Objectives:

Cerebral palsy (CP) is a neurological condition resulting from disruptions in early brain development, primarily affecting motor function and muscle control. In spastic CP, crouch gait can be addressed through hamstring lengthening surgery. While open hamstring lengthening (oHSL) is the standard procedure, percutaneous hamstring lengthening (pHSL) has emerged as a less invasive alternative. This systematic review and meta-analysis aimed to compare oHSL and pHSL with respect to outcomes, specifically popliteal angle reduction, in the treatment of crouch gait in children with spastic CP.

Methods:

This study followed PRISMA guidelines and was registered in PROSPERO (CRD420251152548). Searches of PubMed, Scopus, Web of Science, Embase, and Cochrane Library were conducted up to September 2025. Eligible studies directly compared oHSL and pHSL for crouch gait correction in spastic CP. Data extraction and risk of bias assessments were independently performed by two reviewers using ROB-2 and ROBINS-I. Random-effects meta-analysis, sensitivity analysis, meta-regression, and GRADE were conducted.

Results:

Five studies (two randomized controlled trials and three cohort studies) involving 176 spastic CP patients and 252 affected limbs were included. Both oHSL and pHSL significantly reduced the popliteal angle, but the pooled mean difference was not statistically significant (MD = −0.02; 95% CI, −3.64 to 3.61; p = 0.99; I² = 57.8%). Meta-regression showed that the female proportion contributed to heterogeneity. GRADE rated the evidence for popliteal angle improvement as moderate.

Conclusion:

Both oHSL and pHSL significantly improved the popliteal angle in children with spastic CP, with no statistically significant difference between procedures. Functional outcomes could only be assessed qualitatively because of the limited available evidence. Larger comparative studies evaluating functional outcomes are needed.