Contact Forces Acting on Large Femoral Osteochondral Allografts During Forced Knee Extension

2017 ◽  
Vol 45 (12) ◽  
pp. 2804-2811 ◽  
Author(s):  
Peter Z. Du ◽  
Keith L. Markolf ◽  
Christopher J. Lama ◽  
David R. McAllister ◽  
Kristofer J. Jones
Keyword(s):  
Clinical Relevance ◽  
Knee Extension ◽  
Load Cell ◽  
Contact Forces ◽  
Osteochondral Allograft ◽  
Human Knee ◽  
Native Bone ◽  
Load Cells ◽  
The Mean ◽  
Femoral Condyles

Background: A single cylindrical graft plug is commonly used for large focal femoral defects during osteochondral allograft (OCA) transplantation. Excessive contact force (CF) on a proud plug could compromise initial healing. CFs during forced knee extension are of particular interest because this maneuver is used by therapists to restore early postoperative range of motion. Hypothesis: A proud OCA plug will significantly increase the CF and significantly decrease the knee extension angle (KEA). Study Design: Controlled laboratory study. Methods: Eleven human knee specimens had miniature load cells installed in both femoral condyles at standardized locations representative of clinical defects. Each load cell had a 20-mm–diameter cylinder of native bone/cartilage attached at its precise anatomic location. Four spacers, 0.5 mm in thickness, were inserted sequentially between each load cell and its mounting bracket to create proud plug conditions of 0.5 to 2 mm. Measurements of the CF and KEA were recorded at extension moment levels up to 8 N·m. Results: At 8 N·m, the mean CFs for flush plugs were 149 ± 18 N (lateral) and 34 ± 13 N (medial). The mean increases in the medial CF (compared with flush) for 0.5-mm, 1-mm, 1.5-mm, and 2-mm proud conditions were 31 N (+91%), 64 N (+188%), 111 N (+325%), and 154 N (+451%), respectively. Corresponding increases for lateral proud plugs were 55 N (+37%), 120 N (+81%), 162 N (+109%), and 210 N (+141%), respectively. The CFs (and CF increases) for lateral grafts were significantly ( P < .05) higher than corresponding values for medial grafts at each proudness condition. Medial plug proudness had no consistent effect on the KEA. A 1-mm proud lateral plug significantly reduced the KEA by −1.6° (0 N·m) and −0.9° (2 N·m). Conclusion: Graft proudness of only 0.5 mm significantly increased CFs during forced knee extension, emphasizing the surgical precision necessary to achieve normal CF levels. Clinical Relevance: It is believed that some amount of CF is beneficial in the early stages of graft healing, and our findings suggest that forced knee extension may be well suited for this purpose. However, the surgeon should be aware that large extension moments can also generate relatively high CFs, especially if the plug is proud.

Effects of Proud Large Osteochondral Plugs on Contact Forces and Knee Kinematics: A Robotic Study

2018 ◽  
Vol 46 (9) ◽  
pp. 2122-2127 ◽  
Author(s):  
Peter Z. Du ◽  
Keith L. Markolf ◽  
Daniel V. Boguszewski ◽  
Kent T. Yamaguchi ◽  
Christopher J. Lama ◽  
...  
Keyword(s):  
Lateral Meniscus ◽  
Knee Kinematics ◽  
Contact Forces ◽  
Osteochondral Allograft ◽  
Cartilage Defects ◽  
Tibial Rotation ◽  
Native Bone ◽  
Rotational Kinematics ◽  
Internal Tibial Rotation ◽  
Articular Cartilage Defects

Background: Osteochondral allograft (OCA) transplantation is used to treat large focal femoral condylar articular cartilage defects. A proud plug could affect graft survival by altering contact forces (CFs) and knee kinematics. Hypothesis: A proud OCA plug will significantly increase CF and significantly alter knee kinematics throughout controlled knee flexion. Study Design: Controlled laboratory study. Methods: Human cadaver knees had miniature load cells, each with a 20-mm-diameter cylinder of native bone/cartilage attached at its exact anatomic position, installed in both femoral condyles at standardized locations representative of clinical defects. Spacers were inserted to create proud plug conditions of +0.5, +1.0, and +1.5 mm. CFs and knee kinematics were recorded as a robot flexed the knee continuously from 0° to 50° under 1000 N of tibiofemoral compression. Results: CFs were increased significantly (vs flush) for all proudness conditions between 0° and 45° of flexion (medial) and 0° to 50° of flexion (lateral). At 20°, the average increases in medial CF for +0.5-mm, +1-mm, and +1.5-mm proudness were +80 N (+36%), +155 N (+70%), and +193 N (+87%), respectively. Corresponding increases with proud lateral plugs were +44 N (+14%), +90 N (+29%), and +118 N (+38%). CF increases for medial plugs at 20° of flexion were significantly greater than those for lateral plugs at all proudness conditions. At 50°, a 1-mm proud lateral plug significantly decreased internal tibial rotation by 15.4° and decreased valgus rotation by 2.5°. Conclusion: A proud medial or lateral plug significantly increased CF between 0° and 45° of flexion. Our results suggest that a medial plug at 20° may be more sensitive to graft incongruity than a lateral plug. The changes in rotational kinematics with proud lateral plugs were attributed to earlier contact between the proud plug’s surface and the lateral meniscus, leading to rim impingement with decreased tibial rotation. Clinical Relevance: Increased CF and altered knee kinematics from a proud femoral plug could affect graft viability. Plug proudness of only 0.5 mm produced significant changes in CF and knee kinematics, and the clinically accepted 1-mm tolerance may need to be reexamined in view of our findings.

Trochlear Contact Pressures after Straight Anteriorization of the Tibial Tuberosity

2008 ◽  
Vol 36 (10) ◽  
pp. 1953-1959 ◽  
Author(s):  
John-Paul H. Rue ◽  
Anne Colton ◽  
Stephanie M. Zare ◽  
Elizabeth Shewman ◽  
Jack Farr ◽  
...  
Keyword(s):  
Contact Area ◽  
Clinical Relevance ◽  
Knee Flexion ◽  
Patellofemoral Joint ◽  
Pressure Sensors ◽  
Contact Forces ◽  
Tibial Tuberosity ◽  
Before And After ◽  
The Mean ◽  
Contact Pressures

Background Anteromedialization of the tibial tuberosity has been shown to decrease mean total contact pressures of the lateral trochlea and to shift contact pressures to the medial trochlea. Hypothesis Modifying the anteromedialization osteotomy to a straight anteriorization osteotomy of the tibial tuberosity can decrease trochlear contact pressures without a resultant medial shift of forces to the medial trochlear contact area. Study Design Controlled laboratory study. Methods Ten cadavers were tested before and after straight anteriorization tibial tuberosity osteotomy by loading the extensor mechanism with 89.1 and 178.2 N at 0°, 30°, 60°, and 90° of flexion following a validated patellofemoral joint loading protocol. Contact pressures were measured with electroresistive pressure sensors placed directly on the trochlea. Results The mean trochlear contact pressures after osteotomy decreased significantly ( P < .05) for loads of 89.1 and 178.2 N at both 30° (23% and 20%, respectively) and 60° (18.7% and 31.9%, respectively) of knee flexion. The peak contact pressures decreased significantly ( P < .05) for loads of 89.1 and 178.2 N at 30° (24.3% and 27.0%, respectively) and 60° (31.9% and 24.5%, respectively) and for loads of 89.1 N at 90° (13.4%) of knee flexion. Conclusion The authors demonstrated significantly decreased trochlear contact forces after straight anteriorization osteotomy of the tibial tuberosity, without a significant resultant medial shift of the center of force. Clinical Relevance Straight anteriorization of the tibial tuberosity may be a useful adjunct for patients with medial articular defects of the patellar or trochlea in whom anteromedialization would be otherwise contraindicated.

scholarly journals Illustration of the connection between the vastus medialis obliquus muscle and the superficial medial collateral ligament of the knee: A human knee cadaveric study

2021 ◽  
Vol 12 (1) ◽  
pp. 431-438
Author(s):  
Mohamed Hamid Awadelseid
Keyword(s):  
Medial Collateral Ligament ◽  
Knee Extension ◽  
Distal Portion ◽  
Vastus Medialis ◽  
Collateral Ligament ◽  
Valgus Stress ◽  
Vastus Medialis Obliquus ◽  
Human Knee ◽  
Superficial Medial Collateral Ligament ◽  
The Mean

Background: While the anatomy of the medial part of the knee has been extensively described, the muscular connections to the superficial medial collateral ligament (sMCL) have not been sufficiently studied. The purpose of this study is to describe the anatomy of the musculo-ligamentous connection between the sMCL and the Vastus Medialis Obliquus muscle (VMO), and to describe its anatomy. Methods: Six Human Cadaveric knees were used in this study. Donors were 4 males and 2 females with a mean age of 49 years old. Dissection was performed in fixed knee extension and directed to show the area of the proximal attachment of the sMCL. Results: A musculo ligamentous connection between the distal portion of the Vastus medialis Obliquus muscle and the sMCL has been identified in our entire specimens. The mean mid substance width of this connection was 9.75 (8.7 -10.8) mm, the mean length was 29.3 (22.2-36.4) mm and the mean thickness was 1.3 (0.9-1.7) mm. Conclusion: The proximal femoral attachment of the sMCL is directly connected to the distal end of VMO. This connection may show that the sMCL can possibly assist in the dynamic stabilization of the knee during extension against valgus stress, through its tension by the contracted VMO muscle.

scholarly journals Design and Calibration of Robot Base Force/Torque Sensors and Their Application to Non-Collocated Admittance Control for Automated Tool Changing

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 2895
Author(s):  
Hubert Gattringer ◽  
Andreas Müller ◽  
Philip Hoermandinger
Keyword(s):  
Steel Plate ◽  
Robotic Manipulators ◽  
Indirect Measurement ◽  
Local Deformation ◽  
Contact Forces ◽  
The Novel ◽  
Admittance Control ◽  
Load Cells ◽  
Series Elastic Actuators ◽  
Automated Tool

Robotic manipulators physically interacting with their environment must be able to measure contact forces/torques. The standard approach to this end is attaching force/torque sensors directly at the end-effector (EE). This provides accurate measurements, but at a significant cost. Indirect measurement of the EE-loads by means of torque sensors at the actuated joint of a robot is an alternative, in particular for series-elastic actuators, but requires dedicated robot designs and significantly increases costs. In this paper, two alternative sensor concept for indirect measurement of EE-loads are presented. Both sensors are located at the robot base. The first sensor design involves three load cells on which the robot is mounted. The second concept consists of a steel plate with four spokes, at which it is suspended. At each spoke, strain gauges are attached to measure the local deformation, which is related to the load at the sensor plate (resembling the main principle of a force/torque sensor). Inferring the EE-load from the so determined base wrench necessitates a dynamic model of the robot, which accounts for the static as well as dynamic loads. A prototype implementation of both concepts is reported. Special attention is given to the model-based calibration, which is crucial for these indirect measurement concepts. Experimental results are shown when the novel sensors are employed for a tool changing task, which to some extend resembles the well-known peg-in-the-hole problem.

scholarly journals Sporting participation following the operative management of chondral defects of the knee at mid-term follow up: a systematic review and meta-analysis

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
P. G. Robinson ◽  
T. Williamson ◽  
I. R. Murray ◽  
K. Al-Hourani ◽  
T. O. White
Keyword(s):  
Systematic Review ◽  
Autologous Chondrocyte Implantation ◽  
Platelet Rich Plasma ◽  
Meta Analysis ◽  
Osteochondral Allograft ◽  
Chondral Defects ◽  
Chondrocyte Implantation ◽  
The Mean ◽  
Autologous Chondrocyte

Abstract Purpose The purpose of this study was to perform a systematic review of the reparticipation in sport at mid-term follow up in athletes who underwent biologic treatment of chondral defects in the knee and compare the rates amongst different biologic procedures. Methods A search of PubMed/Medline and Embase was performed in May 2020 in keeping with Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. The criteria for inclusion were observational, published research articles studying the outcomes and rates of participation in sport following biologic treatments of the knee with a minimum mean/median follow up of 5 years. Interventions included microfracture, osteochondral autograft transfer (OAT), autologous chondrocyte implantation (ACI), matrix-induced autologous chondrocyte implantation (MACI), osteochondral allograft, or platelet rich plasma (PRP) and peripheral blood stem cells (PBSC). A random effects model of head-to-head evidence was used to determine rates of sporting participation following each intervention. Results There were twenty-nine studies which met the inclusion criteria with a total of 1276 patients (67% male, 33% female). The mean age was 32.8 years (13–69, SD 5.7) and the mean follow up was 89 months (SD 42.4). The number of studies reporting OAT was 8 (27.6%), ACI was 6 (20.7%), MACI was 7 (24.1%), microfracture was 5 (17.2%), osteochondral allograft was 4 (13.8%), and one study (3.4%) reported on PRP and PBSC. The overall return to any level of sport was 80%, with 58.6% returning to preinjury levels. PRP and PBSC (100%) and OAT (84.4%) had the highest rates of sporting participation, followed by allograft (83.9%) and ACI (80.7%). The lowest rates of participation were seen following MACI (74%) and microfracture (64.2%). Conclusions High rates of re-participation in sport are sustained for at least 5 years following biologic intervention for chondral injuries in the knee. Where possible, OAT should be considered as the treatment of choice when prolonged participation in sport is a priority for patients. However, MACI may achieve the highest probability of returning to the same pre-injury sporting level. Level of evidence IV

No Difference in Outcomes Following Osteochondral Allograft with Fresh Precut Cores Compared to Hemi-Condylar Allografts

Cartilage ◽  
2021 ◽  
pp. 194760352110219
Author(s):  
Danielle H. Markus ◽  
Anna M. Blaeser ◽  
Eoghan T. Hurley ◽  
Brian J. Mannino ◽  
Kirk A. Campbell ◽  
...  
Keyword(s):  
Patient Reported Outcomes ◽  
Knee Injury ◽  
Lesion Size ◽  
Osteochondral Allograft ◽  
Osteochondral Lesions ◽  
Radiographic Outcomes ◽  
Significant Difference ◽  
Patient Reported ◽  
The Mean

Objective The purpose of the current study is to evaluate the clinical and radiographic outcomes at early to midterm follow-up between fresh precut cores versus hemi-condylar osteochondral allograft (OCAs) in the treatment of symptomatic osteochondral lesions. Design A retrospective review of patients who underwent an OCA was performed. Patient matching between those with OCA harvested from an allograft condyle/patella or a fresh precut allograft core was performed to generate 2 comparable groups. The cartilage at the graft site was assessed with use of a modified Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) scoring system and patient-reported outcomes were collected. Results Overall, 52 total patients who underwent OCA with either fresh precut OCA cores ( n = 26) and hemi-condylar OCA ( n = 26) were pair matched at a mean follow-up of 34.0 months (range 12 months to 99 months). The mean ages were 31.5 ± 10.7 for fresh precut cores and 30.9 ± 9.8 for hemi-condylar ( P = 0.673). Males accounted for 36.4% of the overall cohort, and the mean lesion size for fresh precut OCA core was 19.6 mm2 compared to 21.2 mm2 for whole condyle ( P = 0.178). There was no significant difference in patient-reported outcomes including Visual Analogue Scale, Knee Injury and Osteoarthritis Outcome Score for Joint Replacement, and Tegner ( P > 0.5 for each), or in MOCART score (69.2 vs. 68.3, P = 0.93). Conclusions This study found that there was no difference in patient-reported clinical outcomes or MOCART scores following OCA implantation using fresh precut OCA cores or size matched condylar grafts at early to midterm follow-up.

Fresh Osteochondral Allograft Transplantation: Is Graft Storage Time Associated With Clinical Outcomes and Graft Survivorship?

2017 ◽  
Vol 45 (10) ◽  
pp. 2260-2266 ◽  
Author(s):  
Kenneth J. Schmidt ◽  
Luís E. Tírico ◽  
Julie C. McCauley ◽  
William D. Bugbee
Keyword(s):  
Clinical Outcomes ◽  
Storage Time ◽  
Osteochondral Allograft ◽  
Prolonged Storage ◽  
Graft Size ◽  
Early Release ◽  
Fresh Osteochondral Allograft ◽  
Release Group ◽  
The Mean

Background: Regulatory concerns and the popularity of fresh osteochondral allograft (OCA) transplantation have led to a need for prolonged viable storage of osteochondral grafts. Tissue culture media allow a longer storage time but lead to chondrocyte death within the tissue. The long-term clinical consequence of prolonged storage is unknown. Hypothesis: Patients transplanted with OCAs with a shorter storage time would have lower failure rates and better clinical outcomes than those transplanted with OCAs with prolonged storage. Study Design: Cohort study; Level of evidence, 3. Methods: A matched-pair study was performed of 75 patients who received early release grafts (mean storage, 6.3 days [range, 1-14 days]) between 1997 and 2002, matched 1:1 by age, diagnosis, and graft size, with 75 patients who received late release grafts (mean storage time, 20.0 days [range, 16-28 days]) from 2002 to 2008. The mean age was 33.5 years, and the median graft size was 6.3 cm2. All patients had a minimum 2-year follow-up. Evaluations included pain, satisfaction, function, failures, and reoperations. Outcome measures included the modified Merle d’Aubigné-Postel (18-point) scale, International Knee Documentation Committee (IKDC) form, and Knee Society function (KS-F) scale. Clinical failure was defined as revision OCA transplantation or conversion to arthroplasty. Results: Among patients with grafts remaining in situ, the mean follow-up was 11.9 years (range, 2.0-16.8 years) and 7.8 years (range, 2.3-11.1 years) for the early and late release groups, respectively. OCA failure occurred in 25.3% (19/75) of patients in the early release group and 12.0% (9/75) of patients in the late release group ( P = .036). The median time to failure was 3.5 years (range, 1.7-13.8 years) and 2.7 years (range, 0.3-11.1 years) for the early and late release groups, respectively. The 5-year survivorship of OCAs was 85% for the early release group and 90% for the late release group ( P = .321). No differences in postoperative pain and function were noted between the groups. Ninety-one percent of the early release group and 93% of the late release group reported satisfaction with OCA results. Conclusion: The transplantation of OCA tissue with prolonged storage is safe and effective for large osteochondral lesions of the knee and has similar clinical outcomes and satisfaction to the transplantation of early release grafts.

scholarly journals The influence of muscle pennation angle and cross-sectional area on contact forces in the ankle joint

2016 ◽  
Vol 52 (1) ◽  
pp. 12-23 ◽  
Author(s):  
Ran S Sopher ◽  
Andrew A Amis ◽  
D Ceri Davies ◽  
Jonathan RT Jeffers
Keyword(s):  
Pennation Angle ◽  
Muscle Architecture ◽  
Cross Sectional Area ◽  
Contact Forces ◽  
Sectional Area ◽  
Muscle Forces ◽  
Cross Sectional ◽  
Contact Loads ◽  
The Mean ◽  
And Function

Data about a muscle’s fibre pennation angle and physiological cross-sectional area are used in musculoskeletal modelling to estimate muscle forces, which are used to calculate joint contact forces. For the leg, muscle architecture data are derived from studies that measured pennation angle at the muscle surface, but not deep within it. Musculoskeletal models developed to estimate joint contact loads have usually been based on the mean values of pennation angle and physiological cross-sectional area. Therefore, the first aim of this study was to investigate differences between superficial and deep pennation angles within each muscle acting over the ankle and predict how differences may influence muscle forces calculated in musculoskeletal modelling. The second aim was to investigate how inter-subject variability in physiological cross-sectional area and pennation angle affects calculated ankle contact forces. Eight cadaveric legs were dissected to excise the muscles acting over the ankle. The mean surface and deep pennation angles, fibre length and physiological cross-sectional area were measured. Cluster analysis was applied to group the muscles according to their architectural characteristics. A previously validated OpenSim model was used to estimate ankle muscle forces and contact loads using architecture data from all eight limbs. The mean surface pennation angle for soleus was significantly greater (54%) than the mean deep pennation angle. Cluster analysis revealed three groups of muscles with similar architecture and function: deep plantarflexors and peroneals, superficial plantarflexors and dorsiflexors. Peak ankle contact force was predicted to occur before toe-off, with magnitude greater than five times bodyweight. Inter-specimen variability in contact force was smallest at peak force. These findings will help improve the development of experimental and computational musculoskeletal models by providing data to estimate force based on both surface and deep pennation angles. Inter-subject variability in muscle architecture affected ankle muscle and contact loads only slightly. The link between muscle architecture and function contributes to the understanding of the relationship between muscle structure and function.

Effects of stimulation frequencies and patterns on performance of repetitive, nonisometric tasks

2002 ◽  
Vol 92 (1) ◽  
pp. 109-116 ◽  
Author(s):  
Maikutlo B. Kebaetse ◽  
Amanda E. Turner ◽  
Stuart A. Binder-Macleod
Keyword(s):  
Isometric Force ◽  
Knee Extension ◽  
Variable Frequency ◽  
Constant Frequency ◽  
Human Knee ◽  
Target Angle ◽  
Single Pattern ◽  
The Subject ◽  
Stimulation Pattern ◽  
Quadriceps Femoris Muscles

The purpose of this paper was to determine the effects of stimulation pattern and frequency on repetitive human knee movements. Quadriceps femoris muscles were stimulated against a load equal to 10% of each subject's maximum voluntary isometric force. The main variable of interest was the number of repetitions in which the leg reached a target angle of 40° of knee extension. Sixteen different trains were tested, including 1) six constant-frequency trains with frequencies ranging from 9 to 100 Hz, 2) five variable-frequency trains with an initial 5-ms triplet and mean frequencies ranging from 11 to 35 Hz, and 3) five doublet-frequency trains, which used doublets (2 pulses with a 5-ms interpulse interval) to replace single pulses, with mean frequencies of 17–57 Hz. Testing was stopped when the subject failed to reach the target angle for three consecutive activations. Results showed that no single pattern was best for all subjects. The 33- and 100-Hz constant-frequency trains, 35-Hz variable-frequency trains, and 27- and 36-Hz doublet frequency trains each met the target the most times for some subjects. The results showed that, under our testing conditions, higher frequency trains were better suited for producing repetitive knee movements than lower frequency trains.

scholarly journals Open Source Digitally Replicable Lab-Grade Scales

2020 ◽  
Author(s):  
Benjamin R. Hubbard ◽  
Joshua M. Pearce
Keyword(s):  
Open Source ◽  
Low Cost ◽  
Cost Savings ◽  
Load Cell ◽  
Significant Cost ◽  
Load Cells ◽  
The Cost ◽  
Cell Data ◽  
Precision Balance ◽  
Multiple Load

This study provides designs for a low-cost, easily replicable open source lab-grade digital scale that can be used as a precision balance. The design is such that it can be manufactured for use in most labs throughout the world with open source RepRap-class material extrusion-based 3-D printers for the mechanical components and readily available open source electronics including the Arduino Nano. Several versions of the design were fabricated and tested for precision and accuracy for a range of load cells. The results showed the open source scale was found to be repeatable within 0.1g with multiple load cells, with even better precision (0.01g) depending on load cell range and style. The scale tracks linearly with proprietary lab-grade scales, meeting the performance specified in the load cell data sheets, indicating that it is accurate across the range of the load cell installed. The smallest loadcell tested(100g) offers precision on the order of a commercial digital mass balance. The scale can be produced at significant cost savings compared to scales of comparable range and precision when serial capability is present. The cost savings increase significantly as the range of the scale increases and are particularly well-suited for resource-constrained medical and scientific facilities.

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