Extreme femoral valgus and patella dislocation following lateral plate fixation of a pediatric femur fracture

Genu Valgum After Distal Femur Extension Osteotomy in Children With Cerebral Palsy

BACKGROUND

Distal femur extension osteotomy (DFEO) is a common treatment for knee flexion contracture and crouch gait in patients with cerebral palsy (CP), but skeletally immature patients tend to develop genu valgum deformities after DFEO. This study aimed to report the tendency of valgus changes after DFEO and determine the risk factors for subsequent surgery for excessive genu valgum.

METHODS

This retrospective case-control study included 25 children with CP who underwent DFEO in 44 limbs for knee flexion contractures ≥15 degrees at a mean age of 11.0 years. Radiologic measurements included the anatomic lateral distal femoral angle (aLDFA), anatomic tibiofemoral angle (aTFA), medial proximal tibia angle, and plate-condyle angle, postoperatively and at the latest follow-up. Age, sex, preoperative knee flexion contracture angle, Gross Motor Function Classification System level, and radiographic measurements were compared between children with and without subsequent guided growth for genu valgum.

RESULTS

A significant valgus change was observed at the distal femur in the first postoperative year (aLDFA from 83.6 to 80.1 degrees, P<0.001; aTFA from 176.1 to 172.5 degrees, P<0.01; plate-condylar angle from 5.3 to 9.5 degrees, P<0.001). Valgus changes occurred in 36 of the 44 limbs (82%) by an average of -4.6 degrees in the aLDFA, and subsequent guided growth was performed in 5 patients (20%). Guided growth for genu valgum was associated with a greater postoperative valgus angle (aLDFA: 78.0 vs. 84.9 degrees, P<0.01) but not with age, Gross Motor Function Classification System level, or preoperative flexion contracture.

CONCLUSIONS

Distal metaphyseal osteotomies and distally placed angled plates near the physis are associated with valgus changes following growth. We recommend making a slight varus alignment during DFEO to compensate for subsequent valgus changes.

LEVEL OF EVIDENCE

Level III-therapeutic, retrospective comparative study.

Clinical, radiographic and pedobarographic analysis of skeletally immature patients with surgically treated distal metaphyseal fractures of the tibia: is concomitant fixation of the fibula necessary?

This study evaluated the outcomes of distal tibia metaphyseal fractures (DTMFs) managed surgically and compared the outcomes of patients with and without associated fibula fracture fixation. Thirty-two consecutive patients (14 males; mean age at the time of injury: 7.8 years) with closed displaced DTMFs, with (22 patients; group A) or without associated fibula fractures fixation (10 patients; group B), were included. Besides standard radiographic measurements, the following static and dynamic pedobarographic parameters were evaluated: foot total static plantar pressure percentage (PP%), static plantar pressure percentage of the forefoot (PP%) and of the rear foot (PP%), landing sequence of the metatarsals during contact with the ground (MT), and impulse percentage of the metatarsal heads (MT%) and the medial and lateral heel (MH% and LH%). All patients were followed for at least 2 years (range: 2-4.5 years). Functional outcomes were excellent to good in all but two patients (93.8%) at the last follow-up visit using the Johner-Wruths criteria'. Radiographic measurements, PP%, PP%, PP%, MT%, MH% and LH% were not significantly different between two groups as well as between injured and uninjured side of patients within the same group (P > 0.05). Abnormal MT sequence was found in 40.9% of group A (9/22) and in 40% of group B patients (4/10) (P > 0.05). Stabilization of associated fibula fractures did not significantly impact the clinical, radiographic and pedobarographic outcomes of the children with displaced DTMFs who were surgically treated. Level of evidence: Level III.