In vivo kinematics of the first carpometacarpal joint after trapezectomy.

UNLABELLED: First carpometacarpal osteoarthitis is frequent and surgery may be necessary if medical treatment is not efficient. Trapeziometacarpal arthroplasty, trapeziometacarpal arthrodesis and trapezectomy may be proposed. These surgical solutions may modify the carpometacarpal kinematics of the thumb. However, no clinical tools are currently available to assess these modifications. The goal of our study is to assess the TM kinematics, with an optoelectronic system, in patients after trapezectomy. Ten women, average age 53 (range 45 to 67) underwent trapezectomy with ligamentoplasty for trapeziometacarpal osteoarthritis. An optoelectronic device (Polaris(®)) was used to analyse postoperative range-of-motion of the thumb. Splints were used in order to isolate the trapeziometacarpal joint and retroreflective markers were placed both on the splints and on the thumb. Mean flexion-extension, abduction-adduction, axial rotation and circumduction were calculated. RESULTS: The mean range-of-motion of trapeziometacarpal joint was 50 degrees for flexion-extension, 47 degrees for abduction-adduction and 11 degrees for axial rotation. The mean angle between rotation axes was 90 degrees and the mean distance d between the axes was 3 millimeters. Comparisons between patients and healthy subjects showed no significant differences in flexion-extension, abduction-adduction and axial rotation. Circumduction in patients was reduced compared to healthy subjects. No significant differences were noted between the operated side and the contralateral side. DISCUSSION AND CONCLUSION: Our study showed that this protocol can be used in the postoperative follow-up of patients after trapezectomy. We did not find any significant differences compared to the contralateral side. However, circumduction after trapezectomy was reduced compared to healthy subjects.

Normal range-of-motion of trapeziometacarpal joint.

PURPOSE: The range-of-motion of the trapeziometacarpal joint is difficult to assess clinically. The purpose of our study was to constitute a range-of-motion database from normal active trapeziometacarpal joints. MATERIAL AND METHODS: Two hundred hands from 101 healthy subjects (50 female and 51 male) with a mean age of 23.1 years (range: 22 to 35 years) have been evaluated. An optoelectronic device (Polaris) was used to analyse the thumbs range-of-motion. Splints were fitted so as to isolate the trapeziometacarpal joint and retroreflective markers were placed both on the splints and on the thumb. After active flexion-extension, abduction-adduction, axial rotation and circumduction, the different range-of-motion parameters were calculated. RESULTS: The mean range-of-motion of the trapeziometacarpal joint was 41 degrees for flexion-extension, 51 degrees for abduction-adduction and 21 degrees for axial rotation. Comparisons between female and male subjects showed significant differences concerning flexion-extension, abduction-adduction axial rotation and circumduction. No significant differences were noted between right and left hands except for the abduction-adduction movement. DISCUSSION AND CONCLUSION: One hundred and one healthy subjects were analysed for the development of a database of normal active range-of-motion parameters of the trapeziometacarpal joint, with an in vivo protocol. This database should allow comparing the range-of-motion of patients with osteoarthritic trapeziometacarpal joint and assessing surgical outcome.

Role of deltoid and passives elements in stabilization during abduction motion (0 degrees-40 degrees): an ex vivo study.

The deltoid and the passive elements of the glenohumeral joint play a role during abduction of the upper limb. However, there is a lack of quantification of their respective role. The aim of the present study was to describe the influence of the deltoid and the passive elements during kinematics experiments in abduction (0 degrees-40 degrees) of unconstrained humerus. Six fresh-frozen anatomical specimens were considered. Bi-planar X-rays were obtained using the EOS imaging system (Biospace Med, Paris, France). Then a horizontal traction at constant speed was applied to the "acromion and clavicle block", using an universal testing machine and specific device, and the humerus kinematics was recorded using an optoelectronic system (Polaris, NDI, Canada). For each anatomical specimen the protocol included two types of tests: intact capsule and perforated capsule. For a displacement of 28 mm of the acromio-clavicular set, the amplitudes of "abduction" rotation vary between 26 degrees and 41 degrees for the "intact capsule" configuration and between 27 degrees and 40.5 degrees for injured capsule configuration. For the same displacement the translation according to Y of the humeral head changes between 1 and 5.5 mm for intact capsule configuration and between -0.5 and 5.5 mm for injured capsule configuration. During the abduction (0 degrees-40 degrees) motion this study suggests that the humeral head is stabilized by the deltoid, the labrum, tendons of the rotators cuff and to a lesser level by the glenoid.

3D kinematics of the glenohumeral joint during abduction motion: an ex vivo study.

The clinical tolerance of rotator cuff tears is extremely variable, so the question is, what is the role of the deltoid in the shoulder stability? First of all, ex vivo experiments are necessary to analyse its effect. The aims of this study were: (1) to propose a testing protocol to measure the glenohumeral joint kinematics during the abduction motion by pulling on the deltoid without constraining the humerus and (2) to evaluate the repeatability of the 3D measurements. Six fresh-frozen anatomic specimens were tested. The kinematics follow-up of the osseous parts was carried out using an optoelectronic system (Polaris((R)), NDI, Canada). The abduction motion is realized by the pulling on anterior and medium fibers of the deltoid. For a 25 mm displacement, the range of motion: for the abduction was 24 degrees to 30.5 degrees , for the flexion was 1.5 degrees to -30.5 degrees (extension), for the medio-lateral rotation was 12 degrees (lateral rotation) to -5 degrees (medial rotation). For a displacement of the whole acromion-clavicle between 0 and 25 mm, the three humeral head translations were less than 5 mm. The three rotations and three translations were (with SD 95%): abduction: 0.5 degrees , flexion: 1 degrees , medio-lateral rotation: 1.5 degrees , three translations: 0.5 mm. The results showed a very high repeatability of the values. Results suggest that the deltoid alone can realize a motion of lateral elevation with a good stability in the glenohumeral joint as shown by the slight translation motion of the head and the value reproducibility. The protocol can be used to validate a finite element model of the glenohumeral joint.