BRINGING SCIENCE TO TREATMENT

Meniscal root tears part II – the road to recovery

In part one of this two-part article, Chris Mallac explored the anatomy, diagnosis and imaging options for meniscal root tears. In this article, he discusses the management options for meniscal root tear injuries.

2018; Third baseman Jefry Marte (19) throws the ball to first base from his knees. Credit: Kim Klement-USA TODAY Sports

The management of meniscal root tears can be either nonoperative, partial meniscectomy or meniscal root repair:

Non-surgical treatment

Non-surgical treatment is usually reserved for the elderly type patient and for those with extensive arthritis, or those who are poor surgical candidates. In the athletic population, non-surgical treatment is not the recommended option as the native anatomy of the knee joint and thus function is not restored, leading to joint space narrowing and arthritic changes. Therefore, this option will not be discussed in this article.

Surgical treatment

*Meniscectomy

In the athletic population, partial or complete meniscectomy is not recommended as it only provides short term relief of symptoms and the long-term outcomes are not known. To summarise a few studies that have compared meniscectomy versus repair:

  • In a recent study, it was reported that 35% of patients who received meniscectomy required revision surgery using total knee arthroplasty, however in those who received meniscal repair none required revision surgery(1). Further, they found that meniscectomy was associated with a 5-year survival rate of only 75% among patients; whereas, meniscal repair was associated with a 100% 5-year survival rate.
  • Lee et al concluded that for the treatment of medial meniscus root tears, the arthroscopic pull-out repair provides better clinical and radiographic outcomes in the long-term than partial meniscectomy(2). It also has a higher potential to completely heal the meniscus that facilitates the ability of the meniscus to convert axial load into hoop stress.

Meniscectomy is reserved for the following types of patients:

  • Patients with chronic root tears and symptomatic grade-3 or 4 chondral lesions (ie pre-existing arthritis) who fail nonoperative treatment.
  • Patients with partial root tears, and a substantial portion of the footprint still intact.

For the athlete, repair of the root tear remains the preferred option(3,4).

 *Meniscal root repair

Due to the dissatisfaction with partial meniscectomy in the treatment of meniscal root tears in the athlete, there has been a growing interest in meniscal repair(5,6), and this has led to a number of different types of repairs with different fixation methods. In the athletic population, repair of meniscal root injuries is indicated for both symptomatic relief and prevention of degenerative joint disease. The main indications for meniscal repair include(7,8):

  1.  Acute, traumatic root tears in patients who have yet to develop osteoarthritis, with the goal of preventing arthritic changes in the future;
  2. Chronic symptomatic root tears in young or middle-aged athletes without significant pre-existing arthritis.

For lateral sided injuries, posterior root tears are often associated with ACL injuries, and the root should be repaired during concomitant ACL reconstruction. On the medial side, there are usually two injury patterns, acute and chronic. An acute medial root tear is often associated with a multiligamentous knee injury, specifically a complete tear of the MCL where the meniscocapsular ligaments are maintained but the meniscus is avulsed at the root(9). In these situations, there is a clear indication for a root repair to prevent the development of arthritis.

In contrast, chronic tears are often due to subtle, nonspecific injuries, and which have been reported to go on to rapid ipsilateral compartment cartilage degeneration if not properly diagnosed(7,9). A chronic posterior medial root tear would be more likely in athletes who spend a large amount of time in full knee flexion, and are loading and pivoting in this position (see figure 1). Examples of this would include cricket wicketkeepers, hockey goalkeepers, Brazilian JuJitSu, judo, surfing and wrestling.

Figure 1: Mechanism for a chronic posterior horn root tear (sustained and loaded knee flexion)


Repairs to the meniscal roots (see figure 2) are reasonably successful due to some unique anatomical features of the meniscus. The posterior root has better blood supply (via the perimeniscal capillary plexus and small vessels through the bony attachment site) compared to the middle horn of the meniscus(10,11). Furthermore, due to the distinctive anatomical feature of the radial direction of collagen from the root, enough tensile strength can be maintained during suture repair, which allows for successful repair of the posterior root of the medial meniscus(12). The effort to restore hoop tension via suture has been shown to be important for delaying the progression of arthritis.

Figure 2: Example of meniscal root repair following a radial tear using a suture tunnel

 


Post-operative Management

There exists no definitive agreed upon post-operative management of meniscal root repairs, and the evidence for a structured rehabilitation protocol is scant in the literature. However, there are some important considerations that needs to be taken into account with rehabilitation of meniscal root repairs(13). In particular, due to the unique nature of the fixation for meniscal root repairs, care must be taken with early loading of the meniscus during the healing stages. Therefore, it is recommended that the rehabilitation process is broken down into five distinct stages(14,15).

Stage one: protection and healing (weeks 1-6)

Aims

  • Allow repair of the repaired meniscus root.
  • Avoid cyclic loading that may loosen the root repair.
  • Resolve joint effusion.
  • Maintain some quadriceps activation.
  • Regain passive range of motion into knee extension and flexion.
  • Non-weight bearing in the initial six weeks.

Notes

  • Reduced cyclical loading will help to minimise disruption of the integration of the repair to the bone, reduce risk of meniscal extrusion, and avoid excessive pressure on the articular cartilage that occurs with meniscal extrusion.
  • Weight bearing is also limited to reduce potential inflammatory stimuli and aid in resolving joint effusion.
  • Athletes are required to wear a straight-leg brace for six weeks to provide protection in the event of a fall, and to prevent them from holding their knee in flexion during gait (which would activate the hamstrings and popliteus, and potentially impart stress to the meniscal root).

Range of motion

  • Passive range of motion by therapist up to 90 degrees flexion for the first two weeks and then progressed as tolerated from weeks three to six.
  • It is important to avoid any active knee flexion ranging in the first six weeks to avoid the hamstring and popliteus pulling on the meniscus (due to their attachment onto the meniscus).
  • Passive patellofemoral mobilisations allowed and passive soft tissue massage to quadriceps, hamstrings, iliotibial band, gastrocnemius and hip flexors encouraged.

Muscle activation

  • No hamstring activation allowed in the first six weeks.
  • Quadriceps activation in terminal extension allowed and need to be kept as open kinetic chain only. This can be done in sitting with the knee in terminal extension and the knee may be flexed passively under gravity.
  • If electrical muscle stimulation (EMS) is available, then the use of this on the quadriceps in atrophy mode would be useful at this stage.
  • Gluteal activation in side lie allowed with brace in situ.

Cardiovascular

  • Non-weight bearing cardiovascular only.
  • Activities such as seated boxing, arm grinder and battling ropes in sitting are allowed at this stage as long as there is no hamstring activation.
  • Swimming with a pool buoy between thighs to avoid kicking.

Exit criteria: stage one

·       Full range of motion (passive)

·       Minimal or no effusion

·       Voluntary quadriceps activation

·       Surgeons approval to progress

Stage two: early progressive loading (weeks 7-9)

Aims

  • To progressively reload the meniscus into full weight bearing.
  • Normalise gait on flat ground.
  • No effusion.
  • Build standing and walking tolerance.
  • Commence isometric hamstring activation.

Weight bearing

  • Start at week seven with 25% bodyweight.
  • Week eight progress to 50% bodyweight.
  • Week nine progress to 75% bodyweight.
  • By week ten the athlete should be full weight bearing.

Muscle activation

  • Commence isometric hamstring activation initially in terminal extension and progress into positions of knee flexion.
  • No isotonic hamstrings allowed until week twelve.
  • LIGHT single leg press is allowed at this stage from 0-30 degrees flexion (lateral posterior horn repairs) and 0-60 degrees flexion (medial posterior horn repairs) and allowing for the relevant weight bearing status(15).
  • Seated calf raise can commence in this stage and double leg squats and standing calf raise allowed when the athlete is 100% weight bearing.

Cardiovascular

  • Stationary bike with little resistance may commence at this stage.

Exit criteria: stage two


·       Full weight bearing

·       Minimal or no effusion

·       Normal gait on flat ground

·       Tolerate up to 25 minutes of standing and walking activity

Stage three: endurance and strength (weeks 10-16)

Aims

  • Develop quadriceps endurance and strength in limited range of motion (less than 70 degrees flexion with closed kinetic chain).
  • No effusion.
  • Develop single leg control.
  • Single leg stance (eyes closed) for more than 30 seconds.
  • Commence isotonic hamstring activation.

Weight bearing

  • Full weight bearing, with walking and closed kinetic chain exercises.

Muscle activation

  • Commence isotonic hamstring activation focusing on hip dominant movements with minimal knee flexion until week 16. Examples of exercises would include double leg Romanian deadlift progressing to single leg, back extension double and single leg, straight leg and 45-degree knee bent bridging.
  • Closed kinetic chain (CKC) exercises are progressed over the six weeks with increasing weight and decreasing repetitions. Range of motion is kept to a maximum of 70 degrees at this stage to continue to protect the posterior root from high compressive and shear loads. A typical endurance to strength progression would be:
  • Weeks 10-11 3 x 12
  • Weeks 12-13 4 x 8
  • Weeks 14-15 5 x 6
  • CKC exercises include double-leg leg press, single-leg leg press, wall squat →double leg squat→single leg squat, Bulgarian squat, TrX pistol squats.
  • Progress seated/standing calf raise strength.

Proprioception

In this stage, proprioception exercises are emphasised, and these may include (as examples):

  • Single leg stance retraining – flat surface → Duradisc →Wobble board →BOSU ball.
  • Sand walking and variations of walking.
  • Light jogging on trampoline.

Cardiovascular

  • Stationary bike with little resistance continues. Avoid heavy resistance until week 16.
  • Treadmill walking.
  • Swimming with kicking (but no fins).
  • Standing boxing.
  • No rowing ergometer (this requires more than 90 degrees knee flexion).

Exit criteria: stage three

• Maintain no effusion

• Good control of single leg squat from a 40cm box (limit flexion to 70 degrees).

• More than 85% quadriceps strength compared to unaffected side

Stage four: return to function (weeks 17-26)

Aims

  • Progress quadriceps strength up to 90 degrees flexion in closed kinetic chain.
  • Commence running and easy change of direction.
  • Progress proprioception and balance to more dynamic plyometric activities.

Muscle activation

  • Progress hip-dominant hamstring isotonics and commence knee dominant hamstring exercises (limit flexion range to 90 degrees). Examples of knee dominant hamstring exercises: Nordic hamstring exercise, single-leg leg curl (up to 90 degrees), single leg Swiss-ball curl, bridges with knee bent to 90 degrees.
  • Closed kinetic chain (CKC) exercises for the quadriceps are progressed in loading and range of motion (up to 90 degrees flexion).
  • Unlimited calf-raise strength and core/hip muscle activation work.

Proprioception

  • In this stage, dynamic proprioception exercises are emphasised, and these may include as examples: single leg hop and land on BOSU ball, practice cross over hop test, run/stops on trampoline.

Cardiovascular

As previous stage, but with a return to running (weeks 20-26). However, the following points to need to be kept in mind:

  • Develop speed and running mechanics via the use of running drills.
  • Develop acceleration capability.
  • Develop speed capacity
  • Develop the ability to decelerate and stop.
  • Introduce change of direction retraining in parallel with increase in running speed and volume over a six-week period.

Exit criteria: stage four


·       Maintain no effusion.

·       Good control of 50⁰change of direction to either side.

·       Return to >85% of pre-injury running speed

·       More than 90% quadriceps strength compared to unaffected side.

·       More than 80% hamstring strength compared to unaffected side.

Stage five: return to performance (weeks 26 onwards)

Aims

  • To progress the athlete back into their chosen sport.
  • Range of motion under heavy load is restricted to 90 degrees of knee flexion for first six months.

Muscle activation

  • No restrictions on loading quadriceps and hamstrings.
  • The range of motion in heavy loaded closed kinetic chain exercises is limited to a maximum of 90 degrees up to six months post-operatively, and progressed to full comfortable range under load over the next six months. The expectation would be that the athlete is back into full competition; however they are avoiding heavy squats past 90 degrees. This can be progressively increased to full range by one year post-operative.
  • Plyometric drills with short knee flexion angles can be encouraged in this stage.

Skills training

  • Introduced into skills training and contact training over a defined period to develop skill acquisition and confidence.
  • It would be expected that the athlete is back to full sport participation at approximately none months post-operative.

Exit criteria: stage five


·       Greater than 90% hop distance and cross-over hop test compared with other side

·       Return to full sprint speed.

·       Return to full acceleration and deceleration.

·       Full confidence and competence over a prolonged period of competitive training.

·       More than 90% strength in quadriceps and hamstrings.

References

  1. Arthroscopy 2015;31:1941-50.
  2. Arthroscopy 2009;25:951-8
  3. J Bone Joint Surg Am. 2008;90(9):1922-1931
  4. Am J Sports Med. 2012;40(10):2342-2347.
  5. 2011;27:346-54.
  6. 2010;26:1326-32.
  7. 2009;25(9):1025-1032.
  8. Br Med Bull. 2013;106:91-115.
  9. 1991;7(3):297-300.
  10. Am J Sports Med. 1982;10:90-5.
  11. 1985;1(1):58-62
  12. Anat Embryol (Berl). 1998;197:31724
  13. JOSPT; 2016. 46(2). 104-113.
  14. Joyce D and Lewindon D (2016) The athletic knee. In Sports Injury Prevention and Rehabilitation. Integrating medicine and science for performance solutions. Routledge. London.
  15. Arch Orthop Trauma Surg. 2005;125:254-260.

 

 

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