Sports Flashcards
Associated ACL injury?
Lateral meniscus tear 50%
Reasons why women > men for ACL tear?
- neuromuscular forces and control (more quadriceps dominant)
- landing biomechanics (conditioning and strength) play biggest role, females land in more extension, higher vaglus moment
- smaller notches
- smaller ligaments
- hormone levels
- valgus leg alignment
ACL function?
- 85% of the stability to prevent anterior translation of the tibia relative to the femur
- acts as secondary restraint to tibial rotation and varus/valgus rotation
ACL anatomy?
- 33mm x 11mm in size
- anteromedial bundle
more isometric
tight in flexion - posterolateral bundle
tight in extension (contributes greatest to rotational stability)
ACL blood supply?
middle geniculate artery
ACL nerve supply?
posterior articular nerve (branch of tibial nerve)
ACL composition?
- 90% Type I collagen
- 10% Type III collagen
ACL strength?
2200 N
ACL tear grading?
- A= firm endpoint
- B= no endpoint
- Grade 1: < 5 mm translation
- Grade 2 A/B: 5-10mm translation
- Grade 3 A/B: > 10mm translation
Pivot Shift test?
ACL integrity
- Extension to flexion with internal rotation and valgus
- Reduces at 20-30 degrees of flexion
KT-1000?
For ACL anterior laxity
- knee in slight flexion
- ext rotation 10-30 deg
Segond fracture?
Pathognomonic for ACL tear
MRI bruising for ACL tear?
- Middle 1/3 lateral femoral condyle
- Posterior 1/3 lateral tibial plateau
Non-op tx of ACL tear?
- low demand patients with decresed laxity
Who gets operative tx for ACL tear?
- young active pts
- older active pts
- children
- previous ACL reconstruction pts
What if ACL tear with MCL injury?
- allow MCL to heal first (varus/valgus instability can put reconstruction at risk)
What if meniscal tear with ACL tear?
- repair meniscus at time of ACL recon
- shows increased healing rates if repaired at same time
What if PLC tear with ACL tear?
- repair at same time
- or repair PLC as first of two stages
Femoral tunnel placement in ACL recon?
- 1-2 mm of bone posterior to tunnel
- too anterior = tight in flexion, loose in extension
- too posterior loose in flexion, tight in extension
Tibial tunnel placement in ACL recon?
- 10-11 mm in front of anterior edge of PCL
- <75 deg from horizontal
- too anterior = tight in flexion and extension impingement
- too posterior = ACL impinge on PCL
ACL graft preconditioning?
- reduces stress relaxation up to 50%
ACL graft tensioning?
- no difference in level I study
Limb malalignment in ACL repair?
- high tibial osteotomy to address coronal and saggital plane defects prior to recon
B-P-B ACL graft?
- gold standard
- 2600 N load to failure
- higher incidence of knee pain (10-30%)
- cons = patella fx and patella tendon rupture
Hamstring autograft for ACL tear?
- quadrupal strand
- 4000 N load to failure
- decreased fixation strength
- decreased flexion strength at 3yrs compared to BPB
- harvest can damage inferior saphenous nerve
Allograft for ACL tears?
- longer incorporation time
- HIV risk < 1/1 million
- radiation 3 Mrads to kill HIV
- freezing kills cell, doesn’t harm graft
Revision ACL reconstruction?
- don’t reharvest BPB
- use dual fixation
- conservative rehab
Rehab in ACL tear?
- immediate ice and weight bearing
- early full passive extension
- isometric hamstring/quad exercises
- active knee flexion 35-90 deg
- closed chain exercises
- avoid isokinetic quad strengthening and open chain
ACL injury prevention in females?
- neuromuscular training/plyometrics
- when landing, less valgus and more flexion
- increase hamstring strength over quads
ACL bracing?
Only proven effective in skiers
Most common cause of ACL recon failure?
- poor tunnel placement
ACL femoral tunnel too vertical?
- poor rotational stability and + pivot shift
ACL graft screw divergence > 30 deg?
- can cause inadequate fixation/failure
Cyclops lesion in ACL recon?
- fibroproliferative tissue blocks extension
- “click” heard at terminal extension
ACL recon infxn?
- pain/swelling/erythema/elevated WBC 2-24 days postop
- immediate I&D
- serial I&Ds and 6 wks abx to try to retain graft
Facts about exertional compartment syndrome?
- anterior compartment 70%
- ant/lat compartments 10%
- males>females
- 3rd decade
Presentation of exertional compartment syndrome?
- aching/burning pain with exercise
- begins w/i 10 min, resolves 30-40 min
- numbness over dorsum of foot
- relieved by rest
Radiographic studies in exertional compartment syndrome?
Can only r/o other pathologies.
Diagnosing exertional compartment syndrome?
- Compartment pressure measurement
- three pressure should be measured
- resting pressure
- immediate post-exercise pressure
- continuous post-exercise pressure for 30 min
Diagnostic criteria for exertional compartment syndrome?
- resting pressure > 15 mmHg
- immediate post-exercise is > 30 mmHg and/or continuous post-exercise failed to return to normal or remains > 15 mmHg at 15 minutes after cessation of exercise
Treatment of exertional compartment syndrome?
- non-op rarely successful
- operative
- anterior incision for ant/lat compartments
- medial incision if needed for post compartments
- not always a home run
High tibial osteotomy?
- primarily for varus deformity
- 87% success/10yrs
- can be for valgus deformity
- 50-60% success/10yrs
Indications for high tibial osteotomy?
- young and active
- BMI <35
- good vascular status
- only one knee affected
- best results overcorrect 8-10 deg
Contraindications for high tibial osteotomy?
- obese
- inflammatory arthritis
- flex contracture >15 deg
- < 90 deg flexion
- > 20 deg correction needed
- PF arthritis
- unstable knee
- varus thrust gait
Contraindications for varus tibial osteotomy?
- > 12 deg correction needed
- medial compartment arthritis
- loss of medial meniscus
- hypoplastic lateral femoral condyle
- perform femoral osteotomy instead
Contraindications for valgus tibial osteotomy?
- narrow lateral joint space
- loss of lateral meniscus
- lateral tibial subluxation >1cm
- medial compartment bone loss >2-3mm
- varus deformity >10 degrees
Advantage of tibial medial opening wedge osteotomy?
- maintains posterior slope
Complications of closing wedge lateral tibial osteotomy?
- 60% failure rate after 3 years when
- failure to overcorrect
- patients are overweight
- loss of posterior slope
- patella baja
- compartment syndrome
- peroneal nerve palsy (more common in lateral opening wedge osteotomy)
- malunion or nonunion
Most common hamstring tear/injury?
- occurs at myotendinous jxn
- avulsion ischial tuberosity less common
- skeletally immature
- water skiers
Mechanism of hamstring injury?
- hip flexion and knee extension
Hamstring muscle components?
- semimembranous
- semitendinosus
- biceps femoris
long head topic
short head topic
Common characteristics of hamstring muscles?
- originate on ischial tuberosity
- innervated by sciatic (tibial) nerve
- blood supply from inferior gluteal artery and profunda femoral artery
- cross and act upon 2 joints: the hip and knee (except short head of biceps femoris)
Physical exam findings for hamstring tear?
- ecchymosis in posterior thigh
- palpable mass in middle 1/3 of posterior thigh (myotendinous rupture)
- normal hamstring/quadricep ration is 65%
Treatment of hamstring tear?
Myotendinous jxn tear - non-op - protected WB 4 weeks - return to play when size 90% of controlateral thigh Ischial avulsion - ORIF - incision at gluteal crease - protect sciatic nerve - suture anchors
What is scapular plane?
- 30 deg anterior to coronal plane
Ratio of shoulder abduction?
- 2:1
- GH joint 120 deg
- scapularthoracic joint 60 deg
Affect of internal rotation contracture on shoulder abduction?
- cannot abduct > 120 deg
- > 120 deg requires external rotation to avoid GT impingement on acromion
Static restraints of glenohumeral joint?
- glenohumeral ligaments
- glenoid labrum
- articular congruity and version
- negative intraarticular pressure
Dynamic constraints of glenohumeral joint?
- rotator cuff muscles
- biceps tendon
- periscapular muscles
Function of superior glenohumeral ligament?
Resists inf subluxation at 0 deg abduction and neutral rotation
Function of middle glenohumeral ligament?
Resists anterior/posterior translation at 45 deg abduction and ER
Function of posterior inferior glenohumeral ligament?
- resists posterior subluxation at 90° flexion and IR
- tightness leads to internal impingement and increased shear forces on superior labrum (linked to SLAP lesions)
Function of anterior inferior glenohumeral ligament?
- resists anterior/inferior translation at 90° abduction and maximum ER (late cocking phase of throwing)
- anchors into anterior labrum
- forms weak link that predisposes to Bankart lesions
Function of superior inferior glenohumeral ligament?
- most important static stabilizer about the shoulder joint
- 100% increased strain on superior band of IGHL in presence of a SLAP lesion
Function of coracohumeral ligament?
- primary stabilizer to posterior subluxation with shoulder in flexion, abduction, and internal rotation
- limits inferior translation and external rotation at adducted position
Glenoid labrum facts?
- helps create cavity-compression and creates 50% of the glenoid socket depth
- composed of fibrocartilagenous tissue
- blood supply
- suprascapular artery
- anterior humeral circumflex scapular
- posterior humeral circumflex arteries
- labrum recieves blood from capsule and periosteal vessels and not from underlying bone
- anterior-superior labrum has poorest blood supply
Variants of glenoid labrum?
- normal variant
- attached to the glenoid rim and a flat/broad middle glenohumeral ligament
- cord-like middle glenohumeral ligament is present in 86% of population
- sublabral foramen seen in 12%
- Buford complex seen in 1.5%
- meniscoid appearance in 1%
Buford complex?
- variant of glenoid labrum seen in 1.5%
- cordlike middle glenohumeral ligament with attachment to base of biceps anchor and complete absence of the anterosuperior labrum
- attaching a Buford complex will lead to painful and restricted external rotation and elevation.
Rotator interval anatomy?
- capsule, SGHL, coracohumeral ligament that bridge the gap between the supraspinatus and the subscapularis.
- boundaries
- medially by lateral coracoid base
- superiorly by anterior edge of supraspinatus
- inferiorly by superior border of subscapularis
- lateral apex formed by transverse humeral ligament
Contracture of rotator interval?
- seen in adhesive capsulitis
Laxity of rotator interval?
- appears as “sulcus sign” with inferior laxity with the shoulder in adduction
Dynamic role of rotator cuff?
- subscapularis is an important stabilizer to posterior subluxation in external rotation
Dynamic role of biceps tendon in shoulder stability?
- long head of biceps acts as humeral head depressor
- has variable origin from superior labrum
forms weak links that predisposes to SLAP tear
Humeral head facts?
- spheroidal in shape in 90% of individuals
- average diameter is 43 mm
- retroverted 30° from transepicondylar axis of the distal humerus
- articular surface inclined upward 130° from the shaft
Glenoid facts?
- pear-shaped surface with average upward tilt of 5°
- average version is 5° of retroversion in relation to the axis of the scapular body and varies from 7° of retroversion to 10° of anteversion
Coracoid facts?
- anatomic landmark (lighthouse) for deltopectoral approach
- coracobrachialis, pectoralis minor, and short head of the biceps attach to the coracoid
Acromion facts?
- 3 ossification centers
- meta (base), meso (mid), and pre-acromion (tip)
- acromiohumeral interval is 7-8mm
- AHI decreased on MRI when pt is supine usually signifies multiple tendon tear.
- acromial morphology
I=flat
II=curved
III=hooked
Humeral head blood supply?
- major blood supply to humeral head
- ascending branch of anterior humeral circumflex artery
- arcuate artery provides
- vessel runs parallel to lateral aspect of tendon of long head of biceps in the bicipital groove
- posterior humeral circumflex artery provides blood supply to a portion of posteroinferior humeral head
Arcuate artery of shoulder?
- interosseous continuation of ascending branch of anterior humeral circumflex artery and penetrates the bone of the humeral head
Little Leaguer’s Shoulder?
- Salter Harris Type I physeal injury to proximal humerus in adolescent pitchers
and tennis players - arm overuse causes repetitive microtrauma
- from high loads of torque
- breaking pitches are implicated
Signs/symptoms of Little Leaguer’s shoulder?
- arm and shoulder pain with throwing
- worse in late cocking or deceleration phases
- pain resolves with rest
- may be associated with decreased velocity and control
- point tenderness over shoulder physis
- pain reproduced with shoulder rotation
Imaging of Little Leaguer’s shoulder?
- X-ray may show physeal widening or metaphyseal bony changes
- MRI may show edema
Treatment of Little Leaguer’s shoulder?
- avoid pitching 2-3 months
- PT for RC strengthening/post capsule stretching
- correct pitching mechanics
- avoid breaking balls
- pitch counts
Complications of Little Leaguer’s shoulder?
- physeal growth arrest
- angular deformity
Piriformis muscle syndrome?
- extrapelvic compression of sciatic nerve
- aka deep gluteal syndrome
- entrapment anterior to piriformis muscle or posterior to obturator internus/gemelli complex
- at level of ischial tuberosity
Sings/symptoms of piriformis syndrome?
- nonspecific and include pain in the posterior gluteal region and migrating down the back of the leg
- pain may be burning or aching in nature similar to sciatica symptoms
- FAIR test (flexion, adduction, and internal Rotation of hip) can reproduce symptoms
- maneuver places piriformis muscle on tension
Imaging for piriformis syndrome?
- unremarkable
- EMG can diagnose sciatic pathology
Treatment of piriformis syndrome?
- mainstay is non-op
- rest, PT, injections
- operative tx for refractory cases to release piriformis and sciatic nerve neurolysis
Most common anatomy of sciatic nerve as it exits pelvis?
- single nerve anterior to piriformis and posterior to obturator internus and gemelli
Most common anatomic variant of sciatic nerve as it exits pelvis?
- split nerve, one anterior to piriformis and one through piriformis