Purpose

The treatment of C2 fractures with collar, halo or surgery can all be justified depending on the patient. In our unit, primary treatment is with a halo: in a previous study presented at BASS we found an 85% fusion rate. In a follow on study, we wished to assess the outcome in those patients who underwent surgical treatment.

To review the accuracy of our systematic process in preventing wrong level lumbar microdiscectomy.

X-ray is used to identify the correct level for the skin incision to be made, x-ray is again used if the surgeon is in doubt prior performing the flavotomy. Following a lumbar microdiscectomy a Watson Chane is inserted into the empty disc space and an intra-operative x-ray is taken to confirm the level the discectomy has occurred. Observers A and B independently reviewed intra-operative x-ray in patients undergoing lumbar microdiscectomies and correlated the accuracy of the x-ray in determining correct level surgery against the pre-operative MRI scan and the preposed level of surgery.

123 patients, 66 males and 57 females underwent 127 lumbar microdiscectomy procedures between 2007 and 2009. The levels where surgery occurred are;- L2/3 -1 patient, L3/4–8 patients, L4/5–53 patients and L5/S1-65 patients.

Kappa coefficient was used to determine inter-observer and Pearson Correlation coefficient was used to determine the X-ray and MRI relationship

Percentage of patients who required a pre-flavotomy x-ray level check are:- L2/3–100%, L3/4-63%, L4/5–45%, and L5/S1–40%. Pearson's correlation in confirming the level lumbar microdiscectomy was performed using final x-ray and the pre-operative MRI scan was 1. Kappa coefficient between observer A and B was 1.

This process of using intra-operative x-ray in determining the exact level where lumbar microdiscectomy was performed is 100% accurate. This is our standard process in preventing wrong level surgery for lumbar microdiscectomy.

The Royal Liverpool and Broadgreen University Hospital, Liverpool, UK

Plasmacytoma is the localised form of multiple myeloma, which can affect any part of the body including the axial skeleton (Kelly et al, 2006; Ampil et al, 1995). These myelomas/plasmacytomas arise from one malignant clone of cells, which secrete the same type of immunoglobulin. Where the clone of cells remains localised, it is known as plasmacytoma, but when there is spread of the malignancy to multiple bones and marrow, it is known as multiple myeloma (Boccadoro and Pileri, 1995).

We present a case of solitary sacral bone plasmacytoma (SBP), in a seventy year old man which presented as low back pain, following a fall. He was neurologically intact, and had no sphincteric incontinence, but MRI revealed a large expansile lesion in S1, which caused severe spinal stenosis, involving the left L5 exiting foramen, with an irregular area of low signal posteriorly. Bone scan showed increased tracer uptake in L5 and a mixed hot/photopaenic appearance in the mid-sacral region indicating tumor involvement. Myeloma screen confirmed that the serum IgA was high, with positive kappa monoclonal band, positive Bence Jones Protein (BJP), normal IgM and IgG, and normal calcium profile. CT-guided biopsy revealed sheets of mature plasma cells, consistent with the diagnosis. Fine needle aspiration biopsy of an enlarged groin lymph node revealed neoplastic infiltration, consistent with myeloma. Skeletal survey and CT chest/abdomen/pelvis (CAP) were not contributory. The patient had six courses of radiotherapy and improved remarkably, and is being considered for chemotherapy as well as follow up in the out-patients' department.

Introduction: The management atlanto-axial fractures, particularly those of the odontoid peg, remains controversial. We managed patients with C1/C2 fractures non-operatively in rigid immobilization until CT-scanning confirmed bony union, rather than for the standard 3-month period. We examined whether this improved outcomes and reduced the need for surgery.

Method: All patients admitted to our unit with atlanto-axial fractures between 2001–2007 were retrospectively analyzed. All fractures had the ‘intention-to-treat’ conservatively in either halothoracic vest (85%) or Aspen collar (15%). Rigid immobilization was maintained until CT-scanning demonstrated bony fusion. Functional stability was subsequently assessed with flexion-extension radiographs after removal of rigid immobilization.

Results: Twenty-seven patients were studied. Nineteen had odontoid peg fractures (10 type II; 9 type III). The remainder consisted of 3 Hangman’s, 3 lateral mass and 2 atlas ring fractures. 83% of patients progressed to union at an average of 13.2 weeks (range 5–22). Six complications related to halo immobilization were observed (three skull perforations/pin-site infections). All of these patients progressed to union non-operatively.

Failure of non-operative management was deemed as non-union or poor patient tolerance of halo, and occurred in 4 patients (17%). All four had type II odontoid peg fractures, and had transarticular screw fixation. One postoperative complication of screw fracture was recorded.

Conclusion: Non-union rates of conservatively managed atlanto-axial fractures with standard 3-month rigid immobilization have been reported as high as 35%. In our series, CT-imaging to confirm bony union prior to removal of the rigid immobilization (prolonging immobilization where necessary) significantly lowered the rate of non-union and therefore the need for subsequent surgery.

Ethics approval: None Audit

Interest Statement: None

Background: To assess the accuracy of pedicle instrumentation placement using an image guidance system ( Medi Vision) in a pig cadaveric model.

Methods: A 4mm diameter (10cm long) screw was inserted transversely into the spinous process of a pig cadaver percutaneously using fluoroscopic guidance. The dynamic reference base (DRB) of the image guidance system was then attached to the screw. Using the navigation system both pedicles at each level were identified and 3.2mm guide wires inserted percutaneously. This process was performed for each level from D7 to L4. Actual wire placement was recorded using standard anteroposterior and lateral fluoroscopic images. Virtual trajectories generated by the image guidance system were recorded on the guidance system database. Accuracy of wire placement was then evaluated in an automated way by linear correlation between corresponding images.

Results: 20 pedicles were instrumented at 10 levels from D7 to L4. Mean estimate of accuracy for dorsal levels AP and lateral (mm). Mean = 1.452mm, standard deviation 1.57mm. Mean for lumber levels= 1.047mm, standard deviation 1.187mm

Conclusion: Lumbar pedicle instrumentation showed more accuracy when compared to dorsal pedicle instrumentation. The error of navigation that was accommodated by the image guidance system was 2mm.

There was correlation between fluoroscopic copies and virtual trajectories.

This image guidance system may not only aid in the placement of pedicle instrumentation but also assist the senior surgeon in trainee supervision.