Tripled semitendinosus anterior cruciate ligament reconstruction with Endobutton fixation: a 2-3-year follow-up study of 35 patients

The interposition of soft tissue between the cortical button and femoral lateral cortex significantly increases button migration but does not negatively affect knee stability and clinical outcome

BACKGROUND

In clinical practice, soft tissue interposition may occur during femoral graft fixation. Soft tissue interposition between the lateral femoral cortex and the cortical button may affect graft tension and related longitudinal graft motion in the tunnel. We aimed to investigate the effect of soft tissue interposition on button migration and clinical outcomes in anatomical single-bundle anterior cruciate ligament reconstruction.

METHODS

Eighty-four patients aged 18-40 years, who underwent anatomical single-bundle anterior cruciate ligament reconstruction with quadruple hamstring autograft were included. Patients were divided into two groups as Group 1 (n = 32) with soft tissue interposition between the cortical button and cortex, and Group 2 (n = 52) without soft tissue interposition. At the one-year follow-up visit, the anteroposterior knee stability of the patients was evaluated using the Lachman test and KT-2000 arthrometer, and rotational stability was assessed with the pivot shift test. The Lysholm knee score was used to evaluate the functional outcome of the patients. Relationship between tissue interposition and clinical outcome, and button migration was examined.

RESULTS

Button migration was observed in 12 patients in Group 1 (37.5%) and two patients (3.84%) in Group 2 (p < 0.001). However, no significant difference was observed between patients with and without tissue interposition or those with and without button migration regarding knee stability parameters and clinical outcome (p < 0.05).

CONCLUSIONS

Postoperative tissue interposition is found to be associated with cortical button migration during the follow-up. However, it does not affect the clinical outcome.

Mechanical assessment of tripled hamstring tendon graft when using suspensory fixation for cruciate ligament reconstruction

BACKGROUND

Tripling semitendinosus tendon for ACL graft preparation facilitates creation of longer and thicker grafts. Our objective was to evaluate the mechanical difference between tripled tendon grafts, prepared by three methods, by comparing with quadrupled tendon graft.

METHODS

Bovine hind-foot hoof extensors were allocated to four groups. Group I had quadrupled graft construct. Tripled graft constructs were prepared by passing the tendon to the Endobutton CL loop and stitching the third strand to (i) the loop (in Group II) or (ii) to one strand(in Group III) or (iii)to loop and both tendon strands (in Group IV). The constructs were preloaded from 10 to 50 N at 0.1 Hz for 10 cycles, followed by 1000 cycles of sinusoidal loading between 50 and 250 N at a frequency of 0.5 Hz. The specimens were then subjected to load to failure test at the rate of 50 mm/min. Displacement with cyclic loading, load at failure and the mode of failure were noted.

RESULTS

The load at failure was 957 ± 23.30 N (Mean ± Standard Deviation) in Group I, 590.8 ± 24.40 N in Group II, 682.6 ± 59.28 N in Group III and 963.4 ± 21.72 N in Group IV. The displacement with cyclic loading was 1.13 ± 0.11 mm in Group I, 4.908 ± 0.55 mm in Group II, 1.822 ± 0.55 mm in Group III and 1. 126 ± .018 mm in Group IV. There was no significant difference between the Groups I and IV with respect to the load at failure and displacement (p > 0.05). The values were significantly different in Group II and Group III (p < 0.01), when compared to groups I and IV.

CONCLUSIONS

Tripled grafts have mechanical properties equivalent to quadrupled grafts only when the three strands are sutured together. Caution may be warranted when using suspensory fixation device with tripled tendons and the third strand must be securely attached to the loop of fixation device and to the other two strands.

Tripled semitendinosus with single harvesting is as effective but less invasive compared to standard gracilis-semitendinosus harvesting

Introduction

The anterior cruciate ligament (ACL) reconstruction with pes anserinus tendons has been increasingly used throughout the last years. Although less invasive compared to other autologous grafts, a reduction of internal rotation and flexion strength after gracilis and semitendinosus harvesting has been reported. Harvesting one tendon instead of two from the pes anserinus can reduce the deficit of the knee flexor strength and improve the functional recover without weakening the reconstructed ligament.

Methods

Forty-five (45) patients who had ACL reconstruction with triple semitendinosus graft (ST3) have been compared with other 45 similar patients who had ACL reconstruction with double gracilis-semitendinosus tendons (GST). Patients have been evaluated at a minimum of 12 months after surgery: IKDC scale, KT-1000, One Leg Hop Test for the objective stability; Isokinetic test for the strength; Tegner scale, Lysholm and IKDC subjective evaluation form for the function.

Results

No differences have been detected between the groups for the objective item assessed. Male patients' subjective IKDC score was statistically better for the ST3 group. Recreational soccer players showed a higher Lysholm and subjective IKDC score in ST3 group compared to GST group. There was no difference regarding the return to sport.

Conclusion

ST3 guarantees the same objective knee stability compared to a GST. It is a viable option for ACL reconstruction that allows a better preservation of patient's anatomy and a less invasive harvesting surgery.

Level of evidence

III b, case control study.

Isokinetic Identification of Knee Joint Torques before and after Anterior Cruciate Ligament Reconstruction

The aim of this study was to evaluate the serial change of isokinetic muscle strength of the knees before and after anterior cruciate ligament reconstruction (ACLR) in physically active males and to estimate the time of return to full physical fitness. Extension and flexion torques were measured for the injured and healthy limbs at two angular velocities approximately 1.5 months before the surgery and 3, 6, and 12 months after ACLR. Significant differences (p ≤ 0.05) in peak knee extension and flexion torques, hamstring/quadriceps (H/Q) strength ratios, uninvolved/involved limb peak torque ratios, and the normalized work of these muscles between the four stages of rehabilitation were identified. Significant differences between extension peak torques for the injured and healthy limbs were also detected at all stages. The obtained results showed that 12 months of rehabilitation were insufficient for the involved knee joint to recover its strength to the level of strength of the uninvolved knee joint. The results helped to evaluate the progress of the rehabilitation and to implement necessary modifications optimizing the rehabilitation training program. The results of the study may also be used as referential data for physically active males of similar age.

Electromechanical delay of the knee flexor muscles after anterior cruciate ligament reconstruction using semitendinosus tendon

The purpose of the study was to evaluate whether using only the semitendinosus as a tripled short graft would affect the electromechanical delay (EMD) of the knee flexors. EMD was evaluated in volunteers (N = 15) after they had undergone surgery for anterior cruciate ligament (ACL) reconstruction where the semitendinosus tendon alone was used as a graft. The results were compared with the intact leg and healthy controls (N = 15). After warming up, each subject performed four maximally explosive isometric contractions on an isokinetic dynamometer. Torques were measured by the dynamometer, while the electrical activity of the semitendinosus and biceps femoris muscles was detected using surface electromyography. EMD was found to be significantly increased (p = 0.001) in patients who had undergone ACL reconstruction compared to the controls. On the contrary, no significant differences (p = 0.235) were found for the biceps femoris muscle between the two groups. Similar results were found when the study group was compared with the intact leg group (p = 0.027 for semitendinosus and p = 0.859 for biceps femoris). Harvesting the semitendinosus tendon increases the EMD for the semitendinosus muscle but does not influence the EMD outcomes for the biceps femoris muscle.

Comparison of femoral tunnel length between transportal and retrograde reaming outside-in techniques in anterior cruciate ligament reconstruction

PURPOSE

To evaluate the accuracy of intraoperative femoral tunnel length measurement and to compare this between the transportal (TP) and outside-in (OI) techniques for double-bundle (DB) anterior cruciate ligament (ACL) reconstruction.

METHODS

Eighty patients underwent a DB ACL reconstruction using either the TP or the OI technique. The participants were randomized to either a TP group (I, 40 cases) or a OI group (II, 40 cases). The intraoperatively measured femoral tunnel length was recorded, and the postoperative femoral tunnel length was measured using computed tomography with OsiriX(®) imaging software.

RESULTS

The mean femoral tunnel lengths measured intraoperatively in Group II (38.9 ± 3.0 mm for anteromedial [AM], 39.3 ± 3.4 mm for posterolateral [PL]) were significantly longer than those of Group I (34.8 ± 2.7 mm for AM, 36.0 ± 3.2 mm for PL) (P < 0.001). The mean AM femoral tunnel length measured postoperatively in Group II (33.3 ± 3.8 mm) was significantly longer than that in Group I (31.1 ± 2.9 mm) (P = 0.006). The mean intraoperatively measured femoral tunnel length was significantly longer than that measured postoperatively in Groups I and II (P < 0.001).

CONCLUSION

After anatomic DB ACL reconstruction, the femoral tunnel length of the OI technique measured intraoperatively (AM/PL) and postoperatively (AM) was longer than those of the TP technique. The femoral tunnel length measured intraoperatively was longer than that measured postoperatively in both TP and OI technique. This study may help surgeons to measure femoral tunnel length accurately in anatomic DB ACL reconstruction with suspensory fixation device.

Intratunnel versus extratunnel fixation of hamstring autograft for anterior cruciate ligament reconstruction

PURPOSE

To determine which is more effective: intratunnel or extratunnel anterior cruciate ligament soft-tissue graft fixation. A secondary purpose was to determine whether groups displayed differing relations between objective International Knee Documentation Committee (IKDC) grade and the timing of full weight bearing (FWB), jogging/running, and return to sports. The study hypotheses were that intratunnel fixation would display a greater percentage of normal or nearly normal objective IKDC grades and enable earlier FWB, return to jogging/running, and return to sports.

METHODS

We performed a systematic review of prospective, Studies with Level I or II evidence published from 2000 to 2011 with at least 2 years' follow-up that used interference screw hamstring autograft fixation (intratunnel group) or button, staple, or post hamstring autograft fixation (extratunnel group) for primary anterior cruciate ligament reconstruction. We also compared IKDC grades; Tegner and Lysholm scores; instrumented anterior laxity and pivot-shift test findings; timing of FWB, jogging/running, and return to sports; and modified Coleman Methodology Scores.

RESULTS

The groups showed comparable modified Coleman Methodology Scores, objective IKDC grades, Lysholm and Tegner scores, instrumented anterior laxity and pivot-shift test findings, and return-to-sports timing. The intratunnel group displayed earlier FWB and jogging/running; however, return-to-sports timing did not differ between groups. Early FWB and the percentage of patients with normal or nearly normal objective IKDC grades were directly related for the extratunnel group.

CONCLUSIONS

Patients who received intratunnel fixation were released earlier to FWB and jogging/running, supporting the study hypotheses. Groups did not differ in return-to-sports timing or objective IKDC grades, not supporting the study hypotheses. Early FWB in the extratunnel group was related to a greater percentage of patients having normal or nearly normal objective IKDC grades. Return-to-sports timing and having a normal objective IKDC grade were related in both groups; however, this relation was stronger with intratunnel fixation.

LEVEL OF EVIDENCE

Level II, systematic review of Level I and II studies.

Femoral seating position of the EndoButton in single incision anterior cruciate ligament reconstruction: an anatomical study

Arthroscopic EndoButton fixation of anterior cruciate ligament (ACL) grafts over the femoral cortex has become popular in recent years. However, elongation of fixation materials has lead to tunnel enlargement, graft tunnel motion and instability. Synovial fluid passages along femoral tunnels following ACL reconstruction may result in destruction of tissues. The purpose of the present study was to identify the seating position of the EndoButton in regard to the boundaries of the knee capsule in single-incision arthroscopic ACL reconstruction. A total of 20 cadaveric knees were dissected and arthroscopic drill guides were used to create tibial and femoral tunnels. The distances between the exit points and boundaries of the suprapatellar bursa at three different degrees of knee flexion were measured. The average distances from the exit points to the superior boundaries of the suprapatellar bursa were 6.89 +/- 5.40 mm (range, 16.87-1.21). However, in knee flexion of greater than 90 degrees , tunnel exits were placed below the superior boundaries of the suprapatellar bursa (-7.08 +/- 3.69 mm, range, -3.24 to -12.87). In order to place the EndoButton extraarticularly, a safe degree of knee flexion during femoral tunnel drilling was defined as 80 degrees .

Return to Sports After Anterior Cruciate Ligament Reconstruction – A Review of Patients with Minimum 5-year Follow-up

Introduction: It is difficult to counsel the anterior cruciate ligament (ACL) deficient patient considering surgical reconstruction on the likelihood of eventual return to sports as information on this is lacking, especially in the Asian context. We wanted to determine how many of our patients who had ACL surgery returned to their previous levels of sports, 5 years after their surgery. For those that had not returned to their previous levels of sports, we wanted to identify their reasons for not doing so. Materials and Methods: Based on our inclusion criteria of a minimum 5-year follow-up after primary ACL reconstruction, 146 patients were identified for assessment. Sixty-four patients were successfully recalled. The mean age of our patients was 24.8 years (range, 18 to 40). The patients completed the Lysholm Knee, Tegner activity and the Subjective International Knee Documentation Committee (IKDC) questionnaires. Clinical examination of the operated knee was performed according to the Objective IKDC evaluation form and with a KT-1000 arthrometer. Results: The mean Lysholm score was 85.2 and the mean subjective IKDC score was 79.5. 81.2% of our patients had normal or nearly normal knees (IKDC A or B) with the remaining 18.8% at IKDC grade C. The mean side-side difference for anterior translation using the KT-1000 arthrometer was 1.2 mm. The median pre-injury Tegner activity level was 7 and the median 5-year post-surgery Tegner activity level was 6. Nineteen patients did not return to their pre-injury sports levels because of social reasons and were excluded. From the remaining 45 patients, 28 patients (62.2%) returned to their previous level of sports and 17 patients (28.8%) did not return to their previous level of sports. Of whom, 9 (20%) said that they did not return due to fear of re-injury and the remaining 8 (17.8%) said they had not returned because of knee instability and pain. At 5 years, the subgroup of patients who had returned to sport had the best scores: Lysholm (88.5), subjective IKDC (84.6) and IKDC Grade A&B (89.3%). When we compared this with the subgroups that did not return to sport because of fear of re-injury and because of an unstable knee, we found that the difference in knee outcome scores between these 3 groups were statistically significant. Conclusion: Sixty-two per cent of our patients returned to their previous level of sport at 5 years after ACL reconstruction. Fear of re-injury is an important psychological factor for these patients not returning to sports. Our results would allow the attending surgeon to counsel the ACL deficient patient who is considering surgical reconstruction the likelihood of eventual return to sports. Key words: Ligament reconstruction, Return to sports

Peripheral versus aperture fixation for anterior cruciate ligament reconstruction

Because both the young and aging population are showing increasing interest in sports participation, the number of sports related injuries and in particular anterior cruciate ligament (ACL) injuries have been increasing. Because of these injuries much time and energy has been focused on ACL reconstruction in order to return these individuals to their optimal level of participation in their sport. This article explores and reviews the concepts of ACL fixation location and how this affects the ultimate outcome of this reconstructive procedure.

Bi-socket ACL reconstruction using hamstring tendons: high versus low femoral socket placement

To clarify the importance of the femoral socket location in bi-socket Anterior cruciate ligament (ACL) reconstruction. Subjects included 261 patients with an average age of 26 years who received ACL reconstruction via the high-femoral socket procedure (Group H) and 43 patients with an average age of 29 years who received ACL reconstruction via the low-femoral socket procedure (Group L) with a minimal follow-up of 24 months. In Group H, the femoral sockets were created at 1:00 or 11:00 and 2:00-2:30 or 9:30-10:00 of the intercondylar notch. In Group L, the two femoral sockets were drilled at 2:00 or 10:00 and 3:00 or 9:00. For the tibial side, a single tunnel was made at the center of the footprint. Evaluation was performed based on the IKDC Knee Examination Form. While 137 knees (52%) were graded as normal, 100 (38%) as nearly normal, 8 (3%) as abnormal, and 2 (1%) as severely abnormal with 14 (5%) re-injury in Group H, 38 knees (74%) were graded as normal, and 7 (16%) as nearly normal with 3 (7%) re-injury in Group L, showing a better subjective evaluation (P = 0.007). The average side-to-side differences in anterior laxity at manual maximum force with the KT-1000 were 1.1 +/- 1.6 mm for Group H and 1.0 +/- 1.6 mm for Group L without statistically significant differences excluding re-injured cases. There were 204 patients (83%) from Group H and 33 (83%) from Group L with values between -2 and 2 mm, while 228 (92%) patients from Group H and 38 (95%) from Group L had values distributed between -3 and 3 mm. While the bi-socket ACL reconstruction provided objectively satisfactory clinical outcomes in more than 90% of the patients, the low-femoral socket placement was found to subjectively achieve better outcomes.

Complications following hamstring anterior cruciate ligament reconstruction with femoral cross-pin fixation

Cross-pin fixation of hamstring grafts for anterior cruciate ligament reconstruction was developed with hopes of improving on potential problems associated with interference screw and button fixation methods. However, cross-pins are a relatively new method of graft fixation and there are limited data on this technique. We report 2 cases in which reoperation was necessary after complications associated with cross-pin fixation. In one case, the cross-pin was left too proud and in the other it penetrated the medial side of the femur and was prominent. Surgeons who use cross-pin fixation should pay close attention so as not to leave the cross-pin proud laterally or medially to avoid the necessity of reoperation for hardware removal.

Stability results of hamstring anterior cruciate ligament reconstruction at 2- to 8-year follow-up

PURPOSE

The purpose of this study was to test the hypothesis that hamstring (HS) anterior cruciate ligament (ACL) reconstructions using EndoButton (Smith & Nephew, Andover, MA) femoral and whipstitch/screw tibial fixation can produce a high rate of objective stability in a population of reconstructed patients with low morbidity.

TYPE OF STUDY

Case series.

METHODS

We retrospectively reviewed 153 consecutive primary HS ACL reconstructions in skeletally mature patients without other ligament reconstructions. All knees had EndoButton femoral and whipstitch/screw tibial fixation; 139 patients were located and 133 were tested. Thirteen were geographically distant and tested subjectively only. Evaluations included KT-1000 testing; radiographs; and Noyes, Lysholm, and Single Assessment Numeric Evaluation (SANE) ratings. Follow-up was 24 to 104 months (mean, 54.4 months).

RESULTS

There were no graft failures. No patient had rupture of an implanted graft. No patient had repeat surgery for instability; 96.9% of reconstructions had maximum manual side-to-side differences of < or =3 mm, 85.7% had < or =2 mm; 3% of the knees had a 4-mm difference; none had > or =5-mm difference. There was no objective stability difference between male and female patients and no deterioration in results with increasing follow-up time. Median ratings were: Noyes, 94; Lysholm, 94.5; and SANE, 90. Radiographs showed that no EndoButtons had migrated. No EndoButton or tibial screw had to be removed due to symptoms from the implant. One hundred eighteen of 120 patients had full extension; the other 2 patients had a 2 degrees flexion loss. One patient required repeat arthroscopy for arthrofibrosis but had full range of motion at follow-up. There were no deep knee infections. One patient had a superficial wound infection requiring intravenous antibiotics. One patient had a calf deep vein thrombosis that resolved with treatment.

CONCLUSIONS

Hamstring ACL reconstructions can produce (1) reliable, durable stability in both males and females with no graft failures, (2) good clinical ratings, (3) excellent range of motion, and (4) low morbidity, without hardware problems.

LEVEL OF EVIDENCE

Level IV, Case Series.

Rehabilitation following anterior cruciate ligament injury: current recommendations for sports participation

Knee ligament injuries often result in a premature end to a career in sports. The treatment after rupture of the anterior cruciate ligament (ACL) may be operative or conservative. In both cases, the goal is to reach the best functional level for the patient without risking new injuries or degenerative changes in the knee. Return to high level of athletic activity has been an indicator of treatment success. Rehabilitation is an important part of the treatment. Knowledge of healing processes and biomechanics in the knee joint after injury and reconstruction, together with physiological aspects on training effects is important for the construction of rehabilitation programmes. Current rehabilitation programmes use immediate training of range of motion. Weight bearing is encouraged within the first week after an ACL reconstruction. Commonly, the patients are allowed to return to light sporting activities such as running at 2-3 months after surgery and to contact sports, including cutting and jumping, after 6 months. In many cases, the decisions are empirically based and the rehabilitation programmes are adjusted to the time selected for returning to sports. In this article, some criteria that should be fulfilled in order to allow the patient to return to sports are presented. Surgery together with completed rehabilitation and sport-specific exercises should result in functional stability of the knee joint. In addition, adequate muscle strength and performance should be used as a critical criterion. Other factors, such as associated injuries and social and psychological hindrances may also influence the return to sports and must be taken into consideration, both during the rehabilitation and at the evaluation of the treatment.

Dropping of an EndoButton into the knee joint 2 years after anterior cruciate ligament repair using proximal fixation methods

One of the most discussed subjects regarding anterior cruciate ligament (ACL) repair methods is femoral fixation. One of the materials often used for fixation in recent years is the EndoButton (Acufex Microsurgical, Mansfield, MA), which provides rapid and secure fixation. Although many reports about femoral fixation with EndoButton have been published, insufficient information is available on possible complications. We have used 240 EndoButtons in our clinic for ACL repairs since 1997. The goal of this study was to report a case of ACL repair with an EndoButton, in which we experienced a complication. In this case, the EndoButton dropped into the knee joint after 2 years.

Second-look arthroscopy of anterior cruciate ligament grafts with multistranded hamstring tendons

PURPOSE

The purpose of this study was to clarify the fate of intra-articularly transplanted multistranded hamstring tendon grafts used for anterior cruciate ligament (ACL) reconstruction.

TYPE OF STUDY

Consecutive samples.

METHODS

The subjects were 153 patients (156 knees) with a mean age of 24 years, who had been evaluated as experiencing clinical success. The patients consented to undergo second-look arthroscopy after ACL reconstruction with multistranded autogenous hamstring tendon grafts at 5 to 51 months previously. Ninety-six knees were surgically treated with the single-socket procedure, and the remaining 60 were treated with the bisocket procedure. None of the patients complained of instability of the index knee. The mean side-to-side difference at manual-maximum force in anterior displacement by KT-1000 on 107 patients was 1.2 +/- 1.1 mm (-1 to 4 mm). Arthroscopic evaluation was performed focusing on tension and thickness dividing into 3 groups based on the postoperative period. The chi-square and Mann-Whitney U tests were used for statistical analysis.

RESULTS

A total of 139 grafts (89%) were evaluated as taut and 17 (11%) as mildly lax or lax. Fifty-three (34%) showed some partial tear, and the other 103 (66%) appeared thick without partial tear. The percentage of mildly lax or lax grafts in the group of patients older than 2 years was higher than that in patients younger than 1 year, and no significant difference was found among the groups in the percentage of partially torn grafts. The patients with mildly lax or lax grafts showed statistically higher KT values, while those with partially torn grafts did not. No statistically significant difference was seen in any of these findings between the 2 procedures, although the bisocket procedure tended to show better tension or thickness.

CONCLUSIONS

Arthroscopically, 11% of the hamstring ACL grafts showed looseness and 34% had partial tear in the clinically successful knees.

LEVEL OF EVIDENCE

Level IV in therapeutic studies investigating the results of treatment.

Tunnel enlargement and changes in synovial fluid cytokine profile following anterior cruciate ligament reconstruction with patellar tendon and hamstring tendon autografts

There is growing evidence that cytokines such as tumor necrosis factor (TNF) alpha, interleukin (IL) 1beta, IL-6, bone morphogenetic proteins (BMP), and nitric oxide (NO) play an important role in the pathogenesis of bone tunnel enlargement following anterior cruciate ligament (ACL) reconstruction. Furthermore, the release of these mediators has been considered a possible reason for the higher incidence of bone tunnel enlargement following hamstring tendon (HST) than following patellar tendon (PT) ACL reconstruction observed in several studies. In this investigation synovial fluid samples from 13 patients were collected immediately before (24+/-7 days after ACL rupture) and 7 days after ACL surgery and values of TNF-alpha, IL-1beta, IL-6, NO, and BMP-2 were analyzed. Furthermore, the incidence of bone tunnel enlargement was assessed using radiographs 38+/-7 weeks after surgery. Six patients underwent autologous HST ACL reconstruction, and in seven patients an PT autograft was used. In the overall patient population there were significantly higher synovial fluid concentrations of IL-6 and BMP-2 postoperatively than preoperatively; TNF-alpha showed a trend towards lower postoperative levels while IL-1beta and NO remained unchanged. The concentrations of NO, TNF-alpha, and IL-6 found in the present study were clearly higher than normal values given in the literature. Assessment of bone tunnel enlargement revealed an average increase in tibial tunnel width of 28.4+/-3.1% with comparable values for HST and PT ACL reconstructions. There was no significant correlation between bone tunnel enlargement and postoperative synovial fluid concentrations of TNF-alpha, IL-1beta, IL-6, NO, and BMP-2. However, all patients with bone tunnel enlargement had higher postoperative concentrations of TNF-alpha, IL-6, and NO in the synovial fluid. There were no significant differences in concentrations between HST and PT groups. In conclusion, we observed an association between tibial bone tunnel enlargement and elevated synovial fluid concentrations of IL-6, TNF-alpha, and NO 7 days after ACL surgery indicating the potential involvement of these biological mediators in the pathogenesis of bone tunnel enlargement. However, there was no difference between HST and PT ACL reconstructions regarding synovial fluid contents of IL-6, TNF-alpha, IL-1beta, NO, and BMP-2, suggesting a comparable biological response between these autografts following their use in ACL reconstruction.

Anterior cruciate ligament reconstruction with a four-strand hamstring tendon autograft

BACKGROUND

In this study, we analyzed the clinical outcomes at a minimum of two years following reconstruction of the anterior cruciate ligament with use of a four-strand hamstring tendon autograft in patients who had presented with a symptomatic torn anterior cruciate ligament.

METHODS

One hundred and twenty-two consecutive patients who had an isolated, symptomatic anterior tibial subluxation associated with rupture of the anterior cruciate ligament were treated with reconstruction of the anterior cruciate ligament with a four-strand autologous semitendinosus-gracilis tendon graft. One surgeon performed all of the operations. Prior to surgery and at the follow-up examination, physical findings and functional scores were recorded and knee radiographs were analyzed. Following surgery, a six-month rehabilitation regimen was implemented.

RESULTS

Eighty-five patients (70%) were available for follow-up, which included physical examination, scoring of function, KT-1000 arthrometric testing, and radiographs, at a mean of twenty-eight months. Seventy-six (89%) of the patients had negative Lachman and pivot shift tests. The mean Lysholm score improved from 55 points preoperatively to 91 points at the time of follow-up (p < 0.01). The mean Tegner score improved from 5 to 6 points (p < 0.01). Sixty-five patients had <3 mm of knee translation on arthrometric testing, but six patients with marked laxity were not tested. Three patients (4%) had a positive pivot shift test but had no history of additional trauma to the knee. Six patients (7%) had a traumatic rupture of the graft, occurring at a mean of 10.7 months postoperatively. Assessment of the follow-up radiographs demonstrated no evidence of progressive degenerative change compared with the appearance on the preoperative radiographs. However, tunnel expansion was noted in all patients. The tibial tunnel expanded a mean of 17% (range, 0% to 32%), and the femoral tunnel expanded a mean of 29% (range, 0% to 40%).

CONCLUSIONS

Reconstruction of the anterior cruciate ligament with use of a four-strand hamstring tendon autograft eliminated anterior tibial subluxation in 89% of patients who were examined at a minimum of two years postoperatively. The overall rate of failure was 11%. The functional knee scores were significantly increased at the time of follow-up, but these results did not correlate with the results of knee arthrometric testing.

Bone-patellar tendon-bone grafts for anterior cruciate ligament reconstruction: an in vitro comparison of mechanical behavior under failure tensile loading and cyclic submaximal tensile loading

BACKGROUND

Secure fixation is an important factor in the success of anterior cruciate ligament reconstruction.

HYPOTHESIS

There is no difference in the mechanical behavior of reconstructions from method of fixation or method of testing.

STUDY DESIGN

Controlled laboratory study.

METHODS

Anterior cruciate ligament reconstructions were performed with bone-patellar tendon-bone grafts in 48 human cadaveric knees. Three different fixation methods (Endobutton, interference screw, suture-post fixation) were compared under failure tensile loading and cyclic submaximal tensile loading.

RESULTS

No difference was observed in ultimate load among the three techniques. Stiffness of the grafts was significantly lower for the suture technique than for the interference screw technique. Cyclic loading revealed significantly different failure rates: 0% of the Endobutton, 38% of the interference screw, and 100% of the suture-post groups. The relative movement of the femoral bone plug and the migration of the bone plug out of the femoral canal were lowest in the interference screw group.

CONCLUSIONS

The suture-post fixation is not recommended. The interference screw technique showed the best results, but results were age-dependent, suggesting its best use is in younger patients. The Endobutton technique is recommended for older patients.

CLINICAL RELEVANCE

Results of testing are useful to the surgeon in making a choice of reconstruction technique.