ABSTRACT
BACKGROUND: Preventing and mitigating the risk of reinjury after anterior cruciate ligament reconstruction (ACLR) rest on variables including age, surgical restoration of knee stability, adequate physical function, and thorough and complete postoperative rehabilitation, but to what degree these factors influence return to sport is unclear. PURPOSE: To investigate factors predictive of return to sport 12 months after ACLR. The factors specifically evaluated were strength, hop function, self-reported knee function, patient age, and quality of postoperative rehabilitation. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: This study evaluated 113 patients approximately 12 months after ACLR using a rehabilitation grading tool, the subjective International Knee Documentation Committee (IKDC) form, and a return-to-sport battery consisting of maximal isokinetic quadriceps and hamstring strength and 4 functional hop tests. Mann-Whitney U tests and chi-square analyses were used to determine differences between patients who had or had not returned to sport. A subsequent binary logistic hierarchical regression determined the factors predictive of a patient's return to sport. In those patients who had returned to sport, relationships between either age or level of rehabilitation and passing the return-to-sport battery were also investigated. RESULTS: Complete rehabilitation (adjusted odds ratio [OR], 7.95; P = .009), age ≤25 years (adjusted OR, 3.84; P = .024), and higher IKDC scores (P < .001) were predictive of return to sport at 12 months. In participants who had returned to sport, 21% passed the return-to-sport battery compared with only 5% who did not. Of those who had returned to sport, 37% who underwent complete rehabilitation passed the return-to-sport battery as opposed to 5% who underwent incomplete rehabilitation. In patients aged ≤25 years, only 48% underwent complete rehabilitation, despite having returned to sport. Additionally, in this group of patients, 40% underwent complete rehabilitation and passed the physical performance battery as opposed to only 4% who did not undergo complete rehabilitation. CONCLUSION: Younger patients and higher subjective IKDC scores were predictive of return to sport. Patients who completed 6 months of rehabilitation incorporating jumping and agility tasks had a higher rate of return to sport, suggesting that postoperative rehabilitation is important in predicting return to sport. Specialists and physical therapists alike should stress the importance of thorough postoperative rehabilitation and adequate neuromuscular strength and function to patients whose goals are to return to sport.
ABSTRACT
BACKGROUND: Limb symmetry after anterior cruciate ligament reconstruction may be evaluated using maximal strength and hop tests, which are typically reported using Limb Symmetry Indices (LSIs) which may overestimate function. PURPOSE: The purpose of this study was to compare the Back in Action (BIA) test battery to standard hop and muscle strength tests used to determine readiness to return to sport (RTS). STUDY DESIGN: Prospective cohort. METHODS: Over two test sessions, 40 ACLR patients were assessed at a mean 11.3 months post-surgery. Initially, participants completed the 6 m timed hop and the single, triple and triple crossover hops for distance, and isokinetic knee extensor and flexor strength assessment. The second session involved completion of the BIA battery, including stability tests, single and double leg countermovement jumps (CMJ), and plyometric, speedy jump, and quick feet tests. Pass rates for test batteries were statistically compared, including the BIA, a four-hop battery (≥90% LSI in every one of the four hop tests) and a combined 4-hop and strength battery (≥90% LSI in every one of the four hop tests, as well as ≥90% for both peak knee extensor and flexor strength). LSI differences between the four standard hop tests and the BIA single limb functional tests (the single limb CMJ and the speedy jump test) were evaluated. RESULTS: Significantly less participants passed the BIA battery (n = 1, 2.5%), compared with the four-hop test battery (n = 27, 67.5%) (p<0.001) and the four-hop test and isokinetic strength battery (n = 17, 42.5%) (p<0.001). Collectively, LSI's for the standard hop tests were significantly higher than the BIA functional single limb tests (difference = 12.9%, 95% CI: 11.1% to 14.6%, p<0.001). CONCLUSION: The BIA test battery appears to include some single limb functional tests that are more physically challenging than standard hop and isokinetic strength tests, highlighted by the significantly lower mean LSI's during the single limb BIA tests and the lower pass rate when employing the BIA protocol. LEVEL OF EVIDENCE: Level 4, case series.
ABSTRACT
PURPOSE: To investigate strength and functional symmetry during common tests in patients after anterior cruciate ligament reconstruction (ACLR), and its association with post-operative rehabilitation. METHODS: At a median 11.0 months post-surgery (range 10-14), 111 ACLR patients were assessed. A rehabilitation grading tool was employed to evaluate the duration and supervision of rehabilitation, as well as whether structured jumping, landing and agility exercises were undertaken. Patients completed the Noyes Activity Score (NSARS), maximal isokinetic knee extensor and flexor strength assessment, and a 4-hop test battery. Limb Symmetry Indices (LSIs) were calculated, presented for the entire group and also stratified by activity level. ANOVA evaluated differences between the operated and unaffected limbs across all tests. Correlations were undertaken to assess the relationship between post-operative rehabilitation and objective test LSIs. RESULTS: The unaffected limb was significantly better (p < 0.0001) than the operated limb for all tests. Only 52-61 patients (47-55%) demonstrated LSIs ≥ 90% for each of the hop tests. Only 34 (30.6%) and 61 (55.0%) patients were ≥ 90% LSI for peak quadriceps and hamstring strength, respectively. Specifically in patients actively participating in jumping, pivoting, cutting, twisting and/or turning sports, 21 patients (36.8%) still demonstrated an LSI < 90% for the single hop for distance, with 37 patients (65.0%) at < 90% for peak knee extension strength. Rehabilitation was significantly associated with the LSIs for all tests. CONCLUSION: Rehabilitation was significantly correlated with limb symmetry, and lower limb symmetry was below recommended criterion for many community-level ACLR patients, including those already engaging in riskier activities. It is clear that many patients are not undertaking the rehabilitation required to address post-operative strength and functional deficits, and are being cleared to return to sport (or are returning on their own accord) without appropriate evaluation and further guidance. LEVEL OF EVIDENCE: IV.
