anterior cruciate ligament (ACL) injuries

‘When will I be able to play again, Doc?’ is the first and most pressing question asked by nearly all athletes (and their parents/team mates/coaches) after anterior cruciate ligament (ACL) injury. Thanks to huge advances in surgery and rehabilitation techniques, most patients are able to return to their chosen sport within four to nine months.

But does this return to play – particularly in sports involving lots of pivoting movements - do more harm than good, by exposing athletes to an increased risk of reinjury and, ultimately, osteoarthritis? Should doctors not be questioning whether it is advisable for their patients to return to sport at all? That is the question posed by Norwegian researchers G Myklebust and R Bahr in a leading article in the British Journal of Sports Medicine (‘Return to play guidelines after anterior cruciate ligament surgery’, Br J Sports Med 2005; 39:127-121).

Myklebust and Bahr combed the scientific literature for follow-up studies after anterior cruciate ligament (ACL) injury, examining the rate of return to sport, reinjury risk and the prevalence of osteoarthritis (OA). They boiled down their search to 20 studies of patients treated either conservatively or with reconstructive surgery, who had been followed up for between 4 and 14 years after the initial injury.

After analysing all the data, their key findings were:

Return to play. Although the initial rate of return to sport is high (80%-plus, regardless of type of treatment), subsequent rates of retirement from sport are higher among the anterior cruciate ligament (ACL) injured population than among the uninjured. The only relevant study that used a control group found that 30% of injured elite soccer players were still active in the sport after three years, compared with 80% in an uninjured control population. ‘The reasons for this,’ the authors write, ‘may be that many of the athletes who return to sport experience significant knee problems, such as instability, reduced range of motion and/or pain.’
Reinjury rate after surgery. The few studies that have examined reinjury risk report re-rupture rates ranging from 2.3% to 13%, nearly all of them caused by pivoting moves during play. Returning to pivoting sport without anterior cruciate ligament (ACL) reconstruction was linked with a considerable risk of injury to other structures, particularly the menisci and cartilage. One study showed that 22% of non-operatively treated players who returned to sport underwent subsequent surgery for an injured meniscus, compared with 12% of operatively treated players.
Prevalence of OA. By 10 years after anterior cruciate ligament (ACL) injury about half of all patients display signs of osteoarthritis, suggesting that nearly all ACL-injured athletes will have OA after 15-20 years. The prevalence of OA does not seem to depend on whether or not reconstruction was performed. Thus, there is no evidence to suggest that ligament reconstruction prevents future OA.

A central question arising out of these findings is whether there is an increased risk of OA in athletes who return to sport, compared with those who retire. The researchers call for large prospective studies of athletes with anterior cruciate ligament (ACL) injuries to provide an answer to this question.

They conclude: ‘Most elite athletes are initially able to resume their sports career. However… the retirement rate may be higher among athletes with a previous anterior cruciate ligament (ACL) injury compared with healthy athletes. Furthermore, it is apparent that there is a significant risk of reinjury to the graft, as well as the menisci and cartilage, with continued sports participation. Finally, there are convincing data to show that nearly all patients will develop OA with time.

‘Thus is seems reasonable to question whether return to high-level pivoting sports really is in the athlete’s best interest – if long-term knee health is the primary concern.’

Effects of ankle support on performance

Does ankle stabilisation, designed to prevent injury, have the unlooked-for effect of inhibiting athletic performance? That is the question addressed by a new research study from the US (‘Effects of ankle support on lower-extremity functional performance: a meta-analysis’, Med Sci Sports Exerc vol 37, no 4, pp635- 641, 2005).

Studies in this area have drawn contradictory conclusions, so the researchers re-analysed the pooled data from 17 previous trials investigating the effects of different external ankle stability devices on one or more performance measures, in the hope of achieving a reliable answer.

‘The main purpose of prophylactic ankle support is to restrict frontal plane motion occurring at the subtalar joint,’ the researchers write. ‘However, movement in the sagittal plain is constrained as well, which may interfere in the execution of functional tasks.

‘Although these devices have been shown to be beneficial in the prevention of ankle injury, athletes will avoid wearing ankle supports that they perceive as hindering athletic performance. Therefore, it is important to determine whether external ankle supports substantially hinder an individual’s ability to carry out sport- specific tasks.’

All the studies in this meta-analysis were published between 1972 and 2002, using either recreationally active or competitive (but not elite) athletes. Each study looked at the effects of at least one of the three levels of ankle support (adhesive tape, lace-up and semi-rigid) on at least one of three performance measures (sprint time, agility time and vertical jump height), using a control group (without ankle support) for comparison purposes.

Main findings for the three chosen performance measures were as follows:

Sprint speed. Overall, the effects translated into an average 1% decrease in sprint speed across all ankle support conditions. The small negative performance effects were greatest with the lace-up style brace;
Agility speed. External ankle support had a marginal adverse impact on agility performance, with an overall reduction of 0.3%. There was a suggestion that the semi-rigid style of support had the greatest negative effects on this aspect of performance;
Vertical jump height. Overall, an average decrease in performance of about 1% was found, with adhesive tape demonstrating the greatest restriction to performance.

‘This study,’ the researchers write, ‘showed that the average effects of external ankle support on sprint, agility and vertical jump performance ranged from trivial to small in subjects who are not elite athletes.

‘It is likely, however, that the true effects of these ankle support conditions will be larger in some individuals. Moreover, it is reasonable to surmise that the effects observed in this investigation may have greater performance implications in the elite athlete.’

They conclude: ‘In the meantime, it is our opinion that the benefit in preventing injury outweighs the possibility of substantial but small impairment of performance when athletes use external ankle support.’

Effective treatment for groin pain

Osteitis pubis (painful inflammation of the pubic bone) is often a self-limiting condition in athletes, although surgery is sometimes required for persistent pain. Now a Finnish research team has found that a minimally invasive surgical technique using synthetic mesh to support the damaged area may hasten the healing of this injury (‘Successful treatment of osteitis pubis by using totally extraperitoneal endoscopic technique’, Int J Sports Med 2005;26:303-306).

The procedure was used on five elite- level male athletes with chronic groin pain from osteitis pubis between 1997 and 2002, with pain and return to sport evaluated one, six and 12 months afterwards. No complications were associated with surgery and all five athletes resumed their sporting activities one to two months later, with no tenderness or pain observed after one year.

The researchers conclude that this surgical technique is a safe and effective option when conservative treatment fails.

Isabel Walker is the editor of Peak Performance