Concomitant glenohumeral pathologies in high-grade acromioclavicular separation (type III - V).

BACKGROUND: Acromioclavicular joint (ACJ) dislocations are common injuries of the shoulder associated with physical activity. The diagnosis of concomitant injuries proves complicated due to the prominent clinical symptoms of acute ACJ dislocation. Because of increasing use of minimally invasive surgery techniques concomitant pathologies are diagnosed more often than with previous procedures. METHODS: The aim of this study was to identify the incidence of concomitant intraarticular injuries in patients with high-grade acromioclavicular separation (Rockwood type III - V) as well as to reveal potential risk constellations. The concomitant pathologies were compiled during routine arthroscopically assisted treatment in altogether 163 patients (147 male; 16 female; mean age 36.8 years) with high-grade acromioclavicular separation (Rockwood type III: n = 60; Rockwood type IV: n = 6; Rockwood type V: n = 97). RESULTS: Acromioclavicular separation occurred less often in women than men (1:9). In patients under 35, the most common cause for ACJ dislocation was sporting activity (37.4%). Rockwood type V was observed significantly more often than the other types with 57.5% (Rockwood type III = 36.8%, Rockwood type IV 3.7%). Concomitant pathologies were diagnosed in 39.3% of the patients with that number rising to as much as 57.3% in patients above 35 years. Most common associated injuries were rotator cuff injuries (32.3%), chondral defects (30.6%) and SLAP-lesions (22.6%). Of all patients, 8.6% needed additional reconstructive surgery. CONCLUSION: Glenohumeral injuries are a much more common epiphenomenon during acromioclavicular separation than previously ascertained. High risk group for accompanying injuries are patients above 35 years with preexisting degenerative disease. The increasing use of minimally invasive techniques allows for an easier diagnosis and simultaneous treatment of the additional pathologies.

Stimulation with bone morphogenetic protein-2 (BMP-2) enhances bone-tendon integration in vitro.

PURPOSE: Preclinical studies have reported that bone morphogenetic protein (BMP)-2 promotes bone-tendon healing following anterior cruciate ligament reconstruction. We examined the region-specific effects of BMP-2 on osteoblast and fibroblast differentiation in a highly standardized murine in vitro co-culture model of bone-tendon integration. MATERIALS AND METHODS: We used quantitative PCR to measure the dose- and time-dependent influence of BMP-2 on the expression of alkaline phosphatase, osteocalcin, collagen type 1 (alpha 1 chain), runt-related transcription factor 2, osteopontin, collagen type 1 (alpha 2 chain), collagen type 5 (alpha 1 chain), decorin, fibromodulin, mohawk homeobox, bone morphogenetic protein receptor, type 1A, bone morphogenetic protein receptor, type 2, and Noggin in the osteoblast, interface, and fibroblast regions of a co-culture model of the murine preosteoblast cell line MC3T3-E1 and the fibroblast cell line 3T6. RESULTS: Stimulation with BMP-2 resulted in a significant upregulation of alkaline phosphatase (p < 0.001), osteocalcin (p < 0.001), collagens (p < 0.001), runt-related transcription factor 2 (p < 0.05), and osteopontin (p < 0.001) expression in the osteoblast region. In the interface region, BMP-2 exposure led to dose- and time-dependent upregulation of alkaline phosphatase (p < 0.001), osteocalcin (p < 0.001), osteopontin (p < 0.001), runt-related transcription factor 2 (p < 0.001), and markers of extracellular matrix production (p < 0.001). Both BMP receptors showed a significant BMP-2-dependent upregulation at the interface region, and Noggin was downregulated at the osteoblast and interface region following BMP-2 exposure. CONCLUSIONS: Exposure to BMP-2 upregulated the expression of genes associated with bone-tendon integration in vitro, suggesting the stimulation of transdifferentiation processes at the interface and fibroblast regions as well as the induction of positive feedback mechanisms. Further studies will be needed to establish BMP-2 dose and treatment algorithms following tendon reinsertion and reconstruction.

The osseous morphology of nondegenerated shoulders shows no side-related differences in elderly patients: an analysis of 102 computed tomography scans.

BACKGROUND: A precise understanding of glenohumeral anatomy is required to optimize preoperative planning in shoulder joint arthroplasty, which is difficult in the presence of degenerative disease. In unilateral disease, the contralateral shoulder can be used as a representation of normal anatomy; however, intrasubject differences in shoulder morphology have not been investigated. METHODS: A retrospective study of all patients aged >65 years who received whole body computed tomography at our trauma center from 2010 through 2014 was conducted. Right and left shoulder computed tomography scans were examined, and the following anatomic parameters were measured: humeral head diameter in anteroposterior and axial views, glenoid diameter in anteroposterior and axial views, glenoid surface, scapula neck depth, neck-shaft angle, glenoid inclination, glenoid/head ratio, and glenoid version. Patients with inadequate scan quality, osseous lesions, pre-existing anatomic abnormality, or metallic implant at the shoulder region and significant osteoarthritis were excluded. RESULTS: The study analyzed 102 shoulders of 51 patients. Mean age was 71.4 ± 8.2 years. Humeral head and glenoid diameters, scapula neck depth (right, 36 ± 8 mm; left, 36 ± 7 mm; P = .684), glenoid/head ratio (right, 0.6 ± 0.1; left, 0.6 ± 0.0; P = .961), and glenoid surface (right, 790 ± 152 mm(2); left, 754 ± 134 mm(2); P = .215) showed no significant side-related differences. In addition, no significant difference was found regarding the neck-shaft angle (P = .211) and glenoid anteversion or retroversion (right, 65% [n = 33] anteversion and 35% [n = 18] retroversion; left, 69% [n = 35] anteversion and 31% [n = 16] retroversion; P = .417). CONCLUSION: There are no significant side-dependent differences in the osseous anatomy of the glenohumeral joint. In patients with unilateral shoulder degeneration, the contralateral shoulder can provide reference values during the planning of shoulder replacement surgery.

Age-dependent variation of glenohumeral anatomy: a radiological study.

PURPOSE: Profound knowledge of variations in shoulder anatomy is gaining relevance in daily clinical work. In our study, we examine age-dependent variations of glenohumeral parameters in healthy individuals. METHODS: In this analysis, 774 severely injured patients who received a whole-body computed tomography (CT) scan were included. Patients with shoulder fractures were excluded. The resulting scans were split into two groups: patients younger than 25 (group 1) and older than 60 years (group 2). These groups were divided into four subgroups according to gender. Shoulder scans with advanced osteoarthritis were then removed. In order to maintain equal group size, redundant patients were randomly removed. RESULTS: A total of 210 measurements from 106 patients were included. The humeral head diameter (group 1: 41.6 ± 3.7 mm, group 2: 44.5 ± 3.7 mm, p < 0.001) and glenoid surface (group 1: 627.0 ± 110.8 mm(2), group 2: 763.9 ± 148.5 mm(2), p < 0.001) showed higher values in the group of older patients. Older patients also had a higher glenoid inclination (group 1: 50.9 ± 6.9°, group 2: 55.7 ± 8.8°, p < 0.001) as well as an increased glenoid to head ratio (group 1: 0.61 ± 0.04, group 2: 0.64 ± 0.05, p < 0.001). CONCLUSIONS: Increased sizes of humeral head and glenoid surface are present in older patients without signs of osteoarthritis. Moreover, in patients with increased age more glenoid inclination as well as an increased glenoid to head ratio was revealed. These age-dependent anatomical parameters should be considered during planning of operative procedures of the shoulder joint.

The Effect of Cyclooxygenase Inhibition on Tendon-Bone Healing in an In Vitro Coculture Model.

The effects of cyclooxygenase (COX) inhibition following the reconstruction of the anterior cruciate ligament remain unclear. We examined the effects of selective COX-2 and nonselective COX inhibition on bone-tendon integration in an in vitro model. We measured the dose-dependent effects of ibuprofen and parecoxib on the viability of lipopolysaccharide- (LPS-) stimulated and unstimulated mouse MC3T3-E1 and 3T3 cells, the influence on gene expression at the osteoblast, interface, and fibroblast regions measured by quantitative PCR, and cellular outgrowth assessed on histological sections. Ibuprofen led to a dose-dependent suppression of MC3T3 cell viability, while parecoxib reduced the viability of 3T3 cultures. Exposure to ibuprofen significantly suppressed expression of Alpl (P < 0.01), Bglap (P < 0.001), and Runx2 (P < 0.01), and although parecoxib reduced expression of Alpl (P < 0.001), Fmod (P < 0.001), and Runx2 (P < 0.01), the expression of Bglap was increased (P < 0.01). Microscopic analysis showed a reduction in cellular outgrowth in LPS-stimulated cultures following exposure to ibuprofen and parecoxib. Nonselective COX inhibition and the specific inhibition of COX-2 led to region-specific reductions in markers of calcification and cell viability. We suggest further in vitro and in vivo studies examining the biologic and biomechanical effects of selective and nonselective COX inhibition.

Bone morphogenetic protein-7 enhances bone-tendon integration in a murine in vitro co-culture model.

PURPOSE: Bone-tendon healing following anterior cruciate ligament reconstruction is reportedly enhanced by bone morphogenetic protein (BMP)-7. To improve our understanding of the underlying biologic processes, we examined the effects of BMP-7 on region-specific gene expression in vitro. METHODS: A murine in vitro co-culture model simulating the osteoblast, interface and fibroblast regions was established. The dose- and time-dependent region-specific effects of BMP-7 exposure on gene expression of Alpl, Bglap, Col1a1, Runx2 and Spp1 were analysed by quantitative PCR. RESULTS: At the osteoblast region, BMP-7 significantly increased Alp, Bglap, Col1a1, and Runx2 expression, while Spp1 expression was suppressed. At the interface region, BMP-7 exposure resulted in a trend towards increased expression rates of Alpl and Col1a1, whereas Bglap (P < 0.001) and Runx2 (P < 0.01) were significantly upregulated without any detectable effect on Spp1 expression. At the fibroblast region, BMP-7 increased Alpl (P < 0.001), Bglap (P < 0.001) and Runx2 (P < 0.001) expression, but no significant effects were seen on Col1a1 or Spp1. Exposure to BMP-7 (100 ng/ml) had its most pronounced biologic impact on day ten. CONCLUSION: BMP-7 stimulation showed beneficial region-specific effects on bone-tendon healing in vitro, such as enhanced expression of parameters for ossification and fibroblast transdifferentiation, both key processes during successful graft integration.

The influence of pre-existing radiographic osteoarthritis on functional outcome after trochanteric fracture.

PURPOSE: It is crucially important to optimise functional outcome after fixation of trochanteric femoral fractures. While a number of risk factors that predict a poor clinical course have been identified, the influence of pre-existing radiographic osteoarthritis (OA) of the hip is unclear. METHODS: The influence of pre-existing radiographic OA of the hip on short- to mid-term functional outcome was prospectively analysed in a cohort of patients undergoing proximal femoral nailing for trochanteric fracture. OA was graded according to Kellgren and Lawrence; functional outcome was assessed at six and 12 months by the Harris hip score (HHS), the timed up and go (TUG) test and the Barthel Index. RESULTS: Our cohort comprised 188 patients (58 were male and 130 female), with a mean age of 82 years. At six and 12 months postoperatively, the HHS (p < 0.001 and p = 0.008, respectively) and Barthel Index (p < 0.001 and p = 0.02, respectively) correlated significantly with the grade of pre-existing OA. After adjustment for confounding variables, there was a significant association between the grade of pre-existing OA and the HHS at six months (p = 0.02). Although we observed trends suggestive of other relationships, none reached statistical significance. CONCLUSIONS: Pre-existing radiographic OA of the hip is an important determinant of clinical outcome in elderly patients with a trochanteric femoral fracture. Further studies will be needed to establish the most effective means of restoring hip function after trochanteric femoral fracture in patients with radiographic OA of the hip.

Second-look arthroscopic findings and clinical results after polyethylene terephthalate augmented anterior cruciate ligament reconstruction.

PURPOSE: Based on the revival of artificial ligaments containing polyethylene terephthalate, this study aimed to evaluate objective intra-articular findings within scheduled second-look arthroscopy, patient-reported clinical outcome and stability after isolated augmented ACL reconstruction with polyethylene terephthalate (Trevira®) augmented patella-bone-tendon-bone graft. METHODS: In a retrospective analysis of our institutional database, we found 126 patients with polyethylene terephthalate (Trevira®) augmented ACL reconstruction. All these patients underwent standardised second-look arthroscopic evaluation when removal of the augmentation became necessary. These second-look arthroscopic analyses focused on graft integration and remodelling in line with the polyethylene terephthalate augmentation. Arthroscopic re-examination comprised a graft evaluation including a structural and functional classification according to the Marburger Arthroscopy Score (MAS). Additional clinical evaluation was performed via the IKDC score and the scores of Tegner and Lysholm. Instrumental anterior laxity testing was carried out with a KT-1000™ arthrometer. Furthermore, a correlation analysis between the clinical parameters, the instrumental stability assessment and the corresponding arthroscopic graft condition was performed. RESULTS: The arthroscopic evaluation showed rupture of 87 (69 %) of 126 augmentation devices. In 27 (31 %) of these 87 cases, synovial reactions were found particularly in the anterior compartment. An intact synthetic augmentation with signs of graft integration with intact synovial coating was only found in 30 %. Evaluation according to the MAS showed good to excellent structural and functional characteristics in 88 % of patients. Presence of a type III graft (MAS) was found in an additional 11 %. A rudimentary (type IV) graft was only detected once. Eighty-five percent of patients were graded A or B according to IKDC score. The Lysholm score was 92.4 ± 4.8. Correlation analysis demonstrated a significant relationship between clinical outcome according to the IKDC score (p<0.05), instrumental stability performance according to the KT-1000™ assessment (p<0.05) and the corresponding arthroscopic graft evaluation according to the MAS. CONCLUSION: Graft integration and remodelling has complex and multi-factorial origins, particularly with artificial augmentation. Correlation analysis showed a significant relation between clinical condition, instrumental stability performance and arthroscopic graft constitution. The release of polyethylene terephthalate fibres caused inflammation of synovial tissue of the knee. Characteristic sub-clinical graft changes of structural, morphological and functional qualities of the inserted graft appear on second-look arthroscopy despite good clinical results.

Surgical complications following ESIN for clavicular mid-shaft fractures do not limit functional or patient-perceived outcome.

Elastic intramedullary nailing (ESIN) has been proposed as an alternative minimal-invasive method for the operative management of mid-shaft fractures of the clavicle. However, a relevant complication rate has been reported in previous cohorts. The present retrospective single-centre study aimed to analyse the complications following ESIN in adult patients with clavicular mid-shaft fractures (Allman type I) and their impact on functional and patient-perceived outcome measures. Results were compared to a control group receiving locking plate osteosynthesis. The clinical course and outcome of operatively managed patients with clavicular mid-shaft fractures were retrospectively analysed. Patients were assigned to group A (ESIN) and group B (plate fixation). Radiological, functional (Constant Murley Shoulder Outcome Score (CS), the Disabilities of the Arm, Shoulder and Hand (DASH) Score, the Oxford Shoulder Score (OSS)), and patient perceived aesthetic and clinical outcome were measured. A total of 47 (33 male, 14 female) operatively managed patients with a mean age of 26.7 ± 14.9 years and a follow up time of 38.1 ± 19.4 months were analysed. 36 patients were treated by ESIN (Group A), whereas 11 patients received open reduction and internal plate fixation (Group B). Patients were operatively treated with a mean delay of 7.4 ± 9.3 days (group A: 6.6 ± 8.7 days, group B: 10.2 ± 11.1 days, p=0.326) between trauma and the surgical index procedure. There were no significant differences in the functional (CS: p=0.338, DASH: p=0.247, OSS: p=0.434) and patient-perceived (p=0.346) outcome measures between both groups. Surgical complications were noted in 14 patients (group A: 12, group B: 2) and non-union in 4 patients (group A: 3, group B: 1). There was no correlation between the recorded complications as assessed by the Clavien and Dindo classification and the functional as well as the patient-perceived outcome measures. Despite a relevant incidence rate of surgical complications, ESIN provides good to excellent functional and patient-perceived results in the treatment of clavicular mid-shaft fractures.

Is there a benefit of proximal locking screws in osteoporotic distal radius fractures? - A biomechanical study.

INTRODUCTION: The distal radial fracture is a common fracture and frequently seen in geriatric patients. During the last years, volar plating has become a popular treatment option. While the application of locking screws at the distal fragment is widely accepted, there is no evidence for their use at the radial shaft. MATERIALS AND METHODS: In six osteoporotic pairs of matched human cadaver radii an extra-articular model creating an AO 23-A2.1 fracture was employed. Osteosynthesis were performed using the APTUS 2.5 Adaptive TriLock Distal Radius System (Medartis AG) with locking (LS) or non-locking screws (NLS) for proximal fixation. Biomechanical testing was performed in a staircase fashion: starting with 50 cycles at 200N, the load was continuously increased by 50N every 80 cycles up to a maximum force of 400N. Finally, load to failure was analyzed with failure defined as sudden loss of force measured (20%) or major deformation of the radii (10mm). RESULTS: At 200N, 250N, 300N, 400N and load to failure, the NLS group showed a higher degree of elastic modulus. In contrast, the LS group showed higher elastic modulus at 350N. Maximum force was higher in the LS group without reaching statistical significance. Reasons for loss of fixation were longitudinal shaft fractures, horizontal peri-implant fractures and distal cutting out. No difference was seen between the two groups concerning the development of the above mentioned complications. CONCLUSION: Our study did not show biomechanical superiority for distal radius fracture fixation by using locking screws in the proximal holes in an osteoporotic cadaver study. At load to failure, longitudinal shaft fractures and peri-implant fractures seemed to be a more relevant problem rather than failure of the proximal fixation.

Association of an In-House Blood Bank with Therapy and Outcome in Severely Injured Patients: An Analysis of 18,573 Patients from the TraumaRegister DGU®.

INTRODUCTION: Hemorrhagic shock remains one of the most common causes of death in severely injured patients. It is unknown to what extent the presence of a blood bank in a trauma center influences therapy and outcome in such patients. MATERIAL AND METHODS: We retrospectively analyzed prospectively recorded data from the TraumaRegister DGU® and the TraumaNetzwerk DGU®. Inclusion criteria were Injury Severity Score (ISS) ≥ 16, primarily treated patients, and hospital admission 2 years before or after the audit process. RESULTS: Complete data sets of 18,573 patients were analyzed. Of 457 hospitals included, 33.3% had an in-house blood bank. In trauma centers with a blood bank (HospBB), packed red blood cells (PRBCs) (21.0% vs. 17.4%, p < 0.001) and fresh frozen plasma (FFP) (13.9% vs. 10.2%, p <0.001) were transfused significantly more often than in hospitals without a blood bank (Hosp0). However, no significant difference was found for in-hospital mortality (standard mortality ratio [SMR, 0.907 vs. 0.945; p = 0.25). In patients with clinically apparent shock on admission, no difference of performed transfusions were present between HospBB and Hosp0 (PRBCs, 51.4% vs. 50.4%, p = 0.67; FFP, 32.7% vs. 32.7%, p = 0.99), and no difference in in-hospital mortality was observed (SMR, 0.907 vs. 1.004; p = 0.21). DISCUSSION: In HospBB transfusions were performed more frequently in severely injured patients without positively affecting the 24h mortality or in-house mortality. Easy access may explain a more liberal transfusion concept.

Bone morphogenetic protein 7 (BMP-7) influences tendon-bone integration in vitro.

INTRODUCTION: Successful graft ingrowth following reconstruction of the anterior cruciate ligament is governed by complex biological processes at the tendon-bone interface. The aim of this study was to investigate in an in vitro study the effects of bone morphogenetic protein 7 (BMP-7) on tendon-bone integration. MATERIALS AND METHODS: To study the biological effects of BMP-7 on the process of tendon-bone-integration, two independent in vitro models were used. The first model involved the mono- and coculture of bovine tendon specimens and primary bovine osteoblasts with and without BMP-7 exposure. The second model comprised the mono- and coculture of primary bovine osteoblasts and fibroblasts. Alkaline phosphatase (ALP), lactate dehydrogenase (LDH), lactate and osteocalcin (OCN) were analyzed by ELISA. Histological analysis and electron microscopy of the tendon specimens were performed. RESULTS: In both models, positive effects of BMP-7 on ALP enzyme activity were observed (p<0.001). Additionally, similar results were noted for LDH activity and lactate concentration. BMP-7 stimulation led to a significant increase in OCN expression. Whereas the effects of BMP-7 on tendon monoculture peaked during an early phase of the experiment (p<0.001), the cocultures showed a maximal increase during the later stages (p<0.001). The histological analysis showed a stimulating effect of BMP-7 on extracellular matrix formation. Organized ossification zones and calcium carbonate-like structures were only observed in the BMP-stimulated cell cultures. DISCUSSION: This study showed the positive effects of BMP-7 on the biological process of tendon-bone integration in vitro. Histological signs of improved mineralization were paralleled by increased rates of osteoblast-specific protein levels in primary bovine osteoblasts and fibroblasts. CONCLUSION: Our findings indicated a role for BMP-7 as an adjuvant therapeutic agent in the treatment of ligamentous injuries, and they emphasized the importance of the transdifferentiation process of tendinous fibroblasts at the tendon-bone interface.

Effect of bone morphogenetic protein-2 on tendon-bone integration in an in vitro cell culture.

The goal of this study was to evaluate the influence of bone morphogenetic protein-2 (BMP-2) on tendon-bone integration in a bovine in vitro cell culture. Seventy-two bovine tendons were cultivated over 3 months. The effects of BMP-2 were evaluated by generation in 4 subgroups. The groups differed in 2 parameters: the application of BMP-2 and the application of primary bovine osteoblasts. Results were analyzed biochemically by determining alkaline phosphatase activity and histologic tendon calcification, both markers for graft incorporation. Histological analysis demonstrated a positive effect of BMP-2 on the production of extracellular matrix and therefore the induction of osteogenesis. In addition, the results showed a superior cell ingrowth on the tendon in the BMP-2-stimulated groups. Calcium carbonate-like structures and organized ossification zones could only be detected in the BMP-2-stimulated tendons. The histological results matched those of the biochemical alkaline phosphatase analysis. The highest alkaline phosphatase activity was detected using BMP-2 stimulation in the first month (P<.001). High alkaline phosphatase values suggest high osteoblast activity and a high potential for mineralization. Furthermore, a positive effect of BMP-2 on fibroblasts existed with regard to the overall integration process. These results confirm the positive influence and triggering effect of BMP-2 on the mineralization process. Bone morphogenetic protein-2 seems to accelerate and optimize tendon-bone integration in the early process of graft incorporation. Besides the influence of BMP-2 on bovine osteoblasts, an additional positive effect of BMP-2 on bovine fibroblasts was detected; therefore, graft incorporation may be carried out by osteoblasts and fibroblasts.

Biomechanical evaluation of 2 insertion points for ventral screw fixation of C-2 dens fractures.

OBJECT: For many type II fractures of the dens (Anderson and D'Alonzo classification), a double anterior screw fixation is performed. If screw disruption occurs, the location is most often at the anterior caudal endplate and body of the axis and not directly at the fracture line. The authors' objective was to determine the differences in primary mechanical stability at 2 insertion points used in ventral screw fixation of type II fractures of the C-2 dens. METHODS: Screw fixation was performed on 16 formalin-fixed human C-2 dens specimens. The specimens were divided into 2 groups. For group 1, the screws were inserted directly at the anterior lower endplates; for group 2, the screws were inserted 2 mm dorsal to the anterior wall of the vertebral body. After a type II odontoid fracture was created with an oscillating saw, screw fixation was performed using two 3.5-mm partially threaded lag screws with washers. Subsequently, each vertebral body was continuously loaded. The criterion for breakage was reversal of the force vector. RESULTS: In group 1, screw disruption occurred at the point of entry; the mean load failure was 290.5 ± 106 N. In group 2, no screw disruption occurred; the mean load failure was 574.2 ± 170.5 N. These results were significant (p < 0.05). CONCLUSIONS: For double screw fixation of type II fractures of the dens (Anderson and D'Alonzo classification), placement of the screws as far dorsal to the anterior lower endplate as possible seems to favorably affect primary stability. In actual clinical practice, care should be taken to not damage the anterior wall of the vertebral body of the axis during screw insertion.

Prevalence and influence of tibial tunnel widening after isolated anterior cruciate ligament reconstruction using patella-bone-tendon-bone-graft: long-term follow-up.

The aim of the present study was to evaluate incidence, degree and impact of tibial tunnel widening (TW) on patient-reported long-term clinical outcome, knee joint stability and prevalence of osteoarthritis (OA) after isolated anterior cruciate ligament (ACL) reconstruction. On average, 13.5 years after ACL reconstruction via patella-bone-tendon-bone autograft, 73 patients have been re-evaluated. Inclusion criteria consisted of an isolated anterior cruciate ligament rupture and reconstruction, a minimum of 10-year follow-up and no previous anterior cruciate ligament repair or associated intra-articular lesions. Clinical evaluation was performed via the International Knee Documentation Committee (IKDC) score and the Tegner and Lysholm scores. Instrumental anterior laxity testing was carried out with the KT-1000™ arthrometer. The degree of degenerative changes and the prevalence of osteoarthritis were assessed with the Kellgren-Lawrence score. Tibial tunnel enlargement was radiographically evaluated on both antero-posterior and lateral views under establishment of 4 degrees of tibial tunnel widening by measuring the actual tunnel diameters in mm on the sclerotic margins of the inserted tunnels on 3 different points (T1-T3). Afterwards, a conversion of the absolute values in mm into a 4 staged ratio, based on the comparison to the results of the initial drill-width, should provide a better quantification and statistical analysis. Evaluation was performed postoperatively as well as on 2 year follow-up and 13 years after ACL reconstruction. Minimum follow-up was 10 years. 75% of patients were graded A or B according to IKDC score. The mean Lysholm score was 90.2±4.8 (25-100). Radiological assessment on long-term follow-up showed in 45% a grade I, in 24% a grade II, in 17% a grade III and in additional 12% a grade IV enlargement of the tibial tunnel. No evident progression of TW was found in comparison to the 2 year results. Radiological evaluation revealed degenerative changes in sense of a grade II OA in 54% of patients. Prevalence of a grade III or grade IV OA was found in 20%. Correlation analysis showed no significant relationship between the amount of tibial tunnel enlargement (P>0.05), long-term clinical results, anterior joint laxity or prevalence of osteoarthritis. Tunnel widening remains a radiological phenomenon which is most commonly observed within the short to midterm intervals after anterior cruciate ligament reconstruction and subsequently stabilises on mid and long- term follow-up. It does not adversely affect long-term clinical outcome and stability. Furthermore, tunnel widening doesn't constitute an increasing prevalence of osteoarthritis.