Femoral Socket Research Articles

Femoral Tunnel Fixation for Medial Patellofemoral Ligament Reconstruction in the Growing Patient

Medial patellofemoral ligament (MPFL) reconstruction has been shown to be a successful treatment for patients with recurrent patellar instability. The purpose of this study is to compare radiographic parameters prior to and following an MPFL reconstruction with femoral tunnel fixation in the skeletally immature patient to investigate potential effects on the physic and future growth. Skeletally immature patients undergoing isolated MPFL reconstruction were retrospectively reviewed. Fixation of proximal MPFL was performed as a femoral socket using Schottle’s point with the entry approximately 5 mm distal to the physis. Patients with open growth plates and 1-year post-operative standing alignments were included. Radiographic measures of patellar tilt, patellar height, patellar subluxation, and trochlear dysplasia were compared pre-operatively and post-operatively on the operative limb. Pre- and post-operative coronal alignment and limb length measurements were compared between the operative and non-operative limbs. Nineteen skeletally immature patients with an average age of 11.6 years (range 5-15 years old) underwent isolated MPFL reconstruction. The average follow-up time was 24 months. No significant differences were found between the change in femur (0.49 mm, p=0.526) or total limb length (1.08 mm, p=0.241) when comparing the operative to the non-operative limb, with an average of 47 mm of growth in the operative limb seen during the time period. There was no significant difference in the change in LDFA between operative and non-operative limb as well as symmetric changes noted in the mechanical axis. The change in patellar tilt on the operative limb was found to be significant (12.78°, p=0.030), and the change in patellar height by Caton-Deschamps approached significance (0.08mm, p= 0.077). No significant difference was found with trochlear dysplasia measures. The present study suggests MPFL reconstruction with femoral tunnel fixation is safe and does not result in growth disturbance in skeletally immature patients.

Tailor-made design, fabrication and validation of SrO doped nanostructured ZTA ceramic Femoral head – Acetabular socket liner assembly

An established commercial grade SrO doped ZTA composition has been considered to design, fabrication through uniaxial pressing followed by sintering and polishing, validation of dimension, 3D surface profile, 3D microstructure, and compressive load bearing capacity of femoral head – acetabular socket liner prototypes for the hip prosthesis. While design and dimensions are concerned, both the steel (HRC60) molds were designed and machined to achieve precious dimensions of femoral head (FH; OD – 30 ± 0.01 mm) and acetabular socket liner (ASL; ID – 30.15 ± 0.01 mm). A close variation in the range of ±0.01 mm was confirmed the precision geometry of polished FH and ASL with consideration of 22 points coordinate measuring method (CMM). 3D surface profile ensures the surface characteristics of Ra = 0.2 ± 0.01 μm and Rq = 0.5 ± 0.01 μm for outer surface of FH and an inner surface of ASL, respectively. Structure integrity and fabrication defects including cracks and pores free bulk structures were confirmed by Micro CT. The compressive load resistance known as burst strength for independent FH and FH-ASL assembly were measured 16.2 KN and 17.6 KN, respectively. The developed ceramic prototypes have an economic advantage and can be adopted as artificial hip prosthesis after extensive in-vitro and in-vivo analysis.

Remnant-Preserving Posterior Cruciate Ligament Reconstruction Over Remnant Fibers Using a Figure-of-Four Position and a Posterior Trans-Septal Portal.

Anatomic tunnel formation and remnant preservation are the recent trends in posterior cruciate ligament (PCL) reconstruction. However, it is difficult to observe the anatomical PCL footprint and perform the operation in the process of remnant‐preserving PCL reconstruction. This study describes a single‐bundle, transtibial PCL reconstruction technique with anatomic graft passage over the remnant PCL fibers. A femoral tunnel of PCL is created at 2 mm medial to the roof of the intercondylar notch and 3 mm proximal to the margin of the articular cartilage. The tibial insertion of PCL is observed using a figure‐of‐four position through a posterior trans‐septal portal. A tibial bone tunnel is made below the distal center portion of the tibial insertion of residual PCL fibers. The graft is passed over the PCL through the tibial bone tunnel, the space between the anterior cruciate ligament (ACL) and the residual PCL fibers, to the femoral socket and is fixed by the EndoButton and screw. This technique is able to ensure a reasonable intra‐articular length and optimal isometry. It has been applied in patients with PCL rupture and posterior instability of the knee joint, and no intraoperative or postoperative complications occurred. Our technology provides a valuable new treatment option for PCL rupture. Future comparative studies are needed to further clarify its beneficial effect.

Development and Assessment of Novel Multiligament Knee Injury Reconstruction Graft Constructs and Techniques.

Multiligament knee injury (MLKI) typically requires surgical reconstruction to achieve the optimal outcomes for patients. Revision and failure rates after surgical reconstruction for MLKI can be as high as 40%, suggesting the need for improvements in graft constructs and implantation techniques. This study assessed novel graft constructs and surgical implantation and fixation techniques for anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), posterior medial corner (PMC), and posterior lateral corner (PLC) reconstruction. Study objectives were (1) to describe each construct and technique in detail, and (2) to optimize MLKI reconstruction surgical techniques using these constructs so as to consistently implant grafts in correct anatomical locations while preserving bone stock and minimizing overlap. Cadaveric knees (n = 3) were instrumented to perform arthroscopic-assisted and open surgical creation of sockets and tunnels for all components of MLKI reconstruction using our novel techniques. Sockets and tunnels with potential for overlap were identified and assessed to measure the minimum distances between them using gross, computed tomographic, and finite element analysis-based measurements. Percentage of bone volume spared for each knee was also calculated. Femoral PLC-lateral collateral ligament and femoral PMC sockets, as well as tibial PCL and tibial PMC posterior oblique ligament sockets, were at high risk for overlap. Femoral ACL and femoral PLC lateral collateral ligament sockets and tibial popliteal tendon and tibial posterior oblique ligament sockets were at moderate risk for overlap. However, with careful planning based on awareness of at-risk MLKI graft combinations in conjunction with protection of the socket/tunnel and trajectory adjustment using fluoroscopic guidance, the novel constructs and techniques allow for consistent surgical reconstruction of all major ligaments in MLKIs such that socket and tunnel overlap can be consistently avoided. As such, the potential advantages of the constructs, including improved graft-to-bone integration, capabilities for sequential tensioning of the graft, and bone sparing effects, can be implemented.

Femoral Tunnel Fixation for Medial Patellofemoral Ligament Reconstruction in the Growing Patient is Safe for Future Growth

Objectives:Medial patellofemoral ligament (MPFL) reconstruction has been shown to be a successful treatment for patients with recurrent patellar instability and is increasingly used to treat skeletally immature patients. The purpose of this study is to compare radiographic parameters prior to and following an MPFL reconstruction with femoral tunnel fixation in the skeletally immature patient to investigate potential effects on the physis and future growth.Methods:Skeletally immature patients undergoing isolated MPFL reconstruction were retrospectively reviewed. Fixation of proximal MPFL was performed as a femoral socket using Schottle’s point with the entry approximately 5 mm distal to the physis. Patients with open growth plates and 1-year postoperative standing alignments were included. Radiographic measures of patellar tilt, patellar height, patellar subluxation, and trochlear dysplasia were compared pre-operatively and post-operatively on the operative limb. Pre- and post-operative coronal alignment and limb length measurements were compared between the operative and non-operative limbs.Results:Nineteen skeletally immature patients with an average age of 11.6 years (range 5-15 years old) underwent isolated MPFL reconstruction. The average follow-up time was 24 months. No significant differences were found between the change in femur (0.49 mm, p=0.526) or total limb length (1.08 mm, p=0.241) when comparing the operative to the non-operative limb, with an average of 47 mm of growth in the operative limb seen during the time period. There was no significant difference in the change in LDFA between operative and non-operative limb as well as symmetric changes noted in the mechanical axis. The change in patellar tilt on the operative limb was found to be significant (12.78°, p=0.030), and the change in patellar height by Caton-Deschamps approached significance (0.08mm, p= 0.077). No significant difference was found with trochlear dysplasia measures.Conclusion:The present study suggests MPFL reconstruction with femoral tunnel fixation is safe and does not result in growth disturbance in skeletally immature patients.Table 1.Mean Tegner Activity Score based on type of posterolateral tibial plateau impaction fractures. N Tegner Score STD No fracture1986.02.1Type I995.52.1Type IIA515.41.9Type IIB204.71.6Type IIIA114.52.5Type IIB214.91.9STD-Standard deviation

FEMORAL TUNNEL FIXATION FOR MEDIAL PATELLOFEMORAL LIGAMENT RECONSTRUCTION IN THE GROWING PATIENT IS SAFE FOR FUTURE GROWTH

Background:Medial patellofemoral ligament (MPFL) reconstruction has been shown to be a successful treatment for patients with recurrent patellar instability and is increasingly used to treat skeletally immature patients.Purpose:The purpose of this study is to compare radiographic parameters prior to and following an MPFL reconstruction with femoral tunnel fixation in the skeletally immature patient to investigate potential effects on the physis and future growth.Methods:Skeletally immature patients undergoing isolated MPFL reconstruction were retrospectively reviewed. Fixation of proximal MPFL was performed as a femoral socket using Schottle’s point with the entry approximately 5 mm distal to the physis (Figure 1). Patients with open growth plates and 1-year post-operative standing alignments were included. Radiographic measures of patellar tilt, patellar height, patellar subluxation, and trochlear dysplasia were compared pre-operatively and post-operatively on the operative limb. Pre- and post-operative coronal alignment and limb length measurements were compared between the operative and non-operative limbs.Results:Nineteen skeletally immature patients with an average age of 11.6 years (range 5-15) underwent isolated MPFL reconstruction. The average follow-up time was 24 months. No significant differences were found between the change in femur (0.49 mm, p=0.526) or total limb length (1.08 mm, p=0.241) when comparing the operative to the non-operative limb, with an average of 47 mm of growth in the operative limb seen during the time period. There was no significant difference in the change in LDFA between operative and non-operative limb as well as symmetric changes noted in the mechanical axis. The change in patellar tilt on the operative limb was found to be significant (12.78°, p=0.030), and the change in patellar height by Caton-Deschamps approached significance (0.08mm, p= 0.077). No significant difference was found with trochlear dysplasia measures.Conclusion:The present study suggests MPFL reconstruction with femoral tunnel fixation is safe and does not result in growth disturbance in skeletally immature patients.Figure 1.Fluoroscopic images of the femoral placement of the bone tunnel for the medial patellofemoral ligament reconstruction in a 13 year old male utilizing Schottle point and remaining distal to the physis. (A) Lateral view of the knee (B) Notch view of the knee in order to confirm position of the guide pin distal to the physis posteriorly.

Does Bone Plug and Graft Orientation (Inferior Versus Posterior) Alter Native Femoral Footprint Coverage in Bone Patellar Tendon Bone Anterior Cruciate Ligament Reconstruction?

The purpose of this study was to compare the percentage of native femoral anterior cruciate ligament (ACL) footprint covered by the 2 most clinically relevant bone plug/graft orientations used with interference screw fixation in ACL reconstruction. A secondary purpose was to assess whether a transtibial or tibia-independent drilling technique would affect this outcome. Five matched pairs of cadaver knees were used. Each matched pair had 1 knee assigned to a 10-mm femoral socket prepared via a transtibial (TT) drilling technique and the other via an anteromedial (AM) drilling technique. The bone plug of each graft was press-fitted into the femoral socket with the graft collagen in 2 distinct clinically relevant orientations (collagen inferior or posterior). The digitized graft collagen cross-sectional area(CSA) in each orientation was overlaid onto the native femoral ACL footprint CSA to generate a percentage of native ACL footprint covered by graft collagen. The average native ACL femoral footprint CSA was 110.5 ± 9.1 mm2, with no difference between knees assigned to TT or AM drilling (112.6 ± 2.7 vs 108.4 ± 13.0 mm2, P=.49). The average femoral socket CSA was 95.4 ± 8.7 mm2, with no difference between TT and AM tunnels (95.5 ± 9.9 vs 95.3 ± 8.4 mm2, P= .96). There was no difference between the percentage of native footprint covered between TT and AM sockets (76.8% ± 7.8% vs 82.2% ± 13.7%, P= .47). Irrespective of drilling technique, there was significantly greater native ACL footprint covered by graft collagen when the bone plug was oriented with graft collagen inferior rather than posterior (75.6% ± 6.3% vs 65.4% ± 11.4%, P= .02). Orienting the femoral bone plug such that the graft collagen is inferior rather than posterior significantly increases native ACL femoral footprint coverage in bone-patellar tendon-bone ACL reconstruction. This effect is consistent across AM and TT drilling techniques. Surgeons attempting to restore an anatomic ACL footprint should consider bone plug-graft orientation when performing ACL reconstruction. Controlled laboratory study.

Medial Patellofemoral Ligament Reconstruction in Skeletally Immature Patients.

Patellofemoral instability is a common problem affecting children and adolescents, with recurrent instability often requiring surgical intervention. Medial patellofemoral ligament (MPFL) reconstruction has become a mainstay for the treatment of patellofemoral instability because of the biomechanical importance of the MPFL against lateral dislocation as well as the high frequency of MPFL injury following traumatic patellar dislocation. The concern in managing skeletally immature patients is the potential for injury to the distal femoral physis. Here, we highlight 2 techniques for MPFL reconstruction. The first technique utilizes a hamstring autograft. The steps include: Step 1: Harvest the semitendinosus graft from a 2-cm posteromedial incision with use of an open tendon harvester proximally and a closed tendon harvester distally. Step 2: Prepare the graft for double-bundle reconstruction, allowing for approximately 50 to 60 mm for the reconstructed MPFL and 15 to 20 mm for graft placement within the patella and femoral sockets. Step 3: Use a guidewire and reamer to create 2 patellar sockets approximately 15 mm long each. Step 4: Use a guidewire under fluoroscopy to position and create a femoral socket distal to the distal femoral physis approximately 15 mm long. Step 5: Fix the graft on the femur with use of a tenodesis screw, pass the graft through the soft-tissue space between the fascia and synovium to the superior half of the patella, then dock the free ends of the graft onto the 2 patellar sockets with "PEEK (polyetheretherketone) SwiveLocks (Arthrex)" while the knee is in 30° of flexion. We also review a second technique of docking the hamstring graft onto the adductor tubercle and suturing it proximally to the deep distal medial aspect of the quadriceps tendon. Although only a limited number of studies have reported the outcomes of MPFL reconstruction in skeletally immature patients, such studies have demonstrated a high return to preoperative level of sports activity and a reduced prevalence of recurrent patellar instability.

Anatomic Posterolateral Corner Reconstruction With Autogenous Peroneus Longus Y Graft Construct

The posterolateral corner of the knee is composed of the fibular collateral ligament, popliteus tendon, and popliteofibular ligament, which provide varus and rotational stability to the knee. An anatomic technique reconstructs these structures through 2 femoral sockets and 1 tibial and 1 fibular tunnel. This reconstruction can be performed using a peroneus longus autograft that is prepared as a Y construct. The peroneus longus autograft is preferred because it provides adequate length and diameter for the entire reconstruction. Initially, the doubled loop of the Y is passed into the tibial tunnel and fixed with an adjustable cortical button. The shorter limb of the Y is used for reconstruction of the popliteus tendon. The longer limb of the Y is passed from posterior to anterior through the fibular tunnel and is fixed in the tunnel with an interference screw to re-create the popliteofibular ligament. The remaining graft is then shuttled deep to the iliotibial band and superficial to the popliteus tendon, into the femoral socket, to re-create the fibular collateral ligament.

A Percutaneous Technique to Reposition the Cortical Button of Adjustable-Loop Devices in Anterior Cruciate Ligament Reconstruction

Adjustable-loop devices are relatively new but quite popular and have been routinely used for around a decade in arthroscopic anterior cruciate ligament reconstruction for hamstring graft fixation on the femur. They allow surgeons to adapt to different tunnel lengths, eliminate the need for multiple loop sizes, decrease the “bungee cord effect,” maximize the amount of graft within the femoral socket available for incorporation, and allow retensioning of the graft. Apart from these advantages, certain complications are associated with the use of adjustable-loop devices. When the cortical button is being pulled up through the femoral tunnel, it may be pulled up with greater force, causing it to come out of the vastus lateralis, the iliotibial band, or even the skin. When the graft is pulled back from the tibial side, the cortical button may flip in the substance of the vastus lateralis or outside the iliotibial band. This soft-tissue interposition can cause ischemic necrosis of the interposed tissue, soft-tissue irritation, migration of the cortical button, or early loosening of the graft, leading to anterior cruciate ligament reconstruction failure. We describe a percutaneous solution to this common intraoperative technical complication. The outer sheath of a 4.5-mm arthroscope, 4.5-mm acromionizer, or notchplasty burr can be safely used to put the cortical button back against the lateral cortex of the femur.

Combined Anatomic Anterior Cruciate and Anterolateral Ligament Reconstruction With Quadriceps Tendon Autograft and Gracilis Allograft Through a Single Femoral Tunnel

Despite technical advances in anterior cruciate ligament (ACL) reconstruction surgery, there remains a need to improve postoperative outcomes with respect to graft failure rates. Recently, it has been shown that combined ACL–anterolateral ligament (ALL) reconstruction (using a graft composed of a tripled semitendinosus and single-strand gracilis tendon) is associated with a significant reduction in graft rupture rates compared with isolated ACL reconstruction. It is recognized that the hamstring tendons are not always available (revision scenario) or are not always the primary ACL graft choice. Some surgeons prefer to use quadriceps tendon ACL grafts because of the suggestion that these grafts may be associated with equal or better functional scores. However, if surgeons wish to try to reduce the risk of graft failure by performing an ALL reconstruction, either a combined reconstruction or the use of an independent ALL graft, with a separate femoral socket, could be considered. The disadvantage of an independently performed extra-articular procedure is the risk of femoral socket collision with the femoral ACL tunnel. This Technical Note therefore describes the use of a combined ACL-ALL reconstruction using quadriceps tendon autograft (ACL graft), gracilis allograft (ALL graft), and a single femoral tunnel.

Positioning the femoral bone socket and the tibial bone tunnel using a rectangular retro-dilator in anterior cruciate ligament reconstruction.

PurposeThe purpose of this study was to evaluate the positions of femoral bone sockets and tibial bone tunnels made with the rectangular retro-dilator (RRD), which we manufactured for anterior cruciate ligament reconstruction (ACLR) with a bone-patella tendon-bone (BPTB) graft which is fixed into the rectangular bone socket and tunnel made at anatomical ACL insertion sites.Methods42 patients who had undergone ACLR with BPTB using the RRD were evaluated to assess bone socket and tunnel positions by the quadrant method and Magnussen classification using three-dimensional (3-D) CT. Intra-operative complications were also investigated in all patients.Results3-D CT of the operated knee joints using the RRD showed that the bone socket and tunnel were placed in anatomical positions. In the quadrant method, the mean position of the femoral bone socket aperture was located at 22.0 ± 4.2% along the Blumensaat’s line, and 37.4 ± 7.2% across the posterior condylar rim. The mean positions of the tibial bone tunnel aperture were 37.7 ± 5.2% and 46.1 ± 2.2% antero-posteriorly and medio-laterally, respectively. In addition, according to the Magnussen classification, 39 cases were evaluated as type 1, and almost all were located behind the lateral intercondylar ridge (also known as the resident’s ridge). 3 cases were classified as type 2, which overlapped with the resident’s ridge. A partial fracture of BPTB bone fragment was observed in 2 patients, but no serious complications including neurovascular injury were observed.ConclusionThe study indicates that the use of RRD achieves a safe anatomical reconstruction of the ACL.

Medial patellofemoral ligament (MPFL) reconstruction technique using an epiphyseal femoral socket with fluoroscopic guidance helps avoid physeal injury in skeletally immature patients.

The purpose of this study was to assess the physeal safety associated with the use of an epiphyseal femoral socket for paediatric medial patellofemoral ligament (MPFL) reconstruction. Fifty-four knees in 49 skeletally immature patients underwent physeal-sparing MPFL reconstruction performed by 1 surgeon at a tertiary care academic medical centre from 2007 to 2016. A femoral socket distal to the femoral physis was used for graft fixation in all the patients. To assess physeal safety, all included patients either had post-operative MRIs of the operative knee or standing hip-to-ankle radiographs. Physeal safety was assessed on MRI, and the distance between the femoral socket relative to the physis was measured at both the aperture and the end of the socket. Development of lower limb angular deformities and/or limb length discrepancy (LLD) was evaluated using post-operative standing hip-to-ankle radiographs, patient records, and clinical assessments. The mean age at time of surgery was 13.3 ± 1.6years. The median length of radiographic follow-up was 2.2years (range 1.0-5.7years). At most recent clinical follow-up, five patients (9.3%) had recurrent patellar instability, with three patients (5.6%) undergoing subsequent tibial tubercle osteotomy or revision MPFL reconstruction. There was no statistically significant difference in leg length between operated and non-operated extremities (n.s.). There was no statistically significant difference between non-operated and operated mMPTA (n.s.) and mLDFA (n.s.) measurements. On post-operative MRI, there was no evidence of physeal arrest. The median distance from the physis to the socket at the aperture and distal end of the femoral socket were 5.9mm (range 1.9-12) and 7.1mm (1.3-12.4), respectively. These results demonstrate that with fluoroscopic guidance, placing the femoral socket distal to the distal femoral physis is an effective method for avoiding physeal injury and subsequent growth disturbances in children with patellar instability. Clinically, this information is essential in optimal surgical management of these patients, as this technique allows for femoral fixation of the MPFL reconstruction graft within the epiphysis while also preserving normal growth. Level IV-case series.

Anterior Cruciate Ligament Reconstruction With Hamstring Autograft: A Matched Cohort Comparison of the All-Inside and Complete Tibial Tunnel Techniques.

Background:Surgical reconstruction of the anterior cruciate ligament (ACL) is one of the most common orthopaedic procedures, with an estimated 100,000 to 175,000 procedures performed annually. Recently, the all-inside reconstruction technique has come into favor and is theorized to be superior to the complete tibial tunnel technique.Purpose:To compare clinical and patient-reported outcomes (PROs) for hamstring autograft ACL reconstruction (ACLR) performed with an all-inside versus a complete tibial tunnel technique.Study Design:Cohort study; Level of evidence, 3.Methods:Patients who underwent hamstring autograft ACLR via either an all-inside approach (femoral and tibial sockets) or a complete tibial tunnel approach (femoral socket and full-length, transtibial tunnel) at a single institution between July 2011 and July 2015 were reviewed. Demographic information, preoperative comorbidities, surgical details, physical examination findings, and follow-up outcomes were extracted from the medical record. Physical examination data included pivot-shift, Lachman, and range of motion examinations, whereas PROs included the Tegner activity scale, Lysholm score, and International Knee Documentation Committee (IKDC) score at a minimum of 2 years after surgery. Return to sport and risk factors for failure were analyzed.Results:A total of 82 patients (mean ± SD age, 25.8 ± 10.2 years) who underwent all-inside reconstruction (median PRO follow-up, 30.1 months; range, 24.7-72.9 months) and 54 patients (mean ± SD age, 21.1 ± 7.3 years) who underwent complete tibial tunnel reconstruction (median PRO follow-up, 25.8 months; range, 23.9-74.5 months) met the inclusion criteria. PRO scores at latest follow-up were comparable between the all-inside versus the complete tibial tunnel groups (Lysholm score, 93.8 vs 94.4, P = .621; IKDC score, 93.5 vs 93.3, P = .497; Tegner activity score, 6.4 vs 6.8, P = .048). Complications (including graft failure) were experienced by 20% of patients in the all-inside group compared with 24% in the complete tibial tunnel group (P = .530). Graft failure before the final follow-up was experienced by 10% of patients in the all-inside group compared with 19% in the complete tibial tunnel group (P = .200). Mean return to sport was 12.5 months in the all-inside group versus 9.9 months in the complete tibial tunnel group (P = .028).Conclusion:All-inside and complete tibial tunnel hamstring autograft ACLR resulted in excellent physical examination findings and PROs at minimum 2-year follow-up. Both techniques successfully restored knee stability and patient function.

An In Vivo Prediction of Anisometry and Strain in Anterior Cruciate Ligament Reconstruction – A Combined Magnetic Resonance and Dual Fluoroscopic Imaging Analysis

To evaluate the invivo anisometry and strain of theoretical anterior cruciate ligament (ACL) grafts in the healthy knee using various socket locations on both the femur and tibia. Eighteen healthy knees were imaged using magnetic resonance imaging and dual fluoroscopic imaging techniques during a step-up and sit-to-stand motion. The anisometry of the medial aspect of the lateral femoral condyle was mapped using 144 theoretical socket positions connected to an anteromedial, central, and posterolateral attachment site on the tibia. The 3-dimensional wrapping paths of each theoretical graft were measured. Comparisons were made between the anatomic, over the top (OTT), and most-isometric (isometric) femoral socket locations, as well as between tibial insertions. The area of least anisometry was found in the proximal-distal direction just posterior to the intercondylar notch. The most isometric attachment site was found midway on the Blumensaat line with approximately 2% and 6% strain during the step-up and sit-to-stand motion, respectively. Posterior femoral attachments resulted in decreased graft lengths with increasing flexion angles, whereas anterodistal attachments yielded increased lengths with increasing flexion angles. The anisometry of the anatomic, OTT and isometric grafts varied between tibial insertions (P < .001). The anatomic graft was significantly more anisometric than the OTT and isometric graft at deeper flexion angles (P < .001). An area of least anisometry was found in the proximal-distal direction just posterior to the intercondylar notch. ACL reconstruction at the isometric and OTT location resulted in nonanatomic graft behavior, which could overconstrain the knee at deeper flexion angles. Tibial location significantly affected graft strains for the anatomic, OTT, and isometric socket location. CLINICALRELEVANCE: This study improves the knowledge on ACL anisometry and strain and helps surgeons to better understand the consequences of socket positioning during intra-articular ACL reconstruction.

All-Inside Anterior Cruciate Ligament Reconstruction-A Systematic Review of Techniques, Outcomes, and Complications.

The all-inside technique (AIT) for anterior cruciate ligament reconstruction (ACLR) is gaining popularity as a more anatomic, less invasive, technique with the potential for more rapid recovery. This systematic review aims to critically assess components of the technique, its safety profile, outcomes, and complications. PUBMED, EMBASE, and MEDLINE were searched for studies discussing primary ACLR using the AIT. Article screening, quality assessment, and data abstraction were completed in duplicate, and a minimal clinically important difference (MCID) was used to frame the descriptive results in a clinically significant context. A total of 13 studies satisfied the inclusion criteria. Five-hundred twenty six patients (mean age 31.9 ± 5.9 years) underwent ACLR using the AIT. The mean follow-up was 18.2 ± 7.7 months. Graft choice included autograft (73.8%) and allograft (26.2%). Drilling techniques for femoral sockets were outside-in (53.4%) and through the anteromedial portal (35.4%), whereas tibial sockets were drilled outside-in (35.0%) and through the superomedial portal (3.8%). The rehabilitation protocol had an immediate focus on obtaining full knee extension, jogging permitted 2 to 4 months postoperatively in 61.5% of studies, and return to cutting and pivoting sports 6 to 9 months postoperatively in 69.2% of studies. A MCID was reached for subjective International Knee Documentation Committee scores at 6, 12, and 24 months follow-up and Lysholm knee score at 24 months follow-up. An improvement in outcomes was most notably between 6 and 12 months postoperatively. There was a total of 31 complications (5.89%) and included graft rerupture (2.47%), loss of extension of 1° to 10° (1.14%), and cartilage or meniscus injuries on the operated knee (0.760%). Complications related to the surgical technique were not reported. The AIT for ACLR shows potential as a minimally invasive approach given the low graft failure rates and short-term improvements in knee function and stability, pain and patient important outcomes from this approach. Comparative studies with large sample sizes and a long-term follow-up are required to assess the proposed advantages of this technique. This is a Level IV study.

The drill wobble effect: oversizing the femoral tunnel during ACL reconstruction

ABSTRACTObjectives: In ACL reconstruction, autologous tendon graft can be attached to the femur, within a boney tunnel, using an Endobutton device. The ultimate aim being to achieve biological fixation and incorporation into the bone. Accurate bone tunnel diameter to match the tendon graft is vital to biologic incorporation and strength. The common technique of in sequence passing a guide wire, a cannulated 4.5 mm Endobutton drill, then a cannulated femoral socket drill causes the guidewire to lose cortical fixation and stability before the femoral socket drill is passed.The Objective of this study is to analyze this common technique of femoral socket creation and determine if it results in unintentionally oversizing the femoral socket due to femoral socket drill-wobble over a destabilised guide wire.Methods: 12 cadaveric femoral pairs equally divided between two groups underwent femoral socket creation in one of the two following sequences.Group 1: Guidewire, 4.5 mm endobutton drill, 8 mm femoral socket drill. Group 2: Guidewire, 8 mm femoral socket drill, 4.5 mm endobutton drill. The created femoral tunnels apertures and calibres were measured and then compared for accuracy between the two groups.Results: Passing the 4.5 mm drill before the 8 mm socket drill results in oversized tunnel apertures and calibres when compared to passing an 8 mm socket drill after the 4.5 mm drill has been passed (p<0.0001).Conclusion: To most precisely create an 8 mm femoral socket in ACL reconstruction, the 8 mm femoral socket reamer followed by the 4.5 mm should be passed over the guide wire to prevent guide wire destabilization and drill-wobble.

Treatment of patellofemoral instability in adolescent by anatomical double-bundle medial patellofemoral ligament reconstruction with double suture anchor technique

To explore the clinical outcomes of anatomical double-bundle medial patellofemoral ligament (MPFL) reconstruction with double suture anchor technique in treating patellofemoral instability in adolescent. Methods: Twenty-five young people with patellofemoral instability (25 knees) in our department from January 2013 to December 2014 were enrolled for this study. All patients were performed anatomical double-bundle MPFL reconstruction with arthroscopic-assisted suture anchors technique in the patella, and fixed in the femoral socket with absorbable interference screw. All patients are evaluated by different methods, including patient's satisfaction, patellar apprehension test, recurrent subluxation/dislocation, CT assessment of bone tunnel and patellar tilt angle. Lysholm scores, Tegner scores and Kujala scores were recorded at the final follow-up. Results: The mean follow-up was 24 (range 20-40) months. All cases were observed in negative patellar apprehension test. Infection, recurrent subluxation/dislocation and patellar fracture were not found at the last follow-up. CT results demonstrated that the tunnel position were good. The patellar tilt angle was decreased from 21.6°±2.3° to 10.5°±1.6° (P<0.05); the Lysholm scores was increased from 51.7±5.3 to 93.8±6.5 (P<0.05). Tegner scores was increased from 4.1±1.1 to 5.5±0.6 (P<0.05). Kujala scores was increased from 53.5±6.4 to 94.6±4.3 (P<0.05). Conclusion: Arthroscopic-assisted anatomical double-bundle MPFL reconstruction with the suture anchors technique is a safe, minimal invasive and effective surgical option for treating patellofemoral instability in adolescent.

Posterior Cruciate Ligament Reconstruction with Retrograde Femoral Technique, Posterior Trans-septal Portal and Full Tibial Tunnel

Suspensory femoral graft fixation has been a popular and reliable method in anterior cruciate ligament (ACL) reconstruction. Some authors have introduced suspensory femoral fixation in posterior cruciate ligament (PCL) reconstruction using inside-out (IO) technique. The use of IO technique for femoral tunnel preparation could significantly sharpen the critical corner, which might result in graft failure. A retrograde drilling pin that recently has been popular in ACL reconstruction allows “no incision” in the outside-in (OI) technique for the creation of a femoral socket. Here we describe the suspensory femoral fixation using a retro-socket technique in single-bundle PCL reconstruction. By using this technique, it is possible to create a retrograde femoral socket for suspensory femoral fixation in an OI manner in a desirable direction and reduce angulation of the graft in the entry area of the femoral tunnel.

Sequential MRI Study of Graft Integrity and Signal Following Pediatric All-epiphyseal ACL Reconstruction: Does the “Sharp Turn” at the Socket of the Distal Femoral Aperture Matter?

Objectives:To analyze graft structure and signal with particular emphasis on the distal femoral socket aperture following all-epiphyseal ACLR using hamstring autografts with sequential MRI in skeletally immature athletes.Methods:Retrospective cohort study of 23 skeletally immature patients who underwent ACLR by the same surgical team at a tertiary center during 2011-2013. Athletes had at least two follow-up MRIs, the first MRI 6-12 months after surgery and the second MRI >18 months, were included. Exclusion criteria included those athletes with inMRI follow-up (6) or with a failure of their reconstructions (1). All athletes were treated with an arthroscopic all-inside, all-epiphyseal ACLR, using hamstring autograft, secured with adjustable loop cortical buttons on both tibia and femur. MRI images were analyzed independently and blinded by an orthopaedic surgery fellow and a musculoskeletal radiology fellow. Using a GE Functional Analysis Software, the signal intensity (SI) of the graft was measured in 5 different locations: 1) femoral tunnel, 2) intra-articular proximal turn, 3) midsubstance, 4) intra-articular distal turn, and 5) tibial tunnel. Values were normalized to cortical bone density. The amount of perigraft scarring and synovitis was analyzed. An intraclass correlation coefficient was used to quantify inter-rater reliability, non-parametric Wilcoxon test for perigraft scarring and synovitis, one-way ANOVA to test if significant differences of SI were seen between the different graft locations, and a 2-tailed student t-test for SI changes from 1st to 2nd MRI.Results:The study included 16 patients (5 girls and 11 boys), with an average age at surgery of 11.9 years (range 10-15). The first follow-up MRI was on average at 8.4 months (range 6-12 months), while the 2nd MRI was on average 30.7 months (range 18-40) after surgery. Intra-class correlation coefficients were above 0.7 for all measurements, indicating an excellent concordance between observers. Perigraft scarring tended to reduce with follow-up (p=0.057) though not significantly, while synovitis had a significant reduction over time (p=0.01). On average, normalized SI showed no significant differences between measurements taken in different regions of the graft (p=0.58). When comparing the graft SI from 1st to 2nd MRI, no significant differences were found in any of the locations: femoral tunnel (p=0.14), proximal turn (p=0.11), midsubstance (p=0,29), intra-articular distal (p=0.10), or tibial tunnel (p=0.15). All 16 athletes returned to their prior sport at the same level of performance without re-injury.Conclusion:ACL grafts in skeletally immature patients with all-epiphyseal reconstructions maintain a stable intensity signaling at long term MRI follow-up, with no significant signal reduction over time. Despite the sharp turn created at the distal femoral socket aperture in physeal-sparing reconstructions, no particular anatomic location of the graft presents significantly different signal intensity over others. This is the first sequential mri study in pediatric epiphyseal acl reconstructions demonstrating postoperative maintenance of graft integrity and graft signal.