Achilles Tendon Complex Research Articles

The Effect of Anesthesia on Passive Ankle Dorsiflexion.

Equinus contractures can commonly be due to contractures of gastrocnemius muscle or combined contractures of the gastrocnemius-soleus Achilles tendon complex. The decision to release part or all of the gastrocnemius-soleus Achilles tendon complex is often assessed intraoperatively while the patient is under anesthesia. It remains unknown whether the administration of general anesthesia affects the measurement of passive ankle dorsiflexion. The unaffected, nonoperative limb on 46 foot and ankle patients underwent a Silfverskiold test measuring passive ankle dorsiflexion preoperatively and intraoperatively after administration of general anesthesia using an instrumented force-angular displacement goniometer. To determine clinical significance, we surveyed experienced surgeons to estimate the perceived minimally detectable clinical accuracy for measuring passive ankle dorsiflexion. Forty-six subjects were included with mean age of 42 ± 14.8 years, mean body mass index of 26.2 ± 4.9, and 52% female. The mean change in dorsiflexion values from before anesthesia to after the administration of general anesthesia was 1.9 degrees with 10 lb of pressure with knee extended (E10), 2.3 degrees with 20 lb of pressure with knee extended (E20), 2.8 degrees with 10 lb of pressure with knee flexed (F10), and 2.3 degrees with 20 lb of pressure with knee flexed (F20) (all P < .001). Thirty-three of 45 (73%) surgeons responded to the survey; all thought their minimally detectable clinical accuracy was 5 degrees or greater. After the administration of general anesthesia, a small but likely not clinically detectable increase in passive ankle dorsiflexion occurs. The common clinical practice of making intraoperative treatment decisions regarding the presence of a gastrocnemius-soleus driven equinus contractures after general anesthesia without use of paralytic agents appears reasonable given the magnitude of the changes identified in this study.

Biomechanical changes in the gastrocnemius medius-Achilles tendon complex in people with hypermobility spectrum disorders: A cross-sectional compression sonoelastography study.

This study aimed to assess the biomechanical impact of Hypermobility Spectrum Disorders (HSD) on the elasticity of the gastrocnemius medius-Achilles tendon (GM-AT) complex. Using a cross-sectional design, the GM-AT complex elasticity was compared using sonoelastography (SEG) in an HSD group and healthy controls during rest and maximal isometric plantar flexion contraction. The HSD group comprised 28 patients (26 women); mean ± SD age 28.7 ± 8.4 years, compared to 28 controls (26 women); 31.5 ± 8.7 years. During rest, greater elasticity was identified in HSD relative to controls at the GM-AT musculotendinous junction (strain ratio 2.05 ± 1.31 vs. 1.48 ± 0.49), mid-AT (3.60 ± 1.97 vs. 2.66 ± 1.00), and distal AT (4.57 ± 2.69 vs. 3.22 ± 1.94) (all p < 0.05). During contraction, no significant differences were found between groups at the GM-AT musculotendinous junction (3.40 ± 2.16 vs. 2.62 ± 1.07), mid AT (10.75 ± 5.29 vs. 8.49 ± 3.53), or distal AT (8.55 ± 5.39 vs. 8.83 ± 3.51) (all p > 0.05). No significant differences were found between groups in the GM strain ratio during rest (4.05 ± 1.43 vs. 3.62 ± 0.78), or contraction (4.23 ± 1.29 vs. 4.19 ± 1.31). Exploratory Receiver Operator Characteristics curve analysis suggested low sensitivity and specificity of the strain ratio for the diagnosis of HSD. People with HSD have greater GM-AT complex elasticity. Although statistically significant group differences were identified, further research is required to establish the diagnostic, clinical, and research utility of strain ratio measurements.

The effect of combined action observation therapy and eccentric exercises in the treatment of mid-portion Achilles tendinopathy: study protocol for a feasibility pilot randomised controlled trial

BackgroundMid-portion Achilles tendinopathy (AT) is a common overuse injury which can be difficult to successfully rehabilitate. Whilst peripherally directed treatment approaches that strengthen the Achilles tendon complex can be efficacious for some individuals, others will continue to experience long-standing pain and functional deficits. Expanding our rehabilitation approach beyond the tendon mechanical properties to include techniques which target the central neurophysiological changes which can occur in chronic injuries, including mid-portion AT, may improve our rehabilitation outcomes. Action observation therapy (AOT) is one such technique which targets central changes and can enhance motor learning. To our knowledge, there is currently no available information on the combined effect of AOT and eccentric exercises in the rehabilitation of mid-portion AT, nor understanding of the feasibility of conducting randomised controlled trials that investigate this combined centrally and peripherally directed treatment approach. This protocol outlines the design of a remotely conducted parallel-group randomised controlled trial comparing the efficacy of combined AOT and eccentric loading exercises versus eccentric loading exercises alone for mid-portion AT.MethodsParticipants recruited throughout Ireland with mid-portion AT will be randomly assigned to one of the following groups: (i) The AOT group will observe videos of the eccentric exercises prior to the physical performance of the eccentric exercises. (ii) The control group will observe videos of landscapes prior to the performance of the eccentric exercises. This is a 12-week daily intervention as per the Alfredson loading protocol and outcome measures will be assessed at baseline, week 6 and week 12. Primary feasibility outcomes will include data on numbers of eligible participants, recruitment and retention rates, along with exercise compliance and acceptability of treatment. The primary clinical outcome measure will be the Victorian Institution Symptom Assessment-Achilles Questionnaire (VISA-A) assessing disability. Secondary clinical outcomes will address the remaining core domains as outlined by the International Scientific Tendinopathy Symposium consensus (ICON group) including pain, participation, functional, physical function capacity, quality of life and psychological factors. Widespread bodily pain and centralised pain features and patient satisfaction levels will also be evaluated.DiscussionThis study will provide scientific direction for future randomised controlled trials exploring the effect of AOT and eccentric exercises in the treatment of mid-portion AT on pain, centralised pain features, motor and non-motor functions, quality of life and patient satisfaction levels. The feasibility of the conducting a study remotely from participant screening to final follow-up assessment will also be provided.Trial registrationISRCTN58161116

Biomechanical Changes in the Gastrocnemius Medius–Achilles Tendon Complex in People with Hypermobility Spectrum Disorders: A Compression Sonoelastography Study

Biomechanical Changes in the Gastrocnemius Medius–Achilles Tendon Complex in People with Hypermobility Spectrum Disorders: A Compression Sonoelastography Study

The equine navicular apparatus as a premier enthesis organ: Functional implications.

Navicular syndrome has been traditionally characterized by progressive lameness with chronic degeneration of the navicular bone. Advances in imaging techniques have revealed that its associated soft tissue structures are also affected. This distribution of lesions is explained by conceptualizing the equine navicular apparatus as an enthesis organ that facilitates the dissemination of mechanical stress throughout the tissues of the foot. The navicular apparatus has the same structural adaptations to mechanical stress as the human Achilles tendon complex. These adaptations efficiently dissipate mechanical force away from the tendon's bony attachment site, thereby protecting it from failure. The comparison of these two anatomically distinct structural systems demonstrates their similar adaptations to mechanical forces, and illustrates that important functional insights can be gained from studying anatomic convergences and cross‐species comparisons of function. Such a functional conceptualization of the equine navicular apparatus resolves confusion about the diagnosis of navicular syndrome and offers insights for the development of mechanically based therapies. Through comparison with the human Achilles complex, this review (1) re‐conceptualizes the equine navicular apparatus as an enthesis organ in which mechanical forces are distributed throughout the structures of the organ; (2) describes the relationship between failure of the navicular enthesis organ and lesions of navicular syndrome; (3) considers the therapeutic implications of navicular enthesis organ degeneration as a form of chronic osteoarthritis; and based upon these implications (4) proposes a focus on whole body posture/motion for the development of prehabilitative and rehabilitative therapies similar to those that have already proven effective in humans.

Stiffness of the Gastrocnemius-Achilles Tendon Complex Between Amateur Basketball Players and the Non-athletic General Population.

Muscle and tendon stiffness are related to sports performance, tendinopathy, and tendon degeneration. However, the effects of habitual loading on muscle and tendon mechanical properties are unclear. Using amateur basketball players as examples, we investigated the effects of mechanical loading on the stiffness of the gastrocnemius–Achilles tendon (AT) complex in non-dominant and dominant lower limbs. Then, we evaluated the correlation between gastrocnemius and AT stiffness. Forty participants (20 amateur basketball players; 20 normal non-athletic persons) were recruited for this study. Stiffness of the gastrocnemius–AT complex was assessed using MyotonPRO at neutral position and 10° dorsiflexion of the ankle joint in participants from amateur basketball players and the non-athletic general population. Our results showed a greater stiffness of the gastrocnemius–AT complex in amateur basketball players than that in healthy non-athletic subjects at neutral position and 10° dorsiflexion of the ankle joint (P < 0.05). No significant difference in stiffness was found between the non-dominant and dominant lower limbs either in amateur basketball players or in generally healthy subjects (P > 0.05). A significant positive correlation was obtained between stiffness of the AT and medial gastrocnemius (MG) in amateur basketball players (neutral position: r = 0.726 and P = 0.001; dorsiflexion 10°: r = 0.687 and P = 0.001). The amateur basketball players exhibit significantly higher stiffness value in Achilles and gastrocnemius. This is possibly caused by repeated training effects. The symmetric stiffness of the AT and gastrocnemius exists both in amateur basketball players and generally healthy subjects. A significant correlation between the AT and the MG was found in amateur basketball players.

Comparison of the sonographic features of the Achilles Tendon complex in patients with and without achilles tendinopathy: A case-control study

AimThe aim of the present study was to evaluate and quantify with ultrasound imaging (USI) the Achilles tendon thickness, cross-sectional area (CSA), Kager's fat pad length and gastrocnemius-soleus pennation angle (PA) between chronic mid-portion Achilles tendinopathy (AT) and healthy subjects. MethodsA total sample of 143 individuals (age: 41.3 ± 12.0 y; height: 1.74 ± 0.0 m; weight: 75.0 ± 11.4 kg; body mass index, BMI: 24.4 ± 2.6 kg/m2) was recruited and divided in two groups: chronic mid-portion AT group (n = 71) and a healthy group (n = 72). ResultsThe thickness and CSA at 4 cm and 6 cm from the calcaneus was increased showing statistically significant differences (P < .01) in favor the tendinopathy group. For the gastrocnemius-soleus PA and Kager's fat pad length, significant differences (P < .01) were observed for a decrease in favor of the tendinopathy group. ConclusionsThis study reported an increase of Achilles tendon thickness and CSA at 4 cm and 6 cm from the calcaneus as well as a decrease in gastrocnemius-soleus PA and Kager's fat pad length in patients with chronic mid-portion AT.

Assessment and treatment of spastic equinovarus foot after stroke: Guidance from the Mont-Godinne interdisciplinary group.

To present interdisciplinary practical guidance for the assessment and treatment of spastic equinovarus foot after stroke. Clinical examination and diagnostic nerve block with anaesthetics determine the relative role of the factors leading to spastic equinovarus foot after stroke: calf spasticity, triceps surae - Achilles tendon complex shortening and dorsiflexor muscles weakness and/or imbalance. Diagnostic nerve block is a mandatory step in determining the cause(s) of, and the most appropriate treatment(s) for, spastic equinovarus foot. Based on interdisciplinary discussion, and according to a patient-oriented goal approach, a medical and/or surgical treatment plan is proposed in association with a rehabilitation programme. Spasticity is treated with botulinum toxin or phenol-alcohol chemodenervation and neurotomy, shortening is treated by stretching and muscle-tendon lengthening, and weakness is treated by ankle-foot orthosis, functional electrical stimulation and tendon transfer. These treatments are frequently combined. Based on 20 years of interdisciplinary expertise of management of the spastic foot, guidance was established to clarify a complex problem in order to help clinicians treat spastic equinovarus foot. This work should be the first step in a more global international consensus.

Influence of repetitive mechanical loading on MMP2 activity in tendon fibroblasts.

Matrix metalloproteinase2 has been implicated in tendon pathology caused by repetitive movements. However, its activity in the early stages of the tendon's response to overuse, and its presence in the circulation as a possible indicator of tendon degradation, remain unknown. Human tendon cells were repetitively stretched for 5 days, and the rabbit Achilles tendon complex underwent repetitive motion 3× per week for 2 weeks. Quantitative polymer chain reaction analysis was performed to detect matrix metalloproteinase2/14 and tissue inhibitor of matrix metalloproteinase2 messenger ribonucleic acid of cells and rabbit tissue, and matrix metalloproteinase2 protein levels were determined with an enzyme linked immunoassay. Matrix metalloproteinase2 activity was examined using zymography of the conditioned media, tendon and serum. Immunohistochemistry was used to localize matrix metalloproteinase2 in tendon tissue, and the density of fibrillar collagen in tendons was examined using second harmonic generation microscopy. Tendon cells stretched with high strain or high frequency demonstrated increased matrix metalloproteinase2 messenger ribonucleic acid and protein levels. Matrix metalloproteinase2 activity was increased in the rabbit Achilles tendon tissue at weeks 1 and 2; however, serum activity was only increased at week 1. After 2 weeks of exercise, the collagen density was lower in specific regions of the exercised rabbit Achilles tendon complex. Matrix metalloproteinase2 expression in exercised rabbit Achilles tendons was detected surrounding tendon fibroblasts. Repetitive mechanical stimulation of tendon cells results in a small increase in matrix metalloproteinase2 levels, but it appears unlikely that serum matrix metalloproteinase2 will be a useful indicator of tendon overuse injury. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1991-2000, 2016.

Regional molecular and cellular differences in the female rabbit Achilles tendon complex: potential implications for understanding responses to loading

The aim of this study was: (i) to analyze the morphology and expression of extracellular matrix genes in six different regions of the Achilles tendon complex of intact normal rabbits; and (ii) to assess the effect of ovariohysterectomy (OVH) on the regional expression of these genes. Female New Zealand White rabbits were separated into two groups: (i) intact normal rabbits (n = 4); and (ii) OVH rabbits (n = 8). For each rabbit, the Achilles tendon complex was dissected into six regions: distal gastrocnemius (DG); distal flexor digitorum superficialis; proximal lateral gastrocnemius (PLG); proximal medial gastrocnemius; proximal flexor digitorum superficialis; and paratenon. For each of the regions, hematoxylin and eosin staining was performed for histological evaluation of intact normal rabbit tissues and mRNA levels for proteoglycans, collagens and genes associated with collagen regulation were assessed by real-time reverse transcription-quantitative polymerase chain reaction for both the intact normal and OVH rabbit tissues. The distal regions displayed a more fibrocartilaginous phenotype. For intact normal rabbits, aggrecan mRNA expression was higher in the distal regions of the Achilles tendon complex compared with the proximal regions. Collagen Type I and matrix metalloproteinase-2 expression levels were increased in the PLG compared to the DG in the intact normal rabbit tissues. The tendons from OVH rabbits had lower gene expressions for the proteoglycans aggrecan, biglycan, decorin and versican compared with the intact normal rabbits, although the regional differences of increased aggrecan expression in distal regions compared with proximal regions persisted. The tensile and compressive forces experienced in the examined regions may be related to the regional differences found in gene expression. The lower mRNA expression of the genes examined in the OVH group confirms a potential effect of systemic estrogen on tendon.

S.P.51 A study of below knee serial casting for calf contracture in ambulant boys with Duchenne muscular dystrophy

Abstract The progressive muscle weakness that occurs in Duchenne muscular dystrophy (DMD) is known to be associated with secondary muscle tightness and contracture. The Achilles tendon (TA) and calf muscle complex (gastrocnemius and soleus) is typically one of the earliest and most severely affected muscle groups. It has been noticed clinically that there is a subset of boys who develop surprisingly early shortening in the presence of well-preserved lower limb muscle strength. A small prospective study has commenced to assess the effects of short term below knee serial casting on muscle length as well as strength, physical function and endurance. Tight inclusion criteria ensure that only boys with good anti-gravity muscle strength and range of motion at hip and knee are included. Outcome measures include goniometry, myometry, timed function tests, the North Star Ambulatory Assessment, Six Minute Walk Test, falls frequency and measurement of gait parameters using the GAITRite system. Early data will be presented.

Methodology for Use of a Neuroprosthetic to Reduce Plantar Pressure: Applications in Patients with Diabetic Foot Disease

Methodology for Use of a Neuroprosthetic to Reduce Plantar Pressure: Applications in Patients with Diabetic Foot Disease

A new surgical method to treat chronic ruptures and reruptures of the Achilles tendon

In patients with a chronic rupture or rerupture of the Achilles tendon, the recommended treatment is surgical. Various surgical techniques have been reported in the literature; however, the outcome is rarely evaluated with a sufficiently long follow-up, using appropriate end-points. The purpose of this study was to evaluate the subjective and objective outcome following a new surgical treatment for chronic rupture or rerupture of the Achilles tendon using augmentation with a free gastrocnemius aponeurosis flap. A total of 28 consecutive patients (22 male and 6 female) with a mean (SD) age of 46 (10.4) years were evaluated at a median (range) of 29 (12-117) months after surgery. The surgical technique involved making a single incision and then using a free gastrocnemius aponeurosis flap to cover the tendon gap after an end-to-end suture. The patients were evaluated using the Achilles tendon rupture score (ATRS) and a detailed questionnaire relating to symptoms, physical activity and satisfaction with treatment. The functional evaluation consisted of a validated test battery measuring different aspects of muscle/tendon function of the gastrocnemius/soleus and Achilles tendon complex. The median (range) ATRS was 83 (24-100). There were no reruptures. In terms of surgical complications, there was one deep infection, three wound closure complications and deep venous thrombosis in two patients. All but one patient returned to work within 6 months of surgery. Sixteen (57%) patients were satisfied with the treatment. There was a significant decrease in the level of physical activity after the injury compared with before the injury (p = 0.004). Of the 25 patients who participated in recreational sports prior to injury, 13 (52%) returned to the same activity level after treatment. In terms of jump performance, no significant differences were found between the healthy and injured sides. There was, however, a significant decrease in strength, in terms of both concentric and eccentric-concentric toe raises and the toe-raise test for endurance compared with the healthy side. The use of a free gastrocnemius aponeurosis flap to treat chronic ruptures and reruptures of the Achilles tendon rendered a good overall subjective and objective outcome in the majority of patients. The use of a single incision in combination with a free flap augmentation produced favourable results.

Evaluation of lower leg function in patients with Achilles tendinopathy

Achilles tendinopathy is considered to be one of the most common overuse injuries in elite and recreational athletes. However, the effect that the Achilles tendinopathy has on patients' physical performance is still unclear. The purpose of this study was to evaluate if Achilles tendinopathy caused functional deficits on the injured side compared with the non-injured side in patients. A test battery comprised of tests for different aspects of muscle-tendon function of the gastrocnemius, soleus and Achilles tendon complex was developed to evaluate lower leg function. The test battery's test-retest reliability and sensitivity (the percent probability that the tests would demonstrate abnormal lower limb symmetry index in patients) were also evaluated. The test battery consisted of three jump tests, a counter movements jump (CMJ), a drop counter movement jump (drop CMJ) and hopping, and two strength tests, concentric toe-raises, eccentric-concentric toe-raises and toe-raises for endurance. The reliability was evaluated through a test-retest design on 15 healthy subjects. The test battery's sensitivity and possible functional deficits in patients with Achilles tendinopathy were evaluated on 42 patients (19 women and 23 men). An excellent reliability was found between test days 1-2 and 2-3 for all tests (ICC = 0.76-0.94) except for concentric toe-raise, test 2-3, which had fair reliability (ICC = 0.73). The methodological error ranged from 8 to 17%. There were significant differences (P = 0.001-0.049) between the non-injured (or least symptomatic) side and injured (most symptomatic) side for hopping, drop CMJ, concentric and eccentric-concentric toe-raises, and significant differences (P = 0.000-0.012) in the level of pain during CMJ, hopping, and drop CMJ. The sensitivity of the test battery at a 90% capacity was 88. Achilles tendinopathy causes not only pain and symptoms in patients but also apparent impairments in various aspects of lower leg muscle-tendon function as measured with the test battery. This test battery is reliable and able to detect differences in lower leg function between the injured or "most symptomatic" and non-injured or "least symptomatic" side in patients with Achilles tendinopathy. The test battery has higher demand on patients' function compared with each individual test.

Mechanical loading regulates the expression of tenascin-C in the myotendinous junction and tendon but does not induce de novo synthesis in the skeletal muscle.

Tenascin-C is a hexabrachion-shaped matricellular protein with a very restricted expression in normal musculoskeletal tissues, but it is expressed abundantly during regenerative processes of these tissues and embryogenesis. To examine the importance of mechanical stress for the regulation of tenascin-C expression in the muscle-tendon unit, the effects of various states of mechanical loading (inactivity by cast-immobilization and three-varying intensities of subsequent re-activity by treadmill running) on the expression of tenascin-C were studied using immunohistochemistry and mRNA in situ hybridization at the different locations of the muscle-tendon unit of the rat gastrocnemius muscle, the Achilles tendon complex. This muscle-tendon unit was selected as the study site, because the contracting activity of the gastrocnemius-soleus muscle complex, and thus the mechanical loading-induced stimulation, is easy to block by cast immobilization. Tenascin-C was expressed abundantly in the normal myotendinous and myofascial junctions, as well as around the cells and the collagen fibers of the Achilles tendon. Tenascin-C expression was not found in the normal skeletal muscle, although it was found in blood vessels within the muscle tissue. Following the removal of the mechanical loading-induced stimulation on the muscle-tendon unit by cast immobilization for 3 weeks, the immonoreactivity of tenascin-C substantially decreased or was completely absent in the regions expressing tenascin-C normally. Restitution of the mechanical loading by removing the cast and allowing free cage activity for 8 weeks resulted in an increase in tenascin-C expression, but it could not restore the expression of tenascin-C to the normal level (in healthy contralateral leg). In response to the application of a more strenuous mechanical loading stimulus after the removal of the cast (after 8 weeks of low- and high-intensity treadmill running), the expression of tenascin-C was markedly increased and reached the level seen in the healthy contralateral limb. Tenascin-C was abundantly expressed in myotendinous and myofascial junctions and in the Achilles tendon, but even the most strenuous mechanical loading (high-intensity treadmill running) could not induce the expression of tenascin-C in the skeletal muscle. This was in spite of the marked immobilization-induced atrophy of the previously immobilized skeletal muscle, which had been subjected to intensive stress during remobilization. mRNA in situ hybridization analysis confirmed the immunohistochemical results for the expression of tenascin-C in the study groups. In summary, this study shows that mechanical loading regulates the expression of tenascin-C in an apparently dose-dependent fashion at sites of the muscle-tendon unit normally expressing tenascin-C but can not induce de novo synthesis of tenascin-C in the skeletal muscle without accompanying injury to the tissue. Our results suggest that tenascin-C provides elasticity in mesenchymal tissues subjected to heavy tensile loading.

Repair of neglected Achilles tendon ruptures: procedures and functional results.

Surgical repair of neglected Achilles tendon ruptures presents the challenge of restoring the function of the Achilles tendon complex while repairing the large defect that is created by the delay in appropriate treatment. We present our preferred technique for delayed repair and the results of six patients who were available for complete follow-up evaluation. The combined surgical technique includes: V-to-Y gastrocnemius recession or advancement, excision of the fibroadipose defect, end-to-end anastomosis, gastrocnemius aponeurotic flap to reinforce the anastomosis. Each of six patients were interviewed and examined clinically and by Cybex II isokinetic strength testing. All six patients have been able to return to their pre-injury activities. Cybex II isokinetic strength testing demonstrated peak torque deficiencies in plantar flexion ranging from 2.5%-22% as compared with the unaffected limb. The overall results of the technique described indicate that very satisfactory functioning of a neglected Achilles tendon rupture can be obtained.

The Effect of Indomethacin on Achilles Tendon Healing in Rabbits

In a randomized, blind study, percutaneous tenotomy was performed on the right Achilles tendon complex of 32 male, New Zealand rabbits. The rabbits were placed in long-leg casts to approximate the tendon. Sixteen rabbits received oral therapeutic doses (1.5 mg/kg/day) of indomethacin elixir; the remaining 16 rabbits received no medication and comprised the control group. At two and six weeks following tenotomy, eight rabbits in each group were sacrificed and the Achilles tendon complexes were resected. Each tendon was evaluated for tensile force-to-failure by uniaxial tensile loading using an Instron Materials Testing Machine at a velocity of 0.85 cm/second. Histologic evaluation assigned the specimens to categories of either "relatively mature" or "relatively immature," based on the degree of cellularity, neovascularity, and collagen orientation that had occurred in the healing process. The mean force-to-failure two weeks post-tenotomy for the experimental group was 75.7 +/- 42.3 Newtons (N), and 96.6 +/- 35.2 N for the control group; at six weeks post-tenotomy, the mean force-to-failure for the experimental group was 165.5 +/- 34.3 N and 160.2 +/- 31.6 N for the control group. Statistical analysis revealed no significant differences in tensile force-to-failure or histologic appearance between the experimental and control groups at either time interval. These results suggest that indomethacin, and potentially other nonsteroidal antiinflammatory drugs, may be used in conjunction with a tendon injury without significantly affecting the early healing process.