Narrative Review Disorders of the Cervical Vertebral Column Part 2: Update on Current Surgical Techniques, Application and Case Selection

Narrative Review Disorders of the Cervical Vertebral Column Part 2: Update on Current Surgical Techniques, Application and Case Selection | Authorea try { document.documentElement.classList.add('js'); } catch (e) { } var _gaq = _gaq || []; _gaq.push(['_setAccount', 'G-8VDV14Y67G']); _gaq.push(['_trackPageview']); (function() { var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); })(); Skip to main content Preprints Collections Wiley Open Research IET Open Research Ecological Society of Japan All Collections About About Authorea FAQs Contact Us Quick Search anywhere Search for preprint articles, keywords, etc. Search Search ADVANCED SEARCH SCROLL Equine Veterinary Education This is a preprint and has not been peer reviewed. Data may be preliminary. 5 February 2025 V1 Latest version Share on Narrative Review Disorders of the Cervical Vertebral Column Part 2: Update on Current Surgical Techniques, Application and Case Selection Authors : Rachel Tucker 0000-0003-1852-3515 [email protected] , Jonathan Anderson , Svea Marie Schmidt , and Jenny Stavisky Authors Info & Affiliations https://doi.org/10.22541/au.173875361.17102120/v1 436 views 362 downloads Contents Abstract Information & Authors Metrics & Citations View Options References Figures Tables Media Share Abstract Summary Pathologic conditions of the cervical vertebral column cause combinations of pain, neurologic deficits and behavioural issues that affect welfare and performance in the horse. A diagnosis of cervical vertebral malformation (CVSM) is associated with a high mortality rate, especially when identified in young animals. Surgical treatment offers the potential for long term improvement or resolution of clinical signs, at the cost of the potential for complications and an initial increased financial outlay. There are difficulties with extrapolating published outcomes to the individual case, however representative reported outcomes following cervical vertebral interbody fusion are an improvement in ataxia of 1 grade in 60-86% of horses, 2 grades in 7-74% of horses and 3 grades in 1-13% of horses, with a fatal complication rate of 6-18%. Multiple factors such as lesion location, cause of stenosis and duration of compression affect surgical outcome. Case selection should take into account factors such as severity of initial presentation, temperament, intended use and owner attitudes. Uniportal endoscopic foraminotomy is in its infancy but shows great promise as a minimally invasive procedure able to relieve clinical signs associated with spinal nerve impingement in the cervical vertebral column. This condition is being increasingly recognised, particularly in Warmblood sport horses. Details of greater case numbers and longer term follow up is required but around 87% of the first operated cases have shown significant improvement in signs. Cervical articular process joint arthroscopy/arthrotomy is uncommonly indicated but offers a low risk and successful treatment option for horses diagnosed with clinically relevant and surgically accessible intra-articular fragments or loose bodies within these joints. Narrative Review Disorders of the Cervical Vertebral Column Part 2: Update on Current Surgical Techniques, Application and Case Selection Authors Rachel Tucker BVetMed MVetMed DipECVS MRCVS Liphook Equine Hospital, Liphook, UK [email protected] Jonathan Anderson BVM&S DipACVS MRCVS Rainbow Equine Hospital, Malton, Yorkshire, UK [email protected] Svea Marie Schmidt DVM Tierklinik Lüsche GmbH, Essener Str. 39a, 49456 Bakum, Germany [email protected] Jenny Stavisky BVM&S PhD PGCHE FHEA MRCVS Vet Partners, York, UK [email protected] Author’s declaration of interests No conflicts of interest have been declared. Ethical animal research Ethical review not applicable for this review article. Source of funding None. Summary Pathologic conditions of the cervical vertebral column cause combinations of pain, neurologic deficits and behavioural issues that affect welfare and performance in the horse. A diagnosis of cervical vertebral malformation (CVSM) is associated with a high mortality rate, especially when identified in young animals. Surgical treatment offers the potential for long term improvement or resolution of clinical signs, at the cost of the potential for complications and an initial increased financial outlay. There are difficulties with extrapolating published outcomes to the individual case, however representative reported outcomes following cervical vertebral interbody fusion are an improvement in ataxia of 1 grade in 60-86% of horses, 2 grades in 7-74% of horses and 3 grades in 1-13% of horses, with a fatal complication rate of 6-18%. Multiple factors such as lesion location, cause of stenosis and duration of compression affect surgical outcome. Case selection should take into account factors such as severity of initial presentation, temperament, intended use and owner attitudes. Uniportal endoscopic foraminotomy is in its infancy but shows great promise as a minimally invasive procedure able to relieve clinical signs associated with spinal nerve impingement in the cervical vertebral column. This condition is being increasingly recognised, particularly in Warmblood sport horses. Details of greater case numbers and longer term follow up is required but around 87% of the first operated cases have shown significant improvement in signs. Cervical articular process joint arthroscopy/arthrotomy is uncommonly indicated but offers a low risk and successful treatment option for horses diagnosed with clinically relevant and surgically accessible intra-articular fragments or loose bodies within these joints. In all cases a clear understanding of the goals of surgery and careful discussion of the process, the risks and the anticipated outcome helps an owner and their clinical team make the most appropriate decision for their animal, in a veterinary field which still contains many unknowns for the individual patient. Research in this field is very active, with much new information forthcoming. Introduction There has been significant progress in the diagnosis and treatment of conditions of the neck in recent years. The advent of computed tomographic (CT) imaging systems capable of imaging the entire neck of the horse has opened a window on the anatomy of the neck in health and disease, bringing with it new diagnoses and better understanding of previously recognised conditions. New surgical treatments have been developed to treat the lesions identified, with emerging availability of minimally invasive procedures offering curative treatment options whilst reducing post operative morbidity and facilitating early return to function. Established procedures such as cervical vertebral interbody fusion (‘Wobbler surgery’) remain important, and may now benefit from new implants and instrumentation developed through collaboration with the human sector, which offer the promise of improved outcomes. Achieving an accurate diagnosis is paramount for applying the most appropriate treatment, as discussed in part 1 of this narrative review. This second part seeks to describe and appraise the surgical treatments now available, including cervical vertebral interbody fusion, uniportal endoscopic foraminotomy and arthroscopic removal of osteochondral loose bodies from the articular process joints. The goal is to allow an up to date understanding of the procedures, what they might treat and the risk/benefit consideration of these options when planning treatment of cervical dysfunction. A variety of fracture configurations and atlanto-axial (sub)luxation are also amenable to surgical treatment, but take a different course in their history and presentation and are therefore not included in this discussion. CERVICAL VERTEBRAL INTERBODY FUSION PRINCIPLES Cervical vertebral interbody fusion (CVIF) is the technique used to arthrodese two adjacent cervical vertebrae. It is primarily performed to prevent movement at a spinal segment in which there is demonstrable compression of the spinal cord resulting in cervical vertebral stenotic myelopathy (CVSM). In this procedure, the vertebrae are positioned in alignment and fusion is then performed to provide a continuous vertebral canal. The purpose of the surgery is to alleviate spinal cord compression and facilitate its healing in order to restore the horse to a functional neurologic status. Stabilisation techniques can be performed either dorsally by arthrodesis of the articular process joints (Crecan et al 2022) or, far more commonly, ventrally by removal of the intervertebral disc and facilitation of bony union of the intervertebral joint. In horses with dynamic instability (Type I CVSM), resulting from malarticulation of adjacent vertebrae, cervical arthrodesis stabilises the affected vertebral junction. In horses with static instability (Type II CVSM) due to medial enlargement of pathologic articular processes, arthrodesis aims to minimise further spinal cord trauma and enable disuse atrophy of the articular processes and resolution of stenosis. TECHNIQUES There are four described methods to facilitate ankylosis of the adjacent cervical vertebral bodies. Placement of a titanium Kerf Cut Cylinder (KCC) and bone graft is the most long established and widely adopted technique. Techniques using poly axial screws and rods and 3D-printed titanium plates have been developed more recently. Both methods utilise a porous metal ‘spacer’ implanted into the disc space to create an arthrodesis. Use of locking compression plates has also been described. For all methods, the ventral surface of the affected vertebrae and intervertebral disc are approached via a ventral midline incision, with the horse positioned under general anaesthesia in dorsal recumbency. The cervical vertebrae are aligned in extension (slight flexion for C6-T1), with surgery performed under radiographic control, as dictated by the procedure used. Kerf Cut Cylinder Interbody Fusion CVIF surgery in horses has been performed on more than 2000 horses (Dr B. Grant personal communication), initially as an adaptation of the Cloward procedure used to stabilise cervical spinal segments in humans (Cloward 1958). First performed in horses in 1978, the intervertebral disc and a portion of the vertebral endplates in the adjacent vertebral bodies were removed, followed by tamping of a bone dowel into the created cavity to achieve immobilisation of the intervertebral space and to promote ankylosis (Wagner et al 1979, Wagner et al 1981). The technique evolved, and by 1983 the bone dowel was replaced with a fenestrated, stainless steel cylinder (Bagby Basket) which could be packed with cancellous bone taken from preparation of the implant bed (DeBowes 1984, Moore et al 1993). This implant was named after Dr George Bagby - a human surgeon - who, along with equine surgeon Dr Barrie Grant, was instrumental in developing the technique in both humans and horses. Subsequently a partially or fully threaded, fenestrated, titanium ‘basket’ was developed - the Kerf Cut Cylinder (KCC) (Figure 1). This could be torqued into place rather than tamped, reducing the likelihood of implant migration. It also allowed a cylinder of bone to be left in the dorsal-most aspect of the drill hole (kerf), aimed to speed up osseous fusion and reduce the risk of fracture at the drill site. The KCC was similarly packed with cancellous bone harvested from the drillings (Grant et al 2003a,b). For foals and smaller horses a smaller implant (15mm diameter) and instrumentation are also available. CVIF was initially performed between C2/3 and C6/7, with surgery more recently reported at C7/T1 to treat spinal cord compression, intervertebral foramen stenosis or joint instability caused by discospondylitis at this level (Grant et al 2023, Santos et al 2023). Surgery at C7/T1 is technically more challenging than in the mid neck and requires specific patient positioning, the use of long handled instruments, and thorough knowledge of the anatomy of the region (Janicek 2023). CVIF can be performed at more than one level, with successful triple level fusion reported (Grant et al 1985, Grant et al 2007, Huggons et al 2007). Once a spinal segment is stabilised there is a gradual transition from the implant providing biomechanical stability to a full bone union that forms through the fenestrations in the implant. This process is expected to be progressing radiographically at 12 weeks post surgery (Wagner et al 1981). A single case report of a non-osseous union in a dressage horse that competed successfully for 12 years after placement of a Bagby Basket implies that a non-osseous union can still adequately stabilise the intervertebral joint (Dukti et al 1983). Horses with dynamic compression of short duration can show improvement in ataxia within days of surgery, whereas those with static compression caused by enlarged articular processes may take more than a year to reach their full healing capacity. Cervical stabilisation methods in man have progressed significantly from the Cloward procedure and in recent years comparable new methods have also emerged in horses. The goal has been to address specific surgical challenges in this region. These include: high biomechanical forces and motion; the risk of significant or fatal complications in the intra-operative and early post-operative period; increasing access to surgery by reducing technical difficulty and reducing specialised instrumentation whilst continuing to achieve immediate stability of the construct to enable early post-operative comfort and to allow early rehabilitation. Polyaxial Screws and Rods Currently the gold standard for rigid lumbar vertebral stabilisation in man is the use of an inter body fusion device (IFD) in conjunction with pedicle screws and connecting rods. This technique has been described in a proof of concept study in 4 normal horses and in a series of 10 clinical cases (Aldrich et at 2018, Pezzanite et al 2022). Titanium pedicle screws have a mobile ‘tulip’ head that allows up to 50 degrees of articulation and accepts a titanium rod. This mobility gives flexibility for screw positioning within the bone, reducing the technical difficulty of surgery. Following removal of the adjacent end plates and disc, a porous metal spacer is placed into the disc space to maintain stability and to encourage osseointegration across the joint. Paired 4.5mm pedicle screws are placed into each vertebral body, with 2 rods placed between them to span the joint. The screw heads are locked to the bars whilst the joint is maintained under compression to achieve stability. Use of this construct in 4 clinically normal horses did not result in implant failure or migration, with new bone formation occurring around the construct and within the disc spacer at 8 months post implantation (Aldrich et al 2018). More recently, use of the disc spacer has been omitted from the surgical procedure, with early work indicating this to reduce surgical time and financial cost without compromising outcomes (Easley 2024). Omission of the disc spacer did not affect measures of spinal stability in a canine ex-vivo study (Marinho et al 2022). Proponents of this technique suggest it to be less technically demanding than use of a KCC and it requires less specialised instrumentation. In addition, fracture risk may be reduced as no bone is removed from the vertebral bodies. Custom Titanium Plate and Spacer This innovative arthrodesis method utilises computer aided design (CAD) and metal additive manufacturing processes (3D printing) to create implants specific to the anatomy of the horse, designed to address the same surgical and biomechanical challenges as previously described. Two implants have been created: the cervical plate and spacer a (CPS) for arthrodesis at C2/C3 to C5/C6, and the zero-profile anchored spacer a (ZPS) for C6/C7 and C7/T1 (Figure 2). Smaller implants are also available. As with other CVIF devices, implants have undergone ex vivo biomechanical testing, the added benefit being the ease of ongoing refinement through the 3D printing process. In the mid cervical region the intervertebral disc is removed and a porous titanium spacer is placed, designed to aid osseous integration. This is locked into place and the vertebrae stabilised by an overlying plate and 6.5mm cancellous locking screws (Mannaa et al 2023, Rossignol 2024). In the caudal neck the plate and spacer are combined into one implant, placed using an aiming device designed to aid accurate implant positioning and reduce soft tissue dissection in this deep location close to the carotid bifurcation. In the mid neck, a slightly longer incision is required as compared to use of the KCC, and as with all methods care is required to reduce the risk of iatrogenic soft tissue injury, particularly of the recurrent laryngeal nerve. The technique has been performed on 72 horses to date, with ex-vivo work and a case series in press (Dr. F. Rossignol personal communication). Locking Compression Plates Locking compression plates (LCPs) have been used successfully to achieve ventral stabilisation (Reardon et al 2009, Vitte et al 2012, Rossignol et al 2015, Kühnle et al 2018). Plates are more widely available than other CVIF devices and their use more familiar by surgeons who perform fracture fixation. Ex-vivo work demonstrated initial construct strength to compare favourably with the normal neck and with the Kerf Cut Cylinder (Reardon et al 2009b, 2010). However its placement on the ventral, compressive surface of the vertebrae deviates from biomechanical principles that dictate plating the tension side of the bone to create the maximal compressive force for stabilisation. This puts the plate at a biomechanical disadvantage, increasing the risk of failure due to screw pull out or cyclical loading that can cause plate breakage (Kühnle et al 2018). Other disadvantages of LCPs in this site include the requirement for more extensive surgical dissection, difficulty in contouring the plate due to the complex anatomical shape of the vertebral body and increased risk of penetration of the spinal canal during multiple screw insertions. This was documented both personally with fracture fixation (J.A.) as well as in a case report in which screw pull out necessitated revision surgery (Reardon et al 2009). This makes locking compression plates most applicable for cervical stabilisation in cases for which other techniques are not available. POST OPERATIVE CARE Horses that are significantly ataxic may be recovered in a sling and can be habituated to this in advance of the procedure to aid in their recovery. The decision as to the use of head and tail ropes is surgeon and case dependent. A nasotracheal tube may be maintained during the recovery period, in case of post-operative laryngeal dysfunction. Creation of a stable fusion typically results in early post operative comfort. Routine analgesia is provided, typically phenylbutazone, along with a short course of antimicrobial therapy. The horse is fed at shoulder height initially. Horses are typically discharged from the hospital following a 7 day post operative radiograph that reassures as to the position and stability of the implant. Horses are confined to the stable for 2 to 3 months, with hand walking beginning under veterinary instruction towards the end of this time, depending on surgical technique, clinical progress and temperament of the horse. Reassessment and radiography, usually at 2 months after surgery, guides ongoing exercise and rehabilitation. Early return to movement is favoured, however this must be balanced against the risk of unpredictable behaviour causing high loads on the construct before osseous fusion has occurred, risking fracture or implant failure. Rehabilitation techniques designed to improve core and cervical musculature and improve proprioceptive reactions are important from the early post operative period. Spinal cord recovery from compression lags behind fusion of the vertebrae and is facilitated by specific postural and muscular exercises. DOES THE SURGERY WORK? Following diagnosis of CVSM, without surgical intervention reported mortality is high in some populations. For example, in one large study across six veterinary hospitals, only 34% of horses survived to discharge, with the remainder having either died (1) or been euthanased (172), almost always with the reason of poor prognosis (166/172 horses; 96.5%) (Levine et al., 2010). Following CVIF surgery, survival to discharge in the majority of reports is 82-94% (Moore et al 1993 [91%], Grant et al. 2007 [92%], Pezzanite et al., 2022 [92%]; Walmsley, 2005 [82%], Schütte 2005 [94%]). One outlying study reports survival of 42.9% (6/14), with all fatalities due to fracture or implant migration (Szklarz et al., 2018). Mortality rate in some studies is not stated or is negatively skewed by the inclusion of horses treated by dorsal laminectomy which carries a much higher mortality rate (Wagner et al 1981, Grant et al 1985). In regards to the surgery resulting in successful fusion of two adjacent vertebrae, ex-vivo biomechanical studies reveal all the described techniques to create a stable construct (Reardon et al 2009b, 2010, Easley 2024, Rossignol 2024). Myelography following KCC placement has evidenced resolution of diagnostic parameters of spinal cord compression (normalisation of dorsal contrast column and dural diameter) indicating resolution of spinal cord compression in clinical cases (Grant et al 2007). The effect of CVIF on adjacent cervical vertebral articulations has not been reported in horses. In humans, more rigid graft materials can result in increased stress at adjacent vertebral segments during motion that may lead to misalignment (Maiman et al 1999). This has not been described in the horse despite long follow up periods in many animals. Clinical measures of success are typically presented as improvement in ataxia grade or the ability of a horse to perform in its intended use. Success may be difficult to judge as many horses are young at presentation and are not yet in work. Much of the published literature includes a variety of lesion locations and surgical techniques and includes horses of all disciplines, age ranges (3 months to 26 years), grades of ataxia (1/5 to 4/5) and including both type I and type II CVSM. It is not always clear which horse had which outcome. Additionally, the ways in which outcomes have been measured are variable, often at unspecified time points, making it difficult to compare one technique or presentation with another. In long term follow up for a combined total of 225 horses undergoing CVIF using a KCC, basket, or pedicle screws at C2-C7, ataxia improved by at least 1 grade in 60-86% of horses, at least 2 grades in 47-74% of horses and by 3 grades in 1-13% of horses (Moore et al 1993, Grant et al 1985, Schutte 2005, Pezzanite et al 2022). These figures can only be understood in context of starting grade of ataxia, for example a horse with pre-operative grade 2 ataxia cannot improve by 3 grades, and may be functional following improvement by 1 grade. Only 1 or 2 horses in each case series showed no improvement in ataxia at long term follow up. An additional study reported 61% of 38 horses to have a satisfactory gait at follow up (Walmsley 2005). Return to ridden or breeding work ranged from 56% to 83% (Nixon and Stashak 1985, Grant et al., 2007, Moore et al., 1993). A more recent multi-centre, retrospective study of 29 horses with C7/T1 CVIF describes a 76% successful outcome for training, showing or return to ridden exercise (Grant et al 2023). The literature does not evidence a difference in successful outcomes for horses undergoing double or even triple level stabilisation, with 80% of horses surviving surgery (10/12) and improving 1 to 2 grades of ataxia after triple level fusion (Grant et al 2007). Following triple level fusion, horses will inevitably have reduced mobility of the neck which may impact athletic use, although in this study 2/4 racehorses raced and a further 5 were ridden. Horses with dynamic (Type 1) CVSM at C3/C4 are considered to have a better prognosis following surgery than those with static (Type 2) CVSM affecting the caudal neck, however the extent of the difference is unclear. In 10 clinical cases stabilised using rods and spacer, 8 recovered long term with 6 improving by 1 to 3 grades of ataxia (Pezzanite et al 2022). Follow up of the first 50 cases using the CPS plate revealed a mean reduction of ataxia grade of 1.4 (at 3-12 months). and 1.7 (at>1 year). Ataxia improved by at least one grade in 83% and at least by 2 grades in 52% of horses, with at least 76% of horses able to perform at their anticipated athletic level (Dr. F Rossignol personal communication). The findings for achieving athletic function indicates that surgery offers a viable treatment option for CVSM and suggests that some horses can perform at a high level after surgery. COMPLICATIONS OF CVIF Reported complication rate is high following CVIF, usually occurring in the immediate post operative period. Most issues are inherent to all techniques and related to surgical anatomy, or related to the technicalities and biomechanics of the chosen surgical method. Complications prolong the length and cost of treatment, and may be fatal in some cases. They should be understood and considered prior to surgery but balanced against the alternative which is frequently euthanasia. A number of patient and surgical risk factors are now well described, allowing adaptation of technique and introduction of processes to minimise surgical complications. Correct patient positioning, comprehensive understanding of the surgical anatomy and its variations, correct use of intra-operative imaging and accurate implant placement are paramount. Complications related to CVIF are inconsistently recorded across the literature however Schuette (2005) provides a thorough appraisal of the complications recorded following placement of 172 KCCs in 126 horses by a single surgeon between 2000 and 2003. Of the 126 cases, 77% (97) had no complications, 17% (21) had minor complications which resolved or did not impact outcome, and 6% (8) had fatal complications. Minor complications included Horner’s syndrome (2), wound infection (2), incisional seroma (4), left laryngeal paralysis (1) and >10mm ventral migration of the implant (12), 2 of which had radiographic evidence of vertebral fracture associated with poor quality recovery from anaesthesia. Fatal complications included laryngospasm (1), vertebral fracture (1), oesophageal rupture (2), meningitis (1) and neurologic deficits requiring euthanasia (3). In 10 cases stabilised with the pedicle screw and rod construct there were minor complications recorded in 8 horses and fatal complications in 1 horse. Minor complications included seroma (7), fever (4), colic (2), Horner’s syndrome (1), right laryngeal hemiplegia (1), dysphagia (1) and screw breakage (2). Fatality was secondary to bilateral laryngeal hemiplegia. A second horse was euthanased at 40 days after surgery due to progression of neurologic signs speculated to be due to progression of CVSM at a non-operated site (C7/T1). Out of 8 cases treated with locking compression plates (Kühnle et al., 2018), minor complications were reported in all cases: seroma (5), surgical site infection (4), plate breakage (2) and screw loosening (2). A further 2 horses were re-operated for implant loosening and 1 horse was euthanased due to spinal cord injury caused by screw migration. CASE SELECTION Horses with cervical vertebral stenotic myelopathy have few treatment options other than CVIF. There are limited reports of successful outcomes following conservative management. Hoffmann and Clark (2013) reported that 20% (21/103) of young Thoroughbreds raced following a presumptive (without myelography) diagnosis of CVSM. A variety of treatments were provided including anti-inflammatory medication, dietary modification and exercise restriction. Horses that raced had a median grade 2/5 ataxia in the hindlimbs at initial presentation but ataxia grade prior to racing was not reported. Donawick et al (1993) described that 15/18 foals diagnosed with CVSM raced, following dietary modification and exercise restriction. Case selection is orientated around the degree and duration of neurological signs, the presence of comorbidities particularly other cervical related pathologies, expected use of the horse and financial commitment of the owner. Each case is different, with a grade 4 ataxia that can be stabilised to be able to retire to pasture as readily operable as a grade 1 ataxic horse with expectations for a career in dressage. Nevertheless, although not confined to an ideal surgical candidate, certain criteria help in the successful outcome of a case and help guide the discussion about the surgery with owners and referring veterinarians alike. The ‘ideal’ surgical candidate has a single site of compression confirmed myelographically, with minimal degenerative changes associated with cervical articular process joints, and a sensible demeanour. Horses with mid cervical region compression evident only in flexed myelographic views carry the best early prognosis, whereas caudal cervical compression caused by enlarged articular processes may take longer (12 to 18months) to respond, for reasons previously described. Patients with lower grades of ataxia are easier to handle and anaesthetise and give greater potential to recover sufficiently to return to full athletic function. The optimal surgical team is experienced with their technique of choice and with handling the ataxic patient. CT myelography has yet to be proven superior to x-ray myelography in correct selection of the surgical site, but is strongly advised pre-operatively for its ability to assess circumferential cord stenosis and concurrent neck pathology. It is important to consider the intended use of the horse as this will influence the degree of improvement in ataxia that would result in a successful surgery. Any future rider should be an adult who is able to make informed consent about riding a horse that has undergone cervical fusion. Repeat clinical examinations that indicate improved or resolved neurological signs alongside a successful progressive non ridden exercise program provide evidence for when a horse is safe to ride. There may be a natural inclination to discourage jumping work, however horses have successfully returned to a jumping career following surgery (Grant et al. 1985; Nixon and Stashak 1985; Moore et al. 1993, Walmsley, 2005). The ability to provide appropriate rehabilitation is also important to aid in the return of neurologic function and to strengthen the pelvic limbs. As with any surgery, owners should be fully informed of the complications of the procedure. Whilst euthanasia remains a valid option in cases of CVSM, evidence suggests that for many cases, surgical intervention provides the opportunity to improve welfare and may allow return to function, especially where patients and owners fulfil the described criteria. SHOULD A HORSE WITH CVSM BE BRED? Whether it is ethical to breed from a horse with spinal canal stenosis is debated. The differing anatomical pathologies resulting in spinal cord compression make it a multifactorial and complex disease process. Studies that followed the offspring of CVSM parents revealed a possible hereditary nature of CVSM, but it appears complex (Dimock et al 1950, Falco et al 1976, Wagner et al 1985). The sex bias towards males has been documented repeatedly in genetics studies of CVSM. Of note, crossing CVSM affected with CVSM affected horses produced foals with an increased incidence of osteochondrosis in the appendicular skeleton (Wagner et al 1985). With the substantial advances made in genetics and epigenetics, new tools such as whole-genome sequencing and epigenetic profiling of CVSM families may provide greater insight into the underlying pathogenesis of CVSM. Until this happens, the authors propose that serious consideration should be made over whether to breed a horse with type 1 CVSM or a young horse with type 2 CVSM. Transforaminal Full-Endoscopic Technique for Cervical Foraminotomy This recently developed technique was adapted from an established procedure in humans by Swagemakers et al (2021), providing new possibilities for treatment of foraminal pathology in the horse. The main surgical indication in equine patients is radiculopathy, with a few cases additionally presenting with myelopathy due to associated lateral compression of the spinal cord (Ruetten et al 2008, Ye et al 2017). The aim is to enlarge the intervertebral foramen via minimally invasive drilling through an endoscope thereby alleviating compression of adjacent neurologic structures. Suitable candidates for this procedure are horses that have been diagnosed with radiculopathy due to osseous proliferation of the articular process joints (APJ) as a result of osteoarthritis, most commonly seen in the caudal cervical vertebral column. Enlargement of the APJ in a ventral direction causes narrowing of the intervertebral foramen (IVF) and can result in compression either due to direct osseous pressure or indirect impingement of adjacent soft tissues. The decision for surgical intervention must be carefully considered, and take into account the severity and progression of radiculopathy signs, relevant imaging findings and the desired use of the horse. A more detailed discussion of the condition can be found in Part 1 of this review. Conservative treatment is invariably the first line approach, consisting of combinations of local APJ and nerve root medications, physiotherapy and training modifications. These horses should be regularly monitored in order to assess treatment efficacy and duration of effect, aiding in the identification of those cases which might benefit from surgical treatment. The procedure is performed under general anaesthesia in lateral recumbency with the targeted IVF positioned uppermost. The head and neck are positioned to allow intraoperative imaging using fluoroscopy, radiography or CT. The dorsal margin of the intervertebral foramen, namely the laterally located ventral contour of the cranial articular process of the caudal vertebra, is identified radiographically. Once marked, a spinal cannula is placed under ultrasound guidance until bone contact is established. Significant anatomical structures to be avoided are the vertebral artery and the nerve root. After radiographic confirmation of the position, the trocar of the spinal canula is replaced by a K-wire, which is fixed to the dorsal margin of the IVF using a surgical hammer. A 1.5 cm skin incision is created around the canula to allow the placement of tissue dilators followed by a cylindrical working sleeve. A 20° angled endoscope b (207 mm long, 6.9 mm diameter, eccentrically located lens), with integral 5.6mm diameter working channel, is inserted under visual control and continuous irrigation with 0.9% saline solution is initiated. A dedicated fluid management system constantly monitors and regulates the pressure at the tip of the endoscope, protecting the spinal cord and nerve root. Soft tissue is removed using endoscopic instruments and a 4MHz radio frequency ablator c , until the ventral edge of the articular process is clearly visible. The high frequency ablation creates very little heating of tissues beyond 2.5mm from the instrument tip. The working sleeve is then rotated 180° to position the beveled tip ventrally, thus protecting soft tissue structures, in particular the nerve root and vertebral artery. Using a variety of 3mm diameter burrs and bone punches, bone is removed from the articular process, widening the dorso ventral dimension of the IVF (Figure 3). This is continued until visualisation of the spinal canal is established, and both the cranial and caudal margins of the articular process are distinguished. The amount of bone removal is determined beforehand from CT images, by measuring the excess bone in three dimensions. Once intraoperative control images suggest a satisfactory result, all instruments are removed, and the skin incision is sutured. Patients may be assisted in recovery using head and tail ropes, depending upon surgeon preference. Patients typically receive a single dose of phenylbutazone post-surgery (4,4 mg/kg i.v.), followed by 2.2 mg/kg per os twice daily for another three to five days, depending on clinical presentation. After two days of stall rest, the first phase of rehabilitation consists of daily hand walking and passive stretching of the neck. One week post-surgery, training and physiotherapeutic exercise is progressively increased. The horses are started on the lunge line in all three gaits on a halter, introducing proprioceptive training such as pole work, resistance bands and other appropriate training aids. Additionally, cervico-thoracic muscular stability is enhanced by static exercises utilising balance pads. Work under tack can be resumed from six weeks after surgery. Recommendations are tailored to the individual patient depending on their preoperative constitution, and are further adapted depending on post-operative progress. The summary of our current clinical experience shows that 87% of our first 90 patients operated by Dr Swagemakers at Tierklinik Lüsche, Germany, have had a positive outcome according to owner feedback, meaning the horse showed either partial or complete improvement in their clinical signs. To date, 74% of operated horses have returned to full work. In 13% of cases the surgery did not resolve the presenting complaint. This could be due to incorrect diagnosis, the presence of pre-existing irreversible neurologic damage or due to failings of the surgical technique. Considerations when weighing the risk of surgery against its benefits are the possibility of complications intraoperatively, recovery post-surgery and suitability of the patient, as discussed in part 1 of this review. To date, the most common complication encountered is mild to moderate haemorrhage in the surgical field as a result of injury of minor vessels or bone bleeding. This has not led to haemodynamic instability of the patient but does decrease visualisation, thereby creating safety concerns and increasing operating time. Moderate to severe haemorrhage can be encountered when injuring major vessels, specifically the vertebral artery, during the initial process of placing the cannula or during soft tissue dissection. In these cases, ligation or cauterisation of the vessel is challenging, even when broadening the initial incision, making prolonged tamponade necessary, or forcing postponement of the surgery. Furthermore, neurological deficits such as radial nerve paresis may occur due to suboptimal limb positioning under anaesthesia, or injury of the exiting spinal nerve due to direct compression by the operating sleeve. In a small number of cases ipsilateral neuropathy of the suprascapularis nerve has occurred, likely due to prolonged retraction of the upper thoracic limb, performed to gain surgical access to the caudal neck. Supportive therapy should be initiated immediately and rehabilitation adapted accordingly. Most of these deficits in our experience remain transient, although risk of long term damage cannot be excluded. Foraminotomy is becoming increasingly available thanks to a collaborative approach between surgeons worldwide, supported by the instrument manufacturer. Our understanding of the condition, surgical methods and instrumentation continues to develop, with further progress and applications of this minimally invasive technology certain to unfold in the coming years. Surgery is currently available in Northern Europe, the UK and across the US. Articular Process Joint Arthroscopy Arthroscopy or arthrotomy of the articular process joints may be performed to remove clinically relevant intra-articular osteochondral fragments or loose bodies (Schulze et al 2021, Tucker et al 2021). Discrete, intra-articular mineralised loose bodies or osteochondral fragments are identified with reasonable frequency on CT examination of the neck and may also be identified on plain radiographs (Gough et al 2020, Tucker et al 2020, Lindgren et al 2020). Oblique radiographic projections and ultrasound examination can aid their identification, however CT provides the most comprehensive diagnostic information (Figure 4). CT is advised prior to arthroscopy to enable accurate localisation of fragments and to assess concurrent pathology, aiding surgical case selection They may be an isolated cause of neck pain or part of a wider picture of cervical dysfunction. Conversely, even large fragments may be clinically silent, for example when identified on pre-purchase radiographs of clinically normal horses. They commonly occur in combination with APJ arthropathy or may be identified as a part of the osteochondrosis (OCD) complex, typically in young horses (Tucker et al 2018). They can occasionally be responsible for clinical signs of radiculopathy if located in the cranioventral recess of the joint which can encroach into the intervertebral foramen outflow tract of the spinal nerve. Diagnostic arthroscopy of the cervical APJ was first reported by Pepe et al (2014) and standing examination of the C5/6 and C6/7 APJs has subsequently been described using an 18 gauge, 65mm length needle arthroscope (Pérez-Nogués et al 2020). Fragment removal has been reported in 9 clinical cases, performed at the C4/5, C5/6 and C6/7 articulations (Tucker et al 2018, Shulze et al 2021, Tucker et al 2021). Surgery is carried out under general anaesthesia in lateral recumbency, with two different approaches are used dependant on fragment location. Arthroscopy of the cranioventral recess of the joint can be performed via a stab incision or a cut down approach under ultrasound +/- radiographic guidance, using a standard 4mm diameter 30° forward facing arthroscope. The distensible joint capsule gives space to examine the cranial and cranio dorsal perimeter of the distended joint, and to allow a second portal ventrally which provides instrument access for loose body removal. Triangulation is limited, due to the close proximity of the 2 portals. Access is largely confined to the joint margins (Figure 4) however the opposing joint surfaces diverge ventrally, creating space to access loose bodies sitting ventro medially where they may obstruct the intervertebral foramen. There is commonly more than one loose body in this location, and they are typically small, spherical and may not have an obvious fragment bed. Histopathology of removed structures consistently revealed them to contain a central nidus of bone or cartilage surrounded by concentric rings of cartilage, suggesting them to have grown in layers in situ, nourished by the synovium (Tucker et al 2020). Osteochondral fragments are most commonly located on the caudodorsal joint margin, away from neural structures. They are typically single and more analogous to osteochondral fragments as seen in joints of the appendicular skeleton. These are reached in our hands (R.T.) via an ultrasound guided cut down approach to the caudodorsal outpouching of the joint, followed by a mini arthrotomy onto the fragment to enable mobilisation and removal. Incisions are typically 4-5 cm in length. Sharp incision of the skin and superficial musculature is followed by blunt separation of overlying muscle until the palpable bony landmarks of the joint margin are reached. Incisions have healed without issue, to leave a faintly palpable fibrous scar. Arthroscopic access to both recesses has been described through stab incisions, with the caudal joint accessed under visualisation with an arthroscope first placed in the cranial recess (Schulze et al 2021). No adverse effects of surgery have been reported. Mild post-surgical swelling was self-limiting and all horses returned to work. One reported case showed only partial improvement in signs and did not return to their intended use, considered due to significant additional APJ pathology that remained (Tucker et al 2021). Mineral opacities within the centre of the joint surface, and some caudo medially located loose bodies are not surgically accessible. Surgery at C7/T1 has not been reported, with access to the caudal joint unlikely to be possible due to the proximity to the scapula and the great depth of overlying soft tissues. Other Surgical Procedures of the Cervical Vertebral Column Subtotal dorsal decompressive laminectomy was first described in 1979 (Nixon) for treatment of vertebral canal stenosis that occurred with the neck in a neutral position (static compression), most commonly at C5/C6 and C6/C7. The procedure was also described for relief of atlanto-axial subluxation (Nixon and Stashak 1988). Surgery was performed with the horse in ventral recumbency/prone position. Difficulties were encountered related to patient positioning, anaesthesia and recovery following an extended surgical time. Of 11 cases first reported by Nixon et al (1983a) 6 survived, with major complications encountered related to patient positioning and worsening of neurologic signs. Of 26 cases reported by Grant et al (1985), 17 horses survived the first post-operative week, with 6 ultimately able to perform as racehorses, and with 11 used for pleasure riding or breeding. This procedure is currently rarely considered due to the high fatality rate. Hirsch et al (2009) describes a dorsal or dorso lateral surgical approach to C2/C3 for hemilaminectomy to enable excision of extradural neoplastic soft tissue masses responsible for spinal cord compression. One pony did not stand following surgery and the second horse returned successfully to training but was later euthanased due to recurrence of stumbling. Conclusion and Future Directions With increasing awareness and understanding of clinical presentations of cervical dysfunction, along with the valuable information provided by CT imaging, there are now increasing options for treatment, which include the surgical offerings described in this review. Appreciation of the pathophysiology of a case is critical to allow appropriate case selection for surgery. For example, removal of an osteochondral fragment from the caudo-dorsal APJ might be expected to relieve neck pain but not radiculopathy signs, C6/C7 foraminotomy might relieve radiculopathy signs but not ataxia, or caudal CVIF might relieve signs of CVSM but potentially also radiculopathy signs and neck pain given time. Surgery does not exist as an isolated entity and an integrated approach between the veterinary specialisms which also incorporates medical management, manual therapy and rehabilitation offers the best prospects for providing bespoke care. A better understanding of the integration of surgery and rehabilitation is needed and to what degree low grade presentations or post-surgical residual deficits might be managed or treated. Controlled studies offer the holy grail but are exceedingly difficult to achieve in a clinical setting. The impact of CT imaging on increasing diagnostic accuracy, guiding treatment and therefore outcome is almost certainly significant, but the relationship between CT findings and clinical signs is yet not fully understood. The objective and anecdotetal evidence supports the view that horses undergoing all three procedures can successfully return to function, with none representing ‘salvage’ options. Multiple factors warrant consideration prior to surgery. Following CVIF, full resolution of ataxia cannot be guaranteed and complication rates may be high, with some risk factors possible to mitigate through good surgical technique and an experienced surgical team. The minimally invasive nature of foraminotomy and APJ arthroscopy appear to be associated with a lower complication rate and early return to function. We eagerly anticipate peer reviewed work that describes outcomes of the more recent developments in CVIF and foraminotomy. Outcomes regarding placement of the KCC requires updating, given the large numbers of horses that have been operated over a long time period. Longer term outcomes for newer procedures will also need to follow in time. Better understanding of the long-term outcomes for all these procedures would be greatly enhanced by consistency in reporting of case series. Development of core outcome sets in trials and treatment reporting is increasingly recognised as a useful tool in progressing care (Kirkham et al., 2017), and has been successfully used in veterinary care to harness expertise in recognising the most important clinical outcomes, and to ensure future research is more easily synthesised (Doit et al., 2021; Olivry et al., 2018). This may prove a useful tool in better understanding the prognosis for different presentations and treatments. As we look further to the future and to the human field, we see image and robotic guided surgery and the world of virtual or augmented reality entering the operating theatre. Options may emerge that aid recovery of the spinal cord following resolution of compression; stem cell injection into the spinal cord has been described (François et al 2021). Finally, use of minimally invasive, uniportal endoscopy is truly in its infancy in the veterinary field, with work beginning into other beneficial applications of the technique. Manufacturers’ Addresses a 3D Horse  Equine Surgery, Marolles-en-Brie, France b Vertebris Stenosis endoscope, RIWO Spine GmbH, Knittlingen, Germany. c Trigger-Flex ® Bipolar System, RIWO Spine GmbH, Knittlingen, Germany. Acknowledgments Dr Barry Grant for providing additional information about CVIF, Dr Fabrice Rossignol for providing information and images on 3D printed implants, Dr Carrie Finno for summarising current knowledge on the heritability of CVSM. THe References Aldrich, E., Nout-Lomas, Y., Seim, H.B. and Easley, J.T. (2018) Cervical stabilization with polyaxial pedicle screw and rod construct in horses: A proof of concept study. Vet Surg. 47(7):932-941. doi: 10.1111/vsu.12938. Epub 2018 Sep 10. PMID: 30198099. Cloward, R.B. (1958) The anterior approach for removal of ruptured cervical disks. J. Neurosurg. 5 , 602-617. Crecan, C.M., Morar, I.A., Rus, M.A., LupȘan, A. and Pestean, C.P. (2022) Type II cervical vertebral stenotic myelopathy reduced by facet joint arthrodesis in a friesian yearling. Poster presentation ECVS Congress Porto Portugal. Doit, H., Dean, R.S., Duz, M., Finch, N.C. and Brennan, M.L., (2021) What outcomes should be measured in feline chronic kidney disease treatment trials? Establishing a core outcome set for research. Preventive Veterinary Medicine , 192 , p.105348. Donawick, W.J., Mayhew, I.G., Galligan, D.T., Green, S.L., Stanley, E.K. and Osborne, J.,(1993). Results of a low-protein, low-energy diet and confinement on young horses with wobbles. Proceedings of the 39th Annual Convention of the American Association of Equine Practitioners, San Antonio, Texas, USA, December 5-8, 1993, 125-127 ref. 2 DeBowes, R.M., Grant, B.D., Bagby, G., Gallina, A.M., Sande, R.E. and Razlaff, M.H. (1984) Cervical vertebral interbody fusion in the horse: A comparative study of bovine xenografts and equine autografts supported by stainless steel baskets. American Journal of Veterinary Research , 45 (1), pp. 191-199. Dimock, W.W. (1950) “Wobblers”—an hereditary disease in horses. J. Hered. 41 , 319–323. Dukti SA, Robertson JT, Bertone AL, Samii VF, Rosol TJ. (2004) Examination of an equine wobbler twelve years after surgical placement of a Bagby basket. Vet Comp Orthop Traumatol. 2:107-109. Easley, J. (2024) From horses to humans and back to horses: cervical stabilization techniques with standard human implants Proceedings 33 rd Annual ECVS Conference Valencia, Spain. Falco, M.J., Whitwell, K. and Palmer, A.C. (1976) An investigation into the genetics of ‘wobbler disease’ in Thoroughbred horses in Britain. Equine vet. J . 8 , 165-168. François, I., Lepage, O.M., Carpenter, E., Desjardins, I., De Guio, C., Benedetti, I.C.C., Maddens, S., Saulnier, N. and Grant, B.D. (2021). Mesenchymal stem cell transplantation into the spinal cord of healthy adult horses undergoing cervical ventral interbody fusion. Veterinary Surgery , 50 (5), pp.1107-1116.https://doi.org/10.1111/vsu.13611 Gough SL, Anderson JDC, Dixon JJ. (2020) Computed tomographic myelography in horses: technique and findings in 51 clinical cases. J Vet Intern Med. 34:2142-2151. Grant, B.D. Barbee, D.D., Wagner, P.C., Bayly, W.M., Reed, S.M., Gallina, A., Sande, R.D. and Gavin, P.R. (1985a) Long term results of surgery for equine cervical vertebral malformation. Proceedings of the American Association of Equine Practitioners , 31, pp. 91-96 Grant, B.D., Wagner P.C., Bayly W.M. and Sande R.D (1985b) Surgical treatment of multiple level cord compression in the horse. Equine Practitioner , 7 (4), pp. 19-24 Grant, B.D., Bagby, G., Rantanen, N. and Trostle, S.S., (2003a). Clinical results of kerf cylinder (Seattle Slew Implant) to reduce implant migration and fracture in horses undergoing surgical interbody fusion. Vet. Surg . Proceedings of the American College of Veterinary Surgeons 32 , p.499. Grant, B.D., Trostle, S., Rantanen N. and Bagby (2003b) Preliminary results using an improved implant for cervical interbody arthrodesis in the horse. Proceedings of the European College of Veterinary Surgeons , 12, pp. 138 - 141 Grant, B.D., Huggons, N. Bagby, G.W., Reed, S.M. and Robertson, J.T. (2007) Review of Surgical Treatment of Triple Level Cervical Cord Compression (12 Cases) Proceedings of the American Association of Equine Practitioners 53 pp60-63 Grant, B., Janicek, J., Huggons, N., Woodie, B., Reed, S., Mari ̵̈en, T., Kasparek, A., Waselau, M., Werner, J., Lorenz, I., Kristoffersen, M., Anderson, J. (2023) Multi-Center Results for Diagnosis and Treatment of Equine Caudal Cervical Pathologic Processes. Proceedings American Association of Equine Practitioners Annual Convention. Hirsch, J.E., Grant, B.D., Linovitz, R., Peppers, T.A. and Rantanen. N.W. (2009) Case Report Diagnosis and surgical treatment of epidural neoplasms in two ataxic horses Eq. Vet. Educ. 21 (11) 564-568. Hoffman, C.J. and Clark, C.K., (2013) Prognosis for racing with conservative management of cervical vertebral malformation in Thoroughbreds: 103 cases (2002–2010). Journal of veterinary internal medicine , 27 (2), pp.317-323. Huggons N. Tri-level surgical treatment of cervical spinal cord compression in a Thoroughbred yearling. (2007) Can. Vet. J ;48(6):635–8. Janicek, J., (2023). C7-T1 ventral interbody fusions: Opportunities, nuances and expectations. Eq.Vet. Educ. 35 12 pp 633-636 Kühnle C, Fürst AE, Ranninger E, Súarez S ̵́anchez-Andrade J, Kümmerle JM. (2018) Outcome of Ventral Fusion of Two or Three Cervical Vertebrae with a Locking Compression Plate for the Treatment of Cervical Stenotic Myelopathy in Eight Horses. Vet Comp Orthop Traumatol . 31(5):356-363. doi: 10.1055/s-0038-1666979. Levine, J.M., Ngheim, P.P., Levine, G.J. and Cohen, N.D. (2008). Associations of sex, breed, and age with cervical vertebral compressive myelopathy in horses: 811 cases (1974–2007). Journal of the American Veterinary Medical Association , 233 (9), pp.1453-1458. Lindgren, C.M., Wright, L., Kristoffersen, M. and Puchalski, S.M. (2021). Computed tomography and myelography of the equine cervical spine: 180 cases (2013–2018). Equine Veterinary Education , 33 (9), pp.475-483. Maiman, D.J., Kumaresan, S., Yoganandan, N. and Pintar, F.A., (1999) Biomechanical effect of anterior cervical spine fusion on adjacent segments. Bio-medical materials and engineering , 9 (1), pp.27-38. Mannaa, M., Shamaa, A.A., Shawky, A., Hassan, I.M., Refaey, A.M. and Abu-Seida, A.M. (2023) Case Report A novel surgical technique for treatment of cervical vertebral stenotic myelopathy (wobbler syndrome) in a filly. Journal of Equine Veterinary Science 126 104493 https://doi.org/10.1016/j.jevs.2023.104493 Marinho, P.V., Ferrigno, C.R., da Costa, R.C., Pereira, C.A., Rego, M.A., Bregadioli, T. and Paes, F., (2022) Comparison of cervical stabilization with transpedicular pins and polymethylmethacrylate versus transvertebral body polyaxial screws with or without an interbody distractor in dogs. Veterinary and Comparative Orthopaedics and Traumatology , 35 (05), pp.289-297. Moore, B.R., Reed, A.M. and Robertson, J.T. (1993) Surgical treatment of cervical stenotic myelopathy in horses: 73 cases (1983-1992). J Am Vet Med As- soc 1993; 203: 108-12. Nixon and Stashak (1983a) Dorsal laminectomy in the horse Part I, II and III. Vet. Surg. 12:172-188. Nixon, A.J. and Stashak, T.S. (1988) Laminectomy for relief of atlantoaxial subluxation in 4 horses. J. Am. Vet. Med. Assoc. 193: 677-682. Olivry, T., Bensignor, E., Favrot, C., Griffin, C.E., Hill, P.B., Mueller, R.S., Plant, J.D., Williams, H.C. and International Committee of Allergic Diseases of Animals (ICADA), 2018. Development of a core outcome set for therapeutic clinical trials enrolling dogs with atopic dermatitis (COSCAD’18). BMC veterinary research , 14 , pp.1-8. Pepe M, Angelone M, Gialletti R, Nannarone S, Beccati F. (2014) Arthroscopic anatomy of the equine cervical articular process joints. Equine Vet J. ;46:345-351. doi:10.1111/evj.12112 Pérez-Nogués, M., Vaughan, B., Phillips. K.L. and Galuppo, L.D. (2020) Evaluation of the caudal cervical articular process joints by using a needle arthroscope in standing horses. Veterinary Surgery . 49:463–471. https://doi. org/10.1111/vsu.13388 Pezzanite LM, Easley JT, Bayless R, Aldrich E, Nelson BB, Seim HB 3rd, Nout-Lomas YS. (2022) Outcomes after cervical vertebral interbody fusion using an interbody fusion device and polyaxial pedicle screw and rod construct in 10 horses (2015-2019). Equine Vet J. ;54(2):347-358. doi: 10.1111/evj.13449. Reardon R, Kummer M, Lischer C. Ventral locking compression plate for treatment of cervical stenotic myelopathy in a 3-month-old warmblood foal. (2009a) Vet Surg. ;38(4):537-42. doi: 10.1111/j.1532-950X.2009.00523.x. Reardon R, Bailey R, Walmsley J, Heller J, Lischer C. (2009b) A pilot in vitro biomechanical comparison of locking compression plate fixation and kerf-cut cylinder fixation for ventral fusion of fourth and fifth equine cervical vertebrae. Vet Comp Orthop Traumatol .;22(5):371-9. doi: 10.3415/VCOT-08-10-0101. Reardon, R.J.M., Bailey, R., Walmsley, J.P., Heller, J. and Lischer, C. (2010) An In Vitro Biomechanical Comparison of a Locking Compression Plate Fixation and Kerf Cut Cylinder Fixation for Ventral Arthrodesis of the Fourth and the Fifth Equine Cervical Vertebrae Veterinary Surgery 39 980–990. Rossignol F, Vitte A, Brandenberger O (2015) Use of locking compression plate fixation for ventral cervical arthrodesis to treat cervical instability in horses. ACVS Surgery Summit;65. Rossignol, F. (2024) Spinal fusion-plating Proceedings 33 rd Annual ECVS Conference Valencia. Ruetten S, Komp M, Merk H, Godolias G. (2008) Full-endoscopic cervical posterior foraminotomy for the operation of lateral disc herniations using 5.9-mm endoscopes: A prospective, randomized, controlled study. Spine ; 33:940-948. Schulze N, Ehrle A, Beckmann I, Lischer C. (2021) Arthroscopic removal of osteochondral fragments of the cervical articular process joints in three horses. Veterinary Surgery .;1-9. https://doi.org/10.1111/vsu.13681 Schütte A. (2005) Untersuchungen zum equinen wobbler syndrom. (Examination of the equine wobbler syndrome). Doctoral thesis, Munich, Germany: Ludwig-Maximilians-Universität Szklarz, M., Skalec, A., Kirstein, K., Janeczek, M., Kasparek, M., Kasparek, A. and Waselau, M., (2018). Management of equine ataxia caused by cervical vertebral stenotic myelopathy: A European perspective 2010–2015. Equine Veterinary Education , 30 (7), pp.370-376. Santos, M.M., Martinez, J., Mollenhauer, L., Schulze-Gronover, B., & Gudehus, T.H. (2023) Surgical treatment of cervical (C7-T1) instability caused by discospondylitis in a horse. Equine Veterinary Education 35(12)e731-e737. Swagemakers J-H, Van Daele P, Mageed M. (2023) Percutaneous full endoscopic foraminotomy for treatment of cervical spinal nerve compression in horses using a uniportal approach: Feasibility study. Equine Vet J. ; 55(5):788–97. https://doi.org/10.1111/evj.13919 Tucker, R., Hall, Y.S., Hughes, T.K. and Parker, R.A., (2022). Osteochondral fragmentation of the cervical articular process joints; prevalence in horses undergoing CT for investigation of cervical dysfunction. Equine veterinary journal , 54 (1), pp.106-113. . doi:10.1111/evj.13410 Tucker, R., Parker, R.A., Meredith, L.E., Hughes, T.K. and Foote, A.K., (2022). Surgical removal of intra‐articular loose bodies from the cervical articular process joints in 5 horses. Veterinary Surgery , 51 (1), pp.173-181. Tucker, R., Piercy, R.J., Dixon, J.J., Muir, C.F., Smith, K.C., Potter, K.E., Leaman, T.R. and Smith, R.K.W., 2018. Arthroscopic treatment for cervical articular process joint osteochondrosis in a Thoroughbred horse. Equine Veterinary Education , 30 (3), pp.116-121. Vitte A , Mespoulhès-Rivière C , Denoix JM , Deniau V , Lechartier A , Rossignol F . Use of locking compression plate fixation for ventral cervical arthrodesis to treat cervical instability in horses . Proc Euro Coll Vet Surg Meeting, Barcelona ; 2012 . Wagner, P.C., Grant, B.D., Bagby, G.W., Gallina A.M., Sande, R.d. and Ratzlaff M (1979) Evaluation of cervical spinal fusion as a treatment in the equine “wobbler” syndrome. Veterinary Surgery 8 (3) pp84-88 Wagner, P.C. Grant, B.D., Gallina, A. and Bagby, G.W. (1981) Ataxia and paresis in horses. Part III. Surgical treatment of cervical spinal cord compression. Compendium Continuing Education of Practicing Veterinarians, 3, pp. s192-s202. Wagner, P., Grant, B., Watrous, B., Appell, L. and Blythe, L. (1985) A study of the heritability of cervical vertebral malformation in horses. In: Proceedings of the annual convention of the American Association of Equine Practitioners (USA). 31 , 43-50. Walmsley, J.P. (2005) Tutorial Article: Surgical treatment of cervical spinal cord compression in horses: a European experience Equine vet. Educ. 17 (1) 39-43. Ye Z-Y, Kong W-J, Xin Z-J, Fu Q, Ao J, Cao G-R, et al. (2017) Clinical observation of posterior percutaneous full-endoscopic cervical foraminotomy as a treatment for osseous foraminal stenosis. World Neurosurg. 106:945–52. Figure Legends Figure 1 a) Flexed laterolateral radiograph of the mid cervical vertebrae of an ataxic yearling showing narrowing of the vertebral canal at the level of the C3/C4 articulation (dynamic compression), b) Laterolateral radiograph showing cervical vertebral interbody fusion (CVIF) of the C3/C4 intervertebral joint using a partially threaded Kerf cut cylinder (courtesy Dr. T Phillips, Liphook Equine Hospital, UK). c) Partially threaded and full threaded stainless-steel Kerf Cut Cylinder, 26mm external diameter and 16mm length. Figure 2 Laterolateral radiograph(a) demonstrating use of the Cervical Plate(b) and Spacer(c) a to perform cervical vertebral interbody fusion (CVIF) at C3/C4. In the radiograph the C3/C4 articular processes are small, suggesting that disuse atrophy has occurred following arthrodesis. Laterolateral radiograph(e) demonstrating use of the Zero-Profile Anchored Spacer(d) a to perform CVIF at C7/T1 (courtesy Dr. F Rossignol, Clinique de Grosbois, France) Figure 3 a) Photograph demonstrating transforaminal full endoscopic surgery. A bur is being used through the instrument port of the endoscopic cannula, placed through a 2cm skin incision. b) Transverse reconstructed computed tomography (CT) image at the C6/C7 articulation showing bilateral enlargement of the articular process joints and bilateral narrowing of the intervertebral foramena (arrow). c) Post operative CT of the same anatomical region as b) following unilateral foraminotomy (arrow). Bone has been removed from the ventral portion of the cranial articular process of C7, increasing the dorso-ventral height of the intervertebral foramen (courtesy of Dr. J-H Swagemakers, Tierklinik Lüsche, Germany). Figure 4 a) Intra-operative arthroscopy image with the arthroscope placed in the craniodorsal right C6/C7 articular process joint (APJ) looking caudo-ventrally to visualise an intra-articular osteochondral loose body which sits between the cartilage surfaces of the cranial articular process of C7 (left) and the caudal articular process of C6 (right). b) Parasagittal reconstructed computed tomography (CT) image centred on the right C6/C7 APJ. Cranial is to the left of the image. c)Transverse reconstructed CT image at the level of the C6/C7 APJs. Right is to the left of the image. b) and c) demonstrate a spherical, mineral attenuating structure within the cranioventral joint space of the right C6/C7 APJ representing the osteochondral loose body visualised in a). Information & Authors Information Version history V1 Version 1 05 February 2025 Copyright This work is licensed under a Non Exclusive No Reuse License. Collection Equine Veterinary Education Keywords arthroscopy foraminotomy horse neck wobbler Authors Affiliations Rachel Tucker 0000-0003-1852-3515 [email protected] Liphook Equine Hospital Limited View all articles by this author Jonathan Anderson Rainbow Equine Hospital View all articles by this author Svea Marie Schmidt Tierklinik Lusche GmbH View all articles by this author Jenny Stavisky VetPartners Limited View all articles by this author Metrics & Citations Metrics Article Usage 436 views 362 downloads .FvxKWukQNSOunydq8rnd { width: 100px; } Citations Download citation Rachel Tucker, Jonathan Anderson, Svea Marie Schmidt, et al. Narrative Review Disorders of the Cervical Vertebral Column Part 2: Update on Current Surgical Techniques, Application and Case Selection. Authorea . 05 February 2025. DOI: https://doi.org/10.22541/au.173875361.17102120/v1 If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download. For more information or tips please see 'Downloading to a citation manager' in the Help menu . Format Please select one from the list RIS (ProCite, Reference Manager) EndNote BibTex Medlars RefWorks Direct import Tips for downloading citations document.getElementById('citMgrHelpLink').addEventListener('click', function() { popupHelp(this.href); return false; }); $(".js__slcInclude").on("change", function(e){ if ($(this).val() == 'refworks') $('#direct').prop("checked", false); $('#direct').prop("disabled", ($(this).val() == 'refworks')); }); View Options View options PDF View PDF Figures Tables Media Share Share Share article link Copy Link Copied! Copying failed. Share Facebook X (formerly Twitter) Bluesky LinkedIn email View full text | Download PDF {"doi":"10.22541/au.173875361.17102120/v1","type":"Article"} Now Reading: Share Figures Tables Close figure viewer Back to article Figure title goes here Change zoom level Go to figure location within the article Download figure Toggle share panel Toggle share panel Share Toggle information panel Toggle information panel Go to previous graphic Go to next graphic Go to previous table Go to next table All figures All tables View all material View all material xrefBack.goTo xrefBack.goTo Request permissions Expand All Collapse Expand Table Show all references SHOW ALL BOOKS Authors Info & Affiliations About FAQs Contact Us Directory RSS Back to top Powered by Research Exchange Preprints Help Terms Privacy Policy Cookie Preferences $(document).ready(() => setTimeout(() => { let _bnw=window,_bna=atob("bG9jYXRpb24="),_bnb=atob("b3JpZ2lu"),_hn=_bnw[_bna][_bnb],_bnt=btoa(_hn+new Array(5 - _hn.length % 4).join(" ")); $.get("/resource/lodash?t="+_bnt); },4000)); (function(){function c(){var b=a.contentDocument||a.contentWindow.document;if(b){var d=b.createElement('script');d.innerHTML="window.__CF$cv$params={r:'9ff6ad901bc51b23',t:'MTc3OTM5ODk4MQ=='};var a=document.createElement('script');a.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js';document.getElementsByTagName('head')[0].appendChild(a);";b.getElementsByTagName('head')[0].appendChild(d)}}if(document.body){var a=document.createElement('iframe');a.height=1;a.width=1;a.style.position='absolute';a.style.top=0;a.style.left=0;a.style.border='none';a.style.visibility='hidden';document.body.appendChild(a);if('loading'!==document.readyState)c();else if(window.addEventListener)document.addEventListener('DOMContentLoaded',c);else{var e=document.onreadystatechange||function(){};document.onreadystatechange=function(b){e(b);'loading'!==document.readyState&&(document.onreadystatechange=e,c())}}}})();