Standing Arthroscopic Treatment of Temporomandibular Joint Sepsis in a Horse

Long-Term Outcome of Horses Undergoing Unilateral Mandibular Condylectomy and Meniscectomy for Temporomandibular Joint Disease

Background

There are no reports describing the long-term outcome of sport horses undergoing unilateral mandibular condylectomy with meniscectomy (UMC) for treatment for severe temporomandibular joint (TMJ) disease (TMD). Whether horses undergoing UMC require a specialized diet, can return to riding with a bit, or return to intended function after surgery is unknown.

Objective

To determine the long-term outcome of horses undergoing UMC for treatment of severe TMD.

Study Design

A multi-institutional, retrospective study.

Methods

Medical records obtained from seven equine referral hospitals of horses with severe TMD that underwent UMC were reviewed. Details regarding the presenting complaints, results of clinical examination, findings of diagnostic imaging, surgical technique, and outcome (including long-term follow-up with an owner questionnaire) were recorded.

Results

Eleven horses fit the inclusion criteria. Three had severe idiopathic osteoarthritis, and eight had confirmed septic osteoarthritis of the TMJ. The most common post-operative complications were drainage and peri-incisional swelling (n = 5). One horse developed a hematoma at the surgical site because the facial artery was inadvertently transected during the approach, causing the condylectomy to be postponed. All horses were discharged alive from the hospital, and 10 returned to their previous or intended use. All had complete resolution of clinical signs of TMD. One mare was retired from athletic use due to her genetic value as a broodmare. One horse was euthanized 2 years after UMC due to progressively worsening of clinical signs of temporohyoid osteoarthropathy (THO), which were not present before surgery. When available, owner satisfaction of the results of the procedure was excellent.

Main Limitations

Sample size; multiple institutions; owner bias.

Conclusions

Unilateral mandibular condylectomy should not be considered a salvage procedure. Horses treated for severe TMD by UMC can return to their previous or intended level of athletic performance and do not require a specialized diet.

The Equine Temporomandibular Joint: Comparisons Between Standard and Needle Arthroscopic Examination of Cadaver Specimens and Standing Horses

Background

Definitive diagnosis of equine temporomandibular joint osteoarthritis (TMJ-OA) may require advanced diagnostic imaging. Arthroscopy is a modern, minimally invasive, diagnostic, and treatment modality. Standing arthroscopic treatment of joint disease is a relatively recent advance in equine surgery, despite which there are few published comparisons between the available arthroscopic systems.

Objective

To compare and contrast two arthroscopic systems for assessing the equine temporomandibular joint compartments in cadavers and standing horses.

Study design

Experimental study.

Methods

Phase I involved the assessment of the discotemporal joint (DTJ) and discomandibular (DMJ) joint compartments of both temporomandibular joints (TMJ) of 14 cadaveric equine heads using a caudally placed arthroscopy portal. Joints were initially examined using the needle arthroscope and the results compared to the findings of examination using a 2.5 mm 30° arthroscope system (standard). Three healthy horses were subsequently examined to determine the validity of the procedure in live animals in Phase II.

Results

Needle and standard arthroscopy, in combination with mandibular manipulation, allowed evaluation of the caudal aspects of both joint compartments of the TMJ in Phase I. However, the extreme margins of the joint were more commonly visualized using standard arthroscopy. Live horses in phase II were restrained in stocks and both the rostral and caudal aspects of the DTJ and DMJ compartments of both TMJs were examined successfully understanding sedation and local analgesia. The use of a modified Guenther speculum allowed the mandible to be manipulated and offset, which facilitated a complete examination of the joint compartments. Despite adverse behavior encountered during the procedure in one horse, no surgical complications ensued.

Main Limitations

Not blinded-bias; learning curve.

Conclusions

The needle arthroscope system is a relatively inexpensive diagnostic tool, which can be used to evaluate the TMJ in the absence of advanced diagnostic imaging such as computed tomography or magnetic resonance imaging. However, if arthroscopic treatment is required after advanced imaging and pre-operative diagnosis, superior image quality and ease of manipulation may favor the use of the standard equipment.

Computed tomographic features of the temporomandibular joint in 10 Jeju horses

Background

Objectives

Methods

Results

Conclusions

Efficacy Evaluation of Temporomandibular Arthroscopic-Assisted Masseter Nerve Avulsion on Hemimasticatory Spasm

PURPOSE

Hemimasticatory spasm (HMS) is a masticatory muscle disorder without an effective treatment approach at present. This retrospective analysis aims to investigate the clinical efficacy of temporomandibular arthroscope-assisted masseteric nerve avulsion on HMS and thereby further determine a more effective therapeutic strategy for HMS patients.

METHODS

Four patients with HMS receiving temporomandibular arthroscope-assisted masseteric nerve avulsion in the neurology department of oral surgery of our hospital from April 2017 to April 2018 were recruited in this study. Through a clinical follow-up period of 36 months, the comprehensive efficacy of arthroscope-assisted masseteric nerve avulsion was evaluated combined with an electrophysiological electromyogram. Furthermore, the maximum muscle strength and masticatory efficiency of the sound and affected sides were measured to determine whether there were complications. The morphology of the myelin sheath of the masseteric nerve avulsed in the operation was observed under the transmission electron microscope.

RESULTS

The 3 years of follow-up showed that complete remission of HMS was seen in 4 patients with the score reduced to grade 0, showing satisfactory clinical efficacy. Electrophysiological electromyogram demonstrated an absence of obvious high-frequency group discharge potential in the 4 patients within 3 years after the operation, and the overall efficacy combined with the clinical efficacy was considered satisfactory. The maximum masseter strength of the sound side had no significant change, but that of the affected side was slightly decreased. The masticatory efficiency of the affected side was slightly decreased immediately after the operation but returned to the preoperative level 1 year after the operation, suggesting that this operation did not affect the masticatory function of the patients. No obvious demyelination was found in the avulsed nervous tissues.

CONCLUSIONS

Temporomandibular arthroscope-assisted masseteric nerve avulsion yielded satisfactory and stable overall efficacy on the treatment of HMS. The masticatory efficiency of the affected side was optimally preserved, while the maximum masseter muscle strength of the affected side was partially decreased.

Management of Septic Arthritis of the Temporomandibular Joint in Dogs

Septic arthritis of the temporomandibular joint (TMJ) in dogs and other mammals is a rare condition. It is typically associated with notable pain, swelling, and difficulty in opening the mouth. Unlike degenerative TMJ disease, septic arthritis requires urgent intervention. The etiology of the condition may include penetrating trauma, an extension of local infection, such as otitis media, or the hematogenous spread of a pathogen. However, the precise cause may not always be identified. Diagnostic imaging with Computed Tomography (CT), cone-beam CT (CBCT), and/or Magnetic Resonance Imaging (MRI) are helpful for honing the definitive diagnosis and formulating a treatment plan. Subsequently, exploratory surgery may be required to obtain samples for culture and sensitivity and histology and to lavage the joint. In this “methods” article, we provide a detailed description of our approach to diagnosis and management of septic TMJ arthritis in four dogs.