Três artigos sobre a coluna na distrofia muscular de Duchenne.
Reino Unido – três artigos sobre a coluna na distrofia muscular de Duchenne estão nesta edição da Journal of Bone and Joint Surgery.
No primeiro os autores estudaram a função pulmonar a longo prazo após a cirurgia de escoliose. Eles observaram uma perda progressiva da função pulmonar mas em uma velocidade menor a observada antes da cirugia.
No segundo artigo eles analisaram a densitometria óssea da coluna em pacientes que iriam se submeter a cirurgia de escoliose e observaram que os pacientes com doença neuromuscular apresentam mais osteoporose do que os que apresentam escoliose por outras causas.
No terceiro artigo os autores descrevem uma nova técnica para correção da escoliose que poderia ter vantagens em relação a técnica convencional (menor tempo de cirurgia e menor sangramento). Os resumos em inglês dos três artigos pode ser lido abaixo:
1 )(IN PRESS: Journal of Bone and Joint Surgery – British Volume, Orthopaedic Proceedings Vol 88-B, Issue SUPP II, 228, 2006) SCOLIOSIS SURGERY IN DUCHENNE MUSCULAR DYSTROPHY: THE EFFECT ON RESPIRATORY FUNCTION
P.M. Whittingham-Jones, S. Molloy, G. Edge and J. Lehovsky – UK
Background: There are conflicting reports regarding the effect of scoliosis surgery on respiratory function in Duchenne Muscular Dystrophy (DMD)1,2. Galasko et al2 found that the Percentage Predicted Forced Vital Capacity (%PFVC), remained static for thirty six months following surgery, in patients with DMD that underwent spinal stabilisation for scoliosis. The aim of the current study was to support or refute the above finding in a large series of patients with DMD.
Methods: A retrospective analysis of data on 55 consecutive patients with DMD that underwent single stage posterior surgical correction for scoliosis. We analysed the data of 55 boys with DMD who underwent scoliosis surgery between 1990 and 2002. Age at surgery, pre-operative Cobb angles, pre-operative %PFVC, and post-operative %PFVC at 6 months, 12-18 months and 2–3 years were collected. We documented the pre-operative Cobb angle ± SD to assess the difficulty level of our surgical cases. Percentage PFVC was used as our outcome measure to assess respiratory function. The mean pre-operative %PFVC was compared to the post –operative mean %PFVC at three different time intervals; at 6 months, 12 to 18 months and at 2 to 3 years.
Results: The mean age was 14.6 years (range 11.2–18yrs). The mean pre-operative Cobb angle was 65.4 degrees ± 14.8. The mean %PFVC pre-operatively was 33.9 ± 10.4. The mean post-operative %PFVC’s were: 6 months (29.1 ± 10.4), 12 to 18 months (27.6 ± 12.1) and 2 to 3 years (25.4 ± 8.7). Therefore the mean % PFVC following surgery at 6 months, 12 to 18 months and 2 to 3 years decreased from the mean pre-operative % PFVC by 4.8%, 6.3% and 8.5% respectively.
Conclusion: The natural history of patients with DMD is a gradual decline in respiratory function. In the current study the mean post –operative %PFVC was less than the mean pre-operative %PFVC at 6 months, 12 to 18 months and at 2 to 3 years post surgery. Our series would suggest that respiratory function declines post-operatively, even in the short term, in patients with DMD that undergo spinal stabilisation. The decline in respiratory function in our study was progressive over the 3 year follow up period.
2) (IN PRESS: Journal of Bone and Joint Surgery – British Volume, Orthopaedic Proceedings Vol 88-B, Issue SUPP II, 232, 2006) BONE DENSITOMETRY IN PATIENTS WITH DIFFERENT TYPES SCOLIOSIS
M Al-Maiyah, J Mehta, D Fender and M J Gibson – UK
Background: To evaluate bone mineral density in patients with scoliosis of different causes and compare it to the expected values for the age, gender and body mass.
Methods: A Prospective, observational case series. From October 2003 to December 2004, Bone Mineral Density (BMD) of patients with different types of Scoliosis was recorded. Patients listed for corrective spinal surgery in our institute were included in the study (Total of 68 patients). BMD on lumbar spine and whole body was measured by DXA scan and recorded in form of Z-scores. Z-scores = number of Standard Deviations (SD) above or below age matched norms; it is age and gender specific standard deviation scores. Data collected using the same DXA scan equipment and software.
There were 29 patients with Adolescent Idiopathic Scoliosis and 7 patients with congenital or infantile scoliosis. Z-scores from patients with neuromuscular scoliosis also included, 10 patients with cerebral palsy and 11 with muscular dystrophies (mainly Duchenne MD). There were also 3 patients with Neurofbromatosis and 8 patients with other conditions (miscellaneous). Outcome measures were bone mineral density in patients with different types of scoliosis in form of Z-scores.
Results: Bone mineral density was significantly lower than normal for the age, gender and body mass in all patients with neuromuscular scoliosis; whole body z-score in group with cerebral palsy was –1.00 and –1.30 in muscular dystrophies group. Lumbar spine BMD was even lower in lumbar spine, mean z-score, – 4.51 in cerebral palsy and –2.36 in muscular dystrophies (mainly Duchenne MD). In idiopathic Scoliosis group mean BMD was markedly lower than normal for the age, gender and body mass, mean z-score = – 1.87, however whole body BMD was within the normal range, mean z-score = +0.124. Similar results were found in congenital and infantile scoliosis group, mean lumber z-score= – 1.36 and whole body z-score, – 0.30. In patients with neurofibromatosis, there were low BMD on spine, mean z-score was –1.19 while whole body z-score was + 0.19. In group of patients with other miscellaneous causes of scoliosis or syndromic scoliosis lumbar mean z-score= –2.22 and whole body mean z-score was –1.67.
Conclusion: This study showed that BMD on spine was lower than normal for the age, gender and body mass in all patients with scoliosis and the condition was even worse in neuromuscular and sydromic scoliosis. There was no correlation between spine BMD and whole body BMD. Spine BMD was lower than normal in almost all patients even when whole body BMD was within normal range. Thus we believe that DXA scan is a useful adjunct in the preoperative assessment of scoliotic patients prior to spinal surgery
3) (IN PRESS: Journal of Bone and Joint Surgery – British Volume, Orthopaedic Proceedings Vol 88-B, Issue SUPP II, 269, 2006) EVALUATION OF SINGLE ROD FUSION TECHNIQUE FOR SCOLIOSIS SECONDARY TO DUCHENNE MUSCULAR DYSTROPHY.
R Gul, D Farah, M Murphy, J Lunn and D McCormack – Dublin
Introduction: Duchenne’s Muscular Dystrophy (DMD) is a progressive sex linked recessive disease, predominantly involving skeletal muscle. Scoliosis is almost universal in patients with DMD. Surgical stabilization carries a significant risks and complications with peroperative mortality of <6%. Cardiopulmonary complications along with severe intraoperative blood loss requiring massive blood transfusion are the major cause of morbidity
Aim: To evaluate the efficacy of single rod fusion technique in reducing the peroperative and post operative complications especially blood loss, duration of surgery and progression of curve
Material & Methods: Retrospective review – 14 patients with scoliosis secondary to DMD with an average age of 14.5 years (range, 11–17) underwent single rod fusion technique using Isola rod system and pelvic was not included in fixation. Blood loss was measured directly from the peroperative suction and post operative drainage, indirectly by weighing the swabs. Vapour free hypotensive anesthesia was used in all case. Progression of curve was monitored over a period of five years.
Results: The mean operative time was 110 min (range, 80 – 180). The average blood loss was 1.6L (range, 0.7 – 5). The mean follow up was 32 months (range, 4 – 60). There was no progression noticed in the curve on follow up. Two patients develop complications, one had loosening & migration of the rod, required revision and superficial wound infection treated with intravenous antibiotics.
Conclusion: In our experience, single rod stabilization is a safe and quick method of stabilizing the spine in DMD with less blood loss and complications compared to traditional methods.
