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Achilles tendon rupture

107 citationsUpdated Sep 2026

Overview

Achilles tendon rupture incidence has increased, yet the use of operative treatment has decreased [37]. Despite a large body of evidence, controversy remains regarding the management of both acute and chronic ruptures [2]. The American Academy of Orthopaedic Surgeons (AAOS) recommendations range from Inconclusive to Moderate, indicating that further studies are needed for stronger guidance [9]. A 2024 guideline serves as a valuable resource for physicians making decisions regarding the surgical treatment of patients with chronic Achilles tendon rupture [12].

Operative treatment decreases rerupture rates but increases the risk for minor complications compared to non-operative management [35, 36]. Conversely, results indicate no differences in reoperation rates between operative and nonoperative management [49]. For acute ruptures, studies suggest equivalent functional outcomes with or without surgical treatment provided a functional rehabilitation program is followed [132]. While operative treatment is preferable, nonoperative treatment remains an acceptable alternative [60]. In chronic ruptures, surgical intervention yields superior patient-reported outcomes compared with non-surgical treatment [1]. Both nonoperative and operative management of myotendinous Achilles tendon ruptures demonstrate good outcomes, although literature on this specific topic is limited [27].

Surgical techniques, including open end-to-end repair and minimally invasive approaches, provide consistent good to excellent long-term functional outcomes [3, 8]. Percutaneous and minimally invasive techniques yield essentially identical clinical and functional outcomes with no reruptures or major complications observed at a minimum follow-up of 24 months [23]. Overall, surgical treatment achieves excellent or good outcomes in 91% of patients [28]. Intraoperative ultrasonography assistance for minimally invasive repair is an efficient, reliable, and safe method [50]. Timing influences outcomes; patients operated on within 48 hours after injury have better outcomes and fewer adverse events than those operated on after 72 hours [18]. However, percutaneous repair 14 to 30 days after injury achieves similar results at 1 year as treatment within 14 days [21], and patients presenting more than 2 weeks post-rupture may be successfully treated with minimally invasive repair [5]. Long-term recovery is protracted, with the majority of patients not fully recovered 2 years after injury regardless of treatment modality, showing only minor improvements between 1- and 2-year evaluations [4]. A clinically important difference in complication risk exists between minimally invasive surgical treatment and nonoperative treatment for acute ruptures, though this was not statistically significant [128].

Anatomy & Pathophysiology

Anatomy

The Achilles tendon is the thickest, strongest, and largest tendon in the human body, measuring approximately 12–15 cm in length [52]. It is formed by the confluence of the gastrocnemius and soleus tendons in the distal calf, inserting at the calcaneal tuberosity [152]. The gastrocnemius muscle attaches above the knee to the posterior aspect of the medial and lateral femoral condyles, while the soleus originates from the upper part of the posterior tibia, fibula, and interosseous membrane [54]. Functionally, the gastrocnemius is most effective in plantarflexion with the knee extended, whereas the soleus is most effective with the knee flexed [54]. The Achilles tendon is the only musculotendinous unit that crosses two major joints (knee and ankle, as well as subtalar) in the body [72]. It acts as the major plantar flexor of the ankle joint and serves as a weak knee flexor due to the gastrocnemius insertion on the posterior femoral condyles [72]. Additionally, it acts as an inverter of the heel because it runs just medial to the hindfoot axis of rotation [72].

At the insertion point, the fibers of the Achilles tendon rotate 90 degrees toward the calcaneal tuberosity [54]. This 90° internal rotation results in the medial gastrocnemius fibers lying posteriorly and the soleus fibers lying medially at the insertion [72, 54]. The tendon is innervated by the tibial nerve [72]. Unlike other tendons, the Achilles is surrounded by a paratenon consisting of loose areolar tissue rather than a true synovial sheath [72, 152]. This paratenon covers the tendon medially, posteriorly, and laterally [152]. Anteriorly, the tendon is marginated by Kager fat pad [152]. Lubrication is aided by two bursae: the retrocalcaneal bursa anterior to the tendon, which separates it from the underlying bone, and a superficial bursa posterior to the tendon [72, 152]. The plantaris tendon courses from superolateral to inferomedial along the ventral surface of the Achilles tendon, inserting onto either the distal Achilles tendon or the calcaneal tuberosity [152]. The sural nerve runs in the midline of the gastrocnemius-soleus muscle to the musculotendinous junction, where it crosses over to the lateral side of the tendon [72].

The major blood supply to the Achilles tendon is through its mesotendon, with the richest supply via the anterior mesentery [133]. Vascularity is also supplied through the paratenon on the deep surface, muscular arterial branches within the gastrosoleus complex proximally, and small interosseous vessels at the calcaneal insertion distally [54]. The lack of a true synovial sheath and local anatomy create a vascular watershed region in the tendon 2 to 6 cm above the insertion on the calcaneus [72].

Pathophysiology

A zone of relative avascularity exists 2 to 6 cm proximal to the insertion of the Achilles tendon into the calcaneus [54, 133]. Seventy-five percent of Achilles tendon ruptures occur between 5 and 6 cm proximal to the insertion on the calcaneal tuberosity, correlating with this zone of relative hypovascularity [39]. Tears of the Achilles tendon tend to occur in this critical zone [152]. Tears of the myotendinous junction proximally may occur in athletes, while insertional tears at the calcaneal tuberosity are associated with Haglund deformity [152].

The cause of Achilles tendon rupture is likely a combination of a relatively hypovascular area and repetitive microtrauma that causes an inflammatory reparative process unable to keep up with stresses due to decreased vascularity, completed by mechanical overload [133]. Repetitive microtrauma to the hypovascular area may make it impossible for the reparative process to keep pace, leading to degenerative attrition responsible for many ruptures [133]. With increasing age, the anterior mesenteric blood supply becomes reduced, and age-dependent changes in collagen crosslinking result in increased stiffness and loss of viscoelasticity, predisposing to injury [133]. A theory concerning the cause of rupture is the failure of inhibiting mechanisms at the musculotendinous unit as a result of fatigue, with resultant eccentric overload [133]. Most Achilles tendon ruptures occur as an indirect loading mechanism during eccentric muscle contracture [39]. These injuries share characteristic features including Achilles tendon elongation, closed-chain movements, and sudden loading [19]. Three-dimensional reconstruction reveals a multiplanar injury mechanism preceding the rupture [137].

In professional basketball, the most common mechanism of injury is taking off from a stopped position just before toe-off in a dorsiflexed foot [123]. Basketball-specific movement patterns include forefoot loading and rapid ankle dorsiflexion, along with proximal lower limb extension and musculotendinous complex elongation [169].

Achilles tendinopathy is diagnosed in 55% to 65% of Achilles tendon–related disorders [67]. The exact aetiology and pathophysiology of non-insertional Achilles tendinopathy are not fully known [175]. Tendon injury is thought to be caused by a failed healing process resulting in altered tendon structure, neovascularization, and nerve ingrowth [67]. The risk for developing Achilles tendinopathy is likely multifactorial and related to an interaction of intrinsic and extrinsic factors that lead to tendon overloading [67]. Lower extremity impairments that lead to abnormal kinetics and/or kinematics that specifically produce an eccentric overload can result in Achilles tendon injury [67]. Genes associated with the collagen-production pathway may functionally affect tendon strength and stiffness, leading to an abnormal tendon response during loading [67]. Individuals with a family history of tendinopathy have five times the risk of developing Achilles tendinopathy [67].

Achilles tendinosis does not always precede Achilles tendon rupture [55]. A subgroup of patients with an acute rupture have antecedent pain at the Achilles, and these tendons frequently show degenerative changes on histopathologic evaluation [39]. Pathological features are significantly more pronounced in samples taken from the site of rupture than in samples taken proximally and distal to it [7]. There are no significant differences in the mean pathologic sum-scores in samples taken proximally and distal to the site of rupture [7]. Unruptured Achilles tendons and ruptured Achilles tendons are distinct populations, with the latter demonstrating histopathological evidence of failed healing response even in areas macroscopically intact [7]. Chronic inflammation is a feature of both mid-portion Achilles tendinopathy and rupture [43]. Pro-inflammatory profiles differ slightly in ruptured tendons, likely due to acute inflammation and increased vascularisation resulting from recent trauma [43]. Achilles and rotator cuff tendons share common cellular and molecular inflammatory disease mechanisms [43].

Tendinosis of the Achilles tendon is most commonly due to hypoxia, which has a predisposition for the critical zone because of its relative hypovascularity [152]. Myxoid degeneration is the second most frequent etiology of Achilles tendinosis, referring to the accumulation of mucoid vacuoles among tendon fibers which may coalesce to form interstitial tears [152]. Less common causes of Achilles tendinosis include lipoid and ossific degeneration, describing the accumulation of fat and ossification within the tendon [152]. Degenerative ossification of the Achilles tendon occurs proximal to its insertion, in contrast with enthesopathy which occurs at the insertion [152].

Attenuated muscle strength and function were present during walking as long as 2 to 5 years after rupture, as determined by 3-dimensional gait analysis [6]. One year after Achilles tendon rupture, walking was characterized by increased gastrocnemius muscle activation and reduced ankle sagittal joint excursion compared with the unaffected side [129]. Findings one year after acute unilateral Achilles tendon rupture suggest altered tendon mechanics with compensatory shifts toward biarticular muscle activation, reduced activation variability, and redistribution of joint power along the limb [13]. Neuromechanical activation of triceps surae muscle remains altered at 3.5 years following open surgical repair of acute Achilles tendon rupture [170]. At 3.5 years following open Achilles tendon repair, complex neuromuscular changes manifest to produce maximum force output whilst protecting the previously injured tendon [170]. At one year postoperatively, patients with chronic Achilles tendon rupture still exhibit impairments in spatiotemporal variables and knee and ankle power compared with healthy controls [94]. Greater calf muscle endurance, especially heel-rise total work, is moderately correlated to better ankle biomechanics during gait in patients surgically treated for chronic Achilles tendon rupture [78]. Minimizing tendon elongation and regaining heel-rise height may be important for the long-term recovery of ankle biomechanics, particularly during more demanding activities such as jumping [139]. Increased knee flexion seemed to be a compensatory strategy for decreased ankle plantarflexion after surgically repaired acute Achilles tendon rupture [104]. Except for a slight delay in heel lift-off, kinematics during walking were symmetrical between the injured and healthy leg 4.5 years after non-surgical treatment, even with a 1.7 cm elongated tendon [119]. Differential elongation of the gastrocnemius tendon can abolish knee-ankle coupling and lead to unrecognized elongation despite apparent tendon approximation [145]. From a biomechanical point of view, at 1 year after surgery Achilles tendons did not show a 'restitutio ad integrum' [156]. Several angular foot alignment parameters differed between individuals with Achilles tendon rupture and healthy controls [136].

Classification

Anatomical Location: Achilles tendon disorders are broadly classified into insertional and non-insertional conditions based on anatomical location [16]. Insertional Achilles tendinopathy is defined as symptoms localised within the first 2 cm of the attachment of the Achilles tendon to the calcaneus [38]. Midportion Achilles tendinopathy is defined as symptoms localised more than 2 cm above the distal attachment [38], specifically located 2–7 cm from the insertion onto the calcaneus [161]. The distinction between insertional and midportion Achilles tendinopathy is justified by differences in prognosis during non-surgical treatment [38].

Imaging-Based Classifications: An MRI-based classification system offers a reliable method for identifying the anatomical location of Achilles tendon ruptures [46]. An AT tear classification system demonstrated substantial to almost perfect reliability [127]. Ultrasound imaging criteria based on the continuum model of tendon pathology demonstrated 'substantial' to 'almost perfect' intra-rater and inter-rater reliability for staging Achilles tendinopathy [134]. The clinical diagnosis of Achilles tendinopathy does not require the presence of structural changes shown on ultrasound imaging [134].

Histological Classification: Histological degenerative changes in Achilles tendinopathy can be classified as hypoxic degeneration, hyaline degeneration, mucoid or myxoid degeneration, fibrinoid degeneration, fatty degeneration, calcification, or fibrocartilaginous or osseous metaplasia [26].

Other Considerations: Nonruptured Achilles tendons and ruptured Achilles tendons are clearly part of two distinct populations [17]. There were no significant differences in the mean pathologic sum-scores in tendon samples taken proximally and distal to the site of rupture [7].

Clinical Presentation

Epidemiology and Risk Factors

Achilles tendon ruptures occur most frequently in recreational male athletes in the third to fifth decades [39]. Complete rupture is usually a sequel to a sedentary lifestyle and participation in sports activities [31]. In a Finnish nationwide study, the incidence of Achilles tendon ruptures increased while the use of operative treatment decreased [37]. Age is a risk factor for contralateral tendon rupture in patients with acute Achilles tendon rupture [32]. Patients who sustain Achilles tendon rupture in their 30s have a significantly increased risk for contralateral tendon rupture [32]. Age was found to be the strongest predictor of outcome after Achilles tendon rupture [63].

Mechanism of Injury

Most ruptures occur as an indirect loading mechanism during eccentric muscle contracture [39]. Most Achilles tendon ruptures share characteristic injury features, that is, Achilles tendon elongation, closed-chain movements, and sudden loading [19].

Anatomical Location

Seventy-five percent of ruptures occur between 5 and 6 cm proximal to the insertion on the calcaneal tuberosity [39]. The location of 75% of ruptures correlates to a zone of relative hypovascularity [39].

History and Symptoms

Patients typically report a sensation of being kicked or shot in the leg despite no contact occurring to the tendon [39]. A subgroup of patients with an acute rupture have antecedent pain at the Achilles [39]. Eight patients (12.1%) reported prodromal symptoms of tendinosis before their injury in a cohort of 66 patients with clinically diagnosed complete rupture [25].

Physical Examination

Physical examination reveals a decreased resting tension compared with the contralateral side [39]. Plantar flexion weakness is present with recruitment of toe flexors to substitute for the power of the gastrocnemius-soleus complex [39]. A palpable gap is present at the site of the rupture [39]. Thompson testing is positive, indicating the absence of passive ankle plantar flexion upon calf squeeze with the patient positioned prone [39]. Thompson testing is highly sensitive (96%) and specific (93%) for a complete acute Achilles rupture [39].

Diagnostic Imaging

The diagnosis of a suspected Achilles rupture is based largely on history and physical examination [39]. Diagnostic imaging is not needed in most cases, but can be useful to rule out alternative or additional injuries, confirm the diagnosis, or better define the injury for preoperative planning purposes, especially in cases of delayed or unclear diagnosis [39]. MRI and ultrasonography can both be used to confirm an Achilles tendon rupture in the case of ambiguous physical examination findings but are not routinely necessary [39]. MRI and ultrasonography may be helpful to localize the level of an acute rupture, identify any underlying tendinosis at the site of the rupture, and quantify gapping of tendon ends [39].

Classification and Chronicity

Achilles ruptures must be divided into acute versus chronic; the distinction is most commonly described as 4 to 6 weeks [39]. Chronic ruptures are often the result of missed initial diagnosis, which can occur in up to 25% of cases [39].

Histopathology

Nonruptured Achilles tendons, even at an advanced age, and ruptured Achilles tendons are clearly part of two distinct populations [17]. The pathological features were significantly more pronounced in the samples taken from the site of rupture than in the samples taken proximally and distal to it [7]. There were no significant differences in the mean pathologic sum-scores in the samples taken proximally and distal to the site of rupture [7]. Ruptured Achilles tendons demonstrate histopathological evidence of failed healing response even in areas macroscopically intact [7].

Investigations

Clinical Examination

The physical examination for acute Achilles tendon rupture should include two or more of the following tests: the Clinical Thompson test (Simmonds squeeze test), decreased ankle plantar flexion strength, presence of a palpable gap, or increased passive ankle dorsiflexion with gentle manipulation [126]. Examination typically reveals decreased resting tension compared with the contralateral side, plantar flexion weakness with recruitment of toe flexors to substitute for the power of the gastrocnemius-soleus complex, and a palpable gap at the site of the rupture [39]. The absence of ankle plantar flexion is not a reliable sign for Achilles tendon rupture [184]. The diagnostic triad of gap, posture, and calf squeeze is more sensitive than magnetic resonance imaging [184]. Clinical diagnosis of Achilles tendon tear is certain when the knee flexion and calf squeeze tests are positive, making imaging superfluous in such instances [186].

Imaging

Routine use of magnetic resonance imaging, ultrasound, and radiography to confirm the diagnosis of acute Achilles tendon rupture has an Inconclusive strength of recommendation [126]. Diagnostic imaging is not needed in most cases of suspected Achilles rupture but can be useful to rule out alternative or additional injuries, confirm the diagnosis, or better define the injury for preoperative planning purposes, especially in cases of delayed or unclear diagnosis [39]. MRI is unnecessary for diagnosing acute Achilles tendon ruptures when clinical diagnostic criteria are met [25].

MRI: MRI and ultrasonography may be helpful to localize the level of an acute rupture, identify any underlying tendinosis at the site of the rupture, and quantify gapping of tendon ends, which may influence treatment [39]. The MRI-based classification system offers a reliable method for identifying the anatomical location of Achilles tendon ruptures [46]. One study systematically mapped the location and morphology of Achilles tendon stumps via magnetic resonance imaging [172]. Intra-tendon MRI abnormalities are frequent in chronic Achilles tendon rupture but likely represent non-pathologic cicatricial remodeling [181]. Interposed tissue between the tendon stumps is suitable for repair of chronic Achilles tendon rupture if preoperative MRI shows a thickened fusiform-shaped Achilles tendon with diffuse intratendinous high-signal alterations throughout [173]. MRI-derived measures of Achilles tendon fat content may be able to distinguish xanthomas from control and tendinopathic tissue [182]. There was no statistically significant difference in favor of one imaging modality over the others for the diagnosis of Achilles tendinopathy, but MRI revealed the highest overall diagnostic accuracy for the diagnosis of both insertional and midportion Achilles tendinopathy [148]. The roles of ultrasonography and magnetic resonance imaging during the healing process after Achilles tendon rupture are limited due to a weak correlation with clinical findings [114].

Ultrasound: Greater Achilles tendon cross-sectional area seen on ultrasound 6 weeks after surgical repair had good clinical prediction for long-term functional outcome [65]. Tendon structure assessed by ultrasound imaging changes over the first 24 weeks of healing after Achilles tendon rupture, suggesting it could be used as a biomarker to track tendon healing early in recovery [180]. In symptomatic, tendinopathic Achilles tendons, the ultrasonographic tendon structure improved during nonoperative treatment and normalized after 24 weeks to values of matched asymptomatic controls [174].

Other Considerations: Magnetic resonance imaging techniques can be used as an adjunct to clinical evaluation by monitoring morphologic effects in clinical treatment studies of Achilles tendinopathy [109]. Pathological features were significantly more pronounced in the samples taken from the site of rupture than in the samples taken proximally and distal to it [7].

Treatment

Non-Operative

Non-operative management of acute Achilles tendon rupture utilizing an accelerated rehabilitation programme may produce comparable results with fewer adverse events than operative treatment [89]. Seventeen years of experience with a nonoperative treatment protocol confirmed good functional outcome and patient satisfaction [10]. The overall rerupture rate in a study of nonoperative management was low, supporting the continued use of initial nonoperative management for the treatment of acute Achilles tendon ruptures [86]. In adults with acute Achilles tendon rupture, nonoperative treatment, open repair, and minimally invasive surgery did not differ for health status at 12 months [102]. No clinically relevant difference was found between operative and non-operative treatment in tendon elongation measured with the Achilles tendon resting angle (ATRA) 1 year after acute Achilles tendon rupture [107]. Both nonoperative and operative management of myotendinous Achilles tendon ruptures demonstrated good outcomes after injury [27].

Regarding weight-bearing, early weight-bearing did not influence outcome 4.5 years after nonoperative treatment of acute Achilles tendon rupture [69]. Immediate weight-bearing can be recommended as an option in the nonoperative treatment of Achilles tendon rupture [117]. However, attenuated muscle strength and function were present during walking as long as 2 to 5 years after rupture, as determined by 3-dimensional gait analysis in patients treated nonsurgically [6].

Platelet-rich plasma (PRP) injections have not demonstrated benefit. In nonsurgically managed acute Achilles tendon rupture, 4 PRP injections did not improve function and healing compared with placebo over 12 months [95]. PRP injection did not improve patient-reported function or quality of life two years after acute Achilles tendon rupture compared with placebo [105].

Operative

Indications: Open surgical repair of acute Achilles tendon ruptures significantly reduces the risk of reruptures when compared with nonoperative management [100]. However, operative management of adolescent Achilles tendon ruptures is associated with significantly higher rates of failed management (5.2% vs 0.19%) and overall complications compared to nonoperative treatment [110].

Surgical Approach / Technique: The results of surgical treatment for ruptured Achilles tendon are good overall [101]. The jigless knotless internal brace technique might be a reliable option for Achilles tendon repair [120]. Specific repair techniques include the Lynn technique, which involves fanning out the plantaris tendon to form a membrane that covers the repair of the Achilles tendon [75]. The Lindholm technique involves debriding ragged tendon ends and apposing them with a box type of mattress suture, followed by twisting two flaps from the proximal tendon and gastrocnemius aponeurosis 180 degrees to cover the site of rupture [75].

Other Considerations: Tissue expansion is recommended as an excellent way to avoid skin healing problems in complicated Achilles tendon ruptures, particularly for missed total ruptures where skin closure is difficult [122].

Comparative Outcomes and Guidelines

There is a large body of evidence addressing treatment of acute and chronic Achilles tendon ruptures; however, controversy remains [2]. There is no consensus on which is the best treatment for Achilles tendon ruptures, and their management is still controversial [52]. Limited scientific evidence is available for optimized rehabilitation regimen and on the course of recovery after Achilles tendon ruptures [52]. There are no universally accepted outcomes regarding the return to play process after Achilles tendon rupture [52].

The AAOS work group on the diagnosis and treatment of acute Achilles tendon rupture made 16 recommendations, none of which was graded as strong; most are graded inconclusive, four are graded weak, two are graded as moderate strength, and two are consensus statements [48]. The two moderate-strength AAOS recommendations include suggestions for early postoperative protective weight bearing and for the use of protective devices that allow for postoperative mobilization [48]. A guideline serves as a valuable resource for physicians when making decisions regarding the surgical treatment of patients with chronic Achilles tendon rupture [12].

It is possible to implement a standardised treatment protocol to guide the decision-making and treatment of an acute Achilles tendon rupture as part of daily care in a large standard trauma hospital [92]. The dissemination of results from a landmark trial comparing surgical and non-operative management led to a statistically significant decrease in the rate of surgical repair for acute Achilles tendon ruptures in Ontario within one year of the trial's presentation [90]. Females present larger deficit in heel-rise height at 3 months following an Achilles tendon rupture compared with males, highlighting the importance of an individualised treatment [29].

Complications

Rerupture and Tendon Integrity: Operative treatment of Achilles tendon ruptures decreases rerupture rates compared with non-operative treatment [35, 36]. Re-rupture is the most important postoperative complication in Achilles tenorrhaphy, though it is quite uncommon using the open technique [149]. Percutaneous and minimally invasive techniques of repair yielded no reruptures at a minimum follow-up of 24 months [23].

Wound and Infection Complications: Operative treatment increases the risk for minor complications when compared to non-operative treatment [35, 36]. The overall functional outcome of open repair is associated with a high complication rate, mainly due to wound problems and infection [62]. Classic tenorrhaphies have a high incidence of soft tissue damage, which occurs in 20% of cases [149]. Modern minimally invasive repairs offer reduced risk of iatrogenic sural nerve problems compared to open techniques [162].

Long-Term Functional Deficits and Biomechanical Changes: The time to recover full function after an Achilles tendon rupture is at least 12 months [30]. Continued deficits in calf muscle endurance and strength remained 7 years after rupture [58]. The healed Achilles tendon has inferior elastic properties even after a long-term healing phase [66]. Tendon elongation in the free tendon is evident in patients with and without persistent muscle weakness following an Achilles tendon rupture [33]. Findings suggest altered tendon mechanics with compensatory shifts toward biarticular muscle activation, reduced activation variability, and redistribution of joint power along the limb one year after acute unilateral Achilles tendon rupture [13].

Pathological and Histological Findings: Patients with a history of Achilles tendon rupture appear to have elevated levels of MMP-2, MMP-7 and TIMP-2 in serum [76].

Risk Factors for Complications and Recurrence: A positive family history is a significant solitary risk factor for Achilles tendinopathy, increasing the risk fivefold [155]. Patients with acute Achilles tendon rupture undergoing operation within 48 hours after injury had a lower number of adverse events compared with patients undergoing operation after 72 hours [18].

Recovery

Light activity (weeks): The provided evidence does not specify a typical week range for light activities such as desk work, driving, or light ADLs.

Full activity (months): The provided evidence does not specify a typical month range for the return to manual work, sport, or full ROM/strength.

Complete recovery / outcome plateau (months): The provided evidence does not specify a typical month range for when pain, strength, and final functional outcomes stabilise.

Rehabilitation protocol: Early ankle range of motion improves without the risk of Achilles tendon elongation and without altering long-term functional outcome following functional weight-bearing mobilization [41]. There appears to be no difference between surgical and non-surgical groups regarding the importance of controlled early motion in the treatment of ruptured Achilles tendon [79]. After the 11-year follow-up, early mobilization and immobilization in tension after Achilles rupture repair resulted in similar clinical outcomes and isokinetic strengths [125].

Functional milestones: The provided evidence does not report specific validated PROM trajectories or outcome-measure benchmarks (e.g., Constant, ASES, WOMAC) for functional milestones.

Other Considerations: Most elite soccer players take 1 year to reach peak match participation after an Achilles tendon rupture [190]. The ruptured Achilles tendon elongates for 6 months after surgical repair regardless of early or late weightbearing in combination with ankle mobilization [30]. The overall functional outcome of open repair of Achilles tendon ruptures is rather good, however associated with a high complication rate, mainly due to wound problems and infection [62]. DVT during immobilization affects patients' long-term functional outcomes 3 years after Achilles tendon rupture repair [121]. Percutaneous repair of neglected Achilles rupture using the index technique proved a satisfactory patient-reported and objective measurement at a one-year follow-up [24].

Key Evidence

• [L4] Surgical intervention gave superior patient reported outcome compared with non-surgical treatment for patients affected by a chronic Achilles tendon rupture. [1] (10.1186/s12891-026-09890-y)
• [L5] There is a large body of evidence addressing treatment of acute and chronic Achilles tendon ruptures; however, controversy remains. [2] (10.2106/jbjs.o.00002)
• [L4] Open end-to-end repair of acute Achilles tendon ruptures provides long-term functional outcomes with consistent good to excellent results. [3] (10.1016/j.injury.2006.06.005)
• [L1] The majority of patients with an Achilles tendon rupture have not fully recovered 2 years after injury regardless of surgical or non-surgical treatment, with only minor improvements occurring between the 1- and 2-year evaluations. [4] (10.1007/s00167-011-1511-3)
• [L3] Patients presenting more than 2 weeks after Achilles tendon rupture may be successfully treated with minimally invasive repair. [5] (10.1007/s00167-018-5340-5)
• [L3] Attenuated muscle strength and function were present during walking as long as 2 to 5 years after rupture, as determined by 3-dimensional gait analysis. [6] (10.1177/2325967113504734)
• [L4] [7] (10.1007/s00167-010-1193-2)
• [L4] Long-term outcome after minimally invasive Achilles tendon rupture repair is excellent. [8] (10.1177/0363546510392012)
• [L5] AAOS recommendations on the management of Achilles tendon rupture range from Inconclusive to Moderate, with further studies needed for stronger recommendations. [9] (10.5435/00124635-201008000-00008)
• [L4] Seventeen years of experience with a nonoperative treatment protocol for acute rupture of the Achilles tendon confirmed good functional outcome and patient satisfaction. [10] (10.1177/0363546515623501)
• [L1] The guideline serves as a valuable resource for physicians when making decisions regarding the surgical treatment of patients with chronic Achilles tendon rupture. [12] (10.1186/s13018-024-04559-5)
• [L3] Findings suggest altered tendon mechanics with compensatory shifts toward biarticular muscle activation, reduced activation variability, and redistribution of joint power along the limb. [13] (10.1016/j.jisako.2026.101198)
• [L5] [16] (10.1302/0301-620x.95b10.31881)
• [L4] Nonruptured Achilles tendons, even at an advanced age, and ruptured Achilles tendons are clearly part of two distinct populations. [17] (10.1177/03635465000280061401)
• [L3] Patients with acute Achilles tendon rupture undergoing operation within 48 hours after injury had better outcomes and a lower number of adverse events compared with patients undergoing operation after 72 hours. [18] (10.1177/0363546518793655)
• [L4] Most Achilles tendon ruptures share characteristic injury features, that is, Achilles tendon elongation, closed-chain movements, and sudden loading. [19] (10.1177/2325967123s00320)
• [L3] Patients with Achilles tendon rupture treated by percutaneous repair 14 to 30 days after injury achieved similar results at 1 year as patients treated within 14 days after injury. [21] (10.1177/0363546520908592)
• [L3] The percutaneous and minimally invasive techniques of repair of the Achilles tendon yielded essentially identical clinical and functional outcomes with no reruptures or major complications observed at a minimum follow-up of 24 months. [23] (10.1097/blo.0b013e3180396f07)
• [L4] Percutaneous repair of neglected Achilles rupture using the index technique proved a satisfactory patient-reported and objective measurement at a one-year follow-up. [24] (10.1186/s12891-023-06561-0)
• [L2] [25] (10.1007/s11999-012-2355-y)
• [L5] [26] (10.2106/00004623-200211000-00024)
• [L1] Both nonoperative and operative management of myotendinous Achilles tendon ruptures demonstrated good outcomes after injury, although there is a limited amount of literature on this topic. [27] (10.1186/s12891-025-08286-8)
• [L4] Surgical treatment of Achilles tendon ruptures achieved excellent or good outcomes in 91% of patients. [28] (10.1007/s004020050410)
• [L2] Through this knowledge, we highlighted the importance of an individualised treatment for acute Achilles tendon ruptures with better outcome for both males and females. [29] (10.1002/ksa.12208)
• [L1] The time to recover full function after an Achilles tendon rupture is at least 12 months. [30] (10.1177/0363546518781826)
• [L4] Complete rupture of the Achilles tendon is usually a sequel to a sedentary life-style and participation in sports activities. [31] (10.1177/036354658901700305)
• [L3] Patients who sustain Achilles tendon rupture in their 30s have significantly increased risk for contralateral tendon rupture. [32] (10.1007/s00167-019-05380-y)
• [L4] Tendon elongation in the free tendon is evident in patients with and without persistent muscle weakness following an Achilles tendon rupture. [33] (10.1002/ksa.70445)
• [L1] Operative treatment of Achilles tendon ruptures decreases rerupture rates but increases the risk for minor complications when compared to non-operative treatment. [35] (10.1177/2325967115s00146)
• [L3] Operative treatment of Achilles tendon ruptures decreases rerupture rates but increases the risk for minor complications when compared with nonoperative treatment. [36] (10.1177/2325967115579188)
• [L4] The incidence of Achilles tendon ruptures increased and the use of operative treatment decreased. [37] (10.1177/23259671221131536)
• [Paper] [38] (10.1136/bjsports-2020-103867)
• [L1] In addition, early ankle range of motion was improved without the risk of Achilles tendon elongation and without altering long-term functional outcome. [41] (10.1007/s00167-016-4270-3)
• [L4] [43] (10.1136/bjsports-2017-098161)
• [L3] The MRI-based classification system offers a reliable method for identifying the anatomical location of Achilles tendon ruptures. [46] (10.1177/2325967126s00272)
• [L1] [48] (10.5435/00124635-201008000-00007)
• [L3] Results indicated no differences in reoperation rates between operative and nonoperative management of Achilles tendon ruptures. [49] (10.1177/23259671231152904)
• [L4] It is an efficient, reliable, and safe method for acute Achilles tendon rupture. [50] (10.1186/s13018-020-01776-6)
• [L5] [52] (10.3390/jfmk5040095)
• [L3] [55] (10.1007/s00167-018-5172-3)
• [L2] Continued deficits in calf muscle endurance and strength remained 7 years after Achilles tendon rupture. [58] (10.1177/0363546517737055)
• [L1] Operative treatment of ruptured Achilles tendons is preferable, but nonoperative treatment is an acceptable alternative. [60] (10.1177/036354659302100606)
• [L3] The overall functional outcome of open repair of Achilles tendon ruptures is rather good, however associated with a high complication rate, mainly due to wound problems and infection. [62] (10.1016/j.injury.2018.08.012)
• [L3] Age was found to be the strongest predictor of outcome after Achilles tendon rupture. [63] (10.1177/2325967120909556)
• [L2] Greater Achilles tendon cross-sectional area seen on ultrasound 6 weeks after surgical repair had good clinical prediction for long-term functional outcome. [65] (10.1177/23259671231205326)
• [L3] This study shows that the healed Achilles tendon after rupture has inferior elastic properties even after a longterm healing phase. [66] (10.1007/s00167-017-4791-4)
• [L2] Early weight-bearing did not influence outcome 4.5 years after nonoperative treatment of acute Achilles tendon rupture. [69] (10.1007/s00167-018-5058-4)
• [L4] Patients with a history of Achilles tendon rupture appear to have elevated levels of MMP-2, MMP-7 and TIMP-2 in serum. [76] (10.1136/bjsm.2008.049411)
• [L4] Greater calf muscle endurance, especially heel-rise total work, is moderately correlated to better ankle biomechanics during gait in patients surgically treated for chronic Achilles tendon rupture. [78] (10.1007/s00167-022-06987-4)
• [L1] There appears to be no difference between the 2 groups, suggesting that controlled early motion is the important part of treatment of ruptured Achilles tendon. [79] (10.1177/0363546507307503)
• [L1] The overall rerupture rate in this study was low, supporting the continued use of initial nonoperative management for the treatment of acute Achilles tendon ruptures. [86] (10.2106/jbjs.m.00248)
• [L1] This study suggests that non-operative management of Achilles tendon ruptures utilizing an accelerated rehabilitation programme may produce comparable results with fewer adverse events. [89] (10.1016/j.arthro.2009.04.065)
• [L3] The dissemination of results from a landmark trial comparing surgical and non-operative management led to a statistically significant decrease in the rate of surgical repair for acute Achilles tendon ruptures in Ontario within one year of the trial's presentation. [90] (10.1302/0301-620x.99b12.bjj-2017-0465.r1)
• [L3] The study showed that it is possible to implement a standardised treatment protocol to guide the decision-making and treatment of an acute Achilles tendon rupture as part of daily care in a large standard trauma hospital. [92] (10.1007/s00402-018-2940-y)
• [L3] However, at one year postoperatively, patients still exhibit impairments in spatiotemporal variables and knee and ankle power compared with healthy controls. [94] (10.1186/s13018-022-02948-2)
• [L1] In nonsurgically managed acute Achilles tendon rupture, 4 PRP injections did not improve function and healing compared with placebo over 12 months. [95] (10.2106/jbjs.21.00242)
• [L1] Open surgical repair of acute Achilles tendon ruptures significantly reduces the risk of reruptures when compared with nonoperative management. [100] (10.1177/0363546512453293)
• [L4] The results of surgical treatment for ruptured Achilles tendon are good overall. [101] (10.1016/j.otsr.2013.03.024)
• [L1] In adults with acute Achilles tendon rupture, nonoperative treatment, open repair, and minimally invasive surgery did not differ for health status at 12 months. [102] (10.2106/jbjs.22.00965)
• [L2] Increased knee flexion seemed to be a compensatory strategy for decreased ankle plantarflexion. [104] (10.1177/03635465221129284)
• [L1] PRP injection did not improve patient-reported function or quality of life two years after acute Achilles tendon rupture compared with placebo. [105] (10.1302/0301-620x.104b11.bjj-2022-0653.r1)
• [L3] [107] (10.1007/s00167-020-06391-w)
• [L4] Magnetic resonance imaging techniques can be used as an adjunct to clinical evaluation by monitoring morphologic effects in clinical treatment studies of Achilles tendinopathy. [109] (10.1177/0363546504263148)
• [L3] Operative management of adolescent Achilles tendon ruptures is associated with significantly higher rates of failed management (5.2% vs 0.19%) and overall complications compared to nonoperative treatment, despite a lower incidence of nerve injury in the operative group. [110] (10.1177/2325967125s00282)
• [L1] The roles of ultrasonography and magnetic resonance imaging during the healing process after Achilles tendon rupture are limited, due to a weak correlation with clinical findings. [114] (10.1007/s001670100245)
• [L1] Immediate weight-bearing can be recommended as an option in the nonoperative treatment of Achilles tendon rupture. [117] (10.2106/jbjs.m.01273)
• [L2] Except for a slight delay in heel lift-off, kinematics during walking were symmetrical between the injured and healthy leg, even with an elongated tendon. [119] (10.1007/s00167-022-06874-y)
• [L3] It might be a reliable option for Achilles tendon repair. [120] (10.1186/s13018-019-1471-8)
• [L3] DVT during immobilization affects patients' long-term functional outcomes 3 years after Achilles tendon rupture repair. [121] (10.1002/ksa.12240)
• [L4] The author recommends tissue expansion as an excellent way to avoid skin healing problems in complicated Achilles tendon ruptures, particularly for missed total ruptures where skin closure is difficult. [122] (10.1007/s001670100221)
• [L4] The most common mechanism of injury is taking off from a stopped position just before toe-off in a dorsiflexed foot. [123] (10.1177/0363546519858609)
• [L1] After the 11-year follow-up, early mobilization and immobilization in tension after Achilles rupture repair resulted in similar clinical outcomes and isokinetic strengths. [125] (10.1177/0363546515591267)
• [L3] This study introduces an AT tear classification system that demonstrated substantial to almost perfect reliability. [127] (10.1177/23259671261428092)
• [L2] There appears to be a clinically important difference in the risk of complications between minimally invasive surgical treatment and nonoperative treatment for acute Achilles tendon ruptures, but this was not statistically significant. [128] (10.1177/0363546508319312)
• [L4] One year after Achilles tendon rupture, walking was characterized by increased gastrocnemius muscle activation and reduced ankle sagittal joint excursion compared with the unaffected side. [129] (10.1186/s13018-025-06221-0)
• [L5] For acute Achilles tendon rupture, studies suggest equivalent functional outcomes with or without surgical treatment provided a functional rehabilitation program is followed; in such situations of clinical equipoise, shared decision-making provides a useful framework for the discussion of treatment options, supporting the autonomy of the patient as they weigh the risks and benefits of their treatment options. [132] (10.2106/jbjs.19.00144)
• [L4] [134] (10.1136/bmjsem-2019-000699)
• [L3] Several angular foot alignment parameters differed between individuals with Achilles tendon rupture and healthy controls. [136] (10.1186/s12891-026-09658-4)
• [L5] Results highlighted with an unprecedented level of detail the traditionally overlooked multiplanar nature of the injury biomechanics preceding an ATR, which might play a substantial role in triggering the tendon failure. [137] (10.1007/s00167-022-07078-0)
• [L3] Minimizing tendon elongation and regaining heel-rise height may be important for the long-term recovery of ankle biomechanics, particularly during more demanding activities such as jumping. [139] (10.1177/0363546517717698)
• [L5] This differential elongation can abolish knee-ankle coupling and lead to unrecognized elongation despite apparent tendon approximation. [145] (10.1007/s00167-021-06580-1)
• [L2] There was no statistically significant difference in favor of one imaging modality over the others, but MRI revealed the highest overall diagnostic accuracy for the diagnosis of both insertional and midportion Achilles tendinopathy. [148] (10.1177/23259671211006826)
• [L3] [149] (10.1016/j.injury.2016.09.009)
• [L3] This cross-sectional study identified a positive family history as a significant solitary risk factor for Achilles tendinopathy, increasing the risk fivefold. [155] (10.1007/s00402-012-1476-9)
• [L3] From a biomechanical point of view, at 1 year after surgery Achilles tendons did not show a 'restitutio ad integrum'. [156] (10.1007/s00167-014-3484-5)
• [L3] [161] (10.1007/s00167-012-2203-3)
• [L5] [162] (10.1186/s13018-026-06685-8)
• [L4] The study described basketball-specific movement patterns among NBA players who sustained Achilles tendon ruptures, supporting observations of forefoot loading and rapid ankle dorsiflexion while introducing new concepts regarding proximal lower limb extension and musculotendinous complex elongation. [169] (10.1002/ksa.70249)
• [L3] The results provide evidence on neuromuscular changes 3.5 years following open Achilles tendon repair, where complex changes manifest to produce maximum force output whilst protecting the previously injured tendon. [170] (10.1007/s00167-021-06512-z)
• [L4] This study is the first to systematically map the location and morphology of Achilles tendon stumps via magnetic resonance imaging. [172] (10.1186/s12891-026-09795-w)
• [L4] Interposed tissue between the tendon stumps is suitable for repair of chronic Achilles tendon rupture if preoperative MRI shows a thickened fusiform-shaped Achilles tendon with diffuse intratendinous high-signal alterations throughout. [173] (10.1177/0363546506295939)
• [L2] In symptomatic, tendinopathic Achilles tendons, the ultrasonographic tendon structure improved during nonoperative treatment and normalized after 24 weeks to values of matched asymptomatic controls. [174] (10.1177/0363546515605077)
• [L5] The exact aetiology and pathophysiology of non-insertional Achilles tendinopathy are not fully known and warrant further studies. [175] (10.1136/jisakos-2017-000164)
• [L2] Tendon structure assessed by ultrasound imaging changes over the first 24 weeks of healing after Achilles tendon rupture, suggesting it could be used as a biomarker to track tendon healing early in recovery. [180] (10.1007/s00167-018-5277-8)
• [L4] Complications correlate with age, and intra-tendon MRI abnormalities are frequent but likely represent non-pathologic cicatricial remodeling. [181] (10.1016/j.otsr.2013.03.021)
• [L4] MRI-derived measures of Achilles tendon fat content may be able to distinguish xanthomas from control and tendinopathic tissue. [182] (10.1186/s12891-021-04494-0)
• [Letter] The absence of ankle plantar flexion is not a reliable sign for Achilles tendon rupture, and the diagnostic triad of gap, posture, and calf squeeze is more sensitive than magnetic resonance imaging. [184] (10.1016/j.arthro.2025.07.007)
• [Letter] Clinical diagnosis of Achilles tendon tear is certain when the knee flexion and calf squeeze tests are positive, making imaging superfluous in such instances. [186] (10.1016/j.arthro.2025.07.010)
• [L4] Most players take 1 year to reach peak match participation after an Achilles tendon rupture. [190] (10.1007/s00167-022-07082-4)

See Also

• Achilles tendinopathy
• Achilles tendon repair

References

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