Search Results (79)

Background: Medial-compartment knee osteoarthritis (KOA) carries substantial disability and long-term cost. High tibial osteotomy (HTO) and unicompartmental knee arthroplasty (UKA) are key joint-preserving or joint-replacing options for selected patients, but their comparative economic ranking remains uncertain. Methods: This critical narrative review synthesized comparative economic evidence on HTO versus UKA for isolated medial-compartment KOA. PubMed and Web of Science were searched as primary sources for English-language studies published from 1 January 2000 to 15 January 2026, while Google Scholar and citation tracking were used supplementarily to identify potentially missed records. Eligible studies were direct economic evaluations or comparative cost/resource studies with clear decision relevance to the HTO–UKA choice. Burden and cost-of-illness studies were used for contextual framing only and were not included in the core comparative synthesis. Results: The direct evidence base was small and methodologically heterogeneous and was dominated by decision-analytic models that differed in perspective, time horizon, utility metric, and assumptions regarding reoperation, revision, and conversion to total knee arthroplasty (TKA). These structural differences largely explain why a U.S. lifetime societal model favored HTO, a UK age-stratified 10-year model produced age-dependent findings, and a recent Canadian public-payer model favored UKA. Observational studies suggest that UKA episode costs can fall substantially in outpatient or ambulatory pathways, whereas HTO costs may rise when reoperations and technique-specific resource use are explicitly captured. Conclusions: Current evidence does not support a context-free economic ranking of HTO and UKA. Because the available studies are heterogeneous and incremental utility differences are often small, the findings should be interpreted cautiously and as scenario-dependent rather than definitive. Future comparative analyses should use contemporary pathway data, transparent and standardized costing, and explicit downstream event definitions for both procedures. Full article

Background: High tibial osteotomy (HTO) is a joint-preserving alternative for patients with medial compartment knee osteoarthritis (KOA), although its use has declined in recent decades in favor of total knee arthroplasty (TKA). This study aimed to evaluate HTO outcomes in patients treated at a tertiary center over the past decade. Methods: We conducted a single-center, retrospective, observational cohort study of patients with medial femorotibial KOA and genu varum who underwent HTO. Failure was defined as conversion to TKA. A comparative analysis regarding HTO survival was conducted with preoperative variables and KOA stages in the follow-ups up to 5 years. Univariate and multivariate Cox regression models were built to assess their effect on HTO survival time. The Kaplan–Meier method was used to estimate overall and subgroup survival. Disease progression over time was evaluated with the Bhapkar test. In all cases, p < 0.05 was considered statistically significant. Results: HTO was successful in 74.6% of the 63 patients. Age was significantly higher in the failure group (p = 0.006), and each additional year increased the hazard of failure by 8% (95% CI, 1.01–1.16, p = 0.033), although this significance was lost in multivariate analysis (p = 0.104). Kaplan–Meier estimated survival was 76.7% at 5 years, with a median survival time of 10.1 years. KOA stage progression was significant 5 years after HTO (p < 0.001). Conclusions: HTO demonstrated 76.7% survival at 5 years, with radiographic KOA progression over time. The association between age and failure was not maintained after multivariable adjustment. Full article

Background: Revision anterior cruciate ligament reconstruction (ACLR) presents an increasing clinical challenge with higher failure rates than primary reconstruction. However, the evolving research landscape and clinical evidence regarding key biomechanical risk factors remain incompletely synthesized. Methods: A sequential dual methodological approach was applied. First, a bibliometric analysis of the Web of Science Core Collection was performed to map global research trends and identify emerging hotspots. Based on the identified hotspot, a PRISMA-compliant meta-analysis of studies retrieved from PubMed, Embase, the Cochrane Library, and Web of Science was subsequently conducted. Clinical and radiographic outcomes were synthesized using random-effects models in R. Results: The bibliometric analysis included 4213 publications and demonstrated exponential growth in revision ACLR research, identifying posterior tibial slope (PTS) as the dominant research hotspot. A meta-analysis of 11 studies involving 299 patients showed significant postoperative improvements in patient-reported outcomes and objective knee stability measures, along with a mean PTS reduction of 8.72° (95% CI 7.84–9.60; p < 0.001), while no significant change in patellar height was observed. The pooled return-to-sport rate was 74% (95% CI 64–82%), and the most common complications were symptomatic hardware and postoperative recurvatum. Conclusions: PTS has emerged as a key focus in revision ACLR research, and addressing this biomechanical factor may be associated with improved functional and radiographic outcomes. However, current evidence is mainly derived from retrospective studies, and further prospective research is needed to confirm long-term efficacy and refine surgical indications. Full article

Background and Objectives: Medial opening wedge high tibial osteotomy (OWHTO) requires careful management of medial soft-tissue tension to achieve effective decompression and maintain knee stability. While superficial medial collateral ligament (sMCL) release is commonly performed, the role of pes anserinus release remains unclear. This study investigated the effect of pes anserinus release on postoperative pain, clinical outcomes, and medial stability in patients undergoing OWHTO. Materials and Methods: A retrospective analysis was performed on 80 knees (80 patients) that underwent OWHTO between 2012 and 2017. Patients were divided into two groups: Group A (n = 38, sMCL release only) and Group B (n = 42, sMCL + pes anserinus release). Immediate postoperative pain was assessed using visual analog scale (VAS) scores and rescue analgesic use. Clinical outcomes were evaluated with Knee Society Scores (KSSs). Radiographic medial joint opening (MJO) was measured on valgus stress radiographs preoperatively and at one year postoperatively. Results: Group B demonstrated significantly lower VAS pain scores at postoperative days (PODs) 1, 3, 5, 7, and 14 (p < 0.05) and required fewer rescue analgesics (5.5 ± 2.1 vs. 7.6 ± 3.7; p < 0.05). Both groups achieved comparable KSS improvement and radiographic correction (postoperative mechanical femorotibial angle: 2.1° valgus vs. 2.5° valgus). No significant intergroup or intragroup differences were observed in MJO at one-year follow-up (p > 0.05). Conclusions: Combined release of the superficial medial collateral ligament and pes anserinus during medial opening wedge high tibial osteotomy significantly reduces early postoperative pain and improves short-term functional recovery without compromising medial stability or alignment correction, although no significant long-term differences in functional outcomes or radiographic alignment were observed. Full article

Background: Osteotomy around the knee (OAK) is a joint-preserving surgery for knee osteoarthritis, yet some patients experience suboptimal outcomes. Preoperative identification of high-risk patients remains challenging. This study aimed to develop a machine learning model to predict clinical outcomes after OAK using preoperative gait acceleration data from inertial measurement units (IMUs). Methods: This multicenter prospective study enrolled patients undergoing OAK. Preoperative gait was recorded using synchronized IMUs placed on the lumbar spine and tibia. Lumbar and tibial signals were used for gait-cycle segmentation, while wavelet-based time–frequency features were extracted from tibial acceleration only. Outcomes were defined by achievement of the minimal clinically important difference in ≥3 KOOS subscales at 2-year follow-up (Good vs. Poor). Continuous wavelet transform features (5–20 Hz) were summarized as mean and standard deviation across six stance subphases. A Random Undersampling Boost classifier was trained and evaluated using nested leave-one-subject-out cross-validation. A sensitivity analysis using logistic regression confirmed that the IMU-based prediction score was independently associated with outcome after adjustment for baseline KOOS (p = 0.047). Results: Of 67 enrolled patients, 37 were classified as Good and 30 as Poor outcome. For machine learning analysis, 1173 tibial acceleration gait-cycle waveforms were usable. The model achieved an AUC of 0.744 (95% CI, 0.610–0.860) using a median of 15 features (range, 5–25) with sensitivity of 0.69 and specificity of 0.72. The most informative predictors were the mean magnitude in the 5–8 Hz band during loading response (0–17%) and variability in the 5–8 Hz band during late stance (67–83%). No significant differences in baseline demographics or radiographic parameters were found between outcome groups. Conclusions: Preoperative IMU-derived gait acceleration features showed moderate-to-good discrimination between outcome groups and may support preoperative risk stratification and individualized perioperative management. Full article

Background: Traditional high-speed mechanical osteotomes cause substantial thermal and mechanical trauma, impairing bone healing. Erbium-doped yttrium-aluminum-garnet (Er:YAG) lasers, with water-mediated non-contact ablation, offer precise osteotomy potential with minimal collateral damage. This study demonstrated the feasibility of Er:YAG laser use for complex osteotomies and elucidated its multi-scale biological impacts on bone. Methods: A custom Er:YAG laser performed Z/arc-shaped osteotomies on fresh ovine bone (oscillating saw as control); paired rat tibial osteotomies; and compared laser vs. saw resection. Osteotomy surfaces were characterized by SEM/micro-CT; histological staining quantified thermal/mechanical damage. Bone marrow-derived mesenchymal stem cell (BMSC) adhesion, viability, and infiltration on cut surfaces were evaluated via LSCM. Result: In the ex vivo ovine model, the Er:YAG laser enabled precise execution of complex osteotomies (Z-shaped and arc-shaped), producing significantly narrower gaps than the oscillating saw (1.14 mm vs. 2.70 mm, p < 0.001) with high geometric fidelity and smooth surfaces free of burrs, micro-cracks, or debris. In the in vivo rat model, laser ablation simultaneously minimized both thermal and mechanical damage at the osteotomy interface: it reduced the thermal damage depth (154 vs. 592 µm, p < 0.001) and empty lacunae rate (16.8% vs. 41.8%, p < 0.001) while completely avoiding the mechanical damage zone (297 µm) induced by sawing. Furthermore, the laser-ablated surface established a highly bioactive interface, which significantly enhanced the adhesion (606 vs. 389 cells), viability (86.9% vs. 46.6%), and infiltration depth (196 vs. 75 µm) of bone marrow-derived mesenchymal stem cells (all p < 0.001). Conclusions: In conclusion, this proof-of-concept study demonstrates that the Er:YAG laser has the potential to enable precise bone resection while preserving microstructure. By establishing a pro-regenerative microenvironment, this technology shows promise as a biologically favorable alternative to conventional sawing, although further technical refinement and long-term validation are essential for its clinical translation. Full article

Objectives: Medial open-wedge high tibial osteotomy (MOWHTO) is a surgical procedure used to treat medial compartment osteoarthritis of the knee with varus deformity. The aim of this study was to examine whether a larger correction angle in medial open wedge high tibial osteotomy (MOWHTO) leads to greater changes in postoperative patellar height (PH) and posterior tibial slope (PTS). Methods: Data from 83 patients who underwent MOWHTO were retrospectively analyzed. Lower limb alignment was evaluated using the hip–knee–ankle angle (HKAA). The PH was assessed using the Insall–Salvati index (ISI), the Blackburne–Peel index (BPI), the Caton–Deschamps index (CDI), the modified Miura–Kawamura index (MKI), and the plateau–patella angle (PPA). The PTS was determined using the Moore–Harvey method. Results: The median correction of HKAA was 8°. A decrease in PH was observed in the majority of cases across all methods, with the highest frequency of postoperative patella infera detected using the MKI. PTS most frequently increased, with a median increase of 3°. A significant association between the magnitude of HKAA correction and patellar height in the overall cohort was observed only for the MKI, whereas in patients with an HKAA correction ≥ 10°, significant associations were found for both the MKI and CDI. No significant association was found between the magnitude of HKAA correction and changes in posterior tibial slope in the overall cohort, while a significant negative correlation was observed in patients with an HKAA correction ≥ 10°. Conclusions: Assessment using the MKI demonstrated greater sensitivity in detecting postoperative PH decrease, particularly in identifying patella infera. The magnitude of HKAA correction was significantly associated with greater changes in PTS and PH in patients with a coronal plane correction of ≥10°. Full article

Objectives: This study aimed to evaluate longitudinal changes in knee muscle strength following open wedge high tibial osteotomy (OWHTO) for medial compartment knee osteoarthritis with varus deformity, with particular emphasis on differences between the operated and non-operated knees. Methods: This retrospective study included 78 patients who underwent OWHTO. All patients followed a standardized rehabilitation protocol consisting of protected weight-bearing for six weeks, followed by closed kinetic chain exercises and subsequent open kinetic chain exercises from three months postoperatively. Isokinetic knee extension and flexion strength were assessed preoperatively and at 3, 6, and 12 months postoperatively using a Biodex System IV dynamometer at angular velocities of 60°/s and 180°/s. Absolute muscle strength values and inter-limb strength deficits were analyzed. Statistical analyses were performed using the Shapiro–Wilk, Friedman, and Wilcoxon signed-rank tests, with significance set at p ≤ 0.05. Results: At 60°/s, knee extensor and flexor strength deficits significantly increased after surgery, peaking at three months postoperatively, and gradually improved; however, deficits remained significantly greater than preoperative values at one year (p < 0.05). Similar trends were observed at 180°/s, although they did not reach statistical significance. These deficits were primarily attributable to reduced muscle strength in the operated knee, while strength in the non-operated knee remained unchanged throughout follow-up. Conclusions: Knee muscle strength in the operated limb markedly declined during the first three months following OWHTO, particularly in maximal power, and generally required more than six months to recover toward preoperative levels. These findings emphasize the importance of targeted postoperative rehabilitation strategies focusing on early muscle power recovery after OWHTO. Full article

Background and Objectives: While particulated costal hyaline cartilage allograft (PCHCA) combined with microdrilling demonstrates superior cartilage regeneration compared to microdrilling alone in high tibial osteotomy (HTO), the impact on early clinical recovery remains uncertain. The aim of this study is to compare early clinical outcomes (within 6 months) between microdrilling alone versus combined particulated costal hyaline cartilage allograft (PCHCA) with microdrilling in medial open-wedge high tibial osteotomy (MOWHTO) for medial compartment osteoarthritis, and to investigate age-related differences in treatment response. Materials and Methods: This prospective, dual-center, randomized controlled trial with blinded outcome assessment enrolled 64 patients (33 treatment and 31 control) undergoing MOWHTO with medial femoral condyle cartilage defects (ICRS III-IV, ≥200 mm²). The treatment group received PCHCA implantation combined with microdrilling, while the control group received microdrilling alone. Patients and outcome assessors were blinded to group allocation. Primary outcomes were KOOS-Pain and VAS scores at 12 and 24 weeks. Age-stratified analysis compared patients ≤ 60 years (n = 44) versus > 60 years (n = 20) Results: The treatment group showed significantly superior KOOS-Pain scores at 12 weeks (70.6 vs. 61.6, p = 0.014) and 24 weeks (82.9 vs. 71.5, p = 0.011), with corresponding VAS improvements (p = 0.010 and p = 0.004). Age-stratified analysis revealed patients ≤ 60 years achieved comparable outcomes regardless of treatment (p = 0.574), while patients > 60 years demonstrated significantly superior outcomes with PCHCA (KOOS-Pain improvement: 24.7 vs. 17.9 points, p = 0.012). BMI ≥ 26 kg/m² significantly predicted reduced odds of achieving MCID for both pain (OR 0.88, p = 0.028) and ADL (OR 0.80, p = 0.003). Conclusions: PCHCA combined with microdrilling provides superior early pain relief compared to microdrilling alone in MOWHTO, with effects most pronounced in patients > 60 years. Age-stratified treatment selection and BMI optimization should be considered to maximize outcomes. Full article

Background: This study evaluated time-dependent changes in anchor hole width (AHW) and their association with postoperative medial meniscus extrusion (MME) in patients undergoing open-wedge high tibial osteotomy (OWHTO) with medial meniscus posterior root tear (MMPRT) repair and meniscal centralization. Methods: Thirty knees treated with combined OWHTO and MMPRT repair using the centralization technique were retrospectively reviewed. MRI, CT, and second-look arthroscopy were performed preoperatively and postoperatively. AHW of the MMPRT anchor and two centralization anchors (midbody and midbody–posterior, M-anchor and MP-anchor) were measured on multiplanar reconstruction CT images at 1, 3, and 6 months, and 1 year, and their correlations with postoperative MME were analyzed. Results: AHW increased up to 3 months and gradually decreased with surrounding sclerosis by 1 year. The M-anchor showed significantly greater mediolateral (ML) expansion than the MP-anchor and demonstrated a moderate positive correlation between 1-year AHW and MME (r ≈ 0.5, p < 0.01). Second-look arthroscopy confirmed a 90% healing rate of the repaired root. Conclusions: Although OWHTO combined with MMPRT repair and centralization achieved favorable root healing, postoperative MME progression was not fully prevented. Time-dependent ML anchor hole expansion around the M-anchor may indicate persistent micromotion, elongation of the meniscotibial ligament, and degenerative stretch of the repaired meniscus following healing, suggesting that even after successful root healing, ML motion remains difficult to control, highlighting the need for biomechanically optimized fixation. Full article

Introduction: Medial compartment knee osteoarthritis (OA) is characterized by varus deformity. A medial open-wedge high tibial osteotomy (MOWHTO), frequently invoked in the treatment of this deformity, affects the knee as well as the ankle joints. This study aims to evaluate the radiological and clinical effects of a MOWHTO on the ankle joint. Materials and Methods: A retrospective analysis was conducted with data from 110 patients (mean age: 52 years; 74.5% female) who underwent a MOWHTO between 2020 and 2023. Radiographic assessments were conducted both preoperatively and one year after surgery using full-length weight-bearing radiographs. The measurements included several alignment parameters such as the hip–knee–ankle angle (HKA), medial proximal tibial angle (MPTA), joint line convergence angle (JLCA), lateral distal tibial angle (LDTA), and talar tilt. Clinical outcomes were assessed using the Lysholm knee score and the American Orthopedic Foot and Ankle Society (AOFAS) ankle score. Results: While changes in the LDTA demonstrated a small effect size (d = 0.225), moderate-to-large effect sizes were observed in key alignment parameters (MPTA (d = 0.838), the JLCA (d = 0.798), and talar tilt (d = 0.752)), all of which showed statistically significant differences indicative of a correction in the joint alignment of potential clinical significance. Median Lysholm and AOFAS scores at one year were 90 and 100, respectively, indicating favorable clinical outcomes. No significant difference in outcomes was observed based on the amount of correction. Conclusions: An MOWHTO not only restores knee alignment but also significantly improves ankle alignment in the coronal plane. These findings suggest that an MOWHTO is associated with the restoration of knee alignment and with improvements in ankle alignment in the coronal plane. Full article

Background/Objectives: Symptomatic hardware removal remains the most frequent cause of reoperation after tibial tubercle osteotomy (TTO), with removal rates reported as high as 49%. Headless compression screws have been proposed as a low-profile alternative to conventional screws to reduce hardware-related morbidity, yet no study has directly compared their use with headed screws in TTO for patellofemoral instability. This study aimed to compare complication rates and the frequency of hardware removal between headless and headed screw fixation in TTO. Methods: A retrospective review was conducted on 84 patients (94 knees) who underwent TTO between 2014 and 2024. Patients were divided into two groups based on the type of fixation used: headless screws (56 knees) and headed screws (38 knees). Demographic characteristics, perioperative variables, functional outcomes (Kujala, Lysholm, and Tegner scores), complications, and reoperation rates were compared with a minimum one-year follow-up. Results: No significant differences were found between the groups in terms of baseline demographic and clinical characteristics. Symptomatic implant removal occurred in 13.2% of the headed screw group and in none of the patients in the headless screw group (p = 0.001). Reoperation for any reason was significantly lower in the headless group (3.6% vs. 26.3%, p = 0.002). Functional outcomes were similar between groups. Post-hoc power analysis confirmed sufficient statistical power (98.8%) to detect differences in implant removal rates. Conclusion: Headless screw fixation in TTO was associated with significantly lower rates of hardware-related reoperations and painful implant removal, while achieving functional outcomes similar to those with headed screws. Headless screws may represent a preferable fixation method for reducing implant-related complications in TTO. Full article

Background: Medial-compartment knee osteoarthritis with varus alignment is treated surgically by realignment (high tibial osteotomy, HTO), resurfacing (unicompartmental knee arthroplasty, UKA), or proximal fibular osteotomy (PFO), which aims to indirectly unload the medial tibial plateau. Methods: We conducted a structured narrative review (PubMed/MEDLINE, Google Scholar; 2000–2025; last search 30 August 2025) of comparative clinical, biomechanical and safety data for HTO, UKA and PFO, including prior meta-analyses and mechanistic reports. One hundred fourteen studies met prespecified criteria. Results: HTO reliably corrects coronal alignment and unloads the medial compartment; long-term survivorship varies by selection and technique, and complications include hinge fracture, delayed/nonunion and hardware problems. UKA typically yields faster early pain relief and recovery in pooled analyses, with implant-specific failure risks and mid-term revision dependent on design and surgical experience. PFO cohorts consistently report early pain and function gains with plausible biomechanical rationale, but evidence is dominated by small, heterogeneous series with short follow-up and limited comparative data. Adjusted head-to-head comparisons generally favor UKA for early pain yet show HTO and UKA can achieve similar patient-reported improvements in selected younger cohorts; robust comparative trials including PFO are lacking. Conclusions: HTO and UKA are established, mechanistically distinct options best matched to patient age, alignment, activity goals, and comorbidity. PFO is a low-burden, promising alternative with uncertain durability; longer-term, controlled evaluation and registry surveillance are required before broad adoption. Findings should inform shared decision-making while acknowledging differences in evidence maturity. Full article

Purpose: This study aimed to quantitatively compare the resected bony wedge volume and evaluate discrepancies in the non-overlapping lateral osteotomy surface areas among four closed-wedge high tibial osteotomy (CWHTO) techniques. Materials and Methods: Eleven knees from 10 patients who underwent high tibial osteotomy at our hospital (2016–2023) were analyzed using preoperative three-dimensional computed tomography. Representative cases were selected based on sex, the presence of proximal tibia vara, and a high joint line convergence angle. A subgroup analysis was then conducted. Surgical simulations were performed on reconstructed bone models using four different CWHTO techniques (conventional, oblique, hybrid 2:1, and hybrid 3:1) at three target angles (12°, 15°, and 18°). Osteotomy surface area and bony wedge volume were calculated and compared. Results: Distal osteotomy surface areas for the oblique, hybrid 1, and hybrid 2 techniques were 91%, 83%, and 72% of the conventional technique, respectively. Resected bony wedge volumes were 86%, 52%, and 38% of the conventional technique, respectively. Volumes decreased in the order of conventional, oblique, hybrid 3:1, and hybrid 2:1. Hybrid techniques showed significantly smaller resection volumes than the conventional and oblique techniques. The non-overlapping lateral osteotomy surface areas for oblique, hybrid 1, and hybrid 2 were 41% (lateral), 22% (medial), and 22% (medial) of the conventional technique, respectively. Only the conventional technique showed a statistically significant difference. Conclusions: Hybrid CWHTO techniques resulted in less bony wedge resection and fewer non-overlapping osteotomy surfaces compared with conventional and oblique techniques. Hybrid CWHTO may offer potential advantages in bone stock preservation and reduced lateral overhanging area. Full article

Full-length radiography is essential for evaluating spinal deformities, limb length discrepancies, and preoperative planning in orthopedics, yet the measurement accuracy of different radiographic methods remains unclear. This phantom study compared the accuracy of rotational stitching, one-shot and slot-scanning full-length radiography across six radiographic systems in quantifying distances between anatomical landmarks. Measurement errors were statistically analyzed using appropriate nonparametric tests. The results demonstrated significant differences in measurement accuracy among the three methods (H (2) = 15.86, p < 0.001). Slot-scanning exhibited the highest accuracy, with a mean error of −1.19 ± 10.13 mm, while both rotational stitching and one-shot imaging showed greater systematic underestimation, with mean errors of −18.95 ± 13.77 mm and −15.32 ± 12.38 mm, respectively. These negative biases (approximately 1.9 cm and 1.5 cm) are clinically meaningful because, if unrecognized, they can alter mechanical axis estimation and alignment planning in procedures such as high tibial osteotomy (HTO). Post hoc analysis confirmed the superior accuracy of slot-scanning compared to the other two methods, while no significant difference was found between rotational stitching and one-shot imaging. These findings indicate that system choice substantially impacts measurement accuracy, supporting preferential use of slot-scanning when precise quantitative assessment is required. Full article