Double Decker anterior cruciate ligament avulsion.

Distal anterior cruciate ligament avulsion from tibial side is an unusual injury. It can be either bony avulsion, which is more common, or rarely a soft tissue peeling of tibial spine with no bone injury. This case report represents a very infrequent injury of combined soft tissue peeling of distal anterior cruciate ligament along with bony avulsion of tibial spine in a 12-years-old boy after falling from his bike.

Comparative study of two different access points, one tibial vein and the popliteal vein, for catheter-directed thrombolysis in the treatment of acute mixed lower extremity deep vein thrombosis 1.

BACKGROUND: Although the popliteal vein approach is commonly used for catheter-directed thrombolysis (CDT) treatment in patients with acute lower extremity deep vein thrombosis (DVT), CDT via a new access route, the posterior tibial vein, is also used and has demonstrated good results. However, this tibial approach has not been tested in large samples. OBJECTIVE: To compare the early efficacy of CDT using the tibial and popliteal vein approaches for the treatment of acute mixed lower extremity DVT. METHODS: In this retrospective cohort study, 87 patients with acute mixed lower extremity DVT treated at the Department of Interventional Medicine of Zhuhai People's Hospital were enrolled; those with tibial vein access and popliteal vein access were included in the observation (n = 55) and control (n = 32) groups, respectively. The safety and efficacy of CDT via tibial vein access were investigated by collecting and comparing indicators such as venous patency, thrombus removal effect, thigh and calf circumference difference, swelling reduction rate of the affected limb, surgical complications, and post-discharge complication rate of the patients in the two groups. RESULTS: The postoperative thrombus clearance effect of the observation group was significantly better than that of the control group (P < 0.05), and the postoperative venous patency rate of the observation group was 83.2 ± 15.7%, which was higher than that of the control group (62.2 ± 38.2%) (P = 0.005). The swelling reduction rate of the lower extremity was 74.0 ± 33.8% in the observation group and 51.4 ± 30.0% in the control group, with a statistically significant difference (P = 0.002). However, there was no statistically significant difference (P > 0.05) in the rates of thigh swelling reduction, bleeding-related complications, or postoperative complications between the two groups of patients. CONCLUSIONS: CDT via the tibial vein approach is safe, effective, and may be a better approach for CDT access, offering superior thrombus clearance, venous patency, and lower extremity swelling reduction postoperatively.

The influence of tibial length on radiographic posterior tibial slope measurement: How much tibia do we need?

PURPOSE: The purpose of this study was to determine whether significant differences exist when comparing posterior tibial slope (PTS) measured using increasing lengths of the tibia to determine the anatomical axis. METHODS: Patients with full-length weight-bearing tibial radiographs were retrospectively identified from 2014 to 2022 at a single institution. Patients were excluded if there was any previous history of lower extremity fracture or osteotomy. The anatomical axis of the tibia was determined using the full length of tibial radiographs, and the "reference PTS" was measured using this axis. Using the same radiograph, the PTS was measured using four different anatomical axes at standardized tibial lengths. While the center of the proximal circle remained constant at 5-cm below the tibial plateau, the center of the distal circle was drawn at four points: a) overlapping circles; b) 10-cm distal to the tibial plateau; c) 15-cm distal to the tibial plateau; d) half the length of the tibia, measured from the tibial plateau to the tibial plafond. Bivariate correlation and frequency distribution analysis (measurements >2-degrees from reference PTS) were performed between the reference PTS and PTS measured at each of the four other lengths. RESULTS: A total of 154 patients (39.8 ± 17.4 years old, 44.2% male) were included in the final analysis. Measurements at each of the four tibial lengths were all significantly different from the reference PTS (p < 0.001). The correlation strength improved with increasing tibial length (overlapping: R = 0.681, 10-cm: R = 0.821, 15-cm: R = 0.937, and half-tibia: R = 0.963). The number of PTS measurements >2-degree absolute difference from the reference PTS decreased with increasing tibial length (overlapping: 40.3%, 10-cm: 24.0%, 15-cm: 26.0%, and half-tibia: 18.8%). CONCLUSION: Assessment of PTS is dependent on the length of the tibia utilized to obtain the anatomical axis. Accuracy and precision of PTS measurements improved with increasing length of tibia used to determine the anatomical axis. STUDY DESIGN: Case series.

Arthroscopic debridement and antibiotic-loaded cement for treatment of chronic infected tibial tunnel post-ACL reconstruction: A case report.

INTRODUCTION AND IMPORTANCE: Chronic extra-articular infections of the tibial tunnel are rare, and there are only a few cases reported in the literature, so the diagnosis and management of these infections are still unclear. CASE PRESENTATION: We report a 36-year-old patient with chronic infection of the tibial tunnel after ACL reconstruction surgery. The patient was treated with arthroscopic debridement of the tibial tunnel and antibiotic cement filling. Seven months postoperative, there were no signs of infection at the surgical site and the knee joint. The patient has no pain, no joint instability, no limitation of range of motion, and no limitation in daily activities. CLINICAL DISCUSSION: The definitive diagnosis of chronic infection of the tibial tunnel should be carefully based on clinical signs, blood tests, and imaging to rule out combined intra-articular infections. The arthroscopic technique can be a favorable method to control and debride the inflammatory tissue of the tibial tunnel, limiting the recurrence rate postoperatively. CONCLUSION: Arthroscopic debridement and antibiotic-loaded cement can be considered an alternative to traditional surgical methods in the treatment of chronic infection of the tibial bone tunnel after ACL reconstruction. LEVEL OF EVIDENCE: A case report.

Effects of Preoperative Abnormality of Posterior Tibial Tendon on the Surgical Outcomes of Medial Osteochondral Lesion of the Talus.

BACKGROUND: Although surgical treatment for osteochondral lesion of the talus (OLT) can obtain good clinical outcomes, the rate of return to sports is variable. It is reported that medial OLT unrelated to trauma has abnormal structures in the medial aspect, which may induce the medial OLT due to the medial instability. The posterior tibial tendon (PTT) plays an important role in the stabilization of the foot, and high mechanical stress may be added to the PTT to compensate for medial instability in medial OLT. We investigated whether abnormal PTT findings on preoperative magnetic resonance imaging (MRI) in patients with OLT affect clinical outcomes after surgery.  Methods: Eighty-one ankles in 74 patients who were treated surgically for OLT were included in this study (41 men and 33 women; mean age, 26.0 years). Abnormalities of the PTT were evaluated using preoperative MRI. The Japanese Society for Surgery of the Foot (JSSF) scale, arch height, and ankle activity score (AAS) on standing plain radiogram were compared between patients with and those without preoperative PTT abnormalities. RESULTS: Twenty-five ankles (30.9%) had PTT abnormalities on preoperative MRI. All patients with preoperative PTT abnormalities were medial OLT. There were no significant differences in the preoperative JSSF scale in the procedures for OLT. The postoperative JSSF scale and arch height were significantly lower in patients with preoperative PTT abnormalities than those without them. AAS in patients with preoperative abnormalities significantly decreased at the final follow-up.  Conclusion: PTT abnormalities on preoperative MRI may affect clinical outcomes even in preoperative asymptomatic patients in the medial OLT unrelated to trauma.

[Fractures around the knee in children : Epiphysiolysis and physeal fractures of the distal femur and proximal tibia]. / Frakturen rund um das Knie im Wachstumsalter : Epiphysiolysen und epiphysäre Frakturen des distalen Femurs und der proximalen Tibia.

Epiphysiolysis and epiphyseal fractures of the distal femur and proximal tibia are an extremely rare entity, but due to their far-reaching consequences with associated functional restrictions of the knee joint, they must be recognized and treated thoroughly. Complete and correct diagnosis is essential and, diagnostically speaking and in addition to standard x­rays in two planes, the threshold for cross-sectional imaging examination techniques should be low. A conservative treatment attempt is possible for undisplaced fractures, but surgical retention and stabilization using wires and screws is usually indicated. Growth disorders often and inevitably occur after such injuries. Clinical monitoring of complications only ends once growth is complete.

High Tibial Osteotomy with Posterior Medial Meniscal Root Reconstruction Yields Improved Radiographic and Functional Outcomes and Healing Rates Compared to Osteotomy Alone.

PURPOSE: To compare pre- and post-operative clinical and radiological outcomes between patients undergoing high tibial osteotomy (HTO) with medial meniscus posterior root tear (MMPRT) reconstruction using gracilis tendon graft versus those without reconstruction MMPRT. METHODS: Patients with MMPRT who underwent HTO between January 2018 and December 2021 with minimum 2-year follow-up were included. All the patients were divided into 2 groups based on whether underwent meniscus root reconstruction with tendon graft, HTO alone (33 cases) and HTO with reconstruction MMPRT (21 cases). Clinical evaluation included Lysholm score, international knee documentation committee (IKDC) score, and visual analogue scale (VAS) score. The functional recovery and radiologically outcome of the knee were evaluated preoperatively and at the latest follow-up. Meniscus root healing rates and medial meniscal extrusion (MME) according to the second MRI were compared between the two groups at the latest follow-up. RESULTS: The results showed a statistically significant improvement in the postoperative Lysholm score, IKDC score, and VAS score in both groups at the latest follow-up (P<0.001). The analysis of Minimal Clinically Important Difference (MCID) for postoperative outcomes revealed that the percentage of patients who reached MCID thresholds was 100% for Lysholm, 100% for IKDC, and 100% for VAS in the HTO with reconstruction MMPRT group. In comparison, the percentages were 87.9% for Lysholm, 90.9% for IKDC, and 100% for VAS in the HTO alone group. Additionally, compared with the HTO alone group, the HTO with medial meniscus posterior root reconstruction using gracilis tendon graft significantly improved the meniscus root healing rates (Complete healing 85.7% vs. 45.4%, 95%CI: 0.003-0.007, P=0.001) and functional recovery (P<0.005 ) at the final follow-up. Additionally, the HTO with reconstruction MMPRT had a significantly better change in K-L grade (improved knees K-L grade: 10/21 vs. 6/33, P=0.033) and MME (2.1±1.0mm vs. 3.1±1.6mm, 95%CI: 0.3-1.7, P=0.007) compared to the HTO alone group. CONCLUSIONS: HTO with reconstruction of the meniscal root using a tendon graft resulted in improved radiographic and patient-reported outcomes as well as improved healing rates compared to the HTO alone.

A rare variation in popliteal artery branching: anterior tibial artery and fibular artery from the common tibiofibular trunk.

The popliteal artery is a continuation of the femoral artery and is the main arterial supply to the lower leg and foot. Variation in the branching of the popliteal artery typically occurs proximal or distal to where the vessel crosses the popliteus muscle. In the case of a routine dissection of a 92-year-old female cadaver, a variation of the popliteal artery was found where the branches are a posterior tibial artery and a common tibiofibular trunk. It is important to recognize the vascular variations that exist in the popliteal fossa to prevent any unforeseen complications during surgeries or procedures to the knee or lower leg.

Association of tibial slope alterations with anterior cruciate ligament (ACL) injury and mucoid degeneration.

OBJECTIVE: To compare radiographic measurements of lateral tibial slope (LTS), medial TS (MTS), and coronal TS (CTS) in MRI-defined intact, injured, and mucoid-degenerated native ACL knees and determine inter-reader reliability. MATERIALS AND METHODS: Patient records from 2 years at tertiary care hospitals were reviewed for individuals aged 18-100 undergoing 3-Tesla knee MRI and radiographs. Two randomly selected cohorts, control, and pathologic ACLs on MRI with 86 patients each, were age, gender, and BMI-matched. A fellowship-trained musculoskeletal radiologist reevaluated curated images, characterizing ACL status. Two trained medical students independently collected clinical data and measured slopes on blinded radiographs. ICC, Cohen's kappa, and case-control matching were performed using SPSS statistical package, with ICC and ANOVA used for comparisons. RESULTS: Among 172 patients with 172 MRIs and radiographs, there were 86 controls and 86 ACL lesions. There were 108/172 (62.79%) males and 64/172 (37.21%) females. ICCs were 0.966 for MTS, 0.975 for LTS, and 0.978 for CTS. Mucoid degeneration patients had a higher BMI and were older than control (p < .05) or completely torn (p < .001) ACL patients. There was no difference in TS between normal and pathologic ACLs; however, LTS-MTS differences were larger with partial tears (2.5 ± 4.9) than normal ACLs by 4.5° (± 1.2, p < .001), complete tears by 4.5° (± 1.3, p < .001), and mucoid degeneration by 4.9° (± 1.5, p = .001). CONCLUSION: Various TS measurements are reliable. LTS-MTS differences are associated with different ACL lesions compared to normal ACLs.

Effects of three-dimensional femur and tibia postures on the parameters of standing long-leg radiographs for osteoarthritic knees in elderly female subjects.

BACKGROUND: Long-leg frontal radiographs of the lower extremities are used to assess knee osteoarthritis. Given the three-dimensional (3D) nature of alignment changes in osteoarthritis, postural alterations in the femur and tibia extend beyond the coronal plane (in-plane) to include the transverse and sagittal planes (out-of-plane). This study investigates the impact of these out-of-plane factors on in-plane knee alignment parameters observed in frontal radiographs. METHODS: A total of 97 osteoarthritic knees in women were examined. Using a 3D-to-two-dimensional (2D) image matching technique, we evaluated the 3D postures of the femur and tibia in the standing position as viewed from frontal radiographs in the world coordinate system. Statistical analyses were conducted to explore associations between these 3D postures and 2D alignment parameters obtained from frontal radiographs under identical conditions. FINDINGS: The femur exhibited a medial inclination of 2.7°, a posterior inclination of 3.9°, and an internal rotation of 4.2°, whereas the tibia showed a lateral inclination of 6.4°, an anterior inclination of 6.7°, and an internal rotation of 6.7°. Both coronal and rotational postures of femur and tibia influenced the hip-knee-ankle angle, mechanical axis percentage, and medial proximal tibial angle. However, only coronal factors of tibia impacted tibial joint line obliquity relative to the floor. INTERPRETATION: Attention should be paid to the potential impact of the out-of-plane postures of the femur and tibia on parameters assessed in plain frontal radiographs of the lower extremities.

Schatzker IV tibial plateau fractures: are they always unicondylar?

Objective: The objectives of this study were to describe the incidence and morphology of medial tibial plateau fractures that extend into the lateral articular surface and to describe trends in their management. Design: Retrospective. Setting: Level I Urban Trauma Center. Patients: Seventy consecutive patients sustaining OTA/AO 41 B1 and B3 fractures. Intervention: Open reduction internal fixation of medial tibial plateau fractures. Main Outcome Measurements: Incidence of medial tibial plateau fractures that extend into the lateral articular surface. Secondary outcomes include localization of lateral articular surface depression, neurovascular injury, and trends in surgical management. Results: Seventy patients were included with 9 fractures (12.9%) isolated to the medial condyle (MC) and 61 fractures (87.1%) extending to the lateral condyle (LC). Compartment syndrome was present in 2 patients (2.9%), peroneal nerve palsy in 2 (2.9%), and arterial injury in 1 (1.4%). Initial external fixation was used more frequently in the LC group compared with the MC group (P = 0.028). Of the 61 fractures in the LC group, 49 (80.3%) included lateral articular surface depression which localized to the posteromedial quadrant of the lateral articular surface in 36 of 49 fractures (73.5%). Lateral articular surface depression depth ≥10.6 mm was associated with the use of dual incisions (P < 0.001). Conclusions: Schatzker IV fractures frequently extend to the lateral condyle and often present with depression of the posteromedial lateral articular surface. Fractures with lateral articular surface depression depth ≥10.6 mm were more likely to undergo fixation with dual incisions. Level of Evidence: Therapeutic level IV.

Intramedullary nailing in a tibial shaft fracture distal to a total knee prosthesis with compromised soft tissue condition.

Case: We present a case report on the management and outcome of a periprosthetic tibial shaft fracture treated with intramedullary nailing. The patient, a 78-year-old female, presented with a history of having undergone total knee arthroplasty ten years ago due to osteoarthritis. She sustained a periprosthetic fracture of the tibial shaft with compromised soft tissues surrounding the fracture site following a motor vehicle accident. Plain radiographs revealed a displaced tibial shaft fracture with a flipped large spiral wedge fragment located distal to the total knee prosthesis. Due to the poor soft tissue condition and the risk of complications in wound healing, as well as the desire to avoid prolonged bed rest and immobilization, intramedullary nailing was chosen as the primary treatment modality. Despite the challenging circumstances, the patient achieved satisfactory healing and recovered her pre-injury ambulation status with no significant complications at the six-month follow-up. Conclusion: Managing periprosthetic tibial shaft fractures in the presence of compromised soft tissues presents significant challenges for orthopedic surgeons. In this case, intramedullary nailing proved to be a suitable treatment option, minimizing soft tissue trauma and providing stable fixation to facilitate early mobilization and weight bearing.

Three predictive scores compared in a retrospective multicenter study of nonunion tibial shaft fracture.

BACKGROUND: Delayed union, malunion, and nonunion are serious complications in the healing of fractures. Predicting the risk of nonunion before or after surgery is challenging. AIM: To compare the most prevalent predictive scores of nonunion used in clinical practice to determine the most accurate score for predicting nonunion. METHODS: We collected data from patients with tibial shaft fractures undergoing surgery from January 2016 to December 2020 in three different trauma hospitals. In this retrospective multicenter study, we considered only fractures treated with intramedullary nailing. We calculated the tibia FRACTure prediction healING days (FRACTING) score, Nonunion Risk Determination score, and Leeds-Genoa Nonunion Index (LEG-NUI) score at the time of definitive fixation. RESULTS: Of the 130 patients enrolled, 89 (68.4%) healed within 9 months and were classified as union. The remaining patients (n = 41, 31.5%) healed after more than 9 months or underwent other surgical procedures and were classified as nonunion. After calculation of the three scores, LEG-NUI and FRACTING were the most accurate at predicting healing. CONCLUSION: LEG-NUI and FRACTING showed the best performances by accurately predicting union and nonunion.

Assessing the Effectiveness of Modified Tibial Plateau Leveling Osteotomy Plates for Treating Cranial Cruciate Ligament Rupture and Medial Patellar Luxation in Small-Breed Dogs.

In small-breed dogs with concurrent cranial cruciate ligament rupture (CCLR) and medial patellar luxation (MPL), correcting both disorders is are essential for restoring normal gait. However, the previously described surgical treatment, using two osteotomy technique, poses a high risk of fracture and instability. Addressing CCLR and MPL with a single osteotomy and implant was considered superior to the conventional method. Therefore, a pre-contoured modified tibial plateau leveling osteotomy (PCM-TPLO) plate facilitating medial shifting of the proximal tibia was developed. We compared postoperative alignment and strength between this novel plate group and a conventional tibial plateau leveling osteotomy (TPLO) plate group using eight small-breed dog cadavers each. Additionally, we investigated the potential of the novel plate as an alternative to tibial tuberosity transposition. Postoperative alignment and strength were assessed through radiographs and mechanical testing. Measurements including tibial plateau angle, mechanical medial proximal tibial angle, and number of screws within the joint were also analyzed. There were no significant differences in all measured parameters. For the novel plate, the medial displacement ratio of the proximal tibia was confirmed to be approximately 30%, and the result was thought to be appropriate. These findings suggest that the PCM-TPLO plate could be a promising alternative for treating concurrent CCLR and MPL in small-breed dogs.

Evaluation of the effect of vascularized fibula graft harvesting on coronal plane alignment and functional outcomes of the lower limb.

Recent studies on fibular osteotomy for varus gonarthrosis and possible subsequent biomechanical changes have attracted increasing attention to the topic. Existing studies have focused mainly on proximal fibular osteotomy with short follow-up periods. The aim of this study was to investigate changes in the alignment of the coronal plane of the ankle and knee joints in patients who underwent vascularized fibula graft harvest (VFGH). The evaluation was based on functional outcomes and radiological measurements.In the comparison between the VFGH side and the contralateral side, no significant differences in the knee inclination (KI) or talar inclination (TI) angle, knee medial clear space (K-MCS) or ankle medial clear space (A-MCS) distance were noted. However, a significant difference in the hip knee (HKA) angle was observed between the operated and nonoperated sides (0.3° ± 1.8° and 1.5° ± 1.9°, respectively [p = 0.019]). Statistically significant differences in both the knee society score (KSS) and the AOFAS scores were found between the ipsilateral donor limb and the contralateral healthy limb. Although the contralateral healthy side had better clinical scores than the VFGH side, the outcomes of the VFGH side were still satisfactory or excellent.

Efficacy of tibial cortex transverse transport in treating diabetic foot ulcer and its effect on serum omentin-1 and irisin levels.

OBJECTIVE: Diabetic foot ulcer (DFU) is a common and debilitating complication of diabetes that is associated with an increased risk of lower-limb amputation and a reduced life expectancy. Tibial cortex transverse transport (TTT) has become a newly alternative surgical method to facilitate ulcer healing and prevent lower limb amputation. Herein, we investigated the efficacy of TTT in treating DFU and changes of serum omentin-1 and irisin levels. METHODS: This study prospectively recruited 52 consecutive patients with DFU who were treated with TTT. The follow-up was performed weekly during the first 12 weeks postoperatively and every 3 months until 1 year after TTT. The serum levels of vascular endothelial growth factor (VEGF), omentin-1, and irisin in DFU patients undergoing TTT were determined by ELISA methods on the preoperative 1st day, postoperative 2nd week and 4th week. RESULTS: The wound healing rate was 92.3% (48/52) at the 1-year follow-up. The visual analog scale (VAS) pain scores of patients showed a significant reduction at the 4th week after TTT (p < 0.001). The dorsal foot skin temperature, ankle brachial index, and dorsal foot blood flow of patients were significantly increased at the 4th week after TTT (p < 0.001). Results of ELISA methods showed the serum levels of VEGF, omentin-1, and irisin on the 2nd week and 4th week after TTT were notably elevated compared to the levels determined on the preoperative 1st day (p < 0.001). The serum levels of VEGF, omentin-1, and irisin on the 4th week after TTT were also significantly higher than the levels determined on the 2nd week after TTT (p < 0.001). CONCLUSION: TTT could promote the wound healing and reduce the risk of lower limb amputation, demonstrating promising clinical benefits in the treatment of DFU. Increased expressions of serum proangiogenic factors including VEGF, omentin-1, and irisin were noted in the early stage after TTT, which may provide a new mechanism of TTT promoting wound heal.

The modified suture-bridge technique for treating avulsion fracture of minors tibial eminence of anterior cruciate ligament: a retrospective study.

PURPOSE: This study aimed to evaluate the clinical and radiological outcomes of modified suture-bridge technique fixation for anterior cruciate ligament (ACL) tibial avulsion fracture. METHOD: Minors who underwent arthroscopic reduction and modified suture bridge fixation of ACL tibial avulsion fracture between January 2018 and January 2022 were retrospectively analyzed. Postoperative MRI and X-ray examinations were performed to evaluate the presence of epiphyseal plate injury and fracture healing. Moreover, KT-1000 side-to-side difference, Lachman test, range of motion (ROM), the subjective Knee score of the International Knee Documentation Committee (IKDC), Lysholm Knee score, and Tegner activity grade score were evaluated preoperatively and at the minimum 1-year follow-up visit. RESULTS: A total of 16 participants met the inclusion criteria. They had a mean age of 12.6 years (range, 9-16 years); mean time to surgery, 6.9 days (range, 2-13 days) and had a minimum of 12 months clinical follow-up (mean, 25.4 months; range, 12-36 months) after surgery. Postoperative radiographs and MRI showed no injury to the epiphyseal plate, optimal reduction immediately after the operation, and bone union within three months in all patients. All of the following showed significant improvements (pre- vs. postoperatively): mean KT-1000 side-to-side difference (8.6 vs. 1.5; p < 0.05), Lachman tests (2 grade 9 and 3 grade 7 vs. 0 grade 12 and 1 grade 4; p < 0.05), IKDC subjective score (48.3 vs. 95.0; p < 0.05), mean Lysholm score (53.9 vs. 92.2; p < 0.05), mean Tegner activity score (3.2 vs. 8.3; p < 0.05) and mean ROM (42.9°vs 133.1°; p < 0.05). CONCLUSION: Arthroscopic reduction and modified suture bridge fixation for ACL tibial avulsion fracture is a dependable and recommended treatment that can effectively restore the stability and function of the knee and is worthy of clinical promotion.

Influence of different standing positions on anatomical parameters of coronal whole-leg weight-bearing radiographs in preoperative planning for high tibial osteotomy.

Purpose: The purpose of this study was to assess the differences in lower limb global alignment and anatomical parameters of coronal whole-leg radiographs, which were generally used in preoperative planning for high tibial osteotomy (HTO), according to different weight-bearing standing positions. Methods: Between April 2021 and December 2022, 176 patients (60 males and 116 females) were investigated. Full-weight-bearing coronal whole-leg radiographs were obtained with the patella centred on the femoral condyle. Patients were divided by Kellgren-Lawrence grade (KL-0, KL-I, KL-II and KL-III) and assessed in two standing positions: legs closed and legs spread. Patients with flexion contractures or those unable to stand with full weight bearing were excluded. The mechanical distal femoral angle, medial proximal tibial angle (MPTA), femorotibial angle, joint line convergence angle, percentage weight-bearing line (%WBL) and hip-knee-ankle angle (HKAA) were measured. The Student's t test was used to compare the two standing positions. A p value < 0.05 indicated a statistically significant difference. Results: The MPTAs of legs closed standing and legs spread standing were 84.9 ± 2.6° and 85.1 ± 2.4° in KL-0, 84.7 ± 2.0° and 84.9 ± 2.1° in KL-I and 85.0 ± 2.43° and 85.4 ± 2.4° in KL-II, respectively. There were statistically significant differences in the MPTA between the two standing positions in KL-0, KL-I and KL-II. In contrast, the %WBL and HKAA did not change regardless of the standing position. In the KL-III group, no statistical significance was observed for any of the anatomical parameters. Conclusion: Several anatomical parameters were changed between the legs closed standing and the legs spread standing positions. It was suggested that the standing position should be taken into consideration in the planning for HTO. Level of Evidence: Level IV, Case series with no comparison group.

Required force for distraction during medial opening wedge high tibial osteotomy may serve as a predictive indicator for lateral hinge fracture.

Introduction: Medial open wedge high tibial osteotomy is a biological procedure for treating unicompartmental knee osteoarthritis. The literature repeatedly highlights the significance of preserving an intact lateral hinge during this procedure. We investigated the temporal course of distraction forces during distraction at the osteotomy site, aiming to quantitatively measure and analyse temporal changes in distraction forces at different distraction points for intact and fractured lateral hinges. Materials and Methods: This biomechanical study was conducted on 10 human cadavers, which were divided into two groups: one with preserved 1 cm intact lateral cortexes (ILCs) and the other with completely osteotomised fractured lateral cortexes (FLCs). An experimental setup was custom designed to facilitate the required force measurement during distraction. The distraction forces were recorded with a force gauge at 0.5-mm intervals throughout the distraction. Results: There was a significant difference between the ILC and FLC groups in distraction forces at all points (8-15 mm). The ILC group consistently exhibited higher distraction force values, with FLC recording values ranging from 8.8% to 13.2% of ILC's. Lateral hinge fractures caused an 86.7% reduction in the initial required force for distraction, significantly impacting the force required for distraction. The ILC group displayed a linear increase in the required distraction force up to 12.5 mm of distraction, which reached 3.7 times the initial value at 12.5 mm of distraction. The FLC group had lower baseline required distraction forces, following a relatively linear trend with more limited increases. Conclusion: FLCs in medial opening wedge osteotomy are associated with significant reductions in the force required for distraction, and a sudden decrease in distraction force during distraction may indicate a lateral hinge fracture. Force measurement devices for use during distraction could offer valuable insights and provide surgeons with immediate warnings for LHFs. Level of Evidence: Level IV.