Effect of callus development on the deformation of external fixation frames.

PURPOSE: We designed a sensor that measures the bending moments at the articulations and the torque of the rod of a Hoffmann II® external fixation. We considered the effect of the callus formation in the stabilisation of a "fracture-fixation system." METHODS: Four Hoffmann II® frame configurations were mechanically tested. Two carbon fibre tubes represent the bone fragments (length 180 mm, outer diameter 25 mm, inner diameter 19 mm). The callus is represented by the interposition of springs of different rigidity (10-405 N/mm) in the fracture gap between the tubes. RESULTS: The deformation of the frame is in inverse proportion to the stiffness of the callus; the slope of the curve drops rapidly during early development of the callus, to reach a plateau after some 50 % of recovery of the normal mechanical characteristics of the bone. This simulation supports the theoretical approach, i.e. the external frame resists larger stresses at the start of the fracture healing. Over a callus stiffness of some 200 N/mm the pattern of the curves remains similar, regardless of the frame configuration. CONCLUSION: An optimisation of the frame is possible, adapted to the actual mechanical situation of the callus. A monitoring system is deemed reliable after making sure that the elementary components behave the same way in the clinical condition as in the laboratory. In an experimental set up we confirmed its reliability in a clinical-like situation.

Results of open arthrolysis for elbow stiffness. A series of 22 cases.

Severe posttraumatic elbow stiffness represents a significant invalidity. Between 1990 and 2005 two surgeons performed open elbow arthrolysis in 30 adult patients (6 women, 24 men, mean age 30.8 years). All cases resulted from severe initial trauma, which had occurred on average 15.5 months previously. Four patients had extrinsic and 18 had mixed contractures; 13 had heterotopic ossifications. Operative complications included two peroperative joint instabilities and 3 transient nerve palsies. Seven elbows were remobilized under anaesthesia, one month after the arthrolysis. Twenty-two patients could be reviewed, on average 56 months after the arthrolysis. Seventy seven percent of the patients were satisfied. At final follow-up, the average arc of flexion-extension was 95 degrees +/- 15 degrees (average flexion 120 degrees +/- 13 degrees, average flexion contracture 31 degrees +/- 6 degrees), with a mean improvement of 51 degrees relative to the preoperative range (p < 0.001). The average arc of forearm rotation at final follow-up was 151 degrees +/- 23 degrees, with a mean improvement of 41 degrees (p < 0.05). No patient suffered persistent weakness or instability. The average VAS was 5/10, the average MEPI score 76, with 6 excellent, 6 good, 6 fair and 4 poor results, mainly because of persisting pain. The average DASH score was 31.6 and the average SF-36 was 66. Significant correlations were observed between VAS and DASH, MEPI and SF-36. This series demonstrates that open arthrolysis may restore acceptable elbow motion in young active patients presenting with elbow stiffness following major trauma. However, full restoration of motion is rare; only 18% of the patients regained the functional arcs of motion reported by Morrey, but the majority were satisfied, given their preoperative degree of elbow stiffness. The ultimate result from both the patient's and the surgeon's perspectives is strongly dependent on persisting pain, which was frequent in this series and influenced the DASH, MEPI and the SF-36 scores. Arthrolysis did not address the issue, if pain was the chief complaint.

Histopathology of aseptic necrosis of the femoral head in sickle cell disease.

This study compares the histopathology of bone biopsies from patients suffering from sickle cell anaemia (homozygote SS) to heterozygote patients (SA) and homozygotes with aseptic osteonecrosis (AA). The sensitivity to bacterial infection of sickle cell patients raises the question of the aetiology of sepsis in the onset of the necrosis. To our knowledge this study is the first to analyse the histopathology of osteonecrosis of the femoral head, at its early stages, in sickle cell anaemia. At the University Hospital of Pointe-à-Pitre, from 1994 to 2007, 38 bone biopsies were obtained from adult patients with avascular necrosis of the femoral head at the time of a core decompression procedure (SS, SC: 27; AS: 5; AA: 6). The histology of the biopsies confirmed the necrosis; all bacteriological cultures were negative. Patients displaying one S gene (SS, SC, AS) compared to homozygote subjects (AA) showed a significant increase of a nonspecific inflammatory granulomatosis (p = 0.003). No relationship was observed between the radiological stages and the histology whatever the genotype (p = 0.1). Inflammatory histopathology without sepsis or advanced alteration characterises the early stages of sickle cell necrosis. This inflammatory process is absent in idiopathic avascular necrosis.

Shoulder arthrodesis using combined internal and external fixation: a review of 9 cases.

A technique of shoulder arthrodesis is presented. Fixation of the arthrodesis combines scapulohumeral half-frame Hoffmann external fixation and internal fixation using a cancellous screw. Cancellous bone autografts are packed at the site of arthrodesis. The functional results of nine cases are presented.

Mini external fixation for hand fractures and dislocations: The current state of the art.

External fixation devices for the hand provide a versatile approach to various hand injuries. Some fractures and dislocations urge the use of an external minifixation; in other fractures, external minifixation must be seen as an alternative or companion to other methods of hand stabilization. MiniFix is useful to maintain or restore hand function and hand anatomy.

Surgical treatment of ankle fractures by pneumatic stapling: clinical experience and review of the literature.

Between June 1987 and December 2002, 237 cases of malleolar fractures were treated at Erasme Hospital using pneumatic stapling, alone or combined with another type of fixation. This retrospective study addresses 176 well-documented cases. The mean follow-up period was 36 months. The results indicate that pneumatic stapling is an effective technique with a very low rate of failure. Comminuted fractures are not a contraindication.

Functional and outcome evaluation of the hand and wrist.

The first evaluation of the upper extremity and hand, performed by the surgeon at the outpatient clinic, is fundamental to understanding the patient's problem, determining the best treatment options, and, in the case of a surgical indication, assessing the preoperative status. In addition to recording the patient's symptoms and complaints, the surgeon evaluates anatomic integrity, stability, mobility, trophicity, strength, and sensibility. In many patients, especially patients with severe handicaps or those who anticipate long delays in rehabilitation, in litigation problems, or as part of prospective clinical research, this classic evaluation is not sufficient. The authors recommend that to accommodate these patients, a laboratory of functional evaluation of the hand should be established. The evaluation, performed by independent reviewers, ideally includes techniques allowing objective measurements of kinematics, strength, sensibility, and global hand function and dexterity. Pain assessment using the VAS is indispensable. The results may be presented as scores based on to the patient's problem. The researchers should analyze precisely how the scores were constructed. Questionnaires are part of the evaluation armamentarium. As with other tools, questionnaires allow us to understand better what our patients experience. They do not replace physical examination. Questionnaires also could be used for routine screening in a general upper limb practice, even before the patient sees the hand surgeon. The choice of the questionnaire is important; the reviewer should make sure that the patient understands all questions, that the questions are not redundant, and that they do apply to the patient. Generic health status instruments such as the SF-36 allow comparison across a variety of health problems, including mental and physical conditions, but are not sensitive to upper extremity disability. The DASH questionnaire seems a better choice, allowing a standardized outcome evaluation. Dedicated questionnaires have been developed for specific conditions (eg, carpal tunnel syndrome). As discussed by Amadio, questionnaires are easier to perform than physical testing, can be self-administered, and require no special equipment, saving the cost of an examiner, avoiding the complexities of scheduling a follow-up examination, and eliminating the possibility of observer bias. The patient is less likely to offer polite but incorrect responses. Questionnaires are especially useful when patient's perceptions are important to assess. Questionnaires also could be used in longitudinal studies to assess improvement or aggravation. The use of questionnaires is therefore especially indicated in studies involving a large number of patients, when observer bias and costs are concerns, and when the main outcome measurements are satisfaction, symptoms, or functional status. Amadio has pointed out that questionnaires are not the best tool to measure anatomic or physiologic impairments.