Affiliations: [a] Physiotherapy Department, University Hospital
Limerick, Limerick, Ireland | [b] Department of Clinical Therapies, University of
Limerick, Limerick, Ireland | [c] Department of Orthopaedic Surgery, University Hospital
Limerick, Limerick, Ireland | [d] Physiotherapy Department, Stellenbosch University,
Cape Town, South Africa
Abstract: BACKGROUND: The effect of hamstring tendon grafting
during anterior cruciate ligament reconstruction (ACLR) on residual hamstring
muscle strength remains unclear. OBJECTIVES: To identify if hamstring muscle strength deficits exist after ACLR using the ipsilateral
semitendinosus and gracilis tendons (STG) in absolute and relative terms, and
ascertain if pre-operative strength influences post-operative strength
outcomes. METHODS: A search was performed using five databases;
MEDLINE, SPORTSdiscus, Cinahl, AMED and Cochrane. Original articles that
reported both absolute and relative hamstring muscle strength on isokinetic
testing after ACLR with STG grafts were evaluated, selected and critically
appraised. RESULTS: Eleven studies that met the inclusion criteria
were included in the review. Hamstring peak torque (PT) deficits in the
reconstructed leg compared to the contralateral side ranged from 10–19% and
6.4–12.6% at six and 12~months, respectively. Minimal deficits were
reported at five to six year follow up. For absolute strength values the mean
PT identified in absolute terms was low at 96 Nm at 60°/s (Range
77–121.8 Nm) with just one study normalising PT to body weight (PTBW). Only
three of the included studies reported both pre- and post-operative results
with two studies identifying similar reductions in PT of 8.6–9% in the
operated limb from pre-operative to six months. CONCLUSION: Deficits in hamstring strength were found to exist up to one year post-operatively but
appear to resolve by five to six years. It is recommended that future studies
report PTBW to allow for better interpretation of results to allow for
comparisons against normative data. More research is needed to examine the
influence of pre-operative hamstring muscle strength on post-operative results.
