MSK: BOARDS AND BEYOND Flashcards
What are the common signs and symptoms of a meniscus injury, and what is the most sensitive physical exam finding?
Patients with a meniscus injury often present with mild to moderate knee swelling, which reduces their range of motion. The most sensitive physical exam finding is joint line tenderness.
What are the menisci, where are they located, and what is their main function?
The menisci (medial and lateral) are C-shaped fibroelastic cartilaginous structures located on the tibia. Their main function is to act as shock absorbers between the femur and tibia, and they also stabilize the joint between these two bones.
How is the McMurray test performed, and what indicates a positive result for a medial meniscus injury?
The McMurray test is performed with the patient lying supine. The examiner passively moves the knee from flexion to extension while externally or internally rotating the tibia. A positive test for a medial meniscus injury includes a palpable pop or click during external rotation of the tibia, which is often painful or uncomfortable for the patient.
Where does the ACL (anterior crusade ligament) originate and insert, and what is its main function?
The ACL originates on the medial wall of the lateral femoral condyle and inserts on the anterior tibia between the intercondylar eminences. Its main function is to resist abnormal anterior tibial motion, providing approximately 85% of the resistance that prevents anterior movement of the tibia.
How are the Lachman and anterior drawer tests performed, and what indicates a positive result in an ACL tear?
The Lachman test is performed with the knee flexed to 20°-30°; a positive result shows increased anterior translation of the tibia relative to the femur. The anterior drawer test is performed with the knee flexed to 90°, applying an anteriorly directed force to the tibia. Increased anterior motion of the tibia in the injured knee compared to the normal side indicates a positive result for an ACL tear.
What is the main blood supply to the ACL, and what symptoms and associated injuries are common in an acute ACL rupture?
The ACL’s main blood supply is the middle genicular artery. Patients often present with a large knee effusion or hemarthrosis, which limits their range of motion. Over half of acute ACL tears are associated with lateral meniscus tears, and patients often have lateral joint line tenderness on physical examination.
Where does the PCL (posterior cruciate ligament) originate and insert, and what is its main function?
The PCL originates on the lateral wall of the medial femoral condyle and inserts on the posterior tibia, just distal to the articular surface. Its main function is to resist posterior translation of the tibia in relation to the femur, preventing backward movement of the tibia.
What is the typical mechanism of injury for a PCL rupture, and what are common causes?
The PCL is most commonly injured when a posteriorly directed force is applied to the tibia. A common cause is motor vehicle accidents, or “dashboard injuries,” where the tibia hits the dashboard and is driven posteriorly relative to the femur.
How is the posterior drawer test performed, and what indicates a positive result for a PCL injury? What are common symptoms?
The posterior drawer test is performed with the patient supine and the knee flexed to 90°, applying a posteriorly directed force on the tibia. Increased posterior translation of the tibia relative to the femur indicates a positive result. Symptoms include large knee effusion, often due to rupture of the middle geniculate artery, and decreased range of motion.
How is the patella attached, and what is its main function?
The patella is attached superiorly by the quadriceps tendon and inferiorly by the patellar tendon. Its main function is to aid in knee extension by increasing the efficiency of the quadriceps muscle pull on the patellar tendon during active knee extension.
What commonly causes a patellar fracture, and what are the typical signs on physical examination?
Patellar fractures commonly result from direct-impact injuries, such as falls or dashboard injuries. Physical examination shows a large knee effusion and tenderness directly over the patella. The patient will have a decreased range of motion in the knee, an inability to actively extend the knee, and difficulty performing a straight leg raise.
How are patellar fractures diagnosed, and what findings are expected on radiographs?
Knee radiographs are useful in diagnosing patellar fractures. A lateral knee radiograph often shows the fracture and any displacement of the fragments. However, on anteroposterior (AP) X-rays, the overlap of the distal femur can make visualizing the fracture challenging.
What is Osgood-Schlatter disease, and what causes it?
Osgood-Schlatter disease is a traction apophysitis of the anterior tibial tubercle of the proximal tibia. It is caused by pulling (traction) on the tibial tubercle, an apophysis, leading to inflammation at this site. Traction apophysitis results from pulling by a ligament or tendon at an ossification center, a site of bone growth in children.
What structures are involved in Osgood-Schlatter disease, and how does it develop?
The patellar tendon inserts onto the tibial tubercle, a secondary ossification center of the proximal tibia. Constant pulling by the patellar tendon irritates the apophysis, causing an inflammatory reaction, which can lead to swelling, pain, and ossific fragmentation (bony fragments) visible on X-rays.
Who is commonly affected by Osgood-Schlatter disease, and what are typical symptoms and activities that worsen it?
Osgood-Schlatter disease is more common in boys and occurs in males ages 12-15 and females ages 8-12. Symptoms include pain and swelling over the tibial tubercle, and activities like jumping, squatting, running, and kneeling exacerbate symptoms.
Lyme disease can affect the knee, but patients complain of ? and not isolated tibial tubercle pain.
knee swelling
The medial collateral ligament (MCL) is most commonly injured with a direct blow to the lateral aspect of the knee. The MCL is the main structure to resist valgus stress between the femur and tibia. Physical examination of an MCL injury will demonstrate
Increased medial joint space widening with a valgus force applied force to the knee.
A patellar tendon rupture is rare in the pediatric and adolescent population. It is much more common in adults following trauma. The patellar tendon originates from the inferior pole of the patella and inserts onto the tibial tubercle. Patients with patellar tendon ruptures have decreased range of motion with an inability to
Actively extend the knee, actively perform a straight leg raise, or maintain passive extension of the knee.
The lateral collateral ligament (LCL) originates from the lateral border of the distal femoral condyle and inserts onto the anterolateral aspect of the proximal fibula. The LCL’s main function is to resist varus stress between the femur and tibia. Physical examination of LCL injuries demonstrates
Increased lateral joint space widening with a varus applies force to the knee.
What is radial head subluxation (nursemaid’s elbow), and what causes it?
Radial head subluxation, or nursemaid’s elbow, occurs when the annular ligament slips over the head of the radius. It primarily affects children aged 1 to 4 and is commonly caused by pulling on the arm, such as swinging children by the arms or grabbing an arm when a child is running away.
How do children with radial head subluxation typically present?
Children with radial head subluxation often refuse to use the affected arm and hold it close to the body with the elbow flexed and the forearm pronated. There is no associated swelling, bony tenderness, or obvious deformity.
Is imaging necessary to diagnose radial head subluxation?
No, x-rays are not necessary to diagnose radial head subluxation, as the condition lacks swelling, bony tenderness, or obvious deformities. Diagnosis is typically made based on history and clinical presentation.
What causes an anterior shoulder dislocation, and how does it typically present?
An anterior shoulder dislocation is usually caused by trauma to an abducted, externally rotated, and extended arm, such as blocking a basketball shot or being tackled while throwing a football. Patients present with shoulder pain, inability to move the affected shoulder, and a loss of the normal, rounded shoulder appearance.
How is an anterior shoulder dislocation diagnosed, and what role does imaging play?
Diagnosis is often clinical, but x-rays are typically obtained before and after reduction to rule out fractures. X-rays confirm the dislocation and check for associated injuries.
What is the relationship between anterior shoulder dislocation and axillary nerve injury?
Approximately 5% of anterior shoulder dislocations are associated with axillary nerve dysfunction due to the nerve’s location below the humeral head and around the humerus neck. This injury leads to a loss of sensation over the lateral shoulder. Long-term damage is rare, and patients usually fully recover.
What is a supracondylar fracture, and what commonly causes it?
A supracondylar fracture is a fracture of the distal humerus just above the elbow. It accounts for 60% of elbow fractures and typically occurs in children aged 2 to 7 following a fall on an outstretched arm.
How does a supracondylar fracture lead to neurovascular complications, and what are the signs of brachial artery injury?
The brachial artery and median nerve cross the elbow joint together, making them vulnerable in supracondylar fractures, especially with posterolateral displacement of the humerus. Brachial artery damage can cause decreased or absent radial pulses and/or compartment syndrome due to forearm swelling.
What are the effects of median nerve damage in a supracondylar fracture?
Median nerve injury from a supracondylar fracture leads to decreased sensation and weakness in the wrist flexors, forearm pronators, finger flexors, and thenar muscles.
What is medial epicondylitis, and what typically causes it?
Medial epicondylitis, or golfer’s elbow, is a form of chronic tendinosis characterized by tendon pain and swelling. It results from repetitive movements, often associated with activities like golfing. Poor mechanics and improper equipment may contribute to this condition.
Lateral epicondylitis is a form of chronic tendinosis associated with overuse. Also known as tennis elbow, patients present with
Pain of the lateral epicondyle and proximal wrist extensors that is worse with resisted wrist extension.
What is a proximal humerus fracture, and who is most at risk?
A proximal humerus fracture is the third most common fracture in older adults, following hip and distal radius fractures. It primarily affects individuals over 60 years, particularly females and those with low bone density.
How does a proximal humerus fracture typically present?
Patients present with bony pain, swelling, and ecchymosis on the affected side. They often hold the arm adducted against their side. Obvious deformities may appear if there is an associated shoulder dislocation.
What complications are associated with proximal humerus fractures?
Proximal humerus fractures carry a high risk of complications due to their proximity to the axillary artery, axillary nerve, and brachial plexus. Complications include avascular necrosis, axillary nerve damage (causing deltoid weakness and loss of sensation to the lateral shoulder), and suprascapular nerve damage (affecting supraspinatus and infraspinatus muscle function).
Proximal humerus fractures carry a high risk of complications due to their proximity to the axillary artery, axillary nerve, and brachial plexus. Complications include
Avascular necrosis, axillary nerve damage (causing deltoid weakness and loss of sensation to the lateral shoulder), and suprascapular nerve damage (affecting supraspinatus and infraspinatus muscle function)
Clavicle fractures usually result from shoulder trauma and are more common in children and young adults. Patients complain of localized pain that is exacerbated by shoulder movement and frequently have a bulge/hematoma at the fracture site. The most common complication is
Nonunion (fracture that does not heal, causing long-term symptoms), although brachial plexus injuries may also occur.
Most commonly in children after falls on an outstretched arm. Medial epicondylar fractures account for 10%of elbow fractures and are frequently accompanied by an elbow dislocation and ulnar nerve damage. Lateral epicondylar fractures are much less common and are not associated with nerve damage. Patients present with elbow pain, swelling, bony tenderness, and decreased range of motion.
Epicondylar fractures of the humerus occur
What causes thoracic outlet syndrome in cases involving a cervical rib, and what structures are affected?
Thoracic outlet syndrome can be caused by a cervical rib, an extra rib arising from the 7th cervical vertebra. The cervical rib compresses the brachial plexus trunks (C8-T1) along with the subclavian artery and vein within the scalene triangle, leading to neurovascular symptoms.
What are the typical symptoms of thoracic outlet syndrome, and what worsens them?
Patients present with pain, tingling, and weakness in the wrist and hand flexor muscles. Symptoms worsen with arm elevation. While motor symptoms are more common, vascular symptoms may also develop, including arm swelling, hand ischemia (pallor, cool temperature), and weak radial pulses.
Besides a cervical rib, what other factors can cause thoracic outlet syndrome, and how is it diagnosed?
Other causes of thoracic outlet syndrome include muscular anomalies and traumatic injuries. Diagnosis is confirmed by imaging, typically CT or MRI.
What treatment options are available for thoracic outlet syndrome caused by a cervical rib?
Treatment options include physical therapy to relieve symptoms and surgical resection of the cervical rib to alleviate compression.
r): Carpal tunnel syndrome is caused by the entrapment and compression of the median nerve in the carpal tunnel. Patients initially present with numbness, tingling, and loss of sensation of the first three digits and the radial half of the fourth digit. When severe, carpal tunnel syndrome may cause
Impaired flexion and extension of the lateral finger and thumb.
What is shoulder impingement syndrome, and which structures are compressed?
Shoulder impingement syndrome is a condition where the rotator cuff muscles, biceps tendon, and subacromial bursa are compressed between the humeral head and the acromion. This compression causes a spectrum of symptoms related to shoulder pain and dysfunction.
What are the common symptoms of shoulder impingement syndrome?
Patients with shoulder impingement syndrome typically present with shoulder pain that worsens with overhead activities or when lying on the affected shoulder.
What causes winging of the scapula, and which structures are involved?
Winging of the scapula is caused by paralysis of the serratus anterior muscle due to damage to the long thoracic nerve. This nerve arises from the fifth, sixth, and seventh cervical roots and innervates the serratus anterior, which stabilizes the scapula.
What are the clinical symptoms of winging of the scapula?
Patients present with shoulder pain radiating to the arm and scapula, shoulder weakness, and prominent scapular “winging” that becomes most obvious when they extend their arms against a wall.
What can cause damage to the long thoracic nerve, and how is it treated?
Injury to the long thoracic nerve can result from anterior shoulder trauma, surgical procedures, or compression (e.g., prolonged backpack use). Most cases from repetitive motion or compression resolve in 6 to 24 months with physical therapy and rest as the primary treatment.
What is radial neuropathy at the spiral groove, and what causes it?
Radial neuropathy at the spiral groove, also known as “Saturday night palsy,” is caused by acute radial nerve compression. The radial nerve originates from the posterior cord of the brachial plexus and innervates the triceps and forearm extensor muscles. Common causes include midshaft humerus fractures, prolonged crutch use, and sleeping with arms over a chair.
How does the clinical presentation differ between axillary and spiral groove injuries to the radial nerve?
In axillary injuries, patients present with triceps weakness, difficulty with wrist and finger extension, and decreased sensation in the posterior forearm and dorsal hand. In spiral groove injuries, symptoms include forearm extensor weakness and decreased sensation in the dorsal hand.
What is the typical treatment and prognosis for radial neuropathy caused by acute compression?
Most cases of acute radial neuropathy resolve completely with conservative treatment, including rest, wrist splinting, and physical therapy. Full recovery is expected in most patients.
What causes Erb’s palsy, and what is the major risk factor?
Erb’s palsy is an upper brachial plexus injury affecting the C5-C6 trunk, commonly caused by birth trauma. The major risk factor is shoulder dystocia, where the baby’s shoulder gets caught against the mother’s pubic bone during vaginal delivery. This injury leads to stretching of the C5-C6 trunk.
How does Erb’s palsy present in infants?
Infants with Erb’s palsy present with decreased movement in the affected arm, which is typically held adducted and internally rotated. This positioning results from weakness in the deltoid, infraspinatus (C5), and biceps (C6) muscles.
What causes musculocutaneous neuropathy, and what nerve is affected?
Musculocutaneous neuropathy is often caused by abnormal arm positioning during surgery. The musculocutaneous nerve originates from the lateral cord of the brachial plexus and primarily innervates the biceps muscle.
What are the clinical symptoms of musculocutaneous neuropathy?
Patients with musculocutaneous nerve damage present with weakness in elbow flexion and decreased sensation in the lateral forearm.
What are common associations with musculocutaneous neuropathy?
Musculocutaneous neuropathy can be associated with trauma, shoulder dislocation, and strenuous exercise, especially those activities involving the biceps muscle.
What is the common cause of a scaphoid fracture, and how prevalent are they?
A scaphoid fracture is commonly caused by falling on an outstretched hand. It is the most common carpal fracture and accounts for approximately 10% of all hand fractures.
What symptoms do patients with a scaphoid fracture typically present with?
Patients with a scaphoid fracture typically present with pain in the anatomic snuffbox (located proximal to the base of the thumb) and decreased grip strength.
What is a key consideration in diagnosing scaphoid fractures based on x-ray results?
Most scaphoid fractures occur in the central portion (waist) of the scaphoid, and 20% to 54% of fractures may initially show a negative x-ray. Due to the high false-negative rates, pain in the anatomic snuffbox should be treated as a scaphoid fracture, regardless of initial x-ray findings.
What causes ulnar neuropathy, and what is a common name for it?
Ulnar neuropathy can be caused by direct pressure from the handlebars of a bicycle, commonly referred to as handlebar palsy. The ulnar nerve and artery pass through Guyon’s canal into the wrist and are susceptible to damage from chronic compression, hamate fractures, and direct trauma.
What is the origin of the ulnar nerve, and what muscles does it innervate?
The ulnar nerve originates from the medial cord of the brachial plexus and innervates the flexor muscles of the forearm, as well as the fourth and fifth fingers.
What are the symptoms of ulnar neuropathy at the elbow?
Patients with ulnar neuropathy at the elbow present with elbow pain, decreased sensation in the ulnar half of the fourth digit and the fifth digit, and decreased grip strength.
How do symptoms of ulnar neuropathy differ at the wrist compared to the elbow?
Patients with ulnar neuropathy at the wrist present with decreased sensation in the ulnar half of the fourth digit and the fifth digit, as well as weakness in the abduction and adduction of the fourth and fifth digits.
What is the typical treatment for ulnar neuropathy, and when is surgery indicated?
Conservative treatment for ulnar neuropathy is often unsuccessful, leading many patients to require surgical decompression of Guyon’s canal when conservative measures fail.
What is carpal tunnel syndrome, and what are its symptoms?
Carpal tunnel syndrome is caused by compression of the median nerve in the carpal tunnel, leading to sensory symptoms including pain, numbness, and tingling in the first, second, and third digits and the radial half of the fourth digit. Later symptoms may include wrist pain and weakness with thumb abduction and opposition.
What is the anatomy of the median nerve, what are the risk factors for carpal tunnel syndrome, and how is it related to other conditions?
The median nerve originates from the lateral and medial cords of the brachial plexus, innervating the wrist flexor/pronators, finger flexors, and thenar muscles. Risk factors for carpal tunnel syndrome include obesity, pregnancy (due to wrist edema), female gender, and chronic diseases such as rheumatoid arthritis, type 1 diabetes (Hemoglobin H1c), and hypothyroidism. In patients with acromegaly, characterized by excess growth hormone, there is an increased incidence of bilateral carpal tunnel syndrome.
What causes carpal tunnel syndrome in patients with chronic renal failure, and what are the associated symptoms?
In patients with chronic renal failure, carpal tunnel syndrome is caused by β2-microglobulin amyloid deposits in the carpal tunnel, which compress the median nerve. Normally cleared by glomerular filtration, β2-microglobulin accumulates in plasma and tissues (bones, joints, and tendons) in renal failure, forming amyloid deposits that lead to symptoms. The median nerve innervates the wrist flexor/pronators, finger flexors, and thenar muscles. Patients initially experience sensory symptoms like pain, numbness, and tingling in the first, second, and third digits, as well as the radial half of the fourth digit. Later, symptoms progress to wrist pain and weakness in thumb abduction and opposition, often worse on the side with the dialysis catheter and can be bilateral. Additionally, there may be shoulder pain due to accumulation in the rotator cuff muscles.
What is a torus (buckle) fracture, and what are its characteristics and presentation in children?
A torus (buckle) fracture of the radius is caused by axial force trauma, such as falling onto an outstretched arm. These fractures are most common in young children and typically occur in the distal metaphysis, where the bone is more porous. Torus fractures result from buckling of the cortex due to bony failure and are most often seen in the radius. Patients typically present with tenderness over the wrist, but there is usually no visible swelling or deformity, and they maintain a normal range of motion.
What is Klumpke’s palsy, its cause, presentation, and associated muscle impairments?
Klumpke’s palsy is a lower brachial plexus injury affecting the C8-T1 trunk, typically caused by excessive abduction of the arm, such as attempting to catch a tree branch while falling. Patients with this injury exhibit a “clawed hand” appearance, characterized by hyperextension of the metacarpophalangeal (MCP) joints and flexion of the interphalangeal (IP) joints. This condition leads to impaired function of the intrinsic hand muscles, including the thenar, hypothenar, interosseous, and lumbrical muscles.
What causes proximal median neuropathy, and what are its clinical presentations and associated conditions?
Proximal median neuropathy is caused by a laceration above the elbow affecting the median nerve, which originates from the lateral and medial cords of the brachial plexus. This nerve innervates the wrist flexor and pronator muscles, finger flexors, and thenar muscles. Proximal median neuropathy presents with impaired flexion of the first, second, and third digits, a condition known as “Pope’s blessing” or the “Hand of Benediction.” Patients may also experience impaired thumb abduction and opposition, leading to thenar atrophy, termed “ape hand.” Unlike other neuropathies, median neuropathy is not associated with impaired sensation or ulnar deviation, as the flexor muscles of the wrist remain intact. Damage can occur due to supracondylar fractures, carpal tunnel syndrome, or direct trauma to the wrist.
What is the clinical presentation and pathophysiology of median neuropathy caused by a supracondylar fracture in children?
A supracondylar fracture is the most common pediatric elbow fracture, typically caused by a fall onto an outstretched arm. It can damage both the brachial artery and median nerve, which travel across the elbow. The median nerve, arising from the lateral and medial cords of the brachial plexus, innervates wrist flexors, pronators, finger flexors, and thenar muscles. Injury to the median nerve at the elbow results in:
- Loss of forearm flexion and pronation
- Decreased sensation in the wrist flexors, finger flexors, and thenar muscles
- Clinical signs: supinated forearm, ulnar deviation of the wrist, and impaired wrist flexion.
- This injury is associated with pain, swelling, and decreased range of motion at the elbow.
Recurrent Branch of Median Nerve Injury
Definition: Damage to the recurrent branch of the median nerve, often caused by a superficial hand laceration.
Recurrent Branch of Median Nerve Injury
Pathophysiology: The recurrent branch of the median nerve provides motor innervation to the thenar muscles, including the flexor pollicis brevis, abductor pollicis brevis, and opponens pollicis. Injury to this nerve affects thumb movements, particularly abduction and opposition, as the thenar muscles are responsible for these functions.
Recurrent Branch of Median Nerve Injury
Clinical Presentation:
Impaired thumb movements, specifically loss of abduction and opposition (immobilized thumb).
Normal sensation is preserved in the hand, as sensory branches are unaffected.
Patients often report difficulty with tasks that require thumb mobility, but there is no sensory loss in the affected hand.
Genitofemoral Neuropathy Post-Abdominal Surgery
Definition: Genitofemoral neuropathy is a complication of open abdominal surgery, particularly when the genitofemoral nerve is damaged during dissection of the external iliac lymph nodes or mobilization of the iliac vessels.
Genitofemoral Neuropathy Post-Abdominal Surgery
Pathophysiology: The genitofemoral nerve originates from the L1-L2 trunks of the lumbar plexus. It innervates the cremasteric muscle and provides sensory input to the anterior thigh and scrotum (or labia in females). During abdominal surgery, the nerve is at risk of compression or transection, especially by retractor blades.
Genitofemoral Neuropathy Post-Abdominal Surgery
Clinical Presentation:
- Absent Cremasteric Reflex: Normally, stroking the inner thigh causes the scrotum to rise, but this reflex is absent in genitofemoral neuropathy.
- Decreased Sensation: Affected areas include the anterior thigh and the scrotum in males (or labia in females).
Lateral Femoral Cutaneous Neuropathy (Meralgia Paresthetica) in Pregnancy. Definition:
Lateral femoral cutaneous neuropathy, or meralgia paresthetica, is a compression neuropathy of the lateral femoral cutaneous nerve (L2-L3), often associated with pregnancy, obesity, or tight clothing.
Lateral Femoral Cutaneous Neuropathy (Meralgia Paresthetica) in Pregnancy. Pathophysiology:
The lateral femoral cutaneous nerve is a sensory nerve from the lumbar plexus that supplies the anterior and lateral thigh. It passes beneath the inguinal ligament, where it is prone to compression due to pregnancy, tight clothing, tool belts (e.g., in construction workers), or abdominal fat in obesity.
Lateral Femoral Cutaneous Neuropathy (Meralgia Paresthetica) in Pregnancy. Clinical Presentation:
Sensory Symptoms: Pain, numbness, and tingling in the anterior and lateral thigh.
Sensory Loss: Possible loss of sensation on the lateral thigh.
Management:
Lateral Femoral Cutaneous Neuropathy (Meralgia Paresthetica) in Pregnancy. Conservative:
Usually self-limited, symptoms often improve with loose clothing, weight loss, or after pregnancy.
Pudendal Neuropathy in Vaginal Childbirth. Definition:
Pudendal neuropathy is a nerve injury commonly associated with stretching of the pudendal nerve during vaginal childbirth.
Pudendal Neuropathy in Vaginal Childbirth. Pathophysiology:
The pudendal nerve originates from S2-S4 of the sacral plexus.
It provides motor innervation to the external urethral and anal sphincters and perineal muscles and sensory innervation to the perineum.
Pudendal Neuropathy in Vaginal Childbirth. Clinical Presentation:
Sensory Impairment: Reduced sensation in the perineal area.
Incontinence: Possible fecal and urinary incontinence due to sphincter dysfunction.
Pain: Dyspareunia (painful intercourse) and perineal pain that worsens with prolonged sitting.
Pudendal Neuropathy in Vaginal Childbirth. Management:
Symptom Relief: Pain management and physical therapy are often recommended.
Common Peroneal Neuropathy and Compression Injuries
Definition: Common peroneal neuropathy occurs when the common peroneal nerve is compressed, often due to a tight lower leg cast. Other risk factors include prolonged bed rest, proximal fibular neck fractures, and knee dislocations.
Pathophysiology: The common peroneal nerve branches from the sciatic nerve and supplies the short head of the biceps femoris (hamstring muscle) and muscles of the lateral and anterior lower leg.
Clinical Presentation:
Motor Deficits: Difficulty with dorsiflexion of the foot (leading to foot drop) and toe extension.
Sensory Deficits: Decreased sensation over the lateral shin and dorsum of the foot.
Management:
Removal of Compression: Releasing or loosening casts or other sources of compression.
Physical Therapy: Strengthening exercises to help restore movement and function.
Femoral Neuropathy Due to Inguinal Lymph Node Dissection
Definition: Femoral neuropathy occurs from damage to the femoral nerve (L2-L4) and may result from procedures like inguinal lymph node dissection.
Pathophysiology:
The femoral nerve originates from the L2-L4 nerve roots of the lumbar plexus and supplies the anterior thigh muscles, including hip flexors and knee extensors.
Femoral Neuropathy Due to Inguinal Lymph Node Dissection
Clinical Presentation:
Motor Deficits: Difficulty with thigh flexion and knee extension.
Sensory Deficits: Pain or tingling in the anterior thigh and knee.
Reflex Changes: Absent patellar reflex.
Management:
Physical Therapy: Exercises to improve mobility and strengthen weakened muscles.
Pain Management: Medications or modalities to address sensory symptoms.
S1 Nerve Root Compression from Spinal Stenosis
Definition: S1 nerve root compression occurs as a result of spinal stenosis, most common in individuals over 60. A key risk factor is spondylosis (spinal degenerative arthritis).
Pathophysiology: Spinal stenosis involves narrowing of the spinal canal, leading to nerve root compression.
Compression Mechanism: Exacerbated in upright posture due to reduced intralaminar space.
S1 Compression: Associated with weakness in plantar flexion and diminished ankle reflexes.
S1 Nerve Root Compression from Spinal Stenosis
Imaging Findings:
MRI reveals osteophyte formation and ligamentum flavum hypertrophy.
Osteophytes: Bone spurs from chronic arthritis.
Ligamentum flavum hypertrophy: Thickening due to inflammatory cell accumulation in chronic osteoarthritis.
Clinical Presentation:
- Leg Pain: Worsens with standing and walking; relieved by sitting or lying down.
Management:
- Physical Therapy and Pain Relief: Initial management to address symptoms.
- Surgical Intervention: Considered in severe cases for decompression.
L5 Nerve Root Radiculopathy
L5 radiculopathy is the most common radiculopathy affecting the lumbosacral spine, often caused by herniated discs. Other causes include spondylolisthesis (vertebral displacement) and osteoarthritis.
Pathophysiology: L5 Nerve Root Radiculopathy
Herniated Disc: Compresses the L5 nerve root, leading to pain and motor dysfunction.
Other Causes: Spondylolisthesis and osteoarthritis may also lead to nerve root compression.
Clinical Presentation: L5 Nerve Root Radiculopathy
Pain: Lower back pain radiating to the lateral leg and foot.
Motor Impairments: Difficulty with foot dorsiflexion and toe extension.
Sensory Loss: Decreased sensation along the lateral shin and dorsal surface of the foot
Key Differentiation: L5 Nerve Root Radiculopathy vs. Common Peroneal Neuropathy
Vs. Common Peroneal Neuropathy: L5 radiculopathy includes radiating lower back pain, while common peroneal neuropathy typically does not.
Management: L5 Nerve Root Radiculopathy
Conservative Treatment: Rest, physical therapy, pain management.
Surgical Options: Considered in severe or refractory cases, often involving decompression.
Definition: S1 Nerve Root Radiculopathy
S1 nerve root radiculopathy is the second most common radiculopathy affecting the lumbosacral spine. The most frequent cause is a herniated disc.
Clinical Presentation: S1 Nerve Root Radiculopathy
Pain: Lower back pain radiating to the back of the leg.
Motor Deficits: Impaired plantar flexion (difficulty standing on toes) and knee flexion.
Reflex Changes: Absent or reduced ankle reflex.
Sensory Loss: Decreased sensation to the posterior calf and lateral foot.
Electromyography (EMG) Findings: S1 Nerve Root Radiculopathy
EMG studies show impairment in muscles innervated by the S1 nerve root, including the gluteus maximus and quadriceps.
Definition: L3 Nerve Root Radiculopathy
L3 nerve root radiculopathy is most commonly caused by spinal stenosis or a herniated disc. The L2, L3, and L4 nerve roots overlap significantly and are usually considered as a group that supplies the femoral nerve.
Clinical Presentation: L3 Nerve Root Radiculopathy
Pain: Lower back pain radiating to the anterior thigh and knee.
Sensory Loss: Loss of sensation to the anterior thigh.
Motor Deficits: Impaired hip flexion and knee extension.
Reflex Changes: Reduced or absent patellar reflex.
Electromyography (EMG) Findings: L3 Nerve Root Radiculopathy
EMG studies show impairment in the muscles innervated by the femoral nerve, including the quadriceps and iliopsoas muscles.
Superior Gluteal Nerve Injury (Trendelenburg Gait)
Definition: Superior Gluteal Nerve Injury
Damage to the superior gluteal nerve can occur as a complication of hip surgery (hip arthroplasty), occurring in up to 3% of cases. This injury can result from hematoma, direct trauma, or ischemia. While injury to the sciatic nerve is most common, superior gluteal nerve injury may also occur.
Anatomy: Superior Gluteal Nerve
The superior gluteal nerve arises from the L4-S1 trunks of the sacral plexus and innervates the gluteus minimus and gluteus medius muscles.
Clinical Presentation: Superior Gluteal Neuropathy
Motor Deficit: Impaired hip abduction.
Gait Abnormality: Classic Trendelenburg gait due to weakness of the gluteus medius muscle.
When stepping on the affected side, the pelvis tilts toward the unaffected side.
Patients have difficulty maintaining balance on the affected leg, with the pelvis tilting to the unaffected side to reduce load and pain.
The superior gluteal nerve is purely motor, so sensory loss is not a feature of this injury.
What muscle is involved in pain and weakness with hip extension due to a strain in this scenario?
Gluteus maximus.
Which nerve innervates the gluteus maximus muscle?
L5-S2 trunks.
What role does the gluteus maximus play in the hip movement?
It plays a major role in hip extension and external rotation.
