The final follow-up plain radiograph is sufficient for clinical evaluation of polyethylene wear in total hip arthroplasty: A study of validity and reliability

Background and purpose

Radiostereometric analysis (RSA) is a highly accurate tool for assessment of polyethylene (PE) wear in total hip arthroplasty (THA); however, PE wear measurements in clinical studies are often limited to plain radiographs. We evaluated the agreement between PE wear measured with PolyWare software, which uses plain radiographs, and by model-based RSA, which uses stereo radiographs.

Methods

Measurements of PE wear postoperatively and at final follow-up (after mean 6 years) on plain radiographs of 12 patients after cementless THA were evaluated with PolyWare software and the results were compared with those from RSA as the gold standard (Model-based RSA using elementary geometrical shape models; EGS-RSA). With PolyWare, we either used the final radiographic follow-up (PW1) only or both the postoperative follow-up and the final follow-up (PW2).

Results

The 2D mean wear measured (in mm) was 0.80, 1.07, and 0.60 for the PW2, PW1, and RSA method. 2D intra-method repeatability was similar for PW1 and RSA with limits of agreement (LOAs, in mm) of ± 0.22, and ± 0.23, respectively. 2D inter-method concurrent validity was best between PW1 and EGS-RSA with LOAs of ± 0.55. For 2D linear wear measurements, the PW1 method had a clinical repeatability similar to that of RSA.

Interpretation

PW1 is sufficient for retrospective determination of 2D wear from medium-term wear measurements above 0.5 mm, It alleviates the need for baseline plain radiographs, has a clinical precision similar to that of RSA, and is easy and inexpensive to use.Wear of polyethylene (PE) components is widely regarded as the main factor limiting longevity of total hip arthroplasty (THA) (Cooper et al. 1992). Clinical studies have shown that periprosthetic osteolysis and aseptic loosening is strongly related to wear rates of above 0.2 mm/year (Sochart 1999, Dowd et al. 2000).Radiostereometric analysis (RSA) is the most accurate tool for in vivo assessment of PE wear (Kärrholm et al. 1997, von Schewelov et al. 2004, Bragdon et al. 2006), and it is regarded as the gold standard (Ilchmann et al. 1995). However, many radiographic in vivo studies of PE wear in THA are restricted to measurements on plain radiographs because the RSA set-up is expensive and not widely available. Measurement of PE wear on plain radiographs is often limited to 2D analysis because poor quality of cross-table lateral radiographs is a common problem (Sychterz et al. 1999b, 2001). Although PE wear is known to occur multidirectionally (Yamaguchi et al. 1997, Akisue et al. 1999), the bulk of the wear is detectable on the anterior-posterior radiographs alone (Sychterz et al. 1997, Hui et al. 2003, Martell et al. 2003). Based on the availability of radiographs and investigator preferences, some authors favor analysis of serial radiographs (Sychterz et al. 1997, Kim et al. 2001, Hernigou and Bahrami 2003) to describe the pattern of wear and the steady-state wear (Sychterz et al. 1999a, Bragdon et al. 2006), whereas others use 2 radiographic follow-ups (postoperative and latest) (Kraay et al. 2006), or only the latest radiographic follow-up with the assumption of zero wear at baseline (Norton et al. 2002)Little is known about the conformity between PE wear results measured with RSA and computerized methods using plain radiographs (Ilchmann et al. 1995, von Schewelov et al. 2004, Bragdon et al. 2006). Our group has questioned the conformity of 2D PE wear measurements based on serial, 2, or 1 radiographic follow-up (Stilling et al. 2009b). We determined that there was a statistically significant difference between all approaches, but we were unable to determine which strategy best reflected the true extent of wear (Stilling et al. 2009b). In addition, we recently showed that model-based RSA is an accurate tool for measurement of PE wear in good agreement with the true wear (Stilling 2009).We have now studied the intra-method repeatability and concurrent validity between 2 methods (PolyWare and EGS-RSA) for measurement of PE wear in THA, in a group of patients with an average follow-up of 6 years. We wanted to determine (1) whether there would be a difference in repeatability between the methods, (2) whether there would be a difference in wear measured using 1 or 2 radiographic follow-ups with the PolyWare method, and (3) whether either of the 2 PolyWare measurement strategies (1 or 2 radiographic follow-ups) would give results similar to the wear measured by RSA (concurrent validity).     

Use of perioperative cardiac medical therapy among patients undergoing coronary artery bypass graft surgery

BACKGROUND: Previous studies have demonstrated that cardiac medical therapy is associated with improved clinical outcomes in noncardiac surgery. However, the use of these agents among patients undergoing coronary artery bypass graft (CABG) remains poorly understood. METHODS: We described the in-hospital medication use among 2,389 consecutive patients who underwent CABG at three North American hospitals. Demographic, clinical, and medication use information was extracted from resource and cost accounting systems at each hospital. We examined use of aspirin, angiotensin-converting-enzyme (ACE) inhibitors, beta blockers, and statins during the following seven in-hospital periods: admission, presurgery, the day before surgery, the day of surgery, the day after surgery, postsurgery, and discharge. RESULTS: Medication use throughout hospitalization was low among patients undergoing CABG. Use of ACE inhibitors and statins on the day of surgery was <10%, while aspirin and beta blocker use on the day of surgery was 43.0% and 42.9%, respectively. The use of cardiac medical therapy at hospital discharge was also low (ACE inhibitors: 23.0%; aspirin: 74.9%; beta blockers: 58.9%; and statins: 28.2%). The use of cardiac medical therapy at discharge appeared to increase over time. CONCLUSION: In-hospital cardiac medical therapies are underused among patients undergoing CABG. This is particularly true at discharge, where the benefits of these agents for secondary prevention are well established.     

Decisional regret after robotic-assisted laparoscopic prostatectomy is higher in African American men

ObjectivesLongitudinal studies report racial disparities in prostate cancer (PCa) including greater incidence, more aggressive tumor biology, and increased cancer-specific mortality in African American (AA) men. Regret concerning primary treatment selection is underevaluated in patients with PCa. We investigated the relationships between clinicopathologic variables across racial and socioeconomic lines following robotic-assisted laparoscopic prostatectomy.Materials and methodsWe assessed treatment decisional regret using a validated questionnaire in a total of 484 white and 72 AA patients with PCa who were followed up for a median of 16.6 months post–robotic-assisted laparoscopic prostatectomy. Socioeconomic status (SES) information was aggregated from 2010 US census zip code data. Perioperative clinicopathologic characteristics and functional outcomes were compared between groups. Univariate and multivariate regression analyses were used to evaluate the influence of race, aggregate SES, and other clinical and demographic characteristics on decisional regret.ResultsThe majority (87.7%) of the population was not regretful of their decision to undergo treatment. However, a greater proportion of AA vs. white patients were regretful (20.6% vs. 11.2%, respectively; P = 0.03). AA and white men were similar on all functional, clinical, and pathologic features with the exception of younger age among AA men (56 vs. 60 y, respectively; P<0.001). Although there were significant differences in SES by race (P<0.001), regret did not differ by SES (β =?1.53; P = 0.15). Race, postoperative sexual dysfunction, pad usage, and length of hospital stay, however, were significantly associated with decisional regret.ConclusionsAA men were more regretful than white men, after adjusting for clinicopathologic characteristics and postoperative functional outcomes.     

The development of new density gradient media for purifying human islets and islet-quality assessments

Successful islet transplantation is dependent on the quality and quantity of islets infused. Islets are purified on density gradients, but procedures currently used have limited capacity for pancreatic digests, islet yield, and viability. We aimed to improve islet purification with a modified gradient medium. Biocoll was diluted in University of Wisconsin solution to create linear density gradients of 1.065 to 1.095 g/mL. Properties of islets purified from 22 human pancreas digests with modified medium were compared with 15 preparations using standard medium. The modification increased the capacity of gradients for pancreatic digests from 20 to 60 mL, islet yield increased from 218,000 to 435,318 per isolation, and viability increased from 65.4% to 92.1%. Islet fractions contained greater than 95% of recovered insulin. Islets showed good physiologic responses to secretagogues and restored normoglycemia in streptozotocin-induced diabetic severe combined immunodeficiency disease mice. The new medium enhances yield, purity, and viability of human islet preparations for clinical islet transplantation.     

Why are patients still in hospital after fast-track,unilateral unicompartmental knee arthroplasty

Background and purpose — Previous studies have investigated risk factors related to prolonged length of stay following total knee arthroplasty (TKA), but little is known about specific factors resulting in continued hospitalization within the 1st postoperative days after unicompartmental knee arthroplasty (UKA). We investigated what specific factors prevent patients from being discharged on the day of surgery (DOS) and the first postoperative day (POD-1) following primary UKA in a fast-track setting.Patients and methods — We prospectively collected data on 100 consecutive and unselected medial UKA patients operated from December 2017 to May 2019. All patients were operated in a standardized fast-track setup with functional discharge criteria continuously evaluated from DOS and until discharge.Results — Median length of stay for the entire cohort was 1 day. 22% and 78% of all patients were discharged on DOS and POD-1, respectively. Lack of mobilization and pain separately delayed discharge in respectively 78% and 24% of patients on DOS. The main reasons for lack of mobilization were motor blockade (37%) and logistical factors (26%). For patients placed 1st or 2nd on the operating list, we estimate that the same-day discharge rate would increase to 55% and 40% respectively, assuming that pain and mobilization were successfully managed.Interpretation — One-fifth of unselected UKA patients operated in a standardized fast-track setup were discharged on DOS. Pain and lack of mobilization were the major reasons for continued hospitalization within the initial postoperative 24–48 hours. Strategies aimed at decreasing length of stay after UKA should strive to improve analgesia and postoperative mobilization.

The number of unicompartmental knee arthroplasties (UKAs) performed in patients suffering from osteoarthritis has steadily increased. UKA has the potential benefit of not only improving patient-reported outcomes, but also to reduce morbidity, complications, and cost (Liddle et al. 2014, Beard et al. 2019). In the United Kingdom, 9% of all primary knee arthroplasties performed in 2018 were UKAs while this number is as high as 20% in Denmark (Danish Knee Arthroplasty Register 2019, National Joint Registry for England 2019).UKA is effective and safe when performed in a fast-track setting and outpatient UKA in selected patients has been shown to be feasible and safe (Munk et al. 2012, Cross and Berger 2014, Bovonratwet et al. 2017, Kort et al. 2017). However, the number of patients actually being discharged on DOS that were scheduled for outpatient surgery differs between studies and ranges from 37% to 100% (Gondusky et al. 2014, Bradley et al. 2017, Jenkins et al. 2019, Rytter et al. 2019).Studies have shown an association between increased length of stay (LOS) and an increase in both complication and readmission rates (Otero et al. 2016). In order to reduce LOS and increase patient satisfaction, a focus on successfully managing well-defined discharge criteria in a multimodal approach is imperative (Husted et al. 2008, Cross and Berger 2014). In addition, decreased LOS and outpatient procedures are associated with financial benefits, which have further fueled interest in decreasing LOS and ensuring DOS discharged following UKA (Bradley et al. 2017). Finally, decreased LOS is also shown to increase patient satisfaction levels (Reilly et al. 2005, Richter and Diduch 2017).A study has been conducted to explore reasons for prolonged hospitalization in a fast-track setting following TKA (Husted et al. 2011). However, in spite of a growing number of UKAs performed each year, no study explicitly exploring reasons for prolonged hospitalization beyond DOS following UKA in a fast-track setting has been published at present.Therefore, we investigated reasons for continued hospitalization beyond DOS following UKA in a fast-track setting.     

The red man syndrome: Exfoliative dermatitis of unknown etiology: A description and follow-up of 38 patients

Thirty-eight patients with erythroderma of unknown etiology were diagnosed over a 15-year period, and represented 19% of all patients admitted to our department for erythroderma. The male:female ratio was 6.6:1, and the median disease duration was 2 years (range 1 to 23 years). Keratoderma of palms and/or soles was seen in 79%. Laboratory findings were normal, except for an increased IgE level in 69% of the patients studied. Lymph node histology showed dermatopathic lymphadenopathy. Bone marrow investigation results were normal in 48%, or showed eosinophilia (32%) or hyperplasia (20%). Initial skin biopsies showed nonspecific histology in most patients, but later biopsies revealed pleomorphic infiltration. During the observation period four patients progressed to mycosis fungoides and another nine patients were suspected of having mycosis. None developed Sézary's syndrome. Only one third of the patients went into complete remission; half of them died during the observation period. Patients with erythroderma of unknown etiology are predominantly men and seem to belong to a certain subgroup--herein called the red man syndrome.     

Accuracy assessment of cone beam computed tomography-derived laboratory-based surgical templates on partially edentulous patients

Objectives: The aim of the present prospective clinical study was to evaluate the match between the positions and axes of the virtually planned and the placed implants using laboratory‐based surgical guides generated from cone beam computed tomography (CBCT). Materials and methods: A total of 132 implants were placed with the aid of 3D‐based transfer templates in 52 consecutive partially edentulous patients between April 2008 and March 2010. After individual adaptation of the scan templates and CBCT scanning, the acquired data for virtual implant planning and simulation were processed using the med3D software program. After finalizing the virtual placement of the implants the radiographic templates were converted into operative guides containing titanium sleeves for cavity preparation. Preoperative planning was merged with postoperative CBCT data to identify linear and angular deviations between virtually planned and placed implants. Results: Compared with the planned implants the installed implants showed linear deviations in the median at the neck and apex of 0.27 mm (range 0.01–0.97 mm), and of 0.46 mm (range 0.03–1.38 mm), respectively. The angle deviation was 1.84° in median, with a range of 0.07–6.26°. The extent of deviation depends on the size of the tooth gap and the distribution of the remaining teeth. Conclusion: The results of this study suggested that laboratory‐fabricated surgical guides using CBCT data may be reliable in implant placement under prosthodontic considerations in partial edentulism. To cite this article:
Behneke A, Burwinkel M, Knierim K, Behneke N. Accuracy assessment of cone beam computed tomography‐derived laboratory‐based surgical templates on partially edentulous patients.
Clin. Oral Impl. Res. 23 , 2012; 137–143.
doi: 10.1111/j.1600‐0501.2011.02176.x