W. Kapp et al., Long-term residual musculoskeletal deficits after femoral shaft fractures treated with intramedullary nailing, J TRAUMA, 49(3), 2000, pp. 446-449
Background: Locked intramedullary (IM) nailing has been recognized as one o
f the most reliable methods for treatment of femoral shaft fractures, Altho
ugh IM nails are routinely used in the treatment of these fractures, the lo
ng-term effects of retained IM nails are unknown.
Methods: seventeen patients with radiographically documented healed fractur
e of femoral diaphysis after locked IM nailing technique were evaluated at
a follow-up of at least 18 months postoperatively, All patients had returne
d to their preinjury level of function and activity before the study, The b
one mineral densities (EMD) of the injured and contralateral femora were me
asured using dual energy x-ray absorptiometry (DEXA), BMD of symmetrical re
gions in the femoral neck and medial and lateral Femoral cortex of the impl
anted and contralateral femorawere compared. Postinjury muscle function was
assessed from measurement of the isometric strength of six separate muscle
groups (quadriceps, hamstrings, hip extensors, hip flexors, hip abductors,
and hip adductors) in treated and control extremities,
Results: The average BMD of the femoral neck region of instrumented femora
was 9% less than in contralateral control. Within the medial cortex, BMD of
the control femora was an average of 20% greater than in the implanted sid
e. In the lateral cortex, the difference averaged 13%, The isometric dynamo
metric data demonstrated a statistically significant reduction in the stren
gth of the quadriceps of the instrumented extremities as compared with the
contralateral ones, There was no significant difference in the strength of
the hamstrings, hip extensors, hip flexors, abductors, or adductors, In the
control extremities, the average torque generated by isometric contraction
of the quadriceps was 3.45 +/- 1.35 times greater than by the hamstrings.
Torque in extension/flexion and abduction/adduction was also observed,
Conclusion: Our data suggest that limbs with long-term retained IM nails ex
perience a significant reduction in the femur BMD and quadriceps muscle str
ength. These findings may not be simply related to the implant, and further
study is warranted to determine the causes of these changes.