Introduction

A recent paper suggested implanting an uncemented acetabular shell which is 6mm or greater than the native femoral head in total hip arthroplasty (THA) significantly increased the risk of postoperative pain. We retrospectively analyzed 265 Delta ceramic-on-ceramic (DCoC) THA comparing the native femoral head size to the implanted shell and reviewing if the patient suffered with post-operative pain (POP).

Background

Magnetic resonance arthrography is the current method of choice for investigating patients with a clinical diagnosis of femoroacetabular impingement prior to performing hip arthroscopy. The aim of our study was to assess the efficacy of this investigation by comparing the findings of MR arthrogram with those found at arthroscopy, with reference to labral tears and chondral damage.

Background

The optimal management of idiopathic clubfoot has changed over three decades. Recently there has been an enthusiastic embracing of the Ponseti technique. The purpose of this 14-year comparative prospective longitudinal study was to directly assess the differences in results between these two treatment methods.

Background

Femoroacetabular impingement (FAI) may be a predisposing factor in progression of osteoarthritis. The use of hip arthroscopy is in its infancy with very few studies currently reported. Early reports show favourable results for treatment of young patients with FAI. This prospective study over a larger age spectrum represents a significant addition to this expanding field of minimally invasive surgery.

Background

Successful use of bioabsorbable anchors for capsulolabral and rotator cuff repair is well documented. The bioknotless anchor (DePuy mitek) has demonstrated reliable fixation of these pathologies. However, this poly (L-lactide) polymer has recently demonstrated some similar complications to those documented for the earlier polyglycolic acid implants; namely synovitis and chondral damage with osteolysis. We report three cases with osteolysis and chondral damage associated with bioknotless anchors.

Purpose of study

The results clinically & statistically of a 14 year longitudinal study comparing the traditional ‘stretch & strap’ method (1994-2002) with the Ponseti technique (2002-2008)

In the current climate of increasing financial pressures and reducing bed numbers, a predictor of length of stay (LOS) may have a bearing on hospital finances. Independent sector treatment centres may also skew the ASA grade and co-morbidity of the patient group treated in a hospital setting. We performed a study of 100 consecutive patients undergoing Total hip or knee arthroplasty between April and September 2006.

Median age was 71 years (35 – 88) with 75% of patients having significant (cardiac, renal or respiratory) pre-existing medical conditions (24% with 3 or more conditions). Average ASA grade was 2 (15% grade 3) and average BMI was 30. A significant reduction in LOS from 8.47 to 5.87 days was seen in under 70 year olds when compared with those over 70 years (p = 0.0004), having 3 or more co-morbidities (compared with 2 or less) increased average LOS from 6.61 days to 9.3 days (p = 0.002), ASA grade of 3 increased LOS to 9.56 days from 6.27 and 6.87 for grade 1 and 2 respectively (p = 0.014) and living alone (compared with cohabiting) increased LOS from 6.55 days to 9.19 days (p = 0.0017). However no statistical significance was seen for BMI with an average of 7.19 days for < 30 and 7.37 days for patients with BMI of 30 or above (p = 0.82)

Regardless of this patient group being elderly and obese with significant co-morbidity, an acceptable outcome was seen, with 70% of patients discharged within 7 days and only 4% staying > 14 days. Although BMI did not predict outcome, number of co-morbidities, ASA, age greater than 70 years and living alone all demonstrated a significant increase in LOS. Increased resources in this at risk group within a pre-admission setting could reduce length of hospital stay.

Background: The use of sacro-iliac screws to restore the stability of posterior pelvic ring dissociations has become a standard technique. Several methods are described including fluoroscopy, CT and computer assisted techniques. Fluoroscopically assisted insertion is the standard technique. Multiple exposures of ionising radiation permit acquisition of a target in sequential planes, requiring a process of interpolation for 3-D localisation. A computer assisted technique facilitates the simultaneous visualisation of multiple planes following a single image intensifier acquisition and registration process in each plane. The purpose of this study is to demonstrate the accuracy of a computer assisted surgery technique and quantify the predicted reduction in radiation exposure.

Methods: 10 embalmed human cadavers were used. In each specimen, a sacro-iliac screw was simulated by passing a 5mm reamer over a 3.2mm guide wire. The index track was formed with a closely sheathed 4.8mm drill and was inserted with the standard fluoroscopically assisted technique in the left hemipelvis and a computer assisted technique(Vector Vision trauma) on the right. Registration of the system is achieved by the placement of infra red reflective arrays on all tracked objects. These include the right and left hemi-pelvis, the fluoroscope, the drill guide and the driver unit. The system is an open platform which registers arrays of known geometry whilst permitting the registration of instruments by means of an instrument calibration matrix. The pelvic T and Y pattern fiducials are fixed rigidly to inter-table threaded pins at the level of the gluteal tuberosities. The standard acquisition projections are inlet and outlet views for both techniques with the addition of lateral projections although the latter were not directly used for navigation. Postoperative CT scans demonstrate the actual tracks and analysis is facilitated by means of a digital mapping technique.

Results: The accuracy of the fluoroscopically assisted and computer assisted techniques is identical. The procedure time was significantly longer for the computer assisted technique although most of the additional time was accounted for by the “line of sight” registration process. There was a reduction in both the total screening time and the measured radiation dose in the case of the computer assisted technique although this did not reach statistical significance as the sample size is relatively small.

Conclusions: The navigation of sacro-iliac screw tracks by means of both fluoroscopically assisted and computer assisted techniques proves equally accurate in a human cadaveric model.