You may want to ask your doctor about consulting with an orthopedic surgeon. Perhaps one who specializes in children and adolescents would be best. The surgeon will repeat the history and physical exam already done by your family physician. A second look is never out of line.
If X-rays have already been taken, then more advanced imaging studies may be needed. For example, a bone scan or MRI may be helpful. Single photon emission computed tomography (SPECT) of the lumbar and sacral spines can look at nerve roots, discs, and bone. Defects in the bone, slippage of the bone, and changes in soft tissues can be seen with these tests.
Once the proper diagnosis is made, then ways to treat or manage the synmptoms can be suggested.