The use of a stifle flexion device to manage avulsion of the lateral head of the gastrocnemius muscle in a cat

This report describes the diagnosis and treatment of a traumatic avulsion of the lateral head of the gastrocnemius muscle in a three-and-a-half-year-old male neutered Domestic Shorthaired cat. Surgical repair was achieved using a modified three-loop pulley suture pattern passed through a suture anchor inserted at the point of origin of the tendon and around the fabella. A stifle flexion device was utilised during the postoperative period to protect the repair. Follow-up at five months showed a return to normal function. This is the first report of avulsion of the lateral head of the gastrocnemius in a cat.     

Strength Characteristics and Failure Modes of Locking-Loop and Three-Loop Pulley Suture Patterns in Equine Tendons

Size 3-0 polydioxanone was used as a single strand, single braid (3 strands), or double braid (6 strands) to create six suture material-pattern combinations for equine tenorrhaphy: single-strand locking loop, single-braid locking loop, double-braid locking loop, single-strand three-loop pulley, single-braid three-loop pulley, and double-braid three-loop pulley. Maximum load to failure for the single-strand locking loop (46.1 +/- 2.9 newtons [N]) was less than for all other sutures (range, 103-155 N). The load required to form a 2 mm gap between tendon ends was greater for the single-braid three-loop pulley (66.7 +/- 6.9 N) and double-braid three-loop pulley (85.4 +/- 17.7 N) than any other sutures. The load required to produce a 10 mm gap was least for the single-strand locking loop (34.3 +/- 3.9 N) and greatest for the double-braid three-loop pulley (131.5 +/- 27.5 N). Gap between tendon ends at maximum load was greater for the single-braid (18.1 +/- 0.9 mm) and double-braid (19.2 +/- 2.2 mm) locking loops than for any other sutures. Suture material broke in 53% of the locking-loop tests but in only 17% of the three-loop pulley tests. Tendon matrix disruption accounted for 43% of the locking-loop failures and 77% of the three-loop pulley failures. The three-loop pulley pattern provided more support, less tendon distraction, and less tendon matrix constriction and distortion than the locking-loop pattern.(ABSTRACT TRUNCATED AT 250 WORDS)     

Biomechanical and clinical evaluation of a modified 3-loop pulley suture pattern for reattachment of canine tendons to bone

OBJECTIVE: To describe a modified 3-loop pulley suture pattern for the reattachment of canine tendons to bone along with a biomechanical comparison with the locking-loop suture. STUDY DESIGN: In vitro biomechanical study and clinical case report. ANIMALS OR SAMPLE POPULATION: Biomechanical study: 10 paired gastrocnemius tendons and calcaneii harvested from 5 canine cadavers. Case report: a Doberman with avulsion of the gastrocnemius tendon of insertion. METHODS: Biomechanical study: paired tendons were reattached to the calcaneus with either a modified 3-loop pulley pattern or a locking-loop pattern. Tensile loading to failure was performed. A direct, non-contact, method of gap measurement, using digital video, was used to measure gap formation. Load required to initiate gap formation (defined as load at a 1 mm gap) and to produce a 3 mm gap was evaluated in addition to maximum load and gap at failure. RESULTS: Mean (+/-SEM) 1 mm gap loads were 31.0+/-4.2 and 17.2+/-2.5 N, mean 3 mm gap loads were 49.1+/-2.4 and 28.9+/-3.2 N, and mean maximum loads were 72.9+/-4.3 and 55.8+/-2.2 N for the modified 3-loop pulley suture and the locking-loop suture, respectively. These differences were statistically significant (P<.05). The gap at failure was similar for both repairs. The clinical case remained sound 7 months postoperatively. CONCLUSIONS: A modified 3-loop pulley pattern is biomechanically superior to a locking-loop pattern for reattachment of the canine gastrocnemius tendon to bone and may be suitable for clinical use. CLINICAL RELEVANCE: Tendon repairs with a gap >3 mm are reported to be at increased risk of rupture during the first 6 weeks postoperatively. A modified 3-loop pulley pattern resists gap formation better than a locking-loop pattern.     

Mechanical Properties of Four Suture Patterns for Transected Equine Tendon Repair

Thirty-six superficial digital flexor tendons from nine fresh equine cadavers were transected and sutured with size 2 monofilament nylon. Nine tendons were repaired with each of four suture patterns: single-locking loop, double-locking loop, triple-locking loop, or three-loop pulley. The times required for application, tensile strengths, resistance to distraction (gap), and modes of failure were analyzed. The mean times required were: single-locking loop, 3 mins, 15 secs; double-locking loop, 4 mins, 15 secs; triple-locking loop, 10 mins, 50 secs; and three-loop pulley, 4 mins. The double-locking loop, triple-locking loop, and three-loop pulley suture patterns were stronger than the single-locking loop. The triple-locking loop and three-loop pulley patterns were close in strength and only the triple-locking loop was stronger than the double-locking loop. The three-loop pulley had the greatest resistance to gap formation and its mode of failure was different from the others. The three-locking loop suture patterns failed by suture breakage but the three-loop pulley failed first by suture pull-out and then by suture breakage.     

Achilles Tendon Repair in Dogs Using the Semitendinosus Muscle: Surgical Technique and Short-Term Outcome in Five Dogs

Objective— To describe augmentation of primary Achilles tendon repair using suture with a semitendinosus muscle flap and report outcome in 5 dogs.
Study Design— Prospective clinical study.
Animals— Dogs (n=5) with Achilles tendon rupture (n=6).
Methods— After tendon repair with #2 polypropylene in a 3-loop pulley suture pattern, the lateral one-half of the semitendinosus muscle was transected from the ischium, rotated distally then sutured with #2 polypropylene to the calcaneus in a 3-loop pulley pattern. The epitenon was sutured to the muscle flap fascia with interrupted sutures. All dogs had a bivalved cast for 2 weeks then a cranial splint for 2–6 weeks. Lameness scores (0=stands and walks normally to 4=non-weight-bearing lameness, plantigrade stance on affected pelvic limb) were determined every 2–3 weeks postoperatively for 12 weeks. Outcome was determined from telephone questionnaire of owners.
Results— Four had lameness scores of 0, the 5th had a score of 1 at 12 weeks. Three owners were very satisfied with outcome. Minor complications included cast sores (2 dogs), infection (2), and acute swelling (1); 1 major complication occurred (infection resulting in reoperation).
Conclusions— Semitendinosus flap augmentation resulted in early return to function without prolonged postoperative immobilization. Three dogs returned to full work/activity after repair.
Clinical Relevance— Augmentation of primary Achilles tendon repair with a semitendinosus flap can be considered in dogs with chronic rupture but further investigation of the long-term outcome using this technique is needed.     

Collateral ligament reconstruction in two horses following traumatic avulsion fracture using a knotless suture anchor construct

This case report describes a technique for repair of medial collateral ligament avulsions in two horses. Both horses sustained traumatic injuries resulting in avulsion fractures at the origin of their medial tarsal and carpal collateral ligaments. This report describes the use of a knotless suture anchor to mechanically reconstruct medial collateral ligament avulsion injuries in two horses. The first horse, a 9‐year‐old Hannovarian Warmblood gelding presented for an acute nonweightbearing lameness in the right hindlimb. The injury was localised to the medial malleolus of the tibia and an avulsion fracture of the origin of the short medial collateral ligament of the tibiotarsal joint with disruption of the ligament was found on radiographs and ultrasound. The horse was taken to surgery and a reconstruction of the short medial collateral ligament was performed with a modified single row construct using a biocompatible, multistrand, long chain ultra‐high molecular weight polyethylene braided composite suture tape (2 mm Fibertape) and a single knotless suture anchor (5.5 × 19.1 mm PEEK SwivelLock C). The second horse, a 5‐year‐old Thoroughbred gelding presented for an acute nonweightbearing lameness in the left forelimb. The injury was localised to the medial styloid process of the radius and an avulsion fracture of the origin of the medial collateral ligament of the antebrachial carpal joint was found on radiographs and ultrasound. The horse was taken to surgery and a similar reconstruction procedure was performed to the collateral ligament. Both horses were recovered in a Robert Jones bandage without the use of casts or splints and recovered without incident. Both horses are sound and returned to previous level of athletic performance at 18 months and 8 months, respectively.     

A modified Maquet technique for management of cranial cruciate avulsion in a cat

This case report describes the management of cranial cruciate ligament avulsion from the femur of a four‐year‐old Norwegian Forest cat that presented with a history of lameness which had not improved with conservative treatment. During medial arthrotomy, avulsion of the cranial cruciate ligament from the caudomedial aspect of the lateral femoral condyle was suspected and the torn portion resected. A modified Maquet technique was performed on the left tibia resulting in a rapid improvement in lameness postoperatively. Histopathology of the resected cranial cruciate ligament confirmed avulsion. To the authors’ knowledge this is the first reported use of this technique in the cat, and the first of stifle instability due to cranial cruciate ligament avulsion from the femur in the cat.     

Avulsion of the insertion of the gastrocnemius tendon in three dogs

Three cases are described in which avulsion of the insertion of the gastrocnemius tendon occurred. All three dogs were presented with a lameness of long duration. In two cases the avulsion followed a treatment for tendinitis of the Achilles tendon by local infiltration of corticosteroids. One dog was presented with this condition after a long standing treatment for cystitis. The three dogs were presented with characteristic clinical and radiological signs accompanying this tendon injury. Two of these patients were treated by surgical repair of the avulsed tendon combined with temporary immobilization of the hock accomplished by transfixation using methyl methacrylate* as external fixation. Within twelve weeks following surgery, these dogs had regained normal function without any evidence of gait abnormality. The third dog, treated conservatively failed to regain normal function.     

Avulsion of the triceps tendon insertion in a cat.

Avulsion of the insertion of the triceps tendon, which had a pre-existing tendinopathy, is described in a cat. The tendon was re-attached to the olecranon and the repair was immobilised using a type la trans-articular external skeletal fixator. The treatment was successful, however, mild and intermittent lameness persisted. Although it is an uncommon condition in small animals, the diagnosis should be based on careful clinical and radiographic examination.     

Unusual muscle and tendon disorders of the forelimb in the dog

Five dogs with unusual muscle and tendon disorders of the forelimb are described. In one dog, mineralisation of the tendon of insertion of the supraspinatus muscle was treated surgically but lameness returned following the resumption of exercise. Of two cases of avulsion of the origin of the extensor carpi radialis muscle, one was successfully managed conservatively while the other needed surgical intervention to resolve the lameness. A single case of chronic avulsion/rupture of the tendon of insertion of the extensor carpi radialis muscle was successfully managed conservatively while a case of medial displacement of the biceps brachii tendon was surgically corrected by repair of the transverse humeral ligament. The aetiology, diagnosis and management of the above conditions is discussed.     

Evaluation of an Autologous Tendon Graft Repair Method for Gap Healing of the Deep Digital Flexor Tendon in Horses

A sutured tenorrhaphy technique that incorporated an autologous tendon graft was compared mechanically and histologically with a sutured tenorrhaphy at 6, 12, and 24 weeks after repair. Tenorrhaphy was performed in the forelimb tendon of the deep digital flexor muscle and the graft was taken from the hindlimb tendon of the lateral digital extensor muscle; one forelimb site included the graft, whereas the other forelimb site was not grafted. Tenotomies were made immediately proximal to the insertion of the accessory ligament into the tendon of the deep digital flexor muscle. Grafted and nongrafted tenorrhaphies were sutured with 2 polydioxanone in a modified double locking-loop pattern. Limbs were supported with a bandage and an extended elevated heel shoe that maintained the dorsal hoof wall angle at 70° to 75°; this support was removed at 12 weeks and dorsal hoof wall angle was maintained at 40° to 45° for the remainder of the study. Gap formation (2.5 ±.3 cm) was evident at all tenorrhaphy sites at 3 days on ultrasound examination. In grafted repairs, the breaking stress was increased ( P <.001) between 6 weeks (2.56 ±.44 MPa) and 12 weeks (17.69 ± 7.68 MPa), with grafted tendon having a greater breaking stress than nongrafted tendon (8.77 ± 2.5 MPa; P <.05). No differences in breaking stress were evident at 24 weeks. At 12 weeks, repair tissue in grafted tendon was histologically more mature, had less cellularity, better fibroblast orientation and more homogeneous collagen matrix than nongrafted tendon. Polydioxanone suture was still evident histologically at 24 weeks and was associated with minimal cellular reaction. Incorporation of an autologous tendon graft improved the mechanical properties and histological quality of the repair tissue in equine flexor tenorrhaphies at 12 weeks but not at 24 weeks after repair.     

Glenoid dysplasia and bicipital tenosynovitis in a Maine coon cat

This report describes a rare case of bicipital tenosynovitis in a Maine coon cat. The cat, a three-and-half-year-old neutered female, presented with chronic weightbearing lameness of the left forelimb. Flexion of the left glenohumeral joint and extension of the left cubital joint were resented, and palpation of the biceps brachii tendon in the bicipital groove elicited pain. A mild incongruity of the joint with mild degenerative changes was seen radiographically. Glenohumeral joint dysplasia was suspected. Ultrasound examination revealed marked thickening of the bicipital tendon and moderate effusion of the left bicipital tendon sheath. Positive contrast radiography of the joint confirmed dilation of the tendon sheath. A tentative diagnosis of bicipital tenosynovitis was made and confirmed on arthrotomy. Surgical removal of osteophytes resulted in the cat being free from pain but a mild lameness recurred six months after surgery.     

In Vitro Comparison of the Three Loop Pulley and Locking Loop Suture Patterns for Repair of Canine Weightbearing Tendons and Collateral Ligaments

Both triceps tendons and the medial collateral ligaments of both stifles of 10 freshly euthanized dogs were sharply transected. One tendon and one ligament of each dog were sutured with a three loop pulley pattern, and the opposite tendons and ligaments were sutured with a locking loop pattern. The tendons and ligaments were harvested with their muscular and bony attachments. The anastomoses were slowly tested in tension until failure occurred. The amount of tensile load required to produce failure of the anastomosis, the amount of distraction of the sutured ends prior to failure, and the modes of failure were recorded. In both tendons and ligaments, the three loop pulley pattern provided significantly greater tensile strength (p < 0.01) and allowed significantly less distraction between the sutured ends (p < 0.01) than the locking loop pattern. In tendons, disruption of the suture material was the most common mode of failure with both patterns. In ligaments, both patterns failed most commonly by pulling free from the tissue.     

Avulsion of the proximal digital annular ligament in five hindlimbs

Avulsion of the proximal attachment of the proximal digital annular ligament (PDAL) was identified in five horses based on characteristic radiographic findings and supported by ultrasonographic examination in four horses. In two cases, PDAL avulsion was associated with acute onset lameness based on physical examination (both animals) and diagnostic analgesia (one animal), and was the only lesion identified. Both horses became sound after a period of rest. Radiographs repeated 11 years later in one animal showed minimal change in the appearance of the lesion. PDAL avulsion was associated with a substantial tear of the deep digital flexor tendon in another horse and in the remaining two cases PDAL avulsion was not associated with lameness. A dissection study found that the proximodistal extent of the proximal PDAL attachment, expressed as a proportion of the length of the proximal phalanx, was significantly (P = 0.011) greater in hindlimbs (11.48 ± 1.01%) compared with forelimbs (8.55 ± 1.06%). This finding may explain why hindlimbs appear at greater risk of PDAL avulsion. In conclusion, while PDAL avulsion can be a cause of acute lameness which, in uncomplicated cases, responds to rest, it can also be an incidental radiographic finding.     

The three-loop pulley suture versus two locking-loop sutures for the repair of canine achilles tendons

OBJECTIVE: To compare a 3-loop pulley suture pattern with 2 locking-loop sutures for the repair of components of the canine Achilles mechanism. STUDY DESIGN: In vitro biomechanical study. ANIMALS: Forty-eight paired tendons collected from 9 canine cadavers. METHODS: Paired tendons were repaired with either a 3-loop pulley suture or 2 locking-loop sutures and tensile tested to failure. To ensure accurate anastomosis gap measurement a direct, non-contact, method of gap measurement, using digital video, was devised. Load initiating gap formation (defined as load at a 1 mm gap) and load producing a 3 mm gap were evaluated in addition to maximum load, gap at failure, mode of failure, and time spent placing the sutures. RESULTS: Maximum load values were similar for both repairs. The mean 1 mm gap loads were 44.0 and 18.4 N, and the mean 3 mm gap loads were 56.3 and 34.7 N, for the 3-loop pulley pattern and the 2 locking-loops, respectively; these differences were statistically significant. The 3-loop pulley pattern was faster to place and resulted in a smaller gap at failure. All but 2 repairs failed by suture pull out. CONCLUSIONS: The 3-loop pulley pattern is more resistant to gap formation during tensile loading, and is quicker to place, than 2 locking-loop sutures. CLINICAL RELEVANCE: Gap formation can significantly delay tendon healing. Tendon repairs with a gap >3 mm are reported to be at increased risk of rupture during the first 6 weeks postoperatively.     

Use of vacuum-assisted closure for management of a large skin wound in a cat

CASE DESCRIPTION: A 9-month-old domestic shorthair cat was evaluated after being struck by a car. CLINICAL FINDINGS: The cat had a fractured tibia and avulsion of the tail base. Motor and deep pain sensation were absent from the tail. The fractured tibia was repaired 2 days after the trauma. On the third day, the cat developed tachypnea, dyspnea, high serum urea nitrogen and total bilirubin concentrations, epistaxis, persistent hypotension, and oliguria. The cat recovered with supportive care but developed extensive necrosis of the skin on the dorsum by 9 days after the initial trauma. TREATMENT AND OUTCOME: The skin was debrided from the caudal portion of the scapula to the anus and down each pelvic limb to the level of the distal portion of the femur. The tail was amputated. Wet-to-dry bandages were applied to the wound for 3 days. Approximately 50% of the wound underwent delayed primary closure, and the remainder was managed with vacuum-assisted closure. A healthy granulation bed was quickly established. Vacuum-assisted closure was also applied after graft application. Graft acceptance was 100%, and use of the vacuum-assisted closure bandage was not associated with the complications associated with the traditional bandage. CLINICAL RELEVANCE: Vacuum-assisted closure is a useful, easily applicable technique for open and grafted wounds, even when wounds are in challenging anatomic locations.     

RADIOGRAPHIC, COMPUTED TOMOGRAPHIC AND MAGNETIC RESONANCE IMAGING EVALUATION OF A CHRONIC LONG DIGITAL EXTENSOR TENDON AVULSION IN A DOG

Long digital extensor tendon avulsion is reported in a 5 month old Great Dane. Clinically the dog presented with a unilateral weight-bearing pelvic limb lameness. Joint effusion was present and there was pain and crepitance associated with flexion of the stifle. Orthopedic evaluation and radiographs were suggestive of a long digital extensor tendon injury which was confirmed by computed tomography and magnetic resonance imaging.The injury was surgically repaired with screw and spiked washer fixation.     

Buried tension sutures: force-tension comparisons of pulley, double butterfly, mattress, and simple interrupted suture patterns

OBJECTIVES: To compare suture patterns (simple interrupted, modified pulley, horizontal mattress, double butterfly) by use of a novel in vitro model that quantifies force required for closure against tension. STUDY DESIGN: In vitro study. SAMPLE POPULATION: Suture constructs. METHODS: An in vitro suturing frame was constructed with extension springs to provide a standard resistance against movement of 2 panels of loops toward each other. Four different suture patterns were applied to the frame in randomized trials. The frame was affixed to a tensiometer that measured the force required for each suture pattern to close a fixed distance (3.81 cm) at a constant rate (5.08 cm/min) against the tension (0.6 kg/cm) of the extension springs. The closure distance and tension were selected subjectively to mimic tension encountered clinically during wound reconstruction oncologic surgical procedures. RESULTS: The modified pulley suture required the least force to close, followed by the double butterfly, simple interrupted, and horizontal mattress patterns. CONCLUSIONS: The modified pulley suture and double butterfly suture patterns require less force to close a given distance under tension than either simple interrupted or horizontal mattress suture patterns. CLINICAL RELEVANCE: Application of tension relieving suture techniques for fascia, subcutaneous, and buried-knot subdermal suturing should be considered to facilitate direct closure of wounds under tension. Modified pulley and double butterfly suture patterns offer some mechanical advantage by requiring less force to achieve closure compared with other suture patterns that might be used in reconstructive surgery.     

Treatment of chronic complete rupture of achilles tendon in three dogs with locking loop suture and own suture technique

The present case report describes three heavy dogs, Caucasian Shepherd breed, with chronic complete traumatic rupture of Achilles tendon, which was repaired with two types of sutures. Surgical treatment involved shortening the Achilles tendon, and using a locking loop suture technique and own suture technique with four buttons. Additionally, positional screw and cast supported the sutures. Twelve months postoperatively no discomfort and lameness were observed on clinical examination. This paper shows that treatment of chronic complete rupture of Achilles tendon with locking loop suture and own suture technique gives good results.