Background
Increased knee flexion during the stance phase of gait (flexed knee gait) is one of the most common gait abnormalities in spastic diplegia. Hamstring lengthening in ambulatory patients is widely considered to be the standard surgical procedure for the correction of increased knee flexion.
Aim
The aim of this work is to evaluate the results of fractional distal hamstring lengthening in correction of flexion knee gait in ambulatory children with spastic diplegic cerebral palsy.
Patients and methods
Between 2007 and 2011, twenty six patients with spastic diplegia with flexion knee gait were treated by fractional hamstring lengthening as a part of multi-level management. There were 17 (65.4%) boys and 9 (34.6%) girls in the series, all treated patients were diplegic with both lower limb affection. The mean age of the patients at the time of operation was 8.15 ± 1.826 (range 5 to 12) years, other procedures were needed in 11 patients to treat hip adduction and equinus deformities.
Results
At the end of a follow up period of 22.9 (12–36) months, a significant reduction in the mean popliteal angle was noted postoperatively as it was improved from a mean of 54.4 ± 4.87 (48–63) preoperatively to 27.2 ± 2.41 (22–30) after surgery. This relation was proved to be statistically significant  ≤ 0.001. Much improvement in the knee flexion on standing was recorded after surgery, as the knee flexion on standing improved from 28.5 ± 4.85 (20–35) preoperatively to 3.7 ± 3.01 (0–10) postoperatively, also this was proved to be statistically significant,  ≤ 0.001.
Conclusion
Distal hamstring lengthening is an effective procedure in treatment of cerebral palsy patients with flexion knee gait in a short period of follow up but longer follow up is needed to assess the maintenance of the results.