Controversies in soft-tissue anterior cruciate ligament reconstruction: grafts, bundles, tunnels, fixation, and harvest

Double-bundle versus single-bundle anterior cruciate ligament reconstruction in preventing the progression of osteoarthritis: A protocol for systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The knee has a high incidence of osteoarthritis (OA) following the anterior cruciate ligament (ACL) injury, which was reduced by ACL reconstruction including double-bundle (DB) techniques and single-bundle (SB) techniques. However, the effectiveness of preventing the progression of OA after the ACL reconstruction using DB and SB techniques is controversial.

METHODS

This meta-analysis was performed following the preferred reporting items for systematic reviews and meta-analyses guidelines. The databases, including PubMed, Embase, and Cochrane Library, were searched. Randomized controlled trials comparing DB with SB ACL reconstruction and reporting clinical outcomes of radiological OA were included. Quality of the included studies was assessed using the Cochrane Collaboration's risk of bias tool. The outcome was analyzed using the risk ratio (RR) and its corresponding 95% confidence interval (CI).

RESULTS

Ten Randomized controlled trials studies were included in this meta-analysis (accounting 1062 knees: 475 SB and 587 DB). The rate of radiological OA after the ACL reconstruction was 39% in SB group and 34% in DB group. The results of meta-analysis showed no difference in the occurrence of radiological OA between DB group and in SB group (RR, 1.05; 95% CI, 0.85-1.30, P = .63), including subgroup of radiological scores of OA (subgroup of Minimal OA: RR, 0.95; 95% CI, 0.61-1.48; P = .82; subgroup of Notable OA: RR, 1.16; 95% CI, 0.75-1.78; P = .51), subgroup of follow-up time in 5 years and more than 5 years (RR, 0.98; 95% CI, 0.80-1.20; P = .85), and subgroup of autograft graft for ACL (RR, 0.97; 95% CI, 0.79-1.19; P = .77). However, the DB group had less incidences of knee OA than the SB group in subgroup of less than 5 years (RR, 1.48; 95% CI, 1.13-1.92; P = .004) and subgroup of allograft type (RR, 1.42; 95% CI, 1.06-1.91; P = .02).

CONCLUSION

Overall, this meta-analysis showed that the DB technique was no more effective in preventing the progression of OA than the SB technique in ACL reconstruction at midterm follow-up.

Comparison of clinical outcomes of using the nonirradiated and irradiated allograft for anterior cruciate ligament (ACL) reconstruction: A systematic review update and meta-analysis

BACKGROUND

This study was a systematic review comparing the clinical outcomes of using the nonirradiated and irradiated allograft for anterior cruciate ligament (ACL) reconstruction.

METHODS

A comprehensive literature search was conducted using multiple databases, including Medline, Embase, and Cochrane. All databases were searched from the earliest records through August 2019 using the following Boolean operators: irradiated AND nonirradiated AND ACL AND allograft. All prospective and retrospective controlled trials were retrieved that directly compared physical examination and knee function scores and patient-rated outcomes between the nonirradiated and irradiated allograft for ACL reconstruction.

RESULTS

Three prospective and 2 retrospective articles were identified by the search, and the findings suggested that the nonirradiated allografts were superior to the irradiated allografts based on improved knee joint functional scores and decreased failure rate, even though there was no significantly difference with respect to overall IKDC, range of motion, vertical jump test, and one-leg hop test.

CONCLUSIONS

Irradiated allograft should be limited to be used in ACL surgery and further research into new alternative sterilization techniques are needed to avoiding the disease transmission without interference with the biomechanical properties of the grafts.

ACL autograft reconstruction revisions with tendon allografts: Possibilities and outcomes. A one-year follow-up of 39 patients

BACKGROUND

The number of anterior cruciate ligament (ACL) reconstructions is steadily rising in France. Re-tear rates of up to 25% have been reported and graft selection remains a notable challenge. Allografts, although rarely used in France, can be a viable option. The primary objective of this study was to demonstrate the benefits of ACL revision with allografts, by determining subjective scores (IKDC score and KOOS), measuring laxity, and evaluating the rate of return to sports.

HYPOTHESIS

Tendon allografts are reliable and can be used in France for ACL reconstruction revision.

MATERIAL AND METHODS

We conducted a retrospective study including 39 patients managed in two centres between 2004 and 2016 and followed up for at least a year. Patients were eligible if they had undergone tendon allograft reconstruction for ACL revision with or without rupture of a peripheral plane. We excluded underage patients and patients with a history of ligament injury in the contralateral knee. Mean age was 32 years. The allografts were extensor mechanisms, anterior or posterior tibial tendons, fascia lata tendons, hamstring tendons, and a short fibular tendon. They were obtained from French and Belgian tissue banks. They were used for the reconstruction of 39 ACLs and 11 collateral ligaments. The IKDC score and KOOS were determined in all patients. Laximetry was performed in 31 patients by an independent examiner.

RESULTS

Mean follow-up was 3.5 years. Arthroscopic release was required in one patient, and 2 patients experienced re-tears. No deep surgical site infections were recorded. The subjective IKDC score and the KOOS improved significantly, from 53.6 to 80.7 and from 60.4 to 83.2, respectively. Mean postoperative differential laxity was 1.4mm (KT 1000) and 1.6mm (GNRB®). Of the 3 patients who were professional athletes, 2 had returned to sports at the same level one year later, and among the recreational athletes, 54% had resumed their previous sporting activities.

CONCLUSION

In the setting of complex ligament reconstruction revision, tendon allografts are reliable and can be used in France.

LEVEL OF EVIDENCE

IV; retrospective cohort study.

Freehand Anatomic Transtibial Single-Bundle Anterior Cruciate Ligament Reconstruction

Creation of the femoral tunnel for single-bundle anterior cruciate ligament (ACL) reconstruction has a high rate of nonanatomic placement with the transtibial (TT) technique but yields better restoration with the anteromedial portal technique and close restoration of the anatomic femoral footprint with the outside-in technique. Modifications of the traditional (TT) technique have been described to restore the native femoral ACL footprint and to simulate double-bundle reconstruction. Modified TT techniques try to capture the anatomic femoral footprint through an anatomic tibial tunnel. In the technique described in this article, the anatomic femoral footprint is drilled first by the use of a 2.5-mm Kirschner wire through the parapatellar anteromedial portal, making an angle 30° to the sagittal plane and 20° to the horizontal plane. The wire is drilled while the knee is hyperflexed and then withdrawn from outside until its distal end reaches the intercondylar notch. The wire is then advanced in an antegrade manner while the knee is flexed 90° until it reaches the center of the marked tibial footprint. The angle of knee flexion may be slightly increased or decreased around 90° with or without slight internal rotation to capture the anatomic tibial footprint. The procedure is completed as a TT single-bundle ACL reconstruction.

Comparing post-operative pain between single bundle and double bundle anterior cruciate ligament reconstruction: a retrospective study

Background

In anterior cruciate ligament (ACL) reconstruction, the clinical outcome and level of post-operative pain are important factors. To date there have been no studies evaluating differences in post-operative pain between single bundle and double bundle ACL reconstruction with a hamstring graft.

Hypothesis/purpose

We hypothesized that post-operative pain in single bundle ACL reconstruction would be less than in double bundle ACL reconstruction. This study was to compare post-operative pain between patients undergoing single bundle versus double bundle ACL reconstruction.

Study design

Cohort study.

Methods

This was a retrospective study comparing post-operative pain scores between single bundle and double bundle ACL reconstruction. Each patient was given our standard regimen of oral diclofenac (25 mg/tab) three times per day and paracetamol (500 mg/tab) six times per day for 1 day post-operatively. If the patient complained of moderate to severe pain (pain numeric rating scale (PNRS) > 3), 3 mg of morphine was injected intravenously every 3 h for 24 h and 1 mg of morphine as a rescue medication every 1 h for 24 h. PNRS and morphine consumption were recorded at 4-h intervals for 24 h.

Results

209 patients were included in this study of whom 102 and 107 patients received single bundle and double bundle ACL reconstruction, respectively. The average post-operative pain scores of the single bundle group were lower at all time points. Linear mixed effect regression analyses showed that the single bungle group had lower post-operative pain than the double bundle group after adjusting for confounders (beta = − 0.45; 95% CI = − 0.838, − 0.062) but there was no statistically significant difference between numbers of bundle ACL reconstruction with regard to morphine consumption.

Conclusion

Single bundle ACL reconstruction had significantly lower post-operative pain scores than double bundle ACL reconstruction.

Clinical relevance

Double bundle ACL reconstruction results in higher post-operative pain, which may slow the start of rehabilitation and reduce patient satisfaction. In middle-aged adult patients with low-demand activities, we suggest performing a single bundle ACL reconstruction.

Evolution in ACL Autograft Harvesting Techniques: Transition to Minimally Invasive Autograft Harvesting

Surgical techniques for anterior cruciate ligament (ACL) reconstruction continue to evolve. Harvesting techniques for commonly used ACL autografts such as bone patellar tendon bone, hamstring, and quadriceps tendon have similarly continued to progress. Traditional larger incisions for graft harvesting that were described in the 1980s have given way to smaller or more minimally invasive techniques. Advantages of these techniques are primarily anatomy based and include the following: decreased nerve complaints such as hypoesthesia or dysesthesia, improved cosmesis, decreased surgical site pain or morbidity, and, in the case of hamstring harvesting, easier tendon identification. The current literature supports reproducible minimally invasive or modified graft harvesting techniques for bone patellar tendon bone, hamstring, and quadriceps tendon autografts. Specialized instrumentation is available to simplify the harvesting process. Each of these techniques is described in detail outlining surgical steps, technical considerations, and precautions. Knowledge and review of these techniques provides the surgeon with greater flexibility and options when choosing and harvesting autograft tissue for ACL reconstruction.

Insufficient evidence to support peroneus longus tendon over other autografts for primary anterior cruciate ligament reconstruction: a systematic review

IMPORTANCE

Graft choice for anterior cruciate ligament reconstruction (ACLR) remains a subject of interest among orthopaedic surgeons because no ideal graft has yet been found. Peroneus longus tendon (PLT) has emerged as an alternative autograft for reconstruction in kneeling populations and in simultaneous anterior cruciate ligament (ACL) and medial collateral ligament (MCL) injuries.

OBJECTIVE

To evaluate the current evidence on the outcome of primary ACLR with PLT autograft in adults and donor ankle morbidity, in addition to determining the average PLT graft dimensions from published studies.

EVIDENCE REVIEW

Two independent reviewers searched PubMed, CENTRAL, EMBASE, Scopus and Virtual Health Library databases using the terms "anterior cruciate ligament," "peroneus longus" and "fibularis longus" alone and in combination with Boolean operators AND/OR. Studies evaluating clinical and stability outcomes, graft-donor ankle morbidity and graft dimensions of PLT in ACLR were included. Methodological quality was assessed using the Modified Coleman Methodology Score (mCMS). A narrative analysis is presented using frequency-weighted means wherever feasible. Publication bias was assessed using the ROBIS tool.

FINDINGS

Twelve articles with intermediate-level methodological quality were included. Eight studies assessing the clinical and stability outcomes of reconstruction with PLT showed satisfactory outcomes, similar to those of hamstring tendons (HT). No studies assessed anterior knee pain as an outcome. Six studies evaluated the graft-donor ankle morbidity using general functional foot and ankle scores and non-validated tools, showing favourable outcomes. Nine studies assessed PLT graft diameter, revealing grafts consistently larger than 7 mm among the different preparation techniques, which is comparable with reports of HT grafts.

CONCLUSIONS AND RELEVANCE

The clinical and stability outcomes of ACLR with different PLT autograft preparation techniques are comparable with those of HT during short-term follow-up; however, there is insufficient evidence to support its use in the populations that motivated its implementation. Thus, stronger evidence obtained with the use of validated tools reporting negligible donor-graft ankle morbidity after PLT harvesting is required prior to recommending its routine use, despite the consistency of its dimensions.

LEVEL OF EVIDENCE

Level III.

The role of anterolateral augmentation in primary ACL reconstruction

The anterolateral soft tissue envelope of the knee has long been recognised as a key stabilising structure. Once the mainstay of operative management of anterior cruciate ligament (ACL) rupture, interest in the area fell away with the advent of intraarticular arthroscopic reconstruction. Renewed interest in these structures together with cadaveric data evidencing the potential for restoration of near normal knee biomechanics following ACL and anterolateral soft tissue reconstruction has driven current concepts and development of operative techniques. Options for current anterolateral augmentation techniques in primary ACL reconstruction plus patient selection considerations are reviewed, together with an outlook at future research key to development of this area.

Early or delayed anterior cruciate ligament reconstruction: Is one superior? A systematic review and meta-analysis

Background

Anterior cruciate ligament (ACL) reconstruction is a rapidly developing orthopaedic field and an area of notable clinical equipoise. The optimal timing of surgery in an acute (< 3 weeks) or delayed (≥ 3 weeks) time frame remains unresolved with a 2010 meta-analysis concluding no difference between these two groups across multiple outcomes. In an era of evidence-based medicine, surgeons are still basing their decisions on when to operate on little more than anecdotal evidence and personal preference. Clear guidance is required to determine whether the timing of surgery can optimise outcomes in this largely young and active patient cohort.

Methods

A systematic literature search was performed in January 2018 of Embase, Medline and OpenGrey in accordance with (PRISMA) guidelines. A total of 658 articles were retrieved, with 6 suitable for inclusion, covering 576 ACL reconstructions. Four meta-analyses were performed assessing subjective measures of Tegner activity scale and Lysholm score, and objective measures of arthroscopically identified meniscal and chondral injury. Additional relevant outcome measures underwent narrative review. Study bias was assessed and reported using the Downs and Black checklist.

Results

A statistically significant difference of 0.39 points was found on the Tegner activity scale in favour of early surgery within 3 weeks (RR 0.39, CI 0.10, 0.67, p = 0.008). No statistically difference was found between groups for the patient-reported Lysholm score (RR − 0.18, CI − 2.40, 2.05, p = 0.17). There was no statistically significant difference between groups for intra-operative findings of meniscal lesions (RR 0.84, CI 0.66, 1.08, p = 0.17). A trend towards significance was observed for the incidence of chondral lesions in the early surgery group (RR 0.56, CI 0.31, 1.02, p = 0.06). All the studies were rated either fair or good on the Downs and Black checklist with no study excluded due to bias.

Conclusions

Although there was a statistically significant result for the Tegner activity scale in favour of early surgery, the magnitude of the effect is unlikely to translate into any clinically meaningful difference. At present, there remains no clear evidence to determine superiority of acute/early or delayed reconstruction of a ruptured anterior cruciate ligament. Further research through methodologically robust randomised controlled trials or through the UK National Ligament Registry  may help to provide clearer guidance.

A Clinical and Magnetic Resonance Imaging Assessment of Anterior Cruciate Ligament Reconstruction with Different Fixation Techniques Using Gracilis and Semitendinosus Autograft

Background:

Hamstring tendons are widely used in anterior cruciate ligament reconstruction. Improvements in fixation materials have increased the success of the reconstruction procedures using this type of graft. The main advantage of the hamstring tendon autograft is the lower donor site morbidity associated with its harvesting. On the other hand, tunnel widening is reported more frequently with the use of hamstring tendon autograft compared to patellar or quadriceps tendons. The objective of the present study was to evaluate three different fixation techniques at a minimum of 2 years after Anterior Cruciate Ligament (ACL) reconstruction using gracilis and semitendinosus autograft.

Methods:

Between February 2012 and March 2016, 112 ACL reconstructions using double looped semitendinosus and gracilis graft were performed. Patients were divided into 3 groups in a randomized fashion. 98 patients were followed up for 2 years. In the first group (43 patients), suspensory fixation using Retrobutton (Arthrex, Inc, Naples, Florida) was used. In the second group (30 patients), transcondylar graft fixation Bio-Transfix (Arthrex, Naples, Florida) was performed, and in the third group (25 patients), aperture fixation using AperFix (Cayenne Medical, Scottdale, Arizona, Biomet) was performed. Clinical evaluation was performed using the International Knee Documentation Committee (IKDC) form, Lysholm knee and Tegner activity level scores, as well as arthometer measurements. Tunnel enlargement and graft integrity were evaluated using Magnetic Resonance Imaging (MRI) at 6, 12 and 24 months.

Results:

Ten patients were completely lost to follow up, and four had undergone a revision ACL reconstruction before the two-year follow up period, leaving 98 patients for analysis. No statistically significant differences between the three groups were noted other than that the first group tended to have more tunnel enlargement than the other two groups, especially at the femoral tunnel (p=.026), but not at the tibial tunnel (p>0.408). Our results showed that almost 90% of the patients in the three groups had functionally normal or near normal IKDC, Lysholm and Tegner scores.

Conclusion:

The three different techniques yielded equal results as regards improved patient performance. The functional results as well as knee stability tests were not related with tunnel enlargement, at least in the short term.

Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction with Hamstring Tendon Autograft through Single Femoral Tunnel and Single Branched Tibial Tunnel

Conventional single-bundle anterior cruciate ligament (ACL) reconstruction cannot improve the rotational stability of the knee. Traditional double-bundle ACL reconstruction requires is demanding, complex, time- and implant consuming, and associated with a high incidence of complications. Double-bundle ACL reconstruction using a free quadriceps tendon autograft through 3 independent tunnels provides some advantage, but the antegrade graft passage, tibial tunnel confluence, and graft site morbidity represent disadvantages. This Technical Note describes a modification of double-bundle ACL reconstruction using the hamstring tendon autograft through a single branched tibial tunnel and a single femoral tunnel using 2 interference screws (Arthrex, Naples, FL). The gracilis tendon autograft is passed through tibial tunnel stem to the posterolateral tibial tunnel branch to the posterolateral position in the femoral tunnel. The semitendinosus tendon autograft is passed through the tibial tunnel stem to the anteromedial tibial tunnel branch to the anteromedial position in the femoral tunnel. Both grafts are fixed by 2 interference screws: 1 at the femoral tunnel and 1 at the tibial tunnel stem with the knee at 20° flexion.

Autogenous Hamstring-Bone Graft Preparation for Anterior Cruciate Ligament Reconstruction

Despite the popularity of anterior cruciate ligament (ACL) reconstruction procedures, the ideal graft for reconstruction remains a matter of controversy. The ideal graft for ACL reconstruction should have histologic and biomechanical characteristics similar to those of the native ACL; should be quickly and fully incorporated within the bony tunnels; should maintain its viscoelastic properties for a long time; should have minimal donor-site morbidity; should be of sufficient length and diameter; should have minimal adverse effects on the extensor mechanism; should have no risk of rejection or disease transmission; and should be cost-effective and readily available. Synthetic grafts are not widely accepted because of their dangerous complications. The main sources of grafts for ACL reconstruction are allografts and autografts. Each type of graft has its own relative advantages and disadvantages. Allografts are not available in every country, besides being expensive, and there are many concerns regarding disease transmission. Autografts, particularly bone-patellar tendon-bone (BPTB), and hamstring tendon grafts have been the standard for ACL reconstruction. The main advantage of autogenous BPTB grafts is the direct bone-to-bone healing in the tunnel, whereas the main disadvantages of such grafts are related to donor-site morbidity, anterior knee pain, and extensor mechanism dysfunction. The popularity of autogenous hamstring tendon grafts for ACL reconstruction is increasing, but there are still concerns regarding the slow soft tissue-to-bone healing, with delayed healing and incorporation of the graft. We describe a technique for ACL reconstruction with autogenous hamstring-bone graft, aiming to produce a type of graft that combines the main advantages of BPTB and hamstring grafts, with avoidance of the main disadvantages of these 2 most commonly used graft types in ACL reconstruction.

Anterior cruciate ligament reconstruction: principles of treatment

Anterior cruciate ligament (ACL) reconstruction is one of the most common procedures in sports medicine. Several areas of controversy exist in ACL tear management which have engaged surgeons and researchers in debates towards identifying an ideal approach for these patients.

This instructional review discusses the principles of ACL reconstruction in an attempt to provide guidelines and initiate a critical thinking approach on the most common areas of controversy regarding ACL reconstruction.

Using high-level evidence from the literature, as presented in randomised controlled trials, systematic reviews, and meta-analyses, operative versus conservative treatment, timing of surgery, and rehabilitation are discussed. Also, the advantages and disadvantages of the most common types of autografts, such as patellar tendon and hamstrings as well as allografts are presented.

Key considerations for the anatomical, histological, biomechanical and clinical data (‘IDEAL’) graft positioning are reviewed.

Cite this article: Paschos NK, Howell SM. Anterior cruciate ligament reconstruction: principles of treatment. EFORT Open Rev 2016;398-408. DOI: 10.1302/2058-5241.1.160032.

Arthroscopic anatomic double-bundle ACL reconstruction using irradiated versus non-irradiated hamstring tendon allograft

PURPOSE

To analyse the clinical outcome of anatomic double-bundle anterior cruciate ligament (ACL) reconstruction with irradiated versus non-irradiated hamstring allograft.

METHODS

One hundred and twelve patients who met the inclusion and exclusion criteria of the study were prospectively randomized consecutively into irradiated hamstring tendon allograft (Ir-Allo) group and non-irradiated allograft (Non-ir-Allo) group. All surgeries were done by the same senior surgeon with double-bundle reconstruction technique. Before surgery and at follow-up points, patients were evaluated by the same observer according to clinical evaluations.

RESULTS

Eighty-three patients (Non-ir-Allo, 44; Ir-Allo, 39) fulfilled complete follow-up and got full clinical evaluations. The mean follow-up period was 5.7 years (ranging from 5.0 to 6.5 years). At the final follow-up, significant differences were found when comparing the results of the two groups according to Lachman test, ADT, pivot shift test and KT-2000 arthrometer testing (P < 0.05). According to KT-2000, 86.4 % of patients in the Non-ir-Auto group and 35.9 % in the Ir-Allo group had a side-to-side difference of <3 mm. According to the overall IKDC, functional, subjective evaluations and activity level testing, no significant differences were found between the two groups. Regarding the arthritic progression, there was significant difference between the two groups (Ir-Allo group: 30.8 %, Non-ir-Allo group: 11.4 %, P < 0.05).

CONCLUSION

A significant increase in anterior and rotational laxity in patients of the Ir-Allo group was found according to evaluations. No significant differences in activity level and functional scores were found between the two groups. We do not advocate the irradiated hamstring tendon allograft for ACL reconstruction.

LEVEL OF EVIDENCE

I.

A biomechanical analysis of tibial ACL reconstruction with graft length mismatch

INTRODUCTION

The incidence of graft length mismatch (GLM) during anterior cruciate ligament (ACL) reconstruction is reported to be up to 13%, with a rate of 20% when using bone-patellar tendon-bone (BPTB) allografts. Multiple techniques have been described to accommodate for the longer BPTB graft. As no study has compared the biomechanical properties of these methods (with cyclic loading), we evaluated the strength of four different surgical techniques used to accommodate for GLM during ACL reconstruction.

METHODS

A total of 32 fresh-frozen bovine tibiae and patellar tendons were divided into four groups based on the method of tibial graft fixation: (1) sutures tied over a post, (2) bone staples, (3) screws and washers, and (4) soft-tissue conversion with interference screw. Biomechanical testing was performed comparing the tensile properties of graft fixation techniques under cyclic loading. Ability to withstand 1500 cycles of load, the maximum tensile strength at load-to-failure, and the mode-of-failure were evaluated.

RESULTS

Only group 4 had all grafts intact after 1500 loading cycles, while the other groups had one graft failure at 338 (group 1), 240 (group 2), and 309 (group 3) cycles. The highest mean load-to-failure was observed in group 3 at 762 ± 173 N, which was found to be significantly higher than the other groups. The mean loads to failure in groups 1-4 were 453 ± 86 N, 485 ± 246 N, 762 ± 173 N, and 458 ± 128 N.

CONCLUSION

While there are multiple viable techniques for fixation of a BPTB graft in the case of GLM, this study demonstrated that direct screw fixation offers the strongest construct.

A Validation Study of a Novel 3-Dimensional MRI Modeling Technique to Identify the Anatomic Insertions of the Anterior Cruciate Ligament

Background:

Anatomic single bundle anterior cruciate ligament (ACL) reconstruction is the current gold standard in ACL reconstructive surgery. However, placement of femoral and tibial tunnels at the anatomic center of the ACL insertion sites can be difficult intraoperatively. We developed a “virtual arthroscopy” program that allows users to identify ACL insertions on preoperative knee magnetic resonance images (MRIs) and generates a 3-dimensional (3D) bone model that matches the arthroscopic view to help guide intraoperative tunnel placement.

Purpose:

To test the validity of the ACL insertion sites identified using our 3D modeling program and to determine the accuracy of arthroscopic ACL reconstruction guided by our “virtual arthroscopic” model.

Study Design:

Descriptive laboratory study.

Methods:

Sixteen cadaveric knees were prescanned using routine MRI sequences. A trained, blinded observer then identified the center of the ACL insertions using our program. Eight knees were dissected, and the centers of the ACL footprints were marked with a screw. In the remaining 8 knees, arthroscopic ACL tunnels were drilled into the center of the ACL footprints based on landmarks identified using our virtual arthroscopic model. Postprocedural MRI was performed on all 16 knees. The 3D distance between pre- and postoperative 3D centers of the ACL were calculated by 2 trained, blinded observers and a musculoskeletal radiologist.

Results:

With 2 outliers removed, the postoperative femoral and tibial tunnel placements in the open specimens differed by 2.5 ± 0.9 mm and 2.9 ± 0.7 mm from preoperative centers identified on MRI. Postoperative femoral and tibial tunnel centers in the arthroscopic specimens differed by 3.2 ± 0.9 mm and 2.9 ± 0.7 mm, respectively.

Conclusion:

Our results show that MRI-based 3D localization of the ACL and our virtual arthroscopic modeling program is feasible and does not show a statistically significant difference to an open arthrotomy approach. However, additional refinements will be required to improve the accuracy and consistency of our model to make this an effective tool for surgeons performing anatomic single-bundle ACL reconstructions.

Clinical Relevance:

Arthroscopic anatomic single-bundle ACL reconstruction is the current gold standard for ACL reconstruction; however, the center of the ACL footprint can be difficult to identify arthroscopically. Our novel modeling can improve the identification of this important landmark intraoperatively and decrease the risk of graft malposition and subsequent graft failure.

Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction With a Hamstring Tendon Autograft and Fresh-Frozen Allograft: A Prospective, Randomized, and Controlled Study

PURPOSE

To compare the clinical outcome of anatomic double-bundle (DB) anterior cruciate ligament (ACL) reconstruction with a hamstring tendon autograft versus fresh-frozen allograft.

METHODS

Between January 2010 and December 2011, in a prospective randomized study, we included 157 patients who were planned to receive anatomic DB ACL reconstruction with a hamstring tendon autograft or fresh-frozen allograft. All surgeries were performed by the same senior surgeon with the DB reconstruction technique. The fixation of femoral side grafts was by means of an EndoButton, and the tibial side grafts were fixed with a bioabsorble interference screw augmented with a staple. The same rehabilitation protocol was applied to all the patients. Patients were evaluated preoperatively and at the follow-up points. Evaluations included detailed history, physical examination, radiograph, functional knee ligament testing, KT-2000 arthrometer testing, Harner's vertical jump and Daniel's one-leg hop tests, Lysholm score, Tegner score, the International Knee Documentation Committee (IKDC) standard evaluation form, and Cincinnati knee score.

RESULTS

One hundred and twenty-one patients (Auto, 62; Allo, 59) fulfilled complete follow-up and got full clinical evaluations. The mean follow-up was 4.6 years (4.0 to 5.5 years) for both groups. No significant differences were found between the 2 groups according to the evaluations aforementioned except that patients in the Allo group had shorter operation time compared with the Auto group (P = .001). Fifty-three (85.5%) patients in the Auto group and 50 (84.7%) patients in the Allo group had a side-to-side difference of less than 3 mm. Four (6.5%) patients in the Auto group and 4 (6.8%) patients in the Allo group had a side-to-side difference of more than 5 mm. Fifty-nine (95.8%) patients in the Auto group and 55 (93.2%) patients in the Allo group were normal or nearly normal according to the overall IKDC. According to the subjective IKDC, the average scores were 90 and 89 points, respectively, for the Auto and Allo groups. The mean Lysholm and Tegner scores were 90 points and 7.9 points for the Auto group, respectively, and 89 points and 7.8 points for the Allo group, respectively. For the Cincinnati knee score, the average scores were 91 and 90 points, respectively, for the Auto and Allo groups. A total of 11.3% (7 of 62) of patients in the Auto group and 11.9% (7 of 59) of patients in the Allo group had an arthritic progression. There was no statistical difference between the 2 groups at the final follow-up.

CONCLUSIONS

With the anatomic DB ACL reconstruction technique, comparable objective and subjective clinical results can be achieved with the use of a fresh-frozen hamstring tendon allograft compared with an autograft.

LEVEL OF EVIDENCE

Level II, prospective randomized clinical trial.

Arthroscopically blind anatomical anterior cruciate ligament reconstruction using only navigation guidance: a cadaveric study

BACKGROUND

To develop a preoperative planning and navigation system for anatomic anterior cruciate ligament (ACL) reconstruction and to evaluate the accuracy and the efficacy of anatomical ACL reconstruction using only navigation guidance.

METHODS

A three-dimensional (3D) preoperative planning and navigation system was developed from open source libraries. Twenty knees from 10 fresh-frozen human cadavers underwent navigation-only guided double-bundle ACL reconstruction using the transportal technique. A computed tomography (CT) scan was performed after ACL reconstruction to create a 3D surface model of the distal femur. We evaluated the tunnel position by Bernard's quadrant method, the tunnel orientation by measuring the tunnel angle in three projected planes, and the incidence of posterior cortical damage. Then, we compared preoperative planning with the postoperative results.

RESULTS

The difference in tunnel position between preoperative planning and the postoperative results was a mean of 2.50±1.75mm (range, 0.77 to 5.85mm) in the anteromedial (AM) tunnel and a mean of 3.53±2.20mm (range, 0.39 to 7.92mm) in the posterolateral (PL) tunnel. The difference in tunnel orientation was a mean of 6.74±6.70° (range, 0.35 to 25.6°) in the AM tunnel and a mean of 5.73±3.51° (range, 1.58 to 15.04°) in the PL tunnel. No statically significant difference was observed. Posterior cortical damage developed in seven cases (35%).

CONCLUSIONS

Our navigation-only guided ACL reconstruction produced consistent femoral tunnel position and orientation results. The accuracy and consistency of femoral tunneling were improved by using the preoperative planning and navigation system.

Irradiated Hamstring Tendon Allograft Versus Autograft for Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction: Midterm Clinical Outcomes

BACKGROUND

Most studies on grafts for anterior cruciate ligament (ACL) reconstruction (ACLR) have been of autografts or nonirradiated allografts with a single-bundle (SB) technique. Outcome reports evaluating anatomic double-bundle (DB) ACLR with a hamstring tendon autograft versus irradiated allograft are rare.

PURPOSE

To compare the clinical outcomes of arthroscopic anatomic DB ACLR with a hamstring tendon autograft versus irradiated allograft.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 2.

METHODS

Between 2008 and 2009, a total of 107 patients undergoing arthroscopic DB ACLR were prospectively randomized consecutively into 1 of 2 groups (autograft [Auto] group and irradiated allograft [Ir-Allo] group). All the surgical procedures were performed by the same senior surgeon using the DB reconstruction technique. All irradiated hamstring tendon allografts were sterilized with 2.5 Mrad of irradiation before distribution and were obtained from a single certified tissue bank. Graft fixation on the femoral side was by an Endobutton, and on the tibial side by a bioabsorbable interference screw augmented with a staple. The same rehabilitation protocol was applied to all patients. Before surgery and at a mean of 6.9 years of follow-up, patients were evaluated by the same observer according to objective and subjective clinical evaluations including detailed history, physical examination, radiography, functional knee ligament testing, KT-2000 arthrometer testing, Harner vertical jump and Daniel 1-legged hop tests, Lysholm score, Tegner score, International Knee Documentation Committee (IKDC) standard evaluation form, and Cincinnati knee score.

RESULTS

A total of 83 patients (Auto: n = 40 [mean age, 29.2 ± 6.9 years]; Ir-Allo: n = 43 [mean age, 28.6 ± 7.2 years]) fulfilled follow-up and clinical evaluations. No significant differences were found between the 2 groups according to the overall IKDC functional and subjective evaluations as well as testing of activity levels. Significant between-group differences were found when comparing the results at final follow-up according to the Lachman test, anterior drawer test, pivot-shift test, and KT-2000 arthrometer measurements (P < .001). Most importantly, 87.5% of patients in the Auto group and 34.9% in the Ir-Allo group had a side-to-side difference <3 mm. The rate of laxity (side-to-side difference >5 mm) with an irradiated allograft (30.2%) was higher than that with an autograft (7.5%) (P < .001). The failure rate in the Ir-Allo group (30.2%) was higher than that in the Auto group (7.5%) (P < .001). Anterior and rotational stability decreased significantly in the Ir-Allo group; patients in the Ir-Allo group also had a shorter operation time. There were 10.0% (4/40) of patients in the Auto group and 32.6% (19/43) of patients in the Ir-Allo group who had arthritic progression (P < .05).

CONCLUSION

There were no significant differences in postoperative activity levels and functional outcomes between the Auto and Ir-Allo groups. However, a significant increase in anterior and rotational laxity in the Ir-Allo group was found according to evaluations. We do not advocate an irradiated hamstring tendon allograft for DB ACLR.

TRIAL REGISTRATION

Clinical Trial Register System of The Affiliated Hospital of Qingdao University (qdfy-ky2008-12).

Are porcine flexor digitorum profundus tendons suitable graft substitutes for human hamstring tendons in biomechanical in vitro-studies?

INTRODUCTION

Although a plenty of studies exist assessing the strength of ligamentous fixation techniques using porcine flexor digitorum profundus tendons as graft substitutes for human hamstring tendons, there is no biomechanical study comparing these two tendons. To interpret the results obtained with porcine flexor digitorum profundus tendons, knowledge of their biomechanical properties is essential. The purpose of this study was to compare the biomechanical properties of human hamstring tendons and porcine flexor digitorum profundus tendons.

MATERIALS AND METHODS

A total of six human hamstring tendons and six porcine flexor digitorum profundus tendons were analysed in this study. Quadruple-bundle human hamstring tendons and double-bundle porcine flexor digitorum profundus tendons with a diameter of 9 mm were used. Specimens were placed into a tensile loading fixation of a servohydraulic testing machine. Biomechanical analysis included pretensioning of the constructs at 50 N for 10 min following cyclic loading of 1500 cycles between 50 and 200 N at 0.5 Hz for measurement of elongation. Subsequently, ultimate failure load and failure mode analysis were performed with a ramp speed of 20 mm/min.

RESULTS

Human hamstring tendons showed significantly higher maximum load to failure values compared to porcine flexor digitorum profundus tendons (1597 ± 179.6 N vs. 1109 ± 101.9 N; p = 0.035). Human hamstring tendons yielded significantly lower initial elongation during preload, but not during cyclical loading.

CONCLUSIONS

When porcine flexor digitorum profundus tendons are used as graft substitutes for human hamstring tendons in biomechanical studies, maximum load to failure is underestimated while elongation is comparable to that of human hamstring tendons. Transferring results of biomechanical studies into clinical practice, the lower maximum load to failure of porcine flexor digitorum profundus tendons needs to be taken into consideration.

In vitro comparison between cortical and cortico-cancellous femoral suspension devices for anterior cruciate ligament reconstruction: implications for mobilization

PURPOSE

To analyse the capability of cortical and cortical-cancellous suspension devices to provide a strong fixation in order to follow an aggressive early mobilization protocol.

METHODS

Anterior cruciate ligament (ACL) reconstruction was performed in vitro on 40 porcine femurs employing a high-strength braided cord as a graft. Four femoral suspension devices were analysed: the cortical suspension devices Endobutton and XO Button and the cortical-cancellous suspension devices Biosteon Cross-pin and Cross-pin ACL. Two kinds of biomechanical testing were carried out: static and post-fatigue failure strength tests. Stiffness, failure load, elongation at failure load, elongation after 20 cycles and elongation after 1,000 cycles were assessed. The bones were cut after testing to analyse the failure pattern.

RESULTS

All of the devices exceed 50 % of total elongation in the first 20 cycles of fatigue. In the static failure tests, there were significant differences (p < 0.05) in elongation to failure between the cortical-cancellous suspension devices Biosteon Cross-pin and Cross-pin ACL and the cortical suspension device Endobutton. No significant differences were found in the failure tests after 1,000 cycles of loading. The failure mode of the cortical devices comprised breakage of the cortical bone, accompanied by introduction of the device into the tunnel. The failure mode of the cortical-cancellous devices was pin breakage accompanied by tunnel enlargement.

CONCLUSION

The first cycles of mobilization are critical for elongation. This mobilization process does not significantly diminish the mechanical characteristics of the reconstructions. All the fixations support an intensive early mobilization protocol, with loads of over 500 N.

Comparison of allograft versus autograft anterior cruciate ligament reconstruction graft survival in an active adolescent cohort

BACKGROUND

Graft selection for anterior cruciate ligament (ACL) reconstructive surgery is a controversial topic. Few studies have compared graft outcomes in adolescents.

PURPOSE

To identify factors related to ACL graft failure in an adolescent cohort.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

After institutional review board approval was obtained, adolescent subjects (age range, 11-18 years) who underwent primary ACL reconstruction surgery at a large tertiary pediatric hospital between July 2005 and July 2009 were identified through a query of International Classification of Diseases, 9th Revision, diagnostic and Current Procedural Terminology codes. Subject data were obtained by means of a retrospective chart review, phone survey, and the administration of functional knee outcome instruments. A multivariate Cox proportional hazards regression analysis was used to analyze factors related to graft survival.

RESULTS

The average ages at surgery in the allograft (n = 38) and autograft (n = 35) groups were 15.29 ± 2.24 and 15.60 ± 1.57 years, respectively. There were 11 graft failures (28.95%) in the allograft group compared with 4 graft failures (11.43%) in the autograft group. In the multivariate model, graft type (P = .0352) and postoperative knee laxity according to the Lachman test (P = .0217) were the only variables significantly related to graft survival. The hazard of graft failure was 4.4 (95% CI, 1.23-18.89) times greater in the allograft group compared with the autograft group. The hazard of graft failure was 5.28 times (95% CI, 1.1-12.72; P = .0217) greater for a subject who demonstrated increased postoperative knee laxity relative to the contralateral knee. The risk for autograft failure tended to remain constant 24 to 48 months after initial surgery, whereas the risk for allograft failure continued to increase during postoperative months 24 to 48. There were no differences (P > .05) between the allograft and autograft groups with respect to International Knee Documentation Committee score, Lysholm score, and the rate of return to previous activity level.

CONCLUSION

Graft type and postoperative knee laxity were identified as significant predictors of graft survival. On the basis of this large retrospective cohort, we recommend the use of autogenous grafts in children and adolescents undergoing primary, transphyseal ACL reconstruction. Patients who demonstrate increased translation during a postoperative Lachman test should be carefully followed because of concerns for subsequent graft failure.

Anterior talofibular ligament ruptures, part 2: biomechanical comparison of anterior talofibular ligament reconstruction using semitendinosus allografts with the intact ligament

BACKGROUND

Anatomic reconstructions of the lateral ankle ligaments with grafts have been proposed for patients with generalized ligamentous laxity, long-standing instability with attenuated native tissues, varus hindfoot misalignment, or failed prior lateral ligament surgery and for very large patients or elite athletes because of increased demands.

HYPOTHESIS

Anatomic reconstruction of the anterior talofibular ligament (ATFL) using a semitendinosus allograft fixed with biocomposite interference fit screws would have similar biomechanical properties to the intact ATFL at time zero in a cadaveric model.

STUDY DESIGN

Controlled laboratory study.

METHODS

Allograft reconstruction of the ATFL was performed in 6 fresh-frozen cadaveric ankles. The specimens were loaded to failure to determine the strength and stiffness of the reconstruction and compared with data from 6 cadaveric specimens with intact ATFLs.

RESULTS

The mean ultimate load to failure of the allograft reconstruction (170.7 ± 54.8 N) was not significantly different from that of the intact ATFL (154.0 ± 63.7 N). The mean stiffness of the allograft reconstruction (23.1 ± 9.3 N/mm) was also not significantly different from that of the intact ATFL (14.5 ± 4.4 N/mm).

CONCLUSION

Anatomic reconstruction of the ATFL with allografts demonstrated similar strength and stiffness to the native ligament at time zero in a fresh-frozen cadaveric model.

CLINICAL RELEVANCE

This technique of anatomic reconstruction of the ATFL with allografts has biomechanical validation for use in clinical situations where a Broström repair of the lateral ankle ligaments is unlikely to be successful or has previously failed.

Meta-analysis comparing bioabsorbable versus metal interference screw for adverse and clinical outcomes in anterior cruciate ligament reconstruction

PURPOSE

To compare bioabsorbable screw (BS) against metal screw (MS) primarily on adverse effects and secondarily on clinical outcomes after single-bundle primary anterior cruciate ligament reconstruction.

METHODS

Electronic searches were performed using search strategies meeting the mentioned purposes. Retrieved articles were selected for randomised controlled trials (RCTs) reporting at least 1-year follow-up. Potential studies were selected under inclusion and exclusion criteria. Risk of biases and data extraction was completed by two review authors. Discrepancies were resolved through discussion. Mean difference and risk ratio with 95 % confidence interval (CI) were used for continuous and binary outcomes, respectively. Heterogeneity was assessed using I (2). Pooled treatment effects with 95 % CI were estimated using the fixed- or random-effect model where appropriate.

RESULTS

Eleven RCTs with 878 randomly allocated patients were included, and 711 patients (81 %) with eligible follow-up time up to 8 years were analysed. Comparing with the MS group, BS group using medial hamstring graft showed evidence of larger tunnel widening on the femoral side measured from radiographs or magnetic resonance imaging, though data could not be pooled because diverse measurement methods had been used. Significantly higher rates of effusion and screw breakage, and fewer cases of complete tunnel healing were reported in the BS group. Nevertheless, functional and clinical results were not deteriorated by the presence of these adverse effects for both short- and longer-term follow-ups.

CONCLUSION

This is the first systematic review focusing on adverse effects of the BS, such as larger tunnel widening and higher rates of other complications. With these effects, routine use of the BS should be balanced with the advantages claimed. Cost-effectiveness is another issue, and well-designed RCTs are needed to better validate the implication.

Current trends in anterior cruciate ligament reconstruction

The advances in the knowledge of anatomy, surgical techniques, and fixation devices have led to the improvement of anterior cruciate ligament (ACL) reconstruction over the past 10 years. Nowadays, double bundle and anatomical single bundle ACL reconstruction that more closely restores the normal anatomy of the ACL are becoming popular. Although there is still no definite conclusion whether double bundle ACL reconstruction provides better clinical results than single bundle reconstruction, the trend has shifted to anatomic reconstruction regardless of single bundle or double bundle techniques. We could not find any significant differences in the clinical outcomes and stability after ACL reconstruction according to the type of graft or fixation device. Therefore, surgeons should select an ideal ACL reconstruction according to the patient's condition and surgeon's experience.

Outcomes for primary anterior cruciate reconstruction with the quadriceps autograft: a systematic review

PURPOSE

To determine the suitability of the quadriceps autograft in primary anterior cruciate ligament (ACL) reconstruction.

METHODS

A systematic review was undertaken to identify all clinical studies reporting on the use of the quadriceps tendon autograft in ACL reconstructions. Studies that reported on clinical and functional outcomes, morbidity and complications were selected.

RESULTS

Seventeen articles met our inclusion criteria with a total of 1,580 reconstructions studied. This included four comparative studies which compared the quadriceps tendon to either hamstring or patella tendon autografts. The quadriceps tendon autograft had clinical (Lachman, Pivot-shift testing) and functional outcomes (Lysholm and IKDC scores) similar to those reported for the patella tendon and hamstring grafts in the literature. Comparative studies also reported no significant difference between the grafts for any outcome measure.

CONCLUSIONS

The quadriceps tendon autograft is a promising alternative for primary ACL reconstructions with good outcomes and minimal donor site morbidity. Further studies are required, however, to determine whether the quadriceps graft is as good as or better than other autografts.

LEVEL OF EVIDENCE

IV.

Revision anterior cruciate ligament reconstruction: an update

With the rising number of anterior cruciate ligament (ACL) reconstructions performed, revision ACL reconstruction is increasingly common nowadays. A broad variety of primary and revision ACL reconstruction techniques have been described in the literature. Recurrent instability after primary ACL surgery is often due to non-anatomical ACL graft reconstruction and altered biomechanics. Anatomical reconstruction must be the primary goal of this challenging revision procedure. Recently, revision ACL reconstruction has been described using double bundle hamstring graft. Successful revision ACL reconstruction requires an exact understanding of the causes of failure and technical or diagnostic errors. The purpose of this article is to review the causes of failure, preoperative evaluation, graft selection and types of fixation, tunnel placement, various types of surgical techniques and clinical outcome of revision ACL reconstruction.

Anterior cruciate ligament injuries: anatomy, physiology, biomechanics, and management

OBJECTIVE

Anterior cruciate ligament (ACL) injuries are the most common ligament injury in the United States. These injuries can be career ending for athletes and severely disabling for all individuals. Our objectives are to review the epidemiology of these injuries, as well as ACL biomechanics, anatomy, and nonsurgical and surgical management so that generalists as well as sports medicine physicians, orthopedists, and others will have a better understanding of this serious injury as well as choices in its management.

DATA SOURCES

PubMed was used to identify relevant articles. These articles were then used to identify other sources.

MAIN RESULTS

Anterior cruciate ligament injuries occur more commonly in women than in men due to a variety of anatomical factors. The ACL consists of 2 major bundles, the posterolateral and the anteromedial bundles. Forces transmitted through these bundles vary with knee-joint position. Some patients with ACL injuries may not be candidates for surgery because of serious comorbid medical conditions. However, without surgical repair, the knee generally remains unstable and prone to further injury. There are a variety of surgical decisions that can influence outcomes. Single-bundle versus double-bundle repair, whether to leave the ruptured ACL remnant in the knee, the selection of the graft tissue, graft placement, and whether to use the transtibial, far anteromedial portal, or tibial tunnel-independent technique are choices that must be made.

CONCLUSIONS

With a sound knowledge of the anatomy and kinetics of the knee, newer improved surgical techniques have been developed that can restore proper knee function and have allowed many athletes to resume their careers. These new techniques have also limited the disability in nonathletes.

Allografts in Anterior Cruciate Ligament Reconstruction

Usual allograft sources for anterior cruciate ligament (ACL) reconstruction are patellar ligament, Achilles tendon, tibialis anterior, and posterior. The advantages of the use of allograft include reduced donor-site morbidity, shorter operative time, smaller incisions, and no size restrictions. The disadvantages include increased cost, slower graft embodiment, and the risk of viral or bacterial infection, which may occur either by transmission from an infected donor or by contamination by the healthcare provider. Careful donor selection, aseptic graft procurement and processing, and tissue sterilization, by irradiation or proprietary chemical processing, are the three major steps of the graft preparation procedure. Successful allograft implantation depends on sterility, reduction of antigenicity, and preservation of the biomechanical properties of the graft. To date, reports on the clinical and functional outcomes of allograft compared to autograft ACL reconstruction are controversial. Overall, graft choice depends on surgeon and patient preference, since no graft can perfectly match the properties of the native ACL.

A prospective randomized comparison of irradiated and non-irradiated hamstring tendon allograft for ACL reconstruction

PURPOSE

To analyze the outcome of arthroscopic anterior cruciate ligament reconstruction with irradiated versus non-irradiated hamstring tendon allograft.

METHODS

All hamstring tendon allografts were obtained from a single certified tissue bank, and the irradiated allografts were sterilized with 2.5 Mrad of irradiation prior to distribution. A total of 78 patients who met the inclusion and exclusion criteria of the study were prospectively randomized consecutively into two groups (Non-ir-Allo vs. Ir-Allo). All the operations were done by the same senior surgeon. Before surgery and at follow-up, patients were evaluated by the same observer according to clinical evaluations including the Lachman test, ADT, pivot shift test, varus/valgus stress test, the instrumented KT-2000 arthrometer testing, vertical jump test, one-leg hop test, ROM of knee, Cincinnati knee score, IKDC Subjective Knee Form, Tegner activity score, modified Lysholm knee scoring scale, and the standard knee ligament evaluation form of the IKDC.

RESULTS

Of these patients, 69 (Non-ir-Allo 38, Ir-Allo 31) were available for full evaluation. When compared the Ir-Allo group with Non-ir-Allo group at the final follow-up by Lachman test, ADT, pivot shift test, and KT-2000 arthrometer testing, statistically significant differences were found (P < 0.05). Most importantly, 84% of patients in the Non-ir-Auto group and just only 32% in the Ir-Allo group had a side-to-side difference of less than 3 mm according to KT-2000. The anterior and rotational stability decreased significantly in the Ir-Allo group. According to the overall IKDC, functional, subjective evaluations, and activity level testing, no statistically significant differences were found between the two groups (n.s.). As to the osteoarthritis (OA) rate, for the Non-ir-Allo group, there was no significant difference (n.s.) in development of OA between the operated knee and contralateral knee at the final follow-up. While for the Ir-Allo group, significant difference (P < 0.05) was found in development of OA between the operated knee and contralateral knee. There was statistical difference (P < 0.05) between the Non-ir-Allo and Ir-Allo groups when comparing the development of OA of the operated knees at the final follow-up.

CONCLUSION

There was a significant difference in knee stability between the two groups (in favor of Non-ir-Allo), but no differences in functional scores should be pointed out clearly.

LEVEL OF EVIDENCE

I.

The incidence of and clinical approach to positive allograft cultures in anterior cruciate ligament reconstruction

OBJECTIVE

To define the incidence of positive allograft cultures in anterior cruciate ligament (ACL) reconstruction and to determine a clinical approach to a positive test.

DESIGN

Retrospective chart review, cohort series.

SETTING

Urban academic hospital.

PATIENTS

All patients who underwent anterior cruciate ligament reconstruction using allograft between January 2003 and December 2008. One hundred fifteen patients met the inclusion criteria.

INTERVENTIONS

Culture of allograft before surgical implantation.

MAIN OUTCOME MEASURES

Positive allograft culture.

RESULTS

Positive allograft cultures were obtained in 3 of 115 grafts (2.6%). Two cultures grew coagulase-negative Staphylococcus and 1 grew Escherichia coli, both from the broth only.

CONCLUSIONS

Positive cultures in ACL allografts have a reported incidence of 5.7% to 13.25%. Our current series shows an incidence of 2.6%. No patients who had a culture-positive allograft developed a clinical infection postoperatively. Routine preimplantation culture of soft tissue allografts cannot be recommended given the low incidence of positive culture and lack of correlation with clinical infection. In the presence of a positive preimplantation allograft culture without signs of clinical infection, our series and the 4 other published series in the literature demonstrate that antibiotic treatment is not indicated. In contrast, signs and symptoms of septic arthritis should be aggressively treated with irrigation, debridement, and intravenous antibiotics.

Anterior cruciate ligament reconstruction using remnant preservation and a femoral tensioning technique: clinical and magnetic resonance imaging results

PURPOSE

The purpose of this study was to investigate the clinical and magnetic resonance imaging (MRI) results of anterior cruciate ligament (ACL) reconstruction with autogenous hamstring tendon by use of remnant preservation and a femoral tensioning technique.

METHODS

A total of 53 patients who had ACL reconstruction by use of remnant ACL stump preservation and a femoral tensioning technique were evaluated. Clinical evaluation at a minimum of 2 years after surgery included range of motion, Lachman test, pivot-shift test, KT-2000 arthrometer testing (MEDmetric, San Diego, CA), and clinical scores. Plain radiographs were evaluated for tunnel enlargement. MRI was obtained for evaluation of graft continuity, cyclops-like mass lesion, and positioning of the tibial tunnel. Second-look arthroscopy was performed in 33 patients.

RESULTS

The clinical scores improved postoperatively. There were statistically significant differences between preoperative and postoperative Lachman tests, pivot-shift tests, and KT-2000 arthrometer measurements. Postoperative MRI was available in 48 patients, and it showed intact graft in 45 patients, 2 partial tears, and 1 complete loss of graft. There were cyclops-like mass lesions in 12 patients, but none showed an extension limitation or pain at extension. The position of the tibial tunnel on the sagittal and coronal view was similar to the position of the normal ACL tibial insertion. The measured tibial tunnel widening on the radiographs at final follow-up was 2.2 ± 1.5 mm.

CONCLUSIONS

Reconstruction of the ACL by use of preservation and femoral tensioning of the remnant tissue showed good clinical results without increased concerns regarding incorrect tunnel formation. Postoperative MRI showed an increased incidence of cyclops-like mass lesions, but no clinical significance was observed.

LEVEL OF EVIDENCE

Level IV, case series.

Arthroscopic reconstruction of the anterior cruciate ligament with hamstring tendon autograft and fresh-frozen allograft: a prospective, randomized controlled study

BACKGROUND

Most studies of allograft versus autograft for anterior cruciate ligament reconstruction have been of bone-patellar tendon-bone; outcome reports evaluating anterior cruciate ligament reconstruction with hamstring tendon autograft versus allograft are rare.

PURPOSE

This study was undertaken to compare the clinical outcome of arthroscopic anterior cruciate ligament reconstruction with hamstring tendon autograft versus allograft.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 2.

METHODS

Between 2000 and 2004, 208 patients who met the inclusion and exclusion criteria of the study were prospectively randomized into autograft (n = 104) or allograft (n = 104) groups. All hamstring tendon allografts were fresh-frozen and obtained from a single certified tissue bank. All the operations were done by the same surgeon with the same surgical technique. Femoral and tibial fixation was by means of an EndoButton and a bioabsorbable interference screw augmented with a staple, respectively. Patients were evaluated preoperatively and postoperatively. Evaluations included detailed history, physical examination, functional knee ligament testing, KT-2000 arthrometer testing, Harner vertical jump and Daniel 1-legged hop tests, Lysholm score, Tegner score, the International Knee Documentation Committee (IKDC) standard evaluation form, Cincinnati knee score, and radiographs.

RESULTS

Of these patients, 186 (autograft, n = 91; allograft, n = 95) were available for full evaluation. Demographic data were comparable between groups. The mean follow-up was 7.8 years for both groups. There were no statistically significant differences according to the evaluations of the outcome aforementioned between the 2 groups except that patients in the allograft group had a shorter operation time than the autograft group. Seven patients (7.7%) in the autograft group and 8 (8.4%) in the allograft group had a side-to-side difference >5 mm. Eighty-five patients (93.4%) in the autograft group and 86 (90.5%) in the allograft group were normal or nearly normal according to the overall IKDC. According to the subjective IKDC, the average scores were 89 and 90 points, respectively, for the autograft and allograft groups. The mean Lysholm and Tegner scores were 89 points and 7.7 points, respectively, for the autograft group and 90 points and 7.6 points, respectively, for the allograft group. For the Cincinnati knee score, the average scores were 90 and 91 points, respectively, for the autograft and allograft groups.

CONCLUSION

Both groups of patients achieved almost the same satisfactory outcome at an average of 7.8 years of follow-up. Fresh-frozen hamstring tendon allograft is a reasonable alternative choice to autograft for anterior cruciate ligament reconstruction.

Biomechanical analysis of chlorhexidine power irrigation to disinfect contaminated anterior cruciate ligament grafts

BACKGROUND

Accidental graft contamination is a likely complication to occur in an orthopaedic sports medicine surgeon's career. There are no clinical outcome studies to direct management, and a recent survey showed that preferred management varied. Three liters of 2% chlorhexidine power irrigation has been shown to be an efficient and effective disinfection protocol; however, the biomechanical sequelae of this disinfection protocol to the graft are unknown.

PURPOSE

The purpose of this study was to determine if 3 L of 2% chlorhexidine power irrigation used to disinfect contaminated anterior cruciate ligament (ACL) grafts significantly weakens the graft at time zero.

STUDY DESIGN

Controlled laboratory study.

METHODS

Eight fresh bovine superficial digital flexor tendons underwent disinfection protocol with 3 L of 2% chlorhexidine power irrigation. Contralateral tendons served as the control. Tendons were preconditioned and loaded to failure.

RESULTS

The average ultimate failure load for the control tendons and disinfected tendons was 4081 ± 654.4 N and 4146 ± 723.2 N, respectively. The average ultimate failure stress for the control tendons and disinfected tendons was 97.10 ± 12.03 MPa and 95.18 ± 11.79 MPa, respectively. The average stiffness for the control tendons and disinfected tendons was 546.20 ± 28.16 N/mm and 539.2 ± 25.93 N/mm, respectively. The P values for ultimate failure load, ultimate failure stress, and stiffness showed no statistically significant difference between the chlorhexidine and control tendons.

CONCLUSION

Disinfecting tendons with 3 L of 2% chlorhexidine power irrigation does not adversely weaken the tendon's tensile mechanical properties.

CLINICAL RELEVANCE

Three liters of 2% chlorhexidine power irrigation can effectively disinfect a contaminated ACL graft without weakening the graft.

Double-bundle and double-tunnel ACL reconstruction with looped proximal tibial fixation

Double-bundle anterior cruciate ligament (ACL) reconstruction can be demanding and time consuming and requires twice as many implants, increasing both costs and possible complications. In this article, we present a new approach to double bundle ACL reconstruction: a biological fixation of the tibial side by means of a double tunnel and a U-shape passage of an anterior tibialis allograft, fixed into a double tunnel on the femoral condyle with 2 interference bioabsorbable screws. The technique is designed to combine 2 known procedures for the regular knee surgeon: the mono-tunnel technique and the medial-portal approach.

What effect does anterior cruciate ligament tibial guide orientation have on tibial tunnel length?

PURPOSE

To evaluate the effects of alteration in tibial guide pin insertion angle and external starting point on tibial tunnel length for anterior cruciate ligament (ACL) reconstruction.

METHODS

Ten cadaveric tibial specimens were used. One pin was placed at each of variable insertion angles (55°, 50°, and 45°) of the tibial targeting device aimed at the center of the tibial ACL footprint. These 3 pins started externally along the anterior border of the superficial medial collateral ligament. A fourth pin at 50° was placed at a different external tibial starting point 1.5 cm anterior to the anterior border of the superficial medial collateral ligament. The intraosseous length of each pin was measured. Statistic analyses were performed with the Kruskal-Wallis test, with significance set at P < .05.

RESULTS

The mean length for the 55° tibial tunnel was 50.3 mm (range, 42 to 56 mm); for the 50° tunnel, it was 48.9 mm (range, 44 to 55 mm); for the 50° anterior tunnel, it was 47.6 mm (range, 39 to 55 mm); and for the 45° tunnel, it was 47.3 mm (range, 41 to 52 mm). Changing the angle of the tibial guide did not significantly affect the length of the tibial tunnel (P = .18). Changing the external tibial starting point did not affect the length of the tibial tunnel (P = .39).

CONCLUSIONS

Changing the tibial guide angle between 45°, 50°, and 55° does not appreciably change tibial tunnel length. Moving the starting point anterior 1.5 cm toward the tibial tubercle also has no effect on the tibial tunnel length. The lack of significant changes in tunnel length with these interventions may reflect the associated changes that occur in proximal tibial morphometry with change in external tibial starting position.

CLINICAL RELEVANCE

Changing tibial tunnel length in ACL reconstruction likely requires more distalization of the external tibial starting point than is achieved simply by altering the tibial aiming guide angle by 10° or less.

Arthroscopically pertinent landmarks for tunnel positioning in single-bundle and double-bundle anterior cruciate ligament reconstructions

BACKGROUND

Quantification of the overall anterior cruciate ligament (ACL) and anteromedial (AM) and posterolateral (PL) bundle centers in respect to arthroscopically pertinent bony and soft tissue landmarks has not been thoroughly assessed.

HYPOTHESIS

A standardized anatomical measurement method can quantitate the locations of the ACL and AM and PL bundle centers in reference to each other and anatomical landmarks.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Quantification of the ACL and its bundle attachments was performed on 11 cadaveric knees using a radio frequency-tracking device.

RESULTS

The tibial ACL attachment center was 7.5 mm medial to the anterior horn of the lateral meniscus, 13.0 mm anterior to the retro-eminence ridge, and 10.5 mm posterior to the ACL ridge. The femoral ACL attachment center was 1.7 mm proximal to the bifurcate ridge and 6.1 mm posterior to the lateral intercondylar ridge. The tibial AM attachment center was 8.3 mm medial to the anteromedial aspect of the lateral meniscus anterior horn, 17.8 mm anterior to the retro-eminence ridge, and 5.6 mm posterior to the ACL ridge. The femoral AM attachment center was 4.8 mm proximal to the bifurcate ridge and 7.1 mm posterior to the lateral intercondylar ridge. The tibial PL bundle attachment center was 6.6 mm medial to the posteromedial aspect of the lateral meniscus anterior horn, 10.8 mm anteromedial to the root attachment of the lateral meniscus posterior horn, and 8.4 mm anterior to the retro-eminence ridge. The femoral PL bundle attachment center was 5.2 mm distal to the bifurcate ridge and 3.6 mm posterior to the lateral intercondylar ridge.

CONCLUSION

The authors developed a comprehensive compilation of measurements of arthroscopically pertinent bony and soft tissue landmarks that quantitate the ACL and its individual bundle attachment centers on the tibia and femur.

CLINICAL RELEVANCE

These clinically relevant arthroscopic landmarks may enhance single- and double-bundle ACL reconstructions through improved tunnel placement.

ACL injury and surgical treatment options

The anterior cruciate ligament (ACL) has been the focus of a substantial amount of research. Thousands of studies have evaluated the structure and function of the intact ACL, as well as the best reconstruction techniques. Despite the amount of literature, many controversies remain regarding the ACL and its surgical reconstruction. This article reviews the anatomy and function of the native ACL, the nature of injury, and aspects of ACL reconstruction, including surgical approach, tunnel positioning, graft choice, and graft fixation.

Anterior cruciate ligament reconstruction using achilles tendon allograft: an assessment of outcome for patients age 30 years and older

Achilles allografts have become popular for anterior cruciate ligament (ACL) reconstructions in older patients. Primary ACL reconstructions using Achilles tendon allografts in patients age 30 years and older are successful in restoring the knee to "normal" or "near normal." During a three-year period, the two senior authors performed 65 primary ACL reconstructions using Achilles tendon allografts in patients aged 30 years and older. Our exclusion criteria were periarticular fracture, ipsilateral/contralateral knee ligament injury, and previous or concomitant osteotomy or cartilage restoration procedure. Each patient was evaluated via physical examination, functional and arthrometric testing, and radiographic and subjective outcome. Knees were considered normal, near normal, or abnormal based on the International Knee Documentation Committee (IKDC) system. Forty-three patients were examined at an average of 33 months (minimum, 24 months) postoperatively. At the time of ACL reconstruction, 35% had normal articular cartilage in all three compartments and 70% had meniscal tears. No re-ruptures occurred. While 24% had mean maximal translation differences less than or equal to 3 mm, none had side-to-side differences greater than 5 mm. Postoperative IKDC, Activities of Daily Living, and Activity Rating Scale scores averaged 88, 94, and 7.7, respectively. Despite the overall favorable outcomes, 29% had worsened radiographic grades at follow-up. Using an Achilles allograft for ACL reconstruction in patients older than 30 years, we restored over 90% of knees to normal or near normal while limiting postoperative complications. Poor subjective results may be related less to instability and more to pain, which may result from progressive arthritis.

The anterior cruciate ligament provides resistance to externally applied anterior tibial force but not to internal rotational torque during simulated weight-bearing flexion

PURPOSE

We investigated knee kinematics during simulated weight-bearing flexion and determined the effect of 3 different parameters of external tibial loading on the kinematics of the anterior cruciate ligament (ACL)-intact and ACL-deficient knee.

METHODS

Ten human knee specimens were mounted on a dynamic knee simulator, and weight-bearing muscle-loaded knee flexions were simulated while a robotic/universal force sensor system was used to provide external tibial loads during the motion. Three different loading conditions were simulated: partial body weight only, an additional 50 N of anterior tibial force (ATD), or an additional 5 Nm of internal rotational tibial torque (IRT). After arthroscopic transection of the ACL, these 3 trials were repeated. The kinematics were measured with an ultrasonic measuring system for 3-dimensional motion analysis, and different loading and knee conditions were examined.

RESULTS

When the ACL was intact, ATD and IRT barely changed the anterior tibial translation. However, in the absence of the ACL, ATD significantly increased the anterior tibial translation by 5 mm whereas IRT did not. The application of IRT increased the internal tibial rotation of ACL-intact knees, but there was no difference in the internal rotation before and after transection of the ACL. Regardless of ACL status, the difference in the anterior tibial translation and the internal tibial rotation across different external tibial loadings was greater at lower flexion angles and gradually diminished with increasing flexion angles.

CONCLUSIONS

We established an experimental protocol, incorporating a dynamic knee simulator and a robotic/universal force sensor system, to successfully measure the kinematics of the knee joint while applying external forces in weight-bearing flexion. Our findings suggest that, in muscle-loaded knee flexion, the ACL provides substantial resistance to externally applied ATD but not to IRT.

CLINICAL RELEVANCE

Information from this study allows us to better understand the function of the ACL and, hence, treatment of injuries to this important stabilizing ligament.

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.

Hamstring donor-site block: evaluation of pain control after anterior cruciate ligament reconstruction

PURPOSE

The purpose of this study was to evaluate the effectiveness of using a hamstring donor-site block in controlling postoperative pain levels after anterior cruciate ligament (ACL) reconstruction with autogenous hamstring graft.

METHODS

Over a 5-month period, 27 patients underwent ACL reconstruction with hamstring autograft. All patients received a preoperative femoral nerve block. Intraoperatively, these patients were randomly assigned to groups with and without a hamstring donor-site block. The block group received a 20-mL injection of 0.25% bupivacaine into the hamstring donor site through an arthroscopic shaver sleeve. Both groups received standard postoperative pain medications as needed. Postoperative pain scores were taken by use of a visual analog scale (VAS) and recorded immediately on arrival to the recovery room, at 1 hour after arrival, and at 2 hours after arrival.

RESULTS

There were 15 patients in the hamstring donor-site block group and 12 patients in the standard treatment group. For the block group, mean VAS scores were 3.20 +/- 2.54 on arrival, 2.80 +/- 1.61 at 1 hour, and 2.87 +/- 1.41 at 2 hours. For the standard treatment group, mean VAS scores were 5.50 +/- 1.62 on arrival, 6.08 +/- 1.56 at 1 hour, and 5.33 +/- 2.02 at 2 hours. The hamstring block group had statistically significantly lower mean VAS scores on arrival (P = .0118), at 1 hour (P = .0001), and at 2 hours (P = .0010). There were no complications in either group.

CONCLUSIONS

Injection of the hamstring donor site with local anesthetic through an arthroscopic shaver sleeve showed a statistically significant improvement in postoperative pain levels in patients undergoing autogenous hamstring ACL reconstruction.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Intraoperative complications using the Bio-Transfix femoral fixation implant in anterior cruciate ligament reconstruction

The use of biodegradable Transfix femoral fixation technique is a safe and well-accepted method when performing anterior cruciate ligament reconstruction. We report on three cases of deformation and back out of the Bio-Transfix implant over the lateral, distal femoral cortex, with failure of the passing wire when advancing the graft into the femoral tunnel in one of these patients. Two of the patients presented with symptoms of iliotibial band friction syndrome, while the third patient was asymptomatic. The graft had clinically integrated demonstrating AP and rotational stability. The symptoms relieved after removal of the failed Bio-Transfix implants in the symptomatic patients. The aetiology of the implant failure and the alternative methods to avoid such complications are discussed.

A systematic review of anterior cruciate ligament reconstruction with autograft compared with allograft

BACKGROUND

Anterior cruciate ligament reconstruction can be performed with use of either autograft or allograft tissue. It is currently unclear if the outcomes of these two methods differ significantly. This systematic review and meta-analysis investigated whether the short-term clinical outcomes of anterior cruciate reconstruction with allograft were significantly different from those with autograft.

METHODS

A computerized search of the electronic databases MEDLINE and EMBASE was conducted. Only therapeutic studies with a prospective or retrospective comparative design were considered for inclusion in the present investigation. Two reviewers independently assessed the methodological quality and extracted relevant data from each included study. If a study failed the qualitative assessment and statistical tests of homogeneity, it was excluded from the meta-analysis. Furthermore, a study was withdrawn from the meta-analysis of a particular outcome if that outcome was not studied or was not reported adequately. A Mantel-Haenszel analysis utilizing a random-effects model allowed for pooling of results according to graft source while accounting for the number of subjects in individual studies.

RESULTS

Nine studies were determined to be appropriate for the systematic review. Eight studies compared bone-patellar tendon-bone grafts, and one study compared quadruple-stranded hamstring grafts. Five studies were prospective comparative studies, and four were retrospective comparative studies. One study, which investigated allografts that underwent a unique sterilization process, demonstrated an allograft failure rate of 45% (thirty-eight of eighty-five). That study failed the qualitative assessment and statistical tests of homogeneity and consequently was excluded from the meta-analysis. When the outcomes from the remaining studies were pooled according to graft source, the meta-analyses of the Lysholm score, instrumented laxity measurements, and the clinical failure rate estimated mean differences and odds ratios that were not significant. These findings were robust during the sensitivity analysis, which varied the included studies or variables on the basis of graft type, instrumented laxity cut-off value, secondary sterilization technique, duration of follow-up, mean patient age, and study methodology.

CONCLUSIONS

In general, the short-term clinical outcomes of anterior cruciate reconstruction with allograft were not significantly different from those with autograft. However, it is important to note that none of these nonrandomized studies stratified outcomes according to age or utilized multivariable modeling to mathematically control for age (or any other possible confounder, such as activity level, that is not equally distributed in the two treatment groups). Understanding these limitations of the best available evidence, the surgeon may incorporate the results of the present systematic review into the informed-consent and shared-decision-making process in order to individualize optimum patient care.

What do we really know about allografts?

The use of allografts in sports medicine is becoming increasingly popular, and, therefore, this issue of Clinics in Sports Medicine is dedicated to the use of allografts in sports medicine. The majority of indications are related to the use of soft tissue grafts for ligament reconstruction, osteochondral (OC) allografts for articular surface reconstruction, and meniscal allografts for meniscal transplantation. There is an increasing amount of science and literature dealing with healing and outcomes, but many questions still remain. There are a number of issues, controversies, and lack of long-term outcomes to make definitive statements on what is really known about allograft use in sports medicine.