Arthroscopic Patella Realignment

Abstract

Background:

Patellofemoral pain is a prevalent condition that contributes to significant morbidity and can be difficult to manage or refractory to nonoperative treatment.

Indications:

Persistent patellofemoral pain syndrome despite nonoperative management.

Technique Description:

Arthroscopic patellar realignment.

Results:

Retrospective cohorts show that patellar realignment statistically improves functional status and pain for patients with patellofemoral pain syndrome.

Discussion/Conclusion:

This technique has proven to be an effective and safe method in the management of refractory patellofemoral pain and maltracking, yielding improvement in patient symptoms and functional status.

Patient Consent Disclosure Statement:

The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Graphical Abstract

This is a visual representation of the abstract.

Video Transcript

This technique video describes an arthroscopic patellar realignment.

In this video, we will discuss the background of patellofemoral pain syndrome, review the surgical indications for an arthroscopic patellar realignment, walk through the technique, and finally discuss the outcomes and clinical significance of this procedure.

Background

Patellofemoral pain syndrome presents with anterior knee pain and often occurs due to patellar maltracking or cartilage overload.

Epidemiology

This condition is relatively common, with an estimated ⁵ point prevalence of 5.7% to 28%.

History

Patellofemoral pain syndrome most commonly affects pediatric and adolescent patients and is associated with such risk factors as anatomic susceptibility—including patella alta, trochlear dysplasia, and lateral patellar tilt—and demographic characteristics—including age and female sex. Patients present with anterior knee pain and feelings of subjective patellar maltracking.

Clinical Significance

Approximately one-third of patients with patellofemoral pain syndrome will experience persistent symptoms, contributing to significant morbidity. This condition can also contribute to cartilage damage and long-term joint degeneration. ¹

Indications

History and Physical Examination

Evaluation begins with a thorough history and physical examination. This includes documenting current patient symptoms, such as anterior knee pain or subjective maltracking. A standard bilateral knee examination is then performed, with particular attention paid to patellar maltracking without increased translation.

Imaging

Radiographs are utilized to evaluate patient anatomy and rule out arthritis. Magnetic resonance imaging can be used to further assess patient anatomy, recognize fat pad impingement or cartilage damage, and rule out patellofemoral instability.

Nonoperative Management

An initial trial of nonoperative management should be attempted, consisting of physical therapy with emphasis on quadriceps strengthening, patellofemoral bracing, and activity modification guided by pain and symptoms.

Surgical Management

Surgical intervention is indicated for persistent patellofemoral pain and maltracking. ³ Notably, it is not an alternative to medial patellofemoral ligament (MPFL) reconstruction for patients with patellofemoral instability or dislocation.

Preoperative Planning

A comprehensive discussion of the risks and benefits of surgery should be performed with the patient and family before the procedure. This discussion should include operative risks, such as infection, deep vein thrombosis, damage to surrounding structures, and arthrofibrosis. The goals of surgery are to decrease anterior knee pain and improve patellofemoral tracking.

Before surgery, physicians should also review relevant patient imaging, with attention paid to the potential need for additional procedures and to that patient's specific anatomy.

Technique Description

Patient Positioning

Patients are positioned supine. A tourniquet can be inflated on the operative thigh, per the surgeon’s preference.

Diagnostic Arthroscopy

A complete diagnostic arthroscopy is then performed through standard anteromedial and anterolateral portals. At this time, consideration and execution of additionally required procedures—such as lateral release, cartilage restoration, or plica excision—is made.

Arthroscopic Visualization

Anatomic landmarks for the repair are then identified—including the MPFL attachment sides, the extent of the medial patellofemoral complex, and the patellar borders.

Suture Passing

With the knee in extension, sutures are passed as close to the MPFL attachment sites as possible through 2 spinal needles. Parallel or crossover configurations can be utilized, depending on patient pathology.

Here we can see the demonstration of multiple sutures being passed from one spinal needle to the other, with the assistance of a loop retriever. The operative knee depicted here is shown after successful completion of suture passing.

Suture Retrieval

A 1-cm longitudinal incision is then made, just medial to the medial border of the patella. A forceps is used to bluntly dissect to the medial aspect of the knee, with extreme care taken to avoid dissection into the joint.

From inside the joint, we can see the blunt forceps dissection, which is carefully performed to avoid violation of the joint capsule. A loop retriever is then used to bring all sutures through the previously made medial incision.

The previously placed sutures can now be seen, all emerging from this medial incision.

Suture Tensioning

With the knee in flexion, the sutures are then tensioned under direct arthroscopic visualization. This process requires precision, and it is essential that proper patellar tilt and tracking are confirmed during this step.

The arthroscope is used here to view the previously placed sutures. Traction can then be applied to translate the patella. The sutures are tensioned to achieve proper alignment of the patella with respect to the trochlea.

Sutures Secured

With the knee in extension, the sutures are then tied under arthroscopic visualization. The repaired knee is then ranged from 0° to 30° under this visualization to ensure proper alignment. From inside the joint, we can see the secured suture line. Proper alignment confirmed under view, both in knee flexion and in knee extension, and with patellar translation.

Closure

Attention is then turned to closure. Excess fluid is removed, and the incisions are closed with 2-0 Vicryl and 3-0 Monocryl in a buried interrupted fashion. Steri strips, a sterile dressing, and an Ace wrap are applied. The patient is then placed in a hinged knee brace for postoperative use.

Postoperative Protocol

Postoperative management includes twice-weekly physical therapy with an emphasis on quadriceps strengthening. Weightbearing progresses from partial weightbearing during the first 2 weeks to weightbearing with crutches, as tolerated. Range of motion is initially limited to 90° for 2 weeks, using the hinged knee brace. The brace is then weaned, per the physical therapist’s guidance, as the patient demonstrates adequate quadriceps strength.

Return to Sport

Return to linear exercise begins at 8 to 10 weeks, with progression to noncontact pivoting and cutting after 3 months. At 4 months postoperatively, patients typically return to sport without restrictions, again per PT assessment.

Complications

Potential complications include those discussed preoperatively, as well as over- or undertensioning the repair, which may result in persistent maltracking and anterior knee pain postoperatively.

Results

While there is some literature addressing the outcomes of patellar realignment for maltracking or patellar instability, ² to our knowledge, there has not been an evaluation of this technique for the management of patellofemoral pain syndrome.

While these outcomes remain forthcoming, a current retrospective cohort of 21 patients with a mean of 34.6 months of follow-up has shown significant improvements in functional scores and reductions in patient-reported pain after the procedure. ⁴

Discussion/Conclusion

This technique provides a reliable operative solution for patellofemoral pain syndrome, particularly in pediatric and adolescent patient populations. By improving patellar tracking in relation to the trochlea, this approach can significantly reduce anterior knee pain postoperatively.