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.
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.
VetBooks
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.
