Evaluation of fracture healing following repair of orthopaedic complications in dogs (Radiographic and Haemato-biochemical)

Introduction

The primary aim of fracture treatment is to restore the function of the injured limb as soon as possible with minimal complications (Shahar, 2000). It is important to recognize early signs of complications in fracture consolidation, which allows for early correction of the problem and increases the chances of success (Jackson and Pacchiana., 2004). In the present paper the repair of complications was done and their outcome was evaluated based on radiographic and haemato-biochemical parameters.

Materials and Methods

The present study was conducted on 17 clinical cases of dogs with orthopaedic complications presented to the Department of Veterinary Surgery and Radiology, NTR College of Veterinary Science (NTR C.V.Sc), Gannavaram. The complications were managed through conservative treatment in group I, whereas in Group II, they were managed through revision surgeries and the outcome was evaluated. Radiographic evaluation of fracture healing was by obtaining standard lateral and cranio-caudal views, while ventro-dorsal views were obtained for pelvic fractures. Follow-up radiographs were obtained periodically to evaluate fracture healing based by assigning the fracture healing scores (0-3) as recommended by (Cook et al., 1999)

No evidence of healing, failure (The term failure could not be adopted during the early periodic intervals).

Hematological parameters including haemoglobin (Hb), total erythrocyte count (TEC), packed cell volume (PCV), erythrocyte sedimentation rate (ESR), total leucocyte count (TLC), and differential leucocyte count (DLC) were estimated. The serum was analyzed for calcium, phosphorus, alkaline phosphatase (ALP), lactate dehydrogenase (LDH), creatine phosphokinase (CPK), and C-reactive protein (CRP).

Results and Discussion

In group I, the after correction through traction and counter traction, the loss of reduction of fracture fragments was corrected (Fig 1 The progress of radiographic healing was assessed and the details of fracture healing scores were given in table 2 and 3 in groups I and II respectively. The mean ± SE radiographic healing scores at different times intervals in both the groups were given in table no. 4. In Group I, the mean score decreased significantly (p < 0.05) from 2.28 ± 0.36 on the preoperative day to 0.43 ± 0.43 by the 60th postoperative day, indicating progressive fracture healing. A significant reduction was observed between all early intervals (preoperative, 15th POD, and 30th POD), while the differences among later intervals (30th, 45th, and 60th POD) were not significant, suggesting stabilization of healing. In Group II, the mean score also showed a significant (p < 0.05) reduction from 3.00 ± 0.00 preoperatively to 0.67 ± 0.21 at the 60th postoperative day. The decrease was gradual and statistically significant across most intervals, although no significant difference was observed between the 45th and 60th POD, indicating a plateau phase of healing. Overall, both groups demonstrated progressive radiographic healing characterized by a transition from inappropriate or absent healing (scores 2-3) during early intervals to appropriate progression and near-complete healing (scores 0-1) during later postoperative periods.

Between the groups, a significant difference (p < 0.05) was observed during the preoperative day and 15th POD, with Group II showing higher (worse) scores compared to Group I. However, no significant difference was observed during later intervals (30th, 45th, and 60th POD), indicating comparable healing outcomes in both groups over time. Overall, both groups demonstrated progressive radiographic healing characterized by a transition from inappropriate or absent healing (scores 2-3) during early intervals to appropriate progressio

Mean ± SE 3 ± 0 2 ± 0.45 1.17 ± 0.17 0.83 ± 0.17 0.67 ± 0.21 *Radiographic evaluation was done for n=6, as three animal (case-7,8,9) had undergone limb amputation and near-complete healing (scores 0-1) during later postoperative periods. Uhthoff et al. (2006) [31] considered closure of the fracture gap and the formation of an external bridging callus as key radiographic indicators of progress under normal physiological healing. Denny and Butterworth (2006) [6] suggested that when expected radiographic evidence of bone healing was absent, orthopaedic clinicians should suspect the presence of complications, including delayed union, non-union, malunion, osteomyelitis, fracture disease, fracture associated sarcoma or fat embolism. Menghini et al. (2023) [20] defined fracture union as the presence of bridging callus across at least three cortices and recommended serial radiographic examinations to assess healing progression and detect complications. Slunsky et al. (2017) [27] recommended survey radiography as an essential tool for monitoring fracture healing and detecting early signs of implant related complications. The details of various hematological parameters estimated were given in table. 5 The values of haemoglobin and TEC were lesser preoperatively which tended to increase non-significantly in group I, but significantly (P<0.05) in group II up to the 60 th POD. The values of PCV increased non significantly in group I and significantly (P<0.05) from preoperative to the 60 th POD. Based on the above three values, in the present study all the animals in group II had considerable anaemia, when compared to group I. The ESR values varied non-significantly from preoperative to the 60 th POD in group I. In group II, the values were the highest on preoperative day, which decreased significantly (P<0.05) and reached normal value by the 60 th POD. The difference between the groups was also significant at all time intervals except on 60 th POD. The TLC values varied non-significantly within the normal physiological ranges in group I. In group II, the highest values were recorded on preoperative day and decreased significantly (P<0.05) by the 60 th POD and reached normal levels. The difference between the groups was also significant on preoperative, 15 th and 60 th POD. The details of differential leucocyte values were furnished in table no. 5. [30] also reported anaemia with decreased Hb, PCV, and TEC in dogs with chronic inflammatory, traumatic, or orthopaedic diseases. The authors considered anaemia to compromise tissue oxygen delivery, adversely affecting the fracture healing and bone regeneration following orthopaedic procedures. The postoperative anaemia without any regenerative response can be attributed to acute blood loss during or after surgery (Cowgill, 2003) [4] . Foy et al. (2015) [9] reported that in cases of prolonged orthopaedic complications, limited iron availability was responsible for the reduced hemoglobinization of reticulocytes. Meléndez-Lazo et al. (2015) reported that osteomyelitis or implant-associated complications suppressed erythropoiesis and impaired iron utilization, resulting in an inadequate reticulocyte response relative to the degree of anaemia, confirming the concept of anaemia of inflammation in dogs with chronic orthopaedic complications. Persistent lymphopenia is thought suggestive of ongoing inflammation, infection, or systemic stress, seen in dogs with implant infections or delayed bone healing (Stokol, 2015) [28] . The higher preoperative values of ESR were observed in group II that reached normal values towards the end of 60 th POD in the present study. In group I, the values remained normal at all the time intervals. Khan et al. (2011) [13] reported that the erythrocyte sedimentation rate (ESR) increased during inflammatory and infectious conditions and reflected the acute inflammatory response associated with tissue injury. The authors noted that ESR values gradually returned toward normal as the inflammatory process subsided.

The details of various serum biochemical parameters estimated in the present study are given in Table 6.

Mukhopadhyay et al. (2011) [21] recommended that assessment of biochemical parameters such as alkaline phosphatase, calcium, and phosphorus helped in monitoring the progress of fracture healing over shorter time intervals. Paskalev et al. (2005) [23] suggested that prolonged elevation of bone-related enzymes could indicate altered bone turnover or impaired fracture healing. In the present study, there were no significant changes in the serum calcium and phosphorus values in both groups. Meller et al. (1984) [19] and Hegade et al. (2007) [11] also reported only transient changes in the calcium levels during facture healing. Contrary to this finding, Duffy et al. (2018) [7] observed hypocalcemia in dogs with chronic bone disease, reflecting inflammatory bone pathology and osteoblastic activity. Chaurasia et al. (2019) [2] explained that serum calcium levels temporarily decreased during early healing due to deposition of minerals at the fracture site and later increased as bone repair advanced. The localized disturbances in mineral metabolism contributed to impaired callus formation, although the serum calcium and phosphorus levels remained within reference ranges (Gieling et al. 2019) [10] and (Marshall et al. 2022) [17] . Elevated preoperative values of CRP were observed in both the groups, which gradually decreased significantly at different time intervals in both the groups. The postoperative C-reactive protein (CRP) was a more sensitive and responsive indicator of surgical infection and inflammation than the total white blood cell (WBC) count (Sumalai et al., 2025) [29] . The serum C-reactive protein (CRP) concentrations increase rapidly following fractures and orthopaedic surgical procedures in dogs, reaching peak levels during the early postoperative period and gradually decline as healing progresses (Yamamoto et al., 1992) [32] . In normal healing, CRP levels [3] . Lofqvist et al. (2018) [15] reported that, CRP levels progressively declined as postoperative inflammation resolved, but persistently elevated in postoperative infection in dogs, following orthopaedic surgery.

In the present study, between the groups, group II had higher values of AKP, when compared to those of group I. Similar to the results of the present study, Singh et al. (1976) [26] Delmas, (1995) [5] , Komnenou et al. (2005) [14] , Rani et al. (2012) [25] and Duffy et al. (2018) [7] also observed a consistent elevation in serum alkaline phosphatase activity throughout the fracture healing period, which was associated with enhanced osteoblastic activity and active bone regeneration. Nyman et al. (1991) [22] suggested that serum alkaline phosphatase could serve as a useful biochemical indicator for identifying delayed or complicated bone union. However, the values of CPK and LDH were found elevated in both the groups although the values were comparatively higher in group II, that remain elevated even at 60 th POD. Lactate dehydrogenase is released into circulation during cellular injury and tissue necrosis, and increased serum levels may occur in conditions involving infection, bone damage and malignancy (Farhana and Lappin, 2023) [8] . The elevated levels of lactate dehydrogenase (LDH), creatine phosphokinase (CPK) and alkaline phosphatase (ALP) which were associated with extensive bone destruction, tissue necrosis, and inflammatory processes (Brozmanová and Skrovina, 1977). Since LDH originated from multiple tissues, its diagnostic specificity for bone disease was considered limited, although it could serve as an adjunct indicator of cellular damage in orthopaedic conditions (Kaneko et al., 2008) [12] . Creatine kinase was a cytosolic enzyme released into the bloodstream following muscle injury or cellular damage and elevated serum CK activity is commonly associated with muscle trauma, inflammation, and tissue necrosis (Farhana and Lappin, 2023) [8] . These results are quite similar to those of Phaneendra et al. (2018) [24] and Malin and Witkowska-Piłaszewicz (2022) [16] , who also observed elevated levels of CRP, CPK and LDH during the early postoperative period that decreased progressively as fracture healing advanced in dogs following repair of compound tibial fractures.

Conclusion

Overall, both groups demonstrated progressive radiographic healing characterized by a transition from inappropriate or absent healing (scores 2-3) during early intervals to appropriate progression and near-complete healing (scores 0-1) during later postoperative periods.

In the present study, all the animals that were presented after having been treated with surgical procedures had considerable anaemia, leucocytosis and elevated ESR, when compared to those that were treated with external co-optaion. Elevated preoperative values of CRP were observed in both the groups, which gradually decreased significantly at different time intervals in both the groups. In the present study, between the groups, group II had higher values of AKP, when compared to those of group I.

However, the values of CPK and LDH were found elevated in both the groups although the values were comparatively higher in group II, that remain elevated even at 60 th POD.

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