RESUMO
Austin Moore's replacement hemiarthoplasty is accepted safe procedure for early weight bearing. It is advocated for elderly patients to avoid prolonged disability, repeated operations and to improve the function. The aim of the study was determination of the durability of the hip after replacement through representing some of the important late major complications comporomising the functional end result. The study was done for 136 patients underwent for Moore's head replacement after fracture neck femur. The complications was evaluated for available 84 patients for an average 42 months follow-up period. Some late complications present in 31 patients [36%] was discussed. Successful functional outcome was significantly reduced after major complications. The incidence of complications increased with delayed operation and with prolonged follow-up period. This was related to incompatability between metal and bone and to diminished vitality of the patient. Roentogenograms was utilized in an attempting to explain the causes of failure. The mortality rate [23%] exceeded the percentage expected for this age group, and this was related to associated cardio pulmonary diseases. Late complications did not vary much with sex incidence but were related to the condition of the acetabulum existed at the time of replacement. Early local complications within the first months were superficial infection [9%] [13 cases], deep sepsis [3% [5 cases]], malposition [4% [6 cases]], dislocation [5% [7 cases]], fracture femur [8% [II cases]], deep vein thrombosis [5% [7 cases]], peroneal nerve palsy [2% [3 cases]]. More than one complication occurred in 37 patients. Late complications encountered were 8.3% loosening of the femoral stem [7 cases], 5.9% distal migration [5 cases], 8.3% interosion of the head in the acetabulum [7 cases], 8.3% deep sepsis [7 cases], 3.6% late dislocation [3 cases], 2.3% ankylosis [2 cases], 7.2% fracture femur [6 cases], 21.4% ankylosis [2 cases], 7.2% fracture femur [6 cases], 21.4% idiopathic pain [18 cases], 53.6% limited movement [45 cases], 72.6% limping [61 cases]. 4.6% sittling [39 cases], 17.8% idiopathic osteoporosis [15 cases] and 4.8% pararticular ossification [4 cases]. The major late complications were loosening, distal migration, interosion, deep sepsis, late dislocation, ankylosis and fracture femur. Combination of complications was present. Mobility was related to the preoperative range in the hip. Low seating of the prosthesis and spesis caused the high incidence of dislocation. Ten prosthesis [11.9%] was removed because of sepsis and mechanical instability. There was no correlation between deep infection and posterior approach but sepsis was related to incontenance [5.9%]. Dislocation was also related to inappropriangth and head size. Late pain was related to various causes most important was protrusion-acetabuli. Its incidence was diminished by reducing the friction wear of the articular cartilage by long partial weight hearing. Pain and defective weight bearing capacity were related to boring the head of the prosthesis in the relative unhealthy acetabulum as was noticed at the time of insertion of the prosthesis. Also, pain was related to aseptic loosening which predominated in the relatively young and active patients. Limping [72.6%] with trendelenburg gait was related to muscular insufficiency, to neck shortening, and to tendency for settling which increased with age. There was no correlation between severity of the symptoms and the radiological signs of bone resorption, prosthetic loosening, settling or wandering acetabulum. Marked bone resorption was related to latent infection or aseptic loosening which became more apparent with prolonged follow-up period. This study for complications suggest that the principle indication for prosthetic replacement should be non-union and avascular necrosis complicating high fracture neck femur. It also suggest limitation of replacement in acute displaced neck fracture because replacement provide only a temporary solution to part of the problem by early mobilization but function never equal normal and difficult complications occur even when patients were chosen with caution and the prosthesis was inserted with skill because of the specific problems related to the prosthesis [especially in the physically vigorous patients] in addition to the inherent complication in hip surgery. Subsequently, the choice of the method treatment should be highly individualised and not based on the physiological age alone. There is no need to expose all patients to the increased risk of the more hazardous revision operations. This study also suggest protection of the medial femoral cortex from compression strain during the first months [to minimise the incidence of complication and to allow for microfracture bone healing] while was achieved by long use of cane