Aims: We aim to evaluate the usefulness of postoperative blood tests by investigating the incidence of abnormal results following total joint replacement (TJR), as well as identifying preoperative risk factors for abnormal blood test results postoperatively, especially pertaining to anaemia and acute kidney injury (AKI).Methods: This is a retrospective cohort study of patients who had elective TJR between January and December 2019 at a tertiary centre. Data gathered included age at time of surgery, sex, BMI, American Society of Anesthesiologists (ASA) grade, preoperative and postoperative laboratory test results, haemoglobin (Hgb), white blood count (WBC), haematocrit (Hct), platelets (Plts), sodium (Na⁺), potassium (K⁺), creatinine (Cr), estimated glomerular filtration rate (eGFR), and Ferritin (ug/l). Abnormal blood tests, AKI, electrolyte imbalance, anaemia, transfusion, reoperation, and readmission within one year were reported.Results: The study included 2,721 patients with a mean age of 69 years, of whom 1,266 (46.6%) were male. Abnormal postoperative bloods were identified in 444 (16.3%) patients. We identified age (≥ 65 years), female sex, and ASA grade ≥ III as risk factors for developing abnormal postoperative blood tests. Preoperative haemoglobin (≤ 127 g/dl) and packed cell volume (≤ 0.395 l/l) were noted to be significant risk factors for postoperative anaemia, and potassium (≤ 3.7 mmol/l) was noted to be a significant risk factor for AKI.Conclusion: The costs outweigh the benefits of ordering routine postoperative blood tests in TJR patients. Clinicians should risk-stratify their patients and have a lower threshold for ordering blood tests in patients with abnormal preoperative haemoglobin (≤ 127 g/l), blood loss > 300 ml, chronic kidney disease, ASA grade ≥ III, and clinical concern.Cite this article: Bone Jt Open 2023;4(11):899–905.

In this review, we aim to provide a concise yet comprehensive summation of the assessment and management of humeral shaft fractures. These are uncommon but prevalent enough that they are part of any trauma surgeon's scope of practice. They have historically been treated using non-operative methods, including braces and casts, supported by published excellent results in the rate of the bone union. However, recently published studies challenge these results and suggest the outcomes might be better with surgery, but the complications of an operation such as infection and nerve injury can not be overlooked. In summary, non-surgical treatment is still the gold standard in the treatment of these fractures, but the indications for surgical management are now clearer and include early signs of delayed union and patients who are unable to have a brace fitted or are uncompliant. It is likely that these new developments will start to change practice, and therefore the treatment of humeral shaft fractures should be a topic of interest of any clinician who deals with them.