With an ageing population and an increasing number of primary arthroplasties performed, the revision burden is predicted to increase. The aims of this study were to 1. Determine the revision burden in an academic hospital over a 11-year period; 2. identify the direct hospital cost associated with the delivery of revision service and 3. ascertain factors associated with increased cost. This is an IRB-approved, retrospective, single tertiary referral center, consecutive case series. Using the hospital data warehouse, all patients that underwent revision hip or knee arthroplasty surgery between 2008-2018 were identified. 1632 revisions were identified (1304 patients), consisting of 1061 hip and 571 knee revisions. The majority of revisions were performed for mechanical-related problems and aseptic loosening (n=903; 55.3%); followed by periprosthetic joint infection (n=553; 33.9%) and periprosthetic fractures (176; 10.8%). Cost and length of stay was determined for all patient. The direct in-hospital costs were converted to 2020 inflation-adjusted Canadian dollars. Several patients- (age; gender; HOMR- and ASA-scores; Hemoglobin level) and surgical- (indication for surgery; surgical site) factors were tested for possible associations. The number of revisions increased by 210% in the study period (2008 vs. 2018: 83 vs. 174). Revision indications changed over study period; with prevalence of fracture increasing by 460% (5 in 2008 vs. 23 in 2018) with an accompanying reduction in mechanical-related reasons, whilst revisions for infection remained constant. The mean annual cost over the entire study period was 3.9 MMCAD (range:2.4–5.1 MMCAD). The cost raised 150% over the study period from 2.4 MMCAD in 2008 to 3.6 MMCAD. Revisions for fractured had the greatest length of stay, the highest mean age, HOMR-score, ASA and cost associated with treatment compared to other revision indications (p < 0 .001). Patient factors associated with cost and length of stay included ASA- and HOMR-scores, Charlson-Comorbidity score and age. The revision burden increased 1.5-fold over the years and so has the direct cost of care delivery. The increased cost is primarily related to the prolonged hospital stay and increased surgical cost. For tertiary care units, these findings indicate a need to identify strategies on improving efficiencies whilst improving the quality of patient care (e.g. efficient ways of reducing acute hospital stay) and reducing the raise of the economic burden on a publicly funded health system

When removing femoral cement in revision hip surgery, creating an anterior femoral cortical window is an attractive alternative to extended trochanteric osteotomy. We describe our experience and evolution of this technique, the clinical and radiological results, and functional outcomes. Between 2006 and 2021 we used this technique in 22 consecutive cases at Whanganui Hospital, New Zealand. The average age at surgery was 74 years (Range 44 to 89 years). 16 cases were for aseptic loosening: six cases for infection. The technique has evolved to be more precise and since 2019 the combination of CT imaging and 3-D printing technology has allowed patient-specific (PSI) jigs to be created (6 cases). This technique now facilitates cement removal by potentiating exposure through an optimally sized anterior femoral window. Bone incorporation of the cortical window and functional outcomes were assessed in 22 cases, using computer tomography and Oxford scores respectively at six months post revision surgery. Of the septic cases, five went onto successful stage two procedures, the other to a Girdlestone procedure. On average, 80% bony incorporation of the cortical window occurred (range 40 −100%). The average Oxford hip score was 37 (range 22 – 48). Functional outcome (Oxford Hip) scores were available in 11 cases (9 pre-PSI jig and 2 using PSI jig). There were two cases with femoral component subsidence (1 using the PSI jig). This case series has shown the effectiveness of removing a distal femoral cement mantle using an anterior femoral cortical window, now optimized by using a patient specific jig with subsequent reliable bony integration, and functional outcomes comparable with the mean score for revision hip procedures reported in the New Zealand Joint Registry

Introduction

A proportion of patients with hip and knee prosthetic joint infection (PJI) undergo multiple revisions with the aim of eradicating infection and improving quality of life. The aim of this study was to describe the microbiology cultured from multiply revised hip and knee replacement procedures to guide antimicrobial therapy at the time of surgery.

Aim. To evaluate the costs of performing revision hip and knee surgery at a District General Hospital. Methods. A retrospective review of all revision hip and knee surgery between October 2004 and October 2006 was performed. Information was obtained from the notes and theatre log books. Each case was fully costed. The breakdown costs included implant choice, theatre time, length of stay, allograft, blood products and post-operative physiotherapy/OT. The costs were obtained from the hospital financial department and theatre invoices. Payment to the hospital is based on a specific tariff which in turn is determined by coding each patient episode. We individually coded every case, using the OPCS 4.3 coding system, and applied the appropriate tariff. The tariffs that the financial department had applied to each case were also available. A comparison was made between actual costs incurred, the expected reimbursement (from our study coding) and the actual reimbursement received (from finance department). Results. 167 revision procedures were performed (108 hips and 59 knees). The total incurred cost of revision hip surgery was £930,156 (mean £8,613 per case). The expected total reimbursement according to our coding was £938,325 (mean £8,688). The total reimbursement actually received was £806,836 (mean £7,471). The total incurred cost of revision knee surgery was £493,357 (mean £8,362). The expected total reimbursement according to our coding was £499,042 (mean £8,458). The total reimbursement was £419,157 (mean £7,104). Conclusions. Inadequate coding results in reduced income. If strict coding practices are adhered to then performing revision hip and knee surgery should be financially viable at a district general hospital

Introduction. Revision hip arthroplasty with massive proximal femoral bone loss remains challenging. Whilst several surgical techniques have been described, few have reported long term supporting data. A proximal femoral allograft (PFA) may be used to reconstitute bone stock in the multiply revised femur with segmental bone loss of greater than 8 cm. This study reports the outcome of largest case series of PFA used in revision hip arthroplasty. Methods. Data was prospectively collected from a consecutive series of 69 revision hip cases incorporating PFA and retrospective analyzed. Allografts of greater than 8 cm in length (average 14cm) implanted to replace deficient bone stock during revision hip surgery between 1984 and 2000 were included. The average age at surgery was 56 years (range 32–84) with a minimum follow up of 10 years and a mean of 15.8 years (range). Results. From the original cohort four patients had died with the original PFA, 21 (30.4%) patients required further surgery with 14 (20.3%) of these needing revisions of the femoral component. The mean time to femoral revision was 9.5 years and Kaplan-Meier survivorship analysis demonstrates a 79.9% PFA survivorship at 20 years. Discussion. Proximal femoral allograft affords long lasting reconstruction of the femoral component in revision hip surgery. We advocate PFA as an attractive option in the reconstruction of the hip in the presence of significant segmental bone loss in younger patients

Background. Revision total hip arthroplasty is a technically demanding procedure and especially removing a well fixed femoral stem is a challenge for revision surgeons. There are various types of trochanteric osteotomies used during revision surgery; extended trochanteric osteotomy (ETO) is being more popular. Aim. The aim of this study is to look at types of trochanteric osteotomy used during the revision surgery. We looked at the success and failure of these osteotomies. Failure of the osteotomy is defined by complete pull off by the hip abductors resulting in osteotomy fragment is no contact with the femur. We sought to assess the time to healing of osteotomy and number of cables used. Methods. We retrospectively reviewed the hospital theatre database and identified 97 patients who underwent revision hip surgery from June 2008 to December 2015. Among these 35 patients (36% of patients) had trochanteric osteotomy for either extraction of femoral stem or removal of cemented mantle. Results. Most common cause of revision was aseptic loosening in 22 cases (62%) followed by peri prosthetic fracture 6 cases (17%), 1. st. stage of revision surgery in infective cause in 4 cases (11%). Depending on the length of the osteotomy performed we divided the patients into two groups. The first group had osteotomy just around the greater trochanter, which is called short trochanteric osteotomy group and the second group had extended trochanteric osteotomy where the osteotomy length is at least of 15cms and preserving the vastus lateralis attachment to the osteotomy. 7 patients had short trochanteric osteotomy and remaining 28 patients had extended trochanteric osteotomy. In the short trochanteric osteotomy group had 4 out of 6 patients had failure of the osteotomy repair. In extended trochanteric osteotomy group, there was one immediate failure and another one had delayed trochanteric pull off out of 28 patients (93% success rate). The time taken for the osteotomy to heal in short trochanteric osteotomy group was 8 months where as in the extended osteotomy group it was 5 months. The mean number of cables used was 3 in both groups. There was no subsidence seen during the post op follow up in either group. Conclusion. Our study concluded that ETO is a safe procedure with a low complication rate rather than short trochanteric osteotomy. Implications. Awareness about the biomechanics of ETO and its indications can make ETO an important tool in the revision surgeon's armamentarium

The process of femoral impaction grafting requires vigorous impaction to obtain adequate stability but the force of impaction has not been determined. This process has been reported to result in femoral fractures with rates reaching 16%. The aims of this study were to determine the threshold force required for femoral impaction grafting, to determine the affect cortical thickness, canal diameter and bone mineral density (BMD) have on this threshold force and to measure subsidence of an Exeter prosthesis following impaction at the threshold force. Adult sow femurs were prepared and placed through a DEXA scanner and the BMD and canal diameter measured. Thirty five femurs were impacted with morsellised bone chips and an increasing force of 0.5kN was applied until the femur fractured. Using callipers the cortical thickness of the bone was measured along the fracture line. Once the threshold force was determined 5 femurs were impacted to this threshold force and an Exeter stem was cemented into the neomedullary canal and a 28mm Exeter head attached. Axial cyclic loading was performed between 440N (swing phase of gait) and 1320N (stance phase of gait) for 150,000 cycles at a frequency of 3Hz. The position sensor of the hydraulic testing machine measured the subsidence. 29 tests were successfully completed. The threshold force was found to be 4kN. There was no significant correlation between the load at fracture and the cortex: canal ratio or the bone mineral density. Following impaction with the maximum force of 4kN the average subsidence for the 5 femurs was 0.276mm (range 0.235 – 0.325mm). In this animal study the threshold force was 4kN. Minimal axial subsidence of the implant occurred when impacting the graft with this threshold force. We therefore achieved a stable construct without fracture which is the ultimate goal for the revision hip surgeon

BACKGROUND

The most common salvage of a failed metal-on-metal hip resurfacing is to remove both the femoral and acetabular resurfacing components and perform a total hip replacement. The other choices are to perform an acetabular or femoral only revision. A one or two piece acetabular component or a polyethylene bipolar femoral component that matches the retained metal resurfacing acetabular component is used. The considerations in favor of performing a one component resurfacing revision are maintaining the natural femoral head size, limiting the surgical effort for the patient and surgeon, and bone conservation. There are often favorable cost considerations with single component revision surgery.

The reasons for femoral component revision are femoral neck fracture, femoral component loosening and an adverse reaction to metal wear debris. Performing a femoral component only revision requires a well fixed and well oriented acetabular component. Acetabular revision is most often performed for an adverse reaction to metal wear debris or loosening.

Background

The use of tranexamic acid (TEA) can significantly reduce the need for allogenic blood transfusions in elective primary joint arthroplasty. Revision total hip arthroplasty requires increased utilization of post-operative blood transfusions for acute blood loss anemia compared to elective primary hip replacement. There is limited literature to support the routine use of TEA in revision THA.

Introduction

Revision hip arthroplasty is a technically challenging operation as proximal bony deficits preclude the use of standard implants. Longer distally fixing stems are therefore required to achieve primary stability.

Total hip replacements have shown great benefits to patients through relief of pain and restoration of function. However, because of the extensive variation in the size and shape of the femoral canal, especially for the situation encountered in the revision hip arthroplasty, standard uncemented hip systems with a limited number of sizes are unable to provide an accurate fit in every case. This study showed clinical results of 112 primary total hip replacements and 158 revision total hip replacements, using custom made CAD-CAM (Computer Aided Design-Computer Aided Manufactured) hip prostheses inserted between 1992 and 1998.

For primary hip replacements, the implants were designed to produce proximal line-to-line fit with the femoral bone and to provide optimal biomechanical environment of the hip. The stem was HA coated, 53 males and 58 females were included. Mean age was 46.2 years (range 24.6yrs - 62.2 yrs). The average duration of the follow up was 24 years (10 – 17 years). The mean Harris Hip Score (HHS) was improved from 42.4 to 90.3, mean Oxford Hip Score (OHS) was improved from 43.1 to 18.2 and the mean WOMAC hip score was improved from 57.0 to 11.9. There was 1 revision due to failure of the acetabular components but there were no failures of the femoral components. In the whole follow-up period, the survival of the femoral stem alone was 100%.

For revision hip replacements, the implants were designed using our design strategies of graduate approach to different revision situation based on Paprosky's classification of femoral bone defect. The implants were HA coated; some of them had distal cutting flutes. A total of 158 patients (97 males and 61 females) who had operation between 1991 and 1998 were followed up, among them 138 cases were due to aseptic loosening, 6 cases were periprosthetic fractures and 14 cases were infection. The average age was 63.1 years (range 34.6 – 85.9 years). The minimum follow up was 10 years (range 10 – 12 years). The mean Harris Hip Score was improved from 44.2 to 89.3, mean Oxford Hip Score was improved from 41.1 to 18.2 and the mean WOMAC hip score was improved from 52.4 to 12.3 respectively. 6 cases required further revision surgery, among them 3 were due to aseptic implant loosening, the overall survivorship at ten years was 97%.

The CAD-CAM hip stems are able to provide optimal implant fixation and restore hip function for every patient regardless their original femoral shape, bone condition and biomechanics of the hip. The excellent medium to long term clinical results justifies the use of CAD-CAM custom hip stems.

Acetabular reconstruction with impaction bone grafting and a cemented polyethylene aims to reconstitute the bone stock in hip revision. This is an effective but expensive, resource intensive and time consuming technique. Most surgeons remove the articular cartilage from the femoral head allograft. The aim of this study is to reproduce the results using the whole femoral head with the articular cartilage for acetabular impaction grafting. 38 acetabular revisions using impacted morselised bone graft retaining the articular cartilage and a cemented cup were studied retrospectively. The operations were performed by the senior author in Wrightington Hospital, UK with a posterior hip approach. The mean follow up was 4.1 years (range, 1–10 years). Clinical and radiological assessment was made using the Oxford hip score, Hodgkinson's criteria (1988) for socket loosening and the Gie classification (1993) for evaluation of allograft incorporation. Thirty-six (94.7%) sockets were considered radiologically stable (type 0, 1, 2 demarcations) and two (5.3%) sockets were radiologically loose (type 3 demarcations) but there was no socket migration. Twenty-one (55.3%) cases showed good trabecular remodeling (grade 3). Fourteen (36.8 %) cases showed trabecular remodeling (grade 2). Only three (7.9%) cases showed poor allograft incorporation (grade 1). Mean pre-operative hip score was 41 and post-operative hip score was 21. There was one (2.6%) wound infection treated with oral antibiotics and one (2.6%) periprosthetic femoral fracture treated with cables. Furthermore, there was one (2.6%) case of pulmonary embolism and three (7.89%) cases of asymptomatic heterotopic ossification. One year mortality rate was 2.6% (one case) from heart failure but not associated with the surgery. There have been no socket re-revisions (100% survival) at an average of 4 years. At a mean follow up of 4 years, results with the aforementioned technique are comparable to other major studies. Compared to the 40% of minimal loss in obtaining pure cancellous graft less than 10% of initial graft mass is lost without removing the articular cartilage. Particularly when the supply of allograft and operative time are limited retaining the articular cartilage of the femoral head is a safe and effective alternative to be considered

Studies on soil mechanics have established that when vibration is applied to an aggregate, it results in more efficient alignment of particles and reduces the energy required to impact the aggregate. Our aim was to develop a method of applying vibration to the bone impaction process and assess its effect on the mechanical properties of the impacted graft.

Phase 1. Eighty bovine femoral heads were milled using the Noviomagus bone mill. The graft was then washed using a pulsed lavage normal saline system over a sieve tower. A vibration impaction device was developed which housed two 15V DC motors with eccentric weights attached inside a metal cylinder. A weight was dropped onto this from a set height 72 times so as to replicate the bone impaction process. A range of frequencies of vibration were tested, as measured using an accelerometer housed in the vibration chamber. Each shear test was then repeated at four different normal loads so as to generate a family of stress-strain curves. The Mohr-Coulomb failure envelope from which the shear strength and interlocking values are derived was plotted for each test.

Phase 2. Experiments were repeated with the addition of blood so as to replicate a saturated environment as is encountered during operative conditions.

Relatively dry graft impacted with the addition of vibration showed improved shear strength at all frequencies of vibration when compared to impaction without vibration. In our system the optimal frequency of vibration was 60 Hz. Under saturated conditions the addition of vibration is detrimental the shear strength of the aggregate. This is secondary to decreased interlocking between particles and may be explained by the process of liquefaction.

An attempt to analyse whether impaction allografting without cement is more or less satisfactory than the technique with the addition of cement is compromised by conflicting reports of where the migration actually occurs. In some cemented series distal migration of the prosthesis within the cement mantle has been recorded as well as migration of the whole cement/prosthesis construct into the graft.

Two prospective consecutive series of revision hip arthroplasties by a single surgeon:- Group 1; Uncemented impaction grafting revision hip replacement in a series of 30 patients (33 hips). Group 2; Cemented impaction grafting revision hip replacement in a series of 30 patients (31 hips). Group demographics were similar. Each case used the same design of hip implant with the only difference in design being a proximal hydroxyapatite coating used on the uncemented implants.

Follow-up ranged from 2 to 17 years for the uncemented group and from 1 to 11 years for the cemented group. A validated hip scoring system was employed at regular follow up incorporating pain and functional assessment.

Migration rates for the uncemented group were 0 to 15 mm for 30 hips; however 3 hips were revised early due to excessive migration. 3 hips sustained early complications (1 fracture, 1 dislocation, 1 varus malposition of stem). Migration rates for the cemented group were 0 to 9 mm for 29 hips, however the remaining 3 hips were revised due to excessive migration (up to 33mm). Although similar results were obtained in terms of success and also pain and function scores, marginal improvement in results did occur with the cemented series overall. Statistical significance was not reached however. More sinkage occurred in the uncemented group overall, the majority occurring in the first 6 post-operative months. Part of the improvement with the cemented series results may be explained by the improved techniques achieved whilst performing the uncemented series.

These results from a single surgeon demonstrate that the method is highly technique dependent and relies on adequate graft impaction. With sufficient graft and an appropriate prosthetic design, cement is not essential to the early success of this method. However, the extent of the initial migration did not accurately predict a successful outcome for the procedure. The absence of cement removes any confusion as to the location of any migration.

Introduction:

Periprosthetic joint infection (PJI) is a devastating diagnosis that carries a significant rate of associated mortality and places a large burden on health care systems. Treatment protocols often include combined intravenous antibiotics and staged revision surgery with locally-delivered antibiotics via PMMA cement spacers and/or beads. One disadvantage of PMMA is the need for later removal. Antibiotic releasing Calcium Sulphate beads (CaSO₄) have had promising results in revision joint surgery and are absorbable, making later removal unnecessary. We report on use in a tertiary referral centre in the UK and present our initial findings.

Aim

There is limited data on the frequency and impact of untoward events such as glove perforation, contamination of the surgical field (drape perforation, laceration, detachment), the unsterile object in the surgical field (hair, sweat droplet…), defecation, elevated air temperature…that may happen in the operating theatre. These events should influence the surgical site infection rate but it is not clear to what extent. We wanted to calculate the frequency and measure the impact of these events on the infection and general revision rate.

Periprosthetic joint infections (PJI) continue to be a diagnostic challenge for orthopedic surgeons. Chronic PJI are sometimes difficult to diagnose and occasionally present in a subclinical fashion with normal CRP/ESR and/or normal joint aspiration. Some institutions advocate for routine use of intraoperative culture swabs at the time of all revision surgeries to definitively rule out infection. The purpose of this study is to determine whether routine intraoperative cultures is an appropriate and cost effective method of diagnosing subclinical chronic PJI in revision joint replacement patients with a low clinical suspicion for infection. We performed a retrospective chart review and identified 33 patients that underwent revision hip or knee replacement from a single surgeon over a five-month period. The AAOS guidelines for preoperative PJI workup were followed. 13 patients were diagnosed preoperatively with infection and excluded from the study. 20 patients underwent revision joint replacement and three separate cultures swabs were taken for each patient to help in determining true-positive cultures. Infectious Disease was consulted for all patients with any positive culture. Culture results were reviewed. At our hospital, the cost billed to insurance for a single culture is $1,458.58. We did not calculate the cost of the consultant fee. Three (15%) of the 20 revision arthroplasty patients had a single positive culture. Infectious Disease consultants diagnosed all three of these positive cultures as contaminants. None of the patients had a true-positive intraoperative culture. The total cost billed by the hospital to obtain these cultures in all 20 patients was $87,514.80. In our study, obtaining a set of three intraoperative cultures for those patients with a negative preoperative infection workup was not only cost prohibitive but did not diagnose a single subclinical infection. Studies to find other more reliable, accurate, and cost effective alternatives to diagnose PJI are warranted. In patients undergoing revision hip or knee arthroplasty with a low preoperative clinical suspicion for infection, it does not seem that routine intraoperative culture swabs are necessary or cost effective method for diagnosing subclinical periprosthetic joint infection

Aim

”There is not a lot of data of the frequency and impact of unwanted events including glove perforation, contamination of the surgical field (drape perforation, laceration, detachment, bone bounced back from an unsterile object), unsterile object in the surgical field (hair, sweat droplet…), defecation, elevated air temperature, and others. Mishaps occur in every surgical theatre. These events should influence the surgical site infection rate but it is not clear to what extent. We wanted to calculate the frequency and measure the impact of these events on the infection and revision rate of the relative patients.”

Treatment for an infected Total Hip replacement (THR) remains controversial with two stage revision surgery traditionally recommended. We describe a series of one stage revisions performed in a District General Hospital to help inform other surgeons and help treatment decisions.

8 patients with a bacteriologically proven infection in their hip underwent single stage revision THR. Cemented Exeter prostheses were used with additional antibiotics added to the cement mixture prior to implantation.

Follow-up ranged from 6 to 36 months (average 16.6 months) and there were no re-infections. No radiological changes consistent with re-infection were noted throughout patient follow-up. One patient suffered a periprosthetic fracture (thought to be secondary to myeloma) 3 months post-surgery and underwent further revision surgery. Post-operative antibiotics were given for a minimum of 6 weeks with 2 patients having a 3 month supply after Microbiology advice.

Single stage revision THR surgery is a viable and useful option for treatment of infected THR's. Re-infection rates are low. Avoiding the traditional second stage surgery is beneficial to both patients and the NHS trust in terms of health and cost outcomes. We will continue to undertake single stage revisions in this trust and advocate its use by other surgeons.

To discuss the rationale, selection criteria, indications, and results of using large diameter ceramic heads in revision hip arthroplasty.

We routinely use Biolox family of ceramic heads and acetabular liners in patients undergoing revision total hip replacements. We present our experience in using ceramic articular bearings over the last 20 years and the switch to larger diameter ceramic heads. We also present our rationale for using a large diameter ceramic head instead of a large metal head.

We reviewed a total of 689 revision arthroplasties over this time period and we report the outcome of large bearing couples with case examples in primary and revision scenarios. Furthermore we compared a subset of patients (110) with large diameter ceramic heads – Biolox Delta 36mm to patients who had metal on metal (large head 42 mm and above) bearing couples. The performance of the ceramic bearing couples will be discussed along with the functional outcome of these patients. We found no difference in the functional, clinical sports activities (UCLA and Tegner scores) between patients who had large metal bearing couples and large ceramic couples. Complication rate was less with the ceramic bearing revision arthroplasties, as was patient satisfaction.

Ceramic bearing couples have stood the test of time and have demonstrated an excellent long term wear properties. The recent introduction of the large diameter couples proves to be an excellent alternative if not the first choice in young, complex primary and revision case scenarios.