Outcomes of Anterior Cruciate Ligament Reconstruction in Patients Older than 50 Years of Age

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1 277 Outcomes of Anterior Cruciate Ligament Reconstruction in Patients Older than 50 Years of Age Theodore S. Wolfson, B.S.E, David M. Epstein, M.D., Michael S. Day, M.D., Bhavesh B. Joshi, D.O., Alan McGee, M.D., Eric J. Strauss, M.D., and Laith M. Jazrawi, M.D. Abstract Background: Anterior cruciate ligament reconstruction (ACLR) has traditionally been reserved for young patients with functional instability. As the aging population continues to grow and embrace a more active lifestyle, it is important to determine if favorable outcomes of ACLR can be achieved in older adults. Methods: Patients greater than 50 years of age undergoing ACLR between January 2001 and September 2006 were identified. Charts were retrospectively reviewed for clinical, pathologic, and radiographic findings. Prospective data was collected at follow-up, including Lysholm Knee Score, Tegner Activity Level Score, International Knee Documentation Committee (IKDC) Subjective Knee Form Score, and Knee Injury and Osteoarthritis Outcome Score (KOOS). Anteroposterior (AP) instability was assessed with use of a KT-2000 arthrometer (MEDmetric, San Diego, CA). Results: Forty-seven patients underwent ACLR with 32 (16 males and 16 females) available at a mean follow-up of 5.0 years (range: 2.2 to 9.0 years). The mean age at the time of operation was 58.4 years (range: 51 to 65 years). At time of final follow-up, the mean side-to-side difference measured by KT-2000 was 1.2 ± 1.3 mm (range: 0 to 4.5 mm). Mean postoperative subjective IKDC score was 80.1 (range: 33 to 100) and Lysholm score was 86.7 (range: 45 to 95). There was no change in Tegner score from pre-injury (range: 0 to Theodore S. Wolfson, B.S.E, Michael S. Day, M.D., Bhavesh B. Joshi, D.O., Alan McGee, M.D., Eric J. Strauss, M.D., and Laith M. Jazrawi, M.D., Department of Orthopaedic Surgery, New York University Hospital for Joint Diseases, New York, New York. David M. Epstein, M.D., Tri-County Orthopedics, Morristown, New Jersey. Correspondence: Laith M. Jazrawi, M.D., Center for Musculoskeletal Care, 333 East 38th Street, New York, New York 10016; laith.jazrawi@nyumc.org. 3) to postoperative (range: 0 to 3). Twelve patients (38%) underwent subsequent knee surgery. All patients were satisfied with the final outcome of their ACLR surgery. Only patellofemoral Outerbridge cartilage grade was associated with worse outcome. Conclusion: ACLR provides symptomatic relief and restoration of function for patients greater than 50 years of age. ACLR should be considered in active older patients with subjective functional instability. There is growing population of active older adults who are susceptible to sports-related injuries, including anterior cruciate ligament (ACL) rupture. 1 According to the U.S. Census Bureau, by the year 2050, the world s population greater than 65 years of age will triple, accounting for 16% of the total population. 2 With the current emphasis on fitness, this aging population continues to adopt a more active lifestyle, placing them at greater risk of associated injury. Although the incidence rate of ACL injury in older adults remains unknown, a national population-based study in New Zealand revealed that adults 45 years of age and older account for 20% of sports-related knee ligament injuries and nearly half of all knee ligament injuries. 3 Surgical intervention is considered standard management of ACL rupture in the young, athletic patient with functional instability. 4-6 However, the treatment of ACL deficiency in older adults remains controversial. Concerns over healing, arthrofibrosis, underlying arthritis, and diminished activity demands in older patients have been raised. 1 Early studies reported favorable outcomes in older patients treated nonoperatively, 7-9 and an upper age limit of 40 years for ACL reconstruction (ACLR) had been proposed. 8 However, conservative management has several limitations. Nonoperative management may fail to correct instability and ultimately predispose to reinjury. As a result, patients are instructed to reduce or modify their activity level. 8,9 Wolfson TS, Epstein DM, Day MS, Joshi BB, McGee A, Strauss EJ, Jazrawi LM. Outcomes of anterior cruciate ligament reconstruction in patients older than 50 years of age. Bull Hosp Jt Dis. 2014;72(4):

2 278 Bulletin of the Hospital for Joint Diseases 2014;72(4): In addition, untreated ACL insufficiency, regardless of age, may contribute to functional disability, subsequent injury, and progressive degenerative changes The age limits for ACLR are continuously being challenged, while many surgeons object to the concept of an age barrier altogether. 17,18 ACLR has been shown to achieve excellent results in the older patient population, with knee stability, function, and patient satisfaction scores similar to those seen in the younger patient population. 1,18-26 Studies comparing surgical and nonoperative management in older patients demonstrate superior function and patient satisfaction with surgery without significant differences in rates of arthrofibrosis. 21,24 Expected-value decision analysis further supports the utility of ACL reconstruction over nonoperative management in patients aged 40 years or older. 27 These promising results have led investigators to conclude that ACL reconstruction is a viable treatment option for older patients with persistent instability or who wish to return to a high level of activity. 1,18,20,21,23,25,26,28 Although the classic 40-year-old age barrier may be obsolete, few studies have evaluated outcomes of ACL reconstruction in patients beyond 50 years of age. 1,26 The primary objective of the present study is to investigate the outcomes of ACL reconstruction in patients greater than 50 years of age performed at our institution. We also sought to compare our results to published series in this patient population and identify variables that influence outcomes in this age group. We hypothesized that patients greater than 50 years of age undergoing ACLR would have comparable outcomes to the younger patient population. Materials and Methods Patient Selection After approval from the New York University School of Medicine (NYU SoM) Institutional Review Board (IRB), the medical records database at our institution was retrospectively reviewed to identify all patients greater than 50 years of age who underwent ACLR between January 2001 and September Patients with less than 2 years of follow-up from the date of surgery were excluded from the search. The charts of patients included in the study group were reviewed to collect demographic and operative data. Mechanism of injury and associated injuries were recorded. Intraoperative data included graft type, method of fixation, concomitant pathology and procedures, and articular cartilage grading. Postoperative data included length of follow-up, complications, reinjury, and the need for additional procedures. Data Collection and Analysis Subjective prospective data was collected at follow-up with patient-reported questionnaires, including the Lysholm Knee Score, Tegner Activity Score, International Knee Documentation Committee (IKDC) Subjective Knee Form Score, and Knee Injury and Osteoarthritis Outcome Score (KOOS). The operative attending, orthopaedic sports medicine trained fellow, or orthopaedic senior resident performed postoperative physical examinations. Objective assessment of anteroposterior (AP) stability was performed with use of the KT-2000 arthrometer (MEDmetric, San Diego, CA). Instability was further evaluated with the Lachman test, anterior drawer test, and pivot-shift test. Active range of motion was measured with a goniometer, while quadriceps and hamstring strength were assessed manually. Postoperative thigh circumference was measured at 10 cm above the upper pole of the patella with full extension of the knee. The knee was evaluated for medial and lateral joint line tenderness, as well as varus and valgus stability at full extension and 30 of flexion. Radiographic imaging consisted of anteroposterior and lateral 45 weightbearing views. The IKDC radiographic scoring system was employed to grade radiographic changes of the medial, lateral, and patellofemoral compartments. Tests and examinations were performed bilaterally such that results from the operative leg could be compared to those of the contralateral lower extremity. Postoperative graft failure was defined as either the need for ACL revision surgery or abnormal laxity evidenced by a 2+ Lachman, 1+ pivotshift, or greater than 5 mm side-to-side difference in the operative knee. Statistical Analysis This study retrospectively collected data from all patients undergoing ACLR over a set period of time. Therefore, statistical power was not considered during subject enrollment. The unpaired independent t test was used to compare the mean with variances among all study outcome parameters. Rank sum testing and Spearman s rank correlation coefficient were employed to detect associations between variables. The level of statistical significance was set at p < All data were analyzed with the use of STATA software (Version 10, StataCorp LP, College Station, TX, USA). Surgical Technique ACLR was performed with a transtibial, single bundle technique. Grafts were either allograft or autograft. Allograft tissue included tibialis anterior, tibialis posterior, patellar tendon, and Achilles. Autograft tissue consisted of either bone-patellar tendon-bone (BPTB) or hamstring. Fixation of soft tissue grafts was accomplished with cross pin fixation, Endobutton CLTM (Smith and Nephew, London, UK), or interference screw fixation on the femoral side and interference screw fixation with or without the use of a staple on the tibial side. For BPTB graft and Achilles graft, metal or bioabsorbable interference screw fixation was used. Articular Cartilage Grading Articular cartilage of the medial, lateral, and patellofemoral compartments was graded by the surgeon based on intraoperative findings using the Outerbridge grading of cartilage lesions. 29 The Outerbridge classification system ranges from Grades 0 to IV (Table1).

3 279 Table 1 Outerbridge Classification of Chondral Lesions Cartilage Grade Criteria 0 Normal cartilage I Cartilage with softening and swelling II Partial thickness defect with fissures on the surface that do not reach subchondral bone or exceed 1.5 cm in diameter III Fissuring to the level of subchondral bone in the area with a diameter more than 1.5 cm IV Exposed subchondral bone Rehabilitation Protocol All patients underwent a standardized rehabilitation protocol. In the first postoperative week, patients were instructed to perform quadriceps sets, straight leg raises, and patellar mobilization exercises. From week 2 to 4, the patient was referred to a physical therapist and instructed to begin heel slides, wall slides, range of motion exercises, closed chain exercises, and stationary bicycle. During postoperative week 6, limited open chain exercises were initiated, as well as balance and proprioceptive exercises. At 3 months, patients were permitted to begin jogging, and at 4 months, patients were advanced to sport-specific functional training. Full return to contact sports was allowed at 6 to 7 months following surgery. Results Study Population From January 2001 to September 2006, 47 patients over the age of 50 underwent ACLR at our institution. Four patients were excluded from our study; one patient underwent a high tibial osteotomy, one patient had a concomitant tibial plateau fracture, one patient had a history of polio, and one patient underwent bilateral total knee arthroplasty. Eleven patients were not available for follow up; six refused, three could not be found, one moved out of state, and one would not participate for personal reasons. Ultimately, 32 patients were available for follow-up at least 2 years following their ACLR (Fig. 1). Table 2 ACL Graft Types Allograft Number Autograft Number Tibialis Anterior 16 BPTB 4 Patella Tendon 8 Hamstring 2 Tibialis Posterior 1 Achilles Tendon 1 Total 26 6 BPTB = bone-patellar tendon-bone. Demographics Sixteen (50%) females and 16 (50%) males were included in the study cohort. The mean age of patients enrolled was 58.4 years (range: 51 to 65 years), and the mean followup was 5.0 years (range: 2.2 to 9.0 years). Graft types are displayed in Table 2. Instability and Graft Failure Five patients (15%) were noted to have a 1+ Lachman on examination. The average side-to-side difference was 1.2 ± 1.3 mm (range: 0 to 4.5 mm). The distribution of KT-2000 side-to-side differences is reported in Table 3. There were two cases (6%) of graft failure observed. One traumatic graft failure occurred in a patient with a bone-patella tendon bone autograft. Revision was performed with a tibialis anterior allograft. One patient was found to have a 2+ pivot-shift on follow-up exam. However, the patient reported that he was satisfied with the surgery and did not experience symptomatic instability requiring revision surgery. Intraoperative Cartilage Grading Outerbridge cartilage scores were determined for the patellofemoral, medial, and lateral compartments (Table 4). Over half of all patients were found to have Grade III or IV articular cartilage pathology in either the patellofemoral or medial compartment. Reoperation Twelve patients (38%) had subsequent knee surgery. Two patients (6%) underwent removal of painful tibial hardware, three (9%) required arthroscopic lysis of adhesions for postsurgical knee stiffness, and three patients (9%) had arthroscopic partial medial meniscectomy. One patient (3%) required an allograft revision 2 years after primary ACLR with BPTB autograft. The patient also underwent a partial Table 3 Side-to-Side Differences in KT-2000 Measurement Side-to-Side Difference Number of Patients Figure 1 Patient enrollment data (LTFU = lost to follow-up). 0-3 mm mm 6 > 5 mm 0

4 280 Bulletin of the Hospital for Joint Diseases 2014;72(4): Table 4 Outerbridge Cartilage Scores* Cartilage Grade Patellofemoral Medial Lateral 0 16 (50%) 14 (44%) 20 (63%) I 2 (6%) 2 (6%) 3 (9%) II 0 (0%) 3 (9%) 1 (3%) III 12 (38%) 14 (44%) 8 (25%) IV 2 (6%) 4 (13%) 0 (0%) *Values represent the absolute frequency (percentage of patients). lateral meniscectomy with removal of an osteochondral loose body during the procedure. Subjective Outcomes All patients reported that they were satisfied with the final results of surgery. One patient who underwent revision surgery after traumatic re-rupture ultimately reported satisfaction with the surgery. At the time of final follow-up, mean subjective IKDC score was 80.1 (range: 33 to 100), and mean Lysholm score was 86.7 (range: 45 to 95). The KOOS score is broken down into five subscores: pain, symptoms, activities of daily living (ADL), sport, and quality of life (QoL). The mean KOOS pain score was 86.6 (range: 36.1 to 100), symptoms score was 82.9 (range: 28.6 to 100), ADL score was 92.2 (range: 53 to 100), sport score was 78.4 (range: 40 to 100), and QoL score was 77.0 (range: 31.3 to 100). Tegner Activity Level score improved from pre-injury (mean: 1.4; range: 0 to 3) to postoperative (mean: 2.1; range: 0 to 3) but did not achieve statistical significance. Outcome scores are summarized in Table 5. (Fig. 2). The degree of arthrosis in the operative knee did not correlate with worse outcomes. Risk Factors for Poor Outcome Of all preoperative and operative variables collected, only the patellofemoral compartment Outerbridge grade showed a statistically significant correlation with outcome scores (p < 0.05). Increase in the patellofemoral Outerbridge grade was associated with worse outcome scores (Table 6). Linear regression analysis revealed that for each incremental increase in Outerbridge patellofemoral cartilage grade outcome scores decreased by a mean of 5.3 points (range: 4.7 to 5.7; p < 0.05). Discussion As the aging population grows and embraces a more active lifestyle, the rates of sports-related and activity-related injury will continue to rise. As a result, older adults may be candidates for anterior cruciate ligament reconstruction (ACLR) Radiographic Findings Twenty-eight patients (86%) underwent radiographic imaging at time of follow-up with anteroposterior and lateral 45 weightbearing views. Greater joint space narrowing, indicating a higher degree of arthrosis, was detected in both the medial and lateral compartments of the operative extremity compared to the contralateral extremity (p < 0.05) Table 5 Outcome Scores in Patients Greater than 50 Years of Age Undergoing ACLR Outcome Measure Score ± SD Range IKDC 80.1 ± Lysholm 86.7 ± KOOS Pain 86.6 ± Symptom 82.9 ± ADL 92.2 ± Sport 78.4 ± QoL 77.0 ± Tegner 2.1 ± Figure 2 Anteroposterior radiograph taken at final follow-up after ACLR showing IKDC Grade D changes of the operative knee medial compartment.

5 281 Table 6 Patellofemoral Outerbridge Cartilage Grade is Associated with Worse Outcome Scores Outcome measure Rho (ρ) p-value IKDC Lysholm KOOS Pain < 0.01 Symptom < ADL Sport QoL later in life. While favorable outcomes may be achieved nonoperatively, residual instability and activity restrictions may be undesirable to a mounting number of older adults. Traditionally, age beyond 40 years was viewed as a relative contraindication for ACLR. However, over the last two decades, studies have challenged this principle, demonstrating positive outcomes in patients over 40 years of age As the age threshold for ACLR continues to climb, it is important to address outcomes in even older age groups. Patients with functional demands during sports or daily activities may be eligible for ACLR during their sixth or even seventh decades of life. The number of studies evaluating clinical outcomes of ACLR in patients greater than 50 years of age is limited. To our knowledge, the current study includes the largest cohort of patients over 50 years of age undergoing ACLR reported in the English language literature. The current study demonstrates that high rates of patient satisfaction can be achieved in patients over 50 years of age undergoing ACLR. Although we report a high incidence of residual instability (19%) and reoperation (38%) in this population, patient satisfaction was not influenced by laxity or reoperation. Residual instability was mild as characterized by 1+ Lachman on examination for the majority of patients (15%) with instability. No patients were found to have greater than 5 mm side-to-side difference on KT-2000 assessment. Elevated rates of reoperation may be attributed to the extended length of follow-up in the present study compared to other studies ,28 Patients in the present study had a low baseline level of activity and minimal involvement in sports evidenced by relatively low pre-injury Tegner Activity Level scores. ACLR may be an effective solution even for older patients with low functional demands. The majority of grafts used for ACLR in the study population were allograft tissue. In older patients, the benefit of decreased donor site morbidity and faster initial recovery from surgery are thought to outweigh the small risks of disease transmission and slower tissue incorporation. 30 A retrospective review of ACL reconstructions comparing allograft versus autograft reported a significantly higher average patient age in the allograft group (33.1 vs years). 31 Generally, outcomes with allograft are comparable to those with autograft. 29,32 In the current study, graft choice did not affect outcomes. Operative knees demonstrated significant articular cartilage pathology and radiographic signs of arthrosis. More than half of the patients were found to have high-grade cartilage lesions intraoperatively. However, patellofemoral compartment Outerbridge cartilage grade was the only variable associated with poor outcomes. Age, BMI, concomitant injury, pre-injury Tegner score, radiographic scores, and cartilage grades for the medial and lateral compartments did not affect outcome scores. However, it is possible that in determining patient eligibility for surgery, these variables were already taken into account. Almost two decades ago, Ciccotti and coworkers 8 retrospectively reviewed the records of 52 patients between the ages of 40 and 60 years with rupture of the anterior cruciate ligament to determine the results of aggressive nonoperative treatment. After a 7-year follow-up, Lysholm and Gillquist score was 82 points, with 83% of patients satisfied with their outcome. However, 13 substantial re-injuries had occurred in 11 patients (37%) during the follow-up period. The investigators concluded that patients who had combined instabilities and who wished to resume competitive sports activity that required pivoting were dissatisfied. Such patients may need operative reconstruction to achieve their goals. Later studies investigated the role of ACLR in older adults. Barber and colleagues 18 prospectively evaluated the outcomes of ACLR in patients older than 40 years of age compared to patients younger than 40 years of age. No difference in Lysholm scores was detected between the two groups. The investigators concluded that age greater than 40 years is not a barrier to ACL reconstruction. More recently, Blyth and associates, 26 in a prospective study of ACLR in patients over 50 years old, showed equivalent results to younger cohorts. The mean patient age was 54.5 years old, and patients were followed for a mean of 46 months. Lysholm and Tegner scores increased significantly from preoperative values to those at final follow up, with 83% knees found to be normal or nearly normal based on IKDC outcome scores. The mean KT-1000 measurement was a 2.7 mm side-to-side difference. The investigators demonstrated that poor results were associated with advanced articular degenerative changes, consistent with our findings. Nearly 100% of patients reported improvement in stability and function of the knee. Our results are compared with published studies evaluating ACLR in the older patient population (Table 7). The present study had several weaknesses. First, the study population was identified retrospectively, limiting standardization of surgery and follow-up. Additionally, this study was not blinded. Many follow-up examinations were performed by the operative surgeon, which may affect the reporting of outcomes. Furthermore, no control group was included to adjust for confounding variables. Lastly, there was a high number of patients (26%) lost to follow up. Despite these limitations, this study was powered by a

6 282 Bulletin of the Hospital for Joint Diseases 2014;72(4): Table 7 Published Studies Evaluating Clinical Outcomes of ACLR of Patients over 40 Years of Age Study Pts* Age (Years) Follow-up (Months) Lysholm Tegner Side-to-Side Difference (mm) Re-Injury Notes Epstein et al (2013) (50-65) 60 (26-108) 81.7 (45-95) 2.1 (0-3) 1.2 (0-4.5) 6% graft failure 28% reoperation 100% patient satisfaction; PF Outerbridge cartilage grade 3 and 4 associated with poor outcomes Barber et al (2010) (40-55) 35 (24-58) 89.5 (59-100) 6.2 (3-10) 1.4 NR BPTB allograft; no difference with cohort of patients < 40 years of age Marquass et al (2007) (40-61) (69-100) 4.5 (3-8) NR NR Hamstring allograft; no correlation between functional outcome and age Stein et al (2006) (49-64) 24 (9-48) 92 (61-100) NR 2.0 (0-4) NR 79% good/excellent results; 100% patient satisfaction Blyth et al (2003) (50-66) 46 (24-95) 93 (76-100) 5.2 (3-8) 2.7 (0-7) 7% reinjury 17% reoperation Outerbridge cartilage grade 3 and 4 associated with poor outcomes Plancher et al (1998) (40-60) 55 (26-117) 94 (69-100) NR 1.4 (0-9) 26% reoperation BPTB allograft; 100% patient satisfaction Heier et al (1997) (40-62) 37 (24-69) 91 (75-100) NR 2.2 4% graft failure 7% reoperation BTPB allograft; 76% returned to preoperative activity level Barber et al (1996) (40-52) NR 89% good/excellent results; no difference with cohort of patients < 40 years of age relatively large sample of older adults undergoing ACLR at a single institution with current techniques and long-term clinical and radiographic follow-up. Prospective follow-up revealed a perfect rate of patient satisfaction in patients greater than 50 years of age undergoing ACLR at our institution, regardless of residual instability or reoperation. The degree of patellofemoral arthritis may be associated with poor outcomes after ACLR and should be considered when weighing the decision to recommend operative treatment. Additionally, patients should be made aware of high rates of reoperation and arthrosis prior to undergoing ACLR. Despite these considerations, ACLR in patients older than 50 years of age can offer symptomatic relief, restoration of function, and return to athletic activity. Disclosure Statement None of the authors have a financial or proprietary interest in the subject matter or materials discussed, including, but not limited to, employment, consultancies, stock ownership, honoraria, and paid expert testimony. References 1. Stein DA, Brown H, Bartolozzi AR. Age and ACL reconstruction revisited. Orthopedics Jun;29(6): United States Census Bureau. (June 23, 2009). Census Bureau Reports World s Older Population Projected to Triple by 2050 [Press Release]. Retrieved from releases/archives/international_population/cb09-97.html. Accessed 12/5/ Gianotti SM, Marshall SW, Hume PA, Bunt L. Incidence of anterior cruciate ligament injury and other knee ligament injuries: a national population-based study. J Sci Med Sport Nov;12(6): doi: /j.jsams Andersson C, Odensten M, Good L, Gillquist J. Surgical or non-surgical treatment of acute rupture of the anterior cruciate ligament. A randomized study with long-term follow-up. J Bone Joint Surg Am Aug;71(7): Spindler KP, Wright RW. Clinical practice. Anterior cruciate ligament tear. N Engl J Med Nov 13;359(20): doi: /NEJMcp Beaufils P, Hulet C, Dhenain M, et al. Clinical practice guidelines for the management of meniscal lesions and isolated lesions of the anterior cruciate ligament of the knee in adults. Orthop Traumatol Surg Res Oct;95(6): doi: /j.otsr Jokl P, Kaplan N, Stovell P, Keggi K. Non-operative treatment of severe injuries to the medial and anterior cruciate ligaments of the knee. J Bone Joint Surg Am Jun;66(5): Ciccotti MG, Lombardo SJ, Nonweiler B, Pink M. Non-operative treatment of ruptures of the anterior cruciate ligament

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