Managing long bone fractures in large ruminants presents significant clinical challenges (Jain et al., 2023), especially in field conditions. Despite their high economic value and excellent innate bone healing capabilities, conventional fixation methods often fall short. While standard Steinmann pinning maintains axial alignment and resists bending, it fails to counteract rotational or shear forces, frequently resulting in complications like delayed union or muscle atrophy. Intramedullary Interlocking Nailing (IILN) addresses these limitations by securing the nail with locking bolts, combining superior bending resistance with essential rotational stability. This system can operate in a static mode for rigid stabilization or a dynamic mode to allow controlled micromotion that enhances callus formation. Given the scarcity of comparative data in bovine orthopaedic, this clinical study evaluates and compares the efficacy of Steinmann pinning versus IILN for repairing bovine tibial diaphyseal/metaphyseal fractures. The study tracks clinical and radiographic parameters both pre-and post-surgery. Ultimately, it aims to assess and compare the two surgical techniques regarding their impacts on lameness alleviation, overall bone healing and post-operative complication rates.

This study was conducted during the year 2019 to 2022 at Department of Veterinary Surgery and Radiology, Veterinary College Bidar, Karnataka to comparatively study the effect of two surgical techniques on clinical and radiographic parameters before and after tibia fracture repair in Bovine.
 
Selection of animals and design of study
 
Bovine presented to Veterinary Clinical Complex, Veterinary College, Bidar with the history and clinical signs of tibial fracture were used for study after detailed physical, orthopaedic and radiographic examination. Of the animals screened, twelve animals with tibial fracture, based on the type of fracture and the method used for repair, six animals were chosen and separated into two groups, each with no other concurrent illnesses. Details of the chosen patient animals are elaborated in Table 1 for Steinmann pinning and Table 2 for IILN.




 
Surgical preparation and procedure
 
Pre-operative preparation
 
Animals underwent a 12-hour fast from food and water. The surgical site-extending from the mid-thigh to the hock-was shaved and aseptically prepared using chlorhexidine, surgical spirit and 7.5% povidone iodine. Pre-medication included intramuscular injections of amoxicillin-sulbactum (10 mg/kg) and tolfenamic acid (2 mg/kg).
 
Anaesthesia protocol
 
For both groups as mentioned in Table 3, anaesthesia was initiated with a 5% guaifenesin intravenous drip (50 mg/kg), followed by restraint in lateral recumbency. Induction was achieved with a tiletamine-zolazepam bolus (3 mg/kg), while maintenance was sustained via isoflurane (1-2%) using large animal inhalant anaesthetic machine (Mallard Medical Model 8300C, Redding CA, US).


 
Surgical approach
 
The tibia was accessed through a cranio-medial incision between the stifle and hock. Following the incision of skin and fascia, the tibialis anterior and flexor digitorum profundis muscles were retracted to expose the bone. Finally, fracture segments were identified and brought into apposition (Image 7 and 11) for repair.
 
Group I (Steinmann pin)
 
The procedure involves proper animal positioning (Image 4) followed by the normograde creation of a tunnel using an awl (Image 5). A Steinmann pin is then inserted normograde (image 6) directly into the tibial medullary cavity to achieve properly aligned fracture fragments.
 
Group II (IILN in bovine)
 
This technique involving specialized instruments as shown in from Image 1 to 3 and begins with normograde pre-nail insertion of a pin (Image 8), followed by the insertion of an intramedullary nail with an attached jig in the proximal fragment (Image 9). Self-tapping bolts (Image 10) are then placed to secure the structure, resulting in aligned fractured fragments stabilized by static IILN placement (Image 11).






















 
Clinical observations
 
Weight bearing and lameness grading
 
Functional limb usage was assessed through weight bearing and lameness scoring. Lameness grading was performed according to the scale described by Cook et al., (1999), ranging from 0 to 5:
 
Grade 0: No observable lameness.
 
Grade 1: Intermittent, mild weight-bearing lameness with minimal gait alteration.
 
Grade 2: Consistent, mild weight-bearing lameness with slight gait change.
 
Grade 3: Moderate weight-bearing lameness with obvious gait abnormality and head bobbing.
 
Grade 4: Severe weight-bearing lameness with toe-touching only.
 
Grade 5: Non-weight-bearing lameness.
       
This scoring system was used to objectively evaluate clinical improvement over time.
 
Post-operative complications
 
All animals were monitored for intra-operative and post-operative complications. Any adverse events observed during the study period were recorded and documented systematically in each group.
 
Radiographic evaluation
 
Radiographic examination of the fractured tibia was performed in two orthogonal views: medio-lateral and antero-posterior, including adjacent joints. Radiographs were taken pre-operatively and at each post-operative interval. Fracture healing was assessed based on implant position, callus formation and degree of union of fracture fragments.
 
Post-operative care and management
 
Post-operative care included administration of:
 
• Antibiotic: Amoxicillin sodium + sulbactam sodium @ 10 mg/kg body weight (intramuscular).
 
• Anti-inflammatory drug: Tolfenamic acid @ 2 mg/kg body weight (intramuscular).
       
Both medications were administered for 8-10 days post-operatively. Surgical wounds were dressed daily under aseptic conditions and antiseptic cream lorexane was applied. Skin sutures were removed between 12-14 days post-surgery.

Statistical analysis
 
Data were statistically analyzed using student’s t-test as described by Snedecor and Cochran (1989). Results were expressed as mean±standard error (SE) with a sample size of n = 6. Differences were considered statistically significant at p≤0.05 and highly significant at p≤0.01.

The present study was carried out on 12 bovine, all with tibia fracture. The 12 bovine were randomly divided into two groups, one group patients were treated with Steinmann pin and were compared with group treated with intramedullary interlocking nail. All the animals included in the study were females.
 
Clinical observations
 
All animals were evaluated at predetermined intervals, including immediately post-operative (day 0) and on the 30^th, 45^th and 60^th post-operative days.
 
Intra-operative complications
 
There were no intra-operative complications recorded during this study period.
 
Post-operative complications and their treatment
 
In Group I, one animal (16.67%) experienced Steinmann pin migration on day nine post-operation (Radiogrpah 19 and Radiogrpah 20). In Group II, one animal (16.67%) suffered permanent peroneal nerve injury and paresis caused by pressure ischemia during prolonged recumbency, which failed to improve despite medical treatment and physiotherapy.
 
Radiographic observations
 
Pre-operative radiographs (Radiograph 1 to Radiograph 12) taken for all cases in both the groups were compared to post-operative radiographs taken immediately after operation to check implant position and fragment alignment. On 30^th, 45^th and 60^th post-operative day radiographs were taken to determine implant position, fragment alignment and fracture healing.
























       
Lateral view on 9^th post-operative day in case 2 of group I showing migration of pin from distal fragment.
       
Lateral and cranio-caudal view on 30^th post-operative day in case 6 of group II, fragment alignment was disturbed and proximal bolt got dislodged and bent with mild callus formation close to the fracture site.
       
The demographic characteristics and fracture profile of bovines with tibial fractures (Image 12) shows that tibial fractures were most prevalent in 2-year-olds (33.33%), aligning with reports by Rao et al., (1999) and Hansda et al., (2012). The female-only demographic reflects economic livestock patterns noted by Singh et al., (1983) and Patil et al., (2018).


 
Key findings
 
• Etiology: Road accidents (41.67%) and stone trauma (33.33%) predominated, matching patterns by Kumar et al. (2013).
 
• Fracture type: Long oblique fractures were most frequent (41.67%), supporting biomechanical principles described by Hulse and Hyman (2003).
 
• Location: Most fractures occurred in the diaphysis (83.33%) due to mechanical stress, consistent with Aithal et al. (1999) and Hansda et al., (2012).
 
Clinical observations
 
Lameness grading as recorded in Table 4 depicted Group I animals showed steady improvement, except for one pin migration (Case-3). In Group II (IILN) animals demonstrated rapid lameness reduction due to stable fixation, though cases of bolt bending and fatal peroneal nerve paresis occurred. Results align with Endo et al., (1998) and Singh et al., (2007) regarding stability.


       
Radiographic evaluation with radiographs taken before operation numbered from radiograph 1-6 in group I and from 7-12 in group II at different post-operative intervals.
       
Fracture healing is a multi-stage regenerative process involving inflammation, soft callus formation, hard callus mineralization and remodelling. Ackerman and Silverman (1978) emphasized using radiography to evaluate union, focusing on cortical/medullary continuity and callus mineralization. Whelan et al., (2002) specifically recommended measuring callus bridging across four cortices as a reliable healing metric.
       
Immediate post-operative assessments (Radiograph 13 to Radiograph 18) in this study confirmed secure implant positioning and fragment stability, consistent with findings by Roush (1992) and Beale and McCally (2020). By day 30, radiographs showed fading fracture lines and dense periosteal callus, correlating with reports by Umarani and Ganesh (2002) and Singh et al., (2008) regarding fracture site obliteration. Reems et al., (2003) noted bridging callus typically appears within 4-6 weeks in mature patients, while Guiot and Dejardin (2011) defined clinical union as bridging callus exceeding 50% of the tibial diameter.


















       
By day 60, fracture lines were completely obliterated by radio-dense callus, indicating radiographic union as described by Anderson et al., (1995). Denny and Butterworth (2000) noted that while callus starts within two weeks, clinical healing is often established by six weeks.
Comparison of fixation methods revealed:
 
• Fracture fixation by steinmann pin: Showed earlier and more extensive periosteal callus due to site instability, agreeing with Anderson (1966). The Steinmann pins used in this study were trocar end of proximal end for easy lodging into the distal epiphysis which avoided reaming of intramedullary cavity.
 
• Static fixation (IILN): Demonstrated negligible early callus and progressive healing with minimal callus by day 60, supported by Duhautois (2003) and Raghunath and Singh (2008). Singh et al., (2007) also noted cortical and medullary continuity by the fourth month with static IILN.
       
Ultimately, while the Steinmann pin group (Group I) showed earlier callus formation, union rates across all groups were equivalent by day 60.
 
Post-operative complications
 
Group I (Steinmann pin): One animal (16.67%) experienced (Radiograph 19) pin migration from the tibial tuberosity on day nine, a complication previously noted by Kumar et al., (2025) and Yadav et al., (2006). Two animals developed post-operative edema, which Hulse and Johnson (1997) describe as an expected inflammatory response.
 
Group II (IILN): One animal suffered peroneal nerve injury and permanent paresis due to prolonged recumbency and pressure ischemia. Another case showed proximal bolt bending and dislodgement by day 30 (Radiograph 20 and 21). These findings align with Duhautois (2003) and Raghunath and Singh (2008), who documented complications like implant failure, screw loosening and malunion. Additionally, Ikem et al., (2007) attributed screw loosening to osteoporosis and noted risks of delayed union.
 
Physiological parameters
 
Kelly (1984) opined that physiological parameters are elevated when animals are under stress due to trauma, anaesthesia and surgery. The increase in physiological parameters might be attributed to release of mediators of inflammation viz.,prostaglandins, bradykinins and interleukins and stress due to fracture, anaesthesia and surgery and change of environment. Agnihotri (2007) recorded clinical parameters such as respiratory rate, pulse rate and rectal temperature pre and post-operatively and reported an increase in rectal temperature on 1^st post-operative day followed by its decrease. However, the author did not find any significant variation in respiratory and pulse rate. Jawre (2012) evaluated different techniques of internal fixation during fracture healing in calves and reported non-significant difference in temperature, pulse rate and respiratory rate at different time intervals.
 
Biochemical evaluation
 
Serum calcium levels rose significantly by the 30^th and 45^th post-operative days, staying within high normal limits, consistent with Pandey and Udapa (1981) and Vasantha (1991). However, Singh et al., (1976) noted that calcium levels do not correlate with fracture healing. Serum phosphorus similarly peaked by day 45 while remaining within physiological limits, matching Pandey and Udapa (1981), though Vasantha (1991) and Prachasilpchai et al., (2003) observed non-significant changes. Serum alkaline phosphatase (ALP) increased significantly in all groups through day 60, exceeding normal limits during days 30-45. This rise reflects osteogenic cell proliferation, as identified by Pritchard (1952). While Manjulkar (2000) and Umarani and Ganesh (2002) saw early declines in ALP, Kumar et al., (1999) and Zama et al., (1999) reported sustained elevations throughout healing.
       
A search of the literature reveals a distinct paucity of data regarding their comparative evaluation in clinical bovine cases. This study was designed to evaluate these two techniques in  bovines to contrast a traditional method that permits micro-motion and extensive secondary bone healing (Steinmann pin) against a rigid, static fixation system (IILN) that ensures immediate fragment stability, thereby evaluating their specific impact on callus architecture, physiological stress and implant-related complications under large-animal loading conditions.

Female Bovine and adult animals (56.56%) showed a higher fracture incidence, particularly during the monsoon season. Static IILN allowed for earlier weight bearing than dynamic IILN or Steinmann pins. While physiological and biochemical parameters offered limited diagnostic value, radiographic evaluation confirmed that both pinning and nailing provided adequate stabilization and progressive healing.

The present study was supported by Veterinary College, Bidar, KVAFSU, Bidar.
 
Disclaimers
 
The views and conclusions expressed in this article are solely those of the authors and do not necessarily represent the views of their affiliated institutions. The authors are responsible for the accuracy and completeness of the information provided, but do not accept any liability for any direct or indirect losses resulting from the use of this content.
 
Informed consent
 
All animal procedures for experiments were approved by the Committee of Experimental Animal Care and Handling techniques were approved by the University of Animal Care Committee.

The authors declare that there are no conflicts of interest regarding the publication of this article. No funding or sponsorship influenced the design of the study, data collection,  analysis, decision to publish, or preparation of the manuscript.