Statistics

Selective screening is the most cost-effective DDH screening strategy (International Hip Dysplasia Institute 2009 JBJS) — imprecise — The 2009 JBJS study was a decision analysis of hip outcomes (not costs) that favoured physical examination for all with selective ultrasonography; a later systematic review found screening cost evidence inconclusive/heterogeneous — medium confidence — source

If 95% confidence intervals overlap by more than 25%, the difference is not statistically significant — misleading — Overlapping confidence intervals do not determine significance; formal testing (log-rank/Cox for survival data, or a CI for the difference) is required. The >25% overlap rule is not a standard statistical criterion — source

Neoadjuvant chemotherapy for osteosarcoma is MTX + vincristine + cisplatin (2 cycles pre-op) — erroneous regimen — Standard neoadjuvant regimen is MAP: high-dose methotrexate, doxorubicin (Adriamycin) and cisplatin; vincristine is not part of standard osteosarcoma regimens (slide 118 correctly lists methotrexate, adriamycin, cisplatin) — source

Denosumab for GCT is 120mg once/week x 3 then once/2 weeks then monthly — dosing schedule imprecise — Approved GCTB dosing is 120 mg SC every 4 weeks with additional 120 mg loading doses on days 8 and 15 of the first month (weekly for the first 3 doses, then every 4 weeks - not 2-weekly) — source

Multiple myeloma 5-year survival is 30%, 10-year survival 11%, median survival 3 years — outdated — With modern therapy, SEER data (2016-2022) report 5-year relative survival around 62-64%; the 30%/11% figures are historical and should not be quoted as current — source

Malignant transformation in fibrous dysplasia is 1%, rising to 5-10% in polyostotic disease — Overstated for polyostotic disease — Published series report ~0.4-1% overall and up to ~4% in McCune-Albright/familial cases; 5-10% is higher than most sources — medium confidence — source

Intermediate osteopetrosis is autosomal recessive and is called Albers-Schonberg disease — Misleading / internally contradictory — Albers-Schonberg disease is the autosomal dominant type II (mild) form, as the same slide later states; intermediate osteopetrosis can be AR or AD — source

Autosomal dominant osteopetrosis is treated with interferon gamma-1b (Key et al NEJM 1995) — Misleading - Key 1995 studied severe infantile (recessive) disease — IFN-gamma-1b is FDA approved for severe malignant osteopetrosis (autosomal recessive), often as a bridge to HSCT; evidence in ADO is insufficient and it was poorly tolerated — source