Aims

To explore the clinical relevance of joint space width (JSW) narrowing on standardized-flexion (SF) radiographs in the assessment of cartilage degeneration in specific subregions seen on MRI sequences in knee osteoarthritis (OA) with neutral, valgus, and varus alignments, and potential planning of partial knee arthroplasty.

We have assessed the bone cuts achieved at surgery compared to the planned cuts produced during computer assisted surgery (CAS) using a CT free navigation system. In addition, two groups of matched patients were compared to assess the post-operative mechanical alignment achieved: 14 patients received a LCS total knee replacement (TKR) using the VectorVision module and 14 received a TKR using a conventional method of extramedullary alignment jigs The deviation in each plane (valgus-varus, flexion-extension and proximal-distal) was calculated.

For the tibia the mean deviation in the coronal plane was 0.21 degrees of Varus (SD = 1.37) and in the sagittal plane was 1.29 degrees of flexion (SD = 3.73) and 0.24 mm of resection distal to the anticipated cut (SD = 2.14). For the femur the mean deviation in the coronal plane was 0.88 degrees (SD = 2.2) of valgus and in the sagittal plane the mean deviation was 0.3 degrees (SD = 2.91) of extension. In the transverse plane there was a mean deviation of 0.07 degrees (SD = 1.57) of external rotation. There was mean deviation of 2.33 mm of proximal resection (SD = 2.9) and 1.05 mm of anterior shift (SD = 2.81).

On comparing the two groups, no statistically significant differences were found for the angles between the femoral component and the femoral mechanical axis, the tibial component and the tibial mechanical axis, the femoral and tibial mechanical axis and the femoral and tibial anatomical axis.

We have demonstrated variation in the true bone cuts obtained using computer assisted surgery from those suggested by the software and have not demonstrated significant improvement in post-operative alignment. Justification for the extra cost, time and morbidity associated with this technology must be provided in the form of improved clinical outcomes in the future.

To assess the outcome and implant removal rate following surgical stabilisation of patella fracture.

Sixty-seven patients who underwent surgical stabilisation of patella fracture between January 1999 and December 2004 were retrospectively reviewed to determine the adequacy of fracture stabilisation, fracture union and implant removal rate.

Forty-three were men and 24 were women with a mean age of 49 years (ranged 14–90 years). Table below demonstrates the injury, fracture patterns and fixation methods. There were 3 open fractures and associated injuries were noted in 22 patients. All fractures united even though the fixation was inadequate in 46 patients. Two superficial infections responded to oral antibiotics. One patient had revision surgery at 6 weeks. Twenty-two patients required implant removal between 2 and 20 months (average 11 months) for implant related symptoms. Of the 22 (32.8%) patients requiring implant removal, 16/40 (40%) were less than 60 years and 6/27 (22.2%) were over 60 years. Mean follow up in asymptomatic patients was 8 months (3 to 18 months) and in patients with implant related problems was 17 months (10 to 36 months). Four patients were lost to follow up.

Surgical stabilisation by current techniques demonstrated satisfactory fracture union. However, one in three required second surgery for implant related symptoms. In the under 60 years group, the implant removal rate increased to 40%. Newer techniques to avoid skin irritation need to be considered.

We describe the association between immediate postoperative radiological appearances and early aseptic failure of THA having compensated for the methodological flaws in previous similar studies. 63 hips were entered into the aseptic failure group and 138 into the control group. Alignment of the femoral stem was not associated with failure (p=0.283). Thickness of the cement mantle was associated with failure in Gruen zones 6 (p=0.040) and 7 (p=0.003). A significant association for the presence of radiolucent lines was found for Gruen zones 3 (p=0.0001) and 5 (p=0.0001). Grade of cementation was associated with failure for Barrack grades C (p=0.001) and D (p=0.001). This study has demonstrated that easily applied radiological criteria can be used to identify at risk THAs from the immediate post-operative AP radiograph.

The results of hip injections for 63 patients with hip pain are presented. Injection of 80mg of methylprednisolone and bupivacaine by an anterior approach was performed with x-ray screening. Patients were noted as having either a normal x-ray (10), mild osteoarthritis (21), moderate osteoarthritis (13) and severe osteoarthritis (19), those in the severe group were generally unfit for hip surgery. Outcome was judged by an Oxford hip score, which was calculated pre-injection, at one month, and at three months. At three months all with a normal x-ray were improved, 19 with mild changes were improved 2 deteriorated, 9 with moderate changes improved, 2 stayed the same, 2 deteriorated and 13 with severe changes were improved, 4 deteriorated and 2 were unchanged. Improvements were with pain scores not function. Of those improved all thought the procedure worthwhile. Two patients described numbness and weakness at the anterior thigh area, which recovered quickly. We feel that this is a useful technique to give symptomatic relief in-patients not suitable for hip replacement.