[Early aseptic loosening of cemented cup in metal-on-metal total hip arthroplasties]. / Echec par descellement aseptique précoce de la cupule acétabulaire cimentée de prothèses totales de hanche à couple de frottement métal-métal.

PURPOSE OF THE STUDY: The aim of this study was to report cases of acetabular failure of metal-on-metal total hip arthroplasties using cemented cups with a metal-metal bearing. MATERIAL AND METHODS: From 1997 to 1999, 137 patients underwent total hip arthroplasty with a 28-mm head and a metal-metal (Metasul) bearing. At mean follow-up of three years eight months (range 2-6 years), three patients had died and thirteen were lost to follow-up or had less than 2 years follow-up. The analysis thus included 118 patients (122 hips) 67 women and 51 men (mean age 61 years). The same transgluteal approach with two cemented implants (Palacos gentamycine) was used in all patients. The Postel-Merle-d'Aubigné score was used for clinical assessment with search for lucent lines in the Delee and Charnley zones and cup migration on the standard x-rays. Actuarial survival curves were drawn using revision and failure as the end events. RESULTS: In this series, there were no cases of dislocation or infection but there were five revisions for aseptic cup loosening: one at two years, two at four years, and two at five years. Among the remaining 117 implants, outcome was clinically very good in 101, good in 10 and fair in 6. Radiologically, there were no cases of femoral lucent lines, migration or osteolysis. For the cup, a lucent line measuring less than 1 mm and stable was observed in 81 hips. A progressive lucent line was observed in 18 hips with 11 showing signs of probable loosening. The five-year survival using surgical revision as the endpoint was 94%. Using cup failure (revision and progressive line), it was 80%. Revisions and radiographically probable loosenings were statistically more significant in small cups measuring 44 and 46 mm. DISCUSSION: In this series, cemented metal-on-metal bearings showed a rate of failure greater than observed in metal-polyethylene implants and metal-on-metal implants using a press fit cup. Other series using a metal-on-metal bearing with a cemented cup have found the same trend. CONCLUSION: We have discontinued this type of implant and recommend avoiding direct cementing of the polyethylene-metasul cup on the bone for total hip arthroplasty. The metal-on-metal bearing can still be used, but without cementing the cup.

[The cemented Müller straight stem total hip prosthesis with polyethylene cup and 28 mm head: ten-year results]. / Résultats à 10 ans de la prothèse totale de hanche cimentée autoblocante de Müller avec cupule en polyéthylène en diamètre de 28 mm.

PURPOSE OF THE STUDY: The purpose of this study was to evaluate the 10-year results of the cemented Müller straight stem total hip prosthesis with polyethylene cup and 28 mm head. MATERIAL AND METHOD: From May 1988 to May 1990, 187 cemented prostheses (second-generation technique) were implanted via a transgluteal approach for degenerative hip disease. A Protasul 10 straight stem with a 28 mm modular head and a gamma ray sterilized polyethylene cup was used in all cases. At ten years, the follow-up of the 187 implants was: 60 implants in deceased patients, 24 implants in patients contacted by telephone (all with implants in place), 90 implants in 82 patients seen for review. The series thus included 40 women and 42 men, mean age 65 years. The clinical outcome was assessed with the Postel Merle d'Aubigné (PMA) score. Radiographic assessment noted lucent lines, granulomas, implant migration, polyethylene wear, and ossifications. Survival curves were established with the actuarial method. RESULTS: Among the 187 implants, two patients required revision: one for sepsis and the other for posttraumatic dislocation. Among the 82 patients reviewed at 10 year, the PMA score was 16.8 (92% good and very good results). Radiographically, assessment of the acetabular component demonstrated three probable and one certain loosening, four cases of polyethylene wear greater than 2 mm. At the femoral level, osteolysis was noted in zones 1, 3, and 7 and rarified bone in zone 7 in four patients. Linear penetration of the stem into the cup was 0.09 mm/yr, corresponding to a volumetric wear of 55, 35 mm3/year. Brooker grade 3 ossification was observed in 27% of men and 14% of women. DISCUSSION: The clinical results were comparable to other series of cemented prostheses. At ten years, acetabular loosening was more frequent with active radiolucent lines present from the fifth year. It would thus appear that better results could be achieved by optimizing the bearing. Furthermore, there was no parallelism between the clinical and anatomic observations, cup loosening and femoral osteolysis were well tolerated. The prevention of ossification appears to be an important point, particularly in men.

Monitoring of polyethylene wear in nonmetal-backed acetubular cups by digitized anteroposterior pelvic radiography.

The aim of this study was to assess polyethylene wear in a total hip prosthesis by digitized radiography of the whole pelvis in the anteroposterior (AP) plane. The three-dimensional (3-D) pose of the nonmetal-backed acetubular cup, materialized by its metal ring and the femoral head made of metal or ceramic, was estimated using iterative algebraic algorithms with inner bias correction and bootstrapping for variance reduction. Points of interest were obtained by maximizing the correlation between sampled density profiles and 3-D geometric models degraded by the modulation transfer function (MTF) of the radiographic system and the film scanner. The error in the maximal correlation estimate were inferred from noise power spectra (NPS) and allowed the calculation of the point covariance matrix. Both NPS and MTF were modeled for each stage and estimated using least-square fitting of the overall NPS model to the autospectral density function calculated in stationary regions. Comparison of the radiographic time series was made possible by the high accuracy level and 3-D matching from the cup orientation. The feasibility of the full 3-D measurement, the assumption of negligible lateral wear and its influence on AP wear are discussed on simulated and real radiographic data.

Computed tomographic study of the posterior condylar angle in arthritic knees: its use in the rotational positioning of the femoral implant of total knee prostheses.

The epicondylar axis is a reliable reference to check the rotation of the femoral implant in total knee prostheses (TKPs). However, during the operation it seems easier to use the posterior condylar axis as a landmark. The angle between these two axes is called the posterior condylar angle (PCA). The aim of this study was to measure the PCA in arthritic knees to assess the reliability of the posterior condylar axis as a reference for the control of the rotation of the femoral implant and to look for correlation with other radiological measurements. This prospective study consisted of 103 arthritic knees (81 varus, 22 valgus) before a TKP had been done in 103 patients (75 women, 28 men). The assessment of the PCA was made by computed tomographic scanning (CT). The HKA, HKS and HKT angles were measured on the pangonogram. The posterior condylar axis was internally rotated with respect to the epicondylar axis. The average value for all the patients was 2.65 degrees degrees with a range from 0 degrees to 7 degrees. The PCA was significantly increased in the valgus knees. There was no correlation between the angles on the pangonogram and the posterior condylar axis. While the preoperative assessment of the PCA by CT scanning is reliable, the results obtained indicate the marked variability in its value. If one wishes to use the posterior condylar axis as a guide for rotation, it is therefore necessary to assess the PCA for each patient using adjustable jigs according to the value obtained. No measurement on standard radiographs allowed an extrapolation of the value of the PCA, and CT scanning seems to be the preferable radiological examination.

[Xenograft-related complications after filling valgus open wedge tibial osteotomy defects]. / Complications en rapport avec l'utilisation d'une xénogreffe (Lubboc) pour le comblement de l'ouverture médiale dans l'ostéotomie tibiale de valgisation.

PURPOSE OF THE STUDY: The purpose of this study was to assess clinical tolerance and radiological and histological changes observed after using a safe bovine xenograft (Lubboc) to fill open wedge defects after tibial osteotomy for valgisation in patients with medial femoro-tibial degeneration. MATERIAL AND METHODS: Thirty-one valgus open wedge tibial osteotomies were filled with a xenograft (Lubboc) and fixed with an epiphyseal plate in 16 women and 13 men, mean age 55 years two months. All patients had medial femorotibial degeneration with genu varum. Mean varus deviation was 6 degrees. RESULTS: At two years six months follow-up, five patients had developed a local complication: three cases of non-infected discharge and two infections. Among the other 26 cases, the radiographic evolution of the xenograft was similar to that described for autologous grafts but for seven cases, a lucent line persisted, isolating the graft. A biopsy was obtained in fifteen patients during the material removal procedure. Cell infiltration was absent in nine grafts. DISCUSSION: In light of the large number of local complications and the unpredictable nature of the radiological and histological outcome xenografting should be discontinued.

Technical aspects: the patellar side.

Complications of patellar resurfacing depend largely on technique. Patellar preparation is only one element of the technique. Correct implantation can be obtained when soft tissues are equilibrated previously to sectioning, patellar cut is parallel to the prosthetic trochlea, the patellar is centered in relation to the center of the trochlea, and when thickness and height of the patella are maintained.

[Bone reconstruction, leg length discrepancy, and dislocation rate in 52 Wagner revision total hip arthroplasties at 44-month follow-up]. / Reconstruction osseuse, inégalité de longueur des membres, taux de luxation de 52 prothèses de Wagner, en révision d'arthroplasties totales de hanche au recul moyen de 44 mois.

PURPOSE OF THE STUDY: The primary and secondary stability of a revision implant is highly compromised in cases with important loss of bone stock from the proximal femoral after severe femoral loosening. Several methods using implants with or without cement have been proposed for reconstruction after femoral bone loss. The purpose of this study was to analyze mid-term clinical and radiological outcome with the Wagner prosthesis for revision surgery. MATERIAL AND METHODS: Fifty-two cases of aseptic femoral loosening were treated with this method in 36 women and 14 men, mean age 70 years (range 32-92 years). None of the patients was lost to follow-up; five who died after 18 months were retained for analysis. Mean follow-up was 44 months (range 18-88 months). The mean preoperative Postel Merle d'Aubigné (PMA) score was 10.5 +/- 0.4. These patients had major bone loss (5 grade II, 24 grade III, 23 grade IV in the SOFCOT classification). The transfemoral access was used in 17 cases and bone grafts in 32. Clinical outcome was assessed with the PMA score and leg length discrepancy was measured. Radiographically, stability was assessed by measuring stem impaction and progression of radiolucent lines. RESULTS: The overall functional score was significantly improved from 10.5 +/- 0.4 preoperatively to 14.6 +/- 0.5 (p<0.001). All items on the score improved but pain relief was the most notable. Improvement in the gait score was limited due to persistent limping in 39 patients. Leg length discrepancies were found in 8 patients with 6 shortenings and 2 lengthenings. The clinical situation remained stable after one year. The implant remained stable in 48 patients (92 p. 100) and stem impaction was observed in 4 before 12 months. Two of these cases required a second revision. Metaphyseal reconstruction was observed in 42 patients (81 p. 100), including 24 (46 p. 100) who exhibited homogeneous reconstruction with trabeculation. The reconstruction did not progress further after 18 months postoperatively. Complications included four dislocations and five revision procedures (three for cup loosening, two for femoral pivot instability). DISCUSSION: The functional outcome was similar to results reported in the literature, including the high frequency of limping that was caused by various factors (valgus prosthesis neck, leg length discrepancy, muscle deficits). Leg length discrepancies resulted from defective positioning or impaction at loading. Standard radiographic series allowed an assessment of stem impaction. Our low rate could be due to delayed weight bearing. La reconstruction of bone loss did not progress after 18 months and was independent of bone grafting, route of access, and the initial degree of loosening. The high frequency of dislocations with this type of implant can be prevented by horizontalization of the acetabulum and use of anti-dislocation inserts at the first intention revision. CONCLUSION: Our results with the Wagner prosthesis are satisfactory both clinically and radiographically. The two drawbacks of this implant (limping and dislocation), partly due to the design of the femoral stem, have led us to study a new implant that preserves good distal anchoring and optimizes the proximal biomechanics of the hip joint.

Intraosseous xanthoma without lipid disorders. Case-report and literature review.

A case of intraosseous xanthoma in a patient with a normal lipid profile is reported. Hyperlipidemia is present in most patients with xanthomas. Intraosseous xanthomas are rare, particularly in normolipidemic patients, in whom the presenting symptom is pain without skin lesions. A lytic lesion with a rim of sclerosis is seen on radiographs. Histology shows foam cells, giant cells, and fibrosis. Intraosseous xanthoma is a benign tumor, and other diagnoses must be ruled out (histiocytosis X, Erdheim Chester disease, clear cell carcinoma metastasis). Surgical excision of the lesion is the elective treatment.

Study of the variations in length of the anterior cruciate ligament during flexion of the knee: use of a 3D model reconstructed from MRI sections.

The aim of this study is to suggest an anatomic study of the modifications of the length of the anterior cruciate ligament (ACL) and its bundles during flexion with the aid of a 3D computerized model of the knee in a living subject. The method of evaluation suggested is a 3D computerized reconstruction based on MRI sections, reproducing the movement of flexion of the knee from 0 to 75 degrees. Twenty-one sections were made for each of the 13 positions of flexion. The reconstruction of Delaunay and the realignment of each position provided a 3D model which allowed monitoring of a bony point during the movement. By knowing the relative displacement of the ligamentous attachments it was possible to define the biometry of the ligament by calculating the length of the bundles of the ACL in each position and to demonstrate the variations in length during the movement. The mean length of the ligament was 3.4 mm. The anteromedial bundle was longer by 30% compared with the other two bundles. During flexion the anteromedial bundle was not much modified (this feature seems to provide a reference position for a ligamentoplasty), the posterolateral bundle became taut after 30 degrees, and the intermediate bundle relaxed from the beginning of movement. Based on the data from the literature, this method allows an anatomic approach to the ACL, bundle by bundle, during flexion movement.

[Study of the posterior cruciate ligament using a 3D computer model: ligament biometry during flexion, application to surgical replacement of the ligament]. / Etude du ligament croisé postérieur à l'aide d'un modèle 3D informatique: biométrie ligamentaire lors de la flexion, application au remplacement chirurgical du ligament.

We have developed a 3D computed model of the knee joint, constructed from MRI acquisitions in a living individual. We have used this model to perform an anatomic and biometric study of the posterior cruciate ligament (PCL) during flexion, and an assessment of the optimal location for an intraarticular graft. The method used a 3D computed model constructed from MRI acquisitions during knee flexion (0 to 75 degrees). The range of motion was limited by a positioning device. We took 13 acquisitions from 0 to 75 degrees of flexion. Each acquisition consisted of 21 sagittal cross sections of 3 mm slice thickness. We used the Delaunay reconstruction to obtain a 3D geometric model. A matching process to fix one part of the articulation during the movement, allows for the kinematic analysis of the tibia relative to the fixed femur. This model allows to follow the displacement of a bone point during knee flexion. Knowing the relative displacement of the bone insertions of the ligament, it may be possible to determine the length of the PCL and its bands, to evaluate the length variation during movement, and to determine the optimal location for the insertion of an intraarticular graft, that would lead to the least stretch during flexion. It was found that the mean length of the PCL was 30.2 mm, with the posterior band being 30% longer than the anterior band. During flexion the posterior band increases its length by 10% at 50 degrees flexion, and by 20% at 75 degrees flexion. The anterior band stretches more, to reach 40% elongation at 75 degrees flexion. The best position for insertion of a graft seems to be in the posterolateral portion of the anatomic tibial insertion, and posterior to the anatomic femoral insertion. This method confirms the data in the literature, states precisely the length of the different bands of the PCL, and specifies the points of insertion for a graft, which lead to the least variation in length during flexion.

[Failure of the polyethylene cups directly implanted into bone. A study of 32 Freeman cups after 9 years of followup (6-12 years)]. / Echec des cupules en polyéthylène implantées directement sur l'os. Etude de 32 cupules de Freeman à 9 ans de recul (6-12 ans).

PURPOSE OF THE STUDY: A clinical and radiological assessment was performed on 32 Freeman polyethylene uncemented acetabular cups, at an average of 9 years follow up. This study was dedicated to analyze polyethylene bone direct fixation. MATERIAL: Between 1984 and 1988, 30 patients were operated for 32 total hip prostheses. Mean age of the population at the time of surgery was 66 years. In all cases the prosthesis was a cemented Müller femoral stem with a Freeman uncemented cup. The acetabular component was made with polyethylene with three pegs fitted with an offset hemispheric cup. METHOD: All patients were reviewed at 1, 3, 5 years and maximal follow-up. Their functional evaluation was performed using Merle d'Aubigné's hip rating scale: pain score, motion score and walking score. Radiological assessment was performed to identify acetabular cup migration, bone lysis, and radio lucency. Revision for acetabular cup loosening was compiled. RESULTS: Five patients died, 27 THA were evaluated at maximum follow-up. Seven revisions were performed after the fifth years. Merle d'Aubigné's score was 14 at the time of revision. X-rays evidenced more than 5 mm migration of the cup, with massive bone lysis. Merle d'Aubigné's score was 16 for the 20 remaining THA. Radiologically, 10 cups showed migration less than 3 mm, five of which with lysis. Among the 10 cups without migration, 5 showed sclerosis near the acetabulum. The study evidenced that cases of migration exceeding 5 mm induced a revision during the next 3 years. DISCUSSION: Our study confirms failure of bone polyethylene direct fixation, with 25 per cent of revision after a five years period. This seems to be the result of micro movement, wear and bone lysis. A five years follow up is not sufficient to evaluate a component, since all revisions were performed after five years. For many authors, radiological evaluation of acetabular component migration is an important criterion for uncemented prosthesis. The EBRA computerized method is an accurate method for determining early migration, and can be used for pro and retrospective studies. CONCLUSION: Our study confirms a high rate of failures of the Freeman uncemented cup at an average of nine-year period, as previously reported in literature.

[Radiological evaluation of integration of bone grafts and bone substitutes after implantation to replace acetabular substance losses in reoperation of total hip prosthesis]. / Evaluation radiologique de l'intégration de greffes osseuses et d'un substitut osseux après implantation pour comblement des pertes de substances osseuses cotyloïdiennes lors des reprises de Prothèse totale de Hanche.

Plain radiograms are insufficient to evaluate the integrity of a graft used to replace acetabular tissue loss in reoperations for total hip replacement. The aim of this work was to compare radiographic, computed tomographic and magnetic resonance imaging findings. Two groups of patients including 12 hip joints in each were evaluated 5 years after undergoing reoperation for annular support. Allografts (5 cases) or xenografts (7 cases) were used in one group. Plain radiograms. CT-scan and MRI were performed in each patient. The graft-receiver bone borders were visible on the CT-scans but were not distinguishable on the radiograms. Bone and graft density and structure in contact with the implant could be determined on the CT-scan. MRI was difficult to interpret in most cases due to implant-induced artefacts and is not recommended in this type of reconstruction.

Accessory soleus muscle. Two case-reports, with a review of the literature.

The accessory soleus muscle is a supernumerary leg muscle that is rare and usually clinically silent. The best diagnostic strategy is not agreed on. We report two cases in which magnetic resonance imaging contributed significantly to the diagnosis and to the pretreatment evaluation.

Acetabular reconstruction in total hip revision using a bone graft substitute. Early clinical and radiographic results.

Thirty revisions were performed on loose total hip replacements with a specific acetabular reconstruction technique combining the use of a bovine bone substitute and a support ring. One patient died of a cause unrelated to the procedure. No migration of the acetabular implant or bone lysis of the heterograft was seen in 27 cases after 3 years. Radiologically, the heterograft gradually condensed, and its appearance matched that observed with an allograft. The 2 failures with implant migration and heterograft lysis were interpreted as technical errors related to the use of the Müller ring. In both cases the Müller ring was supported by the cancellous heterograft and not by the host bone.

[Scapho-capitate fracture. Apropos of a case, review of the literature]. / Fracture scapho-capitale. A propos d'un cas, revue de la littérature.

Scapho-capitate fracture is a rare lesion. Its mechanism is controversial. Forced extension seems to be the most frequent etiology, as this movement of the wrist induces scaphoid fracture by compression. Hyperextension of the wrist, as a result of the scaphoid lesion, allows contact between the posterior margin of the radius and the neck of the capitatum, inducing capitatum fracture. Continuation of the movement allows a two-stroke rotation of the capitate proximal pole. Analysis of a personal case and review of the literature demonstrated: the frequency of extension movement for etiology, delayed diagnosis, and the need for surgery. Surgery should be performed early with capitate reduction and osteosynthesis in case of instability, scaphoid reduction and minimal osteosynthesis a graft may be necessary. Immobilisation of the carpus and the thumb is essential until bone consolidation. Early surgery should avoid complications such as necrosis or pseudarthrosis.

[Value of puncture-arthrography in the diagnosis of infection of total hip arthroplasty]. / Intérêt de la ponction-arthrographie de hanche dans le diagnostic d'infection sur prothèse totale.

Arthrography with hip aspiration was performed in 143 patients with hip arthroplasties to determine its effectiveness as a technique for diagnosing infection. Thirty-three cases of infection were found. On 26 occasions the germ responsible was isolated in the joint fluid. In six other cases infection was revealed from cytologic or arthrographic findings, or from both. Only once was a diagnosis of infection not arrived at. In this series of patients, except in cases of evolutive inflammatory rheumatism, cytologic examination of the joint fluid was a discriminative factor in diagnosis. Hip aspiration arthrography had a sensitivity of 79 per cent for the diagnosis of infection in arthroplasty with isolation of the germ and a specificity of 100 per cent. The sensitivity of the diagnosis rose to 91% when any one of the following features was observed: leucocytosis of the joint fluid higher than 10,000 elements/mm3; presence of a fistula or of fistulization on arthrography; isolation of the germ in the joint fluid or the rinsing liquid.

[Our experience with ofloxacin in the treatment of osteoarticular infections]. / Notre expérience de l'ofloxacine dans le traitement des infections ostéo-articulaires.

Twenty patients with osteoarticular infections, fourteen post-arthroplasty and six with osteitis, were treated with ofloxacin, usually in combination. Sixteen staphylococcus strains including eight aureus and eight coagulase negative (modal MIC and MBC: 0.5 micrograms/ml), three Escherichia coli (modal MIC and MBC: 0.06 micrograms/ml) and one Peptococcus (MIC: 0.25, MBC: 0.5) were isolated. Treatment was given at a mean dose of 9.81 +/- 2.46 mg/kg for a mean duration of 100 days. The serum concentration of ofloxacin was measured at 3.73 +/- 2.13 micrograms/ml for a dosage of 8.23 +/- 0.94 mg/kg (25 assays) and 7.42 +/- 4 micrograms/ml for 11.46 +/- 1.3 mg/kg (23 assays). Bacteriological control was carried out nineteen times; in one case of staphylococcal osteitis, a relapse occurred on the 43rd day of treatment when the strain isolated was resistant to ofloxacin. Three patients presented adverse effects: two cases of bone and muscle pain and one cutaneous allergic reaction: treatment was withdrawn after two restarts. The antibacterial action, the good tolerance and the easy administration of ofloxacin make it a useful antibiotic in the treatment of osteoarticular infections, where a dosage of 8 mg/kg appears to be necessary, particularly in infections due to staphylococci.