This is the most comprehensive guide to hip replacement surgery.
In particular, we're going to clear up:
what are the pros and cons about the surgery;
what are the post-operative risks and possible complications;
what are the do's and don'ts after the prosthesis surgery;
Let’s get started.
What is hip replacement?
Hip replacement is the substitution of the hip joint with an artificial prosthesis.
It is the most complex surgical treatment to fix a compound fracture of the femoral neck.
The replacement can be:
Total (also called arthroplasty): the head of the femur and the concave component of the hip, the cup, are completely replaced;
Partial (endoprosthesis): it only consists in the substitution of the femoral portion;
Resurfaced: the femoral head is not removed but completely resurfaced, capped with a smooth metal covering;
Cemented: in very elderly patients, with poor bone quality and/or in the presence of associated bone pathologies (such as osteoporosis), an acrylic cement is applied to give more stability to the prosthesis.
The hip arthroplasty consists of two components, the femoral part, which is inserted into the bone marrow, and the cotyloid part, which is fixed to the pelvis.
It is recommended in patients between 60 and 75 years.
A fixed dome, defined as the prosthetic head, is applied to the femur and inserted into the fixed component in the pelvis.
On the contrary, in the endoprosthesis, only the femoral portion is replaced, without performing any particular surgical treatments on the pelvis joint.
If the cartilage is in good condition, there is no need to do any hip surgery.
A metal head (dome) is applied to the femur, which articulates with the patient's cup.
It is recommended in patients over 75 years, because it is simpler, faster and less risky for the elderly patients.
Furthermore, with a total hip prosthesis, post-operative precautions are few.
On the other hand, the resurfacing prosthesis only provides the resurfacing of the acetabular component and the femoral head, thus replacing the cartilage worn by arthrosis.
The advantage of this type of prosthesis is that it does not upset the anatomical profile of the joint and, consequently, avoids length differences of the limbs.
It also reduces the risk of implant dislocation (luxation).
Cemented prosthesis allows you to quickly recover the limb strength after the operation, giving you the possibility to walk almost immediately, and avoiding the complications due to immobilization.
The load on the limb is to be considered complete already after the operation.
Conversely, if the prosthesis is not cemented, it is recommended to limit the load on the operated limb, from the first postoperative week, up to 3 months, the right time for an effective rehabilitation.
The difficulty during the walk in the first postoperative period is caused by the inhibition that the body adopts to protect all the affected structures.
So all the muscles, joints, the nerves, etc., are working a bit slower than normal.
It is recommended in patients over 60 years old.
However it is contraindicated, for patients who are severely overweight or are physically very active.
How is hip replacement surgery done?
The standard accesses used during prosthesis surgical procedures are:
Posterolateral access: This type of surgery is the most frequently used.
It allows short surgery times, less blood loss and less risks of infections.
This type of surgery gives excellent hip stability in the next post-operative period, it does not interfere with the adductor muscles (the muscles that bring the knees together when we stay in a sitting position), and avoids losing their strength in the immediate period of convalescence.
2. Lateral access:
It is the most used technique to access the upper third of the femur, but it involves the splitting of the vastus lateralis muscle, fascia lata tensor and the partial dissection of the tendon insertion of the gluteus medius.
This type of access can lead to a depletion of the hip abduction mechanism and consequently it may be more difficult for the patient to bring the leg outward.
An adequate physiotherapy strength protocol, can further reduce muscle weaknesses and fix walking abnormalities (as occurs in Trendelenburg's sign).
3. Anterolateral access:
It is mostly reserved for operations such as revision or reconstruction arthroplasty, in patients with muscle imbalances caused by neurological pathologies, in which posture and gait are characterized by a flexion and an internal rotation of the hip.
This is the main reason why the first approach (the posterior-lateral) is absolutely not indicated.
The advantage of this type of access is that it guarantees excellent stability in the period following the operation, but the cons are that more structures are cut and repositioned, compared to the other two approaches.
4. Minimally invasive approach:
The aim of this approach is to reduce complications to the soft tissues during the operation.
The skin incisions are 10 cm maximum and this helps:
the recovery time of the structures during the period in hospital or when you return back home;
blood loss reduction during surgery;
postoperative pain reduction;
lower limb mobility recovery times;
the scar which, in addition to being aesthetically better, avoids creating excessive tissues adhesions, and consequently hypertrophic or hypotrophic keloids;
most of the muscles are not injured during the operation, and the insertion of the prosthesis.
What types of materials are hip prostheses made of?
The most commonly materials used in hip prostheses are:
the stem is made of a metal alloy of cobalt-chrome and titanium and is covered with porous materials capable of promoting osseointegration within the femoral marrow;
the head, usually in ceramic, plastic, or more rarely in metal and is positioned on the collar of the stem;
the insert is made of a type of plastic called polyethylene;
the cup is made of a titanium alloy; it is lined with a thin layer of porous material, as it allows bone growth. The holes in the dome were created in case of need to keep the structure more in contact with the acetabular cavity of the pelvis, using screws.
What is the surgical program and how is it performed?
The hip replacement surgery program is already planned and consists of the following phases:
During your hospitalization, the medical-nursing staff will give you all the information about your hospital stay, including various controls, x-rays and blood sampling.
The blood sample taken will then be stored, in case it proves necessary for a transfusion, which will allow it to replace the normal blood loss during the operation.
You will receive a visit from the anesthesiologist, in order to evaluate your general conditions and suitability for anesthesia and to give you all the necessary information about the prosthesis surgery.
Some tests will be performed before undergoing definitive surgery, including:
assessment of the pain perceived at the current time of the visit;
past and current medical history;
examination of joints range of motion;
gait test and the need for assistance during walking;
leg length measurement.
The day after the surgery treatment:
The next day after the operation, the limb will be placed in a rubber foam support (called splint), which has to be kept for a few days, because it helps to contain and immobilize the limb.
The bags and drains have the purpose of avoiding the formation of thrombosis and are removed after 24 - 48 hours.
A physiotherapist will give you the necessary instructions to walk with a walker or a rollator and in the next phase with crutches, how to go upstairs and downstairs.
Length of the hospital stay:
The hospital stay length is on average 7 days.
It can last up to two weeks, if a patient's clinical conditions require extended times.
What not to do after hip replacement surgery?
The following indications consist of postures and/or movements you absolutely have to avoid, because they can cause a dislocation of the implant.
You should pay this kind of attention from the first postoperative period, up to at least three months after the surgery.
When you are lying in bed in a supine position (with your face pointing upwards):
do not cross your legs;
if the bed is too low, lift it with risers;
do not lie on the operated side;
do not rotate the upper body towards the non-operated side when lying down, as you’re trying to reach something on the table near the bed (the operated limb ends up in adduction through this movement).
When you’re sitting on the bed or on a chair:
do not cross your legs;
the seat must not have the angle between the leg and the pelvis greater than 90°;
the knees must always be kept below the height of the hips;
don't sit on low or too soft chairs;
don't lean forward to pick up things from the ground or to tie your shoes.
When you are standing:
do not cross your legs;
avoid twisting your upper body to both the right and left sides;
don't lean forward to pick up objects from the ground or crutch if it falls on the floor;
when you change direction, do not pivot on the operated leg, but on the other one, or make small steps.
In the bathroom:
use a toilet bowl that avoids to keep the knees above the height of the hips;
have a shower sitting on a raised chair or, if there is a stable surface under your feet, and you can stand independently;
don't lean forward too much to brush your teeth.
What are the pathologies and problems that may require a hip prosthesis?
bone tumors and neoplastic diseases;
failure of the conservative treatment or previous surgical reconstruction (e.g. osteotomy, resurfacing, femoral stem hemi-arthroplasty, total hip replacement);
What are the contraindications to a total or semi-total hip replacement?
joint infection currently present;
systemic infection or sepsis;
significant loss of bone after cancer;
severe paralysis of the muscles surrounding the hip joint.
localized infection of the bladder or skin;
gluteus medius insufficiency;
progressive neurological disorder;
progressive bone disease, which compromises the femoral bone;
young patients participating in high-impact physical activity.
What are the general guidelines about taking the decision of a hip replacement surgery?
It is indicated for both young and elderly patients, still in good health, even in the presence of a femoral bone fracture.
It is performed in patients between 60 and 75 years old.
It is only used in very elderly patients who have suffered a fracture of the femur.
It is given to patients over 75 years old, because it is simpler, faster and less risky.
The choice of an endoprosthesis reduces surgical times and, therefore, the operative risks, allowing a rapid recovery of walking.
It has the advantage of sacrificing less femoral bone and, therefore, is suitable for young patients who, above all, want to go back playing sport, since the large dimension of the prosthetic head avoids prosthesis luxation.
What are the general guidelines about taking the decision of a hip replacement surgery?
debilitating pain affecting daily living activities;
severe hip pain during movement;
severe limitation of the hip joint range of motion;
failure of conservative treatments (e.g. drugs, physiotherapy, etc.);
the patient is medically fit for surgery;
no active infections, anywhere;
Which exams have to be done before a hip replacement surgery?
The diagnostic procedures are made before the surgical treatment of the hip, with the aim to investigate the state of health of the coxo-femoral joint (medical term to define the hip joint).
Each exam provides a high degree of specificity, based on the current suspected pathology that doctors are trying to identify:
It is performed on two projections, posterior-anterior and lateral.
Radiography allows to identify the actual condition of osteoarthritis based on:
the reduction ratio of the joint space;
femoral head deformity.
It also highlights pathologies such as femoral head necrosis, dysplasias and dislocations of the femur.
It allows to identify joint inflammation and necrosis.
It specifically highlights the area where there is a lack of vascularization (when the blood supply to the femoral head is insufficient compared to the normal physiology of the joint).
Nuclear Magnetic Resonance (MRI):
It highlights accurately the necrosis of the femoral head and the areas in which femoral cells are beginning to die.
It is able to highlight synovial hypertrophy during inflammatory and rheumatic pathologies (for example rheumatoid arthritis), (inflammation of the synovial membrane) and intra articular effusion (increase of fluid inside the joint).
It is a diagnostic test that reconstructs the hip joint three-dimensionally.
It allows to identify malformations and/or congenital deformities, like dysplasias, childhood pathologies and traumas.
What are the complications after hip replacement surgery?
General complications of hip arthroplasty surgery are the same that affect all large joint surgeries such as:
prosthesis dislocations: this is a very dangerous event, which causes to the patient very severe pain and a total functional impotence (the subject is no longer able to move the leg until the event has been resolved);
risks of falls that can lead to a bone fracture, and the prosthetic component; mobilization of one or both prosthetic components due to mechanical failure of the implant (mobilization) or due to biological failure;
risk of crural nerve and/or sciatic nerve neurological damage when trying to balance the limb length;
implant infection (the prosthesis is always a foreign implant within the body and can act as a decoy for any bacteria that have penetrated into the surgical site during the surgery);
different length of the lower limbs: osteoarthritis causes a deterioration of the bone cartilage and consequently a progressive shortening of the limb, therefore the surgeon slightly lengthens the limb to better ensure the stability of the prosthesis and avoid dislocation risks as much as possible;
detachment of the prosthetic components.
The end solution, in case of implant failure and even standard conservative methods such as antibiotics and implant cleaning are not enough, there is a particular surgical procedure called reimplant.
Prosthetic reimplantation consists in the further replacement of one or more components of the prosthesis:
Partial reimplantation: replacement of the cup or prosthetic stem;
total reimplantation: replacement of the cup, stem and other related structures.
At first, the surgeon removes the previous prosthetic implant and then all the components that:
have suffered a fracture or deformation;
have been mobilized and came out from their site;
have been cemented, removing it.
Once the first “cleaning phase” of the hip has been completed, the surgeon proceeds with the reimplantation.
If there may have been some bone loss due to the removal procedure of the previous prosthesis, they proceed with a bone graft (generally the bone interposition is taken from the iliac crest, the bone of the pelvis which you can perceive from both sides of the waist).
How long does a hip replacement last?
Prostheses have an average life of 15-20 years depending on the patient and the daily living activities.