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Classification of Functions of LCF


Version: 20240224

Introduction

On the biology, the common meaning of 'function' is that of role, effect, or transformation rule (1994MorenoA_Fern´andezJ). The function of ligamentum capitis femoris (LCF) is still unknown (2009LampertC) and the ligament itself continues to bewilder and fascinate orthopaedic surgeons (2020Rosinsky_DombBG). The largest collections of opinions on the function of the LCF are contained in our works (2004Архипов-БалтийскийСВ; 2018,2023АрхиповСВ). The classification of the function of the LCF necessary to determine the directions for further study of this structure, the choice of goals and methods for its surgical recovery. The reconstruction of the LCF without restoring specific functions to solve a clearly defined clinical and biomechanical problem is nothing more than a cosmetic procedure.

The proposed classification based on experimental and clinical studies of the author, as well as because of an analysis of literary sources. All the selected functions of the LCF divided into four types - physical, biochemical, biological and informational (Tables 1-4). We proposed to divide functions into hierarchical units similar to the elements of the systematics of living organisms: phylum, class, order, family, genus, and specie. Each function is marked with a color indicating the highest level of evidence as of the current date. The sequence of levels is located on the “confidence scale” from the highest mark - “axiom” to the lowest mark - “error” (Table 5). With further study of the LCF, we plan to expand on the above above functions and clarify the levels of evidence used.

References

Moreno A, Umerez, J, Fern´andez J. Definition of life and research program in artificial life. Ludus Vitalis. 1994;2(3)15–33.

Lampert C. Läsionen des lig. capitis femoris: pathologie und therapie. Arthroskopie. 2009;22(4)293–8.

Rosinsky PJ, Shapira J, Lall AC, Domb BG. All About the Ligamentum Teres: From Biomechanical Role to Surgical Reconstruction. J Am Acad Orthop Surg. 2020; 28(8)e328–e39.

Архипов-Балтийский С.В. Рассуждение о морфомеханике. Норма. T.2. Калининград, 2004. [In Russ.]

Архипов С.В. Биомеханика пингвинов: заметки к вопросу о причинах ковыляющей походки и перспективах ее ремоделирования…, Т.5. Королев, 2018. [In Russ.]

Архипов С.В. Связка головки бедренной кости: функция и роль в патогенезе коксартроза; 2-ое изд., испр. и доп. Йоэнсуу: Издание Автора, 2023. [In Russ.] 

Physical functions of the LCF (Table 1) 

Elastic forces functions

 

Static functions

 

Damping functions:

 

- for the pelvis

 

- for the femur

 

Protective function:

 

- for the transit vessels (arterial, venous, lymphatic)

 

- for the nerves (r. post. n. obtur. and other nerves)

 

Local compression functions:

 

... of the femoral head:

 

- the cartilaginous part

 

- the bony part

 

...of the acetabulum:

 

- the cartilaginous part (model of the acetabulum)

 

- the bony part (lunate surface)

 

Dislocation functions

 

Synovial fluid mixing function

 

Synovial fluid distribution function

 

Mesenchyme separation function

 

Reaction force functions (horizontal, vertical, tangential)

 

Dynamic functions

 

Functions of restriction (braking):

 

... translational movements

 

... of femur:

 

- on the cranial direction

 

- on the lateral direction

 

- on the medial direction

 

- forward

 

- back

 

of pelvis:

 

- on the caudal direction

 

- on the medial direction

 

- on the lateral direction

 

- forward

 

- back

 

... rotational movements

 

... of femur

 

on the horizontal plane:

 

- pronation

 

- supination

 

… on the frontal plane:

 

... adduction

 

... abduction

 

... of pelvis

 

on the horizontal plane:

 

- turn forward

 

- turn back

 

on the frontal plane:

 

- medial tilt

 

Motion correction functions:

 

... of pelvis:

 

- lateral tilt with turning forward

 

- lateral tilt with turning back

 

- medial tilt with leaning forward

 

- medial tilt with leaning back

 

- turn forward after turn back

 

- turn back after turn forward

 

- lateral displacement after subluxation

 

- lateral displacement with adduction, pronation and supination

 

... of femur:

 

- increased adduction with flexion

 

- increased adduction with extension

 

- increased abduction with pronation

 

- increased abduction with supination

 

- medial displacement with adduction, pronation, and supination

 

- medial displacement with initial lateralization

 

- increased lateral displacement with abduction and flexion

 

Biomechanical functions:

 

Converting a hip into an analog of third-class lever

 

Shunting of the load of the horizontal part of the iliofemoral ligament

 

Shunting of the load of the abductor muscle group

 

Reducing the load on the pronators and supinators while walking

 

Reducing the load on the pronators and supinators while running

 

Reducing the load on the flexors and extensors while walking

 

Reducing the load on the flexors and extensors while running

 

Ensuring rhythmic walking

 

Ensuring rhythmic running

 

Ensuring gait symmetry

 

Ensuring running symmetry

 

Ensuring minimal body sway while walking

 

Determination of the maximum speed of pelvic rotation while walking

 

Determination of the maximum speed of pelvic rotation while running

 

Determination of the amplitude of the inclination and rotation of the pelvis while walking

 

Determination of the amplitude of the inclination and rotation of the pelvis while running

 

Determination of the maximum frequency of pelvic rotation

 

Determining the maximum step frequency

 

Determination of the maximum frequency of shoulder girdle rotation while walking

 

Determining of the maximum frequency of hand fluctuations

 

Determination of the trajectory of movement of the common center of mass of the body

 

Determination of the acceleration of movement of the common center of mass of the body

 

Converting potential energy into kinetic energy while walking

 

Converting potential energy into kinetic energy while running

 

Anti-gravity dynamic functions:

 

Support pelvic and body while walking


Support pelvic and body while running

 

Reducing body weight while walking (lifting force generation)

 

Reducing the vertical component of the reaction force while walking

 

Reducing the transverse component of the reaction force while walking

 

Tribological functions:

 

Influence on friction coefficient

 

Influence on the reaction force of the femoral head

 

Static functions

 

Stabilization functions:

 

- of pelvis in one-support orthostatic position

 

- of pelvis in two-support asymmetrical orthostatic position

 

- of femoral head in the acetabulum:

 

- macrostabilization (antiluxation)

 

- microstabilization (antisubluxation)

 

Anti-gravity static functions (suspension):

 

- of pelvis in one-support orthostatic position

 

- of pelvis in two-support asymmetrical orthostatic position

 

- of femur with flexion-adduction-supination (legs crossed sitting pose)

 

Conducting functions (bridge, tunnel):

 

- for transit vessels (arterial, venous, lymphatic)

 

- for nerves (rr. post. n. obtur., rr. musc. n. fem., n. glut. inf. …)

 

Functions of the femoral head connection to the:


- fossa acetabulum

 

- incisura acetabulum

 

- ligamentum transversum

 

- periosteum of the pelvis

 

- membrana obturatoria

 

Tensorogenic functions:

 

Influences on the distribution and magnitude of internal forces (stresses) in the:

 

- femoral head (below «+»; above «-»)

 

- acetabulum (below «+»; above «-»)

 

- external ligaments and joint capsule (shunt)

 

- transverse ligament of the acetabulum (spraining)

 

- abductor muscle group (shunt)

 

Influences on the shape, size and position (deformation, displacement):

 

- of femoral head

 

- of femoral neck

 

- of acetabulum

 

- of hip bone

 

- of pelvis

 

- of lumbosacral spine

 

Biochemical functions of the LCF (Table 2)

Functions of regulation of synovial fluid properties:


- volume


- fluidity


- osmotic pressure


- viscosity


- surface tension


- wetting


- density


- temperature


- gas pressure


Producing functions:

 

Water excretion


Production of organic components


Production of inorganic components


Gas excretion


Excretion of atypical chemicals


Absorption function:

 

Water absorption


Absorption of organic components


Absorption of inorganic


Absorption of atypical chemical compounds (e.g. drugs)


Gas absorption


Dissolution functions:

 

Dissolution of inorganic substances (urates, calcium dihydropyrophosphate, hydroxyapatite)


Dissolution of organic substances (fibrinolysis, emulsification of bone marrow fat)


Gas dissolution


Deposition functions:

 

Crystallization of inorganic substances (urates, calcium dihydropyrophosphate)


Protein denaturation


Demulsification of fat


Biological functions of the LCF (Table 3)

Adaptation functions:


Synovial fluid volume regulation


Synovial fluid composition regulation


Hip joint temperature regulation


Hip joint pressure regulation


Involvement in immune processes


Maintaining one-support orthostatic position and two-support asymmetrical orthostatic position


Device for locomotion


Resource allocation functions:


Power distribution


Material distribution


Synthetic functions:


Cytopoietic function (synoviocytes, histiocytes, lymphocytes, neutrophils, monocytes)


The formation of chondromic bodies (synovial chondromatosis)


The formation of synovial cysts


Sanitation functions (synovial fluid sanitation):


Destruction function (cells, fibers, bacteria, tissue detritus, pus, blood clots, bone, cartilage fragments)


Extraction function (removal of degradation products)


Hormonal functions of adipose tissue:


Hormone synthesis (leptin, angiotensin, estrogen, resistin, adipsin, adiponectin)


Enzyme synthesis (plasminogen, liporotein lipase)


Peptide synthetsis (cytokines, eicosanides)


Remodeling functions:


Synovial fluid remodeling


Remodeling of adipose tissue of the acetabulum


Remodeling of the ligamentous apparatus


Articular cartilage remodeling


Acetabular labral remodeling


Bone remodeling


Tendon remodeling of abductor muscles


Remodeling muscle tissue of abductor muscles


Shape-forming functions (morphogenesis, transformation):


The formation of the external ligaments of the hip joint


The formation of cartilage (labrum acetabulum, femoral head, cartilage model of the acetabulum)


The formation of hip bone and femur


The formation of adjacent joints (pubic symphysis, sacroiliac joint, knee)


The formation of the parts of the skeleton (pelvis, spine)


Trophic functions:


Cartilage nutrition


Blood supply of the femoral head


Transport functions:


Tissue transport


Blood circulation


Lymphatic circulation


Information functions of the LCF  (Table 4)

Conductive functions:


Afferent function


Efferent function


Receptor functions:


Mechanoreceptor functions:


Baroreceptor function


Vibroreceptor function


Tensoreceptor function


Thermoreceptor functions:


Cold-sensitive function


Heat-sensitive function


Chemoreceptor function


Sensitive functions:


Kinesthesia


Proprioception


Nociception


Immuno-information functions:


Cellular immune function


Humoral immune functions


Trigger function


Metronome function


Levels of evidence of functions of the LCF with their conventional names and symbols (Table 5)

Color and number designations of evidence levels

Names of evidence levels

1

Axiom

2

Research

3

Experiment

4

Observation

5

Calculation

6

Figure

7

Publication

8

Hypothesis

9

Error


Keywords 

ligamentum capitis femoris, ligamentum teres, ligament of head of femur, role, function, hip joint, biomechanics



                                                                   


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