Spontaneous tendon ruptures in patients on chronic dialysis

Patellar and quadriceps tendon rupture are associated with hip fracture in hemodialysis patients with severe hyperparathyroidism

Spontaneous rupture of the patellar (PTR) and quadriceps (QTR) tendon is infrequent. Systemic diseases such as diabetes mellitus, CKD, and secondary hyperparathyroidism (SHPT) are risk factors. The present cohort study aimed to evaluate risk factors associated with tendon rupture in hemodialysis (HD) patients with SHPT, as well as outcomes including surgical complications, re-ruptures, and fracture. Baseline clinical, laboratorial data, and radiographs were analyzed. Patients were followed up from March 2012 to March 2020. One-hundred thirty-one patients (≥18 yr of age, on HD ≥ 6 mo, with SHPT) were included. Incidence rates of PTR and QTR were 2.3 and 1.7/10000 HD patients/yr, respectively. The mean age of patients with tendon rupture was 44.0 ± 11.2 yr. These patients exhibited higher serum levels of phosphorus (6.3 ± 1.5 mg/dL vs 5.6 ± 1.1 mg/dL; P = .005), PTH (2025.7 ± 667.6 pg/mL vs 1728.4 ± 684.8 pg/mL; P = .035), and C-reactive-protein (35.4 ± 32.9 mg/dL vs 17 ± 24.5 mg/dL; P = .002) compared to the group without tendon rupture. The mean follow-up was 56.7 ± 27.1 mo. No patient required a new surgical approach or experienced re-rupture. Of all patients, 31% experienced hip fracture: 50% in the group with rupture (29.5 ± 17.4 mo after the tendon rupture) vs 26% without tendon rupture (P = .015). After adjustment, the hazard ratio for hip fracture was 2.87 (95% CI, 1.27-6.49; P = .012). Patients with SHPT and high levels of phosphorus, PTH, and inflammatory markers were at greater risk for tendon rupture. Surgical complication rates were low. However, results suggest that tendon rupture of knee extensor mechanism in HD patient with SHPT should be regarded as a "red flag" for future hip fracture.

Acidosis induces significant changes to the murine supraspinatus enthesis organic matrix

Rotator cuff pathology is a common musculoskeletal condition that disproportionately affects older adults, as well as patients with diabetes mellitus and chronic kidney disease. It is known that increased age and kidney dysfunction have been correlated to acidotic states, which may be related to the increased incidence of rotator cuff injury. In order to investigate the potential relationship between acidosis and rotator cuff composition and mechanics, this study utilizes a 14-day murine model of metabolic acidosis and examines the effects on the supraspinatus tendon-humeral head attachment complex. The elastic matrix in the enthesis exhibited significant changes beginning at day 3 of acidosis exposure. At day 3 and day 7 timepoints, there was a decrease in collagen content seen in both mineralized and unmineralized tissue as well as a decrease in mineral:matrix ratio. There is also evidence of both mineral dissolution and reprecipitation as buffering ions continually promote pH homeostasis. Mechanical properties of the tendon-to-bone attachment were studied; however, no significant changes were elicited in this 14-day model of acidosis. These findings suggest that acidosis can result in significant changes in enthesis composition over the course of 14 days; however, enthesis mechanics may be more structurally mediated rather than affected by compositional changes.

Clinical and Ultrasonographic Characteristics of the Achilles Tendon in Hemodialysis Patients

Background and Objectives: The early recognition of tendon alterations in chronic hemodialysis (HD) patients, an awareness of the factors that influence the condition, and active intervention have considerable clinical relevance. The aim of this study was to investigate the musculoskeletal ultrasound (MSUS) features of the Achilles tendon in chronic HD patients and determine the factors associated with tendon abnormalities. Materials and Methods: This study was conducted on 46 HD patients and 24 sex- and age-matched controls. All participants were evaluated clinically for any signs of Achilles tendon abnormalities. Then, the Achilles tendon was scanned bilaterally using MSUS. Results: Among the 92 Achilles tendons in the HD patients, there was tenderness and swelling of only two (2.2%). Regarding MSUS features, there were statistically significant higher thicknesses in the proximal end (p < 0.001), midpoint (p < 0.001), and distal end (p < 0.001) of the Achilles tendons in the HD patients when compared with the healthy controls. Tendinosis was found in 12 (13%) of the HD patients' Achilles tendons, which was statistically significant in comparison to the healthy controls (p = 0.008). There were statistically significant higher scores of structural abnormalities (p = 0.005), bone erosions (p = 0.017), and calcifications (p = 0.015) in the HD patients when compared to the healthy controls. According to the results of a univariate regression analysis, age and male gender were predictive for US abnormalities in HD patients (p = 0.002 and 0.025, respectively). Conclusions: The Achilles tendon in subjects on chronic HD showed frequent US abnormalities. These abnormalities in HD patients appear to be more related to age and gender and may be asymptomatic.

A retrospective case series of the treatment of spontaneous quadriceps tendon rupture in patients with uremia and secondary hyperparathyroidism

Background

Spontaneous quadriceps tendon rupture (QTR) is a rare complication of uremia. Secondary hyperparathyroidism (SHPT) is considered the leading cause of QTR in uremia patients. QTR in patients with uremia and SHPT are treated with active surgical repair along with the treatment of SHPT using medication or parathyroidectomy (PTX). The impact of PTX for SHPT on tendon healing remains unclear. The purpose of this study was to introduce surgical procedures for QTR and to determine the functional recovery of the repaired quadriceps tendon (QT) after PTX.

Methods

Between Jan 2014 and Dec 2018, eight uremia patients underwent PTX after a ruptured QT was repaired by figure-of-eight trans-osseous sutures with an overlapping tightening suture technique. Biochemical indices were measured before and one year after PTX to evaluate the control of SHPT. The changes in bone mineral density (BMD) were determined by comparing x-ray images at pre-PTX and during follow-up. The assessment of the functional recovery of the repaired QT was conducted at the last follow-up using multiple functional parameters.

Results

Eight patients (fourteen tendons) were retrospectively evaluated at an average follow-up of 3.46 ± 1.37 years after PTX. ALP and iPTH levels one year after PTX were significantly lower than at pre-PTX (P = 0.017, P < 0.001, respectively). Although there was no statistical differences compared to pre-PTX, serum phosphorus levels decreased and returned to normal one year after PTX (P = 0.101). BMD significantly increased at the last follow-up compared to pre-PTX. The average Lysholm score was 73.5 ± 11.07 and the average Tegner activity score was 2.63 ± 1.06. The active knee ROM after repair averaged an extension of 2.85 ± 3.78° to a flexion angle of 113.21 ± 10.12°. The quadriceps muscle strength was grade IV and the mean Insall-Salvati index was 0.93 ± 0.10 in all of the knees with tendon ruptures. All patients were able to walk without external help.

Conclusions

Figure-of-eight trans-osseous sutures with an overlapping tightening suture technique is an economical and effective treatment for spontaneous QTR in patients with uremia and SHPT. PTX may promote tendon-bone healing in patients with uremia and SHPT.

Spontaneous and simultaneous rupture of both Achilles tendons in a haemodialysis patient

This case involved a male patient in his 30s who sustained a spontaneous and simultaneous bilateral rupture of the Achilles tendons. His medical history was significant for end-stage renal failure for which he had been undergoing haemodialysis for 13 years, and parathyroidectomy 2 years before this presentation. The patient underwent an open repair of both Achilles tendons using gastrocnemius augmentation with a favourable final outcome. The radical control of secondary hyperparathyroidism in haemodialysis patients does not protect the patient from the occurrence of spontaneous tendon rupture in all cases.

Morphometric magnetic resonance imaging study of the quadriceps tendon in hemodialysis patients: comparison with non-dialyzed controls

Objective

To evaluate the knees of individuals with renal failure who are on hemodialysis, using magnetic resonance imaging (MRI), comparing them with those of a group of individuals with normal renal function.

Materials and Methods

This was a cross-sectional, observational, controlled study conducted between August 2018 and February 2020. The cases consisted of 15 patients who had been on hemodialysis for ≥ 5 years and did not have a quadriceps tendon rupture. The controls consisted of 15 individuals with normal renal function who were matched (1:1) to the cases for sex, age, and physical activity level. The subjects in both groups underwent MRI of the right knee only.

Results

The mean ages of the cases and controls were 50 ± 15 years and 49 ± 14 years, respectively. The median time on hemodialysis was 11 years (range, 10-14 years). Serum levels of parathyroid hormone, ferritin, alkaline phosphatase, phosphorus, and creatinine were higher among the cases than among the controls, whereas serum albumin and hemoglobin were lower (p < 0.05 for all). The MRI study showed a hyperintense signal in the quadriceps tendon in 11 of the cases and in three of the controls (p = 0.009). Knee joint effusion was observed in nine of the cases and in three of the controls (p < 0.05). The thickness, length, and width of the tendon did not differ between the groups. A hyperintense signal in the tendon was not associated with the time on hemodialysis; nor with the levels of intact parathyroid hormone, hemoglobin, or alkaline phosphatase.

Conclusion

Patients on chronic hemodialysis, even those without a tendon rupture, show a hyperintense signal in the quadriceps tendon on MRI.

Update on imaging in chronic kidney disease-mineral and bone disorder: promising role of functional imaging

Disorders of mineral metabolism and bone disease are common complications in chronic kidney disease (CKD) patients and are associated with increased morbidity and mortality. Bone biopsies, bone scintigraphy, biochemical markers, and plain films have been used to assess bone disorders and bone turnover. Of these, functional imaging is less invasive than bone/marrow sampling, more specific than serum markers and is therefore ideally placed to assess total skeletal metabolism. ¹⁸F-sodium fluoride (NaF) PET/CT is an excellent bone-seeking agent superior to conventional bone scan in CKD patients due to its high bone uptake, rapid single-pass extraction, and minimal binding to serum proteins. Due to these properties, ¹⁸F-NaF can better assess the skeletal metabolism on primary diagnosis and following treatment in CKD patients. With the increased accessibility of PET scanners, it is likely that PET scanning with bone-specific tracers such as ¹⁸F-NaF will be used more regularly for clinical assessment and quantitation of bone kinetics. This article describes the pattern of scintigraphic/functional appearances secondary to musculoskeletal alterations that might occur in patients with CKD.

Simultaneous Bilateral Distal Biceps Musculotendinous and Distal Avulsion Injuries: A Case Report

CASE

A patient presented with simultaneous left-sided distal biceps tendon rupture and a right-sided distal biceps complete musculotendinous junction tear after lifting a motorcycle. The left upper extremity was treated operatively with acute repair, and the right upper extremity was managed nonoperatively. At the final follow-up, the patient reported full strength and motion with Disabilities of the Arm, Shoulder and Hand (DASH) and QuickDASH scores of 14.2 and 20.5, respectively.

CONCLUSION

We report the first known case of simultaneous bilateral distal biceps injuries occurring at different anatomic locations. One side was operatively managed, whereas the other underwent conservative treatment. Both treatments resulted in a satisfactory patient outcome.

Bilateral Quadriceps Rupture in an Elite Weight Lifter: A Case Report and Review of Literature

Simultaneous bilateral quadriceps tendon ruptures (QTR) are rare injuries in sportspersons; weightlifting, involving sudden eccentric contraction of the bilateral quadriceps, has the potential to cause this injury. We present a case of an elite weightlifter with bilateral quadriceps tear occurring during the "jerk" part of clean and jerk phase of weightlifting; single stage bilateral end to end repair was done, followed by 3 weeks of cast immobilisation. He then underwent a supervised rehabilitation protocol, leading to graduated strengthening of the muscles. He went back to competitive sport after 2 years and participated in a national championship after 5 years. Detailed questioning revealed a history of anabolic steroid use in the early phase of his career; a literature review showed only seven cases of this injury pattern in weightlifting/bodybuilding sports, and five of these seven had a definitive history of anabolic steroid use. Bilateral QTR may be a pointer to predisposing factors like use of steroids, which should be diligently identified. Good outcomes are possible after early surgical repair and rehabilitation, with high rates of return to sports.

Virtual touch IQ elastography in evaluation of Achilles tendon in patients with chronic renal failure

PURPOSE

To evaluate the sonoelastographic changes in the Achilles tendon in patients with chronic renal failure (CRF) using virtual touch imaging quantification (VTIQ) elastography.

METHODS

Twenty-six patients undergoing three hemodialysis sessions per week and 26 subjects admitted to our institution between January 2016 and April 2016 were included in this prospective study. The characteristics and body mass index of the patients were noted. Ultrasonography was performed parallel to the long axis of the bilateral Achilles tendons during relaxation of the legs using the Siemens Acuson S3000™ ultrasound device (Siemens HealthCare, Erlangen, Germany). Tendon thickness was reviewed, and tissue stiffness was quantitatively assessed using VTIQ elastography. Independent samples t test and Mann-Whitney U test were used for statistical analyses.

RESULTS

The median values of shear wave velocities of the Achilles tendon in patients with CRF were 7.19 m/s (4.23-9.77 m/s) on the right and 6.98 m/s (4.00-9.82 m/s) on the left, while they were 5.11 m/s (4.09-8.82 m/s) on the right and 5.36 m/s (4.05-8.80 m/s) on the left in controls. The stiffness of the Achilles tendons in patients with CRF was found to be higher than that in controls (right: P < 0.001, left: P = 0.004). There was no statistically significant difference in tendon thickness between the CRF and control groups (P > 0.05).

CONCLUSION

The thickness and stiffness of tendon can be effectively evaluated with sonoelastography. The thickness of the Achilles tendon did not significantly differ between the patients with CRF and healthy subjects. However, the stiffness of the Achilles tendon measured with VTIQ elastography was demonstrated to be increased in the patients with CRF.

Incidence, Risk Factors, and Treatment of Achilles Tendon Rupture in Patients With End-Stage Renal Disease

BACKGROUND

Dialysis-dependent patients and kidney transplant recipients may be at increased risk for Achilles tendon rupture (ATR).

METHODS

We studied Medicare patients with end-stage renal disease (ESRD) from 1999 through 2013. Patients were categorized as waitlisted for a transplant, not waitlisted, or received a transplant. We performed multivariate negative binomial regression using demographic characteristics, comorbidities, and year of study entry to estimate adjusted incidence rate ratios (aIRRs), identify ATR risk factors, and determine treatment patterns and outcomes.

RESULTS

We identified 1091 ATRs (incidence, 3.80/10 000 person-years; 95% confidence interval [CI], 3.58-4.03). Compared with transplant recipients, nonwaitlisted patients had a lower incidence (aIRR, 0.44; 95% CI, 0.37-0.53), and waitlisted patients had a similar incidence (aIRR, 0.94; 95% CI, 0.78-1.12) of ATR. ATR incidence was higher among patients taking fluoroquinolones (aIRR, 1.65; 95% CI, 1.32-1.84) and corticosteroids (aIRR, 1.72; 95% CI, 1.44-2.05) compared with those who did not. Patients with ATR were younger, had higher mean body mass index, and had fewer comorbidities than patients without ATR. Seventeen percent of patients received operative treatment within 14 days of ATR diagnosis. The 30-day cumulative incidence of operative site infections was 6.5%.

CONCLUSION

The incidence of ATR was higher among transplant recipients and waitlisted patients compared with nonwaitlisted patients. Younger age, higher body mass index, fewer comorbidities, fluoroquinolone use, and corticosteroid use were risk factors for ATR. Patients were more likely to receive nonoperative than operative treatment for ATR. Those who underwent operative treatment had a low incidence of operative site infection.

LEVEL OF EVIDENCE

Prognostic level III, comparative study.

Simultaneous bilateral rupture of patellar tendons in diabetic hemodialysis patient: A case report

BACKGROUND

Bilateral rupture of the patellar tendon is a very rare injury, which takes place in relation to chronic systemic diseases. These injuries are known causes. Some of these causes are particular in patellar tendon rupture and another are in quadriceps tendon rupture.

CASE PRESENTATION

70-year-old diabetic man with simultaneous bilateral patellar tendon disruption of proximal insertion without trauma, receiving long-term hemodialysis.

CONCLUSIONS

In the present study, we report a case of patellar tendon rupture that has two differences with literature: first, renal failure is a known risk factor for quadriceps tendon rupture, and secondly, the prevalent age of patellar tendon rupture is less than 40 years. Clinical picture, diagnosis, pathogenesis and treatment are discussed. Finally, the literature is reviewed based on previous studies.

A case report of spontaneous rupture of the quadriceps tendon

Spontaneous quadriceps tendon rupture is a rare occurrence in patients with primary hyperparathyroidism (PHPT), which is less common in adolescents. We first reported a spontaneous unilateral rupture in a young patient with PHPT.

Geovariation in Fracture Risk among Patients Receiving Hemodialysis

BACKGROUND AND OBJECTIVES

Fractures are a major source of morbidity and mortality in patients receiving dialysis. We sought to determine whether rates of fractures and tendon ruptures vary geographically.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Data from the US Renal Data System were used to create four yearly cohorts, 2007-2010, including all eligible prevalent patients on hemodialysis in the United States on January 1 of each year. A secondary analysis comprising patients in a large dialysis organization conducted over the same period permitted inclusion of patient-level markers of mineral metabolism. Patients were grouped into 10 regions designated by the Centers for Medicare and Medicaid Services and divided by latitude into one of three bands: south, <35°; middle, 35° to <40°; and north, ≥40°. Poisson regression was used to calculate unadjusted and adjusted region-level rate ratios for events.

RESULTS

Overall, 327,615 patients on hemodialysis were included. Mean (SD) age was 61.8 (15.0) years old, 52.7% were white, and 55.0% were men. During 716,962 person-years of follow-up, 44,014 fractures and tendon ruptures occurred, the latter being only 0.3% of overall events. Event rates ranged from 5.36 to 7.83 per 100 person-years, a 1.5-fold rate difference across regions. Unadjusted region-level rate ratios varied from 0.83 (95% confidence interval, 0.81 to 0.85) to 1.20 (95% confidence interval, 1.18 to 1.23), a 1.45-fold rate difference. After adjustment for a wide range of case mix variables, a 1.33-fold variation in rates remained. Rates were higher in north and middle bands than the south (north rate ratio, 1.18; 95% confidence interval, 1.13 to 1.23; middle rate ratio, 1.13; 95% confidence interval, 1.10 to 1.17). Latitude explained 11% of variation, independent of region. A complementary analysis of 87,013 patients from a large dialysis organization further adjusted for circulating mineral metabolic parameters and protein energy wasting yielded similar results.

CONCLUSIONS

Rates of fractures vary geographically in the United States dialysis population, even after adjustment for known patient characteristics. Latitude seems to contribute to this phenomenon, but additional analyses exploring whether other factors might influence variation are warranted.

Simultaneous Bilateral Rupture of the Triceps Tendon in a Renal Transplant Patient

The unilateral rupture of the triceps brachii tendon is a rare lesion representing 1% of all tendon injuries. The most common causes are the result of a contraction against resistance (especially weightlifters) and direct trauma. It has also been associated with systemic diseases such as diabetes mellitus, chronic renal failure, secondary hyperparathyroidism, and use of systemic corticosteroids. Simultaneous bilateral rupture of the triceps tendons is less frequent and has been described in association with chronic metabolic disorders, especially in those patients on hemodialysis. This paper presents a case of bilateral triceps tendon rupture of a 36-year-old woman with renal transplantation secondary to chronic renal failure. Early surgical repair was performed using a bone tunnel technique with a nonabsorbable suture. Clinically active extension with 135 degrees of range of motion was achieved.

Real-time sonoelastography of the quadriceps tendon in patients undergoing chronic hemodialysis

OBJECTIVES

This study aimed to compare sonoelastographic findings for the quadriceps tendon in patients with chronic renal failure who were in a dialysis program to findings in a control group.

METHODS

Fifty-three randomly allocated patients (mean age, 54.3 years; range, 27-86 years) with chronic renal failure who were in a dialysis program 3 days a week between January and May 2012 were included. The measurements were performed in both knees of 53 patients undergoing dialysis and 25 individuals in the control group. The tendons were classified as follows: type 1, very stiff tissue (blue); type 2, stiff tissue (blue-green); and type 3, intermediate tissue (green-yellow) according to color mapping.

RESULTS

The mean quadriceps tendon thicknesses in the patient group were 4.9 mm (range, 1.9-6.5 mm) for the right knee and 4.9 mm (1.4-6.5 mm) for the left knee; the values in the control group were 5.4 mm (3.6-7.0 mm) for the right knee and 5.4 mm (3.4-7.0 mm) for the left knee. The mean elasticity scores in the patient group were 3.14 (1.03-5.23) for the right knee and 3.33 (1.29-5.00) for the left knee; in the control group, the values were 3.79 (1.73-5.23) and 3.69 (1.23-5.53) for the right and left knees, respectively (right knee, P = .025; left knee, P = .018; Mann-Whitney U test). The quadriceps tendons were significantly thinner in the patient group (right knee, P = .054; left knee, P = .015; Mann-Whitney U test).

CONCLUSIONS

Quadriceps tendons in patients with chronic renal failure are thinner and have lower elasticity scores compared to controls.

Imaging Findings and Evaluation of Metabolic Bone Disease

Bone is a dynamic organ of the endoskeleton, playing an important role in structural integrity, mineral reservoirs, blood production, coagulation, and immunity. Metabolic bone disease encompasses a broad spectrum of inherited and acquired disorders that disrupt the normal homeostasis of bone formation and resorption. For patients affected by these processes, radiologic imaging plays a central role in diagnosis, monitoring treatment, and risk stratification. Radiologists should be familiar with the diseases, intimately aware of the imaging findings, and possessive of multimodality expertise to wisely guide the best practice of medicine. The purpose of this paper is to review the imaging features and characteristics of the most common types of metabolic bone disease with highlights of clinically relevant information so that readers can better generate appropriate differential diagnoses and recommendations. For this review, a thorough literature search for the most up-to-date information was performed on several key types of metabolic bone disease: osteoporosis, osteomalacia, rickets, scurvy, renal osteodystrophy, hyperparathyroidism, Paget’s disease, osteogenesis imperfecta, acromegaly, and osteopetrosis. Although they all affect the bone, these diseases have both shared characteristic features that can be discerned through imaging.

Quadriceps tendon rupture in maintenance haemodialysis patients: results of surgical treatment and analysis of risk factors

BACKGROUND

Reports of spontaneous quadriceps ruptures in end-stage renal disease (ESRD) patients are scarce, and the assessment of risk factors for tendon rupture is poorly addressed in the majority of the studies. The purpose of the present study is to report a series of patients on haemodialysis with spontaneous quadriceps tendon ruptures operated at our institution. The results of the surgical treatment are described and the potential risk factors associated with the rupture are analyzed.

METHODS

Our study consisted of retrospective analysis of patient's charts. Clinical and laboratory findings of the operated group were compared to the ones of a control group of haemodialysis patients matched by age, gender, and time on haemodialysis, but without tendon rupture.

RESULTS

Between 1998 and 2010, six ESRD patients with 11 spontaneous ruptures of the quadriceps tendon were treated at our institution. On postoperative evaluation all patients were able to walk without crutches after six months of follow-up, and there were no new ruptures. Positive serology for Hepatitis C was present in two cases (33%) but in none of the controls (p = 0.034). Mean serum levels of intact parathormone (iPTH) and alkaline phosphatase were both higher in cases (p = 0.013 and p = 0.034, respectively). In contrast, mean serum levels of albumin, ferritin and haemoglobin were all lower in cases (p = 0.008, p = 0.043 and p = 0.016, respectively).

CONCLUSION

Reconstructive surgery is a good way to restore knee function in ESRD patients with quadriceps tendon ruptures. Our cases exhibited higher levels of iPTH and alkaline phosphatase than control patients, reinforcing the role of secondary hyperparathyroidism in tendon weakening. They also had a higher frequency of hepatitis C and lower levels of albumin and haemoglobin compared to controls, possibly implicating chronic inflammation as a potential risk factor for tendon rupture.

[Bilateral rupture of patellar tendons in young patients with no notion of systemic disease or corticosteroid therapy: report of a case and review of the literature]

Les lésions du tendon rotulien sont moins communes que celles du tendon quadricipital. Les lésions bilatérales sont encore plus rares et sont souvent associées à une notion de tendinopathie, d'injection de corticoïdes ou de maladies systémiques tels que le lupus érythémateux, l'ostéomalacie ou l'insuffisance rénale chronique. Nous rapportons le cas d'un patient de 26 ans victime d'une rupture bilatérale du tendon rotulien suite à une réception de saut. Le patient n'avait pas d'antécédents de tendinopathie ni de maladies systémiques. Le diagnostic a été suspecté devant une position anormalement haute des deux rotules avec une impossibilité d'extension active des deux jambes. L’échographie a confirmé le diagnostic. Le patient a été traité par la technique de laçage selon Judet protégée par un cadrage. La rupture bilatérale du tendon rotulien est rare. La plupart des patients rapportent une notion de maladie systémique ou un antécédents de chirurgie du genou. Nous rapportons le cas d'une lésion rare dans la littérature, une rupture bilatérale des tendons rotuliens sans notions de maladies auto-immunes ni de traitement avec des corticostéroïdes. Les lésions bilatérales présentent certaines particularités diagnostiques et thérapeutiques. En effet l'objectivation d'une rotule haute peut être rendu difficile par un aspect controlatéral semblable. Concernant le volet thérapeutique, deux difficultés sont à noter la première réside dans l'absence de référence comparative pour la hauteur patellaire. La deuxième difficulté est l'obligation de différer l'appui à 45 jours. Ce qui est contraignant pour le patient. La technique de laçage décrite par judet couplée à un cadrage provisoire protégeant la suture nous a donné des résultats satisfaisants.

Bilateral Achilles Tendon Ruptures Associated With Ciprofloxacin Use in the Setting of Minimal Change Disease: Case Report and Review of the Literature

Fluoroquinolones are widely used antibiotics; however, numerous side effects have been reported in published studies, including a spectrum of tendinopathies, affecting numerous anatomic sites. Several risk factors have been identified, including advanced age (>60 years), corticosteroid use, renal failure or dialysis, female sex, and nonobesity. We present the case of an elderly male with minimal change disease treated with glucocorticoids and acute kidney injury, who sustained spontaneous nontraumatic bilateral Achilles tendon tears 4 days after initiating ciprofloxacin.

Knuckle cracking: secondary hyperparathyroidism and what your mother did not tell you

INTRODUCTION

Secondary hyperparathyroidism in end-stage renal disease patients has protean musculoskeletal manifestations. Some of our dialysis patients spontaneously vocalized that they had lost the ability to crack their knuckles and then experienced gratifying restoration after surgical parathyroidectomy. We propose that the physiology and mechanical basis of knuckle cracking would be affected by parathyroid-related mineral and bone disorders.

METHODS AND RESULTS

We surveyed all of our chronic dialysis outpatients who had undergone surgical parathyroidectomy. Thirteen (∼12% of the population) individuals were identified: eight males, age 37.7 ± 12.5 years old, dialysis duration of 10.2 ± 7.0 years and peak preoperative intact parathyroid hormone (PTH) levels of 2344 ± 900 pg/mL. Seven patients had no recollection of knuckle cracking issues, with surgery as remote as decades. Six individuals were able to provide adequate histories: four had postoperative restoration of knuckle cracking and expressed great satisfaction from the emotional relief from what appeared to be habitual knuckle cracking. Two of these patients reported rapid return of cracking, occurring in less than ∼2 weeks.

CONCLUSIONS

This is the first report of loss of knuckle cracking due to hyperparathyroidism and its cure in 67% of patients, following surgical parathyroidectomy. We propose that parathyroid (e.g. calcific) changes in articular structures (tendons, ligaments) cause reduced elasticity, limited joint surface separation upon flexion, attenuation of cavitation and thus, loss of the audible crack upon vacuum collapse. The psychological 'release' from habitual knuckle cracking may be a motivator from some patients to adhere to complex parathyroid regimens or to pursue surgical intervention.

Simultaneous bilateral rupture of the patellar ligament in chronic renal patient. A case report

The authors report a case of simultaneous bilateral rupture of the patellar ligament resulting of low-energy trauma in a patient with chronic renal failure.

Various musculoskeletal manifestations of chronic renal insufficiency

Musculoskeletal manifestations in chronic renal insufficiency are caused by complex bone metabolism alterations, now described under the umbrella term of chronic kidney disease mineral- and bone-related disorder (CKD-MBD), as well as iatrogenic processes related to renal replacement treatment. Radiological imaging remains the mainstay of disease assessment. This review aims to illustrate the radiological features of CKD-MBD, such as secondary hyperparathyroidism, osteomalacia, adynamic bone disease, soft-tissue calcifications; as well as features associated with renal replacement therapy, such as aluminium toxicity, secondary amyloidosis, destructive spondyloarthropathy, haemodialysis-related erosive arthropathy, tendon rupture, osteonecrosis, and infection.

Creatinine and nonprotein nitrogen plasma levels: possible etiopathogenetic factors in rotator cuff tears

OBJECTIVE

To determine the plasma levels of nonprotein nitrogen (NPN) and creatinine in healthy patients with rotator cuff tears.

METHODS

The study included 400 subjects. The study group included 200 patients (93 men and 107 women; mean age, 56.8 years; range, 23-81 years) who underwent arthroscopic repair of a rotator cuff tear from 2004 to 2007. The control group included 200 patients (93 men and 107 women; mean age, 53.9 years; range, 20-81 years) who underwent arthroscopy for management of a meniscal tear, with or without articular cartilage damage, in the same period. The 2 groups were frequency-matched by age and sex. Measurement of plasma levels of NPN and creatinine were performed in all patients.

RESULTS

Patients with rotator cuff tears showed higher plasma NPN levels within the normal range (P = 0.035) than patients with knee disorders (control group). Creatinine levels were comparable (P = 0.66) in both groups.

CONCLUSION

There appears to be an association between plasma NPN levels and rotator cuff tears. On the basis of our findings, plasma NPN could be involved in the pathogenesis of rotator cuff tears, although we advocate further research to draw more definitive conclusions.

Sonographic subclinical entheseal involvement in dialysis patients

Long-term dialysis treatment can be associated with several musculoskeletal complications. Entheseal involvement in dialysis patients remains rarely studied as its prevalence is underestimated due to its often asymptomatic presentation. The aims of the study were to determine the prevalence of subclinical enthesopathy in haemodialysis and peritoneal dialysis patients at the lower limb level, to investigate the inter-observer reliability of ultrasound assessment and to analyse the influence of biometric and biochemical parameters. Ultrasound examination was conducted at the entheses of the lower limbs level in 33 asymptomatic dialysis patients and 33 healthy adopting the Glasgow Ultrasound Enthesitis Scoring System (GUESS). The inter-observer reliability was calculated in 15 dialysis patients. Ultrasound found at least one sign of enthesopathy in 165 out of 330 (50%) entheses of dialysis patients. In healthy subjects, signs of enthesopathy were present in 54 out of 330 (16.3%) entheses (p < 0.0001). No power Doppler signal was detected in healthy controls, in contrast to four of 330 entheses of dialysis patients. No US signs of soft tissue amyloid deposits were found. The GUESS score was significantly higher in dialysis patients than in controls (p < 0.0001). There was no difference in terms of enthesopathy between haemodialysis and peritoneal dialysis. Dialysis duration resulted to be the most important predictor for enthesopathy (p = 0.0004), followed by patient age (p = 0.02) and body mass index (p = 0.035). Parathormone, calcium, phosphorus, C-reactive protein, cholesterol and triglycerides apparently did not play a relevant role in favour of enthesopathy. The inter-observer reliability showed an excellent agreement between sonographers with different degree of experience. Our results demonstrated a higher prevalence of subclinical enthesopathy in both haemodialysis and peritoneal dialysis patients than in healthy subjects. Follow-up will provide further information with respect to the predictive value of US findings for the development of symptomatic dialysis-related arthropathy.

Bilateral and simultaneous triceps avulsions in a patient with chronic renal failure receiving long-term peritoneal dialysis

Simultaneous bilateral triceps tendon avulsions are extremely rare; only 4 cases have been reported in the international literature. This article describes a case of a 32-year-old woman with bilateral and simultaneous avulsions of the triceps tendons. She suffers from chronic renal failure and undergoes peritoneal dialysis every day. The patient presented with ecchymosis and swelling at the posterior aspect of both elbows. While climbing stairs a few hours earlier, she had fallen back on both outstretched arms, experienced moderate pain, and heard a sudden popping sound in her right elbow, followed by similar pain in the left elbow. On examination, she revealed intact extensor mechanism. Radiographs revealed a small osseous flake just proximal to the olecranon in both arms and the absence of associated fractures. During surgery, both triceps tendons appeared normal, other than being avulsed at their tendo-osseous junction. The patient obtained a successful result and full range of motion bilaterally within 3 months postoperatively. A high index of suspicion is needed and careful attention should be paid to elbow pain after minor trauma so that triceps injuries, especially in chronic kidney disease cases, are not missed.

Bilateral ruptures of the distal biceps brachii tendon

BACKGROUND

The purpose of this study was to identify characteristics associated with bilateral ruptures of the distal biceps tendons.

METHODS

We present a retrospective case series of 25 patients who sustained non-simultaneous bilateral distal biceps brachii tendon ruptures that were repaired surgically, with follow-up available on 10 patients. The average age of the patients was 50 years (range 28-76). All patients were male. The mean time from the first tendon rupture to the contralateral tendon rupture was 2.7 years (range 0.5 - 6.3). Follow-up averaged 45 months (range 24-85).

RESULTS

Patients with bilateral ruptures tended to be middle-aged men, who commonly participated in weight lifting, manual labor, or sports, and who had higher rates of nicotine (50%) and anabolic steroid use (20%) than the general population. After surgical repair of 9 of 10 patients, patients with bilateral distal biceps tendon ruptures had good to excellent outcomes. With the numbers available, outcomes were not statistically associated with manual labor, past medical history, prescription medications, prior tendon injury, body mass index, current activity in sports, use of nutritional supplements, or anabolic steroid use, although worker's compensation claims approached statistical significance (p = 0.059).

CONCLUSIONS

Patients who sustained bilateral distal biceps tendon ruptures tended to be middle-aged men with higher rates of nicotine and anabolic steroid use than the general population.

Spontaneous and simultaneous rupture of both Achilles tendons and pathological fracture of the femur neck in a patient receiving long-term hemodialysis

Spontaneous rupture of the Achilles tendons in hemodialysis patients is a rare complication. The majority of these patients have additional predisposing factors, such as previous use of fluoroquinolone antibiotics or corticosteroids. Spontaneous rupture of bilateral Achilles tendons without any of those predisposing factors is exceptional. In this paper, we report a 43-year-old woman who had been undergoing regular hemodialysis for 16 years. She developed bilateral spontaneous and simultaneous rupture of the Achilles tendons. She also developed pathological fracture of right femur neck 3 years later. Based on previous cases of tendon ruptures in uremic patients and the lack of history for the use of corticosteroids or fluoroquinolones, we believe that secondary hyperparathyroidism is the predisposing factor in this patient.

Relationship between vitamin D and muscle size and strength in patients on hemodialysis

OBJECTIVE

Vitamin D has various actions in skeletal muscle. The purpose of this study was to compare lower-limb muscle size and strength in hemodialysis (HD) patients being treated with 1,25-dihydroxyvitamin D (calcitriol) or a 1,25-dihydroxyvitamin D analogue (paricalcitol) with lower-limb muscle size and strength in HD patients who were receiving none.

DESIGN

This was a retrospective, cross-sectional study.

SETTING

This study was performed in outpatient HD centers.

PATIENTS

Hemodialysis patients receiving calcitriol or paricalcitol (active vitamin D) for control of secondary hyperparathyroidism (VitD, n = 49) were compared with HD patients who were not (n = 30).

MAIN OUTCOME MEASURES

The main outcome measures included the cross-sectional areas (CSAs) of the thigh and tibialis anterior muscles by magnetic resonance imaging, and three measures of strength: the three-repetition maximum (3RM) for knee extension (isotonic), the peak torque of knee extensors (isokinetic), and maximal voluntary contraction of the ankle dorsiflexor muscles (isometric).

RESULTS

There were no differences in age, weight, dialysis vintage, or intact parathyroid hormone levels between groups, although serum albumin was higher in the VitD group (P < .05). Patients in the VitD group had a larger thigh-muscle CSA (P < .05) and were stronger across all strength measures (P < .05) after controlling for age and gender (by analysis of covariance). When all analyses were subsequently adjusted for serum albumin concentration, only the difference in 3RM knee-extension strength lost significance. There were no significant differences in any measurements between patients who received calcitriol or paricalcitol.

CONCLUSION

Treatment with active vitamin D was associated with greater muscle size and strength in this cohort of HD patients.

Sonographic evaluation of entheseal sites of the lower extremity in patients undergoing hemodialysis

PURPOSE

To evaluate the entheseal sites of the lower extremities in patients on hemodialysis using the Glasgow Ultrasound Enthesitis Scoring System (GUESS) and to correlate the findings with the duration of hemodialysis and patient scores.

METHODS

Forty-nine patients who were on hemodialysis for at least 2 years were grouped according to duration of hemodialysis. Total GUESS scores; total enthesophyte, erosion, and bursitis scores; and tendon thicknesses were calculated, compared between groups, and correlated with duration of dialysis.

RESULTS

There was a statistically significant correlation between duration of hemodialysis and total GUESS score (p < 0.001, r = 0.81) and also between the total enthesophyte and erosion scores (p < 0.001). If severe enthesitis was defined as a total GUESS score of more than 18, receiver operating characteristic (ROC) curve analysis revealed that a cutoff point of 10 years for the duration of hemodialysis would predict severe enthesal damage with 83% sensitivity and 93% specificity (area under the ROC curve, 0.92; 95% confidence interval, 0.83-1.00).

CONCLUSION

Hemodialysis results in entheseal site changes that worsen with extended duration of hemodialysis, especially after 10 years.

Exercise in the end-stage renal disease population

Many of the known benefits of exercise in the general population are of particular relevance to the ESRD population. In addition, the poor physical functioning that is experienced by patients who are on dialysis is potentially addressable through exercise interventions. The study of exercise in the ESRD population dates back almost 30 yr, and numerous interventions, including aerobic training, resistance exercise training, and combined training programs, have reported beneficial effects. Recently, interventions during hemodialysis sessions have become more popular and have been shown to be safe. The risks of exercise in this population have not been rigorously studied, but there have been no reports of serious injury as a result of participation in an exercise training program. It is time that we incorporate exercise into the routine care of patients who are on dialysis, but identification of an optimal training regimen or regimens, according to patient characteristics or needs, is still needed to facilitate implementation of exercise programs.

Spontaneous rupture of the patellar and contralateral quadriceps tendons associated with secondary hyperparathyroidism in a patient receiving long-term dialysis

Although spontaneous rupture of the extensor tendon of the knee is more likely to occur in uremic patients with secondary hyperparathyroidism, simultaneous ruptures of bilateral knee extensor tendons is a rarely reported condition. We describe a 30-year-old man with uremia who underwent subtotal parathyroidectomy because of secondary hyperparathyroidism with very high serum parathyroid hormone (PTH) level (1940.4 pg/mL). Two weeks later, he complained of a sharp pain in both knees without trauma when he walked downstairs with his left knee forward and right knee behind. Spontaneous simultaneous ruptures of the right patellar tendon and the left quadriceps tendon were diagnosed and surgically repaired. The mechanism of spontaneous tendon rupture in uremic patients with secondary hyperparathyroidism seems to be related to high PTH level which results in osteolytic bone resorption at the tendon insertion site. Early surgical repair, control of secondary hyperparathyroidism, early use of vitamin D analogs, and total parathyroidectomy with or without autotransplantation of part of the parathyroid gland, can treat and prevent tendon rupture or re-rupture with satisfactory results.

Effect of diabetes mellitus on muscle size and strength in patients receiving dialysis therapy

BACKGROUND

Diabetes mellitus (DM) is a potential contributor to the muscle abnormalities and poor physical functioning of the dialysis population.

METHODS

Thirty-three dialysis patients without DM (non-DM group) were compared with 25 dialysis patients with DM (DM group). Measures were made of cross-sectional area and composition of the leg muscles by using proton T1-weighted magnetic resonance imaging; body composition by means of dual-energy X-ray absorptiometry; leg muscle strength by means of isokinetic knee extension; isometric dorsiflexor maximum voluntary contraction by means of force plate; physical activity by means of 3-dimensional accelerometry; and functional capacity by using various functional tests.

RESULTS

The DM group was older, weaker, more atrophic, and had a greater amount of intramuscular fat compared with the non-DM group. However, when the overall analysis was adjusted for age and sex, there were no differences between the 2 groups with respect to muscle cross-sectional area, leg strength, or physical activity. To further account for sex and age differences, a paired analysis was performed after matching patients by age (within 5 years) and sex (N = 16/group). In the matched analysis, only intramuscular fat and leg adipose tissue were different between the 2 groups.

CONCLUSION

DM is associated with more fat within muscles of dialysis patients, but is unrelated to muscle size or strength. Demographic differences between the DM and non-DM groups on dialysis therapy likely are responsible for the general perception that patients with DM are more debilitated.

Complications associated with the use of corticosteroids in the treatment of athletic injuries

BACKGROUND

The potent anti-inflammatory pharmacologic effects of the corticosteroids (cortisone and synthetic derivatives) has led to their extensive usage in the management of rheumatologic diseases and athletic musculoskeletal injuries. The efficacy and risks of locally injected or systemically administered corticosteroids in the treatment of athletic injuries are unclear.

OBJECTIVE

To review critically the medical literature and determine complications and risks associated with corticosteroid treatment of athletic injuries.

DATA SOURCES

A search of 3 databases-MEDLINE, CINAHL, and Cochrane Clinical Trial Register-was performed using the OVID interface for all years between 1966 and 2003. The search first combined all references under the medical subject headings adrenal cortex hormones, glucocorticoids, and glucocorticoids, synthetic. A second search combined all references under the medical subject headings athletic injuries, sprains and strains, tendon injuries, shoulder injuries, rotator cuff disease, tennis elbow, and lateral epicondylitis. The references identified by these 2 searches were intersected and limited to human only to produce 130 articles. Relevant review articles were scanned, references reviewed, and additional articles retrieved for consideration of inclusion.

STUDY SELECTION

For inclusion in this critical review, articles must meet the following criteria: (1) subjects were human, (2) subjects had athletic-related injuries, and (3) subjects received corticosteroid treatment. Ultimately, 43 studies met inclusion criteria.

DATA EXTRACTION AND SYNTHESIS

Selected articles were then categorized as to whether the primary focus was usage/efficacy of corticosteroid injection therapy, occurrence of complications of corticosteroid injection therapy, or usage or complications of systemic corticosteroid therapy.

MAIN RESULTS

Twenty-five selected studies primarily examined the usage/efficacy of corticosteroid injections in the treatment of various athletic injuries. Of the 983 total subjects who received corticosteroid injections among these studies, only minor complications of treatment were reported. Eighteen selected studies primarily described complications of corticosteroid injections in the treatment of athletic injuries. Of these, tendon and fascial ruptures were the predominant complications reported. The search identified no articles that addressed the usage of or complications of systemic corticosteroids in the treatment of athletic injuries, although tibial stress fracture and multifocal osteonecrosis occurred in individuals being treated for nonathletic injury conditions.

CONCLUSIONS

This critical review reveals that the existing medical literature does not provide precise estimates for complication rates following the therapeutic use of injected or systemic corticosteroids in the treatment of athletic injuries. Tendon and fascial ruptures are often reported complications of injected corticosteroids, whereas tibial stress fractures and multifocal osteonecrosis were described with systemic corticosteroids.

Fluoroquinolones and tendon disorders

Fluoroquinolones are the most potent oral antibiotics in clinical use today. Increasingly, these drugs are being prescribed for relatively benign infections and for new categories of patients, including paediatric patients. As their use becomes more frequent, so will the adverse events. This review focuses on a rare but debilitating adverse reaction, the fluoroquinolone-associated tendinopathy. Despite many published case reports and approximately 3500 cases reported to the World Health Organization Collaborating Centre for Drug Monitoring, little is known about the mechanisms behind this fluoroquinolone-specific toxicity. Data on chemical properties, mode of action, pharmacokinetic features, clinical presentation and risk factors in relation to tendon toxicity are discussed and the literature reviewed. As long as the musculoskeletal toxicity cannot be predicted by in vitro or in vivo models and this class of antibiotics is one of the most commonly linked to selection of resistant bacteria, a more prudent use of fluoroquinolones is warranted.

Exercise and Chronic Kidney Disease

Patients with chronic kidney disease (CKD) are inactive and have reduced physical functioning and performance. Aerobic exercise interventions have been shown to increase maximal oxygen consumption in selected patients. In addition, preliminary evidence, although mixed, suggests that aerobic exercise training can improve blood pressure control, lipid profiles and mental health in this population. A few larger studies are now available showing that aerobic training can also improve physical functioning and performance. The impact on survival or hospitalisation has not been determined. Resistance exercise training, although less studied, appears to increase muscle strength and size and may also improve functioning. There have been several reports of successful combined exercise interventions, but the designs have not allowed evaluation of the relative benefits of aerobic and resistance training on physical functioning. Despite the evidence that exercise is safe and beneficial in patients with CKD, dialysis patients remain inactive, and exercise assessment, counselling and training is not widely offered to patients with CKD. Studies of the barriers to patient participation in exercise and to provider assessment and recommendations are needed so that more widely generalisable interventions can be developed. However, in the interim, patients should be encouraged to participate in moderate physical activity to meet the US Surgeon General's recommendations. Patients who are weak can benefit from strength-training interventions. Resistance and aerobic exercise programmes should be initiated at relatively low intensity in patients with CKD and progressed as slowly as tolerated in order to avoid injury and discontinuation of exercise. For patients on haemodialysis, incorporation of exercise into the dialysis session may increase patient participation and tolerance of exercise.

Case Report. Simultaneous multiple tendon ruptures complicating a seizure in a haemodialysis patient

Non-traumatic rupture of large tendons is identified as a contributor to morbidity in patients who receive haemodialysis. The injury is likely to become more common as the duration of survival on dialysis extends. A number of predisposing factors leading to tendon injury have been identified in the literature, including secondary hyperparathyroidism, beta(2)-microglobulin associated amyloidosis, corticosteroid treatment and fluoroquinolone antibiotic use. This is a case report of a 31-year-old male who presented with simultaneous large tendon ruptures following epileptiform seizures. These occurred after 10 years of treatment for end-stage renal failure, including haemodialysis, with progressive secondary hyperparathyroidism. A review of the literature confirms progressive hyperparathyroidism as an important risk factor for large tendon rupture in patients on haemodialysis.

Above-knee amputation after recurrent dislocations of total knee arthroplasty

Amputation after total knee arthroplasty (TKA) is an extremely rare but disastrous complication. Most of the reported cases resulted from refractory deep joint sepsis or perioperative vascular complications. We present a case of above-knee amputation resulting from vascular complications after recurrent dislocations of a TKA in a patient with underlying end-stage renal disease. The possible association between certain metabolic diseases and instability of TKA is discussed. In contrast to the high incidence of vascular complications after traumatic knee dislocation, popliteal artery injury after TKA dislocation is seldom encountered. The importance of careful evaluation and serial physical examinations to exclude the possibility cannot be overemphasized, however. When compromise of the circulation was recognized, emergent exploration of the popliteal fossa for repair of the vascular injury presented the best chance to save the limb.

Spontaneous bilateral rupture of the Achilles tendon in a patient with chronic obstructive pulmonary disease

A 69-year-old man with chronic obstructive pulmonary disease (COPD) presented with an exacerbation of cough and breathlessness, as well as a 5 day history of sudden-onset bilateral calf tenderness. He had been commenced on inhaled steroids 41/2 years earlier and then received maintenance oral prednisone. Upon examination, there was a haematoma inferior to the medial malleolus with no Achilles tenderness on the left side. On the right side, there was focal tenderness over the mid-portion of the Achilles tendon with pain accentuated upon dorsi flexion. A venous duplex study confirmed superficial venous thrombosis involving the left gastrocnemius vein extending proximally to the popliteal vein junction. The major axial deep veins of the left lower leg were patent. Findings on the right side were normal. A subsequent diagnostic ultrasound demonstrated unequivocal bilateral Achilles tendon ruptures. The patient subsequently underwent corrective surgery. There have been several reports of bilateral Achilles tendon rupture associated with long-term corticosteroid use. It is likely that this entity is underdiagnosed because of a lack of awareness of this association by physicians. Recognition and surgical intervention are likely to reduce morbidity and improve outcome.

Biochemistry and biomechanics of healing tendon: Part I. Effects of rigid plaster casts and functional casts

PURPOSE

Traditional treatment of surgically repaired Achilles tendons includes complete immobilization of the joint in rigid casts for 6 to 8 wk. We tested the use of functional polyurethane casts as an alternative to rigid plaster casts after experimental tenotomy and repair of the rabbit Achilles tendon.

METHODS

After repair the limbs of 15 experimental rabbits were immobilized in a functional polyurethane cast for 15 d, while those of 14 controls were immobilized in traditional rigid plaster casts for the same period.

RESULTS

Functional casting resulted in a 60% increase in total collagen in the neotendon compared with that in rigid casting (P < 0.05). Mature collagen cross-links declined 8% in the tendons with functional casts. The biomechanical parameters of the tendons changed with functional casting, showing a 20% increase in maximum load and 21% increase in maximum stress.

CONCLUSIONS

These changes were noted without any cases of tendon re-rupture in either type of cast. Thus, functional casting following surgery of Achilles tendons appears to improve healing without significant risks of re-rupture.