Infection in arthroplasty surgery is a major complication leading long antibiotic courses and frequently requiring repeated operations to eradicate or suppress. Therefore in the situation of revision surgery on prosthesis that are possibly already infected a clear identification of possible infection is required. Previously frozen section samples have been used in Derriford Hospital in conjunction with clinical presentation and other investigations to aid in diagnosis and tailor management, however recent studies have suggested that this may not be as effective as previously thought. Kanner et al. (2008) suggested a sensitivity of 29% and positive predictive value of 40%.

This retrospective audit reviewed the cases between March 2007 and May 2012, identifying 220 cases of revision surgery where infection was suspected and frozen sections analysis was performed. Results where then compared to paraffin and cultured samples if taken. A notes review was performed to demonstrate if the operative technique (single or two stage) was in line with local guidelines for the results of the frozen section. Long term survival (longest follow up of 7 years) was assessed by need for revision surgery.

The Columbus® knee system was designed as a standard knee implant that allows high flexion without the need for additional bone resection. The aim of this retrospective study was to investigate the correlation between the maximum flexion achieved at five years and the slope of the tibial component. The hypothesis was that increased slope would give increased flexion.

The study design was a retrospective cohort study at a single centre. The inclusion criterion was having had a navigated cemented Columbus primary TKA implanted between March 2005 and December 2006 using the image free OrthoPilot® navigation system (Aesculap, Tuttlingen, Germany) in our institution. Follow-up had been carried out at review clinics by an independent arthroplasty team. Patient-related data had been recorded either in case notes, the departmental proprietary database or as radiographic images. In addition to demographics, five-year follow-up range of motion (ROM) was collected. All available radiographs on the national Picture Archiving and Communication System (Eastman Kodak Company, 10.1_SP1, 2006), whether taken at our institution or at the patient's local hospital, were analysed by a trainee orthopaedic surgeon (NCS) who was independent of the patients' care. Component position according to the Knee Society TKA scoring system was determined from the five-year review lateral x-ray. The tibial slope was calculated as 90° minus the angle of the tibial component so giving a posterior slope as a positive number and an anterior slope as a negative number. The correlation between maximum flexion angle and tibial slope was calculated. Further to this a subgroup of only CR prostheses and patients with BMI <35 were analysed for a relationship. The tibial slope of the group of patients having 90° or less of flexion (poor flexion) was compared to those having 110° or more (good flexion) using a t-test, as was the flexion of the those with BMI <30 to those with BMI > 35.

A total of 219 knees in 205 patients were identified. 123 had five-year radiograph and maximum flexion measurement available. Cohort demographics were mean age 68(8.6), mean BMI 32.0(5.9) and mean maximum flexion at five years of 101°(11°). The tibial slope angle showed variation around the mean of 2°(2.8°). There was no correlation between tibial slope and maximum flexion for either that whole cohort (r=-0.051, p=0.572, Figure 1b) or the subgroup of CR and BMI <35 patients (n=78, r = −0.089, p=0.438). The mean tibial slope of those patients having poor flexion was 2° (SD2.6°) and this was not significantly different to the mean for those with good flexion, 3° (SD3.1°) p=0.614. The mean flexion of those with BMI <30 was 100° (SD8.7°) and this was not significantly different to those with BMI >35, mean 101° (SD11.4°).

This study did not find any correlation between the tibial slope and maximum flexion angle in 123 TKAs at five year follow up. Further studies with a more accurate measurement of tibial slope should be carried out to confirm whether a relationship exists in the clinical setting.

Recurrent patella dislocation is a well-recognized complication after primary dislocation of the patellofemoral joint. We propose that acute surgical management of the injury minimizes this risk.

Between February 2006 and August 2010 47 patients (49 knees) with a mean age of 17.9 (range 12–31) at the time of surgery who sustained a patellofemoral joint dislocation for the first time were treated with an acute repair of the medial patellofemoral ligament.

Patients presenting to our fracture clinic following a primary lateral dislocation of the patella were investigated with an MRI scan and with consent, proceeded to have an examination under anaesthesia and arthroscopy of the injured knee. An easily dislocatable patella in the presence of a confirmed medial patellofemoral ligament rupture was the indication for open repair.

All patients treated surgically were followed up for a period of 24–72 months where the primary outcome measure was further dislocation. An evaluation of symptoms, functional recovery, restoration of range of movement and patient satisfaction was made supported by the Lysholm knee score.

Our results confirm that acute repair of the medial patella femoral ligament in selected patients reduces the risk of further dislocations and results in a overall good functional outcome and patient satisfaction with minimal complications.