A retrospective clinical review was done on 54 revision hip patients. Radiological analysis examined the Gross and AAOS classifications, stem position, cement mantles, allograft and evolution (subsidence, resorption and remodelling). The Harris Hip score was used for clinical assessment. We used bone bank allograft and a polished noncollared stem LD. The follow-up period was 60.5 months (19.4-152.4), and the average age 68.5 (range: 22-85). There were 21 females and 33 males. The surgical approach was: lateral (5.56%) posterior (91.4%); trochanteric osteotomy: 25.9%; associated acetabular revision: 59.3%; previous operations: 1.9. The preoperative Harris score was 35 (28-40) and rose to 81 (50-99) postoperatively. The stem alignment was neutral (44.44%), varus (38.89%) and valgus (16.67%). The femur/stem diameter relationship was 1.8 (1.2-2.7). There were no changes in stem alignment in 94.4%. An adequate cement mantle was: proximal zone (61.1%), medium zone (27.8%) and distal zone (16.7%). The rate of any subsidence was 38.9% (progressive: 12.96%). The rate of complications was 40.7% and included periprosthetic fracture: 14.8%; superficial infection: 1.9%; deep late infection: 1.9%; dislocation: 3.7%; heterotopic ossification: 13%. The rate of new stem revision was 16.6%. The clinical and radiological success rate was 77.78%. A greater incidence of revisions has been found in stem malalignment, progressive subsidence, a Harris increase of <20 points, allograft resorption, small diameter stems and inadequate cement mantle. We recommend hard impaction and a cement mantle of at least 2 mm. Non-progressive subsidence does not increase stem loosening. The technique has been useful in recovering bone stock in a severely defective femur and achieves a stable reconstruction. The level of evidence was therapeutic study level III-2 (retrospective cohort study; see the instructions to the authors for a complete description of the levels of evidence).Résumé Une étude rétrospective a été réalisée chez 54 patients avec une analyse radiographie, selon la classification de Gross et de l'AAOS avec analyse de la position de la pièce fémorale, de l'aspect du manteau de ciment et de l'évolution de l'allogreffe (migration, résorption, remodelage). Les évaluations cliniques ont été réalisées selon le score de Harris. Nous avons utilisé une allogreffe de banque et une pièce fémorale polie sans appui sur le Merckel (LD). Le suivi a été de 60.5 mois (19.4 à 152.4), l'âge moyen de 68.5 (22 à 85). Vingt et un patients étaient de sexe féminin et 33 de sexe masculin. La voie d'abord a été latérale (5.56%), postérieure dans 91.4%. L'ostéotomie du grand trochanter a été réalisée dans 25.9%. Une révision de la cupule acétabulaire a eu lieu dans 59.3%. Tous ces patients présentaient en moyenne 1.9 intervention, le score préopératoire de Harris était de 35 (28 à 40) et postopératoire de 81 (50 à 99). La pièce fémorale était en position neutre dans 44.44%, en varus dans 38.89% et en valgus dans 16.67%. La relation entre le diamètre du f...

We made a comparative cohort study in patients suffering from tibial pseudoarthrosis, all of whom were treated by intramedullary nailing. We divided patients into two groups: one treated by intramedullary nailing only (control group) and the other by intramedullary nailing combined with pulsed

Osteonecrosis of the femoral head is a disorder that leads to collapse and osteoarthritis in young patients. This study examines the effectiveness of pulsed electromagnetic fields [PEMF] in the treatment of osteonecrosis of the head in precollapse bone stages. A retrospective evaluation was done of 51 patients including 70 hips with symptomatic osteonecrosis of the hip treated with pulsed electromagnetic fields. Criteria for inclusion in the study group were evidence of osteonecrosis and absence of collapse of the femoral head. The average follow-up was 26 months (range, 18-90). Etiologies included idiopathic (40 cases), steroid use (26) and alcohol (4). To demonstrate the existence of osteonecrosis and its evolution, magnetic resonance imaging [MRI] and plain radiography techniques were used. Results: Procedures were radiological success in 80% of cases, and no progression to collapse in 88.57% of hips. Eight of the 70 hips had radiographic progression to collapse. This study suggests that selected PEMF reduce the incidence of progression of osteonecrosis of femoral head in early stage.

There is a need to study and validate the mechanical behavior of the bone-implant total hip prosthesis and the treatment of its complications with experimental studies due to the limitations showed by numerical methods. Epoxy resin replicas of a femur (stereolithography) and a mechanical validation were performed. We studied three cases: intact femur (Case 1); non-defective femur with non-cemented LD primary stem (Case 2); and femur with a cavitary defect, short cemented stem over an impacted allograft (Case 3). The test pieces were connected to 7 strain gauges. Three assays per piece were carried out with a vertical and oblique load (load-unload curves after a sequence between 0 and 145.9 N). We measured the k coefficient (distance from the natural state of the strains) and stability of the stem (flexion-compression by strain gauges 1, 2, 5, and 7 and transversal lengthening by strain gauges 3, 4, and 6). Results of the strain gauge analysis revealed linearity of results in all cases, and more so in load than in unload. Gauge 7 (proximal) revealed shortening in all cases. Gauges 2 and 5 provided qualitatively similar data due to a significant increase in rigidity. K coefficients were obtained with a nonsignificant difference when each of the test pieces was compared with Case 2. The results were reproducible in all 7 gauges. Observation of the load-unload curves in all the test pieces assayed shows that there are no variations in the pattern of behavior (when comparing the stability of a primary stem and a stem in the simulated reconstructed femoral defect. If these reconstructions are considered theoretically appropriate for giving primary stability to the stem--a sine qua non for the success of replacement surgery--then our study is novel.