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The authors describe a new procedure for replacement of both cruciate ligaments. They use a single anterior approach and a unique transplant, consisting of a long band including part of the patellar tendon, part of the patella and part of the quadriceps tendon. The technique is indicated in some cases of major instability of the knee.
On the basis of review of results of 60 kinematic condylar knee replacements in 49 patient and the literature the principles of surgical techniques in varus and valgus deformities of the knee and patellar subluxation have been presented. The authors substantiated their opinion of contraindication for patellar replacement. Tibial components (AJ, PCR, Total Condylar) have been discussed and data on frequency of their use provided. Instrumentation supplied does not guarantee the precision desired, the surgeons experience is indispensable.
Disorders of the patella are the most common cause of anterior knee pain. The etiologies of anterior knee pain are reviewed. A case report of an acute displaced patella fracture in a bipartite union is presented. Bipartite patellar development, incidence, radiographic findings, and clinical symptoms follow. Treatment of excision of displaced fragment provides an excellent result.
The effect of a newly developed patellar realignment brace was evaluated in 21 patellofemoral joints (19 patients) with patellar subluxation (13 joints with lateral subluxation and eight with medial subluxation) by using active-movement, loaded kinematic magnetic resonance (MR) imaging. Sixteen patellofemoral joints (76%) demonstrated a qualitative correction of or improvement in patellar subluxation (ie, centralization of the patella or a decrease in the displacement of the patella) after application of the brace. Four of the five "failures" occurred in patellofemoral joints that had patella alta and/or dysplastic bone anatomy. These results indicate that the patellar realignment brace was able to counteract patellar subluxation in the majority of patellofemoral joints studied, as shown by active-movement, loaded kinematic MR imaging. This brace appears to be useful for conservative treatment of patients with patellofemoral joint pain secondary to patellar malalignment and maltracking.
At least seven parameters have been described for the measurement of patellofemoral malalignment on CT scanning; three of which measure lateral patellar tilt, two lateral patellar shift and two femoral trochlear dysplasia. We studied 22 knees in 18 patients complaining of patellofemoral pain in order to investigate the reproducibility of these methods. CT scans of the patellofemoral joint were performed in each knee at 0 degrees and 20 degrees of flexion. The seven parameters were recorded from each scan by three independent observers in a blind study. The reproducibility was studied by means of the intraclass correlation coefficient (ICC). Parameters measuring lateral patellar tilt showed excellent reliability (ICC>75%). The measurements of lateral patellar shift and femoral trochlear dysplasia showed a fair or poor correlation (ICC<75%). We suggest that parameters for measuring lateral patellar tilt only should be used from CT scanning when planning treatment for patello-femoral malalignment.
We describe the radiographic measurement of the angle of tilt of the patella and relate it to malalignment of the extensor mechanism. The tilt angle is defined as the angle subtended by a line joining the medial and lateral edges of the patella and the horizontal. The radiograph (Merchant type) is taken with the foot pointing up, the lower edge of the film parallel to the ground, and the knee at 30 degrees flexion. The mean tilt angle of a group of patients with signs and symptoms suggesting patellofemoral malalignment was 12 degrees (+/- 6 degrees); in a similar group of control subjects it was 2 degrees (+/- 2 degrees) (p < 0.01). Tilting of 5 degrees was taken to be the limit of normal. For the detection of patellar malalignment, the tilt angle was almost as specific as the congruence angle (92% v 99%) but more sensitive (85% v 25%) and more accurate (89% v 62%).
Fifty patients who had patellar subluxation and thirty control subjects were examined using axial roentgenograms of the patellofemoral joint that were made with the knee in 30 and 45 degrees of flexion, as well as computed tomography scans that were made with the knee in full extension. The amount of lateral patellar tilt was quantitatively assessed using the lateral patellofemoral angle, as described by Laurin et al., and the congruence angle, as described by Merchant et al. In both the control subjects and the patients, the angle of Laurin et al. changed significantly when the knee was flexed from full extension to 30 degrees. The difference between the groups was statistically significant at each angle of flexion of the knee, and the difference between the groups was most prominent on the computed tomography scans that were made with the knee in full extension (p less than 0.001). In the patients, the average congruence angle (as described by Merchant et al.) was 5 degrees and in the control subjects, -10 degrees. This indicated that, in our patients, the extent of the patellar subluxation was less than that in previously reported series, and, as a result, the sensitivity of the congruence angle in diagnosing patellar subluxation was only 0.30. In contrast, the sensitivity and specificity of the computed tomography scans for diagnosing patellar subluxation were 0.96 and 0.90, respectively--that is, they were higher than the values that were obtained using any axial roentgenograms. Thus, our results indicated that patellar subluxation can be detected more accurately by using computed tomography with the knee in full extension than by using conventional axial roentgenograms.
This retrospective study determined that the outcome from anteromedialization of the tibial tubercle correlates well with the location of patellar articular lesions. Detailed descriptions of patellar articular cartilage lesions were obtained from the operative reports of 36 patients who had anteromedialization performed between February 1984 and March 1994. The patterns fell into four distinct groups. Ten patients with type I (distal) patellar lesions and 13 patients with type II (lateral facet) patellar lesions had 87% good to excellent subjective results, and 100% of these patients said they would have the procedure done again. Nine patients with type III (medial facet) lesions had 55% good to excellent results, and 5 patients with type IV (proximal or diffuse) lesions had only 20% good to excellent results. Patients with type I or II lesions were significantly more likely to have good or excellent results than those with type III or IV lesions. Central trochlear lesions were associated with medial patellar lesions and all patients with central trochlear lesions had poor results. There was no significant correlation between the Outerbridge grading of the patellar lesion and the overall results. Workers' compensation issues diminished the likelihood of a satisfactory outcome by 19%; however, this was not statistically significant. This is the first study to correlate the patellar articular cartilage lesion with outcome after tibial tubercle transfer.
Four cases of failed Hauser procedures were treated with an osteotomy of the patellar tendon insertion and distal realignment. The patellar tendon insertion site was moved as a large bond block and positioned in neutral alignment as well as anterior to its previous position, effectively creating a "modified Maquet effect." Proximal realignment was performed in one patient. Intraoperative assessment of patellar tracking enabled accurate determination of optimal position. The clinical findings and the operative approach are described. All four patients experienced significant improvement from ther preoperative status.
The literature concerning kinematic and kinetic studies on the knee joint is comprehensively reviewed in this article. Also reviewed are studies of etiology and operative treatment of injury, as well as chronic disease such as dislocation, arthritis, and ligamentous rupture. This paper formulates experimental study and mathematical model analysis of the tibio-femoral and patello-femoral joints, respectively. The sections on experimental study cover the following: the tibio-femoral joint including load bearing capacity, knee laxity, ligamentous strain, articular geometry, and multiaxial movement; the patello-femoral joint including forces and stresses and patellar tracking patterns. Further, three items, considered as future problems, are discussed briefly: individual variations in material properties of the soft tissue and biphasic cartilage-bone structures, quantitative description of bone geometry, and quantitative determination of extreme tensions and distortions in connective tissues surrounding the knee.
Five patients with an anterior cruciate ligament (ACL) deficiency accompanied by patellar subluxation who were treated by ACL reconstruction with lateral retinacular release (LRR) are reported. In two patients, the LRR was performed at the same time as the ACL reconstruction, and in three patients, the LRR was performed secondarily. The three patients requiring the secondary LRR needed the procedure to recover knee stability to return to sporting activities. In all patients, the apprehension sign of the patella was subsequently improved. When managing ACL deficiencies in a young athletic population, patellar subluxation should be suspected. In our patients with patellar subluxation accompanying an ACL deficiency, ACL reconstruction with LRR was effective in relieving their instability.
Extensor mechanism complications following 281 knee arthroplasties that included patellar resurfacing, performed by two surgeons in one hospital over a 6-year period, were reviewed. The mean follow-up period was 42 months. There were 28 (10%) extensor mechanism complications: 3 quadriceps tendon ruptures, 5 patellar fractures, 4 patellar tendon ruptures, 11 recurring patellar subluxations, 4 cases of patellar pain, and 1 malrotated patella. Nine (3%) required further surgery. Surgical technique may have contributed to the tendon ruptures; patellar fractures occurred mainly in patients who had rheumatoid arthritis. Patients with patellar subluxation had abnormal preoperative valgus deformities of their knees and presented with this subluxation problem an average of 4 months after surgery, but it appeared to cause them less discomfort with time. Patellar resurfacing as part of a knee arthroplasty procedure is recommended but should be performed with care to the integrity and vasculature of the extensor mechanism.
Twelve closely related members of one family were found to have small or absent patellae. Seven of these patients also had abnormalities of the pelvic girdle and upper femora. There was a resemblance to the nail--patella syndrome in the patellar abnormalities but not in the associated conditions, and it would therefore appear that the syndrome described is a new variety of congenital abnormality of the knee.
A standard diagnostic procedure for patellar luxation is described. It is based upon the patellar luxations grade 1 to 4, which have been published before, and contains additional definitions in terms of the animals positioning toward the examiner.
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.
Twenty patients, victims of a first luxation of the patella, were the object of a retrospective study. They were all subjected to arthroscopic examination during which, in 7 of the patients, the liquid injected under pressure massively escaped into the subcutaneous layer of the medial side of the knee. The patients were divided into 2 groups according to the integrity of the capsule of their knees. Group I consisted of 7 patients, group II of 13 patients. The treatments, the majority of which were conservative, were quite varied, but the post-traumatic functional recuperation was much slower and more variable for the group I patients. These patients presented more significant tissue lesions which certainly contributed to the functional prognosis of the traumatized joint. Seventy two percent of the patients, equally distributed between the 2 groups, presented trochleo-patellar dysplasia. With the exception of age, different clinical parameters (sex, circumstances of the accident, clinical examination) and radiological criteria (external displacement of the patella, detached bony fragment at the interior border of the patella, value of the patellar and trochlear angles, patella alta) did not permit a distinction between the two groups. Because of our results and those in the existing literature we recommend arthroscopy, which is the only examination capable of establishing a complete picture of the lesions and which, in addition, permits rising of the joint and sometimes allows extraction of free osteo-cartilaginous fragments. The younger patients may then benefit from immediate functional reeducation. For older patients, where the tissue lesions are more important, conservative treatment is associated with a slower and sometimes variable functional recuperation. It remains to be determined, whether surgical treatment, adapted to each case, would permit us to obtain better results more rapidly.
Trochlear wedge recession, a surgical technique for correction of luxating patella, has been improved and simplified over the years. Modifications in the technique for the pathologic sulcus are described. Common problems with the osteotomy placement and wedge stability are defined with recommendations for correction.
A wire-suture method was used for correcting grade IV medial and lateral luxations of the patella. In seven operated stifles, the method resulted in a normal gait and minimal valgus and varus deformity of the distal femur and proximal tibia.