The Syringe External Fixator: Short- and Medium-Term Functional Outcomes From This Inexpensive and Customizable Treatment for Comminuted Intra-Articular Fractures of the Hand.

PURPOSE: Comminuted intra-articular fractures and fracture dislocations of the metacarpophalangeal (MCP) and interphalangeal joints are challenging. Dynamic external fixation, permitting early joint motion while still minimizing forces across the healing joint, can result in acceptable postoperative active range of motion (AROM). However, some fractures are not initially stable enough for early dynamic motion; further, many available dynamic external fixation systems are costly and cumbersome. We reviewed our experience using an external fixator made from a 1-mL syringe and K-wires and report outcomes using it as a static fixator, dynamic fixator, or configured as a static fixator and then converted to a dynamic fixator in the clinic. METHODS: Patients with intra-articular fractures and fracture dislocations of the MCP and proximal interphalangeal (PIP) joints treated between 2014 and 2020 using syringe external fixators were retrospectively reviewed. We reviewed demographics, mechanisms, treatment types and durations, and postoperative AROM, as well as complications including infection, pin loosening, nonunion, hardware failure, and need for further surgery. Patients were analyzed by the level of joint injury (MCP versus PIP) and by treatment pattern. RESULTS: After excluding 23 patients with 25 joint injuries who were lost to follow-up or had inadequate outcome data, 27 patients with 29 joint injuries were reviewed. The average follow-up was 171 days after surgery. The postoperative AROM at the MCP level averaged 55° for static fixation and 30° for static-to-dynamic fixation. The postoperative AROM at the PIP level averaged 64° for static fixation, 66° for static-to-dynamic fixation, and 80° for dynamic fixation. Three pin site infections and 2 loose pins were reported. CONCLUSIONS: The syringe external fixator is an inexpensive, effective, and customizable treatment for intra-articular MCP and interphalangeal fractures and fracture dislocations, and results in acceptable postoperative AROM outcomes and complication rates. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

A Simple Phalangeal External Fixator Using Kirschner Wires and Locking Balls: No Need for Cement or Rubber Bands.

The currently available phalangeal external fixators are either commercial and not universally available or made of Kirschner wires and a linkage mechanism such as rubber bands and cement. They are difficult to assemble and difficult to adjust after application. This paper presents an external fixator made of Kirschner wires and locking balls (better known by their commercial name: Jurgan Balls) that is easily assembled on demand in the operating room. The fixator can be applied statically as well as dynamically allowing motion across the interphalangeal joint. I have applied this fixator in a variety of fracture patterns in a total of 14 patients: 11 phalangeal fractures and 3 metacarpal fractures. The fixator was solid and maintained reduction in all phalangeal fractures. Two thumb metacarpal fractures were adequately fixed. One fourth metacarpal fracture failed fixation during surgery and required a different method of fixation. There was no loss or reduction of any of the fractures in the postoperative period. There were no nonunions and no need for second-stage surgeries. All fixators were removed in the clinic without anesthesia. The described external fixator is made of components that are readily available in most operating rooms. It does not require the use of cement or rubber bands. It allows adjustment during surgery and maintains the reduction throughout the postoperative period. It may be a useful tool for open and/or highly comminuted fractures and fracture subluxations of the proximal and middle phalanges as well as the thumb metacarpal.

Course of the radial nerve in relation to the center of rotation of the elbow--the need for a rational safe zone for lateral pin placement.

PURPOSE: To investigate the course and variability of the radial nerve along the lateral humerus in relation to the center of rotation of the elbow joint in the context of lateral pin placement for hinged external fixation. METHODS: A total of 95 formalin-fixed upper extremities were dissected. The course of the radial nerve along the lateral aspect of the humerus was measured at 3 landmarks with respect to the center of rotation of the elbow. We analyzed the data and the landmark positions correlated with the length of the humerus. RESULTS: The measured positions of 3 landmarks of the radial nerve in the lateral aspect of the humerus ranged from 19% to 43% of the length of the humerus and were located, on average, 6.0, 9.7, and 13.5 cm from the lateral center of rotation. CONCLUSIONS: These data help predict the humeral course of the radial nerve and define a safe zone for pin implantation. However, because of variability in the course of the radial nerve, a safe zone cannot fully ensure prevention of iatrogenic injury to the nerve. The safest method of pin application remains mini-open dissection and visual implantation. CLINICAL RELEVANCE: Based on this cadaveric study, it is not possible to define a rational safe zone. The safest method of pin application for dynamic external fixation of the elbow is to perform a mini-open dissection with direct visualization.

The Treatment Method and Results of Percutaneous Pinning and Dynamic External Fixator Application for Unstable Distal Radius Fractures.

OBJECTIVE: The aim of the present study was to present the results of patients with unstable distal radius fracture treated with closed reduction and percutaneous fixation followed by application of the Pennig dynamic wrist fixator to allow early wrist motion. METHODS: Twenty-five patients diagnosed with distal radius fracture and treated with closed reduction and percutaneous fixation followed by application of a dynamic wrist fixator were included in the study. There were 15 (60%) male and 10 (40%) female patients. The mean age of the patients was 47.32 (20-76) years. The mean period between initial trauma and operation was 8.52 (1-23) days. All patients were allowed active shoulder, elbow, and finger exercises immediately after surgery. RESULTS: Radiological evaluation was performed according to the criteria described by Sarmiento and modified by Lidström. Results were excellent in 12 (46.15%), good in 11 (42.30%), and fair in 3 (11.55%) patients. No patient had poor result. Functional scores were assessed according to the Gartland-Werley classification and modified by Sarmiento. Results were excellent in 14 (56%), good in 8 (32%), and moderate in 3 (12%) patients. CONCLUSION: Use of the Pennig dynamic wrist fixator in the treatment of unstable distal radius fractures has advantages, such as ease of use, minimal surgical trauma, allowing early rehabilitation, and early return to daily activities as well as increased anatomical and functional results.

Biomechanical effects of hybrid stabilization on the risk of proximal adjacent-segment degeneration following lumbar spinal fusion using an interspinous device or a pedicle screw-based dynamic fixator.

OBJECTIVE Pedicle screw-rod-based hybrid stabilization (PH) and interspinous device-based hybrid stabilization (IH) have been proposed to prevent adjacent-segment degeneration (ASD) and their effectiveness has been reported. However, a comparative study based on sound biomechanical proof has not yet been reported. The aim of this study was to compare the biomechanical effects of IH and PH on the transition and adjacent segments. METHODS A validated finite element model of the normal lumbosacral spine was used. Based on the normal model, a rigid fusion model was immobilized at the L4-5 level by a rigid fixator. The DIAM or NFlex model was added on the L3-4 segment of the fusion model to construct the IH and PH models, respectively. The developed models simulated 4 different loading directions using the hybrid loading protocol. RESULTS Compared with the intact case, fusion on L4-5 produced 18.8%, 9.3%, 11.7%, and 13.7% increments in motion at L3-4 under flexion, extension, lateral bending, and axial rotation, respectively. Additional instrumentation at L3-4 (transition segment) in hybrid models reduced motion changes at this level. The IH model showed 8.4%, -33.9%, 6.9%, and 2.0% change in motion at the segment, whereas the PH model showed -30.4%, -26.7%, -23.0%, and 12.9%. At L2-3 (adjacent segment), the PH model showed 14.3%, 3.4%, 15.0%, and 0.8% of motion increment compared with the motion in the IH model. Both hybrid models showed decreased intradiscal pressure (IDP) at the transition segment compared with the fusion model, but the pressure at L2-3 (adjacent segment) increased in all loading directions except under extension. CONCLUSIONS Both IH and PH models limited excessive motion and IDP at the transition segment compared with the fusion model. At the segment adjacent to the transition level, PH induced higher stress than IH model. Such differences may eventually influence the likelihood of ASD.

Treatment of intraarticular middle phalanx fractures using the Ligamentotaxor®.

BACKGROUND: We evaluated the outcome of intraarticular middle phalanx fractures after dynamic treatment with the Ligamentotaxor® system. MATERIALS AND METHODS: Ten consecutive patients (seven male, three female; mean age 52 years) with intraarticular middle phalanx fractures were treated with the Ligamentotaxor® between 2009 and 2011. Proximal interphalangeal joint mobility, grip strength and 'Disabilities of the Arm, Shoulder and Hand' (DASH) score were evaluated in a 15-month follow-up. The reconstitution of the intraarticular space was measured immediately after trauma, at 6 weeks and at 15 months by radiograph control. The severity of the trauma was classified according to AO. RESULTS: We found B1 30 %, C1 (Seno I + II) 50 % and C3 (Seno III-V) 20 %. In 60 % of the cases, fractures were localized on the middle base of the fifth digit, in 20 % on the third digit and in 20 % on the index finger. The dynamic treatment lasted 7 weeks; patients were exposed to full workload after 9 weeks. The mean flexion mobility after 15 months reached 73° (range 60-100°), and the extension deficit was 13° (range 0-20°) on average. Grip strength attained 71.3 % (range 60-87 %) of the contralateral side. Initial x-ray after trauma compared to the x-ray after 15 months showed an intraarticular space reconstitution average of 0.5 mm (range 0.1-0.9 mm) anterior-posterior and 0.6 mm (range 0.1-1 mm) lateral. Patients evaluated their outcome with an average of 14.6 points (range 3.3-26.7) using the DASH score. CONCLUSION: Good results can be obtained with the Ligamentotaxor®. We recommend it for the dynamic treatment of intraarticular middle phalanx finger fractures. Larger series and long-term results are needed.