Susan L. Keays

Factors Involved in the Development of Osteoarthritis after Anterior Cruciate Ligament Surgery

Background The incidence of osteoarthritis after anterior cruciate ligament reconstruction is disturbingly high, with reports of nearly 50% of patients developing mild to moderate osteoarthritis 6 years after surgery. Few studies have assessed the factors involved in the development of osteoarthritis. Hypothesis: The following 10 factors will be found to be predictive of osteoarthritis meniscectomy, chondral damage, patellar tendon grafting, age at surgery, time delay between injury and surgery, type and intensity of postsurgery sport, quadriceps strength, hamstring strength, quadriceps-to-hamstring strength ratio, and residual joint laxity. Study Design Cohort study (prognosis); Level of evidence, 1. Methods Fifty-six subjects with anterior cruciate ligament reconstruction were followed for 6 years after surgery. Assessment included KT-1000 arthrometer testing, isokinetic strength testing, a return-to-sport questionnaire, and a radiograph assessment. A discriminant analysis was performed to assess which of the 10 factors could discriminate between those patients who developed tibiofemoral and patellofemoral osteoarthritis and those who did not. Results Five factors were found to be predictive of tibiofemoral osteoarthritis. Meniscectomy (r = .72) and chondral damage (r = .41) were the strongest discriminators, followed by patellar tendon grafting (r = .37) (χ2 [7, n = 56] = 25.48; P = .001). Weak quadriceps (r = .39) and low quadriceps-to-hamstring strength ratios (r = .6) were very close discriminators (χ2 [8, n = 42] = 15.02; P = .059). For patellofemoral osteoarthritis, meniscectomy (r = .45), chondral damage (r = .75), and age at surgery (r = .65) were predictors or close predictors (χ2 [7, n = 54] = 13.30; P = .065). Conclusion As not all 10 factors studied were predictive of osteoarthritis, the hypothesis was only partially proven. Preventing further meniscal and chondral damage in patients with anterior cruciate ligament deficiency is critical. Grafting using the hamstring tendons and restoration of quadriceps-to-hamstring strength balance are associated with less osteoarthritis.

A 6-Year Follow-up of the Effect of Graft Site on Strength, Stability, Range of Motion, Function, and Joint Degeneration After Anterior Cruciate Ligament Reconstruction Patellar Tendon Versus Semitendinosus and Gracilis Tendon Graft

Background The choice of graft material for anterior cruciate ligament reconstruction remains controversial. Despite the need for well-controlled, long-term outcome studies comparing patellar tendon with hamstring grafting, few studies have followed results for more than 5 years. Hypothesis Graft source will not affect outcome 6 years after reconstruction. Study Design Cohort study; Level of evidence, 2. Methods Sixty-two patients with anterior cruciate ligament reconstruction and 18 uninjured control subjects were studied over 6 years. Thirty-one patients received patellar tendon grafts, and 31 received hamstring tendon grafts. Assessment included knee joint stability, range of motion, muscle strength, subjective function, objective function (running, sidestepping, carioca, and hop tests), and joint degeneration. Results Clinical stability was restored to all patients other than to the 2 hamstring graft recipients who suffered reinjuries. The KT-1000 arthrometer side-to-side differences were similar in the patellar tendon (1.9 mm) and hamstring tendon (2.0 mm) groups but were significantly greater than that of uninjured control subjects (P < .001). There were no significant strength differences between surgical and control groups, although a 6% quadriceps deficit existed after patellar tendon grafting. In the more demanding functional tests (hop and triple-hop indices and carioca), the hamstring graft recipients performed similarly to the control group, whereas a significant difference (P < .05) existed between the patellar tendon graft and the control group. The incidence of early tibiofemoral osteoarthritis was significantly greater after reconstruction using patellar tendon (62%) than after hamstring tendon grafting (33%; P = .002). Conclusion Six-year outcomes were very satisfactory irrespective of graft source. However, reconstruction using the hamstring tendons resulted in improved functional performance and a lower incidence of osteoarthritis.

The relationship between knee strength and functional stability before and after anterior cruciate ligament reconstruction.

Functional stability of the knee is dependent on an intact ligamentous system and the timely and efficient contraction of supporting musculature. The aim of this study was to assess the relationship between muscle strength and functional stability in 31 patients pre‐ and post‐operatively, following a unilateral anterior cruciate ligament rupture. All subjects underwent reconstructive surgery using semitendonosis and gracilis tendons. Isokinetic strength assessment of quadriceps and hamstring muscles was performed at a rate of movement of 60°/s and 120°/s. Functional stability was determined by performance during five functional stability tests that included the shuttle run, side step, carioca, single and triple hop tests. Pearsons correlation coefficient statistics were applied to pre‐operative and post‐operative data respectively. These analyses demonstrated a significant positive correlation between quadriceps strength indices at both testing speeds and the two hop tests pre‐operatively (ps<0.007) and between quadriceps strength indices at both speeds and all five functional tests post‐operatively (ps<0.01). Assessed using Steigers formula, there was a significant increase in the correlation between quadriceps strength indices and three functional tests post‐operatively compared to pre‐operatively (p<0.05). No significant correlation between hamstring strength indices and functional scores existed pre‐ or post‐operatively. This study has shown a significant correlation exists between quadriceps strength indices and functional stability both before and after surgery, this relationship does not reach significance between hamstring strength indices and functional stability.

Strength and function before and after anterior cruciate ligament reconstruction.

Rehabilitation of patients with anterior cruciate ligament injury is a topic of interest among clinicians. Although numerous studies report the deficits after anterior cruciate ligament reconstruction, there are no data available on the changes in strength and functional performance before and 6 months after reconstruction surgery. This is when most patients are returning to sports activities. In the current study 31 patients with complete unilateral anterior cruciate ligament ruptures followed a controlled rehabilitation program emphasizing early range of motion after surgery and quadriceps strengthening before and after undergoing bone-patellar tendon-bone reconstruction. Strength of the hamstrings and quadriceps and five functional activities were assessed at 1 week before and 6 months after surgery. Preoperative strength assessments using a Cybex II dynamometer showed a 12% quadriceps deficit at 60° per second and 9% deficit at 120° per second with no hamstring deficit in the injured leg compared with the uninjured leg. Despite intensive quadriceps training, the postoperative quadriceps deficit increased to 28% at 60° per second and 22% at 120° per second in comparison with the uninjured leg. There was no change in hamstring strength in the injured leg. Most functional measures improved after surgery. The shuttle run improved by 10%, the side step test results improved by 17%, and the carioca test results improved by 23%. No significant difference was found in the results of the hop test. This study highlights the extent of the quadriceps deficits despite functional improvement and the difficulty in restoring quadriceps strength after bone-patellar tendon-bone reconstruction. It also questions the relationship of current functional tests to quadriceps strength and the role of maximum strength testing as a predictor of function and of safe sporting performance.

Muscle strength and function before and after anterior cruciate ligament reconstruction using semitendonosus and gracilis.

This study assessed the quadriceps and hamstring strength before and 6 months after anterior cruciate ligament (ACL) reconstructive surgery using the hamstrings and related the findings to functional performance. Six months after surgery is a critical time for assessment as this is when players are returning to sport. Maximum isokinetic strength of 31 patients with complete unilateral ACL ruptures was measured at speeds of 60 degrees and 120 degrees per second. Functional assessment included the single hop, the triple hop, the shuttle run, side-step and carioca tests. All patients underwent a controlled quadriceps emphasized home-based physiotherapy program both before and after surgery. Results show that before surgery there was a 7.3% quadriceps strength deficit at 60 degrees per second compared to the uninjured leg but no hamstring strength deficit. After surgery there was a statistically significant but relatively small loss of muscle strength. The quadriceps strength deficit had increased to 12% and there was a 10% hamstring deficit. Post-operatively there was an 11% and 6.3% improvement in the hop tests, a 9% (P < 0.01) improvement in the shuttle run, a 15% (P < 0.001) improvement in the side step and a 24% (P < 0.001) improvement in the carioca tests (P < 0.001) despite the loss of muscle strength.

The effect of taping, quadriceps strengthening and stretching prescribed separately or combined on patellofemoral pain

BACKGROUND AND PURPOSE Quadriceps strengthening, quadriceps stretching and patellar taping are commonly prescribed together for patellofemoral pain patients. This study aimed to examine the effectiveness of each of these techniques in isolation for one week and in combination for one week. METHODS A prospective double-blind randomized control study was designed involving 41 subjects with 60 knees diagnosed with patellofemoral pain. The knees were randomized in onto one of four groups (n = 15): infrapatellar taping, quadriceps strengthening, quadriceps stretching and control. The taping was worn continually for the week; the strengthening group followed a programme of non-weight-bearing terminal range quadriceps exercises, the stretching group performed rectus femoris stretches. The control group did not receive treatment. All subjects received advice. Seven pre- and post-treatment measures included isokinetic quadriceps strength, quadriceps length, pain measured during four activities and maximum eccentric, posturally controlled, pain-free knee flexion angle during a step-down. Results showed significant changes over time (p < 0.01) in two out of seven measures for the taping group, in five out of seven for the strengthening group and five out of seven for the stretching group and none in the control group. When the three modalities were combined for one week, (n = 60) all seven measures improved significantly (p < 0.01). CONCLUSION In isolation, quadriceps stretching and quadriceps strengthening resulted in more improvements than taping. Combining these treatments is recommended as the initial approach to treating patellofemoral pain but further individualized more functional, global treatment is essential.

The effect of anterior cruciate ligament rupture on the timing and amplitude of gastrocnemius muscle activation: A study of alterations in EMG measures and their relationship to knee joint stability

Changes in hamstring and quadriceps activity are well known in individuals with anterior cruciate ligament deficiency (ACLD) to potentially compensate for knee joint instability. However, few studies have explored gastrocnemius activity or its relationship to knee stability. The purpose of this study was therefore to examine the activation characteristics of medial gastrocnemius (MG) in ACLD subjects and relate any changes to knee joint laxity. Two subject cohorts were assessed: those with unilateral ACLD (n=15) and uninjured control subjects (n=11). Surface EMG of the left and right MG were recorded during a controlled single leg hop on each limb. Onset and offset of MG activation relative to take-off, during flight and landing were calculated as well as muscle activity (RMS). Passive antero-posterior knee laxity was measured with a KT1000 arthrometer during a maximal manual displacement test. Medial gastrocnemius activity on the injured side of ACLD participants demonstrated significantly prolonged activation in preparation to hop, minimal muscle inactivity prior to take-off, and increased duration of overall muscle activity when compared to the uninjured side and control subjects (p<0.05). Significant positive correlations were found between passive knee joint laxity and prolonged activation prior to knee bend. RMS of the muscle signal was not significantly different between limbs. Overall, MG on the ACLD side demonstrated longer activation, with minimal rest during the hop test, which may be an attempt to maintain knee stability. Furthermore, the strong relationship between knee laxity and prolonged muscle activation suggests that individuals with a loss of knee stability are more reliant on active control of the gastrocnemius muscle.

Tibial displacement and rotation during seated knee extension and wall squatting: A comparative study of tibiofemoral kinematics between chronic unilateral anterior cruciate ligament deficient and healthy knees

BACKGROUND Following anterior cruciate ligament (ACL) rupture, the knee becomes unstable with alterations in joint kinematics including anterior tibial displacement (ATD), and internal tibial rotation. Therapeutic exercises that promote faulty kinematics should be discouraged, especially early post-reconstruction, to avoid graft stretching and possibly longer-term osteoarthritis. Our study aimed to compare ATD and tibial rotation during two commonly prescribed exercises, namely: open kinetic chain (OKC) seated extension and closed kinetic chain (CKC) single leg wall squatting in ACL-deficient and healthy knees. METHODS Eight ACL-deficient patients and eight healthy subjects matched for age, gender and sports history were assessed using Qualisys 3D-Motion Analysis System to track 17 infrared markers while performing a seated knee extension with 3kg weight and a unilateral wall squat. We developed a model to measure joint kinematics through 70° of knee flexion and extension. ANOVA and paired t-tests compared relative ATD and tibial rotation between exercises and groups at 10° increments of flexion and extension. RESULTS We found increased ATD in the wall squat compared to the seated extension (p=0.049). There was no difference in ATD between the healthy and ACL-deficient knees but overall the tibia was significantly more internally rotated (p=0.003) in ACL-deficient knees, irrespective of the exercise, possibly interfering with the screw-home mechanism. CONCLUSIONS CKC exercises, in particular wall squats, are not necessarily safer for patients with ACL-deficiency and possibly ACL-reconstruction; although generalization should only be made with appropriate caution. Clinicians require a detailed knowledge of the effect of exercise on knee joint kinematics.

Three-year outcome after a 1-month physiotherapy program of local and individualized global treatment for patellofemoral pain followed by self-management

Objective:The main aim of this study was to assess whether improvements after a 1-month patellofemoral pain (PFP) program addressing local and global deficits were maintained for 3 years. Design:This prospective cohort study comprised 4 treatment phases including a randomized trial during week 1. Setting:The study was conducted in a private physiotherapy practice. Patients:Thirty-seven patients (55 knees) from an original cohort of 41 patients (60 knees) with PFP were followed for 3 years after referral by doctors to participate in this study. Interventions:Patients received 4 treatments: local treatment focusing on quadriceps strengthening, quadriceps stretching, and taping for fortnight 1, supplemented with individualized global treatment focusing on lower limb posture and movement patterns for fortnight 2, followed by ongoing self-management. Main Outcome Measures:Seven outcome measures, assessed at 4 time points, were quadriceps strength, quadriceps length, eccentric knee control, and 4 pain measures. Long-term measures included return to sporting activity, pain recurrence, exercise compliance, and Kujala score. Results:Improvements after fortnight 1 (P < 0.001) and fortnight 2 (P < 0.05) were maintained over 3 years for 6 of 7 measures. On testing, 73% were pain free and the remaining 27% had less pain than pretreatment. Kujala scores improved 27%. Eighty-two percent resumed any sport stopped and 54% of patients started new sports/activities. Patellofemoral pain recurred in 7% and 89% of patients was still exercising 3 years posttreatment. Conclusions:Significant improvements after physiotherapy, incorporating local and individually targeted treatment, were maintained for 3 years in a compliant cohort.