360 ABSTRACTS

Materials and Methods: All pathologic materials were obtained at the time of surgical lysis and re- section of arthrofibrosis. All specimens were retro- spectively reviewed in a qualtitative and quantita- tive fashion by a musculoskeletal pathologist. He- motoxylin and eosin stains were used for all specimens. The pathologic characteristics were then attempted to be correlated with patient sex, age, postoperative reconstruction motion protocol, time interval from reconstruction to resection of ar- throfibrosis, and gross pathologic variant (global vs. localized anterior intraarticular variant).

Results: A total of 20 patients (14 male and 6 fe- male) underwent surgical resection of arthrofibrosis after central third patellar tendon ACL reconstruc- tion. The total number of specimens was 22 (two patients underwent a second procedure). Several pathologic characteristics were identified and quan- titated. The pathologic findings included synovial chondrometaplasia (22 of 22), vasicular prolifera- tion (22 of 22), fibrosis (22 of 22), foreign materials (17 of 22), synovial proliferation (16 of 22), hemo- siderin (16 of 22), inflammation (16 of 22), fibrin (11 of 22), and endochondral ossification (two of 22). The average patient age was 23.9 years (range 16- 34). The average time to resection of arthrofibrosis was 8.95 months (range 3-2I). There was a trend toward maturity of synovial chrondrometaplasia as this interval lengthened; however, no statistical sig- nificance was found. Gross pathologic appearance at the time of resection demonstrated 15 global ar- throfibrotics versus seven localized anterior intraar- ticular variants. The basic histopathologic changes found in all of these patients were the same. There was no difference in the incidence of vascular pro- liferation, fibrosis, or synovial chrondrometaplasia regardless of the gross appearance (i.e., global vs. localized anterior intraarticular variants). Motion protocols for patients reconstructed at our institu- tion were twofold. Thirteen patients were mobilized in a range-of-motion brace, preventing passive ex- tension from 45 ° of flexion for 2 weeks. Four pa- tients were splinted at 45 ° of flexion, preventing passive extension for 48 h. The remaining patients were reconstructed at an outside institution, and details to the postoperative protocol are lacking. There was no apparent change in the histopathology of arthrofibrosis regardless of which postoperative motion protocol was used.

Conclusions: Arthrofibrosis as a term is a misno- mer. Histopathologic study documents the frequent presence of vascular proliferation and synovial

chondrometaplasia in addition to fibrosis. Chon- drometaplasia exhibited a trend toward maturity and even bone formation as the interval from sur- gical reconstruction to surgical resection of arthrofi- brosis lengthened. Immobilization and failure to be- gin immediate extension postoperatively after ACL reconstruction has been demonstrated to correlate with the occurrence of arthrofibrosis but not with its exact histopathology. The gross pathologic pro- cesses of global versus localized anterior intraartic- ular arthrofibrosis have now been documented to be the same histopathologic process.

An Analysis of the Effects of Suture Technique on the Vascular Supply of the Medial Meniscus. Wayne J. Sebastianelli, David G. Hicks, H. Brooks, Kenneth E. DeHaven, and H. Wong. Rochester, New York, U.S.A.

Purpose:. To histologically study the vascular anatomy of the medial meniscus after scope- assisted (inside-out technique) versus open repair of a surgically created posterior peripheral meniscus lesion.

Conclusion: Microscopic study indicates that open meniscus repair is more disruptive to the mi- crovasculature of the medial meniscus than is the scope-assisted inside-out repair technique.

Significance: Suture technique can increase the amount of tissue ischemia, thereby delaying healing time of the meniscus.

Summary of Method, Results, and Discussion: Us- ing fresh frozen cadaver lower extremities, poste- rior medial meniscal lesions were surgically cre- ated. The specimen was first secured in a vice clamp attached to the femur, allowing the knee to flex 90 ° unsupported. An arthrotomy using a lateral parapatellar incision was then made, allowing expo- sure of the medial femoral condyle. The medial fem- oral condyle was then excised, exposing the entire medial meniscus. A 1.5-cm posterior peripheral red- red lesion was then surgically created. This was then followed by meniscal repair (scope-assisted vs. open). India ink (120 ml) was injected into the spec- imen via the cannulated superficial femoral artery. After a setting time of 20 rain, the entire medial menisco-capsular junction and medial meniscus was harvested. Fixation in formalin was followed by hematoxylin and eosin staining. The menisci were then studied by light microscopy at 200x for the presence of India ink within vessel lumens. Ink- filled vessels versus empty (ischemic) vessels were

Arthroscopy, Vol. 9, No. 3, 1993

ABSTRACTS 361

counted and plotted as a function of distance along the meniscus.

Microscopic study indicated that open meniscus repair is more disruptive to the microvasculature of the medial meniscus than is the scope-assisted in- side-out repair technique.

Suture technique can increase the amount of tis- sue ischemia, thereby delaying healing time of the meniscus. As a result, surgeons should be aware of their repair technique and adjust their postoperative protocols accordingly. Furthermore, accelerated return to sport in patients with isolated meniscus repair or repair with anterior cruciate ligament re- construction must be studied further in light of this data.

Meniscal Allotransplantation: An Arthroscopically Assisted Technique. Walter R. Shelton. Jackson, Mississippi, U.S.A.

Human meniscal allotransplantation is a new and promising procedure. Heretofore the procedure has required an extensive arthrotomy with direct suture implantation. Ten consecutive patients with chronic meniscal deficiency were managed by a new surgi- cal technique using an arthroscopic approach to im- plant the allograft meniscus with attached bone plugs. Before the initial procedure, extensive re- view and participation in the open implantation technique, along with cadaveric refinement of the proposed arthroscopic technique, were accom- plished. Ten menisci using this new arthroscopic technique were implanted over a 10-month period. The presented technique includes preparation of the meniscus with attached bone plugs, preparation of the peripheral rim bed, drilling of tibial tunnels for bone plug placement, passage of the meniscus and bone plugs into the recipient site without detach- ment of collateral ligaments, securing the bone plugs in the appropriate bony tunnel, and peripheral suturing of the implanted meniscus. All 10 patients were treated as 23-h outpatients, and there were no short-term complications associated with this tech- nique. To date all 10 menisci show evidence of in- corporation of the bone plugs and peripheral heal- ing. Two patients with grade III and IV articular changes had repeat arthroscopy 6 months postsur- gery, with both showing posterior horn erosion of the new meniscus and requiring partial meniscecto- my. Average operative time for the 10 procedures was 2 h 8 min. With the majority of patients now at <1 year postsurgery, no meaningful data can be

derived regarding long-term function or viability of the menisci. The presentation does present an ar- throscopic technique of implantation of an allograft meniscus as opposed to an extensive arthrotomy.

Meniscal Salvage with Local Allograft. J. Kevin Lynch and Mark Shepard. New Haven and East Haven, Connecticut, U.S.A.

Objectives: Although meniscal repair is intellectu- ally accepted, many meniscectomies are still com- monly performed. This is particularly true in tears that are horizontally oriented. The objective of this study was to evaluate the feasibility of salvaging mensci with significant horizontal tears by using lo- cal allograft, endogenous fibrin, and suturing.

Materials and Methods: Eighteen patients with horizontal meniscal tears underwent arthroscopy. Those associated with lateral meniscal cysts under- went cyst excision, and all tears were grafted using local allograft, fibrin, clot, and suturing. The knees were immobilized for three weeks and the patients were kept non weight bearing. Rehabilitation and graduated weight bearing occurred thereafter.

Eighteen patients were followed for an average of 2.9 years. Ten involved lateral meniscal tears in conjunction with lateral meniscal cyst and eight were medial meniscal tears.

Results: All patients returned to normal functional levels with improvement of their knee scores and maintenance of joint height on standing radio- graphs. Several patients underwent second-look ar- throscopy.

Conclusion: Local meniscal allografting is a feasi- ble procedure.

Significance of Findings: Selected complex, hori- zontally oriented meniscal tears can be repaired without resorting to meniscectomy.

Anterior Cruciate Ligament Reconstruction: Endo- scopic Versus Two-Incision Technique. Christopher D. Harner, Mark B. Silbey, Richard Mengato, and Freddie H. Fu. Pittsburgh, Pennsylvania, U.S.A.

A prospective study of 60 patients (63 knees) was conducted in order to compare the less invasive sin- gle-incision "endoscopic" anterior cruciate liga- ment (ACL) reconstruction technique with the tra- ditional two-incision " r e a r - e n t r y " technique. Thirty-one consecutive knees underwent a two- incision technique (group A), then 32 consecutive knees were reconstructed with the single-incision technique (group B). All patients followed a stan-

Arthroscopy, Vol. 9, No. 3, 1993