Treatment of Crowe type Ⅳ developmental dysplasia of the hip with total hip arthroplasty after limb-lengthing with external fixator / 中华骨科杂志

ABSTRACT

Objective To retrospectively analyze the methods and clinical outcome to treat Crowe type Ⅳ developmental dysplasia of the hip (DDH) in young adults with total hip arthroplasty (THA) after limb-lengthing with external fixator.Methods From October 2007 to January 2012,12 patients with unilateral Crowe type Ⅳ DDH were treated with two-staged surgical method in our department.There were 2 males and 10 females with an average age of 25.7 years (range,18-35 years).In the first stage,the patients underwent soft tissue relaxation and iliofemoral distraction with use of an external fixator for 10-17 days.There were 1-2 cm distraction at the first time and 3-5 mm daily distraction.When the femoral head was distracted to the level of anatomical position,the second stage-THA was performed.All patients underwent uncemented prosthesis with bulk femoral head autograft for acetabular reconstruction.The acetabular cup was placed in the anatomical position in every patient.Shortening femoral osteotomies were not required.Results The mean time of first operation was 35.2±3.6 min,and hospital stay was 13.3±1.6 days.The mean time of second operation was 77.3±12.4 min,and hospital stay was 9.2±2.5 days.The average follow-up was 13.6±3.2 months,limb-length discrepancy was 5.6±1.5 cm on average preoperatively and 0.5±0.2 cm on average postoperatively.The Harris hip score was increased from 45.7±2.6 preoperatively to 92.3±3.3 postoperatively.All of the cases had acquired good hip and knee function.No patient suffered pin-site infection,hip joint infection,prosthesis loosening or deep vein thrombosis in our research.Transient nerve palsy occurred during the leg limb lengthening in 3 cases; calf skin numbness after THA occurred in 5 cases.Conclusion For the Crowe type Ⅳ DDH in young adults,normal limb length can be restored nearly and avoid nerve injury via continuously limb-lengthing with external fixator before THA.This method can get precise results,improve limb function significantly and have fewer complications.