Magnussen, Robert A.

Background: The association between quadriceps strength and functional outcomes after anterior cruciate ligament reconstruction (ACLR) is a focus of current research, while evaluations of hamstring strength are limited, despite the frequent use of hamstring autografts. Purpose/Hypothesis: The purpose of this study was to determine the relationship between changes in quadriceps and hamstring strength symmetry and self-reported outcomes before ACLR and at 12 and 24 weeks after surgery. We hypothesized that improvements in quadriceps and hamstring strength symmetry would be correlated with improvements in self-reported outcome measures within the first 6 months after ACLR. Study Design: Cohort study; Level of evidence, 2. Methods: Thirty patients who underwent ACLR with a hamstring autograft were enrolled. Quadriceps and hamstring strength and Knee injury and Osteoarthritis Outcome Score (KOOS) values were assessed before and at 12 and 24 weeks after ACLR; limb symmetry indexes for strength were calculated at each time point. The Friedman and Wilcoxon signed-rank tests were used to analyze changes in KOOS values over time. Spearman rank-order correlations were used to test the relationship between changes in strength and KOOS values between each time point. Results: Hamstring and quadriceps limb symmetry significantly increased with time ( P ≤ .03). Fair correlations were observed between changes in the hamstring index and changes in the KOOS Symptoms subscore from before surgery to 12 weeks postoperatively ( r = 0.48; P ≤ .05). Changes in the quadriceps index (QI) were moderately correlated with changes in the KOOS Sport/Recreation subscore ( r = 0.60; P = .001), and fair correlations were seen between the QI and the KOOS Quality of Life subscore ( r = 0.39; P ≤ .04) from preoperatively to 12 weeks after surgery. Moderate correlations were seen between the QI and the KOOS Sport/Recreation subscore ( r = 0.57; P = .005) from 12 to 24 weeks after surgery. Conclusion: Improvements in quadriceps and hamstring strength symmetry were modestly associated with improvements in athletes’ perceived function in the first 6 months after ACLR. Specifically, improvements in hamstring symmetry were associated with improvements in knee symptoms within the first 12 weeks postoperatively, while improvements in quadriceps symmetry were associated with improvements in self-reported sport function throughout the first 6 months after ACLR. The restoration of strength symmetry within the first 6 months may be a critical component of rehabilitation aimed at maximizing function after ACLR. Further investigation is warranted to comprehensively evaluate whether the timing of strength gains predicts future function, including those who successfully return to their preinjury activity level after ACLR.

Objectives: The incidence of second anterior cruciate ligament (ACL) injury after ACL reconstruction (ACLR) and return to sport (RTS) in a young, active population is likely between 25-33% with the greatest risk in the first 12 months after RTS. Although the use of allograft tissue in young athletes has been reported to result in increased risk of graft failure, differences in graft and contralateral ACL injury risk between patients who receive a hamstrings (HS) autograft and bone-patellar tendon- bone (BTB) autograft has yet to be reported in a young, athletic population. The tested hypothesis was that the relative risk (RR) of ipsilateral graft failure would be higher in young, active patients who receive an ACLR with a hamstrings graft, while the RR of contralateral ACL injury would be higher in patients who receive and ACLR with a BTB autograft. Methods: One hundred thirty-nine subjects (99 female/40 male) with a mean age of 16.9±2.0 years old (range: 13-25 y/o) underwent ACLR with either a HS autograft (n=79) or a BTB autograft (n=60) and were released to return to pivoting/cutting sport. These patients were enrolled in a prospective, observational cohort study and were tracked for incidence of 2 nd ACL after ACLR for a median of 73 months. Thirty-four (24.5%) suffered a 2 nd ACL injury. Fisher’s exact tests were used to determine whether graft choice (HS vs. BTB) was associated with risk of either ipsilateral graft failure or contralateral ACL injury. Sub-group analyses by sex were also conducted. Results: Patients who underwent ACLR with HS graft (n=79) sustained 14 ipsilateral tears and 6 contralateral ACL injuries. Patients who received an ACLR with BTB (n=62) sustained 2 ipsilateral tears and 12 contralateral ACL injuries (Table 1). Patients who received an ACLR with HS graft were 6 times more likely (RR=6.2; 95% CI: 1.4-28.7) to suffer a graft failure after RTS than the BTB group. In the first 12 months after RTS, the HS graft patients were nearly 10 times (RR=9.5; 95% CI: 1.2-76.1) more likely to suffer an ipsilateral graft failure. Patients with a HS graft were 3 times less likely (RR=0.33; 95%CI: 0.12-0.935) to suffer a contralateral ACL injury and nearly 7 times less likely (RR=0.15, 95%CI: 0.031-0.709) to suffer a contralateral ACL injury in the first 12 months after RTS compared to the BTB group. When the cohort was divided by sex, females with HS grafts were significantly more likely to sustain a graft failure in the first 12 months after RTS (p=0.008) and by final follow-up (p=0.002) compared to females with BTB graft. Females with HS grafts were 3 times less likely (RR=0.30; 95%CI: 0.095-0.943) to suffer a contralateral ACL injury than females with BTB graft and 6 times less likely (RR=0.17; 95%CI: 0.034-0.846) to suffer contralateral ACL injury in the first year after RTS. Males demonstrated no significant difference in ipsilateral or contralateral injury risk based on graft type. Conclusion: Young, active females who return to pivoting and cutting sports after ACLR with HS autograft are at greater risk to suffer a graft failure and reduced risk to suffer a contralateral ACL injury compared to females who undergo ACLR with BTB graft tissue. No significant differences in 2 nd ACL injury risk based on graft type were observed in the male patients. [Table: see text]

Background: Knee laxity in the setting of suspected anterior cruciate ligament (ACL) injury is frequently assessed through physical examination using the Lachman, pivot-shift, and anterior drawer tests. The degree of laxity noted on these examinations may influence treatment decisions and prognosis. Hypothesis: Increased preoperative knee laxity would be associated with increased risk of subsequent revision ACL reconstruction and worse patient-reported outcomes 2 years postoperatively. Study Design: Cohort study; Level of evidence, 2. Methods: From an ongoing prospective cohort study, 2333 patients who underwent primary isolated ACL reconstruction without collateral or posterior cruciate ligament injury were identified. Patients reported by the operating surgeons as having an International Knee Documentation Committee (IKDC) grade D for Lachman, anterior drawer, or pivot-shift examination were classified as having high-grade laxity. Multiple logistic regression modeling was used to evaluate whether having high-grade preoperative laxity was associated with increased odds of undergoing revision ACL reconstruction within 2 years of the index procedure, controlling for patient age, sex, Marx activity level, level of competition, and graft type. Multiple linear regression modeling was used to evaluate whether having high-grade preoperative laxity was associated with worse IKDC score or Knee injury and Osteoarthritis Outcome Score Knee-Related Quality of Life subscale (KOOS-QOL) scores at a minimum 2 years postoperatively, controlling for baseline score, patient age, ethnicity, sex, body mass index, marital status, smoking status, sport participation, competition level, Marx activity rating score, graft type, and articular cartilage and meniscus status. Results: Pre-reconstruction laxity data were available for 2325 patients (99.7%). Two-year revision data were available for 2259 patients (96.8%), and patient-reported outcomes were available for 1979 patients (84.8%). High-grade preoperative laxity was noted in 743 patients (31.9%). The mean postoperative IKDC score was 81.8 ± 15.9, and the mean KOOS-QOL score was 72.0 ± 22.0. The presence of high-grade pre-reconstruction laxity was associated with significantly increased odds of ACL graft revision (odds ratio [OR] = 1.87 [95% CI, 1.19-2.95]; P = .007). The presence of high-grade pre-reconstruction laxity was not associated with any difference in postoperative IKDC (β = −0.56, P = .44) or KOOS-QOL (β = 0.04, P = .97). Conclusion: The presence of high-grade pre-reconstruction knee laxity as assessed by manual physical examination under anesthesia is associated with significantly increased odds of revision ACL surgery but has no association with patient-reported outcome scores at 2 years after ACL reconstruction.

AbstractPurposePatellofemoral arthroplasty remains controversial, primarily due to the high failure rates reported with early implants. Numerous case series have been published over the years detailing results of various first‐ and second‐generation implants. The purpose of this work is to summarize results published to date and identify common themes regarding implants, surgical techniques, and indications in order to maximize results of future procedures.MethodsA comprehensive review of the MEDLINE database was carried out to identify all clinical studies related to patellofemoral arthroplasty.ResultsFirst‐generation resurfacing implants were associated with relatively high failure rates in the medium term. Second‐generation implants, with femoral cuts based on TKA designs have yielded more promising medium‐term results. Surgical indications are specific and must be carefully followed to minimize poor results. Short‐term complications are generally related to patellar maltracking, while long‐term complications are generally related to progression of osteoarthritis in the tibiofemoral joint. Implant loosening and polyethylene wear are rarely reported. Short‐term results are favourable for new technology including custom implants and computer navigated surgery.ConclusionsOverall, recent improvements in implant design and surgical techniques have resulted in improvements in short‐ and medium‐term results. More work is required to assess the long‐term outcomes of modern implant designs.Level of evidenceIV.