Comparison of Lag Versus Nonlag Screw Fixation for Long Oblique Proximal Phalanx Fractures: A Biomechanical Study.

PURPOSE: To compare lag versus nonlag screw fixation for long oblique proximal phalanx (P1) fractures in a cadaveric model of finger motion via the flexor and extensor tendons. METHODS: We simulated long oblique P1 fractures with a 45° oblique cut in the index, middle, and ring fingers of 4 matched pairs of cadaveric hands for a total of 24 simulated fractures. Fractures were stabilized using 1 of 3 techniques: two 1.5-mm fully threaded bicortical screws using a lag technique, two 1.5-mm fully threaded bicortical nonlag screws, or 2 crossed 1.14-mm K-wires as a separate control. The fixation method was randomized for each of the 3 fractures per matched-pair hand, with each fixation being used in each hand and 8 total P1 fractures per fixation group. Hands were mounted to a custom frame where a computer-controlled, motor-driven, linear actuator powered movement of the flexor and extensor tendons. All fingers underwent 2,000 full flexion and extension cycles. Maximum interfragmentary displacement was continuously measured using a differential variable reluctance transducer. Our primary outcome was the difference in the mean P1 fragment displacement between lag and nonlag screw fixation at 2,000 cycles. RESULTS: The observed differences in mean displacement between lag and nonlag screw fixation were not statistically significant throughout all time points. A two one-sided test procedure for paired samples confirmed statistical equivalence in the fragment displacement between these fixation methods at all time points, including the primary end point of 2,000 cycles. CONCLUSIONS: Nonlag screws provided equivalent biomechanical stability to lag screws for simulated long oblique P1 fractures during cyclic testing in this cadaveric model. CLINICAL RELEVANCE: Fixation of long oblique P1 fractures with nonlag screws has the potential to simplify treatment without sacrificing fracture stability during immediate postoperative range of motion.

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.

Minimally Invasive Intramedullary Screw Versus Plate Fixation for Proximal Phalanx Fractures: A Biomechanical Study.

PURPOSE: To compare the maximum interfragmentary displacement of short oblique proximal phalanx (P1) fractures fixed with an intramedullary headless compression screw (IMHCS) versus a plate-and-screws construct in a cadaveric model that generates finger motion via the flexor and extensor tendons of the fingers. METHODS: We created a 30° oblique cut in 24 P1s of the index, middle, ring, and little fingers for 3 matched pairs of cadaveric hands. Twelve fractures were stabilized with an IMHCS using an antegrade, dorsal articular margin technique at the P1 base. The 12 matched-pair P1 fractures were stabilized with a radially placed 2.0-mm plate with 2 bicortical nonlocking screws on each side of the fracture. Hands were mounted to a frame allowing a computer-controlled, motor-driven, linear actuator powered movement of fingers via the flexor and extensor tendons. All fingers underwent 2,000 full-flexion and extension cycles. Maximum interfragmentary displacement was continuously measured using a differential variable reluctance transducer. RESULTS: The observed mean displacement differences between IMHCS and plate-and-screws fixation was not statistically significant throughout all time points during the 2,000 cycles. A 2 one-sided test procedure for paired samples confirmed statistical equivalence in fracture displacement between fixation methods at the final 2,000-cycle time point. CONCLUSIONS: The IMHCS provided biomechanical stability equivalent to plate-and-screws for short oblique P1 fractures at the 2,000-cycle mark in this cadaveric model. CLINICAL RELEVANCE: Short oblique P1 fracture fixation with an IMHCS may provide adequate stability to withstand immediate postoperative active range of motion therapy.

Early Outcomes of Endoscopic Versus Open Carpal Tunnel Release.

PURPOSE: To compare the short-term outcomes of endoscopic carpal tunnel release (ECTR) and open carpal tunnel release (OCTR), including patient-reported outcomes, pain and satisfaction scores, return to work, and postoperative prescription pain medication use. METHODS: We included all patients over 18 years of age undergoing carpal tunnel release at a single hand center between January 2018 and December 2019. The carpal tunnel release method was driven by variations in surgeon practice. Data from patient-reported outcomes measurement information system (PROMIS) questionnaires and brief Michigan hand outcomes questionnaires and data on patient-reported pain levels, satisfaction with care, return to work, and postoperative prescription pain medication use were collected at preoperative visits and the first follow-up visit between postoperative days 7 and 14. RESULTS: We included 678 (586 ECTR and 92 OCTR) patients. The median age was 58 years, and 75% of the patients were women. At early follow up, patients who underwent OCTR reported significantly lower postoperative PROMIS upper-extremity scores than those who underwent ECTR (median, 32 vs 36 points, respectively) but similar postoperative PROMIS pain interference, global physical health, global mental health, and brief Michigan hand outcomes questionnaire scores. The postoperative pain and satisfaction scores were similar between the 2 groups. In multivariable models, patients who underwent OCTR had 62% lower odds of returning to work and 30% greater odds of remaining on a postoperative pain prescription at the first follow-up visit. CONCLUSIONS: This study found no evidence suggesting the definitive superiority of 1 surgical technique with regard to clinical outcomes in the early postoperative period. However, OCTR was associated with lower postoperative PROMIS upper-extremity scores of unclear clinical significance, higher odds of remaining on pain medication, and lower odds of returning to work by the first postoperative visit. Endoscopic carpal tunnel release may be preferred in patients who need to return to work within the first 2 weeks after the procedure. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

High multi-cytokine levels are not a predictive marker of alloimmunization in transfused sickle cell disease patients.

Patients with sickle cell disease (SCD) receive multiple red blood cell (RBC) transfusions for both prevention of and therapy for disease-related complications. In some patients, transfusion results in development of both allo- and auto-antibodies to RBC antigens. What precipitates the antibody formation is currently unclear. It has been hypothesized that a pro-inflammatory state preceding the therapeutic transfusion may be a predisposing factor. Plasma levels of ten cytokines were evaluated upon recruitment to the study of 83 children with SCD undergoing therapeutic RBC transfusions. The levels of cytokines were correlated with development of anti-RBC antibodies prior, or during seven years post recruitment. Twelve subjects displayed significantly higher levels of all cytokines examined, with pro-, as well as anti-inflammatory properties. Surprisingly, the elevated levels of cytokines were preferentially found in patients without anti-RBC allo- and/or auto-antibodies. Further, presence of high cytokine levels was not predictive of anti-RBC antibody development during the subsequent seven year follow up. These data suggest that the increased concentration of multiple cytokines is not a biomarker of either the presence of or susceptibility to the development of RBC alloimmunization.

Patient-Reported Lower Extremity Outcomes Following Fibula or Medial Femoral Condyle Free Flaps for Upper Extremity Defects.

BACKGROUND: Free fibula flap (FFF) and medial femoral condyle (MFC) flap are commonly used for upper extremity osseous reconstruction, yet donor-site morbidity has never been systematically compared. METHODS: Patients who underwent an FFF or MFC for upper extremity extra-carpal osseous reconstruction at 3 academic hand centers were retrospectively identified. Only patients who underwent reconstruction for a defect in which either flap type is routinely used or has been described in the literature were deemed eligible. Patients who agreed to participate were asked to complete the Lower Extremity Functional Scale (LEFS) and Lower Limb Core Scale (LLCS). The reported population norm median score of LEFS is 77 points. The LLCS population norm mean score is 90.52 points. RESULTS: Twenty-one patients (10 MFC, 11 FFF) were enrolled. The median LEFS score for patients after MFC was 76 (interquartile range [IQR], 49-80) points and 75 (IQR, 56-79) points after FFF. The median LLCS score for patients after MFC was 96.4 (IQR, 87.9-100) points and 100 (IQR, 91-100) points after FFF. Median LEFS scores were slightly below the population norm, whereas median LLCS scores were above the norm for both FFF and MFC. All patients stated they would have the surgery again and that any dysfunction or pain in the leg was justified by the benefit in the arm. CONCLUSIONS: When considering whether to use an MFC or FFF for upper extremity reconstruction, both flap types appear to result in modest and comparable donor-site morbidity.

A Meta-Analysis of Biomechanical Studies for Suture Button Pullout Versus Suture Anchor Repair of Flexor Digitorum Profundus Avulsions.

BACKGROUND: There is no current consensus on which of the two most common flexor digitorum profundus (FDP) avulsion repair constructs, via suture button pullout (SBP) or suture anchor (SA), is biomechanically superior. Our purpose was to compare these repair methods via systematic review and meta-analysis of available literature. METHODS: We performed a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-guided systematic review of PubMed, the Cochrane library, and Embase. We only included studies with direct comparison data for both techniques. We performed a meta-analysis comparing the reported biomechanical results using pooled data for initial repair stiffness (N/mm), gap formation (mm), and ultimate load to failure (N). RESULTS: Seven studies met inclusion criteria, including a total of 201 cadaveric specimens. Four studies reported initial construct stiffness, with pooled analysis showing superiority for SA repairs (P < .05). Four studies evaluated gap formation, with pooled analysis demonstrating less gapping with SA repair (P < .05). Mean gap formation was 2.4 (±1.4) mm and 3.9 (±2.0) mm for the SA and SBP groups, respectively. All 7 studies assessed load to failure, with pooled analysis revealing no significant difference between groups (P > .05). We lacked statistical power to determine equivalence between techniques for load to failure. Both groups had failure values significantly lower than the native FDP. CONCLUSIONS: Via meta-analysis, there was increased initial construct stiffness and less gap formation for SA compared to SBP for FDP reinsertion, with no significant differences for ultimate failure load.

Long-Term Patency and Fluid Dynamics of Recipient Artery after End-to-Side Anastomosis for Free Tissue Transfer.

BACKGROUND: End-to-end microvascular anastomoses sacrifice downstream inline perfusion of the recipient vessels. End-to-side anastomoses, in theory, maintain distal inline flow of the recipient vessel. The proposed benefit of the end-to-side technique depends on patency of the distal vessels and subsequent flow parameters, but maintenance of distal perfusion has not been conclusively demonstrated. METHODS: Fifteen patients who underwent a successful extremity free flap procedure via end-to-side anastomoses to a noncritical vessel between 2003 and 2017 were enrolled. Recipient artery patency distal to the anastomosis was assessed using pulse volume recordings and duplex ultrasound imaging. Resistance indices, flow velocities, vessel diameters, volumetric flow, and turbulent flow dimensionless number (Reynolds number) were measured. Comparisons were made to the ipsilateral collateral vessel as well as to the vessels on the nonoperative contralateral limb using paired t tests. RESULTS: Downstream flow was identified in 14 of 15 patients (93 percent patency). There was no statistical difference in resistive indices comparing the anastomotic vessel (0.859 ± 0.300) and the collateral vessel (0.853 ± 0.179) of the ipsilateral extremity. Ultrasound flows were similar; the anastomotic vessel demonstrated downstream volumetric flows of 139 ± 92.0 cm3/min versus 137 ± 41.6 cm3/min within the same vessel of the nonoperative contralateral limb. The anastomotic vessel had Reynolds numbers well below the turbulent threshold (448 ± 202 and 493 ± 127 for the anastomotic and nonoperative contralateral limb, respectively). CONCLUSION: End-to-side anastomosis to noncritical vessels resulted in a 93 percent long-term recipient vessel patency rate, with no statistically significant changes in volumetric flows, resistive indices, or fluid dynamics in the vessels that remained patent.

High-Fidelity Wrist Fracture Phantom as a Training Tool to Develop Competency in Orthopaedic Surgical Trainees.

BACKGROUND: This article will describe the development of a low-cost 3D-printed medical phantom of the arm with a distal radius fracture (DRF) to facilitate training of reduction and splinting techniques. The phantom incorporates tactile responses and visual stimuli from fluoroscopy to assist skill acquisition in a clinical setting. This provides feedback to trainees to help them develop competency and knowledge before providing care to patients. METHODS: Phantoms were developed through advice and feedback from fellowship-trained hand surgeons and orthopaedic senior and junior residents. Phantoms were then pilot tested during a surgical skills examination, with residents having minimal previous exposure to distal radial reduction techniques. Residents were evaluated on procedure speed and accuracy by attending surgeons using the objective structured assessment of technical skills. Residents then completed a written knowledge examination about relevant requirements of DRF management and feedback on their opinion of the exercise using the Likert scale. RESULTS: Residents who passed the hands-on examination also scored higher on the written examination. All residents reported that the phantom was beneficial and motivating as part of their overall training. DISCUSSION: Real-time feedback using a phantom limb and fluoroscopic imaging, in conjunction with guidance from surgeons, allows residents to learn and practice DRF reduction and splinting techniques. These educational exercises are relatively low-cost and remove the risk of potential harm to patients during early skill acquisition. This training method may be a predictor of surgical performance in addition to providing assessment of background knowledge. Additional training sessions will be required to determine the effect of repeat exposure to residents' proficiency and comprehension.