Complications from Cranial Cruciate Ligament Surgery

Complications from Cranial Cruciate Ligament Surgery: Rehabilitation Considerations

Matthew W. Brunke, David Levine, David L. Dycus and Denis J. Marcellin‐Little

15.1 Introduction

The field of veterinary rehabilitation has expanded as veterinarians have realized the importance of optimizing oversight and postoperative care and managing patients with a variety of conditions without surgery [1]. Rehabilitation therapy uses a number of techniques such as manual therapy physical modalities, and therapeutic exercises. The overarching goal of rehabilitation is to return patients to the best possible level of function as pets or working dogs, while improving their quality of life.

Pathology of the cranial cruciate ligament (CCL) has received attention from a rehabilitation perspective both following surgical stabilization and as part of a conservative approach to CCL injuries [2]. The benefits of surgical stabilization for CCL ruptures have been widely investigated [3]. By comparison, the benefits of rehabilitation following CCL surgery have only been reported in a limited number of studies [4, 5]. Several therapeutic steps used in rehabilitation after CCL surgery have been shown to be beneficial, including cold compression therapy [6], neuromuscular electrical stimulation (NMES) [7], and extracorporeal shockwave therapy [8, 9].

A recent survey reported that 71% of the veterinarians who replied consistently recommended postoperative rehabilitation following CCL surgery [10]. Of those surveyed, 39% recommended rehabilitation for all cases postoperatively and 16% recommended that patients receive a consultation with a rehabilitation practitioner. Individuals were more likely to recommend rehabilitation therapy in geriatric, inactive, sporting and working dogs, and in cases with severe muscle atrophy or with decreased range of motion of the stifle or tarsus. The recommendations for rehabilitation therapy appeared to be based on what individuals were taught during veterinary school or during their residency training and, to a lesser extent, on published evidence or information learned at a conference. Most (92%) reported that guidelines for rehabilitation therapy in dogs after CCL surgery are helpful.

While individuals are generally familiar with rehabilitation following CCL surgery and often recommend rehabilitation, a need for specific guidelines remains. Also, several factors may deter individuals from recommending rehabilitation, such as its cost, the availability or distance to rehabilitation facilities, and the required time commitment [10]. In addition, some individuals may be under the impression that rehabilitation could increase likelihood of complications (Table 15.1), and therefore could hesitate to recommend rehabilitation.

One study evaluated the safety of a formal rehabilitation protocol following tibial plateau leveling osteotomy (TPLO) [2]. One treatment group underwent a formal rehabilitation plan and the other group underwent a traditional postoperative management protocol consisting of cage confinement and controlled leash walks. Perioperative complications and functional outcomes 8 weeks, 6 months, and 1 year after surgery were evaluated. The overall complication rate with both groups (26%) was consistent with complication rates reported in other studies. There was no difference in the complication rate in both groups, suggesting that formal rehabilitation does not increase the risk of complications. Further, at the 8‐week time point, dogs in the formal rehabilitation plan were 1.9 times more likely to have returned to full function while dogs in the traditional postoperative plan were 2.9 times more likely to have unacceptable function.

The fear of complications resulting from rehabilitation exists in human medicine, where a subset of orthopedic surgeons reportedly have concerns related to the fact that rehabilitation professionals do not always possess sufficient knowledge of tissue healing times and postsurgical limitations [11]. Veterinarians could have similar concerns. Interprofessional communication can ensure that all caregivers are well informed and in agreement with regard to activity levels. The preferred communication methods vary among clinicians [12].

While the literature suggests that formal rehabilitation after CCL surgery is safe and efficacious, rehabilitation can also be used to help identify complications or prevent the progression of minor complications to major complications. One of the key advantages of formal rehabilitation is the frequent face‐to‐face evaluation of the patient by the rehabilitation practitioner. In most situations, patients are undergoing rehabilitation therapy once or twice a week. This gives the practitioner the ability to observe patients often and learn characteristics of their gait, limb use, and functional abilities throughout the postoperative period. The rehabilitation practitioner can use objective and subjective measures to ensure appropriate recovery and that a complication is not present. For example, evaluation of gait, palpation of the surgical limb (to assess for the presence of patellar ligament desmitis, for example), measurement of joint angles (goniometry), and measurement of thigh circumference provide information that informs clinicians of the potential presence of a complication.

15.2 Gait Evaluation

The evaluation of gait is an important aspect of recovery. Most patients recover in predictable fashion after CCL surgery but the rate of increase in limb use varies based on signalment, chronicity, and type of surgical intervention. Patients undergoing extracapsular stabilization often are nonweight bearing for the first few days after surgery. They tend to remain nonweight bearing for a longer period of time and take longer to regain full limb usage than patients undergoing TPLO or other osteotomies. After 3–5 days, they often are toe‐touching and slowly progress to a weight‐bearing lameness by the second week after surgery. Patients undergoing osteotomy‐based procedures tend to be toe‐touching at a slow speed the morning following surgery. Three to 5 days later, they bear weight consistently at a walk but still display a moderate lameness during weight bearing. By the second week, their lameness is commonly mild.

It is important that the rehabilitation practitioner and the veterinarian have an appreciation for the recovery of gait following any surgical procedure. The appreciation of differences in recovery rate and the regular observation of patients facilitate early detection of complications. Any deviation from anticipated limb use and setbacks in limb use during recovery should raise suspicion of a potential complication and trigger patient reevaluation. In some situations, delays in recovery or limb use setbacks represent a minor complication that requires no further intervention, beyond rest. In other situations, delays in recovery may represent early signs of a major complication where an intervention is warranted.

Table 15.1 Complications after surgical stabilization of cranial cruciate ligament injury in dogs.

Surgical procedure Complications Potential causes
Extracapsular stabilization or Tightrope® procedure Cranial drawer sign Failure of fixation (line breakage, fabellar displacement)
Excessive internal rotation Failure of fixation
Lack of stifle extension Tibial tunnel is excessively distal

Excessive (caudal) articular or periarticular fibrosis
Lack of stifle flexion Excessive joint effusion

Quadriceps muscle changes

Excessive (cranial) articular or periarticular fibrosis

Suture line not isometric (Tightrope™procedure)
Limb disuse Lack of isometric suture placement

Failure of fixation


Meniscal tear
Tibial tuberosity advancement Cranial thrust Crest is not sufficiently advanced

Failure of fixation
Excessive internal rotation Preoperative torsional instability of the stifle
Limb disuse Infection

Failure of fixation

Meniscal tear
Tibial plateau leveling procedure Cranial thrust Tibial plateau is not sufficiently rotated

Failure of fixation (plateau rollback)
Excessive internal rotation Preoperative torsional instability of the stifle
Valgus or varus angulation Preexisting angular deformity of the tibia or femur

Failure of fixation

Plateau osteotomy or reduction is oblique
Limb disuse Infection

Failure of fixation, fibular fracture

Meniscal tear

Patellar tendonitis, patellar or tibial crest fracture

Several subjective scales and objective parameters can be used for gait evaluation. Various subjective numerical scales ranging from 1 to 4, 1 to 5 (Table 15.2), or 1 to 6 or a visual analog scale (VAS) can be used [13]. For both subjective numerical scales and VAS, the same examiner should evaluate the gait of the patient at each visit and document it in the medical record. The same scale should be used for all evaluations. Objective gait evaluation provides more precise information related to patient recovery and is more reliable than subjective gait evaluation, particularly when the lameness is mild. The agreement between numerical scales, VAS, and objective force plate analysis is low, suggesting that numeric scales and VAS are flawed for the assessment of lameness in dogs [14].

Table 15.2 Example of a 0–V numerical rating scale for subjective assessment of grading canine lameness.

Source: Adapted from Carr and Dycus [13].

Grade 0 Normal gait, no lameness
Grade I Weight shifting, mild lameness noted at the trot, sound at the walk
Grade II Mild weight‐bearing lameness at the walk as noted by an experienced observer
Grade III Weight‐bearing lameness at the walk
Grade IV Severe weight‐bearing to toe‐touching lameness at the walk
Grade V Nonweight‐bearing lameness

Kinematic gait analysis objectively describes gait by quantifying joint motion, limb segment velocity, acceleration, and deceleration, and angles of structures in space and time. Patients are often fitted with reflective markers and high‐speed cameras are used to capture motion. Kinetic gait analysis involves the use of a force plate to measure ground reaction forces, in particular the peak vertical force (pVF, the largest vertical forced resisted by each limb) and vertical impulse (VI, the product of force and time during each stride for each limb). Both kinematic and kinetic gait analysis are mostly used in research settings and are uncommonly used for clinical evaluation. However, smartphone applications with 2D analysis are becoming more available to calculate joint angles passively (Figure 15.1) and during gait [15].

Pressure‐sensing walkways and weight distribution platforms are emerging as objective tools for patient assessment (Figure 15.2). Pressure‐sensing walkways have been studied to determine normal and abnormal gaits in dogs of various dog breeds [1620]. Walkways use sensors to calculate velocity, stance time, swing time, stride length, step length, and the total pressure index (TPI). Pressure‐sensitive walkways along with kinematic and kinetic evaluations rely on dynamic weight distribution to detect abnormalities during the gait. More recently, weight distribution platforms have been used to evaluate gait abnormalities in a static manner, when dogs are standing in place. Patients alter their static weight distribution as a result of pain. Even less is known about the shifts in weight distribution that result from limb pain in standing dogs compared to walking or trotting dogs. Weight distribution platforms collect measurements that are as accurate and repeatable as static standing on a pressure‐sensitive walkway [21]. The sensitivity and specificity of weight distribution platforms for the detection of orthopedic lameness have been evaluated in clinical patients, making this method of objective evaluation an emerging consideration during postoperative recovery [22].

Snapshot of4 a goniometric measurement collected using a phone-based application. The baseline of the goniometer is oriented along the femoral shaft and the moving arm is oriented along the tibial shaft. The application indicates that the stifle joint has a 91° angle.

Figure 15.1 Screen capture of a goniometric measurement collected using a phone‐based application (Protractor,, Kewlsoft, London, UK). The baseline of the goniometer is oriented along the femoral shaft and the moving arm is oriented along the tibial shaft. The application indicates that the stifle joint has a 91° angle.

The use of objective measures of gait can be incorporated into the postoperative evaluations to confirm continued improvement. While little information is known regarding the range in gains in pressure‐sensitive walkway or weight distribution platforms after various CCL surgeries, rehabilitation clinicians who examine gait and limb use regularly are well prepared to detect a lack of progress in limb use or delayed progress during the recovery period. For dogs enrolled in a formal rehabilitation program, abnormal progress is often suggestive of the presence of a complication.

Photo depicts screen capture of a video of a dog walking on a pressure-sensitive walkway. The handler is walking the dog at a constant speed. The dog is controlled by a leash. There is no tension on the leash to avoid artifacts. Also, the dog is walking in a straight line and is looking forward.

Figure 15.2 Screen capture of a video of a dog walking on a pressure‐sensitive walkway. The handler is walking the dog at a constant speed. The dog is controlled by a leash. There is no tension on the leash to avoid artifacts. Also, the dog is walking in a straight line and is looking forward.

15.3 Surgical Limb Evaluation

Palpation of the surgical limb is also critical to the detection of potential complications. In the early postoperative period, particular attention is paid to the surgical incision to ensure appropriate healing with no evidence of excessive inflammation, infection, or seroma formation. Variations in surgical technique and intraoperative tissue trauma lead to differences in surgical wound inflammation. Any incision that appears inconsistent with common standards is reported to the group that performed the surgery. A conversation between the rehabilitation practitioner and the veterinarian who did the surgery optimizes subsequent management.

15.4 Range of Motion Evaluation

The rehabilitation clinician should evaluate the range of motion of the stifle joint, the presence of a pain response to flexion and extension, and the craniocaudal and torsional stability of the joint. For example, extracapsular stabilization of a CCL‐deficient stifle joint can fail, resulting in the reoccurrence of stifle instability, detected through a decrease in limb use and the presence of a cranial drawer sign. In contrast, a decrease in limb use in a patient after an osteotomy can result from a failure of plate fixation and tibial plateau rollback. For a patient recovering from an osteotomy, the presence of cranial drawer is expected during the recovery period.

Joint motion is critical to limb use. Therefore, monitoring the motion of the stifle joint throughout recovery provides valuation information. Rehabilitation clinicians should monitor joint motion quantitatively by measuring maximal motion using goniometry and qualitatively by evaluating the pain response to joint motion and the feel at the end of motion (the end feel). Goniometry has been validated in several dog breeds (Table 15.3

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Apr 3, 2022 | Posted by in EQUINE MEDICINE | Comments Off on Complications from Cranial Cruciate Ligament Surgery

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