Stress increase inside the Anterior Patella due to Implantation of the Patellar Component : A Finite Element Analysis

Yeon Soo Lee,Joyce H. Keyak,Thay Q. Lee 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.5

This study aimed to assess the stress change inside the patella after implantation of an polyethylene patella button. Finite elements models of the patellae before and after implantation of patellar button were created. Experimentally determined spring constants of muscles and ligaments, and patellofemoral contacting loads were applied to the models at 30°, 60°, and 90° of knee flexion. The Von Mises stress of the intact patella decreased with increased knee flexion, while that of implanted patella increased. Also, the stress scale in the implanted patella was 3~9 times higher than in the intact one. The highly stressed region of the intact patella moved proximally with higher knee flexion angles, while that of the implanted model stayed near the central anterior patella. At 90° of knee flexion, the stress in the anterodistal patella increased considerably after implantation of a patella button so that the anterodistal patella may be susceptible to be painful source.

무릎인대 길이 대 무릎골 길이의 비율 : 굴곡 및 신전 자기공명영상비교

서재승 대한영상의학회 1998 대한영상의학회지 Vol.38 No.5

Purpose : To determin whether radiographic assessment of patella position abnormalities (such as patella altaor baja) using the 'patellar tendon : patella ratio' (Insall & Salvati's method) can be applied to flexion andextension sagittal MR images of the knee Materials and Methods : Both flexion (55-90。, mean 62。) and extensionT2-weighted sagittal images of 58 knees (54 patients;age:19-72 years:M:F=40:18 were obtained and reviewed by meansof routine lateral radiographs (flexion of knees:30-60。). Patellar tendon and diagonal length were measured onroutine radiographs and on flexion and extension MR images;length was measured by sagittal T2-weighted MR imagingfrom the inner aspect of patellar insertion to the inner asspect of tibial insertion, an approach whichdemonstrated the even thickness of the patellar tendon and the greastest diameter of the patella. Usingcorrelation analysis, the ratio of patellar tendon to diagonal length was compared between examination methods andbetween the non-wavy and wavy forms of patellar tendon. Results : The mean length of the respectirely, 'patella,patellar tendon and patellar tendon to patella ratio' were 4.15$\pm$0.38, 4.04$\pm$0.49 and 0.9$\pm$0.12, respectively, onroutine radiographs; 4.32$\pm$0.36, 3.8$\pm$0.47 and 0.89$\pm$ 0.12, respectively, on flexion MR images;and 4.3$\pm$0.36,3.93$\pm$0.44 and 0.92$\pm$0.12, respectively on extension MR images. Between these three different modes of assessment,a high degree of correlation of mean patella length (r=0.89-0.92) and of mean patellar tendon length (r=0.71=0.85)were found. In addition, correlation of 'patella to patellar tendon ratios' was excellent : radiographs andflexion MRimages(r=0.76);radiographs and extension MR images(r=0.76);flexion and extension MR images(r=0.84).According to the form of patellar tendon, radiographs correlated better with extension MR images (r-0.71) thanwith flexion images (r=0.62) in the non-wavy form of patellar tendon, whereas in the wavy form, correlation withflexion images (r=0.83) was better than with extension images(r=0.78). Conclusion : MR asessment of 'patellartendon to patella ratio's correlated well with radiographic assessment, and the latter can therefore be used forthe evaluation of abnormal patellar position. Radiographs correlated better with extension MR images in thenon-wavy form of patellar tendon, whereas in the wavy form, correlation with flexion images was better.

슬개골을 치환하지 않은 슬관절 전치환술 후 슬개골 관절면의 변성 범위에 따른 기능적 결과

경희수(Hee-Soo Kyung),차기봉(Ki-Bong Cha),오창욱(Chang-Wug Oh),손영헌(Young-Hon Son),백승길(Seung-Kil Baik) 대한정형외과학회 2008 대한정형외과학회지 Vol.43 No.1

목적: 슬개골을 치환하지 않은 슬관절 치환술 후 슬개 관절면의 변성 범위에 따른 기능적 결과를 분석하였다. 대상 및 방법: 2002년부터 2003년까지 슬개골을 치환하지 않고 슬관절 치환술을 받은 임의로 선택한 퇴행성 관절염환자 52명의 환자 63례를 대상으로 하였다. 평균 나이는 67.2세였고, 여자가 49명, 남자가 3명이었으며, 평균 추시 기간은 2년 8개월이었다. 수술에 사용한 인공 삽입물은 모두 PFC-sigma 기구였다. 임상적 결과는 Feller의 슬개골 지수, 전방 슬관절통 및 탄발음 빈도를 슬개골 관절면의 침범 범위, 슬개-대퇴정렬에 따라 분석 하였다. 결과: Feller의 슬개골 지수는 술 전 평균 20.1에서 술 후 26.9로 호전되었으며(p<0.05), 슬개 관절면의 침범정도에 따른 의미 있는 차이는 없었고(p>0.05), 슬개골 부정 정렬시 그 값이 작았다(p<0.05). 술 후 전방 슬관절 통증은 6개월까지 슬개 관절면 침범 정도에 따라 증가하였으나 그 이후부터는 관절면의 침범이 75% 이상인 경우를 제외하고 차이가 없었고 시간이 지남에 따라 점점 감소하여 사라졌다. 탄발음의 빈도는 1년까지 슬개 관절면 침범 정도에 따라 증가하였으나 그 이후부터는 시간이 지남에 따라 감소되었다. 결론: 슬개골을 치환하지 않은 슬관절 전치환술의 임상적 결과는 슬개 관절연골의 변성 범위와는 영향이 없었고 대퇴 슬개관절의 정렬 상태에 따라 차이를 보였으며, 관절면의 변성 범위가 넓을수록 수술후 조기에 전방 슬관절 통증 및 탄발음의 정도가 심하였으나 시간이 지날수록 차이는 없었다. Purpose: We evaluated the functional outcome as degeneration of articular surface of the patella after total knee arthroplasty without resurfacing the patella. Materials and Methods: From 2002 to 2003, 63 cases of 52 osteoarthritis patients who underwent total knee arthroplasty without resurfacing the patella as randomized selection were evaluated. Average age was 67.2 years old. Female were 49 patients, and male 3 patients Average follow-up periods were 32 months. Used implant were all PFC-sigma. Clinical outcomes was analyzed as Feller's patella score (perfect score; 30 points), anterior knee pain, crepitation according to the extent of involvement of articular surface of the patella and patello-femoral tracking. Results: The Feller's patella score increased from mean 20.1 to 26.9 (p<0.05). However, there were no statistically significant differences as extent of involvement of patello-femoral joint (p>0.05). The patella score was low with patellar mal alignment. Anterior knee pain after operation increased during postoperative 6 months according to the extent of degeneration of patellofemoral joint, but after 6 months there is no statistically significant differences except group 4 and all groups gradually decreased. Crepitation was increased during postoperative 1 year according to the extent of cartilage degeneration and after that its incidence decreased with time. Conclusion: The clinical results of total knee arthroplasty without resurfacing the patella was not influenced by the extent of degeneration of patello-femoral joint, but by alignment of patellofemoral joint. Anterior knee pain and crepitation increased in proportion to the extent of degeneration of patello-femoral joint in early period, but it fade out with time.

Serial Radiographs Showing Progression of a Patellar Stress Fracture and Beneficial Surgical Technique for a Displaced Patellar Stress Fracture

Kazuha Kizaki,Fumiharu Yamashita,Noboru Funakoshi 대한슬관절학회 2018 대한슬관절학회지 Vol.30 No.1

Stress fractures of the patella occurring in athletes are quite rare and only 23 cases have been introduced in English literatures. Stress fractures of the patella are classified into two types: transverse and longitudinal. They are mostly seen in the distal one-third of the patella on a plain lateral radiograph. We present here a 16-year-old female basketball player with a stress fracture of the patella. Her serial radiographs demonstrated progression of the fracture including a lytic cortex lesion, known as the gray cortex sign for early stage stress fractures, in the distal one-third of the patella on plain lateral radiographs. In addition, we introduce a surgical technique using non-absorbable suture ligatures (No.2 Ethibond) for a displaced transverse stress fracture of the patella when the extensor mechanism is intact. The ligatures are passed through into the patella using suture passers and simply tied down over the top of the patella. In our case, it led to neither hardware-related nor circumferential loop-related irritation postoperatively.

Separate Vertical Wiring for the Fixation of Comminuted Fractures of the Inferior Pole of the Patella

송형근,양규현,유제현,변영수 연세대학교의과대학 2014 Yonsei medical journal Vol.55 No.3

Purpose: Among patients over 50 years of age, separate vertical wiring alone may be insufficient for fixation of fractures of the inferior pole of the patella. Therefore, mechanical and clinical studies were performed in patients over the age of 50 to test the strength of augmentation of separate vertical wiring with cerclage wire (i.e., combined technique). Materials and Methods: Multiple osteotomies were performedto create four-part fractures in the inferior poles of eight pairs of cadaveric patellae. One patella from each pair was fixed with the separate wiring technique, while the other patella was fixed with a combined technique. The ultimate load to failure and stiffness of the fixation were subsequently measured. In a clinical study of 21 patients (average age of 64 years), comminuted fractures of the inferior pole of the patellae were treated using the combined technique. Operative parameters were recorded from which post-operative outcomes were evaluated. Results: For cadaveric patellae, whose mean age was 69 years, the mean ultimate loads to failure for the separate vertical wiring technique and the combined technique were 216.4±72.4 N and 324.9±50.6 N, respectively (p=0.012). The mean stiffness for the separate vertical wiring technique and the combined technique was 241.1±68.5 N/mm and 340.8±45.3 N/mm, respectively (p=0.012). In the clinical study, the mean clinical score at final follow-up was 28.1 points. Conclusion: Augmentation of separatevertical wiring with cerclage wire provides enough strength for protected early exercise of the knee joint and uneventful healing.

청소년기에서 발생한 슬개골 상단부 소매형 골절

유문집 ( Moon Jib Yoo ),유재성 ( Jae Sung Yoo ),류지원 ( Jee Won Ryu ) 대한외상학회 2013 大韓外傷學會誌 Vol.26 No.3

A patella sleeve fracture is a type of avulsion fracture in which a small osseous fragment gets, along with a sleeve of periosteum and cartilage, is pulled off from the patella. The avulsed sleeve of cartilage and periosteum is not apparent on plain radiographs, which can result in a missed diagnosis or an underestimate of the extent of injury. An avulsion or sleeve fracture of the patella in a child can occur at the superior or the inferior pole of the patella. However, most reported cases of sleeve fractures involve the inferior patellar pole, with fractures involving the superior patellar pole being very rare. The authors report a case of a sleeve fracture of the superior pole of the patella in an adolescent; the fracture was diagnosed with magnetic resonance imaging (MRI) and was treated with surgery after early diagnosis. The course was uneventful, and the outcome was excellent.

In vivo magnetic resonance imaging morphometry of the patella bone in South Indian population

Reshma Muhamed,Vasudha V. Saralaya,B. V. Murlimanju,Ganesh Kumar Chettiar 대한해부학회 2017 Anatomy & Cell Biology Vol.50 No.2

Racial differences exist in the dimensions of structures and the commercially available prostheses are designed based on the Caucasians. In this context, the goal of the present investigation was to determine the gender wise measurements of patella bone in South Indians. The present study included axial magnetic resonance images of the knee joint from 140 South Indian adults (70 males, 70 females; aged between 20–70 years). The angle, width, thickness, lateral facet width, facet thickness, ratio of the lateral facet, the relative thickness and ratio of facet thickness were measured in the patella by using the digital ruler. The statistical analysis was performed by using the SPSS software. The dimensions exhibited statistically highly significant sexual dimorphism (P≤0.001). The mean value was higher in males than females except for the ratio of patellar lateral facet and patellar facet thickness ratio. It was observed that the males exhibit more variability than females in all the measurements of patella except patellar thickness, patellar facet thickness, patellar relative thickness, and patellar facet thickness ratio. The present study of the in vivo morphometry of patella bone from the South Indians can provide a population and gender specific database for the morphometric measurements of the patella. We believe that the data of the present study will be useful to the orthopaedician during the procedures like arthroplasty of the total knee, patellofemoral arthroplasty, resurfacing of patella, and designing the prosthetic implant.

외상에 의한 일과성 슬개골 외측탈구의 자기공명영상소견

설혜영,김성문,안중모,신명진,Seol, Hye-Yeong,Kim, Seong-Mun,An, Jung-Mo,Sin, Myeong-Jin 대한영상의학회 2001 대한영상의학회지 Vol.45 No.4

목적:임상적으로 외상 후 일과성 슬개골 외측 탈구가 의심되는 대부분의 경우에 방사선과 영역의 검사로는 단순촬영만으로 이루어지며 자기공명영상을 시행하는 경우는 매우 드물다.이에 저자들은 자기공명영상 소견을 분석하고 그 특징을 알아보고자 하였다. 대상과 방법:외상 후 일과성 슬개골 외측 탈구 기왕력이 있고 슬관절 자기공명영상을 시행한 환자 중 비정상 소견을 보인 8명의 환자를 대상으로 하였다.6명의 남자와 2명의 여자 환자로서 평균 연령은 22세이었다.이들 중 5명은 보존적 치료를 받았으며 3명은 관절경을 이용한 수술적 치료를 받았다.두 명의 방사선과 의사가 골 좌상과 연골 결손의 위치,골절 혹은 유리체의 유무,삼출액 종류,동반된 연부 조직의 손상과 슬개골의 아탈구 등을 후향적으로 분석하였다. 결과:골 좌상은 외측 대퇴과 (n=8,100%),슬개골의 내측 관절면 (n=8,100%)과 외측 경골 고평부 (n=3,38%)에 있었다.연골 결손은 슬개골의 내측 관절면 (n=5,63%)에만 있었다.골절은 외측 대퇴과 (n=2,25%)와 슬개골의 내측 관절면 (n=1,13%)에 있었다.유리체는 3예 (38%)에서 있었고 삼출액은 7예 (88%)에서 있었는데,그 중 3예는 지방혈관절증(lipohe-marthrosis)이었다.연부 조직의 손상으로는,내측 슬개골 지대 (medial patellar retinaculum)의 열상 (n=8,100%),전방십자인대 열상 (n=1,13%)과 슬개 인대의 손상 (n=2,25%)등 이 동반되었다.슬개골의 아탈구는 7예 (88%)에서 있었다. 결론:외상 후 일과성 슬개골 외측 탈구의 경우에 자기공명영상을 이용하여 골과 연골,연부 조직의 손상을 잘 알 수 있었다.성병변이 원인질환임을 알 수 있었다.따라서 위점막표면결절화의 방사선학적 소견에 익숙해지는 것이 정확한 진단뿐 아니라 결절화의 범위를 결정하고 추가검사를 권유하는 등의 진단적 가치를 높일수 있다.회화 및 낭성변화는 갑상선암의 림프절 전이를 예측하는데 매우 유용한 지표로 생각된다.(離乳食)이 전무(全無)한 실정(實情)이고 임신부(妊娠婦)나 수유부(授乳婦)를 위(爲)한 보충식(補充食)도 따로 없다.서는 NE는 심박증가(心搏增加)와 혈압상승(血壓上昇)을 일으켰으며, clonidine은 심박(心搏)에는 거의 변동(變動)을 일으키지 않았고 경미(輕微)한 혈압상승(血壓上昇)을 일으켰다. 8) NE 및 clonidine에 의한 심박감소(心搏減少), clonidine에 의한 혈압하강(血壓下降)은 주(主)로 presynaptic ${\alpha}$-adrenoceptor를 중개(仲介)하여 일어나나, NE 및 clonidine에 의한 혈압상승(血壓上昇)은 presynaptic site 이외(以外)의 부위(部位)를 중개(仲介)하여 일어나는것 같다.뇌동맥 직경은 성별에 상관없이 고령층이 저령층에 비하여 의미있게 크거나 큰 경향을 나타내었다. 고령층의 중뇌동맥 근위부 직경은 남자가 2.59$\pm$0.35 mm, 여자가 2.38$\pm$0.37 mm이었고, 원위부 직경은 남자가 2.63$\pm$0.43 mm, 여자가 2.39$\pm$0.35 mm 이었다.고 Monaliza Finely Soft는 23% 더 높은 분리율을 나타냈으므로 선충분리용(線蟲分離用)으로는 향수처리(香水處理)되지 않은 것이 더 좋은 것으로 사료(思料) Purpose: To determine the magnetic resonance (MR) imaging characteristics of traumatic transient lateral dislocation of the patellae. Materials and Methods: In eight patients (6 males, 2 females, mean age: 22.4 years) in whom transient lateral dislocation of the patella was diagnosed, the distinctive MR imaging findings reflecting known injury mechanism were retrospectively analyzed with regard to bone contusion, chondral defect, fracture, loose body, joint effusion, and the associated soft tissue abnormalities. Results: All of eight patients had bone contusions in the lateral femoral condyle and medial facet of the patella, while in five, chondral defects were present in this latter region. In three patients, fractures of the on lateral femoral condyle(n=2) and medial facet of the patella (n=3) were noted, and in three others, loose bodies were noted. Joint effusion [simple effusion (n=4), lipohemarthrosis (n=3)] was observed in seven patients, and associated soft tissue injuries [to the medial patellar retinaculum (n=8), patellar tendon (n=2), and anterior cruciate ligament (n=1)] in eight. Patellar subluxation was found in seven. Conclusion: MR imaging is a useful technique for the diagnosis of traumatic lateral dislocation of the patella. The significant MR findings are bone contusion in the lateral femoral condyle and medial facet of the patella, chondral defect, fracture, joint effusion, injury to the medial patellar retinaculum, and patellar subluxation.

Separate Vertical Wirings for the Extra-articular Fractures of the Distal Pole of the Patella

( Young Mo Kim ),( Jun Young Yang ),( Kyung Cheon Kim ),( Chan Kang ),( Yong Bum Joo ),( Woo Yong Lee ),( Jung Mo Hwang ) 대한슬관절학회 2011 대한슬관절학회지 Vol.23 No.4

Purpose: To evaluate the usefulness of separate vertical wirings for extra-articular fracture of distal pole of patella. Materials and Methods: We have analyzed the clinical results of 18 cases that underwent separate vertical wirings for extra-articular fracture of distal pole of the patella from March 2005 to March 2010, by using the range of motion and Bostman score. Occurrence of complication was also evaluated. Additionally, by taking simple radiographs, the correlation between the postoperative degree of anterior transposition of bone fragment and the time of bone fusion, preoperative length of bone fragment, and occurrence of comminuted fracture were investigated. Results: It took an average of 13.8 weeks for radiological bone union after separate vertical wiring fixation. Flexion contracture was an average of 0.8 degrees and further flexion was an average of 127.6o, and Bostman score was an average of 27.5 points (excellent in 12 cases, and good in 6 cases). On the fi rst postoperative year, average flexion contracture was 0.6 degrees and further flexion was an average of 136.3o, which exhibited increased joint motion and recovery to normal range of motion, and Bostman score was an average of 28.7 points (excellent in 16 cases, and good in 2 cases). There was no statistically signifi cant difference between the preoperative bone fragment length and presence of comminution, and degree of anterior transposition of bone fragment after fracture union on simple radiograph (p=0.175, p=0.146). Conclusions: We were able to obtain satisfactory clinical results, while preserving the bone fragment by separate vertical wiring fixation for extraarticular fracture of distal pole of patella. Moreover, the method is easy to perform, which is also considered as a useful surgical method for extraarticular fracture of distal pole of patella.

Patella Resurfacing during Total Knee Arthroplasty: Have We Got the Issue Covered?

Nemandra A. Sandiford,Uthman Alao,Wazirl Salamut,Stefan Weitzel,J. A. Skinner 대한정형외과학회 2014 Clinics in Orthopedic Surgery Vol.6 No.4

Background: Management of the patella during total knee arthroplasty (TKA) is controversial. Multiple studies have examined mechanical and clinical results of TKA with native and resurfaced patellae with no clear consensus. Methods: We surveyed a large cohort of consultant surgeons in a questionnaire based study in order to assess the indications for patella resurfacing and to correlate practice with degree of specialization, experience and volume of procedures performed. Results: Six hundred and nineteen surgeons were included. The main indication for patella resurfacing was patellofemoral arthritis. The ratio of those who always:sometimes:never resurfaced was 1:2:1 irrespective of experience or volume performed. There was no difference between knee specialists and non-specialists (p = 0.977) or between high and lower volume surgeons (p = 0.826). Senior and high volume surgeons tended to always resurface. Conclusions: The majority of surgeons only sometimes resurfaced the patella. The number who always and never resurfaced were similar. There was a tendency for more experienced and high volume surgeons to always resurface.