Isolated wear of the polyethylene tibial component led to failure in five of a series of 108 uncemented porous-coated knee replacements. The clinical features included pain, effusion and instability with progressive varus deformity. In all cases there was extensive wear on the medial side of the polyethylene surface of the prosthesis. The mechanism of such wear is complex, being due in part to the unconstrained nature of the joint and the incongruity of its surfaces. Other design characteristics may have contributed

In a prospective study of 100 knee arthroplasties in patients with rheumatoid arthritis, simultaneous bilateral surgery was compared with staged bilateral replacements. All patients had improved function following their operations but those who had staged surgery only achieved maximum benefit after the second knee had been replaced. The complication rate was no greater for simultaneous surgery and we therefore advocate the method for those patients who require bilateral replacements

In a consecutive series of 87 operations for knee replacement prospective observations were made of the pattern of articular destruction in the form of a triangle of erosion or osteophyte formation, which is seen on the medial femoral condyle, sometimes with an associated strip on the lateral femoral condyle. These areas represent the surfaces which are normally in contact with the anterior horns of the menisci when the knee is fully extended. The lesions in question were found only in association with a flexion contracture in 84 out of the 87 cases

Antibiotic levels in bone and fat were measured in patients undergoing knee replacement to determine the time that should elapse between intravenous injection and tourniquet inflation. The tissue levels increased progressively with time, and there was wide variation in absorption rate between patients and between the two cephalosporins assessed. Five minutes should probably be left between systemic injection and inflation of the tourniquet, though two minutes may be long enough for drugs which are rapidly absorbed

We analysed the long-term results with a mean follow-up of 10.2 years, of 66 total knee replacements in 42 patients with rheumatoid arthritis. In all cases the posterior cruciate ligament was retained. There were only three complications (4.5%). Revision surgery was necessary in five knees (7.6%), including one (1.5%) with infection. At the final follow-up, 75.8% of knees were rated excellent clinically. Only 15% had an excellent function score. The survival rate of the implant was 90.7% at 19 years. The clinical, radiological and survivorship analysis shows that the posterior-cruciate-retaining knee arthroplasty performs well in rheumatoid arthritis

Objectives

Unicompartmental knee arthroplasty (UKA) is an alternative to total knee arthroplasty for patients who require treatment of single-compartment osteoarthritis, especially for young patients. To satisfy this requirement, new patient-specific prosthetic designs have been introduced. The patient-specific UKA is designed on the basis of data from preoperative medical images. In general, knee implant design with increased conformity has been developed to provide lower contact stress and reduced wear on the tibial insert compared with flat knee designs. The different tibiofemoral conformity may provide designers the opportunity to address both wear and kinematic design goals simultaneously. The aim of this study was to evaluate wear prediction with respect to tibiofemoral conformity design in patient-specific UKA under gait loading conditions by using a previously validated computational wear method.

Aims

This aim of this study was to assess the feasibility of designing and introducing generic 3D-printed instrumentation for routine use in total knee arthroplasty.

Objectives

Prosthetic joint infection (PJI) is the most common cause of arthroplasty failure. However, infection is often difficult to detect by conventional bacterial cultures, for which false-negative rates are 23% to 35%. In contrast, 16S rRNA metagenomics has been shown to quantitatively detect unculturable, unsuspected, and unviable pathogens. In this study, we investigated the use of 16S rRNA metagenomics for detection of bacterial pathogens in synovial fluid (SF) from patients with hip or knee PJI.

The St Georg modular knee replacement has been studied in 59 cases with an observation period ranging from 28 to 73 months. In 47% of the knees both compartments were replaced; five of the six poor results were in this group. These were revised to a hinge arthroplasty or, in one case, to an arthrodesis. Other complications were few and insignificant. There were no infections. We concluded that unicompartmental knee arthroplasty can be recommended when joint involvement is localised to one compartment only. With more generalised joint disease we prefer a semiconstrained total condylar prosthesis

Aims

Tranexamic acid (TXA) is proven to reduce blood loss following total knee arthroplasty (TKA), but there are limited data on the impact of similar dosing regimens in revision TKA. The purpose of this multicentre randomized clinical trial was to determine the optimal regimen to maximize the blood-sparing properties of TXA in revision TKA.

If conclusions are to be of any value they must be definite and one cannot draw definite conclusions from less than, say, fifty cases followed up for at least five years. However, few surgeons will ever see fifty patients requiring arthroplasty of the knee, let alone operate of them, even in five years. Accordingly, this account of a new approach to the problem of knee arthroplasty is submitted in the hope that other surgeons may care to try it and thereby learn, and thus be able to teach, tile modifications and improvements that all new techniques seem so surely to need

Although the incidence of infection associated with hip and knee prostheses is low, with the increasing number of arthroplasties being carried out, the total number of such cases is increasing. The pattern of infecting organisms after total joint arthroplasty has changed and gentamicin-resistant organisms are becoming increasingly common. In conjunction with surgical debridement, vancomycin added to a bone-cement carrier can be very effective in the treatment of infection caused by such organisms. We report the results of its use in proven deep infection in 26 hip and seven knee arthroplasties. After a mean follow-up of 67 months, 32 patients remained clinically and radiologically free from infection. There was one recurrence and positive second-stage cultures of uncertain significance in three other patients. Vancomycin is potentially very useful in the management of deep infection after arthroplasty

Aims

Psychological factors play a critical role in patient presentation, satisfaction, and outcomes. Pain catastrophizing, anxiety, and depression are important to consider, as they are associated with poorer outcomes and are potentially modifiable. The aim of this study was to assess the level of pain catastrophizing, anxiety, and depression in patients with a range of hip pathology and to evaluate their relationship with patient-reported psychosocial and functional outcome measures.

We prospectively randomised 100 patients undergoing cemented total knee replacement to receive either a single deep closed-suction drain or no drain. The total blood loss was significantly greater in those with a drain (568 ml versus 119 ml, p < 0.01; 95% CI 360 to 520) although those without lost more blood into the dressings (55 ml versus 119 ml, p < 0.01; 95% CI −70 to 10). There was no statistical difference in the postoperative swelling or pain score, or in the incidence of pyrexia, ecchymosis, time at which flexion was regained or the need for manipulation, or in the incidence of infection at a minimum of five years after surgery in the two groups. We have been unable to provide evidence to support the use of a closed-suction drain in cemented knee arthroplasty. It merely interferes with mobilisation and complicates nursing. Reinfusion drains may, however, prove to be beneficial

Smoking is an important risk factor for the development of postoperative pulmonary complications after major surgical procedures. We studied 811 consecutive patients who had undergone hip or knee arthroplasty, recording current smoking and drinking habits, any history of chronic disease and such intraoperative factors as the type of anaesthesia and the type and duration of surgery. We recorded any postoperative complications occurring before discharge from hospital. There were 232 smokers (28.6%) and 579 non-smokers. We found that smoking was the single most important risk factor for the development of postoperative complications, particularly those relating to wound healing, cardiopulmonary complications, and the requirement of postoperative intensive care. A delay in discharge from hospital was usual for those suffering a complication. In those patients requiring prolonged hospitalisation (> 15 days) the proportion of smokers with wound complications was twice that of non-smokers

An intact barrier between the hands of the surgeon and the patient remains the single most important factor in protection against infection for both. Increasing the awareness of possible glove perforation without skin penetration will decrease the risk of contamination. We performed a prospective, randomised trial comparing the incidence of glove perforation using a new type of glove (Regent Biogel Reveal) and standard double-gloves in total hip and knee replacement. One or more perforations was detected in 14.6% of all gloves. The new gloves increased significantly the awareness of perforation. Multiple perforations at the base of the ring finger were found in surgeons who wore wedding rings during the operation and we recommend that rings be removed before undertaking surgery

Aims

Robotic-assisted unicompartmental knee arthroplasty (UKA) promises accurate implant placement with the potential of improved survival and functional outcomes. The aim of this study was to present the current evidence for robotic-assisted UKA and describe the outcome in terms of implant positioning, range of movement (ROM), function and survival, and the types of robot and implants that are currently used.

We performed a prospective randomised controlled trial of a new mechanical method of prophylaxis for venous thrombo-embolism in 60 patients undergoing knee replacement surgery. The method uses the A-V Impulse System to produce cyclical compression of the venous reservoir of the foot. The overall incidence of deep-vein thrombosis was 68.7% in patients receiving no prophylaxis and 50% in those using the device. The difference was not significant. There was, however, a reduction of the extent of thrombosis in the treated group. There were 13 major calf-vein thrombi and six proximal-vein thrombi in the control group compared with only five major calf-vein thrombi in the treated group. This difference was significant (p = 0.014). No patient developed clinical features of a pulmonary embolism