Femoral Socket Research Articles

Commercially Available Guides Overestimate Socket Length During Anterior and Posterior Cruciate Ligament Socket Retrograde Drilling

To objectively assess the accuracy of socket measurements taken during cruciate ligament reconstruction using a retrograde reaming technique. Six complete knee sawbone specimens were used to ream anterior and posterior cruciate ligament sockets in the femur and tibia in a retrograde fashion using a standard retrograde reaming device. The longest and shortest sides of the sockets were measured using a ruler. One-sided Wilcoxon signed-rank sum tests were used to evaluate whether the actual measured socket length matched the estimated length set on the drill guide. One fellowship-trained surgeon reamed 24 total sockets in sawbone specimens using guides. Statistical analysis revealed a significant difference between the estimated measurement and the actual shortest tunnel length in each of the sockets. The median short side socket lengths were shorter than their respective intended depths by 4 mm for the femoral anterior cruciate ligament socket, 6 mm for the femoral posterior cruciate ligament socket, 6 mm for the tibial anterior cruciate ligament socket, and 4.5 mm for the tibial posterior cruciate ligament socket. All differences were significant at α= 0.05. The estimated cruciate socket lengths reamed during ligament reconstruction using a retrograde reamer and standard intra-articular measuring instrumentation were greater than the actual measured socket lengths. Successful cruciate ligament reconstruction relies on accurate socket measurements. This study examined the accuracy of commercially available cruciate ligament socket drill guides and the implications for clinical practice, to include graft-tunnel mismatch and surface area available for healing. Surgeons may consider reaming slightly longer than estimated sockets when performing all-inside cruciate ligament reconstructions to ensure appropriate socket depth for graft fixation.

All-Inside ACL Reconstruction: Short Femoral and Tibial Socket Technique

Background: Recently, there has been an increase in interest in all-inside anterior cruciate ligament (ACL) reconstruction (ACLR). Regarding graft maturity, graft contact with the bone tunnel is important. All-inside ACLR with short femoral and tibial sockets might allow to increase the contact between the graft and the socket (ie, no interference screw and contact between the graft and bottom of the socket) and can improve graft maturing. Indications: All-inside ACLR with short sockets technique is indicated in patients with primary ACL rupture or ACL graft re-rupture. Technique Description: The patient was placed in supine position. Following examination under anesthesia, diagnostic arthroscopy was performed to assess for meniscus injuries and chondral defects. The surgical technique required 6 steps: (1) graft preparation (4-strand semitendinosus tendon, graft length was about 45 mm, grafts larger than 8 mm), (2) creating femoral socket (5-10 mm), (3) creating tibial tunnel socket (10-15 mm), (4) passing the graft, (5) tensioning the graft, and (6) graft fixation and skin closure. Patients were partial weightbearing with crutches for 3 weeks and used a hinged knee brace for 6 weeks after surgery. Return to activities was based on functional strength recovery, with a return to running targeted at 4 to 5 months after surgery. Results: All-inside ACLR with short sockets technique provides a better chance of return to preinjury level of activity with accompanied patient satisfaction as compared with anteromedial portal technique at 2 years of follow-up. This technique has favorable functional and clinical outcomes with improvement of graft maturing. Discussion/Conclusion: In conclusion, we propose that ACLR with short tibial and femoral socket technique is simple and safe with favorable clinical outcomes. This is an advantageous ACLR technique that can preserve the gracilis muscle and reduce muscle strength loss of affected limbs. In addition, the all-inside technique is circumferential filling of the socket with the graft, which might increase bone to graft contact compared with interference screws. Further study is needed to show the better clinical outcome and the earlier graft maturation compared with ordinary ACLR. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Combined ACL and Anterolateral Ligament Reconstruction Using an Adjustable-Loop Fixation Device: Surgical Technique

Background: There are several techniques for the combined reconstruction of the anterior cruciate ligament (ACL) and the anterolateral ligament (ALL), but none have shown superiority. This study aims to present a surgical technique that theoretically reduces some of the risks reported in these procedures. Indications: The main indications for the ALL reconstruction include chronic ACL injuries, revision ACL reconstruction, acute ACL injuries in patients with high-grade pivot-shift (grades 2 or 3), patients involved in pivoting sports, and generalized ligament hyperlaxity or knee hyperextension. Technique Description: Hamstring tendon autografts are used for the ACL and ALL reconstruction; a common femoral ACL and ALL tunnel is made outside-in, making a short socket. A continuous looped hamstring tendon autograft attached to one button is used. The ACL is fixed with an adjustable-loop button. Through small incisions, the tibial fixation of both grafts is performed with bioabsorbable screws. Results: We present a 19-year-old professional soccer player with an acute ACL tear, with no associated meniscal or chondral lesions. Owing to his young age and high-risk sports practice, a combined ACL and ALL reconstruction was performed. The combined ACL and ALL reconstruction with a single femoral tunnel using the hamstrings tendons graft is a well-established procedure for ACL augmentation, reducing failure rates for certain risk groups, with excellent outcomes reported. The use of an adjustable-loop button on the femur is a viable option for this kind of reconstruction with postoperative stability comparable to the interference screw, classically used for this kind of reconstruction. Discussion/Conclusion: This technique has some advantages, such as the use of a short outside-in femoral socket, thus theoretically improving healing. In addition, this lowers the risk of lateral collateral ligament injury, and since the ileotibial band graft is not used, the risk of injuring the lateral inferior genicular vessels and the peroneal nerve is theoretically reduced. Besides, using an adjustable-loop cortical button in the femur can theoretically reduce potential complications such as screw migration, soft-tissue impingement, femoral-site pain, and implant removal. Finally, the reconstruction is done with small incisions, improving the aesthetic result and postoperative pain. Considering all the aforementioned factors, this technique theoretically offers some benefits. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Lateral Collateral Ligament Reconstruction With Tensionable Loops and Suture Tape Reinforcement

Background: The posterolateral corner (PLC) is an important knee stabilizer that resists varus stress, external tibial rotation, and posterior tibial translation. Untreated PLC injuries have been shown to increase failure rates of anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) reconstructions and lead to degenerative changes. Our modified Arciero technique reconstructs the femoral insertion site and functionality of the lateral collateral ligament (LCL) and popliteal fibular ligament, components of the PLC, with an internal brace and tensionable loops. Indications: The primary indication for PLC reconstruction is identified PLC injury. Patients often have a feeling of knee instability and a varus thrust gait. PLC injury should be confirmed with imaging. Technique Description: We employed a modified Arciero technique via LCL reconstruction with tensionable loops and internal brace. We used a semitendinosus allograft truncated at 240-millimeters to avoid the graft bottoming out. A suture augment was incorporated into the graft to reinforce the LCL reconstruction construct during graft tensioning and early rehabilitation. The graft construct was then passed through the transfibular tunnel to femoral sockets at the LCL and popliteus insertions. The graft construct is then affixed to the opposite femoral cortex. The graft was then tensioned with the knee in approximately 30° of flexion, neutral to 10° of internal rotation, and a valgus force applied. This restored excellent valgus stability. Results: Fibular and tibiofibular-based constructs are common procedures for PLC reconstruction. Our LCL reconstruction with tensionable loops technique and the Arciero technique are fibular-based constructs. The fibular-based construct and the tibiofibular-based construct have been found to be biomechanically equivalent at restoring knee stability. However, fibular-based constructs, such as our LCL reconstruction with tensionable loops, were found to be less technically demanding than tibiofibular-based constructs, used fewer grafts, and required a smaller surgical approach. Conclusion: Given similar clinical outcomes, it was concluded that fibular-based constructs, such as our modified Arciero technique, may be more advantageous because of the ability to avoid some of the pitfalls of tibiofibular-based constructs. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

A Modified Technique for All-Inside Anterior Cruciate Ligament Reconstruction (ACLR): True Femoral Socket

Anterior cruciate ligament reconstruction (ACLR) performed via arthroscopy is the primary treatment for anterior cruciate ligament injury. In traditional ACLR, the surgeon must create bone tunnels in both the femur and tibia, which increases the risk of bleeding and pain. The advent of all-inside technology has introduced the concept of bone sockets. However, the femoral socket created by the traditional all-inside technique is not a true femoral socket since the tunnel ends are still connected to achieve suspensory fixation. We are dedicated to achieving a true femoral socket in the all-inside ACLR technique. The AperFix Implant fixation system offers the potential for a genuine femoral socket by securely holding the ligaments in place through compression fixation. In this report, we present an all-inside ACLR using the AperFix Implant fixation system, which allows for a single exit of the femur side tunnel. This technique effectively reduces “windshield wiper” effect, “bungee cord” effect, as well as surgical time and minimizes the risk of bleeding, pain, and local microfractures.

Revision ACL-R With Contralateral BTB Autograft and Iliotibial Band Lateral Extra-Articular Tenodesis With Interference Screw Fixation: A Technique Video

Background: Lateral extra-articular tenodesis (LET) is a reproducible and reliable technique to assist in control of rotational stability of the knee and decrease forces across an anterior cruciate ligament (ACL) graft in the setting of ACL reconstruction. Bone-tendon-bone (BTB) autograft is a common graft choice in revision ACL reconstruction. We present a technique for combining contralateral BTB autograft with LET in revision ACL reconstruction. Indications: This technique is indicated in patients undergoing ACL reconstruction who are at increased risk of graft failure, including revision cases, high-grade rotational instability, return to pivoting/cutting sports, ligamentous laxity, young age, meniscal deficiency, and hyperextension/recurvatum. Technique Description: The contralateral BTB autograft is harvested through standard fashion. We begin with the LET dissection prior to fluid infiltration in the soft tissues. A 1-cm strip of iliotibial (IT) band is harvested and whipstitched. The IT band strip is passed from anterior to posterior deep to the lateral collateral ligament (LCL). The LET socket is aimed 10° proximal and 10° anterior to limit tunnel convergence with the ACL. The LET is fixed with a tenodesis screw with the knee in neutral rotation and 30° of flexion. The ACL femoral socket is then placed, and care is taken to avoid convergence. A 10-mm tibial tunnel is drilled near the level of the posterior margin of the anterior horn of the lateral meniscus. The ACL is subsequently fixed with standard techniques. Results: The addition of LET to revision ACL has been shown to improve failure rate and outcomes. The use of contralateral patella tendon graft reduces morbidity on the operated leg. Notably, the position of the femoral LET tunnel is less important than the ACL tunnel position on the femur. If the LET is passed under the LCL, then the fixation point on femur becomes less relevant. The technique presented is a time-efficient way for combining tenodesis with revision ACL. Discussion/Conclusion: Performing a revision ACL reconstruction utilizing contralateral donor tissue with the addition of LET is a viable and reliable option for competitive athletes. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form.

Modified Lemaire Lateral Extra-Articular Tenodesis Using an Inlay Technique and All-Suture Knotless Anchor Fixation

Appreciation of persistent anterolateral rotatory instability and graft failure after anterior cruciate ligament (ACL) reconstruction procedures has led surgeons to adopt the addition of lateral extra-articular tenodesis (LET) in both the revision and primary setting. Multiple techniques have been shown to eliminate anterolateral rotatory instability and reduce forces on the ACL graft, which has translated to lower re-rupture rates and improved patient outcomes. The risk of ACL/LET tunnel convergence can potentially compromise the fixation of one or both graft reconstructions. This article describes a technique for LET fixation which minimizes the depth of the LET femoral bone socket and utilizes low-profile implants thus mitigating this risk.

Double-Bundle PCL Reconstruction in the Multiple-Ligament Injured Knee

Background: Multi-ligament knee injuries and knee dislocations are potentially devastating injuries that typically result in injury to both cruciate ligaments and variable injury to collateral ligament complexes. Indications: Surgical intervention typically leads to better patient outcomes than nonoperative management. We describe our preferred technique for bicruciate ligament reconstruction with a focus on double-bundle posterior cruciate ligament (PCL) reconstruction. Technique Description: A transtibial approach is used to drill the PCL tibial tunnel. A safety incision on the proximal medial tibia, which may incorporate the distal aspect of a medial-sided incision for medial collateral ligament (MCL) reconstruction, allows palpation of the PCL fovea for anatomic tunnel placement, protection of the posterior neurovascular structures, and egress of arthroscopic fluid during the case. This technique uses an inside-out approach for creation of the 2 femoral sockets to recreate the 2 PCL bundles. The grafts are passed in antegrade fashion, with passage and femoral fixation of the posteromedial (PM) bundle followed by the anterolateral (AL) bundle. After passage of the anterior cruciate ligament (ACL) graft and fixation on the femur in standard fashion, attention is turned to PCL tibia-sided fixation. We use a screw and spiked washer to fix the AL bundle at 90° of flexion with an anterior drawer maneuver. The PM bundle is then fixed with a polyetheretherketone (PEEK) interference screw in near full extension. Fixation of the ACL on the tibia in standard fashion completes the bicruciate ligament reconstruction. Results: In biomechanical cadaveric studies, double-bundle PCL reconstruction has been shown to more closely approximate native knee kinematics, with more restraint to posterior translation at all knee flexion angles and less internal rotation laxity at higher knee flexion angles. In clinical results, both single-bundle and double-bundle reconstructions improve knee stability and patient-reported outcomes. Double-bundle PCL reconstruction may provide improved objective posterior tibial stability and objective International Knee Documentation Committee (IKDC) scores. Discussion: Double-bundle PCL reconstruction can be performed efficiently with good outcomes and potentially less residual posterior translation or internal rotation laxity than single-bundle PCL reconstruction. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

A Surgical Technique for Anterior Cruciate Ligament Reconstruction Using Semitendinosus Graft: An All-Inside Transfemoral Approach

Given the paucity of reports on all-inside reconstruction procedures via the transfemoral approach, we describe a minimally invasive, all-inside transfemoral technique that enables creating femoral and tibial sockets from the intra-articular cavity. Our transfemoral approach makes it possible to sequentially create femoral and tibial sockets using the same reamer bit, while a single drilling guide is set in place. Our custom socket drilling guide was designed to integrate with a tibial tunnel guide, which helped locate the tunnel exit at an anatomically acceptable location. The advantages of this method include easy and precise positioning of the femoral tunnel, narrow tibial tunnel, minimal damage to the intramedullary trabecular bone integrity, and low postoperative risks of pain, bleeding, and infections.

Radiographic Changes After Medial Patellofemoral Ligament Reconstruction in Skeletally Immature Patients Compared With an Age- and Sex-Matched Cohort

Background: Despite recent evidence that medial patellofemoral ligament reconstruction (MPFLR) in the skeletally immature patient is both safe and effective, there are limited data evaluating postoperative coronal- and sagittal-plane growth and radiographic patellofemoral parameters in this population. Purpose: The primary purpose was to assess radiographic measures of coronal-plane alignment, longitudinal growth, patellar congruence, and trochlear dysplasia after MPFLR in a skeletally immature population. A secondary purpose was to assess this population compared with a matched cohort with a focus on trochlear dysplasia prevalence and the effect of MPFLR on patellar height. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 28 children with a minimum 1-year follow-up who underwent isolated MPFLR were identified. All patients were skeletally immature, defined as fully open physes on both sides of the knee joint, at the time of surgery. The development of a limb length discrepancy or angular growth abnormalities were assessed on standing hip-to-ankle radiographs, patellar tilt and congruence were measured on the Merchant view of the knee, and the grade of trochlear dysplasia and patellar height were assessed on lateral knee radiographs. A sex- and age-matched group of patients who underwent anterior cruciate ligament reconstruction was formed as a control for patellar height and trochlear dysplasia measurements. Results: The mean patient age was 11.71 ± 2.02 years at the time of surgery with a mean follow-up of 23.54 ± 12.49 months. All but 1 patient in the MPFLR group had preoperative features consistent with trochlear dysplasia. There was no significant difference in limb length or coronal-plane alignment at final follow-up (P = .725 and P > .999, respectively). Both the MPFLR and the anterior cruciate ligament reconstruction groups had a statistically significant decrease in the Caton-Deschamps index between the preoperative and postoperative time points (mean, 0.18 ± 0.20 and 0.11 ± 0.14, respectively; P = .161). Conclusion: MPFLR may be safely performed utilizing an epiphyseal femoral socket in a skeletally immature cohort without affecting normal longitudinal growth or coronal limb alignment. The previously reported effect of MPFLR in reducing patellar height may be related to physiological growth based on similar changes noted in a comparison cohort that did not undergo the procedure.

Does loop length change after anterior cruciate ligament reconstruction with adjustable loop cortical suspension device?: Observation of the hamstring graft completely filling the femoral tunnel

PurposeThe adjustable loop cortical suspension device (ALD) is a useful femoral fixation device in anterior cruciate ligament (ACL) reconstructions, but the possibility of loosening has been suggested. The purpose of this study was to evaluate the elongation of an adjustable loop and the position of the hamstring graft inside the femoral socket.MethodsThe subjects were 33 patients who underwent ACL reconstruction with a hamstring tendon. The graft was fixed using ALD and completely filled the femoral socket. Magnetic resonance images were taken one week and one year after the operation. The loop length, femoral socket length, and graft length inside the socket were measured and statistically compared with the clinical outcomes.ResultsThe loop length one week after surgery was 18.9 ± 4.4 mm, and 1 year after surgery was 19.9 ± 4.5 mm (P < 0.001). The gap between the top of the graft and femoral socket was 0.9 ± 1.8 mm one week after surgery and 1.3 ± 1.7 mm one year after surgery (P = 0.259). At one week post-operation, a gap was found in nine patients (27.3%). The loop length and gap did not strongly correlate with clinical findings.ConclusionACL reconstruction using ALD showed a gap between the graft and femoral socket at the one week post-operation mark in 27.3% of participants. One year after the surgery, there were cases where the gap increased and/or decreased, but the elongation of the loop was 1 mm on average. Our findings suggest that ALD is clinically safe to use; however, has the possibility of initial loop elongation and non-uniform changes.Level of evidenceIV.

Posterolateral Corner Reconstruction Using Double Femoral Fixation With Adjustable Loop Cortical Suspension and Interference Screw

Background: The posterolateral corner (PLC) of the knee is a complex anatomic region of the knee comprising the popliteus tendon, the popliteofibular ligament (PFL), and the fibular collateral ligament (FCL). Treatment of PLC injuries is based on the degree of varus and rotational instability on preoperative examination and is recommended in grade 3 injuries.1,6 Technique Description: The key concept of this new surgical technique is to use adjustable loop cortical suspensory fixation implants for initial femoral fixation of the popliteus and the FCL grafts. This allows for individual tensioning of the grafts prior to definitive fixation with an interference screw. An anatomic fibular tunnel is initially created, followed by popliteus and FCL anatomic femoral socket drilling. A TightRope RT implant is attached to the popliteus end of the graft and secured through a bone tunnel on the medial femoral cortex initially. The popliteus end of the graft is then pulled into the femoral socket before tunneling the graft through the fibular tunnel. A second TightRope RT implant is secured to the FCL end of the graft before securing it to the medial femoral cortex through a bone tunnel and pulling the graft into the drilled femoral socket. An interference screw is first used to secure the graft at the fibular tunnel. The knee is then taken to 60° where the TightRope device is used to remove residual creep and optimize final tensioning prior to final fixation with interference screw in femoral socket. With the knee at 30° of flexion, neutral rotation, and slight valgus, the same steps are repeated for FCL graft. A posterolateral capsular shift is completed for additional stability. Results: Residual posterolateral corner instability or failure after reconstruction surgery has been reported in 6% to 9.4% of surgical reconstruction case.2,3,5 The use of cortical suspensory devices in PLC reconstructions allows independent dialing of optimal graft tension for both the popliteus and FCL reconstruction before final interference screw fixation, therefore presumably limiting any residual creep and allowing for a double femoral fixation of the graft. Discussion: We describe a novel technique for posterolateral corner reconstruction which allows for optimal and individual tensioning of the structures of the posterolateral corner. Given the technique still uses well-described and validated graft choices and anatomic landmarks for reconstruction, we expect this new technique to allow for similar if not improved outcomes when compared with current gold standard.4

Contribution to the Microstructural Study of a Composite Material Based on Carbon Fibers for Use in Orthopedic Prostheses

The use of a carbon fiber composite material to make external prostheses in the form of a femoral socket was the subject of this laboratory study. According to the prior bibliographical studies, this material adapts well to this type of prosthesis. The objective of this research is to study its microscopic structure, in order to verify the good wetting of the fibers by the resin, the good cohesion and molding by infusion. The morphological study of the facies of the parallelepiped-shaped specimens was carried out after cuts perpendicular to the axis of the fiber strands, parallel according to the width and thickness of the specimen. This study was carried out using a scanning electron microscope (SEM), in order to determine, thanks to the typical microstructure of the composite, the various degradations, which appear as a result of the effect of static tension. The laminate used is based on three layers of carbon taffeta fabric and an orthocrylic resin. Tensile tests have been carried out at a speed of 1mm/min with a Zwick/Roell machine with a load cell of 50 kN. This speed was chosen to allow a comparative study with glass fiber specimens, which have been used previously for the production of prostheses, before those made of carbon. The microscopic study allowed to identify the four types of degradation; Matrix fracture, which manifested itself as fault lines, in preferred directions of different sizes. This contributed to interlaminar delamination. The decohesion that contributes to delamination in a different way from that of matrix breakage is visible at different levels. Interlaminar delamination results from the combined effect of matrix breakdown and decohesion and manifests itself as uneven strata. Fiber breakage was manifested by shearing. This study allowed to observing a degradation of the material imposed by static traction. As for the material used in orthopaedics, it has retained good cohesion and meets the requirements of prostheses, despite the defects detected by the microscopic study.

Poster 229: Improved Epiphyseal Socket Placement with Intraoperative 3D Fluoroscopy: Consecutive Series of Pediatric All-epiphyseal Anterior Cruciate Ligament Reconstruction.

Objectives:All-epiphyseal anterior cruciate ligament reconstruction (ACLR) is a safe procedure for skeletally immature patients with ACL tears because the sockets are contained within the epiphysis and do not cross the growth plate. However, due to the undulation of the distal femoral physis, accidental disturbance of the growth plate during tunnel placement is possible. It is imperative to obtain intraoperative imaging to view the trajectory of the guide wire prior to reaming the socket. The purpose of this study was to investigate the effect of the use of 3D intraoperative fluoroscopy on socket placement in patients undergoing all-epiphyseal ACLR. We hypothesized that 3D imaging would allow for better intraoperative visualization of the growth plate and a smaller incidence of growth plate violation.Methods:Patients under the age of 18 who underwent a primary ACLR between 2011 and 2018 by the senior authors were retrospectively reviewed. Patients that underwent an all-epiphyseal ACLR with an available postoperative MRI were included. Demographic data, surgical details and type of intraoperative fluoroscopy were collected. The minimal distances between the femoral socket and distal femoral physis (DFP) and tibial socket and proximal tibial physis (PTP) were recorded. Sockets that touched the physis or extended into the metaphysis were recorded as zero. Patients were split into two groups; a 2D imaging group that received intraoperative anterior to posterior and lateral fluoroscopic radiographs and a 3D fluoroscopy imaging group. Interrater reliability of radiographic measurements was evaluated using intraclass correlation coefficient (ICC). Statistical analysis was performed using a student’s t-test to determine differences between groups.Results:72 patients fit the inclusion criteria and were retrospectively reviewed. 54 patients had 2D imaging and 18 patients had 3D imaging. The mean age of the cohort at time of surgery was 12.3 ± 1.5 years, 79% of patients were male, and 54% tore their left ACL. The mean time from surgery to postoperative MRI was 2.0 ± 1.1 years. The ICC was 0.92 (95% CI 0.35-0.98), indicating almost perfect interrater reliability. The mean difference in distance between the tibial socket and the PTP was significantly less in the 2D imaging group than the 3D imaging group (1.2 ± 1.7mm vs 2.5 ± 2.2mm, p=0.03). (Table 1). The femoral socket touched or extended beyond the DFP significantly less in the 2D group than in the 3D group (13% vs 43%, p<0.000).Conclusions:There was a significantly decreased incidence of DFP violation with use of 3D intraoperative imaging for all-epiphyseal ACLR socket placement. Surgeons should consider utilizing 3D imaging to potentially decrease the rate of growth disturbance due to physis violation in these patients.

Paper 84: Differences in Metrics of Knee Joint Loading Between Individuals Following a Primary Anterior Cruciate Ligament Repair (ACL-R) Surgery Versus Those Who Underwent a Standard ACL Reconstruction with a Patella Bone-Tendon-Bone Autograft (ACLR)

Objectives:Recent research suggests that the short- and long-term outcomes following Anterior Cruciate Ligament Reconstructions (ACLR) on knee joint health are worse than originally thought. The ACLR procedure may result in or expediate the arthritic process through a variety of factors including prolonged underloading of the knee joint following surgery. These recent findings have resulted in a renewed interest in the ACL repair (ACL-r) procedure as a potentially more joint “friendly” secondary to less surgical trauma with the preservation of the native ACL ligament. In several animal models and in human clinical data, ACL remnant preservation and ACL entire ligament repair/preservation has been shown to benefit lower extremity and knee biomechanics, proprioception, and short term clinical outcomes. However, there is limited data on the newer ACL-r techniques and their subsequent outcomes on knee joint loading. Therefore, the purpose of this study was to assess for differences in metrics of knee joint loading between individuals following a primary anterior cruciate ligament repair (ACL-r) surgery versus those who underwent a standard ACL reconstruction with a patella bone-tendon-bone autograft (ACLR).Methods:A total of 30 participants were enrolled into this study [ACL-r n: 15, age(yrs): 38.8±13.9, Ht(cm): 173.4±10.0, Wt(kg): 77.9±17.5; ACLR: n: 15, age(yrs): 25.60±1.7, Ht(cm): 173.5±10.3, Wt(kg): 75.4±15.6]. Participants in ACL-r group all sustained a proximal ACL disruption (Sherman Classification Type 1 or 2) that was amenable to repair and underwent primary ACL repair with suture fixation. ACL-r was performed under arthroscopic visualization with 2 or 3 standard portals in a technique similar to that described by van der list, MD (2017), but modified by the senior author to include only one 4.75mm swivelock (Arthrex) secured in the anterior aspect of the native footprint on the medial wall of the lateral femoral condyle. Participants in the ACLR group all underwent a primary ACLR with patella bone-tendon-bone autograft. The autograft bone blocks were crimped to 9mm and then two 10mm femoral and tibial tunnels created for the graft. An independent tunnel technique, utilizing the medial portal for creation of the femoral socket within the native ACL femoral attachment site, was performed in all ACLR patients. At 12 weeks following surgery participants in both groups completed the IKDC questionnaire and biomechanical testing with two AMTI force plates and a 10 camera Qualisys motion capture system. Peak knee extension moment (Nm/Ht*Wt) and total knee joint power (Watt/Ht*Wt) as a measure of eccentric loading (contraction) during the descent phase of a single-leg squat were calculated on the surgical limb and averaged across the middle three trials. Participants also completed quadriceps strength testing on both limbs (surgical and non-surgical) on an isokinetic dynamometer at 60 °/sec. The average peak torque of five repetitions were used to calculate a limb symmetry index (LSI) [Surgical/NonSurgical X100]. Independent t-tests were used to assess for differences between groups in three metrics. For descriptive purposes a separate independent t-test was used to assess for differences in age, height, mass, and IKDC scores. Statistical significance was set at P< 0.05 for all analyses.Results:There were no differences in height (p=0.996), mass(p=.678), or IKDC ( p=0.886) scores between the groups; however, there was a significant difference in age (p=0.009). The ACL-r had a significantly greater peak knee extension moment (ACL-r: -0.078±0.02; ACLR: -0.059±.02; p=0.014) and total knee joint power (ACL-r-0.03±0.01; ACLR: -0.02±0.01, p=0.016) than the ACLR group. The ACL-r also had a significantly great quadriceps LSI than the ACLR group (ACL-r: 65.09±20.4, ACLR: 49.2±11.4, p=0.014).Conclusions:The results of this study indicate that those individuals following ACL-r demonstrate increased knee joint loading during a single leg squat task compared to those who underwent ACLR. Decreases in knee extension moment have been reported across a variety of tasks and across a variety of time points following ACLR. Furthermore, decreased knee extension moments have been associated with movement profiles that have been linked to cartilage degeneration following ACLR. The improved knee extension moment in the ACL-r group at this early time may indicate a positive change in joint loading and potentially a decreased rate of cartilage degeneration. Knee joint total power accounts for both knee moment and angular velocity, indicating improved knee loading throughout the entire eccentric movement in the ACL-r group and further supports the notion of improved knee joint loading following ACL-r compared to ACLR. Decreased quadriceps muscle strength has been associated with changes in cartilage structure and it has been suggested that maximizing muscle strength in the first 6 months following surgery may promote improved cartilage healing, thus the increased quadriceps LSI in the ACL-r may be protective early in the recovery process.

ACL reconstruction with femoral and tibial adjustable versus fixed-loop suspensory fixation: a retrospective cohort study

BackgroundCortical suspensory fixation (CSF) devices gain more and more popularity as a reliable alternative to interference screws for graft fixation in anterior cruciate ligament (ACL) reconstruction. Adjustable-loop fixation may be associated with increased anterior laxity and inferior clinical outcome. The purpose of the study was to compare anterior laxity and clinical outcome after minimally invasive all-inside ACL reconstruction using an adjustable-loop (AL) to a standard technique with a fixed-loop (FL) CSF device.MethodsPatients who underwent primary single-bundle ACL reconstruction with a quadrupled hamstring autograft at a single institution between 2012 and 2016 were reviewed. In the AL group minimally invasive popliteal tendon harvesting was performed with an all-inside approach (femoral and tibial sockets). In the FL group a traditional anteromedial approach was used for tendon harvesting and a femoral socket and full tibial tunnel were drilled. An objective clinical assessment was performed with Telos x-rays and the International Knee Documentation Committee (IKDC) Objective Score. Patient-reported outcomes (PRO) included the IKDC Subjective Score, the Lysholm Knee Score, the Knee Injury and Osteoarthritis Score (KOOS) and the Tegner Activity Scale.ResultsA total of 67 patients were enrolled in this retrospective study with a mean follow-up of 4 (± 1.5) years. The groups were homogenous at baseline regarding age, gender, and the time to surgery. At follow-up, no statistically significant differences were found regarding anterior laxity (AL: 2.3 ± 3 mm vs. FL: 2.3 ± 2.6 mm, p = 0.981). PRO scores were comparable between the AL and FL groups (IKDC score, 84.8 vs. 88.8, p = 0.185; Lysholm 87.3 vs. 89.9, p = 0.380; KOOS 90.7 vs. 91.4, p = 0.720; Tegner 5.5 vs. 6.2, p = 0.085). The rate of saphenous nerve lesions was significantly lower in the AL group with popliteal harvesting of the tendon (8.3% vs. 35.5%, p = 0.014).ConclusionThe use of an adjustable-loop device on the femoral and tibial side led to similar stability and clinical results compared to a fixed-loop device.

Improved epiphyseal socket placement with intraoperative 3D fluoroscopy: a consecutive series of pediatric all-epiphyseal anterior cruciate ligament reconstruction.

Disturbance of the growth plate during all-epiphyseal anterior cruciate ligament reconstruction (ACLR) socket placement is possible due to the undulation of the distal femoral physis and proximal tibial physis. Therefore, it is important to obtain intraoperative imaging of the guide wire prior to reaming the socket. The purpose of this study was to investigate the effect of the use of 3D intraoperative fluoroscopy on socket placement in patients undergoing all-epiphyseal ACLR. It was hypothesized that 3D imaging would allow for more accurate intraoperative visualization of the growth plate and hence a lower incidence of growth plate violation compared to 2D imaging. Patients under the age of 18 who underwent a primary all-epiphyseal ACL reconstruction by the senior authors and had an available postoperative MRI were retrospectively reviewed. Demographic data, surgical details, and the distances between the femoral socket and distal femoral physis (DFP) and tibial socket and proximal tibial physis (PTP) were recorded. Patients were split into two groups based on type of intraoperative fluoroscopy used: a 2D group and a 3D group. Interrater reliability of radiographic measurements was evaluated using intraclass correlation coefficient (ICC). Seventy-two patients fit the inclusion criteria and were retrospectively reviewed. 54 patients had 2D imaging and 18 patients had 3D imaging. The mean age at time of surgery was 12.3 ± 1.5years, 79% of patients were male, and 54% tore their left ACL. The mean time from surgery to postoperative MRI was 2.0 ± 1.1years. The ICC was 0.92 (95% CI 0.35-0.98), indicating almost perfect interrater reliability. The mean difference in distance between the tibial socket and the PTP was significantly less in the 2D imaging group than the 3D imaging group (1.2 ± 1.7mm vs 2.5 ± 2.2mm, p = 0.03). The femoral and tibial sockets touched or extended beyond the DFP or PTP, respectively, significantly less in the 3D group than in the 2D group (11% vs 43%, p < 0.000, 17% vs 65%, p < 0.000). There was a significantly increased distance from the PTP and decreased incidence of DFP violation with use of 3D intraoperative imaging for all-epiphyseal ACLR socket placement. Surgeons should consider utilizing 3D imaging prior to creating femoral and tibial sockets to potentially decrease the risk of physis violation in these patients. III.

Tribological performances of a novel biopolymeric material HD-HA for hip joint implants

For most modern hip joint implants, metal-on-plastic pairs are preferred over metal-on-metal ones, where cobalt (Co)–chromium (Cr) alloy and ultrahigh-molecular-weight polyethylene (UHMWPE) are commonly used as the femoral head and socket, respectively. In such implants, the durability of the UHMWPE component is not up to the mark due to severe wear. This study presents better tribological performance of a novel biopolymeric material coded as HD-HA prepared from high-density polyethylene (HDPE) and hydroxyapatite. In the first part, wear tests showed specific wear rates of 4.85 × 10−6and 5.27 × 10−6(mm3/N)/m for HDPE and UHMWPE, respectively, whereas the specific wear rate was 3.19 × 10−6(mm3/N)/m for HD-HA. Comparison revealed that HD-HA had a 60–65% lower wear rate than the others. Similarly, in the second part, the friction coefficient is found to be 0.23 and 0.11 for UHMWPE and HDPE, respectively, and 0.06 for HD-HA, which shows a 20–50% decrease in frictional values. Atomic force microscopy images revealed that the rough peaks were 296, 486 and 1100 nm for HD-HA, HDPE and UHMWPE, respectively, whereas the scanning electron microscopy images showed fewer loose particles around the worn HD-HA surface. This shows that HD-HA has a smoother surface, and based on the overall tribological performance, it should be preferred for the acetabular component of hip joint implants.

Anterior Cruciate Ligament Femoral Socket Preparation Using a Cannulated, Calibrated Drill With Adjustable Stop and Slotted Cannula

Anteromedial portal–guided femoral tunnel preparation during anterior cruciate ligament reconstruction can be difficult owing to poor visualization. This may cause iatrogenic damage to the medial femoral condyle cartilage and the posterior cruciate ligament fibers or overdrilling through the lateral femoral cortex, creating difficulties in the use of femoral suspensory devices during anterior cruciate ligament reconstruction. We describe an accurate and safe technique for femoral graft socket preparation using a cannulated, calibrated drill with an adjustable stop and slotted cannula. This easy and reproducible technique uses simple additional instruments and effectively addresses concerns related to femoral graft socket preparation, without requiring additional surgical time.

Rule 50: A Reproducible Technique to Minimize Graft-tunnel Mismatch During ACL Reconstruction Using Bone-Tendon-Bone (BTB) Graft

Introduction: The use of bone-tendon-bone grafts are a popular option for anterior cruciate ligament (ACL) reconstruction. Graft-tunnel mismatch is a technical pitfall of using this type of graft. Objective: The primary objective of this study was to provide results of a simple technique to minimize graft-tunnel-mismatch that we call “Rule 50.” Rule 50 is a technique of estimating the length of the femoral socket (20 mm) with the length of the native ACL (30 mm) and using this to alter the length of the tibial tunnel using a calibrated drill guide. Materials and Methods: Prospectively, 103 consecutive ACL reconstructions (68 autograft, 35 allograft) were analyzed. Any excess graft was cut flush with the distal tibial cortex and measured to evaluate how much graft was implanted and how much was removed. Results: At least 20 mm of tibial-sided bone plug from the grafts were implanted 100% of the time (regardless of patient height or total graft length) with an average of 30.63 to 31 mm of tibial bone plug implanted. This accounted for 86% to 92% of the harvested tibial bone plugs, respectively, implanted. Aperture fixation was accomplished in 100% of the cases. Conclusion: Rule 50 is a reproducible method to maximize the amount of bone from a bone-tendon-bone graft within the tibial tunnel to minimize graft-tunnel mismatch and can provide a minimum of 20 mm of distal bone 100% of the time.