[Dynamic biomechanical study of a new osteosynthesis system for distal radius fractures]. / Etude biomécanique d'une nouvelle ostéosynthèse des fractures distales du radius.

The aim of this study was to evaluate the stability in compression of a new implant for fractures of the distal radius. Of all the displacements found with this fracture, shortening is the one most difficult to maintain by osteosynthesis. We tested the properties of a central-medullary steel nail 9 cm length, of diameter 5 mm, curvilinear, introduced at the radial styloid, combining proximal unicortical and distal bicortical locking. The biomechanical laboratory tests were carried out on 10 human radii taken from 5 male anatomical subjects of ages ranging from 48 to 88 years. A wedge-shaped defect in the metaphyseal zone was created to reproduce posterior shortening in these Pouteau-Colles' fractures. The same anatomical subject received the two types of osteosynthesis: an intramedullary nail and a styloid pinning. The force-displacement curves showed that intramedullary osteosynthesis with this interlocking nail is an assembly three times more resistant to compression than bi-styloid pinning. Stabilization of this fracture in porotic bone has to rely on distal screw purchase in the subchondral bone, which seems to us to be the only element able to resist compressive forces. This new implant should make it possible to restore and preserve the length of the radius whilst maintaining reduction in all three dimensions. Given its good biomechanical results, this nail constitutes a viable possibility for minimally invasive internal fixation of these fractures and warrants a clinical trial.

[Biomechanical evaluation of osteosynthesis with cannulated screws for Ponteau-Colles fractures in a bird model]. / Evaluation biomécanique de l'ostéosynthèse par vis canulées enfouies des fractures de Ponteau-Colles sur un modèle aviaire.

INTRODUCTION: The use of cannulated screw without protrusive head in Colles fractures could avoid some of the drawbacks of conventional pinning. In order to compare the mechanical resistance of Kirshner wires versus cannulated screws we designed a animal model of Colles fractures and tested three types of osteosynthesis: A: K-wires, B: Herbert cannulated screw, C: specific cannulated screws. METHOD: After creating a 10 mm defect in three sets of 10 fresh turkey tibia, 3 types of osteosynthesis were done and tested in compression with an Adamel Lhomargy machine: set A: K-wire fixation, set B: Herbert screws fixation and set C: specifics screws fixation. RESULTS: The compression strength needed for failure of the fixations were: for the K-wires (set A): 52 N +/- 17; for the Herbert screws (set B): 93 N +/- 39; for the specifics screws (set C): 160 N +/- 48; (p < 0.0001). DISCUSSION: The use of an animal model makes the experimentation easier and the sampling more homogeneous. In this model, resistance to compression of the cannulated screw was better than K-wires and the specific cannulated screw better than Herbert screw. Therefore clinical trial of osteosynthesis with cannulated screw in Colles fracture could be considered.

Use of the extensor retinaculum as a donor site for bone-ligament-bone grafts.

The recent introduction of bone-ligament-bone grafts for ligament reconstruction in hand surgery has led to a search for suitable graft donor sites. The extensor retinaculum had been suggested, but harvesting details were still lacking. We therefore studied the anatomy of the extensor retinaculum, with radiography and morphometric measurements. Ten cadaver wrists were dissected; the thick portion of the retinaculum and its insertions on the radius in the different extensor compartments were studied. The compartments were wire-marked, and AP radiographs taken of each specimen. The retinaculum spanning the first three compartments was removed with the bony ridges it inserted on, and the inter-ridge retinaculum length was measured. A comparison of our dissections with the radiographs showed that only the radial compartments 1, 2 and 3 had constant bony insertions on both ridges, making them suitable for bone-ligament-bone grafting. The mean compartment length was 11.7 mm (compartment 1), 17 mm (compartment 2) and 7.3 mm (compartment 3) respectively. Thus, the extensor retinaculum can be relied upon to provide bone-ligament-bone grafts from the first three compartments, for possible use in ligament reconstructions in the hand and wrist.

Thenar flap rehabilitated: a review of 20 cases.

The thenar flap is a satisfactory reconstruction technique for the treatment of extensive loss of the distal phalanx of the index and middle fingers. As we observed in this series of 20 patients, this flap is reliable and provides tissue that closely matches the missing finger pulp. Flap sensibility is good (average Weber of 6.5 mm). Transferring a distally based flap prevents proximal interphalangeal joint contracture and allows the surgeon to better reconstruct the outlines of the distal phalanx, thereby reducing the risk of a clawed nail. Finally, we did not observe major postoperative complications at the donor site.

[Reconstruction of digital pulp by pulp tissue transfer of the toe. Apropos of 15 cases]. / Reconstruction de la pulpe des doigts par transfert d'hémipulpe de gros orteil. A propos de 15 cas.

PURPOSE OF THE STUDY: The authors report their experience of digital pulp reconstruction by free toe pulp transfer. Fifteen patients were treated with the lateral great toe hemipulp. MATERIAL AND METHODS: 15 cases of post-traumatic finger tip reconstruction were reviewed including 9 thumbs, 5 index, 2 medius, and one ring finger. There were 6 emergency cases and 9 secondary reconstructions (7 after inconvenient spontaneous healing and 2 after groin flap coverage). RESULTS: We noted 2 partial necrosis, and 4 patients suffered from cold intolerance. The flap sensibility, according to the American Society for Hand Surgery criteria, was excellent in 1 case good in 6 cases, fair in 7 cases and bad in 1 case. The value of the mean two point discrimination test was 10 mm, the mean moving two points discrimination test equalled 9 mm. We had 1 excellent functional result, 6 good, 6 fair and 2 bad. The subjective evaluation found 12 patients satisfied and 3 disappointed. DISCUSSION: A wide range of procedures from spontaneous healing to thenar flap, neuro vascular flap or toe pulp transfer can be proposed to treat digital pulp loss. In the case of moderate thumb pulp avulsion and homodigital volar flap can be proposed; if microsurgery is contra-indicated, an hetero-digital flap from the index can be performed. When the other fingers are concerned, a homodigital flap can be proposed for moderate defects. For more important trauma, the thenar flap is convenient to cover the index and the medius pulp. Ring and little fingers can be treated by a reverse digital artery flap or by a cross finger flap. When a toe pulp transfer is indicated we recommend the lateral great toe hemipulp for the thumb and a second or third toe pulp transfer for the other fingers when digital vascular anastomosis are possible. The great toe hemipulp transfer represented a good indication for complete digital pulp loss reconstruction where the thumb is concerned. Performing this reconstruction during the acute phase may improve the management of those trauma by reducing the time needed for cicatrisation and the length of work inability.

[Cutaneous repairs of the hand]. / Les recouvrements cutanés de la main.

Immediate post traumatic skin defects can complicate osteo-articular, tendinous or neurovascular lesions of the hand. Aesthetic and functional repairs permit early rehabilitation. Having to choose between spontaneous heal and microvascular tissue transfer, many pediculated flaps are possible; the size of the wound and an exposure of bone or tendon are the determining factors. Spontaneous healing or skin grafting can be adequate in cases of a superficial wound. Deep wounds with a large exposure shall be covered with flap. A large range of flaps exists: the optimal flap permits adequate coverage with minimal sequellae.

[Free transfer in the emergency treatment of complex injuries of the arm. Apropos of 18 cases]. / Apport des transferts libres en urgence dans le traitement des traumatismes complexes du membre supérieur. A propos de 18 cas.

In 18 cases the authors used a free tissue transfer during the first 24 hours of the treatment of a complex trauma of the upper limb involving osteoarticular and neurovascular loss combined with loss of skin cover. The various flaps include: lateral arm flap (8 cases), latissimus dorsi flap (4 cases), toe to hand transfer (4 cases), radial forearm flap (2 cases). The series includes 2 failures salvaged without further sequelae by means of a groin flap. With regard to complex one-stage reconstructions, particularly those requiring replacement of bone, the outcome is improved if the selected method permits early mobilisation and complete cover. Free transfers are to be compared with loco-regional flaps which are more reliable but suffer limitations such as a small cutaneous element and, frequently, involvement of the pedicle in the mechanism of the trauma. For the severe cases in this series, only free tissue transfers provided the adequate, immediate cover required to save the traumatised limb.

[Severe injuries of the elbow: emergency coverage and transient revascularization. Apropos of 13 cases over a 3-year period]. / Les traumatismes délabrants du coude: couverture en urgence et revascularisation transitoire. A propos de 13 cas sur 3 ans.

Large open elbow fractures with extensive soft-tissue loss must be treated as an emergency. Vessels and nerves are often alvulsed. One stage reconstruction is very challenging. Ischemia of the distal part of the upper extremity is limited by a synthetic arterial shunt (SAS). After debridement, the authors install the SAS, then the complex procedure can begin. The authors purpose a new four-stage classification and prognostic factors. Debridement concerns crushed, devitalised soft and osteo-articular tissues. If it appears possible to salvage the hand and forearm with necessity of complex reconstructions (vessels, nerves, osteosynthesis, soft tissues) SAS is used. SAS was used 3 times on the group of large avulsions with ischemia (5 cases); it was quickly installed between the humeral and a distal artery and allowed section of the best distal artery for revascularisation. Seven external fixation devices allowed intra operative and post operative management of the wound. The coverage of these large, complex wounds was performed by the latissimus dorsi transposition flap (2 muscular and 5 musculo-cutaneous flaps). It should be considered the flap of choice. Local flaps, which include local skin transposition, muscle transposition or vascular axis, would be contra indicated in a wide zone of injury (the base of these local flaps are damaged by high energy trauma) or when distal ischemia is present because of arterial axis sacrifice. The dorsal decubitus position, the specific dissection of neurovascular pedicle proximally as far as the axillary artery, the muscular and cutaneous design can be used to cover anterior, posterior, internal and external parts of the elbow. Restoration of elbow function uses an innervated latissimus dorsi muscle (3 cases). If only coverage is wanted, this flap has significant advantages over local flaps and free transfer procedures when the recipient vessels are within the area of injury. Between the donor site and the recipient site, the muscular part of the latissimus dorsi flap is placed in an arm counterincision. It ensures closure of the elbow joint. Early progressive range of movement exercises can be performed.

[Use of an external brachial flap in the reconstruction of the upper limb. Apropos of 11 cases]. / Utilisation du lambeau brachial externe dans la reconstruction du membre supérieur. A propos de onze cas.

During the last three years, eleven lateral upper arm flaps were used in the reconstruction of skin defects of the upper limb. These flaps were applied: 7 times on the hand; 2 times on the fore-arm; 2 times on the elbow. Ten flaps had a free transfer, one was vascularised by the distal pedicle. In 4 cases we used an emergency free transfer in the treatment of a traumatic defect. In the other cases the flaps were used in the treatment of post-traumatic sequelae such as contracture and/or osteitis. The series contains 10 fascio-cutaneous flaps and 1 osteo-cutaneous flap. We had one failure with an emergency free flap, salvaged without further sequelae by means of a groin flap. The proximity of the donor site in an upper limb reconstruction makes the lateral upper arm flap a good alternative when a pedicle locoregional flap cannot be used due to a lesion of its pedicle in the mechanism of the trauma.

[Dorsal tenolysis and arthrolysis of the proximal interphalangeal joint. 19 cases]. / Téno-arthrolyse dorsale de l'interphalangienne proximale. A propos de dix-neuf cas.

18 patients suffering from PIP stiffness in extension were treated by dorsal teno-arthrolysis. PIP joint stiffness was due to 3 cases of fracture of P1, 2 cases of fracture of P2, 2 cases of extensor tendons, 8 fractures of P1 associated with section of the extensor tendon, 2 cases of PIP closed trauma (1 sprain, 1 dislocation), and 2 crush injuries of the extensor tendon at the PIP joint. The surgical technique combined a dorsal sinuous approach, tenolysis of the extensor tendon on the dorsum of first phalanx dorsal capsulotomy, and more rarely (3 cases), section of collateral ligaments. The mean pre-operative active flexion was 44 degrees and the mean post operative active flexion was 78 degrees, which represents a gain of 34 degrees of active movement. Thanks to a classification which incorporates the range of active flexion in PIP joint, and the lock of active extension we rated 3 results as excellent, 4 as good, 8 as useful and 4 as insufficient. We therefore improved the range of movement in 15 out of 19 cases, which seams very encouraging.

[Emergency pulp reconstructions]. / Reconstructions pulpaires en urgence.

Pulp reconstructions use numerous techniques ranging from simple debridement to local and microsurgical flaps. The authors analyse the various treatments, in which directed healing still retains numerous indications. Local flaps have a definite place, but they are not devoid of risks (iatrogenic stiffness). The indications are presented schematically in table form together with several examples. A wide range of techniques is necessary in order to treat the various lesions appropriately. Large defects are best treated by microsurgical transfer of great toe pulp with satisfactory results, which justifies their management in specialised centers.

[Foot replantation followed by tibial lengthening. Apropos of a case]. / Réimplantation d'un pied suivie d'un allongement tibial. A propos d'un cas.

The authors present a foot replantation case at the ankle level followed six months later by a tibial lengthening using the Ilizarov procedure. Performing the aforementioned lengthening following a replantation enables good nervous and vascular sutures, tension-free and ensures a satisfactory result.

Alkalinization of 0.5% lidocaine for intravenous regional anesthesia.

Although remaining a controversial issue, alkalinization of lidocaine or bupivacaine may shorten the time to onset and increase the duration of the sensory block. The aim of this study was to evaluate the effect of pH adjustment on the sensory and motor blocks during intravenous regional anesthesia (IVRA) with lidocaine. Thirty-one patients scheduled for minor hand surgery performed under IVRA were randomized into two groups: Group 1 (n = 14): 1% lidocaine, 3 mg/kg, diluted with the same volume of physiological saline solution (pH = 6.63 +/- 0.05), and Group 2 (n = 17): 1% lidocaine, 3 mg/kg, diluted with the same volume of 1.4% sodium bicarbonate (pH = 7.34 +/- 0.05). final concentration of lidocaine was thus 0.5% in both groups. Sensory block was assessed by pinprick every 2 minutes in areas corresponding to six terminal nerves: ulnar, median, radial, musculocutaneous, medial cutaneous nerve of arm and intercostobrachial, and medial cutaneous nerve of forearm. The time between release of tourniquet (at the end of surgery) and appearance of pain was recorded. Motor blockade was evaluated by asking the patient to squeeze strongly a blood pressure cuff previously inflated to 40 mmHg. This maneuver was performed before and every 2 minutes after injection. No statistical differences were found between the two groups whatever the parameter studied. In conclusion, there is no advantage (over plain solutions) to using pH-adjusted lidocaine during IVRA for hand surgery.

[Functional treatment of closed boutonnière deformity using a dorsal digito-palmar dynamic extension splint]. / Traitement fonctionnel des boutonnières fermées par attelle dynamique d'extension dorsale digito-palmaire.

We advise dynamic extensor splintage put on as early as possible within the first 6 weeks after the diagnosis of boutonniere deformity. This splintage runs from the dorsal aspect of the hand to the DIP joint which is left free to flex actively. This apparatus is left on for at least six weeks post injury. Sixteen patients have been treated in this way. Seven of them were monitored carefully. Only one had a bad result with DIP flexion still preserved. The others averaged a mean extension loss of 23 degrees, and no loss of extension in DIP joints. Active flexion both in PIP and DIP was perfectly preserved. The functional treatment without surgery seems to be a good technique in management of fresh rupture of the extensor mechanism in PIP joints.