Cartilage Injury in the Knee: Assessment and Treatment Options

Aaron J. Krych, MD; Daniel B. F. Saris, MD, PhD; Michael J. Stuart, MD; Brittney Hacken, MD


J Am Acad Orthop Surg. 2020;28(22):914-922. 

In This Article

Concurrent Pathology

Once a cartilage lesion is identified, multiple variables must be evaluated when determining treatment options. The patient's clinical symptoms must correlate to physical examination and imaging findings to determine if the cartilage injury is the source of the patient's pain. In addition, a thorough ligamentous examination should be completed, assessing the cruciate and collateral ligaments and the patellofemoral joint. Ligament reconstruction surgery should take place before or concurrent to any cartilage procedures to obtain a successful outcome or else the cartilage treatment may be placed under excessive stress and fail. Lower extremity standing alignment should be assessed on examination for static or dynamic varus or valgus overload of the compartment and full length standing radiographs should be analyzed in all cases. A proximal tibial or distal femoral osteotomy should be considered if a 5° or greater mechanical axis deviation is present in the affected compartment[4] (Figure 1). Meniscus pathology should be carefully evaluated on MRI and arthroscopic examination. All attempts to preserve the meniscus through repair should be taken. The meniscus roots should always be examined and repaired if necessary because increased contact forces have been noted in the absence of an intact medial meniscus posterior root.[5] Patients with irreparable meniscal pathology and total/subtotal meniscectomy should be considered for a meniscal allograft transplantation.[6] Selective treatment of bipolar lesions can be considered.

Figure 1.

Full length standing radiographs showing varus alignment (left image) and then correction to neutral alignment after medial proximal tibia opening wedge osteotomy (right image).

Finally, patients with patellofemoral instability are evaluated with physical examination, radiographs, MRI, and occasionally CT scans to identify lateral patellar tilt, patella alta, medial patellofemoral ligament incompetence, trochlear dysplasia, increased tibial tubercle-trochlear groove distance, and coronal plane or rotational malalignment. Surgical treatments are performed to address all anatomic factors that may place a patient at increased risk of recurrent dislocation or place excess stress on any cartilage procedures performed. Treatment options include but are not limited to tibial tubercle osteotomy, medial patellofemoral ligament reconstruction, and lateral retinacular lengthening at the time of patellofemoral cartilage surgery, if necessary. The purpose of these procedures is to decrease the risk of recurrent dislocations that may have led to the cartilage lesion and to decrease contact pressures on the cartilage by offloading the cartilage. For example, an anteromedialization tibial tubercle osteotomy can both decrease the risk of recurrent patellar dislocation by medializing the tubercle and offload distal pole of the patella or bipolar lesions by anteriorizing the tubercle.

Previous studies have demonstrated higher rates of cartilage restoration surgery failure when concurrent pathology is not addressed.[6] We recommend careful review of all imaging and clinical examination findings to prepare for all necessary procedures. Systematic arthroscopic or open surgical documentation of the cartilage lesions about size, confinement of the lesion, and condition of the cartilage surrounding the lesion and in the other knee compartments is of great importance to fully understand the potential background cause of the cartilage injury.