Reliability of a new method for lower-extremity measurements based on stereoradiographic three-dimensional reconstruction.

INTRODUCTION: Several clinical and radiological techniques have been described to assess lower limb length and angle measurements. None of them has yet met the ideal criteria for a reliable, reproducible, safe, and inexpensive system. In this context, a new biplanar X-ray system (EOS™, EOS imaging, Paris, France) makes it possible to obtain a 3D reconstruction of the lower extremities from two 2D orthogonal radiographic images, with associated calculation of 3D measurements. The reliability of this technique has never been documented on adults. HYPOTHESIS: Lower limb measurements produced by the 3D EOS™ reconstruction system are reproducible regarding inter- and intraobserver assessment and more reliable with this 3D technique than when they are obtained from 2D measurements. MATERIALS AND METHODS: This study included 25 patients awaiting total hip arthroplasty (50 lower limbs). Two independent observers made all measurements twice, both on the 2D frontal radiograph and using 3D reconstructions (femoral measurements of length, offset, neck shaft angle, neck length, and head diameter, as well as the tibia length, limb length, HKA and HKS). Reproducibility was estimated by intraclass correlation coefficients. RESULTS: Both the inter- and intraobserver reproducibility of the EOS™ measurements was excellent; more specifically inter- and intraobserver reproducibility was 0.997 and 0.997 for femoral length, 0.996 and 0.995 for tibial length, 0.999 and 0.999 for limb length, 0.894 and 0.891 for HKS, 0.993 and 0.994 for HKA, 0.870 and 0.845 for femoral offset, and 0.765 and 0.851 for neck shaft angle. For most of the variables, the interobserver correlations were statistically better with the EOS™ 3D reconstruction. DISCUSSION: Our results show that the EOS™ systems allow reproducible lower limb measurements. Furthermore, 3D EOS™ reconstructions offer better reproducible measures for most of the parameters than radiographic 2D projection. Its use before deciding on surgery and during planning for lower limb arthroplasty appears essential to us. LEVEL OF EVIDENCE: Level III: diagnostic prospective study on consecutive patients.

Vertebral body cage use in thoracolumbar fractures: outcomes in a prospective series of 23 cases at 2 years' follow-up.

INTRODUCTION: One objective of surgery in thoracolumbar spine fracture is to restore correct and lasting spinal statics. This may involve vertebral body replacement using an anterior approach. We here report results on a prospective series of 23 trauma patients managed by vertebral body replacement using an expandable cage. PATIENTS AND METHODS: The sex ratio was 2.28. Fifteen cases involved primary treatment of recent fracture and eight secondary surgery for non-union or malunion. In 12 cases, posterior osteosynthesis was associated. Six patients were operated on using a classical approach and 17 using a video-assisted minimally invasive approach. Pre- and perioperative data were recorded, with clinical scores (VAS and Oswestry) at 6 weeks, 3 months, 6 months, 1 year and 2 years. Radiologic follow-up assessed regional traumatic kyphosis (RTK), enabling calculation of regional traumatic angulation (RTA), with control CT to check fusion. RESULTS: Minimum follow-up was 2 years. There were no cases of postoperative neurological deterioration. There were three major postoperative complications: one hemothorax, one adhesive bowel occlusion, and one bilateral pneumothorax at 1 month. Mean Oswestry score at 6 months was 20%, and mean VAS score at 2 years was 0.36. Postoperative RTA showed a mean 7.34° improvement. Mean RTA reduction loss was 1.95° at 3 months, subsequently unchanged. All arthrodeses showed fusion at 6 months. CONCLUSION: Results were satisfactory with this technique, comparable to those reported in the literature. The development of minimally invasive approaches and improved instrumentation procedures optimize surgery and enhance anterior reconstruction tolerance. Lasting restoration of sagittal spinal curvature improves trauma patients' functional recovery.

Complications following rotating hinge Endo-Modell (Link) knee arthroplasty.

BACKGROUND: Rotating hinge knee prostheses are indicated in revisions especially when major ligament laxity or substantial AP deformities are present. These situations make ligament balancing difficult with less constrained design implants. Despite its use for nearly 50 years, this type of prosthesis continues to have a poor reputation due to a high complication rate. HYPOTHESIS: Complications are frequent after this type of arthroplasty and the complication rate is similar in primary or revision arthroplasties. The objective of this study is to report the medium-term results of these implants and determine the eventual predictive factors of complications in order to refine operative indications. MATERIAL AND METHODS: In this retrospective study of patients operated on between 1998 and 2006, 85 Endo-Modell (Link) rotating hinge knee prostheses had been used in 61 females and 24 males. The mean age at surgery was 72.4 years (range, 32-92 years). Fifty-two arthroplasties were primary and 33 were revisions either for loosening (24) or deep infections (9). The mean follow-up was 36 months+/-22 (range, 0-75 months). RESULTS: Complications were observed in 24 patients (28.2%): nine deep infections, four patellar complications, and three cases of aseptic loosening. No significant difference was found between the primary arthroplasties and the revisions regarding all complication types. A significant relation was established between the occurrence of a complication and presence of several associated comorbidity factors (obesity, heart disease, diabetes, etc.). DISCUSSION: The use of this type of implant carries a high risk of complications, higher than the one pertaining to unconstrained design prostheses; this fact is noted irrespective of the surgical indication and other comparison elements. The leading criteria to poor functional results appear to be the indication (gonarthrosis with substantial ligament laxity at primary surgery) and the number of associated comorbidities. These prostheses should therefore be restricted to selected indications, notably in view of the fact that less constrained prostheses give superior outcomes. LEVEL OF EVIDENCE: Level IV. Retrospective therapeutic study.