Issues relating to long-term follow-up in hip arthroplasty surgery: a review of 598 cases at 7 years comparing 2 prostheses using revision rates, survival analysis, and patient-based measures

Trends in Orthopedic Fracture and Injury Severity: A Level I Trauma Center Experience

The purpose of this study was to define the trends in fracture complexity and overall injury severity of orthopedic trauma patients at a level I trauma center. A retrospective review of a prospectively collected trauma database was performed to determine the Injury Severity Score (ISS) and AO/OTA classification of the most common fractures among all patients presenting from 1995 to 1999 and from 2008 to 2012. Inclusion criteria were lower extremity fractures of the femur and tibia and pelvic fractures within the years of interest. Exclusion criteria were age younger than 18 years, pathologic fractures, and insufficient medical records to determine ISS or AO/OTA classification. The total number of fractures increased from 4869 between 1995 and 1999 to 5902 between 2008 and 2012. There was an increase in the percentage of lower extremity periarticular fractures (20.7% to 23.4%, P<.001) and the percentage of pelvic and acetabular fractures (32.7% to 39.9%, P<.001) and a decrease in the percentage of lower extremity extra-articular fractures (46.6% to 36.7%, P<.001). The ratios of tibial pilon and plateau fractures relative to extra-articular tibial fractures increased from 0.29 to 0.60 (P<.001) and from 0.49 to 0.81 (P<.001), respectively. The average ISS had increased from 2008 to 2012 compared with from 1995 to 1999 (19.2 vs 15.1, P<.001). The complexity of certain lower extremity fractures and the severity of injury of patients treated at this referral institution are high and continue to increase. As US health care economics continue to change, with provider and hospital reimbursements shifting toward a patient outcomes basis with potential penalties for complications and readmissions, hospitals and providers must recognize these trends. Trauma centers must continue to measure the complexity of fracture care provided to properly risk-stratify their patient population. [Orthopedics. 2018; 41(2):e211-e216.].

Resurfacing hip replacement and cemented total hip replacement have equivalent outcome at one year in a disease matched population: a case-control study of patient reported outcome measures

Resurfacing hip replacement has demonstrated good survival and outcomes for cohorts of younger male patients, but few controlled studies exist. In this study we compared patient reported outcome measures and satisfaction scores at one year following resurfacing hip replacement in 69 male patients with two control groups of equal numbers undergoing cemented total hip replacement: aged-matched patients and disease matched patients. At one year we found no difference in improvement in patient reported outcome measures between patients undergoing resurfacing hip replacement and disease matched patients, whereas patients undergoing resurfacing hip replacement had a statistically significant improvement in Oxford Hip Score compared to the age-matched controls (p<0.047) although this was below the minimally clinically detectable difference. Resurfacing hip replacement and total 
hip replacement both confer increase in patient reported outcome scores and high patient satisfaction at one year. The results of this study will allow better counselling of patients and help inform 
treatment decisions.

Mid-term outcome of total hip replacement using the posterior approach for displaced femoral neck fractures

Treatment of displaced femoral neck fractures with total hip replacement (THR) in appropriately selected patients has become more widely accepted. The use of the posterior approach for THR remains controversial due to concerns regarding dislocation, the cause of which is multi-factorial. This study is a single surgeon series of 45 consecutive active, healthy patients (mean age 78 years) with displaced femoral neck fractures treated with THR through a posterior approach. Large diameter heads (32mm in 47%, ≥36mm in 48% of patients) and an anatomic posterior soft tissue repair were utilised to minimize the risk of dislocation. Outcomes were reported at a mean of 2 and 6 years. The mortality rate was 13% at 2 years and 40% at 6 years. All revision surgery (4.4%) was performed for dislocations which occurred in 6.7% of patients. Good VAS pain, OHS and SF-12 scores were reported both at 2 and 6 years. Patient satisfaction with the results of surgery was high.

Is total hip arthroplasty after hip arthrodesis as good as primary arthroplasty?

BACKGROUND

Conversion of hip arthrodesis to a THA reportedly provides a reasonable solution, improving function, reducing back and knee pain, and slowing degeneration of neighboring joints associated with a hip fusion. Patients generally are satisfied with conversion despite the fact that range of mobility, muscle strength, leg-length discrepancy (LLD), persistence of limp, and need for assistive walking aids generally are worse than those for conventional primary THA.

QUESTIONS/PURPOSES

We compared THA after hip arthrodesis and primary THA to determine whether these procedures would be associated with similar functional scores, maintenance of scores with time, complications and failures, survivorship of the arthroplasty, and patient satisfaction.

PATIENTS AND METHODS

We retrospectively matched 48 patients undergoing conversion of a fused hip to a THA between January 1980 and January 2000, with 50 patients receiving a primary THA during the same period. We prospectively followed all patients between January 2000 and January 2010. The changes in function and pain after THA were compared between the two cohorts using the Harris hip score (HHS) and the Rosser Index Matrix (RIM). The Oxford hip score (OHS) and the SF-36 also were used to assess quality of life (QOL) during followup. Complications were collected and survivorship of the THA was evaluated. Patient satisfaction was assessed using the Robertsson and Dunbar questionnaire. The minimum followup was 10 years (mean, 17 years; range, 10-29 years).

RESULTS

At last followup, hip function and health-related QOL were similar for patients having conversion of hip arthrodesis to THA and for patients having a routine THA. Scores diminished overall in the two groups between 2000 and 2010, but without a difference for the HHS, RIM QOL, and OHS in the study cohort. The rate of complications, THA survival, and patient satisfaction were similar in both groups.

CONCLUSIONS

Conversion of hip arthrodesis to a THA provides substantial improvement of hip function and health-related QOL, with an acceptable rate of complications, good expectancy of survival for the arthroplasty, and high level of patient satisfaction comparable to those of primary THA.

LEVEL OF EVIDENCE

Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Patient-reported outcome following metal-on-metal resurfacing of the hip and total hip replacement

Patient-reported outcome and satisfaction scores have become increasingly important in evaluating successful surgery. This case-matched control study compared patient-reported outcome and satisfaction data following hip resurfacing and total hip arthroplasty. Thirty-three consecutive patients selected for hip resurfacing were compared with 99 patients undergoing cemented total hip replacement (THR), matched for age, sex and pathology. Participants completed a Short-Form 12 Health Survey (SF-12) and Oxford Hip Score questionnaire preoperatively and 6 months post operatively with an additional patient satisfaction questionnaire. There was no difference in length of hospital stay. While both groups reported improved outcome scores, multivariate regression analysis did not demonstrate any significant benefit for one group over the other. Both groups reported high levels of satisfaction, which tended to be better in patients undergoing hip resurfacing.

Documentation of hip prostheses used in NorwayA critical review of the literature from 1996–2000

We have conducted a systematic review of the scientific literature concerning outcome and clinical effectiveness of prostheses used for primary total hip replacement (THR) in Norway. The study is based on two Health Technology Assessment reports from the UK (Faulkner et al. 1998, Fitzpatrick et al. 1998), reviewing the literature from 1980 to 1995. Using a similar search strategy, we have evaluated the literature from 1996 through 2000. We included 129 scientific and medical publications which were assessed according to a specific appraisal protocol. The majority (72%) were observational studies, whereas only 9% were randomized studies. We could not retrieve any peer-reviewed documentation for one third of the implants. The Charnley prosthesis had by far the best and most comprehensive evidence base with better than 90% implant survival after about 10 years. Survival of the Charnley prosthesis declines by about 10% during each of the two following decades. Except for the Charnley and Lubinus IP, no other prosthesis on the market in Norway has given long-term results (> 15 years). 5 other cemented implants have given comparable results at about 10 years of follow-up. Some uncemented stems have shown promising medium-term outcome, but no combination of uncemented cup and stem fulfilled the benchmark criterion of > or = 90% implant survival at 10 years, which we propose as a minimum requirement for unrestricted clinical use for prostheses used in primary THR. New or undocumented implants should be introduced through a four-step model including preclinical testing, small series evaluated by radiosterometry, randomized clinical trial involving comparison with a well-documented prosthesis, and finally, surveillance of clinical use through registers.

Birmingham hip resurfacing arthroplasty

We report the outcome at a minimum of five years of 110 consecutive metal-on-metal Birmingham Hip Resurfacing arthroplasties in 98 patients. The procedures were performed between October 1999 and June 2002 by one surgeon. All patients were followed up clinically and radiologically. The mean follow-up was 71 months (60 to 93). Revision of either component was defined as failure.

The mean Harris Hip score at follow-up was 96.4 (53 to 100). The mean Oxford hip score was 41.9 (16 to 57) pre-operatively and 15.4 (12 to 49) post-operatively (p < 0.001). The mean University of California Los Angeles activity score was 3.91 (1 to 10) pre-operatively and 7.5 (4 to 10) post-operatively (p < 0.001).

There were four failures giving a survival at five years of 96.3% (95% confidence interval 92.8 to 99.8). When applying a new method to estimate narrowing of the femoral neck we identified a 10% thinning of the femoral neck in 16 hips (14.5%), but the relevance of this finding to the long-term outcome remains unclear.

These good medium-term results from an independent centre confirm the original data from Birmingham.

Cone femoral prosthesis for osteoarthritis of the hip with femoral dysplasia

PURPOSE

To assess the clinical and radiological outcomes of total hip replacement (THR) using the cone femoral prosthesis.

METHODS

Four men and 15 women (26 hips) aged 19 to 78 (mean, 45) years underwent THR for osteoarthritis of the hip with femoral dysplasia using the cone femoral prosthesis. Only 17 patients (24 hips) were available for review. Pain and functional limitation were assessed using the Oxford hip score. Stable fixation by bone ingrowth was defined as no subsidence or radiolucent lines around the prosthesis.

RESULTS

The mean follow-up duration was 50 (range, 25-92) months. The mean Oxford hip score improved from 44 (range, 32-54) preoperatively to 17 (range, 12-28) at the latest follow-up. Prosthesis survival was 100%. All prostheses showed stable integration with bony ingrowth and no measurable subsidence. 15 hips had excessive anteversion of 25 to 90 degrees. No patient had venous thromboembolism, deep prosthetic infections or dislocations.

CONCLUSION

The cone prosthesis is less complex and expensive than the modular prosthesis. The early functional and radiological outcomes were excellent, with marked improvement in pain and function. This constitutes effective treatment for osteoarthritis of the hip with femoral dysplasia.

Factors affecting aseptic loosening of 4750 total hip arthroplasties: multivariate survival analysis

BACKGROUND

Total hip arthroplasty is a successful surgery, that fails at a rate of approximately 10% at ten years from surgery. Causes for failure are mainly aseptic loosening of one or both components partially due to wear of articular surfaces and partially to design. The present analysis aimed to identify risk factors and quantify their effects on aseptic failure.

METHODS

Multivariate survival analysis was applied to 4,750 primary total hip arthroplasties performed between 1995 and 2000.

RESULTS

The survival of the prosthesis is affected by gender, age, pathology, type of the prosthesis and skill of the. The worst conditions are male patients, younger than 40 years, affected by sequelae of congenital diseases, operated by a who performed less than 400 total hip artroplasty in the period. Furthermore, cemented cups and stems (less expensive) have a higher risk of failure compared with uncemented ones (more expensive).

CONCLUSION

The only variable that affects survival and that can be modified by is the type of prosthesis: a lower cost is associated to a higher risk. Results concerning the risk associated with cemented components are partially in disagreement with studies performed in countries where cemented prostheses are used more often than uncemented ones.

The Oxford hip score: the patient's perspective

BACKGROUND

In the last 25 years, assessment of orthopaedic intervention has become patient focused, with the development of self-completion patient-centred outcome measures. The Oxford hip score (OHS) is a joint specific outcome measure tool designed to assess disability in patients undergoing total hip replacement (THR). Although the psychometric properties of the OHS have been rigorously examined, there is little research on the patient's perspective of the OHS. Therefore, the aim of this study is to assess whether the OHS is an adequate disability measure from the patient's perspective using qualitative analysis of annotations written on the OHS by patients.

METHODS

In total, 276 orthopaedic patients completed an OHS between April 2004 and May 2005. One hundred and fifty six pre-operative patients listed for a THR completed the OHS during a pre-admission assessment clinic, and 120 post-operative patients completed the OHS postally in the home setting. Patient's unprompted annotations in response to the questions on the OHS were recorded and grouped into thematic categories.

RESULTS

In total, 46 (17%) patients made 52 annotations when completing the OHS. These annotations identified five main areas of difficulty that patients experienced: lack of question clarity (particularly concerning the use of aids), difficulty in reporting measurements of pain, restrictive and irrelevant questions, the influence of co-morbidities on responses, and double-barrelled questions.

CONCLUSION

Although the OHS is a useful short tool for the assessment of disability in patients undergoing THR, this study identified several problem areas that are applicable to patient-centred outcome tools in general. To overcome these current limitations, further work is underway to develop a more individualised patient-centred outcome measure of disability for use in patients with osteoarthritis.

The Oxford hip scores for primary and revision hip replacement

We have used the Oxford hip score to monitor the progress of 1908 primary and 279 revision hip replacements undertaken since the start of 1995. Our review programme began in early 1999 and has generated 3900 assessments.

The mean pre-operative scores for primary and revision cases were 40.95 and 40.11, respectively. The mean annual score for primary replacement at between 12 and 84 months ranged between 20.60 and 22.57. A comparison of cross-sectional and longitudinal data showed no significant differences. All post-operative reviews showed a significant improvement (p ≤ 0.0001). The 50- to 60-year-old group scored significantly better than the patients over 80 years of age up to 48 months (p < 0.01). A subgroup of 826 National Health Service (NHS) and 397 private patients, treated by the senior author (2292 Oxford assessments), had a higher (i.e. worse) mean pre-operative score for the NHS patients (p ≤ 0.001). The private patients scored better than the NHS group up to 84 months (p < 0.05). Patients treated by a surgeon performing more than 100 replacements each year had a significantly better outcome up to five years than those operated on by surgeons performing fewer than 20 replacements each year. The age of the patients at the time of operation, and their pre-operative level of disability, have both been identified as affecting the long-term outcome. Awareness of the influence of these factors should assist surgeons to provide balanced advice.

The Oxford hip and knee outcome questionnaires for arthroplasty

The Oxford hip and knee scores are used to measure the outcome after primary total hip and knee replacement. We propose a new layout for the instrument in which patients are always asked about both limbs. In addition, we have defined an alternative scoring method which accounts for missing data. Over a period of 4.5 years, 4086 (1423 patients) and 5708 (1458 patients) questionnaires were completed for hips and knees, respectively. The hip score had a pre-operative median of 70.8 (interquartile range (IQR) 58.3 to 81.2) decreasing to 20.8 (IQR 10.4 to 35.4) after one year. The knee score had a pre-operative median of 68.8 (IQR 56.2 to 79.2) decreasing to 29.2 (IQR 14.6 to 45.8). There was no further significant change in either score after one year. As a result of the data analysis, we suggest that the score percentiles can be used as a standard for auditing patients before and after operation.

Birmingham hip resurfacing arthroplasty

We report the survival at five years of 144 consecutive metal-on-metal resurfacings of the hip implanted between August 1997 and May 1998. Failure was defined as revision of either the acetabular or femoral component for any reason during the study period. The survival at the end of five years was 98% overall and 99% for aseptic revisions only. The mean age of the patients at implantation was 52.1 years.

Three femoral components failed during the first two years, two were infected and one fractured. A single stage revision was carried out in each case. No other revisions were performed or are impending. No patients were lost to follow-up. Four died from unrelated causes during the study period.

This study confirms that hip resurfacing using a metal-on-metal bearing of known provenance can provide a solution in the medium term for the younger more active adult who requires surgical intervention for hip disease.

Two- to 12-year evaluation of cementless Buechel-Pappas total hip arthroplasty

A unique, straight-stemmed, proximally porous-coated, modular hip arthroplasty system, coated with thin-film (5- to 9-microm), titanium-nitride ceramic, was used clinically in 130 hip arthroplasties in 117 patients who were followed over a 2- to 12-year interval (mean, 6.45 years). Harris Hip Scores demonstrated 82.3% excellent, 15.4% good, 2.3% fair, and 0% poor results. Thigh pain that limited activities of daily living was seen in 0.8% (1 of 130) hips. Kaplan-Meier survival estimates using an endpoint of revision of any component for any reason demonstrated an overall survival of 95.5% during the 12-year interval. Cementless fixation survivorship of the acetabular and femoral components was 98.5% during the 12-year interval.

Results of displaced subcapital fractures treated by primary total hip replacement

We present morbidity, mortality and functional outcome in mobile, socially independent and alert patients with displaced subcapital hip fractures, treated by primary total hip replacement (THR). Fifty-one consecutive socially independent and mentally alert patients with displaced subcapital fractures were treated by primary THR, from April 1997 to March 2000, at a single hospital. Most patients were female (45/51) with an average age of 74 years. Patient hospital records were reviewed and patients interviewed by telephone. Functional outcome was assessed using Oxford hip score (OHS), short form 12 (SF12), and patient satisfaction. This study had a mean follow-up of 33 months (range 20-54). One patient with early dislocation went on to have recurrent dislocations. Two patients underwent revision surgery. Three patients died within 1 year of sustaining fracture. Function was comparable to elective THR in osteoarthritic patients. OHS correlated well with both SF12 and patient satisfaction. This study has the lowest reported dislocation rate (2%) and an acceptable 1-year mortality (6%) confirming the place of primary THR in treatment of these selected patients with a displaced hip fracture. The OHS proved a valuable instrument to assess function following THR in fracture patients.

Comparing Alternative Rasch-Based Methods vs Raw Scores in Measuring Change in Health

OBJECTIVES

To compare alternative Rasch-based approaches to the assessment of change over time through the example of an outcome measure used in total hip replacement surgery.

SUBJECTS

Preoperative data were collected on 1424 patients receiving total hip replacement surgery; 1221 (86%) were sent follow-up questionnaires 1 year after surgery.

MEASURES

The 12-item Oxford Hip Score (OHS) questionnaire administered preoperatively and 1-year postoperatively.

METHODS

Subscales of the OHS for pain and functional impairment were examined for unidimensionality and item invariance. Two criteria were used to examine Rasch-based measurement of the 2 subscales. Advantages of Rasch measurement were examined in terms of whether it produced improved discrimination of outcomes of patients (1) undergoing different levels of complexity of surgery; and (2) reporting different retrospective judgments of the success of their surgery. Using the method of relative precision in relation to groups of patients distinguished in these 2 ways, change scores using Likert scoring methods were compared with 2 Rasch scoring methods: (1) separate analyses of the 2 time points; and (2) a common scale analysis obtained by stacking patients from the 2 time points.

RESULTS

Less evidence for item invariance over time was found for the pain subscale. Other evidence supported treating subscales as unidimensional. Whichever Rasch scoring method was used, some gains in precision over standard Likert scoring were obtained in discriminating between groups of patients.

CONCLUSIONS

The evidence from the current study suggests that there may be some gains in sensitivity to change of outcome measures from different Rasch-based scoring approaches.

Demographic factors affecting long-term outcome of total hip arthroplasty

We report the outcome of total hip arthroplasty (THA) in a cohort of patients with complete long-term radiographic and clinical followup information from our database of more than 48,000 primary hip replacements. The purpose of the study was to evaluate the influence of various demographic factors and patient comorbidity (Charnley classification) on the long-term outcome of THA. The cohort was comprised of 25,990 total hip replacements (THRs) in 10,243 (46.6%) men and 11,754 (53.4%) women with a median age of 66 years (range, 20-96 years) at the time of arthroplasty. Our study confirmed that THA has an impressive efficiency and reliability in alleviating pain and improving function for almost all of the patients. Furthermore, the results are enduring with more than 90% of patients being satisfied with the outcome at 15 years. Clinical outcome measures reach their maximum at 2 to 5 years after arthroplasty and thereafter they decline gradually. Furthermore, patient age, gender, body mass index, and main diagnosis all have an influence on specific functional parameters. The Charnley classification has the most profound effect on the overall functional status of patients.

Rasch scoring of outcomes of total hip replacement

We examined whether there are advantages in terms of outcome assessment of using Rasch methods of scoring the 12-item Oxford Hip Score questionnaire over conventionally summed scores. Data were collected on patients receiving total hip replacement surgery. Three patient groups were created according to surgery type: primary, revision, and re-revision; two groups were created according to satisfaction with surgery: very satisfied and dissatisfied. Analyses were performed to test the relative precision (RP) of Rasch scoring versus conventionally summed scores in discriminating the groups experiencing different types of surgery and level of satisfaction. At the 1-year follow-up, RP ratios favored the Rasch scoring method in both tests of discrimination. Considerable gains in precision were achieved with Rasch scoring methods when groups were compared in a cross-sectional way. Alternative approaches to scoring questionnaires should be investigated to better assess comparisons over time.

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).