Mohamed E. Abdel-Wanis

Effect of Timing of Pulmonary Metastases Identification on Prognosis of Patients With Osteosarcoma: The Japanese Musculoskeletal Oncology Group Study

PURPOSE The prognostic value of the time of identification of lung metastasis was investigated in 280 patients with metastatic lung osteosarcoma as a multi-institutional study of the Japanese Musculoskeletal Oncology Group. PATIENTS AND METHODS The 280 patients with lung metastasis were divided into four groups: group 1, patients with lung metastasis identified at initial presentation; group 2, those with lung metastasis identified during preoperative chemotherapy; group 3, those with lung metastasis identified during postoperative chemotherapy, and group 4, those with lung metastasis identified after completion of treatment. Survivals of the four groups were compared. Additionally, the effects of number of metastatic nodules, metastasectomy, and the effect of chemotherapy on the primary tumor on survival of the four groups were analyzed. RESULTS There were 46 patients in group 1, 30 in group 2, 94 in group 3, and 110 in group 4. The overall 2-year survival rates from the time of identification of lung metastasis were 33%, 31%, 24%, and 40% for groups 1, 2, 3, and 4, respectively, whereas the 5-year survival rates were 18%, 0%, 6%, and 31%, respectively. Patients in group 4 thus demonstrated significantly better prognosis than any of the other patients (P <.0001). CONCLUSION Time of identification of lung metastasis is an important prognostic factor. In terms of clinical behavior, groups 2 and 3 are completely different than group 4. These data ensure the need to stratify stage III osteosarcomas into subgroups according to the time of diagnosis of lung metastases. To improve the survival of osteosarcoma patients, new treatment modalities should be introduced into the treatment armamentarium for lung metastasis from osteosarcoma, especially in groups 1, 2, and 3.

Influence of acute shortening on the spinal cord: an experimental study.

Study Design. Morphometric changes of the spinal cord and influence on spinal cord-evoked potentials and spinal cord blood flow and postoperative function of hind limbs were studied in various degrees of acute spinal column shortening in dogs. Objectives. To study the morphometric and physiologic effects of acute spinal column shortening on the spinal cord. Summary of Background Data. The technique of acute spinal column shortening is sometimes applied for correction of spinal deformity, total en bloc spondylectomy operation, or other diseases. However, safe limits and physiologic effects of acute spinal column shortening have not yet been described. Methods. Total spondylectomy of T13 was performed in dogs after spinal instrumentation placed 2 levels above and 2 levels below the spondylectomy level. Spinal column was gradually shortened until the lower endplate of T12 contacted the L1 upper endplate (maximum of 20 mm). When any morphologic change of the dural sac or the spinal cord was observed, the length of shortening was measured. Spinal cord-evoked potentials were recorded on the exposed dura mater following epidural stimulation at the C7 level in 8 dogs. Spinal cord blood flow was measured during shortening in 6 dogs. Hindlimb function was evaluated 2 weeks after operation in 10 dogs. Results. No morphometric changes occurred in the dural sac and the spinal cord until shortening of 7.2 ± 1.7 mm (n = 6). From 7.2 ± 1.7 to 12.5 ± 1.1 mm shortening, the dural sac was deformed, whereas the spinal cord maintained its shape. Shortening more than 12.5 ± 1.1 mm buckled the dural sac, and the spinal cord kinked itself and was compressed by the buckled dura in its concave side (n = 6). No changes could be detected in spinal cord-evoked potentials in 5 or 10 mm of shortening. Spinal cord-evoked potential changes were recorded in the 2 of 6 dogs with 15 mm of shortening. At 20 mm of shortening, spinal cord-evoked potential abnormality was observed in 4 of 6 dogs. At shortening of 5, 10, 15, and 20 mm, spinal cord blood flow was 146 ± 10%, 160 ± 21%, 102 ± 17%, and 93 ± 7% of the control (29.2 ± 7.9 mL/100 g/min, n = 6), respectively. All 3 dogs with 10 mm ofshortening had normal hindlimb function 2 weeks after operation. One of the 3 dogs with 15 mm of shortening had paraparesis. Three of the 4 dogs with 20 mm of shortening had also paraparesis after operation. Conclusions. Acute spinal column shortening can be characterized into 3 phases. Phase 1, safe range: occurred during shortening within one-third of the vertebral segment and is characterized by no deformity of the dural sac or the spinal cord. Phase 2, warning range: occurred during spinal shortening between one-third and two-thirds of the vertebral segment and is characterized by shrinking and buckling of the dural sac and no deformity of the spinal cord. Phase 3, dangerous range: occurred after shortening in excess of two-thirds of the vertebral segment and is characterized by spinal cord deformity and compression by the buckled dura. Spinal shortening within the safe range increases spinal cord blood flow.

Osteosarcoma around the knee: Intraepiphyseal excision and biological reconstruction with distraction osteogenesis

In 11 patients juxta-articular osteosarcoma around the knee was treated by intraepiphyseal excision of the tumour and reconstruction of the bone defect by distraction osteogenesis. Preoperative and postoperative chemotherapy was given to eight patients with high-grade tumours. The articular cartilage of the epiphysis and a maximum of healthy soft tissues were preserved. Distraction osteogenesis was then carried out. The mean gain in length was 9.7 cm. Full function of the limb was preserved in all except one patient, with a mean follow-up of 53.8 months. Treatment of juxta-articular osteosarcomas around the knee with joint preservation and biological reconstruction using distraction osteogenesis can give excellent functional results.

Total en bloc spondylectomy for spinal metastases in thyroid carcinoma.

OBJECT Thyroid carcinoma generally has a favorable prognosis, and patients rarely present with distant metastases. Authors of several studies have proposed piecemeal resection for spinal metastases in thyroid carcinoma; however, few have analyzed the impact of local curative surgery such as total en bloc spondylectomy (TES) for thyroid carcinoma. The purposes of the present study are to determine the strategy of surgical treatment for spinal metastases of thyroid carcinoma and to evaluate the surgical results of and the prognosis associated with TES. METHODS Twenty-four cases of spinal metastases were retrospectively reviewed. The patients included 16 women and 8 men, with a mean age of 60.7 years. Histological examination showed follicular carcinoma in 15 cases, papillary carcinoma in 8, and medullary carcinoma in 1. Total en bloc spondylectomy was performed in 10 cases; debulking surgery, such as piecemeal excision or eggshell curettage, was performed in 14. The average follow-up time was 55 months (12-180 months). RESULTS Four patients had no evidence of disease, 8 were alive with the disease, and 12 had died of the disease. The overall survival rate from the time of surgery was 74% at 5 years. Patients with visceral metastases had a significant, higher risk of death. The survival rate of patients following TES was 90% at 5 years, which was higher than the rate in patients who underwent debulking surgery (63%). However, no significant difference was observed between the 2 types of surgery. There was a local recurrence after debulking surgery in 8 (57%) of 14 cases. Because of the recurrences, reoperation was required after a mean of 41 months. In contrast, there was a local recurrence after TES in only 1 (10%) of 10 cases. The difference between debulking surgery and TES regarding local recurrence was statistically significant. CONCLUSIONS Total en bloc spondylectomy with enough of a margin provided favorable local control of spinal metastases of thyroid carcinoma during a patients lifetime.

Deformity correction followed by lengthening with the Ilizarov method.

Deformity combined with shortening of 18 lower limb segments of 17 patients was treated with the Ilizarov method. Limb lengthening was done at the same treatment (monofocal treatment) or a separate osteotomy (bifocal treatment) was done after acute or gradual correction of the deformity using the Ilizarov hinge system. The external fixation time, amount of deformity correction, length gained, and incidence of complications were examined. Results were compared between monofocal versus bifocal treatment groups and between femoral versus tibial procedures. The average deformity corrected was 22.3°, and the average lengthening was 44.4 mm. The external fixation index was 49.3 days/cm on average, ranging from 24.4 to 90 days/cm, and the mean duration of external fixation was 198 days, ranging from 77 to 352 days. Major complications requiring surgical treatment, such as premature consolidation and fracture, were seen in four patients. There were no statistically significant differences between the results for monofocal and bifocal treatment or treatment indices for femoral and tibial operations. The Ilizarov method was very effective for treatment of limb deformity combined with shortening. Monofocal treatment might be better if the total amounts of lengthening required are short to reduce surgical invasion. Longer treatment indices for tibial operations could not be verified from the current study.

Cannulation of simple bone cysts

We describe a consecutive series of 26 patients with simple bone cysts who were treated by curettage, multiple drilling and continuous decompression by the insertion of either a cannulated screw or a pin. In the first 15 patients we used titanium cannulated screws (group 1) and in the next 11 a cannulated hydroxyapatite pin (group 2). Satisfactory healing was achieved in 12 patients in group 1 (80%) and in all in group 2. This technique seems to be a promising option for the treatment of simple bone cysts. The cannulated hydroxyapatite pin is recommended because of its higher success rate and the fact that it does not need to be removed.

Minimal curettage, multiple drilling, and continuous decompression through a cannulated screw for treatment of calcaneal simple bone cysts in children.

This report concerns a series of 12 patients with simple bone cysts of the calcaneus, who were treated between 1988 and 2000 by a minimal surgical intervention of curettage, multiple drilling and continuous decompression through insertion of a cannulated screw. Inserted screws were made of titanium in 8 cases and ceramics in 4 cases. The mean operative time was 58.8 ± 25.4 minutes, and complete healing was achieved in 11 cases after 9.2 ± 6.4 months. One patient needed an additional surgery for replacement of a titanium screw. Final results were excellent after a mean follow up of 91 ± 52.1 months. This series of patients represents one of the largest reported series of calcaneal simple bone cyst in conjunction with long-term follow-up. Our technique of minimal curettage, drilling and continuous decompression with a cannulated screw insertion is considered to be a good option for management of simple bone cysts of the calcaneus.

Osteosarcoma around the knee

In 11 patients juxta-articular osteosarcoma around the knee was treated by intraepiphyseal excision of the tumour and reconstruction of the bone defect by distraction osteogenesis. Preoperative and postoperative chemotherapy was given to eight patients with high-grade tumours. The articular cartilage of the epiphysis and a maximum of healthy soft tissues were preserved. Distraction osteogenesis was then carried out. The mean gain in length was 9.7 cm. Full function of the limb was preserved in all except one patient, with a mean follow-up of 53.8 months. Treatment of juxta-articular osteosarcomas around the knee with joint preservation and biological reconstruction using distraction osteogenesis can give excellent functional results.

Hypophosphatemic osteomalacia in neurofibromatosis 1: hypotheses for pathogenesis and higher incidence of spinal deformity

Osteomalacia is rarely encountered in association with neurofibromatosis 1, characterized by phosphate loss in the urine and its pathogenesis is still unknown. Incidence of spinal deformities in cases of neurofibromatosis 1 associated with osteomalacia seems to be high. Spinal deformities are unlikely to be due to osteomalacia itself. Melatonin deficiency was proposed to be present in cases of neurofibromatosis 1 and to be an operating factor in progression of spinal deformities. We might hypothesize that putative melatonin deficiency in cases of neurofibromatosis 1 might play a role in the pathogenesis of hyperphosphaturea by decreasing sodium-phosphate cotransport, increasing the level of cAMP, the un-antagonized effect of dopamine on phosphate reabsorption and increasing glucocorticoid levels. Parathyroid overactivity that may occur secondary to osteomalacia might have synergistic effects with dopamine and further exaggerate phosphate loss in urine. On the other hand, excess corticosteroid secretion would decrease nocturnal melatonin level. Moreover, in the presence of hypophosphatemia, hypercortisolism might further inhibit melatonin secretion that might lead to progression of spinal deformities in these cases.

Bone development in neurofibromatosis 1.

Bony abnormalities are common findings in cases of neurofibromatosis 1. We might hypothesize that neurofibromin, the protein encoded by the neurofibromatosis 1 gene, plays important roles in bone development. Loss of function of oligodendrocyte-myelin glycoprotein gene and increased activity of ras p21 might increase the level of c-fos proto-oncogene in bones with formation of fibrous dysplasia-like tissue. Also, increased ras p21 might disturb collagen I synthesis by osteoblasts. Moreover, increased ras activity might increase the mitogenic signals to the nucleus through mitogen-activated protein kinase (MAPK) and disturb the level of the transcription factor core-binding factor alpha(1) (Cbfa1). Abnormal fibrous tissue and neurofibromas formed at the site of pseudarthrosis might represent abnormal response of periosteal fibroblasts for injury, an effect simulating the response of skin fibroblasts in neurofibromatosis 1 to injury.