Semitendinosus-gracilis Graft Research Articles

Magnetic Resonance Imaging Evaluation of the Integration and Maturation of Semitendinosus-Gracilis Graft in Anterior Cruciate Ligament Reconstruction Using Autologous Platelet Concentrate

To evaluate integration and maturation of semitendinosus-gracilis (STG) grafts in anterior cruciate ligament (ACL) reconstruction with magnetic resonance imaging (MRI) in patients who underwent ACL reconstruction with STG with and without autologous platelet concentrate (APC). A randomized single-blinded evaluator prospective study was performed in 2 consecutive series of patients who underwent reconstruction over a 14-month period: 30 with APC use (group A) and 20 as control subjects (group B). At 6 months, an MRI evaluation was performed, with observation of the graft's maturation and presence or absence of synovial fluid at the tunnel-graft interface. To facilitate interpretation, a scoring scale was designed to evaluate graft integration and maturation. Regarding the presence of synovial fluid at the bone-graft interface, the test was negative in 86.84% of patients in group A and 94.74% in group B. A disorganized autograft signal pattern was found in 2.63% in group A and 5.26% in group B. Signal intensity was considered hypointense in 63.16% in group A and 42.11% in group B, isointense in 34.21% in group A and 52.63% in group B, and hyperintense in 0% in both groups. The final mean score was 4.45 points in group A and 4.2 points in group B (P ≥ .05). Poor integration was found in 2.63% in group A and 5.26% in group B (P = .214). Good integration was found in 97.37% in group A and 94.74% in group B (P = .784). In our consecutive series of patients who underwent ACL reconstruction with STG grafts, 1 group with intraoperative APC use versus a control group, followed up by MRI at 6 months after reconstruction, we did not find any statistically significant benefit in the APC group in terms of integration assessment and graft maturation (ligamentization). Level III, case-control study.

Autologous patellar tendon and quadrupled hamstring grafts in anterior cruciate ligament reconstruction: a prospective randomized multicenter review of different fixation methods

ACL reconstruction with bone patellar tendon bone (BPTB) grafts has been shown to produce dependable results. Recently, reconstructions with double-looped semitendinosus gracilis (DLSG) grafts have become common. The prevailing opinion is that ACL reconstruction with patellar tendon graft produces a more stable knee with more anterior knee pain than DLSG grafts, while the functional results and knee scores are similar. The present study evaluates BPTB grafts fixed with metallic interference screws and DLSG grafts fixed with Bone Mulch Screw on the femur and WasherLoc fixation on the tibia. All else being the same, there is no difference in the outcome between the two grafts and fixation methods. This is a prospective randomized multicenter study. A total of 115 patients with isolated ACL ruptures were randomized to either reconstruction with BPTB grafts fixed with metal interference screws (58 patients) or DLSG grafts (57 patients) fixed with Bone Mulch Screws and WasherLoc Screws. Follow-up was at one and two years; the latter by an independent observer. At two years, one ACL revision had been performed in each group. Eight patients in the DLSG group and one in the BPTB group underwent meniscus surgery in the follow-up period (P = 0.014). Mean Lysholm score at the two year follow-up was 91 (SD +/- 10.3) in the DLSG group and also 91 (SD +/- 10.2) in the BPTB group. Mean KT-1000 at two years was 1.5 mm in the BPTB group and 1.8 mm in the DLSG group (n.s.). At two years, four patients in the BPTB group and three in the DLSG group had a Lachman test grade 2 or 3 (n.s.). More patients in the BPTB group had pain at the lower pole of the patella (P = 0.04). Peak flexion torque and total flexion work were lower in the DLSG group at one year (P = 0.003 and P = 0.000) and total flexion work also at two years (P = 0.05). BPTB ACL reconstruction fixed with interference screws and DLSG fixed with Bone Mulch Screws on the femur and WasherLoc Screws on the tibia produce satisfactory and nearly identical outcomes. Among our patients in the DLSG group, flexion strength was lower, and more patients underwent meniscus surgery in the follow-up period. The BPTB group has more anterior knee pain.

Bandverletzungen des Kniegelenkes

Due to their infrequency, injuries to the PCL are often overlooked. In addition to clinical examination, posterior stress X-rays are crucial in the diagnostic algorithm. The stress X-rays can also provide insight into the frequently associated posterolateral instabilities and the phenomenon of fixed posterior drawers. In severe posterior instabilities an arthroscopic PCL reconstruction using an autologous semitendinosus-gracilis graft is performed. In cases with associated posterolateral instabilities, we perform a posterolateral reconstruction using a modified Larson technique in the same setting. In chronic posterior instabilities and varus deformity, a high tibial osteotomy is performed. Posterior instabilities require specific diagnostic pathways, indications and surgical techniques. Therefore, this instability should only be treated by experienced surgeons at specialized centers.

Comparison Of Landing Mechanics During A Drop Jump In Semitendinosus-gracilis Acl-reconstructed Females And Noninjured Females

Women with different types of anterior cruciate ligament (ACL) reconstruction have shown similar landing mechanics as non-injured women. ACL reconstruction using the Semitendinosus-gracilis (SG) graft is one of the preferred options for ACL reconstruction in women. PURPOSE: To compare knee valgus between non-injured women and women with SG ACL reconstruction during a 60-cm double-legged drop jump. METHODS: Twenty-nine females 21-35 years of age (non-injured =15, weight: 60.25 ± 10.63 Kg, height: 161.24 ± 6.70 cm; SG = 15, weight: 67.20 ± 11.46 Kg, height: 166.92 ± 8.44 cm) participated in this investigation. Participants performed 5 trials of a double-legged drop jump from a 60-cm height box. The double-legged landing task involved landing from the 60-cm drop box and immediately jumping vertically as high as possible (countermovement jump). Reflective markers were attached over bony prominences of both legs according to the model embedded in the software. A static trial was used to estimate each subject's joint centers. Five infrared cameras (120 Hz) were used to capture the trajectory of reflective markers during the drop jump. Knee valgus was defined as the minimum distance between markers placed at the lateral femoral epicondyles during the ground contact phase. The ground contact phase was defined as the moment of initial contact until the participant cleared both feet from the floor during the maximal vertical jump push-off. The average valgus from five trials was used for analysis using an Analysis of Variance (ANOVA) to compare knee valgus among groups. RESULTS: The ANOVA revealed no statistically significant differences (p= 0.842) between groups for knee valgus during the ground contact phase of the drop jump. CONCLUSION: Young women with SG ACL reconstruction presented similar knee valgus as young women without knee surgery on a 60-cm double-legged drop jump. It appears that young women who undergo ACL reconstruction with SG autograft do not experience long term landing mechanics deficits that could predispose them to re-injury. NIH Grants G12RR03051 and 1P20 RR11126, and NSCA Foundation supported this project.

Biomechanical comparison between CentraLoc and Intrafix fixation of quadrupled semitendinosus–gracilis allografts in cadaveric tibiae with low bone mineral density

Supplementary or back-up tibial tunnel fixation of a quadruple semitendinosus–gracilis (STG) graft is often performed when the knee surgeon questions the integrity of intra-tunnel fixation. Back-up fixation devices such as staples however may contribute to increased knee pain and dysfunction. Both primary extra-tunnel and intra-tunnel fixation devices may provide sufficient quadruple STG graft fixation in a tibial tunnel to preclude the need for back-up fixation. This biomechanical study compared the fixation of quadruple STG allografts in standard drilled tunnels prepared in low apparent bone mineral density (BMD) cadaveric tibiae using either an Intrafix device with primary intra-tunnel fixation in a region of predominantly cancellous trabecular bone, or a CentraLoc device with primary extra-tunnel fixation in a region of predominantly cortical bone. The study hypothesis was that the CentraLoc device would display superior fixation in these low apparent BMD cadaveric tibiae. Matched pair tibiae and quadruple STG allografts were divided into two groups of seven specimens each. Extraction drilled tunnels matched allograft diameter. Constructs were pretensioned on a servo hydraulic device between 10 and 50 N for 10 cycles and isometric pretensioned at 50 N for 1 min prior to undergoing 500 loading cycles (50–250 N) and load to failure testing (20 mm/min). The CentraLoc group displayed superior load at failure (448.4 ± 171 N vs. 338.4 ± 119 N, P = 0.04) and survived more loading cycles (410 ± 154 cycles vs. 196 ± 230 cycles, P = 0.04) than the Intrafix group. Most CentraLoc group specimens (6/7, 85.7%) failed by device pullout with intact quadruple STG allograft strands while all Intrafix group specimens (7/7, 100%) failed by slippage of one or more strands ( P = 0.005).

Effects of Early Progressive Eccentric Exercise on Muscle Structure After Anterior Cruciate Ligament Reconstruction

Thigh muscle atrophy is a major impairment that occurs early after reconstruction of the anterior cruciate ligament and persists for several years. Eccentric resistance training has the potential to induce considerable gains in muscle size and strength that could prove beneficial during postoperative rehabilitation. The purpose of this study was to evaluate the effects of progressive eccentric exercise on thigh muscle structure following reconstruction of the anterior cruciate ligament. Beginning three weeks after reconstruction of the anterior cruciate ligament, forty patients were randomly assigned to a program involving either twelve weeks of eccentric exercises or a standard rehabilitation protocol. Patients were matched by surgical procedure, sex, and age. The final series consisted of two cohorts of twenty patients each who had been treated with one of two types of graft (semitendinosus-gracilis or bone-patellar tendon-bone), with ten patients treated with each of the two rehabilitation protocols in each graft cohort. To evaluate changes in muscle structure, magnetic resonance images of the involved and uninvolved thighs were acquired before and after training. The volume and peak cross-sectional area of the quadriceps, hamstrings, and gracilis and the distal portion of the gluteus maximus were calculated from these images. The volume and peak cross-sectional area of the quadriceps and gluteus maximus, in both the involved and the uninvolved thighs and in the patients treated with each type of graft, improved significantly more in the eccentric-exercise group (p < 0.001). The magnitude of the volume change was more than twofold greater in that group. No significant differences in any hamstring or gracilis structural measurements were observed between the rehabilitation groups. However, the volume and peak cross-sectional area of the gracilis were markedly reduced, compared with the pretraining values, in the patients who had undergone reconstruction with the semitendinosus-gracilis graft. Eccentric resistance training implemented three weeks after reconstruction of the anterior cruciate ligament can induce structural changes in the quadriceps and gluteus maximus that greatly exceed those achieved with a standard rehabilitation protocol. The success of this intervention can be attributed to the gradual and progressive exposure to negative work through eccentric exercise, ultimately leading to production of high muscle force.

Anterior Cruciate Ligament Revision Reconstruction

Background The quadriceps tendon is a viable graft source for revision anterior cruciate ligament reconstruction. Purpose To determine the functional results and graft failure rates in knees in which the patellar tendon had been previously harvested or was unavailable, expanded tunnels precluded the use of a semitendinosus-gracilis graft, or patients requested autogenous tissues instead of allografts for revision reconstruction. Study Design Case series; Level of evidence, 4. Methods The authors observed 21 patients for a mean of 49 months postoperatively after revision anterior cruciate ligament reconstruction with a quadriceps tendon graft. The results were determined by KT-2000 arthrometer testing, the Cincinnati Knee Rating System, and the International Knee Documentation Committee Rating System. Fifteen knees required a concurrent procedure, including reconstruction of posterolateral structures in 5 knees, meniscal repairs in 5 knees, and high tibial osteotomy in 2 knees. Results Significant improvements occurred in symptoms (P< .0001), daily activities (P< .05), sports activities (P< .01), and the overall rating scores (P< .0001). Eighteen patients rated their knee condition as improved. Total mean anterior-posterior displacements decreased from 8.4 ± 3.1 mm preoperatively to 2.0 ± 2.3 mm at follow-up (P< .001). On the International Knee Documentation Committee knee ligament rating, 17 knees were graded as normal or nearly normal, 3 were graded as abnormal, and 1 was graded as severely abnormal. Conclusion The revision operation provided reasonable results in this group of complex knees. However, the functional and overall results were inferior to those reported for primary anterior cruciate ligament reconstruction. Many knees (90%) had compounding problems of articular cartilage damage, meniscectomy, varus malalignment, or additional ligamentous injury that most likely affected the results.

Effect of Tibial Tunnel Dilation on Pullout Strength of Semitendinosus-Gracilis Graft in Anterior Cruciate Ligament Reconstruction

This biomechanical cadaver study evaluated the effect of tibial tunnel dilation on the pullout strength of semitendinosus and gracilis tendon grafts in anterior cruciate ligament reconstruction. Fourteen grafts were harvested, and the anterior cruciate ligament was reconstructed in the tibial and femoral tunnels. All femoral tunnels were reamed to the diameter of the graft. In seven knees, the tibial tunnels were reamed to the diameter of the graft. In the remaining seven knees, the tibial tunnels were reamed 2 mm smaller than the diameter of the graft and then serially dilated to the graft size using cannulated smooth dilators. Mechanical testing to graft failure was conducted. All grafts failed by graft pullout from the tibial tunnel. However, mean peak load was significantly higher for the dilated tibial specimens (616 +/- 263 N) than for the reamed specimens (453 +/- 197 N) (P = .0025).

Correlation of interference screw insertion torque with depth of placement in the tibial tunnel using a quadrupled semitendinosus-gracilis graft in anterior cruciate ligament reconstruction

To evaluate the insertion torque of a soft-tissue interference screw in relation to depth of insertion into the tibial tunnel when used for fixation of a quadrupled semitendinosus-gracilis autograft in anterior cruciate ligament reconstruction. Biomechanical cadaver study. Ten quadrupled semitendinosus-gracilis grafts were harvested from fresh-frozen cadaver knees and fixed in donor proximal tibias using 10-mm bioabsorbable interference screws (Arthrex, Naples, FL). A cannulated torque screwdriver was used to measure screw insertion torque at 3 depths in the tibial tunnel: the outer cortex (distal third), the articular surface (proximal third), and between these 2 points (middle third). The mean insertion torques for the distal third, middle third, and proximal third were 8.7, 4.7, and 4.3 in/lb, respectively. The insertion torque was significantly higher at the outer cortex (distal third) than the middle third and proximal third (joint line of the tibial tunnel) ( P < .05). Our results indicate a correlation between insertion torque and depth of placement of bioabsorbable interference screws used for fixation of a semitendinosus-gracilis graft. Lower insertion torque at the articular surface, resulting in lower peak load or pullout strength, may outweigh the proposed benefits of joint-line fixation of a semitendinosus-gracilis graft used for anterior cruciate ligament reconstruction. Studies have suggested that anatomic proximal fixation of ACL grafts in the tibial tunnel produces stability similar to intact knees. The results of our study indicate that lower insertion torque at the articular surface results in lower peak load and pullout strength of the graft, which may outweigh the proposed benefits of joint-line fixation.

Neuromuscular function after anterior cruciate ligament reconstruction with autologous semitendinosus-gracilis graft

Background: The quadrupled autologous semitendinosus-gracilis graft is the first choice of many orthopaedic surgeons when reconstructing the anterior cruciate ligament. The effect that this procedure has on voluntary muscle control remains unclear. The purpose of this study was to evaluate the effect that anterior cruciate ligament reconstruction with autologous semitendinosus-gracilis graft has on voluntary muscle control by assessing subjects’ specificity of muscle action. Methods: The voluntary muscle control of 10 people (seven males, three females) with acute, isolated ACL ruptures was assessed in the days prior to when they underwent anterior cruciate ligament reconstruction with quadrupled autologous semitendinosus-gracilis grafts and after they had returned to play in sports requiring quick changes of direction and jumping (approximately 6 months later). The experimental protocol included the use of an established target-matching protocol that requires subjects to produce and modulate force with fine control, electromyographic recordings from 11 muscles about the knee, and the use of circular statistics to calculate specificity indices that describe the degree of focus (specificity) associated with the activity pattern of each muscle. Data were analyzed by performing pre-surgery and post-return to sports side-to-side comparisons, as well as, pre-surgery to post-surgery ipsilateral comparisons. Results: Diminished specificity of muscle action was observed in the activity patterns of most of the muscles of the subjects’ anterior cruciate ligament deficient knees prior to surgery. The quadriceps muscles were particularly affected. Post-return to sports results indicated that voluntary muscle control had improved in most muscles. There was no significant difference in pre-surgery and post-return to sports semitendinosus and gracilis muscle control. The semimembranosus muscle displayed less specific muscle activity patterns following surgery, which may represent a compensation strategy for minor changes in neuromuscular function. Conclusions: Voluntary muscle control improved in most muscles following ACL reconstruction with semitendinosus-gracilis autografts. Semitendinosus and gracilis muscle control did not appear to be altered significantly by the procedure.

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

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. 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. 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. 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.

Reconstruction of ruptured patellar tendon after total knee arthroplasty: a case report and a description of an alternative fixation method

Patellar tendon rupture after total knee arthroplasty is a rare, but often catastrophic complication. Many different reconstruction techniques of patellar tendon rupture have been described with variable and often discouraging results. A case report with patellar tendon rupture after a total knee arthroplasty is presented. Also, an alternative surgical technique of reconstruction of the patellar tendon using a semitendinosus-gracilis (STG) graft with an interference screw and a staple fixation enabling an immediate mobilization is described.

Injuries of the anterior cruciate ligament: What is state of the art?

BACKGROUND: The anterior cruciate ligament (ACL) is the most commonly injured ligament in the knee. However, there is an ongoing debate of when and how to fix an ACL rupture. METHODS: This article reviews common treatment methods of ACL ruptures. RESULTS: Reinsertion of the ACL does not appear to result in proper ligament healing. There are two methods to reconstruct the ACL: patellar tendon grafts (BTB) and semitendinosus-gracilis grafts (STG). CONCLUSIONS: Ruptures of the ACL should be treated in active people as they require a stable knee. STG grafts seem to have an advantage compared with BTB grafts as far as postoperative pain and complications are concerned. However, competitive athletes will require a BTB, as this graft allows an earlier comeback compared with the STG graft.

Biodegradable screw presents as a loose intra-articular body after anterior cruciate ligament reconstruction

We report a case of intra-articular movement of a broken piece of a poly-L-lactide (PLLA) bioabsorbable interference screw from the femoral tunnel in anterior cruciate ligament (ACL) reconstruction with quadrupled semi-tendinosus and gracilis tendon grafts. Eleven months after initially successful ACL surgery, the patient felt a sudden locking of the knee without associated trauma or injury. The patient experienced pain and swelling episodes after heavy lifting with knee flexion at work, but without symptoms of giving way or locking. On revision arthroscopy, a broken part of a bioabsorbable interference screw was seen in the lateral compartment, which was subsequently removed without incident. The semitendinosus-gracilis graft appeared intact without disruption. After revision surgery, the patient’s recovery was uneventful, with return to activity within a few months. This case further shows the problem of biointerference screw breakage in ACL reconstructive surgery and the need to bury the femoral bioabsorbable interference screw on graft fixation.

Effect of Anterior Cruciate Ligament Reconstruction on the Passé Movement in Elite Dancers

Semitendinosus-gracilis (STG) and patella-tendon-bone (PTB) are frequently selected grafts for anterior cruciate ligament (ACL) reconstruction in dancers. While STG and PTB grafts appear to be similar in restoring acceptable mechanical joint stability, it is not known whether there are alterations in the kinematics of dance movements following these procedures. The present study examined two-dimensional kinematics of trunk-lower extremity coordination in 18 adult professional dancers: six dancers with STG, six with PTB graft ACL reconstruction, and six healthy controls. All dancers with ACL reconstruction had returned to full dancing and performance with no visible asymmetries in their dancing. We examined whether temporal organization and peak velocity of the gesture limb differed between dancers with STG and PTB graft reconstruction and controls when performing the passé. Hip and knee peak angular velocities were slower on the involved limb of STG and PTB dancers compared to controls. Adaptations were seen bilaterally in delayed movement times, shorter deceleration times, and greater number of movement units in the ACL reconstruction groups. These findings suggest that injury to a single joint can affect kinematics throughout the involved and uninvolved lower extremities. The altered movement patterns found in dancers with both types of ACL reconstruction suggest that their control of complex movements may be adaptive in nature.

LONGITUDINAL GAIT ALTERATIONS OF ACL-INJURED INDIVIDUALS RECONSTRUCTED WITH THE HAMSTRING GRAFT

The double loop semitendinosus-gracilis graft (DLSTG) is now common in ACL-reconstruction surgery. Anecdotally, these patients recover faster, particularly early in the rehabilitation phase, compared to B-PT-B patients. Despite widespread use, gait alterations of DLSTG patients have not been presented. The purpose of this study was to quantify joint kinematics of DLSTG reconstructed patients when walking at 6 and 12 weeks post-surgery. Eight DLSTG patients and eight healthy subjects walked at a self-selected pace and at 1.5 m/s, respectively. Video data were collected (60 Hz) to compute hip, knee, and ankle joint kinematics. The appropriate t-test (p ≤ 0.05) was used for specific planned comparisons. At 6 weeks, the DLSTG group exhibited reduced knee joint and greater ankle joint ROM. By 12 weeks, kinematics of the DLSTG group were similar to the controls, except for ankle angle at contact. Results indicate that most gait kinematics of DLSTG patients return to near normal values by 12 weeks. Future study of joint energetics is warranted to evaluate NMS changes underlying the kinematic changes.Table

Anatomic double-bundle posterior cruciate ligament reconstruction using hamstring tendons

Recent biomechanical studies have shown that an anatomic double-bundle posterior cruciate ligament (PCL) reconstruction is superior in restoring normal knee laxity compared with the conventional single-bundle isometric reconstruction. We describe a modification of an endoscopic PCL reconstruction technique using a double-bundle Y-shaped hamstring tendon graft. A double- or triple-bundle semitendinosus-gracilis tendon graft is used and directly fixed with soft threaded biodegradable interference screws. In the medial femoral condyle, 2 femoral tunnels are created inside-out through a low anterolateral arthroscopic portal. First, in 80° of flexion, the double-stranded gracilis graft is fixed with an interference screw inside the lower femoral socket, representing the insertion site of the posteromedial bundle. In full extension the combined semitendinosus-gracilis graft is pretensioned and fixed inside the posterior aspect of the single tibial tunnel. The double- or triple-stranded semitendinosus tendon is inserted in the higher femoral tunnel, presenting the insertion site of the anterolateral bundle. Finally, pretension is applied to the semitendinosus bundle in 70° of flexion and a third screw is inserted. Using this technique, the stronger semitendinosus part of the double-bundle graft, which mimics the anterolateral bundle of the PCL, is fixed in flexion, whereas the smaller gracilis tendon part (posteromedial bundle) is fixed in full extension. Thus, a fully arthroscopic anatomic PCL reconstruction technique is available that may better restore normal knee kinematics as compared to the single-stranded isometric reconstruction.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 17, No 1 (January), 2001: pp 88–97

Anterior Cruciate Ligament Reconstruction Using Hamstrings for a Two-Incision Technique

Summary: Anterior cruciate ligament (ACL) reconstructions are most commonly performed through a single incision using either a patellar tendon or hamstring graft. This technique, however, may be problematic in circumstances such as revision ACL reconstructions or reconstructions in patients with open growth plates. In these cases, a second incision may be needed to avoid prior tunnels or an open physis. Severe patellofemoral disorders may also prohibit the use of autologous patellar tendon harvesting. The two-incision ACL reconstruction technique described incorporates a fourstranded semitendinosus-gracilis graft. The four free tendon ends are fixed proximally in a figure-of-eight fashion with two bicortical screws and soft tissue washers, and the distal looped end is secured with three No. 5 sutures tied to a screw and post. This construct provides graft (2800-4500 N) and fixation strengths (821 N) exceeding that of a 10-mm patellar tendon graft with interference screw fixation. This technique allows for an accelerated rehabilitation program, has low graft harvest morbidity, and allows the freedom necessary for tunnel placement and orientation in complicated reconstructions. For these reasons, this technique should be familiar to those surgeons specializing in knee ligament reconstruction.

Quadrupled semitendinosus-gracilis autograft fixation in the femoral tunnel: a comparison between a metal and a bioabsorbable interference screw

Although semitendinosus-gracilis (SG) grafts for anterior cruciate ligament reconstruction have many potential benefits, effective fixation remains a challenge. This study assessed differences between the maximum pullout forces needed to detach a quadrupled SG graft from a femoral tunnel when secured by either a metal or a bioabsorbable interference screw. Sixteen paired fresh frozen quadrupled SG autografts (x, 8.4 mm; range, 7-10 mm) from 8 donors were anchored into cadaveric femoral tunnels by either a 7-mm metal or a 7-mm bioabsorbable screw after bone mineral density (BMD) assessment and before undergoing a longitudinal 20 mm/min traction force. Statistical analysis compared BMD (gm/cm2), insertional torque (N-m), and maximum load at pullout (N) between screw types. Insertional torques (.28-1.21, N-m range) did not correlate ( P>.05) to BMD or maximum load at pullout (x ± S.D.) 242 ± 90.7 N (metal screw) and 341.1 ± 162.9 N (bioabsorbable screw). Differences did not exist between the maximum load at pullout for bioabsorbable or metal screw fixation ( P = .16). Careful graft preparation, sizing, and matched tunnel placement enables interference fit and fixation capable of reliably withstanding the low- level rehabilitation loads to which the graft is exposed until bony ingrowth occurs. Arthroscopy 1998 Apr;14(3):241-5

Arthroscopically Assisted Reconstruction of the Anterior Cruciate Ligament. A Prospective Randomized Analysis of Three Techniques*

One hundred and twenty-seven patients who had a rupture of the anterior cruciate ligament agreed to participate in a prospective, randomized study of three arthroscopically assisted reconstruction techniques. One hundred and twenty-five patients (125 reconstructions) were evaluated after a mean duration of follow-up of forty-two months (range, two to five years). Group I included forty patients who had a two-incision reconstruction with use of an autogenous semitendinosus-gracilis graft, group II consisted of forty patients who had a two-incision reconstruction with use of an autogenous patellar-ligament graft, and group III included forty-five patients who had a single-incision reconstruction (endoscopic technique) with use of an autogenous patellar-ligament graft. The male-female ratio, age range, level of athletic activity, interval between the injury and the reconstruction, previous operative procedures, and associated injuries were similar in all three groups. The same postoperative rehabilitation protocol was followed for all patients. Testing with a KT-2000 arthrometer at maximum manual force was done at the follow-up evaluation; the difference in laxity between the involved knee and the contralateral knee was three millimeters or less in thirty-three patients (83 per cent) in group I, thirty-seven patients (93 per cent) in group II, and thirty-nine patients (87 per cent) in group III. A difference of two millimeters or less was found in thirty patients (75 per cent) in group I, thirty-one patients (78 per cent) in group II, and thirty-five patients (78 per cent) in group III. Thirty-five patients (88 per cent) in group I, thirty-eight patients (95 per cent) in group II, and forty patients (89 per cent) in group III returned to at least the same level of athletic activity. Four grafts (two in group I and two in group II) failed as a result of trauma. There was one additional failure in groups I and III, as evidenced by a difference of nine and seven millimeters, respectively, on instrumented testing of laxity. The significant findings were that no knee was rated D according to the system of the International Knee Documentation Committee (p < 0.002, 94 per cent confidence level) and that fewer additional operative procedures were done on patients in group III (p < 0.08). Also, it was found that the patients in group II returned to a greater level of athletic activity (p < 0.02) and that a higher percentage of the patients in this group had a difference of three millimeters or less on testing with the KT-2000 arthrometer than in the other two groups (p < 0.08). However, with the numbers available, there were no significant differences in the over-all outcome among the three groups (p > 0.1). Importantly, the rate of failure was not greater and the outcomes were not less satisfactory for the late reconstructions than they were for the acute reconstructions (those performed less than three weeks after the injury), including those done with an autogenous semitendinosus-gracilis graft in a chronically unstable knee.