Different methods of lateral mass(LM) screw placement in the cervical spine have been described. In the axial plane, 30 degrees is the recommended angle to avoid neurovascular injury. The estimation of this angle remains arbitrary and operator dependant.

To assess how accurately the lateral trajectory angle (LTA) for cervical LM screws is achieved by visual estimation amongst experienced spinal surgeons.

A sawbone model of cervical spine with simulated lordosis was used. Five spinal consultants and five senior spinal fellows were asked to insert 1.6 mm K wires into lateral masses of C3 to C6 bilaterally to simulate screws. The LTA in transverse plane was measured using a customised protractor. Basic statistical analyses of all the data were obtained. Using all the angles derived, a virtual screw trajectory was drawn in the lateral plane, on a normal axial Computerised Tomography scan of cervical spine of an anonymous patient using PACS system.

The overall mean LTA for the group was 25.15 degrees, that of the fellows 24.4 and consultants 26.2 degrees. Mean deviation from 30 degrees for fellows was 5.2 and 6.4 degrees for consultants. Overall standard deviation was 4.78, for fellows and consultants it was 3.3 and 5.8 respectively. Two episodes of vertebral artery injury occurred at 15 and 16 degrees with simulated angles on CT.

A moderate variability in visual estimation of the trajectory angle exists even amongst experienced surgeons during insertion of cervical LM screws. An anatomical landmark would be useful to improve the reliability of the procedure.

The aim of this study was to prospectively assess the outcome of patients with metastatic spinal disease who underwent minimally invasive fixation of the spine for intractable pain or spinal instability.

This is a prospective audit of patients with metastatic spinal cord disease who have undergone minimally invasive fixation of the spine from August 2009 until the present date. This was assessed by pre and post-operative Oswestry Disability Index (ODI), EQ5D and Tokuhashi scores. Intra- and post-operative complications, time to theatre, length of inpatient stay, analgesia requirements, mobility, chest drain requirement and post-operative HDU and ITU stays were also recorded.

So far, 10 patients have met the criteria. There were no intra-operative complications. Post-operatively, there were no complications, chest drains, increase in analgesia or stay on the HDU or ITU. All patients showed an improvement in mobility. The mean post-operative day of mobilisation was 2 days, post-operative days until discharge 5.3 days and length of inpatient stay was shorter than traditional surgery. Blood loss was minimum except one patient with metastatic renal cell carcinoma who needed transfusion intraoperatively.

ODI, VAS and EQ-5D scores were calculated and were significantly improved compared to preoperatively.

This novel approach to management of metastatic spinal disease has resulted in improved mobility, short inpatient stays without the need for chest drains, HDU or ITU and an improved the quality of life in pallliative patients. This is a completely new strategy to treat the pain in these patients without the usual associated risks of surgery and has major advantages over traditional surgical techniques which may preclude this group of patients having any surgical stabilisation procedure at all

Introduction: Patella maltracking is dependent on multifactorial reasons. We have been able to identify one of major and important factor being the rotational alignment of the femoral component. The other subtle variable factors that have a cumulative effect on the tracking of the patella is recognized, which is not the major thrust this study.

Methods and Materials: This is a prospective study on a total of 200 TKR. The first subset of 100 done by the same surgeon and same type of prosthesis and the same sequence of all femoral cuts followed by the tibial cut.

Thus, the rotation of the femoral component was referenced from the posterior condyles.

The second subset of 100 cases, the distal femoral cut was followed by the tibial resection. The susequent femoral resection was referenced from the tibial cut. Thus the rotation of the femoral component was dependent on the tibial axis, and not on the posterior femoral condyles, which in deficient condyles can lead to a significant rotational error.

Conclusion: In the first subset the incidence of lateral release were 3% and 10% asymptomatic patellar tilt.

In the second subset, where the femoral rotation was referenced from the tibial axis, excluding the severe valgus knees, the incidence of lateral release was 0% with asymptomatic patellar tilt of 6%. since all other factors were unchanged i.e. patella replacement, rotation of the tibial prosthesis, same prosthesis, the single variable factor being the femoral rotation leads us to conclude that femoral rotation is a major in appropriate patellar tracking. As a corollary ‘Patellar tracking is the index of orientation, sizing of all components of the prosthesis and soft tissue balance’.