Ericka A. Lawler

Reconstruction for DRUJ Instability

The skeletal architecture of the DRUJ provides minimal inherent stability, as the sigmoid notch is shallow and its radius of curvature is 50% greater than that of the ulnar head [Af Ekenstam F, Hagert CG. Anatomical studies on the geometry and stability of the distal radio ulnar joint. Scand J Plast Reconstr Surg 1985;19(1):17–25]. Due to its incongruent articulation, the DRUJ relies strongly on the surrounding soft tissues for stability. The triangular fibrocartilage complex (TFCC) is generally accepted as the major soft tissue stabilizer of the DRUJ of which the volar and dorsal radioulnar ligaments are the primary components. Restoration of the radioulnar ligaments offers the best possibility to restore the normal DRUJ primary constraints and kinematics. This article presents an update of the procedure developed by the senior author that anatomically reconstructs the palmar and dorsal radioulnar ligaments at their anatomic origins and insertions.

Chronic instability of the distal radioulnar joint.

The ligament reconstruction technique described closely reconstructs the anatomic origin and insertion of the palmar and dorsal radioulnar ligaments. In a series of 14 patients, stability was completely restored in 12. Patients were able to return to their previous work, athletic activities, and avocations without limitations. Recovery of strength and motion was at least 85%. One patient with initial bidirectional instability and good early surgical correction developed recurrent volar instability. Another patient had persistent preoperative ulnocarpal instability and an insufficient volar rim of the sigmoid notch from a previous fracture, but the DRUJ was stabilized. Ligament reconstruction is effective for DRUJ instability but requires a competent sigmoid notch; however, it may not fully correct ulnocarpal instability.

Day-to-Day Variability of Median Nerve Location within the Carpal Tunnel

BACKGROUND Carpal tunnel syndrome is a commonly encountered entrapment disorder resulting from mechanical insult to the median nerve. Magnetic resonance imaging (MRI)-based investigations have documented typical locations of the median nerve within the carpal tunnel; however, it is unclear whether those locations are consistent within an individual on different days. METHODS To determine the day-to-day variability of nerve location, 3.0T MRI scans were acquired from six normal volunteers over multiple sessions on three different days. Half of the scans were acquired with the wrist in neutral flexion and the fingers extended, and the other half were acquired with the wrist in 35 degrees of flexion and the fingers flexed. Prior to half of the scans (in both poses), subjects performed a preconditioning routine consisting of specified hand activities and several repetitions of wrist flexion/extension. The shape, orientation, location, and location radius of variability of the median nerve and three selected flexor tendons were determined for each subject and compared between days. FINDINGS Two of the six subjects had substantial variability in nerve location when the wrist was in neutral, and four of the subjects had high variability in nerve position when the wrist was flexed. Nerve variability was typically larger than tendon variability. The preconditioning routine did not decrease nerve or tendon location variability in either the neutral or the flexed wrist positions. INTERPRETATION The high mobility and potential for large variability in median nerve location within the carpal tunnel needs to be borne in mind when interpreting MR images of nerve location.

Individual flexor tendon identification within the carpal tunnel: A semi-automated analysis method for serial cross-section magnetic resonance images

Carpal tunnel syndrome is commonly viewed as resulting from chronic mechanical insult of the median nerve by adjacent anatomical structures. Both the median nerve and its surrounding soft tissue structures are well visualized on magnetic resonance (MR) images of the wrist and hand. Addressing nerve damage from impingement of flexor digitorum tendons co-occupying the tunnel is attractive, but to date has been restricted by lack of means for making individual identifications of the respective tendons. In this image analysis work, we have developed a region-growing method to positively identify each individual digital flexor tendon within the carpal tunnel by tracking it from a more distal MR section where the respective tendon identities are unambiguous. Illustratively, the new method was applied to MRI scans from four different subjects in a variety of hand poses. Conventional shape measures yielded less discriminatory information than did evaluations of individual tendon location and arrangement. This new method of rapid identification of individual tendons will facilitate analysis of tendon/nerve interactions within the tunnel, thereby providing better information about mechanical insult of the median nerve.

Delivery of Patient-Reported Outcome Instruments by Automated Mobile Phone Text Messaging

Background: Patient-reported outcome (PRO) instruments allow patients to interpret their health and are integral in evaluating orthopedic treatments and outcomes. The purpose of this study was to define: (1) correlation between PROs collected by automated delivery of text messages on mobile phones compared with paper delivery; and (2) patient use characteristics of a technology platform utilizing automated delivery of text messages on mobile phones. Methods: Paper versions of the 12-Item Short Form Health Survey (SF-12) and the short form of the Disabilities of the Arm, Shoulder and Hand (QuickDASH) were completed by patients in orthopedic hand and upper extremity clinics. Over the next 48 hours, the same patients also completed the mobile phone portion of the study outside of the clinic which included text message delivery of the SF-12 and QuickDASH, assigned in a random order. Correlations between paper and text message delivery of the 2 PROs were assessed. Results: Among 72 patients, the intraclass correlation coefficient (ICC) between the written and mobile phone delivery of QuickDASH was 0.91 (95% confidence interval [CI], 0.85-0.95). The ICC between the paper and mobile phone delivery of the SF-12 physical health composite score was 0.88 (95% CI, 0.79-0.93) and 0.86 (95% CI, 0.75-0.92) for the SF-12 mental health composite score. Conclusions: We find that text message delivery using mobile phones permits valid assessment of SF-12 and QuickDASH scores. The findings suggest that software-driven automated delivery of text communication to patients via mobile phones may be a valid method to obtain other PRO scores in orthopedic patients.

Treatment Modalities for Subtrochanteric Fractures in the Elderly

The treatment of subtrochanteric fractures of the femur in the elderly is constantly evolving, yet these fractures remain some of the most challenging that the orthopaedic surgeon faces. The high stresses seen by the subtrochanteric region of the femur make designing the ideal implant difficult. In addition, the muscular forces exerted on the proximal fracture fragment add to the difficulty in reduction and fixation. Currently, there are numerous implants, both intramedullary and extramedullary, designed to treat subtrochanteric fractures. Although there are clear biomechanical advantages to intramedullary devices, these advantages have not translated to improved outcomes compared with extramedullary devices, and good results can be obtained with either intra- or extramedullary implants. Any form of operative management of these fractures is technically demanding and requires a thorough knowledge and understanding of both the anatomy and the chosen implant.

Distal Radius Hemiarthroplasty.

INTRODUCTION Due to a higher risk for implant loosening, particularly of the distal component, patients with physically demanding lifestyles are infrequently considered for total wrist arthroplasty (TWA). A distal radius hemiarthroplasty may obviate the need for the strict restrictions recommended for patients treated by TWA, thus providing another surgical option for active patients with severe wrist arthritis, especially those with articular degeneration of the lunate facet of the radius, capitate head, or combination of both, who are not typically candidates for traditional motion-preserving procedures. MATERIALS AND METHODS Eight fresh-frozen cadaver limbs (age range, 43-82 years) with no history of rheumatoid arthritis or upper extremity trauma were used. Radiodense markers were inserted in the radius and hand. Posteroanterior (PA) fluoroscopic images with the wrist in neutral, radial deviation, and ulnar deviation, and lateral images with the wrist in neutral, flexion, and extension were obtained for each specimen before implantation, after distal radius hemiarthroplasty, and after combined hemiarthroplasty and PRC. RESULTS On the PA images, the capitate remained within 1.42 and 2.21 mm of its native radial-ulnar position following hemiarthroplasty and hemiarthroplasty with PRC, respectively. Lateral images showed the capitate remained within 1.06 mm of its native dorsal-volar position following hemiarthroplasty and within 4.69 mm following hemiarthroplasty with PRC. Following hemiarthroplasty, capitate alignment changed 2.33 and 2.59 mm compared with its native longitudinal alignment on PA and lateral films, respectively. These changes did not reach statistical significance. As expected, significant shortening in longitudinal alignment was seen on both PA and lateral films for hemiarthroplasty with PRC. CONCLUSION A distal radius implant hemiarthroplasty with or without a PRC provides good static alignment of the wrist in a cadaver model and thus supports the concept as potential treatment alternatives for advanced wrist arthritis; however, combined hemiarthroplasty with a PRC has more clinical relevance because it avoids the risk of proximal carpal row instability and eliminates the commonly arthritic radioscaphoid joint.

Nonunion Rates Among Ulnar-Shortening Osteotomy for Ulnar Impaction Syndrome: A Systematic Review

PURPOSE The purpose of this study was to systematically review all available literature reporting nonunion rates of ulnar-shortening osteotomies (USO) used for the treatment of ulnar impaction syndrome (UIS) and to compare those rates among transverse versus oblique cuts for the osteotomy. METHODS Electronic databases including PubMed, EMBASE, and Cochrane Central Register of Controlled Trials were searched for studies that evaluated outcomes of both transverse and oblique USO for UIS. Level of evidence was determined by 2 independent reviewers. Studies were screened based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and inclusion and exclusion criteria were applied. A total of 37 studies (1,423 patients) were included in final analysis. The average rate of nonunion and delayed union for each group (transverse and oblique osteotomy) was calculated. RESULTS The average rate of nonunion among all osteotomies was 4.0%. The average rate of nonunion was 4.16% and 3.86% in transverse osteotomies and oblique osteotomies, respectively. This difference was not statistically significant. The average rate of delayed union, in those studies that reported delayed union, was 5.7%. The average rate of delayed union was 7.41% and 4.1% in transverse osteotomies and oblique osteotomies, respectively. CONCLUSIONS Based on our review of the literature, there is no difference in the rate of nonunion between transverse and oblique osteotomies. Therefore, the decision of which of the 2 surgical techniques should not be based on rate of nonunion. TYPE OF STUDY/LEVEL OF EVIDENCE Therapeutic IV.

Endoscopic Versus Open Carpal Tunnel Release: A Detailed Analysis Using Time-Driven Activity-Based Costing at an Academic Medical Center

PURPOSE In order to effectively improve value in health care delivery, providers must thoroughly understand cost drivers. Time-driven activity-based costing (TDABC) is a novel accounting technique that may allow for precise characterization of procedural costs. The purpose of the present study was to use TDABC to characterize costs in a high-volume, low-complexity ambulatory procedure (endoscopic vs open carpal tunnel release [CTR]), identify cost drivers, and inform opportunities for clinical improvement. METHODS The costs of endoscopic and open CTR were calculated in a matched cohort investigation using TDABC. Detailed process maps including time stamps were created accounting for all clinical and administrative activities for both the endoscopic and the open treatment pathways on the day of ambulatory surgery. Personnel cost rates were calculated accounting for capacity, salary, and fringe benefits. Costs for direct consumable supplies were based on purchase price. Total costs were calculated by aggregating individual resource utilization and time data and were compared between the 2 surgical techniques. RESULTS Total procedural cost for the endoscopic CTR was 43.9% greater than the open technique (

Thumb Metacarpophalangeal Ulnar Collateral Ligament Injuries: A Biomechanical Simulation Study of Four Static Reconstructions

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