What is the association between gender and self-perceived health status when controlling for disease-specific conditions? A retrospective data analysis of pre- and post-operative EQ-5D-5L differences in total hip and knee arthroplasty

BACKGROUND

The self-perceived health status of patients undergoing total hip and knee arthroplasty (THA and TKA) might differ post-operatively due to gender, age, or comorbidities. Patient-reported outcome measures (PROMs) such as the EQ-5D-5L measure the self-perceived health status. This study investigates whether the index score of the EQ-5D-5L is a valid tool for interpreting gender differences in outcomes for patients undergoing THA and TKA.

METHODS

Routine and PROM-data of elective primary THA or TKA patients in two German hospitals between 2016 and 2018 were analyzed. Univariate analysis with Pearson's chi-square was conducted to identify control variables for gender. To quantify the association between gender and the EQ-5D-5L dimensions, a cumulative odds ordinal logistic regression with proportional odds was conducted.

RESULTS

Two thousand three hundred sixty-eight​​ THA patients (m = 978; f = 1390) and 1629 TKA patients (m = 715; f = 914) were considered. The regression analysis of the individual EQ-5D-5L dimensions showed that female gender was significantly associated with better self-care (THA and TKA) and better post-operative mobility (THA). In contrast, male gender was significantly associated with less pain/discomfort (TKA) and less anxiety/depression (THA) pre-surgery and 3-months post-surgery.

CONCLUSION

Our results confirmed that the self-perceived health status improved after surgery. However, due to the different associations of gender to the individual dimensions of the EQ-5D-5L, the weighted index score clouds the comparability between patients with different gender undergoing THA or TKA. Therefore, we argue to use the individual five dimensions for health status analysis, to reveal relevant additional information.

Thresholds for meaningful improvement in WOMAC scores need to be adjusted to patient characteristics after hip and knee replacement

PURPOSE

To calculate unstratified and patient-specific meaningful improvement (MI) and patient acceptable symptom states (PASS) for the WOMAC total score in patients after total hip (THR) or total knee replacement (TKR).

METHODS

A retrospective observational cohort study. Anchor-based receiver operator characteristics curves were used to estimate MI and PASS thresholds.

RESULTS

Recovery paths were specific to individual characteristics of patients. An unstratified 12-months MI threshold of 28.1 (PASS: 13.3) and 17.8 (PASS: 15.8) for patients after THR and TKR, respectively, would unfairly detect critical recovery paths.

CONCLUSIONS

Thresholds for treatment success need to be as patient-specific as possible.

Cervical Single-Level Pincer Stenosis Causing Myelopathy: A Technical Note and Medium-term Results of a One-Session Microsurgical 360-Degree Treatment

BACKGROUND AND STUDY AIMS

 Single-level circumferential or pincer stenosis (PS) affects few patients with degenerative cervical myelopathy (DCM). The surgical technique and medium-term results of a one-session microsurgical 360-degree (m360°) procedure are presented.

PATIENTS

 Between 2013 and 2018, the data of 23 patients were prospectively collected out of 371 patients with DCM. The m360° procedure comprised a microsurgical anterior cervical decompression and fusion (ACDF), with additional plate fixation, followed by flipping the patient and performing a microsurgical posterior bilateral decompression via a unilateral approach in crossover technique.

RESULTS

 The mean age of the patients was 72 years (range: 50-84); 17 patients were males. The mean follow-up time was 12 months (range: 6-31). The patients filled in the patient-derived modified Japanese Orthopaedic Association (P-mJOA) questionnaire on average 53 months after surgery. One patient received a two-level ACDF. Lesions were mostly (92%) located at the C3/C4 (8/24), C4/C5 (7/24), and C5/C6 (7/24) levels. Functional X-rays showed segmental instability in 10 of 23 patients (44%). All preoperative T2-weighted magnetic resonance imaging (MRI) showed an intramedullary hyperintensity. The median preoperative mJOA score was 13 (range 3), and it improved to 16 (range 3) postoperatively. The mean improvement rate in the mJOA score was 73%. When available, postoperative MRI confirmed good circumferential decompression with persistent intramedullary hyperintensity. There were two complications: a long-lasting radicular paresthesia at C6 and a transient C5 palsy. No revision surgery was required.

CONCLUSION

 The one-session m360° procedure was found to be a safe surgical procedure for the treatment of PS, and the medium-term clinical outcome was satisfactory.

Participation in a Preoperative Patient Education Session Is a Significant Predictor of Better WOMAC Total Index Score and Higher EQ-5D-5L Health Status Index 1 Year After Total Knee and Hip Arthroplasties: A Retrospective Observational Study

OBJECTIVE

The aim of the study was to investigate whether patient-specific factors, preoperative patient-reported outcome measures, and participation in a preoperative patient education session significantly predict 1-yr Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) total score and EuroQol 5 Dimensions 5 Levels (EQ-5D-5L) health status index of patients who underwent total hip or knee arthroplasties within an enhanced rehabilitation program.

DESIGN

This is a retrospective observational cohort study. The inclusion criteria were met by 676 (373 total hip arthroplasties and 303 total knee arthroplasties) patients. Two multiple regression models were carried out to estimate the contributions of nine potential predictors.

RESULTS

Younger age (P = 0.006), higher preoperative EQ-5D-5L index (P = 0.004), lower patient clinical complexity level (P = 0.001), lower preoperative WOMAC total score (P < 0.001), preoperative patient education session (P = 0.004), and submitting for total hip arthroplasty (P < 0.001) were significant predictors of better 1-yr WOMAC total score. Higher preoperative EQ-5D-5L index (P < 0.001), lower patient clinical complexity level classification (P < 0.001), lower preoperative WOMAC total score (P = 0.009), preoperative patient education session (P = 0.04), and submitting for total hip arthroplasty (P = 0.01) were significant predictors of higher 1-yr EQ-5D-5L health status index.

CONCLUSIONS

Better baseline patient-reported outcome measure scores, less comorbidities, younger age, submitting for total hip arthroplasty, and attending a preoperative patient education session were significant predictors of better WOMAC total scores and higher EQ-5D-5L health status index 1 yr after total hip or total knee arthroplasties.

P–042 Impact of semen parameters, sperm DNA fragmentation and sperm aneuploidy in male infertility

Study question

Should sperm aneuploidies and sperm DNA fragmentation (sDNAfrag) be included as valid tests in the routine investigation of male infertility?

Summary answer

Sperm DNA fragmentation was associated with male age, oligozoospermia (OZ), oligoteratozoospermia (OT), astenoteratozoospermia (AT) and oligoastenoteratozoospermia (OAT). Sperm aneuploidies were associated with OT and OAT.

What is known already

Semen parameters assist male infertility diagnosis and treatment, but sDNAfrag and aneuploidy analysis could add useful information, as abnormal values compromise fertility. To include these tests in the routine diagnosis it should be determined if behave as informative parameter and add information regarding the fertility status. For that, further studies comparing these tests to semen parameters are needed, since previous results are not consensual. Additionally, standardization of a sDNAfrag cut-off is needed, as different sample sizes and techniques originate distinct results. Also, until a standardization of the protocol is missing, a cut-off value should be defined for each laboratory.

Study design, size, duration

A retrospective and prospective investigation was performed, within a 12 years period (April 2007-December 2019). A total of 835 infertile males with a normal karyotype (46,XY) were included. Karyotyping and evaluation of sDNAfrag and sperm aneuploidies were made at a public Genetic unit. All normozoospermic (NZ) patients with a born child and patients whose infertility treatments were done due to female factors were selected from our database and used as controls (60 individuals).

Participants/materials, setting, methods

Semen analysis followed WHO–2010 guidelines. sDNAfrag was evaluated using the TUNEL assay. Sperm aneuploidies were detected using FISH (chromosomes 13, 18, 21, X, Y). Several tests were applied: correlations for linear associations between numerical variables, ANOVA for comparisons between means, Dunn-test for post-hoc comparisons. To determine the sDNAfrag cut-off value, the area under the ROC curve, sensitivity and specificity, were calculated, with the Youden-Index used to find a threshold that maximizes both sensitivity and specificity.

Main results and the role of chance

Regarding male age, it was observed a positive correlation with sperm concentration, a negative correlation with sperm vitality (VT) and hypoosmolality, and a positive correlation with sDNAfrag. Regarding sDNAfrag, it was observed negative correlation with sperm concentration, total progressive motility (TPM), morphology, VT and hypoosmolality. Regarding sperm aneuploidies, both total sperm aneuploidy and total sperm disomy exhibited a negative association with sperm concentration, TPM and morphology. It was also investigated whose groups of individuals could be indicated for sDNAfrag or sperm aneuploidy testing. The NZ group evidenced significant lower sDNAfrag, total sperm aneuploidy and total sperm disomy in relation to the non-NZ group. In the NZ group, sDNAfrag was significantly lower in relation to the OZ, OT, AT and OAT groups. The NZ group presented significant lower percentages of sperm aneuploidy in relation to the OT and OAT groups, and significant lower percentages of sperm disomy in relation to the OAT group. Additionally, sDNAfrag was positively correlated with total sperm aneuploidy and total sperm disomy. From the present large population, ROC curve analysis allowed estimating a cut-off value of 18.8% for the TUNEL-assay (sDNAfrag), with 0.658 of area under the curve, 53.9% sensitivity and 76.7% specificity.

Limitations, reasons for caution

Although presenting a high number of cases and strict controls, the present study was unable to include as controls healthy men with proven fertility. Additionally, the present study did not take into account life-style factors and male associated pathologies besides infertility.

Wider implications of the findings: Semen parameters were shown to be negatively correlated with sDNAfrag and sperm aneuploidies. As sDNAfrag testing and sperm aneuploidy testing were associated with semen abnormalities and male age, it is suggested their inclusion in the routine evaluation of infertile men, thus adding important complementary information about the fertility status.

Trial registration number

Not Appliable

TKA patients experience less improvement than THA patients at 3 and 12 months after surgery. A retrospective observational cohort study

PURPOSE

To investigate whether WOMAC scores changes after THA or TKA are gender and joint specific.

METHODS

Retrospective cohort study. The data of 855 THA and 684 TKA patients were analyzed.

RESULTS

Follow-up time (p < 0.001), gender (p < 0.001), joint (p < 0.001), and interaction FU by joint (p < 0.001) had significant effects on WOMAC total and sub-scores. Patients after TKA perceived less improvement in all dimensions in comparison to THA patients (p < 0.001).

CONCLUSION

WOMAC score changes after THA or TKA are joint-specific. Patients after TKA perceived less improvement. These results can be used to adjust patients' expectations.

The prevalence of redundant nerve roots in patients with lumbar spinal stenosis is body position dependent: a retrospective observational study with repeated measures design in an upright MRI scanner

Purpose

Redundant nerve roots (RNRs) are a negative prognostic factor in patients with central lumbar spinal stenosis (LSS). Forty percent of candidates for surgical decompression show RNRs (RNR+) on preoperative conventional magnetic resonance imaging (MRI). We investigated the prevalence of RNRs in three functional postures (standing, neutral sitting and flexed sitting) with an upright MRI (upMRI).

Methods

A retrospective observational study with a repeated measures design. Thirty surgical candidates underwent upMRI. Sagittal and axial T2-weighted images of the three functional postures were evaluated. The segmental length of the lumbar spine (sLLS), the lordotic angle (LA) and the dural cross-sectional area (DCSA) were measured in each body position. Generalized linear mixed models were carried out. The 0.05 level of probability was set as the criterion for statistical significance.

Results

The prevalence of RNRs decreased from 80% during standing to 16.7% during flexed sitting (p < 0.001). The sLLS increased significantly from standing to neutral sitting in both RNR groups (p < 0.001). The increase from neutral sitting to flexed sitting was only significant (p < 0.001) for the group without RNRs (RNR−). The LA decreased significantly for both RNR groups from standing to flexed sitting (p < 0.001). The DSCA increased significantly in the RNR− group (p < 0.001) but not in the RNR+ group (p = 0.9).

Conclusion

The prevalence of RNRs is body position dependent. Increases in DCSA play a determinant role in resolving RNRs.

Sensor Positioning Influences the Accuracy of Knee Rom Data of an E-Rehabilitation System: A Preliminary Study with Healthy Subjects

E-rehabilitation is the term used to define medical rehabilitation programs that are implemented at home with the use of information and communication technologies. The aim was to test whether sensor position and the sitting position of the patient influence the accuracy of knee range of movement (ROM) data displayed by the BPMpathway e-rehabilitation system. A preliminary study was conducted in a laboratory setting with healthy adults. Knee ROM data was measured with the BPMpathway e-rehabilitation system and simultaneously with a BIOPAC twin-axis digital goniometer. The main outcome was the root mean squared error (RMSE). A 20% increase or reduction in sitting height led to a RMSE increase. A ventral shift of the BPMpathway sensor by 45° and 90° caused significant measurement errors. A vertical shift was associated with a diminution of the measurement errors. The lowest RMSE (2.4°) was achieved when the sensor was placed below the knee. The knee ROM data measured by the BPMpathway system is comparable to the data of the concurrent system, provided the instructions of the manufacturer are respected concerning the sitting position of the subject for knee exercises, and disregarding the same instructions for sensor positioning, by placing the sensor directly below the knee.

Redundant nerve roots in lumbar spinal stenosis: inter- and intra-rater reliability of an MRI-based classification

Purpose

Patients with central lumbar spinal stenosis (LSS) have a longer symptom history, more severe stenosis, and worse postoperative outcomes, when redundant nerve roots (RNRs) are evident in the preoperative MRI. The objective was to test the inter- and intra-rater reliability of an MRI-based classification for RNR.

Methods

This is a retrospective reliability study. A neuroradiologist, an orthopedic surgeon, a neurosurgeon, and three orthopedic surgeons in-training classified RNR on 126 preoperative MRIs of patients with LSS admitted for microsurgical decompression. On sagittal and axial T2-weighted images, the following four categories were classified: allocation (A) of the key stenotic level, shape (S), extension (E), and direction (D) of the RNR. A second read with cases ordered differently was performed 4 weeks later. Fleiss and Cohen’s kappa procedures were used to determine reliability.

Results

The allocation, shape, extension, and direction (ASED) classification showed moderate to almost perfect inter-rater reliability, with kappa values (95% CI) of 0.86 (0.83, 0.90), 0.62 (0.57, 0.66), 0.56 (0.51, 0.60), and 0.66 (0.63, 0.70) for allocation, shape, extension, and direction, respectively. Intra-rater reliability was almost perfect, with kappa values of 0.90 (0.88, 0.92), 0.86 (0.84, 0.88), and 0.84 (0.81, 0.87) for shape, extension, and direction, respectively. Intra-rater kappa values were similar for junior and senior raters. Kappa values for inter-rater reliability were similar between the first and second reads (p = 0.06) among junior raters and improved among senior raters (p = 0.008).

Conclusions

The MRI-based classification of RNR showed moderate-to-almost perfect inter-rater and almost perfect intra-rater reliability.

Patient demographics and MRI-based measurements predict redundant nerve roots in lumbar spinal stenosis: a retrospective database cohort comparison

Background

Up to 40% of patients diagnosed with lumbar spinal stenosis (LSS) show evidence of redundant nerve roots (RNR) of the cauda equina on their magnetic resonance images (MRI). The etiology of RNR is still unclear. Preoperative evidence of RNR is associated with a worse postsurgical outcome. Consequently, potential predictors of RNR could have a prognostic value. The aim was to test whether patient demographics and MRI-based measurements can predict RNR in LSS patients.

Methods

In a retrospective database-based cohort study the preoperative data of 300 patients, 150 with (RNR+) and 150 without (RNR-) evidence of RNR on their MRI were analyzed. Three independent researchers performed the MRI reads. Potential predictors were age, gender, body height (BH), length of lumbar spine (LLS), segmental length of lumbar spine (SLLS), lumbar spine alignment deviation (LSAD), relative LLS (rLLS), relative SLLS (rSLLS), number of stenotic levels (LSS-level), and grade of LSS severity (LLS-grade, increasing from A to D). Binomial logistic regression models were performed.

Results

RNR+ patients were 2.6 years older (p = 0.01). Weak RNR+ predictors were a two-years age increase (OR 1.06; p = 0.02), 3 cm BH decrease (OR 1.09; p = 0.01) and a 5 mm SLLS decrease (OR 1.34; p < 0.001). Strong RNR+ predictors were a 1% rLLS decrease (OR 2.17; p < 0.001), LSS-level ≥ 2 (OR 2.59; p = 0.001), LLS-grade C (OR 5.86; p = 0.02) and LLS-grade D (OR 18.4; p < 0.001). The mean rSLLS of RNR+ patients was 0.6% shorter (p < 0.001; 95% C.I. 0.4 to 0.8) indicating a disproportionate shorter lumbar spine.

Conclusions

We identified LSS severity grade and LSS levels as the strongest predictors of RNR. In addition to previous studies, we conclude that a shortened lumbar spine by degeneration is involved in the development of RNR.

Intra- and Inter-rater Reliability of Navigated Ultrasound in the Assessment of Pelvic Tilt in Symptom-Free Young Adults

OBJECTIVES

Pelvic tilt is the angle between the anterior pelvic plane and the coronal plane. It affects cup positioning in total hip arthroplasty. The primary objective of this study was to test the intra- and inter-rater reliability of a navigated smart device-based ultrasound system for pelvic tilt assessment. The secondary objective was to test the inter-rater variability of the measurements on a hip phantom.

METHODS

A repeated-measures design was used. Two raters measured the pelvic tilt of 12 symptom-free young adults in upright and supine positions. Additionally, pelvic tilt was measured on a hip phantom. Each rater performed 3 measurements in each body position on the participants and 12 measurements on the hip phantom. Intra- and inter-rater reliability were calculated with the use of intraclass correlation coefficients. The variability in measurements on the hip phantom was assessed by a Bland-Altman analysis of agreement.

RESULTS

Intraclass correlation coefficient 95% confidence intervals for intra-rater reliability ranged from good to excellent and moderate to excellent for the supine and upright positions respectively. Intraclass correlation coefficient 95% confidence intervals for inter-rater reliability ranged from poor to excellent for both positions. Hip phantom measurements showed no significant average bias (P > .05) and no significant proportional bias (P > .05). The 95% inter-rater limits of agreement were ±1.3° and ±1.7° for the supine and upright positions, respectively.

CONCLUSIONS

The intra-rater reliability values achieved were suitable. Intraclass correlation coefficient values for inter-rater reliability remained below an acceptable level. Possible reasons and overcoming strategies were presented. The 95% limits of agreement were good, at less than ±2°.

Pelvic Tilt Angle Differences Between Symptom-Free Young Subjects and Elderly Patients Scheduled for THA: The Rationale for Tilt-Adjusted Acetabular Cup Implantation

Background:

The question whether Pelvic Tilt (PT) angles measured in the supine position are adequate for the alignment of the acetabular cup without an adjustment for anatomical differences between patients is of clinical importance. The aim of this work was to test for factors that can significantly affect PT angles.

Methods:

In the present retrospective cohort comparison, the PT angles of 12 Symptom-Free Young Subjects (SFYS) and 45 patients scheduled for Total Hip Arthroplasty (THA) were compared. The data was collected during two studies with the use of a novel smartphone-based navigated ultrasound measurement system. Multi-factorial analysis of variance was run to determine which factors significantly affect PT.

Results:

Body position (F= 126.65; P< 0.001) and group (SFYS vs. THA patients) (F= 17.52; P< 0.001) had significant main effects on PT. There was also a significant interaction between body position and group (F= 25.59; P< 0.001). The mean PT increased by 8.1° from an interiorly to a neutral tilted position (P< 0.001) and 21.4° from a neutral to a posteriorly tilted position (P< 0.001) with the transition from the supine into the upright position for the SFYS and THA patients, respectively.

Conclusion:

In both groups, PT changed significantly with a transition from the supine to the upright position. A position-dependent mean PT increase in the patient group showed that acetabular cup alignment based on PT in the supine position is not reliable without taking into consideration the inclination of the pelvis in standing position. This may lead to instability and dislocations.

DNA methylation imprinting errors in spermatogenic cells from maturation arrest azoospermic patients

Imprinting errors have been described in spermatozoa from infertile patients with oligozoospermia and azoospermia. However, little is known about methylation of imprinted genes in other spermatogenic cells from azoospermic patients. Therefore, we aimed to evaluate the methylation status of single CpGs located in the differentially methylated regions (DMRs) of two imprinted genes, one paternally (H19) and one maternally (MEST) methylated, in primary spermatocytes of azoospermic patients presenting complete (MAc, n = 7) and incomplete (MAi, n = 8) maturation arrest, as well as in other spermatogenic cells from MAi patients that presented focus of complete spermatogenesis in some seminiferous tubules. We observed H19 imprinting errors in primary spermatocytes from one MAi patient and MEST imprinting errors in one MAi and two MAc patients. Additionally, H19 imprinting errors were observed in elongated spermatids/spermatozoa from one MAi patient. Nevertheless, no statistical differences were found for H19 and MEST global methylation levels (percentage of methylated and unmethylated CpGs, respectively) between patients with complete and incomplete MA and also between MA groups and a control group. These results provide further evidence that imprinting errors occur in spermatogenic cells from patients presenting impaired spermatogenesis, as we and others have previously described in ejaculated and testicular spermatozoa. As paternal imprinting errors can be transmitted to the embryo by the sperm cell, they can provide a possible explanation for poor embryo development and/or low pregnancy rates as correct expression of imprinted genes is crucial for embryo and placental development and function. Therefore, in cases with male factor infertility where unsuccessful in vitro fertilization (IVF) treatments are recurrent, analysis of imprinting marks in spermatozoa might be a useful diagnostic tool.

Patient-specific and intra-operatively modifiable factors assessed by computer navigation predict maximal knee flexion one year after TKA

PURPOSE

There are multiple factors affecting maximal knee flexion (MKF) after total knee arthroplasty (TKA). The aim of the study was to investigate whether patient-specific factors (PSF) and surgically modifiable factors (SMF), measured by means of a computer-assisted navigation system, can predict the MKF after TKA.

METHODS

Data from 99 patients collected during a randomized clinical trial were used for this secondary data analysis. The MKF of the patients was measured preoperatively and 1-year post-surgery. Multiple regression analyses were performed to investigate which combination of variables would be the best to predict the 1-year MKF.

RESULTS

When considering SMF alone, the combination of three factors significantly predicted the 1-year MKF (p = 0.001), explaining 22 % of its variation. When considering only PSF, the combination of pre-op MKF and BMI significantly predicted the 1-year MKF (p < 0.001), explaining 23 % of its variation. When considering both groups of potential predictors simultaneously, the combination of five SMF with two PSF significantly predicted the 1-year MKF (p = 0.001), explaining 32 % of its variation.

CONCLUSIONS

Computer navigation variables alone could explain 22 % of the variance in the 1-year MKF. The larger proportion (32 %) of the 1-year MKF variation could be explained with a combination of SMF and PSF. The results of studies in this area could be used to identify patients at risk of poor outcomes.

LEVEL OF EVIDENCE

Level II, Prognostic study.

Do Well-Balanced Primary TKA Patients Achieve Better Outcomes Within the First Year After Surgery?

Some surgically modifiable factors are related to soft tissue balance. With computer-assisted surgery, it is possible to access these variables quantitatively. The aim of this analysis was to study the influence of gap balance on clinical outcomes within the first year after computer-navigated total knee arthroplasty (TKA). Based on navigation data, 3 independent variables reflecting gap balance were used to split the patients in 2 groups. The Knee Society Scores (Function [KSS-F] and Knee [KSS-K]) and the maximal knee flexion (MKF) measured preoperatively and at 3, 6 and 12 months were compared using analyses of variance (2×4 design) for repeated measures. Higher flexion-extension gap equality led to statistically higher KSS-F and KSS-K scores at 1 year (P=.02). Higher medial-lateral flexion gap equality led to superior mean MKF at all measurement points; however the differences were statistically only significant at 3 months (P=.01). The coefficients of variation of the variables used to select the patients were overall very low. With computer-assisted navigation, it is possible to access quantitatively the size of the medial and lateral flexion and extension gaps. Higher flexion-extension gap equality values led to statistically significant better KSS-F and KSS-K scores at 1 year. Higher medial-lateral flexion gap equality values led to better MKF values; however the differences were only statistically significant at 3 months. [Orthopedics. 2016; 39(3):S6-S12.].

Surgically modifiable factors measured by computer-navigation together with patient-specific factors predict knee society score after total knee arthroplasty

BACKGROUND

The purpose was to investigate whether patient-specific factors (PSF) and surgically modifiable factors (SMF), measured by means of a computer-assisted navigation system, can predict the Knee Society Scores (KSS) after total knee arthroplasty (TKA).

METHODS

Data from 99 patients collected during a randomized clinical trial were used for this secondary data analysis. The KSS scores of the patients were measured preoperatively and at 4-years follow-up. Multiple regression analyses were performed to investigate which combination of variables would be the best to predict the 4-years KSS scores.

RESULTS

When considering SMF alone the combination of four of them significantly predicted the 4-years KSS-F score (p = 0.009), explaining 18 % of its variation. When considering only PSF the combination of age and body weight significantly predicted the 4-years KSS-F (p = 0.008), explaining 11 % of its variation. When considering both groups of predictors simultaneously the combination of three PSF and two SMF significantly predicted the 4-years KSS-F (p = 0.007), explaining 20 % of its variation.

CONCLUSIONS

Younger age, better preoperative KSS-F scores and lower BMI before surgery, a positive tibial component slope and small changes in femoral offset were predictors of better KSS-F scores at 4-years.

No differences in clinical outcomes between fixed- and mobile-bearing computer-assisted total knee arthroplasties and no correlations between navigation data and clinical scores

PURPOSE

The theoretical advantages of mobile-bearing (MB) designs over the conventional fixed bearings (FBs) for total knee arthroplasty (TKA) have not been proved yet through clinical studies. The aim of the study was to test whether the MB design has advantages in terms of better clinical outcomes when compared to FB. Furthermore, the relationships between intra-operative obtained implant positioning data and the clinical scores were analysed.

METHODS

A total of 99 patients were randomized into the FB or the MB group. All patients received the same posterior cruciate retaining implants and were operated with the use of a computer-assisted navigation system. The clinical outcomes of both groups were compared pre-operatively, at 1 year, and at a mean follow-up time of 4 years after surgery.

RESULTS

The MB implants showed no advantages over the FB when comparing the Knee Society Scores, the Oxford Score, the range of movement (ROM) and pain intensity of the patients in both groups at 1 and 4 years after surgery. There were no relationships between the computer navigation data and the clinical scores.

CONCLUSIONS

In view of the 4-year results, there is no evidence to support the recommendation of one design over the other in terms of better clinical outcome scores, higher ROM or lower pain rates. Long-term follow-up results may be necessary, including survival rates. Further research comparing different TKA designs should also include standardized performance-based tests.

LEVEL OF EVIDENCE

Prospective study (Randomized controlled trial with adequate statistical power to detect differences), Level I.

Abnormal methylation of imprinted genes in human sperm is associated with oligozoospermia

Genomic imprinting marks in the male germ line are already established in the adult germinal stem cell population. We studied the methylation patterns of H19 and MEST imprinted genes in sperm of control and oligozoospermic patients, by bisulphite genomic sequencing. We here report that 7 out of 15 (46.7%) patients with a sperm count below 10 x 10(6)/ml display defective methylation of H19 and/or MEST imprinted genes. In these cases, hypomethylation was observed in 5.54% (1.2-8.3%) and complete unmethylation in 2.95% (0-5.9%) of H19 clones. Similarly, for the CTCF-binding site 6, hypomethylation occurred in 4.8% (1.2-8.9%) and complete unmethylation in 3.7% (0-6.9%) of the clones. Conversely, hypermethylation occurred in 8.3% (3.8-12.2%) and complete methylation in 6.1% (3.8-7.6%) of MEST clones. Of the seven patients presenting imprinting errors, two had both H19 hypomethylation and MEST hypermethylation, whereas five displayed only one imprinted gene affected. The frequency of patients with MEST hypermethylation was highest in the severe oligozoospermia group (2/5 patients), whereas H19 hypomethylation was more frequent in the moderate oligozoospermia (2/5 patients). In all cases, global sperm genome methylation analysis (LINE1 transposon) suggested that defects were specific for imprinted genes. These findings could contribute to an explanation of the cause of Silver-Russell syndrome in children born with H19 hypomethylation after assisted reproductive technologies (ART). Additionally, unmethylation of the CTCF-binding site could lead to inactivation of the paternal IGF2 gene, and be linked to decreased embryo quality and birth weight, often associated with ART.

AZF and DAZ gene copy-specific deletion analysis in maturation arrest and Sertoli cell-only syndrome

Deletions of the AZFc region in Yq11.2, which include the DAZ gene family, are responsible for most cases of male infertility and were associated with severe oligozoospermia and also with a variable testicular pathology. To uncover the functional contribution of DAZ to human spermatogenesis, a DAZ gene copy-specific deletion analysis was previously established and showed that DAZ1/DAZ2 deletions associate with oligozoospermia. In this study we applied the same screening method to 50 control fertile males and 91 non-obstructive azoospermic males, 39 with Sertoli cell-only syndrome (SCOS) and 52 with meiotic arrest (MA). Samples were also screened with 24 sequence-tagged sites to the different AZF regions, including 114 control fertile males. After biopsy (testicular sperm extraction, TESE), residual spermiogenesis was found in 57.7% MA and 30.8% SCOS cases (incomplete syndromes). DAZ1/DAZ2 deletions were associated with the testicular phenotype of residual spermiogenesis as they were only found in two patients (8%) with incomplete MA. Differences between incomplete (23.3%) and complete (4.5%) MA cases regarding AZFc and DAZ1/DAZ2 deletion frequencies, and between incomplete (58.3%) and complete (11.1%) SCOS cases for AZFc deletions, suggest that incomplete syndromes might represent an aggravation of the oligozoospermic phenotype. As successful TESE was achieved in 87.5% of MA cases with AZFc and DAZ1/DAZ2 deletions and in 58.3% of SCOS cases with AZFc deletions, the present results also suggest that these molecular markers might be used for the establishment of a prognosis before TESE.