419 results found
Halewood C, Athwal KK, Amis AA, 2018, Pre-clinical assessment of total knee replacement anterior-posterior constraint, JOURNAL OF BIOMECHANICS, Vol: 73, Pages: 153-160, ISSN: 0021-9290
Heilpern G, Stephen J, Ball S, et al., 2018, It is safe and effective to use all inside meniscal repair devices for posteromedial meniscal 'ramp' lesions., Knee Surg Sports Traumatol Arthrosc
PURPOSE: Recently, it has been recognized that meniscocapsular ('ramp') lesions of the posterior one-third of the medial meniscus frequently occur during injuries causing ACL rupture, and that these lesions are easily missed at arthroscopy. Furthermore, it is clear that these lesions are biomechanically significant, adding to the deficits caused by ACL rupture, and that their repair can reverse this. The efficacy of an all inside repair technique has been questioned by some authors and by those who advocate a suture shuttle technique via an accessory posteromedial portal. The use of Ultra FastFix and FastFix 360 meniscal repair devices to repair posteromedial meniscocapsular separations was investigated in terms of safe deployment and the effectiveness. Author: Affiliations: Journal instruction requires a country for affiliations; however, these are missing in affiliations [1, 2]. Please verify if the provided country is correct and amend if necessary. METHODS: Twenty cadaveric fresh frozen knees were used-ten in each of two groups. A ramp lesion was created using a Beaver knife. The lesion was then repaired with either 4 Ultra FastFix (Smith and Nephew) or 4 FastFix 360 (Smith and Nephew) meniscal repair devices. The knees were put through a standardized loading cycle consisting of 10 Lachman's tests and ten maximum loading manual anterior drawer tests at 90° of flexion. Each knee was then flexed and extended fully ten times. The specimens were sectioned just proximal to the menisci and each suture anchor identified and its position recorded and photographed. Author: Author details: Kindly check and confirm whether the corresponding author mail id is correctly identified and amend if necessary. RESULTS: In the Ultra FastFix group, a single anchor was found to be in an intra-articular position-a failure rate of 2.5%. In the FastFix 360 group, 5 anchors failed-a 12.5% failure rate. In all cases, the anchors were attached to their suture and so not truly loose wit
Hoogeslag RAG, Brouwer RW, Huis In 't Veld R, et al., 2018, Dynamic augmentation restores anterior tibial translation in ACL suture repair: a biomechanical comparison of non-, static and dynamic augmentation techniques., Knee Surg Sports Traumatol Arthrosc
PURPOSE: There is a lack of objective evidence investigating how previous non-augmented ACL suture repair techniques and contemporary augmentation techniques in ACL suture repair restrain anterior tibial translation (ATT) across the arc of flexion, and after cyclic loading of the knee. The purpose of this work was to test the null hypotheses that there would be no statistically significant difference in ATT after non-, static- and dynamic-augmented ACL suture repair, and they will not restore ATT to normal values across the arc of flexion of the knee after cyclic loading. METHODS: Eleven human cadaveric knees were mounted in a test rig, and knee kinematics from 0° to 90° of flexion were recorded by use of an optical tracking system. Measurements were recorded without load and with 89-N tibial anterior force. The knees were tested in the following states: ACL-intact, ACL-deficient, non-augmented suture repair, static tape augmentation and dynamic augmentation after 10 and 300 loading cycles. RESULTS: Only static tape augmentation and dynamic augmentation restored ATT to values similar to the ACL-intact state directly postoperation, and maintained this after cyclic loading. However, contrary to dynamic augmentation, the ATT after static tape augmentation failed to remain statistically less than for the ACL-deficient state after cyclic loading. Moreover, after cyclic loading, ATT was significantly less with dynamic augmentation when compared to static tape augmentation. CONCLUSION: In contrast to non-augmented ACL suture repair and static tape augmentation, only dynamic augmentation resulted in restoration of ATT values similar to the ACL-intact knee and decreased ATT values when compared to the ACL-deficient knee immediately post-operation and also after cyclic loading, across the arc of flexion, thus allowing the null hypotheses to be rejected. This may assist healing of the ruptured ACL. Therefore, this study would support further clinical evaluation of dyna
Junaid S, Gregory T, Fetherston S, et al., 2018, Cadaveric study validating in vitro monitoring techniques to measure the failure mechanism of glenoid implants against clinical CT., J Orthop Res
Definite glenoid implant loosening is identifiable on radiographs, however, identifying early loosening still eludes clinicians. Methods to monitor glenoid loosening in vitro have not been validated to clinical imaging. This study investigates the correlation between in vitro measures and CT images. Ten cadaveric scapulae were implanted with a pegged glenoid implant and fatigue tested to failure. Each scapulae were cyclically loaded superiorly and CT scanned every 20,000 cycles until failure to monitor progressive radiolucent lines. Superior and inferior rim displacements were also measured. A finite element (FE) model of one scapula was used to analyze the interfacial stresses at the implant/cement and cement/bone interfaces. All ten implants failed inferiorly at the implant-cement interface, two also failed at the cement-bone interface inferiorly, and three showed superior failure. Failure occurred at of 80,966 ± 53,729 (mean ± SD) cycles. CT scans confirmed failure of the fixation, and in most cases, was observed either before or with visual failure. Significant correlations were found between inferior rim displacement, vertical head displacement and failure of the glenoid implant. The FE model showed peak tensile stresses inferiorly and high compressive stresses superiorly, corroborating experimental findings. In vitro monitoring methods correlated to failure progression in clinical CT images possibly indicating its capacity to detect loosening earlier for earlier clinical intervention if needed. Its use in detecting failure non-destructively for implant development and testing is also valuable. The study highlights failure at the implant-cement interface and early signs of failure are identifiable in CT images. © 2018 The Authors. Journal of Orthopaedic Research® Published by Wiley Periodicals, Inc. on behalf of the Orthopaedic Research Society. J Orthop Res 9999:XX-XX, 2018.
Kanca Y, Milner P, Dini D, et al., 2018, Tribological properties of PVA/PVP blend hydrogels against articular cartilage, JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS, Vol: 78, Pages: 36-45, ISSN: 1751-6161
Kanca Y, Milner P, Dini D, et al., 2018, Tribological evaluation of biomedical polycarbonate urethanes against articular cartilage, JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS, Vol: 82, Pages: 394-402, ISSN: 1751-6161
Kittl C, Inderhaug E, Williams A, et al., 2018, Biomechanics of the Anterolateral Structures of the Knee, CLINICS IN SPORTS MEDICINE, Vol: 37, Pages: 21-+, ISSN: 0278-5919
Lord BR, Colaco HB, Gupte CM, et al., 2018, ACL graft compression: a method to allow reduced tunnel sizes in ACL reconstruction., Knee Surg Sports Traumatol Arthrosc
PURPOSE: A common problem during ACL reconstruction is asymmetry of proximal-distal graft diameter leading to tunnel upsizing and graft-tunnel mismatch. Compression downsizing provides a graft of uniform size, allowing easy passage into a smaller tunnel. The purpose of this study was to quantify the graft compression technique and its effects on graft biomechanics and stability. It was hypothesised that compression downsizing would significantly reduce cross-sectional area (CSA); that no significant changes in graft biomechanics would occur; graft fixation stability would be improved. METHOD: Sixty-eight non-irradiated peroneus longus (PL) tendons were investigated. Twenty were halved and paired into ten four-strand grafts, 20 strands were compressed by 0.5-1 mm diameter and changes in CSA recorded using an alginate mould technique. The following properties were compared with 20 control strands: cyclic strain when loaded 70-220 N for 1000 cycles; stiffness; ultimate tensile load and stress; Young's modulus. 24 PL tendons were quadrupled into grafts, 12 were compressed and all 24 were submerged in Ringer's solution at 37 °C and the CSA recorded over 12 h. Twelve compressed and 12 control quadrupled grafts were mounted in porcine femurs, placed in Ringer's solution for 12 h at 37 °C and graft displacement at the bone tunnel aperture recorded under cyclic loading. RESULTS: Mean decreases in CSA of 31% under a stress of 471 kPa and 21% under a stress of 447 kPa were observed for doubled and quadrupled grafts, respectively. Compressed grafts re-expanded by 19% over 12 h compared to 2% for controls. No significant differences were observed between compressed and control grafts in the biomechanical properties and graft stability; mean cyclic displacements were 0.3 mm for both groups. CONCLUSIONS: No detrimental biomechanical effects of graft compression on allograft PL tendons were observed. Following compression, t
Marsland D, Stephen JM, Calder T, et al., 2018, Strength of Interference Screw Fixation to Cuboid vs Pulvertaft Weave to Peroneus Brevis for Tibialis Posterior Tendon Transfer for Foot Drop., Foot Ankle Int
BACKGROUND: Tibialis posterior (TP) tendon transfer is an effective treatment for foot drop. Currently, standard practice is to immobilize the ankle in a cast for 6 weeks nonweightbearing, risking postoperative stiffness. To assess whether early active dorsiflexion and protected weightbearing could be safe, the current study assessed tendon displacement under cyclic loading and load to failure, comparing the Pulvertaft weave (PW) to interference screw fixation (ISF) in a cadaveric foot model. METHODS: Twenty-four cadaveric ankles had TP tendon transfer performed, 12 with the PW technique and 12 with ISF to the cuboid. The TP tendon was cycled 1000 times at 50 to 150 N and then loaded to failure in a materials testing machine. Tendon displacement at the insertion site was recorded every 100 cycles. An independent t test and 2-way analysis of variance were performed to compare techniques, with a significance level of P < .05. RESULTS: Mean tendon displacement was similar in the PW group (2.9 ± 2.5 mm [mean ± SD]) compared with the ISF group (2.4 ± 1.1 mm), P = .35. One specimen in the ISF group failed early by tendon pullout. None of the PW group failed early, although displacement of 8.9 mm was observed in 1 specimen. Mean load to failure was 419.1 ± 82.6 N in the PW group in comparison to 499.4 ± 109.6 N in the ISF group, P = .06. CONCLUSION: For TP tendon transfer, ISF and PW techniques were comparable, with no differences in tendon displacement after cyclical loading or load to failure. Greater variability was observed in the PW group, suggesting it may be a less reliable technique. CLINICAL RELEVANCE: The results indicate that early active dorsiflexion and protected weightbearing may be safe for clinical evaluation, with potential benefits for the patient compared with cast immobilization.
Marsland D, Stephen JM, Calder T, et al., 2018, Flexor digitorum longus tendon transfer to the navicular: tendon-to-tendon repair is stronger compared with interference screw fixation., Knee Surg Sports Traumatol Arthrosc
PURPOSE: To assess whether early rehabilitation could be safe after flexor digitorum longus (FDL) tendon transfer, the current biomechanical study aimed to measure tendon displacement under cyclic loading and load to failure, comparing a traditional tendon-to-tendon (TT) repair with interference screw fixation (ISF). METHODS: 24 fresh-frozen cadaveric below knee specimens underwent FDL tendon transfer. In 12 specimens a TT repair was performed via a navicular bone tunnel. In a further 12 specimens ISF was performed. Using a materials testing machine, the FDL tendon was cycled 1000 times to 150 N and tendon displacement at the insertion site measured. A final load to failure test was then performed. Statistical analysis was performed using two-way ANOVA and an independent t test, with a significance level of p < 0.05. RESULT: No significant difference in tendon displacement occurred after cyclic loading, with mean tendon displacements of 1.9 ± 1.2 mm (mean ± SD) in the TT group and 1.8 ± 1.5 mm in the ISF group (n.s.). Two early failures occurred in the ISF group, none in the TT group. Mean load to failure was significantly greater following TT repair (459 ± 96 N), compared with ISF (327 ± 76 N), p = 0.002. CONCLUSION: Minimal tendon displacement of less than 2 mm occurred during cyclic testing in both groups. The two premature failures and significantly reduced load to failure observed in the ISF group, however, indicate that the traditional TT technique is more robust. Regarding clinical relevance, this study suggests that early active range of motion and protected weight bearing may be safe following FDL tendon transfer for stage 2 tibialis posterior tendon dysfunction.
Musahl V, Getgood A, Neyret P, et al., 2018, Erratum to: Contributions of the anterolateral complex and the anterolateral ligament to rotatory knee stability in the setting of ACL Injury: a roundtable discussion (Knee Surgery, Sports Traumatology, Arthroscopy, (2017), 25, 4, (997-1008), 10.1007/s00167-017-4436-7), Knee Surgery, Sports Traumatology, Arthroscopy, Vol: 26, ISSN: 0942-2056
© 2016, European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA). In the original article, one of the co-authors’ name has been published incorrectly. The correct name should be Jeremy M. Burnham. The original article has been updated accordingly.
Stephen JM, Sopher R, Tullie S, et al., 2018, The infrapatellar fat pad is a dynamic and mobile structure, which deforms during knee motion, and has proximal extensions which wrap around the patella., Knee Surg Sports Traumatol Arthrosc
PURPOSE: The infrapatellar fat pad (IFP) is a common cause of knee pain and loss of knee flexion and extension. However, its anatomy and behavior are not consistently defined. METHODS: Thirty-six unpaired fresh frozen knees (median age 34 years, range 21-68) were dissected, and IFP attachments and volume measured. The rectus femoris was elevated, suprapatellar pouch opened and videos recorded looking inferiorly along the femoral shaft at the IFP as the knee was flexed. The patellar retinacula were incised and the patella reflected distally. The attachment of the ligamentum mucosum (LMuc) to the intercondylar notch was released from the anterior cruciate ligament (ACL), both menisci and to the tibia via meniscotibial ligaments. IFP strands projecting along both sides of the patella were elevated and the IFP dissected from the inferior patellar pole. Magnetic resonance imaging (MRI) of one knee at ten flexion angles was performed and the IFP, patella, tibia and femur segmented. RESULTS: In all specimens the IFP attached to the inferior patellar pole, femoral intercondylar notch (via the LMuc), proximal patellar tendon, intermeniscal ligament, both menisci and the anterior tibia via the meniscotibial ligaments. In 30 specimens the IFP attached to the anterior ACL fibers via the LMuc, and in 29 specimens it attached directly to the central anterior tibia. Proximal IFP extensions were identified alongside the patella in all specimens and visible on MRI [medially (100% of specimens), mean length 56.2 ± 8.9 mm, laterally (83%), mean length 23.9 ± 6.2 mm]. Mean IFP volume was 29.2 ± 6.1 ml. The LMuc, attached near the base of the middle IFP lobe, acting as a 'tether' drawing it superiorly during knee extension. The medial lobe consistently had a pedicle superomedially, positioned between the patella and medial trochlea. MRI scans demonstrated how the space between the anterior tibia and patellar t
Amirthanayagam TD, Amis AA, Reilly P, et al., 2017, Rotator cuff-sparing approaches for glenohumeral joint access: an anatomic feasibility study, JOURNAL OF SHOULDER AND ELBOW SURGERY, Vol: 26, Pages: 512-520, ISSN: 1058-2746
Amis A, Zaffagnini S, Musahl V, 2017, The anterolateral aspect of the knee: the state of play., Knee Surg Sports Traumatol Arthrosc, Vol: 25, Pages: 989-990
Amis AA, 2017, Anterolateral knee biomechanics, KNEE SURGERY SPORTS TRAUMATOLOGY ARTHROSCOPY, Vol: 25, Pages: 1015-1023, ISSN: 0942-2056
Athwal KK, El Daou H, Inderhaug E, et al., 2017, An in vitro analysis of medial structures and a medial soft tissue reconstruction in a constrained condylar total knee arthroplasty, KNEE SURGERY SPORTS TRAUMATOLOGY ARTHROSCOPY, Vol: 25, Pages: 2646-2655, ISSN: 0942-2056
Athwal KK, El Daou H, Inderhaug E, et al., 2017, An in vitro analysis of medial structures and a medial soft tissue reconstruction in a constrained condylar total knee arthroplasty (vol 25, pg 2646, 2016), KNEE SURGERY SPORTS TRAUMATOLOGY ARTHROSCOPY, Vol: 25, Pages: 2656-2656, ISSN: 0942-2056
Athwal KK, El Daou H, Lord B, et al., 2017, Lateral soft-tissue structures contribute to cruciate-retaining total knee arthroplasty stability, JOURNAL OF ORTHOPAEDIC RESEARCH, Vol: 35, Pages: 1902-1909, ISSN: 0736-0266
Cheong VS, Karunaratne A, Amis AA, et al., 2017, Strain rate dependency of fractures of immature bone, JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS, Vol: 66, Pages: 68-76, ISSN: 1751-6161
Colaco HB, Lord BR, Back DL, et al., 2017, Biomechanical properties of bovine tendon xenografts treated with a modern processing method, JOURNAL OF BIOMECHANICS, Vol: 53, Pages: 144-147, ISSN: 0021-9290
El Daou H, Lord B, Amis A, et al., 2017, Assessment of pose repeatability and specimen repositioning of a robotic joint testing platform, MEDICAL ENGINEERING & PHYSICS, Vol: 47, Pages: 210-213, ISSN: 1350-4533
Geraldes DM, Hansen U, Amis AA, 2017, Parametric Analysis of Glenoid Implant Design and Fixation Type, JOURNAL OF ORTHOPAEDIC RESEARCH, Vol: 35, Pages: 775-784, ISSN: 0736-0266
Geraldes DM, Hansen U, Jeffers J, et al., 2017, Stability of small pegs for cementless implant fixation, JOURNAL OF ORTHOPAEDIC RESEARCH, Vol: 35, Pages: 2765-2772, ISSN: 0736-0266
Getgood A, LaPrade RF, Verdonk P, et al., 2017, International Meniscus Reconstruction Experts Forum (IMREF) 2015 Consensus Statement on the Practice of Meniscal Allograft Transplantation, American Journal of Sports Medicine, Vol: 45, Pages: 1195-1205, ISSN: 0363-5465
© 2017 The Author(s). Meniscal allograft transplantation (MAT) has become relatively commonplace in specialized sport medicine practice for the treatment of patients with a symptomatic knee after the loss of a functional meniscus. The technique has evolved since the 1980s, and long-term results continue to improve. However, there still remains significant variation in how MAT is performed, and as such, there remains opportunity for outcome and graft survivorship to be optimized. The purpose of this article was to develop a consensus statement on the practice of MAT from key opinion leaders who are members of the International Meniscus Reconstruction Experts Forum so that a more standardized approach to the indications, surgical technique, and postoperative care could be outlined with the goal of ultimately improving patient outcomes.
Inderhaug E, Stephen JM, El-Daou H, et al., 2017, The Effects of Anterolateral Tenodesis on Tibiofemoral Contact Pressures and Kinematics, AMERICAN JOURNAL OF SPORTS MEDICINE, Vol: 45, Pages: 3081-3088, ISSN: 0363-5465
Inderhaug E, Stephen JM, Williams A, et al., 2017, Biomechanical Comparison of Anterolateral Procedures Combined With Anterior Cruciate Ligament Reconstruction, AMERICAN JOURNAL OF SPORTS MEDICINE, Vol: 45, Pages: 347-354, ISSN: 0363-5465
Inderhaug E, Stephen JM, Williams A, et al., 2017, Anterolateral Tenodesis or Anterolateral Ligament Complex Reconstruction Effect of Flexion Angle at Graft Fixation When Combined With ACL Reconstruction, AMERICAN JOURNAL OF SPORTS MEDICINE, Vol: 45, Pages: 3089-3097, ISSN: 0363-5465
Iranpour F, Merican AM, Teo SH, et al., 2017, Femoral articular geometry and patellofemoral stability, KNEE, Vol: 24, Pages: 555-563, ISSN: 0968-0160
Junaid S, Sanghavi S, Anglin C, et al., 2017, Treatment of the Fixation Surface Improves Glenoid Prosthesis Longevity in vitro, JOURNAL OF BIOMECHANICS, Vol: 61, Pages: 81-87, ISSN: 0021-9290
Kittl C, Inderhaug E, Stephen J, et al., 2017, Scientific basis and surgical technique for iliotibial band tenodesis combined with ACL reconstruction, Controversies in the Technical Aspects of ACL Reconstruction: An Evidence-Based Medicine Approach, Pages: 393-404, ISBN: 9783662527429
© ISAKOS 2017. Anatomy: Due to the complexity of the lateral side of the knee, it may be best to describe these structures in terms of three tissue layers from superficial to deep. The distal part of the fascia lata - (1) the superficial layer of the iliotibial band (ITB) - is tethered to the distal femur by the (2) deep and capsulo-osseous fibres of the ITB. Removal of these ITB layers exposes the (3) anterolateral capsule and other deeper structures, which has been described as including the anterolateral ligament (ALL) with differing interpretations. Biomechanics: The anterior cruciate ligament (ACL) and the ITB have been shown to be the primary restraints to anterior tibial translation and internal tibial rotatio n, respectively. An injury of the ACL and the anterolateral structures may therefore result in a combined translatory and rotatory instability, called anterolateral rotatory instability (ALRI). As a logical rationale, a surgical intervention would include an intra-articular ACL reconstruction alongside a reconstruction of the anterolateral structures. This has been shown to restore normal knee kinematics in a simulated ALRI-injured knee. Conclusion: The anatomy of the anterolateral side is complex and yet not fully understood. Thus, there is an urgent need for a standardised nomenclature/terminology for these structures. A combined ALRI injury may be treated with an intra-articular ACL reconstruction and a nonanatomic ITB tenodesis.
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