Biomechanical Analysis of the Kirschner-Wire Depth of the Modified Tension Band Wiring Technique in Transverse Patellar Fractures: An Experimental Study Using the Finite-Element Method

Background@#Modified tension band wiring is one of the most preferred surgical methods for transverse patellar fractures. However, the optimal depth or sagittal position of a Kirschner wire (K-wire) in modified tension band wiring has yet to be determined.The purpose of this study was to evaluate whether the depth of a K-wire affects the biomechanical characteristics of modified tension band wiring using the finite-element method. @*Methods@#A patella model was designed with a cuboid shape (length, 34.3 mm; width, 44.8 mm; and thickness, 22.4 mm) and divided into the cortical and cancellous bone parts. A transverse fracture line was formed on the midline of the cuboid shape model.The cuboidal model was applied to modified tension band wiring. The depth or sagittal position of the K-wire was divided into superficial, center, and deep. With the Abaqus v2017 program (Dassault System Inc.), the distal part of the model was fixed, and a tensile load of 850 N was applied to the proximal part of the model at an angle of 45°. The maximum pressures of the cortical and cancellous bones at the fracture plane were measured. The largest von Mises values of the K-wire and stainless steel wire were also measured. The fracture gap on the distracted or anterior side was measured. @*Results@#In deep K-wire placement, the highest peak von Mises values of the cortical and cancellous bones were observed. The Kwire and stainless steel wire showed the highest von Mises values in deep K-wire placement. The fracture gap was also largest in deep K-wire placement. @*Conclusions@#The depth of the K-wire affects the biomechanical characteristics of modified tension band wiring. Deep placement of the K-wire will be more favorable for bone union than the empirically known 5-mm anterior or center placement of the K-wire.

Clinical Assessments and MRI Findings Suggesting Early Surgical Treatment for Patients with Medial Epicondylitis

Purpose@#To evaluate the MRI findings and clinical factors that are characteristic of patients who ultimately undergo surgery for medial epicondylitis. @*Materials and Methods@#Fifty-two consecutive patients who were diagnosed with medial epicondylitis and underwent an elbow MRI between March 2010 and December 2018 were included in this retrospective study. The patients’ demographic information, clinical data, and MRI findings were evaluated. All variables were compared between the conservative treatment and surgical treatment groups. Logistic regression analyses were conducted to identify which factors were associated with surgical treatment. @*Results@#Common flexor tear (CFT) tear size showed a statistically significant difference in both the transverse and longitudinal planes (p < 0.001, p = 0.013). The CFT abnormality grade significantly differed in both the transverse and longitudinal planes (p = 0.022, p = 0.003). A significant difference was also found in the medial collateral ligament abnormality (p = 0.025). Logistic regression analyses showed that only the transverse diameter of the CFT tear size (odds ratio:1.864; 95% confidence interval: 1.264–2.750) was correlated with surgical treatment. @*Conclusion@#Of patients diagnosed with medial epicondylitis, patients with a larger transverse CFT tear size tend to undergo surgical treatment ultimately.

Topographical measurement of the attachments of the central band of the interosseous membrane on interosseous crests of the radius and ulna

To suggest a reasonable isometric point based on the anatomical consistency of interosseous membrane (IOM) attachment in association with topographic characteristics of the interosseous crests, the footprints of the central band (CB) of the IOM on the radial and ulnar interosseous crests (RIC and UIC) were measured. Methods: We measured the distance from the CB footprints from each apex of both interosseous crests in 14 cadavers and the angles between the forearm axis of rotation (AOR) and the distal slopes of the RIC and UIC in 33 volunteers. Results: The CB footprints lay on the downslope of both interosseous crests with its upper margin on average 3-mm proximal from the RIC’s apex consistently in the radial length, showing normality (p>0.05), and on average 16-mm distal from the UIC’s apex on the ulna without satisfying normality (p0.05), and there was no side-to-side difference in both forearms (p<0.05). Conclusions: The CB attached to the downslope just distal to the RIC’s apex constrains the radius to the UIC that coincides with the AOR of the forearm circumduction, maintaining itself both isometrically and isotonically.

Clinical Assessments and MRI Findings Suggesting Early Surgical Treatment for Patients with Medial Epicondylitis

Purpose@#To evaluate the MRI findings and clinical factors that are characteristic of patients who ultimately undergo surgery for medial epicondylitis. @*Materials and Methods@#Fifty-two consecutive patients who were diagnosed with medial epicondylitis and underwent an elbow MRI between March 2010 and December 2018 were included in this retrospective study. The patients’ demographic information, clinical data, and MRI findings were evaluated. All variables were compared between the conservative treatment and surgical treatment groups. Logistic regression analyses were conducted to identify which factors were associated with surgical treatment. @*Results@#Common flexor tear (CFT) tear size showed a statistically significant difference in both the transverse and longitudinal planes (p < 0.001, p = 0.013). The CFT abnormality grade significantly differed in both the transverse and longitudinal planes (p = 0.022, p = 0.003). A significant difference was also found in the medial collateral ligament abnormality (p = 0.025). Logistic regression analyses showed that only the transverse diameter of the CFT tear size (odds ratio:1.864; 95% confidence interval: 1.264–2.750) was correlated with surgical treatment. @*Conclusion@#Of patients diagnosed with medial epicondylitis, patients with a larger transverse CFT tear size tend to undergo surgical treatment ultimately.

Biomechanical Analysis of the Kirschner-Wire Depth of the Modified Tension Band Wiring Technique in Transverse Patellar Fractures: An Experimental Study Using the Finite-Element Method

Background@#Modified tension band wiring is one of the most preferred surgical methods for transverse patellar fractures. However, the optimal depth or sagittal position of a Kirschner wire (K-wire) in modified tension band wiring has yet to be determined.The purpose of this study was to evaluate whether the depth of a K-wire affects the biomechanical characteristics of modified tension band wiring using the finite-element method. @*Methods@#A patella model was designed with a cuboid shape (length, 34.3 mm; width, 44.8 mm; and thickness, 22.4 mm) and divided into the cortical and cancellous bone parts. A transverse fracture line was formed on the midline of the cuboid shape model.The cuboidal model was applied to modified tension band wiring. The depth or sagittal position of the K-wire was divided into superficial, center, and deep. With the Abaqus v2017 program (Dassault System Inc.), the distal part of the model was fixed, and a tensile load of 850 N was applied to the proximal part of the model at an angle of 45°. The maximum pressures of the cortical and cancellous bones at the fracture plane were measured. The largest von Mises values of the K-wire and stainless steel wire were also measured. The fracture gap on the distracted or anterior side was measured. @*Results@#In deep K-wire placement, the highest peak von Mises values of the cortical and cancellous bones were observed. The Kwire and stainless steel wire showed the highest von Mises values in deep K-wire placement. The fracture gap was also largest in deep K-wire placement. @*Conclusions@#The depth of the K-wire affects the biomechanical characteristics of modified tension band wiring. Deep placement of the K-wire will be more favorable for bone union than the empirically known 5-mm anterior or center placement of the K-wire.

Anterior Dislocation of the Radial Head Combined with Plastic Deformity of the Ulnar Shaft in an Adult: A Case Report

A 25-year-old woman presented to the emergency room with a painful and swollen right forearm. She had just sustained an injury from an accident during which her arm was tightly wound by a rope as she was lowering a net from a fishing boat. Before being released, her arm was rigidly trapped in the rope for approximately ten minutes. Radiographs revealed anterior dislocation of the radial head that was accompanied by plastic deformation of the proximal ulna, manifested as a reversal of the proximal dorsal angulation of the ulna (PUDA); suggested a Monteggia equivalent fracture. With the patient under general anesthesia, we reduced the radial head by posterior compression at 90° of elbow flexion and at neutral rotation of the forearm. However, the reduction was easily lost and the elbow re-dislocated with even slight supination or extension of the arm. After the osteotomy of the ulnar deformity to restore the PUDA to normal, the reduction remained stable even with manipulation of the arm. We found that the patient could exercise a full range of motion without pain at the 3-month follow-up, and neither residual instability nor degenerative changes were observed at the final 3-year follow-up.

Surgical Treatment of Clavicle Midshaft Fractures Using a Locking Compression Plate: Conventional Open Reduction and Plating with Internal Fixation versus Minimal Invasive Plate Osteosynthesis / 대한정형외과학회잡지

PURPOSE: The purpose of this study was to make a comparison between minimally invasive plate osteosynthesis (MIPO) and conventional open reduction and plating (COP) to treat displaced clavicle shaft fractures. MATERIALS AND METHODS: We retrospectively reviewed patients with clavicle shaft fractures, who underwent surgery by using a locking plate between May 2011 and August 2016. The inclusion criteria were: 1) displaced ≥20 mm, 2) acute fracture of less than 2 weeks from injury, 3) skeletally mature patients, and 4) follow-up of at least 6 months. The demographic data and clinical outcomes, including operation time, fracture union rate, union time, shortening of clavicle, shoulder functional score (University of California at Los Angeles score), and complications, were evaluated. The clavicle length ratio was measured to evaluate shortening. We compared the clinical outcomes between two groups: the COP group that included 21 patients treated with COP (group 1) and the MIPO group that included 19 patients treated with MIPO (group 2). RESULTS: In all cases, union of fractures was successfully achieved. The mean union time was 14.9 weeks in group 1 and 14.2 weeks in group 2 (p=0.713). Both groups had good functional scores (34.0 vs. 33.7, p=0.658). Group 2 had shorter operation time and less bleeding. There were no secondary interventions or infections. The clavicle length ratio was similar between the two groups; and all patients in both groups showed no shortening (less than 3%). There were no implant failures in either group. CONCLUSION: The clinical and radiologic outcomes were satisfactory in both groups. We suggest that MIPO may be a safe and effective method for displaced clavicle shaft fractures.

Evaluation of Clinical Applicability of Stress Radiography for Shoulder Instability: Correlation between the Degree of Displacement and the Physical Examinations / 대한정형외과학회잡지

PURPOSE: The purpose of this study is to examine the clinical applicability of stress radiography in patients presenting with shoulder instability. MATERIALS AND METHODS: Fifty-six patients diagnosed with shoulder instability and 20 healthy volunteers participated in the study. Degree of displacement of the humeral head as measured on stress radiography using a Telos GA-IIE device was compared with the results of the physical examinations. Four types of stress radiography were captured while applying 15 daN of force anteriorly (AER0 and AER60) and posteriorly (PER0 and PER60) at two different positions: (1) 90° of abduction combined with 0° of external rotation, and (2) 90° of abduction combined with 60° of external rotation. RESULTS: The degree of displacement of affected shoulders of 44 patients showed significantly larger displacement than normal shoulders (p<0.05), and the comparison between 56 affected shoulders of the patients and 40 normal shoulders of the volunteers showed significantly larger displacement only in PER0 and PER60 of the patients (p<0.05). Among the four radiographs of affected shoulders, AER60 showed significantly less displacement (p=0.046). The anterior drawer test under anesthesia of 16 patients who underwent surgery for anterior instability showed positive correlation with AER0 (Spearman's rho=0.56, p<0.024). Significantly larger anterior displacement of the load and shift test was observed in the subgroup with anterior displacement more than 3 mm (p=0.028), and higher positive frequency of the Kim's test was observed in the subgroup with posterior displacement more than 3 mm (p=0.005). CONCLUSION: Stress radiography using a Telos GA-IIE device could discriminate the affected shoulder. Although it could not replace individual physical examinations, the degree of displacement correlates with some physical examinations for shoulder instability.