The GALNT3 gene encodes GalNAc-T3, which prevents degradation of the phosphaturic hormone, fibroblast growth factor 23 (FGF23). Biallelic mutations in either GALNT3 or FGF23 result in hyperphosphatemic familial tumoral calcinosis or its variant, hyperostosis-hyperphosphatemia syndrome. Tumoral calcinosis is characterized by the presence of ectopic calcifications around major joints, whereas hyperostosis-hyperphosphatemia syndrome is characterized by recurrent long bone lesions with hyperostosis. Here we investigated four patients with hyperphosphatemia and clinical manifestations including tumoral calcinosis and/or hyperostosis-hyperphosphatemia syndrome to determine underlying genetic cause and delineate phenotypic heterogeneity of these disorders. Mutational analysis of FGF23 and GALNT3 in these patients revealed novel homozygous mutations in GALNT3. Although the presence of massive calcifications, cortical hyperostosis, or dental anomalies was not shared by all patients, all had persistent hyperphosphatemia, as well as inappropriately normal 1,25-dihyroxyvitamin D [1,25(OH)2D]. Three of the patients also had confirmed low circulating intact FGF23 concentrations. The four novel GALNT3 mutations invariably resulted in hyperphosphatemia due to low intact FGF23, but other clinical manifestations were variable. Therefore, tumoral calcinosis and hyperostosis-hyperphosphatemia syndrome represent a continuous spectrum of the same disease caused by increased phosphate levels, rather than two distinct disorders.

Several controversies exist regarding the surgical difficulties and the results of total knee arthroplasty performed after failed valgus high tibial osteotomy (HTO), and the main subject is the change in patellar height that results as patella baja or infera. The purpose of this retrospective study was to evaluate patellar height after valgus HTO and the measurement methods that were actually used. Eighty-five knees that were subjected to valgus HTO were evaluated both preoperatively and postoperatively according to the Insall-Salvati Index (ISI), Blackburne-Peel Index (BPI), and Caton Index (CI) to assess any alteration of patellar tendon height that was present. All cases underwent closing wedge osteotomy with three staples or plate internal fixation and were allowed early range of motion. Significant decrease in mean patellar height ratios was detected according to all three indexes at 85 months of mean follow-up. The percentages of the decrease were 8.26% in ISI, 9.08% in BPI, and 6.34% in CI. Two knees showed patella infera according to ISI, one according to BPI and three according to CI. There were no significant correlations between the indexes and clinical status of the patients. Elevation of patella relative to the femur in closing wedge valgus HTO procedure due to the shortening of the segment between tibial tuberosity and joint line is normally expected. A significant decrease in patellar height according to ISI suggests that there should be patellar tendon shortening as patellar height cannot be changed. BPI and CI for determining patellar height in valgus HTO do not accurately measure the alteration of patella because they may affect the tibial inclination and antero-posterior translation of the proximal fragment. Another measuring system based on femoral reference points should be proposed to determine the exact change of patellar height in the valgus HTO procedure.

The calcaneal angles show considerable variations in diverse ethnic groups and populations in terms of normal range, age, gender, and side. The ranges herein reported (20-46 degrees for BA, 100-133 degrees for GA) can be used as reference values for the Turkish population.

Functional results are satisfactory in distal humerus fractures treated with stable osteosynthesis and parallel-plate technique that allow early active motion.

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