section epub:type=”chapter” role=”doc-chapter”> Fred Pike The clinical challenges of arthrodesis in companion surgery are varied and include limited regional bone stock for fixation and the periarticular geometry that complicates the contouring of bone plates. Additionally, the postoperative period can be challenging for patients and clients due to extensive limitations on mobility and prolonged need for coaptation that is generally recommended following arthrodesis when using nonlocking plate fixation (nLPF). The author’s clinical experience advocates that the use of locking plate fixation (LPF) can reduce many of the technical challenges associated with arthrodesis, reduce patient postoperative limitations, and decrease the duration of, or eliminate the need for, postoperative coaptation. Indications for arthrodesis in companion animals are numerous and include end‐stage osteoarthrosis, irreparable global ligament damage, congenital or traumatic joint luxation and loss of structural integrity of a joint. The general principals of arthrodesis, regardless of fixation method, include (i) removal of weight‐bearing articular cartilage with surgical instrumentation; (ii) preservation of functional joint angle; (iii) bone grafting to expedite callus formation and promote bone union; (iv) rigid fixation with compression of the joint surfaces. The majority of described techniques and clinical outcomes for arthrodesis in the veterinary literature are limited to the tarsus and carpus with less information available on shoulder, elbow and stifle arthrodesis outcomes. Prospective and retrospective studies directly comparing outcomes of LPF and nLPF are nonexistent. The use of LPF in human arthrodesis’ (specifically tibiotalocalcaneal and metatarsocuneiform) reduces surgical time, decreases intraoperative blood loss and reduces the number of postoperative surgical visits [1, 2]). With the increasing utilization of LPF in veterinary medicine, publication of more peer‐reviewed literature comparing clinical outcomes with the use LPF to nLPF is anticipated. Glenohumeral arthrodesis is indicated for the surgical management of congenital or traumatic luxation and end‐stage osteoarthrosis. Glenohumeral arthrodesis is an alternative to glenoid or humeral excisional arthroplasty. Functional outcomes are reported as fair to excellent [3]. The recommended angle for functional limb alignment is 110° [4]. Glenohumeral arthrodesis is technically demanding, with preservation of limb alignment a primary challenge. Limited bone stock proximal to the glenoid and the transitioning contour of the greater tubercle present major technical challenges. The use of LPF can address such concerns by limiting the need for precise plate contouring and eliminating the need for maximizing direct periosteal contact that would be required with nLPF. The author’s preference for glenohumeral arthrodesis is the use of the polyaxial (PAX) plating system for fixation, particularly for the scapula, where the ability for screw angulation with this system allows for maximum bone purchase. Fixation is applied following a craniolateral approach to the glenohumeral joint and following debridement of the articular cartilage. A tibial plateau leveling osteotomy (TPLO) saw blade of appropriate radius can facilitate removal of the articular cartilage and improve cancellous bone contact at the arthrodesis site. The curvature of the saw blade mirrors the natural contour of the articular surface in the transverse (lateromedial) plane, allowing maintenance of the shape of the glenoid and humeral head. Osteotomy of the acromion is not required. Maximizing the working length of the locking plates (LP) is critical to reduce the risk of stress concentration and plate fatigue at the level of the site of the primary arthrodesis. With the use of LPF, interfragmentary compression (lag screw or tension band fixation) is not a necessity. Intramedullary pins or Kirschner wires are helpful to provide temporary reduction prior to plate fixation (Figure 23.1). In the author’s experience, elbow arthrodesis is technically demanding with a high complication rate experienced with nLPF techniques. Fortunately, recent advances in minimally invasive orthopedic surgery, prosthetics ligaments and subcortical bone anchors have decreased the need for elbow arthrodesis to complex, non‐reconstructible articular fractures of the elbow, severe end‐stage osteoarthritis and failed elbow replacements may necessitate arthrodesis. The principles of arthrodesis outlined above are critical for successful elbow arthrodesis. The recommended angle for functional limb alignment is 110° [4].
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Arthrodesis
23.1 Shoulder Arthrodesis
23.2 Elbow Arthrodesis