Aim

Analysis of microbiological spectrum and resistance patterns as well as the clinical outcome of patients who underwent a Debridement, antibiotics and implant retention (DAIR) procedure in the early phase following failed two-stage exchange arthroplasty of the knee and hip.

The 3D interplay between femoral component placement on contact stresses and range of motion of hip resurfacing was investigated with a hip model. Pre- and post-operative contours of the bone geometry and the gluteus medius were obtained from grey-value CT-segmentations. The joint contact forces and stresses were simulated for variations in component placement during a normal gait. The effect of component placement on range of motion was determined with a collision model. The contact forces were not increased with optimal component placement due to the compensatory effect of the medialisation of the center of rotation. However, the total range of motion decreased by 33%. Accumulative displacements of the femoral and acetabular center of rotation could increase the contact stresses between 5–24%. Inclining and anteverting the socket further increased the contact stresses between 6–11%. Increased socket inclination and anteversion in combination with shortening of the neck were associated with extremely high contact stresses. The effect of femoral offset restoration on range of motion was significantly higher than the effect of socket positioning. In conclusion, displacement of the femoral center of rotation in the lateral direction is at least as important for failure of hip resurfacings as socket malpositioning.

Introduction

Wear of the ultra high molecular weight polyethylene (UHMWPE) cup and the resulting loosening has been shown to limit the long-term results of the Charnley low-frictional torque arthroplasty (LFA). Factors affecting wear rates have been studied: level of patient activity, effective roughness of the stainless steel head, impingement and the possible variations in wear characteristics of UHMWPE. Since patients' activity level cannot be predicted or modified, alternative materials were examined.

Orthopaedic cobalt chromium particles and ions can induce indirect DNA damage and chromosome aberrations in human cells on the other side of a cellular barrier in tissue culture. This occurs by intercellular signalling across the barrier. We now show that the threshold for this effect depends on the metal form and the particle composition.

Ionic cobalt and chromium induced single strand breaks at concentrations equivalent to those found in the blood of patients with well functioning metal on metal hip prostheses. However, they only caused double strand breaks if the chromium was present as chromium (VI), and did not induce chromosome aberrations. Nanoparticles of cobalt chromium alloy caused DNA double strand breaks and chromosome aberrations, of which the majority were tetraploidy. Ceramic nanoparticles induced only single strand breaks and/or alkaline labile sites when indirectly exposed to human fibroblasts.

The assessment of reproductive risk from maternal exposure to biomaterials, especially those liberated by orthopaedic implants, is not yet possible with epidemiology. Whilst the barrier model used here differs from the in vivo situation in several respects, it may be useful as a framework to evaluate biomaterial induced damage across physiological barriers.

Purpose:. The purpose of this study was to evaluate the results of two stage reconstruction for infected arthroplasty of hip joint and to know the risk factor for failures. Patients and Methods:. From May 2004 to September 2011, 104 consecutive patients (105 hips) who underwent two stage reconstruction for the infected arthroplasty of hip joint were retrospectively evaluated. There were 60 hips with primary THA infection (Acute infection 22, Delayed infection 38), 4 hips with revision THA infection (Acute infection 1, Delayed infection 3), 20 hips with primary hemiarthroplasty infection (Acute infection 14, Delayed infection 6) and 24 hips with acute pyogenic coxitis. We evaluated the number of surgeries before two-stage reconstruction and also analysed the cultured pathogens. Mean follow duration after 2. nd. stage revision THA was 1.80 ± 1.76 years and average age at the time of 1. st. stage surgery (Debridement and PROSTALAC insertion) was 62.8 ± 14.3 years. Results:. Among 104 hips, there were 19 hips (18.3%) with uncontrolled infection after 1. st. stage surgery. In the other 85 hips, there were 8 hips (9.41%) with re-infection after 2. nd. stage revision THA. Among 104 hips, identification of the pathogens was possible in 83 hips.(MRSA 22 hips, MRSE-4 hips, MSSA-23 hips, Pseudomonas-3 hips, Tuberculous-2 hips, Enterococcus-7 hips, Candida-3 hips). The most important risk factors for failure were the number of surgeries prior to two stage reconstruction, revision THA and age. Comorbidity, BMI, Sex showed no significant increase for re-infection. There was no difference after primary THA and hemiarthroplasty. Conclusions:. Two stage reconstruction for infected arthroplasty of hip joint was a useful method for eradication of infection. In the treatment of infected hip arthroplasty, failed simple debridement can be a risk factor of re-infection after revision THA

Introduction

Failure of intertrochanteric fracture fixation often occurs in patients, who have poor bone quality, severe osteoporosis, or unstable fracture patterns. Hip arthroplasty is a good replacement procedure even though it involves technical issues such as implant removal, bone loss, poor bone quality, trochanteric nonunion and difficulty of surgical exposure. The purpose of this study is to evaluate the outcomes of total hip arthroplasty (THA) as the replacement for failed fixation of intertrochanteric fractures of the femur.

Introduction

Hip Resurfacing has been shown to be a valuable treatment for younger osteoarthritis patients related to functional outcomes. On the other hand, there is a higher risk for potential neck fractures and there is serious concern over metal-ion release and related health risks associated with the current metal-on-metal designs. Neck-preserving, short-stem implants may be a good alternative for younger patients. The current study investigated patient-reported outcomes from resurfacing and total hip arthroplasty (THA) with a neck preserving, short-stem implant (Corin MiniHip®).

Aim

Infection is one of the worst complications following total joint arthroplasty, which is often associated with significant morbidity and increased medical costs. Although Gram–positive bacteria remains the most prevalent causative agents, an increase in prosthetic joint infections (PJI) due to gram-negative bacteria (GNB) has been reported. Additionally, the emergence of multidrug resistant resistance (MDR) in GNB impacts the therapeutic options and may increase the rate of treatment failure and drug toxicity adverse effects due the prescription of harmful and toxics antimicrobial schemes. The purpose of the present study was to describe the predisposing factors associated to PJI caused by MDR-GNB in a specialized orthopedic reference hospital in Brazil from 2014 through 2018.

INTRODUCTION

A recent PRCT failed to demonstrate superiority of HRA over THA at low speeds. Having seen HRA walk much faster, we wondered if faster walking speed might reveal larger differences.

We therefore asked two simple questions:

Does fast or uphill walking have an effect on the observed difference in gait between limbs implanted with one HRA and one THA?

If there is a difference in gait between HRA and THA implanted legs, which is more normal?

Aim. Aim was to compare revision rates when using single versus dual antibiotic loaded cement (ABLC) in hip fracture arthroplasty and aseptic revision hip or knee arthroplasty using data from the Dutch national joint registry (LROI). Methods. All primary cemented (hemi-)arthroplasties for acute hip fractures and cemented aseptic hip or knee revision arthroplasties, were incorporated in 3 datasets. All registered implants between 2007 and 2018 were included (minimum 2 years follow-up). Primary end-point was subsequent revision rates for infection and for any reason in the single and dual ABLC groups. Cumulative crude incidence of revision was calculated using competing risk analysis. Results. A total of 22,308 hip fracture arthroplasties, 2,529 hip revision and 7,124 knee revision arthroplasties were registered and analyzed in the study period. The majority of hip fracture patients (97.1%) was treated with single ABLC. For hip and knee revision arthroplasties dual ABLC was used in 33.8% and 25.7%. The revision rate for infection in the fracture arthroplasty group was not different between groups (0.5% versus 0.8%, p=0.27). The re-revision rate following hip or knee revision based on single versus dual ABLC was not different between groups (3.2% versus 2.8%, p=0.82 for hip revision and 1.8% versus 2.5%, p=0.36 for knee revision). In addition, the re-revision rate for any reason was not different in all three datasets. The crude cumulative revision and re-revision rates for any reason based on single ABLC versus dual ABLC showed no differences in all three datasets. The crude cumulative 7-year re-revision rate for any reason following revision THA with Gentamicin ABLC use was 11.8%, with Gentamicin + Clindamycin ABLC use 13.1% and with Erythromycin + Colistin ABLC use 14.8% (ns). The crude cumulative 9-year re-revision rate for any reason following revision TKA with Gentamicin ABLC use was 17.7% and with Gentamicin + Clindamycin ABLC use 16.5% (ns). Conclusions. In conclusion, we could not show a difference in revision rate for hip fracture arthroplasty or re-revision rates for revision hip- or knee arthroplasty with the use of dual ABLC compared to single ABLC bone cement, with 7and 9 year follow up. The low percentage of dual ABLC in hip fracture arthroplasties in our registry do not enable us to make a reliable estimation of the added value in this patient category. The results of this study do not confirm the potential benefit of dual ABLC use in revision cases

Aim. Due to medical and organizational factors, it occurs in everyday practice that spacers are left in place longer than originally planned during a two-stage prosthesis exchange in the case of prosthetic joint infections. Patients are severely restricted in their mobility and, after initial antibiotic administration, the spacer itself only acts as a foreign body. The aim of this study is to analyze whether the duration of the spacer in situ has an influence on the long-term success of treatment and mortality. Method. We retrospectively studied all 204 two-stage prosthesis replacements of the hip and knee from 2012 to 2016 with a minimum follow-up of two years at an arthroplasty center with 3 main surgeons. The duration of the spacer interval was divided into two groups. Patients replanted within ten weeks (as is standard in multiple algorithms) after systemic antibiotic treatment were assigned to the ‘Regular Spacer Interval (< 70 days)’ group. If the spacer interval was longer, they were assigned to the ‘Long Spacer Interval (≥ 70 days)’ group. Results. Patients were on average 67.69 years old (SD 12.3). The mean duration of the spacer-interval was 100.9 days (range: 423.0; SD, 60.0). In 62 patients reimplantation could be performed within 70 days after explantation, in 142 patients this took longer (max. 438 days). In 26 patients, the spacer had to be changed at least once during this period (11 patients in the hip group, and 15 patients in the knee group). In the remaining cases, other medical or organizational reasons delayed replantation. Both groups were comparable concerning Charlson Comorbity Index, age, number of previous surgeries and laboratory infection markers. There was no statistically significant influence of the duration of the spacer interval on the infection free survival (n=204, p=0.32). There was also no influence on mortality (n=204, p=0.35) and aseptic implant failure (n=204, p=0.15). Conclusions. The timely replantation of a knee or hip prosthesis seems to be reasonable in general because the patients are strongly limited in their mobility and daily activities by the spacer. However, there does not seem to be a negative influence on infection eradication and survival due to a long spacer interval

Recent advances in arthroplasty for the hip and the knee have motivated modern foot and ankle research to perfect the implant and technique for the optimal total ankle replacement. Unlike in the hip where different approaches can be done with similar implants, the approach of a total ankle is intimately associated to the prosthetic design. The anterior and lateral approaches have pros and cons regarding their respective soft tissue complications, osteotomy necessity, orientation of the bone cut and gutter visualization. While both have been studied independently, very few reports have compared both in the same setting. This study retrospectively looked at the difference in reoperations rate after each ankle arthroplasty within two years estimating that both had similar rate of return to the operating room. A retrospective study was conducted from a single center between 2014 and 2017 including a total of 115 total ankles performed by one of four fellowship-trained foot and ankle surgeon. Re-operations were reported in the charts as an operative report. The index approach used was determined by the surgeon's practice preference. Patients were included when they had a primary TAR in the timeframe noted and had a complete dataset up to at least the two-year data. This cohort comprised 67 anterior and 48 lateral with balanced demographic for age (95%CI 63–67 yo) and gender (47% F). The lateral group had more complex cases with higher COFAS type arthritis. Comparing the two groups, a total of 40 reoperations (7 anterior, 33 lateral) occurred in 27 patients (5A, 22L). One patient had up to four related reoperations. The only revision was in the anterior group. The only soft tissue reconstruction was an STSG in the lateral group. Nine reoperations were irrigation debridement related to an infective process (3 A, 6L). The majority (19/33) of reoperations in the lateral group were gutter debridement (8) or lateral hardware removal (11). Operative time was not statistically different. The odds ratio of having a reoperation with a laterally based TAR was 6.19 compared to the anterior group. This retrospective study outlines the intermediate results at two years of lateral and anterior total ankle replacements. This is a first study of this kind in the literature. This study did show that there were more reoperations after a laterally-based TAR than an anterior TAR, recognizing the significant case complexity imbalance between groups. This speaks to the relative increase resource utilization of laterally based TAR patients. Both implant designs carry different reoperation rates favoring the anterior group however larger prospective datasets will be needed with patient-reported outcome

Aims

This study aimed to investigate the risk of postoperative complications in COVID-19-positive patients undergoing common orthopaedic procedures.

There has been a reluctance, until relatively recently, to consider replacement of the hip in patients with substantial neuromuscular imbalance. This relates to many factors, including the young age of many (such as cerebral palsy in the older teen and young adult), developmental anatomic abnormality, oft-present poor bone health, neuromuscular imbalance, and the risk of complication; especially dislocation. Mental retardation also introduces challenges with rehabilitation and an increased burden on the family and societal support systems if the outcome is to be maximised. With the development of newer techniques and technology, and the emergence of encouraging outcome studies, these patients can be more easily offered predictable relief of pain, a reasonable chance of improved function, longevity of the reconstruction, and an acceptable risk of complication. A large number of background neurological diagnoses can lead to hip degeneration, or can introduce increased complexity during management of hip degeneration unrelated to that background. Be that as it may, a short list of fundamental questions is common to all and will help guide management:. Important questions to be addressed include:. 1. Did the NV imbalance precede skeletal development? This relates to the dependence of skeletal shape and size on the loads being placed upon it: hence “Form Follows Function”. The shape and size of the hip, and location of the femoral head, will be much different in the young adult with spastic dislocation due to cerebral palsy, when compared with the elderly adult with a late onset CVA-related spasticity superimposed on hip degeneration. 2. Is the muscle tone which will support the hip arthroplasty predominantly spastic or flaccid? In each there is a risk of dislocation, which needs to be addressed at the index procedure, but in spasticity there is the added question as to what tissues need to be released or de-functioned so as to alter the magnitude and direction of the joint reaction forces. 3. Is pain the main reason for consultation? Because pain relief is the most predictable outcome that we can offer, it should guide the indications and timing of intervention. Replacement of the NM hip to improve function, in the absence of pain, should be approached with great caution

Aim. Patients use antibiotics for various reasons before elective joint replacement surgery, but it is not known how common this is. The aim of this study was to investigate patients' use of oral antibiotics before elective joint replacement surgery and how this affects the risk for periprosthetic joint infection (PJI) in a one-year follow-up. Method. Patients with a primary hip or knee replacement performed in a tertiary care hospital between September 2002 and December 2013 were identified (23 171 joint replacements, 10 200 hips and 12 971 knees). Information on oral antibiotics purchased within 90 days before the operation was gathered from a national database. The occurrence of a PJI, identified by prospective infection surveillance, in a one-year follow-up was the primary outcome. The occurrence of any surgical site infection was analyzed as a secondary outcome. The association between antibiotic use and subsequent infection was examined using a multivariable logistic regression model that included information on the operated joint, age, gender, body mass index and patients' chronic diseases (according to medication data). Results. During the one-year follow-up, 158 (0.68%) PJIs were identified. 4 106 (18%) of the joint replacement operations were preceded by one or more courses of oral antibiotics. The most commonly prescribed group of antibiotics was 1st generation cephalosporins. The incidence of PJI for patients with preoperative oral antibiotic use was 0.29% (12/4 106), compared to 0.77% (146/19 065) in patients without preoperative antibiotics. A preoperative oral antibiotic course decreased the risk for subsequent PJI both in the univariate (OR 0.38, 95% CI 0.21 – 0.69) and multivariable model (OR 0.40, 95% CI 0.22–0.73). When superficial infection cases were included in the analysis, preoperative antibiotic use did not affect the overall risk for surgical site infection. Conclusions. The use of oral antibiotics before elective joint replacement surgery is common and is associated with a lower risk for subsequent PJI. Further studies are needed in order to confirm this finding and to evaluate factors affecting this result. Meanwhile, the indiscriminate use of antibiotics before elective joint replacement surgery cannot be recommended, even though the treatment of active infections remains important in the prevention of surgical site infections

Aim. Prosthetic joint infections (PJI) are devastating complications after hip arthroplasty and infection rates varies internationally between 0.76% to 1.24%. Hemi-arthroplasty (HA) is the gold standard treatment for dislocated femoral neck fractures. Recently, total hip arthroplasty (THA) has been suggested to generate even better outcomes. However, little is known about PJIs after hip fractures. The purpose of this study was to investigate PJIs after femoral neck fracture in a population-based sample. Methods. Clinical databases were harvested for all THA or HA procedures done for the treatment of femoral neck fractures at our hospital district (HUS) of 1.6 million inhabitants. Altogether, 3693 arthroplasty procedures for hip fractures were performed between 2011 to 2015. The original patient records of each case were reviewed. Complication(s) leading to readmission(s), the microbe(s), and the treatment protocol of each infection was recorded until the closing date (31.12.2016). The definition of PJI according to Musculosceletal Infection Society modified at the International Consensus meeting was used. Results. We detected 111 infections (10 THAs;101 HAs):42 superficial infections (1.1%) and 69 PJIs (1.9%). The PJI rate after THA was 3.7% (8/219) and 1.8% after HA (61/3474) (p=0.04;OR 2.12, 95%CI 1.00–4.49). Most PJIs in THA group (6/8) were treated by debridement, antimicrobials, and implant retention (DAIR) and two by 2-stage exchange. In the HA group the DAIR was the first surgical treatment for 51 PJIs (84%). Other treatment options used were girdlestone (n=3), one-stage exchange (n=2), lavation (n=2), and conservative treatment (n=3). The bacteria cultured at THA group were: Staphylococcus epidermidis (n=4), Staphylococcus aureus (n=3), Streptococcus agalactiae (n=2), and Staphylococcus haemolyticus and at the HA group Staphylococcus aureus (n=25, including 1 MRSA), Staphylococcus epidermidis (n=11), other coagulase negative staphylococci (n=7), Pseudomonas aeruginosa (n=6), Enterococcus faecalis (n=6), Escherichia coli (n=2), and streptococci (n=2). Multiple bacteria were cultured from seven PJIs. The causative microbe was unknown in five PJIs. Conclusion. THA patients had higher rate of PJIs compared to HA, however, the small sample size of the THA group may limit the statistical power of this study. The PJIs after hip fractures were usually treated by DAIR, which is also main PJI treatment after elective THAs. The overall PJI rate was higher among hip fracture than after elective THAs in the literature. The existing trend of treating more dislocated hip fractures with THA may thus lead to increased rated of PJIs in the future

Aims

The aim of this study was to analyze the prevalence of culture-negative periprosthetic joint infections (PJIs) when adequate methods of culture are used, and to evaluate the outcome in patients who were treated with antibiotics for a culture-negative PJI compared with those in whom antibiotics were withheld.

Aims. The aim of this paper was to present the clinical features of patients with musculoskeletal sources of methicillin-sensitive Staphylococcus aureus (MSSA) septicaemia. Patients and Methods. A total of 137 patients presented with MSSA septicaemia between 2012 and 2015. The primary source of infection was musculoskeletal in 48 patients (35%). Musculoskeletal infection was considered the primary source of septicaemia when endocarditis and other obvious sources were excluded. All patients with an arthroplasty at the time were evaluated for any prosthetic involvement. . Results. The most common site of infection was the spine, which occurred in 28 patients (58%), and was associated with abscess formation in 16. Back pain was the presenting symptom in these patients, with a positive predictive value of 100%. A total of 24 patients had a total of 42 arthroplasties of the hip or knee in situ. Prosthetic joint infection occurred in six of these patients (25%). In five patients, the infection originated outside the musculoskeletal system. Three patients (6%) with MSSA septicaemia from a musculoskeletal sources died. . Conclusion. Amongst the musculoskeletal sources of MSSA septicaemia, the spine was the most commonly involved. We recommend an MRI scan of the whole spine and pelvis in patients with MSSA septicaemia with back pain, when the primary source of infection has not been identified or clinical examination is unreliable. Cite this article: Bone Joint J 2017;99-B:1545–51

There are several clinical scenarios to consider cementing an acetabular liner into a secure cementless shell including cases of: 1) inadequate capturing mechanism, 2) damaged locking mechanisms, 3) unavailability of the mating polyethylene liner, 4) instability following debridement for wear, 5) instability at the time of femoral side revision, and 6) recurrent dislocation. The last two situations are common scenarios for cementing a constrained liner into a secure shell. Technique includes: 1) scoring the shell in cases with no screw holes or polished inner shells, 2) scoring the acetabular liner in a “spider web” pattern, 3) pressurizing cement into the shell, and 4) inserting a liner that allows 2mm of cement mantle. Results of Cementing Constrained Liner Into Secure Cementless Shell: Callaghan et al. JBJS 2004. Thirty-one hips at 2–10 year follow-up. Two of 31 failed. Technical considerations: do not cement proud and do not cement into a malpositioned shell; Haft et al. J Arthroplasty 2002. Seventeen hips with minimum 1 year follow-up. One of 17 failed. Technical considerations: do not cement proud. Results of Cementing Non-Constrained Liners Into Secure Cementless Shell: Beaule et al. JBJS 2004. Thirty-two hips at mean 5.1 year avg f/u. Four components revised for loosening; Callaghan et al. CORR 2012. Thirty-one hips at mean 5.3 year f/u. No revisions

Introduction. seeking full compliance with the Tissue Sparing Surgery principles, we introduced this new surgical approach to the coxa-femoral joint via the medial inguinal region. Method. we performed total hip arthroplasty on 20 patients suffering from hip arthritis while 15 cases of medial femoral fracture received hemiarthroplasty with bipolar prostheses implants. Outcome. reduced surgery times, lower blood loss, zero complications and significantly speedier recovery were observedin all the above cases. Argument. this new surgical approach we devised enables a quick, safe and easy replacement of the hip. The muscles of the hip remain totally unharmed; maximum exposure is gained, with visualization of the acetabulum, directly fronting the surgeon, at its very best, favourably comparing with any other known approach. No particular equipment is needed and no special operating table. And it does not in the least imply a steep learning curve. Dislocation risks are non-existent allowing the patient any position in bed immediately after surgery. It is aesthetically preferable, the scar remaining almost invisible in between the inguinal skin lines. The patient can at once resume a steady walk, Canadian crutches being needed only for the first few days. Conclusion. it is the authors' opinion that such a technique, thanks to its being safe, fast, economical and easy to replicate, results in undoubted benefits for the patient, not least because it requires much shorter and far easier rehabilitation; and it can be counted as a valid alternative for surgeons to the most common approaches currently in use