[Treatment of acromio-clavicular dislocations using coracoacromial ligament plasty]. / Traitement des dislocations acromio-claviculaires au moyen d'une plastie coraco clavi-acromiale (CCA).

PURPOSE: Plasty transfer using the coracoacromial ligament (Cadenat) for the treatment of acromioclavicular separation is usually too weak and too short. The authors used a reinforcement flap, made by a lateral supraclavicular detachment of the superior fibrous-capsular sheath. MATERIAL AND METHOD: Twenty-six acromioclavicular separations were radiographically studied using an axillary view. Twenty-one patients had a posterior dislocation of the lateral end of the clavicle. A pouch formed by the superior detachment was present in all cases with posterior displacement. In 19 case out of 26, this detachment was used to create a quadrangular flap with acromial support. The end of the coracoacromial ligament was attached to this long flap which provided adequate reinforcement along its entire length. RESULTS: There was a statistical correlation (p = 0.05) between the posterior component of the separation and the presence of this detachment. In the 19 reinforced plasties, no recurrence of posterior dislocation was reported, a mild undercorrection and 2 overcorrections were noted. Recurrent posterior dislocation was reported in the 7 non-reinforced coracoacromial plasties, and superior dislocation was reported twice. DISCUSSION: Posterior acromioclavicular dislocation is present in 80 per cent of cases. Diagnosis mainly uses the axillary view. It is always associated with a lateral supraclavicular detachment providing a 3 to 5 cm long downward flap which is used as a natural reinforcement for the coracoacromial ligamentoplasty.

[Evaluation of impaction on bone nail and bone plate of the pertrochanteric fracture]. / Evaluation de l'impaction sur clou-plaque des foyers de fracture pertrochanterienne.

PURPOSE OF THE STUDY: Impaction in pertrochanteric fracture sites is a well known phenomenon; the screw-plate system is designed to stabilise the fracture. Although easier to use, the risk with the nail-plate system is postoperative penetration of the nail into the joint. The present study was conducted to determine the exact conditions of the impaction, and to identify possible ways to improve the nail-plate system. MATERIAL-METHOD: The study included 129 cases of pertrochanteric fracture, excluding sub-trochanteric fractures. All fractures were fixed with a 130 degrees angulated nail-plate. In all cases, consolidation was uneventful after 8 to a 12 weeks. The anatomical type of fracture, i.e. stable or unstable, was determined according to the size of the intermediary fragment, including the trochanter minor. The displacement was measured as the difference between the length of the nail and the length of the femoral head and neck measured along the axis of the femoral neck. The parameters examined were: fracture stability degree, bony mineralisation (Singh Index), nail length, femoral neck, length nail position in the femoral head, and above all, fracture reduction. All these parameters were computerised and compared using Stat View statistics software. RESULTS: Impaction was observed in 43 per cent of cases. Among these, 25 per cent were rated as slight (1 to 5 mm), 18 per cent as moderate (over 5 mm) and 9 per cent as marked (10 to 25 mm). Impaction was associated with demineralisation of the bone tissue (p = 0.001). The anatomical classification of the fracture was not a determining factor (p = 0.19), as marked displacements were also recorded in stable fractures. A posterior and inferior position of the intramedullary nail in the femoral head is one of displacement determining factors (p = 0.004, two-sided 1 test). Valgus over-correction is the most important factor, especially when it is associated with bony demineralisation (p = 0.02) and an inadequately centred intramedullary pin (p = 0.02). Shorter the femoral neck, and shorter the nail, greater was the frequency of nail articular penetration. DISCUSSION: The risk of articular penetration therefore reaches 15 per cent in petrochanteric fractures repaired with a nail plate, set at an angle of 130 degrees. A short neck, a cervicodiaphyseal angle superior to 140 degrees, and demineralisation are the three determining parameters. Stable or unstable fracture has in fact little effect on displacement incidence, and therefore does not, on its own, warrant the use of a prosthesis in comminuted fractures. The authors compared their results to literature on progressive sliding system: the incidence of complications associated with this type of fracture treatment is identical, but the determining parameters are different. CONCLUSION: The study shows that the nail-plate is efficient and provides simple and solid fracture fixation. However, this osteosynthesis material needs to be modified in order to improve its fixation in the femoral head.

[Locked nail plate: a new treatment for unstable pertrochanteric fractures]. / Le clou plaque verrouillé: un nouveau traitement pour les fractures pertrochanteriennes instables.

PURPOSE OF THE STUDY: This work is the outcome of a preliminary study on pertrochanteric fractures which showed that impaction with simple nail plates (SNP) was lead by hypercorrection in valgus demineralization and malposition of the nail in the femoral neck. To improve anchoring of the nail in the cervico-cephalic part, the authors propose to use a locked nail-plate (LNP), an innovative device based on the addition to the normal nail plate, of a screw securing neck and nail. MECHANICAL STUDY: Mechanical flexion and compression tests carried out on 8 pairs of femurs of fresh cadavers showed comparable rigidity for the two mounting, SNP and LNP. The difference became apparent at an equivalent load through a perforation in the SNP across the femoral head and by separation of the head from the LNP without any perforation. CLINICAL STUDY: 56 patients operated on between June 1994 and June 1996 were included 30 cases could be followed. There was only one complication: one dismantling of the plate from the diaphysis. The other 29 cases consolidated within an average of 8 weeks without any complications. Locking of the nail was effective and there was never cutting out the head by the nail nor any impaction in the focus of the fracture site. This was despite the fact that, in 12 cases there was advanced demineralization, in 8 cases hypercorrection in valgus, and in 13 cases of misalignment of the nail in the neck, all three of these being recognized as causes of articular deterioration. DISCUSSION: Pertrochanteric fractures currently represent a serious public health problem for which costs are definitely going to grow in the near future. We need a method for solid osteosynthesis simple and relatively inexpensive, but which also avoids the common mechanical complications. The LNP seems to correct SNP problems. This modification represents an improvement and should be used for any unstable pertrochanteric fracture.

[Type II fractures]. / Les fractures du fémur de type II après prothèse de hanche.

Ninety-seven patients type II were in this study. There were 35 male and 53 female patient, whose average age at revision was 74,5 year old. In this group the average time to fracture after arthroplasty was 6,2 (1-20) years.The fracture was spiral in most cases (82%), but some there were transverse (18%). Loosening of the prosthesis often occured with the transverse fracture (p=0,001).Loosening occured in 30% cases before the femoral fracture : it was rarely a major, but its duration was unknown.Three different methods of treatment were used in this study: - conservative treatment was used rarely, where there was a surgical risk in incomplete or undisplaced fracture. Treatment with traction involved a prolonged stay in hospital (two months average). - internal fixation without removal of the prosthesis was used in 44% cases. Fixation with plates in 93%. Other devices were screw and cerclage wire fixation. - 47,5% cases were revised with a long stem cemented prosthesis. The most difficult was type II fracture associated with femoral loosening. The location of type II fracture may compromise the stability of prosthesis. Although there was 41% of cases whose prosthesis was not loose before fracture. In these cases, type II fracture has not compromised the stability of prosthesis: the spiral line could shape peri prosthetic mantle of cement.Healing of the fracture was obtained in most cases (97%). Thus, protetic loosening created by type II fracture has not prevented consolidation: these two events are statistically independant.The present retrospective study supports the employement of different treatment. Based on these findings, the following management of type II fracture could be recommended: - undisplaced or incomplete fracture in high risk patients, should be treated conservatively. If loosening of the prosthesis develops, revision of the arthroplasty can be done after fracture healing. - internal fixation without revision of the prosthesis should be employed if the prosthetic stem stability is not compromised. - revision of the arthroplasty should be done if loosening of the prosthesis developped before or during the type II fracture occured. Then, a long stem should be employed.

Locked intramedullary flexible osteosynthesis. A mechanical and clinical study of a new pin fixation device.

We report the use of a new method of locked intramedullary flexible osteosynthesis (LIFO) in the treatment of 118 unstable fractures of the femur and tibia. The implant utilises a set of flexible pins with a separate locking device for their proximal ends. The LIFO system proved capable of stabilising unstable fractures, and most of the complications occurred during the early testing. At follow-up, 19 of 21 femoral fractures had healed; one become infected and one showed defective callus. Of the 78 tibial shaft fractures, five failed to consolidate and five had inadequate callus. Reaming of the tibial medullary canal was never necessary. Of 28 open fractures only one became infected. The system was most difficult to use in comminuted distal fractures of the tibia, with five failures of healing in 19 cases; these cases require considerable technical proficiency. The flexibility of the system appears to promote earlier consolidation of open fractures, and normal consolidation times for fractures with interfragmentary gaps of up to 10 to 12 mm. A comparative study of callus density in tibial fractures showed a mean improvement of 50 days in cases treated by the LIFO system compared with similar cases treated by rigid nailing.