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Medial Patellar Instability: Primary and Iatrogenic

Introduction Acute patellar dislocation is a common knee injury in adolescents and young adults, with primary patellar dislocations occurring at a rate of 42 per 100,000 person-years. However, the vast majority of primary and recurrent dislocations are in a lateral direction, as a result of the resultant lateral force vector acting on the patella at the time of injury, as well as predisposing anatomical risk factors…

Lateral Patellar Instability:: Diagnosis, Treatment Algorithm, Conservative Approaches, Surgical Techniques, Outcomes, Rehabilitation and Future Directions

Introduction Lateral patellar instability is a common knee disorder, particularly in children and adolescents. Its aetiology is multifactorial, and typically it is caused by a combination of soft tissue and osseous abnormalities, such as medial patellofemoral ligament (MPFL) incompetency, dysplasia, and patella alta. The annual risk of lateral patellar dislocation ranges from 5.8 to 77 per 100,000 persons, with girls aged 10 to 17 at the…

Pathological Torsion of the Lower Limb

Intrinsic and Extrinsic Limb Factors It is the author’s opinion that patellofemoral (PF) symptoms should be considered as those that arise from the joint itself and are considered intrinsic factors and those that are caused by forces external to the joint itself and are considered extrinsic factors. The intrinsic factors are largely the recipients of the applied forces and include ligaments, the patella and trochlea, both…

Tibial Tuberosity Osteotomies

Introduction Normal patellar tracking is mediated statically by the bone structures, passively by the soft tissue stabilisers and actively by the musculature about the knee. Patellofemoral tracking relates to contact because the patella is physiologically intended to be centred within the trochlear groove (TG) throughout a range of motion (ROM) with a physiological pressure distribution. This is provided by two main factors: morphology and alignment, of…

Treatment Algorithm in Patellofemoral Disorders: ‘Le Menu à la Carte’

Patellofemoral Instability The patellofemoral joint (PFJ) is a highly complex structure, intimately associated with the dynamic muscle activity, including the global and central control of the limb, which is linked to the pelvis and the spine. The function of the patella is to improve the effective extension capacity of the quadriceps muscle by increasing the moment arm of the patellar tendon. To fulfil this feature, its…

Patellofemoral Anatomy and Its Surgical Implications

Medial Patellofemoral Anatomy Proximal Medial Patellar Complex As our understanding of medial patellofemoral anatomy continues to grow, the implications for surgical reconstruction have evolved. Whereas earlier reports focused on reconstruction of the medial patellofemoral ligament (MPFL) as the primary treatment for lateral patellar instability, more recent anatomical descriptions have noted additional fibres that extend proximal to the patella, leading to the development of new reconstruction techniques.…

Osteonecrosis of the Knee

Introduction The term osteonecrosis was first described by Ahlback et al. in 1968. The original description involved the spontaneous appearance of what was thought to represent focal osteonecrosis of the femoral condyle. After the hip, the knee has been determined to be the second most common location affected. Osteonecrosis has subsequently been separated into three distinct groups: spontaneous, secondary and postarthroscopic. Spontaneous osteonecrosis is the most common…

How to Manage the Active Patient with Osteoarthritis:: Biological Approaches

Introduction Osteoarthritis (OA) is a debilitating condition that can lead to chronic pain, disability, decreased quality of life and inability to perform activities of daily living. Authors have reported that OA and diabetes are responsible for the largest increase in years lived with disability at the global population level, in part because of the obesity epidemic and aging populations. It has been reported that patients with…

OCD Injuries in the Paediatric and Adult Population

Introduction Osteochondritis dissecans (OCD) is a focal, pathological lesion involving subchondral bone and the attached overlying articular cartilage. Importantly, the focal lesion is at subsequent risk for the development of subchondral degeneration, destabilisation of the lesion from the articular surface, formation of loose bodies and accelerated joint degeneration. OCD characteristically affects two distinct populations, juvenile and adult, differentiated by the presence or absence of open physes.…

Focal Chondral Injuries

Introduction Focal chondral defects ( FCDs ) constitute a common finding, with a reported incidence of 4.2% and 6.2% in the general population in patients younger than 40, resulting in more than 200,000 surgical procedures per year ( Fig. 22.1 ). , Furthermore, the prevalence is reported to be as high as 36% in athletes. Importantly, if these lesions are not addressed in a timely manner,…

A Basic Science Understanding of Cartilage Repair and Its Clinical Application

The Osteochondral Unit and Biology of Cartilage Repair The function of diarthrodial joints relies on the health and integrity of the osteochondral unit, which encompasses the composite tissue of articular cartilage, calcified cartilage layer and subchondral bone. , Alterations in any of these tissue components can lead to disruption of normal joint homoeostasis and function and contribute to various pathological conditions and afflictions. Articular Cartilage Normal…

Synthetic Meniscal Substitutes

Introduction In search of the ideal meniscal substitute, natural and synthetic materials for meniscal replacement have been reported with variable outcomes. Although meniscus allograft transplantation is the only clinically available option for total meniscus replacement, disadvantages to its use include limited donor supply, the need for size matching, the risk of disease transmission and the possibility of an immune response to affect healing and incorporation. Therefore…

Meniscus Deficiency and Meniscal Transplants

Introduction Meniscal injury is the most common knee pathological condition encountered in orthopaedic clinics. Although only a few decades ago the menisci were considered a vestigial structure, today we understand their importance as key structures in providing optimal knee function. , The menisci not only assist in shock absorption and reduction of pressure loads across the knee but also have an important role in providing knee…

Meniscal Ramp Lesions

Introduction Meniscal ramp lesions have a reported incidence ranging from 16% to 24% in primary and revision anterior cruciate ligament (ACL) reconstructions. There is no consensus on the exact definition of a meniscal ramp lesion. A meniscal ramp lesion was first described in 1983 by Hamberg et al., who reported this type of lesion during open surgical repair. In 1988 Strobel characterised a particular type of meniscal…

Meniscal Radial Tears

Introduction Approximately 40% to 70% of the load transmitted through the knee is done by the menisci. The mechanical load absorption ability of the menisci is to convert axial load into circumferential hoop stress. The menisci also play a major role in maintaining knee stability. The integrity of the meniscal belt is thus fundamental to preserve correct knee kinematics and avoid degenerative changes of the joint.…

Meniscal Root Tears

Introduction The role of the meniscus in knee stability and tibiofemoral alignment and its unique ability to turn axial joint loads into hoop stresses have become increasingly understood. With the integral role the meniscus plays in joint preservation, it is easy to surmise why there is an established association among injury and subsequent loss of meniscal tissue and progression of osteoarthritis. Meniscal root tears specifically have…

Meniscal Tears: Meniscectomy Versus Repair

Introduction Abundant research has elucidated the many biomechanical and functional characteristics of the meniscus, including its role in providing translational stability, rotational stability, proprioception and absorption of a significant proportion of load dispersed at the tibiofemoral joint. , , Thus with time orthopaedic surgeons have arrived at an increasingly cohesive mindset that the meniscus is a structure whose healthy native anatomy is of significant advantage to…

Meniscus Biomechanics

Introduction The biomechanical properties of the menisci have been extensively studied. Once thought to be a functionless structure akin to an embryonic remnant, it is now recognised that the menisci are critical for maintaining proper knee kinematics and function and for the prevention of the development and progression of knee osteoarthritis. The ability of the menisci to assist in maintaining a normal knee environment is largely…

Meniscal Pathology: Meniscus Anatomy

Introduction In the United States a meniscal tear is the most common diagnosis among patients undergoing knee arthroscopy, with incidence rates reported to exceed 50 people per 100,000. Patients with meniscal tears or meniscal deficiency have been shown over time to progress to early degenerative joint disease and osteoarthritis, demonstrating the essential chondroprotective role of this structure in the human knee joint. The meniscus optimises axial…

Arthroscopic Primary Repair of the Cruciate Ligaments

Introduction Anterior cruciate ligament (ACL) tears are one of the most common injuries of the knee, with approximately 200,000 ruptures in the United States each year. On the contrary, only 3% of the injured knee ligaments are isolated posterior cruciate ligament (PCL) injuries because PCL tears more often occur in the setting of the multiligament injured knee (MLIK). The standard surgical treatment for ACL and PCL…