The end product of transglutaminase crosslinking: simultaneous quantitation of [Nepsilon-(gamma-glutamyl) lysine] and lysine by HPLC-MS3.

Transglutaminases catalyze the formation of Nepsilon-(gamma-glutamyl) isodipeptide crosslinks between proteins. These enzymes are thought to participate in a number of diseases, including neurological disease and cancer. A method associating liquid chromatography and multiple stage mass spectrometry has been developed for the simultaneous quantitation of [Nepsilon-(gamma-glutamyl) lysine] isodipeptide and lysine on an ion trap mass spectrometer. Highly specific detection has been achieved in MS3 mode. The method includes a derivatization step consisting of butylation of carboxylic groups and acetylation of amide groups, a liquid-liquid extraction, and a 19-min separation on a 100x2.1-mm Beta-basic C18 column with an acetonitrile gradient elution. 13C6-(15)N2 isotopes of the isodipeptide and the lysine serve as internal standards. The assay was linear in the range of 50 pmol/ml to 75 nmol/ml for the isodipeptide and the range of 10 nmol/ml to 3.5 micromol/ml for the lysine, with correlation coefficients greater than 0.99 for both ions. Intra- and inter-day coefficients of variation ranged from 3.5 to 15.9%. The method was successfully applied to human biological samples known to be crosslinked by transglutaminase such as cornified envelopes of epidermis, fibrin, and normal and Huntington disease brain.

Targeted ablation of the murine involucrin gene.

Involucrin is synthesized in abundance during terminal differentiation of keratinocytes. Involucrin is a substrate for transglutaminase and one of the precursors of the cross-linked envelopes present in the corneocytes of the epidermis and other stratified squamous epithelia. These envelopes make an important contribution to the physical resistance of the epidermis. We have generated mice lacking involucrin from embryonic stem cells whose involucrin gene had been ablated by homologous recombination. These mice developed normally, possessed apparently normal epidermis and hair follicles, and made cornified envelopes that could not be distinguished from those of wild-type mice. No compensatory increase of mRNA for other envelope precursors was observed.

Influence of anatomic site and age on the replication and differentiation of rat adipocyte precursors in culture.

Using a propagating cell culture system of adipocyte precursors from 70-400-g rats, we explored the possibility that regional variations in properties of adipose tissue may reflect site-specific characteristics intrinsic to the cells, rather than extracellular influences. Initially, studies were made of the nature of the fibroblastlike cells from perirenal adipose tissue stroma. Using colony-forming techniques, it was shown that these cells were adipocyte precursors; each confluent colony that was derived from a single cell displayed differentiated adipocytes. This characteristic was evident in cells from rats of all ages and persisted during secondary culture. At all ages of rats studied, perirenal cells replicated more rapidly than epididymal precursors, e.g., for 179-g rats the population-doubling times were 19.3 +/- 0.7 vs. 25.5 +/- 1.2 h (means +/- SEM, P less than 0.03). With aging of the rats, the replication rate of their perirenal cells decreased progressively. Under clonal conditions, the colony size distribution of both perirenal and epididymal precursors revealed heterogeneity in their capacity for replication, perirenal cells showing greater proliferation. These also differentiated more extensively by morphologic and enzymatic criteria. Age and site had effects that persisted through many cell generations; however, high-fat feeding had no perpetuating influence. The dissimilar properties of perirenal as compared with epididymal precursors may reflect differences in regulation of gene expression. The data are also compatible with a later development in embryological life of perirenal tissue. We suggest that the composition of the adipocyte precursor pool is an important determinant of the growth of adipose tissue that occurs in response to a nutrient load. Interregional or interindividual variation in composition may explain regional and individual differences in fat accumulation.

Id3 prevents differentiation of preadipose cells.

We have studied the expression of the Id1, Id2, and Id3 genes during adipose differentiation of 3T3-F442A cells. All three Id mRNAs are present in preadipose cells, but the mRNA for Id3 is the most abundant. All three Id mRNAs sharply decline in the course of adipose differentiation, and their virtual disappearance precedes differentiation. The decrease in Id2 and Id3 is associated with adipose differentiation rather than with growth arrest since it is not observed in 3T3-C2 cells, a fibroblast line with a very low susceptibility to adipose conversion. The decline in Id2 and Id3 mRNAs is associated with a reduced transcription rate of the two genes. Id1 mRNA is reduced in amount during adipose conversion of 3T3-F442A cells, but the decrease is also observed in resting 3T3-C2 cells and is associated with very little decrease in transcription of the gene. Addition of fresh serum reactivates Id3 gene expression in quiescent 3T3-C2 cells but not in adipose 3T3-F442A cells. Stably transformed preadipose cells expressing an Id3 cDNA under the control of a viral promoter are virtually unable to differentiate. We postulate that the Id3 protein is a negative regulator of fat cell formation and presumably acts by preventing an as yet unidentified basic helix-loop-helix protein from activating the program of differentiation.

[Adult lateral meniscus]. / Le ménisque latéral de l'adulte.

Meniscal lesion does not mean meniscectomy and this is particularly true for the lateral meniscus. The reputation of mildness of the meniscectomy is usurped. The rate of joint space narrowing after lateral meniscectomy is of 40% at a follow-up of 13 years compared to 28% for the medial meniscus (symposium SFA 1996). Several arguments explain those results: biomechanical: the lateral meniscus contributes to the congruence; particularly the lateral meniscus is the zone where antero-posterior translational during knee flexion is 12 mm. The pejorative effects of lateral meniscectomy have conducted, more though to the medial meniscus, to the concept of meniscal economy. Lateral meniscectomy must be as partial as possible. Particularly, a discoid meniscus presenting a complete tear should be treated by a meniscoplasty in order to shape the meniscus in a more anatomic form than a total meniscectomy. Lateral meniscectomy is indicated in complex or horizontal cleavage, symptomatic, on stable knees. A particular case is the cyst of the lateral meniscus. It is a cystic subcutaneous formation, usual consequence of a horizontal cleaved meniscus of which the particularity is that it opens besides the articulation. The strategy must not consist in the isolated treatment of the cyst. This pathology should be addressed by an arthroscopic meniscectomy reaching the meniscosynovial junction at the level of the cyst. Meniscal repair must be proposed every time if possible. Criteria of reparability are better studied on MRI. Preoperatively MRI is the first choice radiological exam. Two essential indications can be held back: the vertical peripheral longitudinal lesion is on the non-vascularized area, and the horizontal cleaving of the junior athlete (if the cleaving remains purely intra meniscal). Meniscal repair is highly performed when the meniscal tear is associated to a rupture of the ACL (simultaneous reconstruction of the LCA). Postoperative outcome is different of that of a "simple" arthroscopic meniscectomy. The healing process being slow, it suits to protect the suture by a splint in the first month, and with an exclusion of sports with knee torsion during 6 months. Functional results (absence of secondary meniscectomy) and anatomical results (reality of the cicatrisation) are good in 77% of cases (symposium of the French Society of Arthroscopy 2003) at a follow-up of 55 months. Survivorship analysis indicates that majority of the failures occur within two years: this testifies a default of primary cicatrisation. At the studied follow-up, meniscal repair was efficient to protect the cartilage. Lateral meniscus results are better that medial meniscus one. Those data support indications: All suspicion of meniscal lesion must have an MRI preoperatively to confirm the lesion, to localize her and to search criteria of reparability; All vertical longitudinal peripheral lesions can and must be repaired especially in young patients and children; All horizontal cleaving of the junior athletes should be treated by open repair; surgical abstention must be proposed when the lesion is non symptomatic, or when lesion is limited and associated to an ACL tear (in that case isolated ACL reconstruction is proposed), or when clinical symptoms are minimal; Meniscectomy, always arthroscopic, is proposed for a symptomatic lesion in the avascular zone or for a deep horizontal cleavage or a complex tear; Tear of the discoid meniscus should be treated by meniscoplasty. A painful knee after lateral meniscectomy might be due to a too limited initial meniscectomy: an iterative meniscectomy may be indicated or lateral femorotibial arthritis, especially after subtotal or total meniscectomy. In this last case and after failure of usual medical treatment such as viscosupplementation surgery may be indicated. Osteotomy in order to unload the lateral femorotibial compartment gives a partial response as the shearing forces remain. This osteotomy is indicated only if the lower limb axis is normal or in valgus. Meniscal allograft is an option in young patients in grade I or II arthritis. Results are promising. Rene Verdonk's series show a survivorship analysis of 75% at 7 years. Early diagnosis of a postmeniscectomy syndrome before cartilaginous lesions occur is essential for an adapted treatment. In conclusion, lateral meniscectomy are less frequent than those of the medial meniscus but their prognosis is less favorable. They should be early diagnosed (MRI). Treatment options are various: abstention, meniscectomy, and repair. Painful post lateral meniscectomy syndrome may be treated by a new surgical option: meniscal allograft.

[Osteochondritis dissecans of the femoral condyles: report of 892 cases]. / L'ostéochondrite disséquante des condyles fémoraux.

PURPOSE OF THE STUDY: Osteochondritis rarely involves the femoral condyles. Discovery in this localization raises several questions concerning the nature of the articular cartilage, the potential for spontaneous healing, and, in the event of a free fragment, the outcome after its loss or repair. MATERIAL AND METHODS: This multicentric study included 892 pediatric and adult cases, the cutoff between two series being defined by fusion of the inferior growth plate. We excluded medical or surgical osteochondritis, cases involving the patella, osteochondral fractures, juvenile polyosteochondrosis, adult osteonecrosis, and osteochondritis beginning after the age of 50 years. RESULTS: Mean age at diagnosis was 16.5 years. Mean age at treatment onset was 22 years. Pain was the predominant symptom. 80% of cases were unilateral and 70% involved the medial condyle. The anatomic lesions were different in adults, showing more advanced degradation. At diagnosis, Bedouelle stages Ia and IIb constituted 80% of the cases observed among children while in adults, 66% were Bedouelle stages IIb to IV. Outcome was very good for the majority of children with Hughston clinical stage 4 while half of the x-rays were Hughston stage 3 and 4. There were thus a large percentage of children with abnormal xrays whose disease history was not yet terminated. In the adult series, the percentages of Hughston 3 and 4 was about the same as clinically. The x-rays were rarely perfectly normal since half of the clinical stage 3 patients were noted in stage 4. An abnormal x-ray with a very good clinical presentation was observed in a very large proportion of patients. DISCUSSION: It is difficult to interpret the plain x-ray and identify patients with a potentially unfavorable prognosis. We defined three radiographic classes: defect, nodule and empty notch. The Bedouelle classification uses information from all available explorations, particularly MRI and arthroscopy. Numerous therapeutic methods are used. Interruption of sports activities is the first intention treatment for children. Data in the literature and the findings of this symposium do not demonstrate any beneficial effect of immobilization on healing compared with simple abstention from sports activities. Transchondral perforation is a simple operation with low morbidity. In 85% of cases, it was used for lesions with an intact joint cartilage considered stable in 96% of cases. Healing was achieved in six months for 48% if the growth plate had not fused. The fragment was fixed in 43% of the cases with a loose cartilage fragment. Outcome was fair but degraded with the state of the joint cartilage and thus the stability of the fragment. Fixation must stabilize the fragment but not prevent further consolidation via osteogenesis. This is why deep perforations are drilled beyond the ossified area and additional osteochondral grafts are used. The Wagner operation gives less satisfactory results than more complicated procedures. Removal of a sequestrum is a simple, minimally invasive procedure with an uneventful postoperative period, but in the long term it favors osteoarthritic degradation, especially when performed in adults. Mosaic grafts give good mid term results. Morbidity is low especially if the grafts are harvested above the notch. The question of chondrolysis around the grafts was beyond the scope of this study. Chondrocyte grafting is difficult to accomplish and is expensive. The mid term results are good for large lesions. Osteotomy is logical only in the event of early stage osteoarthritic degradation. DECISION ALGORITHM IN CHILDREN AND ADOLESCENTS: If the plain x-ray reveals a defect (class I), simple interruption of sports activities should be proposed. Two situations can then develop. First, in a certain number of patients, the pain disappears as the defective zone ossifies progressively. Complete cure is frequent before the age of 12 years. In the second situation, the knee remains painful and the x-ray does not change or worsens to a class II nodular formation. In this case an MRI must be obtained to determine whether the joint cartilage is normal. There are two possibilities. First, the osteochondral fragment is viable and most probably will become completely re-integrated, particularly if the lesion is far from the growth plate. Necrosis is the other possibility. Transchondral perforations are needed in this case. If on the contrary the cartilage is altered, there is little hope for spontaneous cure. Arthroscopy may be needed to complete the exploration. Fragments, especially if there is a large surface area, must be fixed. Perforations to favor revascularization are certainly useful here. In the last situation (class III), the fragment wobbles on a thin attachment or has already fallen into the joint space. This is the type of problem generally observed in adults. The decision algorithm in adults is the same as in children for the rare nodular aspects (class II). There could be a discussion between transcartilage perforation and fixation. If there are a large number of fragments, fixation may not be fully successful and the lesion might be considered class III. For class III lesions, three operations can be used: removal of the sequestrum, mosaic bone-cartilage grafts, or autologous chondrocyte grafts. At the same follow-up, mosaic grafts give better results than excision of sequestra. It may be useful to remove sequestra in a limited number of situations: if there is just a small area of osteochondritis, the lesion is old and partially healed, or the zone is non weight-bearing. For other lesions, we favor mosaic grafts. We still do not have enough follow-up to assess the long-term outcome with these mosaic grafts, but simple excision clearly favors osteoarthritic degradation. Can chondrocytes grafts be compared with mosaic grafts? Chondrocyte grafts have been used for very large lesions and have given results similar to mosaic grafts. It might also be possible to combine fixation of a loose fragment and a mosaic graft. LESSONS FROM THIS STUDY: 1) The prognosis of osteochondritis is better before than after fusion of the growth plate but the lesion does not always heal in children. 2) Presence of osteochondritis requires complementary anatomic and functional exploration to determine the stability and the vitality of the fragment. 3) Attention must be taken to perform transchondral perforations early enough, particularly in children. 4) Screw fixation is not always sufficient. The trophicity of the fragment and its blood supply must be improved. 5) Mosaic grafts are preferable to excision of the fragment. 6) Chondrocyte grafts will be more widely used in the future.

["Isolated" injury of the posterior cruciate ligament. Surgical treatment of isolated posterior cruciate ligament tears: a multicentric retrospective study of 103 patients]. / Traitement chirurgical d'une rupture isolée du ligament croisé postérieur: résultats d'une série rétrospective multicentrique de 103 patients.

PURPOSE OF THE STUDY: We present a retrospective multicentric series of carefully selected patients presenting "isolated" laxity of the posterior cruciate ligament. MATERIAL AND METHODS: The series included 103 patients who were reviewed clinically (with a dedicated review chart) and radiographically with measurement of posterior laxity (Telos 15 kg). RESULTS: In these patients with an isolated injury of the PCL (without associated injury of the peripheral ligament) DISCUSSION: The short follow-up of this series (four years) does not enable an assessment of the risk or benefit of PCL ligamentoplasty for arthrosic knees.

Posterolateral knee reconstruction.

Injury to the cruciate ligaments of the knee commonly occurs in association with posterolateral instability, which can cause severe functional disability including varus, posterior translation, and external rotational instability. Failure to diagnose and treat an injury of the posterolateral corner in a patient who has a tear of the cruciate ligament can also result in the failure of the reconstructed cruciate ligament. There seems to be a consensus of opinion that injury to the posterolateral corner, whether isolated or combined, is best treated by reconstructing the posterolateral corner along with the coexisting cruciate ligament injury, if combined. Commonly proposed methods of reconstructing the posterolateral corner have focused on the reconstruction of the popliteus, the popliteofibular ligament, and the lateral collateral ligament. The aim of this conference is to describe the posterolateral corner reconstruction technique and to provide an algorithm of treatment.

Expansion of mouse involucrin by intra-allelic repeat addition.

Involucrin, loricrin and the small proline-rich proteins (SPRRs) are precursors of the cornified envelope of terminally differentiated keratinocytes. The genes for these proteins are closely linked on mouse chromosome 3. Each of the proteins is encoded by a single exon and is largely composed of a segment of short tandem repeats. No size polymorphism of either loricrin or the SPRRs was observed. In contrast, involucrin was found in at least eight polymorphic forms of different size with molecular weights ranging from 51 to 82kDa. Two classes of involucrin alleles were identified. Size polymorphism of involucrin has resulted from the recent expansion of the segment of repeats in one class of alleles, but not in the other. In expanding alleles, repeats were added at a precise location within the segment of repeats, in a 5'-to-3' direction. A study of a large number of allele-specific markers, located on both sides of the site of repeat addition, revealed no evidence for recombination between any of the alleles examined. Expansion of the segment of repeats of the gene for mouse involucrin must result from an intra-allelic process controlled by a cis-acting element, active in one class of alleles, and inactive in the other.

The involucrin gene of the tree shrew: recent repeat additions and the relocation of cysteine codons.

The coding region of the involucrin gene of Tupaia glis has been cloned and sequenced. It resembles the involucrin coding region of other non-anthropoid mammals in possessing a segment of related, short tandem repeats at a defined location, but in Tupaia, there has been recent serial duplication of a repeat into which a cysteine codon had earlier been introduced. As a result of the duplication, there is a total of as many as six cysteine codons in the segment of repeats, a number larger than for any other species yet examined. In Ratttus there has been a comparable but independent addition of cysteine codons, and both Tupaia and Rattus have eliminated an otherwise conserved cysteine codon 75 located close to but outside the segment of repeats. In Tupaia, this elimination probably occurred by gene conversion. Also independently, the gene of Canis has added cysteine codons to the segment of repeats but has not yet lost cysteine 75. It is proposed that the gain and the loss of cysteine codons are parts of a multi-stage program of cysteine relocation.

Lipogenic and mitogenic effects of insulin during conversion of Ob17 cells to adipose-like cells.

Chronic exposure to insulin of confluent cells of a preadipocyte clonal line (Ob17) leads to an acceleration of their development into adipose cells. The short-term effects of insulin have been examined by the stimulation of [14C] alpha-aminoisobutyrate uptake and the long-term effects by the increase in the activity levels of several lipogenic enzymes and in the intracellular triacylglycerol content. These metabolic effects of insulin occur within a physiological range of concentrations (EC50 congruent to 1 nM). As compared to insulin, dose-response curves obtained with proinsulin on these parameters show at least a 10-fold decrease in sensitivity of the cells. In contrast, the growth-promoting effects of both insulin and proinsulin occur at supraphysiological concentrations (EC50 greater than 300 nM). This mitogenic response is likely mediated through binding to receptors of insulin-like growth factors. Our data demonstrate that long-term effects of insulin on lipid synthesis can be dissociated from its effect on cell growth. Therefore the Ob17 cell line should be a useful model to study the role of insulin in the regulation of lipid synthesis in adipose cells.

Coupling growth arrest and adipocyte differentiation.

The complete differentiation program of preadipose cells can be divided into early and late events. The expression of early markers takes place at growth arrest (G1/S boundary), whereas that of late markers, leading to terminal differentiation, takes place after a limited number of mitoses of early marker-containing cells. Only terminal differentiation requires the presence of growth hormone and triiodothyronine and results in the formation of triacylglycerol-filled, nondividing cells. The events of adipose cell differentiation which take place in vitro allow a better understanding of the development of adipose tissue in vivo.

Adipocyte precursor clones vary in capacity for differentiation.

Adipocyte precursor populations derived from rat perirenal or epididymal fat were found to be composed of clones varying in capacity for differentiation. Perirenal tissue contained a greater proportion of those clones that differentiated extensively. It is hypothesized that differences between regions and individuals in growth of adipose tissue may be due to differences in the frequency within adipocyte precursor pools of clones with unusual capacities for replication and differentiation.

The expanded CAG repeat associated with juvenile Huntington disease shows a common origin of most or all neurons and glia in human cerebrum.

We have analyzed the size of the expanded poly(CAG) associated with juvenile Huntington disease in the cerebra and the cerebella of five patients. The expanded poly(CAG) was always longer in the cerebrum than in the cerebellum, but the difference in size varied from patient to patient. Except for one patient who possessed an unusually large expansion, very little heterogeneity of size was detected within the cerebrum or within the cerebellum. The larger size of the expanded poly(CAG) in cerebrum must therefore have resulted from a single expansion event that took place early in cerebral development. In both cerebrum and cerebellum, the size of the expanded allele of gray matter was identical to that of white matter. We conclude that most if not all neurons and glia of cerebrum are descended from a common bipotent precursor, which segregated early in neurogenesis from the lineage leading to cerebellar neurons and glia.

[Anterio-lateral extra-articular tenodesis of the knee using a short strip of fascia lata]. / Plastie extra-articulaire antéro-latérale du genou utilisant une ténodèse courte au fascia lata.

This study describes a lateral extra-articular tenodesis using a short strip of ilio-tibial band. The tenodesis consists of a 12 x 75 mm strip of iliotibial band remaining attached to the Gerdy's tubercle. An isometric point in the region of Krackow's point F-9 is determined with a callipers. The strip of iliotibial band is twisted by 180 degrees to enhance its isometry. Then it is either onlay with a screw and spiked washer on the F-9 point, or within a transverse tunnel drilled through the lateral femoral condyle, from the F-9 point, using and interference screw. Thus, the uses of a short ilio-tibial band tenodesis with a 180 degrees twist in combination with a BPTB reconstruction of the ACL, leads to similar results that the combined classic Lemaire tenodesis, with shorter skin incision, shorter graft harvesting, and at least on the biomechanical standpoint a better graft isometry.

[Anterior cruciate ligament reconstruction: patellar tendon autograft versus four-strand hamstring tendon autografts. A comparative study at one year follow-up]. / Comparaison à un an de recul des reconstructions du ligament croisé antérieur par transplant libre de tendon rotulien ou par droit interne demi-tendineux à quatre brins.

PURPOSE OF THE STUDY: The purpose of our study was to compare outcome at one year after anterior cruciate ligament reconstruction for chronic laxity using the patellar tendon autograft or four-strand hamstring tendon autografts. MATERIAL AND METHOD: This non-randomized study included 129 consecutive patients operated on between October 1996 and September 1998. Ninety patients were available for assessment at one year: 50 in the patellar tendon group and 40 in the hamstring tendon group. The two groups were comparable for all criteria except sex. A single operator assessed all patients using the IKDC 93 chart. Laxity was measured by comparison with the healthy knee using the KT1000 at maximal manual tension. Preoperative laxity was 8.0 +/- 3.0 mm in the patellar tendon group and 7.6 +/- 3.0 in the hamstring tendon group. All ligamentoplasties were performed arthroscopically using a blind femoral tunnel. The patellar tendon was fixed with two metallic interference screws and the four-strand hamstring autografts with two different methods: an RCI(R) interference screw or a cortical system associating a femoral Endobutton(R) and tibial fixation with a bicortical tibial screw. Lateral tendonesis was performed with the fascia lata in 60% of the patients in the patellar tendon group and in 45% of those in the hamstring tendon group. Rehabilitation exercises were initiated early and were the same in the two groups. RESULTS: Overall results were satisfactory in more than 80% of the patients in both groups. The final IKDC score was significantly better in the patellar tendon group and subjective patient satisfaction was better in the hamstrings group. Residual pain was significantly less pronounced in the hamstrings tendon group (p=0.004). Laxity was improved significantly better in the patellar tendon group: average residual laxity=2.7 +/- 2.1 mm versus 4.5 +/- 2.8 mm (p=0.03) in the hamstrings tendon group; hard stop at the Lachman test in 96% of the patellar tendon group and 78% in the hamstrings tendon group (p=0.007). Residual laxity was significantly less pronounced in the women in the patellar tendon group. There was no significant difference in laxity by type of fixation in the hamstrings tendon group. Recovery in terms of level of activity and type of sport was the same in the two groups. DISCUSSION: These two surgical techniques provide good functional outcome at one year with better control of laxity with patellar tendon autografts and better relief of pain with four-strand hamstrings autografts. Longer follow-up would be useful to assess laxity long after hamstring reconstruction. We compared the type of transplant and the fixation method together as a single unity, but progress in four-strand hamstring autograft fixation will certainly allow even more optimal results and improved correction of laxity. In our opinion, the patellar tendon autograft remains the gold standard for high-performance athletes practicing a contact-pivot sport, but both types of ACL reconstruction are most useful. We select patients for four-strand hamstring tendon reconstruction as a function of age, sex, and type of sports activities.

[Arthroscopic release for knee joint stiffness after total knee arthroplasty]. / Arthrolyse arthroscopique du genou pour raideur après prothèse totale.

PURPOSE OF THE STUDY: Overall, the results of total knee replacement surgery are quite excellent, both with regard to pain and range of motion. Pain relief is obtained in more than 95% of the cases and more than 90% of the patients are able to bend their knee over 90 degrees. Nevertheless, in a small number of cases, stiffness can be an impairment. MATERIAL AND METHODS: Between 1992 and 1998, six arthroscopic releases were performed on six patients who had undergone total knee replacement. The six patients suffered from unacceptable stiffness. The average age of the patients was 68.5 years, and the time elapsed from implantation to arthroscopy averaged 24 months (6 months to 6 years). Average follow-up was 19 months (6 to 96 months). The six stiff knees were treated with arthroscopic debridement of fibrous tissue around the patella and quadriceps tendon (to improve extension) and by arthroscopic division of the medial and lateral retinacula (to address flexion). A gentle manipulation was carried out following lysis of adhesions, using a slight pressure on the tubercle to avoid fractures and disruptions of the extensor mechanisms. Postoperatively, immediate physical therapy was performed including continuous passive motion and active muscular contraction. Early weight bearing was allowed. RESULTS: The average flexion contracture decreased from 9 degrees prior to arthroscopy to 2.5 degrees at last follow-up. Average flexion increased from 70 to 100 degrees. Maximal improvement was obtained at three months. DISCUSSION: Results were found to be quite good, with a final knee score of 93 and a function score of 92 (following International Knee Society scoring). CONCLUSION: Arthroscopic release following total knee replacement complicated by joint stiffness provides a satisfactory increase in range of motion.

[Results of Marshall-MacIntosh reconstruction according to 3 scoring systems (ARPEGE, Lysholm, IKDC). 90 cases reviewed with at least a one-year follow-up]. / Etude des résultats de l'intervention de Marshall-MacIntosh selon trois systèmes d'évaluation (ARPEGE, Lysholm, IKDC). 90 cas revus avec un recul d'au moins un an.

The "International Knee Documentation Committee" (IKDC) evaluation form was created in 1992 in order to make easier the comparison of the results obtained in the U.S. and Europe in the knee ligament surgery using various procedures. In order to evaluate the performances of the IKDC system, it has been applied to the analysis of the results of 90 Marshall-MacIntosh ACL augmented-reconstructions, all having at least one year follow-up, and compared to the ARPEGE and Lysholm-Tegner systems. All 3 systems have in common a functional activity scale, nevertheless only the IKDC system takes into consideration the ligament examination. In this system, the assessment of the overall result is based on the combination of 4 parameter groups (patient subjective assessment, symptoms, range of motion, ligament examination). The lowest grade within a group determines the group grade. The worst group grade determines the final evaluation. According to the ARPEGE system, 79 per cent of good and excellent results were observed. This percentage increased up to 92.5 per cent with the Lysholm-Tegner system, and up to 82 per cent with the IKDC system. There was a positive and significant correlation between the IKDC system and the two others. The final result, when evaluated with the IKDC system, first depends on the ligament examination, while with the two other systems, pain appears to be the predominant parameter.

[Radiologic and MRI evaluation of intra-articular ligamentoplasty using a patellar tendon. Correlations with anatomical results]. / Evaluation radiologique et IRM des ligamentoplasties intra-articulaires utilisant le tendon rotulien. Corrélations avec les résultats anatomiques.

INTRODUCTION: the purpose of this study was to evaluate the influence of the graft positioning on the clinical outcome and MRI signal of the graft as well, following ACL reconstruction using the central one-third of the patellar tendon. MATERIAL AND METHODS: twenty one patients having a chronic anterior instability sustained a modified Marshall-Mac Intosh procedure, while 15 having a subacute torn ACL had an ACL reconstruction using a free bone-patellar tendon-bone graft. The patients were retrospectively reviewed with a 1.8 year average follow-up (1-3 years). The clinical result was evaluated through the comparative range of motion, the residual laxity as measured with the KT 1000 arthrometer, and the pivot shift test. The roentgenographic analysis was performed from AP and ML views, made first on one-leg standing with the knee at 30 degrees of flexion, and then in "zero" extension with active quadriceps contraction. Lines were drawn to visualise the location of the tibial and femoral tunnels in relation to the tibial plateaus and the roof of the intercondylar notch represented by the Blumensaat line. The analysis of the AP IRM views of the graft allowed to discriminate between homogeneous and heterogeneous graft signals. RESULTS: on lateral roentgenograms of normal knees it was found that the Blumensaat line crossed the surface of the medial tibial plateau at its anterior third, at 30 +/- 9 per cent (20-40 per cent range), demonstrating the variability of the intercondylar roof inclination. The range of motion was normal in 22 patients (group 1), 8 patients had a flexion deficit (group II), and 6 exhibited an extension deficit (group III). The residual laxity was similar in each group (p > 0.05). When comparing group III to group I, patients from group III had a tibial tunnel significantly more anterior with regard to the Blumensaat line (p < 0.02). In group III, all patients exhibited an heterogeneous MRI graft signal (p < 0.05), and the angle between the intraarticular part of the graft and the tibial tunnel was higher (p < 0.001). These findings were not observed in group II where the location only of the femoral tunnel seemed to influence the flexion deficit (p > 0.05). DISCUSSION AND CONCLUSION: this study demonstrated that the location of the tibial tunnel with regard to the roof of the intercondylar notch, when the knee is in "zero" extension, was the most relevant parameter controlling the extension deficit resulting from a graft impingement. No relation was found between the tibial tunnel location with regard to the tibial plateaus and the mobility deficit. Graft impingement also was always associated with an heterogenous graft MRI signal. CLINICAL RELEVANCE: when reconstructing the ACL care must be taken when inserting the K-wire aimed to guide the tibial drill, to obtain a proper position with regard to the roof of the intercondylar notch. The K-wire location must be checked in "zero" extension. Intra-operative X-rays may help.

[Reliability of the KT-1000 arthrometer (Medmetric) for measuring anterior knee laxity: comparison with Telos in 147 knees]. / Fiabilité de l'arthromètre KT-1000 pour la mesure de la laxité antérieure du genou: comparaison avec l'appareil Télos à propos de 147 genoux.

PURPOSE OF THE STUDY: The purpose of this study was to compare the reliability and the reproducibility of both the KT-1000 arthrometer (Medmetric) and Telos for measuring anterior knee laxity. The Telos was used as the reference technique. MATERIAL AND METHODS: Criteria for inclusion were preoperative anterior knee laxity, normal contralateral knee, and intra-articular surgery to reconstruct the anterior cruciate ligament. Between January 1st, 2000 and October 31st, 2001, 147 patients were operated on for knee instability using an autograft (BPTB or hamstring tendons). For each patient, comparative measurements were made for both knees preoperatively and postoperatively with an average follow-up of 16 months. Measurements with the KT-1000 apparatus were made with forces of 67 N, 89 N, 134 N and manual maximal force. For the Telos, a force of 250 N was used as recommended by the manufacturer. We also evaluated intraobserver variation between the two devices. RESULTS: The anterior translation preoperatively as measured by the KT-1000 at 89N was 4.2 +/- 2.4 mm and 6.3 +/- 2.5 mm at maximal manual force. The result for Telos was 3.0 +/- 3.6 mm. The data scatter obtained with Telos was wider than with KT-1000 (p<0.03). The sensitivity of Telos was 72% with 28% false negatives. With KT-1000, sensitivity increased as tensile force increased. Sensitivity was 65% at 89N, 73% at 134N and 92% at maximal manual force. The concordance between the KT1000 and Telos data was low for either preoperative (10%) or postoperative (30%) measurements. DISCUSSION AND CONCLUSION: In this study, the results of sensitivity and reproducibility as well as the minimal scatter of the values demonstrated the reliability of KT-1000 for measuring anterior translation of the knee. We recommend routine use of the KT-1000 device for measuring knee laxity. The low sensitivity and the high rate of false negative observed with Telos raises the question of its use a reference technique.