Aims. It is common practice for patients to have postoperative blood tests after total joint replacement (TJR). However, there have been significant improvements in perioperative care with arthroplasty surgery, and a drive to reduce the length of stay (LOS) and move towards day-case TJR. We should reconsider whether this intervention is necessary for all patients. Methods. This retrospective study included all patients who underwent a primary unilateral TJR at a single tertiary arthroplasty centre during a one-year period. Electronic medical records of 1,402 patients were reviewed for patient demographics, LOS, and American Society of Anesthesiologists (ASA) grade. Blood tests were examined to investigate the incidence of postoperative anaemia, electrolyte abnormalities, and incidence of acute kidney injury (AKI). Results. For total knee arthroplasties, preoperative (R = −0.22) and postoperative haemoglobin (R = 0.2) levels were both negatively correlated with LOS (p < 0.001). For all patients who had undergone a TJR, 19 patients (0.014%) required a blood transfusion postoperatively due to symptomatic anaemia. Risk factors identified were age, preoperative anaemia, and long-term aspirin use. Significant abnormal sodium levels were found in123 patients (8.7%). However, only 36 patients (2.6%) required intervening treatment. Risk factors identified were age, preoperative abnormal sodium level, and long-term use of non-steroidal anti-inflammatory drugs, angiotensin receptor blockers, and corticosteroids. Similarly, abnormal potassium levels were evident in 53 patients (3.8%), and only 18 patients (1.3%) required intervening treatment. Risk factors identified were preoperative abnormal potassium level, and long-term use of angiotensin-converting enzyme inhibitors and diuretics. The incidence of AKI was 4.4% (61 patients). Risk factors identified were age, increased ASA grade, preoperative abnormal sodium, and creatinine level. Conclusion. Routine blood tests after primary TJR is unnecessary for most patients. Blood tests should only be performed on those with identifiable risk factors such as preoperative anaemia and electrolyte abnormalities, haematological conditions, long-term aspirin use, and electrolyte-altering medications. Cite this article: Bone Jt Open 2023;4(5):357–362

Aims

The present study aimed to investigate whether patients with inflammatory bowel disease (IBD) undergoing joint arthroplasty have a higher incidence of adverse outcomes than those without IBD.

Patients with infected arthroplasties are normally treated with a two-stage exchange procedure using polymethylmethacrylate bone cement spacers impregnated with antibiotics. However, spacers may act as a foreign body to which micro-organisms may adhere and grow. In this study it was hypothesised that subclinical infection may be diagnosed with sonication of the surface biofilm of the spacer. The aims were to assess the presence of subclinical infection through sonication of the spacer at the time of a second-stage procedure, and to determine the relationship between subclinical infection and the clinical outcome. Of 55 patients studied, 11 (20%) were diagnosed with subclinical infection. At a mean follow-up of 12 months (interquartile range 6 to 18), clinical failure was found in 18 (32.7%) patients. Of the patients previously diagnosed with subclinical infection, 63% (7 of 11) had failed compared with 25% (11 of 44) of those without subclinical infection (odds ratio 5.25, 95% confidence interval 1.29 to 21.4, p = 0.021). Sonication of the biofilm of the surface of the spacer is useful in order to exclude subclinical infection and therefore contributes to improving the outcome after two-stage procedures.

Peri-prosthetic fracture after joint replacement in the lower limb is associated with significant morbidity. The primary aim of this study was to investigate the incidence of peri-prosthetic fracture after total hip replacement (THR) and total knee replacement (TKR) over a ten-year period using a population-based linked dataset.

Between 1 April 1997 and 31 March 2008, 52 136 primary THRs, 8726 revision THRs, 44 511 primary TKRs, and 3222 revision TKRs were performed. Five years post-operatively, the rate of fracture was 0.9% after primary THR, 4.2% after revision THR, 0.6% after primary TKR and 1.7% after revision TKR. Comparison of survival analysis for all primary and revision arthroplasties showed peri-prosthetic fractures were more likely in females, patients aged > 70 and after revision arthroplasty.

Female patients aged > 70 should be warned of a significantly increased risk of peri-prosthetic fracture after hip or knee replacement. The use of adjuvant medical treatment to reduce the effect of peri-prosthetic osteoporosis may be a direction of research for these patients.