Good outcome after stripping the plantaris tendon in patients with chronic mid-portion Achilles tendinopathy

Level of Evidence for the Treatment of Chronic Noninsertional Achilles Tendinopathy

BACKGROUND

Noninsertional Achilles tendinopathy affects both athletes and sedentary individuals, and its incidence is rising. Conservative management is the mainstay of treatment, but a variety of operative techniques have been described to treat recalcitrant cases. We seek to outline the current available evidence for surgical management of noninsertional Achilles tendinopathy.

STUDY DESIGN AND METHODS

A systematic review was performed using the MEDLINE and EMBASE databases, and all articles were reviewed by at least 2 authors. Each article was assigned a level of evidence in accordance with the standards of Journal of Bone and Joint Surgery. The available data were reviewed and a level of evidence was assigned to each intervention of interest, based on the revised classifications of Wright.

RESULTS AND CONCLUSION

A total of 46 articles met inclusion and exclusion criteria. There is fair evidence (grade B) in support of open debridement with 1 level II study, 1 level III study, and 8 level IV studies. There is fair evidence (grade B) in support of arthroscopic or minimally invasive surgical techniques. There is poor evidence (grade C) in support of flexor hallucis longus transfer, longitudinal tenotomy, peritenolysis, gastrocnemius recession, and plantaris excision. There is insufficient evidence (grade I) to provide a recommendation about other surgical treatment methods for noninsertional Achilles tendinopathy.Levels of Evidence: Level III: Systematic review.

Combined Midportion Achilles and Plantaris Tendinopathy: A 1-Year Follow-Up Study after Ultrasound and Color-Doppler-Guided WALANT Surgery in a Private Setting in Southern Sweden

Background and Objectives: Chronic painful midportion Achilles combined with plantaris tendinopathy can be a troublesome condition to treat. The objective was to prospectively follow patients subjected to ultrasound (US)- and color doppler (CD)-guided wide awake, local anesthetic, no-tourniquet (WALANT) surgery in a private setting. Material and Methods: Twenty-six Swedish patients (17 men and 9 women, mean age 50 years (range 29–62)) and eight international male patients (mean age of 38 years (range 25–71)) with combined midportion Achilles and plantaris tendinopathy in 45 tendons altogether were included. All patients had had >6 months of pain and had tried non-surgical treatment with eccentric training, without effect. US + CD-guided surgical scraping of the ventral Achilles tendon and plantaris removal under local anesthesia was performed on all patients. A 4–6-week rehabilitation protocol with an immediate full-weight-bearing tendon loading regime was used. The VISA-A score and a study-specific questionnaire evaluating physical activity level and subjective satisfaction with the treatment were used for evaluation. Results: At the 1-year follow-up, 32/34 patients (43 tendons) were satisfied with the treatment result and had returned to their pre-injury Achilles tendon loading activity. There were two dropouts (two tendons). For the Swedish patients, the mean VISA-A score increased from 34 (0–64) before surgery to 93 (61–100) after surgery (p < 0.001). There were two complications, one wound rupture and one superficial skin infection. Conclusions: For patients suffering from painful midportion Achilles tendinopathy and plantaris tendinopathy, US + CD-guided surgical Achilles tendon scraping and plantaris tendon removal showed a high satisfaction rate and good functional results 1 year after surgery.

An atypical case of calf pain: Plantaris tendon axial instability

Plantaris tendon (PT) might induce calf or Achilles pain. In this case report, a 59-year-old woman presented with axial instability of plantaris tendon; post Achilles tendon lengthening. She beneficiated from a needle tenotomy of the PT and had a prompt symptom alleviation. The patient was fully satisfied and had a SANE score of 95% at 12 months follow up and was able to return to moderate sports activities without limitations (hiking, Nordic walking). The instability of the PT might be considered for the differential diagnosis of medial calf pain for which needle tenotomy may be considered a valuable option.

Failed Surgery for Achilles Tendinopathy

Treatments of Achilles tendinopathy continue to evolve. The body of literature is inadequate to provide a comprehensive guide to evaluation and treat failed surgeries. Issues related to failed surgical treatment may be divided into infection/wound issue, mechanical failure, and persistent pain. Awareness of the potential problems described in this article will allow surgeons to have a foundation in clinical assessment and making accurate diagnoses. Various surgical treatment options are available and should be executed carefully to treat individualized patient conditions.

The clinical diagnosis of Achilles tendinopathy: a scoping review

Background

Achilles tendinopathy describes the clinical presentation of pain localised to the Achilles tendon and associated loss of function with tendon loading activities. However, clinicians display differing approaches to the diagnosis of Achilles tendinopathy due to inconsistency in the clinical terminology, an evolving understanding of the pathophysiology, and the lack of consensus on clinical tests which could be considered the gold standard for diagnosing Achilles tendinopathy. The primary aim of this scoping review is to provide a method for clinically diagnosing Achilles tendinopathy that aligns with the nine core health domains.

Methodology

A scoping review was conducted to synthesise available evidence on the clinical diagnosis and clinical outcome measures of Achilles tendinopathy. Extracted data included author, year of publication, participant characteristics, methods for diagnosing Achilles tendinopathy and outcome measures.

Results

A total of 159 articles were included in this scoping review. The most commonly used subjective measure was self-reported location of pain, while additional measures included pain with tendon loading activity, duration of symptoms and tendon stiffness. The most commonly identified objective clinical test for Achilles tendinopathy was tendon palpation (including pain on palpation, localised tendon thickening or localised swelling). Further objective tests used to assess Achilles tendinopathy included tendon pain during loading activities (single-leg heel raises and hopping) and the Royal London Hospital Test and the Painful Arc Sign. The VISA-A questionnaire as the most commonly used outcome measure to monitor Achilles tendinopathy. However, psychological factors (PES, TKS and PCS) and overall quality of life (SF-12, SF-36 and EQ-5D-5L) were less frequently measured.

Conclusions

There is significant variation in the methodology and outcome measures used to diagnose Achilles tendinopathy. A method for diagnosing Achilles tendinopathy is proposed, that includes both results from the scoping review and recent recommendations for reporting results in tendinopathy.

PT4: New arthroscopic technique for isolated reconstruction of the anterior talofibular ligament using a quadrupled plantaris tendon

The strategy for surgical treatment of chronic ankle instability is becoming increasingly refined. In instances of isolated symptomatic non-repairable anterior talofibular ligament (ATFL) injury, there is a surgical indication for isolated ATFL reconstruction. However, we feel that the typical gracilis tendon graft is not always appropriate. Interest in using the plantaris tendon as a graft has picked up since a biomechanics study found the tensile strength of a quadrupled plantaris tendon is comparable to that of the ATFL. Here, we describe an original arthroscopic technique for isolated ATFL reconstruction using a quadrupled plantaris tendon (PT4) graft.

Simultaneous duplication of the tendon of plantaris with multiple tendinous connections into the crural fascia

The plantaris muscle (PM) typically begins with a short, fusiform muscle belly and continues as a slim tendon traversing distally between the gastrocnemius and soleus to attach into the calcaneus directly or Achilles tendon. Conventionally, it has been of most interest as a donor for surgeons plantaris tendon (PT) grafting and recent studies have implicated the PT in the development of Achilles tendinopathy. During routine cadaveric dissection, one such anatomical variation was identified in a cadaver with two distal tendons of the PM and also multiple tendon connections into the crural fascia. While similar variants have been reported before in isolation, to our knowledge, this has been rarely reported illustrating the coexistence of a duplicated PT with simultaneous fascial connections into the crural fascia. The clinical implications of such a finding are discussed.

The plantaris muscle - Anatomical curiosity or a structure with important clinical value? - A comprehensive review of the current literature

PURPOSE

Although the plantaris muscle is vestigial in humans, it is far too important to remain omitted. The aim of this study is to provide a comprehensive review of the existing literature focused on plantaris muscle clinical value, grafting usefulness and its morphological variations. Hopefully this study will be of great use for every medical practitioner due to its clarity and conciseness despite such broaden scope of this article.

MATERIAL AND METHODS

The article is written based on 100 studies published since 1868 until 2020. During careful selection process 12 papers were dismissed due to their insufficient sample size, wrong methods used or results that were previously discovered.

RESULTS

Many aspects concerning the plantaris muscle are already well examined, summarized and described. However this study has shown how much we still do not know and which fields require further investigations.

CONCLUSION

The anatomical variations of plantaris muscle morphology may cause mid-portion Achilles tendinopathy, tennis leg syndrome or increase the risk of failure while harvesting the tendons.

Is the plantaris muscle the most undefined human skeletal muscle?

The plantaris muscle is located in the posterior aspect of the superficial compartment of the lower leg, running from the lateral condyle of the femur to the calcaneal tuberosity. Classically, it is characterized by a small and fusiform muscle belly, which then changes into a long slender tendon. From the evolutionary point of view, the muscle is considered vestigial. However, it has recently been suspected of being a highly specialized sensory muscle because of its high density of muscle spindles. It has a noticeable tendency to vary in respect of both origin and insertion. Researchers have published many reports on the potential clinical significance of the muscle belly and tendon, including mid-portion Achilles tendinopathy, ‘tennis leg syndrome’, and popliteal artery entrapment syndrome. The right knee joint area was subjected to classical anatomical dissection, during which an atypical plantaris muscle was found and examined in detail. Accurate morphometric measurements were made. The muscle belly was assessed as bifurcated. Morphologically, superior and inferior parts were presented. There was a tendinous connection (named band A) with the iliotibial tract and an additional insertion (named band B) to the semimembranosus tendon. Both bands A and B presented very broad fan-shaped attachments. The human plantaris muscle is of considerable interest and has frequent morphological variations in its proximal part. Its specific characteristics can cause clinical problems and lead to confusion in diagnosis. More studies are needed to define its actual features and functions.

Achilles Tendon Lesions - Part 1: Tendinopathies

Calcaneal tendon injuries are extremely common in the general population and in orthopedics routine care. Its increasing incidence, which is motivated by an aging population, improved access to the health care system, increased prescription of continuous-use medication, erratic participation in sports and other factors, has had a direct impact on society. Consolidated treatment options for tendinopathies lack quality scientific support for many modalities. New therapies have emerged to enhance nonsurgical approach outcomes and to reduce the number of patients requiring surgery. Although these operative procedures provide good pain relief and functional outcomes, they are costly and may lead to complications.

Possible effect of morphological variations of plantaris muscle tendon on harvesting at reconstruction surgery-case report

Purpose

Seemingly a well-known, weak, and vestigial plantaris muscle should not be a revelation. However, recent studies have shown that this structure is incredibly underestimated and perceived only as an infirm flexor of the talocrural joint, the knee joint or a great source of graft tissue. Usually, the origin of this inconspicuous muscle begins at the lateral supracondylar line of the femur and the knee joint capsule. It continues distally, forming a long and slender tendon. In most cases, it inserts onto the calcaneal tuberosity on the medial side of the Achilles tendon. However, many morphological variations have been discovered during anatomical dissections and surgical procedures. Nevertheless, according to the present literature, no other studies presented such a complex insertion variant, with indisputable clinical value and significant proof of development of this forgotten muscle.

Methods

The dissection of the right thigh, knee, crural and talocrural region was performed using standard techniques according to a strictly specified protocol.

Results

Four different insertion points were observed. The first band (A) inserted near to the tarsal canal flexor retinaculum. The second band (B) bifurcates into two branches—B1 and B2. B1 is located on the medial side and B2 is located on the lateral side of the calcaneal tuberosity. The third band (C) is inserted into the superior nonarticular calcaneal surface of the calcaneus anteriorly to the Achilles tendon.

Conclusion

A differently shaped plantaris tendon could be considered a cause of harvesting procedure failure. In the light of new case reports perhaps what we are now witnessing is remodeling and transformation of the Plantaris muscle. If so, the awareness of the influence on the onset of Achilles midportion tendinopathy or a potential role in tibialis posterior conflict can be crucial for every clinician.

A highly complex variant of the plantaris tendon insertion and its potential clinical relevance

The body is home to a number of unique and intriguing anatomical structures, plenty of which concern the muscles and their tendons. Of these, the plantaris muscle is reported to present a particularly high range of morphological variations. The muscle, passing distally throughout the length of the lower leg, consists of a small muscle belly and a long, thin tendon. It originates, traditionally, on the popliteal surface of the femur and the knee joint capsule, and then inserts to the calcaneal tuberosity. It has been suggested that mid-portion Achilles tendinopathy may be caused by certain plantaris tendon morphologies. This case report describes a new anomalous plantaris tendon insertion, closely related to the Achilles tendon. It comprise four distinct insertions and one direct merge with the calcaneal tendon. The current classification should be extended to accommodate such ‘rare cases’ to facilitate more successful Achilles tendinopathy treatment.

Proposal for a new classification of plantaris muscle origin and its potential effect on the knee joint

PURPOSE

The plantaris muscle (PM) is typically characterized by a short, slim and spindle-shaped muscle belly and long, thin tendon. It is situated posterior to the popliteal muscle, and anterior to the lateral head of the gastrocnemius muscle (GM). Little information exists regarding the high variability of origin of the PM. The main aim of the study was hence to characterize the morphology of the PM and its place of origin, classify it and evaluate its prevalence.

METHODS

Classical anatomical dissection was performed on 142 lower limbs (77 left, and 65 right) fixed in 10% formalin solution. The morphology of the origin of the PM and its prevalence was evaluated.

RESULTS

The PM was present in 128 lower limbs (90.1%). Six types of origin were observed, the most common being Type I (48.4%). This type was divided into two subtypes (A-B): subtype A attaching to the lateral head of the GM, lateral femoral condyle and to the capsule of the knee joint, and subtype B, attaching to the lateral head of the GM, the lateral femoral condyle, knee joint capsule and the popliteal surface of the femur. The second most common type was Type II (25%), attaching to the capsule of the knee joint and, indirectly, to the lateral head of the GM through the lateral femoral condyle. The third most common type was Type III (10.15%), attaching to the lateral femoral condyle and the knee joint capsule. Type IV (6.25%), the rarest type, attached to the lateral femoral condyle, knee joint capsule and to the iliotibial band. Type V (8.6%) originated only from the lateral condyle of the femur. Type VI (1.6%) contains only "rare cases".

CONCLUSION

The PM presents high morphological variability, and its status as a residual muscle should be reconsidered. Our presented classification of its types of origin is a valuable addition for both clinicians and anatomists. Level of Evidence - II Basic Science Research.

Treatment of Acute Achilles Tendon Rupture

There is no clear consensus on the optimal treatment of acute Achilles tendon rupture. Recently, studies have demonstrated the critical role of functional rehabilitation in the treatment of ruptured Achilles tendons. Hence, conservative treatment is preferred by a growing number of surgeons seeking to treat the condition without the risk of complications from surgery. However, operative treatment is still considered as a more reliable treatment option for acute Achilles tendon rupture. In this review article, we provide an overview of recent treatment strategies for acute rupture of the Achilles tendon.

It is possible to release the plantaris tendon under ultrasound guidance: a technical description of ultrasound guided plantaris tendon release (UPTR) in the treatment of non-insertional Achilles tendinopathy

PURPOSE

Open plantaris tendon excision and ventral paratendinous stripping is a recognised treatment option in selected patients with non-insertional Achilles tendinopathy. The aim of this study was to develop a minimally invasive outpatient technique of ultrasound guided plantaris tendon release (UPTR).

METHODS

A 19 gauge needle, 15 gauge scalpel blade, hook knife (Smith and Nephew, Boston, MA, USA) and a beaver blade (Arthrex, Naples, FL, USA), were used under ultrasound guidance to identify and divide the plantaris tendon in 12 cadaveric legs. Specimens were dissected to identify whether division of the plantaris tendon had been successful. UPTR was subsequently performed on patients.

RESULTS

The 15 gauge scalpel blade, hook knife (Smith and Nephew, Boston, MA, USA) and beaver blade (Arthrex, Naples, FL, USA) were all able to cut the plantaris tendon. However, on dissection the hook knife (Smith and Nephew, Boston MA) caused less damage to surrounding structures. Subsequently, the plantaris tendon was successfully divided in three patients using UPTR technique without complication.

CONCLUSION

UPTR is a viable technique for treating plantaris related non-insertional Achilles tendinopathy.

Minimally Invasive and Endoscopic Approach for the Treatment of Noninsertional Achilles Tendinopathy

Minimally invasive treatment can offer an earlier recovery with less pain and scarring compared with traditional open surgeries. The goals of minimally invasive surgery are to debride degenerative tendon, stimulate healing, and, when appropriate, repair damaged tendon. Sclerotherapy and prolotherapy have been shown to reduce neovascularization and pain. Percutaneous stripping and endoscopic debridement are better options for diffuse tendinopathy. Plantaris release can be useful in diffuse disease in patients with primarily medial-sided Achilles pain. Overall, minimally invasive surgery provides similar benefits as open procedures with reduced complications and morbidity.

Prevalence of Coexistent Plantaris Tendon Pathology in Patients with Mid-Portion Achilles Pathology: A Retrospective MRI Study

Co-existence of Plantaris tendinopathy (PT) in patients with mid-Achilles tendinopathy (Mid-AT) is of clinical significance. This study aims to describe the MRI-based pathological characteristics of co-existing PT and Mid-AT. One-hundred MRI studies of patients diagnosed with Mid-AT were retrospectively analysed by an experienced musculoskeletal radiologist. Presence or absence of a Plantaris tendon, co-existing PT with Mid-AT, insertional characteristics of Plantaris tendon, and maximum anteroposterior thickness of the tendon in Mid-AT (axial images) were evaluated. When PT co-existed with Mid-AT, the location of the tendon pathologies in relation to calcaneal insertion was assessed (sagittal images) and their association was analysed using the coefficient of variation (CV) and Pearson’s correlation coefficient. Plantaris was present in 84 cases (84%), and Mid-AT and PT co-existed in 10 cases (10%). A greater variability in the location of Plantaris pathology (CV = 42%) than Achilles tendinopathy (CV = 42%) was observed. The correlation coefficient also revealed a low and non-significant association between the location of two pathologies when they exist together (r = +0.06; p = 0.88). Clinical evaluation of Achilles tendon pain needs careful consideration into the possible co-existence of Plantaris pathology. The considerable difference observed in the location of PT and Mid-AT suggest possible isolated pathologies and differentials for Achilles tendon pain.

Comparative multi-scale hierarchical structure of the tail, plantaris, and Achilles tendons in the rat

Rodent tendons are widely used to study human pathologies such as tendinopathy and repair, and to address fundamental physiological questions about development, growth, and remodeling. However, how the gross morphology and multi-scale hierarchical structure of rat tendons, such as the tail, plantaris, and Achilles tendons, compare with that of human tendons are unknown. In addition, there remains disagreement about terminology and definitions. Specifically, the definitions of fascicle and fiber are often dependent on diameter sizes, not their characteristic features, and these definitions impair the ability to compare hierarchical structure across species, where the sizes of the fiber and fascicle may change with animal size and tendon function. Thus, the objective of the study was to select a single species that is commonly used for tendon research (rat) and tendons with varying mechanical functions (tail, plantaris, Achilles) to evaluate the hierarchical structure at multiple length scales using histology, SEM, and confocal imaging. With the exception of the specialized rat tail tendon, we confirmed that in rat tendons there are no fascicles and the fiber is the largest subunit. In addition, we provided a structurally based definition of a fiber as a bundle of collagen fibrils that is surrounded by elongated cells, and this definition was supported by both histologically processed and unprocessed samples. In all rat tendons studied, the fiber diameters were consistently between 10 and 50 μm, and this diameter range appears to be conserved across larger species. Specific recommendations were made highlighting the strengths and limitations of each rat tendon as a research model. Understanding the hierarchical structure of tendon can advance the design and interpretation of experiments and development of tissue-engineered constructs.

Results of minimally invasive Achilles tendon scraping and plantaris tendon removal in patients with chronic midportion Achilles tendinopathy: A longer-term follow-up study

Background:

Treatment with ultrasound and colour Doppler–guided minimally invasive Achilles tendon scraping and plantaris tendon removal has shown promising short-term results in patients with chronic painful midportion Achilles tendinopathy.

Methods:

In a follow-up study, 182 consecutive patients (241 tendons) who had undergone Achilles tendon scraping and plantaris tendon removal were contacted on telephone by an independent investigator. The patients who answered the telephone call were included, and they answered a questionnaire on telephone and then also sent their written answers. The questionnaire included information about patient satisfaction with the result of the treatment, time to return to full Achilles tendon loading activity, and a pain score (Visual Analogue Scale-VAS).

Results:

The follow-up period was 5.8 years (mean) (range of 2–13 years) after surgery. Altogether, 110 patients (136 Achilles tendons), 52 years (mean)(range 18-73) old at surgery could be reached and were included. In total, 81 tendons were operated with the Achilles scraping procedure alone, and for 55 Achilles operations also a plantaris tendon removal was performed. For 93% of the operated tendons, the patients were satisfied with the surgical outcome and the VAS had decreased from 74 preoperatively to 8 postoperatively. Nine male patients (9 tendons), five operated with scraping + plantaris removal, had remaining tendon pain during loading and were not satisfied. Their VAS score ranged from 22 to 91. For 21% of the operated tendons, some occasional mild discomfort not preventing from full tendon loading, was reported. There were no differences in pain reduction and satisfaction rates between men and women, and between Achilles scraping alone and scraping plus plantaris removal.

Conclusion:

Ultrasound and colour Doppler–guided surgical Achilles tendon scraping and plantaris tendon removal in patients with chronic painful midportion Achilles tendinopathy show remaining good clinical outcomes and high satisfaction rates in this longer-term follow-up.

Sonographically Guided Plantaris Tendon Release: A Cadaveric Validation Study

BACKGROUND

The plantaris tendon (PT) has been implicated in the pathogenesis of symptoms in a subset of patients with Achilles region pain syndromes and traditionally has been managed via open surgical resection. Although the PT can be visualized on ultrasound, a minimally invasive technique for sonographically guided PT release has not been formally described.

OBJECTIVE

To validate a technique to perform sonographically guided PT release in an unembalmed cadaveric model.

DESIGN

Prospective, cadaveric laboratory investigation.

SETTING

Procedural skills laboratory in a tertiary medical center.

SUBJECTS

Twenty unembalmed cadaveric knee-ankle-foot specimens (10 right, 10 left) obtained from 16 donors (6 male, 10 female) ages 55-96 years (mean 82.6 years) with body mass indexes of 14.1-33.2 kg/m² (mean 23.3 kg/m² ).

METHODS

After simulated local anesthesia and sonographically guided hydrodissection of the plantaris tendon-Achilles tendon interval, a single experienced operator performed sonographically guided PT release on each specimen using an in-plane, lateral-to-medial approach, a commercially available, disposable 3.0-mm hook knife, and either a 17-5 MHz or 15-7 MHz linear array transducer. Each specimen was subsequently dissected to assess for PT release and iatrogenic injury.

MAIN OUTCOME

Status of the PT, Achilles tendon, and regional neurovascular structures as determined by dissection.

RESULTS

All 20 PT releases were completed in a single attempt through a 3- to 5-mm incision. Dissection confirmed complete PT release in all specimens without damage to the adjacent Achilles tendon or regional neurovascular structures.

CONCLUSION

Sonographically guided PT release is technically feasible and can be performed while avoiding injury to the Achilles tendon and regional neurovascular structures. Additional research is warranted to further define the role of sonographically guided PT release in patients with suspected PT-mediated Achilles region pain syndromes.

LEVEL OF EVIDENCE

IV.

Percutaneous Electrochemical Debridement of the Plantaris Tendon

Plantaris tendon disorders are a well-known source of midportion Achilles tendinopathy. Plantaris tendon thickening and fibrous tissue formation between the tendons are the histologic abnormalities that are typically observed. Surgical approaches (scraping of the Achilles medial and ventral paratendinous tissues and excision of the plantaris tendon) have already shown good clinical outcomes; despite this, the cost-benefit ratio of these interventions may be unfavorable, and their accessibility is limited. Percutaneous needle electrolysis is a minimally invasive ablative technique increasingly being considered for the treatment of tendinopathies and associated conditions. Herein we introduce a novel procedure to treat plantaris tendon-related midportion Achilles tendinopathy. The procedure starts with the ultrasound-guided insertion of an uncoated needle (diameter, 0.30-0.40 mm; length, 30 mm) between the plantaris and Achilles tendons. Subsequently, galvanic current (intensity, 2 mA) is locally transferred, which induces instant nonthermal electrochemical ablation of the intertendinous tissues in close proximity to the needle, finally debriding the plantaris tendon. To further promote its release, the second part of the procedure involves partial tenotomy of the lateral peripheral aspects of the plantaris tendon. Usually, the session does not exceed 30 min. Percutaneous needle electrolysis may be considered as a valid alternative to surgery. The outpatient procedure presented herein is, in fact, safe and quick to perform. In addition, long suspension of working or sporting activities after treatment is not required. Future investigations are needed to ascertain the short- and long-term therapeutic outcomes of plantaris tendon-related midportion Achilles tendinopathy treatment, in particular by comparing them with those obtained with other mini-invasive interventions.

Peritenolysis and Debridement for Main Body (Mid-Portion) Achilles Tendinopathy in Athletic Patients: Results of 107 Procedures

Achilles tendinopathy in the main body (mid-portion) of the tendon is a common pathologic finding among active and athletic populations and can be debilitating without proper and adequate treatment. Numerous surgical approaches for this common pathologic finding have been reported, with variable outcomes. We evaluated the surgical outcomes of peritenolysis and debridement of main body Achilles tendinopathy among athletic populations using the return to activity (RTA) and decreased desired activity (DDA) as our primary outcome measures. A total of 100 patients underwent 107 procedures by the senior author (A.S.) from January 2001 through December 2015 met the inclusion criteria, 65 (65%) of whom were runners. The mean follow-up duration was 106.6 ± 55.5 months from the index procedure, and the mean interval necessary to RTA for the entire group was 10.9 ± 5.3 weeks. The average RTA after debridement was 14.1 ± 5.2 weeks and after peritenolysis was 7.3 ± 2.0 weeks (p = .00001). Of the 100 patients, 3 (3%) had experienced a DDA at the last follow-up visit. With >97% of the patients able to return to their desired activities, we have concluded that peritenolysis and debridement are favorable surgical techniques for main body Achilles tendinopathy.

The Plantaris Muscle Tendon and Its Relationship with the Achilles Tendinopathy

Purpose

Although the plantaris muscle (PM) is vestigial in humans, it has a significant clinical role in procedures such as grafting. However, recent reports suggest its potential involvement in the tendinopathy of the midportion of the Achilles tendon. The aim of the study is therefore to evaluate morphological variation of the PM with regard to its potential conflict with the Achilles tendon.

Material and Methods

Classical anatomical dissection was performed on 130 lower limbs (71 right, 59 left) fixed in 10% formalin solution. The morphology of the PM was assessed regarding the relationship between the course of the plantaris tendon and the calcaneal tendon.

Results

The PM was present in 89.2% of cases. The findings indicate the presence of a new type of PM tendon insertion in which the tendon is inserted into the tarsal canal flexor retinaculum, potentially affecting the tendinopathy of the tibialis posterior muscle. In 26 cases (22.4%), insertion blended with the Achilles tendon (Type II), which may increase the risk of Achilles tendinopathy.

Conclusion

The anatomical variation of PM tendon morphology may create a potential conflict with the Achilles tendon and the tibialis posterior tendon, thus increasing the possibility of tendinopathy.

Differential Motion and Compression Between the Plantaris and Achilles Tendons: A Contributing Factor to Midportion Achilles Tendinopathy?

BACKGROUND

The plantaris tendon (PT) has been thought to contribute to symptoms in a proportion of patients with Achilles midportion tendinopathy, with symptoms improving after PT excision.

HYPOTHESIS

There is compression and differential movement between the PT and Achilles tendon (AT) during ankle plantarflexion and dorsiflexion.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Eighteen fresh-frozen cadaveric ankles (mean ± SD age: 35 ± 7 years, range = 27-48 years; men, n = 9) were mounted in a customized testing rig, where the tibia was fixed but the forefoot could be moved freely. A Steinmann pin was drilled through the calcaneus, enabling a valgus torque to be applied. The soleus, gastrocnemius, and plantaris muscles were loaded with 63 N with a weighted pulley system. The test area was 40 to 80 mm above the os calcis, corresponding to where the injury is observed clinically. Medially, the AT and PT were exposed, and a calibrated flexible pressure sensor was inserted between the tendons. Pressure readings were recorded with the ankle in full dorsiflexion, full plantarflexion, and plantargrade and repeated in these positions with a 5 N·m torque, simulating increased hindfoot valgus. The pressure sensor was removed and the PT and AT marked with ink at the same level, with the foot held in neutral rotation and plantargrade. Videos and photographs were taken to assess differential motion between the tendons. After testing, specimens were dissected to identify the PT insertion. One-way analysis of variance and paired t tests were performed to make comparisons.

RESULTS

The PT tendons with an insertion separate from the AT demonstrated greater differential motion through range (14 ± 4 mm) when compared with those directly adherent to the AT (2 ± 2 mm) ( P < .001). Mean pressure between the PT and AT rose in terminal plantarflexion for all specimens ( P < .001) and was more pronounced with hindfoot valgus ( P < .001).

CONCLUSION

The PT inserting directly into the calcaneus resulted in significantly greater differential motion as compared with the AT. Tendon compression was elevated in terminal plantarflexion, suggesting that adapting rehabilitation tendon-loading programs to avoid this position may be beneficial.

CLINICAL RELEVANCE

The insertion pattern of the PT may be a factor in plantaris-related midportion Achilles tendinopathy. Terminal range plantarflexion and hindfoot valgus both increased AT and PT compression, suggesting that these should be avoided in this patient population.

Noninsertional Tendinopathy of the Achilles

Noninsertional Achilles tendinosis is differentiated from insertional Achilles tendinosis based on anatomic location. Tendinosis, as opposed to tendonitis, is primarily a degenerative process and the role of inflammation is believed limited. The etiology of Achilles tendinopathy may include overuse leading to repetitive microtrauma, poor vascularity of the tissue, mechanical imbalances of the extremity, or combination of these elements. There is evidence to support eccentric exercise nonoperative management for patients with noninsertional Achilles tendinopathy. Operative treatment options include percutaneous longitudinal tenotomies, minimally invasive tendon scraping, open débridement and tubularization, and tendon augmentation with flexor hallucis longus.

The plantaris tendon: a narrative review focusing on anatomical features and clinical importance

In recent years, the plantaris tendon has been implicated in the development of chronic painful mid-portion Achilles tendinopathy. In some cases, a thickened plantaris tendon is closely associated with the Achilles tendon, and surgical excision of the plantaris tendon has been reported to be curative in patients who have not derived benefit following conservative treatment and surgical interventions. The aim of this review is to outline the basic aspects of, and the recent research findings, related to the plantaris tendon, covering anatomical and clinical studies including those dealing with histology, imaging and treatment. Cite this article: Bone Joint J 2016;98-B:1312-19.

Plantaris Excision Reduces Pain in Midportion Achilles Tendinopathy Even in the Absence of Plantaris Tendinosis

Background:

It is becoming increasingly apparent that the plantaris can contribute to symptoms in at least a subset of patients with midportion Achilles tendinopathy. However, the nature of its involvement remains unclear.

Purpose:

To determine whether excised plantaris tendons from patients with midportion Achilles tendinopathy display tendinopathic changes and whether the presence of such changes affect clinical outcomes.

Study Design:

Case series; Level of evidence, 4.

Methods:

Sixteen plantaris tendons in patients with midportion Achilles tendinopathy recalcitrant to conservative management underwent histological examination for the presence of tendinopathic changes. All patients had imaging to confirm the presence of the plantaris tendon adherent to or invaginated into the focal area of Achilles tendinosis. Visual analog scale (VAS) and Foot and Ankle Outcome Score (FAOS) results were recorded pre- and postoperatively.

Results:

Sixteen patients (mean age, 26.2 years; range, 18-47 years) underwent surgery, with a mean follow-up of 14 months (range, 6-20 months). The plantaris tendon was histologically normal in 13 of 16 cases (81%). Inflammatory changes in the loose peritendinous connective tissue surrounding the plantaris tendon were evident in all cases. There was significant improvement in mean VAS scores (P < .05) and all domains of the FAOS postoperatively (P < .05).

Conclusion:

The absence of any tendinopathic changes in the excised plantaris of 13 patients who clinically improved suggests plantaris involvement with Achilles tendinopathy may not yet be fully understood and supports the concept that this may be a compressive or a frictional phenomenon rather than purely tendinopathic.

Differential Plantaris-Achilles Tendon Motion: A Sonographic and Cadaveric Investigation

BACKGROUND

Differential motion between the plantaris and Achilles tendons has been hypothesized to contribute to pain in some patients presenting with Achilles tendinopathy. However, objective evidence of differential Achilles-plantaris motion is currently lacking from the literature.

OBJECTIVE

To determine whether differential, multidirectional motion exists between the plantaris tendon (PT) and Achilles tendon (AT) as documented by dynamic ultrasound (US) and postdissection examination in an unembalmed cadaveric model.

DESIGN

Prospective, cadaveric laboratory investigation.

SETTING

Procedural skills laboratory in a tertiary medical center.

SUBJECTS

Twenty unembalmed knee-ankle-foot specimens (9 right, 11 left) obtained from 6 male and 10 female donors ages 55-96 years (mean 80 years) with body mass indices of 14.1-33.2 kg/m² (mean 22.5 kg/m²).

METHODS

A single, experienced operator used high-resolution dynamic US to qualitatively document differential PT-AT motion during passive ankle dorsiflexion-plantarflexion. Specimens were then dissected and passive dorsiflexion-plantarflexion was repeated while differential PT-AT motion was visualized directly.

MAIN OUTCOME MEASUREMENTS

Presence or absence of multidirectional differential PT-AT motion.

RESULTS

All 20 specimens exhibited smooth but variable amplitude multidirectional differential PT-AT motion. Whereas US readily demonstrated medial-lateral and anterior-posterior PT motion relative to the AT, differential longitudinal motion was only appreciated on dissection and direct inspection. Many specimens exhibited partial or complete encasement of the PT between the gastrocnemius portion of the AT and the soleus aponeurosis.

CONCLUSION

Some degree of multidirectional differential PT-AT motion appears to be a normal phenomenon, and PT motion can be evaluated sonographically in both the medial-lateral and anterior-posterior directions. The existence of normal differential PT-AT motion suggests that alterations in PT motion or repetitive stress within the PT-AT interval may produce symptoms in some patients presenting with Achilles region pain syndromes. The PT should be evaluated in all patients presenting with Achilles, plantaris, or calf pain syndromes. Future research would benefit from the development of a sonographic classification system for PT anatomy and motion with the goal of differentiating normal versus pathologic states and identifying risk factors for symptom development.

LEVEL OF EVIDENCE

IV.

Treatment of midportion Achilles tendinopathy: an evidence-based overview

In Achilles tendinopathy, differentiation should be made between paratendinopathy, insertional- and midportion Achilles tendinopathy. Midportion Achilles tendinopathy is clinically characterized by a combination of pain and swelling at the affected site, with impaired performance as an important consequence. The treatment of midportion Achilles tendinopathy contains both non-surgical and surgical options. Eccentric exercise has shown to be an effective treatment modality. Promising results are demonstrated for extracorporeal shockwave therapy. In terms of the surgical treatment of midportion Achilles tendinopathy, no definite recommendations can be made.

LEVEL OF EVIDENCE

IV.

Plantaris injuries in elite UK track and field athletes over a 4-year period: a retrospective cohort study

PURPOSE

The plantaris tendon is present in 98-100 % of people, and a potential relationship between the plantaris tendon and the development of Achilles tendinopathy has been postulated. There are no studies on the epidemiology of plantaris injuries in a sporting population. This retrospective cohort study presents the incidence, nature and outcome of plantaris injuries in elite British track and field athletes.

METHOD

All 214 elite athletes supported by the British Athletics Medical team from 2009 to 2013 were included in this cohort study. An injury was recorded if a plantaris injury was diagnosed and confirmed with imaging or surgical findings. Patient demographics, injury details and return to competitive elite track and field were recorded.

RESULTS

There were 33 new plantaris injuries, with an annual plantaris injury incidence of 3.9-9.3 %. There were significantly more right-sided plantaris injuries in bend running sprinters (15 right-sided vs. 4 left-sided). 74 % of the athletes who had a plantaris injury also had Achilles tendinopathy at some point during the study period. Seventeen plantaris tendons were surgically removed from 13 athletes during the course of the study with 12 of the 13 athletes returning to the same level on the Tegner activity scale.

CONCLUSION

This retrospective cohort study demonstrates that plantaris injuries are common in elite track and field athletes and may be underreported in the literature. There may be an association between the biomechanics bend sprinting and plantaris injury. Elite athletes may benefit from appropriate preventative and management strategies implemented by coaching and medical teams.

LEVEL OF EVIDENCE

IV.

Anatomic study suggests that the morphology of the plantaris tendon may be related to Achilles tendonitis

Purpose

Achilles tendinopathy is a significant clinical lower limb issue observed in recent years. Neither the location nor the mechanism behind the pain has yet been sufficiently explained. Patients frequently experience pain on the medial side of the calcaneal tendon, and between 2 and 7 cm above the calcaneal tuberosity, which may suggests that the plantaris tendon plays an important role. The purpose of this study was to determine the anatomical relationships between the course of the plantaris tendon and the calcaneal tendon, as well as the type of insertion of the plantaris tendon.

Methods

The tests were carried out on 50 randomized lower limbs (23 left and 27 right) fixed in 10 % formalin solution.

Results

Five insertion types of the plantaris tendon were identified in relation to the calcaneal tendon: four with their insertion on the calcaneal tuberosity (Types 1, 2, 3, 5), while the fifth (Type 4) had its insertion in the crural fascia. In addition, two variants of the course of the plantaris tendon were identified, the most common being termed Variant A, in which the tendon crosses the space between the gastrocnemius and the soleus muscles, thus reaching the medial crural region, and is located on the medial side of the calcaneal tendon (84 % cases). The course of the Variant B is similar to the course of the Variant A, but upon leaving the space located between the gastrocnemius and soleus muscle, it turned to the medial crural region and ran directly anterior to the calcaneal tendon (12 %). The plantaris muscle was found to be absent in two lower limbs (4 %). The most frequent insertion type of the plantaris tendon into the calcaneal tuberosity is fan-shaped, occurring on the medial side of the Achilles tendon (Type 1–44 % cases).

Conclusion

The course of the plantaris tendon and its mobility range in relation to the calcaneal tendon may be likely to affect the occurrence of pains in the lower medial part of the leg (Achilles tendinopathy).

Plantaris Excision and Ventral Paratendinous Scraping for Achilles Tendinopathy in an Athletic Population

BACKGROUND

Achilles tendinopathy is a frequent problem in high-level athletes. Recent research has proposed a combined etiologic role for the plantaris tendon and neovascularization. Both pathologies can be observed on ultrasound imaging.(1,13) However, little is known about the change in structure of the Achilles tendon following the surgical treatment of these issues. The purpose of the study was to assess if excising the plantaris and performing ventral paratendinous "scraping" of the neovascularization improved symptoms of Achilles tendinopathy and whether there was a change in the fibrillar structure of the tendon with ultrasound tissue characterization (UTC) following this operation.

METHODS

This prospective consecutive case series included 15 professional/semiprofessional athletes (17 Achilles tendons) who underwent plantaris excision and paratendinous scraping to treat noninsertional Achilles tendinopathy. The plantaris tendon was excised if adherent to the Achilles tendon, and the area of neovascularization for scraping was demarcated on preoperative imaging. Preoperative and postoperative Victorian Institute of Sports Assessment-Achilles (VISA-A) scores were taken. UTC was performed on 11 of 17 tendons preoperatively and postoperatively. The mean follow-up was for 25 months.

RESULTS

Fourteen of 15 patients had a successful outcome after the surgery. The mean VISA-A improved from 51 to 95 (p=.0001). There was a statistically significant (p=.04) improvement in the aligned fibrillar structure of the tendon confirmed with UTC scanning following surgery from 90% (±8) to 96% (±5).

CONCLUSION

This group of high-level athletes derived an excellent clinical result from this operation. Furthermore, UTC scanning offered an objective method to evaluate the healing of Achilles tendons.

LEVEL OF EVIDENCE

Level IV, case series.

Analysing the outcome of surgery for chronic Achilles tendinopathy over the last 50 years

AIM

To determine an association between when the study was performed, the robustness of the study and the outcomes for insertional and non-insertional Achilles tendinopathy surgery.

METHODS

We performed a systematic review in accordance with the PRISMA guidelines to assess the methodology of studies investigating the outcome of surgery in chronic Achilles tendinopathy over the last 50 years to identify any trends that would account for the variable results. The Coleman Methodology Scores were correlated with the reported percentage success rates and with the publication year to determine any trends using Pearson's correlation.

RESULTS

We identified 62 studies published between 1964 and 2014 reporting on a total of 2923 surgically treated Achilles tendinopathies. The average follow-up time was 40 mo (range 5-204 mo), and the mean reported success rate was 83.5% (range 36%-100%). The Coleman Methodology Scores were highly reproducible (r = 0.99, P < 0.01), with a mean of 40.1 (SD 18.9, range 2-79). We found a negative correlation between reported success rate and overall methodology scores (r = -0.40, P < 0.001), and a positive correlation between year of publication and overall methodology scores (r = 0.46, P < 0.001).

CONCLUSION

We conclude that although the success rate of surgery for chronic Acilles tendinopathy described in the literature has fallen over the last 50 years, this is probably due to a more rigorous methodology of the studies.