Open or arthroscopic lateral release. Indications, techniques, and rehabilitation

A Review of the Lateral Patellofemoral Joint: Anatomy, Biomechanics, and Surgical Procedures

The lateral patellofemoral joint soft tissues contain key structures that surround and balance the joint. These structures can affect joint tracking, stability, and force distribution. It is important to understand the lateral patellofemoral anatomy and biomechanics, and their relationship with patellofemoral instability, anterior knee pain, and osteoarthritis. Lateral-sided surgical procedures such as lateral release, lateral retinacular lengthening, and partial lateral patellar facetectomy can be useful in the treatment of such patellofemoral problems.

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

INTRODUCTION

Lateral 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 METHODS

80 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.

RESULTS

There 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.

CONCLUSION

Both 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.

Patellofemoral kinematics in patellofemoral pain syndrome: The influence of demographic factors

Due to the multifactorial nature of patellofemoral pain, it is often difficult to identify an individual patient's exact cause of pain. Understanding how demographic variability influences these various factors will support improved consensus in regards to the etiology of PF pain. Thus, in this retrospective study, we tested the hypothesis that sex, height, weight, body mass index (BMI), and age influence the determination of between-groups differences in PF kinematics. We included 41 skeletally mature patients with patellofemoral pain and 79 healthy controls. Three-dimensional patellofemoral kinematics were quantified from dynamic magnet resonance images. We ran multiple regression analyses to determine the influence of demographic covariates (age, sex, height, weight, and BMI) on patellofemoral kinematics. Patellar shift was significantly influenced by weight (p = 0.009) and BMI (p = 0.009). Patellar flexion was influenced by height (p = 0.020) and weight (p = 0.040). Patellar tilt and superior displacement were not influence by demographic variables. Age and sex did not influence kinematics. This study supports the hypothesis that demographic parameters influence PF kinematics. The fact that weight, a modifiable measure, influences both patellar shift and flexion has strong implications for future research and clinical interventions. Clinically, weight loss may have a dual benefit of reducing joint stress and maltracking in patients who are overweight and experiencing patellofemoral pain. The influence of key demographics on patellofemoral kinematics, reinforces the clear need to control for population characteristics in future studies. As such, going forward, improved demographic matching between control and patient cohorts or more advanced statistical techniques that compensate for confounding variables are necessary.

The Effect of Concomitant Arthroscopic Lateral Retinacular Release on Postoperative Patellar Position and Orientation in Open Wedge High Tibial Osteotomy

Purpose

The purpose of this study was to evaluate the effect of concomitant arthroscopic lateral release (LR) in open wedge high tibial osteotomy (OWHTO) by comparing the pre- and postoperative radiological parameters of patellar position and orientation.

Materials and Methods

The study was comprised of 19 knees undergoing OWHTO and concomitant LR and 18 knees undergoing OWHTO alone. Radiological parameters for patellar position and orientation included the Caton-Deschamps index (CDI), Blackburne-Peel index (BPI), patellar tilting angle (PTA), patellar lateral shift (PLS), and patellofemoral distance (PFD), which were evaluated in the preoperative period and at one year after surgery.

Results

Patellar height was significantly reduced after surgery as indicated by the decrease in BPI (p=0.03) in the OWHTO/LR group, and decrease in CDI (p=0.03) and BPI (p=0.04) in the OWHTO alone group. PTA and PLS were significantly reduced after the combined OWHTO/LR procedure (p=0.04 and p=0.04, respectively). By contrast, no significant changes were detected when isolated OWHTO was performed.

Conclusions

OWHTO induced a postoperative decrease in patellar height in both groups. Regarding the change in patellofemoral alignment, concomitant LR in OWHTO significantly decreased lateral patellar tilt and shift, while no significant difference in those parameters were noted in the OWHTO alone knees.

Evaluation of patello-femoral alignment by CT scans: interobserver reliability of several parameters

Patello-femoral malalignment (PFM) is a common cause of disability often related to patello-femoral syndrome (PFS). Several causes have been taken into account; a proper diagnosis requires instrumental imaging and a methodical evaluation of different parameters. The aim of the present study was to identify the most reliable parameters for measuring patello-femoral and inferior limb alignment by CT. Twenty randomly selected patients suffering from PFS for a total of 40 knees were studied by static CT scans in order to assess patellar tilt, patellar displacement, patellar and trochlear morphology and inferior limb alignment. All known parameters were measured; the variability of the measurements between observers was evaluated by boxplots, Pearson's correlation coefficients, and infraclass correlation coefficient [ICC(2,1)] based on a two-way random effect model. Bland-Altman mean differences and 95 % limits of agreement were computed for each pair of measurements. Patellar tilt parameters appeared equally reliable; patellar displacement is best measured with BoTot that showed an ICC of 0.889; morphology is best measured with WibergTot, with an ICC of 0.862; lastly, for the inferior limb alignment parameters' analysis, FTV outperformed the others in terms of reliability. The present study allowed us to select a limited number of reliable parameters in the evaluation of patello-femoral and inferior limb alignment. The use of these parameters may also result in a more reliable comparison of studies on PFM and in a better evaluation of the treatment outcomes.

Complications in brief: Arthroscopic lateral release

Arthroscopic lateral release refers to an arthroscopic procedure that incises the lateral stabilizing structures of the patella, in particular, the lateral retinaculum. The lateral retinaculum attaches the lateral patella to the lateral femoral epicondyle, the iliotibial band, and the anterolateral tibia. Arthroscopic lateral release rarely is performed as an isolated procedure and rather is generally performed in combination with medially based stabilization procedures to more effectively allow for medial realignment. The procedure is relatively simple and straightforward, but, if not done for the appropriate indications or if done technically poorly, either it will not achieve the desired result or it may result in additional pain, instability, and weakness. This In Brief article provides an overview of potential complications of lateral release.

The effect on patellofemoral joint stability of selective cutting of lateral retinacular and capsular structures

Patient selection for lateral retinacular release (LRR) and its efficacy are controversial. Iatrogenic medial subluxation can occur with inappropriate LRR. The aim of this study was to determine the reduction in patellofemoral stability with progressively more extensive LRR. The force required to displace the patella 10mm medially and laterally in nine cadaveric knees was measured with and without loading of the quadriceps and iliotibial band. The knee was tested intact, then after progressive release beginning proximal to the patella (PR), the mid-level between the proximal and distal limit of the patella (MR) where the fibres are more transverse, then distally till Gerdy's tubercle (DR) and finally the joint capsule (CR). Both medial and lateral stability decreased with progressive releases, larger for the medial. The MR caused a significant reduction of lateral stability between 30 degrees and 90 degrees of knee flexion. There was an 8% reduction in medial stability at 0 degrees flexion with a complete LRR (DR). A comparable reduction in medial stability in the loaded knee at 20 degrees and 30 degrees flexion was obtained with MR alone, with no further reduction after DR. A capsular release caused a further reduction in medial stability at 0 degrees and 20 degrees and this was marked in the unloaded knee. In extension, the main lateral restraint was the joint capsule. At 30 degrees flexion, the transverse fibres were the main contributor to the lateral restraint.

Long-term functional outcome after lateral patellar retinacular release in adolescents: an observational cohort study with minimum 5-year follow-up

BACKGROUND

Lateral patellar retinacular release has been recommended for patients with patellar tilt, tight lateral retinaculum, patellar subluxation, patellar dislocation, and patellofemoral pain. Studies of long-term outcomes after lateral release are limited, especially for differing indications.

HYPOTHESIS

Adolescents do well after lateral retinacular release in the 5- to 22-year time frame.

METHODS

Patients having undergone lateral retinacular release between the years of 1981 and 1999 were contacted. Evaluation was by the Cincinnati and Lysholm scales and by level of satisfaction and need for reoperation.

RESULTS

One hundred forty knees were studied. Mean age at operation was 15.4 years (SD, 2.7 years). Average follow-up was 8.5 (SD, 4.1 years; range, 5.2-22.5 years). Twenty-five patients had needed reoperation, indicating failure of the index operation. Kaplan-Meier survivorship was 78% at 15 years. Cincinnati and Lysholm scores indicated well-functioning knees in those not requiring reoperation. Overall satisfaction improved as time from operation increased. Comparisons were made between the group requiring reoperation and those who did not. Focus was placed on knees with patellar maltracking or tilt versus patellar instability and between males and females. No differences were found among groups for reoperation rate, level of satisfaction, average Lysholm score, or average Cincinnati score. There were no differences in demographics or outcome measures between patients with patellar instability and those with tilt. Instability patients trended toward higher reoperation rates than did tilt patients, but the difference was not significant. There were no differences between males and females.

CONCLUSION

The majority of patients are satisfied with their knee 5 to 22 years after lateral patellar retinacular release and scored well on questions rating knee health and function.

Locked lateral patella dislocation with generalized ligamentous laxity after arthroscopic lateral release of the knee

We describe the case of a 14-year-old boy with patellar instability on both sides resulting from ligamentous hyperlaxity and dysplasia of the lateral femoral condyle who had previously undergone an arthroscopic lateral release as well as plication of the medial capsule. The patient presented to our clinic 2 years after surgery with a locked lateral patella dislocation on the left side. The surgical correction involved a substantial open lateral release including an excision of the scar tissue and stabilization of the patella in the patellofemoral groove by tibial tubercle medialization and plication of the medial capsule. Six months after surgery, the patient achieved a Lysholm score of 90 points and clinical examination indicated a stable knee with a centralized patella without any evidence of subluxation or dislocation. Open lateral release with partial resection of the lateral retinaculum, medial reconstruction, and tibial tubercle osteotomy was the procedure of choice in this patient with habitual patella dislocation caused by generalized ligamentous laxity.

Patellofemoral syndrome: diagnostic pointers and individualized treatment

Most patients who have patellofemoral syndrome can be successfully treated once contributing factors are identified during history taking and physical examination. After pain and inflammation are treated, patients are encouraged to start activities that do not provoke pain. Exercise programs should be implemented that address underlying strength and flexibility deficits. Return to play primarily relies on advancement of pain-free activity, with some allowance for patients' competitive goals. Patients remaining symptomatic after compliance with a structured rehabilitation program or those with indicators of other intra-articular pathology should be referred to an orthopedist.

A modified test for patellar instability: the biomechanical basis

OBJECTIVE

(1) Determine if displacement of the patella in a distal lateral direction results in a more sensitive method to show deficiency of the medial patellofemoral ligament (MPFL), the primary restraint to lateral patellar dislocation, than the traditional patellar apprehension test in a direct lateral direction. (2) Determine objective criteria for defining a positive patellar instability test rather than subjective evaluation of apprehension.

DESIGN

In vitro biomechanical study.

SPECIMENS

Ten above-the-knee amputation specimens.

MAIN OUTCOME MEASURES

Force-displacement curves with direct lateral patellar displacement were compared with curves with distal lateral patellar displacement before and after sectioning the MPFL.

RESULTS

After dividing the MPFL, average terminal restraining force to distal lateral patellar displacement declined by 53% (P=0.024), but force declined only by 30% (P=0.09) with lateral displacement. The greatest difference in terminal slope (eg, end point) was with the MPFL intact with lateral displacement compared with distal lateral displacement with the ligament divided (P=8.67x10(-5)). The terminal slope declined after ligament division with lateral (P=0.07) and distal lateral patellar displacement (P=0.09).

CONCLUSION

Displacement of the patella in a distal lateral direction is a more sensitive maneuver to detect disruption of the MPFL, the primary soft tissue restraint, than with traditional lateral displacement. With the knee flexed 30 degrees and patella displaced 2 cm, objective criteria for a positive patellar instability test include greater ease of patellar translation and a softer end point compared with a normal, contralateral knee.

Complications of thermal energy in knee surgery--Part I

The use of thermal energy in knee surgery has many potentially exciting and useful applications. There is a growing body of literature that demonstrates the effects of these energy probes on different types of tissue. When contemplating the use of these surgical interventions in patients, it is important to recognize the potential limitations and complications that may arise.

Vastus medialis electrical stimulation to improve lower extremity function following a lateral patellar retinacular release

STUDY DESIGN

A single-case study design.

OBJECTIVES

To examine the effect of electrical stimulation of the vastus medialis muscle on stiffness, pain and function for a patient with delayed functional progress following a lateral patellar retinacular release.

BACKGROUND

Five months after an arthroscopic lateral patellar retinacular release, the patient, although highly motivated, had made little progress using routine exercises and taping.

METHODS AND MEASURES

An electrical stimulation program producing approximately 300 contractions daily of the vastus medialis muscle was implemented. The electrical stimulation applied for 33 of the 36 days was a rectangular and balanced biphasic pulse of 625-micros duration, 70-Hz frequency, 8-second peak on-time, 3-second off-time, 1-second ramp-up, and 0.5-second ramp-down. Objective measures of stair climbing and hopping, together with the subjective measure of therapist-palpated superomedial patella displacement force, were recorded for each treatment visit. Other subjective measures were the patient's daily recordings of knee pain and stiffness.

RESULTS

Patient-reported stiffness reduced rapidly as the actual and cumulative number of daily contractions of the vastus medialis muscle increased. After 8 days of electrical stimulation, the patient was able to ascend stairs unassisted and after another 21 days to hop unsupported.

CONCLUSIONS

Stiffness rapidly reduced and function started to improve once the electrical stimulation program was implemented. Recovery during the 36 days of treatment with electrical stimulation was greater than during the previous 5 months using other methods. Compliance was not an issue, nor was muscle soreness.

Diagnosis and treatment of patients with patellofemoral pain

The patient-athlete with patellofemoral pain requires precise physical examination based on a thorough history. The nature of injury and specific physical findings, including detailed examination of the retinacular structure around the patella, will most accurately pinpoint the specific source of anterior knee pain or instability. Radiographs should include a standard 30 degrees to 45 degrees axial view of the patellae and a precise lateral radiograph. Nonoperative treatment is effective in most patients. Prone quadriceps muscle stretches, balanced strengthening, proprioceptive training, hip external rotator strengthening, patellar taping, orthotic devices, and effective bracing will help most patients avoid surgery. When surgery becomes necessary, indications must be specific. Lateral release is appropriate for patella tilt (abnormal rotation). Painful scar or retinaculum, neuromas, and pathologic plicae may require resection. Proximal patellar realignment may be accomplished using arthroscopic or a combined arthroscopic/mini-open approach. Symptomatic articular lesions and more profound malalignments may require medial or anteromedial tibial tubercle transfer. Clinicians should be particularly alert for symptoms of medial subluxation in postoperative patients and should use the provocative medial subluxation test followed by lateral displacement patellar bracing to confirm a diagnosis of medial patellar subluxation. This problem may be corrected in most patients using a lateral patellar tenodesis. Current thinking emphasizes precise diagnosis, rehabilitation involving the entire kinetic chain, restoration of patella homeostasis, minimal surgical intervention, and precise indications for more definitive corrective surgery.

Predicting physical therapy visits needed to achieve minimal functional goals after arthroscopic knee surgery

STUDY DESIGN

Retrospective, cross-sectional regression modeling.

OBJECTIVE

To predict physical therapy visits following arthroscopic knee surgery.

BACKGROUND

The number of physical therapy visits required to achieve a set of specific minimal-level goals (full knee extension, straight leg raise, normalized gait pattern, bicycle pedaling, and independent home exercises) that are related to decreased complication rates has not previously been modeled.

METHODS AND MEASURES

A multiple regression model to predict postoperative physical therapy visits was developed using subject demographics and 2 simple clinical measures, degree of straight leg raise lag and total range of motion. All data were collected from 148 patient charts. Model validity was examined by the predicted residual sum of squares technique and a second independent sample of 157 charts.

RESULTS

Diagnosis group, surgery group, and range of motion were the significant variables predicting visits in the final model (R2 = 0.384). Results of model validation analyses using predicted residual sum of squares technique (R2 = 0.346) and the second set of data (R2 = 0.282) were satisfactory. Analysis of residuals (difference of observed and predicted visits) showed prediction of the number of physical therapy visits within 3 visits for approximately 75% of the cases in both sets of data.

CONCLUSIONS

Using the model to predict physical therapy visits following arthroscopic knee surgery was more accurate than using diagnosis alone, except for lateral retinacular release. This study demonstrates how regression models could be used to explain variance in physical therapy visits for a given set of minimal functional goals.