Aims

The prevalence of obesity is increasing substantially around the world. Elevated BMI increases the risk of complications following total hip arthroplasty (THA). We sought to evaluate trends in BMI and complication rates of obese patients undergoing primary THA over the last 30 years.

Aims

In metal-on-metal (MoM) hip arthroplasties and resurfacings, mechanically induced corrosion can lead to elevated serum metal ions, a local inflammatory response, and formation of pseudotumours, ultimately requiring revision. The size and diametral clearance of anatomical (ADM) and modular (MDM) dual-mobility polyethylene bearings match those of Birmingham hip MoM components. If the acetabular component is satisfactorily positioned, well integrated into the bone, and has no surface damage, this presents the opportunity for revision with exchange of the metal head for ADM/MDM polyethylene bearings without removal of the acetabular component.

Aims

The Vantage Total Ankle System is a fourth-generation low-profile fixed-bearing implant that has been available since 2016. We aimed to describe our early experience with this implant.

In metal-on-metal (MoM) hip replacements or resurfacings, mechanical induced corrosion can lead to a local inflammatory response, pseudo tumours and elevated serum metal ions, requiring revision surgery.

The size and diametral clearance of Anatomic (ADM) and Modular (MDM) Dual Mobility bearings matches that of certain MOM components. Presenting the opportunity for revision with exchange of the metal head for ADM/MDM bearings without removal of the acetabular component if it is well-fixed and appropriately positioned.

Between 2012 and 2020, across two centres, 94 patients underwent revision of a MoM hip replacement or resurfacing. The mean age was 65.5 (33–87) years. In 53 patients (56.4%), the acetabular component was retained, and dual mobility bearings were used (DM); in 41 (43.6%) the acetabulum was revised (AR). DM was only considered where the acetabular component was satisfactorily positioned and well-integrated into bone, with no surface damage. Patients underwent clinical and radiographic follow-up to at least one-year (mean 42.4 (12–96) months).

One (1.1%) patient died before one-year, for reasons unrelated to the surgery. In the DM group, two (3.8%) patients underwent further surgery; one (1.9%) for dislocation and one (1.9%) for infection. In the AR group, four (12.2%) underwent further procedures; two (4.9%) for loosening of the acetabular component and two (4.9%) following dislocations. There were no other dislocations in either group. In the DM group, operative time (68.4 v 101.5 mins, p<0.001), postoperative drop in haemoglobin (16.6 v 27.8 g/L, p<0.001), and length of stay (1.8 v 2.4 days, p<0.001) were significantly lower. There was a significant reduction in serum metal ions postoperatively in both groups (p<0.001 both Cobalt and Chromium) although there was no difference between groups for this reduction (p=0.674 Cobalt; p=0.186 Chromium).

In selected patients with MoM hip arthroplasty, where the acetabular component is well-fixed, in a satisfactory position and there is no surface damage, the metal head can be exchanged for ADM/MDM bearings with retention of the acetabular prosthesis. Presenting significant benefits through a less invasive procedure, and a low risk of complications, including dislocation.

Aims

Debridement, antibiotics, and implant retention (DAIR) remains one option for the treatment of acute periprosthetic joint infection (PJI) despite imperfect success rates. Intraosseous (IO) administration of vancomycin results in significantly increased local bone and tissue concentrations compared to systemic antibiotics alone. The purpose of this study was to evaluate if the addition of a single dose of IO regional antibiotics to our protocol at the time of DAIR would improve outcomes.

Aims. To describe the risk of periprosthetic joint infection (PJI) and reoperation in patients who have an acute, traumatic wound dehiscence following total knee arthroplasty (TKA). Methods. From January 2002 to December 2018, 16,134 primary TKAs were performed at a single institution. A total of 26 patients (0.1%) had a traumatic wound dehiscence within the first 30 days. Mean age was 68 years (44 to 87), 38% (n = 10) were female, and mean BMI was 34 kg/m. 2. (23 to 48). Median time to dehiscence was 13 days (interquartile range (IQR) 4 to 15). The dehiscence resulted from a fall in 22 patients and sudden flexion after staple removal in four. The arthrotomy was also disrupted in 58% (n = 15), including a complete extensor mechanism disruption in four knees. An irrigation and debridement with component retention (IDCR) was performed within 48 hours in 19 of 26 knees and two-thirds were discharged on antibiotic therapy. The mean follow-up was six years (2 to 15). The association of wound dehiscence and the risk of developing a PJI was analyzed. Results. Patients who sustained a traumatic wound dehiscence had a 6.5-fold increase in the risk of PJI (95% confidence interval (CI) 1.6 to 26.2; p = 0.008). With the small number of PJIs, no variables were found to be significant risk factors. However, there were no PJIs in any of the patients who were treated with IDCR and a course of antibiotics. Three knees required reoperation including one two-stage exchange for PJI, one repeat IDCR for PJI, and one revision for aseptic loosening of the tibial component. Conclusion. Despite having a traumatic wound dehiscence, the risk of PJI was low, but much higher than experienced in all other TKAs during the same period. We recommend urgent IDCR and a course of postoperative antibiotics to decrease the risk of PJI. A traumatic wound dehiscence increases risk of PJI by 6.5-fold. Cite this article: Bone Joint J 2021;103-B(6 Supple A):191–195

Aims

Cementless total knee arthroplasty (TKA) offers the potential for strong biological fixation compared with cemented TKA where fixation is achieved by the mechanical integration of the cement. Few mid-term results are available for newer cementless TKA designs, which have used additive manufacturing (3D printing). The aim of this study was to present mid-term clinical outcomes and implant survivorship of the cementless Stryker Triathlon Tritanium TKA.

Background. There are limited data on the complication rates and risk of periprosthetic joint infection (PJI) in patients who have an acute wound dehiscence after total knee arthroplasty (TKA). Methods. From 2002 to 2018, 16,134 primary TKAs were performed at a single institution. Twenty-six patients (0.1%) had a traumatic wound dehiscence within the first 30 days. Mean age was 68, 38% were female, and mean BMI was 33 kg/m2. Median time to dehiscence was 13 days. The dehiscence resulted from a fall in 22 cases, including 4 in-hospital falls (3 with femoral nerve blocks), and sudden flexion after staple removal in 4 cases. The arthrotomy was disrupted in 58%, including a complete extensor mechanism disruption in 4 knees. A surgical debridement was performed within 48 hours in 19 of 26 knees. Two-thirds were discharged on antibiotic therapy. Results. Only two knees were complicated by PJI (cumulative incidence of 11% vs. 1% in all other primary TKAs, HR 6.5, p <0.01). One patient who developed a PJI was initially treated with a bedside closure in the ER rather than surgical debridement. The second patient had a complete extensor mechanism disruption at the time of dehiscence and was treated with surgical debridement, but did not receive a subsequent course of antibiotics. There were no PJIs in any of the cases that were treated with surgical debridement and a course of antibiotics. Three knees required reoperation (cumulative incidence of reoperation was 16% at 2 years, compared to 6% in all other primary TKAs, p=0.32) including 1 two-stage exchange for PJI, 1 irrigation and debridement with component retention for PJI, and 1 revision for tibial component aseptic loosening. Conclusion. Despite having a traumatic wound dehiscence, with nearly 60% resulting in arthrotomies that exposed implants, the risk of PJI was low but significantly higher than not having a traumatic arthrotomy. We recommend urgent surgical irrigation and debridement, inspection of arthrotomy integrity, and antibiotic treatment to decrease the risk of PJI. Summary. An acute, traumatic wound dehiscence with in the first 30 days after primary TKA results in a 11% risk of infection at 2 years

Aims

Metaphyseal cones with cemented stems are frequently used in revision total knee arthroplasty (TKA). However, if the diaphysis has been previously violated, the resultant sclerotic canal can impair cemented stem fixation, which is vital for bone ingrowth into the cone, and long-term fixation. We report the outcomes of our solution to this problem, in which impaction grafting and a cemented stem in the diaphysis is combined with an uncemented metaphyseal cone, for revision TKA in patients with severely compromised bone.

Aims

It has been hypothesized that a unicompartmental knee arthroplasty (UKA) is more likely to be revised than a total knee arthroplasty (TKA) because conversion surgery to a primary TKA is a less complicated procedure. The purpose of this study was to determine if there is a lower threshold for revising a UKA compared with TKA based on Oxford Knee Scores (OKSs) and range of movement (ROM) at the time of revision.

Aims

Varus-valgus constrained (VVC) implants are often used during revision total knee arthroplasty (TKA) to gain coronal plane stability. However, the increased mechanical torque applied to the bone-cement interface theoretically increases the risk of aseptic loosening. We assessed mid-term survivorship, complications, and clinical outcomes of a fixed-bearing VVC device in revision TKAs.

Aims

Knee osteonecrosis in advanced stages may lead to joint degeneration. Total knee arthroplasty (TKA) for osteonecrosis has traditionally been associated with suboptimal results. We analyzed outcomes of contemporary TKAs for osteonecrosis, with particular emphasis on: survivorship free from aseptic loosening, any revision, and any reoperation plus the clinical outcomes, complications, and radiological results.

Aims

There is little information regarding the risk of a patient developing prosthetic joint infection (PJI) after primary total knee arthroplasty (TKA) when the patient has previously experienced PJI of a TKA or total hip arthroplasty (THA) in another joint. The goal of this study was to compare the risk of PJI of primary TKA in this patient population against matched controls.

Periprosthetic joint infection (PJI) is a major complication affecting >1% of all total knee arthroplasties, with compromise in patient function and high rates of morbidity and mortality. There are also major socioeconomic implications. Diagnosis is based on a combination of clinical features, laboratory tests (including serum and articular samples) and diagnostic imaging. Once confirmed, prompt management is required to prevent propagation of the infection and further local damage. Non-operative measures include patient resuscitation, systemic antibiotics, and wound management, but operative intervention is usually required. Definitive surgical management requires open irrigation and debridement of the operative site, with or without exchange arthroplasty in either a single or two-stage approach. In all options, the patient's fitness, comorbidities and willingness for further surgery should be considered, and full intended benefits and complications openly discussed. Late infection almost invariably leads to implant removal but early infections and acute haematogenous infections can be managed with implant retention – the challenge is to retain the original implant, having eradicated infection and restored full function. Debridement with component retention: Open debridement is indicated for acute postoperative infections or acute haematogenous infections with previously well-functioning joints. To proceed with this management option the following criteria must be met: short duration of symptoms - ideally less than 2–3 weeks but up to 6; well-fixed and well-positioned prostheses; healthy surrounding soft tissues. Open debridement is therefore not an appropriate course of management if symptoms have been prolonged – greater than 6 weeks, if there is a poor soft tissue envelope and scarring, or if a revision arthroplasty would be more appropriate due to loosening or malposition of the implant. It is well documented in the literature that there is an inverse relationship between the duration of symptoms and the success of a debridement. It is thought that as the duration of symptoms increases, other factors such as patient comorbidities, soft tissue status and organism virulence play an increasingly important role in determining the outcome. There is a caveat. Based on our learning in the hip, when we see an acute infection where periprosthetic implants are used, it is much easier to use this time-limited opportunity to remove the implants and the associated biofilm and do a single-stage revision instead of just doing a debridement and a change of insert. This will clearly be experience and prosthesis-dependent but if the cementless implant is easy to remove, then it should be explanted. One critical aspect of this procedure is to use one set of instruments and drapes for the debridement and to then implant the new mobile parts and close using fresh drapes and clean instruments. Units that have gained expertise in single-stage revision will find this easier to do. After a debridement, irrigation, and change of insert, patients continue on intravenous antibiotics until appropriate cultures are available. Our multidisciplinary team and infectious disease experts then take over and will dictate antibiotic therapy thereafter. This is typically continued for a minimum of three months. Patients are monitored clinically, serologically, and particularly in relation to nutritional markers and general wellbeing. Antibiotics are stopped when the patients reach a stable level and are well in themselves. All patients are advised to re-present if they have an increase in pain or they feel unwell

Aims

This study describes and compares the operative management and outcomes in a consecutive case series of patients with dislocated hemiarthroplasties of the hip, and compares outcomes with those of patients not sustaining a dislocation.

Aims. The results of irrigation and debridement with component retention (IDCR) in the treatment of acutely infected total knee arthroplasties (TKAs) have been variable. The aim of this study was to assess the outcome after IDCR when combined with chronic antibiotic suppression. We also evaluated survivorship free from subsequent infection, removal of the components, and death, as well as the risk factors for failure. Patients and Methods. This was a single-centre retrospective review of 134 infected primary TKAs that were treated with IDCR. Infections within four weeks of the procedure were defined as acute postoperative infections, and those occurring more than four weeks after the procedure with symptoms for less than three weeks were defined as acute haematogenous infections. Patients were treated with intravenous antibiotics for four to six weeks, followed by chronic oral antibiotic suppression. Estimates of survival were made using a competing risk analysis. The mean follow-up was five years (2.1 to 13). Results. The infection was an acute postoperative infection in 23 TKAs and an acute haematogenous infection in 111 TKAs. The incidence of subsequent infection was 36% in those with an acute postoperative infection and 33% in those with a haematogenous infection, five years postoperatively (p = 0.40). Age < 60 years increased the risk of subsequent infection (hazard ratio (HR) 2.4; p = 0.009) and removal of the components (HR 2.8; p = 0.007). Infection with a staphylococcal species increased the risk of subsequent infection (HR 3.6; p < 0.001), and removal of the components (HR 3.2; p = 0.002). Musculoskeletal Infection Society host type and local extremity grade, body mass index (BMI), the duration of symptoms, gender, and the presence of a monoblock tibial component had no significant effect on the outcome. Conclusion. In a rigorously defined group of acute periprosthetic infections after TKA treated with IDCR and chronic antibiotic suppression, the infection-free survival at five years was 66%. The greatest risk factor for failure was an infection with a staphylococcal species, followed by age of < 60 years. Cite this article: Bone Joint J 2018;100-B:1471–76

Introduction. Single-stage resection and reimplantation for periprosthetic joint infection (PJI) in total hip arthroplasty (THA) is of recent interest, yet outcomes may be skewed by selected populations with healthier patients and less virulent organisms. This study quantified the effectiveness of a contemporary, evidence-based and standardized two-stage treatment protocol in patients with THA PJI including chronically infected, poor hosts. Methods. Sixty-one consecutive two-stage resection and reimplantation THAs for PJI between 2011 and 2017 were retrospectively reviewed in a prospectively collected registry database. Patients were categorized with McPherson's Staging System and infection was defined by MSIS criteria. Contemporary standardized protocols were adhered to including implant resection and meticulous surgical debridement, six-week intravenous antibiotics with a high-dose antibiotic spacer, a two-week drug holiday, and laboratory assessment of infection eradication prior to reimplantation. Extended antibiotics after reimplantation were not routinely used. Successful treatment was defined as reimplantation with component retention at minimum two-year follow-up. Results. After exclusions for confounds, 43 of 47 patients had obtained minimum two-year follow-up (mean 50.9 months). 54% were male with an average BMI of 31 kg/m2. 56% were chronically infected poor hosts (Stage III-B/C). Three patients required repeat debridement and/or spacer exchange prior to final reimplantation. Treatment success rate was 95% at two-year follow-up. Success did not vary based on patient sex, age, BMI, or multi-organism PJI (p ≥ 0.117). There were no failures in the early postoperative PJI group (stage I), and both failures occurred in the late chronic PJI group (stage III). Conclusion. Our success rate with the two-stage procedure equals or exceeds that of single-stage treatment, even in an unselected cohort of chronically infected poor hosts. More rigorous scientific comparative studies are warranted prior to indiscriminate adoption of the single-stage treatment approach for PJI in THA

Implant selection in TKA remains highly variable. Surgeons consider pre-operative deformity, patient factors such as BMI and bone quality, surgical experience, retention or substitution for the PCL, type of articulation and polyethylene, cost, and fixation with or without cement. We have most frequently implanted the same implant for the majority of patients. This is based on the fact that multiple large series of TKAs have demonstrated that the most durable TKAs have been non-modular metal-backed tibial components, retention of the PCL, with a cemented all-polyethylene patellar component. Polymer wear must be addressed for long-term durability. One method for reducing polyethylene wear is eliminating modularity between a metal-backed tray and the articular bearing surface. This can be done with a metal-backed implant as with the IB-1, AGC, Vanguard Mono-lock, or with elimination of the metal backing via a one piece all-polyethylene tibial component. The all-polyethylene implants appear design and patient sensitive. We observed higher clinical failure rates in a flat-on-flat design. Other authors have observed improved survivorship with coronal dishing of the articular surfaces which centralises osseous stresses. All-polyethylene implants have promise in the future but require proven design and fixation design features

Deep peri-prosthetic infection after partial or total knee arthroplasty is a disconcerting problem for patient and surgeon alike. The diagnosis of infection is sometimes obvious but frequently requires that the surgeon maintain a substantial index of suspicion for infection as the cause of pain or poor outcome after any joint arthroplasty. While surgical debridement with component retention is appropriate in a subgroup of patients with an acute peri-prosthetic infection, most delayed and chronic infections are best treated with component resection. With carefully selected patients and very aggressive debridement protocols some success has been demonstrated in Europe with single-stage exchange for infection. Most surgeons in North America, however, are unfamiliar with the very aggressive debridement techniques employed at European centers that promote single stage replant; and few surgeons in North America are currently comfortable in cementing a hinged total knee replacement in place for the typical infected TKA nor do they have the patience to re-prep and drape with an entirely new OR setup after debridement and prior to the insertion of the new implant − 2 steps that are often mentioned as important to the success of single stage exchange. The pre-eminent role of two-stage exchange as the definitive treatment was established over 30 years ago. Two-stage exchange remains the gold-standard in treatment with an established track record from multiple centers and with multiple different types of infecting organisms. Some of the historical problems with two-stage exchange, such as limited mobility during the interval stage, have been mitigated with the development of effective articulating spacer techniques. Further, the emergence of drug resistant bacteria and the possibility of fungal infection make two-stage exchange the best choice for the majority of patients with deep periprosthetic joint infection in 2017

Uncemented component retention with polyethylene (PE) liner and femoral head exchange is commonly used to treat periprosthetic osteolysis. The purpose was to determine long-term implant survivorship, risk factors for aseptic failures, clinical outcomes, and complications following PE liner and head exchange. We identified 116 hips in 110 patients treated with PE liner and head exchange for osteolysis from 1993 to 2004. The mean age was 58, 64 were women, and mean follow-up was 11 years. Implant survivorship free from all-cause revisions was 91% at 5-years, 81% at 10-years, and 69% at 15-years. Reasons for re-revision included subsequent conventional PE wear and osteolysis in 7 (6%), aseptic acetabular loosening in 5 (4%), and instability in 5 hips (4%). Mean time to revision for aseptic acetabular loosening was 4 years (range 1 – 7 years). Risk factors for aseptic acetabular loosening included acetabular zones of pre-revision osteolysis, percentage of cup involvement, and size of osteolytic defects. Absolute risk of acetabular loosening was 23% for three zones of osteolysis (Relative Risk (RR) 12, p<0.01), 40% if osteolysis involved more than half the cup circumference (RR 14, p<0.01), and 21% for defects greater than 600 mm. 2. (RR 11, p<0.01). Harris hip scores improved from 77 to 87 (p<0.01). The most common complication was dislocation (16%). These data quantify risk of subsequent component loosening when well fixed, uncemented implants are retained during operations for osteolysis, and may inform operative decisions regarding shell retention versus revision