Knee Joint pdf - د. محمد حاتم

AFTER MID

SURGERY

DR. MOHAMMED HATIM

Orthopaedic

Knee Joint

TOTAL LECTURES 5

Dr. Mohammed

Hatim

Knee joint

Deformities of the knee:

  Normally  the  knee  is  in  5-7  degrees  of  valgus,  any  deviation  from  this  in
adults regarded as abnormal deformity; either Genu varus (medial angulation)
or  Genu  valgus  (lateral  deviation)  or  abnormal  hyperextended  knee  that  is
called Genu recurvatum.

Objectives:

1. Define variable angular deformities of the knee joint and discuss its

etiology.

2. Describe a clinical method for diagnosis, follow up and prognosis of

genu varus and valgus.

3. Discuss the management and indication of surgical intervension.

Developmental Genu varus (bow leg); Genu valgus (knock knee);

During early years of life (before 10 years) these deformities can be
regarded as normal stages of development & must be followed up frequently by
measuring the intercondylar distance for varus & the intermalullar distance for
valgus to see the severity & possible progression of the deformity.
Normal intercondylar distance is less than (6cm), if its (6-8cm) it needs
frequent follow up, if more than (8cm) it needs surgical correction.
Normal intermalullar distance is less than (8cm), if its (8-10cm) it needs follow
up, if more than (10cm) its indication for surgery.
Other indications for surgery includes:

1.  Severe deformity.
2.  Unilateral deformity.
3.  Rapidly progressive deformity.
4.  If uncorrected deformity after the age of (l0-12) years.
5.  Painful deformity.
6.  Deformity associated with joint instability or derangement.

Secondary causes of angular deformities:

1. Rickets; causing bone softening and progressive deformities with weigh

bearing, it needs treatment with vit. D.

2. Post-traumatic; with epiphysial injury & arrest, malunion or with joint

ligament injury.

3. In adults it commonly occurs with osteoarthritis (varus knee), or with

rheumatoid arthritis (valgus knee).

4. Other diseases like Paget’s disease (varus knee).

Management:

Frequent clinical assessment needed to look for progression & indication for
surgery.
Examine the knee for possible associated instability.
Take x-ray for the knee & tibia to see the state of the epiphysis & state of the
deformity.

  For patient near skeletal maturity (1-2 years) of maturity we can use stapling
(internal  fixation  with  staples)  of  the  upper  tibial  &  lower  femoral  epiphysial
plates  at  the  side  of  overgrowth  to  allow  other  side  to  grow  &  correct  the
deformity.
  If the above procedure is not applicable we do corrective osteotomy and we
should  avoid  injuring  the  nearby  epiphysis;  for  varus  deformity  we  do  high
tibial  osteotomy,  &  for  valgus  deformity  we  do  supracondylar  femoral
osteotomy.

Genu recurvatum:

Possible causes:

1. Congenital; by abnormal intrauterine posture, usually not severe &

spontaneously recover but sometimes associated with congenital dislocation
of the knee.

2. Ligament laxity; either congenital & generalized or secondary to injury,

infection, over traction or muscle weakness as in polio.

3. Secondary to fixed equinus deformity of the foot in which the patient

hyperextend the knee to put the foot flat in the ground.

4. Following growth plate injury.
5. Malunited fractures.

Treatment:

When indicated corrective osteotomy of the tibia or femur is done. Other
operation is excision of the patella & fix it on the upper tibia to act as a bone
block to prevent hyperextension of the knee.

Summary:

1. Normal knee is at 5-7 degrees of valgus, anything less is genu varus,

anything more is genu valgus and any abnormal hyperextension is genu
recurvatum.

2. Causes can be developmental, congenital or secondary aquired.
3. For genu varus we examin the intercondylar distance, for valgus we

examin the intermalullar distance its good for the diagnosis, follow up
and prognosis of genu varus and valgus.

4. Developmental varus and valgus may improve during the development

and bone remodlling up to the age of 9-10 years, if it didn’t correct this
indicates surgical intervension.

5. Most secondary angular deformities may need treatment of the primary

cause and surgical opration.

6. Surgery may be in the form of epiphysial growth arrest (stappling) or

by osteotomy.

Meniscal diseases ( injuries and meniscal cyst):

Objectives:

1. Discuss the surgical pathology, functions, mechanisms of meniscal injuries

and variable types of meniscal tears.

2. Describe the clinical presentation differential diagnosis and investigations

of meniscal injuries.

3. Discuss the methods of treatment of acute and chronic meniscal tears.
4. Define meniscal cyst and describe its clinical presentation, differential

diagnosis and investigations.

5. Discuss the treatment of meniscal cyst.

Pathology & mechanism of injury:

Medial meniscus is more commonly involved in injury because:

1.  It’s larger in size.
2.  It’s more fixed to the tibia & capsule.
3.  Its more commonly involved in serious joint strains & activities.

Functions of the menisci:

1.  Improve range of motion.
2.  Better distribution of the synovial fluid inside the joint.
3.  Act as a shock absorber.
4.  Improves joint stability.
5.  Sterioseption as they contain special nerve endings.

Menisci are avascular structures except for its peripheral one third near the
capsule where tears may heal but not in the center where the tears never heals
and may cause irritation of the synovium with synovial effusion but not
heamarthrosis.

Mechanism of injury:

Is that the medial meniscus get grinded between the femur & tibia when the

flexed loaded knee get twisted causing meniscal tear which most commonly
seen in young adults & athletes specially footballers.

Types of meniscal tears:

  75% of the tears are vertical tears; most common type is that which involve
the middle part of the meniscus but does not reach the periphery, the possible
displacement  of  the  central  segment  which  is  still  attached  to  the  peripheral
fixed part giving the appearance of bucket handle and called bucket handle tear
which is the most common cause of locking of the knee joint in meniscal tears.
Other vertical tears may reach the center causing anterior or posterior horn tear.
Less  common  tears  are  the  horizontal  tears  that  most  commonly  occurs  in
degenerated stiff meniscus of older people.

Clinical features:

  The  patient  usually  young  adult  footballer  had  history  of  severe  twisting
injury  of  the  knee  followed  by  severe  knee  pain  &  inability  to  complete  the
game.
   Knee  swelling  &  effusion  occurs  after  several  hours  to  24  hours  from  the
time of injury, but never occurs immediately (as in heamarthrosis).
  There is limitation of knee movements, mainly knee extension i.e. locking
of  the  knee,  which  means  failure  of  the  last  degrees  of  extension  (its
mechanical  locking  by  the  effect  of  the  displaced  bucket  handle  tear  of  the
meniscus).
  Few  days  later  effusion  subsides  &  the  knee  may  spontaneously  unlock,
while the pain is still mild and takes longer to disappear. Always there is severe
quadriceps wasting.
  Chronic  frequent  knee  pain  and  effusion  may  occur  later  on  after  milder
twisting  injury  during  work  or  games,  sometimes  frequent  locking  &
givingway.

Investigations:

1. X-ray; to exclude associated fracture.
2. Arthroscopy; it’s the best to give direct visualization of the inside of the joint

to prove the diagnosis & exclude other possible injuries.

3. MRI; good and accurate noninvasive technique specially if associated with

arthroscopic findings.

Differential diagnosis:

1. Lose bodies; they cause pain and locking that occurs at different degrees of

knee movement (change in the position of locking) at each time.

2.  Patellofemoral instability; with frequent knee pain & givingway.
3.  Fracture of tibial spine.
4.  Rupture of anterior cruciate ligament (ACL).
5.  Partial tear of medial collateral ligament with tender medial femoral condyle

at the site of attachment.

All above conditions can be can be diagnosed clinically, arthroscopically & by
MRI.

Treatment:

   Arthroscopy  can  prove  the  diagnosis  &  show  the  site  &  type  of  the  tear.
Conservative  treatment  is  only  indicated  for  peripheral  tears  where  the
vascular meniscus may heal if the knee is rested for 3-4 weeks in POP or if the
meniscus is sutured.
Otherwise operative treatment is always indicated by arthroscopy, the aim is
to excise the torn part of the meniscus only & leave the remaining intact part to
avoid later degenerative changes of the knee.
   Always remember the possible associated injuries as ACL tear, fractures or
synovial damage and heamarthrosis.

Prognosis:

Neither meniscal tears by itself nor removal of the meniscus necessarily
leads to secondary osteoarthritis, but it’s the general state of the knee, its
stability and the possible associated injuries that matter.

Meniscal cyst:

It’s a multiloculated cystic swelling that contains gelatinous fluid &
surrounded by fibrous tissue, it occurs between the meniscus (usually the
lateral) & the capsule; it shows as a localized swelling below the joint line its
more prominent at certain degrees of knee fiexion (65 degrees) & decrease in
size at other positions of the knee.

Causes:

1. Synovial implantation theory in which following trauma or embryonic

synovial cells implants in the vascular area of meniscus & grow as a cyst.

2. Secondary to horizontal tear of the lateral meniscus.

Clinical features:

It usually appears at the lateral side of the knee just below the joint line
anterior to the collateral ligament.
It shows as a painful aching lump that gets larger in certain movements and
may disappear in others.

Differential diagnosis:

1.  Ganglion; its more superficial, softer & above or below the joint line.
2.  Calcified deposit of the collateral ligament.
3.  Prolapsed torn meniscus.
4.  Various tumors as; lipoma, fibrorna or osteochondrorna.

Treatment:

Always do arthroscopy to exclude intraarticular lesions as meniscal tear which
when treated may lead to decompression of the cyst from within.
Otherwise we do surgical excision of the cyst.

Summary:

1. The medial meniscus is more prone to injury than the lateral, the outer

third of meniscus is vascular and the remaining is not, it serves variable
functions including increasing the range of motion and knee stability.

2. Commonest type of tears are the longitudinal (bucket handle or horn

tear), the meniscus usually torn when the loaded knee is flexed and
twisted.

3. Clinically torn meniscus presents as pain and later swelling with

possible locking, chronic complaint is by recurrence of symptoms at a
milder knee twist.

4. Arthroscopy is the best for diagnosis as well as for the treatment by

partial excision of the torn part of the meniscus.

5. Meniscal cyst is uncommon and mostly lateral it presents as local

swelling and may due to a meniscal tear.

6. Meniscal cyst needs arthroscopy to diagnose and treat associated

meniscal pathology. otherwise surgical ecsion of the cyst is done.

Chronic ligamentous instability:

  Untreated  ACL  or  collateral  ligament  tears  may  cause  chronic  joint
instability  with  variable  symptoms,  functional  disturbances  &  possible  later
osteoarthritis.  Those  patients  needs  good  clinical  &  arthroscopic  assessment,
together  with  intensive  course  of  physiotherapy  &  muscle  strengthening
exercises  (including  the  quadriceps  &  hamstring  groups)  all  to  improve  joint
stability & function.
  Whenever there is associated meniscal tear it must be surgically treated to
improve symptoms & allow physiotherapy.
Otherwise if conservative treatment is not useful, surgical reconstruction of the
torn ligament is done by using certain structures as fascia lata or surrounding
tendons or even synthetic grafts to pass in such a way to take the function of
the  torn  ligament,  this  must  always  be  followed  by  good  course  of
physiotherapy.

Patellofemoral Diseases

Objectives:

1. Declare variable patellar functions and the factors that prevents patella

from dislocation as well as main cause of patellar dislocation.

2. Discuss in details the common recurrent patellar dislocation, mechanism,

clinical presentation, emergency treatment and available surgical options
of its treatment.

3. Define patellofemoral overload syndrome, its clinical presentation,

diagnostic tests, investigations and differential diagnosis.

4. Discuss than main lines of its management, non-surgical and operative

choices.

Patellofemoral instability:

Patella have different functions that includes:

1.  Protection of the knee on kneeling.
2.  Improvement of knee function & range of motion.
3.  Prevent direct friction of extensor mechanism with the femur.

Knee is normally in 5-7 degrees of valgus therefore quadriceps pull may cause

lateral subluxation or dislocation of patella, this does not occur because:

1.  There is large & high lateral femoral condyle.
2.  Tight extensor retinaculum that prevents displacement.
3.  Direct  medial  pull  of  patella  by  the  lower  horizontal  fibers  of  the  vastus

medialis, which has direct attachment to the patella.

Patella usually has tendency for lateral dislocation or subluxation & some of

the predisposing factors include:

1.  Congenitally abnormal patella (cong .high or small patella).
2.  Abnormally small lateral femoral condyle.
3.  Valgus knee.
4.  Generalized ligament laxity.
5.  Primary muscle defect.

Types of patellar dislocation:

1. Post-traumatic dislocation (previously discussed).
2. Non-traumatic dislocations;

A. Congenital dislocation.
B. Recurrent dislocation.
C. Habitual dislocation.

Congenital patellar dislocation:

Its rare & severe form associated with abnormal soft tissue attachment &
sometimes with knee dislocation. Treated by different procedures of soft tissue
reconstruction but the results are unpredictable.

Habitual dislocation of the patella:

In this type the patella dislocates every time the knee is flexed & relocates in
extension.
It’s possibly caused by Q-contracture (vastus lateralis) either congenital or
secondary to early childhood injection.

Treatment:

By division of the contracted bands of vastus lateralis, iliotibial band rectus
femoris & V-Y plasty of the Q-tendon.

Recurrent patellar dislocation:

It’s the most common type usually occurs in adolescent girls & mostly

bilateral.
Mechanism and clinical features:

It occurs when sudden Q-contraction is taken to extend the flexed knee, The

patella dislocates laterally with a click & this will cause severe pain, patient is
unable to extend his flexed knee & fall down. Sometimes the knee relocates on
certain movements as the patient try to straighten his flexed knee.

When dislocated there is prominent medial femoral condyle that sometimes

mistaken for the patella.

Tenderness on the medial side of the joint and heamarthrosis will occur. In

chronic cases there is medial retinacular laxity & apprehension test is positive, i.e.
on examination an attempt to dislocate the patella laterally during knee flexion will
cause pain and the patient will resist the completion of the test (he is afraid from
dislocation).
X-ray:

It may show abnormal patella or lower femur; MRI & CT scan may help
diagnosis.

Treatment:

  At  the  time  of  dislocation  reduction  by  MUA  with  aspiration  of
heamarthrosis  &  back-slap  for  3  weeks.  Followed  by  intensive  course  of
physiotherapy & Q-exercises especially vastus medialis.
If  this  fails  or  dislocation  is  frequently  recurrent,  operative  treatment  is
indicated; some of these operations are:

1. Lateral release +/- medial reaf of the ext. retinaculum to decrease the lateral

pull of the patella.

2. Camblell-roux operation; using a medial slip of retiaculum to be turned

around the Q-tendon & refixed medially to induce medial displacement of
the tendon & patella, all associated with lateral release & medial reaf.

3. Goldthwait operation; we release a lateral slip of the patellar ligament from

its attachment on the tibia and pass it medially below the remaining part to
be fixed to the tibia again so that it can improve medial pull of the patella.

4. Hauser operation, where the whole attachment of the patellar ligament is

displaced distally & medially.

5. All operations followed by good schedule of physiotherapy & Q-exercises.

Patellofemoral overload syndrome; Patellar pain syndrome or
Chondromalacia patellae:

All are names for the same clinical syndrome of anterior knee pain &

Patellofemoral tenderness, usually associated with softening & fibrillation of the
patellar articular cartilage (Chondromalacia patellae). It’s more common in
adolescents & young adults.
Pathology & pathogenesis

The problem is mainly a form of overstressed Patellofemoral joint with

repeated injury of patellar articular cartilage; this mostly because of malcongrousy
or malaligenment of Patellofemoral joint leading to a sequence of changes in
cartilage & bone.
It starts as cartilage edema, softening, fibrillation & subchondral venous
congestion that may be the cause of pain. Later subchondral bone sclerosis or cyst
formation. Still it’s found that Chondromalacia is not a precursor of osteoarthritis.

Clinical features:

Patients are usually teenager girls or young adult athletes, they complain of

anterior knee pain, sometimes there is history of patellofemoral instability. Pain
aggravated by activity, climbing upstairs, or when standing after prolonged rest
(theater sign).

Sometimes occasional swelling & givingway may occur & symptoms can show

bilaterally.

On examination the knee looks normal, there is Q-wasting & tenderness on the

under surface of the patella.

Mild effusion may occur & on knee movement abnormal patellar tracking &
subluxation or even crepitus can be noticed.
Apprehension test sometimes positive.

Specific test is the grinding test, it’s the reproduction of the pain by asking the

patient to contract the Quadriceps while the examiner is compressing the patella
against the femur, and this will induce painful friction of PF-joint in those patients.
Imaging:

X-ray of the knee may show abnormal patella or femur. Special view is the

skyline view taken with the knee flexed to show the relationship between patella &
femoral condyles & can prove possible subluxation or instability.

CT scan with extended knee is best & most accurate.

Arthroscopy: it can show cartilage changes but it’s most important to exclude
other causes of knee pain.
Differential diagnosis:

For other causes of anterior knee pain as;

1.  Overuse in athletes.
2.  PF-instability.
3.  Patellar cyst or tumor.
4.  Prepatellar bursitis.
5.  Osteochondritis dissecans.
6.  Torn meniscus.

Treatment:
1st. Conservative treatment:

This includes avoidance of stressful activities, reassurance & physiotherapy

to alleviate symptoms, most important is long course of Q-strengthening exercises
especially vastus medials.

Drug treatment includes NSAID & painkillers, neither aspirin nor

indomethacine have specific effect.

2nd. Surgical treatment:

It’s indicated if conservative treatment fails after 6 months use, it aims at

control of malcongrousy & malaligenment of the PF-Joint &decrease PF-pressure.

Lateral retinacular release +/- medial reaf is one famous operation to

improve patellar tracking, this usually done alone or together with other procedures
as:

• Hauser operation.
• Distal elevation of the patella by using a bone block to elevate the tibial

tubrosity.

• Chondroplasty by shaving the cartilage.
• Patellectomy for severe resistant cases that does not respond to other

possible procedures.

Summary:

1. Patella is important for proper extensor knee mechanism , it increases knee

range of motion and specially important on taking the stairs and running.

2. The large lateral femoral condyle and the tight extensor retinaculum

around it and the direct attachement of the transverse lower fibers of vastus
medialis – all – keeps patell in position.

3. Patella dislocates if its small or high or if there is small lateral condyle or

any abnormality of the bone or soft tissue that makes the the patella pushed
laterally like valgus or external rotation of the leg.

4. recurant pat. Dislocation is the most common type usually occurs in

adolescent girls & mostly bilateral, It occurs when sudden Q-contraction is
taken to extend the flexed knee

5. Pain tenderness on the medial side of the joint and heamarthrosis occurs in

acute dislocation. In chronic cases there is medial retinacular laxity &
apprehension test is positive.

6. urgent reduction is easy and treatment of recurance directed towards

treatment of the cause if there is one, and all are aiming at medialization of
the pull of the extensor mechanism.

7. patellofemoral overload syndrome is a clinical syndrome of anterior knee

pain & Patellofemoral tenderness, usually associated with softening of the
patellar articular cartilage, It’s more common in adolescents & young
adults and due to friction or over stress through the PFJ.

8. presentation is anterior knee pain, sometimes history of instability. Pain

aggravated by activity, climbing upstairs, or when standing after prolonged
rest (theater sign). swelling & givingway may occur & symptoms can be
bilateral.

9. On examination Q-wasting, tenderness on the under surface of the patella,

abnormal patellar tracking or crepitus can be noticed. Apprehension test
and Grinding test sometimes positive.

10. treatment usually nonoperative and surgery reserved for resistant case and

are mostly like those for instability.

Osteochondritis dissecans (splitting O.ch. of the knee):

The definition is previously discussed, its suggested to be caused by repeated

trauma by the edge of the patella on full flexion that occurs on the lateral aspect
of the medial femoral condyle (this site accounts for more than 80% of all cases).
The disease pass in three stages:

1.  Avascular nonseperated segment with intact overlying cartilage.
2.  Detached Undisplaced segment.
3.  Displaced segment, either incomplete or complete where it acts like a loose

body leaving an ulcer called crater that later get fibrosed.

Clinical features:

Adolescent patient mainly males 15-20 years of age, it can be bilateral & may

run in families.

There is intermittent pain, swelling, givingway & locking together with muscle

wasting.
Diagnostic features are:

1. Tenderness on medial femoral condyle.
2. Positive Wilson’s test; with the knee flexed we try internal rotation &

gradual extension; this will induce medial condyle pain which get relieved
on external rotation.

X-ray:

It’s helpful at later stages. While isotope scanning and MRI can diagnose it
earlier.

Arthroscopy: can prove diagnosis & sometimes used for treatment.
Differential diagnosis:

1. Avascular necrosis of the medial fernoral condyle that occurs in older

alcoholics or in steroid abuse, it affect the dome of the condyle & is
more extensive.

2. Osteochondral fracture of the femoral codyle.

Treatment:
  In early stages the lesion is stable, here restriction of activities with the use of
caliper  or  crutch  for  6-12  months  is  useful  and  no  need  for  other  treatment,
intimate follow up & MRI of the other knee is indicated.
  At later stages & if the fragment is small it can be removed.
  If its more than one centimeter & not detached we fix the fragment in position.
  If the fragment is detached with unhealthy crater, it’s removed & the crater is
drilled to allow healing with fibrocartilage.

Synovial chondromatosis:

  Rare disorder in which the tips of the synovial sheath undergoes cartilaginous
metaplasia  &  later  detaches  as  a  free  cartilaginous  loose  bodies  (handreds  or
thousands  of  them  giving  the  appearance  of  a  snowstorm)  sometimes  those
cartilage pieces gets ossified & the condition is named synovial chondrocalcinosis.
  Different theories where proposed, one stated that chondrocytes get implanted
& grow on the surface of the synovium & later detached as chondroid loose bodies
that may ossify.
Clinical features:

Chronic swelling, givingway, locking & pain are common.

X-ray:

it may show loose bodies.

Arthroscopy:

can prove the diagnosis (snowstorm appearance).

Treatment:

By athrotomy or arthroscopy, all those loose bodies must be washed out and

removed & the abnormal synovium is excised (synovectomy).

Loose bodies inside the knee:

Causes:

1.  Post-traumatic osteochondral fracture.
2.  Fractured ostephytes in cases of osteoarthritis of the knee joint.
3.  Osteochondritis dissecans.
4.  Synovial chondromatosis.
5.  Charcot’s (neuropathic) joint.

Clinically they cause aches, swelling, locking & givingway.
Diagnosis by X-ray, MRI, and arthroscopy.
Treatment by removal of the loose bodies & treatment of the cause.

Swelling of the knee joint:

Causes are:

1st. heamarthrosis: by;

1. Hemophilic arthropathy.
2. Post-traumatic by; a. Intraarticular fracture

b. Rupture of ACL or capsule.

c. Rupture or damage of the synovial membrane.

Clinical features, diagnosis & treatment all according to the cause.

2nd. Acute septic arthritis:

Causes, pathology, C/F, investigations, differential diagnosis & treatment all
are previously discussed.

Special  point  is  that  sometimes-repeated  aspiration  by  wide  bore  needle  or
cannula  &  trocher  is  used  in  the  knee  together  with  saline  irrigation,  all
under  antibiotic  cover.  If  this  fails  we  still  can  do  open  arthrotomy  and
drainage.

3rd. Acute post-traumatic synovitis:

Synovial fluid collects few hours after injury or in the next day, this is
associated with Q-wasting & painful limitation of movements. Sometimes it
needs aspiration & resting the joint in POP.

4th. Acute non-traumatic synovitis:

Acute swelling without trauma or infection suggests crystal deposition
disease as Gout or Pseudogout; this may need aspiration & biochemical
study.

5th. Chronic knee swelling: as with;

a. Tuberculosis.
b. Rheumatoid arthritis.

c.  Osteoarthritis.
d.  Pigmented villonodular synovitis.
e.  Charcot’s disease (neuropathic joint).

Osteoarthritis of the knee (OA):

Knee is commonly involved by OA, which can be secondary or most

commonly primary OA that usually affect people after 5Oyears and mostly occurs
bilaterally.
Pathology; previously discussed.
Clinical features: Special features include;

•  Bow legs (Genu varus) its very common.
•  Pain on varus or valgus stress of the knee in the affected joint compartment
•  On knee movement PF-crepitus may be reproduced.

X-ray:

All previously mentioned cardinal features are seen with special features like;

•  Features mostly seen in the medial compartment.
•  There is varus alignment between tibia & femur.
•  Picture better seen in the standing films.

Treatment:

Conservative treatment?
Operative treatment may include:

1. Arthroscopic washout; to decompress the joint &wash the proteolytic

enzymes & loose bodies.

2. Patellectomy.

3. Realignment osteotomy; to correct varus deformity we do wedge resection

valgus osteotomy of the upper tibia, this acts by
•  Redistribution  of  weight  towards  more  healthy  areas  of  the  articular
cartilage.
•  Venous decompression to decrease pain.
•  Correct deformity.

4. Replacement arthroplasty.
5. Arthrodesis.

Swellings around the knee joint:

Causes are;

1. Prepatellar bursitis;

  There is inflammation of the bursa between the skin & the patella, the condition
called  house-made  knee.  The  joint  is  normal  but  there  is  swelling  of  the  bursa
sometimes  its  tender,  it  may  need  aspiration  &  steroid  injection  or  sometimes
surgical excision. Always exclude rheumatoid & gouty arthritis.

2. Infrapatellar bursitis;

It’s inflammation of the bursa between the skin & the patellar ligament, its

also called clergyman’s knee.

3. Semimembranosus bursa;

Swelling of the bursa between the semi-membranosus tendon & the medial

head of gastrocnemious muscle appears as a painless swelling on the posteromedial
aspect of the knee, its fluctuant & gets larger when the knee is straight and
decrease or disappear as the knee is flexed. If it’s symptomatic it needs surgical
excision.

4. Popletial cyst (backer’s cyst):
It’s a type of synovial fluid filled cystic swelling herniates posteriorly from the

knee  joint,  its  most  common  in  OA  of  the  knee  and  also  in  some  cases  of
rheumatoid  arthritis.  Its  painless  fluctuant  &  at  the  level  of  the  joint  it  does  not
affected by the knee movements. Treatment, always treat the cause specially OA as
by high tibial osteotomy, which usually lead to cyst regression. Sometimes we do
aspiration  &  local  steroid  injection  or  surgical  excision  of  the  cyst  but  those
procedures usually associated with recurrence of the cystic swelling.

5.  Popletial artery aneurysm.
6.  Meniscal cyst.
7.  Ganglion.
8.  Calcified deposits of collateral ligament.
9.  Prolapsed torn meniscus.
10. Tumors like; lipoma, fibroma or osteochondroma.

Important questions to be remembered;

Causes of anterior knee pain?
Causes & management of swelling of the knee joint?
Causes & management of swelling around the knee joint?
Causes of loose bodies inside the knee joint?
Pathology and management of meniscal tear in young adults or athletes?
Factors of patellofemoral stability?
Predisposing factors for PF-dislocation?