Early versus delayed lengthening exercises for acute hamstring injury in male athletes: a randomised controlled clinical trial.

BACKGROUND: To evaluate the efficacy of early versus delayed introduction of lengthening (ie, eccentric strengthening) exercises in addition to an established rehabilitation programme on return to sport duration for acute hamstring injuries in a randomised controlled superiority trial. METHODS: 90 male participants (age: 18-36 years, median 26 years) with an MRI-confirmed acute hamstring injury were randomised into an early lengthening (at day 1 of rehabilitation) group or a delayed lengthening (after being able to run at 70% of maximal speed) group. Both groups received an established rehabilitation programme. The primary outcome was time to return to sport (ie, time from injury to full unrestricted training and/or match play). The secondary outcome was reinjury rate within 12 months after return to sport. Other outcomes at return to sport included the Askling H-test, hamstring strength, clinical examination and readiness questions. RESULTS: The return to sport in the early lengthening group was 23 (IQR 16-35) days and 33 (IQR 23-40) days in the delayed lengthening group. For return to sport (in days), the adjusted HR for the early lengthening group compared with the delayed lengthening group was 0.95 (95% CI 0.56 to 1.60, p=0.84). There was no significant difference between groups for reinjury rates within 2 months (OR=0.94, 95% CI 0.18 to 5.0, p=0.94), from 2 to 6 months (OR=2.00, 95% CI 0.17 to 23.3, p=0.58), and 6 to 12 months (OR=0.57, 95% CI 0.05 to 6.6, p=0.66). CONCLUSION: Accelerating the introduction of lengthening exercises in the rehabilitation of hamstring injury in male athletes did not improve the time to return to sport nor the risk of reinjury.

Proximal hamstring tendon avulsions: comparable clinical outcomes of operative and non-operative treatment at 1-year follow-up using a shared decision-making model.

OBJECTIVE: To prospectively evaluate 1-year clinical and radiological outcomes after operative and non-operative treatment of proximal hamstring tendon avulsions. METHODS: Patients with an MRI-confirmed proximal hamstring tendon avulsion were included. Operative or non-operative treatment was selected by a shared decision-making process. The primary outcome was the Perth Hamstring Assessment Tool (PHAT) score. Secondary outcome scores were Proximal Hamstring Injury Questionnaire, EQ-5D-3L, Tegner Activity Scale, return to sports, hamstring flexibility, isometric hamstring strength and MRI findings including proximal continuity. RESULTS: Twenty-six operative and 33 non-operative patients with a median age of 51 (IQR: 37-57) and 49 (IQR: 45-56) years were included. Median time between injury and initial visit was 12 (IQR 6-19) days for operative and 21 (IQR 12-48) days for non-operative patients (p=0.004). Baseline PHAT scores were significantly lower in the operative group (32±16 vs 45±17, p=0.003). There was no difference in mean PHAT score between groups at 1 year follow-up (80±19 vs 80±17, p=0.97). Mean PHAT score improved by 47 (95% CI 39 to 55, p<0.001) after operative and 34 (95% CI 27 to 41, p<0.001) after non-operative treatment. There were no relevant differences in secondary clinical outcome measures. Proximal continuity on MRI was present in 20 (95%, 1 recurrence) operative and 14 (52%, no recurrences) non-operative patients (p=0.008). CONCLUSION: In a shared decision-making model of care, both operative and non-operative treatment of proximal hamstring tendon avulsions resulted in comparable clinical outcome at 1-year follow-up. Operative patients had lower pretreatment PHAT scores but improved substantially to reach comparable PHAT scores as non-operative patients. We recommend using this shared decision model of care until evidence-based indications in favour of either treatment option are available from high-level clinical trials.

Good Interrater Reliability for Standardized MRI Assessment of Tendon Discontinuity and Tendon Retraction in Acute Proximal Full-Thickness Hamstring Tendon Injury.

BACKGROUND: Proximal full-thickness free hamstring tendon injury (ie, tendon avulsion or rupture) is a severe injury. Treatment decision making relies on clinical factors and magnetic resonance imaging (MRI) variables; it specifically relies on which tendons are injured as well as the extent of tendon retraction. According to a worldwide evaluation of current practice, discontinuity of both proximal tendons and retraction of >2 cm are used as surgical indications. However, both the diagnosis and the use of MRI variables in decision making may be fraught with uncertainty in clinical practice. A reliable standardized MRI assessment is required. PURPOSE: To propose an MRI assessment for acute proximal full-thickness free hamstring tendon injury and to evaluate its interater reliability. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: We included 40 MRI scans of patients with acute (≤4 weeks of injury) proximal full-thickness free hamstring tendon injury. Three musculoskeletal radiologists assessed proximal full-thickness free hamstring tendon discontinuity using the novel "dropped ice cream sign" and tendon retraction (in mm). Quantification of tendon retraction (in mm) was performed using 2 different methods: (1) a direct (ie, shortest distance between the center of the hamstring origin and the tendon stump) method and (2) a combined craniocaudal/mediolateral measurement method. Absolute and relative interrater reliability were calculated. RESULTS: We found an almost perfect interrater agreement (kappa = 0.87) for assessment of full-thickness tendon discontinuity using the dropped ice cream sign. Interrater agreement for the direct and craniocaudal retraction measurements was good for both the conjoint (intraclass correlation coefficient [ICC], 0.88 and 0.83) and the semimembranosus tendons (ICC, 0.81 and 0.79). The mediolateral retraction measurement yielded only moderate to poor reliability for the conjoint (ICC, 0.53) and semimembranosus tendons (ICC, 0.41). CONCLUSION: The standardized MRI assessment to identify proximal hamstring tendon discontinuity and quantify tendon retraction is reliable. We recommend using the novel dropped ice cream sign and the direct retraction measurement in clinical practice and research.

Reliability of MRI in Acute Full-thickness Proximal Hamstring Tendon Avulsion in Clinical Practice.

In clinically suspected acute full-thickness proximal hamstring tendon avulsions, MRI is the gold standard for evaluating the extent of the injury. MRI variables such as full-thickness free tendon discontinuity, extent of tendon retraction (>20 mm), and continuity of the sacrotuberous ligament with the conjoint tendon (STL-CT) are used in treatment decision-making. The objective was to assess the intra- and inter-rater reliability of these relevant MRI variables after acute full-thickness proximal hamstring tendon avulsion. Three musculoskeletal radiologists assessed MRIs of 40 patients with an acute full-thickness proximal hamstring tendon avulsion. MRI variables included assessment of free tendon discontinuity and continuity of the STL-CT and extent of tendon retraction. Absolute and relative intra- and inter-rater reliability were calculated. Intra- and inter-rater reliability for the assessment of tendon discontinuity was substantial (Kappa [ĸ]=0.78;0.77). For the retraction measurement of the conjoint and semimembranosus tendons, intra-rater reliability was moderate and poor (Intraclass correlation coefficient (ICC)=0.74;0.45), inter-rater reliability was moderate (ICC=0.73;0.57). Intra- and inter-rater reliability of the STL-CT continuity assessment was substantial and fair (ĸ=0.74;0.31). In conclusion, MRI assessment for full-thickness free tendon discontinuity is reliable. However, assessment of extent of tendon retraction and STL-CT continuity is not reliable enough to guide the treatment decision-making process.

Assessment of Isometric Knee Flexor Strength Using Hand-Held Dynamometry in High-Level Rugby Players Is Intertester Reliable.

OBJECTIVE: To assess intertester reliability of isometric knee flexor strength testing in high-level rugby players with testers of different physical capacity and different methods of dynamometer fixation. DESIGN: Reliability study. PATIENTS: Thirty noninjured high-level (Tegner Activity Score ≥9) rugby players, free from hamstring injury in the previous 2 months. ASSESSMENT: Isometric knee flexor strength (in N) in prone 0/15 degrees (hip/knee flexion) and supine 90/90 degrees position. Tests were performed by 1 female and 2 male testers whose upper-body strength was measured with a 6-repetition maximum bench press test. The prone 0/15 degrees measurement was performed with manual and external belt fixation of the dynamometer. MAIN OUTCOME MEASURES: Absolute and relative intertester reliability were calculated using intraclass correlation coefficient (ICC) and minimal detectable change. Paired t-tests were used to identify systematic measurement error between testers and to test for a difference in recorded knee flexor strength between methods of dynamometer fixation. METHODS: Isometric knee flexor strength was measured in prone 0/15 degrees (hip/knee flexion) and supine 90/90 degrees position. RESULTS: Good intertester reliability was found for all pairwise comparisons (ICC 0.80-0.87). MDCs (as percentage of mean strength) ranged from 15.2% to 25.4%. For tester couples where systematic error was identified, Bland-Altman plots and Pearson correlation coefficients demonstrated no statistically significant correlation between mean knee flexor strength and between-tester difference. There was no significant difference in isometric knee flexor strength between manual and belt fixation of the dynamometer. CONCLUSIONS: In strong high-level rugby players, hand-held dynamometry for isometric knee flexor strength assessment in prone 0/15 degrees and supine 90/90 degrees position is intertester reliable.

Satisfactory clinical outcome of operative and non-operative treatment of avulsion fracture of the hamstring origin with treatment selection based on extent of displacement: a systematic review.

PURPOSE: To compare outcome of operative and non-operative treatment of avulsion fractures of the hamstring origin, with minor (< 1.5 cm) and major (≥ 1.5 cm) displacement, and early (≤ 4 weeks) and delayed (> 4 weeks) surgery. METHODS: A systematic literature search was performed using PubMed, Cochrane, Embase, CINAHL and SPORTDiscus. A quality assessment was performed using the Physiotherapy Evidence Database (PEDro) scale. RESULTS: Eight studies with 90 patients (mean age: 16 years) were included. All studies had low methodological quality (PEDro score ≤ 5). Operative treatment yielded a return to preinjury activity rate (RTPA) of 87% (95% CI: 68-95), return to sports (RTS) rate of 100% (95% CI: 82-100), Harris hip score (HHS) of 99 (range 96-100) and a University of California Los Angeles activity scale (UCLA) score of 100%. Non-operative treatment yielded a RTPA rate of 100% (95% CI:68-100), RTS rate of 86% (95% CI: 69-94), HHS score of 99 (range 96-100), and non-union rate of 18% (95% CI: 9-34). All patients with minor displacement were treated non-operatively (RTPA: 100% [95% CI: 21-100], RTS: 100% [95% CI: 51-100]). For major displacement, operative treatment led to RTPA and RTS rates of 86% (95% CI: 65-95) and 100% (95% CI: 84-100), and 0% (0/1, 95% CI: 0-79) and 100% (95% CI: 51-100) for non-operative treatment. Early surgery yielded RTPA and RTS rates of 100% (95% CI: 34-100 & 57-100) compared to 100 (95% CI: 72-100) and 90% (95% CI: 60-98) for delayed repair. CONCLUSION: All included studies have high risk of bias. There is only low level of evidence with a limited number of included patients to compare outcome of operative and non-operative treatment. Overall outcome was satisfactory. There is a treatment selection phenomenon based on displacement, with acceptable outcome in both groups. There is insufficient data to draw conclusions regarding timing of surgery. LEVEL OF EVIDENCE: IV.

Accuracy of manual and automatic placement of an anatomical coordinate system for the full or partial radius in 3D space.

Accurate placement of a coordinate system on the radius is important to quantitatively report 3D surgical planning parameters or joint kinematics using 4D imaging techniques. In clinical practice, the scanned length of the radial shaft varies among scanning protocols and scientific studies. The error in positioning a radial coordinate system using a partially scanned radius is unknown. This study investigates whether the imaged length of the radius significantly affects the positioning of the coordinate system. For different lengths of the radius, the error of positioning a coordinate system was determined when placed automatically or manually. A total of 85 healthy radii were systematically shortened until 10% of the distal radius remained. Coordinate systems were placed automatically and manually at each shortening step. A linear mixed model was used to associate the positioning error with the length of the radial shaft. The accuracy and precision of radial coordinate system placement were compared between automatic and manual placement. For automatic placement of the radial coordinate system, an increasing positioning error was associated with an increased shortening of the radius (P = < 0.001). Automatic placement is superior to manual placement; however, if less than 20% of the radial shaft length remains, manual placement is more accurate.

Abduction in Proximal Hamstring Tendon Avulsion Injury Mechanism: A Report on 3 Athletes.

Proximal hamstring tendon avulsions are typically sustained during forced hip hyperflexion combined with knee extension. We present 3 cases of athletes with a proximal hamstring tendon avulsion caused by an alternative injury mechanism that also involves a considerable hip abduction component (flexion-abduction injury mechanism). All cases had at least one concurrent injury of the medial thigh muscles, either on the ipsilateral or contralateral side. The 2 elite athletes with this injury mechanism returned to sport at preinjury level relatively quickly. A history of the flexion-abduction mechanism should raise suspicion of a hamstring tendon avulsion with concomitant injury of the medial thigh muscles. The magnetic resonance imaging (MRI) protocol should include both legs, and any concurrent injury may need to be addressed as well. In future studies, it would be interesting to investigate whether injury mechanism holds prognostic value in proximal hamstring tendon avulsions.

[A woman with a painful elbow]. / Een vrouw met een pijnlijke elleboog.

A 27-year-old woman presented to the Emergency Department with a painful right elbow after falling off a road bike. X-ray examination ruled out an elbow fracture, but showed a radiolucency in the radial tuberosity. MRI demonstrated normal bone marrow, which indicated that the radiolucency was in fact a radial tuberosity pseudolesion.

Intramuscular tendon injury is not associated with an increased hamstring reinjury rate within 12 months after return to play.

BACKGROUND: Acute hamstring injury that includes intramuscular tendon injury has been suggested to be associated with increased reinjury risk. These observations were based on a relatively small number of retrospectively analysed cases. OBJECTIVE: To determine whether intramuscular tendon injury is associated with higher reinjury rates in acute hamstring injury. METHODS: MRIs of 165 athletes with an acute hamstring injury were obtained within 5 days of injury. Treatment consisted of a standardised criteria-based rehabilitation programme. Standardised MRI parameters and intramuscular tendon injury, the latter subdivided into tendon disruption and waviness, were scored. We prospectively recorded reinjuries, defined as acute onset of posterior thigh pain in the same leg within 12 months after return to play. RESULTS: Participants were predominantly football players (72%). Sixty-four of 165 (39%) participants had an index injury with intramuscular hamstring tendon disruption, and waviness was present in 37 (22%). In total, there were 32 (19%) reinjuries. There was no significant difference (HR: 1.05, 95% CI 0.52 to 2.12, P=0.898) in reinjury rate between index injuries with intramuscular tendon disruption (n=13, 20%) and without tendon disruption (n=19, 20%). There was no significant difference in reinjury rate (X²(1)=0.031, P=0.861) between index injuries with presence of waviness (n=7, 19%) and without presence of waviness (n=25, 20%). CONCLUSION: In athletes with an acute hamstring injury, intramuscular tendon injury was not associated with an increased reinjury rate within 12 months after return to play.

Intramuscular tendon involvement on MRI has limited value for predicting time to return to play following acute hamstring injury.

BACKGROUND: Hamstring injury with intramuscular tendon involvement is regarded as a serious injury with a delay in return to play (RTP) of more than 50 days and reinjury rates up to 63%. However, this reputation is based on retrospective case series with high risk of bias. OBJECTIVE: Determine whether intramuscular tendon involvement is associated with delayed RTP and elevated rates of reinjury. METHODS: MRI of male athletes with an acute hamstring injury was obtained within 5 days of injury. Evaluation included standardised MRI scoring and scoring of intramuscular tendon involvement. Time to RTP and reinjury rate were prospectively recorded. RESULTS: Out of 70 included participants, intramuscular tendon disruption was present in 29 (41.4%) injuries. Injuries without intramuscular tendon disruption had a mean time to RTP of 22.2±7.4 days. Injuries with <50%, 50%-99% and 100% disruption of tendon cross-sectional area had a mean time to RTP of 24.0±9.7, 25.3±8.6 and 31.6±10.9 days, respectively. Injuries with full-thickness disruption took longer to RTP compared with injuries without disruption (p=0.025). Longitudinal intramuscular tendon disruption was not significantly associated with time to RTP. Waviness was present in 17 (24.3%) injuries. Mean time to RTP for injuries without and with waviness was 22.6±7.5 and 30.2±10.8 days (p=0.014). There were 11 (15.7%) reinjuries within 12 months, five (17.2%) in the group with intramuscular tendon disruption and six (14.6%) in the group without intramuscular tendon disruption. CONCLUSION: Time to RTP for injuries with full-thickness disruption of the intramuscular tendon and waviness is significantly longer (by slightly more than 1 week) compared with injuries without intramuscular tendon involvement. However, due to the considerable overlap in time to RTP between groups with and without intramuscular tendon involvement, its clinical significance for the individual athlete is limited.

Outcome After Surgical Repair of Proximal Hamstring Avulsions: A Systematic Review.

BACKGROUND: At the present time, no systematic review, including a quality assessment, has been published about the outcome after proximal hamstring avulsion repair. PURPOSE: To determine the outcome after surgical repair of proximal hamstring avulsions, to compare the outcome after acute (≤4 weeks) and delayed repairs (>4 weeks), and to compare the outcome after different surgical techniques. STUDY DESIGN: Systematic review and best-evidence synthesis. METHODS: PubMed, CINAHL, SPORTdiscus, Cochrane library, EMBASE, and Web of Science were searched (up to December 2013) for eligible studies. Two authors screened the search results separately, while quality assessment was performed by 2 authors independently using the Physiotherapy Evidence Database (PEDro) scale. A best-evidence synthesis was subsequently used. RESULTS: Thirteen studies (387 participants) were included in this review. There were no studies with control groups of nonoperatively treated proximal hamstring avulsions. All studies had a low methodological quality. After surgical repair of proximal hamstring avulsion, 76% to 100% returned to sports, 55% to 100% returned to preinjury activity level, and 88% to 100% were satisfied with surgery. Mean hamstring strength varied between reporting studies (78%-101%), and hamstring endurance and flexibility were fully restored compared with the unaffected side. Symptoms of residual pain were reported by 8% to 61%, and reported risk of major complications was low (3% rerupture rate). No to minimal difference in outcome was found between acute and delayed repair in terms of return to sports, patient satisfaction, hamstring strength, and pain. Achilles allograft reconstruction and primary repair with suture anchors led to comparable results. CONCLUSION: The quality of studies included is low. Surgical repair of proximal hamstring avulsions appears to result in a subjective highly satisfying outcome. However, decreased strength, residual pain, and decreased activity level were reported by a relevant number of patients. Minimal to no differences in outcome of acute and delayed repairs were found. Limited evidence suggests that an Achilles allograft reconstruction yields results comparable with primary repair in delayed cases where primary repair is not possible. High-level studies are required to confirm these findings.