Ozaki, Toshifumi

We evaluated the surgical problems encountered during treatment of 14 patients with malignant tumors originating in the pelvic region at our department. The tumor involved the iliac bone in 6 patients, the ischial bone in 2, the pubic bone in 2, and the gluteal region in 4. Invasion to the sacrum was observed in 7 patients. Twelve patients underwent surgical procedures consisting of intralesional resection in 6, marginal resection in 3, and wide margin resection in 3. Six of the 7 patients with sacral invasion developed local recurrence. Two patients with chondrosarcoma and one with parosteal osteosarcoma survived for 4 or more years, but the mean survival period in those with high grade malignant tumors was 11 months. These findings indicate the difficulties encountered in the treatment of malignant pelvic tumors.

In 1957, Pavlik introduced the Pavlik harness as a useful treatment for developmental dislocation of the hip (DDH), and subsequent studies have documented favorable outcomes among patients treated with this device. However, there are only a few articles reporting how early radiographic measurements can be used to determine the prognosis after treatment with the Pavlik harness. In this study, 217 hips from 192 patients whose DDH treatment with the Pavlik harness was initiated before they were 6 months old and whose follow-up lasted at least 14 years (rate, 63.8%) were analyzed using measurements from radiographs taken immediately before and after harness treatment, and at 1, 2, and 3 years of age. Severin's classification at the final follow-up was I or II in 71.9% and III or IV in 28.1% of the hips, respectively. Avascular necrosis of the femoral head (AVN) was seen in 10% of the hips. Stepwise multiple regression analysis was performed to retrospectively determine whether any radiographic factors were related to the final classification as Severin I/II or III/IV. Receiver opera-ting characteristic (ROC) curves were drawn for these factors, and a Wiberg OE angle (Point O was the middle point of the proximal metaphyseal border of the femur) of 2 degrees on the 3-year radiographs was found to be the most useful screening value for judging the acetabular development of DDH cases after treatment with a Pavlik harness, with a sensitivity of 71% a specificity of 93%, and a likelihood ratio of 10.1.

Surgical treatment of metastatic spinal cord compression is controversial. The purpose of this study was to investigate the effectiveness of our current surgical treatments and the use of spinal instrumentation. In this retrospective study covering the years between 1990 and 2006, 100 patients with spinal metastases which were secondary to various cancers underwent posterior and/or anterior decompression with spinal stabilization for the purposes of reduction of pain, and/or to help correct or improve neurological deficits. The group was made up of 60 men and 40 women whose ages ranged from 16 to 83 years (average of 60 years), and the average follow-up period was 14 months. The effect of treatment upon pain relief and neural deficits was assessed, and the cumulative survival rate was calculated by the Kaplan-Meier method. The average surgical time was 185min. This was calculated based on the following times, listed here with the surgery type:178min for posterior surgery;245min for anterior surgery;465 min for combined surgery;and 475min for total en bloc spondylectomy. Average blood loss during surgery was 1,630 ml for posterior surgery, 1,760 ml for anterior surgery, 1,930 ml for combined surgery, and 3,640 ml for total en bloc spondylectomy. Preoperative pain and paralysis were improved by 88% and 53%, respectively. In regards to surgical complications, postoperative epidural hematoma was observed in 2 patients, and instrumentation-related infection was observed in 1. Only 2 patients died within 2 months of surgery. In conclusion, posterior and/or anterior decompression with spinal stabilization is a safe and effective treatment for patients with spinal metastases, and can improve their quality of life.

Scoliosis is a common clinical manifestation of Rett syndrome, a neurodevelopmental disorder that almost exclusively affects females. The spinal curve in patients with Rett syndrome is typically a long C curve of a neuromuscular type. As the onset of the scoliosis is very early and shows rapid progression, early surgical intervention has been recommended to prevent a life-threatening collapsing spine syndrome. However, there are high perioperative risks in Rett syndrome patients who undergo spinal surgery, such as neurological compromise and respiratory dysfunction due to rigid spinal curve. We herein report the surgical result of treating severe rapid progressive thoracic scoliosis in a 16-year-old girl with Rett syndrome. Posterior segmental pedicle screw fixation was performed from T1 to L3 using a computer-assisted technique. Post-operative radiography demonstrated a good correction of the curve in both the sagittal and coronal alignment. There were no postoperative complications such as neurological compromise. The patient had maintained satisfactory spinal balance as of the 3-year follow-up examination.

This retrospective study assessed the radiographic results of 16 patients with avascular necrosis following treatment for developmental dislocation of the hip (DDH) who were subsequently treated between 1991 and 2005 by rotation acetabular osteotomy (RAO) combined with femoral intertrochan-teric osteotomy (FIO). Initial treatment was by Pavlik harness, cast fixation, or overhead traction. The parameters that showed consistent improvement were the index of centralization, the index of acetabular coverage, adequate reduction of the greater trochanter, and abductor sufficiency. The combined procedure appears to be effective in cases in which preoperative planning shows a reasonable expectation of congruency and osteoarthritis is limited to the early stages.

We report second malignant neoplasms which developed between 7 and 19 years after treatment in 3 pediatric patients with osteosarcoma. Two patients had been treated with only surgery, and another patient had been treated with a combination of surgery with chemotherapy and radiation therapy for primary lesions. Pediatric patients with osteosarcoma, in particular, require careful long-term follow-up to monitor not only metastases but also development of second malignant neoplasms.

There are few reports on skeletal reconstruction using the bone transport technique to repair bone defects caused by resections of tumors associated with osteosarcoma. We attempted to reconstruct a 23 cm bone defect after resection of an osteosarcoma of the left femur, and succeeded in gaining 17 cm by bone transport. Five years after surgery, this patient remains alive without metastasis or local recurrence.

There are few reports on skeletal reconstruction using the bone transport technique to repair bone defects caused by resections of tumors associated with osteosarcoma. We attempted to reconstruct a 23 cm bone defect after resection of an osteosarcoma of the left femur, and succeeded in gaining 17 cm by bone transport. Five years after surgery, this patient remains alive without metastasis or local recurrence.

Instability of the knee after the medial collateral ligament (MCL) injury is usually assessed with the manual valgus stress test, even though, in recent years, it has become possible to apply magnetic resonance imaging (MRI) to the assessment of the damage of the ligament. The valgus instability of 24 patients (12 isolated injuries and 12 multiple ligament injuries) who suffered MCL injury between 1993 and 1998 was evaluated with the Hughston and Eilers classification, which involves radiographic assessment under manual valgus stress to the injured knees. We developed a novel system for classifying the degree of injury to the MCL by calculating the percentage of injured area based on MRI and investigated the relationship between this novel MRI classification and the magnitude of valgus instability by the Hughston and Eilers classification. There was a significant correlation between the 2 classifications (p=0.0006). On the other hand, the results using other MRI based classification systems, such as the Mink and Deutsch classificaiton and the Petermann classification, were not correlated with the findings by the Hughston and Eilers classification in these cases (p0.05). Since MRI is capable of assessing the injured ligament in clinical practice, this novel classification system would be useful for evaluating the stability of the knee and choosing an appropriate treatment following MCL injury.

A minimally invasive plate osteosynthesis technique using a locking compression plate (LCP) has been used widely in trauma cases. Its advantages are that the MIPO technique does not interfere with the fracture site and thus provides improved biological healing, and that the LCP has excellent angular stability. Its use in bone lengthening, however, has not been established. In such cases, it is desirable to shorten the external skeletal fixation period as much as possible. Here, the MIPO technique using an LCP was applied to femoral distraction osteogenesis in an attempt to shorten the external skeletal fixation period. For femoral lengthening, the MIPO technique was performed in 2 stages. Orthofix external fixators (Orthofix, England) were used to insert screws from the anterolateral side rather than from the lateral side of the femur for bone lengthening. When sufficient callus formation was detected postoperatively at the site of bone lengthening, and the absence of infection was ensured, limb draping was performed, including a whole external fixator, and then the MIPO technique was applied with an LCP. In 3 cases (5 limbs), the average duration of external skeletal fixation was 134days, the average external-fixation index was 24days/cm, and the average consolidation index was 22days/cm. The MIPO technique using an LCP made it possible to shorten the external skeletal fixation-wearing period in femoral lengthening.

Mechanical stress plays a key role in the pathogenesis of cartilage destruction seen in osteoarthritis (OA). We investigated the effect of cyclic tensile stress (CTS) on the anabolic and catabolic gene expression of rat cultured normal chondrocytes using the Flexercell strain unit. The effects of interleukin (IL)-4, a chondroprotective cytokine, on the changes in gene expression induced by CTS were also investigated. CTS (7% elongation at 0.5 Hz) for 24 h did not affect the expression of aggrecan and type II collagen, whereas CTS significantly upregulated matrix metalloproteinase (MMP)-13 and cathepsin B mRNA expression by chondrocytes. IL-1beta expression was also signifi cantly upregulated by CTS up to 12 h. The upregulation of MMP-13 was observed at 3 h, which was earlier than that of IL-1beta. Furthermore, pre-treatment with IL-4 (10 ng/ml) suppressed both MMP-13 and cathepsin B induction by mechanical stress, as well as CTS-induced IL-1beta expression. Our results suggest that IL-4 might have a therapeutic value in the treatment of OA by downregulation of mechanical stress-induced MMP-13 and cathepsin B expression by chondrocytes.

In this study, we reviewed the clinical features of 11 patients with malignant schwannoma who were treated in our institute. Five patients had coexistent von Recklinghausen's disease and one of them showed multifocal occurrence. Patients with the centrally located tumors had a poorer prognosis than those with the others. The overall 3-year survival rate was 36%; 40% in patients with von Recklinghausen's disease and 33% in the others. At the time of the last follow-up, 9 patients had died of the tumor, one continued to be tumor free, and one was alive with tumor. Postoperative local recurrence developed in 5 patients (45%); 4 out of 6 patients (67%) who underwent a marginal excision and one out of 3 (33%) who underwent primary amputation. There was no local recurrence in patients after a wide excision with at least 3cm of normal tissue removed surrounding the tumor in all directions. Nine patients (82%) developed pulmonary metastasis. The effect of adjuvant chemotherapy was not clear in this study. The high risk of pulmonary metastasis in this disease indicates the necessity of more effective adjuvant chemotherapy.

We report the results of phase I/II studies of preoperative multidisciplinary treatment of 14 patients with soft tissue sarcoma using hyperthermia from November 1990 to April 1995. The preoperative treatment was conducted with thermo-radio-chemotherapy in 11 cases of stage III, and with thermo-radiotherapy as well as thermo-chemotherapy in three cases of stages I and II. Hyperthermia was carried out twice a week with totals ranging from 4 to 14 times (average: 8.4 times); each session lasted 60min. Radiotherapy was administered four or five times per week, and the dose was 1.8 2Gy/fraction, with a total of 30-40Gy in a four week period. Chemotherapy was mainly in the form of MAID regimen (2-mercaptoethanesulphonic acid (mesna), adriamycin, ifosfamide and dacarbazine). The tumors were surgically resected in all patients after completing the preoperative treatment. The efficacy rate, as expressed by the percentage of either tumors in which reduction rate was 50% or more, or tumors for which post-treatment contrast enhanced CT image revealed low density volumes occupying 50% or more of the total mass, was 71 % (ten of the 14 tumors). The mean tumor necrosis rate in the resected specimens was 78%. The tumor necrosis rate was significantly high (P < 0.05) in patients whose Time ≥ 42°C was of long duration. Postoperative complications were observed in six patients; among these, two patients developed wound infection that required surgical treatment as a complication of surgery performed in the early stage following the preoperative treatment. After a mean postoperative follow-up of 27 months, distant metastasis occurred in four patients resulting in three fatalities. The three-year cumulative survival rate was 64.3%. No local recurrence was observed in any patient during the follow-up, thus confirming our hypothesis that preoperative multidisciplinary treatment has an excellent local efficacy. We think that it would be valuable to conduct, at many facilities, phase III studies on the treatment of soft tissue sarcoma by a combination of surgery and preoperative multidisciplinary treatment using hyperthermia, paying close attention to the interval between these two modalities.

The purpose of this study was to investigate the surgical outcomes and to determine indicators of the necessity of surgical intervention. Twelve consecutive patients harboring symptomatic sacral perineural cysts were treated between 1995 and 2003. All patients were assessed for neurological deficits and pain by neurological examination. Magnetic resonance of imaging, computerized tomography, and myelography were performed to detect signs of delayed filling of the cysts. We performed a release of the valve and imbrication of the sacral cysts with laminectomies in 8 cases or recapping laminectomies in 4 cases. After surgery, symptoms improved in 10 (83%) of 12 patients, with an average follow-up of 27 months. Ten patients had sacral perineural cysts with signs of positive filling defect. Two (17%) of 12 patients experienced no significant improvement. In one of these patients, the filling defect was negative. In conclusion, a positive filling defect may become an indicator of good treatment outcomes.