What is Minimally Invasive Total Hip Replacement?

The total hip replacement, also called total hip arthroplasty involves replacing the damaged sections of the hip joint with an artificial joint (prosthesis). Such artificial joint is usually made of metal, ceramic, and very hard plastic. The conventional total hip replacement will be performed through a 10 to 12 inches long incision made on the side of the hip.

On the contrary, the minimally invasive total hip replacement surgery, uses minimally invasive techniques and a small amount of skin, muscle, and other soft tissues that must be cut (typically 3 to 5 inches long). A minimally invasive approach is successfully performed through one or two smaller incisions rather than the single long incision as in the traditional approach. Such an approach offers advantages like lesser muscle dissection, minimal pain, quicker and easier recovery, smaller scars, and faster rehabilitation compared to traditional hip replacement surgery.

Who are eligible for Minimally Invasive Total Hip Replacement surgery?

Some conditions that damage the hip joint make the total hip replacement surgery necessary, as listed below.

• Rheumatoid arthritis: This condition is caused by an overactive immune system, and produces severe inflammation that can erode cartilage and even underlying bone sometimes. This can result in damaged and deformed joints.
• Osteoarthritis.: It is also known as wear-and-tear arthritis, damaging the slick cartilage covering the ends of bones and helping joints move smoothly.
• Osteonecrosis: For some people, dislocation or fracture can result in less blood supply to the ball portion of the hip joint such conditions can result in bone collapse or deformities injuring the total hip joint.

Some of the symptoms listed below may also need hip replacement surgery.

• Persistent pain despite taking pain medications.
• The pain worsens with walking, even with support.
• You cannot rest or sleep because of constant dull or severe pain.
• Affects your ability to use the stairs
• Makes it difficult to rise from a seated position
• Aching knee pain with stiffness
• Limping while walking to avoid pain

Diagnosis

Diagnosis is made by evaluating your symptoms, diseases or disorders, medical history, physical examination, and X-rays. Additionally, imaging tests such as MRI and CT scans may be needed to confirm the diagnosis.

The suitability and your eligibility to undergo the Minimally Invasive Total Hip Replacement surgery will be decided by your surgeon based on your diagnosis. Some of the common conditions which make the minimally invasive surgery less suitable or create a higher risk of complications or unsuitable are listed below.

• Elderly adults
  
• Overweight or obese
• Significant deformity of the hip joint
• Have undergone previous hip surgery
• Osteoporosis (osteoporosis increases the chance of bone breakage)
• Very muscular
• Heart problems
• Disorders of slow wound healing

Surgical procedure 

The accurate diagnostic evaluations play a crucial role in the surgery and treatment plan. Your surgeon may recommend minimally invasive total hip replacement surgery for patients with severe cartilage damage, when conservative treatment options fail such as anti-inflammatory medications, and as physical therapy do not relieve the symptoms.

Artificial implants: Artificial implants are the same as traditional hip replacements, however, the difference is minor incisions and minimal soft tissue dissection. The surgery is performed under general anesthesia through one or two smaller incisions.

• The replacement surgery can be performed with one or two small incisions to minimize tissue disturbance and damage. Furthermore, the surgery is done using the posterior, lateral, or anterolateral approach.

Single small-incision surgery: In this procedure, the surgeon uses a single incision of 3 to 6 inches. The length of the incision may depend on the size of the patient and the suitability of the procedure. Your surgeon will make an incision on the side or back of the hip. The muscles and tendons will be split gently from the hip to a much lesser extent than in traditional hip replacement surgery. It is then routinely repaired after the surgeon places the implants. This encourages healing and helps prevent dislocation of the hip.

Multiple small-incision surgeries: Your surgeon may perform the surgical procedure through two separate small incisions. The approach is through the pelvis (cup) by one incision and another in the femur (thighbone) through a separate incision. Approaching the hip in this manner can cause less disruption of the underlying tissues than in one incision. During this procedure, the surgeon may often use X-ray guidance to ensure the proper placement of the implants.

• There are two common minimally invasive total hip replacement surgeries based on incision location.

Direct anterior approach: The direct anterior approach involves less disruption of the underlying tissue and muscle. In this method, the surgeon makes the incision on the front of the hip and less cutting of the muscle is needed, and thus the recovery is reported to be faster. This procedure is often performed with the use of a special operative table and instruments. Most of these surgeries will either need 1 to 3 days in the hospital when no complications arise.

The posterior approach: This procedure involves the replacement of the damaged hip joint through the side of the hip, along the outer buttock area. It is the most commonly used approach with a single incision of about 5 inches usually.

Post-operative precautions after Minimally Invasive Total Hip Replacement surgery

After the surgery, you must take care to ensure proper healing and prevent another dislocation. Physical rehabilitation is a critical component of recovery. Your surgeon will recommend specific exercises or direct you to a therapist to help increase your range of motion and restore your strength. Some of the crucial precautions for 6 weeks, are listed below.

• Use an elevated toilet seat
  
• Never cross your legs
• Never bend your hips past a right angle (90°)
• Avoid sitting on low chairs
• Keep a pillow between your legs while sleeping.
• Avoid bending down to pick up things
• Avoid combined movement of bending your hip and turning your foot inwards

What are the risks & complications?

The minimally invasive total hip replacement surgery has a risk of complications like every other surgery. A few of these complications are listed below.

• Dislocations
• Infections
• Blood clots
• Nerve and artery injuries
• Delayed wound healing
• Fracture of the femur
• Differences in Leg length