When the Oxford unicompartmental meniscal bearing arthroplasty is used in the lateral compartment of the knee, 10% of the bearings dislocate. A radiological review was carried out to establish if dislocation was related to surgical technique. The postoperative radiographs of 46 lateral unicompartmental arthroplasties were analysed. Five variables which related to the position and alignment of the components were measured. Dislocations occurred in six knees. Only one of the five variables, the proximal tibial varus angle, had a statistically significant relationship to dislocation. This variable quantifies the height of the lateral joint line. The mean proximal tibial varus angle for knees the bearings of which had dislocated was 9° and for those which had not it was 5°. In both groups it was greater than would be expected in the normal knee (3°). Our study suggests that a high proximal tibial varus angle is associated with dislocation. The surgical technique should be modified to account for this, with care being taken to avoid damage to or over-distraction of the lateral soft tissues

If conclusions are to be of any value they must be definite and one cannot draw definite conclusions from less than, say, fifty cases followed up for at least five years. However, few surgeons will ever see fifty patients requiring arthroplasty of the knee, let alone operate of them, even in five years. Accordingly, this account of a new approach to the problem of knee arthroplasty is submitted in the hope that other surgeons may care to try it and thereby learn, and thus be able to teach, tile modifications and improvements that all new techniques seem so surely to need

Thirty patients with chronic pyogenic or tuberculous arthritis of the hip treated by Girdlestone's excision arthroplasty were reviewed two to seven years after operation. There was marked or complete relief of pain in 29, control of infection in 27, squatting and sitting cross-legged was possible in 27, and 16 were able to stand on the operated limb. Overall results were good in 16, fair in nine, and poor in five. Tuberculous disease was not reactivated and the use of traction for 12 weeks and a weight-relieving caliper for 12 months after operation helped to reduce the shortening to an average of 3.8 centimetres. Excision arthroplasty is considered a sound operation to restore the ability to squat and sit cross-legged

We prepared a prosthesis for the replacement of the lumbar vertebrae of sheep, using apatite- and wollastonite-containing glass-ceramic. The material is stronger than human cortical bone and has the special feature of chemical bonding to bone. Ten sheep underwent replacement of L3 and L4 vertebrae, without bone grafting. The animals were killed at intervals from three months to 27 months after operation, and the interface between the prosthesis and bone was examined radiologically, histologically and crystallographically. Bone bonding with the prosthesis had occurred in half the implants. It took at least one year for bonding to be complete, but an apatite layer on the surface of the prosthesis was observed as early as three months after the operation, suggesting the possibility of much earlier bone bonding if more rigid fixation of the prosthesis had been provided

We investigated whether improvements in design have altered the outcome for patients undergoing endoprosthetic replacement of the distal femur after resection of a tumour. Survival of the implant and ‘servicing’ procedures have been documented using a prospective database, review of the design of the implant and case records. In total, 335 patients underwent a distal femoral replacement, 162 having a fixed-hinge design and 173 a rotating-hinge. The median age of the patients was 24 years (interquartile range 17 to 48). A total of 192 patients remained alive with a mean follow-up of 12 years (5 to 30). The risk of revision for any reason was 17% at five years, 33% at ten years and 58% at 20 years. Aseptic loosening was the main reason for revision of the fixed-hinge knees while infection and fracture of the stem were the most common for the rotating-hinge implant. The risk of revision for aseptic loosening was 35% at ten years with the fixed-hinge knee, which has, however, been replaced by the rotating-hinge knee with a hydroxyapatite collar. The overall risk of revision for any reason fell by 52% when the rotating-hinge implant was used. Improvements in the design of distal femoral endoprostheses have significantly decreased the need for revision operations, but infection remains a serious problem. We believe that a cemented, rotating-hinge prosthesis with a hydroxyapatite collar offers the best chance of long-term survival of the prosthesis

Thirty-three Girdlestone's arthroplasties used to salvage infected total hip replacements were followed for a mean of 6.2 years to assess the efficacy of this procedure. Subjective and objective assessment was obtained at the time of review. Gram-negative organisms, retained cement, bony sequestra and secondary healing were common features of the five patients (15%) whose wounds discharged for more than four weeks after operation. Girdlestone's arthroplasty provided satisfactory pain relief in 91% of patients, and control of infection in 97%. Although leg-length discrepancy (mean 4 cm) and a Trendelenburg gait made walking difficult and tiring , 42% were satisfied with their functional ability; 85% needed walking aids, and 3 patients could not walk at all and were confined to bed or a chair. Overall, 79% were satisfied. Objectively, the mean Harris hip rating was 60; however, if patients with multiple joint problems were excluded, this score increased to 77. Girdlestone's arthroplasty seems a reasonable salvage procedure in the management of an infected total hip replacement and the results seem to improve with time

Resurfacing arthroplasty of the hip is being performed more frequently in the United Kingdom. The majority of these patients are younger than 55 years of age, and in this group the key benefits include conservation of femoral bone stock and the potential reduction in the rate of dislocation afforded by the larger resurfacing head. Early aseptic loosening is well recognised in patients younger than 55 years of age, and proponents of resurfacing believe that the improved wear characteristics of the metal-on-metal bearing may improve the long-term survival of this implant. There has been some concern, however, that resurfacing may not be conservative of acetabular bone. We compared a series of 33 consecutive patients who had a hybrid total hip arthroplasty with an uncemented acetabular component and a cemented femoral implant, with 35 patients undergoing a Birmingham hip resurfacing arthroplasty. We compared the diameter of the implanted acetabulum in both groups and, because they were not directly comparable, we corrected for patient size by measuring the diameter of the contralateral femoral head. The data were analysed using unpaired t-tests and analysis of covariance. There was a significantly larger acetabulum in the Birmingham arthroplasty group (mean diameter 56.6 mm vs 52.0 mm; p < 0.001). However, this group had a significantly larger femoral head diameter on the contralateral side (p = 0.03). Analysis of covariance revealed a significant difference between the mean size of the acetabular component implanted in the two operations. The greatest difference in the size of acetabulum was in those patients with a larger diameter of the femoral head. This study shows that more bone is removed from the acetabulum in hip resurfacing than during hybrid total hip arthroplasty, a difference which is most marked in larger patients

Arthroplasty, with normal or nearly normal reposition, is possible in most old congenital dislocations of the hip in young adults. Reposition is possible even in very high dislocation, but it is difficult or impossible in aged patients and when arthritic changes have taken place. The reduction equalises the length of the extremities in unilateral cases, but makes operation on both sides necessary in bilateral cases. Post-operative complications may be largely avoided by a good technique and careful post-operative treatment. Stability is good, and consequently the limp is generally reduced. Mobility is as a rule sufficient, though often less than before operation when the hip was normally or excessively mobile. Pain is very often relieved or greatly reduced, but walking is generally limited. Even if the radiographic appearance of the hip is almost normal, the functional result may be imperfect. This assessment is probably pessimistic, for two reasons: first, patients operated on are still improving; second, the improved technique of the later operations should give better results. Nevertheless, arthroplasty with reduction should be proposed to patients only suffering severe functional disability

The aim of this study was to determine if a change in antibiotic prophylaxis for routine hip and knee replacement was associated with an increased risk of acute renal impairment. . We identified 238 patients (128 knees and 110 hips) who had received a single prophylactic dose of 1.5 g cefuroxime before joint replacement. We compared them with prospectively collected data from 254 patients (117 knees and 137 hips) who received a single prophylactic dose of 2 g flucloxacillin and a height- and gender-determined dose of gentamicin. The primary outcome measure was any new renal impairment as graded by clinically validated criteria. We identified four patients (1.69%) in the cefuroxime group who developed renal impairment. All four had mild impairment and all renal function was normal by the third post-operative day. The incidence of new-onset renal impairment was significantly higher in the flucloxacillin-and-gentamicin group at 9.45% (24 patients) (p < 0.001). Three of these patients remained with acute renal impairment after a week, although the serum creatinine levels in all subsequently returned to normal. Cite this article: Bone Joint J 2014;96-B:395–8

Aims

The aim of this study was to report the results of custom-made endoprostheses with extracortical plates plus or minus a short, intramedullary stem aimed at preserving the physis after resection of bone sarcomas in children.

Arthroplasty registries are important for the surveillance of joint replacements and the evaluation of outcome. Independent validation of registry data ensures high quality. The ability for orthopaedic implant retrieval centres to validate registry data is not known. We analysed data from the National Joint Registry for England, Wales and Northern Ireland (NJR) for primary metal-on-metal hip arthroplasties performed between 2003 and 2013. Records were linked to the London Implant Retrieval Centre (RC) for validation. A total of 67 045 procedures on the NJR and 782 revised pairs of components from the RC were included. We were able to link 476 procedures (60.9%) recorded with the RC to the NJR successfully. However, 306 procedures (39.1%) could not be linked. The outcome recorded by the NJR (as either revised, unrevised or death) for a primary procedure was incorrect in 79 linked cases (16.6%). The rate of registry-retrieval linkage and correct assignment of outcome code improved over time. The rates of error for component reference numbers on the NJR were as follows: femoral head category number 14/229 (5.0%); femoral head batch number 13/232 (5.3%); acetabular component category number 2/293 (0.7%) and acetabular component batch number 24/347 (6.5%). . Registry-retrieval linkage provided a novel means for the validation of data, particularly for component fields. This study suggests that NJR reports may underestimate rates of revision for many types of metal-on-metal hip replacement. This is topical given the increasing scope for NJR data. We recommend a system for continuous independent evaluation of the quality and validity of NJR data. Cite this article: Bone Joint J 2015;97-B:10–18

The Department of Health and the Public Health Laboratory Service established the Nosocomial Infection National Surveillance Scheme in order to standardise the collection of information about infections acquired in hospital in the United Kingdom and provide national data with which hospitals could measure their own performance. The definition of superficial incisional infection (skin and subcutaneous tissue), set by the Center for Disease Control (CDC), should meet at least one of the defined criteria which would confirm the diagnosis and determine the need for specific treatment. We have assessed the interobserver reliability of the criteria for superficial incisional infection set by the CDC in our current practice. The incisional site of 50 patients who had an elective primary arthroplasty of the hip or knee was evaluated independently by two orthopaedic clinical research fellows and two orthopaedic ward sisters for the presence or absence of surgical-site infection. Interobserver reliability was assessed by comparison of the criteria for wound infection used by the four observers using kappa reliability coefficients. Our study demonstrated that some of the components of the current CDC criteria were unreliable and we recommend their revision

The stages in adolescent slipping of the upper femoral epiphysis are classified in relation to treatment. The operation of open replacement of the displaced femoral head is described, and the results of a personal series of seventy-three such operations are presented. Open replacement is excellent treatment for severe chronic slipping so long as the growth plate is still open. The greater incidence of avascular necrosis in acute-on-chronic cases is probably due to damage to the blood supply of the head at the time of the acute slip or kinking of the vessels before replacement. Prolonged traction before operation may increase the risk of chondrolysis. Late onset of osteoarthritis when neither avascular necrosis nor chondrolysis has occurred may be due to misfitting of the articular cartilage because of inaccurate reduction

We report the long-term results of revision total hip replacement using femoral impaction allografting with both uncemented and cemented Freeman femoral components. A standard design of component was used in both groups, with additional proximal hydroxyapatite coating in the uncemented group. A total of 33 hips in 30 patients received an uncemented component and 31 hips in 30 patients a cemented component. The mean follow-up was 9.8 years (2 to 17) in the uncemented group and 6.2 years (1 to 11) in the cemented group. Revision procedures (for all causes) were required in four patients (four hips) in the uncemented group and in five patients (five hips) in the cemented group. Harris hip scores improved significantly in both groups and were maintained independently of the extent of any migration of the femoral component within the graft or graft–cement mantle

Survival analysis is a powerful tool for analysing the results of total joint replacement, but it has major drawbacks when the failure rates are very low. We have reviewed 35 recent survival analyses of joint replacements to assess the magnitude of these problems and make recommendations as to how they may be avoided

Resection arthroplasty of the patella has been found to be a satisfactory procedure for the treatment of patellofemoral pain caused by osteoarthritis. In the present series 60% of the operated cases were pain-free on a 31-month average follow-up. The patients found it easier to climb stairs and to kneel and in most cases the radiographic joint space was good

We evaluated the outcome of 41 consecutive Charnley low-friction arthroplasties (LFAs) performed by a single surgeon in 28 patients aged ≤ 35 years at operation between 23 and 36 years previously. There were 20 women and eight men with a mean age of 32 years (23 to 35) at surgery. Two patients (three hips) were lost to follow-up at 12 and 17 years post-operatively, respectively, and one patient (one hip) died at 13 years post-operatively. These patients were excluded from the final evaluation. The survival rate of the acetabular components was 92.7% (95% confidence interval (CI) 88.7 to 96.7) at ten years, 67.1% (95% CI 59.75 to 74.45) at 20 years and 53.2% (95% CI 45.3 to 61.1) at 25 years. For the femoral component the survival was 95.1% (95% CI 91.8 to 98.5) at ten years, 77.1% (95% CI 73.9 to 80.3) at 20 years and 68.2% (95% CI 60.7 to 75.8) at 25 years. The results indicate that the Charnley LFA remains a reasonable choice in the treatment of young patients and can serve for comparison with newer techniques and implants. Cite this article: Bone Joint J 2013;95-B:1052–6

Narrowing of the femoral neck after resurfacing arthroplasty of the hip has been described previously in both cemented and uncemented hip resurfacing. The natural history of narrowing of the femoral neck is unknown. We retrospectively measured the diameter of the femoral neck in a series of 163 Birmingham hip resurfacings in 163 patients up to a maximum of six years after operation to determine the extent and progression of narrowing. There were 105 men and 58 women with a mean age of 52 years (18 to 82). At a mean follow-up of five years, the mean Harris hip score was 94.8 (47 to 100) and the mean flexion of the hip 112.5° (80° to 160°). There was some narrowing of the femoral neck in 77% (125) of the patients reviewed, and in 27.6% (45) the narrowing exceeded 10% of the diameter of the neck. A multiple logistic regression analysis showed a significant association (chi-squared test (derived from logistic regression) p = 0.01) of narrowing with female gender and a valgus femoral neck/shaft angle. There was no significant association between the range of movement, position or size of the component or radiological lucent lines and narrowing of the neck (chi-squared test; p = 0.10 (flexion), p = 0.08 (size of femoral component), p = 0.09 (size of acetabular component), p = 0.71 (femoral component angulation), p = 0.99 (lucent lines)). There was no significant difference between the diameter of the neck at a mean of three years (2.5 to 3.5) and that at five years (4.5 to 5.5), indicating that any change in the diameter of the neck had stabilised by three years (sign rank test, p = 0.60). We conclude that narrowing of the femoral neck which is found with the Birmingham hip resurfacing arthroplasty is in most cases associated with no adverse clinical or radiological outcome up to a maximum of six years after the initial operation

Aims. Glenoid bone loss can be a challenging problem when revising a shoulder arthroplasty. Precise pre-operative planning based on plain radiographs or CT scans is essential. We have investigated a new radiological classification system to describe the degree of medialisation of the bony glenoid and that will indicate the amount of bone potentially available for supporting a glenoid component. It depends on the relationship between the most medial part of the articular surface of the glenoid with the base of the coracoid process and the spinoglenoid notch: it classifies the degree of bone loss into three types. It also attempts to predict the type of glenoid reconstruction that may be possible (impaction bone grafting, structural grafting or simple non-augmented arthroplasty) and gives guidance about whether a pre-operative CT scan is indicated. Patients and Methods. Inter-method reliability between plain radiographs and CT scans was assessed retrospectively by three independent observers using data from 39 randomly selected patients. . Inter-observer reliability and test-retest reliability was tested on the same cohort using Cohen's kappa statistics. Correlation of the type of glenoid with the Constant score and its pain component was analysed using the Kruskal-Wallis method on data from 128 patients. Anatomical studies of the scapula were reviewed to explain the findings. Results. Excellent inter-method reliability, inter-observer and test-retest reliability were seen. The system did not correlate with the Constant score, but correlated well with its pain component. . Take home message: Our system of classification is a helpful guide to the degree of glenoid bone loss when embarking on revision shoulder arthroplasty. Cite this article: Bone Joint J 2016;98-B:374–80

A retrospective review of medial compartment arthroplasty in 22 patients (22 knees) is reported. The operations were performed between 1973 and 1978. Eighty-six per cent were rated good or excellent using the knee rating system devised by the Hospital for Special Surgery, New York. Excellent or good results were achieved in six patients who had previously had a high tibial osteotomy. At the time of follow-up significant loosening had not occurred, although progression of patellofemoral disease was noted. This study supports the promising results reported for unicompartmental resurfacing arthroplasty in the elderly