Intra-operative femoral condyle fractures during primary total knee arthroplasty: Incidence, risk patterns, and early outcomes in an Asian cohort.

Single-stage knee revision arthroplasty under special consideration of bony defects and soft tissue laxity over the full arc of motion. Aseptic loosening, ligamentous instability, or outlier in implant position requiring single-stage knee revision arthroplasty. Cases with severe bone loss or ligamentous instability requiring ahinged prosthesis. Loss of knee extensor function. After establishment of astandardized median parapatellar approach and setup of the imageless robotic system, the implant is mapped while still in situ. The bone-implant interface is highlighted in the 3D reconstruction of the implant by the application of special points during mapping. Soft tissue balance is registered and the component position of the revision implant is determined in the virtual implant planning stage. The implant is then removed and the surgical plan is executed with the robotic bur. If necessary, augments can be used to account for excessive bone loss and reconstruct the native joint line. Full weight-bearing as tolerated, free range of motion. In the literature, robotic-assisted knee revision arthroplasty has mainly been described in the form of case reports and smaller case series; the authors report generally favorable results.

PurposeMost contemporary total knee arthroplasty (TKA) designs aim to replicate native kinematics, yet the independent contribution of implant geometry to dynamic stability remains unclear when soft‐tissue balance is standardised. We compared medial‐pivot (MP) and posterior‐stabilised (PS) TKA implanted under a uniform medial‐tight balancing protocol and contrasted both with healthy knees.MethodsThirty‐six patients with medial osteoarthritis were randomised to MP (EVOLUTION®) or PS (Persona®) TKA. All procedures used a medial parapatellar approach, modified measured resection and calibrated medial‐tight balancing. At 1 year, knee injury and osteoarthritis outcome sore (KOOS) and knee society score (KSS) were recorded and three‐dimensional gait kinematics were assessed. Femoral anterior‐posterior translation (FAPT), femoral medial‐lateral translation (FMLT) and tibial rotation angle (TRA) were quantified using a projection‐based algorithm. A healthy reference cohort of 25 young adults (50 knees) completed the identical gait protocol.ResultsKOOS and KSS improved significantly in both TKA groups with no between‐group differences. Maximum stance‐phase FAPT (% body height) differed significantly among groups (analysis of variance [ANOVA] p < 0.01), with smaller excursions in MP TKA (0.8 ± 0.6) than PS TKA (1.9 ± 1.0) and healthy knees (1.9 ± 0.8). Maximum FMLT (% body height) also differed (ANOVA p < 0.01); MP TKA demonstrated smaller translations (0.9 ± 0.5) than PS TKA (2.4 ± 1.1), while PS TKA exhibited greater translations than healthy knees (1.3 ± 0.7). Maximum internal TRA (degrees) differed significantly (ANOVA p < 0.01); MP TKA showed greater internal rotation (4.1 ± 2.2) than PS TKA (2.8 ± 1.7), whereas both were reduced relative to healthy knees (12.0 ± 4.5).ConclusionWith identical medial‐tight balancing, implant geometry independently influenced gait kinematics. MP TKA exhibited the most constrained translational behaviour, whereas both TKA designs showed reduced tibial rotation relative to healthy knees despite similar clinical outcomes. These findings highlight the biomechanical trade‐off between reproducing native kinematics and adopting implant‐guided stability.Level of EvidenceLevel I, randomised controlled trial.

BackgroundTotal knee arthroplasty (TKA) is increasingly performed in older patients to manage severe osteoarthritis. Given the aging population, optimizing surgical techniques for this age group has become increasingly important. The surgical approach impacts postoperative outcomes, particularly in patients aged 75 years and over, who are prone to immobilization-related complications. This study compared the subvastus (SV) and medial parapatellar (MP) approaches, focusing on rehabilitation, early mobilization, and complications.Material/MethodsA retrospective trial included 60 patients aged over 75 years with stage IV osteoarthritis, undergoing TKA. Patients were divided into SV or MP approaches. Outcomes included time to straight leg raise (SLR), range of motion (ROM), pain (visual analog scale, VAS), length of hospital stay, and complications.ResultsThe SV group achieved earlier SLR (1.7 vs 3.4 days, P=0.001), better ROM at 1 week (94° vs 79°, P=0.008), lower VAS scores at day 3 (4.0 vs 6.0, P=0.02), and shorter hospital stay (5.0 vs 6.7 days, P=0.03). Blood loss was slightly higher in the SV group (360.5 vs 340.2 mL, P=0.76). Immobilization-related complications were lower in the SV group (3.3% vs 10%, P=0.24).ConclusionsThe SV approach enhanced early mobilization and rehabilitation in older patients, potentially reducing immobilization-related complications, despite slightly higher blood loss. These findings suggest that the subvastus approach may be preferable in geriatric patients to enhance recovery outcomes.

Total knee arthroplasty (TKA) is associated with acute postoperative effects that increase the risk of falls. These effects differ between the medial parapatellar (PP) and mid-vastus (MV) surgical techniques but have not been evaluated in terms of postural sway complexity. Loss of this complexity leads to increased randomness in the center of pressure and higher fall risk. This exploratory comparative analysis addresses this knowledge gap by examining how PP and MV techniques affect postural sway complexity in women. Twenty women with osteoarthritis (OA) were randomly assigned to TKA via the PP or MV approach. Postural sway data were collected at: 1 day before the surgery (Pre), 5 days (Post), 2 weeks, and 1 month post-surgery. We also included an age- and sex-matched healthy control group (n = 11) with a single assessment of their postural sway. The temporal structure of variability was evaluated in terms of its complexity. We quantified the complexity of postural sway using detrended fluctuation analysis (DFA) and multi-scale entropy (MSE). The α exponent (DFA) and MSE values showed significant effects of time in both axes, with both surgical groups exhibiting a shift towards more random patterns following TKA. When compared to controls, the PP group exhibited a significantly lower α exponent, indicative of more random patterns, at 2 weeks and 1 month but not at Pre and Post, while no such differences were observed for the MV group. Lower α exponent and higher MSE values reflect reduced sway complexity. These findings suggest that TKA leads to loss of complexity in women during the postoperative stage, with the PP approach resulting in more pronounced reductions relative to healthy controls than the MV approach. Future studies should explore the long-term effects of TKA on postural sway complexity and the impact of rehabilitation protocols. N/A.

Tibial intramedullary nailing (IMN) is the standard treatment for tibial shaft fractures, yet anterior knee pain (AKP) remains common, affecting nearly 47% of patients. Despite the reported advantages of suprapatellar techniques, infrapatellar approaches-medial parapatellar (MPP) and transpatellar (TP)-remain the most commonly used methods for tibial IMN. This systematic review and meta-analysis compares MPP and TP approaches regarding pain, AKP incidence, range of motion (ROM), knee function, and fracture healing. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, PubMed, Embase, Scopus, and Web of Science were searched up to November 2024. Randomized clinical trials (RCTs) and comparative observational studies in adults undergoing tibial IMN via MPP or TP approaches were included. Outcomes were AKP incidence, pain intensity, knee function, ROM, and union-related variables. Pooled mean differences (MDs) and risk ratios (RRs) were calculated using random-effects and common-effects models. Twelve cohort studies (782 patients) and 9 RCTs (462 patients) were included. Across cohort studies, MPP was associated with a significantly lower AKP risk at latest follow-up (RR = 0.76 [0.63; 0.90]) and at 6 months. Visual analog scale pain at 3-month postoperative also favored MPP (MD = -1.27 [-1.94; -0.60]) but did not reach the minimal clinically important difference. RCTs demonstrated similar trends toward lower pain and AKP with MPP, but without statistical significance. Functional outcomes and ROM generally favored MPP across both study designs, though findings were inconsistent and unsuitable for pooling. Fracture healing and union rates were comparable between approaches. The MPP approach for tibial IMN was linked to a lower incidence of AKP compared with the TP approach, while offering comparable or better functional outcomes, ROM, and pain intensity. These findings suggest MPP as the preferred infrapatellar approach in appropriate clinical settings. Nonetheless, high-quality studies with standardized outcome measures are essential to validate these findings. Level III (systematic review of RCTs and retrospective comparative studies). See Instructions for Authors for a complete description of levels of evidence.

Osteochondroma, though typically a tumor of younger individuals, should not be excluded from the differential diagnosis of knee pain in elderly patients. Symptomatic lesions, even in uncommon locations such as the infrapatellar region, can be effectively managed with surgical excision, leading to significant improvement in function and quality of life. This case report presents an atypical occurrence of an osteochondroma in a 65-year-old female, located in the infrapatellar region of the right knee. The patient experienced progressive knee pain and swelling, alongside mechanical symptoms such as locking and catching, which significantly impaired her mobility. Clinical examination revealed a firm, non-tender mass in the infrapatellar area, accompanied by mild joint effusion and restricted range of motion. Diagnostic imaging, including X-rays, MRI, and CT scans, confirmed an osteochondroma in the infrapatellar region, characterized by a pedunculated bony outgrowth with a 1.5 cm cartilaginous cap, with no signs suggesting malignant transformation. Due to the symptomatic nature and impact on the patient's quality of life, surgical excision was performed via a medial parapatellar approach, achieving complete removal of the lesion. The postoperative course was uneventful, with marked improvement in symptoms and restored knee function. This case highlights the importance of including osteochondroma in the differential diagnosis for knee pain in elderly patients and demonstrates the effectiveness of surgical intervention in managing symptomatic lesions in uncommon anatomical locations.

The learning curve refers to the relationship between a learner's execution of a task and the number of attempts or time necessary to perform it in a predictable, reliable, and optimal fashion. The learner's competence in a task should improve over time as they execute the job more frequently. The present investigation aims to clarify the learning curve associated with robotic-assisted total knee arthroplasty (TKA). Consecutive patients undergoing total knee arthroplasty at the Department of Orthopaedic Surgery, Eifelklinik St. Brigida, Simmerath, Germany, between 2021 and 2025 were prospectively screened for participation in this clinical study. All procedures were performed through a medial parapatellar approach, following a functional alignment strategy. Implantation was performed in accordance with the manufacturer's recommendations using the Smith & Nephew Legion Genesis II system with a posterior-stabilised polyethylene insert. Both femoral and tibial components were cemented with Palacos cement (Heraeus Medical GmbH, Wehrheim, Germany). Postoperative physiotherapy followed the standard institutional protocol. At hospital admission, demographic variables including age, body mass index (BMI), and sex were recorded. Operative time was documented for each procedure and defined as the interval from skin incision to completion of wound closure. The first 200 robotic-assisted TKAs were monitored. 66% (112 of 200 patients) were women, and 47.5% (95 of 200 TKAs) were performed on the right side. The mean age of the patients was 68.6 ± 8.1 years, and their BMI was 28.6 kg/m². The exponential decay model revealed a characteristic learning curve, characterised by initial rapid gains followed by a plateau. The estimated asymptotic operative time was approximately 89.2 minutes, with a learning rate coefficient of 0.035. This implies that the majority of efficiency improvements occur early, but meaningful reductions persist beyond the 20th case. Block-wise comparisons supported the existence of an earlier functional learning threshold. Statistically significant reductions in operative time, compared with the first 10 cases, were observed from the 41st to 50th procedure block (p = 0.02), with stabilisation in the 90-minute range thereafter. The most efficient gains occur early, and operative times stabilise at around 90 minutes after approximately 40 procedures. German Registry of Clinical Trials (ID DRKS00030614).

Knee osteoarthritis (OA) is a common cause of pain and disability in the elderly, for which total knee arthroplasty (TKA) is an effective treatment. The medial parapatellar approach is widely used but may impair patellar blood supply and delay quadriceps recovery. The subvastus (SV) approach has been introduced to preserve the extensor mechanism and potentially allow faster post-operative rehabilitation. This study compares the SV and medial parapatellar approaches in primary TKA, focusing on early recovery of quadriceps function. This study aims to evaluate and compare the SV and medial parapatellar approaches for total knee replacement (TKR) in patients with OA at a tertiary care center, focusing on the time required for post-operative recovery of quadriceps function. We conducted a retrospective review of medical records from 200 patients with OA who underwent TKR at a tertiary care hospital between January 2024 and December 2025. Patients were categorized into two groups: Group A underwent TKR using the SV approach, while Group B received TKR through the medial parapatellar approach. Pre-operative data, including quadriceps strength, body mass index, and baseline demographic characteristics, were collected from initial workup notes. Demographic data of all the patients were described in Table. Starting from the 1st post-operative day, the time to the first unassisted straight leg raise was recorded as the primary measure of quadriceps function. The collected data were then analyzed to assess post-operative quadriceps recovery. The SV approach was associated with faster recovery of quadriceps function compared to the medial parapatellar approach. Patients in their sixties experienced the most significant improvement. In addition, pre-operative quadriceps strength was found to play a key role in post-operative muscle recovery. The SV approach in TKA promotes faster early recovery, including quicker quadriceps function, less pain, earlier range of motion, and shorter hospital stays compared to the medial parapatellar approach. Long-term functional outcomes are similar between the two techniques. Although technically more demanding, the SV approach is a safe and effective option that enhances early rehabilitation.

Lateral unicompartmental knee arthroplasty through a medial parapatellar approach: surgical technique and mid-term results in 108 patients.

Introduction. Extraskeletal myxoid chondrosarcoma (EMC) is a rare soft-tissue sarcoma with a substantial risk of local recurrence and distant metastasis. Liquid-nitrogen cryosurgery may serve as an adjunct during limb-salvage procedures, including bone recycling. Objective. To report a juxta-articular EMC of the knee treated with wide excision, liquid-nitrogen cryosurgery of resected bone segments, and reconstruction with total knee replacement (TKR), and to present functional follow-up outcomes. Methods. A wide excision was performed via a medial parapatellar approach with osteotomy of the patella and proximal tibia. Resected bone was treated with liquid nitrogen (15 minutes) followed by stepwise thawing, then reattached; reconstruction included TKR and internal fixation. Follow-up assessed union, recurrence/metastasis (MRI/CT), and function (MSTS). Results. Surgical margins were negative. Union was achieved within 1 year. No local recurrence or progression of lung lesions was detected during 1–3 years of follow-up. Function was preserved (ROM 0–90°) with MSTS 90 % (1 year), 97 % (2 years), and 93 % (3 years), without reported complications. Conclusions. Cryosurgery with bone recycling can be a useful adjunct for limb-salvage surgery in knee EMC, enabling reconstruction with favorable functional outcomes in early to mid-term follow-up.

Total knee arthroplasty (TKA) in obese patients poses multiple challenges and there is a lack of consensus on various aspects of TKA in this patient population. This study is a modified Delphi consensus study of international experts to provide recommendations on TKA in obese patients. The consensus statements were generated using an anonymized two-round modified Delphi questionnaire, sent to an international panel of 53 knee surgeons, with an 80% agreement being set as the limit for consensus. The responses were analysed using descriptive statistics, with median as the measure of central tendency. Anonymized feedback was provided to all panellists based on responses from previous rounds to help generate the consensus. 9 statements reached a consensus: WHO classification (87%), BMI cut-off for single-stage bilateral TKA (92%), use of tibial stem (84%), medial parapatellar approach (92%), same surgical approach as non-obese TKA (92%), inherent malnutrition (82%), higher risk of aseptic loosening in BMI class 3 (81%), need for time interval between bilateral TKA (88%), and consensus against leaving the knee in slight flexion (82%). The panel was unable to reach a consensus on 17 statements. This indicates lack of consensus on a majority of issues among experts and further research is required in this field to address evidence gaps, so we can improve our management of this increasing cohort of patients undergoing TKA. The statements reaching consensus form an important set of recommendation to improve patient selection and outcomes. Level of evidence Level V.

Osteochondral allografting is a well-established, durable treatment option for focal patellar cartilage defects, particularly in young, active patients with symptomatic grade 3 and 4 lesions. Clinical outcomes show success rates of 77% to 87% when grafts are accurately placed and properly integrated. Precise cartilage-to-graft congruity is critical, as malalignment may lead to persistent pain, graft failure, or cartilage degeneration. Arthroscope-assisted techniques enhance visual accuracy, improving fit and load distribution while reducing the risk of prominent or unstable grafts. The procedure was indicated in a young female patient with a symptomatic grade 4 osteochondral defect of the patella that had failed nonoperative management. No concomitant realignment or osteotomy was required. Through a medial parapatellar approach, the patella was everted, and multiple full-thickness defects were identified on the medial and lateral facets. The degenerated cartilage was debrided, and the recipient sites were precisely measured and prepared (6-8 mm diameter, 8 mm depth). Using arthroscopic assistance, osteochondral plugs were harvested from the flattest portion of the donor condyle with careful axial alignment. Each graft was inserted under direct arthroscopic visualization, ensuring a flush, congruent surface with surrounding native cartilage. Multiple grafts were placed sequentially, guided by enhanced visualization to avoid prominence and optimize contour matching. Intraoperative assessment confirmed stable fixation and optimal surface congruence of all grafts. Arthroscopic visualization enabled correction of subtle irregularities that may not be palpable through open techniques. Rehabilitation was initiated early to prevent arthrofibrosis, with partial weightbearing maintained for 4 weeks, followed by a progressive recovery program emphasizing mobility, strength, and endurance. Arthroscope-assisted patellar osteochondral grafting provides enhanced accuracy in graft placement and alignment, potentially improving integration and long-term outcomes. This technique is particularly valuable for achieving flush, congruent reconstruction in patients with isolated patellar chondral lesions. Early mobilization and structured rehabilitation are essential for optimizing functional recovery and reducing the risk of complications, such as stiffness, pain, or poor graft incorporation. The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

BackgroundTrochlea-only arthroplasty (TOA) is a conservative surgical approach for isolated patellofemoral arthritis, aimed at preserving the native patella and avoiding complications associated with its resurfacing. This study evaluates the mid-term survivorship, functional outcomes, and revision profile of patients undergoing TOA and compares outcomes with historical data from conventional patellofemoral arthroplasty (PFA).MethodsWe retrospectively reviewed 50 patients who underwent isolated TOA between 2008 and 2019 by a single surgeon. A medial parapatellar approach was used, with intraoperative assessment of the joint. The decision to retain the native patella was made irrespective of the extent of arthritis in the patella. All patients underwent patelloplasty and circum-patellar neurectomy without resurfacing. Implant survival was evaluated using Kaplan-Meier analysis, and factors influencing revision were assessed using Cox proportional hazards modelling. Patient-reported outcomes were collected using the Kujala score in a subset of patients with unrevised implants.ResultsThe overall implant survivorship was 82% at a mean follow-up of 9.2 years. Nine (18%) patients required revision, most commonly due to progression of tibiofemoral arthritis. Revisions included patellar resurfacing, staged medial unicompartmental knee replacement, and conversion to total knee arthroplasty. Age and sex were not significant predictors of revision. The mean Kujala score in 13 (32%) unrevised patients was 56.1, with no reports of instability or significant flexion deficits. No patients with known revisions were contacted for patient-reported outcomes.ConclusionTOA is a viable joint-preserving surgical option for selected patients with isolated patellofemoral arthritis. It avoids the complications associated with patellar resurfacing and maintains satisfactory mid-term survivorship comparable to published literature. TOA may serve as a procedural bridge between conservative management and full PFA, allowing for a stepwise and anatomically conservative approach. Further prospective studies are warranted to validate these findings.

Total knee arthroplasty (TKA) is a widely used surgical intervention for advanced osteoarthritis, with evolving surgical techniques aiming to reduce blood loss and hospital stay. The minimally invasive midvastus (MMV) approach is hypothesized to minimize soft tissue damage and promote faster recovery compared to the classic medial parapatellar (MPP) approach. This study aimed to compare clinical and radiological outcomes, including perioperative blood loss and hospital discharge timing, between the MMV and MPP approaches.A total of 99 patients with advanced osteoarthritis who underwent primary TKA between 2013 and 2019 were prospectively analyzed. Patients were divided into MMV (n = 50) and MPP (n = 49) groups. All surgeries were performed by the same experienced surgeon using the same prosthetic system and perioperative protocols. Clinical outcomes included hemoglobin (Hb), hematocrit (Hct), discharge timing, range of motion (ROM), Visual Analog Scale (VAS), and Oxford Knee Score (OKS). Radiological outcomes included alignment and component positioning. Statistical analysis was conducted with significance set at p < 0.05.There were no significant differences between groups in demographic characteristics, surgical duration, alignment parameters (mechanical medial proximal tibial angle, mechanical lateral distal femoral angle, component tibial angle, component femoral angle), VAS, OKS, or final ROM. Postoperative (day 0 and day 3) Hb and Hct values did not differ significantly, and no blood transfusions were required in either group. However, same-day discharge was significantly more common in the MMV group (p = 0.02). One wound complication occurred in the MPP group; one patient from each group required postoperative manipulation under anesthesia.While both surgical approaches provided comparable clinical and radiological outcomes with no differences in blood loss, the MMV approach was associated with a higher rate of same-day discharge, suggesting an advantage in early recovery and reduced hospital stay.

To compare the effectiveness of the infrapatellar approach versus the semi-extended parapatellar approach for intramedullary nailing in the treatment of type A tibial shaft fractures. A retrospective analysis was conducted on 66 patients with type A tibial shaft fractures treated with intramedullary nailing between May 2018 and February 2023. Among them, 23 patients underwent the infrapatellar approach (group A), 22 the semi-extended lateral parapatellar approach (group B), and 21 the semi-extended medial parapatellar approach (group C). There was no significant difference among the three groups in baseline data ( P>0.05), including gender, age, cause of injury, time from injury to surgery, presence of concomitant fibular fractures, AO/Orthopaedic Trauma Association (AO/OTA) classification, and preoperative visual analogue scale (VAS) score for pain. The operation time, intraoperative blood loss, incision length, intraoperative fluoroscopy frequency, length of hospital stay, fracture healing time, knee range of motion (ROM) at 12 months postoperatively, Lysholm knee score at last follow-up, incidence of postoperative anterior knee pain, and incidence of postoperative skin numbness around the knee were recorded and compared. VAS scores were also evaluated preoperatively and at 4, 8, and 12 weeks postoperatively. All patients completed the surgery successfully, with primary incision healing in all cases and no incision infections. There was no significant difference among the three groups in intraoperative blood loss or length of hospital stay ( P>0.05). The operation time was significantly shorter in group B compared to groups A and C ( P<0.05), and incision length was significantly shorter in groups A and B compared to group C ( P<0.05). The intraoperative fluoroscopy frequency, from least to most, was group B, group C, and group A, with significant differences ( P<0.05). All patients were followed up 12-24 months, with no delayed union or nonunion. There was no significant difference among the three groups in fracture healing time ( P>0.05). At 12 months postoperatively, knee ROM and incidence of postoperative skin numbness around the knee were comparable among groups ( P>0.05). Groups B and C showed significantly lower incidence of postoperative anterior knee pain during follow-up and higher Lysholm scores at last follow-up than group A ( P<0.05). VAS scores decreased gradually over time in all groups, with significant differences among all time points ( P<0.05). At 4, 8, and 12 weeks postoperatively, VAS scores in groups B and C were significantly lower than those in group A ( P<0.05). Compared with the infrapatellar approach, the semi-extended parapatellar approach offers more accurate nail placement, easier fracture reduction, fewer intraoperative fluoroscopies, better late knee function, and fewer complications in the treatment of type A tibial shaft fractures. Among parapatellar approaches, the lateral approach demonstrates greater clinical advantages, with shorter operation time, fewer fluoroscopies, lower incidence of skin numbness around the knee, and suitability for patients with soft tissue contusions.

This study aimed to compare the clinical and functional outcomes of modified V-Y quadricepsplasty with those of medial parapatellar (MP) arthrotomy in the context of revision total knee arthroplasty (rTKA). It is hypothesized that there is no significant difference in clinical, radiological, and strength outcomes between V-Y quadricepsplasty and the medial parapatellar approach. A retrospective comparative cohort study was conducted on 31 patients (19 who underwent an MP arthrotomy and 12 who underwent a modified V-Y quadricepsplasty) who had undergone rTKA. The clinical outcomes included knee range of motion (ROM), muscle strength, and functional scores (HSS, LEFS, WOMAC). Radiographic evaluations were conducted to assess mechanical axis deviation (MAD) and patellar height. Both groups were comparable in demographics. Clinical outcomes, including active ROM (89.5° ± 22.2° vs. 89.4° ± 8.9°; p = 0.985), extension deficit (0.41° ± 1.44° vs. 4.7° ± 7.5°; p = 0.061), flexion (93.7° ± 24.4° vs. 106.3° ± 16.7°; p = 0.099), and functional scores (HSS: 82.6 ± 12.1 vs. 85.8 ± 9.2, p = 0.408; LEFS: 43.4 ± 11.8 vs. 45.2 ± 12.2, p = 0.691; WOMAC: 24.3 ± 12.9 vs. 20.7 ± 17.3, p = 0.543) were similar between groups. Strength measurements showed no significant differences in peak extension (38.3 ± 16.8 Nm vs. 39.3 ± 12.9 Nm; p= 0.848) and peak flexion torque (22.6 ± 6.7 Nm vs. 24.8 ± 6.8 Nm; p = 0.392). Radiographic assessments showed no significant differences in MAD (15.4 ± 19.5 mm vs. 15.8 ± 13.6 mm; p = 0.951) and patellar height (1.1 ± 0.14 vs. 1.14 ± 0.25; p = 0.669). No complications were observed. Modified V-Y quadricepsplasty offers outcomes comparable to MP arthrotomy in rTKA, with the advantage of extended exposure for complex cases without compromising recovery.However, given the limited sample size and the exploratory nature of this study, these findings should not be interpreted as evidence of equivalence between the two approaches. Level IV, Retrospective cohort.

This quasi-randomized controlled trial compared robotic-assisted and conventional total knee arthroplasty (TKA) in restoring patient-specific coronal alignment according to a functional alignment philosophy. Outcomes included preservation of the anatomical hip-knee-ankle angle (aHKA), mechanical axis deviation (MAD), and component positioning. Subgroup analyses assessed consistency in valgus and varus morphotypes. A single-blind parallel group quasi-RCT was conducted at the Department of Orthopedic Surgery, Eifelklinik St. Brigida, Germany (2021-2025). Patients underwent TKA following identical perioperative pathways. All procedures used a medial parapatellar approach and Smith & Nephew Legion Genesis II implants. A total of 692 patients were enrolled (346robotic, 346freehand). Baseline characteristics were comparable. Postoperative HKA was similar between groups, but the robotic group achieved a significantly smaller aHKA delta (2.58° vs 4.49°, p = 0.002). Robotic-assisted TKA preserved joint line alignment more consistently in valgus (2.63° vs 5.72°, p = 0.03) and varus knees (2.56° vs 4.22°, p = 0.004). The MAD control was improved, while differences n the mechanical lateral distal femoral angle (mLDFA) and mechanical medial proximal tibial angle (mMPTA) were not significant. Robotic-assisted TKA enhanced accuracy in reproducing native joint line orientation, offering more consistent preservation of joint line obliquity in both valgus and varus morphotypes, thus supporting its role in personalized alignment strategies.

Periprosthetic distal femur fractures have grown in volume because the rate of primary total knee arthroplasty (TKA) has increased. These injuries are increasingly treated with intramedullary nailing (IMN), but knee instability after retrograde IMN has not been well studied. A cadaveric study was performed to investigate TKA balance after retrograde femoral IMN. The main hypothesis was that retrograde femoral IMN preparation would lead to increased flexion space laxity. A medial parapatellar approach and measured resection TKA technique were performed in 8 cadaveric knees. A tensioner was used to measure the flexion and extension spaces in millimeters and the anterior-to-posterior (AP) translation of the knee at various times. Flexion and extension gaps were measured at a constant 50 Newton-meters both with and without a femoral trial component in place. A tibial trial component was not placed to have a flat surface to reference. Owing to the size of the tensioner, the extension gap could only be measured without a femoral component in place. All knees were then closed, underwent opening reaming for a retrograde femoral nail (rIMN) under fluoroscopy, and then reopened to assess flexion and extension spaces and AP translation. A tibial component was intentionally not implanted to isolate the effect of femoral TKA preparation on rIMN placement and its subsequent impact on the flexion gap and AP stability of the knee. Differences were measured between the pre- and post-rIMN gaps and calculated as the post-rIMN gap minus the pre-rIMN gap. Simple descriptive statistics were performed, including mean and SD. Differences between the pre- and post-IMN measurements were assessed with paired students t tests. Without a femoral component and compared with the pre-IMN space, the post-IMN flexion space was greater by 1.5 ± 1.2 mm ( P = 0.01), the post-IMN extension space was not different at 0 ± 0.53 mm ( P = 0.60), and the post-IMN AP translation was greater by 3.13 ± 2.3 mm ( P = 0.01). With a femoral component and compared with the pre-IMN space, the post-IMN flexion space was not different at 0.13 ± 0.64 mm ( P = 0.60). After TKA femoral preparation, retrograde IMN did not significantly affect the flexion gap when a femoral component was in place. Without a femoral component in place, the extension gap was unchanged after IMN placement. Although the flexion gap was statistically greater after IMN placement when measured without a femoral component, the clinical relevance is questionable given this difference was, on average, only 1.5 mm greater and a femoral component was not present. Similarly, the differences in AP translation observed without a femoral component were attenuated once the component was in place, which may have been further attenuated if a tibial component was able to be placed. These findings suggest limited clinical impact of retrograde IMN of the knee in the context of modern TKA femoral preparation.

Combined medial parapatellar and lateral approaches in management of type C III distal femur fractures “A prospective case series study”