Outcome of Charnley total hip replacement across a single health region in England

Total Hip Replacement in Patients with Rheumatoid Arthritis: Trends in Incidence and Complication Rates Over 35 Years

INTRODUCTION

Advances in rheumatoid arthritis (RA) management have made disease remission achievable. We evaluated trends in total hip replacement (THR) and postoperative outcomes in patients with RA in Western Australia (WA) over more than three decades.

METHODS

This was a retrospective analysis of routinely collected prospective data from a state-wide registry containing longitudinally linked administrative health data based on International Classification of Diseases (ICD) diagnostic and procedural codes. We included patients with two or more diagnostic codes for RA (between 1980 and 2015) and studied THR incidence rates (THR IR) and complication rates (revision, peri-prosthetic fracture, infection, venous thrombosis, and mechanical loosening). Survival rates were estimated by Kaplan-Meier method and predictors analyzed by Cox regression.

RESULTS

We followed 9201 RA patients over 111,625 person-years, during which 1560 patients (16.9%) underwent THR. From 1985 to 2015, THR IR (per 1000 RA patient-years) decreased from 20.8 (95% CI 20.1-21.5) to 7.3 (95% CI 7.2-7.5), and 5-year THR-free survival increased from 84.3 to 95.3% (1980-2015). Ten-year prosthetic survival was 91.2%. Complication rates in the first 5 years post-THR decreased significantly from 13.1 to 3.7% (p < 0.001). Mechanical complications such as loosening and periprosthetic fracture rates decreased significantly (> 35%, P < 0.05), while infection and revision did not change over the observation period (p > 0.05).

CONCLUSIONS

Over the last 30 years in RA patients, THR IR and mechanical complication rates decreased significantly, but the medical complication of infection has not changed significantly.

Adverse reaction to metal debris due to fretting corrosion between the acetabular components of modular dual-mobility constructs in total hip replacement: a systematic review and meta-analysis

Modular dual-mobility (MDM) constructs can be used to reduce dislocation rates after total hip replacement (THR). However, there are concerns about adverse reaction to metal debris (ARMD) as a result of fretting corrosion between the metal liner and shell. This systematic review reports outcomes following THR using MDM components. It was registered with PROSPERO and conducted in line with Cochrane and PRISMA recommendations.Sixteen articles were included overall, with meta-analysis performed on relevant subsets using a random intercept logistic regression model. Estimated median incidence of ARMD requiring revision surgery within study follow-up period was 0.3% (95% CI 0.1 - 1.8%, from 11 cohort studies containing 1312 cases).Serum metal ion levels were mildly raised in 7.9% of cases, and significantly raised in 1.8%, but there was no correlation with worse clinical hip function scores within studies. Dislocation rate was 0.8%. Revision rate was 3.3%.There are mixed reports of wear on the backside of the metal liner from the acetabular shell and screw heads. Both implant design and component malseating are implicated, but currently it is unclear to what extent each factor is responsible.Studies were poor quality with high risk of confounding, especially from trunnion corrosion. We have made recommendations for further work. In the meantime, surgeons should be aware of the potential risk of ARMD when considering using an MDM prosthesis, and, if selecting one, must ensure proper seating of the liner and screws intraoperatively. Cite this article: EFORT Open Rev 2021;6:343-353. DOI: 10.1302/2058-5241.6.200146.

The Prevention of Periprosthetic Joint Infection in Primary Total Hip Arthroplasty Using Pre-Operative Chlorhexidine Bathing

Periprosthetic joint infection (PJI) after total hip arthroplasty (THA) is a devastating complication. The aim of this study was to investigate whether preoperative bathing using chlorhexidine gluconate (CHG) before THA can effectively reduce the postoperative PJI rate. A total of 933 primary THA patients, with the majority being female (54.4%) were included in the study. Primary THA patients who performed preoperative chlorhexidine bathing were assigned to the CHG group (190 subjects), and those who did not have preoperative chlorhexidine bathing were in the control group (743 subjects). The effects of chlorhexidine bathing on the prevention of PJI incidence rates were investigated. Differences in age, sex, and the operated side between the two groups were not statistically significant. Postoperative PJI occurred in four subjects, indicating an infection rate of 0.43% (4/933). All four infected subjects belonged to the control group. Although the PJI cases were significantly more in the control group than in the CHG group, statistical analysis revealed no statistical significance in the risk of PJI occurrence between the two groups (p = 0.588). Preoperative skin preparation by bathing with a 2% chlorhexidine gluconate cleanser did not produce significant effects on the prevention of postoperative PJI in primary THA.

A retained stitch in time saves 9 - but does it increase the risk of deep prosthetic infection?

INTRODUCTION

During the posterior approach to the hip, the short external rotators are detached and secured with stay sutures. At the time of definitive closure, some surgeons incorporate the initial sutures into their repair while others discard for fresh sutures, presumably as an infection prevention measure. We have conducted a pilot study to investigate whether the incorporation of the primary stay sutures may constitute an infection risk to the patient undergoing a total hip replacement through the posterior approach.

MATERIALS AND METHODS

The pilot study was conducted between August 2014 and June 2015. A pair of suture specimens were sent from 25 patients to microbiology, 1 set of primary stay sutures and 1 set of control sutures. All operations were carried out by the senior author through a posterior approach.

RESULTS

All specimens were analysed for bacterial and fungal growth, using extended cultures. 1 set of primary sutures had a positive growth, likely from skin contamination; 1 set of control sutures also had a positive growth, likely from environmental contamination.

CONCLUSIONS

Our pilot study suggests that the practice of incorporating the primary stay sutures for definitive soft tissue repair of the short external rotators, rather than exchanging them for new sutures, can be deemed safe.

Hip resurfacing versus total hip arthroplasty: a systematic review comparing standardized outcomes

BACKGROUND

Metal-on-metal hip resurfacing was developed for younger, active patients as an alternative to THA, but it remains controversial. Study heterogeneity, inconsistent outcome definitions, and unstandardized outcome measures challenge our ability to compare arthroplasty outcomes studies.

QUESTIONS/PURPOSES

We asked how early revisions or reoperations (within 5 years of surgery) and overall revisions, adverse events, and postoperative component malalignment compare among studies of metal-on-metal hip resurfacing with THA among patients with hip osteoarthritis. Secondarily, we compared the revision frequency identified in the systematic review with revisions reported in four major joint replacement registries.

METHODS

We conducted a systematic review of English language studies published after 1996. Adverse events of interest included rates of early failure, time to revision, revision, reoperation, dislocation, infection/sepsis, femoral neck fracture, mortality, and postoperative component alignment. Revision rates were compared with those from four national joint replacement registries. Results were reported as adverse event rates per 1000 person-years stratified by device market status (in use and discontinued). Comparisons between event rates of metal-on-metal hip resurfacing and THA are made using a quasilikelihood generalized linear model. We identified 7421 abstracts, screened and reviewed 384 full-text articles, and included 236. The most common study designs were prospective cohort studies (46.6%; n = 110) and retrospective studies (36%; n = 85). Few randomized controlled trials were included (7.2%; n = 17).

RESULTS

The average time to revision was 3.0 years for metal-on-metal hip resurfacing (95% CI, 2.95-3.1) versus 7.8 for THA (95% CI, 7.2-8.3). For all devices, revisions and reoperations were more frequent with metal-on-metal hip resurfacing than THA based on point estimates and CIs: 10.7 (95% CI, 10.1-11.3) versus 7.1 (95% CI, 6.7-7.6; p = 0.068), and 7.9 (95% CI, 5.4-11.3) versus 1.8 (95% CI, 1.3-2.2; p = 0.084) per 1000 person-years, respectively. This difference was consistent with three of four national joint replacement registries, but overall national joint replacement registries revision rates were lower than those reported in the literature. Dislocations were more frequent with THA than metal-on-metal hip resurfacing: 4.4 (95% CI, 4.2-4.6) versus 0.9 (95% CI, 0.6-1.2; p = 0.008) per 1000 person-years, respectively. Adverse event rates change when discontinued devices were included.

CONCLUSIONS

Revisions and reoperations are more frequent and occur earlier with metal-on-metal hip resurfacing, except when discontinued devices are removed from the analyses. Results from the literature may be misleading without consistent definitions, standardized outcome metrics, and accounting for device market status. This is important when clinicians are assessing and communicating patient risk and when selecting which device is most appropriate for individual patients.

Lower rates of dislocation with increased femoral head size after primary total hip replacement

Increased femoral head size may reduce dislocation rates following total hip replacement. The National Joint Registry for England and Wales has highlighted a statistically significant increase in the use of femoral heads ≥ 36 mm in diameter from 5% in 2005 to 26% in 2009, together with an increase in the use of the posterior approach. The aim of this study was to determine whether rates of dislocation have fallen over the same period. National data for England for 247 546 procedures were analysed in order to determine trends in the rate of dislocation at three, six, 12 and 18 months after operation during this time. The 18-month revision rates were also examined.

Between 2005 and 2009 there were significant decreases in cumulative dislocations at three months (1.12% to 0.86%), six months (1.25% to 0.96%) and 12 months (1.42% to 1.11%) (all p < 0.001), and at 18 months (1.56% to 1.31%) for the period 2005 to 2008 (p < 0.001). The 18-month revision rates did not significantly change during the study period (1.26% to 1.39%, odds ratio 1.10 (95% confidence interval 0.98 to 1.24), p = 0.118). There was no evidence of changes in the coding of dislocations during this time.

These data have revealed a significant reduction in dislocations associated with the use of large femoral head sizes, with no change in the 18-month revision rate.

Return to theatre following total hip and knee replacement, before and after the introduction of rivaroxaban: a retrospective cohort study

Rivaroxaban has been recommended for routine use as a thromboprophylactic agent in patients undergoing lower-limb arthroplasty. However, trials supporting its use have not fully evaluated the risks of wound complications. This study of 1048 total hip/knee replacements records the rates of return to theatre and infection before and after the change from a low molecular weight heparin (tinzaparin) to rivaroxaban as the agent of chemical thromboprophylaxis in patients undergoing lower-limb arthroplasty. During a period of 13 months, 489 consecutive patients undergoing lower-limb arthroplasty received tinzaparin and the next 559 consecutive patients received rivaroxaban as thromboprophylaxis. Nine patients in the control (tinzaparin) group (1.8%, 95% confidence interval 0.9 to 3.5) returned to theatre with wound complications within 30 days, compared with 22 patients in the rivaroxaban group (3.94%, 95% confidence interval 2.6 to 5.9). This increase was statistically significant (p = 0.046). The proportion of patients who returned to theatre and became infected remained similar (p = 0.10). Our study demonstrates the need for further randomised controlled clinical trials to be conducted to assess the safety and efficacy of rivaroxaban in clinical practice, focusing on the surgical complications as well as the potential prevention of venous thromboembolism.

Does bone quality predict loosening of cemented total hip replacements?

We matched 78 patients with a loose cemented Charnley Elite Plus total hip replacement (THR) by age, gender, race, prosthesis and time from surgery with 49 patients with a well-fixed stable hip replacement, to determine if poor bone quality predisposes to loosening. Clinical, radiological, biomechanical and bone mineral density indicators of bone quality were assessed.

Patients with loose replacements had more pain, were more likely to have presented with atrophic arthritis and to have a history of fragility fracture, narrower femoral cortices and lower peri-prosthetic or lumbar spine bone mineral density (all t-test, p < 0.01). They also tended to be smokers (chi-squared test, p = 0.08). Vitamin-D deficiency was common, but not significantly different between the two groups (t-test, p = 0.31)

In this series of cemented hip replacements performed between 1994 and 1998, aseptic loosening was associated with poor bone quality. Patients with a THR should be screened for osteoporosis and have regular radiological surveillance.

Outcome of Charnley total hip replacement across a single health region in England

Using the Trent regional arthroplasty register, we analysed the survival at ten years of 1198 consecutive Charnley total hip replacements carried out across a single health region of the United Kingdom in 1990. At ten years, information regarding outcome was available for 1001 hips (83.6%). The crude revision rate was 6.2% (62 of 1001) and the cumulative survival rate with revision of the components as an end-point was 93.1%. At five years, a review of this series of patients identified gross radiological failure in 25 total hip replacements which had previously been unrecognised. At ten years the outcome was known for 18 of these 25 patients (72%), of whom 13 had not undergone revision.

This is the first study to assess the survival at ten years for the primary Charnley total hip replacement performed in a broad cross-section of hospitals in the United Kingdom, as opposed to specialist centres. Our results highlight the importance of the arthroplasty register in identifying the long-term outcome of hip prostheses.

Epidemiology of dislocation after total hip arthroplasty

Instability after total hip arthroplasty is an important complication. It usually occurs in the immediate postoperative period, but the risk also increases with time. There are numerous surgical treatment options, but they have relatively unpredictable outcomes. Numerous factors are associated with dislocation, but research has mainly focused on surgical factors. Epidemiological factors remain the subject of much debate. We aimed to establish the most significant epidemiological factors in Scotland and in particular the dislocation rate in neuromuscular conditions. The Scottish National arthroplasty nonvoluntary registry is based on SMR01 records (Scottish Morbidity Record) data. We analyzed the Scottish National Arthroplasty Project to find patients' dislocation rates up to 1 year postoperatively for surgeon volume, age, gender, previous surgery, diagnosis, and followup duration. There were 14,314 total hip arthroplasties performed from April 1996 to March 2004 with an annual incidence of dislocation of 1.9%. We found an association between rate of dislocation with age, surgical volume, and previous fracture. However, there was no increase in the rate of dislocation associated with gender or with diagnoses of stroke or Parkinson's disease. Our prognostic assessment of dislocation risk allows assessment for methods of reducing dislocation in high risk patients.

Bacterial contaminants and antibiotic prophylaxis in total hip arthroplasty

We have investigated the contaminating bacteria in primary hip arthroplasty and their sensitivity to the prophylactic antibiotics currently in use. Impressions (627) of the gloved hands of the surgical team in 50 total hip arthroplasties were obtained on blood agar. The gloves were changed after draping, at intervals of 20 minutes thereafter, and before using cement. Changes were also undertaken whenever a visible puncture was detected. The culture plates were incubated at 37°C for 48 hours. Isolates were identified and tested for sensitivity to flucloxacillin, which is a recognised indicator of sensitivity to cefuroxime. They were also tested against other agents depending upon their appearance on Gram staining.

We found contamination in 57 (9%) impressions and 106 bacterial isolates. Coagulase-negative staphylococci were seen most frequently (68.9%), but we also isolated Micrococcus (12.3%), diphtheroids (9.4%), Staphylococcus aureus (6.6%) and Escherichia coli (0.9%). Of the coagulase-negative staphylococci, only 52.1% were sensitive to flucloxacillin and therefore to cefuroxime. We believe that it is now appropriate to review the relevance of prophylaxis with cefuroxime and to consider the use of other agents.

Pain and satisfaction after hip replacement: The patients perspective at 5 - 12 years

We present the results of a postal evaluation of 1700 hip replacements performed in 1560 patients at a specialist joint replacement centre. This 5 12 year follow-up assesses the patients perspective of satisfaction, pain levels, revision and dislocation rates, subjective issues related to the prosthetic hip and limitations to daily activities. Our adjusted response rate was 81.4%, with 89.2% of the respondents being satisfied with their hip replacement; 4.1% were dissatisfied, and 5.0% were unsure. 79% of patients reported no pain or slight pain, 14.5% had moderate pain and 2.6% had severe pain. 4.6% of the hip replacements had been revised, and 4.1% had dislocated. The hip was felt to be a limiting factor in their life by 18.4% of patients. The use of a questionnaire has provided long-term follow-up data at far less cost and considerably less inconvenience to the patient than a clinical review. We conclude that pain and patient satisfaction could be used as a simple screening tool for the vast majority of the patients. In those that have moderate or severe pain or express a lack of satisfaction for any reason, further clinical and radiological assessments could be carried out. (Hip International 2005; 15: 112-8).

Results of hybrid total hip replacement and resurfacing - is there a difference?

Hip resurfacing has in recent years become increasingly popular as an arthroplasty technique, particularly amongst younger patients with more active lifestyles. The procedure has been heralded as a more conservative option, aimed at those wishing to continue strenuous work and recreational activities. Little evidence has appeared in the literature however, either with the results of resurfacing or comparing resurfacing to conventional total hip arthroplasty. We compare the outcomes of a consecutive series of hybrid hip resurfacings against a similar series of conventional hybrid hip arthroplasties. In our series there was no difference in operation time, blood loss, or modified Harris Hip score at 12 months postoperatively. There was a small decrease in length of stay, which was not clinically significant. We conclude that whilst it has been previously shown that there is an overall preservation of bone stock following resurfacing arthroplasty, there is no evidence to back additional claimed benefits. (Hip International 2004; 14: 169-73).

Effect of radiation, heat, and aging on in vitro wear resistance of polyethylene

Radiation cross-linking increases the wear resistance of polyethylene used in total hip replacement. Radiation also generates residual free radicals, which are detrimental to long-term properties of polyethylene. Two approaches are used to stabilize the residual free radicals and terminally sterilize the components. One is postirradiation annealing with gas sterilization and the other is postirradiation melting with gamma sterilization in nitrogen. The hypothesis of the current study is that postirradiation annealing followed by gamma sterilization in nitrogen will result in more free radicals in polyethylene than gamma sterilization either in air or in nitrogen alone. To test this hypothesis, concentration of residual free radicals was quantified in polyethylene that was annealed and gamma sterilized in nitrogen and control polyethylenes gamma sterilized in air versus in nitrogen. Three crosslinked polyethylenes that were melted and gas sterilized also were included in the study. The effects of residual free radicals were studied by accelerated aging. Oxidation levels and weight loss in bidirectional pin-on-disk tests were determined before and after aging. Polyethylene that was subjected to postirradiation annealing and gamma sterilization resulted in 58% more residual free radicals than control polyethylenes. Weight loss of the annealed polyethylene increased by 16-fold on accelerated aging and had three times higher oxidation levels than that measured in control polyethylenes after aging. In contrast, polyethylenes that were stabilized with postirradiation melting and terminally gas sterilized showed no detectable residual free radicals. Accelerated aging did not affect the weight loss and oxidation levels of melted polyethylenes.

Femoral head sizes larger than 32 mm against highly cross-linked polyethylene

The advent of highly cross-linked ultrahigh molecular weight polyethylene, which shows extremely low wear independent of head size in vitro, allows for the reevaluation of the use of femoral heads larger than 32 mm. The current authors discuss information that supports this hypothesis. The supporting information includes in vitro wear testing and in vitro anatomic studies, and prior clinical studies in which large femoral heads were used.

Nice hips: shame about the conclusions

In April 2000 the National Institute for Clinical Excellence (NICE) issued their first appraisal in the field of surgery, "Guidance on the selection of prostheses for primary total hip replacement". NICE has already been heavily criticised for its recommendations in the field of medicine, due to its perceived role in rationing healthcare. This paper examines the conclusions of the appraisal committee (which included only two orthopaedic surgeons), the evidence on which they drew their conclusions and the evidence that was overlooked. We conclude that it is not clear how they determined the important ten-year benchmark and that they over-emphasise the benefits of cheaper cemented prostheses, failing to fully consider the evidence for the more expensive uncemented and hybrid combinations. (Hip International 2002; 12: 334-7).

Midterm outcome of the plasma cup in total hip arthroplasty

One hundred and twenty eight primary total hip arthroplasties (THA) in 104 patients were reviewed to assess mid-term survivorship and clinical outcome of the Plasma cup. Outcome was evaluated clinically, radiographically, and by self-administered questionnaires. Patient mean age at surgery was 51 years, and 52 THAs (41%) were performed for secondary arthritis. Prior to surgery the median Merle DAubigne score was 8. At 59 (standard deviation 18) months this score had improved to 17, and the median Harris hip score was 85. The mean annual polyethylene wear rate was 0.14mm/year. There were no instances of aseptic loosening but 2 cups had small, focal osteolytic lesions at the site of screw holes. Three cups were revised, two for recurrent dislocations, and one for infection. Cup survivorship at 5 years was 97% (Kaplan-Meier).This data suggests that the Plasma cup performs well in the mid-term and may be used safely in a young population with a high incidence of secondary osteoarthritis. (Hip International 2002; 2: 119-25).

Instability in primary total hip arthroplasty with the direct lateral approach

Instability after a total hip arthroplasty is a serious complication. Dislocation rates as much as 6.5% after posterior approaches have been reported within the past decade. For this reason, the authors use the direct lateral approach for primary and revision total hip arthroplasties. A review of the arthroplasty database yielded 1515 primary total hip arthroplasties done via a direct lateral approach in 1333 patients. These arthroplasties were done within a 10-year period and patients with followup data less than 12 months were excluded. At the most recent examination, 11.6% of the patients had a moderate or severe limp and 2.5% had severe heterotopic ossification. Only six hips (0.4%) had a dislocation or episode of instability. Three patients had more than one dislocation and required revision surgery. The results of the current study show that dislocation after primary total hip arthroplasty almost can be eliminated using the direct lateral approach. The associated risks of heterotopic ossification or limp are acceptable.

Innovation in total hip replacement--when is new better?

Although many designs of total hip replacement have high success rates at followup times of 10 years and more, new designs continue to be introduced. Some of these designs are similar to what is available already, but may offer advantages such as additional sizes or improved materials. In such cases, a key question is whether the new implant will produce the best possible results for routine use. Rather than simply relying on long-term followup data, which would eliminate the widespread use of a new device for a long time, it is suggested that the vast experience and knowledge of the orthopaedic community should be used. The proposal is that an authoritative group of individuals formulate a specification of the design features of total hip replacement which produce successful results. A second key question is how to be reasonably certain that a device with significantly new features, materials or techniques, is better and whether and when it should be used, either routinely or for specific indications. The proposal is that federal funding should be available to the research community for the specification and development of extensively researched and validated test methods. A point which is applicable to all innovations is that rather than relying on only one test or on a limited number of tests to validate the device, the Design Method must be used. This method involves the formulation of a methodical series of tests, preclinical and clinical, covering all combinations of use of the device. There are no simple answers to validating a design, but there are positive signs that new innovations are being introduced more carefully than in the past, and that many of these innovations will lead to improved long-term results.