Sexual activity after short-stem total hip arthroplasty. Does stem size matter?

BACKGROUND

Sexual activity is an important component of quality of life. To date, no studies have examined the impact of stem design on return to sexual activity (RTS) and quality of sex life after total hip arthroplasty (THA).

METHODS

A questionnaire was designed to assess preoperative and postoperative sexual habits, joint awareness and physical activity in working-age patients undergoing short-stem (n = 176) or straight-stem (n = 97) THA.

RESULTS

No differences were noted in time until RTS based on the stem design (short stems vs. straight stems; 6 [IQR: 4-10] vs. 6 [4-10] weeks; p = 0.996). Multivariate analysis revealed that higher patient BMI (p = 0.04), female gender (p < 0.001) and lower FJS-12 (p = 0.006) were significantly associated with delayed RTS. Improved hip mobility and reduced pain mainly contribute to improved quality of sexual activity postoperatively.

CONCLUSION

This study, hence, indicates that stem design has no impact on time until resumption of sexual activity in patients < 65 years. Female obese individuals who are aware of their artificial joint in daily life are at increased risk of delayed RTS after surgery.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Simultaneous Bilateral Total Hip Arthroplasty with Straight-Stems and Short-Stems: Does the Short One Do a Better Job?

BACKGROUND

Total hip arthroplasty (THA) is known to be the most successful orthopaedic surgery of the last century, but it is still struggling with controversies concerning one-stage bilateral THA. The current study aimed to compare the clinical outcome of patients with unilateral or simultaneous bilateral THA by using short-stem and straight-stem designs and focusing on operation time, blood loss, and length of hospital stay (LOS).

MATERIAL AND METHODS

Between 2006 and 2018, 92 patients were enrolled in this study. Forty-six patients underwent a bilateral THA in one session, and forty-six matched patients underwent a unilateral THA. In each of the two groups (unilateral vs. bilateral), 23 patients received either a straight (unilateral: 10 females, 13 males, mean age 63; bilateral: 12 females, 11 males, mean age 53 years) or short stem (unilateral: 11 females, 12 males, mean age 60 years; bilateral: 12 females, 11 males, 53 mean age 62 years). The blood count was checked preoperatively as well as one and three days after surgery. Furthermore, the operation time and LOS were investigated.

RESULTS

Compared to THA with straight-stems, short-stem THA showed significantly less blood loss; there was no difference in the LOS of both groups. A significantly shorter operative time was only observed in the bilateral THA.

CONCLUSION

The current study showed that simultaneous bilateral THA appears to be safe and reliable in patients without multiple comorbidities. In addition, short-stem THA appears to be beneficial in terms of clinical performance and outcome, and it appears to be superior to straight-stem THA, regardless of whether the patient underwent unilateral or simultaneous bilateral THA.

Restoration of hip geometry after total hip arthroplasty: retrospective comparison of two short stems and one straight stem

BACKGROUND

The preservation or restoration of hip geometry following total hip arthroplasty (THA) is of importance, considering that alterations in the centrum-collum-diaphysis (CCD)-angle, femoral offset (FO), acetabular offset (AO) and total offset (TO) change hip biomechanics. Therefore, the most suitable implant should be used. The aim of this study was to compare the ability of two short-stem-systems and one straight-stem-system to reconstruct hip geometry.

METHODS

Two-hundred-fifty-one patients (mean age: 62.0 ± 10.0 years; 51.8% males) undergoing THA with three different stem types were retrospectively included, after excluding 11 patients with missing radiological follow-up. Pre- and postoperative radiographic images (group I, ANA.NOVA Alpha Schaft Proxy®, ImplanTec, 12 options: n = 99; group II, Optimys® Mathys, 24 options: n = 62; group III: Corail®-System, DePuy-Synthes, 76 options: n = 90) were analyzed. Differences in pre- and postoperative hip geometry (i.e. CCD, FO, AO, TO) were compared between groups with one-way-analysis-of-variance (ANOVA), and post-hoc t-tests.

RESULTS

The CCD-angle increased by a mean of 8.4° ± 7.2° from pre-to postoperative, with no significant difference between groups (p = 0.097). Significantly larger increases in FO were observed for groups II (4.1 mm ± 7.8 mm) and III (4.9 ± 7.2 mm), in comparison to group I (1.6 ± 6.9 mm; p = 0.006). AO decreased by a mean of 2.2 ± 4.5 mm, with the largest decrease observed in group III (-3.3 ± 5.3 mm), and the smallest for group I (-1.4 ± 3.6 mm; p = 0.011). There was no significant difference in change of TO between groups (p = 0.177).

CONCLUSIONS

Reconstruction of hip geometry using a single-version novel short-stem-system is achievable with comparable results to stem-systems offering multiple options.

Three-year migration analysis of a new metaphyseal anchoring short femoral stem in THA using EBRA-FCA

Cementless calcar-guided femoral short stems in total hip arthroplasty (THA) have become increasingly popular over the years. Early distal migration of femoral stems measured by Einzel-Bild-Roentgen Analyse, Femoral Component Analyse (EBRA-FCA) has been reported to be a risk factor for aseptic loosening. The aim of this study was to analyse axial migration behavior and subsidence of a new short stem (launched in 2015) over a follow-up period of 3 years. According to the study protocol, 100 hip osteoarthritis patients who consecutively received an unilateral cementless calcar-guided short stem (ANA.NOVA proxy) at a single department were prospectively included in this mid-term follow-up study. Thirteen patients were lost to follow-up, resulting in 87 patients with unilateral THA who fulfilled the criteria for migration analysis with EBRA-FCA. The cohort comprised 41 males (mean age: 60 ± 16.5; mean BMI (Body Mass Index): 30 ± 13) and 46 females (mean age: 61 ± 15.5; mean BMI: 27 ± 10). Seven standardized radiographs per patient were analyzed with EBRA-FCA. An average migration of 2.0 mm (0.95-3.35) was observed within the first 3 years. The median increase during the first year was higher than in the second and third year (1.2 mm [IQR: 0.5-2.15] vs. 0.3 mm [IQR: 0.1-0.6 mm] vs. 0.25 mm [IQR: 0.1-0.5 mm]. Detected migration did not lead to stem loosening, instability, dislocation, or revision surgery in any patient. A higher risk for subsidence was observed in male and heavyweight patients, whereas the female gender was associated with a lower risk. No correlation between migration and revision could be observed. Although moderate subsidence was detectable, the performance of the short stem ANA.NOVA proxy is encouraging. Yet, its use may be re-considered in overweight and male patients due to more pronounced subsidence.

Pre-operative templating in THA using a short stem system: precision and accuracy of 2D versus 3D planning method

Background

Total hip arthroplasty (THA) is the most successful orthopaedic surgery of the past century. The current study aimed to compare the accuracy of digital planning using 2D versus 3D templating.

Materials and methods

Ninety-five THAs in 90 patients were included in the current study. Pre- and post-operative X-rays (in two planes) and low-dose rotation computed tomography scans from hip to foot were performed. Paired t-test and regression analyses were conducted to compare 2D and 3D templating accuracy of the definitive implant.

Results

Cup size planned both with 2D (p < 0.0001) and 3D (p = 0.012) templating was significantly different from the definitively used cup size. The difference between the 2D-planned and implanted stem size (p < 0.0001) was statistically significant. In contrast, there were no significant differences in the 3D-planned and implanted stem size (p = 0.181). Three-dimensional templating showed significantly higher accuracy than 2D templating in terms of cup size (1.1 ± 1.4 versus 1.7 ± 1.8; p = 0.007) and stem size (0.3 ± 0.6 versus 0.7 ± 0.7; p < 0.0001).

With increasing body mass index (BMI), 2D templating of the stem became more inaccurate (p = 0.041). Remarkably, 3D templating remained accurate for all components (stem, p = 0.533; cup, p = 0.479) despite increasing BMI.

Conclusion

Despite extended planning time and increased exposure to radiation, 3D-based planning showed higher accuracy than 2D templating, especially in obese patients. On the basis of our results, we believe that 3D-based pre-operative planning in THA is justifiable and beneficial in patients with increased BMI.

Level of Evidence

III.

Leg length measures appear inaccurate in the early phase following total hip arthroplasty

The aims of this study were to (1) assess reliability of leg length discrepancy (LLD) measurements at different anatomical landmarks, (2) longitudinally investigate LLD in patients within the first year following total hip arthroplasty (THA) and to (3) correlate changes in LLD with functional outcome. Ninety-nine patients with short stem THA (53.3% males, mean age: 61.0 ± 8.1 years) were prospectively included. Upright pelvic anteroposterior (a.p.) radiographs taken at 6 timepoints (preoperatively, discharge, 6, 12, 24, 52 weeks postoperatively) were used to assess LLD at 5 anatomical landmarks (iliac crest, upper sacroiliac joint, lower sacroiliac joint, tear drop figure, greater trochanter). WOMAC and Harris Hip Score (HHS) were obtained preoperatively and at 6 and 52 weeks. LLD measures significantly increased in the initial phase following THA, from discharge to 6 weeks postoperatively and remained constant thereafter. Documentation of LLDs is dependent on measurement site: LLDs varied significantly between trochanter and iliac crest to tear drop figure (p < 0.001). Functional assessments did not correlate with the occurrence of LLDs [WOMAC (p = 0.252); HHS (p = 0.798)]. Radiographic assessment of LLD following THA may not be performed early postoperatively, as measurements appear to inaccurately reflect actual LLDs at this time, potentially due incomplete leg extension and/or inhibited weight-bearing.

Periprosthetic fractures of hip and knee-A morbidity and mortality analysis

BACKGROUND

Periprosthetic fractures (PPF) following total knee (TKA) and hip arthroplasty (THA) have become more common over the years. The aim of the present study was to assess morbidity and mortality following surgery for PPF of hip and knee.

PATIENTS AND METHODS

Altogether, 124 patients (mean age: 77 years; 77.4% female) with PPF of the hip (n=97) and knee (n=27), treated between 2005 and 2017 at a level-1 trauma centre, were retrospectively included. In order to assess risk factors for postoperative morbidity, Fine and Gray's model was used to compensate for death as the competing event. Risk factors for mortality were estimated with uni- and multivariate Cox-regression models.

RESULTS

Vancouver B2 fractures were most common (n=39; 42.4%), followed by B1 fractures (n=23; 25.0%). Lewis-Rorabeck Type I fractures (n=14; 51.9%) were most frequent in PPF of the knee. Overall complication rates were 44.0% and 29.9% for PPF of the knee and hip, respectively, with three patients having both early and late complications, 25 patients developing early complications and 19 patients undergoing surgery for implant-related, late complications. In the multivariate Fine and Gray model, advanced patient age (HR: 0.956; 95%CI: 0.922-0.991; p=0.014) and prosthesis exchange (vs. ORIF; HR: 0.242, 95%CI: 0.068-0.859; p=0.028) were associated with lower risk of implant-related complications, irrespective of gender (p=0.450) and a surgical delay > 2 days (p=0.411). One- and 5-year overall survival-rates were 97.9% and 93.1%, respectively. Gender, type of fixation (ORIF vs. prosthesis exchange), surgical delay > 2 days, BMI and age at surgery were neither in the univariate, nor multivariate Cox-regression model associated with an increased mortality rate.

CONCLUSION

Postoperative morbidity caused by implant-related complications is higher in younger patients and those receiving ORIF. With the statistical approach used, potential underestimation of actual complication rates may have been avoided, taking into account death as the competing event. Despite being based on a retrospective, heterogenous patient collective treated at a level-1 trauma centre, our results indicate that careful planning of the surgical procedure beyond 2 days, taking into consideration both patient's age and activity level, has no negative effect on patient outcome.

Short-stem total hip arthroplasty is not associated with an earlier return to work compared to a straight-stem design

Return to work (RTW) has been specifically identified as a high priority in patients undergoing total hip arthroplasty (THA). This investigation sought to assess the effect of the stem design on patients' RTW. Secondly, the study aimed to identify risk factors that lead to a delayed RTW. Questionnaires inquiring about RTW, employment history, educational level, type of work, physical demands and joint awareness were administered by post. Further data were collected from patients' hospital records. 176 patients who underwent THA using a short-stem and 97 patients using a straight-stem design were compared. The median return to work time was 10 weeks [IQR 7-14 weeks], with no significant difference between the two groups (short stems vs. straight stems; 10 [IQR 7-14] vs. 11 [7.5-13.5] weeks; p = 0.693). In the multivariate linear regression analysis, self-employment vs. employee (p = 0.001), dimension of preoperative workload (p = 0.001), preoperative sick leave (p < 0.001), and hospital length of stay (LOS) (p < 0.001) independently affected the period until work was resumed. The Forgotten-Joint-Score-12 showed no significant difference between the two groups. The data show that the majority of THA patients can expect to resume work and stem design has no impact on RTW. Employees with preoperative sick leave, prolonged hospital LOS and low workload are at higher risk for a delayed RTW.

Patients with hip fracture and total hip arthroplasty surgery differ in anthropometric, but not cardiovascular screening abnormalities

Background

With the rising number of hip surgeries, simple and cost-effective tools for surgery risk assessment are warranted. The analysis of heart rate variability (HRV) may not only provide critical insights into the general frailty of patients with hip surgery, but also allow for better differentiation of health profiles in different hip surgery groups. Using HRV analysis, the present study compared cardiovascular as well as anthropometric parameters between patients with hip surgery, the hip fracture surgery group (HFS) and the total hip arthroplasty group (THA), and a control group.

Methods

71 participants (56.3% women), aged 60–85 years, took part, divided into three groups—patients after hip surgery (21 HFS and 30 THA patients) and a control group (20 participants). Electrocardiogram was recorded at baseline and after the application of a physical stressor (grip strength). A 3 (group) × 2 (time) repeated measures ANOVA, and a chi square test were carried out to test for group differences.

Results

Higher weight (p = .002), body mass index (p = .001), and systolic blood pressure (p = .034) were found in THA patients compared to HFS patients. Lower calf circumference (p = .009) and diastolic blood pressure (p = .048) were observed for the HFS group compared to the control group. For cardiovascular parameters, significant differences emerged between the HFS group and the control group in HR (p = .005), SDNN (p = .034) and SD2 (p = .012). No significant differences in cardiovascular parameters were observed between the two hip surgery groups: neither at baseline nor during stressor recovery.

Conclusions

While HRV seems to differentiate well between HFS patients and controls, more research with larger samples is needed to scrutinize similaritites and differences in cardiovascular profiles between HFS and THA patients.

Blood Management in Revision Total Hip Arthroplasty for Metal-on-Metal Devices: The Efficiency of an Intraoperative Cell Salvage System

BACKGROUND

The aim of this series was to investigate the efficiency of an intraoperative cell salvage system (ICS) removing metal ions during revision of metal-on-metal (MoM) devices to proof the possibility of re-transfusion of the collected blood.

MATERIALS AND METHODS

Between 2014 and 2018, five consecutive patients underwent revision surgery of their MoM total hip arthroplasty due to wear of the polyethylene-metal sandwich inlay or local massive metallosis with aseptic loosing of the cup. Aspiration of joint fluid of all hip prostheses was done and blood was taken to measure the metal ion concentrations, preoperatively. Perioperatively, blood was collected using an ICS before and after filtration and analyzed for Co and Cr concentrations. At that time, there was no re-transfusion of the collected and filtrated blood due to unknown metal ion concentrations.

RESULTS

The mean preoperative serum Co and Cr concentrations in the blood were 31.28 μg/L (range 0.22-77.47) and 17.33 μg/L (range 0.59-51.31), whereas the mean local concentrations in the aspiration fluid were 728-fold and 822-fold higher. The Co and Cr concentrations measured in the collected blood before filtration were 70.61 μg/L (range 9.40-173.00) and 337.21 μg/L (range 8.76-1383.0) and decreased markedly to average concentrations of 15.49 μg/L and 41.88 μg/L, respectively. These differences were statistically not significant (Co: p = 0.117, Cr: p = 0.175), although the mean reduction rates were 78% and 88% for Co and Cr, respectively.

CONCLUSION

The current series showed that in case of revision of MoM hip devices, metal ions are still contained in the collected blood following filtration using a modern high-level ICS. Therefore, we would only recommend blood re-transfusion in case of low preoperative Co and Cr concentrations and sufficient renal function to warrant patients' safety.

Pain in fibrous dysplasia: relationship with anatomical and clinical features

Background and purpose - Fibrous dysplasia (FD) is a rare bone disorder associated with pain, deformities, and pathological fractures. The pathophysiological mechanism of FD-related pain remains ill-understood. We evaluated the degree of pain and the potential contributory factors in 2 patient cohorts from Austria and the Netherlands. Patients and methods - 197 patients (16-85 years) with FD (Graz n = 105, Leiden n = 92) completed a survey concerning the presence and severity of pain at their FD site. Sex, age, type of FD, and localization of FD lesions were examined for a relationship with the presence and severity of pain. Results - Of 197 patients from the combined cohort (61% female, mean age 49 (SD 16) years, 76% monostotic) who completed the questionnaires, 91 (46%) reported pain at sites of FD lesions. Severity of pain was higher in patients with lesions of the lower extremities and ribs compared with upper extremity or craniofacial lesions. Severe subtypes of FD (polyostotic/McCune-Albright syndrome) were more often associated with pain, often severe. Interpretation - Our data suggest that almost 50% of patients with FD report pain at FD sites, thus representing a major clinical manifestation of the disorder, importantly also in patients with monostotic lesions. Lesions in lower extremities and ribs were more painful.

[Silver coating on tumour prostheses]

BACKGROUND

Modular endoprostheses, so-called "tumour or megaprostheses" are mainly used for limb salvage surgery after resection of malignant soft tissue or a bone tumour. Sometimes, this type of prosthesis is also used for revision surgeries after failed primary joint arthroplasty. Despite continuously improving techniques and quality management systems, periprosthetic infection is one of the most serious complications.

AIM OF THE STUDY

Review of the literature in the PubMed data base with the main focus on silver coatings in joint arthroplasty and their effect on infection rate, outcome and patients' safety.

RESULTS

The current literature shows that there is a beneficial role of silver coatings in megaprostheses in terms of revision rates for septic complications, especially following tumour resection with bad soft tissue coverage or in (multimorbid) high-risk patients, compared to uncoated implants.

DISCUSSION

Based on the results of previous publications examining blood or serum silver concentrations or silver levels in urine, silver coatings do not appear to have side effects, except for local argyria. Continuous monitoring of silver levels in blood or serum is still recommended, and additional long-term studies will be necessary to verify the effectiveness and safety of silver coatings.

The accuracy of digital templating in uncemented total hip arthroplasty

INTRODUCTION

Preoperative planning is an essential part of total hip arthroplasty (THA). It facilitates the surgical procedure, helps to provide the correct implant size and aims at restoring biomechanical conditions. In recent times, surgeons rely more and more on digital templating techniques. Although the conversion to picture archiving and communication system had many positive effects, there are still problems that have to be taken into consideration.

OBJECTIVES

The core objective was to evaluate the impact of the planners' experience on the accuracy of predicting component size in digital preoperative templating of THA. In addition, the influence of overweight and obesity (according to WHO-criteria), patient's sex and component design on the accuracy of preoperative planning have been analysed.

MATERIALS AND METHODS

The retrospective study included 632 consecutive patients who had primary uncemented THA. Digital templating was done using "syngo-EndoMap" software by Siemens Medical Solutions AG. Mann-Whitney U test and Kruskal-Wallis test have been used for statistical analysis. The accuracy of predicting component size has been evaluated by comparing preoperative planned sizes with implanted sizes as documented by the surgeons. The planner's experience was tested by comparing the reliability of preoperative planning done by senior surgeons or residents. The influence of BMI on predicting component size has been tested by comparing the accuracy of digital templating between different groups of BMI according to WHO-criteria. The same procedure has been done for evaluating the impact of patient´s sex and component design.

RESULTS

The implant size was predicted exactly in 42% for the femoral and in 37% for the acetabular component. 87% of the femoral components and 78% of the acetabular cups were accurate within one size. Digital templating of femoral implant size was significantly more reliable when done by a senior surgeon. No difference was found for the acetabular component sizes. The BMI also had an impact on estimating the correct femoral implant size. In overweight patients, planning was significantly more inaccurate than normal weight people. Differences were seen in obese patients. However, these were not significant. Accuracy of acetabular components was not affected. The design of the prostheses and the patient's sex had no influence on predicting component size.

CONCLUSIONS

Inexperience and overweight are factors that correlate with inaccuracy of preoperative digital templating in femoral components, whereas acetabular components seem to be independent of these factors.

Survival Rate of Short-Stem Hip Prostheses: A Comparative Analysis of Clinical Studies and National Arthroplasty Registers

BACKGROUND

The primary aim was to evaluate the outcome of short-stem hip prostheses in terms of overall revision rates. Data were taken from published literature and national arthroplasty registers. The second study aim was to evaluate a potentially superior outcome of dependent compared to independent clinical studies.

METHODS

All clinical studies on short-stem hip prostheses between 2006 and 2016 were reviewed and evaluated with a special interest on revision rates. Revision rate was calculated as "revision per 100 component years." Short stems were divided into femoral neck retaining (NR), neck sparing (NS), and neck harming (NH) prostheses. Published literature was further classified into dependent and independent studies, and data were compared to the Australian National Arthroplasty Register.

RESULTS

Fifty-two studies with 56 cohorts met the inclusion criteria and were therefore included in our study. All clinical studies showed a median revision rate of 4.8% after 10 years. NS and NH stems performed equally, whereas neck retaining prostheses were significantly inferior. Independent showed higher revision rates compared to dependent data without being statistically significant. The Australian register revealed a revision rate of 6.6% after one decade.

CONCLUSION

Similar low revision rates for NS and NH short-stem prostheses were found in the included data. Dependent studies seem not to be biased with regard to the longevity of short-stem hip replacement. Longer follow-up periods in clinical studies and more detailed information in arthroplasty registers would be desirable for future studies.

Clinical experience with the artificial bone graft substitute Calcibon used following curettage of benign and low-grade malignant bone tumors

Artificial bone graft substitutes, such as Calcibon, are becoming increasingly interesting as they do not cause donor site morbidity which is an advantage compared to autologous bone grafts. The aim of this study was to evaluate the efficacy and potential complications associated with the use of Calcibon. Twenty-seven patients with benign and low-grade malignant bone tumors were treated with curettage and refilling of the bony cavity. Based on the radiological classification system of Neer, these lesions only comprised Grade I lesions, describing cysts that only require curettage and filling, but no additional treatment. At a mean follow up of six months we observed radiological consolidation without resorption of the bone graft substitute. These observations were also made at a mean follow-up of 13 and 32 months, respectively. According to the classification system of Goslings and Gouma we observed six surgical complications. Summing up, Calcibon seems to be a reliable bone graft substitute with low complication rates. However, delayed resorption should be expected. Calcibon seems to be an alternative to autologous bone grafts or allografts in adequate indications.

Recall of the ASR XL Head and Hip Resurfacing Systems

At the beginning of the 21st century, use of large-diameter, metal-on-metal devices was a popular procedure for hip replacement in young and physically active patients; however, within a few years, the number of revisions increased, resulting in a worldwide recall for the articular surface replacement (ASR) system. Complication rates for the ASR devices implanted at the authors' department are reported, with revision rates of 32% and 30% in the ASR XL Head and ASR Resurfacing groups, respectively. Reasons for revision surgery were serum metal ion elevation, luxation or subluxation, aseptic loosening, soft tissue compromise (adverse reactions to metal debris [ARMD]), and infection. The calculated implant survival for the ASR XL Head system and the ASR Resurfacing device (DePuy Orthopaedics Inc, Warsaw, Indiana) in the current series was 79% and 90%, respectively, at 60 months. Symptomatic patients with metal-on-metal devices, with or without elevated metal ion concentrations, should undergo cross sectional imaging to exclude ARMD. In cases of increased metal ion concentrations, local pain, or ARMD, revision surgery has to be evaluated. In the future, closer monitoring of new implants is needed to prevent high failure rates, as seen with the ASR design. Furthermore, the withdrawal of the device highlights the importance of national implant registries. [Orthopedics. 2017; 40(2):e340-e347.].

The width of resection margins influences local recurrence in soft tissue sarcoma patients

BACKGROUND

Patients with soft tissue sarcoma (STS) being treated following the standardized guidelines can still not be guaranteed to remain free from local recurrence (LR). A complete tumour resection has been accepted as a major prognostic factor for LR. This retrospective study was designed to analyse the influence of two different classifications of resection margins (R-classification and UICC-classification) on LR in STS patients.

MATERIALS AND METHODS

Of 411 patients treated at our institution for STS, 265 were eligible for statistical analysis. Kaplan-Meier curves and Cox regression models were used to assess the impact of an R0 resection according to the R-classification (resection margin clear but allowing <1 mm) and according to the UICC-classification (minimal resection margin ≥1 mm) on LR.

RESULTS

Survival curves showed a lower LR rate for R0 resections in the UICC-classification, namely 1.3%, 12% and 12% as compared to 2.1%, 9.5% and 16.5% for the R-classification. In multivariate analysis calculated separately for each classification, R1 resection as defined by the R-classification (HR: 11.214; 95%CI: 2.394-52.517; p = 0.002) as well as by UICC-classification (HR: 15.634; 95%CI: 2.493-98.029; p = 0.003) remained significant.

CONCLUSION

In our study, margin status according to both classifications represents an independent prognostic factor for LR in patients with STS following curative surgery. Local control rates were superior after a minimal resection margin of 1 mm (R0 by UICC-classification) compared to R0 resections after the R-classification.

Paley's multiplier method does not accurately predict adult height in children with bone sarcoma

BACKGROUND

The majority of patients with osteosarcoma and Ewing's sarcoma are diagnosed before skeletal maturity. Paley's multiplier is used for height prediction in healthy children, and has been suggested as a method to make growth predictions for children with osteosarcoma and Ewing's sarcoma when considering limb salvage options. To our knowledge, no evaluation of this method in this particular patient group has been performed, but a temporary growth deficit has been observed in children undergoing chemotherapy.

QUESTIONS/PURPOSES

We asked whether (1) Paley's formula reliably predicts growth in children who received polychemotherapy; (2) chemotherapy impairs growth velocity; and (3) final adult height is impaired in these patients.

METHODS

Retrospectively, data for 94 patients with osteosarcoma and Ewing's sarcoma were retrieved from databases of two sarcoma centers. Onset before 14 years of age in girls and 16 years in boys and a minimum followup until 18 years were required (mean, 67 months; range, 31-124 months) criteria. Exclusion criteria were the intake of growth hormones or no chemotherapy. Thirty-three patients (35%) fulfilled all inclusion criteria. Predicted adult heights were compared with actual adult height. The development of a growth deficit was evaluated for 23 children (without chemotherapy for recurrence) using age- and gender-specific standard deviation scores for height (WHO Z-scores).

RESULTS

Height prediction using Paley's method showed a high percentage of false predictions (outside ± 1 SD, 70%; outside ± 2 SD, 61%). On average, the mean total height of the patients was overestimated (2.3 cm). The median absolute error of prediction was 5.0 cm (range, -17 to 8). Patients with osteosarcoma and Ewing's sarcoma showed a significant growth impairment during polychemotherapy. A catchup phase in growth before skeletal maturity was observed in patients with osteosarcoma but not with Ewing's sarcoma.

CONCLUSIONS

Owing to its lack of reliability in this patient group, methods other than Paley's should be evaluated to predict adult height. Although limited by a small number of patients, our study results indicate a decreased adult height in patients with bone sarcoma after chemotherapy.

LEVEL OF EVIDENCE

Level III, therapeutic study. See the Instructions for Authors for complete description of levels of evidence.

Surgical therapy of primary malignant bone tumours and soft tissue sarcomas of the chest wall: a two-institutional experience

PURPOSE

Primary malignant bone tumours and soft tissue sarcomas of the chest wall are exceedingly rare entities. The aim of this study was a retrospective two-institutional analysis of surgical therapy with respect to the kind and amount of the resection performed, the type of reconstruction and the oncological outcome.

METHODS

Between September 1999 and August 2010 31 patients (seven women and 24 men) were treated due to a primary malignant bone tumour or soft tissue sarcoma of the chest wall in two centres. Eight low-grade sarcomas were noted as well as 23 highly malignant sarcomas. The tumours originated from the sternum in six cases, from the ribs in 12 cases, from the soft tissues of the thoracic wall in 11 cases and from a vertebral body and the clavicle in one case each.

RESULTS

In 26 cases wide resection margins were achieved, while four were intralesional and one was marginal. In all 31 cases the defect of the chest wall was reconstructed using mesh grafts. At a mean follow-up of 51 months 20 patients were without evidence of disease, three were alive with disease, seven patients had died and one patient was lost to follow-up. One recurrence was detected after wide resection of a malignant triton tumour.

CONCLUSIONS

Primary malignant bone tumour or soft tissue sarcoma of the chest wall should be treated according to the same surgical oncological principles as established for the extremities. Reconstruction with mesh grafts and musculocutaneous flaps is associated with a low morbidity.

Validation of the prognostic relevance of plasma C-reactive protein levels in soft-tissue sarcoma patients

BACKGROUND

The concept of the involvement of systemic inflammation in cancer progression and metastases has gained attraction within the past decade. C-reactive protein (CRP), a non-specific blood-based marker of the systemic inflammatory response, has been associated with decreased survival in several cancer types. The aim of the present study was to validate the prognostic value of pre-operative plasma CRP levels on clinical outcome in a large cohort of soft-tissue sarcoma (STS) patients.

METHODS

Three hundred and four STS patients, operated between 1998 and 2010, were retrospectively evaluated. CRP levels and the impact on cancer-specific survival (CSS), disease-free survival (DFS) and overall survival (OS) were assessed using Kaplan-Meier curves and univariate as well as multivariate Cox proportional models. Additionally, we developed a nomogram by supplementing the plasma CRP level to the well-established Kattan nomogram and evaluated the improvement of predictive accuracy of this novel nomogram by applying calibration and Harrell's concordance index (c-index).

RESULTS

An elevated plasma CRP level was significantly associated with established prognostic factors, including age, tumour grade, size and depth (P<0.05). In multivariate analysis, increased CRP levels were significantly associated with a poor outcome for CSS (HR=2.05; 95% CI=1.13-3.74; P=0.019) and DFS (HR=1.88; 95% CI=1.07-3.34; P=0.029). The estimated c-index was 0.74 using the original Kattan nomogram and 0.77 when the plasma CRP level was added.

CONCLUSION

An elevated pre-operative CRP level represents an independent prognostic factor that predicts poor prognosis and improves the predictive ability of the Kattan nomogram in STS patients. Our data suggest to further prospectively validate its potential utility for individual risk stratification and clinical management of STS patients.

Argyria following the use of silver-coated megaprostheses: no association between the development of local argyria and elevated silver levels

The aims of this study were to evaluate the incidence of local argyria in patients with silver-coated megaprostheses and to identify a possible association between argyria and elevated levels of silver both locally and in the blood. Between 2004 and 2011, 32 megaprostheses with silver coatings were implanted in 20 female and 12 male patients following revision arthroplasty for infection or resection of a malignant tumour, and the levels of silver locally in drains and seromas and in the blood were determined. The mean age of the patients was 46 years (10 to 81); one patient died in the immediate post-operative period and was excluded. Seven patients (23%) developed local argyria after a median of 25.7 months (interquartile range 2 to 44.5). Patients with and without local argyria had comparable levels of silver in the blood and aspiration fluids. The length of the implant did not influence the development of local argyria. Patients with clinical evidence of local argyria had no neurological symptoms and no evidence of renal or hepatic failure. Thus, we conclude that the short-term surveillance of blood silver levels in these patients is not required.

The role of somatostatin receptor scintigraphy on the diagnosis of desmoid tumors

Background. Magnetic resonance imaging is considered as imaging modality of choice in diagnosis of desmoid tumors, though even this technique can lack the ability to distinguish aggressive fibromatosis from other benign or malignant soft tissue tumors. The aim of this study was to investigate if desmoid tumors would show an adequate tracer uptake in somatostatin receptor scintigraphy and moreover to correlate these results with immunohistochemical staining. Patients and Methods. Thirteen patients with desmoid tumors were examined with somatostatin receptor scintigraphy. Additionally, seven of these patients have been tested for the immunohistochemical expression of somatostatin receptor subtype 2A. The results of somatostatin receptor scintigraphy and the results of immunohistochemical staining (somatostatin receptor subtype 2A) were evaluated and correlated. Results. Somatostatin receptor scintigraphy revealed that eight of 13 affected patients (62%) showed an enhanced tracer uptake. On the other hand, the correlation between the results of somatostatin receptor scintigraphy and immunohistochemical investigations was poor (two out of seven cases). Conclusion. The current study demonstrated that desmoid tumors frequently express somatostatin receptor subtype 2, while immunohistochemical investigations did not correlate with these findings. This may likely be due to lack of standardization of this technique and also due to heterogeneous receptor distribution within the tumors.

Metal ion levels in large-diameter total hip and resurfacing hip arthroplasty--preliminary results of a prospective five year study after two years of follow-up

Background

Metal-on-metal hip resurfacing is an alternative to metal-on-metal total hip arthroplasty, especially for young and physically active patients. However, wear which might be detected by increased serum ion levels is a matter of concern.

Methods

The aims of this preliminary study were to determine the raise of metal ion levels at 2-years follow-up in a prospective setting and to evaluate differences between patients with either resurfacing or total hip arthroplasty. Furthermore we investigated if the inclination of the acetabular component and the arc of cover would influence these findings. Therefore, 36 patients were followed prospectively.

Results

The results showed increments for Co and Cr in both implant groups. Patients treated with large-diameter total hip arthroplasty showed fourfold and threefold, respectively, higher levels for Co and Cr compared to the resurfacing group (Co: p < 0,001 and Cr: p = 0,005). Nevertheless, we observed no significant correlation between serum ion levels, inclination and arc of cover.

Discussion

In order to clarify the biologic effects of ion dissemination and to identify risks concerning long-term toxicity of metals, the exposure should be monitored carefully. Therefore, long-term studies have to be done to determine adverse effects of Co and Cr following metal-on-metal hip replacement.

In vivo testing of knee stability after rotating-hinge total knee arthroplasty: a comparison of 2 knee systems

Rotating-hinge knee prostheses are used for reconstruction in cases of severe articular compromise and major bone loss. Biomechanical studies revealed that rotating-hinge designs with long and cylindrical pegs are more stable than devices with short and more tapered ones. Twenty-five patients underwent clinical examination using ultrasound, radiographs, and 3 different rating systems to examine the in vivo stability and functional outcome of 2 rotating-hinge knee systems. Overall, the study revealed that a stable reconstruction could be achieved with both tested devices, with good functional outcome. The results for medial and lateral lift-off during flexion and extension in ultrasonography were comparable, whereas the measured distraction of the Limb Preservation System (LPS/M.B.T.; DePuy, Warsaw, Indiana) was lower compared with the S-ROM Noiles prostheses (DePuy). The implant, the new formed capsule, and the remaining soft tissues have to maintain joint stability. Soft tissue reconstruction, especially the medial gastrocnemius flap, and the newly formed periprosthetic scar seems to prevent distraction of several millimeters. In addition, determining the lift-off with ultrasonography showed that the shape of the peg does not influence implant's stability against lateral directed forces.

Failure rate of a rotating hinge knee design due to yoke fracture of the hinged tibial insert: a retrospective data analysis and review of the literature

PURPOSE

Rotating hinge knee prostheses are known to provide inherent stability. Yoke fractures of the hinged tibial insert of modern generation rotating hinge devices are a matter of continued concern. The aim of this study was to describe incidence and management of yoke fracture of the LPS™ hinged tibial insert.

METHODS

Retrospective data analysis of two institutions identified 40 patients with a LPS™ total knee arthroplasty. Implant survival and prosthetic complications was calculated according to Kaplan-Meier.

RESULTS

Out of the group of 40 patients, four fractures of the metal yoke occurred in four cases (failure rate: 10%). Furthermore, a second fracture occurred in two patients. The overall revision-free prosthetic survival was 57% at 38 months, while prosthetic survival until yoke fracture was 86% at 38 months.

CONCLUSION

Handling yoke fractures as mechanical complication includes replacing the hinged insert, stabilization of the joint and joint line height preservation in order to decrease the cantilever effect at the insert-base plate interface.

Auto-aggressive metallic mercury injection around the knee joint: a case report

BACKGROUND

Accidental or intentional subcutaneous and/or intramuscular injection of metallic mercury is an uncommon form of poisoning. Although it does not carry the same risk as mercury vapour inhalation, it may cause destructive early and late reactions.

CASE PRESENTATION

Herein we present the case of a 29-year-old male patient who developed an obsessive-compulsive disorder causing auto-aggressive behaviour with injection of elemental mercury and several other foreign bodies into the soft tissues around the left knee about 15 years before initial presentation. For clinical examination X-rays and a CT-scan of the affected area were performed. Furthermore, blood was taken to determine the mercury concentration in the blood, which showed a concentration 17-fold higher than recommended. As a consequence, the mercury depots and several foreign bodies were resected marginally.

CONCLUSION

Blood levels of mercury will decrease rapidly following surgery, especially in combination with chelating therapy. In case of subcutaneous and intramuscular injection of metallic mercury we recommend marginal or wide excision of all contaminated tissue to prevent migration of mercury and chronic inflammation. Nevertheless, prolonged clinical and biochemical monitoring should be performed for several years to screen for chronic intoxication.

Noninflammatory pseudotumor simulating venous thrombosis after metal-on-metal hip resurfacing

Metal-on-metal hip resurfacing has become a widespread procedure, especially in young, physically active patients. Pseudotumor is a new complication that can occur after hip resurfacing and metal-on-metal total hip arthroplasty (THA). This article presents a case of a 37-year-old woman who underwent metal-on-metal resurfacing of the left hip for symptomatic osteoarthritis. Twelve months following implantation, the patient reported painless swelling of the left lower leg. There was no clinical evidence of a deep venous thrombosis. Ultrasound and computed tomography showed a solid cystic lesion in the iliopsoas muscle, which communicated with the hip joint and compressed the external iliac vein. As a consequence, the cystic lesion was resected marginally. A few months later, the patient reported some discomfort in the groin and symptoms of instability, metallic clicking, and a restricted range of motion. Clinical and radiological examination revealed normal findings. Determining the serum concentration of cobalt and chromium revealed high increased levels of these metal ions. Ten months following excision of the pseudotumor, the patient reported recurrent swelling of the left lower leg. Computed tomography of the affected area showed a lobulated cystic formation; therefore, a relapse was suspected. At the second revision, the mass was excised and the implant was revised to a conventional ceramic-on-ceramic THA. At 30-month follow-up, the patient was doing well and there were no signs of local recurrence. Additionally, the metal ion levels of cobalt and chromium in the blood had significantly decreased.

Wikipedia and osteosarcoma: a trustworthy patients' information?

The English version of the online encyclopedia, Wikipedia, has been recently reported to be the prominent source of online health information. However, there is little information concerning the quality of information found in Wikipedia. Therefore, we created a questionnaire asking for scope, completeness, and accuracy of information found on osteosarcoma. Three independent observers tested the English version of Wikipedia, as well as the patient version and the health professional version of the US National Cancer Institute (NCI) website. Answers were verified with authoritative resources and international guidelines. The results of our study demonstrate that the quality of osteosarcoma-related information found in the English Wikipedia is good but inferior to the patient information provided by the NCI. Therefore, non-peer-reviewed commonly used websites offering health information, such as Wikipedia, should include links to more definitive sources, such as those maintained by the NCI and professional international organizations on healthcare treatments. Furthermore, frequent checks should make sure such external links are to the highest quality and to the best-maintained aggregate sites on a given healthcare topic.

[Clinical and radiological outcome after trapezium resection with suspension and interposition arthroplasty]

INTRODUCTION

Trapezium resection with suspension and interposition arthroplasty of the thumb-carpometacarpal joint is a common method for treatment of severe osteoarthritis of the 1st carpometacarpal joint.

METHODS

We performed a single center retrospective data analysis after trapezium resection with suspension and interposition arthroplasty of the thumb-carpometacarpal joint with emphasis on quality of life and radiological parameters 3.4 years (1.2-8.7 years) after operation in 60 patients. Pre- and postoperative pain was analysed with VAS, function was measured using the DASH score, pinch grip power with a pinchmeter.

RESULTS

Subjective outcome was rated excellent in 42 cases (64.6%), good in 17 (26.2%), fair in 3 (4.6%) and 3 times (4.6%) poor. 56 patients (93.3%) would like to be operated again; 4 patients (6.7%) would deny an operation retrospectively. In the VAS pain was reduced by about 75% compared to the preoperative value. The pinch grip was increased by 46.6% compared to the preoperative value. The rate of major complications was 1.5% and of minor complications 9.2 %.

CONCLUSION

Trapezium resection with suspension and interposition arthroplasty can increase the quality of life and reduce pain in patients with severe osteoarthritis of the 1st carpometacarpal joint. The rate of complications is low. Outcome assessment is possible by subjective parameters. Objective values like the range of movement or the decrease of the distance between metacarpal I and scaphoid do not correlate with outcome.

Biopsy of bone and soft tissue tumours: hints and hazards

Although the diagnostic algorithm of a suspected bone or soft tissue tumour, as well as the biopsy itself, are well defined, avoidable errors still happen. Major flaws might lead to unnecessary tissue contamination resulting in amputations or recurrences. In the current review we will focus in particular on biopsy guidelines and possible biopsy-related problems such as haematomas, sampling errors, and postoperative fractures. Finally, we will provide ten simple rules for a successful biopsy.