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.

Repair (Reconstruction), Anterior Cruciate Ligament


Related Terms

  • ACL Reattachment
  • ACL Reconstruction

Specialists

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

Comorbid Conditions

Factors Influencing Duration

Work requirements, complications, and inability or unwillingness to participate in a rehabilitation program will affect length of disability. Associated injuries and treatment will also affect the duration of disability. Activities stressful to the knee must be avoided. If job duties can be performed while sitting, duration may be shorter.

Medical Codes

ICD-9-CM:
81.45 - Repair of Anterior Cruciate Ligament, Other

Overview

© Reed Group
Anterior cruciate ligament (ACL) repair or reconstruction is a surgical procedure used to restore the integrity and function of the ACL after it has been ruptured or torn from (avulsed from) the skeletal structure of the knee. Unlike other body tissues, the ACL does not heal or repair itself after injury. The ligament is intra-articular and thus the joint fluid that is normally present in the joint and that nourishes the articular cartilage prevents blood clot formation (preventing the first stage in ligament healing). Although the term "ACL repair" is often used interchangeably, the actual surgery is a reconstruction using graft tissue.

The ACL is a powerful ligament extending from the top-front surface of the shinbone (tibia) to the bottom-rear surface of the thighbone (femur). The ligament prevents "anterior" instability in the knee joint (tibia moving anteriorly from underneath the femur). The ACL also provides rotational stability to the knee. This stability is particularly important to athletes or individuals whose activities include running, jumping, or kicking.

ACL injury can occur when an individual comes to a quick stop (sudden deceleration); suddenly changes direction while running, pivoting, or landing from a jump; or overextends the knee joint. The ACL is the most commonly injured major knee ligament. Injury prevention includes hamstring-strengthening exercises and the use of proper techniques when playing sports or exercising.

There is little functional demand on the anterior cruciate ligament during normal level ground walking, with sports. Uneven ground, heavy carrying, and landing from jumps being the primary stressors.

Many cases of ACL injury occur in conjunction with other knee injuries. Approximately 50% of individuals with ACL injuries also have meniscal tears (Gammons).

Source: Medical Disability Advisor



Reason for Procedure

The purpose of ACL reconstruction is to restore the strength and function of the ACL, thus stabilizing the knee joint. This helps to prevent additional serious damage to the knee and slow the onset of degenerative arthritis.

Source: Medical Disability Advisor



How Procedure is Performed

ACL reconstruction is usually scheduled at least 3 weeks after the injury to avoid the complication of arthrofibrosis (the formation of dense fibrous scar tissue within the joint). Surgery may be performed as an open procedure or arthroscopically. Most individuals are given general anesthesia, although ACL repair can be performed under spinal or regional anesthesia.

The ligament is reconstructed by taking a piece of tendon from a different part of the body (autograft) or from a cadaver donor (allograft) and connecting it to the tibia (shinbone) and femur (thighbone). Although there are different methods for ACL reconstruction, they all involve the same basic procedure. An incision is made in the individual's leg, and small tunnels are drilled into the femur and tibia bones. Then the new or harvested ACL is brought through the tunnels and secured with either metal fixation or a bioabsorbable system. Proper tension is crucial, since a lax graft may not restore stability to the knee, whereas a graft that is too tight may fail (rupture) or limit knee range of motion.

Patellar tendon autograft uses a portion of the individual's own patellar tendon, which connects the kneecap (patella) to the shinbone (tibia). The middle third of the tendon and a small portion of the bone on either end are harvested and used as the new ACL. This method allows a high rate of return to pre-injury levels of activity. However, 10% to 40% of individuals who undergo this procedure have postoperative anterior knee pain (Gammons).

Another autograft method of ACL reconstruction uses the individual's hamstring tendons (semitendinosus-gracilis), which connect muscles in the back of the thigh to the lower leg. A small portion of these two tendons is removed through an incision in the individual's leg and looped to form a strong new ACL. This method is associated with faster recovery from surgery and less anterior knee pain. Some critics believe this method to be more susceptible to graft stretching (elongation), although fixing the new ligament to cortical bone (rather than to cancellous bone) improves stability. Using 2 tendons in an "anterior and posterior-double bundle technique" may produce better rotational stability.

A third method of ACL reconstruction, an allograft, uses tendon from an organ and tissue donor (cadaver). This method does not disrupt other structures within the individual's knee or leg to obtain grafts. Allografts are sterilized, and disease transmission is a low risk. Synthetic grafts are no longer used due to high rates of complications (Gammons).

Source: Medical Disability Advisor



Prognosis

In general, conservative treatment of an injured ACL has a variable long-term prognosis. Individuals who are sedentary, or who engage only in light manual work and sports that do not require abrupt stops or changes of direction, may benefit from nonoperative treatment of minor instability. The goal of conservative treatment is to return range of motion and strength comparable to those of the uninjured knee. Nonoperative treatment may result in a mildly increased risk for recurrent injury, meniscal damage, and onset and progression of osteoarthritis.

Individuals with major instability or those who do heavy labor or engage in high-demand recreational activities are candidates for ACL reconstruction. The procedure relieves symptoms, improves function, and reduces the risk of osteoarthritis. ACL reconstruction restores activity level and stability in 75% to 95% of cases. The ACL repair failure rate is approximately 8% and is largely attributable to recurrent instability, graft failure, or arthrofibrosis (Gammons).

Source: Medical Disability Advisor



Rehabilitation

Rehabilitation, requiring months of intense exercise, is recommended for successful recovery from a surgical repair of the anterior cruciate ligament. Rehabilitation following ACL repair follows a structured process beginning immediately after the surgical repair and ending with the individual returning to work and other activities. The entire process can take up to 6 months. Accelerated programs are now preferred, as earlier active knee extension does not appear to cause ligamentous laxity later (Amy).

Initially the physical therapist uses modalities, such as cold packs, to decrease postoperative pain and swelling. The physician may request very gradual weight-bearing immediately after the ACL repair. A rehabilitation brace, also called a postoperative brace, is typically used immediately after surgical repair.

Once pain and swelling are controlled, knee range of motion is started in rehabilitation and performed as tolerated, and as guided by the surgeon. Ankle range of motion of the involved lower extremity should be encouraged intermittently throughout the day to promote blood circulation. By the end of this phase, crutch walking should be easily tolerated.

At the end of immobilization, when swelling is controlled and pain is minimal, active assisted flexion and passive extension may be performed along with quadriceps strengthening exercises (Amy). Goals of rehabilitation are to achieve full and pain-free motion of the knee joint along with strengthening of, in particular, the quadriceps and hamstring muscle groups, and all muscles in the involved leg. Aquatic exercises may be useful (Amy).

When there is no swelling, minimal to no pain, and almost full range of motion, the individual is encouraged to walk, with weight bearing restrictions as indicated by the surgeon, and may be allowed to return to light work. More intense exercising, with increased resistance, is called for during this phase. Cycling and proprioceptive exercises may be attempted at this time. Resisted exercise as guided by the therapist includes closed kinetic chain exercises and progresses to sports-specific training with the use of a brace (Amy). The individual is instructed in a home exercise program during each phase of the rehabilitation process.

The individual's reinstatement to work as exercise is now directed toward work requirements. The physician may prescribe a brace to be worn by the individual at the onset of resuming functional activities, and when the individual returns to work, training, or competition. However, evidence does not support using braces either in the short term (immediately after surgery) or the long-term to improve ACL reconstruction outcomes (Kruse).

Generally speaking, rehabilitation of the anterior cruciate ligament will vary depending on the type of surgery that was performed, the location from which the graft was harvested, and whether any associated supporting ligament and cartilage were also injured and / or repaired.

FREQUENCY OF REHABILITATION VISITS
Surgical
SpecialistRepair (Reconstruction), Anterior Cruciate Ligament
Physical TherapistUp to 24 visits within 26 weeks
The table above represents a range of the usual acceptable number of visits for uncomplicated cases. It provides a framework based on the duration of tissue healing time and standard clinical practice.

Source: Medical Disability Advisor



Complications

Associated conditions include injuries to other structures in the knee, such as tears to the crescent-shaped discs of fibrocartilage attached to the superior articular surface of the tibia (menisci), fractures of the patella, and osteoarthritis.

Many ACL reconstructions are successful. Common complications include a decrease in knee range of motion (which can be minimized by early rehabilitation) and anterior knee pain. Less common complications include fractures of the patella and patellar tendon rupture (Gammons). The quadriceps tendon can also rupture, depending on the site where the graft was harvested.

About 8% of ACL reconstructions fail (Gammons). These failures are usually due to recurrent instability, ongoing pain, or arthrofibrosis (scar tissue build-up inside the knee joint). Other surgical complications include infection, bleeding, stiffness of the joint, vein inflammation (phlebitis), and complex regional pain syndrome (CRPS). Improper placement of the graft can cause impingement and require additional surgery. Grafts rupture in approximately 2.5% of cases (Gammons). If symptoms return after surgery, hardware removal may be necessary.

Any type of surgery is associated with potential risks and complications that may include, but are not limited to injury to blood vessels and nerves around the knee (less than 1%); blood clots in the legs (deep vein thrombosis), which may break off and go to the lungs (embolism) (less than 1%); and infection (less than 1%) (Gammons). Small areas of diminished sensation in the front of the knee are common and usually do not present a problem.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

Limited weight-bearing, use of a knee brace, and rest periods for elevation of the leg would be expected at work during the early stages of recovery. Long-term use of a protective knee brace may be recommended. Individuals should refrain from activities requiring squatting, jumping, and abrupt turning or twisting. Postoperative medications may include nonsteroidal anti-inflammatory drugs (NSAIDs) and prescription painkillers (opioid analgesics). Use of analgesics and other medications can affect dexterity and alertness. Review of drug policies may be required to accommodate this use.

Source: Medical Disability Advisor



Maximum Medical Improvement

Treated with surgical reconstruction, MMI for isolated anterior cruciate ligament rupture is usually reached by 224 days after surgery. The ligament will continue to strengthen over time, but the clinical result in terms of stability, motion, and muscle strength is usually stable by 224 days.

Treated non-surgically, MMI for isolated anterior cruciate injury is usually reached within 112 days of injury. Symptoms may continue to improve for up to a year after injury.

Source: Medical Disability Advisor



References

Cited

Amy, Eduardo, et al., eds. "Chapter 55 - Anterior Cruciate Ligament Tear." Essentials of Physical Medicine and Rehabilitation. 2nd ed. Philadelphia: Saunders, Elsevier, 2008.

Belanger, M. J. "Knee Laxity Does Not Vary with Menstrual Cycle, before or after Exercise." American Journal of Sports Medicine 32 5 (2004): 1150-1157.

Gammons, Matthew, and Evan Schwartz. "Anterior Cruciate Ligament Injury." eMedicine. Eds. Francisco Talavera, et al. 4 May. 2012. Medscape. 6 Feb. 2013 <http://emedicine.medscape.com/article/89442-overview>.

Kruse, L. M. , B. Gray, and R. W. Wright. "Rehabilitation after Anterior Cruciate Ligament Reconstruction." Journal of Bone and Joint Surgery 94 (2012): 1737-1748.

General

Linko, E., et al. "Surgical Versus Conservative Interventions for Anterior Cruciate Ligament Ruptures in Adults." Cochrane Database of Systematic Reviews 2 (2005): NA.

Souryal, Tarek, and Kenneth Adams. "Anterior Cruciate Ligament Injury." eMedicine. 19 Mar. 2012. Medscape. 25 Feb. 2013 <http://emedicine.com/PMR/topic3.htm>.

Source: Medical Disability Advisor






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