Evaluation of the hamstring muscle complex following acute injury

Objective To evaluate the imaging findings following acute hamstring injury.Design and patients We retrospectively reviewed the imaging findings of hamstring muscle complex (HMC) strain in 170 patients referred to our institution over a 3-year period. A total of 179 injuries to the HMC were demonstrated in 170 patients (154 male, 16 female, mean age 28.2 years). The mean duration of symptoms was 4.7 days (range 1–10 days). MR imaging was performed in 97 cases and sonography in 102 cases (both modalities were performed in 20 examinations). Attention was directed to the frequency of muscle involvement, the location of the injury within the muscle-tendon unit, the extent of the injury and discriminating avulsion from muscle injury.Results and conclusions Twenty-one patients had proximal tendon injury, with sixteen avulsions and five partial tears. Sixteen of these patients had surgical confirmation of hamstring avulsion from the ischial tuberosity (14 conjoint, 2 biceps femoris alone) and all were reliably diagnosed with MR imaging (16/16), but less so with sonography (7/12). Four distal tendon avulsions were also observed (three semitendinosus, one biceps femoris). With respect to muscle injury, the biceps femoris was most commonly injured (124/154). Semimembranosus was an uncommon muscle injury (21/154) and semitendinosus rare (9/154). Imaging can discriminate a hamstring tendon avulsion from musculotendinous strain and helps identify which patients necessitate surgical management as opposed to conservative treatment.     

Avulsion of the common hamstring tendon origin in an active duty airman

Hamstring injuries are common in active athletic populations, such as military service members. Ruptures of the hamstring origin from the ischial tuberosity are rare injuries and missed if not considered in the differential diagnosis of ischial pain. Unlike other hamstring injuries, complete hamstring avulsions must be treated surgically. Results of untreated hamstring avulsions are poor. The purpose of this article is to describe the case of an active duty airman who presented for an unrelated complaint and was discovered to have a 5-week-old hamstring avulsion. Surgical repair of the hamstring avulsion 6 weeks after injury yielded an excellent result and return to full duty. Hamstring avulsions recognized early by history and physical examination and diagnostic imaging permits early and effective treatment. Early surgical repair of the tendon to bone can result in return to full duty.     

Adolescent hamstring avulsions that simulate tumors

Hamstring injuries are common in athletes. Most of these injuries are diagnosed clinically and managed conservatively. Some patients, such as those with atypical clinical presentations or persistent pain, may be referred for imaging evaluation. In this subacute setting, studies obtained may have confusing features, and fractures may be mistaken for neoplasms. Hamstring avulsions, as seen on plain radiographs and conventional tomography, can have an aggressive appearance owing to callus and postfracture osteolysis. Although computed tomography is not usually necessary, it is very helpful in the subacute setting, identifying the healing avulsed apophysis. Familiarity with the appearance of ischial avulsions over time and with different modalities facilitates accurate characterization of hamstring injuries. We present our experience with six ischial avulsion fractures referred to us as tumors.     

Rupture of the conjoint tendon at the proximal musculotendinous junction of the biceps femoris long head: a case report

This case report describes a 20-year-old elite-level Australian Rules football player who suffered three unilateral hamstring injuries within a 2 month period. The first two episodes were managed conservatively. Magnetic resonance imaging following the third episode revealed full thickness disruption of the proximal musculotendinous junction of the biceps femoris long head and semitendinosus muscles and the common proximal (conjoint) tendon. The injury was subsequently surgically repaired. At 16 months following surgery, the player had successfully completed a full competitive season of elite-level Australian Rules football symptom free. Follow-up magnetic resonance imaging demonstrated the repaired tendon to be uniformly hypointense in keeping with reparative granulation tissue formation and restoration of normal muscle morphology. These findings are consistent with an intact repair. The case demonstrates that complete functional and radiological resolution is possible following surgical repair of significant hamstring musculotendinous junction tears.     

Practice patterns for the treatment of acute proximal hamstring ruptures

ABSTRACT

Objective: Proximal ischial hamstring avulsion injuries are relatively uncommon. As such, the management of these injuries is often highly variable. Consensus agreement is lacking for the indications for repair, along with the operative technique, and post-operative rehabilitation. The purpose of this study was to survey surgeons who treat proximal hamstring avulsion injuries to identify current trends in the management of this injury.

Methods: After IRB approval, a 46-question cross-sectional survey was distributed using a secure electronic survey portal. The survey sought to determine surgeon experience, diagnostic preferences, treatment patterns, surgical indications/technique, perceived patient outcomes, surgical complications, as well as post-operative management and rehab protocols. Surveys were completed electronically and anonymously, with invitations distributed to members of the American Orthopedic Society for Sports Medicine (AOSSM) and Arthroscopy Association of Canada (AAC).

Results: A total of 108 surgeons who manage proximal hamstring injuries completed the survey. Most respondents (77%) treat one to five of these injuries per year. MRI was the preferred imaging modality to confirm diagnosis. Despite 98% of respondents indicating that there was a role for surgical management of proximal hamstring avulsions, operative treatment was reportedly undertaken in only 50% of cases seen by each respondent. The top three reported surgical indications were: number of tendons involved (most important factor = 42%, second most = 26%, third most = 13%), amount of tendon retraction (28%, 41%, 16%), and patient activity level (16%, 18%, 24%).

Conclusion: Based on the practice patterns of the surgeons who completed the survey, there is continued disparity in the management of proximal hamstring avulsions. A lack of agreement exists with regards to surgical indications, operative technique, and post-operative protocols. Most striking is the rate of non-operative treatment and perceived rate of poor outcomes within this cohort. Future research should focus on objective evaluation of non-operative management, and additional variables involved in surgical treatment and post-operative rehabilitation.     

Characteristics of acute groin injuries in the adductor muscles: A detailed MRI study in athletes

Acute adductor injuries account for the majority of acute groin injuries; however, little is known about specific injury characteristics, which could be important for the understanding of etiology and management of these injuries. The study aim was to describe acute adductor injuries in athletes using magnetic resonance imaging (MRI ). Male athletes with acute groin pain and an MRI confirmed acute adductor muscle injury were prospectively included. MRI was performed within 7 days of injury using a standardized protocol and a reliable assessment approach. 156 athletes presented with acute groin pain of which 71 athletes were included, median age 27 years (range 18‐37). There were 46 isolated muscle injuries and 25 athletes with multiple adductor injuries. In total, 111 acute adductor muscle injuries were recorded; 62 adductor longus, 18 adductor brevis, 17 pectineus, 9 obturator externus, 4 gracilis, and 1 adductor magnus injury. Adductor longus injuries occurred at three main injury locations; proximal insertion (26%), intramuscular musculo‐tendinous junction (MTJ ) of the proximal tendon (26%) and the MTJ of the distal tendon (37%). Intramuscular tendon injury was seen in one case. At the proximal insertion, 12 of 16 injuries were complete avulsions. This study shows that acute adductor injuries generally occur in isolation from other muscle groups. Adductor longus is the most frequently injured muscle in isolation and in combination with other adductor muscle injuries. Three characteristic adductor longus injury locations were observed on MRI , with avulsion injuries accounting for three‐quarters of injuries at the proximal insertion, and intramuscular tendon injury was uncommon.     

Apophysitis of the ischial tuberosity mimicking a neoplasm on magnetic resonance imaging

We present multimodality imaging features of an ischial tuberosity apophysitis in a 13-year-old boy who was an active baseball pitcher. Roentgenography of the pelvis and computed tomography showed mild irregularity in the inferior margin of the left ischial tuberosity. T1-weighted MRI showed a wide area with low signal intensity in the left ischial body; T2-weighted fat-suppression images showed areas with markedly high signal intensity in the ischial apophysis and body and the surrounding periosteum; contrast-enhanced T1-weighted fat-suppression MRI showed that the ischial body, surrounding periosteum, and origin of the hamstring muscles strongly enhanced; technetium-99m scintigraphic scans showed increased isotope uptake in the entire ischial body. Histological specimens obtained from the bone showed increased osteoblastic activity, edema, and proliferation of benign spindle cells and small vessels in the bone marrow spaces. In the present case, because MR imaging demonstrated extensive signal abnormalities involving the apophysis, periosteum, and intramedullary portion of bone, a neoplasm could not be excluded, and a biopsy was undertaken.     

MR imaging of rectus femoris origin injuries

Objective To describe the MR imaging findings of acute and chronic rectus femoris origin (RFO) injuries.Materials and methods A retrospective review of pelvic and hip MR imaging procedures was performed over a 4-year period for detection of cases with injuries to the RFO. Subjects were classified as having either acute or chronic symptoms. MR imaging studies, radiographs, CT scans, radiology reports, medical records, and operative notes were reviewed. Imaging analysis was directed to assess injuries affecting the direct and indirect heads of the RFO. Concurrent osseous, cartilaginous and musculotendinous injuries were tabulated.Results The incidence of RFO injuries on MR imaging was 0.5% (17/3160). With the exception of one case of anterior inferior iliac spine apophysis avulsion and partial tear of the direct head of RFO, all subjects had indirect head of RFO injuries (acute injury 8/9, chronic injury 8/8). Partial tear of the direct head of RFO was less frequently seen (acute injury 3/9, chronic injury 2/8). Partial tears of the conjoint tendon were least frequent (acute 1/9, chronic 2/8). No full-thickness tears of the RFO were noted. Associated labral tears were seen in only one case, with no other concomitant abnormality of the articular cartilage or surrounding soft tissues. All RFO injuries were treated non-operatively.Conclusion Injuries of the RFO are uncommon on MR examinations of pelvis/hips and may occur in a sequence progressing from indirect head injury to involvement of direct head and conjoint tendon in more severe cases.     

MR imaging of the distribution and location of acute hamstring injuries in athletes

OBJECTIVE: Although hamstring injuries are common in athletes, the distribution and location of such injuries have not been well defined. We used MR imaging to determine the frequency of injury by muscle, involvement of one or more muscles, and location of injuries within the musculotendinous unit. SUBJECTS AND METHODS: We performed MR imaging on 15 consecutive college athletes with clinically diagnosed acute hamstring injuries. A hamstring injury was diagnosed and located on MR imaging by identifying high signal intensity within the muscle on T2-weighted images. RESULTS: We found that 10 athletes had injuries of a single muscle with six injuries of the biceps femoris, three of the semitendinosus, and one of the semimembranosus. In an additional five athletes, we found primary injuries of the biceps femoris and secondary injuries of the semitendinosus. The injuries occurred in diverse locations within the muscles including five injuries at the proximal musculotendinous junction, two at the distal musculotendinous junction, four within the proximal half of the muscle belly, and four in the distal half. All eight intramuscular injuries were located at the musculotendinous junction within the muscle. CONCLUSION: The biceps femoris is the most commonly injured hamstring muscle and the semitendinosus is the second most commonly injured. Although hamstring injuries often involve one muscle injured proximally, multiple muscles were involved in 33% of athletes (5/15) and the injuries were distal in 40% of athletes (6/15). All intramuscular injuries occurred at the musculotendinous junction, either at the ends of the muscle or within the muscle belly.     

Iliopsoas injury: an MRI study of patterns and prevalence correlated with clinical findings

OBJECTIVES: The objective was to retrospectively determine the prevalence and patterns of iliopsoas injuries based on consecutive MRI examinations, correlated with clinical findings. MATERIALS AND METHODS: From 4,862 consecutive MRI examinations of the hips and pelvis, 32 patients with 33 iliopsoas injuries were identified and graded as muscle strain, partial tendon tear, and complete tendon tears. These patients' medical records were reviewed to determine age, gender, and cause of symptoms. RESULTS: The prevalence of iliopsoas tendon and myotendinous injuries was 0.66% (95% CI: 0.44-0.89). There were 18 females and 14 males whose ages ranged from 7 to 95 years (mean, 54 years). The most frequent presenting symptom was hip pain and the most frequent clinical diagnosis, an occult fracture. The most common injuries in patients under 65 years (16 patients) were muscle strains and partial tendon tears, most often due to an athletic injury. The most common injury in patients 65 years and older (16 patients) was a complete tear (8 patients, all females), 2 of which were spontaneous in origin. CONCLUSIONS: Each grade of iliopsoas injury occurred with similar frequency. The more advanced the age of the patient, the more severe the injury. Non-athletic injuries predominated in patients 65 years and older; athletic injuries were the most common cause of iliopsoas injury in patients under 65 years.     

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.     

Treatment of proximal hamstring ruptures - a systematic review

Proximal hamstring ruptures are increasingly treated surgically, despite little high-level supporting evidence. We sought to determine whether there are differences in clinical outcome after surgical vs. non-surgical treatment of proximal hamstring tendinous avulsions/ruptures and acute vs. chronic surgical repair of tendinous avulsions. Multiple medical databases were searched for Level I-IV evidence. 18 studies were included. 298 subjects (300 proximal hamstring injuries) were analyzed with mean age of 39.7 years. 286 injuries were managed with surgical repair vs. 14 non-operative. 95 surgical cases were performed within 4 weeks of the injury (acute), while 191 were performed beyond 4 weeks (chronic). 292 injuries were tendinous avulsions while 8 were bony tuberosity avulsions. Surgical repair resulted in significantly (p < 0.05) better subjective outcomes, greater rate of return to pre-injury level of sport, and greater strength/endurance than non-surgical management. Similarly, acute surgical repair had significantly better patient satisfaction, subjective outcomes, pain relief, strength/endurance, and higher rate of return to pre-injury level of sport than chronic repair (p < 0.001) with reduced risk of complications and re-rupture (p < 0.05). Chronic surgical repair also improves outcomes, strength and endurance, and return-to-sport, but not as well as acute repair. Non-operative treatment results in reduced patient satisfaction, with significantly lower rates of return to pre-injury level of sport and reduced hamstring muscle strength.     

Proximal hamstring morphology and morphometry in men: an anatomic and MRI investigation

The proximal musculo‐tendinous junction (MTJ) is a common site of hamstring strain injury but the anatomy of this region is not well defined. A morphometric analysis of the proximal MTJs of biceps femoris long head (BFlh), semitendinosus (ST), and semimembranosus (SM) was undertaken from dissection of 10 thighs from five male cadavers and magnetic resonance imaging of 20 thighs of 10 active young men. The length, volume, and cross‐sectional area of the proximal tendon, MTJ and muscle belly, and muscle‐tendon interface area were calculated. In both groups, MTJs were reconstructed three‐dimensionally. The proximal tendons and MTJs were expansive, particularly within SM and BFlh. Morphology varied between muscles although length measurements within individual muscles were similar in cadavers and young men. Semimembranosus had the longest proximal tendon (cadavers: mean 33.6 ± 2.0 cm; young men: mean 31.7 ± 1.6 cm) and MTJ (>20 cm in both groups) and the greatest muscle‐tendon interface area, followed by BFlh and ST. Mean muscle belly volumes were more than three times greater in young men than elderly male cadavers (P < 0.001). These unique morphometric data contribute to a better understanding of hamstring anatomy, an important factor in the pathogenesis of hamstring strain injury.     

Surgical treatment of partial tears of the proximal origin of the hamstring muscles

Background

Hamstring injuries are common especially in athletes. Partial and complete tears of the proximal origin may cause pain and functional loss.

Objective

To evaluate the results of surgical treatment for partial proximal hamstring tears.

Methods

Between 1994 and 2005, 47 athletes (48 cases, 1 bilateral) with partial proximal hamstring tears were operated on. The cases were retrospectively analysed. Before surgery, 42 of the patients had undergone conservative treatment with unsatisfactory results, whereas in five patients the operation was performed within four weeks of the injury.

Results

The mean length of the follow up was 36 months (range 6–72). The result of the operation was rated excellent in 33 cases, good in nine, fair in four, and poor in two. Forty one patients were able to return to their former level of sport after an average of five months (range 1–12).

Conclusion

In most cases, excellent or good results can be expected after surgical repair of partial proximal hamstring tears even after conservative treatment has failed.     

Total proximal tendon avulsion of the rectus femoris muscle

Total proximal avulsions of the quadriceps femoris muscle group are rare injuries. Between the years 2001 and 2004 five patients with a total proximal avulsion of the tendon of the rectus femoris muscle were treated surgically in Mehiläinen Hospital in Turku, Finland. The median age of the patients was 21 years (range, 19–27) and the patients were all men. There were four soccer players and one hurdler. In all cases an avulsion of the proximal tendon of the rectus femoris muscle was confirmed by MRI. All of the patients were operated on and the delay from the injury to surgery ranged from 18 to 102 days. The result of the surgical treatment was rated good in all cases. All of the patients were able to return to their pre‐injury level of activity 5–10 months after surgery. The median follow‐up time was 20 months (range, 9–38). Surgical treatment of a total proximal avulsion of the tendon of the rectus femoris muscle seems to result in return to the pre‐injury activity level in most cases.     

Displaced avulsion of the ischial apophysis: a hamstring injury requiring internal fixation

A case is reported of an adolescent sprinter who was chronically disabled by pain after non-operative management for an acute hamstring injury. He had sustained an avulsion fracture of the ischial apophysis with displacement of 2.5 cm. Avulsion fractures of the ischial apophysis with displacement of 2 cm or more are unusual, but they frequently result in a symptomatic non-union, and early diagnosis, open reduction, and internal fixation is to be encouraged.


     

Injuries of the pectoralis major muscle: evaluation with MR imaging

PURPOSE: To demonstrate that magnetic resonance (MR) imaging allows evaluation of injuries of the pectoralis major muscle. MATERIALS AND METHODS: Fifteen men underwent MR imaging after injury of the pectoralis major muscle. Most of the patients (nine of 15) were injured while lifting weights, notably bench-pressing. The injuries were evaluated for abnormal morphology and signal intensity, specifically the site of injury, degree of tearing, and amount of tendon retraction. RESULTS: Six injuries occurred at the musculotendinous junction, and five were treated conservatively; eight of the nine cases of distal tendon avulsion were treated with primary surgical repair. The MR imaging findings were confirmed in the nine cases treated surgically. Complete tears (three of 15) were less common than partial tears (12 of 15). The sternal and clavicular heads were torn in 10 patients, only the clavicular head was torn in two patients, and only the sternal head was torn in three patients. Acute tears (10 of 15) demonstrated hemorrhage and edema, whereas chronic tears (five of 15) demonstrated fibrosis and scarring. There was a variable amount of tendon retraction. CONCLUSION: MR imaging allows accurate evaluation of injuries of the pectoralis major muscle and enables identification of patients who would benefit from surgical repair.     

Acute first-time hamstring strains during high-speed running: a longitudinal study including clinical and magnetic resonance imaging findings

BACKGROUND: Hamstring muscle strain is one of the most common injuries in sports. Still, knowledge is limited about the progression of clinical and magnetic resonance imaging characteristics and their association with recovery time in athletes. HYPOTHESIS: Knowing the anatomical location and extent of an acute first-time hamstring strain in athletes is critical for the prognosis of recovery time. STUDY DESIGN: Case series (prognosis); Level of evidence, 2. METHODS: Eighteen elite sprinters with acute first-time hamstring strains were prospectively included in the study. All subjects were examined, clinically and with magnetic resonance imaging, on 4 occasions after injury: at day 2 to 4, 10, 21, and 42. The clinical follow-up period was 2 years. RESULTS: All sprinters were injured during competitive sprinting, and the primary injuries were all located in the long head of the biceps femoris muscle. There was an association between the time to return to pre-injury level (median, 16; range, 6-50 weeks) and the extent of the injury, as indicated by the magnetic resonance imaging parameters. Involvement of the proximal free tendon, as estimated by MRI, and proximity to the ischial tuberosity, as estimated both by palpation and magnetic resonance imaging, were associated with longer time to return to pre-injury level. CONCLUSION: Careful palpation during the first 3 weeks after injury and magnetic resonance imaging investigation performed during the first 6 weeks after injury provide valuable information that can be used to predict the time to return to pre-injury level of performance in elite sprinting.