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 Table of Contents  
ORIGINAL ARTICLE
Year : 2022  |  Volume : 24  |  Issue : 2  |  Page : 118-123

Pattern of anterior cruciate ligament injuries in armed forces


1 Department of Orthopaedics, INHS Asvini, Mumbai, Maharashtra, India
2 Department of Medicine, INHS Asvini, Mumbai, Maharashtra, India
3 Department of Orthopaedics, Base Hospital, Delhi Cantt, India
4 Brig Med 4 Corp, c/o 99 APO, India
5 Physiotherapy Department, CH (WC), Chandimandir, Panchkula, Haryana, India
6 Department of Anesthesia, AFMC, Pune, Maharashtra, India

Date of Submission12-Mar-2021
Date of Decision17-May-2021
Date of Acceptance30-May-2021
Date of Web Publication10-Aug-2022

Correspondence Address:
Lt Col (Dr) Munish Sood
Department of Orthopaedics, INHS Asvini, Mumbai, Maharashtra
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/jmms.jmms_38_21

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  Abstract 


Background: Anterior cruciate ligament (ACL) injuries are the commonly seen and potentially devastating injuries in sportsperson and high-demand professionals like military personals. The return to the preinjury status even after the successful ACL reconstruction surgery is not assured. The aim of this study was to assess the pattern and profile of ACL injuries seen in military personnel. Materials and Methods: Five hundred and twenty-four patients who were operated at our center with ACL reconstruction and were meeting the inclusion criteria were included in this study. Patients were evaluated with detailed history and clinical and radiological examination. Results: Five hundred and twenty-four patients were evaluated at a mean of 7.86 months. The mean age was 29.64 years (range: 20–46 years). Five hundred and twenty patients were male and four were female. The mode of injury was sporting activity in 244 (46.6%), military training-related activity in 180 (34.3%), and other activities in 100 (19.1%). Football and basketball were the most common sporting activities in which ACL injuries were sustained, while landing injuries during 9-feet ditch activity (n = 109) were the single most common activity in which ACL injuries were sustained. An isolated ACL tear in 235 patients was the most common type of injury seen, while the meniscus injuries (medial and lateral meniscus) in 149 (28.4%) and 115 (21.9%) patients, respectively, were the most commonly seen associated injuries. Conclusions: ACL injuries are a common occurrence in armed forces. Injury during sports and landing injuries in 9-feet ditch are the common modes by which patients sustained ACL injuries.

Keywords: Anterior cruciate ligament, lateral meniscus, medial meniscus


How to cite this article:
Sood M, Sachdeva J, Ghai A, Sud A, Chauhan M, Singh S. Pattern of anterior cruciate ligament injuries in armed forces. J Mar Med Soc 2022;24:118-23

How to cite this URL:
Sood M, Sachdeva J, Ghai A, Sud A, Chauhan M, Singh S. Pattern of anterior cruciate ligament injuries in armed forces. J Mar Med Soc [serial online] 2022 [cited 2023 Apr 1];24:118-23. Available from: https://www.marinemedicalsociety.in/text.asp?2022/24/2/118/353655




  Introduction Top


Anterior cruciate ligament (ACL) injuries are commonly seen in athletes and high-demand professionals.[1],[2],[3],[4],[5] ACL deficiency leads to instability of the knee joint which can be a career-ending event for the high-demand professional and additional financial burden to the state.[6] Further, in the military population, it can be the cause of rejection or invalidment after going through the stress and strains of difficult training.[7] These injuries can also cause disabling posttraumatic arthritis at the long term which is not dependent upon treatment given to the individual after the injury.[8]

There are several risk factors associated with ACL injuries, which can be divided into nonmodifiable and modifiable factors.[9],[10] The nonmodifiable factors commonly known as intrinsic risk factors are female gender, genetic factor (familial predisposition), anatomical factors (slope of tibia knee and hyperlaxity of joints), hormonal factors (female hormonal concentration variability during the menstrual cycle), neurocognitive function (slower reaction and processing speed), and previous injury to the knee or the lower extremity.[10] The modifiable factors or extrinsic risks include weather, level and type of activity, type of playing surface/footwear, and type of equipment used.[10] The understanding of these risk factors can help athletes and training staff in the prevention of ACL injuries.[5]

The incidence and prevalence of ACL injury have been reported in various studies from Asian and Western population.[1],[11],[12],[13] However, there are very few studies reporting the incidence of ACL injury in military populations.[14] The ACL injury rate in military personnel was found to be more than ten times the normal population in the United States.[14] ACL injuries are increasingly common in athletes and the armed forces and constitute one of the major operative sports medicine workloads.[15] However, there is no study from the Indian Armed Forces regarding the nature and pattern of ACL injuries. This study aims at presenting the pattern and profile of ACL injuries recorded in serving soldiers.


  Materials and Methods Top


The current observational study was carried out over a period of 4 years from 2015 to 2019 at one of the tertiary care military hospitals. The study was approved by the institutional ethical committee. The inclusion criteria were all serving soldiers presenting with an ACL tear and willing to participate in the study. The exclusion criteria were patients who were operated earlier for any knee pathology on any side or reinjury to the already reconstructed ACL.

The patients were assessed as per the departmental standard protocol for knee injuries. Acute injuries of knee were initially treated conservatively with rest, immobilization and symptomatic therapy. Further, clinical evaluation was performed after period of convalescence .i.e when the knee is quiescent. The clinical evaluation was done. While in case of chronic knee injuries with instability, clinical evaluation was performed during first visit only. The history regarding instability or giving away of the knee was obtained. Any history of associated locking, pain, and difficulty in ambulation was also noted. The protocol also included demographic descriptions such as age, gender, side involved, and mechanism causing ACL injuries. The time between injury and first evaluation at our center was also noted. The history was obtained regarding the mode of injury (like sports-related/physical training/twisting injury/fall or some accident) and type of injury (contact/noncontact injuries). The patients were examined clinically for instability using tests such as pivot-shift test, anterior drawer test, Lachman test, and stress test. Menisci were evaluated using joint line tenderness and McMurray test. The ACL injuries along with associated meniscus or ligament injuries were also noted. Magnetic resonance imaging of the knee joint was performed in all the patients. All patients have been operated arthroscopically for ACL tear using semitendinosus and gracilis graft. Furthermore, any additional injuries found intraoperatively were also noted and addressed at the time of surgery.

Statistical analysis

The categorical data were presented as n (%). Proportions were compared using Chi-square or Fisher's exact test whichever applicable. The continuous data were given as mean ± standard deviation and range or median and interquartile range as appropriate. All statistical tests were two-sided and performed at a significance level of α =0.05. The analysis was conducted using IBM SPSS statistics software (IBM SPSS, version 22.0).

Sample size calculation

The sample size was estimated based upon the total strength of armed forces.[16] The sample size required to perform this study was 385 subjects which were calculated at 95% confidence level. The margin of error was taken as 5%. For possible dropouts and to increase the power of the study, it was decided to include more patients.


  Results Top


Five hundred and twenty-four serving soldiers with ACL injuries were studied in the present study. Thirty-four patients were excluded as they were not fulfilling the inclusion criteria. The average age of the study population was 29.64 years (range: 18–46 years). Five hundred and twenty patients were male and only four were female. The left knee was involved in 283 (54.0%) patients, while the right knee was involved in 241 (46%) patients. These patients were evaluated at a mean of 7.86 months (range: 1–48 months) from the date of injury at our institute.

The mode of injury was sporting activities in 46.6% (n = 244), military training-related activity in 34.3% (n = 180), and other activities such as fall, twisting injuries, and roadside accidents in 19.1% (n = 100) of the cohort.

Out of 244 patients who sustained the injury in sports, 76 patients sustained while playing football, 68 in basketball, 53 in volleyball, 16 in kabaddi, 14 in handball, while the rest 17 sustained the injury in other games (such as wrestling, cricket, and javelin throw) [Table 1]. Out of 180 patients who sustained the injury in military training, 109 (60.6%) sustained the landing injury in 9-feet ditch activity which is a part of battle physical efficiency test (BPET), 54 (30%) sustained fall/twisting injury while running or 5-m shuttle during BPET/physical proficiency test, and 17 (9.4%) sustained injuring during rappelling/obstacle training [Table 1]. 31.5% (n = 165) of the injuries were contact injuries, while the noncontact injuries were seen in 68.5% (n = 359) of the patients.
Table 1: Mode of injury in patients

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Isolated ACL injuries (n = 235) were the most common injury seen. Medial meniscus was the most common structure injured along with ACL tear and it was seen in 149 (28.4%) patients while the lateral meniscus injuries were seen in 115 (21.9%) patients [Table 2]. Collateral ligament injuries of the medial and lateral ligaments were seen in seven (1.3%) and ten (1.9%) patients, respectively. Posterior cruciate and posterior-lateral corner injuries were found in 13 (2.5%) patients each. Sixty-seven osteochondral injuries of various types were also seen. These injuries occurred in various combinations. However, the most common type of injury sustained was an isolated ACL tear followed by ACL with the medial meniscus tear. We also tried to find any correlation of the various injuries which were associated with ACL tear with the mode of injury (sports activity/military training/others) using Chi-square test [Table 2]. The lateral meniscus injuries associated with ACL tear were significantly higher in patients with training-related injuries (P = 0.016).
Table 2: Injuries associated with anterior cruciate ligament tear

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  Discussion Top


ACL injuries can be devastating, career-ending injuries in athletes and military personnel. In the early 1970, ACL injuries were considered as the cause of ex-athlete in the career of any sportsperson.[17] However, with the advent of newer surgical skills and rehabilitation strategies, the return to sports is possible at short-term follow-up.[18],[19] However, the rate of reinjuries and premature retirement is still higher in patients with ACL injury than healthy individuals.[17] Furthermore, in our scenario, these injuries are an economical burden to person as well as the state.[6]

ACL injuries are much more prevalent in military personnel as compared to the general population.[14] As environmental factors such as strenuous physical training, repeated stress activities, and sports-related activities seen in military personnel are the additional contributing factor to ACL injuries.[14] Halford et al.[7] documented that in the British Armed Forces, recruits who had been operated for ACL tear before enrolling with the army had a higher number of premature discharges. ACL injuries were evaluated and operated in large numbers in the various service hospitals of the Indian Armed Forces. However, the data regarding the pattern and profile of these injuries are lacking. The main objective of the present study was to evaluate demographic profile (age, gender, etc.), side involved, mode, and mechanism of sustaining these ACL injuries in serving soldiers.

The present observational study was conducted on a cohort of 524 patients. The mean age of the patients was approximately 30 years (range: 18–46 years), which is significantly higher than reported in various studies of athletes and the sporting population.[20],[21],[22] But, similar to the studies of the military population [Table 3]. The side involved (right or left) is similar to the various other published studies.[3],[20] The results of our studies such as study period, mean age, and gender are comparable to the various other studies from the military population [Table 3].
Table 3: Comparison of literature

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ACL injuries were seen in association with other ligaments and meniscus injuries in approximately 56% of the patients. Medial meniscus injuries were the most common and seen in 28% of the patients, followed by lateral meniscus injuries seen in 22% of the patients. These findings of our study are comparable to other studies.[1],[23] An association of posterior cruciate ligament, medial collateral ligament, and lateral collateral ligament injuries was relatively rare. The cartilaginous injuries were seen in approximately 13% of the patients. Chondral injuries seen were also comparable to other studies.[23] It was found that lateral meniscus injuries were found to be associated more with patients who sustained the injury during military training as compared to sports or other activities [Table 2] (P = 0.016).

As reported in the literature, noncontact injuries were also common in the present study,[20],[24] which were seen in 68.5% of the patients while the rest were contact injuries. Further, sports-related injuries were the most common and seen in 244 (46.6%) patients, followed by military training-related injuries in 180 (34.3%) patients. Football and basketball were the most common sports in which these injuries were sustained. Various other studies have also published similar findings.[3],[14] However, one of the findings which differ from various other studies, is the prevalence of landing-related injuries (in 9-feet ditch activity). These landing-related injuries were the most common cause and seen in 20.8% of the total patients. In our search on PubMed and Google Scholar, we could not find the presence of landing-related injuries at this rate in any military-related studies.[3],[14] Furthermore, training-related injuries were seen in a lesser number of personnel (5%–14%) in various studies[3],[7],[14] [Table 3]. The landing activity is a part of training, in which the individual has to jump over the ditch on the uneven surface sand or sandbag at the end of the ditch. Further, this landing is commonly done on one leg with hip and knee in extension which leads to adduction and internal rotation at the hip and abduction and external rotation at the knee. However, the described way of landing is on both feet with the knee slightly bent. Furthermore, these activities are generally performed either at the beginning of the training or after the end of 5 km run.

Although biomechanism causing noncontact ACL injuries is a matter of debate, various studies support complex multiplanner loading of the knee, i.e., loading in the sagittal, transverse, and frontal plane as the cause of noncontact injuries.[24],[25] The explanation for the higher number of landing injuries in training which are also noncontact injuries in our study, could be sudden deceleration at the time of landing with the knee close to extension or slightly bend as described [Figure 1]a and [Figure 1]b.[24],[25] Furthermore, valgus collapse with the knee joint in extension (between 0° and 30°) with the abduction and external rotation at the knee while the foot is planted during a deceleration maneuver, has been documented as a cause of noncontact or landing injuries.[24],[25] According to Hewett et al.,[26] knee landing in abduction/valgus is a risk factor for noncontact ACL injury. The reduction of knee abduction angles has been advocated as a training strategy to lower the chances of ACL injury.[27]
Figure 1: Landing position (a) single-leg landing in slight flexion of the hip and knee causing valgus at knee and stress to the anterior cruciate ligament (b) on both legs in slight flexion, internal rotation, and adduction of hip at hip and knee in flexion, internal rotation, and abduction leading to the anterior cruciate ligament stress. (c and d) Correct posture of landing with flexion, external rotation, and abduction of hip and knee in flexion, shoulder-width apart, and facing forward

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As a preventive strategy, landing in extension or slight flexion (between 0° and 30°) should be avoided, and it should be replaced with landing in flexion, abduction, and external rotation of the hip and knee. Landing activities should be performed on both the feet with hip and knee in flexion of more than 45° and feet aligned with the body or externally rotated and knee should be shoulder-width apart. This position should be held for at least 3 s with minimal body movements [Figure 1]c and [Figure 1]d.[23],[28] Further, it has also been noticed that most of the time, sandbags are placed in the takeoff and landing area of the 9-feet ditch which make the activity area hard and uneven which can also be a contributory factor for these injuries. Various studies have reported the type of surface as an environmental factor contributing to ACL injuries.[30] Therefore, soft and flat landing surfaces can be used as an alternative to prevent landing-related ACL injuries.[31] In addition, it has been noticed that ACL injuries are more common if performed without warm-up or in a fatigued state, i.e., toward the end of the training session.[31] Therefore, landing activities should be performed at the start of the training session after proper warm-up specific to landing activities.[31],[32],[36]

One of the limitations of this study is that the number of exposures before the ACL injuries occurred in this group of patients was not calculated. Furthermore, patients were evaluated at a mean of 7.86 months from the time of injury. The delayed presentation of these patients can be a risk factor for reinjuries or additional injuries.


  Conclusions Top


ACL tear and associated injuries are commonly seen in the Indian Armed Forces. Medial and lateral meniscus injuries are the common association seen with ACL injuries. Noncontact injuries are relatively more common in our study. The most common mode of sustaining these injuries are various sporting activities and military training-related activities. The landing-related injuries were the most common injuries seen in the military training in our study. The strategies such as soft and flat landing surface, proper warm-up, improved agility, and modification in landing position should be employed to prevent noncontact injuries like landing injuries.[28],[29],[32]

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
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