Aims. Closed suction subfascial drainage is widely used after instrumented posterior spinal fusion in patients with a spinal deformity. The aim of this study was to determine the effect of this wound drainage on the outcomes in patients with adolescent idiopathic scoliosis (AIS). This was a further analysis of a randomized, multicentre clinical trial reporting on patients after posterior spinal fusion using segmental pedicle screw instrumentation. In this study the incidence of deep surgical site infection (SSI) and chronic postoperative pain at two years’ follow-up are reported. Methods. We conducted a randomized, multicentre clinical trial on adolescents undergoing posterior spinal fusion for AIS using segmental pedicle screw instrumentation. A total of 90 consecutive patients were randomized into a ‘drain’ or ‘no drain’ group at the time of wound closure, using the sealed envelope technique (1:1). The primary outcomes in the initial study were the change in the level of haemoglobin in the blood postoperatively and total blood loss. A secondary outcome was the opioid consumption immediately after surgery. The aim of this further study was to report the rate of deep SSI and persistent postoperative pain, at two years' follow-up. Results. As previously reported, the mean 48-hour opioid consumption was significantly higher in the no drain group (2.0 mg/kg (SD 0.8) vs 1.4 mg/kg (SD 0.7); p = 0.005). There were no delayed deep SSIs. At two years’ follow-up, the mean Scoliosis Research Society 24-item questionnaire (SRS-24) total score did not differ between the groups (4.11 (SD 0.47) vs 4.16 (SD 0.33); p = 0.910). The mean SRS-24 pain score was 4.28 (SD 0.48) in the no drain group compared with 4.33 (SD 0.66) in the drain group (p = 0.245). Seven patients (19%) in the no drain group and six in the drain group (14%) reported moderate to severe pain (numerical rating scale ≥ 4) at two years’ follow-up (p = 0.484). The general self-image domain score was significantly higher in the no drain group compared with the drain group (4.02 (SD 0.74) vs 4.59 (SD 0.54); p < 0.001). Conclusion. The main finding in this study was that more severe pain immediately after surgery did not result in a higher incidence of chronic pain in the no drain group compared with the drain group. Back pain and health-related quality of life at two years’ follow-up did not differ between the groups. The patient-reported self-image domain was significantly better in the no drain group compared with the drain group. Cite this article: Bone Joint J 2024;106-B(10):1176–1181

Aims. Frailty has been gathering attention as a factor to predict surgical outcomes. However, the association of frailty with postoperative complications remains controversial in spinal metastases surgery. We therefore designed a prospective study to elucidate risk factors for postoperative complications with a focus on frailty. Methods. We prospectively analyzed 241 patients with spinal metastasis who underwent palliative surgery from June 2015 to December 2021. Postoperative complications were assessed by the Clavien-Dindo classification; scores of ≥ Grade II were defined as complications. Data were collected regarding demographics (age, sex, BMI, and primary cancer) and preoperative clinical factors (new Katagiri score, Frankel grade, performance status, radiotherapy, chemotherapy, spinal instability neoplastic score, modified Frailty Index-11 (mFI), diabetes, and serum albumin levels). Univariate and multivariate analyses were developed to identify risk factors for postoperative complications (p < 0.05). Results. Overall, 57 postoperative complications occurred in 47 of 241 (19.5%) patients. The most common complications were wound infection/dehiscence, urinary tract infection, and pneumonia. Univariate analysis identified preoperative radiotherapy (p = 0.028), mFI (p < 0.001), blood loss ≥ 500 ml (p = 0.016), and preoperative molecular targeted drugs (p = 0.030) as potential risk factors. From the receiver operating characteristic curve, the clinically optimal cut-off value of mFI was 0.27 (sensitivity, 46.8%; specificity, 79.9%). Multivariate analysis identified mFI ≥ 0.27 (odds ratio (OR) 2.94 (95% CI 1.44 to 5.98); p = 0.003) and preoperative radiotherapy (OR 2.11 (95% CI 1.00 to 4.46); p = 0.049) as significant risk factors. In particular, urinary tract infection (p = 0.012) and pneumonia (p = 0.037) were associated with mFI ≥ 0.27. Furthermore, the severity of postoperative complications was positively correlated with mFI (p < 0.001). Conclusion. The mFI is a useful tool to predict the incidence and the severity of postoperative complications in spinal metastases surgery. Cite this article: Bone Joint J 2024;106-B(12):1469–1476

Aims. To assess the feasibility of a randomized controlled trial (RCT) that compares three treatments for acetabular fractures in older patients: surgical fixation, surgical fixation and hip arthroplasty (fix-and-replace), and non-surgical treatment. Methods. Patients were recruited from seven UK NHS centres and randomized to a three-arm pilot trial if aged older than 60 years and had a displaced acetabular fracture. Feasibility outcomes included patients’ willingness to participate, clinicians’ capability to recruit, and dropout rates. The primary clinical outcome measure was the EuroQol five-dimension questionnaire (EQ-5D) at six months. Secondary outcomes were Oxford Hip Score, Disability Rating Index, blood loss, and radiological and mobility assessments. Results. Between December 2017 and December 2019, 60 patients were recruited (median age 77.4 years, range 63.3 to 88.5) (39/21 M/F ratio). At final nine-month follow-up, 4/60 (7%) had withdrawn, 4/60 (7%) had died, and one had been lost to follow-up; a 98% response rate (50/51) was achieved for the EQ-5D questionnaire. Four deaths were recorded during the three-year trial period: three in the non-surgical treatment group and one in the fix-and-replace group. Conclusion. This study has shown a full-scale RCT to be feasible, but will need international recruitment. The Acetabular Fractures in older patients Intervention Trial (AceFIT) has informed the design of a multinational RCT sample size of 1,474 or 1,974 patients for a minimal clinically important difference of 0.06 on EQ-5D, with a power of 0.8 or 0.9, and loss to follow-up of 20%. This observed patient cohort comprises a medically complex group requiring multidisciplinary care; surgeon, anaesthetist, and ortho-geriatrician input is needed to optimize recovery and rehabilitation. Cite this article: Bone Joint J 2024;106-B(4):401–411

Aims. Tranexamic acid (TXA) is now commonly used in major surgical operations including orthopaedics. The TRAC-24 randomized control trial (RCT) aimed to assess if an additional 24 hours of TXA postoperatively in primary total hip (THA) and total knee arthroplasty (TKA) reduced blood loss. Contrary to other orthopaedic studies to date, this trial included high-risk patients. This paper presents the results of a cost analysis undertaken alongside this RCT. Methods. TRAC-24 was a prospective RCT on patients undergoing TKA and THA. Three groups were included: Group 1 received 1 g intravenous (IV) TXA perioperatively and an additional 24-hour postoperative oral regime, Group 2 received only the perioperative dose, and Group 3 did not receive TXA. Cost analysis was performed out to day 90. Results. Group 1 was associated with the lowest mean total costs, followed by Group 2 and then Group 3. The differences between Groups 1 and 3 (-£797.77 (95% confidence interval -1,478.22 to -117.32) were statistically significant. Extended oral dosing reduced costs for patients undergoing THA but not TKA. The reduced costs in Groups 1 and 2 resulted from reduced length of stay, readmission rates, emergency department attendances, and blood transfusions. Conclusion. This study demonstrated significant cost savings when using TXA in primary THA or TKA. Extended oral dosing reduced costs further in THA but not TKA. Cite this article: Bone Jt Open 2022;3(7):536–542

Aims. The aim of this study was to assess the safety and clinical outcome of patients with a femoral shaft fracture and a previous complex post-traumatic femoral malunion who were treated with a clamshell osteotomy and fixation with an intramedullary nail (IMN). Methods. The study involved a retrospective analysis of 23 patients. All had a previous, operatively managed, femoral shaft fracture with malunion due to hardware failure. They were treated with a clamshell osteotomy between May 2015 and March 2020. The mean age was 42.6 years (26 to 62) and 15 (65.2%) were male. The mean follow-up was 2.3 years (1 to 5). Details from their medical records were analyzed. Clinical outcomes were assessed using the quality of correction of the deformity, functional recovery, the healing time of the fracture, and complications. Results. The mean length of time between the initial injury and surgery was 4.5 years (3 to 10). The mean operating time was 2.8 hours (2.05 to 4.4)), and the mean blood loss was 850 ml (650 to 1,020). Complications occurred in five patients (21.7%): two with wound necrosis, and three with deep vein thrombosis. The mean coronal deformity was significantly corrected from 17.78° (SD 4.62°) preoperatively to 1.35° (SD 1.72°) postoperatively (p < 0.001), and the mean sagittal deformity was significantly corrected from 20.65° (SD 5.88°) preoperatively to 1.61° (SD 1.95°; p < 0.001) postoperatively. The mean leg length discrepancy was significantly corrected from 3.57 cm (SD 1.27) preoperatively to 1.13 cm (SD 0.76) postoperatively (p < 0.001). All fractures healed at a mean of seven months (4 to 12) postoperatively. The mean Lower Extremity Functional Scale score improved significantly from 45.4 (SD 9.1) preoperatively to 66.2 (SD 5.5) postoperatively (p < 0.001). Partial cortical nonunion in the deformed segment occurred in eight patients (34.8%) and healed at a mean of 2.4 years (2 to 3) postoperatively. Conclusion. A clamshell osteotomy combined with IMN fixation in the treatment of patients with a femoral shaft fracture and a previous post-traumatic femoral malunion achieved excellent outcomes. Partial cortical nonunions in the deformed segment also healed satisfactorily. Cite this article: Bone Joint J 2023;105-B(4):449–454

Aims. It is not known whether preservation of the capsule of the hip positively affects patient-reported outcome measures (PROMs) in total hip arthroplasty using the direct anterior approach (DAA-THA). A recent randomized controlled trial found no clinically significant difference at one year postoperatively. This study aimed to determine whether preservation of the anterolateral capsule and anatomical closure improve the outcome and revision rate, when compared with resection of the anterolateral capsule, at two years postoperatively. Methods. Two consecutive groups of patients whose operations were performed by the senior author were compared. The anterolateral capsule was resected in the first group of 430 patients between January 2012 and December 2014, and preserved and anatomically closed in the second group of 450 patients between July 2015 and December 2017. There were no other technical changes between the two groups. Patient characteristics, the Charlson Comorbidity Index (CCI), and surgical data were collected from our database. PROM questionnaires, consisting of the Oxford Hip Score (OHS) and Core Outcome Measures Index (COMI-Hip), were collected two years postoperatively. Data were analyzed with generalized multiple regression analysis. Results. The characteristics, CCI, operating time, and length of stay were similar in both groups. There was significantly less blood loss in the capsular preservation group (p = 0.037). The revision rate (n = 3, (0.6%) in the resected group, and 1 (0.2%) in the preserved group) did not differ significantly (p = 0.295). Once adjusted for demographic and surgical factors, the preserved group had significantly worse PROMs: + 0.24 COMI-Hip (p < 0.001) and -1.6 OHS points (p = 0.017). However, the effect sizes were much smaller than the minimal clinically important differences (MCIDs) of 0.95 and 5, respectively). The date of surgery (influencing, for instance, the surgeon’s age) was not a significant factor. Conclusion. Based on the MCID, the lower PROMs in the capsular preservation group do not seem to have clinical relevance. They do not, however, confirm the expected benefit of capsular preservation reported for the posterolateral approach. Cite this article: Bone Joint J 2022;104-B(7):826–832

We have investigated the effect of using tranexamic acid (TXA) during peri-acetabular osteotomy (PAO) on peri-operative blood loss and blood transfusion requirements. In addition we analysed whether the use of TXA was associated with an increased risk of venous thromboembolism (VTE) following this procedure. A consecutive series of 96 PAOs, performed by a single surgeon, were reviewed. A total of 48 patients received TXA and 48 did not. The TXA group received a continuous infusion of TXA at a rate of 10 mg/kg/h. The primary outcome measure was the requirement for blood transfusion. Secondary outcomes included total blood loss, the decrease in the level of haemoglobin in the blood, the length of hospital stay, and the complications of this treatment. The mean rate of transfusion was significantly lower in the TXA group (62.5% vs 12.5%, p < 0.001). The mean blood loss was also significantly reduced in the TXA group (1.9 L (standard deviation (. sd. ) 0.9) vs 1.5 L (. sd. 0.7), p < 0.01). No post-operative episodes of VTE were identified in either group. . The use of TXA reduced the blood loss and the rate of transfusion after PAO significantly, without adverse effects such as an increased rate of VTE. Cite this article: Bone Joint J 2015;97-B:1604–7

This edition of the Cochrane Corner looks at the three reviews that were published in the second half of 2023: surgical versus non-surgical interventions for displaced intra-articular calcaneal fractures; cryotherapy following total knee arthroplasty; and physical activity and education about physical activity for chronic musculoskeletal pain in children and adolescents.

Aims

The aim of this study was to perform a systematic review of the evidence for the use of intraoperative cell salvage in patients undergoing revision hip arthroplasty, and specifically to analyze the available data in order to quantify any associated reduction in the use of allogenic blood transfusion, and the volume which is used.

Aims. A variety of surgical methods and strategies have been demonstrated for Andersson lesion (AL) therapy. In 2011, we proposed and identified the feasibility of stabilizing the spine without curettaging the vertebral or discovertebral lesion to cure non-kyphotic AL. Additionally, due to the excellent reunion ability of ankylosing spondylitis, we further came up with minimally invasive spinal surgery (MIS) to avoid the need for both bone graft and lesion curettage in AL surgery. However, there is a paucity of research into the comparison between open spinal fusion (OSF) and early MIS in the treatment of AL. The purpose of this study was to investigate and compare the clinical outcomes and radiological evaluation of our early MIS approach and OSF for AL. Methods. A total of 39 patients diagnosed with AL who underwent surgery from January 2004 to December 2022 were retrospectively screened for eligibility. Patients with AL were divided into an MIS group and an OSF group. The primary outcomes were union of the lesion on radiograph and CT, as well as the visual analogue scale (VAS) and Oswestry Disability Index (ODI) scores immediately after surgery, and at the follow-up (mean 29 months (standard error (SE) 9)). The secondary outcomes were total blood loss during surgery, operating time, and improvement in the radiological parameters: global and local kyphosis, sagittal vertical axis, sagittal alignment, and chin-brow vertical angle immediately after surgery and at the follow-up. Results. Data for 30 patients with AL were evaluated: 14 in the MIS group and 16 in the OSF group. All patients were followed up after surgery; no nonunion complications or instrumentation failures were observed in either group. No significant differences in the VAS and ODI scores were identified between the two groups. Mean ODI improved from 51 (SE 5) to 17 (SE 5) in the MIS group and from 52 (SE 6) to 19 (SE 5) in the OSF group at the follow-up. There were significant improvements in total blood loss (p = 0.025) and operating time (p < 0.001) between the groups. There was also no significant difference in local kyphosis six months postoperatively (p = 0.119). Conclusion. Early MIS is an effective treatment for AL. MIS provides comparable clinical outcomes to those treated with OSF, with less total blood loss and shorter operating time. Our results support and identify the feasibility of solid immobilization achieved by posterior instrumentation without bone graft via MIS for the treatment of AL. Cite this article: Bone Jt Open 2024;5(10):886–893

Aims. Medial humeral epicondyle fractures (MHEFs) are common elbow fractures in children. Open reduction should be performed in patients with MHEF who have entrapped intra-articular fragments as well as displacement. However, following open reduction, transposition of the ulnar nerve is disputed. The aim of this study is to evaluate the need for ulnar nerve exploration and transposition. Methods. This was a retrospective cohort study. The clinical data of patients who underwent surgical treatment of MHEF in our hospital from January 2015 to January 2022 were collected. The patients were allocated to either transposition or non-transposition groups. Data for sex, age, cause of fracture, duration of follow-up, Papavasiliou and Crawford classification, injury-to-surgery time, preoperative ulnar nerve symptoms, intraoperative exploration of ulnar nerve injury, surgical incision length, intraoperative blood loss, postoperative ulnar nerve symptoms, complications, persistent ulnar neuropathy, and elbow joint function were analyzed. Binary logistic regression analysis was used for statistical analysis. Results. A total of 124 patients were followed up, 50 in the ulnar nerve transposition group and 74 in the non-transposition group. There were significant differences in ulnar nerve injury (p = 0.009), incision length (p < 0.001), and blood loss (p = 0.003) between the two groups. Binary logistic regression analysis revealed that preoperative ulnar nerve symptoms (p = 0.012) were risk factors for postoperative ulnar nerve symptoms. In addition, ulnar nerve transposition did not affect the occurrence of postoperative ulnar nerve symptoms (p = 0.468). Conclusion. Ulnar nerve transposition did not improve clinical outcomes. It is recommended that the ulnar nerve should not be transposed when treating MHEF operatively. Cite this article: Bone Joint J 2024;106-B(2):212–218

Aims. The incidence of limb fractures in patients living with HIV (PLWH) is increasing. However, due to their immunodeficiency status, the operation and rehabilitation of these patients present unique challenges. Currently, it is urgent to establish a standardized perioperative rehabilitation plan based on the concept of enhanced recovery after surgery (ERAS). This study aimed to validate the effectiveness of ERAS in the perioperative period of PLWH with limb fractures. Methods. A total of 120 PLWH with limb fractures, between January 2015 and December 2023, were included in this study. We established a multidisciplinary team to design and implement a standardized ERAS protocol. The demographic, surgical, clinical, and follow-up information of the patients were collected and analyzed retrospectively. Results. Compared with the control group, the ERAS group had a shorter operating time, hospital stay, preoperative waiting time, postoperative discharge time, less intraoperative blood loss, and higher albumin and haemoglobin on the first postoperative day. The time to removal of the urinary catheter/drainage tube was shortened, and the drainage volume was also significantly reduced in the ERAS group. There was no significant difference in the visual analogue scale (VAS) scores on postoperative return to the ward, but the ERAS group had lower scores on the first, second, and third postoperative days. There were no significant differences in the incidence of complications, other than 10% more nausea and vomiting in the control group. The limb function scores at one-year follow-up were similar between the two groups, but time to radiological fracture union and time to return to physical work and sports were significantly reduced in the ERAS group. Conclusion. The implementation of a series of perioperative nursing measures based on the concept of ERAS in PLWH with limb fracture can significantly reduce the operating time and intraoperative blood loss, reduce the occurrence of postoperative pain and complications, and accelerate the improvement of the functional status of the affected limb in the early stage, which is worthy of applying in more medical institutions. Cite this article: Bone Joint Res 2024;13(11):647–658

Aims. Surgical approaches to cervical ossification of the posterior longitudinal ligament (OPLL) remain controversial. The purpose of the present study was to analyze and compare the long-term neurological recovery following anterior decompression with fusion (ADF) and posterior laminectomy and fusion with bone graft and internal fixation (PLF) based on > ten-year follow-up outcomes in a single centre. Methods. Included in this retrospective cohort study were 48 patients (12 females; mean age 55.79 years (SD 8.94)) who were diagnosed with cervical OPLL, received treatment in our centre, and were followed up for 10.22 to 15.25 years. Of them, 24 patients (six females; mean age 52.88 years (SD 8.79)) received ADF, and the other 24 patients (five females; mean age 56.25 years (SD 9.44)) received PLF. Clinical data including age, sex, and the OPLL canal-occupying ratio were analyzed and compared. The primary outcome was Japanese Orthopaedic Association (JOA) score, and the secondary outcome was visual analogue scale neck pain. Results. Compared with the baseline, neurological function improved significantly after surgery in all patients of both groups (p < 0.001). The JOA recovery rate in the ADF group was significantly higher than that in the PLF group (p < 0.001). There was no significant difference in postoperative cervical pain between the two groups (p = 0.387). The operating time was longer and intraoperative blood loss was greater in the PLF group than the ADF group. More complications were observed in the ADF group than in the PLF group, although the difference was not statistically significant. Conclusion. Long-term neurological function improved significantly after surgery in both groups, with the improvement more pronounced in the ADF group. There was no significant difference in postoperative neck pain between the two groups. The operating time was shorter and intraoperative blood loss was lower in the ADF group; however, the incidence of perioperative complications was higher. Cite this article: Bone Jt Open 2024;5(9):768–775

Aims. The aim of this study was to identify the most effective regimen of multiple doses of oral tranexamic acid (TXA) in achieving maximum reduction of blood loss in total knee arthroplasty (TKA). Patients and Methods. In this randomized controlled trial, 200 patients were randomized to receive a single dose of 2.0 g of TXA orally two hours preoperatively (group A), a single dose of TXA followed by 1.0 g orally three hours postoperatively (group B), a single dose of TXA followed by 1.0 g three and nine hours postoperatively (group C), or a single dose of TXA followed by 1.0 g orally three, nine, and 15 hours postoperatively (group D). All patients followed a routine enhanced-recovery protocol. The primary outcome measure was the total blood loss. Secondary outcome measures were hidden blood loss (HBL), reduction in the level of haemoglobin, the rate of transfusion and adverse events. Results. Groups C (661.1 ml, . sd. 262.4) and D (597.7 ml, . sd. 219.6) had significantly lower mean total blood loss compared with groups A and B. The mean HBL was significantly lower in groups B (699.2 ml), C (533.1 ml) and D (469.9 ml) than in group A (p = 0.006, p < 0.001, and p < 0.001, respectively). Groups C (2.22 ml, . sd. 0.91) and D (2.04 ml, . sd. 0.95) had a lower reduction in the level of haemoglobin than groups A and B. However, there were no differences between groups C and D in relation to the three parameters. Conclusion. The addition of two or three postoperative doses of TXA to one preoperative dose produced a significant reduction in blood loss. The two-dose postoperative regimen is the least necessary regimen for clinical efficacy in primary unilateral TKA. The three-dose regimen produced maximum reduction of blood loss. Cite this article: Bone Joint J 2018;100-B:1025–32

Aims. There is evidence that morbidly obese patients have more intra- and postoperative complications and poorer outcomes when undergoing total hip arthroplasty (THA) with the direct anterior approach (DAA). The aim of this study was to determine the efficacy of DAA for THA, and compare the complications and outcomes of morbidly obese patients with nonobese patients. Methods. Morbidly obese patients (n = 86), with BMI ≥ 40 kg/m. 2. who underwent DAA THA at our institution between September 2010 and December 2017, were matched to 172 patients with BMI < 30 kg/m. 2. Data regarding demographics, set-up and operating time, blood loss, radiological assessment, Harris Hip Score (HHS), International Hip Outcome Tool (12-items), reoperation rate, and complications at two years postoperatively were retrospectively analyzed. Results. No significant differences in blood loss, intra- and postoperative complications, or implant position were observed between the two groups. Superficial wound infection rate was higher in the obese group (8.1%) compared to the nonobese group (1.2%) (p = 0.007) and relative risk of reoperation was 2.59 (95% confidence interval 0.68 to 9.91). One periprosthetic joint infection was reported in the obese group. Set-up time in the operating table and mean operating time were higher in morbidly obese patients. Functional outcomes and patient-related outcome measurements were superior in the obese group (mean increase of HHS was 52.19 (SD 5.95) vs 45.1 (SD 4.42); p < 0.001), and mean increase of International Hip Outcome Tool (12-items) was 56.8 (SD 8.88) versus 55.2 (SD 5.85); p = 0.041). Conclusion. Our results suggest that THA in morbidly obese patients can be safely and effectively performed via the DAA by experienced surgeons. Cite this article: Bone Jt Open 2022;3(1):4–11

Aims. The aim of this study was to investigate the safety and efficacy of 3D-printed modular prostheses in patients who underwent joint-sparing limb salvage surgery (JSLSS) for malignant femoral diaphyseal bone tumours. Methods. We retrospectively reviewed 17 patients (13 males and four females) with femoral diaphyseal tumours who underwent JSLSS in our hospital. Results. In all, 17 patients with locally aggressive bone tumours (Enneking stage IIB) located in the femoral shaft underwent JSLSS and reconstruction with 3D-printed modular prostheses between January 2020 and June 2022. The median surgical time was 153 minutes (interquartile range (IQR) 117 to 248), and the median estimated blood loss was 200ml (IQR 125 to 400). Osteosarcoma was the most common pathological type (n = 12; 70.6%). The mean osteotomy length was 197.53 mm (SD 12.34), and the median follow-up was 25 months (IQR 19 to 38). Two patients experienced local recurrence and three developed distant metastases. Postoperative complications included wound infection in one patient and screw loosening in another, both of which were treated successfully with revision surgery. The median Musculoskeletal Tumor Society score at the final follow-up was 28 (IQR 27 to 28). Conclusion. The 3D-printed modular prosthesis is a reliable and feasible reconstruction option for patients with malignant femoral diaphyseal tumours. It helps to improve the limb salvage rate, restore limb function, and achieve better short-term effectiveness. Cite this article: Bone Jt Open 2024;5(4):317–323

Aims. Many surgeons choose to perform total knee arthroplasty (TKA) surgery with the aid of a tourniquet. A tourniquet is a device that fits around the leg and restricts blood flow to the limb. There is a need to understand whether tourniquets are safe, and if they benefit, or harm, patients. The aim of this study was to determine the benefits and harms of tourniquet use in TKA surgery. Methods. We searched MEDLINE, EMBASE, Cochrane Central Register of Controlled trials, and trial registries up to 26 March 2020. We included randomized controlled trials (RCTs), comparing TKA with a tourniquet versus without a tourniquet. Outcomes included: pain, function, serious adverse events (SAEs), blood loss, implant stability, duration of surgery, and length of hospital stay. Results. We included 41 RCTs with 2,819 participants. SAEs were significantly more common in the tourniquet group (53/901 vs 26/898, tourniquet vs no tourniquet respectively) (risk ratio 1.73 (95% confidence interval (CI) 1.10 to 2.73). The mean pain score on the first postoperative day was 1.25 points higher (95% CI 0.32 to 2.19) in the tourniquet group. Overall blood loss did not differ between groups (mean difference 8.61 ml; 95% CI -83.76 to 100.97). The mean length of hospital stay was 0.34 days longer in the group that had surgery with a tourniquet (95% CI 0.03 to 0.64) and the mean duration of surgery was 3.7 minutes shorter (95% CI -5.53 to -1.87). Conclusion. TKA with a tourniquet is associated with an increased risk of SAEs, pain, and a marginally longer hospital stay. The only finding in favour of tourniquet use was a shorter time in theatre. The results make it difficult to justify the routine use of a tourniquet in TKA surgery. Cite this article: Bone Joint J 2021;103-B(5):830–839