Commentary & Perspective on
"Anterior Knee Pain After Intramedullary Nailing of Fractures of the Tibial Shaft. A Prospective, Randomized Study Comparing Two Different Nail-Insertion Techniques"
By Jarmo A.K. Toivanen, MD, PhD, et al.

Commentary & Perspective by
Michael A. Banks, MD*, and Mark A. Panigutti, MD*

The authors performed a prospective, randomized study to compare the effects of two surgical approaches on the prevalence and the intensity of anterior knee pain following intramedullary nailing of a tibial shaft fracture. They randomized patients equally to treatment with either a paratendinous approach or a transtendinous approach. The follow-up evaluations included use of a visual analog scale for the quantification of anterior knee pain; the standardized scoring systems of Lysholm and Gillquist and Tegner et al. and the Iowa knee score for quantification of functional results, and isokinetic muscle-strength testing. Nearly all of the tibial nails were removed at an average of eighteen months after insertion and then the patients were re-evaluated. Anterior knee pain was reported in approximately 70% of all patients in both the paratendinous and transtendinous groups at the time of final follow-up. The knee scoring systems, muscle-strength measurements, and functional tests showed no significant difference between the two treatment groups. The authors concluded that there was no difference between the two surgical approaches in the outcome of anterior knee pain after intramedullary nailing of tibial shaft fractures.

The prospective, randomized design of this study distinguishes it from the majority of studies on knee pain after intramedullary nailing, which were retrospective. Also, the authors of this study took great care to document anterior knee pain with use of a visual analog scale and to measure functional results with use of standardized scales and functional muscle testing. The authors also assessed the effect of nail protrusion on pain and they showed that even with no protrusion of the nail, anterior knee pain was a significant problem. Thus, factors other than nail protrusion or the surgical approach must account for anterior knee pain. One source of confusion in the study was the report of significant pain relief after nail removal. The authors stated in the Results section that after nail removal more than 64% of the patients (twelve of eighteen in the transtendinous group and eleven of seventeen in the paratendinous group) had complete or marked resolution of anterior knee pain. Yet, in the Discussion, they stated that the majority of patients still had anterior knee pain after nail removal.

In our patients, pain frequently lessens after nail removal but does not totally resolve, suggesting that the inserted nail is a factor but is not the sole cause of the pain. Also, the results of functional muscle testing were similar for the different approaches, with a mean peak torque deficit recorded for the injured limb, especially for the quadriceps. This deficit may indicate that the surgery affects quadriceps function, which may be a factor in the anterior knee pain.

Our clinical experience correlates very well with the findings of Toivanen et al. in that nail removal may result in a partial reduction of anterior knee pain, but in general, the majority of patients continue to have anterior knee pain after removal of the nail. The anterior knee pain that occurs after intramedullary nailing of the tibia in this study, and in our own clinical experience, is rarely severe, but it does occur in the majority of these patients. We also agree that there is no obvious difference between either approach with regard to reduced anterior knee pain. It is our opinion that anterior knee pain after intramedullary nailing of the tibia is multifactorial. Common to both approaches are local trauma to the extensor mechanism and resultant scar formation in this area, dysfunction of the extensor mechanism, changes in patellofemoral loading after nailing, and injury to the infrapatellar branch of the saphenous nerve. Though we do not routinely advise removal of the nail for relief of anterior knee pain, if the nail is prominent we would recommend removal. We also agree that further studies are needed to assess the role of these factors in the persistence of anterior knee pain in patients who have been treated with intramedullary nailing of tibial shaft fractures.

*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.