Varus Instability Research Articles

Anterior cruciate ligament insufficiency treated by combined medial and lateral extra-articular reconstruction.

Thirty patients who required surgery for an unstable knee with "giving way" symptoms were operated during 1979-1981 with a pes anserinus transfer and an Ellison procedure at the same séance. All patients had an insufficient anterior cruciate ligament prior to surgery. Of these 24 patients had a positive pivot-shift test, and 26 patients had an anteromedial rotatory instability. Twenty-eight patients were seen at a follow-up after an average of 28 months (range 19-49). There were 12 women and 16 men, with a mean age of 28 years. Eleven patients (39%) declared that their knee function was distinctly improved, and six (21%) that it was moderately improved after surgery. Knee function was unchanged for ten patients (36%), and one patient said that the knee function had deteriorated after surgery. The functional result was not correlated with the duration of symptoms or with the follow-up time. Physical examination revealed that the anterior drawer had not disappeared for any of the patients. A positive pivot-shift sign was still present in 18 patients, and 23 patients displayed an increased varus instability.--All but six patients still had some instability experiences, and most of them could not completely return to active sports. However, the method could provide an alternative for patients engaged in frequent but not heavy physical activity.

The posterior cruciate ligament and rotatory knee instability. An experimental study.

The importance of the posterior cruciate ligament in relation to valgus-varus and axial rotatory stability in the knee joint was investigated. Mobility patterns were drawn from 20 osteoligamentous preparations after successive transection of the posterior cruciate ligament (PCL), the medial and lateral collateral ligaments, and the posterior joint capsule. The knee joint remained grossly stable after isolated transection of the PCL, and further cutting of either one of the collateral ligaments or of the posterior capsule yielded no greater instability than one should expect from isolated cutting of each of these structures. The posterior cruciate ligament was the stabilizing factor in flexion and external rotation after injury to the lateral collateral ligament and the posterolateral capsule, and it restricted internal rotation after cutting of the medial cruciate ligament and the posteromedial capsule. Valgus instability was markedly increased during the whole range of movement when PCL was included in injury to the medial compartment ligaments, and when included in a lateral compartment injury a further varus instability was found, though only in the flexed or semiflexed knee. No hyperextension could be demonstrated after these injuries.

The anterior cruciate ligament of the knee: an experimental study of its importance in rotatory knee instability.

The importance of the anterior cruciate ligament (ACL) in relation to valgus-varus and axial rotation stability in the knee joint was investigated. Mobility patterns were drawn from ten osteoligamentous preparations after successive transection of the two parts of the ACL and the medial (MCL) and lateral collateral ligaments (LCL). The knee joint remained grossly stable after partial injury of the ACL, while sectioning of the entire ACL caused an increase in internal rotation in the extended-semiflexed position. Combined lesions to the ACL and the MCL caused considerable valgus instability increasing with flexion, the joints remaining stable in extension. Moreover, marked anteromedial instability occurred, while only slight posteromedial instability was found. Combined lesions to the ACL and the LCL caused varus instability, worst in the semiflexed position, and a consistent pivot shift in applying a valgus torque in flexion was noted. Moreover, moderate posterolateral instability was found, at its maximum in the semiflexed position. External rotatory stability is secured primarily by the MCL, secondarily by the posterior medial capsule, and finally by the ACL. The existence of lateral pivot shift is proof of damage to the ACL.

Instability of cadaver knees after transection of capsule and ligaments.

The importance of the medial collateral ligament and the anterior cruciate ligament of the knee in relation to valgus and varus instability was investigated. Mobility patterns were drawn from ten osteoligamentous knee preparations after successive transections of the structures. Cutting the entire collateral medial ligament caused only slight valgus instability, even when the knee was flexed. Further transection of the anterior cruciate ligament increased the instability considerably, but the knee remained stable in extension. The valgus instability after the transections was maximal at about 60 degrees of flexion.

Posterior cruciate ligament insufficiency. A review of the literature.

A review of the English language literature establishes athletic mishaps as a major cause of posterior cruciate ligament injury. However, diversity of opinion exists regarding the functional significance of the lesion, its occurrence as an isolated entity, and the roles of conservative and surgical management. The posterior cruciate ligament is a composite structure, consisting of a superficial tibiofemoral and meniscofemoral portion and a deep tibiofemoral portion. The structure is intra-articular but extrasynovial, coursing from its attachment to the lateral surface of the medial femoral condyle posteriorly and inferiorly to its distal attachment into the posterior rim of the tibia, blending with the capsule and periosteum. Mechanical studies have demonstrated that abnormal posterior tibial displacement can occur only with posterior cruciate ligament laxity. The most prevalent mechanism resulting in injury to the posterior cruciate results from a blow on the anterior aspect of the flexed knee. However, both hyperflexion and hyperextension as well as deceleration and rotation have been described. Posterior cruciate ligament insufficiency may result from an avulsion fracture involving the ligament-bone insertion of the ligament, usually from the posterior aspect of the proximal tibia. Also, disruption may occur as an intersubstance tear of the ligament, either as an isolated phenomenon or in combination with multiple ligamentous injuries. The importance of distinguishing between combined injuries associated with significant collateral and/or anterior cruciate ligament injuries from the 'isolated' type lies in the fact that the prognosis for the 'isolated' injuries is much better. Careful clinical evaluation of the knee with an acute posterior cruciate ligament injury will reveal subtle, but definite, findings peculiar to the lesion. These include the posterior sag sign, the posterior drawer sign, reverse pivot shift, Godfrey's test, and the presence of varus or valgus instability with the joint in full extension. In patients with chronic posterior cruciate ligament laxity, the presenting symptom is often that of patellar pain. It is generally agreed that avulsion fractures involving the ligament-bone insertion of the posterior cruciate ligament should be treated by open reduction and internal fixation. Surgical treatment of this lesion will result in excellent functional recovery. A variety of procedures have been reported for the management of acute disruption of the posterior cruciate ligament.(ABSTRACT TRUNCATED AT 400 WORDS)

Acute posterolateral rotatory instability of the knee.

Posterolateral rotatory instability of the knee, a poste rior rotational subluxation of the lateral tibial plateau in relation to the lateral femoral condyle, is an unusual condition. Twelve cases of acute posterolateral rotatory instability are presented with an average followup of 7.5 years after surgical repair. Clinical signs suggestive of this injury included posterolateral knee tenderness, and a contusion or abrasion over the anteromedial aspect of the tibia. Indications for operative repair in cluded a 2+ or greater varus instability of the knee at 30° flexion in association with a positive external rota tion recurvatum or posterolateral drawer test. At oper ation, the consistent finding was a tear in the arcuate ligament complex in all patients. Primary operative repair resulted in stable and func tional knees in 8 of 11 patients without evidence of degenerative joint disease at 7½ years postinjury. Roentgenographic evidence of degenerative joint dis ease was present in three patients, two of whom had some residual posterolateral laxity. Results were evaluated subjectively, objectively, and functionally. There were eight good, three fair, and no poor subjective results; eight good, two fair, and one poor objective results; and seven good, three fair and one poor functional results. The single objective and functional poor result had a deep infection postopera tively. Eight of the 11 patients participated in recreational sports following repair and no patients were limited in the activities of daily living.

Medial Epicondyle Osteotomy as an Approach to Repair of Medial Femoral Condyle Fractures in the Dog

Fracture of the medial femoral condyle in three dogs is described. This injury resulted in lateral (varus) instability, which was difficult to differentiate from a lateral collateral ligament tear. Radiographs and surgical exploration were necessary to differentiate the two conditions. A medial femoral epicondyle osteotomy was used in two cases to expose the fracture. This exposure technique is advantageous because it allows early return to functional use of the injured limb by eliminating postoperative splintage.

Anterolateral rotatory instability of the knee

In an attempt to correct anterolateral rotatory instability of the knee, 30 consecutive patients underwent a surgical procedure similar to that described by Ellison (Ellison AE: A modified procedure for the extra-articular replacement of the anterior cruciate ligament. American Orthopaedic Society for Sports Medicine Symposium, New Orleans, LA, July 15, 1975), called the iliotibial band transfer. Fashioning the passageway for the transfer closer to the attachment of the fibular collateral ligament on the femur and meticulous fascial closure over the transplant were not found to be crucial to success. Twenty-nine of the 30 patients were injured during athletic activities, and the remaining patient was injured in a motorcycle accident. They often complained of an unstable knee with symptoms of pain and giving way. Twenty-eight patients with a minimum followup of nine months (the average followup was 25 months) were evaluated subjectively by an interview and by objective clinical examination. Subjective results (including asymptomatic return to their previous level of athletic activity) and clinical improvement of anterolateral rotatory instability (based on the flexion-extension-valgus test or the Slocum anterolateral rotatory instability test) were encouraging. Areas of concern were that a small number of patients developed asymptomatic varus instability and a few had relative strength deficits which may or may not have long-term significance.

Iliotibial band transfer for anterolateral rotatory instability of the knee

Forty-eight patients who underwent distal iliotibial band trans fer (Ellison) for anterolateral rotatory instability and who were over 1 year postsurgery presented for examination and an additional six patients completed a written subjective evalua tion. Five patients only had isolated lateral surgery. In 33 patients there was an additional diagnosis of anteromedial rotatory instability. Of the patients 44% had had no previous surgery, while 36% had undergone one procedure and 19% had undergone more than one procedure. In combination with iliotibial band transfer, 74% had a lateral meniscectomy, 44% had a capsular reefing, 38% had a medial meniscectomy, 44% had a pes anserinus transfer, and 8 patients had prosthetic cruciate ligament replacement. In these eight patients, five prosthetic ligaments had fractured and were included but three were intact and were excluded. Thirty-four percent of the patients were initially injured in football. All patients had thorough knee and radiographic examinations; strength mea surements by using the Cybex testing for knee extension; flexion and external rotation; and completed a subjective ques tionnaire. Of the patients 87% responded that they were im proved and thought the surgery was worthwhile. Ninety-one percent had positive jerk tests preoperatively but only 46% were positive at followup. However, while 53% reported no episodes of giving way, 28% reported monthly episodes, 9% weekly episodes, and 8% daily episodes. Only 15% had no difficulty cutting while 55% had some and 26% had extreme difficulty or were unable to do so. Only 23% reported no difficulty with jumping, but 48% had some difficulty, and 30% were unable to jump and had extreme difficulty jumping. Only 28% of patients had returned to their desired level of activity while 46% had reached only 50% of their desired level. Only 13% expressed complete confidence in the knee while 21 (46%) were in the 75 to 90% confidence range, while 22% had less than 50% confidence. Of the patients 29% had lost extension and 57% had lost flexion. Ninety-one percent had increased varus (adduction) instability at followup, but this did not appear to have clinical significance. On follow-up x-ray films 70% had osteophyte formation, 65% had joint space narrowing, 46% had pain requiring aspirin. Eighty percent had atrophy averaging 1.72 cm. Thirty percent had tenderness at Gerdy's tubercle. As in all studies involving the knee ligaments, the many variables are dependent and poor results do not reflect failure of this one part of treatment. No patient was made worse by the procedure; there appears to be defmite reduction in anterolateral rotatory instability after iliotibial band transfer, which was maintained for more than 1 year after surgery.

Extension deficit and lateral instability in degenerative disease of the knee.

During the period October 1975-June 1977, 70 Marmor knee arthroplasties were performed. The operative procedure provided a good opportunity to study the anatomical conditions in vivo. The causes of extension deficit and lateral instability of the knees were analysed in a prospective investigation. Thirty-seven out of 69 knees had an extension deficit exceeding 10 degrees preoperatively. At operation a bony impediment to extension was found in 32 of these 37 knees, and by removal of this obstruction the extension deficit was relieved in 31 of the knees. At radiography a bony impediment was demonstrated preoperatively as a cause of an extension deficit in 29 of the 32 knees. No false positive diagnosis was made radiographyically. Varus or valgus instability exceeding 5 degrees was observed preoperatively in 42 of the the 70 knees. Lateral stability was achieved in all knees at operation by compensating for the intra-articular loss of cartilage and bone with the Marmor module system. Macroscopically intact collateral ligaments were found in all knee joints even in those severely affected by rheumatoid arthritis. All knees except three showed lateral stability 1 year postoperatively.

INSTABILITY OF THE FOOT AFFER INJURIES TO THE LATERAL LIGAMENT OF THE ANKLE

1. Forty-two previously asymptomatic patients presenting with a recent rupture of the lateral ligament of the ankle, and twenty similar patients with a simple sprain of this ligament, have been followed for one year. The physical and radiological findings upon the completion of treatment have been related to functional instability of the foot one year later. 2. Persistent mechanical varus instability of the talus in the ankle mortise was a possible cause of functional instability one year after injury in four (or perhaps six) patients. 3. Adhesion formation was a possible cause of functional instability in one patient. 4. Seventeen patients finally displayed no clinical or radiological abnormality after injury, but noted functional instability of the foot one year later. 5. It is concluded that the pathological process which is usually responsible for functional instability of the foot after a lateral ligament injury is at present unknown.