Assessment of perfusion in normal carpal bones with dynamic gadolinium-enhanced MRI at 3 Tesla.

PURPOSE: To investigate the normal enhancement patterns of the scaphoid, lunate, and capitate bones with dynamic contrast-enhanced magnetic resonance imaging (MRI). MATERIALS AND METHODS: The study was approved by the hospital's Ethics Committee. Nineteen volunteers (13 female, 6 male; mean age 38 years) were examined and all gave written consent. Perfusion was assessed at 3 Tesla using dynamic contrast-enhanced MRI. After two-dimensional (2D) motion correction of the data set, regions of interest were placed in the capitate, lunate, and distal and proximal pole of scaphoid bone and from the mean signal intensities (SI), the enhancement was computed. The four locations were compared for time to peak, delay time, maximum enhancement, and maximum slope using Friedman's two-way analysis of variance. RESULTS: Typical SI versus time curves revealed two components: a faster component with strong contrast enhancement and a slow component with prolonged enhancement. The mean value (standard deviation, SD) for maximum enhancement was 51 (33)% in the capitate, 54 (25)% in the lunate, 51 (34)% in the proximal pole and 51 (28)% in the distal pole of the scaphoid. The result of the Friedman test showed no significant difference (P < 0.05) in the perfusion variables between the capitate, lunate, and distal and proximal scaphoid bones. CONCLUSION: Assessment of perfusion in normal carpal bone using contrast-enhanced MRI is possible. Optimization of the method and understanding of the normal perfusion may allow evaluation of pathological conditions such as osteonecrosis.

Vascularized bone grafting in a canine carpal avascular necrosis model.

BACKGROUND: Limited experimental research has been performed on the treatment of avascular necrosis (AVN) by vascularized bone grafting. QUESTIONS/PURPOSES: A new model simulating carpal AVN was created to investigate surgical revascularization of necrotic bone. METHODS: In seven mongrel dogs, AVN was induced by removal of the radial carpal bones bilaterally, deep-freezing, coating in cyanoacrylate, and reimplantation. A reverse-flow vascularized bone graft from the distal radius was implanted in the avascular radial carpal bone. The contralateral side served as an untreated ischemic control. Bone blood flow, bone volume, radiography, histomorphometry, histology, and MRI were analyzed at 4 weeks. RESULTS: Blood flow was substantially higher in grafted bones when compared with controls (14.68 ± 15.43 versus 0.27 ± 0.28 mL/minute/100 g). Blood flow correlated with increased osteoid formation and higher levels of bone turnover. T1 and T2 signals on MRI did not correlate with quantitative bone blood flow measurements. Necrotic bones with no blood flow had normal T1 and T2 signals, whereas revascularized bones had signal changes when compared with adjacent carpal bones. No major collapse occurred in any radiocarpal bone. CONCLUSION: In a canine experimental model, investigation of carpal AVN shows the ability of vascularized bone grafting to revascularize and remodel avascular bone. CLINICAL RELEVANCE: Surgical revascularization of necrotic bone induced by vascularized bone grafting results in increased bone perfusion and bone remodeling as compared with untreated necrotic bone. MRI T1 and T2 signals can be normal in necrotic avascular bone.

Evaluation and Management of Carpal Fractures Other Than the Scaphoid.

Fractures of the carpus can be debilitating injuries and often lead to chronic pain and dysfunction when not properly treated. Although scaphoid fractures are more common, fractures of the other carpal bones account for nearly half of all injuries of the carpus. Often missed on initial presentation, a focused physical examination with imaging tailored to the suspected injury is needed to identify these fractures. In addition to plain radiographs, advanced imaging such as CT and MRI are helpful in diagnosis and management. Treatment of carpal fractures is based on the degree of displacement, stability of the fracture, and associated injuries. Those that require surgical fixation often affect the congruency of the articular surfaces, are unstable, are at risk for symptomatic nonunion, are associated with notable ligamentous injury, or are causing nerve or tendon entrapment. Surgical strategies involve percutaneous Kirschner wires, external fixation, screws and/or plates, excision, or fusion for salvage. Owing to the intimate articulations in the hand, small size of the carpal bones, and complex vascular supply, carpal fracture complications include symptomatic nonunion, osteonecrosis, and posttraumatic arthritis.

Preiser disease after repeated local glucocorticoid injections: A case report.

RATIONALE: Preiser disease or avascular necrosis (AVN) of the scaphoid causes intolerable wrist pain and malalignment of the carpal bones. In previously reported cases, patients have had a history of steroid use for systemic illness such as autoimmune hemolytic anemia, systemic lupus erythematosus, or renal transplantation, or have had other risk factors, such as smoking, alcoholism, or infection. In particular, systemic glucocorticoid therapy has been most commonly associated with the disease. Although there are reports of AVN of the scaphoid induced by systemic glucocorticoids, no prior report has associated AVN of the carpal bones with repeated local injections of glucocorticoids. PATIENT CONCERNS: We present a case in which it was strongly suspected that AVN of the scaphoid was induced by repeated local glucocorticoid injections. The patient had no history of excessive alcohol use, smoking, or trauma, except for local repeated steroid injections. DIAGNOSES: Initially, she had diagnosed with de Quervain's disease and was treated by repeated local glucocorticoid injections followed by surgery for de Quervain's disease. Five years after surgery for de Quervain's disease, the patient presented at our hospital with sudden onset of intolerable pain in her right wrist without a history of trauma. In spite of nonsurgical treatment with rest, immobilization, analgesia, and surgery, her wrist pain was not improved. After further repeated local steroid injections in her wrist, radiographs, and magnetic resonance imaging of her wrist showed the AVN of the scaphoid. INTERVENTIONS: Surgery was performed and the fragmented proximal scaphoid and the entire lunate were resected. OUTCOMES: The diagnosis was confirmed according to the histopathological examination of the proximal scaphoid bone, which showed the characteristic of AVN of the scaphoid. At follow-up evaluation, radiographs of the right wrist showed no progression of osteoarthritis. The patient had no tenderness or residual pain at the wrist and had no desire to pursue additional surgery. LESSONS: We have presented a case with AVN of the scaphoid, which was strongly suspected to be associated with the repeated local steroid injections. Further studies are required to more fully elucidate the association between AVN of the scaphoid and repeated local steroid injections.

Vascularised bone graft for Kienböck disease: preliminary results.

We treated eight patients with lunatomalacia by harvesting a pedicled, vascularised bone segment from the dorsal aspect of the distal radius and grafting it into the lunate. Its effect on carpal collapse and clinical outcome was assessed at a mean follow-up of 29 months (range 13-42). Postoperatively patients had considerably less pain (45% during activity and 74% at rest). Postoperative mean range of movement was 65% (range 43%-76%) (SD: 13) of the unaffected side. Three patients had an excellent result, three had good results, one had a fair result, and one patient was unsatisfied. The mean postoperative disabilities of the arm, shoulder, and hand score was 29.8 (compared with 40.0 preoperatively).

Non-union of the scaphoid. Revascularization of the proximal pole with implantation of a vascular bundle and bone-grafting.

Eleven patients who had an ununited fracture of the scaphoid associated with loss of the blood supply to the proximal fragment were managed operatively with a combination of an inlay corticocancellous bone graft from the iliac crest and implantation of the second dorsal intermetacarpal artery, its accompanying venae comitantes, and a thin cuff of perivascular tissue. The absence of the blood supply to the proximal pole was evidenced both by radiographic changes--which included increased bone density, absence of normal trabeculae, and cystic changes--and by failure to observe bleeding bone during the operation. There were ten men and one woman. The average duration of non-union was fourteen months (range, six to thirty-three months). Six patients had had previous unsuccessful operative attempts to obtain union. Eight non-unions were in the proximal one-third and three, at the waist of the scaphoid. Union was achieved in ten patients at an average of ten weeks postoperatively. According to the wrist-scoring system of the Mayo Clinic, at an average of five years (range, 2.5 to eleven years), three patients had a grade of excellent; three, good; three, fair; and two, poor. Four patients had subsequent reconstructive procedures; radial styloidectomy, styloidectomy and resection of osteophytes, radioscapholunate arthrodesis, and total wrist arthrodesis were performed in one patient each.

Nonunion of fractures of the scaphoid tuberosity.

Fracture of the tuberosity of the scaphoid is common and usually heals without incident because of the good blood supply. We report four cases of nonunion of this fracture. Three of them were symptomatic and two required operative treatment.

Vascularity and osteonecrosis of the wrist.

This article outlines the vascular anatomy of the carpus, describing the extraosseous and intraosseus vascular systems and emphasizing the carpal bones at risk for osteonecrosis. Separate discussions of etiology, diagnosis, and treatment of osteonecrosis of the commonly involved carpal bones are included.

Evaluation of ischaemic necrosis of carpal bones by magnetic resonance imaging.

Nine patients with chronic pain in the wrist were examined by M.R.I. to evaluate its accuracy in the detection of ischaemic necrosis of carpal bones. In seven patients, M.R.I. confirmed scintigraphic and radiographic signs of ischaemic necrosis. In two patients with radionuclide accumulations, M.R.I. did not confirm the diagnosis: in one, M.R.I. was totally normal and in the other it showed signs of a healing scaphoid fracture. From this limited experience, M.R.I. seems to be a sensitive imaging modality which is more specific than scintigraphy.

Experimental osteonecrosis of the lunate. Revascularization may cause collapse.

Is lunate collapse in Kienböck's disease a consequence of spontaneous revascularization, leading to focal osteolysis? A literature review of osteonecrosis in other locations such as the femoral head and bone allografts showed clearly that the loss of mechanical integrity is due to cellular processes which follow the spontaneous restoration of blood supply. We found no evidence in the literature that the lunate has been shown to be avascular at the time of collapse. On the contrary, increased osteoclastic activity has been reported. We excised and reimplanted the lunate in two monkeys, and found spontaneous revascularization, leading to increased osteoblastic activity. Other parts of the bone were destroyed by osteoclasts, leading to collapse. This histological example suggests that it may be possible to make an analogy with osteonecrosis in other locations. Thus, changes on plain radiography may indicate that the bone is revascularized spontaneously. Before performing operative revascularization of the lunate, one should consider that revascularization is a probable cause for collapse.

Injury to the immature carpus.

Traumatic injury to the immature carpus is infrequent because of the sequence of carpal ossification, the resiliency of surrounding ligaments, and the vulnerability of the radius to fracture. Diagnosis requires careful palpation and suspicion, particularly in younger children. Treatment should consider the healing, growth, and modeling potential of the carpus.

External fixation for the treatment of Kienböck's disease.

With the advent of magnetic resonance imaging, the diagnosis of avascular necrosis of carpal bones can be made early, well before collapse and derangement of carpal mechanics occur. We believe that neutralization of forces early in the course of disease may permit natural healing (revascularization) of the bone. It is questionable whether tubular casts can supply adequate neutralization of force. We recommend the consideration of external fixation, rather than more extensive surgery, as a rational alternative for this purpose. After surgical revascularization, carpal bones go through a resorptive phase that makes them highly susceptible to collapse from compressive forces across the wrist. We advocate the postoperative use of an external fixator to neutralize these forces after a revascularization procedure is performed.

Internal fixation of scaphoid fractures.

Scaphoid fracture fixation is indicated in certain acute situations and for scaphoid nonunion. Internal fixation requires an understanding of the distinctive scaphoid anatomy with relation to its shape, blood supply, fracture healing, and radiographic evaluation. The choice of surgical approach varies with the fracture configuration and procedure planned. A variety of innovative implants are available to accomplish internal fixation of the scaphoid. The ultimate goal is to achieve union and restore stability to the carpus.

[Vascular pedicled transposition of the pisiform bone for treatment of lunate malacia]. / Die gefässgestielte Transposition des Os pisiforme zur Behandlung der Lunatummalazie.

In a prospective study we investigated the results of 18 patients with Kienböck's disease stage II as defined by Decoulx, treated with transposition of the pedicled pisiform. In eight cases of minus variance of the ulna, a radius shortening osteotomy was performed. There was an average follow-up of 30 months, X-ray investigations were done every six months after operation. 17 patients had less pain, 14 patients showed an improved range of motion of 30 degrees. Magnetic resonance imaging proved vitalizing of the pisiforme in 16 cases.

Vascularised pisiform bone graft. Indications, technique and long-term results.

The authors report their experience with the use of a vascularised pisiform bone graft based on the dorsal branch of the ulnar artery to provide osseous support and an efficient vascular aid especially in non-unions of the carpal navicular bone with avascular necrosis of its proximal pole and in stage III Kienböck's disease. The pisiform can replace the proximal pole of the navicular bone in totality. When implanted into the lunate, it stops its collapse and helps to revascularize it. The authors present the results achieved in 14 patients (12 male, 2 female), of which eight had a follow-up longer than 5 years The technique appears as an interesting alternative to carpectomies and partial intracarpal fusions which are usually proposed in advanced cases of these conditions.

Lunate plasty for Kienböck's disease: use of a pedicled vascularised radial bone graft combined with shortening of the capitate and radius.

We treated eight patients with Kienböck's disease (two patients each with stage 1, 2, 3a and 3b disease by Lichtman's classification) by removing a pedicled, vascularised bone segment from the dorsal aspect of the distal radius and engrafting it into the lunate. Additional shortening of the radius was performed in patients with the ulna-minus or null variant. Shortening of the capitate and capito-hamate fusion were also performed in patients with stage 3 disease. All patients were relieved of their wrist pain at rest and during movement, and the mean grip strength increased from 37% of that in the contralateral hand before surgery to 80% after surgery. The mean post-operative range of motion in the affected wrist was 92% of that in the opposite wrist in patients with stage 1 and 2 disease, and 53% in patients with stage 3 disease. Post-operative assessment revealed that four patients had excellent results, three had good results, and one had a fair result.

[Vascularized bone transfers in the wrist and hand]. / Les transferts osseux vascularisés au poignet et à la main.

More and more vascularised bone transfer (VBT) sites, free or pedicled, in the wrist and hand have been described since the 1980s. In the distal forearm, two main VBT: the fibula and the iliac crest, are used for large bone loss (> 6 cm) or for radio-carpal reconstruction. We report our experience of radio-carpal reconstruction using the distal-radio-ulnar joint transfer. At the carpal level, VBT are essentially used for "difficult" scaphoid pseudarthrosis: osteonecrosis, sclerotic bone or failures of conventional grafts and for lunate necrosis. Two pedicled VBT are frequently used for the scaphoid, a graft harvested from the antero-medial part of the distal radius (Kuhlmann) or a graft harvested from the postero-lateral part of the distal radius (Zaidemberg). For the trapezo-metacarpal joint, two new articular pedicle transfers can be used in some cases of trapezo-metacarpal arthritis. At the hand level, VBT are used for distal bone loss, "en bout de chaîne". Bone vascularisation is indispensable to preserve sub-chondral bone and avoid articular destruction. In children VBT are necessary to preserve the growth cartilage.

[Vascularized surgical rotation of a bi-articular trapezoid-trapeziometacarpal complex for the treatment of severe rhizarthrosis of the thumb]. / Rotation chirurgicale vascularisée du complexe bi-articulaire trapézoïde-trapézométacarpien pour le traitement de la rhizarthrose grave du pouce.

UNLABELLED: A new surgical procedure has been conceived to avoid persistent pain and to restore the functionality and pinch strength of the basal joint of the thumb destroyed by degenerative osteoarthritis. Since January 1998 a double total joint transposition was performed on eight patients, switching the trapezoid-metacarpal joint and the trapezio-metacarpal joint. A 180 degrees rotation of the bi-articular complex (trapezoid-trapezio-metacarpal joints) in its entirety was achieved, while preserving the intrinsic ligaments and vascular supply insured by the dorsal branch of the radial artery; the Cardan conformation in Physics of the trapezoid-metacarpal joint provided complete thumb motion. TECHNIQUE: skin dorso-radial approach of the wrist; arteriolysis of the dorsal branch of the radial artery at the anatomic snuff box and at its entrance into the first intermetacarpal space; metaphyseal osteotomy of the first and second metacarpal; capsulotomy all around the bi-articular complex; transfer and rotation of the trapezoid-trapezio-metacarpal bi-articular complex together with the dorsal branch of radial artery; osteotomy stabilisation by Kirschner wires; capsulo-ligamentous reconstruction; plaster slab immobilisation. Four weeks later the thumb moves actively; hand therapy starts six weeks post-operatively. Clinical and radiological controls were performed at two, four and six weeks, tomography at three months post-operation. Clinical assessment for three patients showed three good results and for the other five showed excellent outcomes, resulting in complete motion, stability of the first metacarpal and restored painless pinch strength of the thumb. Today the trapezoid-metacarpal joint seems to ensure pain relief, mobility and to solve the instability due to the collapse of the thumb column by restoring the bone chain of the first metacarpal ray.

[Three-phase bone scintigraphy of Kienböck disease].

Thirty-three joints in 31 patients of Kienböck disease were evaluated with three-phase bone scintigraphy. Follow-up studies were performed in 19 cases of them. The patients with increased ulnar blood flow on arterial phase and ample perfusion on venous phase in angiograms showed good clinical prognosis. This ample ulnar blood flow and perfusion might be essential for the recovery of this disease. Although staging was possible using static images alone, blood pool images provided more information about the present condition of lesions, such as hyperemic state and remodeling reactions. Blood pool image was indispensable for staging and analyzing lesions and evaluating post-operative course. Increased lunate perfusion in venous phase of angiograms and localized lunate uptake in blood pool images were the favorable signs, which were shown in most cases with good prognosis. It is concluded that three-phase bone scintigraphy gives useful informations for evaluating Kienböck disease which can not be obtained by conventional bone scintigraphy.

Histomorphometric evaluation of the effect of early exercise on subchondral vascularity in the third carpal bone of horses.

OBJECTIVE: To investigate histomorphometric changes in the cartilage and subchondral bone of the third carpal bone associated with conditioning exercise in young Thoroughbreds. ANIMALS: Nine 18-month-old Thoroughbreds. Procedures-Both third carpal bones of 9 horses (4 exercised spontaneously at pasture only and 5 given additional conditioning exercise beginning at a mean age of 3 weeks) were evaluated. Histomorphometric variables (hyaline and calcified cartilage thickness and collagen orientation; vascular channel area, number, and orientation; and osteochondral junction rugosity) of the third carpal bone, sampled at 4 dorsopalmar sites in the radial facet, were compared between the exercised and nonexercised groups. RESULTS: The vascular channel area measured at the 4 dorsopalmar sites was larger in the exercised group than in the control group, but none of the variables were significantly different between groups. Both groups had significant site-specific variations in all measured variables. Most importantly, the vascular channel area was highest in the most dorsal aspect. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that the mild exercise imposed in both groups during the developmental period appeared to be associated with an increase in the vascular channel area beneath the calcified cartilage layer in the third carpal bone. This increased vascular channel area could also be associated with high stress in the dorsal aspect of the radial facet, a region that is known to be vulnerable to osteochondral fragmentation.