Reconstruction of Collateral Ligaments

Collateral ligament injuries are common in small animal patients. Traumatic injuries can result in tears of the ligaments, avulsions of ligament origins/insertions, or loss of ligaments from shearing injuries. Torn collateral ligaments are often sutured for primary reconstruction; however, due to the slow healing and remodeling of collateral ligament tears, it is common to utilize sutures and anchors to support a primary repair. Placing a suture anchor at origin and insertion of the collateral ligament and spanning the two anchors with a relatively strong strand of suture material is a typical method of supporting primary ligament repair. Collateral ligament avulsions are repaired by placing a single suture anchor at the avulsion site and then reattaching the ligament to the bone via the anchor. Some surgeons will elect to include a second anchor and suture loop to create a prosthetic ligament to protect the avulsion site during the early healing phase (similar to protection of a primary repair). Injuries, such as shearing injuries, resulting in actual loss of the collateral ligament, carry a more guarded prognosis. However, suture anchors can be utilized to facilitate placement of prosthetic ligaments that serve to maintain joint stability during the formation of functional fibrous tissue, which helps maintain joint stability over time.

Stabilization of Shoulder Subluxation and Luxation

Primary, traumatic luxation of the shoulder joint is uncommon in small animal practice, but can occur. Congenital and developmental shoulder subluxation and luxation occur in small breed dogs and chronic shoulder instability occurs in large breed, athletic dogs. Surgical stabilization for these cases can include joint capsule imbrication and prosthetic suture placement to provide reduction and strength for supporting tissue healing and strengthening of the rotator cuff. Suture anchors can be utilized for attaching these periarticular sutures. Anchors can also be used for reattaching avulsed joint capsules or glenumeral ligaments to bone.

  • Reconstruction of Collateral Ligaments  

  • Stabilization of Shoulder Subluxation and Luxation 

Joint Capsule Reattachment 

With traumatic joint luxations, the joint capsule is always torn to some degree and re-establishing its integrity and function is a primary goal of treatment. In some cases, the damage to the joint capsule is in the form of avulsion from the bone. In these cases, reattachment of the joint capsule to the bone increases the mechanical stability of the repair and may lead to more rapid return to function. Use of anchors in this fashion greatly facilitates re-attachment of the avulsed joint capsule by allowing the exact number of anchor points to be utilized. In comparison to more mechanically demanding scenarios, relatively small suture materials can be utilized for joint capsule reattachment. The photo below shows a reduced elbow luxation with avulsed joint capsule. Three suture anchors have been pre-placed into the ulna and will be used to re-position the joint capsule.

Capsulorrhaphy for Hip Luxation 

A number of methods for maintenance of surgical reduction of hip luxations are currently popular and include: the toggle pin method, ilio-femoral sutures to limit external rotation of the hip, and caudo-distal transposition of the greater trochanter. Each of these methods depends on the joint capsule and associated muscles for acute and long-term maintenance of joint stability. If the joint capsule is severely traumatized and not conducive to primary repair, some surgeons will elect to perform a capsulorrhaphy or dorsal augmentation of the joint capsule. This is accomplished by placing sutures from the dorsal acetabular rim to the proximal femur. These sutures are utilized to augment or mimic the strength of the dorsal aspect of the joint capsule with the hope that this added strength will assist in maintaining joint integrity while healing of the compromised joint capsule occurs.  Ilio-femoral sutures can be a part of this dorsal augmentation or utilized alone. The purpose of the ilio-femoral suture is to limit external rotation of the hip and thus decrease likelihood of repeat luxation. With any of the just mentioned surgical methods for stabilization of hip luxations, it is important to remember that the use of sutures and anchors must be considered temporary solutions until the joint capsule and periarticular soft tissue can heal. As such, patients with poor hip conformation are not good candidates for these methods of repair and should be considered for salvage procedures, such as FHNE or THR.

  • Joint Capsule Reattachment 

  • Capsulorrhaphy for Hip Luxation 

Tendon and Ligament Reattachment 

Other tendon and ligament injuries, such as the origin of the gastrocnemius, long digital extensor tendon of origin, and gluteal tendons of insertion may provide ideal indications for the use of suture anchors. In these cases, anchors are used in a fashion similar to treatment of collateral ligament injuries. Treatment of calcanean, patellar, and triceps tendon injuries may be successfully treated using suture anchors in very select cases. However, their use is not generally recommended for these structures due to the very dense bone at the attachment sites, the anatomical considerations unique to these sites, and the availability of other techniques which may be more appropriate for these problems.

Stabilization of Cranial Cruciate Deficient Stifles 

A few recommendations are provided regarding use of suture anchors for stabilization of cranial cruciate deficiency. General guidelines and concerns can be outlined since questions are being asked about the appropriateness of this procedure. Surgeons who assisted in development and testing of these suture anchors were referral orthopedic surgeons utilizing tibial plateau leveling osteotomy (TPLO) as their treatment of choice for cranial cruciate tears. As such most developmental cases were not related to CCL repair – except for deranged stifles. However, in select patients, suture anchors of appropriate size have been utilized instead of the fabella for extracapsular reconstructions. Use of suture anchors enhances more isometric placement of sutures than using the fabella; however, in large active patients, it must be stressed that combinations of techniques should be considered. For example, a fabellar suture in addition to an anchor suture could be utilized along with capsular imbrication and/or fascia latae transfer. Remembering that all prosthetic suture/ligament applications will likely fail (this includes current fabellar-tibial suture loops), it must be hoped that peri-articular fibrosis will maintain joint stability after such failure. Perhaps the use of multiple techniques creates a situation in which multiple failures must occur over time before there is only fibrosis and fascial transfer to maintain long term stability. More and more customers are incorporating additional use of suture anchors as a portion of their CCL repair in challenging patients. Anchors in this catalog are relatively small to consider as a primary CCL repair technique in most patients. Anchor size must be viewed in context of the patient. Do not purchase these specific suture anchors as the sole method of extracapsular repair of cruciate disease in large patients; however, selected adjunct use of these anchors may simplify and enhance cruciate repairs in smaller patients. 

  • Tendon and Ligament Reattachment 

  • Stabilization of Cranial Cruciate Deficient Stifles

Anchor-Orthopedic Wire-Polymethylmethacrylate-Acetabular Fracture Repair

Articular fractures should be anatomically reduced and rigidly fixed. With acetabular fracture repair, it is often difficult to contour available bone plates to maintain accurate, anatomic alignment as screws are tightened into the plate. In other words, if the plate is nearly contoured, initial screw application will appear accurate; however, as additional screws are placed and tightened, any error in plate contour will result in translation of the bone and loss of reduction. To overcome the difficulty of plate contouring, special acetabular plates have been developed. In addition, reconstruction plates have been utilized in larger canine patients.  

Reports (Lewis, et al: Veterinary Surgery. 1997 May-Jun; 3:223-34) have outlined an alternate procedure for repair of acetabular fractures in small animal patients. Specifically, bone screws or similar devices are placed along the dorsal acetabular rim and are connected with orthopedic wire. The fracture is held in reduction while PMMA is applied over the implant/wire composite frame. The PMMA conforms to the surface of the bone and strength is achieved because the composite structure is held in place by the threaded implants. Anchors may be beneficial when used for this technique, as they provide excellent bone purchase while allowing for easy retention of the orthopedic wire in the eyelet. It is important to note that to date, this method has been used in relatively small patients.

  • Anchor-Orthopedic Wire-Polymethylmethacrylate-Acetabular Fracture Repair