Pinless Computer Navigated Knee Replacement

Many studies have demonstrated higher precision and better radiological results in Total Knee Replacement (Arthroplasty) with computer-assisted surgery (CAS). On the other hand, studies revealed a lengthening of operation time up to 20 min for this technique and demonstrated rare additional complications as fractures and neurovascular injuries caused by the array pins and any intraoperative array dislocation leads to abortion of CAS.

To combine the advantages and eliminate the disadvantages of standard CAS, a new and more simplified procedure has evolved referred to as pinless navigated knee replacement abandoning the reference pins and reducing the necessary workflow to a minimum.

Dr. (Prof.) Arora is leading the way in knee replacement surgery using pinless navigation technology. He owns and uses North India's first Pinless Computer Navigation system to give you assured results.

There are several reasons why pinless knee replacement is better than traditional computer guided surgery:

Better alignment of knee joint

Traditional computer assisted knee replacement necessitates the use of pins to attach the thigh and leg bone to ensure alignment. As a result, the procedure is time consuming and the possibility for complications is higher. The pinless method on the other hand uses an infrared tracker that communicates with the camera. This lets the surgeon know where he/she is with respect to the patient’s knee. The infrared camera acts as a GPS system and relays real time information back to the surgeon in the form of charts and graphs displayed on a computer screen. The displayed data gives the surgeon angles, lines, and measurements to accurately align the prosthetic knee.

At the completion of total knee replacement surgery, balancing the ligaments surrounding the knee has always been the most difficult and "subjective" part of knee replacement surgery. In conventional surgery the knee ligaments are balanced chiefly by the surgeons "feel" to determine if the ligaments are appropriately taut. Though experienced surgeons can achieve excellent ligament balance in most cases, reproducibility is difficult and results are subjective. With computer navigation, ligament balancing can potentially be quantified to the nearest millimeter of ligament laxity or tautness.

Fast recovery period

Pinless navigation procedure is a minimally invasive procedure that takes close to 45 minutes, making it faster than a traditional computer guided knee replacement surgery. Also, the advanced technique is more accurate, mimicking the natural alignment of the joint. All these factors help facilitates faster recovery post-surgery.

Less complication

Pulmonary Embolism is common complication that may occur following a tradition knee replacement. Pulmonary Embolism is caused by a blockage (blood clot) in one of the major arteries of the lung. This condition can be life threating and measure must be taken to prevent blood clots post-surgery. Pinless knee replacement surgery reduces the risk of a blood clot as the technique requires a less amount of time and a small incision.

The kind of surgery you need to undergo is usually decided by your surgeon with your preferences. However, the pinless surgery is thought to be the most effective form as it promises a perfect alignment and can be performed on extremely deformed joints too.

Computer Assisted TKR

Correct alignment of the component and soft tissue balancing have been cited as two of the most important aspects of successful knee replacement (arthroplasty). They are the most important predictors of longevity of knee replacement. Minor misalignment can lead to early loosening, early polyethylene wear and poor function.

Knees have traditionally been aligned using jigs either loosely clamped on to the outside of the leg or referenced from rods placed in the middle of the bones. The majority of knee replacements (prosthesis) can be implanted in a satisfactory position using this older technology. However, a proportion of components may be mal-aligned, potentially leading to poorer function and earlier failure.

Computer navigation in total knee replacement attempts to correct some of the problems faced in traditional total knee replacement.

Dr. (Prof.) Anil Arora and his team are among a very exclusive group of surgeons who have advanced training in computer navigation surgery and utilise this technique in the operating room.

The objective of computer-assisted surgery is to combine the precision and accuracy of computer technology with the surgeons’ skill and expertise. As a result, Dr. Arora and his team are able to achieve alignment of implants with a degree of accuracy not possible with the naked eye. This surgical procedure affords their patients enhanced results and recovery along with a quick return to normal life.

A computer-assisted knee replacement procedure begins with the Dr. Arora placing several small arrays on the patient’s leg. An infrared camera is used to track the movement of the arrays via a computer that analyzes the positions and creates an anatomical three dimensional drawing of the knee. Using this real-time graphic display, Dr. Arora makes cuts in the bone to ensure proper alignment on the mechanical axis for the implant. The implant is then secured with bone cement, tested to ensure proper alignment, and the incision is closed with stitches.

At the completion of total knee replacement surgery, balancing the ligaments surrounding the knee has always been the most difficult and "subjective" part of knee replacement surgery. In conventional surgery the knee ligaments are balanced chiefly by the surgeons "feel" to determine if the ligaments are appropriately taut. Though experienced surgeons can achieve excellent ligament balance in most cases, reproducibility is difficult and results are subjective. With computer navigation, ligament balancing can potentially be quantified to the nearest millimeter of ligament laxity or tautness.

Benefits of Computer Assisted Knee Replacement

Better balance and positioning of prosthesis

More accurate placement and alignment of prosthesis

Better functioning knee

Early return to active lifestyle for the patient

Dr. Arora has been using use this exciting technology for his knee replacements for the last several years. He has now accumulated a wealth of experience using this technique and has been involved in training other surgeons wishing to use the technology.

For a brief demo of the procedure, visit Computer Assisted Knee Replacement

Primary Knee Replacement (Arthroplasty)

Your knee is a hinge joint where the end of the thigh bone (femur) meets the beginning of the large bone in your lower leg (tibia). A healthy knee has smooth cartilage that covers the ends of the femur and tibia. The smooth cartilage lets the surfaces of the two bones glide smoothly as you bend your knee. The muscles and ligaments around the knee joint support your weight and help move the joint smoothly so you can walk without pain.

The smooth cartilage layers can wear down on the ends of the femur and tibia. When the smooth surfaces become rough, the surfaces are like sandpaper. Instead of the joint gliding when you move your leg, the bones grind and you have pain and / or stiffness.

This degeneration can happen due to variety of reasons such as the following:

Causes

Arthritis

Trauma (fracture)

Increased stress e.g., overuse, overweight, etc.

Connective tissue disorders

Inactive lifestyle etc.

Side effect from medicines, such as steroids

Inflammation e.g., Rheumatoid arthritis

When pain in your knee or leg prevents you from doing your usual activities and your x-rays show irregular surfaces at the knee, your doctor might suggest that you have a knee replacement.

A Total Knee Replacement (TKR) or Total Knee Arthroplasty is a surgery that replaces the worn or damaged parts of your knee joint with artificial metal or plastic replacement parts called the 'prostheses'. The procedure is usually recommended for older patients who suffer from pain and loss of function from arthritis and have failed results from other conservative methods of therapy.

To create a new knee joint, the ends of the bones forming the joint are surgically removed. They are replaced with parts like the pieces shown in the following video animation. The parts of the prosthesis are made of metal and very strong plastic. The pieces may be cemented in place with a special bone cement, or the metal may have a porous surface that bone will grow into to create a tight fit.

The following video animation displays how the new TKR prosthesis replaces your degenarated knee joint.

Your orthopaedic surgeon, Dr. (Prof.) Anil Arora, will encourage you to use your new joint as soon as possible after your operation. Patients often stand and begin walking the day of or the day after surgery. Physio therapy (PT) will begin in the afternoon of surgery or the day after.

Based on the surgery performed and what happens during your surgery, Dr. Arora will decide after surgery how much weight you can put on your surgical leg. This is called your Weight Bearing Status (WB Status). This may change throughout your hospital stay and your recovery from joint replacement surgery.

You will walk with a walker, then crutches or cane at first as you recover. Most patients have some temporary pain after joint replacement as the tissues heal and muscles regain strength. This pain should go away in a few weeks or months. Pain medication will be ordered for you and your pain level will be monitored. Your health care team will make every effort to keep you comfortable.

Regaining strength and motion after knee replacement surgery is dependent on you. Once you get back home and follow the exercises prescribe by your physio team you should be able to get most of your strength and mobility back.

With your new knee replacement and the help of your orthopaedic team, you may be able to resume most of the activities you once enjoyed. You may be permitted to go on long walks, dance, play golf, garden and even ride a bicycle.

Total Knee Replacement (TKR) has an excellent track record for improving quality of life, allowing greater independence and reducing pain.

Revision Knee Replacement (Arthroplasty)

Total Knee Replacement including partial knee replacement s have an excellent track record of lasting close to 15 years in 95% of cases. But, in some cases, knee replacements may wear out for a variety of reasons which include:

Aseptic loosening and Osteolysis (degeneration of bone tissue around the prosthesis)

Excessive polyethylene (plastic) wear

Instability

Infection

When problems with the previously implanted prosthesis occur, such as pain and stiffness, investigation into the cause is required and this generally determines whether a revision knee replacement is required. Dr. (Prof.) Anil Arora decides whether all components of the previous TKR need revision or one component only, for example the polyethylene (plastic) liner.

A revision knee replacement involves removing the old prosthesis and inserting a new one. These knee replacements usually feature a longer stem, which allows the component to be more securely fixed into the bone cavity. The components may also interlock in the centre of the knee to form a hinge to provide greater stability to the joint. Extra pieces of metal and/or plastic may be used to make up for any removed or badly damaged bone. All revision total knee replacement other than for infection are done in a single stage.

When a revision operation is carried out for infection, often the revision procedure is done in two stages. In the first stage the infected prosthesis (and the bone cement if it was used to insert the first prosthesis) is removed. All infected material and soft tissue is cleared from the knee, and samples are taken to confirm which bacteria are causing the infection. A temporary spacer, shaped like a knee prosthesis, can be inserted, and often antibiotics are left inside the knee. The temporary spacer allows knee bending to right angles and weight bearing with crutches. After a period of at least six weeks (or more, depending on when the infection is eradicated), the second stage procedure is performed, when the new prosthesis is inserted.

Post-operative care after knee revision surgery is very similar to the care of a primary knee replacement. This includes a combination of physical therapy, blood management, and pain medication as necessary. Antibiotics and some method of blood clot prevention will be continued in the postoperative period. A brace or splint may be used to protect the joint after the surgery.

Therapy will usually continue for up to three months following the surgery. Assistive devices, such as a walker or crutches, will be used early in the convalescence period, and patients will progress to a cane or walking without any assistance as their condition improves.

Revision TKR is a complex procedure that requires an experienced surgeon and proper pre-operative planning to achieve satisfactory outcomes.

Knee Osteotomy

Osteoarthritis can develop when the bones of lower limb do not line up properly. This can put extra stress on the inner (medial) side of knee. Over the time, this extra pressure on medial side can wear away the smooth cartilage that protects the bones, causing pain and stiffness in knee.

High Tibial Osteotomy is an effective surgery for the treatment of knee malalignment with associated pain and stiffness from arthritis in middle-aged active patients. Osteotomy literally means "cutting of the bone". In a HTO surgical procedure, the tibia (shinbone) is cut near knee joint and then reshaped to relieve pressure from medial (inner) side of the knee joint. By shifting weight off of the damaged medial side of the knee joint to normal side of knee, the surgery can relieve pain and significantly improve function of an arthritic knee.

It can correct poor knee alignment and delay the need of Total Knee Replacement by 10 to 15 years. Another advantage is that there are no restrictions on physical activities after a High Tibial Ostetomy. Patients are be able to comfortably participate in their favorite activities and even indulge high impact exercise.

Appropriate patient selection, proper osteotmy types and precise surgical techniques are essential to success of High tibial osteotomy and here comes the role of experienced surgeon like Dr. (Prof) Anil Arora, who has done large number of High Tibial Ostetomy surgical procedures with excellent results.

HTO Procedure

During this procedure, a wedge of bone is removed from the outside of the tibia, under the healthy side of the knee. When the wedge is closed, it straightens the leg. This brings the bones on the healthy side of the knee closer together and creates more space between the bones on the damaged medial, arthritic side. As a result, the knee can carry weight more evenly, easing pressure on the painful medial side to lateral side and use staple or plate to fix the osteotomy.

Candidates for High Tibial Osteotomy

High Tibial Osteotomy is most effective for active patients who are 40 to 60 years old. Good candidates have pain on only one side of the knee, and no pain under the kneecap. Knee pain should be brought on mostly by activity, as well as standing for a long period of time.

Candidates should be able to fully straighten the knee and bend it at least 90 degrees. Patients with rheumatoid arthritis are not good candidates for osteotomy.

Before & After Surgery

Usually four days of hospital admission is required for HTO surgery. Patient will be admitted one day prior to surgery for detailed workup and anesthetic check up. Twenty four hours after surgery the patient will be assisted to walk with the aid of a walker with non weight bearing assistance and made independent for toilet activities. On the fourth day the patient will be discharged from the hospital.

Patient will need physiotherapy after 6 week for regaining movement and strengthening muscle of knee joint. After 3 weeks of surgery, the patient will need to come to the hospital for stitches removal and change of cast. After that the patient will be called after 2 months for follow up and reassessment of his/her knee movement.