Hip joint is a ball and socket joint. Head of the femur (ball) attaches to the acetabulum (socket) to form the hip joint. Any injury to the joint may cause fracture or dislocation of the joint.Unlike shoulder joint hip joint is more stable and capsule along with muscles and tendons adds to the stability of the joint. Ligaments of the hip joint capsule are one of the strongest and biggest in the human body. Depending on the severity of the injury and the age factor the treatment plan for hip injuries is set.
Break in upper thigh bone (femur upper end), near hip joint is termed as the hip fracture.
Depending on the site of fracture, the hip fracture can be classified as follows:
- Fracture at the neck of femur
- Intertrochanteric fracture
- Subtrochanteric fracture
- Greater tuberosity fracture
- Fracture of lesser tuberosity
- Combination of above (most complex hip fracture to treat)
The cause of fracture can be:
- Direct injury to the hip bone by an impact or fall
- Twisting injury in already weak bones
- Road Traffic Accidents (RTA)
- Weaken bones due to disease like osteoporosis
- Fall from height
Patient complains of:
- Inability to walk, stand, move the affected limb
- Unable to bear weight on the affected leg
- Pain and swelling in hip region
- Leg shortening, deformity
- Difficulty in performing hip movements
Diagnosis can be confirmed using x-ray
and CT scan; MRI is rarely required.
Treating hip fractures often requires surgery because:
- There is no possibility of any immobilization in a plaster or splint (except in the small children)
- Blood supply to the proximal area (head of femur) is cut off, due to fracture
- Proximal area being too small, makes it difficult to maintain reduction and achieve it
- Internal fixation can be done using implants to prevent displacement. Implants also allows early post-operative mobilization.
The various options for the surgery includes are:
- Only screw fixation (for the neck of femur fracture)
To fix hip joint internally the various screws used are:
- Multiple cancellous screws in union configuration (3-4 screws)
- Multiple Knowle’s pin or Moore’s pin, for children
- Screws along with plate fixation (for neck of femur, intertrochanteric fracture, sub-trochanteric fracture, tuberosity fracture)
- DHS (dynamic hip screw)
- DCS (dynamic condylar screw)
- Proximal femur plate
- PFN (proximal femur nailing)
It is a minimal invasive procedure used for internal fixation of proximal femur fracture
- Hip replacement
Often chosen when the blood supply to the fracture area is cut off
Different types of hip replacement done are:
- Unipolar hip replacement
- The movement occurs between the prosthesis and the acetabulum
- Bipolar hip replacement
- There is an artificial extra joint between the two components of the prosthesis
- Total hip replacement
- The head and neck of the femur along with the socket of the pelvis is replaced with prosthesis
After surgery care
Post surgery the patient is advised for rehabilitation program (physiotherapy), which includes:
- In bed mobilization
- Range of motion exercises
- Strengthening exercises
- Weight bearing (may be delayed)
- Toilet training
- Breathing exercises
Hip fracture surgeries have 5-10% complication rate even in the best centers of the world.
Certain complications associated with hip fracture are:
- Non union
- The fractured fragment may not unite or union may get delayed depending on the blood supply to the fractured area and lifestyle of the person (history of tobacco, smoking and diabetes)
- Avascular necrosis
- Due to obstructed blood flow avascular necrosis of the head of the femur may occur. Head of femur gradually collapses, loses its round shape, becomes elliptical causes arthritis in long term
- Occurs few years after the surgery
- Result of avascular necrosis, non union, mal union or implant related
- Mal union/ shortening
- Very common outcome as fracture heals with some bone collapse
- Other complications/ outcomes are
- Deep Vein Thrombosis (DVT)
- Fat embolism
- Implant failure
Hip replacement is a surgery which involves changing either one part of the hip joint (head of the femur or acetabulum) or whole hip joint with a metal/ ceramic/ polythene (composite) prosthesis.
The hip joint prosthesis are made up of 3 different components:
- Acetabular cup
- Femoral component
- Articular interface
Hip replacement surgery can be classified into 2, depending upon how they are fixed to native bones to substitute the head of femur
Cemented replacement anchors the implant to the patients bone using PMMA bone cement. This allows early mobilization and weight bearing. This is especially useful in patients with severe osteoporosis, chronic diseases (kidney/ liver failure, rheumatoid arthritis).
The chances of loosening of the cemented prosthesis in the long run or over a period of 10-15 yrs is higher as compared to uncemented prosthesis.
Uncemented replacement is when the implant is directly fixed to the native bone. The implant is designed such that it allows the bone to grow into the implant. This improves the longevity of the implant, though it takes more time to start weight bearing as compared to cemented prosthesis.
The uncemented hip replacement has 5 components:
- Metal shell
- Titanium screws to fix metal shell to the acetabular bone
- Polyethylene liner
- Metal/ ceramic head
- Metal stem which engages into the femur (thigh bone)
The durability of uncemented hip replacement is more as compared to cemented hip replacement.
Depending on the number of components used hip replacement surgery can be divided into:
- Total hip replacement
Unipolar hip replacement involves one piece prosthesis to substitute for head of femur, promotes movement between the prosthesis and acetabulum.
Bipolar hip replacement has an extra artificial joint Incorporated in the artificial prosthesis which means, ball and socket both are Incorporated in a single prosthesis.
TOTAL HIP REPLACEMENT
In total hip replacement both the head of the femur and the acetabulum is replaced with an artificial prosthesis, usually metal/ ceramic head, metal stem and metal/ ceramic cup.
The different conditions in which hip joint replacement is indicated are:
- Arthritis (joint degeneration)
- Old age (with fracture of neck/ head of femur)
- Avascular necrosis (degeneration of joint due to disturbed blood circulation of the ball of the hip)
- Post traumatic arthritis (arthritis after fracture around the hip)
Common adverse events associated with hip replacement are:
- Blood clotting in leg veins (Deep Vein Thrombosis), causing respiratory distress (pulmonary embolism)
- Leg length discrepancy (shortening or lengthening)
- Peri prosthetic fracture (acute or subsequently following a fall)
- Osteolysis and loosening of implant
- Metal allergy
- Breakage of implant
Post operative care (After surgery care)
Pre operative management includes strengthening of hip joint muscles and early mobilization to prevent complications associated with recumbency (prolonged bed rest)
Post operative management includes:
- In bed exercises
This includes ankle-toe-movements, ankle and knee isometrics, knee bending
- Bed side ambulation
- Full weight bearing mobilization
- Stair climbing
- Gait training
- Muscle strengthening
Do’s and don’ts
The common do’s associated with hip replacement are:
- Abduction pillow/ splint
- Allow limb exercises
- Elevating the limb and ankle-toe-movements
- Diet rich in fibre and calcium
- Plenty of fluids orally (to prevent DVT)
- Follow your customized post-operative rehabilitation program
- Follow up with your doctor at prescribed intervals
- If you are obese or at higher risk for DVT, continue medications for same for 6-12 weeks post-operative
The don’t of hip replacement are:
- Don’t lie on the affected side for 6-8 weeks
- Don’t sit on floor
- Don’t squat (Indian toilet seating)
- Don’t sit cross legged
- Don’t use low seating (less than 2 feet above the ground)
- Don’t indulge in contact sports like rugby, soccer, basketball for the first 6-8 weeks
- Don’t turn sides without pillow between the thighs
Hip reconstruction is a surgery done to improve longevity of the hip joint and delay hip arthritis or need for hip replacement.
Hip reconstruction surgery is most commonly done in younger age groups 15-35yrs.
It helps to improve coverage and alignment.
When to opt for hip reconstruction?
In following conditions hip reconstruction surgery can be done:
- Perthes disease
It is a childhood condition that occurs due to improper blood supply to the hip joint.
- SCFE (Slipped Capital Femoral Epiphysis)
In SCFE the head of femur slips off the neck of the femur. Most common in obese adolescents.
- DDH (Developmental Dysplasia of Hip)
DDH is a condition in which the ball and socket joint of the hip doesn’t match each other properly. The hip development in the early years after birth is affected and the normal spherical ball and socket joint doesn’t form.
- FAI (Femoral Acetabular Impingement)
It is a condition in young and medial age when an extra bone grows along the bone of the hip joint, causing pain in the movement and gives an irregular shape to the bone.
- Coxa valga
This is a disorder of the hip, when the angle between the head and shaft of femur is more than 135°. It is associated with increased chance of hip arthritis.
- Coxa vara
In coxa vara the angle between the head and shaft of femur of hip joint is less than 120°, here the patient has altered gait (walking pattern is disturbed) and long term chances of arthritis are there.
- Mal-union and non-union of hip fracture in younger age group
When bones don’t heal as per alignment it is termed as mal-union.
Non-union is when the healing period is more than expected.
- Septic sequelae
Deformity or mal-alignment arising out of infection in hip joint.
Benefits of hip reconstruction surgery
- Pain relief
- Improves mobility
- Gives better strength and coordination
Certain risks associated with hip reconstruction are:
- Stiffness of joint
- Instability of joint