Arthroscopy: The Journal of Arthroscopic and Related Surgery 9(3):327-331 Published by Raven Press, Ltd. © 1993 Arthroscopy Association of North America

Endoscopic

Technical Note

Extra-Articular Lateral Release

James C. Y. Chow, M.D.

Summary: This article describes a new technique using the currently available endoscopic instrumentation to perform a lateral release of the knee joint. An extra-articular release is performed in an attempt to decrease complications and to produce a less painful postoperative period for the patient. Key Words: Endoscopy--Extra-articular lateral release.

Of all the arthroscopic knee procedures, a lateral release of the retinaculum is rated the most likely to have complications (1). The current arthroscopic technique for lateral release requires the use of an electric cutter to cut through the synovial mem- brane before reaching the lateral retinaculum (2). The most common complication is hemarthrosis,

From the Orthopaedic Clinic of Mt. Vernon, Mt. Vernon, Il- linois.

Address correspondence and reprint requests to Dr. James C. Y. Chow, 413 E. Main Street, Mt. Vernon, IL 62864, U.S.A.

and there are rare reports of thermal injury of the skin (3). Because the synovial membrane carries a rich blood supply and nerve fibers, this not only increases the possibility of hemarthrosis, but cre- ates a lot of postoperative pain from the procedure itself.

Based on this concept, and using less invasive arthroscopic surgery, the lateral retinaculum can be released without cutting through the synovial mem- brane. Twenty cases of release of the lateral reti- naculum have been performed successfully using

FIG. 1. The patient is placed in the supine position, prepared, and draped in the usual manner.

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FIG. 2. The superior medial portal is located about three finger- breadths proximal to the proximal pole of the patella.

FIG. 4. Extension of the knee joint is performed by swinging the leg from the lateral side of the table.

the currently available endoscopic instrumentation. This article is a report of the technique.

OPERATIVE TECHNIQUE

The patient is given a general anesthesia and an uninflated tourniquet is applied to the affected thigh. With the patient in a supine position, and without a knee holder (Fig. 1), the skin is prepared and draped in the usual manner. A routine arthro- scopic evaluation of the knee is performed through the anterior medial and anterior lateral portals.

After routine arthroscopic knee joint examina- tion, an arthroscope is inserted through the superior medial portal. This portal is located about three fin- gerbreadths proximal to the proximal pole of the patella (Fig. 2) (4). The scope will enter the superior

patellar pouch and the knee can then be examined from above. A specially designed scope is helpful because its light post comes from the same direction as the 30 ° arthroscope and is not hitting the thigh. Flexion and extension of the knee joint is performed by swinging the leg from the lateral side of the table (Figs. 3 and 4). Evaluation of the patella gliding and its relationship with the femoral condyle is made from the superior medial portal.

A skin marker is used to mark the outside of the joint. The most desirable positions for the lateral release are usually located ~ 1 cm from the lateral border of the patella (Fig. 5). When the knee joint is in the 30-45 ° flexion position, it is interesting to note that the curved line made by the marker be- comes straight (Fig. 6). The lateral portal should be made on the distal end of this line.

With the knee joint in a flexed position and using

FIG. 3. Flexion of the knee joint is performed by swinging the leg from the lateral side of the table.

FIG. 5. Skin marker is used to mark the outside of the joint, - 1 cm from the lateral border of the patella.

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EXTRA-AR TICULAR LATERAL RELEASE 329

FIG. 6. The curved line made by the marker becomes straight when the knee is in the 30--45 ° flexion position.

FIG. 8. The second portal is made proximally at the end of the marked guide line.

the endoscopic carpal ligament release holder, the deeply sloped side faces proximally and the slightly sloped side faces distally as a knee rest (Fig. 7). With the scope in the superior medial portal, the slotted cannula trocar assembly is inserted into the joint through the anterior lateral portal. The tip of trocar is then directed laterally and proximally, fol- lowing the line drawn on the outside of the knee joint, wiggling around outside of the synovial mem- brane just beneath the lateral retinaculum. Control of this maneuver is possible with constant visual- ization through the arthroscope in the knee. The slotted cannula is then gently passed proximally, using great caution to avoid puncturing the syn- ovium. This is sometimes difficult because of pres- sure from the lateral retinaculum.

The slotted cannula°assembly must pass between the synovium and the lateral retinaculum. When the entire assembly has passed underneath the lateral

FIG. 9. The trocar is then removed from the slotted cannula.

FIG. 7. The endoscopic carpal ligament release holder is used as a knee rest with the deeply sloped side facing proximally and the slightly sloped side facing distally. FIG. 10. A short endoscope is brought in.

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FIG. 11. The three knives designed for endoscopic release of the carpal ligament will be used to release this transverse lateral retinaculum.

retinaculum, the second portal is made proximally at the end of the marked guide line as the trocar assembly passes through the exit portal of the skin (Fig. 8). The trocar is then removed from the slotted cannula and a short endoscope is brought in (Figs. 9 and 10). The camera view is switched from the in- tra-articular view to the endoscopic view. Fibers that run at angles to the slotted cannula can be iden- tiffed as the lateral retinaculum. The three knives that were designed for endoscopic release of the carpal ligament will be used to release this trans- verse lateral retinaculum (Fig. 11).

Because the tourniquet on the thigh is not in- flated, bleeders, and in some cases the vessels themselves, can be seen. If there happens to be a slight bleeder it can be coagulated by sliding a plas- tic protected electrocoagulator through the slotted cannula.

After the retinaculum has been released com- pletely through endoscopic control, the open slot- ted cannula is turned 180 ° so that it is facing the knee joint (Fig. 12). This double inspection ensures that no lateral retinacular tissue has been punctured during the slotted cannula insertion and that a com- plete release has been obtained.

After the surgeon is satisfied with the lateral ret- inaculum extra-articular release, the slotted cannula and the tubes are removed from the knee joint. A combined examination and arthroscopic evaluation of the patella tracking is performed to assist the surgeon in determining that an adequate release was accomplished. In the examination, 90 ° eversion of the patella with the articular surface laterally can be easily accomplished to indicate adequacy of the lat- eral release (5-7). The arthroscope is then switched back to the knee joint on the superior medial portal, and an evaluation of the patella gliding is performed arthroscopically. If additional medial reefing is re- quired, it can also be performed at this time. The joint is then irrigated with saline and the instrumen- tation is removed. The arthroscopic and endoscopic portals are closed in the usual manner.

POSTOPERATIVE COURSE

A simple dressing is applied, and active move- ment is encouraged. Exercise to build up the quad- riceps and an active range of motion as tolerated are started right after surgery. The patient is given a 1-week follow up appointment for suture removal. At this time, the majority of patients had little post- operative pain and had gained back knee joint mo- tion in 1 week to 10 days.

FIG. 12. The open slotted cannula is turned 180 ° so that it is facing the knee joint.

DISCUSSION

This is an early and preliminary report describing a new technique. The author will follow up at a later date with a complete report and an analysis of ac- cumulated data based on more case histories and a longer follow-up period.

REFERENCES

1. Small NC. An analysis of complications in lateral retinacular release procedures. Arthroscopy 1989;5:282-6.

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EXTRA-ARTICULAR LATERAL RELEASE 331

2. Metcalf RW. An arthroscopic method for lateral release of the subluxating or dislocating patella. Clin Orthop Rel Res 1982;167:9-18.

3. Lord MJ, Maltry JA, Lawrence SM. Thermal injury result- ing from arthroscopic lateral retinacular release by electro- cautery: report of three cases and a review of the literature. Arthroscopy 1991 ;7:33-7.

4. Merchant AC, Mercer RL. Lateral release of the patella. Clin Orthop Rel Res 1974;103:40.

5. Ficat PR, Hungerford DS. In: Picket, Justus, Radin EL, eds. Disorders of the patellofemoral joint. Baltimore, MD: Williams & Wilkins, 1977:120.

6. Merchant AC. Patellofemoral disorders: biomechanics, di- agnosis, and nonoperative treatment. In: McGinty JB, ed. Operative arthroscopy. New York: Raven, 1991:261-75.

7. Ewing JW. Arthroscopic patellar shaving and lateral reti- nacular release. In: McGinty JB, ed. Operative Arthros- copy, New York, Raven Press, 1991:277-84.

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