Laurie,
I am sorry. I know you are super busy but I also know you have a mind like a steel trap. I am looking for the papers or citations to give to a surgeon explaining why he should leave in the CCL even when it is completely torn because it has proprioceptive fibers. (that’s is correct, right?). He said there are still speakers running around saying that you need to take out the entire CCL because it will cause OA. What can I give him to show this? I know I have these papers on my computer but can’t find them right now. Do you know them off the top of your head. If not, no worries, I can look further.
thanks
E.
Debriding the CCL remnants
Re: Debriding the CCL remnants
This is fast and requires very little planning and committing on my part!
And I’m a pack rat for stuff like this…
I searched the topic back in the 2004 it seems. Two compilations are attached here.
Anyhoo! I hope these help. I’ve not done a more recent search! (maybe that should be a blog topic! hmmm)
Cheers,
Laurie
____
1: Acta Orthop Scand. 2002 Jun;73(3):330-4.
Mechanoreceptors in the anterior cruciate ligament contribute to the joint
position sense.
Adachi N, Ochi M, Uchio Y, Iwasa J, Ryoke K, Kuriwaka M.
Department of Orthopaedic Surgery, Shimane Medical University, Izumo, Japan.
We have investigated the correlation between the number of mechanoreceptors in
anterior cruciate ligament (ACL) remnants and the joint position sense just
before an ACL reconstruction in 29 patients. The number of mechanoreceptors was
evaluated histologically, using the Gairns gold chloride method.
Mechanoreceptors were also found in patients who had a long interval between
injury and the operation. A joint position sense test was done within 3 days
before surgery. We found a positive correlation between the number of
mechanoreceptors and accuracy of the joint position sense, suggesting that
proprioceptive function of the ACL is related to the number of mechanoreceptors.
Therefore, we should consider preserving ACL remnants during ACL reconstruction.
PMID: 12143983 [PubMed - indexed for MEDLINE]
2: Int Orthop. 2000;24(5):272-5.
Quantification of mechanoreceptors in the canine anterior cruciate ligament.
Arcand MA, Rhalmi S, Rivard CH.
Oklahoma Orthopedics Inc, 900 North Porter Suite 100B, Norman Oklahoma, 73071,
USA. marcand@ilinkusa.net
Ten canine anterior cruciate ligaments (ACLs) were harvested while preserving
their bony attachments. Specimens were stained using a modified gold chloride
technique, divided into thirds, and serially sliced at 0.5 microns. The slides
were viewed to count the mechanoreceptors present. The average numbers of
receptors found were: proximal 67, middle 43, and distal 18 (ANOVA: P < 0.001).
The statistical test (Sheffe) revealed that the proximal third contained a
greater mean number of receptors (S = 3.8). No significant difference was found
between the number of receptors in the middle and distal thirds (S = 0.85).
PMID: 11153457 [PubMed - indexed for MEDLINE]
3: Arch Orthop Trauma Surg. 1998;118(3):159-63.
Proprioception of the cruciate ligaments: receptor mapping in an animal model.
Raunest J, Sager M, Burgener E.
Department of General Surgery and Traumatology, Heinrich Heine University,
Dusseldorf, Germany.
Ten anterior and posterior cruciate ligaments (ACL and PCL) harvested from adult
sheep were investigated under light microscopy for data on the frequency and
localisation of neural structures. Serial sections of 25 microns thickness were
stained with a modified gold chloride technique. Receptors were classified
according to their histological structure. Topographic distribution and
frequency within the ligament texture were determined with the help of
computerized image analysis. Three distinct neural structures could be
identified: Ruffini endings, Ruffini corpuscles of the Golgi tendon organ-like
type and Pacinian corpuscles. Golgi tendon organs were not found. In total, 274
and 238 neural structures were present in the 10 ACL and 10 PCL, respectively.
Pacinian receptors were the most common structures, with a mean frequency of
13.6 +/- 5.3 (ACL) and 12.4 +/- 5.1 (PCL), followed by Ruffini endings with 8.9
+/- 3.2 (ACL) and 7.8 +/- 2.9 (PCL), whereas Ruffini corpuscles had the lowest
frequency with a mean value of 4.9 +/- 2.1 (ACL) and 3.4 +/- 1.1 (PCL). The
majority of the neural structures were located in the subsynovial sheath or
closely associated with endotenon structures. The tibial and femoral insertion
areas had a significantly increased receptor density compared with the midpart
of the ACL and PCL (P < 0.001), where only 19.3% and 23.7% of the receptors were
located. These results emphasise the complex sensory structure of the cruciate
ligaments and provide a valid morphological basis for further neurophysiological
investigations.
PMID: 9932192 [PubMed - indexed for MEDLINE]
4: Acta Orthop Scand. 1997 Dec;68(6):559-62.
Mechanoreceptors of patellar tendon used for ACL reconstruction. Rabbit
experiments.
Wada Y, Takahashi T, Michinaka Y, Morisawa Y, Yamamoto H.
Department of Orthopedics, Kochi Medical School, Japan.
In 17 Japanese white rabbits (weighing 2.6-3.7 kg), the anterior cruciate
ligament of the right knee was resected and then reconstructed, using the
lateral half of the patellar tendon. The contralateral side served as control.
Rabbits were killed 10, 20, or 30 weeks postoperatively. Then the reconstructed
ligament was harvested and stained, using a modified gold chloride method. Under
the light microscope, sensory nerve endings in serial sections were counted
after being morphologically identified. With respect to the number of Pacinian
and Ruffini corpuscles, there were no significant differences between the
reconstructed ligament and the control patellar tendon at any time after
surgery.
PMID: 9462356 [PubMed - indexed for MEDLINE]
5: J Anat. 1995 Oct;187 ( Pt 2):353-9.
Characterisation of the neurosensory elements of the feline cranial cruciate
ligament.
Koch B, Kurriger G, Brand RA.
Department of Orthopedic Surgery, University of Iowa, Iowa City 52242, USA.
The identification and distribution of mechanoreceptors in the cranial cruciate
ligament of the cat (analogous to the anterior cruciate ligament in other
species) was studied histologically using a modified celloidin embedding
technique to achieve serial sectioning of bone-ligament-bone preparations with
gold chloride staining. We identified distinctive large elongated structures
situated between the collagen bundles of the ligament (resembling endings
described as Freeman and Wyke type III; also termed Golgi tendon receptors).
These endings were found near the middle of the ligament well away from the
bone-ligament junction. Axons seen entering only one end of each type III ending
helped to confirm its neural basis. While we saw structures resembling types I
and II endings (i.e. Ruffini and pacinian endings, respectively) in individual
sections, serial sections failed to reveal convincing evidence of their
existence. Such structures almost always appeared to be vascular in nature on
adjacent sections, with vessels entering and exiting. We conclude that serial
sections are critical to interpreting the presence or absence of
mechanoreceptors.
PMID: 7591998 [PubMed - indexed for MEDLINE]
6: Clin Orthop. 1994 Nov;(308):29-32.
Anterior cruciate ligament mechanoreceptors. Histologic studies on lesions and
reconstruction.
Denti M, Monteleone M, Berardi A, Panni AS.
2nd Department of Orthopaedics, University of Milan, San Gerardo Hospital,
Monza, Italy.
The fate of mechanoreceptors was studied in torn and reconstructed anterior
cruciate ligaments in animals and in humans. In untreated anterior cruciate
ligament lesions in humans, morphologically normal mechanoreceptors remained in
the ligament for 3 months after the injury. After that time, their number
gradually decreased. By the 9th postinjury month, only a few free nerve endings
were present. Even free nerve endings were totally absent in the biopsy
specimens from 1-year-old lesions. In experimental animals, anterior cruciate
ligament reconstruction with autologous patellar tendon resulted in the presence
of mechanoreceptors in the reconstructed anterior cruciate ligament. When an
artificial ligament was used, no mechanoreceptors were found. Morphologically
normal mechanoreceptors were present in 2 patients with a lax biologic anterior
cruciate ligament reconstruction 9 and 10 years after the operation.
PMID: 7955696 [PubMed - indexed for MEDLINE]
7: Knee Surg Sports Traumatol Arthrosc. 1994;2(2):118-22.
Nerve supply of anterior cruciate ligaments and of cryopreserved anterior
cruciate ligament allografts: a new method for the differentiation of the
nervous tissues.
Fromm B, Kummer W.
Department of Orthopaedics, University Hospital, University of Heidelberg,
Germany.
We investigated the nerve supply of anterior cruciate ligaments ((ACLs) and of
cryopreserved bone-ACL-bone allografts in a rabbit model with
immunohistochemical methods to establish the distribution pattern of the nervous
tissues and to determine the reinnervation rate of ACL allografts. The ACL is
innervated by three different classes of nerve fibre: (1) fibres of large
diameter, characterized by neurofilament immunoreactivity, which are
fast-conducting mechanoreceptive sensory afferents; (2) fibres of small
diameter, characterized by substance P-immunoreactivity, which are
slow-conducting nociceptive sensory afferents; and (3) sympathetic efferent
vasomotor fibres, characterized by their immunoreactivity to the rate-limiting
enzyme of noradrenaline synthesis, tyrosine hydroxylase. The ACLs showed
numerous fibres of all three nerve classes; as specialised sensory nerve endings
only Ruffini corpuscles were observed. All nerve fibres were located
subsynovially, none within the collagen core of the ligament itself. No nerve
fibres were detected in the ACL allografts at 3 and 6 weeks. Sparse fibres were
detected at 12 weeks, while the 24-, 36- and 52-week specimens showed plenty of
all three fibre types. No mechanoreceptors were found in the ACL allografts. To
our knowledge, this method for the first time allows a differentiation of the
nerve fibres of ACLs and ACL allografts into three different nerve fibre classes
with known neurophysiological functions.
PMID: 7584184 [PubMed - indexed for MEDLINE]
8: Am J Sports Med. 1992 Jul-Aug;20(4):430-3.
Occurrence of free nerve endings in the soft tissue of the knee joint. A
histologic investigation.
Biedert RM, Stauffer E, Friederich NF.
Sports Traumatology Research Institute, Magglingen, Switzerland.
We present a comprehensive histologic study of neurologic structures in 18
static and dynamic knee structures of 8 cadaveric knees. Qualitative and
quantitative measurements of the incidence of free nerve endings in the
structures were recorded. The highest amounts of afferent nerve fibers type IVa
were found in the retinacula, the patellar ligament, the pes anserinus, and in
the ligaments of Wrisberg and Humphry; the lowest amount was found in the
anterior cruciate ligament. There is a positive correlation between the number
of mechanoreceptors per standardized area unit and the clinical presentation of
certain knee disorders.
PMID: 1415886 [PubMed - indexed for MEDLINE]
9: Anat Histol Embryol. 1992 Mar;21(1):1-8.
Innervation of the canine cruciate ligaments. A neurohistological study.
Yahia LH, Newman NM, St-Georges M.
Biomedical Engineering Institute, Ecole Polytechnique/Faculty of Medicine,
Campus de l'Universite de Montreal, Quebec, Canada.
A search for mechanoreceptors within the substance of the cruciate ligaments was
undertaken using the modified gold-chloride technique. Abundant Pacinian,
Vater-Pacini, Ruffini end organs and Ruffini-type receptors were found within
the substance of the anterior and posterior cruciates. The receptors were
innervated by axons of 5 to 10 micrometers in diameter penetrating from the
synovium investing the ligaments. The findings support the contention that the
cruciate ligaments have important mechanoreceptive and proprioceptive functions.
PMID: 1585987 [PubMed - indexed for MEDLINE]
10: J Bone Joint Surg Am. 1992 Mar;74(3):390-7.
Sensory innervation of the anterior cruciate ligament. An electrophysiological
study of the response properties of single identified mechanoreceptors in the
cat.
Krauspe R, Schmidt M, Schaible HG.
Physiologisches Institut, Universitat Wurzburg, Germany.
In anesthetized cats, electrophysiological recordings were made from twenty-six
single thick myelinated afferent fibers of the posterior articular nerve of the
knee joint that had sensory endings in the anterior cruciate ligament. Most
afferent fibers arising from the anterior cruciate ligament were activated by
application of local pressure to discrete sites of the ligament, near the
attachment to the femur. Afferent fibers from the anterior cruciate ligament did
not fire when the knee was in the resting position at 30 degrees of flexion, but
they were activated when the knee joint was extended and flexed and externally
or internally rotated. Whereas responses were induced by movements in the
working range of motion of the knee, activity was markedly increased when the
joint was hyperextended and externally or internally rotated. These findings
suggest that mechanoreceptors with myelinated axons provide information about
tension of the anterior cruciate ligament.
PMID: 1548266 [PubMed - indexed for MEDLINE]
11: Clin Orthop. 1991 Jul;(268):161-78.
A sensory role for the cruciate ligaments.
Johansson H, Sjolander P, Sojka P.
Department of Physiology, University of Umea, Sweden.
Morphologic, physiologic, and clinical evidence for the sensory role of the
cruciate ligaments is reviewed. The cruciate ligaments accommodate
morphologically different sensory nerve endings (Ruffini endings, Pacinian
corpuscles, Golgi tendon organlike endings, and free nerve endings) with
different capabilities of providing the central nervous system with information
not only about noxious and chemical events but also about characteristics of
movements and position-related stretches of these ligaments. A survey of
available data reveals that low threshold joint-ligament receptor (i.e.,
mechanoreceptor) afferents evoke only weak and rare effects in skeletomotor
neurons (alpha-motor neurons), while they frequently and powerfully influence
fusimotor neurons (gamma-motor neurons). The effects on the gamma-muscle-spindle
system in the muscles around the knee are so potent that even stretches of the
cruciate ligaments at relatively moderate loads (not noxious) may induce major
changes in responses of the muscle spindle afferents. As the activity in the
primary muscle spindle afferents modifies the stiffness in the muscles, the
cruciate ligament receptors, via the gamma-muscle-spindle system, may
participate in the regulation and preprogramming of the muscular stiffness
around the knee joint and thereby of the knee joint stiffness. Thus, the sensory
system of the cruciate ligaments is able to significantly contribute to the
functional stability of the knee joint.
Publication Types:
Review
Review, Academic
PMID: 2060205 [PubMed - indexed for MEDLINE]
12: Acta Anat (Basel). 1991;141(1):8-14.
Intrinsic innervation of the rat knee joint articular capsule and ligaments.
Marinozzi G, Ferrante F, Gaudio E, Ricci A, Amenta F.
Istituto Superiore di Educazione Fisica Statale (ISEF), Roma, Italia.
In spite of the practical importance of having a detailed knowledge of knee
joint innervation to understand the pathophysiologic aspects, little information
is now available concerning the density and pattern of the nerve fibres which
are distributed to it. The present study has been designed to investigate the
density and distribution of nerve fibres and receptor corpuscles in the knee
joint articular capsule, cruciate and collateral ligaments in the rat, using the
acetylcholinesterase (AChE) histochemical in toto staining technique. The
investigation was performed on male Wistar rats of 3 months of age, some of
which had been treated with capsaicin to deplete their afferent 'C' fibres of
their content of neuropeptides. AChE-positive nerve fibres and different types
of receptor corpuscle endings were found within articular capsule and ligaments.
The highest density of AChE-positive nerve fibres was noticeable in the fibular
collateral ligament followed by the tibial collateral ligament, the posterior
cruciate ligament, the anterior cruciate ligament and the articular capsule. In
the articular capsule the number of type I endings was higher than in the
ligaments. The opposite is true for the other type of receptor corpuscles found
as well as for nerve endings. Capsaicin treatment significantly reduced the
density of AChE-positive nerve fibres in knee joint ligaments but did not affect
nerve fibres in the articular capsule. Moreover, it caused the disappearance of
some kind of receptor corpuscles within the collateral and cruciate ligaments.
The above data collectively suggest that the AChE in toto staining technique may
represent a good method for investigating joint innervation and that a
significant percentage of nerve fibres supplying knee joint ligaments is
represented by C fibre afferents.
PMID: 1950424 [PubMed - indexed for MEDLINE]
13: Anat Anz. 1991;173(4):233-8.
Mechanoreceptors in the canine anterior cruciate ligaments.
Yahia LH, Newman N.
Ecole Polytechnique/Faculty of Medicine Montreal, Department of Orthopaedics,
Hotel-Dieu Hospital, Montreal, Canada.
Canine anterior cruciate ligaments were sectioned into sagittal, frontal and
horizontal segments which were stained in bulk using a modified gold chloride
method. Segments were then serially sectioned on a sliding microtome at 100
micron, mounted on slides, dehydrated and coverslipped. Abundant Ruffini and
pacinian receptors were identified within the substance of the ligament. These
receptors were innervated by 5 to 10 micron diameter axons penetrating from the
peripheral synovium investing the ligament. The anterior cruciate ligament is
capable of afferent input to the central nervous system of importance to the
biomechanical function of the knee joint.
PMID: 1803948 [PubMed - indexed for MEDLINE]
14: Neurosci Lett. 1989 Jul 17;102(1):33-8.
Sensory nerve endings in the cat cruciate ligaments: a morphological
investigation.
Sjolander P, Johansson H, Sojka P, Rehnholm A.
Department of Physiology, University of Umea, Sweden.
The histology of the cat anterior and posterior cruciate ligaments was studied
using the modified Gairns gold chloride staining for neural elements. Ruffini
endings, Pacinian corpuscles, Golgi tendon organ-like endings and free nerve
endings were identified. All receptor types were most frequently found close to
the tibial and femoral insertions. The results are consistent with our earlier
findings that small increases in the tension of the ligaments can potently
influence the fusimotor system to the muscles acting at the knee joint, and
thereby participate in the regulation of their stiffness and the knee joint
stability.
PMID: 2779842 [PubMed - indexed for MEDLINE]
15: Am J Anat. 1988 May;182(1):16-32.
Mechanoreceptors in articular tissues.
Zimny ML.
Department of Anatomy, Louisiana State University Medical Center, New Orleans
70112-1393.
The morphology, distribution, and function of mechanoreceptors in joint
capsules, ligaments, knee-joint menisci, and articular disks of the
temporomandibular joints of animals, including humans, have been reviewed. In
addition to free nerve endings, three types of joint receptors are present in
most animal joints: 1) a Ruffini-like receptor situated in the capsule, 2) a
Golgi tendon organ situated in a ligament; and 3) the encapsulated Pacinian-like
corpuscle. In the anterior cruciate ligament, nerve fibers enter from the
subsynovial connective tissue and terminate in receptors. Most of the receptors
are found in the distal portion of the ligament. In the meniscus, nerves
penetrate the outer and middle one-third of the body and the horns from the
perimeniscal tissue, with a greater concentration at the horns. In the
temporomandibular articular disk, the mechanoreceptor density is greatest at the
periphery and progressively decreases toward the center. If a joint has an
intra-articular structure, mechanoreceptors undoubtedly are present within it.
The concentration of mechanoreceptors appears greater in areas related to the
extremes of movement and probably represents the first line of defense in
sensing these extremes. These afferent discharges elicit support from
discharging mechanoreceptors located in the joint capsule and subsequently from
those in the surrounding muscles. This total afferent output alerts the central
nervous system of impending injury, which can then be averted through reflex
mechanisms.
Publication Types:
Review
Review, Tutorial
PMID: 3291597 [PubMed - indexed for MEDLINE]
16: J Bone Joint Surg Am. 1987 Feb;69(2):243-7.
Neural anatomy of the human anterior cruciate ligament.
Schutte MJ, Dabezies EJ, Zimny ML, Happel LT.
The histology of the anterior cruciate ligament was studied by a modified
technique of the Gairns gold chloride stain for neural elements. Three
morphological types of mechanoreceptors and free nerve-endings were identified:
two of the slow-adapting Ruffini type and the third, a rapidly adapting Pacinian
corpuscle. Rapidly adapting receptors signal motion and slow-adapting receptors
subserve speed and acceleration. Free nerve-endings, which are responsible for
pain, were also identified within the ligament. These neural elements comprise 1
per cent of the area of the anterior cruciate ligament.
PMID: 3805085 [PubMed - indexed for MEDLINE]
17: Nippon Seikeigeka Gakkai Zasshi. 1986 Dec;60(12):1283-92.
An autoradiographic study of the distribution of sensory nerve endings in the
knee joint of the rat.
Kanatani Y, Hirohata K, Umetani T.
The distribution of sensory nerve endings of the knee joint in rats has been
investigated by autoradiography of 3H-leucine. Sections were made and each
section was examined by autoradiography and silver impregnation staining. Free
nerve endings were found only in the synovial membrane, the menisci and their
synovial junction. In the joint capsule, capsulated sensory nerve endings were
sparsely distributed. Numerous sensory nerve endings were found at the insertion
of the patellar ligament, the collateral ligament and the cruciate ligament.
These resembling Golgi-Mazzoni nerve endings or capsulated sensory nerve endings
are thought to be proprioceptors. Radioactivity, which would indicate the
presence of sensory nerve endings, was not recognized in the osseous tissue. It
is hypothesized that proprioceptor at the insertion of ligaments plays an
important role as monitor of joint motion by the reflex pathway.
PMID: 3572134 [PubMed - indexed for MEDLINE]
18: Anat Rec. 1986 Feb;214(2):204-9.
Mechanoreceptors in the human anterior cruciate ligament.
Zimny ML, Schutte M, Dabezies E.
This study was undertaken to identify and quantitate mechanoreceptors in the
human anterior cruciate ligament (ACL). Ligaments from six human subjects were
obtained at autopsy, cut into cross-sectional segments 1.0-1.5 cm thick, and
kept oriented as to the femoral and tibial attachments. The segments were
stained in bulk by using a modified gold chloride method, frozen, and sectioned
on a sliding microtome at 100 microns. The sections were floated in alcoholic
gelatin, mounted on slides, dehydrated, and coverslipped. Serial sections were
studied with the light microscope and receptors were photographed.
Cross-sectional maps of every tenth section were made outlining the periphery of
the ACL and the receptors within that section. With these maps, a computerized,
morphometric analysis of the ACL was done, thus obtaining the percentage of
receptors in each section and in each ACL. In addition to free nerve endings,
two morphologically distinct mechanoreceptors were identified: (1) Ruffini end
organs and (2) Pacinian corpuscles. Preliminary morphometric analyses show that
populations of mechanoreceptors are greater at the femoral and tibial ends of
the ligament and constitute approximately 2.5% of the ligament. Based on these
findings the human ACL has the anatomic basis for a discriminating afferent
outflow to the central nervous system.
PMID: 3954077 [PubMed - indexed for MEDLINE]
19: J Bone Joint Surg Am. 1984 Sep;66(7):1072-6.
Mechanoreceptors in human cruciate ligaments. A histological study.
Schultz RA, Miller DC, Kerr CS, Micheli L.
We obtained human cruciate ligaments at the time of total knee replacement and
from autopsy and amputation specimens, and examined histological sections of the
ligaments for the presence of mechanoreceptors using the Bodian, Bielschowsky,
and Ranvier gold-chloride stains for axons and nerve-endings. The cruciate
ligaments obtained at the time of total knee replacement were too distorted by
disease processes to be of use. The autopsy and amputation specimens, however,
contained fusiform mechanoreceptor structures measuring 200 by seventy-five
micrometers, with a single axon exiting from the capsule of the receptor. One to
three receptors were found at the surface of each ligament beneath the synovial
membrane, and were absent from the joint capsules and menisci. Morphologically
the receptors resembled Golgi tendon organs, and it seems likely that they
provide proprioceptive information and contribute to reflexes inhibiting
injurious movements of the knee. This is the first histological demonstration of
mechanoreceptors in human cruciate ligaments.
PMID: 6207177 [PubMed - indexed for MEDLINE]
And I’m a pack rat for stuff like this…
I searched the topic back in the 2004 it seems. Two compilations are attached here.
Anyhoo! I hope these help. I’ve not done a more recent search! (maybe that should be a blog topic! hmmm)
Cheers,
Laurie
____
1: Acta Orthop Scand. 2002 Jun;73(3):330-4.
Mechanoreceptors in the anterior cruciate ligament contribute to the joint
position sense.
Adachi N, Ochi M, Uchio Y, Iwasa J, Ryoke K, Kuriwaka M.
Department of Orthopaedic Surgery, Shimane Medical University, Izumo, Japan.
We have investigated the correlation between the number of mechanoreceptors in
anterior cruciate ligament (ACL) remnants and the joint position sense just
before an ACL reconstruction in 29 patients. The number of mechanoreceptors was
evaluated histologically, using the Gairns gold chloride method.
Mechanoreceptors were also found in patients who had a long interval between
injury and the operation. A joint position sense test was done within 3 days
before surgery. We found a positive correlation between the number of
mechanoreceptors and accuracy of the joint position sense, suggesting that
proprioceptive function of the ACL is related to the number of mechanoreceptors.
Therefore, we should consider preserving ACL remnants during ACL reconstruction.
PMID: 12143983 [PubMed - indexed for MEDLINE]
2: Int Orthop. 2000;24(5):272-5.
Quantification of mechanoreceptors in the canine anterior cruciate ligament.
Arcand MA, Rhalmi S, Rivard CH.
Oklahoma Orthopedics Inc, 900 North Porter Suite 100B, Norman Oklahoma, 73071,
USA. marcand@ilinkusa.net
Ten canine anterior cruciate ligaments (ACLs) were harvested while preserving
their bony attachments. Specimens were stained using a modified gold chloride
technique, divided into thirds, and serially sliced at 0.5 microns. The slides
were viewed to count the mechanoreceptors present. The average numbers of
receptors found were: proximal 67, middle 43, and distal 18 (ANOVA: P < 0.001).
The statistical test (Sheffe) revealed that the proximal third contained a
greater mean number of receptors (S = 3.8). No significant difference was found
between the number of receptors in the middle and distal thirds (S = 0.85).
PMID: 11153457 [PubMed - indexed for MEDLINE]
3: Arch Orthop Trauma Surg. 1998;118(3):159-63.
Proprioception of the cruciate ligaments: receptor mapping in an animal model.
Raunest J, Sager M, Burgener E.
Department of General Surgery and Traumatology, Heinrich Heine University,
Dusseldorf, Germany.
Ten anterior and posterior cruciate ligaments (ACL and PCL) harvested from adult
sheep were investigated under light microscopy for data on the frequency and
localisation of neural structures. Serial sections of 25 microns thickness were
stained with a modified gold chloride technique. Receptors were classified
according to their histological structure. Topographic distribution and
frequency within the ligament texture were determined with the help of
computerized image analysis. Three distinct neural structures could be
identified: Ruffini endings, Ruffini corpuscles of the Golgi tendon organ-like
type and Pacinian corpuscles. Golgi tendon organs were not found. In total, 274
and 238 neural structures were present in the 10 ACL and 10 PCL, respectively.
Pacinian receptors were the most common structures, with a mean frequency of
13.6 +/- 5.3 (ACL) and 12.4 +/- 5.1 (PCL), followed by Ruffini endings with 8.9
+/- 3.2 (ACL) and 7.8 +/- 2.9 (PCL), whereas Ruffini corpuscles had the lowest
frequency with a mean value of 4.9 +/- 2.1 (ACL) and 3.4 +/- 1.1 (PCL). The
majority of the neural structures were located in the subsynovial sheath or
closely associated with endotenon structures. The tibial and femoral insertion
areas had a significantly increased receptor density compared with the midpart
of the ACL and PCL (P < 0.001), where only 19.3% and 23.7% of the receptors were
located. These results emphasise the complex sensory structure of the cruciate
ligaments and provide a valid morphological basis for further neurophysiological
investigations.
PMID: 9932192 [PubMed - indexed for MEDLINE]
4: Acta Orthop Scand. 1997 Dec;68(6):559-62.
Mechanoreceptors of patellar tendon used for ACL reconstruction. Rabbit
experiments.
Wada Y, Takahashi T, Michinaka Y, Morisawa Y, Yamamoto H.
Department of Orthopedics, Kochi Medical School, Japan.
In 17 Japanese white rabbits (weighing 2.6-3.7 kg), the anterior cruciate
ligament of the right knee was resected and then reconstructed, using the
lateral half of the patellar tendon. The contralateral side served as control.
Rabbits were killed 10, 20, or 30 weeks postoperatively. Then the reconstructed
ligament was harvested and stained, using a modified gold chloride method. Under
the light microscope, sensory nerve endings in serial sections were counted
after being morphologically identified. With respect to the number of Pacinian
and Ruffini corpuscles, there were no significant differences between the
reconstructed ligament and the control patellar tendon at any time after
surgery.
PMID: 9462356 [PubMed - indexed for MEDLINE]
5: J Anat. 1995 Oct;187 ( Pt 2):353-9.
Characterisation of the neurosensory elements of the feline cranial cruciate
ligament.
Koch B, Kurriger G, Brand RA.
Department of Orthopedic Surgery, University of Iowa, Iowa City 52242, USA.
The identification and distribution of mechanoreceptors in the cranial cruciate
ligament of the cat (analogous to the anterior cruciate ligament in other
species) was studied histologically using a modified celloidin embedding
technique to achieve serial sectioning of bone-ligament-bone preparations with
gold chloride staining. We identified distinctive large elongated structures
situated between the collagen bundles of the ligament (resembling endings
described as Freeman and Wyke type III; also termed Golgi tendon receptors).
These endings were found near the middle of the ligament well away from the
bone-ligament junction. Axons seen entering only one end of each type III ending
helped to confirm its neural basis. While we saw structures resembling types I
and II endings (i.e. Ruffini and pacinian endings, respectively) in individual
sections, serial sections failed to reveal convincing evidence of their
existence. Such structures almost always appeared to be vascular in nature on
adjacent sections, with vessels entering and exiting. We conclude that serial
sections are critical to interpreting the presence or absence of
mechanoreceptors.
PMID: 7591998 [PubMed - indexed for MEDLINE]
6: Clin Orthop. 1994 Nov;(308):29-32.
Anterior cruciate ligament mechanoreceptors. Histologic studies on lesions and
reconstruction.
Denti M, Monteleone M, Berardi A, Panni AS.
2nd Department of Orthopaedics, University of Milan, San Gerardo Hospital,
Monza, Italy.
The fate of mechanoreceptors was studied in torn and reconstructed anterior
cruciate ligaments in animals and in humans. In untreated anterior cruciate
ligament lesions in humans, morphologically normal mechanoreceptors remained in
the ligament for 3 months after the injury. After that time, their number
gradually decreased. By the 9th postinjury month, only a few free nerve endings
were present. Even free nerve endings were totally absent in the biopsy
specimens from 1-year-old lesions. In experimental animals, anterior cruciate
ligament reconstruction with autologous patellar tendon resulted in the presence
of mechanoreceptors in the reconstructed anterior cruciate ligament. When an
artificial ligament was used, no mechanoreceptors were found. Morphologically
normal mechanoreceptors were present in 2 patients with a lax biologic anterior
cruciate ligament reconstruction 9 and 10 years after the operation.
PMID: 7955696 [PubMed - indexed for MEDLINE]
7: Knee Surg Sports Traumatol Arthrosc. 1994;2(2):118-22.
Nerve supply of anterior cruciate ligaments and of cryopreserved anterior
cruciate ligament allografts: a new method for the differentiation of the
nervous tissues.
Fromm B, Kummer W.
Department of Orthopaedics, University Hospital, University of Heidelberg,
Germany.
We investigated the nerve supply of anterior cruciate ligaments ((ACLs) and of
cryopreserved bone-ACL-bone allografts in a rabbit model with
immunohistochemical methods to establish the distribution pattern of the nervous
tissues and to determine the reinnervation rate of ACL allografts. The ACL is
innervated by three different classes of nerve fibre: (1) fibres of large
diameter, characterized by neurofilament immunoreactivity, which are
fast-conducting mechanoreceptive sensory afferents; (2) fibres of small
diameter, characterized by substance P-immunoreactivity, which are
slow-conducting nociceptive sensory afferents; and (3) sympathetic efferent
vasomotor fibres, characterized by their immunoreactivity to the rate-limiting
enzyme of noradrenaline synthesis, tyrosine hydroxylase. The ACLs showed
numerous fibres of all three nerve classes; as specialised sensory nerve endings
only Ruffini corpuscles were observed. All nerve fibres were located
subsynovially, none within the collagen core of the ligament itself. No nerve
fibres were detected in the ACL allografts at 3 and 6 weeks. Sparse fibres were
detected at 12 weeks, while the 24-, 36- and 52-week specimens showed plenty of
all three fibre types. No mechanoreceptors were found in the ACL allografts. To
our knowledge, this method for the first time allows a differentiation of the
nerve fibres of ACLs and ACL allografts into three different nerve fibre classes
with known neurophysiological functions.
PMID: 7584184 [PubMed - indexed for MEDLINE]
8: Am J Sports Med. 1992 Jul-Aug;20(4):430-3.
Occurrence of free nerve endings in the soft tissue of the knee joint. A
histologic investigation.
Biedert RM, Stauffer E, Friederich NF.
Sports Traumatology Research Institute, Magglingen, Switzerland.
We present a comprehensive histologic study of neurologic structures in 18
static and dynamic knee structures of 8 cadaveric knees. Qualitative and
quantitative measurements of the incidence of free nerve endings in the
structures were recorded. The highest amounts of afferent nerve fibers type IVa
were found in the retinacula, the patellar ligament, the pes anserinus, and in
the ligaments of Wrisberg and Humphry; the lowest amount was found in the
anterior cruciate ligament. There is a positive correlation between the number
of mechanoreceptors per standardized area unit and the clinical presentation of
certain knee disorders.
PMID: 1415886 [PubMed - indexed for MEDLINE]
9: Anat Histol Embryol. 1992 Mar;21(1):1-8.
Innervation of the canine cruciate ligaments. A neurohistological study.
Yahia LH, Newman NM, St-Georges M.
Biomedical Engineering Institute, Ecole Polytechnique/Faculty of Medicine,
Campus de l'Universite de Montreal, Quebec, Canada.
A search for mechanoreceptors within the substance of the cruciate ligaments was
undertaken using the modified gold-chloride technique. Abundant Pacinian,
Vater-Pacini, Ruffini end organs and Ruffini-type receptors were found within
the substance of the anterior and posterior cruciates. The receptors were
innervated by axons of 5 to 10 micrometers in diameter penetrating from the
synovium investing the ligaments. The findings support the contention that the
cruciate ligaments have important mechanoreceptive and proprioceptive functions.
PMID: 1585987 [PubMed - indexed for MEDLINE]
10: J Bone Joint Surg Am. 1992 Mar;74(3):390-7.
Sensory innervation of the anterior cruciate ligament. An electrophysiological
study of the response properties of single identified mechanoreceptors in the
cat.
Krauspe R, Schmidt M, Schaible HG.
Physiologisches Institut, Universitat Wurzburg, Germany.
In anesthetized cats, electrophysiological recordings were made from twenty-six
single thick myelinated afferent fibers of the posterior articular nerve of the
knee joint that had sensory endings in the anterior cruciate ligament. Most
afferent fibers arising from the anterior cruciate ligament were activated by
application of local pressure to discrete sites of the ligament, near the
attachment to the femur. Afferent fibers from the anterior cruciate ligament did
not fire when the knee was in the resting position at 30 degrees of flexion, but
they were activated when the knee joint was extended and flexed and externally
or internally rotated. Whereas responses were induced by movements in the
working range of motion of the knee, activity was markedly increased when the
joint was hyperextended and externally or internally rotated. These findings
suggest that mechanoreceptors with myelinated axons provide information about
tension of the anterior cruciate ligament.
PMID: 1548266 [PubMed - indexed for MEDLINE]
11: Clin Orthop. 1991 Jul;(268):161-78.
A sensory role for the cruciate ligaments.
Johansson H, Sjolander P, Sojka P.
Department of Physiology, University of Umea, Sweden.
Morphologic, physiologic, and clinical evidence for the sensory role of the
cruciate ligaments is reviewed. The cruciate ligaments accommodate
morphologically different sensory nerve endings (Ruffini endings, Pacinian
corpuscles, Golgi tendon organlike endings, and free nerve endings) with
different capabilities of providing the central nervous system with information
not only about noxious and chemical events but also about characteristics of
movements and position-related stretches of these ligaments. A survey of
available data reveals that low threshold joint-ligament receptor (i.e.,
mechanoreceptor) afferents evoke only weak and rare effects in skeletomotor
neurons (alpha-motor neurons), while they frequently and powerfully influence
fusimotor neurons (gamma-motor neurons). The effects on the gamma-muscle-spindle
system in the muscles around the knee are so potent that even stretches of the
cruciate ligaments at relatively moderate loads (not noxious) may induce major
changes in responses of the muscle spindle afferents. As the activity in the
primary muscle spindle afferents modifies the stiffness in the muscles, the
cruciate ligament receptors, via the gamma-muscle-spindle system, may
participate in the regulation and preprogramming of the muscular stiffness
around the knee joint and thereby of the knee joint stiffness. Thus, the sensory
system of the cruciate ligaments is able to significantly contribute to the
functional stability of the knee joint.
Publication Types:
Review
Review, Academic
PMID: 2060205 [PubMed - indexed for MEDLINE]
12: Acta Anat (Basel). 1991;141(1):8-14.
Intrinsic innervation of the rat knee joint articular capsule and ligaments.
Marinozzi G, Ferrante F, Gaudio E, Ricci A, Amenta F.
Istituto Superiore di Educazione Fisica Statale (ISEF), Roma, Italia.
In spite of the practical importance of having a detailed knowledge of knee
joint innervation to understand the pathophysiologic aspects, little information
is now available concerning the density and pattern of the nerve fibres which
are distributed to it. The present study has been designed to investigate the
density and distribution of nerve fibres and receptor corpuscles in the knee
joint articular capsule, cruciate and collateral ligaments in the rat, using the
acetylcholinesterase (AChE) histochemical in toto staining technique. The
investigation was performed on male Wistar rats of 3 months of age, some of
which had been treated with capsaicin to deplete their afferent 'C' fibres of
their content of neuropeptides. AChE-positive nerve fibres and different types
of receptor corpuscle endings were found within articular capsule and ligaments.
The highest density of AChE-positive nerve fibres was noticeable in the fibular
collateral ligament followed by the tibial collateral ligament, the posterior
cruciate ligament, the anterior cruciate ligament and the articular capsule. In
the articular capsule the number of type I endings was higher than in the
ligaments. The opposite is true for the other type of receptor corpuscles found
as well as for nerve endings. Capsaicin treatment significantly reduced the
density of AChE-positive nerve fibres in knee joint ligaments but did not affect
nerve fibres in the articular capsule. Moreover, it caused the disappearance of
some kind of receptor corpuscles within the collateral and cruciate ligaments.
The above data collectively suggest that the AChE in toto staining technique may
represent a good method for investigating joint innervation and that a
significant percentage of nerve fibres supplying knee joint ligaments is
represented by C fibre afferents.
PMID: 1950424 [PubMed - indexed for MEDLINE]
13: Anat Anz. 1991;173(4):233-8.
Mechanoreceptors in the canine anterior cruciate ligaments.
Yahia LH, Newman N.
Ecole Polytechnique/Faculty of Medicine Montreal, Department of Orthopaedics,
Hotel-Dieu Hospital, Montreal, Canada.
Canine anterior cruciate ligaments were sectioned into sagittal, frontal and
horizontal segments which were stained in bulk using a modified gold chloride
method. Segments were then serially sectioned on a sliding microtome at 100
micron, mounted on slides, dehydrated and coverslipped. Abundant Ruffini and
pacinian receptors were identified within the substance of the ligament. These
receptors were innervated by 5 to 10 micron diameter axons penetrating from the
peripheral synovium investing the ligament. The anterior cruciate ligament is
capable of afferent input to the central nervous system of importance to the
biomechanical function of the knee joint.
PMID: 1803948 [PubMed - indexed for MEDLINE]
14: Neurosci Lett. 1989 Jul 17;102(1):33-8.
Sensory nerve endings in the cat cruciate ligaments: a morphological
investigation.
Sjolander P, Johansson H, Sojka P, Rehnholm A.
Department of Physiology, University of Umea, Sweden.
The histology of the cat anterior and posterior cruciate ligaments was studied
using the modified Gairns gold chloride staining for neural elements. Ruffini
endings, Pacinian corpuscles, Golgi tendon organ-like endings and free nerve
endings were identified. All receptor types were most frequently found close to
the tibial and femoral insertions. The results are consistent with our earlier
findings that small increases in the tension of the ligaments can potently
influence the fusimotor system to the muscles acting at the knee joint, and
thereby participate in the regulation of their stiffness and the knee joint
stability.
PMID: 2779842 [PubMed - indexed for MEDLINE]
15: Am J Anat. 1988 May;182(1):16-32.
Mechanoreceptors in articular tissues.
Zimny ML.
Department of Anatomy, Louisiana State University Medical Center, New Orleans
70112-1393.
The morphology, distribution, and function of mechanoreceptors in joint
capsules, ligaments, knee-joint menisci, and articular disks of the
temporomandibular joints of animals, including humans, have been reviewed. In
addition to free nerve endings, three types of joint receptors are present in
most animal joints: 1) a Ruffini-like receptor situated in the capsule, 2) a
Golgi tendon organ situated in a ligament; and 3) the encapsulated Pacinian-like
corpuscle. In the anterior cruciate ligament, nerve fibers enter from the
subsynovial connective tissue and terminate in receptors. Most of the receptors
are found in the distal portion of the ligament. In the meniscus, nerves
penetrate the outer and middle one-third of the body and the horns from the
perimeniscal tissue, with a greater concentration at the horns. In the
temporomandibular articular disk, the mechanoreceptor density is greatest at the
periphery and progressively decreases toward the center. If a joint has an
intra-articular structure, mechanoreceptors undoubtedly are present within it.
The concentration of mechanoreceptors appears greater in areas related to the
extremes of movement and probably represents the first line of defense in
sensing these extremes. These afferent discharges elicit support from
discharging mechanoreceptors located in the joint capsule and subsequently from
those in the surrounding muscles. This total afferent output alerts the central
nervous system of impending injury, which can then be averted through reflex
mechanisms.
Publication Types:
Review
Review, Tutorial
PMID: 3291597 [PubMed - indexed for MEDLINE]
16: J Bone Joint Surg Am. 1987 Feb;69(2):243-7.
Neural anatomy of the human anterior cruciate ligament.
Schutte MJ, Dabezies EJ, Zimny ML, Happel LT.
The histology of the anterior cruciate ligament was studied by a modified
technique of the Gairns gold chloride stain for neural elements. Three
morphological types of mechanoreceptors and free nerve-endings were identified:
two of the slow-adapting Ruffini type and the third, a rapidly adapting Pacinian
corpuscle. Rapidly adapting receptors signal motion and slow-adapting receptors
subserve speed and acceleration. Free nerve-endings, which are responsible for
pain, were also identified within the ligament. These neural elements comprise 1
per cent of the area of the anterior cruciate ligament.
PMID: 3805085 [PubMed - indexed for MEDLINE]
17: Nippon Seikeigeka Gakkai Zasshi. 1986 Dec;60(12):1283-92.
An autoradiographic study of the distribution of sensory nerve endings in the
knee joint of the rat.
Kanatani Y, Hirohata K, Umetani T.
The distribution of sensory nerve endings of the knee joint in rats has been
investigated by autoradiography of 3H-leucine. Sections were made and each
section was examined by autoradiography and silver impregnation staining. Free
nerve endings were found only in the synovial membrane, the menisci and their
synovial junction. In the joint capsule, capsulated sensory nerve endings were
sparsely distributed. Numerous sensory nerve endings were found at the insertion
of the patellar ligament, the collateral ligament and the cruciate ligament.
These resembling Golgi-Mazzoni nerve endings or capsulated sensory nerve endings
are thought to be proprioceptors. Radioactivity, which would indicate the
presence of sensory nerve endings, was not recognized in the osseous tissue. It
is hypothesized that proprioceptor at the insertion of ligaments plays an
important role as monitor of joint motion by the reflex pathway.
PMID: 3572134 [PubMed - indexed for MEDLINE]
18: Anat Rec. 1986 Feb;214(2):204-9.
Mechanoreceptors in the human anterior cruciate ligament.
Zimny ML, Schutte M, Dabezies E.
This study was undertaken to identify and quantitate mechanoreceptors in the
human anterior cruciate ligament (ACL). Ligaments from six human subjects were
obtained at autopsy, cut into cross-sectional segments 1.0-1.5 cm thick, and
kept oriented as to the femoral and tibial attachments. The segments were
stained in bulk by using a modified gold chloride method, frozen, and sectioned
on a sliding microtome at 100 microns. The sections were floated in alcoholic
gelatin, mounted on slides, dehydrated, and coverslipped. Serial sections were
studied with the light microscope and receptors were photographed.
Cross-sectional maps of every tenth section were made outlining the periphery of
the ACL and the receptors within that section. With these maps, a computerized,
morphometric analysis of the ACL was done, thus obtaining the percentage of
receptors in each section and in each ACL. In addition to free nerve endings,
two morphologically distinct mechanoreceptors were identified: (1) Ruffini end
organs and (2) Pacinian corpuscles. Preliminary morphometric analyses show that
populations of mechanoreceptors are greater at the femoral and tibial ends of
the ligament and constitute approximately 2.5% of the ligament. Based on these
findings the human ACL has the anatomic basis for a discriminating afferent
outflow to the central nervous system.
PMID: 3954077 [PubMed - indexed for MEDLINE]
19: J Bone Joint Surg Am. 1984 Sep;66(7):1072-6.
Mechanoreceptors in human cruciate ligaments. A histological study.
Schultz RA, Miller DC, Kerr CS, Micheli L.
We obtained human cruciate ligaments at the time of total knee replacement and
from autopsy and amputation specimens, and examined histological sections of the
ligaments for the presence of mechanoreceptors using the Bodian, Bielschowsky,
and Ranvier gold-chloride stains for axons and nerve-endings. The cruciate
ligaments obtained at the time of total knee replacement were too distorted by
disease processes to be of use. The autopsy and amputation specimens, however,
contained fusiform mechanoreceptor structures measuring 200 by seventy-five
micrometers, with a single axon exiting from the capsule of the receptor. One to
three receptors were found at the surface of each ligament beneath the synovial
membrane, and were absent from the joint capsules and menisci. Morphologically
the receptors resembled Golgi tendon organs, and it seems likely that they
provide proprioceptive information and contribute to reflexes inhibiting
injurious movements of the knee. This is the first histological demonstration of
mechanoreceptors in human cruciate ligaments.
PMID: 6207177 [PubMed - indexed for MEDLINE]
LAURIE EDGE-HUGHES
Re: Debriding the CCL remnants
Hey Laurie,
Hope you are hanging in there. No biggie, I just thought you might be interested in the response from one of our surgeons below.
E.
___
Hey Surgeons,
I noticed in your surgery notes that at least K. and A. are debriding the CCL in partial tears when doing the TPLO. There has been a lot of discussion in the rehab community (and I thought this was presented a year or two ago at ACVS) that it is better to leave the remnants because there are proprioceptive fibers in the ligament and they recover better when you leave it.
I’m curious if you guys have heard this. What you know about it, etc.
Thanks
E
------
It's still a bit controversial but the current general consensus among surgeons is to debride the remaining in-tact portions. There was a movement about 10 years ago to leave it to provide some stability. It was supported by the Gulf Coast surgeons who did some second looks and found around 80% were in tact after a year (don't quote me exactly). Subsequent work from Cook's lab found that once a tear is initiated, it finishes, given enough time, due to disruption of blood supply I think. I couldn't find the Cook article, I think it's in the human lit but I'll ask him.
I used to leave in-tact portions. I (and colleagues) found, subjectively, that those dogs frequently had recurrent bouts of lameness. I suspect that they get lame when more of the remaining degenerating ligament tears.
A
Hope you are hanging in there. No biggie, I just thought you might be interested in the response from one of our surgeons below.
E.
___
Hey Surgeons,
I noticed in your surgery notes that at least K. and A. are debriding the CCL in partial tears when doing the TPLO. There has been a lot of discussion in the rehab community (and I thought this was presented a year or two ago at ACVS) that it is better to leave the remnants because there are proprioceptive fibers in the ligament and they recover better when you leave it.
I’m curious if you guys have heard this. What you know about it, etc.
Thanks
E
------
It's still a bit controversial but the current general consensus among surgeons is to debride the remaining in-tact portions. There was a movement about 10 years ago to leave it to provide some stability. It was supported by the Gulf Coast surgeons who did some second looks and found around 80% were in tact after a year (don't quote me exactly). Subsequent work from Cook's lab found that once a tear is initiated, it finishes, given enough time, due to disruption of blood supply I think. I couldn't find the Cook article, I think it's in the human lit but I'll ask him.
I used to leave in-tact portions. I (and colleagues) found, subjectively, that those dogs frequently had recurrent bouts of lameness. I suspect that they get lame when more of the remaining degenerating ligament tears.
A
Re: Debriding the CCL remnants
I still think to cut it (especially if it’s a good portion of the caudolateral band left) is like saying, let’s pull all the teeth in this 40 year old woman because they’ll all likely fall out by the time she’s 80.
And, a bout of lameness on down the road isn’t something horrible… it could be a short term inflammatory response to ‘perhaps’ a tear… which is recoverable in my mind!
Ahh surgeons!
Laurie
And, a bout of lameness on down the road isn’t something horrible… it could be a short term inflammatory response to ‘perhaps’ a tear… which is recoverable in my mind!
Ahh surgeons!
Laurie
LAURIE EDGE-HUGHES
Re: Debriding the CCL remnants
Here is the question though. Do you feel they rehab better truly if you leave it in vs take it out? I get good results with my local surgeons, not realizing until now that they had been debriding. Apparently, the other issue is that they find they get more OA later if they leave it in. Nidus?
Hope you are hanging in there.
E
Hope you are hanging in there.
E
Re: Debriding the CCL remnants
Hmmm…. Good questions! And now that you bring it up, I don’t know exactly what our group of local surgeons do.
I speak more from a pragmatic standpoint - that something holding top to bottom would have to help with joint stability and proprioception. (or as Gail Smith called it, “the inconvenient vector” that neither the TPLO or TTA addresses.)
But do I have a repertoire of dog that I know exactly what they did and/or how they looked years later… no. Because, like you, I’m not sure what they have all been doing all these years!
More OA if they leave it in… my first reaction is to call Bullshit. But then if I calm down to question why that could be, I’m left scratching my head. Could it be that this is occurring in dogs with a partial tear of the caudolateral band. (i.e. full tear of the craniomedial and partial tear of the caudolateral)… which then would still have that degenerative process going on and some inflammatory cells… all in all continuing to anger the joint?
I’m going to put this on the FourLeg Forum. We can see if anyone else has thoughts!
Laurie
I speak more from a pragmatic standpoint - that something holding top to bottom would have to help with joint stability and proprioception. (or as Gail Smith called it, “the inconvenient vector” that neither the TPLO or TTA addresses.)
But do I have a repertoire of dog that I know exactly what they did and/or how they looked years later… no. Because, like you, I’m not sure what they have all been doing all these years!
More OA if they leave it in… my first reaction is to call Bullshit. But then if I calm down to question why that could be, I’m left scratching my head. Could it be that this is occurring in dogs with a partial tear of the caudolateral band. (i.e. full tear of the craniomedial and partial tear of the caudolateral)… which then would still have that degenerative process going on and some inflammatory cells… all in all continuing to anger the joint?
I’m going to put this on the FourLeg Forum. We can see if anyone else has thoughts!
Laurie
LAURIE EDGE-HUGHES
-
David Lane
- Posts: 164
- Joined: Mon Oct 24, 2016 10:51 pm
Re: Debriding the CCL remnants
My understanding of the debate is that cutting the remaining ligament will reduce secondary pain from the remaining strands - this is required for either an ex. cap. or TTA. However, adequately rotated TPLOs on second look arthroscopy, show that the ligament "settles down" and therefore can be left behind. Aside from proprioception, the remaining ligament also lends stability on internal rotation, which a TPLO does not (thus avoiding pivot shifts).
When a ligament is resected, there is still exposed ligament in the joint, and I'm not sure why that exposed end of the transection would induce any different amount of inflammation than the location of the partial tear would. This argument is the most common one I hear from those that advocate leaving the ligament behind. I haven't heard of someone advocating cutting the entire ligament for a TPLO in a long time though.
When a ligament is resected, there is still exposed ligament in the joint, and I'm not sure why that exposed end of the transection would induce any different amount of inflammation than the location of the partial tear would. This argument is the most common one I hear from those that advocate leaving the ligament behind. I haven't heard of someone advocating cutting the entire ligament for a TPLO in a long time though.
David Lane DVM
ACVSMR, CVA, CVSMT, CCRP
ACVSMR, CVA, CVSMT, CCRP
Re: Debriding the CCL remnants
Sooo… I think this is really interesting. Our surgeon here is a pretty thoughtful one. He was my business partner as we opened GVR. I had asked him about all of this, then went to you when I realized he was debriding the ligaments. I wanted to see what his response was to David’s comment.
My big question still stands though. Does leaving the ligament in actually make the rehab better? Based on what our surgeon is saying and from what I am seeing (ie my debrided TPLO cases do very well and are sound by 6 wks), I don’t think so.
Read on….
Evelyn
--------
I think about this issue a lot because I literally have to make this decision every week.That said, I still do not know the right answer.
To address David's arguments: In theory, and as shown at least in-vitro, TTA neutralizes tibial thrust so the argument for or against should be the same for TPLO or TTA. That said, Max TPA that a TTA can neutralize is around 28 - 30 degrees so I suspect there are a lot of inadequately neutralized knees out there because TTA surgeons do them regardless of TPA.
True, remaining ligament can help prevent internal rotation but there is scant evidence that persistent internal rotation is an issue with TPLO. In fact, Stan Kim at UF has done 3D fluoro kinematics of dogs walking post TPLO (amazing research) and one of the things his group has shown is that TPLO induces external rotation during weight bearing. This is not necessarily good since normal kinematics is internal rotation with flexion during weight bearing (screw-home mechanism) but regardless, not sure it is an issue. Pivot shift is pretty rare and I don't really worry about preventing it.
I don't know if anyone knows if proprioceptive function is preserved once the ligament is partially torn. There is a hypothesis that loss of proprioception may be part of the pathogensis/etiology of CCL tear. Some initial traumatic event causes microscopic ligament injury,disrupting proprioception, and it continue to tear from there due to overloading.
Regarding ongoing inflammation due to ligament, yes, even after debridement there will be exposed ends but I believe we should be considering the total mass of exposed ligament in there, which is obviously greater without debridement.
I don't believe the arthroscopic diagnosis of "settling down". It's from Beale/Whitney's group. I've seen them present the data and videos and it is quite soft and subjective. Hard for it not to be biased as well.
I've based my decision on experience watching dogs recover when I used to leave partials in tact. It was my admittedly subjective opinion that they had slower recoveries and/or were more likely to have subsequent episodes of lameness. I didn't really care one way or another - I just left them in based on the Beale/Whitney results, but decided I didn't like the outcomes before any Jimi Cook preaching. No doubt others have different opinions.
You are familiar with Callie Horn. So I cut her second side back in Feb. I was honestly worried that the dog did not have a CCL tear but she was persistently lame, had a previous tear on the other side, and had a tiny bit of effusion. At sx the ligament was grossly normal, maybe a bit discolored, I left it in-tact and did the TPLO. She stayed lame for the next 4-5 months. Her plateau rocked back a bit to 15 degrees during healing but the knee was always stable. I decided to re-cut her based on the poor outcome. The CCL was still in-tact, no tears but appeared a little more degenerative with some pannus. I debrided it entirely and re-cut her tiba. I can't measure it now due to the plate but it's between 0 and 5 degrees. She said from day 1 post-op the dog as been much better and is almost sound here today.
I guess you could make the argument that she was persistently lame because thrust wasn't neutralized and she was loading a degenerating, painful ligament. I've seen dogs with 15 degree post-op TPA's with complete tears do fine, so maybe debriding it make the procedure more forgiving.
In my mind the potential benefits of leaving it in do not outweigh the potential risks - I've seen the downsides, haven't seen the advantages.
My big question still stands though. Does leaving the ligament in actually make the rehab better? Based on what our surgeon is saying and from what I am seeing (ie my debrided TPLO cases do very well and are sound by 6 wks), I don’t think so.
Read on….
Evelyn
--------
I think about this issue a lot because I literally have to make this decision every week.That said, I still do not know the right answer.
To address David's arguments: In theory, and as shown at least in-vitro, TTA neutralizes tibial thrust so the argument for or against should be the same for TPLO or TTA. That said, Max TPA that a TTA can neutralize is around 28 - 30 degrees so I suspect there are a lot of inadequately neutralized knees out there because TTA surgeons do them regardless of TPA.
True, remaining ligament can help prevent internal rotation but there is scant evidence that persistent internal rotation is an issue with TPLO. In fact, Stan Kim at UF has done 3D fluoro kinematics of dogs walking post TPLO (amazing research) and one of the things his group has shown is that TPLO induces external rotation during weight bearing. This is not necessarily good since normal kinematics is internal rotation with flexion during weight bearing (screw-home mechanism) but regardless, not sure it is an issue. Pivot shift is pretty rare and I don't really worry about preventing it.
I don't know if anyone knows if proprioceptive function is preserved once the ligament is partially torn. There is a hypothesis that loss of proprioception may be part of the pathogensis/etiology of CCL tear. Some initial traumatic event causes microscopic ligament injury,disrupting proprioception, and it continue to tear from there due to overloading.
Regarding ongoing inflammation due to ligament, yes, even after debridement there will be exposed ends but I believe we should be considering the total mass of exposed ligament in there, which is obviously greater without debridement.
I don't believe the arthroscopic diagnosis of "settling down". It's from Beale/Whitney's group. I've seen them present the data and videos and it is quite soft and subjective. Hard for it not to be biased as well.
I've based my decision on experience watching dogs recover when I used to leave partials in tact. It was my admittedly subjective opinion that they had slower recoveries and/or were more likely to have subsequent episodes of lameness. I didn't really care one way or another - I just left them in based on the Beale/Whitney results, but decided I didn't like the outcomes before any Jimi Cook preaching. No doubt others have different opinions.
You are familiar with Callie Horn. So I cut her second side back in Feb. I was honestly worried that the dog did not have a CCL tear but she was persistently lame, had a previous tear on the other side, and had a tiny bit of effusion. At sx the ligament was grossly normal, maybe a bit discolored, I left it in-tact and did the TPLO. She stayed lame for the next 4-5 months. Her plateau rocked back a bit to 15 degrees during healing but the knee was always stable. I decided to re-cut her based on the poor outcome. The CCL was still in-tact, no tears but appeared a little more degenerative with some pannus. I debrided it entirely and re-cut her tiba. I can't measure it now due to the plate but it's between 0 and 5 degrees. She said from day 1 post-op the dog as been much better and is almost sound here today.
I guess you could make the argument that she was persistently lame because thrust wasn't neutralized and she was loading a degenerating, painful ligament. I've seen dogs with 15 degree post-op TPA's with complete tears do fine, so maybe debriding it make the procedure more forgiving.
In my mind the potential benefits of leaving it in do not outweigh the potential risks - I've seen the downsides, haven't seen the advantages.
Re: Debriding the CCL remnants
Great discussion… but I can’t answer your question. So I think the best we can do is go with YOUR clinical observations to guide (us all)!
Thank you so much for sharing this. (I’m putting it up on the forum for all to thing/learn/read/ ponder upon!)
Cheers,
Laurie
Thank you so much for sharing this. (I’m putting it up on the forum for all to thing/learn/read/ ponder upon!)
Cheers,
Laurie
LAURIE EDGE-HUGHES