No Relationship Between Preoperative and Early Postoperative Strength After ACL Reconstruction

Abstract

Context: All rehabilitative programs before anterior cruciate ligament (ACL) reconstructive surgery, which are focused on recovery of proprioception and muscular strength, are defined as prehabilitation. While it has shown that prehabilitation positively affects the overall outcome after ACL reconstruction, it is still controversial whether preoperatively enhancing quadriceps strength has some beneficial effect on postoperative strength, mainly during the first period. Objective: To determine whether there is any relationship between preoperative and early postoperative quadriceps strength. Design: Case control. Setting: University research laboratory. Participants: Fifty-nine males (18–33 y; age: 23.69 [0.71] y) who underwent ACL reconstruction with patellar-tendon autograft were examined the day before surgery, and at 60 and 90 days after surgery. Main Outcome Measures: The limb symmetry index (LSI) was quantified for maximal voluntary isometric contraction of the knee extensor muscles and of the knee flexor muscles at 90° joint angle. A k-means analysis was performed on either quadriceps or hamstrings LSI before surgery to classify the patients in high and low preoperative LSI clusters. Differences in postoperative LSI were then evaluated between the high and low preoperative LSI clusters. Results: Following surgery, there were no differences in the quadriceps LSI between patients with high and low preoperative quadriceps LSI. Sixty days after surgery, the hamstrings LSI was higher in patients with high than low preoperative hamstrings LSI (84.0 [13.0]% vs 75.4 [15.9]%; P < .05). Conclusions: Findings suggest that quadriceps strength deficit is related to the ACL injury and increases further after the reconstruction without any correlation between the preoperative and postoperative values. Therefore, it appears that there is no need to delay surgery in order to increase the preoperative quadriceps strength before surgery.

Is Pre-operative Quadriceps Strength a Predictive Factor for the Outcomes of Anterior Cruciate Ligament Reconstructions

“…The follow-up duration of the supportive studies ranged from 3 months to 2 years. On the contrary, Mariani PP et al [26] (moderate quality) reported that there was no association between pre-operative and post-operative QSI. In the study, quadriceps strength was measured by MVIC test early after injury, and at 2 and 3 months after surgery.…”

“…The score of quality assessment ranged from 44-78, with a mean of 62 ± 10.4. There were nine studies of moderate quality [11][12][13][14][22][23][24][25][26]] and 3 studies were low quality [27][28][29][30][31][32][33][34][35][36][37][38][39]. The scores of each individual study are shown in ▶Table 1.…”

“…Of the included studies, 6 studies recorded pre-injury activity level of participants. Among the 12 studies, participants from 6 studies were reconstructed with bone patellar tendon bone (BPTB) autograft [11,12,[25][26][27]29], 4 studies with hamstring autograft or allograft [13,14,22,23], and another 2 studies reconstructed with either BPTB or hamstring autograft [24,28]. Nine studies provided their own postoperative rehabilitation protocols with the duration ranging from 7…”

“…weeks to 1 year. All of the reported rehabilitation protocols included muscle strengthening exercises, proprioception and balance training as well as plyometric training [11][12][13][14][22][23][24][25][26][27][28][29]. The treatment protocols of each individual study are listed in ▶Table 3.…”

“…Quadriceps strength was measured by different dynamometers during maximum voluntary isometric contractions or isokinetic contractions. Five studies assessed quadriceps strength through maximum voluntary isometric test (MVIC) [11,13,22,26,29], and the other 7 studies assessed through isokinetic test at different speeds [12, 14, 23-25, 27, 28]. For the units of quadriceps strength, 8 studies [12, 13, 23-26, 28, 29] used quadriceps strength symmetry index (QSI) which was calculated as the quadriceps peak torque on the injured side divided by the quadriceps peak torque on the uninjured side, three studies [11,22,27] used normalized strength (peak torque/body weight) and one study used both QSI and normalized strength [14].…”