Musculoskeletal Flashcards
Helpful videos
BONE AND CARTILAGE TUMOURS https://www.youtube.com/watch?v=wezFzUX-UWY
METABOLIC BONE DISEASE
https://www.youtube.com/watch?v=dmkuUXOZ4EQ
OSTEOPOROSIS
https://www.youtube.com/watch?v=jUQ_tt_zJDo
OA
https: //www.youtube.com/watch?v=sUOlmI-naFs
https: //www.youtube.com/watch?v=sUOlmI-naFs&t=23s
RA
https://www.youtube.com/watch?v=EB5zxdAQGzU
BONE TUMOURS
https://www.youtube.com/watch?v=MgWRqBtXzI0
Fracture vocab
STRESS
Fatigue: abnormal stress on normal bone (cross country runner)
Insufficiency: normal stress on abnormal bone (osteoporotic)
PATHOLOGIC
Fracture through lytic/sclerotic bone lesion.
OPEN/COMPOUND
Fracture associated with open wound.
Fracture healing
BONE HEALING Inflammatory, reparitive and remodelling phases. At days 7-14 there is granulation tissue between bone fragments making bone more lucent. Phalanges heal 3 weeks Most things heal 6-8 weeks Tibia heals 10 weeks
DELAYED
Fracture not healed within expected time frame (usually twice as long as expected)
NON UNION
Fracture not going to heal without intervention, usually 6-9 months
MALUNION
Union in poor anatomic position
RISK FACTORS FOR DELAY
Vit D deficiency (vital role in calcium uptake and metabolism). Gastric bypass alters calcium resorption causing secondary hyperparathyroidism. Drugs/meds such as tobacco, NSAIDS and steroids.
Compressive vs tensile side
Fractures of compressive side of bone are compressed together and do well with healing. Eg posterior tibial shaft or medial femoral neck
Fractures of tensile side are pulled apart and dont heal well. Eg anterior tibia and lateral femoral neck
SONK
Spontaneous osteonecrosis of the knee.
Incorrectly named, actually insufficiency fracture of femoral condyle. Old ladies with sudden rising from chair etc. Favors medial femoral condyle (maximum weight bearing). Unilateral in old lady without trauma. ssociated with meniscal injury. Lots of oedema
Classic stress fractures
CALCANEAL
Most fractured tarsal bone, usually intra-articular. Stress fracture will have fracture lines perpendicular to trabecular lines.
NAVICULAR
Runners who run on hard surfaces. High risk AVN
MARCH
Metatarsal stress fracture. Military recruits marching all day.
High vs low risk stress fractures for healing
HIGH RISK Femoral neck tensile side Transverse patella Anterior tibial 5th metatarsal talus Tarsal navicular Sesamoid great toe
LOW RISK Femoral neck compressive side Longitudinal patella Posteromedial tibia 2nd and 3rd meatarsal calcaneus
Scaphoid fracture
Most common carpal fracture. Adolescents and young adults. Blood flow retrograde due to cartilage covering of majority of bone. Proximal at risk for AVN (first sign sclerosis) and non union. Usually fracture at waist.
TRANS SCAPHOID PERILUNATE
Perilunate dislocation have high association with scaphoid fracture 60%
SCAPHOLUNATE LIGAMENT DISRUPTION
Gap of >3mm. Seen in 10-30% distal radial/carpal fractures. SL ligament has 3 bands, volar dorsal and middle. Dorsal is most important for stability. Disruption predisposes to DISI deformity.
HUMPBACK DEFORMITY
Angulation of proximal and distal fragments in setting of waist fracture. Can progress to collapse and non union. Associated with DISI
SLAC and SNAC
SCAPHOID-LUNATE ADVANCE COLLAPSE
Occurs with injury to the SL ligament (or degeneration via CPPD)
SCAPHOID NON-UNIONADVANCED COLLAPSE
Occurs with scaphoid fracture
Scaphoid always wants to rotate in flexion, SL only thing preventing this. If this ligament breaks scaphoid goes into flexion and messes up dynamics. Radioscaphoid first to develop degenerative change. Capitate will migrate proximally and eventual DISI deformity
Scapholunate ligament tear
Terry Thomas on XR. SL has volar, middle and dorsal with dorsal band being most important for carpal stability. If tear, carpal bones will migrate away from each other.
Predisposes to DISI deformity.
DISI vs VISI
DORSAL INTERCALATED SEGMENTAL INSTABILITY
Dorsiflexion instability. After radial sided injury (scapholunate side) the lunate becomes free of stabilizing force of the scaphoid and rocks dorsally. More common as SL tear is common. Widening of SL angle with dorsiflexion of lunate. Angle >60 degrees.
VOLAR INTERCALATED SEGMENTAL INSTABILITY
Volar flexion instability. After ulnar sided injury (lunotriquetral side) the lunate no longer has stablizing force of LT ligament and gets ripped volar with scaphoid. Uncommon. Narrowing of SL angle with volar flexion of lunate and scaphoid. Angle <30
Carpal dislocations
SL DISSOCIATION
SL >3mm. Clenched fist view can worsen. Chronic SL dissociation can cause SLAC wrist.
PERILUNATE DISLOCATION
Lunate stays put and bones around it dislocate dorsally. 60% scaphoid fracture associated.
MID CARPAL DISLOCATION
Both lunate and capitate lose radial alignment. Associated with triquetro-lunate interosseous ligament disruption. Associated with triquetral fracture.
LUNATE DISLOCATION
Lunate dislocates volar, others stay in normal alignment. Most severe. happens with dorsal radiolunate injury.
Synovial spaces trivia
GLENOHUMERAL JOINT AND SUBACROMIAL BURSA
Should not communicate, implies full thickness cuff tear
ANKLE JOINT AND COMMON PERONEAL TENDON SHEATH
Should not communicate, implies tear of calcaneofibular ligament
ACHILLES TENDON AND POSTERIOR SUBTALAR JOINT
Should not communicate. Achilles tendon does not hav true tendon sheath
PISIFORM RECESS AND RADIOCARPAL JOINT
Should communicate and can use either for arthrography.
TFCC
Primary stabilizer and shock absorber of distal radiolnar joint DRUJ.
5 COMPONENTS Triangular fibrocartilage (articular disc) Volar and dorsal radioulnar ligaments Meniscus homologue UCL Tendon sheath of ECU
TFCC INJURIES
Acute: fall onto extended wrist
Chronic degeneration: More common and involved with positive ulnar variance and ulnar impaction.
Ulnar sided injuries more likely to heal due to better vascularity.
Ulnar variance
Can occur congenitally or be acquired from impaction/fracture
POSITIVE
Ulnar impaction syndrome (ulnolunate). Get cystic change in lunate and TFCC tears
NEGATIVE
Get AVN of lunate (Kienbock). Sclerotic XR and low T1 MRI
Distal radius fractures
COLLES
Distal metaphysis fracture, extra-articular with dorsal angulation. Dinner for deformity. Old lady fracture. Ulnar styloid fracture commonly associated.
SMITH
Distal metaphysis fracture, extra-articular with volar angulation. Younger patient, ulnar styloid fracture associated. Intra-articular variant called reverse Barton. Can result in carpal tunnel if residual volar angulation.
BARTON
Intra-articular dorsal radius fracture ‘radial rim’. Fracture involves either dorsal radius or volar radius (more common). Radiocarpal dislocation is hallmark. Surgical repair with high rate redislocation and mal-union.
HUTCHINSON/CHAUFFER
Intra-articular fracture of radial styloid. Association with SL dissociation and perilunate dislocation
Radial tilt
Normal radial tilt of about 11 degrees. Usually wont accept past neutral. True lateral to measure.
Delayed EPL rupture after radial fracture
Distal radial fracture can alter morphology of Listers tubercle (dorsal aspect separating 2nd and 3rd extensor compartment) and result in delayed rupture EPL. More common after non displaced fracture.
Extensor tendons
6 extensor compartments
First compartment (APL and EPB) are affects in de Quervains
Third compartment has EPL which courses by Listers tubercle and can rupture after fracture.
Sixth compartment (ECU) can get an early tenosynovitis in RA
Carpal tunnel
Bounded by pisiform, scaphoid tubercle, hamate hook and trapezium tubercle. Transverse carpal ligament overlies. 4 x FDP 4 x FDS 1 x FPL 1 x Median nerve
NOT IN TUNNEL
FCR, FCU, PL, FPB
Carpal tunnel syndrome
Median nerve distribution, often bilateral, may have thenar muscle atrophy. Enlargement of nerve on USS. Usually from repetitive trauma but can be from dialysis, pregnancy, DM and hypothyroidism. May have increased signal in nerve or it may look swollen/smashed/flattened. Bowing of flexor retinaculum.
Guyons canal syndrome
Entrapment of ulnar nerve as it goes through Guyons canal (formed by pisiform and hamate). Handle bar palsy. Fracture of hook of hamate can also cause this.
Sub sheath tear/dislocation
Traumatic dislocation to ECU (compartment 6) out of its normal groove at level of distal ulna. Subluxation implies rupture of overlying sheath. Medial dislocation
Vaughan Jackson syndrome
Sequential extensor tendon ruptures seen in worsening RA of DRUJ. Progresses ulnar to radial starting at 5 EDM (-4-3-2)
Tenosynovitis
Inflammation of tendon manifesting as increased fluid around tendon.
DIFFUSE
TB OR NON TB MYCOBACTERIAL
Hand and wrist most common. Diffuse and exuberant, spares muscles. Immunocompromised. Rice body in TB
RHEUMATOID
Multiple flexor tendons or isolated ECU. Vughan Jackson syndrome as above. Can present before bone findings
FOCAL
PENETRATING INFECTION
Surgical emergency as can spread rapidly to common wrist flexors. Increased pressure in sheath can cause necrosis of tendons. Delayed treatment do bad.
OVERUSE
DEQUERVAINS
Mommy thumb. New mom holding baby. First extensor compartment EPB and APL. Increased fluid in first compartment. Pain on passive ulnar deviation
INTERSECTION SYNDROME
Repetitive use seen in rowers. Fist extensor tendons intersect second extensory compartment tendons. ECR brevis and longus tenosynovitis.
DRUMMER WRIST
Tenosynovitis of third compartment EPL.
Bennett and Rolando fractures
Fractures of base of first metacarpal. Rolando fracture is comminuted, Bennett isnt. Pull of APL is what causes dorsolateral dislocation in Bennett.
Gamekeepers thumb
Avulsion fracture at base of proximal first phalanx associatwd with UCL disruption. Stener lesion is when adductor tendon aponeurosis gets caught in torn edges of UCL - displaced ligament wont heal right and need an operation. Yoyo appearance on MRI
Trigger finger
Overuse/repetitive trauma causes scarring in flexor tendon sheath. Stenosing tenosynovitis. Thick sheath
Forearm fractures
MONTEGGIA (MUGR)
Fracture of prox ulna with anterior dislocation radial head.
GALLEAZI (MUGR)
Radial shaft fracture with DRUJ dislocation
ESSEX LOPRESTI
Fracture of radial head and anterior dislocation at DRUJ. Unstable fracture with rupture of interosseous membrane.
Cubital tunnel syndrome
Several causes, most commonly repetitive valgus stress. On MCQ answer is accessory aconeus.
Anconeus is muscle on lateral elbow which doesnt do much. Can have accessory muscle (anconeus epirochlearis) on medial elbow which will compress ulnar nerve. Site where ulnar nerve passes beneath cubital tunnel called epicondylo-olecranon ligament or Osbornes ligament
Epicondylitis
LATERAL (Tennis elbow)
More common. Repetitive extension. Extensor tendon injury (ECRB). Radial collateral ligament tears due to varus stress
MEDIAL (Golfers elbow)
Repetitive flexion. Common flexor tendon and ulnar nerve may enlarge from chronic injury
Partial ulnar collateral ligt tear
Throwers and people with valgus overload get these. Ulnar collateral ligt attaches on medial coronoid at sublime tubercle.
Ligament has 3 bundles with anterior most important. Partial UCL tear gets “T sign” with fluid extending medial to tubercle.
Little leaguer elbow
Repetitive chronic injury to medial epicondyle. Stress fracture, avulsion or delayed closure of medial epicondylar apophysis. Usually associated with UCL injury.
Valgus overload syndrome is seen in throwers and consists of lateral compression, medial tension and posterior sheer. Results in UCL injury, arthritis at posterioe humerus/ulna and OCD at capitellum
Random elbow
EPITROCHLEAR LYMPHADENOPATHY
Classic look for cat scratch disease.
DIALYSIS ELBOW
Olecranon bursitis from constant pressure on area relating to positioning of arm during treatment
Biceps tear
Partial or complete. Complete tear usually occurs in shoulder with avulsion off labrum or in bicipital groove.
PARTIAL TEAR
Often associated with bicipitoradial bursitis. Painful mass antecubital fossa. Popeye deformity.
Triceps rupture
Least common tendon in body to rupture. Tenidnopathy fairly uncommon also. Salter Harris 2 fracture of olecranon is classic scenario.
Mimics include striated appearance of insertion at olecranon and olecranon bursitis.
Elbow dislocation
Second most commonly dislocated joint in adult. Usually associated with radial head and coronoid process fracture.
Instability in the elbow (posterior rotary instability) is described in a pattern starting in posteriolateral corner with tearing of lateral UCL.
Shoulder dislocation
ANTEROINFERIOR
Most common 90%. Hill Sachs posterolateral humerus best seen on internal rotation. Bankart on anteroinferior labrum. GT avulsion in 10% dislocation in >40yo.
POSTERIOR DISLOCATION
Uncommon. Seizure, electrocution. Rim sign is no overlap between glenoid and humeral head. Trough sign is reverse Hillsachs with impaction on anterior humerus. Light Bulb sign is arm locked in internal rotation on all views
INFERIOR DISLOCATION
Luxatio erecta. Uncommon. Arm sticking up. 60% get neurologic injury.
Proximal humerus fracture
Old lady FOOSH. Neer classification for how many parts humerus is in. Treat 3 or 4 part wit reverse TSJR
Post op shoulder
4 TYPES
Humeral head resurfacing, hemiarthroplasty, TRJR and RTSJR
INTACT CUFF
If glenoid intact get resurfacing or hemi.
If glenoid deficient get TSJR
CUFF TRASHED
If glenoid intact get hermi or RTSJR
If glenoid deficient get RTSJR
COMPLICATIONS/TRIVIA
Most common complication of TSJR is loosening of glenoid component and anterior escape following subscapularis failure.
RTSJR heavily relies on deltoid. Posterior acromion fracture from excessive deltoid tugging can occur.
Impingement
Overuse. 2 types with 2 subdivisions
EXTERNAL PRIMARY (abnormal coracoacromial arch)
Hoked acromion
Subacromial osteophyte
Thickening subacromial ligament
Subcoracoid impingement (of subscap between coracoid process and LT) either congenital or post traumatic
EXTERNAL SECONDARY (normal coracoacromial arch) Multidirectional glenohumeral instability resulting in microsubluxation and repetitive microtrauma. Generally bilateral and with joint laxity. Increase shoulder volume with injection.
INTERNAL POSTERIOR SUPERIOR
Junction of supra and infra tendons contacts posterosuperior glenoid and gets pinched between labrumand GT. Athletes with overhead movements. Abd ext rot position.
INTERNAL ANTERIOR SUPERIOR
Abd and int rot. Undersurface of biceps and subscap impinge against anterior superior glenoid rim.
Impingement cont
SUBACROMIAL IMPINGEMENT most common resulting from attrition or coracromial arch. Damages supraspinatus tendon.
SUBCORACOID IMPINGEMENT lesser tuberosity and coracoid do pinching, damages subscapularis
POSTEROSUPERIOR INTERNAL impingement is athletes with overhead movements. Greater tuberosity and posterosuperior labrum do pinching, damages infraspinatus and posterior fibres supraspinatus.