Scand JHaematol - Supp140, Vol33, 1984,249-262

Arthroscopic Synovectomy of the Knee Joint with the Electric Resectoscope

H ARITOMI

Department of Orthopedic Surgery, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan

The design and function of electric resectoscope, consisting of arthroscopy with an electric surgical knife, is described in association with the technique of arthroscopic surgery in the knee joint of non-hemophilic patients.

Arthroscopic surgery with the electric resectoscope can extend its indication to synovec- tomy and removal of loose bodies as well as cartilage shaving. Clinical follow-up results sug gested that this arthroscopic synovectomy demonstrated almost comparable results to those of conventional synovectomy.

The advantages of arthroscopic surgery with the electric resectoscope are the following: It can perform arthroscopic surgery as well as synovectomy with resectoscope through small skin incision. It can effect intraarticular hemostasis by electrocoagulation with resectoscope. Postoperative pain is far less than the conventional synovectomy. It offers much more rapid recovery of range of motion of the joint without any manipulation post-operatively. Con- sequently, it shortens the period of hospitalization.

None of the complications were serious except for two episodes of infection with Pseudo- monas during the early practice of this technique.

K e y words: Synovitis, Arthroscopic synovectomy, Arthroscopic surgery, Synovectomy, Arthroscopy, Rheumatoid arthritis

Correspondence to: Hiroshi Aritomi, M.D., Department of Orthopedic Surgery, Kitasato University School of Medicine, 1-1 5-1 Kitasato, Sagamihara, Kanagawa 228, Japan

Arthroscopic surgery (O'Connor 1977, Watanabe et a1 1969) has become gradu- ally widely accepted as a surgical treat- ment of the knee joint. Employment of the modified urological electric resecto- scope, equipped arthroscope with an elec- tric surgical knife, in the knee joint sug- gested that it might be beneficial to arthroscopic synovectomy and surgery. Since 1972, we have used this instrument clinically to overcome the problems of conventional synovectomy, such as post- operative disturbance in recovery of range of motion.

DESIGN AND FUNCTION OF THE ELECTRIC RESECTOSCOPE

The Iglesias electric resectoscope has been improved and well modified for arthroscopic surgery in the knee joint. This instrument can be easily operated with one hand (Figure 1 ) .

The foreoblique telescope This telescope is an endoscope in a dia- meter of 4.9 mm with oblique or square distal tip. The length varies according to its use. The recent development of a cold

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Figure 1 . The structure of the modified Iglesias resectoscope, model A. Right below: Magnified view of the loop.

illuminaton source by the use of fiber- glass has made it possible to widen the angle of view to a field of 90 degres. Since a wide angle lens has a lower magni- fication and the loop in the visual field of the scope appears to be small and distant from the resectoscope, the angle of view in the latest model has been de- creased to 70 degrees.

The loop As shown in Figure 1, the loop is a semi- circular tungsten wire, which extends between two insulated conductors through which a high frequency current flows. The shape of the loop may be se- lected in the form of a button, a rod, a hook, or a semicircular plate according to its purpose.

The working element The working element consists of a struc- ture that controls the loop. It is fixed to

the foreoblique telescope and fits within the sheath.

Pressure on the operating handle brings the loop to move beyond the distal tip of the foreoblique resectoscope. When pressure is released, the loop returns to its initial position with a plate-spring sys- tem. During manipulation of the instru- ment, the loop moves into and out of the field of vision. Electrical current is then adequately supplied by means of an appropriate connection with foot switch.

The sheath The sheath consists of a silicone cylinder with a beaklike distal tip, which protects the foreoblique telescope and loop. The irrigating fluid flows through it. At its proximal end the sheath has a valve that controls the flow of irrigation fluid. A spring catchlock secures the working ele- ment within the sheath. The resectoscope and the loop are protected from damage

25 1 ARTHROSCOPIC ELECTRIC SYNOVECTOMY

Figure 2. Use of the electric resectoscope for synovectomy in rheumatoid knee joint. The operator dons a sterile hood prior to putting on the conventional surgical gown

as they nestle within the protective tube, which extends 1 mm beyond them. Al- though sheath sizes vary between 16 F (5.0 mm) and 30 F (10 mm), a 16 F (5 mm) and 26 F (8.6 mm) sheath are usually employed in the knee joint.

The operative equipment A power source for the loop and appro- priate cutting and coagulating currents are necessary to carry out surgery. The high frequency current produced by this instrument varies from 1.5 to 5 mega- cycles. The tube oscillating circuit gene- rates the cutting currents, and the spark gap oscillating circuit generates the coagulating current, while the blended current produced mixing the two cur- rents coagulates as well as resects. Switch- ing from one of these currents to the other is controlled by a foot pedal. The metal plates for earth, usually placed on the buttocks, needed to complete the

electrical circuit should be as close as possible to the area of surgery. Although many electrical current sources are avail- able, the Bovie (USA) and Mizuho GT-S4 (Japanese) devices were used in our hospital.

Irrigation apparatus The irrigating solution is usually set in a covered container with a capacity of 5.0 liters. This is suspended from the ceiling or from a stand in the theatre. The con- tainer for irrigating fluid is placed 50 to 60 cm above the operating table. The fluid pressure varies between approxi- mately 80 and 40 cm of water, depend- ing on the level of the irrigating fluid above the operating table.

The cleaning device A cleaning device is prepared to remove resected tissue or blood clots form the joint cavity and to clean inside the joint

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Figure 3. Intra-articular positioning of the electric resectoscope and its loop, and practice of arthroscopic surgery.

after synovectomy and arthroscopic sur- gery with the electrical resectoscope.

STERILIZATION OF THE RESECTOSCOPE AND PREPARATION OF THE IRRIGATING

SOLUTION

The electric resectoscope is separated into its various elements. The device may then be sterilized by ethylene dioxide or formalin gas in a special container.

Although various types of irrigating fluid may be used, diluted Cytal (Cutter, U.S.A.), a non-electrolytic isotonic irri- gating solution, is preferred.

PREPARATION OF THE OPERATING ROOM

Dimming of the general lighting avoids blinding reflections. An adjustable ope- rating table aids in the proper positioning of the patient’s knee so that the surgeon’s hands are available for manipulation of the resectoscope. Finally, proper drainage facilities are essential and irrigation pouch is quite useful for the purpose.

SYNOVECTOMY USING THE ELECTRIC RESECTOSCOPE

When synovectomy with the electric re- sectoscope is proposed, the patient is placed in the supine position. The knee is kept taut, but it should also be able to be flexed during surgery. Because of the irrigation required, additional waterproof drapes are necessary.

Although general or epidural anesthesia may be used, general anesthesia is pre- ferable in cases requiring extensive or prolonged procedures.

No assistant is needed for this method of synovectomy. In addition to a conven- tional type of operating gown, the sur- geon wears a sterile hood (Figure 2).

A small skin incision is made at the inferomedial or inferolateral patellar pole. By making the wound slightly larger than the diameter of the resectoscope, fairly free access to the joint is obtained. Adequate joint distention with a non- electrolytic irrigating solution is essential. After the joint cavity has been thoroughly inspected, synovial resection is performed (Figure 3). During synovectomy the loop is fully extended into the field of vision. As the device is gently pressed against the synovial membrane, the cutting cur-

ARTHROSCOPIC ELECTRIC SYNOVECTOMY 253

Figure 4. Synovial tissue resected with the electric resectoscope ( 2 1 .O gr, 64 year old female).

rent is supplied for resection of the diseased tissue. Because of its fragility, the loop must be manipulated with ex- treme gentleness. Any tissue that adheres to the loop must be removed (Figure 4). Removal of loose bodies has also been attempted after cutting the stalk. Gentle manipulation of the wire loop with the aid of a small grasping forceps is essen- tial.

The red turbidity caused by bleeding from the site of resection can usually be controlled by adequate irrigation. Active “pumpers” require coagulation. A pneu- matic tourniquet may be used. Areas that present limited accessibility may often be treated by blending the cutting and coagulating currents. The fully ex- tended loop will usually reach these sites.

When resection is satisfactorily ac- complished, the joint cavity is washed out fully with physiologic saline solution or irrigating fluid to remove the resected tissue and blood clots. The wound is then closed.

POSTOPERATIVE TREATMENT

After operation a compression bandage is asylied to the knee joint without any plaster splint and the leg is maintained elevated with the knee in slightflexion. On the first postoperative day the patient is encouraged to flex and extend the knee within limits of pain. Weight bear- ing as tolerated is encouraged on the third day. Most patients can ambulate with minimal pain. A normal range of motion is usually recovered rapidly. It is advisable to aspirate the occasional joint effusion that persists for more than one week. Usually, however, the patient can be discharged from the hospital after the third or fourth postoperative day.

CLINICAL RESULTS

Synovectomy with the electric resecto- scope was carried out in 75 joints of 67 non-hemophilic patients with knee joint

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TABLE 1.

Clinical cases for Synovectomy with Electric Resectoscope (SER) and Arthroscopic Surgery (1972-1982)

1 . S.E.R.

rheumatoid arthritis . .................. 31 cases (38 joints)

laris) ......... 9cases (10 joints)

pigmented villonodular synovitis .................. 3cases ( 3 joints)

2. S.E.R. for the purpose of biopsy only ............ lacases (18 joints)

3. anterior conventional synovectomy or debridement following S.E.R.

rheumatoid arthritis .................. 3 cases (3 joints)

tuberculosis ............................................. 1 case (1 joint)

pigmented villonodular synovitis .................. 1 case (1 joint)

chronic synovitls ....................................... 1 case (1 joint)

4 . Resection of phca synovialis infrapatellaris...... 6cases (6 joints)

5 . Removal of intraarticular loose bodies ............ Scases (5 joints)

6 . Shavmg of cartilage fibrillation due to

(medial shelf syndrome)

chondromalacia patellae ........................... 5cases (6 jants)

Total 83cases (92 joints) .........................................................

pain or arthritis. Their ages ranged from 16 to 84 years. Twelve were males and 55, females (Table 1). In 18 cases the aim of the operation was observation of the surface of the synovial membrane and biopsy. In six other cases resection of the anterior synovial membrane and debridement were carried out following establishment of the diagnosis by biopsy. In 34 cases the operation was carried out because of rheumatoid arthritis, with observation of progress. The indications for operation in these patients were per- sistent marked symptoms of inflamma- tion, such as pain, swelling of the knee joint, or effusion, which resulted from chronic disease for at least six months. One merit of the electric resectoscope is that it can be used in conjunction with conventional arthroscopic examina- tion and to perform biopsy at the same time. In this manner, various diagnoses were established after careful observa- tion of the biopsy tissue. Debridement of the knee joint was carried out when

indicated. In three patients with chronic rheu-

matoid arthritis, conventional resection of the anterior synovial membrane was performed after use of the resectoscope. Manipulation under general anesthesia was necessary two to three weeks after the operation in all patients so treated. In the other 38 joints in 3 1 patients with chronic rheumatoid arthritis, synovec- tomy was performed only with the elec- tric resectoscope.

By observation of the synovial mem- brane with the resectoscope in the joint cavity, two types of change were noted - hypotrophic and hypertrophic. In the former case, the synovial membrane shows congestion and swelling. However, the proliferative villus formation of the synovium is observed only around the patella and recessus area. Inflammation seems to be relatively mild. On the other hand, the hypertrophic joint shows marked inflammation of the synovium and marked proliferation of villi through- out the joint cavity.

Hypotrophic changes were observed in eight cases and hypertrophic changes in seven. The weight of the resected synovial membrane was 5 to 12 gm in the hypotrophic cases and 8 to 26 gm in the hypertrophic cases. Since we began to inject 1 per cent osmic acid into the joint prior to use of the resectoscope, this kind of classification has been im- possible.

Findings on postoperative examina- tion at the follow-up are just as shown in Table 2. Generally speaking, postopera- tive pain was rare, possibly because of the small skin incision and of subsidence of joint inflammation. Also the pain as-

ARTHROSCOPIC ELECTRIC SYNOVECTOMY 25 5

TABLE 2.

Clinical Result of Synovectomy with the Electric Resectoscope (SER) for Rheumatoid Arthritis

(31 cases 38joints) (Dec. 1982)

1 % Osmic acid injected) prior t o SER

following-up period (20cases 21 joints) 5 months to 6year 1 months (5 months to 5 year 1 months)

average following-up period 42.2 months (35.3 months)

Excellent

Good

Fair

Poor

stage in X-ray I II a

no pain no effusion

slight pain on motion 2 (1) 4 (0) 9(5) occa sional effusion

occa sionally painful 1 (1 ) 2 ( 1 ) 5*(4) frequent effusion

painful 1 (0) 2*(0) 0 (0) prof use effusion

total 6 (3) 12*(4) 2414)

( * ; infected case)

total %

12(9) 31.6 (42.9) I

(71.4%) 15(6) 39.5

(28.5)

8 (6)

3 (0)

38 (21 )

sociated with motion was either minimal or absent.

Five joints with stage 111 changes on X-ray examination began to show syno- vial effusions again six to seven weeks after operation. One or two separate steroid injections were given after joint aspiration. However, the number of in- jections required to control the effusion has been greatly reduced. In spite of cur- rent effusion in some instances, joint Pain has been significantly decreased following synovectomy with the resecto- scope.

In order to determine the amount of synovial membrane resected and its ef- fect, scanning of the joint with 99mtech-

netium pertechnetate was performed. In some cases uptake of 0 9 m technetium pertechnetate was markedly reduced corn pared with preoperative uptake. These findings almost coincide with the subsid- ence of inflammatory activity.

After operation the range of joint mo- tion in most cases returned at least to its initial degrees in four to five days. In some cases the range increased, whereas in other cases a slight loss of approxi- mately 10 to 20 degrees was noted. Significant atrophy or decrease in power of the quadriceps femoris was not ob- served. The clinical results of arthroscopic synovectomy with the electric resecto- scope in chronic synovitis (Hydrops arti-

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TABLE 3.

Clinical Results of Arthroscopic Synovectomy with Electric Resectoscope in Chronic Synovitis (Hydrops articularis genus) and pigmented Villonodular Synovitis (Dec. 1982)

pigmented villonodular synovitis (3 cases. 3 joints)

chronic synovitis ( intra-articularly

following-up 3 months to 4 year 6 months (17.4 months) period

(average) I OA changes

3months to 3year 6months (22.7 months)

Excellent 2 (no pain, no effusion)

Good slight pain on motion ( occasional effusion

occasional pain rr frequent effusion

Poor

2 (1) ) 1 1

1*

1 1 1 9 Total

lO(7)

cularis genus) and pigment villonodular synovitis are shown in Table 3. On com- parison with that in rheumatoid arthritis, better results are noted even though in relatively short following-up period.

A case with localized nodular synovitis is presented in Figures 5 , 6 and 7.

As for complications, postoperative bloody joint effusion was observed in one case (Table 4). Infection withpseudo- monm aeruginosa occurred in two other cases. The infection was controlled during rehospitalization by continuous irrigation of the joint with large amounts of physi- ologic saline solution containing antibio- tics. Irrigating fluid reactions are re- ported in urologic patients, but with the

(7) I 3

* conventional synovectomy ( was followed before irradiation)

TABLE 4.

Complications of Arthroscopic Synovectomy (Surgery)

Infection with pseudomonas aeruglnosa

early infection 1 case

late infectNon 1 case

Oliguria and general weakness due to hyponatremia

Excessive retention of intraarticular bloody exudate

Muscle weakness in tne operated extremity 3 cases

2 cases

1 case

total 8 cases

resectoscope only two patients showed mild hyponatremia, possibly resulting from the use of Cytal. The condition was transitory in every case, and with adjust-

ARTHROSCOPIC ELECTRIC SYNOVECTOMY 257

34 .F . L t . Knee J.

Figure 5 . The findings of arthrogram and arthroscopy of a case of a 34 year old female with localized nodu- lar synovitis. This case suffered from a thumb-tip sized mobile tumor at medial side of the joint space (shown by arrow) on knee motion for a year. A few episodes of locking and galt disturbance brought her to the hosp.Lal.

ment of serum electrolyte levels in the showed a synovial membrane with transfusion solution there were no addi- changes of rheumatoid arthritis (Figure tional instances. 8A). There was evidence of marked in-

flammation, such as multiple large villi

PATHOLOGIC EXAMINATION OF TISSUES

Most specimens of the synovial membrane obtained by resectoscope were tissue sec- tions with an approximate size of 0.5 by 0.7 by 1 cm, as shown in Figure 4. Macro- scopic examination of the resected syno- vial membrane showed that the resected surface was cut sharply, almost linearly by the loop, with tissue coagulation. The width of tissue coagulation in the resected tissue was approximately 500 to 100 p where coagulation and necrosis had occurred. In four cases joint inflam- mation recurred; the resectoscope was used again in the same manner.

Histologic examination in one case

and lymphocytic follicles. Eleven months after the first operation with the resecto- scope the inflammation recurred and marked retention of synovial fluid in the joint was observed. Therefore, operation was performed again. The surface layer of the synovial membrane showed only slight congestion and hyperplasia and ridgelike protrusion without villi through- out the tissues. Histologic study revealed that most portions of the synovial mem- brane consisted of blood vessels and gra- nulation tissue with predominant fibrosis with which the inflammatory lesion and the accompanying exudate of fibrin-like substance are associated (showing in ar- row Figure 8A). The electric resectoscope therefore caused no obviously harmful effects.

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Figure 6. Resected tumor with electric resectoscope and adjacent synovial membrane of the case in Figure 5.

DISCUSSION

Many surgeons have noted subsidence or relief of pain after conventional synovec- tomy. However, there often is either loss of joint motion or a prolonged recovery period. When changes were observed on X-ray examination, the incidence of re- currence was high, possibly because of a mechanical factor. Thus, many authors believe that synovectomy should be per- formed before roentgenographic changes are seen. However, since chronic rheuma- toid arthritis is a systemic although self- limiting disease, very few authors believe

that synovectomy can arrest the rheuma- tic lesions in all cases. This is the main reason for the difference from the excel- lent results of synovectomy for the cases with chronic synovitis (Hydrops articu- laris genus). Patients with progressive multiple joint lesions that have shown a high level of activity usually show only a brief preiod of improvement following surgery. Even though, many reports (Goldie 197 1, Marmor 1973, Patzakis et a1 1973) indicate improvement in labora- tory findings following synovectomy.

Histologic findings (Goldie 1971 , Mar- mor 1973) in the regenerated synovial

ARTHROSCOPIC ELECTRIC SYNOVECTOMY 259

Figure 7. Histologic findings in synovial membrane, compatible with localized nodular synovitis.

membrane vary. An increase in cicatri- cia1 and connective tissue is reported by some investigators, whereas others state that the synovial membrane appears nor- mal clinically. Resection of the inflamed tissues interrupts the abnormal foci and the progress of the disease may be there- by impeded.

Since he had observed no systemic exacerbation and marked symptomatic relief instead, Paradies (1 969) emphasizes the importance of early synovectomy. Resection of the inflamed tissues seems indicated especially in patients who show early flexion contractures with a hyper- plastic synovium and excessive joint fluid with the popliteal cyst. Symptomatic and functional improvement appears to persist until the regenerated tissues are reinvaded by the inflammatory process, which will occur only in less than one third of the operated cases.

Recently electron microscopic scans of the minute synovial blood vessel pat-

terns have been reported (Kodama & Kondoh 1973). The specimens were pro- duced by the injection of methylmetha- crylate into the femoral artery. Four layers of blood vessels have been noted in the synovium. The vascular connec- tions between the layers appeared to be minimal. The progress of pathologic changes in the area may thus be estimated from the distribution of the vessels in each layer. These findings have suggested that resection of 1 mm layer of syno- vium may suffice in the early rheumatoid joint.

Synovial resection even by convention- al methods is often difficult and, at times, incomplete. The extensive incision that is required often results in a pro- longed convalescence. In spite of the beneficial effects of synovectomy, the patient may postpone or refuse the pro- cedure. The use of the electric resecto- scope was first proposed because of the foregoing problems (Aritomi & Yama-

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Figure 8. Histologic findings in synovial membrane. A: The regenerated membrane with recurrence of the in- flammation (showing with an arrow), 1 1 months after the first operation. B : The findings by synovectomy with the resectoscope at the first operation.

mot0 1979, 1981). The arthroscopic features of the instrument offer a simple method of examination and synovial biopsy. The advantages of this new modality over conventional synovectomy are indicated as follows (Aritomi & Yamamoto 1979, 1981). Because of the small incision and electrocoagulation, postoperative bleeding is minimized. Postoperative pain is also greatly de- creased, recovery of function is greatly accelerated, and hospitalization is short- ened. An added benefit resides in the fact that only one surgeon is needed to perform the operation.

Except for patients with postoperative complications, the average period of hos- pitalization was 10.3 days. Although

some patients with severe radiologic changes again developed joint effusion shortly after operation, their pain was comparatively relieved. When the opera- tion is performed with the electric resec- toscope, it provides the benefit of fewer side effects than the conventional pro- cedure with comparable clinical results.

Although use of the electric resecto- scope has the aforementioned benefits, the operation still has its problems (Table 3). Some of the difficulties reside in the structure of the resectoscope per se and its accessories. Furthermore it is essential that the surgeon acquires ade- quate skill in use of the instrument.

It is believed that with an improved instrument the area of resectable tissue

ARTHROSCOPIC ELECTRIC SYNOVECTOMY 26 1

will be about the same as that now re- moved by the open procedure. currently the available area of resection is increased by use of both the inferomedial and the inferolateral approaches.

In order to identify the tissue to be re- sected more clearly 1 per cent osmic acid with Xylocaine is injected into the joint about two hours prior to surgery. The synovial surface usually turns into a gray- ish hue. Estimation of the area of the tissue to be resected is thereby facilitated.

Postoperative bleeding and infection are not unusual when a conventional synovectomy is performed. The ability to perform electrocoagulation with the resectoscope greatly reduces hemorrhage both during and after the procedure. By use of a sterile hood and administration of antibiotics, postoperative infection has been minimized.

Although reactions to the irrigating fluid have been reported by urologists (Mitchell 1972), no severe reactions have been encountered except for hypo- natremia.

Although other problems such as post- operative quadriceps weakness may oc- cur, they are minimal in duration when the resectoscope is used.

CONCLUSIONS

The electric resectoscope used for trans- urethral resection in urology was modi- fied to perform synovectomy and arthro- scopic surgery in the knee joint.

The advantages and problems of syno- vectomy and arthroscopic surgery with the electric resectoscope as used in the knee joint are discussed, especially in comDarison with conventional resection

of the anterior two-thirds of the synovial membrane. Clinical follow-up observation indicated that synovectomy performed with the electric resectoscope produced the results almost comparable with those of conventional synovectomy.

Arthroscopic surgery is performed through a small skin incision with fewer untoward effects and offers more rapid recovery after operation.

A few complications however, were noted by this method. None were serious except for two episodes of infection dur- ing the early use of this technique.

With the progress of the diagnostic arthroscope, further development of the electric resectoscope is expected to be beneficial not only in making a diagnosis, as in biopsy, but in arthroscopic surgery for joint diseases.

ACKNOWLEDGEMENT

Author acknowledges Prof. T. Koshiba, Urological Department of Kitasato Uni- versity, for his kind advice and help with the electric resectoscope.

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