Periprosthetic femoral fractures--incidence, classification problems and the proposal of a modified classification scheme.

INTRODUCTION: The increasing incidence of periprosthetic fractures correlates directly with the year-after-year increasing frequency of primary joint replacement surgery. The most common fracture localisation is the femur. The undisputed leader in frequency is the fracture that occurs around a total hip arthroplasty. Unfortunately, no general epidemiologic data exist dealing with exact fracture incidence numbers. Furthermore, existing classifications are lacking important information like time point of fracture occurrence, type of the implanted prosthesis and implantation technique (cemented vs. cementless). Additionally, information about mechanical quality of the bone structure and the fracture type are also missing in part. METHODS: We scanned the literature for adequate and widely used classifications in the field of hip and knee arthroplasty. In a next step we analyzed those classification systems in order to find out to what extent they are able to describe the specific aspects of the fracture event. Therefore we compared the existing classifications and presented their most relevant emphasis. Furthermore, we looked at our own patient population to evaluate incidence of fracture occurrence over time and percentage of loosened components. RESULTS: The existing classification systems address themselves specifically to the task of describing fracture localization and to some extent fracture type, or combine these two in order to calculate the possibility of loosening of the implanted prosthesis. Some of the important criteria like mechanical quality of the bone stock, primary implantation technique or time point of the prosthesis loosening (prior to or because of the fracture) remain ignored. The incidence of periprosthetic femur fractures at our department increased approximately 2.5 fold over the past two decades. The risk of suffering from a periprosthetic fracture was substantially higher after THA than after TKA. We observed a loose femoral component of the THA in about 45 % of the cases. Finally, we postulate the application of a modified classification for periprosthetic fractures as an alternative to the already published ones; not only for the femur, but also universally for all joints with an arthroplasty. CONCLUSION: The classification that is introduced in this study allows, in our opinion, a differentiated reflection of the given post-traumatic pathologic changes and enables the description of the fracture itself according to a generally accepted fracture classification scheme.

Do meta-analyses reveal time-dependent differences between the clinical outcomes achieved by microfracture and autologous chondrocyte implantation in the treatment of cartilage defects of the knee?

PURPOSE: To test the hypothesis that autologous chondrocyte implantation (ACI) has a better treatment effect than microfracture (MF), and increasing superiority over the years, when performed under similar patient-specific and defect-specific conditions. METHODS: We scanned four electronic databases for controlled clinical trials or controlled prospective observational studies. We conducted random-effects meta-analyses of equivalent data using standardized mean differences as the outcome measure of choice at 1, 2, and 5-year follow-up. We assessed heterogeneity with the I (2) index and publication bias with funnel plots and Kendall's tests. RESULTS: Our literature search revealed six study populations (nine papers) which satisfied our eligibility criteria. Overall, 399 patients aged between 16 and 60 years with 1-10 cm(2) chondral defects were available. The MF and the ACI study groups were well matched regarding patient baseline characteristics. For all papers, microfracture was performed according to Steadman, whereas three generations of ACI were applied. When all were combined, non-significant superiority of ACI over MF was revealed; surprisingly, this superiority decreased over the years. However, our meta-analyses combining solely second and third-generation ACI revealed significant standardized differences, becoming smaller over the years, but always representing a large effect. Nevertheless, our approximate estimate of the difference between the treatment effects provoked by second and third-generation ACI and by MF is not indicative of clinically relevant superiority of ACI over MF at 5-year follow-up. CONCLUSIONS: Both series of meta-analyses (combining either all ACI modifications or solely the second and third generations of ACI) suggest that the treatment effects resulting from ACI and MF converge over the years.

Obesity-related juvenile form of cartilage lesions: a new affliction in the knees of morbidly obese children and adolescents.

OBJECTIVES: Overweight and obesity are afflictions that lead to an increased risk of health problems including joint problems. The aim of the study was to assess the condition of articular cartilage in obese adolescent patients suffering from knee pain. METHODS: MRI of 24 knees of 20 morbidly obese patients, mean age 14.2 years, was performed in an open 1.0 Tesla MR system, where the cartilage, the quality and structure of the menisci, and the presence or absence of surrounding changes was examined. RESULTS: In all patients a cartilage lesion in at least one region of the knee could be detected. Retropatellar cartilage lesions have been found in 19 knees. Ten cartilage lesions grade I, and four lesions grade II have been described in the lateral compartment of the knee, whereas the medial compartment showed in eight cases a grade I, in 13 cases a grade II and in two cases a grade III cartilage lesion. Meniscal changes were assessed in most patients. CONCLUSION: Morbidly obese children and adolescents show major abnormalities in the articular cartilage of the knee. Whether obesity alone is the causal factor for the development of the pattern of these changes, remains to be seen. KEY POINTS: • Morbidly obese children and adolescents often suffer from knee pain • Prospective study showed cartilage and meniscal lesions in morbidly obese adolescents • MRI is an adequate tool for assessing cartilage lesions even in morbidly obese patients • It is unclear whether cartilage abnormalities are mainly due to mechanical overload.

Clinical outcome after microfracture of the knee: a meta-analysis of before/after-data of controlled studies.

PURPOSE: The aims of this study were to systematically review the medical literature, in order to find controlled studies about microfracture in the treatment of patients with full-thickness cartilage lesions of the knee, to statistically combine these studies in order to determine a best estimate of the average treatment effect, and to gather information to detect cartilage-specific and patient-specific factors that might have an influence on the clinical outcome. METHODS: We searched four electronic databases for controlled clinical trials or controlled prospective observational studies. We pooled before/after-data of study arms using the term microfracture. RESULTS: We calculated an overall best estimate of 1.106, with [0.566; 1.646] as 95% confidence interval of the mean standardized treatment effect for a representative patient population. CONCLUSIONS: Our meta-analysis revealed a clinically relevant improvement of the postoperative clinical status as compared to the preoperative status. An increase of 22 overall KOOS points may provide a rough estimate for the mean expected treatment effect achieved by microfracturing.

Biomechanical comparison of odontoid plate fixation versus odontoid screw fixation.

STUDY DESIGN: Randomized controlled trial with statistically significant difference or statistically no significant difference (Level I). OBJECTIVE: The purpose of this study was to measure the mechanical stability of odontoid plate fixation, using a specially designed plate construct and to compare the results with those after odontoid single-screw and double-screw fixation. SUMMARY OF BACKGROUND DATA: Plate fixation of the odontoid process without C1-C2 is a possible option for the management of odontoid fractures that are not suitable for conventional screw fixation. Although earlier biomechanical works have evaluated the effectiveness of different odontoid screw fixation techniques, no study has quantified the mechanical stability of odontoid fixation by a plate device. METHODS: The second cervical vertebra was removed from 15 fresh human spinal columns. The specimens were fixed to the experimental apparatus with the load cell at the articular surface of the odontoid process. In the first test series, stiffness and failure load of the intact odontoid were measured. Type II odontoid fractures were created by a 45 degree oblique extension loading at the articular surface of the odontoid process. Afterward, the specimens were randomly assigned to 1 of the following 3 groups: in group I (n=5), the fractures were stabilized, using a specially designed plate construct, in group II, the fractures were fixed, using two 3.5 mm cortical screws, and in group III, we used 1 regular 4.5 mm cortical screw. In the second test series, stiffness and failure load of the stabilized odontoid fractures were assessed for comparison and statistical analysis. RESULTS: Group I (plate device) showed a significantly higher mean failure load than group II and group III. The mean failure load of group I, after fixation of the odontoid fracture, was 84% of the mean failure load that was necessary to create a type II odontoid fracture initially. Comparing group II (double screw technique) and group III (single screw technique), there was no significant difference regarding the mean failure load. In both groups, the mean failure load after odontoid fixation was approximately 50% of the mean failure load of the intact odontoid. Statistical analysis also revealed a significantly higher stiffness of the stabilized odontoid after plate fixation than after single- or double-screw fixation. CONCLUSIONS: Plate fixation of the odontoid process for certain type II odontoid fracture patterns provided a significantly higher biomechanical stability than the technique of odontoid screw fixation. Using a specially designed plate construct fixed with 2 cancellous screws into the body of C2 and an additional cortical screw inserted in the odontoid process, 84% of the original stability of the intact odontoid was restored. Single- or double-screw fixation of the odontoid only restored approximately 50% of the original strength.

Physeal injuries of the proximal humerus: long-term results in seventy two patients.

PURPOSE: The aim of this study was to evaluate our treatment methods of proximal humeral physeal injuries retrospectively and elucidate the relationship between the trauma mechanism, the radiographic injury pattern, the consequent therapy and the functional outcome, and to further deduct and verify prognostic criteria. METHODS: At our Department of Trauma Surgery, 303 children and adolescent patients with fractures of the proximal humeral epiphysis were treated from 1992 to 2009. 72 cases were diagnosed as physeal fractures according to the Salter-Harris classification and were included in our study. RESULTS: 15 physeal fractures of the proximal humerus were reconstructed anatomically by open or closed reduction and produced 93.3% excellent results. 57 physeal fractures were treated in a conservative way and produced 94.7% excellent results. CONCLUSION: We state that epiphyseal injuries should to be treated depending on the age of the patient. This is the only way to decrease the rate of posttraumatic epiphysiodesis with consequent problems, including limb-length discrepancy and/or angular deformities.

Fractures of the head and neck of the femur in children: an outcome study.

Fractures of the head and neck of the femur in children are very rare, occurring only after a high-velocity trauma, e.g. a fall from a height. This analysis shows the clinical course of traumatic femoral head and neck fractures in paediatric patients. Predisposing factors for poor outcome or fracture complications, such as non-union or femoral head necrosis, are described. Between 1993 and 2006, 16 paediatric patients with proximal femoral fractures were treated at the Level One Trauma Centre of the Medical University of Vienna. The minimum follow-up was two years. Inclusion criteria were age less then 16 years, intact growth plate and a proximal femoral fracture according to the classification by Delbet and Colonna. Exclusion criteria were pathological fractures or fractures of the subtrochanteric region (6/16). Ten patients met the inclusion criteria. Two patients were lost to follow-up. Therefore eight patients were included in the study. All patients except one were operated upon within 48 h after the injury ("primary") and healed without further complications. A single case was managed by "secondary" surgical treatment, two weeks after the initial trauma resulting in femoral head necrosis that healed without any subjective complaints. This case series confirms the importance of early surgical fixation of proximal femoral fractures in paediatric patients. An operative intervention later then 48 h after the initial trauma may increase the risk of complications such as femoral head necrosis, particularly in Delbet type I fractures (traumatic slipped capital femoral epiphysis).

Acute compartment syndrome in children: a case series in 24 patients and review of the literature.

Trauma-associated acute compartment syndrome (ACS) of the extremities is a well-known complication in adults. There are only a handful of articles that describe the symptoms, the diagnostic procedure and treatment of ACS in children. The aim of this study was to analyse the diagnostic procedures in children compared to adolescents with ACS to obtain evidence for the diagnosis, treatment and outcome of children with ACS. Twenty-four children and adolescents with ACS have been treated at the Department of Trauma Surgery of the Medical University of Vienna, Austria. Two age-related groups were investigated to compare the diagnostic and therapeutic algorithm: group A comprising children aged 2-14 years (n = 12) and group B comprising adolescents aged 15-18 years (n = 12). Patient characteristics, diagnosis and therapy-associated data, complications and clinical outcome were analysed. In both groups we found fractures in most of our patients (n = 19) followed by contusion of the soft tissues (n = 3). In group A most of our patients were injured as pedestrians in car accidents (n = 5) followed by low-energy blunt trauma (n = 3). The most common region of injury and traumatic ACS was the lower leg (n = 7) followed by the feet (n = 3). For fracture stabilisation most of the patients (n = 6) received an external fixator. The mean time from admission to the fasciotomy was 27.9 hours. In four patients a compartment pressure measurement was performed with pressure levels from 30 to 75 mmHg. A histological examination of soft tissue was performed in five patients. From fasciotomy to definitive wound closure 2.4 operations were necessary. The mean hospital stay was 18.9 days. In group B most of our patients had a motorcycle accident (n = 5). The most common region for traumatic ACS in this group was also the lower leg (n = 9). In most of the patients (n = 6) intramedullary nails could be implanted. The mean time from admission to the fasciotomy was 27.1 hours. In six patients a compartment pressure measurement was performed with pressures from 25 to 90 mmHg. In five patients a histological examination was performed. From fasciotomy to definitive wound closure 2.3 operations were necessary. The mean hospital stay was 18.4 days. Secondary fasciotomy closure was performed in all cases. A split-skin graft was only necessary in three patients (13%). We avoided primary closure in the same setting when the fasciotomy was performed. Thus, we found no difference between the two groups in the diagnostic procedures, the indication for fasciotomy, the number of operations needed from fasciotomy to definitive wound closure, time of hospitalisation and clinical outcome. The rate of permanent complications was 4.2% (one patient from group A), which means that nearly all patients experienced full recovery after fasciotomy. ACS represents a surgical emergency and the indication should be determined early even in doubtful cases to avoid complications.

Surgery for pathological proximal femoral fractures, excluding femoral head and neck fractures: resection vs. stabilisation.

Pathological femoral head and neck fractures are commonly treated by arthroplasty. Treatment options for the trochanteric region or below are not clearly defined. The purpose of this retrospective, comparative, double-centre study was to analyse survival and influences on outcome according to the surgical technique used to treat pathological proximal femoral fractures, excluding fractures of the femoral head and neck. Fifty-nine patients with 64 fractures were operated up on between 1998 and 2004 in two tertiary referral centres and divided into two groups. One group (S, n = 33) consisted of patients who underwent intramedullary nailing alone, and the other group (R, n = 31) consisted of patients treated by metastatic tissue resection and reconstruction by means of different implants. Median survival was 12.6 months with no difference between groups. Surgical complications were higher in the R group (n = 7) vs. the S group (n = 3), with no statistically significant difference. Patients with surgery-related complications had a higher survival rate (p = 0.049), as did patients with mechanical implant failure (p = 0.01). Survival scoring systems did not correlate with actual survival. Resection of metastases in patients with pathological fractures of the proximal femur, excluding femoral head and neck fractures, has no influence on survival. Patients with long postoperative survival prognosis are at risk of implant-related complications.

Incidence and analysis of simultaneous bilateral radial head and neck fractures at a level I trauma center.

BACKGROUND: Reviewing the current literature, very few reports are given on simultaneous bilateral radial head and neck fractures. There are no reports on this entity's incidence. Thus, the purpose of this study was to analyze the incidence and outcome of simultaneous bilateral radial head fractures. METHODS: This study reviewed the clinical records and trauma database of this Level I Trauma Center and identified all adult patients with fractures of the radial head or neck who were admitted between 1992 and 2007. From a database of 2,296 adult trauma victims with radial head or neck fractures, an analysis of clinical records revealed 34 patients suffering from simultaneous bilateral injuries (68 fractures) being classified according to Mason. For clinical examination, range of motion, local pain, and activities of daily living were assessed. To quantify the clinical results, the patients were asked to grade their functional outcome according to the Mayo Elbow Performance Score (MEPS). RESULTS: The incidence of simultaneous bilateral fractures was 1.48%. Nonoperative treatment was performed in 86.8% (n = 59) of the cases. Solid bony union was achieved in all patients. Full satisfaction concerning treatment was achieved in 97% of the patients. The Mayo Elbow Performance Score showed an overall functional outcome score of 97.1. DISCUSSION: Reviewing the literature, the frequency of this injury was assessed for the first time. An incidence of 1.48% of all radial head fractures was explored. Our material was representative and included 2,296 injuries covering a 15-year period.

Management and outcome of periprosthetic fractures after total knee arthroplasty.

BACKGROUND: The incidence of periprosthetic fractures after total knee arthroplasty is continuously rising because of an increasing number of knee joint replacements and an enhanced survivorship of the elderly population after knee arthroplasty. The purpose of this study was to analyze the practicability and effectiveness of the various treatment methods for management of periprosthetic fractures after total knee arthroplasty, and to determine the clinical and radiographic long-term results of patients following surgical and nonoperative treatment of these injuries. METHODS: We reviewed the clinical and radiographic records of 41 patients (31 women and 10 men; average age, 78.6 years) with periprosthetic fractures after total knee arthroplasty between 1992 and 2008. Thirty-seven patients showed a periprosthetic fracture of the distal femur, and four patients had a periprosthetic proximal tibial fracture. Thirty-six patients underwent operative stabilization by plate fixation (n = 18), intramedullary nailing (n = 15) or revision arthroplasty (n = 3), and five patients were treated nonoperatively by long-term cast immobilization. RESULTS: Twenty-eight patients returned to their preinjury activity level and were satisfied with their clinical outcome. In 10 patients, we saw a relevant decrease of knee function and severe limitations in gait and activities of daily living. Three patients died related to surgery. Successful fracture healing within 6 months was achieved in 33 (87%) of 38 patients. Failures of reduction or fixation occurred in 8 (21%) of 38 patients. Reoperation due to technical failures was necessary in three patients. CONCLUSIONS: Compared with current data in literature, we had a satisfactory outcome in following individualized treatment of periprosthetic fractures after knee joint replacement. Referring to the wide field of treatment options and high rates of complications, periprosthetic femoral fractures around the knee commonly constitute a challenging problem for the treating surgeons and require an adequate analysis of fracture etiology and a corresponding transfer into an individual treatment concept.

Predictive factors influencing the outcome after gunshot injuries to the head-a retrospective cohort study.

BACKGROUND: Civilian gunshot injuries to the head are relatively rare in the irenical European Union, and studies of treatment and outcomes are seldom for this region in the current literature. METHODS: A cohort of 85 patients with civilian head gunshot injuries, who were admitted to our University hospital over a period of 16 years, was reviewed retrospectively. Clinical manifestation, computed tomography scan findings, and surgical treatment were described, with special regard to prognostic factors and outcome. RESULTS: The mean age was 48 years (range, 17.8-98.4 years), and 87% were men. Sixty patients sustained penetrating craniocerebral injuries (P-group) and 25, nonpenetrating gunshot wounds (NP-group). The overall mortality was 87% in the P-group and 4% in the NP-group. The Glasgow Coma Scale (GCS) score at admission was recorded to be 3 to 5 in 58 patients (96%) and 7 patients (28%) in the P-group and NP-group, respectively. Only 8 patients (13%) survived in the P-group compared with 24 patients (96%) in the NP-group. Excluding wound debridement, there were 16 surgical procedures in the P-group and 8 in the NP-group, with a mortality rate of 63% and 13%, respectively. CONCLUSIONS: Glasgow Coma Score at admission and the status of pupils and hemodynamic situation seem to be the most significant predictors of outcome in penetrating craniocerebral gunshot wounds. Computed tomography scans, bi- or multilobar injury, and intraventricular hemorrhage were correlated with poor outcome. Patients with a GCS score >8, normal pupil reaction, and single lobe of brain injury may benefit from early aggressive management.

Physeal injuries of the distal tibia: long-term results in 376 patients.

The aim of this study was to evaluate our treatment of distal tibial physeal injuries retrospectively and explain the relationship between the trauma mechanism, the radiographic injury pattern, the subsequent therapy and the functional outcome, as well as to further deduce and verify prognostic criteria. At the Department of Trauma Surgery, Vienna Medical University, 419 children and adolescent patients with physeal injuries of the distal tibia were treated from 1993 to 2007, of these 376 were included in our study and evaluated retrospectively. Seventy-seven displaced physeal fractures of the distal tibia were reconstructed anatomically by open or closed reduction and produced 95% excellent results. A perfect anatomical reduction, if necessary by open means, should be achieved to prevent a bone bridge with subsequent epiphysiodesis and post-traumatic deformities due to growth inhibition and/or retardation.

Dedifferentiation of human articular chondrocytes is associated with alterations in expression patterns of GDF-5 and its receptors.

Human articular chondrocytes are expanded in monolayer culture in order to obtain sufficient cells for matrix-associated cartilage transplantation. During this proliferation process, the cells change their shape as well as their expression profile. These changes resemble those that occur during embryogenesis, when the limb anlagen form the interzone that later develops the joint cleft. We analysed the expression profile of genes that are reportedly important for these changes during embryogenesis within the dedifferentiation process of adult articular chondrocytes. We found GDF-5, BMPR-Ib and connexin 43 up-regulated, as well as a down-regulation of BMPR-Ia and noggin. Connexin 32 could not be detected in either native cartilage or in dedifferentiated cells. The newly synthesized proteins were detected by immunofluorescence. There is evidence from our results that dedifferentiated chondrocytes resemble the cells from the interzone in developing synovial joints.

Alterations in CD44 isoforms and HAS expression in human articular chondrocytes during the de- and re-differentiation processes.

The purpose of this study was to investigate the expression of different CD44 and hyaluronan synthase isoforms in cartilage, their alterations during the chondrocyte dedifferentiation process in monolayer culture and during the redifferentiation process on 3D scaffolds. Chondrocytes isolated from human articular cartilage were cultured as a monolayer for up to 36 days and were seeded on two different 3D scaffolds (HYAFF 11 and Bio-Gide). Expression levels of CD44s, CD44-lt, CD44-st, HAS1, HAS2, HAS3 and UDPGD were determined by real-time RT-PCR at different time points. At the protein level CD44 and CD90 were analyzed by flow cytometry. HAS2 was found to be the predominantly expressed hyaluronan synthase in chondrocytes and was not subjected to any regulation during the dedifferentiation process. CD44s, CD44-lt, CD44-st and UDPGD, however, were upregulated immediately after cell isolation. In addition, a high cell density was found to significantly increase CD44-st and CD44-lt expression. Redifferentiation on 3D scaffolds reversed the increase of the CD44 expression. Our data point out that CD44 expression does not correlate with matrix assembly in chondrocytes and that CD44 has a regulatory function in chondrocytes, not necessarily on differentiation, but probably on proliferation.

Angular stable fixation of proximal humeral fractures.

BACKGROUND: Proximal humeral fractures requiring surgical stabilization remain a therapeutic challenge. High rates of treatment-related complications have been reported to be associated, particularly in elderly patients with unstable fracture types and diminished bone quality. In recent years, angular stable implants have been introduced to improve the patients' outcome. The purpose of this study was to assess the clinical and radiographic long-term results after angular stable plate fixation of proximal humeral fractures at this Level I trauma center, with special emphasis on fracture healing, functional outcome and treatment related complications. METHODS: We retrospectively analyzed functional and radiographic results of 42 patients (average age: 57.8 years) after angular stable plate fixation of proximal humeral fractures at an average time of 3.2 (+/-0.8) years after trauma. Functional results were defined by the Constant shoulder score (CS) and the individual Constant score (CSindiv). Radiographic results were assessed by a three-view trauma series (anteroposterior, lateral, and axillary view). For operative treatment, two different angular stable implants were used. Twenty-seven patients were stabilized by a HOFER plate, fifteen patients by a Locking Proximal Humerus Plate. RESULTS: Clinical results revealed an average CS of 74.0 points and an average individual CSindiv of 79.2% points. Fourteen patients had an excellent functional outcome, eight patients a good outcome and fourteen patients had moderate functional results. Six patients (14%) had a poor outcome with less than 55% on CSindiv. Regarding the radiographic outcome, we had an overall union rate of 95% (40 of 42). Failures of reduction and fixation occurred in fourteen patients (33%), and in nine patients (21%) we had signs of a humeral head necrosis. Re-operation due to treatment-related complications was necessary in two patients (5%). Statistical analysis revealed that the fracture type and the age of the patients had a significant influence on the clinical outcome and on the incidence of treatment-related complications. CONCLUSION: With regards to fracture healing and functional outcome of the patients, we had a satisfactory outcome after angular stable plate fixation of proximal humeral fractures. However, we experienced a notably high rate of technical failures and partial humeral head necrosis. Advanced surgical skills and experiences are necessary to achieve correct anatomic reduction and implant fixation, to reduce the risk of these treatment-related complications.

Mason type-I radial head fractures and interosseous membrane lesions--a prospective study.

BACKGROUND: The role of the forearm interosseous membrane (IOM) in trauma remains not fully understood. Information from experimental models simulating sudden axial loading of the IOM is limited. The results from several cadaver studies are controversially discussed in literature. Pronation and supination of the forearm as well as varus and valgus position of the elbow joint have been suspected to have influence on the injury pattern. The purpose of the current study, therefore, was to further investigate the role of the IOM in trauma mechanism. METHODS: We prospectively screened the forearms of 14 patients with Mason type-I radial head fractures for additional occult IOM lesions. The fractures were classified according to the Mason classification using plain radiographs. All patients were subjected to forearm magnetic resonance imaging visualizing the entire IOM within a week. Treatment consisted of nearly total immobilization of the elbow joint using a special elastic and gauze bandage for 7 days followed by an early motion recovery program. RESULTS: Partial disruptions of the distal part of the IOM were found in nine cases. The biomechanically essential interosseous ligament was not attained by these ruptures in any of the cases. None of the patient had the classical findings of the Essex Lopresti lesion. All patients had regular roentgenograms of both wrists. Patients were asymptomatic at the time of a 4-week follow-up. CONCLUSION: Our results suggest that injuries of the IOM are more frequent than generally expected. The findings support the conclusions of some of the previous cadaver studies. If IOM lesions are suspected, magnetic resonance imaging tomography should be performed.

Surgical treatment of pathological fractures of the shaft of the humerus.

BACKGROUND: This report deals with the advantages and disadvantages associated with the most commonly used methods of stabilization after a pathologic fracture of the humerus shaft. PATIENTS: A total of 39 patients with 41 metastatic lesions and pathologic fractures of the humerus, treated surgically between 1992 and 2007, were retrospectively analyzed. RESULTS: The rate of local complications was 14.6% (6 of 41). Radial nerve injury was the only local complication and was exclusively observed in patients who underwent open reduction and plate fixation. The overall rate of osteosynthesis failure was 12.2% (5 of 41). Two failures were observed in 21 patients with open reductions and plate fixations, compared with three failures in 20 procedures involving closed reductions and intramedullary stabilization. The 1- and 2-year survival rates were 0.35 and 0.2 in ORIF and 0.07 and 0 in patients with IM fixation retrospectively. CONCLUSION: Intramedullary stabilization is a reliable method for fixation of pathologic fractures of the humerus diaphysis for patients in the advanced stage of metastatic disease. ORIF are preferable to IM fixations for the treatment of metaphyseal fractures and for those patients with a solitary metastasis in the humerus or those with a better prognosis.

Surgical treatment of metastatic fractures of the femur: a retrospective analysis of 142 patients.

BACKGROUND: Pathologic fractures of long bones are common complications of the metastatic disease; however, the influence of the primary tumor, the stage of metastatic disease, different surgical techniques, and the postoperative mobility on the postoperative survival has not been clearly defined. The aim of this retrospective study was to evaluate outcome after surgical treatment for pathologic femur fractures. PATIENTS AND METHODS: A consecutive series of 142 patients with metastatic fractures of femur were retrospectively studied. The operative treatment was based on intramedullary fixation (n = 94), gliding screws (n = 15), other extramedullary fixation devices (n = 7), and arthroplasty (n = 23). RESULTS: Seventeen percent and 6% of the patients survived 1 year and 2 years, respectively, postoperatively. Postoperative survival was higher in patients with pathologic femur fractures because of breast carcinoma than in patients with other primary tumors. The rate of complications for patients with intramedullary stabilization, gliding screw fixation, and endoprosthetic replacement was 3.2%, 20%, and 8.6%, respectively. CONCLUSION: Although many studies describe the endoprosthetic replacement as the safer method to treat pathologic femur fractures, our data showed that intramedullary stabilization and endoprosthetic replacement to be safe, and equivalent alternatives to treat complete pathologic fractures of the femur in patients with advanced metastatic disease.

Biomechanical comparison of modified Kessler and running suture repair in 3 different animal tendons and in human flexor tendons.

PURPOSE: To establish the animal flexor tendon that best mimics the biomechanical performance of human flexor tendons. We investigated the biomechanical behavior of core and running sutures in 3 different animal flexor tendons and in human flexor tendons. Additionally, we attempted to help standardize future flexor tendon studies. To that purpose, nearly all variables occurring in the test setup have been highlighted. METHODS: The species selected were pig, calf, sheep, and human. Two groups were formed. In the first group we tested 3-0 core sutures (Ticron; Tyco Healthcare, Vienna, Austria), and in the second group we tested 5-0 running sutures (Ethilon; Ethicon, Vienna, Austria). In each group, 10 tendons of each specimen were tested, which yielded a total of 80 tendons. In each group, the repaired tendons were subjected to 3,000 linear load cycles at a load of 15 N. At the end of this procedure, final gap values were recorded. In the next step, ultimate load-to-failure data were obtained from each specimen. RESULTS: Core sutures behaved similarly in the human, sheep, and pig tendons with respect to ultimate loads. With respect to gap formation, core sutures behaved similarly in the human, sheep, and calf tendons. Deep running sutures behaved similarly in the human, sheep, and pig tendons in terms of ultimate load to failure. CONCLUSIONS: In this study, sheep tendons were found to best mimic the biomechanical behavior of human tendons. Calf tendons seem to be unsuitable. There is a strong need for consistency in biomechanical test setups.