Common Extensor Research Articles

重種子馬の総指伸筋腱断裂を疑った1例

重種子馬の総指伸筋腱断裂を疑った1例

An Assembly of Anomalous Extensor Tendons of the Hand - Anatomical Description and Clinical Relevance.

Innumerable descriptions about variations in the pattern of extensor tendons are recorded in the literature. The dorsum of the hand in an adult male cadaver revealed an unusual pattern of extensor arrangement during a gross anatomical practical session. The extensor digitorum, extensor indicis and extensor digiti minimi tendons displayed a variant pattern. Extensor digitorum contributed tendons only to the middle and ring fingers, with junctura tendinum present between the extensor digitorum for the ring finger and extensor digiti minimi. Interestingly, an accessory muscle was observed arising from the common extensor origin passing to the index finger, in addition to the usual extensor indicis. The origin and insertion of extensor digiti minimi was as usual with an accessory slip contributed from the extensor carpi ulnaris to the proximal phalanx of the fifth finger. The plethora of variations in this region is of paramount importance for the reconstructive surgeon, who may utilize the accessory tendons to restore functional capacity of the fingers.

Arthroscopic, Macroscopic, and Microscopic Anatomy of the Synovial Fold of the Elbow Joint in Correlation With the Common Extensor Origin

Arthroscopic, Macroscopic, and Microscopic Anatomy of the Synovial Fold of the Elbow Joint in Correlation With the Common Extensor Origin

Physical activity: does long-term, high-intensity exercise in horses result in tendon degeneration?

This study explores the hypothesis that high-intensity exercise induces degenerative changes in the injury-prone equine superficial digital flexor tendon (SDFT), but not in the rarely injured common digital extensor tendon (CDET). The horse represents a large-animal model that is applicable to human tendon and ligament physiology and pathology. Twelve age-matched female horses undertook galloping exercise three times a week with trotting exercise on alternative days (high-intensity group, n = 6) or only walking exercise (low-intensity group, n = 6) for 18 mo. The SDFT, suspensory ligament, deep digital flexor tendon, and CDET were harvested from the forelimb. Tissue from the mid-metacarpal region of the right limb tendons was analyzed for water, DNA, sulfated glycosaminoglycan and collagen content, collagen type III-to-I ratios, collagen cross-links, and tissue fluorescence. Left limb tendons were mechanically tested to failure. The analyses showed matrix composition to have considerable diversity between the functionally different structures. In addition, the specific structures responded differently to the imposed exercise. High-intensity training resulted in a significant decrease in the GAG content in the SDFT, but no change in collagen content, despite a decrease in collagen fibril diameters. There were no signs of degeneration or change in mechanical properties of the SDFT. The CDET had a lower water content following high-intensity training and a higher elastic modulus. Long-term, high-intensity training in skeletally mature individuals results in changes that suggest accelerated aging in the injury-prone SDFT and adaptation in the CDET.

“Tenomalacia”: a new sonographic sign of tendinopathy?

The purpose of this study was to assess tendon compressibility with sonography in extensor tendinopathy and in asymptomatic extensor tendons of the elbow. Sonography of both elbows was performed in eight patients with a clinical diagnosis of unilateral lateral epicondylitis. Tendons were assessed for compressibility by measuring their thickness before and after compression with the transducer. The same manoeuvre was performed while tendon vascularity was assessed with colour Doppler. All eight cases showed increased compressibility of the common extensor tendon on the painful side compared to the asymptomatic side, as well as increased vascularity with compressible vessels on colour Doppler. Other signs of tendinopathy were hypoechogenicity (n = 8), loss of fibrillar pattern (n = 8), intratendinous calcifications (n = 1), partial tears (n = 3), and enthesophytes (n = 5). Increased tendon compressibility indicative of tendon softening or "tenomalacia" is a new sonographic sign of common extensor tendinopathy.

Sonographically Guided Percutaneous Needle Tenotomy for Treatment of Common Extensor Tendinosis in the Elbow

Chronic refractory common extensor tendinosis of the lateral elbow has been shown to respond to sonographically guided percutaneous needle tenotomy (PNT) followed by corticosteroid injection. In this analysis, we attempted to determine whether the corticosteroid is a necessary component of the procedure. We performed PNT on 57 consecutive patients (age range, 34-61 years) with persistent pain and disability resulting from common extensor tendinosis. Under a local anesthetic and sonographic guidance, a needle was advanced into the tendon, and the tip of the needle was used to fenestrate the tendinotic tissue, break up any calcifications, and abrade the adjacent bone. After the procedure, patients underwent a specified physical therapy protocol. During a subsequent telephone interview, patients answered questions about their symptoms, the level of functioning, and perceptions of the procedure outcome. Of the 52 patients who agreed to participate in the study, 30 (57.7%) reported excellent outcomes, 18 (34.6%) good, 1 (1.9%) fair, and 3 (5.8%) poor. The average follow-up time from the date of the procedure to the telephone interview was 22 months (range, 7-38 months). No adverse events were reported, and 90% stated that they would refer a friend or close relative for the procedure. Sonographically guided PNT for refractory lateral elbow tendinosis is an effective procedure, and subsequent corticosteroid injection is not necessary.

Evaluation of computed tomographic anatomy of the equine metacarpophalangeal joint

To determine the detailed computed tomography (CT) anatomy of the metacarpophalangeal (MCP) joint in healthy horses. 10 cadaveric forelimbs from 10 adult horses without orthopedic disease. CT of the MCP joint was performed on 4 forelimbs. In 1 of the limbs, CT was also performed after intra-articular injection of 30 mL of contrast medium (40 mg of iodine/mL). Transverse slices 1-mm thick were obtained, and sagittal and dorsal planes were reformatted with a slice thickness of 2 mm. The CT images were matched with corresponding anatomic slices from 6 additional forelimbs. The third metacarpal bone, proximal sesamoid bones, and proximal phalanx could be clearly visualized. Common digital extensor tendon; accessory digital extensor tendon; lateral digital extensor tendon; superficial digital flexor tendon (including manica flexoria); deep digital flexor tendon; branches of the suspensory ligament (including its attachment); extensor branches of the suspensory ligament; collateral ligaments; straight, oblique, and cruciate distal sesamoidean ligaments; intersesamoidean ligament; annular ligament; and joint capsule could be seen. Collateral sesamoidean ligaments and short distal sesamoidean ligaments could be localized but not at all times clearly identified, whereas the metacarpointersesamoidean ligament could not be identified. The cartilage of the MCP joint could be assessed on the postcontrast sequence. CT of the equine MCP joint can be of great value when results of radiography and ultrasonography are inconclusive. Images obtained in this study may serve as reference for CT of the equine MCP joint.

Extra-articular Arthroscopic Lateral Elbow Release

We describe a unique extra-articular approach for arthroscopic lateral release for lateral epicondylitis. An arthroscopic extra-articular approach allows better direct visualization of diseased structures with a 30° arthroscope and only requires a small hole in the joint capsule. The camera is placed into the joint through the middle anterolateral portal. The camera is then pulled back through a small rent in the capsule over the lateral radiocapitellar joint to provide an extra-articular view of the diseased structures. The shaver is then placed 1.5 cm proximal to the camera in a proximal anterolateral portal. Debridement of the common extensor fiber tendinosis and decortication of the lateral epicondyle are performed under direct visualization. This is different from the intra-articular technique, where visualization with the 30° arthroscope is more difficult despite a large capsulotomy to aid visualization. The advantage of this extra-articular technique is 2-fold. First, the extra-articular viewing portal allows direct visualization of diseased structures, improving accuracy for debridement compared with an intra-articular viewing portal. The intra-articular technique uses the 30° arthroscope to work around a corner after a large capsulectomy. The second advantage of the extra-articular viewing portal is that it only requires a small capsulotomy. The small capsulotomy decreases the risk of transient radial nerve palsy associated with a capsulectomy. The small capsulotomy also results in less fluid extravasation into the soft tissues. Less fluid extravasation decreases swelling and the risk of compartment syndrome.

Unusual accessory tendon connecting the hallucal extensors

During routine dissection of an adult human cadaver, a suite of tendinous anomalies was discovered in the left hallucal region. Whereas the main tendon of the extensor hallucis longus muscle inserted normally, two accessory tendons were found coursing medial and lateral to the main tendon. The most lateral tendon originated from a supernumerary muscle belly and merged with the tendon of extensor hallucis brevis to form a composite tendon. The most medial tendon crossed the metatarsophalangeal joint and joined the composite tendon deep to the tendon of extensor hallucis longus. A terminal tendon, consisting of these three contributions, inserted upon the proximal hallucal phalanx. This variant likely arose due to atypical differentiation of the common extensor muscle mass during development, and is of particular significance to clinicians performing arthroscopy, tendon transfers, and other surgical procedures.

Effects of exercise on tenocyte cellularity and tenocyte nuclear morphology in immature and mature equine digital tendons

The injury-prone, energy-storing equine superficial digital flexor tendon (SDFT) of the mature performance horse has a limited ability to respond to exercise in contrast with the noninjury-prone, anatomically opposing common digital extensor tendon (CDET). Previous studies have indicated low levels of cellular activity in the mature SDFT, but in foal tendons the tenocytes may still have the ability to adapt positively to increased exercise. To measure tenocyte densities and types in histological sections from the SDFT and CDET of horses from controlled long-term, short-term and foal exercise studies. Specimens were collected from mid-metacarpal segments of the CDET and SDFT for each horse and processed for histology; central and peripheral regions of the SDFT cross-section were analysed separately (SDFTc, SDFTp). Tenocyte nuclei were counted in a total area of 1.59 mm(2) for each tendon region in each horse. Each nucleus was classified as type 1 (elongate and thin), type 2 (ovoid and plump) or type 3 (chondrocyte-like); type 1 cells are proposed to be less synthetically active than type 2 cells. No significant differences were noted between exercise and control groups in any of the studies, with the exception of an exercise-related reduction in the proportion of type 1 tenocytes for all tendons combined in the long-term study. There were tendon- and site-specific differences in tenocyte densities and proportions of type 1 and 2 cells in all 3 studies. There was no indication that exercise increased tenocyte density or proportions of the (theoretically) more active type 2 cells in immature horses (short-term and foal studies), perhaps because the training regimens did not achieve certain threshold strain levels. In the foal study these findings can still be interpreted positively as evidence that the training regimen did not induce subclinical damage.

Diagnostic accuracy of power Doppler ultrasound in patients with chronic tennis elbow

Objective:To determine the diagnostic accuracy of power Doppler and grey scale ultrasonography, assess the relationship between severity measures and neovascularity, and describe the intra-tendon distribution of neovascularity in chronic tennis...

Effect of glucocorticosteroid injections in tennis elbow verified on colour Doppler ultrasonography: evidence of inflammation

Objectives:It has previously been reported that lateral epicondylitis may be diagnosed with colour Doppler ultrasonography (US) by detecting hyperaemia inside the common extensor origin (CEO).This study reports on the association...

Primary Ligament Repair for Elbow Dislocation

Few have been reported on the role of early primary ligament repair for acute unstable elbow dislocation. The purpose of this study is to evaluate the clinical outcome of early primary ligament repair for unstable elbow dislocation followed by protected early joint mobilization exercise. Thirteen patients who underwent operative treatment due to unstable elbow dislocation without associated fracture were retrospectively reviewed. There were 11 male and 2 female with average age of 37 years (range; 18-72 years). Surgical indications of the unstable elbow were subluxation or non-congruent elbow joint on the radiographs following closed reduction. Elbow dislocation which required extension block splint over 45 degrees to maintain reduction was considered as unstable elbow dislocation. In ten patients, full stability was restored only after both medial and lateral structures were re-attached. In two patients, only lateral structure (LCLC and common extensor tendon) was repaired and in one patient, only medial structure (MCL and flexor pronator tendon) was repaired for stability. Overall mean functional Mayo Elbow Performance Score was 93.5 (range; 70-100). No elbow was dislocated or subluxated after operation. All ten patients returned to previous work level in average of 3.5 months. Heterotopic calcification was noted in six patients and three had mild ulnar nerve symptoms after operation. In conclusion, primary ligament repair in acute unstable elbow dislocation were successful, because surgery achieved sufficient stability to allow early exercise.

The Effect of Oscillating-energy Manual Therapy on Lateral Epicondylitis: A Randomized, Placebo-control, Double-blinded Study

Symptoms of lateral epicondylitis (LE) are attributed to degenerative changes and inflammatory reactions in the common extensor tendon induced by microscopic tears in the tissue after repetitive or overload functions of the wrist and hand extensor muscles. Conventional treatments, provided on the premise of inflammatory basis of LE, have shown 39–80% failure rate. An alternative approach suggests that symptoms of LE could be due to active tender points developed in the origin of hand and wrist extensor muscles after overuse or repetitive movements. Oscillating-energy Manual Therapy (OEMT), also known as V-spread, is a craniosacral manual technique that has been clinically used for treating tender points over the suture lines in the skull. Considering symptoms of LE may result from active tender points, the purpose of this study was to investigate the effect of OEMT on pain, grip strength, and functional abilities of subjects with chronic LE. Twenty-three subjects with chronic LE (>3 mo) between ages of 24 and 72 years participated in this study. Before their participation, all subjects were screened to rule out cervical and other pathologies that could possibly contribute to their lateral elbow pain. Subjects who met the inclusion criteria were randomized into treatment and placebo treatment groups by a second (treating) therapist. Subjects were blinded to their group assignment. Subjects in the treatment group received OEMT for six sessions. During each treatment session, first a tender point was located through palpation. After proper hand placement, the therapist focused the direction of the oscillating energy on the localized tender point. Subjects in the placebo group underwent the same procedure, but the direction of the oscillating energy was directed to an area above or below the tender points, not covering the affected area. Jamar Dynamometer, Patient Specific Functional Scale (PSFS), and Numeric Rating Scale (NRS) were used to measure grip strength, functional status, and pain intensity and limited activity due to pain, respectively. The screening therapist who was blinded to the subjects' group assignment performed pretest, posttest, and six-month follow-up measurements. Subjects in the treatment group showed both clinically and statistically significant improvement in grip strength (p = 0.03), pain intensity (p = 0.006), function (p = 0.003), and limited activity due to pain (p = 0.025) compared with those in the placebo group. Follow-up data, collected after six months, showed no significant difference between posttest and follow-up measurements in functional activity (p = 0.35), pain intensity (p = 0.72), and activity limitation due to pain (p = 0.34). Of all the subjects contacted for follow-up assessment, 91% maintained improved function and 73% remained pain free for at least six months. OEMT seems to be a viable, effective, and efficient alternative treatment for LE.

Arthroscopic, Macroscopic, and Microscopic Anatomy of the Synovial Fold of the Elbow Joint in Correlation With the Common Extensor Origin

The objective of our study was to clarify the arthroscopic, macroscopic, and microscopic anatomy of the radiocapitellar synovial fold of the elbow joint in correlation with the common extensor origin. We performed arthroscopy in 14 fresh-frozen cadaveric elbows and found the synovial fold covering the radial head or interposing in the radiocapitellar joint in 6. The fold was tagged with loop suture under arthroscopy to identify its exact location in gross anatomy. The radiocapitellar joint capsule was then resected without disturbing the continuity of the common extensor and lateral epicondyle. Macroscopic and histologic evaluation was performed for the lateral elbow capsular complex. The synovial fold was found to be a triangular-shaped thickening of the capsule located on the proximal edge of the annular ligament. The mean distance between the lateral epicondyle and the base of the fold at the anterior edge, middle part, and posterior edge was 23 mm, 8 mm, and 13 mm, respectively. This structure was distinct from the annular ligament but was continuous with the radiocapitellar joint capsule. The joint capsule and the common extensor tendon blended with each other imperceptibly and formed a single enthesis at the lateral epicondyle. The synovial fold identified by arthroscopy is a physiologic capsular tissue located on the proximal edge of the annular ligament. It is distinct from the annular ligament but has a close correlation with the common extensor tendon enthesis at the lateral epicondyle. The synovial fold belongs to the lateral epicondyle enthesis, which is a composite of the common extensor tendon, undersurface capsule, and bone. Therefore, lateral epicondylitis with degenerative lesions in the area of the common extensor origin may involve the synovial fold and induce hypertrophic changes.

Matrix metabolism rate differs in functionally distinct tendons

Tendon matrix integrity is vital to ensure adequate mechanical properties for efficient function. Although historically tendon was considered to be relatively inert, recent studies have shown that tendon matrix turnover is active. During normal physiological activities some tendons are subjected to stress and strains much closer to their failure properties than others. Tendons with low safety margins are those which function as energy stores such as the equine superficial digital flexor tendon (SDFT) and human Achilles tendon (AT). We postulate therefore that energy storing tendons suffer a higher degree of micro-damage and thus have a higher rate of matrix turnover than positional tendons. The hypothesis was tested using tissue from the equine SDFT and common digital extensor tendon (CDET). Matrix turnover was assessed indirectly by a combination of measurements for matrix age, markers of degradation, potential for degradation and protein expression. Results show that despite higher cellularity, the SDFT has lower relative levels of mRNA for collagen types I and III. Non-collagenous proteins, although expressed at different levels per cell, do not appear to differ between tendon types. Relative levels of mRNA for MMP1, MMP13 and both pro-MMP3 and MMP13 protein activity were significantly higher in the CDET. Correspondingly levels of cross-linked carboxyterminal telopeptide of type I collagen (ICTP) were higher in the CDET and tissue fluorescence lower suggesting more rapid turnover of the collagenous component. Reduced or inhibited collagen turnover in the SDFT may account for the high level of degeneration and subsequent injury compared to the CDET.

FRACTIONAL LENGTHENING OF FOREARM EXTENSORS FOR RESISTANT LATERAL EPICONDYLITIS

This study presents the surgical technique of fractional lengthening of extensor carpi radialis brevis, extensor digitorum communis and the superficial head of supinator, for chronic lateral epicondylitis. The anatomical basis for this surgical approach is reviewed. The results of surgical treatment in a consecutive series of patients with severe chronic lateral epicondylitis are reviewed. Twenty-one elbows in 17 subjects underwent surgery. All elbows had severe resistant symptoms, unresponsive to a minimum 6 months (mean 14 months) of a non-operative treatment protocol. All elbows showed either tendonopathy or a partial tear in the common extensor tendon origin at preoperative imaging. All subjects were examined at a minimum of 1 year after surgery. The mean visual analogue pain (VAS) score reduced from 7.6 (maximum 10) preoperatively to 1.3 postoperatively (P<0.01). The mean preoperative ability to carry out normal work duties reduced from 4.3 (maximum 5) preoperatively to 1.5 postoperatively (P<0.01). Grip strength improved or remained equivalent following surgery. The mean VAS for patient satisfaction with surgery was 8.8 (maximum score 10). Using the Roles and Maudsley classification, 14 patients (82%) were rated good or excellent. Three subjects were rated fair or poor, were undergoing treatment for other pathology in the ipsilateral extremity and had ongoing compensation claims. Fractional lengthening of forearm extensors is effective treatment for severe and chronic lateral epicondylitis. Outcomes following fractional lengthening surgery are less predictable when other pathology in the upper extremity requires concomitant treatment.

Gap junction protein expression and cellularity: comparison of immature and adult equine digital tendons

Injury to the energy-storing superficial digital flexor tendon is common in equine athletes and is age-related. Tenocytes in the superficial digital flexor tendon of adult horses appear to have limited ability to respond adaptively to exercise or prevent the accumulation of strain-induced microdamage. It has been suggested that conditioning exercise should be introduced during the growth period, when tenocytes may be more responsive to increased quantities or intensities of mechanical strain. Tenocytes are linked into networks by gap junctions that allow coordination of synthetic activity and facilitate strain-induced collagen synthesis. We hypothesised that there are reductions in cellular expression of the gap junction proteins connexin (Cx) 43 and 32 during maturation and ageing of the superficial digital flexor tendon that do not occur in the non-injury-prone common digital extensor tendon. Cryosections from the superficial digital flexor tendon and common digital extensor tendon of 5 fetuses, 5 foals (1-6 months), 5 young adults (2-7 years) and 5 old horses (18-33 years) were immunofluorescently labelled and quantitative confocal laser microscopy was performed. Expression of Cx43 and Cx32 protein per tenocyte was significantly higher in the fetal group compared with all other age groups in both tendons. The density of tenocytes was found to be highest in immature tissue. Higher levels of cellularity and connexin protein expression in immature tendons are likely to relate to requirements for tissue remodelling and growth. However, if further studies demonstrate that this correlates with greater gap junctional communication efficiency and synthetic responsiveness to mechanical strain in immature compared with adult tendons, it could support the concept of early introduction of controlled exercise as a means of increasing resistance to later injury.

Imaging of the elbow

The elbow is a complex joint that is prone to injury. Rupture of the distal biceps tendon occurs at the insertion. Injury of the collateral ligaments can be assessed with dynamic ultrasound or MRI. Tennis elbow or tendinosis of the common extensor origin usually demonstrates increased vascularity on ultrasound. Synovitis is often non-specific on imaging. Osteochondritis dissecans occurs in an older age group and has a worse prognosis than Panner's disease. The diagnosis of loose bodies may be aided by arthrography. The elbow is a common site for entrapment neuropathies. This article outlines a practical approach to the imaging of pathological conditions of the elbow based on the clinical presentation. The appropriate use of the various imaging modalities is discussed.

Symposium: Tendon and ligament remodelling and regeneration

Symposium: Tendon and ligament remodelling and regeneration