Finite element analysis of mechanical stress in a cementless tapered-wedge short stem in the varus position.

BACKGROUND: In recent years, the use of tapered-wedge short stems has increased due to their ability to preserve bones and tendons. Surgical techniques occasionally result in a varus position of the stem, which is particularly pronounced in short stems. Although the varus position is not clinically problematic, there are reports of an increased incidence of stress shielding and cortical hypertrophy. Thus, we evaluated and examined the acceptable range of varus angles using finite element analysis. METHODS: Patients diagnosed with osteoarthritis of the hip joint who had undergone arthroplasty were selected and classified into three types [champagne-flute (type A), intermediate (type B), and stovepipe (type C)]. Finite element analysis was performed using Mechanical Finder. The model was created using a Taperloc microplasty stem with the varus angle increased by 1° from 0° to 5° from the bone axis and classified into seven zones based on Gruen's zone classification under loading conditions in a one-leg standing position. The volume of interest was set, the mean equivalent stress for each zone was calculated. RESULTS: A significant decrease in stress was observed in zone 2, and increased stress was observed in zones 3 and 4, suggesting the emergence of a distal periosteal reaction, similar to the results of previous studies. In zone 2, there was a significant decrease in stress in all groups at a varus angle ≥ 3°. In zone 3, stress increased from ≥ 3° in type B and ≥ 4° in type C. In zone 4, there was a significant increase in stress at varus angles of ≥ 2° in types A and B and at ≥ 3° in type C. CONCLUSION: In zone 2, the varus angle at which stress shielding above Engh classification grade 3 may appear is expected to be ≥ 3°. Distal cortical hypertrophy may appear in zones 3 and 4; the narrower the medullary cavity shape, the smaller the allowable angle of internal recession, and the wider the medullary cavity shape, the wider the allowable range. Long-term follow-up is required in patients with varus angles > 3°.

Recent advances in unlinked total elbow arthroplasty in Japan.

Background: Total elbow arthroplasty (TEA) is a valuable therapeutic approach for improving function and relieving pain in severely deformed elbow joints. However, TEA is associated with a high incidence of complications. In Japan, the use of unlinked TEA has a long history, with the development of the Kudo prosthesis marking a significant milestone. Subsequently, various unlinked implant designs have been developed. Although favorable long-term clinical results have been reported, complications remain a concern. To further improve the outcome of unlinked TEA, attempts have been made in recent years to develop various surgical approaches and intraoperative support devices. This review focuses on the clinical outcomes and recent advances in unlinked TEA in Japan. Methods: A comprehensive review of clinical results and advancements in unlinked TEA in Japan was conducted. The analysis included trends in the number of TEA, medium-term and long-term results for unlinked TEA, surgical approaches, or preoperative planning techniques. Results: Several implant designs have been developed in Japan. Clinical studies have reported satisfactory long-term outcomes with these implants, but complications, such as infection, fractures, and dislocation, have been observed. In order to enhance the outcomes of unlinked TEA, various triceps-on approaches have been developed as alternatives to the triceps-detaching approach, which compromises the continuity between the triceps tendon and ulna, leading to inevitable complications related to the triceps tendon. Preservation or repair of the surrounding soft tissues is considered critical for preventing postoperative instability due to the absence of a radial head in the current unlinked TEA design. Computed tomography-based 3-dimensional preoperative planning has been pioneered in Japan, demonstrating its effectiveness in predicting implant size and achieving appropriate implant placement. Additionally, augmented reality-assisted surgery is being explored to accurately translate preoperative planning into the surgical procedure. Conclusion: Unlinked TEA for inflammatory arthritis has exhibited promising long-term results in Japan, with ongoing efforts to improve surgical techniques and preoperative planning. Further advancements are anticipated to prevent complications such as dislocation and peri-implant fractures.

Residual Deformity of the Trochlea After Non-displaced Supracondylar Fracture in a Child: A Case Report.

Residual deformity of the trochlea after fractures of the distal end of the humerus in children is well known and is referred to as fishtail deformity. Despite numerous reports on this entity, the reason for various types of fractures with the same results remains unknown. Fishtail deformities after non-displaced supracondylar fractures are very rare. A 7-year-old boy with a non-displaced supracondylar fracture was treated conservatively. Three years later, the patient returned to our hospital complaining of mild elbow pain. Radiography revealed a fishtail deformity of the trochlea due to the premature fusion of the epiphysis. At the latest follow-up at the age of 17 years, only a marginal limitation at the excursion of the elbow was observed, and no additional treatment was needed. Fishtail deformities can occur even after a non-displaced supracondylar fracture. Long-term follow-ups are required in children with distal humeral fractures.

Zoledronic acid for osteoporosis after distal radius fracture surgery: Prospective longitudinal study.

Background: Distal radius fractures (DRFs) are the most frequent first-ever osteoporotic fragility fractures. However, most patients are treated only for fractures and not for osteoporosis. Therefore, we investigated early osteoporosis intervention using zoledronic acid. Methods: This prospective study enrolled 30 patients aged 50 years or older who had no history of fragility fractures or osteoporosis treatment and who underwent surgical treatment for DRFs. Patients whose lumbar spine or femur bone mineral density (BMD) values were less than 80% of the young adult mean (YAM) were treated with a 5-mg intravenous infusion of zoledronic acid. Lumbar spine and femur YAM BMD values, TRACP-5b and PINP were statistically evaluated using the paired t-test. The relationship between adverse effects, age, body mass index (BMI), and creatinine clearance (CCr) was statistically examined using Mann-Whitney's U test. The incidence of the bone fusion and secondary fractures within the 60-months postoperative period were assessed. Results: The mean lumbar spine and femur YAM BMD values before treatment were 76.1 ± 13.1% and 70.7 ± 8.5%. This indicates osteopenia in both locations. These values differed significantly between the pre-treatment period and each subsequent period. Five patients with a target YAM BMD value over 80% within 60 months after treatment were observed. The TRACP-5b and PINP values differed significantly between the pre-treatment period and each subsequent period. Adverse drug reactions were observed in 12 patients (40%). Age, BMI, and CCr did not show statistically significant differences in the occurrence of adverse effects. Bone fusion was confirmed at a mean of 3.6 months postoperatively. Secondary fractures were observed in 3 patients within 60 months after treatment. Conclusion: DRFs occur at a younger age than other fragility fractures, and it is important to intervene aggressively with osteoporosis treatment to prevent secondary fractures. Level of evidence: Level V.

Alteration of chronic inflammatory status by transarterial embolization in frozen shoulder evaluated by fluorine-18 fluorodeoxyglucose positron-emission tomography/computed tomography.

BACKGROUND: Frozen shoulder (FS) is speculated to have an inflammatory etiology. On angiography, abnormal angiogenesis is observed around the affected shoulder, suggesting a possible source of inflammation and pain. The effectiveness and safety of transarterial embolization (TAE) targeting abnormally proliferating blood vessels have been reported. This study investigated changes in chronic inflammatory and hypoxic status before and after TAE in FS by [18F]-fluoro-2-deoxyglucose (FDG) positron-emission tomography/computed tomography as a possible mechanism of the therapeutic response to TAE. METHODS: Fifteen patients with unilateral FS, persistent for more than 6 months, who were refractory to conservative treatments, underwent TAE using the temporary embolic agent imipenem/cilastatin. Patients underwent positron-emission tomography/computed tomography with FDG (as a biomarker of inflammation) before and 8 weeks after TAE. Regional uptake was evaluated by the maximum standardized uptake value. The lesion-side-to-(contralateral-) normal-side uptake ratio was also calculated. Pain and functional scales, range-of-motion, and laboratory tests, including white blood cell, C-reactive protein, interleukin 6, vascular endothelial growth factor, and tumor necrosis factor α were evaluated. RESULTS: On FDG-PET, the average maximum standardized uptake value of the lesion-side was significantly greater than that of the normal-side (maximum standardized uptake value before TAE: 3.11 ± 1.25 vs 1.95 ± 1.15, P = .0001; 8-weeks post-TAE: 2.36 ± 0.74 vs 1.78 ± 0.69, P = .0002). The mean lesion-side-to-(contralateral-) normal-side uptake ratios before TAE (1.71 ± 0.60) decreased after TAE (1.37 ± 0.29, P = .011). The decrease of FDG uptake (-21.1 ± 12.2%) showed a significant correlation with the change in the pain scale score (r = -0.56, P = .039) and extension score (r = -0.59, P = .026). CONCLUSION: Chronic inflammation in FS, as demonstrated by FDG uptake, was decreased after TAE. Thus, chronic inflammation is likely to be an underlying mechanism that should be targeted for symptomatic improvement of frozen shoulder.

Diclofenac-hyaluronate conjugate (diclofenac etalhyaluronate) intra-articular injection for hip, ankle, shoulder, and elbow osteoarthritis: a randomized controlled trial.

BACKGROUND: To evaluate the efficacy and safety of intra-articular injection of diclofenac etalhyaluronate (DF-HA) in patients with osteoarthritis (OA) of the hip, ankle, shoulder, or elbow. METHODS: In this randomized, placebo-controlled, double-blind study in Japan, Japanese patients aged ≥20 years diagnosed with OA of the hip, ankle, shoulder, or elbow were randomly assigned 1:1 to DF-HA 30 mg or placebo (citric acid-sodium citrate buffered solution). Subjects received three injections of the study drug in each joint cavity every 4 weeks and were assessed for 12 weeks after the first injection. The primary endpoint was the mean change from baseline in a diary-based 11-point numerical rating scale (NRS) for pain over 12 weeks, analyzed for each joint. Treatment-emergent adverse events were recorded, and morphological changes in each joint were evaluated radiographically. RESULTS: The study drug (DF-HA vs placebo) was injected into 90, 60, 90, or 50 subjects with OA of the hip, ankle, shoulder, or elbow (46 vs 44, 30 vs 30, 45 vs 45, and 25 vs 25, respectively). The group differences in the mean change from baseline in the pain NRS over 12 weeks were - 0.81 (95% confidence interval: - 1.48 to - 0.13), - 0.07 (- 1.03 to 0.89), 0.15 (- 0.48 to 0.78), and 0.61 (- 0.41 to 1.62) for the hip, ankle, shoulder, and elbow joints, respectively, with statistically significant differences observed only in the hip joint. The change from baseline in the hip joint was greater with DF-HA than placebo at all time points from Weeks 1-12. No clinically significant adverse events or radiographic changes were observed. CONCLUSIONS: Intra-articularly administered DF-HA for hip OA produced a rapid response and was safe, with analgesia maintained for 12 weeks when administered every 4 weeks. TRIAL REGISTRATION: JapicCTI-173,678 (First registered date: 21 August 2017).

Japanese Orthopaedic Association (JOA) clinical practice guidelines on the management of lateral epicondylitis of the humerus - Secondary publication.

BACKGROUND: The guidelines presented herein provide recommendations for the management of patients with lateral epicondylitis of the humerus. These recommendations are endorsed by the Japanese Orthopaedic Association (JOA) and Japan Elbow Society. METHODS: The JOA lateral epicondylitis guideline committee revised the previous guidelines on the basis of the "Medical Information Network Distribution Service Handbook for Clinical Practice Guideline Development 2014", which emphasized the importance of the balance between benefit and harm, and proposed a desirable method for preparing clinical guidelines in Japan. These guidelines consist of 11 clinical questions (CQs), 9 background questions (BQs), and 3 future research questions (FRQs). For each CQ, outcomes from the literature were collected and evaluated systematically according to the adopted study design. RESULTS: The committee proposed recommendations for each CQ by determining the level of evidence and assessing the consensus rate. Physical therapy was the best recommendation with the best evidence. The BQs and FRQs were answered by collecting evidence based on the literature. CONCLUSIONS: The guidelines presented herein were reviewed systematically, and recommendations were proposed for each CQ. These guidelines are expected to be widely used not only by surgeons or physicians but also by other healthcare providers, such as nurses, therapists, and athletic trainers.

Intra-Arterial Infusion of Imipenem/Cilastatin Sodium through a Needle Inserted into the Radial Artery as a New Treatment for Refractory Trapeziometacarpal Osteoarthritis.

PURPOSE: To evaluate the efficacy and safety of intra-arterial infusion of temporary embolic material with/without radiographic monitoring via a needle placed into the radial artery to occlude abnormal neovessels for trapeziometacarpal osteoarthritis. MATERIALS AND METHODS: Thirty-one patients having Eaton stage II or III osteoarthritis, with a symptom duration longer than 6 months, resistant to conservative therapy for at least 3 months were prospectively enrolled. All procedures were performed by infusing imipenem/cilastatin sodium through a 24-gauge needle that was percutaneously inserted into the radial artery. Seven patients underwent the procedure with fluoroscopy, and 21 patients underwent the procedure without fluoroscopy. The mean Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) score, numerical rating scale (NRS), and Patient Global Impression of Change (PGIC) scale were evaluated before and at 2, 6, and 24 months after the first procedure. RESULTS: Technical success was 100%. The mean procedure time (from the beginning of local anesthesia to the removal of needle) was 2.9 minutes ± 1.6. The QuickDASH score improved from the baseline to 2, 6, and 24 months (49.2 ± 11.2 vs 22.1 ± 11.2, 20.9 ± 16.6, and 19.5 ± 16.1, respectively, all P <.001). The NRS improved from the baseline to 2, 6, and 24 months (7.2 ± 1.1 vs 3.1 ± 1.8, 2.8 ± 2, and 2.5 ± 2.1, respectively, all P <.001). Improvement on PGIC was observed in 84%, 81%, and 77% of patients at 2, 6, and 24 months, respectively. No major adverse events were encountered. CONCLUSIONS: Intra-arterial infusion of temporary embolic material is a feasible treatment option for trapeziometacarpal osteoarthritis.

Anatomical bi-cruciate retaining TKA improves gait ability earlier than bi-cruciate stabilized TKA based on triaxial accelerometery data: A prospective cohort study.

BACKGROUND: Total knee arthroplasty (TKA) is a common and cost-effective surgical treatment for osteoarthritis of the knee. However, only 82-89% of patients who performed TKA are satisfied with the postoperative outcomes. Therefore, bi-cruciate retaining (BCR) TKA is re-attracting attention. By retaining the anterior cruciate ligament (ACL), the knee may obtain the kinematic pathway that are closer to the native knee. The aim of the present study is to compare the ability to walk before and after surgery in patients who underwent bi-cruciate retaining total knee arthroplasty (BCR TKA) versus bi-cruciate stabilized (BCS) TKA during the early postoperative period. METHODS: Subjects included patients who underwent BCR TKA (10 knees) and BCS TKA (15 knees). We administered 10-meter gait tests before surgery and at 6 weeks and 3 months after surgery. We collected the following triaxial accelerometery data with a portable gait analyzer: walking time, number of steps, velocity, stride length, and coefficient of variability (CV) of double-leg support time while walking. RESULTS: Patients who underwent BCR TKA improved their gait ability [walking time (p < 0.01), number of steps (p < 0.05), velocity (p < 0.01), and stride length (p < 0.01) more than those who received BCS TKA at 6 weeks after surgery. BCR TKA improved gait ability (walking time, number of steps, velocity, and stride length) more than BCS TKA at 6 weeks after surgery. At 6 weeks after surgery, CV of double-leg support time while walking improved more in the BCR TKA group than in the BCS TKA group (p < 0.05). CONCLUSIONS: BCR TKA is associated with improved gait ability in the early postoperative period.

Robotic-assisted total knee arthroplasty improves the outlier of rotational alignment of the tibial prosthesis using 3DCT measurements.

BACKGROUND: The aim of the present study was to compare the accuracy of prosthetic alignment with three-dimensional computed tomography (3DCT) measurements following total knee arthroplasty (TKA) performed using a robotic-assisted surgical technique versus a conventional TKA. METHODS: 41 TKAs were performed with a handheld robotic-assisted surgical procedure (Robot group) between 2019 and 2020. Another 41 patients underwent TKA with a conventional manual surgical procedure (Manual group) using the same prosthesis. The operation durations between both groups were investigated. 3DCT scans of the entire lower extremities were taken before and after the surgery and femoral and tibial alignments in the coronal, sagittal, and axial planes were measured using computer software. The differences in prosthetic alignment and translation between the preoperative 3DCT plan and postoperative 3DCT image were also measured. RESULTS: There were no statistically significant differences in the post-operative outliers of the femorotibial angle between the groups. In the tibial-axial plane, the mean of prosthetic alignment in the anteroposterior plane was 4.0° in the Robot group and 6.7° in the Manual group (p < 0.01). The rate of outliers for tibial-axial alignment in the Robot group was significantly less than in the Manual group (p < 0.01). There were no statistically significant differences in prosthetic translation in the proximal-distal, anterior-posterior and medial-lateral orientations between the groups. CONCLUSIONS: In a radiologic study using 3DCT, robotic-assisted TKA reduced the outliers for rotational alignment of the tibial prosthesis in comparison to conventional TKA, which can lead to improved tracking of the femoral-tibial bearing surfaces.

Robotic-Assisted Total Knee Arthroplasty for Distal Femur Fracture with Lateral Knee Osteoarthritis.

Introduction. Open reduction and internal fixation (ORIF) of compound fractures around the knee in elderly patient raise concerns about long-term postoperative external fixation and complications. Total knee arthroplasty (TKA) has been proposed as an alternative solution. We report a case where robotic-assisted (RA) TKA was used to treat lateral knee osteoarthritis (OA) with distal femur fracture. Case Presentation. A 90-year-old female visited our hospital with complications of sustained knee pain after a fall at home. Fracture line from the trochlea to the intercondylar notch was diagnosed on plain radiographs, and prior to this injury, the patient was receiving conservative treatment for lateral OA. We selected a conventional TKA over ORIF because the latter is associated with residual pain and the need for long-term immobilization, which can lead to other complications. However, the fracture site was the entry point for intramedullary rod, and there was concern that the fracture site would be displaced by conventional TKA. Therefore, the unique aspect of the case is that the technique utilized involved robotic milling using the Navio system while temporarily stabilizing the fracture using two tracker pins. RA TKA could determine osteotomy and implant placement by predicting the postoperative patient's soft tissue balance for no medial loosening and lateral contracture. The arthritic cartilage and bone were then methodically removed using the handheld sculptor. After immobilizing the fracture site with a bone grasper before removing the pin tracker, reaming of the femur and insertion of a stem prosthesis with semiconstrained were performed. Primary RA TKA is a viable option for intra-articular fractures in elderly patients with advanced knee osteoarthritis.

Minimally invasive surgery total knee arthroplasty is less popular, but the prosthesis designed specifically for MIS provides good survival and PROMs with a minimum follow-up of 10 years.

BACKGROUND: The concept of minimally invasive surgery (MIS) was introduced in total knee arthroplasty (TKA) in the late 1990s. The number of MIS TKAs has clearly decreased in recent years. An implant designed specifically for MIS TKA has been used all over the world, but there are no reports of long-term postoperative results. The purpose of this study was to characterize long-term clinical results with a minimum follow-up of 10 years. METHODS: This retrospective study included 109 consecutive patients with 143 NexGen CR-Flex prostheses, which are MIS tibial component prostheses designed specifically for MIS TKA. Twelve-year survival analysis was performed using Kaplan-Meier method. Revision surgery for any reason was the endpoint. Long-term clinical and radiographic results of 74 knees (55%) in 60 patients with more than 10 years of follow-up were analyzed. RESULTS: The cumulative survival rate of the single-radius posterior-stabilized TKA of 74 knees was 94.7% (95% confidence interval, 90-99%) at 12 years after surgery. Seven knees (9%) required additional surgery during the 10-year follow-up because of periprosthetic infections. Mean postoperative Knee Society knee score and functional score were 91 and 74 points, respectively. There were no cases of prosthesis breakage, polyethylene wear, or aseptic loosening of the prosthesis. CONCLUSION: The prosthesis designed specifically for MIS TKA is associated with good survival and clinical results with a minimum follow-up of 10 years, even though MIS TKA has become less popular. LEVEL OF EVIDENCE: III.

Short-term results and surgical technique of arthroscopic centralization as an augmentation for medial meniscus extrusion caused by medial meniscus posterior root tear.

INTRODUCTION: The purpose of this study was to perform medial meniscus (MM) centralization for medial meniscus extrusion (MME) associated with medial meniscus posterior root tear (MMPRT) and to examine the short-term results. The hypothesis is that arthroscopic centralization as an augmentation of MMPRT repair improves clinical outcomes and the extrusion distance of MM in short-term results. MATERIALS AND METHODS: Twenty-six patients (mean age 62.1 ± 6.0 years) who underwent arthroscopic centralization as an augmentation of MMPRT repair were included. Clinical evaluation was performed before and 2 years after surgery using Lysholm score and knee injury and osteoarthritis outcome score (KOOS). Image evaluation used MRI and plain X-ray images. The extrusion distance and MME ratio were compared on MRI images before and 2 years after surgery. The degree of osteoarthritis (OA) was evaluated using Kellgren-Lawrence classification. The degree of OA and hip-knee-ankle (HKA) angle were compared by plane X-ray images before and 2 years after surgery. RESULTS: In clinical results, both Lysholm score and KOOS improved significantly after surgery. In image evaluation, the extrusion distance decreased significantly from 4.8 ± 0.7 mm before surgery to 2.7 ± 0.3 mm 2 years after surgery (p < 0.05). The MME ratio was significantly improved from 40.2 ± 7.0% before surgery to 22.6 ± 3.6% after surgery (p < 0.05). There was no significant difference in HKA angle at 2 years after surgery (p = 0.13). CONCLUSIONS: The arthroscopic centralization for medial meniscal extrusion associated with MMPRT significantly improved clinical outcomes and the extrusion distance of MM. It is also one of the surgical techniques that can suppress medial meniscus extrusion. LEVEL OF EVIDENCE: IV, therapeutic case series.

Arthroscopic ankle lateral ligament repair alone versus arthroscopic ankle lateral ligament repair with reinforcement by inferior extensor retinaculum.

PURPOSE: This study aimed to compare the clinical outcomes and postoperative activities of arthroscopic ankle lateral ligament (ALL) repair alone with arthroscopic ALL repair and reinforcement by the inferior extensor retinaculum (IER) for chronic ankle instability (CAI). MATERIALS AND METHODS: All patients who underwent arthroscopic repair for CAI between 2017 and 2019 were evaluated. The Japanese Society for Surgery of the Foot (JSSF) scale and self-administered foot evaluation questionnaire (SAFE-Q), and duration between the surgery and walking without any support, jogging, and complete return to sports were evaluated and compared. The exclusion criteria were (1) follow-up period of < 1 year after surgery, (2) the presence of associated ankle lesions requiring treatment during the same operative procedure, including patients with subfibular ossicle bigger than 5 mm on radiographs, chondral or osteochondral defect, bony impingement, deltoid ligament tear, fibular tendon pathology, or posterior ankle impingement, and (3) patients who underwent revision surgery. RESULTS: We identified 126 patients who underwent surgery for CAI and subsequently excluded 36 patients on account of a short follow-up period (< 1 year), additional surgery, and previous surgery. The remaining 90 eligible patients included arthroscopic ALL repair alone (group A, n = 44) and arthroscopic ALL repair with reinforcement by the inferior extensor retinaculum (group G, n = 46) groups. There was no significant difference in the postoperative activities nor in the preoperative or postoperative JSSF scale and SAFE-Q between the two groups. However, significant differences were seen in the mean surgical time (15.5 ± 8.1 vs 20.1 ± 7.6, P = 0.013). CONCLUSION: This study showed no difference in clinical outcomes between the two groups. However, arthroscopic ALL repair with reinforcement by IER resulted in a longer surgical time than arthroscopic ALL repair alone. LEVEL OF EVIDENCE: Retrospective comparative study, level III.

Midterm Comparison of Tibial Fixation between Posterior Cruciate-Retaining and Substituting Porous Tantalum Total Knee Arthroplasty: Three-Dimensional Computed Tomography Analysis.

Porous tantalum tibial component is durable with excellent bone ingrowth, higher knee scores, and long-term survivorship. However, to our knowledge, the effect of posterior cruciate-retaining (CR) and posterior cruciate-substituting (PS) porous tantalum tibial component has not been reported. The aim of the current study was to investigate the prosthetic bone quality between CR porous tantalum tibial component and PS using three-dimensional multi-detector-row computed tomography (3D-MDCT). Porous twenty-two (22) CR total knee arthroplasties and 22 PS received 3D-MDCT at every 6 months up to 5.5 years postoperatively to assess prosthetic bone quality (bone marrow contents/tissue volumes [BMC/TV, mg/cm3]) underneath the pegs of porous tantalum modular tibial component. Clinical outcomes (Knee Society score [KSS], Western Ontario and McMaster Universities (WOMAC), FJS-12, Patella score) were evaluated at a minimum follow-up period of 5.5 years. No statistically significant differences were found in age, gender, body mass index, KSS, and BMC/TV volumes in the proximal tibia between the two groups before total knee arthroplasty (TKA). There were also no significant differences between the CR and PS groups with regard to BMC/TV at every 6 months up to 5.5 years after TKA. At 5.5 years postoperatively, there was no significant difference between the two groups in terms of the KSS, WOMAC, forgotten joint score (FJS-12), and Patella score. The present study revealed that the prosthetic bone quality of the CR porous tantalum tibial component and PS were equivalent at every 6 months up to 5.5 years after TKA. This study reflects level II evidence.

Erratum to "Greater postoperative relatively medial loose gap at 90° of flexion for varus knees improves patient-reported outcome measurements in anatomical bi-cruciate retaining total knee arthroplasty" [The Knee 27(5) (2020) 1534-1541]".

BACKGROUND: The purpose of the present study was to measure the intraoperative joint gap using tensor device and pre- and, postoperative joint stability at 0, 30 and 90° of flexion using stress radiography and to identify whether these factors influence patient-reported outcome measurement (PROM) in anatomical bi-cruciate retaining (BCR) knee arthroplasty (TKA). METHODS: Fifty-three knees with preoperative varus osteoarthritis of the knee underwent anatomical BCR TKA with oblique 3° angle femorotibial joint line. The intraoperative medial and lateral joint gap using a tensor device and gap difference (lateral minus medial; varus laxity) were also calculated. Postoperative joint stability was measured using stress radiographs. PROM was also evaluated at 1.5 years postoperatively. The effect of intraoperative and postoperative joint stabilities on PROMs were analyzed using Spearman's rank correlation analysis. RESULTS: Intraoperative greater difference between medial joint gap at 140° and 0° of flexion showed significant positive correlation with postoperative function of patellofemoral joint. Intraoperative varus laxity at extension improved postoperative symptoms in 2011 Knee Society Score (2011 KSS); greater postoperative lateral stability at 30 and 90° of flexion with the varus stress test was associated with the better patient expectation in 2011 KSS. Postoperative medial laxity at 90° of flexion with the valgus stress test positively correlated with the patient expectation and satisfaction in 2011 KSS. CONCLUSION: Surgeons should notice that the postoperative lateral stability and medial laxity at 90° of flexion improved PROM in anatomical BCR TKA.

Greater postoperative relatively medial loose gap at 90° of flexion for varus knees improves patient-reported outcome measurements in anatomical bi-cruciate retaining total knee arthroplasty.

BACKGROUND: The purpose of the present study was to measure the intraoperative joint gap using tensor device and pre- and, postoperative joint stability at 0, 30 and 90° of flexion using stress radiography and to identify whether these factors influence patient-reported outcome measurement (PROM) in anatomical bi-cruciate retaining (BCR) knee arthroplasty (TKA). METHODS: Fifty-three knees with preoperative varus osteoarthritis of the knee underwent anatomical BCR TKA with oblique three-degree angle femorotibial joint line. The intraoperative medial and lateral joint gap using a tensor device and gap difference (lateral minus medial; varus laxity) were also calculated. Postoperative joint stability was measured using stress radiographs. PROM was also evaluated at 1.5 years postoperatively. The effect of intraoperative and postoperative joint stabilities on PROMs were analyzed using Spearman's rank correlation analysis. RESULTS: Intraoperative greater difference between medial joint gap at 140° and 0° of flexion showed significant positive correlation with postoperative function of patellofemoral joint. Intraoperative varus laxity at extension improved postoperative symptoms in 2011 Knee Society Score (2011 KSS); greater postoperative lateral stability at 30 and 90° of flexion with the varus stress test was associated with the better patient expectation in 2011 KSS. Postoperative medial laxity at 90° of flexion with the valgus stress test positively correlated with the patient expectation and satisfaction in 2011 KSS. CONCLUSIONS: Surgeons should notice that the postoperative lateral stability and medial laxity at 90° of flexion improved PROM in anatomical BCR TKA.

In vitro evaluation of the tension band suture method for proximal humerus fracture treatment.

BACKGROUND: Proximal humeral fractures are common, and more than half occur in patients over 65 years of age. Operative treatment may be recommended for displaced, complicated fractures; however, surgery may lead to displacement of the greater tuberosity or humeral head. Supplemental tension band sutures have been recommended to prevent such a complication. In this study, we investigate the best combination of suture, washer, and threading angle for proximal humeral fractures from a mechanical view. METHODS: The mechanical durability of 18 combinations of suture materials (Fiberwire, Ethibond, and Surgilon), threading washers (ring washer, disc washer), and threading angles (15 or 45°) were examined via a cyclic loading test. RESULTS: The most durable combination in the cyclic loading test consisted of threading the Fiber Wire to the washer ring using only one hole (ring washer-1) at 45°. In contrast, the most vulnerable combination was threading Ethibond to the washer disc at 15°. Breakage of all suture materials occurred at the suture-washer interface, and no failure or loosening of the knots was observed. FiberWire gradually eroded until the loss of equilibrium; whereas the rupture of Ethibond and Surgilon occurred suddenly. CONCLUSIONS: From a mechanical viewpoint, we demonstrated that applying a supplemental tension band suture using FiberWire with a single-hole ring washer threaded at a wider angle is recommended.

Autologous chondrocyte implantation with a Reveille cartilage processor for articular cartilage injury: a case report.

Autologous chondrocyte implantation (ACI) is an important operative option when repairing cartilage defects of the knee. This report introduces a new product development with one-stage ACI using a Reveille Cartilage Processor (Reveille CP) as well as the assessment of MRI and clinical results at a 1-year follow-up. The report compared cases between a 42-year-old female who underwent ACI surgery using Reveille CP and a 51-year old female who received treatment with two-stage ACI of tissue-engineered cartilage-like tissue (J-TEC Autologous Chondrocyte Cultured Cartilage [JACC]). One year after JACC, magnetic resonance imaging (MRI) showed signal intensity area in the grafted area, while patients with Reveille CP showed greater thickness than the surrounding healthy cartilage. The Lysholm, pain and QOL scores of Knee Injury and Osteoarthritis Outcome (KOOS) at one 1 year after surgery with Reveille CP were higher than JACC.

The influence of tibiofemoral joint forces on patient-reported outcome measurements after bicruciate stabilized total knee arthroplasty.

OBJECTIVE: Insall advocated that a successful clinical outcome of total knee arthroplasty (TKA) depends on soft tissue balance procedure. Spacer blocks, balancer, and instrumented tibial sensor (VERESENSE, OrthoSensor, Dania, Florida, USA) are the current methods of soft tissue balancing during TKA. The purpose of the study is to assess intraoperative medial and lateral tibiofemoral compressive force (TFCF) using novel insert sensor and investigate the relationship between TFCF and patient-reported outcome measurements (PROMs). METHODS: Twenty-five patients who underwent bicruciate stabilized (BCS) TKA were evaluated retrospectively. We measured intraoperative medial and lateral TFCF in neutral position as well as the force ratio (FR %:medial TFCF/medial + lateral TFCF) in varus and valgus position using the novel insert sensor throughout the range of motion (ROM) and assessed the relationship between intraoperative medial and lateral TFCF and PROM at 6 months after TKA. RESULTS: Medial TFCF increased and lateral TFCF decreased throughout ROM. The mean FR was 0.44% ± 0.22 throughout ROM. Medial and lateral TFCF differences at 60° of ROM in neutral position showed a positive correlation with physical function in Western Ontario and McMaster Universities scores (r = 0.60, p < 0.05). Medial and lateral TFCF differences at 30° and 140° of ROM in valgus stress test showed a positive correlation with symptoms in 2011 Knee Society Scores (r = 0.49, p < 0.05; r = 0.51, p < 0.05). CONCLUSION: The present study revealed that BCS TKA reproduces the coronal laxity, which is similar to healthy knee. These results suggest that intraoperative medial stability is important for function and symptoms, therefore, surgeons should not release medial soft tissue for achieving better clinical outcomes after BCS TKA. LEVEL OF EVIDENCE: II.