Esteban Mele, Vet.Esp.
MIPO was developed by AO in the last years according to the new philosophy of bone consolidation. The open approaches and direct osteosynthesis need big invasion. The hematoma must be preserved because it has an important effect on healing.
MIPO was originally for plates, but today it can be used with pins, external fixators, and interlocking nail system.
A lot of paper has seen better consolidations with MIPO than traditional osteosynthesis in human medicine, but few has shown these benefits in small animals. In human surgery is very common the fluoroscopy but in veterinary surgery is really uncommon.
The bone starts with the steps of consolidation after the fracture, a lot of osteoinductive factors are in the hematoma because the soft tissues must be treated with care. In veterinary surgery is very difficult to develop these techniques due to the fluoroscopy is uncommon.
Perform MIPO in tibial fractures is easier than other bones like radio, femur and humeral. The tibia doesn't have quiet (editor note: not sure that quiet is the right word here) soft tissue around the bone, the fracture and the plate must be touched. The plate could be set inside by a small incision in the skin and subcutaneous, and the first screw will be inserted by the same incision where the plate was fixed. The other screws could be put by percutaneous incisions.
In tibial fractures pins can also be used, this implant must be inserted by normograde and parapatellar incision, after achieving alignment, via bone manual traction and preservation of the length and control the deformations like valgus, varus, antecurvatum and recurvatum.
After the pin was placed by closed and normograde technique, other implant must be placed in order to control de rotational movement. When the surgeon uses pin plus plate the technique is called plate-road it is very good in many cases
The minimally invasion could be called MIS (Minimally Invasive Surgical), therefore the surgeon can fix with pins, external fixation.
Also we can use External Fixation (EF) to fix tibial or radial fractures. This implant is a really MIPO in tibia because hematoma is preserved. But it has many complications and high morbidity too.
When we try to use MIPO in radio and ulna, the surgery is more complicated than in tibial surgery specially when we haven't got fluoroscopy in the surgery room, there are quite insertions in the radio on the surface where the plate must be fixed. These anatomical structures make difficult to achieve a good alignment.
We thought about this complication and we tried to fix the ulna by caudal approach and retrograde nailing. It provides better alignment than the plate alone. After, the small approaches will be closed with only 1 or 2 sutures. The plate is inserted and fixed by 2 or 3 minimal incisions and 2 or 3 sutures. The surgery finishes when the alignment and stability are satisfactory.
When people talk about MIPO in femoral or humeral fracture, the technology is very important. Is there a fluoroscopy in the surgery room? If yes, the fragments can be reduced and the implant can be fixed with small incisions, but if there isn't a fluoroscopy in the surgery room, to perform MIPO is very difficult. The simple Rx can be used but the surgeon will take a lot of rx during the surgery. It is not easy and will depend on the surgeon experience.
We are trying to perform MIPO in femoral shaft fractures with Moss Miami® implant, this implant was developed by spin (editor note: not sure that spin is the right word here) but we have used it in humeral and femoral fractures with open approaches.
1. Alonso A, Appenzeller P, Cole A, Frenk R. 2003. Less invasive stabilizaction system for the tibia. Injury. 34:16-29 (Suppl 1).
2. Babst R, Simoni U, Dieter R, Frigg A. 2003. Locking compression plate a new AO principle. Injury. 34:31-42 (Suppl 2).
3. Cabassu JP 2001. Elastic plate osteosynthesis of femoral shaft fractures in young dogs. Veterinary Compendium Orthopedics Traumatology.14: 40-45.
4. Frigg R, Appenzeller PA, Chistensen R. 2001. The development of the distal femur. Less Invasive Stabilizaction System (LISS). Injury. 32:24-31.
5. Keller M, Voss K. 2002. Unilock: Applications in small animals. AO Dialogue.15: 20-21.
6. Perren SM, Matter P. 2003. Evolución of AO philosophy. AO Dialogue Issue I. June.16: 1-3
7. Ventura H, Mele E, Corigliano. 2005. Osteosíntesis mínimamente invasiva (MIPO). Presentación de 10 casos clínicos. In: Congreso nacional de AVEACA. Buenos Aires Argentina.