Purposes:

See if permanent damage of the growth plate after physeal distraction is the rule and

Introduction: Surgeons have always been concerned about the fate of the growth plate after physeal distraction and for that reason this technique has usually been considered only in patients nearing maturity. Previous experimental work has shown that the velocity of distraction has an influence on the viability of the growth plate at follow-up (recommended rate: 0.5 mm/day). Clinically, it has also been our observation that the condition of the physis prior to distraction is another important factor related to physeal function in the long term.

Patients and methods: Since 1987 we have used low velocity physeal distraction in 43 bone segments of which 37 cases have been followed-up at least for 24 months and this has been the group included in this study. The indications were lengthening (14), angular deformity correction (19) and resection of benign bone tumours (4). Most patients (24) were older than 10 y.o. and 22 of them were followed-up until maturity. We have retrospectively reviewed these patients looking at the radiological morphology and function of the distracted growth plate at follow-up.

Results: Out of the 24 children older than 10 y.o., twenty showed a premature complete physeal closure.

We looked with interest at the 13 cases younger than 10 y.o. since the repercussions of iatrogenic physeal damage would obviously be bigger in this age group. Five out of the 13 showed premature closure and in the remnant eight an open growth plate was observed at follow-up. All patients with open and/or functioning physes after distraction had no local injuries in the growth plate prior to distraction (4 congenital short femora and 4 normal physes). On the contrary, four out of the five cases with prematurely closed physes, had a local physeal damage prior to distraction (3 bony bridges and one non-union), and the remnant was a congenitally short femur. Growth after distraction was difficult to assess in the congenitally short femora but it has been very satisfactory in the 4 cases of previously normal physes (2 benign tumours and 2 femoral shortenings due to hip disorders). In three cases of congenital short femur in pre-teenagers we were able to repeat distraction twice through the same physis, since it had remained open after the first distraction.

Conclusions: Physeal premature closure often follows physeal distraction, but not always. The condition of the physis prior to lengthening is an important factor with influence on its viability after distraction.

Purpose: To assess the usefulness of Bone Transport and other “compression-distraction” systems for the treatment of Segmental Bone Defects (SBD) in patients younger than 16 years-old.

Patients and methods: This series includes 18 patients (12 boys, 6 girls) with SBD of the following etiologies: Post-traumatic defects with/without sepsis (14 cases) and post-resection defects (3 Congenital Pseudoartrosis of the Tibia -CPT- and 1 Aneurismal Bone Cyst). The age of the patients ranged from 8 to 16 years and the length of the defect from 5 cm to 13 cm except for one case (23 cm). The defect was located in the tibia in 14 cases and in the femur in four.

Nine patients (the longest defects) were treated by conventional Bone Transport whereas other compression-distraction techniques were used in the remaining. Monolateral frames were used in all cases. All but one of the post-traumatic cases had additional injuries and in four occasions one of the joints adjacent to the defect was involved.

Results: All cases healed, 6 with only one operation and 12 with more than one procedure. Healing time depended upon the length of the defect, age of the patient, etiology and occurrence of complications. Healing index also varied mainly depending on the etiology (CPT cases were slower) ranging form 1.5 to 0.7 months/cm. Bone graft at the compression site was used in 9 cases. Radiologically the most striking feature was the very early tubulization of the reconstructed segment along with the quick healing of the SBD.

The most frequent complication was pin tract infection (37%), one case needing change of pins. Fracture at the pin site was seen in two cases.

Functional results were closely related to: a. The healing of the defect and b. The existence of injuries to the joints adjacent to the defect.

With a minimum follow-up of 18 months there were 2 poor functional results due to an avascular necrosis of the dome of the talus (talus neck fracture).

Conclusion: These techniques are very useful in selected cases of large SBD in young patients. They have shown low morbidity, quick healing and, above all, very good remodeling potential. Associated injuries play a very important role in the final outcome of the treatment.