The predictive value and reliability of ultrasound-guided synovial aspiration and biopsies for diagnosing periprosthetic shoulder infections.

INTRODUCTION: Preoperative diagnosis of periprosthetic shoulder infections (PSI) is difficult. Infections are mostly caused by low virulence bacteria and patients do not show typical signs of infection. The aim of this study was to determine the diagnostic value and reliability of ultrasound-guided biopsies for cultures alone and in combination with multiplex polymerase chain reaction (mPCR), serum markers, and/or synovial markers for the preoperative diagnosis of PSI in patients undergoing revision shoulder surgery. MATERIALS AND METHODS: A prospective explorative diagnostic cohort study was performed including 55 patients undergoing revision shoulder replacement surgery. A shoulder puncture was performed preoperatively before incision to collect synovial fluid for mPCR analysis and for measurement of interleukin-6, calprotectin, white blood cell count (WBC), and polymorphonuclear cells. Also prior to revision surgery, six ultrasound-guided synovial tissue biopsies were collected for culture and two for mPCR analysis. A blood sample was obtained to determine serum C-reactive protein, WBC, and erythrocyte sedimentation rate. Six routine care tissue biopsies were taken during revision surgery and served as reference standard. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV; the primary outcome measure), and accuracy were calculated for ultrasound-guided biopsies, blood and synovial markers, mPCR, and combinations thereof. RESULTS: Routine tissue cultures were positive for infection in 24 patients. Cultures from ultrasound-guided biopsies diagnosed infection in 7 of these patients, yielding a sensitivity, specificity, PPV, NPV, and accuracy of 29.2%, 93.5%, 77.8%, 63.0%, and 65.6%, respectively. The best diagnostic value was found for the combination of ultrasound-guided biopsies for culture, synovial WBC, and calprotectin with a sensitivity of 69.2%, specificity of 80.0%, PPV of 69.2%, and NPV of 80.0%. CONCLUSION: Ultrasound-guided biopsies for cultures alone and in combination with mPCR, and/or blood and/or synovial markers are not reliable enough to use in clinical practice for the preoperative diagnosis of PSI. LEVEL OF EVIDENCE: Diagnostic study level II.

Survival of cemented short Exeter femoral components in primary total hip arthroplasty.

Aims: The aim of this study was to report the long-term follow-up of cemented short Exeter femoral components when used in primary total hip arthroplasty (THA). Methods: We included all primary 394 THAs with a cemented short Exeter femoral component (≤ 125 mm) used in our tertiary referral centre between October 1993 and December 2021. A total of 83 patients (21%) were male. The median age of the patients at the time of surgery was 42 years (interquartile range (IQR) 30 to 55). The main indication for THA was a childhood hip disease (202; 51%). The median follow-up was 6.7 years (IQR 3.1 to 11.0). Kaplan-Meier survival analyses were performed to determine the rates of survival with femoral revision for any indication, for septic loosening, for fracture of the femoral component and for aseptic loosening as endpoints. The indications for revision were evaluated. Fractures of the femoral component were described in detail. Results: The 20-year rate of survival was 85.4% (95% confidence interval (CI) 73.9 to 92.0) with revision for any indication, 96.2% (95% CI 90.5 to 98.5) with revision for septic loosening and 92.7% (95% CI 78.5 to 97.6) with revision for fracture of the femoral component. No femoral components were revised for aseptic loosening. There were 21 revisions of the femoral component; most (seven) as part of a two-stage management of infection. Fracture of the femoral component occurred in four THAs (1.0%) at 6.6, 11.6, 16.5, and 18.2 years of follow-up, respectively. Three of these were transverse fractures and occurred at the level of the lesser trochanter. In one THA, there was a fracture of the neck of the component. Conclusion: THAs using cemented short Exeter femoral components showed acceptable rates of survival of the femoral component at long-term follow-up, in this young cohort of patients. Although fracture is a rare complication of these components, surgeons should be aware of their incidence and possible risk factors.

A mapping review on preoperative prognostic factors and outcome measures of revision total knee arthroplasty.

To map literature on prognostic factors related to outcomes of revision total knee arthroplasty (rTKA), to identify extensively studied factors and to guide future research into what domains need further exploration. We performed a systematic literature search in MEDLINE, Embase, and Web of Science. The search string included multiple synonyms of the following keywords: "revision TKA", "outcome" and "prognostic factor". We searched for studies assessing the association between at least one prognostic factor and at least one outcome measure after rTKA surgery. Data on sample size, study design, prognostic factors, outcomes, and the direction of the association was extracted and included in an evidence map. After screening of 5,660 articles, we included 166 studies reporting prognostic factors for outcomes after rTKA, with a median sample size of 319 patients (30 to 303,867). Overall, 50% of the studies reported prospectively collected data, and 61% of the studies were performed in a single centre. In some studies, multiple associations were reported; 180 different prognostic factors were reported in these studies. The three most frequently studied prognostic factors were reason for revision (213 times), sex (125 times), and BMI (117 times). Studies focusing on functional scores and patient-reported outcome measures as prognostic factor for the outcome after surgery were limited (n = 42). The studies reported 154 different outcomes. The most commonly reported outcomes after rTKA were: re-revision (155 times), readmission (88 times), and reinfection (85 times). Only five studies included costs as outcome. Outcomes and prognostic factors that are routinely registered as part of clinical practice (e.g. BMI, sex, complications) or in (inter)national registries are studied frequently. Studies on prognostic factors, such as functional and sociodemographic status, and outcomes as healthcare costs, cognitive and mental function, and psychosocial impact are scarce, while they have been shown to be important for patients with osteoarthritis.

Thirty years of experience with instrumented femoral impaction bone grafting and a cemented polished Exeter stem : a prospective cohort study of 208 revision arthroplasties performed between 1991 and 2007.

AIMS: The aim of this study is to report the long-term outcomes of instrumented femoral revisions with impaction allograft bone grafting (IBG) using the X-change femoral revision system at 30 years after introduction of the technique. METHODS: We updated the outcomes of our previous study, based on 208 consecutive revisions using IBG and the X-change femoral revision system in combination with a cemented polished stem, performed in our tertiary care institute between 1991 and 2007. Kaplan-Meier survival analyses were used to determine the survival rate of the revisions with endpoint revision for any reason and aseptic loosening. Secondary outcomes were radiological loosening and patient-reported outcome measures. RESULTS: Mean age at revision total hip arthroplasty (THA) was 64.9 years (30 to 86). The most prevalent diagnosis for the femoral revision was aseptic loosening. At review in May 2021, 81 patients (85 hips) were still alive and 118 patients (120 hips; 58%) had died. Three patients (3 hips; 1%) were lost to follow-up at 11, 15, and 16 years after surgery, respectively. Data of all deceased and lost patients were included until final follow-up. The mean follow-up was 13.4 years (0 to 28). During the follow-up, 22 re-revisions were performed. The most common reason for re-revision was infection (n = 12; 54%). The survival with endpoint re-revision for any reason was 86% (95% confidence interval (CI) 79 to 91) at 20 years and 74% (95% CI 43 to 89) at 25 years after surgery. The survival for endpoint re-revision for aseptic loosening was 97% (95% CI 91 to 99) after both 20 and 25 years. CONCLUSION: We conclude that femoral IBG is a valuable technique that can reconstitute femoral bone loss in the long term. After 25 years of follow-up, few re-revisions for aseptic loosening were required. Also, the overall revision rate is very acceptable at a long follow-up. This technique is especially attractive for younger patients facing femoral revisions with extensive bone loss.Cite this article: Bone Joint J 2022;104-B(9):1039-1046.

The risk of revision after total hip arthroplasty in young patients depends on surgical approach, femoral head size and bearing type; an analysis of 19,682 operations in the Dutch arthroplasty register.

BACKGROUND: Total hip arthroplasty (THA) is used increasingly in younger patients. There is little knowledge about the effect of THA characteristics on risk of revision, especially in young patients. Therefore, we studied the influence of both patient-related and surgical factors on the risk of revision using data from the Dutch Arthroplasty Registry (LROI). METHODS: All patients younger than 55 years with a primary THA implanted in the Netherlands between 2007 and 2017 were selected (n = 19,682). The covariates age, sex, primary diagnosis, ASA-classification, surgical approach, fixation method, bearing type, head size and year of surgery were entered into Cox proportional hazards models to calculate hazard ratios for the risk of revision. RESULTS: The overall 5-year survival of primary THA was 95.3% (95% CI, 94.9-95.6). Use of the anterior approach resulted in a lower risk of revision than the use of the posterolateral approach (HR: 0.66, 95% CI: 0.47-0.92). THAs with a head diameter ≥ 38 mm had a higher risk of revision (HR: 1.90, 95% CI: 1.33-2.72) than THAs with 32 mm heads. Use of MoM bearings resulted in an increased risk when compared to C-PE (HR: 1.76, 95% CI: 1.27-2.43). CONCLUSION: The risk of revision in patients younger than 55 years depends on surgical approach, head size and bearing type. The anterior approach resulted in a decreased risk of revision, whereas use of ≥38 mm heads and MoM bearings resulted in an increased risk of revision for any reason.

Lateral rim mesh in primary total hip arthroplasty: a suitable option to reconstruct segmental acetabular bone defects in young patients?

AIMS: The aim of this study was to analyze the effect of a lateral rim mesh on the survival of primary total hip arthroplasty (THA) in young patients, aged 50 years or younger. PATIENTS AND METHODS: We compared a study group of 235 patients (257 hips) who received a primary THA with the use of impaction bone grafting (IBG) with an additional lateral rim mesh with a group of 306 patients (343 hips) who received IBG in the absence of a lateral rim mesh during the same period from 1988 to 2015. In the mesh group, there were 74 male and 183 female patients, with a mean age of 35 years (13 to 50). In the no-mesh group, there were 173 male and 170 female patients, with a mean age of 38 years (12.6 to 50). Cox regression analyses were performed to study the effect of a lateral rim mesh on acetabular component survival. Kaplan-Meier analyses with 95% confidence intervals (CIs) were performed to estimate the survival of the acetabular implant. RESULTS: The hazard ratio for the use of lateral rim mesh, adjusted for potential confounders, for acetabular revision for any reason was 0.50 (95% CI 0.13 to 1.93; p = 0.31) and for acetabular revision for aseptic loosening was 0.29 (95% CI 0.020 to 4.04; p = 0.35). The Kaplan-Meier analysis showed a ten-year survival for aseptic loosening of the acetabular of 98% (95% CI 95 to 100, n = 65 at risk) in the mesh group and 94% (89 to 98, n = 76 at risk) in the no-mesh group. The 15-year survival for aseptic acetabular loosening was 90% (81 to 100, n = 35 at risk) in the mesh group and 85% (77 to 94, n = 45 at risk) in the no-mesh group (p = 0.23). CONCLUSION: This study shows that the use of a lateral rim mesh in primary THA in young patients is not associated with a higher risk of revision of the acetabular component. Therefore, we consider a lateral rim mesh combined with IBG to be effective in reconstructing segmental acetabular defects in primary THA.

Results of the cemented Exeter femoral component in patients under the age of 40 : an update at ten to 20 years' follow-up.

AIMS: We carried out a further study of the long-term results of the cemented Exeter femoral component in patients under the age of 40 with a mean follow-up of 13.6 years (10 to 20). PATIENTS AND METHODS: We reviewed our original cohort of 104 cemented Exeter stems in 78 consecutive patients with a mean age of 31 years (16 to 39). Only one patient was lost to radiological follow-up. RESULTS: A total of six patients (eight hips) had died for reasons unrelated to their surgery. There had been one further periprosthetic fracture from a fall and one fractured femoral stem. No revisions for aseptic loosening were undertaken during the whole study period. Overall, 11 hips had progressive radiolucent lines in one or more zones. The Kaplan Meier survival percentages at ten and 17 years were 97.1% (95% confidence interval (CI) 91.3 to 99.1) and 92.1% (95% CI 74.1 to 97.8) with revision for any reason as the endpoint, and 100% at both ten and 17 years with aseptic loosening (95% CI 83.8 to 100) as the endpoint. No additional hips were classified as radiologically loose. CONCLUSION: The Exeter femoral component continues to function satisfactorily in young patients for up to 17 years after surgery. Cite this article: Bone Joint J 2017;99-B:192-8.

Experimental Measurement of the Static Coefficient of Friction at the Ti-Ti Taper Connection in Total Hip Arthroplasty.

The modular taper junction in total hip replacements has been implicated as a possible source of wear. The finite-element (FE) method can be used to study the wear potential at the taper junction. For such simulations it is important to implement representative contact parameters, in order to achieve accurate results. One of the main parameters in FE simulations is the coefficient of friction. However, in current literature, there is quite a wide spread in coefficient of friction values (0.15 - 0.8), which has a significant effect on the outcome of the FE simulations. Therefore, to obtain more accurate results, one should use a coefficient of friction that is determined for the specific material couple being analyzed. In this study, the static coefficient of friction was determined for two types of titanium-on-titanium stem-adaptor couples, using actual cut-outs of the final implants, to ensure that the coefficient of friction was determined consistently for the actual implant material and surface finish characteristics. Two types of tapers were examined, Biomet type-1 and 12/14, where type-1 has a polished surface finish and the 12/14 is a microgrooved system. We found static coefficients of friction of 0.19 and 0.29 for the 12/14 and type-1 stem-adaptor couples, respectively.

Acetabular revision with impaction bone grafting and a cemented polyethylene acetabular component: comparison of the Kaplan-Meier analysis to the competing risk analysis in 62 revisions with 25 to 30 years follow-up.

We present the results of 62 consecutive acetabular revisions using impaction bone grafting and a cemented polyethylene acetabular component in 58 patients (13 men and 45 women) after a mean follow-up of 27 years (25 to 30). All patients were prospectively followed. The mean age at revision was 59.2 years (23 to 82). We performed Kaplan-Meier (KM) analysis and also a Competing Risk (CR) analysis because with long-term follow-up, the presence of a competing event (i.e. death) prevents the occurrence of the endpoint of re-revision. A total of 48 patients (52 hips) had died or had been re-revised at final review in March 2011. None of the deaths were related to the surgery. The mean Harris hip score of the ten surviving hips in ten patients was 76 points (45 to 99). The KM survivorship at 25 years for the endpoint 're-revision for any reason' was 58.0% (95% confidence interval (CI) 38 to 73) and for 're-revision for aseptic loosening' 72.1% (95% CI 51 to 85). With the CR analysis we calculated the KM analysis overestimates the failure rate with respectively 74% and 93% for these endpoints. The current study shows that acetabular impaction bone grafting revisions provide good clinical results at over 25 years.

The outcome of femoral component revision arthroplasty with impaction allograft bone grafting and a cemented polished Exeter stem: A prospective cohort study of 208 revision arthroplasties with a mean follow-up of ten years.

We report the clinical and radiographic outcomes of 208 consecutive femoral revision arthroplasties performed in 202 patients (119 women, 83 men) between March 1991 and December 2007 using the X-change Femoral Revision System, fresh-frozen morcellised allograft and a cemented polished Exeter stem. All patients were followed prospectively. The mean age of the patients at revision was 65 years (30 to 86). At final review in December 2013 a total of 130 patients with 135 reconstructions (64.9%) were alive and had a non re-revised femoral component after a mean follow-up of 10.6 years (4.7 to 20.9). One patient was lost to follow-up at six years, and their data were included up to this point. Re-operation for any reason was performed in 33 hips (15.9%), in 13 of which the femoral component was re-revised (6.3%). The mean pre-operative Harris hip score was 52 (19 to 95) (n = 73) and improved to 80 (22 to 100) (n = 161) by the last follow-up. Kaplan-Meier survival with femoral re-revision for any reason as the endpoint was 94.9% (95% confidence intervals (CI) 90.2 to 97.4) at ten years; with femoral re-revision for aseptic loosening as the endpoint it was 99.4% (95% CI 95.7 to 99.9); with femoral re-operation for any reason as the endpoint it was 84.5% (95% CI 78.3 to 89.1); and with subsidence ≥ 5 mm it was 87.3% (95% CI 80.5 to 91.8). Femoral revision with the use of impaction allograft bone grafting and a cemented polished stem results in a satisfying survival rate at a mean of ten years' follow-up.

The use of a long stem cemented femoral component in revision total hip replacement: a follow-up study of five to 16 years.

In this retrospective study, we investigated the results of revision total hip replacement (THR) using a cemented long-stemmed Exeter femoral component, with a minimum length of 205 mm in patients with extensive femoral bone defects. The study included 37 consecutive patients with a mean age of 76 years (39 to 93) and a mean follow-up of nine years (5 to 16). A total of 26 patients (70%) had a pre-operative Endo-Klinik score of 3 or 4. Impaction bone grafting was used in 24 patients (65%). At the time of evaluation, 22 patients (59%) were still alive and were evaluated clinically and radiologically. A total of 14 patients died during follow-up and their data were included until the time of their death. One reconstruction failed after five years and five months owing to recurrent dislocation: the hip was converted to an excision arthroplasty. Intra-operative fractures or fissures were encountered in nine patients (24%), but none occurred during impaction of the bone graft. Post-operative peri-prosthetic fractures occurred in two patients (5%); both were treated with plate fixation. At nine years, survival with the endpoint of all-cause re-revision was 96.3% (95% CI 76.4 to 99.5); including re-operations for any reason, it was 80.7% (95% CI 56.3 to 92.3%). There were no re-revisions for aseptic loosening. The survival of long stem cemented femoral components following revision THR is satisfactory in a fragile population with extensive femoral defects.

Femoral revision with impaction bone grafting and a cemented polished tapered stem.

OBJECTIVE: Biological repair of femoral bone loss using bone impaction grafting. Reconstruction of the centre of rotation of the hip using a cemented stem, the size and offset of which are at the discretion of the surgeon. INDICATIONS: Femoral implant loosening with bone loss. CONTRAINDICATIONS: Infection, neurological disorders, noncompliant patient. SURGICAL TECHNIQUE: Extraction of the loose femoral implant, cortical reconstruction using meshes if required, impaction bone grafting with special instruments, cement fixation of a polished tapered stem. POSTOPERATIVE MANAGEMENT: Individualized period of bed rest and limited weight bearing. RESULTS: Impaction bone grafting and a cemented polished stem were used to perform 33 femoral reconstructions. After a mean follow-up of 15 years, no femoral reconstruction had to be revised. One unrecognized intraoperative fracture healed after nonsurgical treatment, three postoperative femoral fractures healed after plate fixation with the stem left in situ. The average Harris Hip Score improved from 49 prior to surgery to 85 points thereafter. Kaplan-Meier analysis with femoral revision for any reason as the end point showed a survival rate of 100 %.

Clinical and radiological outcome of the cemented Contemporary acetabular component in patients < 50 years of age.

Despite the worldwide usage of the cemented Contemporary acetabular component (Stryker), no published data are available regarding its use in patients aged < 50 years. We undertook a mid- to long-term follow-up study, including all consecutive patients aged < 50 years who underwent a primary total hip replacement using the Contemporary acetabular component with the Exeter cemented stem between January 1999 and January 2006. There were 152 hips in 126 patients, 61 men and 65 women, mean age at surgery 37.6 years (16 to 49 yrs). One patient was lost to follow-up. Mean clinical follow-up of all implants was 7.6 years (0.9 to 12.0). All clinical questionnaire scores, including Harris hip score, Oxford hip score and several visual analogue scales, were found to have improved. The eight year survivorship of all acetabular components for the endpoints revision for any reason or revision for aseptic loosening was 94.4% (95% confidence interval (CI) 89.2 to 97.2) and 96.4% (95% CI 91.6 to 98.5), respectively. Radiological follow-up was complete for 146 implants. The eight year survival for the endpoint radiological loosening was 93.1% (95% CI 86.2 to 96.6). Three surviving implants were considered radiologically loose but were asymptomatic. The presence of acetabular osteolysis (n = 17, 11.8%) and radiolucent lines (n = 20, 13.9%) in the 144 surviving cups indicates a need for continued observation in the second decade of follow-up in order to observe their influence on long-term survival. The clinical and radiological data resulting in a ten-year survival rate > 90% in young patients support the use of the Contemporary acetabular component in this specific patient group.

Comparison of contamination of femoral heads and pre-processed bone chips during hip revision arthroplasty.

With bone impaction grafting, cancellous bone chips made from allograft femoral heads are impacted in a bone defect, which introduces an additional source of infection. The potential benefit of the use of pre-processed bone chips was investigated by comparing the bacterial contamination of bone chips prepared intraoperatively with the bacterial contamination of pre-processed bone chips at different stages in the surgical procedure. To investigate baseline contamination of the bone grafts, specimens were collected during 88 procedures before actual use or preparation of the bone chips: in 44 procedures intraoperatively prepared chips were used (Group A) and in the other 44 procedures pre-processed bone chips were used (Group B). In 64 of these procedures (32 using locally prepared bone chips and 32 using pre-processed bone chips) specimens were also collected later in the procedure to investigate contamination after use and preparation of the bone chips. In total, 8 procedures had one or more positive specimen(s) (12.5 %). Contamination rates were not significantly different between bone chips prepared at the operating theatre and pre-processed bone chips. In conclusion, there was no difference in bacterial contamination between bone chips prepared from whole femoral heads in the operating room and pre-processed bone chips, and therefore, both types of bone allografts are comparable with respect to risk of infection.

Revision surgery is overestimated in hip replacement.

OBJECTIVES: The Kaplan-Meier estimation is widely used in orthopedics to calculate the probability of revision surgery. Using data from a long-term follow-up study, we aimed to assess the amount of bias introduced by the Kaplan-Meier estimator in a competing risk setting. METHODS: We describe both the Kaplan-Meier estimator and the competing risk model, and explain why the competing risk model is a more appropriate approach to estimate the probability of revision surgery when patients die in a hip revision surgery cohort. In our study, a total of 62 acetabular revisions were performed. After a mean of 25 years, no patients were lost to follow-up, 13 patients had undergone revision surgery and 33 patients died of causes unrelated to their hip. RESULTS: The Kaplan-Meier estimator overestimates the probability of revision surgery in our example by 3%, 11%, 28%, 32% and 60% at five, ten, 15, 20 and 25 years, respectively. As the cumulative incidence of the competing event increases over time, as does the amount of bias. CONCLUSIONS: Ignoring competing risks leads to biased estimations of the probability of revision surgery. In order to guide choosing the appropriate statistical analysis in future clinical studies, we propose a flowchart.

Impactability and time-dependent mechanical properties of porous titanium particles for application in impaction grafting.

AIMS: Impaction grafting with bone particles is a successful technique to restore bone stock loss during hip revision surgery. Allograft shortage is expected within the near future. This study investigates the feasibility of porous titanium particles (TiP) to replace bone particles (BoP) and to compare mechanical properties of TiP and a commercially available porous ceramic bone graft extender (CeP). Impactability and time-dependent mechanical properties (stability and stiffness during physiologic loading (0.1-2.5 MPa)) were assessed by standardized impaction and a confined compression test. Loaded samples were used for particle release analysis. FINDINGS: TiP were more impactable than BoP and created a stable, highly entangled macroporous construct. CeP were crushed during impaction, resulting in non-cohesive specimens of small ceramic particles. TiP showed very little deformation at the end of physiological loading. Impacted TiP were stiffer than BoP but more elastic than CeP. TiP generated a low volume of microparticles (0.2% of original TiP weight) with a bimodal size distribution (diameter range, 7-2000 microm). CONCLUSION: TiP are impactable and create a stable, elastic and highly entangled, macroporous layer. Further in-vitro testing and biological studies are warranted to verify whether the promising results are maintained with THA reconstructions.

Acetabular revision with impacted morsellised cancellous bone grafting and a cemented acetabular component: a 20- to 25-year follow-up.

We present an update of the clinical and radiological results of 62 consecutive acetabular revisions using impacted morsellised cancellous bone grafts and a cemented acetabular component in 58 patients, at a mean follow-up of 22.2 years (20 to 25). The Kaplan-Meier survivorship for the acetabular component with revision for any reason as the endpoint was 75% at 20 years (95% confidence interval (CI) 62 to 88) when 16 hips were at risk. Excluding two revisions for septic loosening at three and six years, the survivorship at 20 years was 79% (95% CI 67 to 93). With further exclusions of one revision of a well-fixed acetabular component after 12 years during a femoral revision and two after 17 years for wear of the acetabular component, the survivorship for aseptic loosening was 87% at 20 years (95% CI 76 to 97). At the final review 14 of the 16 surviving hips had radiographs available. There was one additional case of radiological loosening and four acetabular reconstructions showed progressive radiolucent lines in one or two zones. Acetabular revision using impacted large morsellised bone chips (0.5 cm to 1 cm in diameter) and a cemented acetabular component remains a reliable technique for reconstruction, even when assessed at more than 20 years after surgery.

The medium-term results of the cemented Exeter femoral component in patients under 40 years of age.

We evaluated the outcome of 104 consecutive primary cemented Exeter femoral components in 78 patients (34 men, 44 women) under the age of 40 years who underwent total hip replacement between October 1993 and May 2004. The mean age at operation was 31 years (16 to 39). No hip was lost to follow-up, but three patients (four hips) died. None of the deaths were related to the surgery. At a mean follow-up of 6.2 years (2 to 13), three femoral components had been revised for septic loosening. Using Kaplan-Meier survival analysis, the seven-year survival of the component with revision for any reason as the endpoint was 95.8% (95% confidence interval 86.67 to 98.7). The seven-year survival with aseptic femoral loosening as the endpoint was 100% (95% confidence interval 100). The cemented Exeter femoral component in patients under the age of 40 shows promising medium-term results. As it is available in a wide range of sizes and offsets, we could address all types of anatomical variation in this series without the need for custom-made components.

High incidence of squeaking in THAs with alumina ceramic-on-ceramic bearings.

UNLABELLED: Ceramic-on-ceramic bearings in THA are a popular alternative to overcome wear concerns in traditional metal-polyethylene bearings. However, squeaking is a potentially worrisome phenomenon in ceramic-on-ceramic THAs which we observed in some of our patients. We reviewed all 42 patients who underwent 43 ceramic-on-ceramic noncemented THAs during the time of the study. Squeaking, defined as a reproducible sound of squeaking, clicking, or grating, occurred in nine of 43 implants (20.9%). Standard radiographs were normal. We used CT imaging to determine cup anteversion and inclination angles, comparing the squeaking hips with those of a randomly selected control group, but found no differences. We then hypothesized specific design features (stem size, cup size, head size, and neck length of the head) would be risk factors for squeaking. We found a difference in neck length between squeaking and nonsqueaking implants. A neck length of -4 mm or shorter resulted in a relative risk of 5.56 (95% confidence interval, 1.14-27.01) for squeaking. We found a high incidence of squeaking in our population, and we believe this phenomenon is an underreported side effect of these types of bearings. A short neck length of the femoral implant was a risk factor for squeaking in ceramic-on-ceramic THA. LEVEL OF EVIDENCE: Level III, therapeutic study.