Non-injured Leg Research Articles

Early detection of burn induced heterotopic ossification using transcutaneous Raman spectroscopy

IntroductionHeterotopic ossification (HO), or the abnormal formation of bone in soft tissue, occurs in over 60% of major burn injuries and blast traumas. A significant need exists to improve the current diagnostic modalities for HO which are inadequate to diagnose and intervene on HO at early time-points. Raman spectroscopy has been used in previous studies to report on changes in bone composition during bone development but has not yet been applied to burn induced HO. In this study, we validate transcutaneous, in-vivo Raman spectroscopy as a methodology for early diagnosis of HO in mice following a burn injury. MethodsAn Achilles tenotomy model was used to study HO formation. Following tenotomy, mice were divided into burn and sham groups with exposure of 30% surface area on the dorsum to 60° water or 30° water for 18s respectively. In-vivo, transcutaneous Raman spectroscopy was performed at early time points (5days, 2 and 3weeks) and a late time point (3months) on both the tenotomized and non-injured leg. These same samples were then dissected down to the bone and ex-vivo Raman measurements were performed on the excised tissue. Bone formation was verified with Micro CT and histology at corresponding time-points. ResultsOur Raman probe allowed non-invasive, transcutaneous evaluation of heterotopic bone formation. Raman data showed significantly increased bone mineral signaling in the tenotomy compared to control leg at 5days post injury, with the difference increasing over time whereas Micro CT did not demonstrate heterotopic bone until three weeks. Ex-vivo Raman measurements showed significant differences in the amount of HO in the burn compared to sham groups and also showed differences in the spectra of new, ectopic bone compared to pre-existing cortical bone. ConclusionsBurn injury increases the likelihood of developing HO when combined with traumatic injury. In our in-vivo mouse model, Raman spectroscopy allowed for detection of HO formation as early as 5days post injury. Changes in bone mineral and matrix composition of the new bone were also evidenced in the Raman spectra which could facilitate early identification of HO and allow more timely therapy decisions for HO patients.

Knee function and knee muscle strength in middle-aged patients with degenerative meniscal tears eligible for arthroscopic partial meniscectomy

BackgroundFunctional limitations exist postmeniscectomy, but preoperative data are scarce.PurposeTo examine knee function, knee muscle strength and performance in middle-aged patients with degenerative meniscal tears, eligible for arthroscopic partial meniscectomy.Study designCross-sectional...

Effects of tendon viscoelasticity in Achilles tendinosis on explosive performance and clinical severity in athletes

The aim was to compare viscoelastic properties of Achilles tendons between legs in elite athletes with unilateral tendinosis, and to investigate relationships between the properties and explosive performance and clinical severity. Seventeen male athletes (mean ± standard deviation age, 27.3 ± 2.0 years) who had unilateral, chronic middle-portion tendinopathy of the Achilles tendon were assessed by the Victorian Institute of Sport Assessment questionnaire, measurements of tendon viscoelastic properties, voluntary electromechanical delay (EMD), normalized rate of force development (RFD), and one-leg hopping distance. Compared with the non-injured leg, the tendinopathic leg showed reduced tendon stiffness (-19.2%. P < 0.001), greater mechanical hysteresis (+21.2%, P = 0.004), lower elastic energy storage and release (-14.2%, P = 0.002 and -19.1%, P < 0.001), lower normalized RFD at one-fourth (-16.3%, P = 0.02), 2/4 (-17.3%, P = 0.006), and three-fourths maximal voluntary contraction (-13.7%, P = 0.02), longer soleus and medial gastrocnemius voluntary EMD (+26.9%, P = 0.009 and +24.0%, P = 0.004), and shorter hopping distances (-34.1%, P < 0.001). Tendon stiffness was correlated with normalized RFD, voluntary EMD in the medial gastrocnemius, and hopping distances (r ranged from -0.35 to 0.64, P < 0.05). Hysteresis was correlated to the soleus voluntary EMD and hopping distances (r = 0.42 and -0.39, P < 0.05). We concluded that altered tendon viscoelastic properties in Achilles tendinosis affect explosive performance in athletes.

Functional pain measure in knee osteoarthitis - a proof of concept study on a novel method of assessing pain during function

s / Osteoarthritis and Cartilage 20 (2012) S54–S296 S162 stresses is reduced due to tissue removed. Impaired knee function, such as poor self-reported outcomes, muscle weakness and reduced functional performance is other suggested factors that may contribute to progression of knee OA. This study aimed to examine pre-operative knee function in middle-aged female and male patients with degenerative meniscus tears eligible for arthroscopic surgery, compared to a healthy population and the respective patient non-injured leg. Methods: 70 patients (36% females, age (mean SD) 49 6, BMI 27 3) with an MRI verified degenerative meniscal tear considered eligible for surgery were included. Outcomemeasures were the Knee injury and Osteoarthritis Outcome Score (KOOS), isokinetic knee extension and flexion muscle strength tests and three lower extremity performance tests; maximum number of kneebendings in 30s, the one leg hop for distance and the 6meter timed hop test. The performance tests are in addition to muscle strength also dependent on the ability to switch between concentric and eccentric muscle contraction, balance and functional stability, and for the hop tests confidence in the knee. Results: KOOS mean subscale scores ranged from 43 to 76. Mean score differences between the patients and an age matched population based reference group ranged from 13 to 38 (p1⁄4<0.000), Figure 1. There were no significant differences in KOOS scores between genders. The index leg was significantly weaker in isokinetic knee extension and flexion strength compared to the contralateral leg (155Nm 53 and 84Nm 27 vs. 179Nm 51 and 87Nm 24, p 0.03). Mean differences in peak torque and total work quadriceps muscle strength compared with the contralateral leg was 15% and 14% for the females and 13% and 9% for the males, respectively. For all three lower extremity performance tests the results of the index leg were significantly worse than for the contralateral leg (number of kneebendings 26 10 vs. 28 10, p1⁄4<0.001, one leg hop 82 35 vs. 92 31 cm p1⁄4<0.001, 6-meter timed hop test 3.0 1.4 vs. 2.5 0.8 s, p1⁄4<0.001). Mean differences in the three tests compared with the contralateral leg ranged from 12% to 14% for the females and 5% to 12% for the males. Conclusions: Patients with a degenerative meniscus tear considered eligible for surgery reported severely impaired pain, other symptoms, function in daily living and sports, and knee related quality of life compared to an age matched population based reference group. Muscle function in the index leg was significantly worse with up to 15% lower muscle function compared to the contralateral leg. These results suggest that risk factors for OA onset, other than intraarticular damage, are present in patients with a degenerative meniscus tear.

Gait analysis post anterior cruciate ligament reconstruction: Knee osteoarthritis perspective

Individuals with anterior cruciate ligament (ACL) reconstruction are at increased risk to develop knee osteoarthritis (OA). Gait analysis describing kinetics of the lower extremity during walking and stair use (stair ascent and stair descent) can provide insight to everyday dynamic knee joint loading. In this study, we compared lower extremity gait patterns of those with ACL reconstruction (>1 year) to a control group. Fifteen ACL reconstructed individuals and 17 healthy controls participated in this study. Knee extensor and flexor strength were assessed. Using inverse dynamics, lower extremity moments were calculated during the stance phase of walking and during two steps of stair ascent and descent. Univariate ANOVA was used to test for main effects between (1) injured leg and control group and (2) non-injured leg and control group. Student paired t-tests were used to determine differences between the injured and non-injured leg. Those with ACL reconstruction exhibited reduced initial knee flexion angles during stair descent, reduced knee extension moments during stair descent and stair ascent (second step), and increased hip extension moments during stair ascent (second step) and walking as compared to controls. Knee flexor strength was significantly reduced in the ACL group, but no differences were found in knee extensor strength. No kinematic or kinetic differences were observed between the injured and non-injured leg of the ACL group. Walking and stair ambulation highlight altered joint loading in those with ACL reconstruction surgery. Individuals appeared to compensate for lower knee extension moments by increasing hip extension moments. Furthermore, the load distribution on the articular cartilage is likely shifted as evidenced by reduced knee flexion angles in the ACL reconstructed leg.

Effect of an accelerated ACL rehabilitation protocol on knee proprioception and muscle strength after anterior cruciate ligament reconstruction

Objective: to evaluate knee joint position sense (JPS) and muscle strength following an accelerate rehabilitation protocol after ACL reconstruction and compare it with the contralateral non-injured leg, and with an age-matched non-injured control group. Design : Seven subjects (mean age: 26.6 ± 4.8 years) submitted to ACL reconstruction (ACL group) using a patellar tendon auto-graft (bone-tendon-bone) and nine healthy individuals (mean age: 26.8 ± 3.8 years) participated in this cross-sectional study. Joint position sense was evaluated using the technique of open-kinetic chain and active knee positioning. Knee extensors and flexors muscle strength was evaluated in an isokinetic dynamometer at 180o/s (3.14 rad.s -1 ) and 60o/s (1.05 rad.s -1 ). Results: The ACL reconstruction group showed better knee JPS in the uninjured knee than in the reconstructed knee in absolute (2.17o ± 2.69o vs. 5.98o ± 2.64o, p<0.05), relative (2.17o ± 2.69o vs. 5.98o ± 2.64o, p<0.05), and variable angular errors (2.38 ± 1.15o vs. 2.01 ± 1.64, p<0.05). The reconstructed knee also exhibited inferior JPS than both limbs of the control group. No significant differences in quadriceps and hamstrings muscle strength were observed. Significant contralateral differences between ACL and control group were found for knee extensors at 60o/s (33.6 ± 18.0 vs. 5.9 ± 7.1%, p<0.05) and 80o/s (20.2 ± 13.5 vs. 5.8 ± 3.9%, p<0.05), and knee flexors at 60o/s (16.2 ± 6.4 vs. 8.5 ± 5.0%, p<0.05). Conclusions: Our findings indicate that joint position sense and muscle function is still impaired after an accelerate rehabilitation protocol for ACL reconstruction surgery suggesting that these individuals are still predispose to further muscle or proprioceptive related knee injury.

Inflammatory and Protein Metabolism Signaling Responses in Human Skeletal Muscle After Burn Injury

Severe burn injuries lead to a prolonged hypercatabolic state resulting in dramatic loss of skeletal muscle mass. Postburn muscle loss is well documented but the molecular signaling cascade preceding atrophy is not. The purpose of this study is to determine the response to burn injury of signaling pathways driving muscle inflammation and protein metabolism. Muscle biopsies were collected in the early flow phase after burn injury from the vastus lateralis of a noninjured leg in patients with 20 to 60% TBSA burns and compared with uninjured, matched controls. Circulating levels of proinflammatory cytokines were also compared. Immunoblotting was performed to determine the protein levels of key signaling components for translation initiation, proteolysis, and tumor necrosis factor/nuclear factor kappa B (NFκB)and interleukin (IL)-6/STAT3 signaling. Burn subjects had significantly higher levels of circulating proinflammatory cytokines, with no difference in muscle STAT3 activity and lower NFκB activity. No differences were found in any translational signaling components. Regarding proteolytic signaling in burn, calpain-2 was 47% higher, calpastatin tended to be lower, and total ubiquitination was substantially higher. Surprisingly, a systemic proinflammatory response 3 to 10 days postburn did not lead to elevated muscle STAT3 or NFκB signaling. Signaling molecules governing translation initiation were unaffected, whereas indices of calcium-mediated proteolysis and ubiquitin-proteasome activity were upregulated. These novel findings are the first in humans to suggest that the net catabolic effect of burn injury in skeletal muscle (ie, atrophy) may be mediated, at least during the early flow phase, almost entirely by an increased proteolytic activity in the absence of suppressed protein synthesis signaling.

Patient-reported and Functional Outcomes of Bicondylar Tibial Plateau Fractures Managed by Internal Screw Fixation in Combination with An Ilizarov Fixator: A Case Series of 22 Patients with Long-term Follow-up.

ABSTRACTIntroductionThe objective of this case series was to report the long-term patient-reported and functional outcomes of complex bicondylar tibial plateau fractures in patients treated with internal fixation in combination with an Ilizarov fixator.Materials and methodsA retrospective series of cases. Patient-reported, radiological and functional outcomes were obtained with a mean of 9.4 years’ follow-up.ResultsTwenty-two patients completed the follow-up. At follow-up, the mean age was 52.2 years, ranging from 26 to 69 years. The gender distribution was 14 males and 8 females. The mean knee injury and osteoarthritis outcome score (KOOS) was pain 72.5, symptoms 62.7, ADL 75.9, sport 35.4, and knee related quality of life (QOL) 56.4. Compared to a reference population, the present study reported worse outcome for the subscales: symptoms, sport, and QOL. The maximal isometric muscle strength for knee extension was 354N for the noninjured leg and 325N for the injured leg (p = 0.27). Assessment of gait functions showed a gait speed of 122.7 cm/second and a cadence of 112.7 steps/minute. Gait speed and cadence showed no significant difference when compared to a reference population. Radiological examination of knee osteoarthritis (OA) showed 6 patients presented with none OA, 13 patients with mild OA, and 3 patients with severe OA.ConclusionComplex bicondylar tibial plateau fractures are associated with long-term decreased knee structure-specific patient-reported outcome (KOOS). In contrast, most patients presented with satisfactory long-term radiological and functional outcomes. More research is needed to understand the complex association between patient-reported outcomes and radiological and functional outcomes.Level of evidenceIV. Series of cases.How to cite this articleLarsen P, Traerup J, Mikuzis M, et al. Patient-reported and Functional Outcomes of Bicondylar Tibial Plateau Fractures Managed by Internal Screw Fixation in Combination with An Ilizarov Fixator: A Case Series of 22 Patients with Long-term Follow-up. Strategies Trauma Limb Reconstr 2019;14(2):85–91.

Ultrasound biomicroscopy for biomechanical characterization of healthy and injured triceps surae of rats

This work describes the use of ultrasound biomicroscopy (UBM) to follow up the degeneration-regeneration process after a laceration injury induced in the lateral gastrocnemius (LG) and soleus (SOL) muscles of rats. UBM (40 MHz) images were acquired and used for biomechanical characterization of muscular tissue, specifically using pennation angle (PA) and muscle thickness (MT). The animals were distributed in three groups: the variability group (VG; N=5), the gastrocnemius injured group (GG; N=6) and the soleus injured group (SG; N=5). VG rats were used to assess data variability and reliability (coefficients of variation of 9.37 and 3.97% for PA and MT, respectively). GG and SG rats were submitted to the injury protocol in the LG and SOL muscles of the right legs, respectively. UBM images of muscles of both legs were acquired at the following time points: before and after injury (immediately, 7, 14, 21 and 28 days). We observed an increase in PA for the non-injured leg 28 days after injury for both GG and SG rats (GG=10.68 to 16.53 deg and SG=9.65 to 14.06 deg; P<0.05). Additionally, MT presented a tendency to increase (GG=2.92 to 3.13 mm and SG=2.12 to 2.35 mm). Injured legs maintained pre-injury PA and MT values. It is suggested that a compensatory hypertrophic response due to the overload condition imposed to healthy leg. The results indicate that UBM allows qualitative and quantitative muscle differentiation among healthy and injured muscle at different stages after lesion.

Assessment of Muscular Performance in Teenagers After a Lower Extremity Fracture

Deleterious effects of lower limb immobilization in adults have been well described and suggest that altered muscle strength was not fully recoverable after rehabilitation. In this study, we hypothesized that the same significant differences in strength and power performances between the injured and noninjured leg are foreseeable 18 months after a lower limb fracture in teenagers, and between injured adolescents and healthy controls. The effects of cast immobilization on the strength and power performance were evaluated 18 months after a lower limb fracture in 39 injured teenagers who were paired with healthy controls. Strength and power performance were assessed during a single-leg vertical jump test using a force platform. At 18 months, strength performance in injured teenagers was similar in both lower limbs. A significant difference was found between injured and noninjured legs for maximal muscular power measurement. However, the limb symmetry index was superior to 85% for maximal muscular power, which should be considered as normal. Limb asymmetries greater than 15% for muscular strength and power were more frequent in injured teenagers than in noninjured children and adolescents, but the difference was statistically significant only for the mean muscle power (P=0.0003). These findings show that the recovery of muscular strength and power is foreseeable after a lower limb fracture in the pediatric population, even if a greater percentage of injured teenagers was found to have limb asymmetries greater than 15% for mean muscular power 18 months after trauma compared with the healthy controls. Level III, case-control study.

Contralateral Leg Deficits in Kinetic and Kinematic Variables During Running in Australian Rules Football Players With Previous Hamstring Injuries

Contralateral leg deficits between lower limbs during athletic movements are thought to increase the risk of injury and compromise performance. The purpose of this study was to quantify the magnitude of leg deficits during running in noninjured and previously injured Australian Rules football (ARF) players. The players included a group of noninjured ARF players (n = 11) and a group of previously injured ARF players (n = 11; hamstring injuries only). The players in the injured group (IG) had at least 1 acute hamstring injury in the previous 2 years. The legs of the noninjured players (NIG) were classified as right and left, whereas the legs of the injured players were classified as injured or noninjured. The players ran on a nonmotorized force treadmill at approximately 80% of their maximum velocity (Vmax). For the NIG, there were no significant differences between right and left legs for any of the variables. For the IG, the only variable that was significantly (p < 0.001) different between the injured and noninjured leg was horizontal force (175 +/- 30 vs. 326 +/- 44 N). Furthermore, horizontal force was significantly greater in the noninjured leg (IG) in comparison with either legs in the NIG (19.2% and 20.5%) and significantly less in the injured leg (IG) in comparison with either legs of the NIG (31.5% and 32.7%). In the present study, athletes with previous hamstring injuries had contralateral leg deficits in horizontal but not vertical force during running at submaximal velocities.

ACL Research Retreat V

ACL Research Retreat V

Intensive Training In The Early Phase After Acl Injury May Restore Quadriceps Strength Symmetry

Quadriceps muscle strength after anterior cruciate ligament (ACL) injury has been shown to correlate strongly with knee function during activity. Hence, to regain sufficient quadriceps muscle strength is crucial in early ACL rehabilitation. There is, however, no consensus on what is the optimal rehabilitation regime in this regard. PURPOSE: The aim of the present study was to examine quadriceps strength development in newly injured ACL deficient subjects following an intensive strength training protocol. METHODS: Seventy-five individuals with average age of 25.6 (range 14-47) years with unilateral isolated ACL rupture were included in the study. Baseline quadriceps performance was tested using isokinetic muscle strength tests (Biodex 6000) at 5 reps/60° per second as soon as range of motion insufficiency and swollenness was elucidated. Subjects completed a protocol with open and closed kinetic chain exercises in three series of six to eight repetitions, 12-15 sessions during maximum five weeks, before retest. Outcome measurements were peak torque (PT) and total work (TW). RESULTS: At baseline, there were significant differences between injured and non-injured leg for both PT and TW (p<0.01). At retest, quadriceps muscle strength had improved significantly (p<0.01) on the injured leg compared to the uninjured leg, with an average improvement of 9.4% (PT) and 10.5% (TW). Retest values on the injured leg were equivalent to baseline values on the non-injured leg both for PT and TW. This may be indicative of strength improvements on the injured leg that match pre-injury strength levels. Only three of the subjects experienced complications that led to inadequate compliance to the protocol. CONCLUSION: Re-establishing sufficient quadriceps strength may contribute to quicker restoration of knee function. This study indicated that an intensive strength training protocol in the early phase of rehabilitation after ACL injury is well tolerated and leads to considerable improvements in quadriceps performance. For non-operative candidates this may facilitate return to previous activities, whereas candidates for surgery may preclude severe postoperative deficits through maximizing their preoperative performance. Supported by NIH grant 2 RO1 HD 037985-05.

Application of eccentric exercise on an Australian Rules football player with recurrent hamstring injuries

Study Design Case report. Objective To assess an eccentric based intervention on an Australian Football player with recurrent hamstring injuries. Case description The athlete attempted several conventional rehabilitation programs in the past (e.g. physical therapy, manual therapy, acupuncture, active release, medial gluteal strengthening) with no sustained progress in regards to pain, soreness, or return to sport. Outcomes After the first three phases of the intervention (i.e. nine weeks), the optimum angle of peak torque during knee flexion decreased from 37.3 to 23.9 degrees in the injured leg, and from 24.3 to 20.3 degrees in the non-injured leg. After the first nine weeks, the optimum angles then remained constant for another 23 weeks. The optimum angle of peak torque was also shifted in the knee extensors by 3.9 degrees (injured leg) and 3.4 degrees (non-injured leg) after nine weeks and then remained constant for the remaining 23 weeks. Quadriceps to hamstring peak torque ratio's (Q/H ratios) and peak torque during knee flexion and extension remained constant throughout the intervention. Discussion An eccentric based intervention was shown to be safe and effective for altering the optimum angle of peak torque (i.e. shifting to longer muscle lengths) for this athlete with recurrent hamstring injuries.

8주간 등속성운동이 여성 전방십자인대 상해환자의 무릎관절 회전력에 미치는 영향

The purpose of this study was to examine the effect of 8weeks isokinetic exercise on torque variables of knee joint in anterior cruciate ligament patient women. The subjects of the study were 8 female attached who registered patient at muscular-joint function clinic of the H hospital. The group were divided into two group; the experimental group as injured side leg and control group as non-injured side leg. Isokinetic knee joint exercise employed Kin-Com (U.S.A) to measure peak torque(PT), PT%BW, average power, average%BW, and recover ratio. The results of this study were follows; After 8weeks of 60°/sec exercise in PT, PT%BW were significantly increased in non-injured side leg group(p.05) and it was in flexion then in extension recovery ratio(p.05). After 8weeks of 180°/sec exercise in average, average%BW were significantly increased in non-injured side leg group(p.05) and it was in flexion then in extension recovery ratio(p.05). When PT-angle in 30°/sec load of pre operation becomes smaller it can correlation in flexion PT%BW, average power%BW, these were not correlation in extension(p.01).

Operative Treatment of Acute Achilles Tendon Rupture: Open End-to-End-Reconstruction Versus Reconstruction with Mitek-Anchors

Purpose: To retrospectively compare the open end-to-end repair versus repair using the Mitek-anchor system in acute Achilles tendon rupture.Method: Forty-seven consecutive patients with Achilles tendon rupture, all operated on between 2004 and 2005, were included. Their medical records were reviewed and they were interviewed for surveillance of post-operative function at follow-up. Functional outcome was determined using an adapted VISA tendinopathy questionnaire and by testing the isometric ankle plantar flexion strength. Post-operative complications and recurrence rate of rupture were noted. Results: Seven patients were lost to follow-up. From a total of 40 patients, twenty-eight (68% of total) underwent classic repair and 12 (32%) were treated by the Mitek-anchor system. Median age was 43 years (range 29–63). Median post-operative follow-up was 29 months (range 17–40). Median time to resume work was nine weeks in the classic group versus 12 weeks in the Mitek-group. Median time to resume sports was 19 versus 31 weeks respectively. Wound infections occurred in five percent of the total (one in each group) and rupture recurrence rate was three percent of the total (nil in classic group, one in Mitek-group). Loss of strength in the injured leg compared to the non-injured leg was greater in the Mitek-group than in the classic group.Conclusion: We conclude that in comparing classical end-to-end repair of acute Achilles tendon ruptures with repair using Mitek-anchors, it took patients in the Mitek-group longer to return to work and sport activities than in the classic group. Greater loss of strength in the injured leg was seen in the Mitek-group. Therefore we do not advocate the use of Mitek-anchors for the repair of acute ruptured Achilles tendons.

Changes in knee motion pattern after anterior cruciate ligament injury – A case report

After an anterior cruciate ligament injury, the contra-lateral non-injured leg has been found to adapt towards the injured leg. Accordingly, in order to study changes in knee motion pattern after an anterior cruciate ligament injury, the ideal is to compare the same leg prior to and after the injury. However, this is very seldom possible. The purpose of the present study was to describe changes in static and dynamic sagittal tibial translation, electromyographic activity and muscle torque relevant to an anterior cruciate ligament tear in one patient evaluated both before and after the injury. A male soccer player was examined 11 weeks before and eight weeks after an anterior cruciate ligament injury. Sagittal tibial translation was measured with the CA-4000 electrogoniometer; statically during Lachman's test, and dynamically during isokinetic muscle testing, one-legged squat and level walking. The electromyographic activity of mm. quadriceps and hamstrings, was registered simultaneously during the one-legged squat test. Static tibial translation was increased by approximately 2 mm, while dynamic tibial translation was decreased by 0.4 mm at isokinetic testing, 0.9 mm at one-legged squat and 2.4 mm during level walking compared to before the injury. Muscle torque decreased 30% and 35% for the quadriceps and the hamstrings muscle, respectively. The electromyographic activity revealed similar activation levels in quadriceps and a doubled level of activation in hamstring compared to before the injury. In spite of an increase in static tibial translation eight weeks after an anterior cruciate ligament injury, the tibial translation decreased during activity, thus indicating that the patient could stiffen the knee in order to protect it against increased shear forces.

Muscle strength and jumping distance during 10 years post ACL reconstruction

The aim of this study was to analyze long-term changes in muscle strength and jumping ability and to assess the relationship between these parameters after anterior cruciate ligament (ACL) reconstruction. Sixty-three patients (39 men) with a mean age of 30.3 years (range 19-42) who underwent an ACL reconstruction between 1990-1992 participated in the study. Quadriceps and hamstring isometric and isokinetic strength as well as one-leg hop test for distance were measured preoperatively and six months 1, 2, 3 and 10 years postoperatively. The injured leg was significantly weaker than the non-injured leg in knee extension strength on all test occasions and in knee flexion strength except at ten years. There was a strong correlation between the muscle strength tests at different speeds. The one leg hop for distance showed significant differences between the injured and non-injured leg on all test occasions. A moderate to high correlation was observed between muscle strength and jumping ability with higher values for the non-injured leg. In our study we found a persisting weakness in the quadriceps as well as jumping ability during ten years. This is an indication that it is hard to recover the preoperative functional level after an ACL reconstruction.

Quadriceps and patellar tendon rupture

Ruptures of the patellar and/or quadriceps tendon are rare injuries that require immediate repair to re-establish knee extensor continuity and to allow early motion. We evaluated 36 consecutive patients with quadriceps or patellar tendon rupture between 1993 and 2000. There were 37 primary ruptures, 3 reruptures, 21 quadriceps and 19 patellar tendon ruptures. Follow up examination (>24 months postoperatively) included the patient's history, assessment of risk factors, clinical examination of both knees, isometric muscle strength measurements and three specific knee scores, Hospital for Special Surgery Score, Knee Society Score and Turba Score, and a short form SF-36. We evaluated 29 patients (26 men) with 33 ruptures (16 patellar tendon, 17 quadriceps tendon). Seven patients were lost to follow up. We found no difference between the range of motion and muscle strength when the injured leg was compared to the non-injured leg. Risk factors did not influence the four scores, patient satisfaction, pain, muscle strength or range of motion. Multiple injured patients had a significant reduction in muscle strength and circumference, however patient satisfaction did not differ to the non-multiple injured patient group.

Long-term Evaluation Of Muscle Strength And Jumping Ability After Anterior Cruciate Ligament Reconstruction

There are a large number of studies assessing muscle strength and function after ACL reconstruction. Short-term follow-up, up to two years after the reconstruction is common. On the other hand few studies extend over a time of ten years. PURPOSE To analyse long-term changes in muscle strength, jumping ability and quality of life and to assess the relationship between the performance based tests after anterior cruciate ligament (ACL) reconstruction. METHODS Sixty-three patients, 39 men and 24 women, with a mean age of 30,3 years (range 19–42), who underwent an ACL reconstruction 1990–1992 participated. The patients were examined with isometric and isokinetic muscle strength tests and one-leg hop test for distance preoperatively and six months, 1, 2, 3 and ten years postoperatively. Qaulity of life was assessed with the KOOS at ten years postoperatively. RESULTS Significant differences in knee extension were seen between the injuried and the non-injured leg on all test occassions. Regarding knee flexion significant differences were seen except at ten years. There was a strong correlation between the muscle strength tests at different speeds on all test occassions for both knee extension and knee flexion. One-leg hop test for distance improved significantly up to two years postoperatively with significant differences between legs up to three years. The correlation between muscle strength and jumping ability was higher in the non-injured leg than in the injured leg. CONCLUSIONS In the present study we found a persisting weakness in the quadriceps muscle during the ten years follow-up. Patients seem to have difficulties to regain the same functional level as preoperatively. A moderate to high correlation was seen between muscle strength and jumping ability, which indicates the importance of performance based tests.