Periprosthetic fractures (PPF) of the femur following total hip arthroplasty represent a significant complication with a rising incidence. The commonest subtype is Vancouver B2 type, for which revision to a long uncemented tapered fluted stem is a widely accepted management. In this study we compare this procedure to the less commonly performed cement-in-cement revision.

All patients undergoing surgical intervention for a Vancouver B2 femoral PPF in a cemented stem from 2008 – 2018 were identified. We collated patient age, gender, ASA score, BMI, operative time, blood transfusion requirement, change in haemoglobin (Hb) level, length of hospital stay and last Oxford Hip Score (OHS). Radiographic analysis was performed to assess time to fracture union and leg length discrepancy. Complications and survivorship of implant and patients were recorded.

43 uncemented and 29 cement-in-cement revisions were identified. There was no difference in patient demographics between groups. A significantly shorter operative time was found in the cement-in-cement group, but there was no difference in transfusion requirement, Hb change, or length of hospital stay. OHS was comparable between groups. A non-significant increase in overall complication rates was found in the revision uncemented group, with a significantly higher dislocation rate. Time of union was comparable and there were no non-unions in the cement-in-cement group. A greater degree of stem subsidence was found in the uncemented group. There was no difference in any revision surgery required in either group. Three patients in the uncemented group died in the perioperative period, compared to none in the cement-in-cement group.

With appropriate patient selection, both cement-in-cement and long uncemented tapered stem revision represent appropriate treatment options for Vancouver B2 fractures.

Aims

The mobile bearing Oxford unicompartmental knee arthroplasty (OUKA) is recommended to be performed with the leg in the hanging leg (HL) position, and the thigh placed in a stirrup. This comparative cadaveric study assesses implant positioning and intraoperative kinematics of OUKA implanted either in the HL position or in the supine leg (SL) position.

Aims

The purpose of this study was to evaluate whether an innovative templating technique could predict the need for acetabular augmentation during primary total hip arthroplasty for patients with dysplastic hips.

Background

Despite the success of total knee arthroplasty (TKA) restoration of normal function is often not achieved. Soft-tissue balance is a major factor leading to poor outcomes including malalignment, instability, excessive wear, and subluxation. Mechanical ligament balancers only measure the joint space in full extension and at 90° flexion. This study uses a novel electronic ligament balancer to measure the ligament balance in normal knees and in knees after TKA to determine the impact on passive and active kinematics.

Introduction

The effect of each step of medial soft tissue release was assessed taking the expansion strength and patellar condition into account in five fresh frozen normal cadaver specimens.

Background

Despite the success of total knee arthroplasty (TKA) restoration of normal function is often not achieved. Soft tissue balance is a major factor for poor outcomes including malalignment, instability, excessive wear, and subluxation. Computer navigation and robotic-assisted systems have increased the accuracy of prosthetic component placement. On the other hand, soft tissue balancing remains an art, relying on a qualitative feel for the balance of the knee, and is developed over years of practice

Several instruments are available to assist surgeons in estimating soft tissue balance. However, mechanical devices only measure the joint space in full extension and at 90° flexion. Further, because of lack of comprehensive characterization of the ligament balance of healthy knees, surgeons do not have quantitative guidelines relating the stability of an implanted to that of the normal knee. This study measures the ligament balance of normal knees and tests the accuracy of two mechanical distraction instruments and an electronic distraction instrument.

Introduction

Cement in cement revision with preservation of the original cement mantle has become an attractive and commonly practised technique in revision hip surgery. Since introducing this technique to our unit we have used two types of polished tapered stem. We report the clinical and radiological outcomes for cement in cement femoral revisions performed using these prostheses.

Ganz peri-acetabular osteotomy is commonly used to treat symptomatic hip dysplasia. It aims to increase the load bearing contact area of the hip to reduce the risk of subsequent osteoarthritis. In this study we assess the radiographic and clinical results of the procedure since its introduction to our unit.

All patients undergoing Ganz osteotomies at our unit were followed up prospectively. Data collected included patient demographics and pre- and post-operative functional scores (Harris and Non-arthritic hip scores). In addition, acetabular correction was evaluated on pre-and post-operative radiographs (using Centre-Edge angle and Tonnis angle). Complications were also noted.

Overall 50 procedures were performed between 2007 and 2013 with median follow-up of 3 years (1 – 7 years). The majority of patients (90%) were female. Average age at time of surgery was 29 years (16–49). There were significant improvements in pre- and post-operative median functional scores (Modified Harris Hip Score = 49 versus 64, p=0.001), Non-arthritic Hip Score = 42 versus 56, p=0.007). Median Centre Edge Angle improved from 16 degrees pre-operatively (range = 7–31 degrees) to 30 degrees post-operatively (18–33) degrees), p<0.0001. Similarly, pre-operative Tonnis angle improved from 18 degrees (9–38) to 7 degrees (2–14), p<0.0001. Five patients developed post-operative complications: 2 superficial wound infection, 1deep infection requiring hip washout and antibiotic treatment and 2 patients subsequently requiring total hip replacements.

We have shown that the Ganz peri-acetabular osteotomy can be effective for the treatment of painful hip dysplasia improving both functional and radiographic outcomes. However, patient selection is a key factor.

Two major challenges in arthroplasty are obesity and antibiotic resistance. This study was performed to characterise the organisms responsible for deep infection following total hip arthroplasty and to determine if obesity affected the microbiology profile.

A retrospective analysis of the national surgical site infection register was made to obtain data regarding deep infection following 10948 primary total hip arthroplasty (THA) from 1998–2013, with a minimum of 2 year follow-up.

Of all the primary THAs performed, there were 108 deep infections (56 patients had a BMI >30 (obese) and 52 patients <30). There were no significant differences between cardio-respiratory disease, smoking and alcohol status, and diabetes between the 2 groups. Over the last 15 years, staphylococcus aureus continues to be the most frequently isolated organism. Infection with multiple organisms was found exclusively in obese patients. Furthermore, in obese patients, there was a linear increase with methicillin resistant staphylococcus aureus (MRSA) infections and streptococcus viridans.

On this basis, we recommend careful selection of antibiotic therapy in obese patients, rather than empirical therapy, which can be especially important if there is no growth in an infected THA. In addition, a preoperative discussion regarding dental prophylaxis against streptococcus viridans may be warranted.

Postgraduate training in orthopaedics has traditionally been delivered through an apprenticeship model. However, junior doctor working patterns have more recently moved away from a team based structure, potentially affecting training experience. We aimed to compare the perceived quality of training between medical students, junior non-orthopaedic trainees and orthopaedic specialty trainees.

We conducted an anonymous questionnaire of all medical students and trainees rotating through our unit over 24 months. The questionnaire contained 6, 10-point Likert rating scale questions and free text responses. Results were collated and analysed according to training stage.

Of 82 questionnaires distributed, 60 (73%) were completed (18 specialty registrars, 22 junior trainees and 20 medical students). Junior trainees consisted of 8 GPSTs and 14 Foundation Year (FY2) doctors, only one of whom had specifically chosen an orthopaedic placement.

Median Likert rating of training experience was (1 = very poor, 10 = excellent): ST4-ST8 = 8 (range 7–9), ST1-ST3 = 7 (6–9), GPSTs/FY2s = 4 (2–5) and medical students = 8 (7–10). Further analysis of junior non-orthopaedic doctors' training experience showed that placement induction, organisation of formal teaching and opportunities for training out with formal sessions were rated as poor. However, content of delivered teaching was rated highly. Free text responses identified several barriers to training including being too busy on wards and no opportunity for protected teaching.

Our study shows that junior non-orthopaedic trainees feel their training experience during orthopaedic placements is much poorer than orthopaedic trainees and medical students. Time constraints and less team based working patterns may detract from their teaching opportunities. In addition, junior doctors rotating through orthopaedic units now have a wider spectrum of career interests with heterogeneous training needs. Therefore, orthopaedic departments may need to adopt a more targeted training programme that recognises individual training needs if junior doctor training is to improve.

Ganz peri-acetabular osteotomy is commonly used to treat symptomatic hip dysplasia. It aims to increase the load bearing contact area of the hip to reduce the risk of subsequent osteoarthritis. In this study we assess the radiographic and clinical results of the procedure since its introduction to our unit.

All patients undergoing Ganz osteotomies at our unit were followed up prospectively. Data collected included patient demographics and pre- and post-operative functional scores (Harris and Non-arthritic hip scores). In addition, acetabular correction was evaluated on pre-and post-operative radiographs (using Centre-Edge angle and Tonnis angle). Complications were also noted.

Overall 50 procedures were performed between 2007 and 2013 with median follow-up of 3 years (1–7 years). The majority of patients (90%) were female. Average age at time of surgery was 32 years (17–39). There were significant improvements in pre- and post-operative median functional scores (Modified Harris Hip Score = 52 versus 63, p=0.001), Non-arthritic Hip Score = 49 versus 60, p=0.01). Median Centre Edge Angle improved from 15 degrees pre-operatively (range = 8–19 degrees) to 29 degrees post-operatively (22–36 degrees), p=0.02. Similarly, pre-operative Tonnis angle improved from 19 degrees (16–38) to 7 degrees (2–14), p=0.01. Four patients developed post-operative complications: 1 superficial wound infection, 1deep infection requiring hip washout and antibiotic treatment and 2 patients subsequently requiring total hip replacements.

We have shown that the Ganz peri-acetabular osteotomy can be effective for the treatment of painful hip dysplasia improving both functional and radiographic outcomes. However, patient selection is a key factor.

When performing total hip replacements in patients with hip dysplasia, acetabular augmentation may be required to prevent early component failure. Preoperative radiographic templating may help estimate acetabularcomponent coverage but has not previously been shown to predict the need for augmentation.

We developed a simple method to estimate the percentage of acetabular component coverage from pre-operative radiographs (True: False cup ratio). We aimed to evaluate whether this couldpredict the need foracetabular augmentation at primary total hip replacement for patients with dysplastic hips.

We reviewed all patients with hip dysplasia who underwent a primary total hip replacement from 2005–2012. Classification of hip dysplasia (Crowe), centre edge angle (CEA), Sharp and Tonnis angles were determined on pre-operative radiographs for each patient. Templating was performed on anteroposteriorand lateral view hip radiographs to determine the likely percentage of acetabular component coverage using the True: False cup ratio. Patients requiring acetabular augmentation at time of primary total hip arthroplasty were noted.

128 cases were reviewed, 31 (24%) required acetabularaugmentation. Comparison between augmented and non-augmented cases revealed no difference in the mean CEA (p = 0.19), Sharp angles (p = 0.76) or Tonnis angles (p = 0.32). A lower True Cup: False Cup ratio was observed in the augmented groupcompared to the non-augmented group(median = 0.68 vs 0.88, p < 0.01).

Preoperative templating can help predict which dysplastic hips are likely to require acetabular augmentation at primary total hip replacement.

Femoroacetabular impingement (FAI) is the result of abnormal contact/impingement of the femoral head-neck junction and acetabulum during motion. This can be corrected by surgical dislocation (using Ganz's trochanteric osteotomy) and femoral osteochondroplasty +/− acetabular rim resection. Our study aimed to assess the improvement in hip scores following open osteochondroplasty to predict outcomes based on patient characteristics.

This was a retrospective case note analysis of a single surgeon case series over a 4 year period. Inclusion criteria were open osteochondroplasty, complete pre- and post-op hip scores available), Tonnis osteoarthritis grade 0 or 1, with 1 year followup. Data was extracted from electronic and paper case notes for pre- and post-op Modified Harris Hip Scores (MHHS), Non-arthritis Hip Scores (NAHS) and SF-12 general satisfaction scores, as well as baseline patient demographics. Two independent observers used the PACS radiology system to examine x-rays and MRI. SPSS version 19 was used for statistical analysis.

42 patients met the inclusion criteria. There was an overall improvement in hip scores after the procedure. Mean pre-op scores were MHHS 52.5, NAHS 44.0, SF-12 32.1. Mean post-op scores were MHHS 66.1, NAHS 58.7, SF-12 36.4. Therefore mean improvements were seen in MHHS (13.6), NAHS (14.7) and SF-12 (4.3), all significant at p<0.005 when paired t-test was used for analysis. Pearson correlation for subgroup analysis showed no significant correlation of scores with age, centre-edge angle or alpha angles. Furthermore, no significant difference was seen between males and females (independent t test).

Open osteochondroplasty improves symptoms and function based on patient reported outcome measures. Although the mean scores improved, some patients’ scores deteriorated. We have not identified any statistically significant predictors of outcome, and therefore patient selection remains unclear.

Introduction:

Kinematic studies are used to evaluate function and efficacy of various implant designs. Given the large variation between subjects, matched pairs are ideal when comparing competing designs. It is logical to deduce that both limbs in a subject will behave identically during a given motion [1], barring unilateral underlying pathology, thus allowing for the most direct comparison of two designs. It is our goal to determine if this is a valid assumption by assessing whether or not there are significant differences present in the kinematics of left and right knees from the same subject. Gait studies have compared pre-and postoperative implantation kinematics for various pathologies like ACL rupture [2] and osteoarthritis [3, 4]. We designed a study to assess squatting in cadaver specimens.

Introduction:

Subsidence of cementless femoral stems in total hip arthroplasty (THA) has been associated with poor initial fixation and subsequent risk of aspectic loosening. There is limited literature on how subsidence of cementless, proximally porous coated, tapered wedge femoral stems impacts the patient clinically. The aim of our study was to assess whether subsidence with these stems is associated with a decline in clinical function.

Introduction:

Despite over 95% long-term survivorship of TKA, 14–39% of patients express dissatisfaction due to anterior knee pain, mid-flexion instability, reduction in range of flexion, and incomplete return of function. Changing demographics with higher expectations are leading to renewed interest in patient-specific designs with the goal of restoring of normal kinematics.

Improved imaging and image-processing technology coupled with rapid prototyping allow manufacturing of patient-specific cutting guides with individualized femoral and tibial components with articulating surfaces that maximize bony coverage and more closely approximate the natural anatomy. We hypothesized that restoring the articular surface and maintaining medial and lateral condylar offset of the implanted knee to that of the joint before implantation would restore normal knee kinematics. To test this hypothesis we recorded kinematics of patient-specific prostheses implanted using patient-specific cutting guides.

Repeat revision hip replacements can lead to severe bone loss necessitating salvage procedures such as proximal or total femoral replacement. We present medium term outcomes from our experience of the Limb Preservation System (LPS) in patients with failed revision hip arthroplasties.

All patients undergoing proximal femoral or total femoral replacement from 2003–2007 at our unit were reviewed. Data was collected preoperatively and at annual assessment post procedure for a minimum of 5 years. This included clinical review, functional outcome scores (WOMAC, Oxford Hip Score, Harris Hip Score) and radiographic evaluation.

A total of 17 patients underwent femoral replacement (13 proximal, 4 total) using the LPS during the study period. Within this cohort there were 13 males and 4 females with a mean age of 64 years (range 47–86). Median follow up was 7 years (range 5–9 years). Primary diagnoses were DDH (7), Primary OA (5), RA (2), proximal femoral fracture (2) and phocomelia (1). Five patients (29%) required further revision surgery for infection (2 patients) or recurrent dislocations (3 patients). No stems required revision due to aseptic loosening or stem failure at 5–9 years. Compared to preoperative assessment, there was significant improvement in median outcome scores at 5 years (WOMAC increased by 33 points, Oxford hip score by16 points and Harris hip score by 43 points). 82% of patients maintained functional independence at latest review.

The Limb Preservation System offers a salvage procedure for failed revision total hip arthroplasty with significant symptom and functional improvement in most patients at medium term follow up.

Femoroacetabular impingement (FAI) is a significant cause of osteoarthritis in young active individuals but the pathophysiology remains unclear. Increasing mechanistic studies point toward an inflammatory component in OA. This study aimed to characterise inflammatory cell subtypes in FAI by exploring the phenotype and quantification of inflammatory cells in FAI versus OA samples.

Ten samples of labrum were obtained from patients with FAI (confirmed pathology) during open osteochondroplasty or hip arthroscopy. Control samples of labrum were collected from five patients with osteoarthritis undergoing total hip arthroplasty. Labral biopsies were evaluated immunohistochemically by quantifying the presence of macrophages (CD68 and CD202), T cells (CD3), mast cells (mast cell tryptase) and vascular endothelium (CD34).

Labral biopsies obtained from patients with FAI exhibited significantly greater macrophage, mast cell and vascular endothelium expression compared to control samples. The most significant difference was noted in macrophage expression (p<0.01). Further sub typing of macrophages in FAI using CD202 tissue marker revealed and M2 phenotype suggesting that these cells are involved in a regenerate versus a degenerate process. There was a modest but significant correlation between mast cells and CD34 expression (r=0.4, p<0.05) in FAI samples.

We provide evidence for an inflammatory cell infiltrate in femoroacetabular impingement. In particular, we demonstrate significant infiltration of mast cells and macrophages suggesting a role for innate immune pathways in the events that mediate hip impingement. Further mechanistic studies to evaluate the net contribution and hence therapeutic utility of these cellular lineages and their downstream processes may reveal novel therapeutic approaches to the management of early hip impingement.

Vancouver B fractures around a cemented polished tapered stem (CTPS) are often treated with revision arthroplasty. Results of osteosynthesis in these fractures are poor as per current literature. However, the available literature does not distinguish between fractures around CTPS from those around other stems.

The aim of our study was to assess the clinical and radiological outcome of open reduction and internal fixation in Vancouver B fractures around CTPS using a broad non-locking plate.

Patients treated with osteosynthesis between January 1997 and July 2011 were retrospectively reviewed. All underwent direct reduction and stabilisation using cerclage wires before definitive fixation with a broad DCP. Bicortical screw fixation was obtained in the proximal and distal fragments. We defined failure of treatment as revision for any cause.

101 patients (42 men and 59 women, mean age 79) were included. 70 had minimum follow-up of 6 months. 63 of these went on to clinical and radiological union. Three developed infected non-union. 7 had failure of fixation. Lack of anatomical reduction was the commonest predictor of failure followed by inadequate proximal fragment fixation and infection. 14 patients dropped at least 1 mobility grade from their preoperative status.

This is the largest series of a very specific group of periprosthetic fractures treated with osteosynthesis. Patients who develop these fractures are often frail and “high risk” for major revision surgery. We recommend osteosynthesis for patients with Vancouver B periprosthetic fractures around CTPS provided these fractures can be anatomically reduced and adequately fixed.

Introduction

The outcome of periacetabular osteotomy in dysplastic hips is dependent on the absence of pre-operative osteoarthritis [OA]. The purpose of this study was to analyze whether Tonnis grading is a reliable predictor of OA in patients with hip dysplasia.

Reconstruction of an acetabulum following severe bone loss can be challenging. The aim of this study was to determine the outcome of acetabular reconstruction performed using trabecular metal shell for severe bone loss.

Between June 2003 and June 2006 a total of 29 patients with significant acetabular bone stock deficiency underwent revisions using trabacular metal shell. According to Paprosky classification, there were 18 patients with grade IIIA and 11 patients with grade IIIB defects. Nineteen patients required augments to supplement the defects. Functional clinical outcomes were measured by WOMAC and Oxford hip. Detailed radiological assessments were also made.

At most recent follow up (average 5.5 years, range 3.5–8.5) the mean Oxford hip score improved from 12 preoperatively to 27.11 postoperatively and WOMAC score from 17.57 preoperatively to 34.14 postoperatively The osseointegration was 83% according to Moore's classification. There were two reoperations; one was for instability, and one for aseptic loosening. One patient has a chronic infection and one had a periprosthetic fracture, both treated conservatively.

Despite challenges faced with severe preoperative acetabular defects the early results using this technique in Grade III A and B is encouraging.

Introduction

There is much current debate concerning wear and corrosion at the taper junctions of large head total hip replacements, particularly metal-on-metal hips. Is such damage a modern concern or has it always occurred in total hip replacement but not previously noted. To investigate this five explanted V40 Exeter femoral stems (Stryker Howmedica) were obtained following revision surgery at a single centre. In all cases, the 24–26 mm femoral heads were still attached.

Background

The decision to choose CR (cruciate retaining) insert or CS (condylar stabilized) insert during TKA remains a controversial issue. Triathlon CS type has a condylar stabilized insert with an increased anterior lip that can be used in cases where the PCL is sacrificed but a PS insert is not used. The difference of the knee kinematics remains unclear. This study measured knee kinematics of deep knee flexion under load in two insert designs using 2D/3D registration technique.

Femoroacetabular impingement (FAI) is a significant cause of osteoarthritis in young active individuals but the pathophysiology remains unclear. Increasing mechanistic studies point toward an inflammatory component in OA. This study aimed to characterise inflammatory cell subtypes in FAI by exploring the phenotype and quantification of inflammatory cells in FAI versus OA samples.

Ten samples of labrum were obtained from patients with FAI (confirmed pathology) during open osteochondroplasty or hip arthroscopy. Control samples of labrum were collected from five patients with osteoarthritis undergoing total hip arthroplasty. Labral biopsies were evaluated immunohistochemically by quantifying the presence of macrophages (CD68 and CD202), T cells (CD3), mast cells (mast cell tryptase) and vascular endothelium (CD34).

Labral biopsies obtained from patients with FAI exhibited significantly greater macrophage, mast cell and vascular endothelium expression compared to control samples. The most significant difference was noted in macrophage expression (p<0.01). Further sub typing of macrophages in FAI using CD202 tissue marker revealed and M2 phenotype suggesting that these cells are involved in a regenerate versus a degenerate process. There was a modest but significant correlation between mast cells and CD34 expression (r=0.4, p<0.05) in FAI samples.

We provide evidence for an inflammatory cell infiltrate in femoroacetabular impingement. In particular, we demonstrate significant infiltration of mast cells and macrophages suggesting a role for innate immune pathways in the events that mediate hip impingement. Further mechanistic studies to evaluate the net contribution and hence therapeutic utility of these cellular lineages and their downstream processes may reveal novel therapeutic approaches to the management of early hip impingement.

Introduction

It is well known that total knee arthroplasty (TKA) does not preserve normal knee kinematics. This outcome has been attributed to alteration of soft-tissue balance and differences between the geometry of the implant design and the normal articular surfaces. Bicompartmental knee arthroplasty (BKA) has been developed to replace the medial and anterior compartments, while preserving the lateral compartment, the anterior cruciate ligament (ACL), and the posterior cruciate ligament (PCL). In a previous study, we reported that unicompartmental knee arthroplasty did not significantly change knee kinematics and attributed that finding to a combination of preservation of soft-tissue balance and minimal alteration of joint articular geometry (Patil, JBJS, 2007). In the present study, we analyzed the effect of replacing trochlear surface in addition to the medial compartment by implanting cadaver knees with a bicompartmental arthroplasty design. Our hypothesis was that kinematics after BCKA will more closely replicate normal kinematics than kinematics after TKA.

Background

Hemiarthroplasty of the hip involves the replacement of the femoral side of the joint with a metal prosthesis, resulting in metal-on-cartilage articulation. The two most common types of hemiarthroplasty used are the Austin Moore and the Thomson, both of which are available in either Titanium (Ti) or cobalt chromium (CoCr). Hemiarthroplasty may be more cost effective in elderly patients who have lower life expectancy and are less active.

This case series highlights the use of the Ganz approach (trochanteric slide approach) and surgical dislocation for excision of fibrous dysplasia of the femoral neck, pigmented villonodular synovitis and synovial chondromatosis of the hip.

The first patient was a 16-year-old girl, who presented with pain in her hip, having fallen whilst playing football. Investigations revealed a fibrous dysplasia, which was successfully excised returning her to an active lifestyle.

The second patient was a 27-year-old lady, who presented having suffered left hip pain for four years. She was diagnosed with a pigmented villonodular synovitis, which was excised and the patient was able to return to the gym.

The third patient was a 41-year-old lady, who presented after experiencing right hip pain both at night and at rest for a year, without any trauma. She was diagnosed with synovial chondromatosis and returned to all activities of daily living.

The Ganz approach allows safe dislocation of the hip joint without the risk of osteonecrosis of the femoral head. We demonstrate that it is possible to obtain excellent exposure of the femoral neck, head and acetabulum to surgically treat these three tumours of the hip. The surgeon can thus be reassured that complete excision of the tumour has occurred.

This series can recommend the Ganz approach with trochanteric slide and full surgical dislocation of the hip to excise pigmented villonodular synovitis, synovial chondromatosis and fibrous dysplasia of the hip.

Introduction

Aligning the tibial tray is a critical step in total knee arthroplasty (TKA). Malalignment, (especially in varus) has been associated with failure and revision surgery. While the link between varus malalignment and failure has been attributed to increased medial compartmental loading and generation of shear stress, quantitative biomechanical evidence to directly support this mechanism is incomplete. We therefore constructed and validated a finite element model of knee arthroplasty to test the hypothesis that varus malalignment of the tibial tray would increase the risk of tray subsidence.

This case series highlights the use of the Ganz approach and surgical dislocation for excision of fibrous dysplasia of the femoral neck, pigmented villonodular synovitis and synovial chrondromatosis of the hip, which has never been described for use with all three tumours together. These are rare benign tumours, which were found incidentally and required excision.

We demonstrate that it is possible to obtain excellent exposure of the femoral neck, head and acetabulum allowing easy inspection, exploration and debridement of these three tumours of the hip.

Hip resurfacing has generally been used in younger patients with early osteoarthritis of the hip. There has been considerable recent interest in this over the past few years. We conducted a prospective randomised trial comparing 2 hip resurfacing implants, Durom and ASR looking at radiological and clinical outcomes.

Forty-nine patients (78% male) with hip osteoarthritis which met the criteria for hip resurfacing were randomised to receive either a Durom or ASR resurfacing implant. These patients have so far been followed up for a minimum of one year. The groups were comparable in age (p=0.124) and gender (p=0.675). The average age in the ASR group was 54.04 years and in the Durom group it was 51.25.

Radiological views were scrutinised immediately post op and at final follow up so far to look at cup inclination, stem-shaft angle, and acetabular osseointegration.

Clinical outcomes were compared using the Oxford hip scores, WOMAC scores and SF12 scores.

At minimum follow up of 1 year the mean post operative Oxford hip score was not significantly different between the Durom (45.32, SD 3.93) and ASR (43.44, SD 8.44). The mean post operative WOMAC score was also not significantly different between the Durom (52.56, SD 6.06) and ASR (49.63, SD 2.23). There was no difference between the groups with regards to signs of osseointegration from radiological assessment (p=0.368). There were 3 periprosthetic femoral neck fractures (5.7%) and one revision for pain.

We conclude from this trial that there is no difference in the clinical or radiological findings between the Durom and ASR implants.

Background

While in vivo kinematics and forces in the knee have been studied extensively, these are typically measured during controlled activities conducted in an artificial laboratory environment and often do not reflect the natural day-to-day activities of typical patients. We have developed a novel algorithm that together with our electronic tibial component provide unsupervised simultaneous dynamic 3-D kinematics and forces in patients.

The outcome of periacetabular osteotomy in dysplastic hips is dependent on the absence of preoperative osteoarthritis [OA]. The purpose of this study was to analyze whether Tonnis grading is a reliable predictor of OA in patients with hip dysplasia.

Thirty patients were identified who had undergone hip arthroscopy surgery to assess their suitability for periacetabular osteotomy. Radiographs were assessed for anterior centre edge angle, lateral centre edge angle, Tonnis angle and Tonnis grade for OA changes. The radiographic grading of OA was compared with arthroscopic findings.

The objective was to compare vastus lateralis muscle splitting verses muscle sparing surgical approach to proximal femur for fixation of intertrochanteric fracture.

Of the 16 patients in this prospective randomised double blind study 8 were randomised to vastus lateralis muscle splitting and rest to muscle sparing group. Main outcome measurement was assessment of status of vastus lateralis muscle at 2 and 6 weeks using nerve conduction study. Preoperative demographics were identical for both the groups.

There was no statistically significant difference between the groups with regards to velocity, latency, and amplitude. The postoperative haemoglobin drop, heamatocrit, position of the dynamic hip screw and mobility status were identical.

Both clinical and neurophysiological outcome suggest that damage done to vastus lateralis either by splitting or elevating appears to be identical.

The diagnosis and treatment of hip disease in young adults has rapidly evolved over the past ten years. Despite the advancements of improved diagnostic skills and refinement of surgical techniques, the psychosocial impact hip disease has on the young adult has not yet been elucidated.

This observational study aimed to characterise the functional and psychosocial characteristics of a group of patients from our young hip clinic. 49 patients responded to a postal questionnaire which included the Oswestry Disability Index (ODI) and Hospital Anxiety and Depression Scale (HADS). Median age was 20 years (range 16-38) with a gender ratio of 2:1 (female: male). The most common diagnoses were Perthes' disease and developmental hip dysplasia. More than half of our patients had moderate to severe pain based on the Visual Analogue Scale (VAS) and at least a moderate disability based on the ODI. Thirty-two percent of patients were classified as having borderline to abnormal levels of depression and 49% of patients were classified as having borderline to abnormal levels of anxiety based on the HADS. Comparison of the ODI with the VAS and HADS anxiety and depression subscales showed a significant positive correlation (p<0.05). Multiple regression showed the ODI to be a significant predictor of the HADS anxiety and depression scores (regression coefficient 0.13, 95% confidence interval 0.06 to 0.21, p<0.05).

This study highlights the previously unrecognised psychosocial effects of hip disease in the young adult. A questionnaire which includes HADS may be of particular value in screening for depression and anxiety in young people with physical illness. This study also highlights that collaboration with psychologists and other health care providers may be required to achieve a multidisciplinary approach in managing these patients.

Stable ankle fractures can be successfully treated non-operatively with a below knee plaster cast. In some European centres it is standard practice to administer thromboprophylaxis, in the form of low molecular weight heparin, to these patients in order to reduce the risk of deep venous thrombosis (DVT).

The aim of our study was to assess the incidence of DVT in such patients in the absence of any thromboprophylaxis. We designed a prospective study, which was approved by the local ethics committee. We included 100 consecutive patients with ankle fractures treated in a below knee plaster cast. At the time of plaster removal (6 weeks), patients were examined for signs of DVT. A colour doppler duplex ultrasound scan was then performed by one of the two experienced musculoskeletal ultrasound technicians.

We found that 5 patients developed a DVT. Two of these were above knee, involving the superficial femoral vein and popliteal vein respectively. The other three were below knee. None of the patients had any clinical symptoms or signs of DVT. None of the patients developed pulmonary embolism. Of these five patients, four had some predisposing factors for DVT.

The annual incidence of DVT in the normal population is about 0.1%. This can increase to about 4.5% by the age of 75. DVT following hip and knee replacement can occur in 40-80% of cases. Routine thromboprophylaxis may be justified in these patients. However, with a low incidence of 5% following ankle fractures treated in a cast, we believe that routine thromboprophylaxis is not justified.

Introduction

Despite advances in surgical technique and prosthetics there continues to be a number of patients who are dissatisfied with the results of their knee replacement procedure. The outcome after total knee arthroplasty (TKA) has been reported frequently with use of condition-specific measures, but patient satisfaction has not been well studied.

We reviewed 78 femoral and tibial non-unions treated between January 1992 and December 2003. Of these, we classified 41 as complex non-unions, because of infection (22), bone loss or prior failed surgery to produce union. These were treated with Ilizarov frames. 39 of the 41 nonunions healed successfully at a median time of 11 months.

Using the ASAMI scoring system, we had 17 excellent, 14 good, 4 fair and 6 poor bone results. The functional results were excellent in 14, good in 14, fair in 2 and poor in 2. All but 2 patients were extremely satisfied with the results. The average cost of treatment to the treating hospital was approximately £30,000 per patient. In comparison the cost for a patient with a below-knee amputation was £999 per year. This would amount to a cost of £36,000 per patient in their lifetime.

There is therefore not a great difference between the cost of limb salvage and amputation. The difference that exists favours limb salvage, if patient selection can accurately predict the salvage of a useful limb. Early referral to tertiary centres would reduce the morbidity and the prolonged time off work. The results justify the expense but the NHS needs to make financial provision for reconstruction of complex nonunions.

Routinely in TKA, at least one of the cruciate ligaments are sacrificed. The cruciate ligaments excision may have an impact in the stability of the reconstructed knee by virtue of the impact on the gap kinematics. In this study, a selective cutting protocol was designed to quantify the individual contribution of ACL and PCL about the knee by means of a loaded cadaveric model.

Five fresh frozen normal cadaver specimens were used. The femur was fixed to a specially designed machine, and 3D tibial movements relative to the femur and joint gap distances were measured by means of a navigation system from full extension to 140° flexion. The joint was distracted with 10 pounds. The measurement was performed before and after ACL and PCL excision.

Medial gap distance at 90° flexion before and after cruciate ligaments excision was 4.3 ± 2.7 mm (mean ± SD) and 5.1 ± 2.8 mm (p< 0.05) respectively. Cruciate ligaments excision significantly widened the medial and lateral gaps at many flexion angles, and the effect of excision on the gap distance was different between medial and lateral sides especially at 90° knee flexion. Cruciate ligaments excision also significantly influenced knee kinematics. If this varying gap is not accounted for either through implant shape and orientation or through soft tissue adjustments, instability could be the result.

Surgeons should be made aware of the influence of cruciate excision on varus/valgus laxity throughout the range of motion. Design modification of the femoral component may also be necessary in order to obtain optimal stability in deep flexion.

Total knee arthroplasty (TKA) provides relatively pain-free function for patients with end-stage arthritis. However, return to recreational and athletic activities is often restricted based on the potential for long-term wear and damage to the prosthetic components. Advice regarding safe and unsafe activities is typically based on the individual surgeon’s subjective bias. We measured knee forces in vivo during downhill skiing to develop a more scientific rationale for advice on post-TKA activities A TKA patient with the tibial tray instrumented to measure tibial forces was studied at two years postoperatively. Tibial forces were measured for the various phases of downhill skiing on slopes ranging in difficulty from green to black.

Walking on skis to get to the ski lift generated peak forces of 2.1 ± 0.20 xBW (times body weight), cruising on gentle slopes 1.5 ± 0.22 xBW, skating on a flat slope 3.9 ± 0.50 xBW, snowplowing 1.7 ± 0.20 xBW, and coming to a stop 3 ± 0.12 xBW. Carving on steeper slopes generated substantially higher forces: blue slopes (range 6° to 10°), 4.4 ± 0.18 xBW; black slopes (range 15° to 20°), 4.9 ± 0.57 xBW. These forces were compared to peak forces generated by the same patient during level walking: 2.6 ± 0.4 xBW, stationary biking 1.3 ± 0.7 xBW, stair climbing 3.1 ± 0.31 xBW, and jogging 4.3 ± 0.8 xBW.

The forces generated on the knee during recreational skiing vary with activity and level of difficulty. Snow-plowing and cruising on gentle slopes generated lower forces than level walking (comparable to stationary biking). Stopping and skating generated forces comparable to stair climbing. Carving on steeper slopes (blues and blacks) generated forces as high as those seen during jogging. This study provides quantitative results to assist the surgeon in advising the patient regarding postoperative exercise.

The ideal acetabular component is characterised by reliable, long-term fixation with physiological loading of bone and a low rate of wear. Trabecular metal is a porous construct of tantalum which promotes bony ingrowth, has a modulus of elasticity similar to that of cancellous bone, and should be an excellent material for fixation.

Between 2004 and 2006, 55 patients were randomised to receive either a cemented polyethylene or a monobloc trabecular metal acetabular component with a polyethylene articular surface. We measured the peri-prosthetic bone density around the acetabular components for up to two years using dual-energy x-ray absorptiometry.

We found evidence that the cemented acetabular component loaded the acetabular bone centromedially whereas the trabecular metal monobloc loaded the lateral rim and behaved like a hemispherical rigid metal component with regard to loading of the acetabular bone. We suspect that this was due to the peripheral titanium rim used for the mechanism of insertion.

Introduction: To quantify the magnitude and incidence of haemodynamic changes that occurs during the fixation of extracapsular proximal femoral fractures when using either intra-medullary or extra-medullary fixation device.

Methods: A prospective group of 31 patients with extra-capsular proximal femoral fractures were randomised to either fixation using an extra-medullary compression hip screw or an intra-medullary hip screw. All patients received a general anaesthetic adhering to a standardised anaesthetic protocol including invasive blood pressure monitoring and arterial blood gas sampling. Trans-oesophageal Doppler probe and monitor was used to record pre-operative hypovolaemia and peri-operative changes in cardiac output, stroke volume and corrected flow time (FTc – a reflection of left ventricular end diastolic pressure) during placement of implants.

Results: 77% of patients were hypovolaemic preoperatively, which was corrected with an average of 439 mls of colloid replacement fluid. Application of the extra-medullary CHS produced no change in haemodynamic function. However on insertion of the IMHS we found a statistically significant reduction in stroke volume, cardiac output and FTc without changes in pulse rate or mean arterial pressure. The changes were transient with normal cardiac function returning by 5 mins post operatively.

Conclusion: The transient fall in cardiac function during insertion of the intramedullary hip screw may be caused by fat embolism entering the venous circulation. As these changes are not detected with standard non-invasive monitoring we would recommend that intramedullary devices be used with caution in elderly patients who tend to have poor physiological reserve.

Introduction: Aligning the tibial tray is a critical step in total knee arthroplasty (TKA). Malalignment, (especially in varus) has been associated with failure and revision surgery. While the link between varus malalignment and failure has been attributed to increased medial compartmental loading and generation of shear stress, quantitative biomechanical evidence to directly support this mechanism is incomplete. We therefore constructed a finite element model of knee arthroplasty to test the hypothesis that varus malalignment of the tibial tray would increase the risk of tray subsidence.

Methods: Cadaver Testing: Fresh human knees (N = 4) were CT scanned and implanted with a TKA cruciate-retaining tibial tray (Triathlon CR. Stryker Orthopaedics). The specimens were subjected to ISO-recommended knee wear simulation loading for up to 100,000 cycles. Micromotion sensors were mounted between the tray and underlying bone to measure micromotion. In two of the specimens, the application of vertical load was shifted medially to generate a load distribution ratio of 55:45 (medial: lateral) to represent neutral varus-valgus alignment. In the remaining two specimens, a load distribution ratio of 75:25 was generated to represent varus alignment.

Finite element analysis: qCT scans of the tested knees were segmented using MIMICS (Materialise, Belgium). Material properties of bone were spatially assigned after converting bone density to elastic modulus. A finite element model of the tibia implanted with a tibial tray was constructed (Abaqus 6.8, Simulia, Dassault Systèmes). Boundary conditions were applied to simulate experimental mounting conditions and the tray was subjected to a single load cycle representing that applied during cadaver loading.

Results: The two cadaver specimens tested at 55:45 medial:lateral (M:L) force distribution survived the 100,000 cycle test, while both cadaver specimens tested at 75:25 M:L force distribution failed. The finite element model generated distinct differences in compressive strain distribution patterns in the proximal tibia. A threshold of 2000 microstrain was used for fatigue damage in bone under cyclic loading. Both specimens loaded under 75:25 M:L distribution demonstrated substantially larger cortical bone volumes in the proximal tibial cortex that were greater than this fatigue threshold.

Discussion and Conclusion: We validated a finite element model of tibial loading after TKA. Local compressive strains directly correlated with subsidence and failure in cadaver testing. A significantly greater volume of proximal tibial cortical bone was compressed to a strain greater than the fatigue threshold in the varus alignment group, indicating an increased risk for fatigue damage. This model is extremely valuable in studying the effect of surgical alignment, loading, and activity on damage to proximal bone.

Infection following hip arthroplasty although uncommon can have devastating outcomes. Obesity, defined as a BMI of ≥ 30, is a risk factor for infection in this population. Coagulase negative staphylococcus aureus (CNS) is the commonest causative organism isolated from infected arthroplasties. This study was performed to determine if there has been a change in the causative organisms isolated from infected hip arthroplasties and to see if there is a difference in obese patients.

Data on all deep infection following primary and revision hips was obtained from the surgical site infection register from April 1998 to Nov 2007. Case notes were reviewed retrospectively. There were 49 patients with 51 infected arthroplasties; 25 infected Primary THAs and 26 infected Revision THAs. We found a female preponderance in the infected primary and revision THAs (n=30). 63.2% of all patients had a BMI of ≥ 30, compared to only 34.7% of the non infected population (p< 0.0001). Over the period studied, CNS was the most common organism isolated (56.8%) followed by mixed organisms (37.2%) and staphylococcus aureus (25.4%). Multiple organisms were found exclusively in obese patients. In more than half of cases the causative organisms were resistant to more than two antibiotics.

This study shows that over the last 10 years, CNS continues to be the most frequently isolated organism in infected hip arthroplasties. Multiple organisms with multiple antibiotic resistances are common in obese patients. On this basis we recommend that combination antibiotic therapy should be considered in obese patients.

Introduction: Current Literature is sparse with respect to the optimum surgical approach for fixation of a fractured neck of Femur. A cadaveric study has been performed to determine the pattern of innervation of the Vastus Lateralis muscle. Results indicate that a muscle splitting technique may cause more nerve damage than a muscle reflection technique. The purpose of this study was to determine the clinical and neurophysiological effects of two different surgical approaches to the proximal femur.

Methods: Patients were randomised to receive either a Vastus splitting approach or a Vastus reflecting approach to the fractured femoral neck. The contralateral leg was used as the control for neurophysiological investigation. Needle electromyography was performed on both the operated and unoperated limbs within 2 weeks of surgery.

Results: 25 patients were included in the study randomisation. A total of 17 patients completed neurophysiological investigation, 8 in muscle reflection and 9 in muscle splitting groups. There was a significant reduction in femoral nerve conduction velocity compared to the unoperated control side in the muscle split group. This was also the case for amplitude of response measured in the Vastus muscle. The muscle reflection group showed no significant differences in these parameters compared to the unoperated side.

Conclusion: On the basis of the results of this study we recommend a Vastus Lateralis reflecting approach for proximal Femoral fracture fixation. The functional outcome of a muscle splitting approach remains unclear but could be investigated as part of a larger trial.

Introduction: The ideal acetabular component has low wear, permanent fixation and physiological bone loading. Recently trabecular metal has been promoted as reproducing the modulus of trabecular bone with a cementless fixation. The aim of this trial was to see if a monobloc trabecular backed polyethylene acetabular component loaded the pelvis physiologically as a cemented polyethylene component.

Method: Between 2004 and 2006 54 patients were ran-domised to a cemented polyethylene acetabular component versus a monobloc trabecular backed polyethylene acetabular component. The primary outcome measurement was bone density in peri-prosthetic acetabular regions of interest measured preoperatively and post operatively at 6 weeks and 1 year. Secondary outcomes measured were radiographic and functional outcomes (HHS and Oxford score).

Results: Radiographically 8 patients in the trabecular group had a significant gap in zone II which resolved in 6 by 1 year. The cemented group had 3 patients with a radiolucent line (zone 1) at 1 year. HHS and OXFORD scores improved with no significant difference between the groups. Both groups had significant loss of bone density in the ilium and ischium. The trabecular group produced a significant increase in bone density in the superolateral region. The cemented group produced increased bone density in the superomedial region.

Discussions and Conclusions: There is a significant reduction in BMD for both groups in the upper pelvis and ischium in keeping with finite element modelling predictions. The press-fit group relative to the cemented group resulted in decreased BMD in the superomedial peri-prosthetic region. The trabecular monobloc cup therefore behaves more like a rigid cementless shell despite the properties of trabecular metal.

Introduction: Infection following hip arthroplasty although uncommon can have devastating outcomes. Obesity, defined as a BMI of ≥ 30, is a known risk factor for infection in this population. Coagulase negative Staph Aureus (CNS) is the commonest causative organism isolated from infected arthroplasties. This study was performed to determine if there has been a change in the causative organisms isolated from infected hip arthroplasties and to see if there is a difference in obese patients.

Methods: Data on all deep infection following primary and revision hips was obtained from the surgical site infection register from April 1998 to November 2007. All case notes were reviewed retrospectively.

Results: There were 49 patients with 51 infected arthroplasties; 25 infected Primary THAs and 26 infected Revision THAs. We found a female preponderance in the infected primary and revision THAs (n=30). 65.3% of all patients had a BMI of ≥ 30. Over the period studied, Coagulase negative Staph was the most common organism isolated (56.8%) followed by mixed organisms (37.2%) and Staph Aureus (25.4%). Multiple organisms were found exclusively in obese patients. In more than half of cases the causative organisms were resistant to ≥ 2 antibiotics.

Discussion: This study shows that over the last 10 years, CNS continues to be the most frequently isolated organism in infected hip arthroplasties. Multiple organisms with multiple antibiotic resistances are common in obese patients. On this basis we recommend that combination antibiotic therapy should be considered in obese patients.

Introduction: Tutobone is a solvent-preserved cancellous bovine bone substitute. There is little published about its use in humans. We have been using it as a wedge graft to correct deformity in hindfoot fusion surgery.

Aim: To review the outcome following the use of Tutobone in hindfoot fusion and compare it with a control group without Tutobone.

Method: We performed a retrospective review of all hindfoot fusion performed by the senior author (AG) from 1 Sep 2004 to 31 Jan 2008. We excluded all revision procedures for non-union or malunion. A CT or MRI scan was performed to assess union and graft incorporation in the Tutobone patients at more than six months postoperatively. In the control group fusion was assessed with plain radiographs. The difference in proportion of fusion with complete fusion by six months post-operatively was assessed with a Fisher’s exact test

Results: There were eleven patients in the Tutobone group (1 ankle, 7 subtalar and 3 triple fusions) and 35 in the control group (15 ankle, 11 subtalar, 3 pantalar and 6 triple fusions). All Tutobone patients had partial union on CT/MRI scans. The Tutobone graft had not incorporated at a mean time interval of 14 months post surgery. 30 out of 35 control patients had fused by six months and 33 out of 35 controls were fused by 12 months. The rate of complete fusion between the two groups at six months was statistically significant (p< 0.0001). Two Tutobone patients developed an inflammatory reaction at more than six months post fusion. This reaction is not infective and appears to be a reaction to the Tutobone.

Conclusion: Tutobone should not be used in hindfoot fusion surgery.

Idiopathic anterior knee pain (AKP) is common in adolescents and young adults. Most believe that the origin of the problem lies in the patello-femoral joint. Hamstring tightness has also been attributed as an important cause.

The aim of our study was to compare biometric parameters in patients with idiopathic AKP and controls. We also wanted to assess whether there was a difference in the relative electromyographic (EMG) onset times of the medial and lateral hamstrings.

We prospectively recruited patients with idiopathic anterior knee pain in the age group 11 to 25. Patients, but not the control population, had AP, lateral and skyline radiographs taken to rule out other pathology.

We had 34 patients (60 knees) with a minimum one year follow up. There was no difference in the symptoms of patients who attended physiotherapy as compared to those who did not. Patients with knee pain had significantly more hip external rotation (63 deg) as compared to the control (47 deg) group (p=0.001). Patients also had significantly more hamstring tightness (p=0.04).

Surface EMG was recorded (17 patients and controls each) from the medial and lateral hamstrings during 3 repetitions of a maximal voluntary isometric contraction exercise with the knee at 45° of flexion. The lateral hamstrings contracted 48.7 m.sec earlier than the medial hamstrings in patients as compared to controls.

AKP is a multifactorial and self-limiting disorder. Earlier contraction of the lateral hamstrings may cause tibial external rotation and contribute to the symptoms. Our data suggests that physiotherapy did not significantly alter the course of the condition. We believe that increased hip external rotation may contribute to the symptoms by increasing medial facet stress.

Introduction: Several institutes in continental Europe and the US now prescribe low molecular weight heparin for patients with ankle fractures being treated in a below knee plaster cast. Jorgensen et al reported an incidence of deep venous thrombosis (DVT) of up to 20% in patients treated in a cast. However, their study included patients with variable diagnoses, ranging from tendon ruptures to fractures. The aim of our study was to assess the incidence of DVT in patients with ankle fractures that have been treated conservatively in a below knee cast.

Method: We performed an ultrasound scan on patients with conservatively ankle fractures at the time of removal of the cast. The same ultrasound technician performed all the scans. The local regional ethics committee had approved this study.

Results: So far we have performed an ultrasound scan on 98 patients with ankle fractures. We are likely to complete the study in November 2006 (120 patients). We have encountered only 2 below knee DVTs (2.04 %). None of them involved the popliteal vein. Both patients were completely asymptomatic and were full weight bearing in the cast. A repeat scan showed no evidence of progression. None of the patients had an above knee DVT or a pulmonary embolism.

Discussion: The risk of deep venous thrombosis is said to be higher in patients with a plaster cast because of the decreased ability of the calf muscles to pump the venous blood back to the heart. Though some studies have indicated an incidence of up to 20%, the incidence in our population was only about 2%Thus, DVT is a rare event in patients with ankle fractures. Though it is a serious event, its rarity does not justify a blanket prophylaxis regimen for all patients with ankle fractures.