Lower Extremity Anatomy, Peripheral Nerve Anatomy, Surgical Anatomy
Conditions
Keywords
Tibial nerve, Superficial peroneal nerve, Deep peroneal nerve, Motor entry point, Cadaveric dissection, Hyperselective neurectomy
Brief summary
This completed descriptive cadaveric study mapped the motor entry points of lower-leg muscles supplied by the tibial, superficial peroneal, and deep peroneal nerves. Twenty fresh-frozen adult lower-limb specimens without prior trauma or surgery were examined. One extremity from each cadaver was selected by coin toss. Investigators performed standardized posterior, lateral, and anterior compartment dissections, followed each terminal motor branch to the point where it entered the target muscle, and measured its location relative to total leg length. For each muscle, motor entry point location was expressed as a proportion of leg length and summarized using the mean, standard deviation, and probability intervals corresponding to mean plus or minus one and two standard deviations. The study was designed to provide quantitative anatomical reference zones that may support surgical planning for hyperselective neurectomy and related lower-leg procedures.
Detailed description
Hyperselective neurectomy requires accurate localization of terminal motor branches and their neuromuscular entry points in the lower leg. This descriptive cadaveric study was designed to establish proportional anatomical reference zones for motor branches of the tibial, superficial peroneal, and deep peroneal nerves. Fresh-frozen adult lower-limb specimens without prior trauma or prior surgical intervention were examined. One extremity per cadaver was selected by coin toss. Standardized posterior, lateral, and anterior compartment dissections were performed to identify the tibial nerve and the common peroneal nerve, trace the superficial and deep peroneal divisions, and follow terminal motor branches to the point at which each branch entered the corresponding muscle. For tibial nerve branches, branch location was referenced to the posterior border of the tibia at the midpoint of the proximal epiphysis. For superficial and deep peroneal branches, the proximal reference point was the most superior aspect of the fibular head on its anterior surface. The distal reference point was the point of entry into the target muscle. Total leg length was measured from the knee joint line to the ankle joint line. The motor entry point was calculated as the distance to the entry point divided by total leg length. Distributions were evaluated separately for each muscle using the Shapiro-Wilk test. Means and standard deviations were calculated, and probability intervals corresponding to mean plus or minus one standard deviation and mean plus or minus two standard deviations were used to define the most likely anatomical zones of motor branch entry. When required, logarithmic, square-root, or power transformations were used to approximate normality, with results expressed on the original proportional scale.
Interventions
OTHERStandardized Cadaveric Lower-Limb Dissection
Standardized posterior, lateral, and anterior compartment dissections were performed. The tibial nerve was identified through the posterior approach. The common peroneal nerve was identified near the biceps femoris tendon and traced to its superficial and deep divisions. Motor branches were followed to their points of entry into the target muscles. The location of each motor entry point was measured relative to prespecified tibial or fibular landmarks and normalized to total leg length measured from the knee joint line to the ankle joint line.
Sponsors
Research Inc
Study design
Observational model
OTHER
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Adult cadaveric specimen (age at death 18 years or older) * Fresh-frozen lower-limb specimen made available under institutional standards for cadaveric research * No prior trauma involving the selected lower limb * No prior surgical intervention involving the selected lower limb
Exclusion criteria
* Cadaveric specimen from an individual younger than 18 years at death * Prior trauma involving the lower limb * Prior surgical intervention involving the lower limb
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Mean proportional localization of motor nerve entry points by target muscle | Periprocedural, during the single standardized cadaveric dissection session for each specimen. 1 day | For each terminal motor branch, the distance from the prespecified proximal bony reference point to the point at which the branch entered the target muscle was measured. For tibial branches, the proximal reference was the posterior border of the tibia at the midpoint of the proximal epiphysis. For superficial and deep peroneal branches, the proximal reference was the most superior aspect of the fibular head on its anterior surface. Total leg length was measured from the knee joint line to the ankle joint line. The motor entry point was calculated as distance to the entry point divided by total leg length and expressed as a dimensionless proportion. For each target muscle, the mean, standard deviation, 68% probability interval (mean ±1 standard deviation), and 95% probability interval (mean ±2 standard deviations) were calculated. Target muscles included the medial and lateral gastrocnemius, soleus, flexor digitorum longus, flexor hallucis longus, tibialis posterior, fibularis/peroneus |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Number of motor branches identified by parent nerve and target muscle | Periprocedural, during the single standardized cadaveric dissection session for each specimen. 1 day | Count of terminal motor branches arising from the tibial, superficial peroneal, or deep peroneal nerve and entering each dissected target muscle. Results are reported as counts by parent nerve and target muscle. |
Countries
Colombia
Contacts
CONTACTMARIA F GARCIA RUEDA, MD, Orthopedist
PRINCIPAL_INVESTIGATORMaria F Garcia Rueda, MD, Orthopedist
Outcome results
None listed