Thin flap sulcus-deepening trochleoplasty in patellar instability yields good functional outcomes without progressive cartilage deterioration in the short-term follow-up-A retrospective single-surgeon cohort study.

Purpose: Sulcus-deepening trochleoplasty (TP) effectively treats patellofemoral (PF) instability (PFI) caused by high-grade trochlear dysplasia (TD), but current evidence is based on small case series. We hypothesised, that TP would result in significant functional improvements and a low re-dislocation rate but would not accelerate the progression of PF cartilage deterioration.

Methods: We retrospectively reviewed all TP cases performed by a single surgeon between 2015 and 2021.

Clinical and radiological outcome of extended lateral approach via epicondyle osteotomy in complex lateral tibia plateau fractures involving the central and postero-lateral segments.

Introduction: The purpose of this study was to evaluate the clinical and radiological results of complex lateral tibial plateau fractures involving the central segments of the lateral tibial plateau. It was hypothesized that an extended lateral approach by using the lateral epicondyle osteotomy improves the rate of malreduction and yields to good and excellent clinical results at a mid-term follow-up.

Methods: This retrospective case series conducted at two centers evaluated complex lateral tibial plateau fractures treated with an extended lateral approach by lateral epicondyle osteotomy.

Surgically treated acute knee dislocations with knee stiffness perform equally as well as non-stiff knees when treated with arthroscopic arthrolysis.

Purpose: Postoperative knee stiffness is a common issue in multiligament knee injuries (MLKIs). This study aims to compare outcomes between MLKI patients who underwent postoperative arthroscopic lysis of arthrofibrosis (LOA) for limited range of motion (ROM) and those who did not.

Methods: Thirty-one patients (10 IIIM, nine IIIL and 12 IV) were included in this retrospective clinical study with acute type III or IV knee dislocations, while two patients were lost to follow up.

Arthroscopic Shaver-based Harvest of Minced Cartilage Results in Reduced Chondrocyte Viability and Reduced Quality of Cartilaginous Repair Tissue Compared With Open Harvest and Conventional Fragmentation.

Purpose: To characterize and compare the quality of regenerative cartilage tissue (ReCT) after conventional minced cartilage (CMC) and arthroscopic minced cartilage (AMC), in terms of cell viability, gene expression, and matrix synthesis and to investigate the influence of different shaver types.

Methods: Chondral tissue was harvested from the knees of 8 porcine donors. Porcine specimens were euthanized one day before harvest.

[Posterolateral instability of the knee joint].

The posterolateral corner of the knee is composed of a multilayered complex of ligamentous, musculotendinous, and capsular structures, which interact in a synergistic stabilizing manner with the central structures, particularly the posterior cruciate ligament. Injuries of the posterolateral corner are generally accompanied by rupture of the posterior cruciate ligament. Depending on the injured structures, injuries of the posterolateral corner result in posterolateral rotational instability alone (Fanelli A) or with lateral instability (Fanelli B/C).

Influence of leg axis alignment on MRI T2* mapping of the knee in young professional soccer players.

Background: Investigation of the association between leg axis alignment and biochemical MRI in young professional soccer players in order to identify a potential influence of the leg axis on cartilage regions at risk.

Methods: Sixteen professional soccer players (21 ± 3 years) underwent static and dynamic leg axis analysis via radiation free DIERS formetric 4 D as well as 3-T MRI examination of both knees. Quantitative T2* mapping of the knee cartilage was performed and T2* values were evaluated as 144 regions of interest.

[Multiligament instabilities of the knee in sports injuries : An update of the Hamburg concept].

Background: Knee dislocation (KD) is a rare but severe injury of the knee joint, with a high rate of concomitant neurovascular injuries. The severity of the ligamentous injury, which is classified according to the Schenck classification, the mechanism of injury, concomitant injuries and individual factors determine the treatment strategy in KD.

Treatment Strategy: Furthermore, a clear differentiation between high-velocity (HV) and low-velocity (LV) injuries is necessary.

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.

The Influence of Surgical Realignment Procedures on Dynamic Patellar Tracking: A Dynamic Magnetic Resonance Imaging-Controlled Feasibility Study.

Persisting patellar maltracking following surgical realignment often remains unseen. The aim of this study was to analyze the effects of realignment procedures on patellofemoral kinematics in patients with patellofemoral instability (PFI) and patellofemoral maltracking (PM) by using dynamic magnetic resonance imaging (MRI). Patients planned for surgical patellar realignment due to PFI and a clinically and radiologically apparent PM between December 2019 and May 2022 were included.

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.

German S2e-Guideline "Knee Dislocation".

Knee dislocation is a devastating form of multiligament injury of the knee. Due to its high complexity, there is a large number of different diagnostic and treatment strategies. With the aim of providing evidence-based treatment recommendations, the S2e guideline on knee dislocation is aimed at all professional groups involved in diagnostics and therapy (orthopaedic and trauma surgeons, physiotherapists, outpatient/inpatient surgeons, sports physicians, etc.

Comparison of Arthroscopic versus Open Placement of the Fibular Tunnel in Posterolateral Corner Reconstruction.

Introduction:  Precise fibular tunnel placement in posterolateral corner (PLC) reconstruction is crucial in restoring rotational and lateral stability. Despite the recent progress of arthroscopic PLC reconstruction techniques, landmarks for arthroscopic fibular tunnel placement and a comparison to open tunnel placement have not yet been described. This study aimed to (1) identify reasonable soft-tissue and bony landmarks, which can be identified by either arthroscopy, fluoroscopy, or open surgery in anatomic fibular tunnel placement and (2) to compare accuracy and reliability of arthroscopic fibular tunnel placement with open surgery.

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.

Biplanar high tibial osteotomy for the combined correction of varus and posterior tibial slope malalignment.

Varus malalignment combined with an increased posterior tibial slope (PTS) in the ACL deficient knee is a frequent pathology; yet, treatment for this condition remains challenging. The presented biplanar osteotomy technique allows to simultaneously address both components of malalignment in a single step. A detailed preoperative planning is best achieved by means of a digital planning software and constant intraoperative imaging is performed to verify the correction angle.

Dynamic Mediolateral Patellar Translation Is a Sex- and Size-Independent Parameter of Adult Proximal Patellar Tracking Using Dynamic 3 Tesla Magnetic Resonance Imaging.

Purpose: To provide normal values for physiological patellofemoral tracking in a representative group of healthy individuals, as well as sex differences, using real-time 3T-magnetic resonance imaging (MRI) and to test for the reliability of the presented technique.

Methods: One hundred knees of healthy individuals with no history of patellofemoral symptoms were scanned with dynamic MRI sequences, during repetitive cycles of flexion (40°) and full extension. Within a 30-seconds time-frame, three simultaneous, transverse slices were acquired.

The Clinical Outcome of Different Total Knee Arthroplasty Designs in One-Stage Revision for Periprosthetic Infection.

Background: Despite the growing number of studies reporting on the best surgical treatment in the management of periprosthetic joint infection, there are no robust data regarding the type of infected prosthesis before any kind of exchange arthroplasty. To overcome these shortcomings, we asked the following questions: (1) What is the survivorship of nonhinged and hinged knee implants after one-stage exchange arthroplasty and (2) what is the functional outcome after one-stage exchange procedure focusing on knee prostheses and the type of prior infected knee implant. In a secondary radiographic analysis, we also investigated if (3) the type of femoral bone morphology measured by the inner femoral diameter influences the rate of aseptic failures also in patients with periprosthetic joint infection.

Additional lateral extra-articular tenodesis in revision ACL reconstruction does not influence the outcome of patients with low-grade anterior knee laxity.

Introduction: There is limited evidence on the indications of lateral extra-articular tenodesis (LET) in revision ACLR. The aim of this study was to evaluate the influence of the LET in patients with revision ACLR with preoperative low-grade anterior knee laxity.

Methods: Between 2013 and 2018, 78 patients who underwent revision ACLR with preoperative low-grade anterior knee laxity [≤ 5 mm side-to-side difference (SSD)] were included in the retrospective cohort study.

Interobserver reliability is higher for assessments with 3D software-generated models than with conventional MRI images in the classification of trochlear dysplasia.

Purpose: Trochlear dysplasia is a significant risk factor for patellofemoral instability. The severity of trochlear dysplasia is commonly evaluated based on the Dejour classification in axial MRI slices. However, this often leads to heterogeneous assessments.

[Combined PCL ligament bracing and ACL reconstruction in acute knee dislocation (Schenck IV) - The Hamburg Approach : Video article].

Objective: Stepwise reconstruction of knee stability and physiological kinematics in acute knee dislocation.

Indications: The operative technique is demonstrated in a case of multiligamentous injury of the knee with involvement of both cruciate ligaments and additional medial and lateral peripheral injuries (type IV according to Schenck classification).

Contraindications: Critical soft tissue conditions, infections, old age, obesity, lack of compliance.

What Is the Mid-term Survivorship of Infected Rotating-hinge Implants Treated with One-stage-exchange?

Background: Despite the growing number of studies reporting on periprosthetic joint infection (PJI), there is little information on one-stage exchange arthroplasty for the revision of infected rotating-hinge prostheses, which can be among the most difficult PJI presentations to treat.

Questions/purposes: After one-stage direct exchange revision for an infected rotating-hinge TKA prosthesis, and using a multimodal approach for infection control, we asked: (1) What is the survivorship free from repeat revision for infection and survivorship free from reoperation for any cause? (2) What is the clinical outcome, based on the Oxford Knee Score, of these patients at the latest follow-up?

Methods: Between January 2011 and December 2017, we treated 101 patients with infected rotating-hinge knee prostheses at our hospital. All patients who underwent a one-stage exchange using another rotating-hinge implant were potentially eligible for this retrospective study.