Shubin Stein, MD Afdelingen for Ortopædkirurgi Hospital for Special Surgery New York, NY, USA. Strickland, MD Sports Medicine and Shoulder Service, Hospital for Special Surgery, New York, NY, USA.
PF Pain in the Skeletally Immature Patient
Diagnosis and Management
Introduction
Anterior Knee Pain of the Adolescent
Patients can work with their doctors to establish an activity regimen that limits the duration and intensity of athletic activities and instead focuses on low-impact sports such as cycling and swimming. In addition, a physical therapy regimen that includes exercises to help increase the flexibility and strength of the hip and thigh muscles that support the knee is important.
Patellofemoral Pain Syndrome (PFPS)
It is important for patients to develop good exercise habits, including wearing appropriate athletic shoes, warming up thoroughly before exercise, stretching before and after physical activity, and establishing a routine that supports hip and core strength.
Osgood-Schlatter’s Disease
These activities result in repetitive strain of the patellar tendon from the strong pull of the quadriceps muscle. Typical findings are irregularity of the apophysis with separation from the tibial tuberosity almost in stages and fragmentation in later stages [10] (Fig. 1.1).
Sinding-Larsen-Johansson (SLJ) Syndrome
Typically, the patient's pre-pain activity level is assessed and the total number of hours spent doing rigorous sprinting and jumping is reduced. Lateral radiographs show mild bony changes at the distal pole of the patella, consistent with SLJ.
Bipartite Patella
Surgical techniques including excision of the accessory fragment, lateral retinacular release [39], or vastus lateralis release [40]. Matic's meta-analysis also reports positive results with 105 of the 125 patients who underwent either surgical or conservative treatments being symptom-free and able to return to sports after the intervention.
Trochlear and Patellar Juvenile Osteochondritis Dissecans (JOCD) of the Knee
Because of the unique forces exerted on the patellofemoral joint, the diagnosis and treatment of trochlear OCD may differ from that of the femoral condyle. Of the operative patients, eight had signs of surgical recovery and were able to return to sport.
Hoffa’s Fat Pad Impingement
Several studies have also looked at the association of patellofemoral misalignment with Hoffa's fat pad. Initial treatment of Hoffa's fat pad impingement typically involves physical therapy coupled with NSAIDs to combat inflammation.
Plica Syndrome
On physical examination and palpation of the patellar tendon, patients show tenderness along both sides of the patellar tendon. For patients who do not experience relief of symptoms with conservative treatment, surgical excision of the fat pad may provide relief.
Tibial Tubercle Fracture
In terms of physical therapy, programs focused on strengthening the quadriceps and increasing hamstring flexibility have been shown to be successful. A recent meta-analysis of the literature on outcomes and complications of 336 pediatric tibial tubercle fractures reported compartment syndrome in.
Patellar Sleeve Fracture
It is important to be aware of some of the complications that rarely accompany tibial tubercle fractures, including compartment syndrome at initial presentation, meniscal tears, and knee stiffness and genu recurvatum after treatment [106]. A surgical complication to be aware of is excessive exposure or inadvertent injury to the anterior surface of the distal pole of the patella.
Rehabilitation of Patellofemoral Pain
Straight leg raises can be performed in different directions to facilitate knee and hip strength. Simple exercises such as hip abduction and clamshells for the hip as well as lying and side planks for the core can be used.
Surgical treatment of osteochondritis dissecans lesions of the patella and trochlea in the pediatric and adolescent population. Functional and radiological outcome of juvenile osteochondritis dissecans of the knee treated with transarticular arthroscopic drilling.
Anterior Knee Pain
Epidemiology
Etiology
Early theories investigated changes in the articular cartilage of the patella as the source of pain. This led to a broadening of the patellofemoral misalignment theory of anterior knee pain and the development of the tissue homeostasis theory [15].
Evaluation of Anterior Knee Pain History
Functional "giving way" of the knee must be carefully distinguished from knee instability or patellar dislocation. Score includes 1 point for each of the following: (1) ability to place palms on floor while bending forward with straight legs in standing position, (2) each elbow that is hyperextended, (3) each knee that is hyperextended - weights , (4) any thumb that can be flexed back to touch the forearm, and (5) any little finger that can be flexed back more than 90° [ 39 ].
Rehabilitation Concepts in Anterior Knee Pain
Nonsteroidal anti-inflammatory drugs and corticosteroid injections are first-line treatments for osteoarthritis of the knee, including patellofemoral arthritis; however, their utility in treating patellofemoral pain syndrome is unclear. Based on these and other factors, the American Academy of Orthopedic Surgeons clinical guidelines do not recommend the use of HA for osteoarthritis of the knee [64].
Iliotibial Band Syndrome
Lateral Patellofemoral Compression
Physical examination reveals excessive lateral patellar tilt with a tight lateral retinaculum limiting patellar eversion and medial patellar mobility. LPFC is one of the conditions that, when refractory to nonoperative treatment, may meet the indications for lateral retinacular release or lengthening, although this is uncommon.
Patellar Tendinopathy
Up to 14% of patients with patellar tendinopathy will develop a chronic case of the condition [80], and approximately 10% of non-operatively treated patients eventually undergo surgical intervention, which mainly consists of arthroscopic or open debridement at the lower pole. of the patella. [91]. This involves excision of the portion of persistent tendinopathy, with repair of the tendon if a significant portion of the tendon is debrided.
Medial Patellar Plica Syndrome
It is performed by applying force to the inferomedial pole of the patella while flexing the knee to 90° from full extension. The test is considered positive if the patient experiences pain with the knee in extension and relief of pain with the knee in 90° flexion.
Chondral Pathology
Much of the recent research involving patellar cartilage defects has focused on surgical treatments, including microfracture, autologous chondrocyte implantation (ACI), particulate juvenile cartilage allograft, osteochondral autograft transfer, and patellofemoral realignment. They found that type I lesions at the lower pole and type II lesions at the lateral facet of the patella responded well to TTO, with good/excellent results.
Conclusion
Intra-articular injections of hyaluronan in the treatment of osteoarthritis of the knee: a randomized, double-blind, placebo-controlled, multicenter trial. Results of surgical treatment of chronic patellar tendinosis (jump's knee): a systematic review of the literature.
Malalignment and Overload Syndromes
Pathogenesis
This excess pressure can lead to accelerated wear of the chondral surfaces and increased loading of the subchondral bone, ultimately leading to persistent pain and functional disability (Fig. 3.1b).
History and Physical Exam
The rest of the examination should be performed with the patient in the supine position. The medial and lateral aspects of the patella should be palpated to see if this causes pain.
Diagnostic Imaging
Mobility of the patella should be assessed and medial and lateral sliding should be noted according to the number of quadrants the patella translates. Special attention should be paid to the location of the chondral defect within the patella and/.
Treatment
After time-out, a diagnostic knee arthroscopy is performed with special attention to the chondral surface of the patella and trochlea. A small osteotome is used to perform the proximal aspect of the osteotomy, and great care is taken to avoid damage to the patellar tendon.
Results
The authors also evaluated the ability to return to sport (RTS) following TTO and found that 83.3% of patients were able to perform RTS an average of 7.8 months after surgery. While the authors found significant improvement in all outcome scores after TTO, they identified increased age, increased femoral anteversion, foot pronation, and postoperative patellofemoral crepitus as negative prognostic factors.
Complications
Multiple osteochondral allograft transplantation with concurrent tibial tuberculosis osteotomy for multifocal chondral disease of the knee. A systematic review of 21 studies on osteotomy of tibial tubercles and more than 1000 knees: indications, clinical results, complications and reoperations.
Patellofemoral Arthritis
Etiology of Patellofemoral Arthritis
In the setting of the patella alta, excessive loading of the distal patella may occur due to decreased engagement of the patella in the trochlea. Finally, high-grade trochlear dysplasia is present in the vast majority of patients with isolated PF OA [ 22 ].
Nonoperative Treatment
The concentration of load on a smaller area of the cartilage results in increased pressure and risk of cartilage wear. Rotational disturbances in the axial plane, resulting in excessive TT-TG and patellar tilt, increase lateral patellar facet pressure, which predisposes to lateral PF joint cartilage damage.
Operative Treatment
Clinical efficacy of the microfracture technique for articular cartilage repair in the knee: an evidence-based systematic review. Preliminary results of a new one-stage cartilage restoration technique: small crushed articular cartilage allograft for chondral defects of the patella.
Imaging in Patellofemoral Pain
Anatomy and Biomechanics of the Patellofemoral Joint Osseous Anatomy
The position of the median ridge (solid thin arrow) demarcates four different types of patella. It runs from the lower pole of the patella and inserts on the tibial tubercle.
Imaging of the Patellofemoral Joint Radiography
Patella alta (Fig. 5.6) results from high positioning of the patella in relation to the trochlea and an elongated patellar tendon. Additionally, the Caton-Deschamps (as well as Blackburne-Peel) measurement refers to the articular length of the patella in relation to the proximal tibia.
Patellofemoral Disorders/Specific Causes of Patellofemoral Pain
The extension mechanism of the knee can be better imaged with the help of ultrasound and MRI (Fig. 5.16) than on radiography. There is severe joint space narrowing, subchondral plate irregularity, and full-thickness cartilage loss (white bracket) on both sides of the joint in the lateral aspect of the patellofemoral compartment.
Cartilage Imaging
In vivo T(1rho) and T(2) mapping of articular cartilage in knee osteoarthritis using 3T MRI. Radiographic patterns of knee osteoarthritis in the community: importance of the patellofemoral joint.
Patellofemoral Instability
Instability in the Skeletally Immature Patient
Natural History
Similarly, patella alta, an independent risk factor for patellar instability [5], cannot be treated with a tibial tubercle distalization procedure because of the open tibial tubercle apophysis and risk of a growth arrest leading to a recurvatum deformity. While trochleoplasty is more commonly performed in Europe compared to the United States, most surgeons delay them until skeletal maturity because of the risk of injury to the open distal femoral physis.
Surgical Indications
Operative Techniques Surgical Considerations
Anatomical reconstruction of the medial patellofemoral ligament in children and adolescents using a pedicled quadriceps tendon graft. Clinical results of isolated reconstruction of the medial patellofemoral ligament for recurrent dislocation and subluxation of the patella.
Acute Patellar Dislocation (First-Time Dislocator)
The medial patellofemoral ligament (MPFL) has been shown to provide 60% of the inhibition of lateral patellar translation [9]. It is known that the retinacular expansion of the extensor mechanism of the knee is also an important stabilizing force.
Treatment Options
There is still some controversy as to whether a patient undergoing a simple loose body removal or a more involved osteochondral repair should also undergo stabilization of the patellofemoral joint. The risks of the additional procedure must be considered, but the case for preventing posttraumatic arthritis in the setting of potential recurrent instability is compelling.
MPFL Repair
MPFL Reconstruction
Recommendations for Treatment of First-Time Patellofemoral Dislocators
Because of the high rate of recurrent instability and potential for resultant cumulative chondral damage in the absence of stabilization, concurrent MPFL reconstruction is generally performed if patients proceed to surgery for loose body removal. Careful range of motion and control of knee pain and swelling are prescribed first, along with strengthening of the core and hip muscles.
Bibliography
Zone of injury of the medial patellofemoral ligament after acute patellar dislocation in children and adolescents. Isolated Repair of the Medial Patellofemoral Ligament in Primary Dislocation of the Patella: A Prospective Randomized Study.
Recurrent Patellar Instability
Patients with recurrent patellar instability should be thoroughly evaluated to determine the optimal surgical approach to address their pathology. Finally, in the setting of medial patellofemoral ligament disruption in the skeletally immature patient, an anatomic medial patellofemoral ligament reconstruction should be undertaken.
Lateral Release
In addition, lateral release can be complicated by medial instability if the release extends proximally into the attachment of the vastus lateralis obliquus [15]. Furthermore, if there is osseous misalignment, a bony procedure and a lateral release can be successfully combined.
Medial Repair
These poor results can be attributed to several factors, the most important being that the lateral release fails to align the patella more medially. Both studies concluded that recovery in the chronic or recurrent setting produced unsatisfyingly high rates of recurrence.
Medial Patellofemoral Ligament Reconstruction
Others have advocated a duplicated semitendinosus allogeneic graft to replicate the broad patellar attachment of the medial patellofemoral ligament [27]. Understanding the biomechanics of the medial patellofemoral ligament and the important points of the reconstructive technique will help minimize potential complications of this procedure.
Trochleoplasty
Furthermore, patients with trochlear dysplasia can be successfully treated with other procedures that do not endanger the articular cartilage of the trochlea. Thus, the large percentage of patients with trochlear dysplasia and recurrent patellar instability do not necessarily warrant a trochleoplasty.
Tibial Tubercle Osteotomy
Furthermore, they showed no difference in the quality of outcomes for increasing severity of trochlear dysplasia. Distalization of the tibial tubercle causes the patella to engage the trochlea earlier in flexion and can be used to increase bony restraint, preventing lateral instability.
Femoral Derotational Osteotomy
In vitro study of the effect of medial patellofemoral ligament reconstruction and medial tibial tuberosity transfer on lateral patellar stability. Reconstruction of the medial patello-femoral and patello-tibial ligaments for the treatment of patellar instability.
Patellofemoral Instability Surgery Complications: How to Avoid Them
Complications of Soft Tissue Surgery
Suturing techniques may include fixation of the suture anchor to the medial patellar border or rotation of the quadriceps maintaining its proximal attachment to the patellar soft tissue. It should be noted that there are inherent risks associated with the use of procedures that use patellar tunnels to attach the MPFL reconstruction to the patella.
Patella Fracture The Complication
Other options are to attach the graft only to the medial patellar retinaculum/periosteum or to perform a quadriceps turn-off, which eliminates the need for any patellar tunnels or fixation devices on the patellar side of the soft tissue reconstruction [12, 13 ] . The available literature suggests that fully transverse patellar tunnels have an increased risk of associated patellar fracture, and therefore the authors do not recommend this surgical technique.
Malpositioned Tunnels, Anisometry, and Recurrent Instability The Complication
Assessment of graft length displacement will help determine its isometry and relative positioning of the femoral tunnel. The true anatomic insertion of the graft into the femur should be determined and confirmed after the knee is fully extended (check the graft length change along the knee's arc of motion to ensure proper positioning of the femoral tunnel).
Medial Overload OA The Complication
Since the MPFL is most important during the first 30° of flexion, deviations from proper kinematics will have significant clinical implications. Finally, it is critical to assess the lateral retinaculum after the MPFL fixation is completed.
Medial Instability/Lateral Retinacular Reconstruction The Complication
It is important not to release the lateral retinaculum prior to MPFL fixation to help limit iatrogenic overmedialization and iatrogenic medial instability as the graft is tensioned without a lateral restraint. Furthermore, a lateral retinacular "Z" extension rather than a simple release allows the advantage of releasing the lateral overdensity but still provides satisfactory soft tissue restraint without completely destabilizing the lateral structures as a complete lateral release would. do.
General Complications (MPFL Reconstructions)
Do not perform lateral release before MPFL fixation, and if a lateral release has been performed previously, ensure that the patella is centered in the trochlea and not medialized at the time of femoral fixation. As always, after completing the reconstruction, assess patellar slip both medially and laterally to assess for gross asymmetry and observe patellar behavior through a full ROM.
Complications of Tibial Tubercle Osteotomies
In the majority of treated patients, it was patellar instability, while the rest had pain and malalignment of the patella. In addition to potential complications of the osteotomy itself, potential consequences of TTO have been reported, such as overcorrection where forces are transferred to the medial and proximal facets of the patella in patients with pre-existing medial chondral disease [25, 26].
Nonunions/Delayed Unions The Complication
To help limit the risk of nonunion, special attention is needed to ensure that satisfactory fixation is placed orthogonally to the slope of the osteotomy site and that adequate compression is maintained with fixation for relative bone placement. An additional technique can be used with distalization of the patella alta osteotomy, where the distal edge of the ledge is "feathered" instead of blunt.
Tibial Fractures The Complication
The osteotomy's distal extent can be tapered or "springed" with the use of the saw and lateral end completed with osteotomes. Feathering and tapering the distal edge of the shingles and limiting its length will help not to violate the transition to the anterior cortical arch of the tibia, which can be a stress increase and.
Generalized Complications (Tibial Tubercle Osteotomies)
Complications of Trochleoplasty and Femoral Osteotomies
Arthrofibrosis The Complication
As such, postoperative adhesions, loss of range of motion, and resulting pain may occur [30, 31]. This wide range of reported levels could well be attributed to different surgical techniques and evolving physiotherapy regimens.
Cartilage Perforation/Subchondral Fracture Propagation/
Loss of Sulcus Morphology/Arthritis The Complication
Depending on the type of surgical technique used, always pay attention to the use of burrs and proximity to the subchondral plate and cartilage to help limit heat-induced necrosis during sulcus deepening. Reinforce the medial and lateral corticocancellous trochlear margins to help prevent margin subsidence, thereby maintaining sulcus angle and congruence.
Generalized Complications (Trochleoplasty)
Anteromedial tibial tubercle transfer in patients with chronic anterior knee pain and a subluxation-type patellar malformation. Medial patellofemoral ligament repair and reconstruction for the treatment of lateral patellar dislocations: Surgical technique.
Imaging in Patellofemoral Instability
Imaging of Instability Radiography
On MRI it is measured from the deepest point of the trochlear sulcus to the midpoint of the patellar tendon at its insertion on the tibial tuberosity on a direct axial view [25, 26] (Fig. 10.2). Femoral injury is indicated by proximal edema anterior to the proximal medial collateral ligament.
Normal Postoperative Imaging Appearance After Patellofemoral Procedures
