The severity and prediction of anterior knee pain post tibial nail insertion.

OBJECTIVES: To compare the prevalence of anterior knee pain and functional impairment post-tibial nailing to the contralateral knee and a background population.
DESIGN: Patients were assessed by postal questionnaire, case note, and radiographic review. An age demographically matched control group answered the same questions.
SETTING: The Orthopaedic Department at our institution. PATIENTS/PARTICIPANTS: Patients who had a tibial nail inserted between September 1999 and November 2004 in our hospital (85 patients). Twelve were excluded, and 52 replies from 73 cases (71%) were received. The mean age was 39.4 years (range 22-69), and 38 of the patients were men. INTERVENTION: Patients treated with AO tibial nail. MAIN OUTCOME MEASUREMENTS: Both knees were assessed using an analogue pain score (0-10) and a functional anterior knee pain score (0-50).
RESULTS: Of the patients, 83% had anterior knee pain following tibial nailing. The mean analogue pain score was 4.3, and the functional score was 33.3. The prevalence of anterior knee pain in the uninjured knee was 40%; in the control group it was 42%. Mean visual analogue scores were 1.3 and 1.2, respectively (both P<0.001 compared to the nailed side). Functional knee pain scores were 43.3 and 46.8 (both P<0.001 compared to the nailed side). Pain scores between both the knee on the injured and the contralateral sides correlated significantly (P<0.01). Last, the pain scores of the patients' knees of the uninjured side in the operative group and the scores from the control group appeared similar but not with statistical significance (P<0.57 analogue pain score and P<0.77 functional knee pain score).
CONCLUSIONS: There is a significant preinjury prevalence of anterior knee pain. Postnailing knee pain severity correlates with that in the uninjured limb. Relative risk of anterior knee pain postnailing is twice that of a comparative population.