The proximal hamstring avulsion clinical trial (PHACT)—a randomised controlled non-inferiority trial of operative versus non-operative treatment of proximal hamstrings avulsions: study protocol

Abstract

IntroductionThe treatment of proximal hamstring avulsions is controversial. While several trials have investigated the outcome for patients treated surgically, there is today no prospective trial comparing operative treatment with non-operative treatment. This protocol describes the design for the proximal hamstring avulsion clinical trial (PHACT)—the first randomised controlled trial of operative versus non-operative treatment for proximal hamstring avulsions.Methods and analysisPHACT is a multicentre randomised controlled trial conducted across Sweden, Norway and Finland. Eligible patients (60 participants/treatment arm) with a proximal hamstring avulsion of at least two of three tendons will be randomised to either operative or non-operative treatment. Participants allocated to surgery will undergo reinsertion of the tendons with suture anchors. The rehabilitation programme will be the same for both treatment groups. When patient or surgeon equipoise for treatment alternatives cannot be reached and randomisation therefore is not possible, patients will be invited to participate in a parallel observational non-randomised cohort. The primary outcome will be the patient-reported outcome measure Perth hamstring assessment tool at 24 months. Secondary outcomes include the Lower Extremity Functional Score, physical performance and muscle strength tests, patient satisfaction and MR imaging. Data analysis will be blinded and intention-to-treat analysis will be preformed.Ethics and disseminationEthical approval has been granted by the Ethical Committee of Uppsala University (DNR: 2017–170) and by the Norwegian ethical board (REC: 2017/1911). The study will be conducted in agreement with the Helsinki declaration. The findings will be disseminated in peer-reviewed publications.Trial registration numberNCT03311997

Predictive Factors Influencing Functional Results After Proximal Hamstring Tendon Avulsion Surgery: A Patient-Reported Outcome Study After 227 Operations From a Single Center

“…Previous studies have revealed noticeable ceiling effects in some non–injury-specific scores, leading to a possible overestimation and overly positive display of the results. 2 , 21 , 30 Thus, only a weak correlation between the hamstring injury–specific PHAT score and the LEFS, customized LEFS, Marx, and customized Marx scores was found, indicating that the PHAT score is perhaps the more accurate test score 2 , 3 , 5 – 7 and enhancing our findings.…”

“… 12 , 17 , 24 Regarding the retraction of the tendon on MRI, the decision for a surgical approach was made based on a previously proposed stump retraction benchmark of 2 cm by the Wood classification. 9 , 11 , 12 , 16 , 21 , 33 Patients with a tendon retraction of less than the named benchmark (Wood type 4) were informed and counseled for nonoperative treatment; they received surgical treatment only in cases of severe symptoms (eg, sciatic nerve irritations, large hematoma) or on their explicit wish. Cases with a tendon retraction of more than 2 cm (Wood type 5) were advised to undergo surgical refixation of the tendon.…”

“…3,13,17,29,30,32 These studies have, however, revealed inconsistent conclusions-to some extent debatably describing the timing of surgery to be of inferior relevance regarding surgical outcome results. 13,29,32 In any case, the current knowledge has been gathered from reviews, meta-analyses, 8,17 and studies whose conclusions are based on the investigation of comparably small cohorts 9,19,22,25 with univariate analyses, including a great variety of partially validated or non-injury-specific outcome scores, 1,2,[6][7][8]17,21,26,32 such as the Lower Extremity Functional Scale (LEFS) or the Marx activity score. 4,20 However, using outcome scores, especially validity and specificity, has recently been debated regarding their expressiveness if only "adjusted" to a type of injury instead of being injury specific.…”

Editorial Commentary: Proximal Hamstring Tendon Injuries: Is the Research Hamstrung by the Use of Poor Outcome Measures?

“…The first such trial of proximal hamstring avulsion injuries is currently recruiting patients to compare operative with nonoperative treatment. 21 It will be interesting to see what impact the results will have on current practice. Another option for collecting data on less common pathologies is using data registries.…”

London International Consensus and Delphi study on hamstring injuries part 2: operative management

“…With new standardised scoring systems such as the SHORE and PHAT tools being created, we hope to see higher level research on the best treatment for HSIs. One multicentre randomised controlled trial is currently recruiting patients to operative and non-operative treatment arms for proximal avulsion injuries 73. This will potentially improve our understanding on when to offer surgical repair along with the PHAROS, which is gathering prospective data on hamstring repair outcomes internationally.…”