Orthopedic Teaching Cases 2023, Jan, 17 | 12:00 am

6 TO 9 Sports Medicine CASES

CASE                                6                               

During a recreational game of basketball, a 47-year-old man twists his right knee while defending an opponent. Initially, he had some swelling and walked with a limp. Over the next 2 weeks, he had continued pain with occasional symptoms of catching in his knee.

On examination, he cannot fully extend his knee and has tenderness on the medial joint line with a positive McMurray test.

What is the most appropriate next step in his evaluation?

  1. Weight-bearing radiographs

  2. MRI

  3. MR arthrogram

  4. Examination under anesthesia

  5. Diagnostic arthroscopy

 

Discussion

The correct answer is (A). In an acutely injured athlete, it is essential to rule out a fracture and to assess the degree of degenerative changes in the knee. If there is no fracture or arthritis, an MRI would be appropriate. Meniscal injuries do not require an arthrogram. An examination under anesthesia and diagnostic arthroscopy are not indicated.

The patient is found to have a displaced tear of the medial meniscus. Which

pattern of meniscal tearing is most amenable to repair?

  1. Radial

  2. Bucket-handle

  3. Oblique

  4. Horizontal cleavage

  5. Vertical

 

Discussion

The correct answer is (B). Tear types that are most appropriate for repair include vertical tears in the vascular zone of the meniscus and bucket-handle tears that are in good condition when reduced. The other patterns have a lower propensity to heal and are treated with excision.

Which of the following factors does NOT coincide with better, long-term function following a partial meniscectomy?

  1. Age older than 40 years

  2. Normal limb alignment

  3. Single tear

  4. Minimal arthritis

 

Discussion

The correct answer is (A). Better, long-term function has been reported in patients who underwent partial meniscectomy, that were less than 40 years old, had normal limb alignment, a single tear, and little arthritis at the time of arthroscopy.

Which of the following statement is true regarding the function of the meniscus?

  1. The meniscus absorbs more load in flexion than extension

  2. The meniscus is primarily composed of type 2 collagen

  3. 90% of the meniscus is water

  4. The medial meniscus provides more support than the lateral meniscus

  5. A partial meniscectomy decreases contact pressure

 

Discussion

The correct answer is (A). The meniscus absorbs up to 50% of the load across the knee in extension and 90% when the knee is flexed to 90 degrees. Type 1 collagen is the predominate type in the meniscus. Water makes up 70% of the meniscus. The

lateral meniscus provides more support than the medial. Following a partial meniscectomy, the contact pressure on the articular cartilage increases.

 

Objectives: Did you learn...?

 

 

The diagnostic algorithm of suspected meniscal injury? The anatomy and physiology of the meniscus?

 

CASE                                7                               

An otherwise healthy 30-year-old carpenter presents with left knee pain and swelling. He has had intermittent symptoms that are worse with activity. Occasionally, his knee will get stuck such that he is unable to bend or straighten it. His knee is warm and full on examination, but his ligamentous examination is symmetric with the right.

Which of the following is the likely diagnosis?

  1. Gout

  2. Lyme disease

  3. Gonococcal arthritis

  4. Synovial chondromatosis

 

Discussion

The correct answer is (D). Infectious and crystalline causes of knee swelling do not present with mechanical symptoms. Proliferation of hyaline cartilage nodules in the synovial membrane can limit motion.

An MRI is obtained which demonstrates numerous cartilage nodules throughout the knee. What is the next best step in treatment?

  1. Physical therapy

  2. Immobilization

  3. Corticosteroid injection

  4. Radiation treatment

  5. Synovectomy

 

Discussion

The correct answer is (E). Arthroscopic and/or open synovectomy can be effective at removing the cartilage nodules to address the mechanical symptoms and limiting

recurrence. However, incomplete resection increases the chance of recurrence. Physical therapy, immobilization, corticosteroid injections, and radiation treatment have not been shown to address the mechanical symptoms or to facilitate recovery.

 

Objectives: Did you learn...?

 

 

The signs of synovial chondromatosis? The treatment of synovial chondromatosis?

 

CASE                                8                               

A 35-year-old triathlete has mechanical symptoms in her left knee and is diagnosed with a medial meniscal tear via MRI. At the time of her arthroscopic partial meniscectomy, a full-thickness cartilage defect (outerbridge IV) is found on the medial femoral condyle that measures 2 cm × 1.5 cm.

What is the best treatment for this lesion?

  1. Nonoperative care

  2. Microfracture

  3. autologous chondrocyte implantation

  4. Osteochondral transplantation

 

Discussion

The correct answer is (B). A full-thickness defect is found in 4% of knee arthroscopies. Microfracture as a reparative technique has been shown to offer better results with lower morbidity in comparison to other restorative techniques currently available.

Which of the following are NOT considered a reparative marrow stimulation technique?

  1. Microfracture

  2. Drilling

  3. Mosaicplasty

  4. Abrasion chondroplasty

 

Discussion

The correct answer is (C). The use of osteochondral plugs is a restorative method like autogenous chondrocyte implantation. Microfracture, drilling, and abrasion

chondroplasty are reparative techniques that promote a fibrocartilage repair of the exposed bone by stimulating bleeding in the area of concern.

 

Objectives: Did you learn...?

 

The treatment of full-thickness chondral defects?

 

The different treatments for reparative marrow stimulation?

 

CASE                                9                               

A running back is struck on the outside of his right knee as he crosses the goal line. His cleats hold onto the turf and his knee hyperextends before giving way. The medical staff transports him to the locker room for a prompt examination. With his leg straight on the examination table, he has increased laxity to both a varus and valgus stress. With the knee bent to 30 degrees, the tibia translates more than one centimeter anterior to the femur and one centimeter posterior to the femur. His initial vascular examination on the field revealed a threaded, asymmetric pulse. Upon repeat examination, his distal pulses are symmetric. Radiographs at the stadium reveal no fracture or dislocation.

Initial management of this injury should include:

  1. Immobilization

  2. Immobilization and serial examinations

  3. Immediate surgical reconstruction

  4. Serial examinations

 

Discussion

The correct answer is (B). The athlete sustained a multiligamentous knee injury and experienced a transient dislocation of his right knee. The severity of this injury places him at increased risk for a vascular injury. Immobilization provides stability to the injured knee, while serial examinations should monitor the arterial flow and compartment pressures. Immediate reconstruction is not indicated in a complex knee injury in an athlete of any level.

Which ligaments are likely to be injured?

  1. ACL

  2. ACL, PCL

  3. ACL, PCL, MCL

  4. ACL, PCL, MCL, LCL

 

Discussion

The correct answer is (D). The examination reveals increased anterior and posterior translation consistent with a combined ACL and PCL injury. The varus and valgus laxity suggest an injury to the MCL and LCL.

What physical examination finding should be carefully assessed as a common sequelae of this injury?

  1. Great toe extension

  2. Great toe flexion

  3. Hindfoot inversion

  4. Hindfoot eversion

  5. Heel pad two-point discrimination

 

Discussion

The correct answer is (A). Peroneal nerve palsy occurs in almost one-third of knee dislocations. Evaluation of the nerve’s motor and sensory function is an essential part of a comprehensive examination.

 

Objectives: Did you learn...?

 

 

The initial management of multiligamentous knee injury? The sequelae of MLI?