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Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_IV | Pages 466 - 466
1 Nov 2011
McGann W Peter J Liddle K Currey J Marmor M Buckley J
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Achieving the correct inclination angle for the acetabular component in total hip arthroplasty (THR) can be technically challenging. The aim of this study is to validate the use of a simple, laser-guided system to address the acetabular cup inclination angle intraoperatively and quantify its accuracy and repeatability across users.

A simple inclinometer system was manufactured, consisting of a laser that snaps into both the inclinometer and the handle of a standard trial cup impacter. The system functions as follows:

desired inclination angle is set on the inclinometer,

inclinometer is positioned on the acetabulum,

laser beam is projected onto and marked on a screen outside of the surgical exposure,

the impacter is reoriented in the acetabulum until the laser beam aligns with the recorded mark on the screen.

A validation study was performed on this system using intact cadavers (N=4). A THR-specific. Trial acetabular components were installed unilaterally in each donor using both the laser inclinometer system with an in-line mounted intraoperative navigation system (NaviVision, Vector Vision Hip 3.1, BrainLab) serving as the measurement standard. Three orthopaedic surgeons participated in the study, two experienced with the device (“experts”) and one “novice”, and each surgeon performed two sequential validation experiments:

10 trials at a set device inclination angle, and

5 trials of matching the trial cup placement to this set angle.

Using the laser-guided system, the inclination angle of the trial cup deviated from the desired orientation by 1.1±0.9° (mean st. dev; range: 0–3°) for all specimens across all operators. The corresponding error in anteversion angle was 1.4±1.3° (range: 0–5°). There was no difference in inclination angle between expert and novice surgeons (1.0±0.8° versus 1.1±1.2°, respectively; p> 0.10 for unpaired t-test). To set the desired inclination angle on the trial cup, original and final laser target positions were within 4.1±2.5 cm at 1 m screen placement.

Results suggest that the laser-guided system has sufficient accuracy and repeatability for use intra-operatively. Inclination angles differed from prescribed angles by 1° on average, and malalignment in anteversion was subclinical, ≤5° for all cases. Furthermore, the tolerance for laser re-alignment sufficiently large (5–10 cm) to make the device functional intraoperatively. Future work will focus on expanding the sample size and correcting simple design limitations in the device.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_I | Pages 14 - 14
1 Mar 2008
Giannikas K Karski M Khan A Buckley J Wilkes R Hutchinson C Freemont A
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While the early period of distraction osteogenesis has been extensively investigated, there are very few data describing the long-term morphology of the regenerate. We performed magnetic resonance scans in ten adults (men age 35+− 11 yr), seven of whom had bone transport for an iatrogenic osseous defect while further three had tibial lengthening for limb length discrepancy. Follow-up ranged between 14 and 43 months (mean : 28 + − 10 months) following the removal of the external fixator. The perimeter, cross- sectional area, volume and the mean signal intensity was calculated from the obtained T1 weighted axial images. Values were compared with the contralateral tibia that acted as control. All cases that had bone transport increased the volume of the tibia from 15.3% up to 50.8%. The regenerated segment was noted to have expanded significantly (p< 0.0001) in all cases. Mean signal intensity in the regenerate decreased in seven cases significantly (p< 0.0001) suggesting increase content of unhydrated tissue such as bone and collagen. The cross-sectional surface of the transported segment was increased in all cases (p< 0.008). Finally in cases that underwent bone transport, the docking site was noted to be obstructed by unhydrated tissue. Contrary to previous claims, the post-distraction osteogenesis tibia is far from normal, consisting of areas with potentially different biomechanical properties. Recognition of these changes is essential not only for appropriate pre-operative counselling but also for considering treatment modalities in case of a fracture.


Orthopaedic Proceedings
Vol. 87-B, Issue SUPP_III | Pages 263 - 263
1 Sep 2005
Street J Lenehan B Buckley J Higgins T Mulcahy D
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Background: By the end of the current Bone and Joint Decade (2000–2010) the World Health Organisation predicts that 55% of post-menopausal women will have osteoporosis, as defined by fragility fracture and / or BMD. Volume aside, fragility fractures also represent a significant technical challenge in operative care. Current aggressive medical management is aimed to minimize the resource impact of this pandemic.

Study Design: This prospective study of 3000 consecutive fractures treated in a Level 1 trauma unit identified 977 fragility fractures requiring operative management, 803 of which were in patients over the age of 65 years. In every case the GP was informed of the diagnosis of osteoporosis and appropriate recommendations were made regarding medical management. We present the demographic features of this population and the resource impact of their management. We also examine the outcome of our efforts to improve care of the elderly with osteoporotic fractures, as all GP’s were contacted 6 months following discharge to determine the uptake of medical treatment as recommended.

Materials and Methods: Our computerized operative database was utilized to prospectively collect demographic and operative data on all 977 patients. All medical charts were examined to identify medications on admission, GP contact details and other relevant information. GP’s were contacted by telephone and post to determine patient 6-month mortality and the uptake in the use of recommended medication. Data represents the mean ± SD.

Results: Of the 803 patients over the age of 65 years, the average age was 80.5 ± 7.5 years, with a 75% female preponderance. 14% of these had had a previous wrist or vertebral insufficiency fracture, while 2.2% had a previous contralateral hip fracture. Hip fractures accounted for 70% (566 patients) of fragility fractures with 25% AMP, 24% Bipolar, 51% DHS. There were 121 wrist fractures. On admission 23% of hip fracture patients were resident in a Nursing Home. Despite the relatively large number with previous fracture (16.2%) only 3.4% were taking calcium / vitamin D supplementation while only 2.1% were on anti-resorptive therapy, eg a bisphosphonate. The median interval between admission and operation was 1 calendar day with a range of 1–10 days. 57% of all cases were performed outside of routine trauma lists. The average length of stay for this hip fracture population was 11.5 days with a further 16.5 days spent at a step down facility. Only 14.8% went directly home. Of 240 GP’s contacted, 74% replied resulting in complete follow-up data on 730 patients. The inpatient mortality rate was 5.8% while that at 6 months follow up was 19%. By this time 54% of hip fracture patients were living in Nursing Homes. The number of patients taking only calcium / vitamin D was 4%, a bisphosphonate alone 6%, while the use of both had risen dramatically to 16%.

Conclusions: To our knowledge this is the largest reported study documenting the epidemiology, demography and short-term follow-up of hip fractures in an elderly Irish population. Such data is essential to appropriately plan for the impending national health crisis consequent to the predicted dramatic rise in the elderly population with bone fragility. In a short time, we have achieved significant success in improving awareness and treatment of osteoporosis in the elderly following hip fracture.