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.

Improvement in outcomes after implantation of a novel polyurethane meniscal scaffold for the treatment of medial meniscus deficiency.

PURPOSE: Meniscal injury resulting in segmental loss of meniscal tissue is a major risk factor for the development of osteoarthritis. Tissue engineering strategies have provided scaffolds for meniscal regeneration in order to establish a treatment option for patients with limited opportunities for meniscal reconstruction. The purpose of this study was to assess the clinical and magnetic resonance imaging (MRI) results 2 years after implantation of a polyurethane scaffold for chronic segmental medial meniscus deficiency following partial medial meniscectomy. METHODS: Eighteen patients were treated with arthroscopic implantation of an ActiFit(®) (Orteq Sports Medicine) polyurethane meniscal scaffold for meniscus deficiency of the medial meniscus. Patients were followed up at 6, 12, and 24 months. Clinical outcome was assessed using patient-reported outcome scores (KOOS, KSS, UCLA activity scale, VAS for pain). Radiological outcome was assessed using MRI at 6, 12, and 24 months by evaluating scaffold morphology, scaffold integration, and additional joint injury, as well as joint inflammation. RESULTS: Eighteen patients with a median age of 32.5 years (range 17-49) were enrolled. Statistically significant improvements were present in all patients, but one at 2 years compared to baseline in all categories. Complete resorption of the scaffold occurred in one patient representing a failure to treatment. MRI showed abnormal signal intensity of the scaffold when compared to residual meniscal tissue but without synovitis or joint inflammation. Extrusion of the scaffold was present in four patients. No correlation between scaffold extrusion and clinical outcome was observed. CONCLUSION: Arthroscopic implantation of a polyurethane meniscal scaffold in patients with chronic segmental medial meniscus deficiency is not only a safe procedure but leads to good clinical results at a 2-year follow-up. Scaffold extrusion did not appear to affect clinical outcome. LEVEL OF EVIDENCE: IV.

Patellofemoral osteoarthritis after Insall's proximal realignment for recurrent patellar dislocation.

PURPOSE: The aim of the present study was to retrospectively investigate the development of patellofemoral osteoarthritis after the historical Insall's proximal realignment for patellar stabilisation in patients with recurrent patellar dislocation. Furthermore, risk factors for recurrent patellar dislocation and for patellofemoral osteoarthritis development were evaluated. METHODS: Forty-two patients underwent patellofemoral stabilising surgery by the historic Insall's proximal realignment; they were evaluated with a mean follow-up period of 52 months. Plain radiography was used to document osteoarthritic changes by using the Iwano classification. MRIs obtained at the latest follow-up were evaluated for patellofemoral cartilage lesions. Univariate and multivariate logistic regression analyses were performed to evaluate the influence of trochlear dysplasia, tibial tubercle-trochlear groove distance and patellar height on redislocation. Pearson's χ (2) and the Spearman's correlation tests were used to assess a possible correlation between trochlear dysplasia and patellar dislocation, as well as between instability and development of patellofemoral osteoarthritis. RESULTS: At the latest follow-up, plain radiographs showed a significant increase in patellofemoral osteoarthritis (grades II-IV according to the Iwano classification) in 18 patients (43%) compared with 4 patients (10%) at the time of surgery (P = 0.001). Patellofemoral cartilage lesions (grades II-IV) were detected in 18 patients (43 %) on MRI. Nine patients (21%) had at least one incidence of redislocation at follow-up. Estimated redislocation-associated risk factors could not be determined. Trochlear dysplasia had a significant impact on patellofemoral osteoarthritis development (P = 0.001), whereas recurrent patellar instability had none (n.s.). CONCLUSION: Insall's proximal realignment technique leads to a significant progression of patellofemoral osteoarthritis. No risk factors for redislocation could be found; however, the presence of trochlear dysplasia did correlate with patellofemoral osteoarthritis. LEVEL OF EVIDENCE: IV.

Massive hematothorax after thoracic spinal manipulation for acute thoracolumbar pain.

Spinal manipulation usually represents a widely used and effective method for physicians in order to relieve acute patient pain and muscular dysbalance. Although life-threatening complications (e.g. pneumothorax, vertebral artery dissection, stroke) after manual treatment are reported with regard to actual medical literature millions of patients undergo manual treatment to manage thoracolumbar pain each year. The authors present the case of a 17 year old male patient with a life-threatening hematothorax after thoracic high velocity spinal manipulation for acute thoracolumbar pain. The patient required emergency chest tube thoracostomy and afterwards thoracoscopic haemostasis for an intercostal venous lesion. A massive hematothorax after spinal manipulation represents an extremely rare but life-threatening complication. Physicians are encouraged to promote the benefits of manual/chiropratic therapy on the one hand but on the other hand are obliged to educate about potential serious dangers and adverse events.

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.

Isolated anterior cruciate ligament reconstruction in patients aged fifty years: comparison of hamstring graft versus bone-patellar tendon-bone graft.

PURPOSE: Anterior cruciate ligament (ACL) deficiency contributes to symptomatic functional instability of the knee, regardless of age. We evaluated patient-reported clinical outcome, instrumental stability and prevalence of radiological osteoarthritis based on two homogenous patient samples aged 50 years, an average of three years after isolated ACL reconstruction. METHODS: ACL reconstruction using a bone-patellar tendon-bone (BPTB) autograft was done in 19 patients and a four-stranded semitendinosus tendon (ST) autograft in 22 patients. Clinical and functional follow-up assessment was performed an average of 32 months after surgical treatment. Clinical and functional follow-up assessment included the International Knee Documentation Committee (IKDC) score, Tegner score and Lysholm score. Instrumental stability testing was carried out using the KT-1000™ arthrometer. The degree of degenerative changes and prevalence of osteoarthritis was based on the Kellgren-Lawrence classification. RESULTS: Mean follow-up was 32 months (range, 28-36). Mean age was 49.4 years in both groups. The median pre-injury Tegner score was 5.5 (range, 2-8) and the median preoperative Lysholm score was 35 (range, 15-69). At two years, all variables improved significantly for both groups compared to the preoperative values (P < 0.05), with no significant intergroup differences. Approximately 76 % of patients were graded A or B according to the IKDC score in both groups. Activity level according to the scores of Tegner and Lysholm was 4.9/5.3 and 83.4/82.5 on two-year-follow up in both groups. Radiological assessment reported degenerative changes of grade I Osteoarthritis (OA) in 36 % of patients. Grade-II OA was found in 31 % of patients. Grade-III OA and grade-IV OA were found in about 24 % and 7 % of all patients, respectively. Correlation analyses showed significant relationships between conservation of knee-joint stability and clinical outcome according to the IKDC score, and activity level according to the Lysholm score (p < 0.05). CONCLUSION: Arthroscopic ACL reconstruction using either BPTB graft or hamstring graft in appropriately selected middle-aged patients results in patient satisfaction and good clinical results, with return to a reasonable level of activity regardless of surgical method and graft choice.

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.

Clinical outcome and prevalence of osteoarthritis after isolated anterior cruciate ligament reconstruction using hamstring graft: follow-up after two and ten years.

PURPOSE: The aim of this study was to evaluate patient-reported clinical outcome, instrumental stability and prevalence of radiological osteoarthritis (OA) based on a homogeneous patient sample after two years and on average ten years after isolated anterior cruciate ligament (ACL) reconstruction. METHODS: Primarily we performed ACL reconstruction using a four-strand semitendinosus tendon (ST) autograft in 112 patients. Two years after reconstruction 98 patients could be re-evaluated. Long-term clinical and functional follow-up assessment was then performed on 52 patients on average 10.2 years after operative treatment. Inclusion criteria consisted of an isolated ACL rupture, reconstruction with ST graft and no associated cartilage alterations and meniscal lesions. Clinical and functional follow-up assessment included the International Knee Documentation Committee (IKDC) score and the scores of Tegner and Lysholm. Instrumental stability testing was carried out with the KT1000™ arthrometer. The degree of degenerative changes and prevalence of OA was based on the Jäger-Wirth score. RESULTS: The mean long-term follow-up was 10.2 years (eight-13 years), and the mean age was 40.4 years (24-62 years). About 72 % of patients were graded A or B according to the IKDC score. Activity levels according to the scores of Tegner and Lysholm were 4.8 and 88.2 on long-term follow-up. Radiological assessment revealed degenerative changes in the sense of a grade I OA in 21.2 % of patients. Prevalence of a grade II OA was found in 53.8 % of patients. A grade III OA and a grade IV OA were found in 19.2 and 5.7 %. Correlation analysis showed significant relationships between the long-term stability and prevalence of OA (p<0.05). CONCLUSIONS: Arthroscopic ACL reconstruction using four-strand ST autograft resulted in high patient satisfaction and good clinical results at two years and long-term follow-up. The prevalence of higher degree OA that developed in about 25 % of patients is significantly correlated with long-term knee joint stability.

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.

Percutaneous minimally invasive instrumentation for traumatic thoracic and lumbar fractures: a prospective analysis.

Open posterior instrumentation is still the standard procedure for unstable traumatic thoracic and lumbar fractures. There is a general tendency towards minimally invasive approaches in various surgical disciplines. The Sextant II Rod Insertion system is one of these. The authors prospectively studied this system in 51 patients with thoracic and lumbar fractures, between October 2007 and January 2011. Most fractures (31/51) were situated at the lumbar level. In 7 older patients the technique was combined with kyphoplasty and/or cement augmentation of the pedicle screws. The median operative time was 61 minutes (range: 26-130). The median fluoroscopy time was 132 seconds (range: 24-414). Most pedicle screws were correctly placed: 197 out of 204 screws. All fractures showed bony union after 6 weeks, but the multiaxial pedicle screws were not able to conserve the slight correction obtained peroperatively via positioning and longitudinal traction. Percutaneous minimally invasive stabilization of the spine needs further improvement.

Knee function and prevalence of osteoarthritis after isolated anterior cruciate ligament reconstruction using bone-patellar tendon-bone graft: long-term follow-up.

PURPOSE: The aim of this investigation was to study patient-reported long-term clinical outcome, instrumental stablitity and prevalence of radiological osteoarthritis (OA) a minimum of ten years after isolated anterior cruciate ligament (ACL) reconstruction. METHODS: An average of 13.5 years after ACL reconstruction with bone-patellar tendon-bone (BTB) autograft, 73 patients were evaluated. Inclusion criteria consisted of an isolated ACL rupture and reconstruction with BPTB graft with no associated intra-articular lesions, in particular, cartilage alterations or meniscal lesions. Clinical assessment was performed using the International Knee Documentation Committee (IKDC) and Tegner and Lysholm scores. Instrumental anterior laxity testing was carried out with the KT-1000™ arthrometer. Degree of degenerative changes and prevalence of OA were determined using the Kellgren- Lawrence scale. RESULTS: Mean follow-up was 13.5 years. Mean age was 43.8 years. About 75% of patients were graded A or B according to the IKDC score. The Lysholm score was 90.2 ± 4.8. Radiological assessment reported degenerative changes of grade II OA in 54.2% of patients. Prevalence of grades III or IV OA was found in 20%. The incidence of OA was significantly correlated with stability and function at long-term follow-up. CONCLUSION: Arthroscopic ACL reconstruction using BPTB autograft resulted in a high degree of patient satisfaction and good clinical results on long-term follow-up. A higher degree of OA developed in 20% of patients and was significantly correlated with increased anterior laxity at long-term follow-up.

Dislocation of the mandibular condyle into the middle cranial fossa causing an epidural haematoma.

Dislocation of the mandibular condyle into the middle cranial fossa is a rare complication of mandibular trauma due to anatomical and biomechanical factors. Owing to the proximity of the temporal glenoid fossa to the middle meningeal artery, there is the risk of serious sequelae in case of trauma. The authors report the case of a 36-year-old male patient, who was beaten up in a family dispute and presented with complex mandibular and maxillofacial fractures, including mandibular condyle intrusion into the middle cranial fossa causing extensive meningeal bleeding. The patient underwent immediate surgery, with evacuation of the epidural haematoma via a temporal approach. In addition open reduction and reconstruction of the temporal glenoid fossa via anatomic reduction of the fragments was performed. A functional occlusion was re-established via miniplate reconstruction of the complex mandibular body and ramus fractures. Prompt diagnosis and a multidisciplinary approach are essential to minimize the complications. Advanced imaging modalities of computed tomography are indicated. Treatment options should be individualized in particular in case of suspected neurological injury.

Kyphoplasty for the treatment of incomplete osteoporotic burst fractures.

Kyphoplasty has become a standard procedure in the treatment of painful osteoporotic compression fractures. According to current guidelines, involvement of the posterior wall of the vertebral body is a relative contraindication. From February 2002 until January 2008, 97 patients with at least one AO classification A 3.1 fracture were treated by kyphoplasty. There was a structured follow-up for the medium-term evaluation of the patients' outcome. Ninety-seven patients (68 of whom were females and 29 of whom were males) with involvement of the vertebra's posterior margin averaging 76.1 +/- 12.36 (59-98) years were treated by kyphoplasty. The fractures of 75 patients were caused by falls from little height, 5 patients had suffered traffic accidents and in the case of 17 patients, no type of trauma was remembered. According to the AO classification, there were 109 A 3.1.1 and one A3.1.3 injuries. Prior to surgery, all patients were neurologically without pathological findings. Seventy-nine fractures were accompanied by a narrowing of the spinal canal [average of 15% (10-40)]. Overall, 134 vertebras were treated by Balloon kyphoplasty (81 x 1 segment, 22 x 2 segments, 3 x 3 segments). In 47.4% of the patients, cement leakage was observed after surgery. All patients with cement extravasation, however, were clinically unremarkable. Using the visual analog scale, patients stated that prior to surgery their pain averaged 8.1, whereas after surgery it significantly decreased and averaged 1.6 (p < 0.001). In geriatric patients with osteoporotic vertebral fractures with partial inclusion of the posterior wall of the vertebral body, kyphoplasty is an effective procedure with few complications.