The Variation of the Patellar Height in Total Knee Arthroplasties and its Relationship with the Replacement or not of the Patella / Variação da altura patelar nas artroplastias totais do joelho e sua relação com a substituição ou não da patela

Abstract Objective To compare the measurement of patellar height in the pre- and postoperative period of total knee arthroplasties (TKAs) and its variation in patients with and without patellar replacement. Methods Retrospective evaluation of radiographs of patients submitted to TKA between 2014 and 2020. Profile radiographs were evaluated using the modified Caton-Deschamps patellar height index, comparing the pre- and postoperative measurements of 90 patients, with a total of 100 knees. Next, two groups were compared with a different surgical technique, considering the replacement or not of the patella. All patients who had x-rays evaluated had indication of TKA by osteoarthrosis without previous procedures that could interfere at patellar height. Results The statistical analysis showed a statistically significant difference, with the preoperative index superior to the postoperative rate, evidencing an overall decrease in patellar height. The Caton-Deschamps index modified for mean preoperative TKA was 1.41 (±0.25), and it was 1.31 (± 0.25), p< 0.001for postoperative TKA. No significant difference was found in the variation of this index when comparing the groups with and without patellar replacement. The mean difference of the index in the group without patella was 0.11, and 0.08 in the group with patella, and this difference was considered nonsignificant, p= 0.510. Conclusion We can conclude that patellar height had significant variation in the total group, with reduction of patellar height in the postoperative period. However, the height did not vary significantly between the postoperative groups with and without patellar replacement, regardless of the choice of the surgeon.

Resumo Objetivo Comparar a medida da altura patelar no pré- e pós-operatório das artroplastias totais do joelho (ATJs) e sua variação nos pacientes com e sem substituição patelar. Métodos Avaliação retrospectiva de radiografias de pacientes submetidos a ATJ entre 2014 e 2020. Foi feita a avaliação de radiografias em perfil, usando o índice de altura patelar de Caton-Deschamps modificado, comparando as medidas do pré- e pós-operatório de 90 pacientes, totalizando 100 joelhos. A seguir, foi feita a comparação de dois grupos, com técnica cirúrgica distinta, considerando a substituição ou não da patela. Todos os pacientes que tiveram radiografias avaliadas tiveram indicação de ATJ por osteoartrose sem procedimentos prévios que pudessem interferir na altura patelar. Resultados A análise estatística demonstrou uma diferença estatisticamente significativa, sendo o índice pré-operatório superior ao pós-operatório; evidenciando um abaixamento global da altura patelar. O índice Caton-Deschamps modificado para ATJ pré-operatório médio foi de 1,41 (±0,25), e o pós foi de 1,31 (±0,25), p< 0,001. Não foi encontrada diferença significativa na variação deste índice quando comparados os grupos com e sem substituição patelar. A diferença média do índice no grupo sem patela foi de 0,11 e no grupo com patela foi de 0,08, sendo esta diferença considerada não significativa, p= 0,510. Conclusão Podemos concluir que a altura patelar teve variação significativa no grupo total, com redução da altura patelar no pós-operatório. Entretanto, a altura não variou de forma significativa entre os grupos pós-operatórios com e sem substituição patelar, independentemente da opção do cirurgião.

Long-term results of synovectomy in total knee arthroplasty: a prospective, randomized controlled trial / 中华医学杂志(英文版)

BACKGROUND@#Synovectomy has been introduced into total knee arthroplasty (TKA) with the aim of relieving pain and inflammation of the synovium. However, there are no long-term, comparative data to evaluate the effect of synovectomy in TKA. This study was aimed at assessing pain, function, and complications in patients undergoing synovectomy during TKA for osteoarthritis (OA) at long-term follow-up.@*METHODS@#This was a prospective randomized controlled trial of 42 consecutive patients who underwent staged bilateral TKA. Patients undergoing the first-side TKA were allocated to receive TKA with or without synovectomy followed by a 3-month washout period and crossover to the other strategy for the opposite-side TKA. The overall efficacy of both strategies was evaluated by determination of blood loss, the Knee Society score (KSS), and knee inflammation conditions during a 3-month postoperative period. The postoperative pain, range of motion (ROM), and complications were sequentially evaluated to compare the two groups until 10 years after surgery.@*RESULTS@#At the 10-year follow-up, both groups had a similarly significantly improved ROM (114.88 ± 9.84° vs. 114.02 ± 9.43°, t  = 0.221, P  = 0.815) and pain relief with no differences between the two groups (1.0 [1.0] vs. 1.0 [1.5], U  = 789.500, P  = 0.613). Similar changes in total blood loss, KSS, and knee inflammation were found in both groups during 3 months postoperatively ( P  > 0.05). Additionally, there was no significant difference regarding complications and satisfaction between the two groups ( P  > 0.05).@*CONCLUSIONS@#Synovectomy in conjunction with TKA for primary OA does not seem to provide any benefit regarding postoperative pain, ROM, and satisfaction during a 10-year follow-up. In addition, it may not result in more blood loss and increased incidence of long-term complications. Based on our long-term findings, it should not be performed routinely.@*TRIAL REGISTRATION@#Chinese Clinical Trial Registry, ChiCTR-INR-16008245; https://www.chictr.org.cn/showproj.aspx?proj=13334 .

Influence of patellofemoral joint degeneration on clinical outcomes after medial unicompartmental knee arthroplasty / 中华医学杂志(英文版)

BACKGROUND@#Patellofemoral joint (PFJ) degeneration has traditionally been regarded as a contraindication to unicompartmental knee arthroplasty (UKA). More recently, some researchers have proposed that PFJ degeneration can be ignored in medial UKA, and others have proposed that this change should be reviewed in PFJ degenerative facets and severity. This study aimed to systematically evaluate the effect of PFJ degeneration on patient-reported outcome measures (PROMs) and revision rates after medial UKA.@*METHODS@#Electronic databases (PubMed, Embase, Web of Science, etc.) were searched for studies assessing the influence of PFJ degeneration on medial UKA. A random-effects meta-analysis was conducted for the Oxford knee score (OKS), Knee society score (KSS), and revision rates and stratified by PFJ degenerative facets (medial/lateral/trochlear/unspecified), severe PFJ degeneration (bone exposed), and bearing type (mobile/fixed). Heterogeneity was assessed by the Cochran Q test statistic and chi-squared tests with the I-squared statistic.@*RESULTS@#A total of 34 articles with 7007 knees (2267 with PFJ degeneration) were included (5762 mobile-bearing and 1145 fixed-bearing and 100 unspecified). Slight to moderate degenerative changes in the medial and trochlear facets did not decrease the OKS and KSS, and only lateral facets significantly decreased the OKS (mean difference [MD] = -2.18, P   <  0.01) and KSS (MD = -2.61, P   <  0.01). The severity degree of PFJ degeneration had no additional adverse effect on the OKS, KSS, or revision rates. For mobile-bearing UKA, only lateral PFJ degeneration significantly decreased the OKS (MD = -2.21, P  < 0.01) and KSS (MD = -2.44, P  < 0.01). For fixed-bearing UKA, no correlation was found between PROMs/revision rates and PFJ degeneration.@*CONCLUSION@#For medial mobile-bearing UKA, slight to moderate degenerative changes in the PFJ, except lateral facet, did not compromise PROMs or revision rates. For medial fixed-bearing UKA, although it might not be conclusive enough, PROMs or revision rates were not adversely affected by PFJ degeneration (regardless of the facet).

Long-term clinical outcomes following total knee arthroplasty in patients with hemophilic arthropathy: a single-surgeon cohort after a 10- to 17-year follow-up / 中华医学杂志(英文版)

BACKGROUND@#Total knee arthroplasty (TKA) can reduce severe joint pain and improve functional disability in hemophilia. However, the long-term outcomes have rarely been reported in China. Therefore, this study aimed to evaluate the long-term outcomes and complications of TKA in Chinese patients with hemophilic arthropathy.@*METHODS@#We retrospectively reviewed patients with hemophilia who underwent TKA between 2003 and 2020, with at least 10 years of follow-up. The clinical results, patellar scores, patients' overall satisfaction ratings, and radiological findings were evaluated. Revision surgery for implants during the follow-up period was recorded.@*RESULTS@#Twenty-six patients with 36 TKAs were successfully followed up for an average of 12.4 years. Their Hospital for Special Surgery Knee Score improved from an average of 45.8 to 85.9. The average flexion contracture statistically significantly decreased from 18.1° to 4.2°. The range of motion (ROM) improved from 60.6° to 84.8°. All the patients accepted patelloplasty, and the patients' patellar score improved from 7.8 preoperatively to 24.9 at the last follow-up. There was no statistically significant difference in clinical outcomes between the unilateral and bilateral procedures, except for a better ROM at follow-up in the unilateral group. Mild and enduring anterior knee pain was reported in seven knees (19%). The annual bleeding event was 2.7 times/year at the last follow-up. A total of 25 patients with 35 TKAs were satisfied with the procedure (97%). Revision surgery was performed in seven knees, with 10- and 15-year prosthesis survival rates of 85.8% and 75.7%, respectively.@*CONCLUSIONS@#TKA is an effective procedure for patients with end-stage hemophilic arthropathy, which relieves pain, improves knee functions, decreases flexion contracture, and provides a high rate of satisfaction after more than ten years of follow-up.

Musculoskeletal multibody dynamics investigation for the different medial-lateral installation position of the femoral component in unicompartmental knee arthroplasty / 生物医学工程学杂志

The surgical installation accuracy of the components in unicompartmental knee arthroplasty (UKA) is an important factor affecting the joint function and the implant life. Taking the ratio of the medial-lateral position of the femoral component relative to the tibial insert (a/A) as a parameter, and considering nine installation conditions of the femoral component, this study established the musculoskeletal multibody dynamics models of UKA to simulate the patients' walking gait, and investigated the influences of the medial-lateral installation positions of the femoral component in UKA on the contact force, joint motion and ligament force of the knee joint. The results showed that, with the increase of a/A ratio, the medial contact force of the UKA implant was decreased and the lateral contact force of the cartilage was increased; the varus rotation, external rotation and posterior translation of the knee joint were increased; and the anterior cruciate ligament force, posterior cruciate ligament force and medial collateral ligament force were decreased. The medial-lateral installation positions of the femoral component in UKA had little effect on knee flexion-extension movement and lateral collateral ligament force. When the a/A ratio was less than or equalled to 0.375, the femoral component collided with the tibia. In order to prevent the overload on the medial implant and lateral cartilage, the excessive ligament force, and the collision between the femoral component and the tibia, it is suggested that the a/A ratio should be controlled within the range of 0.427-0.688 when the femoral component is installed in UKA. This study provides a reference for the accurate installation of the femoral component in UKA.

A comparative study of short-term effectiveness of "SkyWalker" robot-assisted versus traditional total knee arthroplasty / 中国修复重建外科杂志

OBJECTIVE@#To compare the short-term effectiveness of "SkyWalker" robot-assisted total knee arthroplasty (TKA) and traditional TKA.@*METHODS@#A clinical data of 54 patients (54 knees) with TKA who met the selection criteria between January 2022 and March 2022 was retrospectively analyzed. Among them, 27 cases underwent traditional TKA (traditional operation group) and 27 cases underwent "SkyWalker" robot-assisted TKA (robot-assisted operation group). There was no significant difference between the two groups ( P>0.05) in terms of gender, age, body mass index, osteoarthritis side, disease duration, and preoperative Knee Society Score (KSS), Western Ontario and McMaster University Osteoarthritis Index (WOMAC), visual analogue scale (VAS) score, hip-knee-ankle angle (HKA), lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), and posterior proximal tibial angle (PPTA). The operative time, intraoperative bleeding volume, surgery-related complications, the KSS, WOMAC, and VAS scores before operation and at 6 months after operation, and Forgotten Joint Score (FJS) at 6 months after operation were recorded. X-ray films were taken to review the prosthesis position and measure HKA, LDFA, MPTA, and PPTA. The differences of the clinical and imaging indicators between before and after operation were calculated and statistically analyzed.@*RESULTS@#The operations were completed successfully in both groups. There was no significant difference in the operative time and intraoperative bleeding volume between the two groups ( P>0.05). After operation, 1 case of incision nonunion and 1 case of heart failure occurred in the traditional operation group, while no surgery-related complications occurred in the robotic-assisted operation group. The incidences of surgical complications were 7.4% (2/27) in the traditional operation group and 0 (0/27) in the robotic-assisted operation group, with no significant difference ( P=0.491). Patients in both groups were followed up 6 months. KSS score, WOMAC score, VAS score, and ROM significantly improved in both groups at 6 months after operation when compared with preoperative ones ( P<0.05). There was no significant difference between the two groups ( P>0.05) in the differences between the pre- and post-operative values of the clinical indicators and FJS scores at 6 months after operation. X-ray films showed that the lower extremity force lines of the patients improved and the knee prostheses were in good position. Except for LDFA in the robot-assisted operation group, HKA, LDFA, MPTA, and PPTA significantly improved in both groups at 6 months after operation when compared with the preoperative ones ( P<0.05). There was no significant difference between the two groups in the differences between the pre- and post-operative values of the radiological indicators ( P>0.05).@*CONCLUSION@#The "SkyWalker" robot-assisted TKA is one of the effective methods for the treatment of knee osteoarthritis and had good short-term effectiveness. But the long-term effectiveness needs to be further studied.

Short- and mid-term effectiveness of unicompartmental knee arthroplasty for post-traumatic arthritis of knee / 中国修复重建外科杂志

OBJECTIVE@#To investigate the short- and mid-term effectiveness of unicompartmental knee arthroplasty (UKA) for post-traumatic arthritis (PTA) of knee.@*METHODS@#The clinical data of 30 patients with PTA of unilateral knee between March 2014 and September 2021 was retrospectively analyzed. There were 14 males and 16 females with an average of 64.5 years (range, 33-81 years). The average body mass index was 26.7 kg/m 2 (range, 19.8-35.6 kg/m 2). The types of injuries that caused PTA included intra-articular fracture in 16 cases, extra-articular fracture in 8 cases, and soft tissue injury in 6 cases. The initial injuries were treated by conservative therapy in 12 cases and by surgical therapy in 18 cases. Ten cases were medial compartment osteoarthritis and 20 cases were lateral compartment osteoarthritis. According to Kellgren-Lawrence staging, there were 19 cases of grade Ⅲ and 11 cases of grade Ⅳ. The operative time, the length of hospital stay, complications, and subjective satisfaction were recorded. The Oxford Knee Function Score (OKS), Hospital for Special Surgery (HSS) score, and knee range of motion (ROM) were used to evaluate knee function. Weight-bearing X-ray films were taken to measure the femoro-tibial angle (FTA) and to assess alignment correction of the lower limb.@*RESULTS@#The operative time ranged from 50 to 95 minutes (mean, 63.7 minutes), the length of hospital stay ranged from 3 to 8 days (mean, 6.9 days). Superficial infection occurred in 2 patients, while the remaining incisions healed by first intention. There was no deep vein thrombosis or neurovascular injury. All patients were followed up 17-109 months (median, 70 months). At last follow-up, OKS score, HSS score, and ROM in 30 cases significantly improved when compared with those before operation (P<0.05). Lower limb alignment was significantly corrected and there was significant difference in FTA of the varus and valgus knees between pre- and post-operation ( P<0.05). The patient satisfaction rate was 86.7% (26/30). Two cases developed contralateral osteoarthritis progression during follow-up. No bearing dislocation, prosthesis loosening or sinking occurred and none required further revision.@*CONCLUSION@#For patients with PTA of knee, UKA can obtain definite short- and mid-term effectiveness with high patient satisfaction.

Comparison of outcomes of mixed unicompartmental knee arthroplasty and total knee arthroplasty in the treatment of medial osteoarthritis of the knee / 中国骨伤

OBJECTIVE@#To evaluate outcomes of mixed unicompartmental knee arthroplasty(UKA) and total knee arthroplasty(TKA) in the treatment of medial osteoarthritis(OA) of the knee.@*METHODS@#Retrospective analysis of 156 patients, 44 males and 112 females, aged from 50 to 75 years old with an average of(58.76±4.97) years old, who underwent knee arthroplasty from October 2017 to October 2019. The patients were divided into two groups:81 cases(81 knees) underwent TKA, including 23 males and 58 females, aged from 51 to 75 years old with an average of (58.60±5.01) years old, and 75 case (75 knees) underwent UKA with mixed phase 3 Oxford, including 21 males and 54 females, aged from 50 to 72 years old with an average of (58.92±4.95) years old. The two groups were compared regarding to the clinical outcomes, assessed using surgical information and complications, American Knee Society score(AKSS) clinical score and functional score. Radiographs were assessed using hip-knee-ankle angle(HKA), tibial component valgus/varus angle(TCVA), tibial component posterior slope angle(TCPSA), femoral component valgus/varus angle(FCVA), femoral component posterior slope angle(FCPSA), looking for bearing dislocation, prosthesis loosening, progression of OA in lateral compartment.@*RESULTS@#Intraoperative bleeding, operative time and hospital days were significantly better in the UKA group than in the TKA group (P<0.05), and there were no postoperative complications in either group. Patients in both groups were enrolled with an average follow-up time of (38.01±8.90) months, ranged from 24 to 54 months. AKSS functional, AKSS clinical, HKA in both groups significantly improved at the final follow-up compared with those before operation. At the final follow-up, the UKA group was significantly better than the TKA group in AKSS functional and AKSS clinical, whereas HKA in the TKA group was better. At the final follow-up. TCVA and FCVA between the two groups were not significantly different, while TCPSA and FCPSA in the UKA group were significantly greater than the TKA group. No signs of progression of OA to the lateral compartment were observed.@*CONCLUSION@#Mixed phase 3 Oxford UKA in medial unicompartmental knee osteoarthritis was considerably better than TKA for less blood loss, shorter operation time, shorter hospital stay, rapid postoperative recovery, helping achieve satisfactory function, provided satisfactory outcome.

Comparison of clinical outcomes among total knee arthroplasties using posterior-stabilized, cruciate-retaining, bi-cruciate substituting, bi-cruciate retaining designs: a systematic review and network meta-analysis / 中华医学杂志(英文版)

BACKGROUND@#Despite the advent of innovative knee prosthesis design, a consistent first-option knee implant design in total knee arthroplasty (TKA) remained unsettled. This study aimed to compare the clinical effects among posterior-stabilized (PS), cruciate-retaining (CR), bi-cruciate substituting (BCS), and bi-cruciate retaining designs for primary TKA.@*METHODS@#Electronic databases were systematically searched to identify eligible randomized controlled trials (RCTs) and cohort studies from inception up to July 30, 2021. The primary outcomes were the range of knee motion (ROM), and the secondary outcomes were the patient-reported outcome measures (PROMs) and complication and revision rates. Confidence in evidence was assessed using Confidence in Network Meta-Analysis. The Bayesian network meta-analysis was performed for synthesis.@*RESULTS@#A total of 15 RCTs and 18 cohort studies involving 3520 knees were included. The heterogeneity and inconsistency were acceptable. There was a significant difference in ROM at the early follow-up when PS was compared with CR (mean difference [MD] = 3.17, 95% confidence interval [CI] 0.07, 7.18) and BCS was compared with CR (MD = 9.69, 95% CI 2.18, 17.51). But at the long-term follow-up, there was no significant difference in ROM in any one knee implant compared with the others. No significant increase was found in the PROMs and complication and revision rates at the final follow-up time.@*CONCLUSIONS@#At early follow-up after TKA, PS and BCS knee implants significantly outperform the CR knee implant in ROM. But in the long run, the available evidence suggests different knee prostheses could make no difference in clinical outcomes after TKA with extended follow-up.

Research progress of functional alignment robot assisted knee replacement / 中国骨伤

The correct alignment of the knee joint is considered to be one of the most influential factors in determining the long-term prognosis after total knee arthroplasty(TKA). In order to achieve the correct alignment goal, many different alignment concepts and surgical techniques have been established. For example, mechanical alignment(MA), kinematic alignment(KA) and functional alignment(FA) have their own characteristics. MA focuses on achieving neutral alignment of the limbs, parallel and equal bone gaps during stretching and flexion. KA aims to restore the patient 's natural joint line, make the joint level and angle normal and improve the physiological soft tissue balance, and strive to reproduce the normal knee function;among them, functional alignment(FA) developed with robot-assisted surgery technology is a relatively new alignment concept. It not only considers the alignment of the body, but also aims to achieve flexion and extension balance, while respecting the native soft tissue capsule. It not only restores the plane and slope of the in situ joint line accurately during the operation, but also takes into account the balance of soft tissue, which is a better alignment method. Therefore, it is of great significance to correctly construct the lower limb force line of patients, which is helpful to restore knee joint function, relieve pain symptoms and prolong the service life of prosthesi. However, compared with traditional TKA, the operation time of robot-assisted FA-TKA is prolonged, which means that the probability of postoperative infection will be greater. At present, most studies of FA technology report short-term results, and the long-term efficacy of patients is not clear. Therefore, long-term research results are needed to support the application of this technology. Therefore, the author makes a review on the research status of functional alignment.

Propensity score-matched study of uni-condylar arthroplasty in elderly patients with knee osteoarthritis / 中国骨伤

OBJECTIVE@#To investigate the clinical efficacy of unicompartmental knee arthroplasty (UKA) in the treatment of knee osteoarthritis in patients over 75 years old.@*METHODS@#The clinical efficacy of primary fixed platform UKA in patients with osteoarthritis, was retrospectively analyzed from October 2014 to November 2020. Age, body mass index (BMI), range of motion (ROM), preoperative joint function score, the quality of life score and other preoperative indicators were measured by propensity score matching (PSM). The patients were divided into elderly group (≥75 years old) and control group (<75 years old). Oxford knee score(OKS), Western Ontario McMaster Universities osteoarthritis index(WOMAC), Short Form-12 including physical component summary (PCS), mental component summary(MCS), minimal clinically important difference(MCID ) and clinical complications were evaluated preoperatively and postoperatively.@*RESULTS@#A total of 514 patients were analyzed, 428 patients fulfilled the inclusion criteria. A propensity-score matching study was conducted to eliminate confounding factors. After 1∶2 propensity match, there were 84 patients in elderly group (≥75 years), age ranged from 75 to 88 years old, with an average of (78.79±3.08) years old, and 168 patients in control group (<75 years), age ranged from 47 to 74 years old, with an average of (64.10±5.96)years old. The follow-up duration of two groups ranged from 12 to 84 months with an average of (29.35±16.52) months in elderly group, and 12 to 85 months with an average of (31.83±17.34) months in control group. There was only significant difference in age between the elderly and control groups preoperatively (P<0.01). Postoperatively, the elderly group showed significantly higher WOMAC (P<0.01) and lower SF-12 PCS scores (P<0.01) as compared to the control group. There was no significant difference between the elderly group and the control group in knee range of motion, OKS and the proportion of each scoring system reaching the minimum clinical difference value (P>0.05). In the aspect of preperative complications, the elderly group exhibited more surgical site complications and postoperative delirium compared to control group(P<0.05). The differences in other indicators including deep vein thrombosis, acute urinary retention, cardiovascular events, cerebrovascular events and radiolucent lines around prothesis were not statistically significant(P>0.05).@*CONCLUSION@#UKA in the treatment of elderly patients over 75 years old with knee osteoarthritis was safe and feasible, and could obtain satisfactory short-term efficacy.

Effect of prosthetic joint line installation height errors on insert wear in unicompartmental knee arthroplasty / 生物医学工程学杂志

The clinical performance and failure issues are significantly influenced by prosthetic malposition in unicompartmental knee arthroplasty (UKA). Uncertainty exists about the impact of the prosthetic joint line height in UKA on tibial insert wear. In this study, we combined the UKA musculoskeletal multibody dynamics model, finite element model and wear model to investigate the effects of seven joint line height cases of fixed UKA implant on postoperative insert contact mechanics, cumulative sliding distance, linear wear depth and volumetric wear. As the elevation of the joint line height in UKA, the medial contact force and the joint anterior-posterior translation during swing phase were increased, and further the maximum von Mises stress, contact stress, linear wear depth, cumulative sliding distance, and the volumetric wear also were increased. Furthermore, the wear area of the insert gradually shifted from the middle region to the rear. Compared to 0 mm joint line height, the maximum linear wear depth and volumetric wear were decreased by 7.9% and 6.8% at -2 mm joint line height, and by 23.7% and 20.6% at -6 mm joint line height, the maximum linear wear depth and volumetric wear increased by 10.7% and 5.9% at +2 mm joint line height, and by 24.1% and 35.7% at +6 mm joint line height, respectively. UKA prosthetic joint line installation errors can significantly affect the wear life of the polyethylene inserted articular surfaces. Therefore, it is conservatively recommended that clinicians limit intraoperative UKA joint line height errors to -2-+2 mm.

A multicenter randomized controlled trial of domestic robot-assisted and conventional total knee arthroplasty / 中国修复重建外科杂志

OBJECTIVE@#To investigate the accuracy, safety, and short-term effectiveness of a domestic robot-assisted system in total knee arthroplasty (TKA) by a multicenter randomized controlled trial.@*METHODS@#Between December 2021 and February 2023, 138 patients with knee osteoarthritis who received TKA in 5 clinical centers were prospectively collected, and 134 patients met the inclusion criteria were randomly assigned to either a trial group ( n=68) or a control group ( n=66). Seven patients had lost follow-up and missing data, so they were excluded and the remaining 127 patients were included for analysis, including 66 patients in the trial group and 61 patients in the control group. There was no significant difference ( P>0.05) in gender, age, body mass index, side, duration of osteoarthritis, Kellgren-Lawrence grading, preoperative Knee Society Score (KSS) and Western Ontario and McMaster University Osteoarthritis Index (WOMAC) score between the two groups. The trial group completed the TKA by domestic robot-assisted osteotomy according to the preoperative CT-based surgical planning. The control group was performed by traditional osteotomy plate combined with soft tissue release. Total operation time, osteotomy time of femoral/tibial side, intraoperative blood loss, and postoperative complications were recorded and compared between the two groups. The radiographs were taken at 5 and 90 days after operation, and hip-knee-ankle angle (HKA), lateral distal angle of femur (LDFA), and posterior tibial slope (PTS) were measured. The difference between the measured values of the above indexes at two time points after operation and the preoperative planning target values was calculated, and the absolute value (absolute error) was taken for comparison between the two groups. The postoperative recovery of lower limb alignment was judged and the accuracy was calculated. KSS score and WOMAC score were used to evaluate the knee joint function of patients before operation and at 90 days after operation. The improvement rates of KSS score and WOMAC score were calculated. The function, stability, and convenience of the robot-assisted system were evaluated by the surgeons.@*RESULTS@#The total operation time and femoral osteotomy time of the trial group were significantly longer than those of the control group ( P<0.05). There was no significant difference in the tibial osteotomy time and the amount of intraoperative blood loss between the two groups ( P>0.05). The incisions of both groups healed by first intention after operation, and there was no infection around the prosthesis. Nine patients in the trial group and 8 in the control group developed lower extremity vascular thrombosis, all of which were calf intermuscular venous thrombosis, and there was no significant difference in the incidence of complications ( P>0.05). All patients were followed up 90 days. There was no significant difference in KSS score and WOMAC score between the two groups at 90 days after operation ( P>0.05). There was significant difference in the improvement rate of KSS score between the two groups ( P<0.05), while there was no significant difference in the improvement rate of WOMAC score between the two groups ( P>0.05). Radiological results showed that the absolute errors of HKA and LDFA in the trial group were significantly smaller than those in the control group at 5 and 90 days after operation ( P<0.05), and the recovery accuracy of lower limb alignment was significantly higher than that in control group ( P<0.05). The absolute error of PTS in the trial group was significantly smaller than that in the control group at 5 days after operation ( P<0.05), but there was no significant difference at 90 days between the two groups ( P>0.05). The functional satisfaction rate of the robot-assisted system was 98.5% (65/66), and the satisfaction rates of stability and convenience were 100% (66/66).@*CONCLUSION@#Domestic robot-assisted TKA is a safe and effective surgical treatment for knee osteoarthritis, which can achieve favorable lower limb alignment reconstruction, precise implant of prosthesis, and satisfactory functional recovery.

Midterm Radiographic Results and Reoperations of Tantalum Trabecular Metal Cones in Knee Arthroplasties / Reoperações e resultados radiográficos de médio prazo do uso de cone de metal trabecular de tântalo nas artroplastias do joelho

Abstract Objective The management of bone loss represents a challenge in revisions of total knee arthroplasty (rTKA) and in complex primary total knee arthroplasties (TKAs). The purpose of the present study was to evaluate the midterm outcomes (5-year minimum follow-up) of knee reconstructions with tantalum trabecular metal (TM) cones on bone defects Anderson Orthopaedics Research Institute (AORI) 2 and 3. Materials and MethodsA retrospective analysis of the medical records of patients operated on between July 2008 and November 2014 was performed, collecting the following data: age, gender, laterality, body mass index, etiology of arthrosis, comorbidities, AORI classification of bone defects, causes for revision, readmissions, reoperations, perioperative and postoperative complications, radiographic signs of osteointegration, and maintenance of the TM support. Results A total of 11 patients with a mean follow-up of 7.28 years (standard deviation [SD] = 1.88; range = 5.12-10 years) was evaluated, with 1 patient operated upon for a primary arthroplasty, 6 for revision arthroplasties, and 4 for a second revision arthroplasty (re-revision). There were complications with the surgical wound, injury to the extensor mechanism and loosening of the femoral component in three of the patients that led to the necessity of four procedures due to complications with the surgical wound, injury to the extensor mechanism and loosening of the femoral component. Radiological signs of osteointegration of the trabecular cones were observed in all patients. We did not observe migration of the TM cones or the prosthetic components in the sample. Conclusion The tantalum metaphyseal cones were able to provide efficient structural support to prosthetic implants with radiographic signs of osteointegration in the medium term.

Resumo Objetivo O manejo da perda óssea representa um grande desafio em cirurgias de revisão de artroplastia do joelho (rATJ) e em artroplastias totais do joelho (ATJ) primárias complexas. O objetivo do presente estudo foi avaliar os resultados em médio prazo (seguimento mínimo de 5 anos) das reconstruções de joelho nas quais cones de metal trabecular (MT) de tântalo foram utilizados para tratamento de defeitos ósseos tipos 2 e 3, de acordo com a classificação proposta pela Anderson Orthopaedic Research Institute (AORI). Métodos Feita análise retrospectiva dos prontuários dos pacientes operados entre julho de 2008 e novembro de 2014, coletando-se os seguintes dados: idade, gênero, lateralidade, índice de massa corporal, etiologia da artrose, comorbidade, classificação AORI da falha óssea, causa da revisão da artroplastia total do joelho, reinternações, reoperações, complicações peri- e pós-operatórias, ocorrência de osteointegração radiográfica e manutenção da função de suporte do MT. Resultados Foram avaliados 11 pacientes com tempo médio de seguimento de 7,28 anos (desvio padrão [DP] = 1,88; variação = 5,12-10 anos), sendo que 1 paciente foi submetido a artroplastia primária, 6 a artroplastia de revisão e 4 a segunda revisão de artroplastia (re-revisão). Três pacientes necessitaram de quatro reoperações devido a complicações com a ferida operatória, a lesão do mecanismo extensor e a soltura do componente femoral. Sinais de osteointegração dos cones trabeculados foram observados em todos os pacientes. Não observamos migração do cone de MT ou dos componentes protéticos. Conclusão Os cones metafisários de tântalo foram capazes de prover suporte estrutural eficiente aos implantes protéticos com sinais radiográficos de osteointegração em médio prazo.

Effect of computer navigation gap balance technology on lower limb recovery after total knee arthroplasty / 中国骨伤

OBJECTIVE@#To investigate the effect of computer navigation gap balance technology on the recovery of lower limb function after total knee arthroplasty.@*METHODS@#The clinical data of 106 patients with knee osteoarthritis (OA) who underwent total knee arthroplasty from July 2018 to June 2019 were analyzed retrospectively. They were divided into measurement osteotomy group and space balance group according to different osteotomy techniques during total knee arthroplasty. There were 61 cases in osteotomy group, 24 males and 37 females;The age ranged from 45 to 77(63.35±4.26) years;According to K-L classification, 41 cases were grade Ⅲ and 20 cases were grade Ⅳ. intraoperative measurement osteotomy was performed. There were 45 cases in the gap balance group, 17 males and 28 females;Age 45 to 78(64.03±4.31) years;According to K-L classification, 29 cases were classified as grade Ⅲ and 16 cases as grade Ⅳ. computer navigation gap balance technology was implemented. The amount of intraoperative bleeding, operation time, incision length, hospital stay and postoperative complications were compared between two groups. The clinical efficacy was evaluated by Knee Society score(KSS) before operation and 12 months after operation.@*RESULTS@#Total of 106 patients were followed up for 12 to 18(20.38±3.25) months. There were significant differences in intraoperative bleeding and operation time between two groups(P<0.05). There was no significant difference in incision length and hospital stay between the two groups(P>0.05). At 12 months after operation, the total score of KSS in the gap balance group (173.59±14.50) was better than that in the osteotomy group (164.95±12.10)(P<0.05). There were no serious complications of poor prosthesis loosening between two groups during follow-up, and there was no significant difference in the incidence of other complications between two groups(P>0.05).@*CONCLUSION@#The application of computer navigation gap balance technology in total knee arthroplasty is conducive to the recovery of lower limb function in patients with OA, and there are no serious adverse complications and high safety.

Coronal curvature of tibial leads to malalignment of tibial prosthesis after total knee arthroplasty / 中国骨伤

OBJECTIVE@#To investigate the effect of tibial coronal curvature on the alignment of tibial prosthesis in patients undergoing total knee arthroplasty (TKA).@*METHODS@#From July 2019 to April 2021, 100 patients with knee osteoarthritis were treated with total knee arthroplasty. Before operation, the full-length films of lower limbs were taken and the tibial bowing angle(TBA) was measured. TBA more than 2° was tibial bending, which was divided into tibial bending group and non bending group. There were 40 cases in tibial bending group, 9 males and 31 females, aged 56 to 84 years old with an average of (69.22±7.10) years. There were 60 cases in the non bending group, 19 males and 41 females, aged from 51 to 87 years old with an average of (70.80±7.21) years. The preoperative tibial length (TL) and medial proximal tibial angle (MPTA) were measured and compared between the two groups. The full-length X-rays of the lower limbs were taken again 3 days to 1 week after operation. The medial angle of the tibial component coronal aligement angle (TCCA) and the outilier rate of force line of the tibial prosthesis were measured and compared between the two groups. Pearson method was used to analyze the correlation between TCCA and age, TCCA and height, TCCA and weight, TCCA and BMI, TCCA and TBA, TCCA and TL, TCCA and MPTA; Spearman method was used to analyze the correlation between TCCA and gender, TCCA and Kellgren-Lawrence(K-L) grade.@*RESULTS@#All 100 patients successfully completed the operation and obtained satisfactory full-length X-rays in standing position. There was no significant difference in TL, MPTA and TCCA between bending group and non bending group(P>0.05). The outilier rate of force line in tibial bending group was 22.5%, and that in non bending group was 6.67%, the difference was statistically significant(P<0.05). The correlation study found that TCCA was strongly correlated with TBA(r=-0.702, P<0.01), weakly correlated with MPTA(r=0.311, P<0.01), and had no correlation with other parameters(P>0.05).@*CONCLUSION@#In patients with knee osteoarthritis undergoing total knee arthroplasty, tibial bending will lead to poor force line of tibial prosthesis. During operation, attention should be paid to osteotomy of proximal tibial vertical tibial mechanical axis and correct installation of prosthesis to avoid poor alignment of prosthesis.

META analysis of mobile bearing and fixed bearing unicondyle replacement for medial knee osteoarthritis / 中国骨伤

OBJECTIVE@#To evaluate of the clinical effects of mobile-bearing(MB) and fixed-bearing(FB) unicompartmental knee arthroplasty(UKA) in the treatment of knee osteoarthritis by Meta-analysis.@*METHODS@#The literature on FB UKA and MB UKA in the treatment of knee osteoarthritis in PubMed, CNKI, Wanfang, Cochrane and EMBASE database were searched by computer from January 2000 to April 2020. According to the inclusion and exclusion criteria, two authors were selected independently and the selected literature was evaluated for quality.After literature data were extracted, Review Manager 5.3 software was used to analyze knee function score, postoperative activity, revision rate, polyethylene wear rate, pad dislocation, aseptic loosening, postoperative pain, knee arthritis progression, mechanical shaft alignment of lower limbs, and imaging clarity line respectively.@*RESULTS@#A total of 13 literatures were included in this meta-analysis, including 2 randomized controlled studies and 11 cohort studies. A total of 1 871 patients were included, including 913 in FB UKA group and 958 in MB UKA group. Meta analysis results showed that:postoperative knee joint function score[MD=-0.84, 95%CI(-1.46, -0.21), P=0.008] and postoperative knee joint range of motion [MD=-1.51, 95%CI(-2.84, -0.18), P=0.03] in FB UKA group were better than those in MB UKA group. Compared with FB UKA group, MB UKA group had a higher lower limb mechanical axis alignment rate[OR=2.08, 95%CI(1.27, 3.39), P=0.003], and the wear rate of polyethylene [OR=0.11, 95%CI(0.01, 0.91), P=0.04] was lower. There were no differences between two groups in the renovation rate [OR=1.16, 95%CI(0.75, 1.80), P=0.50), liner dislocation rate[OR=3.78, 95%CI(0.93, 15.29), P=0.06], aseptic loosening [OR=2.11, 95%CI(0.81, 5.51), P=0.13], postoperative pain[OR=1.13, 95%CI(0.37, 3.43), P=0.83], osteoarthritis progression[OR=1.28, 95%CI(0.67, 2.47), P=0.46)and imaging radiolucent line[OR=1.62, 95%CI(0.09, 30.22), P=0.75].@*CONCLUSION@#FB UKA has a higher postoperative functional score and range of motion.MB UKA has more advantages in the correction of lower limb mechanical axis, and the wear rate of polyethylene is also lower. There was no significant difference between the two groups in revision rate, dislocation of the liner, aseptic loosening, postoperative pain, progression of osteoarthritis, and postoperative translucency.

Rotational alignment of the tibial component in total knee arthroplasty:a narrative review / 中华外科杂志

Component malrotation is one of the major causes of failure in total knee arthroplasty.Based on previous researches,Insall line has excessive external rotation tendency.Although Akagi line is the most recognized anatomical axis at present,it still has a certain tendency of internal rotation.The tibial posterior condylar axis is not suitable for symmetrical component and yet the Curve-on-Curve technique is not suitable for anatomic component.In addition,reference to any fixed anatomical markers cannot ensure the rotation consistency of tibiofemoral component in extension position.Although range of motion technique is beneficial to tibiofemoral rotation synchronization,its clinical effect seems to be unstable.Nevertheless,Patients can obtain good postoperative results with all major techniques.Before the recognized "gold standard" is defined,orthopedic surgeons can determine the rotation alignment of tibial component according to their most accustomed surgical method.With a deeper understanding of knee anatomy,biomechanics and kinematics,digital assistive technology may be expected to become a breakthrough in the tibial rotational alignment.

Genu valgo artrósico severo: Prótesis de estabilidad aumentada en artroplastia primaria / The severe valgus knee: Total knee arthroplasty with a constrained prosthesis

Objetivo El genu valgo artrósico severo (> 20°) puede presentar distintos grados de insuficiencia del ligamento colateral medial e inestabilidad articular. El objetivo de este trabajo retrospectivo evalúa nuestra experiencia en el tratamiento del genu valgo severo con prótesis de estabilidad aumentada y propone un método para la evaluación y clasificación del genu valgo artrósico. Material y métodos A 27 pacientes (28 rodillas) con genu valgo artrósico severo se les realizó una artroplastia total de rodilla primaria con un implante de estabilidad aumentada, y un seguimiento promedio de 6.2 años. Se confeccionó una nueva clasificación del genu valgo artrósico que contempla la suficiencia ligamentaria y por lo tanto relaciona el tipo de rodilla con el tipo de implante necesario. Resultados Se utilizó una prótesis constreñida en 17 pacientes con un eje promedio de 22,7° y el ligamento colateral medial atenuado. En 11 casos con un eje promedio de 28,1°, LCM incompetente y/o recurvatum, se optó por bisagras rotatorias. Se confeccionó una nueva clasificación del genu valgo artrósico que considera el desgaste y estabilidad articular, el grado de deformidad de la rodilla y la suficiencia ligamentaria. Discusión Las prótesis constreñidas deben utilizarse en pacientes que presenten inestabilidad exclusivamente en el plano coronal, aún en genu valgo severo, con LCM atenuado. Debe reservarse el uso de bisagras rotatorias a aquellos pacientes que presentan incompetencia ligamentaria, inestabilidad combinada (recurvatum) y/o déficit neuro-muscular severo.

Purpose This retrospective level 2 analysis evaluates the prosthesis type selected in our department for the treatment of the severe valgus knee and proposes a new classification for the valgus knee osteoarthritis. Material and methods A total knee arthroplasty with a constrained or hinged knee prosthesis was performed in 28 valgus knees. The average follow-up was 6.2 years. A new classification that considerates the ligament sufficiency status was developed in order to relate the different knee types with the different type of eventually needed implants. Results Constrained prosthesis was used in 17 patients with an attenuated medial collateral ligament, and a rotating hinge in 11 patients with incompetent medial collateral ligament and/or recurvatum. The postoperatory Knee Society Score was of 85 points. The valgus knee was classified in 5 types considering the knee valgus deformity, the ligament sufficiency and joint stability and wear. Discussion The classification proposed clearly defines the ligament status and valgus knee types, and it seems to be a comprehensive tool to select the appropriate prosthesis. Constrained prosthesis must be used on patients who present coronal instability with attenuated medial collateral ligament. Rotating hinges must be reserved for those patients who have medial collateral ligament incompetence, recurvatum, combined instability and/or severe muscular deficiency.