Complications and Radiographic Outcomes of Tibial Tubercle Osteotomy at Minimum 5-Year Follow-up.

Background: Tibial tubercle osteotomy (TTO) is a commonly utilized surgery in the treatment of patellofemoral instability and chondrosis. A number of case series studies have reported on the mid- and long-term outcomes with varying complication rates.

Purpose: To report the incidence of major complications after TTO and the rate of progression of knee osteoarthritis at midterm follow-up.

Analyzing Alignment Error in Tibial Tuberosity-Trochlear Groove Distance in Clinical Scans Using 2D and 3D Methods.

Background: Tibial tuberosity-trochlear groove distance (TT-TG) is often used as a primary metric for surgical decision-making in the treatment of patellofemoral instability (PFI), particularly when considering tibial tubercle transfer. Although TT-TG has high interrater reliability, it is prone to measurement differences caused by the alignment of the patient's leg in a scanner gantry, potentially influencing surgical decision-making. Quantification of this error within the clinical literature remains limited.

Three-Dimensional Imaging of the Patellofemoral Joint Improves Understanding of Trochlear Anatomy and Pathology and Planning of Realignment.

Three-dimensional (3D) modeling using digital or printed models provides a unique perspective that caters to cognitive spatial ability in a way that can add to our understanding and mental representations of human anatomy. This is particularly useful in the setting of trochlear dysplasia, where the morphology of the groove can exhibit substantial variability and complexity. Using 3D reformatted images and models, a pragmatic understanding of how morphology influences patellofemoral pathology can be gleaned.

The Morphologic Patella Entry Point Into the Proximal Trochlea Is More Lateral in Recurrent Dislocators Than Controls as Measured by Entry Point-Trochlear Groove Angle.

Purpose: To create a metric for evaluating the degree of laterality of the patella's entry into the trochlea, the entry point-trochlear groove (EP-TG) angle, and to evaluate if this laterality is associated with recurrent patella instability.

Methods: The time frame of the study was January 2020 to February 2023. The inclusion criteria were patients treated by the senior author (J.

A modified Delphi consensus statement on patellar instability: part I.

Aims: The aim of this study was to establish consensus statements on the diagnosis, nonoperative management, and indications, if any, for medial patellofemoral complex (MPFC) repair in patients with patellar instability, using the modified Delphi approach.

Methods: A total of 60 surgeons from 11 countries were invited to develop consensus statements based on their expertise in this area. They were assigned to one of seven working groups defined by subtopics of interest within patellar instability.

A modified Delphi consensus statement on patellar instability: part II.

Aims: The aim of this study was to establish consensus statements on medial patellofemoral ligament (MPFL) reconstruction, anteromedialization tibial tubercle osteotomy, trochleoplasty, and rehabilitation and return to sporting activity in patients with patellar instability, using the modified Delphi process.

Methods: This was the second part of a study dealing with these aspects of management in these patients. As in part I, a total of 60 surgeons from 11 countries contributed to the development of consensus statements based on their expertise in this area.

Three-Dimensional Printing of Models of Patellofemoral Joint Articular Cartilage in Patients With Patella Instability for Observing Joint Congruity.

Three-dimensional (3D) modeling and printing are increasingly used in the field of orthopaedic surgery for both research and patient care. One area where they are particularly helpful is in improving our understanding of the patellofemoral (PF) joint. Heretofore, morphological studies that use 3D models of the PF joint have primarily been based on computed tomography imaging data and thus do not incorporate articular cartilage.

Incidence of Early Adverse Events After Tibial Tubercle Osteotomy.

Background: Tibial tubercle osteotomy (TTO) is a commonly utilized surgical procedure for the treatment of patellofemoral instability. Although midterm and long-term outcomes are known, perioperative complications have not been consistently reported.

Purpose: To identify the incidence and predictors of adverse events in the first 90-day perioperative period after TTO.

Three-Dimensional Reproductions for Surgical Decision-Making in the Treatment of Recurrent Patella Dislocation.

Patellofemoral instability may be attributed to a variety of soft tissue and osseous factors, of which dysplasia of the femoral trochlea significantly predisposes patients to recurrent instability events. Surgical planning and decision-making remain wholly predicated upon two-dimensional imaging-derived measurements and classification systems, although aberrant patellar tracking in the setting of trochlea dysplasia is a three-dimensional (3-D) complexity. 3-D reconstructions of the patellofemoral joint (PFJ) may be considered to better comprehend the complex anatomy of patients with recurrent patella dislocation and/or trochlea dysplasia.

Localization of the Adductor Tubercle in the Skeletally Immature: A Computed Tomography Study With Patellofemoral Surgical Implications.

Background: The adductor tubercle of the distal femur is utilized by surgeons as an anatomic landmark to identify graft anchor placement during medial patellofemoral ligament (MPFL) and medial quadriceps tendon femoral ligament (MQTFL) reconstruction for patellofemoral instability. In the skeletally immature population, its location relative to the physis has not been well defined.

Purpose: To identify the location of the adductor tubercle relative to the distal femoral physis in skeletally immature individuals and gain insight regarding optimal graft anchor placement for pediatric patients undergoing MPFL and MQTFL reconstruction.

Reconceptualization of Trochlear Dysplasia in Patients With Recurrent Patellar Dislocation Using 3-Dimensional Models.

Background: Common classification schemes, measurements, and surgical planning for trochlear dysplasia are predicated on 2-dimensional imaging views.

Purpose: To investigate patellofemoral joint osseous anatomy using 3-dimensional (3D) printed models to describe osseous anatomic trochlear variations in patients with recurrent patellar dislocation.

Study Design: Cross-sectional study; Level of evidence, 3.

Quadriceps Tendon Attachment Technique for Medial Quadriceps Tendon-Femoral Ligament (MQTFL) Reconstruction in the Surgical Treatment of Recurrent Patella Dislocation.

Medial quadriceps tendon-femoral ligament (MQTFL) reconstruction for prevention of recurrent patella dislocation is an alternative to medial patellofemoral ligament (MPFL) reconstruction. Because the reconstruction graft attaches to the quadriceps tendon, no patella drill hole is required, thereby eliminating iatrogenic fracture risk. The procedure remains anatomically accurate and early results are comparable to MPFL reconstruction for preventing patella dislocation.

Coronal Malalignment-When and How to Perform a Tibial Tubercle Osteotomy.

Coronal malalignment of the patellofemoral joint may contribute to both instability as well as pain and joint overload. The use of distal realignment procedures has evolved to include uniplanar and multiplanar osteotomies, which allows patient-specific treatment. With a careful understanding of the complex pathoanatomy, including osseous, soft tissue, and dynamic muscular factors, an appropriately designed tibial tubercle osteotomy (TTO) is an invaluable tool for the orthopedic surgeon to improve joint biomechanics and off-load articular injuries.

Current Concepts Regarding Patellofemoral Trochlear Dysplasia.

Optimal treatment of patients with patellofemoral trochlear dysplasia and recurrent patellar instability requires in-depth understanding of this complex structural anomaly. An extensive review of the literature suggests that dysplasia occurs as a result of aberrant forces applied to the patellofemoral joint in the majority of cases. Evidence supports surgical stabilization that reconstructs the medial patellofemoral and/or medial quadriceps tendon-femoral ligament without added trochleoplasty in the majority of patients with trochlear dysplasia and recurrent patellar instability.

Editorial Commentary: The Best Medial Patellofemoral Reconstruction May Include Components of Both Quadriceps and Patellar Attachments.

Given different functions of the medial quadriceps tendon-femoral ligament and medial patellofemoral ligament components of the proximal medial patellar restraints, reconstructions to the midpoint of the medial patellofemoral ligament and medial quadriceps tendon-femoral ligament are probably optimal, combining the benefits of both in surgical treatment of recurrent patella instability.

Medial Patellofemoral Ligament Reconstruction in Skeletally Immature Patients.

Patellofemoral instability is a common problem affecting children and adolescents, with recurrent instability often requiring surgical intervention. Medial patellofemoral ligament (MPFL) reconstruction has become a mainstay for the treatment of patellofemoral instability because of the biomechanical importance of the MPFL against lateral dislocation as well as the high frequency of MPFL injury following traumatic patellar dislocation. The concern in managing skeletally immature patients is the potential for injury to the distal femoral physis.

When and How I Add Trochleoplasty in the Treatment of Recurrent Patella Instability.

Long experience and recent evidence suggest that trochleoplasty is needed in very few patella stabilization surgeries. As trochleoplasty adds risk, this author recommends it only in patients with high degrees of dysplasia, prominent supratrochlear spurs, ligamentous laxity, and more dramatic J signs.

An Updated Overview of the Anatomy and Function of the Proximal Medial Patellar Restraints (Medial Patellofemoral Ligament and the Medial Quadriceps Tendon Femoral Ligament).

The medial patellofemoral ligament (MPFL) has been widely accepted to function as "the primary static restraint to lateral patellar displacement." However, current growing evidence suggests that there is a complex of medial patellofemoral/tibial ligaments, both proximal [MPFL, and medial quadriceps tendon femoral ligament (MQTFL)], and distal (medial patellotibial ligament and the medial patellomeniscal ligament) which restrain lateral patellar translation at different degrees of knee flexion. Specifically, the MQTFL has gained popularity over the last decade because of pure soft tissue attachments into the extensor mechanism that allow for avoidance of drilling tunnels into the patella during reconstruction.

Repair of the medial patellofemoral ligament with suture tape augmentation leads to similar primary contact pressures and joint kinematics like reconstruction with a tendon graft: a biomechanical comparison.

Purpose: To compare suture tape-augmented MPFL repair with allograft MPFL reconstruction using patellofemoral contact pressure and joint kinematics to assess the risk of patellofemoral over-constrainment at point zero.

Methods: A total of ten fresh frozen cadaveric knee specimens were tested in four different conditions of the MPFL: (1) native, (2) cut, (3) reconstructed with tendon graft, and (4) augmented with suture tape. The patellofemoral mean pressure (MP), peak pressure (PP) and contact area (CA) were measured independently for the medial and lateral compartments using pressure-sensitive films.

Unilateral anterior knee pain is associated with increased patellar lateral position after stressed lateral translation.

Purpose: To objectively compare side-to-side patellar position and mobility in patients with idiopathic unilateral anterior knee pain (AKP) using a stress-testing device concomitantly with magnetic resonance imaging. It is hypothesized that the painful knees present greater patellar mobility than the contralateral non-painful knees.

Methods: From a total sample of 359 patients, 23 patients with idiopathic unilateral AKP (30.

Fifteen-Year Minimum Follow-Up of Anteromedial Tibial Tubercle Transfer for Lateral and/or Distal Patellofemoral Arthrosis.

Purpose: To evaluate a minimum 15-year clinical and radiographic follow-up after anteromedial tibial tubercle transfer (anteromedialization [AMZ]) for lateral and/or distal patellar facet arthrosis.

Methods: Patients treated from 1996 to 2000 were contacted. The inclusion criteria were a minimum of 15 years' follow-up after AMZ for isolated persistent retropatellar pain related to lateral and/or distal patellar chondrosis.

Combined Soft Tissue Reconstruction of the Medial Patellofemoral Ligament and Medial Quadriceps Tendon-Femoral Ligament.

Patellar dislocation is a major orthopaedic concern in pediatric and adult populations, with both conservative and surgical options available. Several surgical techniques of the combined or isolated reconstruction of the medial patellofemoral ligament are described in the literature using different grafts, locations, and types of fixations, providing different advantages and disadvantages. New recent developments in cadaveric dissection studies have unveiled the importance of structures that were neglected until recently, such as the medial quadriceps tendon-femoral ligament, which provides a connection between the medial femur and the quadriceps tendon component of the knee extensor mechanism.

Medial Quadriceps Tendon Femoral Ligament Reconstruction Technique and Surgical Anatomy.

Medial patellofemoral ligament reconstruction risks patellar fracture with the osseous violation necessary for patellar attachment. Anatomic studies identify an entire medial patellofemoral complex of structures responsible for medial restraint to patellar lateral instability. One specific component of this complex is the medial quadriceps tendon femoral ligament (MQTFL).

Radiographic Landmarks for the Anterior Attachment of the Medial Patellofemoral Complex.

Purpose: Because fluoroscopy is often used in graft placement during patellar stabilization surgery, the purpose of this study was to describe the radiographic landmarks for the anterior attachment midpoint of the medial patellofemoral complex (MPFC).

Methods: Seventeen fresh-frozen cadaveric knees were dissected, and the MPFC was exposed from the articular side after a lateral parapatellar approach. The midpoint of the anterior attachment of the MPFC was identified using a ruler and marked with a pin.