A fully implantable motorized distraction nail used in patients with hip dysplasia who are undergoing total hip arthroplasty may reduce the risk of later hip dislocations. This type of nail, which provides continuous soft tissue distraction and acute intraoperative stretching, allows patients to attain equal leg length, according to results presented at the Limb Lengthening and Reconstruction Society Annual Scientific Meeting.
“If the hip is not in the right anatomic position, this procedure is helpful to use before you do the hip replacement and not to try an acute distalization through this surgery, because if you do that you have a high risk of getting nerve damage and that has to be avoided,” Rainer P. Baumgart, MD, told Healio.com/Orthopedics.
Baumgart and his colleagues use a fully implantable motorized distraction nail in 14 patients with hip dysplasia who were undergoing THA. Researchers then resected the femoral head and implanted the THA cup in an anatomic position with or without enhancement of the acetabulum.
Postoperative distraction was done at 2-mm per day, which completely compensated for any proximal migration, according to the findings. In a second surgical procedure, researchers removed the distraction nail and inserted the stem to complete the THA.
Results showed all patients could undergo THA that involved components that were anatomically positioned. Researchers found no patients with any reported infections., however, five patients had high pain levels due to how rigid the connection to their pelvis was.
Despite the few patients studied, Baumgart said improvement in their management could be seen on a case-to-case basis. Future goals for use of this technique are to determine which approaches work best for each type of patient anatomy. – by Casey Tingle
Baumgart RP, et al. Hip dysplasia — reduction of proximal migration before arthroplasty using a fully implantable motorized distraction nail. Presented at: Limb Lengthening and Reconstruction Society Annual Scientific Meeting; July 13-14, 2018; San Francisco.
Disclosure: Baumgart reports he receives IP royalties from, is a paid consultant for and is a paid presenter or speaker for implantcast and Wittenstein intens.