Comparison of Time Taken in Conventional versus Active Robotic-Assisted Total Knee Arthroplasty.

Background: Computer- and robotic-assisted total knee replacement procedures have been shown to improve the accuracy of the implant size. It also allows dynamic confirmation of the implant and limb alignment during total knee arthroplasty (TKA). The major inhibition of the arthroplasty surgeon in adapting to the robotic-assisted TKA (RA-TKA) is the extra time spent during the registration process and milling of the bone with the robot. The aim of the study was to ascertain the extra time spent during these 2 steps as compared to the conventional TKA (C-TKA). Methods: It is a prospective study involving 30 patients each in the conventional TKA and RA-TKA operated by the same surgical team. The patients were given a choice between the C-TKA and RA-TKA and consecutive 30 cases in each group were studied by an independent observer. In the C-TKA group, the time for the application of appropriate zigs and execution of the bone cuts and soft-tissue release was recorded whereas in the RA-TKA group, the time taken for fixation of the tibial and femoral arrays and bone registration and bone milling with robot and required soft-tissue release was measured. Results: The preoperative patient characteristics were the same in both groups. The time taken in the C-TKA and RA-TKA groups was 24.77 ± 1.92 minutes and 25.03 ± 3.27 minutes, respectively, which is statistically insignificant (p = 0.709). Conclusions: The study findings show that RA-TKA does not take additional time than C-TKA.

Comparison of imageless robotic assisted total knee arthroplasty and conventional total knee arthroplasty: early clinical and radiological outcomes of 200 knees.

The aim of this study was to compare the short term clinical and radiological outcomes of imageless robotic and conventional total knee arthroplasty (TKA) and to estimate the accuracy of the two techniques by analysing the outliers after TKA. We have evaluated 200 consecutive knees (158 patients), 100 knees undergoing robotic TKA, and 100 knees treated with conventional TKA. Demographic parameters like age, gender, body mass index, diagnosis and range of motion were obtained. Knee society score (KSS) and Knee society functional score (KSS-F) were used for clinical evaluation. Mechanical alignment (Hip-knee-ankle angle), proximal tibial angle (MPTA), distal femoral angle (LDFA) and tibial slope were analysed for radiological results and outliers were compared between both groups. Outliers were defined when the measured angle exceeded ± 3° from the neutral alignment in each radiological measurement on the final follow-up radiograph.The minimum follow-up was 6 months (range, 6 to 18 months). The preoperative mean HKA angle was 169.7 ± 11.3° in robotic group and 169.3 ± 7.3° in conventional group. There was significant improvement in HKA, LDFA, MPTA and tibial slope compared to the preoperative values in both the groups (p < 0.01). The number of HKA, LDFA and tibial slope outliers were 31, 29 and 37, respectively, in the conventional group compared to 13, 23 and 17 in the robotic group (p < 0.01). There was a significant improvement in the KSS and KSS-F functional scores postoperatively in both the groups (p < 0.01). However, there was no significant difference in the functional scores between the groups postoperatively (p = 0.08). This study showed excellent improvement with both imageless robotic and conventional TKA, with similar clinical outcomes between both groups. However, radiologically robotic TKA showed better accuracy and consistency with fewer outliers compared with conventional TKA.

Is Using a Ring External Fixator in the Treatment of Congenital Pseudarthrosis of the Tibia Associated With Better Results or Using a Locking Plate?

BACKGROUND: Congenital pseudarthrosis of the tibia (CPT) is a rare disease. CPT is often unilateral and occurs between the middle and distal third of the tibia. Concurrent involvement of the fibula is present in more than half of cases. histologic studies indicate the presence of fibrous hamartoma tissue and a sick periosteum, which leads to recalcitrant bone fracture and, eventually, pseudoarthrosis. Although there are various surgical techniques, we intend to compare the 2 methods of external fixation versus internal plating. METHODS: Demographic data were collected from 26 patients with frank pseudoarthrosis. After exclusion criteria, patients were compared in groups A (12 patients) and B (11 patients). Resection of hamartoma and sclerotic bone, intramedullary rodding and autologous bone, and periosteal grafting were performed for all patients. In group A, we used a ring external fixator for compression and rotational stability, but in group B, a locking plate was used for these purposes. RESULTS: Plating takes less time to use during surgery. In group A, the primary bony union was obtained in 67% of patients, while in group B, 82% of patients had a primary union. Meanwhile, the average time till the final union in group A was 6 months, while in group B, this time was 3.5 months. Positive union mass was obtained in 58% of the patients in group A and 82% of group B. In addition, plating prevented ankle valgus deformity in group B. CONCLUSIONS: Permanent intramedullary rodding is a surgical requirement for correction of deformity and refracture prevention, but additional stability can be achieved with the use of a ring external fixator or internal plate. Cross union and positive union mass are 2 important factors in the treatment of pseudoarthrosis; these results are achieved to a greater extent and in a shorter period of time using the plate. LEVEL OF EVIDENCE: level IV - case series.

[Subtuberosity anterior closing wedge osteotomy to correct the increased posterior slope of the tibial plateau]. / Subtuberositäre anterior schließende Osteotomie zur Korrektur der erhöhten posterioren Reklination des Tibiaplateaus.

OBJECTIVE: Reduction of increased reclination of the tibial plateau (posterior slope) to improve the anterior stability of the knee joint. INDICATIONS: Increased posterior reclination of the tibial plateau greater than 12° in combination with recurrent instability after anterior cruciate ligament (ACL) reconstruction. CONTRAINDICATIONS: Hyperextension of more than 15° (relative). SURGICAL TECHNIQUE: Anterior skin incision approximately 8-10 cm above the tibial tuberosity. Insertion of two converging guidewires directly below the patellar tendon ending obliquely in the area of the posterior cruciate ligament (PCL) insertion. Control of the wire position with the image intensifier core. Oscillating saw osteotomy. Removal of the wedge and closure of the osteotomy. Osteosynthesis with interfragmentary screw and medial angle-stable plate. POSTOPERATIVE MANAGEMENT: Partial load with 10-20 kg for 2 weeks, then step by step increase in load. Mobility: free. RESULTS: To date we have operated on 36 patients with recurrent instability after ACL reconstruction (20 men, 16 women, average age 34.4 years) in the manner described in this article. In 25 cases, enlarged bone tunnels were filled with allogeneic bone at the same time. The posterior slope of the tibial plateau could be reduced from an average of 14.5° to 8.8°. In 28 cases another ACL reconstruction was performed after an interval of 4-12 months. The Lysholm score significantly increased from 76.3 points to 89.2 points.

Comparative analysis of gait: Similar coronal but different sagittal effects between closing-wedge and opening-wedge high tibial osteotomy.

BACKGROUND: High tibial osteotomy is an established surgical option for medial compartment osteoarthritis of the knee with varus alignment. It can be divided into open wedge and closing wedge by operative technique. Although they have fundamental differences, little is known about the biomechanical consequences of the two surgical methods. METHODS: Thirty-eight patients with medial compartment osteoarthritis who underwent high tibial osteotomy (19 open-wedge and 19 closing-wedge) were retrospectively reviewed. Clinical scores and radiological measurements were assessed until postoperative two years. Gait analysis was performed preoperatively and again at postoperative one year. FINDINGS: Varus alignment was corrected in both groups without a significant difference between them (p = 0.543). However, posterior tibial slope was higher, and the Blackburne-Peel ratio was lower in the open wedge osteotomy group after surgery (both p < 0.001). Reduction of dynamic knee varus and knee adduction moment were observed in both groups without significant differences. However, after surgery, average knee range of motion (63.3° vs 57.3°, p < 0.001) and the magnitude of knee flexion moment was significantly lower (p = 0.005) in the closing wedge group. There were no significant differences in the Kujala Anterior Knee Pain Scale and the occurrence of patellofemoral arthritis between the groups postoperatively. INTERPRETATION: After osteotomy, a smaller average knee range of motion in the sagittal plane and a higher knee flexion moment were observed in the open wedge osteotomy group, suggesting quadriceps muscle avoidance. However, no differences in clinical scores or the short-term occurrence of patellofemoral arthritis were noted between the two surgical techniques.

Efficacy of cementless porous tantalum tibial components versus cemented tibial components in primary total knee arthroplasty: A meta-analysis.

BACKGROUND: Total knee arthroplasty involves the use of cemented tibial components for fixation. In recent years, cementless porous tantalum tibial components have been increasingly utilized. The aim of this meta-analysis was to compare the efficacy of cementless porous tantalum tibial components with traditional cemented tibial components in terms of postoperative outcomes following total knee arthroplasty. METHODS: Relevant literature was retrieved from Cochrane Library, PubMed, Embase, and Web of Science using the search terms "(trabecular metal OR Porous tantalum)" AND "knee" up to July 2023. The weighted mean difference with a 95% confidence interval was used as the effect size measure to evaluate the functional recovery of the knee joint, radiological analysis, complications, and implant revisions between cementless porous tantalum tibial components and traditional cemented tibial components after total knee arthroplasty. Review Manager 5.3 was utilized to conduct a comparative analysis of all included studies. RESULTS: Nine studies with a total of 1117 patients were included in this meta-analysis, consisting of 447 patients in the porous tantalum group and 670 patients in the cemented group. Radiological analysis demonstrated that the porous tantalum group had better outcomes than the cemented group (P < .05). The combined results for the 5-year and 10-year follow-ups, range of motion, Western Ontario and McMaster University Osteoarthritis Index, complications, and implant revisions showed no significant differences between the porous tantalum and cemented groups. CONCLUSION: The results of the 5-year and 10-year follow-ups indicate that the use of cementless porous tantalum tibial components is comparable to traditional cemented tibial components, with no significant advantages observed. However, at the 5-year follow-up, the porous tantalum group demonstrated a good bone density in the proximal tibia. Future studies with a larger sample size, long-term clinical follow-up, and radiological results are needed to verify the differences between the 2 implants.

Application of double plate fixation combined with Masquelet technique for large segmental bone defects of distal tibia: a retrospective study and literature review.

BACKGROUND: There is no effective consensus on the choice of internal fixation method for the Masquelet technique in the treatment of large segmental bone defects of the distal tibia. Thus, the study aimed to investigate the outcomes of the Masquelet technique combined with double plate fixation in the treatment of large segmental bone defects. METHODS: This was a retrospective study involving 21 patients with large segmental bone defects of the distal tibia who were treated between June 2017 and June 2020. The length of bone defect ranged from 6.0 cm to 11 cm (mean, 8.19 cm). In the first stage of treatment, following complete debridement, a cement spacer was placed to induce membrane formation. In the second stage, double plate fixation and autologous cancellous bone grafting were employed for bone reconstruction. Each patient's full weight-bearing time, bone healing time, and Iowa ankle score were recorded, and the occurrence of any complications was noted. RESULTS: All patients were followed up for 16 to 26 months (mean, 19.48 months). The group mean full weight-bearing time and bone healing time after bone grafting were 2.41 (± 0.37) months and 6.29 (± 0.66) months, respectively. During the treatment, one patient had a wound infection on the medial side of the leg, so the medial plate was removed. The wound completely healed after debridement without any recurrence. After extraction of iliac bone for grafting, one patient had a severe iliac bone defect, which was managed by filling the gap with a cement spacer. Most patients reported mild pain in the left bone extraction area after surgery. The postoperative Iowa ankle score range was 84-94 (P < 0.05). In this cohort, 15 cases were rated as "excellent", and 6 cases as "good" on the Iowa ankle scoring system. CONCLUSION: The Masquelet technique combined with double plate fixation is a safe and effective method for the treatment of large segmental bone defects of the distal tibia.

[Application of antibiotic bone cement-coated plates internal fixation for primary treating Gustilo type â ¢B tibiofibular open fracture].

Objective: To explore the effectiveness of using antibiotic bone cement-coated plates internal fixation technology as a primary treatment for Gustilo type ⅢB tibiofibular open fractures. Methods: The clinical data of 24 patients with Gustilo type ⅢB tibiofibular open fractures who were admitted between January 2018 and December 2021 and met the selection criteria was retrospectively analyzed. Among them, there were 18 males and 6 females, aged from 25 to 65 years with an average age of 45.8 years. There were 3 cases of proximal tibial fracture, 6 cases of middle tibial fracture, 15 cases of distal tibial fracture, and 21 cases of fibular fracture. The time from injury to emergency surgery ranged from 3 to 12 hours, with an average of 5.3 hours. All patients had soft tissue defects ranging from 10 cm×5 cm to 32 cm×15 cm. The time from injury to skin flap transplantation for wound coverage ranged from 1 to 7 days, with an average of 4.1 days, and the size of skin flap ranged from 10 cm×5 cm to 33 cm×15 cm. Ten patients had bone defects with length of 2-12 cm (mean, 7.1 cm). After emergency debridement, the tibial fracture end was fixed with antibiotic bone cement-coated plates, and the bone defect area was filled with antibiotic bone cement. Within 7 days, the wound was covered with a free flap, and the bone cement was replaced while performing definitive internal fixation of the fracture. In 10 patients with bone defect, all the bone cement was removed and the bone defect area was grafted after 7-32 weeks (mean, 11.8 weeks). The flap survival, wound healing of the affected limb, complications, and bone healing were observed after operation, and the quality of life was evaluated according to the short-form 36 health survey scale (SF-36 scale) [including physical component summary (PCS) and mental component summary (MCS) scores] at 1 month, 6 months after operation, and at last follow-up. Results: All 24 patients were followed up 14-38 months (mean, 21.6 months). All the affected limbs were successfully salvaged and all the transplanted flaps survived. One case had scar hyperplasia in the flap donor site, and 1 case had hypoesthesia (grade S3) of the skin around the scar. There were 2 cases of infection in the recipient area of the leg, one of which was superficial infection after primary flap transplantation and healed after debridement, and the other was sinus formation after secondary bone grafting and was debrided again 3 months later and treated with Ilizarov osteotomy, and healed 8 months later. The bone healing time of the remaining 23 patients ranged from 4 to 9 months, with an average of 6.1 months. The scores of PCS were 44.4±6.5, 68.3±8.3, 80.4±6.9, and the scores of MCS were 59.2±8.2, 79.5±7.8, 90.0±6.6 at 1 month, 6 months after operation, and at last follow-up, respectively. The differences were significant between different time points ( P<0.05). Conclusion: Antibiotic bone cement-coated plates internal fixation can be used in the primary treatment of Gustilo type ⅢB tibiofibular open fractures, and has the advantages of reduce the risk of infection in fracture fixation, reducing complications, and accelerating the functional recovery of patients.

[Research progress of femoral bone tunnel positioning in anterior cruciate ligament reconstruction].

Objective: To review the concept and methods of femoral bone tunnel positioning in anterior cruciate ligament (ACL) reconstruction, in order to provide a reference for clinical treatment. Methods: The relevant literature on the concept and methods of femoral bone tunnel positioning in ACL reconstruction in domestic and international research was extensively reviewed. Results: The position of the femoral bone tunnel is a key factor in determining the prognosis of ACL reconstruction. The concept of femoral bone tunnel positioning in ACL reconstruction has experienced isometric reconstruction, anatomical reconstruction, Ribbon-like theory, I.D.E.A.L. theory, and nearly isometric reconstruction theory. The femoral bone tunnel positioning technique is also changing with the in-depth study of the anatomy and biomechanics of the ACL, and each bone tunnel positioning technique has its own advantages and disadvantages. Over-The-Top technique is now mainly used for ACL revision; the clock-face positioning method is basically no longer applicable due to the large error, poor stability, and low retrievability; the bone landmarks positioning method (the lateral condyle of the femur's Resident's ridge and bifurcation ridge, and the the apex of the deep cartilage), which is now mostly used clinically due to the more constant anatomical landmarks. The quadrant method under X-ray fluoroscopy is more cumbersome to implement intraoperatively, so it is mainly used for academic research; computer navigation-assisted positioning has gradually become popular in recent years, which is highly accurate, avoids the influence of human factors on the positioning of the bone tunnel, and has a very good prospect of application; three-dimensional printing-assisted positioning technology, which is accurate in positioning, with a high degree of reproducibility and a short learning curve. Conclusion: The concept of femoral bone tunnel positioning for ACL reconstruction has undergone several evolutions, reflecting the deepening of the understanding of ACL and the improvement of the clinical results of reconstruction. The precision, personalization, and intelligence of positioning techniques are the focus of current and future development.

Robot-assisted anterior cruciate ligament reconstruction based on three-dimensional images.

Background Tunnel placement is a key step in anterior cruciate ligament (ACL) reconstruction. The purpose of this study was to evaluate the accuracy of bone tunnel drilling in arthroscopic ACL reconstruction assisted by a three-dimensional (3D) image-based robot system. Methods Robot-assisted ACL reconstruction was performed on twelve freshly frozen knee specimens. During the operation, three-dimensional images were used for ACL bone tunnel planning, and the robotic arm was used for navigation and drilling. Twelve patients who underwent traditional arthroscopic ACL reconstruction were included. 3D computed tomography was used to measure the actual position of the ACL bone tunnel and to evaluate the accuracy of the robotic and traditional ACL bone tunnel. Results On the femoral side, the positions of robotic and traditional surgery tunnels were 29.3 ± 1.4% and 32.1 ± 3.9% in the deep-to-shallow direction of the lateral femoral condyle (p = 0.032), and 34.6 ± 1.2% and 21.2 ± 9.4% in the high-to-low direction (p < 0.001), respectively. On the tibial side, the positions of the robotic and traditional surgical tunnels were located at 48.4 ± 0.9% and 45.8 ± 2.8% of the medial-to-lateral diameter of the tibial plateau (p = 0.008), 38.1 ± 0.8% and 34.6 ± 6.0% of the anterior-to-posterior diameter (p = 0.071), respectively. Conclusions In this study, ACL reconstruction was completed with the assistance of a robot arm and 3D images, and the robot was able to drill the bone tunnel more accurately than the traditional arthroscopic ACL reconstruction.

[Prognostic factors associated with failure of modular knee arthroplasty in oncologic patients]. / Factores pronósticos asociados al fracaso de la artroplastía modular de rodilla en pacientes oncológicos.

INTRODUCTION: reconstruction of large bone defects using modular knee arthroplasty (MKA) presents a significant challenge in terms of functionality. The objective of the present work was to identify the different prognostic factors associated with failure of MKA in cancer patients. MATERIAL AND METHODS: a retrospective cohort study was conducted, including patients with a diagnosis of musculoskeletal tumor in the distal femur or proximal tibia, who underwent MKA between January 1, 2010, and December 31, 2021. RESULTS: 49 patients were included, of which 25 (51.02%) were women and 24 (48.98%) men, with a mean age of 29.57 years. Of these, 14 (28.57%) patients experienced some type of MKA failure. The most frequent complication that led to failure was periprosthetic infection, observed in seven (14.29%) patients. Variables associated with MKA failure included biopsies performed outside our hospital (HR 3.2, 95% CI 1.4-6.4, p = 0.02), the length of the long axis of the tumor (HR 2.1, 95% CI 1.2-4.6, p = 0.01) and a prolonged surgical time (HR 3.37, 95% CI 1.1-8.6, p = 0.04). CONCLUSION: the most significant prognostic factors associated with MKA failure in our cohort were tumor size, prolonged surgical time, and performance of the diagnostic biopsy in a center not specialized in the management of this type of patient. These findings highlight the importance of considering these variables to improve outcomes in patients undergoing MKA.

INTRODUCCIÓN: la reconstrucción de grandes defectos óseos mediante artroplastía modular de rodilla (AMR) representa un desafío significativo en términos de funcionalidad. El objetivo del presente trabajo fue identificar los diferentes factores pronósticos asociados al fracaso de la AMR en pacientes oncológicos. MATERIAL Y MÉTODOS: se realizó un estudio de cohorte retrospectiva, incluyendo pacientes con diagnóstico de tumor musculoesquelético en el fémur distal o la tibia proximal, que fueron sometidos a AMR entre el 1 de Enero de 2010 y el 31 de Diciembre de 2021. RESULTADOS: se incluyeron 49 pacientes, de los cuales 25 (51.02%) eran mujeres y 24 (48.98%) hombres, con una edad media de 29.57 años. De éstos, 14 (28.57%) pacientes experimentaron algún tipo de fracaso de la AMR. La complicación más frecuente que condicionó el fracaso fue la infección periprotésica, observada en siete (14.29%) pacientes. Las variables asociadas con el fracaso de las AMR incluyeron biopsias realizadas fuera de nuestro hospital (HR 3.2, IC95% 1.4-6.4, p = 0.02), longitud del eje mayor del tumor (HR 2.1, IC95% 1.2-4.6, p = 0.01) y tiempo quirúrgico prolongado (HR 3.37, IC95% 1.1-8.6, p = 0.04). CONCLUSIÓN: los factores pronósticos asociados al fracaso de las AMR en nuestra cohorte fueron el tamaño del tumor, un tiempo quirúrgico prolongado y la realización de la biopsia diagnóstica en un centro no especializado en el manejo de este tipo de pacientes. Estos hallazgos resaltan la importancia de considerar estas variables en pacientes sometidos a AMR.

Factors to improve odds of success following medial opening-wedge high tibial osteotomy: a machine learning analysis.

BACKGROUND: Although high tibial osteotomy (HTO) is an established treatment option for medial compartment osteoarthritis, predictive factors for HTO treatment success remain unclear. This study aimed to identify informative variables associated with HTO treatment success and to develop and internally validate machine learning algorithms to predict which patients will achieve HTO treatment success for medial compartmental osteoarthritis. METHODS: This study retrospectively reviewed patients who underwent medial opening-wedge HTO (MOWHTO) at our center between March 2010 and December 2015. The primary outcomes were a lack of conversion to total knee arthroplasty (TKA) and achievement of a minimal clinically important difference of improvement in the Knee Injury and Osteoarthritis Outcome Score (KOOS) at a minimum of five years postoperatively. Recursive feature selection was used to identify the combination of variables from an initial pool of 25 features that optimized model performance. Five machine learning algorithms (XGBoost, multilayer perception, support vector machine, elastic-net penalized logistic regression, and random forest) were trained using five-fold cross-validation three times and applied to an independent test set of patients. The performance of the model was evaluated by the area under the receiver operating characteristic curve (AUC). RESULTS: A total of 231 patients were included, and 200 patients (86.6%) achieved treatment success at the mean of 9 years of follow-up. A combination of seven variables optimized algorithm performance, and the following specific cutoffs increased the likelihood of MOWHTO treatment success: body mass index (BMI) ≤ 26.8 kg/m2, preoperative KOOS for pain ≤ 46.0, preoperative KOOS for quality of life ≤ 33.0, preoperative International Knee Documentation Committee score ≤ 42.0, preoperative Short-Form 36 questionnaire (SF-36) score > 42.25, three-month postoperative hip-knee-ankle angle > 1.0°, and three-month postoperative medial proximal tibial angle (MPTA) > 91.5° and ≤ 94.7°. The random forest model demonstrated the best performance (F1 score: 0.93; AUC: 0.81) and was transformed into an online application as an educational tool to demonstrate the capabilities of machine learning. CONCLUSIONS: The random forest machine learning algorithm best predicted MOWHTO treatment success. Patients with a lower BMI, poor clinical status, slight valgus overcorrection, and postoperative MPTA < 94.7 more frequently achieved a greater likelihood of treatment success. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

The use of vascularized fibula flap with allograft in post-oncologic microsurgical bone reconstruction of lower limbs in pediatric patients.

BACKGROUND: Post-oncologic surgical reconstruction of lower limbs in pediatrics remains a challenging topic. Microsurgical techniques allow reconstructions of large bony defects. The use of vascularized fibular flap with allograft has proven to be an ideal biologic construct. We aim to assess the success rate of this operation, including flap survival, bony union, weight-bearing ambulation, and complications in a long-term follow-up in our case series compared to the literature. PATIENTS AND METHODS: Our case-series includes 18 femoral resections (9 osteosarcomas, 8 Ewing sarcoma, and 1 desmoid tumor) and 15 tibial resections (10 osteosarcoma, 4 Ewing sarcoma, and 1 Malignant Fibrous Histiocytoma). We collected patients' demographics, type of tumor, type of resection, defect size, fibula-flap length, method of fixation, anastomosis site, follow-up data, complications, and their management. All survivals were examined by X-ray and CT-scan to evaluate the morphological changes of the vascularized fibula and follow-up. The functional evaluation was performed by the 30-point Musculoskeletal Tumor Society Rating Score (MSTS) for the lower limb (Enneking et al., Clinical Orthopaedics and Related Research 1993(286):241-246). RESULTS: The mean age of the femur resection patients' group was 11.2 years with a mean defect size of 14 cm and a mean length of the fibular flap of 18 cm; for the tibia the mean age was 12 years with a mean defect size of 14 cm and a mean length of the fibular flap of 16.6 cm. The overall survival of the reconstructions at 5 years follow-up was 17 out 18 cases for the femur and 13 out of 15 cases for the tibia. MSTS score was 28.2 for the femur and 23.7 for the tibia. The average time of union of the fibula was seen after 5 months, while allograft consolidation was observed around 19.7 months. The mean time of follow-up was 144.5 months for the femur and 139.2 months for the tibia. The complication rate observed was 7 out of 18 for the femur and 7 out of 15 for the tibia reconstructions. CONCLUSIONS: The viability of the fibula is a cornerstone in the success of reconstruction as well as the successful management of complications in intercalary defects after tumor resection in pediatrics to restore good functionality. Our results are in line with those reported in the literature in terms of overall complication rates. The high primary union of allograft, the high MSTS score obtained, and the low rate of severe complications reflect the mechanical role of this reconstructive technique over a long follow-up.

Autogenous structural bone graft reconstruction of ≥ 10-mm-deep uncontained medial proximal tibial defects in primary total knee arthroplasty.

BACKGROUND: Management of uncontained medial proximal tibial defects during primary total knee arthroplasty (TKA) can be challenging, especially for defects ≥ 10 mm in depth. This study sought to assess the outcomes of autogenous structural bone grafts to address these defects. MATERIALS AND METHODS: In this prospective study, patients with uncontained medial proximal tibial defects ≥ 10 mm in depth undergoing TKA were managed by autogenous structural bone grafts fixed by screws and were followed up for at least 36 months. Patients were followed-up clinically with Knee Society Score (KSS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Additionally, radiological follow-up was done to assess bone graft union and implant stability. RESULTS: The study included 48 patients with a mean age of 69.2 ± 4.5 years. The mean body mass index (BMI) was 31.4 ± 3.7 kg/m2. The mean defect depth was 17 ± 3.6 mm. With a mean follow-up period of 52.2 ± 12.3 months, the median KSS improved significantly from 30 preoperatively to 89, P < 0.001. The median WOMAC score reduced significantly from 85 preoperatively to 30.5, P < 0.001. The mean ROM increased significantly from 73 ± 12.4 preoperatively to 124 ± 8.4 degrees, P < 0.001. The mean graft union time was 4.9 ± 1 months. No significant complications were reported. CONCLUSIONS: Autogenous bone graft reconstruction is a safe and effective method of addressing uncontained medial proximal tibial defects in primary TKA. LEVEL OF EVIDENCE: Level IV.

The Biomechanical Investigation of Osseointegration Levels in Titanium Implants Simultaniously Placed with Different Bone Grafts.

BACKGROUND: Dental implant-supported prostheses have been scientifically accepted and have been a common treatment choice in the case reconstructing of partial or total tooth loss. In additon, bone grafts (alloplast, xsenograft, allograft) are frequently used in implant and sinus lift surgical procedures. AIM: The aim of this study is to investigate the bone-implant osseointegration levels of titanium implants simultaniously placed with different bone grafts. MATERIALS AND METHODS: In the study, 32 female S. Dawley rats were divided into four groups. In the control group (n = 8), turned surface implants with a 2.5 mm diameter and a 4 mm length were placed in the tibia of the rats without the use of a graft material. In the experimental groups, bone cavities were opened in the tibias of the rats and a synthetic (alloplast) graft (n = 8), human allograft (n = 8), and bovine xsenograft (n = 8) were placed simultaniously with a 2.5 mm diameter and a 4 mm length turned surface titanium implants. The cavities in the experimental groups were opened with a 4 mm diameter and a 5 mm length. After 8 weeks of recovery, all rats were sacrificed at the end of the experimental period. The implants and surrounding bone tissue were removed. The removed tissue was subjected to biomechanical analysis in order to evaluate bone-implant osseointegration and peri-implant new bone formation. The Kolmogorov-Smirnov test, Kruskal-Wallis test, and Mann-Whitney U-test were used in the study. Significance was evaluated at the P < 0.05 level. RESULTS: In the biomechanical analyses, it was determined that there was no statistically significant difference between the control group and the other three groups in which different graft materials were applied in terms of bone-implant osseointegration (P > 0.05). In other words, in the biomechanical analyses, no statistical difference was found between any of the groups. CONCLUSIONS: As a result of this study, it can be thought that different graft materials can be successfully used in peri-implant-guided bone regeneration and may be an alternative to autogenous grafts.

Increased symptoms of stiffness after opening-wedge high tibial osteotomy are associated with worse postoperative knee function outcomes and lower patient satisfaction rate.

BACKGROUND: Symptoms of knee stiffness after open wedge high tibial osteotomy (OW-HTO) can significantly affect surgical effectiveness, but no studies have reported risk factors for knee stiffness after OW-HTO. METHODS: Patients treated with OW-HTO for the first time between 2018 and 2021 were included. Data were collected on patient demographics, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Short Form (SF) 12 scores, hip-knee-ankle angle (HKA) and patient satisfaction before and after surgery. Patients with worse WOMAC stiffness scores at 1 year were defined as the 'increased stiffness' group and the other cohort as the 'non-stiffness' group. The primary outcome of the study was to compare postoperative knee function scores (WOMAC and SF-12), HKA and patient satisfaction rate between the two groups. The secondary outcome was the use of logistic regression to analyze independent predictors of increased postoperative stiffness symptoms. RESULTS: At 1 year postoperatively, 95 (11.3%) patients had a significant increase in stiffness. Patients had significantly (p < .001) less improvement in pain, function, and total WOMAC scores, and SF-12 score than those in the non-stiffness group (n = 745). However, the differences in WOMAC and SF-12 scores in increased stiffness group at 1 year post-operatively were statistically significant (p < .001) compared to the non-stiffness group. There was no statistically significant difference in HKA in the increased stiffness group (172.9° ± 2.3°) compared to non-stiffness group (173.4° ± 2.6°) at 1 year postoperatively (p = .068). Patient satisfaction was significantly lower in the increased stiffness group (p < .001). Logistic regression analysis showed that diabetes (odds ratio (OR) 1.809, p = .034) and preoperative WOMAC stiffness score of 44 or less (OR 4.255 p < .001) were predictors of increased stiffness. CONCLUSIONS: Patients with increased stiffness after OW-HTO had worse functional outcomes and lower patient satisfaction rates and patients at risk of being in this group should be informed pre-operatively.

[Research progress on pathological mechanism and clinical correlation between medial meniscus posterior root tear and tibial rotation].

Objective: To summarize the current research progress on the concept, clinical presentation, diagnosis, biomechanical changes, and pathological mechanisms of the medial meniscus posterior root tear (MMPRT), and its clinical correlations with tibial rotation. Methods: The research literature on MMPRT and its relationship with tibial rotation at home and abroad in recent years was extensively consulted and summarized. Results: MMPRT is a specific and common type of medial meniscus injury of the knee joint. The occurrence of posterior medial pumping pain events following low-energy trauma in patients provides important clues for the diagnosis of this injury, with MRI being the preferred imaging modality. The biomechanical effects generated by MMPRT are similar to those caused by total removal of the medial meniscus. And this injury is usually associated with tibial rotation. MMPRT induces pathological external rotation of the tibia, which can be restored by timely medial meniscus posterior root repair. Furthermore, changes in tibial rotation are related to the healing status after medial meniscus posterior root repair. Conclusion: MMPRT is closely related to tibial rotation. Understanding the biomechanics, pathological mechanisms, and clinical correlations between the two is of great significance for improving the diagnosis and treatment strategies.

A finite element model for investigating the influence of keel design and position on unicompartmental knee replacement cementless tibial component fixation.

OBJECTIVES: The cementless Oxford Unicompartmental Knee Replacement (OUKR) tibial component relies on an interference fit to achieve initial fixation. The behaviour at the implant-bone interface is not fully understood and hence modelling of implants using Finite Element (FE) software is challenging. With a goal of exploring alternative implant designs with lower fracture risk and adequate fixation, this study aims to investigate whether optimisation of FE model parameters could accurately reproduce experimental results of a pull-out test which assesses fixation. MATERIALS AND METHODS: Finite element models of implants with three methods of fixation (standard keel, small keel, and peg) in a bone analogue foam block were created, in which implants were modelled using an analytical rigid definition and the foam block was modelled as a homogenous linear isotropic material. The total interference and elastic slip were varied in these models and optimised by comparing simulated and experimental results of pull-out tests for two (standard and peg) implant geometries. Then the optimised interference and elastic slip were validated by comparing simulated and experimental data of a third (small keel) implant geometry. RESULTS: The optimisation of parameters established an interference of 0.16 mm and an elastic slip of 0.20 mm as most suitable for modelling the experimental force-displacement plots during pull-out. This combination of parameters accurately reproduced the experimental results of the small keel geometry. The maximum pull-out forces from the FE models were consistent with experimental data for each implant design. CONCLUSIONS: This study shows that experimental pull-out tests can be accurately modelled using adjusted interference values and non-linear friction and outlines a method for determining these parameters. This study demonstrates that complex problems in modelling implant behaviour can be addressed with relatively simple models. This can potentially lead to the development of implants with reduced risk of failure.

Accurate surgical posterior tibial slope alteration can be achieved in total knee arthroplasty regardless of surgeon skill level or local soft tissue thickness-A retrospective radiograph-based study.

PURPOSE: To retrospectively report on the impact of local soft tissue thickness and surgeon skill level on the accuracy of surgical posterior tibial slope (PTS) alteration achieved in patients undergoing total knee arthroplasty (TKA) utilising lateral knee radiographs. METHODS: Pre- and postoperative radiographs of 82 patients undergoing primary TKA using conventional mechanical alignment technique were measured by two observers and subjected to quality criteria for accurate measurement of the PTS. All patients underwent a standardised surgical approach for PTS alteration: cruciate-retaining (CR) cases with preoperative PTS ≤ 10° were set for reconstruction of the preoperative PTS. Cases indicated for posterior-stabilised (PS) design and/or with a preoperative PTS > 10° were set for 3° of postoperative PTS. Pretibial subcutaneous fat (PSF) and surgeon skill level were analysed for their predictive quality regarding the accuracy of surgical PTS alteration achieved. RESULTS: The overall mean postoperative PTS was significantly lower than the preoperative values (6.2°, SD 2.7 vs. 7.7°, SD 3.2; p = 0.002103). Neither local soft tissue thickness, namely PSF, nor surgeon skill level was found to be a predictor of the accuracy of surgical PTS alteration achieved. Among cases set for PTS reconstruction, 25.9% and 42.6% achieved a postoperative PTS within ±1° and ±2° of preoperative values, respectively. In patients with a PTS > 10° or those indicated for PS design, slope reduction was achieved with a mean postoperative PTS of 6.5°. Furthermore, 14.3% and 32.1% of cases were within ±1° and ±2° of 3, respectively. CONCLUSION: This study demonstrates that accurate surgical alteration of the PTS is possible in TKA regardless of local knee soft tissue thickness or surgeon skill level. This proves the clinical feasibility of both targeted reduction as well as reconstruction of the PTS in TKA. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

'One millimetre equals one degree' is a major source of inaccuracy in planning osteotomies around the knee for metaphyseal deformities compared to the digital planning.

PURPOSE: The objective of this study was to compare the accuracy of virtually performed osteotomies around the knee. The comparison was made between the Miniaci method (method 1), considered the gold standard planning, with the widely held dogma that one degree of correction required equates to one millimetre of opening/closing (method 2). METHODS: This retrospective cross-sectional study was conducted between December 2018 and September 2022 in patients aged at least 15 years with metaphyseal knee deformity. Osteotomy planning was performed in methods 1 and 2 utilising calibrated long-leg alignment X-rays in the frontal plane. In both methods, the desired correction was defined by the Fujisawa point. The error % in measurement (ratio method 1/method 2) and the difference in millimetres (method 1 - method 2) between the two methods were analysed. RESULTS: A total of 107 osteotomies with 27 (25.2%) distal femoral osteotomies, 54 (50.5%) proximal tibial osteotomies and 26 (24.3%) double-level osteotomies were performed virtually with a mean hip-knee-ankle angle of 176.4 ± 6.6. In distal femur osteotomy, the mean error % between methods 1 and 2 was 38.9 ± 16.7% and 22.4 ± 16.8% for the opening and closing groups, respectively. In proximal tibial osteotomies, the mean error % was 22.7 ± 15.6% and 9 ± 10.8% for the opening and closing groups, respectively. In double-level osteotomy, the mean error % of femur-based corrections was 34.9 ± 19% and 19.5 ± 21% for the opening and closing groups, respectively, and the mean error of the tibial-based corrections was 26.4 ± 12.1% for the opening group and 10.8 ± 10% for the closing group, respectively. CONCLUSION: Planning one millimeter per degree of desired correction for osteotomies around the knee in metaphyseal deformities is a major source of error when compared with digital planning using the Miniaci method. This was seen most frequently with osteotomies of the distal femur and all opening wedge osteotomies. LEVEL OF EVIDENCE: Level Ⅲ, retrospective cross-sectional study.