There is more to the knee joint than just the quadriceps:A systematic review with meta-analysis and evidence gap map of hamstring strength,flexibility,and morphology in individuals with gradual-onset knee disorders

Background:Impairments in hamstring strength,flexibility,and morphology have been associated with altered knee biomechanics,pain,and function.Determining the presence of these impairments in individuals with gradual-onset knee disorders is important and may indicate targets for assessment and rehabilitation.This systematic review aimed to synthesize the literature to determine the presence of impairments in hamstring strength,flexibility,and morphology in individuals with gradual-onset knee disorders.Methods:Five databases(MEDLINE,Embase,CINAHL,SPORTDiscus,and Web of Science)were searched from inception to September 2022.Only studies comparing hamstring outcomes(e.g.,strength,flexibility,and/or morphology)between individuals with gradual-onset knee disorders and their unaffected limbs or pain-free controls were included.Meta-analyses for each knee disorder were performed.Outcome-level certainty was assessed using the Grading of Recommendations Assessment,Development,and Evaluation,and evidence gap maps were created.Results:Seventy-nine studies across 4 different gradual-onset knee disorders(i.e.,knee osteoarthritis(OA),patellofemoral pain(PFP),chondromalacia patellae,and patellar tendinopathy)were included.Individuals with knee OA presented with reduced hamstring strength compared to pain-free controls during isometric(standard mean difference(SMD)=-0.76,95%confidence interval(95%CI):-1.32 to-0.21)and concentric contractions(SMD=-0.97,95%CI:-1.49 to-0.45).Individuals with PFP presented with reduced hamstring strength compared to painfree controls during isometric(SMD=-0.48,95%CI:-0.82 to-0.14),concentric(SMD=-1.07,95%CI:-2.08 to-0.06),and eccentric contractions(SMD=-0.59,95%CI:-0.97 to-0.21).No differences were observed in individuals with patellar tendinopathy.Individuals with PFP presented with reduced hamstring flexibility when compared to pain-free controls(SMD=-0.76,95%CI:-1.15 to-0.36).Evidence gap maps identified insufficient evidence for chondromalacia patellae and hamstring morphology across all gradual-onset knee disorders.Conclusion:Our findings suggest that assessing and targeting impairments in hamstring strength and flexibility during rehabilitation may be recommended for individuals with knee OA or PFP.

Ultrasound and Doppler-Guided Surgery for the Treatment of Jumper’s Knee in Professional Rugby Players

Background: Jumper’s knee is relatively common among rugby players, and treatment of this condition is known to be difficult. Intratendinous revision surgery has shown poor results. New research on innervation patterns, and a new US+DP-guided treatment method targeting the regions with vessels and nerves outside the tendon has shown promising results in patients with Jumper’s knee. Material: This study includes 12 patellar tendons from 9 professional rugby players (mean age 26 years) with a long duration (range 12 - 72 months) of pain from the proximal patellar tendon. For 3 tendons there was previously intratendinous revision surgery with a poor result. Method: Treatment with Ultrasound (US) and Doppler (DP)-guided arthroscopic shaving + open scraping, followed by immediate weight bearing and gradually increased loading up to full loading after 6 - 8 weeks, was performed. Results: For 9 tendons there was a good clinical result, and all returned to full professional rugby within 4 - 6 months. The mean VISA score increased from 49 to 78 (p < 0.05). Follow-ups (range 10 - 30 months) show remaining good results. For 3 tendons, all have had previous intratendinous revision surgery, the clinical results were poor and they couldn’t return to rugby. Conclusions: The short-term results in this relatively small material indicate that US+DP-guided arthroscopic shaving + open scraping is a good treatment method for professional rugby players with chronic painful Jumper’s knee.