Cortical Fixation Devices Research Articles

Suture disc adjustable suspensory fixation device – A cost-effective technique for tibial cortical fixation in cruciate ligament reconstruction

Cruciate ligament reconstruction with adjustable suspensory devices at the femur and tibia allows graft tensioning at both ends, but it is costly due to the tibial suspensory device. To overcome the cost, the author describes a technique where the adjustable suspensory cortical fixation device can be made with a suture disc and an ultra-high-molecular-weight polyethylene suture, which is simple, cost-effective, and making it reproducible even with less experienced arthroscopy surgeons.

Adjustable Cortical Fixation Repair Is a Safe and Effective Technique for Quadriceps Tendon Rupture

To report the clinical outcomes of quadriceps tendon repair using adjustable cortical fixation devices at a minimum 2-year follow-up. A retrospective chart review identified patients who underwent quadriceps tendon repair using adjustable cortical fixation devices between January 2017 and March 2020. Patients with a partial tendon rupture were excluded. Demographic and injury-specific variables were gathered preoperatively and postoperatively from the electronic medical record and patient-reported outcomes (Lysholm Knee Questionnaire, Lower Extremity Functional Scale, and SF-12) were collected via telephone at a minimum of 2 years postoperatively. Fourteen quadriceps tendon repairs were included in a total of 13 patients. The average time to follow-up was 3.5 ± 1.2 years with a range of 1.9 to 5.7 years. The mean age of this cohort was 55.7 ± 11.6 years, and the mean body mass index was 32.9 ± 6.0. Ten injuries (71.4%) were sustained by mechanical fall, 2 patients (14.3%) suffered a direct blow to the knee, and 2 patients (14.3%) reported a noncontact injury mechanism. Thirteen quadriceps ruptures (13/14, 92.9%) underwent surgery within 10 days of their injury. One knee (7.1%) had a postoperative extensor lag of 5°, whereas another knee (7.1%) required a reoperation for manipulation under anesthesia and arthroscopic lysis of adhesions at 3 months' postoperatively. None of the included patients (0.0%) developed a tendon re-rupture, venous thromboembolism, delayed wound healing, surgical-site infection, neuropraxia or nerve injury, hardware irritation, patella fracture, or heterotopic ossification. In this study, adjustable cortical fixation was a safe and effective surgical technique for quadriceps tendon repair, with adequate restoration of quadriceps function and a low rate of adverse events at 2 years postoperatively. Level IV, therapeutic case series.

Superior clinical results for early arthroscopic treatment of grade IIIb and V acromioclavicular joint instability compared to delayed operative treatment.

Arthroscopy-assisted cortical fixation devices have been increasingly used in the operative management of both acute and chronic cases of acromioclavicular joint instability (ACJI). It has been hypothesized that delayed surgical management leads to inferior clinical and radiologic outcomes compared to acute treatment. The purpose of this study is to compare clinical and radiologic outcomes, scapula dyskinesia, and failure or revision rates of arthroscopically treated acute and chronic ACJI. This retrospective study of prospectively collected data included all surgically treated patients with grade IIIb and V chronic ACJI between 2013 and 2017, matched 1:1 to a group of acute grade IIIb and V ACJI patients treated during the same time period. Chronic ACJI was defined as delayed surgical treatment >21 days after injury. Chronic cases received an additional hamstring autograft next to the suture pulley systems. Follow-up was obtained at an average of 3.2 years (range: 1.4-6.2). Clinical outcome scores included the Constant-Murley Score (CMS), Taft Score (TF), Nottingham Clavicle Score (NCS), ACJI Score, Sick Scapula Score (SSS), Subjective Shoulder Value (SSV), Subjective Shoulder Test (SST), American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) score, and the visual analog scale pain score. Radiologic follow-up was obtained pre- and postoperatively and at final follow-up. The 2-year results were compared to the results of a 1:1 matched-pair group comprising patients who were treated with an acute ACJI during the same period. Thirty-three (80.5%) of 41 chronic ACJI cases were available for follow-up and were compared with 33 matched-pair cases of acute ACJI (of 41). The clinical scores were significantly better in the acute cohort for the CMS (92±8 vs. 88±8, P=.030), ASES (91±13 vs. 85±13, P=.002), SSS (1.4±1.6 vs. 3.4±2.5, P=.0004), NCS (86±13 vs. 81±13, P=.049), TF (9.9±1.9 vs. 9.0±2.1, P=.030), and ACJI (83±13 vs. 75±1, P=.003). In contrast to the chronic cohort, the acute cohort illustrated a significant loss of reduction at follow-up (P=.020). Based on the results of this study, early arthroscopy-assisted operative treatment of grade IIIb and V ACJIs seems superior to delayed surgical intervention of grade IIIb and V ACJIs. Furthermore, an additional autograft loop leads to less loss of reduction compared with suture pulley/suspensory loop fixation standalones.

Biomechanical Evaluation of TensionLoc Versus the Double Spike Plate for ACL Graft Tibial Fixation.

The optimal tibial fixation of anterior cruciate ligament (ACL) reconstruction (ACLR) grafts remains controversial. The purpose of this study was to compare the biomechanical characteristics of the TensionLoc (TL) cortical fixation device with the Double Spike Plate (DSP) fixation device for ACL tibial fixation using both bone-patellar tendon-bone (BTB) and quadriceps grafts. It was hypothesized that there would be no differences in biomechanical characteristics between the fixation devices regardless of graft type. Controlled laboratory study. ACLR was performed on 14 matched-pair cadaveric knee specimens-7 pairs using quadriceps grafts (n = 3 male cadaveric knee specimens; n = 4 female cadaveric knee specimens; age, 51 ± 8 years) and 7 pairs using BTB grafts (n = 3 male cadaveric knee specimens; n = 4 female cadaveric knee specimens; age, 50 ± 7 years). One side of each pair was randomized to receive DSP fixation, and the contralateral side received TL fixation. Specimens underwent cyclic ramp loading (10 cycles each at 50-100 N, 50-250 N, and 50-400 N), followed by load-to-failure testing, with the tensile force in line with the tibial tunnel. Results between the 2 fixation types were compared with a paired t test. For the quadriceps graft, there were no significant differences in cyclic loading or load-to-failure characteristics between fixation types (P≥ .092 for all parameters). For the BTB graft, TL fixation resulted in higher stiffness than DSP at all cyclic testing cycles except for cycle 1 during 100-N loading and had lower displacement at 250-N loading (3.4 ± 0.1 vs 5.4 ± 0.3 mm; P = .045). For load to failure, TL fixation resulted in higher stiffness than DSP fixation (232 ± 3.1 vs 188.4 ± 6.4 N/mm; P = .046); however, all other load-to-failure parameters were not statistically different (P≥ .135 for all parameters). With the quadriceps tendon graft, there were no significant differences in biomechanical characteristics between TL and DSP ACL tibial fixations; however, with BTB grafts, the TL tibial fixation demonstrated greater biomechanical integrity than the DSP tibial fixation. The TL fixation device may provide an alternative ACL tibial fixation option for BTB and soft tissue grafts.

Arthroscopic Primary Repair of Posterior Cruciate Ligament Using Ring Suture Attached to Adjustable Loop Device

Posterior cruciate ligament (PCL) injuries occur most often in the setting of a multiligamentous injured knee and are frequently the result of high-energy trauma. For severe and multiligamentous PCL injuries, surgical intervention is recommended. Although PCL reconstruction has traditionally been the standard treatment, arthroscopic primary PCL repair has been revisited over the past few years for proximal tears with sufficient tissue quality. Current PCL repair techniques report two technical issues: the risk of suture abrasion/laceration during the stitching process, and the inability to retension the ligament after fixation with either suture anchors or ligament buttons. In this technical note, we describe the surgical technique of arthroscopic primary repair of proximal PCL tears using a looping ring suture device (FiberRing), combined with an adjustable loop cortical fixation device (ACL Repair TightRope). The goals of this technique are to offer a minimally invasive option to preserve the native PCL and to avoid the observed shortcomings of other arthroscopic primary repair techniques.

Anatomical rectangular tunnel anterior cruciate ligament reconstruction provides excellent clinical outcomes.

The purpose of this study was to prospectively evaluate the clinical outcomes following anatomical rectangular tunnel anterior cruciate ligament (ACL) reconstruction with a bone-patellar tendon-bone (BTB) graft using an adjustable-length femoral cortical fixation device with enough patients and a high follow-up rate. This study included 125 patients who underwent anatomical rectangular tunnel ACL reconstruction with a BTB graft. A BTB TightRope® was used for femoral graft fixation. Clinical evaluations were performed more than 2years after surgery using the International Knee Documentation Committee (IKDC) Form. Patients interviewed by telephone were only subjectively evaluated. The side-to-side difference in anterior laxity at a manual maximum force was measured using the KT-2000 Arthrometer®. Among the 125 patients, 99 were ultimately included and 26 were lost to follow-up (follow-up rate: 79%). Eight patients had re-tear (re-tear rate: 8%) and six patients had ACL injuries to the contralateral knee. Three patients did not follow our rehabilitation programme. One patient suffered septic arthritis. These 18 patients were considered ineligible for clinical evaluations. Therefore, clinical evaluations were performed in 81 of the 99 patients (64 were available for direct follow-up and 17 were available for a telephone interview). The follow-up period was 30 ± 10months (range 24-68months). According to the IKDC subjective assessment, 48 (59%) and 33 (41%) knees were graded as normal and nearly normal, respectively. A loss of extension (3°-5°) was observed in five patients (8%), whereas one patient (2%) exhibited a loss of flexion (3°-5°). The Lachman test was negative in 63 patients (98%). The pivot shift test was negative in 59 patients (92%). The side-to-side difference in KT value was 0.4 ± 0.7mm (range - 1-4mm). Anatomical rectangular tunnel ACL reconstruction with a BTB graft using an adjustable-length femoral cortical fixation device provided excellent clinical outcomes both subjectively and objectively more than 2years after surgery, whereas 8 of the 99 patients had re-tear of the graft. The adjustable-length femoral cortical fixation device could be safely used in anatomical rectangular tunnel ACL reconstruction with a BTB graft. III.

Adjustable Cortical Fixation Device for Quadriceps Tendon Repair: A Cadaveric Biomechanical Study.

Background:Adjustable cortical fixation devices have demonstrated utility in orthopaedic applications, such as ankle syndesmosis repair.Purpose:To assess the cyclic gap formation of a quadriceps tendon repair technique using an adjustable cortical fixation device compared with repair with knotless suture anchors and suture tape, a modification of conventional suture anchor repair.Study Design:Controlled laboratory study.Methods:Eight fresh-frozen matched pairs of cadaveric knees were used. Specimens in each pair were randomized to undergo either modified suture anchor repair (control) or adjustable cortical fixation repair. The control repair was performed as previously described. The experimental repair was performed using 2 No. 2 FiberWire sutures placed into the quadriceps tendon in a running locked Krackow configuration and 2 adjustable loop devices passed through transosseous tunnels. The lagging strands of the devices were tensioned to seat the cortical fixation buttons at the inferior patellar pole and then tied to the free Krackow strands at the superior pole to complete the repair. The mean plastic gap (permanent tendon displacement that did not recover with cyclic extension) and mean maximum gap (peak displacement that occurred with cyclic knee flexion and partially recovered with extension) were evaluated during cyclic loading for 500 cycles of full knee extension to 90° of flexion.Results:At all testing intervals, the mean plastic gap was significantly smaller for the cortical fixation group versus the suture anchor group (P < .02). Similarly, the mean maximum gap was significantly smaller for the cortical fixation specimens at all testing intervals (P < .01). After cyclic loading, the mean maximum gap was significantly smaller in the cortical fixation group (4.80 ± 1.56 mm) versus the suture anchor group (8.47 ± 1.47 mm; P = < .001). The mean plastic gap was also significantly smaller in the cortical fixation versus the suture anchor group (3.25 ± 1.10 mm vs 6.57 ± 1.62 mm, respectively; P = < .001).Conclusion:Quadriceps tendon repair using an adjustable cortical fixation device demonstrated superior biomechanical properties in cyclic displacement testing compared with repair using the suture anchor technique.Clinical Relevance:These results suggest that an adjustable cortical fixation device is a biomechanically viable alternative for quadriceps tendon repair.

Biomechanical Evaluation of a Novel Loop Retention Mechanism for Cortical Graft Fixation in ACL Reconstruction.

Background:Implant fixation by means of a cortical fixation device (CFD) has become a routine procedure in anterior cruciate ligament reconstruction. There is no clear consensus whether adjustable-length CFDs are more susceptible to loop lengthening when compared with pretied fixed-length CFDs.Purpose:To assess biomechanical performance measures of 3 types of CFDs when subjected to various loading protocols.Study Design:Controlled laboratory study.Methods:Three types of CFDs underwent biomechanical testing: 1 fixed length and 2 adjustable length. One of the adjustable-length devices is based on the so-called finger trap mechanism, and the other is based on a modified sling lock mechanism. A device-only test of 5000 cycles (n = 8 per group) and a tendon-device test of 1000 cycles (n = 8 per group) with lower and upper force limits of 50 and 250 N, respectively, were applied, followed by ramp-to-failure testing. Adjustable-length devices then underwent further cyclic testing with complete loop unloading (n = 5 per group) at each cycle, as well as fatigue testing (n = 3 per group) over a total of 1 million cycles. Derived mechanical parameters were compared among the devices for statistical significance using Kruskal-Wallis analysis of variance followed by post hoc Mann-Whitney U testing with Bonferroni correction.Results:All CFDs showed elongation <2 mm after 5000 cycles when tested in an isolated manner and withstood ultimate tensile forces in excess of estimated peak in vivo forces. In both device-only and tendon-device tests, differences in cyclic performance were found among the devices, favoring adjustable-length fixation devices over the fixed-length device. Completely unloading the suspension loops, however, led to excessive loop lengthening of the finger trap device, whereas the modified sling lock device remained stable throughout the test. The fixed-length device displayed superior ultimate strength over both adjustable-length devices. Both adjustable-length devices showed adequate fatigue behavior during high-cyclic testing.Conclusion:All tested devices successfully prevented critical construct elongation when tested with constant tension and withstood ultimate loads in excess of estimated in vivo forces during the rehabilitation phase. The finger trap device gradually lengthened excessively when completely unloaded during cyclic testing.Clinical Relevance:Critical loop lengthening may occur if adjustable-length devices based on the finger trap mechanism are repeatedly unloaded in situ.

Evaluation of Adjustable Loop Suspensory Anterior Cruciate Ligament Fixation Devices

Abstract Along with increasing enthusiasm for sports comes an increase of sport related injuries. One of the most common injuries in the human knee is the tear of the anterior cruciate ligament (ACL). The selection of a graft fixation device is an important factor that determines the outcome of an anterior cruciate ligament reconstruction. Before the healing process is completed, the graft is dependent on tibial and femoral fixation devices to maintain normal ACL graft tension. Among various devices, the use of an adjustable loop suspensory fixation device (ALD) in soft-tissue graft reconstruction attracts current interest. An advantage of the ALD is the ability to draw the graft to the depth of the bone tunnel to achieve adequate graft tension while minimizing the empty space in the tunnel. In this study a comprehensive controlled laboratory investigation is performed to examine the biomechanical properties of commonly used cortical fixation devices, with the aim of implementing a standard testing procedure for adjustable loop devices. The procedure consists of three test series, a loop shortening test and two different stability test series (singe device and tendon device test). Those test series are used to compare the performance of a new ALD from Arthrex (Naples, USA) with five competitor devices already on the market. In order to obtain representative results eight samples of each device are tested. In comparison to the previously performed studies, a complete unloading is applied in the stability tests, which allows for a detailed examination of the ALDs locking mechanisms in dynamically loaded test situations. Furthermore, the performed loop shortening tests reveal important aspects, such as the shortening accuracy and settling effects of the loops, that are not found in previous studies. Therefore, the used test protocol can be recommended for further testing.

Excellent bone plug–socket integration at 8 weeks after anterior cruciate ligament reconstruction using an adjustable-length loop cortical fixation device

ObjectivesRecently, adjustable-length loop cortical fixation devices (ALCFDs) have been developed. However, they are not frequently used for bone–patellar tendon–bone (BTB) grafting, mainly because it is uncertain whether an ALCFD enables sufficient integration of the bone plug. Thus, the purpose of this study was to evaluate bone plug–socket integration in anterior cruciate ligament reconstruction (ACL-R) with an ALCFD.MethodsTwenty consecutive patients with a mean age of 25±10 years underwent primary anatomic rectangular tunnel (ART) ACL-R with a BTB graft using BTB TightRope. The operated knees were evaluated by CT at 4 weeks and 8 weeks postoperatively. Union between the bone plug and the socket wall were assessed on 30 evaluation planes. No border between the plug and the socket wall, or trabecular continuity, were defined as complete union and a visible gap of >1 mm as incomplete union. When complete union was observed on >20, 11–20, 5–10 or <5 of the evaluation planes, bone integration was graded as excellent, good, fair or poor, respectively. In addition, the interface area between the plug and the socket wall was assessed by CT value index. Clinical evaluation was performed at 2 years postoperatively using the International Knee Documentation Committee (IKDC) form.ResultsThe proportion of patients with excellent bone integration was 20% at 4 weeks and 85% at 8 weeks, showing a significant difference (p=0.00015). Moreover, the CT value index of the interface area at 4 weeks was 25.8%±11.8% and that at 8 weeks was 15.3%±9.0%, again showing a significant difference (p=0.005). These suggest that bone integration of the interface area progresses over time and adequate at 8 weeks. Clinically, all 16 patients examined directly were rated their knees as normal or nearly normal with a mean side-to-side difference in anterior laxity at manual maximum force by KT-2000 of 0.2±0.3 mm.ConclusionExcellent bone plug–socket integration was observed at 8 weeks after ART ACL-R using an ALCFD with satisfactory clinical results. An ALCFD could be safely applied for ART ACL-R.Level of evidence4 (case series).

Adjustable buttons for ACL graft cortical fixation partially fail with cyclic loading and unloading.

Despite good initial pullout strength, it is unclear whether adjustable button (AB) devices for anterior cruciate ligament (ACL) soft-tissue graft fixation, which are based on the Chinese finger trap technique, resist cyclic loading. Furthermore, they have never been tested in a cyclic protocol including complete unloading. It was hypothesized, that the displacement of AB devices with the Chinese finger trap technique would be greater than that of continuous suture loop devices and other available AB mechanisms in a cyclic loading with complete unloading protocol. ACL reconstruction was performed in a porcine knee model using three different types of cortical fixation devices: two different AB devices that use the Chinese finger trap design, one AB device that uses a locked suture loop mechanism and two different continuous loop devices as control groups (n = 40). Specimens were mounted in a material-testing machine (Instron Inc.) that permitted 2500 loading and complete unloading cycles to a maximum of 250N, as well as continuous elongation recording. A one-way ANOVA was performed for statistical analysis. The displacement of ABs with a Chinese finger trap loop (mean 8.1; SD 1.5mm and mean 6.1; SD 1.4mm) was significantly greater than that of AB with a locked suture loop (mean 4.7; SD 1.0mm; p < 0.05) and devices with a continuous loop (mean 4.1; SD 0.5mm and mean 4.4, SD 0.3mm; p < 0.01). No significant differences were detected between the ABs with a locked suture loop and the continuous loops. Cyclic loading and unloading of AB using the Chinese finger trap technique leads to significantly greater construct lengthening compared with other devices. Complete unloading of the ACL is very likely to occur during rehabilitation after ACL reconstruction. Lengthening of the AB device due to cyclic loading might be a potential mode of failure of the ACL graft fixation. Therefore, when using an AB femoral fixation technique, a locked suture loop design or a careful rehabilitation protocol should be considered.

Use of a Modified All-Epiphyseal Technique for Anterior Cruciate Ligament Reconstruction in the Skeletally Immature Patient.

Background:Multiple surgical approaches have been described for the management of anterior cruciate ligament (ACL) tears in skeletally immature patients.Purpose:To provide a detailed description of a modified all-epiphyseal ACL reconstruction and report early outcomes and complications with this new technique.Study Design:Case series; Level of evidence, 4.Methods:A retrospective review of all skeletally immature patients undergoing ACL reconstruction via a modified all-epiphyseal technique prior to July 2015 was performed. Skeletally immature male patients with a bone age of 8 to 15 years and female patients with a bone age of 8 to 12 years were selectively indicated for this procedure. The surgical technique involved an all-epiphyseal femoral tunnel drilled parallel and distal to the physis as well as an all-epiphyseal tibial tunnel. Both tunnels were placed in the anatomic footprint of the ACL. Tibial fixation was achieved first with a suspensory cortical fixation device followed by fixation on the femur with an interference screw.Results:During the study period, 30 patients with a mean bone age of 11.8 years underwent ACL reconstruction with this physeal-sparing technique; 26 patients (87%) achieved a minimum follow-up of 2 years. At final follow-up, the mean Lysholm score, Single Assessment Numeric Evaluation score, patient satisfaction, return-to-sport rate, and Tegner activity score were 93, 89, 9.2, 94%, and 7.6, respectively. Four graft failures (15%) and 3 (12%) contralateral ACL tears were identified. One patient was noted to have a 12-mm leg-length discrepancy at final follow-up, which required no additional treatment. No other leg-length discrepancies or angular deformities were identified.Conclusion:The modified all-epiphyseal ACL reconstruction technique achieved good functional outcomes, a high rate of return to sport, low failure rates, and low physeal injury rates at a mean follow-up of 3.2 years. Skeletally immature patients with an ACL tear requiring reconstruction pose a unique challenge for sports medicine clinicians. While several previous approaches have been described for this patient population, the proposed benefits of this new technique are that it is anatomic, it is physeal sparing, it uses osseous tunnels, and it provides good initial graft fixation strength.

Surgical Management of Proximal Tibiofibular Joint Instability Using an Adjustable Loop, Cortical Fixation Device

A technique for proximal tibiofibular joint stabilization using an adjustable loop, cortical fixation device is presented. A standard diagnostic arthroscopy is performed to exclude intra-articular pathology. After arthroscopy, a 5-cm posterior-based curvilinear incision is made over the fibular head with dissection of the fascia and decompression of the common peroneal nerve ensuring adequate exposure of the fibular head. A guidewire is placed across 4 cortices using fluoroscopic guidance from the fibular head to the anteromedial tibia. A cannulated drill bit is guided through the 4 cortices. A shuttle wire carrying the adjustable loop, cortical fixation device is fed from lateral to medial and through the skin until the medial cortical button is deployed. The device is tightened until the lateral circular cortical button is secured on the fibula. Fluoroscopy is performed to confirm the button position. The device is secured after tensioning by tying the sutures. To confirm joint stabilization, a shuck test can be performed. If a second fixation device is necessary, this procedure can be repeated distally to the first.

Remnant-preserving, selective single-bundle augmentation of the anterior cruciate ligament using a bone–patellar tendon–bone autograft: A technical note

BackgroundTo the best of our knowledge, there has been no detailed study on bone–patellar tendon–bone (BTB) grafts for remnant-preserving, selective-bundle anterior cruciate ligament (ACL) augmentation. Therefore, we aimed to develop such a technique using a BTB graft. MethodA total of five patients underwent surgery using the presented procedure. These patients were young, male, and with high body mass index, and hence required very high durability of reconstructed ACL. A femoral bone tunnel was created using the inside-out technique via an accessory far-medial portal, protecting the remnant using a probe, regardless of the presence of an anteromedial (AM) or posterolateral (PL) tunnel. A single tibial tunnel was drilled at the center of the AM or PL attachment and two transverse skin incisions were made in the ipsilateral knee. The central third of the patellar tendon attached to a patellar and tibial bone plug autograft with a width of seven millimeters was harvested by subcutaneous tunneling. The femoral side was fixed using a cortical fixation device for BTB and the tibial bone plug was fixed using an interference screw with the knee at an angle of 20° of flexion by applying maximal manual traction. ResultsBone tunnel enlargement, which was measured by computed digital radiography, was not observed in all cases. A BTB autograft for remnant-preserving, selective-bundle ACL augmentation offers reduced risk of tunnel enlargement. ConclusionThe presented procedure might be considered one of the potentially available options for patients with ACL partial tear who require very high durability of reconstructed ACL. Level of evidence5

Biomechanical and Computed Tomography Analysis of Adjustable Femoral Cortical Fixation Devices for Anterior Cruciate Ligament Reconstruction in a Cadaveric Human Knee Model

To evaluate and compare two adjustable femoral cortical suspensory fixation devices used for anterior cruciate ligament reconstruction through a novel, direct computed tomography (CT) analysis metric and biomechanical laxity testing in a matched cadaveric human knee study. Anterior cruciate ligament reconstructions with bovine tendon grafts were performed using two adjustable femoral cortical suspensory fixation devices (RigidLoop Adjustable [DePuy Synthes Mitek, Raynham, MA] and TightRope [Arthrex, Naples, FL]) in 12 knees (6 matched pairs). A mechanical testing series was used to determine each knee's laxity in the intact condition. After reconstruction, each specimen was again tested for laxity and also imaged with CT. The laxity testing and CT imaging were then repeated after 1,000 cycles of anteroposterior loading on each knee to compare changes in laxity for the two fixation devices and to visualize changes in button-to-graft distance migration through a three-dimensional CT imaging method. No significant differences were found between the two fixation groups' laxity measures after reconstruction (all P values ≥ .620) or after cycling (all P values ≥ .211) at any flexion angle. In addition, no significant differences were found between the two groups regarding button-to-graft distance migration (P = .773; mean, 0.61 ± 0.6 mm [95% confidence interval, -0.1 to 1.3 mm] in RigidLoop Adjustable group and 0.53 ± 0.6 mm [95% confidence interval, -0.1 to 1.2 mm] in TightRope group). There were no significant differences between the two femoral cortical suspensory adjustable-loop devices regarding laxity outcomes or loop displacement as measured by button-to-graft distance migration. Use of either of the adjustable-loop cortical suspensory devices in our analysis would appear to produce similar, acceptable laxity outcomes and minimal effects in terms of device-related loop displacement.

Anatomic ACL reconstruction: rectangular tunnel/bone-patellar tendon-bone or triple-bundle/semitendinosus tendon grafting.

Anatomic ACL reconstruction is the reasonable approach to restore stability without loss of motion after ACL tear. To mimic the normal ACL like a ribbon, our preferred procedures is the anatomic rectangular tunnel (ART) technique with a bone-patellar tendon-bone (BTB) graft or the anatomic triple bundle (ATB) procedure with a hamstring (HS) tendon graft. It is important to create tunnel apertures inside the attachment areas to lessen the tunnel widening. To identify the crescent-shaped ACL femoral attachment area, the upper cartilage margin, the posterior cartilage margin and the resident’s ridge are used as landmarks. To delineate the C-shaped tibial insertion, medial intercondylar ridge, Parson’s knob and anterior horn of the lateral meniscus are helpful. In ART-BTB procedure which is suitable for male patients engaged in contact sports, the parallelepiped tunnels with rectangular apertures are made within the femoral and tibial attachment areas. In ATB-HS technique which is mainly applied to female athletes engaged in non-contact sports including skiing or basketball, 2 femoral and 3 tibial round tunnels are created inside the attachment areas. These techniques make it possible for the grafts to run as the native ACL without impingement to the notch or PCL. After femoral fixation with an interference screw or cortical fixation devices including Endobutton, the graft is pretensioned in situ by repetitive manual pulls at 15–20° of flexion, monitoring the graft tension with tensioners on a tensioning boot installed on the calf. Tibial fixation with pullout sutures is achieved using Double Spike Plate and a screw at the pre-determined amount of tension of 10–20N. While better outcomes with less failure rate are being obtained compared to those in the past, higher graft tear rate remains a problem. Improved preventive training may be required to avoid secondary ACL injuries.

Clinical outcomes using translateral all-inside ACL reconstruction

Introduction Current practices in anterior cruciate ligament (ACL) reconstruction fail to restore normal knee kinematics. In vitro studies demonstrate biomechanical advantages of anatomic positioning in single bundle reconstructions over traditional techniques. We present the clinical outcomes in a series of 237 patients, mean age 32.2 years (range 10–74) who underwent anatomic all-inside ACL reconstruction, using the translateral surgical technique. Methods The semitendinosus alone is harvested, quadrupled and attached in series to two adjustable suspensory cortical fixation devices. Anatomic placement on the femur is achieved using the validated direct measurement technique. Femoral and tibial sockets are created with a retrograde drill. Patients were evaluated preoperatively and at 6, 12 and 24 months postoperatively using the KOOS, Tegner and Lysholm scoring indices. Knee laxity was assessed using KT-1000 along with goniometric measurement of range or motion. Results Overall complication rate 8.4% (20 cases). There were 9 graft failures (3.8%) – 6 due to significant postoperative trauma. Other complications include 5 superficial wound infections treated with oral antibiotics, 2 haemarthroses, 3 knees with postoperative stiffness requiring manipulation and 1 patient who developed chronic regional pain syndrome. Mean increase at 1 year in KOOS, 26.3 points; Tegner, 1.4 levels; and Lysholm, 30.4 points. Mean range of movement at 12 months, 1o hyperextension to 137o flexion. KT-1000 improved to 3.1 mm side-to-side difference.

Kinematics and Contact Stress Analysis of Pediatric Anterior Cruciate Ligament Reconstructions: Do the All-Epiphyseal and Complete Transphyseal Reconstructions Restore Anterior and Rotational Stability?

Objectives:Pediatric ACL reconstruction techniques have been described that can restore stability and contact pressures to the ACL deficient knee. The complete transphyseal (CT) reconstruction uses a more vertical graft to minimize physeal damage whereas the all-epiphyseal (AE) reconstruction uses sockets beginning at the ACL footprint and avoids the physis. The CT reconstruction may leave the knee unstable against pivot shift loads and leave contact stress abnormalities, whereas the AE may better resist rotational loads. A direct comparison of the kinematics and contact stresses after AE and CT ACL reconstructions have not been studied.Hypotheses:Both the AE and CT reconstructions will restore translational kinematics but the AE technique will better restore rotational kinematics. The AE reconstruction will more closely replicate the contact stresses of the ACL intact knee compared to the CT reconstruction because of the restoration of rotational stability.Methods:Seven fresh-frozen human cadaveric knees were tested using a robotic manipulator. Each of the specimens was tested with the intact ACL, the deficient ACL, and after each reconstruction. The AE utilized sockets oriented within the epiphysis. The CT had more central and vertical sockets in both the tibia and femur. Both reconstructions were fixed with suspensory cortical fixation devices using an all-inside technique and 10 mm diameter hamstring grafts. Reconstruction order was randomized. Anterior stability was assessed with 134N anterior force at 30, 90° of knee flexion simulating the Lachman and anterior drawer exams, respectively. The pivot shift exam was simulated by applying a combined 8 Nm and 4 Nm of abduction and internal rotation, respectively, at 15° of knee flexion. Tibiofemoral motions were recorded and mean contact stresses generated within the tibiofemoral compartments were measured using contact stress transducers. Outcomes were compared across conditions of the ACL using ANOVA and Kruskall-Wallis for normally and non-normally distributed data, respectively.Results:Both reconstructions had significantly decreased anterior translation, medial translation, and internal rotation compared to the ACL deficient knee (Figure 1) in response to loads simulating the pivot shift. However, internal rotation and medial translation remained elevated beyond intact levels following the CT reconstruction by 10.5% (P<0.05) and by 75.3% (P<0.05), respectively. During the simulated anterior drawer test at 30° and 90° of knee flexion both reconstructions restored anterior translation to that of the ACL intact knee. In response to the pivot-shift, the AE reconstruction decreased lateral posterior contact stresses compared to the ACL-deficient knee. However, following CT reconstruction, they remained elevated compared to the ACL-competent knee (P<0.05). Both reconstruction techniques offloaded the posterior aspect of the medial tibial plateau compared to the ACL deficient knee in response to anterior loading at 30 and 90° of knee flexion.Conclusion:While both AE and CT reconstructions reduced anterior translations and posteromedial contact stresses in response to an anterior load, the AE technique more effectively reduced axial rotation and posterolateral contact stresses during a simulated pivot shift exam. These findings are likely due to the more oblique orientation of the AE graft, which makes it a more effective stabilizer to rotational and medial-lateral loads.

Contact Stress and Kinematic Analysis of All-Epiphyseal and Over-the-Top Pediatric Reconstruction Techniques for the Anterior Cruciate Ligament

Background: Adult anterior cruciate ligament (ACL) reconstruction techniques may be inappropriate to treat skeletally immature patients because of the risk of physeal complications. “Physeal-sparing” reconstruction techniques exist, but their ability to restore knee stability and contact mechanics is not well understood. Purpose: (1) To assess the ability of the all-epiphyseal (AE) and over-the-top (OT) reconstruction techniques to restore knee kinematics, (2) to assess whether these reconstruction techniques decrease the high posterior contact stresses seen with ACL deficiency, and (3) to determine whether the AE or OT technique produces abnormal tibiofemoral contact stresses. Study Design: Controlled laboratory study. Methods: Ten fresh-frozen human cadaveric knees were tested using a robotic manipulator. Tibiofemoral motions were recorded with the ACL intact, after sectioning the ACL, and after both reconstructions in each of the 10 specimens. The AE technique consisted of tunnels exclusively within the epiphysis and was fixed with suspensory cortical fixation devices. The OT procedure consisted of a central and vertical tibial tunnel with an over-the-top femoral position and was fixed with staples and posts on both ends. Anterior stability was assessed with 134-N anterior force at 0°, 15°, 30°, 60°, and 90° of knee flexion. Rotational stability was assessed with combined 8 N·m and 4 N·m of abduction and internal rotation, respectively, at 5°, 15°, and 30° of knee flexion. Results: Both reconstruction techniques off-loaded the posterior aspect of the tibial plateau compared with the ACL-deficient knee in response to both anterior loads and combined moments as demonstrated by reduced contact stresses in this region at all flexion angles. Compared with the ACL-intact condition, both the AE and OT procedures had increased posteromedial contact stresses in response to anterior load at some flexion angles, and the OT technique had increased peripheral posterolateral contact stresses at 15° in response to combined moments. Neither reconstruction technique completely restored the midjoint contact stresses. Both techniques restored anterior stability at flexion angles ≤30°; however, neither restored anterior stability at 60° and 90° of flexion. Both reconstruction techniques restored coupled anterior translation under combined moments. Additionally, the AE procedure overconstrained internal rotation in response to combined moments by 12% at 15° of flexion. Conclusion: Both reconstruction techniques provide anterior and rotational stability and decrease posterior joint contact stresses compared with the ACL-deficient knee. However, neither restored the contact mechanics and kinematics of the ACL-intact knee. Clinical Relevance: Because the AE reconstruction technique has clinical advantages over the OT procedure, the results support this technique as a potential candidate for use in the skeletally immature athlete.

Flexible Reamers in Anatomic ACL Reconstruction: Effect of Knee Flexion on Femoral Tunnel Length and Latrogenic Peroneal Nerve Injury (SS-67)

The purpose of this study was to determine the effect of knee flexion angle on femoral tunnel length and distance of guide pin to critical lateral knee structures with the use of a flexible guide pin and reamer system from a standard anteromedial arthroscopic portal. We obtained 10 cadaveric knees, all of which had no evidence of prior knee surgery. The intact anterior cruciate ligament was debrided and the anatomic femoral footprint was identified. Flexible guide pins were inserted from a standard anteromedial portal in knee flexion angles of 70, 90 and 120 degrees using the same starting point. Tunnel lengths were determined for each of these guide pins at each angle. Distances from the common peroneal nerve and the origin of the fibular collateral ligament were measured for each guide pin as they exited out the lateral femoral cortex. We calculated the average tunnel lengths at various flexion angles and distances to the lateral structures for each guide pin in all of the specimens. The average femoral tunnel length was found to be statistically longer with 120 degrees of knee flexion than at 70 degrees, 38.4 mm vs. 26 mm (p=0.0001). The average tunnel length was not statistically different between the 70 and 90 degree angles (26 +/− 4.18 mm and 32.4 +/− 9.24 mm respectively, p=0.08). No guide pin injured the common peroneal nerve. The mean distance to the common peroneal nerve was 50.2 mm +/− 15.53 at 70 degree knee flexion angle. This distance was significantly lower than the 120 degree flexion angle mean of 70 mm +/− 19.20 (p=0.01). Regardless of the type of guide pin and reamer system used in anatomic ACL reconstruction, knee flexion angle determines femoral tunnel length. Longer femoral tunnels were obtained with higher knee flexion angles, similar to previous studies using rigid guide pins. With flexible guide pins lower knee flexion angles provide tunnel lengths that may be sufficient for interference screw fixation but may not allow for sufficient length for suspensory or cortical fixation devices. Flexible guide pins do not put the common peroneal nerve at risk in any flexion angle.