Abstract
This study compared the functional outcomes of total hip arthroplasty (THA) in one hip and extracorporeal shockwave (ESWT) in the other hip in patients with bilateral hip necrosis.
Seventeen patients with bilateral hip necrosis were treated with THA for late stage ONFH in one hip and ESWT for early lesion in the other hip. In THA, only one type of prosthesis was used and all components were cementless. In EWST, each hip received 6000 shocks at 28 Kv (equivalent to 0.62 mJ/mm2 energy flux density) in a single session. The evaluations included pain score, Harris hip score, radiographs and MR images at 6 and 12 months and then yearly.
Significant improvements in pain score and Harris hip score were noted after treatment in both hips. However, the magnitudes of improvement showed significant differences between the two sides favoring the ESWT side. On subjective assessment, 13 patients rated ESWT better than THA; 4 patients reported comparable results of THA and ESWT, and none graded THA better than ESWT. In THA side, abnormal radiographs were noted in 47% (8 of 17) including component mal-position, nonprogressive radiolucency, and suspected component loosening. In ESWT side, significant reduction of bone marrow edema and a trend of decrease in the size of the lesion were observed after treatment.
ESWT and THA are effective for early and late stages of ONFH respectively.
However, better functional outcomes were observed in ESWT-treated hips than hips treated with THA in patients with bilateral hip disease in short-term.
Correspondence should be addressed to Diane Przepiorski at ISTA, PO Box 6564, Auburn, CA 95604, USA. Phone: +1 916-454-9884; Fax: +1 916-454-9882; E-mail: ista@pacbell.net
