Aims. Surgical site infection (SSI) is a common complication of surgery with an incidence of about 1% in the United Kingdom. Sutures can lead to the development of a SSI, as micro-organisms can colonize the suture as it is implanted. Triclosan-coated sutures, being antimicrobical, were developed to reduce the rate of SSI. Our aim was to assess whether triclosan-coated sutures cause a reduction in SSIs following arthroplasty of the hip and knee. Patients and Methods. This two-arm, parallel, double-blinded study involved 2546 patients undergoing elective total hip (THA) and total knee arthroplasty (TKA) at three hospitals. A total of 1323 were quasi-randomized to a standard suture group, and 1223 being quasi-randomized to the triclosan-coated suture group. The primary endpoint was the rate of SSI at 30 days postoperatively. Results. The baseline characteristics of age, gender and comorbidities were well matched in the two groups. The rates of superficial SSI were 0.8% in the control group and 0.7% in the intervention group (p = 0.651), and when deep and superficial SSIs were combined the rates were 2.5% and 1.8 (p = 0.266). The length of stay in hospital and the rates of medical complications did not differ significantly between the groups (p = 1.000). Conclusion. This trial provided no evidence that the use of triclosan-coated sutures at THA and TKA leads to a reduction in the rate of SSI. Cite this article: Bone Joint J 2018;100-B:296–302

Aims

The purpose of this study was to compare the radiological outcomes of manual versus robotic-assisted medial unicompartmental knee arthroplasty (UKA).

Aims. Loosening of the tibial component after total knee arthroplasty (TKA) is a common indication for revision. Increasing the strength of the initial tibial implant/cement interface is desirable. There is little information about the surgical techniques that lead to the highest strength. We investigated the effects of eight variables on the strength of the initial tibial baseplate/cement interface. Materials and Methods. A total of 48 tibial trays were cemented into acrylic holders using cement from two manufacturers, at three different times (early, normal, and late) using two techniques: cementing the tibial plateau or the plateau and the keel; and involving two conditions of contamination with marrow fat (at the metal/cement and cement/cement interfaces). Push-out tests were performed with load continuously recorded. Results. Compared with normal conditions, early cementing increased the mean strength of the interface when using the two cements, Simplex and Palacos, by 48% and 72%, respectively. Late cementing reduced the strength by 47% and 73%, respectively. Cementing the keel increased the mean strength by 153% and 147%, respectively, for the two cements. Contamination of the metal/cement interface with fat reduced the mean strength by 99% and 94% for the two cements but adding cement to the underside of the tibial tray prior to insertion resulted in the mean strength being lowered by only 65% and 43%, respectively. Conclusion. In order to maximize the strength of the tibial tray/cement interface, cement should be applied to the component soon after mixing, contamination of the interface should be avoided, and the keel and the plateau should be cemented

The June 2015 Knee Roundup360 looks at: Cruciate substituting versus retaining knee replacement; What’s behind the psychology of anterior cruciate ligament (ACL) reconstruction?; Is there a difference in total knee arthroplasty risk of revision in highly crosslinked versus conventional polyethylene?; Unicompartmental knee arthroplasty: is age the missing variable?; Satisfaction rates following total knee arthroplasty; Is knee alignment dynamic?; Unicompartmental knee arthroplasty: cemented or cementless?; Can revision knee services pay?

Aims

Although there is increasing legalization of the use of cannabis in the USA, few well-powered studies have evaluated the association between cannabis use disorder and outcomes following primary total hip arthroplasty (THA). Thus, the aim of this study was to determine whether patients who use cannabis and undergo primary THA have higher rates of in-hospital length of stay (LOS), medical complications, implant-related complications, and costs.

Using the General Practice Research Database, we examined the temporal changes in the rates of primary total hip (THR) and total knee (TKR) replacement, the age at operation and the female-to-male ratio between 1991 and 2006 in the United Kingdom. We identified 27 113 patients with THR and 23 843 with TKR. The rate of performance of THR and TKR had increased significantly (p < 0.0001 for both) during the 16-year period and was greater for TKR, especially in the last five years. The mean age at operation was greater for women than for men and had remained stable throughout the period of study. The female-to-male ratio was higher for THR and TKR and had remained stable. The data support the notion that the rate of joint replacement is increasing in the United Kingdom with the rate of TKR rising at the highest rate. The perception that the mean age for TKR has decreased over time is not supported

Aims

Periprosthetic joint infections (PJIs) are among the most devastating complications after joint arthroplasty. There is limited evidence on the efficacy of different antiseptic solutions on reducing biofilm burden. The purpose of the present study was to test the efficacy of different antiseptic solutions against clinically relevant microorganisms in biofilm.

Patient specific instrumentation (PSI) uses advanced imaging of the knee (CT or MRI) to generate individualised cutting blocks aimed to make the procedure of total knee arthroplasty (TKA) more accurate and efficient. However, in this era of healthcare cost consciousness, the value of new technologies needs to be critically evaluated. There have been several comparative studies looking at PSI versus standard instrumentation. Most compare PSI with conventional instrumentation in terms of alignment in the coronal plane, operative time and surgical efficiency, cost effectiveness and short-term outcomes. Several systematic reviews and meta-analyses have also been published. PSI has not been shown to be superior compared with conventional instrumentation in its ability to restore traditional mechanical alignment in primary TKA. Most studies show comparative efficacy and no decrease in the number of outliers in either group. In terms of operative time and efficiency, PSI tended towards decreasing operative time, saving a mean of five minutes per patient (0 to 20). Furthermore, while some cost savings could be realised with less operative time and reduced instrumentation per patient, these savings were overcome by the cost of the CT/MRI and the cutting blocks. Finally, there was no evidence that PSI positively affected clinical outcomes at two days, two months, or two years. Consequently, current evidence does not support routine use of PSI in routine primary TKA. Cite this article: Bone Joint J 2016;98-B(1 Suppl A):78–80

The aim of this study was to perform a cost–utility analysis of total hip (THR) and knee replacement (TKR). Arthritis is a disabling condition that leads to long-term deterioration in quality of life. Total joint replacement, despite being one of the greatest advances in medicine of the modern era, has recently come under scrutiny. The National Health Service (NHS) has competing demands, and resource allocation is challenging in times of economic restraint. Patients who underwent THR (n = 348) or TKR (n = 323) between January and July 2010 in one Scottish region were entered into a prospective arthroplasty database. A health–utility score was derived from the EuroQol (EQ-5D) score pre-operatively and at one year, and was combined with individual life expectancy to derive the quality-adjusted life years (QALYs) gained. Two-way analysis of variance was used to compare QALYs gained between procedures, while controlling for baseline differences. The number of QALYs gained was higher after THR than after TKR (6.5 vs 4.0 years, p < 0.001). The cost per QALY for THR was £1372 compared with £2101 for TKR. The predictors of an increase in QALYs gained were poorer health before surgery (p < 0.001) and younger age (p < 0.001). General health (EQ-5D VAS) showed greater improvement after THR than after TKR (p < 0.001). This study provides up-to-date cost-effectiveness data for total joint replacement. THR and TKR are extremely effective both clinically and in terms of cost effectiveness, with costs that compare favourably to those of other medical interventions. Cite this article: Bone Joint J 2013;95-B:115–21

Aims

There is a paucity of long-term studies analyzing risk factors for failure after single-stage revision for periprosthetic joint infection (PJI) following total hip arthroplasty (THA). We report the mid- to long-term septic and non-septic failure rate of single-stage revision for PJI after THA.

Aims

Recent improvements in surgical technique and perioperative blood management after total joint replacement (TJR) have decreased rates of transfusion. However, as many surgeons transition to outpatient TJR, obtaining routine postoperative blood tests becomes more challenging. Therefore, we sought to determine if a preoperative outpatient assessment tool that stratifies patients based on numerous medical comorbidities could predict who required postoperative haemoglobin (Hb) measurement.

High-flexion total knee replacement (TKR) designs have been introduced to improve flexion after TKR. Although the early results of such designs were promising, recent literature has raised concerns about the incidence of early loosening of the femoral component. We compared the minimum force required to cause femoral component loosening for six high-flexion and six conventional TKR designs in a laboratory experiment. Each TKR design was implanted in a femoral bone model and placed in a loading frame in 135° of flexion. Loosening of the femoral component was induced by moving the tibial component at a constant rate of displacement while maintaining the same angle of flexion. A stereophotogrammetric system registered the relative movement between the femoral component and the underlying bone until loosening occurred. Compared with high-flexion designs, conventional TKR designs required a significantly higher force before loosening occurred (p < 0.001). High-flexion designs with closed box geometry required significantly higher loosening forces than high-flexion designs with open box geometry (p = 0.0478). The presence of pegs further contributed to the fixation strength of components. We conclude that high-flexion designs have a greater risk for femoral component loosening than conventional TKR designs. We believe this is attributable to the absence of femoral load sharing between the prosthetic component and the condylar bone during flexion

The management of nonunion following high tibial osteotomy by total knee replacement (TKR) has been reported previously. We have extended the treatment to embrace cases with an infected high tibial osteotomy by performing an initial debridement with a period of antibiotic treatment followed by TKR. We have reviewed the results of seven knees in six patients with a mean follow-up of 40.5 months (20 to 57) after the staged TKR. At the latest follow-up, all the pseudarthroses had healed and there had been no recurrence of infection. The mean Hospital for Special Surgery knee score improved from 51.2 (35 to 73) to a mean of 91.7 (84 to 98) at final review. Management of nonunion following high tibial osteotomy with a TKR can be extended to infected cases when treated in two stages with a debridement and antibiotic therapy prior to TKR

Objectives. Posterior condylar offset (PCO) and posterior tibial slope (PTS) are critical factors in total knee arthroplasty (TKA). A computational simulation was performed to evaluate the biomechanical effect of PCO and PTS on cruciate retaining TKA. Methods. We generated a subject-specific computational model followed by the development of ± 1 mm, ± 2 mm and ± 3 mm PCO models in the posterior direction, and -3°, 0°, 3° and 6° PTS models with each of the PCO models. Using a validated finite element (FE) model, we investigated the influence of the changes in PCO and PTS on the contact stress in the patellar button and the forces on the posterior cruciate ligament (PCL), patellar tendon and quadriceps muscles under the deep knee-bend loading conditions. Results. Contact stress on the patellar button increased and decreased as PCO translated to the anterior and posterior directions, respectively. In addition, contact stress on the patellar button decreased as PTS increased. These trends were consistent in the FE models with altered PCO. Higher quadriceps muscle and patellar tendon force are required as PCO translated in the anterior direction with an equivalent flexion angle. However, as PTS increased, quadriceps muscle and patellar tendon force reduced in each PCO condition. The forces exerted on the PCL increased as PCO translated to the posterior direction and decreased as PTS increased. Conclusion. The change in PCO alternatively provided positive and negative biomechanical effects, but it led to a reduction in a negative biomechanical effect as PTS increased. Cite this article: K-T. Kang, Y-G. Koh, J. Son, O-R. Kwon, J-S. Lee, S. K. Kwon. A computational simulation study to determine the biomechanical influence of posterior condylar offset and tibial slope in cruciate retaining total knee arthroplasty. Bone Joint Res 2018;7:69–78. DOI: 10.1302/2046-3758.71.BJR-2017-0143.R1

We hypothesised there was no clinical value in using an autologous blood transfusion (ABT) drain in either primary total hip (THR) or total knee replacement (TKR) in terms of limiting allogeneic blood transfusions when a modern restrictive blood management regime was followed. A total of 575 patients (65.2% men), with a mean age of 68.9 years (36 to 94) were randomised in this three-arm study to no drainage (group A), or to wound drainage with an ABT drain for either six hours (group B) or 24 hours (group C). The primary outcome was the number of patients receiving allogeneic blood transfusion. Secondary outcomes were post-operative haemoglobin (Hb) levels, length of hospital stay and adverse events. This study identified only 41 transfused patients, with no significant difference in distribution between the three groups (p = 0.857). The mean pre-operative haemoglobin (Hb) value in the transfused group was 12.8 g/dL (9.8 to 15.5) versus 14.3 g/dL (10.6 to 18.0) in the non-transfused group (p < 0.001, 95% confidence interval: 1.08 to 1.86). Post-operatively, the median of re-transfused shed blood in patients with a THR was 280 mL (Interquartile range (IQR) 150 to 400) and in TKR patients 500 mL (IQR 350 to 650) (p <  0.001). ABT drains had no effect on the proportion of transfused patients in primary THR and TKR. The secondary outcomes were also comparable between groups. Cite this article: Bone Joint J 2014;96-B:765–71

Haematomas, drainage, and other non-infectious wound complications following total knee replacement (TKR) have been associated with long-term sequelae, in particular, deep infection. However, the impact of these wound complications on clinical outcome is unknown. This study compares results in 15 patients re-admitted for wound complications within 90 days of TKR to 30 matched patients who underwent uncomplicated total knee replacements. Patients with wound complications had a mean age of 66 years (49 to 83) and mean body mass index (BMI) of 37 (21 to 54), both similar to that of patients without complications (mean age 65 years and mean BMI 35). Those with complications had lower mean Knee Society function scores (46 (0 to 100 vs 66 (20 to 100), p = 0.047) and a higher incidence of mild or greater pain (73% vs 33%, p = 0.01) after two years compared with the non re-admitted group. Expectations in patients with wound complications following TKR should be tempered, even in those who do not develop an infection. Cite this article: Bone Joint J 2014;96-B:619–21

Aim

There is insufficient evidence to support bony reconstruction of the pubis after a type III internal hemipelvectomy (resection of all or part of the pubis). In this study, we compared surgical complications, postoperative pain, and functional outcome in a series of patients who had undergone a type III internal hemipelvectomy with or without bony reconstruction.