Anterior Cruciate Ligament - Science topic

I would consider cognitive-motor dual-tasks, while not the same visual knockdown can at least disrupt attentional compensation for motor control

Hi,

Thank you so much Dr. Putnis.

A variable that is not normally distributed is a dispersed variable and affects the value of the correlation. The greater the dispersion, the lower the correlation, because the correlation depends on the linear relationship between two variables.

@Ganesh S Dharmshaktu sir thank you for your inputs, before the advancement of MR imaging and arthroscopy; the internal derangement of knee in children was generally managed conservatively with rest and immobilization. This has greater advantage for nondisplaced/minimally displaced avulsions of tibial eminence. The risk vs benefit of conservative

approach for ACL injury in children needs to more in attention.

Hi Manish. Following the stability trial results I have started doing let in all hamstring acl s under 25, sportsmen and in revisions. Bw

Thanks a lot Dr Ganesh and Dr Rathore

But in that case it wouldn't have been indexed by Google Scholar in the first place

Sensorimotor rehabilitation includes rehab tools targeting neural and muscular components. It may include electrotherapy, manual therapy, and strenghening regimes. Balance, coordination, and muscle performance are three different things, requiring different therapeutic protocols. In Hungary, rehabilitation after ACLt is a 4 months managment program, that includes various different protocols; starting from low impact exercises to high impact balance training. The asked question need to be specified with more clarity to have a more specific answer.

ACL rupture should be treated as early as possible to prevent secondary meniscal and chondral damage and the best time for reconstruction is between four and six weeks after injury.

An interesting methodology and analysis with some great results. Also demonstrating the fantastic influence of Freddie Fu in this field!

I regret to inform all those who were interested in the KT 1000's that corporate has decided to keep them for possible future use, even though they didn't know we had them. Sorry for any inconvenience this may have caused. This may change in the future but as of now they will not be given away.

Hi Mario, this paper seems good after reading the abstract. Unfortunately is not in English. Whereas many author might want to cite the author

see

It is a very interested question . I agree with Ganesh answer

Also these links may help yoy

If the question is pointing to the functional allowance of a patient's knee range of movement then the answer is, yes, they can kneel.

If on the other hand is pointing to the possible anterior knee pain then the answer is that, whatever we do we may have as result anterior knee pain. It is known that BTB is "accused" for anterior knee pain. This is something found in literature and all surgeons who are not using this technique will insist that this is a significant problem. On the other hand surgeons who are using the BTB technique will say that this finding is of limited value as it is not found very often. There is an in vitro biomechanical study reporting greater and stronger knee stability following the BTB technique. Clinically this was supported giving as reason the better healing of the graft.

The question is, does the pathology of the patellofemoral joint wear pre-existed? T

he ACL instability has as result of overloading the patellofemoral joint so potential wear of the joint even prior to the operation. Questions to be answered. How quickly post injury the patient presented to he surgeon? As already mentioned what are the co-existing injuries within the knee? Do we analyse the way the BTB was harvested?

If we can differentiate all we may have a small number of patients and our statistics may not of great value. So to be honest as we have variation of patients, different mechanisms or combination of injuries, post-operative plans sometimes unique to institutions and age of patients and their activities and expectations which they vary, we answer the questions according to our preferences and believes and by analysing the statistics to sometimes to our favour.

Truth is that all techniques performed may result to some anterior discomfort. This discomfort may be worse during kneeling. So my opinion is that any surgical technique for ACL reconstruction has a degree of "complication" named anterior knee pain.

At first you have to be sure there is no injuries due to a luxation (you have to check the arteries, high risk of postop. compartment syndrome!).

Then I would reconstruct the MCL with internal ligament bracing (suture tapes with anchors if available). If PCL is completely instable and you have enough OR time, then I would recommend to reconstruct the PCL with Quad tendon in one session. Otherwise you can stabilize the PCL with a brace.

I do not think that full ligament repair of MCL + PCL + ACL in one session is recommended.

And what about cartilage an meniscus??

This link may help yoy Anton

The standard method by identifying semiT or gracilis on flexed knee is followed by a mini incision followed by use of tendon stripper to obtain desired tendon part. The muscles and attached soft tissue is removed manually and desired bundles are created with use of ethibond as suture material over a tendon board.

An important clinical question and one that many people are starting to explore in quality of movement screenings. Below are several studies that have explored the topic of dorsiflexion's influence on lower extremity movement broadly during a variety of tasks. Hope these help.

AM

Dear Colin,

Unfortunately I could not find a copy of the Baller Identity Measurement Scale (BIMS). Maybe the following paper will help you:

Harrison CK, Traynowicz L, Bukstein S, et al. I am what I am? The Baller Identity Measurement Scale (BIMS) with a Division I football team in American higher education. Sport Sciences for Health 2014;10(1):53-58. https://works.bepress.com/scott_bukstein/2/download/

All the best for your research,

Martin

Hi Nardi,

As Luis pointed out, you should try to clarify your search criteria. One big question would be whether you are looking for articles concerning athletic or non athletic-populations.

An interesting article to start with could be the 'review of reviews' on ACL rehabilitation by Lobb et al.

Lobb, R., Tumilty, S., & Claydon, L. S. (2012). A review of systematic reviews on anterior cruciate ligament reconstruction rehabilitation. Physical Therapy in Sport, 13(4), 270-278.

MRC

An excellent question. I think it works for some extent. The previous answers explained the mechanism and the extent of such training in details. However, we conducted a study on athletes with meniscus injuries, and some results were impressive. From my clinical experience, this training would benefit more younger athletes.

If this is fresh trauma, your patient need immobilization for about 6 weeks and quadriceps isometric exercises. The control examination would show how stable or unstable is the knee. If unstable then surgical reconstruction is indicated.

Hello Kristina,

You could also read this article:

Evidence-based clinical practice update: practice guidelines for anterior cruciate ligament rehabilitation based on a systematic review and multidisciplinary consensus Nicky van Melick et. al.; Br J Sports Med bjsports-2015-095898Published Online First: 18 August 2016

Good read about ACL and also  part about the evidence of pre-operative physical therapy.

Kind regards,

Peter

ACL reconstruction followed by ACL protocol of strengthening Hamsrings and gradual Knee bending and Quadriceps build up. Hmsrings strenghthening is more important than Quadriceps which most of the Physiotherapists do not do

Dear Friend,

    There are many protocols in our text books .Rehabilitation protocol strictly depend on surgeons concern. Aim of the protocol is different in different settings. Many surgeons usually focus own slow rehab protocol rather than fast. Because, certain risks are there. otherwise surgeons fully trust in the physiotherapist.

   You can use Brotzman Protocol. Its really better

 Double PCL sign may be seen on sagittal MRI image of knee when the bucket handle fragment of the medial meniscus tilts towards the  centre of the joint and comes to lie anterio-inferior to intact PCL. Integrity of ACL is necessary  for this sign to appear as it prevents further flipping of the meniscal fragment away from knee centre.

Interestingly,in some  patients  BHT of lateral meniscus with ACL tear can also lead to this sign.

Sensitivity: 27%–53%[earlier considered 100%]

Specificity:98%-100%

Other mimics-presence of meniscofemoral ligament(of Humphrey) or oblique menisco-meniscal ligament.One must trace the course.

I think porcine will be better than rabbit for ACL reconstruction studies.

Here are my thoughts on the management of ACL cysts.

1. Small, asymptomatic ACL cysts (discovered on MRI) are usually left alone.

2, Large ACL cysts may present with loss of knee extension due to impingement against the roof of the intercondylar notch of the femur; these cyst can be treated by arthroscopic debridement. 

3. The status of the ACL should be checked at the time of arthroscopic surgery and treated on its own merit. 

Thank you

Hi,

I think that each situation is very particular and requires a specific analyse, mainly to conduct the adequate treatment. In general, a primary role of MRI in the management of the patient with an ACL injury lies in allowing confident diagnosis or exclusion of a tear in patients with equivocal physical examination findings. It should be emphasized, however, that ACL injury management is critically dependent on accurate diagnosis of other coexisting knee internal derangements, in particular tears of the lateral collateral ligament (LCL), posterior cruciate ligament (PCL), and the menisci. In this way, patients with combined LCL/ACL or PCL/ACL injuries often have profound instability requiring aggressive surgical management. In the instance of a coexisting LCL tear, intervention may be hastened as LCL injuries are optimally repaired within 1-3 weeks. An unoperated LCL tear predisposes an ACL graft to early failure. With regards to clinical diagnosis, in general a physical diagnosis is particularly difficult in large patients, in patients with strong secondary muscular restraints, and in patients with an acute injury and soft-tissue swelling and guarding. Partial ACL tears are also difficult to diagnose on physical examination. However, MRI may provide pivotal diagnostic information about the ACL in all of these settings.

I hope this helps.

We used trypsin to degrade cartilage. Usually put a small sample into 0.1 mg/ml trypsin solution more than 8 hours. but you might use higher concentration trypsin.

dear Ahmed Gaballah

The following research will help you to answer the question

best regards

http://onlinelibrary.wiley.com/doi/10.1002/jor.1100170107/abstract?systemMessage=Wiley+Online+Library+will+be+unavailable+on+Saturday+27th+February+from+09%3A00-14%3A00+GMT+%2F+04%3A00-09%3A00+EST+%2F+17%3A00-22%3A00+SGT+for+essential+maintenance.++Apologies+for+the+inconvenience.

It is not surprising to find degenerative changes of ACL in young athletes. Furthermore, if such changes exist this makes ACL more vulnerable because its strength, elasticity and durability reduce. So in similar cases further training in elite sports should be seriously discussed. Perhaps, change of sports kind should be considered, i.e. from athletics to swimming. 

Rosi,

I don't mind sharing at all.  The primary rationale for our dosage and frequency were to make the treatments clinically feasible within our primary field of athletic training were providers sometimes have limited time with individual patients.  However, we also wanted to build in multiple treatment sessions so that we could potentially train/improve the sensory system on top of treating the symptoms.  Much of the literature suggests that while a single session, of shorter duration, could be effective, multiple treatments result in a more meaningful response in select outcomes.  This was our first effort to determine if the larger responses were train to altering motor control programs within the patient by improving the degrees of freedom available to them.  Based on these results, we believe that is possible and are now working on the next steps to confirm these results.  I hope this helps

Erik

In the 1990’s a vast quantity of research was done to determine ways to prevent ACL injuries and predictive measures that could be used to identify those in need of such interventions (primarily female athletes). ACL rehabilitation protocols, some evidence based, some developed through trial and error, were developed that included neuromuscular training with aspects being touted as preventative. It is interesting to note that much of the information discovered between 1990 and 2005 has been ignored as individuals within the medical and rehabilitation profession continue to seek new remedies because they didn’t learn from the past.

In ACL rehabilitation, it has been demonstrated that functional deficits that can be linked to “neuromuscular” dysfunction persist for years after those undergoing ACL reconstruction have been discharged. One of the most striking, and seemingly completely ignored because it doesn’t fit the current orthodoxy, is the persistence of quadriceps weakness in the involved limb. Currently the focus of many researchers who advocate “closed kinetic chain” rehabilitation over “open kinetic chain” rehabilitation interventions, is on the hip abductors because those athletes who experience “non-contact” ACL injuries have what these people see as weakness and lack of endurance of the hip abductors which causes the knee to be predisposed to knee to valgus stress when cutting, landing from a leap, etc.

Once again, in the 1990’s researchers investigating the cause for a greater incidence of “noncontact” ACL injuries in female athletes discovered that females tend to cut differently than males. As any coach can tell you, girls and boys run differently. These researchers discovered that girls tended to allow their knees to collapse into a position of high valgus deviation as they decelerated an the knee flexed in preparation for the cut, this then became a strong varus deviation as the knee extended and they accelerated in the new direction. The male subjects had very little varus or valgus deviations as they cut, it was decelerate as the knee flexed, accelerate as the knee extended; keeping all of the forces in the sagittal plane. Additionally, other researchers discovered that not only were female athletes significantly weaker than male athletes, even when the loads were normalized, the relationship was especially more pronounced in the hamstrings and quadriceps, and the quadriceps:hamstring ratio.

In 2003, Salem, Salinas, & Harding published a paper in the Archives of Physical Medicine and Rehabilitation, in addition to other presentations at scientific meetings that demonstrated that the body had different motor programs for extending the lower extremity in a “closed kinetic chain” situation. If limb dominance was ascertained by “which leg do you kick a ball with?” The body used a hip dominant strategy on the non-dominant, support limb; and a knee (quadriceps) dominant strategy on the dominant, kicking leg. ACL injuries and reconstruction resulted in the injured leg adopting a “hip dominant” strategy. This finding has been validated in countless studies over the past 12 years.

Also of significance, the strong bias toward “closed kinetic chain” exercise for ACL rehabilitation has probably compounded the problem. Research has failed to discover the “best” way to perform the squat exercise. The reason is because the “best” way to squat is completely dependent on the skeletal arrangement of the individual’s hips. In physical therapy it is understood that some people’s hips are in an anatomically determined position of anteversion, retroversion, or neutral. This causes the knees and feet to have positions that are congruent with the position of the hip or incongruent with the hip position. Persons who squat in their “anatomically correct” position perform better, with proper neuromuscular input to activate the various muscles through what amounts to primitive reflex motor programs, while those who squat in a manner that is not “anatomically correct” produce alterations in neuromuscular coordination resulting in the adoption of faulty motor programs for squatting. These faulty programs affect how the body performs all activities. Therefore, as one uses proprioceptive (balance training) in the rehabilitation process after the ACL injury, similar activities and progression models would be used preventatively.

The athlete must be examined to insure that they are properly aligned when performing squats, proprioceptive training must become part of the training program, open chain, isolation exercises for the quadriceps and hamstrings must be performed (this is the topic of another paper, if you are interested), and specific high level plyometric and agility drills must be used when the strength and motor control issues have been adequately accomplished. Attached to this answer you will find some other materials related to this answer.      

1. Johnson AJ; Howell SM; Costa CR; Mont MA. The ACL in the arthritic knee: how often is it present and can preoperative tests predict its presence? Clin Orthop Relat Res. 2013 Jan;471(1):181-8, doi: 10.1007/s11999-012-2505-2.

BACKGROUND: TKA with retention of the anterior cruciate ligament (ACL) may improve kinematics and function. However, conflicting reports exist concerning the prevalence of intact ACLs at the time of TKA. QUESTIONS/PURPOSES: Therefore, we asked: (1) what was the ACL status at TKA; (2) what was the sensitivity and specificity of the Lachman test; (3) did MRI ACL integrity correlate with intraoperative observation; (4) did MRI tibial wear patterns correlate with ACL integrity; and (5) did ACL status depend on age or sex? METHODS: We evaluated 200 patients for ACL integrity at the time of TKA. All patients underwent a Lachman test under anesthesia. Intraoperatively, the ACL was characterized as intact, frayed, disrupted, or absent. In 100 patients, MRIs were performed, from which the ACL was graded as intact, indeterminate, or disrupted, and the AP location of tibial wear was categorized. RESULTS: The ACL was intact in 155 patients (78%). The Lachman test alone had poor diagnostic ability. The MRI predicted a tear, but we observed two ACLs with indeterminate status that were disrupted. All knees with anterior wear on the medial tibial condyle had an intact ACL (n = 45), and all knees with posterior wear on the medial tibial condyle had a disrupted ACL (n = 8). CONCLUSIONS: Although the Lachman test alone had poor sensitivity, when combined with MRI they together provide a sensitivity of 93.3% and specificity of 99%, which we believe makes these reasonable tests for assessing ACL status in the arthritic knee.

Fully agree with Timothy McTighe and William Murrell... But all this is also related to the kind of graft you use for your reconstruction and as far as I've been able to see there are significant differences between KJ, Hamstrings and Allografts!

Dear Parastoo Shamsekohan,

I dont know do you like to prepare a good engineering tissue for ACL or best characterization?

Hello Nitsche

Have you ever thought about Telos stress radiography to evaluate ACL laxity using anterior drawer or lachman test. it would be better choice to examine transnational stability.

If you are targeting dynamic evaluation, fluoroscopic motion analysis will be good choice.

best: Tserenchimed

Here's an interesting new reference that might be of help to you:

How does a combined preoperative and postoperative rehabilitation programme influence the outcome of ACL reconstruction 2 years after surgery? A comparison between patients in the Delaware-Oslo ACL Cohort and the Norwegian National Knee Ligament Registry.

Grindem H, Granan LP, Risberg MA, Engebretsen L, Snyder-Mackler L, Eitzen I.

Br J Sports Med 2015;49:6 385-389

Hope it helps.

All the best

     

Hello. I attached one study that tested a rabbit femur-ACL-tibia complex.

The doctor I work with uses good old fashioned x-rays at set periods.  Cost wise, that's probably your best bet, for the average citizen to use...

Apart from infrapatellar branch paresthesia sometimes a large hematoma can occur, post harvesting, in STG graft. 

For BTB I saw a technique of harvesting the outer portion of the tendon (less than 1/3, which is the case for the classic middle third BTB graft) that had less anterior pain than the classic BTB technique presented to us by prof. Georgoulis A

Quadriceps tendon has been reported with minimal donor site morbidity

This could help:

A very recent anatomical work confirms the shape of the ACL./ This work is submitted not yet published. It has been done on fresh specimens and confirms the "C" shaped attach on the tibia and a coma shaped attach on the femur. If you want check this result, just harvest fresh ACL after carefull removal of the synovial, stain it and study the structure.

Dear Alexandre,

i focused on this problems since a year and a half. There is no objective data for a single criteria to return to sport. The evidence level is IV as reported in:

Barber-Westin SD, Noyes FR. Factors used to determine return to unrestricted sports activities after anterior cruciate ligament reconstruction. Arthroscopy. 2011 Dec;27(12):1697-705. 

There is a lack of evidence although there are a lot of recommendations without scientific background.

I always add DNAse to my cells prior to lysis, regardless of whether I use sonication, a cell disrupter, a french press or BugBuster. If for some reason you also need to remove RNA you can either add RNAse A on top of the DNAse 1 or just go for Benzonase, which has both DNAse and RNAse activity and works really well (though it is a bit pricey).

Though I have heard that sonication should reduce most of the large DNA strands, I find that without DNAse it still produces somewhat viscous samples (it's the DNA released from the lysed cells that makes the cell lysate viscous). The viscosity makes it more difficult to separate the soluble fraction from the insoluble fraction using centrifugation and also clogs up any filters you might need to use before loading the soluble fraction onto a purification column.

Measurement of MVC of hamstrings could be crucial......

Thank you for your help.

Dear Ravi

The treatment of a meniscal injury will depend on its location, size, time of occurrence, age and level of sports activity of the patient. In my opinion, the treatment may be non-surgical for elderly patients with low functional demands and the remaining patients i performl arthroscopic surgery, even with minimal damage because I agree with you that this minimal lesion can evolve and cause more damage than it was

Dear Murali

It was a pleasure

Regards

The classic techniques (Hey Groves, Lindemann, Lange, etc) with preserved insertions of gracillis and/or semitendinosus give excellent results. Unfortunately, these surgical procedures are done through larger (sometimes multiple) incisions. That's why they are not so often used in favour of less invasive surgery with BTB.

Dear Ravi

Below comments from Bernard R. Bach, MD, - What Do You Do If You Drop the Graft on the Floor? Healio Orthopedics.

Great care must be taken to avoid contamination during harvest and or preparation of the graft for anterior cruciate ligament (ACL) reconstruction. Our protocol emphasizes that the surgeon who harvests the graft personally walks the tissue to the back table to reduce the risk of dropping the graft. Handing off of a freshly harvested graft to other members of the surgical team for preparation simply increases the likelihood dropping the graft. With this protocol, the senior author has not dropped any grafts in over 20 years of practice, including more than 1700 knee ligament procedures. Careful attention must be paid during preparation on the back table as well. The fully prepared graft is placed in a marked kidney basin. All operative personnel are informed to prevent the graft from being inadvertently passed off the sterile field

When the graft is brought to the operative field for graft placement, if it is wrapped in a laparotomy sponge, theoretically the only contaminated portion would be the sutures extending beyond the sponge if the graft were dropped.

If the graft is dropped, the salvage falls into one of several possible categories, namely cleaning the graft, using an alternative graft (auto or allograft), or stopping the procedure and completing the surgery at another time with a different graft.

One study showed a 58% rate of positive culture when the graft was dropped and left on the operating room floor for 15 s. Molina et al have shown that a 90-s soak in chlorhexadine gluconate is the most effective method to resterilize the graft

Another report found that a 30-min soak in 4% chlorhexadine followed by a 30-min soak in triple antibiotic solution (gentamicin, clindamycin, polymixin), followed by sterile saline wash was 100% effective in sterilizing contaminated rabbit patellar tendon grafts. In that same study, 10% povidone-iodine was 100% ineffective, as was triple antibiotic soak used in isolation.

A survey of sports medicine specialists found that most would choose cleansing the graft to manage the problem of a dropped graft. Forty-three surveyed surgeons reported having cleansed a contaminated graft and none reported postoperative infections.3

Another option is choosing an alternative graft. This requires preoperative consent from the patient or intraoperative consent from a family member and may be problematic for a patient who expects one graft type but ends up with another. Some surgeons routinely consent their patients for the use of an allograft should the autograph become contaminated or otherwise compromised. Again, if this option is selected, preoperative discussion with the patient is best because cultural or religious beliefs may preclude the use of cadaveric tissue.

Our preference would be cleansing the graft using a 30-min soak in 4% chlorhexadine gluconate followed by lavage with sterile saline, then another 30-min soak in triple antibiotic solution (0.1% gentamicin, 0.1% clindamicin, 0.05% polymyxin) and another sterile saline wash. Washing the chlorhexadine is crucial because chlorhexadine-induced chondrolysis has been reported.4 While this protocol is time consuming, it has solid scientific backing and would allow one to proceed with the same graft as planned preoperatively. One could consider a course of postoperative antibiotics, although we would refrain from this as it would likely only mask an underlying infection, delaying its definitive treatment. In addition, we recommend full disclosure to the patient regarding the incident and the low likelihood of any residual difficulties.

References

1. Molina ME, Nonweiller DE, Evans JA, DeLee JC. Contaminated anterior cruciate ligament grafts: the efficacy of 3 sterilization agents. Arthroscopy. 2000;16:373-378.

2. Goebel ME, Drez D Jr, Heck SB, Stoma MK. Contaminated rabbit patellar tendon grafts: in vivo analysis of disinfecting methods. Am J Sports Med. 1994;22:387-391.

3. Izquierdo R Jr, Cadet ER, Bauer R, Stanwood W, Levine WN, Ahmad CS. A survey of sports medicine specialists investigating the preferred management of contaminated anterior cruciate ligament grafts. Arthroscopy. 2005;21:1348-1353.

4. Van Huyssteen AL, Bracey DJ. Chlorhexadine and chondrolysis in the knee. J Bone Joint Surg Br. 1999;81-B:995-996.

In my humble opinion we should distinguish what we consider basic arthroscopic surgery and arthroscopic surgery with high specialization , for many years as head of a Department of Orthopaedic Surgery and Traumatology of a University Hospital , with specialized sections in different pathologies , my opinion is that during training as a specialist, the medical trainee should know the basic techniques of arthroscopic of knee surgery ( meniscectomy , biopsy, synovectomy ) and to know shoulder entrance gates and have the knowledge to make an acromioplasty . After the period of specialization a time of special training and a long learning curve is absolutely necessary to perform more complex techniques in knee and shoulder , or be able to perform arthroscopic surgery of ankle , hip or wrist

I believe that to perform these techniques with a high degree of efficacy and safety , it is necessary take into acount , the category of the hospital, its technical possibilities and the demand for care prior to making the decision to initiate these

Hamstring and quadriceps force, ratio, and rate of development are interesting, but to date have only been found to play a role in female athletes for prevention of ACL injury. At least that I'm aware of in the literature.

Currently, I think the best predictors are still hop tests, effusion, and global rating score for a quick in clinic assessment. However, return to sport must be done on a person by person basis depending on the individuals goals and likelihood for re-injury (graft type, age, body mass, are good predictors).

Tibial plateau geometry is interesting, but I have never had a patient that was interested in changing their bone shape to either avoid initial or secondary ACL injury. Therefore, this as a risk factor for possible interventions does not appear to be fruitful at this point.

Thoughts?

Dear Philipp

Last month, knee surgeons from the University Hospitals Leuven in Belgium announced that they had found a new knee ligament (ALL - Anterolateral Ligament), one that had not previously been specifically identified despite untold numbers of past knee dissections and scans. This surprising announcement, in The Journal of Anatomy, should improve our understanding of how the knee works and why some knee surgeries disappoint and also underscores the continually astonishing complexity of human anatomy.

The orthopedic surgeons Dr. Steven Claes and Dr. Johann Bellemans and their colleagues gathered 41 knee joints from human cadavers and began minutely dissecting them.Positioned at the front of the knee, it would be vulnerable to tearing when an A.C.L. was injured; the same forces would move through both ligaments. In my opinion more studies are needed to determine the real importance of this ligament

I do not know the SANE score in detail but I just had a look on the publication of which to probably refer to concerning the correlation coefficient. I also consider 0.66 is more a moderate correlation than a strong correlation and I agree with David that the purpose of your evaluation is probably important. SANE might be attractive when evaluating a huge cohort of patients .... If you are planning a scientific study including a reasonable amount of patients, I would definitely go with the more traditional scores ... what is also interesting in the SANE paper is, that the correlation in the ACL reconstruction subgroup was lower compared to the overall knee arthroscopy group ...

Nagmeh,

Your general approach seems sound. Calculate reactions in lab, and then transform to the required coordinate system. This reference might be helpful in determining your joint coordinate system:

Also, a JCS doesn't necessarily have to be orthogonal, although you can choose to make it so. This will affect how you perform your transformations from JCS to LabCS at each joint, so its good to check which approach you use. This paper provides some information on both approaches:

The type of reference that contains the basic equations of motion (Netwon-Euler) you need would be an engineering textbook with applications to 3D robotics or 3D dynamics. It sounds like you already have that step figured out, though.

Hope that helps!

Sean

You should read this article which gives answers to your question. "How Sex Hormones Promote Skeletal Muscle Regeneration"

Aircast has a device called the Rolimeter (see http://www.genourob.com/de/arthrometer/7-arthrometres/44-le-rolimeter-.html) that is not very expensive and is easy to use for A-P knee laxity (i.e. drawer test). I am not sure if it would work but maybe there is a way to use it (against its dedicated purpose) for M-L laxity test.