Purpose

The aim of this study was to compare the short-term and mid-term outcome of lateral UKRs using a single prosthesis, the AMC Uniglide knee implant.

Introduction

Kneeling ability is better in unicompartmental than total knee arthroplasty. There is also an impression that mobile bearing knees achieve better functional outcome than their fixed bearing cousins in unicompartmental and to a lesser extent total joint arthroplasty. In the UK, the market leading unicompartmental replacement is mobile bearing.

Introduction

Trochlear dysplasia (TD) is still poorly recognised, generally considered uncommon and to present purely as persistent patella dislocation.

Between 1989 and 1992 102 knees adjudged suitable for Unicompartmental replacement (UKR) were randomised to receive either a St Georg Sled UKR or a Kinematic modular total knee replacement (TKR). The early results demonstrated that the UKR group had less complications, and more rapid rehabilitation. At 5 years there were equal failures but the UKR group had more excellent results and a greater range of movement.

Despite this doubt persisted about whether these advantages would be maintained these cases have been followed regularly by a research nurse at 8, 10, 12 years. We now report the final outcome at 15 years. 43 patients (45 knees) have died with all their knees intact. Throughout the review period the Bristol Knee Scores (BKS) of the UKR group have been better and at 15 years 77% and 53% of the surviving UKRs and TKRs achieve an excellent score. 6 TKRs and 4 UKRs have failed during the 15 years of the review.

We aimed to measure cerebral microemboli load during total hip [THA] and knee arthroplasty (TKA) using transcranial Doppler ultrasound (TCD) and to investigate whether cerebral embolic load influences neuropsychiatric outcome. The timing of the microemboli was also related to certain surgical activities to determine if a specific relationship exists and the presence of a patent foramen ovale was investigated.

Patients undergoing primary THA and TKA underwent a battery of ten neuropsychiatric tests pre-operatively and at 6 weeks and 6 months post-operatively. Microembolic load was recorded using TCD onto VHS tape for subsequent analysis. Patent foramen ovale detection was performed using bolus intravenous injection of agitated saline followed by valsalva manoeuvre. The timing of specific surgical steps was recorded for each operation and embolic load calculated for that period. All patients were assessed for quality of life and orthopaedic outcome measures.

Background

Unicompartmental knee replacements (UKR) converted to total knee replacements (TKR) have often been viewed with scepticism because of the perceived difficulty of the revision and because revision procedures generally do less well than primaries.

Introduction

The Bristol Knee Group has prospectively followed the results of over 500 isolated patellofemoral arthroplasties. Initial experience with the Lubinus prosthesis was disappointing. The main causes of failure were mal-tracking and instability leading to excessive polythene button wear and disease progression in the tibio femoral joint.

This experience resulted in the design of a new prosthesis to correct the tracking problems and improve the wear. We have now performed over 425 Avon arthroplasties with a maximum follow-up of 9 years.

Aim: To assess mid to long-term functional and symptomatic outcome after internal fixation of the distal radius.

Methods: All patients operated upon between June 2004 and October 2007 were retrospectively assessed using the ‘Disabilities of arm, shoulder and hand’ (DASH, range 0–100), and Mayo wrist (range 0–100) functional scoring systems. Fractures were classified according to the AO system. All patients were treated in one unit by the same group of surgeons using standard accepted techniques. Revision operations and patients treated at greater than four weeks after injury were excluded. Radiographic analysis of time to union was also performed.

Results: 201 patients underwent surgical fixation of which, 183 patients were contactable for follow up (9% loss). Only these patients were included in the study. Mean age was 62.5 years. Mean follow up time was 30 months. Mean time to surgery was eight days. 74% had good/excellent Mayo and 75% good/excellent DASH scores. 2% of patients had a poor outcome with both scores. 28 % reported no functional or symptomatic deficit. There was a 14% overall complication rate (6% major). Mean time to union was 8.39 weeks. Time to union increased with advancing AO grade. There was no significant difference in scores with regard to postoperative immobilisation, time to surgery, time to follow up, patient age, surgeon grade or fracture type.

Conclusion: This is one of the largest series of its type and the results compare favourably with other published operative and non-operative treatment modalities. This is a safe, reproducible technique with excellent functional outcome and is recommended as the treatment of choice when surgery is indicated for these fractures.

Background: Although many knee surgeons routinely perform unicompartmental replacement (UKR) for medial compartment arthrosis there is still reluctance to perform lateral UKR’s as they are generally thought to be less satisfactory. The purpose of the present study was to prospectively compare the outcome of lateral UKR’s with medial UKR’s using the AMC Uniglide knee implant.

Methods: Between 2002 and 2005, 29 lateral fixed bearing AMC Uniglide UKR’s were performed at our unit. American Knee Society (AKS), Oxford and WOMAC scores were recorded pre-operatively and at two years post-op and compared with the results of 50 medial mobile bearing and 50 medial fixed bearing AMC Uni-glide UKR’s performed during the same time period. Data was acquired by a research nurse and recorded prospectively on the Bristol Knee Database. The mean ages of the patients were: 63 years in the lateral UKR group was, 62 years in the medial mobile bearing group and 69 in the medial fixed bearing group. The groups were equally sex matched with a predominate number of females in each group. There was no difference between the pre-operative scores for the 3 groups.

Results: At one-year review, the 3 groups had similar mean scores: (table removed)

Conclusions: This study suggests that at two years the quality of outcome of Lateral UKR’s is at least equivalent to both fixed and mobile bearing medial compartment UKR’s. However, continued long-term survivorship studies are needed to assess failure rates of Lateral fixed bearing UKR’s and particularly to evaluate progression of arthritis in the medial compartment. The procedure should form part of the knee surgeons’ armamentarium, but the differences in the operative techniques for lateral and medial UKR must be appreciated.

Although good long term results for fixed bearing uni-compartmental knee replacements (UKRs) have been reported mobile bearings predominate in some parts of the world. Three prospective studies have been undertaken comparing the short and medium term outcomes of fixed and mobile UKRs.

A 5 year comparative cohort study of 47 Oxford mobile bearing and 57 St Georg Sled fixed bearing UKRs.

In all groups the preoperative sex mix, average age and knee scores were extremely similar.

All patients were assessed both pre and postoperatively by a research nurse and radiographs were taken; the results were entered on the Bristol Knee database.

Results:

Multiple problems were encountered, perhaps because of the introduction of MIS, but at 5 years 11 Oxford and 4 Sleds had failed. The major problem with the mobile bearing implant was instability though tibial fractures were also seen. Both groups had three cases of arthritic progression and loose cement was seen twice in the fixed bearing group.

– Amongst the remaining patients the median scores for the Sled were better. Bristol Knee Score (Max 100) 95:90; Oxford (Max 48) 39:37; and reduced WOMAC (Best score 12) 18:24.

Conclusion. Although theoretically mobile bearings will give greater longevity there is frequently a short term price to pay particularly when the procedures are performed by inexperienced surgeons and trainees. Since the wear properties of polyethylene have improved in recent years these studies suggest that a fixed bearing option can be used more safely in many patients.

Introduction: The Bristol Knee group has performed over 600 patellofemoral arthroplasties in the last 18 years. Experience with the Lubinus prosthesis led to the development of the Avon Prosthesis. In the last 11 years we have prospectively recorded the results of over 470 consecutive Avon arthroplasties. The main cause of the 9.5% failure is arthritic disease progression in the tibiofemoral compartments.

Patients and Method: Over the last 11 years we have identified 21 patients from our own series and from tertiary referrals that have persistent pain, which was mainly due to technical error rather than arthritic disease progression. The causes can be classified into three main reasons: First, an incorrect anterior cut in the saggital plane which was cut in either too much flexion or extension. Second, the anterior cut had inadequate external rotation, which should be 3–6 degrees to lateralise the groove and facilitate correct tracking. Third, the prosthesis was oversized in several cases leading to retinacular impingement.

Results: The overall results followed up to 10 years showed excellent and consistent improvement in both pain and function as judged by the WOMAC 12 scale. Of those patients with persistent pain, seven had the femoral component revised to either resize the prosthesis or revise the alignment of the anterior resection and correctly inset the prosthesis, with good results. Ten cases were revised to a total knee replacement. In the remaining cases, two had an Insall realignment, one a patella distalisation, and in one no treatment was required. As a permanent solution new instruments were designed to reduce the incision size and increase the accuracy of the saggial alignment and to create an exact amount of external rotation.

Conclusion: The lessons from 11 years experience with the Avon arthroplasty has led to the development of improved instrumentation which should reduce the failures.

Objectives: This study aims to assess the psychological profile of patients prior to total knee replacement, medial unicompartmental knee replacement and patellofemoral joint replacement and determine its effect on outcome.

Methods: 113 patients were identified (41 TKR, 37 UKR and 35 PFJR). All patients had mental health assessed preoperatively using SF-12. From the 12 questions a mental and a physical summary score can be calculated (MCS and PCS). The reduced WOMAC score was used pre-operatively to assess knee function and symptoms and then recorded at 8 and 24 months post-operation to assess outcome.

Results: 54% of the patients had pre-operative psychological distress. There was no statistically significant difference demonstrated between them mean MCS scores between the three operation groups. Pre-operative MCS had a significant effect such that increasing psychological distress lead to a worse twenty-four month outcome (p = 0.016). The effect of MCS is most marked in postoperative pain levels (p = 0.008) compared to function (p = 0.016). The mean 24-month rWOMAC in the severely distressed group (MCS< 40) was 28.4 compared to 17.4 in the psychologically well group (MCS> 60).

Conclusions: Pre-operative mental function prior to knee arthroplasty may provide useful information to guide patients as to their expected outcome in the consent process. Those patients with a very high mental component may be counseled to that although their distress is likely to improve with surgery, their eventual outcome may be worse. The effect of MCS may however only be clinically relevant in those patients with severe mental symptoms.

This observational study was undertaken to explore the relationship of the foot posture of patients with Medial Compartment Osteoarthritis of the knee (MCOA), patients with hip osteoarthritis (OA) and a healthy control group, using the Foot Posture Index (FPI). Goniometric measurement of talocrural dorsiflexion was also included.

The relationship of foot posture to MCOA and hip osteoarthritis OA has not been explored although in other medical fields, such as neurology and sports medicine, the relationship between foot posture, lower limb pain and function has been acknowledged. In view of the current high incidence of lower limb OA, any investigation of associations that may lead to improved assessment and conservative management is worthy of consideration.

Currently, systematic examination of the foot is not undertaken in routine clinical assessment of patients with lower limb OA and, if this were to be introduced, there would be difficulty in selecting suitable clinical outcome measures. The recent development of the Foot Posture Index (FPI) has addressed the need for a diagnostic clinical tool that measures foot posture in multiple planes and anatomical segments

Sixty participants took part: twenty patients with radiographic and clinical evidence of MCOA grade IV, twenty patients with radiographic and clinical evidence of stage IV OA hip, and twenty age-matched healthy volunteers as a control group.

A one way Analysis of variance (ANOVA) was performed to investigate any differences between the 3 groups for foot posture using FPI scores and talocrural dorsiflexion measurements. This showed that there were significant differences between the groups (p< 0.001). Patients with MCOA had a high positive FPI score (indicating a pronated foot), patients with hip OA had a low negative FPI score (indicating a supinated foot). The healthy controls had a normal score distributed over a wider range than the other two groups. In addition, the results of the Pearsons test indicate that the FPI correlated positively with talocrural dorsiflexion (r = 0.55, p< .001).

Differences in foot characteristics may be influenced by specific treatment modalities such as gait reducation, orthotic provision, specific lower limb strengthening and stretching exercises. Foot assessment might therefore be a useful adjunct to conservative management of both MCOA and hip osteoarthritis.

Purpose of Study: Fixed bearing unicompartmental knee replacement (UKR) has become popular since several series have now shown good 10 year survivorship and excellent function. However little is known about survival during the second decade.

Method: From the Bristol database of over 4000 knee replacements 203 St. Georg Sled UKR’s which had already survived 10 years were identified. The mean age at surgery was 67 years (48–85), with 64% being female. This cohort has been further reviewed at an average of 14.8 years (10–30) from surgery to determine survivorship and function.

Results: Survivorship during the second decade was 87.5%. 58 patients (69 knees) had died with implant in situ and only 2 after revision. A further 15 UKR’s have been revised at an average of 13 years post op; 7 for progression of disease in the opposite compartment, 4 for tibial loosening, 3 for polyethylene wear, 2 for femoral component fracture and 2 for infection.

99 knees were followed for 15 years, 21 knees for 20 years and four for 25 or more years. The average Bristol knee score of the surviving knees fell from 86 to 79 during the second decade, largely as a result of aging.

A previous study of the St Georg. Fixed bearing UKR showed an 89% 10 year survivorship and this is now extended to 82% at 15 years and 76.5% at 20 years.

Conclusion: Satisfactory survival of fixed bearing UKR can be achieved in the second decade suggesting that the indications for mobile bearings require careful definition since there is a higher incidence of complications in many people’s hands.

Introduction: There is an impression among Orthopaedic surgeons that mobile bearing knee replacement has a better functional outcome than fixed bearing knee replacement. Since kneeling demands a high level of function after knee replacement this study was undertaken to see if mobile bearings in either total or unicompartmental replacement conferred an advantage.

Methods: A prospective randomised study of 207 TKR patients receiving the same prosthesis (Rotaglid, Corin, UK) was performed. Patients were randomised into a mobile bearing group (102 patients with a mean age of 53 years) and a fixed bearing group (105 patients with a mean age of 55 years). Data was also prospectively collected on 215 UKR patients who received the same unicompartmental implant (AMC, Uniglide, Corin, UK). 136 patients (Mean age: 62 yrs) had a mobile insert and 79 (mean age: 65 yrs) a fixed insert.

All patients completed the Oxford Knee Questionnaire preoperatively as well as at 1 and 2 years postoperatively. Their stated kneeling ability and total scores were analysed with a perfect score for kneeling ability being 4, and 48 the maximum total score.

Results: In all groups both the kneeling ability and the total scores improved markedly from their preoperative state. At two years the total score for the fixed bearing devices was marginally better than for the mobile (Rotaglide 36;31 and Uniglide 37;33)

There was a more striking difference with respect to kneeling ability with the fixed bearing variants performing better, (Rotaglide 1.4; 0.9 and Uniglide 1.9; 1.4), However, the greatest difference was between the UKR and TKR groups (UKR 1.7; TKR 1.2). Pre-operatively less than 2% of TKR patients (7% of the UKR patients) could kneel. Post-operatively, the patients’ kneeling ability improved with 21% for the mobile bearing, 32% of fixed bearing UKR patients. The TKR patients kneeling ability was 13% of the mobile, 26% of fixed bearing patients were able to kneel with little or no difficulty. In all groups the stated kneeling ability was poor with less than 50% of any group being able to kneel with ease or only minor difficulty.

Conclusion: Those undergoing UKR appeared to perform better than those with a TKR. None of the forms of knee replacement used resulted in good kneeling ability, though this function was improved by arthroplasty in all groups. Mobile bearing inserts

Since 1996 over 400 isolated patellofemoral replacements using the Avon prosthesis have been undertaken in Bristol. As a result of the usually gratifying outcomes seen in patients over 55 years old, the indications for this surgery were soon extended to include the many younger patients who have severely disabling patellofemoral disease. We present results from a prospective cohort study of patients under 55 years of age at the time of surgery.

110 knees in 86 patients (median age 47 years, range 24–54) have been treated with Avon patellofemoral replacement (88 in females and 22 in males). Diagnoses included lateral facet OA (59 knees), patella dislocation (25 knees), trochlear dysplasia (41 knees) and post patellectomy instability (7 knees). 79 knees had undergone previous surgery. 17 knees required additional intra-operative procedures including 11 lateral releases and 2 patella realignments. All patients were assessed pre-operatively and at regular intervals using the Oxford, Bristol and WOMAC scores.

All knees were scored preoperative and only one knee has been lost to follow-up due to the patient’s death, which was unrelated to surgery. Post-operative Oxford knee scores have been obtained for 106 knees with follow-up between 8 months and 8 years (mean follow-up 24 months). The mean Oxford score improved from 18 preoperatively to 31 at latest review. Bristol and WOMAC scores showed similar improvements. 16 knees required post-operative additional procedures including 6 lateral releases, 3 patella realignments and 11 revisions. Of the revisions 5 were for progression of tibiofemoral OA but none of these were knees with trochlear dysplasia. Equally good mean scores were seen when comparing patients with the 3 main underlying pathologies (trochlear dysplasia, patellar dislocation and lateral facet OA). At least 37% of the patients studied had pre-existing trochlear dysplasia and the majority of these patients report onset of symptoms, often patellar dislocation, in the first three decades of life. More than 90% of patients were overweight or obese according to their BMI at the time of surgery.

Many of this type of patient, with disabling symptoms, wish to “live now”. The short-term improvements are frequently dramatic. As yet there is no suggestion of prosthetic failure. Revision presents little difficulty since minimal bone is resected in the primary proceedure. Radiological deterioration of the tibio femoral joint is seen in some cases of primary OA but not with trochlear dysplasia.

Between 1989 and 1992 we had 102 knees suitable for unicompartmental knee replacement (UKR). They were randomised to receive either a St Georg Sled UKR or a Kinematic modular total knee replacement (TKR). The early results demonstrated that the UKR group had less complications and more rapid rehabilitation than the TKR group. At five years there were an equal number of failures in the two groups but the UKR group had more excellent results and a greater range of movement.

The cases were reviewed by a research nurse at 8, 10 and 12 years after operation. We report the outcome at 15 years follow-up. A total of 43 patients (45 knees) died with their prosthetic knees intact. Throughout the review period the Bristol knee scores of the UKR group have been better and at 15 years 15 (71.4%) of the surviving UKRs and 10 (52.6%) of the surviving TKRs had achieved an excellent score. The 15 years survivorship rate based on revision or failure for any reason was 24 (89.8%) for UKR and 19 (78.7%) for TKR. During the 15 years of the review four UKRs and six TKRs failed.

The better early results with UKR are maintained at 15 years with no greater failure rate. The median Bristol knee score of the UKR group was 91.1 at five years and 92 at 15 years, suggesting little functional deterioration in either the prosthesis or the remainder of the joint. These results justify the increased use of UKR.

Purpose: Revision patellofemoral arthroplasty (PFA) is a relatively uncommon procedure, with no published reviews identified in the literature. Revision PFAs performed at our institution were reviewed to determine the reasons for PFA failure, the technical ease of revision and to document patient-reported outcomes after revision.

Methods: A prospective review of a cohort of 411 Avon PFA patients identified 31 subsequent revision knee procedures in 27 patients. Data was collected from the institution’s prospective data base, operative reports, X-rays and medical records. Post-operative knee scores (Oxford Knee Score, WOMAC Osteoarthritis Index, Bristol Knee Score) were available on 26 knees.

Results: The commonest reason for revision was progression of osteoarthritis (18 cases) followed by undetermined pain (7 cases). Patients with undetermined pain were found to be revised sooner than patients with disease progression (33 months vs 63 months) and also reported poorer outcome scores at 2 years post revision than the disease progression group.

Only two trochlea components were loose at the time of revision and one patella had a large amount of macroscopic wear. All other components were found to be well fixed with minimal wear at the time of revision. There were no difficulties in removing either component. No cases required augments or stemmed femoral components due to bone loss.

Patients undergoing revision surgery did report improvement in their post revision outcome scores compared with their pre-operative scores. The average Oxford Knee Score improved from 17 to 23, Bristol Knee Pain Scores improved from 11 to 20 and Bristol Knee Functional Scores improved from 15 to 16. These results are poorer than those recorded by the overall cohort of primary PFA.

Conclusion: PFA is easy to revise to a primary total knee. Results of revision knees are improved from pre-operative scores but not as good as expected.

Introduction: Metal-on-metal hip resurfacing arthroplasty (HRA) is currently recommended for younger, active patients with high expectations but information about outcomes is limited. Reports concentrate on wear, fracture rates and radiographic appearance, rather than function. Studies that report function do not describe rehabilitation protocols. This data is important to discussions about likely outcomes and restrictions prior to consent and to fully evaluate HRA.

Methods: Consecutive Conserve HRA operations were reviewed 1 year post-surgery. Function was assessed using 3 validated questionnaires; the OHS (Oxford Hip Score), HOOS (Hip Disability and Osteoarthritis Outcome Score) and UCLA Activity Scale. Complications, pain, ROM, muscle strength, single leg stand, walking and stair climbing ability were recorded.

Results: 125 HRA were reviewed (68 right, 57 left hips) in 120 patients (71 male, 49 female) of mean age 56 years. 86.7% recorded no complications, but 20% had pain at 3 months. The median OHS was 15, median UCLA 7 (active) and mean HOOS 82.78%. Operated hip flexors, extensors and abductors were weaker (p=0.000) and hip flexion ROM a mean 94.46 ± 12.71 (55–120) degrees. For 25% walking was limited, 7.6% needed a stick and 10% a stair rail. The OHS correlated with HOOS pain subscale (r=0.812, p=0.000), flexion ROM (r=0.426, p=0.000), hip extensor (r=0.359, p=0.000) and abductor (r=0.424, p=0.000) strength. Pain at 3 months correlated with the HOOS pain subscale (p=0.000, r= 0.503).

Discussion: Although outcomes were generally good with few complications, high levels of function and activity 25% had poor outcomes; with pain, restricted hip flexion, decreased strength, limited walking and functional problems, particularly putting on socks. Pain present at 3 months was associated with pain and worse function at 1 year. It is postulated this sub-optimal recovery may be related to current rehabilitation protocols adopted from THA and not tailored to HRA.

Background: In the UK 80% unicompartmental knee replacements(UKRs) and 10% of total knee replacements(TKRs) use mobile bearings. It is suggested that mobile bearings are more physiological and wear less, however it is still unclear whether patients tolerate mobile bearing knee replacements as well.

Patients and methods: We report four prospective studies,. Two compared fixed with mobile bearings in TKR and two in UKR. The prostheses involved were fixed and mobile variants of the Rotaglide (TKR), Kinemax (TKR) and Uniglide (UKR). In addition the Oxford and St. George Sled UKRs were compared. All except the Uniglide study were randomized prospective trials (RCTs)

611 patients were involved with a mean age of 68 years. Residual pain following surgery was assessed with either the Oxford Knee Score (OKS) or the WOMAC score. The patients were followed up at one and two years postoperatively by a Research nurse and the findings recorded prospectively on the Bristol Knee database.

Results:

Conclusion: Our data suggests that the fixed bearing knee replacements result in less residual pain than their mobile bearing counterparts, at least in the first two years following surgery.