Radiosensitivity, repair capacity, and stem cell fraction in human soft tissue tumors: an in vitro study using multicellular spheroids and the colony assay.

Radiation doses necessary to control 50% of spheroids (SCD50) were determined for five human soft tissue tumor lines after single dose and fractionated irradiation. Spheroids with 1000-1500 cells were used throughout. A similar number of cells per spheroid resulted in different sized spheroids for the respective cell lines. The parameters alpha, beta, and the number of regenerating cellular units per spheroid (SRU) were estimated from the spheroid control data using a direct fit according to the linear quadratic model assuming Poisson statistics. The number of spheroid regenerating cellular units was also determined from the growth delay at doses required for 10% spheroid control. In addition, alpha, beta, and the fraction of clonogenic cells of the five cell lines were obtained from a soft agar colony forming assay. The most precise parameter for radiation sensitivity was the SCD50, with a coefficient of variation smaller than 5%. SCD50 values ranged from 5.9 to 11.0 Gy for the five soft tissue tumor lines. Two of the five cell lines showed significantly higher alpha values and lower calculated survival fractions after 2 Gy (SF2) in the soft agar clonogenic assay than in the spheroid control assay. This points to a resistance-enhancing effect in the spheroid system. Whereas the fractions of SRU from the number of cells per spheroid, estimated from the spheroid control and growth delay assays, agreed well, no significant correlation existed between the fraction of SRU and the fraction of clonogenic cells in the soft agar colony forming assay. The alpha/beta ratios as a descriptive measure of the fractionation sensitivity of the tumor cell spheroids in the spheroid control assay corresponded well with those derived from the dose-cell survival data using a soft agar colony forming assay. Two of the five cell lines showed high fractionation sensitivities with alpha/beta values smaller than 5 Gy while those of the remaining three ranged from 7.8 to 10.8 Gy. Spheroids are structurally more similar to in vivo tumors than monolayer cultures. From the observed lack of correlation in the radiosensitivity parameters alpha and SF2 as well as in the fraction of SRU or clonogenic cells obtained from the spheroid control assay or the colony forming assay, one would expect even greater differences between results from colony forming assays and the radiosensitivity of in vivo tumors, at least for human soft tissue sarcomas.

Pathological fractures of the proximal femur with impending shaft fractures treated by THR and cemented intramedullary nailing: a report of nine cases.

We have used total hip replacement combined with cemented intramedullary nailing to treat a selected group of nine patients with pathological fractures of the proximal femur and impending fractures of the shaft due to metastases. One patient died from cardiopulmonary failure on the third postoperative day, but the others were able to walk within the first week after operation. Complications included one recurrent dislocation of the THR and one fracture of an osteolytic lesion of the femoral shaft during nail insertion. Both were managed successfully. The hybrid osteosynthesis which we describe is an alternative to the use of tumour or long-stem prostheses; it has the advantage of preserving bone stock and muscle attachments.

Autologous bone transplant after sternal resection.

Two patients underwent subtotal sternal resection for tumors of the sternum. Anatomical and functional reconstruction was performed with bone fragments harvested from the internal lamina of both iliac wings. There were no infections and no instabilities. Late postoperative follow-up included CT-scan of the thorax and pulmonary function testing, which was not compromised. We conclude that this surgical approach is very efficient in regard to function and chest wall stability.

[Muscle abnormalities on the back of the hand and their differentiation from soft-tissue tumors]. / Muskelanomalien am Handrücken und deren Abgrenzung zu Weichteiltumoren.

Anomalous muscles at the hand and forearm are described in several studies. They may be confused with ganglia or with other soft-tissue tumours. Two rare cases of atavistic muscles in the area of the back of the hand are described which caused intense pain of the wrist during some months. During the operation an enlongated muscle directly below the extensor tendon, was found which was covered by the extensor retinaculum. It is an extensor digiti brevis manus, which exists in amphibia and is replaced in man by the long tendonous part of the extensor digitorum.

[Absorbable synthetic mesh in abdominal surgery. Indications, operative procedures and results]. / Resorbierbare Kunststoffnetze in der Abdominalchirurgie. Indikation, Operationsverfahren und Ergebnisse.

Compared to non absorbable mesh, the use of absorbable mesh offers a wider range of surgical indications. Otherwise the complications of implanted non absorbable mesh can be almost avoided. Reporting the experience of 41 own cases in abdominal surgery, indications, surgical technique and complications of absorbable mesh are demonstrated.

[Osteoid osteoma--a diagnostic and therapeutic problem?]. / Das Osteoidosteom--ein diagnostisches und therapeutisches Problem?

INTRODUCTION: The aim of the following article is to summarize our experience in the treatment of osteiod osteomas, with special emphasis on diagnostic and therapeutic pitfalls. PATIENTS AND METHODS: A consecutive series of 14 patients with osteoid osteomas was treated surgically between 1985 and 1996. All tumors but one were located in the lower limb. The main symptom was pain, being worse at night and being responsive to oral salicylates (10/14 patients). As reported in other studies, the duration of symptoms was unacceptably long (mean 24 months). The classical pathognomonic symptoms were misinterpreted in many cases, leading to frustrating conservative and even operative therapies. RESULTS: Open biopsy prior to surgical excision is not indicated because of the typical clinical and roentgenographic imaging of these lesions. Surgical excision of the nidus is the treatment of choice and gives immediate pain relief. If the characteristic morphology is not evident in plain roentgenograms, conventional tomograms, radionuclide scans and computerized tomography are reliable tools. All patients were free of disease at a mean of 6.6 years after operation. CONCLUSION: In symptomatic patients with osteoid osteomas the excision of the nidus is the established diagnostic/therapeutic modality. Minimally invasive procedures seem to be alternatives to classical surgery.

[Results of transgenicular amputation with dorsal skin-muscle flap-plasty in patients in the final stage of arterial occlusive disease]. / Ergebnisse der transgeniculären Amputation mit dorsaler Haut-Muskel-Lappenplastik bei Patienten im Endstadium der arteriellen Verschlusskrankheit.

A modified technique of knee joint disarticulation by using a dorsal musculocutaneous flap of the gastrocnemius muscle was first described in 1985. The retrospective operative results in 60 patients with gangrene due to peripheral vascular disease (mean age 69 +/- 12 [43-93] years, 29 female, 31 male) with 62 knee disarticulations are reported. After a mean survival period of 18 (1-53) months 47% (n = 28) of the patients had died due to cardiopulmonal reasons after a mean follow-up period of 26 (3-71) months. In-hospital 48 day-lethality was 10%. 9 patients (15%) were re-amputated at above-knee level and in 5 patients operative revisions of the soft tissue were performed. After discharge from hospital 29 of 54 patients (54%) were able to walk with the aid of a prosthesis. We conclude that knee disarticulation with the use of a myocutaneous gastrocnemius flap is a safe and functionally acceptable operative method in high-risk vascular patients.

[A comparative morphometric and histologic study of five bone substitute materials].

OBJECTIVE: To investigate and compare the osteogenesis of bone substitute materials. METHODS: 52 Chbb: ch rabbits were divided into 5 groups. Five different porous biomaterials, including natural bovine hydroxyapatite (Bio-OSS, BK V/1), semi-synthetic coral hydroxyapatite interpore 500, synthetic tricalcium phosphate CEROS 82 and glass POROLITH, were implanted together with free periosteum into the muscle of rabbits for up to 3 and 6 weeks. Undecalcified sections were prepared for microradiography, light and UV microscopy, and morphometry. RESULTS: Bone ingrowth was present in all such implantats. Bone formation was limited to the periphery of the Ceros blocks, that are lack of pore interconnection, while the other 4 materials with an interconnected porous system were infiltrated by bone into the centrum. Planimetric analyses showed that the specimens were composed of 6.5%-19.0% new bone at the 3rd week and 14.2%-25% at the 6th week respectively. The difference of bone ingrowth was only significant between Bio-OSS and BK V/1 at the 3rd week. No statistically significant difference of bone volume was found within the 6 week groups. There was a positive correlation between the new bone volume and the porosity of the materials. CONCLUSION: For the bone ingrowth, the structure of the materials, specifically the pore and pore interconnections, is more impatant than the chemical composition.

[Continuous skin expansion for covering soft tissue defects of the foot sole]. / Die kontinuierliche Hautdistraktion zur Deckung von Weichteildefekten der Fusssohle.

Reconstruction of the weight-bearing area of the sole of the foot is a major surgical problem, regardless of the aetiology of the soft-tissue defects. Numerous reconstruction methods have been described for coverage of plantar defects of the heel with local and free flaps. Skin expansion and skin traction have been described by several authors. According to the Ilizarov technique, a new method has been devised for the closure of posttraumatic soft-tissue defects in the weight-bearing area of the sole by skin stretching with Kirschner wires without the aid of either local or free flaps. The operative procedure is very simple: the sharp ends of Kirschner wires are bent with pliers into hook-shaped semicircles. These ends are then inserted into the skin of the sole at intervals of 3-4 mm, alternately close to and distant from the wound edge. The opposite ends of the K-wires are sandwiched between two small AO plates. These plates are pressed together with screws and nuts; additionally, the ends of the K-wires are bent around the plates to prevent loosening. A frame is set up around the heel and connected to the tibial external fixator. The two plates with the K-wires clamped between are mounted on the threaded rods of an Ilizarov external fixation system. Then the foot is temporarily fixed to the tibia in neutral position by a Schanz screw inserted into the first metatarsal. The soft-tissue defect is treated with moist compresses changed daily.(ABSTRACT TRUNCATED AT 250 WORDS)

Massive intercalary bone allografts in the treatment of primary and secondary bone tumors. A report on 21 cases.

From 1981 to 1993, 21 patients received intercalary bone allografts for reconstruction of the extremity after en bloc tumor resection (15 malignant and 6 benign tumors). The allografts were collected from multiorgan donors and cryopreserved at -70 degrees C. The mean follow-up was 4.4 (range 1-13) years. The fate of the grafts was followed by conventional radiography, bone scintigraphy, and functional assessment. The overall survival rate of the 7 patients with high-grade malignancies was 86%. Solid union of the graft-host sites in less that 15 months occurred in 85%. An increased isotope uptake of the graft indicates that incorporation at the osteotomies as well as remodelling is still continuing at 9 years after operation. The overall complication rate was 43%; 3 patients had two or more complications. Complications were related to the allograft in 6 (infection or fatigue fracture in 1 and delayed healing in 4 cases) and to the osteosynthesis in 3 patients. The definitive results after treatment of complications show that satisfactory results have been obtained in all but 2 patients: 62% had excellent, 19% good, and 10% fair results. Intercalary allografts therefore provide a valuable solution for large skeletal defects after resection of bone tumors.

[Massive allogeneic cortical transplants in therapy of primary and secondary bone tumors]. / Allogene kortikale Massivtransplantate in der Therapie primärer und sekundärer Knochentumore.

From 1981 to 1995, 22 patients received intercalary bone allografts for reconstruction of the extremity after en bloc tumor resection (16 malignant, six benign lesions). Solid union of the graft-host sites within 15 months occurred in 86%. The overall survival rate of patients with high-grade lesions was four of seven and with low-grade lesions eight of nine after 4.5 years. Despite the high complication rate of 42%, intercalary bone allografts provide a valuable solution for reconstruction of the extremity after tumor resection in long bones.