-15% of all sports injuries involve the knee and 50% of all knee injuries result in a visit to the doctors; thus knee injuries cause disabilities

-75% of the surgeries on professional football players involve ligament tears, ACL tears and the meniscus

-controversy about whther astro turf fields contribute to an increase in knee injuries

Statistics for knee injuries in foot ball

and

season ending injuries

-in pro football, knee injuries acount for 23% of all injuries, but75% of surgery is for knee related problems; 1/3 of which are due to MCL tear, 1/4 for ACL tears and and 1/4 for meniscus tears

-knee injuries are the most common cause of an athlete being gone for a seson

-season ending injuries: 50% due to sprains or dislocations, 30% were due to meniscus tears, 5% due to fractures and 15% other 

3 yr study in highschool athletes 

and

knee inuries are common in all sports

-basketball had the most umber of participants and the highest inury rate

-when all sports were combined, ankle njuries were the most common, then leg then knee for males

-for females, ankle then knee then leg

-knee injuries are common in all sports: 67% skiers, 46% soccer, 43% football, 42% basketball, 38% runners, 31% gymnasts, 29% dancers, 24% tennis

Set up of knee joint

bones knee

-knee is a hinge joint but a little medial rotation of the femur occurs with full extensio. The knee is very stable, its stability comes from the geomtery of the bones, the ligaments and the muscles

-the knee is an interaction of the femur with the tibia. The patella articulates with the femur. Q angle describes the alighnment between the tibia and the femur-its an important factor in overuse injuris of the knee. People who are bowlegged have a small q angle and people who are knock kneed have a large q angle. The patella facilitates quadracept function 

Muscle groups knee

Medial stabalizers

Lateral stabilizer

-the medial stabalizers of the knee are the MCL. medial capsular ligament, medial retinaculum and the pes anserine. The MCL attatches to the medial meniscus, therefore, a co-existing injury may be present if the medial meniscus is injured.

-the lateral stabilizers of the knee are the LCL, the capsule, and the iliotibial band. Unlike the MCL, the LCL is not attatched to the lateral meniscus. Therefore, the lateral meniscus is injured only about 1/2 as much as the medial. Injuries to the medial structures are more common than to the lateral structures since you are more likely to be hit from the side (vlagus)

Posterior elements

internal strucutes 

-the poplititeal space is the well protected, diamons shaped space behind the knee through which nerves (siatic) and blood vessels (popliteal artery and vein) run. A dislocation of the knee is a serious injury because it can cause damage to the nerves and bloodvessels in the popliteal space. 

-The menesciof the knee are thin, half moon shaped cartilagenous strucutures that provide cushioning to the knee. There is both a lateral and medial meniscus in the knee. The medial menscus is thin and attatches to the MCL. The lateral meniscus is thicker and does not attatch to the LCL. The ACL attatches from the back of the femur to the front of the tibia and prevents to tibia from moving anterior relative to the femur. The PCL attatches to the front of the femur to the back of the tibia and prevents the tibia from moving posterior relative to the femur. 

initial exam for knee

identify serious injury needing immediate treatment

record details of injury

gross stabiity test

splint/first aid

transport to care

History of injury for knee

stability comes from what structures

1. the geometry of the bones

2. collateral ligaments/capsule

3. muscle groups

if any of these are deficient due to injury or due to inadequate rehab, a person will tend to have ongoing problems/disability 

Mechanisms of injury

-the strucutres injured usually depend on the tupe of force involved and the position of th lower leg at the time of injury. Common forces involve in the knee are valgus, twisting and deacceleration. 

-a valagus force injures the medial aspects of the knee

-terrible triad: medial meniscus, MCL, ACL

-a varus force injures the lateral strucutes 

-usually a valgus force with external rotation of lower leg causes terrible triad

- a deceleration force with the leg in neutral position stresses the ACL

Collateral Ligament sprian 

-mech: direct force or external blow

-three grades:

1. some fibers torn but the stability of the ligaments are intact; pain, milddisability, tenderness over the medial strucutures, little or no swelling

2. enough fibers are torn to cause instability; more pain, more disbility, local tenderness, swelling common, moderate loss of function

3. complete disruption of the ligaments: can be painless or painful; loss of function

-diagnosis: clinical exam

-treatment: non surgical-surgeries are done mostly in conjunction with the repair of other structures in the knee 

-rehab: restore stability, strength and mobility

-grade 1 takes 4 weeks to heal and grade 1 and 3 take 2-3 months 

Meniscus Injury (And anatomy) 

-anatomy and function: the menici are made of cartilidge and colagen and have a limited blood supply (and therefore limited healing capacity). the menisci not only act as a cushion between the femur and the tibia but they also act as stabiizers for the bones and allow for proper movement/tracking between the fibula and tibia. The menici also have anutrional function because they allow synovial fluid to flow up and around the knee

-mech: external force or twisting movement causign a tear

-symptoms: effusion/swelling; locking; joint line tenderness over the MCL (since the medial meniscus is attatched to it), quad atrophy(especialy vastus medialis), sensation of giving way; abnormal sound 

-diagnosis: clinical exam; MRI for conformatio. You can also use arthroscopy if necessary (high sensitivity, specificity and PV) 

-treatment: depends on the activity of the person and how much of a problem the injury is to the person. Some people can function fine without a meniscus repair

likelihood of a coexisting injury

- a study done on acute knee injuries requiring surgery found that the likely causes were: 80% medial meniscus 70% ACL, 30% lateral meniscus injury (these number don't add up to100% because when one strucutre is injured it is usually with something else.)

-another study done on ACL tears found that when an ACL tear is present, the likelihood that something else is injured is: 60% medial meniscus, 30% lateral meniscus, 23% both 

Anterior Cruciate ligament injury and anatomy

-anatomy: the ACL lies inside the knee joint. It has poor blood supply 

-mech: valgus, twisting, deacelleration

-history: the most common history of ACL injury is a bad sound, with immediate disability and immediate swelling (indicates blood in joint) 

-diagnosis: clinical exam/mri

-treatment options:ACL tears can be surgcally repaired (reconstructed). However, surgical repairs may have long term effects on the joint-there is more evidence of premature arthritic changes in people with an ACL repair. Nevertheless, there are also concerns about treating ACL tears non surgically since 20% of those with an unrepaired ACL suffer from meniscus injury within 5 yeats

-surgical considerations: if surgical reconstruction is the mode of treatment being sought, it is important to wait 4-6 weeks before doing the procedure so that the patient can get full range of motion back and therefore speedy recovery. 

Factors that might be considered when considering surgery for acl

risk levels

-age of patient, activity level, are other structures injuried, what is the person's sport specific degree of involvement? Is using a brace possible?, is itpossible to identify subjects who will do well without surgery

1. sports that involve jumping, pivoting, cutting, deceleration (basketball, football, soccer) ad that put the ACL and meniscus under a lot of stress. do repair

2. sports that involve lateral motion (baseball, raquetball, skiing). can do surgery or rehab

3. activites that put little stress on the knee (jogging, swimming). do rehab 

-rehab likely if its a high risk sport, competitive athlete, recurrent instability, meniscus injury 

Cobtroversy for ACL

1. will the ACL reconstruction prevent or delay degenerative changes

2, what are the consequences after ACL injury, with or without surgery

3. is there any treatment for meniscal injury

4. what accounrs or gender differences in injury rates for the ACL? Are these preventible?

5. surgcal issues: choice of graft, placement and attatchment of graft, rehad after surgery

Gender differences in ACL injury

-college female athletes have 2-4 times the risk of ACL injury in soccer, volleyball, basketball. Theroeis include:

estrogen receptors found in the ACL

femoral notch geometry (ACL passes through this notch)

muscle firing patterns

surgical methods and considerations

predictors of need for surgery

longterm consequences

-graft selection, graft placement, graft fixation, rehab

when to return to sport

graft strength over time

intercondyl notch: make wide to give ACL more room

-hours per year of level I or II sports, degree of displacement tibia:fibula, frequent instability

-meniscal tear, degeneratibe arthritis, impaired function of knee, gait changes 

Graft options for ACL

1. patella tendon: although its a tendon it will begin to look and act like a ligament

2. hamstring tendon

3. cadavor ACL 

Outcomes of Anterior Cruciate Ligament Injuries to Running Backs and Wide Receivers in the National Football League

Purpose: To quantify the affect ACL injuries on professional football player performance.Methods: ACL injury data from the National Football League were collected during a 5-year period  for running backs and wide receivers. A control group consisted of all running backs and wide receivers without an identified ACL who competedResults: Data were analyzed for 31 running backs and wide receivers with 33 anterior cruciate ligament injuries. 21% injured unable to participate at professional level. avg time to return to play was 55 weeks. They had 33% the qualty/performace when returned to play. Conclusion: Nearly four fifths of National Football League running backs and wide receivers who sustain an anterior cruciate ligament injury return to play in a game. On return to competition, player performance of injured players is reduced by one third.

PCL injury

Arthroscopy

-isolated injury: knee pain 50%

-patellofemoral pain 50%

arthritis risk?

surgical Rx varies

-arthroscopy: knee>shoulder>other

Patellofemoral syndrome (1)

-involves interaction between the knee cap and the bones underneath. It has been called chondromalacia (which means softening of the cartilidge but this may refere to a condition in which the cartilidge is just inflammed so its not soft, just irritated), patellar sublaxation or anterior knee pain

-for the most part, this syndrome is an overuse injury in a sport where someone does some repetitive motion involving bending jumping and straitening the knee like running, jumping, volleyballl, basketball, crew and cycling...sports where you bend and straiten your knee against resistance 

Patelofemoral syndrome (2)

-overuse njuries can be defined as mcrotrauma due to repitition, just the repeated stress of exercise causing small areas of tisuse inflammation. When evaluatin these problms, several contributing factors need attention: 

1. anatomy: is there anything about your buld that is contributing to the problem, such as high arches, flat feet, unequal leg length; anatomical problems rhat make you prone to this disorder are: a large Q angle, weakness of the vastus meadialism tight lateral ligaments tending to pull the patella to the side, shallow anatomy of the groove on the femur (if the fit is not good, the patella can easily displace to one side or the other) 

2. equipment: are the shoes you are wearing worn out, or not the right ones for your feet

3. training: are you running too many miles, too many hills, too much time on hard surfaces 

Patellofemoral syndrome (3)

-some people re prone to it becuase of certain anatomical factors (ie the knee cap is suposed to be right in the midline and there are some structures that pull it lateraly and some pull it medially, if there is an imbalance there is potential for a problem

-its an overuse injury

-diagnosis: talk to them to see what bothers them, find out what kind of activites they have been doing; stair usually bother them ( quad contraction pulls on the patella more); Examine the knee: you will usually find pain with gentle compression of the patella-compressing the patella against the knee causes an irritation to that cartilage or they may have tenderness in the quads tendon or patella tendon or on the cartilage on either side of the knee cap; if you move the knee cap from side to side, its going to hurt if the person has patellofemoral inflammation so you will find pain with various clinical exams 

Patellofemoral syndrome (4)

Patellar tendinitis

Patelar sublaxation and patellar dislocation

-patellar sublaxation: a partial dislocation with the patella somewhat displaced to the side

-patellar dislocation: it is a sudden severe, diablng injury where the medial structures are torn. It may be caused by a strong quadricep conteaction where the lateral forces ivercomes the medial restraints which are the medial ligaments and the vastus medialis

-with dislocation there is usally a coexisting internal injury. Often the force is strong enough to pull a peice of cartilage off on the backside of the patella or to pull of or chip a bone. This large force can cause a loose body floating around in the joint that needs to be treated usually by arthroscopy or surgical repair. 

Bursitis 

-a bursistis is a traumatis injury usally resulting from a direct blow resulting in inflammation of the bursa

-diagnosis: one diagnostic consideration is that you want to make sure it is not an infected bursa requiring trtment for infection rather than inflammation

-treatment: standard anti-inflammatory measures

General Rehab of the knee

-main rule: damage tissues need tme toheal. Things that take time to develop or injuries caused by a large force do not go away quickly. Acut pain and swelling need to subside before the person can participate in an active rehab process.

-inflammation of the knee is treated by rice, anti-inflammatory measures, PT

-goals: you want to maintain flexibility and moblity of the joint, restore strength and function and restor activity. If the injury is severe enough, you may need to suggest other activities that are just as satisfying and halthy.

-fix biomechanical factors 

Lower leg anatomy

-bones: tibia, fibula, talus

-muscles: 3 anatomic compartments (anterior, posterior, lateral)

Training errors and anatomical factors contributing to lower leg injuries

1. training errors (contributes to 2/3 of lower leg injuries): a) surface: may be too firm (asphalt) as opposed to something softer like grass b)shoes: provide stability and shock absorption; shoes have to be suited for the sport and have corrct properties for an individual c)excess mileage/distance d)rapid change in workouts (distance or intesnity) e) hills: downhillis extremely hard on lower extremeties because of chock absorption is somewhat transferred into forward motion type of activity 

2. Anatomical factors (contributes to1/3 of injuries): a) leg length difference: 2 cm or more is significant b) Q-angle problems: Q angle is exaggerated c)tibial torsion: causes foot to point in or out d)feet: high or flat arches 

muscle cramps

unknowen cause (maybe dehydration)

releive with stretching, massage , ice

anterior compartment syndrom

-tight anatomical space with lots of blood vessels and muscles packed in

-cause: direct blow casing internal bleeding in muscle tissue; this causes a buildup of pressure which can threaten nerve and muscle function; emergendy situation

-symptoms: dehabilitting pain and swelling with tenderness over the area. May not see bruise or blood but on the clinical exm, muscles may feel tight, look swollen (Can compare to other foot); get a foot drop and they can;t dorsiflex or raise foot

-Rx: surgery to decompress area and relieve pressure to prevent permanent damage 

posterior tibial syndrome 

-shin splints: inflammation along the medial aspect of the tibia on the lower third of the leg causing local pain 

-can use an x-ray to distinguish from a stress fracture or a bone scan if its urgen to clarify

-treatment: reduce impact since its usually due to an overuse repetition activity: reduce mileage, get new shoes, orthotics, standard antiinflmmatory measures 

achilles tendonitis

achilles rupture

1. runners and jumpers suffer from this. It's pain and tightness in this area; tight muscles, foot anatomy, repetitive stress

-treatment: anti-inflammatory measures, modify training errors

2. can't plantar flex: go up on toes, walk or run

-usually described as feeling a snap, pop, tear

-Rx: surgery with long rehab ( months recovery) 

muscle strains

stress fracutures

1. muscle strains in gastrocnemius and plantaris: these tear resulting from an ordinary situation like landing from a jump

-exam: large bruise with localized tenderness, must be distinhuished from torn achilles

-treatment: immobilizarion, cast for severe cases

-rehab: heal lifts, gradual rehab

2. can be slow to heal; alternative low impact activity may be permited 

Dietary studies

-focus on diet and weight loss

-compare different diets

- a lot of participants drop out showing that diets are hard to follow

-see only short term changes

-only lose 10 pounds on diet for a year

 cow palace rave

-hospitals were overwhelmed and activated their disaster repionse program

-4 pateints critically ill (seizures, temps as high as 107), 3 had multiple organ fialures, 2 deaths; 16 taken away by ambulance

-rave had 16,000 atendees

-police arrested 68 adults and five juveniles for allegedly possessing or selling drugs

Ecstacy

3,4-Methylenedioxymethamphetamine

-psychoactive drug

-produces increase E, people feel warm, distors time, perception and tactile xperiences

-acts through serotonin channels in the brain: serotonin regulates mood, sexual acitvity, sleep and pain sensitivity

-can be harmful for the brain: causes damage to serotonin nerves receptors

-addictive: 43% who tried it became addicted

-can interfere with bodies ability to regulate temp and can cause shutdown of major organs

Medscisports study on sterior use

-internet study that had 500 people who used steriods fill out online questionaire

-99% were male, 99% used injectible form

-unsafe practices: 13% reuse needles, 8% shared multidose viles, 1% shared needles

-where receive drugs: 7% from internet, 20% from gym member of dealer, 12% from physician

-side effects were reported by 99% of people 70% reported 3 or more side effects: 64% testicular atrophy, 63% acne, 52% fluid retention, 51% insomnia

-a large percentage used other drugs as well

-respondents age: 30% between 18-24, 28% 25-30, 22% 31-35

-78% were non competitive body builders or non athletes

-26% started before age 20

-7% sought medical care for complications, 5% suffered legal consequences, 12% had relationships suffer

-health attitudes: 61% concerned aboiut detrimental affects, 64% got health or lab checks to look for toxicity, 92% prefer to use drugs legaly with medical supervision

Balco scandal

he Bay Area Laboratory Cooperative was a San Francisco Bay Areasteroids to Major League Baseball business accused of supplying players.

-developed 2 molecules that were unable to be detected

-someone turned in one of the needles

-people got convicted

When Food Becomes A Drug: Nonanabolic Nutritional Supplement Use in Athletes

When Food Becomes A Drug: Nonanabolic Nutritional Supplement Use in Athletes: actual study

When Food Becomes A Drug: Nonanabolic Nutritional Supplement Use in Athletes: advertising

When Food Becomes A Drug: Nonanabolic Nutritional Supplement Use in Athletes: most commonly used supplements

Methods Participants in the 2002 Boston Marathon were recruited one or two days before the race. After the race, runners provided a blood sample and completed a questionnaire detailing their fluid consumption and urine output during the race. Prerace and postrace weights were recorded. 

Results Of 766 runners enrolled, 13% had hyponatremia, 0.6% had critical hyponatremia .hyponatremia was associated with substantial weight gain, consumption of more than 3 liters of fluids during the race, consumption of fluids every mile, a racing time of >4:00 hours, female sex, and low body-mass index. 

 Eight elite cyclists were studied at sea level, and after 1, 7, 14  and 21  days of exposure to 2340 m. Capillary blood samples were taken on these days before performing two consecutive maximal exercise trials. Acclimatization increased hemoglobin concentration and arterial oxygen content. On Day 1, ̇O_2max and time to exhaustion decreased by 13% and 26% , respectively and a max power decline by 14%. Subsequently, these parameters increased between days 7 and 14. These data suggest that endurance athletes competing at altitudes around 2340 m should expose themselves to this altitude at least 14 days before competition.

The Effectiveness of a Balance Training Intervention in Reducing the Incidence of Noncontact Ankle Sprains in High School Football Players

Background: A high BMI and previous ankle sprains have been shown to increase the risk of sustaining noncontact inversion ankle sprains in high school football players.

Methods: Height, body mass, history of previous ankle sprains, and current ankle brace/tape use were documented at the beginning of preseason training in 2 high school varsity football teams for 3 consecutive years (175 player-seasons). Players were categorized as minimal risk, low risk, moderate risk, and high risk based on the history of previous ankle sprain and body mass index. Players in the low-, moderate-, and high-risk groups (ie, any player with a high body mass index and/or a previous ankle sprain) Postintervention injury incidence was compared with preintervention incidence (107 players-seasons) for players with increased risk.

Results: Injury incidence for players with increased risk was 2.2 injuries per 1000 exposures before the intervention and 0.5  after the intervention. This represents a 77% reduction in injury incidence

Conclusion: The increased risk of a noncontact inversion ankle sprain associated with a high body mass index and a previous ankle sprain was eliminated by the balance training intervention.

Risk Factors for Noncontact Ankle Sprains in High School Football Players: The Role of Previous Ankle Sprains and Body Mass Index

Hypothesis: A high BMI and a history of a previous ankle sprain increase the risk of a subsequent noncontact sprain.

Methods: 152 athletes from 4 football teams were observed. Before each season, body mass, height, history of previous ankle sprains, and ankle tape or brace use were recorded.

Results: There were 24 ankle sprains, of which 15 were noncontact inversion sprains. Injury incidence was higher in athletes with previous ankle injuries. Body mass index was also a risk factor: injury incidence was 0.52 for players with a normal body mass index, 1.05 for players at risk of overweight, and 2.03 for overweight players. Injury incidence was 0.22 for normal-weight players with no previous ankle sprain compared with 4.27 for overweight players who had a previous sprain.

Conclusion: An overweight player who had a previous ankle sprain was 19 times more likely to sustain a noncontact ankle sprain than was a normal-weight player with no previous ankle sprain.

Clinical Relevance: Ankle sprain prevention strategies should be targeted at football players with a high body mass index and a history of previous ankle sprains.