Comparison of Anterior Cruciate Ligament Tears Treated Nonoperatively Versus With Reconstruction: Risk of Subsequent Surgery

Background: Anterior cruciate ligament (ACL) tears can be devastating injuries, leading to joint instability, meniscal tears, and subsequent arthritis. It is unknown whether ACL reconstruction (ACLR) alters the natural history of joint degeneration in the ACL-deficient knee compared with nonoperative treatment, and few studies have examined outcomes in middle–aged patients. Purpose: The objective of this study was to compare the midterm risk of subsequent ipsilateral knee surgery in middle–aged patients after an ACL injury treated with initial conservative (nonoperative) management (CM) versus ACLR (operative management [OM]) within 6 months of the diagnosis. Study Design: Cohort study; Level of evidence, 3. Methods: We performed an electronic database search from 2011 to 2012 for all patients aged 35 to 55 years with an initial diagnosis of magnetic resonance imaging—confirmed ACL tear. Patients who elected CM and those who underwent ACLR within 6 months of the diagnosis (OM) were identified. Index patient and clinical characteristics were collected from the health record. All patients were longitudinally observed until August 31, 2017. The primary outcome was subsequent ipsilateral knee surgeries, and secondary outcomes included contralateral knee surgeries, deep surgical–site infections, and venous thrombotic events. Results: The mean follow–up was 4.8 ± 0.6 years. The CM group included 463 patients (40.2%) and the OM group included 690 patients (59.8%). The mean ages were 43.9 ± 5.7 years and 42.7 ± 5.3 years for patients in the CM and OM groups, respectively ( P < .001). Obesity and smoking were significantly more common in the CM group. During the follow–up, 180 patients (38.9%) in the CM group underwent subsequent ipsilateral knee surgery compared with 73 (10.6%) patients in the OM group ( P < .001). The mean time to the first ipsilateral procedure was 0.9 ± 1.1 years in the CM and 2 ± 1.5 years in the OM group ( P < .001). Delayed ipsilateral ACLRs were performed in 81 patients in the CM group (17.5%); non-ACLR ipsilateral knee surgeries were performed in 156 patients in the CM group (33.7%). Contralateral knee surgery rates were similar. In a regression model, after controlling for age, sex, the Charlson Comorbidity Index score, and smoking status, it was found that normal body mass index and CM group were risk factors for undergoing subsequent knee surgery or ipsilateral non-ACLR surgery. Conclusion: Excluding delayed ACLR, subsequent ipsilateral knee surgeries were more common and occurred earlier in middle–aged patients with nonoperatively managed ACL tears compared with patients managed with reconstruction.

Knee Hyperextension Greater Than 5° Is a Risk Factor for Failure in ACL Reconstruction Using Hamstring Graft

Background: The degree of knee hyperextension in isolation has not been studied in detail as a risk factor that could lead to increased looseness or graft failure after anterior cruciate ligament (ACL) reconstruction. Purpose: To analyze whether more than 5° of passive knee hyperextension is associated with worse functional outcomes and greater risk of graft failure after primary ACL reconstruction with hamstring tendon autograft. Study Design: Cohort study; Level of evidence, 3. Methods: A cohort of patients who had primary ACL reconstruction with hamstring tendon autografts was divided into 2 groups based on passive contralateral knee hyperextension greater than 5° (hyperextension group) and less than 5° (control group) of hyperextension. Groups were matched by age, sex, and associated meniscal tears. The following data were collected and compared between the groups: patient data (age and sex), time from injury to surgery, passive knee hyperextension, KT-1000 arthrometer laxity, pivot shift, associated meniscal injury and treatment (meniscectomy or repair), contralateral knee ligament injury, intra-articular graft size, follow-up time, occurrence of graft failure, and postoperative Lysholm knee scale and International Knee Documentation Committee subjective form scores. Results: Data from 358 patients initially included in the study were analyzed; 22 were excluded because the time from injury to surgery was greater than 24 months, and 22 were lost to follow-up. From the cohort of 314 patients, 102 had more than 5° of knee hyperextension. A control group of the same size (n = 102) was selected by matching among the other 212 patients. Significant differences in the incidence of graft failure (14.7% vs 2.9%; P = .005) and Lysholm knee scale score (86.4 ± 9.8 vs 89.6 ± 6.1; P = .018) were found between the 2 groups. Conclusion: Patients with more than 5° of contralateral knee hyperextension submitted to single-bundle ACL reconstruction with hamstring tendons have a higher failure rate than patients with less than 5° of knee hyperextension.

DESCRIPTIVE EPIDEMIOLOGY STUDY OF THE JUSTIFYING PATELLAR INSTABILITY TREATMENT BY EARLY RESULTS (JUPITER) COHORT

Background: Patellar instability is a common injury in young patients and can lead to significant morbidity and arthritis. Its management is controversial. JUPITER (Justifying Patellar Instability Treatment by Early Results) is a hypothesis-driven, multi-center, multi-armed, prospective cohort study developed to describe clinical characteristics and predictors of clinical outcomes in the young patellar instability population. Purpose: To describe the formation of JUPITER and provide a descriptive, epidemiologic analysis of patient demographics and clinical features of the patients in this prospective cohort. Methods: After training and institutional review board approval, surgeons began enrolling patients between 10-30 years of age who sustained a patellar dislocation. Patient demographics, dislocation history, physical exam characteristics, and PROMs were collected. Results: By January 1, 2019, 28 surgeons from 12 sites had prospectively enrolled 661 patients (677 knees) with patellar instability. 62% were female and mean age was 15.8 years. 447 knees (66%) were in the operative group and 230 (34%) in the non-operative group. 55% of knees reported that they had more than 1 dislocation (operative group 73%; non-operative group 27%, p<0.001). Operative treatment was indicated in 39% of first-time dislocators and 85% of recurrent dislocators (p<0.001). Recurrent and operative group patients had more positive physical exam findings than first-time and non-operative group patients on the affected knee (p<0.05 for J-sign, apprehension, crepitus) and the contralateral knee (p<0.05 J-sign, apprehension). The recurrent group was nearly twice as likely to be ligamentously lax (Beighton score 5 or greater) compared to first-time patients (p<0.001). Baseline PROMs varied with the recurrent group having lower Pedi-FABS (p=0.001) and KOOS-QoL (0.008) scores and higher Kujala (0.009), KOOS ADL (0.008), KOOS Sports (<0.001), and Pedi-IKDC (0.014) scores than the first-time dislocator group. Conclusions: The JUPITER Group has been able to accumulate the largest prospectively collected patellar instability database to date. Over half of patients in this group reported they sustained more than one dislocation. Operative management was indicated in 39% of first-time dislocators, 50% of which had sustained an osteochondral fracture, and 85% of recurrent dislocators. Recurrent dislocators were more likely to have positive physical exam findings on both the affected and contralateral knee.

PREVALENCE AND CLINICAL FEATURES OF BILATERAL OSTEOCHONDRITIS DISSECANS (OCD) OF THE KNEE IN PEDIATRIC AND ADOLESCENT PATIENTS PRESENTING WITH UNILATERAL SYMPTOMS

Background: Osteochondritis dissecans(OCD) is an idiopathic condition primarily involving the subchondral bone with secondary articular cartilage changes, commonly occurring in the knee. The true prevalence of bilateral OCD in patients presenting with unilateral OCD symptoms is unknown. Hypothesis/Purpose: The goals of this study are to determine the prevalence and characteristics of bilateral OCD in patients with unilateral symptoms and compare to those with unilateral disease. Methods: An electronic medical record database was queried from 2003-2016 to identify and retrospectively review patients 18 years or younger presenting to a single pediatric institution with a diagnosis of OCD of the knee and strictly unilateral knee pain. Contralateral knee imaging of the asymptomatic knee within one year of initial presentation was required. Lesion characteristics were evaluated on both x-ray and magnetic resonance imaging(MRI) assessing size, location, and Hefti staging. Treatment(both surgical and non-operative) and outcomes were recorded. Patients with unilateral OCD were compared with those with bilateral disease using appropriate statistical analyses. Results: Eighty consecutive patients, 63 males(79%) and 17 females(21%), average age of 13.1 years old (range:8-18), were included. 71% of symptomatic lesions were located on the medial femoral condyle and 14% on the lateral femoral condyle with 20 lesions(25%) deemed stable on MRI evaluation. A positive correlation was found between increasing lesion size and severity of MRI/Hefti grade(Figure-1). Twelve patients(15%) were found to have bilateral OCD on contralateral imaging, with five of the contralateral lesions(42%) considered stable on MRI. There was no significant difference in skeletal maturity between patients with bilateral vs. unilateral disease. Fifty-two patients(77%) with unilateral disease underwent surgical intervention, while 9(75%) of those with bilateral disease underwent a surgical procedure on either knee. In patients discovered to have an asymptomatic contralateral lesion, 67% ultimately underwent surgical intervention on the contralateral knee. Comparing patients with unilateral and bilateral disease, no statistical differences were found in terms of patient demographics or lesion characteristics. Conclusion: In patients presenting with unilateral OCD symptoms, there was a 15% prevalence of bilateral disease. There was no difference in age, sex, physeal status or lesion characteristics between patients with unilateral vs. bilateral OCD lesions, and we found no difference in rates of surgical intervention. A consistent relationship between lesion size and Hefti classification was appreciated. Given the prevalence of asymptomatic contralateral lesions and required intervention, our study supports the recommendation for bilateral radiologic knee evaluation for pediatric and adolescent patients presenting with unilateral knee OCD. [Figure: see text]

Use of a Spacer Block Tool for Assessment of Joint Line Position during Revision Total Knee Arthroplasty

There is a tendency of orthopaedic surgeons to elevate joint line (JL) in revision total knee arthroplasty (RTKA). Here, we ascertain the use of the spacer block tool (SBT) to determine JL more accurately for less experienced RTKA surgeons. To perform more precise restoration of JL, an SBT with markers was developed and produced using computer software and three-dimensional printers. The study was planned prospectively to include patients who received either condylar constrained or rotating hinge RTKA between January 2016 and December 2019. To determine JL, distance from fibular head (FH), adductor tubercle (AT), and medial epicondyle (ME) were measured on contralateral knee preoperative radiographs and on operated knee postoperative radiographs. Patients were randomized and grouped according to the technique of JL reconstruction. In Group 1, conventional methods by evaluating aforementioned landmarks and preoperative contralateral knee measurements were used to determine JL, whereas in Group 2, the SBT was used. The main outcome measure was the JL change in revised knee postoperatively in contrast to contralateral knee to compare effective restoration of JL between the groups. Twenty-five patients in Group 1 (3 males, 22 females, 72 years, body mass index [BMI] 32.04 ± 4.45) and 20 patients (7 males, 13 females, 74 years, BMI 30.12 ± 5.02) in Group 2 were included in the study. JL measurements for the whole group were FH-JL = 18.3 ± 3.8 mm, AT-JL = 45.8 ± 4.6 mm, and ME-JL = 27.1 ± 2.8 mm preoperatively, and FH-JL = 20.7 ± 4.2 mm, AT-JL = 43.4 ± 5.2 mm, and ME-JL = 24.7 ± 3.1 mm postoperatively. JL level differences in reference to FH, AT, and ME in Group 1 were 3.6 ± 3.1, 3.6 ± 3.5, and 3.4 ± 3.1 mm, respectively, and in Group 2 were 1.0 ± .0.9, 1.3 ± 1.3, and 1.1 ± 1.3 mm, respectively. There were statistically significant differences between the two groups in JL changes referenced to all of the specific landmarks (p < 0.05). The use of the SBT helped restore JL effectively in our cohort of RTKA patients. Therefore, this tool may become a useful and inexpensive gadget for less experienced and low-volume RTKA surgeons.