Glenoid baseplate positioning for reverse total shoulder replacements (rTSR) is key for stability and longevity. 3D planning and image-derived instrumentation (IDI) are techniques for improving implant placement accuracy. This is a single-blinded randomised controlled trial comparing 3D planning with IDI jigs versus 3D planning with conventional instrumentation. Eligible patients were enrolled and had 3D pre-operative planning. They were randomised to either IDI or conventional instrumentation; then underwent their rTSR. 6 weeks post operatively, a CT scan was performed and blinded assessors measured the accuracy of glenoid baseplate position relative to the pre-operative plan. 47 patients were included: 24 with IDI and 23 with conventional instrumentation. The IDI group were more likely to have a guidewire placement within 2mm of the preoperative plan in the superior/inferior plane when compared to the conventional group (p=0.01). The IDI group had a smaller degree of error when the native glenoid retroversion was >10° (p=0.047) when compared to the conventional group. All other parameters (inclination, anterior/posterior plane, glenoids with retroversion <10°) showed no significant difference between the two groups. Both IDI and conventional methods for rTSA placement are very accurate. However, IDI is more accurate for complex glenoid morphology and placement in the superior-inferior plane. Clinically, these two parameters are important and may prevent long term complications of scapular notching or glenoid baseplate loosening. Image-derived instrumentation (IDI) is significantly more accurate in glenoid component placement in the superior/inferior plane compared to conventional instrumentation when using 3D pre-operative planning. Additionally, in complex glenoid morphologies where the native retroversion is >10°, IDI has improved accuracy in glenoid placement compared to conventional instrumentation. IDI is an accurate method for glenoid guidewire and component placement in rTSA.
The Pelvic Support Osteotomy (PSO) or Ilizarov Hip Reconstruction(IHR) is well described for the treatment of septic sequelae of infancy. The purpose of this study was to clinically, functionally and radiographically assess our short-term results of this procedure. 25 patients (16 boys, 9 girls) who had undergone a IHR using the Ilizarov/TSF construct over a period of 10 years for a variety of pathologies were reviewed. The mean age at surgery was 15 years 4 months. The pre-operative diagnoses were SCFE(10), hip sepsis (6), DDH (6) and Perthes (3). All had significant leg length discrepancies, 16 had a painful stiff hip, 6 had a painful mobile hip and 3 had a painless unstable hip. At surgery, a mean measured proximal valgus angle of 51° and a mean extension angle of 15° was achieved. Distal femoral lengthening averaged 4.2 cm and distal varus correction was a mean of 8°. The mean fixator time was 173 days. At a mean of 2 years and 7 months follow-up the lower-extremity length discrepancy had improved from a mean of 5.6 cm apparent shortening to 2.3 cm. Trendelenberg sign was eliminated in 18/25 cases. Improvements in range of hip movements and gait parameters were observed. Stance time asymmetry, step length asymmetry, pelvic dip and trunk lurch improved significantly. One patient had conversion to a total hip replacement after 7 years, 4 patients required re-do PSO due to remodelling of the proximal osteotomies, two had heterotopic ossification and two had significant knee stiffness due to lack of compliance. The early results of IHR are encouraging to equalise limb lengths, negate trendelenburg gait, provide a mobile hip with a reasonable axis and the possibility of conversion to THR in the future if needed. Complications need to be anticipated and the effects of remodelling and maintaining adequate knee range of motion must be emphasised.
