The cases of twenty patients who had an arthrodesis in which an intramedullary nail was used for stabilization were reviewed at an average follow-up of six years. The predominant indications were infection after total knee arthroplasty and post-traumatic pain and instability. Other indications included aseptic loosening of the components of a total knee arthroplasty, reconstruction after resection of a giant-cell tumor, non-union of a fracture of the distal part of the femur or the proximal part of the tibia, and failed external-compression arthrodesis. Success was achieved in seventeen patients (85 per cent), and functional stability immediately postoperatively was gained in all twenty. Of the three patients in whom the arthrodesis failed, all had sustained an intraoperative fracture, and infection eventually developed. Of the twelve nails that were secured to the greater trochanter with a loop of stainless-steel wire, none showed evidence of proximal migration. Of the eight nails that were not thus secured, two migrated proximally, necessitating removal of the nail. Two drawbacks to this operation are the long duration and the large amount of blood that is lost. The major advantage is that a high percentage of patients have progression to a stable fusion despite serious problems. Furthermore, all but seven patients (including the six who had a tumor or who had sustained an intraoperative fracture) were able to bear full weight by the second postoperative week. Only a few patients needed an external support for walking.

Arthrodesis of the knee with an intramedullary nail.

We sought to assess the clinical effectiveness of a new plate design which offers improved biological and biomechanical features, the limited contact dynamic compression (LCDC) plate. We analysed 114 LCDC plates applied consecutively for upper extremity fractures or reconstruction in 94 patients. Three patients were lost to follow-up, leaving 111 plates in 91 patients followed to definitive fracture/osteotomy outcome. Thirty-seven plates were applied for reconstruction in 35 patients, including 11 where standard implants had failed. Fifty-six patients had 74 plates applied for acute fractures including 12 open fractures, 23 multiply injured patients, 26 patients with concomitant fractures and seven associated neurovascular injuries. All patients were followed to definitive outcome. Union was achieved at an average of 10.7 weeks in 105 platings, while three delayed unions eventually united without further intervention, an overall union rate of 108/111, or 97.3 per cent. There were no mechanical failures of the plates or screws. In this large series a union rate of 97.3 per cent with no implant failures confirms its clinical application for traumatic and reconstructive problems in this area. Improved contouring, easier screw placement, decreased interference with cortical bone blood flow and excellent union rates are definite short-term advantages. Theoretical long-term benefits of decreased stress-shielding and lower refracture rates will require longer follow up.

The application of the limited contact dynamic compression plate in the upper extremity: an analysis of 114 consecutive cases

Compression arthrodesis of the knee was first described by Key (1932) and interest in the method was revived by Charnley (1948) whose clinical experiences led him to believe that osseous union could be present four weeks after operation. This has been doubted and it is generally believed that the best that can be expected at this stage is an extremely close fibrous union which later becomes converted into bone. The early rigidity of this arthrodesis can be explained mechanically because the closely applied flat surfaces of the arthrodesis, even

Compression arthrodesis of the knee; a clinical and histological study.

The conclusion from the above clinical and experimental presentation is that stabilization by using external fixation in problematic cases is the method of choice because the risk of infection is better than by using the standard methods of plating and nailing. Using external fixation based on the tubular system of ASIF we can achieve rigid stability. Correct application allows early mobilization ensuring alignment even in bone defects. This method of treatment also facilitates the care of wounds. Our experimental and clinical information provides us with the opportunity to offer a systematic classification of each individual type of external fixation and its merits, as described above in types I, II, and III and its application in different situations. Our clinical experience also shows that external fixation has greatly reduced the risk of amputation in these problematic cases, but it has not solved all the problems associated with the primary injury. The advantage of the three-dimensional external fixation type III can also be seen in the case of arthrodesis of the knee joint. Here there is a better neutralization of the bending moment, than by using type II. Finally we would like to emphasize that the external fixation is not the panacea for every problematic case and each surgeon should be well aware of its methodical and correct application, as abuse of external fixation may lead to secondary complications.

External fixation. Classification and indications.

https://www.tandfonline.com/doi/pdf/10.3109/ort.1972.43.suppl-140.01

Tibial fractures treated by AO compression osteosynthesis. Experiences from a five year material.

1. The technique of compression-arthrodesis of the knee joint is described. 2. Fifteen consecutive cases are reported in which clinical union was detected at the first inspection from twelve days to six weeks after operation. By this method the total period of disability is reduced to three months. 3. Three mechanical factors which might be responsible for this very early clinical union are examined: compression is believed to be the main factor, although fixation is also important. 4. A fallacy is exposed in the use of bone grafts for arthrodesis of the knee; the graft is less osteogenic than the substance of the bones which form the joint, and it provides inefficient internal fixation. 5. A theory is suggested that compression, even in the presence of slight movement, acts by producing a fixed "hinge" without shearing movement; at this point a bridgehead of flexible osteoid tissue is established in which ossification inevitably takes place despite slight bending movement. 6. A second theory is suggested that high compression forces stimulate early union by liberating bone salts at points of maximum pressure through the action of osteoclasts, and that the local excess of bone salts is redeposited under cellular activity within a range of a few millimetres where there is no pressure.

John C. Charnley

Papers

Positive pressure in arthrodesis of the knee joint