The sequence of the Mycoplasma arthritidis superantigen, MAM: identification of functional domains and comparison with microbial superantigens and plant lectin mitogens.

Mycoplasma arthritidis, an agent of chronic proliferative arthritis of rodents, secretes a potent soluble superantigen, MAM, that is active for both murine and human T and B lymphocytes. We now report the complete nucleotide and amino acid sequence of MAM and show it to be distinct from other proteins and not closely related phylogenetically to other superantigens. Two functional domains on MAM are identified based on the ability of peptides encompassing these regions to inhibit lymphocyte proliferation by the intact MAM molecule. One of these domains shares short sequences or epitopes with other microbial superantigens. The second domain contains the consensus legume lectin motif-beta, which is important for T cell activation by concanavalin (Con) A. MAM and Con A peptides containing this motif are functionally cross reactive, suggesting a novel secondary pathway for T cell activation by MAM.

Eponyms in orthopaedics.

Eponym (epó-nim) [Greek eponymos, named after] The name of a disease, structure, operation, or procedure, derived from the name of the person who discovered or described it first. Argot (ärgõ) [French origin "in thieves' jargon"] The specialized vocabulary and idioms of those in the same work. Eponyms are commonly used in orthopaedics. Yet the individual's name and history often remain obscure or unknown to the user. The recognition and appropriate use of the eponymic terms become more difficult as the terminology falls into disuse. It is hoped that this report will serve as a reference and a resource and will preserve orthopaedic history.

Dupuytren's contracture.

Dupuytren's contracture is a fibroproliferative disorder of autosomal dominant inheritance that most commonly affects men over age 60 who are of Scandinavian, Irish, or eastern European descent. Local microvessel ischemia in the hand and specific platelet-derived and fibroblast growth factors act at the cellular level to promote the dense myofibroblast population and altered collagen profiles seen in affected tissue. Surgical treatment depends to some degree on patient preference and a clear understanding of the possible complications and considerable postoperative therapy commitment. Operative management is appropriate when metacarpophalangeal or proximal interphalangeal joint contracture exceeds 30 degrees. A volar zigzag Brunner incision in the digit and palm provides reliable exposure and leads to predictable healing in most cases. The mainstay of postoperative hand therapy is early active-flexion range-of-motion exercises to restore grip strength. A nighttime extension splint is often used for several months postoperatively to maintain the correction achieved in the operating room. Early recurrence of disease is most common in individuals with Dupuytren's diathesis; use of full-thickness skin grafts may be helped for these patients.

Forearm compartment syndrome due to automated injection of computed tomography contrast material.

Automated injection of computed tomography contrast material can produce a compartment syndrome if extravasation occurs. Unconscious patients and the elderly may be at particular risk. Selection of nonionic contrast material, careful evaluation of the intravenous administration site, and close monitoring of the patient during use of a power injector may help minimize or prevent extravasation injuries.

Myositis ossificans after a supracondylar fracture of the humerus in a child.

Myositis Ossificans After a Supracondylar Fracture of the Humerus in a Child. In addition to the better known complications of supracondylar humerus fractures, myositis ossificans is often listed as a less common complication. This complication is extremely rare in children and historically has been attributed to high-energy trauma, manipulation, surgical intervention, aggressive passive range-of-motion exercises, or associated head injury. We present a case report of a 3-year-old girl who developed myositis ossificans after a low-energy supracondylar fracture of the humerus despite having been treated without manipulation, surgery, or physical therapy. This report illustrates that supracondylar humerus fractures can be complicated by myositis ossificans despite the best attempts at prevention.

Proximal interphalangeal joint injuries of the hand. Part II: Treatment and complications.

This is the second of a two-part series reviewing injuries to the proximal interphalangeal (PIP) joint of the hand. In part one, we reviewed the normal anatomy, classification, diagnosis, and pathoanatomy of the various injuries. In this article, we focus on the treatment options and complications associated with each of the injury types. Aggressive, early range of motion in a supervised therapy program is emphasized as the mainstay of treatment.

Coronal fracture of the hamate body.

A case of a displaced coronal fracture of the hamate body with a 1-month delay in diagnosis is presented with a review of the literature regarding hamate-body fractures. Mechanism, diagnosis, and treatment options are discussed. This diagnosis should be suspected on initial review of plain radiographs, which must include an oblique view in any patient presenting with pain after blunt trauma to the hand. Open reduction with internal fixation is reserved for unstable, displaced fractures. Care should be taken to preserve the vascular supply to the displaced fragment, and a two-incision technique is recommended to minimize risk to the motor branch of the ulnar nerve.

Proximal interphalangeal joint injuries of the hand. Part I: anatomy and diagnosis.

Injury to the proximal interphalangeal (PIP) joint is one of the most common hand injuries encountered by orthopedic surgeons. The injuries are often misdiagnosed, resulting in delayed treatment and permanent impairment. The different types of PIP-joint fractures and dislocations have been well described, and a variety of therapeutic options have been proposed. Early detection and aggressive rehabilitation are the cornerstones of successful treatment. This is the first of a two-part series reviewing PIP injuries. We describe the anatomy and biomechanics of the PIP joint and review the classification and diagnosis of these injuries.

Wrist arthroscopy: indications and results.

The results of 84 wrist arthroscopies in 74 patients (performed by the same surgeon) were reviewed retrospectively. Arthroscopies were categorized as "diagnostic"--to identify unknown pathology, "staging"--to assess the severity of known pathology, and "operative"--to treat known pathology. Ninety-eight percent of diagnostic arthroscopies accurately established details of the pathology in question. Ninety-six percent of staging arthroscopies helped guide future clinical management. Of the patients in the operative category, 35% improved after treatment with arthroscopy alone, requiring no further surgical intervention. This study shows that wrist arthroscopy is a powerful diagnostic and staging tool and suggests that it may also develop into a valuable treatment modality.

Dislocation of the distal phalanx epiphysis in toddlers.

Two cases of physeal fracture dislocation of the distal phalanx are reviewed. Each injury occurred in a toddler, was originally undiagnosed, and appeared years later as a dorsal mass in a fore-shortened digit with decreased distal interphalangeal joint motion. In each case x-ray films revealed a dislocated epiphysis, accounting for the enlarging dorsal prominence and the phalangeal growth disturbance. These cases demonstrate that dislocation of the distal phalanx epiphysis can occur with a crush injury and may be difficult to detect before development of the ossification center. Careful physical examination and a high index of suspicion will increase the likelihood of early diagnosis. Early open reduction may prevent the late complications of deformity and stiffness.

Injection versus surgery in the treatment of trigger finger.

One hundred nine trigger fingers in 102 patients were reviewed with respect to management plan and response to treatment. Thirty-four digits eventually underwent surgical release of the A1 pulley, while the other 75 digits were treated with local steroid injection only. All patients were evaluated with respect to clinical resolution of symptoms, dollar cost of treatment, and general satisfaction as measured with a post-treatment questionnaire. These data suggest that surgical management may be the next best option in patients with trigger finger who continue to be symptomatic after a single injection. Although surgical release of the A1 pulley cost our Medicare patients $250.00 more than a second injection, this additional cost may be offset by the benefit conferred through permanency of relief. Subjective data from the patient questionnaire responses also support surgery as a reasonable choice after one injection failure. The information from this study better delineates differences between injection and surgery as treatment choices and may aid the patient and physician in choosing an individually optimal care plan.

Camptodactyly: classification and results of nonoperative treatment.

To assess the relationship between clinical presentation and response to treatment, we reviewed the management of 59 involved proximal interphalangeal (PIP) joints in 22 patients with camptodactyly at a mean follow-up of 33 months. This population represented 24 cases of isolated infantile camptodactyly (type I), five cases of adolescent camptodactyly (type II), and 30 cases of syndromic camptodactyly (type III). Treatment response was assessed through passive range of motion measurements. Splinting and close adherence to an occupational therapy program were particularly effective for type I digits. We also recommend this approach for type II and type III camptodactyly, although severe deformities and well-established contractures are more common in these patients. We reserve operative intervention for only those patients who fail nonoperative management.

Pediatric hand injuries due to home exercycles.

The clinical presentation and management of 19 children who sustained injuries by stationary exercise bicycles were reviewed retrospectively. These injuries represented 32 traumatized digits with a minimum of 2-year follow-up. The index and long fingers were most commonly involved. Wheel-spoke injuries typically produced repairable nerve and tendon lacerations, and full functional recovery in these cases was common. The chain/sprocket injury involved a crushing mechanism and frequently produced severe injury including amputations that were not salvageable. Stationary exercise bicycles represented a predictable source of severe hand injury in children between the ages of 18 months and 5 years. Adult supervision was not reliable in preventing contact between an operating exercycle and a child's hand. We recommend that children not be allowed access to any stationary exercycle machinery, whether it is in use or not. Safety design considerations should focus on not only shielding the wheel spokes, but also (and perhaps even more important) on enclosing the entire chain axis and gear interface. In addition to these design considerations, public education will be critical in reducing the incidence of injury.