Journal of Joint Surgery and Research最新文献

{"title":"Impact of femoral component flexion on implant sizing in unicompartmental knee arthroplasty: A three-dimensional computed tomography-based simulation study","authors":"Kazu Matsumoto,&nbsp;Daichi Ishimaru,&nbsp;Kazuki Sohmiya,&nbsp;Nobuo Terabayashi","doi":"10.1016/j.jjoisr.2025.09.006","DOIUrl":"10.1016/j.jjoisr.2025.09.006","url":null,"abstract":"<div><h3>Purpose</h3><div>Accurate femoral component sizing is essential for successful unicompartmental knee arthroplasty (UKA). This study aimed to investigate the effect of sagittal alignment on femoral component sizing using three-dimensional (3D) simulation and to validate findings with post-operative measurements.</div></div><div><h3>Methods</h3><div>Thirty-two knees from 29 patients undergoing UKA were analyzed using 3D computed tomography (CT)-based planning with ZedKnee software. Femoral components were virtually implanted at seven sagittal alignments (−10°, −5°, 0°, 5°, 10°, 15°, and 20°), and changes in component size, bone resection surface area, and length were evaluated. Post-operative sagittal alignment was measured relative to the femoral mechanical axis using 3D CT. Repeated measures ANOVA with Bonferroni correction was performed.</div></div><div><h3>Results</h3><div>Increasing flexion led to reduced component size, while extension increased size. Deviations of ±10° from neutral resulted in a one-size change. Bone resection surface area and length decreased significantly with flexion (<em>p</em> ​&lt; ​0.05), correlating with downsizing. Post-operative measurements showed a mean femoral component flexion of 1.4 ​± ​3.6° (range −3.9° to 9.7°), with 87.5% implanted within ±5° of neutral.</div></div><div><h3>Conclusions</h3><div>Excessive femoral component flexion systematically reduces implant size by decreasing bone resection. Maintaining sagittal alignment within ±5° of neutral is crucial for accurate sizing. These findings emphasize the importance of precise pre-operative planning and intra-operative technique to optimize UKA outcomes.</div></div>","PeriodicalId":100795,"journal":{"name":"Journal of Joint Surgery and Research","volume":"3 4","pages":"Pages 233-238"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145362308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Early clinical outcomes of a newly designed Zweymüller cementless stem in total hip arthroplasty: a retrospective cohort study","authors":"Hideki Ueyama,&nbsp;Ryo Sugama,&nbsp;Yukihide Minoda,&nbsp;Sho Masuda,&nbsp;Yohei Ohyama,&nbsp;Ryosuke Kirihigashi,&nbsp;Yuichi Miura,&nbsp;Hidetomi Terai","doi":"10.1016/j.jjoisr.2025.09.001","DOIUrl":"10.1016/j.jjoisr.2025.09.001","url":null,"abstract":"<div><h3>Purpose</h3><div>The Promontory stem, a newly developed Zweymüller cementless femoral stem with a proximal fixation-enhancing fin, was introduced in Japan in 2022. This study aimed to evaluate its early clinical and radiological outcomes.</div></div><div><h3>Methods</h3><div>This retrospective cohort study included 56 patients who underwent primary total hip arthroplasty using the Promontory stem between August 2022 and October 2023. Clinical scores (JOA, EQ-VAS, HOOS-JR, FJS-12) and radiographic findings (stem alignment, stress shielding, radiolucent lines, cortical hypertrophy) were assessed at a mean follow-up of 22.8 months. Multivariate logistic regression was used to identify predictors of stress shielding around the stem.</div></div><div><h3>Results</h3><div>The mean patient age was 66.0 years and 71.4% were female. JOA scores improved significantly from pre-to post-operative time points in all domains; the total score increased from 42.9 to 82.3 ​at 2 years (<em>p</em> ​&lt; ​0.001). Mean EQ-VAS, HOOS-JR, and FJS-12 scores at final follow-up averaged 77.3 ​± ​17.6, 79.8 ​± ​15.7, and 63.5 ​± ​25.6, respectively. Radiologically, stress shielding was observed in 66.1%, with 17.9% having grade 2 or higher. Radiolucent lines were noted in 69.6% and cortical hypertrophy in 17.9%. No cases of aseptic loosening occurred. Complications included stem subsidence (3.6%), dislocation (3.6%), and periprosthetic fracture (1.8%). The 2 year implant survival rate was 98.2%. Multivariate logistic regression identified older age, female sex, and pre-operative lower bone mineral density of femoral neck as predictors of stress shielding.</div></div><div><h3>Conclusions</h3><div>The Promontory stem showed favorable early outcomes with no major complications and high survivorship, despite frequent stress shielding and proximal radiolucent lines.</div></div>","PeriodicalId":100795,"journal":{"name":"Journal of Joint Surgery and Research","volume":"3 4","pages":"Pages 194-200"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145096193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Early post-operative in vivo kinematics after total ankle arthroplasty using a total talar prosthesis: Three-dimensional analysis using the iterative closest point algorithm","authors":"Hiroaki Kurokawa ,&nbsp;Yasuhito Tanaka ,&nbsp;Shinichi Kosugi ,&nbsp;Rea Ikeda ,&nbsp;Tatsuya Fukuda ,&nbsp;Norihiro Tsujimoto ,&nbsp;Yoshiyuki Kamatani ,&nbsp;Yinghao Li ,&nbsp;Nan Mei ,&nbsp;Yuki Ueno ,&nbsp;Takuma Miyamoto ,&nbsp;Kiyonori Tomiwa ,&nbsp;Akira Taniguchi ,&nbsp;Shinichi Nakagawa ,&nbsp;Hiroshi Takemura ,&nbsp;Yoshinori Takakura","doi":"10.1016/j.jjoisr.2025.09.003","DOIUrl":"10.1016/j.jjoisr.2025.09.003","url":null,"abstract":"<div><h3>Purpose</h3><div>The <em>in vivo</em> kinematics after combined total ankle arthroplasty (TAA) remains unknown. This study evaluated and compared the three-dimensional kinematics of the talar component between standard TAA, using the talar component where only the surface of the talar dome was replaced, and combined TAA, using the iterative closest point algorithm and computed tomography (CT).</div></div><div><h3>Methods</h3><div>The combined TAA and standard TAA groups comprised 17 and 9 ankles, respectively. CT was performed with patients in active dorsiflexed and plantarflexed ankle positions at least 3 months post-operatively.</div></div><div><h3>Results</h3><div>From non-weight-bearing dorsiflexion to plantarflexion, a significant medial translation of the total talar prosthesis was observed in the combined TAA group compared with the standard TAA group. Rotation of the x-axis (inversion) and translation of the z-axis (lateral translation) were negatively correlated.</div></div><div><h3>Conclusions</h3><div>Combined TAA results in greater inversion of the ankle joint during plantarflexion than standard TAA.</div></div>","PeriodicalId":100795,"journal":{"name":"Journal of Joint Surgery and Research","volume":"3 4","pages":"Pages 207-213"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Early closure of initial gaps in the bone–tray interface of modern cementless total knee arthroplasty: A retrospective cohort study","authors":"Yoshinori Mikashima ,&nbsp;Hitoshi Imamura ,&nbsp;Koichiro Yano ,&nbsp;Katsunori Ikari ,&nbsp;Hiroshi Takagi ,&nbsp;Ken Okazaki","doi":"10.1016/j.jjoisr.2025.06.006","DOIUrl":"10.1016/j.jjoisr.2025.06.006","url":null,"abstract":"<div><h3>Purpose</h3><div>Initial gaps in the tibial bone–tray interface may sometimes occur due to insufficient impaction, especially on hard tibial bone. The purpose of this study was to investigate the frequency of occurrence, characteristics, and natural history of initial gaps between the tibial bone–tray interface during surgery in a modern cementless total knee arthroplasty (TKA).</div></div><div><h3>Methods</h3><div>A retrospective review of a consecutive series of 273 cementless posterior stabilized mobile-bearing TKAs (Attune; DePuy Synthes, Warsaw, IN, USA) was performed. The incidence of gaps between the tibial bone and tibial tray that remained open during surgery was reviewed immediately after surgery and at 1 week, 1, 2, 4, and, 6 months, and 1 year post-operatively. The 273 TKAs were divided into two groups: TKAs with initial gaps (Group G) and those without gaps (Group N).</div></div><div><h3>Results</h3><div>Initial gaps appeared in 26 of the 273 TKAs (9.5%) on radiographs immediately after surgery. Four of 26 TKAs (15%) showed initial gaps that naturally disappeared due to weight-bearing at 1 week post-operatively, 16 of 26 TKAs (62%) within 1 month post-operatively, 20 of 26 TKAs (77%) within 2 months post-operatively, and all 26 TKAs (100%) within 4 months post-operatively. Group G included significantly younger patients (<em>p</em> ​&lt; ​0.01) with a higher body mass index (<em>p</em> ​&lt; ​0.01) than Group N. No patients required revision surgery.</div></div><div><h3>Conclusion</h3><div>The majority of initial gaps at the tibial bone–tray interface were resolved early during follow-up in a modern, cementless, posterior stabilized, mobile-bearing TKA.</div></div>","PeriodicalId":100795,"journal":{"name":"Journal of Joint Surgery and Research","volume":"3 3","pages":"Pages 145-150"},"PeriodicalIF":0.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144722880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Proximal tibia bone mineral density correlates more closely with hip density in men with knee osteoarthritis","authors":"Junya Itou ,&nbsp;Ayano Kuwasawa ,&nbsp;Kotaro Nihei ,&nbsp;Ken Okazaki","doi":"10.1016/j.jjoisr.2025.06.001","DOIUrl":"10.1016/j.jjoisr.2025.06.001","url":null,"abstract":"<div><h3>Purpose</h3><div>Achieving biological fixation of the often loosened tibia is increasingly important for total knee arthroplasty (TKA), with one key factor being the bone density of the proximal tibia. This study examined whether hip bone mineral density (BMD), the most common diagnostic tool for osteoporosis, can estimate tibial BMD in both sexes.</div></div><div><h3>Methods</h3><div>This retrospective study included patients who underwent primary TKA with hip and tibial BMD measurement. Tibial BMD was measured 10 ​mm distal to the lateral tibial articular surface, separately for the medial (BMD_m) and lateral (BMD_l) sides. Additionally, the association between BMD and lower limb alignment was evaluated.</div></div><div><h3>Results</h3><div>In total, 1012 knees were included (79.3% in women). The mean patient age at surgery was 73.3 ​± ​7.5 years. The mean total hip BMD for women and men was 0.79 ​± ​0.13 ​g/cm² and 0.95 ​± ​0.16 ​g/cm², respectively. The mean BMD_m and BMD_l was, respectively, 0.75 ​± ​0.16 ​g/cm² and 0.63 ​± ​0.13 ​g/cm² in women and 0.92 ​± ​0.18 ​g/cm² and 0.89 ​± ​0.18 ​g/cm² in men. Both BMD_m and BMD_l showed a moderate correlation with hip BMD (<em>r</em> ​= ​0.67 and 0.66, respectively) in men. In women, BMD_m showed a weak correlation (<em>r</em> ​= ​0.47). Regarding lower limb alignment, BMD_m was significantly higher in varus alignment than in neutral or valgus alignment. BMD_l did not change with lower limb alignment.</div></div><div><h3>Conclusions</h3><div>BMD_m and BMD_l were moderately correlated with hip BMD in men, while BMD_m showed a low correlation in women.</div></div>","PeriodicalId":100795,"journal":{"name":"Journal of Joint Surgery and Research","volume":"3 3","pages":"Pages 121-127"},"PeriodicalIF":0.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144335816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Porous tantalum versus titanium-coated acetabular cups in total hip arthroplasty: Midterm radiological evidence of supralateral bone defect filling without grafting","authors":"Takuhei Kozaki ,&nbsp;Satoru Yamazaki ,&nbsp;Kimihide Murakami ,&nbsp;Shigeki Sando ,&nbsp;Koji Hashimoto ,&nbsp;Akihiro Hoshino ,&nbsp;Yuki Kuboi ,&nbsp;Daisuke Nishiyama ,&nbsp;Daisuke Fukui ,&nbsp;Mamoru Kawakami","doi":"10.1016/j.jjoisr.2025.06.002","DOIUrl":"10.1016/j.jjoisr.2025.06.002","url":null,"abstract":"<div><h3>Purpose</h3><div>Like bone formation, porous tantalum (Ta) for total hip arthroplasty (THA) improves both initial stability and secondary biological fixation compared with porous titanium (Ti). The authors have occasionally observed new bone formation filling the cavity between the acetabular cup and acetabular bone in the supralateral part over time. This study aimed to investigate whether an improvement in bone coverage of the Ta cup was observed over time compared with that of the Ti cup.</div></div><div><h3>Methods</h3><div>This study included 223 patients (223 hips) with hip osteoarthritis who underwent primary THA using either a Ta or Ti cup. Host bone coverage of the acetabular cup was examined on radiographs using the cup center-edge (CE) angle and bone coverage index (BCI). Radiologically measured cup inclination (RI) was also measured.</div></div><div><h3>Results</h3><div>At 5 years, the mean cup CE angle was 35.3 ​± ​7.5° for Ti and 37.4 ​± ​7.1° for TA (<em>p</em> ​= ​0.036), and the BCI was 90.8 ​± ​5.4% and 92.6 ​± ​6.6, respectively (<em>p</em> ​= ​0.033). The improvement rates from 2 years to 5 years and from baseline to 5 years were statistically significantly greater in the Ta group than in the Ti group. In the multiple regression analysis, BCI at baseline (<em>p</em> ​&lt; ​0.0001), Ta (<em>p</em> ​= ​0.018), and RI (<em>p</em> ​= ​0.018) were significant predictors of BCI improvement 2–5 years later.</div></div><div><h3>Conclusions</h3><div>Filling the bone deficit in the lateral part of the cup without a bone graft over time had an advantage in the Ta cup over the Ti cup, which may enhance long-term survival. Additionally, RI and BCI were identified as important factors.</div></div>","PeriodicalId":100795,"journal":{"name":"Journal of Joint Surgery and Research","volume":"3 3","pages":"Pages 138-144"},"PeriodicalIF":0.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144596657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tranexamic acid in total hip arthroplasty: Nationwide evidence for reducing blood transfusions and post-operative complications","authors":"Hidetatsu Tanaka ,&nbsp;Kunio Tarasawa ,&nbsp;Yu Mori ,&nbsp;Kazuyoshi Baba ,&nbsp;Ryuichi Kanabuchi ,&nbsp;Yasuaki Kuriyama ,&nbsp;Hiroaki Kurishima ,&nbsp;Hideki Fukuchi ,&nbsp;Hiroki Kawamata ,&nbsp;Kiyohide Fushimi ,&nbsp;Toshimi Aizawa ,&nbsp;Kenji Fujimori","doi":"10.1016/j.jjoisr.2025.06.004","DOIUrl":"10.1016/j.jjoisr.2025.06.004","url":null,"abstract":"<div><h3>Purpose</h3><div>Total hip arthroplasty (THA) is an effective treatment for hip degenerative diseases; however, peri-operative blood loss often necessitates blood transfusion. Tranexamic acid (TXA) is widely used to reduce bleeding, although limited real-world evidence exists from Japanese populations. This study assessed the association between peri-operative TXA use and transfusion requirements and complications using nationwide data.</div></div><div><h3>Methods</h3><div>THA cases in the Japanese Diagnosis Procedure Combination (DPC) database from December 2011 to March 2023 were retrospectively analyzed. Patients undergoing primary THA for osteoarthritis, osteonecrosis, or rheumatoid arthritis were included. One-to-one propensity score (PS) matching was performed between patients who received TXA and those who did not. Logistic regression was used to evaluate outcomes including allogenic and autologous transfusion rate, infection, deep vein thrombosis (DVT), pulmonary embolism (PE), and death. A subgroup analysis of TXA dosage (≥2000 ​mg <em>vs.</em> &lt;2000 ​mg) was performed.</div></div><div><h3>Results</h3><div>After PS matching, 134,653 patients were included in each group. TXA use significantly reduced allogeneic transfusion on post-operative Day 0 [odds ratio (OR) 0478], Day 1 (OR 0.377), and Day 2 (OR 0.339). Similarly, TXA use significantly reduced autologous transfusion rates on Day 0 (OR 0.555), Day 1 (OR 0.486), and Day 2 (OR 0.533). Higher TXA doses (≥2000 ​mg) further reduced Day 0 allogeneic and autologous transfusions, but increased autologous transfusion risk on Day 1. While no statistically significant differences were found in infection, PE, or death, TXA was associated with a slightly higher DVT risk.</div></div><div><h3>Conclusions</h3><div>Peri-operative TXA use in THA reduced transfusion needs without increasing PE or mortality risks, although careful monitoring for DVT is warranted. Future studies should clarify optimal dosing strategies tailored to Japanese populations.</div></div>","PeriodicalId":100795,"journal":{"name":"Journal of Joint Surgery and Research","volume":"3 3","pages":"Pages 132-137"},"PeriodicalIF":0.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144517917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Is selective hospitalist–orthopedic surgeon co-management based on the Charlson comorbidity index useful in peri-operative care of total hip arthroplasty?","authors":"Kazuhiko Sonoda ,&nbsp;Yusuke Kubo ,&nbsp;Sanshiro Inoue ,&nbsp;Toshihiko Hara","doi":"10.1016/j.jjoisr.2025.06.003","DOIUrl":"10.1016/j.jjoisr.2025.06.003","url":null,"abstract":"<div><h3>Purpose</h3><div>Total hip arthroplasty (THA) is an effective treatment for hip diseases, but peri-operative management of patients with multiple comorbidities is challenging due to an increased risk of medical complications. Hospitalist–orthopedic surgeon co-management (HOC) has been reported to improve peri-operative care, but its effectiveness and impact on healthcare resources remain uncertain. This prospective, single-center study evaluated the utility of selective HOC based on the Charlson comorbidity index (CCI) in THA peri-operative management.</div></div><div><h3>Methods</h3><div>This study included 90 consecutive cases with primary THA by a single orthopedic surgeon. Based on CCI, patients were divided into an HOC group (CCI score ≥2) and non-HOC group (CCI score &lt;2). The HOC group received peri-operative care from a hospitalist and orthopedic surgeon, while non-HOC group was managed by an orthopedic surgeon alone. Medical and surgery-related complications, hospital length of stay, 30-day mortality, and costs were evaluated.</div></div><div><h3>Results</h3><div>There were 17 cases (19%) in the HOC group and 73 (81%) in non-HOC group. The mean CCI score was 3.1 ​± ​1.3 in the HOC group and 0.4 ​± ​0.5 in the non-HOC group. Medical complications were more frequent in the HOC group (35% <em>vs.</em> 4%), while surgery-related complications were comparable. No statistically significant difference was observed in length of stay, 30-day mortality, and costs.</div></div><div><h3>Conclusions</h3><div>Selective indication for HOC based on CCI effectively identified high-risk patients, enabling timely intervention for medical complications without prolonging hospital stay. This strategy may mitigate peri-operative medical risks while optimizing resource use.</div></div>","PeriodicalId":100795,"journal":{"name":"Journal of Joint Surgery and Research","volume":"3 3","pages":"Pages 128-131"},"PeriodicalIF":0.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144517916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Appropriate flexion gap evaluation for fine-tuning of medial stabilizing technique in JOURNEY II bicruciate stabilized total knee arthroplasty","authors":"Yukio Akasaki,&nbsp;Satoshi Hamai,&nbsp;Shinya Kawahara,&nbsp;Ichiro Kurakazu,&nbsp;Kenji Kitamura,&nbsp;Yasuharu Nakashima","doi":"10.1016/j.jjoisr.2025.07.004","DOIUrl":"10.1016/j.jjoisr.2025.07.004","url":null,"abstract":"<div><h3>Purpose</h3><div>Successful total knee arthroplasty (TKA) relies on proper ligament balancing with a focus on medial stability. Intra-operative evaluation of the medial flexion gap must account for the relative femur–tibia positioning after implant placement. This study investigated whether intra-operative fine-tuning of the medial gap, enabled by a simple, reproducible spacer block for precise flexion gap measurement, could achieve consistent medial gap matching in both extension and flexion.</div></div><div><h3>Methods</h3><div>Forty-seven patients (9 men, 38 women) with knee osteoarthritis underwent JOURNEY II bicruciate stabilized TKA. A spacer block simulating post-cam engagement was designed to accurately assess the medial flexion gap. Intra-operative fine-tuning of the medial flexion gap was performed using spacer blocks and a stepless femoral cutting guide. Gaps were measured during the component trial using a tension device and at 1 year post-operatively via stress radiographs.</div></div><div><h3>Results</h3><div>Initially, 29% of knees exhibited a flexion–extension gap difference ≥2 ​mm after posterior cruciate ligament resection and tibial osteotomy. Spacer block fine-tuning reduced this to 8% and this improvement persisted at 1 year. At 4 years follow-up, Knee Society Scores were favorable, with significant gains in extension and flexion angles.</div></div><div><h3>Conclusion</h3><div>The developed spacer block technique, which replicates the post-cam engaging position, provided consistent and accurate flexion gap measurements and reduced flexion–extension discrepancies. This approach enhanced knee stability and patient outcome post-TKA.</div></div>","PeriodicalId":100795,"journal":{"name":"Journal of Joint Surgery and Research","volume":"3 3","pages":"Pages 170-175"},"PeriodicalIF":0.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144852844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Worsening pain patterns and chronic post-surgical pain following total hip arthroplasty: A 6-month retrospective cohort study","authors":"Yusuke Suzuki ,&nbsp;So Tanaka ,&nbsp;Ryota Imai ,&nbsp;Takeshi Chiba","doi":"10.1016/j.jjoisr.2025.07.001","DOIUrl":"10.1016/j.jjoisr.2025.07.001","url":null,"abstract":"<div><h3>Purpose</h3><div>The aim of this study was to investigate chronic post-surgical pain (CPSP) in patients in the 6 months after total hip arthroplasty (THA), focusing on its prevalence, contributing factors, and duration.</div></div><div><h3>Methods</h3><div>Study subjects were 257 women who underwent THA at a single hospital. The following measures were evaluated pre-operatively and at 1, 2, and 6 months post-operatively: motion pain measured using a visual analog scale (VAS); central sensitization syndrome; pain catastrophizing; fear of movement; self-efficacy; anxiety; and depression scale. CPSP was defined as VAS ≥30 ​mm at 6 months post-operatively, and patients were dichotomized into CPSP and non-CPSP groups. The results were compared in a two-way analysis of variance (ANOVA) with presence and timing of CPSP as factors.</div></div><div><h3>Results</h3><div>The incidence of CPSP was 5.1%, and the CPSP group was significantly older than the non-CPSP group. ANOVA showed that the VAS was significantly higher in the CPSP group at 1, 2, and 6 months post-operatively compared with the non-CPSP group. Furthermore, the VAS of the CPSP group was significantly higher, and it was worse at 6 months than at 1 month post-operatively.</div></div><div><h3>Conclusions</h3><div>In this Japanese cohort, the incidence of CPSP after THA was lower than that reported in international studies. Although initial pain relief was observed, some patients experienced worsening pain from around 1 month post-operatively. This finding suggests the importance of timely interventions during this subacute period to help prevent the progression of CPSP.</div></div>","PeriodicalId":100795,"journal":{"name":"Journal of Joint Surgery and Research","volume":"3 3","pages":"Pages 151-158"},"PeriodicalIF":0.0,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144724387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}