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Medial Collateral Ligament Sprain
Lateral Collateral Ligament Sprain
Anterior Cruciate Ligament Sprain
Posterior Cruciate Ligament Sprain
Syndesmosis Sprain
Joint Contusion
Perineal Nerve Contusion
Meniscal Lesion
Knee Plica
Osteochondritis Knee Fracture
Osteochondritis dissecans
loose bodies Within The Knee
Patellar fracture
Patellofemoral Stress Syndromes
Osgood-Schlatter Disease and Larsen-Johansson Disease
Patellar Tendinitis
Patellar Tendon rupture
Acute Patellar Subluxation and Dislocation
Injury to the Infrapatellar Fat Pad
Chondromalacia Patella
Runner's Knee

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      - Ligament injuries of the knee can occur in combination 
 or in isolation. Depending on the application of the forces, 
 a ligament injury can occur from a direct force, a rotary force, 
 or a combination of the two. 
      - The majority of knee sprains can affect the MCL from 
 either a: 
             1. direct blow to the lateral aspect of the knee or 
             2.  from a forceful outward twist. 
      - The MCL has fibers that connect to the medial meniscus, 
 so injury to the MCL can also damage the meniscus structure. 
      - The LCL, on the other hand, does not have fibers 
 that connect to the lateral meniscus, so when the LCL is 
 damaged, the meniscus is usually in tact. 
      - This is why injuries to the MCL are more severe than 
 injuries to the LCL. 
      - Some medical authorities suggest 
 that a torn meniscus seldom occurs as a result of 
 initial trauma, rather resulting from past trauma to 
 the MCL.  
      - MCL sprains vary in degree: 
              a. depending on the position of 
               the knee at the time of injury, 
              b. past  injuries to the knee, 
              c. the strength of the muscles crossing 
               the joint, 
              d. the force and angle of trauma,
              e.  fixation of the foot, and 
              f. conditions of the playing surface. 

       - Full extension of the knee tightens both 
 the MCL and the LCL and is the most stable position 
 of the knee. 

       - Full flexion is the most unstable position for the knee. 
       - In general, instability increases as flexion increases. 
       - In full flexion, the LCL is very unstable, while the MCL 
 still provides some strong stability to the knee joint. 
 Suffice to say, the MCL is the primary stabilizer of the knee
 in knee joint flexion. 
      - Mild or moderate strains to the knee can leave the 
 structure relatively unstable and can increase the probability 
 of injury. 
      - The force and the angle of the trauma determine the 
 location and degree of the trauma incurred. 


    Grade 1 Medial Collateral Ligament Sprain 
               – In a grade 1 sprain, a few ligamentous fibers 
              are torn or stretched. 
               -  However, the joint still remains 
              stable, with little to no joint effusion 
              (fluid accumulation). There may be some local 
              stiffness and/or point tenderness along the 
              medial aspect of the joint line  but even 
              during minor stiffness, range of motion is 
              still full. 
              - After this injury is incurred, the PRICE 
             acronym should be observed for the first 
            24 hours following trauma. 
              - Crutches can be prescribed, but this is 
            usually not the case with a grade 1. 
              - Ice may be applied for 5 minutes before 
            activity for the next 48-72 hours. 
              - Knee joint rehabilitation techniques 
            should be employed at this time as well. 
              - Begin with isometric exercises until the 
            knee can be flexed without pain. 
              - Then the stationary bike can be used 
            to integrate the knee back into the kinetic 
            chain of movement. 
              -It usually takes about one to three weeks 
           for an athlete to return to normal athletic activity
          after suffering this injury. When returning to activity, 
          taping or bracing may be necessary for a short time, 
          but these methods should not be heavily relied upon 
          for preventing another injury. 
      Grade 2 Medial Collateral Ligament Sprain 
            – A grade 2 MCL sprain consists of both microscopic 
         and gross disruption of ligamentous fibers. 
            - The structures commonly involved are the MCL 
         and the medial capsular ligament. 
            - A complete tear of the deep capsular ligament 
         and a partial tear of the superficial layer of the MCL 
         or a partial tear of both areas can be present. 
            - There is usually little instability, but there will 
         be slight laxity of the knee joint in extension, 
         and increases with knee joint flexion. 
            - Swelling will be minimal unless the meniscus or
         ACL has been torn. 
            - Extensive swelling in the acute stage of a 
         grade 2 injury may indicate a torn synovial membrane, 
         subluxated or dislocated patella, or an 
         osteochondral fracture. 
            - Moderate to severe joint tightness will also
         be present.
            - The athlete will be unable to place the heel 
         flat on the ground.
            - A severe loss of range of motion will be present, 
         as well as pain on the medial aspect of the knee. 
           - PRICE should be observed immediately and last for 
          48 to 72 hours. 
           - Crutches are mandatory, as well as a three point 
         gait device until the athlete can walk without a limp.
           -  Depending on the severity of the injury, 
         a full leg cast may be necessary, but should only be
         applied for two to five days. 
           - Range of Motion exercises should begin
         immediately following the acute stages of the injury. 
           - During rehabilitation, isometric exercises, 
         especially for the quadriceps, should be conducted,
         as well as closed kinetic chain exercises. 

     Grade 3 Medial Collateral Ligament Sprain 
            – A grade 3 MCL sprain consists of a complete 
          tear of the supporting ligaments. 
            - Some signs of a complete tear include a 
          complete loss of medial stability, minimum 
          to moderate swelling, immediate and severe pain 
          followed by a dull ache, severe loss of range of 
          motion due to effusion, and positive stress tests. 
            - Isolated grade 3 MCL sprains occur when a direct
          force is applied laterally to the knee when the foot 
          is fixated. 
             - Grade 3 tears of the MCL due to a rotation 
          movement usually results in ACL and sometimes 
          PCL tears as well. 
             -  PRICE should be followed
          for twenty minutes every two hours throughout 
          the day for at least 72 hours. 
             - Surgery may be imminent, but new evidence 
          suggests that non-surgical procedures treating an 
          MCL tear where the ACL and PCL are also affected 
          may be more beneficial to knee joint stability than 
          surgical repair. 

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      - Sprain of the LCL is much less common than sprains to 
      the MCL. 
      - Varus forces with the tibia internally rotated will cause 
      this injury. 
      - A direct blow to the medial aspect of the knee is rare, 
   so it is usually indirect forces that cause the sprain. 
      - If the force is severe enough, the cruciate ligaments, 
   the iliotibial band, and the biceps femoris muscle may be torn. 
      - The meniscus structures may be damaged as well. 
      - Avulsion fractures can occur on the femur or the tibia, 
   and sometimes on the fibula via a combined pull of the 
    LCL and the biceps femoris on the head of the fibula.  
     - The collateral ligaments are so strong that they can break 
    the bone before they tear off of it.
     - Major signs of an LCL injury:
                  a. pain and point tenderness over the LCL 
                  b.palpable deformation when the knee is 
                  flexed and internally rotated. 
                  c. Swelling and effusion will also be present 
                  over the LCL, 
                  d. joint laxity and
                  e. degrees of pain
     - An injury to the peroneal nerve may also be present, 
    causing temporary or sometimes permanent palsy. 

    common peroneal nerve
                  - originates from the sciatic nerve and lies 
    beneath the head of the fibula and winds laterally 
    around the neck of the fibula,  where it branches 
    off to form the deep and superficial peroneal nerves. 
                  -A tear of this nerve can produce weakness 
    and paralysis to the lateral aspect of the lower leg. 

     - Management of LCL sprains is nearly identical to that 
    of MCL sprains.  

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      - An ACL sprain is the most critical ligament injury in 
     the knee. 
      - When the tibia is externally rotated and the knee
     is in a valgus position, the ACL is most vulnerable.
      - The ACL can sustain an injury from a direct blow to 
     the knee when the leg is rotated while the knee is fixed. 
      - In this position, the ACL becomes taut and susceptible to 
      - Tears of the ACL, combined with injury to other 
     surrounding structures in the knee, can produce rotary 
      - Anterolateral rotary instability may involve injury to 
     the anterolateral joint capsule, the LCL, and possibly
     the PCL and structures in the posterolateral corner. 
      - Anteromedial rotary instability usually involves injury to the 
     antermedial capsule, the MCL, PCL, and posteromeidal corner. 
      - A hyperextension from a blow to the front of the knee 
     with the foot planted can tear the ACL and possibly sprain 
     the MCL. 
     - Female athletes are much more likely to suffer noncontact 
     ACL injuries than are males. 

       Extrinsic factors  include the
                    a.level of conditioning, 
                    b. skill acquisition, 
                    c. playing style, 
                    d.the amount of physical preparation and practice, 
                    e. environmental considerations, and 
                     f. types of equipment used. 
                 - These factors can be somewhat controllable  

        Intrinsic factors involve:
                    a. individual physiological and 
                    b.  psychological factors 
                               1.Femoral condyler notch size, 
                               2.ACL girth,
                               3. ACL laxity, and 
                               4.lower extremity anatomic malalignment 
       - There is no consensus on whether sex-specific 
      hormones play a role in the increased incidence of 
      ACL injury in female athletes, thus there appears to be 
      no reason to modify activity or restriction from sport of 
      female athletes at any time during the menstrual cycle.  
       - Since the ACL is intimately connected into the kinetic 
      chain, forces acting upon other body parts can have an 
      effect on the ACL. 
       - Impact on the foot or heel rather than on the toes 
      during landing from a jump or changing directions while 
      running, awkward running, and biomechanical perturbations 
      may all result in an ACL injury. 
       - Deceleration with valgus stress and rotation appears 
      to be the most common mechanism of injury to the ACL. 

      Neuromuscular factors such as:
                   a. joint stiffness, 
                   b. muscle activation latencies, and 
                   c.muscular recruitment patterns 
               - are important contributors to the increased risk 
              of ACL injuries in female athletes. 

        - Quadriceps activation during eccentric contraction is 
       also considered to be a major factor in ACL injury.  
        - As soon as injury is incurred, a pop or a snap is felt or 
       heard, followed by immediate disability. The knee will feel 
       like it is “coming apart.” 
        - Anterior cruciate ligament tears produce rapid 
       swelling at the joint line.  
        - Proprioception is also decreased following an ACL
        - Even if PRICE is followed immediately, within one to 
        two hours following the initial trauma, swelling 
        become prominent and, after six hours, notable
        hemarthrosis is present. 
        - After injury, the athlete will be unable to walk 
        without assistance. 
        - ACL injuries lead to serious knee instability. 
        - Controversy exists among physicians as to how
        to best treat an ACL rupture, and when surgery is warranted. 
        - ACL rupture will lead to severe joint degeneration. 
        - A decision for or against knee surgery must be based 
       on the athlete’s age, the type of stress applied to the
       knee, and the amount of instability present. 
        - Even a simple surgical repair of the ligament may not 
       be adequate in establishing proper joint stability. 
        - Joint reconstruction surgeries, however, are much 
       more common and much more effective. 
        - Transplantation of another ligament or tendon
      (pes anserinus, semitendonosis tendon, tensor fasciae latae, 
      or patellar tendon) is used in this procedure to replace 
      part or all of the ACL. 
              - This surgery requires three to five weeks in 
     braces and four to six months in rehabilitation.  
     It has been suggested that it may take up to two years 
     to regain normal quadriceps muscle function following an 
     ACL reconstruction. 

       - At the present time, little scientific evidence exists 
     that suggests the use of a functional knee brace, 
     however some physicians still hold to the belief that 
     bracing can provide some protection during activity.

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 - Shelbourne and colleagues refer to the PCL as being the most 
important ligament in the knee because it provides a central axis of 
 - The PCL provides roughly 90% of the total restraining force to
straight posterior displacement of the tibia. 
 - When the knee is flexed at 90 degrees, the PCL is in its most
vulnerable position.
 - A fall with weight on the anterior aspect of the bent knee with
the foot in plantar flexion or a hard blow to the front of the knee 
can cause a tear of the PCL. 
 - The PCL can also be injured by a rotational force, 
which, according to Shelbourne, causes damage to the medial or
lateral side of the knee. 

Symptoms of a posterior cruciate ligament sprain
  a.  feeling of a pop or snap in the back of the knee
  b.  tenderness and little swelling will be evident in the 
popliteal fossa
  c.  laxity will be felt during stress tests.  

 - PRICE should be implemented immediately.
 - Non-operative rehabilitation of grade 1 and grade 2 injuries must 
    focus on quadriceps strengthening.
 - M. Safran et al states that there is much controversy over whether 
PCL tears should be treated operatively or non-operatively ). 
 - Satisfactory outcomes achieved by non-operative means have been 
reported. However, surgery is sometimes unavoidable.
 -  Rehabilitation following surgery often takes six weeks 
of immobilization in extension with full weight bearing on crutches.
 -  ROM exercises are begun at six weeks. 

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 - Isolated injuries to the distal tibiofemoral joint are referred 
   to as syndesmotic sprains. 
 - The anterior and posterior tibiofibular ligaments are found
   between the distal tibia and fibula and extend up the lower leg 
   as the interosseous ligament. Sprains of these ligaments appears
   to be more common than previously believed. 
 - Increased external rotation, or forced dorsi flexion may cause
   these ligaments to tear as well as causing a severe sprain of the 
   medial and lateral ligament complexes. 
 - Initial rupture of the ligaments occurs distally at the tibiofibular
   ligament, as the force of disruption is increased, the interosseous
   ligament is torn proximally. Severe pain and loss of function will 
   be present in the ankle region. 
 - The pain occurs along the anterolateral region of the leg. J. Tauton
   reminds us that sprains to the syndesmotic ligaments are extremely
   hard to treat and take months to heal. 

 - Treatments of these sprains are nearly identical to that of medial 
   or lateral sprains, however, a longer period of immobilization must 
   take place. 
 - Return to activity will take much longer than other sprains around
    the ankle.  

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	- A direct blow to any of the muscles 
	  crossing the knee joint can result in a 
	  temporarily handicapping condition.
	- One of the muscles frequently involved 
	  is the vastus medialis muscle,  which 
	  is highly involved in locking the knee in full 
	- Bruises on the vastus medialis may appear to be a knee sprain. 

	- Some of these symptoms include 
		- severe pain, 
		- loss of movement and 
		- acute inflammation. 
	- Swelling and discoloration resulting 
	  from the tearing of muscle fibers and blood vessels 
	  will indicate such an injury. 
	- If PRICE is observed immediately following
	  injury, the knee will usually return to functional 
	  use within 48-hours after the trauma was incurred. 

	- Bruising on the capsular tissue that 
	  surrounds the knee joint is associated with 
	  muscle contusions and bruises to the periosteum 
          of the bone. 

	- Traumatic force applied to the capsular tissue 
	  will cause 
		- capillary tearing and bleeding, 
		- synovial membrane irritation and 
		- profuse fluid effusion into the joint cavity, 
	 resulting in intraarticular swelling. 
 	- This effusion occurs slowly, so it 
	is often unnoticed. Scar tissue will develop eventually. 

	- Care are of this injury depends on both the exact 
          location and severity of the contusion. 
	- PRICE, along with 24 hours rest should be observed. 
	- PRICE may last up to 72-hours after the initial trauma. 
	- ROM exercises, should be introduced when the inflammation 
	- The heat modality can be introduced post 72-hours, 
	  but great caution should be used to prevent swelling. 
	- If the swelling has not resolved within a week, 
	  chronic inflammation may be present in the form 
          of either synovitis or bursitis.

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	- The peroneal nerve crosses directly behind 
	  the underlying neck of the fibula. 
	- A kick or blow to the area can cause a compression 
	  injury to  the nerve. 

	- Immediately following impact,local pain 
		- from the contusion and
		- from an electric shock will radiate down the 
		anterior portion of the lower leg and into 
		the dorsum of the foot. 

	- Paresthesia and numbness along the distribution 
	  of the nerve will also be present. 
	- Skin abrasions and ecchymosis with tenderness 
	  of the underlying peroneal nerve will cause a 
	  tingling sensation, which can be relieved with 
	  local pressure.
	- Neuropraxia, will last only the first few seconds, 
	  but if the injury is severe, hypesthesia and weakness 
	  of the peroneals and dorsiflexors will persist, 
	  possibly leading to a drop foot  
	- Usually, just a  minor injury is incurred and 
	  the athlete recovers within a few days.  

	- When the injury is sustained, PRICE should be 
	  followed immediately. 
	- As soon as the symptoms are gone, the athlete can 
	  return to activity, as long as there is no weakness 
	  in the peroneals and dorsiflexors. 
	- Protective padding may be used to help protect the 
	  tender area from further injury after return to activity. 

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	- Medial meniscus is much more prone to injury
	  than the lateral meniscus because of the attachment 
	  of the coronary ligament. 

	- The lateral ligament does not attach to the
	  coronary ligament and is more mobile during knee movement. 
	- The medial meniscus is prone to disruption from valgus 
	  and torsal forces. 
	- A valgus force can cause the knee to adduct, 
	  which will tear and stretch the medial collateral ligament.
	- Its fibers twist the medial meniscus outward. 
	- Repeated mild sprains will make the athlete more prone 
	  to this injury due to a lessening of ligamentous stability. 
	- The most common mechanism of injury is weight
	  bearing combined with a rotary force,/b> while the knee  
	  is extended or flexed. 
	- Cutting motions can also cause injury to the medial meniscus.
	- Stretching of the anterior and posterior portions of the
	  meniscus can produce a vertical-longitudinal tear. 
	- The lateral meniscus can sustain an oblique tear by a 
	  forceful knee extension with the femur externally rotated.
	- Meniscal lesions can be 
		- longitudinal, 
		- oblique, or 
		- transverse 

	- Because of the blood supply (mentioned earlier), tears in 
	  the outer one-third of a meniscus may heal over 
	  time if tress in the area is kept to a minimum. 
	- Tears that occur within the midsubstance of the meniscus 
	  often fail to heal because of a lack of adequate blood 

	- Diagnosis of a meniscal legion is difficult, 
	  even for skilled sports medicine physicians. 
	- Diagnosis of the injury should be made immediately 
	  before muscle spasming and swelling obscure the normal 
	  shape of the knee. 
	- A meniscal tear may or may not result in an effusion 
	  developing gradually over 48- to 72-hours, joint-line 
	  pain and loss of motion, intermittent locking and giving 
	  way of the knee, and pain when the athlete squats.
	- Once a tear occurs, the ruptured edges harden and may 
	- Portions of the meniscus can become detached resulting 
	  in loose bodies. 
	- Chronic meniscal lesions will display recurrent swelling 
	  and obvious muscle atrophy. 
	- The athlete will have a sense of the knee “collapsing,”
	  a popping sensation, or of an inability to perform a full 
	- Such signs usually indicate the necessity of surgical 
	  intervention locked but shows indications of a tear, 
	  an MRI may be needed, as well as a diagnostic 
	  arthroscopic examination. 

	- A knee that is locked in place by a displaced meniscus 
	  needs to be unlocked with the patient under anesthesia. 
	- A portion of the meniscus may have to be removed if 
	  chronic locking occurs. 
	- Brindle states that surgical management of meniscal 
	  tears should make every effort to minimize loss of 
	  any portion of the meniscus.

	- The meniscus structures are important in 
		- shock absorption and 
		- in preventing degenerative joint disease
	- Post-surgical management for a partial 
	  manisectomy (partial removal of the meniscus) does 
	  not require bracing and allows partial to full weight 
	  bearing on crutches in about two weeks. 
	- An athlete can sometimes return to activity within 
	  six to fourteen days following surgery. 
	- A repaired meniscus, on the other hand, requires 
	  immobilization in a rehabilitative brace for five 
	  to six weeks. 
	- During immobilization, ROM exercises between 0 and 90 
	  degrees should be conducted. 
	- Rehabilitation should concentrate on endurance.  

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	- Dr. T. Blackburn notes that before birth, a child has 
	  three synovial knee cavities whose internal walls, 
	  at four months, are gradually absorbed to
	  form a single chamber; however, in roughly 20% of all 
	  individuals, the knee fails to fully absorb these cavities. 
	- In adulthood, these septa form  synovial folds known as 
	- The most common of these folds is called
	  the infrapatellar plica, which originates from the 
	  infrapatellar fat pad and extends superiorly in a fanlike 
	- The second most common synovial fold is the 
	  suprapatellar plica, located in the suprapatellar 
	- The least common, but the most subject to injury, 
	  is the  mediopatellar plica, which is bandlike and begins 
	  on the medial wall of the knee joint and extends downward 
          to insert into the synovial tissue that covers the 
	  infrapatellar fat pad. 
	- Because most synovial plicae are pliable, most are 
	  asymptomatic; however, the mediopatellar plica
	  may be thick, nonyielding, and fibrotic, causing a number 
	  of symptoms. 
	- The meadiopatellar plica is associated with chondromalacia 
	  of the medial femoral condyle and patella. 
	- If the symptoms originate after trauma, the trauma is 
	  usually a blunt force or twist when the foot is planted. 
	- Recurrent episodes of pseudolocking of the knee when the 
	  individualhas been sitting for a period of time may be 	
	  a positive indicator. 
	- As the knee passes 15 to 20 percent flexion, a snap may 
	  be felt or heard.
	- These symptoms can easily be misinterpreted as a torn 
	- However, unlike meniscal tears, there is little or no 
	  swelling and no ligamentous laxity. 
	- Rest, NSAIDs and localized heat are common ways
	  to treat knee plica. 
	- If the plica develops into chondromalacia, surgery 
	  is required.

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	- Sometimes the same mechanisms that cause collateral 
	  ligamentous, crucial ligamentous, and meniscal tears can 
	  shear off either a piece of bone attached to the anterior 
	  cartilage or the cartilage alone. 
	- Twisting, a sudden cutting motion, or a direct blow to 
	  the knee can cause such a fracture. 
	- A snap is heard and the knee gives away immediately 
	  following this injury. 
	- Swelling tends to be immediate and extensive due to 
	  hemarthrosis, and pain is very intense. 
	- Surgery must be performed to replace the fragment as soon 
	  as possible to avoid degeneration.

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	- Osteochondritis dissecans is a painful condition, 
	  which involves a partial or complete separation of a 
	  piece of articular cartilage and subchondral bone. 
	- The majority of these fragments (more than 85%) occur 
	  in the lateral portion of the medial femoral condyle. 
	- Lesions will result in normal articular cartilage with 
	  dead subchondral bone underneath separated by a layer of 
	  fibrous tissue. 
	- The cause of this condition is yet to be 
	  discovered, but it seems to have a slow onset.

	- Possible factors may include
		- either direct or 
		- indirect trauma, 
		- skeletal or endocrine abnormalities, 
		- a prominent tibial spine impinging on 
	          the medial femoral condyle, or 
		- a facet of the patella impinging on the medial 
	        femoral condyle.  

	- When osteochondritis dissecans is present, an aching 
	  sensation in the knee will be almost constant, as well 
	  as recurrent swelling, and an occasional locking sensation. 
	- Point tenderness and atrophy of the quadriceps may 
	  also be present. 
	- Immobilization and usually a cast is prescribed
	  after diagnosis. 
	- This allows for resolution of the cartilage and 
	  ossification of the underlying bone. 
	- This condition may take as long as a year to resolve, 
	  and surgery may be the best way to correct the injury. 

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	- Osteochondral fragments, or loose bodies, can develop 
	  within the joint cavity due to repeated injury to the knee. 
	- Loose bodies, also called joint mice, can stem 
		- osteochondritis dissecans,
		- menisci fragments, 
		- pieces of torn synovial tissue or 
		- a torn cruciate ligament

	- The loose body can move around in the joint and become 
	  lodged, causing a locking or popping sensation. 
	- Pain and instability may be present. 
	- If the loose body becomes lodged in between articulating 
	  surfaces, irritation will occur. 
	- Joint degeneration can occur if the loose body is not 
	  surgically removed. 

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	- Bursitis of the knee, as well as in other body regions, 
	  can be classified as 
		- acute, 
		- chronic, or 
		- recurrent. 

	- As mentioned earlier, nearly two dozen bursa sacks have 
	  been identified around the knee, however, the
	  prepatellar, deep infrapatellar, and suprapatellar bursa 
	  are the most likely to become inflamed in sports. 
	- Overuse of the patellar tendon is the most common 
	  cause of bursitis at the knee. 
	- ,b>Localized swelling will be present above the knee. 
	- Since the swelling will occur outside of the
	  joint capsule, skin discoloration and increased localized 
	- Ceasing activity that irritates the bursa, and techniques 
	  aimed to reduce inflammation (PRICE) should be used to 
	  treat bursitis. 
	- Arguably the two most important modalities for treating 
	  bursitis are the use of a compression wrap and NSAIDs. 
	- If chronic bursitis is the condition, 
	  injected antiinflammatories may be used. 

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	- Fractures of the patella are not unlike fractures of 
	  other bones in that they can occur from both direct or 
	  indirect trauma applied to the bone.
	- Most patellar fractures are acquired by indirect 
	  means consisting of a sudden and forceful pull on the 
	  patellar tendon against the femur when the knee is 
	  partially flexed. 
	- In this position, maximum stress is placed  on the bone 
	  from the quadriceps and the patellar ligament. 

	- Direct injury often produces fragmentation with little 
	  displacement. In other words, the patella is likely to 
	  crack (shatter) rather than snap. 
		- Falling,		
		- jumping, 
		- or running activities 
	        may result in a fractured patella.  

	- Side Note: 
		- Oddly enough, roughly three percent of the 
		population have what is known as a bipartite patella. 
	        - This means that the patella consists of two 
	        portions, rather than just one. 
		- When X-rayed, this condition, which is 
	        in no way harmful, can be misdiagnosed as a 
	        patellar fracture.  
		- A fractured patella causes hemorrhaging and joint 
	        effusion, which causes swelling. 
		- Indirect fractures cause 
			- a tear in the joint capsule, 
			- separation of bone fragments, 
			- and possible tearing of the quadriceps 
		- In a direct injury, little bone separation 
	        is present. 
		- The separated patellar fragments can be easily 
	        palpated, and an X-ray will confirm the extent of 
		the injury. 
		- In the acute stage, PRICE should be 
	        followed with splinting (this goes under “protection”).
		-  Immobilization for two to three months is expected.

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	- This condition results from lateral deviation of 
	  the patella as it tracks in the femoral groove 
	- W. Prentice and colleagues identified several factors 
	  that may cause lateral tracking: 
		- Tightness of the hamstrings and gastrocnemius, 
		- tightness of the lateral retinaculum (which 
		compresses the lateral facet of the patella against 
		the lateral femoral condyle), 
		- increased Q angle (angle made between the 
		head and shaft of the femur), 
		- tightness of the iliotibial band, 
		- pronation of the foot, 
		- patella alta (lengthening of the patellar tendon, 
		making it longer than the patella itself),
		-  vastus medialis oblique insufficiency 
			- caused by imbalance with the strength of 
			the vastus lateralis or by inhibition 
			resulting from the presence of 20 to 30 ml 
			of effusion in the knee, and weak hip a
			dductors to which the vastus medialis 
			oblique attaches.  
	- Tenderness on the lateral aspect of the patella will 
	  be present as well as some swelling associated with 
	  irritation of the synovium as well as 
	  reports of a dull ache in the center of the knee. 
	- Patellar compression will elicit pain and crepitus. 
	- W.R. Post cautions us that the causes 
	  underlying patellofemoral pain as identified during 
	  the evaluation process 
	  should provide the basis for treatment. 
	- A strengthening program should be started for the 
	  adductor muscles and for correcting the imbalance 
	  made between the vastus medialis oblique and the 
	  vastus lateralis through the use of biofeedback techniques. 
	- Stretching of the hamstrings, gastrocnemius and iliotibial 
	  band should also be implemented. 
	- W. Gilleard reports that foot orthotics can be used 
	  to correct pronation and other malalignments, as well 
	  as specific taping techniques. 
	- Taping can be used to help correct the orientation of 
	  the patella. In extreme cases, lateral 
	  retinacular release can be used. 

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	- These two conditions are common to adolescent athletes. 
	- Osgood-Schlatters disease is an apophysitis 
	  characterized by severe pain at the attachment of
	  the patellar tendon into the tibial tubercle. 
	- Thus, an avulsion fracture of the tibial tubercle will be 
	- The fragment starts off as being cartilaginous, 
	  but with growth a bony callus forms and the tuberosity 
	- This condition usually resolves itself once the adolescent 
	  finishes puberty, and the only remnant is an enlarged 
	- Although several mechanisms have been postulated, 
	  the most widely accepted cause of this disease is by 
	  repeated avulsion of the patellar tendon at the 
	  apophysis of the tibial tubercle. 
	- In severe cases, a complete avulsion may be present.  
	- Larsen-Johansson disease is very similar to 
	  Osgood-Schlatter disease, but it occurs 
	  at the inferior surface of the patella. 
	- The mechanisms of the onset of this disease is the same 
	  as that of Osgood-Schlatter disease. 
	- Swelling, pain, and point tenderness are all 
	  characteristics of this disease, as well as 
	  degeneration of tendonous fibers. 

	- Repeated irritation will cause 
		- swelling,
		- hemorrhage, and 
		- gradual degeneration of the apophysis 
		as a result of impaired circulation. 

	- Severe pain will be present with knee flexion, with 
	  point tenderness over the anterior proximal tibial tubercle. 
	- Management of both diseases is usually very conservative. 
	- Some treatments include 
		- a decrease in stressful activities 
	  	until epiphyseal union takes place (six months to a year), 
	  	- a cylindrical cast (in severe cases), 
		- ice applied before and after activities, and 
		- isometric strengthening of the quadriceps and 
		hamstring muscles. 

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	- Jumping, kicking and running places great 
	 stress on the knee extensor muscle complex. 
	- As a result, tendinitis can occur in the patellar 
	 tendon or quadriceps tendon. 
	- In some cases, the patellar tendon can completely 
	 ear from the bone. 
	- Chronic inflammatory conditions of the area may 
	 predispose an athlete to a tear or rupture. 
	- Tenderness and pain will be present on the 
	 inferior surface of the patella, as well as the posterior 
	- There are three stages of pain associated with patellar 
		- Stage 1 
			– Pain immediately following activity. 
		- Stage 2 
			– Pain both during and after activity, 
			but the athlete is still able to perform 
		- Stage 3 
			– Pain both during and after activity, 
			but lasting a long duration. 
			Athletic performance is compromised and 
			may progress to constant pain and 
			eventual rupture. 

	- Any pain in the patellar tendon indicates a sudden, 
	 forceful movement that would lead to the pain. 
	- J.K. Wilson states that many different approaches 
	 have been reported to treat this inflammatory 
	 condition including the 
		- use of ice, 
		- phonophoresis, 
		- iontophoresis, 
		- ultrasound, and 
		- various forms of superficial heat modalities such as
			- whirlpool coupled with a rehabilitation 
	- Bracing may also be used. 
	- G. Pellecchia reported that a deep transverse friction 
	 massage has been a successful modality of treatment 
	 for patellar tendinitis. 
	- The friction is created via a firm massage of the 
	 patellar tendon on the inferior surface
	 of the patella perpendicular to the direction of 
	 the fibers.
	-  A friction massage is actually used to increase 
           the inflammatory response as to speed healing and push 
           the body into the fibroblastic repair phase. 
	  Therefore, when the transverse friction massage modality 
	  is used, techniques designed to reduce inflammation 
	  should not be used.

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	- A rupture of the patellar tendon can be caused by a 
	 sudden and powerful contraction of the quadriceps 
	 muscle group with weight bearing. 
	- The rupture may occur in either the patellar tendon or 
	 the tendon of the quadriceps. 
	- This rupture usually only occurs during a 
	 chronic inflammatory condition of the tendons involved where
	 tissue degeneration has taken place. 
	- Ruptures, in general, rarely occur in the middle of 
	 the tendon, rather at their insertion to the bone. 
	- If the patellar tendon is ruptured, the rupture will occur 
	 on the inferior portion of the patella, whereas if 
	 the quadriceps tendon is ruptured, the rupture will occur 
	 on the superior portion of the patella. When the tendon 
	 is ruptured, it moves upward toward the thigh creating an 
	 obvious deformity. 
	- Knee extension is not possible, and there will 
	 be excessive swelling present as well as extreme 
	 initial pain followed by a minor dull ache. 
	- A rupture of the patellar tendon most likely will require 
	 surgical repair. 
	- Jumper’s knee may lead to this injury, thus proper 
	 care of that condition may reduce the risk of acquiring 
	 a rupture. 
	- Steroid users are also susceptible to this injury. 
	- Steroids injected directly into these tendons weaken 
	 collagen fibers and mask pain.

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	- Forced knee valgus can occur when the thigh rotates 
	 internally while the lower leg rotates externally 
	 (this often occurs during deceleration and 
	 cutting movements when the foot is planted). 
	- If this occurs, the quadriceps attempts to pull in a strait 
	 line, thus pulling the patella laterally which 
	 may dislocate the bone. 
	- The patella always displaces laterally under these

	- Some athletes may be prone to this injury if they have a 
	 	- wide pelvis with anteverted hips, 
		- genu valgum (which increases the Q angle), 
		- shallow femoral grooves, 
		- flat lateral femoral chondyles, 
		- flat patellas, 
		- vastus medialis and ligamentous laxity with genu 
		recurvatum and externally rotated tibialis, 
		- pronated feet and 
		- externally pointing tibias.
	- Pain, swelling and a complete loss of knee function, as 
	 well as a obvious deformity may all be present in the acute 
	 stage of injury. 
	- The dislocation must be reduces immediately  by placing 
	 mild pressure on the patella with the knee extended. 
	- The PRICE acronym should then be implemented, with 
	 emphasis on ice and splinting. 
	- If this is a first-time occurrence, a fracture may be 
	- During treatment, the knee will need to be immobilized 
	 for at least four weeks. 
	- During this period, isometric exercises can be performed. 
	- Horseshoe padding and bracing should be used upon return 
	 to activity. 
	- Muscles of the thigh and hip should be performed, 
	 especially strait leg raises. 
	- In some cases, surgery may be required.

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	- The infrapatellar fat pad 
		- aids in protection and 
		- shock absorption of the knee.
	- It lies between the synovial membrane on the anterior 
	 aspect of the joint and the patellar tendon. 
	- The infrapatellar fat pad is particularly vulnerable 
	 during athletic activity, and can be injured if wedged 
	 between the tibia and patella, irritated by chronic flexion 
	 pressures, or via a direct blow. 
	- Capillary hemorrhaging can be present due to 
	 repeated trauma and localized swelling. 
	- If the irritation continues, scaring and 
	 calcification may develop. 
	- Pain may be present below the patellar ligament
	 during knee extension, and the knee may become weak 
	 with mild swelling and stiffness.
	-  Rest from activities, which irritate the area, 
	 heel elevation, and ice modalities should be utilized 
	 to treat acute injury. 
	- Hyperextension taping may also be necessary to 
	 prevent against full extension.

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	- Chondromalacia patella is a softening and deterioration 
	 of the articular  cartilage on the backside of the patella.
	- Chondromalacia can be identified in three separate stages.
		- Stage 1 
			– Swelling and softening of the articular 
		- Stage 2 
			– Fissuring of the softened articular 
		- Stage 3
			– Deformation of the surface of the 
			articular cartilage caused by fragmenta-

	- To date, the cause of chondromalacia is unknown. 
	- Some experts suggest abnormal patellar tracking may be 
	 a factor, however individuals with normal tracking have 
	 sustained this condition, and others with abnormal tracking 
	 are free of it. 
	- Pain on the anterior aspect of the knee while walking, 
	 running, ascending and descending stairs or squatting 
	 will be present.
	- Recurrent swelling around the patella will be seen, 
	 and a grating sensation will be felt during knee flexion 
	 and extension. 
	- Palpable pain will also be present on the inferior 
	 border of the patella and when the patella is compressed 
	 within the femoral groove during passive flexion and 
	- One or more alignment deviations may also signal 
	 the presence of chondromalacia.  
	- M. Baker reported degenerative arthritis on the medial 
	 facet of the patella, which makes contact with the femur 
	 when the athlete performs a squat. 
	- Both Baker and A. Boland report that degeneration first 
	 occurs in the deeper portions of the articular cartilage, 
	 followed by blistering and fissuring that stems from the 
	 subchondral bone and appears on the surface of the patella. 
	- Conservative treatments include 
		- avoidance of activities which irritate the area, 
		- isometric exercises for the quadriceps and 
		 hamstring muscles, 
		- NSAIDs and small doses of aspirin, 
		- a knee sleeve, 
		- an orthotic device used to correct pronation and 
		 reduce tibial torsion. 

	- Boland states that if these measures fail, surgery may 
	 be the only option. 
	- Surgical procedures include 
		- moving the insertion of the vastus medialis 
	         muscle forward through realignment procedures such as 
		 	- lateral release of the retinaculum, 
			- shaving and smoothing the irregular surfaces
			 of the patella and femoral condyle, 
			- removing the blister with drilling,
			-  elevating the tibial tubercle, and as a 
			last resort completely removing the patella 

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	- Runners knee is a general term used to define overuse 
	 injuries of the knee.
	- Malalignment and structural asymmetries of the leg and 
	 foot can cause an overuse condition. 
	- Patellar tendinitis and patrellofemoral conditions 
	 may led to chondromalacia. 
	- Two conditions that are common among distance athletes 
		- iliotibial band friction syndrome and 
		- pes anserinus tendinits or bursitis. 
	- Iliotibial band friction syndrome is an overuse 
	 injury, which is common in distance athletes who have 
	 genu varum and a pronated foot. 
	- Irritation develops at the bands insertion point and on 
	 the lateral condyle of the femur. 

	- Treatment for this condition consists of 
		- stretching iliotibial band and 
		- reducing inflammation.  

	- The pes anserinus is the location where the gracilis,
	 sartorius, and semitendonosus muscles attach to the 
	- Pes anserinus tendinitis and pes anserinus bursitis 
	 go hand in hand with one another. 
	- Inflammation can result from a weak vastus medialis muscle. 
	- Running on a slope with one foot higher than the other over 
	 time can cause this condition.  
	- Alignment problems must be corrected in order to help 
	 correct this condition. 
	- Acute treatment includes ice and a deep tissue 
	 massage before and/or after activity as well as a 
	 proper warm-up with stretching. 
	- It is also important to avoid activities that 
	 aggravate the condition, such as running on an incline. 
	- NSAIDs and foot orthotics may help reduce the condition 
         as well. 

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