Congenital pseudarthrosis of the tibia (CPT) has traditionally been a difficult condition to treat, with high complication rates, including nonunion, refractures, malalignment, and leg length discrepancy. Surgical approaches to treatment of CPT include intramedullary rodding, external fixation, combined intramedullary rodding and external fixation, vascularized fibular graft, and most recently cross-union. The current study aims to compare the outcomes and complication rates of cross-union versus other surgical approaches as an index surgery for the management of CPT. Our hypothesis was that a good index surgery for CPT achieves union and minimizes complications such as refractures and limb length discrepancy. A multicentre study was conducted involving two institutions in Singapore and China. All patients with CPT who were surgically managed between January 2009 and December 2021 were included. The patients were divided based on their index surgery. Group 1 included patients who underwent excision of hamartoma, cross-union of the tibia and fibula, autogenic iliac bone grafting, and internal fixation for their index surgery. Group 2 included patients who underwent all other surgical procedures for their index surgery, including excision of hamartoma, intramedullary rodding, and/or external fixation, without cross-union of the tibia and fibula. Comparisons of the rates of union, refracture, limb length discrepancy, reoperations, and other complications were performed between the two groups.Aims
Methods
This study evaluated the effect of limb lengthening
on longitudinal growth in patients with achondroplasia. Growth of
the lower extremity was assessed retrospectively by serial radiographs
in 35 skeletally immature patients with achondroplasia who underwent
bilateral limb lengthening (Group 1), and in 12 skeletally immature
patients with achondroplasia who did not (Group 2). In Group 1,
23 patients underwent only tibial lengthening (Group 1a) and 12 patients
underwent tibial and femoral lengthening sequentially (Group 1b). The mean lengthening in the tibia was 9.2 cm (59.5%) in Group
1a, and 9.0 cm (58.2%) in the tibia and 10.2 cm (54.3%) in the femur
in Group 1b. The mean follow-up was 9.3 years (8.6 to 10.3). The
final mean total length of lower extremity in Group 1a was 526.6
mm (501.3 to 552.9) at the time of skeletal maturity and 610.1 mm
(577.6 to 638.6) in Group 1b, compared with 457.0 mm (411.7 to 502.3)
in Group 2. However, the mean actual length, representing the length
solely grown from the physis without the length of distraction,
showed that there was a significant disturbance of growth after
limb lengthening. In Group 1a, a mean decrease of 22.4 mm (21.3
to 23.1) (4.9%) was observed in the actual limb length when compared
with Group 2, and a greater mean decrease of 38.9 mm (37.2 to 40.8)
(8.5%) was observed in Group 1b when compared with Group 2 at skeletal
maturity. In Group 1, the mean actual limb length was 16.5 mm (15.8 to
17.2) (3.6%) shorter in Group 1b when compared with Group 1a at
the time of skeletal maturity. Premature physeal closure was seen
mostly in the proximal tibia and the distal femur with relative
preservation of proximal femur and distal tibia. We suggest that significant disturbance of growth can occur after
extensive limb lengthening in patients with achondroplasia, and
therefore, this should be included in pre-operative counselling
of these patients and their parents.
