Medial Patellar Instability Research Articles

Treatment of Medial Patellar Instability With Bipolar Patellofemoral Cartilage Lesions: Staged De-rotational Distal Femoral Osteotomy Followed by Bipolar Osteochondral Allograft Transplantation and Tibial-Tubercle Osteotomy

Background: Patellar instability with symptomatic cartilage lesions in young patients is a challenging problem to treat. The use of osteotomies to correct malalignment and fresh osteochondral allograft transplantation (OCA) to address cartilage lesions and patellofemoral dysplasia is a viable treatment option for carefully selected patients. Indications: The patient is a 22-year-old woman with medial patellar instability caused by iatrogenic distal femoral external rotation and uncontained grade IV patellofemoral lesions. The patient was indicated for OCA because the lesions were too large for an osteochondral autograft transfer system (OATS) and were uncontained and not amenable to autologous chondrocyte implantation. Bipolar OCA also addresses the patient’s patellofemoral dysplasia by restoring a more morphologically normal patellofemoral joint. The external rotation and mild varus deformity are corrected with a biplanar distal femoral osteotomy. Correction of malalignment is necessary prior to OCA transplantation to avoid abnormal graft loading and thereby decrease the risk of graft failure. Technique Description: (1) Diagnostic arthroscopy and fluoroscopic examination under anesthesia. (2) Lateral closing wedge de-rotational distal femoral osteotomy. (3) Bipolar OCA with tibial tubercle osteotomy and removal of hardware. Results: In this case, the patient had significant improvement in her symptoms and had full knee range of motion with a normal gait at 3 months after surgery. Depending on a patient’s preoperative function and the specific pathology, full recovery can take considerably longer. A successful outcome is considered return to activities of daily living without significant pain. Return to higher level athletic activities is significantly more unpredictable. Graft survival of bipolar patellofemoral OCA is variable, and the literature is limited by the small number of procedures performed, but published series range from 60% to 85% at 5 years. Discussion/Conclusion: A successful outcome in these unique, complex cases depends on good patient selection, preoperative planning, and surgical execution. Patellar instability can be reliably treated when the predisposing anatomical factors are appropriately corrected. Bipolar OCA can provide significant improvement in pain and function, but continues to have the highest rate of graft failure compared with other sites within the knee, and should be considered a salvage operation for patients with significant limitations in activities of daily living. 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.

Medial Patellofemoral Ligament and Lateral Patellofemoral Ligament Reconstruction after Tibial Tuberosity Transposition in a Young Woman with Patellar Instability

In patients with reccurent lateral and medial patellar instability, isolated medial patellofemoral ligament (MPFL) reconstruction may be insufficient due to poor lateral retinacular tissue quality. In this report, we describe a case of a patient that underwent simultaneous MPFL and lateral patellofemoral ligament (LPFL) reconstruction on the left knee due to chronic bidirectional patellar instability. A 29-year-old female patient presented with first-time lateral patellar dislocation five years ago due to acute strain. She underwent a tibial tuberosity transposition in another hospital. After the surgery, she suffered from recurrent medial and lateral patellar dislocation and presented to our center. MPFL and concomitant LPFL reconstruction on the left knee was simultaneously performed due to bilateral patellar dislocation. The patella was stable postoperatively, and the patient underwent physiotherapy with successful results to date. Single-time patellar dislocation should be treated conservatively. Surgical treatment after the first episode of dislocation can magnitude the risk of postoperative complications. The simultaneous reconstructing of the LPFL yields patellar fixation indistinguishable from the native LPFL. These grafts provide separate tensioning depending on body anatomy, allowing for individualized stability. Anatomical MPFL reconstruction is supported by well-established high-quality research. Reconstructing the LPFL anatomically yields patellar fixation indistinguishable from the native LPFL.

Surgical Technique for Lateral Patellofemoral Ligament Reconstruction Using Bone Tunnels: A New Method.

Medial patellar instability (lateral patellofemoral ligament tear) is a rare condition which is commonly associated with lateral release for lateral patellar instability. LPFL is a lateralstabilizer of the patellofemoral joint. Reconstruction of LPFL is necessary to provide stability to the patella-femoral joint in patients with instability. We describe a novel technique of trans-osseous reconstruction of LPFL to gain stability and have better graft incorporation. A doubled peroneus longus graft is inserted into the patellar tunnel and secured with an endo button on the anteromedial aspect of the patella; the other end is then inserted into the insertional point on the femur and secured with an interference screw. This is an easy, novel, and reproducible technique which can be used to reconstruct LPFL.

Lateral Retinacular Release for Treatment of Excessive Lateral Pressure Syndrome: The Capsule-Uncut Immaculate (CUI) Technique

Lateral retinacular release of the patella is the main surgical treatment for excessive lateral pressure syndrome. It was first described by Merchant and Mercer in 1974. The main complications of arthroscopic lateral retinacular release are hemarthrosis and medial patellar instability. The main causes of these complications are the disturbance of the synovial membrane of the joint capsule and excessive release of the lateral retinaculum. In this article, we introduce a method for arthroscopic lateral retinacular release that maintains the overall structure of the joint capsule: capsule-uncut immaculate (CUI) lateral retinacular release.

Lateral Patellofemoral Ligament Reconstruction: A Biomechanical Comparison of 2 Techniques

Background: The importance of maintaining lateral patellar stabilizing structures has been demonstrated by the presence of iatrogenic medial patellar instability after lateral retinacular release (LRR) procedures. In patients with medial patellar instability, lateral patellofemoral ligament (LPFL) reconstruction has been clinically shown to restore patellar stability while improving patient-reported outcomes. However, the biomechanics associated with different LPFL reconstruction techniques remain largely unknown. Purpose: To (1) investigate whether LPFL reconstruction restores medial patellar translation compared with the intact state after LRR and (2) evaluate for any biomechanical differences between soft tissue and osseous LPFL reconstruction techniques. Study Design: Controlled laboratory study. Methods: A total of 7 knees were included in the final analysis. The knees were dissected, and the tibia and femur were potted. An eye screw was then placed at the midpoint of the patella perpendicular to the medial surface. A custom jig was constructed to allow for a 1-kg load to be applied to the quadriceps muscle. Medial patellar displacement was investigated at 0°, 10°, 20°, 30°, 45°, 60°, and 90° of knee flexion using a tensile testing machine with a 20-N medial force applied to the patella. Medial patellar displacement was assessed in 4 states: intact, LRR, soft tissue LPFL reconstruction (inserted through incisions in the iliotibial band, quadriceps tendon, and patellar tendon), and osseous LPFL reconstruction. Results: The LRR group had significantly greater medial patellar translation compared with the intact group throughout flexion (P < .01 to P = .029). The soft tissue LPFL reconstruction group demonstrated significantly greater medial patellar translation at 30° (P = .020) and 45° (P = .025) compared with the intact group, with less translation compared with the LRR group at all degrees of knee flexion except for 45° (P = .065). The osseous LPFL reconstruction group demonstrated significantly greater medial patellar translation compared with the intact group at 30° of flexion (P = .036), with significantly less translation compared with the LRR group from 0° to 30° (P < .01 to P = .013). The soft tissue LPFL reconstruction group (15.94 ± 2.55 mm) demonstrated significantly greater medial patellar translation at 10° of flexion compared with the osseous LPFL reconstruction group (14.16 ± 2.34 mm) (P = .033). Conclusion: Soft tissue LPFL reconstruction led to significantly greater medial patellar translation at 30° and 45° compared with the intact state, while osseous LPFL reconstruction produced significantly greater translation only at 30°. Both the soft tissue and the osseous reconstruction techniques resulted in comparable medial patellar translation at all degrees of knee flexion except for 10°, in which osseous reconstruction was more similar to the intact state. Clinical Relevance: Compared with LRR, soft tissue LPFL reconstruction was able to restore stability against medial patellar translation at most degrees of knee flexion, while osseous LPFL reconstruction did not provide adequate stabilization beyond 30° of flexion. While the LPFL does appear to have osseous insertions, soft tissue reconstruction functioned more similarly to the intact state after LRR.

Lateral Patellofemoral Ligament Reconstruction With Semitendinosus Allograft in the Setting of Previous Lateral Release

The lateral patellofemoral ligament acts to resist medial displacement of the patella. When medial subluxation occurs, it usually has an iatrogenic cause such as prior lateral release, an over-tightened medial patellofemoral ligament reconstruction, or detachment of the vastus lateralis from the patella. The justification for lateral retinacular release has historically been to address extensor mechanism issues such as imbalance of the mechanism due to increased retinacular tension. We present a Technical Note on the treatment of chronic medial patellar instability due to a previous lateral retinacular release using a soft-tissue reconstruction approach with a semitendinosus allograft.

Lateral Patellofemoral Ligament Reconstruction With a Hamstring Allograft

Background: Medial patellar instability is rare but may occur after lateral retinacular release. The lateral patellofemoral ligament is a significant stabilizer for medial and lateral patellar displacement, and soft tissue–based reconstruction may restore its stabilizing effect. Indications: Lateral patellofemoral ligament reconstruction (LPFLR) is indicated for patellar instability failing exhaustive nonoperative measures. Technique Description: Diagnostic arthroscopy for medial patellofemoral ligament (MPFL) status, patellar tracking, chondral status, and postoperative changes of lateral retinacular release is conducted. A 5-cm incision is made between the midpoint of the patella and the lateral epicondyle, or a single midline incision can be used if performing a concomitant MPFL reconstruction. Dissection is carried down to the lateral retinaculum and capsule, and two 1-cm incisions are made at the distal and proximal patella through the patellar and quadriceps tendon, respectively. The lateral epicondyle is then directly palpated, and two 1-cm incisions are made directly anterior and posterior to the epicondyle into the iliotibial band in full extension. A hamstring allograft is then shuttled in a V-shaped configuration from the quadriceps tendon through the iliotibial band and finally to the patellar tendon. Excess graft is trimmed and doubled over proximally and distally to replicate the normal (or contralateral) 0° to 15° of patellar eversion. Trial resting length and tension is set with temporary sutures through the proximal and distal doubled graft in full extension. The knee is taken through full range of motion to ensure there is no graft tightening in flexion or loosening in full extension. Eversion and patellar translation are then examined. Heavy nonabsorbable sutures are used to set length of the doubled allograft proximally and distally. Results: Case series of LPFLR have demonstrated significant improvements in patients’ pain, Lysholm score and Knee Injury and Osteoarthritis Outcome Score, and kinesiophobia with no instability events and normal range of motion at short-term follow-up. Discussion/Conclusion: Medial patellar instability can occur following lateral retinacular release and patients experiencing instability despite nonoperative treatment are likely to benefit from a soft tissue–based LPFLR. Although other nongraft-based techniques may confer similar outcomes, the authors find it more reliable to perform a lateral reconstruction as described.

Trends in Lateral Retinacular Release from 2010 to 2017.

Historically, lateral retinacular release (LRR) procedures have been utilized in the treatment of a variety of patellofemoral disorders, including lateral patellar instability. However, in the past decade, there has been an increasing awareness of the importance of the lateral stabilizers in patellar stability, as well as the complications of LRR, such as recurrent medial patellar instability. The purpose of this study was to investigate current trends in LRR procedures from 2010 through 2017 using a large national database. The American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) database was queried for arthroscopic LRR procedures (the Current Procedural Terminology [CPT] code, 29873) from 2010 to 2017. The number and incidence of lateral release procedures, both isolated and nonisolated, were analyzed and separated into cohorts for analysis. Age and gender of the LRR cohort was investigated and compared with all other orthopaedic procedures during the same time period in the NSQIP database. In addition, concomitant procedures and associated International Classification of Disease-9th Revision (ICD-9) and ICD-10th Revision (ICD-10) codes were analyzed over time and between LRR groups. From 2010 to 2017, 3,117 arthroscopic LRRs were performed. The incidence for LRR was 481.9 per 100,000 orthopaedic surgeries in 2010 and significantly decreased to 186.9 per 100,000 orthopaedic surgeries in 2017 (p < 0.01). LRR was more commonly performed in females (66%) and 58% of patients were under 44 years of age. In addition, LRR was most commonly performed with a concomitant meniscectomy (36%), synovectomy (19%), or microfracture (13%), and for a diagnosis of pain (22%). The overall incidence of LRR procedures significantly decreased from 2010 to 2017. LRRs were more commonly performed in younger, female patients for a diagnosis of pain with the most common concomitant procedure being meniscectomy, synovectomy, or microfracture.

Open versus arthroscopic release for lateral patellar compression syndrome: a randomized-controlled trial

IntroductionLateral patellar compression syndrome is one of the causes of anterior knee pain in young adults and resulted from tight lateral patellar retinaculum. The aim of our study is to compare between open and arthroscopic release of lateral patellar compression syndrome in relation of functional outcome, time of surgical procedure, length of hospital stays, intraoperative and postoperative complications as bleeding, infection, recurrence, and patellar instability with 2 years of follow-up.Materials and methods80 patients, age (21–49 years), were divided randomly into 2 groups (A and B). Group A (40 patients) were treated with open release. Group B (40 patients) were treated by arthroscopic release. All these patients are diagnosed as lateral patellar compression syndrome depending on clinical features and MRI. All patients were assessed by Lysholm knee scoring scale before surgery and at periods of 2, 6 weeks, 6, 12, and 24 months after surgery.ResultsThere is significant difference in functional outcome, measured by Lysholm knee scoring scale, between preoperative and postoperative assessment periods in both groups (P < 0.001). There is significantly better functional outcome at 2 years of follow-up with arthroscopic release (P = 0.018). There is no recurrence in both groups, but there were 4 patients develop medial patellar instability in the group of open release.ConclusionBoth open and arthroscopic lateral release for patients with isolated lateral patellar compression syndrome can be effective surgical procedures, but arthroscopic release can achieve better functional outcome.Trial registration: NCT, NCT04130412. Retrospectively registered on 3rd of June, 2020 at ClinicalTrials.gov.

Noniatrogenic Medial Patellar Dislocations: Case Series and International Patellofemoral Study Group Experience.

Background:Most patellar dislocations occur in a lateral direction because of a summed lateral force vector and predisposing anatomic risk factors. Medial patellar instability is rare and is a well-recognized iatrogenic complication of an overly aggressive lateral retinacular release. Noniatrogenic medial patellar dislocations are rare. The management of these injuries is not well described.Purpose:To describe the experience of the International Patellofemoral Study Group with patients with noniatrogenic medial patellar dislocation.Study Design:Case series; Level of evidence, 4.Methods:Members of the International Patellofemoral Study Group (N = 64) were surveyed between October 2018 and April 2019. This group was chosen because of its wide referral base and interest in patellar instability. Specialists who had encountered a patient with medial patellar instability were sent a questionnaire inquiring about details of the case, including patient demographics, medical history, level of athletic competition, injury characteristics, and treatment. Cases were confirmed by physical examination records and, in some cases, with findings on advanced radiographic imaging.Results:The survey response rate was 73% (47/64). Three of the 47 specialists (6.4%) reported they had seen a case of noniatrogenic medial patellar dislocation, for a total of 6 cases. Four cases were described as recurrent medial dislocations in the setting of hypermobile Ehlers-Danlos syndrome; 2 were treated nonoperatively, 1 underwent lateral patellofemoral ligament reconstruction, and 1 underwent derotational osteotomies. Two medial-sided patellar dislocations in collegiate athletes were sports-related injuries that required surgical debridement but no ligamentous reconstruction. None of the patients had persistent or recurrent instability at the time of their most recent follow-up.Conclusion:Noniatrogenic medial patellar dislocations are extremely rare. This case review suggests that the treatment of first-time medial patellar instability in patients without known risk factors should follow the same principles as the treatment of lateral instability with no known risk factors, which is nonoperative management. For patients with documented risk factors and recurrence, surgery to address the risk factors may be appropriate.

A Case of Chronic Patellar Instability Following Failed Lateral Release

Case: The patient is a 25-year-old female with trochlear dysplasia, native left knee lateral patellar instability and iatrogenic medial patellar instability from treatment prior to presentation. She had grade 3 cartilage loss on the majority of her patellar articular surface. She underwent concurrent medial and lateral patellofemoral ligament reconstruction, Fulkerson osteotomy, and osteochondral allografting of her entire patellar articular surface. After reconstruction she had no further instances of instability.

Lateral Patellofemoral Ligament Reconstruction: Anatomy, Biomechanics, Indications and Surgical Techniques

With the exponential increase in the arthroscopic treatment of medial patellar instability through lateral sided “capsular” releases, the iatrogenic upsurge of lateral patellar dislocations has become more evident. Although few reports exist detailing the occurrence of this phenomenon due to traumatic or idiopathic etiologies, the vast majority (over 90%) are iatrogenic. Originally described by Kaplan and later by Reider, the lateral patellofemoral ligament (LPFL) constitutes one of the main stabilizers for medial patellar translation. Thus, understanding the anatomy and biomechanics of the LPFL is of utmost importance as reconstruction can potentially restore patellar instability and improve function in cases when this mechanism is compromised. However, few studies have sought to thoroughly describe the intricate anatomy and biomechanics of the LPFL to this end. The purpose of this article was to review the evidence on the anatomy of the LPFL and the lateral retinaculum, its biomechanical behavior, and previously reported surgical approaches to LPFL reconstruction.

Biomechanical Properties of the Lateral Patellofemoral Ligament: A Cadaveric Analysis.

Medial instability of the patellofemoral joint is a rare but known phenomenon; it may result from an incompetent lateral patellofemoral ligament (LPFL). However, biomechanical details of the ligament have not been the subject of scrutiny. The purpose of this study was to describe the biomechanical properties of the LPFL. Ten fresh-frozen human cadaveric knees were dissected to identify the LPFL. The ligament was harvested with a bone plug from the patella and the femoral surface and underwent axial loading to failure. Load to failure and location of failure were recorded. Regression analysis was performed to determine which anatomic variables (midsubstance width, femoral insertion width, patellar insertion width, or percent patellar articular surface of insertion) significantly influenced load to failure. Nine of the 10 specimens failed at the midsubstance of the ligament. The mean load to failure was 90±67 N. Logistical regression showed that midsubstance width was most correlated with load to failure, which approached but did not reach significance (P=.09). Studies are warranted to investigate the clinical consequences of medial patellar instability and the best repair or reconstruction techniques available. [Orthopedics. 2018; 41(2):e797-e801.].

Treating complications of operative management for patellofemoral pain

This review paper focuses on specific complications related to patellofemoral surgery performed to manage patellofemoral pain. The three most serious complications after surgery to treat anterior knee pain (AKP) are iatrogenic medial patellar instability and multidirectional patellar instability, patella infera (or patella baja), and patellofemoral osteoarthritis. The goals of this paper are to provide best practices for avoiding complications of patellofemoral surgery, to give diagnostic advice for evaluating the failed patellofemoral surgery patient, and to present operative salvage procedures to treat these cases.

Medial Patellofemoral Ligament Reconstruction in a Revision Setting: Anchor and Interference Screw Fixation

Recurrent patellar instability is a common pathology and typically affects younger and more active patients. To prevent complete lateral dislocation of the patella, several osseous and soft-tissue procedures have been previously described, including reconstruction of the medial patellofemoral ligament (MPFL), which has been identified as the primary medial stabilizer of the patella. Several techniques have been reported for reconstruction of the MPFL, sometimes in conjunction with other procedures, with the majority showing success in the treatment and resolution of patellar instability. However, MPFL reconstruction is not free of complications, with previous reports of recurrence of medial patellar instability and patellar fracture after surgery. The objective of this Technical Note is to describe our preferred technique, comprising anchor as well as interference screw fixation, for reconstruction of the MPFL in a primary or revision setting.

Distal femoral osteotomy using a lateral opening wedge technique

To shift the weight-bearing axis of the lower limb medially by opening alateral-based metaphyseal osteotomy at the distal femur. Femoral-based valgus malalignment and symptomatic lateral unicompartimental osteoarthritis, lateral hyperpression syndrome, cartilage therapy of the lateral compartment, lateral meniscal replacement/transplantation, medial instability with valgus thrust, reconstruction of the medial collateral ligament, patellar instability and/or maltracking. Advanced cartilage damage (>grade2) or subtotal meniscal loss of the medial compartment, age >65years (relative), nicotine abuse, body mass index >30, flexion contracture >25°, corrections with awedge base >10 mm in case of congenital deformities, inflammatory or septic arthritis, severe osteoporosis. Lateral approach to the distal femur; biplanar osteotomy (frontal+ axial osteotomy), gradual opening of the osteotomy, osteotomy fixation with alocking plate. Free range of motion. Partial weight bearing with 20 kg for 2weeks, followed by progressive weight bearing thereafter. Mean improvement of knee scores from 20-30points and mean 10-year survival rate of 80% in patients with lateral unicompartimental osteoarthritis. Mean complication rate of 9%.

Medial Patellar Instability: Treatment and Outcomes.

Background:Historically, a lateral retinacular release was one of the primary surgical interventions used to treat lateral patellar instability. However, disruption of the lateral structures during this procedure has been associated with medial instability of the patella.Hypothesis:We hypothesize that good to excellent outcomes can be achieved at midterm follow-up after lateral patellotibial ligament reconstruction.Study Design:Case series; Level of evidence, 4.Methods:Thirteen patients were treated for medial patellar instability with a lateral patellotibial ligament reconstruction between May 2011 and December 2013 by a single surgeon. All patients had previously undergone a lateral release procedure and had symptomatic medial patellar instability. Patients were evaluated using patient-reported outcome scores at a minimum of 2 years postsurgery.Results:The mean Lysholm score improved from 45.6 (range, 11-76) to 71.9 (range, 30-91). The median preoperative Tegner activity scale score was 3 (range, 1-7), while the median postoperative score was 4 (range, 1-9). The median Western Ontario and McMaster Universities Arthritis Index (WOMAC) total score improved from 38 (range, 1-57) preoperatively to 6 postoperatively (range, 0-52). The mean patient satisfaction postoperatively was 8.2 (range, 5-10).Conclusion:Significantly improved outcomes can be achieved at midterm follow-up with a low rate of complications when reconstructing the lateral patellotibial ligament in the setting of iatrogenic medial patellar instability.

How to Deal With Anterior Knee Pain in the Active Young Patient

Context:Anterior knee pain (AKP) represents the most common reason to consult with a clinician who specializes in the knee. Despite the high incidence of the disorder, however, its etiology is still controversial. Many unnecessary surgeries that may damage the patient are done for this clinical entity.Evidence Acquisition:A PubMed search from 1995 through June 2016.Study Design:Clinical review.Level of Evidence:Level 4.Results:The etiology of AKP is multifactorial, and patients with AKP may therefore be divided into several subpopulations. The whole picture must be addressed for each patient to identify all potentially modifiable factors and to achieve better outcomes. Both pelvifemoral dysfunction and psychological factors that may affect the development and symptoms of AKP must be considered to identify therapeutic targets within the context of treatment. Patients presenting with AKP frequently respond well to load restriction that protects their knee and reduces pain during rehabilitation. Surgery should only be considered in very select cases. In a patient who has undergone previous patellar realignment surgery and experienced increased pain, iatrogenic medial patellar instability should be considered.Conclusions:The etiology of AKP is multifactorial, and several subpopulations of AKP patients exist and their treatment must be personalized. Normally, the focus is on the knee of a patient with AKP, and only that joint is examined. However, that focus can lead to overlooking other important etiological factors that may be present.

Patellar stabilization for combined medial and lateral patellar instability: a case report with technical note

Patellar stabilization for combined medial and lateral patellar instability: a case report with technical note

The Pie Crust Lateral Release Technique Compared to Traditional Lateral Release Techniques in a Cadaveric Study

Lateral patellar compression syndrome is a known cause of chronic anterior knee pain. For patients who have failed conservative treatment, arthroscopic lateral retinacular release is indicated. This procedure has been found to have potential sequelae on patellar instability with iatrogenic medial patellar instability being the most common problem. Recent studies have shown that the “pie crust” method of incision had positive results on patellar instability when implemented with total knee replacements. This study was designed to see if the pie crust method could be a potential arthroscopic surgical technique used for lateral retinacular releases in order to alleviate lateral compression. Using 15 cadaveric knees, the pie crust method was performed on 7 knees and the traditional releases were performed on 8 knees. The pie crust method was performed by using a horizontal stab 1cm in between stabs. K-wires were drilled into the knees to provide landmarks for measurement with digital calipers. Then lateral translation, medial translation, and patellar tilt laxity measurements of the knee cap were made on each of these knees using 0 Newtons, 22 Newtons, and 50 Newtons of force. This study found that the pie crust method increased lateral tilt and lateral retinacular laxity comparable to traditional lateral release techniques. However the pie crust method had a lower percent change of medial translation at both 22 N and 50 N (p value 0.0125, p value 0.011 respectively) compared to the traditional releases on patellar stability. The pie crust method improved tension and increased the lateral patellar tilt on the lateral patella with less subsequent medial instability compared to traditional releases. These results showed that the pie crust method could be a viable option for relieving the lateral patellar compression syndrome.