Some people have claimed to have grown taller in a non-epiphyseal plate driven method via HGH.  Now it’s important to note that acromegaly is not solely based on HGH and there are some cases in gigantism where HGH levels are lower than people who supplement via HGH so it’s possible there’s another factor driving the length.  This topic was discussed before here.  In that page there are additional acromegalic x-rays and additional discussion of non-growth plate driven height growth.

You don’t just grow interstitially, you also grow appositionally even on the longitudinal ends of the bones.  For most, this is insignificant but for someone with high HGH and thereby higher bone turnover this could be much more significance but the question then becomes if they are gaining height in the feet and hands due to the larger number of bones there then in legs and arms then why aren’t the growing in the torso.

It follows logically that if two people are growing by different methods interstitial growth(traditional growth plate growth) and appostional growth on the longitudinal ends(endochondral ossification of the articular cartilage or some other bone thickening method) then the two bone shapes will look differently on the x-ray.

Here’s a “normal” hand x-ray:

Here’s an acromegalic hand x-ray:

One thing that strikes immediately is the greater whiteness between the acromegalic x-rays and the normal x-rays but the two bone shapes seem largely the same.  However there does seem to be greater articular cartilage spacing which could explain the increased hand size.

I couldn’t find a spine xray of someone with acromegaly but here’s a chest x-ray:

Unfortunately you can’t really tell anything about the spine because the bones are so thick.

Here’s a normal chest x-ray:

So basically the x-rays tell you that acromegaly may or may not cause a form of non-growth plate based longitudinal bone growth.  There’s just not enough x-rays of people with acromegaly to draw conclusions.  Or x-rays of people who supplement with HGH like Richard Piana.

Here’s a study(Unfortunately I couldn’t get the full study) that may have some insights:

Acromegaly and bone.

” Growth hormone (GH) and insulin-like growth factor-I (IGF-1) have pleiotropic effects on the skeleton throughout the lifespan by influencing bone formation and resorption. Despite these positive effects on skeletal metabolism, in presence of GH and IGF-1 excess, bone turnover increases excessively leading to deterioration of bone microarchitecture and high risk of fragility fractures, thereby impairing quality of life.

Coexistent hypogonadism, diabetes mellitus, hypovitaminosis D, hyperparathyroidism and over-replacement with glucocorticoids impair bone framework, however, the effects of acromegaly on bone mineral density (BMD) are still controversial and despite normalization of bone turnover after treatment, the risk for fractures remains increased. As a matter of fact, a major clinical aspect emerging from the studies published so far is the lack of clinical-diagnostic tools able to reliably predict the appearance of fractures in patients with acromegaly occurring even in the presence of normal or low-normal BMD.”

So bone turnover could potentially alter bone architecture and make non-growth plated based growth a possibility.