ACL prehabilitation: what a 36-study systematic review found, and what it cannot show

A 2025 systematic review in Knee Surgery, Sports Traumatology, Arthroscopy gathered 36 studies covering 2,326 patients who underwent prehabilitation, meaning rehabilitation delivered before surgery, ahead of anterior cruciate ligament reconstruction (ACLR) ^[1]. The authors conclude that prehabilitation is a safe and effective intervention with short- to long-term benefits, although the data reported in the abstract support a narrower reading of that conclusion ^[1].

What was studied

The review had two stated aims: to describe current prehabilitation practices for ACLR and to assess the clinical outcomes and complication rates that follow them ^[1]. The authors searched EMBASE, MEDLINE, Cochrane and PubMed from inception to 1 November 2024 and included all studies that reported outcomes, complications or both after prehabilitation and ACLR ^[1]. Screening and data abstraction followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Revised Assessment of Multiple Systematic Reviews guidelines, and the authors graded the work as Level II evidence ^[1].

The abstract reports weighted averages of outcomes and percentages of complications across the included studies; it does not present a pooled statistical comparison between prehabilitation and standard care ^[1].

In whom

The included studies enrolled 2,326 patients who received prehabilitation and then underwent ACLR ^[1]. The abstract does not report patient age, sex, sport or activity level, time from injury to surgery, graft type, or the length and frequency of prehabilitation programmes, so readers cannot tell from the abstract alone how closely the pooled population resembles any particular patient ^[1].

What was found

Across studies, prehabilitation programmes emphasised resolution of impairments, restoration of range of motion (ROM) and neuromuscular exercise ^[1]. Weighted averages of all reported clinical outcomes met or exceeded patient acceptable symptom state (PASS) thresholds and return to sports (RTS) criteria; the abstract does not state which outcome instruments or threshold values were used ^[1]. These results describe how prehabilitation patients scored against fixed thresholds rather than how they compared with patients who did not receive prehabilitation ^[1].

No preoperative complications were reported after prehabilitation ^[1]. Major postoperative complications were reported at these rates ^[1]:

• Graft failure, 4.6% ^[1].
• Contralateral ACL rupture, 1.0% ^[1].
• Surgical site infection, 0.6% ^[1].
• Non-ACL ligament injury, 0.5% ^[1].
• Deep infection, 0.4% ^[1].
• Reoperation for hardware removal, 0.3% ^[1].
• Muscle rupture, patellar subluxation and patellar rupture, 0.1% each ^[1].

The authors state that these postoperative complication rates were similar to those of patients undergoing standard care, but the abstract does not give the comparator rates or a statistical test ^[1]. They also conclude that prehabilitation expedited postoperative recovery and that functional improvements were maintained up to 10 years after surgery ^[1]. The abstract does not report the number of studies, the designs or the effect sizes behind the recovery and 10-year statements ^[1].

Context from other prehabilitation research

In other surgical populations, prehabilitation has been tested in randomized controlled trials, in which participants are randomly assigned to an intervention or to standard care ^[2][3]. In the FRAILMar trial of 121 kidney transplant candidates, an 8-week, 24-session exercise programme improved exercise capacity by 12.8 watts (95% CI, 3.4 to 22.2; P = 0.008) compared with standard care among the 106 who completed it, with a short follow-up period noted as a limitation ^[2]. In the PRE-HIIT trial of 79 patients awaiting lung or esophageal cancer surgery, high-intensity interval training increased peak oxygen consumption relative to standard care, with a 6.6% between-group difference (P = 0.05) ^[3]. Those trials measured preoperative fitness in non-orthopaedic patients and do not speak directly to outcomes after ACLR ^[2][3].

AthleticsMD, in Columbia and Laurel/Fort Meade, Maryland, offers PREOOP surgical pre-optimization programmes and physical therapy; questions about prehabilitation before ACLR are best taken to a clinician ^{[AthleticsMD]}.

Limitations

• The review included all studies reporting outcomes or complications after prehabilitation and ACLR, and the abstract does not state how many were randomized trials, cohort studies or case series ^[1].
• Outcome results are weighted averages compared against PASS and RTS thresholds, which cannot establish that prehabilitation caused those outcomes ^[1].
• The safety comparison with standard care is stated in the conclusion without comparator figures in the abstract ^[1].
• The abstract does not report a risk-of-bias assessment or heterogeneity across studies ^[1].
• The authors call for further high-quality randomized controlled trials and large prospective cohort studies comparing prehabilitation with standard care, with specific exercise details and protocol progression reported ^[1].
• The long-term claim of benefit up to 10 years rests on data the abstract does not quantify ^[1].