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Bone spurs that form along joints are known as osteophytes, and bone spurs that form at the attachment of tendons to bones are called enthesophytes.
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Bone spurs may cause pain by causing joint impingement, nerve irritation, and direct mechanical irritation to soft tissue.
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Not all bone spurs cause pain. Many bone spurs that are identified may be asymptomatic, and the osteophyte or enthesophyte a sign of the underlying degenerative or inflammatory pathology or instability.
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A cheilectomy is the removal of bony irregularities, or osteophytes, at the osteochondral margin of a joint that limit joint range of motion. Classically this applies to a hallux rigidus patient from the dorsal surface of the great toe, but this term may be applied to any joint where there is an impinging bone spur.
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Minimally invasive percutaneous bone spur or intratendinous calcification removal using a cannula or Tenex TX-Bone tool is a novel way to remove impinging bone spurs along joint surfaces or enthesophytes at tendon attachments.
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Patient selection should be based on careful examination, diagnostic blocks, and diagnostic imaging (e.g., ultrasound, x-ray, and magnetic resonance imaging [MRI]/computed tomography [CT]).
Anatomy and Pathology
Bony exostosis, or bone spurs, is thought to develop in response to inflammatory or mechanical stimuli. There are three main types of bony proliferation: (1) chondro-osteophyte or osteophyte at the synovium-articular cartilage junction along the joint margins; (2) traction spur or enthesophyte at the insertion of a tendon or ligament; and (3) syndesmophytes within the vertebral column along the annulus fibrosus or spinal ligament and associated with inflammatory spondyloarthropathies such as ankylosing spondylitis. ,
Osteophytes and enthesophytes have similar developmental process and composition. , Osteophytes are typically lateral outgrowths of bone at the joint line and are features of degenerative and inflammatory joint diseases or mechanical stress from joint instability. , The degree of spurring can vary considerably, and there is some evidence that small spurs can be unrelated to associated joint pathology. ,
Enthesophytes are also common and form in the direction of tension of the involved ligament or tendon. Enthesophytes can form at any tendon or ligament enthesis and are associate with microtears or in response to inflammatory pathology, and risk factors include spondyloarthritis and age. , One radiographic survey found heel spurs at the Achilles tendon or plantar fascia in 25% of the population. Similar to osteophytes, enthesophytes do not always indicate pain or disease. ,
Imaging and Ultrasound Findings
Conventional radiographs are the standard imaging modality for the assessment of osteoarthritis, and osteophytes are a common radiographic feature. Radiographic grading of osteophytes or enthesophytes is often subjective. Different semiquantitative scoring systems have been described. Few studies have examined the reliability of these scales or if there is a clinical correlation, and there is an no established universal or standardized grading method for osteophytes or enthesophytes.
Radiographs are in imperfect way of assessing osteophyte formation and enthesophyte changes. In some studies, ultrasound has been shown to be more sensitive than conventional radiography in detecting osteophytes in the hand and knee. Sonographic findings of bone spurs, whether an osteophyte or enthesophyte, include a hyperechoic cortical protrusion with acoustic shadowing. Different grading systems have been described, but few studies have examined the reliability of these scales and clinical correlation, and a review of these scales is beyond the scope of this chapter. Dynamic ultrasound can also be used to visualize impingement due to osteophytes.
Ultrasound evaluation can also be used for preprocedural planning, and the osteophyte or enthesophyte should be assessed for its size (length, width, and depth) in long and short axis. Examination of surrounding neurovascular structures is necessary to assess a treatment pathway (e.g., place an instrument safely down to the bone spur for possible removal).
Treatment Options
Asymptomatic osteophytes or enthesophytes do not need treatment, and conservative management includes medications, changing footwear, or adding padding. Ultrasound-guided fenestration and cortisone injection have been reported to be an effective way to manage anterior ankle impingement. In a retrospective case series of 49 patients with anterior ankle impingement, Nazarian et al. showed 4/79.6% of patients were able to avoid surgical treatment of their painful anterior ankle impingement at follow-up (average 27 months).
Symptomatic spurs that fail conservative management may need to be removed. Open or arthroscopic/endoscopic surgery is the standard of care for painful osteophytes that limit motion or cause impingement, and painful enthesophytes within a tendon. , Using a cheilectomy to remove painful dorsal osteophytes for hallux rigidus has been well described in the literature, with open, arthroscopic, and percutaneous approaches being described. The literature on percutaneous approaches is limited. Percutaneous minimally invasive techniques for dorsal cheilectomy have been reported with a wedge burr (Wright Medical, Memphis, TN) and have similar complications to an open cheilectomy. One limitation may be a higher reoperation rate with the percutaneous palpation-guided approach. One publication comparing open versus minimally invasive cheilectomy with a wedge burr had a higher reoperation rate with the minimally invasive approach (12.8% compared with 2.6% with open surgery).
Minimally invasive arthroscopic and endoscopic resection of bone spurs and exostosis have also been reported at varying locations. Anterior ankle impingement , has also been managed with arthroscopic removal of bone spurs, effectively treating pain and loss of motion. Successful arthroscopic and endoscopic resection of olecranon spur and endoscopic management of chronic Osgood-Schlatter disease have also been described in a case series. Compared with open procedures, arthroscopic procedures have shorter recovery time and quicker resumption of sport. , Endoscopic calcaneoplasty of Haglund deformity has been shown to be superior to open techniques, with less morbidity and fewer complications. , Osteophytes can occur at other locations, but the literature on percutaneous and arthroscopic/endoscopic spur excision is limited.
Ultrasound-guided percutaneous spur excision has not been widely described in the literature. Excision of a painful osteophyte or enthesophyte can be performed with an 11-gauge × 4.5-inch Jamshidi trocar and cannula ( Fig. 33.1 ) or an OnControl trocar and cannula or more recently with the aid of the Tenex TXB Micro Tip bone tool ( Fig. 33.2 ).
Patient Selection
Any patient with a painful osteophyte or enthesophyte that is safely accessible may be a candidate for a bone spur excision, cheilectomy, or tendon enthesophyte excision. Whether a bone spur needs to be addressed as part of a patient’s treatment plan can be assessed by a process of exclusion and the use of carefully targeted diagnostic blocks. Many bone spurs that are identified may be asymptomatic, and the osteophyte or enthesophyte may be a sign of the underlying degenerative or inflammatory pathology.
In cases of calcaneal heel spur, radiographic and histologic findings suggest that changes within the fascia rather than the spur are primarily responsible for pain. In one study of subjects who underwent an endoscopic plantar fasciopathy, 53.8% of the patients had a calcaneal spur. The spur was never resected in these subjects, and the outcomes of the plantar fasciopathy remained the same whether the patients had an associated spur or not. Other studies have also shown good results with treating the plantar fascia alone, again showing that, although calcaneal spurs may be present, there are many other causes of heel pain (e.g., plantar fasciitis, tears in the plantar fascia, fat pad atrophy, calcaneal fractures).
The challenge of localizing the source of pain extends to other locations of osteophytosis or enthesophytes. Image-guided diagnostic blocks can be very helpful in confirming whether the bone spur is a cause of pain or not. Use a minimal amount of 1% lidocaine around the bone spur to increase the diagnostic accuracy of the block and assess whether good anesthesia is achieved within a few minutes of the injection. Commonly, osteophytes are associated with degenerative or inflammatory joint disease or instability, and enthesophytes are associated with partial tearing of ligament on tendon. The spur may be asymptomatic or only one of a number of factors contributing to pain. Identifying and treating the underlying source of pain is possibly essential for a successful treatment plan.
The ultrasonic percutaneous treatment of osteophytes and enthesophytes is early, and more research is needed on patient outcomes and possible adverse events. Caution should be taken in patient selection. Joint pain, night pain, and resting pain may be negative prognostic factors, and symptoms of impingement or osteophyte rubbing against footwear may be positive prognostic signs that the patient will respond well to percutaneous treatment.
Equipment
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Sterile procedure tray with nonfenestrated sterile tray cover
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Fenestrated drape or sterile cloth or paper towels to create a sterile field
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Sterile prep applicators (e.g., ChloraPrep or Betadine) with manufacturer-required drying time to establish a dry sterile barrier prior to the procedure
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4 × 4 gauze sponges
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Sterile surgical marking pen
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Introducer with an 18-gauge needle or an 11-blade disposable scalpel
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Sterile 3- to 10-cc syringe for skin to target local anesthesia
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27-gauge needle for skin wheel anesthesia
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25- to 22-gauge needle for anesthetizing the soft tissue pathway to the target
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Steri-Strips for wound closure
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Tincture of benzoin for sterile adhesive to hold Steri-Strip in place
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2 × 2 gauze for hemostasis under waterproof wound dressing
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Tegaderm for waterproof sterile wound barrier
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Diagnostic ultrasound machine with a high-frequency linear array transducer or a low-frequency curvilinear transducer for deeper approaches
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Sterile probe cover and sterile gel
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Percutaneous cutting tool: Jamshidi 11-gauge × 4.5-in trocar and cannula, Tenex TX-Bone Micro Tip Bone tool kit, or 11- to 15-gauge OnControl trocar and cannula
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Injectates
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Lidocaine 1% or 2% with and/or without epinephrine and normal saline for skin wheel and local anesthesia and irrigation as needed. If 11-blade is planned as the introducer to puncture the skin, consider using epinephrine for the skin wheel.
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Ropivacaine 0.2% to 0.5% and lidocaine 1% or 2% to help provide longer-term anesthesia from the procedure.
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Optional: an orthobiologic injectate to help facilitate healing of any damaged tissue after the bone spur removal (e.g., dextrose prolotherapy, platelet-rich plasma [PRP] amniotic membrane graft, bone marrow concentrate).
Injectate Volume
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Local anesthesia:
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Skin wheel 2 to 5 mL of lidocaine 1% with or without epinephrine
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3 to 10 mL of mixture of 1 lidocaine 1 or 2% with or without epinephrine mixed with an equal part of ropivacaine 0.2% to 0.5%
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Ultrasound-Guided Bone Spur Resection (Author’s Preferred Technique)
Patient and Clinician Position
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Patient position will vary depending on the target osteophyte or enthesophyte.
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The physician should preferably be seated across from the ultrasound screen and the patient’s limb between the physician and the ultrasound screen for good ergonomics.
Transducer Orientation
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Short- and long-axis views over the bone spur to identify neurovascular structures and plan how much bone needs to be removed to address the soft tissue impingement or restricted joint range of motion. Power Doppler imaging can be used to help localize neurovascular structures.
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The pathway to access the bone spur needs to be planned to minimize risk of iatrogenic injury to the neurovascular structures.
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Detailed knowledge of the neurovascular anatomy will help to ensure a safe pathway to place the cheilectomy tool. Always use Doppler settings (e.g., Doppler perfusion index [DPI] or color Doppler) prior to starting the procedure to make sure no significant blood vessels or nerves are in the way of the cheilectomy tool placement.
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Once the pathway for the needle has been chosen, the entry point should be marked on the skin with a sterile surgical marking pen.
Needle Orientation
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The needle should be placed in-plane to ensure visualization of the needle tip and cutting device. This may necessitate a distal to proximal or medial to lateral approach, etc., depending on the patient’s target bone spur location.
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A smaller-gauge anesthetic needle can be used to confirm the pathway for the cutting device to safely access the spur, keeping in mind the neurovascular anatomy and musculoskeletal tissues in the pathway and adjacent to the spur.
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Anesthetic should be injected around the spur/periosteum, ensuring to cover the three-dimensional location of the spur. Local anesthesia with a 27- to 25-gauge, 1.25-inch needle to make a skin wheel and a 25- to 22-gauge, 1.5- to 4-inch needle to anesthetize a pathway for the cutting tool to the bone spur.
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In enthesophytes, note any soft tissue defects adjacent to the bone spur that “open up” when injecting the anesthetic. These can represent interstitial tears or delaminating tears and may also need to be addressed (e.g., with an orthobiologic injection) in addition to removing the bone spur.
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Target
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Ensure adequate anesthesia of the bone spur and adjacent soft tissue to facilitate a painless procedure. When possible, an adjacent nerve block should be considered to help with pain during the procedure (e.g., tibial and sural nerve block for Achilles spur or Haglund resection).
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An 18-gauge, 1- or 1.5-inch hypodermic needle or an 11-blade disposable scalpel is used as an introducer to puncture the patient’s skin to facilitate entry of the larger-bore cutting tools.
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The cutting tool is placed through the introducer hole under, and advanced under, ultrasound guidance to the surface of the bone spur using in-plane views. Orthogonal out-of-plane views are obtained to confirm needle placement. Alternate probe positions will ensure the three dimensions of the bone spur are addressed during the procedure.
Consideration if Using the Jamshidi Trocar
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If using the Jamshidi trocar and cannula, the trocar is removed from the cannula. A 3- to 5-cc syringe with lidocaine with epinephrine is placed on the open Luer-Lock port after removing the trocar in the event the patient needs more anesthesia. This also covers the Luer port opening and helps maintain sterility. Blood backing into the cannula alerts the physician for the need for more hemostasis, and lidocaine with epinephrine is injected through the cannula.
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The cannula is then twisted clockwise and counterclockwise and advanced through the bone spur like a leather punch or kitchen apple core tool until the cannula is seen to be all the way through the bone spur on ultrasound imaging. The bone spur is now inside the cannula ( Figs. 33.3–33.5 ).
