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An unusual lesion developed in the trapezoid of a 25-year-old man. The tumor had histologic features most consistent with a diagnosis of chondromyxoid fibroma and had not recurred four years after curettage and bone grafting.
Various phenomena have been observed subsequent to plate osteosynthesis, for example, refracture after plate removal. Experimental research has shown that changes in the cortex occur within the first three months after plating and again several months later. These changes are independent of the fracture and take the form of porosis under the plate and excessive bone growth around the plate. Porosis under the plate was regarded until recently as being due to unloading of the bone by the plate, also known as stress shielding. Investigations of the relationship between bone porosis and the changes in periosteal blood supply due to its compression by the plate, however, have been neglected. In this study, the effect of plate properties such as structural stiffness ('unloading'), implant material, and plate contact surface (altered periosteal blood supply) on bone after osteosynthesis were investigated. This was done by comparative histomorphometry of the altered bone in sheep after application of four plates differing in the above-mentioned properties. After plating the sheep tibia with a trapezoid plate with narrow contact surface, significantly larger bone cross sections were observed one year after the operation and considerable bone growth around the plate. The area of early temporary porosis in the cortex under the plate as observed in the first nine weeks and after one year was not significantly different for any particular plate, all of which were applied subperiosteally. The trapezoid plates were easier to remove, thus causing less damage to the bone lamellae along the sides of the plate. The marked increase in bone cross section after one year and the larger areas of bone growth around the trapezoid plates with smaller contact surface can be attributed to the larger grooves cut along the sides of the plates. Cortical porosis was mainly the result of impaired periosteal blood supply which was of equal size in all groups as a result of careful periosteal stripping and subperiosteal plate insertion. It was assumed that applying the plate onto the periosteum would be associated with effects on periosteal blood supply directly related to the plate and consequently cortical porosis. Plate related stress shielding and the implant material had no significant effect on the extent of cortical porosis.
The intraosseous and extraosseous vascularity of carpal bones was studied in 75 cadaver limbs. Vascular patterns were correlated with the clinical incidence of avascular necrosis, and at-risk patterns of vascularity were identified. The carpal bones were found to fall into three groups. Group 1, which consisted of the scaphoid, the capitate, and eight percent of the lunates, had either vessels entering only one surface or large areas of bone that were dependent on a single vessel. This group was the most vulnerable to posttraumatic avascular necrosis. The bones of Group 2, the hamate and the trapezoid, were characterized by the absence of internal anastomoses. Although these bones are theoretically at risk, they do not undergo avascular necrosis. Group 3 bones, which included the trapezium, the triquetrum, the pisiform, and 92% of the lunates, had rich internal anastomoses and were at least risk of undergoing avascular necrosis. Examination of the arterial anatomy of bones that undergo avascular necrosis in other regions of the body led to a classification based on the types of vascular interruptions that place particular bones at risk. In some, i.e., the scaphoid and the capitate, a pure intraosseous disruption resulted in avascular necrosis; in others, i.e., the femoral head and a small percentage of lunates, an extraosseous disruption was sufficient to produce avascular necrosis. A third class, which included the talus and the majority of lunates, had an adequate intraosseous blood supply and good extraosseous vascularity. This pattern required severe extraosseous or a combination of intraosseous and extraosseous injury to lead to avascular necrosis.
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The authors report their experience of 5 patients (4 males, 1 female) with a mean age of 36.4 years (min 25 years, max 45 years), undergoing triscaphoid arthrodesis between May 1989 and August 1993. The patients suffered from rotatory dislocation of the scaphoid (1 case) and stage 3A of Kienboeck's disease according to Lichtman's classification (4 cases). The paper describes the surgical technique used for partial arthrodesis of the wrist performed using plexual anesthesia. A dorsal access route is used through a curved longitudinal skin incision corresponding to the anatomical site of the scaphoid. The skin flaps are then peeled back revealing the surface veins and sensitive branches of the radial nerve which are isolated and conserved. Having cut through the retinaculum of the extensors, the extensor tendons are spread so as to reach the joint capsule which is sectioned crosswise. After the bone to be fused have been exposed, the cartilage is removed from the joint faces between the scaphoid, trapezium and trapezoid and, using a osteotribe, the subchondral bone is removed to reveal the spongy bone, leaving a space of approximately 6 mm between the spongy surface of the bones to be fused. Arthodesis is stabilised using Kirschner wires or metal minicambres enclosing scaphoid, trapezium and trapezoid. Spongy tissue is taken from the distal radial head and used as a graft to fill the spaces created between them which will consolidate over time. The wrist is immobilised in a plaster cast for 8 weeks before starting functional rehabilitation. Patients were checked both clinically and radiographically with a mean follow-up of 36.4 months (min 25, max 50 months). Using the assessment criteria proposed by Minami et al. excellent results were obtained in 4 patients (80%) with the disappearance of painful symptoms, joint excursion 50% greater than the normal wrist, and hand grip 70% greater than in the controlateral hand. There was good radiographical consolidation of the arthrodesis. Poor results were only recorded in one case (20%) with persisting pain and functional impotent. Radio-scaphoid arthrosis was observed radiographically consequent to hypercorrection of the scaphoid with a radio-scaphoid angle of less than 45 degrees. The authors underline the technical difficulty of this arthrodesis characterised by reduction of the scaphoid in a correct position in which the radio-scaphoid angle must be 45 degrees when measured from a lateral position. Lastly, the authors conclude that this from of arthrodesis may be used with good results to treat wrist pathologies such as rotatory scaphoid dislocation, triscaphoid arthrosis and Kien-boeck's disease at stage 3A according to Lichtman. They also affirm that arthrodesis limited to the wrist is preferable to total arthrodesis because it enables some joint movement to be conserved which is important for hand function.
Scapho-trapezio-trapezoid arthrodesis for the treatment of Kienböck's disease is recommended as a salvage procedure for Stage III A and B in the Lichtman classification. This study reviews the results of 26 patients with stage III of Kienböck's disease treated by STT-arthrodesis. 26 patients (16 male, 10 female) were treated by STT-arthrodesis between 1993 and 1998. Fusion was established after seven weeks average. All patients were examined, the mean follow-up time was 35 (10 to 72) months. Active range of motion showed 63% of extension/flexion and 51% of radial/ulnar deviation on average, compared to the uninjured hand. Mean preoperative and postoperative pain scores were 58.4 (non-stress) vs. 82.5 (stress) and 16.4 (non-stress) vs. 33.7 (stress), eight patients claimed complete pain relief. Grip strength improved to 71% of the opposite side. Total DASH score reached 24.8. 20 of the 26 patients were satisfied with the final result and would undergo the operation again. We found a significant reduction of pain, a slightly reduced grip strength and a satisfying functional wrist mobility after STT-arthrodesis. Carpal height was unchanged and the carpal collapse did not progress. The mid-term data support that STT-arthrodesis will stand the test of time.
The use of registration techniques to determine motion transformations noninvasively has become more widespread with the increased availability of the necessary software. In this study, three surface registration techniques were used to generate carpal bone kinematic results from a single cadaveric wrist specimen. Surface contours were extracted from specimen computed tomography volume images of the forearm, carpal, and metacarpal bones in four arbitrary positions. Kinematic results from each of three registration techniques were compared with results derived from multiple spherical markers fixed to the specimen. Kinematic accuracy was found to depend on the registration method and bone size and shape. In general, rotation errors of the capitate and scaphoid were less than 0.5 deg for all three techniques. Rotation errors for the other bones were generally less than 2 deg, although error for the trapezoid was greater than 2 deg in one technique. Translation errors of the bones were generally less than 1 mm, although errors of the trapezoid and trapezium were greater than 1 mm for two techniques. Tradeoffs existed in each registration method between image processing time and overall kinematic accuracy. Markerless bone registration (MBR) can provide accurate measurements of carpal kinematics and can be used to study the noninvasive, three-dimensional in vivo kinematics of the wrist and other skeletal joints.
BACKGROUND AND PURPOSE: The aim of this study was to evaluate the effectiveness of surgery treatment in patients with posttraumatic fractures with dislocation of the cervical spine. MATERIAL AND METHODS: A retrospective review was carried out in 24 patients suffering from posttraumatic fractures of cervical spine segments with dislocation treated surgically at the Department and Clinic of Neurosurgery and Neurotraumatology, University of Medical Sciences in Poznań between 1998-2002. The study included 19 (79.2%) males and 5 (20.8%) females, aged from 16 to 60 years (the average age was 35.5). Traumatic lesions of cervical vertebral segments were localized as follows: level C3-C4 - 3 cases; C4-C6 - 17 cases; and at C6-Th1 - 4 cases. A three-grade scale was used to assess the severity of spinal cord trauma. On admission a complete transverse spinal cord syndrome was observed in 6 patients. Radiological investigations included X-ray (24 cases), CT (2 cases) and MRI (22 cases). With this in mind, the osteometric indices of the spine axis deformity were established: the index of anterior displacement of the vertebrae, the angle of local kyphosis (assessed by the Cobb's technique) and the lordosis curvature index. RESULTS: In all cases the operation was performed using the anterior approach. Surgery included anterior decompression and stabilization of the cervical spine by means of a bone graft or acrylic cement and trapezoidal or "S" plate. The postoperative neurological condition improved in 21 (87.5) patients and correction of the cervical axis was achieved in 24 (100%) cases. Postoperative neurological deficits were intensified in 2 cases and were regressive. The mortality rate was 4.2% (1 case). CONCLUSIONS: Osteometric radiological indices enable the bone structure posttraumatic lesions of the cervical vertebral column to be evaluated. This type of internal stabilization makes it possible to restore the alignment of the anterior column and immobilization of the appropriate vertebral segments.
OBJECTIVE: To characterize the features and prevalence of radiographic abnormalities of the wrist in children with Kashin-Beck disease (KBD) and to determine whether the presence of radiographic abnormalities in the wrist correlates with the severity of KBD. DESIGN AND PATIENTS: Two hundred and eight posteroanterior radiographs of the right hand (including wrist) in children with KBD, ranging in age from 4 to 11 years (mean age 7.7 years), from endemic areas of China were reviewed. Carpal bony margins were evaluated for blurring, thinning, irregularity with and without sclerosis, interruption, depression or destruction. The radiocarpal, intercarpal and carpometacarpal joints were assessed for widening or narrowing. The severity of the disease was graded using the hand criteria from the Chinese Radiographic Criteria of KBD Diagnosis, which classifies the following five types according to the location of the hand involved: I, metaphysis; II, diaphysis; III, I+II; IV, metaphysis and epiphysis; V, II+IV. RESULTS: Of the 208 children, 95 had abnormalities in the hand but not in the wrist; 108 had both hand and wrist abnormalities; only five had abnormal wrist findings without any hand abnormalities. Of the 108 cases with wrist abnormalities, all the carpal bones were involved in 33 cases, of which the hand types were either IV or V. However, any individual carpal bone, or combination of bones, may become involved. The carpal bones most likely to show abnormalities were the capitate and the hamate (93%), followed by the triquetrum (31%), the lunate (9%), the scaphoid (6%), and the trapezoid and the trapezium (5%). The pisiform bones were not evaluated because they cannot be seen on the overlapping posteroanterior radiographs. The most commonly involved carpal joint was the midcarpal joint (42%). CONCLUSIONS: Recognizing carpal abnormalities on radiographs is helpful for the diagnosis of KBD and the evaluation of the severity of the disease. The more severe the KBD, the more likely that the carpal bones will be involved. The capitate and hamate are frequently affected if the disease involves the carpal bones.
Wax reconstructions according to Born's methods were performed from serial 10-micron sections of the wrists of human embryos (B. Tardif) to study the triangular cartilage and central bone of the carpus. A subsequent morphological study of the adult scaphoid bone was conducted in the light of embryological data. The triangular cartilage was observed in 4 of 38 carpi of embryos with a craniocaudal length of 40 to 69 mm, flatten between the ulna and triquetrum, on the inferior surface of the mesenchymal bud of the triangular ligament. The central bone of the carpus is constant in the embryo, between the inferior surface of the radial chondrification centre, capitatum, trapezium and trapezoid. In one case, the two wrists of the same embryo presented two central nuclei, leading to the distinction of two different formations:--the constant C2 embryonic central bone, trapped between capitatum, trapezoid and trapezium, which participates in the constitution of the scaphoid by fusion with the radial chondrification centre;--the C1 central bone, a rare supernumerary bone in adults, close to the inferolateral angle of the lunatum, on the dorsal surface of the carpus. These embryological data support. Westoll's theory concerning the filiation of the thoracic limb since the fin of crossopterygians, with deviation of the mechanical axis related to the development of weightbearing on the ground. The scaphoid bone must to be assimilated to a cube, but to an irregular tetrahedron, composed of two inverted pyramids joined by their bases. The inferior pyramid, articulating with he trapezium, trapezoid and capitatum, is concerned by morphological variations of the bone, which can present variable configurations between the two extreme morphotypes: the massive type and the strangulated type. The inferior pyramid, constituting the scaphoid, is derived from the central cartilage and presents the same relations. Variations of the volume of this inferior part of the bone are related to the more or less marked regression of this chondrification centre of the embryonic carpus. These variations of the bone can be expressed in terms of a scaphoid index, by calculating the relationship between the greatest dimension and the width of the narrowed portion.
This article describes a modification of the double-osteotomy radial technique that has been described previously and summarizes our clinical experience with this method in 4 female patients. All patients had improvement in functional motion and were satisfied with the improved appearance of their wrist after surgery.
Roentgenograms of a 46-year-old Caucasian man with progressive swelling and pain at the base of the thumb who had been treated for arthritis showed an enlargement of the trapezium. The entire bone and surrounding ligaments were removed and an iliac bone graft was used to fuse the trapezoid to the first metacarpal. Sections of the tumor were diagnosed as chondrosarcoma. No recurrence is apparent 3 years after excision.
To clarify the pathology of radial-sided wrist pain with inconclusive X-ray and MRI findings, we performed arthroscopic examinations of 11 wrists in 10 patients. Physical examination and various image investigations could not identify the cause of the pain. Arthroscopy revealed partial to complete tears of the scapho-lunate interosseous ligament and synovitis and/or chondral bone defects at the scaphotrapezio-trapezoidal joint in all 11 wrists. Surgical procedures consisted of eight simple synovectomies, two ligament reconstructions and one percutaneous pinning. Pain relief was achieved in 10 wrists. One wrist which had a simple synovectomy did not recover, so underwent secondary scaphotrapezio-trapezoidal fusion. In conclusion, we found that various degrees of scapholunate interosseous ligament tear and scaphotrapezio-trapezoidal joint osteoarthritis were the main causes of radial-sided wrist pain with inconclusive X-ray and simple MRI findings.
The study included 18 patients (28 feet), between 4 and 14 years of age. Complete homogeneous correction of the neglected clubfoot was achieved by performing a trapezoid resection osteotomy from the cuboid bone after performing an extensive posteromedial soft-tissue release. The procedure did not sacrifice any articular cartilage and allowed realignment of the forefoot. Tibialis anterior tendon transfer to the cuboid was performed in all feet to eliminate its deforming action and to help maintain the desired degree of correction. A Dwyer calcaneal lateral closing wedge osteotomy was needed in 12 feet and was performed concomitantly with the other procedures. After an average follow-up of 26 months (range 8-31 months) 14 (50%) feet had a good result with normal features, 11 (39.3%) feet had a fair result with definite improvement, and three (10.7%) feet had a poor result with limited improvement. Both good and fair results were considered satisfactory. Patients with tight ligaments were significantly more likely to have a poor outcome (p < .0005). However, neither the patient's age at the time of surgery nor the severity of the deformity was significantly associated with unsatisfactory results. The procedure is strongly recommended in supple feet with resilient ligaments, even in teenagers with severe deformity. In severely deformed rigid feet, the procedure serves to minimize bone resection, thus preventing excessive shortening of the foot if a triple arthrodesis should become necessary at a later date.
STUDY OBJECTIVE: To evaluate the accuracy of day 4 bone scans in predicting the presence or absence of fracture in patients with "clinical scaphoid fracture." DESIGN: Prospective sensitivity study of ED patients with clinical scaphoid fractures. Each patient was immobilized in a thumb spica cast and had day 4 bone scans of both wrists and hands. Blinded day 4 bone scan results were ultimately compared with the diagnosis on day 14 when patients returned for repeat clinical examination and radiographs. In cases of equivocal radiographic or clinical examination results, a day 14 bone scan was performed. SETTING: Two tertiary care teaching hospital emergency departments. PARTICIPANTS: All ED patients older than 16 years with the diagnosis of clinical scaphoid fracture were eligible. RESULTS: Ninety-nine patients were enrolled and successfully completed the study protocol from October 1990 through November 1992. One patient had bilateral injury, for a total of 100 completed studies. Day 4 bone scans were 100% sensitive and 92% specific, for a positive predictive value of 65%, a negative predictive value of 100%, and accuracy of 93% (95% confidence interval, 88%, to 98%). Many other types of fractures were identified on the day 4 scans, including those of the triquetra, distal radius, capitate, hamate, trapezoid, trapezium, and metacarpals. CONCLUSION: Day 4 bone scans are an accurate means of ruling out scaphoid fracture. However, because of a significant number of false-positive scans at day 4, they do not reliably confirm the diagnosis of scaphoid fracture. The bone scans also permitted identification of several other wrist fractures that had not been radiographically apparent.
We describe a modification of the technique for arthrodesis of the joints between the scaphoid, the trapezoid and the trapezium (the S-T-T joint) described by Sandow, that involves the en bloc resection of a cylinder of bone incorporating a portion of each of the scaphoid, trapezoid and the trapezium, using a hollow mill, and replacing it with a cylindrical graft of exactly the same size taken from the distal radius. The procedure is relatively quick and easy with a high rate of fusion and must be regarded as a preferable alternative to other, more complex procedures.
Os styloideum is an immobile bone protrusion, located on the dorsum of the wrist between the trapezoid, capitate, and the second and third metacarpals, which may be associated with wrist pain. It usually presents in adults after degenerative changes occur. We report a case of a 12-year-old girl who presented with os styloideum. She was evaluated with plain radiographs, bone scintigraphy, and wrist CT. Plain radiographs were initially interpreted as normal. Bone scintigraphy demonstrated focal tracer uptake in the right trapezoid. CT demonstrated an os styloideum fused to the right trapezoid associated with secondary degenerative changes. Os styloideum is a rare cause of wrist pain in children.
Failure of an orthopaedic fixation due to stress shielding and consequent screw loosening is a major concern among surgeons: the loosened screws could not only interfere with the healing process but also endanger adjacent anatomical structures. In this study, the effect of the screw's engineering design (dimensions, profile shape and material properties) on the load sharing with adjacent bone and consequent bone resorption was tested, using a set of two-dimensional computational (finite element) models. An algorithm simulating local bone adaptation to strain energy density (SED) mechanical stimuli was developed and used to evaluate the biomechanical performances of different commercial screws. Two new designs, a 'graded-stiffness' composite screw, with a reduced-stiffness titanium core and outer polymeric threads, and an active-compression hollow screw that generates compressive stresses on the surrounding bone, were also evaluated. A dimensionless set of stress transfer parameters (STPs) were utilised for ranking the performances of the different screws according to the expected screw-bone load sharing and its evolution with adaptation of the surrounding tissue. The results indicated that commercial wide (6 mm thread diameter) trapezoidal and rectangular screw profiles have superior biomechanical compatibility with bone (i.e. predicted to be stable after 2 years). The graded-stiffness and active-compression screws provided the best biomechanical performances: bone loading around them was predicted to decrease by no more than 15% after 3 years, compared with a decrease of 55-70% in bone loading around commercially available screws. Computer simulations of bone adaptation around orthopaedic screws are demonstrated to be effective means for objective and quantitative evaluation of the biomechanical aspects of implant-tissue compatibility.