Local recurrence of giant cell tumor of bone after intralesional treatment with and without adjuvant therapy.

BACKGROUND: The use of adjuvants after curettage has been well established for the treatment of giant cell tumor of bone. The purpose of this study was to analyze the rates of recurrence following different types of treatment as well as the influence of various factors of tumor presentation on those rates. METHODS: The data regarding benign giant cell tumors of the appendicular skeleton from ten bone tumor centers were evaluated. Axial and malignant tumors were excluded. The recurrence rates associated with the different treatment modalities were analyzed, and hazard ratios for a recurrence were calculated for multiple factors of tumor presentation. RESULTS: The study included 384 surgical procedures, involving 256 primary and 128 recurrent tumors. The mean duration of follow-up was 64.2 months. Wide excision was performed in seventy-eight cases (20.3%), and an intralesional procedure was done in 306 (79.7%). Of the intralesional procedures, 103 (33.7%) were performed without the use of adjuvants, 102 (33.3%) included filling with polymethylmethacrylate, seventy-four (24.2%) included polymethylmethacrylate filling after phenolization, and twenty-seven (8.8%) included use of local toxins. The overall recurrence rate after the intralesional procedures was 49% when no adjuvants had been used, 22% when polymethylmethacrylate only had been used as an adjuvant, 27% when polymethylmethacrylate had been used after phenolization, and 15% when phenol or other local toxins had been used (without polymethylmethacrylate). The highest rate of recurrence (36%) after curettage with adjuvants was associated with extracompartmental tumors. Recurrent tumors were not at increased risk for another recurrence, even when they were extracompartmental. The recurrence rate following curettage of a primary tumor without the use of adjuvants (55%) was higher than that following the same treatment of a recurrent tumor (39%) (p = 0.033). CONCLUSIONS: Use of polymethylmethacrylate as an adjuvant significantly reduces the recurrence rate following intralesional treatment of benign giant cell tumors, and it appears to be the therapy of choice for primary as well as recurrent giant cell tumors of bone. The significantly better results following treatment of recurrent tumors without adjuvants compared with the results of the same treatment of primary tumors were probably related to increased surgical thoroughness brought about by the surgeon's awareness of dealing with a riskier tumor.

The influence of callus distraction on the growth plate.

OBJECTIVES: This study was designed to investigate the morphology, thickness and cellularity of the growth plate during callus distraction performed in the immediate vicinity of the growth plate. METHODS: Lengthening of the right tibia by 25% was carried out on 24 beagle dogs by callus distraction. Distraction was started at the fifth postoperative day with a distraction rate of 0.5 mm twice a day. A control group of six dogs underwent tibial osteotomy and external fixation without distraction. Half of the dogs of both groups were sacrificed at the end of the distraction phase of 25 days (Group A) and the remaining 15 dogs after an additional consolidation period of 25 days (Group B). The tibia and femur was removed from the distracted right leg and from the left control side of each animal and longitudinal sections were cut and stained with Pentachrome. The thickness and cellularity of the regeneration zone, the proliferation zone and the hypertrophic zone were determined for the proximal tibial and the distal femoral epiphysis. RESULTS: During the distraction phase the thickness of the proximal tibial growth plate and its cellularity were reduced on the distraction side. During the consolidation phase there was a slight recovery in the proximal tibial growth plate. CONCLUSIONS: Callus distraction leads to a temporary reduction in growth of the affected physis.

Histomorphometry of distraction osteogenesis during experimental tibial lengthening.

OBJECTIVES: The aim of the current study was to analyze distraction osteogenesis histomorphometrically to investigate the amount of enchondral ossification adjacent to intramembranous ossification. STUDY DESIGN: Species-specific, longitudinal time study. METHODS Lengthening of 25% of the right tibia was performed in 24 beagle dogs by callus distraction after osteotomy and application of a ring fixator. Distraction was started at the fifth postoperative day with a distraction rate of 0.5 mm twice a day. Twelve dogs were killed at the end of the distraction phase of 25 days (group A) and the remaining 12 dogs after an additional consolidation period of 25 days (group B). The tibia was removed from the distracted right leg and from the left control side of each animal, and longitudinal sections were cut and stained with Pentachrome. In all tibiae, an area of 0.5 x 2.4 cm within the endosteal bone was evaluated histomorphometrically with a Merz grid, and the results were compared between distraction and control side as well as between the dogs of group A and group B. RESULTS: On the distraction side, the typical signs of an increased de novo bone formation with a significant increase of osteoblasts and osteoid in group A, as well as an additional significant increase of bone volume and trabecular thickness in group B, were found. In all distraction cases, islands of cartilage formation, which underwent enchondral ossification, were found, besides membranous ossification. The ratio between membranous and enchondral ossification was found to be five to one. CONCLUSION: Bone formation during distraction osteogenesis results from both membranous and enchondral ossification.

Circumferential fusion of the lumbar and lumbosacral spine using a carbon fiber ALIF cage implant versus autogenous bone graft: a comparative study.

This study reports on 92 patients treated with circumferential lumbar fusions for degenerative conditions. The elected procedure was a circumferential fusion using transpedicular stabilization. Two groups were examined depending on whether they were stabilized anteriorly with autogenous bicortical iliac crest graft (n = 38) or with an ALIF carbon fiber cage implant (n = 54). The patients were evaluated for clinical and radiographic outcome. The minimum follow-up interval was at least 12 months. Fusion rates, postoperative loss of correction, and clinical results, including pain at the bone donor site, neurologic function, satisfaction, depression, and consumption of analgesics, were not significantly different between patients with autogenous bone graft and patients with carbon cage. This study failed to prove major advantages of the carbon cages in the clinical and radiologic outcome.