TttE NONSURGICAL TREATMENT OF PATELLOFEMORAL DISORDERS

RONALD P. GRELSAMER, MD

It is an orthopaedic truism that patellofemoral disorders can be treated nonsurgically in the vast majority of cases. The odds of a nonsurgical program being successful depend on the severity of the underlying condition and contingent on the adequacy and sophistication of the nonsurgical protocol. In this article, we review the main fea~res of the nonsurgical treatment of patellofemoral disorders. These include physical therapy (selective mobilization, stretching, strengthening, taping, modalities, feedback), bracing, medication, activity modification, and footwear adjustments. It benefits the orthopaedist to be familiar with these approaches, lest he or she perform unnecessary surgery. KEY WORDS: patella, pain, chondromalacia, treatment, nonoperative

Although it is true that most patients improve with nonsurgical treatment, it is my experience that orthopae- dists have little knowledge of what comprises a thorough nonsurgical approach. It is my opinion that your reading of this section makes you part of an elite minority, because most of your colleagues will ~ r n right to the surgery chapters.

It bears repeating that making the right diagnosis is paramountJ Although I believe that patella malalignment is very commonly missed, I also believe that many patients whose source of pain is mysterious are simply labeled as having "chondromalacia." The following diagnoses do not automatically come to the mind of the orthopaedist yet must be ruled out: inflammatory conditions, Lyme disease, neuromas, and referred pain (hip or spine). The patient must be examined for 'squinting' patellae (usually an indication of a disorder from the hip down to the foot) and for foot pronation (see orthotic section). Accordingly, the first step of a nonsurgical approach is the examination of the entire extremi~.

Most conditions can be addressed by nonsurgical means such as appropriate physical therapy, strengthening, stretch- ing, taping, bracing, nonsteroidal anti-inflammatory medi- cations (NSAIDs), activity modification, and the judicious use of injections.

PHYSICAL THERAPY

Not all forms of physical therapy will lead to improve- ment, and some will cause harm. The practitioner must, therefore, be specific in his or her recommendations.

The clinician should identify a therapist with knowledge of (or at least an interest in) patellofemoral disorders. The therapist should have the time to devote to such patients. Because therapy may not be cost-effective (in the short run,

From the Maimonides Medical Center, The Hospital for Joint Diseases and Beth Israel Medical Center, New York, NY.

Address reprint requests to Ronald P. Grelsamer, MD, Chief, Knee and Hip Reconstruction, Maimonides Medical Center, 927 49th Street, Brook- lyn, NY 11219.

Copyright © 1999 by W.B. Saunders Company 1060-1872/99/0702-0004510.00/0

when looked at from the therapist's point of view), the therapist may not be willing or able to get as thoroughly involved as he or she would like.

The knowledgeable therapist will look at the entire extremity in a way that should complement the orthopae- dist's examination. For example, in addition to the ortho- paedic testing for hamstring, quadriceps, and iliotibial band (ITB) tightness, the therapist will also assess the gluteus maximus. Because of its insertion onto the ITB, tightness of this muscle can naturally impact on the ITB itself.

S t r e t c h i n g

Stretching is a key component of physical therapy. In addition to stretching of the hamstrings, quadriceps, ilio- tibial band, and gastroc/soleus, the therapist can occasion- ally stretch the lateral retinaculum. For many patients, stretching itself leads to significant improvement.

Modalities

Modalities include heat/cold, ultrasound, and (steroid) iontophoresis. 2,3 These can be useful about the knee be- cause of the joint's relatively superficial location. Pain from inflamed tissues can be calmed with these modalities via mechanisms that are not yet fully appreciated.

S t r e n g t h e n i n g

Empirically, we know that quadriceps strengthening often leads to diminished patellofemoral pain. Because the vastus medialis obliquus (VMO) is the main dynamic medial stabilizer of the patella, finding so-called VMO- preferential exercises has been the holy grail of physical therapists. As of this writing, it is still not clear to what extent any such exercises exist. 4

Strengthening can be done via closed-chain or open- chain exercises. In the former case, the patient's feet are pressed against the floor or some other object (as in leg presses) and in the latter case, the feet dangle free (as in leg extensions and leg curls). However, it is not enough for a muscle to be strong, it must also fire in the appropriate sequence, ie, in coordination with the surrounding units. I

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do not believe that open-chain exercises address this important issue, because they do not simulate real-life activities (except perhaps kicking). The issue of whether open chain exercises lead to nonphysiological stresses on the patellar articular cartilage as the knee nears extension is unresolved. On one hand, the contact area on the patella gradually diminishes as the knee extends, and the quadri- ceps force increases. These factors tend to increase contact stress. On the other hand, the percentage of the joint reaction force relative to the quadriceps force also dimin- ishes as the knee extends (the vector of the joint reaction force comes closer and closer to being perpendicular to that of the quadriceps force). This tends to minimize contact stress. Closed-chain exercises at least simulate some basic activities of daily living such as getting up from a chair and going up and down stairs.

If a patient wishes to engage in a specific activi~, exer- cises that replicate that activity as much as possible should be sought. According to the concept of "feed-forward" the muscle groups, muscles, when called upon to perform a specific activity, deliver a learned response with regard to the magnitude and sequence of muscle fiber firing. 4,5 This learned response can be acquired through sophisticated therapy (see Surface Electromyography section).

TAPING The concept of taping is predicated on the premise that pulling on the skin can exert clinically significant traction on the patella. Investigators have sought to prove or disprove this concept through various imaging modalities, but I believe that they miss the point: imperceptible changes in the position of the patella can lead to significant changes in joint pressure. The absence of any visible change in the position of the patella on imaging studies is, therefore, irrelevant. Of greater significance is the fact that many patients feel immediate relief with taping. In classic malalignment, in which the patella is laterally tilted and /or displaced, taping goes from lateral to medial in an effort to untilt the patella and /or pull it closer to the center of the trochlea (Fig 1). There are multiple variations on this theme. For example, if the patella is believed to be overly

Fig 1. Taping can be used to pull the patella medially. It is possible for the patient to feel better, even in the absence of detectable changes in patellar position, (Reprinted with per- missiond °)

Fig 2, If pain is believed to be attributable to impingement of the inferior pole into the fat pad, taping can be adjusted accordingly, (Reprinted with permission, TM)

flexed, ie, pushing into the fat pad, taping can also be applied from distal to proximal to lift the inferior pole of the patella off the fat pad (Fig 2). In my opinion, pain relief from taping increases the liklihood that the patient's pain is coming from some form of patellar malposition.

Patients can learn to tape their own knees. The main drawback to taping is the eventual irritation of the skin. This happens at a variable point in time from patient to patient.

Surface Electromyography As explained by Kasman, 6,7 surface electromyography (SEMG) is "the recording of muscle action potentials with skin surface electrodes." It allows the therapist to monitor not just the amplitude of muscle contractions, but also the timing of muscle firing. It is noninvasive and painless. The equipment has been miniaturized to the point that it is portable and can readily be incorporated into an office or even a home. The use of SEMG during strengthening exercises provides the patient with ultrasensitive feedback with regard to the activity of specific muscle groups. For example, the patient can experiment with various proto- cols until the one that recruits the desired muscle(s) is found. In the case of patients with patellofemoral malalign- ment, efforts are directed toward the VMO. Interestingly, the recruitment timing of the VMO can be normal in open-chain activities but be abnormal in closed-chain activities. This is another reason to emphasize closed-chain training.

BRACING Like everything else about the patella, the use of bracing in this setting remains controversial. The stated purpose of bracing is to pull or push the patella into better alignment. There are two controversies: does bracing accomplish this goal and can braces help via some other mechanism?

As with taping, investigators have used radiographs and computerized imaging to determine if bracing accom- plishes this goal. As with taping, the issue is, to a certain extent, irrelevant. Imperceptible changes can lead to clini- cal improvement.

I see braces falling into two categories--passive and

66 RONALD P. GRELSAMER

active. The passive variety features a lateral buttress to keep the patella centered. The active kind pulls the patella medially. In the classic passive brace, there is a "doughnut" hole in the middle with a built-up periphery (eg, Genutrain [Bauerfeind USA, Kennesaw, GA] ). The active braces come in many varieties. One brace uses taping (On-Track, San Diego, CA), another comes with a T-shaped strap that is attached with Velcro (Velcro USA, Inc, Manchester, NH) to the brace (Cropper, Ashland, OR), another combines the central hole with medially-directed straps (Palumbo, Vi- enna, VA), and another is composed of a long strap wrapped around the knee and affixed to circumferential pads above and below the knee (Tru-Pull [DePuy Orthotec, Warsaw, IN]).

If the patella is severely tilted, it will slip under the peripheral build-up of a passive brace. I believe that passive braces are, therefore, most effective in patients with patella alta and no tilt. The Tru-Pull- and Cropper- type braces are most effective in patients with lateral displacement without severe tilt, because a patella with severe tilt will also slip under the lateral aspect of the brace. The On-Track is the most sophisticated (or compli- cated, depending on how you see it) and is intended for patients with considerable tilt (with or without lateral displacement).

Using another approach, straps are placed across the patellar tendon (eg, Cho-Pat [Cho-Pat, Inc, Hainesport, NJ]). It is not clear how this helps patients, but some patients unequivocally feel better with this. I have to assume that by pushing down on the tendon it alters the position of the patella enough to unload the painful areas. I would not expec~ this to work in patients with an inflamma- tion of the fat pad or lesions near the distal portion of the patella, and I would expect it to work best when the painful areas are near the proximal part of the patella. I don't know of any study that has examined this.

A distinctly different type of brace is the Empi (St. Paul, MN) type of device. This is a long leg brace not meant to be a first-line brace for the average patient with patellofemo- ral pain. It is hinged and spring-loaded. As the knee is flexed, the brace supports the patient. The quadriceps muscles, therefore, do not work as hard, the patellofemoral joint reaction forces are diminished, and pain is controlled.

MEDICATION

NSAIDs are the hallmark of medication therapy. A full discussion of these medications is beyond the scope of this article. It should be noted, however, that NSAIDs can be classified according to their specific mechanism of action. If one NSAID does :not work, I recommend trying a medica- tion that is not in the exact same category. For example, ibuprofen and naproxen are in the same category. If one did not work on a given patient I would switch to an NSAID from another category (eg, diclofenac).

When cost is a concern, certain NSAIDs have been on the market for more than ten years and their generic equiva- lent is available. These include naproxen, ibuprofen, diclo- fenac, and sulindac.

If anti-inflammatory medications are prescribed for any length of time, laboratory studies should be obtained every 3 to 4 months to assess kidney, liver, and marrow function.

NSAIDs on the horizon include the COX 1 and COX 2 inhibitors, which are associated with fewer gastrointestinal side effects than current anti-inflammatories.

INJECTIONS

Injections are of limited value in the treatment of patello- femoral malalignment. They can be of use, however, in sorting through the differential diagnosis. For example, a lidocaine injection into the distal iliotibial band can help diagnose iliotibial band tendinitis. Injecting Iidocaine in the knee joint helps the doctor determine whether the knee is the origin of file pain, or if pain is referred down to the knee).

ACTIVITY MODIFICATION

This is both the easiest and most difficult approach. It is logical to eliminate the activities that cause pain. Patients, however, visit the doctor specifically to go back to these activities. Nevertheless, in select cases, it is reasonable to bring up the subject of activity modification. Some (rare) patients will actually be relieved to have been "ordered" to stop an activity.

SHOE WEAR AND ORTHOTICS

Abnormal foot mechanics can cause or exacerbate knee pa inY A worn shoe can lead to abnormal stresses in the lower extremity, even in the presence of normal anatomy. One of the simplest things an athlete with knee pain can do is check his or her shoes and replace them as necessary. Patients with abnormal foot mechanics require a higher level of attention. For example, an athlete who pronates will benefit from an arch support (in an athlete it should be a full length orthotic8). It will protect his or her foot from the effects of chronic flat feet and may help relieve knee pain. Pronation leads to internal rotation of the lower leg and a valgus moment at the knee, and this might place undue stress in and about the patella. Though this is a plausible explanation for the correlation between foot pronation and knee pain, it has not been proven conclu- sively.

CONCLUSION

As biological carpenters, we orthopaedists are most inter- ested in surgically correcting everything that is broken or out of place. However, patients with patella malalignment need not be perfectly realigned to feel better. Except for patients with the most severe forms of malalignment, most patients with patellar pain will improve with the modali- ties listed above.

REFERENCES

1. Grelsamer RP, McConnell J (eds): The Patella--A Team Approach. Gaithersburg, MD, Aspen, 1998, pp 43-74

NONSURGICAL TREATMENT OF PATELLOFEMORAL DISORDERS 6 7

2. Kahn J, Milazzo W, Mongulla L: Panelists get a charge out of iontophoresis. Biomechanics, 1998, pp 25-29 (roundtable discussion)

3. Kahn J: Principles and Practice of Electrotherap3~ 3rd ed. New York, Churchill Livingstone, 1994

4. Grabiner M, Koh T, Draganich L: Neuromechanics of the patellofemo- ral joint. Med Sci Sports Exerc 26:10-21, 1994

5. McConnell J: Conservative management of patellofemoral problems, in Grelsamer RP, McConnell J (eds): The Patella--A Team Approach. Gaithersburg, MD, Aspen, 1998, pp 137-165

6. Kasman GS, Cram JR, Wolf SL: Clinical Applications in Surface Electromyography: Chronic Musculoskeletal Pain. Gaithersburg, MD, Aspen, 1998

7. Kasman GS: Surface electromyography and patellofemoral dysfunc-

tion, in Grelsamer RP, McConnell J (eds): The Patella--A Team Approach. Gaithersburg, MD, Aspen, 1998, pp 137-164

8. McNerney J: BiomechanicaI management of patellofemoral pain and dysfunction with foot orthotic devices, in Grelsamer RP, McConnell J (eds): The Patella--A Team Approach. Gaithersburg, MD, Aspen, 1998, pp 177-227

9. Donatelli R, Hurlburt C, Conaway D, et al: Biomechanical foot orthotics: A retrospective study. J Orthop Sports Phys Ther 10:205-212, 1988

10, McConnell J: Conservative management of patellofemoral problems, in Grelsamer RP, McConnell J (eds): The Patella--A Team Approach. Gaithersburg, MD, Aspen, 1998, p 124

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