We compare two applications of minimally invasive hip arthroplasty (MISTHA) with regards to early complication rate and consumption of health care resources. Complications are associated with both manifestations of MIS surgical technique. Two- incision MIS THA is associated with fewer days in hospital in comparison with one incision MIS THA, however requires a greater amount of operating room resources. This paper is among the first to compare two- incision with one incision MISTHA. Two- incision MISTHA may benefit efforts to reduce health resource utilization associated with hip arthroplasty procedures providing that operating room resource consumption and complication rates are not excessive.

A comparative cohort study to evaluate two-incision versus single-incision minimally invasive hip arthroplasty: assessment of early complication rate and health care resource utilization

To evaluate and compare two applications of minimally invasive hip arthroplasty (MISTHA) with regards to early complication rate and consumption of health care resources

One hundred and sixty-five patients received MISTHA from 2002–2004 at a tertiary referral hospital. Patients received two incision (sixty-six patients) or one incision surgery (ninety-nine patients) which was performed according to standard technique. T-test, chi square, fisher’s exact test were used to compare cohorts of MISTHA patients with regards to early complications and consumption of health care resources while in hospital.

At baseline the two cohorts were not different with regards to age, gender, comorbid status, BMI, and pre-operative WOMAC, Oxford-12, SF-12 (p> .05). Major and minor complication rates were similar in the two cohorts (p> .05). Utilization of operating room resources was greater with the two incision group (mean twentyfive minutes more OR time) however length of stay (mean two days less in hospital) and post-operative analgesic use was significantly reduced (p< .05). Complications and operating room resource consumption were highest early in the surgeons’ experience with these procedures.

Complications are associated with both manifestations of MIS surgical technique. Two- incision MISTHA is associated with fewer days in hospital, however requires a greater amount of operating room resources.

This paper is among the first to compare two- incision with one incision MISTHA. Two- incision MISTHA may benefit efforts to reduce health resource utilization associated with hip arthroplasty procedures providing that operating room resource consumption and complication rates are not excessive.

This study evaluated the effect of prosthetic patellar resurfacing on outcome of revision total knee arthroplasty. One hundred and twenty-six patients who underwent consecutive revision of total knee arthroplasty were identified. The status of the patella was ascertained post revision as to the presence or absence of patellar prosthesis. WOMAC, Oxford-12, SF-12 and patient satisfaction data were obtained at a minimum of two years follow-up. Follow-up was obtained in one hundred and ten patients. There was no significant difference between the two cohorts with regards to outcomes. A patellar prosthesis does not appear to significantly affect pain, function, or satisfaction outcomes following revision total knee arthroplasty.

The purpose of this study is to evaluate the effect of prosthetic patellar resurfacing on outcome of revision total knee arthroplasty in a matched cohort study.

The presence or absence of a patellar prosthesis does not appear to significantly affect pain, function, or satisfaction outcomes following revision total knee arthroplasty.

Attempting to resurface the patella in revision cases may not be worthwhile.

Follow-up was obtained in one hundred and ten patients (fifty-two with patellar component, fifty-eight bony shell), matched for age, sex and co-morbidity scores and followed for a minimum of two years. There was no significant difference between the two cohorts with regards to outcomes of WOMAC pain (mean seventy-two and sixty-five, p=0.17), WOMAC function (mean sixty-four and fifty-nine, p=0.26) scores, Oxford −12 (mean sixty-three and sixty-seven, p=0.2), SF-12 (mean forty and thirty-six, p=0.27) and satisfaction outcomes (mean eight and nine, p=0.07), (power of 0.8, beta=0.2).

From January 1997 to December 1999 one hundred and twenty-six patients who underwent consecutive revision total knee arthroplasty were identified. The status of the patella was ascertained post revision as to the presence or absence of patellar prosthesis. At a minimum of two years follow-up, pain and function were assessed by questionnaire for WOMAC, Oxford-12, SF-12 and patient satisfaction data. Co-morbidity, surgical exposure, HSS knee scores and ROM were also collected. Univariate and multivariate analyses were performed.

It is questionable whether patient’s pain, function and satisfaction are affected in revision total knee arthroplasty by patellar prosthetic resurfacing.

Funding: One or more of the authors has received funding from a commercial party. This was DePuy, Inc, Warsaw, IN.

A concern with diaphyseal-fitting cementless stems in revision total hip arthroplasty is intra-operative fractures. Two hundred and eleven patients consecutively underwent revision hip arthroplasty using Solution stems (DePuy, Warsaw, IN). Intra-operative fractures or perforations occurred in sixty-four patients (30% prevalence), with diaphyseal splits in thirty-nine patients (18% prevalence). Risk factors were pre-operative osteolysis, cortex to canal ratio, under-reaming the cortex and large diameter stems. The majority of diaphyseal linear cracks occurred at the distal end of extended trochanteric osteotomies during stem insertion. Intra-operative fracture is associated with an average two days longer length of stay (p< 0.05).

The purpose of this study was to determine the identification of the risk factors and outcomes of intra-operative fractures using a diaphyseal fitting revision stem.

There is an association of intra-operative fracture associated using a diaphyseal-fitting stem in revision total hip arthroplasty with a longer length of stay in hospital.

Identifying preoperative risk factors will allow avoidance of such fractures and prolonged hospital stay.

Intra-operative fractures or perforations occurred in sixty-four patients (30% prevalence) and thirty-nine patients (18% prevalence) sustained diaphyseal splits. Risk factors associated with intra-operative fracture were pre-operative osteolysis, a low cortex to canal ratio, under-reaming the cortex and the use of a large diameter stem. Surgical approach was not directly related to fracture occurrence but the majority of diaphyseal undisplaced linear cracks occurred at the distal end of extended trochanteric osteotomies during stem insertion. Cortical perforation occurred most often with cement removal. Duration of stay was on average two days longer (p< 0.05) for patients with an intraoperative fracture.

Two hundred and eleven patients who had undergone revision hip arthroplasty using the Solution stem (DePuy, Warsaw, IN) between December 1998 and March 2002 were identified. Patients who sustained an intra-operative fracture were compared to controls patients who underwent hip revision at the same time frame but with no fracture. Multiple factors were analyzed to see which were risk factors for intra-operative fractures.

There is a surprisingly high incidence of intra-operative fracture associated with using a diaphyseal-fitting stem in revision total hip arthroplasty. This was associated with a longer length of stay

Purpose: To examine whether neutral or valgus placement results in greater fracture strength ex vivo, when the femoral neck is notched superolaterally as sometimes occurs during hip resurfacing arthroplasty.

Methods: We loaded 10 paired fresh-frozen notched proximal cadaveric femora (8F/2M, 66 to 80 years) to failure. In each case, the right femur was implanted, using bone cement, with a machined resurfacing component aligned neutrally with respect to the femoral neck whereas the left femur was implanted at 10° valgus. The superolateral notch was 3 mm wide by 2 mm deep directly beside the component. Potted femurs were loaded to failure using an Instron materials testing machine. All 20 femora were scanned using Dual-Energy X-Ray Absorptiometry.

Results: The effect of neutral versus valgus placement was complex. (1) Two pairs slowly crushed; the remaining femurs exhibited a clear fracture. When only the fracture-type failures were analyzed, valgus placement resulted in fracture loads on average 22% higher than for neutral placement (paired t-test, p< 0.05). All femurs failed within the notch, as occurs clinically. (2) Femurs with high bone density (BMD> 0.65 g/cm2) showed a significant increase in fracture load (p< 0.05) whereas femurs with low BMD (< 0.65 g/cm2) were unaffected by component placement. BMD was highly correlated with fracture load (Pearson r=0.87, p=0.0003). (3) The greatest improvements occurred when the neck-shaft angle was relatively low, 128°–132°. (4) Two of ten femurs required larger head sizes at 10° valgus.

Conclusions: (1) Fracture load was primarily controlled by bone quality (BMD); (2) nevertheless, varus/valgus placement did affect the fracture load; (3) the magnitude and direction of this effect depended on fracture type, bone mineral density and the original neck-shaft angle; (4) for the level of bone quality typical of patients undergoing hip resurfacing, and for low-to-average neck-shaft angles (up to 132°), the fracture load for 10° valgus placement was significantly higher than for neutral placement. Funding: Other Education Grant

The purpose of this study is to evaluate the effect of prosthetic patellar resurfacing on outcome of revision total knee arthroplasty in a matched cohort study.

From January 1997 to December 1999 126 patients who underwent revision of total knee arthroplasty were identified. The status of the patella was ascertained post revision as to the presence or absence of patellar prosthesis. At a minimum of two years follow-up, pain and function were assessed by questionnaire for WOMAC, Oxford-12, SF-12 and patient satisfaction data. Co-morbidity, surgical exposure, HSS knee scores and ROM were also collected. Univariate and multivariate analysis were performed. Follow-up was obtained in 110 patients (52 with patellar component, 58 bony shell), matched for age (mean 70 and 67 years), sex and co-morbidity scores and followed for a minimum of two years. There was no significant difference between the two cohorts with regards to outcomes of WOMAC pain scores (mean 66 and 74, p=0.14), WOMAC function scores (mean 59 and 65, p=0.22), Oxford- 12 scores (mean 57 and 64, p=0.17), and satisfaction score outcomes (57 and 68, p=0.14). It remains controversial whether the patient’s pain, function and satisfaction are affected in revision total knee arthroplasty by patellar prosthetic resurfacing. Insufficient patellar bone stock may preclude prosthetic resurfacing in which case patel-loplasty is performed. From this series, the presence or absence of a patellar prosthesis does not appear to sig-nificantly affect pain, function, or satisfaction outcomes following revision total knee arthroplasty.

The prospective evaluation of two hundred and seven symptomatic total knee arthroplasties presenting for revision total knee arthroplasty is reported. On univariate analysis patients who had infection differed significantly (p< .001) from those without infection with regards to: elevated ESR, CRP, positive aspiration, and history of; revision procedure less than two years since last surgery, early wound problems, ongoing pain since index procedure, and discharging wound. On multivariate analysis elevated ESR or CRP, positive aspiration, pain since index procedure and early wound complications were significant predictors of infection (p< .05). These variables were then used to formulate an evidence-based multivariate predictive algorithm to assist the clinician in decision making prior to surgery.

Differentiating septic from aseptic failure of total knee arthroplasty on the basis of clinical features and diagnostic tests can be troublesome for the clinician. The purpose of this paper is to describe significant differences between cases of septic and aseptic failure of total knee arthroplasty. The incorporation of these variables into a practical multivariate clinical prediction algorithm can provide assistance in establishing the diagnosis of infection prior to revision knee arthroplasty.

A simple clinical prediction algorithm can assist in the diagnosis of infection in patients with painful total knee arthroplasty. Patients with five of five criteria have a 99% probability of infection whereas patients with zero of five criteria have a 1% probability of infection.

This is the first multivariate evidence-based clinical prediction algorithm presented for use in decision making prior to revision total knee arthroplasty. The surgeon can use the information derived from clinical and laboratory assessment to compute an approximate pre-operative probability of infection prior to surgery (see table).

On multivariate analysis elevated ESR or CRP, positive aspiration, pain since index procedure and early wound complications were significant predictors of infection (p< .05). These variables were then used to formulate an evidence-based multivariate predictive algorithm to assist in clinical decision making.

Prospective data was collected on two hundred and seven symptomatic knee arthroplasties presenting for revision arthroplasty. A multivariate logistic regression model was used to determine the probability of infection using five significant variables. Combinations of these five variables can provide the clinician with an estimate of the probability of infection prior to revision knee arthroplasty.

Please contact author for tables and/or charts.

Patient satisfaction is not uniform or consistent following revision total knee arthroplasty. This study evaluates ninety-nine patients with a self-administered patient satisfaction questionnaire at a minimum of two years following the revision procedure (1997–99) to determine differences between satisfied (sixty-six patients) and dissatisfied patients (thirty-three patients). Univariate analysis revealed that patients satisfied with their results were significantly different (p< .05) than dissatisfied patients with regards to post op scores including those of the WOMAC pain and function, oxford, and SF-12. Patients were not different with regards to (p> .05) age, comorbidity score, surgical approach, or sepsis as a reason for the revision procedure. Regression analysis demonstrated that gender, post-op WOMAC score, and pre-op arc of motion were significant determinants of satisfaction.

The purpose of this study is to evaluate determinants of patient satisfaction following revision total knee arthroplasty.

Patient satisfaction with revision knee surgery is most strongly associated with both pre and post-operative descriptors of knee function as well as gender.

Understanding the variables associated with satisfaction/dissatisfaction following revision knee arthroplasty may further assist ongoing research efforts to improve the outcomes of this procedure.

Univariate analysis revealed that patients satisfied with their results were significantly different (p< .05) than dissatisfied patients with regards to WOMAC pain and function score, oxford knee score, and SF-12. Patients were not different with regards to (p> .05) age, comorbidity score, surgical approach, or presence of sepsis as a reason for the revision procedure. Regression analysis demonstrated that gender, post-op WOMAC score, and pre-op arc of motion were significant determinants of satisfaction (p< .05).

A self-administered patient satisfaction survey was completed by ninety-nine patients at a minimum of two years following revision total knee arthroplasty. Fifty-nine patients were females and forty were males. Sixty-six patients were satisfied and thirty-three patients were dissatisfied with the outcome of their surgery at two years post-op. Univariate analysis and multivariate regression suggest that pre and post-operative joint function and gender are the most significant determinants of patient satisfaction

Purpose: Hip resurfacing techniques utilize mechanical jigs to align a femoral guide-pin that directs implant placement. Errors in alignment may lead to premature failure. The purpose of this study was to compare femoral guide-pin placement using a computer-assisted surgical (CAS) navigation system to a currently available manual alignment device.

Methods: A computer-assisted navigation system was developed by our group. Target guide-pin position was determined for each cadaveric hip from radiographs. A guide-pin was driven into each hip using either the CAS method or a manual alignment jig (Durom; Zimmer) by a novice or expert surgeon respectively. Radiographic pin position was compared to the target and accuracy was compared between the two techniques.

Results: Guide-pin insertion trajectory using the CAS system was significantly less variable in varus/valgus alignment than the mechanical jig (2.0° SD vs. 5.5° SD; p < 0.05). Ante/retroversion variability was also lower using CAS (4.4° SD vs. 7.7° SD) as was alignment error (CAS: 2.0° ± 2.2° SD valgus vs. Durom: 3.3° ± 5.5° SD varus, p=0.17; CAS: 0.1° ± 4.6° SD anteverted; Durom 3.2° ± 7.7° SD retroverted, p=0.48) but not significantly. Both methods proved accurate in placing the pin within 2 mm from the centre of the neck axis. Procedure time was similar between the two methods

Conclusions: Computer-assisted surgical navigation significantly improves reliability of guide-pin placement. This technique may help achieve better femoral implant alignment regardless of experience and contribute to improving hip resurfacing outcomes.

Funding : Other Education Grant

Funding Parties : Zimmer/UBC Research Fund

This prospective cohort study examined the relationship between waiting time for elective total hip arthroplasty (THA) and changes in pre- to post-operative quality of life. It included one hundred and forty-seven patients who entered the waiting list for primary THA with osteoarthritis. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire was used to assess patients at surgical consultation time (baseline) and one year post-operation. Baseline WOMAC score was a significant predictor for follow-up WOMAC score. Expedited access to THA results in a larger proportion of patients showing “better than expected” function at twelve months after the operation.

This study examined the relationship between waiting time for elective total hip arthroplasty (THA) and changes in pre- to post-operative quality of life.

Expedited access to THA results in a larger proportion of patients showing “better than expected” function at twelve months after the operation. The odds of a “better than expected” functional outcome decreased by 8% for each additional month on the wait list.

The study provides the estimates of decreased probability of “better than expected” outcome given a prolonged waiting time. Our study indicates that timely access to THA is needed for optimal post-operative outcome.

Baseline WOMAC score was a significant predictor for the follow-up WOMAC score in function (p=0.0005), pain (p=0.0036), and stiffness (p= 0.0004). Waiting for six months or less doubled the odds of achieving a “better than expected” functional outcome compared to longer waits (p= 0.05).

This prospective cohort study included one hundred and forty-seven patients who entered the waiting list for primary THA with osteoarthritis. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire was used to assess patients at the surgical consultation time (baseline) and one year post operation. Regression models were used to determine the “expected” outcome for a certain individual baseline score. By using expected HRQOL outcome, we identified patients whose benefit from THA is better than expected. Logistic regression models were used to assess the relationship between waiting time and the probability of “better than expected” outcome.

Purpose: To evaluate and compare patient reported quality of life and satisfaction following metal on metal hip resurfacing and total hip arthroplasty procedures.

Methods: Patients receiving metal-on-metal hip resurfacing and primary total hip arthroplasty were assessed at baseline and followed prospectively with regards to outcomes of quality of life (WOMAC, Oxford-12, SF-12) and satisfaction. Patients receiving resurfacing were matched (1:3) to a cohort of THA on characteristics of age, gender, and comorbidity status. Sample size was selected to evaluate superiority using WOMAC function score with effect size of 0.5, alpha .05, power 80%. Univariate and multivariate analyses were performed.

Results: 222 patients were evaluated with regards to baseline socio-demographic characteristics and quality of life scores(56 resurfacing, 166 THR). Patient cohorts were not different at baseline pre-operatively with regards to age, gender, comorbidity status, WOMAC, Oxford-12, and SF-12 (p> .05). At minimum one year post-op both cohorts reported excellent outcomes. Patients receiving hip resurfacing had superior outcomes with regards to WOMAC function, WOMAC pain, and Oxford-12 hip scores (p< .05). However patients were similar with regards to outcomes of SF-12 mental status and patient-reported satisfaction.

Conclusions: Hip resurfacing and THA patients report excellent outcomes, however, patients receiving hip resurfacing report superior quality of life compared to a matched cohort of THA.

Purpose: To evaluate the effect of outpatient physiotherapy versus a self-adminstered home exercise program on recovery following primary total hip arthroplasty.

Methods: Subjects awaiting primary total hip arthroplasty consented to participate in this prospective randomized clinical trial. Patients were assigned to participate in either an outpatient physiotherapy program or self-administered/self-directed home exercise program following discharge home from hospital. Multiple longitudinal measures were performed to adequately assess recovery over time. Primary outcome for comparison was WOMAC function at 4 months postoperatively, additional outcomes of timed-up-and-go, SF-36, HUI3, FSI. Primary outcome was evaluated using repeated measures analyses and regression models for longitudinal data.

Results: 100 patients were randomized to their respective interventions. The two cohorts were similar with regards to baseline characteristics of age, gender, and pre-op quality of life measures (p> .05). At 4 months post-op both groups demonstrated significant change from baseline function and were similar with regards to recovery and rate of recovery (p> .05).

Conclusions: While all patients demonstrated excellent recovery, patients receiving self-adminstered home exercise program did not demonstrate inferior outcome at the interval(s) assessed. Self-adminstered home exercise program may be an effective alternative rehabilitation program where physiotherapy services are limited or in specific subgroups of patients.

Funding : Educational Grant from the Canadian Orthopaedic Foundation

The two most common surgical approaches used in primary hip arthroplasty are the anterolateral and posterolateral approach. While both approaches have potential advantages and disadvantages in comparison to the other, there are no reports with sufficient power to compare their effect on post-operative function and quality of life. This prospective cohort study evaluates and compares the independent effect of surgical approach on function and quality of life among patients who have received their total hip arthroplasty through one of these techniques. Results suggest that there is no significant difference in function or quality of life among these respective cohorts.

The purpose of this study was to evaluate and compare the effect of anterolateral versus posterolateral approach on function and quality of life following primary total hip arthroplasty.

There is no significant difference in outcome as a result of surgical approach. Significance: This is the first report with sufficient power to evaluate and compare outcomes of these two approaches among high volume hip surgeons. This study suggests that surgeons need not worry that the anterolateral or posterolateral approach may compromise patient function or generic quality of life more-so than the alternative approach.

Univariate and regression analyses demonstrate similar outcomes on WOMAC, Oxford-12, SF-12 and satisfaction among cohorts of patients receiving the anterolateral or posterolateral approach for primary total hip arthroplasty.

A prospective evaluation of function and quality of life outcomes was performed on patients receiving the anterolateral or posterolateral approach for primary hip arthroplasty. All participating surgeons were considered to be high volume arthroplasty surgeons. One hundred and sixty procedures were followed and provided complete outcomes data including WOMAC, Oxford, SF-12, and satisfaction scores. Univariate analyses demonstrated no differences among the two cohorts with regards to baseline variables. Regression analyses were performed for the outcome measures with surgical approach treated as an independent covariate while controlling for other potential confounders. The results suggest that there is no independent effect of surgical approach on patient reported outcomes. This suggests that the surgeon should continue to employ the approach which is the most familiar and most likely to result in consistent results in their clinical environment.

Introduction and Aims: The aim was to study: 1) Patients’ ability to recall their pre-operative function following total hip replacement and how this recall alters with time. 2) Whether validated quality of life (QOL) assessment tools can be administered in the post-operative period to assess pre-operative function.

Method: The null hypothesis was: There is no correlation between functional scores collected pre-operatively and those collected post-operatively. Patients admitted for primary and revision hip arthroplasty between September 2002 and January 2003 were included.

Subjects completed the same questionnaire regarding pre-operative function before surgery, and then three days, six weeks and three months post-operatively. The questionnaire was a combination of the WOMAC, Oxford-12 and SF-12 questionnaires. Pearson’s correlation coefficient was used to evaluate the correlation between the pre- and post-surgery scores, and intra-class correlation coefficient (ICC) was used to assess agreement. Test-retest reliability was evaluated by Kendall’s Tau-b statistic.

Results: One hundred and four patients with a mean age of 61 years were included. There were 57 female patients and 47 males, 79 patients had primary hip replacements and 25 had revisions.

The results showed excellent correlation between pre-operative scores and those from all three postoperative time points. Pearson’s correlation coefficient for the WOMAC score was 0.75, 0.78 and 0.87 at three days, six weeks and three months respectively. The values for the Oxford-12 were 0.83, 0.78 and 0.92 at the same time points, and for the SF-12 they were 0.71, 0.63 and 0.81.

Agreement between pre- and post-operative scores was high. The ICC results for the WOMAC score at the same time points were 0.86, 0.88, and 0.93. For the Oxford-12 they were 0.91, 0.88 and 0.96 and for the SF-12 they were 0.83, 0.77 and 0.9.

Kendall’s Tau-b statistic showed high degrees of reliability for all three measures. The values for the WOMAC score at the three time points were 0.64, 0.61 and 0.72, and the results for the Oxford-12 and SF-12 scores were similarly high.

The effects on the statistics of age, sex, unilateral versus bilateral disease, and primary versus revision surgery were assessed, and no differences were found.

Conclusion: We found a high degree of correlation, agreement and test-retest reliability between QOL scores taken before hip replacement and those taken up to three months afterwards. Patients were able to recall their pre-operative functional status after surgery, and accurate pre-operative data may be collected retrospectively during the early post-operative period.

Introduction and Aims: Functional results following revision total hip arthroplasty (THA) for infection may be inferior to those done for aseptic causes. This cross-sectional study compared the results of patients who had two-stage revision for infection using an articulating spacer device, with those of a control group who had revision for aseptic causes.

Method: Patients admitted between December 1997 and December 2000 for two-stage revision of an infected hip replacement using the PROSTALAC articulating spacer were included. They were compared to patients who had revision of both components for aseptic causes over the same time period. Patients with periprosthetic fractures were excluded.

Pre-operative function was assessed using the Charnley score and bone loss was determined from pre-operative radiographs using the Paprowsky femoral and acetabular classifications. At a minimum two years follow-up, quality of life (QOL) was assessed using the WOMAC, Oxford-12 and SF-12 questionnaires. Patient satisfaction and co-morbidity data were also collected.

Results: There were 44 septic and 105 aseptic revision arthroplasties included in the study. There were no differences between the two groups with respect to co-morbidities, Charnley group, pre-operative pain, function or range of movement or loss of acetabular bone stock. The aseptic group had significantly worse femoral bone stock than the septic group (p=0.008).

All infected patients were treated with the PROSTA-LAC system at the first stage, and 40 patients were reimplanted at the second stage procedure. In four cases, a Girdlestone procedure was performed for persistent infection, although two were re-implanted later.

Re-operations in the septic group were required in six patients for: instability (three), fractured femoral component (one), failure of ingrowth (one), and for recurrence of infection (one). Eight aseptic patients had further revisions for: instability (four), failure of component fixation (three), and for periprosthetic fracture (one).

Although the functional results for both groups were good, the results following revision for sepsis were significantly worse. The mean normalised WOMAC score for infected patients was 66.1, compared to 74.4 for aseptic patients (p=0.028) and the mean Oxford score following infection was 22.4 compared to 18.9 for controls (p=0.007). The satisfaction scores following septic revision were also significantly worse (p=0.02).

Conclusion: Use of an articulated spacer in two-stage revision was successful in eradicating infection, allowing re-implantation in more than 90% of patients, and with good recovery of function. However, the functional results and satisfaction scores were significantly worse than those of a matched control group revised for aseptic causes.

This study was performed to assess the relationship between patients’ pre-operative symptoms and their expectations at the time of revision hip arthroplasty. The WOMAC (Western Ontario and McMaster Osteoarthritis Index) scale for osteoarthritis of the hip and the Short Form 36 (SF-36) general health status scale have both been validated for the assessment of the outcome of hip arthroplasty. We prospectively assessed 60 patients using these scales as well as the “expectation WOMAC” that asked the patients to estimate how they expected to feel 6 months after revision hip replacement. All the questions were completed prior to informed consent, and were scored form 1 to 5 with increasing severity with a Likert scale. The maximum possible scores for pain, stiffness and difficulty with physical activity were therefore 25, 10 and 85 respectively.

The mean preoperative WOMAC score for pain was 13.4 (CI 12.2.-14.6), for stiffness 5.9 (CI 5.6-6.2) and for physical activity 50.9 (CI 47.2-54.6) The mean expectation WOMAC scores for these modalities were 7.4 (CI 6.2-8.6), 3.5 (CI 3.0-4.0) and 28.1 (CI 24.0-32.2.) respectively. Although there was a wide spread of expectations, we were unable to find any significant correlation between the patients’ preoperative pain and The abstracts were prepared by Mr Simon Donell. Correspondence should be addressed to him at the Department of Orthopaedics, Norfolk & Norwich Hospital, Level 4, Centre Block, Colney Lane, Norwich NR4 7UY, United Kingdom. stiffness levels and their expectations for pain and stiffness after revision hip arthroplasty. There was however a statistical association between their preoperative difficulty with physical activity and their expectations for physical activity (r=0.38; p=0.02) There was no significant correlation between the SF-36 scores and the patients’ expectations.

The expectations of patients awaiting revision hip replacements are high, and do not appear to be closely related to their level of pre-operative disability. Even patients with severe symptoms have high expectations that in some cases may be unrealistic. The use of the “expectation WOMAC” may help us to identify such patients, and to improve patient education and satisfaction.

This study constitutes the minimum 5-year follow-up (mean 8.8 years; range 5 – 11.5 years) of a consecutive series of 40 proximal femoral allografts performed for failed total hip arthroplasties using the same technique. Nine of these cases had been two stage reconstructions for the management of infected total hip replacements with bone loss. In all these cases the stem was cemented into both the allograft and the host femur. The host bone was resected in 37 cases, and the greater trochanter reattached with a cable grip in 33 cases and with wire and mesh in 3 cases.

The patients were reviewed by an independent observer. There were 4 early revisions (10%): one for infection, one for non-union of the allograft host junction, and two following revision of a failed acetabular reconstruction. Three further acetabular revisions have since also been performed. Junctional nonunion was seen in 3 cases (8%), two of which were managed successfully with bone grafting and bone grafting and plating respectively. Instability was observed in 6 cases (15%). Trochanteric non-union was seen in 17 cases (42.5%) and trochanteric escape in 10 of these (25%). The mean Harris Hip Score improved from 39 to 79. Severe resorption involving the full thickness of the allograft was seen in 7 cases. This progressed rapidly and silently but has yet to lead to the failure of any of the reconstructions.

Although there was a high early complication rate, the medium term survivorship is excellent, and the clinical outcomes highly satisfactory. The striking observation of severe allograft resorption may be related to a combination of factors. These include the absence of any masking or protective effect that the host bone may have proximally, and surface revascularisation with stress shielding secondary to solid cemented distal fixation. Although continued surveillance is warranted, these results justify the use of structural allografts for selected cases.

This study was performed in order to review the medium term clinical and radiographic outcome of long stem cemented femoral revisions using second generation cementing technique and identify factors predictive of success or failure.

110 long stem revision hip replacements in 106 patients were performed between 1983–1994. There were 51 males and 55 females of an average age of 69 years with a mean follow up of 6.7 years and a minimum follow-up of five years. Clinical assessment included chart review, and assessment by an independent observer using the Harris Hip Score and the Short Form-36. Radiographic review was performed by two independent observers assessing quality of cementing, loosening, trochanteric union, and heterotopic ossification. The cementing technique was evaluated in both the areas of previous fixation, as well as in the new bone below the tip of the previous stem. We reviewed 93 hips in 90 patients, the remainder having either died or been lost to follow-up. 89% of the patients had improved Harris hip score by more than 20 points. Using the Kaplan-Meier method, fifteen-year survivor-ship was calculated at 92.8%. Three (3.2 %) femoral components were revised, six (6.4%) additional femoral components subsided but were not revised; five of these showed poor cementing technique in the virgin zones beyond the area of the previous stem, and two had cortical perforations. Complications included; 7 (7.5%)dislocations, 6 (6.4%) periprosthetic fractures, 2 (2.2%) infections, and 14 (15%) trochanteric non-unions.

Most reports of femoral revision with cement in revision total hip arthroplasty have shown poor results. However, there are no reports that rely solely on long-stem components. This study shows that long stem cemented femoral revisions have an excellent medium term survivorship, good clinical results and high satisfaction rates. The quality of distal cementing is of great importance, as distal radiolucencies and poor cement technique are predictive of failure.

We report 11 patients having revision of total hip arthroplasty using massive structural allografts for failure due to sepsis and associated bone loss. All patients had a two-stage reconstruction and the mean follow-up was 47.8 months (24 to 72). Positive cultures were obtained at the first stage in nine of the 11 patients, with Staphylococcus epidermidis being the most common organism. The other two patients had draining sinuses with negative cultures.

There was no recurrence of infection in any patient. The mean increase in the modified Harris hip score was 45 and all the grafts appeared to have united to host bone. Two patients required additional procedures, but only one was related to the allograft. Complications included an incomplete sciatic nerve palsy and one case of graft resorption. Our results support the use of massive allografts in failed septic hip arthroplasty in which there is associated bone loss.

In 33 dogs we implanted femoral stems made either of carbon composite, some coated with hydroxyapatite, or of titanium alloy with a porous coating. Osseointegration was greater in the hydroxyapatite-coated than in the un-coated stems (p less than 0.001). Push-out tests, at an average of 7.2 months after implantation, showed a six-fold increase in interface shear strength and a twelve-fold increase in shear stiffness in the hydroxyapatite-coated group compared with noncoated implants. The highest shear-strength values were found in the porous-coated titanium alloy stems, around which there was also the most resorptive bone remodelling.