Aims

While interdisciplinary protocols and expedited surgical treatment improve the management of hip fractures in the elderly, the impact of such interventions on patients specifically undergoing arthroplasty for a femoral neck fracture is not clear. We sought to evaluate the efficacy of an interdisciplinary protocol for the management of patients with a femoral neck fracture who are treated with an arthroplasty.

Introduction

The efficacy of Virtual Reality (VR) as a teaching augment for arthroplasty has not been well examined for unfamiliar multistep procedures such as unicompartmental knee arthroplasty (UKA). This study sought to determine if VR improves surgical competence over traditional procedural preparation when performing a UKA.

Introduction

While interdisciplinary protocols and expedited surgical treatment improve management of geriatric hip fractures, the impact of such interventions on patients undergoing specifically arthroplasty for femoral neck fracture (FNF) has not been well studied. The aim of this study is to evaluate the efficacy of an interdisciplinary hip fracture protocol for patients undergoing arthroplasty for acute FNF.

Introduction

Surgical management of PJI remains challenging with patients failing treatment despite the best efforts. An important question is whether these later failures reflect reinfection or the persistence of infection. Proponents of reinfection believe hosts are vulnerable to developing infection and new organisms emerge. The alternative hypothesis is that later failure is a result of an organism that was present in the joint but was not picked up by initial culture or was not a pathogen initially but became so under antibiotic pressure. This multicenter study explores the above dilemma. Utilizing next-generation sequencing (NGS), we hypothesize that failures after two stage exchange arthroplasty can be caused by an organism that was present at the time of initial surgery but not isolated by culture.

Introduction

With the rising utilization of total joint arthroplasty, the role of simultaneous-bilateral surgery has expanding impact. The purpose of this study is to examine the risk of perioperative complications for this approach in total knee arthroplasty to inform shared decision making.

Introduction

Increasingly, patients with bilateral hip arthritis wish to undergo staged total hip arthroplasty. With the rise in demand for arthroplasty perioperative risk assessment and counseling is critical for shared decision making; however, it is unknown if complications that occur after a unilateral hip arthroplasty predict complications following surgery of the contralateral hip.

Introduction

Instability accounts for one third of revision total hip arthroplasty(rTHA) performed in the United Kingdom. Removal of well-fixed femoral stems in rTHA is challenging with a risk of blood loss and iatrogenic damage to the femur. The Bioball Universal Adaptor (BUA) (Merete, Germany), a modular head neck extension adaptor, provides a mechanism for optimisation of femoral offset, leg length and femoral anteversion. This can avoid the need for femoral stem revision in selected cases. There is a relative paucity of clinical data available with the use of this device.

Introduction

While component malposition remains a major short and long term problem associated with total hip arthroplasty, enhanced technologies such as navigation and robotics have not yet been widely adopted. Both expense and increased OR time can be obstacles to adoption. The current study assesses the effect of the use of a smart mechanical navigation system on surgery time in total hip arthroplasty.

Introduction

Dual modular femoral stems for total hip arthroplasty were initially introduced to optimize joint biomechanics. These implants have been recalled due to fretting and crevice corrosion at the stem-neck interface, ultimately necessitating revision in a significant number of patients. At our institution we had experience with the Rejuvenate (Stryker, Mahwah, NJ) dual modular stem from 2009 until 2011 before it's recall in 2012. This study identifies complications encountered in patients requiring revision of this prosthesis.

INTRODUCTION

Corrosion of modular tapers is increasingly recognized as a source of adverse tissue reaction (ALTR) and revision surgery in total hip arthroplasty (THA). The incidence of corrosion and rate of revision for ALTR may differ among different types of implants.

Wear simulator studies suggest low wear rates of Alumina ceramic femoral heads with polyethylene total hip bearings. Short-term wear and clinical data of ceramic/highly crosslinked ultra-high molecular weight polyethylene (UHMWPE) couples are under reported in the literature. A retrospective review was performed to determine and compare the wear rate for hips implanted with an Alumina ceramic femoral head and X3® poly-ethylene insert to the acceptable polyethylene wear rate in the literature.

We evaluated 70 primary total hip replacements performed at one institution, by two surgeons, from February 2006 through June 2007. At a minimum 2 year follow-up, calculated annual wear for the ceramic/X3^® polyethylene articulations showed a significant decrease compared to literature reports of 0.1mm/year or greater for conventional polyethylene.

Radiographic and clinical outcomes show no loose implants, dislocations, ceramic fractures or revision surgeries at last follow-up. These early findings suggest that ceramic/X3^® bearing couples may serve as an acceptable choice for the younger, active patient.

Introduction: The Durom hip acetabular component is a large diameter metal on metal (MoM) implant that has recently been the subject of much controversy. Dr. Lawrence Dorr, reported in a letter in April 2008 to the American Association of Hip and Knee Surgeons a worryingly high number of early revisions, as many as 8%, within the first 2 years as a result of a loose acetabular component. Following a Zimmer investigation an early revision rate of 5.7% in the US, but not in Europe, was revealed and this has resulted in the withdrawal of the implant from the market in the US and justifiable concern with regards to its usage resulting in decreased implantation within the UK. Surgical technique in the US has been sited as the main reason for failure as a result of low volume centres not performing crucial steps in the technique which include, but are not limited to, line-to-line reaming, use of trials in every case, proper cup position for this device, appropriate impaction techniques and no repositioning. We present the short term results and our experience of the Durom Acetabular component in our centre in the UK.

Method: We reviewed all patients that had a Durom Acetabular component implanted since its usage began in our unit in 2003. No patients were excluded and the end point being revision surgery of the Durom acetabular component. In addition we analysed the plain radiographs of a random selection of 50 patients to assess component integration.

Results: 260 patients had undergone primary hip surgery with the implantation of the Durom Acetabular component. 108 as part of a hip resurfacing and 152 as a large bearing MoM THR. Their follow up ranged from 1 to 7 years. 1 had undergone revision for thigh pain with aseptic failure of the acetabular component, 1 for ALVAL, 3 had undergone revison for infection and 1 for peri-prosthetic fracture. Analysis of the radiographs revealed a number of acetabulae with a lucent line visible around the implant. None of the implants had migrated from their original position at implantation.

Conclusions: At present their appears to be no evidence in our unit that the Durom Acetabular component has a higher than expected rate of early revision. However, a number of patients do appear to have lucency around the component on radiographs raising the possibility of questionable bony integration and on growth. Reports from the United States have suggested that the cup will “spin out” easily at revision showing no signs of bony integration. This may result in an increased revision rate in the future and we suggest that all patients that have a Durom acetabular component in situ be followed up with yearly clinical assesment and radiographs to assess the longevity of this component.

Femoral head roughening is a clinically observed phenomenon that is suspected to cause increased wear of acetabular inserts. Two approaches have been taken to reduce hip bearing wear. Improved femoral head materials may decrease the impact of roughening and reduce the effect of abrasion. Additionally, improved polyethylene materials may be utilized to reduce wear against smooth or roughened femoral heads. This study looks at these two approaches in the form of a toughened alumina femoral head (Biolox Delta) and a sequentially crosslinked and annealed polyethylene (X3). A wear study was performed with new and artificially scratched ceramic femoral heads (28mm Biolox Delta) as compared to new and artificially scratched Cobalt Chromium femoral heads. These femoral heads were articulated against both conventional (N2\Vac) and highly crosslinked (X3) polyethylene acetabular cups. Artificial scratching utilized a Rockwell C indentor loaded at 30N to scratch a multidirectional scratch pattern on the articulating surface of the femoral head to simulate in vivo roughening.

Delta femoral heads exhibited superior resistance to scratching. Peak to valley roughness for CoCr heads was 7.1um while Delta heads only roughened to 0.4um. Head material under standard conditions (no scratch) had no effect on PE wear (p=0.31 and p=0.53). Under abrasive conditions, the Delta femoral head exhibited a clear advantage over CoCr heads (65–97% reduction in wear rate; p< 0.007). X3 polyethylene also showed a clear advantage over conventional PE against either CoCr or Delta heads and under both conditions (all p < 0.012).

This study clearly demonstrates that X3 polyethylene has a clear wear advantage over conventional polyethylene despite head material or abrasive conditions. Secondary to the polyethylene choice, the use of a ceramic femoral head leads to superior performance under abrasive conditions.

Periprosthetic fractures present an increasing workload as more hip arthroplasties are performed. They are often challenging to treat due to poor bone stock and patient frailty. We compare the early clinical and radiological results in 2 centres of 24 consecutive periprosthetic hip fractures in 24 patients, using a cannulated interlocked long stemmed titanium alloy femoral component with or without a hydroxyapatite (HA) coating (Cannulok revision prosthesis).

The mean age at the time of operation was 79 years (range 65 to 92.4 years). The average length of follow up was 1.17 years (range 3 months to 5.3 years). All patients receiving a Cannulok revision stem with a minimum follow up of 3 months were included regardless of their primary aetiology and number of previous surgical procedures. Patients were reviewed and scored using the Merle d’Aubigne and Postal Score, Harris Hip Score and the WOMAC index at latest review. Periprosthetic fractures were classified using the Vancouver classification. At latest radiological review we measured subsidence, new bone formation (including presence of callus), osteolysis and radiolucent lines in all areas of the stem.

Of the 24 fractures, 22 healed. In the 14 who had HA coated implants there was a 50% increase in bone. In the non-HA coated stems there was a 36% increase in bone radiologically. The mean Harris hip score was 74 at the latest post-operative review. The mean WOMAC and MDP scores were 48.7 and 7.7 respectively. The mean pain visual analogue score was 1.6 overall and 0 specifically for mid-thigh pain.

We present encouraging early clinical and radiological results of the Cannulok stem system for treatment of complex periprosthetic fractures. This implant provides early fracture stability and subsequent biological bonding with an improvement in bone mass.

Treatment for developmental dysplasia and dislocation of the hip (DDH) presenting after one year of age is controversial. There are advocates of both open and non-operative reduction. Surgeons advocating open reduction believe in excising the obstructing soft tissues for all such cases. Others reducing non-operatively suggest that pressure from a reduced femoral head provides gradual concentric reduction with remodelling of the restraints. MR images of hips in a group of patients treated non-operatively were examined to determine the long-term development of the soft tissue around the hip.

We have been treating late presented DDH by graduated traction and gentle manipulation under general anaesthetic since 1975. 10 (12 hips) of these patients were consented to have an MRI Scan of their hips. Mean age of presentation was 17 months (13–36 months). Mean follow up was 16 years (7–26 years). Mean duration of traction was 31 days (16–45 days). None of the hips had an open reduction. Subsequently 3 hips had a femoral osteotomy at a mean age of 5. 9 years (4. 1–7. 8) and 3 hips underwent a Salter-type osteotomy at a mean age of 4. 3 years (3. 7–5. 4).

According to the grading of Barrett et al, 9 hips were graded clinically excellent, 2 were good and 1 hip was fair. The latest radiological result was graded according to Severin. There were 9 grade 1 hips, 2 grade II hips and 1 grade III.

All the patients had coronal, sagittal and transverse scans of both their hips. All the MRI Scans showed a good coverage of the femoral head. Anterior and posterior acetabular cover was adequate in all the hips. Osseo-cartilaginous extension beyond the acetabular margin was constantly found in all the hips. Even in the hip with a Severin score of III, the cartilaginous acetabular extension produced a concentric hip joint. The anterior and the posterior labrum were found to be well developed in all the hips. None of the hips showed any evidence of inverted limbus. 3 hips showed mild evidence of avascular necrosis but there was no evidence of collapse or flattening. Thinning of the articular cartilage was seen in 3 hips but no mechanical changes observed. Capsule and ligamentum teres were found to be well developed and non-obstructive.

Long-term results of non-operative treatment of late presented DDH have been found to be satisfactory. The MRI scans have shown an excellent soft tissue remodelling around the hip. Soft tissue restraints preventing initial reduction in late-presented DDH are therefore not an absolute indication for open exploration. MRI scans were found to be an excellent tool to study the effect of soft tissue remodeling in such cases.