Almost 79% survival rate at 10-year follow-up for the patellofemoral joint arthroplasty: An Italian prosthetic registry study.

PURPOSE: The aims of the present study were (1) to evaluate the survival of patellofemoral joint (PFJ) arthroplasty in a large cohort of patients using data obtained from an Italian regional arthroplasty registry and (2) to collect clinical outcomes of a subgroup of patients, with a minimum follow-up of 4 years. The hypotheses were that PFJ arthroplasty is a procedure that had good survival and clinical outcomes, not inferior to those reported in the literature for primary total knee arthroplasty (TKA). METHODS: The Register of Orthopaedic Prosthetic Implants (RIPO) of Emilia-Romagna (ER) (Italy) database was searched for the inclusion of all PFJ arthroplasties implanted between 2003 and 2019. PFJ arthroplasties were excluded if they were implanted in patients who lived outside of the ER. The survival information was extrapolated from the RIPO considering the partial or total revision of the implant as failure; moreover, a subgroup of patients was contacted and interviewed by telephone to collect clinical outcomes. Descriptive statistics were used to summarise the data. The survival curve was calculated and plotted using the Kaplan-Meier method. RESULTS: A total of 126 arthroplasties in 114 patients were included in the final analysis (mean age at surgery 60.1 ± 11.5 years old). The main causes of patellofemoral arthroplasty were primary osteoarthritis (88%) and posttraumatic arthritis (7%). The survival was 90.4 ± 30.6 and 78.8 ± 51.5 at 5 and 10 years of follow-up, respectively. At the latest follow-up, 23 implants failed (18.3%). The main cause of revision was osteoarthrosis progression (34.8%). A total of 44 patients were contacted by telephone to collect clinical outcomes: Western Ontario and McMaster Universities Osteoarthritis Index, functional Knee Society Score, Forgotten Joint Score and Oxford Knee Score. These patients reported good to excellent scores at a medium follow-up of 10.3 ± 4.7 years. CONCLUSIONS: The PFJ showed good survival and clinical outcomes and could be considered a valuable option for patients affected by isolated patellofemoral osteoarthritis. LEVEL OF EVIDENCE: Level IV.

Satisfactory long-term outcomes for combined anterior cruciate ligament reconstruction and lateral closing wedge high tibial osteotomy.

PURPOSE: A combined anterior cruciate ligament (ACL) reconstruction and high tibial osteotomy (HTO) is considered a valuable treatment in young patients affected by symptomatic medial osteoarthritis and ACL deficiency. However, only a few studies have investigated the outcomes of this procedure, especially in the long term. Therefore, the aim of this study is to report clinical and radiographic outcomes of ACL reconstruction and lateral closing wedge HTO at a mean of 14 years of follow-up. METHODS: Patients were prospectively evaluated pre-operatively, after 6.5 ± 2.7 years and 14.3 ± 2.2 years. Patient-reported outcome measures (PROMs) were collected, knee laxity was assessed through KT-1000 arthrometer, and limb alignment and knee osteoarthritis were evaluated on long-cassette radiographs. Survivorship of the surgical procedure was calculated through the Kaplan-Meier method. RESULTS: 32 patients were initially enrolled and completed the mid-term evaluation (6.5 ± 2.7 years), and 23 patients (72%) were available for the final evaluation at 14.3 ± 2.2 years after surgery. Statistically significant improvement was found for all the clinical scores (VAS, WOMAC, Tegner, subjective IKDC, objective IKDC) between the pre-operative status and the mid-term follow-up (p < .001). VAS, subjective IKDC and objective IKDC showed no statistically significant differences (p > .05) between the mid-term and the final follow-up; a significant decrease of WOMAC (p < .05) and Tegner (p < .001) was found from mid-term to final follow-up. Significant progression of osteoarthritis was found for all the knee compartments. The survivorship was 95.7% at 5 years, 82.6% at 10 years, and 72.8% at 15 years. CONCLUSIONS: Combined ACL reconstruction and lateral closing wedge HTO showed satisfactory clinical outcomes and survivorship at a mean of 14 years follow-up. LEVEL OF EVIDENCE: IV.

The sagittal geometry of the trochlear groove could be described as a circle: an intraoperative assessment with navigation.

PURPOSE: The aim of this study was to describe the sagittal geometry of the trochlear groove in patients who underwent primary TKA, based on intraoperative data acquired with a navigation system. METHODS: Intraoperative navigation data were collected from 110 patients. All operations were guided by a non-image-based navigation system (BLU-IGS, Orthokey Italia Srl). The trochlear groove has been described on the three anatomical planes; in particular, on the sagittal plane the hypothesis has been verified that the acquired points are referable to a circle. Using the data collected during intraoperative navigation, possible correlation between the radius of the trochlear groove and other femur dimension (length, AP dimension) was analyzed; the orientation of the trochlear sulcus with respect to the mechanical axis and the posterior condyle axis was analyzed too, searching for possible correlation between groove alignment (frontal and axial) or groove radius and the hip-knee-ankle (HKA). RESULTS: The average radius of curvature of the femoral trochlea was 25.5 ± 5.6 mm; the difference was not statistically significant between the men and women (n.s. p value). No correlation was found between the trochlear groove radius and the femur length (r = - 0.02) or the HKA-phenotypes (r = 0.03) and between the groove alignment and HKA-phenotypes. On axial plane, the trochlear groove was 3.2° ± 4.3° externally rotated, with respect to the posterior condylar axis; on frontal plane, the trochlear groove was 3.9° ± 5.3° externally rotated, with respect to the mechanical axis. In both cases, no statistically significant differences were found between male and female and between left and right limb (p > 0.05). CONCLUSION: The present study shows that the sagittal plane geometry of the femoral trochlea in patients affected by osteoarthritis could be described accurately as a circle. The acquisition of the trochlear morphology intraoperatively can lead to more anatomically shape definition, to investigate deeper its radius of curvature and geometry. Trochlear shape could be used as landmarks for femoral component positioning, thus customizing the implant design, optimize the outcomes and improving anterior knee pain after TKA. LEVEL OF EVIDENCE: IV.

Difficult primary total knee arthroplasty requiring a varus-valgus constrained implant is at higher risk of periprosthetic infection.

PURPOSE: The goal of this study was to compare the risk of periprosthetic infection of a consecutive cohort of primary varus-valgus constrained (VVC) total knee arthroplasties (TKAs), with a matched 1:1 cohort of primary posterior-stabilized (PS) TKAs. METHODS: 74 primary VVC TKAs performed in 66 patients were identified and matched 1:1 with a cohort of 74 primary PS TKAs performed in 73 patients. At last follow up, patients were clinically evaluated using the Knee Society Score (KSS). Kaplan-Meier survival curves were generated to analyze survivorship using as endpoints revision for any reason, revision for periprosthetic infection and revision for mechanical failure after excluding periprosthetic infection. A multivariate logistic regression analysis was constructed to determine whether revision surgery for periprosthetic infection was influenced by patients' gender, age, surgical time and reasons for TKA (primary vs secondary osteoarthritis). RESULTS: Demographic data were not significantly different between the two groups as regard patients' age, gender, body mass index, Charlson Comorbidity Index, reasons for replacement, and length of follow-up. Surgical time was greater in the VVC group (95.7 ± 22.5 min vs 88.6 ± 17.1 min, respectively, p = 0.032). Postoperative KSS, range of motion and radiographic data did not differ significantly between the two groups. Overall revision rate and revision rate for mechanical failure after 5 years of follow-up was not statistically different between the two groups. Considering only the revision rate due to periprosthetic infection, the risk was higher in patients with primary VVC implants (p = 0.013). The surgical time was the only factor that significantly affected the risk of revision for periprosthetic infection (OR 1.0636, CI 95% 1.0209-1.1081, p = 0.0032), whereas patients' gender, age and reason for TKA had no influence. CONCLUSIONS: Patients and surgeons should be aware of the higher risk of periprosthetic knee infection using a VVC prosthesis. However, the present study supports the use of VVC implants in cases of difficult knee replacements, since comparable clinical outcomes and overall revision rate was found after at least 5 years of follow up. LEVEL OF EVIDENCE: Retrospective cohort study, Level III.

New design total knee arthroplasty shows medial pivoting movement under weight-bearing conditions.

PURPOSE: To assess, using model-based dynamic radiostereometric analysis (RSA), the biomechanical behaviour of a new design posterior-stabilized (PS) fixed-bearing (FB) total knee arthroplasty (TKA) in vivo while patients performing two common motor tasks. The hypothesis was that model-based dynamic RSA is able to detect different behaviour of the implant under weight-bearing and non-weight-bearing conditions. METHODS: A cohort of 15 non-consecutive patients was evaluated by dynamic RSA 9 months after TKA implantation. The mean age of patients was 73.4 (65-72) years. The kinematic evaluations were performed using an RSA device (BI-STAND DRX 2) developed in our Institute. The patients were asked to perform two active motor tasks: sit-to-stand in weight-bearing condition; range of motion (ROM) while sitting on the chair. The motion parameters were evaluated using the Grood and Suntay decomposition and the low-point kinematics methods. RESULTS: The dynamic RSA evaluation showed a significant difference (p < 0.05) between the biomechanical behaviour of the prosthesis during the two motor tasks. When subjected to the patient weight (in the sit-to-stand) the low point of the medial compartment had a shorter motion (5.7 ± 0.2 mm) than the lateral (11.0 ± 0.2 mm). This realizes a medial pivot motion as in the normal knee. In the ROM task, where the patient had no weight on the prosthesis, this difference was not present: the medial compartment had a displacement of 12.7 ± 0.2 mm, while the lateral had 17.3 ± 0.2 mm. CONCLUSIONS: Model-based RSA proved to be an effective tool for the evaluation of TKA biomechanics. In particular, it was able to determine that the fixed-bearing posterior-stabilized TKA design evaluated in this study showed a medial pivoting movement under weight-bearing conditions that was not present when load was not applied. Under loading conditions what drives the pattern of movement is the prosthetic design itself. By the systematic use of this study protocol future comparisons among different implants could be performed, thus contributing significantly to the improvement of TKA design. LEVEL OF EVIDENCE: IV.

Is Treatment With Dithiothreitol More Effective Than Sonication for the Diagnosis of Prosthetic Joint Infection?

BACKGROUND: Prosthetic joint infection (PJI) is among the most-severe complications of a total joint arthroplasty. Identification of the causal organism is of paramount importance for successful treatment, and sonication of implants may aid in this identification. Dithiothreitol (DTT) treatment has been proposed as an alternative to sonication to improve diagnosis, reduce costs, and improve reliability of the procedure, but its efficacy remains poorly characterized. QUESTIONS/PURPOSES: (1) Are DTT and sonication more sensitive and/or more specific than standard cultures of tissue samples for the diagnosis of PJI? (2) Which test (DTT or sonication) is more sensitive when the clinician does not suspect infection before surgery? (3) Which test (DTT or sonication) is more sensitive when the clinician suspects infection before surgery? METHODS: Two hundred thirty-two patients undergoing revision of a knee or hip arthroplasty were prospectively evaluated in this randomized study. Cultures were performed on five tissue samples from each patient and on fluid obtained by prosthesis treatment in patients randomly assigned to sonication (117 patients) or DTT (115 patients). The reference standard against which cultures (on tissue samples and on fluids from sonication or DTT) were compared was the Musculoskeletal Infection Society definition of PJI. RESULTS: Cultures on sonication and DTT fluids provided higher sensitivity (89% and 91%, respectively) than those on standard cultures of tissue samples (79%; p < 0.001). Among patients in whom infection was not suspected before surgery, the sensitivity of DTT was greater than that for sonication and cultures on tissue samples (100% versus 70% and 50%; p < 0.001). Among patients in whom infection was suspected before surgery, the sensitivity of DTT and sonication were not greater than that for standard cultures (89% and 94% versus 86%). CONCLUSIONS: In this randomized study, we found no difference in sensitivity between DTT and sonication for the detection of PJI, and both of those tests were more sensitive than standard tissue cultures. Thus, cultures of sonication or DTT fluid should be considered important additional tools to standard cultures for definition of PJI and should be considered together with other criteria, especially in settings where infection is not suspected before revision surgery.Level of Evidence Level I, diagnostic study.

Constipation in older people: A consensus statement.

BACKGROUND AND AIMS: Chronic constipation is a serious medical condition that affects 30%-40% of people over 60 years old. Although not normally life threatening, constipation reduces quality of life by the same extent as diabetes and osteoarthritis. There are currently no Europe-wide guidelines for treating constipation in older people, although there is some country-level guidance for the general population. We have evaluated the existing guidance and best clinical practice to improve the care of older people with constipation. METHOD: European healthcare professionals working in gastroenterology, geriatrics, nursing and pharmacology discussed the treatment of constipation in older people and reviewed existing guidance on the treatment of constipation in the general population. This manuscript represents the consensus of all authors. DISCUSSION: Most general guidance for constipation treatment recommends increased dietary fibre, fluid intake and exercise; however, this is not always possible in older patients. Although a common first-line treatment, bulk-forming laxatives are unsuitable for older people because of an associated need to increase fluid intake, osmotic laxatives are likely to be the most suitable laxative type for older patients. Treatment is often hampered by reluctance to talk about bowel problems so healthcare providers should proactively identify older constipated patients who are self-medicating or not receiving treatment. CONCLUSIONS: With certain modifications, general treatment guidelines can be applied to older people with constipation, although specific guidelines are still required for this age group. Awareness of constipation, its complications and treatment options need to be increased among healthcare providers, patients and carers.

Does revision ACL reconstruction measure up to primary surgery? A meta-analysis comparing patient-reported and clinician-reported outcomes, and radiographic results.

PURPOSE: To compare patient-reported and clinician-reported outcomes, and radiographic results between patients who had had revision ACL reconstruction and those who had had primary ACL reconstruction. DESIGN: Systematic review and meta-analysis DATA SOURCES: The MEDLINE, CINAHL, EMBASE and SPORTDiscus electronic databases were searched on 6 August 2015, using 3 main concepts: (1) revision ACL reconstruction, (2) primary ACL reconstruction and (3) treatment outcomes. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Articles that compared patient-reported or clinician-reported outcomes or radiographic results between patients who had had revision ACL reconstruction and those who had had primary surgery with a minimum of 2 years follow-up were included. The outcomes evaluated were the Lysholm Knee Scoring Scale, objective International Knee Documentation Committee (IKDC) classification, Tegner Activity Scale, side-to-side difference in anterior tibial translation measured with KT-1000/2000 arthrometer, pivot shift test, tibiofemoral osteoarthritis grading on plain radiographs and subsequent knee surgeries. RESULTS: 8 studies (300 revision ACL reconstructions and 413 primary ACL reconstructions) were included in the meta-analysis. Patients who had had revision surgery reported inferior Lysholm Knee Scoring Scale scores (mean difference: 7.8 points), had inferior clinician-reported knee function as assessed with the objective IKDC classification (IKDC category A: 27% vs 57%; IKDC category C or D: 22% vs 8%) and pivot shift test (grade II or III: 7% vs 2%), and more radiographic evidence of tibiofemoral osteoarthritis (50% vs 25%) compared with patients who had had primary surgery. CONCLUSIONS: Revision ACL reconstruction restored similar anterior-posterior knee laxity compared with primary ACL reconstruction. Patients who had had revision surgery reported inferior Lysholm Knee Scoring Scale scores, had inferior clinician-reported knee function and more radiographic signs of tibiofemoral osteoarthritis compared with patients with primary ACL reconstruction.

High rate of implant loosening for uncemented resurfacing-type medial unicompartmental knee arthroplasty.

PURPOSE: To determine the medium-term implant survivorship, the clinical results and the failure mechanisms of a novel unicompartmental arthroplasty for uncemented resurfacing of the medial tibio-femoral compartment. METHODS: Seventy-six consecutive patients were prospectively evaluated with a mean final follow-up of 6 years (SD 5.3 months). In 44 patients, the diagnosis was osteoarthritis, and in 32 patients, it was avascular necrosis of the medial femoral condyle. The Hospital for Special Surgery Score was used for objective clinical evaluation, and a self-administered visual analogue scale was used to quantify residual pain at each observation point. Implant survivorship was determined assuming revision for any reason as endpoint. RESULTS: Nineteen patients were revised (6 with osteoarthritis and 13 with avascular necrosis of the medial femoral condyle). The mean interval time from index surgery to revision was 11.2 months (SD 4.66 months). Implant survivorship was higher in patients with osteoarthritis with respect to those with avascular necrosis of the medial femoral condyle (p = 0.018). Aseptic loosening was the most frequent failure mechanism. Femoral component loosening was reported in five patients and tibial component loosening was reported in other six patients. Assuming revision for any reason as endpoint, an implant survivorship of 74.3 % at 6-year follow-up was determined. In the remaining 57 patients, satisfactory clinical results were obtained. Hospital for Special Surgery Score and visual analogue scale for residual pain showed significant improvements (p < 0.03 and p < 0.045, respectively). CONCLUSIONS: At the present time, the standard cemented implants and the conventional designs for unicompartmental knee replacement still represent the optimal solution. The authors do not recommend the widespread use of this technique. LEVEL OF EVIDENCE: IV.

The adductor tubercle: an important landmark to determine the joint line level in revision total knee arthroplasty.

PURPOSE: The restoration of the physiological femoro-tibial joint line (JL) is important to obtain a good outcome in revision total knee arthroplasty (RTKA). However, its assessment is challenging. The ratio of the distance between the adductor tubercle (AT) JL (ATJL) and the trans-epicondylar femoral width (FW) was proposed as a reliable method. The purpose of this study was to check whether this ratio is a reliable tool to restore the prosthetic JL height in challenging prosthetic revision cases. METHODS: Twenty-one patients (mean age 65.8 years) were recruited. During surgery, FW was measured and ATJL distance was calculated using 0.53 (SD 0.03) as the ratio. After implant positioning, the obtained ATJL line was measured to verify the accuracy of the surgical procedure. Thirteen patients presented a healthy contralateral knee: a comparative radiograph examination was performed to verify the appropriateness of the restored JL height. RESULTS: The intra-operatively calculated ATJL was not significantly different with respect to the measured ATJL obtained after prosthetic component implantation. The comparative analysis between the restored JL and the JL of the contralateral not operated knee was also not statistically significant, thus confirming the appropriateness of the restored JL height. CONCLUSIONS: This study shows that the method which uses an AT to JL distance/FW ratio to determine the JL level, previously applied in primary TKA, is valid when using intra-operatively acquired measurements in RTKA. This is clinically relevant since it represents a reliable tool which helps surgeons to restore the JL level in challenging prosthetic revision cases. LEVEL OF EVIDENCE: Case series, Level IV.

Extramedullary hematopoiesis is associated with lower cardiac iron loading in chronically transfused thalassemia patients.

The aim of this study was to evaluate, in a large cohort of chronically transfused patients, whether the presence of extramedullary hematopoiesis (EMH) accounts for the typical patterns of cardiac iron distribution and/or cardiac function parameters. We retrospectively selected 1,266 thalassemia major patients who had undergone regular transfusions (611 men and 655 women; mean age: 31.3 ± 8.9 years, range: 4.2-66.6 years) and were consecutively enrolled within the Myocardial Iron Overload in Thalassemia network. The presence of EMH was evaluated based on steady-state free precession sequences; cardiac and liver iron overloads were quantified using a multiecho T2* approach; cardiac function parameters and pulmonary diameter were quantified using the steady-state free precession sequences; and myocardial fibrosis was evaluated using the late gadolinium enhancement technique. EMH was detected in 167 (13.2%) patients. The EMH+ patients had significantly lower cardiac iron overload than that of the EMH- patients (P = 0.003). The patterns of cardiac iron distribution were significantly different in the EMH+ and EMH- patients (P < 0.0001), with a higher prevalence of patients with no myocardial iron overload and heterogeneous myocardial iron overload and no significant global heart iron in the EMH+ group EMH+ patients had a significantly higher left ventricle mass index (P = 0.001) and a significantly higher pulmonary artery diameter (P = 0.002). In conclusion, in regularly transfused thalassemia patients, EMH was common and was associated with a thalassemia intermedia-like pattern of cardiac iron deposition despite regular transfusion therapy.

Accurate estimate of pancreatic T2* values: how to deal with fat infiltration.

PURPOSE: We examined different approaches aimed to deal with the signal fluctuation of pancreatic T2* values due to fat infiltration in order to obtain accurate estimates of iron overload. METHODS: Pancreatic T2* values were assessed in 20 patients (13 females, 37.24 ± 9.12 years) enrolled in the Myocardial Iron Overload in Thalassemia network without and with the application of fat suppression-FS (T2*-NoFS and T2*-FS). T2* values were assessed in three different ways: (1) from the immediate fit (original T2*); (2) discarding the echoes until the achievement of a good visual concordance between the signal and the model (final_vis T2*); (3) eliminating the echoes until the achievement of a fitting error (known) <5% (final_thres T2*). RESULTS: For the T2*-NoFS sequence the original T2* values were significantly higher than the final_vis T2* values (difference:4.8 ± 6.1 ms; P < 0.0001) and the final_thres T2* values (difference:4.3 ± 6.1 ms; P = 0.006). For the T2*-FS sequence the original T2* values were comparable to final_vis and final_thres T2* values. The original T2*-FS values were significantly different from the original T2*-NoFS values. The final_vis T2*-FS values were comparable to the final_vis T2*-NoFS values and the final_thresh T2*-FS values were comparable to the final_thresh T2*-NoFS values. For both T2*-FS and T2*-NoFS sequences, the final_thres T2* values were not significantly different from the final_vis T2* values and no bias was present. CONCLUSIONS: In the clinical practice, an accurate pancreatic iron overload assessment should be done by applying FS and, when needed, by discarding the TEs until the fitting error goes below 5%.

After revision anterior cruciate ligament reconstruction, who returns to sport? A systematic review and meta-analysis.

BACKGROUND: Return to sport and to pre-injury level represents an important outcome after both primary and revision anterior cruciate ligament (ACL) reconstructions. PURPOSE: The aim of the present meta-analysis was to determine the return to sport rate after revision ACL reconstruction. MATERIAL AND METHODS: A systematic search was performed of the MEDLINE, Embase and the Cochrane Central Register of Controlled Trials Databases. All the studies that reported return to sport, return to pre-injury sport level and return to high level/competitive sport was considered for the meta-analysis. The overall pooled mean of post-operative knee laxity and pooled rate of positive pivot-shift and objective International Knee Documentation Committee (IKDC) categories was calculated as well. RESULTS: Overall, 472 abstracts were identified and screened for inclusion and only 16 studies reported the rate of return to any level of sport activity at the final follow-up of 4.7 years (range 1.0-13.2 years), showing a pooled rate of 85.3% (CI 79.7 to 90.2). The return to pre-injury sport level was achieved in 53.4% (CI 37.8 to 68.7) of cases. Normal or quasi-normal objective IKDC, less than 5 mm of side-to-side difference at arthrometric evaluations and grade I-II pivot-shift test were reported in 84%, 88% and 93% patients, respectively. CONCLUSIONS: In spite of almost 8 patients out of 10 returning to sport after revision ACL reconstruction and showing good stability, only half of the patients returned to the same pre-injury sport level.

Biomechanical effect of posterolateral corner sectioning after ACL injury and reconstruction.

PURPOSE: Posterolateral corner structures functionally interact with the ACL. The aim of this study was to investigate the capability of an isolated ACL reconstruction control laxity parameters in a knee with combined ACL and PLC and the increase in terms of laxity produced by the resection of the PC in an ACL-deficient knee. METHOD: An in vitro cadaveric study was performed on seven knees. The joints were analysed in the following conditions: intact, after ACL resection, after popliteus complex resection, after ACL reconstruction and after LCL. Testing laxity parameters were recorded with an intra-operative navigation system and defined as: AP displacement at 30° and 90° of flexion (AP30 and AP90) applying a 130 N load and IE at 30° and 90° of knee flexion with a 5 N load. RESULTS: Sectioning the ACL significantly increased the AP30 at 30° and 90° of knee flexion (p < 0.05). At 90° of knee flexion, the resection of the LCL determined a significant increase in terms of AP laxity (p < 0.05). At 90° has been found a significant difference for the IE laxity (p < 0.05) after PC resection. Sectioning the LCL produced a significant increase in IE laxity at 30° and 90° of knee flexion (p < 0.05). CONCLUSION: Isolated ACL reconstruction is able to control the AP laxity with a combined complete lesion of the PLC at 30° of knee flexion, but not at higher angle of knee flexion. Considering the IE rotations, the reconstruction was not sufficient not even to control a partial lesion of the PLC. These findings suggest that additional surgical procedures should be considerate even when facing combined PLC lesion.

Three different cruciate-sacrificing TKA designs: minor intraoperative kinematic differences and negligible clinical differences.

PURPOSE: The goal of this study was to compare three types of mobile-bearing posterior cruciate ligament (PCL)-sacrificing TKA. The hypothesis was that the three designs provide differences in flexion stability and femoral rollback and improved clinical score at 2-year follow-up. METHODS: Three groups of patients, divided according to implant design, were analysed retrospectively. All operations were guided by a non-image-based navigation system that recorded relative femoral and tibial positions in native and implanted knees during: passive range of motion and anterior drawer test at 90° flexion. WOMAC, KSS and SF36 scores were collected pre-operatively and at 2-year follow-up. RESULTS: There are no differences in kinematic or clinical performance of the three implants, except for the antero-posterior translation during stress test in flexion: only Cohort B had comparable pre- and post-operative laxity test values (p < 0.001). All three TKA designs allowed to maintain pre-operative tibial rotation pattern through all range of knee flexion. All clinical scores of the three patient cohorts were significantly improved post-operatively compared to the pre-operative values (p < 0.001). Moreover, we found no differences among post-operative results of the three designs. CONCLUSION: Despite design variations, mobile-bearing PCL-sacrificing TKA reproduces femoral rollback and screw-home with little or no difference in clinical or functional scores at a follow-up of 2 years. LEVEL OF EVIDENCE: III.

Can rotatory knee laxity be predicted in isolated anterior cruciate ligament surgery?

PURPOSE: Despite the overall success of the surgical anterior cruciate ligament (ACL) reconstruction, some patients still present with instability symptoms even after the surgery, mainly due to the presence of associated lesions. At present, the pivot shift test has been reported to be the benchmark to assess rotatory knee laxity. The purpose of this study was to quantitatively evaluate rotatory knee laxity at time-zero in order to determine whether detected post-reconstruction laxity was predictable by its value measured before the reconstruction, which was hypothized to be influenced by the presence of associated lesions. METHODS: Rotatory knee laxity was retrospectively analysed in 42 patients, including two different ACL reconstructions. The maximal anterior displacement and the absolute value of the posterior acceleration reached during the reduction of the tibial lateral compartment were intra-operatively acquired by using a navigation system and identified as discriminating parameters. For each parameter, statistical linear regression analysis (line slope and intercept) was performed between pre- and post-reconstruction values. RESULTS: No statistically significant influence of the initial posterior acceleration on the post-reconstruction outcome was found (line slope, p > 0.05), although a statistically significant line intercept was indeed identified (p < 0.001). A statistically significant influence on the surgery outcome was instead found for the initial value of the anterior tibial displacement (line slope = 0.39, p = 0.004), meaning that, on average, about 40 % of the post-reconstruction lateral compartment displacement could be explained by the corresponding pre-reconstruction value. Both of these findings highlighted the importance of intra-operative quantification of rotatory knee laxity to identify correct indications for the surgery. CONCLUSIONS: This study provided important implications for the future possibility of defining a quantifying tool able to assess rotatory knee laxity during ACL reconstruction. This could allow detection of additional injuries to secondary restraints by easily performing rotatory knee laxity tests, which in turn could reduce post-surgical recurrence of knee instability.

The Perlman syndrome: familial renal dysplasia with Wilms tumor, fetal gigantism and multiple congenital anomalies. 1984.

INTRODUCTION: The ensuing paper by Professor Giovanni Neri and colleagues was originally published in 1984, American Journal of Medical Genetics 19:195­207. The original article described a new family with a condition that the authors designated as the Perlman syndrome. This disorder, while uncommon, is an important multiple congenital anomaly and dysplasia syndrome; the causative gene was recently identified. This paper is a seminal work and is graciously republished by Wiley-Blackwell in the Special Festschrift issue honoring Professor Neri. We describe a familial syndrome of renal dysplasia, Wilms tumor, hyperplasia of the endocrine pancreas, fetal gigantism, multiple congenital anomalies and mental retardation. This condition was previously described by Perlman et al. [1973, 1975] and we propose to call it the "Perlman syndrome." It appears to be transmitted as an autosomal recessive trait. The possible relationships between dysplasia, neoplasia and malformation are discussed.

The 25-year experience of over-the-top ACL reconstruction plus extra-articular lateral tenodesis with hamstring tendon grafts: the story so far.

This article presents with an evidence based approach, the kinematical rationale, biological evidence and the long term results of the "Over-The-Top" anterior cruciate ligament reconstruction with lateral plasty technique. This surgery was developed more than 25 years ago at the Rizzoli Institute by professor Marcacci and Zaffagnini and it is still widely performed in many orthopedic center worldwide.

Piezoelectric ultrasonic debridement as new tool for biofilm removal from orthopedic implants: A study in vitro.

Pulse lavage (PL) debridement is the standard treatment used in Debridement, Antibiotics and Implant Retention (DAIR) for bacterial biofilm removal during acute and early postoperative cases of periprosthetic joint infection (PJI). The failure rate of DAIR is still high due to the inadequacy of PL in removing the biofilm. Ultrasound-based techniques are a well-established tool for PJI diagnosis due to their ability to completely eradicate the biofilm from implant surfaces. Hence, this study investigates the efficiency of a piezoelectric ultrasonic scalpel (PUS) in removing bacterial biofilm from different orthopedic implant materials in vitro and compares the results with PL. Biofilms of methicillin-resistant Staphylococcus aureus strains were grown on titanium alloy (Ti6Al4V ELI), stainless steel (AISI 316L), and ultrahigh molecular weight polyethylene (UHMWPE) disks for 24 h. The disks of each material were divided into three groups: (i) a control group (no lavage/debridement), (ii) a group treated with PL, (iii) a group treated with PUS. The disks were then sonicated for viable cell count to measure the residual biofilm content. Compared to the initial cell count (105 CFU/mL for each material), PL showed a two-log reduction of CFU/mL (p < 0.001 for each material), while for PUS a four-log reduction was found (p < 0.001 for each material). The comparison between the two lavage/debridement displayed a two-log reduction of CFU/mL (p < 0.001 for each material) of PUS compared with PL. Its increased efficiency compared with PL promotes the use of PUS in removing bacterial biofilm from orthopedic implants, suggesting its implementation to improve the success rate of DAIR.