Healing of acute anterior cruciate ligament rupture on MRI and outcomes following non-surgical management with the Cross Bracing Protocol.

OBJECTIVE: Investigate MRI evidence of anterior cruciate ligament (ACL) healing, patient-reported outcomes and knee laxity in patients with acute ACL rupture managed non-surgically with the Cross Bracing Protocol (CBP). METHODS: Eighty consecutive patients within 4 weeks of ACL rupture were managed with CBP (knee immobilisation at 90° flexion in brace for 4 weeks, followed by progressive increases in range-of-motion until brace removal at 12 weeks, and physiotherapist-supervised goal-oriented rehabilitation). MRIs (3 months and 6 months) were graded using the ACL OsteoArthritis Score (ACLOAS) by three radiologists. Mann-Whitney U tests compared Lysholm Scale and ACL quality of life (ACLQOL) scores evaluated at median (IQR) of 12 months (7-16 months) post-injury, and χ2 tests compared knee laxity (3-month Lachman's test and 6-month Pivot-shift test), and return-to-sport at 12 months between groups (ACLOAS grades 0-1 (continuous±thickened ligament and/or high intraligamentous signal) versus ACLOAS grades 2-3 (continuous but thinned/elongated or complete discontinuity)). RESULTS: Participants were aged 26±10 years at injury, 39% were female, 49% had concomitant meniscal injury. At 3 months, 90% (n=72) had evidence of ACL healing (ACLOAS grade 1: 50%; grade 2: 40%; grade 3: 10%). Participants with ACLOAS grade 1 reported better Lysholm Scale (median (IQR): 98 (94-100) vs 94 (85-100)) and ACLQOL (89 (76-96) vs 70 (64-82)) scores, compared with ACLOAS grades 2-3. More participants with ACLOAS grade 1 had normal 3-month knee laxity (100% vs 40%) and returned to pre-injury sport (92% vs 64%), compared with participants with an ACLOAS grades 2-3. Eleven patients (14%) re-injured their ACL. CONCLUSION: After management of acute ACL rupture with the CBP, 90% of patients had evidence of healing on 3-month MRI (continuity of the ACL). More ACL healing on 3-month MRI was associated with better outcomes. Longer-term follow-up and clinical trials are needed to inform clinical practice.

Sagittal patellar flexion angle measurement determines greater incidence of patella alta in patellar tendinopathy patients.

PURPOSE: The objective of this study was to compare patellar height and patella alta between a control cohort and patients with patellar tendinopathy by the sagittal patellar flexion angle (SPFA) measurement. METHODS: Magnetic resonance imaging (MRI) scans of the knee were obtained from a sports imaging facility and screened to select patients with anterior knee pain. This symptomatic group was divided into two patient cohorts: those with and without MRI features of patellar tendinopathy. Lateral knee radiographs were reviewed and SPFA, knee flexion angle and Insall-Salvati ratio (IS) were measured from the radiographs by two independent reviewers. RESULTS: A total of 99 patients consisting of 48 patellar tendinopathy patients and 51 control patients were included. There was a significantly higher mean patellar height (p = 0.002, d = 0.639) and a greater patella alta incidence in the patellar tendinopathy cohort (25.0%) compared to the controls (3.9%) (p = 0.022, d = 0.312). Insall-Salvati ratio measurements showed no difference in patella alta incidence between tendinopathy and control cohorts. There was excellent inter- and intra-observer reliability of SPFA measurements (ICC 0.99). CONCLUSION: This is the first study to demonstrate a greater incidence of patella alta in patellar tendinopathy patients compared to controls. A greater patella alta incidence amongst patellar tendinopathy patients as defined by SPFA was found to be clinically relevant, as it suggests these patients may comprise the recalcitrant patient subgroup who do not improve with current surgical intervention and may therefore benefit from a biomechanical surgical solution. LEVEL OF EVIDENCE: III.

MRI findings are associated with time to return to play in first class cricket fast bowlers with side strain in Australia and England.

OBJECTIVES: To investigate the reliability of reporting and relationship between MRI parameters at injury and time to return to play (RTP) in first class cricket fast bowlers with side strain in Australia and England. DESIGN: Cohort study. METHODS: Eighty MRI scans of side strain injuries to 57 fast bowlers were sourced. Ten scans were reported by three experienced radiologists to determine intra- and inter-rater reliability. The relationship between six MRI parameters (muscle injured, presence of a muscle tear, rib level of injury, presence of blood fluid products/haematoma, periosteal stripping, rib oedema) and time to RTP was investigated with 39 scans reported by a single radiologist with known intra-rater reliability. The association between parameters and time to RTP was analysed with an ordinal logistic regression model. RESULTS: Recovery time was prolonged with a mean of 39days (standard deviation: 14days) and 44% of bowlers requiring more than 6weeks to RTP. Reliability levels between parameters varied widely. The presence or absence of a muscle tear was the only MRI parameter associated with time to RTP. Players with a muscle tear were 8 times more likely to take more than 6weeks to RTP. The multifactorial model was predictive of recovery time in only 53% of this cohort, leaving 47% of total variance in time to RTP unexplained. CONCLUSIONS: The presence of a muscle tear was associated with time to RTP in cricket fast bowlers with side strain injury in first class cricket in Australia and England.

Efficacy of a platelet-rich plasma injection for the treatment of proximal hamstring tendinopathy: A pilot study.

OBJECTIVES: To determine the efficacy of an ultrasound-guided platelet-rich plasma (PRP) injection in the treatment of patients with proximal hamstring tendinopathy (PHT). DESIGN: Pilot prospective cohort study METHODS: Administration of a single PRP injection under ultrasound guidance to 29 patients with PHT confirmed on magnetic resonance imaging (MRI). Pain, function and sporting activity were measured via the Victorian Institute of Sport Assessment-Proximal Hamstring Tendons (VISA-H) questionnaire, administered before injection and at 8-weeks follow-up. RESULTS: The study sample consisted of 22 females and 7 males with a mean age of 45.2 years (95% CI 40.8-49.5). When comparing pre-injection VISA-H scores (mean: 43.90; 95% CI 37.77-50.03) with 8-week post-injection VISA-H scores (mean: 51.14; 95% CI 43.39-58.88) in the total sample of patients, no statistically significant difference was found (p=0.14). When performing separate analyses for patients with mild (n=9), moderate (n=16) or marked (n=4) PHT, no statistically significant difference was found in pre-and post-injection VISA-H scores for any of the groups (p=0.86, p=0.13, p=0.28 respectively). 69% of patients reported no change in their ability to undertake sport or other physical activity at 8-weeks follow-up. CONCLUSIONS: Patients with PHT receiving a PRP injection did not improve on clinical outcomes at 8-weeks follow-up.

Evaluation of Intrinsic Biomechanical Risk Factors in Patellar Tendinopathy: A Retrospective Radiographic Case-Control Series.

BACKGROUND: Patellar tendinopathy is an overuse condition often affecting athletes. It has been postulated that patellar tendinopathy is associated with patella alta; however, this and any other anatomic risk factors have not been identified. PURPOSE: To explore whether lever arm differences from radiographic measurements exist between patients with and without tendinopathy. This may provide surgeons with a simple radiographic means to identify patients at risk. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: Magnetic resonance imaging scans of the knee from a sports imaging facility were screened and reviewed to identify 2 groups of patients: those with and those without imaging signs of patellar tendinopathy. The lateral radiographs were reviewed and measurements made to determine (1) lever arm ratio, (2) moment arm ratio, (3) angle between the moment and line of pull of the patellar tendon, (4) patellar tendon pivot point angle, and (5) patellar height (alta). Measurements were obtained directly from radiographs. The images and measurements were reviewed by 2 experienced orthopaedic clinicians. RESULTS: A total of 105 patients were included in this study: 52 with patellar tendinopathy and 53 without patellar tendinopathy (controls). The mean age was similar between groups (23 years); females accounted for 8 of 52 patients with patellar tendinopathy and 24 of 53 patients without. The lever arm ratio in the group with patellar tendinopathy versus controls was 1.71 versus 1.01 (P = .01), with a moment arm difference of 1.00 versus 0.80 (P < .01), respectively. There was no difference detected between groups for patellar tendon angle, patellar tendon pivot point angle, knee flexion angle, or incidence of patella alta. No correlation was found with our measurements and the Insall-Salvati ratio. Statistical analysis was also performed according to sex, and a statistically significant difference between groups was found for differences in lever arm ratio and moment arm. CONCLUSION: The lever arm ratio and moment arm ratio from lateral radiographs were significantly different between patients with and without patellar tendinopathy. Further study is needed on the biomechanical implications of the pivot point and how altering it can affect stress within the patellar tendon, patellofemoral joint, and associated clinical outcomes.

A circumstellar disk associated with a massive protostellar object.

The formation process for stars with masses several times that of the Sun is still unclear. The two main theories are mergers of several low-mass young stellar objects, which requires a high stellar density, or mass accretion from circumstellar disks in the same way as low-mass stars are formed, accompanied by outflows during the process of gravitational infall. Although a number of disks have been discovered around low- and intermediate-mass young stellar objects, the presence of disks around massive young stellar objects is still uncertain and the mass of the disk system detected around one such object, M17, is disputed. Here we report near-infrared imaging polarimetry that reveals an outflow/disk system around the Becklin-Neugebauer protostellar object, which has a mass of at least seven solar masses (M(o)). This strongly supports the theory that stars with masses of at least 7M(o) form in the same way as lower mass stars.