Does Perfusion MRI After Closed Reduction of Developmental Dysplasia of the Hip Reduce the Incidence of Avascular Necrosis?

Abstract

Background Gadolinium-enhanced perfusion MRI (pMRI) after closed reduction/spica casting for developmental dysplasia of the hip (DDH) has been suggested as a potential means to identify and avoid avascular necrosis (AVN). To date, however, no study has evaluated the effectiveness of pMRI in clinical practice or compared it with other approaches (such as postreduction CT scan) to show a difference in the proportion of AVN. Questions/purposes (1) Can a pMRI-based protocol be used immediately post closed reduction to minimize the risk that AVN would develop? (2) What are the overall hiprelated outcomes after closed reduction/spica casting using this protocol? (3) Do any patient-specific factors at the time of closed reduction predict future AVN? Methods This was a retrospective cohort study at a large tertiary care children's hospital. Between 2009 and we treated 43 patients with closed reduction/spica casting for DDH, of whom 33 (77%) received a postreduction pMRI. All patients were indicated for pMRI per treating surgeon preference. A convenience sample totaling 25 hips in 22 patients treated with pMRI was then established using the following exclusion criteria: DDH of neuromuscular/ syndromic origin, failed initial closed reduction, less than 1 year of clinical and radiographic followup, and subsequent open reduction. Next, the 40 patients treated with closed reduction between 2004 and 2009 were screened until the chronologically most recent 25 hips (after applying the previously mentioned exclusion criteria) were identified in 21 of the first 34 patients (62%) screened. Although termed the CT group, specific postreduction imaging was not a defined inclusion criterion in this group with the majority (21 of 25 [84%]) receiving postreduction CT and the remainder (four of 25 [16%]) receiving only postreduction radiographs. All hips with globally decreased femoral head perfusion on postreduction pMRI were treated with immediate cast removal followed by repeat closed reduction or open reduction, as per surgeon preference, with two of 33 (6%) requiring such further interventions. Salter criteria were then used to determine the proportion of AVN on radiographs at 1-year and final followup. Secondary outcomes including residual dysplasia and the need for further corrective surgery were ascertained through radiographic and retrospective chart review. 049). No patient with normal perfusionEach author certifies that he or she, or a member of his or her immediate family, has no funding or commercial associations (eg, consultancies, stock ownership, equity interest, patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article. All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research 1 editors and board members are on file with the publication and can be viewed on request. Each author certifies that his or her institution approved the human protocol for this investigation and that all investigations were conducted in conform...

Timing for closed reduction procedure for developmental dysplasia of the hip and its failure analysis

“…Similar to our results, it was also reported in previous studies [9,17,20] that age was not the risk factor of AVN after CR, while other studies gave the opposite conclusion [11,21,22]. The rate of AVN (15.4%) in this study falls into the range of the previously reported studies (10-33%) [7,[23][24][25][26]. The most common cause of AVN is the immobilization in a position that places excessive pressure on the femoral head.…”

Timing For Closed Reduction of Developmental Dysplasia of the Hip and Failure Analysis

“…Similar to our results, age was not found to be the risk factor of AVN after CR also reported in other literatures [9,15,20]. The rate of AVN (18.6%) in this present study was similar to previously reported studies (10%-33%) [7] [21][22][23][24]. The most common cause is the immobilization in a position that places excessive pressure on the femoral head.…”

Timing for Closed Reduction Procedure for Developmental Dysplasia of the Hip and its Failure Analysis

“…Although in our study age does not play as a signi cant risk factor for AVN and re-dislocation, Similar to our results, it was also reported in previous studies [9,17,22] that age was not the risk factor of AVN after CR, while other studies gave the opposite conclusion [11,20,21]. The rate of AVN (15.4%) in this study falls into the range of the previously reported studies (10%-33%) [7] [23][24][25][26]. The most common cause of AVN is the immobilization in a position that places excessive pressure on the femoral head.…”