Background

Fractures of the femoral component are well reported complications that present a challenging task in revision total hip arthroplasty. Albeit being uncommon, with an incidence of 0.23–11%, the consequences can be devastating. Its extraction being a demanding undertaking that is potentially detrimental to the remaining host bone. Several techniques have been described to address this complex issue prior to revision: drilling of the exposed part of the femoral stem and attaching a threaded extraction device, surface undercutting with an extraction device wedged in, femoral trephine techniques, creation of a femoral cortical window, an extended femoral osteotomy procedure, as well as extraction by means of retrograde nail impaction. Here we present the modified technique we employed in the revision of a failed cementless extensively porous coated femoral component that had fractured at the neck-stem interface.

Background

Cement restrictors are used for maintaining good filling and pressurization of bone cement during hip and knee arthroplasties. The limitations of certain cement restrictors include the inability to accommodate for large medullary canals particularly in revision procedures. We describe a technique using SurgicelTM (Johnson & Johnson) and SPONGOSTAN™ (Johnson & Johnson) (Fig 1) to form a cement restrictor that can accommodate for large canal diameters and provide excellent pressurisation.

INTRODUCTION

The development of new bearing surfaces for total joint replacement is constantly evolving. Oxidized zirconium (Oxinium) has been introduced for use in both total hip arthroplasty (THA) and total knee arthroplasty (TKA). The aetiology of wear is multifactorial and includes adhesive, abrasive, third-body and fatigue wear mechanisms. Oxinium femoral components have demonstrated clear improvements in wear characteristics in-vitro. The purpose of this prospective study was to evaluate the mid-term (minimum 5 year) clinical and radiographic results and survivorship of the Genesis II™ knee implant system using an Oxinium femoral component.

Introduction

Total knee arthroplasty (TKA) has proven clinical success with reported longterm survivorship of 92% in the elderly population. Concerns regarding increased loosening rates and potential need for multiple revision surgeries in patients younger than 60 years have traditionally discouraged TKA in younger patients. The purpose of this study was to review the longterm clinical and radiographic results of patients under the age of 45 yrs who underwent a total knee replacement.

Objectives

Porous metal surfaces have been a popular option for acetabular component fixation in total hip arthroplasty (THA). New THA component designs are introduced periodically with the expectation of better wear properties and survivorship. Since its approval for use in 2002 there have been few clinical outcome studies published on the Pinnacle acetabular cup system. We hypothesised that the hemispherical porous coated Pinnacle acetabular cup system with a range of cup options and bearing surfaces would give us predictably good fixation and survivorship at five years post implantation.

Introduction

The development of new bearing surfaces for total joint replacement is constantly evolving. Oxidized zirconium (Oxinium) has been introduced for use in total hip arthroplasty (THA) and total knee arthroplasty (TKA). One of the most common causes of failure of THA is aseptic loosening secondary to polyethylene wear debris. The aetiology of wear is multifactorial and includes adhesive, abrasive, third-body and fatigue wear mechanisms. Oxidized zirconium is a relatively new material that features an oxidized ceramic surface chemically bonded to a hard metallic substrate. This material possesses the reduced polyethylene wear characteristics of a ceramic, without the increased risk of implant fracture While short-term results of oxidized zirconium in THA have been reported, there have been no reports on retrieved highly cross linked PE articulating with Oxinium headsObjectives:

Background

To determine the relative contributions of bilateral versus unilateral femoral shaft fracture plus injuries in other body regions to mortality after injury.

Introduction: Although a relationship between long-bone fractures and patient morbidity and mortality has been previously identified, the cause and effect of bilateral femoral fractures remain obscure.

Aim of Study: This study was designed to determine whether patients with bilateral femoral fractures with associated injuries die more frequently than patients with isolated bilateral femoral fractures, and the contribution of the associated injuries to patient mortality.

Materials and Methods: Retrospective analysis using the UK trauma Audit & Research Network (TARN) registry data from 1989 to 2005 on isolated bilateral femoral fractures ‘Group I’ (92) or with associated injuries ‘Group II’ (380). Univariate data analysis was performed to compare the groups’ ages, Injury Severity Scores, Glasgow Coma Scales, mortality, physiological parameters, the time to arrive to scene and the time to arrive to hospital. Logistic regression data analysis was performed to determine variables statistically associated with mortality.

Results: Patients in Group II had a significantly higher Injury Severity Score (23 vs 9), lower Glasgow Coma Scales value (12 vs 15), higher mortality rate (31.6 vs 9.8%) and lower mean systolic pressures (116 vs 135) than patients in Group I. Associated injuries included; head, thoracic, abdominal, spinal, and limb injuries. Regression analysis of variables on admission revealed a significant correlation between bilateral femoral fractures with associated injuries and.

Conclusion: From the results of this study, we conclude that patients sustaining bilateral femoral fractures with associated injuries are at a greater risk of than patients with isolated bilateral femoral fractures.

Introduction: As a result of the rapid increase in the number of hip resurfacing procedures performed, previously recognized complications have begun to recur; including, femoral neck fracture and heterotopic ossification. Hip resurfacing entails reaming of the femoral head to the appropriate size and significant bone debris produced, usually dispersed in the soft tissues. We advocate the use of a novel technique whereby the bone debris produced is collected and removed effectively without soft tissue spillage and ultimately reducing the incidence of heterotopic ossification.

Materials and Methods: A 60-ml. plastic ‘galli pot’ is prepared by cutting the floor of the container, leaving behind a rim for collecting the bone debris. The container is placed over the femoral head and across the femoral neck. The femoral reamer is applied onto the femoral head with the container in-situ and reaming commenced. The bone debris produced is collected in the container, which is removed after completing the reaming process.

Results: This technique was used effectively on patients undergoing hip resurfacing procedures using the Cormet hip (Corin Medical, Cirencester, UK) and the Birmingham Hip Resurfacing (Midland Medical Technologies, Birmingham, UK). The technique proved successful in collecting the bone debris produced and reducing bone debris in surrounding soft tissues

Discussion: Heterotopic ossification (HO) post hip arthroplasty is a relatively common phenomenon with clinical significance in approximately 5% of all cases. Moderate to severe HO, can negate the benefits of replacement surgery and reducing bone debris has been shown to reduce the incidence of HO and a more favorable outcome. We propose this technique as a method to reduce bone debris spillage in surrounding tissues whilst performing hip resurfacing procedures

Introduction: Lateral insufficiency fractures following total hip replacements have been reported with the femoral stems positioned in varus, together with osteopenia of the lateral femoral cortex. Any abnormal alignment of the lower limbs, such as genu valgum, will alter the load distribution across the femoral cortices, and repetitive loading during walking will predispose the bones to stress fractures at any stress riser point, such as the tip of a femoral component. Bilateral femoral stress fractures post total hip replacements have not been previously described

Materials and Methods: We present a 55 yr old lady, diagnosed with juvenile idiopathic arthritis aged 5 years, and had undergone bilateral total hip replacements at the age of 29 and 30 years and bilateral knee replacements aged 37 and 42 years. The right hip required revision of the cup 15 years later. The knees were in valgus and the left knee was extremely stiff flexing to just 5 degrees. She presented to us as an emergency with bilateral thigh pain with plain radiographs confirming bilateral peri-prosthetic fractures of the femur at the tip of well fixed femoral components. There had been no history of injury and her hips were functioning well up to this time.

Results: The patient required revision of both hips to long stem un-cemented components, bypassing the fractures, and revision of both knees to stemed seni-constrained implants, thereby correcting the alignment of both lower limbs.

Both fractures healed and the patient is currently pain free and mobile with walking aids.

Discussion: Surgeons must remain aware that when implants are in situ, abnormal alignments will lead to abnormal forces, and stress fractures are likely to occur at any stress riser around the implant. Avoiding mal-alignment will avoid this complication.

Bilateral peri-prosthetic stress fractures following total hip replacements have not been previously reported.