Learning the skills needed to perform shoulder arthroscopy by simulation

INTRODUCTION

Simulation for arthroscopy helps surgical trainees develop their surgery skills in a safe environment. This teaching technique has become more widespread in recent years because of the need to provide surgeons in training with an alternative to the current methods. We hypothesized that a resident in surgery could acquire the skills needed to perform arthroscopic shoulder surgery by working on a simulator.

MATERIAL AND METHODS

The study was conducted over a 4-month period from June to September 2016. All the surgeons and residents in our department participated in the study. We recorded each participant's age, sex, dominant hand, and video gaming experience. We used the Arthro Mentor™ simulator from Simbionix (now 3D Systems). Testing was carried out at the start and end of training to evaluate the participant's skills and their progression. The changes were evaluated statistically.

RESULTS

Fourteen surgeons were included in the study. They were split into two groups: controls and residents. There was a statistically significant improvement in the intern group between the overall pre-test score and the overall post-test score. There was no significant improvement in the overall score of the control group between the pre-test and post-test.

DISCUSSION

For surgeons in training, shoulder arthroscopy simulation helps them acquire the skills needed to perform arthroscopy such as hand-eye coordination, triangulation and the ability to work in three-dimensions based on two-dimensional visual information. We believe that the benefit of simulation resides in learning the skills needed to perform a surgical procedure, not in learning the procedure itself.

LEVEL OF EVIDENCE

III-case-control study.

Pyoderma gangrenosum or necrotising fasciitis? Diagnostic and therapeutic wanderings

A case of post-traumatic lower-limb pyoderma gangrenosum (PG) in a 77-year-old female is reported. The diagnosis of PG is frequently one of exclusion, and it is therefore unsurprising that the condition was initially mistaken for necrotising fasciitis then for necrotising bacterial dermo-hypodermitis. Medical and surgical treatment for those conditions proved ineffective. This fact, together with the atypical presentation, promoted a re-evaluation of the diagnosis. The clinical findings and investigation results converged to suggest PG, and a therapeutic trial was initiated. The good treatment response and negative findings from tests for other conditions established the diagnosis of post-traumatic PG.

Endoscopic ulnar nerve release at the elbow: Indications and outcomes

BACKGROUND

Ulnar nerve entrapment at the elbow is the second most common nerve entrapment syndrome at the upper limp, after carpal tunnel syndrome. Many surgeons feel that ulnar nerve instability contra-indicates endoscopic nerve release. Published studies, however, found no evidence that pre-operative or intra-operative ulnar nerve instability adversely affected clinical outcomes. The objective of this prospective study was to define the indications and describe the outcomes of endoscopic ulnar nerve release at the elbow.

HYPOTHESIS

Endoscopic ulnar nerve release at the elbow is a valid option even in patients with ulnar nerve instability and regardless of the severity of the compression.

MATERIAL AND METHODS

We conducted a prospective single-centre study of patients scheduled for surgery based on clinical and electromyographic manifestations of ulnar nerve entrapment at the elbow. Ulnar nerve instability (incomplete dislocation, i.e., Childress A) before or during surgery was not a contra-indication to the procedure. The patients were re-evaluated 12 months after surgery.

RESULTS

Seventeen patients were included in the statistical analysis. The modified Bishop's score indicated excellent or good outcomes in 15 (88%) patients (excellent in 4 and good in 11) and a fair outcome in 2 patients. Functional outcomes were not associated with the presence of ulnar nerve instability before surgery.

DISCUSSION

We elected to include patients with Childress A ulnar nerve instability. Clinical outcomes in these patients were similar to those in patients without ulnar nerve instability.

LEVEL OF EVIDENCE

IV, open prospective study of treatment outcomes.

Treatment of comminuted distal radius fractures by resurfacing prosthesis in elderly patients

In elderly patients, distal radius fractures are often associated with osteoporotic bone. Under these conditions, anatomic resurfacing implants may provide satisfactory results in terms of range of motion, pain and function. Between July 2009 and January 2012, eight elderly patients were treated with the SOPHIA™ implant at our hand surgery department. Inclusion criteria were isolated comminuted distal radius AO type C2 fractures in patients greater than 70 years of age. All patients were reviewed in February 2013 by an independent surgeon. Clinical, functional and radiographic assessments were performed. Mean follow-up was 25 months (range 17-36 months). Mean ROM was 45° (range 40-50°) in flexion and 44° (range 40-50°) in extension. Mean pronation-supination range was 160°. Mean grip strength was 18 kgf. Mean Quick DASH was 18.2/100 (range 6.82-29.55) and mean pain on VAS was 2.33 (range 0-4). X-rays did not reveal any implant loosening or ulnar translation of the carpus. Use of a wrist resurfacing implant led to rapid recovery of autonomy in elderly patients with comminuted distal radius fractures. It parallels the use of shoulder or elbow prostheses for complex joint fractures in the elderly.

Surgical management of recurrent dislocation after total hip arthroplasty

Dislocation is a major complication of total hip arthroplasty (THA), whose frequency has been unaffected by improvements in surgical techniques and implants. The dislocation rate depends on multiple factors related to the patient, hip disease, and surgical procedure and is therefore also dependent on the surgeon. The many published studies on THA dislocation, its causes, and its treatment have produced conflicting results. The objective of this work is to review the management of THA dislocation, which is a severe event for both the patient and the surgeon. This lecture starts with a brief review of data on THA dislocation rates and the many factors that influence them. Emphasis is then put on the evaluation for a cause and, more specifically, on the challenges raised by detecting suboptimal cup position. Next, reported techniques for treating THA dislocation and the outcomes of each are discussed. Finally, a management strategy for patients selected for revision surgery is suggested.

Distal humerus fractures in patients over 65: complications

INTRODUCTION

Fractures of the distal humerus in patients over the age of 65 remain a therapeutic challenge. Treatment options include conservative treatment, internal fixation or total elbow arthroplasty. The complications of these different treatment options were evaluated in a multicentre study.

MATERIALS AND METHODS

Four hundred and ninety-seven medical records were evaluated. A retrospective study was performed in 410 cases: 34 received conservative treatment, 289 internal fixation and 87 underwent total elbow arthroplasty. A prospective study was performed in 87 cases: 22 received conservative treatment, 53 internal fixation, and 12 underwent total elbow arthroplasty. Patients were evaluated after at least 6 months follow-up.

RESULTS

The rate of complications was 30% in the retrospective study and 29% in the prospective study. The rate of complications in the conservative treatment group was 60%, and the main complication was essentially malunion. The rate of complications was 44% in the internal fixation group and included neuropathies, mechanical failure or wound dehiscence. Although complications only developed in 23% of total elbow arthroplasties, they were often more severe than those following other treatments.

DISCUSSION

Complications develop in one out of three patients over 65 with distal humerus fractures. Three main types of complications were identified. Neuropathies especially of the ulnar nerve, especially during arthroplasty, must always be identified, the nerve requiring isolation and transposition. Bone complications, due principally to mechanical failure, were found following internal fixation. Despite technical progress, care must be taken not to favor excessive utilization of this treatment option in complex fractures on fragile bone. Although there were relatively fewer complications with total elbow arthroplasty they were more difficult to treat. Ossifications were frequent whatever the surgical option and can jeopardize the functional outcome.

Epidemiology of distal humerus fractures in the elderly

INTRODUCTION

Despite recent treatment advances, management of distal humerus fractures in the elderly remains one of the most challenging aspects of trauma surgery. Although these fractures are relatively rare, they fall under the umbrella of osteoporotic fractures, which themselves are increasing in frequency.

MATERIAL AND METHODS

Two studies were performed: one retrospective study of 410 patients over a 10-year period and one prospective study of 87 patients over a 1.5-year period. This allowed us to analyse the epidemiology of distal humerus fractures in subjects above 64years of age in 19 different French hospitals. All of the included patients were reviewed, except for one subject in the retrospective study who had died, but whose data was still used.

RESULTS

Most of the fractures were AO type C, occurred in women in more than 80%, and occurred in nearly one of two persons above 80 years of age. Most of the patients had a high level of autonomy and lived at home. Unlike other upper limb fracture sites, nearly 90% of patients required surgical treatment. The presence of osteoporosis was found to have a tremendous impact on fracture care, complications and results.

CONCLUSION

Functional status is more important than chronological age in this patient population; the former must be taken into account when determining treatment indications.

LEVEL OF EVIDENCE

Level IV.

Percutaneous iliosacral screw fixation in unstable pelvic ring lesions: the interest of O-ARM CT-guided navigation

INTRODUCTION

The reference surgical treatment for unstable posterior pelvic fracture is percutaneous iliosacral screw fixation, isolated or in association with other techniques. As there is a risk of passage outside the bone when performing screw fixation under fluoroscopy, new image-guidance techniques have been developed: fluoronavigation, peroperative 3D navigation, CT-linked navigation, etc. Since September 2011, our department has performed iliosacral screw fixation under CT control linked to navigation so as to optimize screw positioning. This innovative technology has been used in neurosurgery in our center since 2007, for disc implants, spinal fracture, vertebral arthrodesis and intracerebral localization.

MATERIAL AND METHODS

Six patients were treated by iliosacral screw fixation for posterior pelvic ring fracture lesion. The O-ARM (Medtronic(®)) computer-assisted surgical navigation system was used, combining surgical navigation and peroperative 3D imaging. This kind of osteosynthesis is suitable for non-displaced or prereduced fracture. A radiation dose report is drawn up at end of surgery.

DISCUSSION

Postoperative course does not differ from other percutaneous osteosynthesis techniques, combing the advantages of a percutaneous approach (reduced infection and blood-loss rates, etc.) while optimizing iliosacral screw positioning. To date, no radiation overexposure has been found.

CONCLUSION

The precision and safety of iliosacral screw fixation are now unequalled, meeting the basic computer-assisted surgery principles of reduced morbidity without overexposure to ionizing radiation. Indications for computer-assisted surgery should therefore be extended to iliosacral pathologies (arthritic, tumoral and inflammatory), non-displaced acetabular fracture, etc.

Percutaneous fixation of tibial plateau fractures under arthroscopy: a medium term perspective

INTRODUCTION

Arthroscopically assisted percutaneous internal fixation has found its place in the treatment of Schatzker I-III tibial plateau fractures, with good short-term results reported. The objective of this study was to observe the progression of osteoarthritis at the medium term through clinical and radiological assessment.

PATIENTS AND METHODS

Twenty-seven patients were treated with arthroscopy-assisted percutaneous fixation for stage I-III Schatzker tibial plateau fractures.

RESULTS

Twenty-one patients were reviewed with a mean follow-up of 59.5 months (range, 24-138 months); satisfaction was good except for return to sports activity. The mean IKS score was 85.2 for the knee score and 91 for function. The mean Lysholm score was 86 points, with a mean Tegner activity score of 4. A mean score of 25.5 and 8 points was found for the clinical and radiological Rasmussen scores, respectively; 47.6% of the patients presented early osteoarthritis on radiological evaluation.

DISCUSSION

The medium-term functional results were comparable to the short-term results. The patients were satisfied except for return to sports activity. Age at surgery appears as a prognostic factor for osteoarthritis.

CONCLUSION

Arthroscopic internal fixation remains the technical reference for Schatzker I-III tibial plateau fractures despite the appearance of osteoarthritis, which remains less extensive than in open surgery.

LEVEL OF EVIDENCE

Level IV. Retrospective study.

Extension fractures of the distal radius in patients older than 50: a prospective randomized study comparing fixation using mixed pins or a palmar fixed-angle plate

We randomized 103 patients over the age of 50 with an unstable closed intra- or extra-articular dorsally displaced distal radius fracture to have either palmar fixed-angle plating (n=50) or 'mixed pinning' (n=53) and compared the clinical and radiological outcomes at 3, 6, 12 and 26 weeks after surgery in a prospective study. Postoperative palmar tilt was significantly better in those stabilized with K-wires, but loss of reduction was statistically less in those stabilized with a plate. At 26 weeks, functional results, assessed by DASH and Herzberg scores, were better in those fixed with a plate.

[Intra-articular fracture of the distal humerus: outcome after osteosynthesis in patients over 60]

PURPOSE OF THE STUDY

This is a retrospective analysis of patients aged over 60 years treated in a single center for intra-articular fractures of the distal humerus. Outcomes were compared with published results for osteosynthesis and arthroplasty.

MATERIAL AND METHODS

The cohort included 34 patients (36 fractures) reviewed at mean 35 months. Mean age was 77.6 years. Fracture types were: C1: 8, C2: 10, C3: 18. The transtricipital posteromedial approach was used in the majority of patients. Fixation was achieved with a prebent lateral plate (n=11 fractures), a Y-plate (n=9), two plates (n=4), pins or screws (n=9) and an external fixator (n=3). Outcome was assessed with the Mayo elbow score, the Bröberg radiographic score and patient satisfaction. The social impact was also noted.

RESULTS

The mean Mayo elbow score was 73.3; outcome was excellent (n=13), good (n=8), fair (n=5) and poor (n=10). Pain persisted in 23 patients. The mean range of movement was 80 degrees . Patient satisfaction remained good. Ten patients did not recover their preoperative level of autonomy. Radiological signs of osteoarthritis were noted for 75% of patients and nonunion of the humeral fracture in 32%. There were three superficial infections and four neurological lesions.

DISCUSSION

Good and very good outcome was noted for 59% of the osteosyntheses in this series, compared with 71% in the literature. The rate for arthroplasty is 95%. The mean range of motion is 101 degrees , 17% of patients with a prosthesis complain of pain, 5% develop a superficial infection and 6.5% suffer neurological injury. The estimated rate of revision for arthroplasty is 11% at 7 years.

CONCLUSION

Beyond the age of 65 years and based on evidence reported in the literature, it would be advisable to prefer another mode of treatment for these intra-articular fractures, for example elbow arthroplasty, particularly for comminutive fractures on osteoporotic bone.

Non-invasive imaging correlates with histological and molecular characteristics of an osteosarcoma model: application for early detection and follow-up of MDR phenotype

BACKGROUND

In an orthotopic rat osteosarcoma model, histological and molecular findings were compared with the results of non-invasive imaging methods to assess disease progression at the primary site, the pattern of metastatic dissemination and the chemoresistance phenotype.

MATERIALS AND METHODS

Primary tumor engraftment, vascularization, growth and metastatic spread were evaluated using 18FDG tomoscintigraphy. Bone neoformation in the primary tumor and metastasis was determined using 18FNa confirmed by classical histological studies. Chemoresistance phenotype was assessed by analysis of MDR1 and MRP1 genes expression compared to 99mTc MIBI imaging.

RESULTS

99mTc MIBI imaging correlated with the overexpression of the MDR1 and MRP1 genes. 18FDG, 18FNa and 99mTc tomoscintigraphies revealed that the pattern of vascularization, bone neoformation and hematogeneous metastatic dissemination in our animal model mimics its human counterpart.

CONCLUSION

Multimodality, non-invasive imaging is a valid surrogate marker of histological and molecular characteristics in an orthotopic osteosarcoma model in immunocompetent rats; it allows extensive in vivo follow-up of osteosarcoma, including longitudinal analysis of chemoresistance.

Comminuted fractures of the radial head treated by the Judet floating radial head prosthesis

Excision is not a suitable treatment for all comminuted fractures of the radial head. In elbows where instability can be predicted, a replacement arthroplasty of the radial head is more effective. The aim of this paper was to present the medium-term results of the Judet floating radial head prosthesis.

This operation was performed on 14 patients between 1992 and 2003, of whom 12 were reviewed at a mean follow-up of five years and three months (1 to 12 years). The outcome was assessed using the Mayo elbow performance score and a modified Disability of Arm Shoulder Hand (DASH) questionnaire. There were six excellent results, four good, one fair and one poor, as graded by the Mayo score. The mean DASH score was 23.9/100 (0 to 65.8/100). The only significant complication occurred in one patient who developed a severe complex regional pain syndrome. There were no patients with secondary instability of the elbow, implant loosening, cubitus valgus, osteoporosis of the capitellum, or pain in the forearm and wrist. Our experience, combined with that of other authors using this device, has encouraged us to continue using the Judet prosthesis in comminuted fractures of the elbow where instability is a potential problem.

[Perforation of the sigmoid colon secondary to acetabular fracture]

Traumatic lesions of the colon associated with fracture of the acetabulum occurs in less than 2% of the cases. Direct perforation of the colon by a bony spike, which occurred in our patient, is even more exceptional. We were unable to find any other case reported in the literature. This case illustrates the importance of looking for intestinal lesions in all patients with pelvic injury presenting an unexplained infectious syndrome. Imaging provides clear evidence for avoiding late diagnosis and life-threatening situations.

[Extra-spinal cause of recurrent sciatalgia after disk surgery: a case report]

There is a general consensus concerning the clinical and radiological approach to diagnosis and proper management strategy in patients with sciatalgia subsequent to disk herniation. Recurrent herniation is the most probable diagnosis when pain recurs the same territory long after surgery. Despite advances in computed tomographic and magnetic resonance imaging, it may be difficult to identify the real source of the pain in some patients. We report a patient with renal cell cancer who developed recurrent sciatic pain which did not respond to disk surgery. This case illustrates the need for an extensive work-up before implicating the spine as the cause of recurrent sciatalgia.

Effects of alumina and zirconium dioxide particles on arachidonic acid metabolism and proinflammatory interleukin production in osteoarthritis and rheumatoid synovial cells

We describe a model which can be used for in vitro biocompatibility assays of biomaterials. We studied the in vitro response of human osteoarthritis or rheumatoid arthritis fibroblast-like synoviocytes to Al2O3 or ZrO2 particles by analysing the production of interleukin-1 (IL-1) and interleukin-6 (IL-6) and the metabolism of arachidonic acid via lipoxygenase and cyclo-oxygenase pathways. Our results show that, in these cells and under our experimental conditions, Al2O3 and ZrO2 did not significantly modify the synthesis of IL-1 and IL-6 or the metabolism of arachidonic acid.

[Long-term 10-year outcome after chemonucleolysis for lumbar disc herniation]

PURPOSE OF THE STUDY

We studied the efficacy of papaine for treatment of herniated discs at a mean 10-year follow-up and compared results with other series and other treatments.

MATERIAL AND METHODS

From an initial group of 160 patients, 96 patients, 53 men and 43 women, mean age 39 years, were selected for evaluation. These patients had 46 L4L5 herniations and 50 L5S1 herniations. All 96 patients were operated in the same department and received the same dose of papaine under the same anesthesia conditions. All patients were followed regularly to 3 months postoperatively then were reviewed 3 to 17 years after surgery. Inquiries were made about return to work, pain, and activity. Physical examination and x-rays were obtained for all patients.

RESULTS

There were no neurological complications in our series. Seventeen patients required a second procedure for sciatic pain. Most of the patients continued their normal occupational and social activities after papaine treatment, but many of them had chronic lumbar pain.

DISCUSSION

Our results were comparable with series reporting a similar long follow-up. Surgery is more efficient than papaine but long-term results are equivalent.

CONCLUSION

Chemopapaine treatment provided good long-term results in our patients, similar to surgery. Chemonucleolysis may be employed as first line treatment for young patients with non-excluded disc herniation with sciatic pain.

[Tibio-talar arthrodesis: long term influence on the foot]

PURPOSE OF THE STUDY

The aim of this study was to evaluate the long-term effect of tibiotalar arthrodesis on function, clinical and radiological tolerance, and subtalar joints.

MATERIAL AND METHODS

We reviewed 37 cases of tibiotalar arthrodesis in 27 young patients who were generally manual workers. Their mean age at surgery was 46 years and mean follow-up at review was 12.8 years (range 5-26 years). Functional outcome was assessed with the Duquennoy scale. We reviewed the anterioposterior and lateral weight-bearing views as well as the lateral view in dorsal and forced plantar flexion.

RESULTS

Mean functional outcome was good and very good in 66% of the cases, fair in 30% and poor in one case. Total pain relief had been achieved in 45% of the cases with a mean walking distance of 1500 m without crutches. Residual mobility at last follow-up was 13 degrees for the mediotarsal joint. This mobility allowed the arthrodesed foot to adapt to gait. Radiologically, fusion had been achieved in 83% of the cases within 3 months. The overall functional score fell off proportionally with the degree of arthrodesis valgus starting at 5 degrees. Likewise pes equinus > 10 degrees led to pain and reduced motion. The subtalar joints were affected in all cases, leading to poor adaptation of the foot on uneven ground. Grade 1 osteoarthritis affected the mediotarsal joint and was more marked in case of equine fixation.

DISCUSSION

Our results are similar to those reported in the literature. We had 4 cases of nonunion in patients with risk factors previously discussed in the literature.

CONCLUSION

Arthrodesis remains a useful method for treating talocrural osteoarthritis, providing good long-term results. The position of the fixation should be 90 degrees in the sagittal plane and 0 degrees to 5 degrees valgus in the frontal plane.

[Aneurysmal bone cyst of the patella. A case report and literature review]

We report a case of an aneurysmal cyst localized in the patella of a 37-year-old man. The lesion was secondary to a chondroblastoma at six years follow-up after initial curettage and bone graft. It were no recurrence. Treatment of aneurysmal cysts depends on the degree of articular involvement. We made a detailed study of 11 cases of this rare localization of aneurysmal cysts reported in the literature.

Interactions of hydroxyapatite and fluorapatite particles on human osteoarthritis type B synoviocytes: effects on interleukin-1 alpha levels and lipoxygenase pathways

We investigated the effects of the biomaterials hydroxyapatite (HAP) and fluorapatite (FAP) on cultured human osteoarthritis type B synoviocytes by analyzing interleukin-1 alpha (IL-1 alpha) production and arachidonic acid metabolism via lipoxygenase pathways. A portion of opsonized particles was endocytosed and was found in numerous phagolysosomes in human synoviocyte cytoplasms. The present study demonstrates that HAP and FAP calcined at 700 degrees C induced a decrease in IL-1 alpha production but markedly decreased the synthesis of lipoxygenase products after 1-month incubation with the particles. This model will allow us to study the possible inflammatory response (arachidonic acid metabolism, proinflammatory cytokines) that can be induced by any biomaterials used in orthopedics.

[Elastofibroma in the scapular region. A case report and review of the literature]

PURPOSE OF THE STUDY

We report a case of elastofibroma and have collected 280 cases in the literature.

MATERIAL AND METHODS

A 56 year-old man presented with a right subscapular mass. The patient was asymptomatic but he reported a "clicking"sensation associated with mobilization of the shoulder. Physical examination revealed a round mass clearly demonstrated with forward elevation of the arm. The MRI scan showed a heterogeneous soft tissue composed of inhomogeneous density with areas of more intense signal suggesting adipose tissue. The tumor was surgically excised and the diagnosis of elastofibroma was established by histopathologic examination.

RESULTS

Six months after removal of the mass, there were no functional complications.

DISCUSSION

Elastofibromas usually occur in active patients generally older than 55 years of age. They are typically located in the right subscapular region. The tumor remains asymptomatic in more than 50 percent of cases. 25 percent of the patients may report a simple discomfort sometimes with a "clicking" or "catching" sensation associated with mobilization of the arm. Pain is present in less than 10 percent of cases. Physical examination may reveal a rubbery, asymptomatic mass located in the subscapular region and barely noticable when the arm lies again the chest. Plain radiographs and preoperative laboratory data were unremarkable. CT scan or MRI scan may show an heterogeneous fibrous mass of intermediate density with entrapped signals of higher intensity. However, a definitive diagnosis requires a biopsy showing the distinctive feature of elastofibroma: elastic fibers in a collagenized fibrous tissue with entrapped adipose tissue. Pathogenesis of elastofibromas may result from the friction of the scapula against the thorax thus generating tumor growth.

CONCLUSION

Complete surgical excision in symptomatic patients is considered to be the treatment of choice. However, once the diagnosis of elastofibroma has been established, excision of lesions smaller than 5 cm can be avoided in asymptomatic patients.

Selective killing of osteosarcoma cells in culture after retroviral mediated gene transfer of a herpes simplex thymidine kinase suicide gene

As conventional therapy of osteosarcoma is aggressive and its success relatively poor, notably in cases relapse, we investigated the therapeutic effect of retroviral herpes simplex thymidine kinase (HSV1-TK) gene transfer into a human osteosarcoma cell line. Transfected target cells are sensitive to ganciclovir (GCV) (IC50 0.1 microM), and a potent bystander effect, by which cell death can be induced in HSV1-TK negative dividing cells located in the vicinity of HSV1-TK positive ones, is demonstrated. This is significant for clinical applications as no available gene transfer method can achieve 100% transduction to target cells.

Treatment of experimental osteosarcoma tumors in rat by herpes simplex thymidine kinase gene transfer and ganciclovir

Previous results have demonstrated the efficiency of Herpes simplex type 1 thymidine kinase (HSV1-TK) retroviral gene transfer and ganciclovir (GCV) treatment of a human osteosarcoma cell line resulting in the death of the cell population and a proximal bystander effect; therefore, we investigated gene therapy on an in vivo osteosarcoma rat model. For in vivo experiments, small fragments of tumor were grafted onto rats in a paratibial position. Seven days after the graft, packaging cells (psi CRIP-TK and psi CRIP-LLZ) were inoculated into tumor mass, followed by GCV administration. In vivo results showed the efficiency of this system that allowed the reduction of the tumor mass and prevented lung metastasis appearance, which represents the normal evolution. This type of treatment seems promising for rapidly proliferating tumors such as osteosarcoma; the lower IC50 makes this system particularly attractive as clinically doses may be of low magnitude to prevent secondary effects in patients.

[Use of a Russel-Taylor nail for stabilizing fractures of the femur. Apropos of 57 fractures with 30 computed tomographies of the rotation]

PURPOSE OF THE STUDY

A clinical and radiographical study with CT in 30 cases was undertaken in femoral fractures fixed with Russel-Taylor intramedullary nail.

MATERIAL AND METHODS

In this retrospective study of 57 femoral fractures (mean follow-up 22 months), all fractures were analysed according to the classification of Wiss and Winquist-Hansen-Clawson. Fixation was performed with Russel-Taylor intramedullary mailing. Fifty fractures were classified as unstable due to the type of fracture and for its localization. Analysis of the clinical and radiographical results was performed immediately postoperatively and later by CT (30 cases).

RESULTS

Clinical results showed seven cases of hip pain and limited walking capability; twenty with decreased hip mobility; twenty-one with functional impairment of the knee with limited flexion (11 cases) and/or knee sprain (15 cases). Radiographical results showed sixteen cases of leg shortening inferior to 1 cm, three between 1 and 2 cm, and one exceeded 2 cm; nine with varus angulation of 5 degrees, one with valgus angulation of 5 degrees, and seven with external rotation exceeding 10 degrees, five with internal rotation exceeding 10 degrees. Results were determined according to Thorensen's criteria.

DISCUSSION

The use of Russel-Taylor intramedullary nail for the management of complex femoral fractures is discussed. Rotational deformities appeared related to the quality of reduction during surgery. Because of the stiffness of this type of nail, a smaller diameter can be used. Result analysis demonstrates that static nailing should probably be used more frequently in unstable femoral fractures.

Development of in vitro biocompatibility assays for surgical material

This work reports the development of a test to evaluate the biologic effects of implant material used in orthopaedics and traumatology based on the examination of inflammation and allergic reactions at the cellular level. The variation in arachidonic acid metabolite production by murine peritoneal macrophage cultures was studied using different powders of implant material. Macrophage activation by zymosan served as a control. Mouse peritoneal macrophages were labeled with 14C-arachidonic acid, and the synthesis of cyclooxygenase products (6-keto-prostaglandin F1 alpha; prostaglandins F2 alpha, E2, D2; and thromboxane B2) and lipoxygenase products (hydroxyeicosatetraenoic acids) was analyzed and quantified by chromatography. Results obtained through these assays support the reported clinical data that chrome and nickel increase the production of hydroxyeicosatetraenoic acids by mouse peritoneal macrophages. HXPATRI, titan oxide, and monoclinic zircon also increase the production of hydroxyeicosatetraenoic acids in contrast to other powders tested (alumina, HXPBL, chrome cobalt alloy, stainless steel 316L, titan, quadratic zircon), which have little effect on the production of arachidonic acid metabolites by the lipoxygenase pathway. It is concluded that determination of arachidonic acid metabolite production by murine peritoneal macrophage cultures is appropriate for evaluating implant material.

[Recent fractures of the base of the 1st metacarpal bone. A study of a series of 138 cases]

Fractures on the base of the first metacarpal are uncommon lesions, affecting young subjects and have major social repercussions (an average of 3.5 months off work). The authors have analysed the clinical and radiological results of a series of 138 recent fractures of the base of the first metacarpal with a mean follow-up of 7 years (12 month-14 years). They used a classification into 5 types (Bennett's with a large fragment = 22%, Bennett's with a small fragment = 20%, Rolando = 15%, extraarticular fractures = 36%, Comminuted fractures = 6%) which are easy to recognize on standard x-rays, or preferably on Kapandji views, allowing a standardized therapeutic approach. 70% of patients were younger than 40 and in one half of cases the causal accident was a motor vehicle accident. 12% of fractures were open and 45% were associated with other traumatic lesions. In this series, 35% of cases were treated orthopedically, 57% according to Iselin's technique, 5% by direct osteosynthesis and 3% by external fixation with a mean immobilization of 40 days. A number of clinical and radiological criteria were studied in the 88 patients reviewed. A 100-point grading system was established and, independent of the type of treatment, the authors obtained 61% of very good results, 23% of good results, 12% of moderate results, 2% of poor results and 2% of very poor results. Articular lesions constituted a factor of severity and failure to respect opening of the commissure appeared to be more pejorative than a small imperfection of reduction. The authors noted that simple treatment according to Iselin's technique still has many indications despite progress in miniaturized osteosynthesis.

Intradiscal injection of triamcinolone hexacetonide for acute, subacute, and chronic sciatica. Results at 3 months an open-prospectus study of 30 cases and review of the literature

The authors report an open study of 30 cases of intradiscal injection of triamcinolone hexacetonide in the treatment of sciatica. The patients were monitored at months 1 and 3. The results were judged to be good in 36.6% of the cases, moderate in 36.6% and poor in 26.7% of the cases. Two adverse effects were reported: 1 case of reversible urinary retention and 1 case of deficiency of the dorsiflexor muscles of the foot. The good results reported in previous series were only found in this study when the indications were restricted to certain favourable prognostic factors: duration of sciatica less than 6 months and CAT-scan appearance of discal hernia. This technique has the advantage of being simple, economical and nonallergic. On the basis of the encouraging results of the initial series, this technique should be considered as an interesting therapeutic alternative in sciatica. Larger series and double-blind studies, however, are necessary to confirm the initial results.

Study of the experimental biomechanics of tendon repair with immediate active mobilization

The authors present a biomechanical study of tendon behavior after primary suturing and early active mobilization. In this animal study (23 specimens), three types of sutures are compared using 2 biomechanical parameters: the load at rupture (R), and Young's modulus of elasticity (E). The authors show that early mobilization does not compromise the final strength of a tendon. Moreover, early mobilization confers the biomechanical characteristics of resistance and elasticity more closely akin to those of the normal tendon. Pathoanatomical examinations confirm the fibroelastic reaction of cicatrization and the mechanical role of mobilization in the orientation of newly formed tendon fibers.