Custom-made implants for massive acetabular bone loss: accuracy with CT assessment

BACKGROUND

Custom-made implants are a valid option in revision total hip arthroplasty to address massive acetabular bone loss. The aim of this study was to assess the accuracy of custom-made acetabular implants between preoperative planning and postoperative positioning using CT scans.

METHODS

In a retrospective analysis, three patients who underwent an acetabular custom-made prosthesis were identified. The custom-made designs were planned through 3D CT analysis considering surgical points of attention. The accuracy of intended implants positioning was assessed by comparing pre- and postoperative CT analyzing the center of rotation (CoR), anteversion, inclination, screws, and implant surface in contact with the bone.

RESULTS

The three cases presented satisfactory accuracy in positioning. A malpositioning in the third case was observed due to the posterization of the CoR of the implant of more than 10 mm. The other CoR vectors considered in the third patient and all vectors in the other two cases fall within 10 mm. All the cases were positioned with a difference of less than 10° of anteversion and inclination with respect to the planning.

CONCLUSIONS

The current case series revealed promising accuracy in the positioning of custom-made acetabular prosthesis comparing the planned implant in preoperative CT with postoperative CT.

Parameters influencing renal response to SGLT2 inhibitors and GLP1 receptor agonists in type 2 diabetes patients with preserved renal function: a comparative, prospective study

PURPOSE

SGLT2 inhibitors (SGLT2i) and GLP1 receptor agonists (GLP1-RA) protect the kidney in type 2 diabetes (T2DM) subjects. The role of patient's phenotype years before starting the treatment in determining the kidney response to these drugs has never been evaluated.

SUBJECTS AND METHODS

Clinical and biochemical parameters were collected in 92 T2DM patients with preserved kidney function from year -4 (T-4) to year +3 (T+3) from the introduction of semaglutide or empagliflozin (T0). Glomerular filtration rate (eGFR) slopes were evaluated to identify eGFR changes (ΔGFR) and predictors of treatment response. Urinary markers of kidney impairment were measured at T0, including KIM-1, TNFR1 and L-FABP.

RESULTS

Characteristics of patients on semaglutide (n = 46) or empagliflozin (n = 37) were similar at T-4 and T0. ΔGFR from T0 to T+3 was -5.5 [-10.0; -0.7] vs -2.6 [-102.4] ml/min/1.73 m² for GLP1-RA and SGLT2i, respectively (p = ns). Compared with patients with a slower eGFR decline, those with ΔGFR > 5 ml/min/1.73 m² from T0 to T+3 (49%) or ΔGFR > 10 ml/min/1.73 m² from T-4 to T+3 (25%) had similar characteristics and urinary markers at T-4 and T0. The latter group showed greater eGFR decline from T-3 to T0, which tended to be delayed more by SGLT2i than GLP1-RA (p = 0.09).

CONCLUSION

In our cohort, subjects with T2DM and preserved renal function show similar eGFR response to treatment with GLP1-RA or SGLT2i. Baseline urinary biomarkers or prior phenotyping do not predict treatment response. An early eGFR decline identifies patients prone to lose more eGFR over time, who may benefit more from SGLT2i treatment.

Tricalcium Phosphate as a Bone Substitute to Treat Massive Acetabular Bone Defects in Hip Revision Surgery: A Systematic Review and Initial Clinical Experience with 11 Cases

The use of tricalcium phosphate (TCP) as a bone substitute is gaining increasing interest to treat severe acetabular bone defects in revision total hip arthroplasty (rTHA). The aim of this study was to investigate the evidence regarding the efficacy of this material. A systematic review of the literature was performed according to the PRISMA and Cochrane guidelines. The study quality was assessed using the modified Coleman Methodology Score (mCMS) for all studies. A total of eight clinical studies (230 patients) were identified: six on TCP used as biphasic ceramics composed of TCP and hydroxyapatite (HA), and two as pure-phase ceramics consisting of TCP. The literature analysis showed eight retrospective case series, of which only two were comparative studies. The mCMS showed an overall poor methodology (mean score 39.5). While the number of studies and their methodology are still limited, the available evidence suggests safety and overall promising results. A total of 11 cases that underwent rTHA with a pure-phase ceramic presented satisfactory clinical and radiological outcomes at initial short-term follow-up. Further studies at long-term follow-up, involving a larger number of patients, are needed before drawing more definitive conclusions on the potential of TCP for the treatment of patients who undergo rTHA.

Orthobiologic Injections for the Treatment of Hip Osteoarthritis: A Systematic Review

The use of orthobiologics is gaining increasing interest as a minimally invasive treatment for hip osteoarthritis (OA). The aim of this study was to investigate the evidence about the safety and efficacy of these products. A systematic review of the literature was performed according to the PRISMA and Cochrane guidelines. The study quality was assessed using the RoB 2.0 for randomized controlled trials (RCTs) and the modified Coleman Methodology Score (mCMS) for all studies. A total of 20 clinical studies (735 patients) was identified, 12 on PRP injections and eight on cell-based therapies (five from bone marrow, two from adipose tissue, and one from amniotic fluid). The publication trend increased over time, with over 50% of articles published from 2019. The literature analysis showed only six RCTs, all on PRP injections. The mCMS showed an overall fair methodology (mean score 59.4). While the number of studies and their methodology are still limited, the available evidence suggests safety and overall promising results, with the treatment success being inversely proportional to the severity of OA. Further high-level controlled trials are needed before drawing more definitive conclusions on the real potential of orthobiologics for the injective treatment of patients affected by hip OA.

Patient-Reported and Quantitative Outcomes of Anatomic Anterior Cruciate Ligament Reconstruction With Hamstring Tendon Autografts

Background:

The pivot-shift test has become more consistent and reliable and is a meaningful outcome measurement after anterior cruciate ligament reconstruction (ACLR).

Purpose/Hypothesis:

The purpose of this investigation was to assess patient-reported outcomes (PROs) and the quantitative pivot shift (QPS) preoperatively, at time zero immediately after anatomic ACLR, and after 24 months as well as the relationship between PROs and the QPS. It was hypothesized that anatomic ACLR would restore rotatory stability measured by the pivot-shift test and that QPS measurements would be positively correlated with PROs.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

The ACL-injured and contralateral uninjured knees from 89 of 107 (83.2%) enrolled patients at 4 international centers were evaluated using a standardized pivot-shift test. Tibial acceleration was assessed with an inertial sensor, and lateral compartment translation was measured using an image analysis system preoperatively, at time zero immediately postoperatively, and at follow-up after 2 years. PROs were assessed at 12 and 24 months postoperatively with the International Knee Documentation Committee (IKDC) subjective knee form, Cincinnati Knee Rating System (CKRS), Marx activity rating scale, and activity of daily living score (ADLS).

Results:

The mean patient age at surgery was 27 years (range, 15-45 years). A positive pivot shift preoperatively (side-to-side difference in tibial acceleration, 2.6 ± 4.0 m/s²; side-to-side difference in anterior tibial translation, 2.0 ± 2.0 mm) was reduced at time zero postoperatively (side-to-side difference in tibial acceleration, –0.5 ± 1.3 m/s²; side-to-side difference in anterior tibial translation, –0.1 ± 1.0 mm). All PROs improved from preoperatively to final follow-up at 24 months: from 56.5 to 85.5 points for the IKDC (P = .0001), from 28.8 to 32.4 points for the CKRS (P = .04), from 11.2 to 7.9 points for the Marx (P < .0001), and from 75.7 to 91.6 points for the ADLS (P < .0001). Neither preoperative nor time zero postoperative rotatory laxity assessed by the pivot-shift test correlated with PROs at 24-month follow-up. A graft retear was observed in 4 patients (4.5%) within 2 years of follow-up.

Conclusion:

Anatomic ACLR resulted in significantly improved and acceptable PROs at 2-year follow-up and a low failure rate. Anatomic ACLR restored QPS measurements of anterior tibial translation and tibial acceleration to those of the contralateral knee immediately after surgery while still under anesthesia, but there was no correlation between the QPS preoperatively or at time zero after ACLR and PROs at 2-year follow-up.

The Contribution of Partial Meniscectomy to Preoperative Laxity and Laxity After Anatomic Single-Bundle Anterior Cruciate Ligament Reconstruction: In Vivo Kinematics With Navigation

BACKGROUND

Limited in vivo kinematic information exists on the effect of clinical-based partial medial and lateral meniscectomy in the context of anterior cruciate ligament (ACL) reconstruction.

HYPOTHESIS

In patients with ACL deficiency, partial medial meniscus removal increases the anteroposterior (AP) laxity with compared with those with intact menisci, while partial lateral meniscus removal increases dynamic laxity. In addition, greater postoperative laxity would be identified in patients with partial medial meniscectomy.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A total of 164 patients with ACL tears were included in the present study and divided into 4 groups according to the meniscus treatment they underwent: patients with partial lateral meniscectomy (LM group), patients with partial medial meniscectomy (MM group), patients with partial medial and lateral meniscectomy (MLM group), and patients with intact menisci who did not undergo any meniscus treatment (IM group). A further division in 2 new homogeneous groups was made based on the surgical technique: 46 had an isolated single-bundle anatomic ACL reconstruction (ACL group), while 13 underwent a combined single-bundle anatomic ACL reconstruction and partial medial meniscectomy (MM-ACL group). Standard clinical laxities (AP translation at 30° of knee flexion, AP translation at 90° of knee flexion) and pivot-shift (PS) tests were quantified before and after surgery by means of a surgical navigation system dedicated to kinematic assessment. The PS test was quantified through 3 different parameters: the anterior displacement of the lateral tibial compartment (lateral AP); the posterior acceleration of the lateral AP during tibial reduction (posterior acceleration); and finally, the area included by the lateral AP translation with respect to the flexion/extension angle (area).

RESULTS

In the ACL-deficient status, the MM group showed a significantly greater tibial translation compared with the IM group (P < .0001 for AP displacement at 30° [AP30] and 90° [AP90] of flexion) and the LM group (P = .002 for AP30 and P < .0001 for AP90). In the PS test, the area of LM group was significantly larger (57%; P = .0175) than the one of the IM group. After ACL reconstruction, AP translation at 30° was restored, while the AP90 remained significantly greater at 1.3 mm (P = .0262) in the MM-ACL group compared with those with intact menisci.

CONCLUSION

Before ACL reconstruction, partial medial meniscectomy increased AP laxity at 30° and 90° and lateral meniscectomy increased dynamic PS laxity with respect to intact menisci. Anatomic single-bundle ACL reconstruction decreased laxities, but a residual anterior translation of 1.3 mm at 90° remained in patients with partial medial meniscectomy, with respect to those with intact menisci.

ACL reconstruction with lateral plasty reduces translational and rotatory laxity compared to anatomical single bundle and non-anatomical double bundle surgery: An in vivo kinematic evaluation with navigation system

BACKGROUND

Significantly better stability may be achieved with a Single Bundle Lateral Plasty (SBLP) reconstruction compared with the Single Bundle (SB) and Double Bundle (DB) procedures.

METHODS

The study included 42 patients who underwent ACL reconstruction. Patients were randomly selected for one of the following surgical procedure defining three study groups: Single-Bundle-Lateral-Plasty, Single-Bundle and Double-Bundle procedures. Laxity evaluation was performed with an intraoperative navigation system. Lachman test (AP30), Drawer test (AP90), Varus-Valgus stress test at 0° and 30° knee flexion (VV0, VV30), Internal-External rotation (IE30, IE90), and pivot shift (PS) test are the clinical test executed for the laxity evaluation. Laxity reduction was defined as the difference between laxity before the fixation of the graft used for the reconstruction and the laxity just after its fixation.

FINDINGS

For all the analyzed surgical techniques, the pre-reconstruction laxity values were statistically higher (P < 0.05) than the post-reconstruction values for all the analyzed tests. The analysis of the Drawer test and Internal-External rotation at 30° and 90° of knee flexion, highlighted a significant difference at time zero after surgery among the three study groups. The results showed that the SBLP technique had the highest reduction values compared to SB (P_IE90 = 0.001) and DB (P_AP90 = 0.012; P_IE30 = 0.021; P_IE90 = 0.003) techniques.

INTERPRETATION

SBLP technique showed significantly superior results in terms of antero-posterior and internal-external laxity reduction at time-zero after ACL reconstruction.

Triaxial accelerometer can quantify the Lachman test similarly to standard arthrometers

PURPOSE

To assess the relationship between the KiRA triaxial accelerometer and the KT-1000 measurements in the intact, anterior cruciate ligament (ACL) deficient, and ACL reconstructed knee joint for the quantification of the Lachman test. Moreover, the intra- and inter-examiner repeatability of the KiRA device will be determined. It was hypothesized that the side-to-side difference of the anterior tibial translation as measured by the KiRA device would be equivalent to the one measured by the KT-1000 during the Lachman test.

METHODS

Sixty patients were divided into three groups and have been prospectively included in the present study. Group_A composed of 20 patients with a diagnosis of an isolated ACL tear. Group_B composed of 20 patients who underwent ACL reconstruction with a Single-Bundle Lateral Plasty (SBLP) technique with at least 20 years of follow-up. Group_C was the control group and included 20 patients with no history of ACL lesion. Lachman test has been performed at manual-maximum load on both sides, the involved and the contralateral and analyzed with the two different devices.

RESULTS

The KiRA device in terms of side-to-side difference resulted not statistically different from the measurement of the KT-1000 arthrometer for the three study groups (n.s): Group_A: (4 ± 2 mm KiRA, 4 ± 2 mm KT1000), Group_B: (4 ± 2 mm KiRA, 4 ± 2 mm KT-1000), Group_C: (4 ± 2 mm KiRA, 4 ± 2 mm KT-1000), an excellent intra- (ICC = 0.88-0.89) and inter-examiner (ICC = 0.79) agreement was found for KiRA measurements.

CONCLUSION

The KiRA (I+, Italy) device offers a valid method to quantify the Lacham test.

LEVEL OF EVIDENCE

II.

Patients With Failed Anterior Cruciate Ligament Reconstruction Have an Increased Posterior Lateral Tibial Plateau Slope: A Case-Controlled Study

PURPOSE

To compare knee anatomical parameters of patients with failed anterior cruciate ligament reconstruction (ACL-R) with those of a control group of sex-matched patients with successful ACL-R.

METHODS

Forty-three patients (34 male, 9 female) who experienced graft failure after ACL-R were enrolled in the failed group. These patients were matched to a control group of 43 patients who underwent primary ACL-R with a minimum follow-up of 24 months. On magnetic resonance imaging, the following parameters were evaluated: transepicondylar distance, lateral and medial femoral condyle widths, tibial plateau width, notch width index, and the ratio of width and height of the femoral notch, ratio between the height and depth of the lateral and medial femoral condyle, lateral and medial posterior tibial slopes, and anterior subluxation of the lateral and medial tibial plateau. Multivariate regression with backward elimination, including only the previously identified significant variables, defined the independent predictors for revision surgery.

RESULTS

The anatomical variables that were significantly different between the 2 study groups were lateral and medial posterior tibial slopes, anterior subluxation of the lateral and medial tibial plateau, medial tibial plateau width, lateral tibial plateau width, medial femoral condyle width, and transepicondylar distance; however, the multivariate regression analysis identified the lateral posterior tibial slope (LTPs), the anterior subluxation of the medial tibial plateau, and the medial femoral condyle width as significant independent predictors (P < .05). The LPTs had the highest coefficient and the highest sensitivity (88%) and specificity (84%) to identify failures when considering the optimal cutoff value of 7.4°.

CONCLUSIONS

Several anatomical parameters have been identified that differ significantly between patients with failed ACL-R and those without a documented failure. The most accurate predictor of ACL failure was an LTPs >7.4°, with a sensitivity of 88% and specificity of 84%. Surgeons should consider measuring LTPs during preoperative assessment of ACL-injured patients, and patients with values >7.4° should be considered at high risk of ACL-R failure.

LEVEL OF EVIDENCE

Level III retrospective prognostic trial.

Anterior cruciate ligament reconstruction with an all-epiphyseal "over-the-top" technique is safe and shows low rate of failure in skeletally immature athletes

PURPOSE

The aim of this study was to follow up, clinically and radiographically, skeletally immature patients who underwent ACL reconstruction with an all-epiphyseal "over-the-top" technique.

METHODS

Twenty athletes aged between 8 and 13 years were enrolled and retrospectively evaluated. The subjects underwent surgical ACL reconstruction between 2009 and 2013. The surgical technique consisted of a single-bundle all-epiphyseal ACL reconstruction with an extra-articular lateral tenodesis. The mean follow-up was 54 months [34-123] after surgery. Clinically, the patients were evaluated pre- and post-operatively with Lysholm and KOOS scores; sport activity level was evaluated using the pre-injury, pre-operative and post-operative Tegner scores. Objective IKDC was calculated post-operatively. The joint laxity was evaluated by KT1000 and Rolimeter arthrometers. Panoramic AP standing radiographs of the lower limbs and lateral knee radiographs were also taken at the follow-up to evaluate limb length discrepancies (LLD) and axial malalignment. Normally distributed parameters were presented as mean ± standard deviation, while the non-normally distributed parameters were presented as median [25° percentile, 75° percentile].

RESULTS

Clinical scores showed significant (P < 0.01) improvement: Lysholm and KOOS scores improved from 40 [22; 65] and 59 [42, 73], respectively, to 100 [95; 100] and 99 [97;100] after surgery. Tegner score improved from 2 [2; 2] pre-operatively to 7 [3; 9] at follow-up (P < 0.01). At follow-up, IKDC score was A for 19 patients and one who scored B. All patients returned to sport activity and had good stability at follow-up: the KT1000 showed a median side-to-side difference of 0.0 mm [- 0.4; 1.0] for the standard force evaluation and 0.0 mm [- 1.0; 0.8] for manual-maximum test. The Rolimeter showed median side-to-site difference of 0.0 mm [- 1.0; 0.8]. Three minor leg length discrepancies and axial deviations were observed at the radiograph: one patient had 0.6 cm lengthening and 4° of varus, one had 1 cm lengthening, and one had 3° of varus (in comparison with the non-operated limb). No re-injury was observed.

CONCLUSION

This study demonstrates that the modified all-epiphyseal single-bundle "over-the-top" technique is a viable and safe option for ACL reconstruction in pediatric subjects. These results support once more that not only ACL reconstruction is a safe procedure in skeletally immature patients, but also it is highly recommended for those who want to pursue an active and sportive life.

LEVEL OF EVIDENCE

Case series, IV.

Anatomic Anterior Cruciate Ligament Reconstruction Using Hamstring Tendons Restores Quantitative Pivot Shift

Background:

It is still uncertain how surgical reconstruction of the anterior cruciate ligament (ACL) is able to restore rotatory laxity of the involved joint. The desired amount of restraint applied by the ACL graft, as compared with the healthy knee, has not been fully clarified.

Purpose:

To quantify the ability of single-bundle anatomic ACL reconstruction using hamstring tendons in reducing the pivot-shift phenomenon immediately after surgery under anesthesia.

Study Design:

Case series; Level of evidence, 4.

Methods:

An inertial sensor and image analysis were used at 4 international centers to measure tibial acceleration and lateral compartment translation of the knee, respectively. The standardized pivot-shift test was quantified in terms of the side-to-side difference in laxity both preoperatively and postoperatively with the patient under anesthesia. The reduction in both tibial acceleration and lateral compartment translation after surgery and the side-to-side difference were evaluated using the Wilcoxon signed-rank test. Alpha was set at P < .05.

Results:

A total of 107 patients were recruited for the study, and data were available for 89 patients. There was a statistically significant reduction in quantitative rotatory knee laxity between preoperatively (inertial sensor, 2.55 ± 4.00 m/s²; image analysis, 2.04 ± 2.02 mm) and postoperatively (inertial sensor, –0.54 ± 1.25 m/s²; image analysis, –0.10 ± 1.04 mm) between the involved and healthy joints, as measured by the 2 devices (P < .001 for both). Postoperatively, both devices detected a lower rotatory laxity value in the involved joint compared with the healthy joint (inertial sensor, 2.45 ± 0.89 vs 2.99 ± 1.10 m/s², respectively [P < .001]; image analysis, 0.99 ± 0.83 vs 1.09 ± 0.92 mm, respectively [P = .38]).

Conclusion:

The data from this study indicated a significant reduction in the pivot shift when compared side to side. Both the inertial sensor and image analysis used for the quantitative assessment of the pivot-shift test could successfully detect restoration of the pivot shift after anatomic single-bundle ACL reconstruction. Future research will examine how pivot-shift control is maintained over time and correlation of the pivot shift with return to full activity in patients with an ACL injury.

Association between incision technique for hamstring tendon harvest in anterior cruciate ligament reconstruction and the risk of injury to the infra-patellar branch of the saphenous nerve: a meta-analysis

PURPOSE

To determine how the incision technique for hamstring tendon (HT) harvest in anterior cruciate ligament (ACL) reconstruction affects the risk of injury to the IPBSN and clinical outcome.

METHODS

A systematic literature search of the MEDLINE/Pubmed, Cochrane Central Register of Controlled Trials (CENTRAL) and EBSCOhost electronic databases and clinicaltrials.gov for unpublished studies was performed to identify comparative studies investigating injury to the IPBSN after HT ACL reconstruction by comparing at least two different incision techniques. Data were extracted for the number of patients with evidence of any neurologic deficit corresponding to injury to the IPBSN, area of sensory deficit, the Lysholm score and patient satisfaction. The mean difference (MD) in study outcome between incision groups was assessed. The relative risk (RR) and the number needed to treat (NNT) were calculated. The Chi-square and Higgins' I² tests were applied to test heterogeneity. Data were pooled using a Mantel-Haenszel random-effects model if the statistical heterogeneity was > 50% and a fixed-effects model if the statistical heterogeneity was < 50%. The risk of bias was evaluated according to the Cochrane Database questionnaire and the quality of evidence was graded according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) guidelines.

RESULTS

A total of eight studies (three randomized controlled trials (RCTs) and five comparative studies) were included, of which six compared vertical and oblique incisions, one horizontal and vertical incisions, and one compared all three techniques. HT harvest was performed through a vertical incision in 329 patients, through an oblique incision in 195 patients and through a horizontal incision in 151 patients. Considering the meta-analysis of the RCTs, the performance of a vertical incision significantly increased the risk of causing IPBSN deficiency compared with both oblique and horizontal incision [RR 1.65 (CI 1.10-2.49, p = 0.02) and RR 2.45 (CI 1.73-3.47, p < 0.0001), respectively]. A significantly larger area of sensory deficit was found with vertical incisions compared with oblique ones, with an MD of 22.91 cm² (95% CI 7.73-38.08; p = 0.04). No significant differences were found between the incision techniques in relation to patient-reported outcomes. The same trend was obtained after the performing a meta-analysis of all eight included studies. The quality of evidence in this meta-analysis was determined as "low" to "moderate", mostly due to inadequate methods of randomization and high heterogeneity among the included studies.

CONCLUSION

The performance of a vertical incision to harvest HTs for ACL reconstruction significantly increased the risk of iatrogenic injury to the IPBSN compared with both oblique and horizontal incisions.

LEVEL OF EVIDENCE

Level I-III, meta-analysis of comparative studies.

Anatomical features of tibia and femur: Influence on laxity in the anterior cruciate ligament deficient knee

BACKGROUND

Until now, there has been a lack of in vivo analysis of the correlation between bony morphological features and laxity values after an anterior cruciate ligament (ACL) injury.

METHODS

Forty-two patients who underwent ACL-reconstruction were enrolled. Static laxity was evaluated as: antero-posterior displacement and internal-external rotation at 30° and 90° of flexion (AP30, AP90, IE30, IE90) and varus-valgus rotation at 0° and 30° of flexion (VV0, VV30). The pivot-shift (PS) test defined the dynamic laxity. Using magnetic resonance imaging, we evaluated the transepicondylar distance (TE), the width of the lateral and medial femoral condyles (LFCw and MFCw) and tibial plateau (LTPw and MTPw), the notch width index (NWI) and the ratio of width and height of the femoral notch (N-ratio), the ratio between the height and depth of the lateral and medial femoral condyle (LFC-ratio and MFC-ratio), the lateral and medial posterior tibial slopes (LTPs and MTPs) and the anterior subluxation of the lateral and medial tibial plateau with respect to the femoral condyle (LTPsublx and MTPsublx).

RESULTS

Concerning the AP30, LTPs (P=0.047) and MTPsublx (P=0.039) were shown to be independent predictors while for the AP90 only LTPs (P=0.049) was an independent predictor. The LTPs (P=0.039) was shown to be an independent predictor for IE90 laxity, while for the VV0 test it was identified as the LFCw (P=0.007).

CONCLUSIONS

A higher antero-posterior laxity at 30° and 90° of flexion was found in those with a lateral tibial slope <5.5°.

Over-the-top ACL Reconstruction Plus Extra-articular Lateral Tenodesis With Hamstring Tendon Grafts: Prospective Evaluation With 20-Year Minimum Follow-up

BACKGROUND

There are few published studies with very long-term follow-up of combined intra- and extra-articular anterior cruciate ligament (ACL) reconstruction.

PURPOSE

To analyze clinical and radiographic outcomes of over-the-top ACL reconstruction plus extra-articular lateral tenodesis with autologous hamstrings at minimum 20-year follow-up.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Of 60 originally eligible patients who underwent over-the-top ACL reconstruction with double-stranded hamstring tendon (leaving intact graft tibial insertions) and extra-articular lateral plasty (performed with the remnant part of tendons), 52 were prospectively evaluated at a minimum 20-year follow-up (mean follow-up, 24 years; 41 men, 11 women; mean age at time of surgery, 25.5 ± 7.6 years). Twenty-nine patients were available for prospective evaluations: clinical (Lysholm, Tegner, and objective International Knee Documentation Committee [IKDC]), instrumented (KT-2000), and radiographic (standard, long-standing, and Merchant views). Subjective KOOS (Knee injury and Osteoarthritis Outcome Score) and objective inertial sensor pivot-shift analysis (KiRA) were carried out at final follow-up. Twenty-three patients were investigated by phone interview for subjective Tegner score and documented complications, rerupture, or revision surgery.

RESULTS

At final follow-up, mean Lysholm score was 85.7 ± 14.6; median Tegner score, 4 (range, 3-5); sport activity resumption, 86.2%; and objective IKDC score, good or excellent in 86% of patients (31%, A; 55%, B). Only 3 of 26 patients (12%) had >5-mm manual maximum KT-2000 side-to-side difference. KiRA system documented positive pivot-shift (>0.9-m/s² tibial acceleration side-to-side difference) in these 3 of 26 patients (12%). Statistically significant changes were as follows: decrease in Tegner score from 7 (range, 6-8) at 5-year follow-up to 4 (range, 3-5) at 10 years ( P < .0001) and decrease in Lysholm score from 96.1 ± 7.3 at 10-year follow-up to 85.7 ± 14.6 at 20 years ( P = .0003). Radiographic evaluation demonstrated significant difference of medial joint space between injured and healthy knees in patients with concomitant medial meniscectomy (n = 8, 3.2 ± 0.6 vs 5.0 ± 1.8 mm, P = .0114). No significant differences were reported regarding lateral or patellofemoral joint space. One patient (2%) experienced rerupture, with 3 of 52 (5.8%) having a contralateral ACL injury (excluded from KT-2000 and radiographic evaluations). Overall, 4 of 29 clinical failures (objective IKDC, KT-2000) and 1 rerupture among 52 patients were registered at final follow-up.

CONCLUSION

Studied surgical technique demonstrated good results in laxity control at 20-year minimum follow-up. The lateral extra-articular plasty associated with ACL reconstruction did not generate lateral knee or patellofemoral osteoarthritis. The factor increasing osteoarthritis was meniscectomy.

Inertial sensors to quantify the pivot shift test in the treatment of anterior cruciate ligament injury

The main purpose of this article was to describe in detail, from the perspective of the clinical end user, a previously presented non-invasive methodology, applied in the treatment of anterior cruciate ligament injury, in which inertial sensors are used to quantify the pivot shift test. The outcomes obtained and relative considerations were compared with findings emerging from a review of the relevant updated literature.

The detailed description here provided covers the system, the parameters identified and the testing procedure; it also includes the technical specifications of the hardware, the features introduced in the updated version of the software and the application of the system in clinical practice.

The comparison of the technical considerations and clinical results with the updated literature confirmed the system’s optimal ergonomics, good reproducibility and clinical reliability.

The novel approach here analyzed has been shown to overcome the weaknesses of other available devices and systems. Therefore, since it can be considered a new paradigm in the quantification of pivot shift test, we can recommend its routine use in clinical practice.

Technical variables of ACL surgical reconstruction: effect on post-operative static laxity and clinical implication

PURPOSE

The hypothesis was that an alteration of different surgical variables of ACL reconstruction would produce significant changes in post-operative static laxity of knee joint.

METHODS

Joint laxity was acquired by a surgical navigation system for 17 patients just after graft fixation during single-bundle reconstruction with extra-articular lateral tenodesis. The analysed laxity parameters were: internal/external rotation at 30° (IE30) and 90° (IE90) of flexion, varus/valgus rotation at 0° (VV0) and 30° (VV30) of flexion and anterior/posterior displacement at 30° (AP30) and 90° (AP90) of flexion. As surgical variables, the angles between the tibial tunnel and the three planes were defined as well as the lengths of the tunnel and the relationship between native footprints and tunnels. The same analysis was performed for the femoral side. All surgical variables were combined in a multivariate analysis to assess for predictive factors between them and post-operative laxities values. To quantify the performance of each multivariate model, the correlation ratio (η ²) and the corresponding P value (*P < 0.050) have been evaluated.

RESULTS

Multivariate analysis underlined statistically significant models for the estimation of: AP30 (η ² = 0.987; P = 0.014), IE30 (η ² = 0.995; P = 0.005), IE90 (η ² = 0.568; P = 0.010), VV0 (η ² = 0.932; P = 0.003). The parameters that greatly affected the identified models were the orientation of the tibial tunnel with respect to the three anatomical planes. The estimation of AP30, IE30 and IE90 got lower value as the orientation of the tibial tunnel with respect to transverse plane decreases. Considering the orientation to sagittal ([Formula: see text]) and coronal ([Formula: see text]) plane, we found that their reduction provoked a decrease in the estimation of AP30, IE30 and IE90 (except [Formula: see text] that did not appear in the estimation of AP30). The estimation of VV0 got an increase of [Formula: see text], and [Formula: see text] which led to a laxity reduction.

CONCLUSION

The main finding of the present in vivo study was the possibility to determine significant effects on post-operative static laxity level of different surgical variables of ACL reconstruction. In particular, the present study defined the conditions that minimize the different aspects of post-operative laxity at time-zero after surgery.

Assessment of the pivot shift using inertial sensors

The pivot shift test is an important clinical tool used to assess the stability of the knee following an injury to the anterior cruciate ligament (ACL). Previous studies have shown that significant variability exists in the performance and interpretation of this manoeuvre. Accordingly, a variety of techniques aimed at standardizing and quantifying the pivot shift test have been developed. In recent years, inertial sensors have been used to measure the kinematics of the pivot shift. The goal of this study is to present a review of the literature and discuss the principles of inertial sensors and their use in quantifying the pivot shift test.

Is Sport Activity Possible After Arthroscopic Meniscal Allograft Transplantation? Midterm Results in Active Patients

BACKGROUND

Meniscal allograft transplantation (MAT) has produced good to excellent results in the general population; however, few investigations have examined MAT in athletes and sport-related outcomes.

PURPOSE

To report midterm clinical outcomes of MAT and the rate of return to sport in a physically active population.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

The study included all physically active patients who underwent arthroscopic MAT without bone plugs and had a minimum of 2 years of follow-up at a single institution. Clinical evaluation was performed with the Knee injury and Osteoarthritis Outcome Score (KOOS), the Tegner activity scale, and a 0- to 100-point subjective scale for knee function and satisfaction. Outcomes evaluated included ability to return to sport, time to return to sport, level of sport activity upon return compared with preinjury level, and level of decrease in sport participation or reasons for not returning to sport participation. Comparisons were made between patients who did or did not return to sport and between patients who returned to the same level or a decreased level. Regression analysis was performed to determine the variables affecting the outcomes.

RESULTS

Eighty-nine patients, whose mean ± SD age at surgery was 38.5 ± 11.2 years, were evaluated to a mean follow-up of 4.2 ± 1.9 years. Total KOOS improved from a mean ± SD of 39.5 ± 18.5 preoperatively to 84.7 ± 14.8 at the latest follow-up (P < .001). The Tegner score improved significantly from a median of 2 (interquartile range [IQR], 1-4) preoperatively to a median of 4 (IQR, 3-6) at the latest follow-up (P < .001), although it did not reach the preinjury level of 6 (IQR, 5-7) (P < .001). Older age at surgery was correlated with the worst clinical results. Sixty-six patients (74%) were able to return to sport after 8.6 ± 4.1 months. Forty-four (49%) returned to the same level as preinjury. Patients who did not return to sport activity and those who reduced their activity level at follow-up had inferior subjective outcomes compared with those who returned to sport and those who returned to their preinjury levels, respectively. Only 11 patients (12%) underwent a surgical procedure during the follow-up period.

CONCLUSION

Arthroscopic MAT without bone plugs improved knee function and reduced pain, allowing sport resumption in 74% of patients and return to the preinjury activity level in 49% of patients at midterm follow-up. Of all the demographic and surgical variables, only age at surgery seemed to affect outcomes.

Anterior cruciate ligament reconstruction with a novel porcine xenograft: the initial Italian experience

At the current state of the art in anterior cruciate ligament (ACL) reconstruction, multiple techniques have been presented but none has given clearly defined and improved results. One of the main issues concerns the choice of graft. The concept of using xenograft tissue, defined as a graft tissue from one species and destined for implantation in an unlike species, was introduced in order to try to overcome the mechanical and biological concerns associated with synthetic materials and the safety and quality concerns and availability problems of allograft tissue. Xenograft tissue carries the risk of producing an immunological reaction. In order to try to overcome or attenuate the immune response against porcine xenograft tissue, the Z-Process® (Aperion Biologics Inc, San Antonio, Texas, USA) has been developed and used to produce the Z-Lig® family of devices for ACL reconstruction procedures. Z-Lig® is a tendon graft with or without bone blocks, sourced from animal tissue in a manner consistent with what has normally been sourced from human tissue, and processed to overcome anti-Gal-mediated rejection and to attenuate other immunological recognition in humans. All this while ensuring sterility, viral inactivation and preservation of mechanical proprieties appropriate for an ACL reconstruction device. The Z-Lig® device has been tested in skeletally mature monkeys and given interesting and promising results from the preclinical performance and safety profile point of view. On this basis, it was possible to proceed with the first clinical trial involving humans, which gave similar encouraging results. The Z-Lig® device has also been implanted in Italy at the Rizzoli Orthopaedic Institute in Bologna, as a part of international multicenter prospective randomized blinded controlled study aimed at comparing xenograft with allograft tissue.

MRI evaluation of a collagen meniscus implant: a systematic review

PURPOSE

Good clinical results have been demonstrated in numerous clinical studies using the collagen meniscus implant (CMI); however, the MRI behaviour of the scaffold, evaluated with Genovese score, is limited to a few cases series. The purpose was to evaluate, using the Genovese score, the MRI behaviour of the CMI at different follow-up periods and investigate possible differences in the behaviour of lateral and medial CMI.

METHODS

A comprehensive search was performed on PubMed, Medline, CINAHL, Cochrane, Embase and Google Scholar databases using various combinations of the following keywords: "collagen meniscus implant" or "collagen meniscal implant". All the studies evaluating medial or lateral CMI using Genovese score for MRI were included in the systematic review.

RESULTS

Six studies have been included in the systematic review, with no RCT's. The pooled number of patients involved in CMI surgery was 194 (83 % medial and 17 % lateral), with a mean age at surgery of 37.7 years. Concomitant procedures raged from 11 to 52 %. CMI morphology was grade 1 in 0, 2.7, 5.9, 0, 16.7 %, respectively, at 6 months, 1, 2, 5, 10 years. It was grade 2 in 12.5, 60.9, 60.3, 74.4, 75 %, respectively, at 6 months, 1, 2, 5, 10 years and grade 3 in 87.5, 36.4, 33.8, 25.6, 8.3 % at the same time points. CMI signal intensity was grade 1 in 80, 18.2, 25, 11.1, 22.2 %, respectively, at 6 months, 1, 2, 5, 10 years. It was grade 2 in 20, 78.2, 54.7, 55.6, 66.7 %, respectively, at 6 months, 1, 2, 5, 10 years and grade 3 in 0, 3.6, 20.3, 33.3, 11.1 % at the same time points. Slight differences were found between medial and lateral CMI in size and signal intensity.

CONCLUSIONS

Higher rates of scaffolds with reduced size and with an MRI signal intensity more similar to normal meniscus were reported at longer follow-up compared with initial evaluations. Correlation between MRI findings and gross CMI appearance has not been reported.

LEVEL OF EVIDENCE

IV.

A novel germline mutation in the aryl hydrocarbon receptor-interacting protein (AIP) gene in an Italian family with gigantism

PURPOSE

Acromegaly usually occurs as a sporadic disease, but it may be a part of familial pituitary tumor syndromes in rare cases. Germline mutations in the aryl hydrocarbon receptor-interacting protein (AIP) gene have been associated with a predisposition to familial isolated pituitary adenoma. The aim of the present study was to evaluate the AIP gene in a patient with gigantism and in her relatives.

METHODS

Direct sequencing of AIP gene was performed in fourteen members of the family, spanning among three generations.

RESULTS

The index case was an 18-year-old woman with gigantism due to an invasive GH-secreting pituitary adenoma and a concomitant tall-cell variant of papillary thyroid carcinoma. A novel germline mutation in the AIP gene (c.685C>T, p.Q229X) was identified in the proband and in two members of her family, who did not present clinical features of acromegaly or other pituitary disorders. Eleven subjects had no mutation in the AIP gene. Two members of the family with clinical features of acromegaly refused either the genetic or the biochemical evaluation. The Q229X mutation was predicted to generate a truncated AIP protein, lacking the last two tetratricopeptide repeat domains and the final C-terminal α-7 helix.

CONCLUSIONS

We identified a new AIP germline mutation predicted to produce a truncated AIP protein, lacking its biological properties due to the disruption of the C-terminus binding sites for both the chaperones and the client proteins of AIP.

Combined ACL reconstruction and closing-wedge HTO for varus angulated ACL-deficient knees

PURPOSE

To report the medium-term clinical and radiographic outcomes of a group of patients who underwent anterior cruciate ligament (ACL) surgery combined with high tibial osteotomy (HTO) for varus-related early medial osteoarthritis (OA) and ACL deficiency knee.

METHODS

Thirty-two patients underwent single-bundle over-the-top ACL reconstruction or revision surgery and a concomitant closing-wedge lateral HTO. The mean age at surgery was 40.1 ± 8.1 years. Evaluation at a mean of 6.5 ± 2.7 years of follow-up consisted of subjective and objective IKDC, Tegner Activity Level, EQ-5D, VAS for pain and AP laxity assessment with KT-1000 arthrometer. Limb alignment and OA changes were evaluated on radiographs.

RESULTS

All scores significantly improved from pre-operative status to final follow-up. KT-1000 evaluation showed a mean side-to-side difference of 2.2 ± 1.0 mm. Two patients were considered as failures. The mean correction of the limb alignment was 5.6° ± 2.8°. Posterior tibial slope decreased at a mean of 1.2° ± 0.9°. At final follow-up, the mechanical axes crossed the medial-lateral length of tibial plateau at a mean of 56 ± 23 %, with only 1 patient (3 %) presenting severe varus alignment. OA progression was recorded only on the medial compartment (p = 0.0230), with severe medial OA in 22 % of the patients. No patients underwent osteotomy revision, ACL revision, UKA or TKA.

CONCLUSIONS

The described technique allowed patients with medial OA, varus alignment and chronic ACL deficiency to restore knee laxity, correct alignment and resume a recreational level of activity at 6.5 years of follow-up.

Ectopic expression of FSH receptor isoforms in neoplastic but not in endothelial cells from pancreatic neuroendocrine tumors

FSH receptor (FSHR) expression is restricted to gonads, where it drives FSH-dependent cell differentiation; in addition, FSHR plays an important role in the regulation of ovarian angiogenesis. Recently, FHSR expression has been shown in blood vessels of various tumors. However, pancreatic neuroendocrine tumors (p-NET), which have high-degree blood supply, were not included in that study. The aim of this study was to evaluate FSHR expression in p-NET. FSHR expression was evaluated in tumor samples from 30 patients with p-NET by immunohistochemistry and Western blot; fluorescence microscopy was used to localize FSHR in specific cells from tissue samples. von Willebrand factor (vWF) and chromograninA (chrA) was used as blood vessel and NET cells marker, respectively, to co-localize FSHR. FSHR expression was detected in all p-NET by immunohistochemistry. Western blot confirmed FSHR expression on p- NET although different FSHR isoforms, ranging from 240 kD to 55 kD were found in the samples studied. Surprisingly, FSHR co-localized with chrA but not with vWF, suggesting that neoplastic cells of neuroendocrine origin rather than blood vessels expressed FSHR. No relationship was found between degree of FSHR expression and histology of p-NET. FSHR may be aberrantly expressed in neoplastic cells from p-NET and not in tumor blood vessels; however, its biological significance as well as its clinical relevance remains to be elucidated.

The mechanisms of nadroparin-mediated inhibition of proliferation of two human lung cancer cell lines

OBJECTIVES

Clinical data suggest that heparin treatment improves survival of lung cancer patients, but the mechanisms involved are not fully understood. We investigated whether low molecular weight heparin nadroparin, directly affects lung cancer cell population growth in conventionally cultured cell lines.

MATERIALS AND METHODS

A549 and CALU1 cells' viability was assessed by MTT and trypan blue exclusion assays. Cell proliferation was assessed using 5-bromo-2-deoxyuridine incorporation. Apoptosis and cell-cycle distribution were analysed by flow cytometry; cyclin B1, Cdk1, p-Cdk1 Cdc25C, p-Cdc25C and p21 expressions were analysed by western blotting. mRNA levels were analysed by real time RT-PCR.

RESULTS

Nadroparin inhibited cell proliferation by 30% in both cell lines; it affected the cell cycle in A549, but not in CALU-1 cells, inducing arrest in the G(2) /M phase. Nadroparin in A549 culture inhibited cyclin B1, Cdk1, Cdc25C and p-Cdc25C, while levels of p-Cdk1 were elevated; p21 expression was not altered. Dalteparin caused a similar reduction in A549 cell population growth; however, it did not alter cyclin B1 expression as expected, based on previous reports. Fondaparinux caused minimal inhibition of A549 cell population growth and no effect on either cell cycle or cyclin B1 expression.

CONCLUSIONS

Nadroparin inhibited proliferation of A549 cells by inducing G(2) /M phase cell-cycle arrest that was dependent on the Cdc25C pathway, whereas CALU-1 cell proliferation was halted by as yet not elucidated modes.

[Implementing clinical pathways: some practical notes]

The traditional biomedical paradigm is no longer a guarantee of quality for health care, facing increasingly difficult challenges caused by chronic diseases and increasingly fragmented resources that current healthcare systems are dealing with. Health care organizations, considered to be the most complex enterprises of the modern era, must be able to focus on the flow of patients, integrating primary and secondary care through tools such as the Integrated Care Pathways (ICP). This brief discussion attempts to define the ICP its purposes, the elements that characterize it, its limitations and the mechanisms to push for a successful implementation. In order to highlight the elements and basic steps for the creation of an ICP, the authors have compared five different clinical pathways, whose implementation they have contributed to. The comparison was made using two grids: the first showing the essential elements for the definition of lCP and the second one with features that can facilitate their effectiveness. The conclusions of the work show what, pursuing the construction of a pathway, we must never forget: to analyze the gap between the clinical-care activities performed and the theoretical framework provided by the evidence; to see the barriers to change that may impede the implementation; to involve all actors in the system, with particular attention to patients and their associations, and finally to provide a plan for information and education, addressed to health professionals and patients as well.

Effect of rosiglitazone on serum IGF-I concentrations in uncontrolled acromegalic patients under conventional medical therapy: results from a pilot phase 2 study

OBJECTIVE

Current therapies for acromegaly are unsatisfactory for some patients. High-dose thiazolidinediones have been reported to reduce serum GH levels in animal models of acromegaly. The objective of the study was to evaluate the effect of increasing doses of rosiglitazone on serum GH and IGF-I concentrations in acromegalic patients.

DESIGN

Phase 2 clinical trial.

PATIENTS AND METHODS

Five consecutive patients with active and uncontrolled acromegaly under conventional medical therapies were treated with increasing doses of rosiglitazone [4 mg/day every month, starting from 8 up to 20 mg/day] added to previous medical therapies for acromegaly.

RESULTS

Mean serum IGF-I concentrations decreased from 547 ± 91 to 265 ± 126 μg/l (p<0,001) during rosiglitazone treatment: 4 patients had normal serum IGF-I concentrations, and a patient had lowered serum IGF-I values, although still abnormal, at the end of the study. On the contrary, serum GH concentrations did not significantly changed during rosiglitazone therapy as well as other pituitary hormones. No relevant side effects of rosiglitazone were observed during the study period. Quantitative real time PCR and Western blotting showed that rosiglitazone lowered GH-dependent hepatic generation of IGF-I in HepG2 cell line.

CONCLUSIONS

Rosiglitazone reduces serum IGF-I concentrations in patients with uncontrolled acromegaly under conventional medical therapies, likely acting on the GH-dependent hepatic synthesis of IGF-I. Large studies are necessary to confirm the role of rosiglitazone as an adjunctive therapy for uncontrolled acromegalic patients under conventional medical therapies.

Somatostatin analogues do not affect calcium metabolism in patients with acromegaly and primary hyperparathyroidism [corrected] due to MEN 1-like syndrome

Patients with clinical features of MEN 1 without mutations in the menin gene fulfill the criteria of MEN1-like syndrome. Primary hyperparathyroidism (PHP) is the most frequent clinical finding in both syndromes and is usually treated by surgery. However, PHP has been reported to respond to somatostatin analogues (SSA) in MEN 1 patients. 7 patients with PHP in the context of MEN 1-like syndrome (and absence of mutations in the menin gene) were enrolled in the study and treated with SSA for 6 months for the non-PHP disease before parathyroidectomy. Serum ionized calcium, phosphorus, and PTH concentrations, and 24-h urinary calcium and phosphorus excretion were measured before and after SSA therapy. Mean serum ionized calcium, phosphorus, and PTH concentrations did not significantly change after a 6-month course with SSA. SSA scintigraphy did not reveal uptake in the neck region corresponding to the parathyroid adenoma identified at surgery and confirmed at histology. However, immunohistochemistry revealed SS-type 2A receptor in parathyroid tissue samples of 6 out of 7 patients. SSA therapy does not affect calcium-phosphorus metabolism in patients with MEN 1-like syndrome, suggesting that the drug has no role in controlling PHP in these subset of patients.

Effects of cyclotronic ion resonance on human metabolic processes: a clinical trial and one case report

We studied the effects of ion cyclotron resonance (Seqex) magnetic therapy on the blood of thirty two healthy volunteers. They received 15 treatments each 27 minutes in length, distributed over 5 weeks. The concentrations of two blood components, malondialdehyde (MDA) and cholesterol were measured in each subject, immediately before and immediately after the 15 treatments as well as one month after the final treatment. Highly significant reductions in MDA concentrations, averaging 53.8% were noted just after the 15 treatments, tending to return to the original concentrations one month later. The effect on HDL and LDL cholesterol levels were not significant. The implication of this work is that this type of therapy may be useful in dealing with oxidative stress.

Uptake of amiodarone by thyroidal and non-thyroidal cell lines

Amiodarone perturbs thyroid function, causing overt hypothyroidism or hyperthyroidism in 15% of patients. Changes in thyroid function are likely due, at least in part, to amiodarone and/or desethylamiodarone (DEA) concentration into the thyroid gland, but mechanisms whereby the drug uptake occurred are not known. Thyroidal (FRTL-5) or non-thyroidal [Chinese hamster ovary wild-type (CHOwt) or CHO stably transfected with NIS (CHO-NIS)] cells were exposed to 10 microM amiodarone or DEA. Cellular content of both drugs was measured by HPLC and normalized by protein concentration. Cellular concentration of the two drugs was higher in FRTL-5 (mean +/- SD 17.2 +/- 1.2 microg/mg protein of amiodarone and 18.9 +/- 0.7 microg/mg protein of DEA) than in CHO-NIS and CHOwt cells (10.8 +/- 0.8 microg/mg protein and 12.8 +/- 0.2 microg/mg protein, respectively, of amiodarone (p < 0.004); 11.9 +/- 0.1 microg/mg protein and 11 +/- 0.2 microg/mg protein, respectively, of DEA (p < 0.0002). DEA concentration was higher than that of amiodarone in all cell lines (p < 0.002). Differences between FRTL-5 and CHO cell lines were not dependent on TSH: in fact, cellular content of either drug did not change in the presence or absence of TSH in the culture medium. NIS did not intervene in amiodarone or DEA entry into thyroid cells, since amiodarone and DEA content was the same in CHOwt and CHO-NIS cells; in addition, KClO4 inhibited NIS function, but had no effect on drug uptake by the cells. At variance, 80 microM DEA reduced 125I uptake by CHO-NIS cells by 40% at 30 min without affecting cell viability. In conclusion, mechanisms whereby amiodarone is taken up by thyroid cells remain largely unknown, but the two main factors involved in thyroid-specific cellular transport, ie, NIS and TSH, seem to be excluded.

Peroxisome proliferator-activated receptor (PPAR)gamma is highly expressed in normal human pituitary gland

OBJECTIVE

Expression of peroxisome proliferator-activated receptor (PPAR)gamma in normal pituitary seems to be restricted to ACTH-secreting cells. The aim of the study was to evaluate the expression of PPARgamma in normal human pituitary tissue and to study its localization in the pituitary secreting cells.

MATERIALS AND METHODS

Normal pituitary tissue samples were obtained form 11 patients with non-secreting adenoma who underwent surgical excision of the tumor. Expression of PPARgamma was evaluated by immunostaining and western blotting; localization of PPARgamma in each pituitary secreting cell lineage was evaluated by double immunofluorescence using confocal microscopy. Pituitary non-functioning adenomas served as Controls.

RESULTS

PPARgamma was highly expressed in all pituitary samples with a (mean +/- SD) 81 +/- 6.5% of stained cells; expression of PPARgamma was confirmed by western blotting. Non-functioning pituitary adenomas had 74 +/- 11% PPARgamma positive cells. Expression of PPARy was either in cytoplasm or nuclei. In addition, treatment of GH3 cells, with a PPARgamma ligand was associated with traslocation of the receptor from cytoplasm into the nucleus. Double immunostaining revealed that every pituitary secreting cell (GH, TSH, LH, FSH, PRL and ACTH) had PPARgamma expressed.

DISCUSSION

The present study demonstrated that PPARgamma is highly expressed in every normal pituitary secreting cell lineage. It can translocate into the nucleus by ligand binding; however, its role in pituitary hormone regulation remains to be elucidated.

Mutations in the SLC26A4 (pendrin) gene in patients with sensorineural deafness and enlarged vestibular aqueduct

Pendred syndrome and the enlarged vestibular aqueduct (EVA) are considered phenotypic variations of the same entity due to mutations in the SLC26A4 (pendrin) gene. Pendred syndrome consists in sensorineural deafness, goiter and impaired thyroid hormone synthesis while in EVA thyroid function seems to be preserved. The aim of this study was to evaluate thyroid function and morphology and to look for mutations in the SLC26A4 gene in patients presented with EVA. Among 57 consecutive patients with sensorineural deafness 15 with EVA, as assessed by magnetic resonance imaging (MRI), were identified and studied. A complete evaluation of thyroid function including thyroid echography and perchlorate discharge test was carried out in all patients with EVA; all exons of the SLC26A4 gene were amplified from peripheral leukocytes and directly sequenced, using specific intronic primers. Out of 15 patients with EVA, goiter was present in 8 (53%), hypothyroidism in 7 (47%), increased serum thyroglobulin levels in 8 (53%) and a positive perchlorate discharge test in 10 (67%). Nine alleles of the SLC26A4 gene were mutated: 2 novel mutations (L465W and G497R) and 4 already known mutations (T410M, R409H, T505N and IVS1001+1G>A) were found. Four subjects were compound heterozygous and 1 heterozygous (G497R/wt). All patients harbouring mutations in the SLC26A4 gene had goiter and a positive perchlorate discharge test: 3 were slightly hypothyroid and 2 euthyroid. The remaining 10 patients had no mutations in the SLC26A4 gene: 4 of them were hypothyroid, 2 with goiter and positive perchlorate discharge test, 2 without goiter and with negative perchlorate discharge test. Two patients without mutations were euthyroid with positive perchlorate discharge test. Patients with mutations in the SLC26A4 gene had larger thyroid volume (p<0.002), higher serum thyroglobulin (Tg) levels (p<0.002) and greater radioiodine discharge after perchlorate (p=0.09) than patients without mutations. The results of the present study lend support to the concept that all patients with mutated SLC26A4 gene have abnormalities of thyroid function tests.

Colonic polyps of acromegalic patients are not associated with mutations of the peroxisome proliferator activated receptor gamma gene

Peroxisome proliferator activated receptor (PPAR)gamma plays a pivotal role in regulating adipocyte differentiation and metabolism, but also has an antiproliferative effect in several tissues, including colonic mucosa, where it is highly expressed. Loss-of-function mutations have been reported in about 10% of sporadic primary colon cancer. Acromegalic patients have an increased prevalence of colonic neoplasms and lower PPARgamma levels in the colonic mucosa. Thus, PPARgamma may act as a tumor suppressor gene, and its reduced expression or loss-of-function mutations may contribute to tumorigenesis. In this study the expression and mutations of the PPARgamma gene in the colonic polyps and mucosa outside polyps were investigated in 10 acromegalic and 17 non-acromegalic patients. PPARgamma expression was evaluated by RT-PCR. PPARgamma was expressed in each sample, but expression appeared to be lower in polyps than in mucosa outside polyps from either acromegalic or non-acromegalic patients. All exons of the PPARgamma gene were directly sequenced after PCR amplification: no mutations were found either in acromegalic or in non-acromegalic patients. In conclusion, the results of this preliminary study suggest that the lower expression of PPARgamma rather than somatic mutations of this gene is involved in colonic tumorigenesis.

Effects of a mixture of polychlorinated biphenyls (Aroclor 1254) on the transcriptional activity of thyroid hormone receptor

Polychlorinated biphenyls (PCBs) are environmental contaminants which may affect thyroid function. PCBs may reduce serum thyroid hormone (TH) concentrations by either displacing T4 from TH transport proteins or increasing its hepatic metabolism. The reduced serum T4 causes neurological and growth defects in animals exposed to PCBs during the perinatal period, which can partially be reverted by T4 administration. In addition to a hypothyroid-like syndrome, a direct action of PCBs on TH-sensitive genes has been postulated. In the present study the effects of Aroclor 1254 (ARO), a mixture of PCBs, on transcription of TH-dependent genes were investigated. A reporter plasmid containing the TH-responsive element (TRE) of malic enzyme (ME) gene was used in transient transfections to assess the responsiveness to ARO. ARO (10 microM) reduced the CAT activity by about 50% and competed with T3 to reduce the induction of transcription. Cotransfection of TH receptor (TR) and a wild type TRE was required to reveal ARO inhibitiry effect, which was abolished by a mock reaction not containing TR or by a mutated TRE. ARO reduced the 125I-T3 binding to TR by 30%, but did not affect the interaction of TR with a 32P-labeled TRE in gel shift assay. ARO is likely to produce a conformational change in in vitro translated TR, leading to its increased proteolysis by trypsin. These results demonstrate that ARO interacts with TR, thereby affecting the transcription of TH-sensitive genes, and provide a molecular basis to further explain the complex effects of PCBs on TH disruption.

Desethylamiodarone antagonizes the effect of thyroid hormone at the molecular level

OBJECTIVE

To evaluate the molecular mechanisms of the inhibitory effects of amiodarone and its active metabolite, desethylamiodarone (DEA) on thyroid hormone action.

MATERIALS AND METHODS

The reporter construct ME-TRE-TK-CAT or TSHbeta-TRE-TK-CAT, containing the nucleotide sequence of the thyroid hormone response element (TRE) of either malic enzyme (ME) or TSHbeta genes, thymidine kinase (TK) and chloramphenicol acetyltransferase (CAT) was transiently transfected with RSV-TRbeta into NIH3T3 cells. Gel mobility shift assay (EMSA) was performed using labelled synthetic oligonucleotides containing the ME-TRE and in vitro translated thyroid hormone receptor (TR)beta.

RESULTS

Addition of 1 micromol/l T4 or T3 to the culture medium increased the basal level of ME-TRE-TK-CAT by 4.5- and 12.5-fold respectively. Amiodarone or DEA (1 micromol/l) increased CAT activity by 1.4- and 3.4-fold respectively. Combination of DEA with T4 or T3 increased CAT activity by 9.4- and 18.9-fold respectively. These data suggested that DEA, but not amiodarone, had a synergistic effect with thyroid hormone on ME-TRE, rather than the postulated inhibitory action; we supposed that this was due to overexpression of the transfected TR into the cells. When the amount of RSV-TRbeta was reduced until it was present in a limited amount, allowing competition between thyroid hormone and the drug, addition of 1 micromol/l DEA decreased the T3-dependent expression of the reporter gene by 50%. The inhibitory effect of DEA was partially due to a reduced binding of TR to ME-TRE, as assessed by EMSA. DEA activated the TR-dependent down-regulation by the negative TSH-TRE, although at low level (35% of the down-regulation produced by T3), whereas amiodarone was ineffective. Addition of 1 micromol/l DEA to T3-containing medium reduced the T3-TR-mediated down-regulation of TSH-TRE to 55%.

CONCLUSIONS

Our results demonstrate that DEA, but not amiodarone, exerts a direct, although weak, effect on genes that are regulated by thyroid hormone. High concentrations of DEA antagonize the action of T3 at the molecular level, interacting with TR and reducing its binding to TREs. This effect may contribute to the hypothyroid-like effect observed in peripheral tissues of patients receiving amiodarone treatment.

A novel mutation in the pendrin gene associated with Pendred's syndrome

OBJECTIVE

Pendred's syndrome is an autosomal recessive disorder characterized by goitre, sensorineural deafness and iodide organification defect. It is one of the most frequent causes of congenital deafness, accounting for about 10% of hereditary hearing loss. It is caused by mutations in the pendrin (PDS) gene, a 21 exon gene located on chromosome 7. The aim of this study was to examine an Italian family affected with Pendred's syndrome at the molecular level.

PATIENTS

Thirteen subjects belonging to a family from Southern Italy were evaluated for the clinical and genetic features of Pendred's syndrome.

MEASUREMENTS

Exons 2-21 of the PDS gene were amplified from peripheral leucocytes by the polymerase chain reaction; mutation analysis was performed by single strand conformation polymorphism, direct sequencing and restriction analysis.

RESULTS

The index patient had the classical triad of the syndrome and harboured two mutations in the PDS gene in the form of compound heterozygosity. He was found to be heterozygous for a cytosine to adenosine mutation at nucleotide 1523 in exon 13 and for a IVS 1001 + 1G --> A mutation. The former is a novel mutation which results in a change of 508 threonine to asparagine in the putative eleventh transmembrane domain. The latter mutation in the donor splice site has already been described in other patients and is thought to lead to aberrant splicing and premature protein truncation. Three subjects who were heterozygous for one mutation had normal phenotypes. Two subjects had sensorineural deafness and were heterozygous for a single mutation. Goitre was found only in patients with Pendred's syndrome and was absent in all other individuals, albeit residing in an iodine-deficient area.

CONCLUSIONS

We have identified a novel mutation in the pendrin gene causing Pendred's syndrome, and confirm that molecular analysis is a useful tool for a definitive diagnosis. This is particularly relevant in cases such as in the subjects of our family in which the clinical features might be misleading and other genetics factors might be responsible for deafness.

Pendrin does not increase sulfate uptake in mammalian COS-7 cells

Pendred's syndrome is characterized by goiter, sensorineural deafness and impaired iodide organification. It is one of the most frequent causes of congenital deafness accounting for about 10% of hereditary hearing loss. It is caused by mutations in the pendrin (PDS) gene, which was postulated to be a sulfate transporter, because of its homology with other genes. We tested sulfate transport in mammalian COS-7 cells that were transiently transfected with PDS cDNA. 35SO4 uptake increased in a time-dependent manner, but this phenomenon was similar in cells transfected with PDS and in mock-transfected cells (450 and 360 cpm/beta-gal units at 10 min, respectively; 38,250 and 31,000 cpm/beta-gal units, at 12 h, respectively). There was no significant increase in 35SO4 uptake using increasing amounts of PDS-containing plasmid (up to 12 microg per dish). These data indicate that pendrin is not a sulfate transporter. Additional functional studies on this protein are warranted to clarify its role in thyroid pathophysiology and inner ear development.

Left origin of the atrial esophageal signal as recorded in the pacing site

Clear atrial depolarizations from inside the esophagus have always been recorded in electrocardiology, but their precise origin is still under discussion. Though atrial signals are recorded along most of the esophagus, pacing of the atria is possible only in a short tract, probably where the esophagus is in contact with the posterior left atrium wall. In order to ascertain which portion of atria gives rise to the esophageal atrial signal recorded in the atrial pacing segment, we examined 37 patients with normal P waves on the standard ECG by inserting esophageal and endocavitary catheters. The interval between the earliest start of the P wave and the bipolar atrial deflection, was measured both through the esophagus (PA-Eso) and the Hisian region (PA-His) (the latest depolarization of interatrial septum). The former was longer than the latter (P < 0.001) in 36 of 37 patients, showing that the esophagus recorded atrial signal, at the site of effective pacing, originates outside the interatrial septum. As the atrial depolarization recorded through the esophagus is significantly delayed compared with the Hisian region recording, a pure left origin of the esophageal signal can be hypothesized. This is supported by the well-known delayed depolarization, during sinus rhythm, of the left atrium posterior wall compared with the right atrium and interatrial septum. Measuring the interval between the standard ECG P wave and atrial depolarization recorded through esophagus in the site of effective pacing, provides a reliable noninvasive estimate of interatrial time conduction.