Knee Pathologies Flashcards
Prevalence ACL sprains/tears
- ACL tear > common than PCL because ACL more vulnerable - has thinner fibre bundles and smaller attachment
- ACL most commonly injured in 15-25 age group participating in pivoting sports;
- Women > men
- Other structures are commonly involved in ACL tears: Meniscal tears, Articular cartilage damage, MCL injury, Bone bruising, (O’Donaghue unhappy triad = sprain injury thought to most likely injure the 3 structures: ACL, L meniscus, MCL)
Types of Apohysitis
Osgood Schlatter Disease = Apophysitis occurring at tibial tubercle
Sinding-Larsen-Johansson Syndrome = Apophysitis occurring at patella tendon attachment at apex of patella
Sever’s Disease = Apophysitis occurring at Achille’s tendon attachment on the middle facet of the calcaneus
Meniscal Anatomy
Menisci situated between corresponding femoral condyle and tibial plataeu Meniscofemoral ligaments (Humphrey and Wrisberg), attach the meniscus to the femur. The menisci are attached to each other via the transverse ligament. The horn attachments connect the tibial plateau to the meniscus. Lateral meniscus is more mobile than the medial meniscus as there is no attachment to the LCL or joint capsule Medial meniscus is more commonly injured because it is attached to the medial joint capsule and deeper fibres of MCL and therefore less mobile
General factors influencing PFP (AKP)
Split into two categories and assess for both; if structural
look at what we can do. Obviously can’t treat structural except with orthoses but can alter functional problems. Think of training errors
Functional:
Muscle length/strength
Stability
Proprioception
Structural:
Bony alignment
Patella shape
Trochlear shape
Foot position
Management of Meniscal Injuries
Previous sole treatment involved surgically removing meniscal tears. However, discovered this results in the gradual development of osteoarthritis of the knee OR those already w/ OA = it is associated w/ increased risk of progression of OA of the knee
Hence, the current management strategies in repairing meniscus-related lesions is to maintain the tissue intact whenever possible by conservative treatment
Prevalence of AKP
More common in adolescence (teens); may be seen in older ages
What are the lateral supporting structures of the knee
Anterolateral stabilisation = LCL, ITB, Joint capsule
Posterolateral stabilisation = Popliteal, biceps femoris, lateral head gastrocnemius tendons + various other structures
Pathology of Meniscal Injuries
Usually involves components of flexion and rotational forces under compression e.g. twisting, squatting or cutting manoeuvres (football).
If patient describes pain during these movements look for in an assessment:
Joint line tenderness
Joint effusion - swelling
Stress # for female athletes
Female athletes developing Relative Energy Deficiency Syndrome (REDS)/ Female Athlete Triad
Risk factors: in teens-20s, High levels of exercise and eating insufficient nutrients to accommodate exercise levels, increasing risk of lowering BMD thus greater risk of stress #
Signs: Low body fat, menstrual cycle stopped/dysfunctional, Previous #, high levels of exercise
MOI of PCL strains/tears
MOI =Posterior force to the proximal tibia.
If combined with a rotational force injury to P-L complex can occur
Mainly from car accidents - knee hits dashboard resulting in neck of femur # and/or subluxation of the hip joint; PCL rupture/strain tends to be overlooked due to the more severe injuries
Pathology of Patella tendinosis
Alterations to Tendon cell population – increased number of tenocytes, increased tenoctye metabolism, increased immature tenocytes, increased rates of apoptosis, immunoactive cells.
Disorganisation of collagen, reduction type I collagen, disorganised areas with higher concentrations of immature collagen bundles (increased type III).
Ground substance changes– PG and GAG content alters, increased H2O, chemical alterations – substance P, Glutamate and lactate.
Neovascularization – influx of blood vessels into the anterior surface and mid substance this is associated with various nerve fibres ingrowing into the tendon
Prevalence of Avulsion Injuries
May not be able to surgically repair tendons that have avulsion injuries for a prolonged period
More common in adolescents involved in sports because the tendons are stronger than apophyses (where tendon attached to bone) - because in adolescents bone have yet to fully ossify
Prevalence of Meniscal Injuries
Meniscus lesions most common intra-articular knee injury - injuries inside knee joint capsule
Most common in athletic young patients - sports-related injuries take >1/3 of all cases
Old adults meniscal tear may be caused by degeneration of the joint - may come about by a gradual or sudden onset
Medial injured more frequently 5:1 ratio to lateral
81% meniscal tears are located posteriorly.
Often associated with ACL tears (60% of cases)
Most patients do not require a MRI scan - if they do = 95% cases picked up; 5% not picked up
Define Patellofemoral Joint Pain
AKA Anterior Knee Pain (AKP) - Umbrella term to cover pain over the anterior of the knee joint
Indicates no distinction can be made to a specific structure
PFJ disorders:
○ Patella femoral pain syndrome ○ Mal-tracking ○ Dislocation ○ Chondromalacia patella
○ Patella tendinosis
○ Prepatellar bursitis
Clinical presentation of ankle LCL sprains
PC:
Pain/tenderness, swelling local to lat ligt. Esp. ATFL and/or bruising - in more mod-severe cases (ATFL>CFL>PTFL)
Aggravated - Walking or running over uneven ground, Turning sharply, Landing on inverted ankle
Severe/Moderate tears Grade II-III pain on WB, walking and most movements of the ankle
HPC/Previous episodes:
Traumatic = specific injury involving ankle inversion (MOI)
Sudden onset
Can be recurrent
SQs:
Giving way
Swelling- onset or recurrent
Walking over uneven ground
SH:
Sport involving rotation/turning eg. football, rugby, hockey!
Special tests: Anterior drawer test = ATFL injury
Talar tilt test = CFL injury (+ve)
Muscle spasm
Inability bear weight - may indicate # present
Ottawa ankle rules - used to determine if a X-ray is necessary:
Look for pain on weight-bearing at the distal end of fibula and posterior edge of L malleolus and likewise pain on distal 2-3” tibia just proximal to M malleolus
Look for pain on navicular and 5th MT and inability to weight-bear
Site of symptoms may not be diagnostic – multitude of other injuries such as peroneal tendon strains, neural irritation, OCDs, syndesmotic ligament tears, osteochondral lesions of the talus, occult stress fractures, synovitis, adhesions, intra-articular loose bodies, chronic instability, anterolateral impingement, and peroneal tendon pathology
Prevalence of PCL strains/tears
Up to 60% of PCL tears have associated posterolateral complex injuries
PCL tears account for up to 40% of ligament injuries in acute haemarthrosis
Meniscal injury with PCL injury is uncommon
4 radiographic stages of maturation of apophysis
- Cartilaginous (0-11 years)
- Apophyseal (11-14 years)
- Epiphyseal (14-18 years), during which the epiphysis and apophysis coalesce
- Bony (> 18 years)
Difference in signs of quadriceps tendon and patella tendon ruptures
Patella tendon rupture also seen by patella gliding more superior than normal
Pathology of ACL sprains/tears
Intra-articular (good blood supply); extrasynovial structure.
Proximal part has greater vascularity.
Comprised of 2 bundles = Anteromedial (AMB); posterolateral (PLB).
○ AMB restrains anterior tibia translation at > 45 of knee flexion
○ PLB shown to be more important restrain toward full extension.
Substantial number of partial tears (difficult to diagnose) progress to complete tears with a higher rate of meniscal and cartilage injuries
ACL rupture = bleeding occurs (hemarthrosis) - large swelling, typically a couple hours from onset
