Comparative Study of the Pain, Function, and Biomarkers of Joint Disease in the Transition to Adulthood in Individuals With and Without Cerebral Palsy.

The sample was small: 20 participants with cerebral palsy and 20 controls, and the authors say this limits power and generalizability. The cerebral palsy group lacked racial diversity and was mostly spastic-type cerebral palsy, so results may not apply to all people with cerebral palsy. Comparisons by GMFCS level were uneven, with 5 participants at GMFCS III and 15 at GMFCS I or II. Body mass index, individual muscle spasticity, and gait or range of motion data were not recorded, although these could affect pain, function, and biomarker levels. The blood and urine biomarkers could not be definitively assigned to the hip or knee joints studied. Controls were excluded if they had current knee or hip pain, but participants with cerebral palsy were not, which may bias pain comparisons toward higher scores in the cerebral palsy group. One participant from each group opted out of blood draw and one from each group could not provide urine. Non-ambulatory individuals with GMFCS IV or V were not included, so it says nothing about non-ambulatory cerebral palsy.

Grant funding supported the study and had no involvement in designing or running it. The paper does not state other author conflicts.

Do not read serum MMP-1 or urinary CTX-II as proof of hip or knee joint disease in cerebral palsy. This was a small pilot, COMP and MMP-3 did not differ between groups, and the paper says the blood and urine markers could not be definitively assigned to the hip or knee joints studied.