A Comparative Analysis of Perioperative Complications in Octogenarians and Patients under 60 Years of Age after Primary Cemented Total Knee Arthroplasty.

Introduction: Knee arthroplasty is exposed to demographic changes as patients age. An analysis of risk factors for surgical treatment decisions in patients over 80 years old is crucial. This study compared perioperative complications between groups of patients undergoing primary knee arthroplasty, under 60 years old and over 80 years old.Materials and Methods: For this retrospective study, data from 400 patients with primary cemented bi- and unicondylar total knee endoprosthesis during inpatient stay from 2017 to 2018 were analyzed. Patients aged 61-79 years (257) were excluded. An analysis of the remaining 143 patients was performed. The incidence of surgery-related and systemic complications (eg, urinary tract infections, electrolyte imbalances, and cases of pneumonia), the blood supply and C-reactive protein (CRP) as well as hemoglobin progression were compared across both age groups. Furthermore, a correlation between prevalent diseases and systemic complications were investigated. Statistical analysis was performed using IBM SPSS (Armonk, US).Results: Data analyses showed a significant difference in the occurrence of systemic complications and blood transfusion between the age groups (P = 0.001, phi = 0.44; phi= 0.55, P = 0.001). Surgical complications did not differ significantly between the age groups. Age-typical pre-existing conditions, especially arterial hypertension (P = 0.003), showed a significant association with the occurrence of systemic complications. In addition, high postoperative CRP values in elderly patients revealed an association to systemic complications (P = 0.008).Discussion and Conclusion: The study shows that primary cemented knee arthroplasty is a safe procedure without an increased incidence of surgical complications, even in elderly patients. The increased incidence of internal complications in octogenarians, in turn, should receive more attention in the perioperative course. The interdisciplinary preoperative optimization of pre-existing conditions and drug therapy, as well as close interdisciplinary assessments of elderly patients, should be ensured.

Same-gender differences in perioperative complications and transfusion management for lower limb arthroplasty.

INTRODUCTION: Total hip (THA) and knee arthroplasty (TKA) are surgical interventions for patients with primary and posttraumatic osteoarthritis. The present clinical investigation compared gender differences in THA and TKA. METHODS: Data from 419 patients following primary THA and TKA were collected. The occurrence of systemic and surgery-related complications, the units of blood transfused, and the change in Hb were investigated. Hb was collected preoperatively and at 1, 2, 4 and 7 days postoperatively. Statistical analysis was performed using the software IBM SPSS 28. RESULTS: There was no significant difference in surgery-related and general complications in men between THA and TKA. A significant difference between THA and TKA in systemic complications in women was observed. No significant difference between THA and TKA in related to surgery-related complications was evidenced. In men, no difference in Hb progression was observed. In women, a significant Hb drop was evidenced (p = 0.03). The rate of blood transfusion units in women was significantly greater in TKA than in THA (p = 0.001). No statistically significant difference was observed in men in the rate of transfusion between THA and TKA. CONCLUSION: Perioperative care should be organized differently for women and men. Furthermore, a differentiation between the procedures for each sex could prevent the occurrence of perioperative complicated courses.

Analysis of gender differences with traditional posterior stabilized versus kinematic designs in total knee arthroplasty.

INTRODUCTION: Total knee arthroplasty (TKA) is a good treatment for end-stage knee osteoarthritis (KOA). Approximately 60% of the patients are females, and 40% are males. This study analyzed pre- and postoperative angle differences in the range of motion (ROM), and the occurrence of complications with traditional posterior stabilization versus kinematic TKA in relation to gender. METHODS: Data from 434 patients with primary cemented total knee arthroplasty from 2018 to 2021 were collected. Alpha and beta angles were determined pre- and postsurgery. The ROM was collected pre- and postoperatively and during follow-up. Additionally, perioperative complications, revision rate, and blood transfusion management were investigated. RESULTS: The pre- and postoperative alpha-angle between men and women was significantly different, as was the level of alpha-angle correction between men and women (p = 0.001; p = 0.003). Same-gender differences in pre- to postoperative alpha-angles between traditional and kinematic TKA were shown (women (w): p = 0.001; men (m); p = 0.042). High postoperative alpha angles led to less ROM in traditional TKA for women (p = 0.008). No significant gender differences in ROM, perioperative complications, or revision surgery and transfusion rates were found. CONCLUSION: Despite high gender differences in pre- and postoperative angles, only female patients with traditional arthroplasty and high postoperative alpha angles showed less ROM in the follow-up. This leads to the assumption that gender-related pre- and postoperative angle differences, and the degree of angle correction, do not influence the ROM or perioperative occurrence of complications. Both designs present safe procedures for both genders with a wide spectrum of axis deformities.

The Adherence of Digital Templating of Cemented Bicondylar Total Knee Arthroplasty Reveals Gender Differences.

INTRODUCTION: Preoperative digital templating is a standard procedure that should help the operating surgeon to perform an accurate intraoperative procedure. To date, a detailed view considering gender differences in templating total knee arthroplasty (TKA), stage of arthrosis, and the surgeons' experience altogether has not been conducted. METHODS: A series of 521 patients who underwent bicondylar total knee arthroplasty was analyzed retrospectively for the planning adherence of digital templating in relation to sex, surgeon experience, and stage of arthrosis. Pre- and postoperative X-rays were comparably investigated for planned and implanted total knee arthroplasties. Digital templating was carried out through mediCAD version 6.5.06 (Hectec GmbH, 84032 Altdorf, Germany). For statistical analyses, IBM SPSS version 28 (IBM, 10504 Armonk, NY, US) was used. RESULTS: The general planning adherence was 46.3% for the femur and 41.8% for the tibia. The Mann-Whitney U test revealed a gender difference for templating the femur (z = -5.486; p ≤ 0.001) and tibia (z = -3.139; p = 0.002). The surgeon's experience did not show a significant difference through the Kruskal-Wallis test in the femur (K-W H = 4.123; p = 0.127) and the tibia (K-W H = 2.455; p = 0.293). The stage of arthrosis only revealed a significant difference in the planning of the femur (K-L-score (K-W H = 6.516; p = 0.038) alone. DISCUSSION/CONCLUSION: Digital templating for total knee arthroplasty brought up gender differences, with oversized implants for women and undersized implants for men. A high stage of femoral arthrosis can lead to the under and oversized planning of the surgeon. Since the surgeon's experience in planning did not show an effect on the adherence to templating, the beneficial effect of digital templating before surgery should be discussed.

Prognostic factors for the management of chondral defects of the knee and ankle joint: a systematic review.

PURPOSE: Different surgical techniques to manage cartilage defects are available, including microfracture (MFx), autologous chondrocyte implantation (ACI), osteoarticular auto- or allograft transplantation (OAT), autologous matrix-induced chondrogenesis (AMIC). This study investigated the patient-related prognostic factors on the clinical outcomes of surgically treated knee and ankle cartilage defects. METHODS: This study followed the PRISMA statement. In May 2022, the following databases were accessed: PubMed, Google Scholar, Embase, and Scopus. All the studies investigating the outcomes of surgical management for knee and/or talus chondral defects were accessed. Only studies performing mesenchymal stem cells transplantation, OAT, MFx, ACI, and AMIC were considered. A multiple linear model regression analysis through the Pearson Product-Moment Correlation Coefficient was used. RESULTS: Data from 184 articles (8905 procedures) were retrieved. Female sex showed a positive moderate association with visual analogue scale at last follow-up (P = 0.02). Patient age had a negative association with the American Orthopaedic Foot and Ankle Score (P = 0.04) and Lysholm Knee Scoring Scale (P = 0.03). BMI was strongly associated with graft hypertrophy (P = 0.01). Greater values of VAS at baseline negatively correlate with lower values of Tegner Activity Scale at last follow-up (P < 0.0001). CONCLUSION: The clinical outcomes were mostly related to the patients' performance status prior surgery. A greater BMI was associated with greater rate of hypertrophy. Female sex and older age evidenced fair influence, while symptom duration prior to the surgical intervention and cartilage defect size evidenced no association with the surgical outcome. Lesion size and symptom duration did not evidence any association with the surgical outcome.

The risk analysis of perioperative complications of cementless hip arthroplasty in octogenarians.

INTRODUCTION: Hip arthroplasty is exposed to demographic change as patients age. Analysis of risk factors for surgical treatment decisions in the group of ≥ 80-year-old patients is crucial. Healthcare systems in developed countries are being tested medically and financially by the ageing population. Therefore, this study analysed the perioperative complications of cementless primary hip arthroplasty in octogenarians and compared them with patients aged ≤ 60 years. METHODS: A retrospective data analysis of the year 2017 was done in a maximum care hospital of General Orthopaedic Surgery. Patients aged ≥ 80 years or ≤ 60 years with primary cementless hip arthroplasty were included. The outcome of interest was surgery-related and systemic complications, the development of haemoglobin and the incidence of blood transfusion after cementless primary hip arthroplasty in octogenarians during the hospitalisation and the follow-up treatment. Chi-square tests and Fischer's exact test were used for nominal variables. The two-factorial variance analysis-mixed model was used for Hb analyses and the Welch test for group comparison for metric parameters. RESULTS: There was a significantly increased incidence of systemic complications during hospitalisation in the ≥ 80-year-old patients (phi 0.26; Std. Ri - 0.8 (A), 2.2 (B); p = 0.007), as well as a significantly increased rate of blood transfusions (phi 0.403; Std. Ri - 1.3 (A), 3.2 (B); p = < 0.001). No clustered pre-existing conditions in the ≥ 80-year-old patients pointed out a significant association with the incidence of systemic complications. Surgery-related complications showed no significant difference during hospitalisation and follow-up treatment. CONCLUSION: The study reveals that primary cementless hip prosthesis implantation is a safe procedure without increased incidence of surgery-related complications. Increased attention should be paid to interdisciplinary preoperative optimisation (adjustment of blood pressure, blood transfusions, if necessary, safe exclusion of urinary tract infections) and postoperative care of octogenarians (tight laboratory examinations, geriatric co-attendance).

Fixation of the Membrane during Matrix-Induced Autologous Chondrocyte Implantation in the Knee: A Systematic Review.

Introduction: It is unclear whether the type of membrane used for matrix-assisted autologous chondrocyte implantation (mACI) influences results. A systematic review was conducted to investigate the midterm results of the three most common types of membrane fixation for mACI. Methods: This systematic review was conducted according to the 2020 PRISMA checklist. PubMed, Google Scholar, Embase, and Scopus online databases were accessed in August 2022. All the prospective clinical trials reporting outcomes of mACI in the knee were considered. Studies that describe the modality of membrane fixation (glued, glued, and sutured, no fixation) used for mACI were eligible. Studies that conducted a minimum of 12 months of follow-up were considered. The outcomes of interest were the Tegner Activity Scale and International Knee Documentation Committee (IKDC) score. The rate of failure and revisions were also collected. Results: Data from 26 studies (1539 procedures; 554 of 1539 (36%) were women) were retrieved. The mean follow-up was 42.6 (12 to 84) months. No difference between the groups was found in terms of mean duration of symptoms, age, BMI, gender, and defect size (P > 0.1). No difference was found in terms of the Tegner score (P = 0.3). When no fixation was used, a statistically significant higher IKDC compared to the other groups (P = 0.02) was evidenced. No difference was found in the rate of failure (P = 0.1). The no-fixation group evidenced a statistically significant lower rate of revisions (P = 0.02). Conclusions: No membrane fixation for mACI in the knee scored better than the fastening techniques at the midterm follow-up.

Matrix-induced autologous chondrocyte implantation (mACI) versus autologous matrix-induced chondrogenesis (AMIC) for chondral defects of the knee: a systematic review.

INTRODUCTION: Chondral defects of the knee are common and their treatment is challenging. SOURCE OF DATA: PubMed, Google scholar, Embase and Scopus databases. AREAS OF AGREEMENT: Both autologous matrix-induced chondrogenesis (AMIC) and membrane-induced autologous chondrocyte implantation (mACI) have been used to manage chondral defects of the knee. AREAS OF CONTROVERSY: It is debated whether AMIC and mACI provide equivalent outcomes for the management of chondral defects in the knee at midterm follow-up. Despite the large number of clinical studies, the optimal treatment is still controversial. GROWING POINTS: To investigate whether AMIC provide superior outcomes than mACI at midterm follow-up. AREAS TIMELY FOR DEVELOPING RESEARCH: AMIC may provide better outcomes than mACI for chondral defects of the knee. Further studies are required to verify these results in a clinical setting.

AMIC for traumatic focal osteochondral defect of the talar shoulder: a 5 years follow-up prospective cohort study.

BACKGROUND: Autologous Matrix-Induced Chondrogenesis (AMIC) is addressed to osteochondral defects of the talus. However, evidence concerning the midterm efficacy and safety of AMIC are limited. This study assessed reliability and feasibility of AMIC at 60 months follow-up. We hypothesize that AMIC leads to good clinical outcome at midterm follow-up. METHODS: Surgeries were approached with an arthrotomy via malleolar osteotomy. A resorbable porcine I/III collagen membrane (Chondro-Gide®, Geistlich Pharma AG, Wolhusen, Switzerland) was used. Patients were followed at 24 and 60 months. The primary outcome of interest was to analyse the Foot Function Index (FFI), and the subscale hindfoot of the American Orthopaedic Foot and Ankle Score (AOFAS). Complications such as failure, revision surgeries, graft delamination, and hypertrophy were also recorded. The secondary outcome of interest was to investigate the association between the clinical outcome and patient characteristics at admission. RESULTS: Data from 19 patients were included. The mean age at admission was 47.3 ± 13.2 years, and the mean BMI 24.1 ± 4.9 kg/m2. 53% (10 of 19 patients) were female. At a mean of 66.2 ± 11.6 months, the FFI decreased at 24-months follow-up of 22.5% (P = 0.003) and of further 1.3% (P = 0.8) at 60-months follow-up. AOFAS increased at 24-months follow-up of 17.2% (P = 0.003) and of further 3.4 (P = 0.2) at 60-months follow-up. There were two symptomatic recurrences within the follow-up in two patients. There was evidence of a strong positive association between FFI and AOFAS at baseline and the same scores last follow-up (P = 0.001 and P = 0.0002, respectively). CONCLUSION: AMIC enhanced with cancellous bone graft demonstrated efficacy and feasibility for osteochondral defects of the talus at five years follow-up. The greatest improvement was evidenced within the first two years. These results suggest that clinical outcome is influenced by the preoperative status of the ankle. High quality studies involving a larger sample size are required to detect seldom complications and identify prognostic factors leading to better clinical outcome. LEVEL OF EVIDENCE: II, prospective cohort study.

Live In-Vivo Neuroimaging Reveals the Transport of Lipophilic Cargo Through the Blood-Retina Barrier with Modified Amphiphilic Poly-N-Vinylpyrrolidone Nanoparticles.

The blood-retina barrier (BRB), analogous to the blood-brain barrier, is a major hurdle for the passage of drugs from the blood to the central nervous system. Here, we designed polymeric nanoparticles from amphiphilic poly-/V-vinylpyrrolidone (Amph-PVP NPs) as a new carrier-system and investigated their ability to pass the BRB using a live In-Vivo neuroimaging system for the retina in rats and ex-vivo wholemounted retinae preparation. Amph-PVP NPs were loaded with hydrophobic fluorescent markers as a surrogate for hydrophobic drugs. Linking these NPs with the hydrophobic fluorescence marker Carboxyfluorescein-succinimidyl-ester (CFSE) to the surface, induced the passage of the cargo into the retina tissue. In particular, we observed a substantial internalization of the CFSE-linked NPs into blood cells. We propose surface- modified Amph-PVP NPs as a potential new nano-carrier platform to target posterior eye and potentially brain diseases while camouflaged by blood cells.

AMIC for Focal Osteochondral Defect of the Talar Shoulder.

BACKGROUND: The management of a focal osteochondral lesion of the talus (OLT) is challenging. Evidence concerning the role of the autologous matrix-induced chondrogenesis (AMIC) procedure in patients with focal OLT is promising. The purpose of the present study was to investigate clinical outcomes and radiographic findings of the AMIC technique for focal unipolar OLT. MATERIAL AND METHODS: The present study was performed according to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines. Twenty-four patients who underwent AMIC for focal OLT were prospectively recruited at our institution. All the surgeries were performed by two experienced surgeons through malleolar osteotomy and autologous cancellous bone grafting. The outcomes of interest were the American orthopedic foot and ankle score (AOFAS), the foot-function index (FFI), and the magnetic resonance observation of cartilage repair tissue (MOCART). Surgical duration, hospitalization length, and complications were also collected. RESULTS: 24 patients were included in the present study. The mean follow-up was 25.17 ± 13.1 months. The mean age of the patients at surgery was 46.75 ± 15.2 years, the mean BMI 26.92 ± 5.7 kg/m2, and 50% (12 of 24) of patients were female. The right ankle was involved in 62.5% (15 of 24) of patients. The mean defect size was 6.95 ± 2.9 mm2. The mean surgical duration was 112 ± 20 min while the mean hospitalization 5.58 ± 1.7 days. At last follow-up, the AOFAS increased by 27.8 points (p < 0.0001), while the FFI reduced by 25.3 points (p < 0.0001) and the MOCART score increased by 28.33 points (p < 0.0001). No complications were observed. CONCLUSION: The AMIC procedure for focal osteochondral defects of the talar shoulder is feasible and reliable at midterm follow-up.

Reverse augmentation technique in hip revision arthroplasty: a new strategy for the management of acetabular reconstruction.

BACKGROUND: The principle of acetabular total hip revision (THR) is based on acetabular reconstruction and restoration of the center of rotation. The use of augmentation in high cranial acetabular defects combined with a cementless revision shell was studied sufficiently. This study aimed to report a case with the use of an augment inside a cementless revision shell as a reverse augmentation technique. METHODS: We describe the case of an 86-year-old female patient with a massive acetabular defect during second revision for total hip arthroplasty (THA). Two problems occurred: (1) a fixed cemented stem with a nonmodular head size of 33 mm and (2) a high acetabular defect with an elevated rotation center. RESULTS: With the distraction technique, allograft filling was used to reconstruct the acetabular defect. A cementless revision shell (REDAPT, Smith and Nephew) with a size of 78 mm was used to stabilize the defect. Locking screws placed cranially and distally were used to stabilize the cup for secondary osseointegration. An augment was placed inside the cup to reconstruct the rotation center. A customized polyethylene liner (outer diameter, 54 mm/inner diameter, 33 mm) was positioned below the augment in the revision cup to reconstruct the center of rotation. An 18-month postoperative X-ray analysis showed a stable construct with full secondary osseointegration. CONCLUSION: This is the first report of an augment used for a reverse technique inside a cementless shell to restore the center of rotation with the use of a customized polyethylene liner. This might be a reliable option for reconstruction of the center of rotation in large cementless revision cups in acetabular Paprosky type III defects. This technical note shows the possibility of using an augment as a reverse technique in a cementless revision cup.

Live-cell Imaging and Quantitative Analysis of Meiotic Divisions in Caenorhabditis elegans Males.

Live-imaging of meiotic cell division has been performed in extracted spermatocytes of a number of species using phase-contrast microscopy. For the nematode Caenorhabditis elegans, removal of spermatocytes from gonads has damaging effects, as most of the extracted spermatocytes show a high variability in the timing of meiotic divisions or simply arrest during the experiment. Therefore, we developed a live-cell imaging approach for in situ filming of spermatocyte meiosis in whole immobilized C. elegans males, thus allowing an observation of male germ cells within an unperturbed environment. For this, we make use of strains with fluorescently labeled chromosomes and centrosomes. Here we describe how to immobilize male worms for live-imaging. Further, we describe the workflow for the acquisition and processing of data to obtain quantitative information about the dynamics of chromosome segregation in spermatocyte meiosis I and II. In addition, our newly developed approach allows us to re-orient filmed spindles in silico, regardless of the initial 3D orientation in the worm, and analyze spindle dynamics in living worms in a statistically robust manner. Our live-imaging approach is also applicable to C. elegans hermaphrodites and should be expandable to other fluorescently labelled nematodes or other fully transparent small model organisms.

Wide-Field Multi-Parameter FLIM: long-term minimal invasive observation of proteins in living cells.

Time-domain Fluorescence Lifetime Imaging Microscopy (FLIM) is a remarkable tool to monitor the dynamics of fluorophore-tagged protein domains inside living cells. We propose a Wide-Field Multi-Parameter FLIM method (WFMP-FLIM) aimed to monitor continuously living cells under minimum light intensity at a given illumination energy dose. A powerful data analysis technique applied to the WFMP-FLIM data sets allows to optimize the estimation accuracy of physical parameters at very low fluorescence signal levels approaching the lower bound theoretical limit. We demonstrate the efficiency of WFMP-FLIM by presenting two independent and relevant long-term experiments in cell biology: 1) FRET analysis of simultaneously recorded donor and acceptor fluorescence in living HeLa cells and 2) tracking of mitochondrial transport combined with fluorescence lifetime analysis in neuronal processes.

The Modular Universal Tumour And Revision System (MUTARS®) in endoprosthetic revision surgery.

The aim of this study was to present the clinical and functional results of revision surgery after failed hip endoprostheses using the Modular Universal Tumour And Revision System (MUTARS®). Functional results of the hip endoprostheses were recorded by applying the Harris hip score. The extent of the presurgical radiological bone defect was measured according to the classification system of the German orthopaedic association (DGOOC). Indications for revision surgery on 45 patients (21 female, 24 male) were aseptic loosening (19 patients), infection (16 patients), or periprosthetic fracture (Vancouver classification B2, B3 and C, in nine patients). Revision surgery was performed after 8.6 years on average (min. 0.6; max. 14.25 years). Large defects of the proximal femur (80% medial or lateral diaphysis; 20% meta-diaphysis according to DGOOC classification) were adequately reconstructed. The average follow-up was 38.6 months. Complications occurred in eight patients: one luxation, two aseptic loosenings, and five reinfections were diagnosed. The Harris hip score (presurgical 30; postsurgical 78) showed significant improvement after revision surgery. Regarding the extent of the patients' bone defects, good functional results were achieved. The comparatively low number of luxations and loosenings is due to the high modularity of the prosthesis with arbitrary antetorsion in the hip joint. However, high reinfection rates in mega-implants still constitute a problem and should be the subject of further studies.

Is there a need of custom-made prostheses for total hip arthroplasty? Gait analysis, clinical and radiographic analysis of customized femoral components.

INTRODUCTION: Custom-made prosthesis in primary hip arthroplasty based on the concept of a better press-fitting to reach superior clinical results in comparison to conventional implants. Mid-term results provide a more complete picture with respect to gait and electromyographic analyses. MATERIALS AND METHODS: The custom-made femoral component (Adaptiva) was implanted in 24 hips and compared to 23 hips with a conventional implant (Alloclassic-SL). The mean retrospective follow-up times were 3.9 (3-4.9) years and 4.8 (3.1-5.1) years. Clinically, the Harris Hip Score (HHS) and the SF 36 were recorded. Motion analysis data (body kinematics, kinetics and muscle activities) were recorded with 3D gait analysis. RESULTS: Neither the HHS nor the SF-36 revealed any statistical differences between the two groups (P > 0.05). The radiographic parameters did not show the intended physiologic load transfer. Periprosthetic changes indicated a more distal load transfer of the customized stem. Gait analysis revealed in comparison to the controls (45.03 degrees ), a reduced mean hip range of motion in the sagittal plane by 11.4% (39.9 degrees ) in the customized stem group versus 17.4% (37.2 degrees ) in the conventional stem group. In keeping with the limited range of hip motion kinematic impairments of the ipsilateral knee and ankle joints were detected. The electromyographic amplitudes of the tensor fasciae latae and gluteus medius muscles both for stabilizing the hip joint in the stance phase were significantly higher in both groups. CONCLUSION: Compared to a conventional cementless hip prosthesis the custom-made device did not improve the mid-term clinical and radiographic outcome. Despite the individualized reconstruction of the biomechanical hip geometry objective gait analysis failed to show a benefit.

Long-term results of arthroscopic Bankart repair with a bioabsorbable tack.

BACKGROUND: Short-term to midterm data are available on arthroscopic shoulder stabilization using bioabsorbable tacks or suture anchors. It remains unknown whether these techniques can equal the success of open Bankart repair in the long term. PURPOSE: To assess the long-term outcome of arthroscopic Bankart repair using bioabsorbable tacks in patients with traumatic anterior shoulder instability with a minimum follow-up of 7 years. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Treatment outcomes were determined prospectively according to the Rowe score and retrospectively according to the Constant and American Shoulder and Elbow Surgeons scores. Included in this study were 18 consecutive patients with a mean age of 26.8 years (range, 16-62 years) who underwent arthroscopic Bankart repair using bioabsorbable tacks for traumatic anterior shoulder instability. The study group consisted of 14 male and 4 female patients. The mean follow-up was 8.7 years (range, 7.0-9.8 years). RESULTS: One patient had recurrent dislocations requiring further surgery, for an overall failure rate of 5.6%. An additional patient had 1 traumatic subluxation episode within the first postoperative year that did not recur. According to the Rowe score, which increased to 90.3 (17.8) from 32.8 (8.3) points preoperatively, 15 patients (83.3%) achieved a good or excellent result. The mean Constant score was 91.3 (SD, 6.9) points, and the mean American Shoulder and Elbow Surgeons score was 92.1 (SD, 6.9) points postoperatively. A return to the preinjury level of sports competition was reported by 64% of patients. No signs of synovitis occurred in any patient postoperatively. CONCLUSION: Arthroscopic Bankart repair for the treatment of recurrent traumatic anterior shoulder instability repair using bioabsorbable tacks offers reliable results with respect to failure rate, range of motion, and shoulder function during a minimum follow-up of 7.0 years. In contrast to previous reports on arthroscopic Bankart repair, results did not deteriorate during follow-up.

Rasterstereographic analysis of axial back surface rotation in standing versus forward bending posture in idiopathic scoliosis.

The forward bending test according to Adams and rib hump quantification by scoliometer are common clinical examination techniques in idiopathic scoliosis, although precise data about the change of axial surface rotation in forward bending posture are not available. In a pilot study the influence of leg length inequalities on the back shape of five normal subjects was clarified. Then 91 patients with idiopathic scoliosis with Cobb-angles between 20 degrees and 82 degrees were examined by rasterstereography, a 3D back surface analysis system. The axial back surface rotation in standing posture was compared with that in forward bending posture and additionally with a scoliometer measurement in forward bending posture. The changes of back shape in forward bending posture were correlated with the Cobb-angle, the level of the apex of the scoliotic primary curve and the age of the patient. Averaged over all patients, the back surface rotation amplitude increased from 23.1 degrees in standing to 26.3 degrees in forward bending posture. The standard deviation of this difference was high (6.1 degrees ). The correlation of back surface rotation amplitude in standing with that in forward bending posture was poor (R (2)=0.41) as was the correlation of back surface rotation in standing posture with the scoliometer in forward bending posture measured rotation (R (2)=0.35). No significant correlation could be found between the change of back shape in forward bending and the degree of deformity (R (2)=0.07), likewise no correlation with the height of the apex of the scoliosis (R (2)=0.005) and the age of the patient (R (2)=0.001). Before forward bending test leg length inequalities have to be compensated accurately. Compared to the standing posture, forward bending changes back surface rotation. However, this change varies greatly between patients, and is independent of the type and degree of scoliosis. Furthermore remarkable differences were found between scoliometer measurement of the rib hump and rasterstereographic measurement of the vertebral rotation. Therefore the forward bending test and the identification of idiopathic scoliosis rotation by scoliometer can be markedly different compared to rasterstereographic surface measurement in the standing posture.

CT-based accuracy of implanting custom-made endoprostheses.

BACKGROUND: To optimize physiological load transfer and mechanical stability a close geometric fit between cementless stems and the bone stock is essential. To solve the problem of a geometric mismatch between the anatomic shape of the femoral canal and conventional stems custom-made implants were developed. This study determined the accuracy of implanting custom-made press-fit straight femoral stems compared to conventional cementless stems. METHODS: Nine pairs of human cadaveric femurs were used to determine the extent of the endocortical area in contact with the stem. The bone-femoral component interface was measured in vitro using CT-data analysis. A software program was developed to describe the periprosthetic inner cortical bone structure, the stem surface and the proportionate implant-endosteal bone contact. FINDINGS: The mean endosteal bone contact of both prostheses was 21.6%. The proportionate implant-endosteal bone contact for straight custom-made femoral prostheses averaged 20.98%. For the conventional cementless stems the mean proportionate contact was 22.15%. Especially in the proximal femur the desirable contact of customized implants was not achieved by closed distal press-fit. INTERPRETATION: Compared to conventional straight cementless stems custom-made stems did not extend the endocortical contact area. The desirable "fit and fill" of the proximal femur was not achieved with straight custom-made femoral components in femurs of regular geometry.