Assignment 2: Article Critique

Essentially the paper "Knee stability assessment on anterior cruciate ligament injury: Clinical and biomedical approaches" discusses the prominence of ACL injuries in sports and the severity of such an injury to a players ability to return to their profession. The idea is that ACL injuries are very difficult to diagnose in severity and the course of action for treating such an injury is not always clear. So therefore, based upon the different diagnosing techniques discussed in the paper either operative or non-operative treatments followed by a rehabilitation program are advised to the injured patients before they can safely return to sports. This paper identifies that knee stability assessments contribute three main roles in the management model for ACL injury. First the clinical assessment provides a quick and reliable way for the diagnosis of ACL injury. Second the intra-operative assessment evaluates immediate effect of operative treatment and compares different reconstruction techniques. Finally the functional assessment acts as long term guidelines during or after rehabilitation program. Within each of these three different stages of assessment there are techniques and procedures that are performed to properly treat the ACL injury.

1. Clinical Assessment (Diagnosis of ACL injury)
(i) Lachman Test - is performed by the patient lays down supine and the knee is flexed 30 degrees. The examiner stabilizes the femur and applies an anterior force on tibia without restraining axial rotation. A positive result for a torn ACL is proprioceptive or visible anterior translation of the tibia
(ii) Pivot Shift Test - is a difficult test to perform and must be done by an experienced examiner. Knee is fully extended and then flexed to 40 degrees. A positive test is defined as the forward subluxation of tibia during sudden change in direction.
(iii) KT-1000 - this is an instrument that has been developed where the patient lies in a supine position and the knee is flexed about 20-30 degrees and the arthrometer is strapped to the tibia where it is pulled back and through the calculation of pounds of force and anterior displacement an accurate assessment of the injury can be compiled.

2. Intra-Operative Assessment (Operation treatment evaluation)
Essentially this type of assessment involves the utilization of computers, cameras and computer programs. Different navigation systems drastically improve the accuracy of surgical procedures and provides information to the surgeons. Fluoroscopic navigation and image-free navigation are both used here and with both the kinematics data in sagittal, coronal and transverse plane can accurately be measured.

3. Functional Assessment (Long term evaluation after rehabilitation)
(i) Passive and active motion - with passive motion an examiner applies force to the knee in an examination room and assessing the amount of laxity in one knee to the other. This however is not considered as an efficient method as that of active motion. During active motion the patient is required to undergo physical movements and analysis of the performance and the viewing the dynamic movement of the patients knee an accurate assessment of the recovery of the patient can be made.
(ii) Optical motion analysis with reflective skin marker - in this procedure three high-speed cameras are set up with fifteen markers stuck on to the lower extremities. Here the patient is asked to do a series of movements that require the utilization of the ACL for proper movement. After the films are reviewed and analysed and an assessment on patient recovery can be made.
(iii) Dynamic Movement - the patient is requested to undergo a series of rigorous motions that would put stress on the ACL if a comfortable completion of these movements is attained then the patient is subsequently cleared to return to sporting activities.

Conclusion
In essence the paper itself investigates each method for ACL injury assessment protocols thoroughly and shows how each has its negatives and positives. The idea that many different techniques are available for the diagnosis of such a prolific injury is understandable due to many athletes who depend on the proper diagnosis and treatment due to this area of medicine having such a profound affect on their careers. The article gives testament to the technology and the advances in sports medicine. Essentially if an individual is interested in investigating diagnosis of ACL injuries at different stages of the injury this paper would be sufficient.

References
Mak-Ham, L., Fong, D., (2009), Knee stability assessment on anterior cruciate ligament injury: Clinical and biomechanical approaches, Sports Med Arthrosc Rehabil Ther Technol. doi: 10.1186/1758-2555-1-20

The Human Knee Ligaments

The Knee

Essentially the human knee is a hinge joint in the human leg connecting the tibia and fibula with the femur and protected in front by the patella. Within the knee itself a vast connection of muscles, cartilage, tendons and ligaments are surrounded by synovial fluid. The human knee is an important aspect of human anatomy in the sense that it is a staple component of locomotion that controls direction and stability, while at the same time providing ample shock absorption with ground reaction force that can be three times body weight.




















Figure 1. Diagram of the human knee


Ligaments

In essence ligaments are a band of tough, fibrous dense regular connective tissue comprised of attenuated collagenous fibers that connects bones to other bones. Ligaments are crucial to the operation in different joints of the body but particularly important in the human knee joint. The human knee consists of eleven different types of ligaments each with it's own important aspect of providing stability and connection. These ligaments are classified either as being Intracapular (within the knee cap/patella) or Extracapular (outside of knee cap/patella)


Intracapular Ligaments

1. Anterior Cruciate Ligament: is a band of dense connective which courses the femur to the tibia in the center of the knee. It is important in limiting the rotation as well as backward motion of the tibia. A fun fact about the ACL is that its injury accounts for 40% of all sports injury.

















Fig 2. Low Power View of cruciate ligament

Fig 3. Cross section of Ligament

2. Posterior Cruciate Ligament: it connects the femur and the tibia and limits the forward motion of the tibia in the center of the knee.

3. Transverse Ligament: this is a ligament of the knee that is responsible for connecting the anterior end of the medial meniscus to the anterior convex margin of the lateral meniscus

4. Posterior Meniscofemoral Ligament: is a small collagen fiber band in the knee joint. It attaches to the posterior area of the lateral meniscus and crosses superiorly and medially behind the Posterior cruciate ligament to attach to the medial condyle of the femur

5. Anterior Meniscofemoral Ligament: is a small fibrous band of the knee joint. It arises from the posterior aspect of the lateral meniscus and passes superiorly and medially in front of the posterior cruciate ligament to attach to the anterior cruciate ligament

6. Meniscotibial Ligament: is responsible for the periphery of the ibial plateus to connect to the inferior edges of the fibrocartilagenous menisci inside joint capsule


Extracapular Ligaments

1. Patellar Ligament: a strong flat ligamentous band that connects the patella to the tuberosity of the tibia

2. Medial Collateral Ligament: this ligament runs down the inside of knee joint and connects femur to the tibia and limits the sideways motion of the knee. It consists of three groups of fibers with one stretching between the two bones, and two fused with the medial meniscus.

3. Lateral Collateral Ligament: it runs on the outside of the knee and connects the lateral epicondyle of the femur to the head of fibula. It is responsible for limiting the sideways motion of the knee from inside bending force (Varus force).

4. Oblique Popliteal Ligament: located on the dorsal side of knee; it is a broad, flat fibrous band that connects upper margin of the intercondyloid fossa and posterior surface of the femur

5. Arcuate Popliteal Ligament: is a Y-shaped ligament that extends from the head of the
fibula into the capsule


Injury

The possibility of injury to a ligament of the knee increases as the level of activity rises. The tearing of ligaments is a common occurrence in sports. The most common of them all is that of a torn ACL which accounts for approximately one fifth of all sports knee injuries. Ligament tears are designated into three categories:

1. First degree tears are partial longitudinal tears of the tendon

2. Second degree tears which are also partial tears but are of a higher severity

3. Third degree tears which are complete tears of a ligament and result in higher complications and pain levels.

Fig 4: Normal ACL versus torn ACL

Stretching of ligaments is also an issue of concern especially for athletes. If a joint is dislocated and not inserted back in place then this can result in a stretching of the ligaments making individuals more susceptible to future dislocations of that particular joint. Some individuals have a higher level of elasticity than others in their ligaments and this results in what is referred to as hyperlaxity (Double Jointed).

References:

Mak-Ham, L., Fong, D., (2009), Knee stability assessment on anterior cruciate ligament injury: Clinical and biomechanical approaches, Sports Med Arthrosc Rehabil Ther Technol. doi: 10.1186/1758-2555-1-20

Figure 1: https://meded-portal.ucsd.edu/isp/2006/knee/images/Knee4.jpg

Figure 2: http://www.drbraceco.com/images/Collateral-Ligaments.jpg

Figure 3: http://neuromedia.neurobio.ucla.edu/campbell/connective_tissue/wp_images%5C142_ligament_TS.gif

Figure 4: http://www.ontheroadwithdavid.com/OnTheRoad/Knee/TornACL.jpg