[Intra-articular fractures of the distal humerus : aspects of fracture treatment in geriatric patients]. / Intraartikuläre Frakturen des distalen Humerus : Aspekte der operativen Behandlung bei geriatrischen Patienten.

BACKGROUND: In the context of osteoporotic fractures, injuries to the distal humerus are quite uncommon, meaning that each surgeon will have only limited experience. OBJECTIVE: This leads automatically to the question to what extent treatment recommendations can be transferred to the geriatric population. METHODS: Looking at the evidence-based literature, recommendations could be limited to three prospective studies. However, this only means that the remaining literature sources do not provide sufficient statistical power to be able to draw conclusions. RESULTS AND DISCUSSION: For the population of geriatric patients a thorough compilation of the contemporary literature is advisable. This review article on the currently available literature evaluates and individually discusses the relevant aspects of fracture treatment in order to develop recommendations for routine daily practice.

Variation in care and outcome for fragile hip fracture patients: a European multicentre study benchmarking fulfilment of established quality indicators.

PURPOSE: Despite the availability of clinical guidelines for hip fracture patients, adherence to these guidelines is challenging, potentially resulting in suboptimal patient care. The goal of this study was (1) to evaluate and benchmark the adherence to recently established quality indicators (QIs), and (2) to study clinical outcomes, in fragile hip fracture patients from different European countries. METHODS: This observational, cross-sectional multicenter study was performed in 10 hospitals from 9 European countries including data of 298 consecutive patients. RESULTS: A large variation both within and between hospitals were seen regarding adherence to the individual QIs. QIs with the lowest overall adherence rates were the administration of systemic steroids (5.4%) and tranexamic acid (20.1%). Indicators with the highest adherence rates (above 95%) were pre-operative (99.3%) and post-operative haemoglobin level assessment (100%). The overall median time to surgery was 22.6 h (range 15.7-42.5 h). The median LOS was 9.0 days (range 5.0-19.0 days). The most common complications were delirium (23.2%) and postsurgical constipation (25.2%). CONCLUSION: The present study shows large variation in the care for fragile patients with hip fractures indicating room for improvement. Therefore, hospitals should invest in benchmarking and knowledge-sharing. Large quality improvement initiatives with longitudinal follow up of both process and outcome indicators should be initiated.

A clinical, radiological and computational analysis of the thrust plate prosthesis in young patients.

BACKGROUND AND PURPOSE: A thrust plate prosthesis can be used as an alternative to a conventional stem prosthesis, preserving the diaphyseal bone stock. Recent findings however predict a higher rate of aseptic loosening than with intramedullary devices. The purpose of our investigation was to compare the clinical outcome and radiological findings with a finite element analysis of bone remodeling. The hypothesis was that aseptic loosening after thrust plate prosthesis of the hip is inherent to the design. METHODS: From 1997 to 2001, 58 thrust plates were implanted in 52 patients. Average age at the time of surgery was 40.9 years. Ninety four percent returned for follow up at an average of 26 months. A finite element model of the thrust plate within the femur was developed and stress shielding as well as bone remodeling were analyzed. RESULTS: A total of 4 patients required revision surgery (6.9%). Data from the finite element analysis revealed an inherent failure mechanism to the implant, facilitating stress shielding and loosening. INTERPRETATION: Lacking the ideal total hip prosthesis in young patients, the thrust plate can still be regarded as a feasible implant. However, surgeons and patients should be aware of possible mechanical problems regarding the design of the thrust plate. There is evidence that thrust plate prostheses are prone to early aseptic loosening. Clinical and radiological observations are in agreement with the results from the numerical simulations. Stress concentrations computed at the leash are interpreted as an explanation for leash pain. The authors regard computational methods as an aid to improve existing prosthesis design and future developments.

Adenoviral gene transfer in a rat fracture model.

For the enhancement of fracture healing, either purified proteins or vectors for expression of growth factors in situ may be used. Adenoviral vectors directly convert cells to express a transgene. However, the cell types which are preferentially infected and the time of expression during fracture healing are currently not known. The adenoviral type 5 vectors used in this study are replication incompetent viruses, one encoding beta-galactosidase (beta-GAL) and one green fluorescent protein. Femora of 35 Sprague-Dawley rats were fractured. Three days after stabilization with Kirschner wire, 10(12) pfu viral suspension were injected into the fracture zone. As a control, five animals received injections of adenovirus type 2. Animals were sacrificed after 3 days, 1, 2 and 4 weeks. Fractures healed radiographically within 2-3 weeks. All specimens were examined for beta-GAL and green fluorescent protein (GFP) expression. Fibroblast and osteoblasts within callus tissue displayed a high transgene expression (week 1). A decrease of expression was observed during the observation period. In this experimental study, we have demonstrated that all cells of the primary callus can be transfected using adenoviral vectors, which provide a tool to further investigate adenoviral transfer of growth factors such as bone morphogenetic protein-2 (BMP-2).

[Gene transfer into the patellar tendon of rabbits: a preliminary study of locoregional expression of growth factors]. / Gentransfer in die Patellarsehne von Kaninchen: Eine vorbereitende Studie zur lokoregionären Expression von Wachstumsfaktoren.

Growth factors have the potential to enhance native repair responses in ligamentous and meniscal lesions. However, methods for applying these cytokines to sites of injury for extended periods are lacking. We suggest that local transfer of genes which encode the relevant healing factors merits investigation as a potential solution to this problem. In the present study different viral vectors and liposomes were evaluated for their ability to deliver genes to cells of ligamentous and meniscal origin. The anterior (ACL) and posterior (PCL) cruciate ligaments and the medial collateral ligament (MCL), semitendinosus tendon, patellar tendon, and menisci were removed from New Zealand white rabbits Cells grown from these tissues were then investigated for their susceptibility to genetic alteration by these vectors. Based upon the ability of these vectors to convert cells in culture to a lacZ(+) phenotype, adenovirus was the most effective vector in short-term experiments. However, expression was transient. Although retrovirus gave lower initial transduction efficiencies, the percentage of transduced cells was increased by the use of the selectable marker gene neo(r). Cells infected with adeno-associated virus containing the neo(r)-gene were also selected in this way. Liposomes showed low efficiency of gene transfer and expression. In an in vivo marker study we injected adenovirus into the rabbit patellar tendon. Transduced cells were observed mainly in the subsynovial layer at a declining frequency over a 6-week period. The allogeneic transplantation of retrovirally-transduced fibroblasts into the patellar tendon resulted in a greater number of transduced cells. Although the number of lacZ(+) cells declined with time, positive cells were still present 6 weeks after transplantation. Furthermore, the transplanted cells, unlike cells transduced in situ with adenovirus, migrated from the injection site and integrated into the crimp of the tendon.

Possibilities of gene therapy in traumatic and degenerative lesions of the joints. Current experimental status and preliminary clinical applications.

Soft tissue injuries often represent the greatest clinical problem. Not only do many of the most frequently injured tissues, such as the cruciate ligaments and articular cartilage, have very limited capabilities for spontaneous repair, but they also respond poorly to surgical or non-surgical intervention. In this article we try to define the role of growth factors in these conditions and to outline concepts for future treatment based upon modulation of the native repair response. We suggest that gene transfer could improve the management of such injuries, particularly when used as vehicles for the targetted delivery of growth factors.

Does bone compaction around the helical blade of a proximal femoral nail anti-rotation (PFNA) decrease the risk of cut-out?: A subject-specific computational study.

OBJECTIVES: Because of the contradictory body of evidence related to the potential benefits of helical blades in trochanteric fracture fixation, we studied the effect of bone compaction resulting from the insertion of a proximal femoral nail anti-rotation (PFNA). METHODS: We developed a subject-specific computational model of a trochanteric fracture (31-A2 in the AO classification) with lack of medial support and varied the bone density to account for variability in bone properties among hip fracture patients. RESULTS: We show that for a bone density corresponding to 100% of the bone density of the cadaveric femur, there does not seem to be any advantage in using a PFNA with respect to the risk of blade cut-out. On the other hand, in a more osteoporotic femoral head characterised by a density corresponding to 75% of the initial bone density, local bone compaction around the helical blade provides additional bone purchase, thereby decreasing the risk of cut-out, as quantified by the volume of bone susceptible to yielding. CONCLUSIONS: Our findings indicate benefits of using a PFNA over an intramedullary nail with a conventional lag screw and suggest that any clinical trial reporting surgical outcomes regarding the use of helical blades should include a measure of the femoral head bone density as a covariable.

Role of posterior capsulotomy for the treatment of extension deficits of the knee.

Chronic flexion contracture of the knee is difficult to treat, especially in cases with long-standing extension deficits and with generalised arthrofibrosis. We present a technique combining arthroscopic or open anterior debridement with a posterior capsulotomy. This capsulotomy is performed via a posteromedial incision and a posteromedial arthrotomy. All scar tissue is resected, and the entire posterior capsule is detached from its femoral attachment. Of 24 patients treated with arthroscopic arthrolysis and posterior capsulotomy from 1989 to 1993, 21 were reviewed with a mean follow-up of 18 months (range 6-38 months). The mean extension deficit preoperatively was 17 degrees (range 10-30 degrees), and symptoms and persisted from 6 months to 7 years. Extension improved to a mean value of 2 degrees; no patient had more than 5 degrees of extension deficit at follow-up. The knee function improved significantly (Lysholm Score preoperative 62, postoperative 88, Tegner Scale preoperative 2.2, postoperative 4.0). No neurovascular complications were observed, and we conclude that posterior capsulotomy is a safe and efficient adjunct procedure to anterior arthrolysis and is indicated in cases with chronic flexion contracture.

Prospects for gene therapy in sports medicine.

For the orthopedic sports medicine physician soft tissue injuries often present the greatest clinical problems. Not only do many of the most frequently injured tissues, such as the cruciate ligaments and articular cartilage, have very limited capabilities for spontaneous repair, but they also respond poorly to surgical or nonsurgical intervention. In this article we try to define the role of growth factors in these conditions and to outline concepts for future treatment based upon modulation of the native repair response. We suggest that gene transfer could improve the management of such injuries, particularly when used as vehicles for the targeted delivery of growth factors. The concept of gene therapy in orthopedic sports medicine can be extended to include disorders that present as laxity or mechanical weakness of ligaments. We speculate that subtle genetic differences between individuals may account for those who appear to be injury prone. In these cases it is likely that genes encoding the structural macromolecules of the matrix are defective. Local gene supplementation in such cases could be useful in the future.

Gene transfer to the rabbit patellar tendon: potential for genetic enhancement of tendon and ligament healing.

Injuries to ligaments and tendons occur very commonly, but often heal very poorly. A number of growth factors show promise as biological agents with which to augment the reparative responses of these tissues, but they are extremely difficult to deliver clinically. We have suggested the use of gene transfer as a possible way to obviate this limitation. Here we have used the lacZ marker gene to evaluate methods for gene delivery to ligaments and tendons. Cell cultures were established from the following tissues of the New Zealand white rabbit: anterior and posterior cruciate ligaments, medial collateral ligament, patellar tendon and semitendionsus. In vitro experiments confirmed that these cells were very efficiently transduced by an E1- E3- adenoviral vector carrying the lacZ gene. Cells derived from ligaments and tendons also proved readily susceptible to retroviral transduction and, following transfer of the ned gene, selection in G418. To determine whether these cells could be genetically altered in situ, gene transfer to the patellar tendons of rabbits' knee joints was attempted using an adenovirus for in vivo delivery and a retrovirus for ex vivo delivery. Direct, percutaneous injection of the adenovirus resulted in high levels of lacZ expression, but this was limited to the area of tendon immediately adjacent to the injection site, and preferentially labeled cells in the epitenon sheath. An unexpected finding of these studies was the in vivo adenoviral transduction of bone cells in areas where the tendon insertion site had been accidentally injected. Allotransplantation of tendon fibroblasts into which the lacZ gene had been retrovirally introduced led to lacZ expression throughout the body of the tendon itself. The genetically altered cells appeared able to migrate from the site of injection and to integrate themselves into the crimp pattern of the tissue. Both in vivo and ex vivo methods led to gene expression for at least 6 weeks, which may be long enough for clinical purposes.

Pullout strength of tibial graft fixation in anterior cruciate ligament replacement with a patellar tendon graft: interference screw versus staple fixation in human knees.

The endoscopic single incision technique for anterior cruciate ligament (ACL) reconstruction with a femoral half-tunnel may lead to a graft/tunnel mismatch and subsequent protrusion of the block from the tibial tunnel. The typical tibial fixation with an interference screw is not possible in these cases. Fixation with staples in a bony groove inferior to the tunnel outlet can be used as an alternative technique. Current literature does not provide biomechanical data of either fixation technique in a human model. This study was performed to evaluate the primary biomechanical parameters of this technique compared with a standard interference screw fixation of the block. Fifty-five fresh-frozen relatively young (mean age 44 years) human cadaver knee joints were used. Grafts were harvested from the patellar tendon midportion with bone blocks of 25 mm length and 9 mm width. A 10-mm tibial tunnel was drilled from the anteromedial cortex to the center of the tibial insertion of the ACL. Three different sizes of interference screws (7 x 30, 9 x 20, 9 x 30 mm) were chosen as a standard control procedure (n = 40). For tibial bone-block fixation the graft was placed through the tunnel, and the screw was then inserted on the cancellous or the cortical surface, respectively. Fifteen knees were treated by staple fixation. A groove was created inferior to the tunnel outlet with a chisel. The bone block was fixed in this groove with two barbed stainless steel staples. Tensile testing in both groups was carried out under an axial load parallel to the tibial tunnel in a Zwick testing machine with a velocity of 1 mm/s. Dislocation of the graft and stiffness were calculated at 175 N load. Maximum load to failure using interference screws varied between 506 and 758 N. Load to failure using staples was 588 N. Dislocation of the graft ranged between 3.8 and 4.7 mm for interference screw fixation and was 4.7 mm for staples. Stiffness calculated at 175 N load was significantly higher in staple fixation. With either fixation technique, the recorded failure loads were sufficient to withstand the graft loads which are to be expected during the rehabilitation period. Staple fixation of the bone block outside of the tunnel resulted in a fixation strength comparable to interference screw fixation.

Gene transfer to the patellar tendon.

Growth factors have the potential to enhance native repair responses in ligamentous lesions. However, methods for applying these cytokines to sites of injury for extended periods are lacking. We suggest that local transfer of genes which encode the relevant healing factors merits investigation as a potential solution to this problem. In the present study, the retroviral vectors MFG lacZ and BAG lacZ neo(r) and adenovirus LacZ were evaluated for their ability to deliver genes to cells of ligamentous origin. The posterior and anterior cruciate ligaments, medial collateral ligament, semitendinosus tendon and patellar tendon were harvested from New Zealand white rabbits. Cells grown from these tissues were then investigated for their susceptibility to genetic alteration by these vectors in vitro. Based upon their ability to convert cells in culture to a lacZ(+) phenotype, adenovirus was the most effective vector in short-term experiments. However, expression was transient. Although retrovirus gave lower initial transduction efficiencies, the percentage of transduced cells could be increased by the use of the selectable marker gene neo(r). In an in vivo marker study, we injected adenovirus into the rabbit patellar tendon. Transduced cells could be observed preferentially in the subsynovial layer at a declining frequency over a 6-week period. The allogeneic transplantation of in vitro retrovirally transduced fibroblasts into the patellar tendon resulted in a greater number of transduced cells. Although the number of lacZ(+) cells declined with time, positive cells were still present 6 weeks after transplantation. Furthermore, the transplanted cells, unlike cells transduced in situ with adenovirus, migrated from the injection site and integrated into the crimp of the tendon.

[Possibilities of gene therapy in traumatic and degenerative articular lesions. Current status of experimental and initial clinical applications]. / Möglichkeiten der Gentherapie bei traumatischen und degenerativen Gelenkläsionen. Aktueller Stand experimenteller und erster klinischer Anwendungen.

Soft tissue injuries often represent the greatest clinical problem. Not only do many of the most frequently injured tissues, such as the cruciate ligaments and articular cartilage, have very limited capabilities for spontaneous repair, but they also respond poorly to surgical or non-surgical intervention. In this article we try to define the role of growth factors in these conditions and to outline concepts for future treatment based upon modulation of the native repair response. We suggest that gene transfer could improve the management of such injuries, particularly when used as vehicles for the targetted delivery of growth factors.

One- versus two-incision technique for anterior cruciate ligament reconstruction with patellar tendon graft. Results on early rehabilitation and stability.

Anterior cruciate ligament (ACL) reconstruction with patellar tendon graft has become a standard procedure. The graft can be inserted either using two tunnels and a lateral femoral incision or with a femoral half-tunnel drilled from the joint, thus avoiding the lateral incision. Advantages have been claimed for the single-incision technique in the early rehabilitation period. Forty patients with ACL deficiency were included in a prospective randomized trial comparing the single- and two-incision technique with a follow-up period of 12 months. Preoperative data did not show any significant difference between the two groups. At early follow-up no differences were observed with respect to complications or the progress of rehabilitation. Evaluation at 12 months postoperatively using the IKDC form revealed good to excellent results in 70% of patients. ACL reconstruction reduced anterior translation of the knee significantly at the 6-month and 12-month follow-up with a slight increase of MMD values at 12 months in both groups. The arthroscopic single-incision technique did not differ from the mini-open technique in terms of postoperative pain medication, incidence of effusion, postoperative range-of-motion or any rehabilitation parameters. Stability was comparable in both groups at all time periods. We conclude that an arthroscopic single-incision technique has no advantage over a mini-open two-incision technique for ACL reconstruction with patellar tendon graft in terms of subjective or objective parameters.

[Endoscopic versus limited open technique for replacement of the anterior cruciate ligament. 4 years outcome of a prospective study]. / Endoskopische versus limitiert offene Technik für den Ersatz des vorderen Kreuzbandes. 4-Jahres-Ergebnisse einer prospektiven Studie.

ACL reconstruction with patellar tendon graft has become a standard procedure. The graft can be inserted either using two tunnels and a lateral femoral incision or with a femoral half tunnel drilled from the joint, thus avoiding the lateral incision. Advantages of the single-incision technique in the early rehabilitation period have been claimed. 40 patients with ACL deficiency were included in a prospective randomized trial comparing single and two-incision technique with a follow-up period of 4 years. Preoperative data did not show any significant difference between the two groups. At follow-up no difference were observed with respect to complications or he progress of rehabilitation. Evaluation after 1 and 4 years according to the IKDC form revealed good to excellent results in 70% of all patients. The Tegner-score increased significantly, however most patients did not regain their former activity level. ACL-reconstruction reduced anterior translation of the knee significantly at 6 months follow-up. However, we observed a slight increase of anterior translation after 1 and 4 years in both groups; stability was comparable in both groups at all time periods. We conclude that an arthroscopic single-incision technique has no advantage compared to a mini-open two-incision technique for ACL reconstruction with patellar tendon graft in terms of subjective or objective parameters.

Prehospital airway management in the acutely injured patient: the role of surgical cricothyrotomy revisited.

BACKGROUND: Ensuring an unobstructed airway and adequate oxygenation are first priorities in the resuscitation of the trauma patient. In situations of difficult endotracheal intubation, rapid sequence protocols frequently include the use of paralytic agents and cricothyrotomy for airway management. Recent literature findings suggest that the prehospital use of cricothyrotomy is too frequent. The purpose of this study was (a) to evaluate the efficacy of a rapid sequence intubation protocol without the use of paralytic agents, and (b) to determine the need for cricothyrotomy by using this protocol in the field. METHODS: We prospectively analyzed 383 acutely injured patients who were in need of airway control. Success rates, indications, and complications of endotracheal intubation and cricothyrotomy were analyzed. RESULTS: Successful orotracheal intubation on the scene with the use of this protocol was performed in 373 of 383 patients (97%). Two patients (0.5%) arrived at the trauma center with unrecognized esophageal intubation. Eight patients underwent cricothyrotomy in the field, six without previous attempts at intubation. CONCLUSION: Experienced emergency medical services personnel can effectively perform endotracheal intubation with narcotic analgesics without the use of paralytic agents in the field. With proper training for field airway management, cricothyrotomy in the field can be reduced to a few indications with high success rates.

Occurrence and distribution of free nerve endings in the distal iliotibial tract system of the knee.

Free nerve endings (FNE) are nociceptive sensory elements transmitting information on pain and inflammation from the connective tissues to the brain. They form an important part of the proprioceptive sensory system of the knee. We present a qualitative and quantitative analysis of FNEs in the distal iliotibial tract (ITT), documenting their occurrence in this structure as well as their specific distribution pattern. FNEs were found in all elements of the distal ITT, with their maximum density in the fixation sites of the distal ITT to the femur and the tibia. This finding correlates well with anatomical and biomechanical studies and stresses the importance of the deep ITT fibre system for lateral knee stability. The relative number of FNEs in the distal ITT ranges from 5 to 10 per 50 mm2 and is comparable to the frequency found in the synovial sheath of the cruciate ligaments. These findings have clinical implications for surgical procedures on the lateral side of the knee. The distinct anatomy of the distal ITT should be respected in all procedures, since extensive operations in this area may cause pain and loss of range-of-motion due to alterations of proprioceptive function.

[Virally mediated gene transfer in the patellar tendon. An experimental study in rabbits]. / Virusvermittelter Gentransfer in die Patellarsehne. Eine experimentelle Studie am Kaninchen.

Growth factors have the potential to enhance native repair responses in ligamentous and meniscal lesions. However, methods for applying these cytokines to sites of injury for extended periods are lacking. We suggest that local transfer of genes that encode the relevant healing factors merits investigation as a potential solution to this problem. In the present study, different viral vectors and liposomes are evaluated for their ability to deliver genes to cells of ligamentous and meniscal origin. The ACL, PCL, MCL, semitendinosus tendon, patellar tendon, and menisci were harvested from New Zealand white rabbits. Cells grown from these tissues were then investigated for their susceptibility to genetic alteration by these vectors. Based upon the ability of these vectors to convert cells in culture to a lacZ(+) phenotype, adenovirus was the most effective vector in short-term experiments. However, expression was transient. Although retrovirus gave lower initial transduction efficiencies, the percentage of transduced cells could be increased by the use of the selectable marker gene neo(r). Cells infected with adeno-associated virus containing the neor-gene could also be selected in this way. Liposomes showed low efficiency of gene transfer and expression. In an in vivo marker study, we injected adenovirus into the rabbit patellar tendon. Transduced cells could be observed preferentially in the subsynovial layer at a declining frequency over a 6-week period. The allogeneous transplantation of retrovirally transduced fibroblasts into the patellar tendon resulted in a greater number of transduced cells. Although the number of lacZ(+) cells declined with time, positive cells were still present 6 weeks after transplantation. Furthermore, the transplanted cells, unlike cells transduced in situ with adenovirus, migrated from the injection site and integrated into the crimp of the tendon.