Background

Undisplaced Lisfranc-type injuries are subtle but potentially unstable fracture-dislocations with little known about the natural history. These injuries are often initially managed conservatively due to lack of initial displacement and uncertainty regarding subsequent instability at the tarsometatarsal joints (TMTJ). The aim of this study was to determine the secondary displacement rate and the need for delayed operative intervention in undisplaced Lisfranc injuries that were managed conservatively at initial presentation.

Abstract

Abstract

Abstract

Abstract

Early changes within articular cartilage during human idiopathic osteoarthritis are poorly understood. However alterations to chondrocyte morphology occur with the development of fine cytoplasmic processes and cell clusters, potentially playing a role in cartilage degeneration. The aggrecanase ADAMTS-4 (A disintegrin and metalloproteinase with thrombospondin motifs-4) has been implicated as an important factor in cartilage degradation, so we investigated the relationship between chondrocyte morphology and levels of ADAMTS-4 in both non-degenerate and mildly osteoarthritic human cartilage.

Human femoral heads were obtained following consent from patients undergoing hip arthroplasty following femoral neck fracture. Cartilage explants of normal (grade 0; G0) and mildly osteoarthritic (grade 1; G1) cartilage were labelled with the cytoplasmic dye CMFDA (5-chloromethylfluorescein-diacetate). Explants were cryosectioned (30μm sections), and labelled for ADAMTS-4 by fluorescence immunohistochemistry. Sections were imaged with confocal microscopy, allowing the semi-quantitative analysis of ADAMTS-4 and 3D visualisation of in situ cell morphology.

With cartilage degeneration from G0 to G1, there was a decrease in the proportion of chondrocytes with normal rounded morphology (P<0.001) but an increase in the proportion of cells with processes (P<0.01) and those in clusters (P<0.001;[4(1653)]; femoral heads:cells). Although average levels of ADAMTS-4 for all cells was the same between G0 and G1 (P>0.05), a change was evident in the distribution curves for cell-specific ADAMTS-4 labelling. Cell-by-cell analysis showed that ADAMTS-4 levels were higher in chondrocytes with cytoplasmic processes compared to normal cells (P=0.044) however cells in clusters had lower levels than normal cells (P=0.003;[3(436)]). Preliminary data suggested that ADAMTS-4 levels increased with larger chondrocyte clusters.

These results suggest complex heterogeneous changes to levels of cell-associated ADAMTS-4 with early cartilage degeneration – increasing in cells with processes and initially decreasing in clusters. Increased levels of ADAMTS-4 are likely to produce focal areas of matrix weakness potentially leading to early cartilage degeneration.

Determine the infection risk of nonoperative versus operative repair of extraperitoneal bladder ruptures in patients with pelvic ring injuries. Pelvic ring injuries with extraperitoneal bladder ruptures were identified from a prospective trauma registry at two level 1 trauma centers from 2014 to 2020. Patients, injuries, treatments, and complications were reviewed. Using Fisher's exact test with significance at P value < 0.05, associations between injury treatment and outcomes were determined.

Of the 1127 patients with pelvic ring injuries, 68 (6%) had a concomitant extraperitoneal bladder rupture.

All patients received IV antibiotics for an average of 2.5 days. A suprapubic catheter was placed in 4 patients. Bladder repairs were performed in 55 (81%) patients, 28 of those simultaneous with ORIF anterior pelvic ring. The other 27 bladder repair patients underwent initial ex-lap with bladder repair and on average had pelvic fixation 2.2 days later. Nonoperative management of bladder rupture with prolonged Foley catheterization was used in 13 patients. Improved fracture reduction was noted in the ORIF cohort compared to the closed reduction external fixation cohort (P = 0.04).

There were 5 (7%) deep infections. Deep infection was associated with nonoperative management of bladder rupture (P = 0.003) and use of a suprapubic catheter (P = 0.02). Not repairing the bladder increased odds of infection 17-fold compared to repair (OR 16.9, 95% CI 1.75 – 164, P = 0.01).

Operative repair of extraperitoneal bladder ruptures substantially decreases risk of infection in patients with pelvic ring injuries. ORIF of anterior pelvic ring does not increase risk of infection and results in better reductions compared to closed reduction. Suprapubic catheters should be avoided if possible due to increased infection risk later. Treatment algorithms for pelvic ring injuries with extraperitoneal bladder ruptures should recommend early bladder repair and emphasize anterior pelvic ORIF.

The development of cytoplasmic processes from in situ chondrocytes is a characteristic feature of early osteoarthritis in human cartilage. The processes involve cytoskeletal elements and are distinct from the short primary cilia described in human chondrocytes. Vimentin is an intermediate filament playing an essential structural and signal-transduction role. We determined cellular levels and distribution of vimentin in chondrocytes of different morphologies in non-degenerate and mildly osteoarthritic cartilage.

Femoral heads were obtained after consent from patients undergoing hip arthroplasty following femoral neck fracture. Cartilage explants were graded as non-degenerate (grade 0;G0) or mildly osteoarthritic (grade 1;G1) and labelled with the cytoplasmic dye CMFDA (5-chloromethylfluorescein-diacetate) for cell shape. Explants were cryosectioned and labelled for vimentin by fluorescence immunohistochemistry. In situ chondrocyte morphology was identified by confocal microscopy as either normal (rounded/elliptical) or abnormal (with one or more cytoplasmic process of ≥2µm) and vimentin levels and distribution determined semi-quantitatively and related to chondrocyte morphology.

When all cells in G0 and G1 cartilage were compared, there was no difference between average levels of vimentin per cell (P=0.144)[6(261)];femoral heads:cells). When cells were separated on the basis of morphology, there was no difference between vimentin levels in cells with one or more cytoplasmic process compared to those of normal morphology (P>0.05;[6(261)]). However vimentin levels were much greater at the base of cytoplasmic processes compared to distant areas of the same cells (P=0.021)[5(29)]).

Although overall levels of chondrocyte vimentin do not change in these early stages of osteoarthritis, the formation and structure of these substantial chondrocyte cytoplasmic processes involves changes to its distribution. These morphological changes are similar to those occurring during chondrocyte de-differentiation to fibroblasts reported in osteoarthritis which results in the formation of mechanically-inferior fibro-cartilage. Alterations to chondrocyte vimentin distribution either directly or indirectly may play a role in cartilage degeneration.

Cartilage degeneration and loss are key events in the initiation and progression of osteoarthritis (OA). Changes to chondrocyte volume and morphology (in the form of cytoplasmic processes) and thus cell phenotype are implicated, as they lead to the production of a mechanically-weakened extracellular matrix. The chondrocyte cytoskeleton is intimately linked to cell volume and morphology and hence we have investigated alterations to levels and distribution of chondrocyte F-actin that occur during early OA.

The femoral heads (FH) from hip joints (N=16) were obtained with ethical permission and patient consent following femoral neck fracture. Cartilage was assessed as grade 0 (non-degenerate) and grade 1 (superficial fibrillation) using OARSI criteria. In situ chondrocyte volume and F-actin distribution were assessed using the fluorescent indicators (5-chloromethyl fluorescein diacetate (CMFDA)) and phalloidin, and imaged and quantified by confocal microscopy, Imaris^TM and ImageJ software.

There were no differences between the volume or total F-actin levels of in situ chondrocytes within the superficial zone of grade 0 (n=164 cells) compared to grade 1 (n=145) cartilage (P>0.05). However, a more detailed analysis of phalloidin labelling was performed, which demonstrated significant increases in both intense punctuate (IP) or intense areas (IA) (P<0.0001; P=0.0175 respectively). A preliminary analysis of IP and IA F-actin labelling suggested that while the former did not appear to be associated with changes to chondrocyte morphology, most of the cytoplasmic processes were associated with the presence of IA at the starting point of the protrusion.

These results demonstrate marked changes to F-actin distribution in chondrocytes in the very early stages of cartilage degeneration as occurs in OA. These subtle changes are probably an early indication of a change to the chondrocyte phenotype and thus worthy of further study as they may lead to deleterious alterations to matrix metabolism and ultimately cartilage weakening.

Articular cartilage has poor repair potential and the tissue formed is mechanically incompetent. Mesenchymal stromal cells (MSCs) show chondrogenic properties and the ability to re-grow cartilage, however a viable human model for testing cartilage regeneration and repair is lacking. Here, we describe an ex vivo pre-clinical femoral head model for studying human cartilage repair using MSCs.

Human femoral heads (FHs) were obtained following femoral neck fracture with ethical permission/patient consent and full-depth cartilage wells made using a 3mm biopsy punch. Pancreas-derived mesenchymal stromal cells (P-MSC) were prepared in culture media at ~5000 cells/20µl and added to each well and leakage prevented with fibrin sealant. After 24hrs, the sealant was removed and medium replaced with StemPro^TM chondrogenesis differentiation medium. The FHs were incubated (37^oC;5% CO₂) for 3wks, followed by a further 3wks in standard medium with 10% human serum with regular medium changes throughout. Compared to wells with medium only, A-MSCs produced a thin film across the wells which was excised en-block, fixed with 4% paraformaldehyde and frozen for cryo-sectioning.

The cell/tissue films varied in thickness ranging over 20-440µm (82±21µm; mean±SEM; N=3 FHs). The thickness of MSC films abutting the cartilage wells was variable but generally greater (15-1880µm) than across the wells, suggesting an attachment to native articular cartilage. Staining of the films using safranin O (for glycosaminoglycans; quantified using ImageJ) was variable (3±8%; mean±SEM; N=3) but in one experiment reached 20% of the adjacent cartilage. A preliminary assessment of the repair tissue gave an O'Driscoll score of 10/24 (24 is best).

These preliminary results suggest the ex vivo femoral head model has promise for studying the capacity of MSCs to repair cartilage directly in human tissue, although optimising MSCs to produce hyaline-like tissue is essential.

Supported by the CSO (TCS/17/32).

Abstract

Abstract

Abstract

Abstract

Conventional methods of treating ankle fractures in the elderly are associated with high rates of complication. We describe the results of treating these injuries in 48 frail elderly patients with a long calcaneotalotibial nail.

The mean age of the group was 82 years (61 to 96) and 41 (85%) were women. All were frail, with multiple medical comorbidities and their mean American Society of Anaesthesiologists score was 3 (3 to 4). None could walk independently before their operation. All the fractures were displaced and unstable; the majority (94%, 45 of 48) were low-energy injuries and 40% (19 of 48) were open.

The overall mortality at six months was 35%. Of the surviving patients, 90% returned to their pre-injury level of function. The mean pre- and post-operative Olerud and Molander questionnaire scores were 62 and 57 respectively. Complications included superficial infection (4%, two of 48); deep infection (2%, one of 48); a broken or loose distal locking screw (6%, three of 48); valgus malunion (4%, two of 48); and one below-knee amputation following an unsuccessful vascular operation. There were no cases of nonunion, nail breakage or peri-prosthetic fracture.

A calcaneotalotibial nail is an excellent device for treating an unstable fracture of the ankle in the frail elderly patient. It allows the patient to mobilise immediately and minimises the risk of bone or wound problems. A long nail which crosses the isthmus of the tibia avoids the risk of peri-prosthetic fracture associated with shorter devices.

Cite this article: Bone Joint J 2014; 96-B:817–22.

Introduction

Minimally invasive Achilles tendon repair has recently gained popularity amongst foot and ankle surgeons. This study aims to quantify the risk of sural nerve injury when using the Achillon device (Integra), as well as delineate its anatomical relationship to the Achilles tendon.

The internal fixation of osteochondral fragments in fractures normally utilizes intra-articular screws inserted through a pilot hole drilled into cartilage/bone. This trauma causes cartilage injury leading to chondrocyte death. We have quantified the cell death following cartilage drilling and identified irrigation conditions that can protect chondrocytes. Articular cartilage of bovine metacarpophalangeal joints of 3yr-old cows was irrigated in the presence/absence of saline of various compositions. Holes were then made using a standard 1.5mm drill (Ortho Solutions Ltd.) at 18,000 rpm through the articular cartilage into bone. Osteochondral explants were then harvested and cultured in Dulbecco's Modified Eagle's Medium containing chloromethylfluorescein-di-acetate and propidium iodide (10uM each), to label living chondrocytes green and dead cells red, respectively. Axial images were taken by confocal microscopy and the width of the zone of cell death (ZCD) around the hole determined. With no irrigation, new drills caused a ZCD of 171±25um, which was increased when drills used 50+ times were tested (279±31um;p=0.03). With saline irrigation, the ZCD was reduced for old drills (150±6um;p=0.016) but not for new drills (124±8um) suggesting the heating effect of the old drills caused additional chondrocyte death. However for new drills, the ZCD was further reduced significantly to 82±7um when the osmolarity of the saline irrigation solution was raised to 480mOsm using sucrose. Data are mean±s.e.m., from at least 5 separate experiments each with a minimum of 3 replicates. The results demonstrate a chondroprotective effect of raising the osmolarity of saline used during drilling of cartilage which could be clinically beneficial.

Hip fractures are a major cause of morbidity and mortality in the elderly and are thought to represent an increasing cohort of our patients. It is estimated that the cost of caring for each patient for their hospital admission is €10,000. There is significant regional and international variation in the incidence rates of such injuries, depending on age, sex and ethnic variations in populations. Recent Irish literature would suggest that the rates in Ireland are exponentially increasing while in the US the rate may be decreasing. The length of stay of such patients is also an important issue especially in the current economic environment. The aim of this study was to define the incidence of hip fractures in the South East. The aim was also to examine any changes to their length of stay that have occurred in a 11 years period.

Independent searches of the operating theatre register and the HIPE (hospital in-patient enquiry scheme) database were undertaken for the time period. Population data was obtained from central census office and the HSE South East offices.

The combined incidence of hip fractures in 2008 and 1998 was 96.06 and 100.90 per 100,000 respectively. The male to female ratio in 2008 was 1:2.67, while in 1998 it was 1:3.04. 13% of the patients in 2008 where under 65 years of age, while in 1998 this figure was 8%. In 1998 the mean length of stay was 17.15. By 2008 this had increased to 23.95 days. The dramatic increase in acute hospital length of stay over the period was estimated to have a burden of more than 14 million euros on health board fund.

This study provides data on a large patient group which is of paramount importance. Health service resources can be allocated appropriately in the future in terms of acute and step-down care based on this data set and results.

Purpose

To investigate the effect of obesity on functional outcome following total ankle arthroplasty.

Purpose

Total Ankle Replacement (TAR) is increasingly being offered to patients as an alternative to arthrodesis for the operative management of debilitating end-stage ankle arthritis. The Mobility Total Ankle System is a third-generation design consisting of a three component, cementless, unconstrained, mobile-bearing prosthesis. This study reports the early results of a multi-centre prospective study of the Mobility prosthesis. This is the first such report by independent researchers.

Saline (0.9%) is typically used to rinse joints during osteo-articular surgery. It is not unusual for cartilage to then be exposed to the air of the operating theatre for 1-2hrs, which can lead to chondrocyte death. We have compared the survival of in situ chondrocytes within bovine cartilage which has been rinsed in various solutions or simply drained of synovial fluid (SF) and then allowed to dry, to identify approaches that could reduce chondrocyte death arising from cartilage drying.

Metacarpophalangeal joints from 3yr-old cows were opened under aseptic conditions. The joints were then (a) rinsed with saline (Baxter's Healthcare, Newbury), (b) rinsed with saline+glucose (20mM; both 300mOsm) or (c) drained of SF, and allowed to dry at room temperature. Full depth cartilage explants were taken after 2hrs, placed into Dulbecco's modified Eagle's medium and incubated with CMFDA (5-chloromethyl-fluorescein diacetate; 10microM) and propidium iodide (10microM) for the identification/quantification of living and dead cells respectively by confocal scanning laser microscopy and image analysis.

After 2hrs, the appearance and properties of the cartilage of the drying joints were clearly different. Saline-rinsed cartilage was dark purple and appeared dull with the cartilage difficult to sample. However when the rinsing solution was saline+glucose, or when joints were drained of SF, the cartilage was almost identical to the freshly-opened joint with a pearly-blue, shiny appearance, and cartilage sampling was easy.

Chondrocyte death was markedly increased in saline rinsed/dried joints after 2hrs (21±9% cell death). In contrast, there was no significant (P>0.05) death in saline+glucose rinsed/dried (2±1%) or SF-drained joints (3±2%;means±s.e.m.;n=5). The loss of cartilage wet weight over 2hrs (time=0 taken as 100%) was almost identical between cartilage rinsed in saline (73.6±1.6%), saline + glucose (78.6±1.1%) or SF (75.0±0.2%; data means±s.d.;n=2).

These results suggest that it was not the loss of water per se during cartilage drying that was the key determinant of chondrocyte viability. As chondrocytes are normally anaerobic, the rise in cartilage pO2 which occurs during exposure to air could have a deleterious effect on cell viability however the presence of glucose or SF protects through an anti-oxidant effect.

Intra-articular screw fixation is indicated for internal fixation of large osteochondral fragments secondary to trauma or osteochondritis dissecans. During surgery, orthopaedic drills are used to prepare a hole through which the screw can pass. Previous work has shown that mechanical injury to articular cartilage results in a zone of cell death adjacent to the traumatised articular cartilage (1). Here, we characterise and quantify the margin of in situ chondrocyte death surrounding drill holes and screws (standard cortical and headless compression designs) placed in mature bovine articular cartilage to model the orthopaedic procedure.

Drill holes (1mm) were made through the articular cartilage and bone of intact bovine metacarpophalangeal joints obtained from 3-yr old cows within 12hrs of slaughter. Osteochondral explants (∼1cm square and 2-3mm thick) encompassing the drilled holes in articular cartilage and subchondral bone were harvested using a chisel. Explants were then incubated in Dulbecco's modified Eagle's medium for 45mins with CMFDA (5-chloromethylfluorescein diacetate) and PI (propidium iodide; both at 10micromolar) to identify/quantify living and dead in situ chondrocytes respectively in a consecutive series of axial optical sections using confocal scanning laser microscopy (CLSM).

The drill holes through cartilage appeared to have clearly defined edges with no macroscopic evidence of cartilage splitting. However visualisation of fluorescently-labelled in situ chondrocytes by CLSM demonstrated clear cell death around the periphery of the drilled hole which was 166±19 micrometers in width. This increased with a larger diameter (1.5mm) drill to 450±151 micrometers (all data are means±s.e.m.; n=3). Preliminary experiments indicated that the margin of chondrocyte death around a 1.5mm hole was dramatically increased further by the insertion of screws into pre-drilled holes.

These results suggest that the mechanical trauma associated with cartilage drilling and the insertion of intra-articular screws occurs with marked death of in situ chondrocytes extending into normal cartilage beyond the area occupied by the screw. As chondrocytes are not replaced in mature cartilage, their loss around the hole/screw will mean that the extracellular matrix is not maintained, inevitably leading to cartilage failure.

Introduction

Septic arthritis of the hip in the newborn baby can result in severe long term sequelae in the form of dislocation of the hip, loss of movement and growth disturbance with leg length discrepancy. Reconstructive procedures for this difficult problem have not been satisfactory.

Aim

To compare the results of total knee replacement in a consecutive series of morbidly obese patients (body mass index (BMI) > 40 kg/m²) with a matched group of non-obese (BMI< 30 kg/m²) patients.

Pre-operative co-morbidities such as known coronary artery disease have commonly deemed a patient at ‘high risk’ for primary elective Total Hip Arthroplasty (THA).

We prospectively collected data on 1744 patients who underwent primary elective THA between 1998 and 2004. 273 had a history of cardiac disease defined as a previous hospital admission with a diagnosis of angina pectoris or myocardial infarction. 594 patients had hypertension defined as that requiring treatment with antihypertensives. We also had data on pre-operative age, sex and body mass index (BMI).

There was no statistically significant increase in early mortality at 3 months with a history of cardiac disease or hypertension and this remained so when adjusting for the other factors in a multivariate analysis. Sex or BMI also did not have a statistically significant effect on the risk of death within 3 months. Increasing age was the only significant risk factor for early mortality (P<0.001).

Longer term mortality at 2 and 5 years in relation to these factors was also examined. Statistical analysis revealed that coronary history now showed a highly significant association (P<0.001) with long term mortality, in patients who survived more than 3 months. 95% confidence intervals for percentage mortality at 5 years were 9.7 - 21.7 with a cardiac history compared to 4.8 - 8.8 without a cardiac history. This remained significant (P=0.002) when adjusted for the other factors. Hypertension continued to have no effect, nor did BMI. Age remained a significant risk factor. Females had a slightly lower long term death rate than males, following THA.

The overall long term mortality following THA was less than expected from the normal population, even in the subgroup with a coronary history.

This study will assist clinicians when advising patients seeking primary elective THA, who have one of these common risk factors.

Performing Bilateral Knee replacements simultaneously is a controversial issue with proponents on both sides of the argument. The advantages of simultaneous arthroplasties include the administration of a single anaesthetic, reduced hospital stay and consequent reduced costs. Reuben et al (J. Arthroplasty, 1998) reported a 36% reduction in hospital costs. Patients also have a quicker return to function and Leonard et al (J Arthroplasty 2003) reported a high patient satisfaction rate of 95%.

The primary disadvantages noted in previous studies include an increase in peri operative complications–both cardiac and pulmonary. An increase in mortality figures is perhaps the most serious complication recorded in some studies. Ritter etal (Clin. Orthop. 1997) reported a 30 day mortality rate of 0.99% in bilateral simultaneous TKA as compared to 0.3% in patients who underwent a staged procedure.

Our study comprised a total of 202 patients who underwent bilateral simultaneous total knee replacements at a District General Hospital in Harlow. Harlow is one of the centres involved in the multi centric trials for the PFC Sigma Knee System and is perhaps the only centre in the UK where bilateral simultaneous procedures are carried out in significant numbers. There were 103 males and 99 females. 12 of the patients had Rheumatoid arthritis. 45% of the patients were in the 71–80 years age group, 26% in the 61–70 years age group. The average age across the entire group was 71.3 years. 35% of patients had a BMI of 25–30, 23% a BMI of 30–35, while less than 5% had a BMI of greater than 40. Most patients (44%) were ASA grade 2. The 3 most common co morbidities included hypertension(85%), coronary artery disease(25%) and diabetes mellitus (12%). 90% of the patients had the procedure performed under a General Anaesthetic and Epidural. Tourniquet time ranged from 55–159 minutes. (average 96 minutes). The patella was resurfaced in all patients. Post operatively the average drain collection was 1200 mls(range 7002600mls). Average pre op Hb was 13.8 g/dl, the post op average being 9.7 g/dl. 71% of patients required blood transfusion after surgery (average 2.8 units). Average hospital stay was 12.4 days (range 5–38 days). 6 patients required HDU admission.

Complications: None in 60%; there were 3 deaths in the first 30 days(1.5%), 2 cases of pulmonary embolism(1%); 6 cases of Myocardial Infarction (3%). There were 14 superficial wound infections and 10 patients required wound washouts. An MUA was performed on 8 knees. 2 patients had Revision Knee replacements for infection.

These figures are comparable to those in published literature. We have found Bilateral simultaneous Total Knee replacements to be a safe procedure with quick return to function.

Articular cartilage is attached to subchondral bone but little is known regarding bone-cartilage interactions important for chondrocyte survival. In this study, bovine articular cartilage has been evaluated in vitro to determine if the presence of subchondral bone influences chondrocyte survival. We hypothesised that

Excision of subchondral bone from articular cartilage would increase in situ chondrocyte death in explant culture and,

Articular cartilage explants (n=132) harvested from the metacarpophalangeal joints of three-year old cows (N=12) were placed into three groups:

subchondral bone excised from articular cartilage (Group A)

Explants were cultured in serum-free media over 7 days with or without media changes to assess the effect of potential soluble mediators. Using confocal laser scanning microscopy to image in situ chondrocytes, fluorescent probes to determine cell viability and biochemical assays to detect alterations in the culture media, differences in the chondrocyte responses (cell density, spatial distribution, percentage cell death) and culture medium composition between Groups A, B and C were quantified over time (2.5 hours versus 7 days).

There was no significant change in cell density for Groups A, B and C over 7 days (t-test, p> 0.05). With excision of subchondral bone from articular cartilage (Group A), there was a marked increase in chondrocyte death over 7 days primarily within the superficial zone involving an extensive area of the articular surface (p< 0.05). There was no significant increase in chondrocyte death over the same time period for Groups B and C (p> 0.05). Corresponding increases in the protein content of the culture media for Groups B and C but not for Group A, suggested that the release of soluble factors from subchondral bone may have influenced chondrocyte survival in the superficial zone.

Subchondral bone interacts with articular cartilage in vitro and promotes chondrocyte survival in the superficial zone. These data support the concept of a functional bone-cartilage system in vivo.

0.9% Saline and Hartmann’s are commonly used joint irrigating solutions during articular surgery. The objective of the study was to determine whether the osmolarity of these solutions affects chondrocyte death in mechanically injured articular cartilage.

The osmolarity of 0.9% Saline (285 mOsm) and Hartmann’s (255 mOsm) solutions was varied from 100–600 mOsm by the addition of distilled water or sucrose. Osteochondral explants (rectangular blocks, n=72) harvested from the metacarpophalangeal joints of six different three-year old cows were exposed to prepared solutions of different osmolarity for 2 minutes to allow in situ chondrocytes (cells embedded within their native extracellular matrix) to respond to the altered osmotic environment. Explants were then mechanically injured through the full thickness of articular cartilage with a fresh scalpel and incubated in the same solution for 2.5 hours. Using confocal laser scanning microscopy (CLSM) and fluorescent probes to determine cell viability, percentage cell death (PCD, 100 × number of dead cells/number of dead and live cells) was quantified within the full thickness of mechanically injured articular cartilage as a function of solution osmolarity.

Cell death was localised to the superficial zone (first 100 microns from the articular surface) of injured cartilage for explants exposed to the control 0.9% Saline (285 mOsm) and Hartmann’s (255 mOsm) solutions, with relative sparing of the middle and deep zones (analysis of variance (ANOVA), p< 0.05). Compared to the control explants exposed to 0.9% Saline, PCD in the superficial zone was greatest for the low osmolarity (100 mOsm) saline solution and least for the high osmolarity (600 mOsm) saline solution (ANOVA, p=0.04). PCD in the superficial zone significantly decreased for explants exposed to 600 mOsm solutions of 0.9% Saline and Hartmann’s, compared to their respective control solutions (p< 0.05 for paired comparisons). There was no significant difference in the PCD between 600 mOsm solutions of 0.9% Saline and Hartmann’s (p=0.5).

Increasing the osmolarity of 0.9% Saline and Hartmann’s solutions is chondroprotective in a surgically relevant model of mechanical cartilage injury. These experiments have important clinical relevance for the design of irrigation solutions during arthroscopic and open articular surgery.

Purpose of Study: To assess the safety of our practice of Bilateral Simultaneous Total Knee Replacements.

Methods: We retrospectively reviewed 202 patients (404 knees) who underwent bilateral simultaneous total knee replacements using the DePuy PFC Sigma Cruciate Sacrificing Endoprosthesis between January 2000 and January 2006. There were 103 males and 99 females with an average age of 71.3 years (range 41–90 years) included. Indication for surgery was Osteoarthritis in 190 patients and Rheumatoid Arthritis in 12 patients. All patients were reviewed at 6 weeks, 1 year and then yearly post surgery.

Results: The average hospital stay was 12.4 days (range 5–38 days) with 6 patients needing HDUadmission post surgery. The average observed blood loss in the drains post surgery was 1200ml (700–2600ml) with an average drop in Haemoglobin of 4.1%, 71% of patients needed a blood transfusion post surgery. Two patients (0.99%) developed a deep vein thrombosis and 2 patients (0.99%) developed a pulmonary embolus.3 (1.48%) deaths were encountered in the immediate post operative period (within 30 days of surgery) and 6 (2.9%) patients suffered a myocardial infarct post surgery.14 (6.9%) patients developed a superficial wound infection of which 10(4.9%) needed a formal washout. 8(3.96%)knees needed a manipulation under anaesthesia for a poor range of movement, and 2(.99%) needed revision total knee replacement for infection.

Conclusion: Bilateral simultaneous total knee replacement is a safe procedure in our experience Complication rates observed comparable to published literature on the subject

Preoperative co-morbidities such as known coronary artery disease have commonly deemed a patient at ‘high risk’ for primary elective Total Hip Arthroplasty (THA). We prospectively collected data on 1744 patients who underwent primary elective THA between 1998 and 2004. 273 had a history of cardiac disease defined as a previous hospital admission with a diagnosis of angina pectoris or myocardial infarction. 594 patients had hypertension defined as that requiring treatment with antihypertensives.

We also had data on preoperative age, sex and body mass index (BMI).

There was no statistically significant increase in early mortality at 3 months with a history of cardiac disease or hypertension and this remained so when adjusting for the other factors in a multivariate analysis. Sex or BMI also did not have a statistically significant effect on the risk of death within 3 months. Increasing age was the only significant risk factor for early mortality (P< 0.001).

Longer term mortality at 2 and 5 years in relation to these factors was also examined. Statistical analysis revealed that coronary history now showed a highly significant association (P< 0.001) with long term mortality, in patients who survived more than 3 months. 95% confidence intervals for percentage mortality at 5 years were 9.7 – 21.7 with a cardiac history compared to 4.8 – 8.8 without a cardiac history. This remained significant (P=0.002) when adjusted for the other factors. Hypertension continued to have no effect, as did BMI. Age remained a significant risk factor. Females had a slightly lower long term death rate than males, following THA.

The overall long term mortality following THA was less than expected from the normal population, even in the subgroup with a coronary history.

This study will assist clinicians when advising patients seeking primary elective THA, who have one of these common risk factors.

In order to eliminate the “conflict” that can occur with physiological roll back of the femur on the tibia, most modern knee arthroplasty prostheses are designed to have little conformity between the femoral and tibial surfaces. However, a consequence of this design is paradoxical anterior sliding of the femur on tibia, which can result in clinically significant gait abnormalities. Recent studies show that during movement of the knee, the medial side remains very nearly stable like a ball-in-socket joint, whilst the lateral side moves front to back, rotating around the centre of the medial side. A total knee joint prosthesis designed with these same kinematics may therefore be advantageous. The objective of this study was to investigate the hypothesis that the increased constraint of a medial pivot knee promotes earlier loosening of the prosthesis.

METHODS: This was a retrospective radiographic cohort study. Using our unit’s knee arthroplasty database, all patients with a Freeman-Samuelson 1000 knee arthroplasty (medial pivot design) or a Freeman-Samuelson Modular knee arthroplasty with a minimum follow-up of 2 years were identified, and matched as closely as possible for age, length of follow-up and pre-operative diagnosis (Osteoarthritis, Rheumatoid arthritis or Post-traumatic arthritis). This was a single surgeon series using a standard surgical approach with a posterior cruciate sacrificing technique. Standardised anteroposterior and lateral radiographs taken postoperatively, at 6 months, 1 year and then at yearly intervals, were examined systematically and independently of the senior surgeon (GS). Component migration and radiolucent line scores were allocated as recommended by the Knee Society.

RESULTS: Group 1 (n=55),–Freeman Samuelson Modular design, mean age–70.3 years, mean length of follow-up–4.5 years. Group 2 (n=48),–Freeman Samuelson 1000 design (Medial pivot), mean age–70.4 years, mean length of follow-up–4.3 years. There were no failures in group 1. There was one failure requiring revision of the femoral component in group 2. Radiolucent lines were more prominent and frequent in the tibia, particularly under the medial and lateral plateau’s (KSS zone 1 and 6). There was no significant difference in the overall radiolucent line scores between the two groups (p=0.39, Mann Whitney U test). Similarly we found no difference between radiolucent line progression in the specific tibial zones (1–6 KSS system). Radiolucent lines in the femur were infrequent and insignificant.

CONCLUSION: We found no statistically significant difference between the two designs of knee prosthesis in terms of either total radiolucent line score or rate of radiolucent line progression. The increased constraint of the medial pivot knee prosthesis does not appear to result in an increased incidence of radiographic loosening.

Dedifferentiated chordoma is a rare and aggressive variant of the conventional tumour in which an area undergoes transformation to a high-grade lesion, typically fibrous histiocytoma, fibrosarcoma, and rarely, osteosarcoma or rhabdomyosarcoma. The dedifferentiated component dictates overall survival, with smaller areas of dedifferentiation carrying a more favourable prognosis. Although it is more commonly diagnosed in recurrences and following radiotherapy, there have been a few reports of spontaneous development. We describe four such cases, which were diagnosed de novo following primary excision, and discuss the associated clinical and radiological features.

We undertook a prospective randomised controlled trial to investigate the efficacy of autologous retransfusion drains in reducing the need for allogenic blood requirement after unilateral total knee replacement. We also monitored the incidence of post-operative complications. There were 86 patients in the control group, receiving standard care with a vacuum drain, and 92 who received an autologous drain and were retransfused postoperatively. Following serial haemoglobin measurements at 24, 48 and 72 hours, we found no difference in the need for allogenic blood between the two groups (control group 15.1%, retransfusion group 13% (p = 0.439)). The incidence of post-operative complications, such as wound infection, deep-vein thrombosis and chest infection, was also comparable between the groups. There were no adverse reactions associated with the retransfusion of autologous blood.

Based on this study, the cost-effectiveness and continued use of autologous drains in total knee replacement should be questioned.

Endoprosthetic reconstruction as a form of limb salvage in the management of malignant disease is common. We present our experience with custom-made distal femoral replacement as a form of limb salvage in the absence of malignancy.

49 cases of distal femoral replacement were identified using the unit database. There were 18 males and 31 females, with a mean age at operation of 62.3 years (range 26–86). There were 29 cases of failed total knee replacements, 8 cases of fracture associated with bone loss, non-union or deformity, 7 periprosthetic fractures, 3 aneurysmal bone cysts, and one case each of avascular necrosis and Gorham’s disease. Clinical and radiographic review of all available patients, including a functional assessment with the Musculoskeletal Tumour Society (MSTS) Score and Toronto Extremity Salvage (TES) score was undertaken.

The average follow-up was 5.4 years (range 1 to 29 years). Three types of endoprosthesis were used, rotating hinge, fixed hinge and arthrodesis prosthesis. One patient required amputation at 2 months following post-operative wound infection with methicillin-resistant staphylococcus aureus and subsequent inability to provide adequate soft tissue coverage. There was one revision at 16 months for deep prosthetic infection. 21 patients were available for functional follow-up. The mean MSTS score was 63.7 (range 16.0–86.7) and the mean TES score was 59.4 (range 9.4–87.5).

Custom-made distal femoral replacements have an established role in limb-salvage surgery for malignant disease. This series demonstrates the reconstructive capability of custom prostheses in non-malignant disease, where deformity causes functional embarrassment or when massive bone loss would normally lead to amputation.

The purpose of this study was to determine whether the low rate of mechanical loosening of the SMILES rotating hinge distal femoral endoprosthesis relates to the hydroxyapatite (HA)-coated, grooved collar of the femoral component.

A database was used to identify two groups of cases of primary distal femoral replacement with a custom-designed and manufactured SMILES endoprosthesis at our unit; those with the collared femoral component (“collar group”), and those without a collar (“non-collargroup”). From these two groups, patients were pair-matched for age and length of bone resection. A retrospective review of serial biplanar pairs of radiographs of each patient, assessing radiolucent lines and extracortical bone pedicle.

11 matched pairs were identified, (14 females, 8 males), with a mean age of 36 years, (range 16–66). The pathology was primary bone tumour in 20 cases, (17 malignant, 3 benign), and metastatic disease in 2 cases. Mean length of follow-up was 85 months, (range 27–122). Radiolucent line score (RLS) progression over time was significantly lower in the collar group, (0.01 vs 0.73, p=0.001) (fig. 1 & 2), as was the mean final RLS, (2.72 vs 7.81, p=0.02). Mean RLS per radiographic quadrant was 0.56 in cases in which a bony pedicle was ingrown onto the prosthesis, (exclusively in the collared-group), 2.41 in cases in which the pedicle was not ingrown, (most prevalent in the non-collared group), and 1.02 in those cases without any pedicle formation, (ANOVA analysis, p=0.0002).

This study demonstrates that the HA-coated, grooved collar significantly reduces the progression of radiolucent lines, and consequently the overall RLS, explaining the reduced rate of mechanical loosening of the collared endoprosthesis. A bony pedicle that does not incorporate onto the prosthesis surface may be associated with an increase in radiographic loosening.

The purpose of this study was to evaluate the results of custom-made endoprosthetic reconstruction for both tumourous and non-tumourous conditions around the elbow joint.

28 consecutive cases of endoprosthetic elbow reconstruction, performed between 1989 and 2003, were identified using the unit database. There were 12 males and 16 females, with a mean age 48.9 years, (range 14–84). There were 16 cases of malignant tumour (10 primary, 6 secondary), 3 cases of benign tumour (one each of giant cell tumour, osteoblastoma and pigmented villonodular synovitis) and 10 non-oncological cases, (5 cases of fracture, 3 failed total elbow replacements and 1 infected synostosis). A distal humeral prosthesis was used in 16 patients, distal humeral and proximal ulna in 10 patients, proximal ulna with a humeral component in one patient and proximal radial replacement in one patient. Clinical and radiographic review of all available patients, including a functional assessment with The Toronto Extremity Salvage score (TESS) was undertaken.

28 consecutive cases of endoprosthetic elbow reconstruction, performed between 1989 and 2003, were identified using the unit database. There were 12 males and 16 females, with a mean age 48.9 years, (range 14–84). There were 16 cases of malignant tumour (10 primary, 6 secondary), 3 cases of benign tumour (one each of giant cell tumour, osteoblastoma and pigmented villonodular synovitis) and 10 non-oncological cases, (5 cases of fracture, 3 failed total elbow replacements and 1 infected synostosis). A distal humeral prosthesis was used in 16 patients, distal humeral and proximal ulna in 10 patients, proximal ulna with a humeral component in one patient and proximal radial replacement in one patient. Clinical and radiographic review of all available patients, including a functional assessment with The Toronto Extremity Salvage score (TESS) was undertaken.

Endoprosthetic reconstruction around the elbow joint is effective in a wide range of pathologies, allowing in most cases a reasonable level of function, even following two-stage revision for infection.

Introduction: The Depuy Pressed Fit Condylar (PFC) total knee arthroplasty (TKA) is well established with reported 10-year survival rates of 93–97%. The PFC was modified, leading to the introduction of the Sigma TKA in 1997. The theoretical advantages of the Sigma system include increased contact area between the femoral component and the tibial insert. We report the first 5-year clinical and radiographic follow-up data for the Sigma TKA.

Methods: Over a ten-month period, 211 Sigma TKAs were performed in 179 patients. Patients were seen at a specialist nurse-led clinic at admission and at 6 months, 18 months, 3 years and 5 years after surgery. Data were recorded prospectively at each visit. Radiographs were obtained at the 5-year follow-up appointment.

Results: Of 211 knees, 187 (150 patients) were alive at 5 years. 5 were lost to follow up. 5 knees (2.4%) were revised: 4 for infection and 1 underwent change of polyethylene insert at 4.9 years. 5-year survival with an endpoint of revision for any reason was 97.4%; with an endpoint of revision for aseptic loosening it was 99.5%. The median American Knee Society score was 93/100 at 5 years compared with 25/100 at admission. Of 145 radiographs, 17 (11.7%) showed radiolucent lines. None showed radiographic loosening of either component. 28 (19.3%) had alignment outside the range of 7±3° valgus.

Discussion: These results suggest that the Sigma TKA gives excellent clinical results after five years. Further follow-up studies are required to see if this performance is maintained in the long term.

Background: Autologous chondrocyte implantation (ACI) was introduced over 15 years ago as a treatment for full-thickness chondral defects in the knee. Current understanding of ACI graft morphology and maturation in humans is limited. The aims of this study were determine the incidence of hyaline-like repair following ACI, and to clarify the relationship between repair morphology and clinical outcome.

Methods: A retrospective review of 194 ACI graft biopsies from 180 patients, and their clinical outcome was conducted. 154 Biopsies were performed 1 year after implantation and 40 biopsies were performed at 2 years. Three techniques of ACI implantation were used; Collagen covered ACI (ACI-C), periosteum covered ACI (ACI-P) and Matrix-Induced ACI (MACI).

Results: At 1 year, hyaline repair tissue was found in 48 (53%) ACI-C grafts, 7 (44%) ACI-P grafts, and 12 (36%) MACI grafts. The frequency of hyaline tissue found in biopsies performed at 2 years (84%) was significantly higher than those performed at 1 year (48.6%), p=0.0001, suggesting that grafts continue to remodel after the first year post implantation.

Clinical outcomes during the first two postoperative years did not vary according to repair morphology type, though hyaline repair was associated with better clinical outcomes beyond 2 years; At 1 year, good to excellent clinical scores were observed in 29 (78.4%) patients with hyaline-like repair, 23 (76.7%) patients with fibrohyaline repair, and 54 (74.0%) patients with fibrocartilage repair. By years 3 and 4 post-implantation, clinical scores further improved in patients with hyaline-like repair yet declined in those with fibrocartilage and fibrohyaline. The difference was significant at 3 years though not at 4 due to the small number of cases.

Conclusions: Achieving hyaline-like repair is critical to the longevity of cartilage repair. The finding of hyaline-like cartilage or fibrohyaline cartilage in 31 of 37 biopsies (84%) performed after 2 years is therefore encouraging and supports further use of the ACI technique.

Introduction To assess five-year survivorship and clinical outcome following unicompartmental knee replacement (UKR) and total knee replacement (TKR) in pre-operatively matched patient groups.

Methods From a prospective database of over 600 patients undergoing knee replacement for osteoarthritis, 70 primary Oxford UKRs (62 patients) were matched pre-operatively with 70 primary PFC TKRs (68 patients) for age, sex, body mass index, knee range of movement and Knee Society Score (KSS). The two groups were assessed at six, eighteen, thirty-six and sixty months following knee replacement and compared for survivorship of the prosthesis (with failure defined as revision for any reason or ‘worst-case’ assuming all patients lost to follow up are revised), post-operative ROM achieved and clinical outcome based on the KSS (reported as separate knee and function score).

Results Three (5 percent) patients in the UKR group and two (3 percent) in the TKR group were unavailable for follow-up at five years. Five-year survivorship based on revision for any reason was 90 percent (95 percent Confidence Interval (CI): 82 to 98) for UKR and 100 percent (95 percent CI: 100 to 100) for TKR (log rank test: p=0.009). The ‘worst-case’ five-year survivorship (assuming all patients lost to follow up are revised) was 85 percent (95 percent CI: 76 to 94) for UKR and 97 percent (95 percent CI: 93 to 100) for TKR (log rank test: p=0.02). The mean post-operative ROM achieved was 105.3 degrees following UKR and 98.3 degrees following TKR (difference 7.0 (95 percent CI 3.3 to 10.6), p< 0.001). There was no difference in the KSS between the two groups for the knee score (difference 0.1 (95 percent CI: −4.3 to 4.5), p=0.9) and function score (difference 2.6 (95 percent CI: −1.7 to 6.9), p=0.2).

Conclusion In comparable patients with osteoarthritis of the knee, survivorship remains superior for TKR at five years. The ROM achieved is greater for UKR but there is no difference in the overall clinical outcome following UKR or TKR. We believe that UKR should only be performed in carefully selected cases because mid-term clinical outcome is similar following UKR or TKR and the complication rate may be higher for UKR.

Aim To compare clinical outcome and complication rates in obese and non-obese patients five years following primary Total Knee Replacement (TKR) for osteoarthritis.

Methods 328 primary TKRs (283 patients) performed between 1995–1999 at a single institution, were followed up prospectively at intervals of 6, 18, 36 and 60 months following surgery and the clinical outcome based on the Knee Society Clinical rating system (subdivided into a Knee Score (KS) and Function score (FS)) recorded at each follow-up interval. The following complications were also recorded: peri-operative mortality, superficial wound infection, deep wound infection, deep vein thrombosis, and revision rate. Three separate comparisons were undertaken by subdividing the study sample into two sub-groups: (1) Group A comprised two subgroups based on body mass index (BMI) – Non-obese (BMI 15–30, 181 TKRs) or Obese (BMI> 30, 147 TKRs). (2) Group B comprised only female patients divided into two sub-groups based on BMI – ‘Non-obese females’ (BMI 15–30, 84 TKRs) or Obese females (BMI> 30, 87 TKRs). (3) Group C comprised two sub-groups based on body weight alone – weight < 100kg (300 TKRs) or weight > 100kg (28 TKRs). A repeated measures split-plot analysis of variance (SPANOVA) was used to evaluate the difference in the clinical outcome at five years between the sub-groups in Group A, B and C. The complication rates were also compared.

Results There was no significant difference in the KS at five years between sub-groups in Group A (p=0.2), B (p=0.2) or C (p=0.3). There was a statistically significant difference in the FS between the subgroups in Group A (p=0.01) and B (p=0.02) but the effect size (relative magnitude of the difference between means) was small (partial eta squared = 0.02 and 0.03, for Group A and B respectively). There was no significant difference in the FS between sub-groups in Group C (p=0.5). There was no significant difference in the complication rate between the sub-groups in Group A, B or C (p> 0.2 for all complications).

Conclusion Obesity does not influence clinical outcome, peri-operative mortality and complication rates five years following TKR. Further studies are required to determine the long-term success of TKR in obese patients.

Introduction and Aims: Several non-comparative studies for uni-compartmental knee replacement (UKR) and total knee replacement (TKR) have been published, but few provide a direct comparison in well-matched patients. The aim of this study was to assess five-year survivorship and the quality of outcome following UKR and TKR in pre-operatively matched patient groups.

Method: From a prospective database of over 600 patients undergoing knee replacement for osteoarthritis, 70 primary medial Oxford UKRs (62 patients) were matched pre-operatively with 70 primary Kinematic TKRs (68 patients) for age, sex, body mass index, active range of movement (ROM) and Knee Society Score (KSS). The two groups were assessed at six, 18, 36 and 60 months following knee replacement and compared for survivorship of the prosthesis (with failure defined as revision for any reason or ‘worst-case’ assuming all patients lost to follow-up are revised), quality of outcome based on the KSS (reported as separate knee and function score) and the ROM achieved.

Results: Three (4%) patients in the UKR group and two (3%) in the TKR group were unavailable for follow-up at five years. Five-year survivorship (Kaplan-Meier methodology) was significantly different for the two groups using revision for any reason as an endpoint – 90% for UKR, 100% for TKR (log-rank test, p=0.01). Assuming all patients lost to follow-up were revised, the ‘worst-case’ five-year survivorship was also significantly different for the two groups – 85% for UKR, 97% for TKR (log-rank test, p=0.02). Analysis of the KSS at six, 18, 36 and 60 months showed no significant difference between the two groups for the knee score (p=0.48) and the function score (p=0.1). The ROM achieved at five years was greater for the UKR group and the difference was statistically significant (UKR: Least square mean 105 degrees, standard error 1.2; TKR: Least square mean 98 degrees, standard error 1.2, p< 0.001).

Conclusion: In comparable patients with osteoarthritis of the knee, survivorship remains superior for TKR at five years. The ROM achieved is greater for UKR, but there is no difference in the overall quality of outcome following UKR or TKR. We believe that UKR should only be performed in carefully selected cases because mid-term functional outcome is similar following UKR or TKR and the complication rate may be higher for UKR.

Study Design: A retrospective case-note study.

Objective: To evaluate causes of delayed admission for patients with spinal injuries.

Subjects: 432 patients admitted between March 1998 and March 2003.

Outcome Measures: Patients were analysed with respect to Injury Severity Score (ISS); date of injury, referral and admission independently and length of hospitalisation. The delays between injury and referral (> 3 days) and between referral and admission (> 7days) were correlated to the length of hospitalisation.

Results: There were 322 males (average age, 38.6 years) and 110 females (average age, 41.8 years), with 108 complete injuries, 115 incomplete and 209 intact. The average time between injury and referral was 5.5 days (range 0–94), and between referral and admission was 10.7 days (range 0–130). 161 patients (37%) experienced a delay between injury and referral, of whom 59 (37%) were subsequently also delayed to admission. The principal reason for delay was the treatment of concurrent injuries. Even patients with complete injuries (15/43) experienced delayed referral. 112 patients (26%) experienced a delay between referral and admission. Principal reasons included the provision of beds and stabilisation of concurrent injuries. We found the delay between referral and admission (p< 0.001), the ISS (p< 0.001) and increasing neurological severity of injury (p< 0.001) to be highly significant factors predisposing to longer hospitalisation.

Conclusions: Delayed admission for patients with spinal injuries is common. Provision of beds being the most common preventable reason for delay following referral. Early liason with a designated spinal injuries unit, especially for patients with cord injury remains vitally important.

Purpose: The purpose of this study was to determine whether the low rate of mechanical loosening of the SMILES rotating hinge distal femoral endoprosthesis relates to the hydroxyapatite (HA)-coated, grooved collar of the femoral component.

Methods and results: A database was used to identify two groups of cases of primary distal femoral replacement with a custom-designed and manufactured SMILES endoprosthesis at our unit; those with the collared femoral component (“collar group”), and those without a collar (“non-collar group”). From these two groups, patients were pair-matched for age and length of bone resection. We performed a retrospective review of serial biplanar pairs of radiographs of each patient, assessing radiolucent lines and extracortical bone pedicle. 11 matched pairs were identified, (14 females, 8 males), with a mean age of 36 years, (range 16–66). The pathology was primary bone tumour in 20 cases, (17 malignant, 3 benign), and metastatic disease in 2 cases. Mean length of follow-up was 85 months, (range 27–122). Radiolucent line score (RLS) progression over time was significantly lower in the collar group, (0.01 vs 0.73, p=0.001) (fig. 1 & 2), as was the mean final RLS, (2.72 vs 7.81, p=0.02). Mean RLS per radiographic quadrant was 0.56 in cases in which a bony pedicle was ingrown onto the prosthesis, (exclusively in the collared-group), 2.41 in cases in which the pedicle was not ingrown, (most prevalent in the non-collared group), and 1.02 in those cases without any pedicle formation, (ANOVA analysis, p=0.0002).

Conclusion: This study demonstrates that the HA-coated, grooved collar significantly reduces the progression of radiolucent lines, and consequently the overall RLS, explaining the reduced rate of mechanical loosening of the SMILES prosthesis. A bony pedicle that does not incorporate onto the prosthesis surface may be associated with an increase in radiographic loosening.

Purpose: To determine the mode of presentation of soft tissue sarcomas to a tertiary centre and the factors associated with a delay in diagnosis and referral.

Methods and Results Between 2000 and 2002, we identified 120 patients with primary soft tissue sarcomas histologically verified at our institution. We reviewed the case histories, referral letters and the histology reports in all cases. The mean age of the study group was 54.5 (range 10 to 91 years). Pathological diagnoses included 32 liposarcomas, 20 malignant fibrous histiocytomas, 19 synovial sarcomas, 12 leiomyosarcomas, 9 fibrosarcomas, 7 spindle cell sarcomas, 4 pleomorphic sarcomas, 3 identified only as high grade soft tissue sarcomas, 3 epithelioid sarcomas, 2 extraosseous Ewing’s sarcomas, 2 malignant round cell tumours and one each of neurofibroma, malignant peripheral nerve sheath tumour, angiosarcoma, alveolar cell sarcoma, extraosseous chondrosarcoma, extraosseous osteosarcoma and clear cell sarcoma of tendon sheath.

Presenting features included a discrete lump or diffuse swelling in 115 patients (95.8%). Pain was not a feature in 69 patients. 3 patients (2.5%) presented with pain alone and 2 patients (1.7%) with varicosities. 116 patients (96.7%) were referred to our unit as a possible soft tissue sarcoma. 4 patients were referred as suspected benign lesions requiring specialist assessment owing to size and location. 46 patients (38.3%) ignored their swelling, resulting in a delay to presentation to their local units. In only 13 patients was pain a feature. These were not considered to be true delayed referrals. 24 patients (20%) experienced a delayed referral to our unit. An alternative diagnosis was suggested in 7 patients by preliminary imaging investigations. A ‘Whoops procedure’ was performed in 14 patients. 3 patients were initially misdiagnosed as muscular injuries, with consequent conservative management resulting in delay.

Conclusion: Soft tissue sarcomas are relatively rare when considered alongside benign soft-tissue lesions. Pain is an infrequent feature, which may result in patients undervaluing their significance and delay their initial presentation to a doctor. Delayed referral is relatively common, although may not always be avoidable. Clinicians should maintain a high level of suspicion when dealing with soft-tissue lesions, with referral to a specialist centre whenever concern exists as to the nature of the lesion.

Purpose: The purpose of this study was to evaluate the results of custom-made endoprosthetic reconstruction for both tumourous and non-tumourous conditions around the elbow joint.

Methods and Results: 28 consecutive cases of endoprosthetic elbow reconstruction, performed between 1989 and 2003, were identified using the unit database. There were 12 males and 16 females, with a mean age of 48.9 years, (range 14–84). There were 16 cases of malignant tumour (10 primary, 6 secondary), 3 cases of benign tumour (one each of giant cell tumour, osteoblastoma and pigmented villonodular synovitis) and 10 non-oncological cases, (5 cases of fracture, 3 failed total elbow replacements and 1 infected synostosis). A distal humeral prosthesis was used in 16 patients, distal humeral and proximal ulna in 10 patients, proximal ulna with a humeral component in one patient and proximal radial replacement in one patient. Clinical and radiographic review of all available patients, including a functional assessment with The Toronto Extremity Salvage (TES) score was undertaken. The average follow-up was 54.9 months (range 5–144). 5 patients with malignancy died of their disease. One patient required amputation for local recurrence at 5 months. There were two revisions at 4 and 7 years for aseptic loosening of the humeral component. Six patients developed deep prosthetic infection at an average of 21 months (range 6–31), necessitating two-stage revision, of which one patient required subsequent excision arthroplasty. There were no cases of permanent nerve palsy. 18 patients (64.3%) were available for functional follow-up. Average flexion deformity was 33 degrees (7–80) and average flexion was 85 degrees (30–133). The mean TES score was 67.8 (range 36.6–96.6). The mean TES score following two-stage revision for infection, (available in 4/5 patients) was 73.9 (range 54.8–91.6).

Conclusion: Custom-made endoprosthetic reconstruction around the elbow joint is effective in a wide range of pathologies, allowing in most cases a reasonable level of function, even following two-stage revision for infection.

Purpose: Dedifferentiated chordomas are a rare and aggressive variant of chordoma. They usually occur in recurrences or following radiotherapy. We describe the rare occurrence of three cases arising de novo within conventional chordoma.

Methods and Results: 29 cases of histopathologically verified chordoma were identified from our unit database. From these, we identified three cases of primary dedifferentiated chordoma. The study group included three men, with an average age of 58.3 years (range 57–61). Presenting features were comparable and included lower back pain and rectal discomfort, with a mass palpable per rectum. A needle biopsy was undertaken in one patient, which demonstrated evidence of a pleomorphic spindle cell tumour without evidence of chordoma. Surgical management involved subtotal sacrectomy, with complete excision achieved in two cases. Histopathological examination confirmed dedifferentiated chordoma with varying amounts of sarcomatous elements in each case. Post-operative radiotherapy was administered in two patients and chemotherapy in one patient. Two patients died at 7 and 10 months following presentation with pulmonary metastases. The third patient remains well and alive at two years follow-up. This patient had a complete excision with post-operative radiotherapy, however histopathological examination revealed only a small focus of the dedifferentiated component.

Conclusions: Dedifferentiated chordoma is a fatal tumour, with metastases and death the likely outcome. Most cases in the literature and the two cases reported in this series, uphold this ominous prognosis. However this may not always hold true. Small areas of dedifferentiation within the chordoma tumour may carry a more favourable prognosis.