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.     

单纯后交叉韧带断裂继发关节内损伤的临床研究

自 1 973年至 2 0 0 2年间我所诊治单纯后交叉韧带断裂共 5 4例 ,其中进行了关节内探查的有 40例 ,急性伤 9例 (≤ 6周 ) ,慢性伤 3 1例 ( >6周 )。分别对这 40例病例的关节软骨损伤发生率、损伤部位和损伤程度及半月板损伤的发生率、损伤部位及损伤类型进行了统计学研究 ,同时对前、后交叉韧带断裂之间和运动员与非运动员之间的继发关节内损伤进行了统计学比较 ,对创伤机制也进行了相应的研究。结果显示 ,后交叉韧带断裂最常见创伤机制为胫前伤 ( 5 1 85 % )。非运动员中摩托车伤最多见 ( 2 3 5 3 % )。伤后慢性期软骨损伤发生率明显高于急性期 (P <0 0 5 )。前、后交叉韧带断裂后急性期与慢性期之间及运动员与非运动员之间软骨损伤发生率无明显差异。后交叉韧带断裂后软骨损伤最易发生于髌股关节 (P <0 0 1 ) ,其次为股骨内髁负重区 ,与前交叉韧带断裂更易发生于内、外髁相比 ,明显不同。非运动员软骨损伤程度要重于运动员 (P <0 0 5 )。后交叉韧带断裂后急慢性期半月板损伤发生率相近。慢性期外侧半月板损伤居多 (P <0 0 1 )。运动员更易发生半月板损伤 (P <0 0 1 )。后交叉韧带断裂后内外侧半月板损伤均少于前交叉韧带 ,慢性期尤甚 (P <0 0 0 1 )。后交叉韧带断裂后半月板损伤的部位以外侧     

Knee laxity after complete anterior cruciate ligament tear: a prospective study over 15 years

There is limited knowledge of knee laxity in the long term after a complete anterior cruciate ligament (ACL) tear treated without ACL reconstruction. The aim of this study was (1) to describe the clinical course of knee laxity after a complete ACL tear over 15 years, and (2) to study the association between knee laxity and meniscal injuries and the development of knee osteoarthritis (OA). We studied 100 consecutive subjects [mean (SD) age 26 (8) years] presenting with acute ACL injury prospectively. The initial treatment in all subjects was knee rehabilitation without reconstructive surgery. The subjects were examined with Lachman's and pivot‐shift tests at baseline, 6 weeks, 3 months, 1 year, 3 years and 15 years after the injury. Sagittal knee laxity was also evaluated with the KT‐1000 arthrometer at the 15‐year follow‐up. During follow‐up, 22 subjects were ACL reconstructed due to unacceptable knee instability. There was only a mild remaining knee laxity [median Lachman grade and pivot‐shift test value of 1 on a 4‐grade scale (0–3)] after 15 years in subjects treated without primary ACL reconstruction. Knees with higher anterior sagittal knee laxity 3 months after the injury had a worse long‐term outcome with respect to meniscal injuries and knee OA development.     

Did injury incidence in alpine ski racing change after equipment regulations? An evaluation based on the injury surveillance system of the Austrian Ski Federation

ObjectivesTo assess the effects of alpine competition equipment regulations from 2003, 2007 and 2012 on severe injury incidence.DesignCase studyMethodData originated from records of the injury surveillance system of the Austrian Ski Federation. Injuries from the seasons 2001–2017 were divided in four periods between the equipment regulations. For comparison of consecutive periods, risk ratios (RR = later period / preceding period) with 95% CI were calculated. Total severe injury events, events with severe knee injuries, and events with severe ACL injuries were separately investigated.ResultsA significant increase of total severe injury incidence was found after the equipment regulation in 2003 (RR 1.52, 95% CI 1.00–2.31). None of the other comparisons revealed significance (p < 0.05) or statistical trends (p < 0.1). Only the minority (40%) of the RR showed a reduction in the injury incidence of the Austrian Ski Team (lowest RR 0.78). 60% of the RR increased after the regulations (highest RR 1.63).ConclusionsEven though statistical uncertainties remain, our findings allow the conclusion, that the implemented equipment regulations did not cause a noticeable reduction of injuries. The three analysed equipment regulations were not appropriate or were counteracted by other factors.     

Management of anterior cruciate ligament injuries in skeletally immature adolescents

Anterior cruciate ligament (ACL) injuries in skeletally immature adolescents are bein diagnosed and reported with increasing frequency. Nonoperative management of midsubstance ACL injuries in adolescent athletes frequently results in a high incidence of giving-way episodes, recurrent meniscal tears, and early onset of osteoarthritis. An intraarticular ACL reconstruction (using the central 10-mm patellar tendon graft) in young athletes approaching skeletal maturity provides predictable excellent knee stability, and the athletes are able to return to competitive sports with a decreased risk of recurrent meniscal and/or chondral injury. Guidelines for the management of ACL injuries in skeletally immature adolescents are presented.     

运动员与非运动员前交叉韧带断裂后继发膝关节软骨损伤的临床对比研究

目的通过对21例运动员与43例非运动员膝关节前交叉韧带(ACL)断裂后并发膝关节软骨损伤的观察,分析探讨其损伤继发关节软骨损伤的原因及规律。方法应用膝关节镜观察关节软骨损伤的部位、病理改变、损伤程度,然后对损伤发生率、发生时间、损伤程度与病程的关系进行对比研究。结果软骨损伤总发生率为75%,运动员组为66.7%,非运动员组为79%,非运动员组软骨损伤发生率明显高于运动员组(P＜0.01),病程超过1年后关节软骨损伤明显加重(P＜0.01),但两组间差别不显著(P＞0.05)。结论运动员与非运动员ACL断裂后膝关节软骨损伤率明显增高,损伤程度随病程延长而加重。ACL断裂后继发关节软骨损伤的主要原因是膝关节不稳。     

Altered hip control during a standing knee-lift test is associated with increased risk of knee injuries

A few prospective studies have investigated hip and pelvic control as a risk factor for lower extremity (LE) injuries. The purpose of this study was to investigate whether deficits in hip and lumbopelvic control during standing knee-lift test are associated with increased risk of acute knee and LE injuries in youth team sports. At baseline, 258 basketball and floorball players (aged 12-21 years) participated in a standing knee-lift test using 3-dimensional motion analysis. Two trials per leg were recorded from each participant. Peak sagittal plane pelvic tilt and frontal plane pelvic drop/hike were measured. Both continuous and categorical variables were analyzed. New non-contact LE injuries, and match and training exposure, were recorded for 12 months. Seventy acute LE injuries were registered. Of these, 17 were knee injuries (eight ACL ruptures) and 35 ankle injuries. Risk factor analyses showed that increased contralateral pelvic hike was significantly associated with knee injury risk when using categorical variable (HR for high vs low group 4.07; 95% CI 1.32-12.6). Furthermore, significant association was found between high lateral pelvic hike angles and ACL injury risk in female players (HR for high vs low group 9.10; 95% CI 1.10-75.2). Poor combined sensitivity and specificity of the test was observed. In conclusion, increased contralateral pelvic hike is associated with non-contact knee injury risk among young team sport players and non-contact ACL injuries among female players. More research to determine the role of pelvic control as a risk factor for knee injuries is needed.     

Recording injuries only during winter competitive season underestimates injury incidence in elite alpine skiers

Current epidemiological studies in elite alpine skiers are mostly limited to retrospective surveys on in-season injury. The aim of this study was to determine the risk and pattern of injury in elite alpine skiers during the winter competitive season (WCS) and the summer off-season (SOS). European Cup skiers were prospectively followed during 5 complete years. A total of 133 skier-seasons (79 males and 54 females) completed the study. All acute and overuse injuries that required medical attention were registered, representing a total of 166 injuries. Absolute injury incidence was 124.8 (95% CI [106-145]) injuries per 100 athletes per complete season and was higher during the WCS compared with the SOS, albeit in a smaller magnitude than expected (relative risk ratio (RR) 1.44 [1.06-1.96]). The absolute incidence of severe injuries (ie, time-loss >28 days) was twofold higher during WCS compared with SOS (RR 2.19 [1.21-3.95]). Most common injuries during the 2013-2015 seasons were knee followed by back (absolute incidences 56 [38-80] and 20 [10-36], respectively; RR 2.82 [1.42-5.61]), but this difference disappeared after 2015 (absolute incidences 25.6 [15.7-39.6] and 23.1 [13.7-36.5], respectively; RR 1.11 [0.59-2.10]). In summary, we found that 98 (59%) injuries occurred during WCS and 68 (41%) during SOS over 5 years. These results demonstrate the necessity to record injuries during the entire year to avoid a significant underestimation of the injury incidence. In addition, the current data showed an evolution of injury pattern over time and since previous reports, with back injuries being the main concern along knee joint injuries.     

Knee function among elite handball and football players 1‐6 years after anterior cruciate ligament injury

The aim of the study was to describe objective and self‐reported knee function for athletes who have returned to elite handball and football play after an ACL injury, comparing these to non‐injured players at the same level. A total of 414 handball and 444 football players completed baseline tests from 2007 through 2014, examining lower extremity strength, dynamic balance, knee laxity, and knee function (KOOS questionnaire). Measures were compared between injured and non‐injured legs and between injured legs and legs of controls. Eighty (9.3%) of the 858 players reported a previous ACL injury, 1‐6 years post‐injury (3.5±2.5 years), 49 handball (61.3%) and 31 football players (38.7%). We found no difference in strength or dynamic balance between previously ACL‐injured (N=80) and non‐injured players legs (N=1556). However, lower quadriceps (6.3%, 95% CI: 3.2‐9.2) and hamstrings muscle strength (6.1%, 95% CI: 3.3‐8.1) were observed in previously ACL‐injured legs compared to the non‐injured contralateral side (N=80). ACL‐injured knees displayed greater joint laxity than the contralateral knee (N=80, 17%, 95% CI: 8‐26) and healthy knees (N=1556, 23%, 95% CI: 14‐33). KOOS scores were significantly lower for injured knees compared to knees of non‐injured players. ACL‐injured players who have successfully returned to elite sport have comparable strength and balance measures as their non‐injured teammates. Subjective perception of knee function is strongly affected by injury history, with clinically relevant lower scores for the KOOS subscores Pain, Function, Sport, and Quality Of Life.     

关节镜下应用LARS人工韧带同时重建前、后交叉韧带

目的 探讨关节镜下应用LARS人工韧带重建前交叉韧带(ACL)、后交叉韧带(PCL)同时损伤的方法及疗效. 方法 关节镜下同时重建13例ACL、PCL损伤的患者,重建材料采用LARS人工韧带.术后随访12～36个月,采用国际膝关节文件编制委员会(IKDC)韧带标准评价表和Lysholm膝关节功能评分表评估患膝功能,通过KT-1000检查膝关节前后松弛度.结果 术后无膝关节感染发生;均无伸膝受限,屈膝活动度105°～125°,平均117°.术后随访时IKDC评分:A类10例(77%),B类3例(23%).屈膝25°位KT-1000检查:双侧膝关节前向松弛度差异＜2 mm 12例,3～5 mm 1例;屈膝70°位检查:＜2 mm 12例,2～4 mm 1例.术前Lysholm膝关节功能评分为(63.8 ±2.9)分(49～69分),终末随访时为(91.1±2.7)分(88～95分),差异有统计学意义(P＜0.01). 结论 关节镜下同时重建膝关节ACL、PCL是目前治疗ACL、PCL同时损伤的一种微创、安全、有效的手术方法,近期疗效佳.     

High risk of new knee injury in elite footballers with previous anterior cruciate ligament injury

Background

Anterior cruciate ligament (ACL) injury is a severe event for a footballer, but it is unclear if the knee injury rate is higher on returning to football after ACL injury.

Objective

To study the risk of knee injury in elite footballers with a history of ACL injury compared with those without.

Method

The Swedish male professional league (310 players) was studied during 2001. Players with a history of ACL injury at the study start were identified. Exposure to football and all time loss injuries during the season were recorded prospectively.

Results

Twenty four players (8%) had a history of 28 ACL injuries in 27 knees (one rerupture). These players had a higher incidence of new knee injury of any type than the players without ACL injury (mean (SD) 4.2 (3.7) v 1.0 (0.7) injuries per 1000 hours, p  =  0.02). The risk of suffering a knee overuse injury was significantly higher regardless of whether the player (relative risk 4.8, 95% confidence interval 2.0 to 11.2) or the knee (relative risk 7.9, 95% confidence interval 3.4 to 18.5) was used as the unit of analysis. No interactive effects of age or any other anthropometric data were seen.

Conclusion

The risk of new knee injury, especially overuse injury, was significantly increased on return to elite football after ACL injury regardless of whether the player or the knee was used as the unit of analysis.     

关节镜下重建膝关节新鲜与陈旧前交叉韧带训练伤疗效对比分析

目的比较部队官兵体能训练所致膝关节前交叉韧带(ACL)损伤手术时机对疗效的影响。方法关节镜下对平均病程(5±0.8)周27例新鲜组和平均病程(76±10.5)周19例陈旧组ACL损伤,均以半腱肌和股薄肌为替代物进行手术重建。结果按Lysholm评分,新鲜组和陈旧组ACL损伤的优良率分别为92.5%和78.9%,两组比较差异有显著统计学意义(P<0.01)。结论体能训练所致膝关节交叉韧带损伤早期关节镜手术重建的疗效优于晚期重建。     

后交叉韧带损伤的临床流行病学研究

目的:探讨后交叉韧带损伤的临床流行病学特点。方法:回顾我所1999年3月至2006年12月187例后交叉韧带损伤患者的临床资料,对性别和年龄分布、致伤运动项目分布、创伤因素、创伤机制、创伤类型、伤后就诊时间、不稳症状出现时间、后交叉韧带损伤程度等进行研究分析。结果:男性发病率(77.54%)高于女性(22.46%),35岁以内的年轻患者(60.96%)居多。创伤因素中以意外伤(66.84%)居多,其中交通事故伤最多。运动伤总体发生率为33.16%,其中足球项目占40.32%。创伤类型以单一后交叉韧带损伤为主(69.52%),联合韧带伤占30.48%。创伤机制中运动伤以屈曲外翻伤多见(42.62%),意外伤则以胫前伤为主(65.08%)。伤后就诊时间平均359.28天,伤后出现不稳时间平均271.62天。损伤部位主要为实质部撕裂(72.12%),后交叉韧带损伤存在前外束和后内束中一束断裂或两束不同部位同时断裂。结论:后交叉韧带损伤以意外伤居多,其中以交通伤为主。后交叉韧带损伤合并其它韧带损伤发生率也较高。运动损伤发生于多种运动项目中,以足球项目最多见,专业运动员发生率较低。后交叉韧带损伤患者多需接受后交叉韧带重建手术治疗。     

Isolated ACL versus multiple knee ligament injury: associations with patient characteristics,cartilage status,and meniscal tears identified during ACL reconstruction

Objectives: The objectives of this study were to determine (1) if patients undergoing reconstruction of an isolated anterior cruciate ligament (ACL) tear had different characteristics (age, gender, body mass index [BMI]) than patients undergoing ACL reconstruction (ACLR) with multiple knee ligament (MKL) tears and (2) whether there was a difference in prevalence of articular cartilage injury and meniscus tears between these two groups.

Methods: Patients undergoing primary ACLR between February 2005 and June 2013 were identified through an ACLR registry. Patients were grouped by whether they had an isolated ACL tear or an ACL tear associated with another knee ligament tear. The study cohort was analyzed to identify differences in patient characteristics and cartilage/meniscus injury patterns between the groups.

Results: Of the 21,377 ACLR cases enrolled in the registry during the study period, 2.5% (n = 549) had MKL tears. The MKL group had more males (73.2% vs. 62.8%, p < 0.001) than the isolated ACL group. The MKL group also had a higher percentage of patients with a BMI greater than 30 (31.1% vs. 22.7%, p = 0.0002). When adjusting for these variables, any articular cartilage injury was equal in the two groups (OR = 1.01, CI 0.82–1.25, p = 0.922), while medial femoral condyle injury was less common in the MKL group (OR = 0.73, CI = 0.56–0.07, p = 0.28). The likelihood of any meniscus tear was lower in the MKL group (OR = 0.56, CI = 0.47–0.67, p < 0.001) as was the likelihood of medial meniscus tears (OR = 0.53, CI = 0.44–0.65, p < 0.001).

Conclusions: When comparing patients with MKL tears versus isolated ACL tears at ACLR, there was a higher percentage of males and patients with BMI over 30 in the MKL group. Medial femoral condyle articular cartilage injury, any meniscus tear, and medial meniscus tears were less common in patients with MKL injury compared to patients with isolated ACL tears.     

Meniscal tears in the ACL-deficient knee: correlation between meniscal tears and the timing of ACL reconstruction

Despite the fact that anterior cruciate ligament reconstruction (ACLR) is a common procedure, no clear guideline regarding the timing of reconstruction has been established. We hypothesized that there is a point in post injury period, after which significant increase in meniscal tears occurs. The purpose of this study was to derive a guideline in order to reduce the rate of secondary meniscal tears in the ACL-deficient knee. A total of 451 patients were retrospectively studied and divided into six groups according to the time from injury to ACLR: (a) 105 patients had undergone ACLR within 1.5 months post injury, (b) 93 patients within 1.5–3 months, (c) 72 patients within fourth to sixth month, (d) 56 patients within seventh to twelfth month, (e) 45 patients within the second year and (f) 80 patients within the third to fifth year. The presence of meniscal tears was noted at the time of ACL reconstruction and then recorded and statistically analysed. Fifty-three (50.5%) patients from group a, 46 (49.5%) from group b, 39 (54.2%) from group c, 31 (68.9%) from group d, 28 (62.2%) from group e and 54 (67.5%) from group f had meniscal tear requiring treatment. The statistical analysis demonstrated that the earliest point of significantly higher incidence of meniscal tears was in patients undergoing ACLR more than 3 months post injury. Therefore, ACLR should be carried out within the first 3 months post injury in order to minimise the risk of secondary meniscal tears.     

A comparison of injuries in elite male and female football players: A five‐season prospective study

The aim was to compare the epidemiology of injuries between elite male and female football players from the same club. Injuries and individual exposure time in a male team and a female team, both playing in the Spanish first division, were prospectively recorded by the club's medical staff for five seasons (2010‐2015) following the FIFA consensus statement. Total, training, and match exposure hours per player‐season were 20% higher for men compared to women (P< .01). Total, training, and match injury incidence were 30%‐40% higher in men (P≤ .04) mainly due to a 4.82 (95% confidence interval [CI ] 2.30‐10.08) times higher incidence of contusions, as there were no differences in the incidence of muscle and joint/ligament injuries (P≥ .44). The total number of absence days was 21% larger in women owing to a 5.36 (95% CI 1.11‐25.79) times higher incidence of severe knee and ankle ligament injuries. Hamstring strains and pubalgia cases were 1.93 (95% CI 1.16‐3.20) and 11.10 (95% CI 1.48‐83.44) times more frequent in men, respectively; whereas quadriceps strains, anterior cruciate ligament ruptures, and ankle syndesmosis injuries were 2.25 (95% CI 1.22‐4.17), 4.59 (95% CI 0.93‐22.76), and 5.36 (95% CI 1.11‐25.79) times more common in women, respectively. In conclusion, prevention strategies should be tailored to the needs of male and female football players, with men more predisposed to hamstring strains and hip/groin injuries, and women to quadriceps strains and severe knee and ankle ligament injuries.     

Anterior Cruciate Ligament Reconstructions in Active-Duty Military Patients

ACL tears are common injuries sustained by men and women in the armed forces. The physical requirements of these service members make operative treatment the most common treatment option. The choices of graft, fixation, and surgical technique are decisions made by the military surgeon and his/her patient. A well-established system of community hospitals and larger referral centers staffed by well-trained surgeons allows for top-notch care of our soldiers, airmen, marines, and sailors with ACL injuries.     

Risk factors for acute and overuse sport injuries in Swedish children 11 to 15 years old: What about resistance training with weights?

To determine the 1‐year self‐reported incidence of overuse and traumatic sport injuries and risk factors for injuries in children participating in a summer sports camp representing seven different sports. 4363 children, 11 to 15 years old participating in a summer camp in seven different sports answered a questionnaire. Injury in this cross‐sectional study was defined as a sport‐related trauma or overload leading to pain and dysfunction preventing the person from participation in training or competition for at least 1 week. A number of risk factors for injury were investigated such as sex, age, number of hours spent on training in general, and on resistance training with weights. Nearly half [49%, 95% confidence interval (CI) 48–51%] of the participants had been injured as a result of participation in a sport during the preceding year, significantly more boys than girls (53%, 95% CI 50–55% vs 46%, 95% CI 43–48%; P < 0.001). Three factors contributed to increased incidence of sport injuries: age, sex, and resistance training with weights. Time spent on resistance training with weights was significantly associated with sport injuries in a logistic regression analysis. In children age 11 to 15 years, the risk of having a sport‐related injury increased with age and occurred more often in boys than in girls. Weight training was the only modifiable risk factor that contributed to a significant increase in the incidence of sport injuries.