Percutaneous treatment of carpal, metacarpal, and phalangeal injuries.

Percutaneous fixation of hand fractures is a common technique that takes advantage of the subcutaneous nature of hand bones, their small size, and their limited loading potential for stress placed on hardware. Percutaneous wire fixation supplements cast fixation when plaster cannot hold particular reductions, and allow surgical fixation with limited postoperative swelling. In the first part of the current study, the types of wires that are used for hand fixation, fluoroscopy, helpful instruments, and the basic techniques used for this type of surgery are discussed. In the second part of the study, specific fixation techniques for different fractures of the carpals, metacarpals, and phalanges are outlined.

Nonepiphyseal ossification and pseudoepiphysis formation.

Direct ossification extending from the metaphysis into the epiphysis preceded and continued to be more mature than formation and expansion of the typical epiphyseal ossification center at the opposite end of each longitudinal bone of the hand and foot. Direct metaphyseal to epiphyseal ossification usually started centrally and expanded hemispherically, replacing both physeal and epiphyseal cartilage simultaneously. When remnants of the "physis" were retained, however, while juxtaposed epiphyseal cartilage was replaced, a pseudoepiphysis formed. Three basic patterns of pseudoepiphysis formation were evident: (a) a central osseous bridge, (b) a peripheral osseous bridge, and (c) multiple bridging. In each condition, the remnant of the "physis" lacked typical cell columns capable of contributing to the postnatal longitudinal growth of the involved bone. Pseudoepiphyses were well formed by 4-5 years and coalesced with the rest of the bone months to years before skeletal maturation was attained at the opposite epiphyseal end.

Ossification and pseudoepiphysis formation in the "nonepiphyseal" end of bones of the hands and feet.

Metacarpals, metatarsals, and phalanges were studied to assess the developmental morphology of "secondary" ossification in the "nonepiphyseal" ends of these bones as well as the formation of the pseudoepiphysis as an epiphyseal ossification variant. Both direct ossification extension from the metaphysis into the epiphysis and pseudoepiphysis formation preceded, and continued to be more mature than, formation and expansion of the "classic" epiphyseal (secondary) ossification center at the opposite end of each specific bone. Direct metaphyseal to epiphyseal ossification usually started centrally and expanded hemispherically, replacing both physeal and epiphyseal cartilage simultaneously. In contrast, when remnants of "physis" were retained, while juxtaposed epiphyseal cartilage was replaced, a pseudoepiphysis formed. There were three basic patterns of pseudoepiphysis formation. First, a central osseous bridge extended from the metaphysis across the "physis" into the epiphysis and subsequently expanded to create a mushroom-like osseous structure. In the second pattern a peripheral osseous bridge formed, creating either an osseous ring or an eccentric bridge between the metaphysis and the epiphysis. In the third pattern, multiple bridging occurred. In each situation the associated remnant "physis" lacked typical cell columns and was incapable of significantly contributing to the postnatal longitudinal growth of the involved bone. Pseudoepiphyses were well formed by 4-5 years and coalesced with the rest of the bone months of years before skeletal maturation was attained at the opposite epiphyseal end, which ossified in the typical pattern (i.e., formation of a secondary center de novo completely within the cartilaginous epiphysis). This process may also affect the development and appearance of ossification within the longitudinal epiphyseal bracket ("delta phalanx").

Concomitant skeletal and soft tissue injuries.

The diagnosis and treatment of those injuries most commonly seen in conjunction with distal radius fractures are reviewed in this article. Concomitant tendon, arterial, and nerve injuries often are associated with a high-energy mechanism of trauma. These injuries may complicate an already difficult fracture care plan, especially if the diagnosis of these injuries is delayed. Late tendon rupture and intercarpal injuries are discussed also.

Computed analyses of the pathomechanics of scaphoid waist nonunions.

The computed tomography scans of both the injured and the normal wrists of nine patients with a scaphoid nonunion of 5 to 120 months' duration were used to create three-dimensional computer models. When the computer images of the normal and the contralateral fractured scaphoids were superimposed, it was possible to calculate the volume of bone that was lost as a result of the injury and its failure to heal, as well as the angular relationship of the fracture components to one another. The amount of the scaphoid bone that was lost varied from 6% to 15% of bone volume and did not show a linear correlation with the duration of the nonunion. The configuration of the missing bone was consistent and exhibited a prismatic shape whose base is quadrilateral and faces palmarly. The proximal scaphoid fracture component is extended, radially deviated, and supinated in relation to its distal fracture component. The consistent fracture deformity and the configuration of the bony defect in the scaphoid waist nonunions should be helpful in the understanding and treatment of the condition.

Distal ulnar physeal injury.

We reviewed 18 patients and two traumatic amputation specimens with injuries involving the distal ulnar physis. Type 1 growth mechanism injuries were the most common fracture pattern with premature physeal closure and ulnar shortening occurring in 55% of the patients. Other consequences included radial bowing, ulnar angulation of the distal radius, and ulnar translocation of the carpus. Most of the patients, however, were asymptomatic. Initial radiographic diagnosis of this physeal injury may be difficult because of the relatively late ossification of the distal ulnar physis. Concomitant ulnar physeal injuries must be suspected in any injury to the distal radius, especially when an ulnar metaphyseal or styloid fracture is not readily evident.

Carpal orientation from computed reference axes.

Carpal instability is usually diagnosed by abnormal two-plane radiographic angles. These angles are often unreliable. A method that eliminates interpretation of overlapping shadows and uses all of the carpal geometry should improve clinical diagnoses. The digital data from computed tomography scans can be manipulated to describe the carpal orientation in the normal wrist. The digital data from the computed tomography scans of twenty-two normal wrists were used to compute distances with and without directions between the volumetric centroids of the carpal bones. An expansion technique also extracted from the computed tomography data an orthogonal set of vectors, the principal axes. The first principal axis describes the longest dimension of each bone. The average angle produced by the first principal axes of the scaphoid and lunate was 23.6 degrees, scaphoid and capitate was 73.2 degrees, and the capitate and the lunate was 93.5 degrees. These computations represent new carpal axes and intercarpal angles that are not related to the commonly measured two-plane radiographic angles. They should prove helpful in the study of kinematics and pathomechanics in the wrist joint.

Wrist and hand skeletal injuries in children.

When accidents occur, the hand is the part of the body most often thrust out to lessen the consequences, resulting in a wide array of combinations of soft-tissue and chondro-osseous injuries. Pediatric wrist and hand skeletal injuries discussed in this article include growth mechanism injury, fractures and dislocations, nailbed injuries, fingertip injuries, burns, and frostbite.

Digital subtraction arthrography of the wrist.

Digital subtraction arthrography of the wrist was used to identify abnormalities in eighty-six (60 per cent) of 139 patients during a fifteen-month period. Multiple abnormalities were noted in thirty-four (25 per cent) of the wrists. The clinical signs and symptoms in the eighty-six wrists did not always correlate with the defects that were seen on the arthrograms. Three of five patients who had an isolated tear of the scapholunate ligament, six of thirteen who had an isolated tear of the lunotriquetral ligament, and seven of nineteen who had an isolated tear of the triangular fibrocartilage complex also had signs and symptoms on the opposite side of the wrist. Many of the lesions that were seen on arthrography may have been serendipitous, degenerative, or unrelated to a specific injury. There was a high prevalence of positive ulnar variance in patients who had at least one ulnar abnormality. Capsular tears, most often seen on the radiovolar aspect of the wrist, were best outlined by contrast medium injected into the radiocarpal joint. The arthroscopic findings differed from the arthrographic findings in five of the twenty patients in whom both studies were done. The three-compartment technique of injection is a valuable diagnostic tool. Injections of contrast medium into the distal radio-ulnar joint outlined five of thirteen tears of the triangular fibrocartilage complex that were not seen after injection into the radiocarpal joint. Of the eleven tears that were seen after injection into the radiocarpal joint, five were not seen when contrast medium was injected into the distal radio-ulnar joint.

Composite wiring of metacarpal and phalangeal fractures.

Composite wiring techniques using various configurations of Kirschner pins and stainless steel wire sutures have been applied to the treatment of 63 fractures of the long bones of the hand. The secure fixation achieved allowed active motion within 1 week of operation. Thirty-three metacarpal fractures achieved a final mean total active motion of 256 degrees (standard deviation 13.4) (normal total active motion -260 degrees). Twenty-one phalangeal fractures achieved a mean total active motion of 215 degrees (standard deviation, 46 degrees). There were no instances of infection, malunion, nonunion, loss of reduction, or tendon rupture in the 63 fractures that were treated.

Advanced imaging of the wrist.

In an effort to improve the radiologist's contribution to the evaluation of the painful wrist, the authors have studied the usefulness of a variety of imaging techniques. Preliminary results of these studies, including: 173 conventional CT, 80 3-D CT, 119 postarthrography CT, 138 multiple compartment digital subtraction arthrography and 55 MRI examinations, are reported, and technical aspects of the examinations are described.

Transulnar percutaneous pinning of displaced distal radial fractures: a preliminary report.

Difficulty in maintaining the reduction of displaced radial fractures has prompted the use of numerous techniques to address this problem. The purpose of this study was to determine if four or five 0.045-in Kirschner pins when placed percutaneously through the ulna into the radius could maintain the reduction of this unstable fracture configuration. A 15-month average follow-up of 14 patients, averaging 48 years old, included subjective patient responses and range-of-motion measurements of the forearm, wrist, and digits in addition to grip strength determinations. Analyses of the radial angle and radial height were made on the posteroanterior radiograph, and the articular inclination was assessed on the lateral radiograph. Overall results were 2 excellent and 12 good using the Scheck demerit system of evaluation. The advantages of this technique are as follows: Radial sensory nerves are avoided; use of a lightweight splint at 3 weeks promotes patient comfort and facilitates finger range-of motion exercises; percutaneous pins are easily removed in the office without anesthesia; and pin site scars are barely perceptible at follow-up in the majority of patients.

CT of the wrist for the evaluation of traumatic injuries.

Computed tomography (CT) of the wrist can help evaluate many types of posttraumatic injuries, particularly bony trauma. Most wrist fractures can be diagnosed with routine radiography, but problematic cases and complicated healing fractures can be difficult to evaluate with conventional radiography. CT provides improved contrast resolution and multiplanar imaging. The results of complex healing fractures and fusion procedures can be facilitated with CT. Even in the face of advanced osteoporosis CT can delineate bone edges and detect small areas of bony fusion. The degree of bone graft assimilation can be determined with CT. Unlike conventional radiography, metal fixation pins and cast material do not obviate diagnostic exams with CT. Certain posttraumatic complications such as distal radioulnar joint incongruity and hypertrophy of Lister's tubercle can be detected with axial CT images. Complicated cases of retained foreign bodies can be evaluated with CT. The high-contrast resolution of CT allows precise localization of foreign bodies and can define anatomic relationships to adjacent vital structures such as joints, tendons, and carpal tunnel. Postarthrography CT of the wrist is an investigational tool that permits direct visualization of the triangular fibrocartilage complex (TFCC). Complete and partial tears of the TFCC can be evaluated with postarthrography CT. Ulnar capsular tears and disruptions of interosseous ligaments can also be evaluated with this technique. The exact role of postarthrography CT of the wrist, however, is uncertain at this point. Three-dimensional CT is receiving increasing interest and may eventually help the understanding of wrist pathomechanics and kinematics. In summary, CT of the wrist can be instrumental in evaluating complicated posttraumatic injuries of the wrist and has certain advantages over routine radiography.

Mathematical analysis of computed carpal models.

The computed carpal models from digital computed tomography (CT) data obtained in this study compare favorably to natural anatomy. A new application of algebraic analysis of this data provides mathematical markers from which to calculate the position and orientation of each carpal bone. When the origin of the spatial coordinates of a carpal bone is transferred to the centroid of the bone, the data can be treated as three-dimensional pattern vectors describing its surface. It is then possible to calculate vectors that are the principal axes of the geometry. These axes provided references that were used to calculate position and orientation of the carpal bones in three wrist specimens. Comparisons of volumes, surface areas, and sizes and proportions of five computed images of each carpal bone from two of these wrists demonstrate the reliability of the technique. The analysis of CT scans of ceramics with known boundaries allows an estimation of its accuracy. The technique is well suited to the future study of normal wrist kinematics and pathological conditions.

Treatment of unstable metacarpal and phalangeal fractures with tension band wiring techniques.

The techniques of tension band fixation are applied in the treatment of metacarpal and phalangeal fractures. The technique uses standard, readily available materials. The variability of the fixation techniques allows for secure fixation of virtually any long bone fracture in the hand, even when other methods are not applicable. Nonunion, malunion, loss of fixation, infection, or tendon rupture have not occurred. The technique allows for early active motion and return to full activity usually within for to six weeks. Most patients achieve full painless motion in that time.

Scaphoid orientation and location from computed, three-dimensional carpal models.

Subtle subluxations within the carpus are often difficult to diagnose. Carpal orientation and location can now be quantified by mathematical analysis of computed, three-dimensional models produced from serial CT scans. The technique and its application in the analysis of scaphoid subluxation are described.

Radiography of the wrist.

The painful wrist frequently poses a diagnostic dilemma. Although increased understanding of normal carpal motion has led to more constructive use of roentgenography, the diagnostic acumen of the examiner is greatly enhanced by the standardization of radiographic views as well as by the use of special projections and when indicated, arthrograms.

Carpal tunnel release: analysis of suboptimal results.

The results of carpal tunnel release are generally good, but not all patients obtain complete and long lasting relief. Persistence of signs and symptoms after adequate decompression of the median nerve is uncommon. Forty-seven suboptimal results in thirty-four patients have been evaluated to determine the reasons for failure. Thirty-eight of the suboptimal results (81%) were associated with the persistent neck pain and/or abnormal cervical radiographs (typically narrowing of C5-6 and/or C6-7 disc spaces). This retrospective review supports a "double crush" phenomenon that influences both the manifestations of carpal tunnel syndrome and the outcome of its treatment.