Popliteal (Baker) cyst
- Definition: swelling in the popliteal fossa between the medial head of the gastrocnemius muscle and the semimembranosus muscle that contains synovial fluid (often communicates with synovial space of the knee joint)
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Etiology
- Inflammation of the synovium, which stimulates excessive production of synovial fluid
- Risk factors: inflammatory, degenerative, or traumatic intra-articular changes in the knee joint (e.g., rheumatoid arthritis, osteoarthritis, meniscal lesions)
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Clinical features
- Most cysts are asymptomatic and detected only incidentally on imaging.
- If symptomatic: Swelling of the popliteal fossa; and posterior knee pain are common.
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Diagnostics
- Usually a clinical diagnosis
- Plain x-ray or ultrasound; are commonly used as initial imaging modalities and reveal a soft tissue mass (x-ray) or an anechoic lesion (ultrasound).
- MRI can be helpful in some cases
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Treatment
- Asymptomatic cysts do not require treatment.
- Symptomatic cysts
- Treat underlying pathology of the knee joint
- If symptoms persist, intra-articular injection of glucocorticoids can control inflammation.
- Surgical resection for symptomatic cysts that persist despite treatment.
- Complications: cyst enlargement and rupture → leakage of synovial fluid caudally into the lower leg muscles
Rupture of a popliteal cyst may mimic a deep vein thrombosis!
Bursitis
- Definition: inflammation of a bursa
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Etiology
- Local trauma: fall on the joint, overuse injury (e.g., excessive kneeling or leaning on the elbows for long period of time while working at a desk)
- Systemic diseases (e.g., rheumatoid arthritis, gout)
- Infection
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Main types/localizations
- Olecranon bursitis: inflammation of the bursa of the elbow joint that is often caused by leaning on the elbow for long periods of time
- Subacromial bursitis: inflammation of the bursa located between the acromion and deltoid muscle (superiorly) and the head of the humerus (inferiorly) that is often caused by repetitive overhead motion
- Prepatellar bursitis: inflammation of the prepatellar bursa located between the skin and the patella that is most commonly caused by chronic strain on flexed knees (also referred to as “housemaid's knee”) or repeated trauma (e.g., falling on the knee)
- Pes anserine bursitis: inflammation of the bursa of the inner knee that is often caused by stress due to conditions such as obesity and degenerative joint disease
- Clinical features: local joint swelling, erythema, warmth, and limited range of motion due to pain
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Diagnostics
- Usually, clinical diagnosis is sufficient.
- Aspiration of superficial bursas to rule out infection or gout
- X-ray (or less commonly, MRI) may be considered to exclude bone involvement if suspected.
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Treatment
- Rest, ice or heat, elevation, and NSAIDs
- Antibiotics if septic
- Operative measures may become necessary (e.g., drainage of pus, bursectomy; ) for recurrent bursitis that fails to respond to conservative management.
- Complications: septic (purulent) bursitis, usually caused by S. aureus
Meniscal cyst
- Definition: a collection of synovial fluid in or around the meniscus
- Etiology: secondary to a meniscal tear → synovial fluid becomes encysted
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Clinical features
- Pain and swelling
- Decreased range of motion of the knee
- Chronic meniscal tears → locking (decreased extension of the knee) and popping (knee joint laxity)
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Diagnostics
- Clinical diagnosis
- MRI can aid in management if surgical intervention is indicated.
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Treatment [1]
- Conservative management with rest, pain control, and crutches
- Surgical intervention is indicated in refractory cases that do not respond to conservative management, or if there are mechanical symptoms (locking, popping) or tears in an avascular zone.
Stress fracture
- Definition: complete bone fracture caused by repetitive stress without underlying bone pathology or disease affecting the bone
- Etiology: Increased load or frequency of physical activity can facilitate bone resorption.
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Risk factors
- Repetitive high-intensity physical activity
- Improper technique during physical activity
- Ill-fitting footwear
- Caloric restriction; , especially in patients with anorexia nervosa
- Decreased bone density (e.g., bisphosphonates use)
- Calcium deficiencies
- Female sex
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Clinical features
- Most common in the lower extremities (metatarsals, also the tibia; , fibula, and navicular bones)
- Less common in the upper extremities (humerus, scapula, ribs)
- Acute pain with activity (worsens with loading or stress, relieved with rest)
- Bone tenderness, erythema, or soft tissue swelling
- Diagnostics
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Treatment
- Pain control: acetaminophen, ice packs
- Rest; , physical therapy, and risk factor modification (improved nutrition, calcium, and vitamin D supplementation)
- Surgery in refractory cases
Genu valgum
- Definition: valgus (lateral) misalignment of the knee, resulting in a knocked knee deformity
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Etiology
- Physiological
- Normal at 2–5 years of age
- Associated with normal stature, bilateral symmetry, and no clinical symptoms
- Pathological: post-traumatic; (e.g., distal femoral fracture), metabolic disorders; (e.g., rickets; , mucopolysaccharidosis), skeletal dysplasias, or neoplasms
- Physiological
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Clinical features of pathological valgus
- Unilateral valgus that is progressive (after 4–5 years of age) or persistent (after 7 years of age)
- Severe valgus
- Gait abnormalities and congenital flat feet
- Features suggestive of an underlying disease (e.g., unilateral deformity, short stature, fever, knee or foot pain, abnormal swelling)
- Diagnostics: if pathological valgus is suspected, imaging and/or metabolic evaluation to determine underlying disease
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Treatment
- Physiological valgus may improve by the age of 7 years and should be managed with close observation and reassurance.
- Medical treatment of the underlying pathology
- For persistent symptoms in patients older than 10 years, surgery is indicated.
Genu varum
- Definition: varus (medial) misalignment of the knee, resulting in a bowleg deformity
- Epidemiology: common in children
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Etiology
- Physiological
- Normal at birth
- Associated with normal stature, bilateral symmetry, and no clinical symptoms
- Pathologic varus: result of Blount disease, metabolic disorders (e.g., rickets; ), skeletal dysplasias, or neoplasms
- Physiological
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Clinical features of pathological varus
- Bowing that is progressive or persistent (after 3 years of age)
- Severe bowing
- Gait abnormalities
- Features suggestive of an underlying disease (e.g., unilateral deformity, short stature, fever, knee or foot pain, abnormal swelling)
- Diagnostics: if pathological varus is suspected, imaging and/or metabolic evaluation to determine underlying disease
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Treatment
- Physiological varus usually improves by 24 months and should be followed by close observation.
- Treatment of the underlying pathology
- For persistent symptoms; that do not respond to medical management, surgery is indicated.
Greater trochanteric pain syndrome
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Etiology: gluteus medius or gluteus minimus muscle tendinopathy
- Involvement of the trochanteric bursa is possible, although rare.
- May also be associated with snapping hip (coxa saltans) or trauma
- Clinical features
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Diagnostics: Imaging may be indicated if the diagnosis is unclear, if underlying pathology is suspected, or in cases that do not respond to initial treatment. [2]
- X-ray: used to rule out other causes of hip pain (e.g., osteoarthritis, femoral neck fracture)
- Ultrasound: may show thickening of the iliotibial band, tendinosis of the gluteal muscles, and/or trochanteric bursitis [3]
- MRI: to evaluate for an underlying pathology or prior to surgery
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Treatment [2]
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Mainly conservative
- Physical therapy and relative rest
- Oral NSAIDs or glucocorticoid injections for pain/discomfort
- Management of comorbidities, including back pain, obesity, and leg length discrepancy
- In refractory cases; (without improvement after > 12 months of conservative management), surgery is indicated (e.g., bursectomy). [4]
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Mainly conservative
Forearm fractures
Colles and smith fractures
- See “Distal radius fractures.”
Monteggia fracture
- Definition: proximal (or middle) ulnar fracture with concomitant dislocation of the radial head
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Mechanism of injury
- Low-energy trauma, e.g., fall on outstretched and pronated forearm
- High-energy trauma, e.g., direct blow to the forearm from a motor vehicle accident
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Clinical features
- Pain, deformity, and limited range of movement of the elbow joint
- Paresthesia at or below the elbow joint
- Possibly nerve injury: most commonly posterior interosseous nerve palsy
- Diagnostics: X-ray shows a fracture of the proximal (or middle) ulna with dislocation of the radial head (dislocation can be anterior, posterior, or lateral).
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Treatment
- In children with uncomplicated fractures: closed reduction and casting
- In adults or complicated fractures : open reduction and internal fixation (plating, K-wire fixation)
Galeazzi fracture
- Definition: radial shaft fracture with disruption of the distal radioulnar joint
- Epidemiology: more common in children
- Mechanism of injury: fall on outstretched and pronated forearm
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Clinical features
- Pain, deformity, and limited range of movement at the distal-third radial fracture site and wrist joint
- Anterior interosseous nerve (AIN) palsy can occur.
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Diagnostics: x-ray
- Shows a fracture of the junction of the distal third and middle third of the radius shaft with subluxation or dislocation of the distal radioulnar joint
- A tear in the interosseous membrane can only be seen indirectly on the x-ray.
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Treatment
- In children with uncomplicated fractures: closed reduction and casting
- In adults or complicated fractures : open reduction and internal fixation (plating, K-wire fixation)
Other forearm fractures
- Greenstick fracture of the radius or ulna
- Parry fracture: isolated fracture of the ulna (typically a defensive injury)
- Complete forearm fracture: fracture of the radial and ulnar shafts
- Essex-Lopresti injury: a fracture of the radial head, disruption of the interosseous membrane, and dislocation of the distal radioulnar joint
- Barton fracture
- Hutchinson fracture
Ganglion cyst
- Definition: benign mucin-filled cyst that develops along tendons or joints and has no true epithelial lining
- Epidemiology: most common type of hand mass
- Location: : wrist and fingers (most common at the dorsal wrist)
- Pathophysiology: herniation of connective tissue; associated with repetitive trauma and mucoid degeneration of periarticular structures → sac that is lined with synovial cells and contains paucicellular connective tissue (typically mucin)
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Clinical features
- Usually asymptomatic but can occasionally cause joint pain
- Fluctuant, transilluminant swelling
- Can lead to nerve compression, which may cause numbness, weakness, or tingling (e.g., Guyon tunnel syndrome)
- Differential diagnoses: epidermoid cysts, lipoma, rheumatoid nodules, infectious tenosynovitis, soft tissue tophus
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Treatment
- Asymptomatic: observation (ganglion cysts often regress spontaneously)
- Symptomatic: aspiration or surgical resection
References:[5]
Plantar fasciitis
- Definition: inflammation of the plantar aponeurosis
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Etiology
- Unknown
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Risk factors include:
- Foot deformities: pes cavus, pes planus
- Training errors: excessive training, sudden changes in training intensity, inappropriate equipment
- Occupations associated with long periods of standing and weight-bearing
- Obesity
- Clinical features
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Diagnostics
- Point tenderness along the plantar fasciitis
- Ultrasound: plantar fascia thickening, edema at the insertion at the calcaneus
- Differential diagnosis
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Treatment
- Plantar foot and calf stretching exercises
- Heel shoe inserts
- Avoid aggravating movements (e.g., running)
- NSAIDs, glucocorticoid injection