The Fate of Iliopsoas Muscle in the Long-term Follow-up After Open Reduction of Developmental Dysplasia of the Hip by Medial Approach. Part 1: MRI Evaluation

Coxa Magna following treatment of developmental dysplasia of the hip: investigation for associated potential factors

Coxa Magna (CM) is defined as a condition in which the horizontal (transverse) diameter of the femoral head is larger on the affected side than on the intact side. CM can occur as a manifestation of avascular necrosis (AVN) following treatment for the developmental dysplasia of the hip (DDH). Alternatively, it can also be secondary to other hip disorders, such as Perthes' disease. This study aimed to determine the prevalence and indicators of CM and AVN of the femoral head that can be detected during follow-up in patients with unilateral DDH treated with closed reduction (CR) or open reduction (OR) surgery. The files of 143 patients treated for unilateral DDH between January 1997 and December 2017 were reviewed retrospectively. A total of 104 patients, including Group 1 ( n = 49) patients who underwent CR under general anesthesia and Group 2 ( n = 55) patients who underwent OR were included in the study. CM; It was considered as the case where the femoral head was 15% or more larger than the intact side. A total of 104 patients were followed up for 77.27 ± 13.96 months, with a mean age of 15.43 ± 7.76 months. When Group 1 and Group 2 were compared, there was no statistical difference in terms of sex, side, adductor tenotomy, and AVN ( P > 0.05). CM developed in 22.4% ( n = 11) of the patients in Group 1 and in 49.1% ( n = 27) in Group 2, and the difference was statistically significant ( P = 0.008). When the effect of independent variables on the development of CM is evaluated with the multivariate logistic regression model, the risk of developing CM is 3474 times higher in those who underwent iliopsoas tenotomy compared with those who did not. The primary outcome of this study is that CM is more frequent in patients treated with OR for DDH. CM may be a nonpathological condition that occurs in connection with iliopsoas tenotomy or surgical treatment. Prospective studies with a larger number of cases, designed to minimize confounding factors, are required.

The tension of the iliopsoas tendon more than doubles during extension of the dysplastic hip in open reduction

The role of the iliopsoas as an obstructing and re-dislocating factor in developmentally dislocated hips is unclear. The purpose of this article is to determine the change in the iliopsoas' tension during flexion and extension when performing an open reduction. We evaluated 34 hips undergoing an anterior open reduction for a developmental dislocation. At the time of surgery, we identified the iliopsoas, and before sectioning it as part of the open reduction, we measured the tension while cycling the reduced hip through flexion and extension. We performed statistical analysis using Pearson and Spearman correlation tests. We created an initial tension artificially at 20 N with the hip held in 90º of flexion, which then doubled to a mean of 42 N when placed in extension. We found a significant increase in tension when the hip went below 20º of flexion. We also found the correlation between the angle of the hip and the force of tension to be statistically significant ( P  = 0.003). This study provides quantitative support that the tension of the iliopsoas tendon increases significantly in extension when performing an open reduction of a developmentally dislocated hip.

What's New in Pediatric Hip?

BACKGROUND

Developmental dysplasia of the hip (DDH), which encompasses a wide spectrum of disease from mild dysplasia to frank dislocation, is one of the most common developmental deformities of the lower extremities and one of the leading causes of future osteoarthritis and hip arthroplasty. Legg-Calvé-Perthes disease (LCPD) results from a vascular insult to the growing femoral epiphysis, which in turn can create permanent morphologic changes to the hip joint. Slipped capital femoral epiphysis (SCFE) occurs when the proximal femoral physis fails allowing the epiphysis to displace in relation to the metaphysis. Infections about the hip also create significant morbidity in the pediatric hip.

METHODS

We searched the PubMed database for all studies related to DDH, LCPD, SCFE, and pediatric hip infections that were published between July 1, 2014 and August 31, 2017. The search was limited to English articles and yielded 839 papers. This project was initiated by the Pediatric Orthopaedic Society of North America Publications Committee and was reviewed and approved by the Pediatric Orthopaedic Society of North America Presidential Line.

RESULTS

A total of 40 papers were selected for review based upon new and significant findings. Select historical manuscripts are also included to provide sufficient background information.

CONCLUSIONS

DDH, LCPD, SCFE, and infections about the hip continue to be important topics in pediatric orthopaedics and areas of vital research. This manuscript reviews the most important recent literature on the diagnosis and treatment of these pediatric hip conditions.

LEVEL OF EVIDENCE

Level V.