Trends and Practices in Limb Lengthening: An 11-year US Database Study

Ab s t r ac t Aim: Over the past couple of decades, limb lengthening has evolved to encompass various implants and techniques. The purpose of this study was to (1) determine trends in the utilisation of various limb lengthening techniques for the femur and tibia in the United States, (2) determine trends in 1-year readmission rate following limb lengthening procedures and (3) to study the relationship of limb lengthening implant used and payment method used with the underlying diagnosis associated with limb shortening. Materials and methods: Inpatient data were acquired using the Healthcare Cost and Utilisation Project (HCUP) database from 2005 to 2015 from seven states in the United States. Patients with an International Classification of Diseases (ICD)-9 code for limb lengthening of the femur or tibia were included. A total of 2,563 patients were included. Data were analysed using descriptive statistics, and chi-square test was used for comparison of subcategories. Linear regression analysis was used to examine trends over time. Results: There was a strong linear trend towards increasing proportional use of internal lengthening of the femur from 2011 to 2015 (R² = 0.99) with an increase of 10.2% per year. A similar trend towards increasing proportional use of internal lengthening of the tibia was seen from 2011 to 2015 (R² = 0.87) with an increase of 4.9% per year. There was a moderate correlation showing a decrease in readmission rate of 1.07% per year from 2005 to 2015 (R² = 0.55). Patients with short stature had increased use of internal lengthening and self-payment compared to patients with congenital, post-traumatic or other diagnoses. Conclusion: There was increasing use of internal lengthening techniques from 2011 to 2015. Patients with short stature had higher use of internal lengthening technique and self-pay for payment method. Clinical significance: Intramedullary devices have seen increasing use for limb lengthening procedures. Lengthening technique and payment method may differ by underlying diagnosis.