Efectos de la tensión y transfixión del cartílago de crecimiento con diferentes hilos de sutura: estudio experimental en conejos / Effects of compression and transfiction of the physes by different sutures: experimental study in rabbits

Introducción: El objetivo de este estudio fue determinar las alteraciones que se producen en el cartílago epifisario femoral distal en conejos al ser rodeado o atravesado por distintos hilos de sutura. Materiales y métodos: Se utilizaron 24 fémures distales de 18 conejos neozelandeses de 7 a 8 semanas, que se dividieron en cuatro grupos de 6 conejos cada uno. En el grupo 1 se atravesó la fisis rodeando el cóndilo femoral externo con Prolene® 3.0, en el grupo 2a con Vicryl® 3.0, en el 2b con lino 60 y en el grupo 3 no se la atravesó sino que fue rodeada con Vicryl® 4.0. Resultados: a) Imaginológicos: en todos los casos se encontró acortamiento del miembro operado; el grupo 3 fue el más afectado (promedio 9,75 mm). Hubo nueve casos de luxación medial rotuliana, cuatro en el grupo 2, dos en el grupo 1 y tres en el grupo 3. Cinco pacientes presentaron deformidad en varo, una en el grupo 1, dos en el 2 y dos en el 3. b) Anatomopatológicos: en todos los grupos se reconoció la placa epifisaria con sus cinco capas adecuadamente formadas. En ninguno se observó reacción inflamatoria ni de células gigantes de tipo cuerpo extraño; tampoco barras óseas; sólo en el grupo 2b se halló tejido conectivo alrededor del material exógeno (hilo). Conclusiones: El daño producido en el cartílago de crecimiento se debió principalmente al efecto de la presión sobre este, con independencia del material de sutura utilizado debido a que los resultados anatomopatológicos no revelaron alteraciones en su normal configuración y radiológicamente se encontró acortamiento femoral y en varo; estos fueron mayores en el grupo 3, en el cual la presión ejercida sobre la epífisis fue mayor y en todo su diámetro sin atravesarla, mientras que en los grupos 1, 2a y 2b sólo se ejerció presión en el cóndilo femoral externo atravesando la epífisis.

Background: To determine changes in the distal femoral physis when surrounded or transfixed with different suture materials. Methods: Twenty-four distal femoral physes of 18 New Zealand rabbits (7-8 weeks old) were divided into four groups of six rabbits each. In group 1 a Prolene 3.0 suture was used. Group 2 was divided in two, number 2a used a Vicryl 3.0 suture, and number 2b a linen 60 suture; and in group 3 a Vicryl 4.0 suture was used. The suture in groups 1, 2a and 2b transfixed the physis surrounding the lateral femoral condyle. In group 3 the physis was surrounded, not transfixed.Results: Imaging: In all cases the limb was shorter, group 3 was the most affected (average, 9.75 mm.). There were 9 cases of medial patellar dislocation (4 in group 2, 2 in group 1 and 2 in group 3). Five cases of varus deformity were found (1 in group 1, 2 in group 3 and 2 in group 2). Pathological anatomy results: The five layers of the physis were adequately preserved in all cases. No inflammatory response or foreign body-type giant cells, or epiphyseal fusions were found. Connective tissue around the suture was found only in group 2b. Conclusions: Damage to the physis was mainly caused by the amount of pressure exerted on it regardless of the suture material used in each case because the pathological anatomy results did not reveal any abnormalities, and radiologically, a greater femoral varus and shortening was found in group 3 in which the pressure on the physis was greater in all its diameter without transfixing the physis. In groups 1, 2a and 2b the pressure was exerted around the lateral femoral condyle transfixing the physis.

Response of the growth plate of uremic rats to human growth hormone and corticosteroids

Children with chronic renal failure in general present growth retardation that is aggravated by corticosteroids. We describe here the effects of methylprednisolone (MP) and recombinant human growth hormone (rhGH) on the growth plate (GP) of uremic rats. Uremia was induced by subtotal nephrectomy in 30-day-old rats, followed by 20 IU kg-1 day-1 rhGH (N = 7) or 3 mg kg-1 day-1 MP (N = 7) or 20 IU kg-1 day-1 rhGH + 3 mg kg-1 day-1 MP (N = 7) treatment for 10 days. Control rats with intact renal function were sham-operated and treated with 3 mg kg-1 day-1 MP (N = 7) or vehicle (N = 7). Uremic rats (N = 7) were used as untreated control animals. Structural alterations in the GP and the expression of anti-proliferating cell nuclear antigen (PCNA) and anti-insulin-like growth factor I (IGF-I) by epiphyseal chondrocytes were evaluated. Uremic MP rats displayed a reduction in the proliferative zone height (59.08 ± 4.54 vs 68.07 ± 7.5 æm, P < 0.05) and modifications in the microarchitecture of the GP. MP and uremia had an additive inhibitory effect on the proliferative activity of GP chondrocytes, lowering the expression of PCNA (19.48 ± 11.13 vs 68.64 ± 7.9 percent in control, P < 0.0005) and IGF-I (58.53 ± 0.96 vs 84.78 ± 2.93 percent in control, P < 0.0001), that was counteracted by rhGH. These findings suggest that in uremic rats rhGH therapy improves longitudinal growth by increasing IGF-I synthesis in the GP and by stimulating chondrocyte proliferation.

Effect of Ciprofloxacin on growing cartilage in albino Rat pups

Administration of quinolone therapy is controversial during growing age as stated by earlier worker. The flroquinolones are currently not indicated for young children, because of arthropathy and adverse effect on growing cartilage shown by studies. However the effects of ciprofloxacin on epiphyseal growth plate has remained undocumented. This study is therefore, undertaken to determine the risk of ciprofloxacin administration an growing cartilage by prospective experimental animal study model using Wistar albino rat pups. Ciprofloxacin was administered to newly born Wistar albino rat pups with a doze of 20mg/kg body weight intraperitonealy twice a day from day-1 to day-14 after birth. The animals were sacrificed by deep ether anesthesia. The limbs were disarticulated from axial skeleton, soft tissue was removed. The intact bone mean length in millimeter of right and left humerus and femur was measured with the help of electronic vernier caliper and bones were fixed in 10% buffered farmalin. Decalcification was done in 10% nitric acid and 10% formic acid changes. After paraplast embeding, 4 mm thick longitudinal sections of the proximal long bones were cut by a rotary microtome. Routine staining with haemotoxylin and eosin was performed. Histomorphometry was done measuring the thickness of epiphyseal cartilage and was compared with similar value of control animals. The results were statistically analysed to find out the significance. The ciprofloxacin induces a mordanting effect as abviated by increased basophilia. Our study reveales that cirprofloxacin administration in the newly born pups decreased the width of epiphyseal growth plate cartilage by 10.43% in humerus and 4.72% in femur as compared to the growth of control cartilage. The decrease in the width was brought about mainly by the reduced count of the proliferative cells in the proliferative zone and the diminuation in the average size of the hypertrophic condryocytes in the hypertrophic zone. The reserve zone has become markedly reduced in thickness. The ciprofloxacin post-natal administration effected growth plate retardation by inhibiting the mitosis in the proliferative zone and also effected the mean length of humora and femora leading to reduction in limb length of rat pups

Effects of ethylene glycol monomethyl ether [EGME] on male albino rat liver, kidney and femoral bone

Twenty male albino rats [100-120] gm body weight were used in this study and divided into a control and an experimental group, ten rats for each. Each rat from the experimental group was given, orally 80 mg / kg. body weight EGME every other day for 21 days. 5 mm. thick paraffin sections from the liver, kidney and decalcified femoral bone for each rat were prepared and stained by Hx and E, alcian blue PAS and Mallory triple stain. The diameter of epiphyseal cartilage was also measured both of control and experimental group. EGME induced marked histopathological alteration in the liver and kidney. Hepatic lesions were characterized by mild increase of mononuclear cell infiltration along the hepatic cords, dilation of some hepatic sinusoids and swollen hepatocytes. Renal lesion was in the form of glomerular hypercellularity and lobulation, also the renal tubules were dilated and had irregular luminal border. The femoral bone revealed atrophy of epiphyseal cartilage with disturbing cartilage columns and widening of the spaces of the matrix between them. Alcianophilic staining ability of the chonchocytes and matrix markedly declined. The trabecular bone also was markedly reduced in size. It was concluded that one should be cautious while using EGME containing materials such as some paints, cleaners, dyes, inks, resins and varnishes

Transfixaçäo da placa de crescimento do coelho por um parafuso / Insertion of a screw across the growth plate in rabbit

Foram estudados os efeitos da inserçao de um parafuso através da cartilagem de crescimento do fêmur de coelhos. Vinte e oito coelhos albinos da raça Nova Zelândia tiveram um parafuso de osso cortical (14,0mm x 2,0mm) inserido através da superfície articular do côndilo femoral medial, cruzando a cartilagem de crescimento, até a metáfise. O fêmur esquerdo foi mantido como controle. Depois de quatro semanas os parafusos foram removidos em todos os animais. Em 13 coelhos o orifício do parafuso foi deixado vazio. Em 15 animais, um fio liso de Kirschner foi colocado no orifício do parafuso de modo a preenchê-lo completamente. Os animais foram seguidos com radiografias dos membros posteriores e sacrificados após cinco semanas da segunda cirurgia. Em todas as radiografias foram medidos os comprimentos e o ângulo frontal dos pares de fêmures. Foram realizados cortes histológicos frontais da extremidade distal dos fêmures. Na maioria dos casos o fêmur operado estava mais curto e apresentava deformidade em varo, quando comparado com o fêmur nao operado. Depois da remoçao houve recuperaçao parcial do comprimento e do ângulo, em ambos os grupos. Entretanto, a angulaçao em varo nos animais em que o parafuso foi substituído pelo fio de Kirschner foi mais acentuada. Os achados microscópicos mostraram que o orifício do parafuso foi preenchido por osso neoformado (ponte óssea), mais isso nao ocorreu quando o parafuso foi substituído pelo fio de Kirschner. Em todos os casos havia alteraçoes degenerativas avançadas na cartilagem de crescimento do côndilo medial.

Distraçäo da placa epifisária: estudo experimental em coelhos / Distraction of the epiphyseal growth plate: experimental study in rabbits

Estudo experimental foi realizado na extremidade distal do fêmur em nove coelhos com doze semanas de vida, com o propósito de identificar o mecanismo básico envolvido na distraçao da fise, quando empregada taxa de distraçao de 1,0mm, numa única vez ao dia, e de avaliar a viabilidade do segmento alongado. Os animais foram divididos em três grupos, de acordo com a época em que forma mortos (final do alongamento, 30 e 60 dias após o alongamento). Os resultados radiográficos mostraram, em todos os espécimes, diástase da epífise da metáfise (GAP) entre o segundo e o quinto dias após o início do alongamento. Sessenta dias após o período distracional, ficou evidenciado radiograficamente que todo o segmento alongado estava ossificado. Os resultados histológicos obtidos mostraram que o mecanismo básico envolvido em alongamento foi epifisiólise distracional, produzida por fratura através da zona hipertrófica entre a camada degenerativa e a de calcificaçao provisória da placa epifisária. Após 60 dias do término do alongamento, a placa epifisária havia retornado à espessura normal e sua morfologia apresentava características semelhantes às da fise normal. O segmento alongado estava ocupado por tecido ósseo. A distraçao de 1,0mm, numa única vez ao dia (espifiólise distracional) da placa epifisária, provou ser eficaz na obtençao de alongamento ósseo em coelhos, pois levou à formaçao de um osso novo com características morfológicas e funcionalmente semelhantes ao osso normal. Portanto, esse método de alongamento é mais uma opçao para correçao de discrepâncias entre os membros.

Hallazgos morfológicos en el cartílago de crecimiento de niños desnutridos / Morphological findings in growth cartilage in malnourished children

Se presentan los hallazgos morfológicos del cartílago de crecimiento tibial en doce niños fallecidos, once de los cuales eran desnutridos, nueve de ellos con déficit de crecimiento lineal. Se encontraron alteraciones condrocitarias consistentes en desorganización y espaciamiento de las columnas condrocitarias con tendencia a la formación de "nidos" de condrocitos e irregularidades en la formación de tejido oesteoide. Estas alteraciones correlacionaron particularmente con el porcentaje de déficit de talla y la edad, puntualizando los efectos de la cronicidad del déficit nutricional