Injuries of the knee &leg

injuries of the knee &leg
acute knee ligament injuries: common in sports &rta.
knee stability depends on joint capsule, intra- & extra-
articular lig. &controlling muscles rather than on bony structures.
moi: valgus force? mcl tear valgus +rotation? mcl+acl tear
valgus +rotation +weight bearing? mcl +acl + med. meniscus tear
varus force? lcl tear varus + rotation? lcl + acl tear
dashboard injury? pcl tear.
cf: twisting injury? immediate painful doughy swelling(hemarthrosis)
while in meniscus injury, swelling is late &fluctuant(synovial effusion).
look for site of maximum tenderness, bruises &abrasion.
test for ligament tear:
partial tear is painful with no abnormal movement,
if in doubt? stress view.
complete tear: painless abnormal mvt? if knee open with
valgus or varus stress in 30°flexion? only collateral tear
if open in extension? capsule + collateral + cruciate tear
anteroposterior stability: posterior sag? pcl tear
anterior drawer test? acl lachman test? acl.
imaging:
x-ray: may show avulsion # e.g. acl avulse tibial spine.
mri: to differentiate partial from complete tear.
arthroscopy: is contraindicated in acute complete tear.
treatment:
partial tear: aspirate hemarthrosis? 6wks brace or
crepe bandage with early active exercise.
complete tear: mcl or lcl tear: 6wks brace? exercise.
acl or pcl tear: 6wks brace? exercise later
if instability persists? ligament reconstruction.
combined collateral + acl or pcl: 6wks
brace? exercise? later reconstruction.
complications: 1-adhesion: occurs with partial tear
bec. torn fibers stick to nearby tissues cf: attacks of pain & giving
way mri differentiate it from meniscus tear ?: physiotherapy.
2-instability: the knee continue to give way? oa.
chronic ligamentous instability ( giving way ): either
appear early after acute injury or progressively later. it is often
tolerated in patient with usual activity rather than sport activity.
cf: feeling of knee insecurity &giving way.
o/e: quadriceps wasting no tenderness see the patient walking,
standing on one leg, test the knee for hyperextension.
tests for abnormal movement:
for side-to-side stability? varus/ valgus stress tests.
for anteroposterior stability? anterior &posterior
drawer & lachman test .
for rotatory stability? modified drawer &pivot shift test.
imaging: mri is reliable for cruciate &meniscus injury.
arthroscopy: is both for diagnosis &surgical ?.
?: 6 mths of quadriceps &hamstring exercise? re- examine
? most of patients will not need operation except sportsmen,
intolerable giving way &recurrent locking of meniscal tear.
operative ?: arthroscopic reconstruction
isolated acl tear? replacement with strip of patellar
tendon graft with bone at either end.
anteromedial &anterolateral rotatory instability:
acl+mcl or lcl? acl reconstruction is enough.
posteromedial &posterolateral rotatory instability:
pcl+mcl or lcl? repair of all damaged structures.
fractured tibial spine:
is the adolescent variant of acl tear.
moi: acl traction by severe twisting or varus/valgus force.
cf: swollen tender knee with doughy feel.
x-ray: the # may be missed the spine(intercondylar eminence)
may be: ?-undisplaced ?-hinged ?-completely displaced.
?: uga the joint is aspirated &manipulated to full extension?
6wks plaster cylinder. if there is block to full extension or the fragment
is significantly displaced? orif.
dislocation of the knee:
moi: a force tearing capsule, cruciate &coll. lig.? knee ?.
cf: severe swelling, bruising + gross deformity. 20%
will have popliteal art. &/ or peroneal n. injury.
35% of ? reduce spontaneously after injury(occult ?).
x-ray: ? can be in any direction(ant., post., lat., med.)
any lig. can avulse a piece of its bony attachment.
?: urgent cr uga? back-splint with frequent check
of the circulation in the 1st week, later ? hinged brace.
if cr fails, vascular injury or open ? ? open reduction
+ lig. repair. complication: knee instability or stiffness.
fractured patella:
anatomy: the patella is a sesamoid bone in the quadriceps tendon
vastus medialis &lateralis also inserted into medial &lateral sides
of the patella the medial &lateral extensor retinacula are expansion
of quadriceps bypassing the patella & inserting into the upper tibia.
the main function of the patella is to ? the efficiency of the quadriceps.
moi: either
direct injury like dashboard blow or fall onto the knee? undisplaced
crack or comminuted(stellate) # with no tear of the extensor expansion.
indirect injury by traction of quadriceps contraction against resistance
? transverse # with gap bec. of extensor expansion tear.
cf: swollen bruised knee if direct injury the patient can lift his leg
&no gap can be felt in contrast to indirect injury. aspiration? blood
+ fat dropinglets.
x-ray: bi- or tri-partite patella(with smooth
rounded edge) should not be mistaken for #.
?:
undisplaced #: aspirate hemarthrosis? 4wks cast + exercise.
comminuted #: if undisplaced ? the same ?. if displaced
? immediate patellectomy(to avoid later patellofemoral oa).
transverse # with gap: orif +repair of extensor expansion.
2k-wires + tension band, screw, cerclage wire &patella plate.
complication: patellofemoral oa.
dislocation of patella: is almost
always lateral with tear of med. patellofemoral lig. &med. retinaculum.
moi: direct force is rare often indirect twisting injury? quadriceps
contraction while the knee in valgus &external rotation.
risk factors: genu valgum, tibial torsion, patella alta, shallow
intercondylar groove, lig. laxity &weak vastus medialis obliqus(vmo).
cf: the patient fall to the ground the patella is felt on lateral side of
the knee knee movement is impossible. often it reduces spontaneously
leaving tenderness &bruises on medial side.
x-ray: the patella is displaced laterally &there may be osteochondral #.
?: push patella back into its place? 3wks brace? 3mths q exercise.
some prefer operative repair of medial patello femoral lig.(mpfl)
to prevent recurrent ? in severe injury.
complication: recurrent ? (20%).
tibial plateau fractures: adults(50-60).
moi: varus or valgus force + axial loading like
car striking a pedestrian (bumper #) or ffh.
schatzker s classification:
type 1 - lateral condyle split #. 2 - lateral condyle split-depressed #. 3 - lateral condyle depressed #. 4 - medial condyle split or depression #. 5 – bicondylar #. 6 – uni or bicondylar + subcondylar #.
cf: swollen, deformed &bruised knee with doughy
feel look for vascular injury, compartment
syndrome, ligament tear &nerve injury.
x-ray: ap& lateral views ct & mri.
?:
conservative: aspirate the hemarthrosis & apply
crepe bandage? 2wks continuous passive motion
(cpm) machine? 6wks hinged brace nwb? 6wks pwb.
operative: orif? screws alone or plate (locked or buttress) +
elevation of any articular depression &support with bone graft.
in severe soft tissue injury, open # or severe # comminution,
external fixator(± minimal internal fixation) gives better result.
?&?v: if undisplaced? conservative
if displaced? orif.
?&?: if depression >5mm &young? orif.
if <5mm or elderly? conservative.
v &v?: if severely displaced, there is a risk of comp. syndrome.
if undisplaced or slightly displaced in elderly? conservative.
if displaced? orif or circular-frame external fixation or
6wks skeletal traction? 6wks brace.
complications: early: compartment syndrome: may be seen in
closed type 5&6 due to excessive bleeding.
late: knee stiffness, varus or valgus deformity &oa(after 5-10yrs).
fractures of proximal end of fibula:
moi: either direct blow or indirect twisting injury.
the isolated # is rare &needs no ? but look for associated injuries:
1-ankle # or ligament tear(maisonneuve #) always x-ray the ankle.
2-knee lig. injury always check knee stability.
3-peroneal nerve injury. late complication: peroneal nerve entrapment.
fractures of tibia &fibula: fracture tibia
is common &often it is open because of its
subcutaneous position.
moi: indirect injury(low energy e.g. sport)? spiral or oblique #
bone fragment may pierce the covering skin from within.
direct injury(high energy e.g. rta)? comminuted # +
overlying skin crush or split.
pathological anatomy: # healing depends on:
1- severity of soft tissue injury: tscherne s classification of skin
lesion in closed #:1-no lesion 2-contusion 3-localized degloving
4-extensive degloving 5-necrosis from contusion.
for open # ? gustilo s classification.
2- severity of bone injury: high energy injury? comminuted &open(g ? a,b,c).
low energy injury? spiral &closed or open(g? or ?).
3- stability of the #. 4- degree of contamination.
cf: swollen deformed leg &externally rotated foot.
look for: open wound skin bruising, crushing & tenting
weak or absent pulse, compartment syndrome & nerve injury.
x-ray: the entire leg with knee &ankle should be seen.
management: aim: 1-limit st damage &preserve skin cover
2-prevent compartment syndrome
3-reduce &hold the #
4-start early weight bearing
5-early joint movement.
conservative ?: for stable low energy # if undisplaced or slightly
displaced with little soft tissue damage? full length cast(from mid
thigh to metatarsal necks) &elevation for 2wks? checking x-ray &
cast renewed if become loose? 16wks pwb. if skin viability is
doubtful? 2wks observation in back slab &elevation? casting.
operative ?: for displaced high energy unstable # with more st damage:
closed intramedullary nailing(for closed shaft # &open g ?, ?, &?a)
plate fixation(open plating for metaphyseal # or mipo for shaft &metaphyseal #) &
external fixation for open # g ?b&c &closed #
with severe comminution &/or severe st damage.
complications: early:
1-vas. injury: prox. 1/3 # may injure pop. art.? repair.
2-comp. syndrome(prox. #): fasciotomy? ext. fixation.
3-infection: 1% for g ? &30% for g ?c.
late: 1-malunion: 1.5cm shortening &7?angulation are
acceptable, if more or mal-rotation? tibial osteotomy.
2-delayed union &nonunion: especially in high energy #,
infection or bone loss? stable fixation &bone graft.
3-joint stiffness: of ankle may lasts 12months.