5. Sports Medicine MCQs

DISCUSSION: Proximal tibial osteotomy is the most appropriate intervention to correct varus malalignment and to reduce stress on the ACL. In some cases, proximal tibial osteotomy alone may address both pain and instability, but if instability persists, particularly in the setting in which instability can be dangerous, subsequent ACL reconstruction can further stabilize the knee with less stress on the graft after the correction of malalignment. Varus alignment places increased stress on the native or reconstructed ACL. ACL reconstruction should be performed only at the same time as or following proximal tibial osteotomy to correct alignment in the setting of varus malalignment. It is not appropriate to perform ACL reconstruction prior to proximal tibial osteotomy in this setting. Distal femoral osteotomy is not indicated to correct varus malalignment. Varus alignment places increased stress on the native or reconstructed ACL, and ACL reconstruction alone is not indicated for this patient.

DISCUSSIONThe MR image shows an osteochondritis dissecans (OCD), which is an acquired lesion of the subchondral bone. Patients with OCD initially report nonspecific pain and variable amounts of swelling. Initial radiographs help to identify the lesion and establish the physes status. MRI is useful for assessing potential for the lesion to heal with nonsurgical treatment. This lesion is unstable, considering the fluid line between the OCD and the underlying normal bone. Nonsurgical treatment is appropriate for small, stable lesions in patients with open physes and focuses on activity restriction for 3 to 9 months. Surgical treatment is necessary to address unstable or detached lesions. Stable lesions with intact articular cartilage can be treated with subchondral drilling to stimulate vascular ingrowth, with radiographic healing at an average of 4.4 months. Fixation is indicated for unstable or hinged lesions, and stabilization of the fragment can be achieved using a variety of implants through an arthroscopic or open approach. The fragment should be salvaged and the normal articular surface restored whenever possible.

DISCUSSION: Vascular complications during TKA are rare but do occur. Traditionally, it was taught that the popliteal artery was situated posterior to the PCL; however, more recent anatomic dissections have demonstrated that this artery is usually located posterolateral to the PCL.

DISCUSSION:This patient has symptomatic femoroacetabular impingement as well as clinical and radiographic signs of acetabular retroversion, including a cross-over sign, ischial spine sign, and posterior wall sign bilaterally. Good   midterm   to   long-term   outcomes   have   been   reported   with   reverse   (anteverting)   Bernese periacetabular osteotomy (PAO). In patients with less retroversion, open or arthroscopic rim trimming with labral refixation have shown good short-term results, but longer-term results have yet to be fully delineated. Isolated  hip  arthroscopy  and  labral  repair  would  not  be  indicated  without  addressing  the retroversion  deformity.  Femoral  varus  rotational  osteotomy  plays  no  role  in  the  treatment  of  this pathology.  Open  surgical  dislocation  with  rim  trimming  could  be  considered  in  patients  with  less deformity, but some studies have shown inferior long-term results compared with reverse PAO.

With subscapularis tendon ruptures that have biceps tendon pathology, treatment with tenodesis or tenotomy has improved clinical results. Subluxation or dislocation of the biceps tendon is common with subscapularis rupture. Dislocation of the biceps can occur either beneath the tendon, within the tendon, or extra-articularly. In all cases,the restraints to medial translations of the biceps have been disrupted. Attempts at recentering the biceps have not been successful, and clinical results appear to be improved when tenodesis or tenotomy is employed in the treatment of the unstable biceps associated with subscapularis tears.

The ACL is composed of two anatomic bundles: the anteromedial (AM) and the posterolateral (PL). They are both considered important to the stability of the knee. Although they work in concert, the AM bundle controls translation, especially in flexion, whereas the PL bundle prevents rotation.

The MRI scan shows bone bruises in the medial aspect of the patella and the lateral aspect of the lateral femoral condyle. Both of these signs are typical for a lateral dislocation of the patella with spontaneous reduction. In addition, there may be associated tearing of the medial retinaculum or distal aspect of the vastus medialis.

The patient underwent an osteochondral autograft transfer (OAT) with multiple plugs (also known as mosaicplasty) for a full-thickness chondral defect of the medial femoral condyle. The chondrocytes in the graft remain viable, the transferred cartilage heals, and biopsy reveals articular cartilage composed primarily of type II collagen.Articular cartilage defects can be treated by a variety of methods including debridement, fixation of unstable osteochondral fragments, marrow stimulation techniques (microfracture, abrasion chondroplasty), cartilage replacement techniques (osteochondral autograft and allograft) and cellular techniques (autologous chondrocyte implantation). Osteochondral autograft transfer is performed by harvesting normal articular cartilage with underlying bone from lesser weightbearing areas (e.g. intercondylar notch) and transferring the graft to a recipient socket at the site of the chondral defect. Graft incorporation occurs by integration of the bony graft into the subchondral bone and healing of the overlying cartilage layer.Hangody et al. reviewed the outcomes of autologous osteochondral mosaicplasty in professional athletes. They found successful outcomes similar to that of less athletic patients, despite a higher rate of preoperative osteoarthritic changes in the athletic population. The authors noted that histological evaluation revealed good graft incorporation in all 11 cases.Alford et al. authored a two part Current Concepts article on cartilage restoration. They constructed an algorithm (Illustration A) highlighting many factors that impact treatment choice, including patient activity level and defect characteristics such as location and size. This algorithm also illustrates comorbidities (malalignment, ligament insufficiency) that warrant correction prior to addressing the chondral defect.Figure A shows a full-thickness chondral defect (left) and subsequent osteochondral autograft transfer (right). Illustration A is a treatment algorithm for the management of chondral defects, as discussed above. Illustration B shows a microfracture procedure, a marrow stimulation technique resulting in fibrocartilage filling of the chondral defect. Illustration C shows an osteochondral allograft transplant, a cartilage replacement technique useful for large defects in which donor graft is obtained from a cadaver hemicondyle and transferred to a recipient socket at the site of the chondral defect. Illustration D shows the autologous chondrocyte implantation technique, a two-stage procedure consisting of 1. Cartilage biopsy for growth of autologouschondrocytes, and 2. Subsequent injection of autologous chondrocytes beneath a periosteal patch.Incorrect

An avulsion fracture from the lateral tibial margin carries the eponym Segond fracture and is pathognomonic for an anterior cruciate ligament (ACL) tear. The fragment is located posterior to Gerdy’s tubercle and is superior and anterior to the fibular head. It represents an avulsion of the lateral capsular ligament of the knee and is caused by the same mechanism that causes the ACL tear. The pes anserinus is the insertion point of the medial hamstrings and would not be affected in a lateral avulsion injury. The posterior cruciate ligament may be seen on a lateral view if associated with an avulsion fragment, but a tear of the PCL generally cannot be diagnosed on an AP view. The insertion of the iliotibial band is broad and is unlikely to produce an avulsion injury such as that seen in the radiograph. This view is not consistent with the appearance of a lateral collateral ligament injury.

MRI reveals an anterior labral tear, and the radiograph shows minimal arthritis with possible dysplasia. The most common location of pain in patients with a labral tear is the groin, and the most common physical finding is a positive impingement test result. Pain during sitting, clicking, and buttock pain are frequently described by patients with a labral tear, but these symptoms are less common than groin pain. A positive posterior impingement test finding is more common in patients with a posterior labral tear. Although age over 40 years and a body mass index higher than 30 can adversely affect clinical outcomes after joint preservation procedures such as PAO, hip arthroscopy, and femoral acetabular impingement surgery, the presence of hip arthritis on presurgical radiographs is the most commonly mentioned cause of failed hip joint preservation surgery. Tönnis grade is a radiographic measure of hip arthritis. A higher Outerbridge score is associated with more frequent poor outcomes after hip arthroscopy; however, the Outerbridge cartilage score is determined by direct visualization at the time of surgery. The Outerbridge score cannot be determined presurgically.

The MRI scans show that edema is noted on the femoral insertion of the ACL consistent with a high-grade or complete ACL tear. The ACL is not visualized on the sagittal view, although the torn meniscus can be seen in the notch. On the coronal image, there is an empty lateral wall sign indicating proximaldisruption of the ACL. The medial meniscus images show a disruption of normal meniscus morphology consistent with a bucket handle medial meniscus tear. Note the appearance on the sagittal MRI scan of what appears to be a second soft-tissue density in line with the PCL. This "double PCL" sign is highlyindicative of a displaced medial meniscus tear rather than a displaced lateral meniscus tear.

The appropriate placement of the anterolateral portal provides access to the lateral gutter of the joint while avoiding the superficial peroneal nerve. The safest location for the portal is approximately 4 mm lateral to the peroneus tertius tendon, the closest of the tendons listed to the anterolateral portal. Because the superficial peroneal nerve location is variable, attempts to visualize, palpate, or transilluminate the nerve are mandatory.

MRI reveals an anterior labral tear, and the radiograph shows minimal arthritis with possible dysplasia. The most common location of pain in patients with a labral tear is the groin, and the most common physical finding is a positive impingement test result. Pain during sitting, clicking, and buttock pain are frequently described by patients with a labral tear, but these symptoms are less common than groin pain.

The structure shown is the posterolateral bundle of the anterior cruciate ligament (ACL). This bundle is optimally positioned in the knee to resist rotatory forces during terminal knee extension. "Resist anterior translation during knee flexion" best describes the anteromedial bundle. "Resist rotatory loads during knee flexion" is unlikely because the posterolateral bundle is tightest during knee extension. The posterior cruciate ligament, not the ACL, functions to resist posterior translation.

Numerous experimental studies have shown that vertical suture techniques are superior to all of the other noted methods. In fact, vertical sutures have been shown to be twice as strong as several of these techniques.

The T2-weighted sagittal MRI scan shows the classic "bone bruise" pattern seen with an anterior cruciate ligament (ACL) tear. These lesions are thought to represent subcortical trabecular hemorrhages and are manifested as an increase in signal intensity on T2-weighted images and diminished signal intensity on T1-weighted images. They are classically located in the mid-portion of the lateral femoral condyle and posterior aspect of the lateral tibial plateau. This is due to the fact that an ACL tear typically is the result of a valgus-external rotation of the femur on the fixed tibia. This places most of the weight-bearing stress on the lateral femoral condyle, which rotates laterally and impacts the posterior lip of the lateral tibial plateau. This may result in an impaction fracture if the force is great enough, but more frequently causes merely a microfracture of the involved subcortical trabeculae.

The radiograph shows the correct tibial tunnel and anterior femoral tunnel; therefore, range of motion will most likely show loss of flexion.

Chronic subscapularis tendon ruptures preclude primary repair. In such instances, subcoracoid pectoralis major tendon transfers may improve function and diminish pain. The subcoracoid position of the transfer allows redirection of the pectoralis major in a direction recreating the vector of the subscapularis tendon. Shoulder fusion is a salvage procedure, and corticosteroid injection may reduce pain but will not improve function.

The sagittal T1-weighted MRI scan is useful for interpreting the quality of muscle. The arrow is pointing to the teres minor.

Deficiency of the rotator cuff interval may be acquired or congenital. In this patient, extensive debridement of the rotator cuff interval capsule at the time of arthroscopy most likely is the cause of the defect seen on the MRI scan. Surgical closure of the defect is the treatment of choice. During the repair, the shoulder should be placed in 30 degrees of external rotation to avoid overtightening. Care should be taken to include the leading edge of both the supraspinatus and subscapularis tendons in the repair because the rotator cuff interval capsular tissue is likely to be of poor quality.