Pre-surgery / pre-op / pre-rehabilitation
The rehabilitation process prior to the ACL surgery is termed “preoperative rehabilitation” or just pre-op and has been suggested to physically and mentally prepare patients for surgery and post operative rehabilitation. After the injury, the athlete can be subclassified into: coper (athlete that can resume previous recreational activities without reconstruction), non-coper (athlete that requires ACLR because of recurrent give-away episodes in activities of daily living) and adaptors (athletes that can manage without reconstruction by modifying/lowering their activity level). Thoma et al. (2019) showed that almost half (45%) of initial potential noncopers became potential copers after a 5 week pre-op neuromuscular strength training program, while only 13% of initial potential copers became noncopers after the training program. The program consisted of progressive strengthening, plyometric, and neuromuscular exercises (Eitzen, 2010) which showed that quadriceps strength limb symmetry with a deficit below 20% is a significant predictor of knee function two years after an ACL injury.
Three systematic reviews have been performed on the effect of prehabilitation. Carter et al. 2020, performed their review based on three RCTs with 122 ACLR participants, of which 116 (95%) were male. Giesche et al. 2020, performed a systematic review based on six trials where there were two cohort studies, two controlled trials and two randomized controlled trials including a total of 5131 participants. Finally, Alshewaiver et al. 2015, performed a systematic review including eight studies, investigating a total of 451 persons of which 71% were males. A clear limitation of this body of evidence is the small study sample sizes which are dominated by males. The generalisability of these results is relatively limited due to study design, population and setting. Alshewaiver et al. 2015, concluded despite the range of pre-operative approaches used in the review that pre-operative physiotherapy rehabilitation is effective for improving the outcomes of treatment following anterior cruciate ligament injury and clinicians are to be aware of these findings as pre-operative rehabilitation may be of value to patients who undergo ACLR.
However, both Carter, 2020 and Giesche et al. 2020 concluded that evidence supporting the use of prehabilitation remains limited. However, Giesche et al. 2020 concluded that prehabilitation may reduce the decline of postoperative neuromuscular performance of the lower limb and improve self-reported knee function and RTS success. In contrast, Alshewaiver et al. 2015 found that pre-operative rehabilitation is effective for these patients.
Despite some positive implications, the majority of the orthopaedic surgeons seems to consider prehabilitation less important in the preoperative care of ACL-injured individuals. Delayed compared to early ACLR is unlikely to result in postoperative differences in secondary knee pathologies (incidence of meniscal/ chondral lesions, postoperative infection, graft rupture) and functional outcomes, Matthewson, 2019, as well as two year self-reported knee function, Frobell, 2010.
Based on the studies included in this review, Carter, 2020, the preoperative or post-injury training protocols (4 to 6 weeks, 2 to 4 times per week) should contain muscle control and co-contraction exercises of the knee muscles with particular attention of the quadriceps as well as strengthening (open and closed chain) and stretching exercises of the lower limb. Moreover, advanced neuromuscular (perturbation, balance, stability, proprioceptive exercises) as well as plyometric exercises (e.g. single leg hops with soft landings) need to be considered.
In Alshewaiver et al. 2015, the average duration of the preoperative intervention was 14 weeks (range 3-24 weeks) with the frequency of sessions ranging between 2 – 4 sessions per week. Thus, on average, patients received a total of 27 pre-operative treatment sessions. This number of treatment sessions is resource intensive and in the current economic climate, with healthcare budgets under increasing financial pressure, the clinical applicability of this may be questioned. However, in the studies by Frobell et al. using a delayed approach 50% of patients avoided the need for surgery with no implications on clinical outcomes in the intervention group up to 5 years after injury.
Alshewaiver et al. 2015 found no significant difference was found in patient reported pain between the intervention and control groups in any of the studies.
Range of motion
In Alshewaiver et al. 2015 review, range of motion was used as an outcome in one study. There was no significant difference in range of motion between the two rehabilitation programmes using open and closed kinetic chain exercises.
Alshewaiver et al. 2015, found that outcomes of knee-related symptoms, including swelling, were measured in four studies. No significant difference in symptoms between the control and intervention groups were found.
In Alshewaiver et al. 2015, review one studie, Fitzgerald et al. 2010, examined the effect of perturbation training on episodes of giving way of the knee. They found that a greater number of subjects in the control group had increased episodes of giving way (p < 0.05).
In Giesche et al. 2020 review, one study by Keays et al. 2006, assessed knee joint stability, balance and agility. They found significantly higher improvements in each of these outcomes for the prehabilitation compared to the control groups.
In review by Alshewaiver et al. 2015, two studies found a significant improvement in physical function in the intervention group compared to the control although five studies found no significant difference in physical function between the groups
Quadriceps strength / Knee extensor strength deficits
Carter, 2020, review demonstrates very low quality evidence to support the use of Pre-op to improve knee extensor strength deficits after ACLR at 3- and 6-months post-operatively.
Alshewaiver et al. 2015 review showed that muscle (quadriceps and/or hamstring) strength and function were measured in four studies using a Biodex isokinetic dynamometer. Tagesson et al, reported that the intervention group had greater quadriceps muscle strength, however, no other significant differences in strength were found. Hartigan et al. found that quadriceps strength increased in both groups, although there was no significant difference between the groups. The remaining two studies found no significant difference in muscle strength between the intervention and control groups. Giesche et al. 2020, did not find peak torque values systematically between groups neither at baseline nor at pre-surgery from pre-prehabilitation / baseline to pre-surgery.
However in Giesche et al. 2020, systematic review Kim et al., 2015, observed a significant lower post-operative loss of the limb symmetry of the knee extensor strength relative to baseline in the prehabilitation compared to the control group at both an angular velocity of 60 ̊/s (-5.7% vs. -13%) and 180 ̊/s (-6.7% vs. -10.4%). This resulted in a more symmetric index at both 60 ̊/s (prehab: 28.5 ± 9.0 vs. control: 36.5 ± 10.7, p < .05, d = 0.8) and 180 ̊/s (23.3 ± 9.0 vs. 27.9±12.6, p < .05, d = 0.4) in the intervention group. Similarly, Shaarani et al., 2015, found a trend for a lower reduction of the baseline limb symmetry index in the prehabilitation compared to the control group (-20.3% vs. -24.8%, p > .05).
In Giesche et al. 2020 systematic review two studies assessed by Keays et al. 2006, Shaarani et al. 2015 no significant advantage for hamstring peak torque was found for the prehabilitation group at pre-surgery or prehabilitation to 3 months, found no significant advantage for the prehabilitation group.
Single leg hop distance/Limb symmetry index
Carter, 2020, review demonstrates very low quality evidence to support the use of Pre-op to improve single leg hop distance/LSI, limb symmetry after ACLR at 3- and 6-months post-operatively.
In Giesche et al. 2020 systematic review, one study, Shaarani et al. 2015, measured the single-leg hop for distance performance. Compared to the control group, the authors found higher increases of the single-leg hop scores of the injured limb in the prehabilitation (13.5%) compared to the control group (9%). These improvements were significant (p < .05) in the prehabilitation group only. However, both groups did not differ significantly neither at baseline nor at pre-surgery (p > .05) From baseline to 12-week post op, two studies, Shaarani et al. 2015, Kim, 2015, investigated the effects of prehabilitation on the single-leg jump performance Kim et al., 2015, reported a significant increase of the limb symmetry index for the prehabilitation (75.1 to 85.3%, p < .05, d = 1.1), but not for the control group (76.5 to 80.5%, p > .05, d = 0.4). Shaarani et al., 2015, found a reduction of the single-leg jump test scores of the injured limb relative to pre-surgery in both groups (p < .05).
Carter, 2020, review demonstrates very low quality evidence to support the use of Pre-op to improve limb symmetry during gait after ACLR at 3- and 6-months post-operatively.
Alshewaiver et al. 2015, found that quadriceps strength and knee excursions were more symmetrical 6 months postoperatively in the intervention group that received perturbation training and progressive quadriceps strength training than the control group who received strength training alone.
Subjective knee scores
Carter, 2020, review demonstrates very low quality evidence to support the use of Pre-op to improve the scores for the Modified Cincinnati Knee Rating System after ACLR (3- and 6-months post- operatively).
Alshewaiver et al. 2015 review demonstrates that Quality of life was examined in three studies using a subscale of the Knee Injury and Osteoarthritis Outcome Score. Whilst there was a significant improvement in quality of life from baseline following intervention in both groups, none of the studies reported any significant difference in quality of life between the control and intervention groups.
For self-reported outcomes in Giesche et al. 2020 systematic review, two studies, Keays et al. 2006, Zduński, 2015 examined the effects of prehabilitation on pre-operative self-reported knee function, Noyes, Trust Keays et al. 2006 and Lysholm score Zduński, 2015 and found Significant higher improvements for the prehabilitation compared to the control groups for both the Noyes (d = 1.1) and Trust (d = 1.2) scores. One study by Zdunski et al., 2015, reported a mean pre- to post change in Lysholm score from 46 to 66 points in the prehabilitation group and from 59 to 64 points in the control group. Similar findings were gained by another study, Shaarani et al. 2015 which observed a significant increase of the mean Cincinnati score (62.6 to 76.5 vs. 66 to 70 points) in the prehabilitation group only. At pre-surgery, both groups did not differ significantly. However, the effects of prehabilitation on 12-weeks postoperative self-reported knee function in the modified Cincinnati scores increased significantly from baseline to 12-weeks post-surgery (prehab: 62.6 to 85.3, p < .05; controls: 66 to 77.6, p > .05) resulting in a significant higher mean score for the prehabilitation compared to the control group (85.3 vs. 77.6, p < .05).
After two years one group compared the level of self-reported knee function ((International Knee Documentation Committee, Knee injury and Osteoarthritis Outcome Score)). Both studies indicated a superior effect of prehabilitation, when compared to usual care. In both studies, the prehabilitation cohort exhibited significantly higher baseline/preoperative scores than the controls. Controlled for this confounder, the prehabilitation cohort continued to have significantly higher Knee injury and Osteoarthritis Outcome Score values in all subscales and International Knee Documentation Committee scores (84 vs. 71) at 2-years post-surgery.
Return to pre-injury / sport
Carter, 2020, found no evidence exists to support the use of prehabilitation to improve return to pre-injury levels of physical activity, function or psychological readiness post-surgery.
Giesche et al. 2020 systematic review for return to sport duration and rates there was a trend for significantly faster RTS of the prehabilitation compared to the control group 34.18 ± 4.14 vs. 42.5 ± 10.46 weeks, p = .055). Nevertheless, no re-injuries occurred in the prehabilitation group during a follow-up period of 15 month after reconstruction. According to another study a significantly higher share of participants from the prehabilitation compared to the control group returned to their preinjury sport at the two years’ follow-up (72% vs. 63%; p < .05).
Giesche et al. 2020 review is that prehabilitation may reduce the decline of postoperative neuromuscular performance of the lower limb
The clinical implications of this review is that prehabilitation may reduce the decline of postoperative neuromuscular performance of the lower limb and improve self-reported knee function and RTS success. It appears plausible that additional preoperative training prior to a delayed surgery may result in better postoperative function compared to early surgery.
The authors concluded low to moderate quality evidence indicates that exercises have a positive impact on pre-operative and postoperative functional performance. Low-level quality evidence supports the superiority of prehabilitation in terms of self-reported knee function at both pre-reconstruction and three months as well as two years after ACLR.