Midcarpal Instability: A Historical and Etymological Review.

Although midcarpal instability was first described almost 45 years ago, this uncommon condition is still poorly understood by most clinicians today. Adding to the confusion, it is known by 2 different names: midcarpal instability and carpal instability nondissociative. In this article, we describe the history of the recognition of instability of the midcarpal joint, including its pathomechanics, classification, and treatment. We hope that a more complete understanding of the etymology and kinematics of the disorder will facilitate its future recognition and assist in appropriate treatment decision making.

Precision Medicine for Kienböck Disease in the 21st Century.

One of the most popular treatment algorithms for Kienböck disease is based on a progression of successive radiographic changes that was developed in the 1970s. Since then, 2 other important classifications systems have been introduced. One is centered on contrasted magnetic resonance imaging findings and the other, articular cartilage degeneration. All 3 systems have been used, in isolation, to recommend specific treatment modalities. To coordinate all available clinical data and to simplify the treatment selection process, we combined the 3 classification systems into 1 unified classification and treatment algorithm. With the added consideration of some recently introduced surgical options and further knowledge of how Kienböck disease affects children and the elderly, we anticipate that this unified classification system will allow for a more precise and individualized treatment plan.

The Role of Wrist Arthroscopy in Kienbock Disease.

Kienbock disease (KD) is a disease of uncertain etiology, leading to chondral and osseous change in the lunate and wrist. Traditionally, Lichtman's classification of KD, based on radiographic appearances, has been used to direct treatment. Diagnostic wrist arthroscopy allows direct assessment of the lunate and surrounding articulations. Wrist arthroscopy can also serve as a therapeutic tool for performing debridement, resection, or arthrodesis procedures. The new Lichtman-Bain algorithm takes into consideration the status of the lunate, the effect on the wrist, and surgical and patient factors to guide management.

Kienböck Disease: A New Algorithm for the 21st Century.

Background It has been over 100 years since the initial description of avascular necrosis of the lunate. Over the last two decades, there has been the introduction of advanced information regarding the etiology, natural history, classification, and treatment options for lunate osteonecrosis. There have been new classifications developed based on advanced imaging, perfusion studies of lunate viability, and arthroscopic assessment of the articular cartilage. Purpose This article brings together a new treatment algorithm, incorporating the traditional osseous classification system (Lichtman) with the perfusion/viability classification (Schmitt) and the articular cartilage classification (Bain). Methods We have developed a new algorithm to manage Kienböck avascular necrosis of the lunate. This new algorithm incorporates the current concepts of the diseased lunate and its effects on the remainder of the wrist. Conclusion For patients with a good prognosis and in the earliest stages, the "intact lunate" is initially protected utilizing nonoperative measures. If this fails, then appropriate lunate unloading procedures should be considered. If the lunate is "compromised" then it can be reconstructed with a medial femoral condyle graft or proximal row carpectomy (PRC). With the further collapse of the lunate, the wrist is then also compromised, with the development of secondary degeneration of the central column articulation. The "compromised wrist" will have functional articulations, which allows motion-preserving procedures to be utilized to maintain a functional wrist. With advanced disease (Kienböck disease advanced collapse), the wrist is not reconstructable, so only a salvage procedure can be performed. Other than these objective pathoanatomical factors, the final decision must accommodate the various patient factors (e.g., age, general health, lifestyle, financial constraints, and future demands on the wrist) and surgeon factors (skill set, equipment, and work environment).

Erratum: Addendum: Kienböck Disease: A New Algorithm for the 21st Century.

[This corrects the article DOI: 10.1055/s-0036-1593734.].

The Etiology and Pathogenesis of Kienböck Disease.

Kienböck disease is a condition that typically occurs in the "at-risk" patient, in the "at-risk" aspect of the proximal condyle of the "at-risk" lunate. In the active male, repetitive loading causes the stress fracture that commences in the single layer proximal subchondral bone plate. The lunate fracture commences at the point the lunate cantilevers over the edge of the distal radius, and then takes on the shape of the radius. We postulate that the stress fracture violates the parallel veins of the venous subarticular plexus-leading to localized venous hypertension and subsequent ischemia and edema of the fatty marrow. The increased osseous compartment pressure further potentiates the venous obstruction, producing avascular necrosis. If the fracture remains localized, it can heal or settle into a stable configuration, so that the wrist remains functional. Fractures of the subchondral bone plate produce irregularity of the lunate articular surfaces and secondary "kissing lesions" of the lunate facet and capitate, and subsequent degeneration. The lunate collapses when the fracture is comminuted, or there is disruption of the spanning trabeculae or a coronal fracture. The secondary effect of the lunate collapse is proximal migration of the capitate between the volar and dorsal fragments, producing collapse of the entire central column. The proximal carpal row is now unstable, and is similar to scapholunate instability, where the capitate migrates between the scaphoid and lunate. The scaphoid is forced into flexion by the trapezium, however, degeneration of the scaphoid and scaphoid facet only occurs in late disease or following failed surgery. In Kienböck disease, the secondary effects of the collapsing lunate are a "compromised" wrist, including: deformity and collapse of the central column, degeneration of the central column (perilunate) articulations, proximal row instability (i.e., between the central and radial columns), and degeneration of the radial column.

Kienböck Disease and Arthroscopy: Assessment, Classification, and Treatment.

The assessment and management of Kienböck Disease (KD) has always been a conundrum. The Lichtman classification has traditionally been used to guide treatment based on imaging. Arthroscopy provides a direct visualization of the articular surface, allows probing of the surfaces, and enables minimally invasive techniques to be performed. The Lichtman-Bain classification is a new classification that takes into account the osseous, vascular, and cartilage aspects of the lunate and the secondary effects on the wrist. It identifies the important prognostic factors including age, the status of the lunate, and the status of the wrist. With arthroscopy, the articular surfaces of the lunate can be assessed to better understand the status of the lunate. The lunate can be defined as intact, compromised, or not reconstructable. If the lunate is intact then lunate decompression (forage) and arthroscopic assisted bone grafting can be performed. If the lunate facet and capitate are functional, then a proximal carpectomy can be performed. This can be performed as an arthroscopic procedure. Assessment of the wrist includes assessment of the adjacent articular surfaces of the central column articulations (radiocarpal and midcarpal articulations). Instability of the proximal carpal row can also be assessed. The radioscaphoid articulation is often preserved except in late KD, which allows the scaphocapitate fusion to be a good surgical option. This can now be performed as an arthroscopic procedure. Once the radioscaphoid articulation is degenerate, a salvage procedure is required.

Erratum: The Etiology and Pathogenesis of Kienböck Disease.

[This corrects the article DOI: 10.1055/s-0036-1583755.].

Kienböck Disease: Moving Forward.

Over the past decade, a plethora of new information has been reported regarding etiology, natural history, classification, and treatment options for lunate osteonecrosis. New disease classifications have been described based on advanced imaging determination of lunate viability as well as a cartilage-based arthroscopic classification. Here we review the newest literature regarding Kienböck disease and present a new treatment algorithm that incorporates the traditional osseous classification system with a perfusion/viability classification and an articular cartilage-based classification.

Midcarpal Instability: A Comprehensive Review and Update.

Midcarpal instability has been well described as a clinical entity but the pathokinematics and pathologic anatomy continue to be poorly understood. This article presents a comprehensive review of the existing knowledge and literature-based evidence for the diagnosis and management of the various entities comprising midcarpal instability. It discusses the limitations of the current understanding of midcarpal instability and proposes new directions for furthering knowledge of the causes and treatment of midcarpal instability and wrist pathomechanics in general.

Surgical Techniques for the Management of Midcarpal Instability.

Palmar midcarpal instability (PMCI) is an uncommon and poorly understood disorder. Its etiology is believed to be due to traumatic or congenital laxity of the ligaments (volar and dorsal) that stabilize the proximal row. This laxity results in hypermobility of the proximal carpal row and unphysiologic coupling of the midcarpal joint. Clinically, the condition is manifested by a painful clunk with ulnar and radial wrist deviation. The purpose of this article is to chronicle our personal experience with this condition and to review our current treatment recommendations and outcomes.

Current issues in the physician-patient relationship.

This review is one of a series of articles reflecting the sections of the Code of Ethics of the American Society for Surgery of the Hand. The physician-patient relationship has been subjected to numerous stressors over the past several decades. This report reviews historical elements of the relationship and discusses current issues related to it: asymmetry, challenges to the physician, and interpersonal, systemic, and societal challenges.

Treatment of distal radius fractures.

The clinical practice guideline is based on a systematic review of published studies on the treatment of distal radius fractures in adults. None of the 29 recommendations made by the work group was graded as strong; most are graded as inconclusive or consensus; seven are graded as weak. The remaining five moderate-strength recommendations include surgical fixation, rather than cast fixation, for fractures with postreduction radial shortening >3 mm, dorsal tilt >10 degrees , or intra-articular displacement or step-off >2 mm; use of rigid immobilization rather than removable splints for nonsurgical treatment; making a postreduction true lateral radiograph of the carpus to assess dorsal radial ulnar joint alignment; beginning early wrist motion following stable fixation; and recommending adjuvant treatment with vitamin C to prevent disproportionate pain.

Lunate revascularization with artery implantation and bone grafting.

Treatment of Kienböck's disease encompasses a wide array of options. Proper staging is the first step to successful treatment. Revascularization of the lunate remains a viable option for the treatment of Lichtman stage II or IIIA Kienböck's disease. In this article, we review the indications for and the surgical technique used with a modified Hori procedure (vascular pedicle insertion with structural distal radius graft) for revascularization of the lunate.

Risk factors in total joint arthroplasty: comparison of infection rates in patients with different socioeconomic backgrounds.

Infection after total joint arthroplasty is a serious complication. Several risk factors have been shown to increase the risk of total joint infections. The purpose of this study was to evaluate whether socioeconomic background was a risk factor for infection in primary total joint arthroplasty. A retrospective chart review was conducted over a 4-year period on a single surgeon's split practice between private patients with mostly private insurance and Medicare and county based patients with predominately indigent county health coverage and Medicaid. An infection rate was calculated for each population in both primary total knee and hip arthroplasty. The two populations were statistically analyzed for differences in age, preoperative diagnoses, and socioeconomic background. To our knowledge, this is the first study showing an increased risk of infection in total joint arthroplasty based on socioeconomic background.

Understanding midcarpal instability.

This article outlines the historical development of midcarpal instability observations and terminology and places them in the broader context of currently accepted theories of wrist pathomechanics. Such an understanding may help resolve the following questions: Are there 1 or more entities under the current designation of midcarpal instability? What are the underlying pathogenesis and pathomechanics of the disorder(s)? What are the recommended treatment options? What further research needs to be done to better answer these questions?