Achilles tendinopathy: some aspects of basic science and clinical management

Achilles tendinopathy is prevalent and potentially incapacitating in athletes involved in running sports. It is a degenerative, not an inflammatory, condition. Most patients respond to conservative measures if the condition is recognised early. Surgery usually involves removal of adhesions and degenerated areas and decompression of the tendon by tenotomy or measures that influence the local circulation.

Dynamic contrast-enhanced mr imaging and histopathology in chronic achilles tendinosis. A longitudinal MR study of 15 patients

PURPOSE

To evaluate the value of dynamic contrast-enhanced MR imaging (DEMRI) and its correlation to symptoms and histopathology in chronic Achilles tendinosis.

MATERIAL AND METHODS

Fifteen patients with severe symptoms underwent DEMRI preoperatively and 2 years postoperatively. US-guided core biopsies of tendinosis tissue were obtained preoperatively and the specimens were analyzed using a semiquantitative protocol. DEMRI was evaluated by calculating the area under curve (AUC) of signal alteration and the static MR by a semiquantitative grading scale. A questionnaire and clinical examination evaluated the clinical outcome.

RESULTS

Early contrast enhancement (first 72 s) was seen in DEMRI at tendon lesions of the symptomatic Achilles tendons with a significant difference to asymptomatic contralateral tendon that revealed no or mild enhancement. Increased severity of tendon pathology (including fiber structure abnormality, increased vascularity, rounding of nuclei and increased amount of glycosaminoglycans) was correlated to both dynamic and static signal enhancement. Two years following surgical treatment, the signal alterations showed regression of early contrast enhancement (AUC decreased from 9 preoperatively to 2 postoperatively). The clinical outcome was as follows: 8 patients excellent, 4 good, 2 fair and 1 poor.

CONCLUSION

Patients with chronic painful achillodynia showed an early contrast-agent enhancement corresponding to the tendon lesion. Increased enhancement correlated to increased severity of tendon histopathology and patient symptoms. Two years after surgical treatment the contrast-agent enhancement decreased.

Mechanism of accumulation of cholesterol and cholestanol in tendons and the role of sterol 27-hydroxylase (CYP27A1)

OBJECTIVE

Tendon xanthomas are deposits of lipids and connective tissue commonly found in hypercholesterolemic patients. Macrophages are likely to be responsible for the lipid accumulation. Normolipidemic patients with the rare disease cerebrotendinous xanthomatosis, lacking the enzyme sterol 27-hydroxylase (CYP27A1), develop prominent xanthomas in tendons and brain containing both cholestanol and cholesterol, with a cholestanol:cholesterol ratio higher than that in the circulation. Because of its ability to convert cholesterol into polar metabolites that leave the cells faster, CYP27A1 has been suggested to be an antiatherogenic enzyme. The hypothesis was tested that tendons contain CYP27A1 that may be of importance for the normal efflux of both steroids.

METHODS AND RESULTS

Western blotting and combined gas chromatography-mass spectrometry showed that human tendons contain significant amounts of CYP27A1 and its product, 27-hydroxycholesterol. Immunohistochemistry showed that CYP27A1 is present in macrophages and tenocytes. The tendons also contained cholestanol, with a cholestanol:cholesterol ratio slightly higher than that in the circulation. Recombinant human CYP27A1, and cultured human macrophages containing this enzyme, had similar activity toward cholesterol and cholestanol. After loading of macrophages with labeled cholesterol and cholestanol, there was an efflux of these steroids in both unmetabolized and 27-oxygenated form, resulting in a significant cellular accumulation of cholestanol compared with cholesterol.

CONCLUSION

The results are consistent with the possibility that CYP27A1 is of importance for the efflux of both cholesterol and cholestanol from tendons.

Calf muscle function after Achilles tendon rupture. A prospective, randomised study comparing surgical and non-surgical treatment

In a prospective, randomised, multicentre study, 112 patients with Achilles tendon rupture (ATR) were allocated to surgical treatment (n=59), followed by early functional rehabilitation using a brace, and non-surgical treatment (n=53), i.e. eight weeks of plaster treatment. In this study, the results of the isokinetic muscle strength evaluation are presented for contractions in both the concentric and the eccentric mode, plantar flexion and dorsiflexion, two angular velocities and three different positions of the subject. The heel-raise test for endurance, maximum calf circumference and tendon width were also evaluated. The re-rupture rate was 20.8% in the non-surgically-treated group and 1.7% in the surgically-treated group. No significant differences were found between the treatment groups in terms of the isokinetic strength measurements and the endurance test among the patients who did not sustain a re-rupture. If a re-rupture is avoided, both surgical and non-surgical treatment for ATR produce good functional outcome; however, the muscle function was not restored after two years in either group.

Observer reliability in the arthroscopic classification of osteoarthritis of the knee

We studied 19 videotaped knee arthroscopies in 19 patients with mild to moderate osteoarthritis (OA) of the knee in order to compare the intraobserver and interobserver reliability and the patterns of disagreement between four orthopaedic surgeons. The classifications of OA of Collins, Outerbridge and the French Society of Arthroscopy were used. Intraobserver and interobserver agreements using kappa measures were 0.42 to 0.66 and 0.43 to 0.49, respectively. Only 6% to 8% of paired intraobserver classifications differed by more than one category. Observer-specific disagreement was evident both within and between observers. A small, but significant, occasional variation was also seen. Although reliability may improve by an analysis of disagreement, it appears that the arthroscopic grading of early osteoarthritic lesions is inexact.

The ultrasonographic appearance of the ruptured Achilles tendon during healing: a longitudinal evaluation of surgical and nonsurgical treatment, with comparisons to MRI appearance

This prospective, randomized trial compared healing characteristics of the Achilles tendon after surgical and nonsurgical treatment for complete rupture of the Achilles tendon. Fifty-eight patients were examined by ultrasonography after 6, 12, and 24 months and by magnetic resonance imaging after 12 months. A standardized protocol was used, and the outcome was correlated with clinical findings. Common findings 1 year after the injury were tendon thickening and moderate heterogeneity of the tendon. Peritendinous reactions, edema, and defects were present only in a minority of patients. There were no significant differences between the treatment groups in any of the evaluated parameters apart from the gliding function of the tendon, which was significantly less in the surgically treated group than in the nonsurgically treated group. No correlations were found between the radiological findings and the clinical parameters, such as muscle strength, endurance, and range of motion. We conclude that 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.

Observer reliability in the arthroscopic classification of osteoarthritis of the knee

We studied 19 videotaped knee arthroscopies in 19 patients with mild to moderate osteoarthritis (OA) of the knee in order to compare the intraobserver and interobserver reliability and the patterns of disagreement between four orthopaedic surgeons. The classifications of OA of Collins, Outerbridge and the French Society of Arthroscopy were used. Intraobserver and interobserver agreements using kappa measures were 0.42 to 0.66 and 0.43 to 0.49, respectively. Only 6% to 8% of paired intraobserver classifications differed by more than one category. Observer-specific disagreement was evident both within and between observers. A small, but significant, occasional variation was also seen. Although reliability may improve by an analysis of disagreement, it appears that the arthroscopic grading of early osteoarthritic lesions is inexact.

Donor-site morbidity and anterior knee problems after anterior cruciate ligament reconstruction using autografts

The authors review the current knowledge on donor site-related problems after using different types of autografts for anterior cruciate ligament (ACL) reconstruction and make recommendations on minimizing late donor-site problems. Postoperative donor-site morbidity and anterior knee pain following ACL surgery may result in substantial impairment for patients. The selection of graft, surgical technique, and rehabilitation program can affect the severity of pain that patients experience. The loss or disturbance of anterior sensitivity caused by intraoperative injury to the infrapatellar nerve(s) in conjunction with patellar tendon harvest is correlated with donor-site discomfort and an inability to kneel and knee-walk. The patellar tendon at the donor site has significant clinical, radiographic, and histologic abnormalities 2 years after harvest of its central third. Donor-site discomfort correlates poorly with radiographic and histologic findings after the use of patellar tendon autografts. The use of hamstring tendon autografts appears to cause less postoperative donor-site morbidity and anterior knee problems than the use of patellar tendon autografts. There also appears to be a regrowth of the hamstring tendons within 2 years of the harvesting procedure. There is little known about the effect on the donor site of harvesting fascia lata and quadriceps tendon autografts. Efforts should be made to spare the infrapatellar nerve(s) during ACL reconstruction using patellar tendon autografts. Reharvesting the patellar tendon cannot be recommended due to significant clinical, radiographic, and histologic abnormalities 2 years after harvesting its central third. It is important to regain full range of motion and strength after the use of any type of autograft to avoid future anterior knee problems. If randomized controlled trials show that the long-term laxity measurements following ACL reconstruction using hamstring tendon autografts are equal to those of patellar tendon autografts, we recommend the use of hamstring tendon autografts because there are fewer donor-site problems.

Acute rupture of tendo Achillis

In a prospective, randomised, multicentre study, 112 patients (99 men and 13 women, aged between 21 and 63 years) with acute, complete rupture of tendo Achillis were allocated either to surgical treatment followed by early functional rehabilitation, using a brace, or to non-surgical treatment, with plaster splintage for eight weeks. The period of follow-up was for two years. Evaluation was undertaken by independent observers and comprised interviews, clinical measurements, isokinetic muscle performance tests, heel-raise tests and an overall outcome score.

The rate of rerupture was 20.8% after non-surgical and 1.7% after surgical treatment (p < 0.001). Surgical and non-surgical treatment produced equally good functional results if complications were avoided. However, the rate of rerupture after non-surgical treatment was unacceptably high.

Acute rupture of tendon Achillis. A prospective randomised study of comparison between surgical and non-surgical treatment

In a prospective, randomised, multicentre study, 112 patients (99 men and 13 women, aged between 21 and 63 years) with acute, complete rupture of tendo Achillis were allocated either to surgical treatment followed by early functional rehabilitation, using a brace, or to non-surgical treatment, with plaster splintage for eight weeks. The period of follow-up was for two years. Evaluation was undertaken by independent observers and comprised interviews, clinical measurements, isokinetic muscle performance tests, heel-raise tests and an overall outcome score. The rate of rerupture was 20.8% after non-surgical and 1.7% after surgical treatment (p < 0.001). Surgical and non-surgical treatment produced equally good functional results if complications were avoided. However, the rate of rerupture after non-surgical treatment was unacceptably high.

Evaluation of harvested and normal patellar tendons: a reliability analyses of magnetic resonance imaging and ultrasonography

This study compared the reliability (interchangeability) of magnetic resonance imaging (MRI) and ultrasonography (US) examinations of the patellar tendon after using central third patellar tendon autografts during anterior cruciate ligament reconstruction. Nineteen consecutive patients (7 women, 12 men) underwent bilateral MRI and US of the patellar tendons 27 (24-29) months after anterior cruciate ligament reconstruction using ipsilateral central third patellar tendon autografts. Two experienced radiologists blinded to one another evaluated the examinations. Measurements of the length of the noninjured patellar tendon showed the greatest reliability between MRI and US, with no systematic difference (P=0.48), a small mean difference (-0.1 mm), and an interclass correlation coefficient of 0.74. The measurements of the thickness and width of the noninjured side were also judged as reliable. However, on the injured side a lower reliability was found between MRI and US. We conclude that MRI and US are reliable (interchangeable) methods only for evaluating noninjured patellar tendons.

Tendon tissue sampling

Mechanical load is regarded as the most important etiologic factor in cumulative trauma disorders affecting human tendons. At present there is limited knowledge concerning adaptation and the influence of training on human tendon tissue and the time process of developing a chronic tendon disorder. Tendon tissue samples and data concerning tendon pathology and repair have been derived from biopsies removed during surgery for rupture or pain conditions and from autopsy material. The ultrasound-guided percutaneous core biopsy technique provides the possibility to obtain tendon tissue from human Achilles and patellar tendon with limited discomfort for the individual. The specimens can be used for diagnostic purposes or for research and have the potential to highlight novel knowledge in, for example, the early stages of painful human tendon disorders. The fact that the procedure is invasive is a limitation. Autopsy material has limitations regarding poor information on case history, post mortem alterations and legal regulations on the use of tissue for medical purposes. The inflammatory process quickly affects ruptured tendons. The subcutaneous tendons that sustain a rupture are commonly characterized by degenerative alterations. Many tendon ruptures are treated with surgery, facilitating easy access to biopsy material. In summary, tendon tissue sampling in humans has obvious limitations. The recently described use of the core biopsy technique in human tendon research and diagnosis gives potential for new knowledge concerning human tendon adaptation, repair and disease.

A radiographic and histologic evaluation of the patellar tendon after harvesting its central third

Nineteen consecutive patients undergoing anterior cruciate ligament reconstruction using the central third of the ipsilateral patellar tendon were included in the study. Serial magnetic resonance images revealed that the donor-site gap in the tendon decreased with time (mean follow-up, 26 months). The thickness was significantly increased compared with the intact contralateral patellar tendon, regardless of when the magnetic resonance imaging was performed. Ultrasonography showed the same findings at a mean follow-up of 26 months. Histologic evaluation of the repair tissue in the central part of the tendon, as well as the tissue in the peripheral part of the patellar tendon at the donor site, revealed a significant increase in cellularity and vascularity as compared with normal control tendons. Thus, 2 years after the harvesting procedure, the patellar tendon displayed significant radiographic and histologic abnormalities. On the basis of these findings, reharvest of the patellar tendon, at least up to 2 years after primary harvest, cannot be recommended.

Function after Achilles tendon rupture in the elderly: 25 patients older than 65 years followed for 3 years

We retrospectively analyzed the function after Achilles tendon rupture in 25 patients older than 65 years, 3 (1-5) years after the initial treatment. The patients' median age at the time of injury was 71 (65-86) years. The initial management was surgical in 14 patients and non-surgical (8-week immobilization) in 10, 1 patient was not treated. The ratio of the number of heel-raises on the injured to the uninjured side was median 0.64 (0-1.14), showing a reduction in performance. However, in both surgically- and non-surgically-treated patients, the subjective impairment was mild, and the patients were able to perform most walking activities. Only 9 patients reached their previous activity level. Co-morbidity was frequent: 17 patients had other diseases that affected their performance. 14 complications occurred in 11 patients. 5 patients sustained a rerupture (4 following initial closed treatment with plaster), 1 a deep venous thrombosis and 4 had superficial infections requiring antibiotic treatment. 1 patient sustained a fibular nerve injury following compression by the plaster cast and another a sural nerve injury during the operation. 2 patients had symptoms due to adhesions between the tendon and the skin. We conclude that Achilles tendon rupture in patients older than 65 years reduces lower limb function and that complications are common following surgical and non-surgical treatment.

3D-radiographic analysis does not improve the Neer and AO classifications of proximal humeral fractures

The Neer and AO fracture classifications for fractures of the proximal humerus have shown poor reproducibility based on plain radiography. We wanted to investigate whether the addition of 3-dimensional (3D) reconstructions would increase the reproducibility of classification. 7 observers independently classified 24 fractures of the proximal humerus using both plain radiographs, CT and 3D and the classification was repeated 2 months later. There was a moderate interobserver agreement when using the Neer classification, but only a fair agreement with the AO classification. The Neer system had a mean kappa value of 0.44 and the AO had a value of 0.32 for the first assessment. In the second assessment, the mean kappa values were 0.49 and 0.34, respectively. Intraobserver reproducibility was fair to substantial agreement for Neer (kappa range 0.27-0.73) and for AO (kappa range 0.29-0.74). In conclusion, the addition of CT and 3D to plain radiographs did not improve the reproducibility of the classifications of Neer and AO of the proximal humerus.

Function after anterior cruciate ligament injuries. Influence of visual control and proprioception

Information about limb positions and movements consists of input from visual, vestibular, cutaneous, muscular, tendinous and joint receptors, but the relative contribution from each type and location of receptors is not known. The aim of this study was: a) to measure the contribution from visual control on extremity function, as measured with a one-leg hop test in healthy persons, in patients with an asymptomatic ACL injury, after non-operative treatment and in patients with a stable knee after an ACL reconstruction, b) to investigate if there was any relation between proprioception from the extremity, as measured with the threshold for detecting passive motion of the knee, and the one-leg hop test with a gradual decrease in visual control. There was a decrease in hop-length when the subjects were deprived of visual control that was significant when the dominant eye or both eyes were blinded, both in the 2 patient groups and the reference population. The magnitude of the length reduction did not differ between the groups or between injured and healthy limbs. In all 4 threshold tests performed as a measure of peripheral proprioception, a stronger relation to hop-length was recorded for the blinded hop than with full visual control in the patients with nonoperated ACL injuries. The coefficients of correlation between hop-length and the proprioceptive recordings in the injured limb were of the same magnitude as on the healthy side.

Poor function after shoulder replacement in fracture patients. A retrospective evaluation of 29 patients followed for 2-12 years

We evaluated the functional outcome 3 (2-12) years after arthroplasty in 29 proximal humerus fractures. The patients' average age at the time of surgery was 71 (47-87) years. The follow-up included a full clinical examination by an independent observer, a questionnaire concerning activities of daily living and pain, and radiographs. The shoulders had a marked reduction of performance, with a Constant score mean of 38 (16-69). All patients were able to eat with utensils, 10 could comb their hair, 19 managed to wash the contralateral armpit, 3 could reach the back pocket and 12 were able to take care of the perineal area. On the VAS-scale (0-100 mm), pain at rest was mean 21 (0-53) mm and on motion 47 (0-91) mm. The patients were stratified regarding surgical treatment within 3 weeks (18 acute vs. 11 late) and prosthetic design (14 Neer II vs. 14 Global modular) without significant differences, as assessed by the Constant scores. We conclude that the treatment of severe proximal humerus fractures with a prosthesis does not give complete pain relief and results in impaired shoulder function.

Intratendinous alterations as imaged by ultrasound and contrast medium-enhanced magnetic resonance in chronic achillodynia

OBJECTIVES

We performed a comparative study of ultrasonography and gadolinium imaging contrast-enhanced T1-weighted magnetic resonance to evaluate tendon pathology in chronic Achilles tendon disorder. Another main issue was to evaluate the structural basis as defined by histopathology from hypoechoic compared with normoechoic areas within the same tendon.

MATERIALS AND METHODS

Twenty patients (16 male, 4 females, median age 40 years) with chronic achillodynia participated in the study. Clinical examination revealed swelling and tenderness localized to the midportion of the Achilles tendon. Contrast medium-enhanced magnetic resonance imaging (CME-MRI) was performed in all patients. Ultrasonography-guided core biopsies were taken from regions with a clear widening of the tendon and a pathologic low-echo signal as well as from normoechoic areas. The specimens were analyzed with a standardized protocol giving a total tendon score (0-24), and a stereologic method for quantification of glycosaminoglycan (GAG)-rich areas.

RESULTS

The volume of the intratendinous abnormality was larger in 13 of 20 when imaged by CME-MR (P < 0.05), whereas the shape and enlargement of the tendon per se were similarly imaged by ultrasound (US) and CME-MR. Tendon pathology as imaged by US was graded as severe from hypoechoic regions and moderate from normoechoic regions. The corresponding quantification of GAGs was 0.36 compared with 0.17, respectively (P < 0.001).

CONCLUSION

CME-MR imaging revealed greater sensitivity in demonstrating intratendinous pathology than the ultrasound; this was documented by the larger size of the corresponding lesion and the fact that the pathology was occurring in areas that were considered normal by ultrasonography. US hypoechoic areas showed a markedly abnormal tendon structure including an increased amount of GAG-rich areas. However, moderate pathology was also found in the neighboring normoechogenous areas within the same tendon, indicating a more generalized disorder than depicted by echogenic properties.

MR imaging in chronic Achilles tendon disorder

OBJECTIVES

The primary objective was to compare 4 imaging sequences (T1-weighted, T2-weighted, proton density, and T1-weighted with gadolinium contrast agent enhancement) with regard to intratendinous signal abnormality in patients with achillodynia. The secondary objective was to relate the images to the clinical symptoms and histopathological findings.

MATERIAL AND METHODS

Twenty patients (16 men, 4 women, median age 40 years) with chronic achillodynia participated in the study. The symptoms prohibited activity and clinical examination revealed swelling and tenderness 1.5-6 cm proximal to the Achilles tendon insertion. Of the 20 patients: 5 had bilateral achillodynia, 4 had had previous contralateral Achilles tendon disorder, and 11 had never had symptoms in the contralateral tendon region. These 11 tendons served as controls for comparison. MR imaging was performed on a superconductive 1.5 T unit. Both Achilles tendons were examined (n = 40) at the same time, and multiple sagittal and transversal images were obtained. The corresponding sections on these images were visually graded according to both extension and level of MR signal intensity. Tissue was obtained for microscopic examination from the most symptomatic side in all patients (n = 20).

RESULTS

T1-weighted images following gadolinium contrast medium enhancement proved to be the best method by which to visualize intratendinous signal abnormality. This sequence revealed signal abnormality in 24/25 symptomatic tendons and in 1/11 control tendons (p < 0.001). Histopathological examination showed an increased noncollagenous extracellular matrix and altered fiber structure in the lesions corresponding to the contrast-enhanced areas.

CONCLUSION

Gadolinium enhancement improved the imaging of intratendinous signal abnormality on T1-weighted images. There was a high level of extracellular glycosaminoglycans, which are highly-fixed negatively-charged macromolecules with extreme water-retaining capacity and which may have contributed to the enhancement by the gadolinium contrast agent.

Etiology, histopathology, and outcome of surgery in achillodynia

Fifty-eight patients suffering from achillodynia for a median of 12 months (range, 4-240 months) were analyzed using history, clinical findings, ultrasound findings, histopathology, and surgical outcome. Surgical criteria were daily pain or inability to perform sports activity and failure of nonoperative treatment. There were 34 men and 24 women, 31% (18 of 58 patients) of whom had no direct association with sports or vigorous physical activity. Ultrasonography was performed in all cases and showed low echogenous areas (N = 48), increased tendon diameter (N = 40), and/or peritendinous fluid (N = 11). Histopathological evaluation of tendon biopsies, obtained from regions showing pathology at surgery (N = 35), revealed altered fiber structure and arrangement, focal variations in cellularity, extracellular glycosaminoglycans, neovascularization, and/or hyalinization. In no case was inflammatory cell infiltration observed. At a median clinical follow-up of 25 months after surgery, symptoms were decreased in 86% of patients, and 76% had reached a higher activity level compared with the level before surgery. Complications occurred in 13% of operations. In conclusion, achillodynia is not always associated with excessive physical activity. Macroscopic pathologic tendons showed marked histopathologic changes, correlating well with ultrasound findings. Surgical treatment was beneficial in most cases, despite a relatively high complication rate. The etiology and reason for the lack of healing response to rest and nonoperative treatment are unclear.

An open, randomized study of ketoprofen in patients in surgery for Achilles or patellar tendinopathy

OBJECTIVE

To assess the concentration of ketoprofen, after topical plaster application, in various tissues in relation to plasma levels in 60 patients undergoing surgery for Achilles or patellar tendinopathy; and to analyze whether tissues act as a reservoir of ketoprofen, by evaluating tissue concentrations in relation to plasma concentration at various time points after removal of the plaster. No attempt was made to study the clinical effect of treatment per se.

METHODS

In random order to patients applied 30 mg plasters once daily for 5 consecutive days (n = 30), or took a single oral dose 50 mg (n = 30) before surgery. Tissue samples of skin, subcutaneous fat, tendon sheath, and tendon, and plasma were collected intraoperatively at 0, 6 and 14 hours after removal of the 5th plaster, and at 2, 6, and 14 hours after oral intake. Ketoprofen concentration was determined by a validated GC/MS method. The low limit of quantification was 0.5 ng/ml plasma and 0.5 ng/50 mg tissues.

RESULTS

High concentrations of ketoprofen were observed in fat, tendon sheath, and tendon after topical applications, whereas plasma levels of ketoprofen were low.

CONCLUSION

Ketoprofen attains high concentrations in subcutaneous tissues after multiple topical applications. Subcutaneous tissues appear to act as a reservoir of ketoprofen.

Ultrasonography-guided percutaneous core biopsy in Achilles tendon disorder

Ultrasound-guided percutaneous core biopsy technique was studied in 15 consecutive patients with chronic Achilles tendon disorder defined as persisting local pain during daily activities, localized pain and swelling on palpation 2-5 cm proximal to the calcaneal insertion. Ultrasound verified widening of the tendon and low echogenous areas at the site of pain. Percutaneous biopsies were taken from both the low echogenous areas and the normoechogenic tendon tissue. Of 104 core biopsies 99 were representative. Open biopsies were taken from the macroscopically injured and normal tendon for comparison. Core and open biopsies of the low echogenous and macroscopically injured tendon showed similar histopathology. In 10 patients the core biopsy was performed under local anesthesia with limited subjective symptoms. Five of these patients were operated 18-41 days later. No adverse effect was found referring to the biopsy taken a few weeks prior to surgery. No complications occurred. We conclude that the percutaneous core biopsy, guided by ultrasound and performed under local anesthesia, can be used under clinical and experimental in vivo studies for improving knowledge on pathoanatomy and healing processes of the Achilles tendon.

Poor reproducibility of classification of proximal humeral fractures. Additional CT of minor value

Fractures of the proximal humerus can be described using the Neer and AO fracture classifications. To assess the reproducibility and reliability of these classifications, we investigated 26 proximal humeral fractures with both plain radiographs and CT. 5 specialists in orthopedic surgery and 5 specialists in radiology independently classified all radiographs on 2 occasions. There was a moderate agreement between the observers when using the Neer classification, but only a fair agreement with the AO classification. The Neer system had a kappa value of 0.42 and the AO had a value of 0.31 in the first assessment. In the second assessment the kappa values were 0.45 and 0.30, respectively. Intraobserver reproducibility was slight to almost perfect agreement with Neer (kappa range 0.20-0.85) and slight to moderate agreement with AO (kappa range 0.16-0.60). The observers most familiar with shoulder fracture radiographs and shoulder fracture treatment were more consistent in their classifications. We conclude that even with CT, the fracture classifications of Neer and AO have a low consistency. Neither classification system is reproducible enough to allow comparisons of different studies.