Anterior cruciate ligament instability and reconstruction. Review of current trends in treatment

Nonsurgical or Surgical Treatment of ACL Injuries: Knee Function, Sports Participation, and Knee Reinjury: The Delaware-Oslo ACL Cohort Study

BACKGROUND

While there are many opinions about the expected knee function, sports participation, and risk of knee reinjury following nonsurgical treatment of injuries of the anterior cruciate ligament (ACL), there is a lack of knowledge about the clinical course following nonsurgical treatment compared with that after surgical treatment.

METHODS

This prospective cohort study included 143 patients with an ACL injury. Isokinetic knee extension and flexion strength and patient-reported knee function as recorded on the International Knee Documentation Committee (IKDC) 2000 form were collected at baseline, six weeks, and two years. Sports participation was reported monthly for two years with use of an online activity survey. Knee reinjuries were reported at the follow-up evaluations and in a monthly online survey. Repeated analysis of variance (ANOVA), generalized estimating equation (GEE) models, and Cox regression analysis were used to analyze group differences in functional outcomes, sports participation, and knee reinjuries, respectively.

RESULTS

The surgically treated patients (n = 100) were significantly younger, more likely to participate in level-I sports, and less likely to participate in level-II sports prior to injury than the nonsurgically treated patients (n = 43). There were no significant group-by-time effects on functional outcome. The crude analysis showed that surgically treated patients were more likely to sustain a knee reinjury and to participate in level-I sports in the second year of the follow-up period. After propensity score adjustment, these differences were nonsignificant; however, the nonsurgically treated patients were significantly more likely to participate in level-II sports during the first year of the follow-up period and in level-III sports over the two years. After two years, 30% of all patients had an extensor strength deficit, 31% had a flexor strength deficit, 20% had patient-reported knee function below the normal range, and 20% had experienced knee reinjury.

CONCLUSIONS

There were few differences between the clinical courses following nonsurgical and surgical treatment of ACL injury in this prospective cohort study. Regardless of treatment course, a considerable number of patients did not fully recover following the ACL injury, and future work should focus on improving the outcomes for these patients.

LEVEL OF EVIDENCE

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Online registration of monthly sports participation after anterior cruciate ligament injury: a reliability and validity study

BACKGROUND

The current methods measuring sports activity after anterior cruciate ligament (ACL) injury are commonly restricted to the most knee-demanding sports, and do not consider participation in multiple sports. We therefore developed an online activity survey to prospectively record the monthly participation in all major sports relevant to our patient-group.

OBJECTIVE

To assess the reliability, content validity and concurrent validity of the survey and to evaluate if it provided more complete data on sports participation than a routine activity questionnaire.

METHODS

145 consecutively included ACL-injured patients were eligible for the reliability study. The retest of the online activity survey was performed 2 days after the test response had been recorded. A subsample of 88 ACL-reconstructed patients was included in the validity study. The ACL-reconstructed patients completed the online activity survey from the first to the 12th postoperative month, and a routine activity questionnaire 6 and 12 months postoperatively.

RESULTS

The online activity survey was highly reliable (κ ranging from 0.81 to 1). It contained all the common sports reported on the routine activity questionnaire. There was a substantial agreement between the two methods on return to preinjury main sport (κ=0.71 and 0.74 at 6 and 12 months postoperatively). The online activity survey revealed that a significantly higher number of patients reported to participate in running, cycling and strength training, and patients reported to participate in a greater number of sports.

CONCLUSIONS

The online activity survey is a highly reliable way of recording detailed changes in sports participation after ACL injury. The findings of this study support the content and concurrent validity of the survey, and suggest that the online activity survey can provide more complete data on sports participation than a routine activity questionnaire.

A pair-matched comparison of return to pivoting sports at 1 year in anterior cruciate ligament-injured patients after a nonoperative versus an operative treatment course

BACKGROUND

Patients usually return to pivoting sports between 6 months and 1 year after anterior cruciate ligament (ACL) reconstruction, but no matched study has so far examined 1-year return to sport rates in nonoperatively and operatively treated ACL-injured patients.

HYPOTHESIS

Anterior cruciate ligament-injured patients following a nonoperative treatment course, including recommendation of activity modification, will have lower return to pivoting sport rates than operatively treated patients 1 year after baseline testing/surgery, when matched by preinjury sports activity, age, and sex.

STUDY DESIGN

Cohort study; level of evidence, 3.

METHODS

Sixty-nine nonoperatively treated ACL-injured patients were pair-matched with 69 operatively treated patients (n = 138), based on specific preinjury sport, age, and sex. Nonoperatively treated patients were recommended not to return to level I sports. Patients were defined as nonoperatively or operatively treated according to their status at follow-up. The baseline and follow-up testing included registration of sports participation, KT-1000 arthrometer measurements, 4 hop tests, and patient-reported outcome measures. McNemars test and paired t tests or Wilcoxon test were used to compare outcomes of nonoperatively and operatively treated patients.

RESULTS

No significant baseline differences were found. At 12.9 ± 1.2 months (mean ± standard deviation) after baseline testing (nonoperative) and 12.7 ± 1.2 months after surgery (operative), there was no significant difference in overall return to sport rates (nonoperative: 68.1%, operative: 68.1%, P = 1.00), or in return to level I sport rates (nonoperative: 54.8%, operative: 61.9%, P = .66). Nonoperatively treated patients who participated in level I sports before injury had a significantly lower return to sport rate (54.8%) than nonoperatively treated patients who participated in level II sports (88.9%, P = .003). The nonoperatively treated patients had significantly higher knee joint laxity, but significantly better hop test limb symmetry indexes, Knee Outcome Survey Activities of Daily Living scores, and International Knee Documentation Committee Subjective Knee Form 2000 scores. None of the functional differences was larger than the smallest detectable difference.

CONCLUSION

Anterior cruciate ligament-injured patients following a nonoperative treatment course, including recommendations of activity modifications, and operatively treated patients did not have significantly different rates of returning to pivoting sports after 1 year in this pair-matched cohort study. Clinicians should be aware of a potentially high level of noncompliance to recommendations of activity modifications. Although these results show that it is possible for nonoperatively treated patients to return to sport after rehabilitation, future follow-ups are needed to examine whether these patients maintain sports participation over time, and what long-term consequences they may suffer regarding subsequent injuries and knee osteoarthritis.

IKDC or KOOS: which one captures symptoms and disabilities most important to patients who have undergone initial anterior cruciate ligament reconstruction?

BACKGROUND

Knee-specific patient-reported outcome measures are frequently used after anterior cruciate ligament reconstruction but little is known about whether they measure outcomes important to patients.

PURPOSE

The aim of this study was to identify which instrument, the Knee injury and Osteoarthritis Outcome Score (KOOS) or the International Knee Documentation Committee Subjective Knee Form (IKDC), captures symptoms and disabilities most important to patients who have undergone initial anterior cruciate ligament reconstruction.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Data were collected from 126 participants of an Internet knee forum. A self-reported online questionnaire was developed consisting of demographic and surgical data, the Tegner Activity Scale, and 49 consolidated items from the KOOS and the IKDC. Item importance, frequency, and frequency-importance product were calculated.

RESULTS

Seventy-eight percent of the items from the IKDC were experienced by more than half of the patients, compared with 57% from the KOOS. Items extracted from the Function in Sports/Recreation and Quality of Life KOOS subscales were highly important to this group of patients. For patients 12 months or more after anterior cruciate ligament reconstruction, 94% of the IKDC items had a frequency-importance product of 1 or less compared with 86% of the KOOS items.

CONCLUSION

Overall, the IKDC items outperformed the KOOS items on all of the 5 criteria with the exception of the frequency-importance product for patients who were 12 months after anterior cruciate ligament reconstruction. The KOOS Function in Sports/Recreation and Knee-Related Quality of Life subscales outperformed the IKDC for the total cohort as well as for male and female subgroups. However, differences in individual items were not always evident from either total scale or subscale ratings. Studies should use patient-reported outcomes that reflect patients' most important concerns and further prospective longitudinal research is required in this area.

Early active extension after anterior cruciate ligament reconstruction does not result in increased laxity of the knee

If permission of full active and passive extension immediately after an anterior cruciate ligament (ACL) reconstruction will increase the post-operative laxity of the knee has been a subject of discussion. We investigated whether a post-operative rehabilitation protocol including active and passive extension without any restrictions in extension immediately after an ACL reconstruction would increase the post-operative anterior-posterior knee laxity (A-P laxity). Our hypothesis was that full active and passive extension immediately after an ACL reconstruction would have no effect on the A-P laxity and clinical results up to 2 years after the operation. Twenty-two consecutive patients (14 men, 8 women, median age 21 years, range 17-41) were included. All the patients had a unilateral ACL rupture and no other ligament injuries or any other history of previous knee injuries. The surgical procedure was identical in all patients and one experienced surgeon operated on all the patients, using the bone-patellar tendon-bone autograft. The post-operative rehabilitation programme was identical in both groups, except for extension training during the first 4 weeks post-operatively. The patients were randomly allocated to post-operative rehabilitation programmes either allowing (Group A, n=11) or not allowing [Group B (30 to -10 degrees ), n=11] full active and passive extension immediately after the operation. They were evaluated pre-operatively and at 6 months and 2 years after the reconstruction. To evaluate the A-P knee laxity, radiostereometric analysis (RSA) and KT-1000 arthrometer (KT-1000) measurements were used, range of motion, Lysholm score, Tegner activity level, the International Knee Documentation Committee (IKDC) evaluation system and one-leg-hop test quotient were used. Pre-operatively, the RSA measurements revealed side-to-side differences in Group A of 8.6 mm (2.3-15.4), median (range) and in Group B of 7.2 mm (2.2-17.4) (n.s.). The corresponding KT-1000 values were for Group A, 2.0 mm (0-8.0) and Group B, 4.0 mm (0-10.0) (n.s.). At 2 years, the differences between the two groups were minimal, regardless of the method that had been used. The RSA measurements in Group A were 2.7 mm (0-10.7) and in Group B 2.8 (-1.8 to 9.5). The KT-1000 values were for Group A, 1.0 mm (-1.5 to 3.5), and for Group B, 0.5 mm (-1.0 to 4.0), without any significant differences between the groups. Nor did the Lysholm score, Tegner activity level, IKDC or one-leg-hop test differ. Early active and passive extension training, without any restrictions in extension, immediately after an ACL reconstruction using bone-patellar tendon-bone graft did not increase post-operative knee laxity up to 2 years after the ACL reconstruction.

Development of a strength test battery for evaluating leg muscle power after anterior cruciate ligament injury and reconstruction

A more sports-specific and detailed strength assessment has been advocated for patients after anterior cruciate ligament (ACL) injury and reconstruction. The purpose of this study was to develop a test battery of lower extremity strength tests with high ability to discriminate between leg power development on the injured and uninjured sides in patients after ACL injury and in patients who have undergone ACL reconstruction. Twenty-three patients were tested 6 months after ACL injury and 44 patients were tested 6 months after ACL reconstruction. Twenty-four of the 44 patients were operated on using a hamstrings graft and 20 patients were operated on using a patellar tendon graft. All the patients performed a test battery of three strength tests for each leg in a randomised order. The three strength tests were chosen to reflect quadriceps and hamstring muscular power in a knee-extension and a knee-flexion test (open kinetic chain) and lower-extremity muscular power in a leg-press test (closed kinetic chain). There was a higher sensitivity for the test battery to discriminate abnormal leg power compared with any of the three strength tests individually. Nine out of ten patients after ACL reconstruction and six out of ten of the patients after ACL injury exhibited abnormal leg power symmetry using the test battery. Thus, this test battery had high ability in terms of discriminating between the leg power performance on the injured and uninjured side, both in patients with an ACL injury and in patients who have undergone ACL reconstruction. It is concluded that a test battery consisting of a knee-extension, knee-flexion and leg-press muscle power test had high ability to determine deficits in leg power 6 months after ACL injury and reconstruction. Only a minority of the patients had restored leg muscle power. The clinical relevance is that the test battery may contribute to the decision-making process when deciding whether and when patients can safely return to strenuous physical activities after an ACL injury or reconstruction.

Anterior cruciate ligament insufficiency: does delay in index surgery affect outcome in recreational athletes

The aim of the study was to see if delay in anterior cruciate ligament (ACL) reconstruction affects post-reconstruction outcome in recreational athletes. Sixty-two recreational athletes who had arthroscopic ACL reconstructions using quadruple hamstring grafts between 1997 and 2000 were retrospectively evaluated. Patients with less than 2 years' follow-up, those with multi-ligament injuries, reconstructions for previous failed repairs, those whose injury date was unknown, those with pre-injury Tegner activity level greater than 7 (competitive athletes) and those lost to follow-up were all excluded. Forty-six patients (38 males) were entered. The mean follow up was 38 months and the mean time from injury to index ACL reconstruction was 27 months. Apart from two revisions there were no other significant complications. Forty-one (89%) patients were evaluated in a review clinic. There was a significant improvement in the post-reconstruction Lysholm scores and an improvement in the Tegner scores. The Spearman's correlation coefficient between postoperative Lysholm score and the delay until surgery was -0.18 and the correlation coefficient between postoperative Tegner scores and the delay until surgery was 0.14. Thirty-five patients returned to sporting activity. Thirty-seven rated their knee as being normal or nearly normal and 35 said that their knee function was as they had expected it to be. Late ACL reconstruction does not adversely affect the outcome in recreational athletes. ACL reconstruction should be offered to these patients as there is a significant improvement in the knee function and patients are satisfied with the results.

Do early quadriceps exercises affect the outcome of ACL reconstruction? A randomised controlled trial

A prospective, blinded, randomised controlled trial investigated the effectiveness of quadriceps exercises following anterior cruciate ligament reconstruction. A treatment group (Quadriceps exercise group) performed straight leg raises and isometric quadriceps contractions throughout the first two postoperative weeks, and a second group (No quadriceps exercise group) did not. A battery of outcome measures assessed subjects postoperatively at day one, two weeks, and one, three and six months. A total of 103 patients (Quadriceps exercise n = 48, No quadriceps exercise n = 55) commenced the study with 91 subjects available at final follow up (Quadriceps exercise n = 47, No quadriceps exercise n = 44). Performance of quadriceps exercises significantly improved a number of knee flexion and extension range of motion measurements (p = 0.01 to 0.04). No significant differences were found between the two groups at any postoperative period for quadriceps lag (p = 0.36), functional hop testing (p = 0.49 to 0.51), isokinetic quadriceps strength (p = 0.70 to 0.72), the majority of numerical analogue scores (p = 0.1 to 0.94) and Cincinnati scores (p = 0.10 to 0.84). Subjects performing quadriceps exercises reported significantly higher pain scores with exercise on the first postoperative day (p = 0.02). At six months postoperatively, the Quadriceps exercise subjects reported significantly more favourable Cincinnati scores for symptoms (p = 0.005) and problems with sport (p = 0.05). While average knee laxity was not significantly different between treatment groups over time (p = 0.27 to 0.94), quadriceps exercise performance was associated with a significantly lower incidence of abnormal knee laxity. Isometric quadriceps exercises and straight leg raises can be safely prescribed during the first two postoperative weeks and confer advantages for faster recovery of knee range of motion and stability. It remains to be proven whether the magnitude of differences between groups is clinically significant.

A prospective randomized comparison of bone-patellar tendon-bone and hamstring grafts for anterior cruciate ligament reconstruction

PURPOSE

The aim of this study was to compare the results after arthroscopic anterior cruciate ligament (ACL) reconstruction using central-third, bone-patellar tendon-bone (BPTB group), 3-strand semitendinosus (ST group), or 4-strand semitendinosus/gracilis (ST/G group) autografts.

TYPE OF STUDY

Prospective randomized trial.

METHODS

A randomized series of 134 patients, all with unilateral ACL rupture was included in the study. In all 3 groups, interference screw fixation of the graft was used at both ends and 125 of 134 (93%) of the patients returned for the follow-up examination after 26 months (range, 20 to 43 months). The preoperative assessments in all 3 groups were similar in terms of gender, Tegner activity level, Lysholm score, KT-1000 measurements, 1-leg hop test, and the knee-walking test.

RESULTS

At follow-up, the knee-walking test was significantly worse in the BPTB group than in the ST group (P = .0004) and ST/G group (P < .0001). Furthermore, the knee-walking test was significantly worse at follow-up than preoperatively in the BPTB group (P < .0001). The corresponding findings were not made in the other 2 groups. A significant reduction in knee laxity and an increase in activity level compared with the preoperative assessments were found in all 3 groups, without any significant differences between the groups.

CONCLUSIONS

Two years after ACL reconstruction, the use of ST and ST/G autografts rendered significantly less discomfort during the knee-walking test than the use of BPTB autografts. However, in terms of functional outcome and knee laxity, the groups displayed no significant differences.

LEVEL OF EVIDENCE

Level I.

Patellar tendon or semitendinosus tendon autografts for anterior cruciate ligament reconstruction? A prospective randomized study with a two-year follow-up

BACKGROUND

There are well-known problems with the use of bone-patellar tendon-bone autografts for anterior cruciate ligament reconstruction, especially in terms of donor site morbidity. Hamstring tendon grafts have been increasingly used as an alternative, but there are very few controlled studies comparing the methods.

HYPOTHESIS

Use of semitendinosus tendon grafts will cause less donor site morbidity and result in better knee-walking ability.

STUDY DESIGN

Prospective randomized clinical trial.

METHODS

Seventy-one patients who had a unilateral anterior cruciate ligament rupture underwent arthroscopic reconstruction with interference screw fixation and use of either bone-patellar tendon-bone or semitendinosus tendon graft. Outcome assessment was performed by physiotherapists not involved in the patients' care.

RESULTS

At the 2-year follow-up, no differences were found in terms of the Lysholm score, Tegner activity level, KT-1000 arthrometer side-to-side laxity measurement, single-legged hop test, or International Knee Documentation Committee classification results. The knee-walking test was rated difficult or impossible to perform by 53% of the bone-patellar tendon-bone group and by only 23% of the semitendinosus graft patients, a significant difference.

CONCLUSIONS

The semitendinosus tendon graft is at least an equivalent option to the bone-patellar tendon-bone graft for anterior cruciate ligament reconstruction, and we recommend its use.

An Australian survey of in-patient protocols for quadriceps exercises following anterior cruciate ligament reconstruction

Current practices regarding in-patient strengthening exercise prescription following anterior cruclate ligament (ACL) reconstruction are scarcely addressed in the literature and remain unreported for Australian hospitals. An observational, questionnaire-based study was used to Investigate in-patient quadriceps strengthening practices in Australian hospitals after ACL reconstruction. Questionnaires were returned by 248 hospitals (76% response rate) and of these 88 hospitals reported performing ACL reconstructions. These hospitals were surveyed to determine the types of quadriceps strengthening exercises prescribed during the in-patient period. Information was sought regarding routine management strengthening practices. A variety of quadriceps exercises such as static quadriceps contractions (SQC), straight leg raises (SLR) and inner range quadriceps (IRQ) were frequently prescribed, although no standard practice currently exists. Static quadriceps exercises were prescribed by 91% of hospitals surveyed, IRQ exercises were used by 30%, and 49% reported using SLR exercises. Current literature tends to support the performance of SQC and SLR exercises during the early postoperative period following ACL reconstruction. Conversely, current clinical practice is incongruent with regard to the scientific recommendations for IRQ performance.

The anterior cruciate ligament enigma. Injury mechanisms and prevention

The reasons for the higher frequency of anterior cruciate ligament injuries in women are largely conjecture. These injuries may result from direct contact or, more frequently, from no direct contact to the knee during activities that most athletes consider routine to their sport. This implies that there are intrinsic factors that lead to anterior cruciate ligament rupture. For the anterior cruciate ligament to tear, there must be excess anterior tibial translation or rotation of the femur on the tibia. In the former case, the tibia can move anteriorly during quadriceps activation that is not counterbalanced by hamstring activation. Patients describe their injury as occurring when landing, stopping, or when planting to change directions. The knee typically was near full extension. Mechanically, the angle of the patellar tendon and tibial shaft increases as the knee approaches full extension. This gives a mechanical advantage to the quadriceps. During cutting maneuvers, athletes tend to cut with a knee near extension (0 degree-20 degrees) when the quadriceps are active and the hamstrings are neither very active nor at a knee flexion angle that offers much of a mechanical advantage. In performing cutting and landing maneuvers, women tend to perform the activities more erect; that is, with their knee and hips closer to extension. One possible factor to help reduce the frequency of anterior cruciate ligament injuries in women may be in proper instruction for performing cutting and landing maneuvers which will lower their center of gravity thereby denying the quadriceps the opportunity to shift the tibia anteriorly.