We utilized a dry-bone model of the pelvis and proximal femur, set upon transparent Lucite plates with four mounting screws and adjustable struts, allowing measurable and reproducible pelvic tilt and rotation. Our protocol for osteotome placement at each of the osteotomy sites strictly followed the technique described by Ganz. A 30°, 15 mm bifid osteotome was used for imaging at the initial ischial osteotomy at the infracotyloid groove. A 30°, 2 cm straightedge osteotome was placed 4 cm below the pelvic brim to image the retroacetabular osteotomy on the quadrilateral plate. Various osteotome placements were imaged with the C-arm image intensifier to better define the risks of inferior and posterosuperior intraarticular osteotomies at each of these sites, respectively. A 600 osteotome oriented at 500 to the quadrilateral plate was also utilized.

In addition, violation of the inferior quadrant of the joint as well as posterolateral slipping of the osteotome blade along the posterior column, were appreciated on all images of pelvic flexion and rotation. The false-profile view always confirmed the perpendicular orientation of the osteotome blade. The false-profile view allowed for accurate evaluation of the positioning of the 30°, 2-cm straightedge osteotome along the retro-acetabular osteotomy site. In the views obtained, the blade could be seen aligned parallel to the posterior surface of the acetabulum, while respecting the posterosuperior joint space with optimal step-off from the posterior column. False-profile and posterior judet views provided optimal visualization of the 60° osteotome on the quadrilateral plate. In addition, pelvic flexion and rotation did not impact the ability to visualize the inferior margin of the acetabulum in evaluating the potential for creating an inferior intraarticular osteotomy. The results of our study indicate that awareness of the appearance of ideal osteotome placements at each osteotomy site on AP and false profile C-arm image intensification will decrease the incidence of iatrogenic osseous and therefore neurovascular complications reported in the literature and reduce post-operative patient morbidity.

To evaluate the correction of complex congenital deformities of the lower limb by six axes deformity analyses and computer assisted correction using the Taylor TM Spatial Frame (TSF), from 1998 to 2000, the authors performed corrections of multiple congenital deformities in 24 lower limbs in 18 patients. There were 9 males and 9 females. There were a total of 29 bone segments, (8 femurs, 21 tibiae) in the 24 lower limbs that were corrected with application of the TSF. Our series included the following diagnoses and deformities: unknown skeletal dysplasia (2), achondroplasia (3), pseudoa-chondroplasia (1), multiple epiphyseal dysplasia (2), spondyloepiphyseal dysplasia (2), fibular hemimelia (3) tibia hemimelia (1), hypophosphatemic rickets (3), and posteromedial bowed tibia (1).

The mean age of the patients was 15.4 years (range 0.5 to 35 years). The mean frame time until correction was 20.1 weeks (range 9 to 49 weeks). The mean follow up was 2.4 years (range 2 to 3.4 years). The apex of the deformity was directed posteromedial in 7, anterolateral in 6, medial in 5 and anteromedial in 5 patients. The mean coronal and sagittal plane deformities were 14.60 (range −230 to 400) and 70 (range, −400 to 280), respectively. The average magnitude of the deformity was 21.70 (range 90 to 470), and the plane of the deformity to the coronal plane was −23.30 (range −800 to 400). Eight patients had a mean lower extremity shortening of 12.3 mm (range 5 to 50 mm). One patient had 15° of internal rotation. With application of the TSF and the principles of distraction osteogenesis, we were able to reduce the coronal and sagittal plane deformities to 3.10 and 1.40 respectively. The overall mean magnitude of the deformity was decreased to 3.40. Shortening was corrected to an average of 3 mm. We experienced only 4 complications in the 24 limbs (16.7%). Complications in this patient group included one female patient with hypophosphatemic rickets who had residual deformity with significant lateral mechanical axis deviation due to inadequate translation. In addition, there were two superficial pin tract infections and one delayed union.

Computer-assisted six axes deformity planning and TaylorTM Spatial Frame application effectively and safely correct complex congenital and developmental limb deformities and offer significant advantages over the well-established Ilizarov technique.

The role of femoral and acetabular version in correction of dysplasia of the hip has been undereported. Between June 1995 and September 2000, a Bernese periacetabu-lar osteotomy (BPO) was performed in 25 patients (26 hips) by the senior author with an average follow-up of 3.7 years (range 2-5 years). The mean age of the patients (24 female, 1 male) at the time of surgery was 29.4 years (range, 11.5 to 45 years). Only patients with a primary diagnosis of acetabular dysplasia were included in this series.

The average Harris hip score increased from 55.1 (range 34–75) preoperatively to 92.9 (range 72–100) at the latest follow up (p< 0.0001). The mean pre-operative Merle d’Aubign score increased from 13.5 (range 10–15) to 17 (range 15–18) at the latest follow up. The mean lateral centre edge angle of Wiberg increased from 13.10 (range 00–200) pre-operatively to 52.60 (range 200-740) at latest follow-up (p< 0.0001). The anterior centre edge angle averaged 10.90 (range 4-170) pre-operatively and improved to 490 (range 210–760) at latest follow-up (p< 0.0001). The Mckibbin instability index is the sum of femoral and acetabular version (normal range 200–500). There were 6 hips with low instability index and 11 hips with high instability index pre-operatively. At the latest follow-up there were only 2 hips with low instability index and there were no patients with a high instability index. Our clinical results showed fi fteen patients with excellent results, eight good results and one fair and one poor results. Thus, overall good to excellent results were obtained in 92% of our patients. It is therefore possible that we had higher success rate in our series than that reported in other series because of the correction of version of the hip in addition to the coronal and sagittal defi ciency of the hip.

The aim of our study was to assess the efficacy and complications of treatment of limb deformities using six axes deformity analysis and the Taylor TM Spatial Frame [TSF]

Between January 1997 and March 2000, we treated 75 lower limbs in 66 patients with deformities. Patients were divided into four groups. The groups were Blount’s disease, congenital deformities, traumatic deformities, and a miscellaneous group. The data was prospectively collected. This was a consecutive series of the first 66 patients treated at our institution with the TSF. Deformity correction using the TSF is done with the aid of computer software.

The mean age of the 66 patients was 18.7 years (range 0.5 to 72 years). The average frame time was 18.6 weeks (range 9 to 49 weeks). There was shortening present in 31 limbs with a mean of 18.6 mm (range 5 to 50 mm). Deformity correction with distraction osteogenesis was begun 7 days after the osteotomy. The mean length of time until correction was 6.7 weeks (range 3 to 13 weeks). There were a total of 10 complications (13.3%) in the series.

27 tibiae in 23 patients underwent correction with the TSF for Blount’s disease. There were 11 infantile and 16 adolescent forms. Correction of congenital deformity was performed in 20 tibiae and 8 femurs in 18 patients. There were 9 males and 9 females. There were 13 male and 8 female patients with traumatic lower limb injuries. There were 11 malunions and 10 nonunions (including 2 infected nonunions) that were corrected with the TSF.

The TaylorTM Spatial Frame is an effective technique in treating deformity. Angulation, translation, shortening and rotation can be corrected simultaneously.

Based on our results, we conclude that the TSF allows safe, gradual correction that is accurate and well tolerated.