In 2005 the Cochrane Collaboration analysed all randomised and quasi-randomised trials comparing surgery with conservative treatment of ACL rupture in adult.1 They concluded that there was no evidence to determine whether current surgical techniques or conservative management was best treatment for ACL injuries. They recommended that good quality randomised trials were required to remedy this situation. In 2009 this paper was updated with no changes to its conclusions.

In his reply to my previous letter Mr Hooper promotes ACL reconstruction, claiming it "improves knee function in greater than 90%, with the majority of patients returning to aggressive sporting and working activities, especially those activities that involve twisting or rapid change of direction." Neither of the papers he quotes support his opinion. The first paper is a non-randomised retrospective study promoting ACL reconstruction in the non-athlete.2 The second paper is an assessment of 70 randomised controlled trials in regard to surgical technique and rehabilitation of ACL injuries.3 The authors concluded that none of the papers were high quality and they stressed the need for further studies.

I found five papers on the natural history of an ACL rupture. The most rigorous of these studies involved 50 patients with complete ACL ruptures.4 The MRI findings were that 21 (42%) had a normal ACL and 20 (40%) had a partial repair at 3 months. Mr Hooper claims that full thickness midsubstance tears (of the ACL) rarely heal. He is wrong. Nor do the papers he cite support his opinion. The first paper explores the effect of anterior cruciate ligament trauma and bracing on knee proprioception.5 The other follows 49 patients who had ongoing problems with their knees following ACL ruptures.6

Mr Hooper justifies ACL reconstruction by stating there is no evidence that it is responsible for the development of long-term osteoarthritis. He misses the point of my letter. The onus is on the surgeon to prove that ACL reconstruction doesn't cause long-term osteoarthritis and that study hasn’t been done. He also states "Instability is the commonest indication for ACL reconstruction" without supporting evidence. In my clinical experience instability has never been the indication for an ACL repair, but rather the patient has an ill-defined fear of future problems with the joint if they don't have surgery.

Mr Hooper claims my concerns regarding ACL reconstructions are inappropriate and misinformed. How so? The papers he cites to support his opinion are irrelevant to his claims. His “Best Practice” is based on an ACC document written in 2002 that has been superseded twice by the Cochrane Collaboration.

ACL reconstruction surgery has no randomised controlled trial (RCT) support.

The anterior cruciate ligament (ACL) is not a redundant structure. Rupture causes anterolateral rotary instability which can be disabling, even in routine activities of daily living. Some patients can cope with life changes to accommodate for this but most continue to experience episodes of instability. The overwhelming literature and clinical experience supports reconstruction in these patients to improve knee stability.

ACL reconstruction became popular in the late 1970s when the instability pattern was recognised and procedures that produced less morbidity were advanced. This was popularised because ACL ruptures rarely healed. Today the treatment of ACL rupture is being directed towards methods of manipulating the environment to enable ACL healing. The millions of dollars directed towards the genetic engineering to achieve this tissue modification would not be spent if the ACL healed.

Constructing a RCT at this stage in the evolution of ACL treatment would be impossible. Firstly, gaining ethical approval would be unlikely and secondly, recruitment into the non-operative group in a young active cohort would be difficult at best.

It is true that there are few RCTs to support reconstruction but this is not uncommon in surgical practise where a procedure has produced such a profound improvement in function. Few would disagree that total hip replacement has been a successful operation but there have never been any RCTs to prove this.

Does this mean that hip replacement is not a proven procedure?