Kevin A. Drygas

Background: Achieving complete surgical margins can be challenging for tumors involving the distal extremities due to limited surrounding soft tissue and the proximity of functionally important structures. Incompletely excised tumors may require adjuvant radiation therapy to treat suspected residual microscopic disease. Yttrium-90 phosphate hydrogel (IsoPet^®) is an emerging injectable radiation modality that delivers localized beta radiation to a tumor bed or surgical margin. Case Description: An eight-year-old neutered male Bullmastiff was evaluated by the referring veterinarian for firm subcutaneous masses developed along the right pelvic limb. Fine-needle aspiration was initially suggestive of an inflammatory process; however, subsequent punch biopsies identified Grade II soft tissue sarcoma. The patient was referred for surgical oncology evaluation. Four right pelvic limb masses and the right popliteal lymph node were surgically excised. Histopathological examination of the excisional specimens identified poorly differentiated carcinoma involving the excised masses, with metastatic involvement of the right popliteal lymph node and incomplete surgical margins. Adjuvant Y-90 hydrogel was elected following complete surgical wound healing. On 20 November 2025, 8.46 mCi (313 MBq) of Y-90 phosphate hydrogel in a total volume of 4.7 mL was administered through 66 peri-incisional and incisional injections distributed across the previous right pelvic limb surgical beds using a grid-based technique. The procedure was completed without complications. Post-treatment follow-up demonstrated satisfactory wound healing, with only mild transient appetite reduction and minimal localized tissue irritation. After surgery plus adjuvant Y-90, no clinically detectable local recurrence was identified at the treatment sites during the 120-day documented follow-up period. Seventy-four days following Y-90 hydrogel treatment, computed tomography performed for persistent otic disease identified an aggressive osteolytic lesion involving the right C5 vertebra with extradural spinal cord compression. The relationship between this lesion and the previously treated pelvic limb neoplasia could not be definitively established. Despite the subsequent development of this cervical lesion, no clinically detectable recurrence was documented at the original treatment limb sites. This finding is an observation after combined surgery and Y-90, not evidence of Y-90-specific efficacy. The patient was subsequently managed supportively and was euthanized by the referring veterinarian approximately four months after identification of the cervical lesion. Conclusion: This single case demonstrates that peri-incisional Y-90 phosphate hydrogel could be administered to multiple distal pelvic-limb surgical beds after limb-sparing excision. The procedure was well tolerated. No clinically detectable local recurrence was identified at the treated sites during the 120-day documented follow-up period. Because gross disease had already been removed and there was no comparator, these observations cannot establish the independent efficacy of IsoPet^®. Prospective studies are needed.

This prospective case series evaluated the short-term outcomes following percutaneous cementoplasty as the sole palliative treatment for appendicular osteosarcoma in 10 dogs. Synthetic self-hardening calcium phosphate bone substitute was injected into the osseous defect under fluoroscopic guidance after curettage of the bone tumor. Clinician assessment included a numerical rating score for lameness, offloading, and ease of lifting the contralateral limb as well as the 4A-VET postoperative pain scale. Owner assessment was obtained using three descriptive questionnaires, the Helsinki Chronic Pain Index (HCPI), the Canine Brief Pain Inventory (CBPI) and the Canine Symptom Assessment Scale (CSAS). Measures were recorded preoperatively and at 2, 4, 8, and 12 weeks following surgery. Early improvement in the 4A-Vet score was noted at the 2-, 4-, 8-, and 12-week time points for all major pain and function metrics. Similarly, the CBPI pain severity and interference scores demonstrated early postoperative improvement during the 2- and 4-week time points with partial attenuation by 8 and 12 weeks. Panting, difficulty sleeping, whining/moaning, and lack of appetite were significantly reduced when assessed via the CSAS. Cementoplasty as a monotherapy, affording early pain relief and improved structural integrity, supports its role as a palliative limb-preserving option for dogs unable to undergo amputation.

This prospective case series evaluated the short-term outcomes following percutaneous cementoplasty as the sole palliative treatment for appendicular osteosarcoma in 10 dogs. Synthetic self-hardening calcium-phosphate bone substitute was injected into the osseous defect under fluoroscopic guidance after curettage of the bone tumor. Clinician assessment included a numerical rating score for lameness, offloading, and ease of lifting the contra-lateral limb as well as the 4A-VET post-operative pain scale. Owner assessment was obtained using three descriptive questionnaires, the Helsinki Chronic Pain Index (HCPI), the Canine Brief Pain Inventory (CBPI) and the Canine Symptom Assessment Scale (CSAS). Measures were recorded preoperatively and at 2-, 4-, 8-, and 12-weeks following surgery. Early improvement in the 4A-Vet score was noted at the 2-, 4-, 8-, and 12-week time points for all major pain and function metrics. Similarly, the CBPI pain severity and interference scores demonstrated early postoperative improvement during the 2- and 4-week time points with partial attenuation by 8- and 12-weeks. Panting, difficulty sleeping, whining/moaning, and lack of appetite were significantly reduced when assessed via the CSAS. Cementoplasty as a monotherapy, affording early pain relief and improved structural integrity, supports its role as a limb-sparing option for dogs unable to undergo amputation.

Objective—To evaluate the effect of cold compression therapy (CCT) on postoperative pain, lameness, range of motion of the stifle joint, and swelling following tibial plateau leveling osteotomy (TPLO) in dogs. Design—Randomized, blinded, placebo-controlled clinical trial. Animals—34 client-owned dogs with unilateral deficiency of a cranial cruciate ligament undergoing TPLO. Procedures—Dogs were assigned to 2 groups. Group 1 (n = 17 dogs) received CCT in the 24-hour period following TPLO. Group 2 (n = 17 dogs) received no CCT. Degree of lameness, range of motion, and circumference of the stifle joint were measured before surgery and 1,14, and 28 days after surgery. A modified composite Glasgow pain scale, visual analogue scale, and pain threshold score were used to evaluate signs of pain before surgery and 1,14, and 28 days after surgery. Logistic regression and linear regression analysis were used to compare the measured variables. Results—No complications were observed, and all dogs tolerated CCT. Use of CCT resulted in lower values for the visual analogue scale and Glasgow pain scale and lower pain threshold scores; lower lameness scores; less swelling; and an increased range of motion 24 hours after surgery. At 14 days after surgery, there were no significant differences between groups. At 28 days after surgery, too few data sets were available for comparison. Conclusions and Clinical Relevance—CCT decreased signs of pain, swelling, and lameness and increased stifle joint range of motion in dogs during the first 24 hours after TPLO.

Objective— To report surgical planning, technique, and long‐term outcome of custom transcutaneous tibial implants used to restore ambulation after bilateral pelvic limb amputation in a dog.Study Design— Case report.Animals— A 4‐year‐old, 25.5 kg, female spayed, Siberian Husky.Methods— Computed tomographic scans of the pelvic limbs were used to build sterolithographic models of the remaining tibia after bilateral amputation of the distal aspect of the tibiae. The sterolithographic models facilitated fabrication of implants that would replace the missing distal segments of the tibiae. Custom implants were surgically placed in both limbs.Results— Assisted ambulation was restored immediately postoperatively and unassisted locomotion occurred at 7 days. At 14 months, aseptic loosening of the right implant occurred, it was removed and a 2nd transcutaneous implant was fabricated and implanted. At 26 months after initial surgery and 17 months after revision of the right implant, function is restored at a walk, trot, and run.Conclusion— Based on over a 2‐year follow‐up, transcutaneous tibial implants allowed for restoration of locomotion.Clinical Relevance— Transcutaneous tibial implants offer a potentially viable treatment option for restoring ambulation after amputation of the distal aspect of the tibiae in the dog.