Effect of tibial tuberosity advancement on the contact mechanics and the alignment of the patellofemoral and femorotibial joints

Comparison of patellofemoral contact pressure after semi-cylindrical recession trochleoplasty and trochlear block recession in feline cadavers

Introduction

The purpose of this study was to compare the changes in the patellofemoral joint (PFJ) contact mechanisms of the normal state, trochlear hypoplasia model and after performing trochleoplasty on the hypoplasia model in feline cadavers.

Methods

Twenty normal pelvic limbs were acquired from the 10 feline cadavers. First, the PFJ contact mechanisms were measured in normal state, then trochlear hypoplasia models were created using customized trochlear ridge cutting guides. After measuring PFJ contact mechanisms in the trochlear hypoplasia models, they were divided into two groups and performed semi-cylindrical recession trochleoplasty (SCRT) and trochlear block recession (TBR) were performed, respectively. After that, the PFJ contact mechanisms were measured and the values of the 4 groups (normal state, trochlear hypoplasia, SCRT, TBR) were compared.

Results

The trochlear hypoplasia group showed increased contact pressure and decreased contact areas compared to the normal state group. In the groups that underwent tracheoplasty (SCRT and TBR), PFJ contact mechanisms were recovered similarly to that of the normal state group. The PFJ of the SCRP group was measured similar to that of the normal group than that of the TBR group.

Discussion

Tracheoplasty can be useful in restoring PFJ contact mechanisms and SCRT can be considered as a good alternative to the conventional methods of trochleoplasty.

Patellofemoral contact mechanics after transposition of tibial tuberosity in dogs

Background

Tibial tuberosity transposition (TTT) causes caudalization of the patellar ligament insertion in canine medial patellar luxation, which can lead to increases in patellofemoral contact pressure.

Objectives

The purpose of this study is to confirm the effect of patellofemoral contact mechanics after craniolateral and caudolateral transposition of tibial tuberosity in normal canine hindlimbs.

Methods

Craniolateral and caudolateral transposition of tibial tuberosity was performed in 5 specimens, respectively. The pressure was measured in the specimen before TTT, and then in the same specimen after TTT. In this process, data was obtained in 10 specimens. The measurement results were output as visualization data through the manufacturer's software and numerical data through spreadsheet. Based on these 2 data and the anatomical structure of the patellofemoral joint (PFJ) surface, whole measurement area was analysed by dividing into medial, lateral and central area.

Results

In craniolateralization of tibial tuberosity, total, medial, central contact pressure was decreased and lateral contact pressure was not statistically changed lateral contact pressure than normal PFJ. In caudolateralization of tibial tuberosity, total, lateral contact pressure was increased and medial contact pressure was not statistically changed than normal PFJ. Although not statistically significant changed, central contact pressure in caudolateralization of tibial tuberosity was increased in all 5 specimens.

Conclusions

These results imply that traditional TTT, prone to caudal shift of patellar tendon, can increase retropatellar pressure may lead to various complications and diseases of the stifle joint.

Effects of quadriceps angle on patellofemoral contact pressure

BACKGROUND

An inappropriate Q angle may affect the biomechanics of the canine patellofemoral joint.

OBJECTIVES

The purpose of this study was to evaluate the effects of changes in quadriceps angle (Q angle) on patellofemoral joint pressure distribution in dogs.

METHODS

Eight stifles were positioned at 45, 60, 75, 90, 105, and 120° of flexion in vitro, and 30% body weight was applied through the quadriceps. Patellofemoral contact pressure distribution was mapped and quantified using pressure-sensitive film. For the pressure area, mean pressure, peak pressure, medial peak pressure, and lateral peak pressure, differences between groups according to conditions for changing the Q angle were statistically compared.

RESULTS

Increases of 10° of the Q angle result in increases in the pressure area (P = 0.04), mean pressure (P = 0.003), peak pressure, and medial peak pressure (P ≤ 0.01). Increasing the Q angle by 20° increases the pressure area (P = 0.021), mean pressure (P ≤ 0.001), peak pressure (P ≤ 0.01), and medial peak pressure (P ≤ 0.01) significantly, and shows higher mean (P ≤ 0.001) and peak pressures than increasing by 10°. Decreasing the Q angle increases the mean pressure (P = 0.013), peak pressure, and lateral peak pressure (P ≤ 0.001).

CONCLUSIONS

Both increases and decreases in the Q angle were associated with increased peak patellofemoral pressure, which could contribute to the overloading of the cartilage. Therefore, the abnormal Q angle should be corrected to the physiologically normal value during patellar luxation repair and overcorrection should be avoided.

A novel method for quantifying femoral neck anteversion: A case study in extinct and extant sloths

Extinct sloths represent a wide range of morphological, locomotor, and body size variation. Researchers have examined femoral neck angle in two dimensions to hypothesize locomotor behaviors in this group; however, this measure does not account for femoral neck anteversion. Here, we present a new method for quantifying femoral neck anteversion angle, in addition to femoral neck angle, to capture the 3D position of the femoral head/neck. Femora of extant (n = 21; Bradypus and Choloepus) and extinct (n = 49; Acratocnus, Megalocnus, Neocnus, and Parocnus) sloths were surface scanned and their surface models used to calculate three angles of femoral neck anteversion and femoral neck angle. Femoral neck anteversion was calculated as the angle between the femoral neck axis and the geometric axis of the femoral condyles (GA), the 35% cross section axis, and a trochanter axis. Femoral neck angle was calculated as the angle between the femoral neck and shaft axes. Genera were compared using ANOVAs with post hoc multiple comparisons for each angle. Femoral neck angle and femoral neck anteversion relative to the cross section were also analyzed. Significant differences among genera exist for all angles, (p < .001) but not all angles separate all genera. Femoral neck and anteversion angles typically yield different results, demonstrating the utility of analyzing both angles. The GA and cross section angles are highly correlated in sloths, with the exception of comparisons among Megalocnus, Parocnus, and Neocnus, suggesting morphological variation in the distal femur. While this method was applied to sloths, it has broad applicability to mammalian groups.

Comparison of tension band wiring and other tibial tuberosity advancement techniques for cranial cruciate ligament repair: an experimental study

BACKGROUND

Cranial cruciate ligament (CCL) rupture is one of the most common causes of limb lameness in dogs. Surgical techniques based on tibial osteotomies such as tibial plateau leveling osteotomy and tibial tuberosity advancement are used to eliminate dynamic thrust. Tibial tuberosity advancement (TTA) uses an osteotomy fixated by cage, plates, forks and screws to change the relationship of the patellar tendon and tibial plateau angle. Tension band wiring technique is one of the most common surgical methods used to treat a tension fracture and remains the gold standard for the treatment of tibial tuberosity fractures. In this study, we compared experimentally the biomechanical effect of application of tension band wiring compared to other techniques for the fixation of the TTA osteotomy. The techniques compared to are standard commercially available systems for TTA fixation.

RESULTS

Tension band wiring (TBW) presented the higher resistance to failure compared to all the other surgical procedures, with the highest values found in the TBW group with 1.47 ± 0.07 N and the lowest in the TTA cage (0.82 ± 0.08) and TTA-2 (0.85 ± 0.06) groups with statistically significant differences in all cases (P < 0.001). TTA rapid and TTA plate groups exhibited a similar strength, and same happened between TTA-2 and TTA cage groups. All the other comparisons by pair were significantly different with P < 0.001.

CONCLUSIONS

Results suggest that fixating the osteotomy with tension band wiring increases the strength of the fixation and decrease the risk of implant failure. Further clinical studies are needed to demonstrate in vivo reliability and to test different variables such as size and weight of dogs. These results could have important clinical implications in the treatment of CCL ruptures.

Relationship between the stage of osteoarthritis before and six months after tibial tuberosity advancement procedure in dogs

The present retrospective study evaluated the progression of osteoarthritis in stifle joints based on the radiographic grade of osteoarthritis (OA) scored in dogs with cranial cruciate ligament rupture. The aim of the study was to search for a correlation between the stage of radiographic osteoarthritis prior to surgery and the osteoarthritis progression occurring after the tibial tuberosity advancement (TTA) procedure. It was hypothesized that the procedure carried out in dogs in the early stages of OA could reduce the OA changes. A total of 190 X-ray images obtained from the medical records of 38 dogs were evaluated. The radiographic signs of osteoarthritis of 38 stifle joints were scored from 0 to 3 in 10 specific anatomic locations. The radiographs were divided into 4 groups based on the global scores: A) no-OA, B) mild-OA, C) moderate-OA, D) severe-OA; they were assessed prior to surgery, and 1, 2, 3 and 6 months post-operatively (T0, T1, T2, T3 and T6). There were no differences in osteoarthritis progression in Groups A and C at any time. Osteoarthritis changes from T0 to T6 were statistically significant in Group B. The OA changes in the anatomic locations were investigated. The most common anatomic sites for OA changes were the patella apex, the proximal and distal trochlear ridges, and the caudal aspect of the tibial plateau assessed before surgery. After surgery, the score increased in the first three locations in 10, 9 and 11 joints, respectively; instead, the progression of osteoarthritis in the caudal aspect of the tibial plateau occurred in 23 out of 38 stifle joints. The results indicated that the TTA procedure could be effective in slowing down the OA progression when carried out in the absence of or in the early stages of disease. Therefore, an early intervention may be suggested in clinical practice to obtain minimal or no progression 6 months postoperatively.

Effective Mechanical Advantage Allometry of Felid Elbow and Knee Extensors

Larger terrestrial mammals have generally been found to use more extended limb postures, a mechanism which maintains muscular requirements at larger sizes by improving the effective mechanical advantage (EMA) of limb musculature. Felids, however, have been documented to maintain joint angles across body sizes. If felid morphology scales isometrically, it would mean larger felids have relatively weaker muscles, compromising locomotor activities. Here, we examine the allometric relationships between the EMA of the elbow and knee extensors and body mass, finding that the EMA of the triceps brachii and quadriceps muscles scale with positive allometry. When species-specific joint angles were used rather than felid-average joint angles, EMA scales to body mass with more positive allometry. When the scaling of the muscle and ground reaction force (GRF) lever arms were investigated individually the allometric signal was lost; however, the muscle lever arms generally have allometric slope coefficients that are consistent with positive allometry, while the GRF lever arms demonstrate negative allometric slope coefficients. This suggests there are subtle alterations to limb morphology allowing different felid species to achieve an increased EMA via distinctive mechanisms. The quadriceps EMA was found to scale with sufficient positive allometry to compensate for increases in size without alteration in muscular anatomy; however, this is not the case for the triceps brachii EMA. Anat Rec, 2018. © 2018 Wiley Periodicals, Inc. Anat Rec, 302:775-784, 2019. © 2018 Wiley Periodicals, Inc.

Ex vivo preliminary investigation of radiographic quantitative assessment of cranial tibial displacement at varying degrees of canine stifle flexion with or without an intact cranial cruciate ligament

Background

The presence of cranial tibial subluxation can aid in the detection of joint instability as a result of CrCL injury. Detection of cranial tibial subluxation has been described using the tibial compression test (TCT) and cranial drawer test (CDT); however, diagnosis of CrCL insufficiency by assessing cranial subluxation motion of the tibia is subjective and difficult to quantify accurately. The aim of this study was to investigate a measurement technique to assess the degree of cranial tibial displacement relative to the femoral condyles on mediolateral projection stifle radiographs at varying degrees of stifle flexion (90°, 110°, and 135°) in CrCL intact, partially, and completely transected conditions. Radiographic measurements included: CrCL length and intercondylar distance (ICD), defined as the distance between the tibial mechanical axis (TMA) and the femoral condylar axis (FCA). The influence of CrCL status, stifle flexion angle, and measurement type on measured distance was evaluated. The relationship between CrCL length and ICD measurement was also assessed.

Results

Complete transection of the CrCL resulted in significant cranial tibial displacement. Stifle flexion angle affected ICD, but not CrCL length. Normalized measured CrCL length and ICD were significantly different; however, no differences existed between the change in distance detected by CrCL length and ICD measurements as CrCL transection status changed. Correlation coefficients detected a significant positive correlation between measured CrCL and ICD.

Conclusion

The ICD measurement technique was able to quantify tibial displacement at various stifle flexion angles in the intact and completely transected CrCL conditions. The ICD measurement was more affected by stifle flexion angle than was the CrCL length.

Electronic supplementary material

The online version of this article (10.1186/s12917-018-1599-5) contains supplementary material, which is available to authorized users.

In vivo fluoroscopic kinematography of cranio-caudal stifle stability after tibial tuberosity advancement (TTA): a retrospective case series of 10 stifles

It was the aim of the study to determine retrospectively cranio-caudal stifle instability following TTA (tibial tuberosity advancement) using fluoroscopic kinematography. Ten stifles (eight dogs, mean body weight 27.3 kg) with complete rupture of the cranial cruciate ligament and a mean follow-up of 12.8 weeks (5.4 - 28.4 weeks) after TTA underwent latero-lateral, uniplanar fluoroscopic kinematography while walking on a treadmill. Immediately before TTA, each stifle was explored arthroscopically and in the case of a longitudinal or bucket-handle tear of the caudal horn of the medial meniscus the unstable axial portion was resected. The high-speed fluoroscopic video sequences obtained were inspected visually for femoro-tibial translation (cranial drawer). The influence of postoperative patellar tendong angle (PTA), cage size and meniscal surgery on stifle stability was analyzed using logistic regression analysis. In three stifles, resection of unstable meniscal tissue was necessary. Fluoroscopically, nine out of ten stifles showed cranio-caudal instability. Three stifles were potentially overcorrected (post PTA < 90°), seven potentially undercorrected (post PTA > 90°). None of the three parameters analyzed had a significant influence on postoperative in vivo stability (p=0.0988). In conclusion, it appears that inadequate cranialization of the tibia tuberosity might be an expected result of the TTA procedure, as well as persistent cranio-caudal instability during walking. However, instability cannot solely be attributed to insufficient cranialization because three out of nine unstable stifles were sufficiently or even overcorrected (PTA ≤ 90°). Further in vivo studies are needed to resolve these conflicting findings.

Patellofemoral kinematics in dogs with cranial cruciate ligament insufficiency: an in-vivo fluoroscopic analysis during walking

Background

Complete rupture of the cranial cruciate ligament (CrCL) in dogs causes profound disturbance to stifle joint biomechanics. The objective of this study was to characterize the effects of cranial cruciate ligament (CrCL) insufficiency on patellofemoral (PF) kinematics in dogs during walking. Ten client-owned dogs (20-40 kg) with natural unilateral complete CrCL rupture were included. Dogs underwent computed tomographic scans to create digital bone-models of the patella and femur. Lateral projection fluoroscopy of the stifles was performed during treadmill walking. Sagittal plane PF kinematics were calculated throughout the gait cycle by overlaying digital bone models on fluoroscopic images using a previously described 2D-3D registration technique. For acquisition of kinematics in the contralateral (control) stifle, fluoroscopy was repeated 6-months after stabilizing surgery of the affected side. Results were compared between the pre-operative CrCL-deficient and 6-month post-operative control stifles.

Results

Craniocaudal PF translation was similar between CrCL-deficient and control stifles throughout the gait cycle. The patella was more distal and positioned in greater flexion throughout the gait cycle in CrCL-deficient stifles when compared to the control stifle at equivalent time points. There was no significant difference in PF poses between CrCL-deficient and control stifles at equivalent femorotibial flexion angles; however, common femorotibial flexion angles were only found over a small range during the swing phase of gait.

Conclusions

CrCL insufficiency altered PF kinematics during walking, where the changes were predominately attributable to the femorotibial joint being held in more flexion. Abnormal PF kinematics may play a role in the development of osteoarthritis that is commonly observed in the PF joint CrCL-deficient stifles.

Evaluation and application of the TTA-rapid method in dogs with cranial cruciate ligament rupture

The objective of this study intended the application of the current technique of modified tibial tuberosity advancement (TTA)-rapid method in dogs with cranial cruciate ligament rupture (CrCL) and reports on the clinical outcome and complications. The study material consisted of 17 male dogs of different breeds between the ages of 2-8 years, average weight of 32 kg with a diagnosed unilateral CCL rupture. Hudson Visual Analog Scale (HVAS)-Walking Test Rating, Canine Brief Pain Inventory (CPBI)-Pain Rating) were examined, and rupture of the CCL was diagnosed based on direct radiographic examination. The pre-operative evaluation of the implant to be used in TTA-Rapid technique was determined by measuring radiographic images of the CCL in dogs. Post-operative evaluation in the 1st, 2nd, and at 3 month was performed by radiographic examination, gait and pain tests. Major complications were recorded in 17.6% of the cases. Fourteen (82.4%) dogs had a good to excellent outcome 3 months after surgery. Lameness and pain assessment were performed up to 15 days prior to the operation and 1, 2, and 3 months after the TTA-Rapid technique procedure.

It can be concluded that TTA-Rapid technique procedure is a fast, easy to learn and non-invasive treatment of CrCL ruptures in dogs.

Normal patellofemoral kinematic patterns during daily activities in dogs

Background

Patellar abnormalities are a common cause of pain and lameness in dogs; however, in vivo the relative motion between the femur and patella in dogs is not well described. The objective of this study was to define normal in vivo sagittal plane patellofemoral kinematics in three axes of motion using non-invasive methods. We hypothesized patellofemoral alignment in the sagittal plane would tightly correlate with the femorotibial flexion angle. Six healthy dogs without orthopedic disease underwent computed tomography (CT) of their hind limbs to create 3-D models of the patella and femur. Normal stifle joint motion was captured via flat-panel imaging while each dog performed a series of routine activities, including sitting, walking, and trotting. The 3-D models of the patella and femur were digitally superimposed over the radiographic images with shape-matching software and the precise movement of the patella relative to the femur was calculated.

Results

As the femorotibial joint flexed, the patellofemoral joint also flexed and the patella moved caudally and distally within the femoral trochlea during each activity. Patellar flexion and distal translation during walk and sit were linearly coupled with the femorotibial flexion angle. Offset was evident while trotting, where patella poses were significantly different between early and late swing phase (p ≤ 0.003). Patellar flexion ranged from 51 to 6° while trotting. The largest flexion angle (92°) occurred during sit. The patella traversed the entire proximodistal length of the femoral trochlea during these daily activities.

Conclusions

Using single-plane flat-panel imaging, we demonstrated normal in vivo patellofemoral kinematics is tightly coupled with femorotibial kinematics; however, trot kinematic patterns did not follow the path defined by walking and stand-to-sit motions. Our normal data can be used in future studies to help define patellofemoral joint kinematics in dogs with stifle abnormalities.