Neck of femur fracture differential diagnosis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Rohan A. Bhimani, M.B.B.S., D.N.B., M.Ch.[2]

Overview

Neck of femur fracture must be differentiated from other causes of acute hip pain, restriction of movements, and deformity such as intertorchanteric hip fracture, osteoarthritis, avascular necrosis, septic arthritis, trochanteric bursitis, slipped capital femoral epiphysis and acute synovitis.

Differentiating Neck of Femur Fracture from other Diseases

• Neck of femur fracture must be differentiated from other causes of acute hip pain, restriction of movements, and deformity such as intertorchanteric hip fracture, osteoarthritis, avascular necrosis, septic arthritis, trochanteric bursitis, slipped capital femoral epiphysis and acute synovitis.

Diseases	Clinical manifestations						Para-clinical findings			Gold standard	Additional findings
	Symptoms			Physical examination
							Imaging
	Pain	Restriction of Movements	Deformity	Tenderness	Active Straight Leg Raising	Distal Pulses	X-ray	CT scan	MRI
Neck of Femur Fracture	+	+	Shortening Externally rotated leg	+	-	+	Fracture fragment displacement Fracture fragment angulation	Accurate diagnosis of fracture pattern ans aids in classification. Useful for preoperative surgical planning for patients with complex, multifragmentary fractures.	Useful in diagnosing occult fractures.	X-ray	Bone scan shows increased uptake of radioactivity in region of fracture.
Intertrochanteric Hip Fracture	+	+	Shortening Externally rotated leg	+	-	+	Fracture fragment displacement Fracture fragment angulation	Accurate diagnosis of fracture pattern ans aids in classification. Useful for preoperative surgical planning for patients with complex, multifragmentary fractures.	Useful in diagnosing occult fractures.	X-ray	Trochanteric Thump test is positive.
Subtrochanteric Femur Fracture	+	+	Thigh is deformed	+	-	+	Fracture fragment displacement Fracture fragment angulation	Accurate diagnosis of fracture pattern ans aids in classification. Useful for preoperative surgical planning for patients with complex, multifragmentary fractures.	Useful in diagnosing occult fractures.	X-ray
Acetabular Fracture	+	+	-	+	+/-	+/-	Fracture fragment displacement Fracture fragment angulation	Accurate diagnosis of fracture pattern ans aids in classification. Useful for preoperative surgical planning for patients with complex, multifragmentary fractures.	Useful in diagnosing occult fractures.	CT	It is a medical emergency as there is a large amount of blood loss. Per urethral blood may be present. Swelling may be present in the scrotal or perineal area.
Pubic Rami Fracture	+	+	-	+	+/-	+	Fracture fragment displacement	Accurate diagnosis of fracture pattern ans aids in classification.	Useful in diagnosing occult fractures.	MRI
Femoral Head Fracture	+	+	May be associated with flexion, adduction and internal rotation deformity.	+	-	+	Fracture fragment displacement Fracture fragment angulation	Accurate diagnosis of fracture pattern ans aids in classification. Useful for preoperative surgical planning for patients with complex, multifragmentary fractures.	Useful in diagnosing occult fractures.	CT	It may be associated with dislocation. It may be associated with foot drop due to compression of the sciatic nerve.
Osteoarthritis	+	+	Flexion and external rotation deformity	+	+	+	Joint space narrowing, osteophytes, subchondral sclerosis and subchondral cysts.	Normal	MRI shows cartilage defects and bone marrow lesions.	X-ray	Hip locking, instability and catching sensation.
Trochanteric Bursitis	+	+/-	-	+	+	+	Normal	Normal	Increased signal in bursa due to inflammation on T2 images.	MRI	Lateral hip pain near the greater trochanter and patients points to greater trochanter. Patient may have trendelenburg gait.
Septic Arthritis	+	+	+/-	+	+	+	Normal	Normal	Joint fullness and capsular dilation. It also demonstrates damage to the articular cartilage.	MRI	Fever and chills may be present. Hip aspiration may reveal frank pus or a turbid fluid. Culture of the infecting organisms in the fluid is confirmatory. Leukocytosis.
Avascular Necrosis of Head of Femur (Osteonecrosis)	+	+	Adduction deformity	+	+	+	Early x-ray findings include lucency of the femoral head and subchondral sclerosis. In advanced stage, subchondral collapse (ie, crescent sign), femoral head flattening and joint space narrowing is seen.	CT shows subchondral collapse.	MRI shows bone marrow edema and rail track sign.	MRI	Patient may have trendelenburg gait. Passive internal and external rotation of the extended leg may elicit pain due to synovitis. Ficart and Arlet as well as Steinberg classification of avascular necrosis is done radiologically.
Diseases	Pain	Restriction of Movements	Deformity	Tenderness	Acitve Straight Leg Raising	Distal Pulses	X-ray	CT scan	MRI	Gold standard	Additional findings
Femoroacetabular Impingement (FAI)	+	+	External rotation deformity	+	+	+	Pistol grip deformity: It is asphericity and contour of femoral head and neck indicating Cam impingement. Crossover sign: It is a sign of acetabular retroversion seen in Pincer impingement.	Confirms X-ray findings.	Evaluates articular cartilage damage, and labral degeneration and tears.	MRI	Anterior impingement test: On flexion, adduction, internal rotation of the hip produces pain.
Idiopathic Transient Osteoporosis of the Hip (ITOH)	+	+	-	+	+	+	Subchondral cortical loss. Diffuse osteopenia of femoral head and neck. Joint effusion Joint space is always preserved	Confirms X-ray findings.	Marrow edema of femoral head and neck	MRI	Commonly seen among women in 3rd trimester of pregnancy and middle aged men. Bone scan shows increased uptake in the femoral head.
Transient Synovitis of the Hip	+	+	Flexion, abduction and external rotation deformity	+	+	+	Normal	Normal	Joint space effusion	USG	History of recent upper respiratory tract infection or trauma to the hip. Fever may be present. Involuntary muscle guarding on log rolling of the leg. Ultrasound shows intracapsular effusion and synovial membrane thickening.
Slipped Capital Femoral Epiphysis (SCFE)	+	+	Adduction and external rotation defromity	+	+	+	Klein's line: A line drawn along superior border femoral neck will intersect less of the femoral head or not at all in a child with SCFE. Epiphysiolysis Blanch sign of Steel: Proximal femoral metaphyseal blurring	Confirms X-ray findings.	Growth plate widening Edema in metaphysis	MRI	Antalgic gait Drehmann sign: External rotation during passive flexion of the hip. Externally rotated foot progression angle.
Adult Dysplasia of the Hip	+	Increased internal rotation due to increased femoral anteversion	External rotation deformity may be present in the late stages.	+	+	+	Decreased femoral head sphericity. Crossover sign results from increased retroversion. Acetabular protrusio: Decreased lateral center-edge angle < 20°. Increased Tonnis angle ( angle between the horizontal line and line along the superior acetabulum) > 10°. Decreased head-neck offset ratio. Increased femoral neck-shaft angle. Decreased vertical center anterior margin angle.	Structural abnormalities of the femoral head and neck is seen.	-	X-Ray	Positive anterior impingement test may be seen.
Diseases	Pain	Restriction of Movements	Deformity	Tenderness	Acitve Straight Leg Raising	Distal Pulses	X-ray	CT scan	MRI	Gold standard	Additional findings
Iliospoas Tendinitis	+	-	Flexion and external rotation deformity	+	+	+	Normal	Normal	T2 images show an increased signal intensity associated with swelling and inflammation.	MRI	Anterior pelvic tilt due to tightening of the iliopsoas muscle. Ludloff sign: Patient asked to sit with knees extended and subsequent elevation of the heel on the affected side causes pain. Ultrasound demonstrates thickened band and fluid in the iliospoas bursa.
Hip Pointer (Contusion of the Iliac Crest)	+	+/-	Adduction and internal rotation deformity may be present.	+	+	+	Normal	Normal	Swelling of the surrounding soft tissues may be seen.	-	Contusion or swelling may be present.
Snapping Hip Syndrome (Coxa Saltans)	+/-	-	-	+/-	+	+	Normal	Normal	May show inflamed bursa.	Ultrasound	External snapping hip: Palpate the greater trochanter as hip is actively flexed and applying pressure will likely stop snapping if external band present. Ober's Test: Limited hip adduction when hip held in extension indicate tightness of tensor fascia lata. Internal snapping hip: Snapping is reproduced by passively moving hip from a flexed and externally rotated position to an extended and internally rotated position. Ultrasound shows the snapping band in either internal or external snapping.
Osteitis Pubis	+	-	-	+	+	+	Osteolytic pubis with bony erosions	CT confirms x-ray findings	Bone marrow edema is seen.	MRI	Bone scan shows increased activity in area of pubic symphysis.
Referred Pain from Lumbosacral Plexus	+	-	-	+	+	+	Narrowing of the disc space	Normal	Compression of the nerve root and disc bulge Osteophytes may be seen.	MRI	Pain on passive straight leg raising.