INTRODUCTION

There are several causes for a destroyed natural joint:

• anatomical deformity of the joint
• unequal load of the joint surface
• insufficient function of the tendon
• excessive load of the joint surface
• bone diseases like arthrosis or rheumatoid arthritis
• traumata

All these causes could lead to severe pain in the joint and restrict the use of it. If the joint is not used for a while or used minimally, this could lead to a natural stiffness of the joint. This also influences the capsula and tendons that are attached to the joint.

The complete recovery time after the joint replacement depends on several issues, as for instance the period during which the joint is hardly used. If this period lasted many years the recovery time will be significantly longer than if the joint replacement is carried out in an earlier stage.

This means that a joint replacement should always be considered in an early stage of joint damage. Of course factors like a good and strict following of the post-operative treatment including a good support by means of fysiotherapy influences the recovery time. The surgeon's advices should always be followed strictly, so that the implant can get fixed well to the bone. The Moje implants have a coating which stimulates bone growth towards the implant and therefore a good osteo-integration (= bone ingrowth) is secured. This is most important for the Moje implants. Too early use of the joint in a normal way or too early load on the joint could influence the recovery or the success of the implantation.

If an implant is being used as a replacement for a natural joint, this should lead to a painless use of the joint and also to a reasonable joint mobility. The expected joint mobility should allow the patient to carry out daily (work) activities and also to do sporting activities on a reasonable level. However, little restrictions after surgery could be given by the surgeon, which advice should always be followed strictly.

Normally the Moje implants show an excellent range of motion and a high pain relief.

For the Moje toe implants Dr. Dieter Werner reported a success rate, after more than 400 operated cases, of 95% of complete pain relief and 80% of mobility recovery in comparison to the other, good joints. In practice this means that the following was reported: 57° extension (= dorsi-flexion, when the toe is bending upward) and 10°plantar flexion (= when the toe is bending down). This excellent result is far above all other competitive implants and it is more than sufficient for patient's daily activities. This is the reason why the Moje implants are so successful in the joint replacement of small joints (= endoprostheses).

Surgeons are also using other alternative surgery methods. An alternative, for example, is to remove of a part of the joint (= cheilectomy), or to remove the complete joint and fixate this with a screw (= fusion or arthrodesis). Although both surgical methods could be successful to eliminate pain, the patient experiences a strong limitation of joint mobility to sometimes a complete immobility of the joint. This could be permanent and should therefore be considered very carefully. The possibilities for a solution for a patient should always be discussed with a medical professional. The optimal solution depends on several things like the age of the patient, the wishes for the joint mobility, the daily activities, the sporting activities, and possible other factors. Every possible solution should be considered carefully.

You will get a total or local anesthetic, which depends on the joint that has to be replaced and the complexity of the surgery. The surgeon will make a small incision and remove the damaged ends of the bones and cartilage. After that he will put in the ceramic ball and socket.

The Moje toe prostheses are put in without cement and fixed with a press-fit technique. This means that the toe implant is pushed (or slightly hammered) in and fixed immediately. The immobilisation time of four to six weeks immediately after surgery will create a good bone ingrowth, so that the implant will be fixed completely and stable for a long period. The immobilisation time is very important in the healing period and therefore the operated area, the forefoot, should not be weight bearing for this period. For this purpose a special shoe is given immediately after surgery, and after removing the bandages the patient should walk with crutches on the heal of the foot. The patient should be very carefully and not hit the operated toe.

For the Moje finger prostheses a small incision is also made, after which the damaged ends of the bones and cartilage are being removed and replaced by a ceramic ball and socket. This surgery can be done under local or total anesthetic, which depends on the joint that has to be replaced and the complexity of the surgery. After the surgery a small bandage is put around the operated area and/or a finger splint will be put in. After one week, when no complications have come up and the healing is going well, a small, passive range of motion during physiotherapy could be started. It is most important to follow the correct post-operative treatment precisely, to give good support to the healing process and to make sure that the mobility will be optimal after surgery.