Groin Pain Etiology: Spine and Back Causes

© Springer International Publishing Switzerland 2016

Brian P. Jacob, David C. Chen, Bruce Ramshaw and Shirin Towfigh (eds.)The SAGES Manual of Groin Pain10.1007/978-3-319-21587-7_9

9. Groin Pain Etiology: Spine and Back Causes

Charles H. Li1, Victor W. Chang2, Irene Wu3 and Daniel C. Lu 
(1)

Department of Neurosurgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
(2)

Department of Neurology and Neurosurgery, Henry Ford Hospital, Detroit, MI, USA
(3)

Department of Anesthesiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
Daniel C. Lu
Keywords

Groin painSacroiliac joint dysfunctionLumbar stenosisLumbar disk degenerationSpondylolisthesisHerniated diskPeripheral nerve entrapment

Introduction

Groin pain is a common cause of complaints in the primary care clinic setting [1]. Groin injuries are responsible for approximately 5 % of all athletic injuries and account for 10 % of visits to sports medicine clinics [2]. In the clinical evaluation of groin pain, it is important to elicit the history of onset [3]. Although the differential is wide, altered sensation or weakness can raise suspicion for neurological causes such as peripheral nerve entrapment , herniated disc, or lumbar disc degeneration [3]. Fractures or malignancy are always within the differential and should be suspected when there is a history of pain at rest or at night. Sacroiliac joint dysfunction can be a chronic cause of groin and lower back pain that is commonly underdiagnosed [4].

Sacroiliac (SI) Joint Dysfunction

The SI joint is a synovial joint with hyaline cartilage on the sacral side of the joint [4]. It is believed that the joint is entirely innervated by the sacral dorsal rami [5]. The joint is mostly a bony structure supported by a number of ligaments and the surrounding muscles. The joint shares these muscles with the hip joint and is subject to all the same shear forces that the hip experiences [4]. SI joint pain is commonly due to trauma or strain. Repetitive motions associated with athletic activities can also cause repetitive shear .
Physical Exam
Most of SI joint pain is referred to the buttocks (94 %), lower lumbar region (72 %), and lower extremities (50 %) [6]. Pain that is localized to the groin is an unusual presentation, seen in around 14 % cases [6]. There are extensive innervations in the hip and groin area, making physical examination difficult and nonspecific. Three provocative SI joint movements can detect SI joint dysfunction with a sensitivity of 77–87 % [7]. Common tests of SI joint function include Laguere, Gillette, Patrick, and the Gaenslen tests [79]. Further, radiographic exam may be helpful in corroborating physical exam findings, but radiology alone is not sufficient for diagnosis [4]. Elgafy et al. [10] showed that CT scans for SI joint dysfunction had a sensitivity of 57.5 % and a specificity of 69 %. SI joint blocks can be used as a diagnostic tool and have been associated with a positive predictive value of 60 % when used with three physical exam tests [6, 11].
Treatment
Patients with SI joint dysfunction should be treated with a multimodal approach. Results of treatment consisting of physical therapy, orthotics, joint blocks, surgery, and neuroaugmentation have been highly variable [4]. Physical therapy exercises focus on movements that can strengthen the hip muscles and stabilize the pelvis [12]. Placement of an orthotics belt has also been useful in some treatments as a way of limiting further motion that can cause increased injury to the joint [13]. Several studies have also noted relief of symptoms and improvement in function with intraarticular injections of the SI joint [1417]. This can further be followed with radiofrequency rhizotomies of the innervation to the SI joint for more lasting analgesia. There is no class I evidence to support this procedure.
Historically, surgical treatment was used only when the SI joint was proven to be unstable [18]. Traditional techniques for SI joint fusion involved large open procedures, which introduced a great amount of morbidity and were of limited clinical benefit. With the recent advent of minimally invasive techniques to fuse the SI joint, there is growing interest among spine surgeons to pursue this technique. However, to date there is not a great deal of high-level evidence to support this procedure. Neuroaugmentation is a new modality for treatment of SI joint pain, and case reports [19, 20] have suggested that it may be a standard treatment option in the future.

Lumbar Disc Degeneration

Lumbar disc degeneration is a known cause of persistent groin pain [21]. The groin is innervated by the genitofemoral and ilioinguinal nerves; degeneration of the spinal canal can cause referred pain to the groin. In particular, patients with herniated discs (most commonly in the L4–L5 or L5–S1 levels) have been known to report groin pain [21]. These discs can cause compression on transversing sacral nerve roots (S1–S3). Additionally, herniation at the L1/L2 levels is rarer but can cause characteristic symptoms of groin pain, manifesting as buttock pain and anterolateral thigh pain [22].
Diagnostic Workup
Studies have shown that around 21 % of patients with lower lumbar disc degeneration or herniation have had associated symptoms of groin pain [23]. Making a diagnosis of discogenic groin pain is difficult due to the nature of the disease presentation. There has been controversy in the use of discography to diagnose discogenic pain [24]. MRI is commonly used as a noninvasive approach to diagnosing lower back pain from degenerative disc disease [25], and ultrasound imaging has been shown to have a 90 % sensitivity and 75 % specificity for finding disc degeneration when combined with discography [26].

Lumbar Stenosis

Stenosis is defined as the narrowing of the spinal canal, usually to an absolute diameter of less than 75 mm2 as characterized by imaging [27]. Similar to degeneration, nerve root stenosis at the L1/L2 levels will affect the L2/L3 nerve roots, manifesting in a positive femoral stretch test and anterolateral thigh pain [28]. Imaging is not definitive; in one study, more than 30 % of patients had images consistent with lumber stenosis but did not feel any of the associated symptoms [29]. Diagnosis is made through physical examination using similar tests reported for SI joint dysfunction, as well as through exclusion of other possible diagnoses. Once diagnosed, the most effective treatment for spinal stenosis involves patient education, therapy, exercise, and training [27]. For symptoms of pain, exercises that focus on strengthening the muscles involved in thoracic extension and lumbar rotation were found to be most effective in relieving pain [30, 31], presumably because these types of exercises were the most important for increasing flexibility in the groin region. Intervention for severe spinal stenosis includes epidural steroid injections and surgery. Injections have increased in popularity in recent years, but their efficacy has been controversial [32]. Surgical versus nonsurgical approaches have recently been evaluated by the Spine Patient Outcome Study (SPORT) [33]; the authors concluded that patients with degenerative spondylolisthesis treated with surgery had significantly better outcomes at four years compared to those who were managed noninvasively. The outcomes for patients with stenosis without spondylolisthesis were not as clearly defined.

Herniated Disc

Herniated discs are one of the most common discogenic causes of groin pain. The most common sites of herniation are at the L4–5 and L5–S1 levels. Additionally, other sites of herniation that will manifest as groin pain include the L1/L2 and S3/S4 levels. S3/S4 involvement likely is not due to direct S3/4 disc herniation, rather by S3/4 nerve root compression by more rostral disc herniations (i.e., L4–5 or L5–S1). L1/L2 disc herniation will localize to the inner thigh, while a herniation that affects the S3/S4 level will localize to the scrotal region. It is believed that decreased hydration of the annular disc leads to decreased ability of the disc to cushion load. This dehydration can be due to age, genetics, and environmental factors. A sharp stabbing pain that radiates down to the extremities below the knees is highly suggestive of herniation [34]. On physical exam, increased pressure on the annular fibers of the disc will help distinguish herniation from low back pain, which is typically made worse by twisting motions of the lower back muscles. The straight leg raise is usually indicative of a pinched nerve or nerve root.
Nonsurgical approaches to the management of a herniated disc are similar to those for other forms of disc degeneration. These approaches include physical therapy, focused exercises, and epidural injections. The natural history of lumbar herniated disc is that a majority of patients will resolve their symptoms without intervention given enough time. Surgery may be indicated in severe cases that cause significant pain or disability and also in cauda equina syndrome [34].

Spondylolisthesis

Spondylolisthesis refers to anterior subluxation of the vertebral body that is caused by a defect in the pars interarticularis [35]. Spondylolisthesis falls into three categories: spondylolysis, isthmic, and degenerative [36]. Isthmic is the most common form, occurring in 4–8 % of the general population and is found twice as often in males compared to females [37]. Although isthmic spondylolisthesis can usually be detected in childhood, patients usually do not present with symptoms until later in life. Presenting symptoms include pain in the lumbar area that can manifest as groin pain that radiates into the buttocks and thighs [37]. The pain can be exacerbated with weight lifting maneuvers or Valsalva. Higher grade spondylolisthesis can also manifest in hamstring tightness [37]. Degenerative spondylolisthesis usually presents much later in life and is caused by long-standing instability in the lumbar segments. The instability is most frequently due to arthritis, malfunction of the ligaments stabilizing the lumbar joints, or ineffective muscle stabilization [38]. The treatment for spondylolisthesis is dependent on the extent of listhesis. Most patients who present are asymptomatic and can be managed nonoperatively using modalities such as steroid injections, brace therapy, and restriction of heavy lifting and intense athletic activities [37]. When nonoperative therapies fail, surgical intervention may be needed. Generally, the indications for surgery include (1) persistence of debilitating pain and function, (2) progression of listhesis greater than 30 %, and (3) cosmetic deformities that result in functional disability [37]. Typical surgical procedures involve decompression and fusion of the segments undergoing listhesis.
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Apr 23, 2017 | Posted by in PAIN MEDICINE | Comments Off on Groin Pain Etiology: Spine and Back Causes

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