Clinical, Functional, and Radiographic Assessment of Arthroscopic Abrasion Chondroplasty of the Knee

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1 Journal of Sport Rehabilitation, 1996,5, O 1996 Human Kinetics Publishers, Inc. Clinical, Functional, and Radiographic Assessment of Arthroscopic Abrasion Chondroplasty of the Knee Michael Ra, Michael Sitler, Jeff Ryan, Raymond Moyer, Paul Marchetto, John Kelly, and Iris Kimura Chondral lesions often occur in the knee as isolated defects or part of more complex injuries. Articular cartilage defects decrease the ability of the knee to sustain weight-bearing loads and may accelerate degeneration of the joint when left untreated. The purpose of this study was to determine the clinical, functional, and radiographic outcome of arthroscopic abrasion chondroplasty of the knee. The Articular Cartilage Rating System was used to assess the location, size, depth, and description of the articular lesion. The Standard Knee Evaluation Fonn and Cincinnati Knee Rating Scale were used to assess the clinical, functional, and radiographic outcome of the procedure. Average time to post follow-up was months. Within the constraints of the present study, arthroscopic abrasion chondroplasty of the knee had a favorable clinical, functional, and radiographic outcome. However, more study is needed with larger samples and longer follow-up before definitive conclusions about the efficacy of the procedure can be made. Hyaline, or articular, cartilage is an essential component of the articular surfaces of diarthrodial joints. The viscoelastic properties of hyaline cartilage facilitate dispersion of compressive forces during static and dynamic joint loading. Injury to articular cartilage, or chondral lesions, can occur as a result of disruption of normal joint movement. Joint instability, uneven articular surfaces, osteochondritis dissecans, subchondral bone fractures, and congenital and acquired malalignment (varus or valgus) are also associated with chondral lesion formation (1 I). Injury to articular cartilage of the knee can occur when the fibrocartilaginous meniscus is tom (21). This is attributed to a decreased force absorption capability of the torn meniscus. With an unstable meniscal tear, the axis of motion of the knee is altered, producing abnormal compression and shear forces on the articular cartilage (1 3). The knee is the most common site of chondral lesions in humans (5). Com- M. Ra, M. Sitler, and I. Kimura are with the Department of Physical Education, Temple University, Philadelphia, PA J. Ryan, R. Moyer, P. Marchetto, and J. Kelly are with the Department of Orthopaedics and Sports Medicine, Temple University Hospital, Philadelphia, PA

2 128 Ra, Sitler, Ryan, eta/. mon knee chondral lesion sites are the medial and lateral femoral condyles and the patella (4,9, 13,19). The incidence of chondral lesions is four times greater for the medial femoral condyle than the lateral femoral condyle (4), and the majority of lesions occur over weight-bearing surfaces (13). Surgical treatment of knee chondral lesions is indicated when joint function is compromised by pain, restricted motion, or internal derangement (20). The goals of surgical treatment include relieving pain, improving and maintaining joint movement, correcting deformity and malalignment, and removing intra-articular irritants (15). Arthroscopic abrasion chondroplasty of the knee has been performed for the last 15 years. The procedure consists of using a motorized burr to abrade the lesion to a depth of 1-2 mm to subchondral intracortical bone. The purpose of the procedure is to remove dead bone and expose a vascular tissue bed for blood clot formation (1 2). The organizing hematoma formation then differentiates into fibrocartilage. Early results of knee abrasion chondroplasty were first reported in the 1980s. Friedman et al. (7) reported that 60%, 34%, and 6% of the arthroscopic abrasion chondroplasty patients in their study improved, were unchanged, or deteriorated post, respectively. Bert and Maschka (2) reported on a 5-year follow-up study comparing arthroscopic abrasion chondroplasty of the knee to arthroscopic debridement of the knee. Fifty-nine patients had both arthroscopic abrasion chondroplasty and arthroscopic debridement, and 67 patients had arthroscopic debridement only. Of the group treated with abrasion chondroplasty and debridement, 5 1% had good to excellent results, 16% had fair results, and 33% had poor results. Of the group treated with debridement only, 66% had excellent results, 13% had fair results, and 21 % had poor results. Arthroscopic abrasion chondroplasty of the knee has been performed by Temple University Center for Sports Medicine orthopedic surgeons since The purpose of this investigation was to evaluate the clinical, functional, and radiographic outcome of arthroscopic abrasion chondroplasty of the knee joint. Subjects Methodology The study population consisted of 44 patients who had undergone arthroscopic abrasion chondroplasty at the Temple University Center for Sports Medicine between 1985 and Patients with anterior cruciate, posterior cruciate, medial collateral, or lateral collateral ligament injury or prior knee were excluded from the study. Eighteen (41 %) of the original 44 patients agreed to participate in the followup study: 12 (66.7%) males and 6 (33.3%) females. Patient attrition was due to a lack of current address and phone number information. Subjects' average age was years. Mean time from to study follow-up was months. All subjects read and signed an informed consent in accordance with the Temple University Institutional Review Board prior to study participation. Pre- and Postoperative Treatment Regimen Preoperatively, patients were allowed to bear weight as tolerated. Rehabilitation consisted of active and active-assisted range of motion (ROM) exercises as needed. Straight leg raise and open kinetic chain progressive resistive exercises were per-

3 Arthroscopic Abrasion Chondroplasty 129 formed for the quadriceps and hamstrings through a pain-free range of motion. Ice was used to control pain and swelling. Postoperatively, patients with a femoral condyle lesion that made contact on the tibia from 0 to 45" of motion were not allowed to bear weight for 8 weeks but completed appropriate motion exercises. Motion exercises consisted of mechanically assisted continuous passive motion, active-assisted and passive range of motion exercises, stationary bicycling, andlor aquatic exercises. Patients with a lesion in the femoral contact area 45" or greater performed the same range of motion exercise as the aforementioned patients and were allowed to bear weight as tolerated. All patients conlpleted a postoperative strengthening program of straight leg raises, open kinetic chain exercises through a pain-free arc of motion, and closed kinetic chain exercises. Closed kinetic chain exercises were begun when the patient was at least 50% weight-bearing on the affected leg. These exercises were performed in a range such that weight was not applied on the lesion. Ice was used to control pain and swelling. Data Collection InStruments Subjects were evaluated with respect to grade of articular lesion via the Articular Cartilage Rating System (ACRS) (17), clinical outcome via the Standard Knee Evaluation Form (SKEF)(14), and functional activity level via the Cincinnati Knee Rating System (CKRS)(16). The ACRS, as developed by Noyes and Stabler (l7), was modified to meet the research objectives of the present study. Preoperative lower extremity alignment (varus and valgus) and x-ray (joint space distance and osteophyte formation) information was not prospectively assessed and available for analysis. ACRS. The ACRS (Table 1) (17) consisted of four variables: description, depth, size, and location of the lesion. This information was assessed during the arthroscopic procedure and recorded in the postoperative notes. Chondral lesion information was therefore obtained from each subject's postoperative report. Appearance and depth of the lesion were described as chondromalacia, open lesion, or bone. Size of the lesion was based on the number of degrees of articulation in the ROM. Small lesions articulated less than 30, medium lesions articulated from 30 to 60, and large lesions articulated greater than 60" in the range of motion. Articular location of the lesion was categorized as patella, femoral sulcus, medial femur, medial tibia, lateral femur, or lateral tibia. Each of these six articular sites was assessed for grade', description, and size of the lesion, based on a 0 to 10 scale. A compartmental score (patellofemoral, medial, and lateral) was determined by summing the scores for the two sites within the same compartment. A percentage was then calculated by subtracting the compartment score from 20 and then dividing the difference by 20 and multiplying by 100 (17). A composite instrument score was obtained by averaging the three compartment percentages. The lower the composite ARC score, the larger the chondral lesion. SKEl? The SKEF (Figure 1) (14) consisted of three components: patient information, functional assessment, and clinical assessment. A composite SKEF score was established for each subject based on the group grade for each of six clinical variables: patient subjective assessment, symptoms, ROM, ligament examination, compartme'nt findings, and radiographic findings. The lowest grade for each variable comprised the group grade for that variable. The grading scale was

4 Ra, Sifler, Ryan, et a/. Table 1 Articular Cartilage Rating System Grade description 1. Chondromalacia A. Soft B. Softening, definite indentation 2. Open lesion A. Fissures1 fragment 112 thickness B. Fissures1 fragment full thickness 3. Base A. Base exposed B. Base cavity Lesion Compartment points Anatomical score Average of S M L Part Score % percentages Patella Femoral sulcus Medial femur Medial tibia Lateral femur - - Lateral tibia Note. To evaluate percentage: (20 - score of compartment) x organized according to the following hierarchical scale: normal, nearly normal, abnormal, and severely abnormal. Bilateral x-rays were taken to assess the tibiofemoral and patellofdmoral joints. The Merchant view (45" knee flexion) was used to assess the patellofeinoral articular surfaces. Bilateral anteroposterior weight-bearing x-rays (30 to 45" knee flexion) were used to determine the extent of medial and lateral joint space narrowing. A grade of normal consisted of minimal changes and a joint space width greater than 4 mm. A grade of nearly normal consisted of joint space narrowing from 2 to 4 mm. A grade of abnormal consisted of a joint space width less than 2 rnm. CKRS. The CKRS (Figure 2) (16) was based on a 100-point scale and consisted of two parts. Pain, swelling, and instability were graded in Part I, the symptom category. Points were awarded based on the activity level at which they occurred. The functional activity level of the subject was determined in Part 11, the function category. In Part 11, overall activity level, walking, stair climbing, running activities, and jumping or twisting activities were assessed, based upon the subject's perception of pain during these activities. Data Collection and Analysis The subjective sections of the SKEF and CKRS were completed by each subject during an initial office visit. Clinical examinations were conducted by one of three board-certified Temple University orthopedic surgeons. X-rays were taken by a

5 Arthroscopic Abrasion Chondroplasty 131 Patient Name Date I I Home Address Town State Zip Age - Sex Height Weight Sport: 1st choice 2nd choice Involved knee: 0 Right 0 Left Contralateral normal? 0 yes 0 no Cause of injury: 0 ADL Date of injury: Post-op diagnosis: 0 Traffic Date of index operation: I I 0 Contact sport 0 Noncontact sport Previous Surgery Arthroscopy: Date (1)- (2)- (3)- Meniscectomy Dx: - Stabilization procedure: I. Strenuous activity: jumping, pivoting, hard cutting (football, soccer) II. Moderate activity: heavy manual work (skiing, tennis) Activity Preinjury Re-Rx Post-Rx III. Light activity (jogging, running) rv. Sedentary activity (housework, ADL) Figure 1 - Standard Knee Evaluation Form.

6 132 Ra, Sitler, Ryan, et a/. Clinical Assessment Seven groups Four grades Group grade 5. Patient Subjective Assessment -How does your knee function? --On a scale of 0-3, how does your knee affect activity level? 2. Symptoms (Grade at highest activity level with no significant symptoms) Exclude 0 to slight symptoms) -Pain -Swelling -Partial giving way -Full giving way B D A Nearly C Severely Normal Normal Abnormal Abnormal A B C D R u 0 u R R U U R U 0 U I I1 111 IV 0 u u u 0 U 0 U 0 U R R R 3. Range of motion ExtFlex: Index side Opposite side -Lack -Lack of extension of flexion 4. Ligament Examination (manual, instrument, x-ray) -Lachman (25 flexion) -Endpoint: firrnlsoft -Total Am trans. 70 flex -Post. sag 70 -Valgus 20 -Vms 20 -Pivot shift -Reversed pivot shift 5. Compartment Findings -<repitus patellofemoral -<repitus medial compart. -<repitis lateral compart. 6. X-Ray Findings -Med joint space narrowin, g -Lat joint space narrowing : -PatFern joint narrowing Final examination mm U 3-5 mm mm R >lo mm -1-3 stiff <-3 stiff R firm 0 soft R 1-2 mm R 3-5 mm mm R >I0 mm 0 1-2mm 03-5mm 06-10mm R>lOmm R 1-2 mm U 3-5 mrn R 6-10 mm U >lo rnm U 1-2mm U3-5mm CI6-lOmm U>lOrnrn Rneg R equal R glide R marked U gross U R none O minimal R moderate 0 severe R none U minimal R moderate R severe U none R minimal 13 moderate R severe R R R 0 13 none 0~25% R<50% R >50% R none R <25% R<50% R >50% R none R <25% R <50% R >50% O 0 U U Figure 1 - continued.

7 Arthroscopic Abrasion Chondroplasty 133 During the last several months prior to: Initial Follow-up after initial Final Follow-up after final Part I: Symptom Category Pain (0) Pain is present all the time, occurs with walking and standing and at night. Not relieved with rest. (4) Pain is significant problem with activities as simple as walking but is relieved by rest. Prevents doing sports. (8) Pain is usually brought on by sports, light recreational activities, or moderate work, but only occasionally occurs with walking, standing, or light work. (12) Occasional pain with light recreational sports or moderate work activities, but frequently brought on by vigorous activities, running, heavy labor, strenuous sports. (16) Occasional pain with strenuous sports or heavy work; knee not entirely normal; some limitations but minor and tolerable. (20) No pain, normal knee, even with strenuous (running, cutting, jumping) sports. (999) I have no pain but have not tested my knee in strenuous sports to know if pain would be present. Swelling (0) A severe problem all of the time, always occurs with simple walking activities. (2) Swelling often brought on by simple walking activities and light work. Relieved with rest. (4) Swelling limits sports and moderate work but occurs only infrequently with simple walking activities or light work (about three timeslyear). (6) Occasional swelling with light recreational sports or moderate work activities, but frequently brought on by vigorous activities, running, heavy labor, strenuous sports. (8) Only occasional swelling with strenuous sports or heavy work. Some limitations but minor and tolerable. Figure 2 - Cincinnati Knee Rating System.

8 134 Ra, Sitler, Ryan, et a/. During the last several months prior to: Initial Follow-up after initial Final Follow-up after final (10) No swelling, normal knee, even with strenuous (running, cutting, jumping) sports. (999) I have no swelling but have not tested my knee in strenuous sports to know if swelling would occur. Instability (Giving Way) (0) A reverse problem even with simple walking activities. Cannot turn or twist while walking without giving way. (4) Giving way occasionally with simple walking activities and light work. Occurs approximately once per month. Requires guarding. (8) Giving way does limit sports and moderate work but occurs infrequently with walking or light work (about three timeslyear). (12) Occasional giving way with light recreational activities or moderate work, but able to compensate. Limits vigorous activities and sports or heavy work. Not able to cut or twist suddenly. (16) Occasional giving way with strenuous sports or heavy work. Can participate in all sports but some guarding or limitation is still present. (20) No giving way; normal knee, even during strenuous (running, cutting, jumping) sports. (999) I have no knee instability but have not tested my knee in strenuous sports to know if it would give way. Total Scores (999 if any subscore = 999) *Enter 999 if was done acutely following : i.e., if patient has no basis for judging pre-operative chronic symptoms or functional disability **If afinal surgical procedure was also done, use last several months prior to this procedure at the time-period of evaluation. Figure 2 - continued.

9 Arthroscopic Abrasion Chondroplasty 1 35 During the last several months prior to: Initial Follow-up after initial Final Follow-up after final Part 11: Function Category Overall Activity Level (20) No limitation, normal knee, able to do everything including strenuous sports or heavy labor. (16) Perform sports including vigorous activities, but at a lower performance level; involves guarding or some limits to heavy labor. (12) Light recreational activities possible with rare symptoms; more strenuous activities cause problems. Active but in different sports limited to moderate work. (8) No sports or recreational activities possible. Walking activities possible with rare symptoms, limited to light work. (4) Walking, activities of daily living cause moderate symptoms, frequent limitations. (0) Walking, activities of daily living cause severe problems, persistent symptoms. (999) I do not know what my real activity level could be. I have not tested my knee or I have given up strenuous sports for reasons unrelated to my knee. Walking (10) Normal, unlimited. (8) Slight/mild problem. (6) Moderate problem: Smooth surface possible up to + mile. (4) Severe problem: Only two to three blocks possible. (2) Severe problem: Requires cane, cmtchbs. Stairs (10) Normal, unlimited. (8) Slight/mild problem. (6) Moderate problem: Run half-speed. (4) Severe problem: Requires bannister, sdpport. (2) Severe problem: Only one to five steps possible. Figure 2 - continued.

10 136 Ra, Sitler, Ryan, eta/. During the last several mouths prior to: Initial Follow-up after initial Final Follow-up after final Running activity (5) Normal, unlimited, fully competitive, strenuous. (4) Slighdmild problem: Run half-speed. (3) Moderate problem: Only 1 to 2 miles possible. (2) Severe problem: Only 1 to 2 blocks possible. (1) Severe problem: Only a few steps possible. Jumping or Twisting (CuttinglPivoting) Activities (5) Normal, unlimited, fully competitive, strenuous. (4) Slighdmild problem: Some guarding, but sports possible. (3) Moderate problem: Gave up strenuous sports; recreational sports. (2) Severe problem: Affects all sports, must constantly guard. (1) Severe problem: Only light activity possible (golf, swimming). Total Scores (999 if any subscore = 999) Figure 2 - continued. Temple University x-ray technologist. Results of all tests were reviewed with each subject and entered into a computer database for analysis. Data were analyzed using descriptive and inferential statistics. Fisher Exact Probability and ETA coefficient test statistics were used to determine if significant associations existed between selected qualitative variables. Analysis of variance (ANOVA) was used to determine if significant differences existed among selected independent variables. Significant differences were followed up with Tukey's post hoc analysis to determine where the differences existed. Data were analyzed using the SPSS/PC+ 4.0 Release statistical package (18). All statistical analyses were completed in the null form, and the.05 level of probability was considered significant. ACRS Outcome Results The average ACRS score was % (range 67 to 96). ACRS scores by chondral lesion size were as follows (Table 2): small lesions = 83.2%, medium

11 Arthroscopic Abrasion Chondroplasty 137 lesions = 11.1%, and large lesions = 5.5%. ACRS score by knee compartment was also assessed (Table 3). The mean ACRS scores for the medial, lateral, and patellofemoral compartments were 81.7 f 24.4, 87.4 f 20.1, and 86.8 f 14.5, respectively. SKEF Outcome Ten (55.6%) subjects had a SKEF classification of nearly normal (Table 4). Eight (44.4%) subjects had a SKEF classification of abnormal or severely abnormal. No subject had a normal SKEF classification. Univariate analysis revealed that time to follow-up and SKEF outcome were independent (ETA =.40, p =.26). In other words, SKEF outcome was not influenced by the length of post follow-up. Table 2 ACRS Scores (%) by Chondral Lesion Size Chondral lesion size Mean ACRS score Subjects Small Medium Large Table 3 ACRS Scores (%) by Knee Compartment ACRS score Compartment M SD Medial Lateral Patellofemoral Table 4 SKEF Classification Classification Percentage Number Normal - 0 Nearly normal Abnormal Severely abnormal

12 138 Ra, Sitler, Ryan, et a/. All of the subjects submitted to x-ray examination. Fifteen (83.3%) subjects had normal or nearly normal medial joint spaces. Three (16.7%) subjects had abnormal joint spacing of the medial compartment. Seventeen subjects (94.5%) had normal or nearly normal joint spacing of the lateral compartment. One (5.6%) subject had abnormal joint spacing of the lateral compartment. Sixteen (88.9%) subjects had normal or nearly normal joint spacing of the patellofemoral compartment, and 2 (11.1%) subjects had abnormal joint spacing of the patellofemoral compartment. Fourteen (77.7%) of the subjects had associated meniscal pathology. Of these subjects, 9 (50.0%) had subtotal meniscectomies of the medial meniscus, 2 (1 1.1%) had subtotal meniscectomies of the lateral meniscus, and 3 (16.6%) had subtotal meniscectomies of both the medial and lateral menisci. Meniscal injury and SKEF outcome were independently related based on the Fisher Exact Probability test statistic. Although the a priori alpha level for statistical significance was not met, it was relatively low (p =.06). Preinjury and post activity levels were assessed for all subjects (Table 5). For data analysis, activity was stratified into two levels: Strenuous and moderate were grouped together, and light and sedentary were grouped together. Preinjury, 16 (88.9%) subjects participated in moderate or strenuous activities, and 2 (1 1.1%) subjects participated in light activities. Postsurgically, 13 (72.2%) and 5 (27.7%) of the subjects were able to return to moderate or strenuous activities and light or sedentary activities, respectively. Based on the Fisher Exact Probability Test, preinjury and post activity levels were independently related (p = 23). Univariate analysis revealed a significant difference, F(2,5) = 5.45, p =.01, in ACRS score by SKEF outcome (Table 6). Post hoc analysis revealed that the mean ACRS score for SKEF nearly normal (ACRS score = ) was significantly higher than for SKEF abnormal (ACRS score = 79.3 f 9.7) and severely abnormal (ACRS score = ). Table 5 Preinjury and Post Activity Level Activity level Percentage Number Preinjury Strenuous Moderate Light Sedentary Postsurgical Strenuous Moderate Light Sedentary Note. Fisher Exact Probability =.83.

13 Arthroscopic Abrasion Chondroplasty 139 Table 6 ACRS Scores (%) by SKEF Outcome ACRS score SKEF classification M SD Nearly normal 90.6" 4.4 Abnormal Severely abnormal "ACRS score for SKEF nearly normal was significantly different than abnormal and severely abnormal. ANOVA = F(2, 15) = 5.45, p =.01. Table 7 CKRS Scores CKRS score Percentage Number Table 8 ACRS Scores (%) by SKEF Outcome SKEF classification ACRS score M SD Nearly normal Abnormal Severely abnormal "ACRS score for SKEF nearly normal was significantly different than abnormal and severely abnormal. ANOVA = F(2,5) = 3.67, p =.05.

14 CKRS Outcome Ra, Sitfer, Ryan, eta/. The average CKRS score was (range 29 to 93) (Table 7). Six (33.3%) subjects reported a score of 80 or higher, and 6 (33.3%) subjects reported a score of 70 to 79. Six (33.3%) subjects reported a score below 70. Univariate analysis revealed a significant difference in CKRS score by SKEF outcome, F(2,5) = 3.67, p =.05 (Table 8). Post hoc analysis revealed that the mean CKRS score for SKEF nearly normal (CKRS score = ) was significantly higher than for SKEF abnormal (CKRS score = ) and severely abnormal (CKRS score = ). No significant differences, F(2, 15) = , p = 30, existed in time to follow-up and CKRS score. For data analysis, time was stratified as follows: Group 1 = less than 2 years (CKRS mean = ), Group 2 = 2 to 4 years (CKRS mean = ), and Group 3 = greater than 4 years ( ). Discussion Chondral lesions often occur in the knee as isolated defects or as part of a more complex injury to the menisci and/or the anterior cruciate ligament. Articular cartilage defects decrease the ability of the knee to sustain weight-bearing loads. If left untreated, the knee may be prone to accelerated degeneration, along with subsequent pain and inflammation. Abrasion chondroplasty has been used for the last 15 years to treat chondral lesions of the knee. Systems used to classify chondral lesions of the knee are quite varied. Goodfellow, Hungerford, and Woods (a), Ficat and Hungerford (6), and Cascells (3) described the surface appearance of the articular cartilage and depth of the lesion in their chondral lesion classifications. Insall, Falvo, and Wise (10) described the location and surface appearance of the articular lesion but not its depth. Bentley and Dowd (1) differentiated the gradation of chondral injury (Grades I, 11, and 111) based on the diameter of the lesion while describing all three grades as "fibrillation" or "fissuring." Outerbridge (19) included a fourth category in his classification system. He described Grade I as softening and swelling, Grades I1 and I11 as fragmentation and fissuring, and Grade IV as erosion of cartilage down to bone. Although Outerbridge described a differentiation between Grades I1 and 111, he did not use the diameter of the lesion to establish injury severity. In 1989, Noyes and Stabler (17) presented a more comprehensive system for grading articular cartilage lesions of the knee. Their grading system consisted of a detailed assessment of the chondral lesion, rating the articular surface, depth, diameter, and location of the lesion. Noyes and Stabler's classification system was used in the present study because of its extensive detail in grading chondral lesions. The findings of this study indicate that the majority (89%) of patients were able to return to preinjury activity levels and had preservation of the medial, lateral, and patellofemoral joint spaces at 45 months (average) post. In addition, approximately half of the subjects had clinical findings, as determined via the

15 Arthroscopic Abrasion Chondroplasty 141 Analysis of meniscal status revealed that 4 (22.2%) subjects had normal menisci and 14 (77.7%) subjects had subtotal meniscectomies. Twelve (66.6%) subjects had subtotal meniscectomies of their medial meniscus, and 5 (27.7%) subjects had subtotal meniscectomies of their lateral meniscus. Although no significant association was found between meniscal status and SKEF outcome, all of the subjects without meniscal pathology had nearly normal SKEF outcomes. Conversely, 55% of the subjects who had meniscal pathology had abnormal or severely abnormal SKEF classifications. Meniscal pathology decreases the protection of the articular cartilage, resulting in increased articular cartilage loading. Conversely, normal menisci protect the articular cartilage from deleterious forces, as was reflected in the SKEF outcome. Ten (55.6%) subjects were classified as nearly normal on the SKEJ3,5 (27.8%) as abnormal, and 3 (16.7%) as severely abnormal. These data revealed that the clinical results of abrasion chondroplasty were reasonably favorable. X-ray scores for the SKEF were as follows: 15 (83.3%) subjects had normal or nearly normal medial joint spacing, 17 (94.5%) subjects had normal or nearly normal lateral joint spacing, and 16 (88.9%) subjects had normal or nearly normal patellofemoral joint spacing. These data reveal that the joint spaces were preserved in the majority of patients as a result of arthroscopic abrasion chondroplasty. Preservation of these articular spaces is important for maintaining normal joint movement and for reducing the risk of osteoarthritis. The average CKRS score was ; 66% of the subjects had a CKRS score of 70 or higher. Thus, the subjective outcome of the procedure was favorable. Additionally, subjects who scored in the nearly normal category on the SKEF had significantly higher scores on the CKRS. This was attributed to the fact that a knee which had a nearly normal clinical assessment should have had a positive subjective assessment as well. The mean ACRS scores was %. Approximately 80% of the subjects had small chondral lesions, and subjects with small chondral lesions had higher SKEF outcomes. This intuitively makes sense, as smaller lesions should have had fewer deleterious effects on the clinical outcome of the knee. Time to follow-up was analyzed for both the SKEF and CKRS, with results revealing that time was not a factor in the postsurgical objective and subjective components of these two instruments. In other words, the post SKEF and CKRS outcomes were not affected over time. Conclusions Within the constraints of the present study, it was found that arthroscopic abrasion chondroplasty of the knee has a favorable outcome. Overall, patient perception of the surgical outcome was good, and the subjects' ability to return to preinjury activity levels was a predictable outcome post. AdditionalIy, the long-term orthopedic clinical findings of abrasion chondroplasty of the knee joint were favorable, since the medial, lateral, and patellofemoral joint spaces were preserved. However, more study is needed with larger samples and longer follow-up before definitive conclusions about the efficacy of the procedure can be made.

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