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P Laffargue

Publications and source records attributed to P Laffargue.

At least 19 recordsLinked to original sources
PubMed2006

[Computer-assisted positioning of the acetabular cup for total hip arthroplasty based on joint kinematics without prior imaging: preliminary results with computed tomographic assessment].

PURPOSE OF THE STUDY: Most navigation systems for computer-assisted total hip arthroplasty (THA) require prior computed tomography (CT) or acquisition of multiple bone landmarks on the pelvis. In order to avoid these problems, we developed a computer-assisted navigation system without CT based on a kinematic approach to the hip joint. The principle is to orient the cup in relation to the cone describing the hip joint range of motion. The purpose of this work was to analyze preliminary results. MATERIAL AND METHODS: Eighteen primary THA were implanted with the system (16 women, two men, mean age 68 +/- 7.8 years, age range 54-83 years, 18 degenerative hip disease). Two optoelectronic captors were fixed percutaneously on the pelvis and the distal femur. The acetabulum was prepared first followed by the femur using reamers and broaches of increasing size. The last broach placed in the femur was equipped with a large head adapted to the newly prepared acetabulum. The range of hip motion was recorded to determine the maximal range of motion cone. The acetabular cup was thus positioned in order the prosthesis range of motion included entirely the maximal range of motion of the hip joint. RESULTS: One patient fell three weeks after implantation causing posterior dislocation; there was no recurrence. The Postel-Merle-d'Aubligné score improved from 8 +/- 2.9 (range 3-12) preoperatively to 17 +/- 0.8 (range 16-18) at last follow-up. None of the patients complained about the captor insertion and there were no cases of hematoma or fracture. Operative time was 35-40 minutes longer for the first four cases and was progressively reduced 15-20 minutes for the last four cases. Mean leg length discrepancy was 5.6 +/- 7.5 mm (range 0-25) before implantation and 0.6 +/- 3 mm (range -5 to 10 mm) at last follow-up. CT-scan measurements revealed a mean anteversion of the femoral implant of 18.2 +/- 8.5 degrees (range 0-31). Anatomic anteversion of the cup (measured from the pelvis landmark and thus independently of the position of the pelvis) was 24.7 +/- 8.8 degrees (range 12-40). The sum of the femoral and anatomic acetabular anteversions was 43 +/- 13.1 degrees (range 22-71). Anteversions were 16 degrees for the cup and 16 degrees for the stem for the one case of dislocation. CONCLUSION: This method can be used in routine without lengthening operative time significantly. It safely controls leg length and helps position the cup. This study demonstrated that there is no ideal position for the cup which can be used for all patients. Because of the wide range of inclination and anteversion figures, half of the cases were outside the safety zone recommended by Lewinnek.

Acetabulum↗
PubMed2005

[Measurement of head penetration on digitalized radiographs: reproducibility and accuracy].

PURPOSE OF THE STUDY: Wear of the acetabular component of total hip arthroplasty (THA) is incriminated as the cause of loosening and bone resorption. Consequently, an accurate evaluation of wear can contribute to the prediction of mechanical failure of the arthroplasty. Among the different methods proposed, digitalized imaging using a high-resolution scanner associated with data processing procedures appears to be a simple easily accessible technique. A system based on this concept has been introduced in orthopedics. To our knowledge, there has been no report on the system's reproducibility and accuracy. MATERIAL AND METHODS: Thirty-nine radiography series for THA served as the basis for the evaluation of intra- and interobserver reproducibility. We evaluated the error induced by digitalization, the error induced by digitalized measurement, the accuracy of the measurements as a function of the material constituting the bearing, the intra- and interobserver reproducibility for repeated measures of THA wear (six observers and two observations). All measurements were done after digitalization and analyzed with a specimen designed software. RESULTS: The inter and intra-observer coefficients of concordance were 0.6 and 0.58 respectively, i.e. moderate reproducibility. Depending on the prosthetic material, the error and accuracy of the system varied from 0.112 to 0.44 mm and 0.28 to 1.29 mm respectively. To obtain valid inter-observer reproducibility, the number of observers had to be limited to three (coefficient = 0.82). The type of implant had an influence on measurement error. The error was 0.342 for polyethylene cups and 0.118 for press-fit metal back cups. Likewise, for a metallic head measuring 22.2 mm, the error was 0.138 mm while for a ceramic head or metal head measuring 28 mm, the error was 0.28 mm and 0.112 mm respectively. DISCUSSION AND CONCLUSION: The accuracy and error depend directly on the type of implant. The accuracy was better for metallic heads associated with metal-backed cups. To obtain satisfactory interclass correlation, the number of observers should be three. The proposed digitalized measurement system should be relatively accurate and reproducible. Its use can be recommended for the evaluation of wear after five years of follow-up, limiting the number of observers to three.

Acetabulum↗
PubMed2005

[Reliability of porous coating metal-backed cups: advantages and adverse effect of a posterior elevated rim polyethylene liner].

PURPOSE OF THE STUDY: We analyzed primary implantation of the Duraloc cup associated with a self-locking Muller stem at 9.6 +/- 1.6 years (8.6-11.4). Because of its particular 3/5 semi-spherical shape, the Duraloc cup has been associated with a high rate of dislocation. The objective of this study was to evaluate the efficacy of an anti-dislocation posterior elevated rim polyethylene liner on long-term dislocation rate and wear. MATERIAL AND METHODS: The series included 89 arthroplasties implanted between 1991 and 1993 in 82 patients, mean age 56.8 +/- 12.6 years (17.2-87). The Postel-Merle-d'Aubligné (PMA) score and subjective evaluation with a visual analog scale were used for the clinical assessment. Changes in the bone-cup interface, cup migration, and polyethylene wear were assessed radiographically. RESULTS: At last follow-up, the PMA function score was 16.2 +/- 1.9 points (10-18) (81% good, very good and excellent results). The postoperative x-rays showed a low incidence of lucent lines and osteolysis, respectively 8% and 4%. Mean annual linear polyethylene wear was 0.11 +/- 0.066 mm (0.03-0.57) and only 4% of the cups showed wear greater than 0.2 mm/year. Wear was correlated with the presence of acetabular osteolysis and high activity level. Two cups migrated (3-4 cm medialization). Three cups were revised, one for deep infection, one for recurrent dislocation, and one for dislocation associated with major wear. The rate of dislocation was 2.2% (two cases). Overall survival was 97.3% at 9.6 years (95%CI 0.93-1.0). DISCUSSION: Compared with other series in the literature using this implant, the presence of a posterior elevated rim polyethylene liner reduced the rate of instability and did not increase wear. The Duraloc cup is recognized as a reliable implant exhibiting excellent osteointegration and a low rate of migration. The presence of a posterior rim is associated with a lower rate of dislocation and does not increase wear. It can thus be proposed for primary implantation. The posterosuperior position for the liner is recommended.

Adolescent↗
PubMed2003

[Management of stiffness after total knee arthroplasty: indication for different mobility management in 62 cases].

PURPOSE OF THE STUDY: Stiffness of the knee is a common reason for revision of total knee arthroplasty. Three methods are currently used to mobilize the knee: manipulation under general anesthesia, arthroscopic release, open surgical release. The purpose of the present work was to determine the respective indications of these three procedures in a large single-center study. MATERIAL AND METHODS: We retrospectively assessed all revision procedures without component exchange in patients with a stiff total knee prosthesis. Sixty-two procedures were performed in our institution between 1989 and 2001. All patients were followed for at least one year. There were 34 manipulations under general anesthesia, 18 arthroscopic release procedures, and 10 open surgical release procedures. The three groups were not different for all parameters studied except time interval between implantation of the prosthesis and the mobilization procedure: 17 weeks for manipulation under general anesthesia, 46 weeks for arthroscopic release, 97 weeks for surgical release. A comparable postoperative analgesia and rehabilitation program was instituted for all patients. RESULTS: Range of flexion improved after all 62 procedures: mean 58.4 degrees before the procedure, mean 94.6 degrees at one-year follow-up. Flexion deformity also improved from 7.6 degrees to 2.5 degrees at one year (p=0.001). From surgery to one-year follow-up, there was a decrease in flexion (104.6 degrees to 94.6 degrees ) and an increase in flexion deformity (1.3 degrees to 2.5 degrees ) (NS). The worst postoperative ranges of motion were observed at six weeks after the procedure. Improvement was then observed up to six months but was not significant. There was no improvement in flexion beyond six months after the mobilization procedure. The results of the three techniques were not significantly different. Failures were however more frequent when manipulation under anesthesia was performed more than eight weeks after prosthetic insertion, and when arthroscopic release was performed more than six months after prosthetic insertion (p<0.01). DISCUSSION AND CONCLUSION: We recommend treatment of stiff total knee prosthesis by manipulation under general anesthesis if the procedure is performed less than eight weeks after implantation; a delay of six weeks is even better because intraoperative complications were observed for patients treated between six and eight weeks. Between eight weeks and six months, arthroscopic release should be advised, surgical release thereafter. Whatever the delay, this protocol is appropriate for stiff knee prostheses without infection and without component malposition. Whatever procedure is applied, the definite range of motion is reached six months after the intervention.

Arthroplasty, Replacement, Knee↗
PubMed2002

In vitro studies of human and rat osteoclast activity on hydroxyapatite, beta-tricalcium phosphate, calcium carbonate.

Investigations on the ceramic degradation caused by osteoclasts are designed to assess osteoclast-ceramic interactions and to determine which ceramics are more suitable for use as bone substitute. This study investigated the resorptive activity of osteoclasts on ceramics presenting different solubility rates. Osteoclasts isolated from new-born rat and from human giant cell tumour were cultured on different bioceramics: hydroxyapatite (HA), beta-tricalcium phosphate (TCP) and calcium carbonate (calcite). Cytoskeletal was revealed by actin labelling and ceramic surfaces were observed by scanning electron microscopy (SEM). On all materials, the distribution of actin in typical ring was revealed. SEM examinations showed a clear difference in the shape and the depth of resorption lacunae on different ceramics. On pure HA, a superficial attack, clearly visible but very little extended. Numerous resorption lacunae, deep and well-delimited were observed on pure beta-TCP, but attacks less punctually were detected too. On pure calcite, an attack with form of spikes, very widespread but superficial was revealed. Degradation measurements revealed a significant increase of P release from the phosphocalcic ceramics and of Ca from all ceramics in the presence of osteoclasts. The both cell models found these characteristics, the rat osteoclasts were also an excellent model to study the ceramic resorption.

Adsorption↗
PubMed2002

[Shoulder fusion for sequelae secondary to brachial plexus palsy].

PURPOSE OF THE STUDY: We examined clinical and radiological outcome in fifteen patients who underwent shoulder fusion after brachial plexus palsy. MATERIAL AND METHODS: This retrospective analysis included 15 patients who underwent shoulder fusion between 1981 and 1997 for the treatment of sequelae secondary to brachial plexus palsy. There were 13 men and two women, mean age 24.6 years (range 18-33 years). The right shoulder was fused in nine cases and the dominant shoulder in ten. There was one obstetric paralysis and one paralysis secondary to a cervical neurinoma. Eleven patients were motorcycle accident victims and two were automobile accident victims. The patients were installed in the lateral supine position with 30 degrees antepulsion and 60 degrees abduction, measured from the axillary axis of the scapula, and internal rotation. All patients had internal fixation by plate through a posterior approach. The same observer examined all the patients at last follow-up. Clinical and radiological findings were recorded and the position of the arthodesis was analyzed. RESULTS: There was one case of delaved fusion and one case of late humeral fracture. The arthrodesis position was abduction 52 degrees, internal rotation 20 degrees, flexion 20 degrees (means). Hand-mouth and hand-pocket movements were possible for all patients. Seven had no pain. Active motion was: 48 degrees abduction, 46 degrees antepulsion, 40 degrees internal rotation, 4.6 degrees external rotation, 23 degrees retropulsion. For 13 patients, mean lifting force was 5.2 kg.

Adolescent↗
PubMed2001

[Malignant fibrous histiocytoma of bone 20 years after femoral fracture treated by plate-screw fixation: analysis of corrosion products and their role in malignancy].

We report a case of malignant fibrous histiocytoma of the bone that developed 20 years after a femoral fracture treated by plate-screw fixation. Similar cases reported over the past fifteen years in the literature suggest the possible mechanisms of sarcomatous degeneration. The possible carcinogenic effect of corrosion products is emphasized. Dispersion energy spectrometry of intracellular particles on the periphery and at the center of the tumor demonstrated the presence of chromium, iron and nickel at different concentrations. The association with other elements clearly demonstrates that the corrosion products were metabolized. The presence of metallic components in tumoral cells suggests a possible relationship between metallic implants and malignancy. These observations emphasize the importance of creating a national, or even international, registry of malignant tumors that develop in contact with metallic implants in order to search for a possible cause and effect relationship.

Adult↗
PubMed2001

[Reconstruction of the distal radius for primary bone tumors using a non-vascularized fibular graft (report of 4 cases)].

We report four cases of primary bone tumour of the distal radius. Follow-up averaged ten years with a range of four to 13. Each case underwent excision of the tumour followed by reconstruction with a non-vascularised fibular graft. The aim of our study was to investigate the carcinologic, functional and radiological results at an average of ten years after the initial surgery. There were three high grade osteosarcomas and one giant cell tumour of bone. The mean postoperative wrist flexion was 45 degrees, extension was 20 degrees, pronation 30 degrees and supination 50 degrees. Radial tilt was a mean 10 degrees and ulnar tilt 15 degrees. All the patients had satisfactory function so as to be able to perform activities of daily living and to work. Grip strength was normal in three cases and reduced in one. Bone graft healing occurred at a mean of six months with a range of from four to nine months. Resection followed by a non-vascularised fibular graft is an effective way to managing these patients.

Adolescent↗
PubMed2001

[Atypical Fenton syndrome].

The case of a patient 41 years old is reported. He sustained a posterior open carpal fracture dislocation transcapho-trans-capitate with radius styloid process fracture. The original aspect of this observation is that the lunatum was enucleated. The treatment was not usual. Capitatum bone was first fixed and associated with an external fixation. Proximal row carpectomy was performed in a second procedure when removing internal and external fixation, capitatum being healed. Follow up is now at four years with a very good radiological and clinical result. The patient is working with an intermittent mild pain. Radiographic examination demonstrated a very good vascularisation of the capitate head.

Adult↗
PubMed2000

Adsorption and release of insulin-like growth factor-I on porous tricalcium phosphate implant.

In order to develop bone substitutes, the design of biomaterials like calcium phosphate ceramic loaded with bone growth factor are of great interest. However, it is necessary to control the amount of growth factor adsorbed onto ceramics and the kinetics of its release. Radiolabeling of insulin-like growth factor-I (IGF-I) with 125-iodine ([(125)I]-IGF-I) and its adsorption onto porous tricalcium phosphate (TCP) cylinders enabled us to establish the time-adsorption and time-release curves using various concentrations of IGF-I. The adsorption curve increased rapidly and then flattened out at 72 h; 90% of the maximum was already reached at 24 h; and 20% of the adsorbed IGF-I was released in water within 4 days. In human serum the release was faster at 82% within 4 days. In vivo evaluation on an animal model was then performed. Rabbits' bilateral femoral cylindrical bone defects were filled with the TCP cylinders, which were either carrying IGF-I or implanted alone as a control in each rabbit. Bone turnover and ceramic resorption were stimulated by IGF-I loaded TCP according to standard radiography, dual-energy X-ray absorptiometry, histology, and histomorphometry.

Adsorption↗
PubMed1999

Evaluation of human recombinant bone morphogenetic protein-2-loaded tricalcium phosphate implants in rabbits' bone defects.

Porous beta-tricalcium phosphate (betaTCP) has osteoconductive properties. The adsorption of human recombinant bone morphogenetic protein-2 (rhBMP-2) onto TCP could realize an osteoinductive bone substitute. We evaluated it on an animal model using dual-energy X-ray absorptiometry (DEXA) and solid-state 31P nuclear magnetic resonance (NMR) spectroscopy. BetaTCP cylinders loaded with rhBMP-2 were implanted into rabbits' femoral condyle bone defects, and betaTCP alone as control into the contralateral femur. We studied two different doses of rhBMP-2 (10 and 40 microg) on two groups of four animals. Evaluation consisted in radiography, histology, and histomorphometry, DEXA, and NMR spectroscopy using an original method of quantification. With both doses of rhBMP-2, we observed on radiographs an increase of trabecular bone around implants. Histology showed resorption of the ceramic, trabecular bone with osteoblasts and osteoid substance around the implants, and colonization inside the porous betaTCP by new bone formed. Histomorphometry showed that the osteoid surface (OS/BS) was greatest with the high dose of rhBMP-2. The difference was slight between the low dose of rhBMP-2 and control. DEXA showed a dose-dependent increase of bone mineral density of rhBMP-2-loaded betaTCP vs. control. NMR spectroscopy confirmed that the amount of new bone formed in betaTCP was greater when betaTCP carried rhBMP-2, and increased with the dose of rhBMP-2 used. We showed that betaTCP was a good matrix for rhBMP-2, which gave it osteoinductive properties in an orthotopic site, in a dose-dependent manner. Thus, such composite biomaterial seems to be of great interest in reconstructive bone surgery. Further studies are needed in clinical practice to determine optimal doses.

Absorptiometry, Photon↗
PubMed1999

[Reconstruction of the anterior cruciate ligament: arthrotomy versus arthroscopy].

The aim of this study was to compare the results of arthroscopic with open arthrotomy reconstruction of the anterior cruciate ligament, as treatment of chronic anterior laxity. 54 knees (among 63) were evaluated, 33 reconstructions were performed according to Kenneth Jones technique with arthrotomy (from 1990 to may 1993) and 21 were arthroscopically-assisted (from may 1993 to 1996). Meniscectomy was associated respectively in 22 and 7 cases. The average interval between initial injury and surgery was 18 and 18.6 months. Follow-up was one year at least. We evaluated mobility, amyotrophy and quadriceps and hamstrings muscular deficit: static at 1 month and using Cybex isokinetic tests at 2, 3 and 6 months and 1 year. Postoperative residual laxity and Arpege cotation were evaluated at 1 year. Student and Mann Whitney tests were used for statistical evaluation. As complication we noted respectively after arthrotomy and after arthroscopy: 7 (21.2 p. 100) and 4 (19 p. 100) algodystrophy, 1 (3 p. 100) and 1 (4., 7 p. 100) Cyclops syndrome, and 2 (6 p. 100) and 1 (4.7 p. 100) anterior knee pain. Lack of extension and flexion were respectively -5.4 degrees/130 degrees and -1.9 degrees/136 degrees at 3 months (p = 0.04) and -3.5/134 degrees and -1.5 degrees/138 degrees at 6 months (not significative). At 1 month, static hamstrings deficit was 41.3 p. 100 after open arthrotomy and 29.6 p. 100 after arthroscopic assisted (p = 0.05). At 2 months, isokinetic hamstrings deficit was lower after arthroscopic assisted (21.6 p. 100 at 60 degrees; 20.8 p. 100 at 180 degrees) than after open arthrotomy (32.8 p. 100; 32.5 p. 100) (p = 0.039 and 0.008). This difference was found for hamstrings until 3 months. At 6 months and 1 year, no difference was found for Cybex tests. In Arpege score, at 1 year, 73.3 p. 100 were very satisfied or satisfied after open arthrotomy and 77.7 p. 100 after arthroscopy. Global results were excellent or good in 66 p. 100 after open arthrotomy and 83 p. 100 after arthroscopy. Radiological laxity was less than 5 mm in 88 p. 100 after open arthrotomy and 92 p. 100 after arthroscopic assisted. So, after arthroscopically assisted procedure, the number of algodystrophy and anterior knee pain was lower, and until 3 months, range of motion was better and hamstrings deficit was lower. After 6 months, difference about range of motion or muscular deficit were not significative. At 1 year, after arthroscopic procedure, results seemed better with a lower rate of residual laxity and better global results, but the number of medial meniscectomies was lower in this group. In conclusion, the arthroscopic-assisted procedure seems to allow a faster rehabilitation.

Adolescent↗
PubMed1998

[Fracture of the scaphoid carpal bone secondary to an intraosseous cyst. Apropos of a case].

The authors report a cases of scaphoid fracture secondary to an intraosseous cyst in a young patient performing a high-risk sport. Intraosseous synovial cyst is a frequent and usually asymptomatic disease. Its aetiology remains controversial. No cases of fracture have been previously described. Our patient may have presented several risk factors for scaphoid fracture secondary to a synovial cyst.

Adult↗