Longitudinal measurement of tibial motion relative to the femur during passive displacements in the cat before and after anterior cruciate ligament transection

Passive anterior-posterior displacement and medial-lateral rotation of the tibia on the femur in the feline knee were assessed before transection of the anterior cruciate ligament, immediately after transection, and 2 and 4 months after transection. Four anaesthetized experimental and three sham-operated control animals were positioned in a stereotaxic frame. Motions of the tibia relative to the femur were measured with use of 60-Hz video motion analysis, while a strain-gauged system allowed measurement of forces and moments applied to the tibia. Displacement at 15 N of anterior force and 30° of knee flexion increased by an average of 6 mm following transection, and stiffness decreased by an average of 6 N/mm. At 2 and 4 months following transection, there were statistically significant reductions in this abnormal displacement. Stiffness during anterior displacement of the tibia at 30° increased significantly from immediately after transection to 4 months. At 90°, mean anterior displacement decreased from 5.1 mm immediately after transection to 2.9 mm at 4 months. Media rotation at 30° of knee flexion was significantly decreased from a mean of 16.5° after transection to a mean of 10.7° at 4 months. Changes in medial rotation at 90°, lateral rotation at 90°, and lateral rotation at 30° were not statistically significant. These results indicate a significant change in secondary constraints to tibial motion in response to knee instability.     

Effects of External Rotation on Anteroposterior Translations in the Shoulder: A Pilot Study

Background

Using physical examination to make the diagnosis of shoulder instability can be difficult, because typical examination maneuvers are qualitative, difficult to standardize, and not reproducible. Measuring shoulder translation is especially difficult, which is a particular problem, because measuring it inaccurately may result in improper treatment of instability.

Questions/purposes

The objective of this study was to use a magnetic motion tracking system to quantify the effects of external rotation of the abducted shoulder on a simulated simple translation test in healthy subjects. Specifically, we hypothesized that (1) increasing external rotation of the abducted shoulder would result in decreasing translation; (2) intraobserver repeatability would be less than 2 mm at all external rotation positions; and (3) mean side-to-side differences would be less than 2 mm at all external rotation positions.

Methods

The intraobserver repeatability and side-to-side differences of AP translation were quantified with a noninvasive magnetic motion tracking system and automated data analysis routine in nine healthy subjects at four positions of external rotation with the arm abducted. A shoulder positioning apparatus was used to maintain the desired arm position.

Results

No differences in translations between the positions of external rotation were found (p = 0.48). Intraobserver repeatability was 1.1 mm (SD, 0.8 mm) and mean side-to-side differences were small: 2.7 mm (SD, 2.8 mm), 2.8 mm (SD, 1.8 mm), 2.5 mm (SD, 1.8 mm), and 4.0 mm (SD, 2.6 mm) at 0°, 20°, 40°, and 60° of external rotation, respectively.

Conclusions

The intraobserver repeatability was strong and the side-to-side differences in translation were small with the magnetic motion tracking system, which is encouraging for development of an improved quantitative test to assess shoulder translation for fast and low-cost diagnosis of shoulder instability.

Clinical Relevance

Clinicians may not have to position the contralateral, normal, abducted shoulder in precisely the same position of external rotation as the injured shoulder while performing side-to-side comparisons.     

Variability of tunnel positioning in ACL reconstruction

Introduction

Since tunnel positioning is one of the key factors in anterior cruciate ligament (ACL) reconstruction and the variability of tunnel positioning in ACL reconstruction has so far never been analyzed, the objective of this study was to determine the inter- and intra-observer variability of tibial and femoral tunnel positioning in ACL reconstruction.

Materials and methods

In an operating room setup, 13 surgeons were asked to identify the tunnel positions in one and the same ACL-deficient cadaver knee. Using a fluoroscopic based ACL navigation system, tunnel positions were digitally measured in a test/re-test scenario. For variability analysis mean positions, standard deviations and range were calculated as well as differences between test/re-test positions.

Results

The intraobserver analysis showed a tibial variability of 3.3 mm (SD 2.1, range 7.5 mm) and a femoral variability of 2.0 mm (SD 1.6 mm, range 6.8 mm). The interobserver variability of the tibial tunnel positions was 3.2 mm (SD) with a range of 18.3 mm and a femoral variability of 3.7 mm (SD) with a range of 13.2 mm.

Conclusions

This study demonstrates that a reasonable inter- and intra-observer variability in ACL tunnel positioning exists even among experienced surgeons. Although deviations of 2–3 mm may seem to be acceptable at first sight, a range of up to 18.3 mm indicates that outliers exist, which can cause graft failure. More reliable reconstruction techniques should be developed to reduce the variability in tunnel positioning.     

Low inter- and intraobserver variability allows for reliable tunnel measurement in ACL reconstruction using the quadrant method

Introduction

Correct anatomic tunnel positions are essential in anterior cruciate ligament (ACL) reconstruction. To establish recommendations for tunnel positioning based on anatomical findings and to compare tunnel positions with clinical results, different radiological measurement methods as the quadrant method exist. Comparing the data of different observers requires the validation of the reliability of measurement methods. The purpose of this study therefore was to determine the reliability of the quadrant method to measure tunnel positions in ACL reconstruction. The hypothesis was, that the quadrant method shows a low inter- and intraobserver variability.

Materials and methods

In a test/retest scenario 20 knee surgeons were asked to determine defined tunnel positions in five lateral radiographs applying the quadrant method. Rotation, angle deviation, height and depth of the quadrant as well as absolute and relative tunnel positions of each observation were measured along referenced scales. Mean sizes and angle deviations of the quadrants, tunnel positions and deviations between the test/retest positions were calculated as well as standard deviations and range.

Results

Interobserver variability analyses, to plan as well as to determine tunnel positions in ACL reconstruction, showed a mean variability (SD) of <1 mm, with ranges of 2.5 mm for planning and 3.7 mm for determination of tunnel positions using the quadrant method. Intraobserver analysis showed mean variability with deviations of <1 mm and maximum standard deviations of 0.7 mm and ranges of up to 2.3 mm.

Conclusions

We confirmed the hypothesis that the quadrant method has a low inter- and intraobserver variability. Based on the presented validation data, the quadrant method can be recommended as reliable method to radiographically describe insertion areas of the ACL as well as to determine tunnel positions in ACL reconstruction intra and postoperatively.     

Anatomic Locking Plate for Displaced Intraarticular Calcaneal Fracture: Design and Application

Calcaneal fracture can lead to long-term disability and have a considerable economic effect. Most calcaneal fractures are intraarticular fractures involving the posterior facet of the subtalar joint. Treating displaced intraarticular calcaneal fractures is complicated because of the lack of an optimal treatment option. Internal fixation typically involves screw-and-plate implants, which can be unfavorable owing to the lack of an anatomic design and the intraoperative bending required for the plate to contour to the irregular surface of the calcaneus. We assessed the outcomes of 30 patients treated using innovative, anatomically designed calcaneal locking plates and the perceived advantages for surgeons. Postoperative computed tomography images of the affected feet were obtained, and the functional performance was recorded. The mean average Böhler angle had increased significantly from 16.8° ± 14.9° to 28.5° ± 9.4° (p < .001). The mean average maximal fracture gap and maximal step-off in the posterior facet of the subtalar joint in the coronal computed tomography images also decreased significantly from 2.8 ± 3.7 mm to 0.8 ± 1.3 mm (p < .01) and from 3.3 ± 2.8 mm to 0.8 ± 1.2 mm (p < .001), respectively. The mean average American Orthopaedic Foot and Ankle Ankle-Hindfoot scale score was 93.9 ± 7.1 at the final follow-up visit. In addition, the surgical time was reduced because bending the plate was not required and the quality of reduction could be assessed easily by examining the gap between the cortex and the plate. The results were promising, revealing that the anatomic locking plate can be used effectively in the treatment of displaced intraarticular calcaneal fractures using simple reduction techniques with a potentially shortened operating time.     

Volar long locking compression plate fixation for distal radius fractures with metaphyseal and diaphyseal extension

Comminuted distal radial fractures with metaphyseal and diaphyseal extension are uncommon and remain a challenge to treat. The purpose of this study was to assess the radiographic and functional outcomes of treatment with the volar long locking compression plate (LCP) system for distal radius fractures with metaphyseal and diaphyseal extension. This retrospective study was performed on 22 consecutive patients who were treated with open reduction and internal fixation with the application of a 2.4-mm-extra-long LCP volar distal radius plate. Patients were evaluated based on clinical signs and radiography studies. The average time to fracture union was 16 weeks. The volar tilt was restored to a mean of 10.1°. The radial length and radial inclination were restored to a mean of 12.8 mm and 23.6° at final follow-up, respectively. The mean loss of radial length was ?1.0 mm at final follow-up as compared with the contralateral extremity. The average ulnar variance was positive 0.1 mm at final follow-up with a congruent distal radioulnar joint. The degree of collapse after fixation between immediate postoperative and final follow-up visit was ?0.1 mm. Using the demerit-point system of the Gartland and Werley rating system, 14 results were rated as excellent, 5 as good and 1 as fair. DASH scores averaged 10.1 points. Based on our experience, the volar long LCP is useful in the management of comminuted fractures of the distal radius, in which there is proximal extension into the diaphysis and can avoid or minimize the complications of external fixation or dorsal bridging distraction plate.     

Surgical outcomes of retrograde nailing enhanced with minimally invasive cerclage cable fixation for infra-isthmal femoral fracture

BackgroundInfra-isthmal femoral fracture has been known as one of the risk factors for femoral nonunion. Retrograde intramedullary nailing can provide reliable stability of the distal fragment in infra-isthmal femoral fracture, but adequate reduction is required to achieve a successful outcome. This study aimed to evaluate the surgical outcomes of retrograde nailing enhanced with minimally invasive cerclage cable fixation for infra-isthmal femoral fracture.MethodsBetween March 2013 and July 2017, 15 patients with infra-isthmal fractures treated with retrograde nailing and minimally invasive cerclage cable fixation were included in this study. Cerclage cable was applied for reduction aid (reduction cable) or prevention of further displacement in non-displaced extension of the distal spiral fracture (prevention cable). Number and function of cerclage cables, operation time, additional surgery, and complications were assessed. Further displacement of the wedge after nailing, coronal and sagittal alignment, displacement of the main fragment, and time from injury to union were evaluated as radiologic outcomes.ResultsOf the 15 patients in this study, 14 were treated with reduction cables. Average postoperative coronal and sagittal angulation was 1.7° (1° varus to 4° valgus) and 1.6° (2° flexion to 11° extension). Mean displacement between the main fragments was 3.5 mm (range 0–22 mm). Four of the 14 cases used additional prevention cables combined with reduction cable. Only one case was treated solely with a prevention cable. A total of five prevention cables were maintained without further displacement. All patients achieved bone union, and the average time to union was 22.7 weeks (range 9–44 weeks). There were no complications as a result of surgery, such as infection or major neurovascular injury.ConclusionsThe minimally invasive cerclage cable technique could be a useful and safe enhancement in retrograde nailing for infra-isthmal femoral fracture in order to prevent further displacement and to reduce the main fracture.     

Minimally invasive treatment of displaced femoral shaft fractures with a teleoperated robot-assisted surgical system

BackgroundMinimally invasive surgical operation of intramedullary (IM) nailing is a standard technique for treating diaphyseal fractures. However, in addition to its advantages, there are some drawbacks such as the frequent occurrence of malalignment, physical fatigue and high radiation exposure to medical staff. The use of robotic and navigation techniques is promising treatments for femoral fractures.Materials and methodsThis paper presents a novel robot-assisted manipulator for femoral shaft fracture reduction with indirect contact with the femur. An alternative clinical testing model was proposed for orthopedic surgeons to practice femoral fracture reduction. This model imitates the human musculoskeletal system in shape and functional performance. The rubber tube simulate muscles providing contraction forces, and the silicone simulates passive elasticity of muscles. Two-group experiments were performed for studying feasibility of the teleoperated manipulator.ResultsThe average operative time was about 7 min. In the first group experiments, the femur axial, antero-posterior (AP) and lateral views mean errors were 2.2 mm, 0.7 mm and 1.1 mm, respectively, and their maximums were 3.0 mm, 0.9 mm and 1.5 mm; the mean errors of rotation were 0.8° around x-axis, 1.6° around y-axis, 2.0° around z-axis, and their maximums were 1.1°, 2.2°, 2.9°, respectively. For the second group experiments, the femur axial, AP and lateral views mean errors were 1.8 mm, 0.4 mm and 0.8 mm, respectively, and their maximums were 2.2 mm, 0.7 mm and 1.1 mm; the mean errors of rotation were 1.2° around x-axis, 1.6° around y-axis, 1.9° around z-axis, and their maximums were 2.4°, 1.8°, 2.7°, respectively. Reduction for AP view displacement is easier than lateral (p < 0.05) because of the tube-shaped anatomy and the muscle contraction forces. Errors around x-axis are smaller than those around y-, and z- axes (p<0.05), i.e., electro-mechanical actuator is easier to control than pneumatic.ConclusionAn experimental model for simulating human femoral characteristics was proposed. Experiments conducted on the artificial lower limb model demonstrated high reduction accuracy, safety, sufficient working space, and low radiation exposure of the proposed robot-assisted system. Thus, the minimally invasive teleoperated manipulator would have greater development prospect.     

Percutaneous screw fixation of acetabular fractures with 2D fluoroscopy-based computerized navigation

Introduction

The treatment of displaced acetabular fractures with formal open reduction and internal fixation has gained general acceptance. However, extensile exposure can lead to complications. Two-dimensional fluoroscopy-based computerized navigation for placement of percutaneous screw across non-displaced acetabular fractures has attracted interest by making use of stored patient-specific imaging data to provide real-time guidance in multiple image planes during implant placement. The purpose of the present study was to document early treatment results and complications associated with this new technique and evaluate its clinical application to displaced acetabular fractures amenable to closed or limited open reduction.

Materials and methods

Eighteen adult patients with 12 non-displaced and 8 displaced acetabular fractures were treated with percutaneous screw fixation under the guidance of a fluoroscopy-based navigation system. There were 14 men and four women with a mean age of 42.1 years (range 19–54 years). According to the AO and Orthopaedic Trauma Association Classification, there were nine 62-A3, five 62-B1, three 62-B2, and three 62-B3. The mean follow-up was 21 months (range 12–28 months). The mean time from injury to surgery was 4 days (range 2–7 days).

Results

A total of 30 acetabular screws were inserted, including 21 anterior column screws and 9 posterior column screws. The average operation time was 24.6 min (range 16–47 min) from the image acquisition to wound closure. The average fluoroscopic time was 28.4 s (range 11–58 s). Compared to the final position of the screw, the average deviated distance of wire tip was 2.5 mm (range 1.1–3.6 mm) and the average trajectory difference was 2.45° (range 1.5°–4.6°). Maximal gap displacement averaged 10 mm (range 2–22 mm) preoperatively and 3 mm (range 0–5 mm) postoperatively; while maximal step displacement averaged 4 mm (range 1–10 mm) preoperatively and 2 mm (range 0–4 mm) postoperatively. One patient sustained a transient femoral nerve palsy and resolved 2 months after the operation. No superficial or deep infection occurred. Using the rating system of D’Aubigne and Postel, 13 patients had excellent results, 4 patients had good results, and 1 patient had a fair result.

Conclusion

Percutaneous screw fixation of acetabular fractures with 2D fluoroscopy-based navigation could be applied not only to non-displaced fractures but also to displaced fractures amenable to closed or limited open reduction.     

Radiographic assessment of small finger metacarpal neck fractures

Treatment recommendations for metacarpal neck fractures of the small finger are generally based on the degree of apex dorsal angulation at the fracture site. We evaluated the variability of measurement of fracture angulation and the effect this variability has on treatment recommendations for these injuries. A total of 96 radiographs (anteroposterior, lateral, oblique views) of 32 patients with fractures of the small finger metacarpal neck were evaluated independently by 3 fellowship-trained orthopedic hand surgeons. Treatment recommendations for each fracture were tabulated. This process was repeated 6 weeks later to evaluate intraobserver variability. Kappa coefficients of inter- and intraobserver reliability of fracture angulation measurement and treatment plans were generated. The mean reliability coefficient of the measurement of fracture angulation between the 3 different observers was slight. Similarly, the reproducibility of fracture angulation measurement within observers was fair. Agreement between observers for appropriate treatment recommendations for each fracture was fair and agreement within observers for treatment was only slightly better. The measurement of fracture angulation of small finger metacarpal neck fractures seems to be subject to a high degree of inter- and intraobserver variability.     

Ipsilateral femoral neck and shaft fracture in children: a report of two cases and a literature review

Concomitant ipsilateral fractures of the neck and shaft of the femur in children are rare. The most recent report in this context found a total of only nine reported cases (<12 years of age) following a search of the indexed English literature. These injuries occur in children due to high-velocity trauma, and there is no generally accepted method of treatment. We report three additional cases from the literature and two cases of our own. In our cases, one had a residual 10° varus deformity at the subtrochanteric level in the femur, but this did not affect hip function. Another patient exhibited a limp at final follow-up due to leg length discrepancy, and peroneal nerve palsy at the time of injury. We advocate operative stabilization of the femoral shaft fracture first to reduce the risk of further displacement and simplify the subsequent reduction of the femoral neck. The series shows that these rare injuries have a poor prognosis, with high rates of incidence of avascular necrosis, coxa vara, and leg length discrepancy.     

固定平台后稳定型假体全膝关节置换术后的运动学研究

 目的 探讨固定平台后稳定型假体全膝关节置换(total knee arthroplasty,TKA)术后膝关节在负重屈膝下蹲时的运动学特征。方法 选取10名健康志愿者和10例固定平台后稳定型假体TKA术后患者。制作骨骼及膝关节假体三维模型,在持续X线透视下完成负重下蹲动作,膝关节屈曲度每增加15°截取一幅图像。通过荧光透视分析技术完成三维模型与二维图像的匹配,再现股骨与胫骨在屈膝过程中的空间位置,通过连续的图像分析比较正常与固定平台后稳定型假体TKA术后膝关节在负重下蹲时股骨内、外髁前后移动及胫骨内外旋转幅度。结果 负重下蹲时,正常膝关节平均屈曲136°,股骨内、外髁分别后移(7.3±1.2) mm和(19.3±3.1) mm,胫骨平均内旋23.8°±3.4°;TKA术后膝关节平均屈曲125°,股骨内、外髁分别后移(1.4±1.6) mm和(6.4±1.7) mm,胫骨平均内旋8.5°±3.4°。结论 固定平台后稳定型假体TKA术后膝关节运动与正常膝关节相似,均表现出股骨内、外髁后移及胫骨内旋运动,但幅度小于正常膝关节,且在屈膝过程中存在股骨矛盾性前移及胫骨外旋现象。     

Biological fixation of fracture shaft femur in children

The aim of this work was to assess the results of biological fixation of fracture shaft femur in children with locked plates. Twenty-eight fractures in 26 children with closed fractures of the shaft of the femur were managed with biological plating using locked plates bridging the fracture site applied submuscularly through two small incisions above and below the fracture site. The mean age of the patients was 11.2 years; all patients had radiological union within a mean time of 11.9 weeks (8–14 weeks); the average follow-up was 31 months (14–40 months). No patient had frontal or sagittal plane deformity more than 10° or limb length discrepancy more than 1.5 cm. There was no infection, delayed union, nonunion or clinically evident malrotation. A significant positive correlation between the age and the time to healing (p = 0.03) was detected, whereas there was no significant correlation between time to healing and patient sex, fracture level, fracture type, mechanism of injury. Also there was no significant correlation between limb length discrepancy and patient age, sex, fracture level, fracture type, and mechanism of injury. Biological fixation of fractures of the femoral shaft in children with locked plates is a reliable method of fixation with excellent healing potential and fixation mechanics without complications.     

Accuracy of radiographs in assessment of displacement in lateral humeral condyle fractures

Purpose

Determining the magnitude of displacement in pediatric lateral humeral condyle fractures can be difficult. The purpose of this study was to (1) assess the effect of forearm rotation on true fracture displacement using a cadaver model and to (2) determine the accuracy of radiographic measurements of the fracture gap.

Methods

A non-displaced fracture was created in three human cadaveric arms. The specimens were mounted on a custom apparatus allowing forearm rotation with the humerus fixed. First, the effect of pure rotation on fracture displacement was simulated by rotating the forearm from supination to pronation about the central axis of the forearm, to isolate the effects of muscle pull. Then, the clinical condition of obtaining a lateral oblique radiograph was simulated by rotating the forearm about the medial aspect of the forearm. Fracture displacements were measured using a motion-capture system (true-displacement) and clinical radiographs (apparent-displacement).

Results

During pure rotation of the forearm, there were no significant differences in fracture displacement between supination and pronation, with changes in displacement of <1.0 mm. During rotation about the medial aspect of the forearm, there was a significant difference in true displacements between supination and pronation at the posterior edge (p < 0.05).

Conclusion

Overall, true fracture displacement measurements were larger than apparent radiographic displacement measurements, with differences from 1.6 to 6.0 mm, suggesting that the current clinical methods may not be sensitive enough to detect a displacement of 2.0 mm, especially when positioning the upper extremity for an internal oblique lateral radiograph.     

Surgical Management of Fifth Metatarsal Diaphyseal Fractures: A Retrospective Outcomes Study

Fifth metatarsal diaphyseal fractures are a common injury treated by foot and ankle surgeons. The limited data on this specific fracture type has promoted nonoperative treatment with immobilization. The primary objective of the present study was to record the radiographic healing time of fifth metatarsal diaphyseal fractures after surgical intervention and present the specific fracture characteristics. The medical records of a series of 64 patients with surgically managed fifth metatarsal diaphyseal fractures were retrospectively reviewed. The data collected consisted of radiographic healing times, fracture characteristics, and patient demographics. The mean average age at injury was 49.23 ± 15.35 years with greatest incidence in females at 73.44%. The mean healing time was 7.73 ± 4.74 weeks, with an overall complication rate of 6.25%. The fractures were classified into 2 specific categories according to the anatomic location. Type I fractures occurred in a significantly older population, were significantly longer in length, and healed faster. The mean displacement and angulation at injury was 3.20 ± 1.22 mm, and 5.89° ± 4.60°, respectively, for all fractures. Of the 64 patients, 1 (1.56%) experienced nonunion, 2 (3.13%) delayed unions, and no malunions. One patient (1.56%) underwent repeat operation for hardware removal. One case (1.56%) of superficial postoperative infection developed and was treated with oral antibiotics. We observed good surgical outcomes with minimal postoperative complications. We also identified 2 specific entities of fifth metatarsal diaphyseal fractures. On the basis of our results, we advocate surgical intervention even for minimally displaced diaphyseal fractures to maintain even weightbearing across the metatarsal parabola.     

Can Anatomic Measurements of Stem Anteversion Angle Be Considered as the Functional Anteversion Angle?

Background

Stem anteversion angle is important in the combined anteversion theory to avoid implant impingement after total hip arthroplasty (THA). However, anatomic measurements of stem anteversion angle may not represent functional anteversion of the femur if the femur undergoes axial rotation. Herein, the femoral rotational angle (FRA) was measured in supine and standing positions before and after THA to evaluate the difference between anatomic and functional measurements.

闭合或有限切开经皮穿针固定治疗肱骨近端两部分骨折

目的：通过分析28例闭合或有限切开经皮穿针固定治疗肱骨近端两部分骨折的临床疗效，探讨治疗体会及教训。方法：2005年11月至2006年11月采用闭合或有限切开经皮穿针固定治疗肱骨近端两部分骨折28例，男12例，女16例；年龄31-73岁，平均54．7岁。均为新鲜骨折。骨折根据Neer分型：两部分外科颈骨折18例，外展嵌插两部分大结节骨折10例。结果：本组平均手术时间42min,口均Ⅰ期愈合，X线片显示骨折对位满意，向前成角基本矫正。外展嵌插两部分大结节骨折的颈干角从术前的平均175°（160°-200°）恢复至平均136°（128°～142°），大结节移位小于3mm。随访6-13个月，平均10．3个月，骨折均愈合，未出现肱骨头缺血坏死现象，术后8—10周取出内固定。根据ASES及Constant-Murley肩关节评分系统，本组ASES评分平均91．2分（63～100分），Constant—Mudey评分平均90．4分（67-100分）。本组优12例，良14例，一般2例。结论：闭合或有限切开经皮穿针固定治疗肱骨近端两部分骨折的操作有相当难度，且须在透视下进行，但具有损伤小、康复快的优点，是治疗特定类型肱骨近端骨折的有效方法。骨质情况是决定固定稳定程度的必要条件。     

Assessment of return to play in professional overhead athletes subjected to arthroscopic repair of rotator cuff tears and associated labral injuries using the Italian version of the Kerlan-Jobe Orthopedic Clinic Shoulder and Elbow score

Background

Multiple landmarks including the transepicondylar axis (TEA), posterior condylar axis (PCA) and anterior trochlear line (TL) have been used to set up the femoral component rotation, but each is faced with its own practical obstacle that limits its usage. Also a common practice is to set the femoral component rotation at 3° external rotation to PCA and valgus resection angle at 5°–7° to anatomical axis of femur. For the reason that the anatomy of each knee is different, it may not be justified to practice such a set protocol in all cases. The aim of the study was to compare the anatomical landmarks used to set up the femoral component rotation and to study the variability in the different anatomical relationships relevant to total knee replacement.

Materials and methods

The study had 52 patients (94 knees) with grade IV osteoarthritis. Full-length lower limb scanogram and 1 mm cross-sectional cuts of distal femur were taken. aTEA, sTEA, PCL, TL, CTA, PCA, TLA and valgus angles were taken for all knees.

Results

aTEA is identifiable in all cases but sTEA in only 59 knees (62.77%). Correspondingly, CTA is calculable in all knees and PCA in 62.77% cases. Mean CTA and mean PCA were 5.4° ± 1.88° SD and 0.71° ± 1.95° SD, respectively. Mean angle between aTEA and sTEA was 4.88. TL is a line difficult to draw because of high incidence of anterior osteophytes, making CTA a more reliable parameter than TLA. Mean TLA was 10.31° ± 3.52° SD. Mean valgus resection angle was 4.86° ± 2.53° SD. Gender- or side-based differences in any of these values were not statistically different.

Conclusions

Using aTEA or sTEA can make a big difference in femoral component rotation; therefore, whether aTEA or sTEA should be used needs to be further investigated. CTA, PCA and valgus resection angle need to be individually calculated for each knee. Use of TLA is not recommended.

     

Management of Intra-Articular Calcaneal Fractures: Clinical Results of Reduction Technique Using a Bone Spreader

The purpose of the present study was to examine the clinical results of surgery for intra-articular calcaneal fractures using a calcaneal locking plate and a bone spreader as a reduction tool. Ten patients with intra-articular calcaneal fractures were treated. An extended lateral approach was used. The reduction of the intra-articular fragments of the posterior facet was temporarily held using a bone spreader and Kirschner wires. Internal fixation was achieved with a locking calcaneal plate. Böhler's angle and Preiss' angle were assessed on the day of injury and the day of the final follow-up examination. The step off and gap of the posterior facet were assessed on the day of injury and the first week after surgery. The functional outcome was evaluated using the American Orthopaedic Foot and Ankle Society ankle hindfoot scale score. The mean Böhler's angle ranged from 2.1° ± 11.0° to 30.4° ± 5.0° (p < .0001), the mean Preiss' angle ranged from 23.5° ± 4.5° to 15.5° ± 2.9° (p < .0001), the mean step off ranged from 4.0 ± 1.9 mm to 0.1 ± 0.2 mm (p = .0002), and the mean gap ranged from 2.6 ± 1.0 mm to 1.2 ± 0.6 mm (p = .0035). The mean American Orthopaedic Foot and Ankle Society Ankle-Hindfoot scale score was 89.2 (range 85 to 100) at a mean of 14.3 months after surgery. Our results suggest that a locking calcaneal plate can be used to restore and reduce an intra-articular calcaneal fracture and achieve good clinical results.