Surgical correction of spinal deformity in patients with congenital muscular dystrophy

Background  

Congenital muscular dystrophy (CMD), among the myopathic disorders is one form of flaccid neuromuscular disorder (NMD). Patients with NMD frequently develop progressive spinal deformity. For NMD patients who have a severe spinal deformity, sitting is often difficult and is accompanied by pain and breakdown of the skin. Spinal deformity surgery in these patients has been highly effective in stabilizing the spine, maintaining upright, comfortable sitting balance, and improving patients’ quality of life. However, many studies have reported significant rates of peri/postoperative complications in these patients. To our knowledge, there has been no study on the results of spinal deformity surgery in patients with CMD. The purpose of this study was to review the clinical and radiological results of spinal deformity surgery in this group of patients with CMD.     

Surgical management of severe scoliosis with high risk pulmonary dysfunction in Duchenne muscular dystrophy: patient function, quality of life and satisfaction

In a previous study, the authors reported the clinical and radiological results of Duchenne muscular dystrophy (DMD) scoliosis surgery in 14 patients with a low FVC of <30%. The purpose of this study was to determine if surgery improved function and QOL in these patients. Furthermore, the authors assessed the patients’ and parents’ satisfaction. %FVC increased in all patients after preoperative inspiratory muscle training. Scoliosis surgery in this group of patients presented no increased risk of major complications. All-screw constructions and fusion offered the ability to correct spinal deformity in the coronal and pelvic obliquity initially, intermediate and long-term. All patients were encouraged to continue inspiratory muscle training after surgery. The mean rate of %FVC decline after surgery was 3.6% per year. Most patients and parents believed scoliosis surgery improved their function, sitting balance and quality of life even though patients were at high risk for major complications. Their satisfaction was also high.     

Surgical management of severe scoliosis with high-risk pulmonary dysfunction in Duchenne muscular dystrophy

Between 2005 and 2007, 14 patients who had severe scoliosis in Duchenne muscular dystrophy (DMD) and a poor forced vital capacity (FVC) of <30% at admission underwent scoliosis surgery. FVC on admission was 21.6% (range, 16–27%). The patients were given respiratory muscle training using a pulmonary trainer (Threshold IMT, Philips Respironics, Inc.) for six weeks before operation. FVC increased to 26.2% (range, 22–31%) the day before operation. The mean preoperative scoliosis was 98° (range, 81°–130°). All patients underwent posterior fusion and all-screw construction and were extubated on the operative day. No patients developed any respiratory complications. The postoperative scoliosis was 34° (range, 20°–40°) (65%). FVC remained stable at six weeks after operation. FVC decreased to 19.8% (range, 16–25%) and the mean scoliosis was 35° (range, 23°–40°)(64%) at two years after operation. DMD patients with severe scoliosis and FVC considered too low to permit reasonable surgical risk could undergo surgery and could benefit from surgery.     

Autogenous iliac crest bone graft versus banked allograft bone in scoliosis surgery in patients with Duchenne muscular dystrophy

A total of 36 consecutive nonambulatory DMD patients underwent scoliosis surgery. Patients were divided into two groups: the autogenous iliac crest bone graft group (the ICBG group; 20 patients) and the allogenous bone graft group (the ALBG group; 16 patients). The mean preoperative curves measured 87° and 31° at the last follow-up in the ICBG group and 83° and 28° in the ALBG group. In the ICBG group, three (15%) patients had intraoperative sacroiliac joint penetration, five (25%) had iliac crest inner cortex penetration and three (15%) had postoperative prolonged wound drainage at the donor site. At three months after surgery, donor site pain caused by bone harvest was found in 50% with severe pain limiting their physical function and causing difficulties in sitting in a wheelchair in 40% of the patients, whereas patients in the ALBG group returned to their preoperative level of function soon after surgery.     

Existence of pyogenic spondylitis in Modic type 1 change without other signs of infection: 2-year follow-up

The relationship of Modic change to pain and inflammation remains to be unclear. Recently, some authors have reported that Modic type 1 signals are closely related to infection. However, if the patients do not have severe back pain, fever, or an abnormal blood profile, it is difficult to distinguish between common Modic change and infection. The purpose of this study was to examine the prevalence of pyogenic spondylitis in patients who showed Modic type 1 change without other signs of infection. Seventy-one patients with Modic type 1 change were evaluated (average age 55, 32 males and 39 females). X-ray and magnetic resonance imaging (MRI) were performed to investigate low-back pain and leg pain. Body temperature was measured and blood analysis (including white blood cell count and level of C-reactive protein) was conducted for all patents. All 71 patients with Modic type 1 change, but without other signs of infection were followed for 2 years. Low-back pain, X-ray, and blood analyses were performed every 3 months; and MRI was performed every year. Severe low-back pain or abnormal signs developed in four patients during the follow-up. Pyogenic spondylitis was diagnosed in three patients by symptoms, blood results, and imaging, and confirmed by biopsy. Two of the three patients were diabetic. A total of 4.2% of patients with Modic type 1 change, but without other signs of infection were diagnosed as having pyogenic spondylitis during the 2-year follow-up, therefore, it is important to consider this before treating Modic type 1 change.     

Primary sensory neurons with dichotomizing axons projecting to the facet joint and the low back muscle in rats

Background

Clinically, the origin of low back pain is unknown. The pain may originate from the lumbar muscles directly, or it may be referred pain from the spine. Dorsal root ganglion (DRG) neurons with dichotomizing axons have been reported in several species and are thought to be related to referred pain. However, these neurons, which have dichotomizing axons to the lumbar facet joints and to the lumbar muscle, have not been fully investigated.

Methods

Two neurotracers — 1,1′-dioctadecyl-3,3,3′,3′- tetramethyl-indocarbocyanine perchlorate (DiI) and fluorogold (FG) — were used in the present double-labeling study. DiI crystals were placed in the right L5/6 facet joint, and FG was applied to right multifidus muscles at the L5 level in 10 rats. Two weeks later, bilateral DRGs from L1 through L6 were harvested, sectioned, and observed under a fluorescence microscope.

Results

DiI-labeled DRG neurons innervating the L5/6 facet joint (5.17% of the total DRG neurons) were distributed from L1 to L6. FG-labeled DRG neurons innervating the lower back muscle (15.9% of the total) were also distributed from L1 to L6. Double-labeled DRG neurons were found from L1 to L6. The ratio of total double-labeled/total DiI-labeled DRG neurons was 17% and that of total double-labeled/total FG-labeled DRG neurons was 7%. Approximately 17% of all DRG neurons innervating the facet joints had other axons that extended to the lower back muscle.

Conclusions

This finding provides a possible neuroanatomical explanation for referred low back muscle pain from the lower facet joints.