Client-assessed long-term outcome in dogs with surgical site infection following tibial plateau levelling osteotomy

Outcome in 12 Dogs with Chronic Radiographic Cranial Tibial Subluxation after Tibial Plateau Leveling Osteotomy (2019-2021)

Objective

The objective of this study was to examine outcomes in dogs with cruciate ligament rupture (CR) that had chronic radiographic cranial tibial subluxation at the time of osteotomy healing after tibial plateau leveling osteotomy (TPLO). Study Design. Retrospective case analysis of 12 dogs with prospective follow-up. Four of the 12 dogs were prospectively studied 12-24 months after surgery to assess long-term radiographic and clinical outcomes.

Results

Three of the 4 dogs showed improvement in radiographic cranial tibial subluxation at long-term follow-up. In the other dog, minimally improved cranial tibial subluxation was associated with severe lameness. At long-term follow-up, gait analysis in 3 dogs with improved subluxation showed the symmetry of weight-bearing within 10% for peak vertical force, and no clinically lameness. Preoperative tibial plateau angle (TPA) and radiographic osteoarthritis in dogs with prospective follow-up and all dogs treated with TPLO surgery in the study period were not significantly different.

Conclusion

Dogs with chronic radiographic cranial tibial subluxation are acceptable candidates for TPLO. Radiographic improvement in stifle reduction may take more than 10 weeks. The dog with long-term persistent subluxation also had a higher TPA over time, suggestive of ineffective surgical correction with TPLO and treatment failure.

Clinical relevance of positive intraoperative bacterial culture in tibial plateau leveling osteotomy in dogs: a retrospective study

BACKGROUND

Tibial plateau leveling osteotomy (TPLO) belongs to the most frequently used surgical method for the treatment of cranial cruciate ligament rupture in dogs. Surgical site infection (SSI) is one of the possible postoperative complications. The aim of this study was to evaluate the diagnostic value of intraoperative bacterial culture as a tool for the detection of intraoperative bacterial contamination progressing to infection development in canine TPLO. Electronic patient records from dogs who underwent TPLO between January 2018 to December 2020 were retrospectively reviewed. Intraoperative bacterial culture results, used antimicrobial drugs and presence of SSI were recorded.

RESULTS

Ninety-eight dogs were included in the study. SSI rate was 10.2%. All dogs who developed SSI (n = 10) had negative intraoperative bacterial cultures. None of the dogs with positive intraoperative bacterial culture (n = 6) developed SSI. The most cultured bacteria causing SSI was Staphylococcus pseudintermedius (n = 4).

CONCLUSIONS

Intraoperative bacterial culture in dogs undergoing TPLO is not suitable as a predictor of surgical site infection.

Evaluation of a client questionnaire at diagnosing surgical site infections in an active surveillance system

OBJECTIVE

To report sensitivity, specificity, predictive values and accuracy of a client questionnaire at diagnosing surgical site infections (SSIs) and describe the impact of active surveillance on SSI detection.

STUDY DESIGN

Prospective, cohort study.

ANIMALS

Dogs and cats undergoing soft tissue or orthopedic surgery over a 12-month period at a referral hospital.

METHODS

Clients were emailed a questionnaire 30 days postoperatively, or 90 days where an implant was used. Three algorithms were developed to diagnose SSIs using one or both of two criteria: (1) presence of any wound healing problems; (2) wound dehiscence or antibiotic prescription, and either purulent discharge or two or more clinical signs (redness, pain, heat, swelling, discharge). Algorithmic diagnoses were compared to gold standard diagnoses made by veterinarians.

RESULTS

Of 754 surgical procedures, 309 responses were completed with 173 corresponding gold standard diagnoses. The most accurate algorithm determined "SSI" or "No SSI" from 90.2% of responses with 95.5% (92.4-98.6) accuracy, 82.6% (77-88.3) sensitivity, 97.7% (95.5-100) specificity, 86.4% (81.2-91.5) positive predictive value, and 97% (94.5-99.6) negative predictive value. "No SSI" was diagnosed in responses not meeting criterion 1, and "SSI" in responses meeting criteria 1 and 2. "Inconclusive" responses, comprising 9.8% of responses, met criterion 1 but not 2. Overall SSI rate was 62/754 (8.2%) and 12/62 (19.4%) SSIs were detected by active surveillance only.

CONCLUSION

Use of this client questionnaire accurately diagnosed SSIs; active surveillance increased SSI detection.

CLINICAL SIGNIFICANCE

Surveillance of SSIs should be active and can be simplified by using a client questionnaire and algorithmic diagnoses, allowing automated distribution, data collection and analysis.

Minimal clinically-important differences for the 'Liverpool Osteoarthritis in Dogs' (LOAD) and the 'Canine Orthopedic Index' (COI) client-reported outcomes measures

Client-reported outcomes measures (CROMs) have been previously validated for the evaluation of canine osteoarthritis. A published systematic review indicated that the 'Liverpool Osteoarthritis in Dogs' (LOAD) and the 'Canine Orthopedic Index' (COI) can be recommended for use in dogs with osteoarthritis; these CROMs have also been used in the context of measuring surgical outcomes of dogs with orthopaedic conditions. However, the minimal clinically-important differences (MCIDs) for these CROMs have not been investigated. Such estimates would be useful for investigators and regulators so that these CROMs can be used in clinical trials. Data from the RCVS Knowledge Canine Cruciate Registry were extracted, and baseline and 6 week follow-up data on dogs that had received surgery for cranial cruciate ligament rupture were used to make estimates of MCIDs using distribution-based and anchor-based methods. Data from 125 dogs were categorised based on the anchor question and LOAD and COI scores analysed accordingly. The four anchor-based methods provided a range of MCIDs for each CROM (1 to 8.8 for LOAD and 3.5 to 17.6 for COI). In the two different distribution-based methods, the MCIDs for LOAD ranged from 1.5 (effect size) to 2.4 (standard error of measurement) and the effect size method yielded a result of 2.2 for COI. The results showed that the value of the MCIDs depended on the method that was applied. Receiver operator characteristic curves provided areas under the curve (AUCs) greater than 0.7, which indicated that the cut-off point was acceptable; LOAD had the greater AUC at 0.867. In summary, the authors currently recommend a MCID of '4' for LOAD and '14' for COI although further work in other clinical contexts (such as osteoarthritis associated with chronic pain) is required to add confidence to these estimates. For the first time, we have provided estimates for MCIDs for these two CROMs which will facilitate sample size estimates in future clinical studies that use these CROMs as outcomes measures.

Surgical treatment of cranial cruciate ligament disease in dogs using Tibial Plateau Leveling Osteotomy or Tibial Tuberosity Advancement-A systematic review with a meta-analytic approach

Tibial Plateau Leveling Osteotomy (TPLO) or Tibial Tuberosity Advancement (TTA) are commonly used surgical techniques for correction of cranial cruciate ligament (CCL) rupture in dogs. This systematic review aims to investigate whether one technique is superior to the other. Seventy-two studies on surgical management of CCL rupture have been identified and evaluated in regard of subjective and objective gait analysis criteria, development of osteoarthritis (OA), thigh circumference measurements, goniometry, joint stability, pain and complication rates. Almost half (47.2 %) of the studies were considered of low quality of evidence, leading to high heterogeneity in quality among studies; this posed a major limitation for an evidence-based systematic review of both surgical techniques. Out of 72 studies, there were only eleven blinded randomized clinical trials, of which five were rated with a low overall risk of bias. However, both techniques were considered to be successful management options. Subjective and objective gait analysis revealed no lameness at long-term evaluation for the majority of the patients. However, it appeared that TTA lead to better OA scores up to 6 months postoperatively, while TPLO had a lower rate of surgical site infections. In summary, no method can be clearly preferred, as most of the study evaluated were subpar. Studies with a high level of evidence are therefore urgently needed for such a common surgical procedure.

Risk factors for severe postoperative complications in dogs with cranial cruciate ligament disease - A survival analysis

OBJECTIVE

To analyze the effect of surgical technique and other risk factors on severe postoperative complications in dogs with cranial cruciate ligament disease (CCLD).

MATERIALS AND METHODS

A cohort study of 255 dogs (287 stifles) surgically treated for CCLD at two veterinary university hospitals (2011-2016) was performed. The electronic medical records were reviewed and dog owners and referring veterinarians contacted for additional information. The complications were classified as minor, major and catastrophic, where major and catastrophic were considered severe. A multivariable Cox proportional hazards model was applied to assess risk factors for severe postoperative complications.

RESULTS

Three surgical techniques were used; lateral fabellotibial suture (LFS, 141 stifles), tibial plateau leveling osteotomy (TPLO, 77 stifles) and tibial tuberosity advancement (TTA, 69 stifles). The most common severe postoperative complications were surgical site infections or complications related to the surgical implant. Severe postoperative complications occurred in 31 % of the stifles treated with TPLO, 22 % of the stifles treated with LFS and 25 % of the stifles treated with TTA. The multivariable Cox proportional hazards model identified surgical technique (p = 0.0258) as a risk factor for severe postoperative complications; TPLO had a significantly lower hazard than LFS (hazard ratio (HR) = 0.37, p = 0.007) when controlling for body weight and age, which also were identified as risk factors (HR = 1.05, p < 0.001 and HR = 0.91, p = 0.047, respectively).

CONCLUSION AND CLINICAL RELEVANCE

Although TPLO procedures had the highest occurrence of severe postoperative complications, the hazard was lower than for LFS after adjusting for body weight and age. This implies that it is important to consider potential effect-modifiers when comparing postoperative complications after CCLD surgery.

Timing of and risk factors for deep surgical site infection requiring implant removal following canine tibial plateau leveling osteotomy

OBJECTIVE

To identify demographic risk factors for deep surgical site infection (SSI) requiring tibial plateau leveling osteotomy (TPLO) implant removal and time to implant removal.

ANIMALS

Four hundred and thirty-three dogs that underwent a TPLO (144 that developed a deep SSI and required implant removal, 289 that did not).

STUDY DESIGN

Retrospective case-control study.

METHODS

Records of dogs undergoing implant removal due to a deep SSI after TPLO between 2006 and 2018 at two referral centers were reviewed. These records were frequency-matched by date to dogs undergoing TPLO that did not require implant removal. Multivariable analyses tested associations between demographics and implant removal as well as timing of implant removal.

RESULTS

Deep SSI and implant removal occurred in 144 of 4813 (3.0%; 95% CI: 2.5, 3.5) dogs treated with TPLO. Implant removal was performed at a median of 279 days (range 49-2394 days) postoperatively. Male dogs (OR 1.8; 95% CI: 1.2, 2.7) and German Shepherd dogs (GSDs) (OR 7.4; 95% CI: 2.6, 20.5) were associated with plate removal. Earlier TPLO plate removal was associated with GSDs only (HR 2.4; 95% CI: 1.4, 4.1).

CONCLUSION

Implant removal due to SSI after TPLO was uncommon, although male dogs and GSDs seemed predisposed to this complication.

SIGNIFICANCE

These demographic risk factors can be used to educate owners regarding perioperative management.

Efficacy of postoperative antibiotic use after tibial plateau leveling osteotomy in dogs: A systematic review

OBJECTIVE

A systematic review of published data to determine whether postoperative antibiotic use after tibial plateau leveling osteotomy (TPLO) decreases infection rates.

STUDY DESIGN

Systematic review.

METHODS

A broad bibliographic search was performed in three online databases through March 2020 for publications on postoperative antibiotic use after TPLO in dogs. Search terms included dog, canine, TPLO, tibial plateau leveling osteotomy, infection, antibiotic, and antimicrobial. Articles that met inclusion criteria were evaluated for level of evidence (LoE) by a modified Oxford Level of Evidence (mOLE) and GRADE (Grading of Recommendations, Assessment, Development and Evaluation) classification and evaluation.

RESULTS

Thirteen studies met the inclusion criteria. Effect of antibiotic use was the primary question in four studies. Among those, 50% (2/4) were assigned a mOLE of 1b and a GRADE of moderate, while the other 50% (2/4) were assigned a mOLE of 4b or 4c with a GRADE of low. The two studies with the highest LoE did not provide evidence of the benefit of antibiotic usage. Results of only one study provided evidence to support the use of postoperative antibiotics. The remaining nine studies provided evaluation of antibiotic use secondarily and were all assigned a low LoE. Among these, 78% (7/9) provided evidence to support the use of postoperative antibiotics.

CONCLUSION

We found little evidence to support the use of postoperative antibiotics to reduce the risk of surgical site infections in dogs after TPLO. The answer to this clinical question is complicated by the lack of prospective studies and inconsistent treatment protocols in the evaluated studies.

CLINICAL SIGNIFICANCE

The clinical impact of postoperative antibiotic administration on infection rates after TPLO is uncertain.

Investigation of Variables Associated with Surgical Site Infection following the Management of Canine Cranial Cruciate Ligament Rupture with a Lateral Fabellotibial Suture

OBJECTIVE

 This study investigated variables associated with surgical site infection (SSI) in dogs with cranial cruciate ligament rupture managed with stifle joint examination and lateral fabellotibial suture stabilization.

STUDY DESIGN

 A retrospective study of dogs that had stifle arthroscopy, stifle arthrotomy, or a combination of both, followed by lateral fabellotibial suture stabilization for cranial cruciate ligament rupture. All cases had a minimum follow-up of 90 days. Lameness grades were recorded preoperatively, and at 6-week and final follow-up.

RESULTS

 One hundred fifty procedures in 130 dogs met the inclusion criteria. Overall, SSI rate was 17.3% and removal of the lateral fabellotibial suture was performed in 53% of SSI. Multivariable analysis showed significant association between SSI and bodyweight (p = 0.013), and induction using propofol (p = 0.029). Multilevel ordinal logistic regression analysis showed a greater proportion of dogs had a higher lameness grade at 6-week (p = 0.021) and final follow-up (p = 0.002) assessments in the infected compared with non-infected dogs.

CONCLUSION

 Our study demonstrated a higher SSI incidence than previously reported in dogs undergoing a lateral fabellotibial suture for cranial cruciate ligament rupture. Bodyweight and induction with propofol were identified as significant risk factors for postoperative SSI. Owners could be advised of an increased SSI risk in larger dogs and consideration should be given to selection of induction agent. Dogs that develop an SSI have a worse lameness grade at 6-week and final follow-up.

Contributing factors to surgical site infection after tibial plateau leveling osteotomy: A follow-up retrospective study

OBJECTIVE

To identify factors associated with surgical site infection (SSI) after tibial plateau leveling osteotomy (TPLO).

STUDY DESIGN

Retrospective case series.

ANIMALS

Dogs (n = 541) that underwent TPLO (n = 659).

METHODS

Medical records of dogs that underwent TPLO from 2011-2018 were reviewed. Data collected included perioperative and postoperative antimicrobial administration, stifle inspection, duration of surgery and anesthesia, comorbidities, and development of SSI including timing, microbiological investigation, and implant removal. Referring veterinarians were contacted for all dogs without a recorded return visit. Risk factors for SSI were assessed by using a multivariable logistic regression model built by using a stepwise approach.

RESULTS

Surgical site infection was documented in 71 of 659 (11%) TPLO, with methicillin-resistant Staphylococcus pseudintermedius accounting for 20 of 71 (28%) infections. Protective factors against SSI included administration of postoperative antimicrobials (odds ratio [OR] 0.263; 95% CI = 0.157, 0.442) and timing of preoperative antimicrobial administration. Preoperative antimicrobial timing was protective against SSI when it was administered more than 60 minutes before the first incision compared with administration within 30 minutes (OR 0.275; 95% CI = 0.112, 0.676) or within 60 minutes (OR 0.419; 95% CI = 0.189, 0.929) of the first incision.

CONCLUSION

Early administration of perioperative antimicrobials and postoperative antimicrobial administration were protective against SSI after TPLO.

CLINICAL SIGNIFICANCE

Antimicrobials can influence the risk of SSI after TPLO. Perioperative and postoperative antimicrobial administration timing should be considered to reduce SSI.

Risk of infection after double locking plate and screw fixation of tibial plateau leveling osteotomies in dogs weighing greater than 50 kilograms

OBJECTIVE

To compare surgical site infection (SSI) rates after double locking plate and screw fixation (DLP), standard locking plate and screw fixation (LP), and conventional nonlocking plate and screw fixation (NLP) in dogs weighing >50 kg undergoing tibial plateau leveling osteotomy (TPLO).

STUDY DESIGN

Retrospective study (January 2003-October 2017).

ANIMALS

Two hundred seventy-five dogs weighing >50 kg with cranial cruciate ligament disease treated with TPLO.

METHODS

Medical records of dogs weighing >50 kg that underwent TPLO by DLP, LP, and NLP with a minimum follow-up period of 12 months were included. Data collected included signalment, details of any concurrent surgical procedure, type of implant used, use of postoperative antibiotic therapy, occurrence of perioperative complications, and presence of postoperative infection. The probability, risk difference, and relative risk of SSI were estimated for each fixation with a marginal model.

RESULTS

Nonlocking plate and screw fixation was used in 114 (41.5%) dogs, LP was used in 128 (46.5%) dogs, and DLP was used in 33 (12%) dogs. Surgical site infection was diagnosed in 48 of 275 (17.5%) dogs. Postoperative antibiotic therapy was used in 74 (64.9%) dogs, 62 (48.4%) dogs, and 32 (97.0%) dogs in the NLP, LP, and DLP groups, respectively. Dogs with NLP, LP, and DLP had postoperative infection rates of 24.5%, 13.3%, and 9.1%, respectively. There were no risk differences for the three groups (Holm-adjusted P > .05).

CONCLUSION

No difference in infection rates was detected between DLP, LP, or NLP for TPLO in these dogs weighing >50 kg.

CLINICAL SIGNIFICANCE

Fixation of TPLO with DLP in dogs weighing >50 kg does not seem to increase the risk of SSI compared with LP and NLP.

Usefulness of C-reactive protein and serum amyloid A in early detection of postoperative infectious complications to tibial plateau leveling osteotomy in dogs

Background

Cranial cruciate ligament rupture is a prevalent injury in dogs, and tibial plateau leveling osteotomy (TPLO) is one of the preferred surgical techniques. Surgical site infection is a possible complication following TPLO and measurement of serum acute phase proteins is suggested to be a way to early recognize and distinguish postoperative infectious complications from normal postoperative inflammatory conditions. In this study we investigate the changes in concentrations of the systemic inflammatory markers C-reactive protein (CRP) and serum amyloid A (SAA) following tibial plateau leveling osteotomy (TPLO) in dogs and evaluate if deviations from the changes expectedly induced by the surgical procedure are useful in early detection of post-surgical infections. Dogs with cranial cruciate ligament injuries treated by TPLO at the Region Animal Hospital of Helsingborg during 2012 were included. Dogs with concurrent diseases, other orthopedic problems, or noninfectious post-surgical complications were excluded. Serial measurements of CRP and SAA concentrations were made. Changes in concentrations were visualized graphically and the discriminative capacity to detect infectious post-surgical complications was tested at different time points.

Results

A characteristic pattern of changes in concentrations of CRP and SAA were observed following TPLO with a significant increase 24 h post-surgery in all dogs and baseline-concentrations re-established at day 12. In dogs that developed post-surgical infections, a deviation in form of significantly higher concentrations of CRP and SAA were observed at day 6, compared to un-complicated cases. High-discriminative clinical decision limits of CRP (43.9 mg/L) and SAA (63.8 mg/L) could be established for differentiation of dogs with and without clinical signs of infectious complications at day 6 post-operatively, applicable to reliably rule out presence of infectious complications due to very high sensitivity (no false negatives).

Conclusions

The CRP and SAA levels in dogs with clinical signs of post-surgical infectious complication deviated from the typical levels expected at day 6 after surgery, and clinical decision limits to reliably rule out presence of infectious complications was suggested.

Initial adhesion of methicillin-sensitive and methicillin-resistant Staphylococcus aureus strains to untreated and electropolished surgical steel drill bits

Electropolishing of stainless steel has been thoroughly investigated as a prophylactic measure to prevent bacterial colonization of orthopaedic implants and infection. Initial bacterial adhesion onto surgical drill bits as a possible factor for orthopaedic surgical site infections has not yet been documented. The present study investigated the influence of electropolishing on initial staphylococcal adhesion onto AISI 440A stainless steel drill bits. Specifically, one methicillin-susceptible standard laboratory Staphylococcus aureus type strain (DSM 20231^T), one methicillin-resistant S. aureus reference strain (DSM 46320) and one methicillin-resistant clinical isolate from an infected orthopaedic implant were used. After standard sterilization, drill bits were immersed in the respective bacterial suspension; bacteria adherent to surface were harvested by vortexing the drill bits in phosphate-buffered saline and viable counts of bacteria transferred from the suspension were made (transferred to log10 for further analysis). Electropolishing significantly reduced adhesion of the clinical S. aureus strain and the S. aureus DSM 20231^T. However, electropolishing significantly increased adhesion of the S. aureus DSM 46320. These results show that electropolishing significantly influences initial adhesion of S. aureus strains to surgical drill bits and that the nature of this influence depends on the S. aureus strain examined. For a general recommendation of electropolishing drill bits and guidelines for their handling during surgery, further studies with more strains isolated from infected wounds are suggested.