Re: 햄스트링 tendon --＞ sciatic nerve 포착, 초음파 진단 및 치료...

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Muscles Ligaments Tendons J

. 2016 Sep 17;6(2):248–252. doi: 10.11138/mltj/2016.6.2.248

Treatment of proximal hamstring tendinopathy-related sciatic nerve entrapment: presentation of an ultrasound-guided “Intratissue Percutaneous Electrolysis” application

Gabriele Mattiussi 1, Carlos Moreno 1,✉

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PMCID: PMC5115258  PMID: 27900300

SummaryBackground

Proximal Hamstring Tendinopathy-related Sciatic Nerve Entrapment (PHTrSNE) is a neuropathy caused by fibrosis interposed between the semimembranosus tendon and the sciatic nerve, at the level of the ischial tuberosity.

Methods

Ultrasound-guided Intratissue Percutaneous Electrolysis (US-guided EPI) involves galvanic current transfer within the treatment target tissue (fibrosis) via a needle 0.30 to 0.33 mm in diameter. The galvanic current in a saline solution instantly develops the chemical process of electrolysis, which in turn induces electrochemical ablation of fibrosis. In this article, the interventional procedure is presented in detail, and both the strengths and limits of the technique are discussed.

Results

US-guided EPI eliminates the fibrotic accumulation that causes PHTrSNE, without the semimembranosus tendon or the sciatic nerve being directly involved during the procedure. The technique is however of limited use in cases of compression neuropathy.

Conclusion

US-guided EPI is a technique that is quick to perform, minimally invasive and does not force the patient to suspend their activities (work or sports) to make the treatment effective. This, coupled to the fact that the technique is generally well-tolerated by patients, supports use of US-guided EPI in the treatment of PHTrSNE.

요약 배경

근위 햄스트링 건염 관련 좌골신경 압박(PHTrSNE)은 

좌골 결절 부위의 반막근 힘줄과 좌골신경 사이에 

섬유증이 끼어 발생하는 신경병증입니다.

방법
초음파 유도 조직 내 경피적 전기분해(Ultrasound-guided Intratissue Percutaneous Electrolysis, US-guided EPI)는 

직경 0.30~0.33mm의 바늘을 통해 

치료 대상 조직(섬유증) 내에서 갈바닉 전류를 전달하는 방법입니다. 

식염수 용액의 갈바닉 전류는 

즉시 전기분해 화학 반응을 일으켜, 

섬유증의 전기화학적 절제를 유도합니다. 

이 글에서는 중재적 시술에 대해 자세히 설명하고, 

이 기법의 장점과 한계에 대해 논의합니다.

결과
미국에서 개발된 EPI는 

반막성 힘줄이나 좌골신경이 직접적으로 관여하지 않고도 

PHTrSNE를 유발하는 섬유성 축적을 제거합니다. 

그러나 

이 기법은 압박성 신경병증의 경우에는 제한적으로 사용됩니다.

결론
초음파 유도 EPI는 

신속하게 시행할 수 있고, 

최소한의 침습적이며, 

치료를 효과적으로 하기 위해 환자가 활동(일이나 스포츠)을 중단하도록 강요하지 않는 기술입니다. 

이 기술은 

일반적으로 환자가 잘 견디는다는 사실과 결합되어, 

PHTrSNE의 치료에 초음파 유도 EPI의 사용을 뒷받침합니다.

Keywords: ablation techniques, entrapment neuropathies, tendon injuries, ultrasonography

Introduction

Proximal hamstring tendinopathy (PHT) is an overuse injury of current interest in orthopaedic and sports medicine. PHT is clinically characterised by pain in the sub-gluteal region, at the proximal insertion of the hamstring muscles onto the ischial tuberosity, with possible radiation to the posterior region of the thigh; sprinting and sitting for long periods are the activities in which the symptoms are typically exacerbated1, 2. The proximal insertion of the semimembranosus (SM) muscle onto the ischial tuberosity is superior-lateral, relative to the insertion of the conjoint tendon of the biceps femoris and semintendinosus.1,3–5. In patients with PHT, the proximal SM tendon is the one that is typically degenerated, appearing thickened at the lateral edge1.

In addition to this, the SM tendon is located in the vicinity of the Sciatic Nerve (SN)6, 7 which runs just lateral to the tendon (Fig. 1). In patients with PHT, fibrotic adhesions between the SM tendon and the SN occasionally form1,3,6,8; this anatomical alteration can cause entrapment syndrome of the SN, overlapping symptoms of tendinopathy, and those typical of an irritation of the nerve (sudden stabbing pain, sciatica, burning sensation or other paraesthesias). Proximal Hamstring Tendinopathy-related Sciatic Nerve Entrapment (PHTrSNE) therefore represents a possible complication of PHT. Rapid movements of hip flexion and extension or maximum hip flexion can worsen the symptoms, being the SN bound to the hamstring tendon complex (anchoring fibrosis)1,3,6,8. However, distinguishing symptoms of tendinopathy from those of neuropathy is fairly complicated.

소개

근위 햄스트링 건염(PHT)은

정형외과 및 스포츠 의학에서 현재 주목받고 있는

과용성 부상입니다.

PHT는

임상적으로 둔근 하부, 즉 좌골 결절에 근위부 햄스트링 근육이 삽입되는 부위의 통증과 함께

허벅지 뒤쪽 부위로 방사되는 통증이 특징입니다.

스프린트와 장시간 앉아 있는 것이

증상을 악화시키는 활동입니다1, 2.

반막근(SM)의 근위부 삽입은 대

퇴이두근과 반건막근의 관절성 힘줄의 삽입에 비해 우측 상측에 위치합니다.1,3–5.

PHT 환자의 경우,

근위부 SM 힘줄이 일반적으로 퇴화되어 측면 가장자리가 두꺼워 보입니다1.

이 외에도 SM 힘줄은

좌골신경(SN)6, 7 근처에 위치해 있으며,

힘줄의 바로 옆을 따라 이어집니다(그림 1).

PHT 환자의 경우,

SM 힘줄과 SN 사이에 섬유성 유착이1,3,6,8 형성되는 경우가 있습니다.

이러한 해부학적 변화는

SN의 갇힘 증후군을 유발할 수 있으며,

힘줄 병증의 증상과 신경 자극의 전형적인 증상

(갑작스러운 찌르는 듯한 통증, 좌골 신경통, 작열감 또는 기타 감각 이상)을 동반할 수 있습니다.

근위 햄스트링 건병증과 관련된 좌골신경 압박(PHTrSNE)은

PHT의 가능한 합병증입니다.

고관절 굴곡과 신전 운동의 빠른 움직임이나 최대 고관절 굴곡은

SN이 햄스트링 건 복합체에 묶여 있기 때문에(고정성 섬유증)

증상을 악화시킬 수 있습니다1,3,6,8.

그러나

건병증의 증상을 신경병증의 증상과 구분하는 것은 상당히 복잡합니다.

Figure 1.

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Transversal ultrasound section of the proximal semimembranosus tendon (asterisked) on the ischial tuberosity (IT). The sciatic nerve (indicated by the arrow) is easily recognizable lateral to the tendon. GM=gluteus maximus. Q=quadratus femoris.

근위 반막근 힘줄(별표 표시)의 횡단 초음파 섹션. 좌골 결절(IT)에 있는 힘줄의 측면에 좌골신경(화살표로 표시)이 쉽게 인식됩니다. GM=대둔근. Q=대퇴사두근.

Conservative treatment and infiltrative therapies for the treatment of PHT are generally preferred to surgery, which is considered when these do not lead to satisfactory results. Potentially applicable treatments are numerous: shockwaves, injections of PRP or corticosteroids, eccentric exercises and others (review2). In addition to the dearth of scientific evidence about their effectiveness, the limitation of these therapies is that they are unspecific and most likely ineffective for the treatment of PHTrSNE, in case the latter has been detected and taken into consideration. One scenario that can occur is that symptoms related to tendinopathy recede, while those derived from irritation of the SN persist.

PHT 치료를 위한 보수적 치료와 침윤성 치료는

일반적으로 수술보다 선호되는데,

수술은 만족할 만한 결과를 얻지 못할 때 고려됩니다.

적용 가능한 치료법은 다양합니다:

충격파, PRP 또는 코르티코스테로이드 주사, 편심 운동 등(2번 항목 참조).

그 효과에 대한 과학적 증거가 부족한 것 외에도, 이러한 치료법의 한계는 비특이적이며, 후자가 발견되어 고려되는 경우 PHTrSNE의 치료에 효과가 없을 가능성이 높다는 것입니다. 발생할 수 있는 한 가지 시나리오는 건병증과 관련된 증상이 사라지는 반면, SN의 자극으로 인한 증상이 지속된다는 것입니다.

Surgical treatment for managing PHT involves tenotomy of the SM tendon, which is sutured to the tendon of the biceps femoris1–2. The positive outcome of SM tenotomy is that the SN is anatomically unbridled from the tendon; the intervention is therefore also valid for the treatment of PHTrSNE. The only significant disadvantage of the intervention is the long post-surgical recovery time (from 1 to 12 months)2,9; this point certainly has a significant impact, especially for professional athletes, who may decide to postpone excessively or not to undergo surgery at all.

Finding a technique that can eliminate fibrosis between the SM tendon and the SN without requiring long periods of post-interventional recovery is therefore challenging. Ultrasound-guided Intratissue Percutaneous Electrolysis fulfils these requirements. The aims of this article are: i) to present the rationale for using this technique in the treatment of PHTrSNE; ii) to present the method of application and iii) to discuss both the strengths and limitations of the technique. The hypothesis of the Authors is that Ultrasound-guided Intratissue Percutaneous Electrolysis may be a useful complement to non-surgical proposals in the treatment of PHT with concomitant PH-TrSNE.

PHT 관리를 위한 외과적 치료에는

대퇴 이두근 힘줄에 봉합된 SM 힘줄의 절개술이 포함됩니다1-2.

SM 절개술의 긍정적인 결과는 SN이 해부학적으로 힘줄로부터 자유로워진다는 것입니다. 따라서 이 수술은 PHTrSNE 치료에도 유효합니다. 이 수술의 유일한 중요한 단점은 수술 후 회복 기간이 길다는 것입니다(1~12개월)2,9; 이 점은 특히 수술을 연기하거나 아예 수술을 받지 않기로 결정할 수도 있는 프로 운동선수들에게 큰 영향을 미칩니다.

따라서 SM 힘줄과 SN 힘줄 사이의 섬유화를 제거하는 동시에 수술 후 회복 기간을 길게 하지 않는 기술을 찾는 것은 어려운 일입니다. 초음파 유도 조직 내 경피적 전기분해는 이러한 요구 사항을 충족합니다. 이 글의 목적은 i) PHTrSNE 치료에 이 기술을 사용하는 근거를 제시하고, ii) 적용 방법을 제시하며, iii) 이 기술의 장점과 한계에 대해 논의하는 것입니다. 저자들은 초음파 유도 조직 내 경피적 전기분해술이 PH-TrSNE를 동반한 PHT 치료에 있어 비수술적 제안에 유용한 보완책이 될 수 있다는 가설을 세웠습니다.

Materials and methods

This study was conducted in accordance with the Declaration of Helsinki and complied with the ethical standards of the Muscles, Ligaments and Tendons Journal10.

Ultrasound-guided Intratissue Percutaneous Electrolysis

Intratissue Percutaneous Electrolysis (also known as Electrólisis Percutánea Intratisular or EPI) is a minimally invasive technique that involves galvanic current transfer within the treatment target tissue via a needle 0.30 to 0.33 mm in diameter. The galvanic current in a saline solution rapidly develops the chemical process of electrolysis, which in turn induces tissue ablation11. The EPI technique finds indications in the treatment of tendinopathies and fibrosis12–16.

The rationale for using EPI in the treatment of PH-TrSNE is the ability of the technique to specifically degrade fibrotic adhesions that bind the SN and SM tendon. Use of the technique is indicated only when le evident ultrasound signs of fibrosis between the SN and SM tendon are identifiable (Fig. 2) concomitant to the presence of the clinical pattern of PHTrSNE. Clinical assessment is needed, but is not sufficient to diagnose PHTrSNE, as the SN can be trapped in many other areas in the sub-gluteal region6.

Figure 2.

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Proximal hamstring tendinopathy-related sciatic nerve entrapment. Between the sciatic nerve (indicated by arrow) and the tendon of the semimembranosus (SM) a fibrotic accumulation is interposed (hyper-echoic area visible within the dashed box) which makes it difficult to distinguish the anatomical limits of the structures. IT=ischial tuberosity.

We apply the EPI technique using a specifically developed and medically certified (Directive 93/42/EEC) device (EPI Advanced Medicine® Barcelona, Spain). The main feature of the device is that the cathodic flow is the only one usable. To ensure maximum precision, the technique must be performed in an ultrasound-guided manner (US-guided EPI). We use the GE Healthcare Logiq S7 Expert® ultrasound with a linear probe (6–15 MHz) to guide the insertion of the needle. The operator must be well-trained in the use of the technique, and must have experience in the ultrasound examination of the lower limb.

Procedure for the US-guided EPI intervention

The patient lies in a prone position. The gluteal, subgluteal and trochanteric regions are disinfected by applying an appropriate protocol. The proximal tendon insertions of the hamstring muscles on the ischial tuberosity are identified by the operator guiding the ultrasound probe using their non-dominant hand; a transversal section is required to be able to simultaneously view the tendon complex and the SN7.

The needle is inserted by the operator with the dominant hand between the two structures through the gluteus maximus muscle, with an inclination of 0+30° around the vertical axis, in the medial-lateral direction (Figs. 3, 4); the SN, the SM tendon, the inferior gluteal artery and the inferior gluteal vein must be avoided during insertion. Depending on the physical characteristics of the patient, the needle can have a variable length, starting at 50 millimetres.

Figure 3.

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Ultrasound-guided insertion of the needle. Being the needle inserted perpendicular to the skin, it is displayed through movement of surrounding tissues.

Figure 4.

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Schematic diagram of the Ultrasound-guided Intratissue Percutaneous Electrolysis intervention. The medial edge of the sciatic nerve and associated vessels is represented by the vertical dashed line A. The lateral limit of the semimembranosus tendon is represented by the vertical dashed line B. The needle is inserted into the area bounded by line 1 (perpendicular to the axis joining lines A and B) and by line 2 (tangent to the superior-lateral point of the semimembranosus tendon). In this way, the technique can be performed safely, without structures other than the fibrosis being involved in the intervention.

When the needle tip is positioned inside the fibrosis, the galvanic current can be transferred; the intensity of the current is pre-set to 4 mA. The single application can have a variable duration between 2–10 seconds, depending on the tolerability of the technique to the patient (later) and the mechanical resistance offered by the tissue: where it is possible to penetrate the fibrosis with the needle by applying minimum pressure, the single application can be interrupted. At this point the needle is partially withdrawn (without exiting from the skin) and inserted again with a slight deviation to treat a different portion of the fibrotic accumulation.

One session can consist of 2–15 individual applications depending on the extent and hardness of the fibrosis. Consequently, administration of the galvanic current does not exceed 150 seconds in any one session; this should be taken into consideration as local anaesthetic drugs are not used. The session, including disinfection and dressing processes, lasts a maximum of 20 minutes in total.

Tolerability of pain

US-guided EPI is generally well-tolerated by patients. Some may have minor discomfort during the insertion of the needle. Application of the technique can cause mild to moderately strong pain. In addition to this, it is possible that the posterior femoris cutaneous nerve will be indirectly stimulated, causing tingling in the back of the thigh. Vagal reactions (nausea, headache, fainting) are rare but possible17; in this sense it is advisable to remind the patient before each session that he or she can ask for the session to be interrupted or stopped at any time. Bleeding in the area of needle insertion may occasionally occur. Patients sometimes report mild tenderness in the treated area, which generally does not last longer than 12–48 hours. The Authors do not advise conducting more than one session per week.

Discussion

The aims of this article are: i) to present the rationale for using US-guided EPI in the treatment of PH-TrSNE; ii) to present the method of application and iii) to discuss both the strengths and limitations of the technique. The hypothesis of the Authors is that Ultrasound-guided EPI may be an useful complement to conservative proposals when treating PHT with concomitant PHTrSNE. By using the US-guided EPI technique it is possible to eliminate the fibrosis interposed between the SN and SM tendon, degrading it by electrolytic ablation, without expecting the patient to suspend sporting or work activities for more than 48 hours after the intervention.

Strengths and limitations of the technique

US-guided EPI is a technique that allows specific treatment of the fibrotic adhesions that cause PH-TrSNE. The minimal invasivity and lack of necessity of suspending activities (work or sports) after treatment are the main strengths of this technique. The main limitation of the technique is the impossibility of completely resolving the symptoms if nerve irritation is caused by SN compression and not by its entrapment by the SM tendon.

EPI is an ultrasound-guided minimally invasive technique in which the needle is inserted with maximum precision into the structure to be treated, with minimal structural damage to any of the other tissues. In this way, one can eliminate a biomechanical cause of neuropathic symptoms, or the fibrosis that binds the SN to the SM tendon, without the nerve and the tendon being directly involved in the intervention. A further advantage of the mini-invasivity is the low chance of experiencing adverse events (in particular damage of the peri-nervous blood vessels).

One point that is certainly an advantage is that the patient does not need to undergo a specific rehabilitative intervention post US-guided EPI to render the treatment effective; this is particularly important for athletes suffering from PHTrSNE who will be required to suspend activities for 24–48 hours at most. US-guided EPI intervention does not therefore have a significant impact on the scheduling of sporting activities for an athlete.

The main limitation of the technique depends upon the type of anatomical alteration that has caused the neuropathy. In this article, SN entrapment neuropathy has been presented. It is however possible that the neuropathy is not derived from SN entrapment, but from compression of the nerve due to SM tendon hypertrophy1,3. The two conditions can be concomitant. Using the US-guided EPI intervention, it is not possible to reduce SM tendon hypertrophy in a consistent way; furthermore, on debriding the SN, it is possible that symptoms will persist because of compressive trauma suffered by the nerve. In such case, surgery remains the only therapeutic solution that can be considered.

Another possible scenario is the one in which the symptomatology persists due to irritation of the nerve at another location despite resolution of the PH-TrSNE. The anatomy of the sub-gluteal region is in fact highly complex and many different conditions (e.g. piriformis syndrome, gemelli-obturator internus syndrome, quadratus femoris pathology and gluteal disorders) provoking sciatica fall within differential diagnosis1,6. As a consequence of this, identification of the primary etiological cause determining the symptoms can be challenging. Instrumental investigations have an important role in detecting anatomical alterations1; to date, Magnetic Resonance Imaging (MRI) is typically the procedure of choice1–3,6,9,18, especially when lower back pain is concomitant (the exam is useful to exclude other pathologies). However, MRI findings can be not associated with symptoms. Medical history and clinical examination1, 2 can be helpful but, considering that different conditions present similar symptoms, only few tests have shown to have good sensibility and specificity in the diagnosis of SN entrapment6,19. For all these reasons, PHTrSNE remains fundamentally a diagnosis of exclusion.

Consequently, in order to eval‎uate the benefit of the US-guided EPI technique in the treatment of PH-TrSNE, the operator shall continuously monitor the evolution of the symptoms related to the disease. The Visual Analogic Scale (VAS)9,18 and the Victorian Institute of Sport Assessment-Proximal Hamstring Tendons (VISA-H) questionnaire20 are useful for this purpose. In particular, VISA-H has proven to have high degree of internal consistency and high test-retest reliability20.

Ultrasound-guided EPI in the treatment of tendinopathies

US-guided EPI finds indications in the treatment of tendinopathies and fibrosis. To date however, few studies have tested the effectiveness of the technique. The therapeutic utility of EPI (by some Authors replaced with the acronym PNE, Percutaneous Needle Electrolysis) was tested for the treatment of patellar tendinopathy12,13, sub-acromial syndrome14, chronic lateral epicondylitis15 and rectus abdominis-related groin pain16. The clinical results presented in this work are somewhat in conflict, especially given the different methodological choices of the Authors, in particular relative to the intensity and duration of administration of the galvanic current (which varied from 0.3 mA for 1.2 minutes to 3 mA for a few seconds) and suggested physiotherapy administered in combination with the technique.

The desired effects with the US-guided EPI are, on the one hand, elimination of the degenerated portion of the tendon and, on the other, development of an extremely localized and controlled inflammatory process, that may promote the tendon healing process. The histological effects of administering galvanic current within the tendon tissue are, however, only partially understood11,21–24. The method of applying the US-guided EPI technique presented in this article however differs to the one described in the articles listed above. In those articles, the technique is performed by inserting the needle within the degenerated portion of the tendon; the tendon is therefore the target of the therapy. In this work, the purpose was the electrolytic elimination of peri-tendinous fibrotic tissue, without treating the tendon. The ablative action is therefore the only one that has been fundamentally investigated. This also means there is no need to propose a specific rehabilitation protocol after the intervention.

Conclusions

US-guided EPI is a technique that allows specific treatment of the anatomical alterations that cause PHTrSNE, eliminating the fibrosis that binds the SN to the SM tendon. US-guided EPI is a technique that is quick to carry out, minimally invasive and does not force the patient to suspend their activities (work or sporting) to make the treatment effective. This, coupled to the fact that the technique is generally well-tolerated by patients, supports use of US-guided EPI in the treatment of PHTrSNE. Future studies with high quality designs are needed to test the efficacy of US-guided EPI in the treatment of PHTrSNE.

Footnotes

Conflicts of interest

The Authors declare no conflicts of interest concerning this article.

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