Safety of Releasing the Volar Capsule During Open Treatment of Distal Radius Fractures: An Analysis of the Extrinsic Radiocarpal Ligaments' Contribution to Radiocarpal Stability.

PURPOSE: The contribution of the extrinsic radiocarpal ligaments to carpal stability continues to be studied. Clinically, there is a concern for carpal instability from release of the volar extrinsic ligaments during volar plating of distal radius fractures in which the integrity of the dorsal ligaments may be unknown. The primary hypothesis of this study was that serial sectioning of radiocarpal ligaments would lead to progressive ulnar translation of the carpus. METHODS: We studied the stabilizing roles of the radioscaphocapitate (RSC), short radiolunate (SRL), long radiolunate (LRL), and dorsal radiocarpal (DRC) ligaments. We sequentially sectioned these ligaments in 2 groups of 5 matched pairs and measured the motion of the scaphoid and lunate with the wrist in passive neutral alignment, radial deviation, ulnar deviation, and simulated grip. Displacement of the lunate in the radioulnar plane was used as a surrogate for carpal translation. The groups differed only by the order in which the ligaments were sectioned. RESULTS: In the intact state, the lunate translated ulnarly during simulated grip and radial deviation, whereas radial translation, relative to its position under resting tension, was observed during ulnar deviation. With serial sectioning, the lunate displayed increased ulnar translation in all wrist positions for both groups 1 and 2. The magnitude of ulnar translation exceeded 1 mm after sectioning the LRL plus RSC along with either the DRC or the SRL. CONCLUSIONS: Sectioning of either the DRC or SRL ligaments along with release of the RSC and LRL ligaments leads to notable although minimal (<2 mm) ulnar lunate translation. CLINICAL RELEVANCE: Isolated sectioning of individual radiocarpal ligaments, such as for visualization of the articular surface of the distal radius, leads to minimal ulnar translation. Because prior clinical work found no clinical complications after volar capsule release, it is posited that translation less than 2 mm creates subclinical changes in carpal mechanics.

The Relationship Between the Tensile and the Torsional Properties of the Native Scapholunate Ligament and Carpal Kinematics.

PURPOSE: The purpose of this exploratory study was to examine the relationship between the tensile and the torsional properties of the native scapholunate interosseous ligament (SLIL) and kinematics of the scaphoid and lunate of an intact wrist during passive radioulnar deviation. METHODS: Eight fresh-frozen cadaveric specimens were transected at the elbow joint and loaded into a custom jig. Kinematic data of the scaphoid and lunate were acquired in a simulated resting condition for 3 wrist positions-neutral, 10° radial deviation, and 30° ulnar deviation-using infrared-emitting rigid body trackers. The SLIL bone-ligament-bone complex was then resected and loaded on a materials testing machine. Specimens underwent cyclic torsional and tensile testing and SLIL tensile and torsional laxity were evaluated. Correlations between scaphoid and lunate rotations and SLIL tensile and torsional properties were determined using Pearson correlation coefficients. RESULTS: Ulnar deviation of both the scaphoid and the lunate were found to decrease as the laxity of SLIL in torsion increased. In addition, the ratio of lunate flexion-extension to radial-ulnar deviation was found to increase with increased SLIL torsional rotation. CONCLUSIONS: Our findings support the theory that there is a relationship between scapholunate kinematics and laxity at the level of the interosseous ligaments. CLINICAL RELEVANCE: Laxity and, specifically, the tensile and torsional properties of an individual's native SLIL should guide reconstruction using a graft material that more closely replicates the individual's native SLIL properties.

Therapy Concepts for the Proximal Interphalangeal Joint.

The principles of hand therapy for proximal interphalangeal joint disorders include protecting injured structures, minimizing patient discomfort, and optimizing patient recovery. Comprehension of hand anatomy, the nature of the injury being treated, and the phases of healing are critical when designing a safe and effective hand therapy program. Hand therapists use a combination of orthoses, guided exercises, and modalities to improve edema, sensitivity, range of motion, and function.

Effectiveness of Preoperative Antibiotics in Preventing Surgical Site Infection After Common Soft Tissue Procedures of the Hand.

BACKGROUND: Antibiotic prophylaxis is a common but controversial practice for clean soft tissue procedures of the hand, such as carpal tunnel release or trigger finger release. Previous studies report no substantial reduction in the risk of surgical site infection (SSI) after antibiotic prophylaxis, yet are limited in power by low sample sizes and low overall rates of postoperative infection. QUESTIONS/PURPOSES: Is there evidence that antibiotic prophylaxis decreases the risk of SSI after soft tissue hand surgery when using propensity score matching to control for potential confounding variables such as demographics, procedure type, medication use, existing comorbidities, and postoperative events? METHODS: This retrospective analysis used the Truven Health MarketScan databases, large, multistate commercial insurance claims databases corresponding to inpatient and outpatient services and outpatient drug claims made between January 2007 and December 2014. The database includes records for patients enrolled in health insurance plans from self-insured employers and other private payers. Current Procedural Terminology codes were used to identify patients who underwent carpal tunnel release, trigger finger release, ganglion and retinacular cyst excision, de Quervain's release, or soft tissue mass excision, and to assign patients to one of two cohorts based on whether they had received preoperative antibiotic prophylaxis. We identified 943,741 patients, of whom 426,755 (45%) were excluded after meeting one or more exclusion criteria: 357,500 (38%) did not have 12 months of consecutive insurance enrollment before surgery or 1 month of enrollment after surgery; 60,693 (6%) had concomitant bony, implant, or incision and drainage or débridement procedures; and 94,141 (10%) did not have complete data. In all, our initial cohort consisted of 516,986 patients, among whom 58,201 (11%) received antibiotic prophylaxis. Propensity scores were calculated and used to create cohorts matched on potential risk factors for SSI, including age, procedure type, recent use of steroids and immunosuppressive agents, diabetes, HIV/AIDs, tobacco use, obesity, rheumatoid arthritis, alcohol abuse, malnutrition, history of prior SSI, and local procedure volume. Multivariable logistic regression before and after propensity score matching was used to test whether antibiotic prophylaxis was associated with a decrease in the risk of SSI within 30 days after surgery. RESULTS: After controlling for patient demographics, hand procedure type, medication use, existing comorbidities (eg, diabetes, HIV/AIDs, tobacco use, obesity), and postoperative events through propensity score matching, we found that the risk of postoperative SSI was no different between patients who had received antibiotic prophylaxis and those who had not (odds ratio, 1.03; 95% CI, 0.93-1.13; p = 0.585). CONCLUSIONS: Antibiotic prophylaxis for common soft tissue procedures of the hand is not associated with reduction in postoperative infection risk. While our analysis cannot account for factors that are not captured in the billing process, this study nevertheless provides strong evidence against unnecessary use of antibiotics before these procedures, especially given the difficulty of conducting a randomized prospective study with a sample size large enough to detect the effect of prophylaxis on the low baseline risk of infection. LEVEL OF EVIDENCE: Level III, therapeutic study.

Tensile and Torsional Structural Properties of the Native Scapholunate Ligament.

PURPOSE: The ideal material for reconstruction of the scapholunate interosseous ligament (SLIL) should replicate the mechanical properties of the native SLIL to recreate normal kinematics and prevent posttraumatic arthritis. The purpose of our study was to evaluate the cyclic torsional and tensile properties of the native SLIL and load to failure tensile properties of the dorsal SLIL. METHODS: The SLIL bone complex was resected from 10 fresh-frozen cadavers. The scaphoid and lunate were secured in polymethylmethacrylate and mounted on a test machine that incorporated an x-y stage and universal joint, which permitted translations perpendicular to the rotation/pull axis as well as nonaxial angulations. After a 1 N preload, specimens underwent cyclic torsional testing (±0.45 N m flexion/extension at 0.5 Hz) and tensile testing (1-50 N at 1 Hz) for 500 cycles. Lastly, the dorsal 10 mm of the SLIL was isolated and displaced at 10 mm/min until failure. RESULTS: During intact SLIL cyclic torsional testing, the neutral zone was 29.7° ± 6.6° and the range of rotation 46.6° ± 7.1°. Stiffness in flexion and extension were 0.11 ± 0.02 and 0.12 ± 0.02 N m/deg, respectively. During cyclic tensile testing, the engagement length was 0.2 ± 0.1 mm, the mean stiffness was 276 ± 67 N/mm, and the range of displacement was 0.4 ± 0.1 mm. The dorsal SLIL displayed a 0.3 ± 0.2 mm engagement length, 240 ± 65 N/mm stiffness, peak load of 270 ± 91 N, and displacement at peak load of 1.8 ± 0.3 mm. CONCLUSIONS: We report the torsional properties of the SLIL. Our novel test setup allows for free rotation and translation, which reduces out-of-plane force application. This may explain our observation of greater dorsal SLIL load to failure than previous reports. CLINICAL RELEVANCE: By matching the natural ligament with respect to its tensile and torsional properties, we believe that reconstructions will better restore the natural kinematics of the wrist and lead to improved outcomes. Future clinical studies should aim to investigate this further.

Association of Lunate Morphology With Carpal Instability in Scapholunate Ligament Injury.

BACKGROUND: We examined the relationship between lunate morphology (type 1 without a medial facet; type II with a medial facet) and dorsal intercalated segmental instability (DISI) in patients with scapholunate ligament injuries. We tested the primary null hypothesis that there is no relationship between lunate morphology and development of DISI. Secondary analysis compared the agreement of classifying lunate morphology based on the presence of a medial lunate facet, capitate-to-triquetrum (CT) distance, and magnetic resonance imaging (MRI). METHODS: We performed a retrospective chart review of patients with known scapholunate ligament injuries from 2001 to 2016. Posterior-anterior radiographs and MRI, when available, were evaluated. CT distances were measured as a secondary classification method. DISI and scapholunate instability were determined as radiolunate angle >15° and scapholunate angle >60°, respectively. Differences between groups were determined using chi-square analysis with significance set at P < .05. Agreement between plain radiographs, MRI, and CT distance was calculated using the kappa statistic. RESULTS: Our search found 58 of 417 patients who met inclusion criteria; 41 of 58 had type II and 17 of 58 had type I lunates. There was no significant difference between groups in regard to DISI or scapholunate instability. Subanalysis using MRI alone or correcting any discrepancy between plain film and MRI classification, using MRI as the standard, found no difference between groups in regard to DISI or scapholunate instability. CONCLUSIONS: In patients with scapholunate ligament injuries, there are no differences in the development of DISI or scapholunate instability between patients with type I and type II lunates.

Cyclic and Load to Failure Properties of All-Suture Anchors in Synthetic Acetabular and Glenoid Cancellous Bone.

PURPOSE: To evaluate the cyclic displacement, maximum load to failure, and failure mode of multiple all-suture anchors (ASAs) in 2 different densities of sawbones cancellous bone substitute. METHODS: Anchors tested included the Suturefix Ultra 1.7 mm, JuggerKnot 1.45 mm (No. 1 and No. 2 MaxBraid) and 2.9 mm, Y-Knot Flex 1.3 mm and 1.8 mm, Iconix 1, 2, 25, and 3, Q-Fix 1.8 mm, and Bioraptor 2.3 PK. The Bioraptor served as a non-all-suture-based control. Seven to eleven anchors were tested in both 20 and 30 pounds per cubic foot (pcf) test blocks that were chosen to simulate glenoid and acetabular cancellous bone, respectively. After a 40 N deployment force, anchors were cyclically loaded at 0.5 Hz from 10 to 50 N and then 10 to 100 N for 200 cycles each. Surviving specimens were pulled to failure at 10 mm/s. Displacement, stiffness, maximum load, and failure mode were recorded. Welch t-tests and Welch analysis of variance with Games-Howell post hoc tests were used for statistical analysis. RESULTS: In higher density blocks, 11 of 12 anchors had significantly (P < .05) higher maximum loads to failure, and 8 anchors showed significantly lower post-cyclic displacement. The Q-Fix 1.8 displayed the lowest post-cyclic displacement in both densities (0.1 ± 0.2 mm, mean ± standard deviation, in both densities). All other groups exhibited at least 2.8 mm and 0.6 mm post-cyclic displacement in 20 and 30 pcf, respectively. The Bioraptor did not survive cyclic testing in 20 pcf and had 0.6 ± 0.3 mm post-cyclic displacement in 30 pcf. CONCLUSIONS: ASAs show better fixation in higher density synthetic bone. The cyclic displacement and maximum load of ASAs vary widely depending on anchor design and bone density. Most anchors fail by suture anchor pullout. In general, the Bioraptor 2.3 PK outperformed ASAs in higher density test blocks with mixed results in lower density test blocks. CLINICAL RELEVANCE: ASAs show mixed results compared with a traditional suture anchor. They perform better in higher density bone substitute.

Nuts and bolts: dimensions of commonly utilized screws in upper extremity surgery.

A plethora of screw designs and sizes are available from multiple companies for use in upper extremity surgery. Knowing the dimensions of screws is critical in the treatment of bone of varying dimensions for fractures, osteotomies, or arthrodeses. Although many screws are named by their major thread diameter, this is not always true. Because of this confusing nomenclature and vast number of options, we sought to review the most commonly used screws and codify their dimensions into a readily available article and reference chart. This article highlights the basic dimensions of commonly used headless screws, stand-alone lag screws, non-locking and locking screws for plating, and biocomposite screws. Commonly described treatments using these screws include fixation of elbow, wrist, carpal, metacarpal, and phalangeal fractures and osteotomies, as well as arthrodeses of upper extremity joints. This article and its tables are by no means exhaustive of all commercially available implants. The focus is on the most commonly used implants in the United States as of 2014.