Aims

Present the outcomes of those patients diagnosed with Ewing's Sarcoma of the foot within the past 10 years and treated at the Royal National Orthopaedic Hospital's Bone Tumour Unit, Stanmore.

Infection after knee arthroplasty is a devastating complication. Our aim is to present our outcomes of treating infected knee replacements at a tertiary referral centre.

We performed a consecutive, retrospective case series of all revision knee arthroplasty for infection between January 2006 and December 2008. Case notes were reviewed and data collated on the date and institution of primary arthroplasty, procedures undertaken at our institution, microbiology and bone loss post first stage, serological markers (C-reactive protein, ESR) prior to second stage and outcome.

During this three year period we performed 430 knee revision operations. 51 were in the presence of deep chronic infection. 90% were referred from other hospitals. Overall infection was successfully eradicated in 69%.

Nineteen patients underwent repeat two-stage and overall eleven (58%) patients had successful eradication of infection with multiple two-stages. Of these 47% had F3/T3, the highest grading of Anderson Orthopaedic Research Institute bone loss indicating no metaphyseal bone. A further 12% had bicondylar deficiency on the tibia and no femoral metaphyseal bone (F3/T2b).

Multidrug resistance present in 69% and 47% were infected with multiple organisms. All members of the unsuccessful outcome group had at least one multidrug resistant organism compared to 43% in the successful cohort (P=0.0002). Multiple organisms are associated with an unsuccessful outcome (P=0.056).

Serological markers were not significantly different between the successful and unsuccessful outcome groups.

Where the referring hospital had attempted revision and failed, the chance of eradicating infection dropped from 75% to 58% and the rate of above knee amputation was twelve times higher (3% vs. 36%).

Custom constrained, rotating hinge prostheses enable aggressive soft tissue debridement including ligaments. Successful two-stage requires a multidisciplinary approach including tissue viability nurses, microbiologists and plastic surgeons. Where units lack revision expertise this series suggests early referral increases the chance of limb salvage.

Introduction

Optimal results from uncemented total hip arthroplasty (THA) requires the prosthesis to obtain initial stability, restoration of biomechanics, bone contact along the ingrowth surface and uniform stress transfer to the proximal femur. Anatomic variation within the population makes this difficult to reproduce in every patient. To achieve optimal fit and fill of the proximal femur, options are reshaping the canal or creating an implant which precisely fits the patient's anatomy. The former increases bone loss and risks weakening the supporting bone, creating areas of stress concentration or shielding. Computer assisted design-computer assisted manufacture (CAD-CAM) femoral components were designed to overcome these issues. We present the long term results of CAD-CAM femoral components used in primary THA.

Sixty eight consecutive patients underwent proximal humeral replacement with a fixed fulcrum massive endoprosthesis, for tumour, between 1997 and 2007. The mean age was 46 years, (7–87). Ten patients were lost to follow up and 16 patients died. The 42 surviving patients were assessed using the Musculoskeletal Tumour Society (MSTS) Score and the Toronto Extremity Salvage Score (TESS). The mean MSTS score was 72.3% and the mean TESS was 77.2%.

Four of 42 patients received a new constrained humeral liner to reduce the risk of dislocation. This sub group of 4 patients had a mean MSTS score of 77.7% and a mean TESS of 80.0%.

Endoprosthetic replacement for tumour of the proximal humerus using this prosthesis is a reliable operation yielding good functional results without the documented problems of unconstrained prostheses. The performance of this prosthesis is expected to improve further with the new constrained humeral liner.

Percutaneous biopsies can lead to seeding of tumour cells along the biopsy tract.

Correct surgical management requires preoperative identification and excision of the biopsy tract at time of surgery. These tracts become increasingly difficult to identify with time, leading to risk of inadequate excision of the biopsy tract and recurrence of the tumour at the biopsy site. We conducted a prospective study involving 45 patients who had tissue biopsies for bone and soft tissue tumours between February and May 2008. All the biopsies were performed by consultant radiologist under ultrasound or CT guidance. Case note analysis, patient history and examination at the time of surgery were used to collect data. 23 of 45 patients had accurate identification of the biopsy tract by the surgeon at the time of excision. The mean time between biopsy and excision was 52 days (range 6–140). 22 of 45 patients had unidentifiable biopsy site, with the mean time between biopsy and excision being 98 days(range 13–164) p=0.0004(paired t test). All 4 patients who received post-biopsy radiotherapy had unidentifiable biopsy site tract (mean duration 104 days) and 11 of the 18 patients who underwent neoadjuvant chemotherapy had an unidentifiable biopsy tract (mean duration 108 days). We concluded that identification of biopsy site was more difficult after 50 days, especially in patients who underwent radiotherapy and chemotherapy.

Following this study, all the patients who had biopsies of tumours had the site marked with India ink tattoo. We, then prospectively reviewed 36 patients between July and September 2010 who underwent excision of bone and soft tissue tumours and had their biopsy sites marked with India ink tattoo. After needle biopsy, one drop of the dye was applied at the site of the biopsy. This was taken up by capillary action beneath the dermis and remained present until the patient returned for their definitive surgery. The biopsy site was easily identifiable by the patients and the operating surgeon in all 36 patients. The mean time between biopsy and surgery was 77 days (range 10–299 days). Tattooing of the skin enabled the surgeon to accurately excise the biopsy tract along with the tumour. We recommend this technique of tattooing of the biopsy site with India ink, as it is safe, easily recognisable and permits accurate excision of the tract (including the tattoo), therefore preventing biopsy tract recurrence.

Chondral injuries of the knee are extremely common and present a unique therapeutic challenge due to the poor intrinsic healing of articular cartilage. These injuries can lead to significant functional impairment. There are several treatment modalities for articular osteochondral defects, one of which is autologous chondrocyte implantation. Our study evaluates the mid to long term functional outcomes in a cohort of 828 patients who have undergone an autologous chondrocyte implantation procedure (either ACI or MACI), identifying retrospectively factors that may influence their outcome.

The influence of factors including age, sex, presence of osteoarthritis and size and site of lesion have been assessed individually and with multivariate analysis. All patients were assessed using the Bentley Functional Score, Visual Analogue Score and the Cincinnati Functional Score. Assessment were performed pre-operatively and of their status in 2010.

The longest follow-up was 12 years (range 24 to 153 months) with a mean age of 34 years at time of procedure. The mean defect size was 409 mm² (range 64 to 2075 mm²). The distribution of lesions was 51% Medial Femoral Condyle, 12.5% Lateral Femoral Condyle, 18% Patella (single facet), 5% Patella (Multifacet) and 6% Trochlea. 4% had cartilage transplant to multiple sites.

High failure rates were noted in those with previous cartilage regenerative procedures or evidence of early osteoarthritis and those with transplantation to multiple sites.

Autologous chondrocyte implantation is an effective method of decreasing pain and increasing function, however patient selection plays clear role in the success of such procedure.

Chondral injuries of the knee are extremely common and present a unique therapeutic challenge due to the poor intrinsic healing of articular cartilage. These injuries can lead to significant functional impairment. There are several treatment modalities for articular osteochondral defects, one of which is autologous chondrocyte implantation. Our study evaluates the mid to long term functional outcomes in a cohort of 828 patients who have undergone an autologous chondrocyte implantation procedure (either ACI or MACI), identifying retrospectively factors that may influence their outcome.

The influence of factors including age, sex, presence of osteoarthritis and size and site of lesion have been assessed individually and with multivariate analysis. All patients were assessed using the Bentley Functional Score, Visual Analogue Score and the Cincinnati Functional Score. Assessment were performed pre-operatively and of their status in 2010. The majority of patients had several interim scores performed at varying intervals.

The longest follow-up was 12 years (range 24 to 153 months) with a mean age of 34 years at time of procedure. The mean defect size was 486 mm2 (range 64 to 2075 mm2). The distribution of lesions was 51% Medial Femoral Condyle, 12.5% Lateral Femoral Condyle, 18% Patella (single facet), 5% Patella (Multifacet) and 6% Trochlea. 4% had cartilage transplant to multiple sites. 30% failed following this procedure at a mean time of 72 months. 52% patients stated a marked improvement in their functional outcomes within the first two years. 49% stated an excellent result following their procedure.

High failure rate was noted in those with previous cartilage regenerative procedures, transplants occurring on the patella, particularly if involving multifacets. Multiple site cartilage transplantation was also associated with a high failure rate.

Autologous chondrocyte implantation is an effective method of decreasing pain and increasing function, however patient selection plays clear role in the success of such procedure.

Introduction

There is no consensus on the ideal management of young, active patients with disabling coxarthrosis. Within this group, patients with femoral head defects secondary to cysts or avascular necrosis pose particular challenges. Resurfacing arthroplasty is contraindicated and the results of traditional total hip arthroplasty are suboptimal in this group. The BMHR was designed to offer a bone conserving option for these patients. We report the outcome of this device in the short term.

Bizarre parosteal osteochondromatous proliferation (BPOP), or Nora's lesion, is a rare condition characterised by the formation of surface-based osteocartilaginous lesions typically affecting the hands and feet. 22 cases were identified from the records of a regional bone tumour unit, dating from 1985 to 2009. Of 22 cases, 9 lesions involved the long bones of the hand, 7 the long bones of the feet, 1 case originated from a sesamoid bone of the foot and 5 from long bones (radius, ulna, femur [2] and tibia). Age ranged from 6 to 66 (mean: 31.8) and male to female ratio was 1.8:1. Diagnosis was based on combined radiological and histological features, and initial surgical treatment was excision in 21 cases, and 1 amputation. Follow-up ranged from 12–162 months (mean 32). Recurrence occurred in 6 patients (27%), with mean time to recurrence 49 months (range 10–120). 2 of 8 patients with complete resection margins developed recurrence (25%), versus 4 of 14 with marginal or incomplete resection (28%). Given the potential surgical morbidity inherent in resection, our data suggest that there may be a role for a relatively tissue-conserving approach to the excision of these lesions.

Background

It is known that excessive varus alignment of the femoral stem in total hip replacement (THR) creates a sub-optimal biomechanical environment which is associated with increased rates of revision surgery and component wear. Little is known regarding the effect of femoral stem alignment on patient functional outcome.

Introduction

The variability of the endosteal geometry after removal of the femoral component can make proximal fit difficult to achieve with an ‘off the shelf’ prosthesis. Whatever the anatomy of the proximal femur, it is important to achieve immediate stability, preserve bone stock and protect the femur from cortical defects which can lead to subsequent fracture. In revision Total Hip Arthroplasty (THA) this requires a large inventory of modular components. The use of custom computer-assisted design-computer-assisted manufacture (CAD-CAM) components negates this need. Little has been published on the use of custom-made components in revision THA. We report the results of a cohort of patients who underwent revision THA using CAD-CAM femoral components.

Introduction

Metal on metal hip resurfacing arthroplasty (MoM HR) has the highest revision rates according to the UK National Joint Registry. Revisions for lesions associated with soft tissue necrosis (pseudotumors) have been associated with poor outcomes. There is a relative paucity of information on early revision of painful HR prostheses. We present the results of a series of patients who underwent early revision of painful MoM HR procedures.

The surgical treatment of bone tumours can result in large perioperative blood loss due to their large sizes and hypervascularity. Preoperative embolisation has been successfully used to downgrade vascularity, thus reducing perioperative blood loss and its associated complications. Prior to embolization era, blood loss as high as 18,500mL have been reported peri-opratively.

Twenty-six patients with a variety of bone tumours (average size 10.5×7.5×5.5cm), who underwent pre-operative embolisation between 2005 and 2009, were retrospectively studied. The group comprised of 17 females and 9 males. Their mean age was 38 years old. All patients underwent surgical resection within 48 hours of embolization. Mean blood loss was 796mL and required on average 1.1units of blood. We experienced no complications.

Pre-operative arterial embolisation of large, richly vascular bone tumours in anatomically difficult positions, is a safe and effective method of downstaging vascularity and reducing blood loss.

Aims

Revision total hip arthroplasty is a common operation. The MP Link (Waldemar Link, Hamburg, Germany) system is a distally loading, modular, tapered femoral stem component for revision hip surgery. MP Link in revision total hip arthoplasty was investigated clinically, radiologically and with Oxford hip scores.

The aim of this study was to determine whether the clinical outcome of autologous chondrocyte transplantation was dependent on the timing of a high tibial osteotomy in tibio-femoral mal-aligned knees. Between 2000 and 2005, forty-eight patients underwent autologous chondrocyte implantation with HTO performed at varying times relative to the second stage autologous chondrocyte implantation procedure. 24 patients had HTO performed simultaneously with their second stage cartilage transplantation, (the HTO Simultaneous Group). 5 patients had HTO prior to their cartilage procedure, (the HTO pre-ACI Group) and 19 had HTO performed between 1 to 4 years after their second stage cartilage implantation, (the HTO post-ACI Group). There were 29 men and 19 women with a mean age of 37 years (Range 28 to 50) at the time of their second stage procedure.

With average follow-up of 72 months we have demonstrated a significant functional benefit in performing the HTO either prior to or simultaneously with the ACI procedure in the mal-aligned knee. The failure rate in the Post-ACI group was 45% compared to the Pre-ACI and Simultaneous group, with failure rates of 20% and 25%, respectively.

An HTO performed prior to or simultaneously with an autologous chondrocyte implantation procedure in the mal-aligned knee, provides a significant protective effect by reducing the failure rate by approximately 50%.

Background

The position of the hip-joint centre of rotation (HJC) within the pelvis is known to influence functional outcome of total hip replacement (THR). Superior, lateral and posterior relocations of the HJC from anatomical position have been shown to be associated with greater joint reaction forces and a higher incidence of aseptic loosening. In biomechanical models, the maximum force, moment-generating capacity and the range of motion of the major hip muscle groups have been shown to be sensitive to HJC displacement. This clinical study investigated the effect of HJC displacement and acetabular cup inclination angle on functional performance in patients undergoing primary THR.

Introduction

Autologous chondrocyte implantation (ACI) is contra-indicated in a joint rendered unstable by a ruptured anterior cruciate ligament (ACL). We present our experience of ACI repair with ACL reconstruction

It is known that excessive varus alignment of the femoral stem in total hip replacement (THR) creates a sub-optimal biomechanical environment which is associated with increased rates of revision surgery and component wear. Little is known regarding the effect of femoral stem alignment on patient functional outcome.

Articular cartilage implantation (ACI) and associated procedures (MACI = Matrix-assisted cartilage implantation) are now established treatments for osteochondral defects in the knee. The quality of repair in terms of histological appearance is frequently not known, whilst the correlation of histology results with functional outcomes remains undefined. Histological data of the quality of the repair tissue is sparse and a precise classification proved difficult.

This was a single-centre, prospective study. Over 12 years (1998-2010) 406 patients that underwent articular cartilage implantation procedures at our institution (ACI = 170, MACI = 205) had biopsies taken at the 1-2 year interval, in order to assess whether these contained ‘hyaline-like’ cartilage, ‘mixed hyaline-like with fibrocartilage’, fibrocartilage or fibrous tissue alone.

Histological sections of the biopsies were prepared and stained with haematoxylin, eosin and proteoglycan stains and viewed under polarised light. All biopsies were studied by a single histopathologist in a specialist, dedicated musculoskeletal laboratory.

All patients were assessed by the Cincinnati, Bentley and Visual Analogue scores both pre-operatively and at the time of the review.

The findings revealed that 56 patients healed with ‘hyaline-like’ cartilage (14.9%), 103 with ‘mixed’ (27.5%), 179 with fibrocartilage (47.7%) and 37 with fibrous tissue (9.9%).

These findings showed that 42.4% of defects were filled with ‘hyaline-like’ or ‘mixed’ cartilage, with 70% of these achieving a ‘fair’ to ‘excellent’ functional outcome. This was also observed in the fibrocartilage group, where 72% achieved similar results. Predictably 89% of the patients that healed by fibrous tissue had a poor functional outcome.

This study shows that 71% of patients whose osteochondral defects healed by either ‘hyaline-like’, ‘mixed’ or fibrocartilage experienced an improvement in the function. In contrast, only 11% of the patients whose defects filled with fibrous tissue, showed some functional improvement. Additionally, this data indicates the advantage of biopsies in assessing the overall results of cartilage implantation procedures.

Introduction

Following bone tumour resection, lower limb reconstruction results in leg-length discrepancy in skeletally immature patients. Previously, minimally invasive endoprostheses have been associated with a high risk of complications including joint stiffness, nerve injury, aseptic loosening and infection. The purpose of this study was to examine the outcome of the Stanmore non-invasive extendible endoprostheses used in our institution between 2002 and 2009 and compare them with implants used in the past.