Background Several mechanical derangements reportedly contribute to the development of noninflammatory arthritis of the hip. Diagnosis of these derangements involves the use of specific radiographic measures (eg, alpha angle, lateral center edge angle, cross-over sign). The reliability of some of these measures is not known, whereas others have not been confirmed. Questions/purposes We examined the reproducibility of 20 radiographic parameters of the hip used in clinical practice. Methods Twenty radiographic parameters on standardized digital AP and cross-table lateral radiographs were evaluated by two observers on two different occasions. The parameters were evaluated from the standpoint of reproducibility (reliability and agreement). The intraclass correlation coefficient (ICC), kappa coefficient, and standard error of measurement were calculated. The minimal detectable change was calculated where possible. Results Interrater reliability ranged from 0.45 to 0.90 for ICC depending on the measure. Intrarater reliability ranged from 0.55 to 0.99. Measurements that could be measured directly (femoral head diameter) were more reliable than measurements requiring estimation on the part of the observer (Tönnis angle, neck-shaft angle). Categorical parameters had interrater and intrarater reliability kappa values greater than 0.90 for all parameters measured. Agreement between repeated measurements, as given by the minimal detectable change, showed many parameters with low absolute reliability have clinical use in the context of the large changes seen in clinical practice.

Revision total hip arthroplasty through the direct anterior approach is technically challenging but offers some advantages in exposure of the acetabulum. This study presents a retrospectively reviewed consecutive series of fifty-one patients who underwent revision total hip arthroplasty through the anterior approach utilizing various extensions of this technique. The anatomic approach is discussed as well as problems as encountered in our series.

A 16-year-old boy sustained a traumatic posterior dislocation of the right hip. After initial closed reduction, the hip spontaneously redislocated within 2 days. Four days after the initial dislocation, the patient was transferred to the authors' institution, where a radiographic workup showed a severe capsular and labral disruption from the posterior aspect of the acetabulum. Subsequently, the patient underwent operative treatment using the technique of surgical hip dislocation through a digastric osteotomy as described by Ganz. Using this approach, the avulsed capsulolabral complex as well as the pathological head-neck junction, which is suspected to be a lever for the femoral head, could be fully addressed. The authors recommend further radiographic studies to evaluate the underlying pathology in traumatic dislocation of the hip as well as the described surgical approach, which leads to successful treatment of the entire pathology.

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Numerous techniques exist to correct pediatric angular deformity by asymmetrically inhibiting physeal growth. Despite decades of surgical experience, little is known about the determinants of success or failure of temporary hemiepiphysiodesis. We lack a basic understanding of tolerances and kinematics of the surgically restrained physis. Furthermore, little is known about the influence of implant design and placement on efficacy of deformity correction and rebound growth. We have undertaken a pilot research study with the goal of producing genu valgum in New Zealand white rabbits. This report comprises our initial experience and observations in performing hemiepiphysiodesis with staples and 2-hole plate techniques. The experimental hypotheses proposed by this article are as follows: (1) a staple or plate applied to the proximal lateral tibial physis of a rabbit hind limb will reliably create a valgus deformity of the knee; (2) the plate or staple will create this deformity without permanently damaging the proximal tibial physis; and (3) provided the implant remains in situ, there will be no difference between the plate and staple constructs with respect to the magnitude or rate of deformity produced. Further studies will aim to use this model to investigate technical issues related to physeal instrumentation.

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