Hip joint is a ball and socket joint formed by femur and socket of acetabulum of pelvic bone.1 Fracture is a partial or complete break or separation of the bone with intact or loss of blood supply. Hip joint fracture includes fracture of femur as well as acetabulum of pelvic bone. In United State 300,000 cases of hip fracture are treated every year.
Classification of Hip Joint Fracture Causing Hip Pain
Fracture of Femur In Hip Joint Fracture:
- Sub-Capital Neck Fracture
- Trans-Cervical Neck Fracture
- Inter-Trochanteric Fracture
- Sub-Trochanteric Fracture
- Fracture of Greater Trochanter
- Fracture of Lesser Trochanter
Fracture of Pelvis In Hip Joint Fracture-
- Acetabular Fracture– Fracture of Acetabular Rim
- Fracture of Socket–
- Anterior Wall Fracture
- Posterior Wall Fracture
Types of Hip Joint Fracture
Hairline or Stress Hip Joint Fracture– Hairline hip joint fracture is also known as stress fracture.2 Stress or hairline fracture is a non-displaced fracture and maintains intact anatomical structure. Hairline fracture does not cross entire thickness of the bone. Hairline hip joint fracture is a partial (superficial) crack without any separation of bones. Stress or hairline hip joint fracture of the neck of femur may cause by repetitive motion of legs or overuse of extremity. Hairline fracture is seen in femur, acetabulum and adjacent pelvic bone. Blood supply to bones adjacent to fracture is intact and avascular necrosis is rare.
Non-Displaced Hip Joint Fracture (Transverse Fracture)– In a non displaced fracture, adjacent bone maintains anatomical position without separation.3 Fracture crosses entire thickness of the bone without separation of adjacent ends of the fractured bones. Such fracture is also known as transverse fracture. Non–displace fracture is observed over neck of femur, upper 1/3rd shaft of femur and acetabulum of pelvis. Non-displaced fracture occurs following fall in older patients. Non-displaced fracture is also observed following severe hip joint impact during auto accident and in patients suffering with osteoporosis. Normal blood supply of the fracture site prevents avascular necrosis.
Partial Displaced Hip Joint Fracture– In a partial displaced fracture, the ends of adjacent fractured bone maintains contacts along the fractured surface at the periphery or edges of the fracture bone. Partial displace fracture causes deformity of the leg at rest. Deformity is observed as result of mal-alignment and angulation between proximal and distal end of the fractured femur. Blood supply to adjacent fractured bone is interrupted and may result in avascular necrosis if not treated within 6 to 8 hours following injury.
Complete Displaced Hip Joint Fracture– Proximal and distal ends of the fractured bones are completely separated and do not maintain any contact. Complete displaced fracture is seen over neck and shaft of the femur. Blood supply to adjacent fracture bones are interrupted resulting in avascular necrosis.
Risk Factors Associated With Hip Joint Fracture-
- 90% of the hip fractures are seen in patients over age 60
- Number of hip fractures doubles for each decade after age 50.
- More common in females than males.
Osteoporosis– Osteoporosis is a progressive skeletal disease which results in fragile and weak bone. Bony structures become weak secondary to decreased mass and density of skeletal of the bone. Osteoporosis is often observed in female following menopause as a result of decreased estrogen hormone secretion to subclinical level. Low estrogen level stimulates abnormal metabolism resulting in reduced bone minerals and development of symptoms of osteoporosis. Dietary calcium and vitamin D deficiency causes osteoporosis in younger patients.
Alcohol– Excessive alcohol consumption is associated with osteoporosis and accidental fall in young patients.
Caffeine– Excessive caffeine consumption causes osteoporosis in few patients.
Physical Inactivity– Lack of physical activities changes metabolism of bones and decreases mineral concentration of bone. Fall or injury in such individual often results in fracture of hip joint.
Loss of Body Weight– Cachexia or loss of body weight causes calcium deficiency and demineralization of bone resulting in weak bones. Fall or injury may cause fracture of hip joint.
Cigarette Smoking– Chronic smoking causes hypoxia of peripheral tissue and bone. In addition, smoking also interferes with calcium metabolism resulting in less calcium in skeletal system. Fracture of hip joint in chronic smoker takes long time to heal because of hypoxia or low oxygen level at the peripheral tissue and bone.
Unsteady Gait– Patient suffering with unsteady gait has a tendency to fall and fracture normal bone. Older patient suffering with weak bone and osteoporosis end up with fractured hip bone following fall secondary to unsteady gait.
Vision Deficiency– Vision deficiency in older patients causes fall and fracture of hip joint.
Dementia– Patient with dementia are unaware of surrounding and often have a tendency to fall, which results in hip joint fracture.
Causes of Hip Joint Fracture-
Injuries Causing Hip Joint Fracture-
- Auto Accident– Auto accident often causes direct impact at hip joint in sitting position resulting in posterior dislocation and fracture of hip joint.
- Work Accident– Work accident caused by fall or direct impact of heavy object to hip joint causes hip pain or hip joint fracture.
- Fall– Slip and fall over slippery surface or ice results in hip pain or hip joint fracture in patients suffering with osteoporosis. Similarly slip and fall causes fracture of femur when individual is involved in ice sports like ice hockey, skiing and snow mobile driving.
- Cycling– Repeated movement of leg with prolonged cycling may cause hip pain and hairline hip joint fracture.
Diseases Resulting In Hip Joint Fracture
- Osteoporosis– Seen in women following menopause because of lack of estrogen and results in weak bone as a result of lower bone density.
- Endocrinal Disease– Hyperthyroidism causes overactive thyroid gland and increases secretion of thyroid hormone. Thyroid hormone affects calcium metabolism and produces weak bone.
- Intestinal Disorders– Diseases causing malabsorption results in decreased absorption of vitamin D and calcium. Lower level of Vitamin D and calcium causes structural weakness in bone. Injury or fall results in fracture of hip joint.
- Nutritional Problems– Hip pain is caused by lack of calcium and vitamin D resulting in weak bone and osteoporosis. Fall or injury often results in Hip joint fracture.
- Eating Disorder– Anorexia nervosa and bulimia results in low calcium and vitamin D in diet. In Patients with prolonged eating disorder, a hip injury due to fall may result in hip joint fracture.
- Homocysteine– Very high plasma homocysteine causes homocystinuria, which is a rare autosomal recessive disease. Homocystinuria is also associated with osteoporosis and hip pain.
- Osteomalacia– Osteomalacia is caused by inadequate dietary amount of phosphorous and calcium. Abnormal bone metabolism is observed in patients suffering with Osteomalacia, which follows bone demineralization and hip joint fracture.
- Paget’s Disease– Paget’s is caused by abnormal bone metabolism resulting in excessive breakdown and formation of bone. Abnormal remodeling of bone results in weak bones prone to frequent hip pain and hip fracture.
- Osteogenesis Imperfecta– Osteogenesis imperfect (OI) causes multiple joint and muscle pain. OI is also known as brittle bone. One of the symptoms of brittle bone disease is hip pain and complication is hip joint fracture.
- Benign or Malignant Cancer– Benign and malignant primary cancer of soft tissue and skeletal system spreads (metastasis) to skeletal system. Hip joint primary cancer or metastasis causes hip pain and may result in hip joint fracture.
- Cortisone Medications– Such as prednisone can weaken bones and fall or direct impact to hip joint can cause hip pain or hip joint fracture.
Symptoms of Hip Joint Fracture
- Hip Pain– Intense hip pain is felt immediately following accident involving hip joint. Movements of the injured hip results in to intolerable pain.
- Ambulation– Patient is unable to walk or change position of the painful injured leg following hip joint fracture. Hip pain if not associated with hip joint fracture will allow the patient to move his leg and follow instructions.
- Sensory Deficiency– Symptoms like tingling and numbness are observed with hip pain following hip joint fracture. Femoral nerve injury causes symptoms of tingling, numbness, or numbness in front of thigh and knee joint. Sciatic nerve injury causes symptoms like tingling and numbness spread over lower leg and feet.
- Weakness in Extremity– Hip pain caused by hip joint fracture may be associated with weakness in injured leg. Weakness associated with hip pain or hip joint injury is caused by damage of motor segment of femoral or sciatic nerve. Motor nerves are distributed in muscles. Motor nerves coordinate muscle contraction to accomplish joint movement as guided by higher motor centers and brain. Damage to motor portion of the femoral or sciatic nerve causes weakness in patients with fractured hip joint.
Signs of Hip Joint Fracture
- Leg Deformity– Patient following hip joint fracture is unable to move and prefers to lie in bed. Injured leg measures shorter than normal leg at rest.
- Position Of The Injured Leg At Rest– Bed side examination of patient following hip joint fracture in emergency room suggests injured leg is short, externally rotated and flexed at knee joint. Patient is unable to move injured leg. Movements result in severe hip pain.
- Bruising– Skin bruising is seen over the fractured hip joint. Bleeding following hip joint fracture is either secondary to capillary oozing from injured bones and tear of blood vessels close to the joint. Blood is collected and spread around hip joint. Direct impact of hip joint causes bleeding within subcutaneous tissue resulting from injury or tear of subcutaneous blood vessels from impact. Bruising is subcutaneous spread of blood either from subcutaneous bleeding or spread of blood from injured hip joint to overlying subcutaneous tissue and skin. Underneath the bruised skin may be a fluctuating large hematoma. Hematoma (blood clot) is a soft fluctuating swelling surrounding the fractured hip joint.
- Lump or Swelling– Lump is observed following partial or complete hip joint fracture. Lump or swelling associated with hip pain and hip joint fracture is either soft fluctuating or hard. Soft fluctuating swelling is secondary to hematoma (blood collection). Hard lump is caused by end of fractured bone protruding through muscles.
- Signs of Nerve Injury– Anterior displacement of fractured segment of hip joint causes femoral nerve damage. Similarly posterior displacement of fractured femur causes sciatic nerve damage in hip joint fracture. Neurological examination of injured leg following hip joint fracture may evaluate sensory or motor nerve deficiency caused by nerve injury.
- Sensory Nerve Injury– Sensory nerve injury causes numbness and tingling of the leg distal to the injured nerve.
- Motor Nerve Injury– Femur or sciatic nerve injury causes paralysis of muscles supplied by these nerves.
- Inability To Walk or Ambulate– Patient following hip joint fracture is unable to ambulate or walk because of following reasons-
- Severe Hip Pain– Severe excruciating hip pain with any activities of hip joint restricts activities and ambulation.
- Fracture of Femur– Fracture of femur caused by hip joint fracture eliminates continuation of proximal and distal segment of the leg bone. Leg movement is compromised by lack of continuation of two segments of the leg.
Investigations To Diagnose Hip Joint Fracture
X-Ray To Evaluate Hip Joint Fracture– Diagnostic X-ray of the hip joint is done either at emergency room or doctor’s office following injury. Antero-posterior and lateral view of the hip joint will show partial or complete hip joint fractures. Small hairline or stress hip joint fracture is difficult to diagnose with plain x-ray.
MRI To Evaluate Hip Joint Fracture– MRI radiological study is performed following X-ray diagnosis of hip joint fracture to evaluate further details of fracture. Indications for MRI examinations-
- Continuous Hip Pain- Rule out hairline or stress fracture.
- Diagnose Fracture Of Femur.
- Diagnose Fracture Of Pelvis Portion Of Hip Joint.
- Evaluate Hematoma,
- MRI study is also indicated to evaluate femoral nerve and sciatic nerve to rule out injuries.
CT Scan To Evaluate Hip Joint Fracture– CT Scan is an alternative radiological study, an alternative to MRI. Cat Scan is performed following X-ray diagnosis of hip joint fracture to evaluate further details of fracture. Indications for CT scan are-
- Evaluate fracture of femur segment of hip joint.
- Evaluate fracture of pelvis portion of hip joint.
- Evaluate hematoma.
- Evaluate femoral and sciatic nerve injury.
Ultrasound To Evaluate Hip Joint Fracture– Ultrasound Studies Are Performed For Following Reason:
- Fractured Hip Joint
- Evaluate Hip Joint
- Evaluate femoral nerve and sciatic nerve to rule out injuries.
- Examine sciatic and femoral nerve
Bone Density Test To Evaluate Hip Pain– Bone density test measures the bone mineral content and thickness of the bone. Findings of Bone Density Test Suggesting Osteoporosis Are As Follows-
- Decreased Bone Mass
- Brittle Bone
- White Blood Cell Count Examination (WBC)– WBC study is performed to rule out infection. WBC count is increased in infection.
- Hemoglobin (Hb)– Hb count is reduced in anemia caused by bleeding and loss of blood following injury.
Treatment For Hip Joint Fracture
- NSAIDs– For inflammation and pain.
- Opioids- For pain
- Muscle Relaxants- For muscle spasm
- Antibiotics- For infections
- Calcium and Vitamin D- For deficiency and osteoporosis
Physical Therapy For Hip Joint Fracture
- Skeletal Traction– Traction is contraindicated in femoral neck fracture due to it affecting blood flow to the head of the femur
- Muscle Strengthening– Exercises are performed under supervision of physical therapist to strengthen muscles supporting hip joint.
Surgery To Correct Fractured Hip
Screws And Plate Placement To Repair Hip Fracture: Plate is placed along the surface of the femur and anchor to bone by inserting screws through the metal plate. Metal plate holds the fracture segments until fracture is healed. Plate is either removed or left in place once fracture is healed. Following fractures of hip joint are treated using plate and screws.
- Inter-Trochanteric Fracture
- Sub-Trochanteric Fracture
- Fracture Of Greater And Lesser Trochanter
- Fracture of Acetabulum
- Fracture of Pelvis
Insertion of Rod In To Femur Bone–
Rod or nail is inserted through the neck of the femur or upper shaft of the femur and anchor to shaft of the femur by using thin plate and screws. Following fractures of hip joint are treated using plate and screws.
- Sub-Trochanteric Fracture
- Sub-Capital Fracture
- Fracture of Neck Of Femur
Partial Hip Replacement
Head and neck of femur is replaced with metal prosthesis with intact acetabulum. Also known as hemi-arthroplasty. Following fractures of hip joint are treated using plate and screws.
- Sub-Capital Neck Fracture
- Trans-Cervical Neck of Femur Fracture
Total Hip Joint Replacement
Head and neck of the femur is replaced along with acetabulum. Surgery is performed mostly if avascular necrosis follows fracture of hip joint. Surgery is also known as arthroplasty. Following fractures of hip joint are treated using plate and screws.
- Sub-Capital Neck Fracture.
- Trans-Cervical Neck of Femur Fracture.
- Acetabular Fracture.
Prevention Of Hip Joint Fracture:
- Calcium Pills– Regular blood examination should be done to evaluate calcium level and also rule out osteoporosis. Calcium pills should be taken if necessary to prevent fracture of hip joint resulting from calcium deficiency, skeletal structural weakness or osteoporosis.
- Vitamin D– Vitamin D is prescribed with Calcium when necessary to prevent calcium deficiency and weaknesses in skeletal system.
- Estrogen– Females following menopause are treated with estrogen to prevent disease such as osteoporosis, which may cause fracture of hip joint following fall or injury.
- Bisphosphonate– Enhances bone density and prevents osteoarthritis. Medication is prescribed either oral or intravenous to prevent hip joint fracture.
- Regular Exercise – Regular walking, jogging or stationary exercises helps to prevent injuries of muscles, tendon and bones. A regular exercise optimizes strength and stability of musculoskeletal system.
- Calcium Rich Diet– Increase intake of calcium rich diet like milk, cottage cheese, yogurt, sardines, and broccoli helps to prevent weakness of bones by preventing demineralization of skeletal system.
- Smoking– Smoking causes tissue hypoxia (low oxygen supply) and musculoskeletal weaknesses. Smoking also prevents rapid healing of injured tissue. Smoking should be discontinued following menopause to prevent hip joint fracture.
- Alcohol Intake– Alcohol interferes with Calcium metabolism and may cause weakness in skeletal structure. Excessive alcohol intake can cause cirrhosis of liver and interfere with calcium metabolism. Excessive drinking may cause accidental fall and hip joint fracture.
- Avoid Obstacles– Prevent accidental fall at home or work place. Fall often causes fracture of hip joint. Avoid or eliminate obstacles if observed in passage or staircase.
- Slip and Fall on Wet Surface– Common cause of joint fracture in elderly patient is slip and fall outside bathroom. Fall on wet surface can be prevented by keeping surface dry, preventing water spill outside bathroom or placing slip-resistant rugs next to the bathtub. Install bars and hand railing outside and around bathtub and bathroom. Installing adequate bright lights in living room, bathroom and corridor prevents fall and fracture of hip joint.
Complications Following Hip Joint Fracture
- Immediate Complication–
- Bleeding– Profuse bleeding may occur around fractured hip joint following injury. Bleeding may be secondary to oozing of blood from capillaries and tear of smaller blood vessels located close to fractured hip joint. Occasional major blood vessel like femoral artery may be torn with injury causing profuse bleeding.
- Nerve Damage– Hip joint fracture may be associated with femoral nerve or sciatic nerve damage. Anterior displacement of fractured segment causes femoral nerve damage and posterior displacement of fracture causes sciatic nerve fracture.
- Delayed Complications– Delayed complications are mostly secondary to prolonged immobility and bed rest.
- Deep Vein Thrombosis (DVT)– DVT is caused by prolonged bed rest. Venous blood flow is slow and sluggish in lower extremity during complete bed rest. Circulation can be improved by regular exercise resulting in repeated contraction of calf muscles. Muscle contraction squeezes blood vessels and propels blood forward. Severe pain restricts any movement and activities of the injured leg resulting in calf and thigh muscles inactivity and formation of DVT.
- Embolism– Detached (separated) blood clot from DVT moves through blood vessels to distant organs.
- Pneumonia– Prolonged inactivity causes retention of lung secretions and pneumonia.
- Muscle Atrophy (wasting of muscle tissue)– seen after prolonged bed rest following fracture of hip joint.
- Bedsores from lying in the same position with minimal movement following fracture of hip joint.
- Heart Attack or Myocardial Infarction– Severe pain, anxiety and anemia secondary to blood loss may induce heart attack.
- Delirium or Mental Confusion– Complete bed rest, injury and metabolic abnormalities may cause delirium after hip fracture.
- Urinary Tract Infection– Frequent urinary retention, bed rest and inadequate urinary elimination cause urinary tract infection.
- Complications of Fracture Healing–
- Non-Union– Non-union of the fracture segment is seen in 20% of fracture of the neck of the femur. Nonunion complication frequently follows ischemic necrosis of neck of femur. Most of the non-healing is observed in nonsurgical treatment. Non-Union of fracture hip joint can be treated with hip joint instrumentation.
- Mal-Union– Fracture may heal in distorted position. Mal-union occurs because of the imbalance caused by muscle pull and contractions in opposite direction. Mal-Union causes shortening and deformity of lower extremity. Mal-Union is observed when partially displaced fracture is treated with closed reduction and conservative treatment. Such complication is treated with instrumentation surgery.Deformities caused by Mal-Union are as follows-
- Varus- Inward Angulation,
- Valgus- Outward Angulation,
- Rotation- Leg is rotated inward or outward,
- Avascular Necrosis– Avascular necrosis is secondary to lack of blood supply to adjacent bone of the fractured hip joint. Avascular necrosis is often seen in total displaced and partially displaced hip joint fracture. Avascular necrosis is uncommon following hairline or non-displaced fracture.
- Post Surgical Wound Infection– Incidence of postsurgical infection is about 2%. Post- surgical infection is often superficial and if not treated appropriately may cause infection of deeper tissue. Infection of deep tissue may spread to bones and tissue around prosthesis. Infection is extremely difficult to treat if spread around prosthesis. Prosthetic instruments lack blood vessels and defense system floating within blood vessels like white blood cells (WBC). WBCs are necessary to eliminate bacteria and viruses causing infection. Antibiotics may not spread through capillaries close to prosthesis. Resistant to antibiotics and persistent infection often results in removal of prosthesis.
- Implant Failure– Instrumentation treatment of fracture hip joint may fail because of breakage, dislodgement or displacement of the prosthesis, plates or screws. Such complications are observed because of poor surgical skill, hyperactive patient, patient not following postoperative instruction or occasionally following a post surgical fall.