Objectives. The incidence of acute Achilles tendon rupture appears to be increasing. The aim of this study was to summarize various therapies for acute Achilles tendon rupture and discuss their relative merits. Methods. A PubMed search about the management of acute Achilles tendon rupture was performed. The search was open for original manuscripts and review papers limited to publication from January 2006 to July 2017. A total of 489 papers were identified initially and finally 323 articles were suitable for this review. Results. The treatments of acute Achilles tendon rupture include operative and nonoperative treatments. Operative treatments mainly consist of open repair, percutaneous repair, mini-open repair, and augmentative repair. Traditional open repair has lower re-rupture rates with higher risks of complications. Percutaneous repair and mini-open repair show similar re-rupture rates but lower overall complication rates when compared with open repair. Percutaneous repair requires vigilance against nerve damage. Functional rehabilitation combining protected weight-bearing and early controlled motion can effectively reduce re-rupture rates with satisfactory outcomes. Biological adjuncts help accelerating tendon healing by adhering rupture ends or releasing highly complex pools of signalling factors. Conclusion. The optimum treatment for complete rupture remains controversial. Both mini-open repair and functional protocols are attractive alternatives, while biotherapy is a potential future development. Cite this article: X. Yang, H. Meng, Q. Quan, J. Peng, S. Lu, A. Wang. Management of acute Achilles tendon ruptures: A review. Bone Joint Res 2018;7:561–569. DOI: 10.1302/2046-3758.710.BJR-2018-0004.R2

Aims. To determine whether platelet-rich plasma (PRP) injection improves outcomes two years after acute Achilles tendon rupture. Methods. A randomized multicentre two-arm parallel-group, participant- and assessor-blinded superiority trial was undertaken. Recruitment commenced on 28 July 2015 and two-year follow-up was completed in 21 October 2019. Participants were 230 adults aged 18 years and over, with acute Achilles tendon rupture managed with non-surgical treatment from 19 UK hospitals. Exclusions were insertion or musculotendinous junction injuries, major leg injury or deformity, diabetes, platelet or haematological disorder, medication with systemic corticosteroids, anticoagulation therapy treatment, and other contraindicating conditions. Participants were randomized via a central online system 1:1 to PRP or placebo injection. The main outcome measure was Achilles Tendon Rupture Score (ATRS) at two years via postal questionnaire. Other outcomes were pain, recovery goal attainment, and quality of life. Analysis was by intention-to-treat. Results. A total of 230 participants were randomized, 114 to PRP and 116 to placebo. Two-year questionnaires were sent to 216 participants who completed a six-month questionnaire. Overall, 182/216 participants (84%) completed the two-year questionnaire. Participants were aged a mean of 46 years (SD 13.0) and 25% were female (57/230). The majority of participants received the allocated intervention (219/229, 96%). Mean ATRS scores at two years were 82.2 (SD 18.3) in the PRP group (n = 85) and 83.8 (SD 16.0) in the placebo group (n = 92). There was no evidence of a difference in the ATRS at two years (adjusted mean difference -0.752, 95% confidence interval -5.523 to 4.020; p = 0.757) or in other secondary outcomes, and there were no re-ruptures between 24 weeks and two years. Conclusion. PRP injection did not improve patient-reported function or quality of life two years after acute Achilles tendon rupture compared with placebo. The evidence from this study indicates that PRP offers no patient benefit in the longer term for patients with acute Achilles tendon rupture. Cite this article: Bone Joint J 2022;104-B(11):1256–1265

Background. Disability and slow return to sport and work after tendon rupture are major challenges. Platelet Rich Plasma (PRP) is an autologous supraphysiological concentration of platelets from whole blood that has demonstrated positive cellular and physiological effects on healing in laboratory conditions but evidence from adequately powered robust clinical trials is lacking. We aimed to determine the clinical efficacy of PRP for treatment of acute Achilles tendon rupture. Methods. In a placebo-controlled, participant- and assessor-blinded, trial at 19 NHS hospitals we randomly assigned 230 adults starting acute Achilles rupture non-surgical management to PRP injection or dry-needle insertion (placebo) to the rupture gap under local anaesthetic. Patients with confounding or contraindicated concurrent medical conditions were excluded. The primary outcome was muscle-tendon function, assessed by the limb symmetry index (LSI, uninjured limb/injured limb × 100, higher scores better) of the work (Joules) performed during the heel-rise endurance test at 24 weeks. Secondary outcomes were: Achilles Tendon Rupture Score (ATRS, 0–100, higher scores better), quality of life (SF-12), pain, and goal attainment. Trial registration: ISRCTN54992179. Results. Participants were aged mean 46 years and 57 (25%) were female. 103/114 (90%) of the PRP group and all (n=116) in the placebo group received allocated treatment. At 24 weeks, mean LSI was 34.4 for the PRP group and 38.8 for placebo (adjusted mean difference −4.4 95% CI −11.2 to 2.5, n=201) and ATRS was mean 65.2 PRP vs 65.8 (adjusted mean difference −0.6, 95% CI −4.9 to 3.7, n=224). There were no differences between groups in the other secondary outcomes. Conclusion. We found no evidence of PRP efficacy for improving muscle-tendon function or patient-reported recovery after acute Achilles tendon rupture. Our findings challenge the increasing global use of PRP for acute tendon injury and indicate that robust evaluations are required in other applications

The aim of this study was to identify factors independently associated with symptomatic venous thromboembolism (VTE) following acute Achilles tendon rupture (ATR), and to suggest a clinical VTE risk assessment tool for patients with ATR. From 2010–2018, 984 consecutive adults (median age 47yrs, 73% male) sustaining an ATR were retrospectively identified. There were 95% managed non-operatively (below-knee cast 52%, n=507/984; walking boot 44%, n=432/984), with 5% (n=45/984) undergoing primary operative repair (<6wks). VTE was diagnosed using medical records and national imaging archives, reviewed at a mean of 5yrs (1–10) post-injury. Regression was performed to identify factors independently associated with VTE. Incidence of VTE within 90 days of ATR was 3.6% (n=35/984; deep vein thrombosis 2.1% [n=21/984], pulmonary embolism 1.9% [n=19/984]). Age ≥50yrs (adjusted OR [aOR] 2.3, p=0.027), personal history of VTE/thrombophilia (aOR 6.1, p=0.009) and family history of VTE (aOR 20.9, p<0.001) were independently associated with VTE. These non-modifiable risk factors were incorporated into a VTE risk assessment tool. 23% of patients developing VTE (n=8/35) had a relevant personal or family history, but incorporating age into the tool identified 69% of patients with VTE (n=24/35). Non weight-bearing ≥2wks after ATR was also independently associated with VTE (aOR 3.2, p=0.026). Age ≥50 years, personal history of VTE/thrombophilia and a positive family history were independently associated with VTE following ATR. Incorporating age into our suggested VTE risk assessment tool enhanced sensitivity in identifying at-risk patients. Early weight-bearing in an appropriate orthosis may be beneficial in VTE risk reduction

Background. The PATH-2 trial found no evidence of a benefit of Platelet Rich Plasma (PRP) injection versus a placebo after Achilles tendon rupture (ATR) at six-months. ATR often leave longer-term functional deficiencies beyond six-months. This study aim is to determine if PRP affect tendon functional outcomes at two-years after rupture. Study design. Randomised multi-centre two-arm parallel-group, participant- and assessor-blinded, superiority trial. Methods. Adults with acute ATR managed non-surgically were recruited in 19 UK hospitals from 2015 to 2019. Exclusions were insertion or musculotendinous injuries, leg injury or deformity, diabetes, haematological disorder, corticosteroids and anticoagulation therapy. Participants were randomised via an online system 1:1 to PRP or placebo. Primary outcome was Achilles Tendon Rupture Score (ATRS) at two-years. Secondary outcomes were pain, Patient-Specific Functional Scale (PSFS), SF-12 and re-rupture. Assessors were blinded. Intention-to-treat and Compliance Average Causal effects (CACE) analyses were carried out. Consistency of effects across subgroups age, BMI, smoking and gender were assessed using Forest plots. Pearson's correlation was used to explore ATRS correlation with blood and growth factors. Results. 216/230 (94%) participants completed the 6-months follow-up were contacted. 182/216 (84%) completed the two-year follow-up. Participants were aged mean 46 (SD 13.0), 57 female/159 male. 96% received the allocated intervention. Two-years ATRS scores were 82.2 (SD 18.3) in the PRP group (n=85) and 83.8 (SD 16.0) in the placebo group (n=92). There was no evidence of a difference in the two-years ATRS (adjusted-mean difference −0.752 95%CI −5.523 to 4.020, p=0.757), or in any secondary outcome, and no re-rupture between at two-years. Neither PRP cellular or growth factors correlated with the two-year ATRS. Conclusion. PRP did not improve patient-reported function or quality of life two-years after acute Achilles tendon rupture, compared with placebo, indicating that PRP offers no patient benefit in the longer term

Background: 75% of Achilles tendon ruptures are related to physical activities. The best method of treatment for acute Achilles tendon rupture is still debated. Treatment options can be classified as Nonoperative based on cast immobilization, open surgery, and percutaneous surgery based on passing sutures through several stab incisions. Common complications include re-ruptures, infection, wound problems and sural nerve injury. Recent reports of percutaneous surgery show good functional outcome, low incidence of re-ruptures, fewer wound healing problems and prompt recovery. Objective: Assessment of percutaneous operative treatment outcome. Methods: 73 patients treated for acute Achilles tendon rupture with percutaneous surgery in the past eight years are followed. Evaluations were preformed at an average of 34.6 months postoperatively (range, 17 to 54 months). Outcome was evaluated by analyzing Epidemiologic, subjective and objective parameters. Results: The patients demonstrated good functional outcome, with none – to mild limitations in recreational activities. Ankle range of motion was not statistically different between both ankles. Evaluation of strength and power with the Cybex II dynamometer revealed a difference at 240 deg/sec for plantar flexion power between the injured and healthy leg, but no difference at 30 and 90 deg/sec, or in dorsiflexion power and strength. Complication rate was low: sural nerve injury (1 patient), superficial wound infection (2 patients), suture granuloma (4 patients) and re-rupture (1 patient). Conclusions: In our series, percutaneous operative treatment was found to be simple, fast and can be done under local anesthesia. Our low complication rate and excellent functional results make this treatment an appealing alternative to either conservative or open surgical suture

Background. This retrospective analysis was prompted by the authors' observation of the relatively high incidence of venous thromboembolism (VTE) in the surgical repair of acute Achilles tendon ruptures. Method. 88 patients were treated surgically for an acute Achilles tendon rupture. No prophylactic anticoagulation was given to any patients. The incidence of VTE was then reviewed retrospectively. Results. Five patients developed symptomatic deep vein thrombosis (5.7%) and one a near-fatal pulmonary embolus (1.1%). There were no major bleeding or cardiovascular adverse events. One patient developed a thrombus of the the lesser saphenous vein (1.1%) and there was one superficial sepsis (1.1%). A temporary peroneal nerve palsy occurred in one patient (1.1%). There were two re-ruptures (2.3%). Conclusion. There is no doubt that thromboprophylaxis must be given to the high risk patient and is also recommended for major orthopaedic surgery. Limited data is available for the use of thromboprophylaxis in foot and ankle surgery. In light of the unacceptably high incidence of venous thromboembolism in this study, the authors suggest that routine venous thromboembolism prophylaxis should be considered for these patients. MULTIPLE DISCLOSURES

Introduction. Venous thromboembolism (VTE) is a significant cause of patient morbidity and mortality, the risk of which increases in orthopaedic patients with lower limb immobilisation. This incidence should in theory reduce if the patients are ambulatory early in the treatment phase. The aim of this study was, therefore, to identify a difference in the incidence of symptomatic VTE by treating acute Achilles tendon rupture patients with conventional non-weight bearing plaster versus functional weight bearing mobilisation. Methodology. The notes of 91 consecutive patients with acute Achilles tendon rupture were retrospectively reviewed and prospectively followed. The patients' demographics, treatment modality (non-weight bearing plaster versus weight bearing boot), and the type of plaster immobilisation was compared to assess whether they affect the incidence of clinical VTE. The predisposing risk factors were also analysed between the treatment groups. Out of 91 patients, 50 patients with acute Achilles tendon rupture were treated conservatively in a conventional non-weight bearing immobilisation cast. From these 50 patients, 3 then underwent surgery and were therefore excluded from the results. On the other hand, 41 patients were treated with functional weight bearing mobilisation (Vacupad). Patients who did have a symptomatic thromboembolic event also had an ultrasound scan to confirm a deep vein thrombosis of the lower limb or a CT-scan to confirm pulmonary embolism. Results. Out of the 47 patients who were treated conservatively in a non-weight bearing plaster cast, 9 patients had a thromboembolic event (19.1%). On the other hand, out of the 41 patients who were treated with functional weight bearing mobilisation, only 2 patients had a symptomatic thromboembolic event (4.2%). This was statistically significant (p=0.012). This shows that patients who are treated in a non-weight bearing plaster have about five times increased risk of developing a sypmptomatic VTE compared to those treated by functional weight bearing mobilisation. There was however no difference in the predisposing factors in patients who developed VTE compared to those who did not. Conclusion. The incidence of symptomatic VTE after acute Achilles tendon rupture is high and under-recognised. Asymptomatic VTE after this injury is probably even higher. There is a significant decrease in the clinical incidence of thromboembolic events in patients treated conservatively with early mobilisation in the functional weight bearing boot compared to those treated in a non-weight bearing cast. There is a need for further research to define the possible benefit of thromboprophylaxis in patients treated by non-weight bearing plasters

Treatment of acute Achilles tendon rupture is based on obtaining and maintaining apposition of the ruptured tendon ends. Surgical treatment utilises direct suture repair to produce this objective, while conservative or non-surgical management achieves the same effect of closing the tendon gap by immobilisation of the ankle joint in a plantar flexed position within a plaster cast or POP. There is still variability in the conservative treatment practices and protocols of acute Achilles tendon ruptures. The purpose of this study is to examine the current practice trends in the treatment of Achilles tendon ruptures amongst orthopaedic surgeons in the UK. A postal questionnaire was sent to 221 orthopaedic consultants in 25 NHS hospitals in the Greater London area in June 2010. Type and duration of immobilisation were considered along with the specifics of the regime used. Ninety questionnaires were returned giving a 41% response rate. Conservative treatment methods were used by 72% of respondents. A below knee plaster was the top choice of immobilisation (83%) within this group. The mean period of immobilisation was 9.2 weeks (Range 4-36). Weight bearing was allowed at a mean of 5.3 weeks (range 0-12). The specific regime used by consultants was quite heterogeneous across the group, however the most used immobilisation regimen was a below knee plaster in equinus with 3 weekly serial plaster changes to a neutral position, for a total of nine weeks. A heel raise after plaster removal was favoured by 73% of respondents used for a mean period of 6.4 weeks (Range 2-36). In response to ultrasound use as a diagnostic tool, 42.4% of respondents would never use it, 7.6% would use it routinely, while 50% would use it only according to the clinical situation. Comparison of foot and ankle specialists with non-specialists did not reveal a significant difference in practice in duration of immobilisation or time to bearing weight. Conservative management remains a widely practice option in the treatment of Achilles tendon ruptures. Although there are available a number of modern walking aids, the concept of functional brace immobilisation is not as widely used as below knee plaster cast immobilisation, which remains a popular choice amongst orthopaedic surgeons today. There is still no consensus on the ideal immobilisation regimen although a below knee plaster in equinus with serial changes for a total of nine weeks is the most frequently used choice. Further randomised controlled trials are required to establish the optimal treatment strategy for conservative management of Achilles tendon rupture

Introduction/Aim. Thromboembolism is a significant cause of patient morbidity and mortality, the risk of which increases in orthopaedic patients with lower limb immobilisation. It was therefore, our aim to identify a difference in symptomatic thromboembolism by treating acute Achilles tendon rupture patients with conventional non- weight bearing plaster versus functional weight bearing mobilisation. Methodology. The notes of 91 consecutive patients with acute Achilles tendon rupture were reviewed. The patients' demographics, treatment modality (non- weight bearing plaster versus weight bearing boot), and predisposing risk factors were analysed. From the 91 patients, 50 patients with acute Achilles tendon rupture were treated conservatively in a non- weight bearing immobilisation cast. From these 50 patients, 3 then underwent surgery and were therefore excluded from the results. 41 patients were treated with functional weight bearing mobilisation. Patients who did have a symptomatic thromboembolic event had an ultrasound scan to confirm a deep vein thrombosis of the lower limb, or a CT-scan to confirm pulmonary embolism. Results. Out of the 47 patients who were treated conservatively in a non-weight bearing plaster cast, 9 patients (19.1 %) had a thromboembolic event. Out of the 41 patients who were treated with functional weight bearing mobilisation, 2 patients (4.8%) had a thromboembolic event. Thus, patients who were treated in a non-weight bearing plaster had a significantly higher risk of developing thromboembolism (p value of <0.05) and an increased risk ratio of 24% compared to those who were treated with functional weight bearing mobilisation. Conclusion. There is a significant decrease in the clinical incidence of thromboembolic events in patients treated conservatively with early mobilisation in the functional weight bearing boot compared to those treated in a non- weight bearing cast

Background. Operative fixation of acute tendo-achilles ruptures remains controversial. Standard surgical exposure is associated with and increased risk of wound breakdown and infections. The mini-open technique was developed to minimise these risks and provide anatomical reduction/apposition of the tendon rupture. Methods. We present a retrospective case series of 27 patients who were treated operatively for acute Achilles tendon rupture in the hands of 1 surgeon, between 4–6 years post operatively, using Achillon instrumentation. Post operatively they were treated with an air cast boot and 3 wedges, bringing the foot into neutral by 6 weeks followed by a rehabilitation programme. The patients were contacted via telephone and consent was obtained. The complications, Leppilahti score and ATRS score were then calculated. Results. 2 patients underwent a further operation (one for a retained suture and another for a re-rupture in an uncompliant patient), in total there were 2 re-ruptures (another patient sustained a partial rupture which was treated conservatively). There were no patients who sustained a wound problem or infection (other than the patient already mentioned). There were 3 patients who complained of ongoing altered sensation in the sural nerve distribution, and 4 who had paraesthesia post operativeley that completely resolved within 3 months. There were no DVT/PE reported and the average Leppilahti score was 85.7/100 (excellent outcome) and ATRS 93.3/100 (excellent outcome). Conclusion. This study shows that the mini-open technique can be used successfully to treat acute tendo-Achilles ruptures with excellent long term outcome

Introduction/Aim. Thromboembolism is a significant cause of patient morbidity and mortality, the risk of which increases in orthopaedic patients with lower limb immobilisation. It was therefore, our aim to identify a difference in symptomatic thromboembolism by treating acute Achilles tendon rupture patients with conventional non-weight bearing plaster versus functional weight bearing mobilisation. Methodology. The notes of 91 consecutive patients with acute Achilles tendon rupture were reviewed. The patients demographics, treatment modality (non-weight bearing plaster versus weight bearing boot), and predisposing risk factors were analysed. From the 91 patients, 50 patients with acute Achilles tendon rupture were treated conservatively in a non-weight bearing immobilisation cast. From these 50 patients, 3 then underwent surgery and were therefore excluded from the results. 41 patients were treated with functional weight bearing mobilisation. Patients who did have a symptomatic thromboembolic event had an ultrasound scan to confirm a deep vein thrombosis of the lower limb, or a CT-scan to confirm pulmonary embolism. Results. Out of the 47 patients who were treated conservatively in a non-weight bearing plaster cast, 9 patients (19.1 %) had a thromboembolic event. Out of the 41 patients who were treated with functional weight bearing mobilisation, 2 patients (4.8%) had a thromboembolic event. Thus, patients who were treated in a non-weight bearing plaster had a significantly higher risk of developing thromboembolism (p value of <0.05) and an increased risk ratio of 24% compared to those who were treated with functional weight bearing mobilisation. Conclusion. There is a significant decrease in the clinical incidence of thromboembolic events in patients treated conservatively with early mobilisation in the functional weight bearing boot compared to those treated in a non-weight bearing cast

Aim: To study the results of a percutaneous suture technique for the management of acute ruptures of the Achilles’ tendon. Method: Ten patients with acute Achilles’ tendon rupture were entered into the study. We utilised a percutaneous surgical technique and functional post-operative regime described in the current literature. Results: All were recreational sports people with an average age of 42.9 years. At an average follow-up of six months there were no re-ruptures, no wound complications, no sural nerve injuries, and no episodes of deep vein thrombosis. No patient had any discomfort during normal walking. In comparison to the uninjured side, there was still a mild reduction in calf circumference but minimal deficits in endurance, strength or range of motion. Conclusions: The technique was easily performed and overall the treatment appeared to have very high patient acceptance and low morbidity. The well described benefits of early mobilisation were evident

Introduction

Achilles tendon rupture (ATR) account for 10.7% of all tendon and ligament injuries and causes lasting muscular deficits and have a profound impact on patients’ quality of life^1,2. The incidence, characteristics and management of ATR in the United Kingdom is poorly understood.

We examined 52 patients with acute Achilles tendon rupture (ATR), 43 men and 9 women, with a median age of 43 (28–68) years after percutaneous Achilles tendon repair with early functional therapy. 11 patients were treated in a cast (C) and 41 had a specially designed shoed (S). The mean follow-up was 56 (36–95) months. Patients suffering from health problems, which could affect their gait and balance (e.g. OA, spinal stenosis,…), as well as patients suffering from complications postoperatively, were excluded from the study. The mean Hannover Achilles Tendon Score was 81 (50 – 95) points (C = 81, S = 81). Their calf muscle function studied three to eight years after treatment were found to have a significantly impaired dynamic muscle function of the calf muscles when tested in a specially constructed heel-raise test device. The Wilcoxon matched-pairs signed-ranks test showed a two-tailed P value of < 0,0001. The average calf size was 38 (31–46,5) cm on the uninjured side and 36 (32–44,5) cm on the injured side. Only two patients had an equal calf size. Comparing the uninjured and injured side the two-tailed P value was found to be extremely significant < 0,0001. The correlation between the maximum force and functional heel raise testing to the calf size on the injured side was weak with a Spearman correlation coefficient (r) = 0,33–38. There was no difference found between the patients treated in a cast and the patients treated in a shoe with percutaneous Achilles tendon repair and early functional therapy. The principle finding in the present study was that the impact of an ATR is of great importance for the functional outcome than the treatment that is given. The difference in flexion strength and endurance between the injured and the uninjured side remained even after a 56 months follow-up. Therefore, calf size and functional muscle testing is a good tool to test functional outcome after Achilles tendon rupture. However, there was only a weak correlation between the size of atrophy and the amount of force reduction

Introduction

Conservative treatment of Achilles tendon ruptures may lead to re-rupture. Open surgical repair entails a risk of skin necrosis or infection. Several percutaneous techniques have been used, like Tenolig® or Achillon®, but these techniques are costly and may be marred by wound healing problems. Ma and Griffith described a technique for percutaneous repair witch left the suture and the knot under the skin, thus reducing the risk for infection.

Aim

To determine the influence of tendo achilles (TA) rupture gap distance and location on clinical outcome managed with accelerated functional rehabilitation.

Achilles tendon rupture may lead to significant functional deficits, which mechanisms are poorly understood. The primary aim was to investigate if the Achilles tendon (AT) was longer, muscles weaker or gait changed on the injured leg 4–5 years after the injury. Secondary aim was to compare functional outcomes with patient reported Achilles Tendon Total Rupture Score (ATRS).

We invited all participants from an RCT of conservatively treated AT Rupture (ATR) with or without early weight-bearing (early-WB, non-WB), and 12 moths of follow up. Of the original 56, 37 patients participated, 19 from early-WB (1 re-rupture (RR)), and 18 from non-WB (2 RR). Time from injury to follow up was 4,5 years (4,1 to 5,1). AT length was measured using ultrasound with a validated protocol (Barfod K.W. et al.). Heel raise work was measured on a 10 degree inclining platform. The exercise lasted until the patient could not maintain frequency or height of lift. Number and height of lift was measured using reflective markers in a Vicon system, and total work calculated. Foot pressure mapping (FPM) was measured barefoot, using an EMED platform (novel, Germany). Statistics: T-test for limb to limb comparisons and linear regression for ATRS correlations was applied.

Including RR in the sample did not impact the results. We found no differences in any of the variables between the early-WB and non-WB groups. Compared to the uninjured limb, the Achilles tendon was an average of 1,8 (1,2–2,3) cm longer on the injured limb, which produced 40% less work. A smaller calf circumference (p < 0.001), larger dorsiflextion (p = 0.001), and Achilles tendon resting angle (p < 0.001) was found for the injured limb. Difference in mean medial forefoot peak pressure was approaching significance (healthy 484 (SD 165) KPa, injured: 439 (SD 160), p = 0.08). Similarly the difference in pressure / time integral of the medial forefoot was approaching significance (Healthy: 129 (SD 35)KPa, injured: 115 (SD 44)KPa, p = 0.08). Duration of contact time of the heel was extended and heel lift off was delayed in the injured limb (p = 0.02 for both). ATRS could not be linked to Achilles tendon length or total work using linear regression.

Conservatively treated Achilles tendon ruptures were approximately 1,8 cm longer. The limb was persistently weaker. A subtle change in heel contact duration and time of heel rise could be detected on the injured limb. ATRS does not appear to correlate directly with AT length or loss of total work.

Aim: Experimentally forming a frayed Achilles tendon rupture model in rabbit and repairing the ruptured site with different methods; after the tendon healing, with the help of biomechanical and histopathological analyses, to find out which repair method is the most ideal.

Material and Method: This study was carried out using 34 mature, female New Zealand type of rabbits with weights ranging 2200 to 2900 grams (2429,4 on average). The animals were divided into two groups named P and V, each with 17 rabbits. In each group, Achilles tendon on the right side was employed for the experiment (Pd and Vd) and the other side as a control (Pk and Vk). In the experiment groups, a frayed Achilles tendon rupture was performed. The control groups, however, received no procedures. After the primary repair, the Achilles tendons in the group Pd were augmented with the plantaris tendon. The Achilles tendons in the group Vd were primarily repaired after releasing gastrocnemius aponeurosis using “inverted-V” incision. In both groups, an above-knee cast was applied on the surgically procedured sides. After six weeks of observation, the repaired sites on tendons in the animals alive were analyzed biomechanically and histopathologically. 12 and 3 animals from each group were used respectively for the biomechanical and the histopathological analyses.

Results: The elongation at tendon to rupture was 3,02±0,47 mm for Pd and 2,86±0,35 mm for Vd. The difference between two groups, however, was not statistically significant (p> 0,05). The maximum load at rupture for Pd was 105,88±38,14 N, and it was 71,95±17,44 N for Vd, thus the difference was statistically significant (p< 0,05). The energy needed to initiate a damage to the tendon was 0,1979±0,0902 J for Pd, and 0,1309±0,0368 J for Vd, the difference was also statistically significant (p< 0,05). The elongation, maximum load and energy values were lower in Pd group than in Pk, and in Vd group than in Vk, and the differences between each groups were statistically significant (p< 0,05). In histopathological sense, the tendon healing process in group Pd was faster than in group Vd.

Conclusion: Although the repairs made with the augmentation of plantaris tendon yielded better results; the tendon, no matter which method is used, could not has its former strength. Results are bound to be better with stronger repair, and if the repair as much as supported by adjacent tendinous structures.

Key Words: Achilles tendon, rupture, primary repair, m. plantaris, rabbit

Tendon healing is a complex process that often results in compromised healing of the tendon tissue. It has recently been shown that temporal changes in the expression profile and the histological tissue quality of the tendons occur during the early healing process after acute Achilles tendon rupture. Whether these changes are accompanied by an altered healing process, is not yet known and was the aim of the present study. Tendon biopsies were obtained from 24 patients with acute Achilles tendon rupture at the time of surgery (2–9 days after rupture) and examined histologically as well as on RNA level. Histologically, the tendon architecture, the amount of aligned collagen, glycosaminoglycan and fat as well as the cellularity, vascularity and immune cell infiltration were determined. On RNA level the expression of markers for the modeling/remodeling (MMPs and TIMPs), collagens (1, 3, 5), tendon markers (scleraxis, tenomodulin), pro- and anti-inflammatory markers (IL-1beta, IL6, IL10, IL33, TNFa, TGF-beta1, COX2) and immune cell markers (CD3, CD68, CD80, CD206) were analyzed by Real-Time PCR. To determine the clinical outcome, the patients were followed up 12 months after the operation and the following scores were recorded: Subjective score, Tegner score, Visual Analog Scale (VAS) pain, VAS function, Matles Test, Achilles tendon total rupture score (ATRS), Therman 100-points score, Heel rise test. Statistics: Spearman correlation analysis. Correlation analysis shows that early post-rupture surgery is associated with better clinical outcome (ATRS Score: p=0.022). Histologically, a good functional healing outcome shows a positive correlation to the amount of aligned collagen (Heel Rise Test: p = 0.009) and glycosaminoglycans in the tendon (Heel Rise Test: p = 0.026, Matles difference: p = 0.029), as well as a negative correlation to the fat content (Thermann score: p = 0.018, subjective score: p = 0.027, VAS function: p = 0.031). On RNA level, a good healing outcome correlates with increased expression of MMP13, collagen 1, 3, 5 (Heel Rise Test: p = 0.019, p = 0.048, p = 0.030), and TIMP2 (Tegner Score: p = 0.040), TGF-beta1 (Thermann Score: p = 0.032) and CD80 (ATRS: p = 0.025, Thermann score:, p = 0.032). Whereas a limited healing outcome is associated with an increased expression of MMP2 (Heel Rise Test: p = 0.033), MMP3 (Matles Test: p=0.001, Heal Rise test p = 0.017), and IL33 (Tegner Score: p = 0.047). The results of the study show a clear relationship between the tendon biology at the time of the surgery and the clinical and functional healing outcome 12 months after the operation. Especially matrix formation and remodeling play a crucial role, while the examined immunological factors seem to influence the tendon healing to a lesser extent. The modulation of matrix formation could potentially lead to improved treatment options in the future