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

No Difference in Bone Tunnel Enlargement and Clinical Outcome between Cortical Suspension and Hybrid Femoral Fixation in Hamstring Anterior Cruciate Ligament Reconstruction

OBJECTIVE

The best method for femoral fixation in anterior cruciate ligament reconstruction (ACLR) remains controversial. The study assesses the bone tunnel enlargement and clinical outcome in hamstring ACLR using cortical suspension or hybrid (cortical suspension and compression) femoral fixation.

METHODS

From January 2010 to December 2021, 102 patients who underwent quadruple hamstring ACLR using cortical suspension (39 patients) or hybrid (63 patients) fixation on the femoral side were retrospectively analyzed. Clinical evaluation was conducted using the international knee documentation committee score, the Lysholm score, the Tegner activity level scale, the knee injury and osteoarthritis outcome score (quality of life score), the Lachman test, and the side-to-side difference by the KT-1000 arthrometer. The complications after the surgery were also evaluated. These data were compared at baseline and last follow-up. The diameters of the femoral tunnel were calculated at three sites: the width of the entrance of the femoral tunnel, 1 cm proximal to the entrance of the femoral tunnel and the largest diameter of the femoral tunnel on magnetic resonance imaging (MRI) coronal images. Bone tunnel widening data were contrasted between MRI images conducted at least 2 years and within 2 weeks after surgery. The morphology of bone tunnel enlargement was also observed and recorded. The categorical parameters were analyzed using the χ2-test and Fisher's exact test. The continuous variables conforming to a normal distribution were analyzed using Student's t-test, and the Mann-Whitney U-test was undertaken between the two groups without normal distribution.

RESULTS

Both cortical suspension and hybrid femoral fixation in quadruple hamstring ACLR achieved significantly improved patient-reported outcome scores and knee stability compared to preoperative data. However, no significant differences were found between these two methods in clinical evaluations, postoperative complications, and patient-reported outcome scores. Although the mean diameter of the enlarged bone tunnel was lowered by an additional bioabsorbable interference screw fixation near the joint line, a statistically insignificant difference was found between the hybrid and cortical suspension fixation on the femoral side. There was no statistical difference in the distribution of enlarged bone tunnel morphology between groups.

CONCLUSIONS

No significant difference was found in the bone tunnel enlargement and clinical outcome between cortical suspension and hybrid femoral fixation in ACLR using hamstring autograft.

Short graft anterior cruciate ligament reconstruction: Current concepts

Short graft anterior cruciate igament reconstruction is increasing in popularity for performing a primary ACLR. The short graft coupled with the all-inside technique using closed sockets and suspensory fixation at both femoral and tibial ends are its defining features. The outcomes of this technique have been comparable to well established transportal ACLR techniques. It has the benefits of preserved hamstring strength and less pain attributed to transtibial drilling. However, there is a learning curve involved and will require time before mastery of the technique. Furthermore, in combined osteotomy or multiligament surgery, the use of short graft anterior cruciate ligament reconstruction with sockets preserve bone stock and the single tendon harvest spares the other tendons for use in other ligament reconstruction.

The Bone Bridge for Tibial ACL Graft Fixation: A Biomechanical Analysis of Different Tibial Fixation Methods for ACL Reconstruction

Background

The tibial fixation site is considered the weak link in anterior cruciate ligament (ACL) reconstruction, and conflicting results regarding the biomechanical properties of various fixation methods have been reported.

Purpose

To examine knots tied over a bone bridge and its biomechanical properties as a suitable tibial fixation method in ACL reconstruction.

Study Design

Controlled laboratory study.

Methods

We divided 40 fresh-frozen porcine tibiae into 4 equal groups to evaluate flexor tendon grafts set with standard tibial fixation techniques: (1) bone bridge (BB group), (2) suspension button (SB group), (3) combined interference screw and bone bridge (IFS/BB group), and (4) combined interference screw and suspension button (IFS/SB group). Each construct was subjected to cyclic loading (1500 cycles, 50-250 N, 1 Hz) with a servohydraulic materials testing machine to measure elongation; load-to-failure testing (displacement rate: 25 mm/s) was then performed. Load to failure, stiffness, and yield load were compared between constructs using 1-way analysis of variance.

Results

The hybrid fixation constructs (IFS/BB and IFS/SB groups) showed significantly better biomechanical properties than the isolated extracortical fixation constructs (BB and SB groups) (P < .05 for all). There were no differences between the isolated extracortical fixation constructs or between the hybrid fixation constructs in elongation or load to failure; however, stiffness of the IFS/BB group was significantly higher than that of the IFS/SB group (175.3 ± 16.6 vs 144.9 ± 20.1 N/mm, respectively; P < .05). Stiffness between the SB and BB groups was not significantly different.

Conclusion

Hybrid fixation had superior biomechanical performance compared with isolated extracortical fixation. However, tibial graft fixation using a bone bridge either as isolated extracortical fixation or combined with an interference screw for hybrid fixation showed equivalent biomechanical properties compared with suspension button-based graft fixation.

Clinical Relevance

The clinical use of a bone bridge for tibial graft fixation could reduce the cost for ACL reconstruction and lower the rate of implant-associated issues.

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

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

Does a combined screw and dowel construct improve tibial fixation during anterior cruciate ligament reconstruction?

PURPOSE

The aims of the present study were to compare the biomechanical properties of tibial fixation in hamstring-graft ACL reconstruction using interference screw and a novel combination interference screw and dowel construct.

MATERIAL AND METHODS

We compared the fixation of 30 (2- and 4-stranded gracilis and semitendinosis tendons) in 15 fresh-frozen porcine tibiae with a biocomposite resorbable interference screw (Group 1) and a screw and dowel construct (Group 2). Each graft was subjected to load-to-failure testing (50 mm/min) to determine maximum load, displacement at failure and pullout strength.

RESULTS

There were no significant differences between the biomechanical properties of the constructs. Multivariate analysis demonstrated that combination constructs (β = 140.20, p = 0.043), screw diameter (β = 185, p = 0.006) and 4-strand grafts (β = 51, p = 0.050) were associated with a significant increase in load at failure. Larger screw diameter was associated with increased construct stiffness (β = 20.15, p = 0.020).

CONCLUSION

The screw and dowel construct led to significantly increased fixation properties compared to interference screws alone in a porcine model. Increased screw diameter and utilization of 4-strand ACL grafts also led to improvement in load-to-failure of the construct. However, this is an in vitro study and additional investigations are needed to determine whether the results are reproducible in vivo.

LEVEL OF EVIDENCE

Level V; Biomechanical study.

Comparative Risk-Benefit Profiles of Individual Devices for Graft Fixation in Anterior Cruciate Ligament Reconstruction: A Systematic Review and Network Meta-analysis

PURPOSE

To compare the efficacy and safety of individual devices for femoral and/or tibial graft fixation in anterior cruciate ligament (ACL) reconstruction.

METHODS

The PubMed, Embase, Cochrane Library, and Web of Science databases were searched from inception to December 12, 2018. Randomized controlled trials comparing individual devices for ACL graft fixation were included. Bayesian network meta-analysis was performed to assess the efficacy profile using the following outcomes: Lysholm score, International Knee Documentation Committee (IKDC) category, laxity, range of motion, and Tegner score. The incidence of infection, effusion, and graft rupture for each device was reported.

RESULTS

We included 57 randomized controlled trials involving 4,304 patients aged 23.8 to 40.9 years. The female proportion ranged from 0% to 100%. The length of follow-up ranged from 6 to 144 months. Of the 13 studied femoral fixation devices, none was significantly different from the others regarding the Lysholm score, IKDC category, range of motion, and Tegner score. Bioabsorbable interference screws (standardized mean difference, 1.3; 95% credible interval, 0.0-2.5) showed higher laxity than the EndoPearl at a borderline level of statistical significance, but the difference varied substantially within multiple sensitivity analyses. Infection (2.0%) was most commonly seen with the EndoPearl, whereas the bone mulch screw had the highest incidence of effusion (5.5%) and graft rupture (5.5%). For the 9 studied tibial fixation devices, no significant difference was observed in the aforementioned efficacy measurements. Bioabsorbable interference screws with staples had the highest incidence of infection (11.1%) and effusion (15.6%), whereas graft rupture was most commonly seen with the bone plug (4.0%).

CONCLUSIONS

Graft fixation devices in ACL reconstruction share a similar efficacy profile in terms of the Lysholm score, IKDC category, range of motion, and Tegner score but not laxity. On the other hand, safety profiles seem to vary among different devices. These findings can support surgeons, alongside their experience and preference, as well as the relative cost of each device, in delivering an individualized plan for an optimal operation.

LEVEL OF EVIDENCE

Level II, meta-analysis of Level I and II studies.

Influence of operative technique on anterior cruciate ligament reconstruction in patients older than 50 years

BACKGROUND

A consequence of the steady growth in the worldwide population of elderly individuals who remain in good health and continue to engage in sports is an increase in the incidence of anterior cruciate ligament (ACL) rupture occurring after 50 years of age. ACL reconstruction was formerly reserved for young athletes but now seems to produce good outcomes in over 50s. The type of graft and graft fixation method were selected empirically until now, given the absence of investigations into potential relationships of these two parameters with the outcomes. The objective of this study was to assess associations linking the type of graft and the method of femoral graft fixation to outcomes in patients older than 50 years at ACL reconstruction.

HYPOTHESIS

The operative technique is not associated with the clinical outcomes or differential laxity.

MATERIAL AND METHODS

A multicentre retrospective cohort of 398 patients operated between 1 January 2011 and 31 December 2015 and a multicentre prospective cohort of 228 patients operated between 1 January 2016 and 30 June 2017 were conducted. Mean follow-up was 42.7 months in the retrospective cohort and 14.2 months in the prospective cohort. The primary evaluation criterion was the clinical outcome as assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the Tegner Activity Score (TAS). Differential laxity was the secondary evaluation criterion. The Wilcoxon rank sum test and Kruskal-Wallis test were used to compare groups, and p-values<0.05 were considered significant.

RESULTS

In the retrospective and prospective cohorts, hamstring tendons were used in 269 (67.6%) and 197 (86.4%) patients and extensor apparatus tendons in 124 (31.2%) and 31 (13.6%) patients. Femoral fixation in the retrospective cohort was cortical in 81 (20.4%) cases, by press-fit in 112 (28.1%) cases, and by interference screw in 205 (51.5%) cases; corresponding figures in the prospective cohort were 135 (59.2%), 17 (7.5%), and 76 (33.3%). The multivariate analysis of the retrospective data identified no significant associations of graft type or femoral fixation type with the KOOS, TAS, or differential laxity values. In the prospective cohort, hamstring grafts were associated with 0.6mm of additional laxity (p=0.007); compared to cortical fixation, press-fit fixation of patellar tendon grafts was associated with 0.3mm of additional laxity (p=0.029) and a 0.5-point lower TAS value (p=0.033), with no difference in KOOS values. None of these differences were clinically significant.

DISCUSSION

The various ACL reconstruction techniques used in patients older than 50 years produce similar outcomes. The technique can be chosen based on surgeon preference without regard for patient age.

LEVEL OF EVIDENCE

IV.

Comparison of Clinical and Radiologic Outcomes and Second-Look Arthroscopic Findings After Anterior Cruciate Ligament Reconstruction Using Fixed and Adjustable Loop Cortical Suspension Devices

PURPOSE

To compare clinical and radiological outcomes, including tunnel widening, and to evaluate graft status by second-look arthroscopy after anterior cruciate ligament (ACL) reconstruction using 2 different femoral cortical suspension devices (fixed and adjustable loop).

METHODS

Seventy-nine patients were included for this study. The patients were divided into 2 groups, 41 patients of fixed loop group (EndoButton) and 38 patients of adjustable loop group (TightRope). The Tegner activity, Lysholm knee score, Lachman test, and pivot-shift test were compared between the 2 groups. Anterior stress radiographs and femoral tunnel widening on plain radiographs were also compared. Twenty-seven patients (66%) in the EndoButton group and 21 patients (55%) in the TightRope group underwent the second-look arthroscopy.

RESULTS

At the final follow-up, the mean Tegner activity, Lysholm, and International Knee Documentation Committee scores were improved in both groups and there were no statistically significant differences (5.1 ± 1.6 and 5.5 ± 2.1, P = .312; 90.4 ± 7.8 and 91.0 ± 6.5, P = .525; and 87.4 ± 6.7 and 88.7 ± 5.3, P = .127, respectively). There were no statistical significances in the both groups in terms of Lachman test and pivot-shift tests (P = .392, .559) as well as anterior stress radiographs (mean 3.2 ± 1.4 mm and 2.9 ± 1.1 mm, P = .343). Moreover, radiologic measurements comparing femoral tunnel widening at proximal and distal half also showed no significant differences (P = .540 and .412 on anteroposterior view; P = .254 and .437 on lateral view). In the second-look arthroscopy findings for graft tear and synovial coverage, there were no significant differences (P = .784 and .897).

CONCLUSIONS

Both fixed loop and adjustable loop devices in ACL reconstruction provided good clinical and radiological outcomes. In patients with both devices, femoral tunnel widening at proximal and distal portion have no significant differences after ACL reconstruction. Moreover, second-look arthroscopy revealed no significant differences in terms of synovial coverage and rupture of the graft.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Comparison of Tunnel Enlargement and Clinical Outcome Between Bioabsorbable Interference Screws and Cortical Button-Post Fixation in Arthroscopic Double-Bundle Anterior Cruciate Ligament Reconstruction: A Prospective, Randomized Study With a Minimum Follow-Up of 2 Years

PURPOSE

To investigate the tunnel enlargement rate and clinical function by comparing double-bundle anterior cruciate ligament reconstruction (ACLR) using different fixation devices.

METHODS

Patients receiving primary arthroscopic double-bundle ACLR were screened and divided into 2 groups on the basis of the method of graft fixation: bioabsorbable interference screw (BS) group and cortical button (CB) group. Bone tunnel size was assessed digitally using magnetic resonance imaging, which was performed a minimum of 2 years postoperatively. Clinical evaluations were performed using the Knee Injury and Osteoarthritis Outcome Score, International Knee Documentation Committee score, and KT-1000 arthrometer 2 years postoperatively.

RESULTS

Sixty patients receiving primary arthroscopic double-bundle ACLR were included. Overall, the BS group showed greater tunnel enlargement than the CB group, as well as a significantly increased rate of tunnel communication (P = .029). The average anteromedial tunnel enlargement rates for the BS and CB groups were 50% and 28%, respectively. The enlargement rate of the posterolateral (PL) femoral tunnel was similar in both groups. In the PL tibial tunnel, the CB group showed a significant increase in enlargement compared with the BS group (64% vs 45%, P = .0001). Both groups showed functional improvement in the Knee Injury and Osteoarthritis Outcome Score and International Knee Documentation Committee score. No significant difference in postoperative functional outcomes was found between the 2 groups.

CONCLUSIONS

The BS group showed significantly greater tunnel enlargement in anteromedial tunnels and an increased tunnel communication rate compared with the CB group. On the other hand, the CB group showed greater tunnel enlargement in tibial PL tunnels. Tunnel communication was observed mostly on the tibial side in the BS patients. Equivalent clinical function outcomes were noted at 2 years after surgery in both groups of patients.

LEVEL OF EVIDENCE

Level II, randomized controlled clinical trial.

ACL reconstruction with hamstring tendon autograft and accelerated brace-free rehabilitation: a systematic review of clinical outcomes

OBJECTIVE

To investigate the clinical outcomes after hamstring tendon autograft ACL reconstruction (ACLR) with accelerated, brace-free rehabilitation.

DESIGN

Systematic review according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines.

DATA SOURCES

Embase, MEDLINE Ovid, Web of Science, Cochrane CENTRAL and Google scholar from 1 January 1974 to 31 January 2017.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Study designs reporting outcomes in adults after arthroscopic, primary ACLR with hamstring autograft and accelerated, brace-free rehabilitation.

RESULTS

Twenty-four studies were included in the review. The clinical outcomes after hamstring tendon autograft ACLR with accelerated brace-free rehabilitation were the following: (1) early start of open kinetic exercises at 4 weeks in a limited range of motion (ROM, 90°-45°) and progressive concentric and eccentric exercises from 12 weeks did not alter outcomes, (2) gender and age did not influence clinical outcomes, (3) anatomical reconstructions showed better results than non-anatomical reconstructions, (4) there was no difference between single-bundle and double-bundle reconstructions, (5) femoral and tibial tunnel widening occurred, (6) hamstring tendons regenerated after harvest and (7) biological knowledge did not support return to sports at 4-6 months.

CONCLUSIONS

After hamstring tendon autograft ACLR with accelerated brace-free rehabilitation, clinical outcome is similar after single-bundle and double-bundle ACLR. Early start of open kinetic exercises at 4 weeks in a limited ROM (90°-45°) and progressive concentric and eccentric exercises from 12 weeks postsurgery do not alter clinical outcome. Further research should focus on achievement of best balance between graft loading and graft healing in the various rehabilitation phases after ACLR as well as on validated, criterion-based assessments for safe return to sports.

LEVEL OF EVIDENCE

Level 2b; therapeutic outcome studies.

Cross Pin Versus Interference Screw for Femoral Graft Fixation in Hamstring Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis of Clinical Outcomes

PURPOSE

To compare the effectiveness of a cross pin and interference screw for femoral graft fixation in primary anterior cruciate ligament reconstruction (ACLR) and provide an appropriate reference for orthopaedic surgeons.

METHODS

The Medline, Cochrane Library, Web of Science, Scopus, and PubMed databases were searched in March 2016, and comparative trials using cross-pin and interference screw devices for femoral graft fixation in primary hamstring ACLR with clinical outcome measurements were included in the review. Trials with no controlled groups, hybrid fixation, no clinical outcomes, or follow-up of less than 1 year were excluded. The quality of the included studies was assessed with the Cochrane Back Review Group 12-item scale. Abstracted data were pooled with fixed or random effects depending on the detected heterogeneity. The outcome measures were the scoring system and physical examination findings, including the Lysholm score, International Knee Documentation Committee score or grade, Tegner score, negative Lachman test, negative pivot-shift test, and instrumented side-to-side anterior-posterior laxity difference.

RESULTS

All the studies reviewed were of prospective design. Within the cross-pin group, patients who underwent hamstring ACLR showed a significantly smaller instrumented side-to-side anterior-posterior laxity difference when compared with interference screw fixation (weighted mean difference, 0.38 mm [95% confidence interval, 0.08-0.67 mm]; P = .01), whereas the results of a negative Lachman test and negative pivot-shift test were comparable. Outcomes regarding the scoring system did not reach a significant difference between the 2 groups.

CONCLUSIONS

The statistically decreased instrumented side-to-side anterior-posterior laxity difference achieved by cross-pin transfixation appears to be of limited clinical significance when compared with interference screw fixation in primary hamstring ACLR. Clinically, the performance of cross-pin devices did not show a significant advantage over that of the interference screw for femoral graft fixation in hamstring ACLR.

LEVEL OF EVIDENCE

Level II.

Anterior Cruciate Ligament Soft Tissue Graft Fixation in the Elderly: Is There a Reason to Use Interference Screws? A Human Cadaver Study

PURPOSE

To analyze the ultimate failure load, yield load, stiffness, and cyclic resistance of different anterior cruciate ligament (ACL) soft tissue graft fixation techniques in osteopenic bone.

METHODS

In this study, 24 fresh-frozen human cadaveric tibiae (mean age 82.6 years; range 56-96; 6 male and 6 female donors) were used. Quantitative computed tomography was performed to match bone density. Looped porcine flexor tendon grafts were chosen as ACL graft substitutes for tibial graft fixation techniques (n = 8 each): (1) hybrid fixation with an interference screw and extracortical button fixation; (2) extracortical button fixation; and (3) interference screw fixation. In single cycle mode, constructs were loaded to failure to evaluate stiffness, yield load, and maximum load. In cyclic testing, 2,000 cycles (25-100 N) were applied followed by loading to failure. A 1-way analysis of variance was performed with significance set at P = .05.

RESULTS

Hybrid fixation resulted in significantly higher yield load (283.4 ± 86.19 N; P = .0037) and maximum load (407.9 ± 102.3 N; P = .0026) than interference screw fixation (yield load 176.4 ± 26.03, max load 231.8 ± 94.06 N) in elderly bone. Yield load after extracortical button fixation (252.9 ± 41.97 N; P = .0286) was also higher than that after interference screw fixation, but stiffness (18.98 ± 9.154 N/mm; P = .0041) was less than that after hybrid fixation (37.28 ± 13.53 N/mm). Of 8 specimens in the interference screw group, 7 did not survive 2,000 cycles and failed by graft slippage, whereas all other specimens in both other groups survived.

CONCLUSIONS

Tibial hybrid fixation of ACL soft tissue grafts provides less vertical graft movement than extracortical button fixation and higher primary failure loads than interference screw fixation in elderly bone.

CLINICAL RELEVANCE

In this elderly human joint in vitro model, tibial hybrid fixation provides biomechanical advantages over other techniques. Graft fixation with only an interference screw should be avoided in osteopenic bone.

Suspensory Versus Aperture Fixation of a Quadrupled Hamstring Tendon Autograft in Anterior Cruciate Ligament Reconstruction: A Meta-analysis

BACKGROUND

Hamstring grafts have become a popular choice for anterior cruciate ligament (ACL) reconstruction; however, the most effective means of fixation of these soft tissue grafts is unknown.

PURPOSE

To determine whether suspensory or aperture fixation of hamstring tendon autografts provides better stability and clinical outcomes in ACL reconstruction.

STUDY DESIGN

Meta-analysis.

METHODS

A literature search of studies reporting single-bundle ACL reconstructions using 4-stranded hamstring tendon autografts with aperture or suspensory fixation with a minimum 24-month follow-up was conducted. Stability and clinical outcomes were compared for aperture versus suspensory fixation. Knee stability was measured with the Lachman or pivot-shift test or KT-1000 arthrometer side-to-side difference (SSD), and outcomes were determined with the International Knee Documentation Committee (IKDC), Tegner, and Lysholm scores as well as graft failures. A random-effects model with a pooled estimate for the between-study variance was used to estimate proportions or means for each outcome and its corresponding 95% CI.

RESULTS

Forty-one studies were included, of which 20 utilized suspensory fixation techniques and 21 utilized aperture fixation techniques. A >3-mm SSD was seen more often in the aperture group than the suspensory group, which was statistically significant ( P < .0001), but there was no significant difference between groups for a >5-mm SSD ( P = .53). The aperture group demonstrated significantly more graft ruptures than did the suspensory group ( P = .03). There were no statistically significant differences in Lachman grade 0 ( P = .76), grade 1 ( P = .89), and grade 2 ( P = .55) or pivot-shift grade 0 ( P = .72), grade 1 ( P = .97), and grade 2 ( P = .28). There was no statistically significant difference in mean continuous IKDC ( P = .80), Tegner ( P = .34), or Lysholm ( P = .84) scores.

CONCLUSION

This meta-analysis demonstrated improved overall arthrometric stability and fewer graft ruptures using suspensory fixation compared with aperture fixation of a quadrupled hamstring tendon autograft in ACL reconstruction. There were no differences in IKDC, Lysholm, Lachman, and pivot-shift outcomes between suspensory and aperture fixation.

Outcomes of ACL Reconstruction With Fixed Versus Variable Loop Button Fixation

Suspensory femoral fixation of anterior cruciate ligament (ACL) grafts with fixed loop button and variable loop button devices has gained popularity for ACL reconstruction. This study examined these 2 methods of fixation to determine their effect on graft laxity and patient-reported outcome scores. A database search was performed to identify patients who had undergone ACL reconstruction with either a fixed loop or a variable loop button technique performed by the primary surgeon. Lysholm, Tegner, and 12-Item Short Form Health Survey scores were obtained, and KT-1000 knee ligament arthrometer (MEDmetric, San Diego, California) mechanical knee testing was performed. Results were compared with the uninjured knee. Of the 112 patients who were identified, 91 met the study criteria. Of these patients, 57 completed KT-1000 knee testing, 33 in the variable group and 24 in the fixed group. The average KT-1000 value for the variable group was 0.38 mm, and the average for the closed group was 0.92 mm (P=.19; 95% confidence interval, -0.28 to 1.35). Among the 19 patients in the variable group and the 13 in the closed group who completed the subjective outcomes questionnaires, no statistically significant difference was found. Clinically lax knees (KT-1000>3 mm) were found in 6.1% and 12.5% of patients in the variable group and the fixed group, respectively (P=.2). The variable group had a rerupture rate of 4.7%, whereas the fixed group had a rerupture rate of 8.7% (P=.21). The study found no statistical difference in ACL graft laxity or postoperative functional outcomes between grafts fixed with the variable loop or fixed loop button technique. [Orthopedics. 2017; 40(2):e275-e280.].

The influence of femoral tunnel length on graft rupture after anterior cruciate ligament reconstruction

Background

For ACL reconstruction, the minimum length of the femoral tunnel and the flexor tendon graft length needed within the tunnel for proper integration have not been defined. The aim of this study was to assess whether a short tunnel is a risk factor for poor prognosis and re-rupture by comparing the outcomes of patients with short femoral tunnels to those of patients with longer tunnels.

Materials and methods

A retrospective observational study of 80 patients who underwent ACL reconstruction using flexor tendons via the medial transportal or transtibial technique was performed. Patients were categorized according to the amount of graft within the tunnel: ≤1.5 versus >1.5 cm; ≤2 versus >2 cm; ≤2.5 versus >2.5 cm; and ≤1.5 versus >2.5 cm. Patients were evaluated 2 years after surgery by performing a physical examination (Lachman, pivot shift and anterior drawer tests), using a KT1000 arthrometer, calculating objective and subjective International Knee Documentation Committee scores, conducting the Lysholm score, and recording re-ruptures.

Results

Of the 80 operated patients, nine were lost to follow-up. Comparative assessment of the patients with different amounts of graft within the tunnel indicated no significant differences in the evaluated outcomes, except for positive Lachman test results, which were more frequent in patients with tunnels with ≤2 cm of graft than in those with tunnels with >2 cm of graft.

Conclusion

The amount of graft within the femoral tunnel does not appear to be a risk factor for clinical instability of the knee or re-rupture of the graft. Level of evidence: case series, level IV.

Level of evidence

Case series, level IV.

A Systematic Summary of Systematic Reviews on the Topic of the Anterior Cruciate Ligament

BACKGROUND

There has been a substantial increase in the amount of systematic reviews and meta-analyses published on the anterior cruciate ligament (ACL).

PURPOSE

To quantify the number of systematic reviews and meta-analyses published on the ACL in the past decade and to provide an overall summary of this literature.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A systematic review of all ACL-related systematic reviews and meta-analyses published between January 2004 and September 2014 was performed using PubMed, MEDLINE, and the Cochrane Database. Narrative reviews and non-English articles were excluded.

RESULTS

A total of 1031 articles were found, of which 240 met the inclusion criteria. Included articles were summarized and divided into 17 topics: anatomy, epidemiology, prevention, associated injuries, diagnosis, operative versus nonoperative management, graft choice, surgical technique, fixation methods, computer-assisted surgery, platelet-rich plasma, rehabilitation, return to play, outcomes assessment, arthritis, complications, and miscellaneous.

CONCLUSION

A summary of systematic reviews on the ACL can supply the surgeon with a single source for the most up-to-date synthesis of the literature.

Intratunnel versus extratunnel autologous hamstring double-bundle graft for anterior cruciate ligament reconstruction: a comparison of 2 femoral fixation procedures

BACKGROUND

Anatomic double-bundle anterior cruciate ligament (ACL) reconstruction provides excellent results for restoring normal kinematics to the knee. Nevertheless, strong evidence supporting an ideal method for fixation of the ACL graft is lacking.

HYPOTHESIS

Intratunnel femoral fixation of the ACL graft via a cross-pin fixation technique would provide better clinical and objective results than the extratunnel femoral fixation with cortical buttons.

STUDY DESIGN

Randomized clinical trial; Level of evidence, 2.

METHODS

Seventy patients with a unilateral ACL-deficient knee were randomly assigned to 1 of 2 femoral fixation groups. Group A (35 patients) was fixed with 2 bioabsorbable Rigidfix pins, 1 cross-pin per bundle, while group B (35 patients) was secured with 1 EndoButton cortical button per bundle. All femoral tunnels were created via an anteromedial portal, and a bioabsorbable Biointrafix interference screw was used for tibial fixation for both groups. The evaluation of the patients was performed by history details, clinical examination findings, measurement of the joint laxity by KT-1000 arthrometer, and use of validated patient outcome questionnaires. Statistical analysis was carried out with Fisher exact and Mann-Whitney U tests, with P<.05 considered the cutoff level of significance.

RESULTS

At a mean follow-up of 30 months, 34 and 32 patients of group A and B, respectively, were available for evaluation. There were no statistically significant differences between the treatment groups regarding the subjective and objective outcomes, except for KT-1000 arthrometer values. The median KT-1000 value of patients in the cross-pin fixation group was 1.30 mm, while the median value in the cortical button fixation group was 1.95 mm (P<.001). Four patients with ACL grafts that were fixed with cortical buttons demonstrated failure of stability via the instrumented knee laxity testing, while patients from the other group had no failures.

CONCLUSION

Intratunnel femoral fixation of the double-bundle ACL graft from the cross-pin fixation technique provided better instrumented knee laxity results than did the extratunnel femoral fixation with cortical buttons. Future larger studies comparing these 2 techniques should be conducted to ensure the availability of stronger evidence supporting the findings of this study.

Anterior cruciate ligament reconstruction: a new cortical suspension device for femoral fixation with transtibial and transportal techniques

Background

In the field of anterior cruciate ligament (ACL) reconstruction, there is still no consensus regarding the proper fixation method and position of the tunnels. The primary objective of this paper was to describe a new fixation device, the Endo Tunnel Device (ETD®), for both techniques (transtibial and transportal), as well as the associated difficulties and the intraoperative and postoperative intercurrences. The secondary objective was to describe a preliminary clinical evaluation (6 months of follow-up) comparing these techniques.

Methods

This was a prospective, randomized study involving 80 patients with ACL reconstructions using the ETD® for femoral fixation. Forty patients underwent the transtibial technique, and 40 patients underwent the transportal technique. Patients were evaluated by radiography, physical examination, the KT1000 arthrometer, and Lysholm and the International Knee Documentation Committee (IKDC) scores.

Results

There were more intraoperative intercurrences in the transportal group (soft tissue device fixation, short femoral tunnel, and short graft inside the tunnel). The IKDC scores were significantly better in the transportal group.

Conclusions

The ETD® was demonstrated to be a safe femoral fixation device in this trial; its use in both the transtibial and transportal techniques is technically simple and is associated with few intra- or postoperative complications.

Clinical and functional outcomes after anterior cruciate ligament reconstruction using cortical button fixation versus transfemoral suspensory fixation: a systematic review of randomized controlled trials

PURPOSE

To compare clinical and functional outcomes after anterior cruciate ligament (ACL) reconstruction using cortical button versus transfemoral suspensory fixation.

METHODS

This systematic review was conducted following the Cochrane handbook guidelines and PROSPERO registration. Only Level I and II randomized controlled trials comparing cortical button and transfemoral suspensory fixation in hamstring ACL reconstruction were included. A literature search was performed using electronic databases. The methodologic quality of included studies was assessed using The Cochrane Collaboration's risk-of-bias tool. All outcomes reported by each study were evaluated. Primary outcome measures were postoperative International Knee Documentation Committee (IKDC) and Lysholm knee scores. Statistical analysis was performed using RevMan software (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen). Dichotomous data were reported as risk ratio and 95% confidence intervals. Heterogeneity was assessed using I(2).

RESULTS

Five studies involving 317 patients were included. The mean follow-up period was 21.7 ± 7.0 months (range, 12 to 38 months). The mean age of participants was 26.7 ± 1.89 years (range, 16 to 48 years). The Lysholm score, Tegner activity score, and IKDC score were compiled. Clinical assessment was performed by Lachman testing, assessment of side-to-side differences on KT-1000 (MEDmetric, San Diego, CA) testing, and measurements of thigh atrophy, as well as imaging (radiography and computed tomography) to assess for femoral tunnel widening. Pooled statistical analysis was possible only for postoperative IKDC and Lysholm scores. No significant differences were found between the cortical button and transfemoral fixation groups. Included studies did not report differences in clinical outcomes between the 2 groups. Radiographic results suggest increased femoral tunnel widening in the cortical button group. However, tunnel widening was not found to affect clinical results.

CONCLUSIONS

The present evidence suggests that there are no short- to medium-term differences in knee-specific outcome measures between patients treated with cortical button femoral graft fixation and those treated with suspensory transfemoral fixation when undergoing ACL reconstruction. In addition, radiologic evidence of tunnel widening does not seem to affect short- to medium-term clinical outcomes.

LEVEL OF EVIDENCE

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