Plica mediopatellaris ?Arthroscopic resection under local anesthesia

Archives of Orthopaedic and Traumatic Surgery

Arch Orthop Trauma Surg (1986) 106:18-19

© Springer-Verlag 1986

Plica Mediopatellaris -

Arthroscopic Resection Under Local Anesthesia E Andersen and T D Poulsen Department of Orthopaedic Surgery, Central Hospital, DK-6700 Esbjerg, Denmark

Summary A consecutive series of 28 patients (31 knees) with a symptomatic mediopatellar plica without concomitant lesions excised arthroscopically under local anaesthesia in the outpatient department is described The results were classified as excellent or good in 26/31 cases after a median follow-up period of 15 months It is concluded that excising a fibrosed mediopatellar plica large enough to cover the medial femoral condyle during flexion is followed by good results; local anaesthesia is sufficient and economical, and arthroscopic excision under local anaesthesia carries a low morbidity.

Since the introduction of arthroscopy, increasing attention has been paid to the plicae of the knee joint. Four plicae have been described, of which the mediopatellar plica most often has been classified as symptomatic The mediopatellar plica is a remnant of the embryonic septae of the knee It is situated on the medial wall of the knee joint and follows an oblique course from the undersurface of the medial quadriceps mechanism to the attachment distally into the synovial membrane of the infrapatellar fat pad. When it is subjected to trauma, synovitis and fibrosis may occur. The clinical significance of a mediopatellar plica is still disputed Contemporary reports are often difficult to interpret, as additional lesions are usually present.

A study of 31 consecutive mediopatellar plica resections without concomitant lesions of the knee performed under local anaesthesia in the outpatient department is presented with respect to the symptomatology and the results. Offprint requests to: Erik Andersen, NOrrebrogade 37, Funktionaerbolig 3, DK-8000 Aarhus C, Denmark

Patients and Methods Included in the study were all knees operated on during the years 1983 and 1984 that fulfulled the following criteria: an arthroscopically verified fibrosed mediopatellar plica which bowstringed over the medial femoral condyle during flexion. Excluded were; (a) knees with any lesions other than local chondromalacia of the patella or the medial femoral condyle in relation to the contact area with the plica; (b) knees which had been operated on previously; (c) knees with evidence of old lesions. The material consisted of 28 patients with 31 operated knees There were 20 men and eight women, with a median age of 31 years (15-44) The right knee was involved in 19 cases The median duration of symptoms was 16 months (3 months-18 years). The onset of symptoms was caused by a direct blow to the anteromedial aspect of the knee in seven cases, a twisting injury in another seven, and overuse in repetitive athletic activity in three; in 14 cases no specific injury could be found In ten cases the injury was sustained during athletic activity. Pain was the dominant symptom in 23 cases, pseudolocking in four; combinations of symptoms were present in the rest. The distribution of symptoms is given in Table 1 and the physical findings are listed in Table 2. For resection of the plica the arthroscope was placed in the suprapatellar lateral portal, and a basket forceps was inserted either parallel to the arthroscope or through the anterolateral portal. Local chondromalacia of the patella was noted in two knees and of the medial femoral condyle in three knees. Table 1 Distribution of symptoms Symptom

No of knees

Anteromedial knee pain Pseudolocking Cracking sound Anterolateral knee pain Periodic effusion Retropatellar pain Giving way Locking

26 17 16 9 7 3 3 0

E Andersen and T D Poulsen: Arthroscopic Resection of Plica Mediopatellaris Table 2 Distribution of physical findings No of knees Medial plica tenderness 18 Medial joint line tenderness 12 Cracking sound during flexion 8 Positive patellar compression test 4 Quadriceps atrophy 4 Lateral joint line tenderness 1 Effusion 0

All 31 operations were performed in the outpatient department under local anesthesia (1% lidocaine with epinephrine) without a bloodless field. Follow-up was done by interview and physical examination, with a median follow-up period of 15 months (7-29) The results were classified as follows: excellent the patient was free of symptoms with an unlimited activity level; good there were minor intermittent symptoms only and an unlimited activity level; fair there was only slight improvement and/or a still reduced activity level; poor there was no improvement.

Results At follow-up 12 knees were graded as excellent, 14 as good, five as fair, and none as poor One patient with a fair result had had an excellent result for the first 12 months; there after symptoms gradually recurred, without there having been any additional trauma. Another three patients with fair results had unlimited activity levels. Preoperatively four patients had been on sickleave and eight patients had had a reduced working capacity At follow-up all patients had resumed their previous work. Before the operation 18 patients had stopped or reduced their level of athletic activity At follow-up 16 of these had resumed their athletic activity. Postoperative disability such as pain and/or effusion was experienced in 18 of 31 cases with a median

duration of 10 days ( 1-21), whereas in 13 of 31 cases the patients were able to return to work the day after surgery. No technical difficulties were experienced during the surgery. At follow-up calf atrophy of between 1 and 2 cm was found in five cases; there was medial tenderness in four knees, lateral tenderness in one knee, and retropatellar tenderness in one knee Physical examinations were essentially negative in all other aspects. Discussion The distribution of symptoms in the present series of mediopatellar plicae is in concordance with the fre-

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quencies found in other series, anterior knee pain being the most prominent symptom, often combined with pseudolocking l4, 5, 7l The term "shelf claudication" has been used to describe the characteristic aggravation with activity l4l. The plica is believed to become symptomatic following trauma, leading to synovitis and eventually fibrosis with resultant loss of elasticity l 1, 3, 8 l, and chondromalacia of the patella or the medial femoral condyle may follow l3, 6l. In 26 of 31 knees ( 84%) arthroscopic resection gave good to excellent results, which is comparable to those in other reports l2-5, 7l. Considering the long symptomatic period preoperatively, despite the various conservative measures available we find it plausible that the symptoms in relation to a fibrosed mediopatellar plica large enough to cover the medial femoral condyle during flexion are primarily mechanical, and we feel the treatment of choice to be resection. We did not experience any problems in relation to the use of local anesthesia The treatment under local anesthesia is economical and more satisfactory to the patient, as less preoperative preparations are needed, the hazards of general anesthesia are avoided, and the patient is able to return home immediately after the operation. Thus, we recommend that the condition be diagnosed and treated arthroscopically Furthermore, we recommend that the operation be performed under local anesthesia, as it carries a low morbidity and is the most economical way. References 1 Hardaker WT, Whipple TL, Bassett FH (1980) Diagnosis and treatment of the plica syndrome of the knee J Bone Joint Surg lAml 62:221-225 2 Klein W (1983) The medial shelf of the knee Arch Orthop Trauma Surg 102:67-72 3 Munzinger U, Ruckstuhl J, Scherrer H, Gschwend N (1979) Internal derangement of the knee joint due to pathologic synovial folds: the mediopatellar plica syndrome Clin Orthop 155:59-64 4 Nottage WM, Sprague NF, Auerbach BJ, Shahriaree H (1983) The medial patellar plica syndrome Am J Sports Med 11:211-214 5 Richmond JC, McGinty JB (1983) Segmental arthroscopic resection of the hypertrophic mediopatellar plica Clin Orthop 178: 185-189 6 Schulitz KP, Hille E, Kochs W (1983) The importance of the mediopatellar synovial plica for chondromalacia patellae Arch Orthop Trauma Surg 102: 37-44 7 Vaughan-Lane T, Dandy DJ (1982) The synovial shelf syndrome J Bone Joint Surg lBrl 64:475-476 8 Whipple TL, Hardaker WT (1985) Symtomatic plica and shelf syndromes in knee Orthop Rev 14:61-64 Received January 15, 1986