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Questions and Answers
In the context of hindfoot biomechanics following simulated arthrodesis, which joint, upon fixation, most profoundly diminishes the motion of the remaining joints within the triple joint complex?
In the context of hindfoot biomechanics following simulated arthrodesis, which joint, upon fixation, most profoundly diminishes the motion of the remaining joints within the triple joint complex?
- Talonavicular joint (correct)
- Ankle joint
- Calcaneocuboid joint
- Subtalar joint
Isolated arthrodesis of the calcaneocuboid joint is expected to substantially limit the motion of the subtalar joint due to their biomechanical interdependence.
Isolated arthrodesis of the calcaneocuboid joint is expected to substantially limit the motion of the subtalar joint due to their biomechanical interdependence.
False (B)
Following the methodology described, if excessive motion is detected at the subtalar joint subsequent to its simulated arthrodesis, what specific data points are excluded from the statistical analysis, and why?
Following the methodology described, if excessive motion is detected at the subtalar joint subsequent to its simulated arthrodesis, what specific data points are excluded from the statistical analysis, and why?
Data from that arthrodesis and any subsequent conditions are excluded to ensure the integrity of the data.
The accuracy of the magnetic space tracking system is affected by the amount of ______ in the field and the distance between the sensor and the source.
The accuracy of the magnetic space tracking system is affected by the amount of ______ in the field and the distance between the sensor and the source.
Match each type of simulated arthrodesis with its primary effect on posterior tibial tendon excursion:
Match each type of simulated arthrodesis with its primary effect on posterior tibial tendon excursion:
When employing tendon pulls to simulate foot motion in cadaveric models, what is the rationale for utilizing the peroneus brevis and posterior tibial tendons as the primary movers?
When employing tendon pulls to simulate foot motion in cadaveric models, what is the rationale for utilizing the peroneus brevis and posterior tibial tendons as the primary movers?
The loads applied to the peroneus brevis and posterior tibial tendons during simulated pronation and supination were standardized across all specimens to ensure uniform biomechanical stress.
The loads applied to the peroneus brevis and posterior tibial tendons during simulated pronation and supination were standardized across all specimens to ensure uniform biomechanical stress.
Detail the specific methodology undertaken to affix the sensors of the magnetic space tracking system to the individual bones of the foot, ensuring minimal artifact and maximal stability during kinematic data acquisition.
Detail the specific methodology undertaken to affix the sensors of the magnetic space tracking system to the individual bones of the foot, ensuring minimal artifact and maximal stability during kinematic data acquisition.
To maintain the position of the foot during simulated arthrodesis the foot was held in a neutral ______ position while each joint was fixed.
To maintain the position of the foot during simulated arthrodesis the foot was held in a neutral ______ position while each joint was fixed.
Match the following arthrodesis procedures with their expected impact on the remaining range of motion (ROM) in the foot:
Match the following arthrodesis procedures with their expected impact on the remaining range of motion (ROM) in the foot:
Which statement accurately reflects the impact of simulated arthrodesis on the excursion of the posterior tibial tendon, considering the interrelationships within the triple joint complex?
Which statement accurately reflects the impact of simulated arthrodesis on the excursion of the posterior tibial tendon, considering the interrelationships within the triple joint complex?
The clinical outcomes reported by Lapidus, indicating better compensatory motion after subtalar versus talonavicular arthrodesis, directly contradict the in vitro biomechanical findings of reduced motion in remaining joints following talonavicular arthrodesis.
The clinical outcomes reported by Lapidus, indicating better compensatory motion after subtalar versus talonavicular arthrodesis, directly contradict the in vitro biomechanical findings of reduced motion in remaining joints following talonavicular arthrodesis.
Explain the rationale for stabilizing the ankle joint with large screws in a neutral position prior to assessing the motion characteristics of the triple joint complex.
Explain the rationale for stabilizing the ankle joint with large screws in a neutral position prior to assessing the motion characteristics of the triple joint complex.
Hall and Pennal estimated that after arthrodesis of the subtalar joint ______ to ______ percent of transverse tarsal motion remained.
Hall and Pennal estimated that after arthrodesis of the subtalar joint ______ to ______ percent of transverse tarsal motion remained.
Match each author or group of authors with their primary contribution to the understanding of hindfoot arthrodesis:
Match each author or group of authors with their primary contribution to the understanding of hindfoot arthrodesis:
In the context of this study, what constitutes the primary justification for considering a flexor digitorum longus (FDL) transfer to the navicular tuberosity in conjunction with hindfoot arthrodesis?
In the context of this study, what constitutes the primary justification for considering a flexor digitorum longus (FDL) transfer to the navicular tuberosity in conjunction with hindfoot arthrodesis?
The presence of osteoarthrosis in the cadaveric foot specimens would have enhanced the accuracy and generalizability of the simulated arthrodesis results by more closely mimicking clinical pathology.
The presence of osteoarthrosis in the cadaveric foot specimens would have enhanced the accuracy and generalizability of the simulated arthrodesis results by more closely mimicking clinical pathology.
Describe the potential clinical implications of the study's finding that arthrodesis of the talonavicular joint dramatically restricts motion of the remaining joints, particularly concerning the long-term biomechanical adaptation of the foot.
Describe the potential clinical implications of the study's finding that arthrodesis of the talonavicular joint dramatically restricts motion of the remaining joints, particularly concerning the long-term biomechanical adaptation of the foot.
According to the study the average excursion of the posterior tibial tendon before arthrodesis simulations was ______ $\pm$ ______ millimeters.
According to the study the average excursion of the posterior tibial tendon before arthrodesis simulations was ______ $\pm$ ______ millimeters.
Match each arthrodesis type with its primary effect on the excursion of the posterior tibial tendon:
Match each arthrodesis type with its primary effect on the excursion of the posterior tibial tendon:
Which joint in the triple joint complex has the greatest range of motion?
Which joint in the triple joint complex has the greatest range of motion?
Arthrodesis of the calcaneocuboid joint severely limits the motion of the subtalar joint.
Arthrodesis of the calcaneocuboid joint severely limits the motion of the subtalar joint.
Motion of the joints of the foot cannot be accurately measured with an external _________.
Motion of the joints of the foot cannot be accurately measured with an external _________.
What is the primary purpose of the study described?
What is the primary purpose of the study described?
The posterior tibial tendon excursion is least affected by the flexion of the ankle.
The posterior tibial tendon excursion is least affected by the flexion of the ankle.
Match each joint with its effect on subtalar joint motion when arthrodesed:
Match each joint with its effect on subtalar joint motion when arthrodesed:
What two muscles are identified as the principal muscles acting on the triple joint complex?
What two muscles are identified as the principal muscles acting on the triple joint complex?
According to the study, what percentage of the posterior tibial tendon excursion remains after simulated arthrodesis of the subtalar joint?
According to the study, what percentage of the posterior tibial tendon excursion remains after simulated arthrodesis of the subtalar joint?
The study used radiographic evidence to include feet with osteoarthrosis.
The study used radiographic evidence to include feet with osteoarthrosis.
What type of system was used to monitor the 3D locations of the bones in the foot?
What type of system was used to monitor the 3D locations of the bones in the foot?
To simulate arthrodesis in the study, a combination of at least two screws or ____________ pins were used across the joint to be fixed.
To simulate arthrodesis in the study, a combination of at least two screws or ____________ pins were used across the joint to be fixed.
What two loading conditions were used to represent pronation and supination of the foot?
What two loading conditions were used to represent pronation and supination of the foot?
Which arthrodesis preserves the most excursion of the posterior tibial tendon?
Which arthrodesis preserves the most excursion of the posterior tibial tendon?
The authors suggest that transfer of the flexor digitorum longus tendon to the navicular tuberosity, to restore function of a ruptured or otherwise non-functional posterior tibial tendon, will also maintain its excursion if the talonavicular joint remains mobile.
The authors suggest that transfer of the flexor digitorum longus tendon to the navicular tuberosity, to restore function of a ruptured or otherwise non-functional posterior tibial tendon, will also maintain its excursion if the talonavicular joint remains mobile.
What level of significance (p-value) was used for statistical analysis in the study?
What level of significance (p-value) was used for statistical analysis in the study?
According to the study, simulated arthrodesis of the __________ joint resulted in a significant decrease in the range of motion of the calcaneocuboid joint.
According to the study, simulated arthrodesis of the __________ joint resulted in a significant decrease in the range of motion of the calcaneocuboid joint.
Explain why motion at the ankle was eliminated in this study.
Explain why motion at the ankle was eliminated in this study.
What was the manufacturer-specified accuracy of the magnetic tracking system used in this study for translational axes when the sensor was 30 inches from the source?
What was the manufacturer-specified accuracy of the magnetic tracking system used in this study for translational axes when the sensor was 30 inches from the source?
The study showed that simulated arthrodesis of the calcaneocuboid joint significantly decreases the motion of the posterior tibial tendon.
The study showed that simulated arthrodesis of the calcaneocuboid joint significantly decreases the motion of the posterior tibial tendon.
Match each arthrodesis with the percentage of the preoperative value of the posterior tibial tendon excursion retained:
Match each arthrodesis with the percentage of the preoperative value of the posterior tibial tendon excursion retained:
Flashcards
Arthrodesis of the foot
Arthrodesis of the foot
Surgical immobilization of one or more tarsal joints.
Talonavicular Joint
Talonavicular Joint
Key joint; greatest range of motion; its arthrodesis limits other joints.
Triple Joint Complex Function
Triple Joint Complex Function
Accommodates ground variations and lower extremity rotation.
Posterior Tibial and Peroneal Muscles
Posterior Tibial and Peroneal Muscles
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Posterior Tibial Tendon Excursion
Posterior Tibial Tendon Excursion
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Motion Preservation
Motion Preservation
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Arthrodesis
Arthrodesis
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Triple Arthrodesis
Triple Arthrodesis
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Magnetic Space Tracking System
Magnetic Space Tracking System
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Talonavicular Fixation
Talonavicular Fixation
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Isolated Subtalar Benefit
Isolated Subtalar Benefit
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TN Fixation Motion
TN Fixation Motion
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Simulated Motion
Simulated Motion
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Flexor Digitorum Longus
Flexor Digitorum Longus
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Study Notes
Motion of the Hindfoot after Simulated Arthrodesis
- Simulated arthrodesis was performed on cadaver models to measure the range of motion in joints not involved in the procedure, using a 3D magnetic space tracking system
- The excursion of the posterior tibial tendon was measured under simulated arthrodesis conditions, and it was discovered that any combination including the talonavicular joint severely restricted motion in remaining joints (approximately 2 degrees)
- Excursion of the posterior tibial tendon was limited to 25% of the preoperative value
Calcaneocuboid Joint Impact
- Simulated arthrodesis has little effect on subtalar joint motion range
- Talonavicular joint range of motion decreases to 67% of its preoperative value
- A mean of 73% of the posterior tibial tendon excursion was retained
Subtalar Joint Impact
- Simulated arthrodesis results in a mean of 26% of the motion of the talonavicular joint
- A mean of 56% of the motion of the calcaneocuboid joint remains
- There is a 46% retention of the excursion of the posterior tibial tendon
Key Joint
- The Talonavicular joint is the key joint of the triple joint complex, possessing the greatest range of motion
- Simulated arthrodesis essentially eliminates motion in other joints of the complex.
Clinical Relevance
- Arthrodesis of any joints within the triple joint complex (subtalar, talonavicular, calcaneocuboid) limits motion in the remaining, unfused joints
- Quantifying the limitation of motion in each joint after arthrodesis of other joints is important to understand the clinical implications
- Ascertaining the effect of these joint motion limitations on the posterior tibial tendon excursion helps determine when tendon reconstruction is appropriate with arthrodesis
Triple Joint Complex
- Motion facilitates adaptation to variations in ground surface and rotation from the lower extremity
- The amount of motion remaining after different arthrodeses hasn't been accurately measured, even though gross differences have been recognized in vivo and in vitro
- Mann and Baumgarten estimated approximately 50% of transverse tarsal joint motion remains after subtalar joint arthrodesis, advocating isolated subtalar joint arthrodesis over triple when possible
- Fogel et al. found that isolated talonavicular joint arthrodesis limited subtalar motion clinically, while Gellman et al. used a manual goniometer with reference pins to measure foot and ankle motion in vitro after simulated arthrodeses of the ankle and tarsal joints
- They did not include arthrodesis of the talonavicular/calcaneocuboid joints or measure individual joints
Goniometer Limitations
- A goniometer cannot measure the motion of the foot joints accurately
- Measuring positional changes of individual foot bones in 3D space with a 3D magnetic space tracking system is possible
- This system has been previously used to study wrist mechanics
Pronation and Supination
- The majority of pronation and supination in the foot occurs in the triple joint complex, with the posterior tibial and peroneal muscles acting on these joints
- Arthrodesis in the triple joint complex affects the posterior tibial tendon excursion
Tendon Transfer
- Determine when to perform a transfer of the flexor digitorum longus tendon to replace a ruptured or non-functional posterior tibial tendon concomitantly with arthrodesis, in vitro data is used to quantify the effect of selected joints of the triple joint complex on the range of motion of the remaining joints and the posterior tibial tendon excursion
Materials and Methods
- Ten fresh-frozen cadaveric foot specimens with normal posterior tibial tendons and no osteoarthrosis evidence were used
- The ankle was fixed in a neutral position with screws, to isolate motion in triple joint complex
- The 3D locations of the talus, calcaneus, navicular, and cuboid were monitored with a magnetic space tracking system (Fastrak; Polhemus Navigational Sciences Division, Colchester, Vermont)
- The accuracy of the tracking system was determined as 0.1mm along each translational axis and 0.1 degree about each rotational axis, the manufacturer determined the accuracy of the tracking system at 0.8mm along each of the three translational axes and 0.15 degrees about each of the three rotational axes with the sensor 30 inches from the source
- The magnetic source of the space tracking system was fixed to the test frame, and the sensors were attached to each of the four bones
- The position of the sensor was selected so they did not come in contact throughout the foot's range of motion
- Each sensor was mounted on a small Plexiglas plate connected to two 3.0mm carbon vinyl ester pins to rigidly attach each sensor to each bone, using two pins to prevent rotation at the pin-bone interface
Test Apparatus
- Specimens were placed plantar side up in the testing apparatus to stabilize the tibia, allowing unrestricted foot motion, and simplifying the use of weights/wires
- Tendon pulls were used to move the foot through a reproducible range of motion without imposing an artificial axis of motion
- The tendons of the posterior tibial and peroneus brevis were selected as they are antagonists, a pull on the peroneus longus tendon had no effect
- Stainless steel wires were sutured to the posterior tibial and peroneus brevis tendons, attached to gauges measuring linear displacement
- The use of pulleys allowed a direct line of pull on each tendon, it also enabled the excursion of these tendons to be measured
Pronation vs Supination
- The load on the peroneus brevis tendon defines pronation, the load on the posterior tibial tendon is defined as supination
- A 36-newton load was placed on the peroneus brevis tendon, and an 11-newton load was placed on the posterior tibial tendon (exchanged for supinated foot)
- Each simulated arthrodesis had linear displacement readings for the excursion of the posterior tibial tendon, and 3D positions of bones, recorded for three supination and three pronation trials
- Conditions included no arthrodesis, arthrodesis of the subtalar joint, triple arthrodesis, double arthrodesis, arthrodesis of the talonavicular joint, and arthrodesis of the calcaneocuboid joint (order maintained)
Data Collection
- Held in a neutral plantigrade position while each joint was fixed and fixed with the heel in the neutral position
- Screws or threaded pins were placed across the joint without cartilage removal to simulate arthrodesis
- From the data collected, the talonavicular, subtalar, calcaneocuboid joint excursion ranges along with the posterior tibial tendon's excursion were calculated for each condition from full supination to full pronation using statistical analysis
Statistical Methods and Results
- Statistical analysis was performed with each foot acting as its own control
- Applying variance with pair-wise comparisons with bonferroni corrections
- P<0.05 was used for significance
- If 3 degrees of motion/more occurred it was excluded
- The talonavicular joint had the greatest range of motion (36.7 +-13degrees), followed by the subtalar joint (20.4+-8 degrees), and the calcaneocuboid joint (14.4 +- 6 degrees) in the tested feet
- Simulated talonavicular and double arthrodesis limited subtalar joint motion
- Decreased the range of motion of the talonavicular and calcaneocuboid joints
- Calcaneocuboid joint arthrodesis had little effect
- Simulated arthrodesis of the subtalar joint resulted in a significant decrease in the range of motion of the talonavicular and calcaneocuboid joints
Tendon Excursion
- Was 17+-5 millimeters before simulated arthrodesis
- A mean of 73% of the excursion was maintained after calcaneocuboid joint arthrodesis, all talonavicular joint arthrodesis involved significantly decreasing posterior tibial tendon Excursion
- Subtalar joint and talonavicular joint arthrodesis decreased the tendon excursion
- There was a remaining excursion after double and talonavicular arthrodesis
Clinical Examples
- The foot that had arthrodesis of the subtalar joint reported better compensatory motion, while Mann and Baumgarten said about 50% of the transverse tarsal was maintained
- The present study found a mean of 26% of the motion, and 56% of the calcaneocuboid after simulated Subtalar
- A previous study noted Subtalar and Transverse tarsal limitations, and this clinical result is in accordance with studies that found the subtalar and calcaneocuboid joints remained after stimulated
- Simulated arthrodesis is associated with motion that the joint had before the arthrodesis along with a number of joints influenced
- Calcaneocuboid had least effects and motion versus talonavicular with the most, the talonavicular joint restricted motion more than other joints
- After this the motion was limited to around 2 degrees which was the same as the motion after simulated arthrodesis
Tibial Tendon Excursion
- Mean excursion is consistent with previous studies
- 73 per cent with calcaneocuboid along with 46 per cent of the latter, excursive restrictions included talonavicular
- Mobility affects the tendon
Study Conclusion
- Calcaneocuboid preserves mobility, therefore the tendon can still restore, function in conjunction with calcaneocuboid or possibly subtalar, both preserve the motion, motion of the talonavicular joint is the key of motion
- Limits limits for the other joints
- With some motion also consistent results are postoperative
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