[Mid-term behavior of the bone fixation in non-cemented Miller-Galante 1 total knee arthroplasty]. / Comportement à moyen terme de la fixation osseuse de prothèses totales de genou de Miller-Galante 1 implantées sans ciment.

PURPOSE OF THE STUDY: This retrospective work was conducted to analyze the quality of the bone-implant interface at mid-term in 45 cases treated with a non-cemented Miller-Galante 1 total knee arthroplasty. MATERIAL AND METHODS: All the protheses reviewed were implanted without cement. A patellar implant was cemented in 31.1 p. 100 of the cases. Female sex predominated in this series (77.5 p. 100) and the mean age at operation was 67 +/- 6 years. Pre- and postoperative assessment was based on the HSS score. Mean follow-up was 8.3 years (range 7-11 years). We used the method advocated by the International Knee Society to analyze lucent lines on tibial and femoral implants. Non-parametric tests were used for the statistical analysis with a significance level set at 5 p. 100. RESULTS: The mean HSS score rose from 55 +/- 12 preoperatively to 80 +/- 13 postoperatively, with 62.2 p. 100 good or excellent results at last follow-up. One re-operation was required for aseptic loosening. The femoral implant presented a lucent line in 24.4 p. 100 of the cases at the first follow-up examination only. The tibial implant presented an anterior lucent line at the second follow-up examination then a medial line at the last follow-up in 22.2 p. 100 and 26.6 p. 100 of the cases respectively. Presence of a lucent line (tibial or femoral) on at least one view was significantly correlated with activity (p=0.01) and tibial slope (p=0.0087). DISCUSSION: The disappearance of the lucent lines seen on the femoral component at the second follow-up examination was the expression of its secondary integration. Inversely, we observed an evolution in the lines observed on the tibia. This was probably the result of posterolateral impaction and anteromedial ascension micromovements of the tibial component. An excessive tibial slope was statistically related to development of lucent lines. It increased tibial translation on weight bearing and probably induced an abnormal alteration of the polyethylene. We did not observe any case of massive osteolysis of the tibial metaphysis as described in the literature for non-cemented knee arthroplasties. The screws of the Miller-Galante 1 prosthesis do not protrude from the tibial implant (which would risk generating polyethylene debris) and the pieces used (screws and implants) are all made of the same metal. CONCLUSION: The quality of primary fixation of the non-cemented Miller-Galante 1 tibial implant was not totally satisfactory at mid-term. Inversely, simple impaction of the femoral component was sufficient to ensure stable positioning.

Subacromial impingement: influence of coracoacromial arch geometry on shoulder function.

OBJECTIVE: To find correlations between radiological coracoacromial arch geometry and shoulder function in patients with subacromial impingement syndrome. PATIENTS AND METHODS: During a prospective study of the efficacy of arthroscopic subacromial decompression, we evaluated the function of the treated and contralateral shoulders using Constant's functional score and confronted the results to several radiographic parameters reflecting coracoacromial arch geometry. RESULTS: Constant's score values were low (42 +/- 15) because of pain and a low level of activity. Males had significantly higher scores than females. Constant's score was unaffected (P > 0.05) by patient age, the side, the level of activity, or the duration of symptoms, but was significantly influenced by the orientation of the acromion with respect to the scapular spine and to the vertical scapular axis. The preoperative Constant's score was significantly higher in patients with a more horizontal acromion (P = 0.01). A very tight correlation was found between the preoperative Constant's score and the angle between the acromion and scapular spine (P = 0.0003). CONCLUSION: Based on our results, we defined an open and a closed coracoacromial arch geometry. Coracoacromial arch geometry is correlated with shoulder function syndrome and can assist in the interpretation of rotator cuff impingement.

[Brain abscess following the use of skull traction with Gardner-Wells tongs]. / Abcès cérébral secondaire à l'utilisation de traction crânienne par étrier de Gardner-Wells.

Brain abscess after insertion of skull traction is a rare and serious complication. Its development is secondary to superficial infection. Adequate preventive measures have to be taken: proper sterile dressing and daily care. Signs of local irritation are not always synonymous with skull migration. When gradual loosening of the skull occurs, especially associated with superficial infection, the pins must not be tightened. The more appropriate management is to investigate for penetration of the inner cranial cave. When in doubt, repositioning the pins may be necessary, as well as establishing an aggressive treatment against cutaneous infection.

[Acetabular reconstruction using bone allograft in the revision of total hip prosthesis]. / Reconstruction cotyloïdienne par allogreffe osseuse dans les révisions de prothèse totale de hanche.

PURPOSE OF THE STUDY: Aseptic loosening of the acetabular component is the most worrying problem after hip arthroplasty. During revision surgery we prefer to rebuild a solid bony acetabulum close to the anatomy in which the implant will be cemented. On the basis of the first 48 acetabular reconstructions using deep-frozen bony allografts, we carried out a review of our results in a pathology which will surely increase in the future. MATERIAL: 48 hips were operated according to this technique. It has been possible to review 38 of them, with an average follow-up of 7.3 years (extremes 5 years, and 9.6 years). The average age of the population at the time of surgery was 63 years. Two etiologies predominated: congenital hip dislocation sequelae and primitive hip arthritis. In 10 cases of massive deterioration, a Muller's ring was used to stabilize the allograft. METHODS: The results were analyzed at 6 months, 2 years, 4 years, and at maximum follow-up, clinically, according to Merle d'Aubigné grading system. Radiologically, Ranawat's criteria were used to assess the re-centering of the reconstructed hips. The development of radiolucent lines and implants migration were also assessed. RESULTS: Clinically, the patients' comfort was always improved by pain relief. Radiologically, average acetabular upward migration of 5 mm and medialisation of 3.5 mm were observed. 24 hips presented radiolucent lines. 19 radiolucent lines were below 2 mm. 5 were greater than 2 mm and leaded to loosening. In 4 of these 5 cases of radiolucent lines, there were acetabular migrations with failure. The radiological image remained stable afterwards. In these cases there was a real loosening, necessitating further surgery. In all cases, partial resorption of the graft was observed. DISCUSSION: Study of our first 38 cases shows that bony allograft and cemented acetabulum, sometimes including an armature, is one possible solution to the problem of difficult acetabular reconstructions. However, with an average follow-up of 7.3 years, we already have 5 (13 per cent) aseptic acetabular loosening, of which one has been operated on. Radiological analysis of these does not question the allograft, but rather imperfect re-centering. Analysis of the good results, 33 (87 per cent) stable acetabulum indicates re-fixing in quasi-anatomical position, in conditions close to those of a first time arthroplasty, with the aid of perfectly stabilized bony transplants, and where contact with the receiver acetabulum is maximal. CONCLUSION: Our follow-up is one of the longest in literature. But with a migration rate already of 13 per cent, it is not yet sufficient for us to be permanently assured about the future of our patients, even if their age is greater and their activity less than those of patients having a first hip arthroplasty.

Compression of the peroneal nerve by a cyst in a seven-year-old child.

Compressions of the peroneal nerve are rare since only some sixty such cases have been described since 1921. The authors report a new observation of compression extrinsic to the peroneal nerve by a synovial cyst, the source of which was the upper fibulo-tibial joint, in a child of seven years. As far as we know, this is the youngest age found in the relevant literature. Because of a swiftly appearing painful swelling, along with complete paralysis of the peroneal nerve, an electromyogram and a nuclear magnetic resonance were performed, with a view to confirming the diagnosis and to clarifying the topography of the cyst. The removal of the latter led to the child being cured with complete recovery of the peroneal nerve within three months.

[Long-term outcome of Charnley's femoral implant. A review of 309 cases with follow-up of minimum 20 years]. / Comportement à long-terme de l'implant fémoral de Charnley. Revue de 309 dossiers avec un recul minimum de 20 ans.

PURPOSE OF THE STUDY: We evaluated the results of 309 femoral components of total hip arthroplasties performed using Charnley prosthesis and cement, by one surgeon, between January 1972 and December 1975. MATERIAL AND METHODS: Observations and measurements were based on standard pelvic X-rays. Survivorship curves were calculated to evaluate femoral component failures at twenty years of follow-up. We compared the effect of different parameters on the femoral implant loosening. RESULT: At 20 years of follow-up, 82 hips were included in the study, 227 were expelled: 109 by death, 52 by revision and 66 by loss for follow-up. Probability for death, at 20 years follow-up, was 40.7 per cent, probability for revision was 33.9 per cent, for femoral loosening was 16 per cent. The rate of aseptic femoral loosening was higher for men, with high activity and varus position of the femoral stem. Statistical analysis showed correlation between calcar resorption and femoral loosening, between polyethylene wear and calcar resorption. No directly significant correlation was established between polyethylene wear and femoral loosening. DISCUSSION AND CONCLUSION: This study confirms relations between polyethylene wear, calcar resorption and femoral loosening and underlines the influence of mechanical factors on femoral loosening. Femoral stem positioning is very important for femoral loosening. Varus position is clearly unfavourable. According to ours results, the best position is with a slight valgus.

[Reoperations of total hip prosthesis with acetabular reconstruction using bone allografts]. / Les révisions de prothèse totale de hanche par reconstruction cotyloïdienne utilisant des allogreffes osseuses.

Detachment of the acetabular segment is the most important long-term problem with total hip prostheses. We analyzed long-term outcome in our first 48 acetabular reconstructions with cryopreserved allografts. Among the 48 hips operated on with this technique, 38 were reassessed after a mean follow-up of 7 years 3 months (range 5 years-9 years 6 months). Mean age of the population at surgery was 63 years. There were two predominant etiologies: sequelae of chronic hip luxation and primary osteoarthrosis of the hip. In 10 cases with massive destruction, the Müller ring was used to stabilize the allograft. Results were assessed at 6 months, 2 years, 4 years and at longest follow-up using the Merle d'Aubigné clinical assessment scale. For the radiographic assessment, the Ranawat criteria were used to evaluate the alignment of the reconstruction. Clinically, patient comfort was improved in all cases with significant pain relief. Radiologically, mean acetabular ascention was 5 mm and mean medialization was 3.5 mm. A rim was observed in 24 cases including 19 measuring less than 2 cm. Acetabular loosening was evidenced in the 5 other cases where the rim measured more than 2 mm. In 4 of these 5 cases, the acetabulum had migrated to a new setting. The radiographic image then remained unchanged. Analysis of our 38 first cases showed that bone allografts with cimented acetabulum, sometimes with a stabilizing ring, is one of the possible solutions for difficult acetabular reconstructions. However, after a 7 years 3 months follow-up, we have had five (13%) aseptic displacements including one case requiring reoperation. In the 33 stable joints (87%) with good results reconstruction has achieved a nearly perfect anatomic position, similar to first intention arthroplasty with the use of perfectly stabilized bone grafts with a maximal acetabular surface. Our follow-up is longer than most published in the literature. However, the migration rate of 13% it is still too short to draw any conclusion concerning the long-term outcome in our patients, despite their older age and reduced physical activity compared with primary hip arthroplasty patients.

[Acetabular implant in Charnley's total arthroplasty. Review of 309 cases with a minimum of 15 years follow-up]. / L'implant cotyloïdien dans l'arthroplastie totale de Charnley. Revue de 309 dossiers avec un recul minimum de 15 ans.

PURPOSE OF THE STUDY: The aim of this study was to appreciate the long term result of 309 acetabular components of total hip arthroplasty. MATERIALS AND METHODS: All were performed using Charnley's prosthesis and cement, by one surgeon, between January 1972 and December 1975. Clinical function was graded according to Postel-Merle-d' Aubigné's scoring system (PMA score). We measured wear of polythylene using a personal method, on anteroposterior radiographs of the pelvis. Radiolucent line were appreciated by Delee and Charnley's criteria, migration by Massin's criteria. Survivorship curves were calculated with radiolucent lines, as migration, on 15 years. We compared the effect of different parameters on wear and loosening of the sockets. RESULTS: At 15 years follow-up, we found 51.5 per cent hips with the highest PMA score (18). Revision for socket loosening was 3.88 per cent, the same for dislocations. Concerning 25 per cent of the sockets, wear of polyethylene was evaluated less than 0.065 mm a year, concerning 50 per cent of them, it was evaluated less than 0.11 mm a year, at last concerning 75 per cent of them, it was evaluated less than 0.16 mm a year. No significant correlation was established between the tilt of the acetabular component and the wear of polyethylene. We observed no radiolucent lines for 60 per cent of the implants, nor migration for 83 per cent of them. Statistical analysis proved the influence of the wear on radiolucent lines and migration. DISCUSSION AND CONCLUSION: The analysis confirms a moderate wear of polyethylene during 15 years. We introduce an original method for its measurement and its formulation. This method allows a truly description of wear in long term results. This analysis confirms also that several parameters intercede on loosening; these are different if one considers radiolucent lines or migration. We do think at last, that the best positionning of the socket in the A.P. view should approach 35 degrees.

[Treatment of unstable fractures of the distal extremity of the radius by Hoffmann's external fixation. Report of 68 cases]. / Traitement des fractures instables de l'extrémité distale du radius par fixateur externe d'Hoffmann. A propos de 68 cas.

Sixty-eight fractures of the distal extremity of the radius, mostly unstable, homogeneously treated by Hoffmann's radio-metacarpal external fixation, were reviewed in terms of functional, objective and radiological criteria. Mean follow-up was 4 years, with a range of 6 months to 10 years. Overall, this treatment achieved 56% of satisfactory results, 26% moderate results and 18% poor results. Open and comminuted fractures give the worst overall results, mostly in terms of functional parameters. From this study, it is clear that external fixation is effective for the treatment of unstable fractures, as it provides good restitution of anatomical integrity of the radius, ensures better stabilization and allows immediate physiotherapy, leading to restoration of a good range of movement. Moreover, compliance with certain technical aspects such as minimal distraction, limits the disadvantages of this technique.

[Treatment of femoral fractures on a total hip prosthesis using Charnley's "long stem" prosthesis. Apropos of 18 cases]. / Traitement des fractures fémorales sur arthroplastie totale de hanche par prothèse "longue-tige" de Charnley. A propos de 18 cas.

PURPOSE OF THE STUDY: This study was performed to analyse the clinical and radiological results obtained after the treatment of femoral fractures after total hip arthroplasties by a Charnley's extra long-stem prosthesis, and to compare these results with those obtained by alternative treatments proposed by various authors. MATERIALS: 18 patients, whose mean age was 68.5 years (extremes: 45 to 86 years). Cooke and Newman fractures classification showed a clear prominence of type III. In 8 cases we found a femoral loosening, prior to the fracture, divided as follows: 4 in grade III and 4 in grade IV, using Vives classification. Type I fractures were always associated to complete femoral loosening. METHOD: Clinical results were analysed by Merle d'Aubigné's scoring system, giving a pre-fracture global score of 13.5. Post-operative radiological analysis was made on the appearance of femoral radiolucent lines and/or modification of the femoral implant. RESULTS: 17 patients were followed, with a mean of 5 years (extremes: 1 to 14 years). Consolidation was always obtained. The global mean functional results were of 15.2, with score improvement, essentially, of soreness and stability. We found 12 good and very good results, 4 poor and 1 bad. Age (< 75 years) and fracture type (II and III) appeared to be important factors influencing the functional result, contrary to the lesional mechanism. 6 non-evolutive bone-cement radiolucent lines appeared, in immediate post-operative phase. One cement-prosthesis radiolucent line appeared later, leading to loosening and rupture of the implant. We deplore 3 stem twistings, of which only one led to implant rupture. Walking with support was possible at the 5th postoperative days. DISCUSSION: Our functional results are encouraging (12 good results, i.e. 71 per cent), compared with other treatments. This technique improved the global functional score. This is due to the simultaneous treatment of the fracture and of the eventual pre-traumatic associated femoral loosening. The technique allows a quick resumption of autonomy, a short hospitalization time for these elderly patients. The main disadvantage of the orthopaedic treatment is the prolonged decubitus and the important risk of secondary loosening. Osteosynthesis by plate has the advantage of keeping a maximum of osseous stock, but delays weight bearing, favours the non union by a large loss of periosteum. It never permits the treatment of the associated loosening during the same operation. It is also at the origin of a cement weakening, while fixing the proximal screws, leading to the difficulty of placing the prosthesis. Major disadvantage of proposed method is the use of a high quantity of cement to ensure stability of the implants; but this has never had negative consequences in our study. CONCLUSION: This surgical technique seems to be a satisfying alternative to the treatment of femoral fractures on total hip arthroplasty, due to the advantages obtained. It is reserved for elderly patients. However, these findings should be taken with caution, due to our small series.

[Compression of the peroneal nerve by a synovial cyst in a 7-year-old child]. / Compression du nerf sciatique poplité externe par un kyste synovial chez un enfant de 7 ans.

PURPOSE OF THE STUDY: Compressions of the peroneal nerve by synovial cysts are rare. Sixty cases have been described since 1921. MATERIALS AND METHODS: It concerns extrinsic compression of the peroneal nerve by a synovial cyst, developed from the upper tibiofibular joint, in a seven years old child. As far as we know, this is the youngest age found in the relevant literature. Because of a swiftly appearing painful swelling, along with complete paralysis of the peroneal nerve, an electromyogram and a magnetic resonance imaging were performed, in view to confirm the diagnosis and to clarify cyst topography. RESULTS: Removal of the cyst led to healing with complete recovery of the peroneal nerve within three months. DISCUSSION: Both intraneural and extraneural cysts exist. Most authors agree that their source is the upper tibiofibular joint. In case of intraneural cysts, complete removal is sometimes impossible. It seems preferable to make a longitudinal incision in the nerve to lay the tumor flat. Indeed, everything possible should be done to find, then ligature, the pedicle which passes by the articular nerve ending of the peroneal nerve in order to avoid recurrence. Extraneural cysts are sometimes intra- or inter-muscular and create a swelling which is often palpable. It is necessary to remove the cyst carefully and to dissociate it from the nerve endings. CONCLUSION: In all cases, recurrence is not infrequent. Longer the delay before intervention is less satisfactory the recovery will be.

[Total arthroplasty, using Hardinge's approach, combined with trochanterotomy: comparative results of 200 cases]. / Arthroplastie totale de hanche par voie de Hardinge et par trochantérotomie: résultats comparés sur 200 cas.

PURPOSE OF THE STUDY: A retrospective study to compare the results obtained in our first 100 total hip prostheses inserted by Hardinge's approach and of the 100 others inserted by trochanterotomy was undertaken. MATERIAL: In the trochanterotomy group the average age was 66 years; average follow-up was 26 months. Using the Merle d'Aubigné score the initial score was 11.8. There were 65 cases of centered hip arthritis. In the Hardinge group the average age was 65 years; average follow-up was 28.3 months. The Merle d'Aubigné initial score was 12.3. There were 78 cases of centered hip arthritis. There were therefore no significant differences between the two groups and the two groups were comparable. METHODS: The quantitative variables (age, duration of operation, blood loss, blood transfusion, follow-up) were compared by Student's test. The qualitative variables (thrombo-embolic complications, dislocations, periarticular ossifications, acetabular radiolucency lines, non-union of the greater trochanter, gluteus medius palsies) were compared by the chi 2 test. RESULTS: We found no significative differences on neither the functional level nor on the orientation of the prostheses nor on the number of infectious complications between these two surgical approaches. Moreover, we found more complications such as thromboembolism and dislocations favoured by non-union of the greater trochanter in patients operated by trochanterotomy. These patients also had greater blood loss. In patients operated by Hardinge's approach, we found gluteus medius palsies (recovering secondarily); we also found a higher frequency of periarticular ossifications and a greater number of partial acetabular lines. DISCUSSION: Non-union of the greater trochanter appears in all the series of total hip arthroplasty by trochanterotomy. No technique permitted to avoid this complication which usually leads to pain and hip instability. This surgical approach is associated with higher blood loss. With Hardinge's approach there is no risk of non-union of the greater trochanter and blood loss is less important. The risk of gluteus medius palsy has to be taken in to account but digital dissection of the muscle fibers seems adequate to diminish the frequency of this complication. There is also a greater number of asymptomatic periarticular ossifications in our study but whose long term consequences are unknown. CONCLUSION: This study leads us to prefer the Hardinge approach for total hip arthroplasty. Our recent experience encourages us even because it permits osteoplastic ridge and total hip resumption. We use the trochanterotomy only for the most difficult cases specially hip arthritis secondary to severe dysplasia or congenital hip dislocations when a lowering effect of the great trochanter should also be associated.

[Fractures of the humeral shaft: role of fasciculated nailing using Hackethal's method. Apropos of 129 cases]. / Fractures de la diaphyse humérale: place de l'embrochage fasciculé selon Hackethal. A propos de 129 cas.

This retrospective study was based on 141 diaphyseal fractures of the humerus, treated by Hackethal fasciculated pinning, among 371 fractures followed up during 10 years in our department. There were six preoperative radial paralyses. The mean consolidation delay was 65 days. Six fractures did not unite and there was no sepsis. The only immediate neurological postoperative complication was a regressive cubital paralysis. 72 fractures could be followed-up with a mean of 4 years, to establish a functional result chart. 94.4 per cent of the results were good and very good, 2 shoulder stiffness and only one elbow stiffness. The displaced fractures of the humeral diaphysis on D2 to D5 zones, as well as pathological fractures are good indications for Hackethal fasciculated pinning.

[Protocol for the use of Pavlik harness in the treatment of congenital dislocation and dysplasia of the hip]. / Protocole d'utilisation du harnais de Pavlik dans le traitement de la luxation congénitale et de la dysplasie de hanche.

The authors wanted to establish a protocol of use of Pavlik's harness and check ots efficiency with as few complications as possible for the ambulatory treatment of congenital dislocation and dysplasia of the hip. To achieve this, they studied 41 hips in 37 children. They noted 2 failures of reduction, 2 failures of stabilization, 2 cases of osteochondritis and 1 transitory crural paresis. It should be noted that reduction failed and osteochondritis and crural paresis occurred in one and the same child. The other children, ie. 36 hips, had a quite favorable evolution without any stay in hospital, and reduction and stabilization were permanent. This confirms the merits of Pavlik's harness and the low rate of iatrogenic complications. The authors propose a starting, observation and termination procedure for the treatment. However, it still is difficult to define how long stabilization will take and to specify the indication for the treatment of a possible residual dysplasia.

[A case of traumatic obturator luxation of the hip in a 4-year-old child]. / Un cas de luxation obturatrice traumatique de la hanche chez une enfant de 4 ans.

The authors report a case of antero-inferior traumatic dislocation of the hip, in a four-year old child. They have reviewed the literature. If the isolated dislocation is rarely unknown, its reducing can set a problem and be impossible due to a capsulo-ligamentous interposition. This imposes the open reducing. In this case, the surgical treatment and a sufficient follow-up allow to affirm the total cure, without aftermaths.

[Ambulatory management of idiopathic scoliosis using the Lyon orthopedic treatment. 70 cases reviewed]. / Prise en charge ambulatoire des scolioses idiopathiques par le traitement orthopédique lyonnais. 70 dossiers revus.

This work tries to clarify the place which is due to the modified Lyons orthopaedic treatment of scolioses. Actually, nowadays, because of progress in surgery, some people abandon all orthopaedic treatment which caught severe progressive scolioses at the end of the growth period. The study covers 70 patients from a minimum distance of 3 years after the end of orthopaedic treatment. The treatment, in comparison with the classical Lyons treatment has two principle modifications: sequence protocol plaster then corset, purely external, not necessitizing hospitalisation or a stay in a specialised centre; and the use of resine which lightens the plaster. The results are given in angular loss as regards to the end of treatment, according to 3 factors; chronological form of the scoliosis, localization of the scoliosis, degree of the initial curvature. It emerges that in spite of the absence of hospitalisation at the beginning of the treatment, the results are comparable to those in literature (8, 19). We obtained 39 stabilizations of progression, 8 moderate aggravations without ulterior surgery, that is 67% good results. Our study confirms the high failure rate of orthopedic treatment of initial scolioses of 50 degrees and more (50%); compared to initial scolioses of 49 degrees to 20 degrees (29%); of dorsal scolioses (42%) compared to lumbar scolioses (18%); of child scolioses (40%) compared to adolescent scolioses (17%). It leads us to keep the Lyons treatment for progressive scolioses of 25 degrees to 40 degrees, from the start of puberty, or as preparation for surgical treatment.

[Legg-Perthes-Calve disease. Clinical and radiological study of 37 children (43 hips) reviewed following cicatrization of the lesions]. / Maladie de Legg-Perthes-Calve. Etude clinique et radiologique de 37 enfants soit 43 hanches revus à cicatrisation des lésions.

Results of treatment of 43 hips with primary osteochondritis lesions (Legg-Calvé-Perthes disease) are reviewed at the healing stage (mean follow up 3 1/2 years). Orthopedic treatment was applied to 27 hips and 19 good or very good results were obtained, 5 results being rated as fair and 3 as poor. Operation on 16 hips produced 8 good and very good results, 2 fair and 6 poor. The influence of various factors are studied in relation to results obtained, and the importance emphasized of the onset of epiphyseal exentration and the early performance of surgery.

[Erosion of polyethylene cupulae. Radiological study of 123 Charnley total prostheses]. / Usure des cupules en polyéthylène. Etude radiologique sur 123 prothèses totales de Charnley.

The authors have measured the distance between the centre of the femoral component and that of the acetabular component using a ten times magnification radiograph. This technique allows greater precision in the radiological assessment. 123 total hip prostheses were measured after an average follow-up of 131 months. The mean annual wear was 1.1 mm. There was a regular progression throughout the period. These results were comparable with those obtained by other authors. The wear appears to be only half as significant as in prostheses with a 32 mm femoral component (Muller type). The wear was maximal in young male patients. Patients who were overweight did not have any increased incidence of wear.