Patient-Individualized Identification of Medial Patellofemoral Ligament Attachment Site to Femur Using "CLASS" MRI Sequences.

Background: Malposition of the femoral tunnel during medial patellofemoral ligament (MPFL) reconstruction may increase the risk of recurrence of patellar dislocation due to isometric changes during flexion and extension. Different methods have been described to identify the MPFL isometric point using fluoroscopy. However, femoral tunnel malposition was found to be the cause of 38.1% of revisions due to patellar redislocation. This high rate of malposition has raised the question of individual anatomical variability. Methods: Magnetic resonance imaging (MRI) was performed on 80 native knees using the CLASS (MRI-generated Compressed Lateral and anteroposterior Anatomical Systematic Sequence) algorithm to identify the femoral MPFL insertion. The insertions were identified on the MRI views by 2 senior orthopaedic surgeons in order to assess the reliability and reproducibility of the method. The distribution of the MPFL insertion locations was then described in a 2-plane coordinate system and compared with MPFL insertion locations identified with other methods in previously published studies. Results: The CLASS MPFL footprint was located 0.83 mm anterior to the posterior cortex (line 1) and 3.66 mm proximal to the Blumensaat line (line 2). Analysis demonstrated 0.90 and 0.89 reproducibility and 0.89 and 0.80 reliability of the CLASS method to identify the anatomical femoral MPFL insertion point. The distribution did not correlate with previously published data obtained with other methods. The definitions of the MPFL insertion point in the studies by Schöttle et al. and Fujino et al. most closely approximated the CLASS location in relation to the posterior femoral cortex, but there were significant differences between the CLASS method and all 4 previously published methods in relation to the proximal-distal location. When we averaged the distances from line 1 and line 2, the method that came closest to the CLASS method was that of Stephen et al., followed by the method of Schöttle et al. Conclusions: The CLASS algorithm is a reliable and reproducible method to identify the MPFL femoral insertion from MRI views. Measurement using the CLASS algorithm shows substantial individual anatomical variation that may not be adequately captured with existing measurement methods. While further research must target translation of this method to clinical use, we believe that this method has the potential to create a safe template for sagittal fluoroscopic identification of the femoral tunnel during MPFL surgical reconstruction. Level of Evidence: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Comparison of different intraoperative reduction monitoring methods in a cadaveric intraarticular calcaneal fracture model: 3D scan vs arthroscopy vs nanoscopy.

AIMS: Visualization of the subtalar joint surface in surgical management of calcaneal factures remains a big challenge and anatomic reduction of the articular surface is essential for a good clinical outcome. We hypothesize that video-assistance can provide superior fracture reduction compared to fluoroscopy and that nanoscopy (NSC) achieves more extensive visualization compared to fracturoscopy (FSC). METHODS: Ten human cadaveric feet with artificially pre-fractured intraarticular calcaneal fractures with involvement of the posterior facet were treated via a minimal invasive subtalar approach. After initial control of reduction by 2D fluoroscopy, the reduction was further analyzed intraoperatively by FSC and NSC. 3D Scan served as gold standard control of reduction. Need of revision of reduction after the different visualization techniques was recorded and the extent of visualization of the subtalar joint surface in the medio-lateral dimension was compared for FSC and NSC. To quantify access and visualization of the medial and posterior facet, a depth gauge was used to measure from laterally at the clinically widest portion of the calcaneus targeted to the sustentaculum tali. The distance in millimetres was referred to the complete medio-lateral distance seen on paracoronal CT at the widest portion of the calcaneus. RESULTS: Fracture analysis in preoperative CT-scans according to Sanders classification revealed four type IC, two IIA, three IIC and one IIIAC fractures. Mean visualization of the medial and posterior facet was significantly improved with NSC (30.4 ± 3.78 mm) compared to FSC (23.6 ± 6.17 mm) (p = 0.008). An imperfect reduction requiring revision was more often required with NSC compared to FSC. Insufficient reduction using video-assistance was found in two cases. CONCLUSION: In order to optimize subtalar joint reduction and congruency, video-assisted techniques, especially NSC, provide superior visualization and thus can improve reduction in the surgical treatment of intraarticular calcaneal fractures.

Comparison of Onlay Anchor Fixation Versus Transosseous Fixation for Lateral Extra-articular Tenodesis During Revision ACL Reconstruction.

Background: There is evidence on the clinical effectiveness of the Lemaire technique for lateral extra-articular tenodesis (LET) in patients undergoing revision anterior cruciate ligament reconstruction (ACLR), but the best fixation technique is unknown. Purpose: To compare the clinical outcomes of 2 fixation techniques after revision ACLR: (1) onlay anchor fixation, which would avoid tunnel conflict and physis injury, and (2) transosseous tightening and interference screw fixation. Pain at the area of LET fixation was also assessed. Study Design: Cohort study; Level of evidence, 3. Methods: This was a retrospective 2-center study of patients with first-time revision ACLR and either LET with anchor fixation (aLET) with a 2.4-mm suture anchor or LET with transosseous fixation (tLET). Outcomes at minimum 12-month follow-up were assessed with the International Knee Documentation Committee score, Knee injury and Osteoarthritis Outcome Score, visual analog scale for pain at the LET fixation area, Tegner score, and anterior tibial translation (ATT). A subgroup analysis within the aLET group investigated passing the graft over or under the lateral collateral ligament (LCL). Results: In total, 52 patients were included (26 patients in each group); the mean ± SD follow-up was 13.7 ± 3.4 months. No statistically significant differences were detected between the groups with respect to patient-reported outcome scores, clinical examination, or instrumented testing (side-to-side difference in ATT at 30° of flexion; aLET, 1.5 ± 2.5 mm; tLET, 1.6 ± 1.7 mm). Clinical failure was detected in 1 patient with aLET and none with tLET. Subgroup analysis revealed a small, nonsignificant flexion deficit in knees in which the iliotibial band strand was passed under (n = 42) or over (n = 10) the LCL. No clinically relevant tenderness was detected at the area of LET fixation in any group (aLET, 0.6 ± 1.3; tLET, 0.9 ± 1.7; over the LCL, 0.2 ± 0.6; under the LCL, 0.9 ± 1.6). Conclusion: Onlay anchor fixation and transosseous fixation of the LET were equivalent with respect to outcome scores and instrumented ATT testing. Clinically, there were minor differences in passage of the LET graft over or under the LCL.

The value of magnetic resonance imaging in the preoperative diagnosis of tibial plateau fractures: a systematic literature review.

PURPOSE: The outcome of a tibial plateau fracture (TPF) depends on the fracture reduction achieved and the extent of soft-tissue lesions, including lesions in the ligaments, cartilage, and menisci. Sub-optimal treatment can result in poor knee function and osteoarthritis. Preoperative planning is primarily based on conventional X-ray and computed tomography (CT), which are unsuitable for diagnosing soft-tissue lesions. Magnetic resonance imaging (MRI) is not routinely performed. To date, no literature exists that clearly states the indications for preoperative MRI. This systematic review aimed to determine the frequency of soft-tissue lesions in TPFs, the association between fracture type and soft-tissue lesions, and the types of cases for which MRI is indicated. METHODS: A systematic review of the literature was based on articles located in PubMed/MEDLINE and the Cochrane Central Register of Controlled Trials (CENTRAL), supplemented by searching the included articles' reference lists and the ePublication lists of leading orthopedic and trauma journals. RESULTS: A total of 1138 studies were retrieved. Of these, 18 met the eligibility criteria and included a total of 877 patients. The proportion of total soft-tissue lesions was 93.0%. The proportions of soft-tissue lesions were as follows: medial collateral ligament 20.7%, lateral collateral ligament 22.9%, anterior cruciate ligament 36.8%, posterior cruciate ligament 14.8%, lateral meniscus 48.9%, and medial meniscus 24.5%. A weak association was found between increasing frequency of LCL and ACL lesions and an increase in fracture type according to Schatzker's classification. No standard algorithm for MRI scans of TPFs was found. CONCLUSION: At least one ligament or meniscal lesion is present in 93.0% of TPF cases. More studies with higher levels of evidence are needed to find out in which particular cases MRI adds value. However, MRI is recommended, at least in young patients and cases of high-energy trauma.

Anterolateral versus modified posterolateral approach for tibial plateau fractures with involvement of the posterior column: a cadaveric study.

INTRODUCTION: The aim of this study was to compare the reduction quality of the anterolateral (AL) and modified posterolateral approach (PL) in lateral tibial plateau fractures involving the posterior column and central segments. METHODS: Matched pairs of pre-fractured cadaveric tibial plateau fractures were treated by either AL approach (supine position) or PL approach (prone position). Reduction was controlled by fluoroscopy and evaluated as satisfying or unacceptable. Afterwards, the reduction was examined by 3D scan. RESULTS: 10 specimens (3 pairs 41B3.1, 2 pairs 41C3.3) were evaluated. PL approach achieved significantly (p 0.00472) better fracture reduction results (0.4 ± 0.7 mm) of the posterior column compared to the AL group (2.1 ± 1.4 mm). Fracture steps involving the central area of the lateral plateau were insufficiently reduced after fluoroscopy using both approaches. CONCLUSION: Optimal reduction of displaced tibial plateau fractures involving the posterolateral column necessitates a posterior approach, which can be conducted in prone or lateral positioning. The anterolateral approach is indicated in fractures with minor displacement of the posterolateral rim but fracture extension in the latero-central segments. In these cases, an additional video-assisted reduction or extended approaches are helpful.

Influence of Medial Osteotomy Height and Hinge Position in Open Wedge High Tibial Osteotomy: A Simulation Study.

(1) Background: In treating medial unicompartmental gonarthrosis, medial open wedge high tibial osteotomy (mOWHTO) reduces pain and is intended to delay a possible indication for joint replacement by relieving the affected compartment. This study aimed to investigate the influence of the osteotomy height with different hinge points in HTO in genu varum on the leg axis. (2) Methods: Fifty-five patients with varus lower leg alignment obtained full-weight bearing long-leg radiographs were analyzed. Different simulations were performed: Osteotomy height was selected at 3 and 4 cm distal to the tibial articular surface, and the hinge points were selected at 0.5 cm, 1 cm, and 1.5 cm medial to the fibular head, respectively. The target of each correction was 55% of the tibial plateau measured from the medial. Then, the width of the opening wedge was measured. Intraobserver and interobserver reliability were calculated. (3) Results: Statistically significant differences in wedge width were seen at an osteotomy height of 3 cm below the tibial plateau when the distance of the hinge from the fibular head was 0.5 cm to 1.5 cm (3 cm and 0.5 cm: 8.9 +/- 3.88 vs. 3 cm and 1.5 cm: 11.6 +/- 4.39 p = 0.012). Statistically significant differences were also found concerning the wedge width between the distances 0.5 to 1.5 cm from the fibular head at the osteotomy height of 4 cm below the tibial plateau. (4 cm and 0.5 cm: 9.0 +/- 3.76 vs. 4 cm and 1.5 cm: 11.4 +/- 4.27 p = 0.026). (4) Conclusion: A change of the lateral hinge position of 1 cm results in a change in wedge width of approximately 2 mm. If hinge positions are chosen differently in preoperative planning and intraoperatively, the result can lead to over- or under-correction.

Influence of the Fluoroscopy Setting towards the Patient When Identifying the MPFL Insertion Point.

(1) The malposition of the femoral tunnel in medial patellofemoral ligament (MPFL) reconstruction can lead to length changes in the MPFL graft, and an increase in medial peak pressure in the patellofemoral joint. It is the cause of 36% of all MPFL revisions. According to Schöttle et al., the creation of the drill canal should be performed in a strictly lateral radiograph. In this study, it was hypothesized that positioning the image receptor to the knee during intraoperative fluoroscopy would lead to a relevant mispositioning of the femoral tunnel, despite an always adjusted true-lateral view. (2) A total of 10 distal femurs were created from 10 knee CT scans using a 3D printer. First, true-lateral fluoroscopies were taken from lateral to medial at a 25 cm (LM25) distance from the image receptor, then from medial to lateral at a 5 cm (ML5) distance. Using the method from Schöttle, the femoral origin of the MPFL was determined when the femur was positioned distally, proximally, superiorly, and inferiorly to the image receptor. (3) The comparison of the selected MPFL insertion points according to Schöttle et al. revealed that the initial determination of the point in the ML5 view resulted in a distal and posterior shift of the point by 5.3 mm ± 1.2 mm when the point was checked in the LM25 view. In the opposite case, when the MPFL insertion was initially determined in the LM25 view and then redetermined in the ML5 view, there was a shift of 4.8 mm ± 2.2 mm anteriorly and proximally. The further positioning of the femur (distal, proximal, superior, and inferior) showed no relevant influence. (4) For fluoroscopic identification of the femoral MPFL, according to Schöttle et al., attention should be paid to the position of the fluoroscopy in addition to a true-lateral view.

Compressed Lateral and anteroposterior Anatomical Systematic Sequences «CLASS¼: compressed MRI sequences with assessed anatomical femoral and tibial ACL's footprints, a feasibility study.

PURPOSE: This study's main objective is to assess the feasibility of processing the MRI information with identified ACL-footprints into 2D-images similar to a conventional anteroposterior and lateral X-Ray image of the knee. The secondary aim is to conduct specific measurements to assess the reliability and reproducibility. This study is a proof of concept of this technique. METHODS: Five anonymised MRIs of a right knee were analysed. A orthopaedic knee surgeon performed the footprints identification. An ad-hoc software allowed a volumetric 3D image projection on a 2D anteroposterior and lateral view. The previously defined anatomical femoral and tibial footprints were precisely identified on these views. Several parameters were measured (e.g. coronal and sagittal ratio of tibial footprint, sagittal ratio of femoral footprint, femoral intercondylar notch roof angle, proximal tibial slope and others). The intraclass correlation coefficient (ICCs), including 95% confidence intervals (CIs), has been calculated to assess intraobserver reproducibility and interobserver reliability. RESULTS: Five MRI scans of a right knee have been assessed (three females, two males, mean age of 30.8 years old). Five 2D-"CLASS" have been created. The measured parameters showed a "substantial" to "almost perfect" reproducibility and an "almost perfect" reliability. CONCLUSION: This study confirmed the possibility of generating "CLASS" with the localised centroid of the femoral and tibial ACL footprints from a 3D volumetric model. "CLASS" also showed that these footprints were easily identified on standard anteroposterior and lateral X-Ray views of the same patient, thus allowing an individual identification of the anatomical femoral and tibial ACL's footprints. LEVEL OF EVIDENCE: Level IV diagnostic study.

Does Age Affect the Outcomes of Core Decompression for the Treatment of Kienböck Disease?

Background: Core decompression of the distal radius is a minimally invasive technique that has demonstrated good clinical outcomes in the treatment of Kienböck disease. However, the effectiveness of core decompression has not been compared in different age groups. The aim of this study is to compare the outcomes of core decompression in patients <45 years of age to those ≥45 years of age. Methods: This retrospective study included 36 patients with Kienböck disease who were treated with core decompression over a 20-year period. The mean follow-up was 7 years. Outcome measures included visual analogue scale pain score (VAS), active range of flexion/extension at the wrist, grip strength, and modified Mayo wrist score. The patients were divided into two age groups namely <45 years (younger group; n = 22) and ≥45 years (older group; n = 12) and the outcome measures were compared between the two age groups. Results: There were no statistically significant differences between the outcomes of the two age groups. Conclusion: The outcomes of core decompression of the distal radius for Kienböck disease in older patients (≥45 years) are favorable and similar to those seen in younger patients (<45 years). Level of Evidence: Level III (Therapeutic).

Safety of total hip arthroplasty for femoral neck fractures using the direct anterior approach: a retrospective observational study in 86 elderly patients.

BACKGROUND: The femoral neck fracture is one of the most common fractures in the elderly. A variety of methods and approaches are used to treat it. Total hip arthroplasty is a preferred approach in independent, mobile, elderly patients, given its more favorable long-term outcome. Our hypothesis is that the direct anterior approach in geriatric trauma patients has a lower dislocation-rate with the advantage of early recovery due to a muscle sparing approach and therefore early possible full weight-bearing. METHODS: Patients were retrospectively sought who suffered a femoral neck fracture from 2008 to 2013. All patients were treated through a direct anterior approach and using the same brand of implants. Medical history, standardized physical exam, conventional pelvic plain and axial hip x-rays, Harris Hip Score, Merle D'Aubigné and Postel and SF-36 were assessed. RESULTS: Eighty-six patients were included in the study with a mean age of seventy-five years. The mortality rate was 16.7 %. Complications were encountered in nineteen patients (22.0 %) who needed operative revision and one postoperative complication (1.2 %) which could be handled conservatively. There were five intraoperative complications (5.8 %), two dislocations (2.3 %), one aseptic loosening in a non-cemented stem (1.2 %), six periprosthetic fractures in non-cemented stems (6.9 %), one displacement of a non-cemented cup (1.2 %), two early infections (2.3 %) and three hematomas (3.5 %) recorded. CONCLUSIONS: Although the direct anterior approach is associated with a rather long learning curve we have found it to preserve the soft-tissues with no injury to abductors. It therefore shows an early advantage in elderly patients in terms of early recovery and therefore early possible full weight-bearing. Fracture treatment with dual mobility cups might lead to lower dislocation rates, but are associated with higher costs. Due to higher complication rates in non-cemented versus cemented shafts, we have changed our practice towards favoring cemented femoral stems in patients with suspected or manifest osteoporosis.