Search

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 ≥ 40 mm diameter) without increasing loosening rates by reducing wear and limiting impingement (rotation range of 108°). 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.

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.

We evaluated the long-term fixation of 64 press-fit cemented stems of constrained total knee prostheses in 32 young patients with primary malignant bone tumours. Initial stable fixation, especially in rotation, was achieved by precise fit of the stem into the reamed endosteum, before cementation. Complementary fixation, especially in migration and rotation, was obtained by pressurised antibiotic-loaded cement. The mean age at operation was 33 years (13 to 61). No patient was lost to follow-up; 13 patients died and the 19 survivors were examined at a mean follow-up of 12.5 years (4 to 21). Standard revision press-fit cemented stems were used on the side of the joint which was not involved with tumour (26 tibial and six femoral), on this side there was no loosening or osteolysis and stem survival was 100%. On the reconstruction side, custom-made press-fit stems were used and the survival rate, with any cause for revision as an end point, was 88%, but 97% for loosening or osteolysis. This longevity is similar to that achieved at 20 years with the Charnley-Kerboull primary total hip replacement with press-fit cemented femoral components. We recommend this type of fixation when extensive reconstruction of the knee is required. It may also be suitable for older patients requiring revision of a total knee replacement or in difficult situations such as severe deformity and complex articular fractures.

Resume L’extremite superieure du femur represente la seconde plus frequente localisation des tumeurs primitives des os. Dans la majorite des cas, la reconstruction doit etre realisee par une prothese totale composite avec allogreffe combinee. L’exerese comporte l’extremite superieure du femur entouree de ses muscles, avec la terminaison de l’eventail fessier. On utilise une prothese femorale cimentee dans une allogreffe, avec une suture des tendons des fessiers du patient sur les tendons fessiers de l’allogreffe. L’extremite de la tige prothetique est cimentee dans le femur receveur. La stabilite de la prothese est assuree par une capsuloplastie tandis que la suture des tendons fessiers permet de retrouver une abduction efficace. Rarement, la tumeur est propagee a l’articulation : il faut alors pratiquer une exerese monobloc de l’extremite superieure du femur, de la capsule et du cotyle, realisee par une voie d’Ollier. La reconstruction femorale est constituee par une prothese composite combinee, tandis que le bassin est reconstruit par une allogreffe de cotyle dans lequel est cimentee une cupule. Des solutions alternatives telles que la prothese en selle sont possibles. L’extremite superieure du femur est le site le plus frequent des metastases des membres. L’osteolyse metastatique est traitee de facon palliative par une prothese de reconstruction implantee dans l’os sain apres la resection de la zone osteolytique. L’abord est realise par une trochanterotomie digastrique. Une capsuloplastie stabilise la hanche. Cette intervention simple permet la reprise rapide de l’appui complet et une radiotherapie complementaire precoce.

Resume L’etude rapporte les resultats d’une serie continue, prospective, multicentrique de 425 protheses Wallaby I ® conservant le ligament croise posterieur, posees par le groupe Guepar de 1992 a 1995. Le composant femoral de cette prothese presente des condyles asymetriques et divergents pour se rapprocher le plus possible de la cinematique du genou normal. Le plateau tibial en polyethylene est fixe. L’âge moyen des patients (70,5 ans), la repartition homme (28,3 %) et femme (71,7 %), l’etiologie (91 % d’arthrose primitive ou secondaire) et la deviation preoperatoire des genoux (65,6 % de varus > a 3° et 24 % de valgus > a 4°) etaient identiques a ceux qui sont publies dans la litterature pour ce type de prothese. Vingt-six protheses ont ete suivies moins de 1 an, 84 moins de 5 ans et 315 5 ans ou plus. Parmi les 399 genoux suivis plus de 1 an, il y a eu 4 infections (1 %) dont 3 ont necessite le changement de prothese, 3 fractures du femur toutes post-traumatiques, 2 descellements (1 global et 1 tibial) ayant necessite une reprise, 1 descellement tibial et 3 descellements rotuliens non-repris. Trois patients presentaient des douleurs anterieures du genou traitees avec succes par 2 resurfacages secondaires de la rotule et 1 section de l’aileron rotulien externe. Dix-neuf fractures de rotules (4,7 %) (dont 17 decouvertes fortuitement) constituaient la complication la plus frequente, sans retentissement fonctionnel. Le score moyen IKS genou postoperatoire etait de 90,5 points et le score moyen IKS fonction de 61,6 points. La mobilite moyenne etait de 110,5° ; 72,9 % des genoux etaient axes suivant la classification radiologique IKS, La survie de cette prothese a 8 ans (suivant Kaplan Meier) etait de 97,7 % quelle que soit la raison du changement de prothese et de 98,5 % en ne prenant comme evenement que la reprise pour descellement aseptique. Ces bons resultats corroborent ceux qui sont publies dans la litterature concernant les protheses conservant le ligament croise posterieur a plateau tibial fixe.

RESUME Plus des deux tiers des fractures du femur proximal relevent de l’osteosynthese. La mortalite, chez des patients dont l’âge moyen a l’operation est de 80 ans, est d’environ 25 %a un an. Elle est essentiellement liee au vieillissement, mais aussi au syndrome de glissement (surtout si l’intervention a ete retardee ou l’hospitalisation en chirurgie longue), et aux complications locales (demontage, infection, hematome). Deux materiels d’osteosynthese (une vis-plaque et un clou trochanterien) ont ete specialement concus pour une chirurgie mini vulnerante, realisee sous fluoroscopie par une incision de moins de 50mm : l’objectif etait de respecter des parties molles pour reduire les complications locales, de diminuer la douleur et donc de faciliter l’appui precoce, et d’autoriser la sortie vers trois a quatre jours. Apres des essais en laboratoire de resistance de l’implant et de l’os a l’appui complet, une serie preliminaire de 30 operes a ete realisee, montrant la faisabilite de ces techniques. La consolidation a ete obtenue d’emblee dans 27 cas. Il n’y a pas eu d’infection ni de saignement chez les patients sous anti agregants. La technique ayant ete optimisee, des etudes pluricentriques sont maintenant en cours pour mieux preciser les benefices de cette chirurgie : la consolidation de la fracture et la mobilite de la hanche devraient etre au moins equivalentes a celles des techniques ouvertes (90 a 96 %de consolidation, en fait limitees par la precision du positionnement de l’implant et par l’osteoporose) ; on peut esperer reduire discretement la mortalite (intervention immediate, sortie rapide, peu de complications locales) ; s’il existe des filieres d’aval, le cout des soins sera tres sensiblement diminue grâce a la brievete de l’hospitalisation. Dans quelques annees, les techniques mini vulnerantes pourraient devenir la regle dans la chirurgie des fractures du femur proximal du sujet âge.

RESUME Les ciments orthopediques aux antibiotiques ont ete proposes pour l’antibioprophylaxie des protheses articulaires et le traitement curatif des infections declarees. Il nous a semble indispensable de faire preceder les evaluations cliniques par une triple demarche : nous avons d’abord mesure l’elution de Gentamicine a partir du ciment, a l’aide d’automates, permettant de mimer le comportement d’un biomateriau implante ; puis nous avons realise, chez pres de 100 brebis, des implantations femorales de ciment aux antibiotiques, selon des techniques proches de celles de la mise en place des protheses de hanche : elles nous ont permis de constater des concentrations osseuses d’antibiotiques depassant 4 fois la CMI jusqu’a 6 mois apres l’implantation. Enfin, nous avons realise des etudes de pharmacocinetique en clinique humaine, chez 50 patients, operes d’arthroplasties totales de hanche. La concentration dans les liquides de drainage periprothetiques depassait 20 fois la CMI, mais il n’y avait pas de risque de toxicite lie a l’antibiotique, celui-ci n’etant detectable dans le sang que dans les 24 heures post operatoires. La biodisponibilite de l’antibiotique etant demontree, on pouvait alors etudier l’efficacite clinique de ce ciment. Nous avons notamment participe a une etude de 349 echanges de protheses totales de hanche infectees, et constate qu’avec le ciment aux antibiotiques on pouvait obtenir un taux de controle de l’infection d’environ 85 % dans les infections tres severes (germes resistants, osteolyse, etc.), traitees par echange en deux temps. Dans les infections moderees le ciment aux antibiotiques permettait de ne recourir a une chirurgie qu’en un seul temps operatoire, comportant moins de complications, et des resultats fonctionnels plus durables que la chirurgie en deux temps, tout en reduisant la duree d’hospitalisation et le cout des soins... Les methodes experimentales que nous avons elaborees nous ont aussi permis la mise au point d’un ciment a la Vancomycine, reserve a la chirurgie de recours. Nous les avons egalement utilisees pour l’evaluation de substituts osseux aux antibiotiques, tels que les phosphates ou les carbonates de calcium.

The functional results of standard reconstruction prostheses are impaired by instability because of poor muscular reinsertion, especially of the gluteal muscles. In 21 patients, composite hip prostheses including proximal femoral allografts were used after primary malignant tumor resection. Ten reconstructions used combined bone-tendon allografts that allowed reinsertion of the gluteal muscles to the allograft tendons. None of the 21 patients had dislocation or infection. Ten patients died within 2 years of surgery without complications requiring reoperations. The mean followup in the 11 other patients was 10 years. Eight patients had reoperation: four for loosening (two at 3 years, two at 11 and 12 years), and four had autologous graftings for nonunion of the trochanter or of the distal graft-bone interface. Evaluation of function in the 11 patients with follow-ups ranging from 4 to 15 years showed an average Musculoskeletal Tumor Society score of 77%. Satisfactory strength of the abductor muscles was achieved by reinsertion of the trochanter or by suture of the patients gluteal muscles with the combined tendon-bone allograft. At long-term, radiologically, the bony allograft showed no change in five patients, very mild resorption in five, and severe resorption in one. Stem fixation was excellent in 10 patients and fair in one. Comparison between the functional results of reconstruction prostheses versus composite prostheses showed a significant improvement with the composite prosthesis. In the authors' institution, at 10 years, the mechanical survival of composite prostheses was 81%, as compared with only 65% for reconstruction prostheses.

We used a trochanteric slide osteotomy (TSO) in 94 consecutive revision total hip arthroplasties (90 with replacement of both the cup and stem). This technique proved to be adequate for removing the components, with few complications (two minor fractures), and for implanting acetabular allografts (18%) and reinforcement devices (23%). Trochanteric union was obtained in most patients (96%), even in those with septic loosening (18/19), major femoral osteolysis (32/32), or previous trochanteric osteotomy (17/18). TSO is versatile, since it can be extended by a femoral flap (four cases) or a distal femoral window (eight cases). Despite significant bone loss, in 24% of the femora and 57% of the acetabula, favourable midterm results were achieved and only six reoperations were required, including two for trochanteric nonunion and two for loosening. It leaves the lateral femoral cortex intact so that a stem longer than 200 mm was needed in only 25% of patients. This is a considerable advantage compared with the extended trochanteric osteotomy in which the long lateral flap (12 to 14 cm) requires an average length of stem of 220 mm beyond the calcar. TSO provides an approach similar in size to the standard trochanteric osteotomy but with a rate of nonunion of 4% versus 15%. It reduces the risk of difficulties with removal of the stem, and removes the need for routine distal anchoring of long revision stems. The limited distal femoral compromise is very important in patients with a long life expectancy.

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.

Thirteen patients underwent pelvic reconstruction by massive allografts after resection of a malignant tumor (primary in 10 patients and metastatic in three patients). In 10 patients, the tumor involved the acetabulum and iliac wing and was reconstructed by a hemipelvic allograft; this was accompanied by a hip arthroplasty in nine of the patients. In three patients, a femoral metaphyseal tumor extending to the acetabulum was reconstructed by a total acetabular allograft and a composite proximal femoral allograft prosthesis. Two patients (20%) had a local recurrence, and one patient died of massive pulmonary embolism. Postoperative complications were one infection and two dislocations. At 3 years, one cup loosening and one acetabular fatigue fracture required surgery. The functional result was excellent in two patients whose gluteal muscles could be spared, good (allowing a normal family life) in six patients, fair in two patients, and poor in two patients. Seven patients had a Musculoskeletal Tumor Society rating greater than 60% of normal (the mean rating in 12 patients was 56.4%). No evidence of long-term deterioration was seen in the patients with the longest followups (7, 8, 10, and 14 years). Reconstruction of the hemipelvis with massive allografts and arthroplasty is a rewarding but demanding procedure and should be reserved for physically active patients who are in good general health and are expected to have a response to anticancer therapy. The procedure is particularly suitable for patients with primary tumors.

Resume But de l'etude Des spherules de ceramique macroporeuse de phosphate de calcium ont ete evaluees et developpees, avec le double objectif d'obtenir un substitut osseux resorbable et osteoconducteur, et un vecteur d'antibiotiques assurant une delivrance in situ de gentamicine ou de vancomycine. Le but de cette etude est de placer cet implant dans un foyer d'osteomyelite chronique experimental chez le lapin, ce qui permet de s'approcher pour la premiere fois du but de cette experimentation: le comblement des pertes de substance osseuse en milieu septique. Materiel et methode L'experience a ete menee sur 24 lapins et a comporte trois etapes en s'inspirant de la description de Norden. L'induction de l'osteomyelite a ete realisee au niveau de la metaphyse superieure du tibia en injectant un agent sclerosant puis une suspension de Staphylococcus aureus. La maturation ayant ete obtenue en trois semaines, le foyer d'osteomyelite chronique a ete aborde chirurgicalement et curete. Les animaux ont alors ete repartis en trois groupes: un groupe recevant un implant de ceramique chargee en gentamicine; un deuxieme groupe recevant un implant identique, mais sans antibiotique; un troisieme groupe ne recevant aucun implant, considere comme temoin. Les lapins ont ete sacrifies de j2 a j21 de facon a recueillir une information d'ordre cinetique. L'etude a porte sur la colonisation osseuse bacterienne, la concentration osseuse d'antibiotique et la quantite d'antibiotique restant dans l'implant. Les dosages ont ete realises par methode immuno-enzymatique. Resultats L'induction de l'osteomyelite a ete obtenue dans 21 cas sur 24 (87,5 %). La liberation de l'antibiotique a ete totale et precoce (avant le 2 e jour), mais celuici est reste present dans le compartiment intra-osseux jusqu'au 10 e jour. L'etude de la bactericidie a retrouve une efficacite therapeutique probable mais non prouvee. Conclusion Le modele d'osteomyelite experimentale de Norden chez le lapin a permis d'evaluer les traitements par voie generale, mais il est peu adapte a l'etude des biomateriaux. Le protocole experimental le plus interessant serait sans doute l'induction d'un foyer d'osteomyelite chronique chez la brebis, ce qui permettrait de se rapprocher davantage de l'experience humaine.

The low aggressiveness of Grade I chondrosarcomas is compatible with conservative surgical treatment.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.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).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.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 IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

The possibilities and limits of antibiotic cements (ACs) have been assessed by many researchers. ACs are now approved by many drug agencies, including the US Food and Drug Administration (approval in 2003), with widespread use in prophylaxis and curative treatments. Laboratory experiments have achieved satisfactory antibiotic delivery without impairing the mechanical properties of ACs. Implantation in large animals (e.g. sheep) showed an antibiotic concentration in the bone cortex four times the minimal inhibitory concentration (MIC) 6 months after implantation. Human pharmacokinetics during total hip replacement (THR) show antibiotic concentrations 20 times the MIC in drainage fluids. No toxic concentrations have been detected in blood or urine, and no allergies, toxic effects, mechanical failures or selection of resistant microorganisms have been observed. Antibioprophylaxis has been assessed in prospective studies in over 1600 cases. In data from the Scandinavian arthroplasty registers, with an exhaustive follow-up of more than 240 000 THRs, infection rate was reduced by ca. 50% (0.9% compared with 1.9%). In prostheses with severe infection, use of AC increases the infection control rate from 86% to 93% when using two-stage prosthetic exchanges. In moderate infection, a similar infection control rate (86%) was achieved either by two-stage exchange without local antibiotic or by one-stage exchange with AC; however, one-stage exchange achieved better functional results at lower cost and with reduced pain and hospital stay. Therefore, AC prophylaxis is widely used in countries with prostheses registers (Northern Europe), and use of ACs as treatment for infected prostheses is often considered as the gold standard in the EU and North America. However, AC is only an adjuvant treatment, and excision of infected and devascularised tissues as well as systemic antibiotic treatment managed by a multidisciplinary team remain the main factors of infection control.

Eighteen cases of tendon transfer for isolated radial or posterior interosseous nerve palsy have been carried out in our unit over a period of 21 years. Fifteen patients were reviewed with a mean follow-up of 9.5 years. Nine had sustained high and six low radial nerve injury. We achieved 11 excellent, two good, one fair and one bad result. The main problems were loss of power of gripping and the occurrence of radial deviation, particularly in patients with flexor carpi ulnaris transfer to the extensor digitorum communis. During this time, our technique has evolved, including changes of the tendons transferred. Our final preference is a modified Tsuge procedure, using the pronator teres to restore extension of the wrist, the flexor carpi radialis for extension of the fingers and the palmaris longus for extension of the thumb. Abduction of the thumb is restored by a tenodesis of the abductor pollicis longus to the brachioradialis. This review justifies the final policy, in particular the preservation of flexor carpi ulnaris to maintain wrist stability and flexion.

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.

Thirty chronic rotator cuff tears were repaired consecutively and evaluated prospectively using a precise anatomic description of the tear that included the rotator interval, the Constant functional score, and an assessment of the tendon state and the atrophy of the supraspinatus muscle by preoperative and postoperative magnetic resonance imaging. Early correlations (mean followup, 21.1 months) attempted to define predictive factors of the final outcome of the repair, physical factors indicative of final tendon state, and postoperative evolution of supraspinatus atrophy. Magnetic resonance imaging oblique sagittal views showed that supraspinatus atrophy correlated with the sagittal and coronal extent of the tear and represented a strong predictive factor of postoperative retearing. At followup, 15 (50%) cuffs were continuous and thick, seven (23%) were continuous but thin, and six (20%) were retorn. Two (7%) cuffs had been repaired only partly. In the group with a persistent tear, flexion strength and differential Constant score were correlated with the final tendon state with no excellent or good results, and with less than 4 kg of strength. Supraspinatus atrophy improved in 18 of the 22 postoperative continuous cuffs, but never decreased in persistent tears, although there was pain relief and functional gain.

Methods: A prospective series included 51 patients (39 females, 12 males) with a mean age of 71.3 ± 11.5 years presenting with recurrent dislocation (mean 3.3 ± 1.4). The mean number of previous THA was 1.8 ± 1.1 (1-6). A single cup design was used (Medial cup, Aston Medical, France) consisting of a stainless steel outer shell with grooves with a highly polished inner surface articulating with a mobile intermediate polyethylene component with an opening diameter smaller than the 22.2 mm femoral head. No locking ring or other means of constraint was used.

The pharmacokinetics of gentamicin were studied after total hip joint arthroplasties in 2 groups of 10 patients. The prosthesis was performed in the first group with ‘Palacos R plus gentamicin’ (normal viscosity), manufactured by Schering, and in the second group with ‘Cerafix genta R’ (low viscosity) manufactured by Ceraver-Osteal. Both cements included similar concentrations of gentamicin. Urine was collected at 12-hour intervals for 15 days after operation, and drainage fluids for 48, 72 or 108 hours. Blood samples were taken 3 and/or 5 hours after prosthesis implantation. In both cases, high concentrations of gentamicin were found in drainage fluids and urine during the early postoperative period. Mean gentamicin excretion curves were calculated by a computer-aided design program (SIAM) for the 2 cements. The release of gentamicin was biphasic in both cases, although the slow elimination phase appeared to be longer for ‘Cerafix’. In the first postoperative period, the drug had a better bioavailability during the rapid elimination phase in the case of ‘Palacos’. The calculated peak blood concentration was in the same range for both compounds. The conclusion is drawn that, in patients undergoing total hip joint arthroplasties, gentamicin concentrations reach local levels higher than the minimum inhibitory concentrations of most of the likely sensitive pathogens. However, in both cases, as blood concentrations appear to be low, patients will not be protected against systemic infections. Both cements have similar antibacterial properties but the mechanical properties of ‘Cerafix’ are the better of the two.

The authors reviewed 46 cases of resection of the upper humerus for tumor. Of the 46 tumors, 90% were malignant. The average follow-up was 5 years and the functional evaluation according to Enneking’s classification was excellent in one good in seven, fair in 15, and poor in 23. Mechanical complications occurred in 11 cases and reoperation was necessary in eight of these cases.

From this second part of the symposium, it appears that with tumors of the upper tibia it is now obviously worth trying limb salvage procedures and that primary amputation or rotationplasty should be limited to cases with a tumoral extension to the tibio peroneal neurovascular bundle. If the bundle is spared but anterior extension of the tumor demands a large excision of the extensor apparatus, knee fusion is a reliable procedure; it can be simplified by the use of an allograft (fixed by centromedullar nailing with a custom femorotibial titanium alloy nail), or by the use of an SDR (segmental defeet reconstruction) prosthesis. If the major part of the extensor apparatus can be retained, the function of the knee should be saved. Articular allograft is of great interest in primary treatment of low-grade tumors, but in high-grade tumors total knee prosthesis seems to be more reliable.