Journal of Experimental Orthopaedics最新文献

The incidence of anterior cruciate ligament (ACL) injuries in paediatric and skeletally immature patients is rising, proportionally to the worldwide spread of sport participation. However, differently from adults, injuries in young patients pose serious challenges regarding their management, especially when surgery is required. To date, controversies remain regarding the indications, timing of surgery and techniques for ACL reconstruction. This current concept provides a deep and detailed theoretical background of ACL injury and management in patients with open physis. Moreover, a practical algorithm of treatment is provided based on authors' experience and research and current evidence-based medicine (EBM). To optimise management and reduce the risks of either conservative or surgical treatment, a deep knowledge of the specific concepts related to paediatric patients is required.

Level of Evidence

Level V.

While distinct in incidence and presentation, both talus and calcaneus fractures share a common challenge in their complex anatomy and high-energy mechanisms resulting in difficulties in treatment. With traditional open reduction and internal fixation (ORIF), these fractures carry a high risk of complications, such as avascular necrosis, infection and post-traumatic arthritis. New minimally invasive strategies have risen to the forefront, with arthroscopic-assisted reduction and internal fixation (ARIF) emerging as a promising alternative. This technique offers the potential for enhanced visualisation, reduced soft-tissue disruption, quicker recover and greater reduction advantage. The purpose of this narrative review was to discuss outcomes and surgical techniques of arthroscopic-assisted reduction and internal fixation (ARIF) of talus and calcaneus fractures. ARIF techniques varied in patient positioning, portal use and fixation strategies, but consistently emphasised anatomic reduction via microscopic visualisation typically with temporary Kirshner wires, followed by fixation with cannulated screws. Despite the technical learning curve, the use of ARIF demonstrated clear advantages in minimising soft-tissue trauma and enhancing joint preservation in both talus and calcaneus fractures. This review supports the growing role of minimally invasive techniques as a viable alternative to ORIF in patients with high-energy talus and calcaneus fractures.

Level of Evidence

Level IV.

Hip arthroscopy (HAS) research employs a wide range of patient-reported outcome measures (PROMs). This heterogeneity complicates cross-study comparisons and meta-analyses, as no gold-standard PROM exists. The minimal clinically important difference (MCID) offers a clinically meaningful threshold of change, but methodological guidance on integrating heterogeneous PROMs through MCID has been lacking. Can heterogeneous PROMs in HAS be harmonized through MCID normalization? PROMs reported in 100 HAS studies were identified and ranked according to frequency of use. The most frequently reported MCID values from published validation studies were applied. Each PROM was then evaluated and normalized by dividing observed mean values and standard deviations by the respective MCID, thereby yielding a standardized metric expressed in ‘MCID units’. A proof-of-concept data set with seven simulated two-arm studies was created to demonstrate the stepwise process of PROM prioritization, MCID-based normalization and subsequent synthesis through random-effects meta-analysis using the restricted maximum likelihood (REML) estimator. Across the 100 included studies, 214 PROM mentions were identified, with modified Harris Hip Score (mHHS) (33.2%), International Hip Outcome Tool—12 items (iHOT-12) (16.4%) and Hip Outcome Score—Sports Subscale (HOS-SSS) (15.4%) being the most frequent. Normalization successfully transformed heterogeneous PROMs into a unified outcome scale, enabling synthesis of results as ‘number of clinically meaningful improvements’. The framework preserved clinical interpretability and allowed transparent, reproducible pooling of outcomes. A proof-of-concept data set of seven simulated studies illustrated stepwise MCID-based normalization and synthesis through random-effects meta-analysis (REML). MCID normalization may offer a robust and clinically relevant methodology to harmonize diverse PROMs in HAS research. Its application may enhance comparability, reduce bias in evidence synthesis and support meaningful interpretation of meta-analytic findings. Importantly, it translates heterogeneous PROMs into a unified, clinically interpretable metric, thereby helping clinicians and researchers to better assess treatment effectiveness across studies. This approach could also be adapted to other surgical fields with fragmented outcome reporting.

Level of Evidence

Level V, expert opinion.

Purpose

This study aimed to evaluate the time-dependent changes in the medial and lateral subchondral bone density distribution of the tibial joint surface before and after high tibial osteotomy (HTO) using computed tomography-osteoabsorptiometry.

Methods

This study included 17 patients (20 knees) (8 men and 9 women; mean age: 55 years) who underwent HTO for medial compartment osteoarthritis. Computed tomography-osteoabsorptiometry was conducted to measure the subchondral bone density distribution in the tibial joint surface. The high-density area (HDA), defined as the region corresponding to the highest Hounsfield unit values that comprises 20% of the total region, was calculated. Medial ratio was defined as the proportion of the HDA in the medial compartment relative to the total HDA of both compartments. Measurements were performed preoperatively and at 3, 6, 12 and 24 months post-operatively, and a generalized linear regression analysis with a gamma distribution model was conducted.

Results

The medial ratios (mean ± standard deviation) were 89 ± 9% preoperatively, 73 ± 12% at 3 months, 78 ± 13% at 6 months, 78 ± 10% at 12 months and 77 ± 17% at 24 months. Based on the gamma distribution, the non-linear model was expressed as follows: Y = 82.8 × t^−0.04 × exp(−0.004 × t). This finding indicated that the medial ratio had a decreasing trend, reaching its minimum at 10.2 months post-operatively.

Conclusion

This study showed time-dependent changes in the subchondral bone density on the tibial side after HTO. The changes in the bone density distribution on the medial and lateral tibial joint surface, which are associated with alignment correction, stabilized at approximately 10.5 months post-operatively. Therefore, the optimal timing for evaluating subchondral bone density in response to stress redistribution may be after 10.2 months.

Level of Evidence

Level IV.

Purpose

Chronic ankle instability (CAI) is a common condition characterized by recurrent episodes of lateral instability, often due to a lesion of the ankle collateral lateral ligament complex. If untreated, CAI can lead to persistent symptoms and long-term degenerative changes. Arthroscopic ‘all-inside’ repair has gained traction as a minimally invasive technique offering functional and clinical benefits.

Methods

This retrospective study analyzed 43 patients undergoing arthroscopic ligament repair using the all-inside technique between 2021 and 2024. Functional outcomes were evaluated preoperatively (T0), post-rehabilitation (T1), and at the final follow-up (T2) using the Foot and Ankle Ability Measure (FAAM) score, VAS, and satisfaction ratings. Complications occurred were recorded during the follow up. Subgroup analyses investigated the influence of BMI, anchor use, and preoperative functional scores on outcomes.

Results

Patients demonstrated significant improvement in FAAM scores (T0: 71%, T2: 95%) and pain reduction (VAS: T0: 7.67, T2: 1.00). Two-anchor repairs yielded superior outcomes compared to single-anchor procedures (p = 0.01). While higher BMI was associated with poorer outcomes (p = 0.04), internal bracing improved functional scores in this subgroup. Preoperative FAAM scores did not predict postoperative outcomes (p = 0.21).

Conclusion

All-inside arthroscopic ligament repair is a safe and effective option for CAI, providing rapid recovery, low complication rates, and excellent patient satisfaction.

Level of Evidence

Level IV.

Purpose

Knee pain is a common reason for consulting an orthopaedic surgeon. It has a wide variety of aetiology, of which one is hip pathology. This phenomenon is called referred knee pain. While it is well-known, it has not been thoroughly described from the perspective of the knee surgeon. With this observational study, the importance of routinely including clinical examination of the hip during knee examination is highlighted.

Methods

A retrospective analysis was performed of all patients with knee pain who consulted the orthopaedic service for the first time during a period of 1 year. Both self-referred patients and those referred by other physicians were included. A full anamnesis and physical examination of the knee and hip were conducted. If hip pathology was suspected, a referral was made to a hip surgeon. Treatment was provided accordingly. A subjective improvement in pain or, when available, a ≥50% reduction in visual analogue scale score was considered a positive diagnosis of ‘referred knee pain’.

Results

Of the 1000 patients presenting for first-time consultation, 185 (18.5%) were referred to hip specialists for further assessment. Among the referred patients, 157 (84.9%) were found to have hip pathology, while 27 (14.6%) exhibited a combined hip and knee pathology. The most prevalent diagnoses included femoroacetabular impingement (22.9%) and osteoarthritis (58%). The predominant treatment modalities consisted of total hip arthroplasty (7.8%), physiotherapy (29.9%), and corticosteroid injections (54.1%). Referred knee pain was diagnosed in 137 (13.7%) of the cohort, with a higher prevalence in females (15.2% vs. 11.8% in males; p = 0.03).

Conclusion

With 13.7% of knee pain patients presenting with an underlying hip pathology, referred knee pain is a common and often overlooked phenomenon in the daily practice of a full-time knee surgeon. A complete history and physical examination including the hip is obligatory for every knee exam.

Level of Evidence

Level III, retrospective observational cohort study.

Purpose

In this study, we aimed to identify the direct insertion of the tibial attachment of the posterior cruciate ligament (PCL) using histological examination and evaluate its anatomical relationship with the medial meniscus (MM).

Methods

Twenty-one formalin-fixed cadaveric knees were examined. The PCL tibial attachment was analysed in sagittal (slices 1, 2 and 3) and coronal (slices 4, 5, 6 and 7) sections. Hematoxylin and eosin and Masson's trichrome staining were used for tissue evaluation. The tibial insertion length and direct insertion length were measured using ImageJ software. The relationship between direct insertion and anatomical parameters was analysed using Spearman's correlation coefficient.

Results

The mean medial anteroposterior length was 52.1 ± 3.7 mm. The mean tibial insertion lengths of the PCL were 9.8 ± 1.7 mm (slice 1), 10.8 ± 1.1 mm (slice 2) and 8.5 ± 0.9 mm (slice 3). The mean direct insertion lengths were 8.5 ± 1.4 mm (slice 1), 9.7 ± 1.0 mm (slice 2) and 7.5 ± 0.9 mm (slice 3). Direct insertion in slice 2 was significantly correlated with medial anteroposterior length (p < 0.05). In the sagittal plane, the MM posterior root was adjacent to the anterior edge of the PCL tibial insertion, with a clear bony change-point at the border. In the coronal plane, the medial tibial plateau and PCL were separated by the MM tibial attachment (slices 5 and 6).

Conclusions

The tibial attachment area of the PCL was shorter than that reported in previous gross anatomical studies. These findings provide important anatomical insights for PCL reconstruction and are essential for preventing iatrogenic MM injuries during tibial tunnel creation.

Level of Evidence

N/A.

Purpose

It is difficult to diagnose discoid lateral meniscus (DLM) clinically, and various imaging modalities are employed to aid diagnosis. However, the use of radiographic parameters as a diagnostic tool remains unvalidated. Hence, this study aims to determine the validity of radiographic parameters and their role in diagnosing DLM.

Methods

This is a retrospective study of magnetic resonance imaging (MRI)-diagnosed DLM. MRI films were reviewed, and the presence of DLM was identified (Group A). A control group of age-and gender-matched patients with no reported abnormalities in their knees on MRI was identified (Group B). X-ray parameters for all patients were measured, including squaring of the lateral femoral condyle (LFC), lateral joint space (LJS), cupping of lateral tibial plateau (CLTP), lateral tibial obliquity (LTO), fibula head height (FHH), height of the lateral intercondylar spine (LIS) and LFC notching, with normalised ratio (NR) values obtained for LJS and FHH by dividing their respective values against the interepicondylar distance (IED). Data analysis was performed to compare differences between both groups.

Results

A total of 72 patients (36 in each group) were included. Our study showed that Group A had significantly smaller squaring of LFC (p = 0.012), wider LJS (p < 0.01), less CLTP (p < 0.01) and reduced LTO (p < 0.01). However, these same parameters were not significant in historical studies. There were no significant differences in the remaining parameters between Groups A and B. In addition, as compared to historical studies that show significant differences in LJS and FHH when comparing normal menisci versus DLM, our present study did not show a significant difference in the latter parameter.

Conclusion

Widened LJS is a consistent X-ray parameter seen in DLM. Inconsistencies in the significance of other radiographic parameters should drive caution when using them for diagnosis, and other imaging modalities should be utilised to confirm the presence of DLM.

Level of Evidence

Level III.