To The Editor:
We found “Long-Term Outcome After Tibial Shaft Fracture: Is Malunion Important?” (2002;84:971-80), by Milner et al., to be quite interesting, but we think that any retrospective study involving the long-term follow-up of malunited fractures is fundamentally flawed by an inherent bias in patient selection. The residual angulation after a fracture heals is either acceptable or unacceptable to both the patient and the treating physician. When it is judged to be unacceptable, it is corrected either for functional or cosmetic reasons. Alternatively, substantial radiographic angulation may be compensated for by adaptations of gait or a reduction in activity level1. If at some later point the limb becomes symptomatic, reliable forms of treatment are again readily available. It would, therefore, be very unusual for a malunited limb with substantial deformity to develop degenerative arthropathy and not be corrected.
The direct deleterious effect of abnormal contact pressure on articular cartilage has been documented repeatedly in animal models2.
Dynamic loading at the knee can be influenced by subconscious control of the limb position, such as foot placement, active muscle contraction, passive soft-tissue stability, as well as the speed of walking3,4. The loads that are generated during these dynamic activities are substantially greater than the loads that can be generated during static postures. Therefore, limb malalignment based on static radiographic measurements provides one component in the complete analysis of the factors influencing loading at the knee joint. Loading at the knee joint is an important consideration in the progression of degenerative processes at the knee. Dynamic malalignment that occurs during activities such as gait should be considered in evaluating the progression or nonprogression of disease processes3,4.
The authors did not receive grants or outside funding in support of their research or preparation of this manuscript. They did not receive payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity. No commercial entity paid or directed, or agreed to pay or direct, any benefits to any research fund, foundation, educational institution, or other charitable or nonprofit organization with which the authors are affiliated or associated.
1. , Paley D. Malalignment and degenerative arthropathy. Orthop Clin North Am.
2. , Billingham ME. Animal models of degenerative joint disease. Curr Top Pathol.
3. , Schipplein OD, Andriacchi TP, Saddemi SR, Weise M. The anterior cruciate ligament-deficient knee with varus alignment. An analysis of gait adaptations and dynamic joint loadings. Am J Sports Med.
4. , Andriacchi TP. Interaction between active and passive knee stabilizers during level walking. J Orthop Res.
5. , Song J, Felson DT, Cahue S, Shamiyeh E, Dunlop DD. The role of knee alignment in disease progression and functional decline in knee osteoarthritis. JAMA. 2001; 286: 188-95.