Chondromalacia Patella

Chondromalacia Patella (CMP), also known as Patellofemoral Syndrome, is a condition characterized by chronic patellofemoral pain due to degenerative changes in the articular cartilage of patella.

Chondromalacia Patella

Chondromalacia Patella (CMP), also known as Patellofemoral Syndrome, is a condition characterized by chronic patellofemoral pain due to degenerative changes in the articular cartilage of patella.

Classification

The macro- and microscopic changes in the articular cartilage of the patella have been classified as follows:

• Grade i: Localized softening of the articular cartilage. Slight discoloration but no ulceration on the surface. A blunt instrument pressed on this area may sink into the cartilage.
• Grade ii: An area of fibrillation and fissuring with an irregular surface.
• Grade iii: Fibrillation and fissuring extends down to sub-chondral bone. Arthroscopic appearance is called “Crab Meat Appearance”.
• Grade iv: Articular Cartilage is completely eroded and subchondral bone is exposed.

Clinical Symptoms and Signs

Patients affected are either adolescents and young individuals involved in vigorous sports activities or elderly individuals with degenerative changes.

• Patients usually present with discomfort and pain in the anterior part of knee joint which is classically worsened on sitting with knee flexed for a prolonged period (“movie sign” or “theater sign”).
• Crepitation may be elicited in the patella femoral joint.
• Patient may complain of catching or giving way of the knee joint, especially while descending stairs.
• Debris from articular cartilage shed into the joint may cause chemical irritation leading to synovitis with effusion and pain.

Investigations

Radiographs

Plain radiographs do not reveal pathologic changes in the patellae in cmp, but are helpful in diagnosing bony malalignments, such as patella instability and genu valgum, which are important etiological factors. In addition to anteroposterior and lateral radiographs, patella skyline views and standing scannograms of the lower limbs are important studies for the diagnosis of these bony malalignments.

Magnetic Resonance Imaging

Magnetic Resonance Imaging (MRI) of the knee joint may have chondral changes in the patella

Diagnostic Arthroscopy

Arthroscopy remains the gold standard for diagnosis of cmp, especially in the initial stages of the disease.

Treatment

The treatment of cmp is directed to the cause.

Initial treatment always consists of conservative measures

• Including anti-inflammatory medications
• Icing
• Physiothearpy
• Activity modifications including strict avoidance of ground level activities, squatting and sitting cross legged are also an integral part of conservative treatment regime.
• Customised Insoles

Physiotherapy

Chondromalacia patella patients usually have tight hamstrings, tight iliotibial bands, tight lateral patellar retinaculum, increased foot pronation, tight gluteal muscles are associated or causative factors for chondromalacia patella.

While addressing a patient of chondromalacia patella it is important to address both strengthening and stretching as a part of the physiotherapy regimen./p>

Strengthing mainly focuses on the vmos and quadriceps, hip abductors.

Stretching includes the hamstrings, vastus lateralis and iliotibial band.

Taping is beneficial for correcting the patellar malalignment and better tracking of the patella.

Foot orthoses or customised insoles for correcting the malalignments arising from foot overpronation can help in long term correction of chondromalacia patella.

Closed kinetic chain exercises (semi-squat) are more effective than open kinetic chain exercises [active straight leg raise (aslr)] in relieving the pain associated with patella chondromalacia.

Surgical treatment of cmp can be divided into two categories:

• Surgeries aimed at correction of patella maltracking
• Surgeries aimed at reversal of articular cartilage changes of cmp

Indications:

• Failure of dedicated trial of conservative treatment
• After the cause of knee pain has been ascertained after thorough evaluation. Arthroscopy is a valuable tool for diagnosis and chondromalacic areas can be directly visualized and probed

Aim

Malalignment of extensor mechanism is the most common cause of cmp and most of the surgeries for cmp are aimed at correcting this malalignment.

The surgical options available in this category are as follows:

• Lateral Retinacular Release: By open or arthroscopic technique, if incongruity and lateral tilting of the patella is seen on axial radiographs
• Osteotomies for bony malalignment, such as femur anteversion, tibial external torsion and genu valgum.

Surgical procedures aimed at reversing the chondral changes in the patella are as follows:

• Arthroscopic Patellar Shaving: Excision of debris which may potentially lead to synovitis if shed into the joint
• Local excision of the defect with microfracture: Opens vascular channels between the articular surface and subchondral bone which brings about resurfacing of the chondral defects with fibrocartilage
• Facetectomy
• Decompression of articular surface of patella by anterior elevation of tibial tuberosity (maquet procedure)
• Patellectomy for severe cases
• Patellofemoral Arthroplasty

Biologic approach to treat chondromalacia patella

Of late, biologic treatment has shown promise in regeneration of damaged cartilage. Autologous chondrocyte implantation (aci) has been shown to improve knee scores in cmp. The results were further improved if concomitant correction of extensor mechanism malalignment was performed.

Autologous chondrocyte implantation (aci) is a 2 stage procedure in which, in the first stage cartilage biopsy is taken from the knee arthroscopically. This cartilage is sent to the laboratory where the cartilage is grown and mixed with fibrin glue and made ready for implantation in about 3-4 weeks. In the second stage, this mixture is implanted in the cartilage defect which is an open procedure.

PRP

Platelet Rich Plasma is a newer methodology to treat chondromalacia. A sample of blood is taken and centifuged at very high speeds which seperates the plasma from the blood cells. This plasma is rich in platelets, growth factors and anti inflammatory factors. Injecting this platelet rich plasma at the site of defect is thought to help in regeneration of cartilage and also helps in pain relief because of the anti inflammatory factors. This treatment is still in th experimental stage but is used widely for a variety of other orthopaedic problems too.