Skin sensory change after arthroscopically-assisted anterior cruciate ligament reconstruction using medial hamstring tendons with a vertical incision

The purpose of this study was to clarify and document light-touch sensory change of the lower leg after arthroscopically-assisted ACL reconstruction using medial hamstring tendons with a vertical incision. Eighty-six patients were directly followed up during a mean of 32.0 months after surgery. Sixty patients responded to a mailed questionnaire about affect of sensory change on daily living. Forty-seven patients out of 86 (55%) indicated some sensory change of the lower leg, which was usually hypoesthesia with an average verbal score of 6.9. The questionnaire revealed that one patient out of 60 complained that the sensory change adversely affected daily living. A sensory-change area with a mean of 53.2 cm² was located distally from the incision in 40% of the cases; it was located proximally and distally in 56%. Blunt exposure for harvesting the tendons failed to decrease the occurrence of the sensory change. After ACL reconstruction using medial hamstring tendons with a vertical incision, sensory change was frequently found. Daily living was, however, only slightly affected by the sensory change.     

Regeneration of hamstring tendons after anterior cruciate ligament reconstruction

Purpose

Primary aim of the study was analysis of hamstring tendon regeneration after anterior cruciate ligament reconstruction (ACLR). Secondary aim was analysis of isokinetic muscle strength in relation to hamstring regeneration. The hypothesis was that regeneration of hamstring tendons after ACLR occurs and that regenerated hamstring tendons contribute to isokinetic hamstring strength with regeneration distal to the knee joint line.

Methods

Twenty-two patients scheduled for ACLR underwent prospective MRI analysis of both legs. MRI parameters were tendon regeneration and morphology, muscle retraction and muscle cross-sectional area. A double-blind, prospective analysis of isokinetic quadriceps and hamstrings strength was performed.

Results

Regeneration of the gracilis tendon after ACLR occurred in all patients. Regeneration of the semitendinosus tendon occurred in 14 patients. At 1 year, the surface area of the semitendinosus and gracilis muscle decreased compared to both preoperatively (P < 0.01) and the contralateral leg (P < 0.01). The cross-sectional area of the semitendinosus muscle decreased in the absence of tendon regeneration (P = 0.05). The cross-sectional area of the gracilis muscle was greater in case of regeneration distal to the joint line (P = 0.01). Muscle retraction of the semitendinosus muscle was increased in case of nonregeneration (P = 0.02). There was no significant relationship between isokinetic flexion strength and tendon regeneration.

Conclusion

Hamstring tendons regenerated after harvest of both semitendinosus and gracilis tendons for ACLR. There was no relation between isokinetic flexion strength and tendon regeneration.

Level of evidence

Prognostic study, Level II.     

The role of periosteal flap in the prevention of femoral widening in anterior cruciate ligament reconstruction using hamstring tendons

Tunnel widening in anterior cruciate ligament reconstruction has been reported for many years, whatever the type of plasty (allo- or autograft) or graft (patellar or hamstring tendons). Recently, the hypothesis has been formulated that widening would be responsible for later laxity of the knees. Micromobility of the graft or biological factors are classically responsible for the enlargement. In order to improve the biological conditions around the graft within the tunnel, we have developed a surgical technique using a periosteal flap. The periosteal flap is harvested at the superior and medial metaphysis of the tibia and wrapped around the proximal part of the four strands of gracilis and semitendinosus tendons near the outlet of the femoral tunnel. Forty-one patients with isolated rupture of the ACL were included in a prospective and randomized study: the first group of 20 patients had femoral fixation by Transfix and resorbable screw, the second group of 21 patients had femoral fixation by Transfix and periosteal flap. The diameters of the tunnel were measured between the sclerotic margins at the tunnel entrance and 1 cm above, and compared to the peroperative drill size. The percentage change in diameter was calculated as: (tunnel diameter–drill size)/drill size. The two groups of patients were comparable as to gender, side, age, KT-1000 side to side difference, femoral tunnel diameter and follow-up. At 2.5 months and 11 months postoperatively on average, there was a significant reduction of enlargement at the outlet of the tunnel with the use of a periosteal flap but widening was constant.     

Morphometry of the semitendinosus and gracilis tendons with application to anterior cruciate ligament reconstruction

The length and cross-sectional area of human semitendinosus and gracilis tendons were measured in both single- and multi-strand configurations for the purpose of anterior cruciate ligament graft preparation. The average lengths of the semitendinosus and the gracilis tendons were 235±20 mm (mean±SD) and 200±17 mm, respectively. The cross-sectional area of a doubled semitendinosus tendon (two strands) was significantly less than that of a 10-mm-wide patellar tendon graft (P<0.001). The cross-sectional area of the tripled semitendinosus tendon (three strands) and the 10-mm-wide patellar tendon were similar. Doubling of the combined semitendinosus and gracilis tendons (four strands) and tripling of this combination (six strands) resulted in a significantly greater cross-sectional area in comparison to the 10-mm-wide patellar tendon (P<0.05, four strands;P<0.001 six strands). This investigation demonstrates that anterior cruciate ligament grafts fashioned using multiple-strand combinations of the semitendinosus and gracilis tendons result in a cross-sectional area that is comparable to the bone-patellar tendon-bone graft. This is an important finding since cross-sectional area reflects the intra-articular volume of collagenous tissue. This information should be helpful to surgeons considering using the hamstring tendons as an anterior cruciate ligament graft.     

Two-bundle, four-tunnel anterior cruciate ligament reconstruction

We reviewed 33 patients who underwent anterior cruciate ligament (ACL) reconstruction using a two-bundle, four-tunnel technique. The posterolateral bundle (PLB) and anteromedial bundle (AMB) were individually reconstructed with gracilis and semitendinosus tendon auto-grafts, respectively, using separate tibial and femoral tunnels. At final follow-up (24 months post surgery, range 18–31) the International Knee Documentation Committee’s (IKDC) objective final evaluation scores were 69 A, 19 B, 12% C. The mean global subjective IKDC score was 86±12 points. Ninety-four percent of the patients had returned to sport after an average of 9 months following surgery and 75% returned to their preinjury sporting level. One patient had suffered a graft rupture as a result of a further sports injury. Eighty-four percent of the patients had a negative pivot shift (IKDC A), 9% a glide (IKDC B), and 6% a “clunk” (IKDC C). The mean postoperative side-to-side laxity, measured with KT1000 arthrometry at manual maximum, was 0.9 mm (SD 1.9). Eighty-one percent of the patients had less than 3 mm difference, with only one patient having greater than 5 mm. Our early experience with this new technique appears to demonstrate satisfactory results that are at least equivalent to other techniques and show an apparent trend towards improved control of anterior laxity.     

关节镜下自体半腱及股薄肌腱重建膝前交叉韧带

 目的 探讨关节镜下以自体半腱肌、股薄肌腱重建膝前交叉韧带(ACL)的手术方法及疗效.方法 自2006年3月～2007年12月,关节镜下绳肌腱修复膝前交叉韧带损伤39例.膝前小切口取半腱肌腱、股薄肌腱修整、对折后成四股,分别建立胫骨隧道及股骨隧道,用Endobutton和生物可吸收挤压螺钉固定肌腱,重建ACL的解剖结构和生理功能.术后即行功能锻练.结果 术后患者伤口均Ⅰ期愈合,8～10周膝关节屈伸功能恢复正常.随访时间3～15个月,平均8个月.抽屉试验和Lachman试验阳性者2例,可疑阳性者6例;余患者均为阴性.根据敖英芳临床判断标准,本组优23例,良11例,中3例,差2例.Lysholm评分术后(87.6±4.6),与术前(45.3±4.2)比较,差异显著(P<0.01).结论 绳肌腱具有良好的抗拉强度和刚度,在关节镜下用四股绳肌腱重建膝前交叉韧带是一种疗效可靠的治疗方式.     

The effect of accelerated,brace free,rehabilitation on bone tunnel enlargement after ACL reconstruction using hamstring tendons: a CT study

The mechanism of bone tunnel enlargement following anterior cruciate ligament (ACL) reconstruction is not yet clearly understood. Many authors hypothesized that aggressive rehabilitation protocols may be a potential factor for bone tunnel enlargement, especially in reconstructions performed with hamstrings autograft. The purpose of this study was to evaluate the effect of a brace free rehabilitation on the tunnel enlargement after ACL reconstruction using doubled semitendinosus and gracilis tendons (DGST): our hypothesis was that early post-operative knee motion increase the diameters of the tibial and femoral bone tunnels. Forty-five consecutive patients undergoing ACL reconstruction for chronic ACL deficiency were selected. All patients were operated by the same surgeon using autologous DGST and the same fixation devices. Patients with associated ligaments injuries and or severe chondral damage were excluded. The patients were randomly assigned to enter the control group (group A, standard post-operative rehabilitation) and the study group (group B, brace free accelerated rehabilitation). A CT scan was used to exactly determine the diameters of both femoral and tibial tunnels at various levels of lateral femoral condyle and proximal tibia, using a previously described method [17]. Measurements were done by an independent radiologist in a blinded fashion the day after the operation and at a mean follow-up of 10 months (range 9–11). Statistical analysis was performed using paired t-test. The mean femoral tunnel diameter increased significantly from 9.04 ± 0.05 (post-operative) to 9.30 ± 0.8 mm (follow-up) in group A and from 9.04 ± 0.03 to 9.94 ± 1.12 mm in group B. The mean tibial tunnel diameter increased significantly from 9.03 ± 0.04 to 10.01 ± 0.80 mm in group A and from 9.04 ± 0.03 to 10.60 ± 0.78 mm in group B. The increase in femoral and tunnel diameters observed in the study group was significantly higher than that observed in the control group. Our results suggest that bone tunnel enlargement after ACL reconstruction using hamstrings autograft can be increased by an accelerated, brace free, rehabilitation protocol.     

Anterior cruciate ligament reconstruction in females: a comparison of hamstring tendon and patellar tendon autografts

This study compared hamstring (HS) and patellar tendon (PT) anterior cruciate ligament (ACL) reconstruction in females. Sixty-five patients (43 HS, 22 PT) were evaluated at a mean 3.8-year postoperatively. Evaluation included IKDC 2000, SF-36, Cincinnati sports activity scores, anterior knee pain (AKP), kneeling pain, range of motion and anterior knee laxity. One PT patient sustained a traumatic graft rupture. There were no differences between the two grafts in terms of anterior knee laxity or IKDC scores. The HS group had higher sports activity scores and higher scores on the Physical Functioning and General Health subscales of the SF-36. Despite no difference in AKP, there was greater kneeling pain in the PT patients, who also had greater extension deficits. Both HS and PT are satisfactory ACL grafts in females, but HS grafts were associated with less morbidity, greater return to preinjury level of activity and higher quality of life scores.     

关节镜下自体四股腘绳肌腱重建膝前交叉韧带

目的评估关节镜下自体四股腘绳肌腱重建膝前交叉韧带(ACL)的技术和效果方法1999年10月-2003年12月共56例患者经关节镜检查证实为ACL断裂,26例伴半月板破裂,7例伴内侧副韧带损伤,12例伴后交叉韧带断裂。均于关节镜下行自体四股腘绳肌腱ACL重建术,采用Bionx生物可吸收挤压螺钉或钛挤压螺钉解剖位固定重建韧带。结果本组术后早期均未发生严重并发症。术后随访6-48个月,平均20个月,Lysholm膝关节功能评分由术前45-80分(平均58.36分),提高至随访时70-100分(平均92.77分)(P<0.01)。国际膝关节文件编制委员会(IKDC)综合评定由术前异常(C级)14例、显著异常(D级)42例,改进为随访时正常(A级)23例、接近正常(B级)29例、异常(C级)4例(P<0.01)。56例患者中,52例恢复伤前运动水平,4例运动水平较伤前降低。结论关节镜下自体四股腘绳肌腱重建膝ACL具有手术损伤较小、术后膝关节功能恢复良好的优点,值得采用。     

One-stage anatomic double-bundle anterior and posterior cruciate ligament reconstruction using the autogenous hamstring tendons

This is the first report of an anatomic double-bundle ACL and PCL reconstruction procedure with the autogenous hamstring tendons. We prepare two pairs of the doubled tendon grafts, to which a polyester tape and an Endobutton-CL are attached using our original technique at the tibial and femoral ends, respectively. Under arthroscopic and fluoroscopic observations, two tibial tunnels for PCL reconstruction are created so that they pass through the posteromedial and anterolateral bundle attachments, respectively. Then, we create two tibial tunnels for anatomic double-bundle ACL reconstruction so that each tunnel axis is aimed at a targeted point on the femoral condyle. Using the outside-in technique, two femoral tunnels for PCL reconstruction are created so that the tunnel outlets are located at the center of the anterolateral and posteromedial bundle attachments. Then, two femoral tunnels for anatomic double-bundle ACL reconstruction are created with the trans-tibial tunnel technique. After the two grafts have been placed for PCL reconstruction, the two grafts are placed for ACL reconstruction. After all the femoral graft ends are fixed, the knee joint is reduced to the full extension position, and then, the four tibial tape portions are simultaneously fixed with the turn-buckle stapling technique.     

One-stage bilateral anterior cruciate ligament reconstruction with use of hamstring tendon autografts: a case report

This article presents an unusual problem of a patient with chronic bilateral ACL-deficient knees and constitutionally very thin patellar tendons. Author decided to perform one-stage bilateral ACL reconstructions using hamstring tendon autografts so as not to weaken his quadriceps muscles by compromising his extensor mechanism.     

Tibial press-fit fixation of the hamstring tendons for ACL-reconstruction

Press-fit fixation of patellar tendon bone anterior cruciate ligament autografts is an interesting technique because no hardware is necessary to achieve fixation. Up till the present point, there is no biomechanical data available for the tibial press-fit fixation of the hamstring tendons. Hamstring tendons of 21 human cadavers (age: 41.9 ± 13.1 years) were used. A press-fit fixation with looped semitendinosus and gracilis tendons secured by a tape (T) over a bone bridge, or by a baseball-stitched suture (S), was compared with degradable interference screw fixation (I) in 21 porcine tibiae. The constructs were cyclically strained and subsequently loaded to failure. The maximum load to failure, stiffness, and elongation during cyclical loading were measured. The maximum load to failure was highest for the T-fixation at 970 ± 83 N, followed by the I-fixation with 544 ± 109 N, and the S-fixation with 402 ± 78 N (P < 0.03). Stiffness of the constructs averaged 78 ± 13 N/mm for T, 108 ± 18 N/mm for S, and 162 ± 27 N/mm for I (P < 0.03). Elongation during initial cyclical loading was 2.0 ± 0.6 mm for T, 3.3 ± 1.1 mm for S, and 1.4 ± 0.5 mm for I (S inferior to I and T, P<0.05). Elongation between the 20th and 1,500th loading cycle was lower for T (2.2 ± 0.7 mm) compared with I (4.1 ± 2.7 mm) and S (4.8 ± 0.7 mm; P < 0.001). The T-fixation technique exhibited a significantly higher failure load than the S-, and I- techniques. All techniques exhibited larger elongation during initial cyclical loading than is reported in the literature for grafts with bone blocks. Only one technique (T) showed satisfactory elongation behavior during long-term cyclic loading. Interference screw fixation demonstrated significantly higher stiffness. Only one of the investigated techniques (T) seemed to exhibit adequate mechanical properties necessary for early aggressive rehabilitation programs.     

Driving reaction time before and after anterior cruciate ligament reconstruction

Driving reaction time was studied in 73 patients under anterior cruciate ligament (ACL) reconstruction using a computer-linked automobile simulator. Each patient was tested pre-operatively and 2, 4, 6 and 8 weeks after surgery. Stepping and standing tests were studied at each time point. Twenty-five normal subjects were also tested as controls. Pre-operative test results did not differ significantly between groups on any of the tests. Post-operatively it took 6 weeks for driving reaction time of the right ACL group to be equivalent to that of the controls, compared to 2 weeks in the left ACL group. There was a strong correlation between the stepping and standing tests and the driving reaction time; this made them good clinical tests to monitor patients’ progress and to suggest the appropriate time to resume driving. Received: 18 October 1999 Accepted: 2 February 2000     

Bone tunnel enlargement following hamstring anterior cruciate ligament reconstruction: a comprehensive review

Nowadays, bone tunnel enlargement (BTE) after anterior cruciate ligament reconstruction is a well-known phenomenon. It has been identified, investigated and described by many authors during the last thirty years. Nevertheless, the etiology of bone tunnel enlargement still remains unclear. It is known that the causes are multifactorial and may include the surgical technique, the method of fixation, materials used, type of graft as well as biological factors. Due to the recent popularization of the use of hamstring grafts in anterior cruciate ligament reconstruction, the bone tunnel enlargement phenomenon is becoming increasingly common. In this review article, the authors focus on compiling current knowledge about the etiology, diagnosis, and the possibility of reducing the occurrence of this phenomenon by using the latest methods of supporting reconstruction surgery.     

The mid- to long-term results of the anterior cruciate ligament reconstruction with hamstring tendons using Transfix technique

In this study, mid to long-term results of anterior cruciate ligament reconstruction with hamstring tendons and Transfix technique were evaluated. Anterior cruciate ligament (ACL) reconstruction with four-strand hamstring tendon was performed with Transfix technique on 271 (198 males, 73 females; mean age 25.7; 17–52) patients with anterior cruciate ligament ruptures. The patients were followed up with clinical examination, Lysholm and Tegner activity scales, IKDC scoring system, KT-1000 test and radiological examination. The mean follow-up period was 82 (48–100) months; 204 (75%) patients had no subjective complaints. According to the KT-1000 test, only 14 (5%) patients had more than 5 mm laxity postoperatively, whereas, 161 (59%) patients had more than 5 mm laxity preoperatively. In addition to this, only 19 (7%) patients had Lysholm scores less than 80 postoperatively, whereas 154 (57%) patients scored less than 80 preoperatively. When compared with Tegner activity scale, 189 (70%) patients scored <6 preoperatively and only 24 (8%) postoperatively; 78 (29%) patients scored D preoperatively and only 5 (2%) patients scored D postoperatively on the basis of the IKDC scoring system. Our functional results were found to be satisfactory in more than 90% of patients. Commonly seen problems in ACL reconstruction such as inaccurate graft placement and tunnel widening were found to be consistent with the values in relevant literature. However, we demonstrated that the functional results and the stability of the knee were not related with tunnel widening. This study concludes that the reconstruction of ACL with hamstring tendons and the Transfix technique is reasonably successful, safe and causes low morbidity. Furthermore, we believe that proper graft preparation, accurate tunnel placement, notch-plasty, fixation and rehabilitation program are all as important as the choice of graft and fixation material.     

Temporal change of joint position sense after posterior cruciate ligament reconstruction using multi-stranded hamstring tendons

A total of 29 patients who had undergone posterior cruciate ligament (PCL) reconstruction using multi-stranded hamstring tendons were prospectively followed-up for joint stability and proprioceptive function at a minimum of 24 months after surgery. We measured temporal changes of the posterior laxity by stress radiography and the KT-2000 arthrometer, and we also measured joint position sense for an average of 42 months (range 24–78 months). In terms of results, improvement of joint stability was observed postoperatively and maintained over 2 years after PCL reconstruction, although posterior stability in the reconstructed knee was not identical to the contralateral normal knee. Although joint position sense worsened just after reconstruction, it gradually recovered from 18 months after surgery. However, proprioceptive function after PCL reconstruction did not recover to the same level as in the contralateral normal knee even over 24 months after surgery.     

Long-term results of the Leeds-Keio anterior cruciate ligament reconstruction

This paper discusses the long-term results of the anterior cruciate ligament (ACL) reconstruction with the Leeds-Keio (LK) prosthetic ligament. For this type of reconstruction we used arthrotomy and an arthroscopy-assisted technique. The fixation was obtained with two bone plugs, and the distal portion was also attached with a staple. A postoperative protocol was used with a progressive range of motion and weight bearing after 50 days. We performed 50 LK operations in professional and amateur athletes aged 17–39 years with an isolated anterior instability. We reviewed at follow-up (5–7 years) 37 patients; 8 were lost, and 5 had a subsequent failure. At the Lysholm score the patients were classified: 19 excellent, 13 good, 3 fair, and 2 poor. At the IKDC grading the patients were classified as follows: 2 class A, 22 B, 8 C, and 5 D. The Lachman test was 1+ in 15 patients, 2+ in 7, 3+ in 2, and negative in 13: pivot shift was 1+ in 9, 2+ in 7, 3+ in 2, and negative in 25. Results of the KT 1000 test at 30 Ib side to side was <3 mm in 23 patients, 3–5 mm in 6, 6–10 mm in 6, and >10 mm in 2. In view of the results observed and the progressive deterioration over the years, this procedure should no longer be performed as an ACL substitute.     

Femoral press-fit fixation of the hamstring tendons for anterior cruciate ligament reconstruction

BACKGROUND: Press-fit fixation of patellar tendon-bone anterior cruciate ligament autografts is an interesting technique because no hardware is necessary. For hamstring tendon grafts, no biomechanical data exist of a press-fit procedure. HYPOTHESIS: Press-fit femoral fixation of hamstring tendons is mechanically equivalent to press-fit patellar tendon-bone fixation. STUDY DESIGN: Controlled laboratory study. METHODS: Patellar and hamstring tendons of 30 human cadavers (age, 53.8 +/- 18.0 years) were used. An outside-in press-fit fixation with a knot in the semitendinosus and gracilis tendons and an inside-out and outside-in fixation with the tendons wrapped around a bone block were compared with patellar tendon-bone press-fit fixation in 30 ovine femora. Constructs were cyclically strained and then loaded until failure. Maximum load to failure, stiffness, and elongation during failure testing and cyclical loading were investigated. RESULTS: The maximum load to failure was 561 +/- 309 N for the patellar tendon, 599 +/- 234 N for the semitendinosus/gracilis tendons knot construct, 678 +/- 231 for the semitendinosus/gracilis tendons bone construct inserted outside in, and 339 +/- 236 for the semitendinosus/gracilis tendons bone construct inserted inside out (inferior to the others; analysis of variance, Dunn test, P < .01). Stiffness of the constructs averaged 134 +/- 32 N/mm for the patellar tendon, 124 +/- 21 N/mm for the knot construct, 118 +/- 27 N/mm for the outside-in fixation, and 117 +/- 23 N/mm for inside-out fixation. Elongation during initial cyclical loading was 0.7 +/- 0.6 mm for the patellar tendon, 1.6 +/- 0.5 mm for the knot construct, 1.9 +/- 1.2 mm for the outside-in fixation, and 1.9 +/- 0.9 mm for the inside-out fixation (significantly larger for all semitendinosus/gracilis tendon techniques, P < .05). CONCLUSIONS: Failure loads for the semitendinosus/gracilis tendons bone construct inserted outside in and the semitendinosus/ gracilis tendons knot construct were within the confidence interval of the patellar tendon press-fit fixation. All semitendinosus/ gracilis tendon graft techniques exhibited larger elongation during initial cyclical loading than the patellar tendon graft. There was no difference in stiffness between all techniques. Clinical Relevance: Two of the 3 hamstring press-fit fixation techniques showed loads to failure similar to the patellar tendon fixation. Preconditioning of the constructs is critical. These results must be interpreted with care because of high standard deviations.     

Composite Gore-Tex and autogenoussemitendinosus anterior cruciate ligament reconstruction: Long-term results and historical review

Over the past decade, anterior cruciate ligament reconstruction has evolved into a reproducible procedure withpredictably good results. However, there are still some failures. Some of these failures have obvious mechanical or technical etiologies. For others, the etiology remains unclear. This article examines an explanation for some of these failures and presents a reasonable revision technique to avoid a recurrent failure.     

Bone tunnel enlargement after anterior cruciate ligament reconstruction with the hamstring autograft and endobutton fixation technique A clinical, radiographic and magnetic resonance imaging study with 2 years follow-up

The aim of this study was to describe the contrast-enhanced magnetic resonance imaging (MRI) appearance of bone tunnel enlargement detected on radiography after anterior cruciate ligament (ACL) reconstruction with semitendinosus and gracilis tendon endobutton (STG-endobutton) fixation technique. Fourteen patients with a STG-endobutton ACL reconstruction were examined 3 months (n = 1), 1 year (n = 1) and 2 years (n = 12) postoperatively. An age- and sex-matched group with a bone–patellar tendon–bone (BTB) autograft ACL reconstruction with similar follow-up was taken as control. Data on clinical examination, laxity and isokinetic muscle torque measurements, anteroposterior and lateral view radiography were obtained, and knee scores (Lysholm and Tegner) were collected. Contrast-enhanced MRI was performed in the STG-endobutton group with a 1.5-T imager. There were no statistical differences between the groups with respect to clinical findings, stability tests, or knee scores. In the STG-endobutton group the average femoral and tibial bone tunnel diameter detected on anteroposterior view radiography had increased at 2-year follow-up by 33% and 23%, respectively. On MRI the ligamentous graft itself was not enhanced by the contrast medium whereas periligamentous tissue within and around the STG graft bundles showed mild contrast enhancement. In conclusion, the MRI results suggest that enhancing periligamentous tissue accumulated in and around the STG graft associated with the tunnel expansion. In spite of the significant bone tunnel enlargement observed on the follow-up radiography the STG-endobutton knees were stable and the patients satisfied. Received: 26 January 1999 Accepted: 22 May 1999