Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Job Classification

In most duration tables, five job classifications are displayed. These job classifications are based on the amount of physical effort required to perform the work. The classifications correspond to the Strength Factor classifications described in the United States Department of Labor's Dictionary of Occupational Titles. The following definitions are quoted directly from that publication.

Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Ruptured Quadriceps Tendon


Related Terms

  • Extensor Mechanism Disruption
  • Knee Tendon Rupture
  • Quadriceps Tendon Tear

Differential Diagnosis

Specialists

  • Orthopedic (Orthopaedic) Surgeon
  • Physiatrist (Physical Medicine and Rehabilitation Specialist)
  • Physical Therapist
  • Sports Medicine Physician

Factors Influencing Duration

Duration depends upon severity of the injury, type of treatment, job requirements, and any injury or treatment complications.

Medical Codes

ICD-9-CM:
727 - Other Disorders of Synovium, Tendon, and Bursa
727.6 - Rupture of Tendon, Nontraumatic
727.65 - Rupture of Tendon, Nontraumatic, Quadriceps Tendon
844 - Sprains and Strains of Knee and Leg
844.8 - Sprains and Strains of Knee and Leg, Other Specified Site

Overview

A ruptured quadriceps tendon (extensor mechanism injury) involves the partial or complete tearing of the fibrous attachment (tendon) for the quadriceps femoris muscle group. The quadriceps tendon attaches the quadriceps muscles to the kneecap (patella), and the patella is in turn attached to the tibia via the patellar tendon. Both the quadriceps and patellar tendons comprise a major part of the knee extensor mechanism. Quadriceps tendon ruptures occur infrequently and most often are associated with degenerative changes in the knee extensor mechanism, systemic disease, and advanced age.

Quadriceps tendon ruptures usually occur in only one knee (unilateral) and can be complete or partial. Quadriceps tendon ruptures that occur in both knees (bilateral) are usually related to systemic disease. A complete rupture results in the complete loss of muscle function and the inability to stand or walk. Quadriceps tendon ruptures usually occur close to the proximal patella and tend to transverse the tendon, often progressing diagonally into the medial and/or lateral retinaculum. A complete rupture of the quadriceps tendon from the bone is called a tendon avulsion injury.

The cause of quadriceps tendon rupture is typically a single traumatic accident, usually involving a rapid eccentric quadriceps muscle contraction with a planted foot and partially flexed knee, or from a direct fall onto a flexed knee. Quadriceps tendon rupture also may occur secondary to direct trauma or a laceration to the tendon. Patellar (kneecap) dislocation may accompany quadriceps tendon rupture.

Incidence and Prevalence: Unilateral quadriceps tendon ruptures are infrequent but occur 15 to 20 times more frequently than bilateral ruptures (Hyman). Older individuals are more likely to have complete ruptures; young athletes are more likely to experience partial ruptures (Lyle).

Source: Medical Disability Advisor



Causation and Known Risk Factors

The vast majority (88%) of quadriceps tendon ruptures occur in individuals older than 40 years of age (Gerbino). Individuals who have degenerative changes (tendinopathy) of the quadriceps tendon are at greater risk. Individuals younger than 40 years of age who participate in running and jumping sports are at increased risk for certain types of quadriceps tendon rupture (Lyle). Quadriceps tendon ruptures are more common in males than females (Lyle).

Individuals with systemic disease such as diabetes mellitus, gout, chronic renal failure, leukemia, rheumatoid arthritis, systemic lupus erythematosus, tumors, or infection are at increased risk for quadriceps tendon rupture. Those who are obese or who abuse steroids also are more prone to quadriceps tendon rupture. Other risk factors include surgery-related (iatrogenic) rupture during total knee replacement, meniscectomy, lateral release, or anterior cruciate ligament (ACL) reconstruction.

Source: Medical Disability Advisor



Diagnosis

History: The individual may report a tearing sensation or hearing an audible "pop" followed by a sharp, sudden pain in the knee. The individual may report having fallen as a result of the rupture. Individuals with a partial rupture will have severe weakness and inability to extend the knee, and report great difficulty moving from sitting to standing, weight bearing, walking, or climbing stairs. Individuals with a complete rupture will be unable to stand or walk.

Physical exam: The thigh and knee may exhibit swelling (edema) and tenderness along with bruising (ecchymosis) or a laceration at the knee. There may be a palpable gap detectable above the patella. The individual may demonstrate an extension lag when asked to hold a straight leg raise against gravity (partial rupture), or be completely unable to lift the leg when attempting the straight leg raise (complete rupture). If the rupture is partial, the individual may be able to hold the knee in full extension but will be unable to straighten the knee against gravity from a flexed position.

Tests: Diagnosis of a ruptured quadriceps tendon usually is based on individual history and the physical exam. Diagnostic tests usually are not necessary for complete quadriceps tendon ruptures following acute injury, although arthrography may be used to further evaluate complete ruptures. If a complete quadriceps tendon rupture has occurred, an abnormally low patella (patella baja) may be observed. Once the acute phase of the injury is past, a partial rupture can be difficult to diagnose and may require plain x-rays, ultrasound, or MRI. Investigation of bilateral quadriceps tendon rupture likely will include laboratory tests to detect any relevant underlying conditions. Laboratory tests may also be done in cases of unilateral rupture in otherwise healthy individuals.

Source: Medical Disability Advisor



Treatment

Partial ruptures may be treated nonoperatively (conservatively) or surgically. Conservative treatment begins with rest, ice, compression, and elevation (RICE). The knee is then immobilized in extension for 4 to 6 weeks. Flexion and strengthening exercises follow and progress gradually.

Complete quadriceps tendon ruptures require surgery. Surgical treatment involves either direct tendon reattachment to the patella, or a tissue augmentation technique to lengthen a retracted tendon in order to reattach it to the bone. If the tendon requires lengthening, a tendon graft (autograft; allograft) may be used. The tendon is sewn back into place with sutures, although pullout wires may also be used to stabilize the repair. Cylinder casting of the leg or a knee immobilizer brace is used postoperatively to support the repair.

Source: Medical Disability Advisor



Prognosis

Prognosis is good for surgical repair of acute complete and partial quadriceps tendon ruptures if treatment begins immediately. However, delayed surgical repair of ruptured quadriceps tendons may result in increased complications due to the retraction of the tendon by quadriceps muscle spasm (Hyman). This may result in permanent fibrosis of the muscle, resulting in limited power and mobility. Many individuals are unable to return to their pre-injury activity levels and report chronic strength deficits in the affected leg (Lyle).

Source: Medical Disability Advisor



Rehabilitation

The goals of rehabilitation following a quadriceps tendon rupture are to decrease pain and to return the individual to full function with a painless, mobile knee. The duration of treatment is related to the functional mobility, healing response, and any complications.

The focus of rehabilitation is on restoring full range of motion, strength, proprioception, and endurance while maintaining independence in all activities of daily living. While the resumption of pre-injury status is the goal, the type of rupture (partial, complete) will affect the speed of rehabilitation. Protocols for rehabilitation must be guided by the treating physician and must consider the type of rupture and rupture management (operative, nonoperative).

In order to decrease pain, local cold application may be beneficial. To prevent complications of inactivity and bed rest, individuals should be encouraged to continue functional activities that do not compromise the status of the healing tendon.

The individual will need to wear a knee immobilizer brace for several weeks following rupture to support the knee in full extension while allowing tendons to heal. Physical therapists should instruct the individual in the use of assistive devices to promote independent ambulation. The individual should progress from walker to crutches to cane according to weight bearing status and ability. Therapists will instruct the individual in range of motion exercises of the adjacent joints unless contraindicated. After the knee immobilizer is removed, range of motion, strengthening, and proprioception exercises should be started at the knee joint according to physician recommendation. Exercise intensity and difficulty should be progressed until full function is evident. The treating physician will dictate the protocol for rehabilitation.

Tendons may heal within 8 to 12 weeks; however, full restoration of tendon strength and ability to sustain a heavy load may take up to 1 year. Once healing has occurred, the individual may resume full activities of daily living. It is important to instruct the individual not to overload the tendon until it has regained its full strength. The resumption of heavy work and sports should occur under the guidance of the treating physician.

Source: Medical Disability Advisor



Complications

Persistent weakness and atrophy of the quadriceps muscles and loss of range of motion in the knee are common following quadriceps tendon rupture. If there is prolonged stiffness following immobilization, manipulation under anesthesia may become necessary. Re-rupture of the tendon may occur if the tendon is overloaded too soon. Patellar malalignment, subluxation, or degeneration may occur due to muscular imbalance following healing. Complications related to surgery may include infection or poor wound healing. A delay in necessary surgical repair may compromise return of leg function.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

Depending on work duties, the individual may need to be temporarily or permanently reassigned. The individual with quadriceps tendon rupture may be unable to stand and walk, operate equipment, or perform other tasks that require squatting, kneeling, or climbing stairs. Increased rest periods may be needed to elevate or ice the leg.

Use of a leg immobilizer brace and crutches, cane, or walker will be necessary for a period of weeks. Company policy on medication usage should be reviewed to determine if prescribed medication use is compatible with job safety and function.

If driving is a job requirement, the individual may not be able to drive for 8-10 weeks after surgery.

Source: Medical Disability Advisor



Failure to Recover

If an individual fails to recover within the expected maximum duration period, the reader may wish to consider the following questions to better understand the specifics of an individual's medical case.

Regarding diagnosis:

  • Did individual sustain a traumatic injury to the leg?
  • Did individual report a tearing or popping sensation followed by sudden, sharp pain in the anterior thigh?
  • Does individual have difficulty standing and walking?
  • Has diagnosis been confirmed with x-ray, MRI, ultrasound, or arthroscopy?
  • Is knee swollen and bruised?
  • When did rupture occur? Was treatment sought immediately?

Regarding treatment:

  • Was rupture partial or complete?
  • Was surgical treatment required?
  • Has individual participated in physical therapy?
  • Has individual followed recommendations for weight bearing restrictions and use of leg immobilizer brace?
  • Has individual been compliant with medication and home treatment regimen?

Regarding prognosis:

  • Has leg strength and ability to walk been completely restored?
  • Has full knee range of motion been completely restored?
  • Would further physical therapy be helpful for this individual?
  • Does individual have any comorbid conditions that may delay healing?
  • How will use of the leg be affected by complications?

Source: Medical Disability Advisor



References

Cited

Gerbino, Peter, and Jason Nielson. "Knee Injuries." Essentials of Physical Medicine and Rehabilitation. Eds. Walter R. Frontera, Julie K. Silver, and Thomas Rizzo. 2nd ed. Philadelphia: Saunders, Elsevier, 2008.

Hyman, Jon. "Patellofemoral Tendinopathy." DeLee and Drez's Orthopaedic Sports Medicine. Eds. Jesse DeLee and David Drez. 2nd ed. 2 vols. Philadelphia: W.B. Saunders, 2003.

Lyle, James, and Lynn A. Crosby. "Quadriceps Tendon Rupture." eMedicine. Eds. Pillip J. Marone, et al. 7 Mar. 2008. Medscape. 6 Mar. 2009 <http://emedicine.medscape.com/article/1249621-overview>.

Source: Medical Disability Advisor






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