OrthoNeuro Blog

11 Sep

Why is MRI Useful in Determining an ACL Tear? How is a Tear Treated?

by B. Rodney Comisar, MD

The MRI is diagnostic in determining whether the ACL is torn.  Partial tears are rare and occur most commonly in younger adolescent athletes – the ACL is comprised of two bundles and thus an injury to just one of the bundles is possible but occurs infrequently.  In adolescents and adults, typically the ACL is either functional or incompetent.  The MRI is particularly useful in diagnosing associated injuries to the menisci, the articular cartilage on the surfaces of the joint, and other ligaments of the knee. Bone bruises often occur in conjunction with ACL tears as result of the shifting phenomenon which happens at the time of injury.  Bone bruises contribute to the acute pain and inflammation but resolve over time.  The long-term ramifications of the bone bruises and impaction injury to the overlying articular cartilage are not well-defined, but there are concerns about an association with the development of arthritis in the knee, specifically in the lateral compartment.  The approach to treatment of ACL injuries is based on restoring stability to the knee and minimizing further injury to the menisci and joint surfaces. 

ACL InjuryIn rare instances an individual may attempt a trial of conservative treatment with rehabilitation and bracing in an attempt to return to play, but this is not always successful.  This treatment course may be undertaken in a senior athlete attempting to complete the final season of competitive sports, after a detailed discussion and understanding of the inherent risks of reinjury.  This option is not recommended in sports such as soccer, basketball, volleyball and football but can be most successful in lower demand sports involving less cutting or when the individual plays a position such as offensive line in football, rather than a skill position.  Again, the goal is to avoid additional injury to the knee, as the ACL is already torn and does not heal.  In some respect it is easier to treat the ACL tear surgically rather than concomitant complex injuries to the menisci and articular cartilage which can start the progression of arthritis.

Surgical timing varies, depending on the patient’s early recovery and any associated injuries.  It is recommended that surgical treatment be delayed until the knee range of motion returns to normal and knee swelling subsides, typically 2-4 weeks post-injury. Research studies have demonstrated early surgery before the knee “cools off” can lead to difficulty recovering full range of motion postoperatively.

ACL surgery involves reconstruction of the ligament, either with the patient’s own tissue (autograft) or a donor/cadaver tissue (allograft).  Autograft tissues used include a portion of the patellar or quadriceps tendons or 2 hamstring tendons.  Allograft tissue options include patellar, Achilles, hamstring, and anterior & posterior tibialis tendons.  The graft choice is individualized based on the patient’s activity level, sport, age, and any preexisting knee conditions.  The results of ACL reconstruction are far superior using autograft tissue in young competitive athletes.  Patellar tendon autograft is the preferred choice of the majority of NFL and other professional team physicians.  The surgical procedure begins with an examination under anesthesia to confirm the suspected instability.  An arthroscopy is performed to prepare the knee for the ACL graft and to treat injuries if any to the menisci and articular cartilage. The postoperative course is lengthy, involving hours of physical therapy and diligence with home exercises.  Some surgeons use a combination of crutches for protected weight-bearing and/or bracing during the early postoperative period.  Continuous passive motion machines (CPMs) also may be utilized to aid in range of motion recovery.  Associated treatment of meniscal (repairs) and articular cartilage injury (microfracture) may extend the period of protective bracing and crutch use after surgery.  Running may ensue 10-12 weeks postoperatively, with a gradual return to cutting, pivoting, sport-specific activities by 6-8 months.

Dr. Rodney Comisar - Orthopedic Surgeon- ACL Repair

Dr. B. Rodney Comisar is a board certified, fellowship-trained orthopedic surgeon who specializes in sports medicine related injuries.  He has a sub-specialty certification in Sports Medicine.  Dr. Comisar offers a full spectrum of sports medicine surgery, including arthroscopy and minimally invasive procedures.  Dr. Comisar’s special areas of interest include:  multi-ligamentous knee injuries/dislocations; ACL injuries/reconstruction; rotator cuff injuries/tears; patellar instability/dislocation; proximal hamstring ruptures; shoulder instability; and shoulder arthritis including total shoulder replacement and reverse total shoulder replacement.

 

Sports Injury? Schedule an appointment with Dr. Comisar today!  Call his direct line at 614-839-2108 or click the button below to request an appointment online.

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