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J Grimberg

Publications and source records attributed to J Grimberg.

15 recordsLinked to original sources
PubMed2006

[Arthro-C-scan analysis of rotator cuff tears healing after arthroscopic repair: analysis of predictive factors in a consecutive series of 167 arthroscopic repairs].

PURPOSE OF THE STUDY: Arthroscopic repair of rotator cuff tears is a well described technique with good clinical results. The purpose of this work was to use the arthro-CT-scan to evaluate tendon healing after arthroscopic repair and search for epidemiological, anatomic and technical factors predictive of tendon healing. MATERIAL AND METHOD: This prospective consecutive series included 167 non-randomized shoulders. All patients underwent a preoperative assessment using the crude Constant score and a standard x-ray protocol to evaluate cuff status. Cuff repairs were all performed arthroscopically. The crude Constant score was used to follow patients. A control arthroscan was obtained in 148 patients. RESULTS: Mean patient age was 59 years, 46% men and 77% dominant side. Mean duration of symptoms before repair was nine months. The tears resulted from trauma in 28%, including 9% occupational accidents. The preoperative mean crude Constant score was 52.4 (range 15-77). An isolated tear of the supraspinatus was observed in 68%. Frontal retraction of the supraspinatus was distal in 74%. In 29 cases, reduction was difficult. The quality of the tendon was considered normal in 56 cases and non-anatomic repair was necessary in six. At last follow-up (19 months on average) the mean crude Constant score was 80 (range 49-95). Arthro-CT-scan was performed to control healing in 148 patients and revealed anatomic healing in 69, defective healing in 27, and repeated tears in 52 shoulders. Factors predictive of healing were: tear less than six months old, sedentary occupational activity, non-dominant side, young patient, female gender, isolated small non-retracted tear of the supraspinatus, normal appearance of an easily reduced tendon, and good bone quality. DISCUSSION: Time from tear to repair was long in this series. Tendon and muscle changes occurring after the injury could explain in part the healing failures. CONCLUSION: But this study confirmed good functional and anatomic results given by arthroscopic repair of rotator cuff tears.

Accidents, Occupational↗
PubMed2005

Influence of glenohumeral mismatch on bone strains and implant displacements in implanted glenoïds. An in vitro experimental study on cadaveric scapulae.

In shoulder arthroplasty, there is no consensus about the ideal mismatch between a prosthetic humeral head and a glenoïd component. Thus, investigations into mismatch effects from a biomechanical point of view can be useful. The aim of this in vitro study was to help us understand mismatch influence on bone strains, translational forces in the joint and implant/bone displacements in implanted scapulae. Five fresh cadaveric scapulae were implanted with a cemented keeled polyethylene implant. The lower part of the scapulae was embedded and the loadings were carried out using five metallic spheres simulating mismatches of 0, 2, 4, 5 and 6 mm. Loadings included a constant compressive preload of 392N and an anterior, posterior, inferior and superior translation of 2.5 mm. We measured the transversal force necessary to produce the imposed translation, the strains at six locations around the peripheral cortex of the glenoïd using strain gages and the relative implant/bone displacements using CCD cameras. Generally, the increase of mismatch reduced the translational forces, the strains around the glenoïd and, except for the anterior loading, the relative implant/bone displacements. Few and even no significant differences were observed when the mismatch varied from 0 to 2 mm; the number of significant differences increased when the mismatch varied from 0 to 4mm and from 0 to 5 mm; the results obtained for a 0-6 mm variation in mismatch were comparable to those obtained for a 0-5 mm variation. This study underlines that the mismatch has a significant effect on bone strains, relative implant/bone displacements and induced translational forces when a compressive preload and imposed translations were applied on implanted scapulae.

Aged↗
PubMed2005

A 3D finite element model of an implanted scapula: importance of a multiparametric validation using experimental data.

In order to help to understand the loosening phenomenon around glenoïd prostheses, a 3D finite element model of a previously tested implanted scapula has been developed. The construction of the model was done using CT scans of the tested scapula. Different bone material properties were tested and shell elements or 8 nodes hexaedric elements were used to model the cortical bone. Surface contact elements were introduced on one hand between the bone and the lower part of the plate of the implant, and on the other, between the loading metallic ball and the upper surface of the implant. The results of the model were compared with those issued from in vitro experiments carried out on the same scapula. The evaluation of the model was done for nine cases of loading of 500 N distributed on the implant, in terms of strains (principal strains of six spots around peripheral cortex of the glenoïd) and displacement of four points positioned on the implant. The best configuration of the model presented here, fits with experiments for most of the strains (difference lower than 150microdef) but it seems to be still too stiff (mainly in the lower part). Nevertheless, we want, in this paper, to underline the importance of doing a multiparametric validation for such a model. Indeed, some models can give correct results for one case of loading but bad results for another kind of loading, some others can give good results for one kind of compared parameters (like strains for instance) but bad results for the other one (like displacements).

Aged↗
PubMed2005

[Not Available].

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Journal Article↗
PubMed2005

Accuracy of CT arthrography in the assessment of tears of the rotator cuff.

CT arthrography and arthroscopy were used to assess tears of the rotator cuff in 259 shoulders. Tear size was determined in the frontal and sagittal planes according to the classification of the French Arthroscopy Society. CT arthrography had a sensitivity of 99% and a specificity of 100% for the diagnosis of tears of supraspinatus. For infraspinatus these figures were 97.44% and 99.52%, respectively and, for subscapularis, 64.71% and 98.17%. For lesions of the long head of the biceps, the sensitivity was 45.76% and the specificity was 99.57%. Our study showed an excellent correlation between CT arthrography and arthroscopy when assessing the extent of a rotator cuff tear. CT arthrography should, therefore, be an indispensable part of pre-operative assessment. It allows determination of whether a tear is reparable (retraction of the tendon and fatty degeneration of the corresponding muscle) and whether this is possible by arthroscopy (degree of tendon retraction and extension to subscapularis).

Adult↗
PubMed2002

In vitro biomechanical analysis of glenoïds before and after implantation of prosthetic components.

Biomechanical investigations are yet necessary to better understand the origin of the glenoïd loosening which is the main reason for revision surgery. The aim of this study was to analyse the behaviour of cadaveric glenoïds before and after implantation of glenoïd prostheses. For that, we developed a new experimental protocol allowing measurement of bone strains and implants displacements under various loading cases. Ten pairs of fresh cadaveric scapulae were tested. Two kinds of loads were applied on the intact glenoïd: physiological loads corresponding to a 0-180 degrees abduction and anteflexion movements, and 500N loads. The glenoïds were then implanted with a keeled or pegged cemented polyethylene implant. The same previous 500N loads were then applied on the implanted glenoïds. Strains were measured using six strain gages placed on precise points around the peripheral cortex of the glenoïd. Displacements of implants under loading were measured using two CCD cameras. Maximum strains were obtained between 60 degrees and 120 degrees of abduction or anteflexion. They were located at the anterior and antero-superior parts of the glenoïd during abduction and at the posterior and postero-superior parts during anteflexion. Implantation of a prosthetic component generally seemed to increase strains, but tensile strains were decreased at the postero-inferior part with the antero-inferior loading point.Some differences were observed between the implants, but they have to be confirmed by further experiments. The great number of data obtained for intact scapulae could be used for a better understanding of glenoïd behaviour and for validation of finite element models.

Aged↗
PubMed2001

[Infection of a total knee prosthesis revealed by an abscess of the posterior leg compartment. A case report].

We report a case of infection of a non-cemented total knee prosthesis that led to abscess formation in the posterior compartment of the leg. This case illustrates the deleterious effect of screws used to fix the non-cemented articular surface of the tibia. Infection, like osteolysis due to polyethylene granuloma, can develop along the screw tract and reach the posterior compartment, especially when the screw protrudes through the posterior cortical of the tibia. Diffusion of an intra-articular event into the posterior compartment should be suspected in patients with a total knee prosthesis who experience calf pain.

Abscess↗
PubMed1996

[A new method of osteosynthesis in proximal humeral fractures: a new internal fixation device. Apropos of 17 cases followed over more than 2 years].

PURPOSE OF THE STUDY: The authors describe a new internal fixation device, and report on 17 proximal humeral fractures managed with this technique. MATERIAL AND METHODS: The fracture patterns, using Neer's classification were: 9 displaced three-part fractures, 4 displaced four-part fractures and 4 interior fracture dislocations (mean age of the patients: 70 years). The device is a two-part titanium device. The humeral component has a long vertical stem cemented in the humeral shaft; and a short proximal portion set at an angle of 135 degrees on the stem, with a neck and a Morse taper cone. The other part is a crown-shaped stapple, whose base is a perforated disk with a central Morse taper socket. The rim of the crown has five prongs which, together with the central socket, are impacted in the cancellous bone of the humeral head. The taper of the humeral component is inserted into the central socket of the stapple to provide fracture fixation. Tuberosities are reattached to the shaft with non absorbable sutures. RESULTS: Mean follow-up was 29 months. The global ratings were as follows: 4 excellent results, 6 good results, 4 fair results, 3 poor results. Mean active forward flexion: 100 degrees, and mean active external rotation 22 degrees. After exclusion of the 4 fracture-dislocations, the global rating became: 4 excellent results, 5 good results, 3 fair results, 1 poor result. Mean active forward flexion: 110 degrees and mean active external rotation: 31.5 degrees. There were no case of avascular necrosis in 13 patients. Complications requiring surgery occurred in one case: an upper protrusion of the stapple which required replacement of the stapple by a prosthetic humeral head. Other complications included: 2 asymptomatic partial protrusions of the stapple, 2 complete and two partial avascular necrosis in fracture-dislocations. DISCUSSION: Except for the fracture-dislocations our device confers several major benefits. The humeral head is preserved. Typical problems associated with joint replacement (dislocations, loosening, glenoid degeneration) are avoided. Humeral head conservation enhances healing of the tuberosities. Fixation could always be obtained, regardless of the complexity of the fracture pattern. An hemiarthroplasty (e.g. in case of avascular necrosis) is possible by the modular design of the device.

Adult↗
PubMedDate not supplied

A new internal fixation technique for fractures of the proximal humerus--the Bilboquet device: a report on 26 cases.

We describe a novel internal fixation device and report on 26 patients (mean age, 70 years) whose proximal humeral fractures were managed with this technique. The 2-part titanium implant consists of a circular staple impacted into the humeral head cancellous bone and a spigoted diaphyseal stem that inserts into the staple "cup." Of the 26 cases reviewed, 16 had 3-part fractures and 10 had 4-part fractures. Mean follow-up was 25.9 months. In the 16 3-part fractures, the mean active forward elevation was 114 degrees and the results were as follows: excellent, 7; good, 5; fair, 3; poor, 1. In the 10 4-part fracture patients, the mean active forward elevation was 101 degrees and the results were as follows: excellent, 2; good, 4; fair, 3; poor, 1. There were 5 cases of avascular necrosis and 1 case of tuberosity nonunion. Only 2 cases needed conversion to hemiarthroplasty. The new technique should simplify the surgery of these fractures and reduce the need for arthroplasty.

Adult↗