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
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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 |