Relevancy and reproducibility of magnetic resonance imaging (MRI) interpretation in multiple-ligament injuries and dislocations of the knee.

INTRODUCTION: After multiple-ligament injuries and dislocations of the knee, clinical assessment of the soft tissues is difficult and MRI is generally performed. HYPOTHESIS: MRI is a reliable examination, providing a precise and reproducible assessment of soft-tissue lesions after multiple-ligament injuries or dislocations of the knee. MATERIALS AND METHODS: Forty patients presenting multiple-ligament lesions of the knee were included in this multicenter prospective study. All had an MRI of the knee in the 48 h following their accident. Thirty-four patients were treated surgically. A 17-item standardized interpretation guide was created. Intraobserver reproducibility was assessed by comparing the interpretations of five surgeons at two different times 3 weeks apart. Interobserver reproducibility was evaluated by comparing the results of the interpretations of 40 MRIs performed by three pairs of surgeons. The relevance of the MRI interpretations was determined by comparing the results of the surgeons to those of a radiologist and with the data from the surgical reports. RESULTS: The overall intraobserver and interobserver agreement was low. Comparing the surgeon's results with the radiologist's results and the surgical data, the agreement was low. DISCUSSION: After multiple-ligament injuries and dislocations of the knee, a precise diagnosis is necessary. This study provides an isolated demonstration of the lack of precision and reproducibility of MRI interpretations for the diagnosis of the lesion's topography. MRI should be integrated into a complete assessment with a precise clinical exam and stress X-rays. LEVEL OF EVIDENCE: Level IV, prospective case-control study.

Survival analysis of an asymmetric primary total knee replacement: a European multicenter prospective study.

PURPOSE OF THE STUDY: This multicenter prospective study objective is to provide midterm results and 10-year survival analysis of the original Natural Knee-I System™ as experienced by a group of surgeons performing, within various settings, primary total knee replacement (TKR) in the general population. HYPOTHESIS: The midterm experience with this TKR system in the hands of independent surgical teams can duplicate the satisfaction level that was already published by the designer's group itself. MATERIAL AND METHOD: Two hundred and sixty-three primary TKR were performed by seven surgical teams (37 surgeons) and prospectively evaluated in four European countries. Mean age of the 263 patients (sex ratio, 2.7 females/1 male) was 69 years (range, 35-92) and diagnosis was primary osteoarthritis in 85%. For the 247 TKR with complete operative data, the approach was subvastus in 59%, posterior cruciate ligament was spared in 78%, patella was resurfaced in 56%, and 79% of reconstructions were totally cement-free. Fixation mode was only depending on the surgeon's choice. RESULTS: At 76 months average follow-up (range 24-190 months), modified Hospital for Special Surgery knee mean score improved from 48 points preoperatively to 83 points. Four reoperations and five revision procedures were required for eight knees. Over the 14-year survey period, the overall revision rate burden was 2% and revision rate per 100 observed component/year, 0.32. At 10 years, survivorship (with revision for aseptic loosening as its end-point [two fully cementless knees]) was 98.6%. DISCUSSION: Both this multicenter study and data drawn from national registers provided outcomes with equivalent level of satisfaction at equivalent follow-up to those reported by the NK-I prosthesis designer. There was no significant difference between revision rates of cemented, hybrid or cementless reconstructions. CONCLUSION: In non-designer orthopaedists' hands, the Natural Knee-I System™, either with cemented or cementless fixation, provided satisfying midterm results as normally expected in primary TKR with such a modern modular prosthesis. LEVEL OF EVIDENCE: Level IV. Prospective study.

Dislocation and bicruciate lesions of the knee: epidemiology and acute stage assessment in a prospective series.

INTRODUCTION: Knee dislocation and bicruciate lesions are rare. Assessments of results from retrospective series carry an insufficient level of evidence. A prospective multicenter study was therefore set up, under the auspices of the French Society of Orthopedic Surgery. MATERIAL AND METHODS: The inclusion period covered the whole of 2007. Clinical, imaging (dynamic X-ray and MRI) and vascular (angioscan and arteriography) assessment was performed systematically. In patients over the age of 60 years, ligament lesions were always managed non-surgically; in those under the age of 60 years, surgery was considered in the absence of associated vascular lesion or open dislocation and if there was frontal laxity exceeding 15 degrees or a posterior drawer test greater than 10mm. The posterior cruciate ligament (PCL) and peripheral ligament tears were repaired or reinforced under arthroscopy or by arthrotomy. The anterior cruciate ligament was never operated on. In all other cases, management was conservative. RESULTS: Sixty-seven knees were included (55 male, 11 female; mean age: 37 years). Fifteen patients (25.4%) had bicruciate lesion, and 44 (74.6%) knee dislocation. Mean trauma-to-reduction interval was 3 hrs 50 min. Only one of the nine cases of popliteal artery lesion exhibited discernible distal pulse wave. Only three of these patients underwent vascular surgical repair. Twelve knees (five bicruciate lesions, seven dislocations) had isolated common peroneal nerve damage. DISCUSSION: This prospective study detailed the epidemiology and treatment of the lesions encountered, with the option of PCL and peripheral ligament reconstruction. The results, however, still require long-term analysis.

[Femoral neck fractures in patients over 50 years old]. / Les fractures du col du fémur après 50 ans.

INTRODUCTION: Despite many papers and instructional course lectures, therapeutic guidelines are not clearly defined about treatment of femoral neck fractures. The aim of this multicentric French symposium was to prospectively study the results of current therapeutic options in order to propose scientifically proven options. MATERIAL AND METHODS: Three prospective studies were carried out in order to answer to these questions: (1) is it possible with anatomical reduction and stable fixation to lower the non union and osteonecrosis rate? (2) is functional treatment of Garden 1 fractures successful in more than 65 years patients? (3) what criteria are useful to choose the kind of arthroplasty for more than 65 years patients? RESULTS: For the 64 patients between 50 and 65 years old included in the first study, 44 ORIF and 17 prostheses were performed. No open reduction was performed in this series despite a 34% malreduction rate. The risk for displacement after functional treatment of Garden 1 fractures is 31%. For patients over 65 years old, almost fractures are treated in this series by an arthroplasty. The one-year mortality rate after displaced femoral neck fracture was 17%. Functional results were better in total hip prosthesis group than in bipolar or unipolar group. Non cemented stems were not safer than cemented ones in frail patients. DISCUSSION AND CONCLUSIONS: For young patients, ORIF should be the treatment of choice: the initial displacement and its effects on the femoral head vascularisation, the quality of reduction and fixation are the two most significant factors for good outcome. For Garden 1, fractures in patients 65 years old or more, it is proposed to performed an internal fixation despite in two thirds of the cases, it should be unnecessary because non identification of predictive factors of failure. For patients over 65 years old, the type of arthroplasty to perform in displaced fractures is to be chosen according to the preoperative mobility and comorbidities. Because of acetabular erosion with long-term follow-up, it is clearly indicated to perform total hip replacement for patients with life expectancy of 10 years or more. For frail patients, unipolar arthroplasty is the best option. The place for bipolar or uncemented implants is not yet well-defined and more prospective trials are needed. In this multicentric study, results appear quite different in terms of mortality, or functional status. These differences seem to be related to technical choice, geriatric care, nutritional consideration or surgical organisation, all factors that may be of major importance for prognostic.

[Metal-on-metal hip replacement using Metasul cups cemented into Muller reinforcement rings after a mean 5-year (3-8) follow-up: improvement of acetabular fixation by comparing with direct cementation to bone]. / Résultats cotyloïdiens favorables du couple métal-métal scellé dans des armatures métalliques.

PURPOSE OF THE STUDY: Early loosening, before a three-year follow-up, has been observed with cemented cups having a metal-on-metal insert in a polyethylene cup. The metal-on-metal bearing has been incriminated as the source of the problem because of its rigidity (particularly for small cups measuring less than 50 mm) and the creation of stress conditions unfavorable for a cemented fixation. The purpose of this retrospective study was to determine whether this phenomenon is observed when the cement is fixed not directly into the bone, but via a Muller reinforcement ring. MATERIAL AND METHODS: From 1998 to 2004, 23 arthroplasties using a cemented Metasul cup in a reinforcement ring were implanted in 22 patients (16 women and six men) aged on average 44 years (range 24-56 years). The series included six primary total hip arthroplasties (three for dysplasia, two for protrusions, one for rheumatoid arthritis and one for arthritic degradation) and seventeen revisions (two septic). The Metasul cup (Zimmer-Centerpulse) combined a 28 mm modular head anchored in a femoral implant (two cemented, 21 pressfit) and a polyethylene cup with a Metasul insert (13 of 23 measuring<50mm). In all cases, the cup was fixed with low-viscosity cement in a Myller metal reinforcement ring fixed with screws (Zimmer-Centerpulse). All patients were reviewed clinically and radiographically at a mean 5-year follow-up (range 3-8 years). Acetabular and femoral fixation were analysed (search for lucency and implant migration). RESULTS: Revision was not necessary in any patient for failure of the acetabular fixation. The mean Postel-Merle-d'Aubigné score improved from 12.9 points (range 7-17) to 17.5 points (range 16-18). The radiographic analysis did not reveal any sign of lucency between the cup and ring, nor any migration of the ring. There was no evidence of femoral osteolysis but one femoral revision was needed due to fracture of the lateral cortical identified six weeks after implantation. DISCUSSION AND CONCLUSION: Cementing the metal-on-metal cup into a reinforcement ring can avoid the risk of loosening observed after direct cementing into bone. In our study, the large number of small cups (13/23) would have been expected to produce a high rate of acetabular lucent lines and/or a high rate of early revision, as reported by others, as early as 24 months. Our series was also different from others by the use of pressfit femoral implants in most patients, which should reduce the risk of cement debris in the bearing. Longer follow-up will be necessary to confirm the good results observed to date which suggest that direct cementing of the cup into the bone should be incriminated rather than the metal-on-metal bearing to explain the reported failure of cemented Metasul cups.

[Low accuracy of the anterior pelvic plane to guide the position of the cup with imageless computer assistance: variation of position in 106 patients]. / Fiabilité limitée du plan pelvien antérieur pour l'implantation assistée par informatique de la cupule d'une prothèse totale de hanche.

PURPOSE OF THE STUDY: The anterior pelvic plane, also called the Lewinnek plane, is commonly used as the reference plane to guide imageless computer assisted surgery for total hip arthroplasty (THA) because this plane is considered to be globally vertical in the standing position. To our knowledge, no study has evaluated this hypothesis or the potential variations in orientation as a function of gender, position of the subject, or THA insertion. The purpose of this work was to examine these different hypotheses in a radio-clinical study. MATERIAL AND METHODS: The orientation of the anterior pelvic plane was measured in relation to the vertical plane on plain lateral x-rays of the pelvis in the standing position. X-rays were studied for 106 patients: 1) 82 patients with a THA (40 with at least one dislocation, 42 with a stable hip selected randomly, 19 with a standing lateral x-ray before and after arthroplasty) and 24 control subjects for whom lateral images were obtained in the supine and standing positions to assess potential position-related changes in orientation. RESULTS: The orientation of the anterior pelvic plane was not affected by gender or age. The anterior pelvic plane formed an angle greater than 5 degrees with the vertical plane in 38% of patients and more than 10 degrees in 13%. The orientation of the anterior pelvic plane was not significantly different between the study groups (control versus THA) nor between the THA groups (stable versus dislocated). The supine position modified significantly the orientation of the anterior pelvic plane which changed on average from 1.20 degrees to -2.25 degrees ; the change was greater than 7 degrees in twelve subjects. Implantation of a THA did not modify signi-ficantly the orientation of the anterior pelvic plane in the standing position for the 19 subjects [the variations were small (-1 degrees to 7 degrees on average, range -21 degrees to 8 degrees ) but greater than 5 degrees for 7 of 19 subjects]. DISCUSSION: Most teams use the anterior pelvic plane to guide computer-assisted navigation, considering that this plane is vertical in the standing position. Our findings show however that this is not true for 38% of subjects with a margin of error of 10 degrees , i.e. about half of the anatomic anteversion of the acetabulum. Moving to the standing position would produce a significant variation in the orientation of the anterior plane of the pelvis. This is a source of error which has not been integrated into most imageless navigation systems. Similarly variations in the position of the pelvis from the standing to sitting and supine positions which can produce impingement or dislocation have not been taken into consideration. CONCLUSION: Variations in the orientation of the anterior pelvic plane in relation to the vertical would suggest that this plane is not a reliable reference. To our knowledge, there is no reliable reference which can be easily identified during the operation which would take into account variations in the position of the pelvis. We thus believe it would be preferable to attempt to operate without a reference plane, relying on a more kinematic approach to guide computer-assisted implantation of the THA cup.

[Polyethylene liner replacement: behavior and morbidity in 68 cases]. / Conservation du métal-back lors d'une reprise de prothèse totale de hanche avec changement d'insert: morbidité et devenir de 68 changements d'inserts.

PURPOSE OF THE STUDY: Isolated acetabular polyethylene exchange is advocated as an advantage of metal-backed cups, since the acetabular bone stock can be spared and operative time is shorter. The purpose of this study was to determine whether this is true. MATERIAL AND METHODS: A consecutive serie of 68 THA revisions involving replacement of the polyethylene liner was analyzed retrospectively (liner replacement alone for 37 hips and liner replacement plus femoral component revision for 31). The posterolateral approach was used for the revision in all cases. This series was compared with a control series of revisions involving the acetabular component with revision of the femoral component in patients matched for age, sex, and BMI. RESULTS: Operative time and hospital stay were significantly shorter when the revision involved the polyethylene liner alone. In 19 hips, a limited zone of osteolysis was observed around the liner before replacement. At last follow-up, new zones of osteolysis were noted in two hips and aggravation in five, one of which required revision because of acetabular loosening. Episodes of dislocation were observed in nine hips (2 anterior and 7 posterior) of which three underwent revision because of recurrence. These dislocations occurred after liner replacement (n=4) or combined liner and femoral component replacement (n=5). Dislocations were more frequent after multiple hip operations and when the cup inclination was less than 40 degrees . Ten revisions were required for: an unclipped liner (n=2), recurrent dislocation (n=3), acetabular loosening (n=1), infection which was cured after a one-stage procedure (n=1). At seven years, survival was comparable between liner replacement alone (82+/-10%), combined liner replacement and femoral component revision (84+/-11%), and femoral component and acetabular component revision (82+/-11%). DISCUSSION: Changing the cup liner can limit morbidity compared with a more complex revision, but liner replacement alone is insufficient in the event of acetabular osteolysis. It would be preferable to combine osteolysis debridement with a graft or a complete revision. The survival rate after liner replacement is comparable with that observed after more complex revision but the risks of dislocation or unclipped insert are significant. For this reason, liner replacement alone should only be proposed if the cup is correctly aligned and if the new liner can be solidly clipped into the metal back. In addition, this simplified procedure should not be attempted after multiple hip operations.

[A new type of acetabular fracture: "true" posterosuperior fracture, a case report]. / Nouvelle variété de fracture postéro-supérieure de l'acétabulum: stratégie thérapeutique à propos d'un cas.

We report a new variety of acetabular fracture. This posterosuperior fracture affected the acetabular roof and the iliac wing as other superior fractures and presented a supplementary fracture line disjoining the major part of the posterior wall. Two our knowledge, in a series of 940 fractures of the acetabulum, Letournel alone described two cases of superior fractures involving the roof with a slightly anterior fracture line in the iliac wing but with an intact posterior wall in both cases. The patient was treated by osteosynthesis via the iliofemoral approach described by Judet-Letournel. This approach was warranted to achieve simultaneous exposure of both columns and the posterior wall which was separated from the proximal fragment by a secondary fracture line. At six months, the functional result was considered good as assessed by the Postel-Merle-d'Aubigné score. This case widens the Letournel classification and emphasizes the importance of computed tomography to evaluate, in superior fractures of the acetabulum, the volume of the posterior wall fragment and its continuity with the cranial portion of the acetabulum and the iliac wing. For fixation, the surgical approach must be chosen individually according to the position of the fracture lines visualized on the preoperative computed tomography.

[Computer-assisted positioning of the acetabular cup for total hip arthroplasty based on joint kinematics without prior imaging: preliminary results with computed tomographic assessment]. / Positionnement de la cupule d'une prothèse totale de hanche par navigation sans image basée sur la cinématique articulaire: Premiers résultats avec evaluation tomodensitométrique de l'orientation des implants.

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.

[Bilateral Moore hemiarthroplasty: 36 years of good tolerance without loosening or osteolysis]. / Arthroplastie de Moore bilatérale au recul de 36 ans avec bonne tolérance cartilagineuse sans descellement ni ostéolyse.

We report an illustrative case of bilateral Moore arthroplasty with the clinical and radiographic results at 36 years follow-up. The femoral prostheses were implanted for necrosis of the femoral head when the patient was 46 years old. At implantation the patient's physical activity level was high (Devane 4) and remained so until retirement at age 65 years. His activity level remained high (Devane 3) to the age of 82 years when the patient suffered a Vancouver B1 periprosthetic fracture on the left. At this date, both arthroplasties were free of loosening an osteolysis. Plate fixation with wiring led to fracture healing. The Postel Merle d'Aubigné score was 17 before the fracture and 16 at healing (with a pain score of 6 both before and after). Radiographically, acetabular cartilage tolerance was excellent. This case illustrates the excellent clinical outcome obtained with the Moore hemiarthroplasty at more than 35 years despite less than satisfactory initial fixation and the absence of resurfacing. The fact that this prosthesis does not have a polyethylene element prevented the development of osteolysis which could have been expected with such a long postoperative period in this a highly active patient. Favorable factors (good abductor lever arm, adapted head diameter, resistance of the acetabular cartilage in a young subject with femoral head necrosis) may have played a role in this particular case since the excellent and sustained outcome was observed on both sides. This exceptional longevity provides useful information for better determining precise indications for head cups for the treatment of necrosis of the femoral head.

[Reliability of porous coating metal-backed cups: advantages and adverse effect of a posterior elevated rim polyethylene liner]. / Fiabilité d'une cupule métal-back vissée a revêtement poreux: intérêt et innocuité d'un dispositif anti-luxation.

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.

[Measurement of head penetration on digitalized radiographs: reproducibility and accuracy]. / Mesure de la pénétration céphalique sur des radiographies numérisées: reproductibilité et précision.

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.

[Pseudo-winging of the scapula and snapping scapula secondary to solitary exostosis: two cases]. / Scapula alata statique et accrochage scapulaire secondaires à une exostose solitaire. A propos de 2 cas.

Pseudo-winging of the scapula and scapular snapping are two clinical signs of upper girdle insufficiency. The association of these two signs is highly suggestive, if not pathognomonic, of exostosis of the ventral aspect of the scapula. Resection of the exostosis is recommended to prevent pain and sarcomatous degeneration.

[Management of stiffness after total knee arthroplasty: indication for different mobility management in 62 cases]. / Traitement des raideurs sur prothèse totale du genou: indication des différents gestes mobilisateurs à propos de 62 cas.

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.

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.

[Shoulder fusion for sequelae secondary to brachial plexus palsy]. / Arthrodèse d'épaule pour séquelles de paralysies du plexus brachial.

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.

[Anuerysm of the ulnar artery in a mountain biker. A case report and review of the literature]. / Anévrisme de l'artère ulnaire chez le cycliste tout terrain. A propos d'un cas clinique et revue de la littérature.

A case of ulnar artery aneurysm following repeated hand injury in a mountain biker, is reported. The patient underwent surgical aneurysm resection with venous graft end-to-end anastomosis. Complete relief of symptoms is observed at 3 years follow-up. A literature review is presented.