ACL Reconstruction Patients Have Increased Risk of Knee Arthroplasty at 15 Years of Follow-up: Data from the Norwegian Knee Ligament Register and the Norwegian Arthroplasty Register from 2004 to 2020.

Anterior cruciate ligament (ACL) injury is considered a risk factor for osteoarthritis. The primary aim of the present study was to investigate the cumulative risk of, and risk factors associated with, a subsequent knee arthroplasty after an ACL reconstruction at up to 15 years of follow-up. The secondary aim was to compare the relative risk of knee arthroplasty after ACL reconstruction compared with that in the general population. Methods: Data were analyzed by combining data from 2 national registries, the Norwegian Knee Ligament Register and the Norwegian Arthroplasty Register. The cumulative risk of knee arthroplasty after undergoing ACL reconstruction was calculated as 1 minus the corresponding Kaplan-Meier estimate, and possible risk factors for knee arthroplasty after ACL reconstruction were assessed in a Cox regression model with hazard ratios (HRs) as estimated effect measurements. The relative risk of knee arthroplasty for patients managed with ACL reconstruction as compared with that in the general population was calculated in stratified age groups. Results: From the study population of 27,122 knees, 115 knees underwent knee arthroplasty. We found a 1.1% (95% confidence interval [CI], 0.9 to 1.4) cumulative risk of knee arthroplasty 15 years after ACL reconstruction. Deep cartilage injury, ICRS (International Cartilage Repair Society) grade 3 to 4 (HR, 4.8; 95% CI, 3.1 to 7.6), revision of the ACL (HR, 3.9; 95% CI, 2.2 to 7.1), and a 2-year postoperative KOOS Sport/Recreation subscore of <44 (HR, 3.1; 95% CI, 1.5 to 6.2) were important risk factors for knee arthroplasty. We found a higher risk of knee arthroplasty at the age of 30 to 39 years after a previous ACL reconstruction as compared with the general population (relative risk, 3.3; 95% CI, 1.6 to 6.7). Conclusions: Fifteen years after an ACL reconstruction, the overall cumulative risk of knee arthroplasty was 1.1%. Cartilage injury at the time of ACL reconstruction, revision ACL reconstruction, and a KOOS Sport/Recreation subscore of <44 (at 2 years postoperatively) were major risk factors for subsequent knee arthroplasty. We found a 3.3-times higher risk of knee arthroplasty at the age of 30 to 39 years after a previous ACL reconstruction as compared with that in the general population. Level of Evidence: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Cementless unicompartmental knee arthroplasty results in higher pain levels compared to the cemented technique: a prospective register study.

PURPOSE: In recent years, the preferred fixation method for unicompartmental knee arthroplasty (UKA) has changed from cemented to cementless. The aim of this study was to compare patient-reported outcome measures (PROMs) from the cemented versus cementless techniques two- and twelve-months post-operation. METHODS: From 2015 to 2019, 187 cemented and 261 cementless UKAs were included based on an institutional registry. The Oxford Unicompartmental Knee System™ (Zimmer Biomet, Bridgend, United Kingdom) was used for all patients. Three experienced surgeons performed all procedures. Data were collected pre- and peroperatively, and at two- and twelve-months postoperatively. PROMs included pain (evaluated on a numeric rating scale [NRS] during activity and at rest), and knee function (evaluated with the disease-specific short form of the Knee injury and Osteoarthritis Outcome Score [KOOS-PS]). Patients also rated postoperative joint function (better, unchanged, uncertain or worse) and were asked, "based on your experience to date, would you go through the surgery again?". Duration of surgery was noted and revisions during the first post-operative year were evaluated. RESULTS: The cemented group reported significantly lower activity-related pain at both two- and twelve-month follow-up. This was also the case for pain at rest at twelve-month follow-up, and KOOS-PS at two-month follow-up. Duration of surgery (adjusted for surgeon differences) was eight minutes less on average with the cementless technique. Eleven prosthetic joint infections (PJIs) were found following the cementless fixation technique compared to three using the cemented implant. CONCLUSION: UKA cases with cemented implants had lower pain scores during activity two and twelve months after surgery compared with those who had cementless implants. Differences in favor of the cemented group were also found for pain at rest one year after surgery and for KOOS-PS two months after. Surgery was significantly shorter in duration in the cementless group, but a relatively high number of PJIs were found in that same group. LEVEL OF EVIDENCE: Level II.

Clinical outcome after knee ligament reconstruction with tendon allografts.

PURPOSE: The purpose of this study is to investigate the clinical outcome for patients after knee ligament reconstructions with allografts at a university hospital. METHODS: A total of 33 patients received allografts for reconstructive knee surgery between 2007 and 2017. The follow up evaluation consisted of a clinical knee examination including evaluation of range of motion (ROM), lateral and medial laxity, the Lachman test, the Pivot shift test, the sag test, the posterior drawer test and checking for patellofemoral pain. The following patient-reported outcome measures (PROMs) were used; the Lysholm Function Score, the Tegner activity score, and the Knee injury and Osteoarthritis Outcome Score (KOOS). RESULTS: Twenty-one (64%) patients were available for the follow-up evaluation and the mean follow-up time was 4.8 years. A total of 16 out of 21 patients had multiligament injuries of which the ACL was the ligament most frequently ruptured. At the time of follow-up, 14 out of 16 patients (87%) with ACL injury had Lachman test grade 0 or grade 1 + , and 12 out of 13 (92%) had a pivot shift grade 0 or 1 + . The mean Lysholm Score was 74. All mean KOOS subscale values were ≥ 59 at the follow-up. The preoperative Tegner activity score was 3 (range, 1-6) and 4 (range, 2-6) at follow up. There were no deep postoperative infections. A total of 19 out of 21 patients (90%) reported that they would have undergone surgery again had they known the clinical outcome in advance. CONCLUSIONS: The patients improved from the preoperative score to the follow-up score in the knee-related Quality of Life (QoL) KOOS subscale. None of the patients were diagnosed with deep postoperative infections.

No effect of graft size or body mass index on risk of revision after ACL reconstruction using hamstrings autograft.

PURPOSE: The current study investigated the distribution of hamstrings graft size and body mass index and any potential effect on the risk of revision surgery in a large prospective cohort of patients undergoing ACL reconstruction. More specifically, the aim of the study was to investigate whether larger graft size or smaller BMI would decrease the risk of revision after ACL reconstruction. METHODS: A total of 4029 patients, prospectively registered in the Norwegian Knee Ligament Registry, were included in the study. Univariate Kaplan-Meier survival analyses (with log-rank tests) and the Cox proportional hazard (PH) regression model were applied to compare risk of revision between groups of patients. Mutual adjustment for gender, age, activity at the time of injury and fixation method of the graft was performed. RESULTS: Graft sizes spanned from 5.5 to 11.0 mm and the median of 8.0 mm was reported in 42% of patients in the cohort. BMI was reported from 15 to 57 with a median of 25. 46% of patients were classified as overweight (WHO standards), while 23% of patients were obese. At a median of 2.5 years after surgery, 150 patients had undergone revision surgery. Although certain effects were seen in the unadjusted analyses, neither graft size (diameter) nor patient BMI did affect the risk of undergoing revision surgery in the adjusted analyses. CONCLUSIONS: Graft size and BMI was not found to be independent risk factors for undergoing ACL revision surgery. In contrast to other studies, graft size of 8 mm or larger did not have a better outcome than smaller graft sizes. A relatively large group of overweight patients undergoing ACL surgery reflects the general increase in weight seen in Western societies. Although the current study differs from previous findings, it might indicate that graft diameter is less important than previously stated. LEVEL OF EVIDENCE: Cohort study, II.

Correction to: No effect of graft size or body mass index on risk of revision after ACL reconstruction using hamstrings autograft.

Unfortunately, the author Jon Olav Drogset was incorrectly published in the original version and updated here. The original article has been corrected.

Autologous BPTB ACL Reconstruction Results in Lower Failure Rates Than ACL Repair with and without Synthetic Augmentation at 30 Years of Follow-up: A Prospective Randomized Study.

BACKGROUND: The aim of this study was to compare the 30-year follow-up results after treatment of anterior cruciate ligament (ACL) ruptures with 3 different surgical procedures. METHODS: A total of 150 patients with acute rupture of the ACL who were managed between 1986 and 1988 were randomized into 1 of 3 open repair methods: acute primary repair (n = 49), acute repair with a synthetic ligament augmentation device (LAD) (n = 50), or reconstruction with an autologous bone-patellar tendon-bone (BPTB) graft with retention of the ACL remnants (n = 51). The 30-year follow-up included evaluation of clinical findings, the Tegner and Lysholm questionnaires, radiographic examination, and registration of revisions and knee arthroplasties. RESULTS: A total of 113 patients (75%) were available for the follow-up evaluation; 39 patients were in the primary repair group, 39 in the LAD group, and 35 in the BPTB group. Through telephone calls and investigation of patient medical records, 40 of these patients were excluded from further analyses because of revision surgery, knee arthroplasty in the involved or contralateral knee, or ACL reconstruction in the contralateral knee. One patient in the BPTB group had undergone revision ACL reconstruction compared with 12 in the primary repair group (p = 0.002) and 9 in the LAD group (p = 0.015). Seven patients had undergone knee arthroplasty in the involved knee, with no significant difference among the groups. In the remaining patients, no significant differences were found among the 3 groups with regard to range of motion, laxity, or Tegner and Lysholm scores. Radiographic evidence of osteoarthritis, defined as an Ahlbäck grade of 2 through 5, was found in 42% of the operatively treated knees, with no significant differences among the groups. CONCLUSIONS: In the present 30-year follow-up results of a randomized controlled study, the BPTB graft augmented with the remnants of the ruptured ligament provided superior results with regard to the number of revisions compared with both the primary repair and LAD groups. No significant differences were found with respect to range of motion, laxity, activity, function, radiographic evidence of osteoarthritis, and knee arthroplasties. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Anterior Cruciate Ligament Reconstruction Using a Bone-Patellar Tendon-Bone Graft With and Without a Ligament Augmentation Device: A 25-Year Follow-up of a Prospective Randomized Controlled Trial.

BACKGROUND: Various grafts and ligament augmentation devices (LADs) have been used in the search for optimal reconstruction of the anterior cruciate ligament (ACL). PURPOSE: To compare 25-year follow-up results after ACL reconstruction using a bone-patellar tendon-bone (BPTB) graft with or without the Kennedy LAD. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: One hundred patients undergoing ACL reconstruction between 1991 and 1993 were randomized into 2 groups: reconstruction using a BPTB graft alone (BPTB group, 51 patients) or a BPTB graft with the Kennedy LAD (LAD group, 49 patients). The 25-year follow-up evaluation included a clinical knee examination, patient-reported outcome measures, and an assessment of radiological osteoarthritis (OA) according to the Ahlbäck classification. Additional outcomes were reruptures and knee arthroplasty. RESULTS: Ninety-three patients (93%) were available for the follow-up evaluation: 48 patients in the BPTB group and 45 in the LAD group. Through telephone calls, 26 patients were excluded from further investigation because of reruptures and arthroplasty in the knee of interest; 67 patients were further investigated. A total of 43 of 44 (98%) and 42 of 44 (95%) patients had negative or 1+ Lachman and pivot-shift test results, respectively. The mean Lysholm score was 85 for the BPTB group and 83 for the LAD group. All mean Knee injury and Osteoarthritis Outcome Score (KOOS) subscale values were ≥73. There were no statistically significant differences between groups in any of these outcomes or regarding the Tegner score, radiological classification of OA, or number of ACL reruptures. Signs of radiological OA were detected in all patients, and severe radiological OA (Ahlbäck grade III, IV, or V) was detected in 32% of patients in the BPTB group and 21% of patients in the LAD group (P = .37). There were 12 patients in the BPTB group and 7 in the LAD group who had documented reruptures (P = .40). One patient in the BPTB group and 6 in the LAD group underwent knee arthroplasty (P = .054). CONCLUSION: In the present study, there were no statistically significant differences between groups in any of the outcomes. After 25 years, 19% of patients had reruptures, 27% had severe radiological OA, and 7% underwent knee arthroplasty.

Graft fixation influences revision risk after ACL reconstruction with hamstring tendon autografts.

Background and purpose - A large number of fixation methods of hamstring tendon autograft (HT) are available for anterior cruciate ligament reconstruction (ACLR). Some studies report an association between fixation method and the risk of revision ACLR. We compared the risk of revision of various femoral and tibial fixation methods used for HT in Scandinavia 2004-2011. Materials and methods - A register-based study of 38,666 patients undergoing primary ACLRs with HT, with 1,042 revision ACLRs. The overall median follow-up time was 2.8 (0-8) years. Fixation devices used in a small number of patients were grouped according to design and the point of fixation. Results - The most common fixation methods were Endobutton (36%) and Rigidfix (31%) in the femur; and interference screw (48%) and Intrafix (34%) in the tibia. In a multivariable Cox regression model, the transfemoral fixations Rigidfix and Transfix had a lower risk of revision (HR 0.7 [95% CI 0.6-0.8] and 0.7 [CI 0.6-0.9] respectively) compared with Endobutton. In the tibia the retro interference screw had a higher risk of revision (HR 1.9 [CI 1.3-2.9]) compared with an interference screw. Interpretation - The choice of graft fixation influences the risk of revision after primary ACLR with hamstring tendon autograft.

Lower risk of revision with patellar tendon autografts compared with hamstring autografts: a registry study based on 45,998 primary ACL reconstructions in Scandinavia.

BACKGROUND: A number of studies have found comparable results after anterior cruciate ligament (ACL) reconstruction with patellar tendon autografts and hamstring autografts; however, few studies have been large enough to reveal differences in risk of revision with regard to clinical and demographic factors. PURPOSE: To present the distribution of grafts for ACL reconstruction based on data in the Scandinavian ACL registries and to compare the risk of revision between patellar tendon autografts and hamstring autografts. Potential associations with other clinical and demographic factors were also explored. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: A total of 45,998 primary ACL reconstructions, including 6736 patellar tendon autografts and 38,666 hamstring autografts, were identified in the Scandinavian ACL registries. The overall median follow-up time was 3 years (range, 0-8 years). To compare the risk of revision between groups of patients, univariate Kaplan-Meier analysis (with log-rank test) and the Cox proportional hazard regression model were applied. The hazard rate ratio with 95% CI was reported as a measure of effect. RESULTS: Patellar tendon and hamstring autografts were used in 14.6% and 84.1% of the patients, respectively. The remaining patients received allografts, direct sutures, or other graft types (1.3%). The primary ACL injury occurred during soccer, team handball, or alpine activities in 67.5% of the patients in the patellar tendon group and 66.2% in the hamstring group. A total of 156 patients in the patellar tendon group and 1042 patients in the hamstring group underwent revision. The overall risk of revision was significantly lower in the patellar tendon group versus the hamstring group (hazard rate ratio = 0.63; 95% CI, 0.53-0.74), and it decreased with increasing age at surgery, although not strictly linearly. The lower risk of revision in the patellar tendon group was consistently observed across subgroups of patient sex, age, and concomitant cartilage injury (P > .05, test for interaction) but seemed to be slightly more pronounced for patients injured during certain pivoting activities (soccer, team handball, and alpine activities) compared with other activities (hazard rate ratio = 0.57 vs 0.81; P = .058, test for interaction). CONCLUSION: The majority of primary ACL reconstructions in Scandinavia are performed with hamstring autografts. Results from the present large prospective study show that patients receiving patellar tendon autografts have a statistically significantly lower risk of revision compared with patients receiving hamstring autografts.

Femoral fixation of hamstring tendon grafts in ACL reconstructions: the 2-year follow-up results of a prospective randomized controlled study.

PURPOSE: Hamstring tendon grafts are commonly used in anterior cruciate ligament (ACL) reconstructions. A number of fixation devices are available; however, several have limited clinical support. To our knowledge, no randomized controlled study comparing the EZLoc and the Bone Mulch Screw for femoral fixation in ACL reconstruction exists. Therefore, the purpose of this study was to compare the results following the use of these two femoral fixation devices. Time in surgery for the two methods was also to be compared. METHODS: A total of 110 patients between 18 and 45 years old at two orthopaedic departments, A (n = 55) and B (n = 55), were randomized to ACL reconstruction with femoral fixation of the hamstring graft with either the EZLoc or the Bone Mulch Screw. Surgical time was measured for each group. The patients were evaluated after 6 weeks and 3, 6, 12 and 24 months. The clinical examination included range of motion, evaluation of intraarticular swelling, tenderness at the lateral femoral condyle, the Lachman test, the Pivot shift test and the KT-1000 arthrometer. In addition, the visual analogue scale score for pain, the Tegner activity score, the Lysholm functional score and the knee injury and osteoarthritis outcome score were recorded. Knee extension and flexion muscle strength were also measured with a Biodex. RESULTS: There were no significant differences in any of the parameters mentioned above at the 2-year follow-up evaluation. Three patients in each group underwent revision ACL reconstruction during the study. More than 95% of the knees in both groups were found to be stable. Good to excellent results were found for all selected knee scores in both groups. There were no statistically significant differences between the two groups in any of the muscle strength parameters. Time in surgery was statistically significantly shorter in the EZLoc group compared with the Bone Mulch group. CONCLUSION: There were no statistically significant differences in clinical findings, knee scores or in muscle strength between the EZLoc group and the Bone Mulch group at the 2-year follow-up evaluation. Time in surgery was statistically significantly shorter for patients undergoing ACL reconstruction with hamstring grafts when the EZLoc femoral fixation device was used. LEVEL OF EVIDENCE: II.

Long-term follow-up of patellar tendon grafts or hamstring tendon grafts in endoscopic ACL reconstructions.

PURPOSE: Several studies compare the short- and long-term results of anterior cruciate ligament (ACL) reconstruction using bone-patellar tendon-bone (BPTB) graft or double-looped semitendinosus and gracilis (DLSG) graft. However, no studies evaluate the long-term results of BPTB grafts fixed with metal interference screws and DLSG grafts fixed with the Bone Mulch Screw and the Washer Loc. This prospective randomized multicentre study has the null hypothesis that there is no difference in long-term outcome between the two procedures. METHODS: A total of 114 patients with a symptomatic ACL rupture were randomized to reconstruction with either a BPTB graft (N = 58) or a DLSG graft (N = 56). Follow-up was conducted after one, two and seven years. At the seven-year follow-up, 102 of the 114 patients (89%) were available for evaluation; however, 16 of these by telephone-interview only. RESULTS: Ten patients in the BPTB group and 19 patients in the DLSG group underwent additional knee surgery (P = 0.048), two and three, respectively, of these were ACL revisions (n.s.). The total flexion work was lower in the DLSG group (P = 0.001). The mean peak flexion torque and extension work, however, showed no difference between the groups. No significant differences were found between the groups regarding the Tegner activity score, the Lysholm functional score, the Knee injury and osteoarthritis outcome score (KOOS), subjective knee function, anterior knee pain or mobility. There was no significant difference in laxity between the groups on the Lachman test or the KT-1,000 maximum manual force test. CONCLUSIONS: Both grafts and fixation methods resulted in satisfactory subjective outcome and objective stability. Both these methods can therefore be considered as suitable alternatives for ACL reconstructions. LEVEL OF EVIDENCE: II.

Inferior results after revision ACL reconstructions: a comparison with primary ACL reconstructions.

PURPOSE: Anterior cruciate ligament (ACL) ruptures are common, especially among young athletes, and such injuries may have considerable impact on both sport careers and everyday life. ACL reconstructions are successful for most patients, but some suffer from persistent giving-way symptoms and/or re-ruptures requiring revision surgery. The aim of this study was to evaluate the results after revision ACL reconstructions and compare them with the results in a control group consisting of primary ACL reconstructions. METHODS: This retrospective study included 56 patients undergoing revision ACL reconstruction and 52 patients receiving primary ACL reconstructions. The follow-up evaluation included clinical examination, instrumented laxity testing, testing of muscle strength, Tegner activity score, Lysholm score, Knee injury and osteoarthritis outcome score (KOOS) and radiological grading of osteoarthritis. RESULTS: The median time from the last ACL reconstruction to follow-up was 90 months in the revision ACL reconstruction group and 96 months in the primary ACL reconstruction group. The revision group had significantly inferior KOOS and Lysholm scores compared with the primary group. Patients in the revision group also showed greater laxity measured with the pivot shift test, a larger reduction in the Tegner activity score, reduced muscle strength in the injured knee, and more severe radiological osteoarthritis; however, no difference in anterior-posterior translation was found. CONCLUSION: Inferior results were found on several of the testing parameters in the revision group compared with the primary group. Patients should receive this information prior to revision ACL reconstructions. LEVEL OF EVIDENCE: III.

Meniscal repair with biofix arrows: results after 4.7 years' follow-up.

BACKGROUND: Absorbable meniscus arrows have, since they were introduced in 1993, become a common all-inside technique in meniscal repair. Potential advantages are conserving the meniscus, simplifying the surgical technique, reducing operating time, and reducing the risk of neurovascular damage. Despite extensive use all over the world, few long-term follow-up studies have been published. HYPOTHESIS: Meniscus arrows have, based on published material, a rate of success around 80% to 90%. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: The Biofix arrow fixation technique was used in 123 patients in need of meniscal repair from January 1997 to December 2002 at our hospital. The patients underwent an interview by phone, mail, or e-mail during autumn 2004 that included questions about reoperation and Lysholm score. In addition, the operative charts were reviewed. RESULTS: There were 118 patients (96%) available for the questionnaire, and 45 of these (38%) had had reoperations done because of meniscal rerupture during the follow-up period. Another 3 patients were waiting for meniscal reoperations. In addition, the charts of 2 of those unavailable for the study showed that they had been reoperated, resulting in a total of 41% verified failures. The Lysholm score for the whole study group at follow-up was 85 (range, 36-100). The mean Lysholm score for those who had a second operation was 81 (range, 36-100), and it was 88 (range, 55-100) for the others (P = .009). The mean time between primary operation and reoperation was 17 months (range, 1-75 months). Mean postoperative follow-up was 4.7 years (range, 1.8-7.7 years). CONCLUSION: Meniscal repair with Biofix arrows has an unacceptably low rate of success.