Search

This review focuses on the complications of extensor mechanism surgery for symptomatic patellar malalignment and ways to avoid those complications. We combined a review of new and referred patients who had complications resulting from extensor mechanism surgery with a review of selected literature specifically addressing similar complications. By studying the pathologic anatomy at the time of arthrotomy, it was possible in many cases to determine the causes of adverse outcomes with this type of surgery. The complications of extensor mechanism surgery can be avoided by performing a thorough preoperative evaluation, determining each component of the malalignment, tailoring the procedure to correct each patient's unique pathomechanics, and respecting the functional anatomy of the extensor mechanism.

Twenty-five cases of diffuse pigmented villonodular synovitis of the knee in 23 patients were reviewed to determine the results of surgical treatment. All the cases met strict histologic criteria for diagnosis. Long-term clinical follow-up data (average, 58 months) were available for all patients. One case for a patient who was treated by marginal excision recurred within one year. All other cases (initial and recurrent) were treated by total synovectomy, preserving the functional integrity of the knee. Proximal extensor realignments were performed in patients in which chronic distention had caused a redundancy of retinacular tissues. Adhesions, an early complication in eight patients, responded well to closed manipulation and did not adversely affect long-term functional outcome. The outcome was excellent in seven and good in 16 the patients. Two of the patients have had recurrences but have not had another operation. Using this technique, the recurrence rate (8%) and morbidity are significantly lower than those reported previously.

Twenty-five cases of diffuse pigmented villonodular synovitis of the knee in 23 patients were reviewed to identify characteristic clinical presentations and histologic findings. All cases met strict histologic criteria for diagnosis. Clinical presentation consisted of insidious and progressive symptoms of significant joint swelling with discomfort, but not isolated pain. On physical examination, a suprapatellar pouch that was markedly distended by either effusion, synovial masses, or both, and a slight flexion posture were the most consistent findings. Aspiration to detect a bloody effusion was unreliable as a diagnostic tool. Pigmentation was absent in 16% of the gross specimens. Histologically, iron deposition was present in all cases and to a moderate or marked degree in most. Fibrosis, hyalinization, and chronic inflammatory changes were present in most, but to a lesser degree. No patient had gross, histologic, or treatment follow-up findings consistent with neoplasia. Attempts to predict clinical outcome based on histologic findings were unrewarding.

Results of treating 238 transverse, longitudinal, and osteochondral fractures of the patella are reviewed. Of these, 89 patients had partial patellectomy and extensor mechanism reconstruction. After an average follow-up of four years, functional results have been excellent; there have been no late patellectomies and traumatic arthritis has not developed. Total patellectomy is recommended only when the entire patella is so severely comminuted that none of it can be used as part of the extensor mechanism of the knee.

Adequate hemostasis is extremely important in extensor reconstruction of the knee and possibly all knee injury. Hemarthrosis postoperatively contributes to postoperative discomfort and may increase the risk of infection. Hematoma formation is also responsible for neurovascular complications. Peroneal nerve palsies were associated with hematoma formation in this series and probably represented a pressure palsy. Release of the tourniquet with good hemostasis and a pressure dressing prior to cast application will aid in the prevention of hemarthroses and consequent neurovascular complications. Peroneal nerve palsy is probably more common in reconstruction of the extensor mechanism of the knee than has previously been reported.

The posterior cruciate ligament, situated near the center of the knee, functions as the basic stabilizer and is located close to the axis of motion. We diagnosed and repaired thirty-two consecutive acute tears of the posterior cruciate ligament associated with tears of medial or lateral-compartment ligaments, or of both. Of the twenty-nine knees that we could evaluate, twenty-three demonstrated a 2+ to 3+ positive abduction or adduction stress test done in maximum extension and a positive anterior drawer test done in maximum internal rotation, while only nine had a definitely positive posterior drawer test. In all knees we repaired the tears, using the medial meniscus as a graft in nine knees in which the repair of the posterior cruciate ligament did not produce immediate adequate stability at operation. Five to sixteen years after operation, twenty of these twenty-nine knees were available for evaluation. The objective results were good in thirteen, fair in four, and poor in three.

We reviewed the clinical records and operative notes of seventeen consecutive patients who were treated by surgical repair for acute posterolateral rotatory instability in order to determine the diagnostic features of the instability and the effectiveness of our surgical repair in thirteen patients who returned for objective and subjective evaluation after a mean follow-up of 53.3 months. Sixteen of the seventeen knees had a positive external-rotation recurvatum test; fifteen, a positive adduction-stress test at 30 degrees of knee flexion; and twelve, a positive posterolateral-drawer test. Associated rotatory instabilities were found in ten of the seventeen knees, with anterolateral rotatory instability being the most frequent. Two patients had associated peroneal-nerve palsy. One or more components of the arcuate ligament complex were injured in all seventeen knees. None of the thirteen patients who were followed required subsequent reconstruction for any chronic instability. Of these thirteen, the results in 85 per cent were rated good subjectively and in 77 per cent, good objectively. Eighty-five per cent of these patients had returned to athletic activity at their preinjury level; the remaining 15 per cent did not participate in sports activities. A positive posterolateral-drawer test or external rotation recurvatum test, or both, was diagnostic of posterolateral rotatory instability. The adduction stress test at 30 degrees of knee flexion was usually positive, but was not diagnostic. Accurate diagnosis and treatment of posterolateral rotatory instability in the acute stage can result in subjectively and objectively acceptable knee function.

Because the results of treatment of osteochondritis dissecans of the femoral condyles are still not consistently satisfactory, we reviewed the cases of eighty-three patients (ninety-five knees) with osteochondritis dissecans who were followed for two to thirty-one years to identify factors that may influence treatment and long-term prognosis. Of the eighty-three patients, sixteen had only non-surgical treatment, sixty-five had only surgical treatment, and two had non-surgical treatment of one knee and surgical treatment of the other. Of the twenty-two knees (eighteen patients) that were treated non-surgically, fifteen were treated before and seven were treated after distal femoral epiphyseal closure. Of the seventy-three knees (in sixty-seven patients) that were treated surgically because of persisting symptoms, twenty-three were treated before epiphyseal closure and fifty, after closure. At follow-up, each knee was given a rating of excellent, good, fair, poor, or failure, and a corresponding point score. Seventy-seven per cent of the knees in the surgical group and 82 per cent of those in the conservatively treated group were rated either excellent or good. The average scores in both groups were higher in knees in which the osteochondritic defect was small and was treated before epiphyseal closure, and in knees in which the fragment healed as compared with the ones from which the fragment was removed. We found that knees with osteochondritis dissecans of the femoral condyles that had no other abnormal physical findings or functional disability responded well to conservative treatment before epiphyseal closure.(ABSTRACT TRUNCATED AT 250 WORDS)

A Miyakawa patellectomy was done in seventeen patients (twenty knees) for either osteoarthritis or chondromalacia of the patella, or both, secondary to malfunction of the extensor mechanism. Patients who had had a patellar fracture were not included in the series. The Miyakawa patellectomy realigns the extensor mechanism, with the proper tension, and centers the functional pull of the quadriceps tendon and patellar ligament. A superficial strip of the quadriceps tendon is pulled distally to fill the void that was left by removal of the patella and to maintain proper length. The musculotendinous portions of the vastus lateralis and vastus medialis are advanced over this defect in the midline and are sutured to the quadriceps tendon. The average length of follow-up was 13.8 years (range, 3.6 to 31.7 years). Nineteen of the twenty knees had a good or excellent subjective result and eighteen had a good or excellent objective result. No subsequent surgical treatment was needed for problems that were caused by malfunction of the extensor mechanism of the knee.

Twenty-nine cases of pigmented villonodular synovitis (PVS) of the knee in 27 patients were reviewed to determine characteristic roentgenographic findings. All cases met strict histologic criteria for diagnosis. Four cases were localized PVS (LPVS), and 25 cases were diffuse PVS (DPVS). Roentgenographic findings were largely in the soft tissues. Cystic invasion of bone or degenerative changes were rare, although present in some cases. When present in DPVS, these changes were most pronounced in the patellofemoral articular surface. In the cases of DPVS, large posterior tumefactions did not correlate with extraarticular extension. Clinical behavior of PVS was governed more by anatomic site and form of disease than by the severity of histologic or roentgenographic findings.