Narrative Review of Ligamentous Wrist Injuries

Ligamentous wrist injuries are common occurrences that require complex anatomical mastery and extensive understanding of diagnostic and treatment modalities. The purpose of this educational review article is to delve into the most clinically relevant wrist ligaments in an organized manner to provide the reader with an overview of relevant anatomy, function, clinical examination findings, imaging modalities, and options for management. Emphasis is placed on elucidating reported diagnostic accuracies and treatment outcomes to encourage evidence-based practice.     

Proximal-distal shift of the center of rotation in a total wrist arthroplasty is more than twice of the healthy wrist

Reproduction of healthy wrist biomechanics should minimize the abnormal joint forces that could potentially result in the failure of a total wrist arthroplasty (TWA). To date, the in vivo kinematics of TWA have not been measured and it is unknown if TWA preserves healthy wrist kinematics. Therefore, the purpose of this in vivo study was to determine the center of rotation (COR) for a current TWA design and to compare its location to the healthy wrist. The wrist COR for six patients with TWA and 10 healthy subjects were calculated using biplane videoradiography as the subjects performed various range-of-motion and functional tasks that included coupled wrist motions. An open-source registration software, Autoscoper, was used for model-based tracking and kinematics analysis. It was demonstrated that the COR was located near the centers of curvatures of the carpal component for the anatomical motions of flexion-extension and radial-ulnar deviation. When compared to healthy wrists, the COR of TWAs was located more distal in both pure radial deviation (P < .0001) and pure ulnar deviation (P = .07), while there was no difference in its location in pure flexion or extension (P = .99). Across all coupled motions, the TWA's COR shifted more than two times that of the healthy wrists in the proximal-distal direction (17.1 vs 7.2 mm). We postulate that the mismatch in the COR location and behavior may be associated with increased loading of the TWA components, leading to an increase in the risk of component and/or interface failure.     

Effect of static wrist position on grip strength

Background:

Grip strength after wrist arthrodesis is reported to be significantly less than normal. One of the reasons suggested for this decrease in grip strength is that the arthrodesis was performed in a suboptimal position. However, there is no consensus on the ideal position of wrist fusion. There is a paucity of studies evaluating the effect of various fixed positions of the wrist on grip strength and therefore, there is no guide regarding the ideal position of wrist fusion. The authors′ aim was to determine the grip strength in various fixed positions of the wrist and subsequently to find out in which position of wrist fusion the grip strength would be maximal.

Materials and Methods:

One hundred healthy adults participated in the study. For the purpose of this study, the authors constructed splints to hold the wrist in five different fixed positions: 45, 30 and 15 degrees of wrist extension, neutral and 30 degrees of wrist flexion. The grip strength in all the participants was measured bilaterally, first without a splint and then with each splint sequentially.

Results:

The average grip strength without the splint was 34.3 kg for right and 32.3 kg for the left hand. Grip strength decreased by 19–25% when the wrist was splinted. The maximum average grip strength with a splint on was recorded at 45 degrees of extension (27.9 kg for right and 26.3 kg for left side). There was a gradual increase in the grip strength with increase in wrist extension but the difference was not statistically significant (P = 0.29). The grip strength was significantly less in flexed position of the wrist (P < 0.001).     

Wrist arthrodesis using a Synthes wrist fusion plate

Thirty-nine patients were retrospectively reviewed after a wrist arthrodesis using a Synthes wrist fusion plate and iliac crest bone graft. Information was obtained from review of patient files, a questionnaire to assess pain, function and work status, and clinical assessment of grip strength, forearm rotation and fingers motion. All wrist fusions united except that the index carpometacarpal joint failed to unite in one patient. Thirty-seven patients were satisfied with the procedure, noting a reduction in wrist pain after fusion, but all reported some limitation of function. The wrist fusion plate was removed in six patients and a further four patients experienced minor symptoms over the dorsal aspect of the middle finger metacarpal.     

Risk Factors for Infection Following Total Wrist Arthroplasty and Arthrodesis: An Analysis of 6641 Patients

Background: Infection following wrist arthroplasty (WA) or wrist fusion (WF) is an uncommon but difficult complication often resulting in explantation and prolonged courses of antibiotics. The purposes of this study are to: (1) characterize the demographic trends of individuals undergoing WA and WF; (2) determine the incidence of postoperative infection; and (3) identify risk factors for postoperative infection. Methods: The PearlDiver database was used to query 100% Medicare Standard Analytic files from 2005 to 2014. Patients undergoing WA or radiocarpal WF were identified using Current Procedural Terminology (CPT) codes. Diagnosis for infection within 1 year of operative intervention was assessed by International Classification of Diseases, Ninth Revision codes or CPT codes related to infection. Multivariable logistic regression analyses were performed to evaluate the risk factors for postoperative infection. Results: Of the 6641 patients included, 1137 (17.1%) underwent arthroplasty and 5504 (82.9%) underwent arthrodesis. Within 1 year of the index procedure, 3.5% had a diagnosis of, or procedure for, postoperative infection (WA: n = 40 of 1137; WF: n = 192 of 5504). Risk factors for infection following WA include age >85, tobacco use, depression, diabetes mellitus, and chronic kidney disease. Risk factors following radiocarpal WF include male sex, age >85, body mass index <19 kg/m², depression, diabetes mellitus, and chronic kidney disease. Posttraumatic origin of wrist arthritis was a risk factor for infection following both WA and WF. Conclusions: Infection following WA and WF is relatively uncommon in a nationally representative Medicare database cohort. Risk factors common to both WA and WF include age >85, depression, diabetes mellitus, chronic kidney disease, and posttraumatic arthritis.     

Bare bones: Fundamentals of diagnostic wrist arthroscopy

Diagnostic wrist arthroscopy is an essential component of the modern orthopaedic wrist surgeon's skill set. Fundamental elements of diagnostic wrist arthroscopy include pre-operative planning and consent, operative set up, surface anatomy, a systematic approach and applied clinical anatomy, and closure. These fundamentals are described, including options and preferences for implementation. A sound understanding of these elements is key to lay the foundations for successful clinical procedures.