No recurrences in selected patients after curettage with cryotherapy for grade I chondrosarcomas.

BACKGROUND: The low aggressiveness of Grade I chondrosarcomas is compatible with conservative surgical treatment. QUESTIONS/PURPOSE: We asked whether combined curettage and cryotherapy would yield low rates of recurrence and whether supplemental internal fixation would retain function with low rates of complications in patients with Grade I central chondrosarcomas of the proximal humerus or distal femur. METHODS: We retrospectively reviewed 15 patients: nine women and six men with a mean age of 45 years (range, 26-70 years). All patients underwent curettage and cryosurgery through a cortical window; we replaced the window and plated the region with at least three screws beyond the curetted area. None of the patients was lost to followup, and 14 patients (93%) were reexamined by us after a minimum of 5 years (mean, 8 years; range, 5-11 years). RESULTS: There were no perioperative anesthetic, neurologic, hardware, or healing complications. None of the patients had local recurrence or metastases develop. At last followup, the Musculoskeletal Tumor Society score was 27.9 (range, 22-30) and all patients had resumed their previous activities. No complications were associated with this simplified cryotherapy technique. CONCLUSIONS: The data confirm the appropriateness of conservative surgery for central low-grade chondrosarcomas of the proximal humerus and distal femur based on a combination of intralesional curettage and cryogenic parietal sterilization. Candidates for this approach should be chosen on the basis of the affected bone site, local extension staging, and clinicopathologic grading. We recommend supplementary internal fixation. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Dual mobility cemented cups have low dislocation rates in THA revisions.

UNLABELLED: THA revisions using standard cups are at risk of dislocation (5.1% to 14.4% incidence), especially in patients over 70 years of age. Constrained tripolar cups have reduced this risk (6% incidence) but are associated with substantial loosening rates (9%). The nonconstrained dual mobility cup was designed to improve prosthetic stability (polyethylene head >or= 40 mm diameter) without increasing loosening rates by reducing wear and limiting impingement (rotation range of 108 degrees). We implanted 88 cemented dual mobility cups for THA revisions in 82 patients at high risk of dislocation. Average patient age was 72 years (range, 65-86 years). Eighty-five of the 88 hips were reviewed at 2 to 5 years followup. One patient (1.1%) had a traumatic dislocation at 2 years postoperatively. Two patients (2.3%) had asymptomatic early loosening and three patients (3.5%) had localized radiographic lucencies. These results confirm those with press-fit dual mobility cups suggesting a low dislocation rate at 5 years and a cup survival of 94.6%. At middle term followup, cemented dual mobility cup achieved better results than constrained cups in cases at risk of dislocation and recurrent loosening. LEVEL OF EVIDENCE: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Hip pain from impingement and dysplasia in patients aged 20-50 years. Workup and role for reconstruction.

In the 20-50-year age group, hip pain usually indicates dysplasia. Chronic mechanical pain is the usual pattern, although acute pain caused by avulsion or degeneration of the labrum may occur. The morphological characteristics of the dysplastic hip should be evaluated, and the link between the dysplasia and the osteoarthritis should be confirmed. Three factors indicate a favorable prognosis: joint space preservation, age younger than 40 years, and correctable femoral and acetabular abnormalities. Reconstruction is highly desirable, as it delays the need for joint replacement by 20 years. After 15 years, good outcomes are seen in 87% of patients after shelf arthroplasty and 85% after femoral varus osteotomy with or without shelf arthroplasty. Chiari acetabular osteotomy can be performed in patients with osteoarthritis but is followed by prolonged limping. Periacetabular osteotomy should be reserved for patients with moderate dysplasia and no evidence of osteoarthritis. Shelf arthroplasty and femoral osteotomy require 5-8 months off work (compared to 5 months after hip replacement surgery) but subsequently permits a far more active lifestyle. Hip replacement, which is required 20 years or more after biologic reconstruction, carries the same prognosis as first-line hip replacement (good results in 80% of patients after 15 years). Acute sharp pain related to anterior hip derangement also occurs in primary femoroacetabular impingement (FAI). The most common pattern is cam impingement, which is due to a decrease in head-neck offset and manifests as pain during flexion and adduction of the hip. Cam impingement can be corrected by anterolateral osteoplasty, which is often performed arthroscopically. Pincer-type impingement is contact between the anterior acetabular rim and the femoral neck due to retroversion of the proximal acetabulum. The imaging study strategy is discussed. Coxometry, computed tomography, and arthrography can be used. Primary FAI, which occurs as a result of geometric abnormalities, should be distinguished from secondary impingement. Causes of secondary impingement include exaggerated lumbar lordosis with pelvic tilt and to hip osteophytosis (sports or posterior hip osteoarthritis). Osteoplasty is rarely appropriate in patients with secondary impingement. The features of acute anterior hip derangement are now better defined. They can be used to guide palliative treatment, which is effective, in the medium term at least. Experience acquired over the last two decades has established the efficacy of surgery for hip dysplasia.

[Mini-invasive fixation of proximal femoral fractures: what benefit for elderly patients?]. / Ostéosynthèses mini vulnérantes du fémur proximal: quels enjeux pour les fractures du sujet agé ?

Fixation is used to treat more than two-thirds of proximal femur fractures. The mortality rate is about 25% at one year in these patients, who have an average age of about 80 years. This is mainly due to aging, but also to a gradual deterioration of general health (especially if the operation has been delayed, or after a long stay in the surgical ward) and to local complications (displacement, infection, hematoma). Two fixation devices (a sliding screw plate and a trochanteric nail) have been designed for mini-invasive treatment with fluoroscopic guidance and an incision smaller than 50 mm. The aim is to respect the soft tissues and thereby to avoid local complications, diminish pain, and facilitate early weight-bearing Hospital discharge is possible after 3 or 4 days. Laboratory experiments have shown the satisfactory resistance of the implant and bone at full weight bearing A preliminary series of 30 patients showed the feasibility of these techniques. Primary fusion was achieved in 27 cases. There were no infections and no bleeding, despite antiplatelet treatment. The techniques have now been optimized and multicenter studies are held to determine their real benefit. Fracture fusion and hip motion should be at least as good as with open surgery (90 to 96% fusions, albeit influenced by the precise position of the implants and by osteoporosis). Mortality may be slightly reduced, thanks to immediate operation, early discharge, and fewer local complications. The cost of treatment could also be significantly reduced by the shorter hospital stay. In a few years' time, mini-invasive treatment may become the standard for elderly patients with proximal femur fractures.

Can rotation osteotomy remain effective for more than ten years?

Trochanteric rotation osteotomies displace the necrotic zone of the femoral head outside the major acetabular weight-bearing zone and rotate the head anteriorly or posteriorly. Nineteen consecutive patients were selected for rotation osteotomy based on age,absence of progressive disease, and preoperative imaging studies predicting that rotation osteotomy would move the entire necrotic zone away from the acetabular roof. Factors associated with failure were head flattening and necrosis deeper than one third of the femoral head diameter. Among patient subsets with identical disease stages, outcomes seemed better after posterior rotation than after anterior rotation. Rotation osteotomies,fixed by a nail plate, can be recommended in a few selected patients with shallow necrosis involving less than one third of the femoral head diameter and without osteoarthritis or head flattening. Under these conditions, good outcomes may be achieved for 10 years or longer.

[Antibiotic-loaded bone cements: from laboratory studies clinical evaluation]. / Ciments orthopédiques aux antibiotiques: du laboratoire a la validation clinique.

Antibiotic-loaded bone cements (ALBC) were initially used empirically, both for the treatment of infected prostheses and for antibioprophylaxis. We conducted in vitro and animal studies as a prerequisite for proper clinical evaluation. We measured gentamicin diffusion from methacrylate bone cement, and found that the concentration in surrounding fluid was significantly above the minimal inhibitory concentration (MIC). We then implanted ALBC in the proximal femora of 100 ewes, in conditions close to those of total hip replacement (THR). Antibiotic concentrations in bone were above 4 x MIC for more than 6 months. We subsequently measured antibiotic concentrations in drainage fluid, blood and urine samples from 50 patients undergoing THR. Concentrations were over 20 x MIC in periprosthetic fluid, but were below the detection limit in blood after 24 hours and in urine after one week. The blood concentration was less than 1 mg/l--far below the ototoxic and nephrotoxic threshold (8 mg/l). Having established antibiotic bioavailability, we then examined the clinical efficacy of ALBC. We participated in several studies, including a French multicentric review of 342 THR procedures (direct and two-stage exchanges). ALBC was beneficial in both settings, with an 85% infection control rate. This included patients with very severe infections (multiresistant strains, severe osteolysis) treated with two-stage exchanges; and moderate infections treated by direct exchange. (This latter procedure offers fewer complications, more durable functional results, a shorter hospital stay and lower treatment costs.) We also used ALBC for antibioprophylaxis in over 2000 THR procedures, and noted no complications. This method is now being assessed in more than 200 000 cases contained in the Swedish THR Register. The experimental methods that we developed (laboratory studies, animal implantation, clinical pharmacokinetics) set the groundwork for clinical studies of gentamicin ABLC, and also allowed us to develop other ALBC formats, containing vancomycin, for example (restricted to salvage therapy). We also used these methods to evaluate antibiotic-loaded bone substitutes (calcium and carbon phosphates), designed not only to control infectious osteitis but also to replace osteolytic bone.

[Major reconstructions of the hip by allograft composite prostheses (long-term follow-up of 34 cases)]. / Reconstructions majeures de la hanche par association de prothèses et d'allogreffes (résultats à long terme de 34 prothèses composites).

Reconstruction after major resections of malignant tumors can be achieved by association of prostheses and of massive allografts. In 34 patients, we could reconstruct: the proximal femur in 21 cases, after an average resection of 180 mm, with a "composite" allograft prosthesis (with a bone graft around the stem) or a "composite and combined" allograft prosthesis (in which the femur allograft was associated with the trochanteric tendons, to facilitate the reinsertion of the glutei muscles); 10 hemipelvis in which the cup was inserted in an hemipelvic allograft; 3 proximal femurs and acetabulum (with composite cups and stems). In comparison with metallic reconstruction prostheses, composite prostheses improved function, limited complications, and increased longevity. The association of allografts and prostheses not only allows reconstructions which could be hardly achieved with only prostheses (especially for the pelvis), but also improves functional result and longevity, thanks to the biological fixation of the osseous and tendinous allografts. Considering our 15 years follow up in oncology, we have now extended these procedures to the major bone losses of the femur and pelvis following iterative revisions of standard prostheses for arthritis.

Cimento com vancomicina: farmacocinética do antibiótico na ovelha e no homem / Vancomycin-loaded cement: pharmacokinetic study in sheep and human beings

Os autores estudaram, in vivo, a farmacocinética da vancomicina associada ao cimento acrílico, implantado em ovelhas e no homem. As análises do tecido ósseo do fêmur das ovelhas, após a implantaçäo intramedular, revelaram a presença do antibiótico em três camadas da cortical, em concentraçöes bacteriologicamente eficazes durante pelo menos cinco meses. No homem, a implantaçäo de 2 ou 3g de vancomicina por dose de cimento, quando de artroplastias primárias do quadril, mostrou apreciáveis concentraçöes do antibiótico nos líquidos de exsudaçäo durante o período de drenagem, acompanhadas de baixos níveis séricos, que se anularam rapidamente. Os autores concluem que a adiçäo de vancomicina ao cimento, ortopédico representa importante recurso, tanto na profilaxia das infecçöes cirúrgicas das artroplastias primárias como nas revisöes de artroplastias infectadas.

O cimento ortopédico associado à vancomicina: comportamento mecânico e difusäo do antibiótico / Orthopedic cemet associated to vancomycin: mechanic behavior and antibiotic diffusion

Os autores relatam os resultados de suas pesquisas in vitro, a respeito da resistência à compressäo do cimento acrílico associado à vancomicina e da capacidade de difusäo do antibiótico num meio líquido (PBS). Os testes de resistência mecânica mostraram que a adiçäo de 3,0g de vancomicina näo comprometeu o comportamento mecânico do cimento, assim como a incorporaçäo do óxido de zircônio como agente opacificante e sua esterilizaçäo por raios gama. Quando mergulhado num meio líquido, o cimento com vancomicina liberou uma quatidade bacteriologicamente eficaz do antibiótico, fazendo supor que seu emprego clínico pode vir a se constituir num recurso valioso no combate às infecçöes. Os autores propoem o prosseguimento destas pesquisas, desta vez in vivo, com a finalidade de conhecer a farmacocinética deste antibiótico tanto em implantaçöes ósseas num modelo animal, como no homem, quando das artroplastias.