Intra-articular knee injuries in patients with knee extensor mechanism ruptures

The knee extensor mechanism is composed of the quadriceps tendon, patella and patellar tendon. Rupture of either the quadriceps tendon or patella tendon is a rare but significant injury. The purpose of our study is to determine if there are any associated injuries with these ruptures necessitating the need for further evaluation such as MRI or arthroscopy. We retrospectively reviewed all patients with ruptures of the knee extensor mechanism who required operative repair at our institution over the last 10 years. We reviewed the chart for any documented associated injury. The type and incidence of associated injuries were recorded. We further divided these patients into two groups: low energy indirect mechanism or high-energy direct impact mechanism. Sixty-four patients met our requirements for inclusion in this study. Thirty-three patients with patellar tendon ruptures and thirty-one patients with quadriceps tendon ruptures were included. Ten out of 33 (30%) patients with a patellar tendon rupture had an associated injury. Four out of 25 (16%) patients with patellar tendon ruptures in the low energy mechanism category had an associated injury. Six out of 8 (75%) patients with a high-energy direct impact patellar tendon rupture had an associated injury. Three out of 31 (10%) patients with quadriceps tendon rupture had an associated injury. The most common associated injuries in the patellar tendon rupture patients were anterior cruciate ligament tears (18%) and medial meniscus tears (18%). We found almost one-third of all patients with a patellar tendon rupture had an associated intra-articular knee injury. We found 10% of patients with quadriceps tendon rupture had an associated intra-articular knee injury. We also found an even higher incidence of associated injuries in patients with high-energy direct impact mechanism patellar tendon ruptures (75%). The most common associated injuries in patients with patellar tendon ruptures were tears of the anterior cruciate ligament (18%) and medial meniscus (18%). We recommend that consideration be given in obtaining a MRI or diagnostic arthroscopy in patients with patellar tendon ruptures especially those with high-energy direct impact mechanism. To our knowledge this has not previously been documented in the literature.     

Incidence of major tendon ruptures and anterior cruciate ligament tears in US Army soldiers

BACKGROUND: Although a rare event, the prevalence of major tendon rupture has increased in recent decades. Identification of risk factors is important for prevention purposes. HYPOTHESIS: Race is a risk factor for major tendon ruptures. STUDY DESIGN: Cohort study (prevalence); Level of evidence, 2. METHODS: All patients admitted for surgical management of a rupture of a major tendon at Womack Army Medical Center, Fort Bragg, North Carolina, in 1995 and 1996 were identified and evaluated for risk factors. RESULTS: The authors identified 52 major tendon ruptures: 29 Achilles, 12 patellar, 7 pectoralis major, and 4 quadriceps tendon ruptures. All patients were active-duty soldiers, and 1 was a female soldier. Forty-one tendon ruptures occurred among black soldiers, 8 occurred among white soldiers, and 3 occurred among Latino soldiers. The population at risk included 93,224 exposures during the 2-year period, of which 67.1% were white, 24.5% were black, and 8.4% were self-classified as other race. The rate ratio for tendon rupture, adjusted for gender and age, was 13.3 (95% confidence interval, 6.2-28.5) between blacks and whites and 2.9 (95% confidence interval, 0.8-10.9) between Latinos and whites. CONCLUSION: The rate of major tendon rupture was 13 times greater for black men in this study population when compared with whites. Interventions among those at a higher risk for injury should be considered.     

Etiology and pathophysiology of tendon ruptures in sports

Of all spontaneous tendon ruptures, complete Achilles tendon tears are most closely associated with sports activities (1–3). Schönbauer (3) reported that 75% of all ruptures of the Achilles tendon are related to sports. In Plecko & Passl (2) the number was 60%. In our material of 430 cases, the number of sports-related Achilles ruptures was very similar (62%), while only 2% of ruptures of other tendons were sports-related (P<0.001) (1). Also, the majority of Achilles reruptures occurred in sports. The ruptures occurred most often in soccer (34%), track and field (16%) and basketball (14%). The distribution of Achilles ruptures according to different sports varies considerably from country to country, according to the national sport traditions. For example, in northern and middle Europe, soccer, tennis, track and field, indoor ball games, downhill skiing, and gymnastics are the most common; and in North America, football, basketball, baseball, tennis and downhill skiing dominate the statistics (1, 2, 4). In sports, some Achilles ruptures are not spontaneous or degeneration-induced but may occur as a consequence of the remarkably high forces that are involved in the performance (2). Ruptures in the high jump or triple jump are good examples. In such cases, failure in the neuromuscular protective mechanisms due to fatigue or disturbed co-ordination can frequently be found. The spontaneous complete rupture of the supraspinatus tendon of the rotator cuff does not occur very frequently in sports. Those sports that include high-energy throwing movements, such as American and Finnish baseball, American football, rugby and discus and javelin throwing, may, however, produce this injury. Partial tears and inflammations of the rotator cuff complex are much more frequent in throwing sports. The complete rupture of the proximal long head of the biceps brachii tendon is rare among competitive and recreational athletes. In our material, under 2% of these ruptures were associated with sports activities (5). The rupture (avulsion) of the distal tendon of the biceps muscle is rare. In sports, gymnastics, body building and weight lifting have been said to be able to produce this injury (6). In general, complete ruptures of the quadriceps tendon and the patellar tendon occur most often in older individuals. In our study, the mean age of these patients was 65 years (5). However, these injuries do also occur in younger age groups, especially in athletes. In athletes, the rupture most frequently occurs in high-power sports events, such as high jump, basketball and weight lifting, at the age of 15-30 years. A chronic patellar apicitis (jumper's knee) may predispose rupture of the tendon (7). As is the case with the rotator cuff complex, overuse inflammation and partial tears of the quadriceps and patellar tendons are one of the most characteristic athletic injuries. Complete spontaneous ruptures of other tendons in sports are rare, although the literature does provide case studies from almost every tendon the human body possesses (8–18).     

The prevalence of Achilles and patellar tendon injuries in Australian football players beyond a time‐loss definition

Little is known about the prevalence and associated of morbidity of tendon problems. With only severe cases of tendon problems missing games, players that have their training and performance impacted are not captured by traditional injury surveillance. The aim of this study was to report the prevalence of Achilles and patellar tendon problems in elite male Australian football players using the Oslo Sports Trauma Research Centre (OSTRC ) overuse questionnaire, compared to a time‐loss definition. Male athletes from 12 professional Australian football teams were invited to complete a monthly questionnaire over a 9‐month period in the 2016 pre‐ and competitive season. The OSTRC overuse injury questionnaire was used to measure the prevalence and severity of Achilles and patellar tendon symptoms and was compared to traditional match‐loss statistics. A total of 441 participants were included. Of all participants, 21.5% (95% CI : 17.9‐25.6) and 25.2% (95% CI 21.3‐29.4) reported Achilles or patellar tendon problems during the season, respectively. Based on the traditional match‐loss definition, a combined 4.1% of participants missed games due to either Achilles or patellar tendon injury. A greater average monthly prevalence was observed during the pre‐season compared to the competitive season. Achilles and patellar tendon problems are prevalent in elite male Australian football players. These injuries are not adequately captured using a traditional match‐loss definition. Prevention of these injuries may be best targeted during the off‐ and pre‐season due to higher prevalence of symptoms during the pre‐season compared to during the competitive season.     

Achilles tendon ruptures stratified by age, race, and cause of injury among active duty U.S. Military members

A total of 865 members of the U.S. military underwent repair of Achilles tendon ruptures at U.S. military hospitals during calendar years 1994, 1995, and 1996. The discharge summaries of these patients were analyzed for patient demographic information, including age, race, and causative activity. Patients were then stratified by age, race, and cause of injury. Blacks were at increased risk for undergoing repair of the Achilles tendon compared with nonblacks (overall relative risk = 4.15, 95% confidence interval [CI] = 3.63, 4.74; summary odds ratio controlling for age = 3.69, CI = 3.25, 4.19). Participation in the game of basketball accounted for 64.9% of all injuries in black patients and 34.0% of all injuries in nonblack patients. Among those injured, blacks had a significantly increased risk for injury related to playing basketball than nonblacks (relative risk = 1.82, CI = 1.58, 2.10). This finding suggests that there may be other predisposing factor(s) that result in a higher risk of Achilles tendon ruptures in black individuals.     

钼靶摄影诊断跟腱、髌腱运动创伤

<正> 跟腱、髌腱及其附丽区损伤在运动创伤中较为常见,采用临床上使用的钨靶摄影,由于它产生的硬射线对软组织分辨率较差,不易清晰反映出肌腱、韧带等软组织的细节。1970年以来国外研究应用钼靶摄影诊断乳腺疾病,在1979年起国内开始了这方面报道,但仍以诊断乳腺疾病为主。我院1979年用于诊断运动创伤疾病,一年共摄片276张,发现它对显示跟腱、髌腱等软组织变化效果较好。现将临床使用和诊断依据作一介绍。     

The patellar tendon: thickening,internal signal buckling,and other MR variants

We studied the range of appearance of asymptomatic patellar tendons and evaluated the effect of age, weight, joint effusions, and anterior cruciate ligament (ACL) tears on this tendon. One hundred and seventy-three patellar tendons in asymptomatic patients were studied at 1.5 tesla. Sagittal short and long TE images were evaluated in regard to tendon thickness, ratio of thickness of patellar to quadriceps tendons, frequency, location, and severity of intratendon signal, and frequency and severity of tendon buckling. Results were correlated with patient age, sex, weight, the presence of ACL tears, and relative volumes of joint fluid. The mean thickness of the patellar tendon was 0.52 cm. The patellar to quadriceps tendon ratio was 0.72. The patellar tendon frequently (74%) had focal areas of signal apparently within it. This signal was usually subtle, V-shaped (95%), and seen posteriorly in the proximal end of the tendon (82%). Intratendon signal was also seen commonly in the inferior aspect of the tendon (32%). This signal intensity did not increase with greater T2-weighting (99%). Buckling of the patellar tendon was a frequent asymptomatic variant (71%) but was also associated with joint effusions (p<0.01) and ACL tears (p=0.01). Buckling, intratendon signal, and tendon thickness increased with weight and age. Variation of the magnetic resonance appearance of the patellar tendon is frequent. Many of these changes appear to represent subclinical degeneration. Buckling of this tendon also may occur secondary to joint effusions or ACL tears.     

Magnetic resonance imaging in acute tendon ruptures

The diagnosis of acute tendon ruptures of the extensor mechanism of the knee or the Achilles tendon of the ankle may usually be made by clinical means. Massive soft tissue swelling accompanying these injuries often obscures the findings, however. Magnetic resonance imaging (MRI) can rapidly demonstrate these tendon ruptures. Examples of the use of MRI for quadriceps tendon, and Achilles tendon rupture are presented.     

Sonographic incidence of tendon microtears in athletes with chronic Achilles tendinosis

OBJECTIVE: To assess the number and distribution of tendon microtears in asymptomatic controls and athletes with chronic Achilles tendinitis or partial thickness tears using high resolution ultrasound. METHODS: The mean number of microtears in three random tendon cross sections were recorded per tendon third in 19 asymptomatic volunteers, 16 athletes with symptomatic chronic Achilles tendinitis, and eight athletes with partial Achilles tendon rupture. RESULTS: Microtears were most numerous in the middle third section of the Achilles tendon. Some 67% of tendons in the control group had no microtears, and 28% showed a single microtear. Only 18% of the athletes with chronic Achilles tendinitis and none of the athletes with partial tendon rupture were without microtears in the middle third of their Achilles tendon. Of the tendons with chronic tendinitis, 13% had more than three microtears per section which increased to 87% in tendons exhibiting partial rupture. CONCLUSIONS: There appears to be an association between microtear formation and Achilles tendon rupture.     

Asymptomatic Achilles,patellar, and quadriceps tendinopathy: A longitudinal clinical and ultrasonographic study in elite fencers

Lower limb tendon changes detected at imaging are common among asymptomatic athletes. We aimed to prospectively assess the clinical status, tendon structure, and vascularity of lower limb tendons of elite fencers, and predict the risk of developing symptoms over time. Clinical examination, changes at ultrasonography (US), and Power Doppler (PD) flow of both the Achilles, patellar, and quadriceps tendon were assessed in 37 elite fencers in January 2007 and 3 years after. Two hundred and twenty‐two tendons were examined. At the last appointment, patellar tendons diagnosed as abnormal at baseline were more likely to develop symptoms than those normal at baseline (P < 0.05, Fisher's exact test), while US and PD abnormalities on Achilles and quadriceps tendons were no predictive for development of symptoms over years. A very low percentage of tendons diagnosed as normal at baseline (1.45%) showed US abnormalities at 3‐year follow‐up. In asymptomatic elite fencers, structural changes are relatively common at US and PD assessment of Achilles, quadriceps, and patellar tendons. It seems unlikely that additional PD investigations provide further information or change prognosis in patients with US diagnosis of tendinopathy.     

Knee dislocations: a magnetic resonance imaging study correlated with clinical and operative findings

OBJECTIVES: Our objectives were to determine retrospectively the prevalence, patients' demographics, mechanism of injury, combination of torn ligaments, associated intra-articular and extra-articular injuries, fractures, bone bruises, femoral-tibial alignment and neurovascular complications of knee dislocations as evaluated by magnetic resonance (MR) imaging. MATERIALS AND METHODS: From 17,698 consecutive knee examinations by magnetic resonance imaging (MRI) over a 6-year period, 20 patients with knee dislocations were identified. The medical records of these patients were subsequently reviewed for relevant clinical history, management and operative findings. RESULTS: The prevalence of knee dislocations was 0.11% [95% confidence interval (95% CI) 0.06-0.16)]. There were 16 male patients and four female patients, with ages ranging from 15 years to 76 years (mean 31 years). Fifteen patients had low-velocity injuries (75%), of which 11 were amateur sports related and four were from falls. Four patients (20%) had suffered high-velocity trauma (motor vehicle accidents). One patient had no history available. Anatomic alignment was present at imaging in 16 patients (80%). Eighteen patients had three-ligament tears, two had four-ligament tears. The four-ligament tears occurred with low-velocity injuries. The anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) were torn in every patient; the lateral collateral ligament (LCL) was torn in 50%, and the medial collateral ligament (MCL) in 60%. Intra-articular injuries included meniscal tears (five in four patients), fractures (eight in seven patients), bone bruises (15 patients), and patellar retinaculum tears (eight partial, two complete). The most common extra-articular injury was a complete biceps femoris tendon tear (five, 25%). There were two popliteal tendon tears and one iliotibial band tear. One patient had received a vascular injury following a motor vehicle accident (MVA) and had been treated prior to undergoing MRI. Bone bruises (unrelated to fractures), four-ligament tears, biceps femoris tears, and popliteus tendon tears were encountered only in the low-velocity knee dislocations. Twelve were treated surgically, five conservatively, and three had been lost to follow-up. The biceps femoris tendon was repaired in every patient who was treated surgically. CONCLUSIONS: Knee dislocations occurred more commonly in low-velocity injuries than in high-velocity injuries, predominantly affecting amateur athletes. Biceps femoris tendon tears were the most common extra-articular injury requiring surgery. Neurovascular injury (5%) was uncommon. At imaging, femoral-tibial alignment was anatomic in the majority of patients.     

Patellar and quadriceps tendon ruptures--jumper's knee

We reviewed 13 patients with end stage jumper's knee, 10 with patellar tendon ruptures, and 3 with ruptures of the quadriceps tendon to evaluate our long-term results in treating these tendon ruptures in an athletic population. The focus was on the natural history, the time until return, and the level of return, to athletic activity. Jumper's knee affected all patients to a varying degree prior to rupture. Basketball was the most common sport involved. At followup, averaging 4 1/2 years, patients underwent functional and clinical, as well as Cybex and roentgenographic, evaluations. Results indicated patellar tendon ruptures, where the ruptures are complete, have a more favorable prognosis than those of the quadriceps tendon which are incomplete. All of the latter patients continued to have quadriceps tendinitis following repair. In both groups, the poor results were obtained in patients with chondromalacia and/or patella alta. Cybex testing yielded results of greater than 100% strength in three patients with patellar tendon ruptures, but no patient with quadriceps rupture had comparable test results. There was no apparent relationship between ruptures and cortisone injections. Patellar and quadriceps tendon ruptures from indirect injury in athletes represent the end stage of jumper's knee and result from repetitive microtrauma. Excellent function usually follows repair of patellar tendon ruptures when surgery is performed early and care is taken to restore normal patellar tendon length. Results of quadriceps ruptures are less satisfactory since these ruptures are usually incomplete and all degenerative tissue may not be involved in the healing response.     

The wrinkled patellar tendon: an indication of abnormality in the extensor mechanism of the knee

Rupture of the quadriceps tendon is an uncommon condition which requires early diagnosis and treatment to avert prolonged disability. In four patients who had surgically confirmed quadriceps tendon rupture, lateral radiographs of the knee and/or sagittal magnetic resonance (MR) images demonstrated a corrugated appearance to the patellar tendon. Sagittal MR images of the knee following patellectomy in one patient and radiographs of a transverse fracture of the patella in another also demonstrated this appearance. MRI has superb contrast resolution which provides optimal visualization of the contour of the patellar tendon on sagittal images. A retrospective review of 50 consecutive knee MRI examinations was carried out to evaluate the appearance of the normal patellar tendon. In 49 of 50 patients, the sagittal images demonstrated a straight or nearly straight patellar tendon. A corrugated appearance of the patellar tendon on sagittal images indicates a reduction in the normal tensile force applied to it and indicates the need for careful evaluation of the patella and quadriceps tendon mechanism.     

Injuries to the distal gastrocnemius muscle: MR findings

PURPOSE: The purpose of this work was to demonstrate the MR findings of injuries to the distal gastrocnemius muscle. METHOD: Twenty patients with clinically confirmed injuries to the distal gastrocnemius muscle underwent MRI. The injuries were evaluated with regard to abnormal morphology or signal abnormality, site, and degree of tearing. RESULTS: Twenty-three injuries to the distal gastrocnemius occurred in 20 patients, with involvement of the myotendinous junction in 22 of 23 (96%) injuries. An interstitial tear of the proximal Achilles tendon was present in one instance. Myotendinous strains were the most common injuries (10/23; 43%); partial tears (7/23; 30%) and complete tears (5/23; 22%) of the myotendinous junction or proximal Achilles tendon were less frequent. When an injury to the gastrocnemius myotendinous junction was present, involvement of the medial head (19/22; 86%) was more frequent than involvement of the lateral head (3/22; 14%). CONCLUSION: MRI allows accurate imaging of distal gastrocnemius muscle injuries. When occurring, distal gastrocnemius muscle injuries most frequently involve the myotendinous junction of the medial gastrocnemius head and occasionally the lateral gastrocnemius head or the proximal Achilles tendon.     

Achilles tendon injuries: the role of MR imaging

Eight magnetic resonance (MR) examinations were performed in seven patients with Achilles tendon injuries and correlated with physical examination and surgical and clinical follow-up. The MR examinations depicted the Achilles tendon in excellent detail and Achilles tendon abnormalities with greater accuracy than physical examination. Of five tendons shown to be at least partially torn on MR, palpable tendinous defects were found in only one, and plantarflexion weakness was found in four. The MR and surgical findings precisely correlated in one case. Magnetic resonance proved valuable in the evaluation of clinically equivocal Achilles tendon tears and may ultimately play a greater role as a research tool in the determination of optimal forms of therapy for specific Achilles tendon injuries.     

Isokinetic evaluation of anterior cruciate ligament reconstruction: quadriceps tendon versus patellar tendon

AIM: The goal of this prospective randomized study was to compare the isokinetic recovery of thigh strength after anterior cruciate ligament (ACL) reconstruction by using patellar or quadriceps tendon as graft at the 6th month follow-up. METHODS: The authors evaluated 48 patients who underwent arthroscopic ACL reconstruction using patellar tendon (PT group) or quadriceps tendon (QT group) as autograft after a 6 months follow-up undergoing the following tests: the Ergojump Bosco System springboard and Universal's FITNET computerized isokinetic system. RESULTS: The counter movement jump (CMJ) test showed a 24% (p<0.01) strength deficit in patients operated with patellar tendon and 11% in the quadriceps tendon group. Also in the leg press test the greater differences in strength (p<0.05) were verified in the patellar tendon group, above all the peak torque (PT) test carried out at 3 repetitions (15%). CONCLUSIONS: The strength deficit found in the subjects operated with quadriceps tendon were statistically lower in comparison to that verified in the patellar tendon group. A good recovery in thigh strength after 6 months in patients operated with quadriceps tendon could encourage the use of this kind of graft in order to achieve an easier rehabilitation and a faster release of the patient to daily and sports activity.     

Achilles tendinopathy after treatment with fluoroquinolone

Fluoroquinolone antibiotic therapy is a recognized but poorly understood cause for Achilles tendinopathy. We report here a patient who developed bilateral partial Achilles tendon tears as a result of fluoroquinolone therapy. Ultrasound and MRI were both useful in identifying and distinguishing between Achilles tendinosis and tendon rupture. The current published literature on this problem was also reviewed.     

Surgical treatment of acl-pcl-medial side-lateral-side injuries of the knee

The multiple-ligament-injured knee is a complex problem in orthopaedic surgery. Most dislocated knees involve tears of the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), and at least one collateral ligament complex. Careful assessment of the extremity vascular status is essential because of the possibility of arterial and/or venous compromise. These complex injuries require a systematic approach to evaluation and treatment. Physical examination and imaging studies enable the surgeon to make a correct diagnosis and to formulate a treatment plan. Arthroscopically assisted combined ACL/PCL reconstruction is a reproducible procedure. Knee stability is improved postoperatively when evaluated by using knee-ligament rating scales, arthrometer testing, and stress radiographic analysis. Acute medial collateral ligament tears when combined with ACL/PCL tears may, in certain cases, be treated with bracing. Posterolateral corner injuries combined with ACL/PCL tears are best treated with primary repair, as indicated, combined with reconstruction by using a post of strong autograft (split biceps tendon, biceps tendon, semitendinosus) or allograft (Achilles tendon, bone—patellar tendon—bone) tissue. Surgical timing depends on the ligaments injured, the vascular status of the extremity, reduction stability, and the overall health of the patient. We prefer the use of allograft tissue for reconstruction in these cases because of the strength of these large grafts and the absence of donor-site morbidity.     

MR imaging of the knee. Part I. Traumatic disorders

One hundred thirty patients with a diversity of knee joint injuries were evaluated with a high-resolution magnetic resonance (MR) imaging technique. The authors report the accuracy of this technique in the evaluation of 105 patients with suspected meniscal tears, 26 patients with suspected cruciate ligament tears, and eight patients with suspected patellar tendon injuries. Of those menisci rated as definitely or probably torn on MR imaging, 80% were found to be torn at subsequent arthroscopy. The predictive value of negative MR imaging results was 100%. MR imaging was 92% accurate in predicting the clinical outcome in patients with suspected meniscal tears who did not undergo surgery. MR permitted complete disruption of the patellar tendon to be differentiated from partial tears, ligamentous inflammation, and localized effusion of the infrapatellar bursa. Injuries to the anterior and posterior cruciate ligaments were identified on MR images, and the status of synthetic grafts of the anterior cruciate ligament was ascertained.