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At least 505 records · Page 28Linked to original sources
PubMed1977

Fragmentation of the distal pole of the patella in spastic cerebral palsy.

Of eighty-five consecutive patients, thirteen to twenty years old, with spastic cerebral palsy involving one or both extremities (thirty-five patients seen at one institution and fifty, at another), four had roentgenographic evidence of fragmentation of the distal pole of the patella. In addition, three other patients with six spastic lower extremities, four of them with patellar fragmentation, were also included. In these seven patients, there were nine knees with patellar fragmentation, twelve knees with patella alta, nine with a flexion contracture, five that were painful, and four with changes in the tibial tubercle resembling those found in Osgood-Schlatter disease. Excessive tension in the quadriceps mechanism, usually in the presence of a flexion contracture, appeared to cause the lesions. Four of the fragmented patellae healed after hamstring release and correction of the flexion deformity.

Achilles Tendon↗
PubMed1997

Orthopaedic clinical note. Patella metastases: a case report.

Here we report the first noted case of a small cell carcinoma of the lung (oat cell carcinoma) presenting as metastases in the patella. Malignancies of the patella, primary or secondary, are rare. First presentation of a malignancy with metastases in the patella has only been recorded once previously.

Aged↗
PubMed1997

[Osteoid osteoma of the patella].

Osteoid osteoma is a primary, benign, bone tumor with a typical X-ray appearance. The diagnosis is usually straightforward when it involves the long bones of the leg. However it may occur in unusual locations, such as in flat and cancellous bones. The following case demonstrates the difficulty in diagnosing it in an extremely rare site. A 25-year-old woman with long-standing anterior, right knee pain had had 3 interventions: 2 diagnostic arthroscopies and a distal, femoral biopsy. Since there had been no improvement in her condition, the diagnosis of osteoid osteoma of the patella was suggested, supported by recent X-ray and scintigraphic findings. This rare condition was confirmed by biopsy of the upper pole of the patella, a procedure that was followed by complete recovery. 6 years later, she is now completely free of pain and has no clinical or X-ray evidence of recurrence. Review of the literature revealed only 5 previously reported cases of osteoid osteoma of the patella. All were diagnosed relatively late and in 1 the tumor was diagnosed only after total patellectomy. Diagnosis of these rare cases that mimic much more common causes of patello-femoral pain demands a high index of suspicion.

Adult↗
PubMed1997

[Prevention of hemorrhagic complications in the lateral retinacular section of the patella. A study of the lateral arteries of the knee applied to the prevention of knee hemarthrosis].

PURPOSE OF THE STUDY: Arthroscopic lateral retinacular release is one of the most employed procedures for patellar chondromalacia. A literature review show a complication rate of 10 to 18 p. 100 of postoperative hemarthrosis. This work aims to study the vessels anatomy of the lateral side of the knee in order to find anatomical landmarks allowing to avoid or coagulate them. MATERIAL AND METHODS: Thirty-three cadaver knees were dissected. Measures were made related to the lateral superior genicular artery and the lateral inferior genicular artery. A study using tracing-paper was also carried out. The main part of the work was more descriptive, studying anastomosis between the different arteries and veins location. RESULTS: Concerning the lateral superior genicular artery, measure analysis showed that this artery was always cut in lateral patellar retinaculum. This artery never runs more than one centimeter proximally to the base of patella, which is too insufficient to escape from lateral retinacular release. We noted the possibility of locating 90 p. 100 of lateral superior genicular arteries in a minimal distance of 15 mm, in front of the lateral proximal angle of the patella. Concerning the lateral inferior genicular artery, only a few arteries, protected in the meniscal wall in its early course, can remain intact. Two thirds of these arteries are very vulnerable running across the lateral side of the knee. The study of the tracing-papers confirmed topographic study measurements. The descriptive study emphasized the number and the importance of anastomoses between these different arteries. Each artery is flanked by two large satellite veins, which also attribute a veinous origin to a possible bleeding. DISCUSSION: The topographic study of the lateral inferior genicular vessels shows that their course varies. It seems necessary to avoid their division by performing the standard anterior lateral inferior arthroscopic portal proximally to these vessels. This can be realized at the beginning of the procedure through cutaneous transillumination. The lateral superior genicular vessels are always cut. They are nevertheless reachable through a small lateral incision of about 10 mm, distally to the lateral superior angle of the patella. 90 p. 100 at least of these arteries could be coagulated in such a way. We also emphasize the use of classical methods for the prevention of excessive venous bleeding, such as a compression dressing. CONCLUSION: Following this anatomical study, we suggest, as a supplementary precaution, a selective hemostasis of the lateral superior genicular vessels through a small incision associated with the location of the lateral inferior genicular vessels by cutaneous transillumination.

Arthroscopy↗
PubMed1996

Multiple cis-acting elements act cooperatively in directing trochoblast-specific expression of the alpha-tubulin-4 gene in Patella embryos.

During early embryogenesis of the mollusc Patella vulgata the alpha-tubulin-4 gene is specifically expressed in the differentiation process of a particular cell type, the trochoblasts. The 5' region of the gene has been analysed for elements that are required for the regulation of the cell-type-specific activation of the gene. In a functional assay, seven elements that play a role in the spatiotemporal activation of the gene were detected in the promoter sequence. They are not required all together at the same time. A core of two elements, together with two or three auxiliary elements, are sufficient in controlling trochoblast-specific expression of the gene in the Patella embryo. One of the core elements is always required, without it, the gene is not expressed at all. The other core element acts as a positive element in trochoblasts and as a negative element in non-trochoblasts and thus is involved in directing the cell-type specificity of expression. The seven elements act cooperatively, and at least some of them can substitute for each other. Sequence comparison revealed that six of the seven fragments contain the sequence element GTTAA, including one of the core elements. Both core elements seem to play a crucial role in the expression of the alpha-tubulin-4 gene during the differentiation process of trochoblasts in the Patella embryo. A model for the regulation of the cell-type specificity of the gene during trochoblast differentiation is proposed.

Animals↗
PubMed1997

Patella-tibial transfixation for posterior cruciate ligament repair and reconstruction: a biomechanical analysis.

The posterior cruciate ligament (PCL) restricts posterior translation of the tibia on the femur. Because flexion of the knee increases tension on the PCL, the knee is usually immobilized in extension after PCL repair or reconstruction. Patella-tibial transfixation (olecranization), however, has been proposed to reduce the tension on the PCL without requiring immobilization of the knee. The objective of this study was: (1) to evaluate the distribution of strain in the anterolateral and posterior oblique fiber bundles of the PCLs in eight cadaveric knees before and after olecranization and (2) to measure the patellofemoral contact pressures at various degrees of knee flexion. Olecranization significantly (P < 0.05) reduced the strain on the anterolateral fiber bundles of the PCL at 15 degrees -45 degrees of flexion. No significant strain reduction was observed in the posterior oblique fiber bundles. Patellofemoral contact pressures measured from digitized Fuji sensitive film indicated significantly increased contact pressures (P < 0.05) following olecranization from 0 degrees -60 degrees of knee flexion. Increased parapatellar soft tissue tightness limited knee flexion to 90 degrees and patella lift-off occurred at 75 degrees. Although olecranization of the patella does reduce strain on the intact PCL within a selected range of motion, the beneficial effect of allowing early motion may be negated by the potentially harmful effects imposed upon the patellofemoral articular cartilage by increased contact pressures.

Aged↗
PubMed2005

Magnetic resonance imaging of bilateral lateral congenital dislocations of unossified patellae.

We describe our experience using magnetic resonance imaging (MRI) to evaluate the unossified dislocated cartilaginous patella in a 6-year-old male patient with restricted extension and flexion deformity of both knees. MRI is used widely in the visualization of cartilage since it can show cartilage directly. In addition, FS FLASH 3D sequence has recently been accepted as a suitable sequence in the evaluation of hyaline cartilage. MRI makes it possible to evaluate ligamentous, tendinous, muscular, and cartilaginous structures as well as the abnormalities related to them. We applied this technique in our case and found it very effective in locating the unossified dislocated cartilaginous patella. We also observed structural changes such as bilateral lateral displacement of short quadriceps tendon inserting into diminutive patella, insertion of bilateral patellar tendons into anterolateral tibia, and a stretching of the medial collateral ligament associated with valgus stress.

Child↗
PubMed2004

Expression of a SoxB and a Wnt2/13 gene during the development of the mollusc Patella vulgata.

We cloned and analysed the expression of a SoxB gene ( PvuSoxB) in the marine mollusc, Patella vulgata. Like its orthologues in deuterostomes, after an early broad ectodermal distribution, PvuSoxB expression only persists in cells competent to form neural structures. In the post-gastrulation larva, PvuSoxB is expressed in the prospective neuroectoderm in the head and in the trunk. No expression can be seen dorsally, around the mouth and the anus, or along the ventral midline. We also report the expression of a Wnt2/13 orthologue ( PvuWnt2) in Patella. After gastrulation, PvuWnt2 is expressed in the posterior part of the mouth, along the ventral midline and around the anus. This expression seems to be complementary to that of PvuSoxB in the trunk. We suggest the existence of a fundamental subdivision of the Patella trunk ectoderm into midline (mouth, midline, anus) and more lateral structures.

Amino Acid Sequence↗
PubMed2005

Choosing your implant: cementless, patella sparing, and posterior cruciate ligament retaining.

Clinical results of total knee arthroplasty with osteointegration techniques for fixation of the femoral and tibial components in a series of 192 patients (255 knees) followed up for 15 to 18 years are comparable with the best series reported with cemented fixation. Although functional scores declined as the patients aged, pain scores did not worsen, and the mechanical failure rate remained low through follow-up. Preservation of the posterior cruciate ligament offered knee stability, especially in knees that required ligament balancing. Results with unresurfaced patellas in total knee arthroplasty are superior to resurfaced patellas in qualities related to quadriceps function such as stair climbing, likely because of femoral component design. Femoral implants with a shallow patellar groove and wide intercondylar notch produce the highest stresses on the unresurfaced patella. Those with deeper patellar grooves and supporting lateral flange surfaces have low contact stress similar to that of the normal patellofemoral joint.

Arthroplasty, Replacement, Knee↗
PubMed2005

Osteochondral injury to the mid-lateral weight-bearing portion of the lateral femoral condyle associated with patella dislocation.

We report on a series of 7 patients who presented with patella dislocation and were found to have osteochondral fracture (OCF) of the weight-bearing portion of the lateral femoral condyle either through preoperative studies or by identification of the lesion during arthroscopy. Treatments included open reduction and internal fixation, debridement, and microfracture of the lateral femoral condyle. Although not as common as osteochondral injuries to the medial facet of the patella and the anterior lateral portion of the lateral femoral condyle, osteochondral injury to the weight-bearing portion of the mid-lateral femoral condyle does occur with patella dislocation and was recognized in these 7 patients. The surgeon who treats known patellofemoral dislocations should be aware of this uncommon lesion to ensure detection and appropriate treatment. Also, in the case of uncertainty about the mechanism of injury, recognition of this lesion should heighten suspicion of patellofemoral dislocation.

Adolescent↗
PubMed2006

Spontaneous patella dislocation in Rubinstein Taybi Syndrome.

A patient with Rubinstein Taybi Syndrome ( RTS) was found to have spontaneous patella dislocation and spontaneous patella reduction. Clinical examination revealed ligamentous laxity and reducible patella. Open reduction and stabilization with semitendinosus tenodesis were done. Surgical treatment should not be put off because of the delay in the ability to walk in addition to the poor psychomotor abilities of children with RTS. This case is of particular interest as it represents an unusual type of dislocation that has not been reported in the literature so far.

Child, Preschool↗
PubMedDate not supplied

A lophotrochozoan twist gene is expressed in the ectomesoderm of the gastropod mollusk Patella vulgata.

The twist gene is known to be involved in mesoderm formation in two of the three clades of bilaterally symmetrical animals: viz. deuterostomes (such as vertebrates) and ecdysozoans (such as arthropods and nematodes). There are currently no data on the spatiotemporal expression of this gene in the third clade, the lophotrochozoans (such as mollusks and annelids). To approach the question of mesoderm homology across bilaterians, we decided to analyze orthologs of this gene in the gastropod mollusk Patella vulgata that belongs to the lophotrochozoans. We present here the cloning, characterization, and phylogenetic analysis of a Patella twist ortholog, Pv-twi, and determine the early spatiotemporal expression pattern of this gene. Pv-twi expression was found in the trochophore larva in a subset of the ectomesoderm, one of the two sources of mesoderm in Patella. These data support the idea that twist genes were ancestrally involved in mesoderm differentiation. The absence of Pv-twi in the second mesodermal source, the endomesoderm, suggests that also other genes must be involved in lophotrochozoan mesoderm differentiation. It therefore remains a question if the mesoderm of all bilaterians is homologous.

Amino Acid Sequence↗
PubMed2003

Effect of femoral component design on unresurfaced patellas in knee arthroplasty.

Three total knee designs were evaluated to test the hypothesis that femoral component design affects the clinical and mechanical functions of the unresurfaced patella after total knee arthroplasty. Patients with the Ortholoc II, Advantim, and Profix femoral components were followed up for as many as 14 years and revision rate, anterior knee pain, and generalized knee pain were compared. A laboratory protocol was devised to evaluate pressure in the patellofemoral joint of knees from cadavers with a pressure-sensitive transducer using the same three designs at various degrees of knee flexion. Thirty Ortholoc II knee components were followed up for 14 years. Nineteen patients (63%) had severe anterior knee pain and 15 patients (50%) had reoperation to resurface the patella within 2 years. Two hundred one patients (222 knees) with Advantim components were followed up for 10 years and 305 patients (330 knees) with Profix components were followed up for 5 years. No patients with these two knee designs had severe anterior knee pain or reoperation for patellar resurfacing. A significantly higher rate of mild anterior knee pain was seen in the patients with Advantim components than in the patients with Profix components. No apparent relationship was seen between the severity of patellar wear found at the time of surgery and the incidence of anterior knee pain. Patients with rheumatoid arthritis receiving either the Advantim or Profix knee component performed as well as patients with osteoarthritis when the patella was not resurfaced. Pressure was significantly higher in the patellofemoral joints of the laboratory knee specimens with Ortholoc II components than in the specimens with either the Advantim or Profix components. The specimens with Advantim components had significantly higher pressure than did the specimens with normal knees, and the specimens with Profix components differed little from those with normal knees.

Arthritis, Rheumatoid↗
PubMed1998

[A biomechanical study of anterior cruciate ligaments reconstructed with patella tendons augmented by absorbable artificial materials. A biomechanical study in rabbits].

The purpose of this study was to investigate the biomechanical properties of anterior cruciate ligament (ACL) reconstruction using an absorbable artificial material in rabbits. Experimental studies were carried out on 58 New Zealand white rabbits. After total resection of ACL, 22 knees were reconstructed with patella tendons alone (non-augmented group) and 27 knees with patella tendons augmented by polyglactin 910 mesh (augmented group). The animals were sacrificed for biomechanical testing at 0, 2, 4, 6, 8, 12 and 24 weeks, respectively, after the operation. The stiffness of reconstructed ACL in the augmented group showed a mean of 26.58 +/- 5.78 N/mm at 8 weeks, and that of the non-augmented group 16.47 +/- 11.34 N/mm. There were significant differences between the augmented and non-augmented groups (p < 0.05). The ultimate load and energy of the reconstructed ACL were also significantly higher in the augmented group than in the non-augmented group at 8 weeks. The mean elastic module was higher in the augmented than in the non-augmented group, but the differences were not significant. The mean tan delta of both groups was significantly higher than that of the normal ACL at 24 weeks. These results suggests that polyglactin 910 mesh induces earlier maturation of transplanted patella tendons biomechanically, and may be a useful material for ACL reconstruction.

Animals↗
PubMedDate not supplied

Structural and in vivo mechanical characterization of canine patellar cartilage: a closed chondromalacia patellae model.

The purpose of this project was to study the relationship between the structure of the patellar cartilage and its response to static compressive loading with a closed chondromalacia patellae model. An animal model was used to induce degeneration of the patella that was monitored quantitatively and qualitatively as a function of time. Ten adult mongrel dogs had their left patellofemoral groove replaced by a customized metallic implant covered with a thin film of polyethylene for periods of 3 months (five dogs) and 6 months (five dogs). An indenter was designed to perform mechanical indentation testing on the patellar cartilage in situ. The animals were anesthetized and the response of patellar cartilage to a static compressive load of 4.5 MPa was monitored for 20 min and its relaxation after load removal for 20 min. Indentation tests were performed every 3 months of the implantation period. At the end of the implantation period, the patellae were processed for histology, and sections were stained with Safranin-O indicative of the proteoglycans content. Macroscopically, no apparent degeneration or fibrillation of the patellar surfaces was observed after 3 or 6 months of implantation. However, the patellar surface showed a change in coloration after 6 months. A 17 +/- 3% and 37 +/- 8% deformation of the cartilage were calculated for the 3-month and 6-month specimens, respectively. Histologically, a progressive loss of proteoglycans was observed in the matrix as a function of implantation time. These results indicated that an increase in cartilage compliance is associated with an intrinsic remodeling of the cartilage matrix and that these changes might occur without external signs of degeneration and can be quantified.

Animals↗
PubMedDate not supplied

A case report of patella cubiti.

Report of a patella cubiti in a patient with juvenile rheumatoid arthritis. The genesis of this patella is unknown up to now. The following hypotheses are discussed: 1. Persistent separation of the non fused epiphyseal bone centre with consecutive independent development. 2. Avulsion of the epiphysis due to muscle tension. 3. Epiphysitis as cause of the new formed patella.

Adult↗