Revision knee arthroplasty is a complex procedure with the number and cost of knee revision procedures performed per year expected to rise. Few studies have examined adverse events following revision arthroplasty.

The objective of this study was to determine rates of serious adverse events in patients undergoing revision knee arthroplasty with consideration of the indication for revision (urgent versus elective indications) and to compare these with primary arthroplasty and re-revision arthroplasty.

Patients undergoing primary knee arthroplasty were identified in the UK Hospital Episode Statistics. Subsequent revision and re-revision arthroplasty procedures in the same patients and same knee were identified. The primary outcome was 90-day mortality and a logistic regression model was used to investigate factors associated with 90-day mortality and secondary adverse outcomes including infection (undergoing surgery), pulmonary embolism, myocardial infarction, stroke. Urgent indications for revision arthroplasty were defined as infection or fracture, and all other indications were included in the elective indications cohort.

939,021 primary knee arthroplasty cases were included of which 40,854 underwent subsequent revision arthroplasty, and 9,100 underwent re-revision arthroplasty. Revision surgery for elective indications was associated with a 90-day rate of mortality of 0.44% (135/30,826; 95% CI 0.37-0.52) which was comparable to primary knee arthroplasty (0.46%; 4,292/939,021; 95% CI 0.44-0.47). Revision arthroplasty for infection, however, was associated with a much higher mortality of 2.04% (184/9037; 95% CI 1.75-2.35; odds ratio [OR] 3.54; 95% CI 2.81-4.46), as was revision for periprosthetic fracture at 5.25% (52/991; 95% CI 3.94-6.82; OR 6.23; 95% CI 4.39-8.85). Higher rates of pulmonary embolism, myocardial infarction, and stroke were also observed in the infection and fracture cohort.

These findings highlight the burden of complications associated with revision knee arthroplasty. They will inform shared decision-making for patients considering revision knee arthroplasty for elective indications. Patients presenting with infection of a knee arthroplasty or a periprosthetic fracture are at very high risk of adverse events. It is important that acute hospital services and tertiary referral centres caring for these patients are appropriately supported to ensure appropriate urgency and an anticipation for increased care requirements.

Recent National Institute for Health and Care Excellence (NICE) guidance has advised against the continued use of the Thompson implant when performing hip hemiarthroplasty and recommended surgeons consider using the anterolateral surgical approach over a posterior approach.

Our objective was to review outcomes from a consecutive series of Thompson hip hemiarthroplasty procedures performed in our unit and to identify any factors predicting the risk of complications.

807 Thompson hip hemiarthroplasty cases performed between April 2008 and November 2013 were reviewed. 721 (89.3%) were cemented and 86 (10.7%) uncemented. 575 (71.3%) were performed in female patients. The anterolateral approach was performed in 753 (93.3%) and the posterior approach with enhanced soft tissue repair in 54 (6.7%).

Overall, there were 23 dislocations (2.9%). Dislocation following the posterior approach occurred in 13.0% (7 of 54) in comparison to 2.1% (16 of 753) with the anterolateral approach (odds ratio (OR) 8.5 (95% CI 2.8 to 26.3) p < 0.001). Surgeon grade and patient history of cognitive impairment did not have a significant impact on dislocation rate.

Patients were discharged home in 459 cases (56.9%), to a care home or other hospital in 273 cases (33.8%). 51.8% (338 of 653) returned home within 30 days. 75 died during their admission (9.3%). 30-day mortality was 7.1% and 1-year mortality was 16.6%.

Intraoperative fracture occurred in 15 cases (1.9%) of which 14 were cemented. Superficial or deep infection occurred in 33 cases (4.1%).

We recommend against the continued use of the posterior approach in hip hemiarthroplasty, as enhanced soft tissue repair did not reduce dislocation rates to an acceptable level. Our findings, however, demonstrate satisfactory results for patients treated with the Thompson hip hemiarthroplasty performed through an anterolateral approach. We suggest that the continued use of the Thompson implant in a carefully selected patient cohort is justifiable.

When performing total knee replacement (TKR), surgeons must select a size of tibial component tray that most closely matches the anatomy of the proximal tibia. As implants are available in a limited range of sizes, it may be necessary to slightly under or oversize the component. There are concerns overhang could lead to pain from irritation of soft tissues, and underhang could lead to subsidence and failure.

154 TKRs at 1- or 5-year follow up were reviewed prospectively. Oxford Knee Score (OKS), WOMAC and SF-12 was recorded along with pain scores. Scaled radiographs were reviewed and grouped into perfect sizing (78 TKRs, 50.6%), underhang in isolation (48 TKRs, 31.1%), minor overhang 1–3 mm (10 TKRs, 6.49%) or major overhang >3 mm (18 TKRs, 11.7%).

There was no significant difference in the SF-12 (p=0.356), post-operative OKS (p=0.401) or WOMAC (p=0.466) score. For the OKS, there was no difference for the scores collected at 1 year (p=0.176) or at 5 years (p=0.883).

Pre-operative OKS was well matched between the groups (p=0.152). There was no significant difference in the improvement in OKS from pre-operative scores (p=0.662). There was no significant difference in either the OKS or WOMAC pain scores (p=0.237 and 0.542 respectively).

There was no significant association of medial overhang with?medial knee pain (p=1.000) or lateral overhang with lateral knee pain (p=0.569) when compared to the group of patients with a well sized tibial component.

Our results suggest that tibial component overhang or underhang has no detrimental affect on outcome or pain scores. Surgeons should continue to select the tibial component that most closely fits the rim of the proximal tibia while accepting slight overhang if necessary due to the potential longer-term complications of subsidence and premature failure with an undersized tibial tray.

Staged bilateral total knee arthroplasty is performed increasingly frequently but no data has been published comparing the specific outcome for the first knee replacement to that of the second.

Pre-operative and post-operative Oxford Knee Scores (/ 48) were reviewed for each knee in a series of 91 patients undergoing staged bilateral total knee arthroplasty over a 5-year period.

Pre-operative scores for the first total knee arthroplasty were significantly worse with a mean of 14.9 in comparison to 17.0 for the second knee (P=0.0083). While there was no significant difference between the mean post-operative scores for the first knee (37.4) and the second knee (36.6) (P=0.195), the mean improvement was significantly less for the second knee (22.6 points versus 19.6 points) (P=0.0045).

Our results demonstrate that in patients undergoing staged bilateral knee arthroplasty, the second knee replacement is commonly performed at a lower threshold and functional improvement is less than for the first knee. This data will be important to inform the expectations of patients considering proceeding to bilateral knee arthroplasty after previously having undergone a primary total knee replacement.

The long-term clinical and radiological results of 63 uncemented Low Contact Stress (LCS) total knee replacements in 47 patients with rheumatoid arthritis were reviewed. The average age at the time of surgery was 69 years (53–81). At a mean follow up of 22 years (20–25), 12 patients (17 knees) were alive, 27 (36 knees) had died, and 8 patients (10 knees) were lost to follow-up.

Revision was necessary in seven patients (7 knees) (11.1%) at mean 12.1 years following surgery. Four revisions were performed due to meniscal bearing wear, two for collapse of the tibial component, and one for aseptic loosening. Evidence of post-operative infection occurred in two knees (3.2%) within 6 weeks of surgery but resolved with antibiotics. Within the group of deceased patients, five had undergone revision (included in total revisions) but otherwise the primary implant remained in vivo.

For all living patients, the mean Oxford Knee Score (/48) was 30.2 (16–41) at latest follow up at mean 19.5 years (15–24.7) following surgery. Mean active flexion was 105 degrees (90–150) at this time point.

Our recorded survival rate of the uncemented LCS total knee replacements in patients with rheumatoid arthritis was therefore 88.9% at mean 22 years, or worst-case survival of 73.0% if patients lost to follow-up were considered failures. From a review of the literature and as far as we are aware, this study represents the longest follow up of any uncemented knee arthroplasty performed in a cohort of patients with rheumatoid arthritis.