Many people have noticed a large width gain in the epiphysis after performing LSJL. There are stem cells in the synovial joint and new osteophytes could be formed from there. Although this is a different mechanism than endochondral ossification, it does prove LSJL's ability to induce chondrogenic differentiation of a stem cell type(if it is in fact osteophyte formation). Since bone is more sturdy than the synovial capsule, more hydrostatic pressure should be needed to induce sufficient pressure to induce chondrogenic differentiation there. If you are not feeling interestitial fluid flow in your bone and your bone is not increasing in width than it may be safe to say that you are not providing enough pressure as both of those events should occur before sufficient pressure for endochondral ossification. However, it is unknown how much pressure after this point is needed to induce endochondral ossification. In a few days, I will be stopping LSJL on the finger of my left hand and begin performing it on my right hand. To make sure that that the increase in width is due to osteophyte formation and not some sort of callus.
Surprising evidence of pelvic growth (widening) after skeletal maturity.
"Following an increase in length and width during childhood and adolescence, skeletal growth is generally assumed to stop. This study investigates the influence of aging on the dimensions of the pelvis and the L4 lumbar vertebra during adulthood. The dimensions of the pelvis, L4 vertebra, and femoral heads were calculated for 246 patients who had received pelvic and abdominal Computed Tomography scans. Linear regression analysis determined the significance of relationships between age and width of the pelvis. There was a strong correlation between increasing patient age and increasing width of the pelvis at the trochanters, (0.333 mm/year of age p<0.0001), at the iliac wings, (0.371 mm/year of age p < 0.0002), and between the femoral heads, indicating that the bony pelvis widens over 20 mm between the ages of 20 and 80. The pelvic inlet did not enlarge over time while the distance between the hips and the femoral head diameter did significantly increase[the femoral head is an epiphyseal type bone which should not be able to increase in width without periosteal deposition]. The height of L4 did not increase over time, but the L4 width did increase. These correlations were seen in both genders. Surprisingly, our results suggest that the pelvis and L4 vertebra increase in width after skeletal maturity and cessation of longitudinal growth."
In the study it mentioned that L4 vertebral height did increase by 0.9mm. However, it was done between the ages of 20to80 and some say that vertebral height growth does not cease until the mid 20s. So this increase could have occurred before then. It is also possible of course that the growth occurred later as well. There was a positive slope for age indicating that there was an increase in vertebral height even into the 80s.
"the femoral head data, which we expected would also show no increase (because there is no known mechanism for enlargement of the femoral heads) did show enlargement of the femoral heads with age"<-indicating the possibility of something like osteophyte based bone formation.
"We also were unable to confirm our third hypothesis, that widening of the pelvis was simply due to periosteal appositional bone formation, because we observed no significant change in the pelvic inlet width whereas appositional formation would presumably result in a reduction in the width of the inlet. If periosteal apposition is due to the previously described bone enlargement in response to osteoporosis, one would expect that there would be more marked differences between the enlargement of male and female subjects as well as a significant change in the slope of the line (as represented by the triangular decade means) after age 45 in women, which we did not observe in this data. The significant increases in inter-femoral head distance also cannot be explained by simple periosteal apposition and would appear to require some conformational change in the pelvis."<-Bone formation by means other than periosteal deposition is very promising for longitudinal height growth as of course periosteum is not on the longitudinal ends of the bones. If this mechanism for width increase can be found than it probably can be used for height growth.
"Our first thought was that the enlargement was due to calcification of the deeper layers of the cartilage (apparent enlargement only). It may be, but 3.3 mm of enlargement of the diameter would represent 1.6 mm of calcification of the cartilage on each side of the head over the years from age 20 to 80 which seems to be a great deal of calcification as the total thickness of the cartilage is only 2–3 mm (joint space 4–5 mm)."<-now endochondral ossification could take a smaller part of cartilage and turn it into a larger total width due to chondrocyte hypertrophy.
This study provides strong evidence for non-periosteal bone growth either occurring through endochondral ossification within the synovium or within the bone.