Fabian Moungondo

Radiocapitellar joint contacts after bipolar radial head arthroplasty.

PURPOSE The purpose of this study was to determine radiocapitellar contacts before and after radial head replacement, using the bipolar design of Judet. METHODS Joint contacts were measured by moulding the joint surfaces of 6 fresh-frozen cadaveric specimens, in various positions of elbow flexion and forearm rotation. RESULTS Expressed as function of the radial cup, contact areas averaged 44% in the normal elbow, decreasing with flexion and increasing with supination (P < .05). After prosthetic implantation, contact areas averaged 33% and remained quite similar, irrespective of elbow position. Subluxation of the prosthetic head over the lateral margin of the trochlea was seen systematically with supination. CONCLUSIONS Because of intraprosthetic mobility, contact areas were not dependant on elbow position. This adaptability, however, also led to abnormal positioning of the prosthetic radial head with supination, subluxing over the trochlea lateral margin.

Prognostic factors in the treatment of carpal scaphoid non-unions

In this literature review, the authors analyse the prognostic factors in the curative treatment of scaphoid non-unions. The main negative prognostic factors are smoking, the time elapsed since the fracture, and avascular necrosis of the proximal fragment. If the latter is present, the revascularization by a pedicle or microsurgical bone autograft is probably the treatment of choice. In non-unions without evidence of osteonecrosis, vascularized bone grafts are probably not superior to conventional bone grafts, which can presently be performed under arthroscopic control, with minimal morbidity.

Dislocation of the elbow with ipsilateral forearm fracture. Six particular cases.

Elbow dislocation associated with ipsilateral radial shaft fracture is an infrequent injury (nine cases reported in the literature). We present six new cases observed between 2006 and 2012, with an average age of 31 years and a mean follow-up of 18 months. The forearm fracture and ipsilateral dislocation of the elbow were probably caused by forearm hypersupination with extension of the elbow. The dislocation was reduced by manipulation before open reduction and osteosynthesis of the forearm fracture. Four elbows were stable after reduction; two markedly unstable elbows necessitated temporary humero-ulnar external fixation; one case needed a ligamentoplasty several months later. Despite the complexity of the traumatic lesion, the clinical and radiological outcomes were acceptable.

The effect of humerus diaphyseal shortening on brachial plexus tension: a cadaver study.

PURPOSE To assess the extent to which diaphyseal shortening of the humerus can allow direct suture in case of rupture or transection injuries of the brachial plexus. METHODS The use of 3 fresh cadaver specimens allowed for the study of 6 brachial plexuses. Distance measurements were made between reference points placed on the clavicle and on different parts of the plexus. Those measurements were repeated after shortening the humerus by 2, 4, and 6 cm. RESULTS None of the dissected plexuses had classic anatomy. A humeral shortening of 6 cm allowed for a statistically significant reduction of length between the supraclavicular part of the plexus and the terminal branches, which did not exceed 17 mm on average. The difference of length was much greater for the specimen in which the musculocutaneous nerve did not pierce the coracobrachialis muscle proximally. CONCLUSIONS In clinical situations, nerve defects are usually larger than the gain observed when doing a 6-cm humeral shortening. Moreover, this procedure implies a large dissection, a functional loss of certain muscles, and a risk of humeral nonunion. CLINICAL RELEVANCE In the absence of extensive nerve dissection, the observed change of length is insufficient in the most brachial plexus disruptions to allow for a direct suture instead of long nerve grafts.

A New Clinical Sign of Lumbrical Plus Finger

Paradoxical finger extension is the classical clinical presentation of the lumbrical plus syndrome. We report a new additional sign, increased metacarpophalangeal flexion of the involved finger when the patient tries to make a fist. Three cases of lumbrical tightness are discussed, illustrating this new sign in 3 different clinical settings. The new sign was present in all 3 cases. Lumbrical tenotomy corrected the paradoxical interphalangeal extension and partly the increased metacarpophalangeal flexion. The lumbrical tendon has a relatively high moment arm relative to the metacarpophalangeal joint, which could explain the basis of this clinical sign. This new physical examination sign may help in diagnosing the lumbrical plus syndrome, a subtle complication of flexor digitorum profundus lesions that is not easily diagnosed but which is easily addressed.

Lunarectomy and Progressive Capitate Lengthening (Modified Graner–Wilhelm Procedure)

The Graner–Wilhelm procedure, indicated in selected stage III Kienbock’s cases with preserved hyaline cartilage at the distal radius lunate fossa and capitate head (Bain–Begg Kienbock’s grade 0 or 1), consists of resection of the necrotic lunate, transverse osteotomy of the distal corpus of the capitate, implantation of an external minifixator, followed—after 7–10 days—by progressive lengthening of the capitate until the carpal height is restored. Bone healing under distraction osteogenesis is relatively quick. After rehabilitation the patient regains acceptable wrist joint motion and strength. Contrary to what is observed after first carpal row resection, no degenerative osteo-arthrosis seems to affect the radio-capitate joint.