Background

Current analysis of unicondylar knee replacements (UKR) by national registries is based on the pooled results of medial and lateral implants. Using data from the National Joint Registry for England and Wales (NJR) we aimed to determine the proportion of lateral UKR implanted, their survival and reason for failure in comparison to medial UKR.

Background

Both surgeon and hospital volume influence patient outcomes following revision knee arthroplasty.

Introduction

High flexion knee arthroplasties have been designed to allow up to 155 degrees flexion and enable high flexion activities such as kneeling and squatting. To date randomised controlled trials have shown no difference in range of movement (ROM) between high flexion and standard designs.

Introduction

Following in-depth analysis of the market leading brand combinations in which we identified implant influences on risk of revision, we compared revision in patients implanted with different categories of hip replacement in order to find implant with the lowest revision risk, once known flawed options were removed.

Purpose

To determine how patient characteristics; health status and pre-operative knee function effect patient reported satisfaction and operative success following total knee replacement (TKR). We hypothesised that a number of patient factors would influence the reported levels of symptomatic improvement (success) and satisfaction and that these two outcomes would represent different aspects of the patient's perception of outcome.

Background

The most appropriate form of chemical thromboprophylaxis following knee replacement is a contentious issue. Most national guidelines recommend the use of low molecular weight Heparin (LMWH) whilst opposing the use of aspirin. We compared thromboembolic events, major haemorrhage and death after knee replacement in patients receiving either aspirin or LMWH.

Purpose

To examine how patients viewed the outcome of their joint replacement at least one year post surgery. Emphasis was placed on investigating the relative influence of ongoing pain and functional limitation on patient satisfaction.

Introduction

We have carried out a 15 year survival analysis of a prospective, randomised trial comparing cemented with cementless fixation of press-fit condylar primary total knee replacements.

Introduction

The purpose of this study was to establish whether men and women with a fragility hip fracture were equally investigated and treated for osteoporosis.

This study evaluates the effect of lower limb post-operative mechanical axis on the long term risk of revision surgery following primary total knee arthroplasty (TKA). The study is relevant because many recent clinical trials have evaluated the optimal surgical technique for accurately aligning components in TKA, despite little evidence that alignment may effect the long-term clinical outcome.

The data used in this study was collected prospectively as part of a randomized control trial comparing the long term survival of cemented versus uncemented TKA. The trial included 501 press-fit condylar posterior cruciate ligament-retaining prostheses performed by the senior author (PJG) or under his direct supervision. The post-operative mechanical axis alignment of the lower limb was measured following TKA using standard AP weight-bearing long leg alignment radiographs. A comparison was made between a well-aligned group with a mechanical axis alignment within 3° of neutral; and a poorly-aligned group whose mechanical axis alignment deviated greater than 3° from neutral. Survival analysis used revision surgery, with exchange of any of the three originally inserted components (femoral, tibial, polyethylene insert), as the endpoint.

There was no loss to follow-up in this study. The minimum follow-up of TKAs in this study was 5.8 years. In the population of TKAs that were followed up at 10 years, 6% (17/270) required revision surgery. There was a significant difference in the rate of revision surgery between the well-aligned group 5% (11/227) and the poorly-aligned group 14% (6/43 p< 0.05)

This study shows that post-operative lower limb mechanical axis alignment is an important determinant of the need for revision surgery at 10 years. Surgeons performing TKA should pay particular attention to the placement of the tibial and femoral components, so that a mechanical axis within 3° of neutral is achieved.

Background: Functional outcome and patient satisfaction after total knee arthroplasty can be variable. Up to 20% of patients have been reported to not be entirely happy with their knee replacement. Psychological factors, in particular illness perception – a patient’s beliefs about their illness – have been found to predict recovery from a range of conditions. Few studies have examined their impact within the orthopaedic context.

Aim: The aim of this study was to investigate the impact of psychological factors, including illness perception, anxiety and depression, on postoperative recovery and functional outcome after total knee arthroplasty.

Patients and Methods: 100 patients from two centres, who underwent a primary total knee arthroplasty for osteoarthritis between 2004 and 2006, took part in this prospective cohort study.

Before surgery patients were asked to complete a psychological questionnaire consisting of Revised Illness Perception Questionnaire (IPQ-r), Hospital Anxiety and Depression Scale (HADS) and Recovery Locus of Control (RLOC). Knee function was assessed preoperatively, at six weeks and one year using Oxford Knee Score (OKS) and range of motion (ROM).

Results: The mean OKS improved significantly at six weeks and further at one year. The mean ROM showed little change in the first six weeks, but was significantly improved at the one-year follow-up.

The psychological factors Consequences, Illness Coherence, Emotional Representation and HADS Anxiety showed a statistically significant correlation with the OKS at six weeks, the factors Consequences and HADS Anxiety and HADS Depression with the OKS at one year. We found no correlation with range of motion at six weeks, but ROM at one year was statistically significantly correlated with the factors Consequences and HADS Depression.

This indicates that patients who believed that their illness had less impact on their personal lives and patients with lower scores on the anxiety and depression scale showed a lower OKS and higher ROM at one year, indicating a better functional outcome.

Hierarchical regression analysis showed that, after controlling for demographics and baseline scores, the factor consequences explained 7% of the variance in ROM at one year. HADS Anxiety and Depression had a significant impact on OKS and accounted for 13.7% of the variance of OKS at one year.

Discussion: Recovery from TKA surgery can be difficult to predict. This study showed that functional outcome can be significantly influenced by psychological factors. These should be taken into account when considering patients for TKA surgery. Improving patient education, looking at home environment and social network as well as addressing anxiety and depression may help to improve overall outcome after TKA surgery.

We report the 15 year follow-up of displaced intra-articular calcaneal fractures from a randomised controlled trial of conservative versus operative treatment. Of the initial study, 46 patients (82%) were still alive and 26 patients (57%) agreed to review.

The clinical outcomes were not different between operative versus conservative treatment. American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot scale: p = 0.11; Foot Function Index (FFI): p = 0.66; and calcaneal fracture score: p = 0.41. The radiological outcomes also were not different between both groups. Böhler’s angle: p = 0.07; height of calcaneum: p = 0.57; and grade of osteoarthritis of the subtalar joint: p = 0.54. There was no correlation between Böhler’s angle and the outcome measures in either group.

The results of this 15 year follow-up of displaced intra-articular calcaneal fracture randomised controlled trial demonstrate similar findings to those at one year follow-up.

We report the results of a prospective randomised controlled clinical trial assessing the radiosterophotogrametric analysis (RSA), clinical and radiological performance of a metal backed and an all-polyethylene tibial cruciate retaining, condylar design, PFC-TKA up to twenty four months.

65 patients were recruited, of which 41 patients were randomised. There were 20 metal backed and 21 all-polyethylene. None were lost to follow-up. There were no significant inter-group demographic differences. We found a significant increase in SF-12 and Oxford knee scores after surgery in both groups. No significant difference was found between the groups in the RSA, SF-12, Oxford Knee score, radiological alignment and range of movement at 6, 12 or 24 months. At 2 years one metal backed implant showed translational migration > 1mm. No all polyethylene implant migrated > 1mm. Further analysis identified possible progressive subsidence of the metal backed implants compared to all-polyethylene implants, although the magnitude of this difference was very small.

We conclude that in the uncomplicated primary total knee arthroplasty, all polyethylene PFC-_ tibial prostheses had equivalent performance to the metal backed counterpart, using RSA as the primary assessment instrument at 24 months. We found no differences between the two designs as assessed by the secondary instruments: SF-12, Oxford knee score, alignment and range of movement at 24 months. Should half of all primary total knee replacements performed in the UK receive an all-polyethylene tibial implant, the estimated annual cost saving would be 21 million pounds per annum.

To identify mechanisms of failure in plate and nail fixation in proximal humerus fractures. 5% of the proximal humerus fractures need surgical fixation, which is carried out, principally, by open reduction and internal fixation or closed reduction and intramedullary nailing. Fixation failure remains a problem. This study answers the mode of failure of these implants regardless of the fracture personality. In-vitro testing of proximal humerus fixation devices was undertaken in 30 simulated osteoporotic bone models. Fracture-line was created at the surgical neck of humerus in all samples and fixed with five fixation devices; three plating and two nailing devices. The samples were subjected to failure under compression and torque. Failure was achieved in all models. Three failure patterns were observed in torque testing:

The two conventional plates Cloverleaf and T-plate behaved similarly, failing due to screw pull-out from both the proximal and distal fragment with a deformed plate.

The failure mode is dependent on implant properties as well, independent of the fracture personality. It is important to recognise the potential points of failure (proximal or distal fragment) when making the choice of implant to avoid fixation failure.

The aim of this study was to determine whether there is a difference in the functional outcome between fixed and mobile bearings in total knee arthroplasty.

120 patients were randomized (computer generated) to receive either a fixed or mobile bearing P.F.C. Sigma total knee replacement. 96 patients were needed to detect a 20° difference in range of motion (ROM) with a significance level of 0.05 and a test power of 0.97. Oxford knee score (OKS) and ROM were assessed independently before and one year after surgery.

Mean ROM and Oxford knee score before and at one year after surgery for both groups are shown as preliminary results for 70 patients (follow-up expected to be completed by March 2006):

There is no statistically significant difference in the mean ROM at one year and in change in ROM between the two groups (p=0.53 and p=0.21 respectively). The findings were similar for Oxford Knee Score at one year and change in Oxford Knee Score (p=0.45 and p=0.82). There was no early aseptic loosening in either group.

The one year results suggest that there is no significant difference in functional outcome measured as ROM and Oxford Knee Score between the two types of bearing. Further follow-up will be carried out to detect any differences in the long term outcome.

Aim: To compare of strength of constructs using the newer and part specific nail systems: Polarus and European Humeral Nail with that using PHILOS and Conventional plate systems in a simulated 2-part fracture of proximal humerus, in an osteoporotic bone model.

Materials and Methods: A Biomechanical laboratory study was undertaken. Third generation composite Humerus model was used, with short e-glass epoxy fibres forming cortex and polyurethane cancellous core. Low-density polyurethane core (1.2gm/cc) was used to simulate an osteoporotic model. Osteotomy at surgical neck of humerus was carried out to create 2-part fracture of proximal humerus. Samples were fixed using one of the implants- the Polarus nail, the European Humeral Nail, PHILOS Plate, Clover Leaf Plate or T-Plate. Following fixation samples were placed in a custom made jig to fix proximal and distal ends without interfering with implants and osteotomy site. All samples were subjected to cyclical torque, torque to failure, cyclical compression and Compression loading to failure.

Results: The two Nail systems that are specifically designed for fixation of proximal humerus fracture provided significantly better fixation in all the test modalities. PHILOS construct shows less plastic deformation in cyclical torque and cyclical compression when compared to the other plates but the 2 nail systems were far superior. Locking screws did not ‘back off’ in any of the experiments involving the Polarus, European Humeral Nail and PHILOS construct, however ordinary screws used with the conventional plates did back off both in ‘torque and compression’ testing.

Conclusions: Polarus and European Humeral Nail constructs provide better stability in torque and compression as compared to PHILOS, which in turn is a more stable construct in comparison to conventional plating devices.

Background: The incidence of proximal humeral fractures is increasing with time. There is continuing debate about the indications for surgical intervention for this relatively common injury. Baseline data on functional outcome is essential in order to study the effect of surgical intervention. Functional outcome scores provide reliable and valid judgments of health status and the benefits of treatment. During our preparation of a study proposal on this topic to the Health Technology Assessment Program recently, we noted the lack of such data on outcome scores in the current literature.

Aim: To assess the functional outcome using the Constant and Oxford scores in patients treated conservatively for proximal humeral fractures.

Methods: We prospectively studied 103 consecutive patients who were treated conservatively for proximal humeral fractures. Patient demographics, fracture type (Neer), hand dominance and comorbidity were recorded. Constant and Oxford shoulder scores were recorded 3 and 12 months post injury.

Results: The average Constant shoulder score for males was significantly higher (better outcome) and the Oxford shoulder score significantly lower (better outcome) as compared to females. The scores were not affected by hand dominance. Although the raw scores tended to be worse with 3 or 4 part fractures the difference in the mean scores between the various Neer fracture types did not reach convential levels of significance.

A trend towards lesser degrees of improvement in the outcome scores was noted with increasing age. The degree of improvement in the outcome scores was not affected by sex, limb dominance or fracture type (Neer’s classification).

Conclusion: This study indicates the average behaviour of the Constant and Oxford scores with conservative treatment of proximal humeral fractures. This data should help with sample size and power calculations when studying interventions for this injury. We hope that this data will provide a baseline to help inform future study designs on proximal humeral fractures.

Aims: To ascertain the efficacy of viscosupplementation with Supartz intra-articular knee injections when used in the absence of a specific protocol for its use.

Methods: Retrospective cohort study using data from a dedicated injection clinic, patient case notes and knee radiographs. Patients received the therapy in the absence of a protocol for its use. Patient’s age, gender, symptoms, walking ability, presence of deformity, medication history, previous injection or surgical intervention, physiotherapy, co-morbidity, date of presentation, delivery of course of supartz injections and indication were recorded. Knee radiographs were analysed using Kellgren and Lawrence grading system. Pain relief and avoidance of surgical intervention (when surgery was an option) were the outcome measures.

Results: 965 intra-articular injections in 193 courses of supartz therapy were given in 143 patients. 45.6% were male and 54.4% were female patients. At presentation, 33.2% patients were able to walk < 1/2 a mile, 35.2% patients 1/2-1 mile and 31.6% > 1 mile. Radiological assessment (using Kellgren and Lawrence grading) showed 2 cases with stage 1 disease, 83(43%) with stage 2, 102(52.3%) with stage 3, and 6 cases with stage 4 disease. The medial compartment was involved in 185 cases (95.9%), the lateral compartment in 44 (22.8 %) and patellofemoral joint (PFJ) was involved in 122 (63.2 %).

Pain relief was obtained in 84/193 cases (43.5%). In 122 cases where the aim was to avoid surgery, this was achieved in 52 cases (42.6%). Success rate decreased with increasing severity of disease (Fisher’s Exact test; p< 0.01). Only 25/122 cases with PFJ involvement had pain relief (21%), compared to 59/71 cases without PFJ involvement (83%), (Chi squared test; χ 2(1)=71.57, p< 0.01). Younger age (< 60 years) is a poor prognostic factor (Chi squared test; χ2(1)= 5.86, p=0.02).

Conclusions: Younger patients and those with PFJ involvement and advanced disease are unlikely to benefit from Supartz intra-articular injection. We consider it inappropriate to use this therapy in the absence of a protocol for its use.

Aims: Does PHILOS (Proximal Humeral Internal Locking system) construct provides better þxation than Clover leaf plate and T-plate in a simulated 2-part fracture of proximal humerus, in an osteoporotic bone model?Materials and Methods: Biomechanical laboratory study. Third generation composite Humerus model was used, with short e-glass epoxy þbres forming cortex and polyurethane cancellous core. Low density polyure-thane core (1.2gm/cc) was used to simulate an osteoporotic model. Osteotomy at surgical neck of humerus was carried out to create 2-part fracture of proximal humerus. Samples were randomised to receive one of the implants. Following þxation samples were placed in a custom made jig to þx proximal and distal ends without interfering with implants and osteotomy site. All samples were subjected to cyclical torque, Torque to failure, Cyclical compression and Compression loading to failure. Results were entered in a database. Results: PHILOS provided signiþcantly better þxation in ÔTorque to failureñ experiment. PHILOS construct shows less plastic deformation in cyclical torque and cyclical compression. Locking screws did not Ôback offñ in any of the experiments involving PHILOS construct, however ordinary screws did back off both in Ôtoque and compressionñ testing. Conclusions: PHILOS construct provides better stability in Torque and compression as compared to conventional plating devices, in an osteoporotic bone model.

The National Institute for Clinical Excellence (NICE), in its “Guidance on the Selection of Prostheses for Primary Total Hip Replacement”, states that a revision rate of 10% or less at ten years should be regarded as the “benchmark” in the selection of prostheses for primary Total Hip Replacement (THR). This paper presents the results of such a study for primary Charnley THR. Methods: All patients undergoing primary Charnley THR during 1990 were prospectively registered with the Trent Regional Arthroplasty Study (TRAS). During 1990, 1198 Charnley THRs were performed on 1152 patients, under the care of 56 consultants, in 18 National Health Service and 6 private hospitals. The cohort contains 39.0% male and 61.0% female patients, with an average age at operation of 69.1years (21–103 years), 19.1% being less than 60 years. At 10 years all surviving patients at 5 years were registered with the ONS to ascertain living patients. These patients were contacted by letter to determine whether or not their THR had been revised. The status of the THR, for non-responding patients, was determined by contacting the patient’s GP through the Contractor Services Agency (CSA). The endpoint was defined as revision surgery to replace an original implant component. Results: At 10 years, the recipients of 438 THRs had died. The recipients of 89 THRs did not respond to the questionnaire at ten years. Implant status at ten years, in living patients was known for 671 of 760 (88.3%) THRs. The ten-year crude revision rate was 44 out of 1198 (3.7%) and cumulative survival rate was 95.5% (95% CI, 93.6% – 96.9%).

Conclusion: This is the first study to assess the survivorship at 10 years for primary Charnley THRs performed in the ‘general setting’ of the NHS as opposed to specialist centres and shows a result well within the NICE benchmark.