Conservative Treatment of Patellofemoral Subluxation

Use of anterior tibial translation in the management of patellofemoral pain syndrome in older patients: a case series

The currently most plausible pathophysiologic theory for the etiology of pain in patients with patellofemoral pain syndrome involves abnormal mechanical stress to the patellofemoral joint. At this time, there is no consensus nor is there a sufficient body of research evidence to guide management of patients with patellofemoral pain syndrome. This means that clinicians have to rely to some extent on a mechanism-based approach. Decreased quadriceps flexibility and muscular endurance have been identified as possibly relevant impairments in patients with patellofemoral pain syndrome. Surgical anterior translation of the tibial tuberosity with the Maquet procedure has a proven positive effect on patellofemoral contact forces. This case series studied the effects of a physical therapy management approach that included translating the tibia anteriorly while performing open kinetic chain quadriceps training and manual muscle stretching of the rectus femoris muscle. Outcome measures used included the numeric pain rating scale and goniometric measurement of rectus femoris muscle length in a standardized test position. Anterior tibial translation reduced pain during both interventions and also produced clinically and statistically significant pre- to post-intervention improvements in pain during manual muscle testing and rectus femoris length testing in addition to statistically significant pre- to post-intervention increases in rectus femoris muscle length. The results of this quasi-experimental study indicate the need for future experimental study. Future study should include functional in addition to impairment-based outcome measures, standardization and blinding for the rectus femoris muscle length test (should future researchers chose to again use this outcome measure), a pilot study establishing reliability of outcome measures collected by the therapist, younger subjects, and the collection of longer-term outcome data.

Vastus medialis: anatomical and functional considerations and implications based upon human and cadaveric studies

OBJECTIVE

To provide an electrophysiological and functional description of the vastus medialis (VM) and contrast it to an anatomical description.

METHODS

Motor points of all superficial portions of the quadriceps were identified on the dominant side of 8 human subjects and electrically stimulated to achieve a light contraction to trace and measure the orientation of the fibers. Electromyography of the VM was then recorded over 2 motor points during isometric and isokinetic maximum knee extensions. An independent laboratory dissected 39 cadaveric specimens focusing on fiber orientations and distal insertions of the VM.

RESULTS

Results revealed 5 motor points for the quadriceps: 1 point for the vastus lateralis, 1 point for the rectus femoris (RF), and 3 points for the VM. The 3 VM motor points suggest 3 separate groups of fibers: proximal (pf), median (mf), distal (df). Fiber orientations ranged from 45 degrees for VMpfs to 55 degrees for VMdfs. Motor point stimulation and anatomical dissection clearly showed that the VMpfs and VMmfs were inserted on a tendon common to the RF, whereas VMdfs were attached directly to the medial aspect of the patella. Furthermore, the VMpfs were more active (P < .05) than VMdfs during maximum knee extensions.

CONCLUSION

The anatomy, motor points, and electromyography clearly support an important distinction between the VMpfs and VMdfs. The role of the VMpfs would be one of assisting the RF in knee extension, whereas the VMdfs would track the patella medially without participating in knee extension. Because of these anatomical and functional differences, the VMpfs and VMdfs should be addressed very differently during quadriceps rehabilitation in patellofemoral dysfunctions.

Management of patellofemoral pain targeting hip, pelvis, and trunk muscle function: 2 case reports

STUDY DESIGN

Case report.

OBJECTIVE

To describe an alternative treatment approach for patellofemoral pain.

BACKGROUND

Weakness of the hip, pelvis, and trunk musculature has been hypothesized to influence lower-limb alignment and contribute to patellofemoral pain. Two patients who had a chief complaint of patellofemoral pain and demonstrated lack of control of the hip in the frontal and transverse planes during functional movements were treated with an exercise program targeting the hip, pelvis, and trunk musculature.

METHODS AND MEASURES

The patients presented in these 2 case reports did not exhibit obvious patellar malalignment or tracking problems; however, on qualitative assessment, both demonstrated excessive hip adduction, internal rotation, and knee valgus during gait and while performing a step-down maneuver. In addition, both patients exhibited weakness of the hip abductors, extensors, and external rotators, as demonstrated by hand-held dynamometry testing. Treatment in both cases occurred over a 14-week period and focused on recruitment and endurance training of the hip, pelvis, and trunk musculature. Functional status, pain, muscle force production, as well as subjective and objective assessment of lower-extremity kinematics during gait and a step-down maneuver were assessed preintervention and postintervention.

RESULTS

Both patients experienced a significant reduction in patellofemoral pain, improved lower-extremity kinematics during dynamic testing, and were able to return to their original levels of function. Gluteus medius force production improved by 50% in patient A and 90% in patient B, while gluteus maximus force production improved 55% in patient A and 110% in patient B. Objective kinematic improvements in the step-down task also were demonstrated in patient A.

CONCLUSION

Assessment and treatment of the hip, pelvis, and trunk musculature should be considered in the rehabilitation of patients who present with patellofemoral pain and demonstrate abnormal lower-extremity kinematics.

Activation of the VMO and VL during dynamic mini-squat exercises with and without isometric hip adduction

OBJECTIVE

the purpose of this study was to compare vastus medialis obliquus (VMO) and vastus lateralis (VL) activity while performing a mini-squat with and without isometric hip adduction.

DESIGN AND SETTING

a repeated measures within subjects design was used. Subjects performed two sets of three repetitions of a traditional mini-squat and a mini-squat with concurrent hip adduction (squeeze).

SUBJECTS

20 recreationally active subjects (10 men, 10 women age=28.10+/-5.91 years, height=170.94+/-11.03 cm, mass=72.32+/-16.66 kg) with no history of patellofemoral pain (PFP), quadriceps injury, or other knee injury participated in the study.

MEASUREMENTS

the EMG signal of the VMO and VL was recorded bilaterally during both exercises. EMG data were normalized to the maximal voluntary isometric contraction (MVIC) of the quadriceps produced during seated, isometric knee extension.

RESULTS

results of repeated measures ANOVA's revealed that the squeeze squat produced significantly greater VMO and VL activity than the traditional squat (p=0.02). For both the traditional and squeeze squats, intrasession reliability from the first to the second set was calculated using intraclass correlation coefficient (ICC) formula (3:1) bilaterally for both the VMO and the VL. All ICC values were greater than 0.9.

CONCLUSION

combining isometric hip adduction with a mini-squat exercise significantly increases the activity of the quadriceps. Performing mini-squats with isometric hip adduction will be beneficial to patellofemoral patients as they increase quadriceps activity, however, based on our data we cannot conclude that this exercise preferentially recruits the VMO. Further research is needed to determine the exact mechanism by which quadriceps function is altered.

Immediate surgical repair of the medial patellar stabilizers for acute patellar dislocation. A review of eight cases

An open surgical repair of the injured medial patellar stabilizers, including the vastus medialis obliquus muscle and the medial patellofemoral ligament, after acute patellar dislocation was studied in eight patients. At initial examination, all patients had tenderness over the adductor tubercle and a positive patellar apprehension sign. Four of eight patients had obvious ecchymosis over the adductor tubercle. Magnetic resonance imaging, diagnostic arthroscopy, and open surgical exploration documented injury to both the medial patellofemoral ligament and the origin of the vastus medialis obliquus muscle. In all patients, the torn muscle was retracted in an anterior and superior direction and an arthroscopic lateral release was performed followed by open primary repair of the medial patellofemoral ligament to the adductor tubercle and repair of the vastus medialis obliquus muscle to the adductor magnus tendon. Patients were evaluated postoperatively with the Kujala scoring questionnaire. The average follow-up was 3.0 years, with a minimum of 1.5 years. No patients experienced a recurrent dislocation. The average Kujala score was 91.9. Patients rated their return to athletic activity at an average 86% of their pre-injury level. The average subjective satisfaction was 96%. In appropriate cases of acute patellar dislocation, we recommend primary repair of the medial patellofemoral ligament and the vastus medialis obliquus muscle to avoid recurrent dislocation, chronic subluxation, pain, and disability.

Hamstrings and iliotibial band forces affect knee kinematics and contact pattern

Many clinical studies have emphasized the role of the hamstrings and the iliotibial band on knee mechanics, although few biomechanical studies have investigated it. This study therefore examined two hypotheses: (a) with loading of the hamstrings, the tibia translates posteriorly and rotates externally and the tibial contact pattern shifts anteriorly; furthermore, the changes in tibial kinematics alter patellar kinematics and contact; and (b) loading the iliotibial band alters the kinematics and contact pattern of the tibiofemoral joint similarly to loading the hamstrings, and loading the iliotibial band laterally translates the patella and its contact location. Five cadaveric knee specimens were tested with a specially designed knee-joint testing machine in an open-chain configuration. At various flexion angles, the knees were tested always with a quadriceps force but with and without a hamstrings force and with and without an iliotibial band force. The results support the first hypothesis. Hence, the hamstrings may be important anterior and rotational stabilizers of the tibia, a role similar to that of the anterior cruciate ligament. The results also support the second hypothesis, although the iliotibial band force had a smaller effect on the tibia than did the hamstrings force. Both forces also changed patellar kinematics and contact, demonstrating that these structures should also be considered during the clinical management of patellar disorders.

Patellofemoral disorders: a classification system and clinical guidelines for nonoperative rehabilitation

Patellofemoral disorders are among the most common clinical conditions managed in the orthopaedic and sports medicine setting. Nonoperative intervention is typically the initial form of treatment for patellofemoral disorders; however, there is no consensus on the most effective method of treatment. Although numerous treatment options exist for patellofemoral patients, the indications and contraindications of each approach have not been well established. Additionally, there is no generally accepted classification scheme for patellofemoral disorders. In this paper, we will discuss a classification system to be used as the foundation for developing treatment strategies and interventions in the nonsurgical management of patients with patellofemoral pain and/or dysfunction. The classification system divides the patellofemoral disorders into eight groups, including: 1) patellar compression syndromes, 2) patellar instability, 3) biomechanical dysfunction, 4) direct patellar trauma, 5) soft tissue lesions, 6) overuse syndromes, 7) osteochondritis diseases, and 8) neurologic disorders. Treatment suggestions for each of the eight patellofemoral dysfunction categories will be briefly discussed.

Patellofemoral malalignment

Anterior knee pain represents one of the most common musculoskeletal complaints of adolescents. It is a disorder in which there is broad clinical experience and yet it represents a difficult and frustrating entity for the athlete to endure and for the physician to treat. An appropriate clinical examination and selected diagnostic studies can define the diagnosis and the introduction of conservative therapy usually will correct the problem. Occasionally, surgical intervention is required, and debate remains as to the optimal techniques that should be used.

Long-term evaluation of the Elmslie-Trillat-Maquet procedure for patellofemoral dysfunction

We evaluated 55 knees in 51 patients after Elmslie-Trillat-Maquet procedures. The procedure involves medialization of the tibial tubercle on a distal pedicle and elevating the tibial tubercle anteriorly 10 mm with a local bone graft. At a mean followup of 74.2 months (range 13 to 196), all patients completed postoperative surveys and 38 underwent postoperative examinations. Subjectively, 9 knees (16%) had excellent results, 24 knees (44%) obtained good results, and 13 knees (24%) had fair results for a total of 84% improvement overall. Using Fulkerson's functional knee score, 19 knees (35%) had excellent results, 10 knees (18%) had good results, and 11 knees (20%) had fair results for a total of 73% improvement overall. A total of 24 knees (44%) required later screw removal. The most significant findings of this study include 1) an 84% overall subjective improvement in symptoms; 2) the findings that young patients without evidence of progressive osteoarthrosis and with patella instability as a primary symptom tend to have the most favorable outcome; and 3) 24 knees (44%) required later screw removal.

Patellar taping: a radiographic examination of the medial glide technique

The purpose of this study was to radiographically determine the effectiveness of the McConnell medial glide patellar taping technique. Twenty apparently healthy men, between ages 18 and 35, participated in this study. Subjects underwent a series of three radiographs in a modified Merchant view. First, a bilateral tangential view of the patellofemoral joints was taken to establish a baseline. Next, the same view was obtained with the experimental knees taped using the McConnell medial glide technique. Subjects then underwent a standardized exercise protocol to stress the tape and the accompanying knee structures. This was followed by a third view of the patellofemoral joints. Radiographs were measured using the Merchant congruence angle and analyzed statistically with dependent, mean difference tests. Results from this study indicate that the McConnell medial glide technique was effective in significantly moving the patella medially (P = 0.003), but that the tape was ineffective in maintaining this significance after exercise (P < 0.001). In 3 subjects (15%) of this sample, the tape was ineffective in moving the patella medially in any degree. One interesting finding was that exercise caused a statistically significant (P = 0.016) lateral shift from baseline in the control knees. This may suggest some clinical significance for patellar taping in preventing excessive lateral shift.