Comparison of the Syndesmotic Staple to the Transsyndesmotic Screw: A Biomechanical Study

2005 ◽  
Vol 26 (3) ◽  
pp. 224-230 ◽  
Author(s):  
Timothy Marqueen ◽  
John Owen ◽  
Gregg Nicandri ◽  
Jennifer Wayne ◽  
James Carr
Keyword(s):  
External Rotation ◽  
Biomechanical Study ◽  
Tibial Rotation ◽  
Intact State ◽  
Cortical Screw ◽  
Torsional Testing ◽  
Load To Failure ◽  
Posterior Translation ◽  
Fresh Frozen ◽  
Torsional Loads

Background: Controversy still exists about treatment of syndesmotic injuries. This study compared the fixation strengths and biomechanical characteristics of two types of ankle fracture syndesmotic fixation devices: the barbed, round staple and the 4.5-mm cortical screw. Methods: Cadaveric testing was done on 21 fresh-frozen knee disarticulation specimens in biaxial servohydraulic Instron testing equipment. Submaximal torsional loads were applied to specimens in intact and Weber C bimalleolar fracture states. The specimens were then fixed with one of two techniques and again subjected to submaximal torsion and torsion to failure. Biomechanical parameters measured included tibiofibular translation and rotation, maximal torque to failure, and degrees of rotation at failure. Results: Compared to the intact state before testing, the staple held the fibula in a more anatomic position than the screw for mediolateral and anterior displacements (p < 0.01). With submaximal torsional testing, the staple restored 85% of the tibiofibular external rotation and all of the posterior translation values as compared to the intact state. The screw resulted in 203% more tibiofibular medial translation and 115% more external rotation than the intact state. The degree of tibial rotation during submaximal torsional loading was restored to within 15% of intact values but was 21% less with the screw. There was no statistical difference between the screw and staple when tested in load to failure. Tibio-talar rotation at failure was statistically different with the staple construct, allowing more rotation as compared to the screw. Conclusion: The staple restored a more physiologic position of the fibula compared to the syndesmotic screw. Both provided similar performance for the load to failure testing, while the screw reduced tibial rotation more after cyclic loading. There was more tibial rotation before failure for the staple, suggesting a more elastic construct. This study provides biomechanical data to support the clinical use of the syndesmotic staple.

scholarly journals Restoration of Tibiofibular Kinematics with a Tricortical Screw or Suture Button Fixation After Syndesmotic Ankle Injuries

2017 ◽  
Vol 2 (3) ◽  
pp. 2473011417S0000
Author(s):  
Conor Murphy ◽  
Thomas Pfeiffer ◽  
Jason Zlotnicki ◽  
Volker Musahl ◽  
Richard Debski ◽  
...  
Keyword(s):  
Screw Fixation ◽  
External Rotation ◽  
Tracking System ◽  
Optical Tracking ◽  
Ankle Injuries ◽  
Suture Button ◽  
Tibiofibular Ligament ◽  
Cortical Screw ◽  
Significant Difference ◽  
Posterior Translation

Category: Ankle, Sports, Trauma Introduction/Purpose: Anterior inferior tibiofibular ligament (AITFL), Posterior inferior tibiofibular ligament (PITFL) and Interosseous membrane (IOM) disruption is a predictive measure of residual symptoms after ankle injury. In unstable injuries, the syndesmosis is treated operatively with cortical screw fixation or a suture button apparatus. Biomechanical analyses of suture button versus cortical screw fixation methods show contradicting results regarding suture button integrity and maintenance of fixation. The objective of this study is to quantify tibiofibular joint motion in syndesmotic screw and suture button fixation models compared to the intact ankle. Methods: Five fresh-frozen human cadaveric specimens (mean age 58 yrs.; range 38-73 yrs.) were tested using a 6-degree-of- freedom robotic testing system. The tibia and calcaneus were rigidly fixed to the robotic manipulator and the subtalar joint was fused. The full fibular length was maintained and fibular motion was unconstrained. Fibular motion with respect to the tibia was tracked by a 3D optical tracking system. A 5 Nm external rotation moment and 5 Nm inversion moment were applied to the ankle at 0°, 15°, and 30° plantarflexion and 10° dorsiflexion. Outcome variables included fibular medial-lateral (ML) translation, anterior-posterior (AP) translation, and external rotation (ER) in the following states: 1) intact ankle, 2) AITFL transected, 3) PITFL and IOM transected, 4) 3.5 mm cannulated tricortical screw fixation, 5) suture button fixation. An ANOVA with a post-hoc Tukey analysis was performed for statistical analysis (*p<0.05). Results: Significant differences in fibular motion were only during the inversion moment. Fibular posterior translation was significantly higher with complete syndesmosis injury compared to the intact ankle at 0°, 15°, and 30° plantarflexion and the tricortical screw at 15° and 30°. Significantly higher fibular posterior translation was observed with the suture button compared to the intact ankle at 15° and 30 plantarflexion and to the tricortical screw at 15°. ER was significantly increased with complete injury compared to the tricortical screw at 0° and 30° plantarflexion. The suture button demonstrated significantly greater ER at 0° plantarflexion and 10° dorsiflexion compared to the intact ankle. The only significant difference in ML translation exists between the tricortical screw and complete injury at 30° plantarflexion. Conclusion: The suture button did not restore physiologic motion of the syndesmosis. It only restored fibular ML translation. Significant differences in AP translation and ER persisted compared to the intact ankle. The tricortical screw restored fibular motion in all planes. No significant differences were observed compared to the intact ankle. These findings are consistent with previous studies. This study utilized a novel setup to measure unconstrained motion in a full length, intact fibula. Physicians should evaluate AP translation and ER as critical fibular motions when reconstructing the syndesmosis with suture button fixation.

scholarly journals Scapholunate Ligament Internal Brace 360 Tenodesis (SLITT) Procedure: A Biomechanical Study

2018 ◽  
Vol 08 (03) ◽  
pp. 250-254
Author(s):  
Sanjeev Kakar ◽  
Ryan M. Greene ◽  
Janet Denbeigh ◽  
Andre Van Wijnen
Keyword(s):  
Surgical Techniques ◽  
Maximum Load ◽  
Difficult Problem ◽  
Biomechanical Study ◽  
Mode Of Failure ◽  
Load To Failure ◽  
Internal Brace ◽  
Fresh Frozen ◽  
Prolonged Immobilization ◽  
Ligament Disruption

Background Twelve paired fresh frozen cadaveric wrists were randomized to a 360-degree tenodesis repair group or the 360-degree tenodesis repair with an internal brace (suture tape) construct. Case Description The specimens were preloaded to 5 N and subsequently biomechanically loaded to failure, at a rate of 0.1 mm/s on a jig that allowed for axial load. The maximum load and mode of failure were recorded. Load to failure in the 360 tenodesis group with internal brace was 283.47 ± 100.25 N, compared with the 360 tenodesis group only, whose yield strength was 143.61 ± 90.54 N. The mode of failure within the internal brace construct was either through knot slippage, graft disruption, or bone separation from strength testing construct. The 360 tenodesis group tended to fail via graft slippage or graft rupture. Literature Review The management of scapholunate instability can be a difficult problem to treat. Traditionally, many of the surgical reconstructions have focused upon dorsal ligament reconstruction with Kirschner (K) wire fixation. This results in prolonged immobilization of the wrist with varied outcomes, in part due to the multiaxial instability that may persist due to concomitant volar ligament disruption. To address this instability, surgical techniques have been devised that address both the volar and dorsal ligament injuries. Clinical Relevance Scapholunate reconstruction with a 360-degree tenodesis and internal brace augmentation (SLITT procedure) provided superior biomechanical stability than tenodesis alone.

Plantar and Calcaneocuboid Joint Pressure after Isolated Medial Column Fusion versus Medial and Lateral Column Fusion: A Biomechanical Study

2011 ◽  
Vol 32 (11) ◽  
pp. 1069-1074 ◽  
Author(s):  
Joshua P. Nadaud ◽  
Brent G. Parks ◽  
Lew C. Schon
Keyword(s):  
Biomechanical Study ◽  
Intact Group ◽  
Lateral Column ◽  
Intact State ◽  
Calcaneocuboid Joint ◽  
Position Data ◽  
Fresh Frozen ◽  
Gait Phase ◽  
And Inversion ◽  
Column Group

Background: We compared forefoot and calcaneocuboid pressure in isolated medial column fusion (1-3 tarsometatarsal fusion) versus medial and lateral column fusion (1-5 tarsometatarsal fusion) in a neutral, inversion, and eversion loading model in stance gait phase. Methods: Twelve fresh-frozen cadaveric specimens were cyclically loaded to 720 N at 0.5 Hz for 30 cycles. Plantar and calcaneocuboid joint pressures were measured in neutral, inversion, and eversion in the intact foot, with isolated medial column fusion, and with medial and lateral column fusion. Results: Lateral pressure was higher in the medial and lateral column fusion group than isolated medial column fusion and intact in neutral (55.8 ± 14.8 versus 46.2 ± 13.6 and 45.5 ± 14.8 kPa, respectively) and eversion (80.7 ± 18.4 versus 61.8 ± 13.7 and 60.2 ± 18.2 kPa, respectively) ( p ≤ 0.001). Calcaneocuboid pressure was higher in medial and lateral column fusion than isolated medial column fusion and intact in neutral (1436.7 ± 210.6 versus 1073.7 ± 282.5 and 1084.9 ± 337.6, respectively; p = 0.001) and inversion (1518.3 ± 270.5 versus 1310.5 ± 298.8 and 1237.1 ± 401.9, respectively; p = 0.02). Using combined position data, calcaneocuboid pressure was significantly higher in the medial and lateral column group than in both other groups. The isolated medial column fusion group did not differ significantly from the intact group in any measurement. Conclusion: Medial and lateral column fusion significantly increased lateral and calcaneocuboid pressures with loading compared with isolated medial column fusion and the intact state. No difference was observed between isolated medial column fusion and the intact state. Clinical Relevance: It may be advisable to avoid fusing the lateral column in tarsometatarsal arthrodesis if possible to avoid pressure increase in the forefoot and hindfoot.

Biomechanical evaluation of an intramedullary clavicle screw in simple oblique and butterfly wedge fractures

2021 ◽  
pp. 095441192110310
Author(s):  
Bryce F Kunkle ◽  
John D DesJardins ◽  
Joel R Campbell ◽  
Josef K Eichinger ◽  
Michael J Kissenberth ◽  
...  
Keyword(s):  
Statistical Significance ◽  
Bending Moment ◽  
Biomechanical Properties ◽  
Fracture Pattern ◽  
Biomechanical Study ◽  
Torsional Stiffness ◽  
Oblique Fracture ◽  
Torsional Testing ◽  
Fresh Frozen ◽  
Wedge Fracture

This biomechanical study evaluates the performance of a solid titanium-alloy intra-medullary ( IM) clavicular screw in torsion and cantilever bending in cadaveric clavicle specimens with simulated simple oblique and butterfly wedge midshaft fractures. Thirty-two fresh-frozen male clavicles were sorted into six experimental groups: Torsion Control, Torsion Simple Oblique Fracture, Torsion Butterfly Wedge Fracture, Bending Control, Bending Simple Oblique Fracture, and Bending Butterfly Wedge Fracture. The experimental groups were controlled for density, length, diameter, and laterality. All other samples were osteotomy-induced and implanted with a single 90 mm × 3 mm clavicle screw. All groups were tested to physiologically relevant cutoff points in torsion or bending. There were no statistically significant differences in the performance of the oblique and butterfly wedge fracture models for any torsion or bend testing measures, including maximum torsional resistance ( p = 0.66), torsional stiffness ( p = 0.51), maximum bending moment ( p = 0.43), or bending stiffness ( p = 0.73). Torsional testing of samples in the direction of thread tightening tended to be stronger than samples tested in loosening, with all groups either approaching or achieving statistical significance. There were no significant differences between the simple oblique or the butterfly-wedge fracture groups for any of the tested parameters, suggesting that there is no difference in the gross biomechanical properties of the bone-implant construct when the IM clavicle screw is used in either a simple midshaft fracture pattern or a more complex butterfly wedge fracture pattern.

Screw Fixation Compared to H-Locking Plate Fixation for First Metatarsocuneiform Arthrodesis: A Biomechanical Study

2005 ◽  
Vol 26 (11) ◽  
pp. 984-989 ◽  
Author(s):  
David A. Cohen ◽  
Brent G. Parks ◽  
Lew C. Schon
Keyword(s):  
Locking Plate ◽  
Mechanical Design ◽  
Screw Fixation ◽  
Plate Fixation ◽  
Biomechanical Study ◽  
Maximal Load ◽  
Load To Failure ◽  
Fresh Frozen ◽  
The Mean ◽  
Eden Prairie

Background: Several different techniques have been used for fixation of first metatarsocuneiform (MTC) joint arthrodesis, a standard treatment for arthritis, instability, and deformity of the MTC joint. Improved plating systems using locking designs are now available, but no studies have yet compared this construct with other methods. We compared load to failure with a locking plate design versus standard crossed-screw fixation. Methods: Ten matched pairs of fresh frozen cadaver feet were used. The bone density of each pair was measured with DEXA scanning. One foot of each pair was randomly assigned to have a dorsomedial Normed H titanium locking plate (Normed Medizin-Technik Vertriebs-GmbH, D-78501 Tuttlingen, Germany) applied to the first MTC joint. On the other foot of the pair, fixation of the first MTC joint was done with crossed ACE DePuy 4.0 (DePuy/Ace, Warsaw, IN) titanium cannulated screws. The first metatarsal and first cuneiform were then isolated and planted in an epoxy resin. The specimens were loaded to failure in a four-point bending configuration using a MTS Mini Bionix test frame (MTS Systems Corp., Eden Prairie, MN). Failure was defined as displacement of more than 3 mm at the arthrodesis site. The Student t-test was used to determine any observed differences, with significance set at p ≤ 0.05. Results: The mean maximal load to failure was 140.08 N (SD ± 77.1) for screw fixation alone and 58.09 N (SD ± 11.86) for the H-locking plate. This difference was statistically significant ( p = 0.008). The mean stiffness of the construct for screw fixation alone was 83.10 N/mm (SD ± 49.8) and 19.96 N/mm for the H-locking plate. This difference also was statistically significant ( p = 0. 004). Conclusion: Screw fixation for first MTC arthrodesis created a stronger and stiffer construct than did the H-locking plate. This was likely due to the mechanical design of the implants. Compression across the MTC joint could be applied with the screws, but the plate relied on a fixed angle design with no compression.

Comparison of 2 Surgical Techniques of Posterolateral Corner Reconstruction of the Knee

2005 ◽  
Vol 33 (12) ◽  
pp. 1838-1845 ◽  
Author(s):  
Thomas Nau ◽  
Yan Chevalier ◽  
Nicola Hagemeister ◽  
Jacques A. deGuise ◽  
Nicolas Duval
Keyword(s):  
Degrees Of Freedom ◽  
Dynamic Testing ◽  
External Rotation ◽  
Surgical Techniques ◽  
Posterolateral Corner ◽  
Popliteus Tendon ◽  
Tibial Rotation ◽  
Intact State ◽  
Posterolateral Structures ◽  
Internal Tibial Rotation

Background Various surgical techniques to treat posterolateral knee instability have been described. To date, the recommended treatment is an anatomical form of reconstruction, in which the 3 key structures of the posterolateral corner are addressed: the lateral collateral ligament, the popliteofibular ligament, and the popliteus tendon. Hypothesis Two methods of surgical reconstruction will restore posterolateral knee instability, in terms of static laxity as well as dynamic 6 degrees of freedom kinematics, to statistically significant levels compared with the intact state. Study Design Controlled laboratory study. Methods Two surgical techniques (A and B) were used to reconstruct the posterolateral structures in 10 cadaveric knees. Static tests were performed on the intact, sectioned, and reconstructed knees at 30° and 90° of flexion for anterior-posterior laxity and external rotational laxity, as well as at 0° and 30° of flexion for varus laxity; dynamic 6 degrees of freedom kinematic testing, through a path of motion from 90° of flexion to full extension, was also performed. Results For the static varus tests, external rotation and varus laxity were significantly increased after the posterolateral structures were cut. Both reconstruction techniques restored external rotation and varus laxity to levels not significantly different from the intact state. For technique B, dynamic testing did not show any significant difference for all degrees of freedom kinematics compared with the intact state. However, for technique A, a significant internal tibial rotation was observed throughout the entire path of motion from 0° to 90° of knee flexion. Conclusions Both surgical techniques for anatomical posterolateral corner reconstruction showed good results in the static laxity tests. The anatomical reconstruction of all structures, including the popliteus tendon, resulted in an abnormal internal tibial rotation during dynamic testing.

scholarly journals The effect of posterior compression of the facet joints for initial stability and sagittal profile in the treatment of thoracolumbar fractures: a biomechanical study

2021 ◽  
Author(s):  
Michael Ruf ◽  
Tobias Pitzen ◽  
Ivo Nennstiel ◽  
David Volkheimer ◽  
Jörg Drumm ◽  
...  
Keyword(s):  
Axial Rotation ◽  
Biomechanical Study ◽  
Sagittal Profile ◽  
Posterior Fixation ◽  
Neutral Position ◽  
Intact State ◽  
Custom Made ◽  
Flexion Extension ◽  
Fresh Frozen ◽  
Anterior Support

Abstract Purpose Surgical treatment of thoracolumbar A3-fractures usually comprises posterior fixation—in neutral position or distraction—potentially followed by subsequent anterior support. We hypothesized that additional posterior compression in circumferential stabilization may increase stability by locking the facets, and better restore the sagittal profile. Methods Burst fractures Type A3 were created in six fresh frozen cadaver spine segments (T12–L2). Testing was performed in a custom-made spinal loading simulator. Loads were applied as pure bending moments of ± 3.75 Nm in all six movement axes. We checked range of motion, neutral zone and Cobb’s angle over the injured/treated segment within the following conditions: Intact, fractured, instrumented in neutral alignment, instrumented in distraction, with cage left in posterior distraction, with cage with posterior compression. Results We found that both types of instrumentation with cage stabilized the segment compared to the fractured state in all motion planes. For flexion/extension and lateral bending, flexibility was decreased even compared to the intact state, however, not in axial rotation, being the most critical movement axis. Additional posterior compression in the presence of a cage significantly decreased flexibility in axial rotation, thus achieving stability comparable to the intact state even in this movement axis. In addition, posterior compression with cage significantly increased lordosis compared to the distracted state. Conclusion Among different surgical modifications tested, circumferential fixation with final posterior compression as the last step resulted in superior stability and improved sagittal alignment. Thus, posterior compression as the last step is recommended in these pathologies.

scholarly journals Posterior Translation of the Fibula is a Critical Factor in the Stability of the Syndesmosis After Injury and Repair

2018 ◽  
Vol 6 (7_suppl4) ◽  
pp. 2325967118S0012
Author(s):  
Neel Patel ◽  
Thomas Rudolf Pfeiffer ◽  
Jan-Hendrik Naendrup ◽  
Conor Murphy ◽  
Jason Zlotnicki ◽  
...  
Keyword(s):  
Sagittal Plane ◽  
Screw Fixation ◽  
External Rotation ◽  
Tracking System ◽  
Optical Tracking ◽  
Ankle Injuries ◽  
Suture Button ◽  
Tibiofibular Ligament ◽  
Cortical Screw ◽  
Posterior Translation

Objectives: Anterior inferior tibiofibular ligament (AITFL), posterior inferior tibiofibular ligament (PITFL), and interosseous membrane (IOM) disruption is a predictive measure of residual symptoms after an ankle injury. Unstable syndesmotic injuries are typically treated surgically with cortical screw or suture button fixation. Previous studies have shown contradicting findings regarding the effects of partial syndesmotic injuries and different surgical fixation methods on tibiofibular kinematics. Thus, the objective of this study was to quantify tibiofibular joint motion with sequential disruption of the syndesmosis and with syndesmotic screw and suture button fixation compared to the intact ankle. Methods: Nine fresh-frozen human cadaveric specimens (mean age 60 yrs.; range 38-73 yrs.) were tested using a six degree-of-freedom robotic testing system. The subtalar joint was fused and the tibia and calcaneus were rigidly fixed to a robotic manipulator, while complete fibular length was maintained and fibular motion was unconstrained. A 5 Nm external rotation moment and 5 Nm inversion moment were independently applied to the ankle at 0°, 15°, and 30° plantarflexion and 10° dorsiflexion. Fibular motion with respect to the tibia was tracked by a 3D optical tracking system. Outcome variables included fibular medial-lateral (ML) translation, anterior-posterior (AP) translation, and external rotation (ER) in the following states: 1) intact ankle, 2) AITFL transected, 3) AITFL, PITFL, and IOM transected (complete injury), 4) 3.5 mm cannulated tricortical screw fixation, 5) suture button fixation. An ANOVA with a post-hoc Tukey analysis was performed for statistical analysis (*p < 0.05). Results: All significant differences in fibular motion between ankle states occurred during the inversion moment. An isolated AITFL injury caused significant increases in fibular posterior translation at 15° and 30° plantarflexion compared to the intact ankle. A complete syndesmotic injury caused significant increases in fibular posterior translation in all 4 ankle positions and in fibular ER at 0° flexion and 15° plantarflexion compared to the intact ankle. No significant differences were detected in fibular motion between an isolated AITFL injury and complete injury at any ankle positions. No significant differences existed between the tricortical screw fixation and the intact ankle. Significantly higher fibular posterior translation was observed with the suture button compared to the intact ankle at 0° flexion, 30° and 15° plantarflexion. (Figure 1) Conclusion: An isolated AITFL injury resulted in a significant increase in fibular posterior translation relative to the tibia, comparable to that a complete injury, especially in positions of plantarflexion. Current diagnostic protocols after injury focus on the evaluation of fibular ML translation. However, these findings show that it is important to also evaluate syndesmotic stability in the sagittal plane and at different ankle positions. Restoration of native tibiofibular kinematics is essential to prevent post-traumatic arthritis. Tricortical screw fixation was able to restore tibiofibular kinematics in all planes. However, suture button fixation was not able to restore tibiofibular AP translation, which suggests that physicians should critically evaluate fibular AP translation and individualize treatment of unstable ankle injuries when reconstructing the syndesmosis with suture button fixation. [Figure: see text]

scholarly journals Influence of peracetic acid-ethanol sterilisation on the biomechanical properties of human meniscus transplants

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Volker Eras ◽  
Josefine Graffunder ◽  
Norus Ahmed ◽  
Jan C. Brune
Keyword(s):  
Peracetic Acid ◽  
Biomechanical Properties ◽  
Bone Block ◽  
Test Device ◽  
Level Of Evidence ◽  
Load To Failure ◽  
Graft Extrusion ◽  
Fresh Frozen ◽  
Failure Loads ◽  
N Loading

Abstract Purpose Meniscus allograft transplantation (MAT) is a possible treatment for patients suffering with pain after meniscectomy. Here, peracetic acid (PAA) sterilised meniscus transplants were investigated on whether they would provide an adequate alternative to fresh-frozen transplants in their viscoelastic and mechanical properties. Methods In this analysis, 31 menisci donors (26 male and 5 female) were included. The average donor age was 49.87 years, ranging from 32 to 65 years. Menisci of matched pairs of knees underwent chemical sterilisation while counterparts were left fresh-frozen. Stiffness and load to failure were determined via suture retention. Further menisci were analysed while attached to the tibial bone block using a novel test device to mimic physiological load distribution. Meniscus relaxation, stiffness and failure loads were determined. Histology and biphasic properties of the menisci were examined and results were analysed using paired t-tests. Results A novel custom built test device allowed the application of physiological loads for suture retention testing and revealed no significant differences between PAA sterilised (14.85 ± 4.46 N/mm, 50.49 ± 17.01 N) and fresh-frozen (18.26 ± 4.46 N/mm, 59.49 ± 21.07 N) regarding stiffness and failure load, respectively. Furthermore, initial 200 N loading showed significantly higher strain in sterilised menisci (18.87 ± 1.56) compared to fresh frozen (13.81 ± 1.04). Load relaxation experiments demonstrated significantly lower relaxation for sterilised menisci (77.71 ± 1.62) compared to fresh-frozen (89.11 ± 1.00, p-value < 0.0001). Conclusion Peracetic acid sterilised human menisci performed equally to fresh-frozen counterparts in a suture retention test and in physiological failure testing providing an adequate alternative. However, meniscus relaxation, biphasic properties and strain were shown to be significantly different between the groups. A common problem of MAT is graft extrusion or shrinkage, therefore the parameters measured here should be considered and may influence meniscus extrusion after transplantation. Level of evidence n/a (experimental study)

scholarly journals Interference Screw Versus Suture Anchors for Femoral Fixation in Medial Patellofemoral Ligament Reconstruction: A Biomechanical Study

2021 ◽  
Vol 9 (3) ◽  
pp. 232596712198928
Author(s):  
Heath P. Gould ◽  
Nicholas R. Delaney ◽  
Brent G. Parks ◽  
Roshan T. Melvani ◽  
Richard Y. Hinton
Keyword(s):  
Medial Patellofemoral Ligament ◽  
Interference Screw ◽  
Biomechanical Study ◽  
Graft Fixation ◽  
Mpfl Reconstruction ◽  
Suture Anchors ◽  
Femoral Fixation ◽  
Significant Difference ◽  
Load To Failure ◽  
The Mean

Background: Femoral-sided graft fixation in medial patellofemoral ligament (MPFL) reconstruction is commonly performed using an interference screw (IS). However, the IS method is associated with several clinical disadvantages that may be ameliorated by the use of suture anchors (SAs) for femoral fixation. Purpose: To compare the load to failure and stiffness of SAs versus an IS for the femoral fixation of a semitendinosus autograft in MPFL reconstruction. Study Design: Controlled laboratory study. Methods: Based on a priori power analysis, a total of 6 matched pairs of cadaveric knees were included. Specimens in each pair were randomly assigned to receive either SA or IS fixation. After an appropriate reconstruction procedure, the looped end of the MPFL graft was pulled laterally at a rate of 6 mm/s until construct failure. The best-fit slope of the load-displacement curve was then used to calculate the stiffness (N/mm) in a post hoc fashion. A paired t test was used to compare the mean load to failure and the mean stiffness between groups. Results: No significant difference in load to failure was observed between the IS and the SA fixation groups (294.0 ± 61.1 vs 250.0 ± 55.9; P = .352), although the mean stiffness was significantly higher in IS specimens (34.5 ± 9.6 vs 14.7 ± 1.2; P = .004). All IS reconstructions failed by graft pullout from the femoral tunnel, whereas 5 of the 6 SA reconstructions failed by anchor pullout. Conclusion: In this biomechanical study using a cadaveric model of MPFL reconstruction, SA femoral fixation was not significantly different from IS fixation in terms of load to failure. The mean load-to-failure values for both reconstruction techniques were greater than the literature-reported values for the native MPFL. Clinical Relevance: These results suggest that SAs are a biomechanically viable alternative for femoral-sided graft fixation in MPFL reconstruction.

Sign in / Sign up

Export Citation Format

Share Document