The October 2015 Oncology Roundup. 360 . looks at: Radiotherapy for the radioresistant; Multiple hereditary exostosis; The total femur as a limb salvage option; Survival prediction in osteosarcoma; What happens when chondrosarcoma recurs?; Thumbs up for vascularised fibular graft; Radiotherapy and survival; Musculoskeletal tumours in pregnancy

Introduction. Deformations of forearm with different degree of expression and functional restrictions of upper limb in children with hereditary multiple exostosis are formed in almost 80% of the cases. The question of indications for the selection and conduct of surgical procedure remains controversial, existing treatment methods and post-operative recovery methods for children need to be improved. Materials and Methods. The long-term outcomes of surgical treatment of 112 patients diagnosed with “Hereditary Multiple Exostosis” (HME) aged from 2 till 17 years old were researched. Evaluation of surgical treatment results was carried out in accordance with complaints, functional condition of the forearm, radiographs (taking into account reference lines and angles). Depending on the variant of deformation, the following surgical operations were performed: resection of bone-cartilage exostoses (in 20.5%); correction of forearm deformation with external fixator (in 79.5). In 14 cases, for a more accurate correction of deformity a hexapod frame was used. Results. Differentiated approach provided “good” anatomical and functional results in 55.6%; “satisfactory” results in 40.2%; “unsatisfactory” results in 4.2%. Postoperative complications in the form of non-union, pseudoarthrosis, delayed consolidation or neurological disorders were in 6.2%. Conclusions. The choice of surgical treatment is determined by the variant and severity of deformation. This approach allows to improve cosmetic and functional condition of forearm and adjacent joints. The use of hexapod allows to increase accuracy of correction of physiological axis of forearm bones

Osteochondromas occur are most commonly in the distal femur, proximal tibia and fibula and the proximal humerus. There are no large studies focusing on the clinical presentation, management and outcome of treatment for patients with an osteochondroma involving the proximal fibula. The purpose of this study is to specifically understand the manifestation of the proximal fibular osteochondroma on the preoperative peroneal nerve function, and how surgical management of the osteochondroma affects function immediately postoperatively and at long-term followup. This is an IRB-approved retrospective review of a consecutive series of patients with a proximal fibular osteochondroma (PFO) treated operatively at a single institution from 1990 to 2013. The medical record was carefully reviewed to identify demographic data, clinical data and especially the status of the peroneal function at various time points. There were 25 patients with 31 affected extremities who underwent surgical excision of the PFO at an average age of 12.4 years (range 3.0–17.9 years). There were 16 males and 9 females. The underlying diagnosis was isolated PFO in 2(8%) patients and multiple hereditary exostosis (MHE) in 23(92%) patients. Preoperatively, 9 (29%) had a foot drop and 22 (71%) did not. Those with preoperative foot drop underwent surgery at a younger age (9.1 vs 13.8 years) (p<0.004). Five of the nine (55.5%) had complete resolution, three (33.3%) had improvement, and one (11.1%) persisted postoperatively and required AFO. Of the 22 who were normal preoperatively, 5 (22.7%) developed a postoperative foot drop-three (60%) completely resolved, 1 (20%) improved, and 1 (20%) persisted and was found to have a transected nerve at exploration. In total, 23 of the 25 (92%) patients who had a PFO excision, had a normal or near-normal peroneal nerve function including those who had poor function preoperatively. A proximal fibular osteochondroma can result in a high incidence of peroneal nerve dysfunction prior to any treatment, but responds the majority of the time to surgical intervention with removal of the osteochondroma. For those who have normal preoperative function, 1 in 4 will develop a postoperative foot drop but nearly all improve spontaneously unless iatrogenic injured

Introduction: Total knee arthroplasty (TKA) in patients with skeletal dysplasia is challenging due to the anatomic variances and deformities. The purpose of this review is to understand the technical issues involved in treating these patients. Methods: Clinical notes, operative reports, and radiographs were retrospectively reviewed of 12 knees in 8 patients: 3 achondroplasia patients (one with bilateral 10° varus deformities, one with a 30° varus deformity in one knee and 25° varus deformity in the other knee, one with a 14° varus deformity); 3 multiple hereditary exostosis patients (one with bilateral 45° valgus deformities, one with a 45° valgus deformity in one knee and 15° valgus deformity in the other, one with a 11° valgus deformity); and 2 osteogenesis imperfecta patients (one with a 25° varus deformity, one with a 17° valgus deformity). Results: Surgical exposure required preoperative placement of soft-tissue expanders to avoid wound complications (1 knee), quadriceps snip (2 knees), and hardware removal (1 knee). Intraoperative balancing of the knee was more complex requiring a lateral epicondylar osteotomy (3 knees), medial release (6 knees), lateral retinacular release (6 knees), and proximal realignment to improve patellar tracking (1 knee). 5 knees required a constrained insert, 2 required tibial augments, one required use of cement and screw technique, and one required modification of an all-polyethylene tibia to accommodate the deformed tibial anatomy. 2 knees required custom tibial components. Complications included 2 peroneal nerve palsies which resolved 3 months postoperatively. Range of motion preoperatively averaged 103° (range 45 to 130°) and 100° postoperatively (range 85 to 120°). All patients were pain-free at their last followup (average follow-up 3.9 years). Conclusion: Special considerations must be made regarding surgical exposure, ligament balancing, implant selection, and anticipation of complications due to the unusual deformities when performing TKA in skeletal dysplasia patients

Aim: The pelvis is a rare location for osteochondromas and differentiation from chondrosarcomas can be difficult. We aim to aid this differentiation using tends and demographics of treated cases. Methods and Results: Patients referred to a supra-regional bone tumour centre with pelvic tumours, consequently diagnosed as osteochondromas were studied to determine the clinico-pathological features that differentiate them from chondrosarcoma. Treatment outcome was also reviewed. 30 patients were studied with a mean follow-up of 32 months. The mean age at diagnosis was 34yrs (range 19–79). The male to female ratio was 1:1. The most common location was the ilium (19 patients), with the pubis and ischium accounting for a third of patients. Only 1 patient had an acetabular osteochondroma. Median duration of symptoms prior to referral was 6 months (1–79). Pain without a lump was the main presenting symptom (16 patients), followed by lump with pain (6), and lump alone (6). Two patients presented with obstructive labour requiring emergency procedures. The lesions were solitary in 24 and associated with hereditary multiple exostosis (HME) in 6 patients. 1 patient had a radiation induced lesion. The lesions showed increased uptake on bone scans and the cartilage cap was less than 10mm in all but 2 patients. Treatment was surgical excision in 21 patients and observation with serial radiographs in 9. Histological examination confirmed osteochondroma in all patients, however 1 patient with HME had areas of Grade I malignancy. Significant surgical complications occurred in 1 patient who developed pulmonary embolism. Conclusion: We conclude that symptoms from osteochondromas of the pelvis are similar to those with chondrosarcomas and increased uptake on bone scans is seen in both. However, a tumour with a cartilage cap larger than 10mm or arising from the acetabulum is unlikely to be an osteochondroma

Introduction: In hereditary multiple exostosis (HME) the synthesis of the polysaccharide heparan sulphate (HS) is disrupted. HS-proteoglycans are low affinity receptors involved in fibroblast growth factor signaling. Activation of FGF receptor 3 (FGFr3) on mature chondrocytes leads to growth attenuation rather than stimulation. We tested the hypothesis that in HME chondrocytes with absent or reduced HS-PG synthesis there is impaired response to the FGFr3 ligand and loss of control of chondrocyte proliferation. Materials and methods: Chondrocytes were harvested from normal growth plate (epiphyseodesis) or HME osteochondroma cartilage cap obtained as surgical discard and cultured to 70% confluence in growth media. Cells were re-plated for experimentation. Growth curves were obtained for cells over a period of 5 days. In addition proliferative responses of healthy and HME chondrocytes were determined after low serum synchronization followed by challenge with FGF 9 (10 and 100ng/ml) and incorporation of BrdU for 2hours every two hours over a twenty eight hour period. Using these techniques it is possible to describe in detail the time dependent entry of cells into S-phase of the cell cycle and compare cell lines and treatment. Results: Significant differences were observed in the growth characteristics over a five-day period (p< 0.05). Under baseline growing conditions the chondrocytes derived from osteochondroma had a more rapid doubling time when compared with the normal growth plate chondrocyte (2.6+/− 0.6 vs 4.9+/−1.0, p< 0.05). In response to incubation with FGF-9 cells from normal growth plate have a lower peak proportion of cells entering the s-phase than with media alone (7% vs 25%). This inhibition is not observed in chondrocytes from osteochondroma. Conclusions: It would appear that osteochondroma chondrocytes are resistant to the normal regulatory effect of FGF-9 on cell proliferation. The differential response to FGF may be responsible for the growth differences observed both in-vitro and in-vivo