Chapter 84 - Tendon part II surgical tx Flashcards
what was the % of horses that return to racing after desmotomy of ALSDFT?
SDFT tendinopathy treated by DALSDFT returning to racing.
What condition often involves the PAL in horses?
Tenosynovitis of the Digital Flexor Tendon Sheath (DFTS).
Why is the term “PAL syndrome” used?
Due to the difficulty in differentiating primary PAL issues from secondary effects of tenosynovitis.
When is PAL desmotomy indicated?
When PAL constriction impedes flexor tendon function and conservative treatment fails.
Why might PAL desmotomy improve tenoscopic procedures in the DFTS?
It creates more space for maneuvering instruments.
What is a potential downside of open PAL desmotomy?
Risk of wound dehiscence and potential complications like septic tenosynovitis.
What is a benefit of the limited open approach for PAL desmotomy?
It can be done on a standing animal without general anesthesia.
Describe in detail the surgical procedure of SDFT tendinopathy transection of the acessory ligament
With the horse in dorsal or lateral recumbency and the affected limb partially flexed, centesis and distension of the carpal sheath is performed before a tenoscopic portal is created into the carpal sheath 2 to 3 cm proximal to the distal radial physis on the lateral side of the limb, between the ulnaris lateralis and lateral digital extensor muscles. An instrument portal is made immediately proximal to the distal radial physis. A probe is used to palpate the distal and proximal limit of the subsynovially located accessory ligament, which is subsequently transected using a No. 10 scalpel blade on a long handle, a meniscectomy knife, or a tenotomy knife. The ligament is severed directly over the flexor carpi radialis tendon (Figure 84-20). The very proximal portion of the ligament cannot be visualized directly because it extends proximad to the synovial reflection of the carpal sheath. For this proximal portion, careful dissection using punch biopsy forceps is needed for transection, taking care to avoid the perforating blood vessel at the proximal limit of the accessory ligament. Alternatively, transection can also be performed using electrosurgical instruments such as loop-headed or hook-headed monopolar electrodes or bipolar radiofrequency probes.
Figure 84-20. Endoscopic view obtained during tenovaginoscopic desmotomy of the ALSDFT via standard lateral tenoscope and instrument portals. The horse is in dorsal recumbency and distal is on top of the image. The distal parts of the ALSDFT are already transected with a radiofrequency probe exposing the flexor carpi radialis (labeled FCR in the image) tendon. The proximal part of the ALSDFT is still intact (labeled USB-OBS in the image). The DDFT is visible caudally.
What are the 3 tx of PAL transection?
open standing
open GA
Tenoscopic tx
What tool is typically used in tenoscopic PAL transection?
A hooked knife or slotted cannula.
How does radiofrequency probe usage impact the outcome of PAL desmotomy?
It reduces hemorrhage but may cause cellular damage and affect prognosis.
describe the standing open approach of PAL desmotomy
The open approach is performed under general anesthesia in lateral recumbency. The paramedian skin incision extends over the entire length of the PAL slightly abaxially to the palmar/plantar midline. Dissection through the subcutaneous tissue is directed towards the palmar/plantar midline to allow transection of the PAL at the level of the mesotenon and division of adhesions, if required. Routine closure of the subcutis and skin is subsequently performed.with a 1- to 2-cm-long skin incision at the proximal border of the PAL and transection of the ligament with a curved bistoury or a scalpel blade guided by a curved instrument or a groove director.
Figure 84-21. Tenovaginoscopic view showing transection of the PAL using a hook knife. Note the dense and transversely oriented fibers of the PAL palmarly (left side of the image) and the palmar aspect of the SDFT on the right side of the image.
Figure 84-22. The use of the slotted cannula for transection of the PAL. (A) The cannula is guided through the sheath from proximal to distal under arthroscopic control to ensure that it does not lie inside the manica flexoria. (B) The central obturator is removed and a hook knife is introduced (knife not shown) to cut the PAL via the slot in the cannula. This can be introduced from either a proximal or a distal direction, with the arthroscope (without its sleeve) in the opposite end to view the procedure. This technique allows closed and accurate transection of the ligament without damaging other structures.
Figure 84-23. Commonly detected abnormalities that cause tenosynovitis of the digital sheath. (A) Surface tear (arrow) of the DDFT, most commonly found in forelimb tenosynovitis. (B) Rupture (arrow) of the attachments of the manica flexoria, most frequently seen in hind limb tenosynovitis.
What tendon is more affected in DFTS tenosynovitis in the forelimbs?
The Deep Digital Flexor Tendon (DDFT).
What imaging technique helps identify DDFT tears?
Ultrasonography, though sensitivity is limited.
Why might contrast radiography be used before PAL desmotomy?
To identify tendon tears and other intrathecal lesions.
Where are Manica Flexoria (MF) tears most common?
At the medial attachment to the Superficial Digital Flexor Tendon (SDFT).
What is the success rate of tenoscopic MF removal for return to activity?
Approximately 80%.
What is a common complication after MF debridement?
Poor outcomes if treated without full resection.
How long is rest recommended after DFTS tenoscopy?
At least 2 weeks, with a gradual increase in hand-walking duration.
What diagnostic tool improves visualization of DDFT tears in weight-bearing views?
Contrast-enhanced ultrasonography.
What is the preferred tenoscopic portal location for DFTS?
Just distal to the PAL and slightly palmar/plantar of the midline.
What bandage technique is applied for blood-free tenoscopy?
Esmarch bandage with a tourniquet.
DDFT is more commonly affected than the SDFT in the (FL or HL)
forelimb,
tears to the manica flexoria (MF) of the SDFT are more frequently found in (FL/HL)
hindlimb
Intrathecal tears of the DDFT are most commonly directed ________________________ longitudinally/transversally and located at the periphery of the tendon, usually ____________________laterally/medially
Intrathecal tears of the DDFT are most commonly directed longitudinally and located at the periphery of the tendon, usually laterally
sensitivity and specificity of ultrasonography to identify longitudinal tears of the flexor tendons in the DFTS
63% sensitivity and 73% specificity
Contrast radiography can be a further valuable preoperative diagnostic tool with a sensitivity of ____% to detect tears of the MF and ____% to find marginal tears of the DDFT, respectively.
Contrast radiography can be a further valuable preoperative diagnostic tool with a sensitivity of 96% to detect tears of the MF and 57% to find marginal tears of the DDFT, respectively.
Describe in detail the tenoscopy of DFTS
Tenoscopy of the DFTS requires general anesthesia and can be performed in lateral or dorsal recumbency. An Esmarch bandage and tourniquet should be applied to allow for a blood-free tenoscopic visualization and surgical manipulation. The standard tenoscopic portal is located slightly palmar/plantar of the center of the outpouching between the PAL and the proximal digital annular ligament, adjacent and palmar/plantar to the neurovascular bundle, and just distal to the PAL (Figure 84-24).241 This allows evaluation of the proximal and distal parts of the digital sheath, although distal visualization is sometimes easier with the arthroscope inserted through a portal in the proximal digital sheath (e.g., as for a proximal instrument portal). Instrument portals are created where appropriate proximally or distally to allow débridement of any tendon tears with a mechanical resector or a radiofrequency probe
How should be the tears of MF be addressed?
All tears of the MF should be treated by complete tenoscopic resection, since débridement has been associated with poor outcome
describe in detail the resection of MF
For tenoscopic resection of the MF, PAL desmotomy can be first performed via a standard proximal instrument portal if considered necessary because of constriction or for ease of movement of surgical instruments. In the lateral recumbency approach where portals need to be created ipsilaterally, the lateral border of the MF is transected first using a No. 12 scalpel blade or 14G needle inserted through a second instrument portal located laterally at the level of the distal end of the MF, between the DDFT and SDFT. Finally, a third instrument portal is created in the proximal part of the DFTS to introduce a rongeur to grasp For tenoscopic resection of the MF, PAL desmotomy can be first performed via a standard proximal instrument portal if considered necessary because of constriction or for ease of movement of surgical instruments. In the lateral recumbency approach where portals need to be created ipsilaterally, the lateral border of the MF is transected first using a No. 12 scalpel blade or 14G needle inserted through a second instrument portal located laterally at the level of the distal end of the MF, between the DDFT and SDFT. Finally, a third instrument portal is created in the proximal part of the DFTS to introduce a rongeur to grasp
what is the postoperative advice post tensocopy for MF tear?
at least 2 weeks,
2 weeks hand walking can be started at 5 minutes/day, increasing by 5 minutes/week for at least 6 weeks. Thereafter, the duration of rehabilitation depends on the response to treatment.
What is the prognosis for MF tear resection?
Prognosis for a successful outcome defined as soundness and return to previous level of activity is better for patients treated with tenoscopic removal of the MF (~80% success rate) than for tears
what is the prognosis for flexor tendons tears?
flexor tendons (~40% success rate)
Which tendon is most frequently affected in carpal sheath tenosynovitis?
The radial head of the DDFT.
In LR which tendon do you transect to alliviate carpal cannal
This approach also allows tenoscopic transection of the carpal flexor retinaculum to achieve release of the carpal canal in cases of relative constriction (analogous to carpal tunnel syndrome in humans).
Tenoscopic knife for transection of carpal flexor retinaculum is inserted where?
a tenoscopic knife was inserted through an instrument portal located laterally at the level of the distal physeal scar of the radius and used to transect through the retinaculum from the distal aspect of the accessory carpal bone to the level of the instrument portal
Instead of distal physeal scar of radius where can you make the instrument portal?
An alternative technique involves placing the instrument portal 1.5 cm distal to the accessory carpal bone along the dorsolateral aspect of the DDFT to allow better instrument maneuverability.
beside lesions of the radial head of DDFT and carpal flexor retinaculum what is other reasons for carpal tenoscopy?
Other indications for tenoscopy of the carpal sheath are distal radial physeal exostoses, distal radial osteochondromas (see Chapters 95 and 96), and frontal plane fractures of the accessory carpal bone.248 A modified tenoscopic approach into the carpal sheath can also be used to transect the ALDDFT, as described earlier.
What portal location is typical for accessing the carpal sheath in tenoscopy?
Laterally, at the level of the distal physeal scar of the radius.
What alternative imaging modality identifies DDFT lesions in navicular syndrome?
MRI.
What structure is assessed using the transthecal approach to the podotrochlear bursa?
The DDFT lesions and adhesions related to navicular syndrome.
What percentage of horses undergoing podotrochlear bursoscopy return to work?
61%.
What portal approach minimizes cartilage damage in podotrochlear bursoscopy?
The transthecal approach.
What is the risk associated with improper bursoscopic portal placement?
Damage to adjacent structures like the DFTS or vessels.
What is a common primary cause of DDFT issues in navicular syndrome?
Pathological changes proximal to the distal sesamoid bone.
Lesions of DDFT between the MCP/MTP and navicular bursa consist in which types (3)?
consisting of core lesions,
parasagittal splits,
or dorsal border lesions.
What type of DDFT lesions can be debrided and treated with bursoscopy?
Dorsal DDFT
The dorsal DDFT lesions usually they are situated wherE?
proximal to distal sesamoid bone
What are the two surgical technqieus for bursoscopy?
transthecal or a direct approach
Describe in detail the direct approach to navicular bursa
the horse is positioned in dorsal or lateral recumbency, an Esmarch bandage and tourniquet is usually applied, and a 5-mm skin incision is made proximal to the collateral cartilage on the abaxial aspect of the DDFT, palmar to the neurovascular bundle. The arthroscopic cannula/conical obturator unit is introduced distally and axially along the dorsal surface of the DDFT to enter the bursa at the midlevel of the middle phalanx. An instrument portal can be created contralaterally using the same technique.
the direct approach is indicated in which situations
treatment of septic conditions because it should avoid penetration of other synovial cavities and a more distal access is achievable
MEntion the disadvantage and advantage of direct bursoscopy
cadaveric study demonstrated that inadvertent penetration of the DFTS occurs in 37% and of the distal interphalangeal joint in 17%, respectively.253 The direct approach also allows better evaluation of the more distal parts of the podotrochlear bursa compared with the transthecal approach.
describe the advantage of transtechal approach of navicular
The transthecal approach is advantageous for evaluation of the proximal part of the bursa and reduces iatrogenic cartilage damage compared with the direct approach
describe the surgical transtechal approach
For the transthecal approach (Figure 84-25), the horse is positioned in dorsal recumbency with passive flexion of the phalangeal joints, achieved with a half-roll of cotton wool taped to the palmar aspect of a partially flexed carpus. The DFTS is distended and a short skin incision is made over the distended sheath at the level of the proximal interphalangeal joint, just palmar to the neurovascular bundle. A stab incision is subsequently made laterally into the DFTS at the dorsal margin of the DDFT. An arthroscopic cannula/obturator unit is inserted dorsal to the DDFT, first perpendicular to the limb and then directed distomedially. A similar instrument portal can subsequently be created medially under tenoscopic control. The distal reflection of the DFTS is identified and a wide portal is made into the podotrochlear bursa by division of the palmar aspect of the T-ligament along the dorsal margin of the DDFT using a meniscectomy knife, a banana knife, or a curved beaver blade and arthroscopic scissors. The thickness of this ligament varies depending on the pathology and enlargement of the opening can be achieved more easily using a synovial resector in some cases
what is the biccipital bursoscopy indication (4)?
- septic synovitis,
- lesions of the bicipital tendon and associated synovitis,
- osseous cystlike lesions involving the intermediate tubercle of the humerus
- fragmentation of the lateral tuberosity of the humerus.
Where does the bicipital bursa tenoscopic portal usually enter?
Near the craniolateral margin of the humerus, above the deltoid tubercle.
What positioning is used for bicipital bursoscopy in horses?
Lateral recumbency with the affected limb uppermost.
Describe in detail the biccipital bursa
A distal bursoscopic portal is most commonly used and is located over the craniolateral margin of the humerus, approximately 2 to 3 cm proximal to the deltoid tubercle. The cannula/obturator unit is advanced proximally and axially through the brachiocephalicus muscle and between the humerus and the biceps tendon.
where is the distal bursoscopic portal in the biccipes?
craniolateral margin of the humerus, approximately 2 to 3 cm proximal to the deltoid tubercle
what forms the dorsal, proximal and distal borders of calcaneal bursa?
dorsal border: gastrocnemius tendon,
the proximal border: is the fibrocartilage-covered calcaneal tuber,
distal border: the long plantar ligament forms the distal border.
what are the 3 components of calcaneal bursa
subcutaneous
intertendinous
describe in detail the bursscopy of calcaneal bursa
Bursoscopy is performed under general anesthesia in dorsal or lateral recumbency with the limb extended. Routinely, a distal bursoscopic portal is created distal to the calcaneal insertion of the SDFT medially and/or laterally.241 Entry into the gastrocnemius bursa requires a separate portal proximal to calcaneal tuber and cranial to the gastrocnemius tendon. Specific indications for calcaneal bursoscopy include osteolytic lesions and traumatic fragmentation of the calcaneus associated with sepsis, and injuries of the calcaneal insertions of the SDFT, which result in unstable subluxation of the SDFT from the point of the hock.
Torn components of the SDFT (calcaneal insertions and the SDFT fibrocartilaginous cap) at the point of the hock can result in
intermittent luxation of the SDFT because the calcaneus is pushed through the defect and restricts further permanent, abaxial displacement of the SDFT.
what should be performed in case of intermitent luxation of SDFT in the calcaneus
Transection of these retaining components created a stable luxation that allowed 15 of 19 horses to return to athletic activity - 79%
What condition may affect the gastrocnemius bursa?
Traumatic fragmentation or osteolytic lesions of the calcaneus.
What kind of synovial structures are treated by tarsal sheath tenoscopy?
Tarsal sheath synovioceles.
Describe in detail the surgical access to the tarsal sheath
A central medial tenoscopic portal is created 1 to 2 cm proximal to the sustentaculum tali and allows visualization of both the proximal and distal aspects of the sheath. In the proximal pouch, a choice of entry either craniad or caudad to the mesotenon of the lateral digital flexor tendon (LDFT) is required.
what are the indication of tarsal sheath tenoscopy?
Indications for tarsal sheath tenoscopy include débridement of tendon tears (such as tears of the LDFT), the sustentaculum tali and synovioceles.
What treatment is recommended for recurrent DFTS synoviocoeles?
Open resection or enlargement of synoviocoele communication.
What is proximal suspensory desmopathy (PSD) in horses?
A degenerative condition affecting the suspensory ligament, often causing lameness.
When is surgery indicated for PSD in the forelimb?
When chronic cases do not respond to conservative treatment.
What nerve is excised in forelimb PSD surgery?
The deep branch of the lateral palmar nerve.
How is the horse positioned during forelimb PSD surgery?
In dorsal or lateral recumbency with the affected limb extended.
What type of incision is made for forelimb PSD surgery?
A 3- to 5-cm longitudinal incision.
describe in surgical detail the nevrectomy and fasciotomy of deep branch
This surgical procedure is performed in dorsal or lateral recumbency under general anesthesia with the affected limb extended. A 3- to 5-cm longitudinal skin incision is made lateral to the SDFT, extending from 1 cm distal to the palmarodistal aspect of the accessory carpal bone to the level of the head of the fourth metacarpal bone. The peritendinous fascia is subsequently incised carefully to avoid the underlying neurovascular structures and retracted. The lateral palmar nerve is identified adjacent to thedistal border of the accessoriometacarpal ligament by blunt dissection with a mosquito forceps. The deep branch of this nerve is located either closely adjoined to the lateral palmar nerve or courses towards it in a dorsodistal to palmaroproximal direction. The deep branch is then elevated with a curved mosquito forceps and an as-long-as-possible segment excised. The peritendinous fascia and subcutaneous tissue are closed separately in a simple continuous pattern, followed by routine closure of the skin
What was the success rate of forelimb PSD surgery in a study on 20 horses?
83% of horses returned to full work 2 years postoperatively.
What surgical technique is used for hind limb PSD unresponsive to conservative treatment?
Neurectomy of the deep branch of the lateral plantar nerve combined with fasciotomy.
Why is fasciotomy performed in hind limb PSD surgery?
To decompress the origin of the suspensory ligament, believed to relieve compressive compartment syndrome.
What is avoided during fasciotomy to prevent complications?
The transverse vein and artery at the proximal deep plantar arch.
What complication is associated with hind limb PSD surgery in horses with conformation issues?
Horses with straight tarsal conformation or hyperextension of the MTP joint typically do not become sound.
What are common complications following hind limb PSD surgery?
Damage to the suspensory ligament, seroma formation, curb-like swelling, exacerbation of desmitis, and white hair at the incision site.
What type of atrophy may result from neurectomy of the deep branch of the lateral plantar nerve?
Neurogenic atrophy of muscle fibers in the proximal suspensory ligament.
What experimental treatment has been used for PSD in the hind limb?
Microfractures applied to the proximoplantar cortex of MTIII.
What does the appearance of connective tissue in treated limbs suggest about the microfracture technique?
It may promote tissue healing but lacks significant impact on lameness or MRI findings.
What can SLB lesions cause in horses?
Synovitis of the metacarpophalangeal (MCP) or metatarsophalangeal (MTP) joint.
What is the return-to-work rate for horses after arthroscopic debridement of SLB lesions?
66% of horses returned to equal or greater levels of work.
What is the purpose of debridement in treating SLB lesions?
To remove nonvital tissue and reduce inflammation.
What percentage of Thoroughbred horses raced again after SLB debridement surgery?
65% resumed racing.
What are signs of digital extensor tendon lacerations in horses?
Partial or complete loss of limb protraction, or abnormal limb positioning.
How should a limb with a tendon laceration be initially treated?
It should be stabilized to prevent further damage and ensure the horse’s comfort.
What type of splint is used for flexor tendon lacerations?
A palmar/plantar or dorsal splint or a commercial splint, such as a Kimsey splint.
what is the main goal of surgical repair for flexor tendon lacerations?
To restore tendon gliding function and prevent gap formation between tendon ends.
Which suture patterns are commonly used in flexor tendon repair?
The three-loop pulley and interlocking loop patterns.
What is an advantage of the three-loop pulley suture in tendon repair?
It prevents distraction of the tendon ends under loading.
Why is the interlocking loop pattern recommended for intrathecal tendon repairs?
It has minimal suture material outside the tendon, reducing irritation within the tendon sheath.
What is a disadvantage of carbon fiber implants in flexor tendon repairs?
They may cause persistent lameness due to shear forces with healed tendon tissue.
What are PLLA implants used for in flexor tendon repairs?
They support tendon healing and gradually lose strength over time, mimicking tendon properties.
When is tendon suturing recommended for partial flexor tendon lacerations?
For lacerations involving more than 50% of the tendon to prevent longitudinal splits.
How long should a cast remain on for flexor tendon laceration repairs?
A minimum of 6 to 8 weeks, but no more than 12 weeks.
What additional support is recommended after cast removal for flexor tendon repairs?
A palmar/plantar splint over a modified Robert Jones bandage and caudal shoe extensions.
Why is ultrasonographic monitoring used during tendon rehabilitation?
To assess the healing process and integrity of the tendon repair.
What is the prognosis for flexor tendon injuries in horses?
Guarded, with about 55% of horses returning to athletic performance.
How long is the typical rehabilitation period for flexor tendon lacerations?
A minimum of 8 to 12 months before full athletic function can be resumed.
What factors significantly affect the outcome of flexor tendon lacerations?
The number of structures affected by the injury.
What are common complications of flexor tendon lacerations?
Hyperextension of the MCP/MTP joint, necrotic tendinopathy, synovial sepsis, and joint luxation.
What is a common reason for adhesions and pain after tendon laceration repairs?
Adhesions can form, leading to ongoing pain and potential lameness.
Why is it essential to prevent further trauma to the neurovascular structures in tendon injuries?
To avoid additional damage that could compromise limb function.
What is a potential issue with using autologous tendon grafts in flexor tendon repairs?
Autologous grafts from extensor tendons are not widely used due to poor popularity and effectiveness.
What are the potential effects of tendon sheath involvement in flexor tendon injuries?
ncreased risk of complications, although it doesn’t significantly impact overall prognosis.
How do extensor tendon lacerations typically heal?
They heal remarkably well without the need for tenorrhaphy and respond well to conservative management.
How do extensor tendon lacerations typically heal?
They heal remarkably well without the need for tenorrhaphy and respond well to conservative management.
What should be done if the extensor tendon is lacerated within a tendon sheath?
The area should be lavaged, and sepsis from the tendon sheath must be eliminated.
What type of tissue forms between the tendon ends during healing?
Fibrous scar tissue gradually forms an attachment between the tendon ends.
What can be used to prevent knuckling at the MCP/MTP joint during recovery?
A splint bandage can be applied if required to eliminate knuckling over at the joint.
What can be used to prevent knuckling at the MCP/MTP joint during recovery?
A splint bandage can be applied if required to eliminate knuckling over at the joint
What is a potential complication of extensor tendon lacerations?
Exuberant granulation tissue and sequestrum formation are common complications.
What is the prognosis for horses with extensor tendon lacerations compared to flexor tendon lacerations?
The prognosis is better for extensor tendon lacerations, with 70% to 80% of horses returning to athletic function.
How can stumbling be reduced during the recovery of an extensor tendon injury?
Stumbling can be reduced by shortening the toe of the hoof, rolling the toe of the shoe, or using a Natural Balance type of shoe.
What is the prognosis for racehorses with both the lateral and long digital extensor tendons lacerated in the hind limb?
The prognosis for return to racing is very guarded if both extensor tendons are lacerated.
Figure 84-26. (A) Location of the incision into skin and superficial plantar metatarsal fascia: 4 to 6 cm long, just lateral to the SDFT, and centered over the head of the fourth metatarsal bone (MTIV). (B) Identification of the lateral plantar nerve and its deep branch. (C) The deep branch of the lateral plantar nerve is elevated and a 3-cm section is removed. The deep metatarsal fascia covering the SL is cut adjacent to the MTIV.
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Figure 84-27. Loss of digital extensor function secondary to extensor tendon laceration, resulting in weight bearing on the dorsum of the hoof and phalangeal region.
