10/28 - Meniscal Injury Surgery Rehab Flashcards
why were there poor outcomes w complete meniscectomies
osteophyte formation
joint space narrowing
OA changes
what is the shape of the meniscus and how is this integral to its function
wedge shaped
deepens joint
helps the articulation of the femur and tibia
what characteristic gives the meniscus its strength and ability to resist load and tension in various directions
orientation of all fibers
- oriented differently depending on the layer
what is the compensation of the extracellular matrix
mostly water (72%)
collagen (22%)
- type 1 - 90% dry weight
describe the blood supply to the menisci
periphery from capsular lining
lat and med geniculate a.
peripheral vascularity
how does vascularity change throughout the meniscus and why is this significant
peripheral most vascularized
- best at A-P horns
limited on medial side
affects healing potential if there is less blood supply
why do the A-P horns have the best vascularity
where the menisci attach to the bone
- why you get better blood supply
describe innervation of the menisci
free nerve endings greatest density in outer 1/3 & A/P horns
mechano receptors
how does the innervation contribute to the menisci functions
meniscus plays a role in proprioception, mechanoreception, joint position sense, and balance
what are the 3 mechanoreceptors found in the menisci and how do they specifically contribute to meniscus function
type 1 - Ruffini
type 2 - pacinian
type 3 - golgi
type 2 = joint motion
type 1 and 3 = joint position
what type of mechanoreceptor(s) detects joint position
type 1 and 3
what type of mechanoreceptor(s) detect joint motion
type 2
what are type 1 mechanoreceptors and what does it detect specifically
ruffini
pressure
what are type 2 mechanoreceptors and what does it detect specifically
pacinian
tension
what are type 3 mechanoreceptors and what does it detect specifically
golgi
terminal ROM
what is often a precaution after a medial meniscus repair and why
limit hamstring activity
- semimem attaches to med meniscus
med vs lat meniscus: shape, area, attachments, mobility
SHAPE:
- med = “c” or crescent shape
- lat = “o” or circular shape
AREA:
- med = cover 60% of articular cartilage
- lat = cover 80% of articular cartilage
ATTACHMENTS:
- med = semimem, deep MCL
- lat = popliteus
MOBILITY:
- med = firmly fixed
- lat = very mobile
meniscal excursion: med vs lat
med: 5mm
lat: 11mm
what creates meniscal excursion in NWB vs WB
NWB - ms move menisci
WB - condyles move menisci
what are the menisci functions (7)
joint stability
shock absorption
joint lub and nutrition
proprioception
load bearing
maintain joint height
maintain hoop stresses
how does the menisci function to create joint stability
makes femorotibial articulation more congruent
- facilitates articulation
how is shock absorption impacted after a meniscectomy
dec by 20%
describe the load bearing function of the meniscus
load during activity
- 70% lat compartment load
- 50& med compartment load
how is load bearing affected by a meniscectomy
contact area reduced by at least 1/2
contact pressure inc 2-3x
how does the menisci function to maintain hoop stresses
convert compressive force to tensile force
- multidirectional fibers allow response to force in all directions
what are 4 risk factors for a meniscal tear
older age (>60yo)
male
work related kneeling/squatting
climbing >30 flights stairs/day
what population is it common to see acute meniscal tears in
cutting sports
- soccer
- rugby
what is the nature of the majority of meniscal tears
degenerative (aka older age)
what is a risk factor for future medial meniscal tears and why
delayed ACLR
ACL damage allows more mobility in knee and creates more shear and torsion at meniscus
incidence of meniscal path in med vs lat menisci
40 in med
60 in lat
significance of ant vs post horn meniscal path
ant - more sx closer to full ext
post - more contact as deeper into flex
significance of meniscal path in the body of the meniscus
limitations in blood supply
- poor potential for healing
incidence of central vs peripheral meniscal path
central - dec
peripheral - inc
what does a delay in ACLR inc the risk of
cartilage and med meniscus lesions
what is a frequent concomitant injury w meniscal path
ACL
what is the prevalence of meniscal path
2nd most common knee injury
why does the risk of meniscal path inc substantially w age
degenerative changes
long term sustained load that led to degenerative changes
what are 3 zones used to describe the vascular region that meniscal path could be in
- red on red
- red on white
- less blood supply - white on white
- almost no blood supply
- purely central portion
what types of tears are the most common
horizontal and longitudinal
what is a complex tear
multiple directions
what is a free-edge fraying tear
more degenerative changes
what is a bucket handle tear and what are indicators of this
sizable tear that flops over
- can act as a chockblock and be obstructive
sx: clicking, locking, catching
- sometimes knee can get stuck in position
what does an obstructive bucket handle tear an indication for
surgery
- can develop flexion contractures
what are the types of meniscal tear (5)
horizontal
longitudinal
complex
free-edge fraying
bucket handle
what are 4 criteria of tears to be handled non-operatively
- stable tear w <3mm displacement
- small tear <1cm, longitudinal
- partial thickness tear
- degenerative tear
imaging and meniscal tears
MRI might not tell you details of tear
- or might not even get one
usually send to PT anyway, even if don’t do well (and they usually do) then better surgical outcomes
ant partial meniscectomy (APM) vs PT outcomes w non-obstructive meniscal tears
no difference
what are the 4 main types of surgical treatments
total meniscectomy
partial meniscectomy
open meniscal repair
arthroscopic meniscal repair
what is a consideration when deciding if a meniscal repair is appropriate and what may be a better option
what is the ability to heal
- what is the blood supply
- if no blood supply, repair will fail
best option in that case would be partial meniscectomy
what is the main reason that total meniscectomies are done today
presence of severe trauma
what does a total meniscectomy result in that makes this an avoided surgical option
degenerative changes in knee
osteophyte formation
what are the concerns with doing a partial meniscectomy
inc articular load (65%)
dec ability to distribute forces
- dec contact area by 10%
outcomes from a partial meniscectomy?
outcomes decline over time
- progressive radiologic degenerative changes (rate of which depends on patient)
rehab plan for partial meniscectomy (5)
control pain and swelling
strength - maximize quads
immediate ROM
unrestricted amb
FWB
what is the main limitation to rehab after a partial meniscectomy
discomfort
swelling in quads
return to activity timeline after partial meniscectomy
work - 1-2wks
full activity - 2-4wks
sports - 4-6wks
what 3 factors contribute to a repair healing better than others
lateral > medial
earlier/more acute > later
younger patients
what concomitant procedure improves healing from a meniscal repair
ACL reconstruction
what is the nature an ACL reconstruction which improves healing of meniscal repairs
drilling tunnels into bone
creating bleeding and healing environment for both aCL and meniscus repair
what are 3 surgical methods for a meniscal repair
outside in
inside out
all inside
what is an outside in technique and what is a pro and a con to this
needle pierces capsule from outside incision then pierces meniscus
pro: less neurovascular injury
con: less precise meniscal suture placement
what is an inside out technique and what is a pro and a con to this
needle pierces thru meniscus first, then out capsule
pro: better meniscal suture placement
con: inc risk of neurovascular injury (tho transient in nature)
what is an all inside technique and what is a pro and a con to this
done completely in the joint (similar to RC repair)
pro: faster, no extra incision
con: weaker fixation than suture
outcomes and surgical repair
no significant difference
all work so doesn’t matter much
what does Dr. Nolan attribute failure rates of meniscal repairs to (2)
- d/t new injury during return to sport
- in attempt to preserve as much meniscus as possible, repairing some areas that don’t have good blood supply -> leads to poor healing
why is the healing from meniscal repairs inc w concomitant injury (2)
synovial response
enhanced vascular response
- bleeding from bone
healing timeline after a meniscal repair
50% in 3-4wks
80% in 8-12wks
100% in 14-18wks
what ab the pathology of the injury impacts the treatment guidelines (7)
location of tear
size of tear
type of tear
concomitant injury
pt age (healing)
pt activity level (goals)
integrity of joint
what are 6 rehab considerations when prescribing interventions
WB progression
knee flex AROM
deep squats
rotation activities
pivoting activities
impact loading
meniscal repair rehab goals per phase
weeks 0-4
- protected WBing vs NWB
- avoid re-tear (no squats, hammies)
- ROM 0-90deg
- no resistive work
weeks 4-16
- full ROM by wk 6
- improve strength/endurance
- normalize gait
weeks 17-24
- improve total limb function
- return to sport
ROM with rehab after a repair
immediate 0-90deg
- concern w exercise: avoid rotation at end ranges, utilize midrange (25-85deg)
full ROM by 4-6wks
active mobility with rehab after a repair
no resisted hamstrings for 8wks
active knee flex
- wk 5-6 in peripheral tears
- min 6wks in complex tears
WB in peripheral vs complex tears
peripheral - less restricted d/t good vascularity
complex - larger and more restricted WB progression
why is there limited hamstring activity early post op meniscal repair & when can we transition past this
semimem attachment to med meniscus
popliteus to lat meniscus
AROM 4-6wks
resisted knee flex 6-8wks
what ms are targetted in strengthening after a meniscus repair
quad strength is critical
glut med/hip ER key
what are the 3 main goals of early post-op phase of repairs
- protect repair!
- restore ext ROM / patellar mobility
- minimize ms atrophy / restore quad control
what are 6 main goals of intermediate post-op phase of repairs
- normalize gait
- progress to full pain-free ROM
- gradually introduce load
- develop ms control /endurance
- focus on form!
- high rep, low load - initiate hamstring strengthening
- enhance balance/proprioception
what are 4 main goals of late post-op phase of repairs
- ms hypertrophy
- high load, low reps - progress balance/proprioception
- introduce plyometrics
- interval jogging progression
3 and 4 are more milestone based
partial meniscectomy vs repair
no difference in functional tasks
less OA changes and inc return to prior sports level of activity
what would be a good candidate for a meniscal transplant
young healthy
lower level activity demand
what is an alternative to a meniscal transplant
joint replacement
outcomes from meniscal transplant
good outcomes w pain
long term prevention of cartilage damage is unknown
what are 3 complications of meniscal transplants
failure
infection
inc extrusion of graft
what does rehab look like after a meniscal transplant (6)
immediate motion 0-90
immediate quad work
control swelling
gradual inc motion
WBAT at 6-8wks
running @6mo
