Aims

In total knee arthroplasty (TKA), blood loss continues internally after surgery is complete. Typically, the total loss over 48 postoperative hours can be around 1,300 ml, with most occurring within the first 24 hours. We hypothesize that the full potential of tranexamic acid (TXA) to decrease TKA blood loss has not yet been harnessed because it is rarely used beyond the intraoperative period, and is usually withheld from ‘high-risk’ patients with a history of thromboembolic, cardiovascular, or cerebrovascular disease, a patient group who would benefit greatly from a reduced blood loss.

Aims

We studied the safety and efficacy of multimodal thromboprophylaxis in patients with a history of venous thromboembolism (VTE) who undergo total hip arthroplasty (THA) within the first 120 postoperative days, and the mortality during the first year. Multimodal prophylaxis includes discontinuation of procoagulant medications, VTE risk stratification, regional anaesthesia, an intravenous bolus of unfractionated heparin prior to femoral preparation, rapid mobilization, the use of pneumatic compression devices, and chemoprophylaxis tailored to the patient’s risk of VTE.

Aims. Natural Language Processing (NLP) offers an automated method to extract data from unstructured free text fields for arthroplasty registry participation. Our objective was to investigate how accurately NLP can be used to extract structured clinical data from unstructured clinical notes when compared with manual data extraction. Methods. A group of 1,000 randomly selected clinical and hospital notes from eight different surgeons were collected for patients undergoing primary arthroplasty between 2012 and 2018. In all, 19 preoperative, 17 operative, and two postoperative variables of interest were manually extracted from these notes. A NLP algorithm was created to automatically extract these variables from a training sample of these notes, and the algorithm was tested on a random test sample of notes. Performance of the NLP algorithm was measured in Statistical Analysis System (SAS) by calculating the accuracy of the variables collected, the ability of the algorithm to collect the correct information when it was indeed in the note (sensitivity), and the ability of the algorithm to not collect a certain data element when it was not in the note (specificity). Results. The NLP algorithm performed well at extracting variables from unstructured data in our random test dataset (accuracy = 96.3%, sensitivity = 95.2%, and specificity = 97.4%). It performed better at extracting data that were in a structured, templated format such as range of movement (ROM) (accuracy = 98%) and implant brand (accuracy = 98%) than data that were entered with variation depending on the author of the note such as the presence of deep-vein thrombosis (DVT) (accuracy = 90%). Conclusion. The NLP algorithm used in this study was able to identify a subset of variables from randomly selected unstructured notes in arthroplasty with an accuracy above 90%. For some variables, such as objective exam data, the accuracy was very high. Our findings suggest that automated algorithms using NLP can help orthopaedic practices retrospectively collect information for registries and quality improvement (QI) efforts. Cite this article: Bone Joint J 2020;102-B(7 Supple B):99–104

Aims

The aim of this study was to examine the efficacy and safety of multiple boluses of intravenous (IV) tranexamic acid (TXA) on the hidden blood loss (HBL) and inflammatory response following primary total hip arthroplasty (THA).

Tranexamic acid (TXA), an inhibitor of fibrinolysis, reduces blood loss after total knee arthroplasty. However, its effect on minimally invasive total hip arthroplasty (THA) is not clear. We performed a prospective, randomised double-blind study to evaluate the effect of two intravenous injections of TXA on blood loss in patients undergoing minimally invasive THA.

In total, 60 patients (35 women and 25 men with a mean age of 58.1 years; 17 to 84) who underwent unilateral minimally invasive uncemented THA were randomly divided into the study group (30 patients, 20 women and ten men with a mean age of 56.5 years; 17 to 79) that received two intravenous injections 1 g of TXA pre- and post-operatively (TXA group), and a placebo group (30 patients, 15 women and 15 men with a mean age of 59.5 years; 23 to 84). We compared the peri-operative blood loss of the two groups. Actual blood loss was calculated from the maximum reduction in the level of haemoglobin. All patients were followed clinically for the presence of venous thromboembolism.

The TXA group had a lower mean intra-operative blood loss of 441 ml (150 to 800) versus 615 ml (50 to 1580) in the placebo (p = 0.044), lower mean post-operative blood loss (285 ml (120 to 570) versus 392 ml (126 to 660) (p = 0.002), lower mean total blood loss (1070 ml (688 to 1478) versus 1337 ml (495 to 2238) (p = 0.004) and lower requirement for transfusion (p = 0.021). No patients in either group had symptoms of venous thromboembolism or wound complications.

This prospective, randomised controlled study showed that a regimen of two intravenous injections of 1 g TXA is effective for blood conservation after minimally invasive THA.

Cite this article: Bone Joint J 2015;97-B:905–10.

We performed a case–control study to compare the rates of further surgery, revision and complications, operating time and survival in patients who were treated with either an uncemented hydroxyapatite-coated Corail bipolar femoral stem or a cemented Exeter stem for a displaced intracapsular fracture of the hip. The mean age of the patients in the uncemented group was 82.5 years (53 to 97) and in the cemented group was 82.7 years (51 to 99) We used propensity score matching, adjusting for age, gender and the presence or absence of dementia and comorbidities, to produce a matched cohort receiving an Exeter stem (n = 69) with which to compare the outcome of patients receiving a Corail stem (n = 69). The Corail had a significantly lower all-cause rate of further surgery (p = 0.016; odds ratio (OR) 0.18, 95% CI 0.04 to 0.84) and number of hips undergoing major further surgery (p = 0.029; OR 0.13, 95% CI 0.01 to 1.09). The mean operating time was significantly less for the Corail group than for the cemented Exeter group (59 min [12 to 136] vs 70 min [40 to 175], p = 0.001). The Corail group also had a lower risk of a peri-prosthetic fracture (p = 0.042; OR 0.19, 95% CI 0.01 to 1.42) . There was no difference in the mortality rate between the groups. There were significantly fewer complications in the uncemented group, suggesting that the use of this stem would result in a decreased rate of morbidity in these frail patients. Whether this relates to an improved functional outcome remains unknown.

Cite this article: Bone Joint J 2014;96-B:299–305.

In an initial randomised controlled trial (RCT) we segregated 180 patients to one of two knee positions following total knee replacement (TKR): six hours of knee flexion using either a jig or knee extension. Outcome measures included post-operative blood loss, fall in haemoglobin, blood transfusion requirements, knee range of movement, limb swelling and functional scores. A second RCT consisted of 420 TKR patients randomised to one of three post-operative knee positions: flexion for three or six hours post-operatively, or knee extension.

Positioning of the knee in flexion for six hours immediately after surgery significantly reduced blood loss (p = 0.002). There were no significant differences in post-operative range of movement, swelling, pain or outcome scores between the various knee positions in either study. Post-operative knee flexion may offer a simple and cost-effective way to reduce blood loss and transfusion requirements following TKR.

We also report a cautionary note regarding the potential risks of prolonged knee flexion for more than six hours observed during clinical practice in the intervening period between the two trials, with 14 of 289 patients (4.7%) reporting lower limb sensory neuropathy at their three-month review.

Cite this article: Bone Joint J 2014;96-B:201–9.

We have reviewed the current literature to compare the results of surgery aimed to repair or debride a damaged acetabular labrum. We identified 28 studies to be included in the review containing a total of 1631 hips in 1609 patients. Of these studies 12 reported a mean rate of good results of 82% (from 67% to 100%) for labral debridement. Of the 16 studies that reported a combination of debridement and re-attachment, five reported a comparative outcome for the two methods, four reported better results with re-attachment and one study did not find any significant difference in outcomes. Due to the heterogeneity of the studies it was not possible to perform a meta-analysis or draw accurate conclusions. Confounding factors in the studies include selection bias, use of historical controls and high rates of loss of follow-up.

It seems logical to repair an unstable tear in a good quality labrum with good potential to heal in order potentially to preserve its physiological function. A degenerative labrum on the other hand may be the source of discomfort and its preservation may result in persistent pain and the added risk of failure of re-attachment. The results of the present study do not support routine refixation for all labral tears.

Cite this article: Bone Joint J 2014;96-B:24–30.

A total of 219 hips in 192 patients aged between 18 and 65 years were randomised to 28-mm metal-on-metal uncemented total hip replacements (THRs, 107 hips) or hybrid hip resurfacing (HR, 112 hips). At a mean follow-up of eight years (6.6 to 9.3) there was no significant difference between the THR and HR groups regarding rate of revision (4.0% (4 of 99) vs 5.8% (6 of 104), p = 0.569) or re-operation rates without revision (5.1% (5 of 99) vs 2.9% (3 of 104), p = 0.428). In the THR group one recurrent dislocation, two late deep infections and one peri-prosthetic fracture required revision, whereas in the HR group five patients underwent revision for femoral head loosening and one for adverse reaction to metal debris. The mean University of California, Los Angeles activity scores were significantly higher in HR (7.5 (sd 1.7) vs 6.9 (sd 1.7), p = 0.035), but similar mean Western Ontario and McMaster Universities Osteoarthritis Index scores were obtained (5.8 (sd 9.5) in HR vs 5.1 (sd 8.9) in THR, p = 0.615) at the last follow-up. Osteolysis was found in 30 of 81 THR patients (37.4%), mostly in the proximal femur, compared with two of 83 HR patients (2.4%) (p < 0.001). At five years the mean metal ion levels were < 2.5 μg/l for cobalt and chromium in both groups; only titanium was significantly higher in the HR group (p = 0.001). Although revision rates and functional scores were similar in both groups at mid-term, long-term survival analysis is necessary to determine whether one procedure is more advantageous than the other.

Cite this article: Bone Joint J 2013;95-B:1464–73.

In our department we use an enhanced recovery protocol for joint replacement of the lower limb. This incorporates the use of intravenous tranexamic acid (IVTA; 15 mg/kg) at the induction of anaesthesia. Recently there was a national shortage of IVTA for 18 weeks; during this period all patients received an oral preparation of tranexamic acid (OTA; 25 mg/kg). This retrospective study compares the safety (surgical and medical complications) and efficacy (reduction of transfusion requirements) of OTA and IVTA. During the study period a total of 2698 patients received IVTA and 302 received OTA. After adjusting for a range of patient and surgical factors, the odds ratio (OR) of receiving a blood transfusion was significantly higher with IVTA than with OTA (OR 0.48 (95% confidence interval 0.26 to 0.89), p = 0.019), whereas the safety profile was similar, based on length of stay, rate of readmission, return to theatre, deep infection, stroke, gastrointestinal bleeding, myocardial infarction, pneumonia, deep-vein thrombosis and pulmonary embolism. The financial benefit of OTA is £2.04 for a 70 kg patient; this is amplified when the cost saving associated with significantly fewer blood transfusions is considered. Although the number of patients in the study is modest, this work supports the use of OTA, and we recommend that a randomised trial be undertaken to compare the different methods of administering tranexamic acid. Cite this article: Bone Joint J 2013;95-B:1556–61

Total hip replacement (THR) has been shown to be a cost-effective procedure. However, it is not risk-free. Certain conditions, such as diabetes mellitus, are thought to increase the risk of complications. In this study we have evaluated the prevalence of diabetes mellitus in patients undergoing THR and the associated risk of adverse operative outcomes. A meta-analysis and systematic review were conducted according to the guidelines of the meta-analysis of observational studies in epidemiology. Inclusion criteria were observational studies reporting the prevalence of diabetes in the study population, accompanied by reports of at least one of the following outcomes: venous thromboembolic events; acute coronary events; infections of the urinary tract, lower respiratory tract or surgical site; or requirement for revision arthroplasty. Altman and Bland’s methods were used to calculate differences in relative risks. The prevalence of diabetes mellitus was found to be 5.0% among patients undergoing THR, and was associated with an increased risk of established surgical site infection (odds ratio (OR) 2.04 (95% confidence interval (CI) 1.52 to 2.76)), urinary infection (OR 1.43 (95% CI 1.33 to 1.55)) and lower respiratory tract infections (OR 1.95 (95% CI 1.61 to 2.26)). Diabetes mellitus is a relatively common comorbidity encountered in THR. Diabetic patients have a higher rate of developing both surgical site and non-surgical site infections following THR.

Cite this article: Bone Joint J 2013;95-B:1474–9.

Total knee replacement (TKR) is one of the most common operations in orthopaedic surgery worldwide. Despite its scientific reputation as mainly successful, only 81% to 89% of patients are satisfied with the final result. Our understanding of this discordance between patient and surgeon satisfaction is limited. In our experience, focus on five major factors can improve patient satisfaction rates: correct patient selection, setting of appropriate expectations, avoiding preventable complications, knowledge of the finer points of the operation, and the use of both pre- and post-operative pathways. Awareness of the existence, as well as the identification of predictors of patient–surgeon discordance should potentially help with enhancing patient outcomes.

Cite this article: Bone Joint J 2013;95-B, Supple A:120–3.

We hypothesised that the use of computer navigation-assisted surgery for pelvic and sacral tumours would reduce the risk of an intralesional margin. We reviewed 31 patients (18 men and 13 women) with a mean age of 52.9 years (13.5 to 77.2) in whom computer navigation-assisted surgery had been carried out for a bone tumour of the pelvis or sacrum. There were 23 primary malignant bone tumours, four metastatic tumours and four locally advanced primary tumours of the rectum. The registration error when using computer navigation was <  1 mm in each case. There were no complications related to the navigation, which allowed the preservation of sacral nerve roots (n = 13), resection of otherwise inoperable disease (n = 4) and the avoidance of hindquarter amputation (n = 3). The intralesional resection rate for primary tumours of the pelvis and sacrum was 8.7% (n = 2): clear bone resection margins were achieved in all cases. At a mean follow-up of 13.1 months (3 to 34) three patients (13%) had developed a local recurrence. The mean time alive from diagnosis was 16.8 months (4 to 48).

Computer navigation-assisted surgery is safe and has reduced our intralesional resection rate for primary tumours of the pelvis and sacrum. We recommend this technique as being worthy of further consideration for this group of patients.

Cite this article: Bone Joint J 2013;95-B:1417–24.

The aim of this study was to define the incidence of venous thromboembolism (VTE) and risk factors for the development of deep-vein thrombosis (DVT) after the resection of a musculoskeletal tumour. A total of 94 patients who underwent resection of a musculoskeletal tumour between January 2003 and December 2005 were prospectively studied. There were 42 men and 52 women with a mean age of 54.4 years (18 to 86). All patients wore intermittent pneumatic compression devices and graduated compression stockings. Ultrasound examination of the lower limbs was conducted to screen for DVT between the fifth and ninth post-operative days. DVT was detected in 21 patients (22%). Of these, two were symptomatic (2%). One patient (1%) had a fatal pulmonary embolism. Patients aged ≥ 70 years had an increased risk of DVT (p = 0.004). The overall incidence of DVT (both symptomatic and asymptomatic) after resection of a musculoskeletal tumour with mechanical prophylaxis was high. It seems that both mechanical and anticoagulant prophylaxis is needed to prevent VTE in patients who have undergone the resection of a musculoskeletal tumour. Cite this article: Bone Joint J 2013;95-B:1280–4

We hypothesised that adjuvant intermittent pneumatic compression (IPC) beneath a plaster cast would reduce the risk of deep-vein thrombosis (DVT) during post-operative immobilisation of the lower limb. Of 87 patients with acute tendo Achillis (TA) rupture, 26 were prospectively randomised post-operatively after open TA repair. The treatment group (n = 14) received two weeks of IPC of the foot for at least six hours daily under a plaster cast. The control group (n = 12) had no additional treatment. At two weeks post-operatively all patients received an orthosis until follow-up at six weeks. At two and six weeks the incidence of DVT was assessed using colour duplex sonography by two ultrasonographers blinded to the treatment. Two patients withdrew from the study due to inability to tolerate IPC treatment.

An interim analysis demonstrated a high incidence of DVT in both the IPC group (9 of 12, 75%) and the controls (6 of 12, 50%) (p = 0.18). No significant differences in incidence were detected at two (p = 0.33) or six weeks (p = 0.08) post-operatively. Malfunction of the IPC leading to a second plaster cast was found to correlate with an increased DVT risk at two weeks (φ = 0.71; p = 0.019), leading to a premature abandonment of the study.

We cannot recommend adjuvant treatment with foot IPC under a plaster cast for outpatient DVT prevention during post-operative immobilisation, owing to a high incidence of DVT related to malfunctioning of this type of IPC application.

Cite this article: Bone Joint J 2013;95-B:1227–31.

The purpose of this study was to examine the complications and outcomes of total hip replacement (THR) in super-obese patients (body mass index (BMI) > 50 kg/m²) compared with class I obese (BMI 30 to 34.9 kg/m²) and normal-weight patients (BMI 18.5 to 24.9 kg/m²), as defined by the World Health Organization.

A total of 39 THRs were performed in 30 super-obese patients with a mean age of 53 years (31 to 72), who were followed for a mean of 4.2 years (2.0 to 11.7). This group was matched with two cohorts of normal-weight and class I obese patients, each comprising 39 THRs in 39 patients. Statistical analysis was performed to determine differences among these groups with respect to complications and satisfaction based on the Western Ontario and McMaster Universities (WOMAC) osteoarthritis index, the Harris hip score (HHS) and the Short-Form (SF)-12 questionnaire.

Super-obese patients experienced significantly longer hospital stays and higher rates of major complications and readmissions than normal-weight and class I obese patients. Although super-obese patients demonstrated reduced pre-operative and post-operative satisfaction scores, there was no significant difference in improvement, or change in the score, with respect to HHS or the WOMAC osteoarthritis index.

Super-obese patients obtain similar satisfaction outcomes as class I obese and normal-weight patients with respect to improvement in their scores. However, they experience a significant increase in length of hospital stay and major complication and readmission rates.

Cite this article: Bone Joint J 2013;95-B:758–63.

We prospectively followed 171 patients who underwent bilateral unicompartmental knee replacement (UKR) over a period of two years. Of these, 124 (72.5%) underwent a simultaneous bilateral procedure and 47 (27.5%) underwent a staged procedure. The mean cumulative operating time and length of hospital stay were both shorter in the simultaneous group, by 22.5 minutes (p < 0.001) and three days (p < 0.001), respectively. The mean reduction in haemoglobin level post-operatively was greater by 0.15 g/dl in the simultaneous group (p = 0.023), but this did not translate into a significant increase in the number of patients requiring blood transfusion (p = 1.000). The mean hospital cost was lower by $8892 in the simultaneous group (p < 0.001). There was no significant difference in the rate of complications between the groups, and at two-year follow-up there was no difference in the outcomes between the two groups.

We conclude that simultaneous bilateral UKR can be recommended as an appropriate treatment for patients with bilateral medial compartment osteoarthritis of the knee.

Cite this article: Bone Joint J 2013;95-B:788–92.

Autologous retransfusion and no-drainage are both blood-saving measures in total hip replacement (THR). A new combined intra- and post-operative autotransfusion filter system has been developed especially for primary THR, and we conducted a randomised controlled blinded study comparing this with no-drainage.

A total of 204 THR patients were randomised to autologous blood transfusion (ABT) (n = 102) or no-drainage (n = 102). In the ABT group, a mean of 488 ml (sd 252) of blood was retransfused. The mean lowest post-operative haemoglobin level during the hospital stay was higher in the autotransfusion group (10.6 g/dl (7.8 to 13.9) vs 10.2 g/dl (7.5 to 13.3); p = 0.01). The mean haemoglobin levels for the ABT and no-drainage groups were not significantly different on the first day (11.3 g/dl (7.8 to 13.9) vs 11.0 g/dl (8.1 to 13.4); p = 0.07), the second day (11.1 g/dl (8.2 to 13.8) vs 10.8 g/dl (7.5 to 13.3); p = 0.09) or the third day (10.8 g/dl (8.0 to 13.0) vs 10.6 g/dl (7.5 to 14.1); p = 0.15). The mean total peri-operative net blood loss was 1464 ml (sd 505) in the ABT group and 1654 ml (sd 553) in the no-drainage group (p = 0.01). Homologous blood transfusions were needed in four patients (3.9%) in the ABT group and nine (8.8%) in the no-drainage group (p = 0.15). No statistically significant difference in adverse events was found between the groups.

The use of a new intra- and post-operative autologous blood transfusion filter system results in less total blood loss and a smaller maximum decrease in haemoglobin levels than no-drainage following primary THR.

Cite this article: Bone Joint J 2013;95-B:616–22.

This paper reports the cost of outpatient venous thromboembolism (VTE) prophylaxis following 388 injuries of the lower limb requiring immobilisation in our institution, from a total of 7408 new patients presenting between May and November 2011. Prophylaxis was by either self-administered subcutaneous dalteparin (n = 128) or oral dabigatran (n = 260). The mean duration of prophylaxis per patient was 46 days (6 to 168). The total cost (pay and non-pay) for prophylaxis with dalteparin was £107.54 and with dabigatran was £143.99. However, five patients in the dalteparin group required nurse administration (£23 per home visit), increasing the cost of dalteparin to £1142.54 per patient. The annual cost of VTE prophylaxis in a busy trauma clinic treating 12 700 new patients (2010/11), would be £92 526.33 in the context of an income for trauma of £1.82 million, which represents 5.3% of the outpatient tariff.

Outpatient prophylaxis in a busy trauma clinic is achievable and affordable in the context of the clinical and financial risks involved.

Cite this article: Bone Joint J 2013;95-B:673–7.

There is currently limited information available on the benefits and risks of extended thromboprophylaxis after hip fracture surgery. SAVE-HIP3 was a randomised, double-blind study conducted to evaluate the efficacy and safety of extended thromboprophylaxis with the ultra-low molecular-weight heparin semuloparin compared with placebo in patients undergoing hip fracture surgery. After a seven- to ten-day open-label run-in phase with semuloparin (20 mg once daily subcutaneously, initiated post-operatively), patients were randomised to once-daily semuloparin (20 mg subcutaneously) or placebo for 19 to 23 additional days. The primary efficacy endpoint was a composite of any venous thromboembolism (VTE; any deep-vein thrombosis and non-fatal pulmonary embolism) or all-cause death until day 24 of the double-blind period. Safety parameters included major and clinically relevant non-major bleeding, laboratory data, and treatment-emergent adverse events (TEAEs). Extended thromboprophylaxis with semuloparin demonstrated a relative risk reduction of 79% in the rate of any VTE or all-cause death compared with placebo (3.9% vs 18.6%, respectively; odds ratio 0.18 (95% confidence interval 0.07 to 0.45), p < 0.001). Two patients in the semuloparin group and none in the placebo group experienced clinically relevant bleeding. TEAE rates were similar in both groups. In conclusion, the SAVE-HIP3 study results demonstrate that patients undergoing hip fracture surgery benefit from extended thromboprophylaxis.

Cite this article: Bone Joint J 2013;95-B:459–66.