Faculty Bibliography

Background An accessory slip arising from the extensor carpi ulnaris (ECU) tendon that inserts on the fifth metacarpal bone has been identified. We describe the frequency of this accessory slip arising from the ECU tendon and provide both qualitative and quantitative description of the slip via cadaveric examination. Methods Fifty (28 males and 22 females) cadaveric upper extremity specimens were examined after loupe-aided dissection of the dorsoulnar wrist and hand with identification of the ECU tendon. The presence of an accessory slip arising from the ECU tendon was noted. The insertion and morphology of the accessory slip was also described. Results An accessory slip arising from the ECU tendon at the level of the radiocarpal joint was found to insert on the fifth metacarpal bone in 11 (22%) specimens. Nine accessory slips inserted at the base of the fifth metacarpal (Nakashima Type A) and two inserted at the fifth metacarpal head (Nakashima Type C). Mean width of the accessory slip was 1.2 +/- 0.4 mm. No evidence of sexual dimorphism was found regarding the morphology of the accessory slip. Conclusion The current study demonstrates the relative frequency and morphology of the accessory slip arising from the ECU tendon. This variant should be of diagnostic consideration in ailments of the dorsoulnar wrist and hand. Hand surgeons should be aware of this anatomic variant and its potential for clinical manifestation.

BACKGROUND: Total wrist arthroplasty (TWA) provides the requisite range of motion to accomplish activities of daily living, especially for low-demand patients with bilateral wrist arthritis. However, there are no large epidemiologic studies to evaluate nationwide trends of TWA and wrist fusion (WF). QUESTIONS/PURPOSES: To analyze data collected from the National Inpatient Sample (NIS) to compare utilization, demographic, and outcome data among patients undergoing TWA versus total WF. We hypothesized that utilization rates of TWA have significantly increased over the prior decade in the United States. METHODS: NIS data from 2001 to 2010 were reviewed. Procedures were identified by ICD-9-CM codes 81.73 (TWA) and 81.25 (WF). Utilization rates, primary treatment diagnoses, patient demographic and medical comorbidity data, and procedure costs were compared between TWA and WF. RESULTS: There was a decrease in the number of procedures per year for TWA, while the number of WF remained relatively unchanged. There was, however, a transient increase in the frequency of TWA procedures performed from 2005 to 2008, following a decline in 2005. Patients with traumatic arthritis were more likely to receive WF. Rheumatoid patients were more likely to receive TWA. Patients receiving TWA tended to be older, female, be insured by Medicare, have a greater comorbidity burden, and have rheumatologic disease. CONCLUSION: WF was performed nearly four times more frequently than TWA. A trend was demonstrated toward a decreasing number of TWA being implanted, and in patients with more underlying comorbidities. TWA was associated with a higher hospitalization charge, which may be expected given the higher implant costs associated with arthroplasty. LEVEL OF EVIDENCE: Level II, prognostic study.

BACKGROUND: Cardiovascular procedures are common and are trending toward endovascular interventions. With this increase in endovascular procedures, there is also increasing awareness of upper extremity morbidity resulting from treatment. METHODS: Articles indexed within PubMed between the years 1975 and 2015 that discussed such complications were reviewed. RESULTS: Percutaneous radial artery access can lead to nerve ischemia, especially in the setting of an incomplete arterial arch, whereas radial artery harvesting for bypass surgery more commonly causes frank tissue ischemia and radial neuropathy. Transulnar catheterization may cause ischemic hand injuries, while transbrachial angiography has resulted in compartment syndrome. Injuries to the nerves themselves often result from surgical equipment, such as sternal retractors, or from patient positioning leading to compression of the ulnar nerve. For percutaneous radial artery access, the incidence of ischemic injury is as high as 24%, whereas nerve injury is too rare to be estimated. In the setting of radial artery harvesting, ischemic injury is limited to case reports, and radial neuropathy is estimated to occur in as many as 25% of patients at discharge. Open heart surgery is the primary setting in which equipment or patient positioning plays a role, affecting 10% of patients with brachial plexus injuries and 15% with ulnar neuropathies. CONCLUSION: Complications following cardiovascular interventions are varied and are typically associated with specific procedures. Careful preoperative and postoperative assessments of patients may aid in preventing, minimizing, and treating these often undiagnosed complications.

BACKGROUND: The objective of this study was to compare the mechanical performance of 4 different constructs for fixation of oblique scaphoid fractures. METHODS: Twenty-eight synthetic scaphoids underwent an oblique osteotomy along the dorsal sulcus. Each was randomly assigned to fixation by 1 of 4 methods: two 1.5-mm headless compression screws, one 2.2-mm screw, one 3-mm screw, or a 1.5-mm volar variable-angle plate. After fixation, scaphoids were potted at a 45 degrees angle and loaded at the distal pole by a hydraulically driven mechanical testing system plunger until the fixation failed. Excursion and load were measured with a differential transformer and load cell, respectively. From these data, the stiffness, load-to-failure, and maximum displacement of each construct were calculated. RESULTS: The 2.2-mm screw demonstrated the highest stiffness and the two 1.5-mm screws had the lowest. However, there were no significant differences among the fixation methods in terms of stiffness. Both 2.2- and 3-mm screw constructs had significantly higher loads-to-failure than two 1.5-mm screws. The maximum load for the plate approached, but did not achieve, statistical significance compared with the 1.5-mm screws. There was no significant difference among constructs in displacement. CONCLUSIONS: All constructs demonstrated similar mechanical properties that may provide sufficient stability for effective clinical use. Given their significantly higher loads-to-failure, a 2.2- or 3-mm screw may be superior to two 1.5-mm screws for fixation of unstable scaphoid fractures. The volar plate did not have superior mechanical characteristics to the compression screws.

There is growing concern that the readability of online or - thopaedic patient education materials are too difficult for the general public to fully understand. It is recommended that this information be at the sixth grade reading level or lower. This study compared the readability of shoulder and elbow education articles from the American Academy of Orthopaedic Surgeons (AAOS) and American Society for Surgery of the Hand (ASSH) websites. Seventy-six patient education articles from the AAOS and ASSH concerning shoulder and elbow disorders were evaluated. Each article was assessed for the number of years since its last update, word count, percentage of passive sentences, Flesch Reading Ease score, Flesch-Kincaid grade level, Simple Measure of Gobbledygook (SMOG) grade, and New Dale-Chall grade level. Only one article was at or below the sixth grade read - ing level. The AAOS and ASSH articles had the following respective scores: a mean Flesch Reading Ease score of 54.3 and 51.8, Flesch-Kincaid grade level of 9.4 and 10.3, SMOG grade of 8.5 and 9.4, and New Dale-Chall grade of 10.4 and 11.0. Articles from the AAOS were longer (p < 0.001), had a lower percentage of passive sentences (p < 0.001), and were more recently updated (p = 0.02) than their ASSH counterparts. Higher percentages of passive sentences were found to correlate with more difficult read - ability. Patient education materials regarding the shoulder and elbow on the AAOS and ASSH websites have readability scores above the recommended reading level. These may be too challenging for the majority of patients to read and consequently serve as a barrier to proper patient education. Reducing the percentage of passive sentences may serve as a novel target for improving readability.

Cannabinoid ligands regulate bone mass, but skeletal effects of cannabis (marijuana and hashish) have not been reported. Bone fractures are highly prevalent, involving prolonged immobilization and discomfort. Here we report that the major non-psychoactive cannabis constituent, cannabidiol (CBD), enhances the biomechanical properties of healing rat mid-femoral fractures. The maximal load and work-to-failure, but not the stiffness, of femurs from rats given a mixture of CBD and Delta9 -tetrahydrocannabinol (THC) for 8 weeks were markedly increased by CBD. This effect is not shared by THC (the psychoactive component of cannabis), but THC potentiates the CBD stimulated work-to-failure at 6 weeks postfracture followed by attenuation of the CBD effect at 8 weeks. Using micro-computed tomography (muCT), the fracture callus size was transiently reduced by either CBD or THC 4 weeks after fracture but reached control level after 6 and 8 weeks. The callus material density was unaffected by CBD and/or THC. By contrast, CBD stimulated mRNA expression of Plod1 in primary osteoblast cultures, encoding an enzyme that catalyzes lysine hydroxylation, which is in turn involved in collagen crosslinking and stabilization. Using Fourier transform infrared (FTIR) spectroscopy we confirmed the increase in collagen crosslink ratio by CBD, which is likely to contribute to the improved biomechanical properties of the fracture callus. Taken together, these data show that CBD leads to improvement in fracture healing and demonstrate the critical mechanical role of collagen crosslinking enzymes. (c) 2015 American Society for Bone and Mineral Research.

BACKGROUND: Fractures and dislocations of the proximal interphalangeal (PIP) joint of the fingers are among the most common causes of injury in the hand. Objective assessment of the kinematic alterations occurring when the supporting structures are disrupted is critical to obtain a more accurate indication of joint stability. METHODS: An in vitro cadaver model of the hand was used to evaluate the kinematics of the PIP joint in the finger during active unrestrained flexion and extension. The kinematics of the PIP joint following progressive disruption of the main supporting structures was measured using an optical tracking system and compared with those in the intact joint. RESULTS: Flexion of the intact PIP joint was associated with joint compression, volar displacement, and rotational movements. Release of the main soft-tissue stabilizers and 30 % of volar lip disruption resulted in substantial alteration of several kinematic variables. The normalized maximum dorsal/volar translation was 0.1 +/- 1.3 % in the intact group and 14.4 +/- 11.3 % in the injured joint. CONCLUSIONS: In the intact PIP joint, rotations and translation are strongly coupled to the amount of joint flexion. Gross instability of the PIP joint occurs when disruption of the collateral ligaments and volar plate is accompanied by resection of at least 30 % of volar lip of the middle phalanx. Collateral ligament injuries, volar plate injuries alone, and fractures at the volar base of the middle phalanx that involve less than 30 % of the articular surface are unlikely to result in gross instability and may be managed effectively with non-operative treatments.

Zone III midsubstance flexor tendon rupture without underlying pathology is rare. The most common mechanism of injury for a spontaneous rupture is forced extension of an actively flexed distal interphalangeal joint. We describe a patient who experienced closed midsubstance zone III rupture of the flexor digitorum profundus (FDP) tendon of the ring finger at the lumbrical origin in the palm while lifting a heavy object. On exploration, there was no evidence of underlying tendon pathology, and primary end-to-end repair of the FDP was possible. This case highlights the importance of correct preoperative clinical localization of the rupture level, as well as a suggested surgical plan in equivocal cases.

BACKGROUND: To review the results of plating of various fracture patterns of proximal ulna fractures including isolated olecranon fractures, olecranon fractures combined with a coronoid fracture, and olecranon fractures combined with a coronoid and radial head fracture. MATERIALS AND METHODS: The study included 38 patients with either an isolated olecranon fracture or combined injuries, all treated with open reduction and internal fixation of the olecranon. Other procedures were performed as needed, including radial head fixation or arthroplasty, fixation of the coronoid, and repair of the lateral collateral ligament complex. There were 27 men and 11 women with an average age of 49 years. Clinical and radiographic assessment was obtained at an average follow-up time of 15 and 8.4 months, respectively. RESULTS: All fractures healed within 5 months. The average arc of ulnohumeral motion was 91 degrees (range 0 degrees -140 degrees ); average pronation-supination arc was 128 degrees (range 0 degrees -180 degrees ). Subgroup analysis showed a statistically significant lower rotational motion arc in patients with associated radial head (73 degrees ) or coronoid fractures (68 degrees ) compared to isolated olecranon fractures. All other parameters including ulnohumeral motion, complication rate, and revision rate were similar among the groups. CONCLUSIONS: A stable, functional elbow can be restored in most patients with proximal ulna fractures treated with open reduction and internal fixation. Loss of full flexion is likely with high-energy trauma, complex fracture patterns, and concomitant injuries. Fracture patterns involving the coronoid and/or the radial head are associated with restricted forearm rotation. LEVEL OF EVIDENCE: III.

Structural failure of rotator cuff repairs has been attributed to multiple factors, including poor repair tissue quality and poor tendon-bone integration. Chitosan gel has been shown to facilitate scarless healing of soft tissues. In the study reported here, we hypothesized that use of a chitosan gel would improve the morphologic appearance of acute rotator cuff repair in a rat model after 12 weeks. Forty Wistar rats were used. In each case, bilateral tenotomy of the supraspinatus tendon was performed, followed by acute repair with sutures. The left shoulder served as a suture-only control, and the right shoulder was augmented with a chitosan gel applied between the ends of the tendon. Histologic analyses were performed to determine the functional and anatomical characteristics of the repair immediately after the operation and 3 days and 1, 2, 4, 6, 8, and 12 weeks after surgery. In the gel-augmented specimens, number of fibroblasts and amount of repair tissue were increased. Compared with the controls, these specimens showed minimal evidence of monocytic infiltration or inflammatory response around the matrix. Structural properties of the augmented shoulder, including pennation angles and fatty atrophy, were significantly improved. These study results showed that use of a chitosan matrix can enhance biological repair of rotator cuff tendons in a rat model.