MR imaging of the Achilles tendon: overlap of findings in symptomatic and asymptomatic individuals

Objective: To differentiate MR imaging characteristics of symptomatic as compared with asymptomatic Achilles tendons. Design: 1.5 T MR images of 94 feet (88 patients) with ”abnormal” MR examinations were retrospectively evaluated and clinically correlated. Two masked, independent observers systematically evaluated for intratendon T2 signal, tendon thickness, presence of peritendonitis, retrocalcaneal bursal fluid volume, pre-Achilles edema, bone marrow edema at the Achilles insertion, and tears (interstitial, partial, complete). These findings were correlated with symptoms (onset and duration) and physical examination results (tenderness, palpable defects, increased angle of resting dorsiflexion). Results: Of the 94 ankles, 64 ankles (32 females, 29 males) were clinically symptomatic. No relationship between Achilles tendon disorders and age or gender was identified. Asymptomatic Achilles tendons frequently demonstrated mild increased intratendon signal (21/30), 0.747 cm average tendon thickness, peritendonitis (11/30), pre-Achilles edema (12/30), and 0.104 ml average retrocalcaneal bursal fluid volume. Symptomatic patients had thicker tendons (0.877 cm), greater retrocalcaneal fluid volume (0.278 ml), more frequent tears (23/64), a similar frequency of peritendonitis (22/64) but less frequent pre-Achilles edema (18/64). Sixty-four percent of the Achilles tendon tears were interstitial. Except for two interstitial tears in control patients, the majority of Achilles tears were in symptomatic patients (14/16). Only symptomatic tendons demonstrated partial or complete tendon tears. In addition, calcaneal edema was found almost exclusively in actively symptomatic patients. Thicker tendons were associated more often with chronic symptoms and with tears. When present in symptomatic patients, peritendonitis was usually associated with acute symptoms. The presence of pre-Achilles edema, however, did not distinguish acute from chronic disorders. Conclusion: There is significant overlap of MR findings in symptomatic and asymptomatic Achilles tendons. Furthermore, there is apparently a spectrum of disease in symptomatic tendons ranging from subtle intratendinous and peritendinous signal to partial and complete tendon tear. Received: 17 March 2000 Revision requested: 26 May 2000 Revision received: 19 July 2000 Accepted: 19 July 2000     

Ultrasound characteristics of the patellar and quadriceps tendons among young elite athletes

Tendons adapt in response to sports‐specific loading, but sometimes develop tendinopathy. If the presence of ultrasound changes like hypoechoic areas and neovascularization in asymptomatic tendons precede (and predict) future tendon problems is unknown. The aim of this prospective cohort study was to investigate the relationship between the development of ultrasound changes in the patellar and quadriceps tendons and symptoms of jumper's knee, as well to examine the medium‐term effects of intensive training on tendon thickness among adolescent athletes. Elite junior volleyball athletes were followed with semi‐annual ultrasound and clinical examinations (average follow‐up: 1.7 years). Of the 141 asymptomatic athletes included, 22 athletes (35 patellar tendons) developed jumper's knee. In a multivariate logistic regression analysis, a baseline finding of a hypoechoic tendon area (odds ratio 3.3, 95% confidence interval 1.1 to 9.2) increased the risk of developing symptoms of jumper's knee. Patellar tendon thickness among healthy athletes did not change (Wilk's lambda, P = 0.07) while quadriceps tendon thickness increased (P = 0.001). In conclusion, ultrasound changes at baseline were risk factors for developing symptoms of jumper's knee. Also, among healthy athletes, we observed a 7–11% increase in quadriceps tendon thickness, while there was no increase in patellar tendon thickness.     

Comparative and morphological analysis of commonly used autografts for anterior cruciate ligament reconstruction with the native ACL: an electron,microscopic and morphologic study

Ligaments and tendons are similar in composition but differ in proportion and arrangement. Tendons are being used as grafts for the ACL reconstruction. Their microscopic structure has not been sufficiently studied and compared to the native ACL. A null hypothesis was declared stating that the anterior cruciate ligament should be histological, morphologically and functionally different from the tendon grafts used for ACL reconstruction. We investigated similarities and differences of the structure of ACL and tendons used as a graft tissue for ACL reconstruction. In this study, standardized samples of quadriceps, hamstrings (semitendinosus and gracilis) and patellar tendons, and the ACL were harvested from 26 autopsies (average age 36.4) and were investigated using light and electron microscopy, immunohistochemistry and morphometry. The thickness of the collagen fibrils, collagen organization and diameter, the fibril/interstitium ratio, density of fibroblasts and blood vessels, and distribution of the collagen type I, III and V fibrils were analyzed. The semitendinosus showed the highest density of fibroblasts and blood vessels, while the gracilis the highest fibril/interstitium ratio. No differences regarding the thickness of collagen fibrils and distribution of fibrils were found. The ACL had the highest concentration of type III and V collagen fibrils as well as elastic fibers. The histological and ultrastructural appearance of the ACL differs from those of the tendons used as graft, for ACL reconstruction. Its ultrastructure is varied and complex, with its collagen fibers bundles lying in many directions.     

Shoulder after rotator cuff repair: MR imaging findings in asymptomatic individuals--initial experience

PURPOSE: To assess the magnetic resonance (MR) imaging appearance of the successfully repaired rotator cuff in an asymptomatic population. MATERIALS AND METHODS: Fifteen subjects who had undergone clinically successful rotator cuff repair were included in the study. All underwent functional testing of the affected shoulder and had good to excellent scores on the Constant scale. Standard MR imaging sequences were performed at 1.5 T, including oblique coronal fast spin-echo T2-weighted MR imaging with fat saturation. RESULTS: Three (10%) of 30 supraspinatus and infraspinatus tendons had normal signal intensity, and 16 (53%) had mildly increased signal intensity on fast spin-echo T2-weighted fat-saturated images, compatible with tendonitis or tendinosis. Three partial and four complete tears of the supraspinatus tendon and two partial and two complete tears of the infraspinatus tendon were seen. Other findings included subacromial-subdeltoid effusion (10 subjects), joint effusions (five subjects), and bone marrow edema (six subjects). CONCLUSION: Postoperative signal intensity changes consistent with tendonitis or tendinosis were common, and clinically "silent" partial and complete rotator cuff tears were seen. Such postoperative MR imaging findings should be interpreted with caution, and meticulous correlation with symptoms and clinical results is recommended.     

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.     

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).     

Ultrasound elastography of the patellar tendon in young,asymptomatic sedentary and moderately active individuals

BackgroundThe recent use of ultrasound elastography to study patellar tendon softness has demonstrated increased tendon softness in high-level athletes. We hypothesized that measurable alterations in patellar tendon softness may be present in young asymptomatic subjects engaging in moderate levels of physical activity.MethodsThis was a cross-sectional study. Gray-scale ultrasound and ultrasound elastography of the right and left patellar tendons were performed in young asymptomatic sedentary subjects and moderately active subjects who engaged in at least 30 min of physical activity 4–5 times weekly. The distribution of soft, intermediate and stiff tissue within each tendon was analyzed. Tendon softness was correlated with subject age, gender and level of athletic activity.ResultsSixty patellar tendons in 30 subjects were evaluated (18 males, 12 females, mean age 22.5 years). Seventeen subjects were defined as “active” and 13 as “sedentary.” All tendons had a normal gray-scale sonographic appearance. Tendon softness was significantly higher in active subjects (P = 0.01) and decreased with age (P = 0.04). In sedentary individuals there was no significant correlation between age and tendon softness (P = 0.404). Similarly, gender showed no correlation with tendon softness (P > 0.05).ConclusionsPatellar tendon softness is higher in young subjects and in those engaging in moderate physical activity. This may reflect an adaptation to increased tendon load. Tendon softness in active subjects decreases with age, while it remains at a constant value in sedentary individuals.Level of evidence: Level 3.     

Quantification of intact quadriceps tendon, quadriceps tendon insertion, and suprapatellar fat pad: MR arthrography, anatomy, and cryosections in the sagittal plane.

OBJECTIVE: The purpose of this study was to quantify quadriceps tendon length, thickness, and insertion in relation to the suprapatellar fat pad. SUBJECTS AND METHODS: We used three methods to analyze the anatomy of intact quadriceps tendons and insertions into the patellar base: MR arthrography (53 knees with intact extensor mechanisms), gross anatomy (16 cadaveric knees), and cryosections (four cadaveric knees). With an electronic cursor, two observers independently quantified the extensor mechanism on midline sagittal T1-weighted spin-echo sequences acquired on a low-field-strength (0.23 T) scanner. RESULTS: On MR arthrograms, quadriceps tendon length, determined from the superior patellar pole to the most superior part of the suprapatellar recess, measured 49 +/- 7 mm in women and 50 +/- 9 mm in men. Thickness of quadriceps tendon at three sites (suprapatellar recess, center, and superior patellar pole) measured 7 +/- 1 mm in women and 8 +/- 1 mm in men. Thickness was significantly larger in men at all measurement locations. Quadriceps tendon insertion and the suprapatellar fat pad along the patellar base measured 16 +/- 2 and 6 +/- 2 mm, respectively, in women, and 18 +/- 3 and 7 +/- 2 mm, respectively, in men. CONCLUSION: On midline MR images, sagittal thickness of the quadriceps tendon and its insertion was significantly larger in men than in women. The prevalence of the suprapatellar fat pad was 100%.     

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.     

Quadriceps fat pad signal intensity and enlargement on MRI: prevalence and associated findings

OBJECTIVE: The purpose of this investigation was to characterize the MRI appearance of the quadriceps fat pad and to correlate the findings with other knee abnormalities, anatomic measurements of the extensor mechanism, and findings from history and at physical examination. MATERIALS AND METHODS: Ninety-two consecutive knee MRI examinations from 84 patients were retrospectively reviewed by two musculoskeletal radiologists for quadriceps fat pad enlargement and signal intensity. Other data from the retrospective review included infrapatellar and prefemoral fat pad signal intensity, quadriceps and patellar tendon abnormalities, joint effusion, medial plica, chondromalacia, articular muscle thickness, and prepatellar edema. The patellar length, patellar articular length, patellar tendon length, and femoral sulcus angle were measured. MRI reports were reviewed for meniscal and ligament abnormalities. Clinical data were reviewed for findings of anterior knee pain in the history and at physical examination. The chi-square and Student's t tests were used to determine significant associations. RESULTS: Twelve percent (11/92) of MRI examinations showed quadriceps fat pad mass effect on the suprapatellar recess, which was associated with intermediate or fluid signal intensity of the quadriceps fat pad (chi(2) = 7.19, p = 0.0274) but with no other findings on knee MRI. Anterior knee pain at physical examination was associated with quadriceps fat pad mass effect (chi(2) = 8.76, p = 0.0031), medial collateral ligament abnormality (chi(2) = 4.83, p = 0.0031), and history of anterior knee pain (chi (2) = 22.76, p < 0.0001). CONCLUSION: Enlargement of the quadriceps fat pad on MRI has a prevalence of 12% and is significantly associated with intermediate or fluid signal intensity of the quadriceps fat pad and anterior knee pain.     

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.     

Patellar tendon morphology in volleyball athletes with and without patellar tendinopathy

Appropriate management of patellar tendinopathy requires distinguishing between inflammatory and degenerative conditions, often difficult because tendon thickening can be a normal or pathological adaptation, and micromorphology is not observable on clinical imaging. The purpose of this study was to quantitatively examine patellar tendon micro‐ and macromorphology in volleyball athletes and relate those findings to reported symptoms. Longitudinal ultrasound images of proximal and distal patellar tendons were acquired from 84 male elite volleyball athletes (44 symptomatic, 40 asymptomatic) and 10 asymptomatic nonathlete controls. Micromorphology was determined using two‐dimensional Fast Fourier Transform analysis providing a discriminating peak spatial frequency parameter (PSF). Macromorphology (patellar tendon thickness) was measured using Image J software. All athletes regardless of symptoms had thicker proximal tendons compared to nonathletes, suggesting a normal adaptation to training loads. However, symptomatic athletes demonstrated lower PSF than asymptomatic athletes and nonathletes at the proximal tendon, suggesting greater collagen disorganization, and tendon degeneration rather than inflammation. Only symptomatic athletes had thicker distal tendons than nonathletes, but there was no difference in PSF distally. Diagnostic ultrasound enhances the understanding of the micromorphology of patellar tendons, supporting the rationale for management that remodels the degenerated tendon instead of treating inflammation.     

ACL reconstruction: patellar tendon versus hamstring grafts—economical aspects

The aim of the present investigation was to compare the costs for the use of patellar tendon versus hamstring tendons as grafts for anterior cruciate ligament (ACL) reconstruction including the different fixation methods. The background is that during recent years there has been a dramatic shift from patellar tendon to hamstring tendons in ACL reconstructions in Sweden. All our patients with ACL reconstructions performed during 1 year (2004) were included. Knee joints numbering 440 in 439 patients were primary ACL reconstructions. A hamstring graft was used in 345 knee joints (78.4%) and a patellar tendon graft in 95 (21.6%) of the patients (Table 2). On average 34 (SD 12.9; range 14–63) ACL reconstructions per surgeon were performed by a total of 14 surgeons. The average cost for patellar tendon procedure was 197 € compared to 436 € for the hamstring procedure. Mean time for surgery in primary reconstructions was 11.5 min shorter (P<0.001) for patellar tendon reconstructions (71.3±31 min) compared to hamstring reconstructions (83.2±27 min). This means a difference in cost of 90 €. The total additional cost (fixation and surgery time) for the hamstring method compared to the patellar tendon method was on an average 329 €. From a strict economic point of view we therefore recommend or at least consider the use of the patellar tendon as a graft in ACL reconstructions.     

Functional capability is enhanced with semitendinosus than patellar tendon ACL repair

The patellar and semitendinosus tendon autograft are the two most common techniques that orthopedic surgeons use to reconstruct the anterior cruciate ligament (ACL). It has not been established, however, whether either of these techniques provides a greater functional advantage to the patient. PURPOSE: To identify patients' functional capabilities after reconstruction of the ACL with a patellar or semitendinosus tendon autograft. METHODS: Forty male soccer players volunteered for the study and were assigned to three homogeneous groups: individuals who had patellar tendon reconstruction (N = 15), individuals who had semitendinosus tendon reconstruction (N = 15), and a control group (N = 10). All patients had undergone surgery 2 yr before this study and received the same rehabilitation training. The testing procedures included measurement of thigh circumference, maximal isometric strength of quadriceps and hamstrings, two- and one-legged jump, squat and gait analysis. Kinetic, kinematic, and electromyographic data were collected. RESULTS: The patellar tendon group exhibited lower (P < 0.05) coactivation of the agonist and antagonist muscles around the knee joint during the squat movement and lower stabilization- and landing degrees during the jumps. Furthermore, the patellar tendon group had a shorter stance phase and reached the first vertical maximum later with the impaired leg while walking (720.2 +/- 15.6 ms vs 740.3 +/- 14.3 ms, and 24.3 +/- 0.64% vs 22.9 +/- 0.74% of stance phase), which was not observed in the semitendinosus tendon and control groups. CONCLUSION: Functional performance is compromised in patients who undergo a patellar tendon graft compared with a semitendinosus graft, possibly due to an altered activation of the quadriceps and hamstring muscles.     

One-stage bilateral anterior cruciate ligament reconstruction with use of hamstring tendon autografts: a case report

This article presents an unusual problem of a patient with chronic bilateral ACL-deficient knees and constitutionally very thin patellar tendons. Author decided to perform one-stage bilateral ACL reconstructions using hamstring tendon autografts so as not to weaken his quadriceps muscles by compromising his extensor mechanism.     

外侧半月板腘肌腱区损伤的缝合方法

目的介绍一种经前方关节镜入路进行全关节内半月板缝合的手术技术,探讨外侧半月板腘肌腱区安全、有效的修补方法。方法2002年7月至2006年5月,共采用经前方入路的全内缝合技术修补外侧半月板腘肌腱区损伤36例,其中合并前交叉韧带损伤26例,单纯桶柄样撕裂2例,盘状软骨损伤8例。常规关节镜前内及前外侧入路,缝合时关节镜置于前外侧入路,前内侧入路为缝合通道。膝关节屈曲90°位内翻,呈“4”字位。将预装配可吸收缝线的缝合钩通过前内侧入路置入关节内,在腘肌腱两侧分别进行缝合,关节内完成垂直褥式缝合、过线、打结、剪线的全部操作步骤。合并前交叉韧带损伤者同时行韧带重建手术,具备修补性的盘状软骨损伤者在修补术之前进行成形术。结果其中30例得到随访,平均随访25.8个月。采用临床检查及二次手术探查对半月板愈合状况进行综合评估。30例可随访病例全部进行了临床检查,均属于“无症状”,其中26例进行了二次手术探查,结果25例完全愈合,1例部分愈合,未发现不愈合病例。无明显手术并发症出现。结论经前方关节镜入路的全关节内缝合技术修补外侧半月板腘肌腱区损伤,可以达到牢靠的缝合效果,有效地避免损伤腘肌腱及腓总神经,获得较好的临床疗效。     

Randomized prospective study of ACL reconstruction with interference screw fixation in patellar tendon autografts versus femoral metal plate suspension and tibial post fixation in hamstring tendon autografts: 5-year clinical and radiological follow-up results

Patellar tendon graft has been the most frequently used material in anterior cruciate ligament (ACL) reconstruction, but the hamstring tendons have been increasingly used as well; however, which graft is to be preferred is not adequately supported by existing clinical studies. In this prospective randomized clinical trial, the study hypothesis was that the hamstring tendons are equally good graft material as the patellar tendon in ACL reconstruction. Ninety-nine patients with laxity due to a torn ACL underwent arthroscopically assisted reconstruction with graft randomization according to their birth year to either patellar tendon with metal interference screw fixation or double looped semitendinosus and gracilis tendons with fixation similar to the Endobutton technique using a titanium metal plate suspension proximally and screw-washer postdistally. Excluding preoperative Lysholm knee score, there were no significant differences between the two groups in the preoperative and operative data. A standard rehabilitation regimen was used for all the patients, including immediate postoperative mobilization without a knee brace, protected weight bearing for 2 weeks, and return to full activity at 6–12 months postoperatively. Forty patients in the patellar tendon group and 39 patients in the hamstring tendon group were available for clinical evaluation at median 5 years after surgery (ranges 3 years 11 months–6 years 7 months). The results revealed no statistically significant differences with respect to clinical and instrumented laxity testing, isokinetic muscle torque measurements, International Knee Documentation Committee ratings, Lysholm (knee score), Tegner (activity level) and Kujala patellofemoral knee scores. There was an enlargement of the drill tunnels, statistically more in the hamstring tendon group, but no increase from 2 to 5 years in either group. Narrowing of the joint spaces (IKDC measurement method) from 2 to 5 years postoperatively was seen in both the groups, however, without difference between the two groups.     

Racial differences in tendon rupture incidence

Despite some anecdotal evidence, the racial differences in tendon injuries have received little attention in the literature. We sought to determine the effect of race on major tendon injuries. A search was performed according to the International Classification of Diseases, Ninth Revision, Clinical Modification code 727.65 (rupture of quadriceps tendon), 727.66 (rupture of patellar tendon), and 727.67 (rupture of Achilles tendon) using the U. S. Defense Medical Epidemiology Database (DMED). Multivariate poisson regression was used to estimate the rate of major tendon rupture per 1000 person-years, while controlling for differences in gender, service, rank, and age for each code. We computed rate ratios and 95% confidence intervals using whites as the referent category. The adjusted rate ratio for black service members when compared to white service members was 2.89 (95% CI 2.42, 3.44) for quadriceps tendon tears, 4.52 (95% CI 3.94, 5.19) for patellar tendon tears, and 3.58 (95% CI 3.31, 3.88) for Achilles tendon tears. There appears to be a significant relative predisposition toward lower-extremity major tendon rupture in black U. S. service members when compared to white service members. Investigation of the racial differences in risk factors is warranted.     

不同移植物重建前交叉韧带疗效比较

目的:比较分别采用自体骨-髌腱-骨(BPB)、四股腘绳肌腱、异体骨-髌腱-骨关节镜下重建膝关节前交叉韧带的临床疗效。方法:选择2006年1月至2010年1月期间获得完整随访的单纯前交叉韧带损伤患者159例,按照移植物不同分为3组:自体腘绳肌腱组、自体骨-髌腱-骨组和异体骨-髌腱-骨组。回顾性分析三组患者术前、术后一般情况,膝关节活动度(ROM)、膝关节稳定性、Lysholm评分及IKDC评分。结果:三组手术前后各项指标有显著差异(P<0.05);术后膝关节活动度(ROM)、膝关节稳定性、Lysholm评分及IKDC评分三组之间未见明显差异(P>0.05);自体骨-髌腱-骨组髌前疼痛发生率为13.89%,显著高于自体腘绳肌腱组和异体骨-髌腱-骨组(P<0.05);异体骨-髌腱-骨组术后需行关节穿刺病例的比率显著高于自体腘绳肌腱组和自体骨-髌腱-骨组(P<0.05),异体骨-髌腱-骨组有1例发生严重感染。结论:三种方法重建前交叉韧带的近期疗效相近,均可以作为前交叉韧带重建选择的移植物;若考虑患者髌前疼痛及感染等情况,自体腘绳肌腱移植物有优势。三种移植物重建前交叉韧带的远期效果还有待进一步研究。     

MRI appearances of the asymptomatic patellar tendon on gradient echo imaging

Thickening of the patellar tendon and foci of increased signal intensity have been described as characteristic features of jumper's knee (chronic patellar tendinitis) on magnetic resonance imaging (MRI). It was our impression that such appearances may be seen in the patellar tendons of patients without symptoms referable to the anterior part of the knee when using gradient echo images. The appearances of the asymptomatic patellar tendon on three-dimensional gradient echo sequences were studied by retrospectively reviewing the images of 60 patients, none of whom had symptoms related to the anterior part of the knee. The anteroposterior width of the patellar tendon was measured at three levels (superior, middle and inferior) on the central sagittal image of a gradient echo sequence. The relative signal intensities at the same levels were recorded. In 97% of subjects the superior part of the tendon was wider than the midpoint, and in 97% the inferior part was wider than the midpoint. The range of widths was wide, and there was no significant difference between sexes. Focal increased signal intensity in the superior part was shown in 75%, and in the inferior part in 43%. The asymptomatic patellar tendon shows uniform thickness throughout most of its length, but there are focal expansions at the proximal and distal ends. It usually demonstrates low signal on MRI, but may contain foci of increased signal intensity at either or both ends when imaged on gradient-echo sequences.