Regional variations in incidence and treatment trends of Achilles tendon ruptures in Finland: a nationwide study.

BACKGROUND AND PURPOSE: The aim of our study was to assess the regional variations in Achilles tendon rupture incidence and treatment methods in Finland during the period 1997-2019. METHODS: The Finnish National Hospital Discharge Register (NHDR) and the Finnish Register of Primary Health Care Visits (PHCR) were searched to identify all adult patients diagnosed with Achilles tendon rupture during our study period. The population-based annual incidence and incidences of surgically and non-surgically treated Achilles tendon ruptures were calculated for each hospital district. RESULTS: Achilles tendon rupture incidence increased from 17.3 per 105 person-years in 1997 to 32.3 per 105 in 2019. The mean incidence of Achilles tendon ruptures ranged from 26.4 per 105 (North Savo) to 37.2 per 105 (Central Ostrobothnia). The incidence of Achilles tendon ruptures increased in all areas. The proportion of non-surgical treatment of Achilles tendon ruptures ranged in 1997 from 7% (Vaasa) to 67% (Åland) and in 2019 from 73% (Southwest Finland) to 100% (East Savo, Kainuu, Länsi-Pohja, Åland). During the study period, a shift towards non-surgical treatment was evident in all hospital districts. CONCLUSION: Regional variations in Achilles tendon rupture incidence exist in Finland; however, the incidence increased in all areas during the follow-up period. More Achilles tendon rupture patients are currently being treated non-surgically throughout the country.

Early Predictors of Recovery From Nonoperatively Treated Achilles Tendon Rupture: 1 Year Follow-Up Study.

PURPOSE: To investigate early structural and mechanical predictors of plantarflexor muscle strength and the magnitude of Achilles tendon (AT) nonuniform displacement at 6 and 12 months after AT rupture. METHODS: Thirty-five participants (28 males and 7 females; mean ± SD age 41.7 ± 11.1 years) were assessed for isometric plantarflexion maximal voluntary contraction (MVC) and AT nonuniformity at 6 and 12 months after rupture. Structural and mechanical AT and plantarflexor muscle properties were measured at 2 months. Limb asymmetry index (LSI) was calculated for all variables. Multiple linear regression was used with the 6 and 12 month MVC LSI and 12 month AT nonuniformity LSI as dependent variables and AT and plantarflexor muscle properties at 2 months as independent variables. The level of pre- and post-injury sports participation was inquired using Tegner score at 2 and 12 months (scale 0-10, 10 = best possible score). Subjective perception of recovery was assessed with Achilles tendon total rupture score (ATRS) at 12 months (scale 0-100, 100=best possible score). RESULTS: Achilles tendon resting angle (ATRA) symmetry at 2 months predicted MVC symmetry at 6 and 12 months after rupture (ß = 2.530, 95% CI 1.041-4.018, adjusted R2 = 0.416, p = 0.002; ß = 1.659, 95% CI 0.330-2.988, adjusted R2 = 0.418, p = 0.016, respectively). At 12 months, participants had recovered their pre-injury level of sports participation (Tegner 6 ± 2 points). The median (IQR) ATRS score was 92 (7) points at 12 months. CONCLUSION: Greater asymmetry of ATRA in the early recovery phase may be a predictor of plantarflexor muscle strength deficits up to 1 year after rupture. TRIAL REGISTRATION: This research is a part of "nonoperative treatment of Achilles tendon rupture in Central Finland: a prospective cohort study" that has been registered in ClinicalTrials.gov (NCT03704532).

[Treatment of Injuries to the Posterior Cruciate Ligament]. / Therapie von Verletzungen des hinteren Kreuzbandes.

Compared to the anterior cruciate ligament injury, the rupture of the posterior cruciate Ligament (PCL) is the rarer condition. A high healing potential is attributed to the PCL in the literature, which is why conservative therapy is also considered important in addition to surgical treatment 1. Posterior cruciate ligament rupture is often associated with concomitant injuries. Among other things, up to 70% of cases are associated with accompanying injuries to the posterolateral corner 2. The detection of concomitant injuries has a significant influence on the outcome, as isolated surgical PCL stabilization does not lead to satisfactory results in these cases.

Delayed Diagnosis of Complete Achilles Tendon Rupture in a Teenage Athlete: A Case Report of Nonoperative Treatment.

CASE: A 19-year-old female athlete experienced calf pain during sport. A complete Achilles tendon rupture was diagnosed 4 weeks after injury. Ultrasound revealed discontinuity of the Achilles tendon with 2.0 cm of diastasis, persisting in plantarflexion. Plantarflexion immobilization was initiated, and progressive dorsiflexion was used until 10 weeks from injury. At 1 year from injury, ankle magnetic resonance imaging revealed a contiguous tendon, the patient was pain-free, and had returned to high-level athletics with equivalent sport performance relative to her preoperative status. CONCLUSION: Certain Achilles tendon ruptures in young people may be treated nonoperatively with good clinical outcomes, even if diagnosis and immobilization are delayed and tendon diastasis persists in maximum plantarflexion.

Reverse Fragility Index Comparing Rates of Rerupture After Open Achilles Tendon Repair Versus Early Functional Rehabilitation: A Systematic Review of Randomized Controlled Trials.

BACKGROUND: Despite similar published rates of rerupture among patients treated with early functional rehabilitation and open repair for acute Achilles tendon rupture, uncertainty still exists regarding the optimal treatment modality. The reverse fragility index (RFI) is a statistical tool that provides an objective measure of the study's neutrality by determining the number of events that need to change for a nonsignificant result to be significant. PURPOSE: The purpose was to utilize the RFI to appraise the strength of neutrality of randomized controlled trials (RCTs) comparing the rerupture rates of acute Achilles tendon ruptures treated with open repair versus early functional rehabilitation. STUDY DESIGN: Systematic review; Level of evidence, 1. METHODS: A systematic review was performed including all RCTs comparing the rerupture rates after operative repair and early functional rehabilitation for acute Achilles tendon ruptures. Studies were included that explicitly used early functional rehabilitation, defined as weightbearing and exercise-based interventions initiated within 2 weeks, as compared with open repair and reported a nonsignificant difference in rerupture rates. The RFI, with rerupture as the primary outcome, was calculated for each study (significance threshold, P < .05). The RFI quantifies a study's strength of neutrality and is defined as the minimum number of event reversals necessary to change a nonsignificant result to statistically significant. RESULTS: Nine RCTs were included, with 713 patients and 46 reruptures. The median (interquartile range) rerupture rate was 7.69% (6.38%-9.64%) overall, 4.00% (2.33%-7.14%) in the operative group, and 10.00% (5.26%-12.20%) in the nonoperative group. The median RFI was 3, indicating that an outcome reversal of 3 patients was necessary to change the results from nonsignificant to statistically significant. The median number of patients lost to follow-up was 6 (3-7). Of 9 studies, 7 (77.8%) had a loss to follow-up greater than or equal to its RFI. CONCLUSION: The statistical nonsignificance of studies reporting equivalent rerupture rates in the management of acute Achilles tendon ruptures with open repair versus nonoperative management with early functional rehabilitation can be reversed by changing the outcome status of only a few patients.

Musculotendinous ruptures of the achilles tendon had greater heel-rise height index compared with mid-substance rupture with non-operative management: A retrospective cohort study.

INTRODUCTION: Achilles tendon ruptures (ATRs) may occur at varying locations with ruptures at the mid-substance (MS) of the tendon most common, followed tears at the musculotendinous (MT) junction. There is scant literature about the outcome of MT ATR. This study compared the outcome of patients with a MT ATR with patients following a MS ATR. METHODS: The diagnostic features and clinical outcome of 37 patients with a MT ATR were compared with a cohort of 19 patients with a MS ATR. Patients in both groups were managed non-operatively and received the same rehabilitation protocol with weight-bearing rehabilitation in protective functional brace. RESULTS: From February 2009 to August 2023, 556 patients presented with an ATR. Of these, 37 (6.7 â€‹%) patients were diagnosed with a MT tear. At final follow-up, at 12 months following injury, the MT group reported an Achilles tendon total rupture score (ATRS) of mean (standard deviation (SD)) of 83.6 (3.5) (95 â€‹% confidence interval (CI) 81.8, 85.4) and median (inter-quartile range (IQR)) ATRS of 86 points (78-95.5) and the MS group mean (SD) of 80.3 (8.5) (95%CI) 76.1, 80.5) and median (IQR) of 87 points (59-95) (p â€‹= â€‹0.673). Functional evaluation, however, revealed statistically significant differences in mean (SD) heel-rise height index MT group 79 â€‹% (25) (95%CI 65.9, 92.1) and MS group 59 â€‹% (13) (95%CI 51.9, 67.1) (p â€‹= â€‹0.019). In the MT rupture group, there were considerably less complications than the MS rupture group. CONCLUSIONS: When managed non-operatively, with only a 6 weeks period of brace protection, patients have little limitation although have some residual reduction of single heel-rise at the one-year following MT ATR. LEVEL OF EVIDENCE: IV.

An isolated rupture of the anterolateral ligament of the knee: A case report.

INTRODUCTION: The anterolateral ligament (ALL) is a controversial ligament in the knee that may play a significant role in knee stability. It is difficult to identify on magnetic resonance imaging (MRI) imaging and is often injured in conjunction with other ligaments, such as the anterior cruciate ligament (ACL) and medial collateral ligament. CASE PRESENTATION: This is a unique case of an isolated ALL tear in a 48-year-old woman who presented with severe left knee pain, swelling, and inability to bear weight during a yoga session. Physical examination showed swelling and tenderness at the lateral aspect of the femoral condyle, with increased pain on varus stress testing. Radiographs revealed normal osseous structures with the absence of traumatic bone lesions. MRI revealed an intact meniscus, cruciate, and collateral ligaments, but a rupture of the ALL at its femoral origin. Diagnosis of isolated ALL rupture of the left knee was made, and the patient was treated conservatively with icing, rest, and non-steroidal anti-inflammatory drugs. Physiotherapy was started 2 weeks post-injury, and return to sports was allowed at the sixth week. Upon last follow-up, the patient had excellent functional outcomes and was satisfied with the treatment. Physical examination showed a stable knee with negative Lachman and pivot shift tests. To the best of the authors' knowledge, this is the first case of isolated ALL rupture to be reported. DISCUSSION: The paper highlights the rarity of isolated ALL injuries and the difficulty in diagnosing them. Conservative treatment can be successful for isolated ALL injuries, with physiotherapy playing an essential role in rehabilitation.In conclusion, isolated ALL injuries are rare and can be challenging to diagnose. Conservative treatment with physiotherapy can lead to successful outcomes. Further research is needed to understand the role of the ALL in knee stability and to determine optimal treatment options.

The influence of the site of rupture and gap distance in acute Achilles tendon rupture treated with functional rehabilitation.

AIM: To determine the influence of gap distance and its location on clinical and radiological outcomes in patients with acute rupture of Tendo-Achilles (TA) treated non-operatively with functional rehabilitation. METHODS: Twenty-six patients with acute complete TA rupture underwent ultrasound (US) scanning within a week of their injury. The measurements taken included the distance of the rupture from the enthesis and the gap distance between the tendon edges in varying degrees of ankle and knee positions. All patients were managed non-operatively in functional weight-bearing orthoses. Nineteen patients were then followed up at a mean of 6.1 years (range 5.8-6.5) to assess their clinical and radiological outcomes. The outcomes included ultrasound assessment of tendon healing, Achilles Tendon Rupture Score (ATRS) and modified Leppilahti Score (mLS). RESULTS: In the initial ultrasound, the mean distance of the rupture from the enthesis was 52 mm (range: 40-76). The mean gap distance with the foot plantigrade was 11.4 mm, which reduced to 4.8 mm with the foot in equinus. At final follow up, no re-ruptures had occurred. The mean ATRS and mLS were 86 and 71 respectively. There was a significant correlation between the distance of the rupture from the enthesis with the MLS total score (p = 0.02), mLS Fatigue domain score (p = 0.03), and the ATRS domains of strength (p = 0.04) and fatigue (p = 0.02). There was no significant correlation between the measured gap distance with respect to the mLS, ATRS or individual ATRS domain scores. Also, there was no significant difference in ATRS and mLS outcomes when comparing tendons with respect to healed tissue appearance and fibre orientation on ultrasound. CONCLUSION: The initial gap distance had no relationship with any of the measured clinical outcomes at the final follow up. The distance of the gap from the enthesis, however, may carry a greater prognostic value following non-operative treatment of Achilles tendon injuries.

Operative versus conservative treatment of acute Achilles tendon ruptures: preliminary results of clinical outcome, kinematic MRI and contrast-enhanced ultrasound.

INTRODUCTION: There is no uniform consensus on the gold standard therapy for acute Achilles tendon rupture. The aim of this pilot study was to compare operative and conservative treatment regarding imaging findings and clinical outcome. MATERIALS AND METHODS: Surgically or conservatively treated patients with acute Achilles tendon rupture were retrospectively evaluated. Differences in tendon length and diameter with and without load were analysed using kinematic MRI, tendon perfusion, structural alterations, movement and scar tissue by means of grey-scale and contrast-enhanced ultrasound (CEUS). Intra- and interobserver agreement were recorded. RESULTS: No significant difference was detected regarding clinical outcome, B mode ultrasonography, contrast-enhanced sonography or MRI findings, although alterations in MRI-based measurements of tendon elasticity were found for both groups. Considerable elongation and thickening of the injured tendon were detected in both groups. CONCLUSION: Both, conservative and surgical treatment showed comparable outcomes in our preliminary results and may suggest non-inferiority of a conservative approach.

Platelet-rich plasma injection for acute Achilles tendon rupture : two-year follow-up of the PATH-2 randomized, placebo-controlled, superiority trial.

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.

Sex differences in patients' recovery following an acute Achilles tendon rupture - a large cohort study.

INTRODUCTION: The incidence of Achilles tendon ruptures (ATR) has increased over the past few decades. Treatment may be individualised based upon multiple factors including age, pre-injury activity level and the separation of the ruptured tendon ends. Several studies indicate that women may have a poorer self-reported and clinical outcome compared with men, but the number of women in these studies is often small due to the different incidence of ATR between the genders. AIMS: The primary aim of this study was to evaluate whether there is a difference in self-reported outcome after an acute ATR between women and men at one to five years following injury. The second aim was to compare the outcome between the surgically and non-surgically treated patients. METHODS: Data were obtained from the medical charts of patients treated for an acute ATR between 1 and 2015 and 31 December 2020 at Sahlgrenska University Hospital/Mölndal. The Achilles tendon total rupture score (ATRS) and additional questions relating to treatment and recovery were determined. A multiple regression analysis was performed to isolate the impact of sex when comparing the patient-reported outcome between women and men. RESULTS: A total of 856 patients were included of which 66% participated prospectively. Sex, BMI and age were found to be significant factors influencing the total ATRS score. Female gender resulted in a lower ATRS, 7.8 points (CI = 3.3 to 12.3), than male gender. It was found that treatment did not significantly predict the results of the ATRS. CONCLUSION: To our knowledge, this is the first report with a larger number of women included showing that female sex predicts inferior self-reported results after an acute ATR.

The Acute Achilles Tendon Rupture: An Evidence-Based Approach from the Diagnosis to the Treatment.

Background and Objective: Acute Achilles tendon rupture (AATR) is a common injury with a significant impact on daily living. Although various systematic reviews and meta-analyses have been written on the topic, no actual consensus exists on the best treatment. We aimed to collect the highest quality of evidence on the subject and to produce a document to which to refer, from the diagnosis to the final treatment. Material and Methods: Inclusion criteria were systematic reviews discussing Achilles tendon rupture, concerning either diagnostic criteria, classification, or treatment; English language; clearly stated inclusion and exclusion criteria for patients' selection. Results: Thirteen systematic reviews were included in the study. A strong consensus exists about the higher risk of re-rupture associated with non-operative treatment and a higher risk of complications associated with surgical repair. Conclusions: The combination of minimally invasive repair and accelerated functional rehabilitation seems to offer the best results in the treatment of Achilles tendon rupture.

Platelet-Rich Plasma in acute Achilles tendon ruptures: A systematic review and meta-analysis.

BACKGROUND: Platelet Rich Plasma (PRP) is known to exert multi-directional biological effects favouring tendon healing. However, conclusions drawn by numerous studies on its clinical efficacy for acute Achilles tendon rupture are limited. We performed a systematic review and meta-analysis to investigate this and to compare to those without PRP treatment. METHODS: The Cochrane Controlled Register of Trials, Pubmed, Medline and Embase were used and assessed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) criteria with the following search terms: ('plasma' OR 'platelet-rich' OR 'platelet-rich plasma' or 'PRP') AND ('Achilles tendon rupture/tear' OR 'calcaneal tendon rupture/tear' OR 'tendo calcaneus rupture/tear'). Data pertaining to biomechanical outcomes (heel endurance test, isokinetic strength, calf-circumference and range of motion), patient-reported outcome measures (PROMs) and incidence of re-ruptures were extracted. Meta-analysis was performed for same outcomes measured in at least three studies. Pooled outcome data were analysed by random- and fixed-effects models. RESULTS: After abstract and full-text screening, 6 studies were included. In total there were 510 patients of which 256 had local PRP injection and 254 without. The average age was 41.6 years, mean time from injury to treatment 5.9 days and mean follow-up at 61 weeks. Biomechanically, there was similar heel endurance, isokinetic strength, calf circumference and range of motion between both groups. In general, there were no differences in patient reported outcomes from all scoring systems used in the studies. Both groups returned to their pre-injured level at a similar time and there were no differences on the incidence of re-rupture (OR 1.13, 95% CI, 0.46-2.80, p = 0.79). CONCLUSION: PRP injections for acute Achilles tendon ruptures do not improve medium to long-term biomechanical and clinical outcomes. However, future studies incorporating the ideal application and biological composition of PRP are required to investigate its true clinical efficacy.

Calcaneal positioning in equinus immobilization of the ankle joint: A comparison of common orthoses used in the treatment of acute Achilles tendon ruptures.

Orthoses are an important part of both conservative and operative treatment of acute Achilles tendon rupture as they can be used to position the foot in equinus and protect the torn tendon from strain in the healing phase. The aim of the study was to test four different orthoses ability to position the foot in equinus. The study was performed as a cross-sectional study. 15 healthy study participants underwent radiographic examination with 11 true lateral radiographs of the right ankle and foot, one with the ankle joint in neutral position; one of a circular equinus cast (CEC); three of an adjustable equinus boot (AEB) with the foot in 30°, 15°, and 0° of plantar flexion, respectively; three of a fixed angle orthosis with 1, 2, and 3 wedges with a plateau (WWP); and three of a fixed angle orthosis with 1, 2, and 3 wedges without plateau (WWOP). The primary outcome was the Achilles Relief Distance (ARD). Secondary outcomes were the tibiocalcaneal angle (TCA), the tibiotalar angle (TTA), and the tibio- 1st metatarsal angle (1MTP). All measurements were performed by a radiologist. The mean (SD) ARD was 11 mm (7) in CEC, 23 mm (6) with 3 WWP, 11 mm (5) with 3 WWOP, and 15 mm (5) using AEB in 30° of plantarflexion. The mean (SD) TCA was 86° (7,8) in CEC, 76° (7,3) with 3 WWP, 90° (6,9) with 3 WWOP, and 84° (6,6) using the AEB in 30° of plantarflexion. CEC, AEB, and WWOP showed statistically significantly larger plantarflexion than WWP. CEC, AEB and WWOP produced significantly greater plantarflexion compared to WWP.

Observation on the Effect of Rehabilitative Physical Training on Sports Injuries under Ultrasound Image Examination.

In order to observe the effect of rehabilitative physical training on sports injuries under ultrasound examination, this study firstly carried out experiments, induction and analysis of ultrasound examination, and evaluation-related content, especially the diagnosis of ultrasound examination in muscle and tendon injuries caused by various reasons. And the clinical application of treatment (clinical research) is reviewed, in order to provide reference data for clinical stage summary. Then, by determining the fasciculation and location of the tendon rupture injury by ultrasound, the clinic can decide whether or not to proceed with surgery. Small Achilles tendon tears only require conservative treatment to avoid the development of complete Achilles tendon rupture. Finally, 26 patients and 10 healthy adults were examined by ultrasonography, and each subject was segmented to examine 11 muscles, including the tongue muscle. The bilateral trapezius, bilateral biceps brachii, bilateral abductor pollicis brevis, bilateral quadriceps femoris, and bilateral tibialis anterior muscles were evaluated by ultrasound and statistical methods. The experimental results show that if the fasciculation of the Achilles tendon injury does not reach more than 3/11, it indicates that no surgical treatment is required; for those with a complete tear of the Achilles tendon, the distance between the broken ends should be further measured in the toe flexion state to evaluate whether surgical treatment is required. It effectively solves the problem of visual diagnosis of sports injuries.

Nonoperative or Surgical Treatment of Acute Achilles' Tendon Rupture.

BACKGROUND: Whether surgical repair of an acute Achilles' tendon rupture by an open-repair or minimally invasive approach is associated with better outcomes than nonsurgical treatment is not clear. METHODS: We performed a multicenter, randomized, controlled trial that compared nonoperative treatment, open repair, and minimally invasive surgery in adults with acute Achilles' tendon rupture who presented to four trial centers. The primary outcome was the change from baseline in the Achilles' tendon Total Rupture Score (scores range from 0 to 100, with higher scores indicating better health status) at 12 months. Secondary outcomes included the incidence of tendon rerupture. RESULTS: A total of 554 patients underwent randomization, and 526 patients were included in the final analysis. The mean changes in the Achilles' tendon Total Rupture Score were -17.0 points in the nonoperative group, -16.0 points in the open-repair group, and -14.7 points in the minimally invasive surgery group (P = 0.57). Pairwise comparisons provided no evidence of differences between the groups. The changes from baseline in physical performance and patient-reported physical function were similar in the three groups. The number of tendon reruptures was higher in the nonoperative group (6.2%) than in the open-repair or minimally invasive surgery group (0.6% in each). There were 9 nerve injuries in the minimally invasive surgery group (in 5.2% of the patients) as compared with 5 in the open-repair group (in 2.8%) and 1 in the nonoperative group (in 0.6%). CONCLUSIONS: In patients with Achilles' tendon rupture, surgery (open repair or minimally invasive surgery) was not associated with better outcomes than nonoperative treatment at 12 months. (Funded by the South-Eastern Norway Regional Health Authority and Akershus University Hospital; ClinicalTrials.gov number, NCT01785264.).

Muscle-tendon morphomechanical properties of non-surgically treated Achilles tendon 1-year post-rupture.

BACKGROUND: Achilles tendon rupture appears to alter stiffness and length of the tendon. These alterations may affect the function of tendon in force transmission and in energy storage and recovery. We studied the mechanical properties of the Achilles' tendon post-rupture and their association with function. METHODS: Twenty-four (20 males, 4 females) participants (mean age: 43 y, 176 cm, 81 kg) were recruited. Ultrasonography and dynamometry were used to assess the muscle-tendon unit morphological and mechanical properties of non-surgically treated patients 1-year post rupture. FINDINGS: Injured tendons were longer with difference of 1.8 cm (95%CI: 0.5-1.9 cm; P < 0.001), and thicker by 0.2 mm (0.2-0.3 mm; P < 0.01). Medial gastrocnemius cross-sectional area was 1.0 cm2 smaller (0.8-1.1 cm2; P < 0.001), fascicles were 0.6 cm shorter (0.5-0.7 cm; P < 0.001) and pennation angle was 2.5° higher (1.3-3.6°; P < 0.001) when compared to the uninjured limb. We found no differences between injured and uninjured tendon stiffness 1-year post-rupture (mean difference: 29.8 N/mm, -7.7-67.3 N/mm; P = 0.170). The injured tendon showed 1.8 mm (1.2-2.4 mm; P < 0.01) lower elongation during maximal voluntary isometric contractions. Patient-reported functional outcome was related to the tendon resting length (ß = 0.68, r(10) = 4.079, P = 0.002). Inter-limb differences in the medial gastrocnemius fascicle length were related to inter-limb differences in maximum contractions (ß = 1.17, r(14) = 2.808, P = 0.014). INTERPRETATION: Longer Achilles tendon resting length was associated with poorer self-evaluated functional outcome. Although the stiffness of non-surgically treated and uninjured tendons was similar 1-year post rupture, plantar flexion strength deficit was still present, possibly due to shorter medial gastrocnemius fascicle length.

The epidemiology of Achilles tendon re-rupture and associated risk factors: male gender, younger age and traditional immobilising rehabilitation are risk factors.

PURPOSE: The aim of this study was to describe the epidemiology of Achilles tendon re-rupture. Secondary aims were to identify factors predisposing to increased Achilles tendon re-rupture risk, at the time of primary Achilles tendon rupture. METHODS: A retrospective review of all patients with primary Achilles tendon rupture and Achilles tendon re-rupture was undertaken. Two separate databases were compiled: the first included all Achilles tendon re-ruptures presenting during the study period and described epidemiology, mechanisms and nature of the re-rupture; the second was a case-control study analysing differences between patients with primary Achilles tendon rupture during the study period, who did, or did not, go on to develop re-rupture, with minimum review period of 1.5 years. RESULTS: Seven hundred and eighty-three patients (567 males, 216 females) attended with primary Achilles tendon rupture and 48 patients (41 males, 7 females) with Achilles tendon re-rupture. Median time to re-rupture was 98.5 days (IQR 82-122.5), but 8/48 re-ruptures occurred late (range 3 to 50 years) after primary Achilles tendon rupture. Males were affected more commonly (OR = 7.40, 95% CI 0.91-60.15; p = 0.034). Mean Achilles tendon re-rupture incidence was 0.94/100,000/year for all ages and 1.16/100,000/year for adults (≥ 18 years). Age distribution was bimodal for both primary Achilles tendon rupture and re-rupture, peaking in the fifth decade, with secondary peaks in older age. Incidence of re-rupture was higher in less socioeconomically deprived sub-populations (OR = 2.01, 95%CI 1.01-3.97, p = 0.04). The majority of re-ruptures were low-energy injuries. Greater risk of re-rupture was noted for patients with primary rupture aged < 45 years [adjusted odds ratio (aOR) 1.96; p = 0.037] and those treated with traditional cast immobilisation (aOR 2.20; p = 0.050). CONCLUSION: The epidemiology of Achilles tendon re-rupture is described and known trends (e.g. male predilection) are confirmed, while other novel findings are described, including incidence of a small but significant number of late re-ruptures, occurring years after the primary injury and an increased incidence of re-rupture in less socioeconomically deprived patients. Younger age and traditional immobilising cast treatment of primary Achilles tendon rupture were independently associated with Achilles tendon re-rupture. LEVEL OF EVIDENCE: III.