Is There a Disadvantage to Early Physical Therapy After Multiligament Surgery for Knee Dislocation? A Pilot Randomized Clinical Trial

BACKGROUND

Multiligament knee injuries, though rare, can be profoundly disabling. Surgeons disagree about when to initiate rehabilitation after surgical reconstruction due to the conflicting priorities of postoperative stability and motion.

QUESTIONS/PURPOSES

(1) Does early or late initiation of physical therapy after multiligament knee surgery result in fewer postoperative manipulations? (2) Does early versus late physical therapy compromise stability postoperatively? (3) Does early initiation of physical therapy result in improved patient-reported outcomes, as measured by the Multi-ligament Quality of Life (ML-QOL) score?

METHODS

Between 2011 and 2016, 36 adults undergoing multiligament repair or reconstruction were prospectively enrolled in a randomized controlled trial and randomized 1:1 to either early rehabilitation or late rehabilitation after surgery. Eligibility included those with an injury to the posterior cruciate ligament (PCL) and at least one other ligament, as well as the ability to participate in early rehabilitation. Patients who were obtunded or unable to adhere to the protocols for other reasons were excluded. Early rehabilitation consisted of initiating a standardized physical therapy protocol on postoperative day 1 involving removal of the extension splint for quadriceps activation and ROM exercises. Late rehabilitation consisted of full-time immobilization in an extension splint for 3 weeks. Following this 3-week period, both groups engaged in the same standardized physical therapy protocol. All surgical reconstructions were performed at a single center by one of two fellowship-trained sports orthopaedic surgeons, and all involved allograft Achilles tendon PCL reconstruction. When possible, hamstring autograft was used for ACL and medial collateral ligament reconstructions, whereas lateral collateral ligament and posterolateral reconstruction was performed primarily with allograft. The primary outcome was the number of patients undergoing manipulation during the first 6 months. Additional outcomes added after trial registration were patient-reported quality of life scores (ML-QOL) at 1 year and an objective assessment of laxity through a physical examination and stress radiographs at 1 year. One patient from each group was not assessed for laxity or ROM at 1 year, and one patient from each group did not complete the ML-QOL questionnaires. No patient crossover was observed.

RESULTS

With the numbers available, there was no difference in the use of knee manipulation during the first 6 months between the rehabilitation groups: 1 of 18 patients in the early group and 4 of 18 patients in the late group (p = 0.34). Similarly, there were no differences in knee ROM, stability, or patient-reported quality of life (ML-QOL) between the groups at 1 year.

CONCLUSION

With the numbers available in this study, we were unable to demonstrate a difference between early and late knee rehabilitation with regard to knee stiffness, laxity, or patient-reported quality of life outcomes. The results of this small, randomized pilot study suggest a potential role for early rehabilitation after multiligament reconstruction for knee dislocation, which should be further explored in larger multi-institutional studies.

LEVEL OF EVIDENCE

Level II, therapeutic study.

Dislocation of modern design rotating hinge total knee arthroplasty : case series and narrative review

Knee dislocation is an infrequent complication after rotating hinge total knee arthroplasty (RHTKA). The aim of the present study was to describe our experience with dislocating RHTKA in a consecutive prospective large series, its occurrence rate, causative mechanisms and to perform a review of available literature. In total, six dislocations were observed in 303 RHTKA procedures (NexGen RHK, ZimmerBiomet, Warsaw, Indiana, US) at a mean of 10 (range, 2 - 24) months after surgery. This results in a 2% dislocation rate, which is lower than the 3.1% cumulative rate reported earlier in literature. Men and women were distributed equally, with a mean age of 56 years old. The indication for RHTKA among the six dislocations was revision in 4 cases and primary arthroplasty for the other 2 cases. Analysis revealed that the main mechanism of hinge dislocation was forced knee flexion with concomitant extensor mechanism insufficiency (4/6 cases). The second cause was unscrewing of the locking pin (2/6 cases). This is probably caused by the screw home mechanism that results in a counterclockwise torque -and therefore a loosening- effect on locking bolts, specifically in right-sided RHTKA. Obesity probably predisposes to hinge dislocation since 83% of patients in this series were obese (BMI, range 34 to 52). The findings of this study suggest that dislocation of RHTKA is a rare complication that could happen to obsese patients without an adequate extensor mechanism. Level of evidence : IV.

The Biomechanics of Multiligament Knee Injuries: From Trauma to Treatment

The multiple ligament injured knee is a complex biomechanical environment. When primary stabilizers fail, secondary stabilizers have an increased role. In addition, loss of primary restraints puts undue stress on the remaining intact structures of the knee. Treatment of these injuries requires accurate diagnosis of all injured structures, and careful consideration of repairs and reconstructions that restore the synergistic stability of all ligaments in the knee.

Epidemiology and outcomes of traumatic knee dislocations: Isolated vs multi-trauma injuries

BACKGROUND AND PURPOSE

Traumatic dislocation of the knee (TKD) is a rare injury, accounting for approximately 0.02% of orthopaedic injuries. They are a challenging entity for orthopaedic surgeons to manage, and can have devastating consequences. The aim of this study was to describe the epidemiology of traumatic knee dislocations (TKD'S) and contrast the incidence of neurovascular injury between isolated and multi-trauma dislocations as well as key patient reported outcomes achieved between these groups.

MATERIAL AND METHODS

Patients who had a traumatic disruption of the tibiofemoral articulation between March 1 2007 and February 31, 2015 were identified from the Victorian Orthopaedic Trauma Outcomes Registry (VOTOR). Data was cross-checked with medical records and radiological reports to confirm true multi-ligamentous dislocation. VOTOR collects information pertaining to orthopaedic injuries, treatment, complications and outcomes from four adult hospitals in Victoria, Australia, including the major trauma centers. Patient-reported outcomes are collected by VOTOR at 12 months post-injury including the EQ-5D-3L (EQ-5D) and Glasgow Extended Outcome Scores (GOS-E) and return to work status. Patient reported functional and quality of life outcomes at 12 months after injury were analysed.

RESULTS

A cohort of 88 patients were identified that fit the inclusion criteria for the study, and at 12 months post-injury there was data available for 80 patients (90.9%). There were 38 (42.9%) patients who experienced an isolated traumatic knee dislocation and 52 (57.1%) who experienced a traumatic knee dislocation in association with another injury. Of the 88 patients identified as eligible for the study, two had bilateral knee dislocations, hence there were 90 multi-ligamentous knee injuries. Those who were injured at a higher velocity were more likely to have additional injuries. Dislocations that occurred at a lower velocity were shown to have better overall outcomes, as did dislocations that occurred in isolation.

CONCLUSIONS

Traumatic knee dislocations that occur in isolation typically result in better outcomes than those that occur with associated injuries. TKD's are a rare but severe injury that requires further research in order for functional outcomes to be optimized.

Posterior tibial tendon transfer improves function for foot drop after knee dislocation

BACKGROUND

Knee dislocation may be associated with an injury to the common peroneal nerve with a subsequent foot drop. Previous studies have demonstrated good functional results after posterior tibial tendon transfer in patients with foot drop. No studies, to our knowledge, have focused exclusively on knee dislocation as the cause of common peroneal nerve injury leading to foot drop.

QUESTIONS/PURPOSES

We determined the percentage of patients developing common peroneal nerve paresis after knee dislocation, the symptom improvement rate in these patients, and patient-reported outcomes (American Orthopaedic Foot and Ankle Society [AOFAS] ankle-hindfoot score), ankle dorsiflexion strength, and ROM in patients with no symptom improvement treated with posterior tibial tendon transfer.

METHODS

Two hundred forty-seven patients with knee dislocation, defined as an injury to both the ACL and PCL with an additional injury to the lateral and/or medial ligaments (Schenck Classification II to IV), were registered in a single institution's database between 1996 and 2011. The database was queried for the frequency of documented injuries to the common peroneal nerve and, among those, the frequency of spontaneous resolution after this injury. Patients demonstrating no active dorsiflexion 12 months after injury generally were offered posterior tibial tendon transfer. Postoperatively, patients were evaluated for AOFAS score, ankle dorsiflexion strength, and ROM.

RESULTS

Forty-three patients (17%) had a common peroneal nerve paresis at admission. At 1-year followup, 15 of 43 patients (35%) had experienced symptom improvement. One patient experienced spontaneous improvement later than 1 year after injury. One patient was lost to followup. A below-knee amputation was performed in one patient due to the initial trauma. Seven patients were satisfied with their function using a brace or had medical contraindications to surgical treatment, while four patients refused the proposed operation with a tendon transfer, leaving 14 patients treated with posterior tibial tendon transfer. In the 12 patients available for evaluation, mean AOFAS score was 91 of 100. Mean (± SD) dorsiflexion strength was 118 (± 55) Nm on the operated side and 284 (± 94) Nm on the unaffected side (p < 0.001). Mean ROM was 67° (± 15°) on the operated side and 93° (± 14°) on the unaffected side (p < 0.001).

CONCLUSIONS

Based on these findings, we recommend posterior tibial tendon transfer for treatment of foot drop that persists at least 1 year after knee dislocation.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Early reduction for congenital dislocation of the knee within twenty-four hours of birth

BACKGROUND

Congenital dislocation of the knee (CDK) is a very rare condition that comprises a spectrum of deformities from subluxation to complete dislocation. The incidence of CDK is estimated at 1 per 100,000 live births, which is 1% of the incidence of developmental dysplasia of the hip (DDH). Moreover, 40-100% of patients with CDK have additional musculoskeletal anomalies, the most common being DDH and clubfoot. In general, the diagnosis is established immediately after birth according to the position of the knee recurvatum. Treatment with conservative methods at an early stage is most likely to yield successful results. We report here successful treatment of a series of CDK patients with early reduction.

METHODS

From July 1990 to June 2007, 19 patients with CDK (affecting 25 knees) were treated with early reduction. Of these, 6 knees had dislocation, and 19 had subluxation. Since 1990, treatment has been guided by a protocol that considers patient age and the severity of the condition. In patients examined within 24 hours of birth, early, direct reduction under gentle, persistent manual traction was attempted. Birth history and perinatal course were obtained from medical records. Associated musculoskeletal anomalies were observed and treated after reduction of the knee joint. A Pavlik harness was used for at least 4 months in the concomitant treatment of DDH and CDK. Knee function was graded as excellent, good, fair, or poor. Radiographs were used to assess DDH during follow-up.

RESULTS

After an average follow-up duration of 4.3 years, 18 patients showed an excellent or good outcome. One patient, whose knee could not be reduced, had severe multiple anomalies and died 16 days after birth. Fifteen of the nineteen patients had associated musculoskeletal anomalies, including DDH and foot deformity. Two cases of residual hip dysplasia after Pavlik harnessapplication required an acetabular osteotomy.

CONCLUSIONS

For CDK patients, early and direct closed reduction within 24 hours of birth affords outcomes graded as either excellent or good.

Kinematic patellar tracking from MR images for knee pain analysis

Kinematic approaches using MR images have been regarded of more accuracy in knee pain (AKP) detection than stationary approaches. However, the challenge in segmenting femur, patellar and tibia due to the intensity non-uniformity caused by magnetic propagation degradation in MR images, and the strong adhesion of the soft tissue around the knee organs, has restricted the use of kinematic approaches. This paper proposes a combinatorial based kinematic patellar tracking (CKPT) for AKP detection. The CKPT uses a hybrid approach for extracting knee organs, where an edge-constrained wavelet enhancement followed by moment preserving segmentation is employed for conquering the soft tissue adhesion for extracting the femur and tibia from axial MR images, and a sliding window based moment preserving for resolving the segmentation difficulty associated with intensity non-uniformity in sagittal MR images. The location constraints are then applied for extracting landmark points from femur and patellar, and three inclination angles reflecting patellar position and orientation, during leg movement, are calculated as the measurement of patellar dislocation. The experiment shows that the hybrid approach can accurately extract femur, patellar and tibia. It also demonstrates the prominent of the calculated inclination angles in detecting AKP.

Evaluation of patello-femoral alignment using MRI

In evaluating patello-femoral alignment, it is not enough to assess the conformity of the joint two-dimensionally, the direction of the extensor mechanism must be examined three-dimensionally. Using magnetic resonance imaging (MRI), we adopted an ideal extensor mechanism plane intersecting the patellar facet of the femur centrally and perpendicularly. We evaluated the alignment according to the extent to which the patella and/or the tibial tuberosity deviated from the plane. The results suggested that our method is useful for indicating proximal and distal realignment. Furthermore, two-dimensional finite element analysis in the patello-femoral joint showed that peak stress was significantly higher in the dislocation group than in the no-dislocation group. This indicates that osteoarthritic change in the future is a risk in the dislocation group.

In vivo contact areas of the knee in patients with patellar subluxation

OBJECTIVE

Ex vivo studies have suggested that cartilage contact areas and pressure are of high clinical relevance in the etiology of osteoarthritis in patients with patellar subluxation. The aims of this study were therefore to validate in vivo measurements of contact areas with 3D open magnetic resonance imaging (MRI), and to study knee joint contact areas in patients with patellar subluxation at different angles of knee flexion in comparison with healthy subjects.

METHODS

3D-MRI data sets of 12 healthy volunteers and eight patients with patellar subluxation were acquired using a standard clinical (1.5 T) and an open (0.2 T) MRI scanner. We compared femoro-patellar and femoro-tibial contact areas obtained with two different sequences from open MRI [dual-echo-steady-state (DESS) and fast-low-angle-shot (FLASH) sequences] with those derived from standard clinical 1.5 T MRI. We then analyzed differences in joint contact areas between healthy subjects and patients with patellar subluxation at 0 degree, 30 degrees, and 90 degrees of knee flexion using open MRI.

RESULTS

The correlation of the size of contact areas from open MRI with standard clinical MRI data ranged from r = 0.52 to 0.92. Open-MRI DESS displayed a smaller overestimation of joint contact areas (+21% in the femoro-patellar, +12% in the medial femoro-tibial, and +19% in the lateral femoro-tibial compartment) than FLASH (+40%, +37%, +30%, respectively). The femoro-patellar contact areas in patients were significantly reduced in comparison with healthy subjects (-47% at 0 degree, -56% at 30 degrees, and -42% at 90 degrees of flexion; all p < 0.01), whereas no significant difference was observed in femoro-tibial contact areas.

CONCLUSIONS

Open MRI allows one to quantify joint contact areas of the knee with reasonable accuracy, if an adequate pulse sequence is applied. The technique permits one to clearly identify differences between patients with patellar subluxation and healthy subjects at different flexion angles, demonstrating a significant reduction and lateralization of contact areas in patients. In the future, application of this in vivo technique is of particular interest for monitoring the efficacy of different types of surgical and conservative treatment options for patellar subluxation.

Palsy of the common peroneal nerve after traumatic dislocation of the knee

Injury to the common peroneal nerve was present in 14 of 55 patients (25%) with dislocation of the knee. All underwent ligament reconstruction. The most common presenting direction of the dislocation was anterior or anteromedial with associated disruption of both cruciate ligaments and the posterolateral structures of the knee. Palsy of the common peroneal nerve was present in 14 of 34 (41%) of these patients. Complete rupture of the nerve was seen in four patients and a lesion in continuity in ten. Three patients with lesions in continuity, but with less than 7 cm of the nerve involved, had complete recovery within six to 18 months. In the remaining seven with more extensive lesions, two regained no motor function, and one had only MRC grade-2 function. Four patients regained some weak dorsiflexion or eversion (MRC grade 3 or 4). Some sensory recovery occurred in all seven of these patients, but was incomplete. In summary, complete recovery occurred in three (21%) and partial recovery of useful motor function in four (29%). In the other seven (50%) no useful motor or sensory function returned.

Knee dislocations: management of the multiligament-injured knee

Knee dislocations can occur in low-energy athletic injuries and in high-velocity motor vehicle trauma. These injuries require urgent recognition for evaluation for neurovascular injury. Advances in surgical reconstruction of multiligament-injured knees have led to more predictable return of function. This article reviews the diagnosis, initial treatment, and definitive management of multiligament-injured knees.

Irreducible posterolateral knee dislocation resulting from a low-energy trauma

A small amount of knee dislocations is included in the irreducible knee dislocations group. In such instance, medial femoral condyle is buttonholed through the gap formed by medial retinacular and capsular structures and this prevents reduction. In this study, we present two cases in which there were irreducible posterolateral knee dislocations resulting from a low-energy trauma. In both cases, dimple sign produced by the invagination of the medial retinacular structures and capsule and ecchymosis medially were noted. Soft tissue invaginated between the trochlea and intercondylar notch was extracted by open reduction.

Valgus knee injuries: evaluation and documentation using a simple technique of stress radiography

Clinical assessment of post traumatic ligament laxity is subjective. Stress radiographs provide an objective and permanent record of the laxity. We describe a simple method of stress radiography to help evaluate and to document valgus knee injuries. In this study we have correlated the X-ray findings with those at arthroscopy. No specialised equipment is required and radiation exposure to the patient and the surgeon is minimal. With the patient under general anaesthesia the injured and the normal knee are firmly bound together. A valgus stress is applied to both the knees simultaneously and a radiograph is taken. The opening of the medial joint space is measured as in the figure 1, i.e. the perpendicular distance between the tangent drawn to the subchondral bone of the femoral condyles, and the most medial point of the tibial plateau. The opening of the medial joint space provides a direct measure of valgus laxity. The ratio of the medial joint opening to the normal knee is calculated. A ratio of two or more is indicative of an associated anterior or posterior cruciate ligament rupture in addition to medial collateral ligament injury.