Assessing leg length discrepancy after femoral fracture: clinical examination or computed tomography?

INTRODUCTION: Femoral shaft fractures treated with intramedullary nailing often heal with a leg length discrepancy (LLD). LLD is commonly evaluated by clinical examination and computed tomography (CT) scanogram. We assessed the correlation between these two techniques of calculating LLD. METHODS: We reviewed 35 skeletally mature patients who sustained a femoral shaft fracture between January 1997 and December 1999. Leg length was measured clinically with direct measurement and a block test. Each patient was asked whether they felt they walked with a limp and whether they felt they had a leg length discrepancy. Each patient underwent a CT scanogram to measure femoral and total leg length. The correlation between clinical examination and scanogram was analysed using the Pearson Product Moment Correlation. RESULTS: Of the 35 patients, 15 patients (43%) had a measurable LLD. There was a positive correlation between direct leg length measurement and the block test (P = 0.003), and between the block test and patient perception of limp and LLD. CT scanogram was performed on 29/35 patients. There was no correlation between CT scanogram and clinical measurement of leg length or between CT scanogram and patient perception of LLD or limp. DISCUSSION: Leg length discrepancy commonly occurs following treatment of femoral shaft fractures. We found that there was a strong correlation between direct leg length measurement and the block test, and between both methods of clinical leg length measurement and patient perception of a limp or LLD. Our study found no correlation between CT scanogram and clinical leg length measurement or patient perception of limp or LLD. CONCLUSION: Our study shows that physical examination (direct measurement and the block test) is more reliable and clinically relevant than CT scanogram measurement in the assessment of LLD after femoral fracture.

Outcome after intramedullary nailing of femoral shaft fractures.

BACKGROUND: The results of intramedullary nailing of femoral shaft fractures from Australian institutions have not been widely reported. This study examines a consecutive group of patients treated at a major metropolitan trauma centre and reports on the injury statistics and outcome data, and compares this to previously reported results from the literature. METHODS: A total of 101 fractures in 97 consecutive adult patients were included in the study. Nine patients were excluded. At a minimum of 6 months post injury, 54 patients were interviewed by telephone and 35 patients presented for clinical review and underwent physical examination, computed tomography (CT) scanogram of the lower limbs and Short Form 36 questionnaires. RESULTS: Road trauma accounted for 81% of injuries and 15% of fractures were open. Of the 54 patients reviewed, 13 (23%) required further surgery for delayed or non-union. Of the 35 who presented for physical examination, there was poor correlation between perceived leg length discrepancy and measured leg length discrepancy on examination or scanogram. Presence of a limp correlated with measured leg length discrepancy of more than 1 cm but did not correlate with rotational abnormality measured on CT scanogram. Pain at the hip, thigh or knee was present in 60% of patients. The Short Form 36 scores for physical functioning, role--physical, bodily pain, general health and vitality were all significantly lower than population norms with P values ranging from <0.001-0.05. Subgroup analysis comparing isolated femur fracture to multi-trauma patients for all five of these parameters revealed significant differences only in the multi-trauma group. CONCLUSION: The incidence of pain, limp, leg length discrepancy and delayed or non-union is higher in this study than in previously reported results of intramedullary nailing for femoral shaft fractures. This may be due to differences in the patient population, the skill level of the operating surgeon, or incomplete follow up.