Minimally invasive ultrasound-assisted cutting thread tenotomy of the deep digital flexor tendon in horses: An ex vivo study.

OBJECTIVE: To evaluate the feasibility and limitations associated with a minimally invasive ultrasound-assisted cutting thread technique for tenotomy of the deep digital flexor tendon (DDFT) in horses. STUDY DESIGN: Ex vivo study. SAMPLE POPULATION: Twenty cadaveric forelimbs. METHODS: Forelimbs were placed on a jig to mimic a standing semiflexed position and the midmetacarpal region was prepared to perform tenotomy of the DDFT using a percutaneous technique with a cutting thread. For that purpose, the thread was placed percutaneously around the DDFT (first dorsally and then palmarly) with the aid of a curved 20 gauge spinal needle. Tendon palpation/manipulation and ultrasonographic assessment assisted thread placement. Procedure time and skin puncture size were recorded. Limbs were then dissected to evaluate the degree of DDFT transection and the presence of any iatrogenic lesions. RESULTS: The DDFT was completely transected in all cases. Minor lesions of the superficial digital flexor tendon were found in 11/20 limbs and considered clinically irrelevant. However, the neurovascular bundle was damaged in 6/20 limbs (four limbs had nerve damage and two limbs had a nerve and either a palmar artery or vein damaged). The skin puncture hole sizes ranged from undetectable to 5 mm long. The average duration of the procedure was 7 min and 38 s (range: 4 min 56 s to 10 min 19 s). CONCLUSION: A DDFT tenotomy can be performed reliably with a percutaneous cutting thread technique. However, refinement of the technique is required to minimize iatrogenic damage. CLINICAL SIGNIFICANCE: The reported technique allows a DDFT tenotomy to be performed in a minimally invasive manner and has the potential to be clinically applicable.

Ex vivo study shows novel, rapid, suture-free tenotomy technique for the equine deep digital flexor tendon.

OBJECTIVE: To describe the feasibility of a novel thread-transecting technique for the tenotomy of the equine deep digital flexor tendon (DDFT). ANIMALS: 39 equine distal limb specimens. METHODS: Under ultrasonographic guidance, a surgical thread was percutaneously placed around the DDFT through 2 needle punctures (lateral and medial) using a Tuohy needle in equine limbs (22 forelimbs, 17 hindlimbs). The DDFT was transected by a back-and-forth motion of the thread until the loop emerged from the entry puncture site. Each specimen was dissected and assessed for completeness of transection and iatrogenic damage under direct visualization. Descriptive statistics were reported. RESULTS: Complete DDFT transection was achieved in all 39 limbs, taking an average of 8.6 minutes per procedure. Iatrogenic damage to surrounding structures occurred in 17 (44%) limbs, with 6 (15%) limbs having more than 1 structure damaged. Damage to the communicating branch of the palmar or plantar nerves was the most commonly seen. CLINICAL RELEVANCE: DDFT tenotomy in equine limb specimens was effectively performed using a novel thread-transecting technique. The procedure is quick, and no suturing is needed, but damage to surrounding structures is possible. Further assessment of the procedure and clinical significance of its potential iatrogenic damage in clinical cases is needed.

Application of tenotomy on Korean native cattle (Hanwoo) with spastic paresis symptoms in the field.

Bovine spastic paresis (BSP) is a neuromuscular disorder characterized by hypertension and stiffness of hindlimb. Two Korean native cattle (Hanwoo) calves developed BSP or BSP-like symptoms, and a tenotomy of superficial tendon of medial head and deep tendon of lateral head of gastrocnemius muscle was performed for treatment. A cast was applied postoperatively to prevent muscle rupture and was removed three weeks later. The prognosis was evaluated at 3 weeks, 6 and 18 months postoperatively. Neither calf showed any other postoperative sequelae. This is the first case study to report the diagnosis, treatment, and prognosis of BSP in Hanwoo.

Effect of single and double hemitenotomy on equine deep digital flexor tendon length and strength in experimental load challenges.

OBJECTIVE: To evaluate a double hemitenotomy (DHT) technique as an alternative to complete deep digital flexor (DDFT) tenotomy. STUDY DESIGN: Experimental ex vivo study. SAMPLE POPULATION: Isolated DDFTs (n = 30) and cadaveric forelimbs (n = 16). METHODS: In part 1, 15 isolated DDFT pairs were used. Two hemitenotomies were created in 1 DDFT while the other served as reference. Monotonic tensile load was applied. Tendon lengthening, load reduction, and load at failure were recorded. In part 2, 16 cadaveric forelimb pairs were subjected to DHT followed by complete tenotomy (CT) under monotonic compressive load. Differences between DHT and controls were assessed with Wilcoxon signed rank tests or Friedman tests. RESULTS: In isolated tendons and cadaveric forelimbs, DHT resulted in DDFT lengthening (median, +1.9 mm and + 3.05 mm) and load reduction (median, -16.7 and -11.2 kg). Less lengthening was achieved with DHT compared to CT (P = .008). Load reduction did not occur between DHT and CT was observed during compressive testing (P = 1). Load reduction following the first hemitenotomy incision was smaller when compared to the second (P = .022). Isolated DHT tendons failed at a tensile load of 195 kg, while no intact tendons failed (P = .0001). CONCLUSION: Double hemitenotomy was comparable to CT in load reduction. It reduced tensile strength, but load at failure was similar or exceeded the estimated DDFT load at stance. CLINICAL SIGNIFICANCE: Hemitenotomy may be a useful alternative for surgical management of horses with laminitis, but in vivo studies are needed to confirm these findings.

Biomechanical evaluation of a novel barbed suture pattern with epitendinous suture augmentation in a canine flexor tendon model.

OBJECTIVE: To determine the effect of a novel barbed suture pattern (NBSP) compared to a three-loop-pulley (3LP) with and without epitendinous suture (ES) augmentation on the biomechanical strength and gap formation of repaired canine tendons. STUDY DESIGN: Ex vivo, cadaveric, randomized, experimental study. SAMPLE POPULATION: Forty, adult superficial digital flexor tendons (SDFT). METHODS: SDFT were randomly assigned to one of four groups (n = 10/group). Sharp tenotomy was performed and repaired with 3LP, NBSP, 3LP + ES, and NBSP + ES. Constructs were tested to failure while evaluating yield, peak, and failure loads, loads at 1 and 3 mm gap formation, and failure mode. RESULTS: Constructs augmented with ES sustained 80% greater yield (p < .001), peak (p < .001), and failure (p < .001) loads, with no difference between 3LP + ES and NBSP + ES constructs regarding peak (p = .614), and failure forces (p = .865). Loads resulting in 1 and 3 mm gap formation were greater when constructs were augmented with an ES (p ≤ .003). Failure mode differed between groups (p < .001), occurring predominantly due to suture pull-through in 3LP and NBSP groups compared to tissue failure distant to the repair site in ES augmented constructs. CONCLUSION: Tendons repaired with the NBSP used in this study resisted similar forces as those repaired with 3LP. Augmentation with an ES improved the biomechanical properties of repaired constructs, including resistance to gap formation. CLINICAL RELEVANCE: The NBSP repair tested here may be advantageous over monofilament suture repair as it uses a similar-sized barbed core suture but eliminates the requirement for knot tying.

Minimally invasive tenotomy of the tibial insertion of the semitendinosus muscle: An ex vivo study in horses.

OBJECTIVE: To describe a minimally invasive technique for semitendinosus tenotomy with ultrasonographic guidance and to evaluate procedural complications. STUDY DESIGN: Experimental study. SAMPLE POPULATION: Cadaveric equine hind limbs (n = 16). METHODS: A stab incision was performed distocaudal to the tibial insertion of the semitendinosus muscle with ultrasonographic assistance. After transection of the tendon with an arthroscopic retrograde knife, the tendon edges palpably retracted, and complete transection was confirmed by ultrasound. Limbs were dissected to confirm the degree of tendon transection and to identify iatrogenic trauma to surrounding soft tissues. RESULTS: Tenotomy was complete in all limbs, resulting in a palpable gap forming between tendon edges. Superficial iatrogenic laceration to the underlying gracilis muscle (n = 2) or gracilis fascia (n = 1) was apparent in 3 of 16 limbs. CONCLUSION: Ultrasound-assisted tenotomy of the tibial insertion of the semitendinosus muscle was reliably performed in a minimally invasive fashion with minor iatrogenic damage. CLINICAL SIGNIFICANCE: Minimally invasive tenotomy of the semitendinosus muscle can be performed with ultrasonographic assistance and should be considered as an alternative technique for surgical management of fibrotic semitendinosus myopathy.

Technique description: Incisionless ultrasound-assisted biceps tenotomy in dogs.

Background: Bicipital tendinitis and/or tendinopathy is a common cause of forelimb lameness in dogs, particularly in larger and more active patients. Although conservative treatment aimed at resolving discomfort and preserving the tendon remains the primary therapeutic goal, in certain cases it is necessary to surgically transect the tendon to eliminate pain and lameness. Transection of the tendon can be performed by open arthrotomy, arthroscopically, or percutaneously using a scalpel blade. This paper examines the utility of a modified percutaneous approach using a hypodermic needle in place of a scalpel blade, under ultrasound-guided assistance. Aim: To develop and describe a surgical technique for performing a percutaneous biceps tenotomy using a hypodermic needle under ultrasound guidance. Method: The technique was piloted using the shoulders of 12 cadaver dogs initially and once developed, then applied to another 12 cadavers. The final procedure was performed on a total of 22 shoulders. Assessments were recorded on time to complete the procedure, completeness of bicipital tendon transection, and presence of any iatrogenic damage to associated joint structures. Results: Procedure time averaged fewer than 2 minutes. Complete transection was achieved in 20 out of 22 of the shoulders, with evidence of incomplete transection discernable by ultrasound imaging in the remaining two shoulders. One cadaver shoulder experienced iatrogenic damage secondary to incorrect hypodermic needle angulation. Conclusion: Percutaneous biceps tenotomy using a hypodermic needle is an efficient and straightforward procedure. The lack of a surgical incision makes it the least invasive technique devised so far. Ultrasound imaging allows the practitioner to assess the completeness of the transection increasing precision.

Arthroscopic tenotomy for treatment of biceps tendon luxation in two apprehension police dogs.

CASE DESCRIPTION: A 7.5-year-old 37.8-kg (83.2-lb) sexually intact male German Shepherd Dog (dog 1) and a 2.6-year-old 28.2-kg (62.0-lb) sexually intact male Dutch Shepherd (dog 2), both apprehension police dogs, were admitted for evaluation of left and right thoracic limb lameness, respectively. CLINICAL FINDINGS: In both dogs, signs of pain were elicited on palpation of the shoulder joint in the affected limb, and a distinct popping of the biceps brachii tendon (BT) was palpable on the craniomedial aspect of the affected joint on flexion and extension and was associated with moderate signs of pain. Biceps brachii tendon luxation (BTL) was diagnosed with dynamic musculoskeletal ultrasonography (both dogs) and MRI (dog 1). TREATMENT AND OUTCOME: Arthroscopic BT release by tenotomy was performed in both dogs. Lameness appeared to have resolved by 8 weeks after surgery and had not recurred by the last follow-up communications at 36 and 9 months after surgery for dogs 1 and 2, respectively. Both dogs successfully returned to their level of work performed before their injury. CLINICAL RELEVANCE: Our findings for the dogs of the present report suggested that arthroscopic BT release could be considered a viable treatment option for BTL in dogs, including police dogs or other high-performance athletic dogs. Although our findings provided encouraging results, further research, best conducted with a multicenter prospective randomized study, would be needed to establish the most reliable treatment of BTL in high-performance athletic or working dogs.

Effect of bite distance of an epitendinous suture from the repair site on the tensile strength of canine tendon constructs.

OBJECTIVE: To evaluate effects of bite distance of an interlocking horizontal mattress epitendinous suture (IHMES) from the repair site on tensile strength of canine tendon repairs. SAMPLE: 72 canine cadaveric superficial digital flexor tendons (SDFTs). PROCEDURES: Transverse tenotomy was performed, and SDFTs were repaired with a locking-loop construct (LL construct) or 3 LL constructs with IHMES suture bites placed 5 (LL + 5ES construct), 10 (LL + 10ES construct), or 15 (LL + 15ES construct) mm from the transection site (18 SDFTs/group). Constructs were loaded to failure. Load at 1- and 3-mm gapping, yield force, failure load, and failure mode were evaluated. RESULTS: Mean ± SD yield force and failure load for LL constructs were significantly lower than for IHMES constructs. Load at 1- and 3-mm gapping was significantly higher for IHMES constructs. Increasing the bite distance significantly increased construct strength (134.4 ± 26.1 N, 151.0 ± 16.8 N, and 182.1 ± 23.6 N for LL + 5ES, LL + 10ES, and LL + 15ES constructs, respectively), compared with strength for the LL construct. Failure mode differed significantly among constructs when an IHMES was used. CONCLUSIONS AND CLINICAL RELEVANCE: Addition of an IHMES to an LL construct led to increased ultimate tensile strength by 2.5 times and significantly reduced gap formation. Increasing the IHMES bite distance increased yield force by 2.1, 2.3, and 2.7 times for bites placed 5, 10, and 15 mm from the tenotomy, respectively. Positioning an IHMES at a greater distance from the repair site provided superior biomechanical strength for tendon repairs in dogs.

Tenotomy of the semitendinosus muscle under standing sedation versus general anesthesia: Outcomes in 20 horses with fibrotic myopathy.

OBJECTIVE: To compare outcomes after semitendinosus tenotomy performed under standing sedation versus general anesthesia. STUDY DESIGN: Retrospective case series. SAMPLE POPULATION: 20 horses with fibrotic myopathy of the semitendinosus muscle. METHODS: Medical records (2002-2015) of horses undergoing tenotomy of the semitendinosus muscle for the treatment of fibrotic myopathy were reviewed. Signalment, history, affected muscles, restrain method, surgical procedures, and short-term outcome as well as complications were retrieved from records. Long-term outcome (gait and athletic function) was assessed at least 6 months postoperatively by conversation with the owners. Pearson's χ2 statistical analysis was used to compare restrain method and affected muscles with overall outcome. Significance was set at P < .05. RESULTS: Tenotomy of the semitendinosus muscle was performed under standing sedation in 8 horses and under general anesthesia in 12 horses. Follow-up period ranged from 9 months to 10 years. Gait was improved to variable degrees in 8 of 14 horses when the semitendinosus muscle alone was affected and in 4 of 6 horses when both the semitendinosus and semimembranosus muscles were involved (P = .11). Six of 8 horses treated under standing sedation and 6 of 12 horses treated under general anesthesia exhibited some improvement in the characteristic fibrotic gait (P = .4473). Five of 6 athletic horses treated under standing sedation and 6 of 9 athletic horses treated under general anesthesia returned to their preinjury level of athleticism. Horses treated under standing sedation had no incisional complications; 2 of 12 horses treated under general anesthesia exhibited incisional drainage. CONCLUSION: Tenotomy of the semitendinosus muscle in horses with fibrotic myopathy leads to similar improvement in gait, whether performed under standing sedation or general anesthesia.

Arthroscopic biceps ulnar release procedure (BURP): technique description and in vitro assessment of the association of visual control and surgeon experience to regional damage and tenotomy completeness.

OBJECTIVES: (1) Describe arthroscopic BURP surgical technique, (2) assess association of visual control and surgeon experience to tenotomy completeness and regional iatrogenic tissue damage. STUDY DESIGN: Cadaveric study. SAMPLE POPULATION: Canine cadavers weighing >20 kg (n = 16; 32 elbows). METHODS: Phase 1 = dissection/anatomic description/procedural refinement (n = 6). Phase 2 = technique description (n = 6). Phase 3 = association of surgeon experience and procedural visual control to tenotomy completion and regional iatrogenic damage (n = 20). Elbows were randomly assigned via coin toss to an experienced- or inexperienced-arthroscopist. Using conventional medial portals, surgeons sought to identify the medial collateral ligament (MCL) and ulnar insertion of the biceps tendon (uBT) before attempting complete tenotomy. Upon procedural completion, surgeons assigned a standardized "visual control score" (VCS) describing viewing that governed procedure and predicted % uBT release, MCL, and median nerve damage. Post-procedural dissection determined actual tenotomy completion and iatrogenic tissue damage. RESULTS: Complete BURP was achieved in 16 of 19 elbows. VCS was associated with tenotomy completeness (P < .01). "Blind" BURP was incomplete in both elbows in which it was attempted. Perception of complete BURP was associated with complete release (P < .01). MCL damage occurred in 10% of elbows. Surgeon experience did not influence VCS, regional damage, or BURP completeness. CONCLUSION: In canine cadavers, arthroscopic BURP can be consistently performed using conventional arthroscopic instruments and portals by both experienced and inexperienced arthroscopists when visual control guides the tenotomy into the distal aspect of the tendon.

[Tenotomy of carpal and digital flexor tendons for correction of congenital neuromyodysplasia in a calf]. / Tenotomie von Karpal- und Zehenbeugesehnen zur Korrektur der Neuromyodysplasie bei einem Kalb.

In a 7-day-old heifer calf, a bilateral flexural deformity of the forelimbs involving the digital flexor tendons, the suspensory ligament and the ulnar and radial carpal flexor tendons was diagnosed. After 2 weeks of conservative treatment consisting of manual stretching of the legs and the application of splints and wooden blocks, which were glued to the soles and extended beyond the tip of the claws, the right forelimb could be extended sufficiently to allow weight bearing, whereas the left forelimb could be passively extended to only approximately 120°. Therefore, tenotomy of the ulnar carpal flexor tendon, the digital flexor tendons and the suspensory ligament was carried out in the left leg. A support bandage was then applied to the leg for 8 weeks, after which the carpus and fetlock could be completely extended passively. Flexural deformity of the carpus caused by contracture of the carpal flexor tendons was treated by means of a tenotomy of the ulnar carpal flexor tendon proximal to the accessory carpal bone, which allowed preservation of the carpal tunnel and avoided the risk of iatrogenic damage to nerves and the carpal joint capsule.