Limb amputation and prosthesis

Orthotics and prosthetics by 3D-printing: Accelerating its fabrication flow

Orthoses and socket prostheses are rarely used orthopaedic devices in veterinary medicine. Recently, more pet owners have sought these treatments for pets with orthopaedic conditions. However, veterinarians often lack substantial scientific evidence on device outcomes and may expect high costs, the main limiting factor, if human orthopaedic market prices are assumed. This discrepancy creates an imbalance between pet owners' expectations, veterinarians' recommendations, and actual patient benefits. To address economic constraints and enhance knowledge about these devices, this study used 3D technology-namely 3D scanning and printing via fused deposition modelling-to design, modify, and manufacture orthoses and socket prostheses for ten patients, including nine dogs and one calf. An equation was devised and applied to all printed devices to streamline the resizing process for sockets and orthoses. The 3D-printed devices were fitted to the patients, and their adaptation was assessed using three novel scales based on prior scientific literature in the small animal orthopaedic field. The orthoses were well-tolerated, with successful and straightforward adaptation. Although socket prostheses were tolerated, the dogs' adaptation was suboptimal, while the calf demonstrated excellent and immediate adaptation.

Biomechanical Tests on Long-Bone Elliptical Medullary-Canal Endoprostheses for Limb Salvage in Dogs

Simple Summary

Currently, more owners look for offering a better quality of life to their pets. In fact, the complete limb amputation seems to be the last option considered by pet owners in surgeries to save their pets’ lives. Although this field is under development in veterinary medicine, we believe that 3D-printed implants for this market sector will improve the advancement in its research by reducing production costs. This would allow the pet owners to select this solution without large expenses, allowing at the same time, advances in this field. For this purpose, mechanical tests have been carried out on implants printed in a high-performance plastic that resembles the resistance of metals—that are traditionally used in veterinary surgery—and the properties of dogs’ bones as well. The results obtained have confirmed that the implants could withstand the dog weight in its different gaits, although further comparative studies on the effect of rotation forces applied during the animal’s change of direction (evaluated at different paces) are required to confirm their suitability.

Abstract

Exo-endoprosthesis is a limb salvage procedure poorly described for animals, as only expensive metal devices have been used so far. Currently, additive manufacturing (AM) can make this type of implant affordable by exploring a wide new range of materials. However, safety factors should be considered and could be related to kinetic and kinematic studies of canine natural gaits. The suitability of a novel inner part of an exo-endoprosthesis manufactured by fuse deposition modeling (FDM) was assessed for long canine bones with an elliptical medullary canal. Polyether ether ketone (PEEK) was the material used as an alternative to metal for veterinary traumatology. Poisson’s ratio of 3D-printed PEEK material and ex vivo mechanical tests of the customized endoprosthesis were performed for the evaluation. The customized endoprostheses had promising outcomes for the radii of 20 kg dogs. Quasistatic mechanical tests of bone-inserted endoprostheses—pure compression tests—reached a maximum force of 1045.0 ± 78.0 N. In fatigue tests, the samples reached 500,000 cycles without failure or detriment to their quasistatic results. These outcomes surpass the natural weight-bearing of dogs, even during a galloping pace. Furthermore, torque tests with different adhesives were performed to obtain reference data for future assessments comparing with natural dog movements.

Indications for and outcomes of limb amputation in goats and sheep

OBJECTIVE To characterize indications for and clinical outcomes of limb amputation in goats and sheep. DESIGN Retrospective case series and observational study. ANIMALS Goats (n = 15) and sheep (7) that underwent partial or complete limb amputation at the University of California-Davis Veterinary Medical Teaching Hospital from January 1, 1985, through December 31, 2015. PROCEDURES Medical records of qualifying goats and sheep were reviewed and data extracted regarding signalment, use of animal, characteristics of the amputated limb, duration of hospitalization, outcome, and surgery-associated complications. The Fisher exact test was performed to compare postsurgical complication rates between various groups. RESULTS Reasons for limb amputation included trauma (ie, fracture, dog bite, and wire-fence injury) and infectious or degenerative disease (ie, osteomyelitis and osteoarthritis). Median (range) hospitalization period for goats and sheep was 7.5 days (1 to 63 days) and 8 days (3 to 20 days), respectively. Most (7/9) of the postsurgical complications were noticed > 2 months after amputation and included uncoordinated gait, tendon breakdown and laxity of the contralateral limb, chronic lameness, surgical site infection, chronic intermittent pain, and angular limb deformity. No association was identified between postsurgical complication rate in goats and body weight category (< 20 vs ≥ 20 kg [44 lb]), age category (< 2 vs ≥ 2 years), and amputated limb type (forelimb vs hind limb). CONCLUSIONS AND CLINICAL RELEVANCE Clinical outcomes for goats and sheep following limb amputation varied and were seemingly case dependent. Amputation should be considered when preservation of the whole limb is not possible. Veterinarians should advise owners that limb amputation may result in various complications and recommend aftercare treatment such as physiotherapy.

Frakturen von Gliedmaßenknochen bei 32 kleinen Wiederkäuern – Methoden und Ergebnisse der Behandlung

Gegenstand: Retrospektive Auswertung der Daten 32 kleiner Wiederkäuer, die zwischen 2001 und 2014 wegen Gliedmaßenfrakturen behandelt wurden. Material und Methode: Die Daten wurden bezüglich Spezies, Rasse und Alter der Tiere, Alter, Lokalisation und Typ der Fraktur sowie Art (konservativ: mittels PVC-Halbrohren oder Cast; chirurgisch: diverse Osteosynthesetechniken oder Amputation der Gliedmaße) und Erfolgsquote der Behandlung analysiert. Ergebnisse: Die 16 Ziegen und 16 Schafe (18 männlich, 14 weiblich) hatten ein mittleres Alter von 1,5 Jahren und ein mittleres Körpergewicht von 37,8 kg. Die Fraktur war bei 23 Tieren (71,8 %) 1–6 Tage alt, bei fünf Tieren (15,6 %) 12–60 Tage und in vier Fällen (12,5 %) fehlte eine Angabe. Von den 35 Frakturen (Mehrfachfrakturen bei drei Tieren) befanden sich 20 (57,1 %) an der Hinter- und 15 (42,9 %) an der Vorderextremität. Am häufigsten war das Os femoris (28,6 %) frakturiert, gefolgt von Radius und Ulna (22,8 %), Metatarsal- (20,0 %) und Metakarpalknochen (14,3 %). Bei 17 Tieren (63,0 %) erfolgte eine konservative und bei 10 Tieren sowie einem zunächst erfolglos konservativ behandelten Schaf (n = 11, 40,7 %) eine chirurgische Therapie. Fünf Patienten wurden aufgrund weiterer Erkrankungen und schlechter Prognose nicht behandelt. Eine Abheilung ließ sich bei 94,1 % der konservativ behandelten und 81,9 % der chirurgisch therapierten Frakturen erzielen. Bei sechs Tieren (22,2 %) traten bei bzw. nach der Behandlung Komplikationen auf. In vier Fällen kam es zur Abheilung, zwei Tiere wurden letztlich euthanasiert. Einflüsse von Alter bzw. Körpergewicht der Tiere und Alter der Fraktur auf den Therapieerfolg waren nicht nachweisbar. Schlussfolgerung und klinische Relevanz: Die Erfolgsquote von 92,6 % (n = 25) bei konservativer und chirurgischer Versorgung führt zur klaren Empfehlung, vor allem konservative Frakturbehandlungen bei Schafen und Ziegen auch in der Praxis vorzunehmen. Hierfür eignen sich insbesondere Frakturen von Röhrbeinen und Phalangen, die sich oft bereits durch sorgfältige und behutsame Palpation gut diagnostizieren lassen. Dagegen stellt bei Frakturen proximaler Knochen die chirurgische Behandlung die erste Wahl dar.

Design, Synthesis, and Antimicrobial Evaluation of a Novel Bone-Targeting Bisphosphonate-Ciprofloxacin Conjugate for the Treatment of Osteomyelitis Biofilms

Osteomyelitis is a major problem worldwide and is devastating due to the potential for limb-threatening sequelae and mortality. Osteomyelitis pathogens are bone-attached biofilms, making antibiotic delivery challenging. Here we describe a novel osteoadsorptive bisphosphonate-ciprofloxacin conjugate (BV600022), utilizing a "target and release" chemical strategy, which demonstrated a significantly enhanced therapeutic index versus ciprofloxacin for the treatment of osteomyelitis in vivo. In vitro antimicrobial susceptibility testing of the conjugate against common osteomyelitis pathogens revealed an effective bactericidal profile and sustained release of the parent antibiotic over time. Efficacy and safety were demonstrated in an animal model of periprosthetic osteomyelitis, where a single dose of 10 mg/kg (15.6 μmol/kg) conjugate reduced the bacterial load by 99% and demonstrated nearly an order of magnitude greater activity than the parent antibiotic ciprofloxacin (30 mg/kg, 90.6 μmol/kg) given in multiple doses. Conjugates incorporating a bisphosphonate and an antibiotic for bone-targeted delivery to treat osteomyelitis biofilm pathogens constitute a promising approach to providing high bone-antimicrobial potency while minimizing systemic exposure.