Patellar tendon rupture. The importance of timely recognition and repair

Radiographic Features of Acute Patellar Tendon Rupture

OBJECTIVE

The purpose of our study was to assess soft tissue features of acute patellar tendon rupture on lateral knee radiograph that would facilitate early diagnosis.

METHODS

The participants were divided into two groups of 35 patients each. There were 28 men and seven women with a mean age of 46 years in the control group and 26 men and nine women with a mean age of 47 years in the rupture group. The lateral knee radiograph of each patient was evaluated for Insall-Salvati ratio for patella alta, increased density of the infrapatellar fat pad, appearance of the soft tissue margin of the patellar tendon and bony avulsions.

RESULTS

In the rupture group there were three consistent soft tissue radiographic features in addition to patellar alta. These were increased density of infrapatellar fat pad; loss of sharp, well-defined linear margins of the patellar tendon and angulated wavy margin of the patellar tendon while in the control group these features were not observed.

CONCLUSIONS

The soft tissue radiographic features described in the rupture group are consistent and reliable. When coupled with careful clinical assessment, these will aid in early diagnosis and further imaging will be seldom required.

[Simultaneous rupture of the anterior cruciate ligament and the patellar tendon: a case report]

Simultaneous rupture of both the patellar tendon and the anterior cruciate ligament is a relatively rare injury. Its diagnosis can easily be missed during the initial examination. Treatment options include immediate repair of the patellar tendon with either simultaneous or delayed reconstruction of the ACL. We present the case of a combined rupture of the patellar tendon, the anterior cruciate ligament in a 22-year old footballer. A two-stage treatment approach was performed with an excellent functional outcome.

Acute rupture of the anterior cruciate ligament and patellar tendon in a collegiate athlete

In rare incidences of combined ruptures of the ACL and patellar tendon, either the patellar tendon ruptures or the associated ACL tear is often initially missed. Even when recognized, there is no established treatment regimen. We report a case of an intercollegiate football player with a combined rupture of the ACL and patellar tendon that was successfully treated by primary augmented repair of the patellar tendon along with ACL reconstruction. Similar to other reported cases, the mechanism of injury involved forceful eccentric contraction of the quadriceps against a fixed foot. Superior displacement of the patella with a palpable defect of the patellar tendon, a positive Lachman test, and an inability to perform terminal knee extension noted during the on-field examination indicated the combined injury. Magnetic resonance and radiographic imaging confirmed conclusions from the on-field examination. The patient also underwent safe early mobilization and weight bearing following surgical repair.

Infrapatellar fat pad disruption: a radiographic sign of patellar tendon rupture

After knee trauma, radiographs showing patella alta supercede other signs that suggest patellar tendon rupture. However, without patella alta the diagnosis may be missed. A standard lateral radiograph with the knee flexed showed the infrapatellar fat pad as a dark band with a smooth contour. Our pilot study identified a disruption of the fat pad contour as a radiographic sign of tendon rupture. Two blinded reviewers independently analyzed randomly selected lateral radiographs of the knees of 14 patients with knee injuries. Seven patients had confirmed ruptures diagnosed at surgery, and the other patients had different diagnoses. There were 12 men and two women with an average age of 49 years (range, 20-81 years). One observer detected five of the seven disrupted tendons and six of the seven intact tendons. The other observer detected six of the seven disrupted tendons and all seven intact tendons. Disruption in the contour of the infrapatellar fat pad on routine lateral view radiographs was a reasonably reliable sign of patellar tendon rupture. Diagnostic accuracy should increase when used with the patient's history, physical examination, and other radiographic signs. Absence of this sign should not supersede other suggestive signs of patella tendon rupture.

LEVEL OF EVIDENCE

Diagnostic study, Level II (development of diagnostic criteria on consecutive patients--with universally applied reference "gold" standard). See the Guidelines for Authors for a complete description of levels of evidence.

Rupture of the Achilles and patellar tendons

Certain similarities can clearly be appreciated between Achilles and patellar tendon ruptures. Both are strong tendons that transmit force bridging at least one joint of the lower limb. When healthy, both require massive forces to be disrupted, and both can be weakened through certain systemic disease processes, steroids, and fluoroquinones. Both allow for a variety of innovative management possibilities that ultimately lend themselves to individual surgical preference. We feel that, although surgical management plays an important role in restoring continuity in knee extension and in plantar flexion, functional outcome inevitably relies on patient motivation and a well-established physiotherapy regime. Sports physicians should be able to identify both conditions early in their presentation, but still hold a high index of suspicion for these problems in athletes who have an acute exacerbation of ongoing tendinopathy.