• All dogs received perioperative Cephazolin 22 mg/kg.
• All dogs received traditional TTA procedure (KYON or Medicatech Vet).
• Meniscal release or meniscectomy was performed based on preference.
• No bone grafts were placed on osteotomy site.
• All patients received postoperative coaptation.

Minor complications – not included

Medial meniscal tear

40.5% had medial meniscal injury and were treated with partial meniscectomy

59.4% had normal meniscus. 72.4% of these dogs had meniscal release. 0.5% of these dogs developed postliminary meniscal injury.

27.6% of dogs with normal meniscus did not receive meniscal release. 10.2% developed postliminary meniscal injury.

Postoperative patellar luxation

1.2% developed patellar luxation postoperatively.

Surgical site infection

6.9% of dogs developed superficial surgical site infection All were managed successfully with conservative treatment. 1.1% developed deep SSI necessitating surgical intervention.

Implant failure and fractures

1% of dogs had implant failure requiring revision surgery.

0.7% (11 dogs) developed fracture; 3/11 tibial diaphyseal fractures and 8/11 tibial tuberosity fracture.

PICO – three (0.18%) tibial diaphyseal fractures were reported.

• This study is retrospective and may be affected by bias in case selection and suitability for TTA.
• Factors that could have affected surgical outcome were not assessed, such as limb conformation or body condition score.
• Minor complications were not assessed.
• Being retrospective in nature, this study confuses the term incidence with prevalence.
• Did not correlate the use of perioperative antibiotics and the development of surgical site infection.
• There was no power calculation.

68 tTTAs were performed with forked plates.

75 tTTAs were performed with screw plates.

Minor complications in 12 dogs include forked plate displacement (6), tibial tuberosity fracture (4), screw failure (2) and cage displacement (1).

Forked plates had greater complications compared to screw plates.

Four stifle joints had tibial tuberosity fractures.

PICO – One stifle joint had tibial diaphyseal fractures (0.007%).

• The radiographic complications were evaluated by only one radiologist.
• The radiographic scoring system is subjective and may be prone to inter-operator variability.
• There is no control population (unilateral TTA) used for comparison and testing of the null hypothesis.
• Comparison was based on results of other studies.
• The outcomes of patients with major and minor complications were not reported.
• Non-radiographic complications were not reported.
• Statistical significance (P value) for comparing complications between forked and screw plates was not reported.

• All dogs received plated TTA by the same surgeon.
• Dogs with meniscal pathology were partially or completely resected. Dogs with intact meniscus were left in situ.
• Consecutive records were plotted retrospectively using cumulation summation technique (CUSUM) to measure cumulative success for clinical audit and competence of a single surgeon over time.

• Cumulative success rates of a single general practitioner surgeon.
• Major and minor complication rates.

Minor complications in 14/167 (8%)

• Superficial wound infection (8/13)
• Minor dehiscence (1/13)
• Seroma (4/13)
• Acute lameness responding to conservative treatment 3/13)
• Septic arthritis not requiring surgery 1/13

Major complications in 15/167 (9%)

• Septic arthritis requiring surgery 3/15
• Tibial tuberosity fracture 3/13
• Medial patellar luxation 1/15
• Late meniscal injury (6/15)
• Major dehiscence (1/15)
• Severe patellar desmitis (1/15)

Overall success rate is 91% over 167 procedures.

22 procedures were required before the published veterinary surgeon became acceptably competent to perform tTTA and have complications within published ranges.

PICO – 0 dogs had tibial diaphyseal fractures.

• This paper only measured success as the absence of complication rates, and not the clinical outcome.

All dogs received forked plate TTA

Meniscus:

• 12/36 Boxers and 94/271 non-Boxers had cranial cruciate ligament remnant debrided.
• 8/36 Boxers and 91/271 non-Boxers had medial meniscal injury treated with partial meniscectomy.
• 2/36 Boxers and 15/271 non-Boxers had complete medial meniscectomy.
• 1/36 Boxers and 3/271 non-Boxers had medial meniscal release.
• 15/34 Boxer and 111/250 non-Boxer stifle joints received bone graft.

Antibiotics:

• 11/30 Boxers and 123/264 non-Boxers received amoxicillin-clavulanic acid perioperatively.
• 19/30 Boxers and 141/264 non-Boxers received Cefuroxime perioperatively.
• 24/36 Boxers and 152/271 non-Boxers received antibiotics postoperatively.

• 14/36 (38.9%) Boxers and 37/271 (13.6%) non-Boxers had major complications (P < 0.001).
• 6/36 (16.7%) Boxers and 6/271 (2.21%) non-Boxers had minor complications (P = 0.003).
• 4/36 (11.1%) Boxers and 22/271 (8.1%) non-Boxers had late meniscal injury (P = 0.52).
• 7/36 (19.4%) Boxers and 11/271 (4.1%) non-Boxers had postoperative infections.
• Boxers compared to non-Boxers had an odds ratio of 5.78 of developing complication.
• 2/36 (5.6%) Boxers had tibial tuberosity fractures compared to 1/271 (0.4%) non-Boxers (P = 0.03).
• PICO – 0 cases had tibial diaphyseal fractures.

• Retrospective design predisposes the study population towards bias.
• Complication rates were determined based on medical records of a referral hospital – this may have been under- or over-estimated as it does not take into consideration complication rates detected by a referring veterinarian.
• This study includes complications by residents as well as specialists, which may influence the incidence due to the learning curve of residents.
• Small number of Boxer dogs compared to control population (36 vs. 271).
• No randomisation or blinding, which can lead to bias.

All dogs received plated TTA system – manufacturer undefined.

All dogs received commercial synthetic or cancellous bone graft on osteotomy site.

Some dogs received external coaptation (number undefined).

All dogs were re-evaluated at:

• 10 weeks postoperatively to evaluate skin sutures
• 4 and 8 weeks for radiographs.

Major and minor complication rates of bTTA compared to uTTA at 4 and 8 weeks postoperatively.

Major complications defined as complications requiring further surgery.

Minor complications defined as any other complications.

bTTA 11/88 (12.5%) vs. uTTA 2/86 (2.3%)

Minor complication rates (significantly different)

bTTA 23/88 (26.1%) vs. uTTA 21/86 (24.4%)

Overall complication rate (no significant difference)

bTTA 31/88(35.2%) vs. uTTA 21/86 (24.4%)

Fracture

bTTA – 2/88 tibial diaphyseal fracture and 9/99 tibial tuberosity fracture

uTTA – 1/88 tibial tuberosity fracture

PICO – 2/88 (2.3%) tibial diaphyseal fracture in bTTA and 0/88 in uTTA

• Retrospective design.
• tTTA procedure was modified over time so there could have been more complications in earlier cases.
• Postoperative care was not standardised.
• Did not compare staged bTTA vs single-stage bTTA.
• Relative risks were not reported.

• All dogs underwent arthrotomy or arthroscopy.
• No dogs received meniscal release.
• Partial meniscectomy performed in cases of meniscal injury.
• All dogs received plated Securos Surgical TTA XGEN system.
• All dogs received autologous cancellous bone graft into osteotomy space.
• All dogs received exercise restriction for 6 weeks.

• SSI 2/24 – resolved with antibiotics.
• Fracture of tibial tuberosity 1/24.
• Recurrent lameness 6/24 dogs – responded to conservative management.

PICO – 0 dogs had tibial diaphyseal fracture.

• Very small sample size.
• Utilised thigh circumference (TC) and range of motion (ROM) as a measure of limb use, as opposed to peak vertical forces.
• Postoperative rehabilitation was performed on some dogs and not others, which may influence TC and ROM.
• Clinical outcomes were subjectively measured using lameness score.
• Follow up radiographic signs of osteoarthritis were measured subjectively by one certified radiologist.

54 stifle joints received Tibial Plateau Leveling Osteotomy (TPLO)

TTA group

Overall complication – 33%

Major complication rate 18/91 (19.8%)

• 14/91 surgical site infection
• 4/91 tibial tuberosity fracture
• 1/91 stifle joint receiving TTA resulted in diaphyseal fracture
• 4/91 required implant removal
• One case concurrent tibial tuberosity fracture and SSI

Minor complication rate – 13/91 (13.2%)

• Seroma – 7/91
• Minimally displaced tibial tuberosity fracture 3/91
• Remainder – patellar desmitis, incidental implant breakage and incisional dehiscence

PICO – 1/91 (1.1%) cases had tibial diaphyseal fracture

TPLO group

Major complications – 15/54 (27.8%)

• 14/54 (25.9%) surgical site infection
• 8/54 (14.8%) required implant removal

Minor complication – 12/54 (22.2%)

• 7/54 seroma
• 2/54 incisional irritation
• 2/54 fibular fracture

• Surgeries were performed either by a specialist or resident. However, a comparison between the two groups was not analysed.
• The power of the study was not indicated.
• Authors did not declare how many dogs were censored and excluded for not meeting the inclusion criteria.
• Lack of randomisation.
• Reliance on medical record accuracy.
• Declared conflict of interest from one of the authors, who receives royalties for Securos Surgical XGEN TTA system.

• All dogs received TTAR surgery.
• No dogs received meniscal release.
• All but four dogs received nanocrystalline hydroxyapatite paste on osteotomy gap.

• Outcome was considered clinically satisfactory in 99% of 135 dogs 3 months postoperatively and 86% of 108 dogs in owner questionnaire.
• 44/152 (29%) of stifle joints had medial meniscal injury requiring meniscectomy
• 9/108 (8%) developed late meniscal injury
• 3/152 (1.97%) stifle joints developed SSI treated adequately with antibiotics
• 2/152 (1.3%) developed fracture of the tibial tuberosity
• Tibial osteotomy gap healed at a mean and median of 7.94 and 7 weeks.

PICO – 1/152 (0.66%) developed tibial diaphyseal fracture treated by internal fixation.

• Medium term follow-up was conducted using owner-assessed questionnaire.
• Outcome was based on subjective clinical exam.
• Number of cage size and number of breeds were reported but not correlated against each other.
• No control group for comparison.

• All dogs received amoxicillin clavulanic acid 8.75 mg subcutaneously preoperatively.
• All dogs received TTAR surgery.
• All dogs received meniscal release.
• All dogs received hydroxylapatite bone paste onto osteotomy gap.
• All dogs had external coaptation for 2–3 days postoperatively.
• All dogs received postoperative antibiotics for 5 days.

• 42% of dogs had medial meniscal injury.
• All owners were satisfied with outcome of surgery.
• Subjective assessment at 3 months postoperatively showed 28 dogs (56%) had an excellent outcome, 20 dogs (40%) had a good outcome and two dogs (4%) had a moderate outcome (one clinical healing and one complete healing of the osteotomy).
• 15/50 (30%) of dogs had undefined minor complication (undefined).
• 2/50 (4%) dogs developed tibial tuberosity fracture; only one required surgical revision.

PICO – 0% of dogs developed tibial diaphyseal fracture

• Postliminary meniscal injury not reported.
• Unclear if SSI did not develop or was unreported.
• Small sample size.
• Short follow-up times (3 months).
• Not tested against a control group.
• Not all dogs received surgery with the aid of a saw guide.
• Outcome was based on subjective clinical exam only.
• Conflict of interest that the developer of the technique is also the primary author.

• 40 small breed dogs (48 stifle joints) received TTAR surgery. 19/48 stifle joints received TTAR with Maquet hole, 29/48 had no Maquet hole.
• No dogs received meniscal release.
• No dogs received bone graft.
• All dogs were on exercise restriction for 6 weeks.

• Major complication rate 7/48 (14.6%)
• Infection – 1/48 (0.02%)
• Medial meniscal injury noted in 19/48 (40%)
• Late meniscal injury rate 2/48 (4.7%)
• 2/48 developed tibial tuberosity fracture requiring surgical stabilisation
• 1/19 (5.26%) stifle joints with Maquet hole resulted in tibial diaphyseal fracture
• 1/29 (3.45%) stifle joints without Maquet hole resulted in tibial diaphyseal fracture
• 2/48 (4.17%) stifle joints in total resulted in tibial diaphyseal fracture

PICO – 2/48 (4.17%) developed tibial diaphyseal fracture

• Small sample size.
• Outcome was measured by subjective client questionnaire that has not been validated.
• No control group or comparison with an alternative technique.
• Lack of objective outcome criteria.

• 17 stifle joints received TTAR surgery with Maquet hole
• All dogs received perioperative antibiotics amoxicillin clavulanic acid (8.75 mg/kg subcutaneously)
• All dogs received carprofen 4 mg/kg perioperative analgesia
• All dogs received 3 days postoperative meloxicam 1 mg/kg (Intramuscular) and 5 days amoxicillin clavulanic acid (undeclared dose).

• Minor complication rate was 25%.
• Major complication rate is 17.6% (4/17 dogs).
• Tibial crest fracture occurred in 2/17 fractures; only one required surgery.

PICO – 0/17 stifle joints receiving TTAR resulted in tibial diaphyseal fracture.

• Meniscal findings and injury rate not reported.
• Minor complications were not defined.
• The outcomes were measured subjectively using visual analogue scales. A clinician was used to assess outcome with blinding and control but the control was not defined.
• Competency of the surgeon was not defined (specialist vs. resident vs. general practitioner).
• This study has a very small sample size for assessment of complication rates.
• There is no control group to assess if there would be improvement with no treatment.

• Overall complication rate – 8/17 (47%)
• Minor complication rate – 3/17 (17.6%)
• Major complication rate – 5/17 (29.4%)
• Surgical site infection – 4/17 (23.5%)

PICO

• TTAR
• N = 6
• Major complication – 0/6
• Minor complication – 2/6

• Small sample size – 6 TTAR and 11 Orthofoam-Modified Maquet Procedure.
• Variation in surgeons managing complication – six boarded specialist vs. four RCVS Certificate qualified veterinary surgeons.
• Owner compliance to original procedure was not measured or accounted for.
• Incidence of these tibial diaphyseal fractures could not be determined.
• No comparison with fracture complications from traditional TTA methods.