[Osteosynthesis in distal intra-articular humeral fractures. External fixation with motion capacity]. / Bewegungsfixateur. Augmentierte (Re-)Osteosynthese bei distal intraartikulärer Humerusfraktur.

The rising incidence of distal intra-articular humeral fracture in elderly patients associated with osteoporosis frequently leads to difficulties in acute reconstruction and may result in early failure of internal fixation. The biomechanics of the elbow joint and especially the flexor group as well as the brachioradialis muscle as part of the extensor group is analyzed. The complex motion pattern of the transarticular muscle groups increases the load on internal fixation and may affect the interface between implant and osteoporotic bone. An external fixator with motion capacity serves to protect the internal osteosynthesis and secures the fixation in osteoporotic bone.

[Use of upper limb external fixation with motion capacity. Anatomical considerations]. / Anwendung von Bewegungsfixateuren an der oberen Extremität. Anatomische Grundlagen.

The use of external fixation in the upper limb requires detailed anatomical knowledge. The centre of rotation in the elbow joint has to be understood and the bony landmarks have to be identified. The joint mechanics and the mechanics of the external fixation device have to be collinear in a wide range of the natural motion capacity. Insertion of humeral and ulnar pins considering the specific anatomy is described and post-operative diagnostic aspects are illustrated.

Minimally invasive ankle arthrodesis with a retrograde locking nail after failed fusion.

A retrograde nail with posterior-to-anterior (PA) locking into os calcis, talus and tibia was used to correct deformity and achieve fusion after failed fusion. A variety of methods have been published to achieve union of the ankle and subtalar joint in a failed fusion situation. We have studied a retrograde locking nail technique through a 2.5-cm incision in the non-weightbearing part of the sole of the foot. Remaining cartilage in the ankle joint, where necessary, was percutaneously removed through an anterior approach and the locking nail was inserted after reaming of os calcis, talus and tibia. Locking screw insertion was in the sagittal plane (p.a. direction), in talus os calcis and tibial diaphysis using a nail mounted jig. Ten patients were entered in the study (age 27-60 years). The initial aetiology for attempted fusion was post-traumatic in nine cases and rheumatic in one case. There were 25 previous operations in the cohort not leading to fusion. An additional temporary external fixator was used in four cases to reach and maintain the optimum position for the procedure. The intervention time was 30-75 min. Dynamisation of the nail was performed after four months under local anaesthesia. The mean duration of follow-up was 4 years (3-5.5 years). Radiologically and clinically, fusion was achieved in 16 weeks (range, 12-20 weeks). There was no loosening of the implant or implant failure. A leg length discrepancy was avoided using this technique. There was one complication with varus malunion in a heavy smoker which united after corrective osteotomy, revision nailing and bone grafting. Patient satisfaction was measured on a scale (not visual analogue) of 0 (not satisfied) to 10 (completely satisfied); overall satisfaction averaged 9.5 points (range, 6-10 points). The postoperative ankle-hindfoot score of the American Orthopedic Foot and Ankle Society averaged 73.5 points (range, 61-81 points). Retrograde locked nailing with locking in the sagittal plane is a reliable minimally invasive procedure to achieve fusion of the ankle and the subtalar joint after failed fusion.

The "floating forearm" injury in a child: a case report.

The case of a eleven-year-old girl who had a fracture dislocation of the left elbow with entrapment of the ulnar nerve into the dislocated ulnar epicondyle anlage and unstable forearm fracture of the ipslateral upper extremity is described. This severe injury to the elbow and the ipsilateral forearm is termed "floating forearm" injury. The forearm was stabilized percutaneously and the elbow fracture dislocation, remaining unstable after internal fixation was treated with a pediatric elbow fixator with motion capacity.

[Posttraumatic elbow stiffness: planning and technical aspects of arthrolysis]. / Bewegungseinschränkung nach Verletzung des Ellenbogengelenkes: Planung und operative Strategie der Arthrolyse.

Posttraumatic limitation of range of motion in the elbow joint may be of extraarticular, intraarticular or mixed origin. If conservative management fails to improve elbow motion, arthroscopic arthrolysis, open arthrolysis and distraction arthroplasty are available as therapeutic options. Joint distraction for gradual lengthening of shortened ligaments and capsules is used to disimpact the humero-ulnar articular surface. Under distraction fixator controlled mobilization is carried out. The use of transarticular external fixation is particularly helpful in cases of subluxation in order to restore joint congruity and facilitate postoperative physiotherapy. The postoperative management plays an important role in achieving the therapeutic goal.

Ultrasonographic stress test of the metacarpophalangeal joint of the thumb.

The purpose of this study was to evaluate functional ultrasound as a tool for detecting an ulnar collateral ligament injury of the thumb. The feasability of using ultrasound for imaging the thumb joint space was tested in a pilot study, using ultrasound and dissection in 14 cadaveric hand specimens. To test this method clinically, both metacarpophalangeal joints of the thumb in 461 healthy volunteers were examined using ultrasound (11 MHz) under radial stress. The distance between the innominate tubercle of the first metacarpal head to the proximal phalanx was measured. The mean distance between the first metacarpal head and the proximal phalanx (n = 461) was 4.5 mm (standard deviation, 0.65 mm) on the right side and 4.6 mm (standard deviation, 0.61 mm) on the left side. These data were compared with data of 25 patients with an operative diagnosis of rupture of the ulnar collateral ligament of the thumb. The difference in joint space between the injured and uninjured sides was 2.25 mm (standard deviation, 0.46 mm). The metacarpophalangeal joint space can be reproducibly detected on high-frequency ultrasound. An increased gap seen on ultrasound is indicative of a rupture of the ulnar collateral ligament of the thumb.

[Arthrolysis of the elbow joint]. / Arthrolyse des Ellenbogengelenkes.

A stiff elbow is usually defined as having less than 30 degrees in extension or flexion less than 130 degrees. Most activities of daily living are possible if the elbow has a range of motion of 100 degrees (30-130 degrees of flexion, Morrey's arc of motion). Loss of motion of the elbow is not uncommon after trauma, burns, or coma and severely impairs upper limb function. Loss of motion may be difficult to avoid and is challenging to treat. Detailed analysis of the etiology and diagnostic evaluation is of utmost importance for planning any surgical intervention for elbow stiffness. Current operative techniques, such as arthroscopic or open arthrolysis and closed distraction with external fixation (arthrodiatasis), are presented and evaluated. Elbow arthrolysis is a technically demanding procedure, but if indication and techniques are used correctly and surgeon, physiotherapist, and patient are familiar with the procedure, good long-term results may be achieved.

Percutaneous arthrodesis of small joints in the hand. A minimum three-year follow-up.

Our aim in this prospective study was to evaluate a minimally invasive technique for percutaneous arthrodesis of the small joints in the hand. Thirteen arthrodeses were undertaken in 11 patients, eight women and three men. After the percutaneous removal of articular cartilage, the bony surfaces were aligned in a predetermined position and stabilised using a percutaneous screw system. The mean follow-up was 38.6 months (36 to 56). Bony union was achieved in 12 cases (ten patients) between nine and 12 weeks after surgery. In one patient a second operation was required to obtain union and another developed a painless nonunion after premature removal of the implants.

[Narrowing of the third extensor tendon compartment in minimal displaced distal radius fractures with impending rupture of the EPL tendon]. / Einengung des dritten Strecksehnenfaches bei gering dislozierter distaler Radiusfraktur mit Gefahr einer Extensor pollicis longus-Sehnenruptur.

Delayed ruptures of the extensor pollicis longus tendon (EPL) occur in about 0.7 percent following undisplaced distal radius fractures. Two possible mechanisms are mainly discussed in the literature: A mechanical irritation of the tendon caused by a sharp edge of the fractured bone and a direct microvascular compromise of the poorly vascularized tendon. In undisplaced fractures, however, a mechanical irritation seems less likely. In the cases here described we were able to demonstrate a fragment displacement in the area of Lister's tubercle suspected by the native X-ray and further evaluated by a CT scan. The use of CT scans even in minor displaced distal radius fractures involving Lister's tubercle may demonstrate a direct contact of the EPL tendon with a sharp edge of this fractured bone and make adequate surgery possible.

Antegrade femoral nailing: an anatomical determination of the correct entry point.

Operative problems in the application of femoral locking nails are frequently related to an unfavourable entry point at the greater trochanter. Especially in more distally located fractures the nail is forced to follow the cortex abutted medullary canal. A wrong defined entry point either in the medio-lateral or dorso-ventral direction inevitably leads to tension between nail and femur. Forceful insertion in this situation may cause disastrous iatrogenic comminution at the fracture side or additional fractures at the proximal femur. To avoid tension between nail and femur the best suited entry point must be defined according to the natural medullary cavity. In 16 human cadaver femora, the natural medullary cavity was opened and after cleaning filled with a radio-opaque substance (barium sulphate). Twelve radiographs where taken from each bone starting with the anterior-posterior view and then turning the bone axially in steps of 15 degrees. From these radiographs, the ideal entry point at the greater trochanter was calculated. In 88% of the specimen the ideal entry point for a straight nail was found constantly at the medial border of the greater trochanter overlaying the tendinous insertion of the piriformis muscle. The axis of the medullary cavity was in average 2.1cm anterior to the dorsal border of the greater trochanter. In a second step the ideal entry point for bend nails was calculated. According to this calculation a bend nail with a radius of 100 cm needs an entry point 0.7 mm anterior to the dorsal edge of the greater trochanter. Overlaying the hook like shape of the posterior part of the trochanter.

[Presentation of a simple method of preoperative soft-tissue distraction in Dupuytren's contracture grade IV]. / Vorstellung einer einfachen Methode zur Vordistraktion der viertgradigen Dupuytrenschen Kontraktur.

We describe a technique of continuous preoperative soft-tissue distraction in Dupuytren's contracture grade IV using an unilateral external fixator which is simple to apply. The operative technique and the result are demonstrated.

[Distraction arthrolysis with humero-ulnar motion fixator]. / Die Distraktionsarthrolyse mit humeroulnarem Bewegungsfixateur zur Behandlung der posttraumatischen Ellenbogensteife.

Distraction arthroplasty in the treatment of elbow stiffness with an external fixator and subsequent fixator assisted mobilization is described. Joint distraction is employed to correct the shortened ligaments and capsule and permits the separation of articular surfaces. After intraoperative joint distraction, a phase of relaxation followed by fixator assisted mobilization is carried out. The use of the motion fixator is described and additional measures discussed. This technique is particularly valuable in joint subluxation or persistent joint dislocation and allows for reduction after distraction in order to secure joint congruity. Postoperative management is a key factor for the success of the management protocol.

[Gradual wound closure by dermatotraction of the hand]. / Der graduelle Wundverschluss durch Dermatotraktion an der Hand.

There are various treatments for skin defects. In our study we used a skin-stretching device for the closure of six skin defects of the hand and wrist (Sure-Closure System, Life Medical Sciences, Inc., Princeton, N.J.). Three defects were closed completely. The size of the other three wounds was reduced by 50 to 70%. We saw no complications. The skin-stretching device helped to close skin defects with local sensate tissue.

Fine thread versus coarse thread. A comparison of the maximum holding power.

For osteosynthesis in the epiphyseal region of long bones, specialized screw types are available to achieve a better purchase in cancellous bone. Typically, the cancellous bone screw has a large outer thread diameter with a relatively small core diameter and a great pitch. Due to its dimensions, this screw type is not suited for the cancellous bone areas in hand and foot surgery, respectively. Fine machine screws are better adapted to the bone dimensions in this part of the skeleton. To compare the holding power of fine machine screws with the holding power of other screw types available in the market, a biomechanical study was undertaken. Different screw types were compared: 4 mm cancellous screw, 3.5 and 2.7 mm cortical screws and three different diameters of a fine machine screw (2.2, 1.6 and 1.2 mm). Both cortical screws were tested in pretapped and self-tapping version. Polyurethane foam and bovine cancellous bone were tested. The screws were applied according to the manufacturer's instructions and an axial extraction force was applied. The 4 mm cancellous bone screws were superior to all the other screws in both test materials (P<0.05). The 3.5 mm cortical screw showed a significant difference compared to the 2.7 mm cortical screw in both materials. A significant difference between the self-tapping and pretapped screws of the same diameter was only found in the 3.5 mm cortical screws in polyurethane foam (P<0.05). Interestingly, the maximum holding power of the 2.2 mm fine machine screws in homogeneous test material (polyurethane foam) was as high as the holding power of the 2.7 mm cortical screws (P<0.05). In natural bovine cancellous bone, the result was even more striking. There was no significant difference between the 2.2 mm fine machine screws and the 3.5 mm cortical screws (P<0.05). Relative to their thread diameter, the fine machine screws were superior to conventional cancellous and cortical screws in cancellous bone. The high holding power of this screw type is at least partly due to the impaction effect of the drilling debris between the thread and the abutting spongy bone structure.

Extraarticular external fixation in distal radius fractures pinplacement in osteoporotic bone.

External fixation is a well accepted treatment option in distal radial fractures. The fixator can be used in two different ways: joint bridging or extraarticular. The extraarticular technique presumes that the fracture does not involve the radio-carpal joint and that the distal fragment is broad enough to accommodate two fixator screws. Taking into account that the majority of distal radius fractures occur in elderly female patients the question arises whether osteoporotic bone is an obstacle to extraarticular external fixation. Bone slices of 2mm thickness were cut out of six human cadaver radii with a mean age of 76 years (from 65 to 94 years) in the saggital plane. A radiograph of each slice was digitized and the distribution of gray values measured. It was found that the radiographic density was highest at the palmar side of the distal radius in a triangular area built by the palmar lip of the radius. In this region, even in severe osteoporotic bone, strong trabeculae are visible running parallel to longitudinal axis of the radius. Fixator screws inserted into the distal radial fragment especially in an osteoporotic situation should be securely anchored in the palmar lip of the distal radius.

[Minimally invasive management of metacarpal I fractures with a mini-fixateur]. / Minimalinvasive Versorgung von Metakarpale I-Frakturen mit einem Minifixateur.

Displaced perarticular fractures of the first metacarpal are mainly treated operatively due to the importance of the first ray for hand function. Open reduction and internal fixation as well as minimal-invasive techniques using minifixator systems may be employed. We use a minifixator, which allows pin-positioning even in small perarticular fragments eliminating the necessity of bridging joints. The anatomical basis, operative technique, and data of seven patients treated according to this method and results are presented. Range of motion according to the neutral-zero-method, tendon gliding, five-second-holding power, and force grip were equal compared to the uninjured contralateral side. The use of a minifixator to stabilize perarticular fractures of the first metacarpal includes the advantages of a minimal invasive procedure, respects the advantages of conservative fracture treatment, and permits secure fracture fixation after reduction.

The anatomical base of unilateral external fixation in the upper limb.

Unilateral external fixation requires an anatomically sound implantation of screws into the upper extremity. Detailed knowledge about the anatomical situation in the areas of pin implantation is of great importance. This paper focuses on relevant anatomical landmarks when implanting screws for external fixation in the humerus, the elbow, the forearm and the hand by studying anatomical specimen.

Transarticular fixation with the capacity for motion in fracture dislocations of the elbow.

Post-traumatic stiffness of the elbow joint is a frequent result of immobilisation leading to severe disability in the use of the upper extremity. Recognition of the tendency to stiffness leads to the assumption that the strong self-healing forces of the capsule and ligament apparatus converts the initial instability of the joint after ligament disrupture, into a high-grade undirected stability following immobilisation. Directed stability as it is produced by the natural ligament apparatus of the joint on the other hand produces a guided movement of the joint in one direction. These theoretical considerations lead to the idea that the self-healing forces of the ligament apparatus under continuous guided movement of the joint will result in a stable and movable joint to allow healing of the compromised soft tissue envelope and moreover to maintain free soft tissue access without compromising the stability. For this a unilateral fixator with motion capacity was developed. The joint bridging application approaches the humerus and ulna from the lateral side. The proximal pin group is inserted into the proximal region of the humerus respecting the radial nerve. The distal pin group is implanted from the dorsal side into the middle third of the ulna. The fixator has a hinge joint. The design of the fixator clamps, bars and the hinge joint allows simple alignment with the rotational axis of the elbow. Pro- and supination of the forearm is unhindered. Flexion and extension can be permitted according to the soft tissue situation.