Physeal sparing technique reduces femoral growth disturbance in pediatric anterior cruciate ligament reconstruction patients.

PURPOSE: The purpose of this study was to compare the difference in limb length and angular deformity between two cohorts of patients who have underwent anterior cruciate ligament (ACL)-reconstruction using a femoral non-physeal sparing technique (N-PS) and a physeal sparing technique (PS). It was hypothesised that N-PS would result in less discrepancy in limb length and knee angles than PS.

METHODS

This is a comparative cohort study of 113 patients: 33 in N-PS who underwent ACL reconstruction between 2001 and 2010, and 80 in PS who underwent ACL reconstruction between 2013 and 2019. Radiographic evaluation, knee stability measurements and patient-reported outcomes (PROMS) were completed at the two-year minimum follow-up examination. Student's t-test, Wilcoxon signed-rank sum test and chi-squared test were used to analyse the data.

RESULTS

At time of surgery, the patients were 11.7 (standard deviation [SD]: 1.4) and 14.0 (SD: 1.3) years old in N-PS AND PS, respectively. N-PS showed a statistically significant difference in femoral length of 3.5 mm (95% confidence interval [CI]: 1.1-5.9) compared to the non-operated side, with no effect on femoral length in PS of 1.0 mm (95%CI: 0.0-1.9).Only a minor impact on tibial angulation (p = 0.07) was observed between the techniques. Sensitivity analysis showed that patients younger than 12.5 years at time of surgery were five times more likely to have a total length difference of more than 10 mm in N-PS than in PS (p = 0.05). Statistically significant differences (p = 0.02) were observed in knee laxity between the N-PS 1.5 mm (95%CI: 1.0-1.2) and PS 2.4 mm (95%CI: 1.9-2.8).

CONCLUSIONS

A femoral physeal sparing technique for paediatric ACL-reconstruction reduced femoral limb length growth disturbance compared with non-physeal sparing technique. Knee laxity was affected and PROMS were unaffected by the type of technique.

LEVEL OF EVIDENCE: Level III.