Musculoskeletal System

Abnormal Physical Examination Findings in Musculoskeletal Injuries

Test Injury
Schober test Ankylosing spondylitis
Neer test Subacromial impingement
Hawkins test Subacromial impingement
Empty & Full can test Supraspinatus
Drop arm test Supraspinatus
Lift-off test Subscapularis
Apprehension test Glenohumeral joint
O'Brien test SLAP tear
Popeye sign Biceps tendon tear
Speed test Bicipital tenosynovitis
Yergason test Bicipital tenosynovitis
Tinel sign Carpal tunnel syndrome
Phalen test Carpal tunnel syndrome
Finkelstein test De Quervain's tenosynovitis
Trendelenburg test Gluteus medius
Gluteus minimus
Tensor fascia latae
FABER test Sacroilius joint
FADIR test Piriformis
Lachman test Knee ACL
Anterior & Posterior drawer test Knee ACL & PCL
Valgus & Varus stress test Knee MCL & LCL
McMurray test Knee meniscus
Apley Test Knee meniscus
Patellar grind test Patellofemoral pain syndrome
Thompson test Achilles tendon tear

Muscle Relaxants

Antispastics

Mechanism Medication Indications
Ca channel blockers Dantrolene Malignant hyperthermia
NMS
ACh release inhibitors Botulinum toxin Muscle relaxant
NM agonists Succinylcholine Anesthesia
NM antagonists Atracurium
Rocuronium
Anesthesia
α2 agonists Tizanidine Multiple sclerosis
Cerebral palsy
NMDA antagonists Riluzole Amyotrophic lateral sclerosis (ALS)
GABAB agonists Baclofen Multiple sclerosis
Cerebral palsy

Antispasmodics

  • Carisoprodol
  • Chlorzoxazone
  • Cyclobenzaprine
  • Metaxalone
  • Methocarbamol
  • Orphenadrine

Types of Fracture

Salter-Harris Classification of Physeal Fractures

Peripheral Nerve Injuries

Nerve Injury Muscles Signs
Brachial plexus Clavicle fracture
Pancoast tumor
Arm Thoracic outlet syndrome
Upper trunk:
Suprascapular nerve
Axillary nerve
Musculocutaneous nerve
Clavicle fracture
Lateral traction on neck
Supraspinatus
Infraspinatus
Teres minor
Deltoid
Biceps brachii
Erb palsy
Waiter's tip
Lower trunk:
Median nerve
Ulnar nerve
Radial nerve
Clavicle fracture
Upward force on arm
Flexor digitorum profundus
Lumbrical muscle
Klumpke palsy
Thoracic outlet syndrome
Total claw hand
Long thoracic nerve Clavicle fracture Serratus anterior Winged scapula
Axillary nerve Anterior shoulder dislocation
Proximal humerus fracture
Deltoid
Teres minor
-
Median nerve :: proximal Supracondylar humerus fracture Flexor digitorum profundus :: 1st & 2nd Pope's blessing
Median nerve :: distal Carpal tunnel syndrome Lumbrical muscle :: 1st & 2nd Median claw hand
Ulnar nerve :: proximal Medial epicondyle fracture
Cubital tunnel syndrome
Flexor digitorum profundus :: 3rd & 4th OK gesture
Ulnar nerve :: distal Hook of hamate fracture
Guyon canal syndrome
Lumbrical muscle :: 3rd & 4th Ulnar claw hand
Radial nerve Midshaft humerus fracture Posterior compartment of forearm Saturday night palsy
Wrist drop
Obturator nerve Anterior hip dislocation Medial compartment of thigh -
Femoral nerve - Anterior compartment of thigh -
Common fibular nerve Fibular neck fracture Anterior compartment of leg
Lateral compartment of leg
Foot drop
Tibial nerve Baker cyst
Tarsal tunnel syndrome
Posterior compartment of leg -
Sciatic nerve Posterior hip dislocation Posterior compartment of thigh -
Superior gluteal nerve - Gluteus medius
Gluteus minimus
Tensor fascia latae
Trendelenburg gait

Fall Onto an Outstretched Hand (FOOSH) Injuries

  • Clavicle fracture
  • Rotator cuff injury
  • Monteggia fracture
    • Proximal ulnar fracture
    • Radial head dislocation
  • Galeazzi fracture
    • Distal radial fracture
    • Distal radioulnar joint dislocation
  • Colles fracture
    • Distal radial fracture
  • Scaphoid fracture
  • Hook of hamate fracture

O'Donoghue Unhappy Triad

  • Anterior cruciate ligament (ACL)
  • Medial collateral ligament (MCL)
  • Medial meniscus tear

Screening for Developmental Dysplasia of Hip (DDH)

  • Barlow test
  • Ortolani test

Management of Developmental Dysplasia of Hip (DDH)

Age Management
< 6 months Pavlik harness
6 ~ 18 months Closed reduction
Hip spica cast
> 18 months Open reduction
Hip spica cast

Ottawa Ankle Rules

  • Medial malleolus :: posterior & tip
  • Lateral malleolus :: posterior & tip
  • Midfoot
  • Inability to bear weight

Management of Scoliosis

Curvature Management
10° ~ 20° Observation
20° ~ 40° Spinal bracing
> 40° Spinal fusion

Etiology of Bone Disorders

Disorder PTH Ca P ALP Etiology
Osteopetrosis - - - - -
Osteopenia
Osteoporosis
- - - - -
Paget disease - - - -
Osteitis fibrosa cystica ↑ (1°) 1° Hyperparathyroidism
Renal osteodystrophy ↓ (1°) ↑ (1°) 2° Hyperparathyroidism
3° Hyperparathyroidism
Rickets
Osteomalacia
↓ (1°) ↓ (1°) Vitamin D deficiency
Hypophosphatemic rickets - - ↓ (1°) -
Albright hereditary osteodystrophy ↓ (1°) ↑ (1°) Pseudohypoparathyroidism (PHP)
Polyostotic fibrous dysplasia - - - - McCune-Albright syndrome

Presentation of Osteogenesis Imperfecta

  • Bone fratures
  • Blue sclerae
  • Hearing loss :: conductive
  • Opalescent teeth

Bone Density Scores

Score Condition
-1 ~ +1 Normal
-2.5 ~ -1 Osteopenia
< -2.5 Osteoporosis

Medications for Osteoporosis

Mechanism Medication
Estrogen modulators Raloxifene
PTH antagonists
Osteoblast inducers
Teriparatide
Osteoclast inhibitors Bisphosphonates [-Dronates]
RANKL inhibitors Denosumab

Indications for Bisphosphonate Therapy

  • Osteopenia w/
    • History of fracture
    • 10-year risk for
      • Major osteoporotic fracture > 20%
      • Hip fracture > 3%
  • Osteoporosis
  • Paget disease
  • Multiple myeloma
  • Bone metastasis

Synovial Fluid Analysis

  WBCs PMNs
Normal < 200/mm3 < 25%
Non-inflammatory - -
Inflammatory > 50%
Infectious > 75%

Empirical Antibiotics for Septic Arthritis

  • Vancomycin
  • 3° Cephalosporins

Etiology of Non-infectious Inflammatory Arthritis

  • Crystal arthropathy
  • Rheumatoid arthritis
  • Seronegative spondyloarthropathy
  • Polymyositis
  • Dermatomyositis
  • Systemic lupus erythematosus (SLE)
  • Henoch-Schonlein purpura (HSP)
  • Complex regional pain syndrome (CRPS)
  • Polymyalgia rheumatica
  • Sarcoidosis

Comparison Between Gout and Pseudogout

  Gout Pseudogout
Deposit Uric acid Calcium pyrophosphate
Shape Needle Rhomboid
Birefringent - +
Presentation Tophus Chondrocalcinosis

Medications for Gouty Arthritis

Mechanism Medication
COX inhibitors NSAIDs
NF-κB inhibitors Corticosteroids
Microtubule inhibitors Colchicine
Xanthine oxidase inhibitors Allopurinol
Febuxostat
Urate transporter inhibitors Probenecid
Urate oxidase [Uricase] Rasburicase
Pegloticase

Pathogens of Osteomyelitis

  • Staphylococcus aureus
  • Staphylococcus epidermidis
  • Pseudomonas aeruginosa
  • Salmonella
  • Anaerobes
  • Candida

Empirical Antibiotics for Osteomyelitis

  • Anti-staphylococcal penicillin
    Anti-MRSA
  • Anti-pseudomonal β-lactams
    Fluoroquinolones

Bone Tumors

Origin Tumors Location
Bone Giant cell tumor [Osteoclastoma] Epiphysis
  Osteoid osteoma [Osteoblastoma] Diaphysis
  Osteosarcoma Metaphysis
Cartilage Chondroblastoma Epiphysis
  Enchondroma Metaphysis
  Osteochondroma Metaphysis
  Chondrosarcoma Metaphysis
PNET Ewing sarcoma Diaphysis
Marrow Multiple myeloma Diaphysis