The Brazilian version of the High-Activity Arthroplasty Score: cross-cultural adaptation

ABSTRACT BACKGROUND: The High Activity Arthroplasty Score (HAAS) is a self-administered questionnaire, developed in British English, that reliably and validly measures the levels of sports activities in patients following hip and knee arthroplasty surgery. OBJECTIVE: To cross-culturally adapt the HAAS to Brazilian Portuguese language. DESIGN AND SETTING: A cross-sectional study was conducted at a public university hospital in Brazil. METHODS: The Brazilian version of the HAAS was created through a six-step process: translation, synthesis, committee review, pretesting, back-translation, and submission to developers. The translation step was conducted by two independent bilingual translators, both native speakers of Brazilian Portuguese. The back-translation was performed by an independent translator, a native speaker of British English. To ensure the questionnaire's comprehensibility, 46 volunteers (51% men; average age 34-63) participated in the pre-testing step. RESULTS: The cross-cultural adaptation process necessitated modifications to certain terms and expressions to achieve cultural equivalence with the original HAAS. CONCLUSION: The HAAS has been translated from English into Brazilian Portuguese and culturally adapted for Brazil. The validation process for HAAS-Brazil is currently underway.

Comparative Analysis of the Tibial Component Migration After Cemented and Uncemented Total Knee Arthroplasty with a Hydroxyapatite Coating in Two, Five, and Ten Years: A Meta-Analysis / Análise comparativa da migração do componente tibial da artroplastia total do joelho cimentada versus não cimentada versus não cimentada com revestimento de hidroxapatita por dois, cinco e dez anos: uma metanálise

Abstract Objective This study evaluated and compared the tibial component migration in cemented and uncemented total knee arthroplasty (TKA) with no hydroxyapatite coating 2, 5, and 10 years after surgery. Methods This meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) based on PubMed and MeSH database queries from June to July 2022. Results The meta-analysis included eight randomized clinical studies evaluating 668 knees undergoing TKA. The maximum total point motion (MTPM) in cemented TKAs was higher in 5 years, with a mean value of 0.67 mm (95% confidence interval [CI], 0.52 to 0.87). Uncemented TKAs also presented higher mean MTPM in 5 years (1 mm; 95% CI, 0.82 to 1.22). Uncemented coated ATKs had a higher mean MTPM in 10 years (1.30 mm; 95% CI, 0.70 to 2.39). MTPM was statistically similar in the short- and long-term for cemented and uncemented techniques, with a standardized mean difference of -0.65 (95% CI, -1.65 to 0.35). Conclusion Tibial component migration in TKA was statistically similar at 2, 5, and 10 years in cemented and uncemented techniques, either with or without coating. However, due to the scarce literature, further studies are required with a longer follow-up time.

Resumo Objetivo Avaliar e comparar a migração obtida pelo componente tibial na Artroplastia Total de Joelho (ATJ) cimentada, não cimentada sem revestimento e não cimentada com revestimento de hidroxapatita aos 2, 5 e 10 anos pós operatório. Métodos Esta metanálise foi conduzida de acordo com o Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Foi realizada busca a partir das bases de dados PubMed e MeSH no período de junho a julho de 2022. Resultados Oito ensaios clínicos randomizados foram incluídos. Um total de 668 joelhos submetidos a ATJ foram avaliados. Observou-se que a média de Maximun Total Point Motion (MTPM) nas ATJ cimentada foi maior em experimentos com cinco anos com média de 0,67 mm (IC95% - 0,52 a 0,87), as ATJ não cimentadas com revestimento de hidroxapatita também obtiveram maior média neste período (1mm; IC95% - 0,82 a 1,22). Em ATJ não cimentada sem revestimento o maior MTPM médio ocorreu no período de 10 anos (1,30mm; IC95% - 0,70 a 2,39). O MTPM foi estatisticamente semelhante no curto e longo prazo ao comparar as técnicas cimentada e não cimentada, com diferença média padronizada -0,65 (IC95%, -1,65 a 0,35). Conclusão A migração obtida pelo componente tibial na artroplastia total de joelho (ATJ) foi estatisticamente semelhante em 2, 5 e 10 anos ao comparar as técnicas cimentada e não cimentada (com e sem revestimento). Entretanto, devido ao pequeno número de artigos existentes, são necessários mais estudos clínicos sobre tais técnicas e com maior tempo de acompanhamento.

Intravenous Use of Tranexamic Acid in Total Knee Arthroplasty with no Tourniquet / O uso endovenoso de ácido tranexâmico na artroplastia total de joelho sem uso de torniquete

Abstract Objective: To identify blood transfusion requirements and postoperative complications in patients undergoing total knee arthroplasty (TKA) with no tourniquet and intraoperative intravenous administration of tranexamic acid. Methods: This retrospective observational study analyzed 49 preopeative and postoperative medical records of patients undergoing TKA. A paired t-test compared changes in hemoglobin (HB) and packed cell volume (PCV), and an independent t-test with Welch correction compared HB and PCV changes between genders. A Spearman correlation test determined associations between age and days of postoperative hospitalization with HB and PCV changes. The significance level adopted was p < 0.05. Results: The patients' mean age was 71.9 ± 6.7 years; most subjects were women (73.5%). The right side (59.2%) was the most affected. Only one participant required a blood transfusion, while three subjects had complications during the postoperative follow-up. No patient had a thromboembolic event. The median length of postoperative hospital stay was 2 days (interquartile range [IQR] = 1.0). There were reductions in HB and PCV levels between the pre-operative and postoperative period, and female patients had a higher HB reduction. Conclusion: TKA with tranexamic acid and no tourniquet did not cause significant postoperative complications or require blood transfusions.

Resumo Objetivo: Identificar a necessidade de transfusão sanguínea e intercorrências inerentes ao pós-operatório de pacientes submetidos à artroplastia total de joelho (ATJ), a partir de manejos realizados sem o uso de torniquete e com administração de ácido tranexâmico endovenoso intra-operatório. Métodos: Trata-se de um estudo observacional retrospectivo, a partir da observação de 49 prontuários médicos de pacientes submetidos à ATJ em pré e pós-operatório. Foi utilizado o teste t pareado para fazer comparações das modificações de hemoglobina (HB) e hematócrito (HT) e o teste t independente com correção de Welch para comparar as modificações de HB e HT entre os sexos. As associações de idade e dias de internação no pós-operatório com as modificações de HB e HT foram testadas pela correlação de Spearman. O nível de significância adotado foi p < 0,05. Resultados: Os pacientes apresentaram idade média de 71,9 ± 6,7 anos. A maioria da amostra foi composta por mulheres (73,5%) e o lado direito (59,2%) foi o mais acometido. Apenas um participante necessitou de transfusão de sangue e três participantes apresentaram intercorrências durante o seguimento pós-operatório. Nenhum paciente apresentou evento tromboembólico. A mediana da duração da internação no pós-operatório foi de dois dias (IIQ= 1,0). Verificaram-se reduções nas dosagens de HB e HT entre o pré e pós-operatório, e pacientes do sexo feminino apresentaram maior redução de HB. Conclusão: ATJ com uso de ácido tranexâmico e sem uso de torniquete não acarretou complicações pós-operatórias ou necessidade de transfusão sanguínea significativas.

Comparison of Blood Loss with the Use of Intravenous and Intraarticular Tranexamic Acid Versus Isolated Intraarticular in Primary Knee Arthroplasty / Comparação da perda sanguínea com a utilização do ácido tranexâmico endovenoso e intra-articular versus intra-articular isolado em artroplastia primária de joelho

Abstract Objective The objective of this work is to compare blood loss during primary knee arthroplasty with the use of intravenous and intraarticular (IV + IA) tranexamic acid versus intraarticular (IA) tranexamic acid alone. Methods This is a randomized, double-blind clinical trial. Patients with indication for primary total knee arthroplasty were recruited in a specialized clinic, where they were operated by the same surgeon, always using the same surgical technique. Thirty patients were allocated in the IV + IA tranexamic acid group and 30 patients in the IA tranexamic acid group, according to randomization. Blood loss was compared through hemoglobin, hematocrit, drain volume, and blood loss estimation (Gross and Nadler calculus). Results After collection, data from 40 patients were analyzed, 22 in the IA group and 18 in the IV +IA group. There were 20 losses due to collection error. Between groups IA and IV + IA, there were no significant differences in 24 hours between hemoglobin levels (10.56 vs. 10.65 g/dL; F1.39 = 0.63, p =0.429), erythrocyte (3.63 vs. 3.73 million/mm³; F1.39 = 0.90, p = 0.346); hematocrit (32.14 vs. 32.60%; F1.39 = 1.39, p = 0.240); drainage volume (197.0 vs. 173.6 mL; F1.39 = 3.38 p = 0.069); and estimated blood loss (1,002.5 vs. 980.1; F1.39 =0.09, p = 0.770). The same occurred in comparisons conducted after 48 hours postoperatively. Time was a significant factor for the change of all outcome variables. However, the treatment did not modify the effect of time on these outcomes. No individual presented any thromboembolic event during the work period. Conclusions The use of IV + IA tranexamic acid showed no advantage in reducing blood loss when compared to the use of IA tranexamic acid alone in primary knee arthroplasties. This technique proved to be safe, since no thromboembolic event occurred during the development of the work.

Resumo Objetivo O objetivo desse trabalho é comparar a perda sanguínea durante a artroplastia primária de joelho, com a utilização do ácido tranexâmico endovenoso e intra-articular (EV + IA) versus intra-articular (IA) isolado. Métodos Trata-se de um ensaio clínico randomizado, duplo cego. Pacientes com indicação de artroplastia total primária de joelho foram captados em clínica especializada, onde foram operados pelo mesmo cirurgião, utilizando sempre a mesma técnica cirúrgica. Trinta pacientes foram alocados no grupo ácido tranexâmico EV + IA e 30 pacientes, no grupo IA, conforme randomização. Foi comparada a perda sanguínea através dos níveis de hemoglobina, hematócrito, volume do dreno e estimativa da perda sanguínea (EBL) (cálculo de Gross e Nadler). Resultados Após a coleta, foram analisados os dados de 40 pacientes, sendo 22 do grupo IA isolado e 18 do grupo EV + IA. Ocorreram 20 perdas por erro de coleta. Entre os grupos IA e EV + IA, não ocorreram diferenças significativas em 24 horas entre os níveis de hemoglobina (10,56 vs. 10,65 g/dL; F1,39 =0,63, p = 0,429), eritrócito (3,63 vs. 3,73 milhões/mm3; F1,39 = 0,90, p =0,346), hematócrito (32,14 vs. 32,60%; F1,39 = 1,39; p=0,240), volume de dreno (197,0 vs. 173,6 mL; F1,39 = 3,38; p =0,069) e estimativa de perda sanguínea (EBL) (1.002,5 vs. 980,1; F1,39 = 0,09; p =0,770). O mesmo ocorreu nas comparações realizadas 48 horas pós-operatório. O tempo foi fator significativo para a mudança de todas as variáveis de desfecho. Porém, o tratamento não modificou o efeito do tempo nesses desfechos. Nenhum indivíduo apresentou qualquer evento tromboembólico durante o período do trabalho. Conclusões O uso do ácido tranexâmico EV + IA não demonstrou vantagem em redução de perda sanguínea quando comparado ao uso de ácido tranexâmico IA isolado nas artroplastias primárias de joelho. Esta técnica demonstrou-se segura, visto que nenhum evento trombo-embólico ocorreu durante o desenvolvimento do trabalho.

Quality of Life and Satisfaction in Patients Above and Under 65 Years Old Submitted to Total Knee Arthroplasty / Qualidade de vida e satisfação de pacientes com idade superior ou inferior a 65 anos submetidos a artroplastia total de joelho

Abstract Objective To compare the level of quality of life and satisfaction after two years of total knee arthroplasties between individuals above and below 65 years of age and to identify predictor factors of poor clinical outcome and low level of satisfaction in patients undergoing arthroplasty. Methods This is a retrospective cohort with data from patients diagnosed with knee osteoarthritis submitted to primary total knee arthroplasty from 2014 to 2018 (n= 190). Clinical outcomes were assessed using the following scores: visual analog scale (VAS) of pain, EQ-5D-3L and EUROQOL-VAS (quality of life scales), patient satisfaction level, and functional scale of the Knee Injury and Osteoarthritis Outcome Score (KOOS), collected through a questionnaire applied preoperatively, as well as 1, 3, 12 and 24 months after surgery. Results Patients < 65 years old presented significantly lower values (clinical worsening) in KOOS-pain and KOOS-symptoms. There are no differences in the principal clinical scores that assess pain, function, and quality of life after the procedure, as well as in the rate of satisfaction with the procedure, among patients < 65 years old when compared with patients ≥ 65 years old. It was also observed that patients who were not satisfied with the procedure in the 24-month evaluation presented clinical results in some analyzed scores (KOOS-pain and EQ-VAS) similar to patients who declared themselves satisfied. Conclusion Scores that assess pain, function, quality of life, as well as satisfaction rate are similar between patients < 65 years old and those ≥ 65 years old.

Resumo Objetivo Comparar a qualidade de vida e satisfação 2 anos após a artroplastia total de joelho em indivíduos com idade ≥ e < 65 anos e identificar fatores preditivos de pior evolução clínica e baixo nível de satisfação nestes pacientes. Métodos Trata-se de uma coorte retrospectiva de dados de pacientes com diagnóstico de osteoartrite de joelho submetidos a artroplastia total primária de joelho entre 2014 e 2018 (n= 190). Os resultados clínicos foram avaliados de acordo com os seguintes escores: escala visual analógica (EVA) de dor, EQ-5D-3L e EUROQOL-VAS (escalas de qualidade de vida), nível de satisfação do paciente e escala funcional do Knee Injury and Osteoarthritis Outcome Score (KOOS, na sigla em inglês). Estes dados foram coletados por meio de questionário aplicado no período pré-operatório e 1, 3, 12 e 24 meses após a cirurgia. Resultados Os pacientes < 65 anos apresentaram valores significativamente menores (piora clínica) nas escalas KOOS-dor e KOOS-sintomas. Não houve diferenças nas principais pontuações clínicas de dor, função e qualidade de vida após o procedimento, nem no índice de satisfação com a cirurgia, entre pacientes < 65 anos em comparação com aqueles ≥ 65 anos. Observamos também que os pacientes não satisfeitos com o procedimento à avaliação de 24 meses apresentaram resultados clínicos em alguns escores analisados (KOOS-dor e EQ-VAS) semelhantes aos dos pacientes que se declararam satisfeitos. Conclusão Os escores que avaliam dor, função, qualidade de vida e índice de satisfação são semelhantes entre os pacientes < 65 anos e aqueles ≥ 65 anos.

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.

Effect of esketamine on extremity ischemia-reperfusion-induced lung injury in elderly patients undergoing total knee replacement / 中华麻醉学杂志

Objective:To evaluate the effect of esketamine on extremity ischemia-reperfusion-induced lung injury in elderly patients undergoing total knee replacement.Methods:Sixty elderly patients of both sexes, aged 65-80 yr, with body mass index <35 kg/m 2, of American Society of Anesthesiologists Physical Status classification Ⅱ or Ⅲ, scheduled for elective unilateral total knee replacement under neuraxial anesthesia, were divided into 2 groups according to the random number table method: control group (C group) and esketamine group (S group), with 30 cases in each group. Esketamine 0.3 mg/kg was intravenously infused before tourniquet inflation in group S. Immediately after the end of operation, the two groups received adductor block with 0.5% ropivacaine 15 ml under ultrasound guidance. And then patient-controlled intravenous analgesia was performed, patient-controlled intravenous analgesia solution included sufentanil 1.5 μg/kg in 100 ml of normal saline in group C and sufentanil 1.5 μg/kg and esketamine 0.75 mg/kg in 100 ml of normal saline in group S. The background infusion rate was 1.5 ml/h, the patient-controlled analgesia dose was 1.5 ml, and the lockout interval was 15 min in the two groups. When the visual analogue scale score at rest≥ 4 points within 3 days after surgery, ketorolac tromethamine 30 mg was intravenously injected for rescue analgesia. Blood samples from the radial artery were collected for blood gas analysis at 30 min before tourniquet inflation(T 0), 30 min after tourniquet inflation(T 1), and 3 min, 30 min and 24 h (T 4) after tourniquet release (T 2-4), and PaO 2 and PaCO 2 were recorded. The alveola-arterial oxygen partial pressure difference, oxygenation index and respiratory index were calculated. Peripheral venous blood samples were collected at T 0, T 3 and T 4 for determination of serum endothelin-1 and malondialdehyde by enzyme-linked immunosorbent assay. The requirement for rescue analgesia and occurrence of dizziness, hallucinations and pulmonary complications within 3 days after surgery were recorded. Results:Compared with group C, alveola-arterial oxygen partial pressure difference was significantly decreased at T 1-3, respiratory index was decreased, oxygenation index was increased at T 2, 3, and serum endothelin-1 and malondialdehyde concentrations were decreased at T 3, 4, and the rate of postoperative rescue analgesia was decreased in group S( P<0.05). There was no significant difference in the incidence of postoperative dizziness, hallucinations, and pulmonary complications between the two groups ( P>0.05). Conclusions:Esketamine can reduce extremity ischemia-reperfusion-induced lung injury in elderly patients undergoing total knee replacement, and the mechanism may be related to regulating vascular endothelial function and reducing lipid peroxidation.

Analysis on effective concentrations and adverse reactions of Ropivacaine in the modified fascial iliac compartment block for pain relief after total knee arthroplasty in elderly patients / 中华老年医学杂志

Objective:To identify the effective concentrations of Ropivacaine in the modified fascial iliac compartment block(FICB)that would not affect the movement of the affected limb but would offer effective pain relief after total knee arthroplasty(TKA)in elderly patients.In addition, adverse reactions within 24 hours of FICB were examined.Methods:This study was a prospective, single-arm sequential trial.Forty-five elderly patients treated with TKA at the First Affiliated Hospital of Soochow University between September 2021 and March 2022 were selected, with an American Society of Anesthesiologists(ASA)score of Ⅰ or Ⅱ.All patients were given ultrasound-guided FICB on the surgical side under general anesthesia and 10 minutes before the operation, and the injection volume was 30 ml.According to preliminary experiments and relevant literature, the initial concentration of Ropivacaine was 0.1%, and the concentration for the next patient was determined using a modified Dixon sequential method.If the quadriceps femoris muscle strength score of the first patient was ≥4, there was no resting pain[visual analogue scale(VAS)score ≤1], and the VAS score during activity was ≤3, the concentration for the next patient would be reduced.Conversely, the concentration would be increased.The Ropivacaine concentration was increased or decreased by 0.01% each time and the trial would be stopped after 12 reentries.The median effective concentration(ED50), 95% effective concentration(ED95)and corresponding 95% confidence interval(CI)of ropivacaine were calculated using the probit model.Meanwhile, adverse reactions within 24 hours of FICB were monitored.Results:Of 43 elderly patients who completed the trial, the intervention was effective in 23 and ineffective in 20.While ensuring that postoperative limb movement in elderly patients was not affected, a single injection of 30 ml ropivacaine through FICB was able to effectively inhibit postoperative pain, and the ED50 and ED95 of ropivacaine were 0.072%(95% CI: 0.065%-0.078%)and 0.093%(95% CI: 0.084%-0.124%), respectively.Within 24 hours of FICB, 2 patients had lower limb weakness and could not get out of bed and walk, and 5 patients had severe pain and needed additional analgesics.No other adverse reactions were found. Conclusions:The effective ED50 and ED95 of Ropivacaine for postoperative pain relief in elderly patients after TKA are 0.072% and 0.093%, respectively.And the incidence of adverse reactions is low.

Application of multimodal low opioid combined with saphenous nerve block analgesia in elderly patients undergoing knee arthroplasty / 中华老年医学杂志

Objective:To investigate the clinical application of multimodal low-opioid combined with saphenous nerve block analgesia in elderly patients undergoing knee arthroplasty.Methods:This study is a randomized controlled study.A total of 60 elderly patients who underwent elective knee arthroplasty in the Department of Orthopedics, the First Hospital of Shanxi Medical University from January 2021 to December 2021 were selected and divided into 2 groups by numerical randomization: mode low opioid analgesia regimen group(observation group)and traditional analgesia regimen group(control group), 30 cases in each group.Observation group: (1)Preemptive analgesia: Oral celecoxib 200 mg, qd.from 3 days before surgery, the mini-mental state examination(MMSE)score was used to evaluate the cognitive function; (2)Intraoperative analgesia: After the prosthesis was installed, choose to inject analgesics around the knee joint(ropivacaine 200 mg, morphine 5 mg, epinephrine 0.25 mg, dexamethasone 5 mg/100 ml normal saline, also known as "cocktail" solution); (3)Postoperative analgesia: After the operation, continuous saphenous nerve block(0.2% ropivacaine, 2 ml/h)was performed under ultrasound guidance, and the dose of nerve block was adjusted according to the degree of rehabilitation training.Control group: no special treatment before and during the operation, traditional postoperative patient-controlled intravenous analgesia(PCIA)was used after the operation, the formula WAs as follows: sufentanil(2 μg/kg)+ flurbiprofen axetil(200-300 mg)+ Tropisetron(5-10 mg). The numerical rating scale(NRS)scores were observed and recorded 1 day before surgery, 6, 12, 24, and 48 hours after surgery; the time of the first active straight leg raising after surgery, the time of landing; the range of motion(ROM)of the knee joint 3, 7, and 14 days after surgery; the American Hospital for Special Surgery Knee Score(HSS)at 14 days, 1, 3, and 6 months after surgery; serum substance P(SP)and interleukin-6(IL-6)concentrations 1 day before surgery and 48 hours after surgery, and adverse events were recorded.Results:Compared with the control group, the patients in the observation group had lower NRS scores at 6, 12, 24, and 48 hours after the operation( t=27.705, 27.532, 21.739, 25.780, all P<0.05); the first active straight leg raising time and the time of landing earlier after the operation, and the knee joint at 3, 7, and 14 days after the operation, the range of motion(ROM)was better( t=35.496, 43.716, 3.766, 5.216, 6.009, all P<0.05). And the American hospital for special surgery knee score(HSS)was higher at 14 days, 1 month, and 3 months after surgery( t=19.247, 32.337, 22.651, all P<0.05), but there was no significant difference at 6 months after surgery.Simultaneously, the serum SP and IL-6 concentrations in the observation group 48 h after the operation were (431.0±11.3)ng/L and(11.9±2.7)ng/L, respectively.Compared with the control group(442.5±15.6)ng/L, (14.4±2.9)ng/L( t=5.362, 4.144, both P<0.05). Compared with the control group, which were lower than those in the incidence of postoperative nausea and vomiting was lower, the length of hospital stay was shorter in the observation group( χ2=4.630, t=3.311, P=0.031, 0.002), and the other indicators had no statistical differences(all P>0.05). Conclusions:Multimodal low-opioid combined with saphenous nerve block analgesia can significantly reduce perioperative pain in elderly patients undergoing knee arthroplasty, improve early postoperative mobility, and speed up postoperative functional recovery.

The application of restricted kinematic alignment in total knee arthroplasty / 中华骨科杂志

Objective:To investigate the feasibility and therapeutic effect of total knee arthroplasty (TKA) with cruciate-retaining (CR) prosthesis by using FEM-X1 femoral extramedullary positioning instrument based on the theory of restricted kinematic alignment (rKA).Methods:Thirty five cases who underwent total knee arthroplasty in Nanjing Drum Tower Hospital from November 2019 to December 2020 were retrospectively analyzed, including 7 males and 28 females with an average age of 71± 8 years (ranging from 55 to 85 years) Following the guidance of rKA alignment, the FEM-X1 femoral extramedullary positioning instrument was used for TKA with CR prosthesis. Before the operation, the full-length lower limb radiographs of both anteroposterior and lateral views were taken in a standing position for preoperative assessment of lateral distal femoral angle (LDFA), the medial proximal tibial angle (MPTA) and hip-knee-ankle angle (HKA). According to the principle of rKA alignment, the target LDFA, MPTA and HKA were calculated. The proximal end of tibia and distal end of femur were cut using extramedullary positioning instrument respectively. The posterior femoral condyle was cut according to the tibial plateau and mediolateral soft tissue tension. The prosthesis was installed after osteotomy. The release of collateral ligaments, PCL function, release of PCL, patellofemoral trajectory, release of patellofemoral support band, the amount of blood loss and time of operation were recorded. Postoperative LDFA, MPTA, HKA, and posterior slope angle of tibial prosthesis were measured on X-ray images. The Knee Society Score (KSS) was used for functional evaluation.Results:Thirty five cases of TKA with CR prosthesis following rKA alignment were successfully completed. The operation time was 100 (90, 110) min, and the blood loss was 100 (100, 200) ml. 30 of them were followed up for 12.5±0.7 months (ranging from 12 to 14 months). The pre-operative and post-operative LDFA were 1.0°(-2.0°, 4.0°), 0°(-2.0°, 2.0°), MPTA were -4.0°(-5.0°, -1.0°), -2.0°(-3.0°, -1.0°), HKA were -3.0°(-3.0°, -1.0°), -2.0°(-3.0°, -1.0°). There was no significant difference between the three angles before and after operation ( Z=-0.89, P=0.372; Z=1.87, P=0.061; Z=1.03, P=0.302). The average posterior tibial slope was 5°(3°, 7°). At the follow-up of one year, the KSS clinical score was 94(92, 97) and functional score was 80(70, 90) in 30 cases. During the operation, PCL was released in 1 case because of excessive tension; and lateral retinacular release was performed in 1 case because of poor patellofemoral track. Conclusion:ITKA with CR prosthesis by using the extramedullary positioning instrument on the theory of rKA alignment showed a good clinical outcome at a short follow up.

The role and value of surgeon-engineer interaction during preoperative planning of patient-specific instrumentation assisted total knee arthroplasty / 中华骨科杂志

Objective:To investigate the significance and importance of the interaction between surgeons and engineers during the preoperative planning phase of total knee arthroplasty (TKA) when utilizing patient-specific instrumentation (PSI).Methods:A retrospective review was conducted on 202 knees of PSI-assisted TKA performed on 178 patients between June 2018 and August 2022. The patients' mean age was 68.4±6.2 years, ranging from 53 to 86 years. Among the participants, there were 149 females and 29 males, 93 left knees and 109 right knees. The study involved 171 patients of osteoarthritis (193 knees) and 7 patients of rheumatoid arthritis (9 knees), with 194 knees presenting varus knees and 8 knees with valgus knees. The preoperative plan documents, from the initial engineer-designed plan to the final plan approved by the surgeon, were analyzed to assess the frequency, parameters, and reasons for adjustments made during the planning process.Results:The planning of the 202 PSI-assisted TKA was subjected to at least one round of surgeon-engineer interaction. Among the 202 TKA planning, 117 knees (57.9%) underwent modifications after discussion, with most plans (100 knees, 49.5%) being confirmed after one round of modification. Two rounds of modifications were performed on 10 knees (5.0%), and three rounds on 5 knees (2.5%). A maximum of four rounds of modifications were made on two knees (0.9%). Furthermore, in the case of the remaining 85 knees (42.1%), the surgeons promptly consented to the engineers' initial planning following the discussions. Specific adjustments were made in 106 knees (52.5%) regarding femoral parameters, 57 knees (28.2%) concerning tibial parameters, and 46 knees (22.8%) requiring adjustments to both femoral and tibial parameters. Notably, the most frequently adjusted parameter was the osteotomy thickness of the posterior femoral condyles, which was modified in 94 knees (80.3%). The reasons for adjusting femoral or tibial parameters were summarized, revealing the main factors as follows: 1) Discrepancy between the mediolateral and anteroposterior diameters of the femoral condyle; 2) Twisted deformity of the proximal tibia; 3) Severe flexion contracture deformity of the knee; 4) Collapse of the medial or lateral tibial plateau; 5) Evident anterior arch deformity of the femur.Conclusion:The interaction between surgeons and engineers plays a pivotal role in the preoperative phase of PSI-assisted TKA. Effective collaboration allows surgeons to accurately analyze the unique anatomical characteristics and pathological changes of each patient in a three-dimensional perspective, facilitating the formulation of individualized surgical plans.

Impact of the fat mass index on early functional recovery after total knee arthroplasty / 中华骨科杂志

Objective:To investigate the effect of fat mass index (FMI) on early recovery after total knee arthroplasty (TKA).Methods:Patients who underwent primary unilateral TKA in Xi'an Honghui Hospital from July 2020 to July 2021 were retrospectively analyzed. The preoperative body composition was measured by dual energy X-ray absorptiometry and the FMI was calculated. Patients were divided into normal group (male: 3.0-6.0 kg/m 2; female: 5.0-9.0 kg/m 2), overweight group (male: 6.1-9.0 kg/m 2; female: 9.1-13.0 kg/m 2), and obese group (male: >9 kg/m 2; female: >13 kg/m 2) according to level of FMI, and the operation time, blood loss, and incidence of postoperative complications were collected. Multifactorial analysis of the effect of FMI on early recovery after TKA was performed using a generalized linear model. Draw the receiver operating characteristics (ROC) curve of BMI and FMI on the predicted effect of postoperative Western Ontario and McMaster Universities (WOMAC) osteoarthritis index scores and Knee Society Score (KSS) to compare the effect of FMI with BMI on early recovery after TKA. Results:A total of 100 patients were included in the study, 24 males and 76 females, aged 65.0±8.2 years (range, 42-81 years). There were 15 cases in normal group, 55 cases in overweight group and 30 cases in obese group. All patients successfully completed the operation and were followed up for 3.15±0.72 months (range, 2.8-3.2 months). The WOMAC scores of the obese group at 2 weeks, 1 and 2 months postoperative were 34.57±3.68, 22.03±2.79, and 15.77±2.96, which were greater than those of the normal group (28.73 ±2.58, 19.07±2.71, 12.27±3.10), as well as the overweight group (30.05±4.09, 19.33±2.42, 14.84±2.42), with statistically significant differences ( P<0.05). The KSS scores of the obese group at postoperative 1 and 2 months were 68.83±5.52 and 81.17±4.49, which were lower than those of the normal group (77.33±5.63, 87.33±4.17), as well as the overweight group (72.64±5.43, 83.73 ±5.02), with statistically significant differences ( P<0.05). The WOMAC score, KSS score, and postoperative complications at 2 months postoperatively were selected as outcome indicators to plot the ROC curve, and the ROC curve for the WOMAC score at 2 months postoperatively showed an area under the curve corresponding to FMI of 0.744 (95% CI: 0.54, 0.82), which was greater than that of BMI [0.624 (95% CI: 0.51, 0.74)], and the difference was statistically significant ( Z=2.19, P=0.021). The ROC curve for the KSS score at 2 months postoperatively showed an area under the curve corresponding to FMI of 0.718 (95% CI: 0.62, 0.82), which was greater than that of BMI [0.612 (95% CI: 0.52, 0.74)], with a statistically significant difference ( Z=2.58, P=0.016). The ROC curve for postoperative complications showed an area under the curve of 0.639 (95% CI: 0.41, 0.88) for FMI and 0.605 (95% CI: 0.37, 0.84) for BMI, with no statistically significant difference ( Z=0.48, P=0.632). Conclusion:The greater the FMI the poorer the early functional recovery after initial TKA, and FMI is more valuable than BMI in predicting the early functional recovery.

Effect of patellar tilt angle after total knee arthroplasty without patellar resurfacing / 中华骨科杂志

Objective:To analyze the effect of patellar tilt angle on postoperative outcomes after total knee arthroplasty (TKA) without patella resurfacing.Methods:A total of 143 patients with end-stage knee osteoarthritis who underwent TKA without patellar replacement in the First Affiliated Hospital of Nanjing Medical University from October 2020 to October 2021 were retrospectively analyzed. There were 32 males and 111 females, aged 68.44±6.79 years (range, 52-86 years). Patients were divided into three groups according to the postoperative patellar tilt angle: tilt angle<5° was the mild tilt group (97 cases), 5°≤tilt angle<10° was the moderate tilt group (31 cases), and tilt angle≥10° was the severe tilt group (15 cases). All patients were followed up in the outpatient clinic at 3, 6 and 12 months after surgery, and knee visual analogue score (VAS), Hospital for Special Surgery (HSS) score and patella Feller score were observed and recorded to compare the postoperative knee pain and function of patients in different patella tilt groups.Results:All patients were followed up for 1.16±0.23 years (range, 1.0-2.0 years). There was no significant difference in baseline data between the groups. There were significant differences in the intra-group comparison of the VAS score before and after surgery among the three groups ( F=51.12, P<0.001; F=36.90, P<0.001; F=15.76, P<0.001). The VAS scores at 3, 6 and 12 months after operation were significantly lower than those before operation ( P<0.05). The knee VAS of the severe group was higher than that of the mild and moderate groups at 3, 6 and 12 months after surgery, and the difference was statistically significant ( P<0.05). There were statistically significant differences in knee HSS scores before and after surgery among the three groups ( F=81.12, P<0.001; F=36.05, P<0.001; F=32.93, P<0.001). The knee HSS scores at 3, 6 and 12 months after surgery were higher than those before surgery, and the difference was statistically significant ( P<0.05). The knee HSS scores of the severe tilt group at 3, 6 and 12 months after surgery were lower than those of the mild and moderate groups, and the difference was statistically significant ( P<0.05). There were statistically significant differences in the intra-group comparison of the patella Feller score before and after surgery among the three groups ( F=88.81, P<0.001; F=49.59, P<0.001; F=37.40, P<0.001). The patellar Feller score at 3, 6 and 12 months after surgery was higher than that before surgery, and the difference was statistically significant ( P<0.05). The patellar Feller score of the severe group at 3, 6 and 12 months after surgery was lower than that of the mild and moderate groups, and the difference was statistically significant ( P<0.05). Conclusion:Patellar tilt angle after TKA without patellar resurfacing will increase knee pain and limit joint function.

Physeal-sparing distal femur megaprothesis for skeletally immature patients with osteosarcoma / 中华骨科杂志

Objective:To evaluate the clinical outcome of a special physeal sparing knee prosthesis for pediatric distal femoral osteosarcoma regarding the functional outcome, retention of the growth potential of the proximal tibia, and postoperative complications.Methods:A retrospective study was conducted to review 37 pediatric patients with osteosarcoma of distal femur who were treated in a single musculuskeletal tumor center between August 2015 and January 2019. Among them, 21 were boys and 16 were girls, aged from 5 to 12 years at the time of operation, with an average age of 9.1±2.1 years and the height of 115 to 160 cm, with an average of 140±10 cm. Tumor resection of distal femur was performed and the bone defect was reconstructed by a special hinged knee prosthesis which can preserve the proximal tibial epiphyseal plate. Demographic data was recorded. Overall leg length and tibial length was assessed by full-length standing anteroposterior radiographs of bilateral lower extremity with the patella pointing anteriorly preoperativelly and postoperativelly at each follow up. And the growth potential of the affected proximal tibia was calculated by comparing with the preoperative length of tibia. Meanwhile, the functional outcome was assessed by using the Musculoskeletal Tumor Society (MSTS) system, and the postoperative complications were analysed.Results:All patients underwent the tumor resection and reconstruction operation successfully. The average operation duration was 143±41 minutes, ranging 90 to 250 minutes. The average intraoperative blood loss was 314±397 ml, ranging 30 to 2 200 ml. The patients were followed up for 24 to 64 months, averaging 42.3±12.1 months. The postoperative knee range of motion was 100-130 degrees, with an average of 115.6±7.2 degrees. The postoperative MSTS score was 23-30, with an average of 26.7±1.6. To the last follow-up, the limb length discrepancy of the lower limb was 1.3 to 10 cm, and the length of the tibia was shortened from 0 to 3.8 cm compared with the opposite side, with an average of 1.3±1.0 cm. The growth percentage of the proximal tibial epiphysis on the affected side was 30% to 100%, with an average of 70%±17%. Totally, 13 patients suffered postoperative complication, the overall incidence of complications was 35% (13/37), and prosthesis-related complications were 16% (6/37). Three patients with wound dehiscence were managed by debridement and antibiotics. Radiographs revealed femoral stem loosening in a single patient 3 years after the initial operation and then the prosthesis was converted to an adult tumor knee endoprosthesis. Two cases experienced breakage of the femoral stem at 30 and 33 months, respectively, due to an accidental injury. They received revision surgery, and a new femoral prosthesis component was replaced. One patient developed femoral stem breakage at 10 months after surgery due to fatigue fracture, which treated with revision surgery. Tumor recurrence occurred in 6 patients. Among them, tumor recurrence in soft tissue occurred in 4 patients, and treated with regional resection without further recurrence. The other 2 patients experienced tumor recurrence at the distal femoral site, and treated with resection and prosthetic revision.Conclusion:The physeal sparing pediatric knee prosthesis can preserve the growth potential of the proximal tibial epiphyseal plate with good postoperative function and low incidence of prosthesis complications. Therefore, it can be an alternativeespecially for skeletally immature patients with distal femur osteosarcoma.

Evaluation of utilizing cement-in-cement technique for endoprosthetic revision surgeries around the knee / 中华骨科杂志

Objective:To investigate the clinical efficacy of cement-in-cement (CiC) technique for endoprosthetic revision surgeries of noninfectious causes around the knee.Methods:All of 128 patients who had received cement-in-cement technique for endoprosthetic revision from February 2002 to August 2020 including 71 males and 57 females, whose mean age was 33.5±15.4 years (range, 8-77 years). 128 patients included 73 cases of osteosarcoma, 38 cases of giant cell tumors, 8 cases of undifferentiated sarcoma, 4 cases of chondrosarcoma, 2 cases of Ewing sarcoma, 2 cases of fibrosarcoma and 1 case of synovial sarcoma, with 105 cases in distal femur and 23 cases in proximal tibia. The failure mode classification included 64 cases of aseptic loosening, 47 cases of structure failure and 17 cases of tumor progression. 16 out of the 19 endoprosthese failure after the first cement-in-cement procedure received a second cement-in-cement procedure. The survival of revised prostheses, duration of the operation, the amount of blood loss, epidemiological data, complications and limb function were enrolled and statistical analyzed.Results:The mean follow-up from CiC revision was 127±33 months (range, 6-326 months). There were 25 (19.5%) complications for the first CiC procedure and 19 (14.8%) of the 25 complications lead to the protheses failure including 5 (3.9%) structure failure, 6 (4.7%) aseptic loosening, 2 (1.6%) tumor recurrence and 6 (4.7%) infection. The other 6 cases included 5 poor superficial wound healing and 1 patellar ligament rupture. All were recovered after debridement and tendon repair. The cumulative survival rates of first CiC procedure were 85.0%, 76.6% and 70.7% at 5, 10 and 15 years, respectively. Limb salvage rate was 97.7%. Sixteen of the 19 cases received a second CiC revision. The mean operative time (206±51 min vs. 258±41 min, t=3.18, P=0.399), blood loss (596±217.99 ml vs. 621±245.84 ml, t=0.30, P=0.926) and the median MSTS 93 score (26.38±2.47 vs. 25.06±2.11, t=1.61, P=0.376) of the first and second CiC procedure for the 16 cases were similar. Conclusion:CiC technique is a repeatable, conservative and viable option for endoprosthetic revision surgeries of noninfectious causes around the knee, with acceptable prosthetic survival rate, complication rate and limb function.

Management of periprosthetic femur fracture after total knee arthroplasty / 中华骨科杂志

Periprosthetic fracture of femur is the most common postoperative complication after total knee arthroplasty (TKA). Risk factors for periprosthetic fractures include female sex, osteoporosis/osteopenia, rheumatoid arthritis, osteoarthritis, neuromuscular disease, cognitive disorder, chronic use of corticosteroids, obesity, advanced age, infection, osteolysis around the prosthesis, knee joint ankyloses, notching of the anterior femoral cortex, etc. According to epidemiological research, the incidence of femoral periprosthetic fractures following TKA ranges from 0.3% to 2.5%. Lewis and Rorabeck classifications, the most commonly used classification of periprosthetic fractures of the femur, introduce the concept of prosthesis loosening and emphasize the ecessity of revision surgery. Other classifications include Su typing, Universal Typing System, and Rhee typing, the latest of which is the Kim typing proposed in 2022. Treatment strategies for periprosthetic femoral fractures after TKA include nonsurgical treatment, external fixation techniques, single-plate fixation, double-plate fixation, intramedullary nail fixation, and revision TKA and distal femur replacement. The purpose of this paper is to better guide the prevention and treatment of periprosthetic fractures after TKA by searching and analyzing relevant literature on periprosthetic fractures after TKA.

Coxiella burnetii in periprosthetic joint infection: a case and systematic review / 中华骨科杂志

One case of periprosthetic infection after artificial joint replacement caused by Coxiella burnetii was reported. The patient was admitted to hospital due to joint pain and sinus formation after artificial knee replacement. Through medical history, physical examination, imaging examination and gene detection, it was confirmed that the infection around the prosthesis was caused by Coxiella burnetii. The patient was treated with two-stage revision surgery combined with sensitive antibiotics. Through literature review, a total of 9 cases of Coxiella burnetii infection after artificial joint replacement were reported, including 6 cases of hip joint and 3 cases of knee joint; 4 cases had clear pathogen exposure history; only one case was found protheses loosening on imaging; 7 cases with positive IgG antibody against Coxiella burnetii; 7 cases were positive for gene detection; 8 cases were negative in etiological examination, and 1 case was not cultured. All patients were treated with doxycycline and hydroxychloroquine. The serological index of 1 case without Q fever symptom turned negative after treatment. 1 case with multiple system organ dysfunction relieved symptoms after treatment, and serological antibody indicators and nuclear medicine results turned negative. All 7 patients were cured after secondary revision surgery. Coxiella burnetii infection after total joint arthroplasty is rare and lacks typical imaging manifestations and clinical features. The diagnosis of Coxiella burnetii infection after total joint arthroplasty mainly depends on gene detection and serological detection. Two-stage revision surgery combined with sufficient and long-term sensitive antibiotics is the main method of treatment.

Perioperative multimodal analgesia of total knee arthroplasty: current practices / 中华骨科杂志

Pain management plays an essential role in the improvement of clinical outcome and patient satisfaction of total knee arthroplasty (TKA). With the emergence of preemptive analgesia, preventive analgesia and other analgesia concepts, the whole process of perioperative pain management and multimodal analgesia during perioperative period has become the most important principle of pain management for TKA. The use of classical analgesia drugs like acetaminophen, non-steroidal anti-inflammatory drugs (NSAIDs) and opioid drugs still have important position. At the same time, various kinds of regional block analgesia represented by femoral nerve block, adductor canal block, peri-articular multimodal drug mixture injection, etc., have precise analgesic effects and less adverse reactions. Their role in the multimodal analgesia system after TKA is increasingly apparent.

The learning curve of MAKO-assisted total knee arthroplasty / 中华骨科杂志

Objective:To explore the learning curve of MAKO-assisted total knee arthroplasty.Methods:From May 2021 to September 2022, 136 patients were conducted MAKO-assisted total knee arthroplasty in the PLA General Hospital, including 37 males and 99 females, 65.53±7.01 years old (range 54-80 years). All cases were patients with unilateral knee osteoarthritis. The operations were performed by three surgeons, respectively. Sixty-one cases were performed by surgeon 1, 47 cases were performed by surgeon 2, and 28 cases were performed by surgeon 3. Record the time of each step during the operation, and measure the limb alignment in X-ray. The statistical difference between the two groups was compared by t test by SPSS. The cumulative sum control chart (CUSUM) learning curve was modeled by curve fitting and R2 was used to testify the goodness. Results:The total operation time of the three surgeons was 114.3±25.1 min, 109.8±10.9 min, and 118.6±15.1 min, respectively. The time of each step in the first 10 cases and the last 10 cases of operator 1-3 was counted. The osteotomy time of surgeons 1, 2 and 3 in the final 10 cases was less than that in the initial 10 cases (surgeon 1: 13.5 ± 3.41 min vs. 8.0±1.58 min, t=4.30, P=0.001; surgeon 2: 13.7±3.02 min vs. 8.0± 2.58 min, t=4.77, P=0.001; surgeon 3: 15.3±3.97 min vs. 11.0±2.38 min, t=2.87, P=0.010), and the difference was statistically significant. The CUSUM of osteotomy was calculated and the curve was fitted. The highest point of the curve of the three surgeons was in the 16th, 18th and 12th patients, respectively, and the time of osteotomy continued to decline after passing the peak. No statistical differences were found in surgery time for the remaining steps. Comparing the lower alignment angles of intraoperative planning and postoperative X-ray films, the overall difference was greater than 1 degree. The difference was 1.41°±1.32° for operator 1, 1.34°±1.22° for operator 2, and 1.04°±0.88° for operator 3. The percentages of fully accurate implant size planning were 85.2%(52/61), 76.7%(36/47), and 85.7%(24/28), respectively. Conclusion:For MAKO-assisted total knee arthroplasty, the operator can decrease the operation time by practice, which is mainly reflected in the shortening of the osteotomy time. The learning curve threshold is around in the 15th case. The increase in the number of surgeries did not bring about changes in the accuracy of lower extremity alignment.

Analysis of factors affecting the change in relative patellar height after robotic-assisted primary total knee arthroplasty / 中华骨科杂志

Objective:To analyze the factors affecting the relative height change of the patella after primary robotic-assisted total knee arthroplasty (R-TKA).Methods:The data of 97 patients with osteoarthritis of the knee treated with R-TKA admitted from June 2021 to March 2022 were retrospectively analyzed, including 15 males and 82 females, aged 70.0±5.4 years (range, 58-80 years). The bone resection parameters of the robotic system were recorded intraoperatively, including the bone resection amount of the medial and lateral distal femur, medial and lateral posterior femoral condyle and medial and lateral tibial plateau. The Blackburne-Peel index (BPI) and Caton-Deschamps index (CDI) were used to measure the preoperative and postoperative relative patellar height on lateral radiographs, as well as the posterior tibial slope (PTS) and the change in patellar ligament length before and after surgery. The relationship between the change in relative patellar height and the variables of interest was analyzed using partial correlation and multiple linear regression.Results:The mean postoperative CDI was lower than preoperatively (0.79±0.15 vs. 0.91±0.13, t=9.69, P<0.001), and the percentage of patients with postoperative CDI<0.6 was higher than preoperatively (9.3% vs. 0; χ 2=12.92, P<0.001); the differences in mean postoperative BPI and percentage of patients with postoperative BPI<0.45 were not statistically significant compared to preoperatively (0.69±0.13 vs. 0.71±0.17, t=1.35, P=0.182; 11.3% vs. 17.5%, χ 2=1.50, P=0.220). The mean patellar ligament length on the first postoperative day was 2.29 mm shorter than preoperatively, there was a statistically significant difference ( t=5.90, P<0.001). Partial correlation analysis showed that the amount of patellar ligament length change was positively correlated with the amount of BPI and CDI change ( r=0.84, P<0.001; r=0.70, P<0.001), and the amount of PTS change and the mean distal femoral bone resection were negatively correlated with the amount of BPI ( r= -0.41, P<0.001; r=-0.32, P=0.002) and CDI ( r=-0.23, P=0.029; r=-0.25, P=0.017) change. In contrast, the amount of posterior femoral condyle bone resection and tibial plateau bone resection did not correlate with the change of BPI and CDI. Multiple linear regression analysis showed that the amount of patellar ligament length change, PTS change and the distal femoral bone resection were factors influencing the change of BPI ( β=0.03, P<0.001; β=-0.01, P<0.001; β=-0.02, P=0.021) and CDI ( β=0.02, P<0.001; β=-0.01, P=0.001; β=-0.02, P=0.008). Conclusion:Amount of patellar ligament length change, PTS change and the distal femoral bone resection are factors affecting the BPI. In order to obtain a better relative patellar height in the primary R-TKA, attention should be paid to the adjustment of the distal femoral bone resection and PTS, while taking the necessary measures to reduce the postoperative patellar ligament length changes.