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.

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.

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 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.