Prevention of progression of osteoarthritis knee. Is it possible?

Knee joint is an organ made up of joining of two long bones and supported by joint capsule, ligaments and menisci which is moved by muscles. It helps in locomotion. As many physicians thought osteoarthritis of knee is not a degenerative disease but failed attempt of the joint to repair the mechanically induced damage caused by abnormal intraarticular stress. Normalization of this stress is shown to result in structural and symptomatic improvement. Progression of osteoarthritis can be prevented by strengthening of bone and muscles and also by correcting the altered mechanical axis. Strength of bone and muscles is the strength of joint.

Bone alignment after minimally invasive plate osteosynthesis of the tibia in dogs / Avaliação do alinhamento ósseo após osteossíntese minimamente invasiva com placa de tíbia em cães

ABSTRACT: This study assessed radiographically changes in tibial alignment in the frontal and sagittal planes in dogs that underwent minimally invasive plate osteosynthesis (MIPO) without the aid of image intensifiers. Radiographs of dogs with complete non-articular tibial fractures submitted to MIPO were included and evaluated, without the aid of a transoperative image intensifier and / or an association of implants. The tibial mechanical angles (mMPTA, mMDTA, mCaPTA and mCrDTA) were measured by three evaluators. The data obtained were compared with results from previously published studies. Twenty-seven animals were included in the study. The mean and standard deviation of the angular changes were as follows: mMPTA, 2.54° ± 3.10 (-1.1º to 8.7º); mMDTA, 0.03º ± 0.16 (-3.44º to 0.79º); mCaPTA, 37º ± 4.29 (-6.23º to 14.87º); and mCrDTA, 8.25° ± 5.53 (-0.2º to 17.28º). There was a negative correlation between "mCaPTA" and "mCrDTA". MIPO of the tibia without using image intensifiers and implant association can potentially cause angular changes, which can lead to clinically relevant deformities after bone healing.

RESUMO: Este estudo teve como objetivo avaliar radiograficamente as alterações no alinhamento da tíbia nos planos frontal e sagital em cães submetidos à osteossíntese minimamente invasiva com placa (MIPO) sem o auxílio de intensificadores de imagem. Foram incluídas e avaliadas radiografias de cães com fraturas completas da tíbia não articulares submetidos a MIPO, sem o auxílio de intensificador de imagem transoperatório e/ou associação de implantes. Os ângulos mecânicos tibiais (mMPTA, mMDTA, mCaPTA e mCrDTA) foram mensurados por três avaliadores. Os dados obtidos pela média de todas as avaliações foram comparados com resultados de estudos previamente publicados. Vinte e sete animais foram incluídos no estudo. A média e desvio padrão das alterações angulares foram os seguintes: mMPTA= 2,54° ± 3,10 (-1,1º a 8,7º); mMDTA= 0,03º ± 0,16 (-3,44º a 0,79º); mCaPTA= 37º ± 4,29 (-6,23º a 14,87º); e mCrDTA= 8,25 ° ± 5,53 (-0,2º a 17,28º). Houve uma correlação negativa entre "mCaPTA" e "mCrDTA". A realização de MIPO em tíbia sem o uso de intensificadores de imagem e associação de implantes pode causar alterações angulares, o que pode levar a deformidades clinicamente relevantes após a cicatrização óssea.

Comparison of Mechanical Axis and Dynamic Range Assessed with Weight Bearing Radiographs and Navigation System in Closed Wedge High Tibial Osteotomy

PURPOSE: To compare navigation and weight bearing radiographic measurements of mechanical axis (MA) before and after closed wedge high tibial osteotomy (HTO) and to evaluate post-osteotomy changes in MA assessed during application of external varus or valgus force. MATERIALS AND METHODS: Data from 30 consecutive patients (30 knees) who underwent computer-assisted closed-wedge HTO were prospectively analyzed. Pre- and postoperative weight bearing radiographic evaluation of MA was performed. Under navigation guidance, pre- and post-osteotomy MA values were measured in an unloaded position. Any change in the post-osteotomy MA in response to external varus or valgus force, which was named as dynamic range, was evaluated with the navigation system. The navigation and weight bearing radiographic measurements were compared. RESULTS: Although there was a positive correlation between navigation and radiographic measurements, the reliability of navigation measurements of coronal alignment was reduced after osteotomy and wedge closing. The mean post-osteotomy MA value measured with the navigation was 3.5°±0.8° valgus in an unloaded position. It was 1.3°±0.8° valgus under varus force and 5.8°±1.1° valgus under valgus force. The average dynamic range was >±2°. CONCLUSIONS: Potential differences between the postoperative MAs assessed by weight bearing radiographs and the navigation system in unloaded position should be considered during computer-assisted closed wedge HTO. Care should be taken to keep the dynamic range within the permissible range of alignment goal in HTO.

Coronal Alignment of the Lower Limb and the Incidence of Constitutional Varus Knee in Korean Females

PURPOSE: In total knee arthroplasty (TKA), it is important to restore neutral mechanical alignment. The purpose of this study was to assess whether the lower limb alignment is neutral in healthy Korean females and investigate the incidence of constitutional varus knees among them. MATERIALS AND METHODS: Weight-bearing full-leg standing radiographs were obtained from 118 healthy females between the ages of 20 to 39 years. One radiologist and two orthopaedic surgeons measured the hip-knee-ankle angle (HKAA), medial proximal tibial angle (MPTA), and femoral anatomic mechanical angle (FAMA) on the radiographs and compared with the traditional gold standard HKAA of 0degrees, MPTA of 3degrees varus, and FAMA of 6degrees. RESULTS: The interobserver reliability of the three independent observers was high (p<0.001). The HKAA of the study subjects (1.35degrees+/-2.04degrees) was significantly different from the standard HKAA of 0degrees (p<0.001), but no statistically significant difference was observed in the MPTA (-3.18degrees+/-1.61degrees) and FAMA (5.99degrees+/-0.70degrees) from the standard values (p=0.083 and p=0.887, respectively). The incidence of constitutional varus alignment was 20.34%. CONCLUSIONS: In Korean females, the mechanical axis of the lower limb was not neutral and the incidence of constitutional varus alignment was slightly higher than that in Western females. We believe that these findings should be taken into consideration in planning reconstructive surgery of the knee, such as TKA, unicompartmental knee arthroplasty, and high tibial osteotomy.

Clinical Outcome of IM-Guided Total Knee Arthroplasty with Inappropriate Femoral Resection in Coronal Plane

PURPOSE: The purpose of this study was to evaluate clinical results and accuracy of femoral cutting in the coronal plane in total knee arthroplasty (TKA) using a fixed length intramedullary guide. MATERIALS AND METHODS: From 2005 to 2008, 101 patients (154 knees) underwent TKA (NexGen LPS implant). The minimal follow-up period was 3 years (mean, 4.4 years). The patients were divided into two groups (group 1, 94alpha, 98 or =2degrees MAD was 65 in group 1 and 24 in group 2. The mean PTA, KSKS, and KSFS were 10.17degrees, 96.0, and 96.6, respectively, in group 1 and 11.58degrees, 84.5, and 85.5, respectively, in group 2. CONCLUSIONS: The percentage of coronal alignment outliers was relatively high (34 in 154 cases, 22%) after TKA using a fixed length intramedullary guide. However, there was no statistically significant intergroup difference in clinical results (KSKS, p=0.67; KSFS, p=0.56).

Intramedullary internal fixation for the treatment of fibrous dysplasia of proximal femur combined with coxa varus deformity / 中国组织工程研究

10.3969/j.issn.2095-4344.2013.26.008

Radiographic Analysis of Tibial-Articular Surface Angle According to the Selection of the Mechanical Axis / 대한족부족관절학회지

PURPOSE: We investigated a statistical difference of tibial-articular surface (TAS) angles between radiographs of standing ankle anteroposterior (AP) and whole lower extremity view, and evaluated whether the tibial axis obtained from the standing ankle AP view reflects the original mechanical axis of lower extremity. MATERIALS AND METHODS: Both the standing ankle AP and whole lower extremity view were taken from 60 legs of 30 healthy volunteers without a history of ankle surgery or deformity of lower limb. To determine the tibial axis, Takakura's and Hintermann's method were employed in the standing ankle AP view. To compare these results with the original TAS angle, ANOVA and multiple comparison test were used. RESULTS: The mean TAS angle was 88.3 degrees(from hip joint to ankle), 89.5 degrees (from knee joint to ankle), 88.5 degrees (Takakura's method), and 90.2 degrees(Hintermann's method). Although there was a statistical significance (p=0.000) between these results, Takakura's method had no significant difference, compared to the results of whole extremity view by the multiple comparison test. CONCLUSION: The tibial axis obtained by Takakura's method reflects the original mechanical axis of lower extremity. When a surgical procedure is planned, however, it is necessary to consider that the ankle radiographs do not provide any information on the proximal deformity without the whole lower extremity view.

Easy Identification of Mechanical Axis during Total Knee Arthroplasty

PURPOSE: We devised an intraoperatively identifiable mechanical axis (IIMA) as a reference of alignment in total knee arthroplasty (TKA). MATERIALS AND METHODS: Between February 2010 and January 2011, primary TKAs were consecutively performed on 672 patients (1007 knees) using an IIMA as a reference in the coronal plane. RESULTS: The alignment of the lower extremity improved from a mean of 11.4+/-6.7degrees (-10.3-34.4degrees) of varus preop. to 0.7+/-3.5degrees (-5.2-8.6degrees) immediately after surgery. Mean alignment of the femoral component in the coronal plane was 89.3+/-2.3degrees (83.4-97.2degrees) postop. and mean alignment of the tibial component was 90.4+/-2.2degrees (85.1-94.2degrees) postop. CONCLUSION: This study showed that IIMA could be of considerable value as a new guider of alignment that is easily accessible and highly effective during total knee arthroplasty.

The coronal angulation of the femur in Thai osteoarthritic knee patients with varus deformity.

Objective: To determine the angulation of the distal femoral axis - femoral mechanical axis and the coronal femoral bowing in varus OA knees. This information is necessar, because the routine distal femoral valgus cut can potentially lead to error in post-operative alignment. Methods: Hip to ankle standing radiographs were ordered in 160 varus OA patients (200 limbs). The mean age of the patients was 63.8 years. In addition, 50 limbs of young volunteers with an average age of 28.8 years, were also studied for comparison. The distal femoral axis-femoral mechanical axis angle, femoral bow, and other angles were determined and compared between two groups. Results: Mean distal femoral axis-mechanical axis angle was 7.0˚+ 1.5˚ and mean femoral bow was 2.4˚+ 2.6˚ in patients compared to 5.7˚ + 0.5˚ and 0.3˚+ 0.5˚ respectively, in controls. The varus deformity significantly correlated with femoral bowing. Thirty-five (17.5 percent) of OA limbs showed a distal femoral axis-mechanical axis angle of more than 9˚ and there were 42 OA limbs (21%) that had significant (> 3˚) femoral bowing. Conclusion: These findings have implications in deciding the optimum valgus angle at which to perform distal femoral resection during TKA in varus OA knee.

Femoral Neck Anteversion Measured Using a 3D CT Scan Perpendicular to the Mechanical Axis of the Femur

PURPOSE: We wanted to measure the femoral neck anteversion (FNA) angles using a 3D CT scan that perpendicularly cut the mechanical axis of the femur and to assess the accuracy and reproducibility of different measuring methods. MATERIALS AND METHODS: We obtained 95 cases of 3D CT images of the cross-section perpendicular to the mechanical axis of the femur. The methods used to measure the FNA angles included a method using the CT image of the area where the femoral neck is confluent to the greater trochanter (method 1), a method using the CT image taken from the neck base immediately prior to the beginning of the area of the lesser trochanter (method 2) and a method by which measurements are made after putting 3D bone models on a horizontal plane in virtual space (method 3). The reference axes of the distal femur we used were the anatomical transepicondylar axis, the surgical transepicondylar axis and the real posterior condylar axis. RESULTS: The FNA angles measured by method 1 were 4.79+/-6.41degrees to the anatomical transepicondylar axis (ATEA), 6.09+/-6.58degrees to the surgical transepicondylar axis (STEA) and 7.96+/-6.81degrees to the real posterior condylar axis (rPCA). The FNA angles measured by method 2 were 16.01+/-8.31degrees to the ATEA, 19.52+/-8.38degrees to the STEA and 21.79+/-8.52degrees to the rPCA. The FNA angles measured by method 3 were 20.15+/-12.89degrees to the rPCA. CONCLUSION: The measurement of the FNA angle using a 3D CT scan perpendicular to the mechanical axis is reproducible. The measurement method on the neck base level is more reliable than the one on the proximal neck confluence, and more similar to the measurement method by classic definition.

Accuracy of Inter Femoral Head Center Distance Measurement and Evaluation for Coronal Alignment of Femoral Component during Total Knee Arthroplasty / 대한정형외과학회잡지

PURPOSE: Alignment is an important factor in the long-term success of total knee arthroplasty. In the total knee arthroplasty, the conventional extramedullary femoral alignment system has significant error in femoral coronal alignment, since it is difficult to find the femoral head center and it is time consuming to determine during the operation. The purpose of our study was to evaluate the accuracy of the newly-designed marker system for extramedullary femoral alignment that uses radiologic distance between the 2 femoral head centers. MATERIALS AND METHODS: Between July 2008 and July 2009, 90 patients (100 knees) with knee osteoarthritis underwent total knee arthroplasty using the femoral extramedullary femoral guide system. We measured the distance between the femoral head centers using the radiologic picture archiving and communication system (PACS, General Electric, Milwaukee, WI) system preoperatively, then plastic rods and metal pegs were used to simulate the inter femoral head center distance. By placing the center of the plastic rod after marking the inter femoral head center distance on the central body line, we could trace the coronal mechanical axis. We measured the angle between the femoral mechanical axis and the femoral component in standing long leg antero-posterior radiograph to assess radiologically the accuracy of coronal alignment postoperatively. RESULTS: The average femoral length in the study group was 402.5+/-16.2 mm. The mean distance between the femoral head and the center of the marker was 49.6+/-17.9 mm. The average error in estimation of the distance between the femoral head center and the metal peg of the marker was 3.78+/-3.14 mm. The positional error in alignment was 1degrees or less in 90% and 2degrees or less in 100% of knees. The average angle of femoral component to femoral mechanical axis was 89.9+/-1.5degrees (range 84.4-93.6degrees). The coronal alignment of the femoral components was within 90degrees+/-3degrees in -96% of cases. CONCLUSION: Our results suggest that the clinical method reported here is a simple and reliable method to localize the center of the femoral head during total knee arthroplasty.

An Extramedullary Femoral Alignment System in Total Knee Arthroplasty Using the Inter-Femoral Head Center Distance / 대한정형외과학회잡지

PURPOSE: Total knee arthroplasty using the extramedullary technique for alignment has some difficulty for detecting the center of the femoral head intra-operatively. In this study we tried to evaluate the usefulness and accuracy of a newly developed Mechanical Axis Marker that synchronizes the center of the knee joint and femoral head with the mechanical axis for the distal femoral cutting and femoral prosthesis alignment. MATERIALS AND METHODS: Between October 2008 and January 2009, 255 knees in 156 patients underwent total knee arthroplasty. We measured the distance between each centers of the femoral head using the PACS system and we applied the distance to the newly developed Mechanical Axis Marker. Subsequently, we applied the new marker to patients to align the centers of knee, the femoral head and the marker in line with the mechanical axis intra-operatively. The accuracy of the marker was validated with C-arm fluoroscopy pre-operatively in 20 patients. Post-operatively we measured and analyzed the frontal femoral component angle to evaluate the coronal alignment of the femoral implant. The accuracy was rated as excellent when the alignment was 5degrees. RESULTS: The pre-operative validation study with the C-arm fluoroscopy showed that the distance between the femoral head center and the metal peg of the marker was within 5 mm in 95% of the patients, which implied acceptable accuracy. The average frontal femoral component angle against the mechanical axis was 89.0degrees+/-1.1 (range 86degrees-96.6degrees). The proportion of excellent, good, and poor alignments was 90.6% (231 cases), 8.6% (22 cases), and 0.8% (2 cases), respectively. The intraclass correlation coefficient between the two observers for the frontal femoral component angle was 0.972 which showed high concordance. CONCLUSION: Our results indicate that the extramedullary technique assisted by our new Mechanical Axis Marker can easily identify the center of femoral head and improve the accuracy of frontal femoral component alignment with the proper mechanical axis.

Robotic Total Knee Arthroplasty: Minimal Follow-up of 3 Years

PURPOSE: We wanted to evaluate the clinical and radiographic results of robotic-assisted implantation of TKAs with a minimum follow-up of three years. MATERIALS AND METHODS: 50 TKAs using ROBODOC(R) (Integrated Surgical Systems, Sacramento, CA, USA) were included in this study. We assessed the radiographic measurements with regard to the change of the mechanical axis and the inclination of the femoral and tibial components. The clinical results were evaluated with using the range of motion (ROM), the Hospital for Special Surgery (HSS) scores and the Western Ontario and McMaster University (WOMAC) scores. RESULTS: The angle formed by the mechanical axis of the femur and tibia was corrected from 6.57degrees varus to 0.49degrees valgus. The mean coronal inclination of the femoral and tibial components was 89.52degrees and 90.12degrees, respectively, and the mean sagittal inclination of the femoral and tibial components was 1.06degrees and 85.56degrees, respectively. There were 45 excellent and 5 acceptable results for the femoral component, and 38 excellent and 11 acceptable results for the tibial components. On the clinical assessment, the ROM improved from 124.9degrees to 128.4degrees, and the improvements of the HSS and WOMAC scores were 70.06 to 95.72 and 65.64 to 28.92, respectively. CONCLUSION: A surgical robot system that has the ability to execute highly precise preoperative planning and intraoperative procedure for TKA provides good clinical and radiographic results at three years follow-up.

Analysis of the Mechanical Axis of the Lower Limb in Patients with Isolated Meniscal Tear

PURPOSE: We wanted to evaluate the relationship between meniscal tear and the alignment of the lower limb. MATERIALS AND METHODS: Between Oct 2006 and Jun 2008, 125 patients aged 55 year or less with isolated meniscal tear and who were examined arthroscopically were included in this study. The patients had no severe lesion (ulceration or defect) of cartilage or ligamentous injuries. 21 individuals who had no abnormal findings on MRI were selected as the control group. The patients were divided into the complete discoid lateral meniscus, incomplete discoid lateral meniscus, lateral semilunar meniscus and medial semilunar meniscus groups and they were subdivided according to gender and whether there was an obvious history of trauma. The varus percentage was defined as a percentage of the width from where the mechanical axis passes the level of the tibial articular surface to the middle of the tibial articular surface on the orthoroentgenogram of the lower leg. Each individual's varus percentage was expressed as the mean of the measurements taken by three observers. The comparisons were done using the Wilcox Signed Ranks Test and the Mann-Whitney Test. RESULTS: There was no significant difference between the involved knee and the contralateral normal knee in terms of the varus percentage in all the groups (p>0.05). There were no significant differences in each group according to the history of trauma, a complete discoid lateral meniscus, an incomplete discoid lateral meniscus, a lateral semilunar meniscus and a medial semilunar meniscus. However, there was a significantly greater varus percentage for the medial semilunar meniscus group without a history of trauma. CONCLUSION: There was a statistical relationship between tears on the medial semilunar meniscus without a history of trauma and genu varum. Tears on a complete discoid lateral meniscus, incomplete discoid lateral meniscus and lateral semilunar meniscus had a little relationship with the mechanical axis of the lower leg.

Bony Landmarks for Determining the Mechanical Axis of the Femur in the Sagittal Plane during Total Knee Arthroplasty

BACKGROUND: There is no accepted landmark for the mechanical axis of the femoral axis in sagittal plane in conventional total knee arthroplasty. METHODS: As palpable anatomic landmarks of the femur, lateral epicondyle, and anterior margin of the greater trochanter were identified. The line connecting these two landmarks was defined as the "palpable sagittal axis". The mechanical axis of the femur was compared with the palpable sagittal axis and the distal femoral anterior cortex axis. These axes were also compared with sagittal bowing of the femur. RESULTS: The distal femoral anterior cortex axis and the palpable sagittal axis were flexed by 4.1degrees and 2.4degrees more than the sagittal mechanical axes, respectively (p < 0.05). However, the palpable sagittal axis was not correlated with sagittal bowing of the femur (Spearman's rs, 0.17; p = 0.14). CONCLUSIONS: The palpable sagittal axis showed a consistent relationship with the sagittal mechanical femoral axes regardless of the severity of the sagittal bowing of the femur.

Measurement of verus inclination of the proximal tibia of Chinese and its relevance in TKA / 中国矫形外科杂志

[Objective]To measure the verus inclination of the proximal tibial of young Chinese through radiographs and determine how many degrees should the femoral prothesis be externally rotationed during total knee arthroplasty(TKA).[Method]Standardized anteroposterior radiographs of the entire lower legs of 200 volunteers' were taken. Two angles were measured as followes:Angle PT: angle between tibial articular margins and a line perpendicular to the tibial mechanical axis;Angle FT:angle between the transcondylar tangent anda line perpendicular to the tibial mechanical axis. [Result]Angle PT has a mean value of 4.06? and Angle FT is 5.00?. [Conclusion]When the posterior condylar axis is used during TKA for Chinese, the femoral prothesis should be externally rotationed 5.00? to get the optimum rotational orientation.