Denied Am I reaching? Should I hire my own specialist and file supplementary claim?

While active duty in 2002 I broke my right foot. Long story short, it didn't heal correctly and they documented permanent physical alterations and altered gait while I was still in. Since getting out, I've been diagnosed with low back issues: L5-S1 spondylolisthesis and pars defects.

It's my contention that 20+ years of offloading weight onto my left side and limping due to right foot pain, that the foot injury has contributed to aggravation and worsening of the spine issues. The affected painful area is on my low left back and hip, where I offload my weight.

I filed claiming for lumbar/lower back issues aggravated or worsened by the foot injury.

While the claim was denied, they did concede that I have a diagnosed back disability

• degenerative arthritis
• degenerative disc disease
• spondylolisthesis

They also concede that: "the right foot fracture is service connected**."**

I'm lacking a medical nexus connecting the foot to the back.

The denial says "there is no evidence linking the conditions"

To me, the logical medical pathway looks like this: foot injury → altered gait → spinal degeneration (aggravation or worsening due to offloading to left side/spine/hip)

I had an X-ray recently that indicated: Bilateral pars interarticularis defects at L5 with grade 2 spondylolisthesis of L5 on S1. Multilevel degenerative disc disease and spondylosis, greatest at the L5-S1 level. 

I'm also pending physical therapy where I expect to discuss the biomechanics of it all further.

Am I off base thinking I have a secondary claim here?