Background

Bone preservation is desired for future revision in any knee arthroplasty. There is no study comparing the difference in the amount of bone resection when soft tissue balance is performed with or without computer navigation.

To determine the effect on bony cuts when soft tissue balance is performed with or without use of computer software by standard manual technique in total knee arthroplasty.

One hundred patients aged 50 to 88 years underwent navigated TKR for primary osteoarthritis. In group A, 50 patients had both soft tissue release and bone cuts done using computer-assisted navigation. In group B, 50 patients had soft tissue release by standard manual technique first and then bone cuts were guided by computer-assisted navigation.

In group A the mean medial tibial resection was 5 ± 2.3 mm and lateral was 8 ± 1 mm compared to 5 ± 2 mm (P = 0.100) and 8 ± 1 mm respectively in group B (P = 0.860). In group A the mean medial femoral bone cut was 9 ± 2.9 mm and lateral was 8 ± 2 mm as compared to 9.5 ± 2.9 mm (P = 0.316) and 10 ± 2.2 mm respectively in group B (P = 0.001). Average prosthesis size was 6 (range 3 to 8) in group A as compared to size 5 (range 2 to 7) in group B. Average navigation time in group A was 102 minutes (range 45 to 172) and in group B was 83 minutes (range 42 to 165, P = 0.031).

Our results show that performing soft tissue release and bone cuts using computer- assisted navigation is more bone conserving as compared to manual soft tissue release and bone cuts using computer navigation for TKR, thus preserving bone for possible future revision surgery.

Background of Study

Identification of the exact make and model of an orthopaedic implant prior to a revision surgery can be challenging depending upon the surgeon's experience and available knowledge base about the available implants. The current identification procedure is manual and time consuming as the surgeon may have to do a comprehensive search within an online database of radiographs of an implant to make a visual match. There is further time lapse in contacting that particular implant manufacturer to confirm the make and model of the implant and then order the whole inventory for the revision surgery. This leads to delay in treatment thus requiring extra hospital bed occupancy.

Introduction

Increased accuracy of pre-operative imaging in patient-specific instrumentation (PSI) can result in longer-term savings, and reduced accumulated dose of radiation by eliminating the need for post-operative imaging or revision surgery. The benefits and drawbacks of CT vs MRI for use in PSI is a source of ongoing debate. This study reviews all currently available evidence regarding accuracy of CT vs MRI for pre-operative imaging in PSI.

We reviewed the outcome of 69 uncemented, custom-made, distal femoral endoprosthetic replacements performed in 69 patients between 1994 and 2006. There were 31 women and 38 men with a mean age at implantation of 16.5 years (5 to 37). All procedures were performed for primary malignant bone tumours of the distal femur. At a mean follow-up of 124.2 months (4 to 212), 53 patients were alive, with one patient lost to follow-up. All nine implants (13.0%) were revised due to aseptic loosening at a mean of 52 months (8 to 91); three implants (4.3%) were revised due to fracture of the shaft of the prosthesis and three patients (4.3%) had a peri-prosthetic fracture. Bone remodelling associated with periosteal cortical thinning adjacent to the uncemented intramedullary stem was seen in 24 patients but this did not predispose to failure. All aseptically loose implants in this series were diagnosed to be loose within the first five years.

The results from this study suggest that custom-made uncemented distal femur replacements have a higher rate of aseptic loosening compared to published results for this design when used with cemented fixation. Loosening of uncemented replacements occurs early indicating that initial fixation of the implant is crucial.

Cite this article: Bone Joint J 2014;96-B:263–9.

INTRODUCTION

Establishing a full-thickness cartilage in the lateral compartment and functionally intact ACL is vital before proceeding with unicompartmental knee replacement (UKR). The aim of this study is to assess whether MRI is a useful adjunct in predicting suitability for UKR, as compared to standard and stress radiographs.

Background: Traditionally, lumbar discectomy is performed under general anaesthesia because of ability to perform operations of long duration in prone position with a secure airway. Some recent reports suggest better outcomes with regional anaesthesia.

Aim: The aim of this study was to compare the intra-operative and short-term post-operative outcome variables in patients undergoing primary single-level lumbar discectomy with epidural and general anaesthesia.

Methods: This was a prospective randomized trial involving sixty patients over a two-year period in a tertiary hospital in India. Patients were allocated into two groups: Group A (n=30) patients received general anaesthesia and Group B (n=30) patients received epidural anaesthesia. Baseline and intra-operative haemodynamic parameters, surgical duration, surgical onset time, intra-operative blood loss, cost incurred by patient, nausea and vomiting and post-operative pain score were also recorded.

Results: The groups were comparable for demographic data and baseline hemodynamic observations. Patients in the epidural anaesthesia group had significantly lower blood loss (p< 0.001), lower peak pain scores (p< 0.001), lesser surgical time (p< 0.001),and significantly reduced post-operative nausea and vomiting (p< 0.01) as compared to the general anaesthesia group. The cost incurred for epidural anaesthesia was two third of that incurred in general anaesthesia (p< 0.001). Epidural group had significantly more surgical onset time (p< 0.001)

Conclusion: Lumbar discectomy can be safely performed using epidural anaesthesia. The intra-operative blood loss, surgical duration, cost incurred by the patient, postoperative nausea, vomiting and pain are significantly reduced in patients receiving epidural anaesthesia, thereby leading to a significantly higher patient satisfaction. In the present climate of NHS, where any initiative to cut down the cost of resources consumed is welcomed as long as the patient safety is not compromised, epidural anaesthetic may provide an effective alternative to general anaesthetic for lumbar discectomy.