Proximal Musculotendinous Junction Research Articles

POST SURGICAL STIFFNESS OF KNEE JOINT IN PIGMENTED VILLONODULAR SYNOVITIS: A RARE CASE REPORT

Introduction: Post-surgical knee stiffness is a debilitating complication and its treatment ranges from simple arthroscopic adhesiolysis to more extensive Quadricepsplasty. Physiotherapy rarely sufces in most cases. We are presenting a case of surgically intervened pigmented villonodular synovitis (PVNS) with stiff knee treated by open intraarticular adhesiolysis and a modied V-Y quadricepsplasty and extensor mechanism release, a rst of its kind. An Indian male in his 20s, a surgically intervened case Case Presentation: of PVNS lost to follow-up due to COVID-19 Lockdown presented with a stiff knee with movement of 0-30o exion in early 2022. An open adhesiolysis of the joint arthrobrosis using the previous incision was performed, and a separate full thickness V-shaped incision at proximal Musculo-tendinous junction of quadriceps tendon was given to achieve exion of 130°.The tendon was repaired in its lengthened position, giving the appearance of a V to Y. Post-operatively, muscles strengthening, and Range of motion (ROM) exercises including continuous passive motion (CPM), were included following a specic physiotherapy protocol immediately after surgery. 10 weeks post-op, the patient has 0-120° active and passive ROM of the knee with an extensor lag of 7°. A planned and proper surgical approach targeting the primary cause of sti Conclusion: ffness augmented with direct extensor mechanism lengthening procedures (quadricepsplasty) if needed, can achieve good per-operative knee ROM. Aggressive surgery specic postoperative physiotherapy and rehabilitation play a major role in achieving satisfactory results

Anatomical retraction of the semitendinosus muscle following harvest of the distal semitendinosus tendon for ACL reconstruction.

Retraction of semitendinosus muscle has been reported after reconstruction of the anterior cruciate ligament with semitendinosus/gracilis-graft. However, very little data exist on the natural variation in side-to-side length symmetry. The purpose of this study was to investigate the side-to-side asymmetry of semitendinosus muscle length in individuals with ACL reconstruction (ACLR) using the semitendinosus/gracilis-graft compared to a group of healthy control subjects to establish the level of retraction that can confidently be ascribed the surgery. Eleven subjects aged 30 (19-39) years, with previous unilateral ACLR with the combined semitendinosus/gracilis tendon graft were recruited. Average follow-up was 6.8years (0.3-13.0) after reconstruction. Ten healthy subjects aged 30years (23-36) with no previous knee surgery served as controls. Bilateral magnetic resonance imaging (MRI) scans were obtained of the thigh from 60mm below the knee joint and 700mm proximal to this point with a slice thickness of 5mm with 5mm inter-slice distance. Semitendinosus length was measured on both legs between the distal and proximal musculotendinous junction of the semitendinosus. Length difference between legs was calculated for all participants. Percentage of shortening was expressed relative to the healthy leg. Subjects who had undergone ACLR had on average 81mm (25%) shortening of the semitendinosus on the reconstructed leg compared to the non-reconstructed side. The healthy subjects all had less than 10mm difference between legs (< 3%). The side-to-side difference was significantly different between the reconstructed patients and the healthy subjects (p < 0.001). This study indicates that retraction larger than 10mm is a consequence of the tendon harvest and not natural variation. It also supports that persistent retraction of the semitendinosus muscle occurs following harvest of the semitendinosus tendon for ACL graft. Level IV.

Characterization of the Proximal Long Head of Biceps Tendon Anatomy Using Magnetic Resonance Imaging: Implications for Biceps Tenodesis

Background: Biceps tenodesis is a common treatment for proximal long head of biceps (LHB) tendon pathology. To maintain biceps strength and contour and minimize cramping, restoration of muscle-length tension and appropriate positioning of the tenodesis is key. Little is known about the biceps musculotendinous junction (MTJ) anatomy, especially in relation to the overlying pectoralis major tendon (PMT), which is a commonly used landmark for tenodesis positioning. Purpose: To characterize the in vivo topographic anatomy of the LHB tendon, in particular the MTJ relative to the PMT, using a novel axial proton-density magnetic resonance imaging (MRI) sequence. Study Design: Descriptive laboratory study. Methods: In total, 45 patients having a shoulder MRI for symptoms unrelated to their biceps tendon or rotator cuff were prospectively recruited. There were 33 men and 12 women, with a mean age of 37 ± 13 years (range, 18-59 years). All patients underwent routine shoulder MRI scans with an additional axial proton density sequence examining the LHB tendon and its MTJ. Three independent observers reviewed each MRI scan, and measurements were obtained for (1) MTJ length, (2) the distance between the proximal MTJ and the superior border of the PMT (MTJ-S), (3) the distance between the distal MTJ to the inferior border of the PMT, and (4) the width of the PMT. Results: The average position of the MTJ-S was 5.9 ± 10.8 mm distal to the superior border of the PMT. The mean MTJ length was 32.5 ± 8.3 mm and the width of the PMT was 28.0 ± 7.3 mm. We found no significant correlation between patient age, height, sex, or body mass index and any of the biceps measurements. We observed wide variability of the MTJ-S position and identified 3 distinct types of biceps MTJ: type 1, MTJ-S above the PMT; type 2, MTJ-S between 0 and 10 mm below the superior border of the PMT; and type 3, MTJ-S >10 mm distal to the superior PMT. Conclusion: In this study, the in vivo anatomy of the LHB tendon is characterized relative to the PMT using a novel MRI sequence. The results demonstrate wide variability in the position of the MTJ relative to the PMT, which can be classified into 3 distinct subtypes or zones relative to the superior border of the PMT. Understanding this potentially allows for accurate and anatomic placement of the biceps tendon for tenodesis. Clinical Relevance: To our knowledge, this is the first study to radiologically analyze the in vivo topographic anatomy of the LHB tendon and its MTJ. The results of this study provide more detailed understanding of the variability of the biceps MTJ, thus allowing for more accurate placement of the biceps tendon during tenodesis.

Musculotendinous Junction Injuries of the Proximal Biceps Femoris: A Prospective Study of 64 Patients Treated Surgically

Background: Injuries to the hamstring complex most commonly involve the proximal musculotendinous junction of the long head of the biceps femoris (MTJ-BFlh). Nonoperative management of these injuries is associated with prolonged rehabilitation and high risk of recurrence. To our knowledge, the surgical management of acute MTJ-BFlh injuries has not been previously reported. Hypothesis: Surgical repair of acute MTJ-BFlh injuries enables return to sporting activity with low risk of recurrence. Study Design: Case series; Level of evidence, 4. Methods: A total of 64 patients (42 male and 22 female) undergoing surgical repair of acute MTJ-BFlh injuries were included. Predefined outcomes were recorded at regular intervals after surgery. Mean follow-up time after surgery was 29.2 months (range, 24.0-37.1 months). Results: All study patients returned to their preinjury levels of sporting activity. Mean ± SD time from surgical intervention to return to sporting activity was 13.4 ± 5.1 weeks. Three patients had reinjury at the operative site: 1 (1.6%) with MTJ-BFlh injury and 2 (3.2%) with myofascial tears. At 3 months after surgery, patients had improved mean passive straight-leg raise (72.0° ± 11.4° vs 24.1° ± 6.8°; P < .001); increased mean isometric hamstring muscle strength at 0° (84.5 % ± 10.4% vs 25.9% ± 8.9%; P < .001), 15° (89.5% ± 7.3% vs 41.2% ± 9.7%; P < .001), and 45° (93.9% ± 5.1% vs 63.4% ± 7.6%; P < .001); higher mean Lower Extremity Functional Scale scores (71.5 ± 5.0 vs 29.8 ± 6.3; P < .001); and improved mean Marx activity rating scores (9.8 ± 2.2 vs 3.8 ± 1.9; P < .001), as compared with preoperative scores. High patient satisfaction and functional outcome scores were maintained at 1 and 2 years after surgery. Conclusion: Surgical repair of acute MTJ-BFlh injuries enables return to preinjury level of sporting function with low risk of recurrence at short-term follow-up.

A Proximal Fibularis Brevis Muscle Is Associated with Longitudinal Split Tendons: A Cadaveric Study

The anomalous distal musculotendinous junction of the fibularis brevis muscle has been hypothesized to contribute to the development of longitudinal fibularis brevis tendon tears. Specifically, the mass effect of the low-lying fibularis brevis muscle belly was thought to increase the pressure on the superior peroneal retinaculum and increase the probability of fibularis brevis tendon subluxation. A more recent examination of the fibularis brevis tendon junction found, contrary to this hypothesis, a statistically significant association between an anomalous proximal musculotendinous junction and the prevalence of longitudinal split tears. However, no rationale was offered. The present study examined the relationship between the musculotendinous junction and the prevalence of longitudinal fibularis brevis tendon tears. A total of 24 fibularis brevis tendon lengths were measured bilaterally in 12 human cadaveric specimens. The tendon lengths were assessed as the vertical distance from the most inferior aspect of the lateral malleolus to the most distal fibularis brevis musculotendinous extension. Only full-thickness tears were identified and included. The lengths of tendons with and without longitudinal tears were compared. Of the 24 tendons examined, 7 (29%) presented with full-thickness longitudinal tears from 4 cadavers (33%). The mean length for the tendons with tears was significantly longer (p < .001) than the mean length of those without tears (28.86 ± 3.02 mm versus 16.29 ± 7.30 mm). Our research concurs with the most recent findings, identifying a statistically significant association between an anomalous proximal muscle belly extension and longitudinal fibularis brevis tendon tears. Furthermore, we propose the hypothesis that a more proximal musculotendinous junction might predispose individuals to a lesser stabilizing effect of the muscle against the posterior lateral surface of the fibula, increasing the probability of anterolateral subluxation, attrition, and longitudinal tear development.

Hamstring injuries in elite Gaelic football: an 8-year investigation to identify injury rates, time-loss patterns and players at increased risk

BackgroundHamstring injuries occur frequently in field sports, yet longitudinal information to guide prevention programmes is missing.AimInvestigate longitudinal hamstring injury rates and associated time loss in elite Gaelic football, while identifying...

Anatomy of the long head of biceps femoris: An ultrasound study.

Hamstring strains, particularly involving the long head of biceps femoris (BFlh) at the proximal musculotendinous junction (MTJ), are commonly experienced by athletes. With the use of diagnostic ultrasound increasing, an in-depth knowledge of normal ultrasonographic anatomy is fundamental to better understanding hamstring strain. The aim of this study was to describe the architecture of BFlh, using ultrasonography, in young men and cadaver specimens. BFlh morphology was examined in 19 healthy male participants (mean age 21.6 years) using ultrasound. Muscle, tendon and MTJ lengths were recorded and architectural parameters assessed at four standardised points along the muscle. Measurement accuracy was validated by ultrasound and dissection of BFlh in six male cadaver lower limbs (mean age 76 years). Intra-rater reliability of architectural parameters was examined for repeat scans, image analysis and dissection measurements. Distally the BFlh muscle had significantly (P < 0.05) shorter fascicles and larger pennation angles than proximal sites. Agreement between ultrasound and dissection (cadaver study) was excellent for all architectural parameters, except pennation angle (PA), and MTJ length. All other measures demonstrated good-excellent repeatability. BFlh is not uniform in architecture when imaged using ultrasound. It is likely that its distal-most segment is better suited for force production in comparison to the more proximal segments, which show excursive potential, traits which possibly contribute to the high rate of injury at the proximal MTJ. The data presented in this study provide specific knowledge of the normal ultrasonographic anatomy of BFlh, which should be of assistance in analysing BFlh injury via imaging. Clin. Anat. 29:738-745, 2016. © 2016 Wiley Periodicals, Inc.

Proximal hamstring morphology and morphometry in men: an anatomic and MRI investigation.

The proximal musculo-tendinous junction (MTJ) is a common site of hamstring strain injury but the anatomy of this region is not well defined. A morphometric analysis of the proximal MTJs of biceps femoris long head (BFlh), semitendinosus (ST), and semimembranosus (SM) was undertaken from dissection of 10 thighs from five male cadavers and magnetic resonance imaging of 20 thighs of10 active young men. The length, volume, and cross-sectional area of the proximal tendon, MTJ and muscle belly, and muscle-tendon interface area were calculated. Inboth groups, MTJs were reconstructed three-dimensionally. The proximal tendons and MTJs were expansive, particularly within SM and BFlh. Morphology varied between muscles although length measurements within individual muscles were similar in cadavers and young men. Semimembranosus had the longest proximal tendon (cadavers: mean 33.6±2.0cm; young men: mean 31.7±1.6cm) and MTJ (>20cm in both groups) and the greatest muscle-tendon interface area, followed by BFlh and ST. Mean muscle belly volumes were more than three times greater in young men than elderly male cadavers (P<0.001). These unique morphometric data contribute to a better understanding of hamstring anatomy, an important factor in the pathogenesis of hamstring strain injury.

Rupture of the conjoint tendon at the proximal musculotendinous junction of the biceps femoris long head: a case report

This case report describes a 20-year-old elite-level Australian Rules football player who suffered three unilateral hamstring injuries within a 2 month period. The first two episodes were managed conservatively. Magnetic resonance imaging following the third episode revealed full thickness disruption of the proximal musculotendinous junction of the biceps femoris long head and semitendinosus muscles and the common proximal (conjoint) tendon. The injury was subsequently surgically repaired. At 16 months following surgery, the player had successfully completed a full competitive season of elite-level Australian Rules football symptom free. Follow-up magnetic resonance imaging demonstrated the repaired tendon to be uniformly hypointense in keeping with reparative granulation tissue formation and restoration of normal muscle morphology. These findings are consistent with an intact repair. The case demonstrates that complete functional and radiological resolution is possible following surgical repair of significant hamstring musculotendinous junction tears.

US evaluation and diagnosis of rupture of the medial head of the gastrocnemius (tennis leg)

Purpose The aim of this study is to demonstrate the diagnostic accuracy of ultrasonography (US) in the diagnosis of rupture of the medial head of the gastrocnemius muscle, also called “tennis leg” (TL). Materials and methods Thirty-five consecutive patients with acute traumatic injury of the calf underwent US examination. There were 25 men and 10 women; mean age 47.5 years (range 35–60 years). All examinations were performed using a 5–12 MHz broadband electronic linear array probe. Results Thirty-three out of 35 patients had TL; 24 cases of partial rupture and nine cases of complete rupture were diagnosed. In the remaining two cases, both with symptoms suggesting TL, one patient had a tear of the proximal musculotendinous junction and one had a ruptured Baker's cyst. Fluid collections caused by the muscular rupture were visible as hypoechoic areas; in 80% of cases associated by a hyperechoic oval area due to hematoma and local inflammation. The degree of fluid collection in the patients with complete rupture (6–16 mm; mean: 9.7 mm) was significantly greater than the one seen in patients with partial rupture (4–8 mm; mean: 6.8 mm). Conclusions US is the imaging modality of choice in clinical suspicion of TL, both in the initial workup of the patient and in the follow-up. US is easy to perform and is particularly useful to distinguish TL from other pathologies, especially ruptured Baker's cyst and deep vein thrombosis, which require a different therapeutic management.

PR_137: Partial Tear of the Biceps Tendon at the Proximal Musculotendinous Junction: A Case Report

Setting: University hospital, outpatient practice. Patient: A 44-year-old public safety officer. Case Description: The patient presented with a chief complaint of left anterior shoulder pain. He described a mechanism of injury that involved resisted left shoulder and arm abduction and extension. Physical examination was subsequently positive for painful active range of motion on left shoulder abduction and flexion, pain on palpation over left bicipital tendon, and ecchymosis in anterior shoulder and arm. Special tests, which included Speed’s, Popeye’s, and apprehension signs, were equivocal. Assessment/Results: Magnetic resonance imaging of the left shoulder was ordered on follow-up for confirmation of a suspected long head of the biceps tendon tear. However, imaging was negative for rotator cuff, bicipital tendon, or labral pathology. Imaging of patient’s left humerus was then obtained, which confirmed an intrasubstance partial tear of the biceps tendon near the proximal musculotendinous junction. The patient returned to full-duty work 2 weeks after initial injury. Discussion: In 96% of cases of biceps tendon injury, the rupture occurs in the long head. 3% of injuries occur in the distal biceps tendon, and 1% in the short head. As this case illustrates, it is often difficult when evaluating proximal biceps tendon lesions to determine the location of the rupture. Of note, this patient quickly returned to his functional baseline with a treatment regimen that involved rest, ice, and oral anti-inflammatory medication. Conclusions: This case illustrates the clinical and radiologic difficulties one encounters when treating atypical biceps muscle and tendon injuries. The treating physician must be aware of the possibility of short head of biceps tendon, coracobrachialis, or musculotendinous junction injuries. A nonoperative and conservative management approach to these injuries is the standard of care. Last, the potential expanded use of musculoskeletal ultrasound in the diagnostic workup for these injuries appears valuable.

Popliteus muscle sesamoid bone (cyamella): appearance on radiographs, CT and MRI

Popliteus muscle sesamoid bone, also known as cyamella, is an accessory ossicle that is located in the vicinity of the proximal musculo tendinous junction. While commonly seen in small mammals such as cats and dogs, its presence in humans is very rare. In this report, we present the radiological findings of the popliteus muscle sesamoid bone, incidentally detected in a 47-year-old male. CT and MRI features of this ossicle are described.

Isolated Rupture of the Plantaris Tendon in a High School Track Athlete

P lantaris muscle or tendon injuries, although rare, have been discussed for over a century. The plantaris is a rudimentary muscle located in the superficial posterior compartment of the leg and varies in its size and development. It originates at the inferior aspect of the lateral supracondylar line of the femur and consists of a small fusiform fleshy muscle belly with a long, slender tendon that crosses obliquely between the gastrocnemius and soleus before inserting into the medial posterior calcaneus, sometimes via the Achilles tendon or occasionally fusing with the flexor retinaculum or leg fascia. Reports of isolated ruptures of the plantaris muscle or tendon are rare, but this is probably related more to misdiagnosis as Achilles tendon pathology, and that they heal quickly, than the paucity of the injury. Plantaris tendon ruptures rarely are isolated, often involving the gastrocnemius or the Achilles tendon. The term coup de fouet, or snap of the whip, was coined in 1597 to describe an Achilles tendon rupture; some authors have used the term, inappropriately, to describe plantaris tendon ruptures. Tennis leg was used to describe plantaris tendon and muscle ruptures, causing more confusion and debate. Few cases of isolated plantaris tendon rupture have been reported. These ruptures occurred at the insertion on the calcaneus or at the proximal musculotendinous junction. To our knowledge, no case has been reported regarding the rupture of the mid-plantaris tendon in isolation, making our patient’s case unique. CASE REPORT A 16-year-old male high school track athlete (6’3’’, 158 lbs) presented to the office complaining of pain in the right Achilles tendon region. He was in his mid-season training, performing modest speed work twice weekly coupled with distance running of roughly 30–40 miles weekly; he performed no plyometric training. On the previous day (weather was sunny, approximately 501F), while performing an afternoon speed workout, he was nearing the end of his fourth 200-meter sprint and felt a ‘‘pop’’ in his right posterior lower-leg region, causing him to fall. He was able to walk, stiffly, afterwards, but incurred mild swelling and pain that evening. The patient denied numbness, tingling, weakness, joint pain, and previous injuries and was otherwise in excellent health, with no allergies and no present or recent medication or supplement use. Standing exam revealed normal foot structure. Strong, equal pulses were palpated bilaterally at his distal lower extremities and capillary refill was less than 2 seconds. No motor or sensory deficits were identified, and excellent plantar

Anatomy of the proximal musculotendinous junction of the adductor longus muscle.

Injuries to the adductor longus commonly occur in the proximal part of the muscle tendon unit, close to the insertion site on the pubic bone. Ultrasonography, magnetic resonance imaging (MRI) and surgery have been helpful in localising the lesions, but the exact anatomy of the musculotendinous junction (MTJ) and insertion of the muscle remain unclear. We studied the anatomical features of the MTJ and measured the dimensions of the tendinous insertion into the pubic bone on 37 cadavers: 18 men and 19 women. The medial boundaries were the longest part of the tendon bilaterally in women, while the lateral aspect of the left muscle was greater in men. Tendinous fibres were predominantly found on the anterior surface, while the posterior surface consisted mainly of muscle tissue. The MTJ was clearly demarcated. There were several types of anomalies present which partially explains the difficulty in localising the site of injury and highlights the importance of individualized treatment.