"Cat and dog bite injuries of the hand: early versus late treatment".

INTRODUCTION: Animal bites of the hand are common injuries in the emergency department. Serious complications may occur if those injuries are not treated adequately. The purpose of the study was to examine if there is a difference between the treatment of animal bite injuries at an early stage (first treatment within the first 24 h after injury, group I) versus a later stage (first treatment more than 24 h after injury, group II) retrospectively. MATERIALS AND METHODS: Between January 2010 and March 2016, a total of 69 patients with cat and dog bite injuries were treated in our hospital emergency room (ER). 45 patients arrived at the ER within 24 h after the injury (group I). 24 patients were treated more than 24 h after injury for the first time (group II). A retrospective study with evaluation of the clinical data including wound aspect, tissue damage, treatment, and antibiotics was performed. RESULTS: In group I, 27 were outpatients and 18 were in-house patients with an average hospitalization period of 3.3 days ± 1.12 days. 16 patients were treated conservatively. An operation was performed in 29 patients and in 3 patients a second look surgery was necessary. In group II, 5 patients were outpatients and 19 were inpatients with an average hospitalization period of 5.8 days ± 1.9 days. An operation was performed in 22 patients, and 2 were treated conservatively. In five patients, a second look surgery was necessary in group II. CONCLUSION: The study demonstrates that an early treatment of cat and dog bite injuries leads to less second-look operations and a shorter hospitalization. Hence, animal bite injuries of the hands should be treated immediately to avoid further complications. LEVEL OF EVIDENCE: Level 3, therapeutic.

Long-term outcome of fingertip reconstruction with the homodigital neurovascular island flap.

INTRODUCTION: Fingertip injuries are frequent and several surgical strategies exist to reconstruct the amputated part and restore function and appearance. Yet, long-term results are rarely published. The purpose of this study was to examine the long-term clinical outcome of neurovascular island flaps for traumatic fingertip amputation of Allen type III/IV injuries. MATERIALS AND METHODS: We retrospectively analysed a cohort of patients with traumatic fingertip amputation that underwent reconstruction with a neurovascular island flap from January 2003 to December 2014. No mandatory splinting was applied after surgery. 28 participants (29 fingers) were available for follow-up at mean 8 years after reconstruction. Activities of daily living were measured with the disabilities of the arm, shoulder and hand questionnaire. Grip strength and finger motion were assessed using a Jamar dynamometer and a goniometer. Two-point discrimination and Semmes-Weinstein monofilaments were used to evaluate sensory recovery. RESULTS: No intraoperative complications occurred and all flaps survived. Mean flap size was 4.7 ± 0.6 cm2. Active motion of the fingers was over 95% of the contralateral side at follow-up. Three patients showed mild extension lag of the proximal interphalangeal joint. The grip strength of the affected hand and of each of the affected fingers was over 70% of the contralateral side. In comparison to the contralateral side we did not detect any significant difference for the Semmes-Weinstein monofilament test, but two-point discrimination (5.1 ± 1.7 mm) was significantly impaired. According to the Lim classification 1 of 14 nails with hook nail deformity showed grade 3 breaking of the nail. The DASH score was 16.0. All patients returned to their original occupation and patient satisfaction with the procedure was high. CONCLUSIONS: The risk for disabling flexion contracture seems to be small even without mandatory splinting. Neurovascular island flaps for fingertip amputation of Allen type III/IV injuries are a reliable tool in fingertip reconstruction in the long term.

Practicability of a locking plate for difficult pathologies of the scaphoid.

INTRODUCTION: Headless compressions screws are the most implanted devices for scaphoid fractures and nonunions. For cases when screw osteosynthesis is not possible, a special locking plate for scaphoid reconstruction has been developed. The purpose of this study was to evaluate the safety and practicability of this device for difficult scaphoid pathologies. MATERIALS AND METHODS: Between March 2010 and December 2014, 20 patients (age range 16-59 years) were treated with scaphoid locking plate osteosynthesis. In 17 cases it was due to scaphoid nonunion or delayed union and in three cases to treat a complex multi-fragmentary fracture of the scaphoid. Most of the initial fractures were located either in the proximal third (n = 9) or the middle third (n = 8) of the scaphoid. RESULTS: Mean follow-up was 14.6 ± 8.9 months (range 2-30 months). All three scaphoid fractures (100%) showed bony healing in the CT scan after 2.7 ± 0.6 months. 15 of 17 (88.2%) patients with scaphoid nonunion demonstrated bony healing in the latest CT scan at an average of 6.2 ± 8.1 months (range 2-11 months) after scaphoid reconstruction. Range of motion (extension/flexion) was 104° ± 18.4° (range 80°-150°) and about one third less than the unaffected side. The average grip strength averaged 38.2 kg on the operated side and 44.1 kg on the unaffected side after surgery. 13 plates (65%) had to be removed due to impaction of the plate or protrusion of the screws. CONCLUSIONS: This new locking device for scaphoid reconstruction seems to be a safe, useful and reliable tool in the treatment of difficult nonunions or multi-fragmentary scaphoid fractures. The practicability is convincing and satisfying fusion rates can be accomplished. However, most patients require hardware removal. We recommend using this plate as a rescue option when a stable osteosynthesis is necessary for the healing process and screw fixation has already failed or is not possible.

[Anatomical aspects regarding the endoscopic release of the nervus interosseus anterior]. / Anatomische Aspekte zur endoskopischen Dekompression beim Interosseus-anterior-Syndrom.

BACKGROUND: Decompression of the anterior interosseous nerve can be performed in an open operative exploration or endoscopically. Using an endoscopic decompression superficial anatomical landmarks serve as reference point. The aim of the study was to determine the location of the distribution of the median nerve in relation to the elbow joint in order to facilitate preparation during endoscopic decompression. MATERIALS AND METHODS: The median nerve and the anterior interosseous nerve were dissected in 31 human specimens with regard to the elbow joint. The superficial anatomical landmark was the intercondyle line between the medial and lateral epicondyles. The distance between the origination of the anterior interosseous nerve of the median nerve was measured in relation to the intercondyle line. RESULTS: The anatomical preparation was done using 62 adult cadaveric upper extremities. 11 specimens were formalin fixed and 20 specimens were fresh frozen cadaveric upper extremities. The average of the intercondyle distance was 7.2 cm ± 0.5 (min. 5.8; max. 7.8). The anterior interosseous nerve originated from the median nerve in average 39 mm ± 18 (min. 8; max. 80) distal to the intercondyle line. In 12 cases the distance was within the first 2 cm. There was only a correlation between the length of the upper arm and the nerve junction. CONCLUSION: The anterior interosseous nerve originated from the median nerve in average 4 cm distal to the intercondyle line. Although there was a distribution under 2 cm in around 20 % of the cases. This is very important with regard to the endoscopically technique and should be considered.

Trans-sacral bar osteosynthesis provides low mortality and high mobility in patients with fragility fractures of the pelvis.

Operative treatment of osteoporosis-associated fragility fractures of the pelvis (FFP) and the sacrum is advocated with immobilizing or longstanding pain, fracture progression and displacement. We analyzed clinical outcomes regarding mobility, quality of life, and mortality of patients with FFP treated with trans-sacral bar (TB) osteosynthesis through S1. Demographics, clinical data, and operation-related data of patients with an FFP treated with TB were acquired from chart review. We assessed mortality, quality of life (EQ-5D), mobility, and residential status at follow-up. Seventy-nine females and six males with a median age of 78.0 years (IQR 73-84) were included, median follow-up was 3.2 years. Medical complications during hospitalization occurred in 28%. Operative revision was carried out in 15% of patients. One-year survival was 90.4%, this was associated with shorter preoperative and total length of stay in hospital (p 0.006 and 0.025, respectively). At follow-up, 85% lived at home and 82% walked with or without walking aid. Higher EQ-5D was reached with higher mobility status and living at home (p < 0.001 and < 0.001, respectively). TB osteosynthesis is an adequate and reliable method for fixation of FFP in the posterior pelvic ring to ensure timely mobilization. Shorter preoperative and total length of stay had lower mortality rates, advocating a standardized management protocol to limit time delay to operative therapy. Patients treated with TB osteosynthesis had low 1-year mortality of less than 10%.

Biomechanical comparison of dorsal nail plate versus screw and K-wire construct for extra-articular distal radius fractures in a cadaver bone model.

PURPOSE: The purpose of the study was to compare the biomechanical stability of distal radius fracture fixation with 2 new implants, the DNP (Hand Innovations LLC, Miami, FL), a dorsal locked hybrid of nail and plate, and the XSCREW (Zimmer, Freiburg, Germany), an implant combining a cannulated screw and K-wires, in a cadaver bone distal radius fracture model. METHODS: Eight pairs of fresh-frozen cadaver radii were used. To simulate an extra-articular distal radius fracture, a 5-mm volar open wedge osteotomy was made. Axial loads of 10 to 100 N and torque loads of -1.5 to 1.5 Nm were applied by a testing machine to the intact radii and to the radii after each device was fixed as recommended by the manufacturer. One thousand cycles in torque and failure tests were performed. RESULTS: With a median of 136.0 N/mm, the axial stiffness of XSCREW-fixed specimens was higher than that of DNP-fixed specimens, with a median of 69.5 N/mm, but differences were not statistically significant. With a median of 0.163 Nm/ degrees , the torque stiffness of XSCREW-fixed specimens was significantly higher than that of DNP-fixed specimens, with a median of 0.068 Nm/ degrees . The XSCREW-group reached 33% of the axial stiffness and 49% of the torque stiffness of the intact radii, and the DNP-group reached 14% of the axial stiffness and 20% of the torque stiffness of the intact radii. CONCLUSIONS: In this human cadaver bone biomechanical study, the XSCREW provided more stability than the DNP in torque stiffness but not in axial stiffness.

Number and locations of screw fixation for volar fixed-angle plating of distal radius fractures: biomechanical study.

PURPOSE: To compare the biomechanical properties of different numbers and locations of screws in a multidirectional volar fixed-angle plate in a distal radius osteotomy cadaver model. METHODS: We created an extra-articular fracture in 16 pairs of fresh-frozen human cadaver radiuses. The 32 specimens were randomized into 4 groups. All fractures were fixated with a multidirectional volar fixed-angle plate. We tested 4 different screw-placement options in the distal fragment. The distal fragment was fixed with 4 locking screws in the distal row of the plate in group a, and with 4 locking screws alternately in the distal and proximal rows in group b. In group c, 3 locking screws were used in the proximal row; in group d, 7 locking screws were used, filling all screw holes in the distal and proximal rows of the plate. The proximal fragment was fixed with 3 screws. The specimens were loaded with 80 N under dorsal and volar bending and with 250 N axial loading. Finally, load to failure tests were performed. RESULTS: Group d had the highest mean stiffness, 429 N/mm under axial compression, and was statistically significantly stiffer than the other groups. Group b had a mean stiffness of 208 N/mm, followed by group a, with 177 N/mm. Group c showed only a mean stiffness of 83 N/mm under axial compression. There were no statistically significant differences under dorsal and volar bending. CONCLUSIONS: In this model of distal radial fractures, there was a difference regarding the stiffness and the placement of screws in the distal rows of a volar fixed-angle plate. Inserting screws in all available holes in the distal fragment offered the highest stability. Using only the proximal row with 3 screws created an unstable situation. Based on these findings, we recommend placing at least 4 screws in the distal fragment and assigning at least 2 screws to the distal row of the multidirectional screw-holes.

Minimal-invasive stabilization of anterior pelvic ring fractures with retrograde transpubic screws.

BACKGROUND: In the vast majority of patients with pelvic ring lesions, there is a combination of fractures of the posterior and anterior pelvic ring. Anterior fractures are painful and contribute to loss of stability of the pelvic ring. For these reasons, stabilization of pubic rami fractures is recommended together with posterior pelvic ring fixation. Retrograde transpubic screw osteosynthesis enjoys increasing acceptance due to its minimal invasive technique and adequate stability. PATIENTS AND METHODS: We retrospectively reviewed the results of 158 retrograde transpubic screw osteosyntheses in 128 patients with pelvic ring lesions including a pubic ramus fracture. Sixty-three patients suffered a high-energy injury, 65 a fragility fracture of the pelvis. RESULTS: One hundred and forty-six screws (92.4%) were inserted through a percutaneous procedure. There were no vascular, neurological or urological complications. Fifty-nine screws (39%) yielded an excellent reduction with less than one cortical width of displacement. Slight secondary displacement was seen in 33 of these fractures (55.9%). Early surgical complications were seen in 16 screws (10.1%): suboptimal pathway in 10, local hematoma in 4 and local infection in 3. Early revision surgery was done in 7 screws (4.4%). Median follow-up was 27.6 weeks, 83 screws (52.5%) had a follow-up of more than 6 months. During follow-up, 7.6% of screws loosened. Operative revision was performed in 13%. 75 fractures (90.3%) with a follow-up of ≥ 6 months showed radiographic evidence of healing. There was no difference in the healing rate of high-energy and fragility fractures. Nonunion rate was not dependent on the quality of primary reduction, secondary displacement, or screw loosening. Infection (p 0.001) and surgery ≥ 6 months after trauma (p 0.02) more often led to nonunion. CONCLUSION: Retrograde transpubic screw osteosynthesis is a reliable method for splinting pubic rami fractures in high and low energy pelvic trauma. Although a slight secondary fracture displacement is seen in most cases, it does not affect fracture healing. Retrograde transpubic screw is a adequate minimal-invasive osteosynthesis to stabilize the anterior pelvic ring, especially in fragility fracture of the pelvis. Delayed operation (> 6 months) and infection show higher rate of nonunion.

[Biomechanical study of four palmar locking plates and one non-locking palmar plate for distal radius fractures: stiffness and load to failure tests in a cadaver model]. / Biomechanische Studie zu vier winkelstabilen distalen palmaren Radiusplatten und einer nichtwinkelstabilen Radiusplatte: Steifigkeit und Versagenstests am Kadavermodell.

Five different palmar fixation plate designs were compared in a distal radial osteotomy cadaver model with regard to their biomechanical properties. A metaphyseal osteotomy gap of 1 cm was performed and the osteosynthesis was plated according to the manufacturer's instructions. Axial load was applied to the construct by a pneumatic material testing machine. Five implant groups with eight cadavers each were tested concerning stiffness. None of the constructs developed deformity and movement of the fracture gap larger than 2 mm with a load of 100 N. Increasing the load to 250 N revealed significant differences in stiffness and failure load between the different plates. The mean stiffness under axial load (mean+/-standard deviation) was 356.4+/- 138.6 N/mm for the radius correction plate without lateral tongue, 299.7+/-86.3 N/mm for the radius correction plate with lateral tongue, 132.8+/-41.5 N/mm for the distal volar radius plate, 112.5+/-40.2 N/mm for the 3.5 mm titanium locking compression plate and 91.9+/-29.2 N/mm for the standard stainless steel 3.5 mm T-Plate. The non-angular stable implant (STP plate) had the lowest stiffness. Unexpectedly, there were differences over 100% concerning the stiffness between the at first glance nearly similar angular stable implants. Additionally, a review of the literature concerning biomechanical investigations of the distal radial fracture was performed.

[V-y flap for restoration of the fingertip]. / Der V-Y-Lappen zur Versorgung von Fingerkuppendefekten.

OBJECTIVE: Restoration of the fingertip with a neurovascular V-Y flap. INDICATIONS: Transverse or oblique defects of the fingertip, also with exposed bone of the distal phalanx. CONTRAINDICATIONS: Larger defects of the phalanx over the proximal interphalangeal joint. Crush injury of the finger. Preexisting lesions of the fingertip. Circulatory disorder. Contamination. Infection of the finger. SURGICAL TECHNIQUE: A single volar (Tranquilli-Leali, Atasoy) or a bilateral V-Y flap (Geissendörfer, Kutler) is used for restoration of the fingertip. The incision is V-shaped and will be converted to a Y, as the flap is advanced. The subcutaneous tissue of the flap contains neurovascular structures, and provides sensibility and padding of the fingertip. A distal advancement of the flap up to 10 mm is possible with this technique. POSTOPERATIVE MANAGEMENT: Immobilization in a two-finger splint for 1 week. RESULTS: Good functional results.

Evidence-based flexor tendon repair.

The goal of flexor tendon repair is to achieve normal range of motion of the finger or thumb. The surgical approach depends on the level of injury. Multistrand core suture repairs are recommended for primary flexor tendon repair. It is evident that at least 4 strands are required to an initiate and active range of motion protocol. The epitendinous suture can also increase the strength of the repair. Careful attention to the post-operative therapy regiment is critical to a successful repair.

Mobilization of CD34+-progenitor cells in patients with severe trauma.

Circulating CD34+ progenitor cells () gained importance in the field of regenerative medicine due to their potential to home in on injury sites and differentiate into cells of both endothelial and osteogenic lineages. In this study, we analyzed the mobilization kinetics and the numbers of CD34+, CD31+, CD45+, and CD133+ cells in twenty polytrauma patients (n = 13 male, n = 7 female, mean age 46.5±17.2 years, mean injury severity score (ISS) 35.8±12.5 points). In addition, the endothelial differentiation capacity of enriched CD34+cells was assessed by analyzing DiI-ac-LDL/lectin uptake, the expression of endothelial markers, and the morphological characteristics of these cells in Matrigel and spheroid cultures. We found that on days 1, 3, and 7 after a major trauma, the number of CD34+cells increased from 6- up to 12-fold (p<0.0001) over the number of CD34+cells from a control population of healthy, age-matched volunteers. The numbers of CD31+ cells were consistently higher on days 1 (1.4-fold, p<0.01) and 7 (1.3-fold, p<0.01), whereas the numbers of CD133+ cell did not change during the time course of investigation. Expression of endothelial marker molecules in CD34+cells was significantly induced in the polytrauma patients. In addition, we show that the CD34+ cell levels in severely injured patients were not correlated with clinical parameters, such as the ISS score, the acute physiology and chronic health evaluation II score (APACHE II), as well as the sequential organ failure assessment score (SOFA-2). Our results clearly indicate that pro-angiogenic cells are systemically mobilized after polytrauma and that their numbers are sufficient for the development of novel therapeutic models in regenerative medicine.

Are there any differences in various polyaxial locking systems? A mechanical study of different locking screws in multidirectional angular stable distal radius plates.

Numerous angular stable plates for the distal radius exist, and technically based comparisons of the polyaxial locking interfaces are lacking. The aim of this mechanical study was to investigate three different locking interfaces of angular stable volar plates by cantilever bending: VA-LCP Two-Column Distal Radius Plates 2.4 mm (Synthes® GmbH, Oberdorf, Switzerland), IXOS® P4 (Martin, Tuttlingen, Germany) and VariAX™ (Stryker®, Duisburg, Germany). We assessed the strength of 0°, 5°, 10° and 15° screw locking angles and tested the bending strength from 10° to 5° angles by cyclic loading until breakage. The final setup repeated the above assessments by inclusion of four locking screws. The single screw-plate interfaces of the VA-LCP showed the highest bending moment at an angle of 0° and 5°, the IXOS® P4 at an angle of 10° and 15° and the VariAX™ when changing the insertion angle from 10° into 5°. The strength of polyaxial locking interfaces and mechanism of failure proved to be different among the examined plates.

Stabilization of fatigue fractures of the dorsal pelvis with a trans-sacral bar. Operative technique and outcome.

INTRODUCTION: Due to ageing of our population the number of fatigue fractures of the pelvic ring is steadily growing. These fractures are often treated with bed rest but may result in a disabling immobility with severe pain. An operative treatment is an option in these cases. The aim of operative treatment is bony healing obtained by stable fixation giving back to the patient's previous mobility. Optimal surgical treatment is currently under debate. Sacroiliac screw fixation and sacroplasty are used for stabilization of the dorsal pelvis. Due to the technique and the low density of spongious sacral bone, no or only low compression in the fracture site is obtained, which may inhibit bony healing. The trans-sacral bar compression osteosynthesis is presented as an alternative procedure. We present the outcome of 11 patients, who were treated with this method. METHODS: The patient is placed in prone position on the operation table. Under image intensifier control, a 5mm threaded sacral bar is inserted through the body of S1 from the left to the right dorsal ilium. Nuts are placed over the bar achieving fracture compression. When anterior pelvic instability is present, an anterior osteosynthesis is also performed. Clinical and radiological outcome were evaluated one year after index surgery with different scoring systems. RESULTS: Eleven patients (9 F and 2 M) were treated between 2005 and 2010. The mean age of the patients was 73 years at time of operation. There were no mechanical complications. Postoperatively there was a temporary nerve palsy of L5 in one case. The mean follow-up was 14 months. In all patients, a bony healing of the dorsal pelvic ring was achieved. Seven patients showed a major clinical improvement, in four patients a moderate. CONCLUSIONS: Trans-sacral bar osteosynthesis is a promising method for stabilization of fatigue fractures of the pelvic ring. Only with this method, a high interfragmentary compression is achieved, independent of the quality of the spongious bone of the sacral body.

Volar fixed-angle plating of distal radius fractures: screws versus pegs--a biomechanical study in a cadaveric model.

OBJECTIVES: The purpose of this biomechanical study was to determine whether a multidirectional fixed-angle plate with locking screws or with locking pegs in the distal fragment would optimize fixation of Orthopaedic Trauma Association (OTA) type A3 distal radius fractures. METHODS: Eight pairs of fresh-frozen human distal radii were used. Extra-articular distal radius fractures were created and stabilized with a multidirectional volar fixed-angle plate. The radii were randomized into 2 matched-paired groups. The distal fragment in Group I was stabilized with 7 locking screws. The distal fragment in Group II was fixed with 7 locking pegs. The proximal fragment in both groups was fixed with 3 screws. The specimens were tested under torsion and axial compression during static and cyclic tests. Finally, load-to-failure tests were performed under torsion. RESULTS: After 1000 cycles, 99% of the median torsional stiffness remained in the group using screws, whereas only 76% of the median stiffness under torsion remained in the group using pegs (P = 0.018). Under axial compression, median stiffness remained at 93% in the group using screws after 1000 cycles compared with a median of 0% in the group using pegs (P = 0.018). CONCLUSIONS: This biomechanical study showed a statistically significant difference between the locking screw and locking smooth peg configuration with regard to stiffness of the constructs after 1000 cycles. The use of locking screws as opposed to smooth locking pegs for OTA type A3 extra-articular distal radius fractures optimizes construct stability.

Intramedullary nailing vs. palmar locked plating for unstable dorsally comminuted distal radius fractures: a biomechanical study.

BACKGROUND: The purpose of this study was to compare the stability of a 2.4mm palmar locking compression plate and a new intramedullary nail-plate-hybrid Targon DR for dorsally comminuted distal radius fractures. METHODS: An extraarticular 10mm dorsally open wedge osteotomy was created in 8 pairs of fresh frozen human radii to simulate an AO-A3-fracture. The fractures were stabilized using one of the fixation methods. The specimens were loaded axially with 200 N and dorsal-excentrically with 80 N. 2000cycles of dynamic loading and axial loading-to-failure were performed. FINDINGS: Axial loading revealed that intramedullary osteosynthesis (Targon DR: 369 N/mm) was significantly (p=0.017) stiffer than plate osteosynthesis (Locking compression plate: 131 N/mm). With 214 N/mm the intramedullary nail also showed higher stability during dorsal excentric loading than the Locking compression plate with 51 N/mm (p=0.012). After 2000 cycles of axial loading with 80 N the Targon DR-group was significantly stiffer than the Locking compression plate-group under both loading patterns. Neither group showed significant changes in stiffness after 2000 cycles. Under dorsal excentric loading the Targon DR-group was still significantly stiffer with 212 N/mm than the Locking compression plate-group with 45 N/mm (p=0.012). The load to failure tests demonstrated higher stability of intramedullary nailing (625 N) when compared to plate osteosynthesis (403 N) (p<0.025). INTERPRETATION: The study shows that intramedullary fixation of a distal AO-A3 radial fracture is biomechanically more stable than volar fixed-angle plating under axial and dorsal-excentric loading in an experimental setup.

Locking reconstruction double plating of distal humeral fractures: how many screws in the distal ulnar column segment in A3 fracture provide superior stability? A comparative biomechanical in vitro study.

OBJECTIVES: Two 90-degree configurations of locking reconstruction plates with different numbers of screws in the distal ulnar column segment of distal extra-articular humeral fractures with metaphyseal comminution (A3) were biomechanically investigated. METHODS: Eight pairs of fresh-frozen human humeri were used. For paired comparison, the humeri were divided into 2 randomized groups. In both groups, double-plate osteosyntheses with locking reconstruction plates were performed in 90-degree configurations. In group 1, the posteriorly placed radial column plate exceeded the capitellum and the ulnar column plate extended into the ulnar sulcus. The ulnar plate was molded around the medial epicondyle and fixed with 3 short angular stable screws distally. In group 2, the posteriorly placed radial column plate was applied analogous to group 1. The locking reconstruction plate placed on the ulnar column was used reaching to the ulnar epicondyle, fixed with 1 long, angular, stable screw in the distal fragment. Stiffness testing for axial load and bending in static and cyclic tests were performed. In static test mode, a load was applied with a frequency of 0.1 Hz. For cyclic loading conditions, a load was applied at 1 Hz for 5000 cycles. RESULTS: All tested specimens adequately resisted simulated physiologic loading conditions with no failure. Comparable stiffness values for axial load (P = 0.161) and significant lower stiffness values for bending (P = 0.017) in group 2 under static bending conditions were found. Considering cyclic loading conditions, no significant alterations in stiffness in each group under axial load occurred. In bending conditions, stiffness values for group 2 were significantly lower than that for group 1 (P = 0.036). CONCLUSIONS: Under static and cyclic bending conditions, stiffness in group 2 was significantly lower than that in group 1. Nevertheless, both implant configurations showed no failure of the constructs. Based on these data, when applying locked plates in the clinical setting, more than 1 locked screw applied into the distal ulnar column of the articular segment is recommended.