By Harvey S. Kohn, M.D.

Biographical Sketch

Dr. Kohn is an avid recreational athlete participating in running, tennis, golf and weight lifting. He is a 1970 graduate of Albert Einstein College of Medicine and of New York Medical College Orthopedic Residency. He specializes in arthroscopy and sports medicine.

Introduction

Knee pain is very common in recreational athletes. The knee is a central pivot area of the leg and, therefore, it bears the brunt of force, which generates leg support activities. As we age, the normal process is accentuated by any degenerative changes that have occurred.

Knee Anatomy

The knee consists of external muscles that generate power, protect the internal structures of the knee and connect the tibia to the femur bone. These muscles also incorporate the patella bone at the front of the knee, which helps protect the knee from injury and increases the efficiency of the muscles.

There are internal structures that guide and cushion movement. These consist of medial and lateral ligaments, anterior and posterior cruciate ligaments, menisci and the articular cartilage surface (hyaline cartilage).

The muscles are the dynamic forces that can be trained for efficiency by systematic weight resistance activity and by sports specific activities. That is, bikers have very large front thigh muscles and quadriceps muscles.

The internal structures, which connect the tibia to the femur, protect the knee from excessive side-to-side and front-to-back motion. These structures cannot be strengthened and are, therefore, known as static restraints. These guide motion and make precise bounding, jumping, running and changing directions quickly possible. The joint surface of hyaline cartilage allows smooth motion to occur between the femur and tibia. Injury or naturally occurring wear process can lead to pain and swelling of the knee.

The menisci are C-shaped fiber structures that cushion the knee during activities. The lateral meniscus lies on the outside of the knee. The medial meniscus lies on the inside of the knee between the femur and tibia bone. These can be injured by excessive stress such as twisting as in a fall or by cumulative wear over years of activity.

Specific knee conditions consist of:
1. Muscle tendon inflammation, pulls and tears
2. Ligamentous strains and tears
3. Tears to the menisci
4. Injuries or excessive wear to the joint surfaces including the patella

1. Muscle Tendon Injuries

The muscles act as a lever system to enable efficient motion to occur at the knee joint. Exceeding the strength of a muscle by a fall or sudden bend to the knee, as in stepping in a hole during running, a partial or complete tear can occur to the muscle or to the tendon. To avoid such injuries, a good strength and flexibility program can be worked on during the pre-season and such program guides are available from any athletic fitness facility. Warm up and stretching before an activity is most helpful in preventing injuries. If a partial tear or pull occurs, ambulation is painful, running is most difficult and medical care should be sought. A physician can assess muscle function and the degree of injury ascertained. An x-ray and MRI scan can assess the status of the bony structures and the muscle tendon structures. Protective weight bearing on crutches, a knee immobilizer and a possible recommendation for surgery for repair in the case of a complete rupture or tear can be made. With modern orthopedic techniques of minimal excision and accelerated rehabilitation, the athlete can be restored to recreational activities in a matter of months.

Patellar Tendonitis
Patella tendonitis is a local inflammation of the tendon attachment of the patella to the tibia bone. It is caused by overuse, causes pain during and after a workout and stiffness the next day. There is localized tenderness in this area and occasional swelling. Treatment consists of rest, ice, compression and elevation (RICE), decreased running activities including inclines, cross training (biking and water activities) as well as physical therapy.

This diminishes the localized inflammation and strengthens the muscle unit attached to the tendon. A band similar to a tennis elbow band can be placed just below the patella to diminish stress when returning to running. Anti-inflammatory medication may be helpful in decreasing the inflammation. Once the localized pain diminishes, return back to activities can be graduated. Very occasionally, surgery to trim and repair the inflamed tendon is necessary to return to running after rehabilitation of three to four months.

IT Band Syndrome
The iliotibial band lies on the outer side of the knee joint. This is a large flat band that can cause pain with excessive activities on uneven ground or occurs in the leg that is somewhat shorter than the opposite one. There is pain with palpation on the outer lateral knee (epicondyle) and a grating noise may occur with range of motion of the knee. These symptoms improve with diminished running and return with attempts to return running to the normal level. The treatment consists of diminishing the activity of workouts, cross training, stretching for the excessively tight iliotibial bands by physical therapist and orthotic or lift in shoe for shorter extremity. A steroid injection has proven to be very helpful as well as selective use of anti-inflammatory medications.

The use of good supportive running shoes, especially in someone who is a pronator, is important and use of orthotics in these when returning to running may be quite helpful.

For more refractory conditions, surgery to either release or lengthen this band may be necessary. Return to running after such an operation does not occur for a minimum of three to four months; however, cross training can be carried out after six to eight weeks.

2. Ligament Injuries

Ligaments can stretch or tear in recreational activities as mentioned previously. A fall during running on uneven terrain is the most common injury by outer twisting of the knee. There are three grades of injury, grade I to III, which are mild, moderate and severe. Mild sprains have less pain and swelling than severe ones. Treatment consists of RICE principle with immobilization in a brace for two to three weeks. More severe injuries will generally heal on their own after a longer period of immobilization for three to four weeks and brace protection for another three to four weeks before return to sporting activities. These injuries rarely, if ever, require surgery for repair of the ligament. Rehabilitation of the muscles following a period of immobilization is important in preventing recurrence and returning to biking and running activities.

ACL Injuries
ACL injuries have gotten significant publicity in national news media over the last few years. They are recognized more commonly now, not overlooked and under treated as they were one to two decades ago. They are unusual in runners and bikers except in crashes and falls and will be covered in a subsequent chapter.

3. TEARS OF THE MENISCI

The knee menisci are subject to stress through trauma, twisting and by cumulative stresses by virtue of years of recreational activities. The former will be covered in another chapter. The latter is not an uncommon problem in the middle-aged runner/biker. Until 20 years ago, this condition wasn’t well recognized except in obvious traumatic conditions and the runner/biker was left to fend for himself. Since then, with increasing recognition of this condition, diagnosis can be made and appropriate treatment rendered early on.

Symptoms consist of pain either on the inside or outside of the knee (depending on whether the lateral and medial meniscus is involved). With activities, locking, catching or a piece of meniscus that is torn and caught in the joint occurs during activities, as well as possible swelling. A diagnosis made by physical exam with localized pain can be confirmed by an MRI examination.

Treatment consists of physical therapy to strength the muscle groups, bracing to protect the knee joint from buckling, anti-inflammatory medication to decrease pain and swelling and diminishing activities (cross training). If pain, swelling, locking and catching persist, surgical arthroscopy to remove the torn piece of meniscus or to sew a tear of the meniscus back is very beneficial. The recovery period before returning to sports varies from two months for partial resection of the tissue to four months for repair.

4. Injuries & Wear to the Joint Surface

Chondromalacia
Chondromalacia of the patella occurs commonly in biking, walking and running activities, especially with hills and grade activities. Going down grades causes more problems than going up due to increasing strain on the kneecap by the quadriceps muscle. The condition is a cumulative one over time by virtue of running, biking and walking. It is more common in athletes who tend to be knock-kneed, in those with legs with increasing in toeing of the foot (pronation), and in those with an imbalance of muscles around the knee (weaker inner thigh muscles than outer thigh muscles).

This leads to cartilage breakdown on the undersurface of the patella and, therefore, pain in the front of the knee, stiffness before and after workouts, grating noise under the kneecap and possible swelling. The grating of this condition is from mild to moderately severe (grade I to IV).

Treatment consists of selective rest, cross training, avoiding hills, wearing a patella sleeve or stabilizing brace and physical therapy to balance the muscle forces across the knee. RICE principle is also followed as mentioned above and surgery to smooth the surface with an arthroscope as well as to rebalance the muscle forces may be necessary in counseling cases. The rehabilitation period to return to running and biking is at least eight to twelve weeks following such a procedure.

Osteoarthritis
Osteoarthritis is excessive wear to the surface of the femur and tibia bone that can be due to the normal aging process or excessive stresses from years of activities. This can also be due to malalignment of the lower leg. Symptoms consist of pain and swelling with activity. There may be direct tenderness over the affected area on examination.

Treatment consists of cross training, physical therapy to strengthen the muscles to relieve stress, anti-inflammatory medications, orthotics to help malalignment, supportive knee bracing and good supportive running shoes. In addition, glucosamine and chondroitin sulfate is available over-the-counter and has been proven beneficial in mild to moderate conditions, and for more refractory conditions, joint lubricant injections performed by your physician (hyaluronic acid such as Hyalgan) may be helpful symptomatically. Arthroscopic surgery to debride and smooth out the joint surfaces is not a long-term solution. Osteotomies, which cut the tibia and femur bone to correct malalignment, are used increasingly by orthopedic surgeons to relieve pain and slow the progression of changes to the joint surface. Total knee replacement for advanced conditions will relieve pain but will not return a runner back to his accustomed running activities but should allow this individual to return to recreational walking and biking activities.

Summary

In conclusion, prevention of injuries by good strengthening and stretching programs and early recognition and treatment of these can greatly diminish frustration and lead to early return to the injured athlete to his specific activities.