Hip resurfacing procedures have gained increasing popularity for younger, higher demand patients with degenerative hip pathologies. However, with concerns regarding revision rates and possible adverse metal hypersensitivity reactions with metal-on-metal articulations, some authors have questioned the hypothesised superiority of hip resurfacing over total hip arthroplasty. The purpose of this meta-analysis was to compare the clinical and radiological outcomes and complication rates of these two procedures.

A systematic review was undertaken of all published and unpublished research up to January 2010. The primary search was of the databases Medline, CINAHL, AMED and EMBASE, searched via Ovid using MeSH terms and Boolian operators ‘hip’ AND ‘replacement’ OR ‘arthroplasty’ AND ‘resurfacing’. A secondary search of unpublished literature was conducted using the databases SIGLE, the National Technical Information Service, the National Research Register (UK), the British Library's Integrated Catalogue and Current Controlled Trials databases using the same search terms as the primary search. All included studies were critically appraised with the CASP appraisal tool.

In total, 46 studies were identified from 1124 citations. These included 3799 hip resurfacings and 3282 total hip arthroplasties. On meta-analysis, functional outcomes for subjects following hip resurfacing were better than or the same as subjects with a total hip arthroplasty, with significantly higher WOMAC score (Mean Difference (MD)=−2.41; 95% Confidence Interval (CI): −3.88, −0.94; p=0.001), and significantly better Harris Hip Score (range of motion component) (MD=−0.05; 95% CI: (−0.07, −0.03; p<0.0001) and overall Harris Hip Score (MD=2.51; 95% CI: 1.24, 3.77; p=0.0001) in the hip resurfacing compared to total hip arthroplasty cohorts. However, there were significantly greater incidences of heterotopic ossification (Risk Ratio (RR)=1.62; 95% CI: 1.23, 2.14; p=0.006), aseptic loosening (RR=3.07; 95% CI:1.11, 8.50;p=0.03) and revision surgery (RR=1.72; 95% CI: 1.20, 2.45; p=0.003) with hip resurfacing compared to total hip arthroplasty. The evidence-base presented with a number of methodological inadequacies such as the limited use of power calculations and poor or absent blinding of both patients and assessors, potentially giving rise to assessor bias. In respect to these factors, the current evidence-base, whilst substantial in its size, may be questioned in respect to its quality in determining superiority of hip resurfacing over total hip arthroplasty.

Purpose of Study

To investigate the proprioceptive function of patients with an ACL rupture before and after reconstruction and correlate these findings with ligament laxity testing and clinical outcome measures.

Aim: To determine the accuracy of clinical diagnosis in patients undergoing arthroscopic surgery of the knee.

Methods: A retrospective analysis of patients who had undergone knee arthroscopy at the Norfolk and Norwich University Hospital was performed from a prospectively gathered database. Pre-operative diagnosis was compared with operative diagnosis to determine the accuracy, sensitivity and specificity of the clinical diagnosis. The data was then analysed to determine how many patients underwent a beneficial procedure, which was defined as “a procedure from which the patient is likely to have benefited, either as a result of confirming the diagnosis or therapeutic intervention”. Finally, the results were compared with those from studies where the accuracy of MRI was assessed, to determine whether MRI is a more accurate diagnostic modality than clinical examination.

Results: The data of 698 patients was analysed. Of these 64% were male and 36% were female. The mean age at operation was 41 years (9 to 92). The overall accuracy, sensitivity and specificity of clinical diagnosis was 99%, 70% and 99% respectively. 90% of patients underwent a beneficial procedure, while 10% had a normal knee diagnosed at operation. Medial meniscal tear was the hardest pathology to diagnose, with accuracy, sensitivity and specificity rates of 82%, 92% and 79%. The results fell within the range of those found in studies, which examined the accuracy, sensitivity and specificity of MRI.

Conclusion: Our results show that clinical examination remains an accurate method of diagnosing intra-articular pathologies of the knee. Medial meniscal tear appears to be the hardest pathology to diagnose, and was the only condition with an accuracy rate under the 90th percentile. This is probably because medial tibio-femoral articular dysfunction has similar clinical findings. MRI was found to be no more effective than clinical examination at diagnosing pathologies of the knee.

60 out of total series of 643 metal-on-metal hip replacements, carried out over the last nine years, have so far required revision, 13 for peri-prosthetic fracture and 47 for extensive, symptomatic, peri-articular soft-tissue changes.

Dramatic corrosion of generally solidly fixed, cemented stems has been observed and is believed to have resulted in the release of high levels of cobalt chrome ions from the stem surface. The contribution of the metal-to-metal articulation is, as yet, unclear.

Not including the fracture cases, plain films have demonstrated little or no abnormality to account for patients’ progressive symptoms. MRI scanning, on the other hand, utilising a technique designed to minimise implant artefact, has correlated very closely with findings at the time of revision surgery.

The histological changes, typified by extensive lymphocytic infiltration and a severe vasculitis leading to, in some cases, extensive tissue necrosis are demonstrated and discussed.

The failure of any of the existing protective mechanisms or regulatory restrictions to identify and limit the exposure of large numbers of patients to unsatisfactory implants has again been demonstrated.

Imaging techniques including MR scanning and ultrasound were discussed. However it was noted that for standard orthopaedic practice in the UK plain films were the initial imaging available. The importance of taking a skyline view was stressed.

The Dejour protocol was then outlined where the lateral Xray of the knee assesses the patellar height, the presence of dysplasia of the trochlear groove, and, if present, its boss height. A CT scan defines the patellar tilt angle, and with cuts through the tibial tubercle, the offset of the tibial tubercle from the trochlear groove (TTTG). The four abnormalities that can be defined are then corrected at operation. All patients undergo a lateral release. If the patellar tilt angle is greater than 20° then a medial reefing is performed. If the patellar height is greater than 1.2, a distalisation of the tibial tubercle to correct this to 1.0 is done. A MG of greater than 2Omm leads to a correction by an Elmsie medial tubercle transfer. A boss height of greater than 6mm suggests a trochleoplasty should be performed. However the Dejour protocol is yet to be validated.

It was concluded that imaging is essential for analysing patellofemoral instability. Plain films alone do not give enough information. Patterns of patellofemoral instability as assessed by CT scan (and MRI scan) are yet to be established. Postoperative imaging to confirm correction of abnormalities should be done. The measurements are worthwhile but their validation is awaited.

The positioning of components in knee replacement is related to outcome and for this reason a study has been conducted to compare the exact position of the tibial and femoral components in total knee arthroplasty with the placement as judged by the surgeon at the time of operation.

Operating surgeons of a range of grades completed a pro-forma immediately after operating on 25 patients having total knee replacement. Patients were entered into the study by consent providing that they had osteoarthritis and this was their first ever lower limb joint replacement. The form detailed where the surgeon considered he had placed the femoral component in the coronal plane and in terms of rotation upon the femur. They were asked to state what lines or angles of reference they had used and whether they had used intra or extra medullary jigs. Likewise for the tibia, implant position was detailed for coronal, sagittal and transverse planes. The proforma stated the grade of operating surgeon but were otherwise kept anonymous.

All study patients had pre and postoperative CT scans. These involved an AP scannogram and transverse sections, according to a protocol, through the femoral neck, femoral condyles, tibial plateau and ankle. By comparing bony landmarks seen on the pre-operative CT scans with lines of reference from the components post-operatively the exact position of the implant was determined in the transverse and coronal planes. For the sagittal plane (slope) the standard lateral X-ray was used.

For the femur all operations were carried out using intra-medullary jigs. For the femoral component the difference was not significant between the measured position and the surgeons estimate in any plane (p=0.937 for coronal and p=0.432 for transverse). The measured position of the component was not related to the grade of the operating surgeon nor to the axis nor technique of reference used.

For the tibial component, coronal alignment was significantly different (p=0.001) with the measured position being in more varus than was estimated. The range of transverse placement was from 4° of external rotation to 35° of internal rotation of the tibial prosthesis with reference to the tibial tubercle centre. This was significantly different to that estimated by the surgeon (p< 0.001). Estimation of slope in the sagittal plane was good. None of these differences were related to operator grade. For 15 of the TKR’s the tibail component was aligned using intra-medullary techniques. This was related to the accuracy of positioning of the prosthesis with significantly better estimation compared to those in which extra-medulary jigs had been used (p=0.002 for the transverse plane and p=0.065 for the coronal plane).

This study has demonstarted that surgeons are able to accurately judge the position of insertion of the femoral component in total knee replacement. Surgeons are poor at estimating the position of the tibial component in the transverse and coronal planes but better in the sagittal plane. Due to the difficulty in its assessment rotational alignment has been ignored in arthroplasty but as with alignment in the other planes it is likely to have a bearing on outcome. Improved techniques to help us judge placement of knee components are needed.