Aims

The aim of this study was to report the long-term results of rotational acetabular osteotomy (RAO) for symptomatic hip dysplasia in patients aged younger than 21 years at the time of surgery.

Adolescent and young adult patients with a history of DDH and residual hip dysplasia tend to have an early presentation of symptoms. In these patients, a severe acetabular dysplasia, aspheric femoral head and/or high greater trochanter are often observed. We evaluated the long-term results of rotational acetabular osteotomy (RAO) for symptomatic hip dysplasia in patients younger than 21 years.

We performed 492 RAOs for hip dysplasia from 1987 to 2017. In these cases, patients younger than 21 years at the time of surgery were 40 patients (46 hips). We evaluated 34 patients (40 hips, follow-up rate; 85%) retrospectively. There were 32 females and two males; their mean age at the time of surgery was 17.8 years (12–21). The mean follow-up period was 16.8 years (1–30). In eight hips, isolated RAO was not adequate to correct instability and/or congruency. For these hips, four varus femoral osteotomies, two valgus femoral osteotomies and two greater trochanter displacement were combined with RAO.

The mean clinical score (JOA) was improved from 80 to 90 significantly at the final follow-up. The mean CE angle was improved from −3.4 (−35–10) degrees to 27 (8–42) degrees, acetabular roof angle from 30 (15–60) degrees to 6.7 (−3–30) degrees, head lateralization index from 0.665 (0.5–1.0) to 0.614 (0.429–0.7) postoperatively. Radiographic OA progression was observed in four hips, but no hip was converted to THA.

The RAO is an effective technique for surgical correction of a relatively severe dysplastic hip in adolescent and young adults.

The transtrochanteric anterior rotational osteotomy (TRO) was developed by Sugioka as a joint-preserving procedure which prevents further deformity by transposing the necrotic area from a site of primary weight-bearing to a secondary area. We performed this procedure for children and young adults with various hip disorders.

Between 1994 and 2015 we performed TROs on 12 joints in 12 patients with SCFE (4), pigmented villonodular synovitis (2), septic arthritis (1), FAI (1), hip dysplasia (1), femoral neck fracture (2) and postoperative RAO (1). The mean age at the time of surgery was 21 years (10–43) and the mean follow-up period was 8 years (1–22). The rotational directions of the femoral head were anterior (5) and posterior (7). Clinical assessment was undertaken using the system of Merle d'Aubigné and Postel, grading pain, mobility and walking ability with scores from 0 to 6. Radiographically bone regeneration and OA progression were estimated.

The mean clinical score improved from 9.0 to 14.4 at final follow-up. Spur formation of femoral head was observed in 7 patients (58%). OA progression was in two patients (17%) and one patient was converted to THA 22 years after surgery. All cases with osteonecrosis in SCFE and femoral neck fracture showed remarkable bone regeneration.

The TRO is a reliable joint-preserving procedure for various hip disorders in children and young adults.

Objectives

The objective of this study was to investigate the therapeutic effect of peripheral blood mononuclear cells (PBMNCs) treated with quality and quantity control culture (QQ-culture) to expand and fortify angiogenic cells on the acceleration of fracture healing.

The objective of this study is to introduce the forces acting on the knee joint while ascending from kneeling. Our research group has developed a new type of knee prosthesis which is capable of attaining complete deep knee flexion such as a Japanese style sitting, seiza. Yet we could not set up various kinds of simulation or experiment to assess the performance of our prosthesis because the data about joints' forces during the ascent from deep knee flexion are lacking. Considering this circumstance, we created a 2D mathematical model of lower limb and determined knee joint force during ascent from kneeling to apply them for the assessment of our prosthesis.

Ten male and five female healthy subjects participated in the measurement experiment. Although the measurement of subjects' physical parameters was non-invasive and direct, some parameters had to be determined by referring to the literature. The data of ground reaction force and each joint's angle during the motion were collected using a force plate and video recording system respectively. Then the muscle forces and the joints' forces were calculated through our mathematical model. In order to verify the validity of our model approach, we first introduced the data during the activities with small/middle knee flexion such as level walking and rising from a chair; these kinds of data are available in the literature. Then we found our results were in good agreement with the literature data. Next, we introduced the data during the activities with deep knee flexion; double leg ascent [Fig.1 (a)] and single leg ascent [Fig.1 (b)] from kneeling without using the upper limbs.

The statistics of the maximum values on the single knee joint for all the subjects were; during double leg ascent, F_max = 4.6±0.6 (4.3-5.2) [BW: (force on the knee joint)/(body weight)] at knee flexion angle of b =140±8 (134-147)°, during double leg ascent, F_max = 4.9±0.5 (4.0-5.6) [BW] at b = 62±33 (28-110)° for the dominant leg, and F_max = 3.0±0.5 (22.2-3.8) [BW] at b = 138±6 (130-150)° for the supporting leg respectively. We found that the moment arm length, i.e., the location of muscle insertion significantly affected the results, while ascending speeds did not affect the results much. We may conclude that the single leg ascent should be recommended since F_maxdid not become large while deep knee flexion. The values could be used for assessing the strength of our knee prosthesis from the risk analysis view point.

Introduction. Dysplasia of the hip is the commonest cause of secondary osteoarthritis. One treatment is periacetabular osteotomy such as rotational acetabular osteotomy(RAO). These procedures have generally produced satisfactory mid- and long-term results, but unfavorable results have been reported in a few cases. We evaluated the 10-year results to determine the factors of prognostic importance.

Methods. We studied 91 patients (100 hips) at prearthritis or early stage. The mean age at surgery was 36 years (13 – 58) and mean follow-up period was 11 years (8–16). 81 were women (89 hips) and 10 were men (11 hips). Clinical follow-up was done using the system of Merle d’Aubigne. Radiologically, CE angle, AC angle and head lateralization index (HLI) were measured prior to surgery, 3 months postoperatively and at follow-up. Postoperative joint congruencies were classified into four grades.

Results. The mean clinical score significantly increased from 14 to 17 and only in 4 cases the mean score decreased. CE angle, AC angle, and HLI significantly improved after surgery. Progression of osteoarthritis was radiologically observed at follow-up in 7 hips. Kaplan-Meier survivorship analysis predicted the rate of prevention of osteoarthritic progression at 10 years as 93%. Parametric survivorship analysis using the Cox hazards model indicated that postoperative joint congruency is a risk factor for progression of osteoarthritis.

Discussion/Conclusion. Our findings have suggested that RAO is valuable in preventing osteoarthritic progression for at least 10 years. If risk factors can be reduced, a longer operative effect may be expected.