of the subjects. The average side-to-side difference was 1.42 ± 0.88 mm for the Lachman test, 97% of the patients were rated between 0 and 2 mm. The pivot-shift test was negative in 90% and was observed with a glide in 7% of the patients. Radiological joint space narrowing was found in the medial compartment in 8 (12.4%) cases, and laterally in 9 (14.1%) cases. All these patients had partial or total meniscus resections. The patello-femoral joint space was reduced in 21 (23%) cases. The Tegner activity score changed from 6.9 pre-injury to 5.0 at the 10-year follow-up.

Conclusion

The implant-free fixation of the graft with bone dowels and BTT implantation has good and excellent results after 10 years in more than 80% of the patients. Loss of the meniscus is a main factor contributing to osteoarthritis. Advantages of patellar tendon bone press-fit fixation include anatomical positioning and fast bone-to-bone healing, ease for revision surgery and cost effectiveness.     

Flipped patellar tendon autograft anterior cruciate ligament reconstruction.

To determine the efficacy of an anterior cruciate ligament (ACL) graft that customizes length and facilitates anatomic outlet fixation, a prospective study of the "flipped" patellar tendon autograft ACL reconstruction began in 1995. This technique shortens the tendon portion to match the intra-articular length by rotating 1 bone plug 180 degrees proximally onto the tendon, thus flipping the bone plug over its ligamentous insertion. Bioscrews (poly L-lactic acid; Linvatec, Largo, FL) secured the grafts. All patients undergoing this procedure with a minimum 21 months follow-up were reviewed. Preoperative and postoperative Tegner, Lysholm, and IKDC activity scores, and Lachman and pivot shift tests were obtained. Postoperative KT testing and radiographs were obtained. Fifty patients were followed-up for an average of 28 months (range, 21 to 39 months). Average patient age was 34 years (range, 16 to 52 years). Tegner scores increased from 2.0 preoperatively to 6.0 postoperatively. Lysholm scores increased from 46 preoperatively to 93 at follow-up, with 86% excellent (66%) or good (20%). IKDC activity scores increased from 3.1 preoperatively to 1.7 postoperatively. KT manual-maximum difference at follow-up averaged 0.7 mm, with 74% less than 3-mm, 18% 3- to 5-mm, and 8% greater than 5-mm difference. Postoperative Lachman results were 0 in 45 patients and 1+ in 5 patients. Postoperative pivot shift was absent in all but 1 patient. Full extension was achieved in all cases and flexion averaged 136 degrees with no patient having less than 120 degrees flexion. No lytic bone changes or tunnel widening were seen. The flipped patellar tendon autograft reduces graft length to its intra-articular portion, increasing graft stability, isometry, and stiffness, and avoiding tunnel graft mismatch with clinically excellent results.     

Arthroscopic posterior cruciate ligament reconstruction by using hamstring tendon autograft and transosseous screw fixation: minimal 3 years follow-up

Background

The aim of this trial is to prospectively evaluate the outcomes of PCL reconstruction by means of quadruple hamstring tendon autograft with a double-fixation method at minimal 3-year follow-up.

Materials and methods

Only patients who underwent PCL reconstruction without any other concomitant injury were included in this study. A hamstring tendon graft is composed of a quadruple-stranded gracilis tendon and semitendinosus tendon about 10 cm in length. An arthroscopic technique via a two incision and a double-fixation method was applied. Clinical evaluations were performed for 52 patients. Clinical assessment of patients included the Lysholm knee scores, International Knee Documentation Committee (IKDC) scores, thigh muscle evaluation, and radiographic investigation.

Results

On the Lysholm knee score, 90 % of the patients displayed good or excellent rating in the final assessment. In the IKDC rating analyses, 60 % of the patients demonstrated 3–5-mm ligament laxity. For the IKDC final rating, 81 % were normal or nearly normal. Seventy-nine percent of the cases revealed less than a 10-mm difference in thigh girth between their reconstructed and contra lateral limbs.

Conclusion

Arthroscopic PCL reconstruction using quadruple hamstring tendon autograft provides acceptable outcomes at a minimum 3-year follow-up. The four-stranded hamstring tendon graft is suitable in graft size and results in minimal harvesting morbidity. We recommend that quadruple hamstring tendon graft be chosen for PCL reconstruction to achieve good ligament reconstruction. A double-fixation method which has been applied in this trial can be used to provide rigid fixation.     

ACL reconstruction using bone–patella tendon–bone autograft: press-fit technique vs. interference screw fixation

Purpose

The gold standard in ACL reconstructions has been the bone–patellar tendon–bone autograft fixed with interference screws. This prospective, randomized clinical trial aimed to compare two methods of fixation for BPTB grafts: press-fit fixation vs. interference screw, over a 12-month follow-up interval.

Methods

158 patients with an average age of 29.8 years, between 2011 and 2012, were treated for torn ACL. 82 patients underwent reconstruction with BPTB autograft with a press fit fixation technique, and in 76 cases an interference screw was used. At the time of final follow-up, 71 patients in press-fit group and 65 patients in interference screw group were evaluated in terms of return to pre-injury activity level, pain, knee stability, range of motion, IKDC score and complications.

Results

At 12-month follow-up, 59 (83 %) and 55 (85 %) in press-fit and screw group, respectively had good-to-excellent IKDC score (p > 0.05). The mean laxity assessed using a KT-1000 arthrometer improved to 2.7 and 2.5 mm in press-fit and screw group, respectively. Regarding Lachman and pivot shift test, there was a statistically significant improvement in the integrity of the ACL in both the groups, but no significant differences was noted between groups. There were no significant differences in terms of femur circumference difference, effusion, knee range of motion, pain and complications.

Conclusions

The press-fit technique is an efficient procedure. Its outcome was comparable with the interference screw group. Furthermore it has unlimited bone-to-bone healing, no need for removal of hardware, ease for revision and cost effectiveness.     

Kniegelenklaxizität beim vorderen Kreuzbandersatz

Background

The use of interference screws for femoral graft fixation in anterior cruciate ligament (ACL) reconstruction with hamstring grafts can result in rotation of the graft around the screw leading to changes in the final position of the graft within the bone tunnel.

Material and methods

In a prospective study 107 patients (54 right and 53 left knees) underwent ACL reconstruction with a hamstring tendon autograft. Femoral fixation of the graft was performed with a standard right-thread screw in all cases. Patients were assessed at 6 months postoperatively with the international knee documentation committee (IKDC) standard evaluation including instrumented laxity measurements and the results were compared between right and left knees.

Results

A significantly higher postoperative anterior laxity was observed in left knees with a negative Lachman test in only 64 % of the cases compared with 87 % in the group of right knees. Accordingly, instrumented laxity measurements of the reconstructed knee compared with the contralateral knee revealed significant differences between left and right knees (left knees 1.8±1.2 mm and right knees 1.0±1.4 mm)

Conclusions

This study demonstrates the importance of femoral graft positioning and its sensitivity to multiple influencing factors. The use of standard right-thread interference screws for femoral graft fixation in the mirrored situation of right and left knees may produce a systematic error in ACL reconstruction. Due to a possible rotation of the graft around the screw, the final position of the transplant may vary thus leading to significant changes in anterior translation of the operated knee.     

Hamstring tendon autograft versus LARS artificial ligament for arthroscopic posterior cruciate ligament reconstruction in a long-term follow-up

Introduction

Surgical reconstruction has been increasingly recommended for the surgical management of posterior cruciate ligament (PCL) ruptures. While the choice of tissue graft still remains controversial. Currently both hamstring tendon autograft (HTG) and ligament advanced reinforcement system (LARS) artificial ligament are widely used but there are seldom reports on the comparisons of their clinical results. Our study was aimed to assess the effectiveness of these two grafts.

Materials and methods

Thirty-five patients with unilateral PCL rupture were enrolled in this retrospectively study. Sixteen of them received arthroscopically assisted PCL reconstruction using hamstring tendon autografts (HTG group) and nineteen using LARS ligaments (LARS group). All cases were followed up for 46–57 months with a mean of 51 months. Follow-up examinations included radiographic assessment, Lysholm score, Tegner score, International Knee Documentation Committee (IKDC) rating scales and KT-1000 test.

Results

All patients improved significantly at the final follow-up compared with the examinational results preoperatively and there were no significant differences between HTG group and LARS group with respect to the results of radiographic assessment, Lysholm score, Tegner score, IKDC rating scales and KT-1000 test.

Conclusions

Similar good clinical results were obtained after PCL reconstruction using hamstring tendon autografts and LARS ligaments. Both LARS ligament and hamstring tendon autograft are ideal grafts for PCL reconstruction.     

残端悬吊包绕肌腱移植物重建前交叉韧带

目的:探讨残端悬吊包绕肌腱移植物重建前交叉韧带的价值。方法:2009年6月至2011年6月对76例前交叉韧带损伤的患者采用残端悬吊包绕肌腱移植物重建前交叉韧带治疗。男59例,女17例;年龄15～46岁,平均29岁。其中运动伤32例,训练伤20例,交通事故伤16例,其他损伤8例。受伤至手术时间平均3周(2～5周)。术前前抽屉试验阳性72例,Lachman试验阳性76例,IKDC主观评分45.9±3.6,Lysholm评分54.3±4.5。结果:术后患者切口均Ⅰ期愈合,无相关并发症发生。69例获得随访,时间17～31个月,平均23个月。末次随访Lachman试验均呈阴性;IKDC评级A级36例,B级30例,C级3例,D级0例;IKDC主观评分91.5±3.4,较术前提高;Lysholm评分92.4±3.8,较术前提高。结论:采用残端悬吊包绕肌腱移植物重建前交叉韧带有助于移植肌腱的修复,临床疗效满意。     

Long-term outcome of anterior cruciate ligament reconstruction with an autologous four-strand semitendinosus tendon autograft

Purpose

Although the short- and mid-term outcomes of ACL reconstruction with a hamstring graft are promising, clinical investigations reporting the long-term results after ten years or longer are rare. Therefore we performed a retrospective single-blinded evaluation of ACL reconstruction using a four-stranded single-bundle reconstruction with a semitendinosus tendon graft with extracortical fixation.

Methods/Results

At follow-up patients obtained at least the same level in the clinical outcome scores (Lysholm, IKDC, Tegner) compared to previous studies with a similar follow-up time using a STG graft. Furthermore there was no detectable difference in the incidence of osteoarthritis. Patients having a negative pivot shift test showed significantly fewer signs of radiographic osteoarthritis and better functional assessment scores.

Conclusion

On the basis of our investigation, we conclude that the reconstruction of the ACL by a quadrupled semitendinosus tendon graft with extracortical anchorage can achieve excellent clinical and subjective results after a follow-up of ten years.     

保留并牵张残留纤维的前十字韧带双束重建术

目的 评估在亚急性期进行保留并牵张残留纤维的前十字韧带双束重建的临床效果.方法 2006年1月至2006年6月,对56例前十字韧带损伤患者在亚急性期进行保留并牵张残留纤维的前十字韧带双束重建.前十字韧带双束重建采用四隧道八股肌腱移植的方法.使用PDS缝线穿缝胫骨侧残留纤维,经深束股骨隧道牵张固定.使用IKDC及Lysholm评分标准评估疗效.结果 53例随访2年以上.末次随访时所有患者Lachman试验均为阴性.屈膝25°KT-1000检测结果显示双侧膝关节松弛度差值为(-0.44±1.53)mm,与术前(8.01±1.83)mm比较差异有统计学意义(t=37.03,P=0.0001).29例(54.7%)双侧膝关节松弛度差值小于0mm,提示患膝相对于健侧更为稳定或紧张.24例(45.3%)双侧膝关节松弛度差值为0～2mm.所有患者轴移试验均阴性.48例膝关节活动度正常,2例有5°屈曲受限,1例有小于5°屈曲受限,2例有5°过伸受限.根据IKDC评估标准,51例(96.2%)正常,2例(3.8%)接近正常.IKDC主观评分为(95.6±3.1)分,Lysholm评分为(94.8±2.9)分.受伤前Tegner评分平均为7.3分,末次随访时为7.1分.结论 根据2年以上随访结果,以IKDC为评估标准,保留并牵张残留纤维的前十字韧带双束重建能够使96.2%的患者恢复正常,3.8%的患者接近正常.     

Quadrupled bone-semitendinosus ACL reconstruction: a prospective clinical investigation in 100 patients

Abstract The hypothesis of our study was that a quadrupled bonesemitendinosus tendon graft could combine the advantage of bone-tobone healing with the high cross-sectional area of a quadrupled hamstring graft in ACL reconstruction. ACL reconstruction with a semitendinosus tendon graft was performed on 100 patients with isolated ACL injury from January 1996 to December 1999: femoral fixation was obtained with Endobutton and tibial fixation with Fastlok. Patients were evaluated for standard knee scores and functional strength tests, postoperative pain rating, knee radiographs taken after surgery and at final follow-up, magnetic resonance images at 3 and 6 months, isokinetic flexion-extension and internal-external rotation tests at 3, 6, and 12 months. Computerized laxity analysis was performed at final evaluation. Average surgical time was 85 minutes, including 13 minutes for graft preparation; 90% of the patients were discharged within 24 h. Subjective knee rating was 80%; kneeling test was positive in 7% and Werner score was 44 (range, 30–48). Lachman test was negative in 90% at final evaluation (mean follow-up, 38 months). Sensory changes at the anterior part of the proximal tibia were present in 30% at 3 months and 10% had definite hyposthesia. MRI showed graft incorporation at 3 months. Computerized laxity analysis revealed 90% with less than 3-mm side-to-side differences. Isokinetic testing showed normal hamstring and quadriceps peak torques at 12 months. The functional strength tests were normal by 6 months. Average Noyes score was 87.9, Lysholm score 93, and Tegner activity rating 6.0 (pre-injury, 6.1). IKDC score showed 90 normal or nearly normal knees, 9 abnormal, and one severely abnormal knee. Quadrupled bone-semitendinosus is a viable graft for ACL reconstruction and should be considered, especially in patients with pre-existing extensor mechanism problems.     

A comparison of the outcomes of anterior curciate ligament reconstruction with large-size graft versus reconstruction with average-size graft combined with extraarticular tenodesis

IntroductionMany patients who have had anterior cruciate ligament (ACL) reconstruction (R) complain of instability, inability to return to previous levels of sports activity, and possible ACL graft failure. Graft size was discovered to be an important factor in lowering ACL failure rates. Also, extraarticular tenodesis decreases recurrent instability, A comparative study was done to compare the effect of graft size and lateral external tenodesis on the recurrence of instability after ACL-R.Patients and methodsA Prospective Blinded Randomized Controlled study included 100 consecutive patients who underwent ACL-R with hamstring tendon grafts in our Hospital. The patients were allocated into two groups (Group A and B) with randomization; group A received ACL-R with a large-size ACL-graft diameter of 6 strands, and group B received ACL-R of 4 strands combined with lateral extraarticular tenodesis (LET) (Modified Lemaire). Each group had fifty patients. The follow-up time was two years. They were examined for graft failure, anterolateral rotatory instability with the pivot shift test, and clinical outcomes, which were evaluated with the International Knee Documentation Committee score (IKDC) both subjective and objective.ResultsIn this study; group A, graft failure occurred in three (6.3%) patients, a positive pivot shift test grade I was detected in eight (17.8%) patients, grade II in three (6.7%) patients, and grade III in one (2.2%) patient. The subjective IKDC score was 87.9 (± 7.19) points. The objective IKDC score was normal or nearly normal in 43 (93.4%) patients. In group B, one (2.1%) patient had graft failure, five (10.9%) had a positive pivot shift test grade I, one (2.1%) had a grade II, and no patient had a grade III. The subjective IKDC score was 91.9 (± 8.9) points. The objective IKDC score was normal or nearly normal in 44 (95.6%) patients. As regard the subjective IKDC score, there was a non-significant difference between both groups (p value = 0.465).ConclusionBoth groups showed a low ACL-graft failure rate, low anterolateral rotatory instability, and a good clinical outcome. Although there was no significant difference in subjective IKDC score between both groups, the failure rate and anterolateral rotatory instability were significantly lower in the ACL-R (4 strands) with LET combination group than in the group with the large-diameter (6 strands) graft.Level of evidenceLevel 1; Randomized Comparative Study.     

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     

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.

     

关节镜下自体腘绳肌腱重建内侧髌股韧带治疗复发性髌骨脱位

目的探讨关节镜下采用自体腘绳肌腱重建内侧髌股韧带治疗复发性髌骨脱位的疗效。方法 2005年1月-2010年1月,对22例(22膝)复发性髌骨脱位患者采用关节镜下外侧支持带松解,取自体腘绳肌腱重建内侧髌股韧带治疗。男5例,女17例;年龄15～19岁,平均17.3岁。髌骨脱位3～8次,平均4次。主要临床症状为患膝关节疼痛、肿胀、无力,活动受限。髌骨倾斜试验、恐惧试验、内侧髌股韧带止点处压痛、髌骨向外推移时恐惧征均呈阳性。根据国际膝关节文献委员会(IKDC)评分标准,膝关节功能主观评分为(36.7±4.7)分,Lysholm评分为(69.3±3.8)分。X线片示患者髌骨向外倾斜。结果术后切口均Ⅰ期愈合。患者均获随访,随访时间18～49个月,平均34个月。术后患者关节疼痛、肿胀、无力等症状较术前明显改善。随访期间患者髌骨脱位无复发。末次随访时,IKDC膝关节功能主观评分为(92.4±5.3)分,Lysholm评分为(91.7±5.2)分,与术前比较差异均有统计学意义(P<0.05)。结论关节镜下取自体腘绳肌腱重建内侧髌股韧带可明显改善髌骨稳定性,是治疗复发性髌骨脱位的有效方法之一。     

Reconstruction of the anterior cruciate ligament in females

Purpose: To compare the clinical results of anterior cruciate ligament reconstruction in female patients using quadruple-looped hamstring autograft versus patellar tendon autograft at minimum 2-year follow-up. Type of Study: Case series. Methods: A prospective clinical review was performed to compare the results of ACL reconstruction with hamstring versus patellar tendon autograft in a group of female patients. Exclusion criteria included chronic injuries (greater than 3 months), associated collateral ligament injuries, Workers’ Compensation or litigation cases, and bilateral anterior cruciate ligament injuries. There were 39 female patients in the hamstring group (average follow-up, 40.9 months) and 37 female patients in the patellar tendon group (average follow-up, 52 months). Both types of grafts were fixed with an EndoButton proximally and with sutures tied over a post or button distally. The postoperative rehabilitation regimen was identical for both groups. Objective parameters evaluated included preinjury and postoperative Tegner and Lysholm scores, side-to-side KT-1000 maximum-manual arthrometer differences, and clinical examination including Lachman and pivot-shift tests. Graft failure was defined by any one of the following: a KT-1000 difference of greater than 5 mm, a 2+ Lachman, a 1+ or greater pivot shift, or revision surgery. Results: The failure rate in the hamstring group was 23% versus 8% in the patellar tendon group, which was not statistically significant (P > .1). Comparison of preinjury Tegner activity scores to postoperative scores revealed that patients in the hamstring group did not return to their preinjury level of activity (preinjury 6.54 v postoperative 5.17) as well as patients in the patellar tendon group (preinjury 6.20 v postoperative 6.59). Patients in the hamstring group had a significant increase in pain compared with the patellar tendon group (P = .034). Conclusions: Although not statistically significant, the hamstring group had more failures, more laxity on clinical examination, and more patients with larger KT-1000 arthrometer differences. These results indicate a trend toward increased graft laxity in female patients undergoing reconstruction with hamstring autograft compared with patellar tendon when evaluated by a single surgeon using similar fixation techniques at short- to medium-range follow-up. More studies with larger patient numbers using current fixation techniques are necessary to confirm these findings.     

Impact of tendon suturing on the interference fixation strength of quadrupled hamstring tendon grafts

Introduction

Interference screw fixation of soft tissue grafts has been a widely used fixation technique for cruciate ligament reconstruction. Suturing of the graft construct prior to graft fixation has been proposed to increase fixation strength; however, the effect on mechanical properties has not been well characterized. The goal of this study was to determine whether uniform suturing of the tendon graft affects (1) ultimate fixation strength of the hamstring tendon graft and (2) motion of the tendon in the bone tunnel during cyclic loading when comparing sutured grafts vs. unsutured grafts.

Method

Eight pairs of matched mature porcine tibias (age <2 years) and eight paired fresh-frozen human quadrupled hamstring tendon grafts were used. One quadrupled graft from each pair was placed into one of two groups. In the group A a single cerclage suture 3 cm from the doubled end of the graft was placed to join the four tendon strands. In group B a heavy suture was used to tightly unite the four strands of tendon graft to provide a better grip for the interference screw during fixation. The grafts were placed in tibial bone tunnels that matched the graft’s diameter and fixed with an interference screw. The looped end of the graft and the attached tibia were rigidly fixed in a material testing machine. The graft constructs were subjected to 100 cycles of 20–250 N load, followed by a load-to-failure test. In addition, a motion analysis system was used during cyclic testing to better determine the amount of elongation at the graft–tunnel interface. Statistical analysis of the failure load and stiffness and the overall elongation following cyclical loading was performed using the Wilcoxon rank sum test. Level of significance was set at p < 0.05.

Results

Elongation at the tendon–bone interface during sub-maximal cyclic loading was 2.4 ± 1.4 mm (unsutured) vs. 2.0 ± 0.7 mm (sutured) (p > 0.05). Failure load of the grafts without sutures (634 ± 86 N) was significantly lower than with the sutures (837 ± 183 N). Ultimate stiffness of group A (283 ± 34 N/mm) was lower than that of group B (331 ± 51 N/mm); however, this was not statistically significant (p = 0.051).

Conclusion

This study confirms that suturing of the graft construct before interference screw fixation may increase ultimate failure load. However, an improvement of structural properties in response to cyclic loading with sub-maximal loads could not be confirmed. Clinicians using interference screw fixation may suture the graft to improve fixation strength; however, suturing does not appear to allow a more aggressive rehabilitation after surgery.     

Clinical Results of Technique for Double Bundle Anterior Cruciate Ligament Reconstruction Using Hybrid Femoral Fixation and Retroscrew

Background

Anatomic anterior cruciate ligament (ACL) reconstruction has been presented as a means to more accurately restore the native anatomy of this ligament. This article describes a new method that uses a double bundle to perform ACL reconstruction and to evaluate the clinical outcome.

Methods

Grafts are tibialis anterior tendon allograft for anteromedial bundle (AMB) and hamstring tendon autograft without detachment of the tibial insertion for posterolateral bundle (PLB). This technique creates 2 tunnels in both the femur and tibia. Femoral fixation was done by hybrid fixation using Endobutton and Rigidfix for AMB and by biointerference screw for PLB. Tibial fixations are done by Retroscrew for AMB and by native insertion of hamstring tendon for PLB. Both bundles are independently and differently tensioned. We performed ACL reconstruction in 63 patients using our new technique. Among them, 47 participated in this study. The patients were followed up with clinical examination, Lysholm scales and International Knee Documentation Committee (IKDC) scoring system and radiological examination with a minimum 12 month follow-up duration.

Results

Significant improvement was seen on Lachman test and pivot-shift test between preoperative and last follow-up. Only one of participants had flexion contracture about 5 degrees at last follow-up. In anterior drawer test by KT-1000, authors found improvement from average 8.3 mm (range, 4 to 18 mm) preoperatively to average 1.4 mm (range, 0 to 6 mm) at last follow-up. Average Lysholm score of all patients was 72.7 ± 8.8 (range, 54 to 79) preoperatively and significant improvement was seen, score was 92.2 ± 5.3 (range, 74 to 97; p < 0.05) at last follow-up. Also IKDC score was normal in 35 cases, near normal in 11 cases, abnormal in 1 case at last follow-up.

Conclusions

Our new double bundle ACL reconstruction technique used hybrid fixation and Retroscrew had favorable outcomes.     

Hamstring tendon autograft better than bone patellar-tendon bone autograft in ACL reconstruction: a cumulative meta-analysis and clinically relevant sensitivity analysis applied to a previously published analysis

Background Current debate on treatment options for anterior cruciate ligament (ACL) reconstruction complicate the choice between hamstring and bone patellartendon bone autografts. We hypothesized a priori that cumulative meta-analysis (a form of sensitivity analysis) might show that the evidence for reduction of morbidity by hamstring grafts could have been reached at an earlier time. Furthermore, we hypothesized a priori that modern state-of-the-art hamstring graft fixation technique would give similar results regarding stability as bone-patellar tendon-bone autografts.

Methods We performed a cumulative meta-analysis and sensitivity analysis based on femoral graft fixation techniques to compare hamstring autograft and bonepatellar tendon-bone autografts in ACL reconstruction derived from a previously published meta-analysis.

Results Cumulatively, that hamstring autograft reduces anterior knee pain had already reached statistical significance in 2001 (relative risk 0.49 (95%CI: 0.32-0.76; p = 0.001, I2 = 0%)). The modern endobutton hamstring graft fixation technique (2 studies) yielded similar stability in the Lachman test as bone-patellar tendon-bone grafts, with a relative risk of 1.1 (95%CI: 0.82-1.5; p = 0.6, I2 = 0%). Exclusion of the endobutton group explains the increased laxity in the hamstring graft group.

Interpretation Cumulative meta-analysis strengthens the evidence for reduced morbidity using hamstring tendon autograft for anterior cruciate ligament reconstruction. Sensitivity analysis focusing on state-of-the-art hamstring graft fixation techniques further weakens the evidence that bone-patellar tendon-bone autografts provide better stability.     

自体腘绳肌腱和同种异体半腱肌腱双束重建前十字韧带的比较研究

目的 对比自体腘绳肌腱和同种异体半腱肌腱双束重建前十字韧带的初期临床疗效.方法 2006年2月至8月,对单纯前十字韧带完全断裂患者分别采用自体腘绳肌腱(简称自体组,38例)和同种异体半腱肌腱(简称异体组,23例)行前十字韧带双束重建手术.客观指标包括:双侧膝关节前向松弛度差异、Lachman试验、轴移试验和双下肢周径差别;应用Tegner评分表、Lysholm评分表和IKDC评分表进行膝关节功能的主观评估.结果 自体组平均随访27个月,异体组平均随访26个月.末次随访时Lachman试验:自体组35例阴性,3例Ⅰ度阳性;异体组20例阴性,2例Ⅰ度阳性,1例Ⅲ度阳性.两组各有1例轴移试验阳性.双侧膝关节前向松弛度差异:自体组34例差异范围0～2 mm,4例3～5mm;异体组20例0～2mm,2例3～5 mm,1例>10 mm.双下肢周径差别:自体组(0.62±0.43)cm,异体组(0.57±0.42)cm.Tegner评分:自体组(6.21±0.84)分,异体组为(6.17±1.15)分.Lysholm评分:自体组(95.00±4.40)分.异体组(94.57±8.83)分.IKDC评分:自体组(90.26±2.92)分,异体组(89.48±7.27)分.结论 应用自体腘绳肌腱和同种异体半腱肌腱双束重建前十字韧带均能取得优良的初期临床结果.     

Fremdmaterialfreie vordere Kreuzbandplastik mit der Patellasehne in Press-fit-Doppelbündeltechnik

Anterior cruciate ligament (ACL) reconstruction using autologous tendons (BTB patellar tendon, hamstrings, quadriceps tendon) in an implant-free fixation technique is becoming more and more popular due to biological and economical reasons. In1987 an implant-free press-fit fixation technique of a BTB graft from the medial side of the patellar tendon (via mini-arthrotomy) was introduced and first published during the 4th ESKA Conference 1990 in Stockholm. Special emphasis is given to the anatomical orientation of the BTB graft. During the inside-out femoral press-fit fixation the bone-ligament margin of the graft is placed directly into the femoral insertion line of the natural ACL adapting its double-bundle structure. The graft is fixed by press-fit within the tibial metaphysis and its ligamentous part is secured in the metaphysis by harvested cancellous bone blocks driven into the joint line from the outside. The postoperative regime includes weight-bearing as tolerated and free motion. Out of 159 patients 95 could be seen for follow-up after an average of 10.7 years. The final IKDC knee score revealed 22.1% in group A (very good) and 62.1% in group B (good). The Tegner activity level was 6.8 preinjury and 6.0 postoperatively. The average KT 1,000 side-to-side difference was 1.8 mm. Subjectively no patient complained of instability and 99% of the patients could kneel on hard ground with minimal or no complaints. ACL revision surgery due to graft failure was not necessary in any of the patients. Advantages of the described procedure are a narrow anatomical orientation including the double bundle structure of the ACL, rapid graft incorporation by bone-to-bone healing, lack of bone resorption at the graft-host interface, decreased donor site morbidity, cost-effectiveness and ease of possible revision surgery.