In recent years there has been some revolutionary advances in joint replacement surgery. Till recently the joints, which were commonly replaced were that of knee joints and hip joints. Now the other parts of body can also be replaced as that of shoulder, elbow, wrist, finger and ankle joints. The revolutionary materials and cementing is done which are more long lasting and body friendly.

It has been observed that Asian bones are not only small but also more fragile as compared to European and American bones. This discovery has led to better joints, which are better replicates of original joints and their life span has also increased to 20 to 25 years.

The other major development in orthopedic surgery has taken place in knee surgery, which is called uni-compartmental knee replacement. Now the recovery has become more swift and painless due to better cementing techniques. This surgery is more useful for younger generation because now surgery is also done without using binding materials. The screws and other press fit methods ensure further replacements and adjustments with less difficulty and pain.

In case of hip replacement surgery the method called hybrid hip replacement techniques is becoming common with higher success rates. The younger generation is showing higher success rate. Here the hip joint cup is fixed without cement through screws. The femoral component or the part of bone only needs cementing material. This technique has increased the life of joints and reduced post surgery recovery period.

There has been phenomenal improvement in cementing methods for joining the joints. The material used for cementing is poly methyl metha crylate. It has been observed that if cementing is done properly then life of joints also increase and can last for life long. These days better quality cement guns are used. For mixing the material, vacuum mixers with pressurization techniques are used.

MOBILE BEARING TOTAL KNEE REPLACEMENT:

TKR represents a major advance in the management of severe, crippling arthritis. More than 300,000 patients undergo TKR each year in USA alone. Although the procedure is among one of the most successful in Orthopaedic Surgery, the debate continues as to the best treatment option regarding TKR- fixed bearing or mobile bearing prostheses. Many of the fixed-bearing prosthetic designs have performed well at 10- to 20-years follow-up, but polyethylene wear, restricted joint mobility & patello-femoral complications have been reported. A newer approach to TKR (Mobile Bearing Knees) has been introduced in an attempt to reduced some of these problems. The Mobile Bearing Knees (MBK) may solve the fundamental mechanical problem of allowing joint mobility while minimising the wear of polyethylene bearings.

The concept of MBK is based on the fact that there is mobility at the tibial bearing interface on movement. The congruent bearing contact reduces stresses with the polyethylene (plastic) hence minimising the potential for wear & damage to the bearing surfaces.

MBK facilitate normal physiological movement of the knee while maintaining congruency through the gait cycle. This protects the polyethylene bearing from wear & damage, whilst interaction between the polycentric design of the femoral component & tibial bearing permits near normal kinematic function. Hence, MBK not only increases the life span/survival of the artificial joint but allows the patients to fold their knees more to near normal, as compared to the conventional TKR.

Contemporary TKR which is currently one of the most frequently performed othopaedic surgical procedures, has developed over the past 30 years. Although the goal of TKR is simple, the means of accomplishment are complex as surgeons & engineers strive to design a prosthetic joint that will function like a human knee. Success of the procedure not only is dependent on the skills of the surgeon & his team, but is also coupled with the design of the implant & instrumentation. A scientific sound design must be complemented by easily used instruments & a technique that assumes accuracy & reproducibility.

Approximately 1000 consecutive mobile bearing-TKR operated on during the last 15 years yielded survivorship of 92.4%.

The success of mobile bearings in TKR is recognized by surgeons worldwide, & virtually all major manufacturers are presently testing a mobile-bearing design.