At the  Warren Animal Clinic we are now pleased to be able to offer this new modification of the TTA (tibial tuberosity advancement) procedure. For almost 10 years the Tightrope procedure has addressed most of our ACL repairs with outstanding results. Since all breeds differ in size and function there are occasions where a TTA procedure is indicated. The MMP produces the same great results as tightrope, just a another way to accomplish it according to individual patient needs. We are excited that the MMP is minimally invasive also.

Like the TTA and the TTO the overall aim of the procedure is to get the tibial plateau at 90 degrees to the patellar tendon. In simple terms this makes the patellar tendon act in a similar way to the ACL/CCL.

 

The MMP procedure is based on a technique developed almost 50 years ago for use in human knees by Dr Maquet, a Belgian orthopedic surgeon. The surgery works by redirecting the force generated by the large quadriceps muscles to compensate for the failed cruciate ligament. This is achieved by freeing,and moving forward, the part of the tibia (the tibial tuberosity) attached to the quadriceps muscle. The void is stabilized using a modern orthopedic implant material called OrthoFoam. Thus the name Modified Maguet Procedure (MMP).

The porous titanium OrthoFoam promotes rapid bone in growth and healing. Capillaries penetrate the OrthoFoam quickly. This is key to the reduced convalescence and minimal pain seen with MMP surgery. Successful recovery after knee surgery, no matter which procedure has been used, requires a period of controlled activity. Compared to other procedures, MMP causes less discomfort and while a comfortable, pain-free patient is obviously a good thing, many dogs are tempted to use the operated leg too much, too soon. No matter how comfortable and confident your pet is feeling in the days after their MMP operation, it is absolutely essential that running, jumping, and general “rough and tumble” with other pets is avoided for the first 6 weeks or so.

The bone must be given time to heal adequately and too much strain placed on the osteotomy too early can result in stress fracture or implant failure and while this is rarely catastrophic, the ensuing complication may be painful and will certainly delay the recovery. The recovery period is outlined below.

First 2 weeks

Bandages are not used following MMP because it is important that your pet is able to flex and extend the operated knee freely right from day one. The skin sutures are removed 10 to 14 days after surgery.

During the first 14 days

Your dog should be encouraged to take frequent short leash walks 5-10 minutes, six or eight times daily is a good starting point. It is important that the operated knee joint is returned to use as quickly as possible . Concentrate on walking slowly as this will encourage the patient to use the leg. Ideally, your dog should go outside ON A LEASH to urinate and deficate during the first two weeks after surgery. Do not swim the dog. No other exercise is recommended for the first 14 days – it is important to not let your pet loose to run freely in the house, particularly up and down stairs.

Third and fourth weeks

The amount of activity can now be gradually increased but it is essential that the patient is still not allowed off the leash. Leash walks can be longer and faster though you need to take care to ensure that the patient continues to use the operated limb confidently at every step.

 

Fifth and sixth weeks

Check X rays are scheduled for the end of week four and these should confirm that the osteotomy is healing well. Bear in mind that although bone healing and remodelling will be progressing nicely, full strength will not be established for several more weeks. At this stage, the patient will be capable of frequent lengthy (30 minutes or more) leash walks and we will soon be introducing some free running activity. The key to success is a program of gradually increasing activity. At first,the patient can be allowed off the leash towards the end of the last walk of the day – choose a quiet area with a good surface – a short cut grassy park is ideal – without dogs or other distractions that might encourage your pet to do too much too soon. Five minutes is enough for the first day off the leash. Subsequently, the amount of free running play and exercise can be increased gradually back towards normal pre-injury levels. Most dogs will be capable of full, unrestricted athletic activity within 12 weeks of their MMP operation. Some residual low grade stiffness and lameness may still be seen at twelve weeks but this will resolve completely over the subsequent month or two as the patient regains full fitness and muscle tone.